Journal of Shoulder and Elbow Surgery最新文献

Background: The utility of latissimus dorsi (LD) transfer combined with reverse total shoulder arthroplasty (rTSA) to restore external rotation (ER) strength is clinically well-established, but studies directly comparing LD and intact teres minor (TM) strength are lacking. Also, variations in eccentricity in the glenoid components have been under-estimated.

Methods: We used eight fresh-frozen cadaveric shoulders in this study. LD transfer to the posterolateral aspect of the greater tuberosity was simulated using a cable pulley system. We explored six possible conditions: massive rotator cuff tears (RCTs) (supraspinatus and infraspinatus tears), massive RCTs with TM tears, massive RCTs with TM tears and LD transfer, and all three conditions complicated by centric and eccentric glenoid components. We measured the impingement-free range of motion (IFROM), the ER torque (N*m), the maximum abduction angle on successive loading of the middle deltoid (the abduction capacities), and the anterior dislocation forces.

Results: Use of an eccentric glenosphere was associated with greater IFROM in all directions, but the differences in ER strength, abduction capability, and anterior dislocation force compared with a centric design were not significant. LD transfer with TM tears showed significantly greater ER strength than massive RCTs condition at 30° (P<0.05) and 60° (P<0.05) of abduction. TM tears, with or without LD transfer, had less anterior stability than an intact TM (P<0.05). Massive RCTs combined with TM tears tended to be associated with an increased abduction angle under the same deltoid load across all tested loads, revealing the key role played by the TM in joint stability and ER.

Conclusions: LD transfer enhanced ER abduction strength in the absence of an intact TM, in contrast to a massive RCT with an intact TM. The TM was found to play a significant role in stability. Greater ROM in all directions was achieved with an eccentric than with a centric glenosphere.

Background: The ulnar collateral ligament (UCL) stabilizes the elbow during overhead throwing activities. Repetitive throwing can cause valgus laxity even without injury. Shear-wave ultrasound elastography (SWE) is a novel imaging technique that assesses tissue elasticity. This study aimed to assess UCL elasticity in college baseball players using SWE under resting and valgus stress conditions.

Methods: The study included 30 healthy male college baseball players (mean age 20.48 ± 1.34 years). The dominant and non-dominant arms of participants were examined, excluding those with a history of UCL injury. UCL thickness was measured using conventional ultrasound, and elastography was conducted at the same sites. Measurements were repeated under valgus stress, and the ulnohumeral joint gap was recorded. Participants were categorized into throwing and non-throwing arm groups. A subgroup analysis of the throwing arm was conducted based on joint laxity, defined as an increase of >1 mm in the ulnohumeral joint gap under valgus stress, which is associated with UCL injury and joint laxity. Correlations between UCL evaluation parameters and changes in ulnohumeral gap were analyzed.

Results: Out of 54 elbows, 26 were classified as throwing and 28 as non-throwing. The throwing group had a significant increase in the ulnohumeral gap compared to the non-throwing group. The ulnohumeral gap under valgus stress increased from 0.59 to 0.72 cm (p=0.01). There was no significant difference in shear-wave velocity (SWV) between the two groups. Within the throwing group, 13 elbows were classified as lax arms and 15 as non-lax arms. The SWV of the lax arms (6.71 ± 4.59 m/s) was significantly lower than that of the non-lax arms (8.54 ± 5.17 m/s) (p=0.045). Multiple regression analysis showed that UCL thickness and SWV were independently correlated with the rate of change in the ulnohumeral gap (ß=0.335, p=0.018 and ß=-0.319, p=0.013, respectively).

Conclusion: Valgus laxity of the elbow joint can be evaluated based on the elasticity of the UCL measured above the joint line using SWE at rest. Thickened UCL may exhibit a decrease in function; therefore, physicians should not evaluate the joint status solely on the basis of the structural properties on conventional ultrasound.

Background: The indications for glenohumeral arthrodesis are severe lesions of the supra-clavicular brachial plexus. This is a demanding surgery with numerous complications. To reduce morbidity, a few rare arthroscopic techniques have been developed. We compared arthroscopic shoulder arthrodesis with open arthrodesis. Our hypothesis is that the results of arthroscopic arthrodesis would be at least as good as open arthrodesis in terms of strength and mobility, and better in terms of complications.

