Cementless surface replacement arthroplasty of the shoulder for osteoarthritis: results of fifty Mark III Copeland prosthesis from an independent center with four-year mean follow-up

Glenoid wear and migration pattern of a humeral head resurfacing implant: a prospective study using radio stereometric analysis

Background

The humeral head resurfacing arthroplasty (HHR) is normally used as a hemi shoulder arthroplasty and has been in use for the treatment of Gleno-Humeral osteoarthritis (OA) of the shoulder for more than 30 years. Some studies, however, shows that anatomical total shoulder arthroplasty provides better improvement in function than a HHR for patients with OA. Reasons for this may be a progressive glenoid wear (GW) or loosening of the HHR. We, therefore, wanted to investigate the migration pattern of the HHR and also GW by using radio stereometric analysis (RSA).

Methods

21 patients (21 shoulders) with OA and a mean age of 64 years were enrolled in the study. They all received the Copeland humeral resurfacing head and were followed for 2 years with RSA. We evaluated the clinical outcome at 2 years with Western Ontario Osteoarthritis of the Shoulder (WOOS), EuroQol 5 dimension 3L and Constant Shoulder Score. In addition, we assessed data on WOOS and revisions until 5 years follow-up by using the local clinic data within the Swedish Shoulder Arthroplasty Register.

Results

After an initial migration at two months the implants were stable in relation to the humerus with no statistically significant difference between the 2 months and the 2 years value (P = .23). The GW continued to increase during the study period with an initial migration of mean 2.3 mm and at 2 years 3.5 mm with a statistically difference between the 6 months and 2 years value (P = .046). The WOOS, EuroQol 5 dimension 3L and Constant Shoulder Score were all improved at 2 years compared to the preoperative values. We found a weak correlation between GW at 2 years and the WOOS score at 2 and 5 years, but these did not reach statistical significance. There were 4 revisions within 5 years after the primary operation, all due to pain.

Conclusion

The marker-free RSA can be used in clinical studies for assessing migration in HHR implants and was also for the first time used to measure GW. The Copeland HHR seems to obtain a secure fixation in the humerus but shows continuous GW up to two years.

Long-term survival of resurfacing humeral hemiarthroplasty

INTRODUCTION

The indication for shoulder resurfacing arthroplasty is controversial, and survival of these implants is somewhat inconsistent. This study aimed to evaluate the long-term survivorship of resurfacing humeral head implants (RHHIs) and determine risk factors for complications and revisions.

MATERIALS AND METHODS

This retrospective cohort study consisted of 275 cases and two types of RHHIs. The survival rate was evaluated using the Kaplan-Meier method and Cox regression for risk factor analysis. Demographic factors were studied, and the change in the humerus centre of rotation (COR) was measured.

RESULTS

The mean follow-up time was 8.7 years (SD 2.7 months, range 2.8-15.9 years). The mean age of the patients was 67.6 years (SD 9.6, range 33.5-84.9). Ten-year cumulative RHHI survival was 94.1%. The cumulative estimate without any complication was 98.9% at 5 years, 80.0% at 10 years and at 15 years it was 61.5%. The most common complication was persistent pain in 13.8% of the RHHIs. The risk factors for complications and revisions were implant type, preoperative conditions and change of COR > 5 mm.

CONCLUSIONS

RRHIs showed excellent long-term survival, but many complications were found. The most common complication was persistent pain, which seemed to be caused by a change of COR and was more related to one type of implant.

Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The treatment of shoulder osteoarthritis in the young patient remains challenging. The higher functional demands and higher expectations of the young patient cohort are often coupled with increased failure and revision rates. Consequently, shoulder surgeons are faced with a unique challenge with implant selection. The aim of this study was to compare the survivorship and reasons for revision of 5 classes of shoulder arthroplasty in patients aged <55 years with a primary diagnosis of osteoarthritis by use of data from a large national arthroplasty registry.

METHODS

The study population included all primary shoulder arthroplasty procedures undertaken for osteoarthritis in patients aged <55 years and reported to the registry between September 1999 and December 2021. Procedures were grouped into the following classes: total shoulder arthroplasty (TSA), hemiarthroplasty resurfacing (HRA), hemiarthroplasty stemmed metallic head (HSMH), hemiarthroplasty stemmed pyrocarbon head (HSPH), and reverse total shoulder arthroplasty (RTSA). The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the first revision. Hazard ratios (HRs) were calculated from Cox proportional hazards models, adjusting for age and sex, to compare revision rates among groups.

RESULTS

There were 1564 shoulder arthroplasty procedures in patients aged <55 years, of which 361 (23.1%) were HRA, 70 (4.5%) were HSMH, 159 (10.2%) were HSPH, 714 (45.7%) were TSA, and 260 (16.6%) were RTSA. HRA had a higher rate of revision than RTSA after 1 year (HRA = 2.51 (95% CI 1.30, 4.83), P = .005), with no difference prior to that time. In addition, HSMH had a higher rate of revision than RTSA for the entire period (HR, 2.69 [95% confidence interval, 1.28-5.63], P = .008). There was no significant difference in the rate of revision for HSPH and TSA when they were compared with RTSA. Glenoid erosion was the most common cause of revision for HRA (28.6% of revisions) and HSMH (50%). Instability/dislocation was the leading cause of revision for RTSA (41.7%) and HSPH (28.6%), and for TSA, the majority of revisions were for either instability/dislocation (20.6%) or loosening (18.6%).

CONCLUSION

These results should be interpreted within the context of the lack of availability of long-term data on RTSA and HSPH stems. RTSA outperforms all implants regarding revision rates at mid-term follow-up. The high early dislocation rate associated with RTSA, as well as the lack of revision options available to address this, indicates that careful selection of patients and a greater appreciation of anatomic risk factors are needed in the future.

Shoulder joint arthroplasty in young patients: Analysis of 8742 patients from the Australian Orthopaedic Association National Joint Replacement Registry

Background

Shoulder replacement is a reliable treatment for the relief of pain and improvement of function in patients with glenohumeral arthritis, rotator cuff arthropathy, osteonecrosis and fracture. Limited data is available comparing revision rates for the different types of shoulder replacement when used in younger patients. This study aims to compare the survivorship of hemi resurfacing, stemmed hemiarthroplasty, total shoulder arthroplasty and reverse total shoulder arthroplasty in younger patients using data from a large national arthroplasty registry.

Methods

Data from the Australian Orthopaedic Association National Joint Replacement Registry was obtained for the period 16 April 2004-31 December 2018. The study population included all shoulder arthroplasty patients aged <65 years. These were stratified into two groups: <55 years and 55-64 years. A total of 8742 primary shoulder arthroplasty procedures were analysed (1936 procedures in the <55 years and 6806 in the 55-64 years age group).

Results

In the <55 years age group, there was no difference in revision rate for total shoulder arthroplasty versus reverse total shoulder arthroplasty at any time point. Reverse total shoulder arthroplasty had a lower revision rate after six months when compared to hemi resurfacing (HRA) (p = 0.031). Also, reverse total shoulder arthroplasty had a higher early rate of revision in the first 12 months compared to hemiarthroplasty (p = 0.018). However, from 2 years reverse total shoulder arthroplasty had a lower revision rate overall (p = 0.029).In the 55-64 years patient age group, reverse total shoulder arthroplasty had a lower earlier revision rate. This was statistically significant compared to hemi resurfacing (HRA) (p = 0.028), hemiarthroplasty (p = 0.049) and total shoulder arthroplasty (p < 0.001).

