Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 648
Filter
1.
BMC Musculoskelet Disord ; 25(1): 17, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38166758

ABSTRACT

BACKGROUND: Various surgical techniques and conservative therapies are useful tools for treating proximal humerus fractures (PHFs), but it is important to understand how to properly utilize them. Therefore, we performed a systematic review and network meta-analysis to compare and rank the efficacy and safety of medical treatments for PHF. METHODS: PubMed, Embase, the Cochrane Library, and the ClinicalTrials.gov databases were systematically searched for eligible randomized controlled trials (RCTs) from inception until June 2022. Conservative therapy-controlled or head-to-head RCTs of open reduction internal fixation (ORIF), intramedullary nailing (IMN), hemiarthroplasty (HA), and reverse total shoulder arthroplasty (RTSA) used for the treatment of adult patients with PHF were included. The surface under the cumulative ranking (SUCRA) probabilities were applied to compare and rank the effects of medical treatments for PHF. RESULTS: Eighteen RCTs involving 1,182 patients with PHF were selected for the final analysis. Mostly baseline characteristics among groups were well balanced, and the imbalanced factors only included age, injury type, medial comminution, blood loss, and cognitive function in single trial. The SUCRA probabilities found that RTSA provided the best effect on the Constant-Murley score (SUCRA: 100.0%), and the disabilities of the arm, shoulder and hand (DASH) score (SUCRA: 99.0%). Moreover, HA (SUCRA: 85.5%) and RTSA (SUCRA: 68.0%) had a relatively better effect on health-related quality of life than the other treatment modalities. Furthermore, conservative therapy (SUCRA: 84.3%) and RTSA (SUCRA: 80.7%) were associated with a lower risk of secondary surgery. Finally, the best effects on the risk of complications are varied, including infection was observed with conservative therapy (SUCRA: 94.2%); avascular necrosis was observed in HA (SUCRA: 78.1%), nonunion was observed in RTSA (SUCRA: 69.6%), and osteoarthritis was observed in HA (SUCRA: 93.9%). CONCLUSIONS: This study found that RTSA was associated with better functional outcomes, while the comparative outcomes of secondary surgery and complications varied. Optimal treatment for PHF should consider patient-specific factors.


Subject(s)
Arthroplasty, Replacement, Shoulder , Hemiarthroplasty , Humeral Fractures , Shoulder Fractures , Adult , Humans , Hemiarthroplasty/adverse effects , Humeral Fractures/surgery , Humerus/surgery , Network Meta-Analysis , Shoulder Fractures/surgery , Shoulder Fractures/etiology , Treatment Outcome
2.
Article in English | MEDLINE | ID: mdl-38754540

ABSTRACT

BACKGROUND: The purpose of this study was to evaluate the relationship between multiple radiographic measures of lateralization and distalization and clinical outcome scores after a reverse total shoulder arthroplasty (RTSA). METHODS: We retrospectively evaluated all RTSAs performed by the senior author between January 1, 2007, and November 1, 2017. We then evaluated the visual analog scale for pain (VAS pain), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) scores and complication and reoperation rates at a minimum of 2-year follow-up. We measured preoperative and postoperative (2-week) radiographs for the lateralization shoulder angle (LSA), the distalization shoulder angle (DSA), lateral humeral offset, and the distance from the glenoid to the lateral aspect of the greater tuberosity. A multivariable analysis was performed to evaluate the effect of the postoperative radiographic measurements on final patient-reported outcomes (ASES scores, SST, and VAS pain). RESULTS: The cohort included 216 shoulders from unique patients who had patient-reported outcome scores available at a minimum of 2-year follow-up (average, 4.0 ± 1.9 years) for a total follow-up rate of 70%. In the multivariable models, more lateralization (LSA) was associated with worse final ASES scores -0.52 (95% confidence interval [CI]: -0.88, -0.17; P = .004), and more distalization (DSA) was associated with better final ASES scores 0.40 (95% CI: 0.11, 0.69; P = .007). More lateralization (LSA) was associated with worse final SST scores -0.06 (95% CI: -0.11, -0.003; P = .039). Finally, greater distalization (DSA) was associated with lower final VAS pain scores, ratio = 0.98 (95% CI: 0.96, 1.00; P = .021). CONCLUSIONS: Greater distalization and less lateralization are associated with better function and less pain after a Grammont-style RTSA. When using a Grammont-style implant, remaining consistent with Grammont's principles of implant placement will afford better final clinical outcomes.

3.
Article in English | MEDLINE | ID: mdl-39389452

ABSTRACT

BACKGROUND: Knowledge regarding differences in the order of frequency of complications after reverse total shoulder arthroplasty (RTSA) between Asian and Western populations is limited. We therefore asked for (1) What is the order of frequency of complications after primary RTSA in the Korean population? (2) What are the rates of complication, reoperation, and revision, and clinical outcomes after index surgery? METHODS: We retrospectively reviewed the 299 consecutive cases who underwent primary RTSA with more than 1 year of follow-up over a period of 12 years. The mean age of the patients was 73.4 years (range, 58-88 years) and the mean follow-up period was 3.8 years (range, 1-11.5 years). Evaluation of the clinical outcomes, complications, and reinterventions was performed at the final follow-up. RESULTS: The mean VAS pain score, UCLA score, ASES score, and SSV improved from 6.7, 10.2, 30.7, and 27.7% before RTSA to 1.4, 26.4, 80.5, 77.2% after RTSA, respectively (P < .001). Overall, 45 complications (15.1%) were observed in 44 patients. The order of frequency of complications was as follows: 16 cases of scapular stress fracture (5.4%), 9 intraoperative or postoperative periprosthetic fracture (3.0%), 6 brachial plexus injury (2.0%), 4 instability (1.3%), 2 glenoid loosening (0.7%), 2 glenoid disassembly (0.7%), 2 periprosthetic joint infection (0.7%), 1 glenoid fixation failure (0.3%), 1 humeral stem fixation failure (0.3%), 1 hematoma (0.3%), and 1 complex regional pain syndrome (0.3%). Reintervention was performed in 15 cases (5.0%) including reoperation (8 cases; 2.7%) and revision surgery (7 cases; 2.3%). CONCLUSION: At a mean follow-up period of 3.8 years, primary RTSA showed satisfactory clinical outcomes with a complication rate of 15.1%, a reoperation rate of 2.7%, and a revision rate of 2.3%. Scapular stress fracture appears to be the most common complication after RTSA in the Korean population.

