Single-stage autologous cartilage repair results in positive patient-reported outcomes for chondral lesions of the knee: a systematic review

AIM

This article aims to perform a systematic review of the clinical literature regarding the efficacy of single-stage autologous cartilage repair.

METHODS

A systematic review of the literature was performed using PubMed, Scopus, Web of Science, and the Cochrane Library. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.

RESULTS

Twelve studies were identified; however, due to overlapping patient cohorts, nine studies were included for data extraction and analysis. Six studies applied minced cartilage, while three studies utilized enzymatically processed cartilage. Two authorship groups described single-stage techniques that exclusively utilized cartilage from the debrided lesion rim, while the remaining groups either utilized healthy cartilage or combined healthy cartilage with cartilage debrided from lesion rim. Among the included techniques, scaffold augments were used in four studies, and three studies implemented bone autograft augmentation. When summarizing patient reported outcome measures for the included studies, single-stage autologous cartilage repair demonstrated an average improvement ranging from 18.7 ​± ​5.3 to 30.0 ​± ​8.0 amongst the Knee Injury and Osteoarthritis Outcome Scores subsections, 24.3 ​± ​10.5 for the International Knee Documentation Committee subjective score, and 41.0 ​± ​10.0 for Visual Analogue Scale-Pain.

CONCLUSION

Single-stage autologous cartilage repair is a promising technique with positive clinical data to date. The current study highlights the overall improvement in patient reported outcomes after repair for chondral defects to the knee with average follow-up ranging from 12 to 201 months and also the heterogeneity and variability of the single-stage surgical technique. Further discussion on the standardization of practices for a cost-effective single-stage augmented autologous cartilage technique is needed. In the future, a well-designed randomized controlled trial is needed to explore the efficacy of this therapeutic modality relative to established intervention.

LEVEL OF EVIDENCE

Systematic review; Level IV.

Lateral meniscus posterior root repair in the setting of anterior cruciate ligament reconstruction restores joint mechanics to the intact state and improves clinical function: a systematic review of biomechanical and clinical outcomes

PURPOSE

To perform a systematic review of biomechanical and clinical outcomes following lateral meniscus posterior root (LMPR) repair with concomitant anterior cruciate ligament reconstruction (ACLR).

METHODS

A literature search was performed systematically using PubMed, Embase, and Medline databases in April 2022. The search included the following terms combined with Boolean operators: 'Meniscus repairs', 'Meniscal Repair', 'Posterior Horn', 'Root', 'Radial'. Inclusion criteria consisted of level I-IV human clinical and biomechanical studies reporting biomechanical data and/or outcomes following LMPR repair in the setting of ACLR.

RESULTS

Three biomechanical studies, all utilizing a transtibial pullout technique, were identified, all of which reported significant improvement in joint contact pressures and mechanics and 3/4 of which reported significant improvement in anterior or rotational stability with LMPR repair. Five clinical studies, consisting of 146 patients (mean age 28.5 ± 1.1 years) undergoing LMPR repair, were identified with an average follow-up of 19.1 months (range 6.2-46 months). Across all clinical studies, Lysholm and International Knee Documentation Committee (IKDC) scores were found to improve postoperatively, with 3/4 reporting significant improvement in Lysholm (all, p ≤ 0.001) scores and 3/5 reporting significant improvement in IKDC scores when compared to preoperative values (all, p ≥ 0.004). Meniscal extrusion decreased significantly following repair in 2/4 studies (all, p ≤ 0.001).

CONCLUSIONS

Biomechanically, transtibial pullout repair of the LMPR restored joint contact pressures and joint mechanics to intact levels when performed with concomitant ACLR. Clinically, LMPR repair with concurrent ACLR resulted in improved Lysholm and IKDC scores. These findings enable surgeons to determine optimal treatment plans and discuss realistic outcomes with patients when encountering LMPR injuries.

LEVEL OF EVIDENCE

IV.

Development and internal validation of machine learning algorithms for predicting complications after primary total hip arthroplasty

INTRODUCTION

Complications after total hip arthroplasty (THA) may result in readmission or reoperation and impose a significant cost on the healthcare system. Understanding which patients are at-risk for complications can potentially allow for targeted interventions to decrease complication rates through pursuing preoperative health optimization. The purpose of the current was to develop and internally validate machine learning (ML) algorithms capable of performing patient-specific predictions of all-cause complications within two years of primary THA.

METHODS

This was a retrospective case-control study of clinical registry data from 616 primary THA patients from one large academic and two community hospitals. The primary outcome was all-cause complications at a minimum of 2-years after primary THA. Recursive feature elimination was applied to identify preoperative variables with the greatest predictive value. Five ML algorithms were developed on the training set using tenfold cross-validation and internally validated on the independent testing set of patients. Algorithms were assessed by discrimination, calibration, Brier score, and decision curve analysis to quantify performance.

RESULTS

The observed complication rate was 16.6%. The stochastic gradient boosting model achieved the best performance with an AUC = 0.88, calibration intercept = 0.1, calibration slope = 1.22, and Brier score = 0.09. The most important factors for predicting complications were age, drug allergies, prior hip surgery, smoking, and opioid use. Individual patient-level explanations were provided for the algorithm predictions and incorporated into an open access digital application: https://sorg-apps.shinyapps.io/tha_complication/ CONCLUSIONS: The stochastic boosting gradient algorithm demonstrated good discriminatory capacity for identifying patients at high-risk of experiencing a postoperative complication and proof-of-concept for creating office-based applications from ML that can perform real-time prediction. However, this clinical utility of the current algorithm is unknown and definitions of complications broad. Further investigation on larger data sets and rigorous external validation is necessary prior to the assessment of clinical utility with respect to risk-stratification of patients undergoing primary THA.

LEVEL OF EVIDENCE

III, therapeutic study.

Determining the Time Required to Achieve Clinically Significant Outcomes on the PROMIS Upper Extremity Questionnaire After Arthroscopic Rotator Cuff Repair

Background

Clinically significant outcome (CSO) thresholds for the Patient-Reported Outcome Measurement Information System-Upper Extremity (PROMIS-UE) score have been previously defined after arthroscopic rotator cuff repair (RCR). However, the time required to achieve CSOs for the PROMIS-UE score is unknown.

Purpose

To (1) determine the time required to achieve the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) score thresholds after RCR for the PROMIS-UE questionnaire and (2) identify patient factors associated with earlier or delayed achievement of these clinical benchmarks.

Study Design

Case-control study; Level of evidence, 3.

Methods

A prospectively maintained institutional database was retrospectively reviewed for consecutive patients who underwent RCR between January 2018 and January 2019. Patients were included if they completed the PROMIS-UE questionnaire both preoperatively and at standardized postoperative time intervals: 5 to 7 months (6-month time point), 11 to 13 months (1-year time point), and ≥23 months (2-year time point). Kaplan-Meier survival curves with interval censoring were used to define the cumulative percentage of patients who achieved the MCID, SCB, and PASS. Patient variables associated with earlier or delayed achievement of the MCID, SCB, and PASS were determined using Weibull parametric survival regression analysis.

Results

Included were 105 patients undergoing RCR (age, 57.3 ± 10.3 years; body mass index, 31.5 ± 6.1 kg/m²). By 2-year follow-up, the cumulative percentage of patients achieving the MCID, SCB, and PASS was 86.7%, 76.2%, and 74.3%, respectively. The mean time required to reach the MCID, SCB, and PASS score thresholds was 9.5 ± 3.8, 10.3 ± 4.4, and 9.8 ± 4.6 months, respectively. Factors associated with delayed achievement of CSOs included greater baseline PROMIS-UE score (MCID and SCB) and workers' compensation insurance (PASS). Greater baseline PROMIS-UE scores were associated with earlier achievement of the PASS.

Conclusion

Most patients achieved CSOs for the PROMIS-UE within 12 months of RCR. Patient-specific factors found to be associated with earlier or delayed achievement of CSOs can be used to inform patient discussions on the expected timeline for recovery after RCR.

Lower donor site morbidity with hamstring and quadriceps tendon autograft compared with bone-patellar tendon-bone autograft after anterior cruciate ligament reconstruction: a systematic review and network meta-analysis of randomized controlled trials

PURPOSE

To perform a meta-analysis of RCTs evaluating donor site morbidity after bone-patellar tendon-bone (BTB), hamstring tendon (HT) and quadriceps tendon (QT) autograft harvest for anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, OVID/Medline and Cochrane databases were queried in July 2022. All level one articles reporting the frequency of specific donor-site morbidity were included. Frequentist model network meta-analyses with P-scores were conducted to compare the prevalence of donor-site morbidity, complications, all-cause reoperations and revision ACLR among the three treatment groups.

RESULTS

Twenty-one RCTs comprising the outcomes of 1726 patients were included. The overall pooled rate of donor-site morbidity (defined as anterior knee pain, difficulty/impossibility kneeling, or combination) was 47.3% (range, 3.8-86.7%). A 69% (95% confidence interval [95% CI]: 0.18-0.56) and 88% (95% CI: 0.04-0.33) lower odds of incurring donor-site morbidity was observed with HT and QT autografts, respectively (p < 0.0001, both), when compared to BTB autograft. QT autograft was associated with a non-statistically significant reduction in donor-site morbidity compared with HT autograft (OR: 0.37, 95% CI: 0.14-1.03, n.s.). Treatment rankings (ordered from best-to-worst autograft choice with respect to donor-site morbidity) were as follows: (1) QT (P-score = 0.99), (2) HT (P-score = 0.51) and (3) BTB (P-score = 0.00). No statistically significant associations were observed between autograft and complications (n.s.), reoperations (n.s.) or revision ACLR (n.s.).

CONCLUSION

ACLR using HT and QT autograft tissue was associated with a significant reduction in donor-site morbidity compared to BTB autograft. Autograft selection was not associated with complications, all-cause reoperations, or revision ACLR. Based on the current data, there is sufficient evidence to recommend that autograft selection should be personalized through considering differential rates of donor-site morbidity in the context of patient expectations and activity level without concern for a clinically important change in the rate of adverse events.

LEVEL OF EVIDENCE

Level I.

A Guide for the Application of Statistics in Biomedical Studies Concerning Machine Learning and Artificial Intelligence

With the plethora of machine learning (ML) analyses published in the orthopaedic literature within the last 5 years, several attempts have been made to enhance our understanding of what exactly ML means and how it is used. At its most fundamental level, ML comprises a branch of artificial intelligence that uses algorithms to analyze and learn from patterns in data without explicit programming or human intervention. On the other hand, traditional statistics require a user to specifically choose variables of interest to create a model capable of predicting an outcome, the output of which (1) may be falsely influenced by the variables chosen to be included by the user and (2) does not allow for optimization of performance. Early publications have served as succinct editorials or reviews intended to ease audiences unfamiliar with ML into the complexities that accompany the subject. Most commonly, the focus of these studies concerns the terminology and concepts surrounding ML because it is important to understand the rationale behind performing such studies. Unfortunately, these publications only touch on the most basic aspects of ML and are too frequently repetitive. Indeed, the conclusion of these articles reiterate that the potential clinical utility of these algorithms remains tangential at best in their current form and caution against premature adoption without external validation. By doing so, our perspective and ability to draw our own conclusions from these studies have not advanced, and we are left concluding with each subsequent study that a new algorithm is published for an outcome of interest that cannot be used until further validation. What readers now need is to regress to embrace the principles of the scientific method that they have used to critically assess vast numbers of publications before this wave of newly applied statistical methodology-a guide to interpret results such that their own conclusions can be drawn. LEVEL OF EVIDENCE: Level V, expert opinion.

