Analysis of three different reverse shoulder arthroplasty designs for cuff tear arthropathy - the combination of lateralization and distalization provides best mobility.

BACKGROUND: The two major reverse shoulder arthroplasty (RSA) designs are the Grammont design and the lateralized design. Even if the lateralized design is biomechanically favored, the classic Grammont prosthesis continues to be used. Functional and subjective patient scores as well as implant survival described in the literature so far are comparable to the lateralized design. A pure comparison of how the RSA design influences outcome in patients has not yet been determined. The aim of this study was a comparison focused on patients with cuff tear arthropathy (CTA). METHODS: We analyzed registry data from 696 CTA patients prospectively collected between 2012 and 2020 in two specialized orthopedic centers up to 2 years post-RSA with the same follow-up time points (6,12 24 months). Complete teres minor tears were excluded. Three groups were defined: group 1 (inlay, 155° humeral inclination, 36 + 2 mm eccentric glenosphere (n = 50)), group 2 (inlay, 135° humeral inclination, 36 + 4 mm lateralized glenosphere (n = 141)) and group 3 (onlay, 145° humeral inclination, + 3 mm lateralized base plate, 36 + 2 mm eccentric glenosphere (n = 35)) We compared group differences in clinical outcomes (e.g., active and passive range of motion (ROM), abduction strength, Constant-Murley score (CS)), radiographic evaluations of prosthetic position, scapular anatomy and complications using mixed models adjusted for age and sex. RESULTS: The final analysis included 226 patients. The overall adjusted p-value of the CS for all time-points showed no significant difference (p = 0.466). Flexion of group 3 (mean, 155° (SD 13)) was higher than flexion of group 1 (mean, 142° (SD 18) and 2 (mean, 132° (SD 18) (p < 0.001). Values for abduction of group 3 (mean, 145° (SD 23)) were bigger than those of group 1 (mean, 130° (SD 22)) and group 2 (mean, 118° (SD 25)) (p < 0.001). Mean external rotation for group 3 (mean, 41° (SD 23)) and group 2 (mean, 38° (SD 17)) was larger than external rotation of group 1 (mean, 24° (SD 16)) (p < 0.001); a greater proportion of group 2 (78%) and 3 (69%) patients reached L3 level on internal rotation compared to group 1 (44%) (p = 0.003). Prosthesis position measurements were similar, but group 3 had significantly less scapular notching (14%) versus 24% (group 2) and 50% (group 1) (p = 0.001). CONCLUSIONS: Outcome scores of different RSA designs for CTA revealed comparable results. However, CTA patients with a lateralized and distalized RSA configuration were associated with achieving better flexion and abduction with less scapular notching. A better rotation was associated with either of the lateralized RSA designs in comparison with the classic Grammont prosthesis. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Outcome of reverse shoulder arthroplasty secondary to rotator cuff arthropathy in a low-income population.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is a valuable treatment for rotator cuff arthropathy (RCA) in developed regions. Socioeconomic issues impact access to specialized care and there is a lack of data on RSA outcomes in developing regions. We present our 24-month follow-up on RSA surgeries to treat RCA in our low-income population. METHODS: Prospective evaluation of 26 patients subjected to RSA at Hospital Geral de Fortaleza-CE, Brazil, between January 2018 and December 2020. Literacy [>/≤ 8 school years(SY)] and income were documented. Outcomes considered pain (visual analogue scale; VAS) as well as SSV, SPADI, ASES, and UCLA scoring, and range of motion [forward flexion (FF); external rotation (ER)]. RESULTS: Patients were 68.5 ± 7.6 years-old with 16(61.5%) females; 65% had hypertension and 7 (26.9%) had diabetes. Over 90% declared < 900.00 US$ monthly family earnings and 10 (38.4%) patients declared ≤8 SY with > 80% exerting blue-collar jobs. Pain showed a significant reduction from baseline (8 ± 2) to 24 months (2.1 ± 2.3; p < 0.001). UCLA (10.3 ± 5.6 and 28.6 ± 7.2), ASES (16.7 ± 10.8 and 63.1 ± 28.4), SSV (326 ± 311 and 760 ± 234), and SPADI (98.3 ± 26.5) scores significantly improved from baseline to 24 months, achieving minimal clinically important difference. FF (89.2° ± 51.2° to 140.6 ± 38.3°) and ER (19.2° ± 22.5 to 33.4° ± 20.6°) significantly improved from baseline to 24 months (p = 0.004 and 0.027, respectively). There were 5 non-serious adverse events with one surgical revision. All patients returned to daily life activities. CONCLUSION: This is the first outcome report 2 years following RSA in a low-income population. Data indicate this procedure is justifiable regardless of socioeconomic issues.

Predictive factors for postoperative outcomes after reverse shoulder arthroplasty: a systematic review.