4.
J Shoulder Elbow Surg ; 33(3): e162-e174, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37473904

ABSTRACT

BACKGROUND: Disabling cuff tear arthropathy (CTA) is commonly managed with reverse shoulder arthroplasty (RSA). However, for patients with CTA having preserved active elevation, cuff tear arthropathy hemiarthroplasty (CTAH) may offer a cost-effective alternative that avoids the complications unique to RSA. We sought to determine the characteristics and outcomes of a series of patients with CTA managed with these procedures. MATERIALS AND METHODS: We retrospectively reviewed 103 patients with CTA treated with shoulder arthroplasty, the type of which was determined by the patient's ability to actively elevate the arm. Outcome measures included the change in the Simple Shoulder Test (SST), the percent maximum improvement in SST (%MPI), and the percentage of patients exceeding the minimal clinically important difference for the change in SST and %MPI. Postoperative x-rays were evaluated to assess the positions of the center of rotation and the greater tuberosity for each implant. RESULTS: Forty-four percent of the 103 patients were managed with CTAH while 56% were managed with RSA. Both arthroplasties resulted in clinically significant improvement. Patients having RSA improved from a mean preoperative SST score of 1.7 (interquartile range [IQR], 0.0-3.0) to a postoperative score of 6.3 (IQR, 2.3-10.0) (P < .01). Patients having CTAH improved from a preoperative SST score of 3.1 (IQR, 1.0-4.0) to a postoperative score of 7.6 (IQR, 5.0-10.) (P < .001). These improvements exceeded the minimal clinically important difference. Instability accounted for most of the RSA complications; however, it did not account for any CTAH complications. The postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure. CONCLUSION: For 103 patients with CTA, clinically significant improvement was achieved with appropriately indicated CTAH and RSA. In view of the lower cost of the CTAH implant, it may provide a cost-effective alternative to RSA for patients with retained active elevation.


Subject(s)
Arthroplasty, Replacement, Shoulder , Hemiarthroplasty , Rotator Cuff Injuries , Rotator Cuff Tear Arthropathy , Shoulder Joint , Humans , Rotator Cuff Tear Arthropathy/surgery , Rotator Cuff Tear Arthropathy/etiology , Arthroplasty, Replacement, Shoulder/adverse effects , Hemiarthroplasty/adverse effects , Shoulder Joint/diagnostic imaging , Shoulder Joint/surgery , Retrospective Studies , Treatment Outcome , Rotator Cuff Injuries/diagnostic imaging , Rotator Cuff Injuries/surgery , Rotator Cuff Injuries/etiology , Range of Motion, Articular
5.
J Shoulder Elbow Surg ; 33(2): e49-e57, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37659703

ABSTRACT

BACKGROUND: The incidence of proximal humerus fractures (PHF) is continuing to rise due to shifts towards a more aged population as well as advancements in surgical treatment options. The purpose of this study is to examine and compare trends in the treatment of PHFs (nonoperative vs. operative; different surgical treatments) across different age groups over the last decade (2010-2020). METHODS: The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried using International Classification of Diseases and Current Procedural Terminology codes to identify all patients presenting with or undergoing surgery for PHF between 2010 and 2020. Treatment trends, demographics, and insurance information were analyzed during the study period. Comparisons were made between operative and nonoperative trends with respect to the number and type of surgeries performed among 3 age groups: ≤49 years, 50-64 years, and ≥65 years. The rate of postoperative complications and reoperations was evaluated and compared among different surgical treatments for patients with a minimum 1-year postoperative follow-up. RESULTS: A total of 92,308 patients with a mean age of 67.8 ± 16.8 years were included. Over the last decade, there was no significant increase in the percentage of PHFs treated with surgery. A total of 15,523 PHFs (16.82%) were treated operatively, and these patients, compared with the nonoperative cohort, were younger (64.9 years vs. 68.4 years, P < .001), more likely to be White (80.2% vs. 74.7%, P < .001), and more likely to have private insurance (41.4% vs. 32.0%, P < .001). For patients ≤49 years old, trends in operative treatment have remained stable with internal fixation (IF) as the most used surgical modality. For patients 50-64 years old, we observed a gradual decline in the use of hemiarthroplasty (HA), with a corresponding increase in the use of reverse total shoulder arthroplasty (rTSA), but IF continued to be the most used operative modality. In patients over 65 years, a steep decline in the use of IF and HA was noted during the first half of the decade along with a significant exponential increase in the use of rTSA, which surpassed the use of IF in 2019. Despite the increase in the use of rTSA, no differences in rate of surgical complications were noted between rTSA and IF (χ2 = 0.245, P = .621) or reoperations (χ2 = 0.112, P = .730). CONCLUSION: Nonsurgical treatment remains the mainstay treatment of PHFs. Although there is no increase in the prevalence of operative treatment in patients ≥50 years in the last decade, there is an exponential increase in the use of rTSA with a corresponding decrease in HA and IF, a trend more substantial in patients ≥65 years compared with patients between 50 and 64 years.


