Radiological and functional 24-month outcomes of resurfacing versus stemmed anatomic total shoulder arthroplasty

Low success rate of closed reductions when treating dislocations after reverse shoulder arthroplasty: a study by the ASES Complications of RSA Multicenter Research Group

BACKGROUND

Postoperative dislocation is a known complication following reverse shoulder arthroplasty (RSA), but treatment patterns and outcomes remain unclear. The purpose of this study was to identify treatment patterns, rate of successful closed reductions, and factors associated with unsuccessful closed reductions for dislocations after RSA in a large multicenter patient cohort.

METHODS

A multicenter retrospective review was performed for patients receiving primary or revision RSA from June 2013 to May 2019 across 15 institutions in the United States. Patients who sustained a postoperative shoulder dislocation (defined as complete loss of articulation between the humeral component and glenosphere confirmed on imaging) with a minimum of 3-month follow-up were included. The time from surgery to dislocation, nature of the dislocation, complications associated with the dislocation, initial treatment, success of closed reduction, recurrent dislocations, and subsequent treatments including revision procedures, were recorded. Univariate analysis was performed to identify patient factors associated with failure of an initial closed reduction attempt.

RESULTS

A cumulative postoperative dislocation incidence of 2.1% (n = 138) was observed in the 6621 patients undergoing RSA. The median time to dislocation was 7 weeks (interquartile range = 33 weeks), with 61.6% (n = 85) occurring within the first 90 days after surgery. Initial treatment consisted of closed reduction (n = 87; 63.0%), open reduction (n = 1; 0.7%), revision arthroplasty (n = 43; 31.2%), or benign neglect (n = 7; 5.1%). Those treated without an initial closed reduction had higher incidence of associated complications (45.1% vs. 14.9%). Among patients initially treated with a closed reduction, 27 (31.0%) were successful (required no further interventions), 15 (17.2%) subsequently required a revision procedure, and 43 (49.4%) sustained an additional dislocation. The only patient or surgical factor associated with an unsuccessful closed reduction was increased body mass index (BMI; 31.8 ± 6 vs. 28.9 ± 5.2, P = .02). Of the 43 patients who sustained an additional dislocation, 10 received another closed reduction and 30 received revision surgery. Among the 10 patients who received a second closed reduction, 5 remained stable (50.0%). Overall, 92 patients (66.7%) required a revision arthroplasty procedure during the study period, whereas 22 (22.5%) required multiple revision procedures. Ultimately, 18 patients (13.0%) remained unstable (benign neglect) at final follow-up.

CONCLUSION

In this large multicenter series of postoperative dislocations following RSA, a closed reduction was initially attempted in the majority of patients, but only about one-third were successful and required no further intervention. Unsuccessful closed reductions were associated with higher patient BMI. Revision surgery for dislocations was complicated by a high rate of recurrent dislocations and rerevision surgery.

What are we matching on and why? A systematic review of matched study designs in shoulder arthroplasty

BACKGROUND

Establishing patient-matched cohorts can be a valuable technique for minimizing selection bias in outcomes research pertaining to shoulder arthroplasty. This systematic review evaluated the variety and inconsistency with which matching techniques are employed in matched studies assessing outcomes following shoulder arthroplasty.

METHODS

The PubMed, EMBASE, and Cochrane computerized databases were queried from their inception through December 2023 to identify clinical outcome studies of shoulder arthroplasty that employed a matched study design. Study quality was assessed via the Methodological Index for Non-Randomized Studies criteria. Matching techniques, covariates included, and covariate justification were aggregated.

RESULTS

Among 110 studies encompassing 483,738 shoulder arthroplasties, 82 (74.6%) studies employed direct matching and 28 (25.5%) employed propensity score matching. Seventy-four distinct covariates were used in at least one study, with 86 unique combinations of covariates employed. Studies used a median of 4 covariates (range 1-27). The most common covariates were age (94.5%), sex (89.1%), body mass index (26.4%), smoking (19.1%), and follow-up duration (19.1%). Only 16 (14.6%) studies reported justification for the covariates included.

CONCLUSIONS

There are marked methodological discrepancies among studies using covariate matching methods in the shoulder arthroplasty literature. Future matched studies in shoulder arthroplasty should provide justification for included covariates and properly account for matching in their statistical analyses to enhance the validity of study findings. When patient matching is deemed appropriate, key variables to consider for matching may include patient age, sex, comorbidity burden and, when analyzing multiple clinical conditions, surgical indication.