Conclusion

This study demonstrated that for patients aged <55 years there was no significant difference in the rate of revision when total shoulder arthroplasty and reverse total shoulder arthroplasty were compared. reverse total shoulder arthroplasty had a lower rate of revision when compared to hemi resurfacing and hemiarthroplasty after 2 years. reverse total shoulder arthroplasty had the lowest comparative revision rate in patients aged 55-64 years overall.

Early offset-increasing migration predicts later revision for humeral head resurfacing implants. A randomized controlled radiostereometry trial with 10-year clinical follow-up

In a randomized controlled setting, medium-term implant migration and long-term clinical outcomes were compared for the Copeland and the Global C.A.P. humeral head resurfacing implants (HHRI). Thirty-two patients (mean age 63 years) were randomly allocated to a Copeland (n = 14) or Global C.A.P. (n = 18) HHRI. Patients were followed for 5 years with radiostereometry, Constant Shoulder Score, and the Western Ontario Osteoarthritis of the Shoulder Index (WOOS). WOOS and revision status were also obtained cross-sectionally at a mean 10-year follow-up. At the 5-year follow-up, total translation (TT) was 0.75 mm (95% confidence interval [CI]: 0.53-0.97) for the Copeland HHRIs and 1.15 mm (95% CI: 0.85-1.46) for the Global C.A.P. HHRIs (p = 0.04), but the clinical scores were similar at all follow-ups. The cumulative risks of revision at 5 and 10 years were 29% and 43% for Copeland and 35% and 41% for Global C.A.P HHRIs (p > 0.7). No implants were loose at revision, but HHRIs that were later revised followed an early offset-increasing migration pattern with medial translation and lift-off resulting in a mean 0.53 mm (95% CI: 0.18-0.88) higher TT at the 1-year follow-up compared to non-revised HHRIs. In conclusion, the Global C.A.P. HHRI had higher TT compared with the Copeland HHRI, but clinical scores and revision rates were similar. Nonetheless, revision rates were high and challenge the use of HHRIs. Interestingly, an early radiostereometry evaluated HHRI migration pattern with increased off-set predicted later implant revision.

Mid-term outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared with metal humeral resurfacing and metal stemmed hemiarthroplasty for osteoarthritis in young patients: analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The optimal surgical management of glenohumeral osteoarthritis in young patients remains an unsolved problem. Humeral resurfacing hemiarthroplasty and stemmed hemiarthroplasty using metallic heads are 2 surgical options that avoid the complications of loosening or wear of the glenoid component seen in total shoulder arthroplasty. Despite the potential benefits, improvement in survivorship has not been demonstrated from joint registry studies or other studies at mid-term follow-up. This is predominantly because of glenoid erosion and pain that occur when the metal resurfaced head articulates with the native glenoid. The use of pyrolytic carbon (pyrocarbon) as a resurfacing material has been proposed as an alternative bearing surface thought to reduce glenoid erosion owing to a marked reduction in wear rates in vitro. This study aimed to compare the survivorship of shoulder hemi-resurfacing using pyrocarbon with shoulder hemi-resurfacing and stemmed hemiarthroplasty using metallic heads.

METHODS

Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed for all patients aged <55 years who had undergone a primary shoulder replacement for osteoarthritis from April 16, 2004, to December 31, 2019. The outcomes of shoulder procedures using pyrocarbon hemi-resurfacing were compared with procedures using metal hemi-resurfacing and metal stemmed hemiarthroplasty. The reasons for revision in each arthroplasty class were analyzed. The analyses were undertaken using Kaplan-Meier estimates of survivorship and hazard ratios (HRs) from Cox proportional hazards models.

RESULTS

We analyzed 393 primary shoulder procedures, of which 163 were pyrocarbon hemi-resurfacing procedures, 163 were metal hemi-resurfacing procedures, and 67 were metal stemmed hemiarthroplasties.The cumulative percentage of revision at 6 years was 8.9% for pyrocarbon hemi-resurfacing, 17.1% for metal hemi-resurfacing, and 17.5% for metal stemmed hemiarthroplasty. Pyrocarbon hemi-resurfacing prostheses had a statistically lower revision rate than other hemi-resurfacing prostheses (HR, 0.41; 95% confidence interval, 0.18-0.93; P = .032). Pain, prosthesis fracture, and infection were the key reasons for revision. No pyrocarbon hemi-resurfacing cases were revised for glenoid erosion. In male patients, pyrocarbon humeral resurfacing had a lower cumulative percentage of revision compared with metal stemmed hemiarthroplasty (HR, 0.32; 95% confidence interval, 0.11-0.93; P = .037).

CONCLUSION

Pyrocarbon humeral resurfacing arthroplasty had statistically lower revision rates at mid-term follow-up in patients aged <55 years compared with other hemi-resurfacing procedures.

Long-term results of the uncemented resurfacing shoulder hemiarthroplasty (Global Conservative Anatomic Prosthesis)

BACKGROUND

Treatment with uncemented resurfacing shoulder hemiarthroplasty has proved to be viable for patients with end-stage osteoarthritis at short- and mid-term follow-up. This study was essential to determine whether those outcomes will endure. This study presents the long-term results of the Global Conservative Anatomic Prosthesis (CAP) uncemented resurfacing shoulder hemiarthroplasty (DePuy Synthes, Warsaw, IN, USA).

METHODS

All patients with a diagnosis of glenohumeral osteoarthritis and an intact and clinically sufficient rotator cuff who underwent uncemented resurfacing shoulder hemiarthroplasty between 2007 and 2009 were included. The data of all patients who completed the 10-year follow-up assessments were used for analysis. The visual analog scale pain score, Dutch version of the Simple Shoulder Test score, Constant score, Short Form 12 scores, and physical examination findings were evaluated preoperatively and postoperatively on an annual basis. All complications and revisions were documented. Radiographs were evaluated for loosening, luxation or subluxation, migration, and glenoid erosion.

RESULTS

Of 48 shoulders, 23 (48%, 18 women and 5 men) were available for the 10-year follow-up assessments and their data were used for analysis. The main reasons for dropout were revision (27%) and death (10%). The mean follow-up period of the remaining patients was 10.9 years (range, 9-13 years). The visual analog scale pain score (from 6.5 ± 2.1 to 0.7 ± 1.6, P < .001), Simple Shoulder Test (Dutch version) score (from 22% ± 22% to 79% ± 22%, P < .001), Constant score (from 40 ± 29 to 70 ± 8, P < .001), and Short Form 12 physical score (from 36 ± 7 to 41 ± 12, P = .001) improved significantly compared with preoperative scores. Revision surgery was performed in 13 of the initial 48 shoulders (27%). Most revisions were seen within 7 years postoperatively.

CONCLUSION

Two revisions have been performed in the mid-term to long term because of increased functional outcome scores and the absence of signs of loosening. Nevertheless, the high overall revision rate of 27% between short- and long-term follow-up reflects the need to limit the use of uncemented resurfacing shoulder hemiarthroplasty for the treatment of glenohumeral osteoarthritis.

Anatomic Total Shoulder Arthroplasty versus Hemiarthroplasty for Glenohumeral Osteoarthritis: A Systematic Review and Meta-Analysis

Purpose: Both anatomic total shoulder arthroplasty (TSA) and shoulder hemiarthroplasty (SHA) are used for the management of end-stage glenohumeral osteoarthritis (GHOA). The present study compared TSA and SHA in terms of clinical outcome and complication rate. Methods: This meta-analysis followed the PRISMA guidelines. In October 2021, the following databases were accessed: Web of Science, Google Scholar, Pubmed, Scopus. All clinical trials comparing anatomical TSA versus SHA for GHOA were considered. Results: Data from 11,027 procedures were retrieved. The mean length of the follow-up was 81.8 (16 to 223.20) months. The mean age of the patients was 61.4 ± 8.6 years, and 56.0% (5731 of 10,228 patients) were women. At last follow-up, the age-adjusted constant score was greater following TSA (p < 0.0001), as were active elevation (p < 0.0001), flexion (p < 0.0001), abduction (p < 0.0001), and American Shoulder and Elbow Surgeons Shoulder Score (p < 0.0001). Postoperative pain (p < 0.0001) and revision rate (p = 0.02) were lower in the TSA group. Conclusions: Anatomic TSA performed better than SHA in patients with GHOA.

