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

Suture debris from high-tensile sutures contributes significantly to particle-induced tissue response in shoulder arthroplasty

HYPOTHESIS AND BACKGROUND

Polyethylene (PE) wear debris has long been known to be important for the development of osteolysis and aseptic loosening in total joint replacements. Evaluation of shoulder hemiarthroplasty (HA) specimens provided a unique opportunity to study the histopathologic response when a PE-bearing surface was absent. We hypothesized that HAs would exhibit no significant inflammatory periprosthetic tissue response due to the absence of significant numbers of wear particles from the articulation.

METHODS

We analyzed 13 shoulder HAs. The explants were examined for damage to the bearing surface and taper damage using a stereomicroscope. The periprosthetic tissues were examined histologically for wear debris and cellular biological response. Fourier Transform Infrared spectroscopy imaging and scanning electron microscopy with energy dispersive x-ray spectroscopy were used to characterize debris, if present, within tissue samples.

RESULTS

The average patient age at the time of implantation was 57.2 ± 7.3, and the average time in situ was 34.1 ± 29.4 months. The metal-bearing surface damage was primarily mild, with an average score of 1.5 ± 0.7. The same was true for taper damage on both humeral stem and head tapers, with average scores of 1.7 ± 0.5 and 1.7 ± 0.9, respectively. The histopathological analysis revealed the considerable presence of metal debris in 11 (91.7%), cement debris in 4 (33.3%), and suture debris in 11 (83.3%) cases. Scanning electron microscopy/energy dispersive x-ray spectroscopy revealed titanium alloy debris to be the most dominant type of metal particle present, while Fourier Transform Infrared spectroscopy imaging scans suggested polyester to be the most commonly occurring type of suture debris. Particles were mostly found within and around macrophages. The mean macrophage score was 3.1 ± 0.8, and the mean foreign-body giant cell score was 2.3 ± 1.1. There was, on average, no significant lymphocyte or neutrophil presence, except for a single septic case.

DISCUSSION AND CONCLUSION

This surgically retrieved shoulder HA cohort exhibited a considerable macrophage and foreign-body giant cell response within the periprosthetic environment. Interestingly, given the low amount of damage to metallic surfaces and the absence of a PE bearing, the tissue response does not appear to be driven by wear particles from the metal-bearing surface or taper junctions but rather from suture and, to a much lesser degree, cement and metal debris. Overall, these findings highlight the potential impact that high-tensile suture material, frequently used in high quantities around shoulder arthroplasty, may have on the periprosthetic environment and identify these materials as a potential driver of osteolysis.

Primary Hip Arthroscopy Is Associated With Earlier Achievement of Substantial Clinical Benefit Compared With Revision Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

To compare time to achievement of clinically significant outcomes (CSOs) between patients undergoing primary and revision hip arthroscopy (HA) for femoroacetabular impingement syndrome.

METHODS

Patients undergoing primary and revision HA for femoroacetabular impingement syndrome with complete 6-month, 1-year, and 2-year Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Sport Subscale (HOS-SSS) were identified. Revision patients were propensity matched 1:4 to primary patients with HA, controlling for age, sex, and body mass index (BMI). Time to achievement of minimal clinically important difference and substantial clinical benefit (SCB) were compared alongside cumulative CSO achievement at 6, 12, and 24 months. Hazard ratios (HRs) for predictors of earlier CSO achievement were identified with multivariate Cox regressions.

RESULTS

Fifty patients with revision HA were propensity-matched to 200 patients with primary HA of similar age, sex, and BMI. Patients with primary HA demonstrated a greater prevalence of regular preoperative physical activity (87% vs 59%, P < .001). Patients with primary HA showed significantly greater SCB achievement for HOS-ADL at 6, 12, and 24 months (P < .001) and significantly greater SCB achievement for HOS-SSS at 12 and 24 months (P ≤ .001) compared with patients with revision HA. Patients with primary HA achieved SCB for HOS-ADL (P < .001) and HOS-SSS (P = .015) quicker than patients with revision HA. Predictors of earlier CSO achievement included preoperative PRO score (HR 0.98-1.02, P ≤ 0.007), lower BMI (HR 0.97, P = .038), presence of physical activity (HR 1.51, P = .038), and absence of revision status (HR 0.52-0.56, P ≤ .019).

