Journal of Shoulder and Elbow Surgery最新文献

Background: Lesser tuberosity osteotomy (LTO) repair in total stemless shoulder arthroplasty has a high nonunion rate and thus presents a challenge to shoulder surgeons. Improved repair techniques may mitigate nonunion from excessive fragment motion or inadequate compression. The purpose of this study was to evaluate the biomechanical properties of 3 LTO repair techniques in the setting of stemless shoulder arthroplasty. Tensionable cortical button (Button) and suture anchor (Anchor) constructs were compared to a reference suture with a lateral plate construct (Suture).

Methods: Forty human cadaveric shoulders from 20 matched pairs were dissected and the lesser tuberosity osteotomized. In each pair, the LTO was repaired with a Suture and lateral plate construct on one side and on the other side, either a tensionable cortical Button or suture Anchor construct was used. Sutures were passed through the humeral components of a stemless arthroplasty system during the procedures. All specimens were cycled 1,000 times from 10 to 100 N at 1 Hz using a custom subscapularis cryoclamp. Cyclic construct gapping was recorded at regular intervals with a digital video system. All specimens were then loaded to failure, and failure load, displacement, mode, and construct stiffness were recorded. Statistical analyses compared the Suture constructs to their paired Button or Anchor constructs.

Results: Compared to their Suture pairs, the Button group displayed no differences in construct gapping (P ≥ .138), but the Anchor group displayed up to 50% increased gapping from cycles 1-400 (P ≤ .049). The Suture construct supported approximately 25% higher loads prior to failure when compared to their paired Button and Anchor group (P ≤ .014). There were no differences in failure stiffness between the Sutures and their paired Buttons or Anchors.

Conclusion: In this controlled laboratory study, the decreased rate of initial construct gap formation and greater failure load of the suture construct suggests an environment for superior in vivo healing of the LTO as a result of decreased micromotion, with clinical implications still to be determined. Furthermore, the greater failure load in the suture construct could prevent catastrophic failure of the LTO in the delicate postoperative period. In the setting of total shoulder arthroplasty, an LTO subscapularis repair using a suture with a lateral plate construct provides a biomechanically superior repair to either a tensionable cortical button or suture anchor repair.

Background: The advent of modern, precontoured locking plates has improved treatment of distal humerus fractures (DHFs) by providing an anatomic fit and a reliable locking mechanism with interdigitating screws. However, severe articular comminution may predispose surgical failure despite anatomic reduction and a biomechanically strong construct.

Methods: A retrospective review was performed to identify patients who underwent distal humerus open reduction internal fixation (ORIF) between 2015 and 2020. Fractures were classified using the AO/OTA classification and further categorized by anatomic location and number of fragments on preoperative imaging. Articular comminution was defined as the number of articular fracture fragments ≥1.5 cm and stratified as high (≥5 fragments) and low (<5 fragments) comminution. Outcomes included elbow range of motion, quick Disabilities of the Arm, Shoulder and Hand (qDASH), and Mayo Elbow Performance Score (MEPS). Complications were classified as major or minor based on the need for reconstructive reoperation. Outcomes and complications between high- and low-comminution DHFs were compared using Student t test and Fisher exact test.

Results: The study cohort consisted of 51 patients, 38 female (75%) and 13 male (25%), with a mean age of 63.3 years. Fracture types included 9 AO/OTA type A, 7 type B, and 35 type C. At a mean follow-up of 47 months, the mean arc of motion in the high-comminution group was 104° vs. 109° in the low-comminution group (P = .595). The mean MEPS was 79 vs. 88 (P = .376), and the mean qDASH score was 29 vs. 19 (P = .219) in the high-comminution and low-comminution groups, respectively. Among the intra-articular fractures, patients with high-comminution fractures experienced significantly more major complications (87.5% vs. 16.3%, P < .001) and overall complications (87.5% vs. 30.2%, P = .001) compared with those in the low-comminution group. Major complications in the high-comminution group included bone resorption with conversion to arthroplasty and radical contracture releases with heterotopic ossification excision. Major complications in the low-comminution group included nonunion, elbow contractures, deep infection, and bone resorption with implant failure. All highly comminuted fractures achieved satisfactory reduction with parallel-plate fixation. Final qDASH and MEPS scores were not affected by comminution severity, although a significantly higher proportion of patients required revision surgery in the high-comminution group.

Conclusion: Precontoured locking plates provide reliable fixation for intra-articular DHFs. However, severe articular comminution is associated with complications resulting in major reconstructive reoperations, even with satisfactory fixation. Despite this, conversion to total elbow arthroplasty remains low.

Hypothesis/background: Fatty infiltration (FI) and muscle atrophy following rotator cuff (RC) tears are largely irreversible and are major determinants of poor surgical outcomes, increased re-tear risk, and long-term functional disability. No pharmacologic therapies have been validated to prevent or reverse these degenerative changes. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), including liraglutide, have demonstrated antiadipogenic and tissue-preserving effects in other organ systems, suggesting potential application in RC-related muscle degeneration. We hypothesized that systemic liraglutide administration would attenuate FI, preserve muscle morphology, and improve functional outcomes in a rat model of chronic RC tear without tendon repair.

Purpose: To evaluate the effects of systemic liraglutide administration on FI, muscle morphology, and functional outcomes in a rat model of chronic RC tear without tendon repair.

Study design: A controlled laboratory study.