Clinical and Radiological Results of Hemiarthroplasty and Total Shoulder Arthroplasty for Primary Avascular Necrosis of the Humeral Head in Patients Less Than 60 Years Old

Background: Total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) have shown good clinical outcomes in primary avascular necrosis of the humeral head (PANHH) both in short and long terms. The purpose of this study was to assess the complications, the clinical and radiological outcomes of shoulder arthroplasty in young patients with PANHH. Methods: One hundred and twenty-seven patients aged under 60 years old and suffering from PANHH were operated with arthroplasty. Patients were assessed clinically and radiographically before surgery with a minimum of 2 years of follow up (FU). Results: HA was performed on 108 patients (85%). Two patients were revised for painful glenoid wear after 2 and 4 years. TSA was performed on 19 patients (15%). Five TSA had to be revised for glenoid loosening (n = 4) or instability (n = 1). Revision rate was 26% with TSA and 2% with HA. There were no significant differences between HA and TSA in terms of clinical outcomes. Conclusions: With a mean FU of 8 years, HA and TSA improved clinical outcomes of patients with PANHH. HA revisions for painful glenoid wear were rare (2%). The revision rate was excessively high with TSA (26%).

Outcome and revision rate of uncemented humeral head resurfacing: Mid-term follow-up study

BACKGROUND

Glenohumeral osteoarthritis (OA) is a common cause of pain and disability affecting nearly a third of the world’s population over 60 years of age. As in other joints, shoulder arthroplasty appears to be the most effective treatment. The implant design has evolved during time transitioning to shorter humeral stem lengths or even stemless components.

AIM

To evaluate the medium-term outcome and survival of a cementless humeral head resurfacing (HHR) in a group of patients affected with OA or avascular necrosis.

METHODS

This is a retrospective study of prospectively collected data using HHR in 23 patients (15 female and 8 male) after a 7.4 year follow-up. The collected data included clinical and radiographical evaluation. The Constant score, the visual analogue scale, and a clinical evaluation of range of motion were registered pre- and postoperatively. Fifteen patients affected with OA (2 cases of mild, 6 moderate, and 7 severe) and 10 with avascular necrosis (stage III according to Cruess classification) were enrolled. X-rays were evaluated to detect loosening signs, degenerative changes, and superior humeral head migration. Magnetic resonance preoperatively was also performed to assess the rotator cuff status. Tendon integrity was mandatory to implant the HHR.

RESULTS

In total, 19 patients (21 shoulders) completed the follow-up. Data on 4 shoulders, in 4 patients, were lost because of prosthesis failure. The global revision rate was 16%. A statistically significant improvement in the mean Constant score, visual analogue scale, and range of motion have been reported. No signs of loosening were registered, while in 12 cases a glenoid erosion was found. The osteophytes appeared 7 times on the humeral side and 12 on the glenoid. Superior humeral migration was recorded in only 1 case.

CONCLUSION

HHR remains a reasonable option in patients with an intact rotator cuff for the treatment of OA and avascular necrosis.

Kinematic 3-D motion analysis of shoulder resurfacing hemiarthroplasty - An objective assessment method

Shoulder replacement is indicated in the treatment of pain due to osteoarthritis. Few studies have objectively assessed range of motion (RoM) gains at different post-operative time points. This is a prospective 3D motion analysis study to objectively quantify RoM changes at multiple time points following shoulder resurfacing arthroplasty (SRA) for primary gleno-humeral osteoarthritis, comparing it with clinically measured RoM. Clinical assessment, Visual Analog Scale (VAS) pain score, Constant-Morley (CS) and Oxford Shoulder Score (OSS) were recorded. Motion analysis was performed for RoM and three activities of daily living tasks (ADL), pre-operatively and post-operatively at 4 and 12 months. Nineteen shoulders in fifteen patients were included. The mean age was 72 years (range 52-84). There were significant improvements in external and internal rotation, ability to place the hand behind the head and reach the fifth lumbar vertebra, at 4 months on clinical examination and kinematic analysis with no further improvements at 12 months. There was significant improvement in abduction at 4 months with further improvement at 12 months, which was significantly more than noted on clinical assessment. In contrast, kinematic analysis showed a reduction in flexion between 4 and 12 months, while clinically there appeared to be an improvement between these time periods. This is the first study to prospectively utilise objective kinematic 3-D motion analysis in addition to clinical measurements and outcome scores, to investigate the outcome of resurfacing arthroplasty at multiple time points after surgery, providing an understanding into the trends of change in these parameters.

Resurfacing hemiarthroplasty versus stemmed hemiarthroplasty for glenohumeral osteoarthritis: a meta-analysis

Background

Though total shoulder arthroplasty (TSA) has been an acknowledged treatment option for glenohumeral osteoarthritis, resurfacing hemiarthroplasty (RHA) and stemmed hemiarthroplasty (SHA) may be preferred in some circumstances by surgeons, especially for treating young or active patients. However, decision-making between the RHA and SHA is controversial. Therefore, we conducted a meta-analysis to systematically compare two surgical procedures in terms of postoperative functional outcomes, range of motion (ROM), pain relief, complication rates, risk of revision.

Methods

The PubMed, Embase, Web of Science and Cochrane Library were searched from inception to January 1, 2020, for all articles that compared the clinical effectiveness and safety of RHA with SHA. All eligible studies were selected based on certain screening criteria. Two investigators independently conducted the quality assessment and extracted the data. Fixed-effect and random-effect models were used for pooled results according to the degree of heterogeneity. All statistical analyses were performed by employing Stata software 14.0.

Results

A total of six comparative studies involving 2568 shoulders (1356 RHA and 1212 SHA) were included in the final analysis. Patients were followed up for at least 1 year in each study. Pooled results showed that RHA was associated with a better visual analog scale (SMD 0.61, p = 0.001) but higher revision rates (OR 1.50, p = 0.016) when compared to SHA. There were no significant differences in functional outcomes, such as Constant-Murley score (SMD 0.06, P = 0.878), American Shoulder and Elbow Surgeons score (SMD 0.05, P = 0.880), Western Ontario Osteoarthritis of the Shoulder index (SMD 0.43, p = 0.258) and quick-Disabilities of the Arm, Shoulder and Hand score (SMD 0.06, p = 0.669). In addition, no differences were observed in forward flexion (SMD 0.16, p = 0.622), external rotation (SMD -0.17, P = 0.741) and overall complication rates (OR 1.42, p = 0.198).

Conclusion

This is the first meta-analysis to investigate the clinical efficacy and safety of RHA in comparison with SHA for the treatment of glenohumeral osteoarthritis. The results demonstrated that the two surgical techniques were equivalent in terms of postoperative functional outcomes and complication rate. However, RHA provided greater pain relief but posed a higher risk for revision than SHA. More high-quality studies with long-term follow up are warranted to give more convincing evidence.

Overstuffing in resurfacing hemiarthroplasty is a potential risk for failure

PURPOSE

Literature describes the concern of an overstuffed shoulder joint after a resurfacing humeral head implant (RHHI). The purpose of this study was to evaluate inter-observer variability of (1) the critical shoulder angle (CSA), (2) the length of the gleno-humeral offset (LGHO), and (3) the anatomic center of rotation (COR) in a patient population operated with a Global Conservative Anatomic Prosthesis (CAP) RHHI. The measurements were compared between the revision and non-revision groups to find predictive indicators for failure.

