Outcomes and complications of primary reverse shoulder arthroplasty with minimum of 2 years' follow-up: a systematic review and meta-analysis

CT imaging findings in symptomatic patients with and without revision surgery after reverse shoulder arthroplasty

OBJECTIVES

To evaluate CT imaging findings in symptomatic patients with and without revision surgery (RS) after reverse shoulder arthroplasty (RSA).

MATERIALS AND METHODS

In this retrospective study, two radiologists assessed CT imaging findings in symptomatic patients with RSA over 5 years, including material fracture and loosening of the peg, baseplate, screws, and humeral stem, screw positioning, prosthesis dislocation, glenoid notching, fractures, and deltoid muscle quality. The primary outcome parameter was RS. Patients were assigned Group 1 (RS) or Group 2 (No RS).

RESULTS

Ninety-nine patients (mean age 70.4 ± 10.3 years, 61 females) met the inclusion criteria. Fifty-two patients (29 females) received RS after 34.0 ± 38.3 months. The only CT imaging finding significantly associated with RS was prosthesis dislocation (P = .007, odds ratio (OR) 10.95, 95% CI 1.34-89.24). All other evaluated CT imaging findings were not associated with RS. Yet, loosening of the peg (30% vs. 16%), baseplate (15% vs. 6%), and superior screw (18% vs. 7%) and periprosthetic humeral fractures (29% vs. 13%)-as common reasons for RS-were more frequent in patients with RS than in those without, however not reaching significance (P ≥ .11). The large majority of patients had glenoid notching (79% vs. 94%), irrespective of RS.

CONCLUSION

In this cohort of symptomatic patients after RSA, prosthesis dislocation was the only CT imaging finding associated with RS. Besides, there was a trend with higher numbers of loosening of the peg, baseplate, and superior screw, as well as periprosthetic humeral fractures in patients with RS, though not reaching significance.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparing the Exactech Equinoxe reverse total shoulder arthroplasty for fracture versus degenerative conditions: 5-year minimum follow-up

BACKGROUND/HYPOTHESIS

Reverse total shoulder arthroplasty (rTSA) has become the operative treatment of choice for acute proximal humerus fractures in the elderly population, but little data exist on the long-term outcomes or how they compare to rTSA done for degenerative conditions. The purpose of this study is to compare the clinical and radiographic outcomes of patients undergoing rTSA for acute fracture versus degenerative conditions with a minimum 5-year follow-up.

METHODS

Data was extracted from an international registry of patients with the Exactech Equinoxe rTSA implant from 2007 to 2018. Patients with a minimum follow-up of 5 years were then split into fracture and degenerative cohorts and matched 1:3 based on age, sex, and follow-up duration. Clinical and radiographic outcomes were compared between the cohorts including range of motion, patient-reported outcome measures, visual analouge scale pain score, complication and revision rates, implant characteristics, and scapular notching. This data was analyzed using Welch's t-test, Fisher's exact test, or Wilcoxon rank sum test.

RESULTS

There were 384 total patients included in the study, with 96 fractures and 288 degenerative. At a mean follow-up of 6.4 years, the degenerative cohort had significant improvements in all patient-reported outcome measures and range of motion, compared to their preoperative status. At the latest follow-up, the mean American Shoulder and Elbow Surgeons score was 83 and the mean visual analouge scale pain score was 1.1 for both cohorts. Patients with degenerative indications had greater forward elevation which did not meet the minimally clinically important difference and greater internal rotation which did not meet the substantial clinical benefit threshold. Patient satisfaction was very high for both cohorts, with 97% in the degenerative cohort and 91% in the fracture cohort satisfied with the procedure (P = .276). Complication and revision rates were similar between the 2 cohorts. Patients in the fracture cohort had a larger glenosphere diameter (P = .045) and greater combined liner/tray offset (P = .05). Patients in the elective cohort more frequently required an augmented baseplate (P < .001). Scapular notching was 11% in the degenerative cohort and 9% in the fracture cohort (P = .82).

CONCLUSION

This study demonstrates no significant differences in the clinical or radiographic outcomes at a minimum of 5 years follow-up for patients undergoing rTSA for acute fracture versus degenerative conditions. Patients undergoing rTSA for either indication have similar rates of complications, revisions, and scapular notching, with high patient satisfaction. Patients undergoing rTSA for an acute fracture can expect similar results to those undergoing rTSA for degenerative conditions at minimum 5-year follow-up.

Prosthetic treatment of proximal humerus fractures in the elderly

The Section for Skeletal Trauma and Sports Injuries of the European Society for Trauma and Emergency Surgery (ESTES) has reached a consensus among European countries in the treatment of proximal humerus fractures in a working group. As a result the ESTES recommendations on proximal humerus fractures in the elderly were published in 2021. The various treatment options and algorithms for this are now described in more detail and the procedures were explained in several related specialist articles. The recommendations include conservative and four possible surgical treatment options (ORIF, nailing, hemi- and total inverse arthroplasty). This article deals with hemi- and total inverse arthroplasty. Reverse total shoulder arthroplasty (RTSA) has emerged as a key treatment for complex proximal humerus fractures in elderly patients. It offers significant advantages in restoring function, alleviating pain, and providing durable outcomes compared to alternative approaches. Despite challenges related to implant complications and surgical expertise, ongoing advancements in technology and techniques continue to improve its effectiveness. With the rising incidence of complex fractures, RTSA is expected to play an increasingly vital role in maintaining the quality of life in aging populations.

Complications after reverse total shoulder arthroplasty in the Korean population: a single center study of 299 cases

BACKGROUND

Knowledge regarding differences in the order of frequency of complications after reverse total shoulder arthroplasty (rTSA) between Asian and Western populations is limited. We therefore asked for (1) what is the order of frequency of complications after primary rTSA in the Korean population? (2) What are the rates of complication, reoperation, and revision, and clinical outcomes after index surgery?

METHODS

We retrospectively reviewed the 299 consecutive cases who underwent primary rTSA with more than 1 year of follow-up over a period of 12 years. The mean age of the patients was 73.4 years (range, 58-88 years) and the mean follow-up period was 3.8 years (range, 1-11.5 years). Evaluation of the clinical outcomes, complications, and reinterventions was performed at the final follow-up.

RESULTS

The mean visual analog scale pain score, University of California at Los Angeles score, American Shoulder and Elbow Surgeons score, and subjective shoulder value improved from 6.7, 10.2, 30.7, and 27.7% before rTSA to 1.4, 26.4, 80.5, 77.2% after rTSA, respectively (P < .001). Overall, 45 complications (15.1%) were observed in 44 patients. The order of frequency of complications was as follows: 16 cases of scapular stress fracture (5.4%), 9 intraoperative or postoperative periprosthetic fracture (3.0%), 6 brachial plexus injury (2.0%), 4 instability (1.3%), 2 glenoid loosening (0.7%), 2 glenoid disassembly (0.7%), 2 periprosthetic joint infection (0.7%), 1 glenoid fixation failure (0.3%), 1 humeral stem fixation failure (0.3%), 1 hematoma (0.3%), and 1 complex regional pain syndrome (0.3%). Reintervention was performed in 15 cases (5.0%) including reoperation (8 cases; 2.7%) and revision surgery (7 cases; 2.3%).

CONCLUSION

At a mean follow-up period of 3.8 years, primary rTSA showed satisfactory clinical outcomes with a complication rate of 15.1%, a reoperation rate of 2.7%, and a revision rate of 2.3%. Scapular stress fracture appears to be the most common complication after rTSA in the Korean population.

Stemless reverse total shoulder arthroplasty: a systematic review and meta-analysis

Background

Stemless reverse total shoulder arthroplasty (rTSA) is one of the many modifications of the original Grammont rTSA design. Much has been made of the debate between stemless and stemmed humeral implants for anatomic reverse shoulder arthroplasty, with less attention awarded to the relatively newer variation in stemless rTSA. Proposed advantages of said design include preserving bone stock, ease of revision, reduced blood loss, and shortening surgical times.

Methods

A systematic search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using search engines in PubMed, EMBASE, and Cochrane to retrieve all relevant studies.

Results

Initial search strategies produced 174 studies, of which 15 studies were included for full analysis in this review. This included 657 shoulders in 648 patients (9 bilateral cases). Stemless rTSA led to significant improvement in functional outcomes and range of motion (ROM) across all studies. Meta-analysis of comparative studies including stemless and stemmed rTSA showed no significant difference in ROM measurements across abduction (standardized mean difference [SMD] -0.17, 95% confidence interval [CI]: -1.05, 0.70) or forward flexion (SMD -0.36, 95% CI: -1.23, 0.50). However, there was a statistically significant difference in internal rotation in favor of stemless implants (SMD -0.79, 95% CI: -1.56, -0.03). There was no significant difference in visual analog scale (VAS) between stemmed and stemless designs (SMD -0.31, 95% CI: -2.32, 1.69). Likewise, there was no significant difference in odds ratio (OR) for revision rates (OR: 1.02, 95% CI: 0.92, 1.14) or overall complications (OR: 0.82, 95% CI: 0.2, 3.42). Across all 15 studies, comparative and noncomparative studies, overall complication rates for stemless rTSA stood at 13.4% and revision rates at 5.5%.

Conclusion

Stemless rTSA achieves similar functional outcomes to stemmed rTSA designs. Stemless designs achieved superior internal rotation in the comparative studies. Proposed advantages of stemless rTSA including reduced blood loss and lesser surgical times need further research, as does the long-term robustness of this relatively novel design.

The Evolution of Reverse Shoulder Arthroplasty: A Review of Complications and the Rising Concern of Overuse

Reverse shoulder arthroplasty (RSA) was initially developed to manage cuff tear arthropathy in elderly patients. It has since become increasingly popular due to its ability to provide pain relief, enhance stability, and improve function in various complex shoulder pathologies. This review examines the evolution of RSA, including its expanded indications for use, complications, and the rising concern of potential overuse. While RSA has shown significant benefits in selected cases, its growing application in younger and more active patients raises questions about long-term outcomes and durability. Complications such as instability, infection, baseplate failure, and scapular notching remain substantial challenges, particularly in revision cases. The article emphasises the need for cautious patient selection and evidence-based practice to avoid overuse and ensure optimal patient outcomes. Future high-quality research with extended follow-up is essential to better understand RSA's long-term efficacy and safety, particularly in diverse and younger patient populations.