BACKGROUND: The use of reverse total shoulder arthroplasty (RTSA) has increased at a greater rate than other shoulder procedures. In general, clinical and functional outcomes after RTSA have been favorable regardless of indication. However, little evidence exists regarding patient specific factors associated with clinical improvement after RTSA. Predicting postoperative outcomes after RTSA may support patients and physicians to establish more accurate patient expectations and contribute in treatment decisions. The aim of this study was to determine predictive factors for postoperative outcomes after RTSA for patients with degenerative shoulder disorders. METHODS: EMBASE, PubMed, Cochrane Library and PEDro were searched to identify cohort studies reporting on predictive factors for postoperative outcomes after RTSA. Authors independently screened publications on eligibility. Risk of bias for each publication was assessed using the QUIPS tool. A qualitative description of the results was given. The GRADE framework was used to establish the quality of evidence. RESULTS: A total of 1986 references were found of which 11 relevant articles were included in the analysis. Risk of bias was assessed as low (N = 7, 63.6%) or moderate (N = 4, 36.4%). According to the evidence synthesis there was moderate-quality evidence indicating that greater height predicts better postoperative shoulder function, and greater preoperative range of motion (ROM) predicts increased postoperative ROM following. CONCLUSION: Preoperative predictive factors that may predict postoperative outcomes are: patient height and preoperative range of motion. These factors should be considered in the preoperative decision making for a RTSA, and can potentially be used to aid in preoperative decision making. LEVEL OF EVIDENCE: Level I; Systematic review.

The effect of cuff arthropathy stage on sleep disturbance and kinesiophobia in reverse shoulder arthroplasty patients.

BACKGROUND: The current study aimed to determine the changes in pre-and post-operative Pittsburg sleep quality index (PSQI) and Tampa scale of kinesiophobia (TSK) values ​​according to the Hamada classification in patients who underwent reverse shoulder arthroplasty (RSA) for rotator cuff tear arthropathy (RCTA). METHODS: One hundred and eight patients who underwent RSA for RCTA were reviewed retrospectively. The patients were divided into two groups with low grade (stages 1-2-3) (n = 49) and high grade (stages 4a-4b-5) (n = 59) according to the Hamada classification, which is the radiographic evaluation of RCTA. PSQI and TSK values ​​were calculated preoperatively, and post-operatively at the 6th week, 6th month, and 1st year. The change in PSQI and TSK values ​​between the evaluations and the effect of staging according to the Hamada classification on this change was examined. RESULTS: When compared in preoperative evaluations, PSQI and TSK scores were found to be lower in low-grade group 1 (7.39 ± 1.56, 51.88 ± 4.62, respectively) than in high-grade group 2 (10.47 ± 2.39, 57.05 ± 3.25, respectively) according to Hamada classification (both p < 0.001). In the postoperative evaluations, PSQI and TSK results decreased gradually compared to the preoperative evaluations, and there was a severe decrease in both parameters between the 6th-week and 6th-month evaluations (both p < 0.001). Preoperatively, 102 (95%) patients had sleep disturbance (PSQI ≥ 6), and 108 (100%) patients had high kinesiophobia (TSK > 37). In the 1st year follow-ups, sleep disturbance was observed in 5 (5%) patients and kinesiophobia in 1 (1%) patient. When the Hamada stages were compared, it was seen that there was a significant difference before the operation (both p < 0.001), but the statistically significant difference disappeared in the PSQI value in the 1st year (p = 0.092) and in the TSK value in the 6th month (p = 0.164) post-operatively. It was observed that Hamada staging caused significant differences in PSQI and TSK values ​​in the preoperative period but did not affect the clinical results after treatment. CONCLUSIONS: RSA performed based on RCTA improves sleep quality and reduces kinesiophobia. RCTA stage negatively affects PSQI and TSK before the operation but does not show any effect after the treatment.

Revision of failed reverse total shoulder arthroplasty with reverse: short-term clinical outcomes.

BACKGROUND: The prevalence of failed reverse total shoulder arthroplasty (rTSA) is increasing. This can often present a challenging clinical situation with substantial bone loss and limited reconstruction options. This study reports a single tertiary referral center's experience with revision of failed rTSA managed with revision rTSA of bone-interfacing components. METHODS: After institutional review board approval, all revision shoulder arthroplasty cases performed at a single institution between 2012 and 2020 were reviewed. Cases in which rTSA was revised to a new rTSA construct with revision of at least 1 bone-interfacing implant (humeral stem and/or baseplate) with a minimum 2-year follow-up were identified. Characteristics of revision cases-including indications, bony stock, revised components, and use of bone graft-were collected. All patients were contacted for patient-reported outcome measures at a minimum of 2 years after surgery. In addition, the incidence and indication for any reoperation after revision were determined. RESULTS: Thirty-three patients with an average age of 66 years (range: 46-82 years), with 19 (58%) being female, met the inclusion criteria and had a mean follow-up of 4.2 years (range: 2-8 years). The most common indication for revision rTSA included humeral component loosening (33%; 11/33), baseplate loosening (27%; 9/33), and instability (21%; 7/33). Prerevision infectious workup demonstrated no cases of periprosthetic shoulder infection. Thirteen cases had massive bone loss-5 treated with humeral allograft prosthetic composite, 5 with glenoid bone grafting, and 3 with custom glenoid implant. In total, 10 of 33 cases (30%) required reoperation at a mean of 13 months (range: 1-44 months) for instability (4), humeral loosening (2), infection (1), baseplate loosening (1), or periprosthetic fracture (1). The reoperation rate for patients with revised baseplates only, humerus only, or combined was 23% (3/13), 28% (5/18), and 27% (3/11), respectively. Overall, the visual analog scale pain score improved from 6.5 preoperatively to 2.0 (P < .001), and the American Shoulder and Elbow Surgeons score improved from 30.7 to 67.5 (P < .001). However, the postoperative Single Assessment Numeric Evaluation score averaged only 51.2% (range: 2-100%). CONCLUSION: This study demonstrates that failed rTSA can be salvaged with a revision rTSA. However, patient expectations for functional improvements should be tempered, and a high reoperation rate should be expected.