The Altmetric Attention Score Is Associated With Citation Rates and May Reflect Academic Impact in the Total Joint Arthroplasty Literature

Background: Given the increasing interest and potential use of social media for the promotion of orthopedic literature, there is a need to better understand Altmetrics. Purposes: We sought to determine the relationship between the Altmetric Attention Score (AAS) and the number of citations for articles on total joint arthroplasty (TJA) published in orthopedics journals. We also sought to determine the predictors of greater social media attention for these articles. Methods: Articles on TJA published in Bone and Joint Journal (BJJ), Journal of Bone and Joint Surgery (JBJS), Clinical Orthopedics and Related Research (CORR), Journal of Arthroplasty, Journal of Knee Surgery, Hip International, and Acta Orthopaedica in 2016 were extracted (n = 498). One-way analysis of variance with Bonferroni corrections was used to compare AAS and citations across journals. Multivariate regressions were used to determine predictors of social media attention and number of citations. Results: The mean AAS and number of citations were 7.5 (range: 0-289) and 16.7 (range: 0-156), respectively. Significant between-group effects were observed according to journal for AAS and number of citations. Publishing an article in JBJS was the strongest predictor of higher number of citations. Publishing an article in BJJ was the only independent predictor of higher AAS, while publishing an article in JBJS or CORR trended toward statistical significance. A higher AAS was a significant predictor of a higher number of citations. Number of citations and number of study references were positive predictors of greater social media attention on Twitter and Facebook. Conclusions: In articles on TJA published in 7 journals in 2016, a higher AAS was a associated with a higher number of citations. Various bibliometric characteristics were found to be significantly associated with greater social media attention; the most common influences were number of citations and number of references. Researchers in orthopedics can use this information when considering how to assess the impact of their work.

External Validation of a Machine Learning Algorithm for Predicting Clinically Meaningful Functional Improvement After Arthroscopic Hip Preservation Surgery

BACKGROUND

Individualized risk prediction has become possible with machine learning (ML), which may have important implications in enhancing clinical decision making. We previously developed an ML algorithm to predict propensity for clinically meaningful outcome improvement after hip arthroscopy for femoroacetabular impingement syndrome. External validity of prognostic models is critical to determine generalizability, although it is rarely performed.

PURPOSE

To assess the external validity of an ML algorithm for predicting clinically meaningful improvement after hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

An independent hip preservation registry at a tertiary academic medical center was queried for consecutive patients/athletes who underwent hip arthroscopy for femoroacetabular impingement syndrome between 2015 and 2017. By assuming a minimal clinically important difference (MCID) outcome/event proportion of 75% based on the original study, a minimum sample of 132 patients was required. In total, 154 patients were included. Age, body mass index, alpha angle on anteroposterior pelvic radiographs, Tönnis grade and angle, and preoperative Hip Outcome Score-Sports Subscale were used as model inputs to predict the MCID for the Hip Outcome Score-Sports Subscale 2 years postoperatively. Performance was assessed using identical metrics to the internal validation study and included discrimination, calibration, Brier score, and decision curve analysis.

RESULTS

The concordance statistic in the validation cohort was 0.80 (95% CI, 0.71 to 0.87), suggesting good to excellent discrimination. The calibration slope was 1.16 (95% CI, 0.74 to 1.61) and the calibration intercept 0.13 (95% CI, -0.26 to 0.53). The Brier score was 0.15 (95% CI, 0.12 to 0.18). The null model Brier score was 0.20. Decision curve analysis revealed favorable net treatment benefit for patients with use of the algorithm as compared with interventional changes made for all and no patients.

CONCLUSION

The performance of this algorithm in an independent patient population in the northeast region of the United States demonstrated superior discrimination and comparable calibration to that of the derivation cohort. The external validation of this algorithm suggests that it is a reliable method to predict propensity for clinically meaningful improvement after hip arthroscopy and is an essential step forward toward introducing initial use in clinical practice. Potential uses include integration into electronic medical records for automated prediction, enhanced shared decision making, and more informed allocation of resources to optimize patient outcomes.

Relative Efficacy of Intra-articular Injections in the Treatment of Knee Osteoarthritis: A Systematic Review and Network Meta-analysis

BACKGROUND

In younger patients and those without severe degenerative changes, the efficacy of intra-articular (IA) injections as a nonoperative modality for treating symptomatic knee osteoarthritis (OA)-related pain while maintaining function has become a subject of increasing interest.

PURPOSE

To assess and compare the efficacy of different IA injections used for the treatment of knee OA, including hyaluronic acid (HA), corticosteroids (CS), platelet-rich plasma (PRP), and plasma rich in growth factors (PRGF), with a minimum 6-month patient follow-up.

STUDY DESIGN

Meta-analysis of randomized controlled trials; Level of evidence, 1.

METHODS

A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the following databases: PubMed/MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar. Mean or mean change from baseline and standard deviation for outcome scores regarding pain and function were recorded at the 6-month follow-up and converted to either a 0 to 100 visual analog scale score for pain or a 0 to 100 Western Ontario and McMaster Universities Osteoarthritis Index score for function. A frequentist network meta-analysis model was developed to compare the effects of HA, CS, PRP, PRGF, and placebo on patient-reported outcomes.

RESULTS

All IA treatments except CS were found to result in a statistically significant improvement in outcomes when compared with placebo. PRP demonstrated a clinically meaningful difference in function-related improvement when compared with CS and placebo due to large effect sizes. Studies evaluating outcomes of PRGF reported significant improvement when compared with placebo due to large effect sizes, whereas a potential clinically significant difference was detected in the same comparison parameters in pain evaluation. With regard to improvements in pain, function, and both combined, PRP was found to possess the highest probability of efficacy, followed by PRGF, HA, CS, and placebo.

CONCLUSION

PRP yielded improved outcomes when compared with PRGF, HA, CS, and placebo for the treatment of symptomatic knee OA at a minimum 6-month follow-up. Further investigations evaluating different IA and other nonoperative treatment options for patients with knee OA are warranted to better understand the true clinical efficacy and long-term outcomes of nonsurgical OA management.

Machine learning algorithms predict within one size of the final implant ultimately used in total knee arthroplasty with good-to-excellent accuracy

PURPOSE

To develop a novel machine learning algorithm capable of predicting TKA implant sizes using a large, multicenter database.

METHODS

A consecutive series of primary TKA patients from two independent large academic and three community medical centers between 2012 and 2020 was identified. The primary outcomes were final tibial and femoral implant sizes obtained from an automated inventory system. Five machine learning algorithms were trained using six routinely collected preoperative features (age, sex, height, weight, and body mass index). Algorithms were validated on an independent set of patients and evaluated through accuracy, mean absolute error (MAE), and root mean-squared error (RMSE).

RESULTS

A total of 11,777 patients were included. The support vector machine (SVM) algorithm had the best performance for femoral component size(MAE = 0.73, RMSE = 1.06) with accuracies of 42.2%, 88.3%, and 97.6% for predicting exact size, ± one size, and ± two sizes, respectively. The elastic-net penalized linear regression (ENPLR) algorithm had the best performance for tibial component size (MAE 0.70, RMSE = 1.03) with accuracies of 43.8%, 90.0%, and 97.7% for predicting exact size, ± one size, and ± two sizes, respectively.

CONCLUSION

Machine learning algorithms demonstrated good-to-excellent accuracy for predicting within one size of the final tibial and femoral components used for TKA. Patient height and sex were the most important factors for predicting femoral and tibial component size, respectively. External validation of these algorithms is imperative prior to use in clinical settings.

LEVEL OF EVIDENCE

Case-control, III.

Time to Achieving Clinically Significant Outcomes After Meniscal Allograft Transplantation

PURPOSE

To determine the time to achieving minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for commonly administered patient-reported outcome (PRO) measures and risk factors affecting achievement of clinically significant outcomes in patients undergoing meniscal allograft transplantation (MAT).

METHODS

A prospectively maintained MAT registry was retrospectively reviewed from April 2014 to May 2019. Patients who underwent revision MAT or did not complete preoperative PROs or one post operative time point were excluded. Patients who underwent concomitant procedures were included in the analysis. PROs were administered preoperatively and at 6 months, 1 year, and 2 years postoperatively. Previously defined MCID and PASS thresholds were utilized and Kaplan-Meier survival curve analysis with interval censoring was used to calculate the cumulative percentages of MCID and PASS achievement at each follow-up time interval (5-7, 11-13, and 23-25 months).

RESULTS

Eighty patients (age: 28.35 ± 9.76, 50% male) who completed preoperative, 6-month (n = 69, 86% compliance), and 1-year (n = 76, 95% compliance) PROs were included. The majority of patients (>50%) achieved MCID and PASS on most included PROs. Workers' compensation status was found to significantly delay achievement of MCID and PASS on all PROs except for PASS on Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life (QoL). Higher body mass index (BMI) significantly delayed time to achieving MCID on KOOS Pain and activities of daily living (ADL), as well as PASS on KOOS Symptoms and KOOS QoL.

CONCLUSION

This study suggests that the majority of patients have clinically significant improvements in pain and function after MAT, with more than 50% of patients experiencing clinically significant improvement within the first postoperative year. Workers' compensation status and high BMI may prolong time to achievement of MCID and PASS after MAT.

Establishing Clinically Significant Outcomes After Anterior Cruciate Ligament Reconstruction in Pediatric Patients

PURPOSE

The purpose of this study was to establish clinically significant outcome values for the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) after anterior cruciate ligament reconstruction (ACLR) in the pediatric and adolescent populations and to assess factors that were associated with achieving these outcomes.

METHODS

Patients between the age of 10 to 21 who underwent ACLR between 2016 and 2018 were identified and patient-reported outcomes (PROs) were collected preoperatively and postoperatively. Intraoperative variables collected included graft choice, graft size (diameter), graft fixation method, and concomitant procedures. PROs collected for analysis were the International Knee Documentation Committee Score (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS). MCID and PASS were calculated using receiver operating characteristic with area under the curve analyses for delta (ie, baseline-to-postoperative change) and absolute postoperative PRO scores, respectively.

RESULTS

A total of 59 patients were included in the analysis. Of the entire study population, 53 (89.8%) reported satisfaction with their surgical outcome. The established MCID threshold values based on the study population were 33.3 for IKDC, 28.6 for (KOOS) Symptoms, 19.4 for Pain, 2.9 for activities of daily living (ADL), 45.0 for Sport, and 25.0 for Quality of Life (QoL). Postoperative scores greater than the following values corresponded to the PASS: 80.5 for IKDC, 75.0 (KOOS) Symptoms, 88.9 for Pain, 98.5 for ADL, 75.0 for Sport, and 68.8 for QoL.

CONCLUSION

Clinically meaningful outcomes including MCID and PASS were established for pediatric ACLR surgery using selected PRO measures, IKDC, and KOOS. Patient age, sex, graft type, and graft size were not associated with greater achievement of these outcomes. In contrast, collision sports, fixed-object high-impact rotational landing sports, and concomitant meniscectomy surgery were associated with a decreased likelihood of achieving clinically significant improvement. However, findings must be interpreted with caution due to limitations in follow-up and sample size.

LEVEL OF EVIDENCE

Level IV: case series.