METHODS

Pre- and postoperative radiographs were retrieved from 48 patients who underwent RHHI from 2007 to 2009 using a Global CAP hemiarthroplasty for end-stage osteoarthritis. This cohort consisted of 36 females (12 men) with a mean age of 77 years (SD 7.5). Two musculoskeletal radiologist and two specialized shoulder orthopedic surgeons measured the CSA, LGHO, and COR of all patients.

RESULTS

The inter-observer reliability showed excellent reliability for the CSA, LGHO, and the COR, varying between 0.91 and 0.98. The mean COR of the non-revision group was 4.9 mm (SD 2.5) compared to mean COR of the revision group, 8 mm (SD 2.2) (p < 0.01). The COR is the predictor of failure (OR 1.90 (95%Cl 1.19-3.02)) with a cut of point of 5.8 mm. The mean CSA was 29.8° (SD 3.9) There was no significant difference between the revision and non-revision groups (p = 0.34). The mean LGHO was 2.6 mm (SD 3.3) post-surgery. The mean LGHO of the revision group was 3.9 (SD 1.7) (p = 0.04) post-surgery. Despite the difference in mean LGHO, this is not a predictor for failure.

CONCLUSION

The CSA, LGHO, and COR can be used on radiographs and have a high inter-observer agreement. In contrast with the CSA and LGHO, we found a correlation between clinical failure and revision surgery in case of a deviation of the COR greater than 5 mm.

TRIAL REGISTRATION

Institutional review board, number: ACLU 2016.0054, Ethical Committee number: CBP M1330348. Registered 7 November 2006.

Increased use of total shoulder arthroplasty for osteoarthritis and improved patient-reported outcome in Denmark, 2006-2015: a nationwide cohort study from the Danish Shoulder Arthroplasty Registry

Background and purpose - Osteoarthritis has become the most common indication for shoulder arthroplasty in Denmark, and the treatment strategies have changed towards the use of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty. We investigated whether changes in the use of arthroplasty types have changed the overall patient-reported outcome from 2006 to 2015. Patients and methods - We included 2,867 shoulder arthroplasties performed for osteoarthritis between 2006 and 2015 and reported to the Danish Shoulder Arthroplasty Registry. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as patient-reported outcome. The raw score was converted to a percentage of a maximum score. General linear models were used to analyze differences in WOOS. Results - The proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty increased from 3% and 7% in 2006 to 53% and 27% in 2015. The mean WOOS score was 70 (SD 26) after resurfacing hemiarthroplasties (n = 1,258), 68 (SD 26) after stemmed hemiarthroplasty (n = 500), 82 (SD 23) after anatomical total shoulder arthroplasties (n = 815), and 74 (SD 23) after reverse shoulder arthroplasties (n = 213). During the study period, the overall WOOS score increased with 18 (95% CI 12-22) in the univariate model and 10 (CI 5-15) in the multivariable model, and the WOOS scores for anatomical total shoulder arthroplasty increased by 14 (CI 5-23). Interpretation - We found an increased WOOS score from 2006 to 2015, which was primarily related to a higher proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty towards the end of the study period, and to improved outcome of anatomical total shoulder arthroplasty.

Progressive glenoid bone loss caused by erosion in humeral head resurfacing

BACKGROUND

Cementless surface replacement of the shoulder represents an alternative to conventional stemmed anatomic prostheses. Glenoid erosion is a well-known complication in hemiarthroplasty. However, there is limited data concerning radiographic evaluation and prognostic factors for this phenomenon.

OBJECTIVES

The aim of our study was to determine the development of glenoid erosion following shoulder resurfacing using a new measurement technique and detect potential prognostic factors.

MATERIALS AND METHODS

We performed a retrospective analysis on 38 shoulders undergoing humeral head resurfacing with a mean follow-up of 65.4 ± 43 months. Clinical and radiographic evaluation followed a standardized protocol including pre- and postoperative Constant score, active range of motion, and X‑rays in true anteroposterior view. Three independent observers performed measurements of glenoid erosion.

RESULTS

We found good interobserver reliability for glenoid erosion measurements (intraclass correlation coefficient [ICC] 0.74-0.78). Progressive glenoid erosion was present in all cases, averaging 5.5 ± 3.9 mm at more than 5 years' follow-up. Male patients demonstrated increased glenoid bone loss within the first 5 years (p < 0.04). The mean Constant score improved to 55.4 ± 23.6 points at the latest follow-up. Younger age was correlated to increased functional outcome. Revision rate due to painful glenoid erosion was 37%.

CONCLUSIONS

Glenoid erosion can be routinely expected in patients undergoing humeral head resurfacing. Painful glenoid erosion leads to deterioration in functional outcome and necessitates revision surgery in a high percentage of cases.

Revision of Failed Resurfacing Hemiarthroplasty: Midterm Results, Survival, and Group Comparison

Shoulder arthroplasty is a valuable option for treating glenohumeral osteoarthritis. Revision surgery for a failed shoulder arthroplasty is associated with difficult procedures, complications, and worse outcomes. Compared with a total joint arthroplasty, a resurfacing prosthesis has the supposed advantages of limited perioperative complications and little bone loss during revision. The aim of this study was to describe patient-reported outcome measures of revision surgery from failed uncemented Global CAP (DePuy, Warsaw, Indiana) resurfacing hemiarthroplasty to total shoulder or reverse shoulder arthroplasty. Eleven patients from 2 collaborating institutes had a failed resurfacing prosthesis. Revision surgery was performed to total shoulder prosthesis in 7 patients and to reverse shoulder prosthesis in 3 patients. Data were missing for 1 patient. Outcomes were monitored using the Constant-Murley score, Dutch Simple Shoulder Test, Short Form-12, visual analog scale for pain, and physical examination. Mean time to revision was 54 months (SD, 15.6 months). No perioperative complications occurred. At 42 months of follow-up (SD, 15.9 months), clinical and patient-reported outcomes were excellent. The Constant-Murley score improved a significant 29 points (P<.01). The visual analog scale pain score decreased from 55 to 5 points (P<.01), and the Dutch Simple Shoulder Test and Short Form-12 scores improved significantly (P≤.02). Five-year survival was 82.6% (95% confidence interval, 71.6%-93.6%). At 3.5-year follow-up, clinical and patient-reported outcome measures had satisfying results. [Orthopedics. 2019; 42(1):e111-e117.].

Low inter-observer agreement among experienced shoulder surgeons assessing overstuffing of glenohumeral resurfacing hemiarthroplasty based on plain radiographs

Background

In a clinical setting, a visual evaluation of post-implant radiographs is often used to assess the restoration of glenohumeral joint anatomy after resurfacing hemiarthroplasty and is a part of the decision-making process, in combination with other parameters, when evaluating patients with inferior clinical results. However, the reliability of this method of visual evaluation has not been reported. The aim of this study was to investigate the inter- and intra-observer agreement among experienced shoulder surgeons assessing overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs.

Methods

Six experienced shoulder surgeons independently classified implant inclination, size of the implant and if the joint seemed overstuffed, in 219 cases of post-implant radiographs. All cases were classified twice 3 weeks apart. Only radiographs with an anterior-posterior projection with a freely visible joint space were used. Non-weighted Cohen’s kappa values were calculated for each coder pair and the mean used as an estimate of the overall inter-observer agreement.

