Risk factors for revision after shoulder arthroplasty: 1,825 shoulder arthroplasties from the Norwegian Arthroplasty Register

Utility of Patient Reported Outcome Measurement Information System measures in predicting shoulder arthroplasty in patients with shoulder osteoarthritis

BACKGROUND

The decision to treat shoulder osteoarthritis (OA) definitively with shoulder arthroplasty (SA) is multifactorial, considering objective findings, subjective information, and patient goals. The first goal of this study was to determine if Patient Reported Outcome Measurement Information System (PROMIS) measures correlated with patients with shoulder OA who underwent SA within 1 year. The second goal of this study was to determine if score cut-offs in PROMIS domains could further discriminate which shoulder OA patients underwent SA within 1 year.

METHODS

This retrospective case-control study examined patients with a diagnosis of shoulder OA who consulted an orthopedic provider from November 1, 2020 to May 23, 2022, and recorded PROMIS measures in the domains of Physical Function, Depression, and/or Pain Interference. A surgical group was defined as patients who underwent SA within 1 year of the most recent PROMIS measures and the nonsurgical patients were defined as the control group. Mean PROMIS scores were compared between the surgical and control groups. Separate logistic regression models controlling for age, race, ethnicity, and comorbidity count were performed for each PROMIS domain as a 1) continuous variable, and then as 2) binary variable defined by PROMIS score cut-off points to determine which scores correlated with undergoing SA to further characterize the potential clinical utility of PROMIS score cut-offs in relating to undergoing SA.

RESULTS

The surgical group of 478 patients was older (68.2 vs. 63.8 years), more often of White race (82.6% vs. 70.9%), and less often of Hispanic Ethnicity (1.5% vs. 2.9%) than the control group of 3343 patients. Using optimal cut-offs in PROMIS scores, Pain Interference ≥63 (odds ratio [OR] = 2.97 (2.41-3.64), P < .001), Physical Function ≤39 (OR = 1.81 (95% confidence interval, 1.48-2.22), P < .001), and depression ≥49 (OR = 1.82 (95% confidence interval, 1.50-2.22), P < .001) were all found to correlate with undergoing SA within 1 year in multivariable logistic regressions.

CONCLUSION

The results of this study demonstrate that cut-off scores for PROMIS measures differentiated patients undergoing SA within 1 year. These cut-off scores may have clinical utility in aiding in decision-making regarding surgical candidates for SA. Further research is needed to validate these cut-off scores and determine how they relate to patient outcomes after SA.

Influence of design features and brand of reverse shoulder arthroplasties on survivorship and reasons for revision surgery: results of 5,494 arthroplasties with up to 15 years' follow-up reported to the Norwegian Arthroplasty Register 2007-2022

BACKGROUND AND PURPOSE

We aimed to report the survival of different reverse shoulder arthroplasty (RSA) designs and brands, and factors associated with revision. The secondary aim was to evaluate the reasons for revision.

METHODS

We included 4,696 inlay and 798 onlay RSAs reported to the Norwegian Arthroplasty Register (NAR) 2007-2022. Kaplan-Meier estimates of survivorship and Cox models adjusted for age, sex, diagnosis, implant design, humeral fixation, and previous surgery were investigated to assess revision risks. The reasons for revision were compared using competing risk analysis.

RESULTS

Overall, the 10-year survival rate was 94% (confidence interval [CI] 93-95). At 5 years all brands exceeded 90%. Compared with Delta Xtend (n = 3,865), Aequalis Ascend Flex (HR 2.8, CI 1.7-4.6), Aequalis Reversed II (HR 2.2, CI 1.2-4.2), SMR (HR 2.5, CI 1.3-4.7), and Promos (HR 2.2, CI 1.0-4.9) had increased risk of revision. Onlay and inlay RSAs had similar risk of revision (HR 1.2, CI 0.8-1.8). Instability and deep infection were the most frequent revision causes. Male sex (HR 2.3, CI 1.7-3.1), fracture sequelae (HR 3.1, CI 2.1-5.0), and fractures operated on with uncemented humeral stems had increased risk of revision (HR 3.5, CI 1.6-7.3).

CONCLUSION

We found similar risk of revision with inlay and onlay designs. Some prosthesis brands had a higher rate of revision than the most common implant, but numbers were low.

Convertible-platform shoulder arthroplasty

Background

Shoulder arthroplasty has become an increasingly common procedure used to treat degenerative, inflammatory, and traumatic conditions of the glenohumeral joint. With a significant increase in primary anatomic and reverse total shoulder arthroplasty, revision procedures have likewise increased. Updates in shoulder arthroplasty have allowed for the convertibility of implants, which allows for the retention of both glenoid and humeral components during revision surgery. This review aims to highlight the epidemiology, indications, and outcomes of convertible-platform total shoulder arthroplasty procedures.

Methods

A review of the current literature surrounding convertible-platform shoulder arthroplasty was completed to highlight the advantages and disadvantages of commercially available instrumentation and implant systems as well as their outcomes.

Discussion

Leading causes of shoulder arthroplasty revision surgery include glenoid failure, implant instability, and rotator cuff dysfunction. Variations in implant design between inlay and onlay humeral components and metal-backed glenoid components are important considerations at the time of revision surgery. Advantages of convertible-platform systems include increased efficiency and decreased complications during revision procedures as well as shorter recovery, lower cost, and better functional outcomes. Limitations of convertible systems include poorly positioned components during the index procedure, excessive soft-tissue tensioning, and problems associated with metal-backed glenoid implants. Changes in arm length have also been documented. These findings indicate the benefit of additional research and design to improve the effectiveness and utility of convertible-platform shoulder arthroplasty systems.

Trends in Shoulder Arthroplasty in Germany: A 10-Year Epidemiological Analysis of Patients with Primary Osteoarthritis of the Shoulder

Shoulder arthroplasty has significantly gained popularity in orthopedic surgery, driven by progress in prosthesis design and surgical techniques. This study explored the epidemiology of shoulder arthroplasty, analyzing healthcare data from 2012 to 2022 for primary osteoarthritis of the shoulder. The data included patient demographics and types of surgical procedures. Data analysis indicates a higher utilization rate of reverse total shoulder arthroplasty (RTSA; n = 41,251) over total- (TSA; n = 18,679) and hemiarthroplasty (HSA; n = 12,827) for primary shoulder osteoarthritis. Overall, a significant increase in RTSA procedures from n = 2237 (2012) to n = 5415 (2022) was observed, representing more than a two-fold increase of 121.1%. The relative proportion of RTSA among all types of shoulder arthroplasty increased from 39% (2012) to 68.6% (2022), while HSA decreased and TSA essentially remained constant. Age analysis identified the following peaks: RTSA, 77 ± 7 y; HSA, 68 ± 12 y; and TSA, 67 ± 10 y. Among the over 60s, significantly more women were treated with any type of prosthesis, whereas in young patients (45 to 59 y), more men received HSA or TSA. Our study confirms that RTSA has become the preferred choice for elderly patients in Germany, reflecting the prevailing preference despite varying patient ages and conditions, with a noted difference in sex in treatment prevalence.

Shoulder arthroplasty for inflammatory arthritis is associated with higher rates of medical and surgical complications: a nationwide matched cohort analysis from 2016-2020

BACKGROUND

Inflammatory arthritis (IA) represents a less common indication for anatomic and reverse total shoulder arthroplasty (TSA) than osteoarthritis (OA). The safety and efficacy of anatomic and reverse TSA in this population has not been as well studied compared to OA. We analyzed the differences in outcomes between IA and OA patients undergoing TSA.

METHODS

Patients who underwent primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) from 2016-2020 were identified in the Premier Healthcare Database. Inflammatory arthritis (IA) patients were identified using International Classification of Diseases, Tenth Revision, diagnosis codes and compared to osteoarthritis controls. Patients were matched in a 1:8 fashion by age (±3 years), sex, race, and presence of pertinent comorbidities. Patient demographics, hospital factors, and patient comorbidities were compared. Multivariate regression was performed following matching to account for any residual confounding and 90-day complications were compared between the 2 cohorts. Descriptive statistics and regression analysis were employed with significance set at P < .05.

RESULTS

Prior to matching, 5685 IA cases and 93,539 OA controls were identified. Patients with IA were more likely to be female, have prolonged length of stay and increased total costs (P < .0001). After matching and multivariate analysis, 4082 IA cases and 32,656 controls remained. IA patients were at increased risk of deep wound infection (OR 3.14, 95% CI 1.38-7.16, P = .006), implant loosening (OR 4.11, 95% CI 1.17-14.40, P = .027), and mechanical complications (OR 6.34, 95% CI 1.05-38.20, P = .044), as well as a decreased risk of postoperative stiffness (OR 0.36, 95% CI 0.16-0.83, P = .002). Medically, IA patients were at increased risk of PE (OR 2.97, 95% CI 1.52-5.77, P = .001) and acute blood loss anemia (OR 1.27, 95% CI 1.12-1.44, P < .0001).

DISCUSSION AND CONCLUSION

Inflammatory arthritis represents a distinctly morbid risk profile compared to osteoarthritis patients with multiple increased surgical and postoperative medical complications in patients undergoing aTSA and rTSA. Surgeons should consider these potential complications and employ a multidisciplinary approach in preoperative risk stratification of IA undergoing shoulder replacement.

The Delta III and Delta Xtend reverse shoulder arthroplasty-risk of revision and failure mechanisms: a report on 3650 cases from the Norwegian Arthroplasty Register 1994-2021

BACKGROUND

The Delta reverse shoulder arthroplasty (RSA) is commonly used worldwide and is the most frequently used RSA in Norway. The aim of this registry-based study was to report 10- and 20-year implant survival, risk of revision, and reasons for revision in 2 consecutive time periods for Delta III (1994-2010) and Delta Xtend (2007-2021) prostheses.

