American Journal of Sports Medicine最新文献

Background: The meniscotibial ligament (MTL) attaches to the posterior horn of the medial meniscus, which is essential in knee joint stability. Yet, its histological characteristics remain understudied. Understanding the histological composition of the MTL holds significant implications for comprehending its role in meniscal function and knee stability.

Purpose: To histologically analyze the MTL from its tibial insertion to its attachment to the meniscus, providing a 3-dimensional perspective.

Study design: Descriptive laboratory study.

Methods: Twelve paired glycerin-conserved knee specimens from 6 male cadavers were utilized. The posterior horn of the medial meniscus and the location of the meniscotibial attachment were identified. Measurements based on relevant landmarks were performed to coordinate fragment dissections. Laterality was systematically and randomly chosen to perform histological sections: sagittal, horizontal, or coronal. Postprocessing, histological sections were obtained and carefully analyzed.

Results: Histological analysis identified the MTL in all samples, exhibiting dense connective tissue with well-aligned type I collagen fibers extending from the tibia to a transition zone between the meniscus and the MTL. The MTL showed a higher collagen fiber density at its tibial attachment as compared with its body. At the ligament-meniscus transition zone, fiber continuity was not observed, with a collagen fiber distribution similar to that of the joint capsule. In the inferior portion of the meniscus, collagen fibers were more compact and organized, whereas in the rest of the meniscus, the transition zone and the joint capsule displayed fibers that were more disorganized and oriented in multiple directions.

Conclusion: This study identified 3 distinct zones within the MTL: its tibial insertion, characterized by dense, parallel collagen fibers; the MTL itself; and a transition zone with disorganized collagen fibers. Although the inferior surface of the meniscus shares histological similarities with the MTL, no anatomic continuity was observed. However, the transition zone appears to be a mechanically weak point.

Clinical relevance: Understanding the role of the meniscotibial complex and the fragility of the transition zone is key to managing ramp lesions. Repair should address the MTL and meniscal tissue for stability and be seen as a ligamentous, not just meniscal, repair.

Background: Clinicians increasingly rely on abstracts to assist with clinical decision-making. Spin is a bias that misrepresents research findings. The presence of spin in abstracts may mislead surgeons to believe a treatment is more effective than data suggest.

Purpose: To evaluate the presence of spin in abstracts of systematic reviews and meta-analyses on free bone block (FBB) procedures for glenohumeral instability.

Study design: Systematic review; Level of evidence, 4.

Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Scopus, and Web of Science databases were queried with the terms "bone block" and "shoulder." Studies were included if they met the following criteria: systematic reviews and/or meta-analyses regarding FBB procedures published in the English language in peer-reviewed journals. Abstracts were analyzed for 15 spin types. Study quality was assessed using AMSTAR 2 (Assessing the Methodological Quality of Systematic Reviews Version 2) categories. Study characteristics including year of publication, journal impact factor and CiteScore, and level of evidence were collected, and Fisher exact test was used to find correlations between spin and study characteristics. Statistical significance was defined as a P value ≤.05.

Results: A total of 23 studies were included in this study. Spin was identified in 21 (91.3%) studies, and the number of spin types present in a single study ranged from 0 to 7. Spin type 6 (selective reporting of or overemphasis on harm outcomes or analysis favoring the safety of the experimental intervention) was identified most frequently (17; 73.9%). A significant association was found between spin type 5 (the conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies) and scientific journal (P = .013), and between spin 9 (the conclusion claims the beneficial effect of the experimental treatment despite reporting bias) and year of publication (P = .010).

Conclusion: Spin is highly prevalent in abstracts of systematic reviews and meta-analyses investigating FBB for glenohumeral instability. Associations between spin and both year and journal of publication were identified. These results suggest that surgeons should use full texts to help inform conclusions when using systematic reviews and meta-analyses to determine the efficacy and safety of FBB for glenohumeral instability.

Background: Lateral extra-articular tenodesis (LET) can reduce the risk of graft failure after anterior cruciate ligament (ACL) reconstruction in adolescents and young adults. It is unclear whether the use of this procedure increases risks of complications such as arthrofibrosis after ACL reconstruction using hamstring autograft in adolescents.

Hypothesis: Adolescents treated with ACL reconstruction using hamstring autograft with and without modified Lemaire LET have similar rates of arthrofibrosis after surgery.

Study design: Retrospective cohort study; Level of evidence, 3.