Subject(s)
Arthroplasty, Replacement, Shoulder , Hemiarthroplasty , Humeral Fractures , Shoulder Fractures , Humans , Aged , Middle Aged , Aged, 80 and over , Arthroplasty, Replacement, Shoulder/methods , Hemiarthroplasty/adverse effects , Shoulder Fractures/therapy , Fracture Fixation, Internal , Humeral Fractures/surgery , Treatment Outcome , Humerus/surgery
6.
Article in English | MEDLINE | ID: mdl-38479723

ABSTRACT

BACKGROUND: Anatomic and reverse total shoulder arthroplasty (TSA) are effective treatment options for end-stage glenohumeral osteoarthritis. However, consideration for pre-existing conditions must be taken into account. Factor V Leiden (FVL), the most common inherited thrombophilia, is one such condition that predisposes to a prothrombotic state and may affect perioperative and longer-term outcomes following TSA. METHODS: Adult patients undergoing primary TSA for osteoarthritis indication were identified in the 2010 through October 2021 PearlDiver M157 database. Patients with or without FVL were matched at a 1:4 ratio based on age, sex, and Elixhauser Comorbidity Index. Ninety-day adverse events and 5-year revision rates were assessed and compared with multivariable logistic regression and rank-log tests, respectively. Finally, the relative use and bleeding/clotting outcomes were assessed based on venous thromboembolic (VTE) prophylactic agents used, with categories defined as (1) warfarin, heparin, or direct oral anticoagulant (DOAC) or (2) aspirin/no prescription found. RESULTS: Of 104,258 TSA patients, FVL was identified for 283 (0.27%). Based on matching, 1081 patients without FVL and 272 patients with FVL were selected. Multivariable analyses demonstrated that those with FVL displayed independently greater odds ratios (ORs) of deep vein thrombosis (DVT, OR = 9.50, P < .0001), pulmonary embolism (PE, OR = 10.10, P < .0001), and pneumonia (OR = 2.43, P = .0019). Further, these events contributed to the increased odds of aggregated minor (OR = 1.95, P = .0001), serious (OR = 6.38, P < .0001), and all (OR = 3.51, P < .0001) adverse events. All other individual 90-day adverse events, as well as 5-year revision rates, were not different between the study groups. When compared to matched patients without FVL on the same anticoagulant agents, FVL patients on warfarin, heparin, or DOAC agents demonstrated lesser odds of 90-day DVT and PE (OR = 4.25, P < .0001, and OR = 2.54, P = .0065) than those on aspirin/no prescription found (OR = 7.64 and OR = 21.95, P < .0001 for both). Interestingly, those on VTE prophylactic agents were not at greater odds of bleeding complications (hematoma or transfusion). DISCUSSION AND CONCLUSIONS: TSA patients with FVL present a difficult challenge to shoulder reconstruction surgeons. The current study highlights the strong risk of VTE that was reduced but still significantly elevated for those with stronger classes of VTE chemoprophylaxis. Acknowledging this risk is important for surgical planning and patient counseling, but also noted was the reassurance of similar 5-year revision rates for those with vs. without FVL.

7.
J Shoulder Elbow Surg ; 33(6S): S55-S63, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38428477

ABSTRACT

BACKGROUND: As the indications for reverse total shoulder arthroplasty (RSA) continue to evolve, it has been more commonly utilized for the treatment of glenohumeral osteoarthritis with an intact rotator cuff (GHOA). Given the increased use of RSA for GHOA, it is important to identify factors influential of clinical outcomes. In this study, we sought to identify variables predictive of clinical outcomes following RSA for GHOA. METHODS: Patients undergoing primary RSA for GHOA between 2015 and 2020 were retrospectively identified through a prospectively maintained, single surgeon registry. Eligible patients had complete patient-reported outcome measures and range of motion measurements with a minimum 2-year follow-up. Univariate analysis was utilized to compare characteristics and outcome measures of patients with poor and excellent outcomes, which was defined as postoperative American Shoulder and Elbow Surgeons (ASES) scores in the bottom and top quartiles, respectively. Multivariate linear regression was performed to determine factors independently predictive of postoperative ASES score. RESULTS: A total of 230 patients were included with a mean follow-up of 33.4 months (SD 13.2). The mean age of the study population was 71.9 (SD 6.1). Two hundred twenty-four patients (97.4%) surpassed the minimal clinically important difference and 209 patients (90.1%) achieved substantial clinical benefit for ASES score. Preoperative factors differing between the poor and excellent outcome groups were sex (male: poor 37.9%, excellent 58.6%; P = .041), opioid use (poor 24.1%, excellent 5.2%; P = .009), ASES score (poor 32.9, excellent 41.0; P = .011), and forward elevation (poor 92°, excellent 101°; P = .030). Linear regression demonstrated that Walch B3 glenoids (ß 7.08; P = .010) and higher preoperative ASES scores (ß 0.14; P = .025) were predictors of higher postoperative ASES score, while postoperative complications (ß -18.66; P < .001) and preoperative opioid use (ß -11.88; P < .001) were predictive of lower postoperative ASES scores. CONCLUSION: Over 90% of patients who underwent RSA for GHOA with an intact rotator cuff experienced substantial clinical benefit. An unsurprising handful of factors were associated with postoperative clinical outcomes; higher preoperative ASES scores were slightly associated with higher postoperative ASES, whereas preoperative opioid use and postoperative complications were associated with lower postoperative ASES. Additionally, Walch glenoid type B3 was associated with higher postoperative ASES, indicating that patients with posterior glenoid defects are not predisposed to poor clinical outcomes following RSA. These results serve as a resource to improve preoperative patient counseling and manage postoperative expectations.


Subject(s)
Arthroplasty, Replacement, Shoulder , Osteoarthritis , Shoulder Joint , Humans , Male , Female , Arthroplasty, Replacement, Shoulder/methods , Aged , Osteoarthritis/surgery , Shoulder Joint/surgery , Shoulder Joint/physiopathology , Retrospective Studies , Range of Motion, Articular , Treatment Outcome , Middle Aged , Rotator Cuff/surgery , Patient Reported Outcome Measures
8.
Article in English | MEDLINE | ID: mdl-38852709

