Background Adhesive capsulitis (frozen shoulder) is a prevalent condition characterized by shoulder pain and progressive motion loss. Mitochondrial metabolic dysregulation is an underlying driver of chronic inflammation and fibrosis. This study aimed to characterize mitochondrial metabolic abnormalities in patient capsular tissue and evaluate a therapy using adipose-derived stem cell (ADSC) derived mitochondrial nanovesicles transplantation. Methods Single-cell RNA sequencing was utilized to analyze the expression of nuclear-encoded genes related to mitochondrial metabolism in fibroblast subpopulations from human adhesive capsulitis capsular tissue. ADSC-derived membranes were extruded together with exogenous mitochondria to generate engineered mitochondrial nanovesicles (AD-Mito-NPs). An inflammatory fibroblast model was employed to assess the uptake of AD-Mito-NPs, along with associated transcriptomic and metabolomic changes, and their effects on apoptosis, inflammation, and extracellular matrix (ECM) remodeling. Finally, AD-Mito-NPs were locally injected into a rat model to evaluate joint movement and histopathology. Results AD-Mito-NPs retained intact respiratory function, high fibroblast internalization efficiency, and stable physicochemical properties for up to 7 days. In vitro inflammatory models verified that AD-Mito-NPs reversed IL-1β-triggered mitochondrial injury and strengthened mitochondrial oxidative phosphorylation. Furthermore, AD-Mito-NPs alleviated intracellular reactive oxygen species accumulation and fibroblast apoptosis, mitigated inflammatory responses, and remodeled extracellular matrix homeostasis. In vivo, intra-articular administration of AD-Mito-NPs improved shoulder joint mobility, attenuated capsular thickening and disordered collagen arrangement, and suppressed local inflammation in a rat model of adhesive capsulitis. Conclusion Mitochondrial metabolic imbalance is a factor driving capsular fibrosis in adhesive capsulitis. Engineered mitochondrial transplantation offers therapeutic benefits by enhancing mitochondrial energy production, mitigating oxidative stress and inflammation, and restoring ECM balance. The translational potential of this article This article identifies mitochondrial metabolic dysregulation as a key driver of adhesive capsulitis-related capsular fibrosis and demonstrates that engineered AD-Mito-NPs are a safe platform for clinical translation. These NPs effectively enhance energy metabolism, reduce inflammation, and improve shoulder mobility in models, providing a promising alternative to existing treatments.

BACKGROUND:The clinical impact of coracoid graft resorption after the Latarjet procedure has been controversial and likely underestimated. PURPOSE:To (1) develop and validate a refined classification system-coracoid graft resorption based on degree and location (CRDL); and (2) correlate clinical and radiological outcomes with the CRDL classification system. STUDY DESIGN:Cohort study; Level of evidence, 3. METHODS:Between January 2015 and December 2018, 63 patients who underwent the arthroscopic Latarjet procedure were evaluated with computed tomography imaging preoperatively, immediately postoperatively, and at a minimum 5-year follow-up. According to the resorption location, the coracoid graft resorption was classified as grade 0 (no resorption), grade 1 (resorption on the proximal-medial and/or distal-medial part), grade 2 (resorption on the proximal-lateral part with no resorption on the distal-lateral part), and grade 3 (resorption on the distal-lateral part). Resorption severity was categorized as mild (grades 0 and 1) and severe (grades 2 and 3). The incidence, classification, and location of graft resorption were described. Intrarater and interrater reliability were calculated. Correlations between the classification and clinical and radiological outcomes were analyzed. RESULTS:After a mean follow-up of 85.3 months, coracoid graft resorption was observed in 84.1% of cases: grade 0 in 15.9%, grade 1 in 47.6%, grade 2 in 30.2%, and grade 3 in 6.3%. Mild and severe resorption were found in 63.5% and 36.5% of patients, respectively. Resorption mainly occurred on the proximal-medial part of the graft. Intra- and interrater reliability of the classification system were both almost perfect (κ = 0.865 and 0.822, respectively). Significant differences were found in the postoperative American Shoulder and Elbow Surgeons (ASES) and visual analog scale for pain (VAS) scores among different grades and between mild and severe resorption. Correlation and multivariable regression analyses identified higher-grade graft resorption as a risk factor for worse postoperative ASES and VAS scores. CONCLUSION:CRDL classification is a reliable and clinically relevant classification system for coracoid graft resorption evaluation. Application of the CRDL system reveals that while high-grade resorption is a significant risk factor for postoperative shoulder pain, it has no major impact on shoulder function or stability.

Rotator cuff tears remain one of the most common injuries encountered by shoulder surgeons. Although arthroscopic suture-bridge repair has demonstrated superior biomechanical properties and achieved promising clinical results, tendon retears remain a persistent challenge. To address this issue, we have introduced several refinements to optimize the existing repair techniques. One such refinement is the incorporation of a medial knot in the suture-bridge repair, which can decrease gap formation and enable a watertight repair, thereby improving tendon-bone healing. Another critical modification is the use of a rip-stop configuration in the medial row, which can reduce potential suture cut-out, strengthen the resistance of the suturetendon interface, and lower the risk of type II retear. Therefore, we propose a novel hybrid repair technique that integrates medial knot-tying suture-bridge repair and ripstop configuration into a single construct. Additionally, this new repair technique offers the benefit of reducing the number of suture passages and suture anchors required, thereby streamlining the repair process. In summary, this method represents a viable and effective alternative for the treatment of rotator cuff tears and may contribute to reducing the incidence of postoperative retears.