Methods: Cases of ACL reconstruction using hamstring autograft performed by the senior author from January 1, 2012, to May 20, 2024, in patients aged 10 to 19 years were retrospectively reviewed. LET was not used before 2022 but was routinely used after 2022 based on accruing evidence supporting it. Baseline patient variables were recorded, as were surgical variables, including meniscal repair or meniscectomy, inclusion of LET, and femoral socket drilling method. Complications requiring return to the operating room (RTOR) were identified. Causes for RTOR were noted, including arthrofibrosis, which was defined as a range of motion deficit ≥5° of extension or ≥15° of flexion requiring lysis of adhesions and manipulation under anesthesia within 1 year of surgery.

Results: A total of 569 cases were included. Arthrofibrosis rates were similar for patients who underwent hamstring autograft ACL reconstruction with LET (1.2%; 95% CI, 0.03%-6.4%) versus those without LET (3.7%; 95% CI, 2.2%-5.8%) (P = .34).

Conclusion: The rate of arthrofibrosis requiring surgical intervention after hamstring ACL reconstruction is low (<6.5%). The addition of LET to hamstring ACL reconstruction in adolescent patients did not increase the risk of arthrofibrosis in this study.

Background: Distal tibial allograft (DTA) reconstruction has emerged as an effective option for the treatment of recurrent shoulder instability with glenoid bone loss (GBL). However, the ideal location for capsular repair during the procedure remains undetermined.

Purpose: To evaluate the effect of capsular repair location on humeral head positioning and anterior translation after DTA.

Study design: Controlled laboratory study.

Methods: Nine human cadaveric specimens (mean age, 62.2 years [range, 52-69 years]) underwent biomechanical testing in a simulated bone loss model. The rotator cuff tendons were loaded, and anterior stability testing was performed using a Kuka robot with the shoulder in 90° of abduction and neutral external rotation. A motion capture system recorded humeral head position and anterior translation. GBL (mean, 32%) was created, and a DTA graft was prepared to restore 100% of the native glenoid width. The following conditions were tested: intact, soft tissue Bankart lesion, DTA without capsular repair (DTA), DTA with capsule repaired to the graft (intra-articular), and DTA with capsule repaired to the glenoid (extra-articular). A repeated measures analysis of variance was performed to compare the translation and humeral head resting position between the five capsulolabral conditions.

Results: There was no difference in anterior translation when comparing DTA without capsular repair and the DTA with the capsule repaired to the graft (5.1 vs 5.3 mm; P > .999), and there was no difference in anterior translation between either of these conditions and the intact state (P > .999 for both). However, capsular repair to the glenoid demonstrated a significantly decreased anterior translation (0.7 vs 7 mm; P < .001) as well as a statistically significant posterior shift in the resting position (-2.5 vs 1.8 mm; P = .004) when compared with the intact state.

Conclusion: When performing a DTA reconstruction for large GBL, capsular repair to the native glenoid results in a more posterior resting humeral head position and less maximum anterior translation of the humeral head during time-zero biomechanical testing in cadaveric specimens. DTA without capsular repair and DTA with capsular repair to the graft restore glenohumeral position and motion closer to the native state.

Clinical relevance: Capsular repair to the native glenoid may overconstrain the glenohumeral joint when performing distal tibial allograft reconstruction in the setting of large glenoid bone loss, but further study is required to determine the impact on patient-reported outcomes or long-term arthritis risk.

Background: Compromised bone strength in proximal humerus osteoporosis predisposes patients with rotator cuff repair (RCR) to an increased anchor pull-out risk and healing failure.

Purpose: To explore the potential of locally administered alpha-ketoglutarate (αKG), a natural metabolite in the tricarboxylic acid cycle, to enhance rotator cuff healing by mitigating osteoporosis.

Study design: Controlled laboratory study.

Methods: A total of 48 female Sprague-Dawley rats were assigned into 4 groups: normal control (sham surgery), ovariectomy (OVX) control, OVX-rotator cuff tear (RCT) (RCR with fibrin application after OVX), and OVX-RCT-αKG (RCR with αKG-enriched fibrin treatment after OVX). Bilateral RCR was performed on rats in 2 RCT groups, with the respective application of fibrin or αKG-enriched fibrin gel at the tendon-bone interface (TBI). At 6 weeks and 12 weeks postoperatively, bone quality was evaluated using micro-computed tomography (CT), while histology and immunohistochemistry were used to assess bone, TBI, and tendon quality. Biomechanical tests determined the strength of the tendon-to-bone complex.

Results: Micro-CT analysis confirmed proximal humerus osteoporosis after OVX. Alpha-KG-enriched fibrin leads to improved bone quality compared with OVX-RCT, more prominent at 12 weeks after surgery, as evidenced by the higher bone volume/total volume fraction, trabecular number, and trabecular thickness. Histological and immunohistochemical analyses demonstrated enhanced bone regeneration and improved TBI integrity in the OVX-RCT-αKG group, which could be explained by decreased osteoclastic and increased osteoblastic activity. Biomechanical testing showed improved tendon-bone resilience, with higher ultimate failure load and stress after αKG treatment.

