Proximal humeral osteolysis and glenoid radiolucent lines in an anatomic shoulder arthroplasty: a comparison of a ceramic and a metal humeral head component

Hemiarthroplasty in young patients

Aims

The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids.

Methods

Intact right cadaveric shoulders from donors aged between 50 and 65 years were assigned to a ceramic group (n = 8, four male cadavers) and a metal group (n = 9, four male cadavers). A dedicated shoulder wear simulator was used to simulate daily activity by replicating the relevant joint motion and loading profiles. During testing, the joint was kept lubricated with diluted calf serum at room temperature. Each test of wear was performed for 500,000 cycles at 1.2 Hz. At intervals of 125,000 cycles, micro-CT scans of each glenoid were taken to characterize and quantify glenoid wear by calculating the change in the thickness of its articular cartilage.

Results

At the completion of the wear test, the total thickness of the cartilage had significantly decreased in both the ceramic and metal groups, by 27% (p = 0.019) and 29% (p = 0.008), respectively. However, the differences between the two were not significant (p = 0.606) and the patterns of wear in the specimens were unpredictable. No significant correlation was found between cartilage wear and various factors, including age, sex, the size of the humeral head, joint mismatch, the thickness of the native cartilage, and the surface roughness (all p > 0.05).

Conclusion

Although ceramic has better tribological properties than metal, we did not find evidence that its use in hemiarthroplasty of the shoulder in patients with healthy cartilage is a better alternative than conventional metal humeral heads.

Influence of humeral position of the Affinis Short stemless shoulder arthroplasty system on long-term survival and clinical outcome

BACKGROUND

The purpose of this study was to evaluate the influence of humeral position of the Affinis Short implant in stemless anatomic total shoulder arthroplasties (STSAs) on clinical and radiologic results and mid- to long-term survival in the treatment of primary osteoarthritis (OA) of the shoulder.

METHODS

Eighty patients treated with a stemless shoulder arthroplasty for OA of the shoulder were evaluated with a mean follow-up of 92 ± 14 months (range 69-116 months) by the Constant Score (CS), Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and active range of motion (ROM). Radiographic assessment for bone adaptations and humeral implant position was performed by plain radiographs. Comparison of the pre- and postoperative centers of rotation (CORs) was used to assess the restoration of the geometry of the humeral head. The appraisal of proper humeral component positioning was correlated with the functional outcomes. A Kaplan-Meier analysis was performed to investigate the influence of humeral implant position compared to survival time. Complications were noted.

RESULTS

The ROM (P < .001), CS (P < .001), and DASH scores (P < .001) showed significant improvements after surgery for the entire series. The COR restoration was anatomic in 75% (n = 60) of all implants and in 25% (n = 20) nonanatomic implants (pre- and postoperative COR deviation of 2.7 ± 1.8 mm vs. 5.1 ± 3.2 mm, P = .0380). The humeral component position did not affect the functional outcome whereas the 10-year unadjusted cumulative survival rate for the anatomic group was significantly higher in comparison with the nonanatomic group (96.7% vs. 75%, P = .002). The radiologic evaluation revealed minor periprosthetic bone adaptions in various forms without clinical significance or further intervention. No revision was necessary because of a failed fixation of the stemless humeral component.

CONCLUSIONS

Regarding the treatment of primary OA of the shoulder, STSA shows excellent long-term survival and clinical outcomes. In particular, STSA implants are able to restore the geometry of the humeral head. Nonanatomic reconstruction may influence the survival over the long term in different pathways. Further studies are necessary to elucidate the effect of humeral component position in STSA on function, pain, and implant survival rates.

Stress shielding of the proximal humerus in stemless anatomic total shoulder arthroplasty

Background

This study aimed to assess the radiographic proximal humerus bony adaptations to stress shielding and associated clinical outcomes following stemless total shoulder arthroplasty.

Methods

A retrospective review of all patients who underwent stemless total shoulder arthroplasty surgery at our centre from 2010 to 2020 was performed.