METHODS

We included 3650 primary RSAs reported to the Norwegian Arthroplasty Register: 315 Delta III (42% cemented stems) and 3335 Delta Xtend (88% cemented stems). We used Kaplan-Meier analyses to investigate implant survival. The reasons for revision were compared for the 2 designs and fixation technique. Factors that could influence the risk of revision, such as implant design, fixation technique, and patient factors, were investigated using Cox regression analyses with adjustments for age, sex, and diagnosis.

RESULTS

Patients operated with Delta III were more likely to be diagnosed with inflammatory disease or fracture sequela, whereas acute fracture, osteoarthritis, and cuff arthropathy were the most frequent indications for Delta Xtend. Ten-year survival was 93.0% (95% confidence interval [CI]: 87.0-99.0) (cemented stem) and 81.6% (95% CI: 75.3-87.9) (uncemented stem) for Delta III and 94.7% (95% CI: 93.3-96.1) (cemented stem) and 95.7% (95% CI: 88.3-100) (uncemented stem) for Delta Xtend. Twenty-year survival for Delta III (uncemented stem) was 68.2% (95% CI: 58.8-77.6). Compared with DeltaXtend (cemented stem) at 10-year follow-up, we found a higher risk of revision for Delta III (uncemented stem) (hazard ratio [HR]: 2.9, 95% CI: 1.7-5.0), whereas no significant difference was found for Delta III (cemented stem) and Delta Xtend (uncemented stem). The most common reason for revision of Delta III (uncemented stem) was glenoid loosening followed by deep infection and instability. Instability was the most frequent revision cause for Delta Xtend (both cemented and uncemented stem). Men had an overall higher revision risk than women (HR: 2.8 [95% CI: 2.0-3.9]), and patients with fracture sequela had increased risk for revision (HR: 2.8, 95% CI: 1.7-4.7) compared with patients with osteoarthritis.

DISCUSSION

We found that Delta III (uncemented stem) had a higher risk of revision compared with Delta Xtend (cemented stem). The risk of revision for glenoid component loosening was lower for Delta Xtend, but revisions due to instability/dislocation are still a concern. This register study cannot determine whether the differences found were caused by differences in implant design or other factors that changed during the study period. Risk of revision may have been affected by the indication for primary operation.

Primary inlay reverse shoulder arthroplasty has a higher rate of revision than onlay reverse shoulder arthroplasty: Analysis from the Australian Orthopaedic Association National Joint Replacement Registry

Background

Two classes of primary reverse total shoulder arthroplasty (rTSA), inlay (in-rTSA), and onlay (on-rTSA) were compared to determine differences in rates of revision.

Methods

Between 1 January 2012 and 31 December 2020, all primary in-rTSA or on-rTSA procedures were compared from a large national arthroplasty registry by cumulative percentage revision (CPR). Kaplan-Meier estimates of survivorship and hazard ratios from Cox proportional hazard models adjusted for age, gender, glenosphere size, and humeral fixation determined any associations to the risk of revision.

Results

Of the 14,807 in-rTSA and 6590 on-rTSA procedures, the CPR at seven years was 4.9%. There was an increased risk of revision for in-rTSA vs on-rTSA (p = 0.039) when adjusted for age, gender, glenosphere size, and humeral fixation. Glenosphere size <38 mm adjusted for age and gender (p = 0.016) increased the revision risk. Revision for instability/dislocation occurred more often for in-rTSA vs on-rTSA (p < 0.001) in the first three months. Males had a higher rate of revision than females for in-rTSA (3months+, p = 0.001) and for on-rTSA (p < 0.001).

Discussion

Care should be taken when considering in-rTSA particularly in males, and if preoperative planning suggests a small (<38 mm) glenosphere.

Level of evidence

Level III, therapeutic study. Original article.

Primary Total Shoulder Arthroplasty is Superior to Hemiarthroplasty for the Treatment of Glenohumeral Arthritis: Analysis of 5-year Outcomes in a Large Surgical Database

Background

Total shoulder arthroplasty (TSA) is the preferred treatment for glenohumeral arthritis refractory to nonoperative measures. However, some surgeons have argued for a role for hemiarthroplasty (HA) in the setting of a smooth glenoid that articulates appropriately with the humeral head. The purpose of this study is to evaluate long-term revision rates and short-term postoperative complications in patients undergoing either HA or TSA for glenohumeral arthritis.

Methods

A retrospective review of patients who underwent HA and TSA was conducted using a commercially available national database. Demographics, postoperative complications, risk factors, revision rates, and costs were analyzed using 2 sample t-tests, chi-squared tests, and multivariate logistic regressions.

Results

Patients were stratified by operation: (1) HA (n = 1615) or 2) TSA (n = 7845). Patients undergoing primary TSA had higher rates of prior ipsilateral rotator cuff repair and corticosteroid injections. At 2 years, patients who underwent HA, 3.0% of patients had revision surgery, compared to 1.6% of patients who underwent TSA (P = .002); at 5 years, 3.7% of the HA cohort (P < .0001) had revision surgery, compared to 1.9% of patients who underwent TSA.

Conclusions

Patients undergoing TSA or RTSA for glenohumeral arthritis had higher preoperative co-morbidities but had no difference in short-term complication rates with a lower risk of revision surgery at both 2-year and 5-year follow-up when compared to HA. Increasing age, female sex, hyperlipidemia, postoperative infection, shoulder instability, and thromboembolism all independently increased odds for revision shoulder arthroplasty for glenohumeral arthritis.

Level of evidence Level

III.

Comparison of Outcomes After Reverse Total Shoulder Arthroplasty in Patients With Proximal Humerus Fractures Versus Rotator Cuff Arthropathy

INTRODUCTION

Indications for reverse total shoulder arthroplasty (rTSA) has expanded to encompass complex proximal humerus fractures (PHFs) in recent years. The purpose of this study was to report and assess whether PHF patients treated with rTSA could achieve similar functional outcomes and short-term survivorship to patients who underwent rTSA for rotator cuff arthropathy (RTCA).

METHODS

All consecutive patients with a preoperative diagnosis of PHF or RTCA, 18 years or older, treated with rTSA at a single academic institution between 2018 and 2020 with a minimum 2-year follow-up were retrospectively reviewed. Primary outcomes were survivorship defined as revision surgery or implant failure analyzed using the Kaplan-Meier survival curve, and functional outcomes, which included Quick Disabilities of the Arm, Shoulder, and Hand, and range of motion (ROM) were compared at multiple follow-up time points up to 2 years. Secondary outcomes were patient demographics, comorbidities, surgical data, length of hospital stay, and discharge disposition.

RESULTS

A total of 48 patients were included: 21 patients (44%) were diagnosed with PHF and 27 patients (56%) had RTCA. The Kaplan-Meier survival rate estimates at 3 years were 90.5% in the PHF group and 85.2% in the RTCA group. No differences in revision surgery rates between the two groups (P = 0.68) or survivorship (P = 0.63) were found. ROM was significantly lower at subsequent follow-up time points in multiple planes (P < 0.05). A greater proportion of patients in the PHF group received cement for humeral implant fixation compared with the RTCA group (48% versus 7%, P = 0.002). The mean length of hospital stay was longer in PHF patients compared with RTCA patients (2.9 ± 3.8 days versus 1.6 ± 1.8 days, P = 0.13), and a significantly lower proportion of PHF patients were discharged home (67% versus 96%, P = 0.015).

CONCLUSION

The rTSA implant survivorship at 3 years for both PHF and RTCA patients show comparable results. At the 2-year follow-up, RTCA patients treated with rTSA were found to have better ROM compared with PHF patients.

Image-derived instrumentation vs. conventional instrumentation with 3D planning for glenoid component placement in reverse total shoulder replacements: a randomized controlled trial

Hypothesis

Glenoid baseplate positioning for reverse total shoulder arthroplasty (rTSA) is important for stability and longevity, with techniques such as image-derived instrumentation (IDI) developed for improving implant placement accuracy. We performed a single-blinded randomized controlled trial comparing glenoid baseplate insertion accuracy with 3D preoperative planning and IDI jigs vs. 3D preoperative planning and conventional instrumentation.

Methods

All patients had a preoperative 3D computed tomography to create an IDI; then underwent rTSA according to their randomized method. Repeat computed tomography scans performed at six weeks postoperatively were compared to the preoperative plan to assess for accuracy of implantation. Patient-reported outcome measures and plain radiographs were collected with 2-year follow-up.

Results

Forty-seven rTSA patients were included (IDI n = 24, conventional instrumentation n = 23). The IDI group was more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane (P = .01); and exhibited a smaller degree of error when the native glenoid retroversion was >10° (P = .047). There was no difference in patient-reported outcome measures or other radiographic parameters between the two groups.

Conclusion

IDI is an accurate method for glenoid guidewire and component placement in rTSA, particularly in the superior/inferior plane and in glenoids with native retroversion >10°, when compared to conventional instrumentation.

Reverse Total Shoulder Arthroplasty for Proximal Humeral Fractures and Sequalae Compared to Non-Fracture Indications: A Matched Cohort Analysis of Outcome and Complications

Background: With the increase in utility and popularity of the reverse total shoulder arthroplasty (RTSA) within the last decades, indications for RTSA have expanded. As well as the established indications such as cuff tear arthropathy and massive irreparable rotator cuff tears, RTSA for complex proximal humeral fractures in elderly patients has been proven to be a reliable treatment option. Methods: A prospectively enrolled RTSA database of 1457 RTSAs implanted between September 2005 and November 2020 was reviewed. Patients treated with RTSA for a complex proximal humerus fracture and fracture sequalae (F-RTSA) were 1:1 matched with a group of patients who were treated electively with RTSA for indications other than a fracture (E-RTSA). Matching criteria included sex, age, length of follow-up and body mass index. Evaluation after a minimum of 2 years follow-up included evaluation of the absolute and relative Constant–Murley score (aCS; rCS), subjective shoulder value (SSV), range of motion (ROM) assessment and complications. Results: Each of the matched cohorts comprised 134 patients with a mean follow-up of 58 ± 41 months for the fracture group and 58 ± 36 months for the elective group. The mean age for both groups was 69 ± 11 years in the F-RTSA and 70 ± 9 years for the E-RTSA group. There were no significant differences in clinical outcome measures including aCS, rCS and SSV (p > 0.05). There was a significant difference in mean active external rotation with 20° ± 18° in the F-RTSA group compared with 25° ± 19° in the E-RTSA group (p = 0.017). The complication rate was not significantly different, with 41 complications in 36 shoulders in the F-RTSA and 40 complications in 32 shoulders in the E-RTSA group (p = 0.73). The main complication for the F-RTSA group was dislocation of the greater tuberosity (6%), whereas acromial fractures (9%) were the leading complication in the E-RTSA group. There was also no significant difference in revision rate comparing F-RTSA with E-RTSA (10% vs. 14%; p = 0.25). Conclusions: RTSA for complex proximal humeral fractures and its sequalae leads to a comparable clinical outcome as that for patients treated electively with RTSA for indications other than fracture. There was, however, a significant difference in active external rotation, with inferior rotation in patients undergoing RTSA for fracture. This valuable information can help in requesting informed consent of patients with proximal humeral fractures.