Conclusion: Local supplementation of αKG, a natural metabolite, along with the repair surgery could effectively improve proximal humerus osteoporosis, thereby enhancing RCR. It holds great potential for preventing anchor pullout and improving RCT outcomes in patients with osteoporosis.

Clinical relevance: Alpha-KG supplementation along with surgery may enhance RCR for patients with osteoporosis complications.

Background: Minimalist footwear and running retraining are often recommended by running coaches to reduce the risk of running-related injuries (RRIs) in endurance runners. However, despite the growing popularity of minimalist footwear and running retraining, there is limited scientific evidence supporting their effectiveness.

Purpose: To investigate the impact of minimalist footwear and running retraining on the incidence rate (primary outcome) and location (secondary outcome) of RRIs in recreational endurance runners.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: A total of 140 rearfoot runners were randomly assigned to 3 groups: minimalist footwear (n = 47), running retraining (n = 47), and control (n = 46). The minimalist footwear group received minimalist footwear, while the running retraining group completed 6 retraining sessions aimed at running softer, adopting a nonrearfoot strike, and increasing the initial step rate by 7.5%. The control group followed a stretching program. Running biomechanics were assessed at baseline and at 2, 6, and 12 months. RRIs were recorded according to recent consensus guidelines. The primary outcome was the RRI incidence rate, analyzed by adjusted (injury history) and unadjusted Cox regression models across 3 analyses: intention to treat, as treated, and per protocol.

Results: Sixty-four RRIs were reported: 55 overuse and 9 acute. No significant differences in the incidence rate of RRIs (primary outcome) were observed among groups across all analyses. There were also no differences in injury duration across groups in all analyses. However, the secondary outcome showed that injury distribution varied among groups in the as-treated and per-protocol analyses, with more hip injuries in the control group (P = .015 and P = .01, respectively) and more foot injuries in the running retraining group (P = .018 and P = .04).

Conclusion: Contrary to popular belief, neither minimalist footwear nor a softer running technique reduced the overall incidence rate of RRIs. However, running retraining altered injury patterns, decreasing hip injuries but increasing foot injuries.

Registration: NCT05499871 (ClinicalTrials.gov).

Background: Acromioclavicular (AC) joint dislocations are common in young athletes. The optimal management of Rockwood type 3 injuries, which involve a complete tear of both the AC and coracoclavicular (CC) ligaments, remains controversial.

Purpose/hypothesis: The purpose of this study was to compare the clinical outcomes of surgical and nonoperative treatment of type 3 AC joint dislocations. The hypothesis was that surgical treatment would result in superior functional outcomes.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: A total of 70 patients (mean age, 31.2 ± 8.1 years) with acute type 3 AC joint dislocations were randomized to the surgical (modified Weaver-Dunn technique) (n = 35) and nonoperative treatment group (n = 35). The inclusion criteria were as follows: adults aged >18 years diagnosed with grade 3 AC dislocation within 21 days of the injury; no history of AC dislocation or previous surgery in the affected shoulder; and no associated fractures involving the acromion, coracoid, or clavicle. The exclusion criteria were as follows: failure to adhere to the follow-up schedule; improper performance of radiological examinations; or noncompliance with the prescribed rehabilitation protocol. Ten patients were lost to follow-up, resulting in a final sample size of 60 patients (30 per group). The primary outcome was the Disabilities of the Arm, Shoulder, and Hand (DASH) score at 12 months. Secondary outcomes included the University of California-Los Angeles (UCLA) score, scapular dyskinesis, range of motion, radiographic alignment, cosmetic satisfaction, return to sport, and complications. Follow-up was conducted over 24 months. All statistical tests were 2-tailed, and P < .05 was considered statistically significant. No adjustments were made for multiple comparisons because of the exploratory nature of secondary outcomes.

Results: No significant differences were found in DASH scores (11.4 vs 10.63; P = .179) at final follow-up. The surgical group showed significantly higher UCLA scores (36.07 vs 33.74; P < .001) and lower rates of cosmetic dissatisfaction (14.8% vs 44%; P = .017), although the range of motion, return to sport, scapular dyskinesis, and complication rates did not differ between groups.

Conclusion: Surgical management of type 3 AC joint dislocations resulted in similar DASH scores and range of motion compared with nonoperative management, although some secondary outcomes-including higher UCLA scores and cosmetic satisfaction scores-favored surgery.The trial was registered in the Brazilian Registry of Clinical Trials (RBR-4r6jhy6).