ABSTRACT

BACKGROUND: Technological advancements in implant design and surgical technique have focused on diminishing complications and optimizing performance of reverse shoulder arthroplasty (rTSA). Despite this, there remains a paucity of literature correlating prosthetic features and clinical outcomes. This investigation utilized a machine learning approach to evaluate the effect of select implant design features and patient-related factors on surgical complications after rTSA. METHODS: Over a 16-year period (2004-2020), all primary rTSA performed at a single institution for elective and traumatic indications with a minimum follow-up of 2 years were identified. Parameters related to implant design evaluated in this study included inlay vs. onlay humeral bearing design, glenoid lateralization (medialized or lateralized), humeral lateralization (medialized, minimally lateralized, or lateralized), global lateralization (medialized, minimally lateralized, lateralized, highly lateralized, or very highly lateralized), stem to metallic bearing neck shaft angle, and polyethylene neck shaft angle. Machine learning models predicting surgical complications were constructed for each patient and Shapley additive explanation values were calculated to quantify feature importance. RESULTS: A total of 3837 rTSA were identified, of which 472 (12.3%) experienced a surgical complication. Those experiencing a surgical complication were more likely to be current smokers (Odds ratio [OR] = 1.71; P = .003), have prior surgery (OR = 1.60; P < .001), have an underlying diagnosis of sequalae of instability (OR = 4.59; P < .001) or nonunion (OR = 3.09; P < .001), and required longer OR times (98 vs. 86 minutes; P < .001). Notable implant design features at an increased odds for complications included an inlay humeral component (OR = 1.67; P < .001), medialized glenoid (OR = 1.43; P = .001), medialized humerus (OR = 1.48; P = .004), a minimally lateralized global construct (OR = 1.51; P < .001), and glenohumeral constructs consisting of a medialized glenoid and minimally lateralized humerus (OR = 1.59; P < .001), and a lateralized glenoid and medialized humerus (OR = 2.68; P < .001). Based on patient- and implant-specific features, the machine learning model predicted complications after rTSA with an area under the receiver operating characteristic curve of 0.61. CONCLUSIONS: This study demonstrated that patient-specific risk factors had a more substantial effect than implant design configurations on the predictive ability of a machine learning model on surgical complications after rTSA. However, certain implant features appeared to be associated with a higher odd of surgical complications.

9.
Article in English | MEDLINE | ID: mdl-39025356

ABSTRACT

BACKGROUND: Early reverse total shoulder arthroplasty (RTSA) designs demonstrated high glenoid baseplate complication and revision rates. Although contemporary designs have reduced the incidence of glenoid baseplate failures, there are reports of elevated failure risks in RTSA with glenoid bone grafting within the first 2 years. This study aims to evaluate the incidence and etiology of aseptic glenoid baseplate failure with a contemporary central screw baseplate. The null hypothesis is that majority of the baseplate failure occurs within the first 2 years and that use of glenoid bone grafting does not lead to a higher risk of baseplate failure. METHODS: In 2014-2019, a total of 753 consecutive patients who underwent primary RSA using the same inlay press-fit humeral stem and monoblock central screw baseplate were retrospectively reviewed. Fracture and septic arthropathy cases were excluded. All patients underwent preoperative radiographic and computed tomographic evaluation. If there was significant glenoid erosion (Walch A2, B2, B3, C1, C2, E2, E3, and/or E4 variants), patient-specific structural glenoid bone grafting was performed. All patients underwent standardized radiographic follow-up, and failure was strictly defined as any hardware breakage and/or shift in glenoid baseplate position. Failures were defined as "early" if occurring within 2 years and "late" if occurring >2 years after surgery. Comparative analysis was performed to evaluate demographics, glenoid graft use, and graft union rates between the cohorts. RESULTS: There were 23 patients with baseplate failures (23 of 753, 3.0%) at a mean of 23 months. Twenty-two failures (96%) occurred in patients who received structural glenoid bone grafting. Only 1 failure (0.2%) occurred when bone grafting was not indicated (P < .001). The most common failure pattern was associated with the B2 glenoid (16 of 23, 70%). There were 5 early failures (22%) and 18 late failures (78%). There were no differences in any patient demographic characteristics between cohorts. All 5 early failures had graft nonunion, and 4 of them occurred without trauma. In the 18 late failures, 9 (50%) occurred without trauma (P = .135). Seventeen of these patients had glenoid grafting, among which 9 (53%) had graft nonunion. CONCLUSIONS: Contemporary RTSA glenoid baseplate designs have an acceptably low incidence of failure. However, the addition of structural bone graft to correct glenoid wear leads to higher aseptic baseplate failure rate. The majority of these patients suffer failure after the 2-year postoperative mark, highlighting the necessity of longer follow-up. Further analysis is necessary to quantify glenoid characteristics (severity of glenoid erosion, critical size of graft) associated with failure.

10.
J Shoulder Elbow Surg ; 33(10): 2159-2170, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38537767

ABSTRACT

BACKGROUND: Computer simulation has indicated a significant effect of scapulothoracic orientation and posture on range of motion (ROM) after reverse total shoulder arthroplasty (RTSA). We analyzed this putative effect on the clinical and radiologic outcome post-RTSA. METHODS: We retrospectively assessed 2-year follow-up data of RTSA patients treated at our clinic between 2008 and 2019. Patients were categorized into posture types A, B, and C based on an established method using scapular internal rotation on preoperative cross-sectional imaging. We compared differences in clinical ROM, pain, Subjective Shoulder Value, Constant Score, Shoulder Pain and Disability Index (SPADI), quality of life (EuroQol-5 Dimensions-5 Level utility index), and radiologic outcomes between posture types using linear regression analyses. RESULTS: Of 681 included patients, 225 had type A posture, 326 type B, and 130 type C. Baseline group characteristics were comparable, although the type C group had a higher proportion of females (60% [A], 64% [B], 80% [C]) with lower abduction strength (0.7 kg [A], 0.6 kg [B], 0.3 kg [C]) and a slightly higher proportion with a Grammont design RTSA (41% [A], 48% [B], 54% [C]). There were significant adjusted differences in mean (±standard deviation) active flexion (A: 137° ± 21°; B: 136° ± 20°; C: 131° ± 19°) and passive flexion (A: 140° ± 19°; B: 138° ± 19°; C: 134° ± 18°), active (A: 127° ± 26°; B: 125° ± 26°; C: 117° ± 27°) and passive abduction (A: 129° ± 24°; B: 128° ± 25°; C: 121° ± 25°), SPADI (A: 81 ± 18; B: 79 ± 20; C: 73 ± 23), and pain (A: 1.2 ± 1.7; B: 1.6 ± 2.2; C: 1.8 ± 2.4) between posture types at 2 years (P ≤ .035). A higher distalization shoulder angle was associated with better abduction in type C patients (P = .016). Type C patients showed a trend toward a higher complication rate (3.9% vs. 1.1% [A], 3.2% [B]) (P = .067). CONCLUSIONS: Type C posture influences the 2-year clinical outcome of RTSA patients in terms of worse flexion, abduction, SPADI, and pain. Scapulothoracic orientation and posture should be considered during the patient selection process, preoperative planning, and implantation of an RTSA.