Stemmed VS stemless total shoulder arthroplasty: a systematic review and meta-analysis

AIM

Anatomic total shoulder arthroplasty (TSA) is commonly used for glenohumeral osteoarthritis (OA) in patients with an intact rotator cuff. The aim of this study was to quantify advantages and disadvantages of the stemmed and stemless designs in terms of clinical outcome and complications.

METHODS

A review was developed based on the PRISMA statement and registered on PROSPERO. Inclusion criteria were comparative studies analyzing stemmed vs. stemless TSA in adults with OA. The literature search was performed in PubMed, Web of Science, and Wiley Cochrane Library up to January 2024. Constant and Murley Score (CMS), Range of Motion, and operative time were documented, as well as complications divided into minor and major complications. The Downs and Black's "Checklist for Measuring Quality" was used to assess risk of bias and quality of evidence.

RESULTS

Out of 1876 articles retrieved; 14 were included in the meta-analysis for a total of 1496 patients (51.4% men, 48.6% women). The CMS was 74.8 points in the stemmed group and 76.9 points in the stemless group, with no differences in both overall score and subscales. No differences were found in elevation and abduction, while external rotation was 3.9° higher in the stemless group (p < 0.05) No differences were found in operating time and overall complications. However, deep infections were higher in the stemless group (2.2% vs. 0.8%, p < 0.05). The quality was assessed as poor, fair, good, and excellent in 0, 2, 7, and 5 studies, respectively.

CONCLUSION

Stemless TSA may offer minor advantages in terms of external rotation, although the clinical relevance appears doubtful. On the other hand, a lower deep infection rate was documented for stemmed implants. Overall, stemmed and stemless TSA provided good clinical results, with similar benefits in terms of clinical outcomes and complications.

Disease diagnosis and arthroplasty type are strongly associated with short-term postoperative patient-reported outcomes in patients undergoing primary total shoulder arthroplasty

BACKGROUND

Prognostic factors for total shoulder arthroplasty (TSA) clinical outcomes are incompletely understood. This study investigates the associations of preoperative patient, disease-specific, and surgical factors with 1-year postoperative PENN Shoulder Score (PSS) in patients undergoing primary TSA.

METHODS

Cleveland Clinic patients undergoing primary anatomic TSA (aTSA) or reverse TSA (rTSA) for glenohumeral osteoarthritis (GHOA) or rotator cuff tear arthropathy (CTA) between February 2015 and August 2019, and having complete preoperative and 1-year postoperative patient-reported outcome measures (PROMs), were included. Twenty preselected preoperative patient, disease-specific, and surgical factors were used to fit multivariable models for 1-year PSS and its subscores.

RESULTS

Of 1427 eligible primary TSAs, 1174 had 1-year follow-up by PROMs (82%), with 1042 analyzed after additional exclusions, including 30% rTSAs for CTA (n = 308), 26% rTSAs for GHOA (n = 275), and 44% aTSAs for GHOA (n = 459). All PROMs showed statistically significant improvements postoperatively, with 89% of patients reaching an acceptable symptom state. Lower 1-year PSS was associated with younger age, female sex, current smoking, chronic pain diagnosis, history of prior surgery, worker's compensation claim, lower preoperative mental health, lower baseline PSS, absence of glenoid bone loss, and diagnosis-arthroplasty type (CTA-rTSA < GHOA-rTSA < GHOA-aTSA). The most important prognostic factors associated with 1-year PSS were diagnosis-arthroplasty type, baseline mental health status, and insurance status.

CONCLUSIONS

Disease diagnosis, arthroplasty type, and several other baseline factors are strongly and individually associated with PROMs following primary TSA, with patients undergoing aTSA for GHOA demonstrating the highest PROM scores at 1-year follow-up. Patient, disease-specific, and surgical factors can be used to guide postoperative prognosis following primary TSA for improved preoperative patient counseling regarding expected outcomes of these procedures.

Periprosthetic shoulder infection management: one-stage should be the way: a systematic review and meta-analysis

BACKGROUND

There is still no consensus among surgeons on whether to perform a 1- or 2-stage surgical revision in infected shoulder arthroplasties. The aim of this systematic review and meta-analysis is to rigorously synthesize published studies evaluating the clinical outcomes, recurrence of infection, and other clinical complications in order to discuss which is the best strategy for treating periprosthetic joint infection after shoulder arthroplasty.