Results

The overall inter-observer agreement for implant size (kappa, 0.48 and 0.41) and inclination angle was moderate in both rounds (kappa, 0.46 and 0.44), but only a fair agreement was found concerning the evaluation for stuffing of the joint (kappa, 0.24 and 0.28). Intra-observer agreement for implant size and stuffing ranged from fair to substantial while the agreement for inclination was moderate to substantial.

Conclusions

Our results indicate that a visual evaluation of plain radiographs may be inadequate to evaluate overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs. Future studies may contribute to elucidate whether reliability increases if consensus on clear definitions and standardized methods of evaluation is made.

Revision shoulder arthroplasty for failed surface replacement hemiarthroplasty

PURPOSE

The aim of this study was to assess the reasons of failure of shoulder surface replacement hemiarthroplasty (SRH) and to evaluate the outcome of revision surgery.

METHOD

The study group included 25 patients (26 shoulders) with failed SRHs. The mean time to revision surgery was 3.6 years. Their functional outcome was evaluated using adjusted Constant-Murley score at mean follow-up of 5.2 years (range 2-16 years).

RESULT

Most common cause of failure was glenoid erosion (42%) and progressive failure of rotator cuff (31%). Median adjusted Constant-Murley score at mean follow-up of 5.2 years was 51.6. Median adjusted Constant-Murley score in patients who had primary diagnosis of osteoarthritis and had revision performed to anatomic TSA (14 shoulders) was 85 (range 40-100) at mean follow-up of 5 years compared to 36.3 (range 20-66.3) in the remaining patients at 5.4 years, p = 0.00008.

CONCLUSION

Revision surgery for failed SRH can be technically challenging with variable results. Most common mode of failure was glenoid erosion. Functional outcomes are better in those with revision performed to anatomic TSA.

Cementless humeral head resurfacing for degenerative glenohumeral osteoarthritis fails at a high rate

Purpose

The aim of the study was to examine clinical and radiographic results of a cementless humeral surface and to evaluate prognostic parameters for implant failure.

Methods

34 shoulders were examined preoperatively and after a mean 2.7 years. Radiographic parameters, Constant scores (CS) and complications were recorded.

Results

The mean CS improved from 27 to 51 points. Eight patients (24%) had an implant revision for secondary glenoid erosion. In the revision group was an increase of the LGHO of 8.4%.

Conclusions

The study shows a high revision-rate (24%). Predictor for an implant failure was an operative changing of the LGHO.

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.

Outcome and revision rate of uncemented glenohumeral resurfacing (C.A.P.) after 5-8 years

BACKGROUND

Resurfacing of the glenohumeral joint for patients with glenohumeral arthritis has gained popularity since the first introduction. We report the mid-term results of the Global C.A.P. uncemented resurfacing shoulder prosthesis (DePuy Synthes).

METHODS

From January 2007 to December 2009, 48 humeral cementless resurfacing prostheses in 46 patients were performed. All patients were diagnosed with primary glenohumeral osteoarthritis. Patients were contacted for review; the Constant Score, visual analog pain scale, Dutch Simple Shoulder Test, SF-12 scores and physical examination were assessed both preoperatively and yearly postoperatively. Complications and revision surgery were documented. Radiographs were evaluated for component size, offset, inclination, height, loosening and subluxation.

RESULTS

Forty-six patients (12 males) with a mean age of 72 years old (range 59-89) were included. At a mean 6.4-year follow-up (range 5-8), the Constant Score, visual analog pain scale and the Dutch Simple Shoulder Test scores improved significantly (p < 0.05) from baseline. Three patients were lost to follow-up. One patient died and two patients were not able to attend the follow-up appointments, due to other health-related issues. Eleven patients (23%) had a revision operation.

CONCLUSIONS

The most important findings of this study of the Global C.A.P. shoulder resurfacing arthroplasty were an increase of range of motion, a reduction of pain complaints, but a concerning high rate of revision after mid-term follow-up.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Risk factors for glenoid erosion in patients with shoulder hemiarthroplasty: an analysis of 118 cases

BACKGROUND

Glenoid erosion is one of the main concerns in shoulder hemiarthroplasty. The goal of this study was to quantify glenoid erosion and to identify risk factors in patients with humeral hemiarthroplasty.

METHODS

There were 118 shoulders in 113 patients available for a standardized retrospective review. Erosion was graded as follows: grade 1, none; grade 2, mild (erosion into subchondral bone); grade 3, moderate (medialization of subchondral bone with hemispheric deformation); or grade 4, severe. The findings were then analyzed for confounding factors using a multivariate analysis.

RESULTS

Mean follow-up was 31 months (range, 5-86 months). Negative predisposing factors for erosion were glenoid cysts (odds ratio, 5.4; P < .001, approximately 3 times more frequent in women), fatty infiltration of the rotator cuff musculature (R, 0.43; P < .001), and rheumatoid arthritis (odds ratio, 3.6; P = .049). A valgus position of the prosthetic head relative to the glenoid (angle >50°) appeared to lead to local destruction of the cartilage. The degree of erosion did not correlate with age and glenoid or humeral head size. Only 1 patient (of 30) with a fracture-type prosthesis developed progressive glenoid erosion.

CONCLUSION

In this series, favorable conditions for resistance to erosion after hemiarthroplasty were lack of glenoid cysts, intact glenoid cartilage, intact rotator cuff musculature, and a fracture situation. Age, the version of the glenoid, and the size of the prosthetic head showed no importance. The use of hemiarthroplasty seems to be associated with glenoid destruction in female patients with impending osteoarthritis, with rheumatoid arthritis, and if the head is implanted in a valgus position.

Anatomic stemless shoulder arthroplasty and related outcomes: a systematic review

BACKGROUND

The latest generation of shoulder arthroplasty includes canal-sparing respectively stemless designs that have been developed to allow restoration of the glenohumeral center of rotation independently from the shaft, and to avoid stem-related complications. The stemless prosthesis design has also recently been introduced for use in reverse arthroplasty systems.

METHODS

We systematically reviewed the literature for studies of currently available canal-sparing respectively stemless shoulder arthroplasty systems. From the identified series, we recorded the indications, outcome measures, and humeral-sided complications.

RESULTS

We identified 11 studies of canal-sparing respectively stemless anatomic shoulder arthroplasty implants, published between 2010 and 2016. These studies included 929 cases, and had a mean follow-up of 26 months (range, 6 to 72 months). The rates of humeral component-related complications ranged between 0 and 7.9 %. The studies reported only a few isolated cases of complications of the humeral component. Some arthroplasty systems are associated with radiological changes, but without any clinical relevance.

CONCLUSIONS

All of the published studies of canal-sparing respectively stemless shoulder arthroplasty reported promising clinical and radiological outcomes in short to midterm follow-up. Long-term studies are needed to demonstrate the long-term value of these kind of implants.

An unusual presentation of metastatic melanoma in the shoulder

A 72-year-old lady underwent a Copeland hemiarthoplasty of the shoulder for rotator cuff arthropathy with a good functional outcome. Her past medical history included previous management of a malignant melanoma. Several years following arthroplasty surgery, she acutely developed signs and symptoms of prosthetic joint infection. The present case report describes the metastatic spread of malignant melanoma mimicking that of prosthetic sepsis.

Histological evaluation of two designs of shoulder surface replacement implants

AIMS

To assess the extent of osteointegration in two designs of shoulder resurfacing implants. Bony integration to the Copeland cylindrical central stem design and the Epoca RH conical-crown design were compared.

PATIENTS AND METHODS

Implants retrieved from six patients in each group were pair-matched. Mean time to revision surgery of Copeland implants was 37 months (standard deviation (sd) 23; 14 to 72) and Epoca RH 38 months (sd 28; 12 to 84). The mean age of patients investigated was 66 years (sd 4; 59 to 71) and 58 years (sd 17; 31 to 73) in the Copeland and Epoca RH groups respectively. None of these implants were revised for loosening.

