Fibroblast growth factor 8b (FGF-8b) enhances myogenesis and inhibits adipogenesis in rotator cuff muscle cell populations in vitro.

Fatty expansion is one of the features of muscle degeneration due to muscle injuries, and its presence interferes with muscle regeneration. Specifically, poor clinical outcomes have been linked to fatty expansion in rotator cuff tears and repairs. Our group recently found that fibroblast growth factor 8b (FGF-8b) inhibits adipogenic differentiation and promotes myofiber formation of mesenchymal stem cells in vitro. This led us to hypothesize that FGF-8b could similarly control the fate of muscle-specific cell populations derived from rotator cuff muscle involved in muscle repair following rotator cuff injury. In this study, we isolate fibro-adipogenic progenitor cells (FAPs) and satellite stem cells (SCs) from rat rotator cuff muscle tissue and analyzed the effects of FGF-8b supplementation. Utilizing a cell plating protocol, we successfully isolate FAPs-rich fibroblasts (FIBs) and SCs-rich muscle progenitor cells (MPCs). Subsequently, we demonstrate that FIB adipogenic differentiation can be inhibited by FGF-8b, while MPC myogenic differentiation can be enhanced by FGF-8b. We further demonstrate that phosphorylated ERK due to FGF-8b leads to the inhibition of adipogenesis in FIBs and SCs maintenance and myofiber formation in MPCs. Together, these findings demonstrate the powerful potential of FGF-8b for rotator cuff repair by altering the fate of muscle undergoing degeneration.

Effects of propofol versus sevoflurane on surgical field visibility during arthroscopic rotator cuff repair: a randomized trial.

BACKGROUND: During arthroscopic rotator cuff repair (ARCR), clear surgical field visibility (SFV) is the basis of successful surgery, but the choice of anesthesia maintenance drugs may have different effects on SFV. In this study, we aimed to compare the effects of propofol- and sevoflurane-based general anesthesia on SFV in patients undergoing ARCR. METHODS: Patients (n = 130) undergoing elective ARCR in the lateral decubitus position were randomized into either the propofol group or sevoflurane group (65 per group). The duration of surgery and increased pressure irrigation (IPI), Boezaart score, rocuronium consumption and usage of remifentanil were recorded. The time of both spontaneous respiration recovery and extubation and the incidences of postoperative nausea and vomiting and agitation were also recorded. RESULTS: The Boezaart score, duration of IPI and ratio of the duration of IPI to the duration of surgery (IPI/S ratio) were similar between the groups (P > 0.05). Rocuronium consumption, number of patients requiring remifentanil infusion and total remifentanil consumption were significantly lower in the sevoflurane group (P < 0.05). The spontaneous respiration recovery time was significantly longer in the propofol group (P < 0.05), but there were no differences in the extubation time between the groups(P > 0.05). CONCLUSIONS: Compared with propofol, sevoflurane provides equally clear SFV while improving the convenience of anesthesia maintenance in ARCR patients with interscalene plexus (ISB) combined with general anesthesia. TRIAL REGISTRATION: This single-center, prospective, RCT was retrospective registered at Chinese Clinical Trial Registry with the registration number ChiCTR2300072110 (02/06/2023).

More severe supraspinatus tendon degeneration on the contralateral shoulders in patients treated for symptomatic rotator cuff tears compared to healthy controls: a quantitative MRI-based study.

BACKGROUND: Patients treated for symptomatic rotator cuff tear (RCT) on one shoulder seem to have a higher prevalence of RCT on the contralateral shoulder. PURPOSE: To compare the supraspinatus (SSP) tendon and RC muscle properties on the contralateral shoulder in patients after repair surgery to those healthy individuals using quantitative magnetic resonance imaging (MRI). MATERIAL AND METHODS: A total of 23 patients treated for RCT (group A) and 23 healthy controls (group B) were recruited. Constant score, visual analog scale score (VAS), and MRI examinations were conducted. The SSP tendon structural status was graded based on the Zlatkin classification and quantified on ultrashort echo time (UTE)-T2* mapping images. Fatty degeneration of RC muscles was classified according to the Goutallier classification and quantified on T2 mapping. RESULTS: The Constant and VAS scores were comparable between groups A and B (all P >0.05). No significant differences were observed in tendon structural status between the two groups (P >0.05). However, significant differences were established in UTE-T2* values of the SSP tendon on the distal subregion between groups A and B (16.4 ± 2.4 ms vs. 14.8 ± 1.2 ms; P = 0.01). Regarding muscle degeneration, no significant differences were displayed in T2 values and Goutallier classification of RC muscles (all P >0.05). CONCLUSION: Patients with a treated RCT demonstrated inferior SSP tendon in the distal subregion on the contralateral shoulders one year postoperatively compared to that of healthy controls based on quantitative MRI data.