CONCLUSIONS

Patients with primary HA showed a quicker time to SCB achievement for HOS-ADL and HOS-SSS compared with patients with revision HA. Preoperative PRO score, lower BMI, regular physical activity, and primary HA status predicted earlier CSO achievement.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Hip Gluteus Repair Yields Satisfactory Clinically Significant Outcome Achievement By 1 Year in a Majority of Patients: Those With Partial-Thickness Tears and Preoperative Hip Abduction Weakness Show Delayed Recovery

PURPOSE

To define the time to achievement of clinically significant outcomes (CSOs) after primary gluteus medius and/or minimus (GM) repair and to identify factors associated with delayed CSO achievement.

METHODS

Patients who underwent primary GM repair between January 2012 and June 2021 with complete preoperative, 6-month, 1-year, and 2-year Hip Outcome Score-Activities of Daily Living (HOS-ADL) were retrospectively identified. Cohort-specific minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were calculated. The time to achievement of MCID and PASS was analyzed using Kaplan-Meier survival analysis. Median time to MCID and PASS achievement was recorded. Multivariate stepwise Cox regressions were used to identify factors associated with delayed CSO achievement.

RESULTS

Fifty GM repairs were identified (age 59.4 ± 9.7 years, body mass index 27.9 ± 6.2, 94% female). Tears were grade 1 in 39 cases, grade 2 in 7 cases, and grade 3 in 4 cases. Endoscopic repair was performed in 35 cases, and open repair was performed in 15 cases. Labral debridement and repair were each performed in 15 cases. Median time to CSO achievement was 5.7 months for MCID and 11.0 months for PASS. The 2-year cumulative probability of MCID and PASS achievement was 92.7% and 66.7%, respectively. Preoperative hip abduction weakness on physical examination was associated with delayed achievement of MCID (hazard ratio 2.27, confidence interval 1.067-7.41, P = .039) and PASS (hazard ratio 3.89, confidence interval 1.341-11.283, P = .012).

CONCLUSIONS

This study demonstrated that in patients undergoing repair of primarily grade 1 GM tears, most achieved MCID by 6 months, and more than one half achieved PASS by 12 months. Preoperative hip abduction weakness on physical examination was associated with delayed CSO achievement.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Stratification of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex

BACKGROUND

Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis.

METHODS

A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified.

RESULTS

A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex.

CONCLUSION

MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

The Association of Preoperative Hip Pain Duration With Delayed Achievement of Clinically Significant Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

BACKGROUND

Patients with hip pain ≥2 years before hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) have been shown to achieve inferior short-term and midterm outcomes compared with patients with a shorter pain duration, although there is limited literature that has evaluated the time to achieve clinically significant outcomes (CSOs) in this population.

PURPOSE

To compare the time to achieve CSOs after hip arthroscopic surgery for FAIS in patients with and without prolonged hip pain and to identify independent predictors of the delayed achievement of CSOs.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent primary hip arthroscopic surgery for FAIS between January 2012 and July 2019 with 6-month, 1-year, and 2-year Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Hip Outcome Score-Sports Subscale (HOS-SS) scores were identified. Patients with prolonged hip pain (preoperative duration ≥2 years) were propensity score matched to a control group (preoperative duration <2 years), controlling for age, sex, and body mass index (BMI). The times to achieve the minimal clinically important difference and Patient Acceptable Symptom State were compared between groups using Kaplan-Meier survival analysis. Multivariate Cox regression considering age, sex, BMI, pain duration, activity level, and chondral status was used to identify independent predictors of the delayed achievement of CSOs.

RESULTS

A total of 179 patients with prolonged hip pain were matched to 179 control patients (mean pain duration, 60.5 ± 51.2 vs 9.7 ± 5.1 months, respectively; P < .001) of a similar age, sex, and BMI (P≥ .488) with similar baseline HOS-ADL and HOS-SS scores (P≥ .971). The prolonged hip pain group showed delayed achievement of the minimal clinically important difference and Patient Acceptable Symptom State for both the HOS-ADL and HOS-SS on Kaplan-Meier analysis (P≤ .020). On multivariate Cox regression, hip pain duration ≥2 years was shown to be an independent predictor of the delayed achievement of CSOs, with hazard ratios ranging from 1.32 to 1.65 (P≤ .029). Additional independent predictors of the delayed achievement of CSOs included increasing age, increasing BMI, female sex, self-endorsed weekly participation in physical activity, and high-grade chondral defects (hazard ratio range, 1.01-4.89; P≤ .045).

