Predictors of patient satisfaction and outcomes following reverse total shoulder arthroplasty

BackgroundObjective clinical outcomes and patient satisfaction via patient reported outcome measures (PROMs) can vary following reverse total shoulder arthroplasty (rTSA). The purpose of this study was to analyze patient specific preoperative factors that may predict postoperative PROMs and satisfaction following rTSA.MethodProspective data was collected on 144 consecutive patients who underwent primary rTSA at our institution between 2012 and 2018, all with minimum 2 year follow-up. Age, gender, race, BMI, previous surgery on the index shoulder, and comorbidity burden were analyzed as potential predictors. Shoulder specific clinical measures were collected both pre- and postoperatively via range of motion testing with active abduction, internal, and external rotation. PROMs included global shoulder function, Simple Shoulder Test (SST) and the American Shoulder and Elbow Surgeons (ASES) scoring systems, and cumulative patient satisfaction. Statistical analysis included comparison of pre- and postoperative outcome measures across the cohort as a whole and between each of the potential predictors in question. The relationship between predictors and postoperative cumulative satisfaction was investigated, with specific attention to identify the strongest predictors and account for confounding variables. Statistical significance was determined at P < .05.ResultsAll range of motion scores and PROMs were significantly improved from preoperative to postoperative assessment. Patient satisfaction was excellent with 92% rating their shoulder as “much better” or “better.” Women and minority patients displayed significantly worse preoperative active abduction, SST, and ASES, but were found to have no significant difference in these measures postoperatively. Younger age was associated with a significantly worse postoperative ASES score. Female sex was associated with significantly higher postoperative satisfaction, while minority status was associated with significantly lower cumulative satisfaction. Postoperative global shoulder function, SST, and ASES were not significantly influenced by sex, race, previous surgery, BMI, or comorbidity burden. Postoperative ASES and global shoulder function demonstrated to be independent predictors of “much better” satisfaction rating.ConclusionPostoperative PROMs and cumulative satisfaction are not influenced by BMI, previous surgery, or comorbidity burden in our cohort. Relative to their respective counterparts, older patients, females, and white patients are more likely to demonstrate higher satisfaction with their outcome following rTSA as measured by PROMs or cumulative satisfaction. Improvements in the ASES and global shoulder function scores most consistently predict higher postoperative satisfaction.Level of evidenceLevel IV; Case Series; Treatment Study     

Development of a predictive model for a machine learning–derived shoulder arthroplasty clinical outcome score

BackgroundWe use machine learning to create predictive models from preoperative data to predict the Shoulder Arthroplasty Smart (SAS) score, the American Shoulder and Elbow Surgeons (ASES) score, and the Constant score at multiple postoperative time points and compare the accuracy of each algorithm for anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA).MethodsClinical data from 2270 patients who underwent aTSA and 4198 patients who underwent rTSA were analyzed using 3 supervised machine learning techniques to create predictive models for the SAS, ASES, and Constant scores at 6 different postoperative time points using a full input feature set and the 2 different minimal feature sets. Mean absolute errors (MAEs) quantified the difference between actual and predicted outcome scores for each model at each postoperative time point. The performance of each model was also quantified by its ability to predict improvement greater than the minimal clinically important difference (MCID) and the substantial clinical benefit (SCB) patient satisfaction thresholds for each outcome measure at 2-3 years after surgery.ResultsAll 3 machine learning techniques were more accurate at predicting aTSA and rTSA outcomes using the SAS score (aTSA: ±7.41 MAE; rTSA: ±7.79 MAE), followed by the Constant score (aTSA: ±8.32 MAE; rTSA: ±8.30 MAE) and finally the ASES score (aTSA: ±10.86 MAE; rTSA: ±10.60 MAE). These prediction accuracy trends were maintained across the 3 different model input categories for each of the SAS, ASES, and Constant models at each postoperative time point. For patients who underwent aTSA, the XGBoost predictive models achieved 94%-97% accuracy in MCID with an area under the receiver operating curve (AUROC) between 0.90-0.97 and 89%-94% accuracy in SCB with an AUROC between 0.89-0.92 for the 3 clinical scores using the full feature set of inputs. For patients who underwent rTSA, the XGBoost predictive models achieved 95%-99% accuracy in MCID with an AUROC between 0.88-0.96 and 88%-92% accuracy in SCB with an AUROC between 0.81-0.89 for the 3 clinical scores using the full feature set of inputs.DiscussionOur study demonstrated that the SAS score predictions are more accurate than the ASES and Constant predictions for multiple supervised machine learning techniques, despite requiring fewer input data for the SAS model. In addition, we predicted which patients will and will not achieve clinical improvement that exceeds the MCID and SCB thresholds for each score; this highly accurate predictive capability effectively risk-stratifies patients for a variety of outcome measures using only preoperative data.Level of evidenceLevel III; Retrospective Comparative Study     

Establishing thresholds for achievement of clinically significant satisfaction at two years following shoulder arthroplasty: the patient acceptable symptomatic state