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

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

Arthroscopic cuff repair: footprint remnant preserving versus debriding rotator cuff repair of transtendinous rotator cuff tears with remnant cuff.

BACKGROUND: In transtendinous full thickness rotator cuff tears (FTRCT) with remnant cuff, conventionally, cuff remnant of the greater tuberosity (GT) is debrided for better tendon to bone healing. However, larger cuff defect caused overtension on the repaired tendon. The purpose of this study was to compare the clinical outcomes and tendon integrity between remnant preserving and remnant debriding cuff repairs in the transtendinous FTRCT with remnant cuff. METHODS: From March, 2012 to October, 2017, a total of 127 patients who had the transtendinous FTRCT with remnant cuff were enrolled in this study. Rotator cuff tears were repaired arthroscopically, with patients divided into two groups: group I (n = 63), where rotator cuff remnants were preserved during the repair, and group II (n = 64), where the remnants were debrided during the repair. Clinical outcomes were assessed at the last follow-up (minimum 2 years) using the UCLA score, ASES score, SST score, Constant Shoulder score, and range of motion (ROM). The analysis of structural integrity and tendon quality was performed using the Sugaya classification on postoperative MRI scans at 8 months after surgery. RESULTS: At the final follow-up, UCLA, ASES, SST, and CS scores significantly improved from preoperative values to postoperative (all p < 0.05): UCLA (I: 19.6 ± 6.0 to 31.7 ± 3.2, II: 18.0 ± 5.7 to 31.5 ± 3.2), ASES (I: 54.3 ± 10.7 to 86.5 ± 12.5, II: 18.0 ± 5.7 to 85.8 ± 12.4), SST (I: 5.6 ± 2.8 to 10.2 ± 2.0, II: 5.0 ± 2.9 to 10.1 ± 2.5), CS (I: 74.0 ± 17.2 to 87.8 ± 9.7, II: 62.0 ± 19.2 to 88.3 ± 6.2). However, there were no significant differences between the two groups (p > 0.05). Also, remnant preserving cuff repair yielded significantly better tendon quality on postoperative MRI (p < 0.05). The incidence of re-tear (Sugaya's Type IV and V) was not significantly different between the two groups (I:17% vs. II:19%; p = 0.053). CONCLUSIONS: Remnant preserving rotator cuff repairs, which facilitate tendon-to-tendon healing, are superior in terms of tendon quality and are the preferred option for transtendinous FTRCT. TRIAL REGISTRATION: Retrospectively registered.

Skilled reaching test for shoulder function assessment in a rat model of rotator cuff tear: a pilot study.

BACKGROUND: Functional assessments are crucial to evaluate treatment outcomes in clinical and animal studies on rotator cuff injuries. While gait analysis is commonly used to assess animal models of rotator cuff tears, it is less relevant for human patients as the human shoulder is typically assessed in a non-weight-bearing condition. The present study introduces the skilled reaching test as a shoulder functional assessment tool for rats, which allows for evaluation without weight bearing. METHODS: In the control group, 8 male Sprague-Dawley rats received rotator cuff tear surgery without repair. In the rotator cuff repair group, 20 rats received rotator cuff repair at 4 weeks post rotator cuff tear. For the skilled reaching test, rats were trained to extend their forelimbs to fetch food pellets, and the number of trials, number of attempts and the success rate were recorded. The gait analysis and skilled reaching test were performed at baseline, 4 weeks post-tear, 1, 2, 4, and 8 weeks post-repair. The repeated measures analysis of variance was used to evaluate the effects of time on the shoulder function. The significance level was set at 0.05. RESULTS: The skilled reaching test required 216 h to conduct, while the gait analysis took 44 h. In the rotator cuff repair group, gait performance significantly deteriorated at 1 week post-repair and restored to 4 weeks post-tear levels at 4 weeks post-repair. Regarding the skilled reaching test, the number of attempts, number of trials and the success rate decreased at 1 week post-repair. Subsequently, there was a brief rebound in performance observed at 2 weeks post-repair, followed by a continued decline in the number of attempts and trials. By 8 weeks post-repair, only the success rate had restored to levels similar to those observed at 4 weeks post-tear. CONCLUSION: The skilled reaching test can detect functional deficiencies following rotator cuff tear and repair, while it requires high time and labour costs.