Persistent inflammation and impaired fibrocartilage regeneration hinder the healing of the tendon-bone interface (TBI) following rotator cuff injury. To address this challenge, we propose a spatiotemporally coordinated therapeutic strategy that combines the temporal control of inflammation with targeted fibrocartilage regeneration. A multifunctional nanomedicine delivery system, designated as CMMKT, was developed using reactive oxygen species (ROS)-responsive polymers to control the release of magnesium ions (Mg2+) and kartogenin (KGN). The delivery system was coated with fibrochondrocyte cell membranes to improve spatial specificity in targeting fibrocartilage cells. CMMKT enhanced the migration and proliferation of bone marrow mesenchymal stem cells (BMSCs) in vitro under inflammatory conditions, inhibited apoptosis, restored osteogenic and chondrogenic differentiation capacities, and increased the proportion of M2 macrophages by scavenging ROS and facilitating sustained drug release. In a rat rotator cuff tear model, CMMKT-driven immunomodulation restored fibrochondrocyte-specific matrix deposition, leading to an increased collagen maturity and biomechanical strength. Transcriptomic and metabolomic analyses indicated the suppression of oxidative stress responses and the activation of anabolic pathways in fibrocartilage. Overall, this spatiotemporal coordination therapeutic concept, CMMKT, is a promising approach for TBI repair that integrates inflammatory microenvironment reprogramming with the targeted enhancement of fibrocartilage regeneration.

PURPOSE:To evaluate the clinical outcomes and radiographic findings associated with the modified arthroscopic Latarjet procedure after a minimum 5-year follow-up. METHODS:Patients with recurrent anterior shoulder instability who underwent a modified arthroscopic Latarjet procedure with anterior capsule reconstruction between March 2015 and December 2017 were systematically followed from January 2023 to June 2024. The minimum follow-up duration was 5 years. Clinical evaluations included the American Shoulder and Elbow Surgeons (ASES), Constant-Murley (CM), and Rowe scores, as well as assessment of range-of-motion (ROM) and rate of return to sports (RTS). X-ray and computed tomography (CT) imaging were used to evaluate graft union, progression of osteoarthritis (OA), and fatty infiltration (FI) of the subscapularis muscle. Statistical analyses included comparisons of pre- and postoperation measures, correlation analyses (Pearson's/Spearman's), and binary logistic regression for OA progression. RESULTS:Of the 64 consecutive patients who underwent modified arthroscopic Latarjet procedure, 44 (mean age at operation, 32.2 ± 8.7 years; range, 19-54 years) were included in the final analysis, with a mean follow-up of 7.1 ± 1.4 years (range, 60-105 months). At final follow-up, no patient experienced recurrent shoulder dislocation or subluxation. Functional scores improved significantly compared with preoperative values (ASES: 90.0 (85.0-94.6) to 99.0 (95.0-100.0), P = .0002; CM:84.1 ± 8.5 to 94.0 (91.0-97.0), P < .0001; ROWE: 40.0 (35.0-45.0) to 91.6 ± 10.6, P < .0001). Twenty-six patients (59.1%) achieved the minimal clinically important difference for the ASES (6.4), 29 patients (65.9%) for the CM (4.6), and all patients (100%) for the Rowe score (4.4). No significant restriction in range of motion was observed (forward elevation: 170° (160.0°-180.0°) to 160.2°± 11.8°, P = .109; external rotation: 60° (60.0°-60.0°) to 54.3°± 13.2°, P = .140; internal rotation: T9 to T8, P = .533). All patients returned to sports, with 61.4% resuming play at or above their preinjury level or higher. One patient required removal of the proximal screw. Coracoid bone union was achieved in 43 cases (97.7%). FI of the subscapularis muscle was observed in 34 cases (77.3%), including grade I in 27 cases (61.4%) and grade II in 7 cases (15.9%). Radiographic evaluation showed OA progressed in 9 cases (20.5%), including progression from grade 0 to I in 7 cases (15.9%) and from grade 0 to grade III in 2 cases (4.5%). Grade I OA did not affect shoulder function. Binary logistic regression analysis revealed that high-grade (grade II) FI of the subscapularis muscle at the final follow-up significantly associated with OA progression (P = .017, OR = 45.014). CONCLUSIONS:The arthroscopic Latarjet procedure with anterior capsular reconstruction showed favorable clinical and radiological outcomes after a minimum 5-year follow-up. Patients showed significant improvements in patient-reported measures, high rates of RTS, and no recurrent dislocation or subluxation. Satisfactory positioning of the coracoid graft and high rates of bone union were achieved. A low rate of severe OA progression was observed. Analysis of the limited number of cases with OA progression in this series suggested that the degree of postoperative FI of the subscapularis muscle may be associated with the extent of OA progression. LEVEL OF EVIDENCE:Level IV, retrospective case series.