CONCLUSION

Findings from this study demonstrate that preoperative hip pain duration ≥2 years was an independent predictor of the delayed achievement of CSOs after primary hip arthroscopic surgery for FAIS.

A machine learning analysis of patient and imaging factors associated with achieving clinically substantial outcome improvements following total shoulder arthroplasty: Implications for selecting anatomic or reverse prostheses

Background

Indications for reverse total shoulder arthroplasty(rTSA) continue to expand making it challenging to predict whether patients will benefit more from anatomic TSA(aTSA) or rTSA. The purpose of this study was to determine which factors differ between aTSA and rTSA patients that achieve meaningful outcomes and may influence surgical indication.

Methods

Random Forest dimensionality reduction was applied to reduce 23 features into a model optimizing substantial clinical benefit (SCB) prediction of the American Shoulder and Elbow Surgeon score using 1117 consecutive patients with 2-year follow up. Features were compared between aTSA patients stratified by SCB achievement and subsequently with rTSA SCB achievers.

Results

Eight combined features optimized prediction (accuracy = 87.1%, kappa = 0.73): (1) age, (2) body mass index (BMI), (3) sex, (4) history of rheumatic disease, (5) humeral head subluxation (HH) on computed tomography (CT), (6) HH-acromion distance on X-ray, (7) glenoid retroversion on CT, and (8) Walch classification on CT. A higher proportion of males (65.6% vs. 54.9%, p = 0.022), Walch B-C glenoid morphologies (49.5% vs. 37.9%, p < 0.001), and greater BMI (30.1 vs. 26.5 kg/m2, p = 0.038) were observed in aTSA nonachievers compared with aTSA achievers, while aTSA nonachievers were statistically similar to rTSA achievers.

Discussion

Patients with glenohumeral osteoarthritis and intact rotator cuffs that have a BMI > 30 kg/m2 and exhibit Walch B-C glenoids may be less likely to achieve the SCB following aTSA and should be considered for rTSA.

Clinically significant outcome thresholds and rates of achievement by shoulder arthroplasty type and preoperative diagnosis

BACKGROUND

Clinically significant outcome (CSO) benchmarks have been previously established for shoulder arthroplasty by assimilating preoperative diagnoses and arthroplasty types. The purpose of this study was to establish unique CSO thresholds and compare the time-to-achievement of these for reverse shoulder arthroplasty (RSA) for osteoarthritis (GHOA), RSA for rotator cuff arthropathy (RCA), and total shoulder arthroplasty (TSA) for GHOA.

MATERIALS AND METHODS

Consecutive patients who underwent elective RSA for GHOA, TSA for GHOA, or RSA for RCA between February 2015 and May 2020, with 2-year minimum follow-up, were retrospectively identified from a prospectively maintained single surgeon registry. The American Shoulder and Elbow Surgeons (ASES) score was administered preoperatively and postoperatively at 2-week, 6-week, 3-month, 6-month, 1-year, and 2-year timepoints. Satisfaction and subjective overall improvement anchor questionnaires were administered at the time of final follow-up. Distribution-based methods were used to calculate the Minimal Clinically Important Difference (MCID), and anchor-based methods were used to calculate the Substantial Clinical Benefit (SCB) and the Patient Acceptable Symptom State (PASS) for each patient group. Median time to achievement, individual incidence of achievement at each time point, and cumulative incidence of achievement calculated using Kaplan-Meier survival curve analysis with interval censoring were compared between groups for each CSO. Cox-regression analyses were also performed to determine which patient factors were significantly associated with early or delayed achievement of CSOs.

RESULTS

There were 471 patients eligible for study analysis: 276 RSA for GHOA, 107 TSA for GHOA, and 88 RSA for RCA. The calculated MCID, SCB, and PASS scores differed for each group. There were no significant differences in median time to achievement of any CSO between groups. Log-rank testing revealed that cumulative achievements significantly differed between groups for MCID (P = .014) but not for SCB (P = .053) or PASS (P = .620). On cox regression analysis, TSA patients had earlier achievement of SCB, whereas TSA and RSA for GHOA patients had earlier achievement of MCID. At 2-years, a significantly higher percentage of RSA for GHOA patients achieved MCID and SCB compared to RSA for RCA (MCID:100%, 95.5%, P = .003, SCB:94.6%, 86.4%, P = .036).