Revision Rates and Associated Risk Factors after Shoulder Arthroplasty

This study aims at answering the following questions (1) How high is the revision rate after osteoarthritis-, and rotator cuff-related compared to proximal humerus fracture (PHF)-related shoulder arthroplasty? (2) What are the associated risk factors for a revision after shoulder arthroplasty? Shoulder arthroplasty procedures occurring between 1 January 2009 and 31 December 2019 were identified from the Medicare database. First, revision rates for PHF patients and age- and sex-matched non-fracture patients, grouped into osteoarthritis-related and rotator cuff-related arthroplasty, were compared. Second, revision rates between total shoulder arthroplasty and hemiarthroplasty after PHF were compared. Semiparametric Cox regression was applied, incorporating 23 demographic, clinical, and socioeconomic covariates, to investigate risk factors for revision surgery. Between the considered time period from 2009 through 2019, a total number of 47,979 PHFs was identified. A shoulder arthroplasty procedure was performed in n = 2639 (5.5%, 95%CI: 4.8-6.1) of the cases. The five-year survivorship of the implant was 96.3 (95%CI: 93.8-97.9) after hemiarthroplasty and 96.1% (05%CI: 94.2-97.3) after total shoulder arthroplasty. To compare the revision rates, n = 14,775 patients with osteoarthritis and n = 4268 patients with rotator cuff arthropathy, who received a shoulder arthroplasty, served as a non-fracture control group. Patients receiving a rotator cuff-related arthroplasty were more likely to require a revision compared to patients treated for osteoarthritis (HR: 1.27, 95%CI: 1.04-1.44, p = 0.018). Identified significant risk factors for revision surgery after shoulder arthroplasty included age ≤ 75 years, male sex, and osteoporosis. High implant survival was found for hemiarthroplasty and total shoulder arthroplasty for the treatment of PHF in elderly patients. The risk of revision surgery was elevated in patients receiving a rotator cuff-related arthroplasty as well as in patients with osteoporosis, male patients and patients older than 75 years.

The clinical outcome of physiotherapy after reversed shoulder arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review was to analyze the current literature on the clinical outcomes of physiotherapy (PT) program after reversed total shoulder arthroplasty (rTSA) and to summarize the improvements in this population.

METHODS

A search was performed in four databases (MEDLINE, Embase, PubMed, Google Scholar) from its inception to 30 April 2020. Data were extracted to describe the study design and rehab programs. The quality of evidence was assessed as high, moderate, and low-level according to the Evaluation of Quality of an Intervention Study critical appraisal criteria.

RESULTS

There were 22 eligible studies including two randomized controlled trials, four prospective cohort studies, 10 retrospective reviews, five case-series, and one case-control study, with the sample sizes ranging from 9 to 474 patients followed for 1-10 years. All studies indicated substantial improvement in patients after PT program in terms of functional outcomes and forward flexion.

CONCLUSIONS

High-quality RCTs are required to provide more conclusive results. We identified substantial variation in the post-operative PT programs except for the progressive mobilization strategy and the common management following surgery to increase the soft tissue healing within 4-6 weeks.Implications for RehabilitationThe reverse shoulder arthroplasty (rTSA) has been widely utilized for patients with rotator cuff arthropathy, primary arthritis, and proximal fractures.A successful outcome of rTSA is not only depending on the surgical management, but also depended on physiotherapy (PT) programs.Our systematic review concluded that a 12-week PT program starting with immobilization for 4-6 weeks, followed by 3-4 phases PT exercises including PROM, AAROM, AROM, and strength training was recommended as common management for patients received rTSA.Due to the huge variation in the included studies, the evidence of PT protocol in our study was not sufficient to summarize the better clinical practice suggestions regarding rTSA rehabilitation.

The 50 Highest Cited Papers on Shoulder Arthroplasty

The purpose of this study was to determine the 50 most cited articles on shoulder arthroplasty (SA) and their characteristics. The Thomson ISIWeb of Science was searched with the following search terms: "shoulder arthroplasty", "shoulder replacement", "shoulder prosthesis" and "shoulder implant". All papers dealing with SA, including its perioperative and postoperative management, were included in this study. Citations ranged from 797 to 52 for the 50 highest cited papers on SA. According to absolute numbers, the top 10 papers were cited at least 118 times. Overall, 78% (n = 43) were clinical and the remaining articles were basic science research (one anatomic, six biomechanical). The most prevalent level of evidence was IV (72%). The Journal of Shoulder and Elbow Surgery published 40% of the studies. The majority of studies were conducted in the United States and eight other countries. The publication years of the most-cited articles ranged from 1991 to 2020, with the 2000s accounting for the most articles (96%) and the period from 2006 to 2010 with the absolute largest number of articles (17). This article provides a building block in the SA surgery.

Shoulder replacement: an epidemiological nationwide study from 2009 to 2019

Background

Shoulder replacement (SR) constitutes the gold standard treatment for severe shoulder diseases, including osteoarthritis, rheumatoid arthritis, complex fractures, avascular necrosis and rotator cuff arthropathy. Although several countries have national registries, there is a lack of epidemiological data on SR. Sharing national statistics and correlating those to other countries could be helpful to compare outcomes and costs internationally. This paper aims to evaluate the trend of hospitalizations for SR (both first implants and revisions of anatomical and reverse prosthesis) in Italy from 2009 to 2019, based on the National Hospital Discharge Reports (S.D.O) provided by the Italian National Health Service (INHS). Moreover, the economic impact on the healthcare system of SR and SR revisions was assessed, providing a statistical prediction for the next ten years.

Methods

The data used in this paper were about patients who underwent Total Shoulder Replacement (TSR), Shoulder Hemiarthroplasty (SH) or Revision of shoulder joint replacement (RSR) from 2009 to 2019 in Italy. Information about patients was anonymous and included age, sex, days of hospitalization, procedures and diagnoses codes.

Results

From 2009 to 2019, 73,046 TSR and SH were performed in adult Italian residents, with a cumulative incidence of 13.6 cases per 100,000 adult Italian residents. While, 2,129 revisions of shoulder replacement were performed, with a cumulative incidence of 0.4 cases per 100,000 residents. Overall, females represented the majority of the cases (72.4% of patients who underwent TSR or SH and 59.1% of patients who underwent RSR). From 2009 to 2019, has been assessed an overall cost of 625,638,990€ for TSR or SH procedures in Italy. While, an overall cost of 9,855,141€ for RSR procedures in Italy was calculated.

Conclusions

The incidence of SR and RSR is expected to increase in the following years, constituting a burden for the healthcare systems. Overall, in Italy, the females represented the majority of patients. Further prospective studies on this topic in different countries can be con-ducted to make comparisons.

Survivorship of Reverse Shoulder Arthroplasty According to Indication, Age and Gender

Background. The indications for reverse shoulder arthroplasty (RSA) have been widely expanded, but only a few studies report the long-term survival of these implants. Our objective was to report the long-term survivorship of a large series of RSAs implanted for different etiologies. Methods. A retrospective multicenter study including all the RSAs was performed in six shoulder-specialized centers with at least 2 years of follow up. We reviewed 1611 RSAs, operated between 1993 and 2010, including 497 cuff-tear arthropathies (CTA), 239 revision RSAs, 188 massive cuff tears (MCT), 185 fracture sequelae (FS), 183 failed previous cuff repairs (FCR), and 142 primary osteoarthritis (POA). The mean follow-up was 5.6 ± 3.9 years (range 2−20). Results. Overall, 266 RSAs (16.5%) had at least one complication leading to 64 reoperations (4.0%) and 110 revision surgeries (6.8%). The most frequent complications were infection (3.8%), instability (2.8%), and humerus-related complications (2.8%). At 10 years, the survival without revision surgery was 91.0% in primary RSAs and 80.9% in revision RSAs for failed arthroplasty (p < 0.001). In the primary RSA group, MCT and FCR led to 10-year survivals for over 95% but fracture sequelae and tumors had the lowest 10-year survivals (83.9% and 53.1%). Younger patients had a lower 10-year survival. In revision RSAs, male patients had a significantly lower survival than females (72.3% vs. 84.5% at 10 years, p = 0.020). Discussion. Primary RSA for cuff-deficient shoulders or POA leads to a high 10-year survival, but revision RSA or primary RSA for FS and tumors are at high-risk for revision. Surgeons should be aware of high rates of complications and lower survival rates of RSA in younger patients, in males, and in RSAs for revision surgery.