Results

In total, 115 stemless total shoulder arthroplasty utilising a single implant design with a minimum one-year follow-up were identified over a 10-year period. The median follow-up was 3.5 years (range: 1-8.9 years). Evidence of stress shielding was observed in 20 cases (17%), (9 mild (8%), 0 moderate (0%), 11 severe (9%). No significant differences were seen between stress shielding and gender, body mass index, post-operative range-of-motion, patient satisfaction, or Oxford shoulder score. No significant differences were seen between the operative technique and stress shielding. No cases had evidence of humeral lucency. In total, 24 cases (21%) had evidence of glenoid lucency of Lazarus grade 0-3. No cases had Lazarus grades 4 or 5. There was no association between stress shielding and humeral lucency, glenoid lucency, or revision procedure.

Discussion

Stress shielding in this study occurred at lower rates than anticipated following stemless total shoulder arthroplasty and was not associated with radiographic evidence of lucency, revision procedures, or adverse effect on clinical outcome measures.

Recent Advances in the Design and Application of Shoulder Arthroplasty Implant Systems and Their Impact on Clinical Outcomes: A Comprehensive Review

Purpose of Review

This narrative review comprehensively aims to analyze recent advancements in shoulder arthroplasty, focusing on implant systems and their impact on patient outcomes. The purpose is to provide a nuanced understanding of the evolving landscape in shoulder arthroplasty, incorporating scientific, regulatory, and ethical dimensions.

Recent Findings

The review synthesizes recent literature on stemless implants, augmented glenoid components, inlay vs onlay configurations, convertible stems, and associated complications. Notable findings include improved patient-reported outcomes with stemless implants, variations in outcomes between inlay and onlay configurations, and the potential advantages of convertible stems. Additionally, the regulatory landscape, particularly the FDA's 510(k) pathway, is explored alongside ethical considerations, emphasizing the need for standardized international regulations.

Summary

Recent innovations in shoulder arthroplasty showcase promising advancements, with stemless implants demonstrating improved patient outcomes. The review underscores the necessity for ongoing research to address unresolved aspects and highlights the importance of a standardized regulatory framework to ensure patient safety globally. The synthesis of recent findings contributes to a comprehensive understanding of the current state of shoulder arthroplasty, guiding future research and clinical practices.

Clinical results and computed tomography analysis of intuitive shoulder arthroplasty (ISA) stemless at a minimum follow-up of 2 years

BACKGROUND

The utilization of stemless anatomic total shoulder arthroplasty is on the rise. Epiphyseal fixation leads to radiological bone remodeling, which has been reported to exceed 40% in certain studies series. The aim of this study was to present the clinical and radiological outcomes of a stemless implant with asymmetric central epiphyseal fixation at an average follow-up of 31 months.

MATERIALS AND METHODS

This retrospective multicenter study examined prospective data of patients undergoing total anatomic arthroplasty with intuitive shoulder arthroplasty Stemless implant and followed up at least 2 years. Clinical assessment included preoperative and final follow-up measurements of active range of motion, Constant score, and Subjective Shoulder Value. Anatomical epiphyseal reconstruction and bone remodeling at the 2-year follow-up were assessed by standardized computed tomography scanner (CT scan). Statistical analysis employed unpaired Student's t-test or chi-squared test depending on the variable type, conducted using EasyMedStat software (version 3.22; www.easymedstat.com).

RESULTS

Fifty patients (mean age 68 years, 62% females) were enrolled, with an average follow-up of 31 months (24-44). Primary osteoarthritis (68%) with type A glenoid (78%) was the prevailing indication. The mean Constant score and Subjective Shoulder Value improved significantly from 38 ± 11 to 76 ± 11 (P < .001) and from 31% ± 16 to 88% ± 15 (P < .001) respectively at the last follow-up. Forward elevation, external rotation, and internal rotation range of motion increased by 39° ± 42, 28° ± 21 and 3,2 ± 2,5 points respectively, surpassing the Minimally Clinically Important Difference after total shoulder arthroplasty. No revisions were necessary. CT scans identified 30% osteolysis in the posterior-medial calcar region, devoid of clinical repercussions. No risk factors were associated with bone osteolysis.