BackgroundThe patient acceptable symptomatic state (PASS) represents clinical improvement following surgery that patients deem as satisfactory; however, thresholds for achieving this clinical benchmark have not yet been established beyond 1 year following primary and reverse shoulder arthroplasty.MethodsA prospectively maintained registry was retrospectively queried for patients undergoing either a primary TSA or RTSA at a single institution between November, 2015 and October, 2017. All patients completed the ASES, SANE, and Constant patient-reported outcome (PRO) scores at the 2-year time point. PASS threshold scores were calculated using anchor-based methodology with subsequent calculation of achievement rates. Multivariate logistic regression was used to identify demographic and clinical variables associated with the likelihood of PASS achievement.ResultsA total of 93 TSA (mean age 61.4 ± 8.5 years, 32.3% female) and 111 RTSA (mean age 70.0 ± 8.1 years, 51.4% female) patients met final inclusion criteria. One-hundred sixty-five patients (80.8%) responded to the binary anchor question as “satisfied” regarding their surgical outcome. The PASS cutoffs for ASES, SANE, and Constant were 81.7, 85.7, and 24.0, respectively (AUC > 80%), with PASS achievement rates ranging from 50.7% to 59.9% for the entire study population and 66.7% to 83.3% for a risk-stratified subgroup. Patients undergoing TSA had a significantly higher PASS achievement rate relative to RTSA (P = .010) for ASES. Independent risk factors for decreased PASS achievement included lower preoperative PRO score, prior shoulder surgery, sedentary lifestyle, smoking, workers’ compensation status, and diabetes mellitus (DM).ConclusionThe majority of patients reach the PASS benchmark by 2 years after shoulder arthroplasty, with an optimal subgroup of risk-stratified patients achieving PASS at a rate greater than 80% for ASES. Patients undergoing TSA have a higher likelihood of reaching the PASS than patients undergoing RTSA, independent of other variables. Lower baseline outcome scores, prior shoulder surgery, smoking, and sedentary lifestyle are associated with lower PASS rates after TSA. Worker's compensation status and comorbid DM are predictive of reduced PASS rates after RTSA. Primary diagnosis and glenoid morphology did not have a significant impact on the rate of achieving the PASS. This information is valuable for patient selection and counseling prior to shoulder arthroplasty.Level of EvidenceLevel III; Prognostic Study; Retrospective Case Series.     

Reverse shoulder arthroplasty for proximal humeral fractures: better clinical midterm outcome after primary reverse arthroplasty versus secondary reverse arthroplasty after failed ORIF in the elderly

BackgroundJoint replacement surgery as a treatment for complex proximal humeral fractures is an established option, especially in the elderly. In light of the increased attention to reverse total shoulder arthroplasty (rTSA), this study has analyzed the outcomes of patients with primary reverse arthroplasty and after secondary reverse arthroplasty for failed osteosynthesis.MethodsWe retrospectively reviewed 57 patients with an average age of 76 years (min. 55; max. 94; SD 7) from 2010 and 2015 who underwent primary rTSA (30) and secondary rTSA after the failure of plate osteosynthesis (27) after proximal humeral fractures. The functional outcome of the operated shoulder was evaluated by clinical scores (Constant-Score, ASES, DASH and Oxford), range of motion (RoM), pain and activity level.ResultsPrimary rTSA had a significantly better functional outcome, mean-follow-up 37.3 months, measured by Constant-Score (57.13 vs 45.78 points; p= .015) compared to secondary RTSA, mean follow-up 42.1 months. A significantly better active abduction (P= .002), forward flexion (P = .003) and internal rotation (P = .037) was observed in the primary rTSA group, especially in the follow-up > 35 months.ConclusionReverse shoulder arthroplasty is an effective treatment for proximal humeral fractures as primary or revision surgery. The reliable clinical outcome especially in the follow-up to 40 months after primary reverse arthroplasty may suggest to prefer rTSA for complex humeral fractures in the elderly.Level of evidenceLevel III; Retrospective comparative study     

Midterm outcomes of revision shoulder arthroplasty

BackgroundSince the introduction of shoulder arthroplasty, the indications have been expanding. Because of the increasing number of arthroplasty procedures, revision surgeries are also inevitable. The purpose of our study is to delineate a large number of revision shoulder arthroplasty cases treated in different ways, including antibiotic spacer placement (ABX), hemiarthroplasty (HA), anatomic total shoulder arthroplasty (aTSA), and reverse total shoulder arthroplasty (rTSA), and to analyze the relationship between preoperative factors and clinical outcomes.MethodsWe reviewed our institution's records of revision shoulder arthroplasty between January 1, 2000, and October 1, 2017. Preoperative information included age at the time of surgery, gender, body mass index, and infection status. Pre- and postoperatively, we gathered 6 patient-reported clinical outcomes and 3 range-of-motion parameters (elevation, abduction, and external rotation). Postoperative complications were also assessed. Then, we examined the differences between the pre- and postoperative outcomes. As a secondary analysis, we performed multivariable regression analysis on the same outcomes, accounting for age at the time of surgery, infection status, and previous surgery type.ResultsAmong the 341 revisions performed, 138 cases met inclusion criteria of at least a 2-year follow-up with pre- and postoperative functional outcome scores. The majority of our revision procedures were to a rTSA (92 cases, 67%), followed by aTSA (28 cases, 20%), and ABX/HA (18 cases, 13%). The mean age at the time of our index surgery was 66 years old. In aTSA and rTSA, all the postoperative outcomes (ie, ASES, Constant, UCLA, SST, SPADI, SF-12 scores, and 3 AROMs) were significantly improved beyond the minimal clinically important difference (MCID) except SF-12 scores in aTSA (P = .25) and active external rotation in rTSA (P = .73). None of the ABX/HA's postoperative outcomes achieve significant improvement or MCID. Multivariable regression analysis showed that older age at the time of surgery was significantly associated with better outcomes in 3 of the 6 patient-reported outcomes (ASES, SST, and SPADI; P = .023, .023, and .028, respectively).ConclusionRevision aTSA and rTSA showed statistically and clinically significant improvement postoperatively. ABX and HA did not achieve meaningful postoperative improvement. Overall, patients getting revision shoulder arthroplasty at an older age had better patient-reported outcomes.Level of evidenceLevel III; Retrospective Cohort Study     

Understanding the variables that are associated with failure to achieve an acceptable symptom state after reverse shoulder arthroplasty

