I can't get no satisfaction after my total knee replacement: rhymes and reasons

Methodological Assessment of the 100 Most-Cited Articles in Total Knee Arthroplasty in the Last Decade Compared to the All-Time List

BACKGROUND

Recent advances in total knee arthroplasty (TKA) have been driven by a growing focus on evidence-based medicine. This transition is reflected in the critical appraisal of both, the quality of work and the potential impact on the orthopedic community. The purpose of our study was to (1) identify the top 100 most-cited articles in TKA in the last decade and from all-time, and (2) compare methodological rigor of the most-cited articles in TKA in the last decade to articles all-time by level of evidence.

METHODS

The top 100 cited articles were recorded for manuscripts from the last decade, January 1, 2012 to December 31, 2022, and manuscripts from all-time for TKA. We collected authors, year of publication, journal of the article, country of origin of authors, article type (basic science article, clinical research article), level of evidence, methodological index for non-randomized studies score, physiotherapy evidence database scale, and citation density (total citations/years published).

RESULTS

The largest number of studies for all-time TKA (53.0%) and decade TKA (42.0%) were Level III. The average methodological index for non-randomized studies score for comparative studies was 18.7 for all-time TKA and 20.7 for decade TKA (P < .001). The average physiotherapy evidence database score was 6.1 for all-time TKA and 8.1 for decade TKA (P > .05). The highest citation density for all-time TKA was 111 and for past decade was 63. The number of level II studies in TKA increased from 19.0% from all time to 38.0% from the last decade (P < .05).

CONCLUSIONS

Our findings of improved methodologies over time reflect positive steps toward evidence-based practice in TKA. A continued focus on producing methodologically sound studies may guide evidence-based clinical decision-making.

A Comprehensive Approach to PROMs in Elective Orthopedic Surgery: Comparing Effect Sizes across Patient Subgroups

Background: There is limited knowledge regarding the comparative patient-reported outcomes (PROMs) and effect sizes (ESs) across orthopedic elective surgery. Methods: All patient data between January 2020 and December 2022 were collected, and treatment outcomes assessed as a PROM difference between baseline and one-year follow-up. The cohort was divided into subgroups (hand, elbow, shoulder, spine, hip, knee, and foot/ankle). The PROM ESs were calculated for each patient separately, and patients with ES > 0.5 were considered responders. Results: In total, 7695 patients were operated on. The mean ES across all patient groups was 1.81 (SD 1.41), and the largest ES was observed in shoulder patients and the smallest in hand patients. Overall, shoulder, hip, and knee patients had a larger ES compared to hand, spine, and foot/ankle patients (p < 0.0001). The proportion of positive responders ranged between 91-94% in the knee, shoulder, and hip, and 69-70% in the hand, spine, and foot/ankle subgroups. Conclusions: The ESs are generally high throughout elective orthopedic surgery. However, based on our institutional observations, shoulder, hip, and knee patients experience larger treatment effects compared to hand, spine, and foot/ankle patients, among whom there are also more non-responders. The expected treatment outcomes should be clearly communicated to patients when considering elective surgery. Because of the study limitations, the results should be approached with some caution.

What's important for recovery after a total knee replacement? A systematic review of mixed methods studies

BACKGROUND

Understanding how patients perceive and prioritise various aspects of recovery following total knee replacement, including pain, function and return to activity, will help clinicians in pre-operative consultations by ensuring they effectively address patient concerns and managing their expectations.

AIMS

The aim of this study is to identify aspects of recovery that are important to people after a total knee replacement.

METHODS

Studies were identified from Medline, Embase, PsycInfo, Cochrane Library and Web of Science. This mixed methods review included all original study types (quantitative, qualitative, discrete choice experiments and mixed methods design). Reviews and non-peer-reviewed publications were excluded. Studies with participants (age ≥ 18 years) who had a primary TKR for osteoarthritis were included. Studies of people with unicompartmental knee, patella-femoral or revision knee replacement were excluded. Recovery attributes were extracted from individual papers and grouped into recovery themes.

RESULTS

A total of 23 studies with 8404 participants and 18 recovery themes were developed. The most frequently identified overarching theme was pain, followed by activities of daily living, mobility (walking), recreational activities, specific functional movements of the knee, use of walking aids, sexual activity and range of motion of the knee. Medical complications were an infrequently reported theme, however, was deemed to be high importance.

CONCLUSIONS

Reducing pain, returning of activities and daily living and mobility are the three most frequently reported recovery domains for people after TKR. Clinicians should be aware of recovery themes, to ensure they are explored sufficiently when consenting for a TKR. Future research should aim to determine the relative importance of these attributes compared to each other. Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021253699.

Who Are the Anatomic Outliers Undergoing Total Knee Arthroplasty? A Computed Tomography-Based Analysis of the Hip-Knee-Ankle Axis Across 1,352 Preoperative Computed Tomographies Using a Deep Learning and Computer Vision-Based Pipeline

BACKGROUND

Dissatisfaction after total knee arthroplasty (TKA) ranges from 15 to 30%. While patient selection may be partially responsible, morphological and reconstructive challenges may be determinants. Preoperative computed tomography (CT) scans for TKA planning allow us to evaluate the hip-knee-ankle axis and establish a baseline phenotypic distribution across anatomic parameters. The purpose of this cross-sectional analysis was to establish the distributions of 27 parameters in a pre-TKA cohort and perform threshold analysis to identify anatomic outliers.

METHODS

There were 1,352 pre-TKA CTs that were processed. A 2-step deep learning pipeline of classification and segmentation models identified landmark images and then generated contour representations. We used an open-source computer vision library to compute measurements for 27 anatomic metrics along the hip-knee axis. Normative distribution plots were established, and thresholds for the 15th percentile at both extremes were calculated. Metrics falling outside the central 70th percentile were considered outlier indices. A threshold analysis of outlier indices against the proportion of the cohort was performed.

RESULTS

Significant variation exists in pre-TKA anatomy across 27 normally distributed metrics. Threshold analysis revealed a sigmoid function with a critical point at 9 outlier indices, representing 31.2% of subjects as anatomic outliers. Metrics with the greatest variation related to deformity (tibiofemoral angle, medial proximal tibial angle, lateral distal femoral angle), bony size (tibial width, anteroposterior femoral size, femoral head size, medial femoral condyle size), intraoperative landmarks (posterior tibial slope, transepicondylar and posterior condylar axes), and neglected rotational considerations (acetabular and femoral version, femoral torsion).

CONCLUSIONS

In the largest non-industry database of pre-TKA CTs using a fully automated 3-stage deep learning and computer vision-based pipeline, marked anatomic variation exists. In the pursuit of understanding the dissatisfaction rate after TKA, acknowledging that 31% of patients represent anatomic outliers may help us better achieve anatomically personalized TKA, with or without adjunctive technology.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

Exploration of adverse consequences of total knee arthroplasty by patients and knee specialists: a qualitative study

Objectives

A successful outcome according to the knee specialist is not a guarantee for treatment success as perceived by patients. In this study, we aimed to explore outcome expectations and experiences of patients with OA before and after total knee arthroplasty (TKA) surgery and knee specialists that might contribute to the negative appraisal of its effect, and differences in views between patients and knee specialists.

Methods

Semi-structured interviews were held in Belgium and the Netherlands. Twenty-five patients (2 without indications for TKA, 11 on the waiting list for TKA and 12 postoperative TKA) and 15 knee specialists (9 orthopaedic surgeons, 1 physician assistant, 1 nurse practitioner and 4 physiotherapists) were interviewed. Conversations were audio recorded, transcribed verbatim, and analysed using thematic analysis following the grounded theory approach. Separate analyses were conducted for patients and knee specialists.

Results

Patients were focused on the arduous process of getting used to the prosthesis, lingering pain, awareness of the artificial knee and limitations they experience during valued and daily activities, whereas knee specialists put emphasis on surgical failure, unexplained pain, limited walking ability and impairments that limit the physical functioning of patients.

Conclusion

This study provides a comprehensive overview of potential adverse consequences from the perspective of both patients and knee specialists. Improving patients' awareness and expectations of adaptation to the knee prosthesis needs to be considered.

Novel morphogenic knee implant delivers comparable mid-term outcomes as compared to conventional non-morphogenic implants

INTRODUCTION

Conventional total knee arthroplasty (C-TKA) implants have well-established mid- and long-term outcomes. The novel TKA (N-TKA) implants provide morphogenic implant components with smaller size increments to facilitate anatomical replication. The aim of the study is to evaluate if these advantages provides better clinical outcomes.

MATERIALS AND METHODS

Registry data prospectively collected within a single institution from 2014 to 2018 was reviewed and propensity score matching was performed to match C-TKA to N-TKA. 70 pairs of cruciate retaining (CR) TKA and 116 pairs of posterior stabilized (PS) TKA were identified. Range of motion, SF-36, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS) and Oxford Knee Score (OKS) were assessed preoperatively, 6 and 24 months postoperatively. Satisfaction was assessed 6 and 24 months postoperatively. Independent T test was performed for parametric data, whereas Wilcoxon rank-sum analysis was performed for non-parametric data.

RESULTS

Both C-TKA and N-TKA cohorts demonstrated statistically significant improvement for KSKS, KSFS, OKS and SF-36 at 6 and 24 months postoperatively. C-TKA CR patients had better flexion at 6 months as compared to N-TKA CR (108.7° versus 98.3°, respectively, p = 0.046). At 24 months, there was no difference between C-TKA and N-TKA for range of motion, KSKS, KSFS, OKS and SF-36 PCS, regardless of insert type (p > 0.05).

CONCLUSIONS

Both models showed great postoperative improvements in KSFS, KSKS, OKS and SF-36 and have comparable early and mid-term outcomes, suggesting that N-TKAs are suitable substitutes for C-TKA. Longer follow-up studies are required to evaluate the long-term outcomes of N-TKAs.

LEVEL OF EVIDENCE

lll.

Reverse coronal deformity: use of robotic total knee arthroplasty for identification and correction

BACKGROUND

Despite continued advances in techniques and implant designs, a population of patients who are dissatisfied after total knee arthroplasty (TKA) remains. During robotic-assisted arthroplasty, real-time intraoperative assessment of patient knee alignment is performed. Here, we assess the prevalence of an under-appreciated deformity, reverse coronal deformity (RCD), and the benefits of utilizing robotic-assisted knee arthroplasty to help correct this dynamic deformity.