Background: Preoperative assessment of fatty degeneration is important for managing rotator cuff tears. The Goutallier classification is semiquantitative and observer dependent. Discrepancies among surgeons can be prominent. A quantitative method may improve accuracy and reliability in evaluating the exact percentage of fatty infiltration (Fat%). Hypothesis/Purpose: This study aimed to investigate the correlation between the new quantitative method and the Goutallier classification in assessing fatty infiltration (FI) of the supraspinatus muscle and to explore the use of this method in predicting retear after rotator cuff repair. It was hypothesized that the new method would significantly correlate with the Goutallier classification and be more sensitive to retear. Study Design: Cohort study (diagnosis); Level of evidence; 3. Methods: This study included 105 patients who underwent arthroscopic rotator cuff repair for large to massive tears. All patients underwent routine preoperative and 1-year postoperative magnetic resonance imaging and were divided into 2 groups according to tendon healing. Preoperative quantitative Fat% of the supraspinatus muscle was evaluated based on the signal intensity (SI) of the T1-weighted sequence. The Fat% was calculated using the following equation: SIsupraspinatus = SIfatx Fat% + SImusclex (1 - Fat%). The correlation between the Fat% and the Goutallier grade was determined. Univariate and multivariate analyses were performed to identify the independent risk factors for retear. Results: The mean preoperative Fat% of the supraspinatus muscle was 23.77 +/- 15.96. A significant correlation was found between the Fat% and the Goutallier grade of the supraspinatus muscle (R = 0.655; P < .001). The overall retear rate was 21.9%; however, functional status significantly improved regardless of cuff healing. Multivariate analysis identified the Fat% (P = .005) and the modified Patte classification (P = .003) as independent risk factors of retear. The receiver operating characteristic curves showed that the cutoff value of Fat% for predicting retear was 33.2%. Fat% >33.2% possessed superior diagnostic accuracy (79.0%), Youden index (0.513), and positive and negative predictive values (51.6% and 90.5%, respectively) compared with the Goutallier grades. Conclusion: Although the quantitative method for assessing Fat% of the supraspinatus muscle significantly correlated with the Goutallier classification, the quantitative method is more clinically relevant to retear. Fat% of the supraspinatus muscle >33.2% possessed higher diagnostic value than the Goutallier grades in predicting retear.

BackgroundGlenoid bone loss is proposed to be an important risk factor for recurrent anterior shoulder instability. The purpose of the present study was to develop an accurate and reproducible method for quantifying a bone loss in patients with anterior shoulder instability.MethodsA total of 66 sets of computed tomography images of the glenoid were acquired and en face view was established. Based on the contour of the inferior half and posteroinferior quadrant of the glenoid, the best-fit circle was drawn using the least-squares method with a comparison of the radii. A bone loss was created via a simulated osteotomy, and a method for estimating the bone loss based on the contour of the posteroinferior quadrant was developed.ResultsThe radii of the best-fit circle were 29.30±1.84 mm and 33.76±2.04 mm based on the inferior half and posteroinferior quadrant of the glenoid, respectively (P<0.01). Bone loss quantification using the contour of the inferior half or posteroinferior quadrant with simulated osteotomy showed a significant difference (P<0.01). For a 25% of glenoid bone loss, the estimated value using the traditional method on the contour of the posteroinferior quadrant was 34%. the A new method for accurate bone loss quantification was developed based on the contour of the posteroinferior quadrant of the glenoid.ConclusionEstimation of the glenoid bone loss based on the rim of the posteroinferior quadrant may overestimate the glenoid bone loss due to the difference in the radius of the curvature of the inferior half and posteroinferior quadrant. A mathematical method was developed to correct this error and may aid in more accurately measuring the glenoid bone loss using the contour of the posteroinferior quadrant in patients with anterior shoulder instability.

Background:Acromioclavicular (AC) dislocations are common shoulder injuries. Coracoid tunnel-free coracoclavicular (CC) sling fixation techniques using either allograft or Tightrope represent viable treatment options. Purpose:To (1) compare the clinical outcomes of 2 different coracoid tunnel-free CC sling fixation techniques (allograft vs Tightrope) in treating patients with acute Rockwood type 3 and 5 AC dislocations for a minimum of 24-month follow-up and to (2) identify risk factors for loss of reduction (LOR). Study Design:Cohort study; Level of evidence, 3. Methods:We compared patients treated for AC dislocations using CC sling fixation with either allograft or Tightrope. Functional outcomes (visual analog scale, American Shoulder and Elbow Surgeons score, Constant score, and return to sport) were recorded at 12- and 24-month follow-ups. CC distance (CCD) and complications were evaluated at 3, 6, and 12 months postoperatively. Univariate and multivariate analyses were performed to identify risk factors for LOR. Results:Of the 50 patients included, 23 were in the allograft group and 27 in the Tightrope group. Both groups demonstrated significant improvements in functional outcome postoperatively, without significant intergroup differences. Although CCD significantly decreased in both groups, CCD in the Tightrope group was significantly smaller at each follow-up. Compared with CCD immediately after surgery, CCD remained stable in the Tightrope group at 3-month follow-up (P = .13), whereas it significantly increased in the allograft group (P = .004.). The allograft group exhibited a significantly higher rate of LOR than the Tightrope group (43% vs 15%; P = .03), heterotopic ossification (48% vs 11%; P = .005), and greater tunnel widening (P < .001). The trapezoid tunnel ratio was identified as an independent risk factor for LOR in the allograft group (odds ratio, 0.033; P = .017). Conclusion:Despite similar functional outcome, CC sling fixation with Tightrope demonstrated superior maintenance of CCD in the early postoperative stage, a significantly lower rate of LOR and heterotopic ossification and less tunnel widening compared with allograft. Malposition of the trapezoid tunnel was an independent risk factor for LOR in the allograft group.