Medium- to Long-Term Outcomes after Reverse Total Shoulder Arthroplasty with a Standard Long Stem

Background: Long-term clinical and radiographic outcome data after standard cemented long-stem reverse shoulder arthroplasty (RSA) remain underreported. The aim of this study is to report on medium- to long-term data of patients over 60 years of age. Methods: The same type of RSA (Aequalis Reverse II, Memphis, TN, USA) was implanted in 27 patients with a mean age of 73 years (range 61−84). Indications for RSA were cuff tear arthropathy (CTA) in 25 cases and osteoarthritis (OA) in two cases. Pre- and postoperative Constant Score was assessed and component loosening, polyethylene wear, scapular notching and revision rates were recorded at a mean clinical follow-up (FU) of 127.6 months (SD ± 33.7; range 83−185). Results: The mean-adjusted CS (aCS) improved from 30.0 (range 10−59) to 95.0 (range 33−141) points (p < 0.001). Glenoid loosening was found in two (9.1%) and stem loosening was found in three (13.6%) cases. Polyethylene wear was observed in four (18.2%) cases. Scapular notching appeared in 15 (68.2%) cases but was not associated with poor aCS (p = 0.423), high levels of pain (p = 0.798) or external rotation (p = 0.229). Revision surgery was necessary in three (11.1%) cases. Conclusions: RSA with a cemented standard long stem leads to improvement in forward elevation, abduction and pain after a mean FU of 10 years. However, external rotation does not improve with this prosthetic design. Moreover, scapular notching is observed in the majority of cases, and revision rates (11.1%) as well as humeral loosening rates (13.6%) remain a concern. Level of evidence: Level 4, retrospective cohort study.

Effect of two types of shoulder prosthesis on the muscle forces using a generic multibody model for different arm motions

Background

This study aims to analyze the effects of a novel dual-bearing shoulder prosthesis and a conventional reverse shoulder prosthesis on the deltoid and rotator cuff muscle forces for four different arm motions. The dual-bearing prosthesis is a glenoid-sparing joint replacement with a moving center of rotation. It has been developed to treat rotator cuff arthropathy, providing an increased post-operative functionality.

Methods

A three-dimensional musculoskeletal OpenSim® model of an upper body, incorporating a natural gleno-humeral joint and a scapula-thoracic joint developed by Blana et al. (J Biomech 41: 1714-1721, 2008), was used as a reference for the natural shoulder. It was modified by integrating first a novel dual-bearing prosthesis, and second, a reverse shoulder prosthesis into the shoulder joint complex. Four different arm motions, namely abduction, scaption, internal and external rotation, were simulated using an inverse kinematics approach. For each of the three models, shoulder muscle forces and joint reaction forces were calculated with a 2 kg weight in the hand.

Results

In general, the maximal shoulder muscle force and joint reaction force values were in a similar range for both prosthesis models during all four motions. The maximal deltoid muscle forces in the model with the dual-bearing prosthesis were 18% lower for abduction and 3% higher for scaption compared to the natural shoulder. The maximal rotator cuff muscle forces in the model with the dual-bearing prosthesis were 36% lower for abduction and 1% higher for scaption compared to the natural shoulder. Although the maximal deltoid muscle forces in the model with the dual-bearing prosthesis in internal and external rotation were 52% and 64% higher, respectively, compared to the natural shoulder, the maximal rotator cuff muscle forces were 27% lower in both motions.

Conclusion

The study shows that the dual-bearing shoulder prosthesis is a feasible option for patients with rotator cuff tear and has a strong potential to be used as secondary as well as primary joint replacement. The study also demonstrates that computer simulations can help to guide the continued optimization of this particular design concept for successful clinical outcomes.

Conversion of Hemiarthroplasty to Reverse Shoulder Arthroplasty with Humeral Stem Retention

The purpose of this study is to evaluate the mid-term clinical results of an ongoing case series on conversion reverse shoulder arthroplasty (RSA) with a modular prosthesis system. We included 17 elderly patients revised for failed hemiarthroplasty after proximal humeral fracture, of which 13 were converted using a modular reverse shoulder prosthesis. Four could not be converted due to overstuffing. For the conversion RSA, we determined the Constant score, American Shoulder and Elbow Surgeons Shoulder Score, visual analogue scale for pain and satisfaction, and range of motion preoperatively, at one year, and at the last follow-up. All measured clinical outcomes improved significantly at both follow-up time points (p < 0.05). The mean duration of surgery was 118.4 min (range: 80.0 to 140.0 min). We observed complications in three patients; these included one late infection and two aseptic stem loosenings. Modular shoulder arthroplasty is a suitable procedure for conversion RSA in elderly patients. All measured postoperative clinical outcomes improved significantly, the complication rate was acceptable, and no prosthesis-related complications occurred. Conversion RSA, although not feasible in every case, is a viable treatment option in the elderly, which can provide successful mid-term results.

Prior Nonshoulder Periprosthetic Joint Infection Increases the Risk of Surgical Site Infection, Sepsis, and All-Cause Revision After Primary Total Shoulder Arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) after total joint arthroplasty is a known risk factor for infection in subsequent joint arthroplasty. The purpose of this study was to determine whether prior nonshoulder PJI contributes to the increased risk of infectious complications, greater healthcare utilization, and increased revision surgery after primary total shoulder arthroplasty (TSA).

METHODS

Patients who underwent primary TSA for osteoarthritis with prior nonshoulder PJI were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases codes. These patients were propensity matched based on age, sex, Charlson Comorbidity Index, smoking status, and obesity (body mass index >30 kg/m2) to a control cohort of patients who underwent primary TSA for osteoarthritis without any prior PJI. Primary outcomes include 1- and 2-year revision rates. Secondary outcomes include healthcare-specific outcomes of readmission, emergency department visits, length of stay, and mortality. Bivariate analysis was conducted using chi-square tests to compare all outcomes and complications between both cohorts.

RESULTS

Compared with patients without prior PJI, those with prior PJI had a significantly higher risk of 90-day surgical site infection (7.61% versus 0.56%) and sepsis (1.79% versus 0.56%) after TSA (P < 0.05 for both). Patients with prior PJI also had a higher risk of 90-day readmission compared with those without prior PJI (3.36% versus 1.23%, P = 0.008). In terms of surgical complications, patients with prior PJI had significantly higher risk of 2-year revision surgery compared with patients without prior PJI (3.36% versus 1.57%, P = 0.034).

CONCLUSION

Prior nonshoulder PJI of any joint increases rates of 90-day surgical site infection, sepsis, and hospital readmission, as well as 2-year all-cause revision after TSA. These results are important for risk-stratifying patients undergoing TSA with prior history of PJI.

LEVEL OF EVIDENCE

III.

Limited value of current shoulder arthroplasty registries in evidence-based shoulder surgery: a review of 7 national registries

National shoulder arthroplasty registries are currently used to assess incidence, indication, type of prosthesis and revision, but they seem to lack sufficient information to lead to evidence based decision-making in shoulder surgery. There appears to be a large difference in registered parameters and outcome measurement per country. First we investigated whether existing registries have sufficient common datasets to enable pooling of data. Second, we determined whether known risk factors for prosthetic failure are being recorded. Through a non-systematic literature review studies on registries were analyzed for included parameters. Seven national registries were scrutinized for the data collected and these were classified according to categories of risk factors for failure: patient-, implant and surgeon related, and other parameters. This shows a large heterogeneity of registered parameters between countries. The majority of parameters shown to be relevant to outcome and failure of shoulder prostheses are not included in the studied registries. International agreement on parameters and outcome measurement for registries is paramount to enable pooling and comparison of data. If we intend to use the registries to provide us with evidence to improve prosthetic shoulder surgery, we need adjustment of the different parameters to be included.

Trabecular bone density distribution in the scapula of patients undergoing reverse shoulder arthroplasty

Background

To improve implant survival after reverse shoulder arthroplasty (RSA), surgeons need to maximize screw fixation. However, bone density variation and distribution within the scapula are not well understood as they relate to RSA. The three columns of bone in the scapula surrounding the glenoid fossa are the lateral border, the base of the coracoid process, and the spine of the scapula. In our previous study by Daalder et al on cadaveric specimens, the coracoid column was significantly less dense than the lateral border and spine. This study’s objective was to verify whether these results are consistent with computer tomography (CT) scan information from patients undergoing RSA.

Methods

Two-dimensional axial CT images from twelve patients were segmented, and a three-dimensional digital model of the scapula was subsequently created using Mimics 17.0 Materialise Software (Leuven, Belgium). Hounsfield unit (HU) values representing cortical bone were filtered out to determine the distributions of trabecular bone density. An analysis of variance with post hoc Bonferroni tests determined the differences in bone density between the columns of bone in the scapula.

Results

The coracoid superolateral (270 ± 45.6 HU) to the suprascapular notch was significantly less dense than the inferior (356 ± 63.6 HU, P = .03, d_s = 1.54) and anterosuperior portion of the lateral border (353 ± 68.9 HU, P = .04, d_s = 1.42) and the posterior (368 ± 70 HU, P = .007, d_s = 1.65) and anterior spine (370 ± 78.9 HU, P = .006, d_s = 1.54).

Discussion/Conclusion

The higher-density bone in the spine and lateral border compared with the coracoid region may provide better bone purchase for screws when fixing the glenoid baseplate in RSA. This is in agreement with our previous study and indicates that the previous cadaveric results are applicable to clinical CT scan data. When these studies are taken together, they provide robust evidence for clinical applications, including having surgeons aim screws for higher-density regions to increase screw fixation, which may decrease micromotion and improve implant longevity.

Clinically relevant results of reverse total shoulder arthroplasty for patients younger than 65 years compared to the older patients

Background

Reverse total shoulder arthroplasty was originally designed for older patients with rotator cuff arthropathy and produces good results. The main objective of this retrospective study was to compare the patients younger than 65 years vs. the older patients in terms of the complications of reverse total shoulder arthroplasty and the functional recovery.

Methods

From January 2014 to January 2020, 566 patients who underwent the reverse total shoulder arthroplasty were divided into two groups (group A, ≥ 65 years, n = 506; group B, < 65 years, n = 60). The patients reported the quality of life using the patient-reported Western Ontario Osteoarthritis of the Shoulder index. The Constant score was obtained preoperatively and 3 months postoperatively. The complications and reoperations were compared. Statistical significance was set at P < 0.05.