Survivorship and clinical outcomes of reverse total shoulder arthroplasty in patients with large glenoid defects using the stilting technique and a baseplate with central ingrowth cage and peripheral locking screws

BACKGROUND

Stilting is a novel technique used in reverse shoulder arthroplasty (RSA) in patients with significant glenoid bone loss. This technique utilizes peripheral locking screws placed behind an unseated portion of the baseplate to transmit forces from the baseplate to the cortical surface of the glenoid, without the need for bone grafting. The stilted screw, once locked, provides a fixed angle point of support for this unseated aspect of a baseplate. The primary advantages of this technique are reduced cost compared to a custom implant and reduced operative time compared to bone grafting.

METHODS

We conducted a retrospective, nonrandomized, comparative cohort study of 41 patients who underwent primary RSA using the stilting technique with the Exactech Equinoxe Reverse System (Gainesville, FL, USA) at a single academic center from the years 2004 to 2021. Exclusion criteria included age under 18 or over 100 and oncologic or acute fracture RSA indications. Operative data was documented, including implant records, percent baseplate seating, and operative duration. Survivorship was compared among primary stilted RSA (n = 41), bone grafted RSA (n = 42), and non-stilted/non-bone grafted RSA (n = 1032) within our institutional shoulder arthroplasty database. A radiographic examination of baseplate failure was also conducted across the study groups. Postoperative functional outcomes were compared in a matched analysis involving patients with a minimum 2-year follow-up between stilted patients and a non-stilted/non-bone grafted control group for primary RSA.

RESULTS

All stilted RSA cases utilized metal augments and demonstrated a mean baseplate seating of 61% (range 45%-75%). For stilted RSAs, survivorship was 100% and 92.6% at 2 years and 5 years, compared to 98.3% and 94.6% for non-stilted/non-bone grafted and 96.3% and 79.5% for bone grafted RSAs (P = .042). At 5 years, the baseplate-related failure rates were greater in the stilted (7.4%) and the bone-grafted (9.3%) cohorts compared with the non-stilted/non-bone grafted cohort (1.1%, P < .001). The mean time to baseplate failure was 30 months for stilted RSA. Functional outcomes for primary RSA were statistically similar between stilted and non-stilted patients, including range of motion, Constant, American Shoulder and Elbow Surgeons, Simple Shoulder Test, University of California, Los Angeles, and Shoulder Pain and Disability Index scores.

CONCLUSION

The stilted RSA cohort exhibited noninferior revision and baseplate failure rates to that of bone grafted RSA. This suggests that stilting may be a viable technique for patients undergoing primary RSA with significant glenoid deformity.

Implantation of Reverse Shoulder Endoprothesis Using Navigation

Die Implantation einer inversen Schulterendoprothese (TEP) stellt eine bewährte Methode zur Schmerzlinderung und Schulterfunktionsverbesserung dar. Die Ergebnisse variieren je nach Patientenalter, Krankheitsgrad und Erfahrung des Operateurs. Indikationen für eine inverse TEP sind vielfältig, von der Defektarthropathie bis hin zu Frakturen. Aktuelle Studien zeigen verbesserte Überlebensraten und reduzierte Komplikationen nach primärer Implantation. Die präoperative Planung mittels 3-D-CT oder MRT gilt als Goldstandard. Patientenspezifische Instrumente (PSI) wurden eingeführt, sind jedoch mit Kosten und Wartezeit verbunden. Die Navigation mit "Augmented Reality" (AR) bietet eine effizientere Alternative. Die intraoperative Übertragung der Planung auf den Patienten erfolgt über AR-Brillen und ermöglicht Echtzeitinformationen, wodurch der Chirurg den Blick vom Situs nicht abwenden muss. Dies optimiert den Workflow und bietet potenziell präzisere Implantationsresultate. Zusammenfassend bietet die Kombination von 3-D-Planung, Navigation und AR eine vielversprechende Methode für präzise und effiziente Implantationen von inversen Schulterendoprothesen. Allerdings steht der Nachweis verbesserter Standzeiten und Funktionsscores noch aus.

Anatomic or reverse shoulder arthroplasty for cuff intact glenohumeral osteoarthritis

Glenohumeral osteoarthritis in the presence of an intact rotator cuff is a debilitating condition that often leads to surgical intervention in the form of joint arthroplasty. Historically, anatomic total shoulder replacement (ATSR) had been considered the treatment of choice. Over the past decade, however, there has been a shift in treatment patterns to the use of reverse shoulder replacement to treat this condition due to concerns of subsequent rotator cuff failure and glenoid component loosening with ATSR. With continued innovation of implants and surgical techniques, it is unclear which procedure provides the best outcomes for patients. The Reverse or Anatomical replacement for Painful Shoulder Osteoarthritis, Differences between Interventions trial aims to definitively answer this question and evaluate the cost effectiveness of both procedures.

A novel methodology for establishing minimum clinically important difference and substantial clinical benefit thresholds for patient-reported outcome measures following reverse total shoulder arthroplasty

BACKGROUND

Increasing reliance on patient-reported outcome measures (PROMs) following reverse total shoulder arthroplasty (rTSA) has resulted in variability in the thresholds for minimum clinically important difference (MCID) and substantial clinical benefit (SCB) reported in the literature. In this study, we aimed to identify the best threshold values for MCID and SCB for common rTSA PROMs.

METHODS

The PubMed, Embase, MEDLINE, Cochrane Library, and Google Scholar databases were queried for studies published from January 1, 2000 to March 1, 2024 that identified clinically significant thresholds for PROMs following rTSA. The threshold calculation method, anchor questions/response options, follow-up duration, and confidence intervals were extracted. A novel hierarchical methodology evaluated various threshold calculation characteristics to identify the best MCID and SCB values following rTSA.

RESULTS

We included 37 studies for analysis comprising 11,960 patients. Using our methodology, the MCID values from the literature we recommend for American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), Constant-Murley Shoulder Outcome Score (Constant), University of California at Los Angeles Shoulder Score (UCLA), Shoulder Pain and Disability Index (SPADI) score, and Visual Analog Scale (VAS) following rTSA are 8.9, 3.7, 9.3, 2.9, 20, and 1.4, respectively. The recommended MCID threshold values for ASES and SST were from Werner and McLaughlin, respectively. The recommended thresholds for Constant and UCLA were from Zhou, while the thresholds for SPADI and VAS were from Simovitch. Using our methodology, the SCB threshold values from the literature we recommend for ASES following rTSA are 28.3 for glenohumeral osteoarthritis and 23.1 for rotator cuff arthropathy from Puzzitiello. For SST, Constant, UCLA, SPADI, and VAS, the SCB values we recommend are 3.2, 13.6, 10.4, 42.7, and 2.6, respectively. The recommended SCB thresholds for SST, Constant, UCLA, SPADI, and VAS were all from Simovitch.

CONCLUSION

We present recommended MCID and SCB values identified through our comprehensive methodology and recommend how these thresholds should be calculated for common rTSA PROMs moving forward. With increasing use and dependence on MCID and SCB values for PROMs, these recommended threshold values for MCID and SCB will help standardize assessment of clinically significant improvement for patients undergoing rTSA.

From Grammont to a New 135° Short-Stem Design: Two-Hand Lever Test and Early Superior-Lateral Dislocations Reveal Critical Role of Liner Stability Ratio and Stem Alignment

Background: In reverse shoulder arthroplasty (RSA), the neck-shaft angle (NSA) has trended downward from 155° to 135° to reduce scapular notching, but concerns about instability persist. To assess superior-lateral stability, we developed the intraoperative two-hand lever test (2HLT). The primary objective was to evaluate the effectiveness of the 2HLT, analyze the learning curve in this first study reporting on the new Perform stem, and compare the liner characteristics of 155° and 135° systems. Methods: In a single-surgeon learning curve study, 81 RSA procedures with the new Perform stem (Stryker) were included. The outcomes included the 2HLT test applied in 65 cases, early dislocations, stem alignment, stem length, liner type/thickness, and complications. The early dislocation rate was compared to 167 prior Ascend Flex RSA procedures (Stryker). The liner characteristics of three 135° systems (Perform/Stryker, Univers/Arthrex, and Altivate/Enovis) were compared to traditional 155° Grammont systems (Delta Xtend/DePuy, Affinis Metal/Mathys, SMR 150/Lima, and Aequalis Reversed/Stryker), focusing on jump height (JH) and the liner stability ratio (LSR). Results: In 63% (31/49) of the cases, the 2HLT detected superior-lateral instability, necessitating a retentive 135° liner. The early dislocation rate in the Perform cohort was 4.9% (0% for retentive liners, 8% for standard liners) versus 0% in the Ascend Flex cohort. The mean effective NSA was 133° (127-144°) for short Perform stems and 135° (129-143°) for long stems. Long Perform stems significantly reduced varus outlier density below 132° and 130° (p = 0.006, 0.002). The 36 mm Perform 135° standard liner has a JH of 8.1 mm and an LSR of 152%, markedly lower than the Altivate (10.0 mm/202%) and Univers (9.7 mm/193%) and similar to traditional 155° Grammont liners (8.1-8.9 mm/147-152%). Perform retentive liners have LSR values of 185-219%, comparable to the established 135° design standard liners (195-202%). In the Perform cohort, early complications included four superior-lateral dislocations (all standard liners, LSR 147-152%) requiring four revisions. Conclusions: Perform standard liners have a lower LSR than the established 135° designs. Retentive Perform liners (LSR > 184%) are comparable to standard liners of established 135° designs and effectively mitigate instability. We recommend discontinuing non-retentive Perform standard liners (NSA 135°, LSR < 158%) due to the 63% superior-lateral instability rate detected with the novel 2HLT, necessitating retentive liners, the documented LSR-NSA implant mismatch, and an early clinical dislocation rate of up to 8%.

Predictive factors of intraoperative conversion to reverse total shoulder arthroplasty in patients with primary glenohumeral arthritis

Background

Many factors play a role in decision making for arthroplasty type in patients with glenohumeral osteoarthritis (GHOA). The purpose of this study was to evaluate preoperative and intraoperative factors that might predict the need for reverse total shoulder arthroplasty (rTSA) vs. anatomic total shoulder arthroplasty (aTSA) for patients with primary GHOA. Secondarily, American Shoulder and Elbow Surgeons (ASES) were compared.

Methods

Patients with primary GHOA indicated for aTSA vs. rTSA were identified. Preoperative records were reviewed for demographics, range of motion, rotator cuff strength, and glenoid morphology. Operative reports were assessed to identify intraoperatively rotator cuff pathology and glenoid deficiency. ASES scores at 2 years postoperative were collected.