Comparison of the clinical efficacy and prognosis of the two techniques for treating partial articular-sided supraspinatus tendon tears under arthroscopy.

BACKGROUND: At present, shoulder arthroscopy is usually used for treatment of rotator cuff injuries. There is still debate over the precise technique of using shoulder arthroscopy to treat partial articular-sided supraspinatus tendon injuries. OBJECTIVE: To compare the clinical efficacy of the arthroscopic transtendon repair method and the arthroscopic full-thickness repair method in the treatment of patients with Ellman III partial articular-sided supraspinatus tendon tears and to analyze the influencing factors of postoperative efficacy. STUDY DESIGN: Cohort study; level of evidence,4. METHODS: A total of 84 partial-thickness rotator cuff tear (PTRCT) patients with Ellman III injuries who underwent surgical treatment in our hospital between January 2017 and January 2020 were selected and divided into the arthroscopic trans-tenon repair group (32 cases) and the arthroscopic full-thickness repair group (52 cases). Shoulder joint pain and functional status were assessed by the Constant score, ASES score and VAS score; shoulder mobility was assessed by measuring shoulder ROM. The clinical outcomes of the two groups of patients were compared, and the factors affecting the postoperative efficacy of the patients were investigated. RESULTS: All patients were followed up for at least 2 years. The Constant score, ASES score, and VAS score of the two groups of patients were all improved compared with those before surgery, and the differences were statistically significant (P < 0.05). There were no significant differences in the Constant score, ASES score, or VAS score between the two groups (P > 0.05). The results of binary logistic regression analysis showed that the preoperative ASES score and whether biceps tenotomy was performed were independent risk factors for satisfactory postoperative efficacy (P < 0.05). CONCLUSION: For patients with Ellman III partial articular-sided supraspinatus tendon tears, the arthroscopic transtendon repair method and the arthroscopic full-thickness repair method can both significantly improve the shoulder pain and function of the patient, but there is no significant difference between the efficacy of the two surgical methods. The preoperative ASES score and whether biceps tenotomy was performed were independent risk factors for satisfactory postoperative efficacy in PTRCT patients with Ellman III injury.

Clinical effect of modified anterolateral acromioarthroplasty during arthroscopic rotator cuff repair.

BACKGROUND: This study aimed to compare the clinical effect of modified anterolateral and traditional acromioplasty in arthroscopic rotator cuff repair. METHODS: The clinical data of 92 patients with total rotator cuff tears admitted to the Department of Joint Surgery of Jinhua Central Hospital from January 2016 to December 2019 were retrospectively analyzed. Among them, 42 patients underwent traditional acromioplasty during arthroscopic rotator cuff repair, and 50 underwent modified anterolateral acromioplasty. Patients were evaluated for preoperative and postoperative shoulder function, pain and critical shoulder angle, and incidence of rotator cuff re-tear at 12 months postoperatively. RESULTS: The preoperative general data of patients in the classic and modified anterolateral acromioplasty groups did not differ significantly (P > 0.05) and were comparable. The UCLA, ASES, and Constant shoulder joint scores were significantly improved in both groups. The VAS score was significantly decreased at 12 months postoperative than preoperative, with a statistically significant difference (P ≤ 0.05). Shoulder function and pain scores did not differ significantly between the two groups at 12 months postoperatively (P > 0.05). The CSA did not differ significantly between preoperative and postoperative 12 months in the traditional acromioplasty group (P > 0.05). However, 12 months postoperative CSA in the modified anterolateral acromioplasty group was significantly smaller than the preoperative CSA, with a statistically significant difference (P ≤ 0.05). The rates of rotator cuff re-tears were 16.67% (7/42) and 4% (2/50) in the two groups at 12 months postoperatively, respectively, with statistically significant differences (P ≤ 0.05). CONCLUSIONS: Traditional and modified anterolateral acromioplasty while treating total rotator cuff tears using arthroscopic rotator cuff repair significantly improves shoulder joint function. However, modified anterolateral acromioplasty significantly reduced the CSA value and decreased the incidence of rotator cuff re-tears.

Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note.

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model. METHODS: We developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration. RESULTS: The 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels. CONCLUSIONS: The findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

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

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

Percutaneous bone marrow concentrate and platelet products versus exercise therapy for the treatment of rotator cuff tears: a randomized controlled, crossover trial with 2-year follow-up.