METHODS

Upon research using the PubMed, Scopus, and Web of Science databases, in November 2022, studies that presented 1- or 2-stage surgical revision as a treatment for periprosthetic joint infection after shoulder arthroplasty and assessed the reinfection rate on these patients, as well as other clinical outcomes, with a minimum follow-up of 12 months, were included. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) score. Reinfection and complication rates were extracted, and pooled estimates were calculated using the random-effect model.

RESULTS

After careful screening, 44 studies were included, 5 reporting on 1-stage and 30 on 2-stage revisions and 9 assessing both strategies. A total of 185 shoulders were reported in 1-stage revision studies, whereas 526 shoulders were reported in 2-stage revision studies. The overall pooled random-effects reinfection rate was 6.68% (95% confidence interval [CI]: 3.76-10.13), with low heterogeneity (I2 = 28%, P = .03). One-stage revision showed a reinfection rate of 1.14% (95% CI: 0.00-4.88), whereas 2-stage revision analysis revealed a reinfection rate of 8.81% (95% CI: 4.96-13.33). There were significant statistical differences between 1- and 2-stage reinfection rates (P = .04). The overall pooled rate for other clinical complications was 16.76% (95% CI: 9.49-25.15), with high heterogeneity (I2 = 70%, P < .01). One-stage revision had a complication rate of 6.11% (95% CI: 1.58-12.39), whereas the 2-stage revision complication rate was 21.26% (95% CI: 11.51-32.54). This difference was statistically significant (P = .03).

CONCLUSIONS

This is the first systematic review and meta-analysis showing significant statistical differences between 1- and 2-stage surgical revision in infected shoulder arthroplasties. Provided the right conditions exist, 1-stage revision shows better results in infection control, with lower clinical complications and possible better clinical outcomes.

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.

Clinical results and 10-year survivorship of the Synthes Epoca resurfacing total shoulder arthroplasty

Aims

This prospective cohort study reports the 10-year survivorship, patient-reported outcome measures and radiographic outcomes of the first series of the Epoca resurfacing head total shoulder arthroplasty.

Methods

From July 2008 to July 2014, 59 Epoca resurfacing head total shoulder arthroplasties were implanted in 50 patients by a single surgeon. Minimum 4.8 year and maximum 11.3 year follow-up (mean: 7.9 years) was analysed using the latest available Oxford Shoulder Score. Kaplan-Meier survivorship analysis was performed with revision as the end point. Most recent radiographs were reviewed for component radiolucency, osteolysis and proximal humeral migration.

Results

Two shoulders underwent revision (3.4%); one for pain with posterior subluxation following a fall, the other for pain with failure of the glenoid. Kaplan-Meier analysis revealed 10-year survivorship of 98.2% (95% confidence intervals: 88.0%-99.8%). Mean Oxford Shoulder Score improved significantly compared to pre-operative values from 18.2 (5-45) to 46.6 (36-48) (p < 0.001). Fifty-three shoulders underwent radiographic analysis (89.8%). This revealed humeral radiolucency in two cases (3.8%), glenoid radiolucency in three cases (5.7%) and radiographic rotator cuff failure in eight cases (15.1%).

Conclusion

This prospective cohort study shows excellent 10-year survivorship, medium to long-term clinical and radiological results and for the Synthes Epoca resurfacing head total shoulder arthroplasty.

Evidence level

IV.

Clinical and Radiographic Outcomes of Total Shoulder Arthroplasty With a Nonspherical Humeral Head and Inlay Glenoid in Elite Weight Lifters: A Prospective Case Series

Background:

Weight lifting after total shoulder arthroplasty (TSA) can place significant stresses on implants that could lead to instability, loosening, and increased wear. A TSA system with nonspherical humeral head resurfacing and inlay glenoid—which improves the biomechanics and thus reduces instability, wear, and potential loosening—may be able to tolerate repetitive loads from weight lifting.

Purpose:

To determine clinical and radiographic outcomes after TSA in weight lifters.

Study Design:

Case series; Level of evidence, 4.