Clinical and Magnetic Resonance Imaging Outcomes After Microfracture Treatment With and Without Augmentation for Focal Chondral Lesions in the Knee: A Systematic Review and Meta-analysis

BACKGROUND

Focal cartilage lesions represent a common source of knee pain and disability, with the potential for the development and progression of osteoarthritis. Currently, microfracture (MFx) represents the most utilized first-line surgical treatment for small, focal chondral lesions. Recent investigations have examined methods of overcoming the limitations of MFx utilizing various augmentation techniques.

PURPOSE

To perform a systematic review and meta-analysis evaluating clinical and radiographic outcomes in patients undergoing isolated MFx versus MFx augmented with orthobiologics or scaffolds for focal chondral defects of the knee.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic review was performed to identify studies evaluating outcomes and adverse events in patients undergoing isolated MFx versus augmented MFx for focal chondral defects in the knee from 1945 to June 1, 2021. Data were extracted from each article that met the inclusion/exclusion criteria. Meta-analyses were performed for all outcomes reported in a minimum of 3 studies.

RESULTS

A total of 14 studies were identified, utilizing 7 different types of injectable augmentation regimens and 5 different scaffolding regimens. Across the 14 studies, a total of 744 patients were included. The mean patient age was 46.8 years (range, 34-58 years), and 58.3% (n = 434/744) of patients were women. The mean final follow-up time was 26.7 months (range, 12-60 months). The mean chondral defect size ranged from 1.3 to 4.8 cm². A post hoc analysis comparing mean improvement in postoperative outcomes scores compared with preoperative values found no significant differences in the improvement in the visual analog scale (VAS), International Knee Documentation Committee (IKDC), or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores between patients undergoing isolated MFx and those undergoing MFx + augmentation. Patients undergoing MFx + augmentation reported significantly greater improvements in the Lysholm score and postoperative MOCART (magnetic resonance observation of cartilage repair tissue) scores compared with the isolated MFx group.

CONCLUSION

Patients undergoing combined MFx + augmentation reported significant improvements in mean Lysholm and MOCART scores, without significant improvements in VAS, IKDC, or WOMAC scores when compared with patients undergoing isolated MFx.

Current State of Research Gap-Years in Orthopedic Surgery Residency Applicants: Program Directors' Perspectives

BACKGROUND

The purpose of this study was to determine how orthopedic residency program directors (PDs) evaluate residency applicants who participated in a research gap-year (RGY).

METHODS

A 23 question electronically administered survey was created and emailed to all Accreditation Council for Graduate Medical Education (ACGME) orthopedic residency PDs for the 2020-21 application cycle. PDs were emailed directly if active contact information was identifiable. If not, program coordinators were emailed. The survey contained questions regarding the background information of programs and aimed at identifying how PDs view and evaluate residency applicants who participated in a RGY. Descriptive statistics for each question were performed.

RESULTS

Eighty-four (41.8%) of 201 PDs responded. Most respondent programs (N=62, 73.8%) identified as an academic center. The most common geographic region was the Midwest, N=33 (39.3%). Few programs (N=3, 3.8%) utilize a publication "cut-off" when screening residency applicants. When asked how many peer-reviewed publications were necessary to deem a RGY as "productive," responses ranged from 0-15 publications (median interquartile range 4.5 [3-5]). Forty-one (53.3%) PDs stated they would council medical students to take a RGY with USMLE Step 1 scores being the #1 factor guiding that advice. More PDs disagree than agree (N=35, 43.6%; vs N=22, 28.2%) that applicants who complete a RGY are more competitive applicants, and 35 PDs (45.5%) agree research experiences will become more important in resident selection as USMLE Step 1 transitions to Pass/Fail.

CONCLUSION

Program directors have varying views on residency applicants who did a RGY. While few programs use a publication cutoff, the median number of publications deemed as being a "productive" RGY was approximately 5. Many PDs agree that research experiences will become more important as USMLE Step becomes Pass/Fail. This information can be useful for students interested in pursuing a RGY and for residency programs when evaluating residency applicants. Level of Evidence: IV.

A Novel Fluoroscopic View for Improved Assessment of the Safety of the Posterosuperior Screw in Femoral Neck Fracture Fixation

BACKGROUND

The purpose of the present study was to determine specific fluoroscopic views of the femoral neck to accurately identify partially extraosseous ("in-out-in"; IOI) placement of the posterosuperior screw for fixation of femoral neck fractures.

METHODS

A 3.2-mm guide pin was placed in the posterosuperior aspect of 2 synthetic femur models: 1 entirely intraosseous and 1 IOI. Sequential fluoroscopic images were made at 5° intervals in order to identify which fluoroscopic projections identified IOI guide pin placement. These images were utilized to inform screw placement and assessment in the second phase of the study, which involved the use of cadaveric specimens. In Phase II, the posterosuperior screw of the inverted triangle was placed in 10 cadaveric specimens with use of a standard posteroanterior fluoroscopic view and 1 of 2 lateral views, either (1) neck in line with the shaft, i.e., 0° lateral; or (2) a -15° rollunder view. The final fluoroscopic views (i.e., the posteroanterior and multiple lateral and oblique views) were randomized and blinded for review by 10 orthopaedic residents and 5 attending orthopaedic traumatologists. Specimens were stripped of soft tissue and inspected for screw perforation.

RESULTS

Overall accuracy of respondents was 68.8%, with no difference between the attending traumatologists (71.8%) and resident surgeons (67.4%; p = 0.173). Interobserver reliability was moderate (κ = 0.496). Dissection identified that 4 (40%) of 10 screws were extraosseous. All of the extraosseous screws were placed with use of the 0° lateral view. The -15° rollunder lateral view was the most sensitive (81.7%) and specific (92.2%) view for identifying IOI screw placement.

CONCLUSIONS

Surgeons often utilize the standard posteroanterior and 0° lateral fluoroscopic views to safely place screws; however, many of these screws are IOI. The addition of a -15° rollunder lateral view significantly improved identification of IOI screws in the posterosuperior femoral neck. Unidentified IOI screw placement may result in damage to the blood supply of the femoral head.

Efficacy and Applications of Artificial Intelligence and Machine Learning Analyses in Total Joint Arthroplasty: A Call for Improved Reporting

BACKGROUND

There has been a considerable increase in total joint arthroplasty (TJA) research using machine learning (ML). Therefore, the purposes of this study were to synthesize the applications and efficacies of ML reported in the TJA literature, and to assess the methodological quality of these studies.

METHODS

PubMed, OVID/MEDLINE, and Cochrane libraries were queried in January 2021 for articles regarding the use of ML in TJA. Study demographics, topic, primary and secondary outcomes, ML model development and testing, and model presentation and validation were recorded. The TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guidelines were used to assess the methodological quality.

RESULTS

Fifty-five studies were identified: 31 investigated clinical outcomes and resource utilization; 11, activity and motion surveillance; 10, imaging detection; and 3, natural language processing. For studies reporting the area under the receiver operating characteristic curve (AUC), the median AUC (and range) was 0.80 (0.60 to 0.97) among 26 clinical outcome studies, 0.99 (0.83 to 1.00) among 6 imaging-based studies, and 0.88 (0.76 to 0.98) among 3 activity and motion surveillance studies. Twelve studies compared ML to logistic regression, with 9 (75%) reporting that ML was superior. The average number of TRIPOD guidelines met was 11.5 (range: 5 to 18), with 38 (69%) meeting greater than half of the criteria. Presentation and explanation of the full model for individual predictions and assessments of model calibration were poorly reported (<30%).

CONCLUSIONS

The performance of ML models was good to excellent when applied to a wide variety of clinically relevant outcomes in TJA. However, reporting of certain key methodological and model presentation criteria was inadequate. Despite the recent surge in TJA literature utilizing ML, the lack of consistent adherence to reporting guidelines needs to be addressed to bridge the gap between model development and clinical implementation.

Comparison of Surgical Time, Short-term Adverse Events, and Implant Placement Accuracy Between Manual, Robotic-assisted, and Computer-navigated Total Hip Arthroplasty: A Network Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Recent years have observed the increasing utilization of robotic-assisted and computer navigation techniques in total hip arthroplasty (THA), given the proposed benefits of enhanced consistency and precision in implant placement. The purpose of this study was to conduct a systematic review of randomized controlled trials (RCTs) to determine whether differences in surgical times, adverse events, and implant positioning existed between manual, robotic-assisted, and computer navigation THA.

METHODS

PubMed, OVID/MEDLINE, and Cochrane databases were queried for RCTs comparing robotic-assisted versus manual THA and computer navigation versus manual THA at a minimum 1-year follow-up. Frequentist model network meta-analyses with P-scores were conducted to compare revisions, complications, and surgical times among the three treatment groups. A random-effects meta-analysis between computer navigation and manual THAs was conducted to analyze cup positioning because no robotic-assisted THA studies reported this outcome.

RESULTS

Five RCTs compared robotic-assisted and manual THAs, while seven compared computer navigation and manual THAs. manual THA was associated with significantly reduced surgical time in comparison with computer navigation (mean difference: 23.3 minutes) and robotic-assisted THAs (mean difference: 8.6 minutes; P < 0.001). No difference was observed in the incidence of all-cause complications (computer navigation: 1.7%, manual: 6.6%, and robotic-assisted: 16.2%) or revisions (computer navigation: 1.0%, manual: 1.7%, and robotic-assisted 4.8%) among the three treatment groups based on the network meta-analysis. In three studies that reported acetabular implant positioning, computer navigation had a significantly higher percentage of acetabular cups placed in the Lewinnek "safe zone" compared with manual THA (79% versus 52%; P = 0.02).

CONCLUSIONS

manual THA results in markedly shorter surgical times and a similar incidence of complications and revisions compared with robotic-assisted and computer navigation THAs, given the sample sizes available for study. However, computer navigation THA led to increased precision in the placement of acetabular implants.

Patient Compliance and Satisfaction with Topical Benzoyl Peroxide Gel Prior to Shoulder Surgery

Background

Methods

Results

Conclusion

Association Between Preoperative Patient Factors and Clinically Meaningful Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Machine Learning Analysis

BACKGROUND

The International Hip Outcome Tool 12-Item Questionnaire (IHOT-12) has been proposed as a more appropriate outcome assessment for hip arthroscopy populations. The extent to which preoperative patient factors predict achieving clinically meaningful outcomes among patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) remains poorly understood.

PURPOSE

To determine the predictive relationship of preoperative imaging, patient-reported outcome measures, and patient demographics with achievement of the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) for the IHOT-12 at a minimum of 2 years postoperatively.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were analyzed for consecutive patients who underwent hip arthroscopy for FAIS between 2012 and 2018 and completed the IHOT-12 preoperatively and at a minimum of 2 years postoperatively. Fifteen novel machine learning algorithms were developed using 47 potential demographic, clinical, and radiographic predictors. Model performance was evaluated with discrimination, calibration, decision-curve analysis and the brier score.