Results

One hundred eleven patients were included from 2018 to 2021. Ninety-four patients underwent aTSA, while 17 were intraoperatively converted to rTSA. There were no significant differences in age, body mass index, or preoperative Walch classification between cohorts. rTSA patients had significantly decreased preoperative external rotation (P = .006). External rotation ≤30° was the only preoperative predictive factor for performing rTSA vs. aTSA (P = .0004). The most common reason for intraoperative transition to rTSA was rotator cuff deficiency. At 2-year follow-up, median ASES scores were 94.2 (interquartile range 85-96.7) and 88.3 (interquartile range 73.3-94.5) for aTSA and rTSA, respectively (P = .097).

Conclusion

Many patients with primary GHOA are well-served with aTSA. However, there are patients with primary GHOA in which rTSA may be ideal given rotator cuff deficiency or glenoid defects felt to limit aTSA glenoid component placement. This study highlights the need for preoperative external rotation and intraoperative evaluation of rotator cuff integrity and glenoid bone stock.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Machine Learning Algorithms and Hybrid Computational Intelligence Algorithms for Rehabilitation Classification and Prognosis in Reverse Total Shoulder Arthroplasty

Despite the increasing application of machine learning and computational intelligence algorithms in medicine and physiotherapy, accurate classification and prognosis algorithms for postoperative patients in the rehabilitation phase are still lacking. The present study was carried out in two phases. In Phase I, classification performance of simple machine learning algorithms applied on data of patients suffering of reverse total shoulder arthroplasty (RTSA), examining algorithms' classification accuracy and patients' rehabilitation prognosis. In Phase II, hybrid computational intelligence algorithms were developed and applied in order to search for the minimum possible training set that achieves the maximum classification and prognostic performance. The data included features like age and gender, passive range of available motion of all movements (preoperative and postoperative), visual analog pain scale (preoperative and postoperative), and total rehabilitation time. In Phase I, K-nearest neighbors (ΚΝΝ) classification algorithm and K-means clustering algorithm (GAKmeans) were applied. Also, a genetic algorithm (GA)-based clustering algorithm (GAClust) was also applied. To achieve 100% performance on the test set, KNN used 80% of the data in the training set, whereas K-means and GAClust used 90% and 53.3%, respectively. In Phase II, additional computational intelligence algorithms were developed, namely, GAKNN (Genetic Algorithm K-nearest neighbors), GAKmeans, and GA2Clust (genetic algorithm-based clustering algorithm 2), for genetic algorithm optimization of the training set. Genetic algorithm optimization of the training set using hybrid algorithms in Phase II resulted in 100% performance on the test set by using only 35% of the available data for training. The proposed hybrid algorithms can reliably be used for patients' rehabilitation prognosis.

The relationship between design-based lateralization, humeral bearing design, polyethylene angle, and patient-related factors on surgical complications after reverse shoulder arthroplasty: a machine learning analysis

BACKGROUND

Technological advancements in implant design and surgical technique have focused on diminishing complications and optimizing performance of reverse shoulder arthroplasty (rTSA). Despite this, there remains a paucity of literature correlating prosthetic features and clinical outcomes. This investigation utilized a machine learning approach to evaluate the effect of select implant design features and patient-related factors on surgical complications after rTSA.

METHODS

Over a 16-year period (2004-2020), all primary rTSA performed at a single institution for elective and traumatic indications with a minimum follow-up of 2 years were identified. Parameters related to implant design evaluated in this study included inlay vs. onlay humeral bearing design, glenoid lateralization (medialized or lateralized), humeral lateralization (medialized, minimally lateralized, or lateralized), global lateralization (medialized, minimally lateralized, lateralized, highly lateralized, or very highly lateralized), stem to metallic bearing neck shaft angle, and polyethylene neck shaft angle. Machine learning models predicting surgical complications were constructed for each patient and Shapley additive explanation values were calculated to quantify feature importance.

RESULTS

A total of 3837 rTSA were identified, of which 472 (12.3%) experienced a surgical complication. Those experiencing a surgical complication were more likely to be current smokers (Odds ratio [OR] = 1.71; P = .003), have prior surgery (OR = 1.60; P < .001), have an underlying diagnosis of sequalae of instability (OR = 4.59; P < .001) or nonunion (OR = 3.09; P < .001), and required longer OR times (98 vs. 86 minutes; P < .001). Notable implant design features at an increased odds for complications included an inlay humeral component (OR = 1.67; P < .001), medialized glenoid (OR = 1.43; P = .001), medialized humerus (OR = 1.48; P = .004), a minimally lateralized global construct (OR = 1.51; P < .001), and glenohumeral constructs consisting of a medialized glenoid and minimally lateralized humerus (OR = 1.59; P < .001), and a lateralized glenoid and medialized humerus (OR = 2.68; P < .001). Based on patient- and implant-specific features, the machine learning model predicted complications after rTSA with an area under the receiver operating characteristic curve of 0.61.

CONCLUSIONS

This study demonstrated that patient-specific risk factors had a more substantial effect than implant design configurations on the predictive ability of a machine learning model on surgical complications after rTSA. However, certain implant features appeared to be associated with a higher odd of surgical complications.

Inconsistencies in measuring glenoid version in shoulder arthroplasty: a systematic review

BACKGROUND

Glenoid version is a critical anatomic parameter relied upon by many surgeons to inform preoperative planning for shoulder arthroplasty. Advancements in imaging technology have prompted measurements of glenoid version on various imaging modalities with different techniques. However, discrepancies in how glenoid version is measured within the literature have not been well characterized.

METHODS

A literature search was performed by querying PubMed, EMBASE, CINAHL, and Cochrane computerized databases from their inception through December 2023 to identify studies that assessed the relationship between preoperative glenoid version and at least one clinical or radiologic outcome following shoulder arthroplasty. Study quality was assessed via the Methodologic Index for Nonrandomized Studies criteria. Imaging modalities and techniques for measuring glenoid version, along with their association with clinical outcomes, were aggregated.

RESULTS

Among 61 studies encompassing 17,070 shoulder arthroplasties, 27 studies (44.3%) described explicitly how glenoid version was measured. The most common imaging modality to assess preoperative glenoid version was computed tomography (CT) (63.9%), followed by radiography (23%); 11.5% of studies used a combination of imaging modalities within their study cohort. Among the studies using CT, 56.5% utilized two-dimensional (2D) CT, 41.3% utilized three-dimensional (3D) CT, and 2.2% used a combination of 2D and 3D CT. The use of 3D CT increased from 12.5% of studies in 2012-2014 to 25% of studies in 2018-2020 to 52% of studies in 2021-2023 (ptrend = 0.02). Forty-three (70.5%) studies measured postoperative version, most commonly on axillary radiograph (22 [51.2%]); 34.9% of these studies used different imaging modalities to assess pre- and postoperative version.

CONCLUSIONS

This systematic review revealed marked discrepancies in how glenoid version was measured and reported in studies pertaining to shoulder arthroplasty. A temporal trend of increased utilization of 3D CT scans and commercial preoperative planning software was identified. Improved standardization of the imaging modality and technique for measuring glenoid version will enable more rigorous evaluation of its impact on clinical outcomes.

Whether the Indications for Reverse Shoulder Arthroplasty Should Continue to Be Expanded? A Systematic Review and Meta-Analysis

BACKGROUND

It is still unclear whether reverse total shoulder arthroplasty (RTSA) has advantages over traditional hemiarthroplasty (HA) and anatomic total shoulder arthroplasty (ATSA) in the treatment of complex shoulder joint diseases. Therefore, this study aims to evaluate the clinical effectiveness of RTSA in the treatment of complex shoulder joint diseases and further determine whether it is necessary to expand the indications of RTSA.

METHOD

We conducted a systematic search of studies published between January 1, 2012 and May 31, 2023 in PubMed, Embase, and Cochrane databases. The experimental group included patients who underwent primary reverse total shoulder arthroplasty (RTSA), while the control group consisted of patients who underwent primary hemiarthroplasty (HA) or anatomic total shoulder arthroplasty (ATSA). The minimum follow-up period was 1 year, and a random-effects model was utilized for data synthesis.

RESULTS

A total of 45 studies were included in the meta-analysis. Compare to HA, RTSA showed significant advantages in postoperative ASES scores (p = 0.004), forward flexion (p < 0.0001), and abduction (p < 0.0001). Compare to ATSA, RTSA showed significantly lower postoperative Constant scores (p = 0.004), ASES scores (p = 0.001), SST scores (p < 0.0001), forward flexion (p < 0.0001), abduction (p = 0.011), internal rotation (p < 0.0001), and external rotation (p < 0.0001). Further meta regression analysis was conducted, considering factors such as region, age, gender ratio, and follow-up time, excluding the influence of relevant factors. Overall, RTSA did not demonstrate advantages in postoperative functional scores and range of motion. In terms of complication and revision rates, RTSA had lower rates compared to HA and ATSA, except for the complication rate, where there was no significant difference between RTSA and ATSA (p = 0.521), but statistically significant differences were observed in other measures.

CONCLUSION

RTSA demonstrates better clinical efficacy compared to HA but is inferior to ATSA. It can be considered for expanding treatment options for elderly patients with 3 or 4-part proximal humeral fractures, but it is not suitable for treating end-stage shoulder arthritis and humeral head necrosis. Overall, the decision to use RTSA should be carefully evaluated based on the extent of the patient's rotator cuff injury.

Reverse shoulder arthroplasty in the setting of massive proximal humeral bone loss: a systematic review

BACKGROUND

Massive proximal humeral bone loss (PHBL) poses a technical challenge during reverse shoulder arthroplasty (RSA). Surgical treatment strategies include allograft-prosthetic composite (APC) reconstructions, endoprostheses, and other reverse shoulder arthroplasty constructs; however, there is a paucity of literature summarizing the outcomes and complications unique to this complex patient population. This study aimed to systematically review the literature to evaluate (1) patient-reported outcome measures, (2) functional outcomes, and (3) complications according to surgical treatment strategy for patients with massive PHBL who undergo primary or revision shoulder arthroplasty.

METHODS

A systematic review of the PubMed/MEDLINE, Embase, and Cochrane databases was performed to identify studies reporting clinical outcomes and complications of reverse shoulder arthroplasty in patients with significant PHBL. Methodological quality was assessed for included studies. Patient-reported outcome measures, radiographic outcomes, and postoperative functional outcomes were collected.