METHODS

A retrospective study evaluating patients undergoing robotic-assisted cruciate-retaining TKA was performed. Intraoperative measurements were obtained using tibial and femoral arrays to assess coronal plane deformity at full extension and at 90° flexion. RCD was defined as ≥ 2° varus in knee extension that reversed to ≥ 2° valgus in flexion, or vice-versa. Coronal plane deformity was then reassessed after robotic-assisted bony resection and implant placement.

RESULTS

Of 204 patients that underwent TKA, 16 patients (7.8%) were found to have RCD, with 14 patients (87.5%) transitioning from varus in extension to valgus in flexion. The average coronal deformity was 7.75°, with a maximum of 12°. These improved to an average coronal change of 0.93° post-TKA. Final medial and lateral gaps were all balanced to within 1° in extension and flexion. Another 34 patients (16.7%) had ≥ 5° change in coronal plane deformity from extension to flexion (average 6.39°), however, did not experience a reversal of their coronal deformity. Outcomes were assessed with KOOS Jr. scores postoperatively.

CONCLUSION

Computer and robotic assistance were utilized to demonstrate the prevalence of RCD. We also demonstrated accurate identification and successfully balancing of RCD utilizing robotic-assisted TKA. An increased awareness of these dynamic deformities could aid surgeons in proper gap balancing even in the absence of navigation and robotic-assisted surgery.

Optimizing Asymmetric Native Knee Flexion Gap Balance Promotes Superior Outcomes in Primary Total Knee Arthroplasty

INTRODUCTION

Replicating native knee kinematics remains the ultimate goal of total knee arthroplasty (TKA). Technology, such as robotics, provides robust intraoperative data; however, no evidence-based targets currently exist for improved clinical outcomes. Furthermore, some surgeons target a rectangular flexion space in TKA unlike the native knee. This study evaluated the effect of in vivo flexion gap asymmetry on patient-reported outcome measures (PROMs) in contemporary TKA.

METHODS

In vivo tibiofemoral joint space dimensions were measured during 129 TKAs using a calibrated tension device before and after complete posterior cruciate ligament resection. PROMs were compared based on the final dimensions and the change in flexion gap dimensions at 90° of flexion: (1) equal laxity, (2) lateral laxity, and (3) medial laxity. Groups did not differ by demographics ( P ≥ 0.347), clinical follow-up ( P = 0.134), tibiofemoral alignment ( P = 0.498), or preoperative PROMs ( P ≥ 0.093). Mean follow-up for the cohort was 1.5 years (range, 1-3).

RESULTS

Pain with climbing stairs, pain while standing upright, and knees "always feeling normal" scores were superior for patients with equal or lateral laxity compared with medial laxity ( P ≤ 0.064). Pain with level walking, University of California Los Angeles activity level, KOOS JR, and satisfaction scores also tended to be superior for patients with equal or lateral laxity, although it lacked statistical significance ( P ≥ 0.111).

DISCUSSION

Results of this study suggest that patients with either an equally tensioned rectangular flexion space or with later-flexion lateral laxity after posterior cruciate ligament resection may achieve superior PROMs. Findings support the clinical benefit of facilitating posterolateral femoral roll back in flexion, which mimics native knee kinematics and further helps define targets for advanced technology.

Robotic-Assisted Total Knee Arthroplasty: What are Patients' Perspectives, Understanding and Expectations?

BACKGROUND

The rate of using robotic-assisted total knee arthroplasty (RA-TKA) has increased markedly. Understanding how patients view the role of robotics during total knee arthroplasty (TKA) informs shared decision making and facilitate efforts to appropriately educate patients regarding the risks and benefits of robotic assistance.

METHODS

A self-administered questionnaire was completed by 440 potential TKA patients at the time of their surgery scheduling. Participants answered 25 questions regarding RA-TKA, socioeconomic factors, and their willingness to pay (WTP) for RA-TKA. Logistic regressions were used to determine if population characteristics and surgeon preferences influenced the patients' perceptions of RA-TKA.

RESULTS

There were 39.7% of respondents who said that they had no knowledge regarding RA-TKA. Only 40.7% of participants had expressed a desire for RA-TKA to be used. There were 8.7% who were WTP extra for the use of RA-TKA. Participants believed that the main 3 benefits of RA-TKA compared to conventional methods were: more accurate implant placement (56.2%); better results (49.0%); and faster recovery (32.1%). The main 3 patient concerns were harm from malfunction (55.2%), reduced surgeon role in the procedure (48.1%), and lack of supportive research (28.3%). Surgeon preference of RA-TKA was associated with patient's willingness to have RA-TKA (odds ratio 4.60, confidence interval 2.98-7.81, P < .001), and with WTP extra for RA-TKA (odds ratio 2.05, confidence interval: 1.01-4.26, P = .049).

CONCLUSION

Patient knowledge regarding RA-TKA is limited. Nonpeer-reviewed online information may make prospective TKA candidates vulnerable to misinformation and aggressive advertising. The challenge for orthopaedic surgeons is to re-establish control and reliably educate patients about the proven advantages and disadvantages of this emerging technology.

Not all questions are created equal: the weight of the Oxford Knee Scores questions in a multicentric validation study

BACKGROUND

The Oxford Knee Score (OKS) has been designed for patients with knee osteoarthritis and has a widespread use. It has 12 questions, with each question having the same weight for the overall score. Some authors have observed a significant ceiling effect, especially when distinguishing slight postoperative differences. We hypothesized that each questions' weight will depend significantly on the patient's sociodemographic data and lifestyle.

METHODS

In this international multicentric prospective study, we included patients attending a specialist outpatient knee clinic. Each patient filled out 3 questionnaires: (a) demographic data and data pertaining to the OKS, (b) the standard OKS, and (c) the patient gave a mark on the weight of the importance of each question, using a 5-point Likert scale (G OKS). Linear regression models were used for the analysis.

RESULTS

In total 203 patients (106 female and 97 male) with a mean age of 64.5 (±12.7) years and a mean body mass index (BMI) of 29.34 (±5.45) kg/m2 were included. The most important questions for the patients were the questions for pain, washing, night pain, stability, and walking stairs with a median of 5. In the regression models, age, gender, and driving ability were the most important factors for the weight of each of the question.

CONCLUSION

The questions in the OKS differ significantly in weight for each patient, based on sociodemographic data, such as age, self-use of a car, and employment. With these differences, the Oxford Knee Score might be limited as an outcome measure. Adjustment of the OKS that incorporates the demographic differences into the final score might be useful if the ceiling effect is to be mitigated.

LEVEL OF EVIDENCE

Level II prospective prognostic study.

Magnetic Resonance Safety Evaluation of a Novel Alumina Matrix Composite Ceramic Knee and Image Artifact Comparison to a Metal Knee Implant of Analogous Design

Background

Image artifacts caused by metal knee implants in 1.5T and 3T magnetic resonance imaging (MRI) systems complicate imaging-based diagnosis of the peri-implant region after total knee arthroplasty. Alternatively, metal-free knee prostheses could effectively minimize MRI safety hazards and offer the potential for higher quality diagnostic images.

Methods

A novel knee arthroplasty device composed of BIOLOX delta, an alumina matrix composite (AMC) ceramic, was tested in a magnetic resonance (MR) environment. American Society for Testing and Materials test methods were used for evaluating magnetically induced displacement force, magnetically induced torque, radiofrequency-induced heating, and MR image artifact.

Results

Magnetically induced displacement force and magnetically induced torque results of the AMC ceramic knee indicated that these effects do not pose a known risk in a clinical MR environment, as assessed in a 3T magnetic field. Moreover, minimal radiofrequency-induced heating of the device was observed. In addition, the AMC ceramic knee demonstrated minimal MR image artifacts (7 mm) in comparison to a cobalt-chromium knee (88 mm). The extremely low magnetic susceptibility of AMC (2 ppm) underlines that it is a nonmetallic and nonmagnetic material well suited for the manufacturing of MR Safe orthopaedic implants.

Conclusions

The AMC ceramic knee is a novel metal-free total knee arthroplasty device that can be regarded as MR Safe, as suggested by the absence of hazards from the exposure of this implant to a MR environment. The AMC ceramic knee presents the advantage of being scanned with superior imaging results in 3T MRI systems compared to alternative metal implants on the market.

Coronal and Sagittal Component Position in Contemporary TKA: Targeting Native Alignment Optimizes Clinical Outcomes

BACKGROUND

Advanced technologies, like robotics, provide enhanced precision for implanting total knee arthroplasty (TKA) components; however, optimal component position and limb alignment remain unknown. This study sought to identify sagittal and coronal alignment targets that correlate with minimal clinically important differences (MCID) in patient-reported outcome measures (PROMs).

METHODS

A total of 1,311 consecutive TKAs were retrospectively reviewed. Posterior tibial slope (PTS), femoral flexion (FF), and tibio-femoral alignment (TFA) were measured radiographically. Patients were grouped based on whether they achieved multiple MCIDs for PROM scores. Classification and regression tree machine learning models were utilized to identify optimal alignment zones. Mean follow-up was 2.4 years (range, 1 to 11).

RESULTS

The change in PTS and postoperative TFA were most predictive for achieving MCIDs in 90% of the models. Approximating native PTS within 4° correlated with MCID achievement and superior PROMs. Preoperative varus and neutral aligned knees were more likely to meet MCIDs and superior PROM scores when not overcorrected into valgus postoperatively (≥ 7°). Preoperative valgus aligned knees correlated with MCID achievement when postoperative TFA was not overcorrected into substantial varus (<0°). Albeit less impactful, FF ≤ 7° correlated with MCID achievement and superior PROMs regardless of preoperative alignment. Sagittal and coronal alignment measurements had moderate to strong interactions in 13 of 20 models.

CONCLUSION

Optimized PROM MCIDs correlated with approximating native PTS while maintaining similar preoperative TFA and incorporating moderate FF. Study findings demonstrate interactions between sagittal and coronal alignment which may optimize PROMs, highlighting the importance of three-dimensional implant alignment targets.