Results

Clinically relevant improvements were found in group A and B. There was a multivariate statistically-significant but not clinically relevant difference in the change over time between group A and B. The mean 12-month Western Ontario Osteoarthritis of the Shoulder indexes were 58 in group B and 71 in group A. The mean Constant scores were 44 in group B vs. 43 in group A. Compared to group A, group B had a non-significant odds ratio of 1.9, which did not reach the clinically relevant Western Ontario Osteoarthritis of the Shoulder index of group A.

Conclusion

In patients younger than 65 years of age, RTSA seems to be a safe procedure in short term follow-up. After 1 year, we found no increased risk of complications, revision, or inferior outcomes compared to patients older than 65 years of age. Consequently, after one-year, RTSA provided clinically relevant improvements in the patients’ quality of life and shoulder strength regardless of age.

Minimum five-year outcomes of reverse total shoulder arthroplasty using a trabecular metal glenoid base plate

AIMS

Reverse total shoulder arthroplasty (RTSA) using trabecular metal (TM)-backed glenoid implants has been introduced with the aim to increase implant survival. Only short-term reports on the outcomes of TM-RTSA have been published to date. We aim to present the seven-year survival of TM-backed glenoid implants along with minimum five-year clinical and radiological outcomes.

METHODS

All consecutive elective RTSAs performed at a single centre between November 2008 and October 2014 were reviewed. Patients who had primary TM-RTSA for rotator cuff arthropathy and osteoarthritis with deficient cuff were included. A total of 190 shoulders in 168 patients (41 male, 127 female) were identified for inclusion at a mean of 7.27 years (SD 1.4) from surgery. The primary outcome was survival of the implant with all-cause revision and aseptic glenoid loosening as endpoints. Secondary outcomes were clinical, radiological, and patient-related outcomes with a five-year minimum follow-up.

RESULTS

The implant was revised in ten shoulders (5.2%) with a median time to revision of 21.2 months (interquartile range (IQR) 9.9 to 41.8). The Kaplan-Meier survivorship estimate at seven years was 95.9% (95% confidence interval (CI) 91.7 to 98; 35 RTSAs at risk) for aseptic mechanical failure of the glenoid and 94.8% (95% CI 77.5 to 96.3; 35 RTSAs at risk) for all-cause revision. Minimum five-year clinical and radiological outcomes were available for 103 and 98 RTSAs respectively with a median follow-up time of six years (IQR 5.2 to 7.0). Median postoperative Oxford Shoulder Score was 38 (IQR 31 to 45); median Constant and Murley score was 60 (IQR 47.5 to 70); median forward flexion 115° (IQR 100° to 125°); median abduction 95° (IQR 80° to 120°); and external rotation 25° (IQR 15° to 40°) Scapular notching was seen in 62 RTSAs (63.2%).

CONCLUSION

We present the largest and longest-term series of TM-backed glenoid implants demonstrating 94.8% all-cause survivorship at seven years. Specifically pertaining to glenoid loosening, survival of the implant increased to 95.9%. In addition, we report satisfactory minimum five-year clinical and radiological outcomes. Cite this article: Bone Joint J 2021;103-B(8):1333-1338.

Augmented-Reality-Assisted K-Wire Placement for Glenoid Component Positioning in Reversed Shoulder Arthroplasty: A Proof-of-Concept Study

The accuracy of the implant's post-operative position and orientation in reverse shoulder arthroplasty is known to play a significant role in both clinical and functional outcomes. Whilst technologies such as navigation and robotics have demonstrated superior radiological outcomes in many fields of surgery, the impact of augmented reality (AR) assistance in the operating room is still unknown. Malposition of the glenoid component in shoulder arthroplasty is known to result in implant failure and early revision surgery. The use of AR has many promising advantages, including allowing the detailed study of patient-specific anatomy without the need for invasive procedures such as arthroscopy to interrogate the joint's articular surface. In addition, this technology has the potential to assist surgeons intraoperatively in aiding the guidance of surgical tools. It offers the prospect of increased component placement accuracy, reduced surgical procedure time, and improved radiological and functional outcomes, without recourse to the use of large navigation or robotic instruments, with their associated high overhead costs. This feasibility study describes the surgical workflow from a standardised CT protocol, via 3D reconstruction, 3D planning, and use of a commercial AR headset, to AR-assisted k-wire placement. Post-operative outcome was measured using a high-resolution laser scanner on the patient-specific 3D printed bone. In this proof-of-concept study, the discrepancy between the planned and the achieved glenoid entry point and guide-wire orientation was approximately 3 mm with a mean angulation error of 5°.

Thromboprophylaxis in primary shoulder arthroplasty does not seem to prevent death: a report from the Norwegian Arthroplasty Register 2005-2018

Background and purpose - There is still no consensus on whether to use thromboprophylaxis as a standard treatment in shoulder replacement surgery. We investigated the use of thromboprophylaxis reported to the Norwegian Arthroplasty Register (NAR). The primary endpoint was early mortality after primary shoulder arthroplasty with and without thromboprophylaxis. Secondary endpoints included revisions within 1 year and intraoperative complications.Patients and methods - This observational study included 6,123 primary shoulder arthroplasties in 5,624 patients reported to the NAR from 2005 to 2018. Cox regression analyses including robust variance analysis were performed with adjustments for age, sex, ASA score, diagnosis, type of implant, fixation, duration of surgery, and year of primary surgery. An instrumental variable Cox regression was performed to estimate the causal effect of thromboprophylaxis.Results - Thromboprophylaxis was used in 4,089 out of 6,123 shoulder arthroplasties. 90-day mortality was similar between the thromboprophylaxis and no thromboprophylaxis groups (hazard ratio (HR) = 1.1, 95% CI 0.6-2.4). High age (> 75), high ASA class (≥ 3), and fracture diagnosis increased postoperative mortality. No statistically significant difference in the risk of revision within 1 year could be found (HR = 0.6, CI 0.3-1.2). The proportion of intraoperative bleeding was similar in the 2 groups (0.2%, 0.3%).Interpretation - We had no information on cause of death and relation to thromboembolic events. However, no association of reduced mortality with use of thromboprophylaxis was found. Based on our findings routine use of thromboprophylaxis in shoulder arthroplasty can be questioned.

The rate of 2nd revision for shoulder arthroplasty as analyzed by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)

Background and purpose - The increase in shoulder arthroplasty may lead to a burden of revision surgery. This study compared the rate of (2nd) revision following aseptic 1st revision shoulder arthroplasty, considering the type of primary, and the class and type of the revision.Patients and methods - All aseptic 1st revisions of primary total reverse shoulder arthroplasty (rTSA group) and of primary total stemmed and stemless total shoulder arthroplasty (non-rTSA group) procedures reported to our national registry between April 2004 to December 2018 were included. The rate of 2nd revision was determined using Kaplan-Meier estimates and comparisons were made using Cox proportional hazards models.Results - There was an increased risk of 2nd revision in the 1st month only for the rTSA group (n = 700) compared with the non-rTSA group (n = 991); hazard ratio (HR) = 4.8 (95% CI 2.2-9). The cumulative percentage of 2nd revisions (CPR) was 24% in the rTSA group and 20% in the non-rTSA group at 8 years. There was an increased risk of 2nd revision for the type (cup vs. head) HR = 2.2 (CI 1.2-4.2), but not class of revision for the rTSA group. Minor (> 3 months) vs. major class revision, and humeral revision vs. all other revision types were second revision risk factors for the non-rTSA group.Interpretation - The CPR of revision shoulder arthroplasty was > 20% at 8 years and was influenced by the type of primary, the class, and the type of revision. The most common reasons for 2nd revision were instability/dislocation, loosening, and infection.

An analysis of the Oxford Shoulder Score and its relationship to early joint revision in the New Zealand Joint Registry

BACKGROUND

Primary shoulder arthroplasties significantly improve shoulder function and have acceptable prosthesis survival for various indications. Currently, no validated shoulder questionnaire exists that can anticipate the early failure of primary shoulder arthroplasties. This study hypothesized that the Oxford Shoulder Score (OSS) after primary shoulder arthroplasty at 6 months would be significantly associated with early revision procedures.

METHODS

Data on all primary and revision shoulder arthroplasties covering the period of January 1, 1999, to December 31, 2019, were obtained from the New Zealand Joint Registry. The OSS questionnaires at 6 months were analyzed with regard to their relationship to revision within 2 years from the questionnaire date. Confounding risk factors were adjusted for in multivariate logistic regression analysis.

RESULTS

Statistical analysis revealed that the 6-month OSS had a significant association with revision in the following 2 years for anatomic total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RSA), and shoulder hemiarthroplasty (HA) (P < .001). An OSS of ≤44 for TSAs, ≤40 for RSAs, and ≤33 for HAs accounted for 68.9%, 63.1%, and 50.7%, respectively, while capturing at least 85% of revisions for all prostheses within the following 2 years.

CONCLUSION

This study confirms that a poor OSS at 6 months is an independent risk factor for early revision after TSA, RSA, and HA. We recommend discharging patients with a 6-month OSS greater than the identified threshold values for each prosthesis to improve resource efficiency.

[Shoulder arthroplasty]

Arthroplasty of the shoulder joint leads to excellent clinical results if the indications are valid and the implantation is technically correct. Taking anatomical requirements and mechanical functions as well as material properties and developments in surgical techniques into account, articulations and anchoring systems have been developed which, as modular systems enable successful restoration of the biomechanics and consider the importance of the surrounding soft tissues. Scientific data show promising medium-term and long-term results in terms of functionality and pain reduction. Nevertheless, due to the limited bone stock for implant anchoring, especially loosening of the prosthesis or instability of the glenoid joint component, revision arthroplasty remains challenging. This review article summarizes the relevant aspects of shoulder arthroplasty.

Is preoperative glenoid bone mineral density associated with aseptic glenoid implant loosening in anatomic total shoulder arthroplasty?