BackgroundThe patient acceptable symptom state (PASS) was developed to improve the subjective interpretation of patient reported outcomes (PROs) and the minimum score necessary for the patient to “feel good.” The purpose of this study was to compare range of motion (ROM), final PROs, and individual responses on PROs between patients achieving or failing to meet a PASS after reverse shoulder arthroplasty (RSA).MethodsA retrospective review of multi-center prospectively maintained database of RSAs between 2015 and 2018 was conducted. Primary RSAs with minimum 2-year follow-up were included. Patients were stratified into 2 groups by whether they achieved or failed to meet PASS scores at a minimum of 2 years of 76 for the ASES score or 75.5 for the SANE score. The primary goals of the study were to compare outcomes, range of motion (ROM) and individual ASES and WOOS survey responses for patients above and below the PASS score.Results87 patients were included. Using the ASES cutoff for PASS, 33% failed to meet a PASS while 45% failed to meet a PASS defined by the SANE. The most notable difference between patients above and below ASES PASS was a significant difference in VAS pain scores (3.1 vs. 0.3; P < .001). Overall, ROM was similar between patients above and below the ASES PASS, with slight, but statistically improved rotational motion in those achieving an ASES PASS (ER(90) 14 degrees improved, P = .005, IR(90) 10 degrees improved, P = .011). Similarly, patients failing to meet the SANE PASS had twice as high VAS pain scores (1.9 vs. 0.8; P = .017). Patients failing to meet the ASES PASS had almost universally statistically higher rates of reporting “very difficult” or “unable to do” for pain, ADL and work/sports questions on the ASES and globally more symptoms on every domain of questions for the WOOS. Similarly, for the PASS defined by SANE, patients reported higher levels of pain and dysfunction on nearly every question and domain of the ASES and WOOS.ConclusionsAt least one quarter of patients do not achieve a PASS after RSA. Pain appears to be the primary driver for this finding, while ROM is very similar between patients achieving or failing to meet a PASS regardless of PRO used to define the PASS. Patients who fail to achieve PASS after RSA report doing poorly in all domains of their outcome.Level of evidenceLevel III; Retrospective Comparative Study     

Prospective observational study of anatomic and reverse total shoulder arthroplasty using a single implant system with long-term follow-up

BackgroundBoth anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) are the standard of care for various end-stage degenerative conditions of the glenohumeral joint. The purpose of this prospective study was to compare clinical outcomes of aTSA and rTSA using the same platform total shoulder arthroplasty system at a minimum follow-up of 8 years.MethodsAn international multicenter data registry was used to identify patients undergoing primary aTSA or rTSA with a minimum of 8-year follow-up. Patients were scored preoperatively and at latest follow-up using 6 outcome and 4 range of motion metrics. Patients graded global shoulder function on a 0-10 scale. Patient satisfaction was classified as much better, better, unchanged, or worse. Pain was graded using the Visual Analog Scale. A student’s 2-tailed paired t-test, Chi-squared test, or Wilcoxon rank-sum test were used when appropriate, where P < .05 indicates significant differences.ResultsA total of 364 aTSA patients and 278 rTSA patients were included. rTSA had greater mean age (aTSA 65.1, rTSA 71.2, P < .0001) and shorter mean follow-up (aTSA 115.2 months, rTSA 109.7 months; P = .0002). Postoperatively, all patients demonstrated significant improvements in pain and function. Preoperatively, aTSA patients had greater active abduction and forward elevation, global function, Constant Score, and the University of California, Los Angeles score. At latest follow-up, aTSA had greater active abduction, forward elevation, external rotation, and Simple Shoulder Test scores. There were no postoperative differences in patient satisfaction, shoulder function, pain, or any other outcome measure between the groups. aTSA patients had a greater revision rate (aTSA 5.8%, rTSA 1.8%; P = .0114), with no difference in complication rates. Humeral radiolucent lines were present in 20.9% of aTSA patients and 37.1% of rTSA patients (P = .0011). Glenoid radiolucent lines were present in 48.0% of aTSA patients (average score of 1.5). Scapular notching was present in 14.5% of rTSA patients (average grade of 0.26).ConclusionThis study is one of the largest to date that compares aTSA and rTSA with a minimum follow-up of 8 years. Significant improvements are seen in both aTSA and rTSA. For both groups, the complication rate was lower than previously reported in the literature. At the latest follow-up, pain relief and global function were significantly improved with high patient satisfaction in both groups, with no statistical differences found. This study provides physicians with information to help guide them when advising patients as to what they can expect at a minimum of 8 years after aTSA and rTSA.     

The influence of preoperative teres minor muscle fatty degeneration on active external rotation following reverse total shoulder arthroplasty

BackgroundReverse total shoulder arthroplasty (rTSA) improves shoulder elevation in patients treated for cuff tear arthropathy (CTA) or irreparable massive cuff tears. Patient satisfaction can be limited by reduced active external rotation (AER). Rotator cuff muscles that externally rotate the shoulder are infraspinatus and teres minor (TM).AimThe purpose of this study was to assess the correlation between preoperative TM fatty degeneration and postoperative AER after rTSA performed for CTA or irreparable cuff tears.MethodsConstant scores and active range of motion were consecutively collected for 109 shoulders in 97 patients (mean: 75.73 ± 8.94 years; 31 male, 66 female) over a 10-year period. AER was evaluated with the humerus in adduction (AER1) and in abduction. TM muscle atrophy was scored according to Goutallier's classification, assessed on preoperative computed tomography scans.ResultsMultivariate analysis showed that TM fatty infiltration was a predictor of AER1. AER1 decreased by 4.9 degrees preoperatively and by 6.4 degrees at the final follow-up, for each increment in Goutallier grade (P = .02). Postoperatively, AER evaluated with humerus in abduction improved significantly (P < .001), but did not correlate with TM Goutallier grade. At a mean follow-up of 38 months (range: 24 to 96), mean Constant score improved from 20.5 ± 11.1 to 68.4 ± 14.9 (P < .001), as did shoulder active range of motion in all planes including AER1 (P < .001).ConclusionThis is the first study to quantify the inverse correlation between AER and TM Goutallier grade, both preoperatively and after rTSA; this information guides prognosis for patients with TM degeneration undergoing rTSA. Further studies are necessary to have a better understanding and find reliable solutions.Level of evidenceLevel III; Case Series     