Subject(s)
Arthroplasty, Replacement, Shoulder , Posture , Range of Motion, Articular , Scapula , Humans , Female , Male , Aged , Retrospective Studies , Arthroplasty, Replacement, Shoulder/methods , Middle Aged , Posture/physiology , Treatment Outcome , Shoulder Joint/surgery , Shoulder Joint/physiopathology
11.
J Shoulder Elbow Surg ; 33(10): 2320-2332, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38754543

ABSTRACT

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) is a common procedure utilized to address degenerative pathologies of the glenohumeral joint and rotator cuff. Increased reliance on patient-reported outcome measures (PROMs) have placed emphasis on the utilization of the minimum clinically important difference (MCID), substantial clinical benefit (SCB), patient acceptable symptom state (PASS), and maximal outcome improvement (MOI) thresholds to assess the clinical efficacy of RTSA. In this study, we systematically reviewed the MCID, SCB, PASS, and MOI thresholds reported for PROMs following RTSA. METHODS: PubMed, Embase, MEDLINE, Cochrane Library, and Google Scholar were queried for articles from January 1, 2000 to August 31, 2023 reporting MCID, SCB, PASS, or MOI values for PROMs following RTSA. Patient demographic data, study characteristics, MCID/SCB/PASS/MOI thresholds, and threshold calculation methods were extracted. RESULTS: One hundred and forty-one articles were screened with 39 ultimately included, comprising 11,984 total patients that underwent RTSA. 34 (87%) studies reported MCID thresholds, 20 (51%) reported SCB, 5 (13%) reported PASS, and 2 (5%) reported MOI. 25/39 (64%) studies referenced a previous study when reporting MCID, SCB, PASS, or MOI values, 11 (28%) used an anchor-based method to calculate threshold values, 1 (3%) used a distribution-based method, and 2 (5%) used both anchor and distribution methods. There were 19 newly calculated MCID (11), SCB (5), PASS (1), and MOI (2) thresholds. For 5 of the 6 most utilized PROMs (ASES, SST, Constant, UCLA, and SPADI), the range of reported MCID values exceeded 50% of the most common threshold. For 3 of 6, the range of SCB values exceeded 25% of the most common threshold. CONCLUSION: There is substantial variability in the MCID and SCB threshold values reported in the RTSA literature. Standardizing the methodologic calculation and utilization of MCID, SCB, PASS, and MOI thresholds for RTSA may allow for improved assessment of PROMs.


Subject(s)
Arthroplasty, Replacement, Shoulder , Minimal Clinically Important Difference , Patient Reported Outcome Measures , Humans , Arthroplasty, Replacement, Shoulder/methods , Shoulder Joint/surgery
12.
Article in English | MEDLINE | ID: mdl-39121946

ABSTRACT

BACKGROUND: Superior capsular reconstruction (SCR) and reverse total shoulder arthroplasty (rTSA) are widely performed in patients with irreparable rotator cuff tears, including pseudoparalytic shoulder (PPS), and have shown positive clinical outcomes. However, limited studies have compared these 2 in terms of functional recovery in patients with PPS without osteoarthritic change. Thus, this study aimed to compare the clinical outcomes and to clarify the characteristics and differences in temporal changes among patients who underwent either rTSA or SCR using tensor fascia lata for PPS due to irreparable rotator cuff tear without osteoarthritic change (Hamada grade ≤3). METHODS: We enrolled a total of 39 patients who underwent SCR (n = 20) or rTSA (n = 19 cases) with a follow-up period of 2 years. All patients were followed up at 2, 3, 4, 5, 6, 8, 10, 12, and 24 months postoperatively. Preoperative and postoperative range of motion (ROM), American Shoulder and Elbow Surgeons scores, and temporal changes in ROMs were compared between the 2 groups. RESULTS: The SCR group had significantly better ROM than the rTSA group in flexion (146° ± 34° vs. 132° ± 23°, P = .022), abduction (147° ± 36° vs. 130° ± 23°, P = .0092), internal rotation (11 ± 3 Th10 vs. 6 ± 3 L3, P < .001), and American Shoulder and Elbow Surgeons score (84.1 ± 13.8 vs. 80.1 ± 6.1, P = .0096). While the rTSA group achieved 100° in flexion and abduction after 3 months postoperatively, the SCR group took approximately 5 months. However, the SCR group exceeded the rTSA group in flexion and abduction at six months postoperatively. In the SCR group, some patients with irreparable subscapularis tendon tears could not achieve 90° shoulder elevation. Both groups showed significant improvements in shoulder flexion and abduction compared to the preoperative state (P < .001). CONCLUSION: Although SCR requires a longer rehabilitation period, it provides similar outcomes to rTSA after two years for nonosteoarthritic, irreparable cuff tears with pseudoparalysis.