RESULTS

A total of 859 patients were identified, with 685 (79.7%) achieving the MCID, 535 (62.3%) achieving the PASS, and 498 (58.0%) achieving the SCB. For predicting the MCID, discrimination for the best-performing models ranged from fair to excellent (area under the curve [AUC], 0.69-0.89), although calibration was excellent (calibration intercept and slopes: -0.06 to 0.02 and 0.24 to 0.85, respectively). For predicting the PASS, discrimination for the best-performing models ranged from fair to excellent (AUC, 0.63-0.81), with excellent calibration (calibration intercept and slopes: 0.03-0.18 and 0.52-0.90, respectively). For predicting the SCB, discrimination for the best-performing models ranged from fair to good (AUC, 0.61-0.77), with excellent calibration (calibration intercept and slopes: -0.08 to 0.00 and 0.56 to 1.02, respectively). Thematic predictors for failing to achieve the MCID, PASS, and SCB were presence of back pain, anxiety/depression, chronic symptom duration, preoperative hip injections, and increasing body mass index (BMI). Specifically, thresholds associated with lower likelihood to achieve a clinically meaningful outcome were preoperative Hip Outcome Score-Activities of Daily Living <55, preoperative Hip Outcome Score-Sports Subscale >55.6, preoperative IHOT-12 score ≥48.5, preoperative modified Harris Hip Score ≤51.7, age >41 years, BMI ≥27, and preoperative α angle >76.6°.

CONCLUSION

We developed novel machine learning algorithms that leveraged preoperative demographic, clinical, and imaging-based features to reliably predict clinically meaningful improvement after hip arthroscopy for FAIS. Despite consistent improvements after hip arthroscopy, meaningful improvements are negatively influenced by greater BMI, back pain, chronic symptom duration, preoperative mental health, and use of hip corticosteroid injections.

High Rate of Return to Work by 3 Months Following Latarjet for Anterior Shoulder Instability

PURPOSE

To evaluate the rate and duration of return to work in patients undergoing Latarjet for failed soft-tissue stabilization or glenoid bone loss.

METHODS

Consecutive patients undergoing Latarjet from 2005 to 2015 at our institution were retrospectively reviewed at a minimum of 2 years postoperatively. Patients completed a standardized and validated work questionnaire, Western Ontario Shoulder Instability Index Survey, and a satisfaction survey.

RESULTS

Of 89 eligible patients who had Latarjet, 67 patients (75.3%) responded to the questionnaire, of whom 51 patients (76.1%) were employed within 3 years before surgery (mean age: 29.9 ± 11.8 years; mean follow-up: 54.6 ± 11.9 months) and had an average glenoid bone loss of 14.5 ± 6.1%. Fifty patients (98.0%) returned to work by 2.7 ± 3.0 months postoperatively; 45 patients (88.2%) patients returned to the same level of occupational intensity. Those who held sedentary, light, moderate, or heavy intensity occupations returned to their previous occupation at a rate of 100.0%, 93.3%, 90.0%, and 66.7% (P = .2) at a duration of 1.2 ± 1.6 months, 1.8 ± 1.9 months, 3.1 ± 3.5 months, and 6.5 ± 4.1 months (P = .001), respectively. The average postoperative Western Ontario Shoulder Instability Index score was 70.9 ± 34.2. Fifty patients (98.0%) noted at least "a little improvement" in their quality of life following surgery, with 35 patients (68.6%) noting great improvement. Furthermore, 49 patients (96.1%) reported being satisfied with their procedure, with 25 patients (49.0%) reporting being very satisfied. Four patients (7.8%) returned to the operating room, with 1 patient (2.0%) requiring arthroscopic shoulder stabilization.

CONCLUSIONS

Approximately 98% of patients who underwent Latarjet returned to work by 2.7 ± 3.0 months postoperatively. Patients with greater-intensity occupations had a longer duration of absence before returning to their preoperative level of occupational intensity. Information regarding return to work is imperative in preoperative patient consultation to manage expectations.

LEVEL OF EVIDENCE

IV, case series.

The Efficacy of Platelet-Rich Plasma for Ligament Injuries: A Systematic Review of Basic Science Literature With Protocol Quality Assessment

Background:

Despite the existence of many clinical studies on platelet-rich plasma (PRP) interventions for ligamentous pathology, basic science consensus regarding the indications, mechanisms, and optimal composition of PRP for treating ligament injuries is lacking.

Purpose:

To (1) compare the efficacy of PRP in animal models of ligament injury with placebo and (2) describe the potential variability in PRP preparation using accepted classification systems.

Study Design:

Systematic review.

Methods:

The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Embase, and Ovid MEDLINE were queried in April 2020 for in vivo and in vitro basic science studies regarding PRP use for ligament injury. Study design, results, PRP composition, and analyzed cellular and molecular markers were extracted, and outcomes relative to control models were documented. Bias was assessed using the SYRCLE risk-of-bias tool.

Results:

Included were 43 articles (31 in vivo and 12 in vitro studies) investigating the anterior cruciate ligament/cranial cruciate ligament (n = 32), medial collateral ligament (n = 6), suspensory ligament (n = 3), patellar ligament (n = 1), and Hock ligament (n = 1). Platelet concentration was reported in 34 studies (77.3%); leukocyte composition, in 12 (27.3%); and red blood cell counts, in 7 (15.9%). With PRP treatment, 5 of 12 in vitro studies demonstrated significant increases in cell viability, 6 of 12 in gene expression, 14 of 32 in vivo studies reported superior ligament repair via histological evaluation, and 13 in vivo studies reported superior mechanical properties. Variability in PRP preparation methods was observed across all articles, and only 1 study reported all necessary information to be classified by the 4 schemes we used to evaluate reporting. Among the in vivo studies, detection and performance bias were consistently high, whereas selection, attrition, reporting, and other biases were consistently low.

Conclusion:

Conflicting data on the cellular and molecular effects of PRP for ligament injuries were observed secondary to the finding that included studies were heterogeneous, limiting interpretation across studies and the ability to draw meaningful conclusions. Clinical trials and any causal relationship between PRP use in ligament injuries and its potential for regeneration and healing should be pursued with caution if based solely on basic science data.

Establishing the Minimal Clinically Important Difference and Patient-Acceptable Symptomatic State After Arthroscopic Meniscal Repair and Associated Variables for Achievement

PURPOSE

To establish the minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) after arthroscopic meniscal repair and identify the factors associated with achieving these outcomes.

METHODS

This is a retrospective study with prospectively collected data. Patient-reported outcome measures (PROMs) were collected from April 2017 to March 2020. All patients who underwent arthroscopic meniscal repair and completed both preoperative and postoperative PROMs were included in the analysis. MCID and PASS were calculated via half the standard deviation of the delta PRO change from baseline (for International Knee Documentation Committee Score [IKDC]) and via anchor-based methodology (Knee Injury and Osteoarthritis Outcome Score [KOOS] subscales).

RESULTS

Sixty patients were included in the final analysis. The established MCID threshold values were 10.9 for IKDC, 12.3 for KOOS Symptoms, 11.8 for KOOS Pain, 11.4 for KOOS Activities of Daily Living (ADL), 16.7 for KOOS Sport, and 16.9 for KOOS Quality of Life (QoL). Postoperative scores greater than the following values corresponded to the PASS: 69.0 for IKDC, 75.0 for KOOS Symptoms, 80.6 for KOOS Pain, 92.7 for KOOS ADL, 80.0 for KOOS Sport, and 56.3 for KOOS QoL. Higher preoperative PRO scores were associated with lower likelihood of achieving MCID. Concomitant ligament procedures were associated with a higher likelihood of achieving PASS. Tears to both menisci were associated with decreased likelihood of achieving MCID and PASS for IKDC. Horizontal tears were associated with decreased likelihood of achieving PASS for IKDC and KOOS. Complex tears were associated with decreased likelihood of achieving MCID for KOOS.

CONCLUSION

Clinically meaningful outcomes such as MCID and PASS were established for meniscal repair surgery using selected PROMs for IKDC and KOOS subscales. Variables more likely to be associated with achieving these outcomes include lower preoperative PRO score and concomitant ligament procedure, whereas higher preoperative PRO score, tearing of both medial and lateral menisci, and horizontal and complex tear classifications were associated with decreased likelihood of achieving these outcomes.

LEVEL OF EVIDENCE

IV, retrospective case series.

Return to sport following Latarjet glenoid reconstruction for anterior shoulder instability

BACKGROUND

Latarjet coracoid transfer reconstruction is the gold standard for the treatment of recurrent shoulder instability with anterior-inferior glenoid bone loss, and return to sport is often a primary outcome of interest in this patient population. The purpose of this study was to determine the rate of return to sport in patients undergoing the Latarjet procedure and variables that are associated with a higher likelihood of a successful return to sport.

METHODS

A prospectively maintained institutional registry was retrospectively queried between August 2012 and August 2016 for all patients who underwent the Latarjet procedure. Patients were contacted electronically and via telephone to administer a previously validated and standardized return-to-sport survey. Patients self-reported return to sport, varying sports participation, recurrence of instability, and time to return to sport. Multivariate analysis was performed to determine variables associated with each outcome.

RESULTS

Of 83 patients, 66 (75.3%) were available for final follow-up, of whom 60 participated in sports prior to surgery and were eligible for inclusion. The average follow-up period was 53.8 ± 11.8 months. The average age at surgery was 26.7 ± 11.3 years, and the average body mass index was 26.2 ± 4.0 kg/m². There were 54 patients (90%) who were able to return to sport at an average of 8.6 ± 4.1 months following surgery. In total, 36 patients (60%) were able to return to sport at the same level or a better level of intensity, 19 of 28 patients (67.9%) were able to return to throwing sports without difficulty, and 31 of 60 patients (51.7%) reported that their shoulder was a hindrance to some activity. An increased likelihood of returning to sport was associated with increased body mass index (P = .016), male sex (P = .028), and decreased humeral bone loss volume (P = .034). An increased likelihood of returning to sport at the same level or a better level of intensity was associated with reduced humeral bone loss volume (P = .026). Recurrent instability was associated with humeral bone loss (P = .038).

CONCLUSION

Although a large majority of patients were able to return to sport following the Latarjet procedure, some patients experienced limitation with throwing and return to sport at the preinjury level. Greater humeral bone loss was associated with inferior outcomes. These findings should be discussed with patients in the preoperative setting to manage expectations appropriately.

Patients undergoing anatomic total shoulder arthroplasty achieve clinically significant outcomes faster than those undergoing reverse shoulder arthroplasty

BACKGROUND

Clinically significant outcome (CSO) benchmarks have been previously established for outcome assessment after total shoulder arthroplasty. However, the time required to achieve CSO improvement is not well understood. The purpose of this study was to (1) determine the time-dependent achievement of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) in patients undergoing either anatomic total shoulder (TSA) or reverse total shoulder arthroplasty (RTSA) and compare the results of the 2 populations and (2) identify variables associated with earlier or delayed achievement of each CSO.

METHODS

A prospectively maintained institutional registry was retrospectively queried for all patients receiving a primary TSA or RTSA between September 2, 2016-October 31, 2017. The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) was administered to all patients preoperatively and at standardized postoperative time periods: 5-7 months (6-month time point), 11-13 months (1-year time point), and 23-25 months (2-year time point). Cumulative percentages of CSO achievement were calculated using Kaplan-Meier survival curve analysis with interval censoring. A Weibull parametric survival regression analysis was used to investigate the influence of demographic and clinical variables on delayed or earlier CSO achievement.