Methods: Sixteen patients underwent arthrodesis for sequelae of complete brachial plexus palsy between 2008 and 2022. The procedures were performed in our university hospital by experienced surgeons. Six patients underwent open arthrodesis, and 10 arthroscopically. Data were collected retrospectively. A clinical assessment was carried out preoperative and monthly until bone fusion. Clinical examination included measurement of flexion, abduction and rotation amplitudes. Strength was assessed. Secondary endpoints included pain assessment, operative time, American Shoulder and Elbow Surgeons index, Disabilities of the Arm, Shoulder and Hand score and Simple Shoulder Test. Radiographs were analyzed at each consultation until bone fusion was acquired.

Results: The average age of the patients was 28 years. Mean follow-up time after arthrodesis was 49.38 months. There was no statistically significant difference between the two groups on preoperative data. The vast majority of brachial plexus palsies were due to road traffic accidents. Patients underwent arthrodesis an average of 29 months after the accident. There was a statistically significant difference (p = 0.034) in the postoperative complication rate in favor of the arthroscopic group. There was no significant difference in mobility or strength. There were no significant differences in pain levels or scores, either pre- or postoperatively.

Conclusion: The results of arthroscopic shoulder arthrodesis are at least as good as open arthrodesis in terms of strength and mobility, and better in terms of complications. The most frequent complications are pseudarthrodesis, humeral fractures, infection and pain. It would be interesting to carry out a multicenter, prospective study to confirm our results.

Purpose: Using modern implants, even complex radial head and neck fractures can often be reconstructed. However, metaphyseal comminution is associated with delayed bone healing and an increased risk for loss of reduction. Hence, this biomechanical in-vitro study intended to evaluate the mechanical stability of a bone graft from the ipsilateral proximal ulna in plate fixation of comminuted radial neck fractures.

Methods: Osteotomies at the level of the radial neck with a 3 mm defect were created on 20 fresh-frozen proximal radius specimens to simulate metaphyseal comminution. Fixation was performed with a locking radial head plate in group A and with an additional structural bone graft from the ipsilateral ulna in group B. Cyclic loading from 5-100 N was performed and axial displacement and stiffness were evaluated.

Results: The axial displacement was larger in group A (0.81 ± 0.24mm) than in group B (0.52 ± 0.27mm) (p=0.02). Group B had a higher axial stiffness compared to group A (300 (127 - 958)N/mm vs. 163 (82 - 209)N/mm, p=0.015).

Conclusion: In the case of metaphyseal comminution of radial head/neck fractures, additional bone graft augmentation from the proximal ulna results in significantly increased stability of locking plate fixation. Future clinical research should focus on whether this leads to improved union rates of these challenging fractures.

Background: Rotator cuff tears (RCTs) often result in muscle atrophy, compromising surgical outcomes and recovery. Mitochondrial dysfunction is implicated in this process, suggesting potential for mitochondria-based therapies. This study aimed to investigate the effects of platelet mitochondria (Plt-Mito) administration into the supraspinatus muscle (SSP) following RCTs.

Methods: Seventy-two male Sprague-Dawley rats were allocated into three distinct groups: (1) a sham surgery group, (2) a group with RCTs treated with Plt-Mito, and (3) a group with RCTs treated with PBS. Treatments were administered every two weeks. After 12 weeks, the supraspinatus muscles were analyzed for wet muscle weight ratio, muscle fiber cross-sectional area (CSA), fibrosis, antioxidant activity, mitochondrial markers, capillary density and mitochondrial structure.

Results: Plt-Mito successfully incorporated into SSP, maintaining functional integrity. Compared to the PBS group, Plt-Mito treatment significantly preserved wet muscle weight, increased mean muscle fiber CSA, promoted muscle regeneration, reduced fibrosis, enhanced antioxidant activity (increased superoxide dismutase activity and decreased malondialdehyde activity), improved muscle vascularity (increased CD31 and α-SMA), increased expression of mitochondrial markers (COX IV and UCP-1) and maintained mitochondrial density and structure.

Conclusions: Our findings demonstrated Plt-Mito administration effectively halted muscle atrophy and fibrosis, while attenuating mitochondrial damage and dysfunction following RCTs.

Background: Revision shoulder arthroplasty procedures pose unique challenges to shoulder surgeons. Efforts to mitigate bone loss, blood loss, operative time, and intraoperative complications may prompt the surgeon to consider retaining well-fixed components and combine them with components of a different manufacturer. This concept, known as mismatching, represents a viable solution to a dilemma encountered in the revision setting. The purpose of this study is to compare the clinical outcomes between patients treated with matched versus mismatched implants in revision shoulder arthroplasty.