Background: Rotator cuff tears (RCTs) can cause inflammation, muscle atrophy, and irreversible fatty infiltration, resulting in poor clinical outcomes. Effective therapeutic approaches to inhibit fatty infiltration in rotator cuff muscles remain limited.Purpose: To identify pathways associated with fatty infiltration through RNA sequencing and to evaluate the therapeutic potential of the glycogen synthase kinase-3 (GSK-3) inhibitor CHIR99021 based on enrichment of the Akt/GSK-3 pathway identified by RNA sequencing.Study Design: Controlled laboratory study.Methods: Supraspinatus muscle biopsy specimens from 6 patients with chronic full-thickness RCTs were analyzed by RNA sequencing. Fibro-adipogenic progenitors (FAPs) or C2C12 myoblasts were cultured with different doses of CHIR99021 to assess their effects on adipogenic or myogenic differentiation, respectively. RNA sequencing identified cellular pathways in FAPs treated with or without CHIR99021. A mouse RCT model was established by detaching the supraspinatus tendon, followed by treatment with or without CHIR99021 administered intraperitoneally. Muscle atrophy and fatty infiltration were assessed histologically and through gene expression analysis at 1 and 4 weeks after surgery.Results: RNA sequencing analysis identified a marked upregulation of the Akt/GSK-3 signaling pathway specifically in patients' samples and FAPs with minimal fat accumulation. CHIR99021 suppressed adipogenic differentiation in FAPs and promoted myogenic differentiation in C2C12 cells. In the mouse RCT model, CHIR99021-treated mice exhibited reduced Oil Red O staining, a larger cross-sectional area, and less muscle weight loss in the supraspinatus muscle compared with the vehicle-treated mice. Gene expression analysis indicated increased myogenesis and reduced fatty infiltration at 1 and 4 weeks after surgery as well as increased expression levels of IL-6 and IL-15 in the CHIR99021 group compared with the control group at 1 week after surgery.Conclusion: The Akt/GSK-3 pathway was enriched in supraspinatus muscle samples and FAPs with low fat accumulation, highlighting its potential as a therapeutic target. The GSK-3 inhibitor CHIR99021 was shown to alleviate fatty infiltration and muscle atrophy after RCTs in vitro and in vivo in a mouse model.Clinical Relevance: The GSK-3 inhibitor CHIR99021 shows potential for treating muscle degeneration after RCTs.

While biomechanical testing has shown a correlation between decortication and anchor failure load, the effects of partial decortication on the biomechanical properties of all-suture anchors remain unclear. We aimed to evaluate the biomechanical effects of partial decortication on all-suture anchors and conventional suture anchors in Sawbones of varying densities. Suture anchors were tested in nondecorticated, partially decorticated, and completely decorticated Sawbones. Two types of all-suture anchors and one type of conventional anchor were evaluated. Two types of biphasic polyurethane foam were used to mimic normal bone: 0.32 g/cm3 density (20 pounds per cubic foot, pcf 20) and osteoporotic bone: 0.16 g/cm3 density (10 pounds per cubic foot, pcf 10). Cyclic loadings were applied, and peak displacement was recorded. After cyclic loading tests, surviving anchors were subjected to pull-to-failure tests. The number of cycles, peak displacement, ultimate failure loads, and failure modes were determined. First, peak displacement was significantly influenced by bone density and anchor type: normal bone models exhibited lower peak displacement than osteoporotic models, and conventional screw-type anchors consistently demonstrated reduced peak displacement compared to all-suture anchors. In contrast, the extent of bone decortication-whether non-decorticated, partially decorticated, or completely decorticated-showed no significant effect on peak displacement. Second, in osteoporotic bone models (10 pounds per cubic foot), no significant difference in failure load was observed between the partially and non-decorticated groups, but both exhibited significantly higher values than the completely decorticated group.

All-suture anchor (ASA) is an emerging suture anchor used to fix soft tissue to bone. Composed entirely of textile material, ASA has the advantage of a small size and less damage to the bone. The purpose of this study was to analyze the mechanism of the pullout process of ASA from bone tissue and to quantitatively compare the extent of damage to cancellous bone by ASA and conventional suture anchors. First, pullout experiments were conducted on ASA in two different synthetic bone blocks to verify the effect of bone density on ASA performance, and the extraction process of ASA in the bone was simulated. In addition, a model of the proximal humerus was created, and different suture anchors were implanted. The damage to cancellous bone caused by the suture anchors was calculated and compared under the same force of 0-150 N and cyclic force of 0-100 N. The results showed that when the force was 150 N, the volume of plastic strain after implantation of conventional suture anchors was 26% larger than that after ASA implantation. The maximum plastic strain after implantation of conventional suture anchors was 1.5 times greater than that after implantation of ASA. Finally, a comprehensive evaluation method of suture anchor performance based on overall stiffness was proposed. According to this evaluation method, the performance of ASA is superior to that of conventional suture anchors.