CONCLUSION

Calculated CSO thresholds differ according to preoperative diagnosis and shoulder arthroplasty type. Patients undergoing TSA and RSA for GHOA achieve CSOs earlier than RSA for RCA patients, and a significantly higher percentage of RSA for GHOA patients achieve CSOs by 2 years compared to RSA for RCA patients.

Patients 75 years or older with primary glenohumeral arthritis and an intact rotator cuff show similar clinical improvement after reverse or anatomic total shoulder arthroplasty

BACKGROUND

The optimal management of primary glenohumeral arthritis (GHOA) in the elderly is an ongoing topic of debate. The purpose of this study was to compare functional outcomes and complications in patients aged 75 years or older treated with anatomic total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (RSA) for primary GHOA with an intact rotator cuff.

METHODS

A retrospective study was performed on a prospectively maintained database which was queried for patients 75 years of age or older who underwent TSA or RSA for primary GHOA with an intact rotator cuff at a single institution between 2012 and 2021 with minimum 2-year follow-up. Patient-reported outcomes (PROs), including Visual Analog Scale for pain, American Shoulder and Elbow Surgeons, and Subjective Shoulder Value, as well as active range of motion including forward flexion, external rotation, internal rotation, were collected preoperatively and postoperatively. Complications, reoperations, and satisfaction were also recorded. The percentage of patients achieving clinically significant improvement was evaluated with the minimally clinical important difference, substantial clinical benefit, and patient acceptable symptomatic state for each PRO.

RESULTS

One-hundred and 4 patients were available for analysis, including 67 TSA patients and 37 RSAs with a mean follow-up of 39.4 months. Preoperative baseline characteristics, PROs, and range of motion were similar between groups. RSA was more commonly performed for eccentric glenoid wear (Walch B2/B3, 62% vs. 22%; P < .001). While clinical outcomes improved comparably in both groups, the TSA cohort showed significantly greater improvement in external rotation (36° vs. 26°; P = .013). Both cohorts had low revision (3% for TSA vs. 0% for RSA) and complication (7% for TSA vs. 5% for RSA; P = .677) rates. Satisfaction was similar in both groups (93% for TSA vs. 92% for RSA; P = .900). Clinically significant improvement was comparable between groups based on the American Shoulder and Elbow Surgeons score (minimally clinical important difference, 93% for TSA vs. 100% for RSA; substantial clinical benefit, 82% vs. 95%; patient acceptable symptomatic state, 67% vs. 78%; P > .05).

CONCLUSION

In this retrospective small sample size comparison study, TSA and RSA provide similar short-term clinical outcomes for patients 75 years and older with primary GHOA and an intact rotator cuff. Complication and revision rates are comparably low at short-term follow-up. Our data suggests that advanced age alone should not be used as a decision-making tool for TSA vs. RSA in the setting of primary GHOA with an intact rotator cuff.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Quantifying success after reverse total shoulder arthroplasty: the substantial clinically important percentage of maximal possible improvement

BACKGROUND

Changes in preoperative to postoperative outcome scores are often used to quantify success after reverse total shoulder arthroplasty (rTSA). However, ceiling effects associated with many outcome scores limit the ability to differentiate success among high-functioning patients. The percentage of maximal possible improvement (%MPI) was introduced to simplify and better stratify patient success. The primary purpose of this study was to define the %MPI thresholds associated with substantial clinical improvement following primary rTSA and compare the rates of success as defined by those achieving the substantial clinical benefit (SCB) compared to the 30% MPI for different outcome scores.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary rTSAs performed using a single implant system with a minimum 2-year follow-up were reviewed. Preoperative and postoperative outcome scores were evaluated for all patients to calculate improvement. Six outcome scores were assessed: the Simple Shoulder Test (SST), Constant, American Shoulder and Elbow Surgeons (ASES), University of California Los Angeles (UCLA), Shoulder Pain and Disability Index (SPADI), and Shoulder Arthroplasty Smart (SAS) scores. The proportion of patients achieving the SCB and 30% MPI was determined for each outcome score. Thresholds for the substantial clinically important %MPI (SCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

Of total, 2573 shoulders with a mean follow-up of 47 months were included. Outcome scores with known ceiling effects (SST, ASES, UCLA, SPADI) had higher rates of patients achieving the 30% MPI compared to scores without ceiling effects (Constant, SAS). However, scores without ceiling effects had higher rates of patients achieving the SCB. The SCI-%MPI differed among outcome scores, and mean values were 47% for the SST, 35% for the Constant score, 50% for the ASES score, 52% for the UCLA score, 47% for the SPADI score, and 45% for the SAS score. The SCI-%MPI increased in patients older than 60 years (P < .001) except for the SAS and Constant scores. SCI-%MPI was greater in females for all scores assessed except the Constant and SPADI scores (P < .001 for all). The higher SCI-%MPI thresholds in these populations mean that these patients required a greater fraction of the MPI to have substantial improvement.