Methods: All revision shoulder arthroplasty cases performed by a single surgeon between 2012 and 2022 were reviewed. Using radiographs and operative reports, 44 patients were identified as mismatches, defined by humeral and glenoid components made by two different manufacturers. Demographic data, pre- and postoperative range of motion, and patient-reported outcomes measures (ASES, VAS, SST, Stability) were collected. A larger cohort of all revision arthroplasties by the same surgeon (n=574) was then used to perform a matched cohort analysis based on indication for revision. Rate of re-revision and patient-reported outcomes were then compared using simple statistics.

Results: Twenty-five of the 44 total mismatches had a minimum of 1-year follow-up. Indications for revision included 13 failed reverse shoulder arthroplasty (rTSA), 9 failed anatomic total shoulder arthroplasty (aTSA) and 3 failed hemiarthroplasty (HA). All were revised to rTSA. In the matched cohort analysis (n=25 mismatches, n=281 matches), there were no differences in mean ASES Score, VAS Pain Score, or SST at 1 year postoperatively. However, stability was significantly higher for mismatches (5.9) compared to matches (3.5), on a 0-10 scale with 10 being most stable (p = 0.039). There was an 11% (n=5) re-revision rate among mismatches, compared to 13% among matches in the total revision cohort. Of the 44 total manufacturer-mismatched cases, 11 were also size-mismatched (differing glenosphere and socket size), and none of these required re-revision within the available short-term follow-up period.

Discussion: Patients treated with mismatched components in this study demonstrated similar clinical outcomes and revision rates to those treated with matched components in revision shoulder arthroplasty. While promising, these results are limited by a small sample size and short-term follow-up. A more definitive conclusion about the practice of mismatching implants will require further research with larger data sets and longer follow-up.

Background: Shoulder dislocations may lead to anterior glenoid rim fractures. An all-arthroscopic double-row repair, referred to as bony Bankart bridge (BBB), has been proposed with superior biomechanical properties when compared to single-row repair techniques. The aim of the present study was to evaluate the minimum 10-year clinical and functional outcomes following BBB.

Methods: All consecutive patients that underwent arthroscopic BBB for the treatment of shoulder instability with an associated bony Bankart lesion by a single surgeon between December 2007 and February 2013 were eligible for inclusion. Preoperatively and minimum 10 years postoperatively, patient-reported outcome measures (American Shoulder and Elbow Surgeons [ASES] Score, short version of the Disabilities of the Arm, Shoulder and Hand questionnaire [QuickDASH], Single Assessment Numeric Evaluation [SANE], 12-Item Short-Form Health Survey Physical Component Summary [PCS-12]), satisfaction with the postoperative result [1-10 scale with "10" indicating maximum satisfaction], and Visual Analog Scale [VAS] for pain), return to sport rates, as well as instability recurrence and revision surgery rates were evaluated.

Results: Eleven patients (100% male) with a mean age at the time of surgery of 48.0 (interquartile range, 31.0-62.0) years were evaluated 14.0 (11.0-14.0) years postoperatively. At long-term follow-up, significant improvements in shoulder function (ASES Score: 74.9 [30.8-90.8] vs. 100 [98.3-100], P < .001; QuickDASH: 13.6 [10.0-63.6] vs. 0.0 [0.0-6.8], P = .002; SANE: 50.0 [19.0-90.0] vs. 96.0 [89.0-99.0], P = .002) and physical health (PCS-12: 44.1 [35.1-55.7] vs. 57.3 [56.5-58.5], P < .001) were observed. Median satisfaction with the postoperative outcome was high (10 [5.0-10]). Pain levels were low (VAS for pain: 0 [0-0]). Ten patients reported their postoperative sporting activity level with the majority patients reporting sporting activity levels equal to or above (70.0%) their pre-injury level. One patient (9.1%) reported a shoulder re-dislocation during follow-up. No patients underwent further surgery for instability or post-traumatic osteoarthritis (PTOA).

Conclusion: The arthroscopic BBB for patients with bony Bankart lesions is associated with excellent shoulder function, low pain levels and high return to sport rates at long-term follow-up. One patient suffered a shoulder re-dislocation, but did not require revision surgery. No patients underwent further surgery for PTOA during follow-up.

Background: Injuries to the ulnar collateral ligament (UCL) are increasing among baseball players at all levels. Little is known about the loads experienced by the medial elbow during baseball hitting. The purpose of this study was to describe the stress experienced by the medial elbow of the trail arm during baseball hitting. We hypothesized that the biomechanical comparison of hitting will demonstrate greater elbow varus torque of the trail arm for wood versus aluminum bat and inside versus other swing locations.