Rotator cuff tear is one of the most common upper-extremity pathologies and often requires repair. The pursuit of optimal arthroscopic rotator cuff repair has spurred numerous technical innovations and stitch-pattern refinements. First, the double-pulley construct can increase tendon-bone compression and provide a joint seal. Second, the rip-stop configuration can reduce the possibility of tendon cut-through and improve the biomechanical properties of the fixation. Thus, an alternative method is introduced by incorporating both techniques simultaneously into arthroscopic suture-bridge repair, in which the medial double-pulley construct assumes the function of a rip-stop. This method may improve the biology of tendon healing and reduce the retear rate after rotator cuff repair.

Background: Humeral head replacement (HHR) is now rarely recommended for complex proximal humeral fractures (PHFs) in older patients. However, in relatively young and active patients with unreconstructable complex PHFs, controversy still exists regarding the treatment options of reverse shoulder arthroplasty and HHR. The goal of this study was to compare the survival, functional, and radiographic outcomes of HHR in patients aged <70 years and those aged >= 70 years after a minimum 10 years follow-up.Methods: Eighty-seven out of 135 patients undergoing primary HHR were enrolled and then divided into 2 groups based on age: <70 years and >= 70 years. Clinical and radiographic evaluations were performed with a minimum follow-up of 10 years.Results: There were 64 patients (mean, 54.9 years) in the younger group and 23 patients (mean, 73.5 years) in the older group. The younger and older groups had comparable 10-year implant survivorship (98.4% vs. 91.3%). Patients aged >= 70 years had worse American Shoulder and Elbow Surgeons scores (74.2 vs. 81.0, P = .042) and lower satisfaction rates (12% vs. 64%, P < .001) than younger patients. At the final follow-up, older patients had worse forward flexion (117(degrees) vs. 129(degrees), P = .047) and internal rotation (17 vs. 15, P = .036). More greater tuberosity complications (39% vs. 16%, P = .019), glenoid erosion (100% vs. 59%, P = .077), and humeral head superior migration (80% vs. 31%, P = .037) were also identified in patients aged >= 70 years.Conclusions: Unlike the increased risk for revision and functional deterioration over time after reverse shoulder arthroplasty for PHFs in younger patients, a high implant survival rate with lasting pain relief and stable functional outcomes could be observed in younger patients after HHR during long-term follow-up. Patients aged >= 70 years had worse clinical outcomes, lower patient satisfaction, more greater tuberosity complications, and more glenoid erosion and humeral head superior migration than those aged <70 years. HHR should not be recommended for the treatment of unreconstructable complex acute PHFs in older patient populations.Level of evidence: Level III; Retrospective Cohort Comparison; Prognosis Study (c) 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Background:Fatty infiltration (FI) or atrophy alone has been found to be inaccurate in predicting shoulder function after repair of large-to-massive rotator cuff tears (L/MRCTs), especially when a diverse extent of FI and atrophy presents in multiple rotator cuff muscles. Purpose/Hypothesis:The Posterosuperior Tetralogy Scoring System (PS-Tetra Score), which integrates FI and atrophy, was proposed to predict shoulder function after surgery. It was hypothesized was that a PS-Tetra Score ≥3 would be a risk factor for poor shoulder function after repair of posterosuperior L/MRCTs and would possess greater diagnostic value than using isolated FI or atrophy of the supraspinatus (SSP) or infraspinatus (ISP). Study Design:Case-control study; Level of evidence, 3. Methods:A total of 187 arthroscopic repairs of posterosuperior L/MRCTs were reviewed. Magnetic resonance imaging evaluations were performed of FI and atrophy of the SSP and ISP, teres minor hypertrophy, tendon retraction, and acromiohumeral distance. A postoperative American Shoulder and Elbow Surgeons (ASES) score of 70 was used to subgroup patients according to shoulder function. Univariate and multivariate analyses were performed to determine the risk factors of poor shoulder function (ASES ≤70). The diagnostic values of different indicators for predicting shoulder function were evaluated. Results:In univariate analysis, female sex, higher Goutallier grade of the SSP and ISP, positive SSP tangent sign, and PS-Tetra Score ≥3 was significantly associated with ASES score ≤70, whereas in binary logistic regression analysis, a PS-Tetra Score ≥3 was the only significant risk factor for poor shoulder function. The occurrence rate of poor function in shoulders with a PS-Tetra Score of 0, 1, 2, 3, and 4 was 0% (0/52), 0% (0/52), 19.57% (9/46), 58.06% (18/31), and 83.33% (5/6), respectively. PS-Tetra Score ≥3 possessed higher crude agreement (87.70%), specificity (90.97%), positive predictive value (62.16%), and area under the receiver operating characteristic curve (0.814) than the other 3 indicators, with relatively high negative predictive value (94.00%) and moderate sensitivity (71.88%). Conclusion:PS-Tetra Score ≥3 was a risk factor of poor shoulder function after repair of posterosuperior L/MRCTs and possessed greater diagnostic value than using isolated FI or atrophy of SSP or ISP alone for predicting shoulder function.