Patient-Reported Outcomes and Risk Factors for Decreased Improvement after Patellofemoral Arthroplasty

Patellofemoral arthroplasty (PFA) is acknowledged as the method for the treatment of isolated patellofemoral osteoarthritis (PFOA). Few previous studies have assessed the patient-reported outcomes (PROs) and risk factors of less improvement of PROs in patients undergoing PFA. A retrospective analysis was performed, including all patients who had undergone PFA. Pre- and postoperative PROs included the Oxford Knee Score (OKS) and Kujala score. Univariate and multivariate statistical analyses were performed to assess influencing factors of less improvement of PROs including the demographic factors (gender, age, body mass index, smoking, opioid usage, and duration of symptoms [DOSs]), surgical factors (concomitant surgery), and imaging factors (trochlear dysplasia [TD], patellar height, the degree of PFOA). A total of 46 PFAs were analyzed with a mean follow-up of 37 ± 7 months. The mean age at surgery was 61.1 ± 7.7 years. Patients showed significant improvement in all PROs (p < 0.001). Patients with TD preoperatively have greater improvement in OKS and Kujala score postoperatively (19.2 ± 5.0 vs. 23.1 ± 3.6, p = 0.038). Longer DOSs (≥1 year) had a greater mean improvement in OKS and Kujala score (p = 0.011 and p = 0.000). According to the measurement of patella height, patients with patella alta (Caton-Deschamps index [CDI] ≥1.3) showed less improvement in both OKS and Kujala score (p = 0.000 and p = 0.002). PFA is a safe and efficient surgery with good PROs. Patella alta with a CDI ≥1.3 and duration of preoperative symptoms ≤ 1 year were risk factors for decreased OKS and Kujala score improvement, while the preoperative presence of TD was significantly predictive factors for increased OKS improvement.

The Impact of Robotic-Assisted Total Knee Arthroplasty on Resident Training

BACKGROUND

As robotic-assisted total knee replacement (rTKA) continues to gain popularity, the impact of this technology on resident education remains unknown. The purpose of this study was to describe trainee experience and perceptions of rTKA and its effect on surgical training.

METHODS

Two hundred and twenty two senior orthopaedic residents attending a national board review course completed a 17-question survey regarding their experience and perceptions regarding rTKA. Mean and standard deviations were calculated for Likert scale questions, and bivariate analyses were utilized to compare answer groups.

RESULTS

Seventy percent of respondents reported exposure to rTKA during their training. Of those with robotic exposure, 20% reported that greater than half of their TKA experience involved robotics. Only 29% percent agreed that robotics improved outcomes, whereas 21% disagreed and the remainder were unsure. Over half of respondents agreed that robotics are used primarily for marketing purposes. Of those who trained with rTKA, 45% percent believed that robotics improved their understanding of the surgical procedure; however, 25% felt robotics negatively compromised their training with traditional instrumentation. Higher robotic case exposure (P = .001) and attending an industry-sponsored course (P = .02) was associated with the belief that robotics improved outcomes. Robotic case volume and percentage was associated with the belief that robotics improved understanding of the surgical procedure, however, it also was associated with reduced comfort performing traditional knee arthroplasty (P = .001).

CONCLUSION

Current resident training experience varies greatly within the United States with regards to rTKA. While exposure to rTKA may be beneficial for a well-rounded surgical education, over-exposure likely results in decreased comfort with traditional instrumentation.

Disease burden of and expectations from surgery in patients prior to total knee arthroplasty: Results of the prospective FInGK study

BACKGROUND

Disease burden in patients prior to total knee arthroplasty (TKA) varies widely between studies and countries. We aimed to characterize individuals undergoing TKA and examine their expectations from the surgery, focusing on variations in disease burden.

METHODS

Consecutive patients undergoing primary TKA in a German university hospital were recruited. A questionnaire including information on disease burden, preoperative expectations from surgery, health care utilization, demography, and socioeconomics was collected one day prior to surgery and linked to data from medical records. Patients were categorized into disease burden quartiles using the Western Ontario and McMaster Universities Osteoarthritis Index' (WOMAC) total score. Subsequently, study population's characteristics and expectations from surgery were analyzed stratified by disease burden.

RESULTS

A total of 196 patients were included (41 % male; mean age: 68.2 years). The median WOMAC was 52.0 (IQR: 41.0-58.0). Patients in Q1 were more often males (Q1: 63 % vs Q4: 29 %) and had a shorter duration of complaints with the impaired knee. They were also less restricted in social participation, reported less often signs of depression, and were less often treated with physiotherapy (Q1: 27 % vs Q4: 54 %). Furthermore, expectations from surgery were highest in patients with a low disease burden.

CONCLUSION

We found large variations in disease burden with a considerable number of patients undergoing TKA whose functional capacity is still maintained and for which guideline-recommended conservative treatment options are not fully exhausted. Further research on this subgroup as well as establishing an international consensus on specific thresholds for TKA indication are needed.

Higher Dissatisfaction Rate Following Revision Compared With Primary Total Knee Arthroplasty: 1-Year Follow-up of 2151 Primary and 235 Aseptic Revision Surgeries

Postoperative patient satisfaction is related to preoperative expectations. Information regarding expected results following surgery is therefore important. This study evaluated patient-reported outcome measures (PROMs) and patient satisfaction up to 1 year after primary and aseptic revision total knee arthroplasty (TKA). The study included 2151 primary and 235 aseptic revision TKA surgeries conducted between 2010 and 2018. Pain, Knee Injury and Osteoarthritis Outcome Score-Physical Function-Short Form and European Quality of Life-5 Dimension surveys were recorded preoperatively and at 8 weeks and 1 year. To determine satisfaction, patients were asked to rate their knee function compared with that before surgery and to answer whether they would undergo the surgery again given their current knowledge. Patients who had primary TKA improved in all PROMs in each follow-up up to 1 year, whereas patients who had revision TKA showed improvement at 8 weeks with no further improvement at 1 year. In terms of patient satisfaction, 88% of patients in the primary TKA group reported better knee function, and 87% were willing to have the surgery again at 1 year; the proportions were lower for patients who underwent revision TKA (66% and 68%, respectively). Aseptic revision TKA demonstrates inferior PROMs compared with those of primary TKA 1 year after surgery, and more than 30% of the patients who underwent revision TKA stated that they would not have their TKA revised or were uncertain, given the outcome of the procedure. Thus, patients who are candidates for revision TKA should be informed to expect less of an improvement following revision surgery than with the primary TKA. Our findings can facilitate the shared decision-making process by surgeons and patients based on realistic expectations of surgical outcomes. [Orthopedics. 2023;46(1):e52-e57.].

The Desired Oxford Knee Score Obtained Before Total Knee Arthroplasty is Predictive of the Postoperative Oxford Knee Score: A Prospective Study

BACKGROUND

The relationship between patient expectations and patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA) is not well understood. The purpose of the study was to test the influence of desired knee function on postoperative perceived knee function 1 year after TKA.

METHODS

A total of 102 patients undergoing primary TKA were available for data analyses. Preoperatively, patients completed the Oxford Knee Score (OKS) twice, one representing preoperative function (preoperative OKS); the second representing desired function after TKA (desired OKS). Western Ontario and McMaster Universities Arthritis Index (WOMAC), University of California, Los Angeles (UCLA) Activity score, Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES), Patient Health Questionnaire-9, and EuroQol-visual analogue scales were obtained preoperatively. One year after surgery, all surveys besides the UCLA activity score and HSS-KRES were repeated. The associations between postoperative OKS and WOMAC versus desired OKS and HSS-KRES were assessed using multivariable linear regression models, wherein linear regression coefficients represent the additive effect on the mean postoperative PROM.

RESULTS

The desired OKS was independently associated with the postoperative OKS (linear regression coefficient = 0.43; P = .011), that is, each point increase in desired OKS yielded a 0.43 increase in postoperative OKS. The preoperative OKS showed no association with postoperative PROMs. Desired OKS was correlated with postoperative WOMAC (coefficient = -0.67; P = .014). The HSS-KRES was not associated with the postoperative OKS (coefficient = -0.005; P = .965) or WOMAC (coefficient = 0.18; P = .288).

CONCLUSION

In TKA patients, higher preoperative desired function predict greater postoperative PROMs. Effects of preoperative expectations on outcomes are independent of patient demographics or preoperative function.

Demographics are no clinically relevant predictors of patient-reported knee osteoarthritis symptoms - Comprehensive multivariate analysis

Aims & objectives

In clinical practice, arthroplasties are predominantly indicated by clinical and radiological assessment of osteoarthritis. Pain and function are individually considered, but a comprehensive analysis of differences in symptom reporting by pre-operative factors is lacking. In the present study, we determined differences in patient reported outcome measures between demographic groups among patients admitted to total knee arthroplasty.

Materials & methods

Between 2010 and 2019, we collected pre-operative Oxford Knee Scores, Western Ontario and McMaster University Osteoarthritis Index, quality of life in 2555 patients undergoing primary, osteoarthritis-indicated total knee arthroplasty at Patients were categorized by sex, age (<70, 70-80, >80 years), body mass index (BMI <25, 25-30, 30-35, >35 kg/m2), American Society of Anesthesiologists -classification (ASA 1, 2, ≥3) and Charnley score (A, B1, B2, C). Symptom scores (median, IQR) were compared using bivariate and multivariate methods.

Results

The cohort was 60% female, 70.0 years old (69.4-70.1), and BMI was 28.9 kg/m2 (29.6-30.0). As compared to bivariate analyses, between-group differences in multivariate analyses were consistently smaller. BMI and sex remain significant predictors after adjustment for age, ASA, and Charnley. Age, ASA, and Charnley were no independent predictors of symptom scores. A group of patients (30%) reported no physical dysfunction, and less symptom severity in pain and stiffness.

Conclusion

This study is the first to show that differences in symptom reporting between demographic groups are partly colinear, and are negligible for prediction of symptoms. Lastly, for a significant proportion of patients, patient-reported outcome measures do not adequately present disease severity.

