Severe metallosis following catastrophic failure of total shoulder arthroplasty - a case report.

Metallosis is an unusual but consequential complication arising from orthopedic hardware implantation, characterized by the deposition of metallic particles in the periprosthetic soft tissues. The incidence of metallosis associated with shoulder arthroplasties is exceptionally rare since the shoulder is not a weight-bearing joint, making it less susceptible to mechanical wear and, consequently, to conditions like particle disease and metallosis. Nevertheless, anomalous metal-on-metal interactions can develop in total shoulder arthroplasties if the polyethylene component fails due to wear, fracture, or dissociation. If left unaddressed, metallosis can incite an adverse immune-mediated local tissue response, culminating in joint destruction and adjacent soft tissues and muscle necrosis. In this case report, the diagnosis of metallosis was made in a patient with an anatomic total shoulder arthroplasty using a state-of-the-art photon counting detector CT supplemented by post-processing metal artifact reduction algorithms. This advanced imaging approach was effective in discerning the source of implant failure and in identifying manifestations of severe metallosis including osteolysis and pseudotumor formation. Advanced imaging methods can accurately characterize the severity and extent of metallosis, thereby helping guide surgical planning to mitigate serious complications associated with this condition.

Reverse shoulder arthroplasty design-inlay vs. onlay: does it really make a difference?

BACKGROUND: The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes, and modularity. With respect to the humeral component, the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many. METHODS: It is our hypothesis that separating onlay and inlay designs into 2 distinct entities is an oversimplification as there can be a wide overlap of the 2 designs, depending on surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms-meaning combined distalization and lateralization. RESULTS: By reviewing the many factors that can contribute to the glenosphere-humerus relationship, the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited. Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs. CONCLUSIONS: Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization.

Optimal combination of arthroplasty type, fixation method, and postoperative rehabilitation protocol for complex proximal humerus fractures in the elderly: a network meta-analysis.

BACKGROUND: The purpose of this study was to define the optimal combination of surgical technique and postoperative rehabilitation protocol for elderly patients undergoing either hemiarthroplasty (HA) or reverse total shoulder arthroplasty (rTSA) for acute proximal humerus fracture (PHF) by performing a network meta-analysis of the comparative studies in the literature. METHODS: A systematic review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines of MEDLINE, EMBASE, and Cochrane Library was screened from 2007 to 2023. Inclusion criteria were level I-IV studies utilizing primary HA and/or rTSA published in a peer-reviewed journal, that specified whether humeral stems were cemented or noncemented, specified postoperative rehabilitation protocol, and reported results of HA and/or rTSA performed for PHF. Early range of motion (ROM) was defined as the initiation of active ROM at ≤3 weeks after surgery. Level of evidence was evaluated based on the criteria by the Oxford Centre for Evidence-Based Medicine. Clinical outcomes were compared using a frequentist approach to network meta-analysis with a random-effects model that was performed using the netmeta package version 0.9-6 in R. RESULTS: A total of 28 studies (1119 patients) were included with an average age of 74 ± 3.7 and mean follow-up of 32 ± 11.1 months. In the early ROM cohort (Early), the mean time to active ROM was 2.4 ± 0.76 weeks compared to 5.9 ± 1.04 weeks in the delayed ROM cohort (Delayed). Overall, rTSA-Pressfit-Early resulted in statistically superior outcomes including postoperative forward elevation (126 ± 27.5), abduction (116 ± 30.6), internal rotation (5.27 ± 0.74, corresponding to L3-L1), American Shoulder and Elbow Surgeons score (71.8 ± 17), tuberosity union (89%), and lowest tuberosity nonunion rate (9.6%) in patients ≥65 year old with acute PHF undergoing shoulder arthroplasty (all P ≤ .05). In total there were 277 (14.5%) complications across the cohorts, of which 89/277 (34%) were in the HA-Cement-Delayed cohort. HA-Cement-Delayed resulted in 2-times higher odds of experiencing a complication when compared to rTSA-Cement-Delayed (P = .005). Conversely, rTSA-Cement-Early cohort followed by rTSA-Pressfit-Early resulted in a total complication rate of 4.7% and 5.4% (odds ratios, 0.30; P = .01 & odds ratios, 0.42; P = .05), respectively. The total rate of scapular notching was higher in the cemented rTSA subgroups (16.5%) vs. (8.91%) in the press fit rTSA subgroups (P = .02). CONCLUSION: Our study demonstrates that patients ≥65 years of age, who sustain a 3-or 4-part PHF achieve the most benefit in terms of ROM, postoperative functional outcomes, tuberosity union, and overall complication rate when undergoing rTSA with a noncemented stem and early postoperative ROM when compared to the mainstream preference-rTSA-Cement-Delayed.