Background

Aseptic loosening of glenoid implants is the primary revision cause in anatomic total shoulder arthroplasty (aTSA). While supported by biomechanical studies, the impact of glenoid bone quality, more specifically bone mineral density (BMD), on aseptic glenoid loosening remains unclear. We hypothesized that lower preoperative glenoid BMD was associated with aseptic glenoid implant loosening in aTSA.

Methods

We retrospectively included 93 patients (69 females and 24 males; mean age, 69.2 years) who underwent preoperative non-arthrographic shoulder computed tomography (CT) scans and aTSA between 2002 and 2014. Preoperative glenoid BMD (CT numbers in Hounsfield unit) was measured in 3D using a reliable semi-automated quantitative method, in the following six contiguous volumes of interest (VOI): cortical, subchondral cortical plate (SC), subchondral trabecular, and three successive adjacent layers of trabecular bone. Univariate Cox regression was used to estimate the impact of preoperative glenoid BMD on aseptic glenoid implant loosening. We further compared 26 aseptic glenoid loosening patients with 56 matched control patients.

Results

Glenoid implant survival rates were 89% (95% confidence interval CI, 81–96%) and 57% (41–74%) at 5 and 10 years, respectively. Hazard ratios for the different glenoid VOIs ranged between 0.998 and 1.004 (95% CI [0.996, 1.007], p≥0.121). Only the SC VOI showed significantly lower CTn in the loosening group (622±104 HU) compared with the control group (658±88 HU) (p=0.048), though with a medium effect size (d=0.42). There were no significant differences in preoperative glenoid BMD in any other VOI between patients from the loosening and control groups.

Conclusions

Although the preoperative glenoid BMD was statistically significantly lower in the SC region of patients with aseptic glenoid implant loosening compared with controls, this single-VOI difference was only moderate. We are thus unable to prove that lower preoperative glenoid BMD is clearly associated with aseptic glenoid implant loosening in aTSA. However, due to its proven biomechanical role in glenoid implant survival, we recommend extending this study to larger CT datasets to further assess and better understand the impact of preoperative glenoid BMD on glenoid implant loosening/survival and aTSA outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03892-0.

Shoulder arthroplasty for juvenile idiopathic arthritis

There is limited literature to guide shoulder surgeons in the management of juvenile idiopathic arthritis (JIA). We aim to help clinicians to formulate an approach to the surgical management of the condition through a review of the available literature on arthroplasty in JIA, general considerations when operating on patients with inflammatory arthropathy and recommendations based on the authors' experience. Four articles report formal data on arthroplasty in JIA with favourable improvements in post-operative pain and function scores after the long-term follow-up. Significant heterogeneity in treatment and a lack of standardisation in quantitative outcomes highlights the need for further larger scale and higher quality research. The aim of this study is to review the evidence and provide information on preoperative evaluation of surgical candidates, operative techniques, choice of implant design and to evaluate functional outcomes in patients who undergo shoulder arthroplasty.

Outcomes of Posterior Glenoid Bone-Grafting in Anatomical Total Shoulder Arthroplasty: A Systematic Review

BACKGROUND

Total shoulder arthroplasty offers a reliable means with which to treat glenohumeral joint arthritis. Posterior glenoid bone loss presents a unique challenge with an increased risk of glenoid component failure. The use of posterior bone-grafting is one method to address glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty. The purpose of the present study was to assess the outcome and survival of the glenoid component following the use of bone graft to address posterior glenoid bone loss in patients undergoing anatomical total shoulder arthroplasty.

METHODS

A systematic review of posterior glenoid bone-grafting in patients undergoing anatomical total shoulder arthroplasty was performed. Studies evaluating patient-reported outcomes, complications, and imaging assessments of the glenoid component as well as of bone graft structural healing and integrity following posterior glenoid bone-grafting were included. Data extracted included demographic characteristics, Walch classification, bone-grafting method, clinical outcomes measures, complications, radiolucency around the glenoid component, graft failure, posterior humeral head subluxation, and time of the latest follow-up.

RESULTS

Six studies met the inclusion and exclusion criteria. Ninety-four patients from these 6 studies underwent posterior glenoid bone-grafting with anatomical total shoulder arthroplasty. The mean age was 59.7 years, and the mean duration of follow-up was 5.7 years. Overall, 57% of the patients had an excellent postoperative Neer score. At the time of the latest follow-up, 28.7% had evidence of radiolucency and 35% had humeral head subluxation or instability. Thirteen patients (14%) underwent revision of the glenoid component by the time of the latest follow-up.

CONCLUSIONS

The present study demonstrated a 28.7% complication rate, a 14% revision rate, a 17% graft failure rate, and a 35% rate of recurrence of posterior humeral head subluxation. Posterior glenoid bone-grafting to correct bone loss is associated with a substantial risk of postoperative complications. The treatment of posterior glenoid bone loss remains a challenge in patients undergoing anatomical total shoulder arthroplasty.

LEVEL OF EVIDENCE

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

Substantial clinical benefit, responsiveness, and sensitivity to change of three common outcome measures following shoulder arthroplasty

Objectives:

It is important for clinicians involved in the care of patients with advanced glenohumeral osteoarthritis to determine clinically significant change when using outcome measures. There is little information on the amount of substantial clinical benefit in shoulder outcomes after shoulder arthroplasty. The purpose of this study was twofold: (1) to quantify substantial clinical benefit for the American Shoulder and Elbow Surgery score, the Constant Murley Score, and the Western Ontario Osteoarthritis of the Shoulder index and (2) to provide estimates of responsiveness and sensitivity to change for these measures following shoulder arthroplasty.

Methods:

The study involved a secondary analysis of previously collected data. The substantial clinical benefit and responsiveness of the measures were calculated based on external anchors related to change in pain, range of motion, and ability to carry out activities of daily living. The areas under curve and standardized response mean represented responsiveness and sensitivity to change.

Results:

The data of 159 and 131 patients with complete follow-up at 6 months and 2 years were reviewed. The amount of substantial clinical benefit was dependent on the outcome measure and the external anchor and increased for all measures from 6 months to 2 years. Responsiveness was high (areas under curve > 0.80) at 6 months and further improved at 2 years (areas under curve > 0.88). The standardized response mean values of both time points were over 2.00, indicating high effect sizes. The standardized response means of the Constant Murley Score were statistically significantly higher than the standardized response means of the American Shoulder and Elbow Surgery and Western Ontario Osteoarthritis of the Shoulder.

Conclusion:

Amount of substantial clinical improvement in pain, range of motion, and activities of daily living following shoulder arthroplasty depends on the type of outcome measure used. All three measures, the American Shoulder and Elbow Surgery, absolute and relative Constant Murley Score, and Western Ontario Osteoarthritis of the Shoulder, demonstrated good to excellent accuracy and optimal standardized response means.

Level of evidence:

Level III, Retrospective Cohort study

Comparison of survivorship and performance of a platform shoulder system in anatomic and reverse total shoulder arthroplasty

Background

Contemporary studies note sustained clinical benefit and decreasing complications after reverse total shoulder arthroplasty (RTSA), which warrant a comparison with the standard anatomic total shoulder arthroplasty (ATSA). The purpose of this study is to evaluate and compare differences in midterm survivorship between ATSA and RTSA patients treated with a single platform shoulder prosthesis. Secondary objectives include a comparison of the clinical outcomes and complication profile for each procedure.

Methods

A prospective analysis of all primary ATSA and RTSA performed by 3 surgeons between 2007 and 2012 was conducted. Selection of the ATSA or RTSA implant configuration was determined by the surgeons per their clinical understanding of each individual patient's glenoid morphology, rotator cuff, and patient expectations. All 778 procedures were performed using a single platform shoulder system.

Results

Survivorship for ATSA was similar to that for RTSA at all time points; ATSA at 2 and 8 years was 98.5% and 96.0%, whereas RTSA at 2 and 8 years was 98.7% and 96.0%, respectively ( P= .392). All postoperative range of motion scores for ATSA patients were greater than those for RTSA patients. The overall rate of complications between the ATSA and RTSA groups was similar (6.3% vs. 4.9%, P= .414).

Conclusions

On the basis of this cohort comparison, both ATSA and RTSA demonstrated similar survivorship at 8 years after surgery with multiple surgeons practicing in different countries. Our results demonstrate that the RTSA and ATSA implants have comparable results and can be expected to provide similar implant longevity over the midterm with excellent functional outcomes.

Re-intervention and revision rates following primary reverse total shoulder arthroplasty - review of a local shoulder arthroplasty registry

PURPOSE

Our primary aim was to describe the re-intervention and revision rates after primary reverse shoulder arthroplasty (RSA) documented in a local shoulder arthroplasty registry. We also identify the main indication for revision and re-intervention, which may be relevant for patient outcome post-RSA.

METHODS

Since July 2006, RSAs are consecutively documented in our clinic registry and prospectively controlled with follow-ups. Any intervention after primary RSA requiring a return to the operating room for any shoulder-related indication was termed a re-intervention. Revisions were defined as surgeries involving any exchange, removal, or addition of at least one component. The study endpoints were survival rates at two, five and ten years follow-up for both definitions.

RESULTS

Until July 2017, 63 from a total of 1480 primary RSAs required at least one re-intervention and 33 patients had a revision. Open reduction and internal fixation for fractures around the implant (n = 14) were the predominating indications for re-intervention. The re-intervention rate for instability was 0.5%. For re-interventions, survival rates were 97.7, 95.4 and 90.8% at two, five and ten years, respectively, and the respective rates for revisions were 98.7, 97.5 and 95.3%.

CONCLUSION

The revision rate after primary RSA for our patient registry is low. A relevant number of additional interventions were noted that did not require any component revision but may impair the final outcome post-RSA. By only reporting revision rates, the number of post-RSA re-interventions is clearly underestimated. We recommend the documentation of all events leading to any re-intervention in arthroplasty registries.