RESULTS

Eleven studies evaluating clinical outcomes and complications of reverse shoulder arthroplasty in the setting of PHBL comprising 277 patients were included for review. The mean age was 66 years (range, 60-79 years). American Shoulder and Elbow Surgeons score, Visual Analog Scale, and range of motion were the most common outcomes collected, and patients exhibited significant improvements in mean scores postoperatively. Of the types of prostheses reported, there were 155 reverse shoulder arthroplasty (RSA) with allograft-prosthetic composite (APC) reconstructions, 48 proximal humeral replacement (PHR) endoprostheses, 41 RSA, 15 custom RSA, and 2 RSA with fibular strut allografts. The overall pooled complication rate was 30.1% (82/272) with revision/reoperation as the most common complication at 21% (57/272). The overall complication rate for RSA-APC reconstructions was 51% (79/155). The overall complication rate for PHR endoprostheses was 64.6% (31/48). Revision/reoperation rates were the most complication for both RSA-APC and PHR endoprostheses with rates of 20% and 31.3%, respectively.

CONCLUSIONS

Treatment by APC reconstruction is the most common surgical technique described in the setting of massive PHBL. While shoulder arthroplasty can yield acceptable results for patients with substantial PHBL, such patients are at increased risk for complications and revision surgery.

Which patient level factors predict persistent pain after reverse total shoulder arthroplasty?

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is commonly performed to reduce pain and restore shoulder function in patients with severe shoulder conditions. While most patients experience significant pain relief and functional improvement following surgery, a subset of patients continue to report persistent pain even two years postoperatively. The aim of this study was to identify both modifiable and non-modifiable preoperative factors that contribute to the risk of persistent postsurgical pain after RTSA. By understanding these factors, clinicians can better anticipate which patients are at higher risk and develop tailored preoperative and postoperative pain management strategies to improve overall outcomes.

METHODS

In this retrospective cohort study, 703 patients with complete data undergoing primary RTSA performed between 2011 and 2022 were analyzed. Persistent postsurgical pain was defined as a pain score ≥ 3 on a numeric rating scale. Multivariable regression models were used to identify patient-related and disease-related predictors of persistent postsurgical pain.

RESULTS

The cohort comprised 445 women (63%) and 258 men (37%) with a mean age of 74 ± 8 years at the time of surgery. Persistent postsurgical pain was reported by 18% of patients. Preoperative pain scores averaged 6.0 ± 2.5 on the NRS scale, which decreased to 1.2 ± 1.8 postoperatively. Key predictors included higher preoperative pain levels (β = 0.10, p < 0.001), worse preoperative QuickDASH scores (β = 0.09, p = 0.002), mild symptoms of anxiety or depression (β = 0.52, p = 0.001), prior contralateral TSA surgery (β = 0.34, p = 0.018) and greater number of previous ipsilateral shoulder surgeries (β = 0.44, p < 0.001). In contrast, patients with rheumatoid arthritis (β = - 0.85, p < 0.001) or primary osteoarthritis (β = - 0.82, p < 0.001) experienced lower pain levels.

CONCLUSION

Our study offers important insights into the predictors of persistent postsurgical pain two years after RTSA. Key factors, including higher preoperative pain scores, poor mental health, elevated QuickDASH scores, prior contralateral TSA surgery and a history of prior ipsilateral shoulder surgeries, were identified as significant risk indicators for persistent postsurgical pain.

Minimum two-year follow-up of a reverse total shoulder arthroplasty using a wedged baseplate

Background

Avoiding inclination of the glenoid baseplate in reverse shoulder arthroplasty often requires considerable glenoid reaming. It is proposed that the use of a metal wedged baseplate in all patients can achieve neutral inclination with reduced glenoid reaming.

Materials and Methods

A prospective clinical single-centre study with minimum two-year follow-up was carried out. Glenoid deformity was classified on CT and surgery planned using BluePrintTM. The Tornier Perform® Reversed Wedged Augmented Glenoid was used in all cases. Clinical outcome scores and radiographs were assessed.

Results

Seventy-three patients, mean age 76.6 years. Twenty-eight demonstrated no glenoid deformity and 19 demonstrated marked retroversion. Seventy completed two-year follow-up. Mean pain scores fell from 6 to 0.7. All Patient Reported Outcome Meaures (PROMS) were significantly improved. Active elevation increased by 62° and external rotation by 28.7° (p < 0.001). In patients with no glenoid wear (E0/A1), correction of inferior inclination was achievable with a 15° full-wedge baseplate in all cases, reducing the reaming depth by 4.4 mm (p < 0.001). In patients with severe glenoid wear, a 35° half wedge baseplate was often necessary to correct the deformity. The most common complications were stress reactions/fractures.

Conclusion

A metal wedged baseplate can achieve neutral inclination in all patients, minimising bone reaming and preserving lateralisation with good two-year outcomes.

Level of evidence

IV (case series with no comparison group).

Outcomes following revision of a failed primary reverse shoulder arthroplasty

Aims

Reverse shoulder arthroplasty (RSA) has become the most common type of shoulder arthroplasty used in the UK, and a better understanding of the outcomes after revision of a failed RSA is needed. The aim of this study was to review the current evidence systematically to determine patient-reported outcome measures and the rates of re-revision and complications for patients undergoing revision of a RSA.

Methods

MEDLINE, Embase, CENTRAL, and the Cochrane Database of Systematic Reviews were searched. Studies involving adult patients who underwent revision of a primary RSA for any indication were included. Those who underwent a RSA for failure of a total shoulder arthroplasty or hemiarthroplasty were excluded. Pre- and postoperative shoulder scores were evaluated in a random effects meta-analysis to determine the mean difference. The rates of re-revision and complications were also calculated.

Results

The initial search elicited 3,166 results and, following removal of duplicates and screening, 13 studies with a total of 1,042 RSAs were identified. An increase in shoulder scores pre- to postoperatively was reported in all the studies. Following revision of a RSA to a further RSA, there was a significant increase in the American Shoulder and Elbow Surgeons Score (mean difference 20.78 (95% CI 8.16 to 33.40); p = 0.001). A re-revision rate at final follow-up ranging from 9% to 32%, a one-year re-revision rate of 14%, and a five-year re-revision rate of 23% were reported. The complication rate in all the studies was between 18.5% and 36%, with a total incidence of 29%.

Conclusion

This is the largest systematic review of the outcomes following revision of a RSA. We found an improvement in functional outcomes after revision surgery, but the rates of re-revision and complications are high and warrant consideration when planning a revision procedure.

Increased Deltoid and Acromial Stress with Glenoid Lateralization and Onlay Humeral Stem Constructs in Reverse Shoulder Arthroplasty

Background

Reverse shoulder arthroplasty (RSA) designs include multiple options for glenoid component lateralization, and humeral component lateralization and distalization (inlay/onlay constructs). The influence of combined glenoid lateralization, and humeral distalization on acromial and deltoid stresses is not well understood. The purpose of this study was to evaluate changes in deltoid and acromial stresses with variations in glenoid lateralization, and with inlay versus onlay humeral components in RSA.

Methods

Finite element analysis was performed using a RSA system with both inlay and onlay configurations. Variations in total glenoid lateralization from 3 to 9 mm were evaluated. Deltoid and acromial stresses were determined following virtual implantation and with 50° of external rotation.

Results

Increased glenoid lateralization resulted in greater stress of the deltoid and acromion. There was a modest increase in deltoid stress with glenoid lateralization alone (7% and 7.5% with progressive lateralization from 3 to 6 mm and 6 to 9 mm, respectively), but deltoid stress increased substantially with use of an onlay construct (60% at 9 mm of glenoid lateralization). Acromial stress correspondingly increased 37% with glenoid lateralization, and up to 117% with an onlay humeral construct.

Discussion

Increased lateralization of the glenoid component resulted in increased levels of deltoid and acromial stress. For a given amount of glenoid lateralization, utilization of an inlay stem decreased acromial and deltoid stresses compared to onlay constructs. These data allow surgeons to better understand the interactions of glenoid and humeral lateralization and distalization in the setting of contemporary RSA systems.Level of Evidence: Basic Science Study: Computer Modeling.

Large variability in degree of constraint of reverse total shoulder arthroplasty liners between different implant systems

Aims

The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems.

Methods

An implant company's independent 3D shoulder arthroplasty planning software (mediCAD 3D shoulder v. 7.0, module v. 2.1.84.173.43) was used to determine the jump height of standard and constrained liners of different sizes (radius of curvature) of all available companies. The obtained parameters were used to calculate the stability ratio (degree of constraint) and angle of coverage (degree of glenosphere coverage by liner) of the different systems. Measurements were independently performed by two raters, and intraclass correlation coefficients were calculated to perform a reliability analysis. Additionally, measurements were compared with parameters provided by the companies themselves, when available, to ensure validity of the software-derived measurements.

Results

There were variations in jump height between rTSA systems at a given size, resulting in large differences in stability ratio between systems. Standard liners exhibited a stability ratio range from 126% to 214% (mean 158% (SD 23%)) and constrained liners a range from 151% to 479% (mean 245% (SD 76%)). The angle of coverage showed a range from 103° to 130° (mean 115° (SD 7°)) for standard and a range from 113° to 156° (mean 133° (SD 11°)) for constrained liners. Four arthroplasty systems kept the stability ratio of standard liners constant (within 5%) across different sizes, while one system showed slight inconsistencies (within 10%), and ten arthroplasty systems showed large inconsistencies (range 11% to 28%). The stability ratio of constrained liners was consistent across different sizes in two arthroplasty systems and inconsistent in seven systems (range 18% to 106%).

Conclusion

Large differences in jump height and resulting degree of constraint of rTSA liners were observed between different implant systems, and in many cases even within the same implant systems. While the immediate clinical effect remains unclear, in theory the degree of constraint of the liner plays an important role for the dislocation and notching risk of a rTSA system.

Intraoperative Navigation in Reverse Shoulder Arthroplasty: Advantages and Future Prospects

Intraoperative navigation is a novel technology that can provide real-time feedback to the surgeon during implantation and enhance the accuracy and precision of glenoid component positioning. Applications of intraoperative navigation systems have demonstrated increased precision in baseplate version and inclination, as well as improved baseplate screw placement, with fewer screws used and greater purchase length achieved when compared to standard instrumentation. Early clinical studies have shown favorable results, with significantly improved patient-reported and clinical outcomes and decreased complications. The implementation of intraoperative navigation is associated with a short learning curve and a minimal increase in operative time. Nevertheless, further research is necessary to substantiate the clinical benefit of navigation and evaluate its economic cost-effectiveness and impact on implant survival. Augmented reality and robotic-assisted surgery are additional emerging technologies that, while novel, hold the potential to further advance the field of shoulder arthroplasty.

Outcomes and complications of revision reverse shoulder arthroplasty after failed primary anatomic shoulder arthroplasty or hemiarthroplasty: a systematic review

BACKGROUND

The purpose of this study is to systematically review the evidence in the literature to ascertain the functional outcomes, range of motion (ROM), and complication and reoperation rates after revision reverse shoulder arthroplasty (RSA) for a failed primary total shoulder arthroplasty (TSA) or hemiarthroplasty (HA).