CONCLUSIONS

At an average follow-up of 31 months, intuitive shoulder arthroplasty Stemless implant provided favorable clinical results. CT analysis revealed osteolysis-like remodeling in the posterior-medial zone of the calcar (30%), without decline in clinical outcomes and revisions. Long-term follow-up studies are mandated to evaluate whether osteolysis is associated with negative consequences.

Revision rate in metal compared to ceramic humeral head total shoulder arthroplasty and hemiarthroplasty

Aims

Metal and ceramic humeral head bearing surfaces are available choices in anatomical shoulder arthroplasties. Wear studies have shown superior performance of ceramic heads, however comparison of clinical outcomes according to bearing surface in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) is limited. This study aimed to compare the rates of revision and reoperation following metal and ceramic humeral head TSA and HA using data from the National Joint Registry (NJR), which collects data from England, Wales, Northern Ireland, Isle of Man and the States of Guernsey.

Methods

NJR shoulder arthroplasty records were linked to Hospital Episode Statistics and the National Mortality Register. TSA and HA performed for osteoarthritis (OA) in patients with an intact rotator cuff were included. Metal and ceramic humeral head prostheses were matched within separate TSA and HA groups using propensity scores based on 12 and 11 characteristics, respectively. The primary outcome was time to first revision and the secondary outcome was non-revision reoperation.

Results

A total of 4,799 TSAs (3,578 metal, 1,221 ceramic) and 1,363 HAs (1,020 metal, 343 ceramic) were included. The rate of revision was higher for metal compared with ceramic TSA, hazard ratio (HR) 3.31 (95% confidence interval (CI) 1.67 to 6.58). At eight years, prosthesis survival for ceramic TSA was 98.7% (95% CI 97.3 to 99.4) compared with 96.4% (95% CI 95.2 to 97.3) for metal TSA. The majority of revision TSAs were for cuff insufficiency or instability/dislocation. There was no significant difference in the revision rate for ceramic compared with metal head HA (HR 1.33 (95% CI 0.76 to 2.34)). For ceramic HA, eight-year prosthetic survival was 92.8% (95% CI 86.9 to 96.1), compared with 91.6% (95% CI 89.3 to 93.5) for metal HA. The majority of revision HAs were for cuff failure.

Conclusion

The rate of all-cause revision was higher following metal compared with ceramic humeral head TSA in patients with OA and an intact rotator cuff. There was no difference in the revision rate for HA according to bearing surface.

Encouraging outcomes of stemless ceramic head anatomic shoulder arthroplasty in severe primary osteoarthritis (Walch type B glenoids)

Background: We report the radiological and functional outcomes at five years in patients with severe osteoarthritis of the glenohumeral joint and a Walch type B glenoid who have undergone stemless anatomic total shoulder replacement. Methods: A retrospective analysis of case notes, computed tomography scans and plain radiographs of patients undergoing anatomic total shoulder replacement for primary glenohumeral osteoarthritis were performed. Patients were grouped by the severity of their osteoarthritis using the modified Walch classification, glenoid retroversion and posterior humeral head subluxation. An evaluation was made using modern planning software. Functional outcomes were assessed using the American shoulder and elbow surgeons score, shoulder pain and disability index and visual analogue scale. Annual Lazarus scores were reviewed as regard to glenoid loosening. Results: Thirty patients were reviewed at 5 years. Analysis of all patient-reported outcome measures demonstrated significant improvement at 5-year review, American shoulder and elbow surgeons (p = <0.0001), shoulder pain and disability index (p = 0.0001), visual analogue scale (p = 0.0001). Radiological associations between Walch scores and Lazarus scores were not statistically significant (p = 0.1251) at 5 years. There were no associations between features of glenohumeral osteoarthritis and patient-reported outcome measures. Discussion: The severity of osteoarthritis did not show any association with glenoid component survivorship or with patient-reported outcome measures at 5 years review. Level of evidence: IV.

Pathogenesis, Evaluation, and Management of Osteolysis After Total Shoulder Arthroplasty

Radiographic osteolysis after total shoulder arthroplasty (TSA) remains a challenging clinical entity, as it may not initially manifest clinically apparent symptoms but can lead to clinically important complications, such as aseptic loosening. A thorough consideration of medical history and physical examination is essential to rule out other causes of symptomatic TSA—namely, periprosthetic joint infection—as symptoms often progress to vague pain or discomfort due to subtle component loosening. Once confirmed, nonoperative treatment of osteolysis should first be pursued given the potential to avoid surgery-associated risks. If needed, the current surgical options include glenoid polyethylene revision and conversion to reverse shoulder arthroplasty. The current article provides a comprehensive review of the evaluation and management of osteolysis after TSA through an evidence-based discussion of current concepts.