Anatomic vs. reverse shoulder arthroplasty for glenohumeral osteoarthritis with intact rotator cuff: a retrospective comparison of patient-reported outcomes using the systems outcomes database with up to 5-year follow-up

BackgroundThe growing enthusiasm for the use of reverse shoulder arthroplasty (RSA) in the treatment of primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff is based on data derived from single-center studies with limited generalizability and follow-up. This study compared patient-reported outcomes (PROs) between RSA and total shoulder arthroplasty (TSA) for the treatment of primary GHOA with up to 5-year follow-up and examined temporal trends in the treatment of GHOA between 2012 and 2021.MethodsA retrospective review was performed on patients with primary GHOA undergoing primary arthroplasty surgery from the Surgical Outcomes System global registry between 2012 and 2021. PROs including the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE) score, and visual analog scale (VAS) for pain were compared between RSA and TSA at 1, 2, and 5 years postoperatively.ResultsA total of 4451 patients were included, with 2693 (60.5%) undergoing TSA and 1758 (39.5%) undergoing RSA. Both RSA and TSA provided clinically excellent outcomes at 1 year postoperatively (ASES: 80.8 ± 17.9 vs. 85.9 ± 15.2, respectively; SANE: 74.8 ± 24.7 vs. 79.5 ± 22.9; VAS pain: 1.3 ± 2.0 vs. 1.1 ± 1.7; all P < .05) that were maintained at 2 years (ASES: 81.3 ± 19.3 vs. 87.3 ± 14.9; SANE: 74.8 ± 26.2 vs. 79.7 ± 24.7; VAS pain: 1.3 ± 2.1 vs. 1.0 ± 1.6; all P < .05) and 5 years (ASES: 81.7 ± 16.5 vs. 86.9 ± 15.3; SANE: 71.6 ± 28.5 vs. 78.2 ± 25.9; VAS pain: 1.0 ± 1.7 vs. 1.0 ± 1.7; all P < .05), with statistical significance favoring TSA. After controlling for age and sex, there was an adjusted difference of 4.5 units in the ASES score favoring TSA (P = .005) at 5 years postoperatively but no differences in adjusted SANE (P = .745) and VAS pain (P = .332) scores. The use of RSA for GHOA grew considerably over time, from representing only 17% of all replacements performed for GHOA in 2012 to nearly half (47%) in 2021 (P < .001).ConclusionRSA as a treatment for GHOA with an intact rotator cuff seems to yield PROs that are largely clinically equivalent to TSA extending to 5 years postoperatively. The observed statistical significance favoring TSA appears to be of marginal clinical benefit based on established minimal clinically important differences and may be a result of the large sample size. Further research using more granular clinical data and examining differences in range of motion and complications is warranted as it may change the value analysis.     

Outcomes of nonoperative management of acromial stress fractures after reverse shoulder arthroplasty

IntroductionAcromial stress fractures (ASF) and stress reactions (ASR) are common complications after reverse shoulder arthroplasty (RSA), and have been shown to compromise outcomes. The purpose of this study was to determine the functional outcomes of patients with ASF and ASR treated nonoperatively.MethodsA total of 958 patients that underwent RSA were retrospectively reviewed. 43 (4.5%) were found to have ASF and 56 (5.7%) were found to have ASR. ASF were defined by tenderness over the acromion with identified fracture on radiographic imaging, and ASR was defined as tenderness without radiographic evidence of fracture. Functional outcomes were assessed via American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test (SST) and VAS (Visual Analog scale) pain at a minimum of 2 years after RSA and one year from diagnosis of acromial pathology. The ASF patients were matched 3:1 to RSA controls without acromial pathology based on age, sex, indication, and implant.ResultsTwenty seven ASF and 35 ASR patients met inclusion criteria with a mean follow-up of 50.3 months after surgery (range: 24-108 months). Symptom onset after RSA occurred at 8.1 ± 8.9 months (range: 0.8-49.8) in ASFs and 7.5 ± 6.8 months (range: 1.0-41.3) in ASRs (P = .700). The ASF group included 20 (74%) females with an average age of 71.8 years, and the ASR group included 30 (86%) females with an average age of 72.9 years. ASF patients had inferior outcomes compared to controls in ASES (57.8 vs. 76.0, P = .001), SANE (59.1 vs. 78.8, P = .001), SST (5.1 vs. 7.5, P = .001), and VAS (3.3 vs. 1.2, P = .002). Additionally, ASF patients had significantly worse scores compared to ASR patients by VAS Pain (3.3 vs 1.7, P = .020), ASES (57.8 vs. 76.7, P = .001), SANE (59.1 vs. 81.1, P = .001), and SST (5.1 vs. 7.5, P = .001). Patients with ASR had comparable pain and function to controls in ASES (P = .858), SANE (P = .508), SST (P = .956), and VAS (P = .264) scores. Twenty-one (77.7%) ASF patients experienced fracture displacement and 13 (48.1%) went on to nonunion.ConclusionEarly follow-up of patients treated nonsurgically for ASF after RSA demonstrated worse pain and function compared to controls. The majority demonstrated further displacement after diagnosis and almost half developed a nonunion. Patients with ASR experienced temporary dysfunction with little impact on final outcome. Strategies to prevent and treat ASFs remain an area in need of innovation.Level of evidenceLevel IV; Case series     

Cause for revision differs between a short and standard length stem at 5 year follow-up