METHODS

Two independent reviewers performed the literature search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the EMBASE, MEDLINE, and The Cochrane Library databases. Studies were included if they reported clinical outcomes for revision RSA for a failed primary TSA or HA.

RESULTS

Our review found 23 studies including 1041 shoulders (627 TSA and 414 HA) meeting our inclusion criteria. The majority of patients were female (66.1%), with an average age of 69.0 years (range: 39-93 years) and a mean follow-up of 46.3 months. American Shoulder and Elbow Surgeons and visual analog scale pain scores improved from 32.6 to 61.9 and 6.7 to 2.7, respectively. ROM results include forward flexion, abduction, and external rotation, which improved from 59.4° to 107.7°, 50.7° to 104.4°, and 19.8° to 26.3°, respectively. Only 1 of the 10 studies reporting internal rotation found a statistically significant difference, with the mean internal rotation improving from S1-S3 preoperatively to L4-L5 postoperatively for patients undergoing HA. The overall complication rate and reoperation rate were 23.4% and 12.5%, respectively. The most common complications were glenoid component loosening (6.0%), fracture (periprosthetic, intraoperative, or other scapula fractures) (n = 4.7%), and infection (n = 3.3%).

CONCLUSIONS

Revision RSA for a failed primary TSA and HA has been shown to result in excellent functional outcomes and improved ROM, suggesting that patients who have failed TSA or HA may benefit from a revision RSA.

Utility of superior augments in reverse shoulder arthroplasty (Exactech, Equinoxe GPS) without significant glenoid deformity

BACKGROUND

Superior augment use may help avoid superior tilt while minimizing removal of inferior glenoid bone. Therefore, our goal was to compare superior augments vs. no-augment baseplates in reverse shoulder arthroplasty (RSA) for patients with rotator cuff dysfunction and no significant superior glenoid erosion.

METHODS

A multicenter retrospective analysis of 145 patients who underwent RSA with intraoperative navigation (Equinoxe GPS; Exactech) and 3-year follow-up (mean 32 months' follow-up, range 20-61 months) who had preoperative superior inclination less than 10° and retroversion less than 15°. Patient demographics, radiographic measurements, surgical characteristics, patient-reported outcomes at preoperative and postoperative visit closest to 3 years, and adverse events at final follow-up were obtained. Operative time, planned inclination, and planned version of the baseplate were obtained. χ2 test was used to compare categorical variables, and Student t test was used to compare the augment and no-augment cohorts.

RESULTS

The study population consisted of 54 superior augment patients and 91 no-augment patients. The augment cohort had lower body mass index (27.2 vs. 29.4, P = .023) and higher native superior inclination (5.9° vs. 1.4°, P < .001). No difference between the augment and no-augment cohorts was found regarding age (P = .643), gender (P = .314), medical comorbidities (P > .05), surgical indication (P = .082), and native glenoid version (P = .564). The augment cohort had higher internal rotation score (4.6 vs. 3.9, P = .023), and all remaining range of motion (ROM) and patient-reported outcomes (PROs) preoperatively were not significantly different. At final follow-up, active ROM in all planes was not different between the cohorts. Regarding PROs, the postoperative Shoulder Arthroplasty Smart score was significantly higher (78.0 vs. 73.6, P = .042), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score trended toward higher (83.6 vs. 77.5, P = .063) in the augment cohort. The augment cohort had a significantly lower proportion of patients who planned to have superior baseplate tilt (1.9% vs. 14.3%, P = .012) and had greater mean inclination correction (6.3° vs. 1.3°, P < .001), compared with the no-augment cohort. Adverse events were rare, and there was no significant difference found between the augment and no-augment cohorts (5.6% vs. 3.3%, P = .509).

DISCUSSION

Superior augmented baseplate in RSA with minimal superior glenoid erosion is associated with similar ROM and adverse events with somewhat improved postoperative PROs compared with nonaugmented baseplates at the 3-year follow-up. Additionally, superior augments resulted in a greater proportion of baseplates planned to avoid superior tilt, and trended toward shorter operative times. Further investigation of long-term glenoid baseplate loosening is imperative to fully understand the cost-effectiveness of superior augments in the setting of minimal glenoid deformity.

Posteroinferior glenosphere positioning is associated with improved range of motion following reverse shoulder arthroplasty with a 135° inlay humeral component and lateralized glenoid

BACKGROUND

Optimal glenosphere positioning in a lateralized reverse shoulder arthroplasty (RSA) to maximize functional outcomes has yet to be clearly defined. Center of rotation (COR) measurements have largely relied on anteroposterior radiographs, which allow assessment of lateralization and inferior position, but ignore scapular Y radiographs, which may provide an assessment of the posterior and inferior position relative to the acromion. The purpose of this study was to evaluate the COR in the sagittal plane and assess the effect of glenosphere positioning with functional outcomes using a 135° inlay stem with a lateralized glenoid.

METHODS

A retrospective review was performed on a prospectively maintained multicenter database on patients who underwent primary RSA from 2015 to 2021 with a 135° inlay stem. The COR was measured on minimum 2-year postoperative sagittal plain radiographs using a best-fit circle fit method. A best-fit circle was made on the glenosphere and the center was marked. From there, 4 measurements were made: (1) center to the inner cortex of the coracoid, (2) center to the inner cortex of the anterior acromion, (3) center to the inner cortex of the middle acromion, and (4) center to the inner cortex of the posterior acromion. Regression analysis was performed to evaluate any association between the position of the COR relative to bony landmarks with functional outcomes.

RESULTS

A total of 136 RSAs met the study criteria. There was no relation with any of the distances with outcome scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, visual analog scale). In regard to range of motion (ROM), each distance had an effect on at least 1 parameter. The COR to coracoid distance had the broadest association with ROM, with improvements in forward flexion (FF), external rotation (ER0), and internal rotation with the arm at 90° (IR90) (P < .001, P = .031, and P < .001, respectively). The COR to coracoid distance was also the only distance to affect the final FF and IR90. For every 1-mm increase in this distance, there was a 1.8° increase in FF and 1.5° increase in IR90 (β = 1.78, 95% confidence interval [CI] 0.85-2.72, P < .001, and β = 1.53, 95% CI 0.65-2.41, P < .001; respectively).

CONCLUSION

Evaluation of the COR following RSA in the sagittal plane suggests that a posteroinferior glenosphere position may improve ROM when using a 135° inlay humeral component and a lateralized glenoid.

Demographic-, Radiographic-, and Surgery-Related Factors Do Not Affect Functional Internal Rotation Following Reverse Total Shoulder Arthroplasty: A Retrospective Comparative Study

PURPOSE

This study aimed to identify the demographic-, radiographic-, and surgery-related factors influencing postoperative functional internal rotation (fIR) following reverse total shoulder arthroplasty (RTSA).

METHODS

In this retrospective cohort study, patients who underwent RTSA between June 2013 and April 2018 at a single institution were assigned to two groups ("IROgood" or "IRObad"). Patients were classified as having good fIR (≥8 points in the Constant-Murley score (CS) and fIR to the twelfth thoracic vertebra or higher) or poor fIR (≤2 points in the CS and fIR to the twelfth thoracic vertebra or lower) after RTSA with a single implant model. The minimum follow-up period was two years. Standardized shoulder-specific scores (Visual Analogue Scale (VAS), Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons Score (ASES), Constant-Murley score (CS)) were used to assess the pre- and postoperative functional status of patients. Postoperative radiographic evaluation included the distalization shoulder angle (DSA), lateralization shoulder angle (LSA), critical shoulder angle (CSA), acromiohumeral distance (AHD), glenoid inclination (GI), medialization of the center of rotation (COR), lateralization of the humerus, and distalization of the greater tuberosity. Additionally, preoperative evaluation included rotator cuff arthropathy according to Hamada, glenoid version, anterior or posterior humeral head subluxation, and fatty infiltration of the rotator cuff according to Goutallier. Univariate analysis of demographic, surgical, radiographic, and implant-associated parameters was performed to identify factors associated with postoperative fIR. The Shapiro-Wilk test assessed the normal distribution of the data. Intergroup comparisons regarding demographic and surgery-related factors were conducted using the Mann-Whitney-U Test. Radiographic changes were compared using chi-square or Fisher's exact tests. The significance level was set at p < 0.05.

RESULTS

Of a total of 42 patients, 17 (age: 73.7 ± 5.0 years, follow-up (FU) 38 months [IQR 29.5-57.5]) were included in the "IRObad" group, and 25 (age: 72 ± 6.1 years, FU 47 months [IQR 30.5-65.5]) were included in the "IROgood" group. All patients were treated with the same type of implant (glenosphere size: 36 mm, 14.3%; 39 mm, 38.1%; 42 mm, 47.6%; neck-shaft angle: 135° in 68.0%; 155° in 32.0%) and had comparable indications. Univariate analysis did not reveal any of the investigated demographic, radiographic, or surgery-related parameters as risk factors for poor postoperative fIR (p > 0.05).

CONCLUSION

None of the investigated factors, including implant-associated parameters, influenced postoperative fIR after RTSA in this cohort.

Optimizing Muscle-Tendon Lengths in Reverse Total Shoulder Arthroplasty: Evaluation of Surgical and Implant-Design-Related Parameters

BACKGROUND

Optimizing the function of muscles that cross the glenohumeral articulation in reverse total shoulder arthroplasty (RTSA) is controversial. The current study used a geometric model of the shoulder to systematically examine surgical placement and implant-design parameters to determine which RTSA configuration most closely reproduces native muscle-tendon lengths of the deltoid and rotator cuff.

METHODS

A geometric model of the glenohumeral joint was developed and adjusted to represent small, medium, and large shoulders. Muscle-tendon lengths were assessed for the anterior deltoid, middle deltoid, posterior deltoid, and supraspinatus from 0 to 90° of scaption; for the subscapularis from 0° to 60° of internal rotation (IR) and 0° to 60° of scaption; for the infraspinatus from 0° to 60° of external rotation (ER) and 0° to 60° of scaption; and for the teres minor from 0° to 60° of ER at 90° of scaption. RTSA designs were virtually implanted using the following parameters: (1) surgical placement with a centered or inferior glenosphere position and a humeral offset of 0, 5, or 10 mm relative to the anatomic neck plane, (2) implant design involving a glenosphere size of 30, 36, or 42 mm, glenosphere lateralization of 0, 5, or 10 mm, and humeral neck-shaft angle of 135°, 145°, or 155°. Thus, 486 RTSA-shoulder size combinations were analyzed. Linear regression assessed the strength of association between parameters and the change in each muscle-tendon length from the native length.