CONCLUSION

The %MPI judged relative to patient-reported substantial clinical improvement offers an alternative method to quickly assess improvements across patient outcome scores. Given considerable variation in the %MPI corresponding to substantial clinical improvement, we recommend utilizing score-specific estimates of the SCI-%MPI to gauge success when evaluating patients undergoing primary rTSA.

Patients with poor early clinical outcomes after anatomic total shoulder arthroplasty have sustained poor performance at 2 years from surgery

PURPOSE

We sought to define the risk of persistent shoulder dysfunction after anatomic total shoulder arthroplasty (aTSA) beyond the early postoperative period and identify risk factors for persistent poor performance.

METHODS

We retrospectively identified 144 primary aTSAs performed for primary osteoarthritis with early poor performance and 2-year minimum follow-up. Early poor performance was defined as a postoperative ASES score below the 20th percentile at 3- or 6-months (62 and 72 points, respectively). Persistent poor performance at 2 years was defined as failing to achieve the patient acceptable symptomatic state (PASS) [ASES = 81.7 points].

RESULTS

At 2-year follow-up, 51% (n = 74) of patients with early poor performance at either 3- or 6-month follow-up had persistent poor performance. There was no difference in the rate of persistent poor performance if patients were poor performers at the 3-, 6-month follow-up, or both (50% vs. 49% vs. 56%, P = .795). Of aTSAs achieving the PASS at 2-year follow-up, a greater proportion exceeded the minimal clinically important differences (MCID) [Forward elevation, external rotation, and all outcome scores] and substantial clinical benefit (SCB) [external rotation and all outcome scores] compared to persistent poor performers. However, over half of persistent poor performers still exceeded the MCID for all outcome measures (56-85%). Independent predictors of persistent poor performance were hypertension (2.61 [1.01-6.72], P = .044) and diabetes (5.14 [1.00-26.4], P = .039).

CONCLUSION

Over half of aTSAs with an ASES score < 20th percentile at early follow-up had continued poor shoulder function at 2-years postoperatively. Persistent poor performance was best projected by preoperative hypertension and diabetes.

LEVEL OF EVIDENCE

Level III; Retrospective Cohort Comparison using Large Database; Treatment Study.

Quantifying success after anatomic total shoulder arthroplasty: the minimal clinically important percentage of maximal possible improvement

INTRODUCTION

Changes in pre- to postoperative outcome scores are often used to quantify success after anatomic total shoulder arthroplasty (aTSA). However, ceiling effects associated with many outcome scores limit the ability to differentiate success among high-functioning patients. The percentage maximal possible improvement (%MPI) was introduced to better stratify patient success; however, it is unclear if the 30% threshold first proposed correlates with perceived patient success across all outcome scores. The purpose of this study was to compare the proportion of patients that achieved the minimal clinically important difference (MCID) and %MPI for different outcome scores and to define the %MPI thresholds associated with patient satisfaction following primary aTSA.

METHODS

A retrospective review was performed of an international shoulder arthroplasty database between 2003 and 2020. All primary aTSAs performed using a single implant system with minimum 2-year follow-up were reviewed. Pre- and postoperative outcome scores were evaluated for all patients to calculate improvement. The proportion of patients achieving the MCID and 30% MPI were determined for each outcome score. Thresholds for the minimal clinically important %MPI (MCI-%MPI) were calculated using an anchor-based method for each outcome score and stratified by age and sex.