BackgroundThe purpose of this study was to compare the 5 year radiographic and clinical outcomes of anatomic total shoulder arthroplasties (TSA) performed with either a standard length (SL) or short stem. The hypothesis was there would be no difference in radiographic or clinical outcomes based on stem length.MethodsA multicenter retrospective review was performed of primary TSAs performed with a press-fit humeral component. Fifty SL and 72 short stems were available for review, of which 43 SL and 60 short stems had minimum 5 year follow-up. Functional outcome was assessed according to range of motion (ROM), visual analog scale (VAS) American Shoulder and Elbow Surgeons (ASES), and Single Assessment Numeric Evaluation (SANE) scores. Radiographs were reviewed for signs of humeral component loosening and stress shielding.ResultsAt final follow-up there were no differences in ROM, or ASES or SANE scores between groups (P>.05). Postoperative VAS scores were lower in the SL compared to the short stems (0.8 vs. 1.6; P = .053). All-cause revision was similar between the SL and short stems (16% vs. 22.2%; P = .395). Among SL stems there were no revisions for humeral loosening and none were considered radiographically at risk. Six short stems were revised for loosening (8.3%; P =.036 vs. SL). An additional 5 short stems were considered to be radiographically at risk for loosening for a total revision or at risk rate of 15.3% (P = .003 vs. SL).ConclusionThere is no difference in functional outcome at mid-term follow-up of TSA based on stem length with a grit-blasted humeral component. Revision for loosening and radiographic risk for loosening may be higher with a short stem compared a standard length humeral stem placed with press-fit fixation using grit blasting.Level of evidenceLevel III; Retrospective Comparative Study.     

Using inertial measurement units to quantify shoulder elevation after reverse total shoulder arthroplasty: a pilot study comparing goniometric measures captured clinically to inertial measures captured ‘in-the-wild’

BackgroundReverse total shoulder arthroplasty (rTSA) is utilized for a variety of indications, but most commonly for patients with rotator cuff arthropathy. This procedure reduces pain, improves satisfaction, and increases clinically measured range of motion (ROM). However, traditional clinical ROM measurements captured via goniometer may not accurately represent ‘real-world’ utilization of ROM. In contrast, inertial measurement units (IMUs) are useful for establishing ROM outside the clinical setting. We sought to measure ‘real-world’ ROM after rTSA using IMUs.MethodsA previously validated IMU-based method for continuously capturing shoulder elevation was used to assess 10 individuals receiving rTSA (1M, 82 ± 5 years) and compared to a previously captured 10 healthy individuals (4M, 69 ± 20 years) without shoulder dysfunction. Control subject data were previously collected over 1 week of continuous use. Patients undergoing rTSA donned sensors for 1 week pre-rTSA, 6 weeks at 3 months post-rTSA following clearance to perform active-independent ROM, and 1 week at 1 year and 2 years post-rTSA. Shoulder elevation was computed continuously each day. Daily continuous elevation was broken into 5° angle ‘bins’ (eg, 0-5°, 5-10°, etc.) and converted to percentage of the total day. IMU-based outcome measures were ROM binned percent (as described previously) and maximum/average elevation each week. Clinical goniometric ROM and patient-reported outcome measures were also captured.ResultsNo differences existed between patient and healthy control demographics. While patients showed improvement in American Shoulder and Elbow Surgeon (ASES) score, pain score, and goniometric ROM, IMU-based average and maximum elevation were equal between control subjects and patients both pre- and post-rTSA. The percent of time spent above 90° was equal between cohorts pre-rTSA, rose significantly at 3 months post-rTSA, and returned to preoperative levels thereafter.DiscussionAlthough pain, satisfaction, and ROM measured clinically may improve following rTSA, real-world utilization of improved ROM was not seen herein. Improvements during the acute rehabilitation phase may be transient, indicating longer or more specific rehabilitation protocols are necessary to see chronic improvements in post-rTSA movement patterns.     

Treatment of massive irreparable rotator cuff tears without arthritis: a comparison of superior capsular reconstruction,partial rotator cuff repair,and reverse total shoulder arthroplasty

BackgroundTo compare outcomes of superior capsular reconstruction (SCR), partial rotator cuff repair (PR), and reverse total shoulder arthroplasty (rTSA) for massive irreparable rotator cuff tear (MIRCT) without arthritis at more than 2 years follow-up.MethodsA retrospective analysis of prospectively collected data of consecutive patients undergoing surgical treatment for intraoperatively confirmed MIRCT without arthritis using SCR, PR, or rTSA. Preoperative and postoperative data were collected and multivariate analysis performed.ResultsThirty two patients met inclusion criteria for SCR, 24 for PR, and 42 for rTSA (mean follow-up years: SCR 3.2; PR 4.0; rTSA 3.5; P = .02). The rTSA patients were older (66.2 years; SCR 57.3; PR 59.0; P = .0001) and more likely to be female (61.9%; SCR 12.5%; PR 25.0%; P < .001). Intraoperative evaluation demonstrated full thickness subscapularis tear in 37.5% for SCR, 4.2% for PR, and 21.4% for rTSA (P = .01). Pseudoparalysis was present in 18.8% of SCR, 0% of PR, and 14.3% of rTSA patients (P = .08). All groups saw postoperative improvement in strength and patient-reported outcomes (P < .036). SCR and rTSA demonstrated an improved forward elevation range of motion (ROM) postoperatively while PR did not (P = .96). No group experienced improvement in rotation ROM (P > .12). rTSA had worse postoperative ROM in all planes compared to SCR and PR (P < .003). There were no differences between groups in postoperative strength (P > .16) or patient-reported outcomes (American Shoulder and Elbow Surgeons P = .14; visual analog scale P = .86; single assessment numeric evaluation P = .61). Patients were satisfied in 81.2% of SCR cases, 87.5% of PR, and 95.3% of rTSA (P = .33). Three of 32 (9.4%) SCR patients required conversion to rTSA, while 3 of 24 (12.5%) PR patients required reoperation (2 revision repairs; 1 conversion to rTSA). There were 3 additional surgical complications among 42 rTSA patients (7.1%). There were 4 nonsurgical complications in the SCR group and 1 in the rTSA group. One SCR patient and 3 rTSA patients were deceased. Multivariate analysis demonstrated no independent predictors of revision surgery. An increased acromiohumeral interval distance was an independent predictor of improved postoperative strength for all groups (P < .02).ConclusionSCR, PR, and rTSA for the treatment of MIRCT without arthritis all significantly improved postoperative strength and outcomes scores with >80% patient satisfaction but with rTSA having worse postoperative motion and a higher complication rate. There were no independent predictors for revision surgery. SCR, PR and rTSA are all viable operations for MIRCT without arthritis with satisfactory results maintained at 2 years postoperatively.     