RESULTS

A total of 153 patients (157 shoulders) undergoing TSA (n = 76) and RTSA (n = 81) were included in the study population. The RTSA cohort was older (70.2 ± 7.5 vs. 61.0 ± 8.4, P < .001), had a lower BMI (28.8 ± 5.9 vs. 31.5 ± 6.5, P = .006), and a greater proportion of females (53.1% vs. 32.9%, P = .017) relative to TSA. For SCB, there was a significant difference in the cumulative percentage of TSA and RTSA patients reaching this threshold at both the 6-month (77.3% vs. 59.0%, P = .024) and 2-year (92.0% vs. 79.5%, P = .048) time periods, with similar findings demonstrated for PASS. There was a significant difference in the average time required to achieve the PASS (TSA: 6.1 months vs. rTSA: 11.6 months, P = .009), but not the MCID (P = .407) or SCB (P = .153). Factors significantly associated with earlier achievement of more than 1 of the CSO benchmarks were regular preoperative physical exercise and diagnosis of rotator cuff tear without osteoarthritis.

CONCLUSION

Patients undergoing RTSA had lower rates of achieving SCB and PASS at both 6 months and 2 years compared to patients undergoing TSA. Patients undergoing RTSA on average required nearly double the time to achieve PASS compared with those undergoing TSA. In both groups, clinically significant improvement continued for the entire 2-year duration of study follow-up.

Risk Factors for Ramp Lesions of the Medial Meniscus: A Systematic Review and Meta-analysis

BACKGROUND

Failure to appropriately identify and repair medial meniscal ramp lesions at the time of anterior cruciate ligament (ACL) reconstruction (ACLR) may result in increased anterior tibial translation and internal rotation, increasing the risk for graft failure. Knowledge of the risk factors leading to the development of ramp lesions may enhance clinicians' vigilance in specific ACL-deficient populations and subsequently repair of these lesions at the time of ACLR.

PURPOSE

To perform a systematic review and meta-analysis of factors tested for associations with ramp lesions and to determine which were significantly associated with the presence of ramp lesions.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed, OVID/Medline, and Cochrane databases were queried in April 2020. Data pertaining to study characteristics and reported risk factors for ramp lesions were recorded. DerSimonian-Laird binary random-effects models were constructed to quantitatively evaluate the association between risk factors and ramp lesions by generating effect estimates in the form of odds ratios (ORs) with 95% CIs. Qualitative analysis was performed to describe risk factors that were variably reported.

RESULTS

The review included 12 studies with 8410 patients. The overall pooled prevalence of ramp lesions was 21.9% (range, 9.0%-41.7%). A total of 45 risk factors were identified, of which 8 were explored quantitatively. There was strong evidence to support that posteromedial tibial edema on magnetic resonance imaging (MRI) (OR, 2.12; 95% CI, 1.27-3.56; P = .004), age <30 years (OR, 2.02; 95% CI, 1.23-3.22; P = .002), and complete ACL tears (OR, 3.0; 95% CI, 1.41-6.20; P = .004) were risk factors for ramp lesions. There was moderate evidence to support that male sex (OR, 1.58; 95% CI, 1.36-1.83; P < .001) and concomitant lateral meniscal tears (OR, 1.54; 95% CI, 1.11-2.13; P = .009) were risk factors for ramp lesions. Chronic ACL injury (≥24 months) demonstrated minimal evidence as a risk factor (OR, 1.41; 95% CI, 1.14-1.74; P = .001). No significant associations were determined between contact injury or revision ACLR and the presence of ramp lesions.

CONCLUSION

Significant associations between male sex, age <30 years, posteromedial tibial edema on MRI, concomitant lateral meniscal tears, complete ACL tears, injury chronicity, and the presence of ramp lesions were found. Contact injury and revision ACLR were not significantly associated with the presence of ramp lesions.

Application of Machine Learning Algorithms to Predict Clinically Meaningful Improvement After Arthroscopic Anterior Cruciate Ligament Reconstruction

Background:

Understanding specific risk profiles for each patient and their propensity to experience clinically meaningful improvement after anterior cruciate ligament reconstruction (ACLR) is important for preoperative patient counseling and management of expectations.

Purpose:

To develop machine learning algorithms to predict achievement of the minimal clinically important difference (MCID) on the International Knee Documentation Committee (IKDC) score at a minimum 2-year follow-up after ACLR.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

An ACLR registry of patients from 27 fellowship-trained sports medicine surgeons at a large academic institution was retrospectively analyzed. Thirty-six variables were tested for predictive value. The study population was randomly partitioned into training and independent testing sets using a 70:30 split. Six machine learning algorithms (stochastic gradient boosting, random forest, neural network, support vector machine, adaptive gradient boosting, and elastic-net penalized logistic regression [ENPLR]) were trained using 10-fold cross-validation 3 times and internally validated on the independent set of patients. Algorithm performance was assessed using discrimination, calibration, Brier score, and decision-curve analysis.

Results:

A total of 442 patients, of whom 39 (8.8%) did not achieve the MCID, were included. The 5 most predictive features of achieving the MCID were body mass index ≤27.4, grade 0 medial collateral ligament examination (compared with other grades), intratunnel femoral tunnel fixation (compared with suspensory), no history of previous contralateral knee surgery, and achieving full knee extension preoperatively. The ENPLR algorithm had the best relative performance (C-statistic, 0.82; calibration intercept, 0.10; calibration slope, 1.15; Brier score, 0.068), demonstrating excellent predictive ability in the study’s data set.

Conclusion:

Machine learning, specifically the ENPLR algorithm, demonstrated good performance for predicting a patient’s propensity to achieve the MCID for the IKDC score after ACLR based on preoperative and intraoperative factors. The femoral tunnel fixation method was the only significant intraoperative variable. Range of motion and medial collateral ligament integrity were found to be important physical examination parameters. Increased body mass index and prior contralateral surgery were also significantly predictive of outcome.

The Minimally Clinically Important Difference and Substantial Clinical Benefit in Anterior Cruciate Ligament Reconstruction: A Time-to-Achievement Analysis

This study examined the time-dependent course of the minimally clinically important difference (MCID) and the substantial clinical benefit (SCB) achievement for International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales following anterior cruciate ligament reconstruction (ACLR). A prospective institutional registry was queried for patients receiving ACLR. The patient-reported outcome measures (PROMs) of interest included the IKDC score and KOOS sub-scales. One hundred forty-three patients (mean±SD age, 30.86±12.78 years; mean±SD body mass index, 25.51±4.64 kg/m²) were included in the analysis. Threshold values for the MCID/SCB were 18.9 of 29.6 on IKDC score, 15.7 of 25.3 on KOOS Symptom, 11.9 of 15.5 on KOOS Pain, 13.3 of 20.0 on KOOS ADL, 25.9 of 35.8 on KOOS Quality of Life (QoL), and 27.0 of 43.0 on KOOS Sport (area under the curve, 0.74-0.91). Overall, MCID achievement rates increased from 28.0% to 42.7% at 6 months to 41.9% to 70.8% at 12 months. Achievement rates of SCB increased from 16.1% to 30.4% at 6 months to 29.3% to 51.8% at 12 months. Statistically significant increases in MCID achievement (chi-square=47.95-79.36, all P<.001) and SCB achievement (chi-square=26.02-53.24, all P<.001) occurred from preoperative to 6-month time points across PROMs. From 6-month to 12-month time points, increases in MCID achievement occurred on IKDC score and KOOS QoL (chi-square=5.53-15.11, P<.001-.009). Statistically significant increases in MCID and SCB achievement occurred from preoperative to 6-month time points across IKDC score and KOOS subscales; however, statistically significant increases in achievement rates from 6 months to 1 year occurred on IKDC score, KOOS QoL, and KOOS Sport. This study underlines the importance of considering psychological factors and rehabilitative milestones when examining the achievement MCID and SCB after ACLR. [Orthopedics. 2021;44(5):299-305.].

Contribution of Multimodal Analgesia to Postoperative Pain Outcomes Immediately After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Level 1 Randomized Clinical Trials

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is associated with moderate to severe pain in the immediate postoperative period. The optimal individual preemptive or intraoperative anesthetic modality on postoperative pain control is not well-known.

PURPOSE

To systematically review and perform a meta-analysis comparing postoperative pain scores (visual analog scale [VAS]), opioid consumption, and incidence of complications during the first 24 hours after primary ACLR in patients receiving spinal anesthetic, adjunct regional nerve blocks, or local analgesics.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, Embase, MEDLINE, Biosis Previews, SPORTDiscus, Ovid, PEDRO, and the Cochrane Library databases were systematically searched from inception to March 2020 for human studies, using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist. Inclusion criteria consisted of (1) level 1 studies reporting on the use of spinal anesthesia, adjunct regional anesthesia (femoral nerve block [FNB] or adductor canal block [ACB]), or local analgesia in patients undergoing primary ACLR and (2) studies reporting on patient-reported VAS, opioid consumption, and incidence of complications related to anesthesia within the first 24 hours after surgery. Non-level 1 studies, studies utilizing a combination of anesthetic modalities, and those not reporting outcomes during the first 24 hours were excluded. Data were synthesized, and a random effects meta-analysis was performed to determine postoperative pain, opioid use, and complications based on anesthetic modality at multiple time points (0-4, 4-8, 8-12, 12-24 hours).

RESULTS

A total of 263 studies were screened, of which 27 level 1 studies (n = 16 regional blocks; n = 12 local; n = 4 spinal) met the inclusion criteria and were included in the meta-analysis. VAS scores were significantly lower in patients receiving a regional block as compared with spinal anesthesia 8 to 12 hours after surgery (P < .01), patients receiving an FNB versus ACB at 12 to 24 hours (P < .01), and those treated with a continuous FNB rather than single-shot regional blocks (FNB, ACB) at 12 to 24 hours (P < .01). No significant difference in VAS was appreciated when spinal, regional, and local anesthesia groups were compared.

CONCLUSION

Based on evidence from level 1 studies, pain control after primary ACLR based on VAS was significantly improved at 8 to 12 hours in patients receiving regional anesthesia as compared with spinal anesthesia. Pain scores were significantly lower at 12 to 24 hours in patients receiving FNB versus ACB and those treated with continuous FNB rather than single-shot regional anesthetic.

Complication rates and outcomes after outpatient shoulder arthroplasty: a systematic review

Background

As the number of total shoulder arthroplasties (TSAs) performed annually increases, some surgeons have begun to shift toward performing TSAs in the outpatient setting. However, it is imperative to establish the safety of outpatient TSA. The purpose of this systematic review was to define complication, readmission, and reoperation rates and patient-reported outcomes after outpatient TSA.

Methods

A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using three databases (PubMed, Ovid, and Embase). English-language publications describing results on complication rates in patients who underwent TSA in an outpatient or ambulatory setting were included. All nonclinical and deidentified database studies were excluded. Bias assessment was conducted with the methodologic index for nonrandomized studies criteria.

Results

Seven studies describing outcomes in outpatient TSA were identified for inclusion. The included studies used varying criteria for selecting patients for an outpatient procedure. The total outpatient 90-day complication rate (commonly including hematomas, wound issues, and nerve palsies) ranged from 7.1%-11.5%. Readmission rates ranged from 0%-3.7%, and emergency and urgent care visits ranged from 2.4%-16.1%. Patient-reported outcomes improved significantly after outpatient TSA in all studies. Two studies found a higher complication rate in the comparative inpatient cohort (P = .023-.027). Methodologic index for nonrandomized studies scores ranged from 9 to 11 (of 16) for noncomparative studies (n = 3), while all comparative studies received a score of a 16 (of 24).