RESULTS

1593 shoulders with a mean follow-up of 59.3 months were included. Outcome scores with known ceiling effects (Simple Shoulder Test [SST], American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], University of California-Los Angeles shoulder score [UCLA]) had higher rates of patients achieving the 30% MPI but not the previously reported MCID. Inversely, outcome scores without significant ceiling effects (Constant and Shoulder Arthroplasty Smart [SAS] scores) had higher rates of patients achieving the MCID but not the 30% MPI. The MCI-%MPI differed among outcome scores, and mean values were as follows: 33% for the SST, 24% for the Constant score, 32% for the ASES score, 38% for the UCLA score, 30% for the Shoulder Pain and Disability Index score, and 33% for the SAS score. The MCI-%MPI increased with greater age (P < .003) and females had thresholds greater than or equal to males for all scores assessed, meaning that patients with higher thresholds required a greater fraction of the possible improvement for a given score to be satisfied.

CONCLUSION

The %MPI offers a simple method to quickly assess improvements across patient outcome scores. However, the %MPI that represents patient improvement after surgery is not uniformly the previously established 30% threshold. Surgeons should use score-specific estimates of the MCI-%MPI to gauge success when evaluating patients undergoing primary aTSA.

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

Background

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

Purpose

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

Study Design

Case-control study; Level of evidence, 3.

Methods

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

Results

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

Conclusion

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

Substantial clinical benefit values demonstrate a high degree of variability when stratified by time and geographic region

Background

A Substantial Clinical Benefit (SCB) value is the amount of change in a patient-reported outcome measure required for a patient to feel they significantly improved from an intervention. Previously published SCB values are often cited by researchers when publishing outcomes data. Where these SCB values are set can have a large impact on the conclusions drawn from a study citing them. As such, the goal of this study was to determine the generalizability of SCB values for a procedure when stratified by time from surgery and geographic region.

Methods

A nationwide outcomes database was utilized to obtain preoperative, one-year, and two-year postoperative outcome measurements for patients who underwent anatomic total shoulder arthroplasty (TSA) or reverse TSA. The data were divided into three geographic regions: the South, the Midwest, and the West. An East region was not included due to its limited number of patients. SCB values were calculated for four outcomes measures: Single Assessment Numeric Evaluation score, American Shoulder Elbow Surgeons score, Visual Analog Scale, and Western Ontario Osteoarthritis of the Shoulder score. SCB values were calculated for each region, for each procedure, and at both one and two years postoperatively. To determine the variability of potential SCBs within each region, simulated datasets were created to determine a distribution of possible calculated SCBs.

Results

A total of 380 anatomic TSA patients and 543 reverse TSA patients were included for analysis. There was a high degree of variability of SCB values when stratified by procedure, time, and region. While some simulated datasets did produce homogenous SCB distributions among regions, some outcome measures demonstrated a large heterogeneity in distribution among regions, with concomitant large distributions of values within individual regions.

Conclusions

There is notable heterogeneity of SCB values when stratified by region or time. The current method of citing previously published SCB values for determining the efficacy of an intervention may be inappropriate. It is likely that this variability holds true in other areas of orthopedics.

The minimal clinically important differences of the Simple Shoulder Test are different for different arthroplasty types

BACKGROUND

Preoperative and postoperative patient self-reported measures are the key to understanding the benefit of shoulder arthroplasty for patients with different diagnoses and having different surgical approaches. The minimal clinically important difference (MCID) for patient-reported outcomes such as the Simple Shoulder Test (SST) is often used to document the amount of improvement that is of importance to the patient; however, the MCID may differ for different types of shoulder arthroplasty. The objective of this study was to report the MCID of the SST and the MCID of the percentage of maximal possible improvement (%MPI) for 5 different arthroplasty types.

METHODS

Eight hundred eighty-seven patients undergoing shoulder arthroplasty with preoperative SST scores, 2-year postoperative SST scores, and patient satisfaction were included. The sample comprised 368 patients undergoing anatomic total shoulder arthroplasty (aTSA), 330 patients undergoing ream-and-run arthroplasty (R&R), 80 patients undergoing reverse total shoulder arthroplasty (rTSA), 53 patients undergoing cuff tear arthropathy arthroplasty, and 56 patients undergoing hemiarthroplasty. For each type of arthroplasty, the anchor-based method was used for calculating the MCID for both absolute SST scores and %MPI.

RESULTS

Significant improvements in SST values were seen for all arthroplasty types. The MCID for SST change was 2.3 overall but ranged from 1.6 for aTSA, to 2.6 for R&R, to 3.7 for rTSA. The MCID for %MPI was 32% overall but ranged from 22% for aTSA to 42% for hemiarthroplasty. The percentage of patients exceeding the MCID threshold was highest for aTSA at 96% and lowest for hemiarthroplasty at 61%.