Proximal humeral bone loss in stemless shoulder arthroplasty: potential factors influencing bone loss and a new classification system

INTRODUCTION

Proximal humeral bone loss in total shoulder arthroplasty (TSA) is more frequent than in hemiarthroplasty. Factors such as age, gender, inclination angle, and radiolucent lines may also contribute. Additionally, current bone loss grading systems are often not sensitive enough to detect slight bone changes, especially at the medial calcar where bone loss is commonly observed. This study uses a new, more detailed bone loss grading system to evaluate factors that could influence bone loss at the proximal humerus.

MATERIALS AND METHODS

In this single-center prospective study, patients underwent hemiarthroplasty or TSA with an anatomic stemless prosthesis. Bone loss was measured at the proximal humerus using the new grading system. The effect of treatment type, age, gender, radiolucent lines, and inclination angle on bone loss was evaluated. The Constant-Murley score of patients was assessed and complications recorded.

RESULTS

Ninety-one shoulders were available for the final follow-up examination at a median of 85.0 months (range 82.6-121.1 months). Bone loss was found at the proximal humerus in approximately one-third of shoulders, and significantly more shoulders had bone loss in TSA than in hemiarthroplasty (P = 0.03). However, this difference was no longer significant after stratifying by gender and age (P > 0.05). Bone loss significantly correlated with gender (P = 0.03) but not with treatment type, radiolucent lines, and the postoperative inclination angle (P > 0.05). Most Constant-Murley score components did not differ significantly between shoulders with and without bone loss (P > 0.05). Lastly, six complications and four revisions were reported.

CONCLUSIONS

Results showed gender had the greatest influence on bone loss after stemless shoulder arthroplasty. Furthermore, both patients with or without bone loss can expect similar clinical outcomes with the stemless prosthesis used in this study. Lastly, the new grading system is simple and straightforward to use.

Innovations in Shoulder Arthroplasty

Innovations currently available with anatomic total shoulder arthroplasty include shorter stem designs and augmented/inset/inlay glenoid components. Regarding reverse shoulder arthroplasty (RSA), metal augmentation, including custom augments, on both the glenoid and humeral side have expanded indications in cases of bone loss. In the setting of revision arthroplasty, humeral options include convertible stems and newer tools to improve humeral implant removal. New strategies for treatment and surgical techniques have been developed for recalcitrant shoulder instability, acromial fractures, and infections after RSA. Finally, computer planning, navigation, PSI, and augmented reality are imaging options now available that have redefined preoperative planning and indications as well intraoperative component placement. This review covers many of the innovations in the realm of shoulder arthroplasty.

The Definition of Periprosthetic Osteolysis in Shoulder Arthroplasty: A Systematic Review of Grading Schemes and Criteria

BACKGROUND

Periprosthetic osteolysis is a known complication after shoulder arthroplasty that may lead to implant loosening and revision surgery. To date, there is no consensus in the shoulder arthroplasty literature regarding the definition of osteolysis or the grading criteria, thus making it difficult to quantify and compare outcomes involving this complication. The purpose of this study was to perform a systematic review of the literature to assess how periprosthetic osteolysis in shoulder arthroplasty is defined and evaluated radiographically.

METHODS

A systematic review of MEDLINE, Scopus, Cochrane, and CINAHL was performed in August 2021 for studies that provided a definition and/or grading criteria for osteolysis in shoulder arthroplasty. Only studies with a minimum of 2 years of radiographic follow-up were included.