RESULTS

The configuration that most closely restored anatomic muscle-tendon lengths in a small shoulder was a 30-mm glenosphere with a centered position, 5 mm of glenoid lateralization, 0 mm of humeral offset, and a 135° neck-shaft angle. For a medium shoulder, the corresponding combination was 36 mm, centered, 5 mm, 0 mm, and 135°. For a large shoulder, it was 30 mm, centered, 10 mm, 0 mm, and 135°. The most important implant-design parameter associated with restoration of native muscle-tendon lengths was the neck-shaft angle, with a 135° neck-shaft angle being favored (β = 0.568 to 0.657, p < 0.001). The most important surgical parameter associated with restoration of native muscle-tendon lengths was humeral offset, with a humeral socket placed at the anatomic neck plane being favored (β = 0.441 to 0.535, p < 0.001).

CONCLUSIONS

A combination of a smaller, lateralized glenosphere, a humeral socket placed at the anatomic neck plane, and an anatomic 135° neck-shaft angle best restored native deltoid and rotator cuff muscle-tendon lengths in RTSA.

CLINICAL RELEVANCE

This study of surgical and implant factors in RTSA highlighted optimal configurations for restoration of native muscle-tendon lengths of the deltoid and rotator cuff, which has direct implications for surgical technique and implant selection. Additionally, it demonstrated the most influential surgical and implant factors with respect to muscle-tendon lengths, which can be used to aid intraoperative decision-making.

The impact of mental health conditions on clinical and functional outcomes after shoulder arthroplasty: a systematic review

Background

Shoulder arthroplasty (SA) has been shown to improve quality of life, though outcomes may vary between individuals. Multiple factors may affect outcomes, including preoperative mental health conditions (MHCs). The goal of this systematic review was to evaluate the clinical and functional outcomes after SA in patients with MHC compared to patients without MHC.

Methods

This systematic review was performed in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines outlined by Cochrane Collaboration. A search of PubMed, the Medline Library, and EMBASE was conducted from inception until September 2023 to obtain studies reporting outcomes after total shoulder arthroplasty and reverse total shoulder arthroplasty in patients with and without MHC. Study characteristics and information on clinical and functional outcomes were collected. All included studies were case-control studies. The methodological quality of the included primary studies was appraised using the methodological index for nonrandomized studies scoring.

Results

Eleven articles published between 2016 and 2023 met inclusion criteria. In total, 49,187 patients, 49,289 shoulders, and five different MHC were included. 8134 patients in the cohort had a diagnosed MHC. The mean patient age was 67.8 years (range, 63.5-71.6 years), and 52.6% of the patients were female. The mean follow-up time was 35.5 months (range, 16.2-58.3 months). Reverse total shoulder arthroplasty was the most common type of procedure (25,543 shoulders, 51.8%). Depression and anxiety were the most reported psychiatric diagnoses (7990 patients, 98.2%). Patients with versus without MHC reported mean improvements of 38 and 42 in American Shoulder and Elbow Surgeons shoulder score and mean Visual Analog Scale pain improvements of 4.7 and 4.9, respectively. Mean complication rates of 31.4% and 14.2% were observed in patients with versus without MHC, respectively. The most prevalent surgical complication in patients with MHC was infection (1.8%), followed by prosthetic complication (1.7%), and adhesive capsulitis (1.6%).

Conclusions

Patients with MHC may have lower preoperative range of motion, worse postoperative shoulder function, and higher postoperative pain levels than patients without MHC. Patients with MHC demonstrated improvements in range of motion and functional outcomes after SA but had higher reported complication and revision rates when compared to patients without MHC. Depression and anxiety were the leading conditions correlated with lower outcomes in patients with MHC after SA. Preoperative physical therapy, mental health counseling, and expectation setting may help these patients reach the maximal achievable benefit from SA.

Tendon Transfers in Reverse Total Shoulder Arthroplasty: A Systematic Review

PURPOSE

The purpose of this study was to evaluate clinical outcomes after tendon transfers in the setting of reverse total shoulder arthroplasty (RTSA).

METHODS

PubMed and Embase were searched according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines to find primary clinical studies of any type of tendon transfer in the setting of RTSA.

RESULTS

Overall, 17 studies (level of evidence [LOE] I: 1, LOE II: 0, LOE III: 3, LOE IV: 13) met inclusion criteria, with 300 shoulders. Most patients were female (56.7%), with an average age of 68.7 years (range 19 to 89) and a mean follow-up of 46.2 months (range 6 to 174). 11 studies reported outcomes after combined latissimus dorsi and teres major transfer (LDTM) while eight studies reported on latissimus dorsi transfer only (LD). Improvements in commonly reported subjective and functional outcome measures were as follows: external rotation +32° (LDTM) and +30° (LD), flexion +65° (LDTM) and +59° (LD), Visual Analog Score -5.4 (LDTM) and -4.5 (LD), subjective shoulder value +43.8% (LDTM) and +46.3% (LD), and overall Constant score +33.8 (LDTM) and +38.7 (LD). The overall complication rate was 11.3%, including tendon transfer ruptures (0.7%), instability (3.0%), infection (2.0%), and nerve injury (0.3%). The all-cause repeat operation rate was 7.3%, most commonly for arthroplasty revision (5.3%). Subgroup analysis revealed that lateralized implants with tendon transfer resulted in markedly greater improvements in Constant score, flexion, ER1, and ER2 while medialized implants with tendon transfer had markedly greater improvements in Visual Analog Score, subjective shoulder value, and abduction.

CONCLUSION

Patients undergoing tendon transfer of either combined LDTM or latissimus dorsi alone in the setting of RTSA have markedly improved subjective and functional outcomes. A moderate incidence of complications (11.3%) was noted in this patient population.

Editorial Commentary: Even With a High Retear Rate, Shoulder Capsular Reconstruction Outcomes are Promising, But Are We Seeing an Increase in Strength?

Superior capsular reconstruction was developed to restore patient biomechanics for patients with massive irreparable rotator cuff tears that preclude shoulder arthroplasty. Recent studies have shown excellent short-term clinical outcomes and improved pain and functional scores but high rates of complications including retear, loss of fixation, or incomplete healing. An alternative option, reverse total shoulder arthroplasty, is a reliable and safe method to ensure good muscle strength and return to play in this patient group.

Rotator Cuff Arthropathy: A Comprehensive Review

Rotator cuff arthropathy is a spectrum of disease states secondary to full-thickness cuff tears classified by rotator cuff insufficiency and degenerative disease within the shoulder joint. Diagnosis can be made through standard physical exam and radiographic films demonstrating varying levels of weakness, along with acetabularization, femoralization, and superior migration of the humeral head. Severity of disease is classified through both the Hamada and Seebauer grading systems, which are used clinically to determine the appropriate treatment algorithm. Treatment exists along the spectrum from conservative therapy with physical therapy to a definitive treatment with total joint replacement. Depending on a patient's progression and other comorbidities, arthroscopic treatments may additionally be used in specific circumstances as joint-sparing techniques. In recent years, reverse total shoulder arthroplasty has produced increasingly favorable outcomes with improvements in pain and function while simultaneously diminishing complication rates, making it generally accepted as standard of care. This disease limits quality of life for a large population of patients and efforts toward optimization of the treatment regimen is critical. This review provides an overview on the diagnostic criteria, classification, pathoanatomic changes, biomechanics, treatment options, outcomes, and complications of rotator cuff arthropathy.

Functional and radiographic outcomes of reverse shoulder arthroplasty with a minimum follow-up of 10 years

BACKGROUND

The use of reverse shoulder arthroplasty (RSA) is becoming increasingly prevalent. However, few studies have been published reporting the long-term outcomes of RSA. This study aims to report the clinical, radiographic, and patient-reported outcomes of the Delta Xtend reverse shoulder prosthesis, performed by a single surgeon and with a minimum follow-up of 10 years.

METHODS

All RSA procedures performed between 2005 and 2012 were identified. Patients were contacted and invited for a follow-up visit including clinical assessment, radiographs, and patient-reported outcome measures. Patients with a follow-up of less than 10 years were excluded. The revision-free implant survival was calculated at 10 years. Between 2005 and 2012, 119 procedures in 116 patients meeting inclusion criteria were identified. Of these patients, 35 were deceased before reaching the 10-year follow-up and 23 could not be reached. In total, 63 RSAs could be included in 61 patients (response rate: 75%). The median follow-up was 11.7 years (interquartile range [IQR]: 10.5-13.2).

RESULTS

Of the 61 patients, 7 patients underwent a revision after a median of 3 years (IQR: 0.2-9.8) during the total follow-up period. The 10-year implant survival was 94% (95% confidence interval: 84-98). At final follow-up, the median anterior elevation was 135° (IQR: 130°-160°), the median abduction was 120° (IQR: 100°-135°), and the median level reached with internal rotation was L5 (IQR: sacrum-L5). The median Auto-Constant score was 68 (IQR: 53-78), the median Subjective Shoulder Value was 80 (IQR: 70-93), and the median pain score was 0.2/10 (IQR: 0-2). In total, radiographs could be obtained in 25 patients (40%). Scapular notching occurred in 10 patients (40%), which was classified as Sirveaux-Nerot grade IV in 3 patients (12%). Ossification occurred in 10 patients (40%), and stress shielding in 2 patients (8%). Radiolucencies were observed around the humeral component in 24 patients (96%) and around the glenoid component in 13 patients (52%).

CONCLUSION

The long-term results of RSA with a Delta Xtend prosthesis are favorable, with long-term improvement in range of motion and patient-reported outcome measures, and a satisfactory implant survival rate. Interestingly, the radiographical analysis showed high prevalence of signs associated with loosening, which did not seem to translate to high complication rates or inferior results.

Both angled bony-increased offset and metal-augmented baseplates provide satisfactory bone incorporation to the glenoid in reverse total shoulder arthroplasty: a radiographic evaluation using tomosynthesis

BACKGROUND

Angled bony-increased offset and metal-augmented baseplate have recently been used to achieve neutral to inferior inclination of the glenoid implant. Nonetheless, bone incorporation is difficult to evaluate using computed tomography or other conventional methods owing to the presence of metal artifacts; therefore, whether bone incorporation between the grafted bone and glenoid or between the graft and baseplate implant can be achieved remains unclear. Several studies have reported the effectiveness of tomosynthesis in reducing metal artifacts for the evaluation of implant loosening, bone resorption, and spot welds. We aimed to evaluate and compare the bone incorporation rates between angled bony-increased offset and metal-augmented implants using tomosynthesis with metal artifact reduction technology. We hypothesized that a high bone incorporation rate would be obtained with angled bony-increased offset and a metal-augmented baseplate.