Reverse shoulder arthroplasty for primary glenohumeral osteoarthritis: significantly different characteristics and outcomes in shoulders with intact vs. torn rotator cuff.

PURPOSE: To compare outcomes of reverse shoulder arthroplasty (RSA) for primary osteoarthritis (OA) with and without rotator cuff (RC) tears to those with secondary OA due to RC tears. METHODS: We reviewed records of all patients who received RSA for primary OA or secondary OA. All patients had preoperative radiographs, computed tomographic arthrography (CTA), and/or magnetic resonance imaging (MRI) scans of their shoulders to assess their etiology, glenoid morphology, and fatty infiltration. Pre- and postoperative (at minimum follow-up of 2 years) Constant scores and range of motion were compared between patients who had RSA for primary OA with and without RC tears to those with secondary OA due to RC tears. RESULTS: Of the initial cohort of 605 shoulders (583 patients), 153 were lost to follow-up (25.3%), 25 required revision with implant removal (4.1%), and 13 died of causes unrelated to the surgery (2.1%), and left a final cohort of 414 patients. Of the final cohort, 97 had primary OA with intact RC, 62 had primary OA with RC tears, and 255 had secondary OA. Postoperative Constant scores were significantly higher for primary OA with intact RC (73.8 ± 14.3), compared with both primary OA with RC tears (66.1 ± 14.6, P < .001) and secondary OA (64.1 ± 14.8, P < .001). There were no differences in pre- or postoperative scores between primary OA with RC tears and secondary OA. CONCLUSION: At 2 or more years following RSA, Constant scores were significantly higher for primary OA with intact RC, compared to either primary OA with RC tears or secondary OA, whereas there were no differences in pre- or postoperative scores of shoulders that had primary OA with RC tears vs. secondary OA. The authors recommend distinguishing primary OA with intact RC from primary OA with RC tears, as the two have considerably different characteristics and prognosis following RSA.

Revision reverse shoulder arthroplasty for the management of baseplate failure: an analysis of 676 revision reverse shoulder arthroplasty procedures.

BACKGROUND: Baseplate failure in reverse shoulder arthroplasty (RSA) is a rare but potentially catastrophic complication owing to poor patient outcomes and significant glenoid bone loss. The purpose of this study was to report on the prevalence, causes, and outcomes of revision RSA (rRSA) for baseplate failure or loosening. METHODS: A retrospective review of our institutional database was performed to identify all patients treated for a failed RSA from 2006 to 2021 who required revision to another RSA (rRSA) performed by a single surgeon. A total of 676 failed RSA procedures were identified, and further analysis identified 46 patients (6.8%) who underwent rRSA for baseplate failure with a confirmed loose baseplate at the time of rRSA. The primary outcome was repeated failure of the reimplanted baseplate following rRSA. The mode of failure associated with baseplate failure was stratified into 1 of 3 groups: aseptic, septic, or traumatic. Twenty-four patients underwent primary revision, and 22 had undergone >1 previous arthroplasty prior to undergoing re-revision. Five patients underwent previous rRSA for baseplate failure performed by an outside surgeon. The criteria for secondary outcome analysis of final American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and range of motion were met by 32 patients and 23 patients at 1- and 2-year follow-up, respectively. RESULTS: Three patients (6.5%) had repeated baseplate failure requiring re-revision; 2 had baseplate failure at <1 year with associated periprosthetic infections and underwent conversion to hemiarthroplasty. The third patient experienced traumatic failure at 10 years and underwent successful rRSA. The mean American Shoulder and Elbow Surgeons scores at 1 and 2 years were 62.3 and 61.7, respectively. There was no significant difference in outcomes based on mode of baseplate failure (P = .232) or total arthroplasty burden (P = .305) at 1 year. There were 13 total complications in 11 patients, 5 of which required reoperation for reasons other than baseplate failure. CONCLUSION: In this study, rRSA for baseplate failure constituted 6.8% of all revisions performed over a period of 15 years. Re-revision for recurrent baseplate failure was required in 3 of 46 patients (6.5%). Complications and reoperation rates were higher than those for primary RSA but outcomes were comparable for revision of failed anatomic shoulder arthroplasty.