Long-term cost-effectiveness of matrix-associated chondrocyte implantation in the German health care system: a discrete event simulation

INTRODUCTION

Cartilage defects in the knee can be caused by injury, various types of arthritis, or degeneration. As a long-term consequence of cartilage defects, osteoarthritis can develop over time, often leading to the need for a total knee replacement (TKR). The treatment alternatives of chondral defects include, among others, microfracture, and matrix-associated autologous chondrocyte implantation (M-ACI). The purpose of this study was to determine cost-effectiveness of M-ACI in Germany with available mid- and long-term outcome data, with special focus on the avoidance of TKR.

MATERIALS AND METHODS

We developed a discrete-event simulation (DES) that follows up individuals with cartilage defects of the knee over their lifetimes. The DES was conducted with a status-quo scenario in which M-ACI is available and a comparison scenario with no M-ACI available. The model included 10,000 patients with articular cartilage defects. We assumed Weibull distributions for short- and long-term effects for implant failures. Model outcomes were costs, number of TKRs, and quality-adjusted life years (QALYs). All analyses were performed from the perspective of the German statutory health insurance.

RESULTS

The majority of patients was under 45 years old, with defect sizes between 2 and 7 cm² (mean: 4.5 cm²); average modeled lifetime was 48 years. In the scenario without M-ACI, 26.4% of patients required a TKR over their lifetime. In the M-ACI scenario, this was the case in only 5.5% of cases. Thus, in the modeled cohort of 10,000 patients, 2700 TKRs, including revisions, could be avoided. Patients treated with M-ACI experienced improved quality of life (22.53 vs. 21.21 QALYs) at higher treatment-related costs (18,589 vs. 14,134 € /patient) compared to those treated without M-ACI, yielding an incremental cost-effectiveness ratio (ICER) of 3376 € /QALY.

CONCLUSION

M-ACI is projected to be a highly cost-effective treatment for chondral defects of the knee in the German healthcare setting.

Immunohistochemical analysis of the quadriceps femoris muscle before and after total knee arthroplasty

BACKGROUND

The number of total knee arthroplasties (TKA) has increased steadily with the aging of the population. This surgical procedure is recognized for its success in pain relief and restoration of knee function. However, decreased quadriceps femoris (QF) muscle strength after TKA is frequently observed but with unknown etiology. Evidence suggests that the location of the operative incision (i.e., surgical access) can influence QF muscle structure and function. The present study aimed to assess the fiber type composition, structure and assembly of the QF's vastus medialis (VM) and vastus lateralis (VL) muscles before and after TKA.

METHODS

Muscle biopsies (VM and VL muscles) were collected from patients previously submitted to TKA via the medial parapatellar route and undergoing TKA revision (main group, n = 9) and patients with osteoarthrosis (OA) who were due to undergo TKA (control group: n = 18). The biopsied muscle tissue was prepared, stored, and then sectioned in a cryostat at -25 °C. The tissue sections were evaluated using routine staining techniques in pathological anatomy and histochemistry.

RESULTS

The normal mosaic pattern of the medial and lateral knee muscles was observed in the main and control groups, with no evidence of peripheral nerve damage. Notably, 88.9 % of the patients exhibited mild to severe VL atrophy, while only 11.1 % of patients in the control group presented this feature (P < 0.001).

CONCLUSIONS

The medial parapatellar incision for TKA surgical access does not generate definitive morphological changes in the VM and VL muscle fibers but may contribute to VL atrophy.

Decision regret after primary hip and knee replacement surgery

BACKGROUND

Decision regret (DR) is a recognised patient centered outcome measure following a therapeutic intervention. This study aimed to measure DR following primary total hip and knee arthroplasty (THA/TKA), to assess for differences between these patients and explore possible contributory factors.

METHOD

DR was measured using the DR scale in a group of THA and TKA patients, between February 2017 and December 2018, who had made a decision to have joint replacement surgery within the previous year and were able to reflect on their outcomes.

RESULTS

On analysis a significantly greater proportion of TKA patients reported moderate or severe (Mod/Sev) DR [17.1% (56/328)] compared to THA patients [4.8% (18/376)]. Conversely, a significantly reduced proportion of TKA patients reported having No DR [42.1% (138/328)] compared to THA patients [66.7% (251/376)]. On multivariate logistic regression analysis joint replacement type (TKA/THA) and change in Oxford score were significant predictors of DR with gender, age, BMI and ASA grade not significantly associated. TKA patients were more than twice as likely to have Mod/Sev DR compared THA patients (Odds Ratio = 2.33 (95% CI 1.24-4.39)). Patients with poorer improvements in pain and function 1-year post-operatively (measured by Oxford scores) reported greater levels of DR.

CONCLUSION

TKA patients were significantly more likely to report greater levels of DR 1-year following surgery compared to THA patients. For both TKA and THA patients, greater levels of DR were associated with poorer Oxford scores. The use of decision aids to reduce post-operative DR in joint replacement patients should be examined especially for knee replacement patients.

Early Outcomes of Dual-Pivot Total Knee Replacement Compared to an Ultracongruent Design

BACKGROUND

With a quest to optimize outcomes, there have been significant advancements in modern designs of total knee implants, attempting to mimic the natural knee motion and feel. One such new design reproducing the medial and lateral knee pivot is a dual-pivot (DP) knee. In the present study, we endeavored to compare the performance of the DP knee vis-a-vis an ultracongruent (UC) Knee design.

METHODS

This prospective cohort study was performed in a joint replacement center of a tertiary care military hospital. We enrolled 50 patients each in the DP knee group and the UC knee group and assessed knee flexion, patient-reported outcome (new Knee Society Score [nKSS]), patient performance (Delaware Osteoarthritis Profile Score), and function (Forgotten Joint Score [FJS]) at 2 years of follow-up.

RESULTS

The nKSS was similar in the two groups. In the DP group, patients had significantly better improvement in the stair climb test (p = 0.026). In the UC group, timed up and go test was significantly better (p = 0.004). The gain in knee flexion was similar in the two groups: 26.3° ± 23.3° in the DP group and 27.5° ± 27.5° in the UC group (p = 0.930). Return to activity as judged by 2-year FJS was similar in both groups (p = 0.687).

CONCLUSIONS

Our study showed that the DP knee design had similar knee function to the UC knee. The DP knee design had significantly better stair climbing ability, whereas getting up from chair was better in the UC knee design. With comparable patient-reported outcome and possible differences in patient performance in terms of day-to-day activities, any future trial should focus on comparing patient performance.

Mitochondrial function, grip strength, and activity are related to recovery of mobility after a total knee arthroplasty

Low muscle quality and a sedentary lifestyle are indicators for a slow recovery after a total knee arthroplasty (TKA). Mitochondrial function is an important part of muscle quality and a key driver of sarcopenia. However, it is not known whether it relates to recovery. In this pilot study, we monitored activity after TKA using a wrist mounted activity tracker and assessed the relation of mitochondrial function on the rate of recovery after TKA. Additionally, we compared the increase in activity as a way to measure recovery to traditional outcome measures. Patients were studied 2 weeks before TKA and up to 6 months after. Activity was monitored continuously. Baseline mitochondrial function (citrate synthase and complex [CP] 1-5 abundance of the electron transport chain) was determined on muscle tissue taken during TKA. Traditional outcome measures (Knee Injury and Osteoarthritis Outcome Score [KOOS], timed up-and-go [TUG] completion time, grip, and quadriceps strength) were performed 2 weeks before, 6 weeks after, and 6 months after TKA. Using a multivariate regression model with various clinical baseline parameters, the following were significantly related to recovery: CP5 abundance, grip strength, and activity (regression weights 0.13, 0.02, and 2.89, respectively). During recovery, activity correlated to the KOOS-activities of daily living (ADL) score (r = 0.55, p = 0.009) and TUG completion time (r = -0.61, p = 0.001). Mitochondrial function seems to be related to recovery, but so are activity and grip strength, all indicators of sarcopenia. Using activity trackers before and after TKA might give the surgeon valuable information on the expected recovery and the opportunity to intervene if recovery is low.

The influence of obesity on functional outcomes and patient satisfaction 8 weeks after total knee arthroplasty: results of the prospective FInGK study

OBJECTIVES

To investigate obese versus non-obese subjects´ knee joint function, stiffness, pain, expectations, and outcome satisfaction before and two months after total knee arthroplasty (TKA).

METHODS

This study is a secondary analysis of data retrieved via a prospective single-centre cohort study investigating knee joint function and health care services utilization in patients undergoing TKA (FInGK Study). For the primary study, elective TKA patients were consecutively recruited between December 2019 and May 2021. Preoperative expectations, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), surgery outcome satisfaction, and sociodemographic variables were assessed via self-reported questionnaires. In the current study, obese (Body Mass Index (BMI) ≥ 30 kg/m²) versus non-obese (BMI < 30 kg/m²) subjects' data were exploratively compared before and two months after TKA. Multivariable logistic regression assessed factors associated with TKA satisfaction two months postoperatively. Linear regression evaluated factors associated with higher WOMAC change two months postoperatively.

RESULTS

A total of 241 subjects participated (response: 85.2%). Eighty-seven were non-obese (mean age: 70.7 years, 63.2% female) and 154 were obese (mean age: 67.1 years, 57.8% female). Obese subjects reported inferior pre- and postoperative pain and knee joint function compared to non-obese subjects. Yet, WOMAC scores of obese and non-obese subjects significantly improved from preoperative means of 52.6 and 46.8 to 32.3 and 24.4 after surgery, respectively. The only significant TKA satisfaction predictor was subjects' smoking status. Non-obesity and worse preoperative WOMAC scores were predictive of higher WOMAC change scores after two months.

CONCLUSION

Both obese and non-obese subjects reported significant symptom improvements. However, as obese subjects' short-term outcomes were still inferior, more research on TKA rehabilitation measures adapted to the needs of this growing patient group is warranted to maximize their benefits from TKA.