Methods:

We prospectively enrolled 16 weight lifters (mean ± SD age, 57.2 ± 7.8 years; 15 male) undergoing primary anatomic TSA (n = 17 shoulders, 1 staged bilateral) with nonspherical humeral head resurfacing and inlay glenoid replacement for glenohumeral osteoarthritis between February 2015 and February 2019. Exclusion criteria were rotator cuff deficiency, revision TSA, post-traumatic arthritis, and inflammatory arthritis. Outcome measures included the rate of return to weight lifting, results of patient-reported outcome measures (Penn Shoulder Score, Kerlan-Jobe Orthopaedic Clinic, and 12-Item Veterans RAND Health Survey), radiographic outcomes, and complication rate.

Results:

Follow-up was obtained on all patients at a mean of 38 months (range, 14-63 months). All patients returned to competitive weight lifting at 15.6 ± 6.9 weeks. Compared to the preoperative weight lifting level, at last follow-up patients reported performance at the following level: lighter weight, 1 (6%); same weight, 8 (50%); heavier weight, 7 (44%). Preoperative eccentric posterior glenoid wear was common (71% Walch B2 classification; 12/17), but posterior humeral subluxation improved at follow-up according to the Walch index (mean, 55.5% preoperative vs 48.5% postoperative; P < .001) and contact point ratio (mean, 63.9% preoperative vs 50.1% postoperative; P < .001). Pre- to postoperative improvements were seen in Penn Shoulder Score (44.3 vs 82.6; P < .001), Kerlan-Jobe Orthopaedic Clinic (50.6 vs 91.1; P < .001), and 12-Item Veterans RAND Health Survey physical component score but not mental component score. No signs of radiographic loosening were detected in follow-up images, nor were there any postoperative instability episodes or revision surgeries.

Conclusion:

There were substantial improvements in shoulder function and a high rate of return to weight lifting after TSA with a nonspherical humeral head resurfacing and inlay glenoid component. Radiographically, the humeral head centralized on the glenoid after surgery, and there was no evidence of component loosening at a mean 38-month follow-up.

The Schulthess local Shoulder Arthroplasty Registry (SAR): cohort profile

PURPOSE

Clinical registries are essential for evaluation of surgical outcomes. The Schulthess Shoulder Arthroplasty Registry (SAR) was established in 2006 to evaluate safety, function, quality-of-life and patient satisfaction in patients undergoing shoulder arthroplasty.

PARTICIPANTS

Adult patients undergoing anatomic or reverse shoulder joint replacement at the Schulthess Klinik, a high-volume, leading orthopaedic surgery centre in Zürich, Switzerland.

FINDINGS TO DATE

Between March 2006 and December 2019, the registry covered 98% of eligible operations. Overall, 2332 patients were enrolled with a total of 2796 operations and 11 147 person-years of follow-up. Mean age at baseline was 71 (range: 20-95), 65% were women. Most common indication was rotator cuff tears with osteoarthritis (42%) and the mean preoperative Constant Score was 31 (±15). The most frequent arthroplasty type was reverse, increasing from 61% in 2006-2010 to 86% in 2015-2019. Functional recovery peaked at 12-month postoperatively and did not show a clinically relevant deterioration during the first ten follow-up years. Since its establishment, the registry was used to address multiple pertinent clinical and methodological questions. Primary focus was on comparing different implant configurations (eg, glenosphere diameter) and surgical techniques (eg, latissimus dorsi transfer) to maximise functional recovery. Additionally, the cohort contributed to the determination of the clinical relevance and validity of radiological monitoring of cortical bone resorption and scapular notching. Finally, SAR data helped to demonstrate that returning to sports was among key patient expectations after reverse shoulder arthroplasty.

FUTURE PLANS

As first patients are approaching the 15 years follow-up landmark, the registry will continue providing essential data on long-term functional outcomes, implant stability, revision rates and aetiologies as well as patient satisfaction and quality-of-life. In addition to research and quality-control, the cohort data will be brought back to the patients by bolstering real-time clinical decision support.

The short- to midterm effectiveness of stemless prostheses compared to stemmed prostheses for patients who underwent total shoulder arthroplasty: a meta-analysis

BACKGROUND

To systematically compare the short- to midterm effectiveness of stemless prostheses to that of stemmed prostheses for patients who underwent total shoulder arthroplasty (TSA) and to provide a guideline for clinical decision-making.