Total shoulder arthroplasty in patients aged 80 years and older: a systematic review.

BACKGROUND: Elderly patients and their surgeons may eschew shoulder arthroplasty due to concerns over patient safety and longevity. The purpose of this study was to review the current literature evaluating the clinical and radiographic outcomes of shoulder arthroplasty performed in patients 80 years and older. METHODS: A literature search of the Embase, PubMed, Medline, and Cochrane databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies evaluating the outcomes of primary and revision anatomic (aTSA) and reverse (RSA) total shoulder arthroplasty in patients 80 years and older were included for analysis. RESULTS: A total of 15 studies evaluating 1685 primary aTSAs, 1170 primary RSAs, 69 RSAs performed for fracture, and 45 revision RSAs were included for review. The postoperative active forward flexion and external rotation ranged from 138° to 150° and 45° to 48° after aTSA and from 83° to 139° and 16° to 47° after RSA, respectively. Postoperative visual analog scale pain scores ranged from 0 to 1.8 after aTSA and from 0 to 1.4 after RSA. Ninety-day mortality ranged from 0% to 3%, and perioperative complications ranged from 0% to 32%. Late complications ranged from 5.6% to 24% for aTSA patients and 3.5% to 29% for patients undergoing RSA for all indications. Common complications included glenoid loosening (0%-18%) and rotator cuff tear (5.6%-10%) after aTSA and scapular notching (0%-40%) and scapular fracture (4%-9.4%) after RSA. Reoperation rates ranged from 0% to 6% after aTSA and from 0% to 13% after RSA. CONCLUSIONS: aTSA and RSA in this population are safe and effective, demonstrating low rates of perioperative mortality and reoperation, durability that exceeds patient longevity, satisfactory postoperative range of motion, and excellent pain relief. Late complication rates appear to be similar for aTSA and RSA.

Quantifying success after first revision reverse total shoulder arthroplasty: the minimal and substantial clinically important percentage of maximal possible improvement.

BACKGROUND: When patients require reoperation after primary shoulder arthroplasty, revision reverse total shoulder arthroplasty (rTSA) is most commonly performed. However, defining clinically important improvement in these patients is challenging because benchmarks have not been previously defined. Furthermore, although the minimal clinically important difference and substantial clinical benefit are commonly used to assess clinically relevant success, these metrics are limited by ceiling effects that may cause inaccurate estimates of patient success. Our purpose was to define the minimal and substantial clinically important percentage of maximal possible improvement (MCI-%MPI and SCI-%MPI) for commonly used pain and functional outcome scores after revision rTSA and to quantify the proportion of patients achieving clinically relevant success. METHODS: This retrospective cohort study used a prospectively collected single-institution database of patients who underwent first revision rTSA between August 2015 and December 2019. Patients with a diagnosis of periprosthetic fracture or infection were excluded. Outcome scores included the American Shoulder and Elbow Surgeons (ASES), raw and normalized Constant, Shoulder Pain and Disability Index (SPADI), Simple Shoulder Test (SST), and University of California, Los Angeles (UCLA) scores. We used an anchor-based method to calculate the MCI-%MPI and SCI-%MPI. In addition, we calculated the MCI-%MPI using a distribution-based method for historical comparison. The proportions of patients achieving each threshold were assessed. The influence of sex, type of primary shoulder arthroplasty, and reason for revision rTSA were also assessed by calculating cohort-specific thresholds. RESULTS: Ninety-three revision rTSAs with minimum 2-year follow-up were evaluated. The mean age of the patients was 67 years; 56% were female, and the average follow-up was 54 months. Revision rTSA was performed most commonly for failed anatomic TSA (n = 47), followed by hemiarthroplasty (n = 21), rTSA (n = 15), and humeral head resurfacing (n = 10). The indication for revision rTSA was most commonly glenoid loosening (n = 24), followed by rotator cuff failure (n = 23) and subluxation and unexplained pain (n = 11 for both). The anchor-based MCI-%MPI thresholds (% of patients achieving) were ASES = 33% (49%), raw Constant = 23% (64%), normalized Constant = 30% (61%), UCLA = 51% (53%), SST = 26% (68%), and SPADI = 29% (58%). The anchor-based SCI-%MPI thresholds (% of patients achieving) were ASES = 55% (31%), raw Constant = 41% (27%), normalized Constant = 52% (22%), UCLA = 66% (37%), SST = 74% (25%), and SPADI = 49% (34%). CONCLUSIONS: This study is the first to establish thresholds for the MCI-%MPI and SCI-%MPI at minimum 2 years after revision rTSA, providing physicians an evidence-based method to assess patient outcomes postoperatively.

Can we separately measure glenoid vs. humeral lateralization and distalization in reverse shoulder arthroplasty?