Objective:To evaluate the effectiveness of tendon insertion medialized repair in treatment of large-to-massive rotator cuff tears (L/MRCT). Methods:The clinical and imaging data of 46 L/MRCT patients who underwent arthroscopic insertion medialized repair between October 2015 and June 2019 were retrospectively analyzed. There were 26 males and 20 females with an average age of 57.7 years (range, 40-75 years). There were 20 cases of large rotator cuff tears and 26 cases of massive rotator cuff tears. Preoperative imaging evaluation included fatty infiltration (Goutallier grade), tendon retraction (modified Patte grade), supraspinatus tangent sign, acromiohumeral distance (AHD), and postoperative medializaiton length and tendon integrity. The clinical outcome was evaluated by visual analogue scale (VAS) score, American Society for Shoulder and Elbow Surgery (ASES) score, shoulder range of motion (including anteflexion and elevation, lateral external, and internal rotation) and anteflexion and elevation muscle strength before and after operation. The patients were divided into two groups (the intact tendon group and the re-teared group) according to the integrity of the tendon after operation. According to the medializaiton length, the patients were divided into group A (medialization length ≤10 mm) and group B (medialization length >10 mm). The clinical function and imaging indexes of the patients were compared. Results:All patients were followed up 24-56 months, with an average of 31.8 months. At 1 year after operation, MRI showed that the medializaiton length of supraspinatus tendon was 5-15 mm, with an average of 10.26 mm, 33 cases in group A and 13 cases in group B. Eleven cases (23.91%) had re-teared, including 5 cases (45.45%) of Sugaya type Ⅳ and 6 cases (54.55%) of Sugaya type Ⅴ. At last follow-up, the VAS score, ASES score, shoulder anteflexion and elevation range of motion, lateral external rotation range of motion, and anteflexion and elevation muscle strength significantly improved when compared with those before operation ( P<0.05); there was no significant difference in internal rotation range of motion between pre- and post-operation ( P>0.05). The Goutallier grade and modified Patte grade of supraspinatus muscle in the re-teared group were significantly higher than those in the intact tendon group, and the AHD was significantly lower than that in the intact tendon group ( P<0.05). There was no significant difference in other baseline data between the two groups ( P>0.05). Except that the ASES score of the intact tendon group was significantly higher than that of the re-teared group ( P<0.05), there was no significant difference in the other postoperative clinical functional indicators between the two groups ( P>0.05). There was no significant difference in the incidence of re-tear, VAS score, ASES score, range of motion of shoulder joint, and anteflexion and elevation muscle strength between group A and group B ( P>0.05). Conclusion:Tendon insertion medialized repair may be useful in cases with L/MRCT, and shows good postoperative shoulder function. Neither tendon integrity nor medialization length shows apparent correlations with postoperative shoulder function.

Objective:To explore the long-term effectiveness of arthroscopic partial repair in treatment of massive irreparable rotator cuff tears from both the radiological and clinical perspectives. Methods:A retrospective analysis was conducted on the clinical data of 24 patients (25 sides) with massive irreparable rotator cuff tears who met the inclusion criteria between May 2006 and September 2014. Among them, there were 17 males (18 sides) and 7 females (7 sides) with an age range of 43-67 years (mean, 55.0 years). There were 23 cases of unilateral injury and 1 case of bilateral injuries. All patients were treated with the arthroscopic partial repair. The active range of motion of forward elevation and abduction, external rotation, and internal rotation, as well as the muscle strength for forward flexion and external rotation, were recorded before operation, at the first postoperative follow-up, and at last follow-up. The American Association of Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder scoring, and Constant score were used to evaluate shoulder joint function. And the visual analogue scale (VAS) score was used to evaluate shoulder joint pain. MRI examination was performed. The signal-to-noise quotient (SNQ) was measured above the anchor point near the footprint area (m area) and above the glenoid (g area) in the oblique coronal T2 fat suppression sequence. The atrophy of the supraspinatus muscle was evaluated using the tangent sign. The global fatty degeneration index (GFDI) was measured to assess fat infiltration in the supraspinatus muscle, infraspinatus muscle, teres minor muscle, upper and lower parts of the subscapularis muscle. The mean GFDI (GFDI-5) of 5 muscles was calculated. Results:The incisions healed by first intention. All patients were followed up with the first follow-up time of 1.0-1.7 years (mean, 1.3 years) and the last follow-up time of 7-11 years (mean, 8.4 years). At last follow-up, the range of motion and muscle strength of forward elevation and abduction, ASES score, Constant score, UCLA score, and VAS score of the patients significantly improved when compared with those before operation ( P<0.05). Compared with the first follow-up, except for a significant increase in ASES score ( P<0.05), there was no significant difference in the other indicators ( P>0.05). Compared with those before operation, the degree of supraspinatus muscle infiltration worsened at last follow-up ( P<0.05), GFDI-5 increased significantly ( P<0.05), and there was significant difference in the tangent sign ( P<0.05); while there was no significant difference in the infiltration degree of infraspinatus muscle, teres minor muscle, and subscapularis muscle, upper and lower parts of the subscapularis muscle ( P>0.05). Compared with the first follow-up, the SNQm and SNQg decreased significantly at last follow-up ( P<0.05). At the first and last follow-up, there was no correlation between the SNQm and SNQg and the ASES score, Constant score, UCLA score, and VAS score of the shoulder ( P>0.05). Conclusion:Arthroscopic partial repair is effective in treating massive irreparable rotator cuff tear and significantly improves long-term shoulder joint function. For patients with severe preoperative fat infiltration involving a large number of tendons and poor quality of repairable tendons, it is suggested to consider other treatment methods.