Thresholds for diminishing returns in postoperative range of motion after total shoulder arthroplasty.

BACKGROUND: Satisfaction following total shoulder arthroplasty (TSA), which is commonly reported using patient-reported outcome measures (PROMs), is partially dependent upon restoring shoulder range of motion (ROM). We hypothesized there exists a minimum amount of ROM necessary to perform functional tasks queried in PROM questionnaires, beyond which further ROM may provide no further improvement in PROMs. METHODS: A retrospective review of a multicenter international shoulder arthroplasty database was performed between 2004 and 2020 for patients undergoing anatomic or reverse TSA (aTSA, rTSA), with minimum 2-year follow-up. Our primary outcome was to determine the threshold in postoperative active ROM (abduction, forward elevation [FE], external rotation [ER], and internal rotation [IR] score), whereby additional improvement was not associated with additional improvement in PROMs (Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and the Shoulder Pain and Disability Index). For comparison, we also evaluated the Shoulder Arthroplasty Smart (SAS) score, which is not subject to the ceiling effect. RESULTS: We included 4459 TSAs (1802 aTSAs, 2657 rTSAs) with minimum 2-year follow-up (mean, 56 ± 32 months). The threshold in postoperative ROM that were associated with no further improvement were active abduction, 107-113° for PROMs vs. 163° for the SAS score; active FE, 149-162° for PROMs vs. 176° for the SAS score; active ER, 50-52° for PROMs vs. 72° for the SAS score; IR score, 4-5 points for all PROMs vs. 6 points for the SAS score. Out of 3508 TSAs with complete postoperative ROM data, 8.5% achieved or exceeded all ROM thresholds (14.5% aTSAs, 4.8% rTSAs). CONCLUSIONS: Our findings demonstrate that postoperative ROM exceeding 113° of abduction, 162° of FE, 52° of ER, and IR to L1 is associated with minimal additional improvement in PROMs. While individual patient needs vary, the thresholds may provide helpful targets for patients undergoing postoperative rehabilitation.

Prognostic value of the Walch classification for patients before and after shoulder arthroplasty performed for osteoarthritis with an intact rotator cuff.

BACKGROUND: The Walch classification is commonly used by surgeons when determining the treatment of osteoarthritis (OA). However, its utility in prognosticating patient clinical state before and after TSA remains unproven. We assessed the prognostic value of the modified Walch glenoid classification on preoperative clinical state and postoperative clinical and radiographic outcomes in total shoulder arthroplasty (TSA). METHODS: A prospectively collected, multicenter database for a single-platform TSA system was queried for patients with rotator cuff-intact OA and minimum 2 year follow-up after anatomic (aTSA) and reverse TSA (rTSA). Differences in patient-reported outcome scores (Simple Shoulder Test, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Shoulder Pain and Disability Index, visual analog scale for pain, Shoulder Function score), combined patient-reported and clinical-input scores (Constant, University of California-Los Angeles shoulder score, Shoulder Arthroplasty Smart Score), active range of motion values (forward elevation [FE], abduction, external rotation [ER], internal rotation [IR], and radiographic outcomes (humeral and glenoid radiolucency line rates, scapula notching rate) were stratified and compared by glenoid deformity type per the Walch classification for aTSA and rTSA cohorts. Comparisons were performed to assess the ability of the Walch classification to predict the preoperative, postoperative, and improved state after TSA. RESULTS: 1008 TSAs were analyzed including 576 aTSA and 432 rTSA. Comparison of outcomes between Walch glenoid types resulted in 15 pairwise comparisons of 12 clinical outcome metrics, yielding 180 total Walch glenoid pairwise comparisons for each clinical state (preoperative, postoperative, improvement). Of the 180 possible pairwise Walch glenoid type and metric comparisons studied for aTSA and rTSA cohorts, <6% and <2% significantly differed in aTSA and rTSA cohorts, respectively. Significant differences based on Walch type were seen after adjustment for multiple pairwise comparisons in the aTSA cohort for FE and ER preoperatively, the Constant score postoperatively, and for abduction, FE, ER, Constant score, and SAS score for pre- to postoperative improvement. In the rTSA cohort, significant differences were only seen in abduction and Constant score both postoperatively and for pre- to postoperative improvement. There were no statistically significant differences in humeral lucency rate, glenoid lucency rate (aTSA), scapular notching rate (rTSA), complication rates, or revision rates between Walch glenoid types after TSA. CONCLUSION: Although useful for describing degenerative changes to the glenohumeral joint, we demonstrate a weak association between preoperative glenoid morphology according to the Walch classification and clinical state when evaluating patients undergoing TSA for rotator cuff-intact OA. Alternative glenoid classification systems or predictive models should be considered to provide more precise prognoses for patients undergoing TSA for rotator cuff-intact OA.