METHODS

PubMed, the Cochrane Library, and Web of Science were searched with the given search terms until July 2019 to identify published articles evaluating the clinical outcomes for stemless prostheses compared with stemmed prostheses for patients who underwent TSA. Data extraction and the quality assessment of the included studies were independently performed by two authors. Stata software 14.0 was used to analyze and synthesize the data.

RESULTS

Two randomized controlled trials and six case-controlled studies with a total of 347 shoulders were included in this meta-analysis. The results of this meta-analysis showed that there were no significant differences between the stemless and stemmed prostheses in terms of the Constant score, pain score, strength, activities of daily living, postoperative range of motion (ROM), and postoperative maximum active ROM.

CONCLUSIONS

This is the first meta-analysis reporting the clinical results of stemless TSA in the short- to midterm follow-up period. Both types of shoulder prostheses were similar in achieving satisfactory clinical outcomes.

Cemented humeral stem versus press-fit humeral stem in total shoulder arthroplasty: a systematic review and meta-analysis

AIMS

The aim of this study was to evaluate the differences in revision and complication rates, functional outcomes, and radiological outcomes between cemented and press-fit humeral stems in primary anatomical total shoulder arthroplasty (TSA).

MATERIALS AND METHODS

A comprehensive systematic review and meta-analysis was conducted searching for studies that included patients who underwent primary anatomical TSA for primary osteoarthritis or rheumatoid arthritis.

RESULTS

There was a total of 36 studies with 927 cemented humeral stems and 1555 press-fit stems. The revision rate was 5.4% (95% confidence interval (CI) 3.9 to 7.4) at a mean of 89 months for cemented stems, and 2.4% (95% CI 1.1 to 4.7) at a mean of 40 months for press-fit stems. A priori subgroup analysis to control for follow-up periods demonstrated similar revision rates: 2.3% (95% CI 1.1 to 4.7) for cemented stems versus 1.8% (95% CI 1.4 to 2.9) for press-fit stems. Exploratory meta-regression found that longer follow-up was a moderating variable for revision (p = 0.003).

CONCLUSION

Cement fixation had similar revision rates when compared to press-fit stems at short- to midterm follow-up. Rotator cuff pathology was a prevalent complication in both groups but is likely not related to fixation type. Overall, with comparable revision rates, possible easier revision, and decreased operative time, humeral press-fit fixation may be an optimal choice for primary anatomical TSA in patients with sufficient bone stock. Cite this article: Bone Joint J 2019;101-B:1107-1114.

Preoperative Comorbidities and Postoperative Complications Do Not Influence Patient-Reported Satisfaction Following Humeral Head Resurfacing: Mid- to Long-term Follow-up of 106 Patients

Background

Humeral head resurfacing (HHR) has emerged as an alternative treatment for glenohumeral osteoarthritis. We investigated the outcomes of HHR using validated patient-reported outcome (PRO) measures.

Methods

A retrospective review was performed on 213 patients who underwent HHR. A PRO follow-up was performed by administering a questionnaire including the American Shoulder and Elbow Society (ASES) score, Brophy activity survey, short form of the Disabilities of the Arm, Shoulder and Hand (quickDASH) survey, and general shoulder function. PRO scores were stratified by comorbidities and complications.

Results

Survey responses were received from 106 patients (51%), with a mean follow-up of 5.6 ± 1.8 years (range: 9 months to 6.1 years). Preoperative comorbidities were associated with significantly higher quickDASH scores. Postoperative complications were associated with significantly higher rates of current pain, higher visual analog scale scores, night pain, lower subjective shoulder values, and lower ASES pain and total scores. No differences in patient satisfaction were identified between the cohorts with and without preoperative comorbidities and between the cohorts with and without postoperative complications.

Conclusion

In our cross-sectional analysis of mid- to long-term outcomes following HHR, preoperative comorbidities, or postoperative complications had no impact on patient-perceived postoperative satisfaction or most PROs. HHR is clinically viable in a wide variety of patients. Future work is necessary to compare the efficacy of HHR compared with more traditional total shoulder arthroplasty and stemmed hemiarthroplasty regarding long-term outcomes and appropriate indications.

Establishing maximal medical improvement after anatomic total shoulder arthroplasty

BACKGROUND

As a heightened emphasis continues to be placed on value-based health care, quality outcomes following orthopedic procedures must be properly defined. With knowledge of the time to maximal medical improvement following total shoulder arthroplasty (TSA), physician resources can be justly allocated to optimize value in ambulatory orthopedic care.