Demographic and radiographic predictors of patient reported outcomes and revision surgery after stemless total shoulder arthroplasty

BackgroundStemless total shoulder arthroplasty (TSA) is aimed at better re-creating native anatomy, facilitating revision, and preserving bone. The purpose of this study is to determine which pre-operative patient characteristics or radiographic parameters were predictive of outcomes following stemless TSA.MethodsThis was a retrospective review of prospectively collected data. One hundred fifty-seven patients with glenohumeral osteoarthritis were prospectively enrolled as part of a multi-center FDA Investigational Device Exemption protocol in July 2011-November 2012. In the present study, one hundred forty-nine patients with minimum 2-year follow-up had imaging available for review and were included (107 men, 42 women). Mean age 65 years (range,37-84). Pre-operative patient demographics, baseline ASES and Constant scores, deltoid tuberosity index (DTI), combined cortical thickness, and postoperative glenoid version were analyzed to predict treatment success. Treatment success was defined by no revision procedures and an adjusted Constant score of >85% at final follow-up. Statistical analyses were performed using student T-test, multiple logistic regression, and Pearson correlation with a p-value of 0.05 defining significance. Intraclass correlation and kappa values were calculated to determine interrater reliability for radiographic measurements.ResultsThree patients (2.0%) underwent revision or explant due to infection, unstable implant, or glenoid loosening. Eleven (7.4%) had an adjusted Constant score <85% at 2-year follow-up. These patients made up the suboptimal treatment outcome cohort (n = 13), with a mean age of 55.5 compared to 66.6(P <0.001). Relative risk for suboptimal outcome for patients <60 years was 1.32(95% CI:1.05-1.66). Baseline Constant was lower in the suboptimal treatment group (47.9 vs. 57.0, p=0.001). There were no differences between groups when comparing radiographic parameters. Older age correlated with lower combined cortical thickness (r = 0.32, P <0.05), lower DTI(r = 0.17, P <0.05), greater Constant(r = 0.47, P <0.05) and ASES(r = 0.29, P <0.05) scores at follow-up.ConclusionPatients younger than 60 years old had a 1.3x risk of suboptimal treatment outcome following stemless TSA, similar to what is seen with stemmed implants. Low radiographic bone density was not predictive of suboptimal constant score or reoperation at final follow-up. Older patients had decreased combined cortical thickness and deltoid tuberosity index, yet were more likely to have a successful outcome following stemless TSA compared to younger patients.Level of evidenceLevel III; Retrospective Cohort     

Anatomic versus reverse shoulder arthroplasty for post-traumatic sequelae of operatively and nonoperatively treated proximal humerus fractures

BackgroundThis study aimed to determine whether there is a long-term difference in outcomes between anatomic total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA) performed for proximal humerus fracture (PHF) sequelae. Hypotheses were as follows: (1) patients undergoing aTSA would have improved functional outcomes but a greater incidence of adverse events (AEs) and reoperation than those undergoing rTSA and (2) patients undergoing shoulder arthroplasty after open reduction internal fixation (ORIF) would have worse outcomes with more AEs and reoperations than those undergoing shoulder arthroplasty for sequelae of nonoperatively managed PHF.MethodsA prospectively collected database was queried for patients with PHF sequelae undergoing aTSA or rTSA between 2007 and 2020 with minimum 2-year follow-up. Baseline demographics, perioperative data, postoperative AEs, functional outcomes, and range of motion (ROM) were compared between aTSA and rTSA groups. A secondary analysis was performed to compare patients treated with prior PHF ORIF vs. those treated nonoperatively.ResultsThere were 17 patients in the aTSA group and 83 patients in the rTSA group. Type I PHF sequelae predominated among patients who underwent aTSA (71% vs. 40%, P = .026). Incidence of total postoperative AEs was greater after aTSA than that after rTSA (12% vs. 5%, P = .277), with a significantly higher rate of glenoid aseptic loosening after aTSA (6% vs. 0%, P = .026). All AEs required reoperation except one in the rTSA group. The mean follow-up was 66 months for aTSA compared with 45 months for rTSA (P = .002). No differences in functional outcomes or ROM between aTSA and rTSA persisted beyond 3 months or at the final follow-up except external rotation, which favored aTSA for 3 years postoperatively. In the secondary analysis, there were 33 patients in the ORIF group and 67 in the non-ORIF group. One (3%) postoperative AE occurred in the ORIF group vs. five (7%) in the non-ORIF group (P = .385). At a mean follow-up of 4 years, there were no differences in functional outcome scores or ROM between ORIF and non-ORIF groups, except for patient-reported shoulder function (6.3 vs. 7.4, respectively, P = .037).ConclusionFor treatment of PHF sequelae, aTSA may result in a higher incidence of postoperative AEs and reoperation than rTSA, particularly due to glenoid aseptic loosening. No difference in functional outcome scores between aTSA and rTSA persists beyond 3 months or at the final follow-up. Although active external rotation is significantly improved after aTSA for the first 3 years postoperatively, no differences in ROM exist beyond 4 years at the final follow-up. Patients undergoing shoulder arthroplasty for PHF sequelae have comparable outcomes regardless of prior ORIF or nonoperative management.Level of evidenceLevel III; Retrospective Cohort Design; Treatment Study     

Anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty for dislocation arthropathy yield comparable functional outcomes with the matched cohort