BACKGROUND: Lateralization and distalization in reverse shoulder arthroplasty (RSA) can be measured on anteroposterior (AP) radiographs using 2 previously described angles: lateralization shoulder angle (LSA) and distalization shoulder angle (DSA). However, these 2 angles measure global lateralization and distalization but do not allow to differentiate how much lateralization or distalization are attributable to the glenoid and the humerus. We hypothesized that new angles could allow us to separately measure glenoid vs. humeral lateralization and distalization. A more precise understanding of independent glenoid and humeral contributions to lateralization and distalization may be beneficial in subsequent clinical research. METHOD: Retrospective analysis of postoperative AP radiographs of 100 patients who underwent primary RSA for cuff-tear arthropathy, massive cuff tear, or glenohumeral osteoarthritis were analyzed. The new angles that we proposed use well-known bony landmarks (the acromion, glenoid, and humerus) and the most lateral point of the glenosphere, which we termed the "glenoid pivot point" (GPP). For lateralization, we used the GPP to split LSA into 2 new angles: glenoid lateralization angle (GLA) and humeral lateralization angle (HLA). For distalization, we introduced the modified distalization shoulder angle (mDSA) that can also be split into 2 new angles: glenoid distalization angle (GDA) and humeral distalization angle (HDA). Three orthopedic surgeons measured the new angles, using the online tool Tyche. Mean values with overall and individual standard deviations as well as intraclass correlation coefficients (ICCs) were calculated. RESULTS: Because the angles form a triangle, the following equations can be made: LSA = GLA + HLA, and mDSA = GDA + HDA. All angles showed excellent inter- and intraobserver reliability (ICC = 0.92-0.97) with low means of individual standard deviations that indicate a precision of 2° for each angle. CONCLUSION: Use of the most lateral part of the glenosphere (termed glenoid pivot point) allows us to separately measure glenoid vs. humeral lateralization and distalization. The 4 new angles (HLA, GLA, GDA, HDA) described in the present study can be used on true AP radiographs, routinely obtained after shoulder replacement, and the measured angles may be used with all types of reverse prostheses available.

Utility of Superior Augments in Reverse Shoulder Arthroplasty (Exactech, Equinoxe GPS) without Significant Glenoid Deformity.

INTRODUCTION: Superior augment use may help avoid superior tilt while minimizing removal of inferior glenoid bone. Therefore, our goal is to compare superior augments versus no augment baseplates in 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 (Exactech, Equinoxe GPS) and three-year follow-up (mean 32-month follow-up, range 20 to 61 months) who had preoperative superior inclination less than 10 degrees and retroversion less than 15 degrees. Patient demographics, radiographic measurements, surgical characteristics, patient-reported outcomes at preoperative and postoperative visit closest to three years, and adverse events at final follow-up were obtained. Operative time, planned inclination, and planned version of the baseplate were obtained. Chi-square test used to compare categorical variables and student t-test used to compare 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 BMI (27.2 vs. 29.4, p-0.023), higher native superior inclination (5.9 vs. 1.4 degrees, p<0.001). No difference between the augment and no augment cohorts was found regarding age (p=0.643), gender (p=0.314), medical comorbidities (p>0.05), surgical indication (p=0.082), and native glenoid version (p=0.564). The augment cohort had higher internal rotation score (4.6 vs. 3.9, p=0.023), all remaining ROM and 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 SAS score was significantly higher (78.0 vs. 73.6, p=0.042), and ASES score trended towards higher (83.6 vs. 77.5, p=0.063) in the augment cohort. The augment cohort had significantly lower proportion of patients planned to have superior baseplate tilt (1.9% vs. 14.3%, p=0.012), and had greater mean inclination correction (6.3 vs. 1.3 degrees, p<0.001), compared to 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=0.509). 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 to non-augmented baseplates at 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.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND: Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts. METHODS: A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup. RESULTS: The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023). DISCUSSION: Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Reverse total shoulder arthroplasty for acute proximal humeral fracture has comparable 10-year outcomes to elective indications: results from the New Zealand Joint Registry.