Eliciting Activity Goals With a Self-Administered Survey Among Patients With Hip or Knee Osteoarthritis

Background: Success of treatment for hip or knee osteoarthritis (OA) should be evaluated relative to patients' personal activity goals. Questions/Purposes: We sought to ascertain important principles for collecting such goals and developed a survey informed by those principles to facilitate better shared decision-making. Methods: From a series of 100 patient interviews inquiring about specific activity goals, we identified 6 principles for goal collection that are important to patients and physicians and could practically facilitate better shared decision-making (phase 1). Incorporating these principles, we designed a self-administered survey to measure specific pretreatment activity goals, piloting in 1 surgeon's office (phase 2). During office visits, the feasibility of achieving stated goals was discussed between the surgeon and the patient, and goal modifications were recorded. Results: The phase 2 survey was administered to 252 patients, among whom 130 were women (51.6%); 215 (85.3%), white; mean age, 58.5 years; mean body mass index, 30.2 kg/m2; and 92.9% had 1 or more goals, totaling 106 unique goals. Patient demographics were associated with having goals for walking, running, exercising, golfing, tennis, and stairs. Hip and knee patients could last perform their goal on average 21.7 and 38.6 months prior (P = .002). Patient and surgeon agreed to modify goals 19% of the time, more often among younger patients (P = .001) and for running (64% modified, P < .0001) and skiing (42%, P = .0026), but less often for walking (14%, P = .0430) and golf (0%, P = .0204). Conclusions: Patients' activity goals can be captured by a self-administered survey, collected before an office visit, and used to facilitate shared decision-making.

Klinische Diagnostik, Differenzialdiagnostik, Pathogenese- und Stadienmodell der Arthrofibrose

Die Arthrofibrose (AF) gehört zu den häufigsten Komplikationen nach Verletzungen und operativen Eingriffen an Gelenken, v. a. nach Gelenk- und Kreuzbandersatz. Alle großen Gelenke können betroffen sein, am häufigsten ist es jedoch das Kniegelenk. Es kommt zur schmerzhaften Bewegungseinschränkung durch Vermehrung von fibrotischem Gewebe innerhalb und teilweise auch außerhalb des Gelenks. Der normale Heilungsprozess ist durch mechanische und emotionale Stressoren sowie starke Schmerzreize gestört. Die AF tritt zu 90 % schon wenige Tage nach der Verletzung oder Operation auf, sodass die Qualitätsstandards nicht erreicht werden können. Durch Physiotherapie und Rehabilitation kann oft keine wesentliche Verbesserung der Funktion erreicht werden, sodass die Aktivitäten des täglichen Lebens (ADL) stark eingeschränkt sind. Klinische Diagnostik, Differenzialdiagnostik sowie ein neues Pathogenese- und Stadienmodell der primären AF mit den daraus abgeleiteten therapeutischen Prinzipien werden vorgestellt.

Validation of an MRI Technique for the 6-DOF Knee Kinematics Measurement

Background: For total knee arthroplasty (TKA), the optimal rotational position of the femoral component is felt to be critically important. The current knee joint kinematics measurement technology is unable to identify the exact rotation axis of the knee joint, the main reasons being low measurement accuracy and insufficient three-dimensional data (2D-3D image matching technology). In order to improve the effect of TKA surgery, we proposed a knee joint kinematics measurement method, based on the MRI technology, and verified its measurement accuracy. We then employed this method to identify the personalized optimal rotation axis of the knee joint for TKA patients. Purposes: The purpose of the study was 1) to propose a method for measuring knee joint kinematics and verify its accuracy and 2) to propose a method for determining the optimal rotation axis of knee joint for TKA surgery, based on accurate kinematic measurement results. Materials and Methods: The experiment was divided into two parts: in vitro and in vivo. The purpose of the in vitro experiment was to verify the measurement accuracy of our method. We fixed two aquarium stones (approximately 10 cm * 10 cm * 10 cm in size, close to the size of the distal femur and proximal tibia) firmly on the fixed and moving arms of the goniometer/vernier caliper with glue and immersed the aquarium stones in the water to capture MRI images. The MRI images were then processed with MATLAB software, and the relative motion of the two aquarium stones was measured. The measurement accuracy of our method was verified via the scale reading of the moving arm on the goniometer/vernier caliper. In vivo, 36 healthy elderly participants (22 females, 14 males) were recruited from the local community; our method was then employed to measure the relative motion of the tibia and femur and to observe the rollback and screw home motion of the medial/lateral condyle of the femur, which was identified as specific kinematic features of the knee joint. Results: In vitro, all measurements were accurate to <1 mm and <1°. In vivo, all knee measurements showed rollback motion (the rollback distance of the medial femoral condyle was 18.1 ± 3.7 mm and that of the lateral condyle was 31.1 ± 7.3 mm) and screw home motion. Conclusion: In the application scenario of knee joint kinematics measurement, our method has an accuracy of <1° of rotation angle and <1 mm of translation for all reference points, and it can be employed to identify the most stable axis of the knee joint. Significance: Using our method to accumulate data on the knee rotation axis of more subjects to establish an average rotation axis of a given population may help in knee prosthesis design and reduce the patient dissatisfaction rate. Individually measuring the patient's rotation axis before TKA surgery and adjusting the prosthesis installation in TKA may further reduce the patient dissatisfaction rate, and automatic computer measurement may be realized in the future, but it is still time-consuming for now.

What matters to patients following total knee arthroplasty? A grounded theory of adapting to a knee replacement

Background

Globally the volume of total knee arthroplasty (TKA) is on the rise, reflecting aging populations, an associated increase in treatment of osteoarthritis, and a desire for improved quality of life. There is evidence that as high as 15 to 20% of patients are not satisfied with their TKA results and efforts need to be made to improve these rates. This study set out to identify what patients consider important when reflecting on TKA satisfaction, to pave the way to identifying service transformation opportunities that will enhance patient-centred care and satisfaction with this procedure.

Methods

Twenty-seven TKA recipients were recruited in the province of British Columbia, Canada. Semi-structured interviews were conducted about participants’ experience and satisfaction with TKA, three to four years post-surgery. Grounded theory was employed to analyze participants’ stories about what was front of mind when they reflected on satisfaction with their new knee.

Results

Participants described their post-TKA knee in terms its adequacy: how it felt and worked, and how it matched their pre-surgical expectations. The central element of their stories was the process of adapting, which gave rise to their perceptions of adequacy. Adapting comprises the patient experience of physically integrating and cognitively accepting their new knee. Patterns of adapting reflect the level of the new knee’s achieved adequacy and the straightforwardness of the adapting process.

Discussion

The conceptualization of adequacy and the process of adapting allow a patient-centred understanding of what patients experience following TKA. For participants who did not readily achieve the adequacy they had anticipated, the challenges they experienced during adapting dominated their stories. Participants’ adapting stories afford key insights into how the health care system could adjust to better support TKA patients, and improve rates of satisfaction with this procedure.

Conclusions

The process of adapting lends itself to system intervention in support of enhanced post-TKA outcomes and satisfaction. These interventions could include the development of a care model including long-term clinical support for patients whose knees do not achieve desired results on schedule, and collaborating with patients to set and manage reasonable expectations about how their post-TKA knee will feel and function.

Inaccuracy of the intramedullary femoral guide: traditional instrumentation lacks precision and accuracy

PURPOSE

The purpose of the study was to utilize a large-scale biomorphometric computer tomography (CT) database to determine the desirable starting point and angle for placement of the femoral intramedullary rod in the sagittal plane.

METHODS

A CT-based modeling and analytics system (SOMA, Stryker, Mahwah, NJ) was used to evaluate 1029 entire-femur CT scans. From this, 19,464 simulations were run to test whether a 20 cm intramedullary rod, with a radius of 4 mm, would successfully pass through the femoral canal before contacting cortical bone. First, modelling included varying angles from 0-6 degrees in the sagittal plane, at 1-degree intervals. Next, the start point was adjusted with an assumed 3 degrees of induced flexion in comparison to the mechanical axis.

RESULTS

A total of 5012 simulations were able to place the femoral intramedullary rod 20 cm into the canal. The angle of the rod that created the highest proportion of successful jig placement was at a 3-degree angle of induced flexion to the orthogonal plane of the transepicondylar axis (TEA), with 33.7% successful jig placements. The starting point for the greatest proportion of successful guide placements was 48.5% along the distance between the sTEA, slightly closer to the lateral side. In the AP plane, the average distance to the ideal start point was 12.1 mm anterior to the PCL.

CONCLUSION

By examining over a thousand femoral CT scans, an angle of 3 degrees of induced flexion was identified in the sagittal plane with the highest proportion of successful placement of an intramedullary rod before cortical contact. It is important to note the high rate of failure in completely inserting the 20 mm rod.

LEVEL OF EVIDENCE

This is a prospective computer based model.

The role of digital health interventions to improve health literacy in surgical patients: a narrative review in arthroplasty

BACKGROUND

Arthroplasty is a high-volume but costly treatment option for advanced osteoarthritis. Health literacy and patient education are modifiable factors that can improve patient outcomes in arthroplasty. Digital technologies show potential as an instrument for providing patients with reliable information. This narrative review aimed to identify the current evidence for how effective digital health interventions (DHIs) are in targeting health literacy and related constructs (including knowledge, decision-making and self-efficacy) in arthroplasty.

METHODS

Six databases were searched for published studies comprising health literacy and related constructs, arthroplasty, and DHIs. The main outcome measure was health literacy. Two reviewer-authors independently screened studies according to predefined inclusion criteria and performed data extraction. Data was analysed and summarized in tabular and narrative form.

RESULTS

Two thousand seven-hundred and sixty-four titles and abstracts were screened. One hundred and sixty-seven papers underwent full-text analysis. No studies used health literacy as an outcome measure; therefore, the outcome measure was broadened to include its constructs, and the full-text analysis was repeated. Thirteen studies were included. No study following a structured design for their DHI. Eleven studies demonstrated participant improvement in constructs of health literacy, including knowledge, decision-making and self-management.

CONCLUSION

Current evidence suggests digital technology may provide new means of educating patients and improving aspects of their health literacy. More research digital technology with a structured approach, framework and standardized measures is required. Well-designed digital technology may become a useful adjunct to future patient care.

Using a patella reduced technique while balancing a TKA results in restored physiological strain in the collateral ligaments: an ex vivo kinematic analysis

INTRODUCTION

Poor soft tissue balance in total knee arthroplasty (TKA) often results in patient dissatisfaction and reduced joint longevity. Patella-in-place balancing (PIPB) is a novel technique which aims to restore native collateral ligament behavior without collateral ligament release, while restoring post-operative patellar position. This study aimed to assess the effectiveness of this novel technique through a detailed ex vivo biomechanical analysis by comparing post-TKA tibiofemoral kinematics and collateral ligament behavior to the native condition.