Therapeutic postoperative anticoagulation is a risk factor for wound complications, infection, and revision after shoulder arthroplasty

BACKGROUND

The purpose of the present study was to examine the relationship between postoperative therapeutic anticoagulation, wound complications, infection, and revision.

METHODS

Using a national insurance database from 2007 to 2016, patients who underwent shoulder arthroplasty with an indication for postoperative therapeutic anticoagulation in the case of atrial fibrillation or acute postoperative venous thromboembolism were identified. Those with a prescription for a therapeutic anticoagulant within 2 weeks of surgery were identified and compared with controls without postoperative therapeutic anticoagulant prescriptions. Wound complications and postoperative infection at 3 and 6 months, and revision shoulder arthroplasty at 6 months and all time points were then compared in the database using a multivariable logistic regression analysis.

RESULTS

A total of 17,272 patients were included, including 684 patients who received therapeutic anticoagulation and 16,588 controls. Patients receiving therapeutic anticoagulation experienced increased wound complications at 3 months (odds ratio [OR] 3.0, 95% confidence interval [CI] 2.0-4.6, P < .0001) and 6 months (OR 2.5, 95% CI 1.7-3.8, P < .0001). Patients receiving therapeutic anticoagulation also experienced increased rates of wound infection at 3 months (OR 1.5, 95% CI 1.1-2.0, P = .007) and 6 months (OR 1.8, 95% CI 1.4-2.3, P < .0001). Finally, patients receiving therapeutic anticoagulation experienced increased rates of revision surgery at 6 months (OR 1.8, 95% CI 1.3-2.5, P = .0003) and within 9 years (OR 1.5, 95% CI 1.1-2.0, P = .007).

CONCLUSIONS

Wound complications and revision rates in patients undergoing shoulder arthroplasty who require postoperative therapeutic anticoagulation are significantly elevated compared with controls.

Revision of failed shoulder arthroplasty: epidemiology, etiology, and surgical options

BACKGROUND

Our aim was to analyze the epidemiology, etiologies, and revision options for failed shoulder arthroplasty from 2 tertiary centers.

METHODS

From 1993 to 2013, 542 failed arthroplasties were revised in 540 patients (65% women): 224 hemiarthroplasties (HAs, 41%), 237 anatomic total shoulder arthroplasties (TSAs, 44%) and 81 reverse total arthroplasties (RSAs, 15%). Data about patients, pathology, and reintervention procedures, as well as intraoperative data, were analyzed from our 2 local registries that prospectively captured all the revision procedures. Patients had an average follow-up period of 8.7 years.

RESULTS

The revision rate was 12.7% for HAs, 6.7% for TSAs, and 3.9% for RSAs. HAs were revised earlier (33 ± 40 months) than RSAs (47 ± 150 months) and TSAs (69 ± 61 months). Glenoid failure was a major cause of reintervention: erosion in HAs (29%) or loosening in TSAs (37%) and RSAs (24%). Instability was another major cause of reintervention: 32% in RSAs, 20% in TSAs, and 13% in HAs. Humeral implant loosening led to revision in 10% of RSAs, 6% of HAs, and 6% of TSAs. Multiple reinterventions were required in 21% of patients, mainly for instability (26%) and/or infection (25%). The final implant was an RSA in 48%, especially when associated with cuff insufficiency, instability, and/or bone loss. Final reimplantation was possible in 90% of cases, with the remaining 10% treated with a resection or spacer.

CONCLUSION

Glenoid failure and instability are the most common causes of revision. Soft-tissue insufficiency and/or infection results in multiple revisions. Surgeons must recognize all complications so that they can be addressed at the first revision operation and avoid further reinterventions. RSA was the most common final revision implant.

Safety and Effectiveness of Shoulder Arthroplasties in Spain: A Systematic Review

The effectiveness and safety of shoulder arthroplasties in the general context of a Spanish patient population remains unclear. The aim of this study was to ascertain both the effectiveness and safety of primary shoulder arthroplasties and the prosthesis types used in Spain. A systematic review of all the available literature evaluating the effectiveness and safety of primary shoulder arthroplasties in Spain was performed. A narrative synthesis was performed, and evidence tables were created in four dimensions: study design, arthroplasty characteristics, safety, and effectiveness. Orthopaedic Data Evaluation Panel (ODEP) scores were used to evaluate prosthesis types. Twenty-one studies were selected that included a total of 1293 arthroplasties. The most common indication was fractures, while the prosthesis most frequently used was the Delta Xtend (ODEP 10A). The most common complication was scapular notching. Prosthesis revision rate was approximately 6% for follow-ups between 12 and 79 months. In addition, significant improvements were observed in the Constant-Murley test score after the intervention. Currently in Spain, shoulder arthroplasty can be considered a safe and effective procedure with functional recovery and pain reduction for eligible patients with humeral fracture, rotator cuff arthropathy, fracture sequelae and malunion of the proximal humerus, and degenerative disease. Future longitudinal research and population-based studies could serve to confirm these results and identify points of improvement.

Core set of unfavorable events of shoulder arthroplasty: an international Delphi consensus process

BACKGROUND

Shoulder arthroplasty (SA) complications require standardization of definitions and are not limited to events leading to revision operations. We aimed to define an international consensus core set of clinically relevant unfavorable events of SA to be documented in clinical routine practice and studies.

METHODS

A Delphi exercise was implemented with an international panel of experienced shoulder surgeons selected by nomination through professional societies. On the basis of a systematic review of terms and definitions and previous experience in establishing an arthroscopic rotator cuff repair core set, an organized list of SA events was developed and reviewed by panel members. After each survey, all comments and suggestions were considered to revise the proposed core set including local event groups, along with definitions, specifications, and timing of occurrence. Consensus was reached with at least two-thirds agreement.

RESULTS

Two online surveys were required to reach consensus within a panel involving 96 surgeons. Between 88% and 100% agreement was achieved separately for local event groups including 3 intraoperative (device, osteochondral, and soft tissue) and 9 postoperative event groups. Experts agreed on a documentation period that ranged from 3 to 24 months after SA for 4 event groups (peripheral neurologic, vascular, surgical-site infection, and superficial soft tissue) and that was lifelong until implant revision for other groups (device, osteochondral, shoulder instability, pain, late hematogenous infection, and deep soft tissue).

CONCLUSION

A structured core set of local unfavorable events of SA was developed by international consensus to support the standardization of SA safety reporting. Clinical application and scientific evaluation are needed.

A Point-Based Model to Predict Absolute Risk of Revision in Anatomic Shoulder Arthroplasty

Background

Total shoulder arthroplasty (TSA) has demonstrated good long-term survivorship but early implant failure can occur. This study identified factors associated with shoulder arthroplasty revision and constructed a risk score for revision surgery following shoulder arthroplasty.

Methods

A validated algorithm was used to identify all patients who underwent anatomic TSA between 2002 and 2012 using population-based data. Demographic variables included shoulder implant type, age and sex, Charlson comorbidity score, income quintile, diagnosis, and surgeon arthroplasty volume. The associations of covariates with time to revision were measured while treating death as a competing risk and were expressed in the Shoulder Arthroplasty Revision Risk Score (SARRS).

Results

During the study period, 4079 patients underwent TSA. Revision risk decreased in a nonlinear fashion as patients aged and in the absence of osteoarthritis with no influence from surgery type or other covariables. The SARRS ranged from −21 points (5-year revision risk 0.75%) to 30 points (risk 11.4%). Score discrimination was relatively weak 0.55 (95% confidence interval: 0.530.61) but calibration was very good with a test statistic of 5.77 (df = 8, P = .762).

Discussion

The SARRS model accurately predicted the 5-year revision risk in patients undergoing TSA. Validation studies are required before this score can be used clinically to predict revision risk. Further study is needed to determine if the addition of detailed clinical data including functional outcome measures and the severity of glenohumeral arthrosis increases the model’s discrimination.

Risk factors for and timing of adverse events after revision total shoulder arthroplasty

BACKGROUND

Despite increasing rates of revision total shoulder arthroplasty (RTSA), there is a paucity of literature on optimizing perioperative outcomes. The purposes of this study were to identify risk factors for unplanned readmission and perioperative complications following RTSA, risk-stratify patients based on these risk factors, and assess timing of complications.

METHODS

Bivariate and multivariate analyses of risk factors were assessed on RTSA patients from the ACS-NSQIP database from 2011 to 2015. Patients were risk-stratified and timing of severe adverse events and cause of readmission were evaluated.

RESULTS

Of 809 RTSA patients, 61 suffered a perioperative complication or readmission within 30 days of discharge. Multivariate analysis identified operative time, BMI > 40, infection etiology, high white blood cell count, and low hematocrit as significant independent risk factors for 30-day complications or readmission after RTSA (p ≤ 0.05). Having at least one significant risk factor was associated with 2.71 times risk of complication or readmission within 15 days compared to having no risk factors (p < 0.001). The majority of unplanned readmission, return to the operating room, open/deep wound infection, and sepsis/septic shock occurred within two weeks of RTSA.

DISCUSSION

Patients at high risk of complications and readmission after RTSA should be identified and optimized preoperatively to improve outcomes and lower costs.

Preoperative indications for total shoulder arthroplasty predict adverse postoperative complications

BACKGROUND

Although studies have shown improved pain, function, and patient satisfaction after total shoulder arthroplasty (TSA), preoperative factors predicting poor outcomes are unexplored. Comparison of postoperative complications between osteoarthritis (OA), cuff arthropathy (CA), and fracture patients is important for identifying at-risk patients.

METHODS

Primary TSAs from 2014 to 2016 with preoperative OA, CA, and proximal humerus fractures as indications were queried from the National Surgical Quality Improvement Program database. Short-interval postoperative complications were compared using multivariate binary logistic regression, and postoperative time to discharge between groups was analyzed using univariate analysis of variance with Tukey comparison. Statistical significance was defined as P < .05 using SPSS software version 23.0 (IBM Corp., Armonk, NY, USA).