HYPOTHESIS AND BACKGROUND: Recently, the indication of reverse total shoulder arthroplasty (RTSA) has expanded beyond rotator cuff arthropathy to include treatment of complex acute proximal humeral fracture (PHF). Limited previous studies have compared the long-term clinical and functional outcomes of patients undergoing RTSA for PHF vs. elective indications for degenerative conditions. The purpose of this study was to compare implant survivorship, reasons for revision and functional outcomes in patients undergoing RTSA for acute PHF with those undergoing elective RTSA in a population-based cohort study. METHODS: Prospectively collected data from the New Zealand Joint Registry from 1999 to 2021 and identified 6862 patients who underwent RTSA. Patients were categorized by preoperative indication, including PHF (10.8%), rotator cuff arthropathy (RCA) (44.5%), osteoarthritis (OA) (34.1%), rheumatoid arthritis (RA) (5.5%), and old traumatic sequelae (5.1%). Revision-free implant survival and functional outcomes (Oxford Shoulder Scores [OSSs] at the 6-month, 5-year, and 10-year follow-ups) were adjusted by age, sex, American Society of Anesthesiologists class, and surgeon experience and compared. RESULTS: Revision-free implant survival at 10 years for RTSA for PHF was 97.3%, compared with 96.1%, 93.7%, 92.8%, and 91.3% for OA, RCA, RA and traumatic sequelae, respectively. When compared with RTSA for PHF, the adjusted risk of revision was significantly higher for traumatic sequelae (hazard ratio = 2.3, P = .023) but not for other elective indications. The most common reason for revision in the PHF group was dislocation or instability (42.9%), which was similar to the OA (47.6%) and traumatic sequelae (33.3%) groups. At 6 months post-surgery, OSSs were significantly lower for the PHF group compared with the RCA, OA, and RA groups (31.1 vs. 35.6, 37.7, and 36.5, respectively, P < .001), and similar to traumatic sequelae (31.7, P = .431). At 5 years, OSSs were only significantly lower for PHF compared with OA (37.4 vs. 41.0, P < .001) and there was no difference between the PHF and other groups. At 10 years, there were no significant differences between groups. CONCLUSIONS: RTSA for PHF demonstrated reliable long-term survivorship and functional outcomes compared with elective indications. Despite lower functional outcomes in the early postoperative period for the PHF group, implant survivorship was similar in patients undergoing RTSA for the primary indication of acute PHF compared with RCA, OA, and RA and superior compared to the primary indication of traumatic sequelae.

Comparison of 3D Computer Assisted Planning With and Without Patient Specific Instrumentation for Severe Bone Defects in Reverse Total Shoulder Arthroplasty.

BACKGROUND: Preoperative planning is an integral aspect of managing complex deformity in reverse shoulder arthroplasty (RSA). The purpose of this study was to compare the success of patient specific instrumentation (PSI) and 3D computer-assisted planning with standard instrumentation (Non-PSI) in achieving planned corrections of the glenoid among patients undergoing RSA with severe bony deformity requiring glenoid bone grafts. METHODS: A retrospective case-control study was performed, including all patients that underwent RSA with combined bone grafting procedures (BIO-RSA or structural bone grafting) for severe glenoid deformity by a single between June 2016 and July 2023. Patients were required to have preoperative and postoperative CT scans as well as preoperative 3D planning performed for inclusion. Patients were divided into two groups based on the use of 3D computer-assisted planning with or without PSI (PSI vs. Non-PSI). The corrected inclination and version were measured by two separate reviewers on preoperative and postoperative 2D CT scans and compared to their corresponding preoperative planning goals utilizing bivariate analyses. RESULTS: We identified 45 patients that met our inclusion criteria (22 PSI and 23 Non-PSI). Preoperative inclination (mean ± SD) (PSI 10.12° ± 15.86°, Non-PSI 9.43° ± 10.64°; P = 0.864) and version (PSI -18.78° ± 18.3°, Non-PSI -17.82° ± 11.49°; P = 0.835) measurements were similar between groups. No significant differences in the mean deviation (error) between the postoperative and planned inclination (PSI 5.49° ± 3.72; Non-PSI 6.91° ± 5.05; P = 0.437) and version (PSI 8.37° ± 5.7; Non-PSI 5.37° ± 4.43; P = 0.054) were found between groups. No difference in the rate of outliers (>10° error) was noted in inclination (P = 0.135) or version (P = 0.445) between groups. Greater planned version correction was correlated with greater error when PSI was utilized (PSI r = 0.519, P = 0.013; Non-PSI r = 0.362, P = 0.089). CONCLUSION: Both PSI and 3D computer-assisted planning without PSI (Non-PSI) appear to be useful techniques to achieve version and inclination correction among patients undergoing RSA with severe glenoid deformity required glenoid bone grafting with no clear superiority of one method over the other. Surgeons should be aware that when utilizing PSI, slightly greater error in achieving version goals may occur as version correction is increased.

Inverted-Bearing Reverse Shoulder Arthroplasty: Long-term Survivorship, Complications, Clinical and Radiological Outcomes.

BACKGROUND: Inverted-bearing reverse shoulder arthroplasty (IB-RSA) is characterized by a polyethylene glenosphere and a metallic humeral liner to minimize PE wear and debris secondary to impingement between the humerus and glenoid neck. IB-RSA long-term survivorship, complication and revision rates, as well as clinical and radiographic outcomes have not been reported yet. METHODS: This is a monocentric retrospective study on a consecutive series of 151 patients who underwent primary IB-RSA from January 2009 to September 2015 and were evaluated clinically and radiologically at minimum 8 years follow-up. All complications and reoperations were recorded. Survivorship analysis with any revision surgery as endpoint was done using Kaplan-Meier survival curves. RESULTS: Seventy-eight patients (follow-up rate 51.7%) were reviewed at a mean follow-up of 10.1 ± 1.9 years. At 10 years the revision-free survival was 98.7% (95% CI: 94.8-99.7). Sixteen complications (10.6%) were observed: 2 axillary nerve injuries, 2 infections, 2 glenoid loosenings (which stabilized within one year), 2 cases of otherwise unexplained painful stiffness, 4 acromial fractures, 1 post-traumatic scapular pillar fracture and 3 post-traumatic humeral periprosthetic fractures. Two patients were revised due to infection. No cases of late glenoid loosening and humeral loosening were observed. The revision rate was 1.3%. All the clinical scores and range of motion significantly improved at the last follow-up compared with preoperative status: final Constant score was 66.1 ± 17.4, SSV 79.1 ± 20.9, ASES 82.2 ± 17.7. Scapular notching was observed in 51.4% of patients: only 1 case of grade 3 notching was observed in an early glenoid subsidence case. CONCLUSIONS: Primary IB-RSA appears to be a safe and effective procedure and does not present specific implant-associated complications at long-term follow-up. Radiographic analysis showed that inverting the biomaterials leads to a distinct kind of notching with mainly mechanical features.