13.
Article in English | MEDLINE | ID: mdl-39168443

ABSTRACT

BACKGROUND: Humeral component retroversion (HcRV) can be customized to match native humeral retroversion (RV) during reverse total shoulder arthroplasty (RTSA). However, assessing postoperative individualized HcRV using computed tomography (CT) scans without an elbow can be challenging. Therefore, we developed a new method to obtain the HcRV and evaluated its reliability. METHODS: A total of 106 patients underwent RTSA using a single implant, in which the humeral component was implanted based on the preoperative humeral RV (Pre_HRV) using a bilateral CT scan of the elbow. Intraoperatively, a retroversion guide with version hole at 10° intervals was used; Pre_HRV was converted to 5° increments and applied for humeral component implantation. The axis of intertubercular sulcus (ITS) was defined as the line perpendicular to the intertubercular line, and the angle between the axis of ITS and the trans-epicondylar axis was defined as the bicipital groove rotation (BGR). ITS orientation was defined as the angle between the axis of ITS and the central axis of the humeral head. Since the BGR does not change, the postoperative implanted HcRV (Post_HcRV)f is calculated as the BGR minus the value of the postoperative ITS orientation. An agreement analysis was performed between Post_HcRV and both the intraoperatively applied humeral RV (I_HRV) and Pre_HRV, as well as between the pre- and postoperative ITS orientations. The humeral component's insertional errors were also evaluated. RESULTS: All radiologic measurements exhibited excellent inter- and intra-observer reliabilities. The reliabilities between Post_HcRV and both I_HRV and Pre_HRV, as well as between pre- and postoperative ITS orientations, showed excellent agreement (intraclass correlation coefficients: 0.953, 0.952, and 0.873, respectively). The humeral component was inserted within 5° in 86.8% of the planned humeral RV cases. CONCLUSIONS: The HcRV measured using the BGR and ITS orientations achieved good accuracy for restoring the planned humeral RV using a retroversion guide with the forearm axis. Therefore, this new radiological measurement method can aid orthopedic surgeons in confirming Post_HcRV on CT scans without an elbow.

14.
Article in English | MEDLINE | ID: mdl-38762150

ABSTRACT

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) can result in varying amounts of humeral medialization or lateralization. The amount of medial or lateral change-in-arm-position can be predicted using 3D computed tomography planning software. It is not clear if the preoperatively predicted change-in-arm-position correlates with the actual radiographically measured change-in-arm-position or if the predicted or actual change-in-arm-position correlates with patient-reported outcomes or complications. METHODS: Patients who received RTSA underwent preoperative 3D computed tomography planning to predict the postoperative medial-to-lateral change-in-arm-position (PCAP). Preoperative and postoperative radiographs were used to calculate the actual medial-to-lateral change-in-arm-position using the measurement of the lateral edge of the greater tuberosity to the lateral edge of the acromion (RCAP-LHO). The Western Ontario Osteoarthritis Score (WOOS), American Shoulder and Elbow Surgeons score (ASES), and Single Assessment Numeric Evaluation (SANE) were recorded at baseline, 1 year, and 2 years. Rates of complications were recorded. RESULTS: A total of 250 patients were eligible for this study including 189 patients reaching the 1-year clinical follow-up point and 144 patients reaching the 2-year clinical follow-up point. One-year and 2-year follow-up rates were 89% and 91%, respectively. The mean PCAP was 3 ± 5 mm and the mean RCAP-LHO was 1 ± 8 mm. There was a moderate correlation between PCAP and RCAP-LHO. There was a weak correlation between increased PCAP lateralization and higher WOOS and ASES at 2 years and an improvement from baseline to 2 years in WOOS. There was a very weak correlation between increased PCAP lateralization and improvement compared with baseline in 1-year SANE and improvement compared with baseline in 2-year SANE. There was a weak correlation between lateralized RCAP-LHO and 2-year postoperative SANE. There was superior 2-year WOOS, ASES, and SANE, and improvement in SANE at 1 year compared with baseline in patients with a lateralized PCAP compared with a medialized or neutral PCAP. There was superior 2-year WOOS, improvement in WOOS from baseline to 2-year follow-up, and 2-year SANE in patients with a lateralized RCAP-LHO compared with a medialized or neutral RCAP-LHO. Overall complication rates were similar between groups although the dislocation rate in shoulders with a lateralized change-in-arm-position was significantly less than that in shoulders with a medial or neutral change-in-arm-position. CONCLUSIONS: PCAP correlated with actual RCAP-LHO. Correlations exist with increased humeral lateralization and improved patient-determined outcomes. Patient-determined outcomes in patients with a lateralized change-in-arm-position were the same as or better than those with a medialized or neutral change-in-arm-position. A lateralized change-in-arm-position did not result in increased overall complications and was protective against postoperative instability.

15.
Article in English | MEDLINE | ID: mdl-39209106

ABSTRACT

BACKGROUND: While both anatomic (ATSA) and reverse total shoulder arthroplasty (RTSA) have been popularized as a means of treating individuals with degenerative shoulder conditions, the indications for each can vary widely amongst providers. While surgeons with differing fellowship training commonly perform these procedures, it is not understood how fellowship training influences choice of implant. METHODS: A national database was queried to identify surgeons performing anatomic and reverse total shoulder arthroplasty. For all surgeons who performed more than 10 cases between 2010-2022, fellowship data was individually collected via online search. For each fellowship group, rates of anatomic and reverse total shoulder arthroplasty were identified using International Classification of Diseases (ICD) procedural codes. Those undergoing revision arthroplasty and those with a history of fracture, infection, or malignancy were excluded. Primary outcome measures included the proportion of primary and revision ATSA and RTSA by fellowship in addition to the rate of RTSA performed for a primary diagnosis of glenohumeral osteoarthritis. RESULTS: A total of 131,974 patients met the inclusion criteria and were retained for this study. RTSA increased from 50.1% of all primary shoulder arthroplasty cases in 2011 to 72.0% in 2022. After adjusting for age and comorbidities, Sports Medicine fellowship-trained (Sports) surgeons opted for primary RTSA over ATSA at a significantly higher rate than Shoulder and Elbow fellowship-trained (Shoulder) surgeons and surgeons who completed another type of fellowship or no fellowship (Other). Sports surgeons also chose RTSA more frequently for the diagnosis of glenohumeral osteoarthritis compared to Shoulder surgeons. Surgeons in the Other cohort were more likely to perform primary ATSA rather than RTSA in comparison to surgeons in the Shoulder and Sports cohorts. Sports surgeons were responsible for the greatest increase in percentage of all shoulder arthroplasty procedures from 2010-2022 (28.4% to 40.4%) while the Other group decreased by a comparable amount (45.9% to 32.4%) over the same period. CONCLUSION: Surgeons who have completed a Sports Medicine fellowship choose RTSA over ATSA at a higher rate than Shoulder and Elbow surgeons, both for all indications and also for a primary diagnosis of glenohumeral osteoarthritis. Those who have no fellowship training or fellowship training outside of Sports Medicine and Shoulder and Elbow surgery have the highest percentage of ATSA in their arthroplasty practice. Revision anatomic and revision reverse total shoulder arthroplasty represents a larger percentage of overall case volume for Shoulder and Elbow surgeons.