BackgroundThe aim of this study was to compare outcomes of anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) after prior shoulder stabilization versus matched cohorts without previous stabilization surgery. Hypotheses were as follows: (1) patients undergoing aTSA or rTSA after stabilization procedures would have worse outcomes than matched cohorts and (2) patients undergoing TSA would have better outcomes after soft-tissue stabilization procedures (aTSA_ST or rTSA_ST) than after bony stabilization procedures (aTSA_B or rTSA_B).MethodsRetrospective cohort study was performed comparing (1) 36 patients who underwent aTSA and (2) 32 patients who underwent rTSA with prior shoulder stabilization with 3-to-1 matched cohorts (based on age, gender, and follow-up length) with no prior shoulder instability or surgery. Baseline demographics, perioperative data, adverse events (AEs), radiographic outcomes, functional outcome scores, range of motion (ROM), and patient satisfaction were analyzed. Subgroup analyses compared patients who underwent aTSA_ST or rTSA_ST with patients who underwent aTSA_B or rTSA_B.ResultsThe postoperative AE rate was 8.3% and 4.6% in the aTSA group and matched cohort, respectively (P = .404), with a trend toward a significantly higher incidence of aseptic glenoid loosening in the aTSA group (8.3% vs. 1.9%, P = .067). Functional outcomes, ROM, and patient satisfaction did not differ at follow-up >4 years. In the subgroup analysis, two AEs required reoperation among 25 patients who underwent aTSA_ST versus one among 11 patients who underwent aTSA_B, all related to aseptic loosening. There was a trend toward greater functional outcomes and satisfaction among patients who underwent aTSA_ST. There was a trend toward a clinically significant difference in active abduction at final follow-up favoring aTSA_ST (128 vs. 108 degrees, P = .096).The postoperative AE rate was 6.3% and 4.2% among the rTSA group and matched cohort, respectively (P = .632). Functional outcomes, ROM, and patient satisfaction did not differ at 4-year follow-up. In the subgroup analysis, no AEs were reported among 18 patients who underwent rTSA_ST and 14 patients who underwent rTSA_B. A trend toward greater functional outcomes and patient satisfaction favored patients who underwent rTSA_B, who achieved greater improvements in ROM from baseline and greater ROM in all planes at the final follow-up.ConclusionBoth aTSA and rTSA are reliable options for the treatment of dislocation arthropathy in appropriately selected patients. aTSA and rTSA after prior shoulder stabilization procedures have nearly equal rates of AEs and yield similar clinical and functional outcomes as matched cohorts. There may be an increased risk of glenoid aseptic loosening in aTSA after prior shoulder stabilization. Functional outcomes tend to be greater for patients who underwent aTSA_ST than those for patients who underwent aTSA_B. On the contrary, rTSA may optimize postoperative function when performed for dislocation arthropathy after bony rather than soft-tissue stabilization procedures.Level of evidenceLevel III; Retrospective Cohort Design; Treatment Study     

Effect of subscapularis repair in patients with an intact rotator cuff undergoing reverse total shoulder arthroplasty

BackgroundReverse total shoulder arthroplasty (rTSA) is increasing in popularity worldwide. There remains considerable debate as to whether to repair subscapularis or not following the procedure. Previous research into all indications demonstrates similar outcomes regardless of subscapularis (SSC) repair when using a medial glenoid/lateral humeral implant. The purpose of this study is to assess the effects of SSC repair on postoperative shoulder function and patient reported outcomes scores only in patients with an intact rotator cuff undergoing rTSA.MethodsPatients who underwent a primary rTSA for osteoarthritis with a minimum of 2 years follow-up were identified from an international shoulder registry. Patients with rotator cuff tears, cuff arthropathy, or post-traumatic arthritis were excluded. They were then divided into age and gender matched groups based on whether they had SSC repaired or not; 436 patients were analyzed in total, with 218 in each group. Numerous outcome measures between groups were compared, including active shoulder range of motion, complication rates, and 7 different patient reported shoulder outcome scores, using MCID (Minimal Clinically Important Differences), SCB (Substantial clinical benefit), and a 2 tailed paired T-Test.ResultsIn both groups, improvement in average shoulder movement and patient reported shoulder scores exceeded the threshold of SCB with 93% reporting their symptoms were better or much better in both groups. Those who had SSC repaired demonstrated a statistically significantly better mean active forward flexion (144° vs. 138°, P= .021) and mean internal rotation score (4.8 vs. 4.0, P= <.05), however these differences did not exceed the MCID where available. With regard to patient reported scores, those who had SSC repaired demonstrated a statistically significantly better mean Constant score (71 vs. 68, P= .05) and Shoulder Arthroplasty Smart Score (78 vs. 75, P= <.05), however these differences did not exceed the MCID for either score (5.3 and 6.1 respectively). There was no difference in complication rates between groups, including dislocation.ConclusionThis study demonstrates excellent results following rTSA with a medial glenoid/lateral humeral implant design regardless of whether the SSC was repaired or not. For the majority of patient reported scores and shoulder movements there was no significant difference between SSC repaired and nonrepaired groups, and where statistically significant differences were noted, the difference did not exceed the MCID in any measure.Level of EvidenceLevel III; Retrospective Comparative Study     

Use of machine learning to assess the predictive value of 3 commonly used clinical measures to quantify outcomes after total shoulder arthroplasty

BackgroundAn important psychometric parameter of validity that is rarely assessed is predictive value. In this study we utilize machine learning to analyze the predictive value of 3 commonly used clinical measures to assess 2-year outcomes after total shoulder arthroplasty (TSA).MethodsXGBoost was used to analyze data from 2790 TSA patients and create predictive algorithms for the American Shoulder and Elbow Surgeons (ASES), Constant, and the University of California Los Angeles (UCLA) scores and also quantify the most meaningful predictive features utilized by these measures and for all questions comprising each measure to rank and compare their value to predict 2-year outcomes after TSA.ResultsOur results demonstrate that the ASES, Constant, and UCLA measures rarely considered the most-predictive features relevant to 2-year TSA outcomes and that each outcome measure was composed of questions with different distributions of predictive value. Specifically, the questions composing the UCLA score were of greater predictive value than the Constant questions, and the questions composing the Constant score were of greater predictive value than the ASES questions. We also found the preoperative Shoulder Pain and Disability Index (SPADI) score to be of greater predictive value than the preoperative ASES, Constant, and UCLA scores. Finally, we identified the types of preoperative input questions that were most-predictive (subjective self-assessments of pain and objective measurements of active range of motion and strength) and also those that were least-predictive of 2-year TSA outcomes (subjective task-specific activities of daily living questions).DiscussionMachine learning can quantify the predictive value of the ASES, Constant, and UCLA scores after TSA. Future work should utilize this and related techniques to construct a more efficient and effective clinical outcome measure that incorporates subjective and objective input questions to better account for the preoperative factors that influence postoperative outcomes after TSA.Level of EvidenceLevel III; Retrospective Comparative Study     