RESULTS

Increased osteointegration was measured under the cup in the Copeland implant group with limited bone seen in direct contact with the central stem. Bone adjacent to the Epoca RH implants was more uniform.

CONCLUSION

This difference in the distribution of bone-implant contact and bone formation was attributed to the Epoca implant's conical crown, which is positioned in more dense peripheral bone. The use of a central stem may not be necessary provided there is adequate peripheral fixation within good quality humeral bone.

TAKE HOME MESSAGE

Poor osteointegration of cementless surface replacement shoulder prosthesis may be improved by implant design.

Cementless surface replacement hemiarthroplasty for primary glenohumeral osteoarthritis: results of over 5-year follow-up in patients with or without rotator cuff deficiency

BACKGROUND

Cementless surface replacement hemiarthroplasty (CSRHA) is an established treatment for glenohumeral osteoarthritis; however, studies evaluating its role in arthritis with rotator cuff deficiency are limited. This study reviews the outcomes of CSRHA for glenohumeral osteoarthritis with and without rotator cuff tears.

METHODS

41 CSRHA (Mark III Copeland prosthesis) were performed for glenohumeral osteoarthritis with intact rotator cuffs (n = 21) and cuff-deficient shoulders (n = 20). Patients were assessed using Oxford and Constant questionnaires, patient satisfaction, range of motion measurements and by radiography.

RESULTS

Mean age and follow-up were 75 years and 5.1 years, respectively. Functional gains were significantly higher in patients with intact rotator cuffs compared to cuff-deficient shoulders, with Oxford Shoulder Score improving from 18 to 37.5 and 15 to 27 and forward flexion improved from 60° to 126° and 44° to 77° in each group, respectively. Two patients with deficient cuffs had deficient subscapularis tendons; one of which was dislocated anteriorly.

CONCLUSIONS

CSRHA provides significant improvements in pain and function in patients with glenohumeral osteoarthritis. In patients with deficient cuffs, functional gains are limited, and should be considered in low-demand patients where pain is the primary problem. Caution should be taken in patients with a deficient subscapularis as a result of the risk of dislocation.

Long-term follow-up of the Copeland mark III shoulder resurfacing hemi-arthroplasty

BACKGROUND

Shoulder humeral resurfacing is being performed in increasing numbers. We report the long-term outcome of patients with the Copeland mark III humeral resurfacing hemi-arthroplasty.

METHODS

Ninety-five shoulder hemi-arthroplasties were performed in 85 patients, from 1994 to 2003. Oxford Shoulder Score (OSS) and short form 12 (SF-12) questionnaires were administered.

RESULTS

At 12-year follow-up, 49 patients were alive. The OSS was 35.2 and SF-12 score was 83. There were 3 revision operations and 95% survivorship at 18 years.

CONCLUSION

This prosthesis has a low revision rate with few post-operative complications and good patient-reported outcome in an elderly population.

Periprosthetic humeral fracture after Copeland resurfacing and the role of revision arthroplasty: A report of three cases

Follow-up series of the Copeland resurfacing hemiarthroplasty have reported few postoperative fractures around the prosthesis. We report three cases of periprosthetic fracture around a Copeland resurfacing arthroplasty. Due to prosthetic loosening and tuberosity comminution, all cases were managed with revision shoulder arthroplasty. All patients had good functional outcome and range of movement on early follow-up.

Resurfacing of the humeral head: An analysis of the bone stock and osseous integration under the implant

Cementless-surface-replacement-arthroplasty (CSRA) of the shoulder aims for functional joint restoration with minimal bone loss. Good clinical results have been reported, but due to the radiopaque metal shell no data is available on the structure, osseous integration, and bone stock under the implant. 14 hemi-CSRAs (4 manufacturers) with two geometries (crown [n = 7]/ stem [n = 7] fixation) were retrieved from patients undergoing revision due to glenoidal erosion. Histological sections cutting through the implant centre and bone were analysed. Quantitative histomorphometry evaluated the bone-implant-contact and compared the bone-area to native humeral retrievals (n = 7). The bone-implant-interface was further assessed by scanning-electron-microscopy (SEM) and energy-dispersive-x-ray (EDX). Qualitative histology revealed a reduced and inhomogeneous bone stock. Obvious signs of stress shielding were observed with bone predominantly visible at the stem and implant rim. Quantitative histomorphometry confirmed the significantly reduced bone-area (9.2 ± 3.9% [crown 9.9 ± 4.3%, stem 8.6 ± 3.6%]) compared to native humeri (21.2 ± 9.1%; p < 0.05). Bone-implant-contact was 20.5 ± 5.8% (crown 21.8 ± 6.2%, stem 19.2 ± 5.6%) which was confirmed by SEM and EDX. Altogether, CRSA shows satisfactory bone ingrowth at the interface suggesting sufficient primary stability to allow osseous integration. However, clear signs of stress shielding with an inhomogeneous and reduced bone stock were observed. The impact on the long-term-results is unclear requiring further investigation.

Resurfacing shoulder arthroplasty for the treatment of severe rheumatoid arthritis: outcome in 167 patients from the Danish Shoulder Registry

BACKGROUND AND PURPOSE

There is no consensus on which type of shoulder prosthesis should be used in patients with rheumatoid arthritis (RA). We describe patients with RA who were treated with shoulder replacement, regarding patient-reported outcome, prosthesis survival, and causes of revision, and we compare outcome after resurfacing hemi-arthroplasty (RHA) and stemmed hemi-arthroplasty (SHA).

PATIENTS AND METHODS

We used data from the national Danish Shoulder Arthroplasty Registry and included patients with RA who underwent shoulder arthroplasty in Denmark between 2006 and 2010. Patient-reported outcome was obtained 1-year postoperatively using the Western Ontario Osteoarthritis of the Shoulder index (WOOS), and rates of revision were calculated by checking revisions reported until December 2011. The patient-reported outcome of RHA was compared to that of SHA using regression analysis with adjustment for age, sex, and previous surgery.

RESULTS

During the study period, 167 patients underwent shoulder arthroplasty because of rheumatoid arthritis, 80 (48%) of whom received RHA and 34 (26%) of whom received SHA. 16 patients were treated with total stemmed shoulder arthroplasty (TSA), and 24 were treated with reverse shoulder arthroplasty (rTSA). 130 patients returned a completed questionnaire, and the total mean WOOS score was 63. The cumulative 5-year revision rate was 7%. Most revisions occurred after RHA, with a revision rate of 14%. Mean WOOS score was similar for RHA and for SHA.

INTERPRETATION

This study shows that shoulder arthroplasty, regardless of design, is a good option in terms of reducing pain and improving function in RA patients. The high revision rate in the RHA group suggests that other designs may offer better implant survival. However, this should be confirmed in larger studies.

Stemmed hemiarthroplasty versus resurfacing in primary shoulder osteoarthritis: a single-center retrospective series of 78 patients

INTRODUCTION

Resurfacing shoulder arthroplasty is proposed in primary osteoarthritis of the shoulder. The present study compared resurfacing versus 3rd generation stemmed hemiarthroplasty in terms of survival, functional results and implant positioning effects.

MATERIALS AND METHODS

Seventy eight patients underwent arthroplasty for primary osteoarthritis of the shoulder: 41 by resurfacing and 37 by stemmed hemiarthroplasty. The two populations were comparable on all baseline variables. Minimum follow-up was 2 years. The principal assessment criterion was survivorship with surgical revision as end-point. Secondary criteria were functional results on Constant, quick-DASH, Neer and SSV scores, and implant positioning effects assessed on radiology.