METHODS

A total of 52 patients who underwent reverse total shoulder arthroplasty (TSA) with angled bony-increased offset and 42 patients who underwent reverse total shoulder arthroplasty with metal-augmented baseplate were assessed and followed up for a minimum of 2 years. The bone incorporation and implant loosening rates were compared between the 2 groups, and the sites of spot welds and trabeculation were recorded according to zones. Bone incorporation between the bone and prosthesis was defined as a confirmation of spot welds connecting the porous area and bone in more than three zones. Bone incorporation between the native bone and grafted bone was defined as an observation of trabeculation. Glenoid loosening was defined as the presence of at least 1 mm radiolucency around the prosthesis in more than 2 zones.

RESULTS

Both the angled bony-increased offset and metal-augmented baseplate groups achieved sufficient bone incorporation rates (98% [51/52 cases] vs. 100% [42/42 cases], P = 1.0) and low implant loosening rates (2% [1/52 cases] vs. 0% [0/42 cases], P = 1.0). Spot welds and trabeculation were likely to be confirmed in the lower parts of the glenoid.

CONCLUSION

The two groups did not show any significant differences regarding bone incorporation rates. Considering the complexity of performing the procedure with angled bony-increased offset, the use of a metal-augmented baseplate can serve as an alternative treatment to avoid superior inclination in reverse total shoulder arthroplasty.

Computer-Assisted Navigation in Reverse Shoulder Arthroplasty: Surgical Experience and Clinical Outcomes

Background: The primary cause of medium- to long-term complications in reverse shoulder arthroplasty (RSA) is the failure of the glenoid component. The purpose of this study was to evaluate both the achievement of planning through computer-assisted navigation and the clinical outcomes at a minimum follow-up (FU) of 12 months. Methods: From December 2019 to December 2022, 57 Equinoxe RSAs with computer-assisted navigation were performed. The average age was 72.8 ± 6.6 years. Using the Orthoblue software, the version and inclination of the glenoid were evaluated from a preoperative CT scan, and planning was performed. Intraoperative navigation data were evaluated, and the clinical outcomes were assessed at a minimum follow-up of 12 months. Results: The average follow-up was 30.7 ± 13.5 months. The planning was reproduced in all implants. No errors in the computer-assisted navigation system were detected. No intraoperative or postoperative complications were recorded. At the final FU, the average active anterior elevation was 143° ± 36°, external rotation was 34° ± 5°, QuickDASH score was 19 ± 16 points, and constant score was 77 ± 18. Conclusions: Computer-assisted navigation is a reliable system for positioning prosthetic implants on challenging glenoids. A longer follow-up period is necessary to confirm the reduction in postoperative complications and the increase in survival compared to traditional RSA.

Complications and Reinterventions of Reverse Total Shoulder Arthroplasty in a Korean Population: 14-Year Experience in Reverse Shoulder Arthroplasty

Background

There are few reports on the revision or reintervention of reverse total shoulder arthroplasty (RTSA) in South Korea. The purpose of this study was to evaluate the true incidence of complications and reintervention of RTSA and clinical and radiological outcomes based on our 14-year experience in RTSA in a Korean population.

Methods

Between March 2008 and June 2022, 412 consecutive cases of RTSA were performed in 388 patients with an average age of 74.4 years at our institute. Excluding 23 patients lost to follow-up, 365 patients (373 shoulders including 8 bilateral cases) who underwent primary RTSA with more than 6 months of follow-up were enrolled in this study. We evaluated those who had complications or reintervention including revision RTSA for failed RTSA. Patient charts were reviewed, and clinical outcomes including clinical scores, complications, and reintervention and radiologic outcomes were evaluated at the last follow-up.

Results

Among the 373 shoulders that underwent primary RTSA, complications were found in 50 patients (13.94%, 10 men and 40 women with a mean age of 75.9 ± 6.7 years [range, 51-87 years]). The causes of complications were as follows: 13 acromion, coracoid, or scapular spine fractures, 10 loosening (glenoid: 5, humeral stem: 5), 5 infections, 4 periprosthetic fractures, 2 instability, 2 neurologic complications, and 14 miscellaneous complications. Twenty patients (5.63%, 4 men and 16 women with a mean age of 74.2 ± 8.2 years [range, 51-87 years]) underwent reintervention. The interval to the first reintervention was 27.8 ± 23.1 months (range, 0.1-78 months). The causes of reintervention (20 cases) were 8 loosening (glenoid: 4, humeral stem: 4), 5 infections, 5 fractures, and 2 instability. Among them, 15 component revisions (4.02%) were performed. At the last follow-up, American Shoulder and Elbow Surgeons, University of California at Los Angeles, and Simple Shoulder Test scores were improved from 25.4, 12.4, and 1.6 preoperatively to 40.4, 16.2, and 3.2, respectively. Forward flexion (48° to 87°), abduction (52° to 79°), external rotation (18° to 22°), and internal rotation (buttock to L2) were improved.

Conclusions

After primary RTSA in a Korean population, the complication, reintervention, and revision rates were 13.94%, 5.63%, and 4.02%, respectively. Careful evaluation of the complications and adequate treatments should be performed.

Rotator cuff tears

Rotator cuff tears are the most common upper extremity condition seen by primary care and orthopaedic surgeons, with a spectrum ranging from tendinopathy to full-thickness tears with arthritic change. Some tears are traumatic, but most rotator cuff problems are degenerative. Not all tears are symptomatic and not all progress, and many patients in whom tears become more extensive do not experience symptom worsening. Hence, a standard algorithm for managing patients is challenging. The pathophysiology of rotator cuff tears is complex and encompasses an interplay between the tendon, bone and muscle. Rotator cuff tears begin as degenerative changes within the tendon, with matrix disorganization and inflammatory changes. Subsequently, tears progress to partial-thickness and then full-thickness tears. Muscle quality, as evidenced by the overall size of the muscle and intramuscular fatty infiltration, also influences symptoms, tear progression and the outcomes of surgery. Treatment depends primarily on symptoms, with non-operative management sufficient for most patients with rotator cuff problems. Modern arthroscopic repair techniques have improved recovery, but outcomes are still limited by a lack of understanding of how to improve tendon to bone healing in many patients.

Midterm outcomes of primary reverse shoulder arthroplasty: a systematic review of studies with minimum 5-year follow-up

Background

Excellent short-term outcomes after reverse shoulder arthroplasty (RSA) have been reported, but longer term outcomes in the existing literature are sparse and vary widely. The purpose of this study is to systematically assess the existing literature to quantify functional outcomes and complication rates after RSA at a minimum of five years of follow-up.

Methods

A Preferred Reporting Items for Systematic Reviews and Meta-analyses-compliant systematic literature search of the PubMed and Embase databases was undertaken. Studies reporting outcomes after primary RSA for nontrauma-related indications with a minimum of 5-year follow-up were included.

Results

Overall, 20 studies satisfied all inclusion criteria. This represented 1591 shoulders in 1556 patients (32.1% males), with a mean age of 70.2 ± 5.0 years and mean follow-up of 8.8 years, or 106.2 ± 30.1 months (60-243). At final follow-up, the mean reported Constant Murley score was 62.1 ± 5.0 (49.0-83.0). The mean adjusted Constant Murley score was 83.5 ± 12.5 (58-111.9). The mean American Shoulder and Elbow Surgeons score was 81.8 ± 4.6, while the mean subjective shoulder value was 74.6 ± 6.4. Overall, 88% of patients rated their satisfaction as either good or very good. The range of active forward flexion, abduction, external, and internal rotation were respectively, 126° ± 13°, 106° ± 11°, 22° ± 11°, and 6° ± 2°. The overall rate of revision surgery was 4.9% (0%-45.5%). Regarding complications, the rate of prosthetic joint infection was 4.3% (0%-26.7%), shoulder dislocation was 3.7% (0%-20.4%), and acromial fracture was 2.0% (0%-8.8%). At final follow-up, 30.9% of shoulders had some degree of scapular notching.

Conclusion

This systematic review shows that RSA results in high satisfaction rates, good clinical outcomes, as well as modest complication and revision rates at minimum 5-year follow-up.

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

BACKGROUND

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). The humeral liner may be changed to a constrained type when stability does not improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type using an RSA computer simulation model.

METHODS

A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included 25 patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Twenty-five cases with a total of 4 patterns of 2 multiplied by 2, making a total of 100 simulations: glenosphere (38 mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were 4 combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner.

RESULTS

Significant differences were found in all impingement-free ROM in 1-way analysis of variance (abduction: P = .01, adduction: P < .01, flexion: P = .01, extension: P = .02, external rotation: P < .01, and internal rotation: P < .01). Tukey's post hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of the normal glenosphere and constrained humeral liner compared with the other combinations, and improved by glenoid lateralization compared with the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, the Pearson χ2 test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of the normal glenosphere and constrained humeral liner group compared with the other groups (P < .01). Bonferroni post hoc tests revealed that the combination of the normal glenosphere and constrained humeral liner was significantly different from that of the lateralized glenosphere and constrained humeral liner (P < .01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM.

CONCLUSION

This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using the lateralized glenosphere improved abduction ROM.

Glenoid lateralization and subscapularis repair are independent predictive factors of improved internal rotation after reverse shoulder arthroplasty

PURPOSE

Reverse shoulder arthroplasty (RSA) has shown improvement in clinical outcomes for various conditions, although some authors expressed concern about the restoration of active internal rotation (AIR). The current study assesses preoperative and intraoperative predictive factors of AIR in patients having a Grammont-style RSA with a minimum five year follow-up.

METHODS

We conducted a retrospective multicentric study, including patients operated on with a 155° Grammont-style RSA for cuff-related pathology or primary osteoarthritis with posterior subluxation or an associated cuff tear. Patients were clinically evaluated at a minimum of five year follow-up. Patients with previous surgery or those who had a tendon transfer with the RSA were excluded. Demographic parameters, BMI, preoperative notes, and operative reports were obtained from medical records. AIR was graded according to the constant score system from 0 to 10.