BACKGROUND:Proximal humeral fractures (PHFs) often occur in elderly individuals who experience low-energy falls. Open reduction and internal fixation (ORIF) of the proximal humerus is typically performed in young, active patients because of their good bone quality and high functional demands. Although good short-term results have been reported after ORIF in young patients, few studies have specifically evaluated long-term outcomes. QUESTIONS/PURPOSES:(1) What are the long-term clinical outcomes scores and (2) radiologic outcomes of nonosteoporotic three-part and four-part PHFs treated with locking plates? (3) What complications occurred after treatment, and what factors are associated with poor postoperative functional outcomes scores and avascular necrosis (AVN) of the humeral head after ORIF? METHODS:Between June 2005 and December 2012, we surgically treated 774 patients for displaced two-, three-, and four-part PHFs. Approximately 75% (581 of 774) underwent ORIF, 10% (77 of 774) underwent hemiarthroplasty, 7% (54 of 774) underwent intramedullary nailing, 5% (39 of 774) underwent reverse shoulder arthroplasty, and the remaining 3% (23 of 774) underwent other surgical treatments. We considered those who had ORIF as potentially eligible. Based on that criterion, 75% (581) were eligible. However, only patients with nonosteoporotic three- and four-part PHFs (cortical thickness of the proximal humeral diaphysis greater than 6 mm on a preoperative AP radiograph of the affected shoulder) and a minimum of 10 years of follow-up were included. Sixty-four percent (498 of 774) of the patients were excluded because of simple or osteoporotic fractures, 1% (7 of 774) were excluded because of ipsilateral limb multiple fractures, 0.3% (2 of 774) were excluded because of pathologic PHFs, and another 2% (13 of 774) were lost before the minimum study follow-up of 10 years, leaving 8% (61 of 774) for analysis here. The mean age at surgery was 45 ± 12 years, with a mean follow-up of 13 years. Fifty-seven percent (35 of 61) of the patients were men. Patient-reported outcomes were evaluated using the University of California Loas Angeles (UCLA) score (range 0 to 35; higher scores represent better shoulder function) and Constant score (range 0 to 100; higher scores represent better shoulder function) at least 10 years postoperatively. Postoperative radiographs were reviewed to assess the cortical bone thickness of the proximal humerus, neck-shaft angle, head-to-tuberosity distance, and radiologically confirmable complications. Logistic regression analysis was performed to evaluate factors associated with poor postoperative functional scores (UCLA score ≤ 27 or Constant score ≤ 70) and AVN of the humeral head; the association between AVN and postoperative functional outcomes was also assessed. RESULTS:At the most-recent follow-up, these patients had a mean UCLA score of 31 ± 3 and a Constant score of 88 ± 10. The mean neck-shaft angle was 133° ± 10°, and 23% (14 of 61) of patients experienced AVN of the humeral head during follow-up. Twenty-nine complications in 30% (18 of 61) of patients were reported. After controlling for potentially confounding variables such as age and gender, we found that the presence of greater tuberosity malposition (odds ratio 18 [95% confidence interval 2 to 167]; p = 0.01) and immediate postoperative neck-shaft angle less than 130° (OR 19 [95% CI 3 to 127]; p = 0.002) were associated with poor postoperative functional scores. Four-part PHFs (OR 13 [95% CI 2 to 82]; p = 0.008) and metaphyseal extension less than 8 mm (OR 7 [95% CI 1 to 35]; p = 0.03) were associated with AVN of the humeral head. For patients who met the criteria for anatomic reduction (achievement of all of the following three criteria: neck-shaft angle ≥ 130°, head-shaft displacement < 5 mm, and head-to-tuberosity distance greater than or equal to 3 mm and less than or equal to 20 mm), there were no differences in postoperative functional scores between patients with AVN and those without. CONCLUSION:ORIF of nonosteoporotic proximal humeral fractures with locking plates led to favorable functional and radiologic outcomes at a minimum of 10 years of follow-up. When encountering complex PHFs in patients with good bone quality, every effort must be made to achieve an anatomic reduction of the fracture as far as possible, which may not reduce the risk of AVN (this occurred in nearly one-fourth of patients). However, good outcomes can usually be expected, even in patients with AVN. Because this was a retrospective study with a high risk of bias owing to sparse data, the factors associated with poor postoperative functional outcomes must be further investigated in large prospective studies. LEVEL OF EVIDENCE:Level III, therapeutic study.