BACKGROUND: Surgical repair is recommended for the treatment of high-grade partial and full thickness rotator cuff tears, although evidence shows surgery is not necessarily superior to non-surgical therapy. The purpose of this study was to compare percutaneous orthobiologic treatment to a home exercise therapy program for supraspinatus tears. METHODS: In this randomized-controlled, crossover design, participants with a torn supraspinatus tendon received either 'BMC treatment', consisting of a combination of autologous bone marrow concentrate (BMC) and platelet products, or underwent a home exercise therapy program. After three months, patients randomized to exercise therapy could crossover to receive BMC treatment if not satisfied with shoulder progression. Patient-reported outcomes of Numeric Pain Scale (NPS), Disabilities of the Arm, Shoulder, and Hand, (DASH), and a modified Single Assessment Numeric Evaluation (SANE) were collected at 1, 3, 6, 12, and 24 months. Pre- and post-treatment MRI were assessed using the Snyder Classification system. RESULTS: Fifty-one patients were enrolled and randomized to the BMC treatment group (n = 34) or the exercise therapy group (n = 17). Significantly greater improvement in median ΔDASH, ΔNPS, and SANE scores were reported by the BMC treatment group compared to the exercise therapy group (-11.7 vs -3.8, P = 0.01; -2.0 vs 0.5, P = 0.004; and 50.0 vs 0.0, P < 0.001; respectively) after three months. Patient-reported outcomes continued to progress through the study's two-year follow-up period without a serious adverse event. Of patients with both pre- and post-treatment MRIs, a majority (73%) showed evidence of healing post-BMC treatment. CONCLUSIONS: Patients reported significantly greater changes in function, pain, and overall improvement following BMC treatment compared to exercise therapy for high grade partial and full thickness supraspinatus tears. TRIAL REGISTRATION: This protocol was registered with www. CLINICALTRIALS: gov (NCT01788683; 11/02/2013).

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

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

The relationship between the duration and the retraction and atrophy grades in traumatic isolated full-thickness supraspinatus tears in young patients.

BACKGROUND: The study aimed to determine the grade of retraction and atrophy according to the time elapsed in traumatic isolated full-thickness supraspinatus (SS) tears in young patients. METHODS: One thousand twenty-six patients, who underwent arthroscopic shoulder surgery, were retrospectively reviewed. Pre-operative magnetic resonance imaging (MRI) of 69 patients aged 18 to 40 years with isolated traumatic full-thickness SS lesions remaining after exclusion criteria were evaluated for tendon retraction and atrophy grades. SS retraction was determined from a T2-weighted oblique coronal MRI slice, and the atrophy grade was determined from the T1-weighted oblique sagittal MRI slice. The patients were divided into four groups 0-1 month, 1-3 months, 3-6 months, and 6-12 months according to the time between trauma and MRI. The relationship of tendon retraction and muscle atrophy with elapsed time was evaluated, in addition, comparisons between groups were made. RESULTS: Thirty-one (45%) of the patients were female and their mean age was 30 ± 7.3 (18-40) years. The mean age of men was 30.5 ± 6.9 (18-39) years (p = 0.880). The time between rupture and MRI was moderately correlated with retraction and strongly correlated with atrophy grades (r = 0.599, 0.751, respectively). It was observed that there was a statistically significant difference between the 1st (0-1 month) and 2nd (1-3 months) groups (p = 0.003, 0.001, respectively), and between the 2nd and 3rd (3-6 months) groups (p = 0.032, 0.002, respectively), but there was no significant difference between the 3rd and 4th (6-12 months) groups (p = 0.118, 0.057, respectively). In addition, there was a moderate correlation between tendon retraction and atrophy grades (r = 0.668). Power (1- b) in post hoc analysis was calculated as 0.826. CONCLUSIONS: The current study, supported by arthroscopy, showed that there is a moderate and strong positive correlation between the time elapsed after trauma and the level of retraction and degree of atrophy in traumatic full-thickness SS tears, and demonstrated the importance of early surgical intervention in young patients.

Editorial Commentary: One- and 2-Year Outcomes Are Clinically Similar After Rotator Cuff Repair: What Are We Waiting For?

Research standards require reliable data from which we can draw accurate conclusions. For short-term outcome studies, one measure recommended by journals is preferring at least 2 years' minimum follow-up. In some cases, this is important to avoid false conclusions because of follow-up too short to detect either failure or complete improvement. However, although intended to prevent an incomplete picture, this mandate may not always add clinical utility. Recent data suggest that for rotator cuff repair outcomes, 1-year follow-up is clinically sufficient, making the 2-year recommendation an inconvenient and unnecessary standard. The widely accepted 2-year benchmark may be arbitrary and promotes a one-size-fits all approach; the approach can be evidence-based refined.

Editorial Commentary: Evidence for Patch Augmentation of Rotator Cuff Repair Is Weak.