MATERIALS AND METHODS

Eight fresh-frozen cadaveric legs (89.2 ± 6 years) were tested on a validated dynamic knee simulator, following computed tomography imaging. Specimens were subjected to passive flexion (10-120°), squatting (35-100°), and varus/valgus laxity testing (10 Nm at 0°, 30°, 60°, 90° flexion). An optical motion capture system recorded markers affixed rigidly to the femur, tibia, and patella, while digital extensometers longitudinally affixed to the superficial medial collateral ligament (MCL) and lateral collateral ligament (LCL) collected synchronized strain data. Following native testing, a Stryker Triathlon CR TKA (Stryker, MI, USA) was performed on each specimen and the identical testing protocol was repeated. Statistical analyses were performed using a linear mixed model for functional motor tasks, while Wilcoxon signed-rank test was used for laxity tests (p < 0.05).

RESULTS

Postoperative laxity was lower than the native condition at all flexion angles while post-operative ligament strain was lowered only for MCL at 30° (p = 0.017) and 60° (p = 0.011). Postoperative femoral rollback patterns were comparable to the native condition in passive flexion but demonstrated a more pronounced medial pivot during squatting.

CONCLUSIONS

Balancing a TKA with the PIPB technique resulted in reduced joint laxity, while restoring collateral ligament strains. The technique also seemed to restore kinematics and strains, especially in passive flexion.

Robotic-assisted surgery and kinematic alignment in total knee arthroplasty (RASKAL study): a protocol of a national registry-nested, multicentre, 2×2 factorial randomised trial assessing clinical, intraoperative, functional, radiographic and survivorship outcomes

INTRODUCTION

Robot-assisted surgery (RAS) and kinematic alignment (KA) are being increasingly adopted to improve patient outcomes in total knee arthroplasty (TKA). There is uncertainty around the individual or combined effect of these concepts compared with computer-assisted surgery (CAS) and mechanical alignment (MA), respectively. This study aims to assess the effectiveness of RAS, KA or both to improve clinical outcomes, functional measures, radiographic precision and prosthetic survivorship when compared with current gold standards of surgical care.

METHODS AND ANALYSIS

A national registry-nested, multicentre, double-blinded, 2×2 factorial, randomised trial will be undertaken with 300 patients undergoing primary unilateral TKA performed by 15 surgeons. The primary outcome will be the between-group differences in postoperative change over 2 years in the mean Knee injury and Osteoarthritis Outcome Score (KOOS-12), comparing first, RAS to CAS as its control, and second, KA to MA as its control. Secondary outcomes will include other knee-specific and general health patient-reported outcome measures (PROMs), intraoperative pressure loads as a measure of soft tissue balance, 6-month postoperative functional outcomes, radiological precision using CT imaging, complications and long-term prosthetic survivorship. The contribution of each patient's unique coronal plane alignment of the knee phenotype to primary and secondary PROMs will be investigated. OMERACT-OARSI criteria and Patient Acceptable Symptom State outcome score thresholds for the KOOS-12 and Oxford Knee Score will be used in secondary analyses. Primary intention-to-treat and secondary per-protocol analyses will be performed. Statistical analysis will include a generalised linear mixed model for repeated measures for continuous KOOS-12 scores. Kaplan-Meier estimates with adjusted HRs of implant survivorship will be calculated.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Sydney Local Health District-Royal Prince Alfred Hospital (Approval X20-0494 and 2020/ETH02896 10.24/DEC20). Results will be submitted for publication in a peer-reviewed journal and presented in national, state and international meetings.

TRIAL REGISTRATION NUMBER

ACTRN12621000205831.

Impact of limb length discrepancy on functional outcome in total knee arthroplasty patients: a prospective cohort study

Background

Limb length alteration following total knee arthroplasty (TKA) has been under-reported. Few studies have shown a significant association between limb length discrepancy (LLD) and poor functional outcome. This prospective study evaluated the impact of radiographic and perceived LLD on functional outcome in TKA. The variables affecting LLD were also evaluated.

Methods

The preoperative and postoperative limb lengths of TKA patients (112 knees, 81 patients, KL grade ≥ 3) were measured in full-length digital radiographs. The Hip-Knee-Ankle (HKA) angles were also measured. The functional outcome (Western Ontario and McMaster Universities Arthritis Index) and perception about LLD were evaluated after six months.

Results

The mean preoperative radiographic LLD in the unilateral and bilateral TKA groups was 0.75 cm ± 0.60 cm and 0.58 cm ± 0.52 cm (P = 0.197), respectively. Similarly, postoperative LLD was 0.76 cm ± 0.85 cm in the unilateral group and was 0.59 cm ± 0.92 cm (P = 0.402) in the bilateral group. Only 19.7% of patients had postoperative radiographic LLD of ≥ 10 mm, and 80.2% of patients had LLD of < 10 mm. The functional outcome was significantly affected when LLD exceeded 10 mm (correlation coefficient 0.54, P < 0.001). Linear regression analysis revealed no significant effects of age, sex, height, weight, BMI, preoperative LLD and difference in deformity between the limbs on postoperative LLD. 34.5% of patients perceived LLD in the preoperative period, which decreased to 3.7% in the postoperative period. Perceived LLD did not correlate to radiographic LLD and functional outcome.

Conclusions

There is no significant difference in radiographic LLD between unilateral and bilateral TKA. The functional outcome is adversely affected by radiographic LLD of ≥ 10 mm. Age, sex, BMI, preoperative LLD and difference in deformity angle do not affect the LLD. About one-third of patients perceive LLD in the preoperative period, which improves significantly after TKA.

Levels of evidence

II.

The Effect of Posterior Cruciate Ligament Release on Kinematics and Outcomes in Primary Total Knee Arthroplasty With a Dual-Pivot Conforming Polyethylene

BACKGROUND

Ultracongruent bearings are increasingly utilized in total knee arthroplasty (TKA); however, implications of surgical technique on knee kinematics and outcomes with these bearings are not well understood. This study's purpose was to evaluate the relationship of 3-dimensional knee kinematics and patient-reported outcome measures (PROMs) in a dual-pivot congruent bearing TKA with and without posterior cruciate ligament (PCL) release.

METHODS

Forty patients undergoing TKA with an asymmetric ultracongruent bearing were prospectively enrolled for gait analysis preoperatively and 4 months postoperatively. Three-dimensional gait analysis was performed utilizing infrared motion capture. Knee kinematic data and PCL disposition were analyzed for correlations with PROMs.

RESULTS

The PCL was fully released in 52.5% (21/40) of cases. Greater maximum anteroposterior femoral translation correlated with lower Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (rho = -0.596, P = .012), greater Knee Society Score pain with level walking (rho = 0.411, P = .101), and greater Knee Society Score pain while climbing stairs (rho = 0.469, P = .058) at 4-month follow-up. The PCL-release group was associated with greater maximum femoral anteroposterior translation (9.8 vs 5.5 mm, P = .053) and greater maximum internal tibial rotation (-6.2° vs -3.0°, P = .040), supporting a more anterior-based position of the medial condyle. The PCL released group had lower median Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores (70.7 vs 76.3, P = .031) and reported that their knees "sometimes or always" feel normal less frequently (81.8% vs 92.3%, P = .576).

CONCLUSION

With this asymmetric ultracongruent bearing TKA, preservation or partial titration release of the PCL, as opposed to full PCL release, appears to minimize deleterious anterior femoral translation and internal tibial rotation, which is correlated with optimized patient-reported outcomes.

LEVEL OF EVIDENCE

II.

ISB clinical biomechanics award winner 2021: Tibio-femoral kinematics of natural versus replaced knees - A comparison using dynamic videofluoroscopy

BACKGROUND

A comparison of natural versus replaced tibio-femoral kinematics in vivo during challenging activities of daily living can help provide a detailed understanding of the mechanisms leading to unsatisfactory results and lay the foundations for personalised implant selection and surgical implantation, but also enhance further development of implant designs towards restoring physiological knee function. The aim of this study was to directly compare in vivo tibio-femoral kinematics in natural versus replaced knees throughout complete cycles of different gait activities using dynamic videofluoroscopy.

METHODS

Twenty-seven healthy and 30 total knee replacement subjects (GMK Sphere, GMK PS, GMK UC) were assessed during multiple complete gait cycles of level walking, downhill walking, and stair descent using dynamic videofluoroscopy. Following 2D/3D registration, tibio-femoral rotations, condylar antero-posterior translations, and the location of the centre of rotation were compared.

FINDINGS

The total knee replacement groups predominantly experienced reduced tibial internal/external rotation and altered medial and lateral condylar antero-posterior translations compared to natural knees. An average medial centre of rotation was found for the natural and GMK sphere groups in all three activities, whereas the GMK PS and UC groups experienced a more central to lateral centre of rotation.

INTERPRETATION

Each total knee replacement design exhibited characteristic motion patterns, with the GMK Sphere most closely replicating the medial centre of rotation found for natural knees. Despite substantial similarities between the subject groups, none of the implant geometries was able to replicate all aspects of natural tibio-femoral kinematics, indicating that different implant geometries might best address individual functional needs.

Postoperative Valgus Laxity and Medial Pivot Kinematics Are Significantly Associated With Better Clinical Outcomes

BACKGROUND

The relative impact of soft tissue balance and knee laxity on clinical outcomes after total knee arthroplasty (TKA) is not fully understood. We analyzed associations among knee laxity, kinematics, and patient-reported outcomes.

METHODS

Knee Society Scores were recorded in 67 patients before and after primary TKA for osteoarthritis with varus deformity (N = 78). Varus and valgus laxity was measured in 78 knees using stress radiographs. Knee kinematics were measured fluoroscopically during stair ascent in 16 knees.

RESULTS

On average, varus laxity decreased significantly, and valgus laxity increased significantly after TKA, although the net combined varus-valgus laxity did not change significantly. Postoperatively, the magnitude of valgus laxity correlated significantly with greater patient symptoms and satisfaction scores. Patients with medial pivot kinematics scored higher on patient satisfaction and standard activities.