Outcomes following Humeral Head Autograft Glenoid Reconstruction in Primary Reverse Total Shoulder Arthroplasty.

BACKGROUND: Patients with severe glenoid bone loss are at increased risk for poor implant fixation, scapular notching, dislocation, joint kinematic disturbances, and prosthetic failure following reverse total shoulder arthroplasty (rTSA). Glenoid bone grafting has proven useful when performing rTSA in patients with inadequate glenoid bone stock, although the current literature is limited. The purpose of this study is to evaluate clinical outcomes in patients with significant glenoid deformity undergoing primary rTSA with one-stage glenoid reconstruction using a humeral head autograft. METHODS: A database of prospectively enrolled patients was reviewed to identify patients who underwent primary rTSA with humeral head autograft (n=40) between 2008 and 2020 by six high-volume shoulder arthroplasty surgeons with minimum two-year follow-up. Variables studied included demographics, medical comorbidities, range of motion (ROM), Constant score, American Shoulder and Elbow Surgeons (ASES) score, pain score, patient satisfaction, glenoid deformity, revisions and complications. Preoperative glenoid deformity was characterized using glenoid version and beta-angles, measured on computed tomography (CT). Improvement at final follow-up was compared to a matched control group of 120 standard primary rTSA patients. Following the post hoc Bonferroni correction, an adjusted alpha value of 0.004 was used to define statistical significance. RESULTS: Forty patients were included with a mean follow-up of 5.3 (range, 2.0-13.2) years. Patients exhibited a mean preoperative glenoid retroversion and beta-angle of 29° and 80°, respectively. At final follow-up, patients who received a graft exhibited lower mean scores for active external rotation (25° vs. 39°; p = 0.001) in comparison to those who did not receive a graft. No differences were observed in active abduction (p = 0.029), active forward elevation (p = 0.009), active internal rotation (p = 0.147), passive external rotation (p = 0.082), Global Shoulder Function score (p = 0.157), Constant score (p = 0.036), ASES score (p = 0.009), or pain score (p = 0.186) between groups. Seven patients (17.5%) exhibited complications of which the most common being aseptic glenoid loosening (15%). CONCLUSION: This study demonstrates that patients undergoing primary rTSA with autogenous humeral head autograft for severe glenoid deficiency experience postoperative improvements in ROM and functional outcome scores that exceeded the minimal clinically important difference and substantial clinical benefit but inferior to matched controls. This suggests that glenoid reconstruction using a resected humeral head autograft is an effective strategy when conducting primary rTSA in patients with significant glenoid deformity.

Stratification of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex.

BACKGROUND: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS: A total of 5851 total shoulder arthroplasties (TSAs) including aTSA (n = 2236) and rTSA (n = 3615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

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.

Impact of mental health on outcomes after total shoulder arthroplasty.