Conclusion

Outpatient TSA in properly selected patients results in a similar complication rate to inpatient TSA. Further studies are needed to aid in determining proper risk stratification to direct patients to inpatient or outpatient shoulder arthroplasty.

Machine Learning Algorithms Predict Functional Improvement After Hip Arthroscopy for Femoroacetabular Impingement Syndrome in Athletes

BACKGROUND

Despite previous reports of improvements for athletes following hip arthroscopy for femoroacetabular impingement syndrome (FAIS), many do not achieve clinically relevant outcomes. The purpose of this study was to develop machine learning algorithms capable of providing patient-specific predictions of which athletes will derive clinically relevant improvement in sports-specific function after undergoing hip arthroscopy for FAIS.

METHODS

A registry was queried for patients who had participated in a formal sports program or athletic activities before undergoing primary hip arthroscopy between January 2012 and February 2018. The primary outcome was achieving the minimal clinically important difference (MCID) in the Hip Outcome Score-Sports Subscale (HOS-SS) at a minimum of 2 years postoperatively. Recursive feature selection was used to identify the combination of variables, from an initial pool of 26 features, that optimized model performance. Six machine learning algorithms (stochastic gradient boosting, random forest, adaptive gradient boosting, neural network, support vector machine, and elastic-net penalized logistic regression [ENPLR]) were trained using 10-fold cross-validation 3 times and applied to an independent testing set of patients. Models were evaluated using discrimination, decision-curve analysis, calibration, and the Brier score.

RESULTS

A total of 1,118 athletes were included, and 76.9% of them achieved the MCID for the HOS-SS. A combination of 6 variables optimized algorithm performance, and specific cutoffs were found to decrease the likelihood of achieving the MCID: preoperative HOS-SS score of ≥58.3, Tönnis grade of 1, alpha angle of ≥67.1°, body mass index (BMI) of >26.6 kg/m2, Tönnis angle of >9.7°, and age of >40 years. The ENPLR model demonstrated the best performance (c-statistic: 0.77, calibration intercept: 0.07, calibration slope: 1.22, and Brier score: 0.14). This model was transformed into an online application as an educational tool to demonstrate machine learning capabilities.

CONCLUSIONS

The ENPLR machine learning algorithm demonstrated the best performance for predicting clinically relevant sports-specific improvement in athletes who underwent hip arthroscopy for FAIS. In our population, older athletes with more degenerative changes, high preoperative HOS-SS scores, abnormal acetabular inclination, and an alpha angle of ≥67.1° achieved the MCID less frequently. Following external validation, the online application of this model may allow enhanced shared decision-making.

Development of supervised machine learning algorithms for prediction of satisfaction at 2 years following total shoulder arthroplasty

BACKGROUND

Patient satisfaction after primary anatomic and reverse total shoulder arthroplasty (TSA) represents an important metric for gauging patients' perception of their care and surgical outcomes. Although TSA confers improvement in pain and function for most patients, inevitably some will remain unsatisfied postoperatively. The purpose of this study was to (1) train supervised machine learning (SML) algorithms to predict satisfaction after TSA and (2) develop a clinical tool for individualized assessment of patient-specific risk factors.

METHODS

We performed a retrospective review of primary anatomic and reverse TSA patients between January 2014 and February 2018. A total of 16 demographic, clinical, and patient-reported outcomes were evaluated for predictive value. Five SML algorithms underwent 3 iterations of 10-fold cross-validation on a training set (80% of cohort). Assessment by discrimination, calibration, Brier score, and decision-curve analysis was performed on an independent testing set (remaining 20% of cohort). Global and local model behaviors were evaluated with global variable importance plots and local interpretable model-agnostic explanations, respectively.

RESULTS

The study cohort consisted of 413 patients, of whom 331 (82.6%) were satisfied at 2 years postoperatively. The support vector machine model demonstrated the best relative performance on the independent testing set not used for model training (concordance statistic, 0.80; calibration intercept, 0.20; calibration slope, 2.32; Brier score, 0.11). The most important factors for predicting satisfaction were baseline Single Assessment Numeric Evaluation score, exercise and activity, workers' compensation status, diagnosis, symptom duration prior to surgery, body mass index, age, smoking status, anatomic vs. reverse TSA, and diabetes. The support vector machine algorithm was incorporated into an open-access digital application for patient-level explanations of risk and predictions, available at https://orthopedics.shinyapps.io/SatisfactionTSA/.

CONCLUSION

The best-performing SML model demonstrated excellent discrimination and adequate calibration for predicting satisfaction following TSA and was used to create an open-access, clinical decision-making tool. However, rigorous external validation in different geographic locations and patient populations is essential prior to assessment of clinical utility. Given that this tool is based on partially modifiable risk factors, it may enhance shared decision making and allow for periods of targeted preoperative health-optimization efforts.

Development and Internal Validation of Supervised Machine Learning Algorithms for Predicting Clinically Significant Functional Improvement in a Mixed Population of Primary Hip Arthroscopy

PURPOSE

To (1) develop and validate a machine learning algorithm to predict clinically significant functional improvements after hip arthroscopy for femoroacetabular impingement syndrome and to (2) develop a digital application capable of providing patients with individual risk profiles to determine their propensity to gain clinically significant improvements in function.

METHODS

A retrospective review of consecutive hip arthroscopy patients who underwent cam/pincer correction, labral preservation, and capsular closure between January 2012 and 2017 from 1 large academic and 3 community hospitals operated on by a single high-volume hip arthroscopist was performed. The primary outcome was the minimal clinically important difference (MCID) for the Hip Outcome Score (HOS)-Activities of Daily Living (ADL) at 2 years postoperatively, which was calculated using a distribution-based method. A total of 21 demographic, radiographic, and patient-reported outcome measures were considered as potential covariates. An 80:20 random split was used to create training and testing sets from the patient cohort. Five supervised machine learning algorithms were developed using 3 iterations of 10-fold cross-validation on the training set and assessed by discrimination, calibration, Brier score, and decision curve analysis on an independent testing set of patients.

RESULTS

A total of 818 patients with a median (interquartile range) age of 32.0 (22.0-42.0) and 69.2% female were included, of whom 74.3% achieved the MCID for the HOS-ADL. The best-performing algorithm was the stochastic gradient boosting model (c-statistic = 0.84, calibration intercept = 0.20, calibration slope = 0.83, and Brier score = 0.13). Of the initial 21 candidate variables, the 8 most important features for predicting the MCID for the HOS-ADL included in model training were body mass index, age, preoperative HOS-ADL score, preoperative pain level, sex, Tönnis grade, symptom duration, and drug allergies. The algorithm was subsequently transformed into a digital application using local explanations to provide customized risk assessment: https://orthoapps.shinyapps.io/HPRG_ADL/.

CONCLUSIONS

The stochastic boosting gradient model conferred excellent predictive ability for propensity to gain clinically significant improvements in function after hip arthroscopy. An open-access digital application was created, which may augment shared decision-making and allow for preoperative risk stratification. External validation of this model is warranted to confirm the performance of these algorithms, as the generalizability is currently unknown.

LEVEL OF EVIDENCE

IV, Case series.

Establishing clinically significant outcome thresholds for the Single Assessment Numeric Evaluation 2 years following total shoulder arthroplasty

BACKGROUND

Single Assessment Numerical Evaluation (SANE) is a simple, time-efficient patient-reported outcome measure (PROM) used to assess postoperative shoulder function. Clinically significant outcome values and ability to correlate with longer legacy PROM scores at 2 years following shoulder arthroplasty are unknown.

METHODS

A retrospective analysis was performed using SANE, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Constant scores that were collected at a minimum 2-year follow-up. A total of 153 patients who underwent anatomic total shoulder arthroplasty (TSA) or reverse total shoulder arthroplasty (RTSA) were included. A distribution-based method was used to determine the minimal clinically important difference (MCID). An anchor-based method was used to determine substantial clinical benefit (SCB). The following anchor question was collected alongside the PROMs and graded on a 15-point Likert-type scale to establish the SCB: "Since your surgery, has there been any change in the pain in your shoulder?" Linear regression was used to assess correlations between PROMs.

RESULTS

SANE showed moderate correlation with ASES (R² = 0.493) and Constant (R² = 0.586) scores (P < .001). The MCID value was 14.9, and the SCB absolute value was 80.4 (area under the curve = 0.663) for SANE. Multivariate logistic regression demonstrated that patients undergoing RTSA were less likely to achieve SCB on all 3 outcome measures (P < .02).

CONCLUSIONS

This study establishes concurrent construct validity for SANE and suggests that it is a valid metric to assess the MCID and SCB at 2 years following anatomic TSA and RTSA. SANE demonstrated moderate correlations with ASES and Constant scores. Patients undergoing RTSA demonstrated a lower propensity to achieve SCB at 2 years postoperatively compared with anatomic TSA.

Orthopaedic Randomized Controlled Trials Published in General Medical Journals Are Associated With Higher Altmetric Attention Scores and Social Media Attention Than Nonorthopaedic Randomized Controlled Trials

PURPOSE

To (1) compare the Altmetric Attention Score (AAS) and citation rates between orthopaedic and nonorthopaedic randomized controlled trials (RCTs) from 5 high-impact medical journals and (2) identify general characteristics of these articles associated with greater exposure on social media platforms.

METHODS

Articles published in The New England Journal of Medicine (NEJM), Lancet, The Journal of the American Medical Association (JAMA), Annals of Internal Medicine, and Archives of Internal Medicine between January 2011 and December 2016 were analyzed. These journals were selected based on retaining high impact factors with rigorous publication standards and availability of the AAS for their publications. The queried time frame was chosen to balance the inception of the AAS with an optimal period for citation accrual. A total of 14 article characteristics, in addition to number of Tweets, Facebook shares, news mentions, and the AAS, were extracted. Inclusion criteria were orthopaedic RCTs reporting on outcomes after surgical intervention. Linear regression was used to assess the relationship between publication characteristics and the AAS and social media attention.

RESULTS

A total of 9 orthopaedic and 59 nonorthopaedic RCTs were included. The mean AASs were significantly different (574 ± 565.7 versus 256.9 ± 222.3, P = .003), whereas citation rate was not (192.2 ± 117.1 versus 382.3 ± 560.3, P = .317). Orthopaedic RCTs had a significantly greater number of mentions on Twitter and Facebook (P < .001). A higher AAS significantly associated with a greater number of citations (β = 0.75, P = .019) for orthopaedic RCTs. The mean AAS of orthopaedic RCTs favoring nonoperative management (809.6 ± 676.3) was greater than those favoring operative treatment (292.0 ± 248.9) but was not statistically significant (P = .361).

CONCLUSION

Orthopaedic RCTs published in 5 high-impact general medical journals had a significantly greater mean AAS relative to nonorthopaedic RCTs, with no differences in citation rates. Additionally, there was a strong association between the AAS and citation rate of orthopaedic RCTs. Orthopaedic RCTs had greater social media exposure on both Twitter and Facebook.

CLINICAL RELEVANCE

Orthopaedic surgeons, researchers, and providers who publish RCTs in high-impact medical journals can anticipate extensive social media attention for their articles relative to other nonorthopaedic RCTs in the same journals. Social media attention may be related to operative versus nonoperative management topics. This study provides further evidence for the increasing use of the AAS and its association with citation accrual.