RESULTS

Thirty-four articles met the inclusion criteria. After consolidating studies by the same primary author that included the same grading criteria, 29 studies were examined for their definition and grading criteria for osteolysis. Of these, 19 (65.5%) evaluated osteolysis surrounding the glenoid and 18 (62.1%) evaluated osteolysis surrounding the humerus. There was considerable heterogeneity in the systems used to grade periprosthetic osteolysis surrounding the glenoid, whereas humeral periprosthetic osteolysis was often categorized via visualization into binary or categorical groups (e.g., presence versus absence; mild, moderate, or severe; partial versus complete). Four studies (13.8%) provided novel measurements for assessing either glenoid or humeral osteolysis.

CONCLUSIONS

Considerable heterogeneity exists in the assessment and grading of periprosthetic osteolysis in shoulder arthroplasty. The most common grading systems were binary and used qualitative visual interpretation, making them relatively subjective and prone to bias. Quantitative measurements of osteolysis were infrequently utilized. A standardized method of assessing osteolysis would be of value to facilitate communication and research efforts.

Revision Shoulder Hemiarthroplasty and Total Shoulder Arthroplasty A Systematic Review and Meta-Analysis

The number of shoulder replacements performed each year continues to increase, and the need for revision replacements has grown accordingly. The outcome of a revision replacement may influence which primary implant is selected and the timing of primary surgery, particularly in younger patients. The aim of this study was to establish the expected improvement in shoulder function and implant survival following revision of a hemiarthroplasty and revision of an anatomical total shoulder arthroplasty (TSA). A systematic review and meta-analysis were performed of all studies reporting shoulder scores or implant survival following revision hemiarthroplasty or revision TSA. MEDLINE, EMBASE, CENTRAL, The Cochrane Database of Systematic Reviews and National Joint Registry reports were searched. 15 studies were included, reporting on 593 revision anatomical shoulder replacements. There was large variation in the magnitude of improvement in shoulder scores following revision surgery. Over 80% of revision replacements last 5 years and over 70% last 10 years. There was no significant difference in shoulder scores or implant survival according to the type of primary implant. The belief that revision of a shoulder hemiarthroplasty may lead to improved outcomes compared to revision of a TSA is not supported by the current literature.

Shoulder Replacement in the Elderly with Anatomic versus Reverse Total Prosthesis? A Prospective 2-Year Follow-Up Study

Background: In older patients requiring a total shoulder replacement (TSR) and with an intact rotator cuff, there is currently uncertainty on whether an anatomic TSR (aTSR) or a reverse TSR (rTSR) is best for the patient. This comparison study of same-aged patients aims to assess clinical and radiological outcomes of older patients (≥75 years) who received either an aTSR or an rTSR. Methods: Consecutive patients with a minimum age of 75 years who received an aTSR (n = 44) or rTSR (n = 51) were prospectively studied. Pre- and post-operative clinical evaluations included the ASES score, Constant score, SPADI score, DASH score, range of motion (ROM) and pain and patient satisfaction for a follow-up of 2 years. Radiological assessment identified glenoid and humeral component osteolysis, including notching with an rTSR. Results: We found postoperative improvement for ROM and all clinical assessment scores for both groups. There were significantly better patient reported outcome scores (PROMs) in the aTSR group compared with the rTSR patients (p < 0.001). Both groups had only minor osteolysis on radiographs. No revisions were required in either group. The main complications were scapular stress fractures for the rTSR (n = 11) patients and acromioclavicular joint pain for both groups (aTSR = 2; rTSR = 6). Conclusions: This study of older patients (≥75 years) demonstrated that an aTSR for a patient with good rotator cuff muscles can lead to a better clinical outcome and less early complications than an rTSR. Level of evidence: Level II—prospective cohort study.

Mid-term outcomes of a stemless ceramic head anatomic total shoulder replacement

Background

In an anatomic shoulder replacement (aTSR) good results have been reported with the use of a stemless humeral prosthesis. In vitro a ceramic articulation with polyethylene has been shown to produce less polyethylene wear particles than with metal. This study aims to evaluate clinical and radiographic results of a stemless aTSR with a ceramic head articulating with a polyethylene glenoid component, with mid-term follow-up.

Methods

All patients (n = 92) in this prospective study had an aTSR utilizing a stemless humeral component with a ceramic head and a cemented double pegged cemented polyethylene glenoid component for glenohumeral osteoarthritis. Pre- and postoperative clinical evaluations at 2 years were performed using the ASES score, Constant score, SPADI score, DASH score, VAS pain score, patient satisfaction and range of motion. There was a 5-year evaluation of SPADI, ASES, pain, and satisfaction, plus radiographic assessment of glenoid component radiolucent lines and humeral osteolysis.