MATERIALS AND METHODS

A systematic review was conducted to identify studies reporting sequential follow-up at several time points, up to a minimum of 2 years after TSA. Assessment for clinically significant improvements between time intervals was made by using the minimal clinically important difference specific to each patient-reported outcome measure.

RESULTS

We identified 13 studies that fit the criteria to be included in this review, amounting to 984 patients who underwent TSA. Clinically significant improvements in patient-reported outcome scores were appreciated up to 1 year following TSA, but no further clinical significance was seen from 1 year to 2 years. Objective physical examination measurements followed a similar trend, with clinically significant improvements in abduction occurring up to 1 year postoperatively. For both the subjective and objective outcomes, the majority of improvements occurred in the first 3 months after the procedure.

CONCLUSIONS

Following TSA, clinically significant improvements in patient-reported outcomes and objective clinical measurements are seen up to 1 year postoperatively but not beyond this time. This result is important for counseling patients and modifying their expectations prior to surgery as well as for establishing a time frame for maximized outcome evaluation to define the value received from TSA.

Influence of joint kinematics on polyethylene wear in anatomic shoulder joint arthroplasty

BACKGROUND

Despite the positive results in total shoulder arthroplasties (TSAs), a higher revision rate is documented compared with total hip and knee replacements. Wear is the possible main cause of TSA failure in the long-term. This study investigated the effect of joint kinematics and the influence of the rotator cuff on the polyethylene wear performance in an anatomic TSA.

METHODS

Lifting a load of 2 kg with an abduction/adduction of 0° to 90° was simulated for 2 × 10⁶ cycles as a primary motion using a fully kinematic joint simulator. A combined rotation in anteversion-retroversion of ±5° and ±10° was also simulated. The force in the superior-inferior direction and the axial joint compression were applied under force control based on in vivo data of the shoulder. A soft tissue restraint model was used to simulate an intact and an insufficient rotator cuff.

RESULTS

The highest wear rate in the intact rotator cuff group was 58.90 ± 1.20 mg/10⁶ cycles with a combined rotation of ±10°. When an insufficient rotator cuff was simulated, the highest polyethylene wear rate determined was 79.67 ± 4.18 mg/10⁶ cycles.

CONCLUSIONS

This study confirms a high dependency of the polyethylene wear behavior and dimension on the joint kinematics in total shoulder replacement. This can be explained by an increasing cross-shear stress on the polyethylene component. The results obtained indicate that additional combined kinematics are an indispensable part of wear tests on anatomic shoulder replacements.

Clinical and radiological results 7 years after Copeland shoulder resurfacing arthroplasty in patients with primary glenohumeral osteoarthritis: an independent multicentre retrospective study

PURPOSE

The aim of this multicentre cohort study was to evaluate the midterm outcomes and survival after cementless stemless resurfacing arthroplasty (CSRA) in a series of 33 shoulders in 27 patients with primary osteoarthritis.

METHODS

Clinical outcome assessment included: Constant-Murley score (CMS); Simple Shoulder Test (SST); Disability of Arm, Shoulder, Hand (DASH); EuroQol-5D (EQ-5D) utility scores; Numerous Rating Scale (NRS) for pain. Radiographs were assessed by two independent observers for oversizing, radiolucency, glenohumeral subluxation, glenoid erosion and subsidence. Correlations between the clinical and radiological outcomes were calculated. Complications were registered, and revision and survival rates were calculated.

RESULTS

Mean age at time of surgery and mean follow-up time were, respectively, 67.7 (range 50.2-85.1) and 7.2 years (range 5.7-9.3 years). Means (SD) for CMS, age- and gender-adjusted CMS, SST, DASH and EQ-5D utility scores were: 56.4 (20.2), 76.5 (25.0), 54.0 (29.8), 37.6 (23.3) and 0.8 (0.1), respectively. NRS for pain was 2.0 and 3.8, respectively, in rest and during activities. Radiographic assessment of the CSRAs showed oversizing in 54.5%; radiolucency in 18.2%; superior glenohumeral subluxation in 33.3%; glenoid erosion in 45.5%; and subsidence in 3.0%. Perioperative complications did not occur. Revision surgery was performed in one patient (3.0%).

CONCLUSION

For primary osteoarthritis, the CSRA showed good clinical but poor radiological outcomes at midterm follow-up.