Shoulder hemiarthroplasty (HA) is now rarely indicated for complex proximal humeral fractures due to its unpredictable characteristic of the greater tuberosity (GT) healing. Despite the increasing popularity of reverse shoulder arthroplasty (RSA) in fracture treatment, there are still concerns about failure revision and its application in young populations. The complete negation of HA for fracture treatment is still under debate. Eighty-seven out of 135 patients with acute proximal humeral fractures treated with HA were enrolled. Clinical and radiographic evaluations were performed. With a mean follow-up time of 14.7 years, the 10-year prosthetic survival rate was 96.6%. The mean ASES score and Constant score were 79.3 and 81.3, respectively, the mean VAS was 1.1, the average forward flexion was 125.9°, external rotation was 37.2°, and internal rotation was at the L4 level. Nineteen patients (21.8%) displayed GT complications and showed significantly worse outcomes. Glenoid erosion was observed in 64.9% of the patients and resulted in inferior outcomes. The patients who showed good postoperative two year functional outcomes and good acromiohumeral distances usually maintained their results without deterioration over time. With strict patient selection, a proper surgical technique and closely supervised postoperative rehabilitation, HA could achieve a 96.6% ten year survival rate and good pain relief at an average follow-up of 15 years. Although rarely indicated, HA should have a role in the treatment of acute complex proximal humeral fractures in relatively young and active patients with good GT bone and intact cuff.

Objective To explore the clinical results after mini-open reduction and fixation using a modified coracoid tunnel-free coracoclavicular sling technique of patients with acromioclavicular separation.Methods Twenty-two patients（16 males and 6 females） with acromioclavicular separation（9 left and 13 right shoulders affected） and treated in Beijing Huairou Hospital between January 2019 and June 2021 were selected. They ranged in age from 28 to 74 years,with an average age of（41.7 ±2.5） years. Their surgery was performed 2 to 6 days after the injury,with an average gap of 4.2 ±1.7 days. According to the preoperative X-ray and three-dimensional CT,13,2 and 7 patients suffered from Rockwood type Ⅲ, Ⅳ and Ⅴ shoulder injury, respectively. All patients underwent the mini-open reduction and fixation with modified coracoid tunnel-free coracoclavicular sling technique,and followed up no less than 6 months. Before the operation and during the follow-up,all patients were evaluated the pain and function of shoulders using the visual analog score（VAS score）,Constant score,American Shoulder and Elbow Surgeons score（ASES score）,as well as the range of motion. Xrays of the shoulder joint were taken to measure the coracoclavicular space and assess the reduction of the acromioclavicular joint,right before the surgery,the second day after the surgery and at the last follow-up.Results All patients were successfully followed up,with an average follow-up of 9.0 ± 2.8months（6.2～12.1 months）. During the last follow-up,a significant improvement was observed in the average VAS,Constant and ASES scores[（1.0 ± 0.5）,（87.0 ± 2.8） and（78.0 ± 1.4）] compared with those before the surgery[（6.0 ± 0.8）,（38.2 ± 4.1） and（38.6 ± 2.6）]（P＜0.001 for all）. Moreover,during the last follow-up, the anteflexion angle of the shoulder increased significantly to 139.0° ±0.8° from the postoperative 80.0° ± 7.5°,while the average abduction angle increased significantly to156.8° ± 3.6° from the postoperative 81.0° ± 5.0°. Meanwhile,the average coracoclavicular distance decreased significantly from 17.5 ± 3.5 mm before the surgery to 6.4 ± 2.5 mm the 2 nd day after the surgery（P＜0.001）,and fluctuated less than 2 mm till the last follow-up. What’s more,no fracture of the coracoid process or clavicle was detected during the last follow-up.Conclusion Mini-open reduction and fixation using a modified coracoid tunnel-free coracoclavicular sling technique is reliable in treating patients with acute acromioclavicular separation.

目的:比较CT与MRI评估肩袖脂肪浸润程度的一致性以及不同层面评估肩袖脂肪浸润程度的一致性.方法:选取24例肩袖撕裂患者的CT与MRI,采用Goutallier分型评估肩袖脂肪浸润情况.三位骨科医师分别从三个层面进行评估.评估层面包括:斜矢状位标准层面以及标准层面偏外1个层面、偏外2个层面.采用加权κ比较不同检查的一致性.结果:CT评估脂肪浸润的观察者内一致性为0.45～0.74,观察者间一致性为0.50～0.65.MRI评估脂肪浸润的观察者内一致性为0.81～0.91,观察者间一致性为0.67～0.71.MRI与CT的一致性为0.32～0.34.标准层面与标准层面向外一个层面的一致性为0.73～0.77,标准层面与标准层面向外两个层面的一致性为0.45～0.53.结论:MRI评估肩袖脂肪浸润的一致性优于CT,MRI与CT评估结果相关性较差.应尽可能选择标准层面评估肩袖脂肪浸润,如选取层面过于偏外,会与真实情况产生显著差异.