RESULTS

Of 9684 TSA cases, the primary indication was OA in 6571 patients, CA in 725 patients, and fractures in 646 patients. Compared with fractures, OA patients had statistically significant lower risk of dislocation, readmission, return to operating room, nonhome discharge, surgical site infection, perioperative bleeding requiring transfusion, and pulmonary embolism (all P < .05). Statistically significant lower risk of dislocation, nonhome discharge, and transfusion was also found between CA and fracture patients (all P < .03). However, in comparing CA vs. OA as preoperative indications, only postoperative venous thromboembolism (odds ratio, 4.5; P = .01) and surgical site infection (odds ratio, 3.7; P = .007) were significant. Mean differences in discharge time were significant between both OA and CA groups compared with fractures (P < .001), but there was no significance between OA and CA (P = .116).

CONCLUSION

Proximal humerus fracture is a risk factor for increased postoperative complications compared with OA and CA. With new outcomes-based reimbursement models, nonroutine discharge and increased discharge time should be considered in arthroplasty planning.

Reverse shoulder arthroplasty has a higher risk of revision due to infection than anatomical shoulder arthroplasty

Aims

The aim of this study was to use national registry database information to estimate cumulative rates and relative risk of revision due to infection after reverse shoulder arthroplasty.

Patients and Methods

We included 17 730 primary shoulder arthroplasties recorded between 2004 and 2013 in The Nordic Arthroplasty Register Association (NARA) data set. With the Kaplan–Meier method, we illustrated the ten-year cumulative rates of revision due to infection and with the Cox regression model, we reported the hazard ratios as a measure of the relative risk of revision due to infection.

Results

In all, 188 revisions were reported due to infection during a mean follow-up of three years and nine months. The ten-year cumulative rate of revision due to infection was 1.4% overall, but 3.1% for reverse shoulder arthroplasties and 8.0% for reverse shoulder arthroplasties in men. Reverse shoulder arthroplasties were associated with an increased risk of revision due to infection also when adjusted for sex, age, primary diagnosis, and year of surgery (relative risk 2.41 (95% confidence interval 1.26 to 5.59); p = 0.001).

Conclusion

The overall incidence of revision due to infection was low. The increased risk in reverse shoulder arthroplasty must be borne in mind, especially when offering it to men. Cite this article: Bone Joint J 2019;101-B:702–707.

Low revision rate despite poor functional outcome after stemmed hemiarthroplasty for acute proximal humeral fractures: 2,750 cases reported to the Danish Shoulder Arthroplasty Registry

Background and purpose - The revision rate of stemmed hemiarthroplasty (SHA) for acute proximal humeral fractures is low, but does not necessarily reflect the functional outcome. We report the revision rate of SHA for acute proximal humeral fractures and the proportion of arthroplasties that are not revised despite low functional outcome scores. Patients and methods - The Danish Shoulder Arthroplasty Registry was used to identify all patients with a proximal humeral fracture that was treated with a SHA between January 1, 2006 and December 31, 2015. Information on demographics, surgical procedures, and revisions was collected by the registry. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as functional outcome score. We converted the score to a percentage of a maximum score with 100 being the best. Results - 2,750 SHAs in 2,719 patients were included. Mean age was 72 years (SD 11); 79% were women. Mean WOOS at 1 year was 55 (SD 26). A total of 101 (4%) arthroplasties were revised, and the 10-year cumulative implant survival rate was 95%. The Cox regression model showed a statistically significant impact on implant survival of age, but not of sex or arthroplasty brand. A WOOS score below 30 and 50 was reported in 11% and 25% of patients, respectively. Interpretation - We found a high implant survival rate, but also a high proportion of patients with a low functional outcome score 1 year after surgery.

A population-based comparison of joint survival of hemiarthroplasty versus total shoulder arthroplasty in osteoarthritis and rheumatoid arthritis

Aims

Few studies have compared survivorship of total shoulder arthroplasty (TSA) with hemiarthroplasty (HA). This observational study compared survivorship of TSA with HA while controlling for important covariables and accounting for death as a competing risk.

Patients and Methods

All patients who underwent shoulder arthroplasty in Ontario, Canada between April 2002 and March 2012 were identified using population-based health administrative data. We used the Fine–Gray sub-distribution hazard model to measure the association of arthroplasty type with time to revision surgery (accounting for death as a competing risk) controlling for age, gender, Charlson Comorbidity Index, income quintile, diagnosis, and surgeon factors.

Results

During the study period, 5777 patients underwent shoulder arthroplasty (4079 TSA, 70.6%; 1698 HA, 29.4%), 321 (5.6%) underwent revision, and 1090 (18.9%) died. TSA patients were older (TSA mean age 68.4 years (sd 10.2) vs HA mean age 66.5 years (sd 12.7); p = 0.001). The proportion of female patients was slightly lower in the TSA group (58.0% vs 58.4%). The adjusted association between surgery type and time to shoulder revision interacted significantly with patient age. Compared with TSA patients, revision was more common in the HA group (adjusted-health ratio (HR) 1.214, 95% confidence interval (CI) 0.96 to 1.53) but this did not reach statistical significance.

Conclusion

Although there was a trend towards higher revision risk in patients undergoing HA, we found no statistically significant difference in survivorship between patients undergoing TSA or HA. Cite this article: Bone Joint J 2019;101-B:454–460.

Different acromial roof morphology in concentric and eccentric osteoarthritis of the shoulder: a multiplane reconstruction analysis of 105 shoulder computed tomography scans

BACKGROUND

The pathomechanisms of eccentric osteoarthritis of the shoulder remain unclear. Although there is increasing evidence of bony differences between shoulders with rotator cuff tears and osteoarthritis, analogous differences have not been identified for primary concentric and eccentric osteoarthritis. This study examined the shape and orientation of the acromial roof as a potential risk factor for the development of posterior glenoid wear.

METHODS

We analyzed computed tomography images of 105 shoulders with primary osteoarthritis. Based on the classification of Walch, 45 shoulders had concentric osteoarthritis (Walch A) and 60 shoulders were affected by eccentric osteoarthritis (Walch B; EOA). A comparison of acromial morphology was performed in a multiplanar reconstruction analysis of computed tomography scans.

RESULTS

Acromial shape: Acromial length, width, and area were not significantly different. Acromial roof orientation: The acromial roof in EOA was an average of 5° flatter (sagittal tilt; P < .01) and 5° more downward tilted (coronal tilt; P < .01). There was no difference in axial rotation (axial tilt; P = .47). Anteroposterior glenoid coverage: The glenoid in EOA was covered an average of 4° less posteriorly (P = .01) and 4° more anteriorly (P = .04). No differences were shown for overall glenoid coverage.

CONCLUSIONS

The acromial roof could play a role in the pathogenesis of EOA. Less posterior support due to a flatter acromion with less posterior glenoid coverage could contribute to static posterior subluxation of the humeral head and posterior glenoid wear. Further biomechanical investigations are needed to confirm these findings.

Novel exploration of customized 3D printed shoulder prosthesis in revision of total shoulder arthroplasty: A case report

RATIONALE

This paper describes the application of individual customized 3-dimensional (3D) printed macro-porous Ti6Al4 V shoulder prosthesis in the revision of total shoulder arthroplasty (TSA) for the patient with severe bone defects.

PATIENT CONCERNS

A 47-year-old male had been under proximal humeral resection and TSA due to shoulder chondrosarcoma 6 years ago, but a second surgery to insert a new prosthesis was then performed because the prosthesis became loose 2 months ago leaving severe bone defects which conventional prosthesis was not suitable for revision of TSA. American Shoulder and Elbow Surgeons' Form (ASES), Neer and Constant-Murley score were 36, 39, and 39, respectively.

DIAGNOSES

The patient was diagnosed with shoulder bone defects and restriction of the shoulder movement.

INTERVENTIONS

3D printed shoulder model and computer-aided design (CAD) were used for prosthesis design and surgical simulation. The novel 3D printed titanium alloy shoulder prosthesis was customized subsequently to be used in the revision of TSA. The patient was followed up regularly after surgery. The ASES, Neer Shoulder score and Constant-Murley Shoulder score were evaluated during pre-operation, post-operation, and follow-up.

OUTCOMES

Prosthesis was successfully implanted to complete anatomic reconstruction intraoperatively. The scores of ASES, Neer, and Constant-Murley were gradually increased after the operation. According to the X-ray, the bone healed satisfactorily without change of prosthetic position at 3rd and 12th months after the operation. The function of shoulder could meet the requirements of daily activities.

LESSONS

The application of customized 3D printed titanium alloy shoulder prosthesis in the revision of TSA achieves satisfactory results. It provides a novel method for the similar revision surgery with severe bone defects.

Neuropathic Pain after Shoulder Arthroplasty: Prevalence, Impact on Physical and Mental Function, and Demographic Determinants

Purpose: The objectives of this survey study were to provide an estimate of the prevalence of neuropathic pain (NP) and to explore the cross-sectional and longitudinal group differences postoperatively. Method: A cohort of consecutive patients who had undergone total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), or humeral head replacement (HHR) were surveyed within an average of 3.8 years after surgery. Questionnaires completed at the time of the survey were the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale, the visual analogue scale (VAS) for pain, the Western Ontario Osteoarthritis of the Shoulder (WOOS) index, the Patient Health Questionnaire-9 (PHQ-9), and a satisfaction questionnaire. Results: Of the 141 candidates who were invited to participate in the study, 115 patients participated (85 TSA, 21 HHR, and 9 RSA), for an 82% response rate. Five patients (4%) met the criteria for NP, of whom one had a loosening of the prosthesis and required further surgery. Having NP was associated with greater pain (VAS; p=0.001), greater depression (PHQ-9; p=0.001), more disability (WOOS; p=0.030), and less satisfaction with the surgery (p=0.014). There was no relationship between the presence of NP and patients' age, sex, preoperative pain, range of motion results, or WOOS scores (p>0.05). Conclusions: Persistent pain of neuropathic origin is not common after shoulder arthroplasty, but it is a significant contributor to poor mental and physical well-being and thus warrants further research.