Machine Learning Predicts Femoral and Tibial Implant Size Mismatch for Total Knee Arthroplasty

Background

Despite reasonable accuracy with preoperative templating, the search for an optimal planning tool remains an unsolved dilemma. The purpose of the present study was to apply machine learning (ML) using preoperative demographic variables to predict mismatch between templating and final component size in primary total knee arthroplasty (TKA) cases.

Methods

This was a retrospective case-control study of primary TKA patients between September 2012 and April 2018. The primary outcome was mismatch between the templated and final implanted component sizes extracted from the operative database. The secondary outcome was mismatch categorized as undersized and oversized. Five supervised ML algorithms were trained using 6 demographic features. Prediction accuracies were obtained as a metric of performance for binary mismatch (yes/no) and multilevel (undersized/correct/oversized) classifications.

Results

A total of 1801 patients were included. For binary classification, the best-performing algorithm for predicting femoral and tibial mismatch was the stochastic gradient boosting model (area under the curve: 0.76/0.72, calibration intercepts: 0.05/0.05, calibration slopes: 0.55/0.7, and Brier scores: 0.20/0.21). For multiclass classification, the best-performing algorithms had accuracies of 83.9% and 82.9% for predicting the concordance/mismatch of the femoral and tibial implant, respectively. Model predictions of greater than 51.0% and 47.9% represented high-risk thresholds for femoral and tibial sizing mismatch, respectively.

Conclusions

ML algorithms predicted templating mismatch with good accuracy. External validation is necessary to confirm the performance and reliability of these algorithms. Predicting sizing mismatch is the first step in using ML to aid in the prediction of final TKA component sizes. Further studies to optimize parameters and predictions for the algorithms are ongoing.

The Patient Acceptable Symptomatic State in Primary Anterior Cruciate Ligament Reconstruction: Predictors of Achievement

PURPOSE

To identify thresholds for patient acceptable symptomatic state (PASS) achievement in a cohort of primary anterior cruciate ligament reconstruction (ACLR) recipients, and to identify factors predictive of PASS achievement.

METHODS

A prospective clinical registry was queried for primary ACLR patients from January 2014 to April 2017 with serial patient-reported outcome measure (PROM) completion at 6, 12, and 24 months. Exclusion criteria included significant concomitant procedures. Knee-based PROMs included the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscores. PASS threshold values were calculated using receiver operating characteristic (ROC) curves with area under the curve (AUC) analysis. A stepwise multivariate regression identified preoperative and operative predictors of PASS achievement.

RESULTS

A total of 144 primary ACLR patients (30.86 ± 12.78 years, body mass index 25.51 ± 4.64, 41.0% male) were included in the analysis. PASS threshold values were established using ROC curve analysis, all of which exceeded 0.7 on AUC analysis (0.742 to 0.911). Factors impacting odds of PASS achievement in the ACLR cohort included preoperative exercises (odds ratio [OR] 2.95 to 4.74, P = .003 to .038), worker's compensation status (OR 0.25 to 0.28, P = .014 to .033), preoperative scores (OR 1.03 to 1.07, P = .005 to <.001), iliotibial band tenodesis (OR 11.08, P = .010), and anteromedial approach (OR 18.03 to 37.05, P < .001).

CONCLUSION

Factors predictive of PASS achievement in recipients of primary ACLR include functional status (e.g., preoperative exercise, preoperative KOOS Sport/Recreation score), worker's compensation status, technique (e.g., anteromedial) and preoperative PROMs. The results of our study are important in better informing shared decision-making models and improving evidence-based guidelines to optimize patient outcomes.

Regenerative Potential of Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis and Chondral Defects: A Systematic Review and Meta-analysis

PURPOSE

To perform a systematic review and meta-analysis evaluating the effects of mesenchymal stem cells (MSCs) on cartilage regeneration and patient-reported pain and function.

METHODS

A systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using a PRISMA checklist. The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) were queried in July 2019 for literature reporting use of stem cells to treat knee osteoarthritis or chondral defects. Data describing administered treatment, subject population, injection type, duration of follow-up, pain and functional outcomes, and radiographic and magnetic resonance imaging findings were extracted. Risk of bias was assessed using the Downs and Black scale. Meta-analyses adjusted for random effects were performed, calculating pooled effect sizes in terms of patient-reported pain and function, cartilage quality, and cartilage volume.

RESULTS

Twenty-five studies with 439 subjects were identified. There was no significant difference in pain improvement between MSC treatment and controls (pooled standardized mean difference [SMD] = 0.23, P = .30). However, MSC treatment was significantly favored for functional improvement (SMD = 0.66, P < .001). There was improvement in cartilage volume after MSC treatment (SMD = 0.84, P < .001). Regarding cartilage quality, meta-analysis resulted in a small, nonsignificant effect size of 0.37 (95%, -0.03 to 0.77, P = .07). There was risk for potential bias among included studies, with 17 (68%) receiving either a grade of "poor" or "fair."

CONCLUSIONS

The pooled SMD from meta-analyses showed statistically significant effects of MSC on self-reported physical function but not self-reported pain. MSCs provided functional benefit only in patients who underwent concomitant surgery. However, this must be interpreted with caution, as there was substantial variability in MSC composition and mode of delivery. MSC treatment provided significant improvement in cartilage volume but not cartilage quality. Preliminary data regarding therapeutic properties of MSC treatment suggest significant heterogeneity in the current literature, and risk of bias is not negligible.

LEVEL OF EVIDENCE

II, Systematic Review and Meta-analysis.

Systematic Review of Sleep Quality Before and After Arthroscopic Rotator Cuff Repair: Are Improvements Experienced and Maintained?

Background:

Poor sleep quality is prevalent among patients with rotator cuff tears (RCTs) and negatively influences the potential for healing and quality of life. However, there is a paucity of literature describing the magnitude and timing of changes in sleep quality after arthroscopic rotator cuff repair (RCR).

Purpose:

(1) To evaluate the prevalence of poor sleep quality in patients undergoing arthroscopic RCR and (2) to determine the timing and magnitude of changes in sleep quality after RCR.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

PubMed, OVID/Medline, and Cochrane databases were queried in January 2020 for literature investigating the prevalence of poor sleep quality in patients with RCTs or changes in sleep quality after arthroscopic RCR. Data pertaining to study characteristics, risk of bias, sleep quality assessments, and clinical outcomes were extracted. A qualitative analysis of the prevalence of poor sleep quality and changes in sleep quality was performed.

Results:

A total of 8 studies (1034 patients) were included. The mean Pittsburgh Sleep Quality Index (PSQI) ranged from 5.2 to 15.0 preoperatively among all studies, while the frequency of patients experiencing poor sleep quality ranged from 40.8% to 89.0% in 4 studies. Four studies reported the mean PSQI at a minimum of 6 months postoperatively, which ranged from 4.2 to 7.1. Four studies did not report the PSQI score or the proportion of patients who experienced poor postoperative sleep quality. One study evaluated the PSQI at 12 months postoperatively, which decreased to 4.2 from 5.8 at 6 months. One study evaluated the PSQI at 24 months postoperatively, which decreased to 5.5 from 6.2 at 6 months.

Conclusion:

Patients with RCTs have a high prevalence of poor sleep quality. Consistent improvements in sleep quality are observed in the 6 months after arthroscopic RCR, but there is limited evidence based on the available data to characterize changes in sleep quality beyond this time. More evidence is needed to characterize changes in sleep quality beyond 6 months and how these changes are perceived by this patient population.

Adjunct Analgesia Reduces Pain and Opioid Consumption After Hip Arthroscopy: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Patients who undergo hip arthroscopy inevitably experience pain postoperatively; however, the efficacy and safety of adjunct analgesia to prevent or reduce pain are not well-understood.

PURPOSE

To perform a comprehensive qualitative synthesis of available randomized controlled trials evaluating the effect of adjunct analgesia on postoperative (1) pain, (2) opioid use, and (3) length of stay (LOS) in patients undergoing hip arthroscopy.

STUDY DESIGN

Systematic review.

METHODS

PubMed, OVID/MEDLINE, and Cochrane Controlled Register of Trials were queried for studies pertaining to analgesia interventions for patients undergoing hip arthroscopy. Two authors independently assessed article bias and eligibility. Data pertaining to changes in pain scores, additional analgesia requirements, length of hospital stay, and complications were extracted and qualitatively reported. Network meta-analyses were constructed to depict mean pain, opioid use, and LOS among the 3 analgesia categories (blocks, local infiltration analgesia, and celecoxib).

RESULTS

Fourteen level 1 studies were included; 12 (85.7%) reported pain reductions in the immediate and perioperative period after hip arthroscopy. Of the 7 studies that assessed an intervention (2 celecoxib, 1 fascia iliaca block, 1 lumbar plexus block, 1 femoral nerve block, 1 intra-articular bupivacaine, 1 extracapsular bupivacaine) versus placebo, more than half reported that patients who received an intervention consumed significantly fewer opioids postoperatively than patients who received placebo (lowest P value = .0006). Of the same 7 studies, 2 reported significantly shortened LOS with interventions, while 4 reported no statistically significant difference in LOS and 1 did not report LOS as an outcome.

CONCLUSION

The majority of studies concerning adjunct analgesia for patients undergoing hip arthroscopy suggest benefits in pain reduction early in the postoperative period. There is mild evidence that adjunct analgesia reduces postoperative opioid use and currently inconclusive evidence that it reduces length of hospital stay. Furthermore, it appears that local infiltration analgesia may provide the greatest benefits in reductions in pain and opioid consumption. We recommend the use of adjunct analgesia in appropriately selected patients undergoing hip arthroscopy without contraindication who are at a high risk of severe postoperative pain.

Is There a Role for Ultrasound in Hip Arthroscopy? A Systematic Review

Purpose

The purpose of this study is to identify and summarize the current utility of intraoperative ultrasound (US) during hip arthroscopy.

Methods

A systematic database query of the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, EMBASE, PubMed (1980 to 2019), and Ovid MEDLINE (1980 to 2019) was performed. After article identification, descriptions of the surgical procedure, use of intraoperative US, procedural complications, and conclusions from each article were recorded and summarized.

Results

Five studies met inclusion criteria, all of which were surgical techniques or technical notes. Four of the 5 studies described US used for placement of arthroscopic portals, and 1 described the use of an intraarticular US catheter for the assessment of an osteochondritis dissecans (OCD) lesion. Of the 4 studies using US for portal placement, 3 were performed supine and 1 was performed in the lateral decubitus position. All studies recognized the need for additional US training or the required assistance of a radiologist to incorporate US into a surgical practice.

Conclusion

Descriptions of intraoperative US during hip arthroscopy are limited in the literature. However, existing technique reports demonstrate the feasibility of US for both portal placement with superficial probes and limited evaluation of cartilage using intraarticular US catheters.

Level of Evidence

V, systematic review.

Development of Machine Learning Algorithms to Predict Patient Dissatisfaction After Primary Total Knee Arthroplasty

BACKGROUND

Postoperative dissatisfaction after primary total knee arthroplasty (TKA) that requires additional care or readmission may impose a significant financial burden to healthcare systems. The purpose of the current study is to develop machine learning algorithms to predict dissatisfaction after TKA.

METHODS

A retrospective review of consecutive TKA patients between 2014 and 2016 from 1 large academic and 2 community hospitals was performed. Preoperative variables considered for prediction included demographics, medical history, flexion contracture, knee flexion, and outcome scores (patient-reported health state, Knee Society Score [KSS], and KSS-Function [KSS-F]). Recursive feature elimination was used to select features that optimized algorithm performance. Five supervised machine learning algorithms were developed by training with 10-fold cross-validation 3 times. These algorithms were subsequently applied to an independent testing set of patients and assessed by discrimination, calibration, Brier score, and decision curve analysis.