16.
J Shoulder Elbow Surg ; 33(9): e492-e506, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38461936

ABSTRACT

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.


Subject(s)
Arthroplasty, Replacement, Shoulder , Minimal Clinically Important Difference , Humans , Arthroplasty, Replacement, Shoulder/methods , Male , Female , Aged , Middle Aged , Sex Factors , Patient Satisfaction , Shoulder Prosthesis , Prospective Studies , Shoulder Joint/surgery , Shoulder Joint/physiopathology , Treatment Outcome , Range of Motion, Articular/physiology , Prosthesis Design
17.
J Shoulder Elbow Surg ; 33(8): 1762-1770, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38242527

ABSTRACT

BACKGROUND: The utilization of short humeral stems in reverse total shoulder arthroplasty has gained attention in recent times. However, concerns regarding the risk of misalignment during implant insertion are associated with their use. METHODS: Eight fresh-frozen cadaveric shoulders were prepared for dissection and biomechanical testing. A bespoke humeral implant was fabricated to facilitate assessment of neutral, varus, and valgus alignments using a single stem, and 10° was established as the maximum permissible angle for misalignments. Shift in humerus position and changes in deltoid length attributable to misalignments relative to the neutral position were evaluated using a Microscribe 3DLx system. The impingement-free range of motion, encompassing abduction, adduction, internal rotation, and external rotation (ER), was gauged using a digital goniometer. The capacity for abduction was evaluated at maximal abduction angles under successive loading on the middle deltoid. A specialized traction system coupled with a force transducer was employed to measure anterior dislocation forces. RESULTS: Relative to the neutral alignment, valgus alignment resulted in a more distal (10.5 ± 2.4 mm) and medial (8.3 ± 2.2 mm) translation of the humeral component, whereas the varus alignment resulted in the humerus shifting more superiorly (11.2 ± 1.3 mm) and laterally (9.9 ± 0.9 mm) at 0° abduction. The valgus alignment exhibited the highest abduction angle than neutral alignment (86.2°, P < .001). Conversely, the varus alignment demonstrated significantly higher adduction (18.4 ± 7.4°, P < .001), internal rotation (68.9 ± 15.0°, P = .014), and ER (45.2 ± 10.5°, P = .002) at 0° abduction compared to the neutral alignments. Anterior dislocation forces were considerably lower (23.8 N) in the varus group compared to the neutral group at 0°ER (P = .047). Additionally, abduction capability was markedly higher in varus alignment at low deltoid loads than the neutral alignment (5N, P = .009; 7.5 N, P = .007). CONCLUSIONS: The varus position enhances rotational range of motion (ROM) but increases instability, while the valgus position does not significantly impact ROM or instability compared to the neutral position.


Subject(s)
Arthroplasty, Replacement, Shoulder , Cadaver , Humerus , Range of Motion, Articular , Shoulder Joint , Shoulder Prosthesis , Humans , Arthroplasty, Replacement, Shoulder/methods , Humerus/surgery , Aged , Shoulder Joint/surgery , Male , Female , Prosthesis Design , Biomechanical Phenomena , Middle Aged , Aged, 80 and over
18.
J Shoulder Elbow Surg ; 33(5): 1150-1156, 2024 May.
Article in English | MEDLINE | ID: mdl-37944744

ABSTRACT

BACKGROUND: Acromion and scapular spine fractures (ASFs) following reverse total shoulder arthroplasty (RSA) have been reported at a rate of 3.9%. The location of the fracture has been shown to be an important factor in determining the outcomes of nonoperative treatment, with medial fractures having worse outcomes than lateral fractures. As the debate between operative and nonoperative treatment continues, a more precise understanding of the location of the fracture is necessary for effective management. The purpose of this study was to use 3-dimensional computed tomography (CT) reconstruction to characterize the exact location of ASFs after RSA. METHODS: A retrospective review of 2 separate institutional shoulder and elbow repositories was performed. Patients with post-RSA ASFs documented by post-fracture CT scans were included. The query identified 48 patients who sustained postoperative ASFs after RSA between July 2008 and September 2021. CT scans of patients with ASFs were segmented using Mimics software. Eight patients were excluded because of poor image quality. Each bone model was manipulated using 3-Matic Medical software to align the individual scapula with an idealized bone model to create a view of scapular fracture locations on a normalized bone model. This model was used to classify the fractures using the modified Levy classification. RESULTS: The study cohort consisted of 40 patients with a diagnosis of postoperative ASF after RSA. The median age at the time of surgery was 76 years (interquartile range, 73-79 years). The cohort comprised 32 women (80%) and 8 men (20%), with a median body mass index of 27.8. Only 10 patients (25%) had a previous diagnosis of osteoporosis and 6 (13%) had a diagnosis of inflammatory arthritis; 53% of patients underwent RSA owing to rotator cuff tear arthropathy. The distribution of fracture locations was similar within the cohort. However, lateral fractures were slightly more prevalent. The most common fracture location was the type I zone, with 12 fracture lines (29%). There were 11 fracture lines (26%) in the type IIa zone, 10 (23%) in the type IIb zone, 0 in the type IIc zone, and 9 (21%) in the type III zone. CONCLUSION: ASFs after RSA occur in 4 predictable clusters. No fractures appeared to distinctly cluster in the type IIc zone, which may not represent a true fracture zone. Understanding the distribution of these fractures will help to enable the future design of implants and devices to stabilize the fractures that require fixation.