CONCLUSION

We found that postoperative valgus laxity and medial pivot kinematics were significantly associated with better clinical outcomes. These results emphasize the importance of careful preoperative planning and attention to intraoperative alignment and ligament balancing.

Comparison of the clinical and patient-reported outcomes between medial stabilized and posterior stabilized total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Total knee arthroplasty (TKA) is effective in relieving pain and improving function in patients with end-stage knee osteoarthritis. Both medial stabilized total knee arthroplasty (MS-TKA) and posterior stabilized total knee arthroplasty (PS-TKA) can achieve satisfactory clinical results, but comparisons between MS-TKA and PS-TKA have yielded contradictory conclusions. This systematic review and meta-analysis were performed to investigate the differences in clinical and patient-reported outcomes (PROMs) between MS-TKA and PS-TKA.

METHODS

In December 2020, systematic searches of the following databases were undertaken: Pubmed, Embase, Cochrane Library, Clinical Trials.gov. Studies with PROMs comparing MS-TKA to PS-TKA were included. Meta-analysis was conducted for range of motion (ROM), Knee Society Score (KSS), Knee Society Functional Score (KFS), Forgotten Joint Score (FJS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Oxford Knee Score (OKS).

RESULTS

There were 17 studies included in this review, 13 studies used for quantitative analysis, and 4 studies used for qualitative synthesis. Meta-analysis concluded that the WOMAC mean difference (MD) for MS-TKA was 1.55 higher than for PS-TKA (MD = -1.55; 95 %CI = -2.45 to -0.64, P = 0.0008); however, this difference was less than the minimum clinically important difference (MCID) value of 15. Assessment using the OKS determined that the MD for PS-TKA was 0.58 higher than for MS-TKA (MD = 0.58; 95 %CI = 0.25 to 0.91, P = 0.0006); again, this MD was less than the MCID value of 5. There were no significant differences between MS-TKA and PS-TKA when assessed by ROM (P = 0.23), KSS (P = 0.13), KFS (P = 0.61), or FJS (P = 0.22).

CONCLUSION

Derived from numerous sources, utilizing a multitude of validated functional and patient-reported outcome assessment tools, there was no clinically evident advantage of MS-TKA compared to PS-TKA.

REGISTRATION

The registration number on PROSPERO is CRD42021228555.

Satisfaction and Health-Related Quality of Life Following Hip and Knee Arthroplasty Surgeries in Indian Patients: A Cross-Sectional Study

INTRODUCTION

Recently, the patient-reported outcome measures (PROMs) have been considered as the most important assessment tool for surgical outcome evaluation in arthroplasty. However, no study from the Indian subcontinent has evaluated the PROM in the total hip (THA) and knee (TKA) arthroplasties.

MATERIALS AND METHODS

This cross-sectional study evaluated the health-related quality of life (HRQoL) of 1244 North Indian patients following primary THA and TKA who had at least one-year follow-up. This study included 617 patients with 664 THA and 627 patients with 1152 TKA. The patients were asked to answer the EQ-5D-5L questionnaires and EQ-VAS in their own languages. The EQ-5D-5L values were used to derive level frequency scores (LFS) with validated Indian norms of EuroQoL.

RESULTS

Ninety percent of THA and 82% of TKA patients rated excellent HRQoL using EQ-VAS. The regression analysis revealed age, gender, etiology and brand of prosthesis had a significant impact on EQ-5D-5L following THA. However, gender and simultaneous bilateral surgery were found to be important predictors of outcome in TKA. The mean value of LFS for THA was 0.95 ± 0.12 and TKA was 0.88 + 0.24 (p < 0.001). However, There was no difference in LFS between THA and TKA when only elderly patients (> 60 years) were considered (p = 0.168).

CONCLUSION

THA patients reported better HRQoL than TKA in the Indian subcontinent. One of the factors for a better outcome in hip arthroplasty was the relatively younger age of the patients. Patients above 60 years of age reported similar levels of statisfactior in both THA and TKA.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00589-x.

Intraoperative pressure sensors improve soft-tissue balance but not clinical outcomes in total knee arthroplasty: a multicentre randomized controlled trial

AIMS

Intraoperative pressure sensors allow surgeons to quantify soft-tissue balance during total knee arthroplasty (TKA). The aim of this study was to determine whether using sensors to achieve soft-tissue balance was more effective than manual balancing in improving outcomes in TKA.

METHODS

A multicentre randomized trial compared the outcomes of sensor balancing (SB) with manual balancing (MB) in 250 patients (285 TKAs). The primary outcome measure was the mean difference in the four Knee injury and Osteoarthritis Outcome Score subscales (ΔKOOS₄) in the two groups, comparing the preoperative and two-year scores. Secondary outcomes included intraoperative balance data, additional patient-reported outcome measures (PROMs), and functional measures.

RESULTS

There was no significant difference in ΔKOOS₄ between the two groups at two years (mean difference 0.4 points (95% confidence interval (CI) -4.6 to 5.4); p = 0.869), and multiple regression found that SB was not associated with a significant ΔKOOS₄ (0.2-point increase (95% CI -5.1 to 4.6); p = 0.924). There were no significant differences between groups in other PROMs. Six-minute walking distance was significantly increased in the SB group (mean difference 29 metres; p = 0.015). Four-times as many TKAs were unbalanced in the MB group (36.8% MB vs 9.4% SB; p < 0.001). Irrespective of group assignment, no differences were found in any PROM when increasing ICPD thresholds defined balance.

CONCLUSION

Despite improved quantitative soft-tissue balance, the use of sensors intraoperatively did not differentially improve the clinical or functional outcomes two years after TKA. These results question whether a more precisely balanced TKA that is guided by sensor data, and often achieved by more balancing interventions, will ultimately have a significant effect on clinical outcomes. Cite this article: Bone Joint J 2022;104-B(5):604-612.

Patient and clinician characteristics and preferences for increasing participation in placebo surgery trials: a scoping review of attributes to inform a discrete choice experiment

Background

Orthopaedic surgeries include some of the highest volume surgical interventions globally; however, studies have shown that a significant proportion of patients report no clinically meaningful improvement in pain or function after certain procedures. As a result, there is increasing interest in conducting randomised placebo-controlled trials in orthopaedic surgery. However, these frequently fail to reach recruitment targets suggesting a need to improve trial design to encourage participation. The objective of this study was to systematically scope the available evidence on patient and clinician values and preferences which may influence the decision to participate in placebo surgery trial.

Methods

A systematic review was conducted via a literature search in the MEDLINE, Embase, PsycInfo, CINAHL, and EconLit databases as of 19 July 2021, for studies of any design (except commentaries or opinion pieces) based on two key concepts: patient and clinician characteristics, values and preferences, and placebo surgery trials.

Results

Of 3424 initial articles, we retained 18 eligible studies. Characteristics, preferences, values, and attitudes of patients (including levels of pain/function, risk/benefit perception, and altruism) and of clinicians (including concerns regarding patient deception associated with placebo, and experience/training in research) influenced their decisions to participate in placebo-controlled trials. Furthermore, some aspects of trial design, including randomisation procedures, availability of the procedure outside of the trial, and the information and consent procedures used, also influenced decisions to participate.

Conclusion

Participant recruitment is a significant challenge in placebo surgery trials, and individual decisions to participate appear to be sensitive to preferences around treatment. Understanding and quantifying the role patient and clinician preferences may play in surgical trials may contribute to the optimisation of the design and implementation of clinical trials in surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06277-x.

Patient and Surgeon Risk-Taking Regarding Total Joint Arthroplasty

BACKGROUND

Decisions regarding care for osteoarthritis involve physicians helping patients understand likely benefits and harms of treatment. Little work has directly compared patient and surgeon risk-taking attitudes, which may help inform strategies for shared decision-making and improve patient satisfaction.

METHODS

We surveyed patients contemplating total joint arthroplasty visiting a high-volume specialty hospital regarding general questions about risk-taking, as well as willingness to undergo surgery under hypothetical likelihoods of moderate improvement and complications. We compared responses from surgeons answering similar questions about willingness to recommend surgery.

RESULTS

Altogether 82% (162/197) of patients responded, as did 65% (30/46) of joint replacement surgeons. Mean age among patients was 66.4 years; 58% were female. Surgeons averaged 399 surgeries in 2019. Responses were similar between groups for general, health, career, financial, and sports/leisure risk-taking (P > .20); surgeons were marginally more risk-taking in driving (P = .05). For willingness to have or recommend surgery, as the chance of benefit decreased, or the chance of harm increased, the percentage willing to have or recommend surgery decreased. Between a 70% and 95% chance of moderate improvement (for a 2% complication risk), as well as between a 90% and 95% chance of moderate improvement (for 4% and 6% complication risks), the percentage willing to have or recommend surgery was indistinguishable between patients and surgeons. However, for lower likelihoods of improvement, a higher percentage of patients were willing to undergo surgery than surgeons recommended. Patients were also more often indifferent between complication risks.

CONCLUSION

Although patients and surgeons were often willing to have or recommend joint replacement surgery at similar rates, they diverged for lower-benefit higher-harm scenarios.

Tibiofemoral Contact Forces Influence Intraoperative Kinematic Pivot Pattern Dependent on Posterior Cruciate Ligament Resection in Primary Total Knee Arthroplasty

Background:

Optimizing knee kinematics has the potential to increase patient satisfaction with total knee arthroplasty (TKA); however the ability to enact a particular kinematic pattern is variable and inconsistent. The purpose of this study was to determine whether intraoperative contact forces were predictive and can potentially drive a particular kinematic pivot pattern.

Methods:

All TKAs used sensor-embedded tibial trials to intraoperatively measure medial and lateral compartment forces, and the associated condylar contact points were used to calculate kinematic pivot patterns between preceding flexion angles.

Results:

After exclusions, 157 TKAs were analyzed. For posterior cruciate ligament–intact TKAs, no predictors of lateral pivot were identified in early flexion; however, increased medial compartment force and increased lateral compartment force were predictors of medial and lateral pivots for mid and late flexion, respectively (P ≤ 0.037). For posterior cruciate ligament–resected TKAs, increased lateral compartment force was a predictor of lateral pivot in early and midflexion (P ≤ 0.031) but not late flexion.