CONCLUSION

The same MCID value may not be appropriate for different types of shoulder arthroplasty. This study reports MCID thresholds that can be used when assessing the effectiveness for each of the common types of shoulder arthroplasty.

Time to Achieving Clinically Significant Outcomes After Meniscal Allograft Transplantation

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Midterm clinical outcome of uncemented short-stem reversed shoulder arthroplasty

INTRODUCTION

While the incidence of reverse total shoulder arthroplasty (rTSA) is increasing constantly, newer implants with designs other than the classic Grammont geometry are gaining importance. More anatomic inclination angles and lateralization are supposed to have a positive impact on clinical results and complication rates. Presentation of midterm results therefore is important to support these assumptions. The aim of this study was to report the midterm clinical outcome of primary rTSA with an uncemented humeral short-stem prosthesis (USSP) with a humeral inclination angle of 145° and the analysis of different variables on the outcome.

METHODS

This is a retrospective study of all patients with primary rTSA using an USSP and a combined humeral inclination angle of 145° (Ascend™ flex, Stryker) with a minimum clinical follow-up of 2 years. The implant combines a 132.5° inclination for the humeral stem with an additional 12.5° for the polyethylene inlay. Primary outcomes were patient-reported outcome measures: ASES score, simple shoulder test (SST) and subjective shoulder value (SSV). Secondary outcomes were complication and revision rates. We analyzed different variables: preoperatively gender, age, indication for surgery and status of rotator cuff. Also, the glenoid morphology was classified according to Walch and a proximal humerus cortical bone thickness measurement (CBT avg) of 6 mm was used as a threshold for osteoporosis. Postoperatively, we analyzed different radiologic parameters: filling ratio, distalization and lateralization angles according to Boutsiadis.

RESULTS

A total of 84 out of 99 (85%) patients with a mean FU of 46.7 months (range 24-80 months) could be included: 62 women and 22 men with a mean age of 74.7 years. Mean ASES score significantly increased from 47 preoperatively to 85.8 at the last follow-up (p = 0.001). The postoperative SST reached an average of 65.3 and the mean SSV was 83%. None of the variable parameters analyzed could be identified as a risk factor for a lower outcome defined as a SSV < 70. Three patients (3.6%) had a complication: one incomplete lower plexus lesion, one dislocation and one major hematoma. Surgical revision was needed in two cases (2.4%).

CONCLUSION

The midterm clinical outcome of primary reverse total shoulder arthroplasty (rTSA) with an uncemented humeral short stem and a humeral inclination angle of 145° showed good-to-excellent results with a low complication and revision rate independent from a wide range of pre- and postoperative variables. PROMs are comparable to those reported for anatomic TSA with a low complication rate, different to historical studies especially with the Grammont design.

LEVEL OF EVIDENCE

Treatment study, Level IV.

Substantial Inconsistency and Variability Exists Among Minimum Clinically Important Differences for Shoulder Arthroplasty Outcomes: A Systematic Review

BACKGROUND

As the value of patient-reported outcomes becomes increasingly recognized, minimum clinically important difference (MCID) thresholds have seen greater use in shoulder arthroplasty. However, MCIDs are unique to certain populations, and variation in the modes of calculation in this field may be of concern. With the growing utilization of MCIDs within the field and value-based care models, a detailed appraisal of the appropriateness of MCID use in the literature is necessary and has not been systematically reviewed.

QUESTIONS/PURPOSES

We performed a systematic review of MCID quantification in existing studies on shoulder arthroplasty to answer the following questions: (1) What is the range of values reported for the MCID in commonly used shoulder arthroplasty patient-reported outcome measures (PROMs)? (2) What percentage of studies use previously existing MCIDs versus calculating a new MCID? (3) What techniques for calculating the MCID were used in studies where a new MCID was calculated?