Subject(s)
Arthroplasty, Replacement, Shoulder , Shoulder Fractures , Shoulder Joint , Male , Humans , Female , Aged , Acromion/diagnostic imaging , Acromion/surgery , Arthroplasty, Replacement, Shoulder/adverse effects , Arthroplasty, Replacement, Shoulder/methods , Treatment Outcome , Scapula/diagnostic imaging , Scapula/surgery , Retrospective Studies , Shoulder Joint/diagnostic imaging , Shoulder Joint/surgery , Shoulder Fractures/diagnostic imaging , Shoulder Fractures/surgery , Shoulder Fractures/etiology
19.
J Shoulder Elbow Surg ; 33(5): e233-e247, 2024 May.
Article in English | MEDLINE | ID: mdl-37852429

ABSTRACT

BACKGROUND: Inflammatory arthritis (IA) represents a less common indication for anatomic and reverse total shoulder arthroplasty (TSA) than osteoarthritis (OA). The safety and efficacy of anatomic and reverse TSA in this population has not been as well studied compared to OA. We analyzed the differences in outcomes between IA and OA patients undergoing TSA. METHODS: Patients who underwent primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) from 2016-2020 were identified in the Premier Healthcare Database. Inflammatory arthritis (IA) patients were identified using International Classification of Diseases, Tenth Revision, diagnosis codes and compared to osteoarthritis controls. Patients were matched in a 1:8 fashion by age (±3 years), sex, race, and presence of pertinent comorbidities. Patient demographics, hospital factors, and patient comorbidities were compared. Multivariate regression was performed following matching to account for any residual confounding and 90-day complications were compared between the 2 cohorts. Descriptive statistics and regression analysis were employed with significance set at P < .05. RESULTS: Prior to matching, 5685 IA cases and 93,539 OA controls were identified. Patients with IA were more likely to be female, have prolonged length of stay and increased total costs (P < .0001). After matching and multivariate analysis, 4082 IA cases and 32,656 controls remained. IA patients were at increased risk of deep wound infection (OR 3.14, 95% CI 1.38-7.16, P = .006), implant loosening (OR 4.11, 95% CI 1.17-14.40, P = .027), and mechanical complications (OR 6.34, 95% CI 1.05-38.20, P = .044), as well as a decreased risk of postoperative stiffness (OR 0.36, 95% CI 0.16-0.83, P = .002). Medically, IA patients were at increased risk of PE (OR 2.97, 95% CI 1.52-5.77, P = .001) and acute blood loss anemia (OR 1.27, 95% CI 1.12-1.44, P < .0001). DISCUSSION AND CONCLUSION: Inflammatory arthritis represents a distinctly morbid risk profile compared to osteoarthritis patients with multiple increased surgical and postoperative medical complications in patients undergoing aTSA and rTSA. Surgeons should consider these potential complications and employ a multidisciplinary approach in preoperative risk stratification of IA undergoing shoulder replacement.


Subject(s)
Arthroplasty, Replacement, Shoulder , Arthroplasty, Replacement , Osteoarthritis , Shoulder Joint , Humans , Female , Male , Arthroplasty, Replacement, Shoulder/adverse effects , Arthroplasty, Replacement/adverse effects , Postoperative Complications/etiology , Osteoarthritis/complications , Cohort Studies , Retrospective Studies , Treatment Outcome , Shoulder Joint/surgery
20.
J Shoulder Elbow Surg ; 33(3): 583-592, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37778657

ABSTRACT

BACKGROUND: Preoperative teres minor insufficiency has been identified as a risk factor for poor restoration of external rotation (ER) after reverse total shoulder arthroplasty (RTSA). However, there has been little investigation regarding muscle activation patterns generating ER. This prospective study sought to determine the timing and activation levels of the shoulder girdle musculature during ER in well-functioning RTSAs with an intact teres minor using a lateralized design. METHODS: Patients who underwent RTSA ≥1 year previously with functional ER, an American Shoulder and Elbow Surgeons (ASES) score >70, superior rotator cuff deficiency, and an intact teres minor were identified. Electrophysiological and kinematic analyses were performed during ER in the modified neutral position (arm at side with 90° of elbow flexion) and in abduction (AB) (shoulder abducted 90° with 90° of elbow flexion). Dynamometer-recorded torque and position were pattern matched to electromyography during ER. The root-mean-square and integrated electromyography (in microvolts × milliseconds with standard deviation [SD]), as well as median frequency (MF) (in hertz with SD), were calculated to determine muscle recruitment. Pair-wise t test analysis compared muscle activation (P < .05 indicated significance). RESULTS: After an a priori power analysis, 16 patients were recruited. The average ASES score, visual analog scale pain score, and ASES subscore for ER in AB ("comb hair") were 87.7, 0.5, and 2.75 of 3, respectively. In AB, muscle activation began with the upper trapezius, middle trapezius, and latissimus dorsi, followed by the anterior deltoid activating to neutral. With ER beyond neutral, the teres major (9.6 µV × ms; SD, 9.2 µV × ms) initiated ER, followed by the teres minor (14.1 µV × ms; SD, 18.2 µV × ms) and posterior deltoid (11.1 µV × ms; SD, 9.3 µV × ms). MF analysis indicated equal contributions of the teres major (1.1 Hz; SD, 0.5 Hz), teres minor (1.2 Hz; SD, 0.4 Hz), and posterior deltoid (1.1 Hz; SD, 0.4 Hz) in ER beyond neutral. In the modified neutral position, the upper trapezius and middle trapezius were not recruited to the same level as in AB. For ER beyond neutral, the teres major (9.5 µV × ms [SD, 9 µV × ms]; MF, 1.1 Hz [SD, 0.5 Hz]), teres minor (11.4 µV × ms [SD, 15.1 µV × ms]; MF, 1.1 Hz [SD, 0.5 Hz]), and posterior deltoid (8.5 µV × ms [SD, 8 µV × ms]; MF, 1.2 Hz [SD, 0.3 Hz]) were activated in similar sequence and intensity as AB. No differences in muscle activation duration or intensity were noted among the teres major, teres minor, and posterior deltoid (P > .05). CONCLUSION: Active ER after RTSA is complex and is not governed by a single muscle-tendon unit. This study establishes a sequence, duration, and intensity of muscle activation for ER in well-functioning RTSAs. In both tested positions, the teres major, teres minor, and posterior deltoid function equally and sequentially to power ER.


Subject(s)
Arthroplasty, Replacement, Shoulder , Shoulder Joint , Humans , Rotator Cuff/surgery , Prospective Studies , Shoulder/surgery , Range of Motion, Articular/physiology
SELECTION OF CITATIONS
SEARCH DETAIL