RESULTS

A total of 280 shoulders in 269 patients (mean age at surgery, 74.9 ± 5.9 years) met the inclusion criteria and were analyzed. The average follow-up was 8.1 years (range, 5-16 years). Overall, AIR increased from 4.2 (SD 2.5, range 0 to 10) preoperatively to 5.9 (SD 2.6, range 0 to 10) at final follow-up. At the last follow-up, AIR increased in 56% of cases, was unchanged in 26% and decreased in 18%. In 188 shoulders (67%), internal rotation was functional and allowed patients to reach the level of L3 or higher. Multivariable linear regression found the following preoperative clinical factors predictive of worse AIR after RSA: male gender (ß = -1.25 [-2.10; -0.40]; p = 0.0042) and higher values of BMI (ß = -0.085 [-0.17; -0.0065]; p = 0.048). Two surgical factors were associated with better AIR after RSA: glenoid lateralization with BIO-RSA technique (ß = 0.80 [0.043; 1.56]; p = 0.039) and subscapularis repair (ß = 1.16 [0.29; 2.02]; p = 0.0092).

CONCLUSIONS

With a mean of eight year follow-up (5 to 16 years), internal rotation was functional (≥ L3 level) in 67% of operated shoulders after Grammont-style RSA; however, two patients out of ten had decreased AIR after surgery. Male patients and those with higher BMIs had worse AIR, with glenoid lateralization (using the BIO-RSA technique) and subscapularis repair, as they are predictive of increased AIR after RSA.

LEVEL OF EVIDENCE

Case series, Level IV.

Outcomes of Guided Personalized Surgery (GPS)-Navigated Reverse Polarity Total Shoulder Joint Replacement in a Low-Volume Hospital

Introduction Reverse polarity shoulder arthroplasty (RSA) is an evolving surgery, and its indications have expanded over time. Apart from cuff tear arthropathy (CTA), it is recommended for complex proximal humerus fractures in the elderly, inflammatory arthritis, primary osteoarthritis in the elderly, and revision for failed hemiarthroplasty. Glenoid base plate placement and fixation are important to prevent complications, especially glenoid base plate loosening, dislocation, and scapular notching, and to improve longevity. Guided personalized surgery (GPS)-navigated RSA was devised to optimize the glenoid base plate position and fixation. Methodology A retrospective study was carried out in a low-volume district general hospital in England. All the patients who underwent GPS-navigated RSA were included. Their preoperative glenoid version, bone stock, glenoid base plate, and glenoid screw lengths were analysed. Preoperative and post-surgery patient-reported outcomes were gathered using the Oxford Shoulder Score (OSS) at six months and annually thereafter. Results Fourteen patients have undergone GPS-navigated RSA in our institute since 2018. Ten patients were female. All of them had a retroverted glenoid with a mean value of 13.6 degrees. Ten out of 14 patients had an augmented glenoid base plate. This included six eight-degree posterior augmentations, three 10-degree superior augmentations, and one extended cage peg. The follow-up period was six months to five years, depending on the date of surgery, and none of the patients dropped out of follow-up. The OSS revealed statistically significant improvement from preoperative values to six months postoperative, an improvement of 21.64±7.175. It also showed progressive improvement over time during postoperative follow-up, and the three-year mean was 47. The commonest complication was fractures, which happened in four cases. There were no infections or dislocations. Discussion Guided personalized surgery-navigated RSA was performed on selected patients at our institution when they were not suitable for conventional RSA due to distorted glenoid anatomy. Glenoid base plate positioning and fixation are important to optimize the outcome of RSA. Guided personalized surgery navigation is helpful in achieving optimum glenoid base placement, especially when the normal glenoid anatomy is distorted. There were no dislocations, glenoid base plate loosening, or scapular notching in the study group. There were four reported fractures, which was comparable with the published literature.

Reverse shoulder arthroplasty: State-of-the-art

The reverse shoulder arthroplasty conceived by Paul Grammont in 1985 has gradually gained popularity as a treatment for multiple shoulder diseases. Unlike previous reverse shoulder prosthesis characterized by unsatisfactory results and a high glenoid implant failure rate, the Grammont design has immediately shown good clinical outcomes. This semi constrained prosthesis solved the issues of the very first designs by medializing and distalizing the center of rotation with an increased stability of the replacement of the component. The indication was initially limited to cuff tear arthropathy (CTA). It has then been expanded to irreparable massive cuff tears and displaced humeral head fractures. The most frequent problems of this design are a limited postoperative external rotation and scapular notching. Different modifications to the original Grammont design have been proposed with the aim of decreasing the risk of failure and complications and improving the clinical outcomes. Both the position and version/inclination of the glenosphere and the humeral configuration (e.g. neck shaft angle) influence the RSA outcomes. A lateralized glenoid (whether with bone or metal) and a 135° Inlay system configuration leads to a moment arm which is the closest to the native shoulder. Clinical research will focus on implant designs reducing bone adaptations and revision rate, strategies to prevent more effectively infections. Furthermore, there is still room for improvement in terms of better postoperative internal and external rotations and clinical outcomes after RSA implanted for humeral fracture and revision shoulder arthroplasty.

Clinical and radiologic outcomes of Lima ProMade custom 3D-printed glenoid components in primary and revision reverse total shoulder arthroplasty with severe glenoid bone loss: a minimum 2-year follow-up

BACKGROUND

The purpose of this study is to report the clinical and radiologic outcomes of patients undergoing primary or revision reverse total shoulder arthroplasty using custom 3D-printed components to manage severe glenoid bone loss with a minimum of 2-year follow-up.

METHODS

Following ethical approval, patients were identified and invited to participate. Inclusion criteria were (1) severe glenoid bone loss necessitating the need for custom implants and (2) patients with definitive glenoid and humeral components implanted more than 2 years prior. Included patients underwent clinical assessment using the Oxford Shoulder Score (OSS), Constant-Murley score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and the quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH). Radiographic assessment included anteroposterior and axial projections. Patients were invited to attend a computed tomography (CT) scan to confirm osseointegration. Statistical analysis used descriptive statistics (mean and standard deviation [SD]) and paired t test for parametric data.

RESULTS

Eleven patients declined to participate. Five patients were deceased prior to study commencement, leaving 42 remaining patients in this analysis. Three patients had revision surgery before the 2-year follow-up; of these, 2 retained their custom glenoid components. Mean follow-up was 31.6 months from surgery (range 24-52 months). All 4 scores improved: OSS from a mean 15 (SD 8.4) to 36 (SD 12) (P < .001), Constant-Murley score from a mean 15 (SD 11.2) to 52 (SD 20.1) (P < .001), QuickDASH from a mean 70 (SD 21) to 31 (SD 24.8) (P = .004), and the ASES score from a mean 22 (SD 17.8) to 71 (SD 23.3) (P = .007). Radiologic evaluation demonstrated good osseointegration in all but 1 included patient.

CONCLUSION

The utility of custom 3D-printed components for managing severe glenoid bone loss in primary and revision reverse total shoulder arthroplasty yields significant clinical improvements in this complex cohort. Large complex glenoid bone defects can be managed successfully with custom 3D-printed glenoid components.

Stemless reverse shoulder arthroplasty: clinical and radiologic outcomes with minimum 2 years' follow-up

BACKGROUND

Recently, a stemless reverse shoulder arthroplasty (RSA) design was developed to preserve bone stock. Clinical and radiologic studies of this design in larger cohorts with >100 patients are not frequent. The purpose of this study was to present the clinical and radiologic results of a newly developed stemless RSA implant. The hypothesis was that this design would provide similar clinical and radiologic results to other stemless implants, as well as stemmed implants.

METHODS

Between September 2015 and December 2019, all patients who underwent primary RSA with a stemless Easytech prosthesis were considered eligible for inclusion in this prospective multicenter study. The minimum follow-up period was 2 years. Clinical outcomes consisted of the Constant score, adjusted Constant score, QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) score, Subjective Shoulder Value, and American Shoulder and Elbow Surgeons shoulder score. Radiographic parameters included radiolucency, loosening, scapular notching, and specific geometric parameters.

RESULTS

Stemless RSA was performed in 115 patients (61 women and 54 men) at 6 different clinical centers. The average age at the time of surgery was 68.7 years. The average Constant score was 32.5 preoperatively and showed significant improvement to 61.8 at latest follow-up (P < .001). The Subjective Shoulder Value also demonstrated significant improvement postoperatively (from 27.0 to 77.5, P < .001). Scapular notching was observed in 28 patients (24.3%); humeral loosening, 5 (4.3%); and glenoid loosening, 4 (3.5%). The total complication rate was 17.4%. Eight patients (4 women and 4 men) underwent implant revision.

CONCLUSION

The clinical outcomes of the examined stemless RSA seem to be comparable to those of other humeral designs; however, the complication and revision rates are higher than those of historical controls. Surgeons should proceed with caution when using this implant until longer-term follow-up data are available.

Optimizing glenoid bone preservation in reverse total shoulder arthroplasty using augmented baseplates

Background

As techniques and implants for reverse total shoulder arthroplasty (rTSA) evolve, a greater emphasis is being placed on preserving glenoid bone stock and optimizing shoulder biomechanics. Augmented baseplates preserve glenoid bone and improve shoulder range of motion by lateralizing the center of rotation of the glenosphere, while also reducing postoperative complications after rTSA. The technique for bone preservation with use of augmented baseplates in the absence of bone loss and the outcomes of a series of cases are contained in this report.

Materials and Methods

A retrospective chart review was conducted for 37 patients with Walch type A1/Sirveaux E0 glenoids who underwent primary rTSA using a bone preserving technique with an augmented baseplate between January 2018 and January 2019 at a single site by a single surgeon. The primary outcome measures were range of motion, strength, and patient-reported clinical outcomes (pain and function rated on a visual analog scale; single assessment numeric evaluation; American Shoulder and Elbow Surgeons score; and disabilities of the arm, shoulder, and hand score). Preoperative radiographs were analyzed for the presence of glenoid bone loss and postoperative radiographs were assessed for evidence of component loosening and scapular notching. A repeated measures design was used, and preoperative and postoperative comparisons were made using parametric t-tests.

Results

At an average follow-up of 23.3 ± 6.3 months, there was a significant improvement in active forward flexion and abduction and nonsignificant improvement in external rotation. There was no radiographic evidence of glenoid notching in any of the patients and optimal glenoid inclination was observed. Patient-reported outcome scores after an average of 25.2 ± 10.0 months indicated a significant improvement in pain, function, and scores for the American Shoulder and Elbow Surgeons and disabilities of the arm, shoulder, and hand assessments. There were no substantial postoperative radiographic findings, intra/postoperative complications, or revisions/reoperations.

Conclusion

rTSA with augmented baseplates for glenoid bone preservation in patients with minimal or no bone loss is effective for preserving glenoid bone stock and significantly improves the range of motion and patient-reported outcomes after approximately 2 years.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.