Methods: Adult male Sprague-Dawley rats underwent unilateral supraspinatus tendon transection with interposition of a silicone tube to prevent tendon-to-bone healing. Animals were randomly assigned to receive intraperitoneal liraglutide (250 ㎍/kg/d) or saline for 4 weeks, starting 2 weeks postinjury. At 6 weeks postsurgery, FI was assessed using Oil Red O staining, muscle morphology was examined via hematoxylin-eosin histology, and passive shoulder range of motion was measured with a goniometer. Neuromuscular function was evaluated through compound muscle action potential recordings, and FI was quantified as the percentage of red-stained FI area using ImageJ software with a uniform color-threshold algorithm.

Results: GLP-1RA significantly reduced FI compared with controls (Oil Red O-positive area: 1.11 ± 0.75% vs. 11.82 ± 3.89%, P < .001) and markedly decreased adipocyte deposition on H&E staining. Passive internal rotation was preserved (79 ± 38° vs. 70 ± 2°, P < .001), as was external rotation (55 ± 2° vs. 48 ± 3°, P < .001). Compound muscle action potential amplitudes were significantly greater in the liraglutide group (19.43 ± 8.77 mV vs. 7.61 ± 3.15 mV, P = .028).

Conclusion: Systemic liraglutide administration attenuated chronic muscle degeneration after RC tear by limiting FI, preserving muscle fiber morphology, maintaining joint mobility, and supporting neuromuscular function. These findings provide preclinical justification for therapeutic repositioning of GLP-1RAs in musculoskeletal disorders characterized by irreversible fatty degeneration.

Background: Hand-behind-back (HBB) motion is commonly used to assess shoulder internal rotation; however, it involves multiple joint movements, including scapulothoracic, glenohumeral, and elbow joint motions, thus complicating the interpretation of the HBB position. This study aimed to investigate 3-dimensional joint alignment during HBB motion of the bilateral shoulders in patients with frozen shoulder and to identify which joint motions primarily contribute to motion limitation.

Methods: Seventeen patients with unilateral frozen shoulder underwent bilateral shoulder computed tomography scans in the neutral and HBB positions using an upright multidetector computed tomography. Bone surface models of the thorax, scapula, humerus, and forearm were created to calculate the rotation of the scapulothoracic, glenohumeral, thoracohumeral, and elbow joints. The affected and unaffected sides were compared, and the correlation between the HBB reach level (vertebral level) and the thoracohumeral internal rotation angle was analyzed.

Results: No significant differences in joint rotation were observed between the sides in the neutral position. The affected side demonstrated significantly reduced glenohumeral internal rotation (31° vs. 66°, P < .001), abduction (10° vs. 22°, P < .001), and elbow flexion (74° vs. 115°, P < .001) during HBB motion. The scapulothoracic joint on the affected side had less internal rotation (18° vs. 21°; P = .045) and more anterior tilt (24° vs. 19°; P = .003). The HBB reach level was negatively correlated with the thoracohumeral internal rotation angle in the unaffected and affected sides (r = -0.518 and r = -0.675, respectively).

Conclusion: This study clarified that limited internal rotation of the glenohumeral joint is the main cause of restricted HBB motion in frozen shoulder, which supports the use of the thumb-to-spinous process as a valid measure of thoracohumeral internal rotation in patients with frozen shoulder.

Background: Olecranon fractures occur more commonly in older individuals. For patients aged ≥70 years, operative management is often considered standard of care, although recent evidence has supported nonoperative treatment in frail and/or elderly patients. With evolving treatment indications, more granular evidence is beneficial to guide patient-specific decision-making. The aim of this investigation was to explore patient and treatment factors associated with outcomes after displaced, closed olecranon fractures in older individuals.

Methods: This retrospective cohort study with prospective data collection included 113 patients (mean age 81; 81% female) aged ≥70 years with displaced, stable olecranon fractures (Mayo 2A/2B). Patients were treated operatively via precontoured olecranon locking plates (n = 68) or tension band wiring (n = 6) or nonoperatively (n = 39) with progressive mobilization. Frailty was quantified using the Clinical Frailty Scale. The primary outcome was Quick Disabilities of the Arm, Shoulder, and Hand score. Secondary outcomes included range of motion, Patient-Reported Outcomes Measurement Information System (PROMIS) global health, and complications. Mean time from injury to outcome collection was 16 ± 2 months.

Results: Mean Quick Disabilities of the Arm, Shoulder, and Hand was lower in the operative cohort (mean difference -8.3; 95% confidence interval: 0.4-16.2; P = .021), although the difference was not clinically meaningful (minimal clinically important difference = 15). Subgroup analysis by frailty revealed no differences between operative and nonoperative management in the mildly frail and moderate to severely frail subgroups. Linear regression identified frailty was associated with limb-specific disability (β = 4.86; P = .001); age was not a significant predictor when controlling for frailty. In the plate fixation group, engaging the proximal fragment fixation with <3 screws was associated with proximal fragment escape (β = 3.13, standard error = 0.94, odds ratio = 22.9, 95% confidence interval: 3.63-144.8, P = .001) independent of fragment size, comminution, and triceps reinforcement. In the nonoperative group, increasing immobilization duration was associated with decreased arc of motion (β = -4.1, standard error = 1.3, R² = 0.29, P = .006).

Conclusion: This study reinforces recent Level I evidence suggesting that operative management of displaced olecranon fractures does not result in superior long-term functional outcomes for the average older patient. Frailty, rather than chronological age, is a primary driver of limb-related disability. Early mobilization is a low-risk alternative to operative management. When surgery is pursued to achieve faster recovery or improved early elbow extension, surgeons should ensure robust proximal fragment fixation with at least 3 screws to minimize the risk of failure.