BACKGROUND: Anxiety and depression are the 2 most commonly diagnosed psychiatric disorders in the United States. The effect of these disorders on total shoulder arthroplasty (TSA) outcomes must be appreciated. The purpose of this study was to examine the correlation between a preoperative diagnosis of anxiety and depression and postoperative outcomes after TSA. The secondary goals were to determine whether patients contemporaneously treated with medication for their mental health diagnosis fared better than a cohort treated without medication and to examine the degree to which Patient-Reported Outcomes Measurement Information System Mental Health (PROMIS-MH) scores correlate with patient outcomes. Our hypothesis was that a history of anxiety and/or depression would negatively impact patient outcomes after TSA. METHODS: We performed a retrospective analysis of a prospectively collected cohort at a single institution. Patients undergoing anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) with anxiety and/or depression were identified and compared with a cohort of patients without a mental health diagnosis enrolled in an institutional registry from 2011 to 2020. Demographic characteristics, diagnoses, implant types, range of motion, adverse events, and clinical outcome metric scores-PROMIS-MH score, American Shoulder and Elbow Surgeons score, Constant score, Shoulder Arthroplasty Smart Score-were recorded. Outcomes between cohorts were analyzed using conventional statistics, as well as stratification by the minimal clinically important difference and substantial clinical benefit thresholds where applicable. RESULTS: The study comprised 218 patients (114 rTSA and 95 aTSA patients) with a diagnosis of either anxiety and/or depression and 378 patients (153 rTSA and 217 aTSA patients) with no history. Although both cohorts achieved the minimal clinically important difference and substantial clinical benefit thresholds for the postoperative American Shoulder and Elbow Surgeons score, the cohort with anxiety and/or depression showed lower postoperative outcome scores (P < .05), higher AE rates, and significantly lower preoperative-to-postoperative differences in all variables when compared with the cohort without anxiety and/or depression. There were no differences in outcome scores after rTSA or aTSA between patients being treated for anxiety and/or depression and those not receiving treatment. The PROMIS-MH score was positively correlated with postoperative outcomes and patient satisfaction. CONCLUSION: This study shows that patients with anxiety and/or depression who underwent TSA had inferior postoperative outcomes and higher rates of AEs compared with a cohort without a mental health diagnosis. In addition, patients taking medication for treatment of depression and/or anxiety did not gain any significant benefit in terms of their postoperative shoulder outcomes or satisfaction rate compared with those with this diagnosis but not taking medication. Additionally, we found that, independent of a patient's underlying shoulder pathology or psychiatric diagnosis, lower PROMIS-MH scores were correlated with worse postoperative outcomes.

Impact of cervical spine pathology on outcomes after total shoulder arthroplasty.

BACKGROUND: Cervical spine pathology can affect the supporting muscles and function of the shoulder and contribute to shoulder and arm pain and hence may impact postoperative outcomes following shoulder arthroplasty. The purpose of this study was to evaluate the impact of a history of cervical spine arthrodesis and its timing, before or after total shoulder arthroplasty (TSA), on the outcomes of TSA. Our hypothesis is that a history of cervical arthrodesis (CA) will negatively impact patient outcomes after shoulder arthroplasty. METHODS: A retrospective analysis was performed on a prospectively collected cohort at a single institution. Anatomic (aTSA) and reverse TSA (rTSA) patients with CA were identified and compared to a cohort of patients without CA (NCA) enrolled in an institutional registry from 2011 to 2020. Demographic characteristics, diagnoses, implant type, range of motion, adverse events, and clinical outcome metric scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], Constant, Shoulder Function score, patient satisfaction) were recorded. Outcomes between cohorts were analyzed using conventional statistics as well as stratification by minimal clinically important difference and substantial clinical benefit (SCB) thresholds where applicable. RESULTS: Of the 573 TSAs evaluated, 48 (20a CA-aTSA and 28 CA-rTSA) had a history of CA and 525 (280 NCA-aTSA and 245 NCA-rTSA) had no history of CA. The CA-TSA (aTSA and rTSA) had lower Constant, ASES, and Shoulder Function scores postoperatively as well as less improvement in active external rotation and an overall lower satisfaction rating (P < .05 for all) compared with NCA-TSA. The adverse event rate in the CA-TSA cohort was higher compared with the NCA-TSA cohort (25% vs. 6.5% [rTSA; P = .004] and 24.5% vs. 11% [aTSA; P = .068]). Optimal cutoff analysis showed that a time from CA to TSA of greater than 1.33 years had a sensitivity of 75.0% and specificity of 75.0% in predicting achievement of SCB for ASES score. CONCLUSION: The current study demonstrates that patients with a history of CA undergoing shoulder arthroplasty results in lower postoperative functional outcomes, lower satisfaction, and higher rates of postoperative adverse events requiring surgical revision when compared to a cohort without a history of CA. Additionally, the current study demonstrates that a time interval of at least 16 months between CA and shoulder arthroplasty optimizes the chances of achieving SCB for ASES score.