Does the subscapularis refixation affect the clinical outcome after primary reverse shoulder arthroplasty?

BACKGROUND: Reverse shoulder arthroplasty is an established procedure for patients with rotator cuff tear arthropathy. However, the refixation of the subscapularis tendon remains a controversial and frequently discussed topic. This prospective randomized study was conducted to evaluate the clinical benefit of the subscapularis refixation after reverse shoulder arthroplasty. METHODS: Fifty patients (f: 36, m:14) were randomized and assigned to either the "repaired" (rep) or the "not repaired" (nrep) cohort. Intraoperatively, the subscapularis tendon was reattached in the rep-cohort with four tendon-to-tendon sutures, whereas no refixation was performed in the nrep-cohort. The Constant-Murley Score (CS) and the range of motion was evaluated preoperatively as well as 12 and 36 months postoperatively. The Subjective Shoulder Value (SSV) and the Lift-off test were performed 36 months postoperatively. The postoperative subscapularis integrity was assessed sonographically. RESULTS: Twelve months postoperatively the rep-cohort presented better results in the CS (rep: 71 vs. nrep: 66, p: 0.037). The normalized CS was 80% in the rep-cohort and 75% in the nrep-cohort (p: 0.114). At our last follow-up after 36 months we did not find significant differences between the rep-cohort and the nrep-cohort in the CS (rep: 76 vs. nrep: 75, p: 0.285) and normalized CS (rep: 91% vs. nrep: 91%, p: 0.388). Concerning internal rotation (in points) the rep-cohort achieved better results than the nrep-cohort (rep: 7.3 vs. nrep: 6.6, p: 0.040). Flexion (rep: 145° vs. nrep: 151°, p: 0.826), abduction (rep: 135° vs. nrep: 137° p: 0.816), external rotation (rep: 34° vs. nrep: 37°, p: 0.817) and the SSV (rep: 81% vs. nrep: 77%, p: 0.398) presented no significant differences between the cohorts. The ultrasound examination after 36 months displayed an intact tendon in 70%. CONCLUSION: While the subscapularis refixation effects the postoperative internal rotation positively, there were no differences in mid-term follow-up concerning the overall results after rTSA. Further, the external rotation is not affected by the refixation of the subscapularis tendon.

Reverse total shoulder arthroplasty for primary osteoarthritis with restricted preoperative forward elevation demonstrates similar outcomes but faster range of motion recovery compared to anatomic total shoulder arthroplasty.

BACKGROUND: Reverse total shoulder arthroplasty (RSA) has been increasingly utilized for a variety of shoulder pathologies that are difficult to treat with anatomical total shoulder arthroplasty (TSA). Few studies have compared the outcomes of TSA vs. RSA in patients with cuff intact glenohumeral osteoarthritis and poor preoperative forward elevation. This study aimed to determine whether there is a difference in functional outcomes and postoperative range of motion (ROM) between TSA and RSA in these patients. METHODS: This retrospective cohort study included 116 patients who underwent RSA or TSA between 2013 and 2022 for the treatment of rotator cuff intact primary osteoarthritis with restricted preoperative forward flexion (FF) and a minimum 1-year follow-up. Each arthroplasty group was divided into 2 subgroups: patients with preoperative FF between 91° and 120° or FF lower than or equal to 90°. Patients' clinical outcomes, including active ROM, American Shoulder and Elbow Surgeons score, visual analog scale for pain, and subjective shoulder value were collected. Clinical and radiographic complications were evaluated. RESULTS: There was no significant difference between RSA and TSA in terms of sex (58.3% male vs. 62.2% male, P = .692), or follow-up duration (20.1 months vs. 17.7 months, P = .230). However, the RSA cohort was significantly older (72.0 ± 8.2 vs. 65.4 ± 10.6, P = .012) and weaker in FF and (ER) before surgery (P < .001). There was no difference between RSA (57 patients) and TSA (59 patients) in visual analog scale pain score (1.2 ± 2.3 vs. 1.3 ± 2.3, P = .925), subjective shoulder value score (90 ± 15 vs. 90 ± 15, P = .859), or American Shoulder and Elbow Surgeons score (78.4 ± 20.5 vs. 82.1 ± 23.2, P = .476). Postoperative active ROM was statistically similar between RSA and TSA cohorts in FF (145 ± 26 vs. 146 ± 23, P = .728) and ER (39 ± 15 vs. 41 ± 15, P = .584). However, internal rotation was lower in the RSA cohort (P < .001). This was also true in each subgroup. RSA led to faster postoperative FF and ER achievement at 3 months (P < .001). There was no statistically significant difference in complication rates between cohorts. CONCLUSION: This study demonstrates that patients with glenohumeral osteoarthritis who have a structurally intact rotator cuff but limited preoperative forward elevation can achieve predictable clinical improvement in pain, ROM, and function after either TSA or RSA. Reverse arthroplasty may be a reliable treatment option in patients at risk for developing rotator cuff failure.