RESULTS

Of 430 patients, a total of 40 (9.0%) were dissatisfied with their outcome after primary TKA at a minimum of 2 years postoperatively. The random forest algorithm achieved the best performance in the independent testing set not used for algorithm development (c-statistic: 0.77, calibration intercept: 0.087, calibration slope: 0.74, Brier score: 0.082). The most important factors for predicting dissatisfaction were age, number of medical comorbidities, presence of one or more drug allergies, preoperative patient-reported health state score, and preoperative KSS.

CONCLUSION

The current study developed machine learning algorithms based on partially modifiable risk factors for predicting dissatisfaction after TKA. This model demonstrates good discriminative capacity for identifying those at greatest risk for dissatisfaction and may allow for preoperative health optimization.

No Differences in Hip Joint Space Measurements Between Weightbearing or Supine Anteroposterior Pelvic Radiographs

PURPOSE

To to assess whether there are any significant differences in hip joint space width (JSW) between weight-bearing versus supine pelvic radiographs.

METHODS

Standing and supine anteroposterior pelvic radiographs of 86 patients (146 hips) were included. Sample size was sufficiently powered to assess for equivalence between standing and supine films for JSW measurements made at the medial, lateral, and central aspects of the sourcil line. Measurements were made by 2 independent reviewers blinded to patient positioning. Each reviewer repeated a subset of the measurements to assess intra-rater reproducibility. Mean differences in joint space measurements between standing and supine radiographs were reported for each point of the sourcil. Intraclass correlation coefficients (ICCs) for inter and intra-rater reliability were also calculated.

RESULTS

There were no significant differences between JSW measurements made on standing and supine pelvic radiographs (P = .468). Furthermore, equivalence testing demonstrated statistical equivalence between standing and supine JSW measurements made based on an equivalence threshold of ±0.5 mm. Inter-rater reliability demonstrated good agreement with an overall ICC of 0.775 (95% confidence interval [CI] 0.734-0.809). Intra-rater reliability also demonstrated good agreement with ICCs of 0.84 (95% CI 0.758-0.889) and 0.798 (95% CI 0.721-0.851) for the 2 reviewers, respectively.

CONCLUSIONS

JSW measurements on standing and supine pelvic radiographs were not significantly different, and their inter-rater agreement and intra-rater reproducibility demonstrated good reliability and repeatability. Therefore, either may be used to assess JSW, including measurements that may impact treatment decisions for hip arthroscopy.

LEVEL OF EVIDENCE

Level III; retrospective comparative study.

Preparation Methods and Clinical Outcomes of Platelet-Rich Plasma for Intra-articular Hip Disorders: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background:

Despite its increasing use in the management of musculoskeletal conditions, questions remain regarding the preparation methods of platelet-rich plasma (PRP) and its clinical applications for intra-articular hip disorders, including femoroacetabular impingement syndrome (FAIS), labral pathology, and osteoarthritis (OA).

Purpose:

To systematically review and assess the preparation methods and clinical outcomes from randomized clinical trials (RCTs) on the use of PRP for intra-articular hip disorders.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

A systematic review in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed in September 2019. The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Ovid Medline, and Embase were queried for studies regarding the use of PRP to treat intra-articular hip disorders. Qualifying articles were English-language RCTs describing the use of PRP for intra-articular hip disorders, either as standalone treatment or surgical augmentation. Two authors independently assessed article eligibility. Data pertaining to patient characteristics, indication for treatment, PRP preparation method, follow-up period, and clinical outcomes were extracted. Study results were qualitatively reported and quantitatively compared using meta-analysis when appropriate.

Results:

Seven RCTs met inclusion criteria. Four studies described the use of PRP for hip OA and 3 utilized PRP at arthroscopy for FAIS and labral tears. Outcomes after PRP for OA demonstrated improvement in validated patient-reported outcome measures for up to 1 year; however, pooled effect sizes found no statistically significant difference between PRP and hyaluronic acid (HA) regarding pain visual analog scale scores at short-term (≤2 months; P = .27), midterm (4-6 months; P = .85), or long-term (1 year; P = .42) follow-up. When injected at arthroscopy, 1 study reported improved outcomes, 1 reported no difference in outcomes, and 1 reported worse outcomes compared with controls. The meta-analysis demonstrated no statistically significant difference on the modified Harris Hip Score (mHHS) between PRP and control cohorts at a minimum 1-year follow-up. There were considerable deficiencies and heterogeneity in the reporting of PRP preparation methods for both indications.

Conclusion:

Treatment of OA with PRP demonstrated reductions in pain and improved patient-reported outcomes for up to 1 year. However, there was no statistically significant difference between PRP and HA in pain reduction. Likewise, for FAIS and labral surgery there was no statistically significant difference in mHHS outcomes between patients treated with PRP and controls. Given the limited number of studies and variability in PRP preparations, additional high-quality randomized trials are warranted.

Indications and Outcomes for Arthroscopic Hip Labral Reconstruction With Autografts: A Systematic Review

Background: The acetabular labrum plays a major role in hip function and stability. The gold standard treatment for labral tears is labral repair, but in cases where tissue is not amenable to repair, reconstruction has been demonstrated to provide superior outcomes compared to debridement. Many types of grafts have been used for reconstruction with good to excellent outcomes. Autograft options include iliotibial band (ITB), semitendinosus, and indirect head of the rectus femoris tendon, while allografts have included fascia lata and gracilis tendon allografts.

Questions/Purposes: As allografts are not always readily available and have some inherent disadvantages, the aims of this systematic review were to assess (1) indications for labral reconstruction and (2) summarize outcomes, complications, and reoperation rates after arthroscopic labral reconstruction with autografts.

Methods: A systematic review of the literature was performed using six databases (PubMed, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Scopus, and Google Scholar) to identify studies reporting outcomes for arthroscopic labral reconstruction utilizing autografts, with a minimum follow-up of 1 year. Study design, patient demographics, autograft choice, complications, donor site morbidity, reoperation rates, conversion to arthroplasty, and patient reported outcomes were extracted and reported.

Results: Seven studies were identified for inclusion with a total of 402 patients (173 females, age range 16–72, follow-up range 12–120 months). The most commonly reported functional outcome score was the modified Harris Hip Score (mHHS), which was reported in six of seven studies. Preoperative mHHS ranged from 56 to 67.3 and improved postoperatively to a range of 81.4–97.8. Conversion to total hip arthroplasty and reoperation rates ranged from 0 to 13.2% and 0 to 11%, respectively. The most common indication for labral reconstruction was an irreparable labrum. Autografts utilized included ITB, hamstring tendons, indirect head of rectus femoris, and capsular tissue.

Conclusions: Arthroscopic autograft reconstruction of the acetabular labrum results in significant improvement in the short- and mid-term patient reported outcomes, for properly selected patients presenting with pain and functional limitation in the hip due to an irreparable labral injury.

Outcomes and Survivorship After Arthroscopic Treatment of Glenohumeral Arthritis: A Systematic Review

PURPOSE

To perform a systematic review of the literature describing outcomes, surgical procedures, and rates of conversion to arthroplasty after arthroscopic debridement of symptomatic primary glenohumeral osteoarthritis.

METHODS

The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Embase, and Ovid MEDLINE were queried. Articles without sufficiently detailed descriptions of the debridement procedure, those primarily describing cartilage resurfacing procedures, or those that did not report any postoperative outcomes were excluded. Study design, patient demographic characteristics, operative details, imaging findings, patient-reported outcomes, and rates of conversion to arthroplasty were compiled and reported. Assessment of bias was performed using the Methodological Index for Non-randomized Studies (MINORS) criteria.

RESULTS

A total of 371 patients (382 shoulders) in 8 studies were included. Patient sample sizes ranged from 8 patients (9 shoulders) to 98 patients (107 shoulders), and the samples were predominantly comprised of male patients (range, 57.1%-100%). The mean age and follow-up period ranged from 38 to 59 years and from 13.7 to 46.8 months, respectively. In studies reporting both preoperative and postoperative outcomes, improvements were found in American Shoulder and Elbow Surgeons scores (range, 8.6-22) and visual analog scale scores for pain (range, 0.4-3.8). There was significant heterogeneity (I² = 75%) in the rates of conversion to shoulder arthroplasty, which ranged from 4% to 42.4%, with the mean time to conversion ranging from 9 to 56 months. Study heterogeneity improved with subgroup analyses based on minimum duration of follow-up (>2 years) and preoperative radiographic inclusion criteria.

CONCLUSIONS

Arthroscopic treatment of glenohumeral osteoarthritis provides improvements in ROM and patient-reported outcomes with minimal complications. Despite variability in procedures and rates of subsequent conversion to arthroplasty, arthroscopic treatment appears to provide symptom relief and functional improvements in carefully selected patients. However, the longevity of improvement remains unclear, with studies including a longer duration of follow-up showing potential regression of symptom relief and increased rates of conversion to arthroplasty.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

What Is the Predictive Ability and Academic Impact of the Altmetrics Score and Social Media Attention?

BACKGROUND

Citation rate and journal impact factor have traditionally been used to assess research impact; however, these may fail to represent impact beyond the sphere of academics. Given that social media is now used to disseminate research, alternative web-based metrics (altmetrics) were recently developed to better understand research impact on social media. However, the relationship between altmetrics and traditional bibliometrics in orthopaedic literature is poorly understood.

PURPOSE

To (1) assess the extent that altmetrics correlate with traditional bibliometrics and (2) identify publication characteristics that predict greater altmetrics scores.

STUDY DESIGN

Cross-sectional study.

METHODS

Articles published in The American Journal of Sports Medicine (AJSM), The Journal of Bone and Joint Surgery, Clinical Orthopaedics and Related Research, Acta Orthopaedica, and Knee Surgery, Sports Traumatology, Arthroscopy between January 2016 and December 2016 were analyzed. Among the extracted publication characteristics were journal, number of authors, geographic region of origin, highest degree of first author, study subject and design, sample size, conflicts of interest, and level of evidence; number of references, institutions, citations, tweets, Facebook mentions, and news mentions; and Altmetric Attention Score (AAS). Multivariate regressions were used to determine (1) publication characteristics predictive of AAS and social media attention (mentions on Twitter, Facebook, and the news) and (2) the relationship between AAS and citation rate.

RESULTS

A total of 496 published articles were included, with a mean AAS of 8.6 (SD, 31.7; range, 0-501) and a mean citation rate of 15.0 (SD, 16.1; range, 0-178). Articles in AJSM (β = 19.9; P < .001), publications from North America (β = 8.5; P = .033), and studies concerning measure validation/reliability (β = 25.5; P = .004) were independently associated with higher AAS. Greater AAS score significantly predicted a greater citation rate (β = 0.16; P < .0001). The citation rate was an independent predictor of greater social media attention on Twitter, Facebook, and the news (odds ratio range, 1.02-1.03; P < .05 all).

CONCLUSION

AAS had a significant positive association with citation rates of articles in 5 high-impact orthopaedic journals. Articles in AJSM, studies concerning measure validation and reliability, and publications from North America were positively associated with greater AAS. A greater number of citations was consistently associated with publication attention received on social media platforms.