Effect of obesity on perioperative and 180-day outcomes following anatomic and reverse total shoulder arthroplasty

BackgroundAn increasing number of anatomic and reverse total shoulder arthroplasties (aTSA and rTSA, respectively) are being performed on obese patients. Current literature shows highly variable results regarding the relationship between obesity and TSA outcomes. The purpose of this study is to more clearly define the effect of obesity on complication rates and outcomes following TSA using large, national databases.MethodsThe Nationwide Inpatient Sample (NIS) database and Nationwide Readmission Database (NRD) were queried from 2011 to 2017 to identify all cases of aTSA and rTSA. These groups were further stratified into non-obese, obese, and morbidly obese cohorts. The NIS database was used to perform a demographic, hospital characteristic analysis, and peri‑operative complication analysis (n = 433,111). The NRD was then used to analyze 180-day rates of complications, revisions, mortality, extended hospital stays, non-home discharges, and overall total cost (n = 303,755).ResultsThe most obese individuals were significantly more likely to be younger, female, black, and have higher comorbidity scores (all P < .001). In the peri‑operative setting, morbid obesity was predictive of higher complication rates compared to non-obese patients following both aTSA and rTSA (both P< .001). Obesity was predictive of increased perioperative complication rates following aTSA (P = .002), but fewer complications following rTSA (P < .001). Morbid obesity was predictive of higher frequencies of 180-day complication rates, extended hospital stays, and non-home discharge following aTSA and rTSA, as well as higher rates of 180-day revision rates following rTSA (all P < .05) compared to non-obese individuals. While obesity was predictive of higher 180-day revision rates following rTSA (P < .001), it was predictive of lower rates of extended hospital stays following aTSA and rTSA (all P < .001), lower non-home discharge rates following rTSA (P = .009), lower 180-day revision rates following aTSA (P < .001), and lower 180-day complication and revision rates following rTSA (both P < .001).ConclusionsWhile obesity was predictive of higher rates of peri‑operative complications following aTSA and 180-day revision rates following rTSA, it otherwise appears to be a safe procedure in the obese population. Morbid obesity, however, appears to be predictive of increased peri‑operative and 180-day complication rates, longer hospital stays, and more frequent non-home discharge rates following TSA. Patients should be counseled appropriately on this information when considering surgery in order to facilitate shared decision making, and surgeons should take particular care when performing TSA in the morbidly obese population.Level of EvidenceLevel III; Retrospective Cohort; Treatment Study     

Which Risk Factors Are Associated with Pain and Patient-reported Function in Patients with a Rotator Cuff Tear?

BackgroundPatient-reported measures guide physicians in clinical decision making and therefore it is critical to determine what clinical factors are associated with these scores. Psychological and physical factors are commonly studied separately in patients with rotator cuff tears to determine their influence on outcomes. It is well established that psychological distress and scapular motion change in the presence of a symptomatic rotator cuff tear. However, these factors have not been studied simultaneously in a clinical setting to determine their association with shoulder outcome scores.Question/purposeAfter controlling for relevant confounding variables, what physical and psychological factors are associated with better (1) American Shoulder and Elbow Surgeons (ASES) scores for function, (2) ASES pain scores, and (3) total ASES scores?MethodsFifty-nine patients with a potential symptomatic rotator cuff tear were recruited and agreed to participate in this cross-sectional study. Of those, 85% (50 of 59) met eligibility criteria for a primary diagnosis of an MRI-confirmed symptomatic partial-thickness or full-thickness rotator cuff tear without a history of shoulder surgery. Demographics, rotator cuff tear size, arm flexion, and clinical scapular motion during active arm flexion were evaluated by experienced examiners using standardized procedures. Patients completed the ASES questionnaire and the Optimal Screening for Prediction of Referral and Outcomes-Yellow Flag assessment form, which measures 11 different pain-related psychological distress symptoms. Three separate stepwise multiple linear regression analyses were performed for ASES pain, function, and total scores, with significance set at p < 0.05.ResultsThis model found that ASES function scores were associated with four factors: older age, increased arm flexion, increased percentage of scapular external rotation during arm flexion, and increased scores for acceptance of chronic pain (adjusted r² = 0.67; p = 0.01). Those four factors appear to explain 67% of the observed variance in ASES function scores in patients with rotator cuff tears. Furthermore, increased percentage of scapular external rotation during arm flexion and decreased fear-avoidance beliefs related to physical activity scores (adjusted r² = 0.36; p < 0.01) were associated with better ASES pain scores. And finally, better ASES total scores were associated with four factors: increased arm flexion, increased percentage of scapular upward rotation, increased scapular external rotation during arm flexion, and decreased fear-avoidance beliefs related to physical activity scores (adjusted r² = 0.65; p < 0.001).ConclusionOur results favor adopting a comprehensive biopsychological clinical assessment for patients with rotator cuff tears that specifically includes humeral and scapular motion, fear-avoidance behaviors, and pain coping behaviors along with demographics. These particular physical and psychological variables were found to be associated with the ASES and, therefore, should be clinically examined simultaneously and targeted as part of a tailored treatment plan.Level of EvidenceLevel II, prognostic study.