Results

Seventy-four cases (68.1 ± 7.1 years) had a five-year follow-up and demonstrated active elevation improvement from 91.3° preoperatively to 151.1° (p < 0.001). Further improvement was identified with the ASES from 41.6 to 94.3, the SPADI from 62.9 to 4.3, VAS pain from 5.6 to 0.4 (0–10), and satisfaction levels were at 96%. Sixty-two cases had no glenoid radiolucent lines with a maximum Lazarus score of 2 in one patient. Constant scores, available up to 2 years, improved significantly from 30.3 to 77.9 (p < 0.001). There was one case that required revision for glenoid loosening.

Conclusions

Overall, the 5-year results of this ceramic head prosthesis demonstrated good radiographic and clinical outcomes.

Trial registration

ACTRN12613001183774. Registered: 29 October 2013 - Retrospectively registered.

Australian New Zealand Clinical Trials Registry (ANZCTR).

Prosthetic Bearing Surfaces in Anatomic and Reverse Total Shoulder Arthroplasty

Total shoulder arthroplasty (TSA) and reverse TSA have provided an effective treatment for glenohumeral osteoarthritis; however, longevity of the procedure may be limited by osteolysis and polyethylene wear. In TSA, glenoid component failure occurs through several mechanisms, the most common being aseptic loosening and polyethylene wear. Newer bearing surfaces such as highly cross-linked ultra-high-molecular-weight polyethylene, vitamin E processing, ceramic heads, and pyrolytic carbon surfaces have shown improved wear characteristics in biomechanical and some early clinical studies. The purpose of this review is to provide a historical perspective and current state of the art of bearing surface technology in anatomic and reverse TSA.

Results of stemless shoulder arthroplasty: a systematic review and meta-analysis

Stemless shoulder arthroplasty relies solely on cementless metaphyseal fixation and is designed to avoid stem-related problem such as intraoperative fractures, loosening, stress shielding or stress-risers for periprosthetic fractures.

Many designs are currently on the market, although only six anatomic and two reverse arthroplasty designs have results published with a minimum of two-year follow-up.

Compared to stemmed designs, clinical outcome is equally good using stemless designs in the short and medium-term follow-up, which is also the case for overall complication and revision rates.

Intraoperative fracture rate is lower in stemless compared to stemmed designs, most likely due to the absence of intramedullary preparation and of the implantation of a stem.

Radiologic abnormalities around the humeral implant are less frequent compared to stemmed implants, possibly related to the closer resemblance to native anatomy.

Between stemless implants, several significant differences were found in terms of clinical outcome, complication and revision rates, although the level of evidence is low with high study heterogeneity; therefore, firm conclusions could not be drawn.

There is a need for well-designed long-term randomized trials with sufficient power in order to assess the superiority of stemless over conventional arthroplasty, and of one design over another.

Cite this article: EFORT Open Rev 2021;6:35-49. DOI: 10.1302/2058-5241.6.200067

The glenoid and humeral head in shoulder osteoarthritis: A comprehensive review

The key management of glenohumeral osteoarthritis is shoulder arthroplasty which aims to reduce pain and restore full shoulder function: it has increased in recent years. A detailed understanding of the anatomy of the glenoid and humeral head, as well as morphological changes of the glenoid in osteoarthritis, are important factors to consider when deciding on replacement components. This review begins with a brief introduction of the glenohumeral joint itself, and then considers the detailed anatomy of the glenoid fossa and humeral head, both of which are reported to have variable morphology. Several studies have been undertaken to assess various parameters, especially of the glenoid fossa including its shape, height, width, and articular surface area, version and inclination, in an attempt to define a standard classification that can be applied to surgical intervention. Nevertheless, no definitive consensus concerning the classification of these morphologies has been forthcoming, hence the need for this review. Following a consideration of these morphologies, the current state of knowledge regarding glenoid deformity in osteoarthritis, as well as its surgical management, is considered.