Rotator cuff repair has a substantial failure rate despite various attempts to improve outcome and prevent a retear. Patch augmentation is an intuitively appealing approach to seek to reduce failure rate and improve outcomes for patients. Two main augmentation approaches are used: "on-lay" and "bridging." The literature is heterogeneous, and the best approach is uncertain. The evidence on patch augmentation for rotator cuff repair is both disparate and weak. Large randomized trials and registry data are required to move the field, ensure patient safety, and avoid wasting precious resources.

Editorial Commentary: Acellular Collagen Matrix Patch Augmentation of Large Rotator Cuff Tear Repair Results in Improved Healing.

Despite a high retear rate, repair of large rotator cuff tendon tear repairs shows good clinical outcomes. Unfortunately, these results often deteriorate with time, and large tears, not to mention progressively symptomatic retears, especially in compromised rotator cuff tissue, remain a problem. The solution could include augmenting repair with a patch such as an acellular collagen matrix. Proper patient selection is needed to achieve a benefit justifying the added expense and operative time associated with adding a patch. Biomechanically, such patches are strong and increase suture retention, as well as repair construct strength and stiffness. Patches provide a significant healing effect. Recent research and meta-analysis support the use of patches on rotator cuff tendon tears 3 cm or larger, whereas smaller tears (1-2 cm in length) appear to heal without the need for a patch.

Editorial Commentary: Biceps Rerouting Augmentation Technique Restores Biomechanics, Improves Healing, and Has Many Advantages for Repair of Large and Massive Rotator Cuff Tears.

The biceps rerouting (BR) augmentation technique has emerged as a useful option for the repair of rotator cuff tears when the torn tendon does not cover the footprint or can only be reduced under excessive tension. BR offers several advantages over traditional methods. It is an all-inside joint procedure, eliminating the need for skin incisions other than those for the arthroscopic portal, thus reducing operative time and infection risk. It does not lead to donor-site morbidity, unlike superior capsular reconstruction. In addition, the rerouted long head of the biceps tendon serves as a depressor of the humeral head and an internal splint, protecting cuff healing. Finally, it provides a biceps tenodesis such that biceps-related symptoms are prevented postoperatively. Clinical studies have shown the efficacy of the BR technique, particularly in achieving low rates of retear. Although the BR technique is a nonanatomic reconstruction, its biomechanical impact effectively restores joint function to a state similar to the original. Considering these findings, the BR technique represents a significant advancement in managing large to massive rotator cuff tears, given its straightforward application and ability to re-establish joint biomechanics.

Editorial Commentary: Artificial Intelligence Models Using Machine Learning Can Improve Preoperative Identification of Subscapularis Pathology.

Subscapularis pathology is difficult to diagnose, in part because of decreased sensitivity and accuracy in identifying tears with magnetic resonance imaging (MRI) when compared to other cuff tendons. Artificial intelligence evaluation of patient physical examination and MRI data using a machine learning model shows that arthroscopically confirmed partial- or full-thickness subscapularis tears are highly associated with abnormal subscapularis tendon length, long head of the biceps tears, and subscapularis fatty atrophy, and on physical examination, with weakness with internal rotation and positive lift-off, belly press, and bear hug tests. Today, physicians may use machine learning as a tool, but this model may not currently be sufficient to drastically change practice. However, with continued research and development, which is occurring rapidly, similar models could aid physicians in timely identification of pathology and optimization of preoperative planning, as well as physician training and education.

Editorial Commentary: Bone Marrow Stimulation or Microfracture May Not Enhance the Success of Arthroscopic Rotator Cuff Repair.

Bone Marrow Stimulation (BMS) is intended to provide a very low-cost, local source of marrow elements to improve healing and outcomes following rotator cuff repair. However, meta-analysis does not show that this results in improvement in rotator cuff tear outcomes or healing (as assessed by magnetic resonance imaging or ultrasound). That said, some studies do show lower retear rates with BMS; thus, when faced with challenged biology, this low-cost and low-risk solution may still have merit.

Editorial Commentary: Bio-inductive Collagen Implant to Augment Repair of Rotator Cuff Tears May Be Less Effective for Massive Tears and Revision Repair.

To improve healing after rotator cuff repair, synthetic, allograft, and dermal xenograft patches have been shown to significantly improve strength and load. Recent research has shown that a bio-inductive bovine collagen implant results in improvement in healing in partial-thickness, small, medium, and even large tears, but thus far, repair of massive and revision tears with augmentation is no better than repair alone. Optimizing these challenging repairs remains difficult and elusive.