METHODS

The Embase, PubMed, and Ovid/MEDLINE databases were queried from December 2008 through December 2020 for total shoulder arthroplasty and reverse total shoulder arthroplasty articles reporting an MCID value for various PROMs. Two reviewers (DAK, MAM) independently screened articles for eligibility, specifically identifying articles that reported MCID values for PROMs after shoulder arthroplasty, and extracted data for analysis. Each study was classified into two categories: those referencing a previously defined MCID and those using a newly calculated MCID. Methods for determining the MCID for each study and the variability of reported MCIDs for each PROM were recorded. The number of patients, age, gender, BMI, length of follow-up, surgical indications, and surgical type were extracted for each article. Forty-three articles (16,408 patients) with a mean (range) follow-up of 20 months (0.75 to 68) met the inclusion criteria. The median (range) BMI of patients was 29.3 kg/m2 (28.0 to 32.2 kg/m2), and the median (range) age was 68 years (53 to 84). There were 17 unique PROMs with MCID values. Of the 112 MCIDs reported, the most common PROMs with MCIDs were the American Shoulder and Elbow Surgeons (ASES) (23% [26 of 112]), the Simple Shoulder Test (SST) (17% [19 of 112]), and the Constant (15% [17 of 112]).

RESULTS

The ranges of MCID values for each PROM varied widely (ASES: 6.3 to 29.5; SST: 1.4 to 4.0; Constant: -0.3 to 12.8). Fifty-six percent (24 of 43) of studies used previously established MCIDs, with 46% (11 of 24) citing one study. Forty-four percent (19 of 43) of studies established new MCIDs, and the most common technique was anchor-based (37% [7 of 19]), followed by distribution (21% [4 of 19]).

CONCLUSION

There is substantial inconsistency and variability in the quantification and reporting of MCID values in shoulder arthroplasty studies. Many shoulder arthroplasty studies apply previously published MCID values with variable ranges of follow-up rather than calculating population-specific thresholds. The use of previously calculated MCIDs may be acceptable in specific situations; however, investigators should select an anchor-based MCID calculated from a patient population as similar as possible to their own. This practice is preferable to the use of distribution-approach MCID methods. Alternatively, authors may consider using substantial clinical benefit or patient-acceptable symptom state to assess outcomes after shoulder arthroplasty.

CLINICAL RELEVANCE

Although MCIDs may provide a useful effect-size based alternative to the traditional p value, care must be taken to use an MCID that is appropriate for the particular patient population being studied.

Rate of improvement in shoulder strength after anatomic and reverse total shoulder arthroplasty

Background

Methods

Results

Conclusion

Why patients fail to achieve a Patient Acceptable Symptom State (PASS) after total shoulder arthroplasty?

Background

The purpose of this study was to compare patient-reported outcomes (PROs) and range of motion (ROM) measurements between patients achieving and failing to achieve a Patient Acceptable Symptom State (PASS) after anatomic total shoulder arthroplasty (TSA) to determine which PRO questions and ROM measurements were the primary drivers of poor outcomes.

Methods

A retrospective review of a multicenter database identified 301 patients who had undergone primary TSA between 2015 and 2018 with ROM and PRO data recorded preoperatively and at a minimum of two years postoperatively. The primary outcome was the difference in active ROM between patients achieving and failing to achieve the PASS threshold for the American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores. The secondary outcome was the difference in self-reported pain levels between those achieving and failing to achieve a PASS.

Results

Based on the ASES PASS threshold, 87% (261/301) of patients achieved a PASS after TSA, whereas 13% did not. Based on the SANE PASS threshold, 69% (208/301) of patients achieved a PASS after TSA, whereas 31% did not. Patients who failed to achieve a PASS after TSA were younger and had lower short form-12 mental health scores than those who did. There was a significant difference in pain between those who achieved and failed to achieve a PASS after TSA (ASES PASS current shoulder pain 16.5% vs. 95%, P < .001, SANE PASS current shoulder pain 13% vs. 58.1%, P < .001). Those failing to reach a PASS had significantly higher pain levels (ASES PASS Visual Analog Scale pain scores [4.2 vs. 0.4, P < .001] and SANE PASS Visual Analog Scale pain scores [2.0 vs. 0.4, P < .001]) and worse function in nearly all domains of the ASES and Western Ontario Osteoarthritis of the Shoulder index after surgery. There was little difference in ROM between those reaching and failing to reach a PASS (no difference in active external rotation with the arm adducted, active internal rotation at the nearest spinal level, or active internal rotation with the shoulder abducted to 90 degrees for ASES and SANE PASS).

Conclusion

There is variability in the percentage of patients who achieve a PASS after TSA, ranging from 69% to 87% depending on the PRO used to define the threshold. Patients who did not achieve a PASS after TSA were significantly more likely to have pain, whereas there were very few differences in ROM, indicating pain as the primary driver of failing to achieve a PASS. Setting realistic postoperative expectations for pain relief may be important for improving patient-reported results after TSA.