Conclusion:

The tibiofemoral compartment with greater contact force exhibited less anteroposterior translation at certain flexion ranges and correlated with kinematic pivot patterns. This information may benefit surgeons who are attempting to facilitate a particular kinematic pattern. Further research is recommended to confirm that intraoperative kinematics correlate with weight-bearing postoperative kinematics and clinical outcomes.

A Comparison of Clinical Outcomes and Implant Preference of Patients with Bilateral TKA: One Knee with a Patient-Specific and One Knee with an Off-the-Shelf Implant

BACKGROUND

The purpose of this retrospective study was to compare clinical outcome results, perceived function, and overall preference among patients who had undergone staged bilateral total knee arthroplasty (TKA) with a cruciate-retaining, customized implant (customized TKA, or C-TKA) in 1 knee and an off-the-shelf (OTS) implant in the contralateral knee.

METHODS

Forty-seven patients (94 knees) from a single study center who underwent C-TKA in 1 knee and had previously undergone TKA with an OTS implant in the contralateral knee were included in this study. As the primary outcome measures, the Knee injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS, JR) and the Forgotten Joint Score (FJS) were self-administered by the study subjects at a single follow-up time point. Additionally, a follow-up questionnaire to compare patients' perceived joint stability, knee mobility, perceived feeling of the replaced joint, pain levels, and overall preference between their knees was administered.

RESULTS

The average follow-up was 2.3 years (range, 0.7 to 3.8 years) for C-TKA and 6.7 years (range, 1.6 to 11.1 years) for the OTS TKA. Significantly higher KOOS, JR (82 versus 77; p = 0.03) and FJS (68 versus 58; p = 0.04) results were found with C-TKA. The evaluation of the follow-up questionnaire showed that more patients reported having "a little" or "a lot" less pain (49% versus 15%), better perceived mobility (45% versus 12%) and stability (36% versus 13%), and a more "normal" feeling of their knee (60% versus 10%) with the C-TKA implant compared with their OTS counterpart. When patients were asked to directly compare their knees, we found that 72.3% of the patients preferred the knee that received C-TKA over the contralateral OTS knee replacement, with 21.3% seeing no difference and 6.4% preferring the OTS knee replacement.

CONCLUSIONS

We believe that this is the first study to examine patient-reported outcomes of customized and OTS TKA implant designs in the same patient. We conclude that patients in this study cohort who underwent staged bilateral TKA with a C-TKA implant in 1 knee and an OTS prosthesis in the other knee reported better for their patient-specific knee replacement, with higher FJS and KOOS, JR values, and overall, preferred the C-TKA knee more often compared with the OTS knee replacement.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Shared Decision-Making Is Associated with Better Outcomes in Patients with Knee But Not Hip Osteoarthritis: The DECIDE-OA Randomized Study

BACKGROUND

Current guidelines recommend shared surgical decision-making, yet it is unclear whether shared decision-making improves health outcomes in patients who are considering knee and hip replacement. The purpose of the present study was to examine whether patients who made high-quality, informed, patient-centered (IPC) decisions had better health outcomes, higher satisfaction, and less decision regret compared with those who made lower-quality decisions.

METHODS

A multisite, randomized study of 2 decision aids for patients with hip and knee osteoarthritis was utilized to collect data on decision-making and health outcomes at 2 time points: shortly after the initial surgical evaluation and about 6 months after treatment. We calculated the percentage of patients who made an IPC decision and examined the a priori hypotheses that IPC decisions would be associated with better health outcomes, satisfaction, and less regret at 6 months. Linear and logistic regression models were utilized to examine the relationships.

RESULTS

The analytic sample included 854 patients with a mean age of 65 years (standard deviation, 9 years), of whom 58% were female, 93% were White non-Hispanic, 67% had knee (compared with hip) osteoarthritis, and 62% underwent operative treatment within 6 months of the initial evaluation. The majority of patients (68%) made IPC decisions. The IPC group had significantly larger gains in quality of life (mean difference in EuroQol-5 Dimension, 0.04; 95% confidence interval [CI], 0.02 to 0.07; p < 0.001) compared with the non-IPC group. For knee patients, the IPC group also had significantly better Knee injury and Osteoarthritis Outcome Scores (mean difference, 4.9; 95% CI, 1.5 to 8.3; p = 0.004), higher satisfaction (adjusted odds ratio [aOR], 1.7; 95% CI, 1.2 to 2.3; p = 0.003), much better pain relief (aOR, 2.1; 95% CI, 1.3 to 3.5; p = 0.002), and were more likely to have no decision regret (aOR, 2.3; 95% CI, 1.3 to 4.1; p = 0.003). For hip patients, IPC decisions were not associated with better Harris hip scores or satisfaction and were associated with more regret.

CONCLUSIONS

Higher-quality decisions predicted small improvements in health outcomes, as well as greater satisfaction and less regret for patients with knee osteoarthritis, but not for patients with hip osteoarthritis.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Can tibio-femoral kinematic and kinetic parameters reveal poor functionality and underlying deficits after total knee replacement? A systematic review

BACKGROUND

Extensive efforts have been made to understand joint kinematics and kinetics in total knee arthroplasty (TKA) in subjects with satisfactory outcomes during daily functional activities and clinical tests, but it remains unclear whether such movement characteristics hold the potential to indicate the underlying aetiology of unsatisfactory or bad TKA outcomes.

PURPOSE

To investigate which kinematic and kinetic parameters assessed during passive clinical tests and functional activities of daily living are associated with poor functionality and underlying deficits after total knee replacement.

METHODS

We focused on studies characterizing the kinematic or kinetic parameters of the knee joint that are associated with poor clinical outcome after TKA. Seventeen articles were included for the review, and kinematic and kinetic data from 719 patients with minimal follow up of 6 months were extracted and analyzed.

RESULTS

Passive posterior translation at 90°flexionexhibited good potential for differentiating stable and unstable TKAs. Anterior-posterior (A-P) translation of the medial condyle at 0-30° and 30-60° flexion, A-P translation of the lateral condyle at 60-90°during closed chain exercises, as well asknee extension moment during stair ascent and descent, knee abduction moment during stair descent, knee internal rotation moment and plantar flexion moment during walking, 2ndpeak ground reaction force during stair ascent and walkingshowed the greatest promise as functional biomarkers for a dissatisfied/poor outcome knee after TKA.

CONCLUSION

In this study, we systematically reviewed the state-of-the-art knowledge of kinematics and kinetics associated with functional deficits, and found 11 biomechanical parameters that showed promise for supportingdecision making in TKA.

Intra-Articular Corticosteroid Injection After Total Knee Replacement: Is it Safe?

Recalcitrant pain after total knee replacement (TKR) is sometimes treated with intra-articular steroid injections (IASI), with few studies reporting on the risk of subsequent periprosthetic joint infection (PJI). This is a systematic review to evaluate the incidence and risk of PJI after IASI into a total knee replacement.

We searched online databases using the keywords "total knee replacement," "total knee arthroplasty," "steroids" and "intra-articular injection." A total of 7386 articles (PubMed - 91, Embase - 70, Web of Science - 57, CINAHL - 8, and Google Scholar - 7160) were retrieved on the initial search. After applying exclusion criteria, four articles were included in this review for evaluation and statistical analysis. There were no level one or two studies.

The incidence of infection after IASI at 12 months was 138/6499 or 2.1%, while the incidence of infection rate among controls at 12 months was 158/11256 or 1.4%. A chi-square test showed that the difference in infection rate was significant (p = 0.0002424). A caveat is that simple statistical test results are virtually guaranteed to be statistically significant with large sample size.

IASI into a TKR is not a benign procedure and that may be associated with a significantly increased risk of subsequent periprosthetic joint infection. We, therefore, recommend against IASI into a TKR until better studies can be performed to determine their safety and efficacy.

Use of a Tourniquet and Spinal Anesthesia Increases Satisfactory Outcomes After Total Knee Arthroplasty: A Randomized Study

BACKGROUND

Total knee arthroplasty (TKA) is usually performed successfully with or without a tourniquet and under spinal anesthesia (SA) or general anesthesia (GA). However, 10% to 34% of patients experience dissatisfaction and pain after TKA. We aimed to compare the effects of tourniquet use and SA or GA on TKA outcomes.

METHODS

We randomly assigned 404 patients to 4 study groups: SA without a tourniquet (NT/SA), SA with a tourniquet (T/SA), GA without a tourniquet (NT/GA), and GA with a tourniquet (T/GA). The primary outcome was the change in the Oxford Knee Score (OKS) at 1 year postoperatively. Secondary outcomes included a satisfactory TKA outcome assessed using the OKS minimal important change (MIC) and OKS patient acceptable symptom state (PASS), adverse events, and quality of life using the 15-dimensional health-related quality of life tool.

RESULTS

At 1 year, the OKS was obtained for 381 patients. In the 2-group comparisons, the tourniquet did not affect the OKS improvement. The SA group had more substantial improvement in the OKS than the GA group (16.21 compared with 14.08 a mean difference of 2.13; 95% confidence interval [CI], 0.55 to 3.71; p = 0.008). In the 4-group comparisons, the T/SA group had more substantial improvements in the OKS than the NT/GA group (16.87 compared with 13.65, a mean difference of 3.2; 95% CI, 0.28 to 6.17; p = 0.026). The SA group reached the OKS MIC more frequently than the GA group (91.7% compared with 81.7%; odds ratio [OR] = 2.49 [95% CI, 1.32 to 4.69]; p = 0.005). The SA group also reached the OKS PASS more frequently than the GA group (86.0% compared with 75.7%; OR = 2.00 [95% CI, 1.18 to 3.39]; p = 0.010). The T/SA group had significantly more patients reaching the OKS MIC than the NT/GA group (95.7% compared with 79.6%; p = 0.005) and more patients reaching the OKS PASS than the NT/GA group (92.6% compared with 74.5%; p = 0.004). No differences were seen with respect to adverse events in any comparisons.

CONCLUSIONS

The tourniquet had no detrimental effects on the outcomes of TKA. SA had a positive effect on the OKS. The use of SA combined with a tourniquet resulted in the best improvement in OKS and the highest proportion of satisfactory outcomes with TKA.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.