RESULTS

At a mean 44 months' follow-up (range, 24-118 months), there were no significant differences in functional scores. Radiologic analysis found greater varus positioning and lateral offset of the humeral head in resurfacing compared with stemmed hemiarthroplasty (128° vs 138°, P<0.01; 6.5 ± 2 vs 4.6 ± 1.6mm, P<0.01). Survivorship without revision was significantly poorer in resurfacing, with 4 revision procedures for glenoid wear (9.8%), versus none in hemiarthroplasty (P=0.02). There was no correlation between humeral head size, positioning or lateral offset and revision.

CONCLUSION

Revision-free survival was significantly lower in resurfacing than in hemiarthroplasty. Greater humeral head size may increase lateral offset, accelerating glenoid wear. Down-sizing the humeral head in resurfacing procedures might limit these complications.

LEVEL OF EVIDENCE

Level III; case-control study.

Results of cementless humeral head resurfacing with cemented glenoid components

PURPOSE

The aim of this study was to analyse the short- and medium-term clinical and radiographic results of cementless humeral head resurfacing in combination with a cemented glenoid component.

METHODS

Thirty-five patients with a mean age of 65 years (range 42-84) and a mean follow-up of three years (two to six) were followed up. The Constant score with its subgroups as well as shoulder motions and complications were recorded. Radiographs in two planes were analysed for loosening of the components.

RESULTS

Mean Constant score improved from 29 points (6-63) to 70 points (41-89; p < 0.001). Mean shoulder flexion increased from 89° (20-170) to 158° (100-180) and mean external rotation from 10° (-10-30) to 39° (10-80). Satisfaction rate was 94 % at final follow-up. None of the components was found to be loose. There were three neurological complications, probably related to increased forces on the humeral head retractor during glenoid preparation. Two of them resolved completely; in one patient hyposensitivity remained.

CONCLUSION

Cementless humeral surface replacement arthroplasty in combination with a cemented glenoid component leads to an overall satisfactory clinical outcome. However, the high rate of neurological complications found in this study, probably related to difficult glenoid exposure, led us to discontinue this implant configuration.

Stress-shielding induced bone remodeling in cementless shoulder resurfacing arthroplasty: a finite element analysis and in vivo results

Cementless surface replacement arthroplasty (CSRA) of the shoulder was designed to preserve the individual anatomy and humeral bone stock. A matter of concern in resurfacing implants remains the stress shielding and bone remodeling processes. The bone remodeling processes of two different CSRA fixation designs, conical-crown (Epoca RH) and central-stem (Copeland), were studied by three-dimensional (3-D) finite element analysis (FEA) as well as evaluation of contact radiographs from human CSRA retrievals. FEA included one native humerus model with a normal and one with a reduced bone stock quality. Compressive strains were evaluated before and after virtual CSRA implantation and the results were then compared to the bone remodeling and stress-shielding pattern of eight human CSRA retrievals (Epoca RH n=4 and Copeland n=4). FEA revealed for both bone stock models increased compressive strains at the stem and outer implant rim for both CSRA designs indicating an increased bone formation at those locations. Unloading of the bone was seen for both designs under the central implant shell (conical-crown 50-85%, central-stem 31-93%) indicating high bone resorption. Those effects appeared more pronounced for the reduced than for the normal bone stock model. The assumptions of the FEA were confirmed in the CSRA retrieval analysis which showed bone apposition at the outer implant rim and stems with highly reduced bone stock below the central implant shell. Overall, clear signs of stress shielding were observed for both CSRAs designs in the in vitro FEA and human retrieval analysis. Especially in the central part of both implant designs the bone stock was highly resorbed. The impact of these bone remodeling processes on the clinical outcome as well as long-term stability requires further evaluation.

Resurfacing hemiarthroplasty compared to stemmed hemiarthroplasty for glenohumeral osteoarthritis: a randomised clinical trial

PURPOSE

The aim of this study was to conduct a randomised, clinical trial comparing stemmed hemiarthroplasty and resurfacing hemiarthroplasty in the treatment of glenohumeral osteoarthritis.

METHODS

A total of 40 shoulders (35 patients) were randomised to stemmed hemiarthroplasty or resurfacing hemiarthroplasty and evaluated three and 12 months postoperatively using the Constant-Murley score (CMS) and Western Ontario Osteoarthritis of the Shoulder (WOOS) index.

RESULTS

There were no statistically significant differences in age, gender or pre-operative scores except for WOOS at baseline. Two patients were lost to follow-up. Significant improvements in CMS and WOOS were observed at one year after both arthroplasty designs. At one year, the mean CMS was 48.9 (range 6-80) after resurfacing hemiarthroplasty and 59.1 (range 0-88) after stemmed hemiarthroplasty {mean difference 10.2 [95 % confidence interval (CI) -3.3 to 23.6], P = 0.14}. The mean WOOS was 59.2 (range 5.2-100.0) and 79.4 (range 12.8-98.6), respectively [mean difference 20.2 (95 % CI 3.4-36.9), P = 0.02]. No major complications occurred and there were no revisions.

CONCLUSIONS

The effects of resurfacing hemiarthroplasty tended to be inferior to those of stemmed hemiarthroplasty. It is unclear whether this reflects a real difference in effect or baseline differences due to the limited number of randomised patients. We suggest there is a need for a larger, more definitive trial.

Outcome, revision rate and indication for revision following resurfacing hemiarthroplasty for osteoarthritis of the shoulder: 837 operations reported to the Danish Shoulder Arthroplasty Registry

In this study, we evaluated patient-reported outcomes, the rate of revision and the indications for revision following resurfacing hemiarthroplasty of the shoulder in patients with osteoarthritis. All patients with osteoarthritis who underwent primary resurfacing hemiarthroplasty and reported to the Danish Shoulder Arthroplasty Registry (DSR), between January 2006 and December 2010 were included. There were 772 patients (837 arthroplasties) in the study. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index was used to evaluate patient-reported outcome 12 months (10 to 14) post-operatively. The rates of revision were calculated from the revisions reported to the DSR up to December 2011 and by checking deaths with the Danish National Register of Persons. A complete questionnaire was returned by 688 patients (82.2%). The mean WOOS was 67 (0 to 100). A total of 63 hemiarthroplasties (7.5%) required revision; the cumulative five-year rate of revision was 9.9%. Patients aged < 55 years had a statistically significant inferior WOOS score, which exceeded the minimal clinically important difference, compared with older patients (mean difference 14.2 (8.8; 95% CI 19.6; p < 0.001), but with no increased risk of revision. There was no significant difference in the mean WOOS or the risk of revision between designs of resurfacing hemiarthroplasty.

Outcome and risk of revision following shoulder replacement in patients with glenohumeral osteoarthritis

This thesis includes four studies focusing on the functional outcome, shoulder-specific quality of life and risk of revision following shoulder replacement in patients with glenohumeral osteoarthritis without symptomatic rotator cuff pathology. The Danish version of WOOS, translated according to international standardized guidelines, had substantial psychometric properties comparable to the original version. It is recommendable to use WOOS in the evaluation of patients with glenohumeral osteoarthritis treated with shoulder replacement. Data from DSR showed that the shoulder specific quality of life following total shoulder arthroplasty was superior to that of hemiarthroplasty (resurfacing hemiarthroplasty and stemmed hemiarthroplasty). The difference between stemmed hemiarthroplasty and resurfacing hemiarthroplasty was small and did not exceed the minimal clinically important difference. The revision rate following resurfacing hemiarthroplasty was surprisingly high compared with previous reports but there were no statistical significant differences in revision rate between arthroplasty designs. The shoulder specific quality of life and revision rate in patients under the age of 55 was worrying. The use of resurfacing hemiarthroplasty has relied on the results from case series only. The efficacy in the treatment of glenohumeral osteoarthritis has been promising but the CMS found in the randomized clinical trial indicate that the functional outcome may be inferior to that of stemmed hemiarthroplasty and less favourable than previously reported. However, the limited number of patients may have influenced the results and a larger definitive RCT is needed.Shoulder replacement is relevant and effective in the treatment of glenohumeral osteoarthritis; however, resurfacing hemiarthroplasty was associated with a poorer outcome and a higher risk of revision than previously assumed especially in patients under the age of 55. Based on data from this thesis, and based on existing knowledge, it seems like total shoulder arthroplasty should be preferred in the treatment of glenohumeral osteoarthritis. Shoulder replacement is rarely indicated in younger patients where other treatment options (e.g., physiotherapy; intraarticular injections of hyaluronate; and joint preserving surgery) should be considered until the efficacy of shoulder replacement has been more thoroughly documented.