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 (ß = 1.78, 95% confidence interval [CI] 0.85-2.72, P < .001, and ß = 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.

Navigated augmented reality through a head-mounted display leads to low deviation between planned, intra- and post-operative parameters during glenoid component placement of reverse shoulder arthroplasty: a proof-of-concept case series.

BACKGROUND: Navigated augmented reality (AR) through a head-mounted display (HMD) has led to accurate glenoid component placement in reverse shoulder arthroplasty (RSA) in an in-vitro setting. The purpose of this study is to evaluate the deviation between planned, intra-, and postoperative inclination, retroversion, entry point and depth of the glenoid component placement during RSA, assisted by navigated AR through a HMD, in a surgical setting. METHODS: A prospective, multicenter study was conducted. All consecutive patients undergoing RSA in two institutions, between August 2021 and January 2023, were considered potentially eligible for inclusion in the study. Inclusion criteria were: age >18 years, surgery assisted by AR through a HMD, and postoperative computed tomography (CT) scans at six weeks. All participants agreed to participate in the study and an informed consent was provided in all cases. Preoperative CT scans were undertaken for all cases and used for three-dimensional (3D) planning. Intra-operatively, glenoid preparation and component placement were assisted by a navigated AR system through a HMD in all patients. Intraoperative parameters were recorded by the system. A postoperative CT scan was undertaken at 6 weeks, and 3D reconstruction was used for obtaining postoperative parameters. The deviation between planned, intra-, and postoperative inclination, retroversion, entry point, and depth of the glenoid component placement was calculated. Outliers were defined as >5° for inclination and retroversion and >5 mm for entry point. RESULTS: 17 patients (9 females, 12 right shoulders) with a mean age of 72.8±9.1 years old (range, 47.0 to 82.0) met inclusion criteria. The mean deviation between intra- and postoperative measurements was 1.5°±1.0° (range, 0.0° to 3.0°) for inclination, 2.8°±1.5° (range, 1.0° to 4.5°) for retroversion, 1.8±1.0 mm (range, 0.7mm to 3.0mm) for entry point, and 1.9±1.9 mm (range, 0.0mm to 4.5mm) for depth. The mean deviation between planned and postoperative values was 2.5°±3.2° (range, 0.0° to 11.0°) for inclination, 3.4°±4.6° (range, 0.0° to 18.0°) for retroversion, 2.0±2.5 mm (range, 0.0° to 9.7°) for entry point, and 1.3±1.6 mm (range, 1.3mm to 4.5mm) for depth. There were no outliers between intra- and postoperative values and there were three outliers between planned and postoperative values. The mean time (minutes:seconds) for the tracker unit placement and the scapula registration was 03:02 (range, 01:48 to 04:26) and 08:16 (range, 02:09 to 17:58), respectively. CONCLUSION: The use of a navigated AR system through a HMD in RSA led to low deviations between planned, intra-operative and postoperative parameters for glenoid component placement.

Conjoint tendon lengthening improves internal rotation following reverse total shoulder arthroplasty: a cadaveric study.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is a common procedure for treating a variety of shoulder pathologies. However, many patients struggle with postoperative internal rotation (IR) deficits, which often hinder their activities of daily living. The conjoint tendon provides an anatomic barrier that can impede the postoperative IR of the shoulder, and this study aims to evaluate the effect of a conjoint tendon lengthening on the glenohumeral range of motion (ROM) following RSA. METHODS: This study used ten fresh-frozen cadaver specimens of the upper extremity. An RSA was implanted using a standard deltopectoral approach, and the ROM was assessed postimplantation. Following this, the conjoint tendon was identified and lengthened using a tendon sheath z-plasty, and the ROM was rerecorded. Statistical significance for the ROM gains after conjoint tendon lengthening was determined with a significance level of P < .05. RESULTS: Following the lengthening of the conjoint tendon, there were statistically significant improvements in all ROMs (P < .05). Subjects demonstrated a notable gain in IR to the back by 10.3 cm (P < .01), and all ROMs increased by at least 10°, except for forward flexion, which increased by 6° (P < .001). CONCLUSIONS: This study suggests that lengthening the conjoint tendon improves postoperative ROM of the glenohumeral joint after RSA, offering a potential solution to considerable IR deficits that are commonly encountered post-RSA. Subsequent clinical and biomechanical studies should assess the stability of the shoulder joint following conjoint tendon lengthening.