Methods: Thirteen healthy National Collegiate Athletics Association Division 1 baseball players were analyzed hitting plastic balls from a tee at 4 different swing locations (dry [no contact], inside, middle, and outside) using two different bats (wood and aluminum). Biomechanical models were generated for each subject from video motion capture data and the peak elbow varus torque and bat swing velocity were calculated for each trial.

Results: The average peak elbow varus torque during hitting was 22.15 +/- 4.79 N-m. There were no interactive effects between bat type and swing location type (P = 0.99) and no effect of bat type on peak elbow varus torque (P = 0.85) or swing velocity (P= 0.81). Swings to the outside location generated greater elbow varus torque than dry swings or swings to the inside location (P < 0.01). Greater swing velocities were observed for swings to the outside location compared to other locations (P < 0.01) CONCLUSION: The peak elbow varus torque on the trail arm during a baseball swing is lower than both the throwing and ultimate load to failure of the UCL. Additionally, both elbow varus torque and swing velocity were greatest when swinging to the outside location.

Purpose: To report the return to sport (RTS) rate, RTS time, and performance outcomes in professional baseball pitchers and position players who underwent isolated posterior labrum repair.

Methods: The MLB Health and Injury Tracking System (HITS) database was queried for all major league and minor league baseball players who underwent isolated posterior labrum repair from 2011-2022. Players were excluded if they underwent labrum débridement instead of repair, if they underwent concomitant SLAP or anterior labrum repair, or if they had multi-directional instability. Outcomes of interest included RTS rate, RTS time, workload statistics, and performance outcomes. Outcomes were compared between pitchers and position players, with further sub-analyses between starting vs. relief pitchers as well as between outfielders/infielders/catchers.

Results: Overall, 133 professional baseball players including 78 pitchers and 55 position players were included. Position players were able to RTS at a higher rate than pitchers (91.0% vs. 74.5%, p=0.020) and were able to RTS sooner (251 days vs. 330 days, p<0.001) than pitchers. RTS rate did not differ between starting and relief pitchers (76.2% vs. 69.2%, respectively, p=0.719), however starting pitchers took longer to RTS than relief pitchers (348 days vs. 268 days, p=0.013). Position players who underwent repair of the throwing shoulder returned to sport 74 days later (296 days vs. 222 days, p<0.001) than position players who underwent repair of the non-throwing shoulder, and position players who underwent repair of the trail (facing the catcher) batting shoulder returned to sport 96 days later (317 vs. 221 days, p<0.001) than position players who underwent repair of the lead (facing the pitcher) batting shoulder. Pitching workload returned to baseline by the second season postoperatively.

Conclusion: Professional baseball pitchers are able to return to sport less frequently and take longer to return to sport than professional baseball position players. Undergoing repair of the throwing or trail batting shoulder can delay return to sport by several months. Pitching workload returned to baseline by the second season postoperatively.

Background: Guidance technology in total joint arthroplasty has gained popularity over the last few decades. Computer-assisted navigation (CAN) was recently introduced for glenoid implantation in total shoulder arthroplasty (TSA). However, utilization trends of CAN TSA are not currently known. This study aims to determine the prevalence and trends of CAN usage in TSA from its introduction in 2017 until 2023.

Methods: A retrospective review was performed of all TSAs (anatomic TSA [aTSA] or reverse TSA [rTSA]) implanted using a single computer navigation shoulder system (ExactechGPS; Gainseville, FL, USA). Intraoperative navigation was performed for the glenoid component only. Utilization of CAN was reported per year to determine trends in the prevalence of CAN cases, number of users, new users, dropped users, high-volume users (>50 CAN cases/year), and the number of cases completed by high-volume users. The data was also stratified by type of TSA (aTSA vs. rTSA) and type of glenoid component used (augmented or non-augmented).

Results: From 2017 to 2023, navigated TSAs increased from 654 to 9777 cases per year, with a greater increase in navigated rTSA than aTSA volume. The number of CAN cases using augmented implants grew 1435% while non-augmented implants grew 1352%. By 2023, the overall number of CAN users increased from 79 to 667 users. High-volume CAN surgeons increased to 50 users by 2023. Over this period, the number of CAN TSA performed by high-volume surgeons increased more rapidly than the actual number of high-volume surgeons per year.

Conclusions: This study demonstrates an exponential increase in the use of CAN for TSA in the last eight years. This increase is driven by progressive growth in both the volume of new users as well as CAN TSAs performed by existing users by several hundred folds. These upwards trends in utilization of guidance technology for TSA are likely to continue in future.