Patient-reported outcome and risk of revision after shoulder replacement for osteoarthritis. 1,209 cases from the Danish Shoulder Arthroplasty Registry, 2006-2010

PURPOSE

We used patient-reported outcome and risk of revision to compare hemiarthroplasty (HA) with total shoulder arthroplasty (TSA) and stemmed hemiarthroplasty (SHA) with resurfacing hemiarthroplasty (RHA) in patients with glenohumeral osteoarthritis.

PATIENTS AND METHODS

We included all patients reported to the Danish Shoulder Arthroplasty Registry (DSR) between January 2006 and December 2010. 1,209 arthroplasties in 1,109 patients were eligible. Western Ontario Osteoarthritis of the Shoulder index (WOOS) was used to evaluate patient-reported outcome 1 year postoperatively. For simplicity of presentation, the raw scores were converted to a percentage of the maximum score. Revision rates were calculated by checking reported revisions to the DSR until December 2011. WOOS and risk of revision were adjusted for age, sex, previous surgery, and type of osteoarthritis.

RESULTS

There were 113 TSAs and 1096 HAs (837 RHAs and 259 SHAs). Patients treated with TSA generally had a better WOOS, exceeding the predefined minimal clinically important difference, at 1 year (mean difference 10, p < 0.001). RHA had a better WOOS than SHA (mean difference 5, p = 0.02), but the difference did not exceed the minimal clinically important difference. There were no statistically significant differences in revision rate or in adjusted risk of revision between any of the groups.

INTERPRETATION

Our results are in accordance with the results from other national shoulder registries and the results published in systematic reviews favoring TSA in the treatment of glenohumeral osteoarthritis. Nonetheless, this registry study had certain limitations and the results should be interpreted carefully.

Mid-term results of Copeland shoulder cementless surface replacement arthroplasty from an independent centre

BACKGROUND

The present study reports our experience of Copeland shoulder cementless surface replacement arthroplasty (CSRA) and whether glenoid microfracture influences the progression of glenoid erosion.

METHODS

One-hundred-and-twelve CSRAs were performed in 101 patients between 2002 and 2007. Eighty-three patients were alive at the median follow-up time of 72 months (range 9 to 121 months; interquartile range 46 to 93 months). Assessment included an Oxford shoulder score (OSS), patient satisfaction score and plain radiographs.

RESULTS

The mean (range) OSS was 27 (7 to 48) and 64 of 73 (87.7%) patients were 'very satisfied' or 'satisfied' with their shoulder. Twenty-three (20.5%) shoulders had over 2 mm of glenoid erosion. Microfracture was performed in 43 of 112 shoulders (38.4%) and did not influence the progression of glenoid erosion. Further surgery was performed in 27 (24.1%) shoulders, including 15 revisions, eight arthrolyses and four subacromial decompressions. Revision to total shoulder arthroplasty was performed in 14 : 10 for glenoid erosion; one each for loosening, periprosthetic fracture, deep infection, and chronic pain. One was revised to reverse arthroplasty for chronic pain.

CONCLUSIONS

CSRA performed in an independent centre reproduces the functional outcomes reported by the designer. Glenoid erosion, however, was a common occurrence and the main cause of revision - microfracture did not influence its progression.

The influence of rotator cuff pathology on functional outcome in total shoulder replacement

Introduction:

Total shoulder replacement (TSR) is a reliable treatment for glenohumeral osteoarthritis. In addition to proper component orientation, successful arthroplasty requires accurate restoration of soft tissues forces around the joint to maximize function. We hypothesized that pathological changes within the rotator cuff on preoperative magnetic resonance imaging (MRI) adversely affect the functional outcome following TSR.

Materials and Methods:

A retrospective analysis of case notes and MRI of patients undergoing TSR for primary glenohumeral osteoarthritis over a 4-year period was performed. Patients were divided into three groups based upon their preoperative MRI findings: (1) normal rotator cuff, (2) the presence of tendonopathy within the rotator cuff, or (3) the presence of a partial thickness rotator cuff tear. Intra-operatively tendonopathy was addressed with debridement and partial thickness tears with repair. Functional outcome was assessed with the Oxford Shoulder Score (OSS), and quick disabilities of the arm, shoulder and hand score (quick-DASH).

Results:

We had a full dataset of complete case-notes, PACS images, and patient reported outcome measures available for 43 patients, 15 in group 1, 14 in group 2, and 14 in group 3. Quick-DASH and OSS were calculated at a minimum of 24 months following surgery. There was no statistically significant difference between the results obtained between the three groups of either the OSS (P = 0.45), or quick-DASH (P = 0.46).

Conclusions:

TSR is an efficacious treatment option for patients with primary glenohumeral osteoarthritis in the medium term, even in the presence of rotator cuff tendonopathy or partial tearing. Minor changes within the cuff do not significantly affect functional outcome following TSR.

Clinical and radiographic mid-term outcomes after shoulder resurfacing in patients aged 50 years old or younger

PURPOSE

Humeral resurfacing is a treatment option to conventional shoulder arthroplasty, conferring the advantages to preserve the bone stock and the normal joint geometry. Aim of the current study was to report clinical and radiographic mid-term outcomes in a population of 60 patients, aged 50 years or younger, who underwent shoulder resurfacing in osteoarthritis.

METHODS

The mean age was 48 ± 8.4, 36 were male and 24 female, dominant arm in 43 cases. Glenoid arthritis was treated in 36 cases (60 %) using a meniscus allograft in 22 cases, biologic patch in 4 cases and microfractures in 10 cases. Clinical and radiographic assessment was performed with Constant-Murley score and standard X-ray.

RESULTS

At an average follow-up of 44 months, the mean values of the constant score increased of 30 points (p < 0.05), the pain decreased of 4.56 points (p < 0.05) and the Simple Shoulder Test increased of 4.3 points (p < 0.05). We found lower scores (p > 0.05) in 9 patients (15 %) treated for glenoid arthritis using homologous meniscus (7 cases) and biologic patch (2 cases). A significant narrowing of joint space (5.92 mm postoperative versus 1.65 mm at 37 months) (p < 0.05) was found in the 22 cases treated with meniscus interposition. In 4 cases with type A2 preoperative glenoid morphology and in 9 cases type B1, we registered significantly lower scores compared with the overall study population (p < 0.01). Five unsatisfied patients (7 %), underwent to meniscus removal and glenoid reaming in 3 cases and conversion in total shoulder arthroplasty in 2 cases.

CONCLUSIONS

Resurfacing arthroplasty is an effective device in young patients with advanced glenohumeral arthropathy; however, the high rate of postoperative glenoid erosion and the failure of biologic allograft lead us to consider glenoid replacement as the best option to improve clinical outcomes.