Tranexamic Acid Can Reduce Early Tendon Adhesions After Rotator Cuff Repair and Is Not Detrimental to Tendon-Bone Healing: A Comparative Animal Model Study.

PURPOSE: To determine the effects of topical tranexamic acid (TXA) administration on tendon adhesions, shoulder range of motion (ROM), and tendon healing in an acute rotator cuff repair rat model. METHODS: A total of 20 Sprague Dawley rats were used. Tendon adhesion, ROM, and biomechanical and histological analysis of tendon-bone healing was conducted at 3 and 6 weeks after surgery. The rats underwent rotator cuff repair surgery on both shoulders and were administered TXA via subacromial injections. The tendon adhesion was evaluated macroscopically and histologically. Biomechanical tendon healing was measured using a universal testing machine, and histological analysis was quantified by H&E, Masson's trichrome, and picrosirius red staining. RESULTS: At 3 weeks after surgery, the adhesion score was significantly lower in the TXA group (2.10 ± 0.32) than in the control group (2.70 ± 0.48) (P = .005), but there was no significant difference between the 2 groups at 6 weeks. Regarding ROM, compared with the control group, the TXA group showed significantly higher external rotation (36.35° ± 4.52° vs 28.42° ± 4.66°, P < .001) and internal rotation (45.35° ± 9.36° vs 38.94° ± 5.23°, P = .013) 3 weeks after surgery. However, at 6 weeks, there were no significant differences in external and internal rotation between the 2 groups. In the biomechanical analysis, no significant differences in gross examination (3 weeks, P = .175, 6 weeks, P = .295), load to failure (3 weeks, P = .117, 6 weeks, P = .295), or ultimate stress (3 weeks, P = .602, 6 weeks, P = .917) were noted between the 2 groups 3 and 6 weeks after surgery. In the histological analysis of tendon healing, no significant differences in the total score (3 weeks, P = .323, 6 weeks, P = .572) were found between the 2 groups 3 and 6 weeks after surgery. CONCLUSIONS: Topical TXA administration showed a beneficial effect in reducing tendon adhesions and improving ROM 3 weeks postoperatively and had no effect at 6 weeks. This suggests that additional intervention with TXA may be useful in achieving long-term improvement in shoulder stiffness. Additionally, TXA may increase tissue ground substance accumulation in the late postoperative period but does not adversely affect tendon-bone interface healing. CLINICAL RELEVANCE: The use of TXA after rotator cuff repair has no effect on tendon-bone interface healing in clinical practice and can improve shoulder stiffness in the early postoperative period. Additional research on the long-term effects is needed.

Current research trends on the effect of diabetes mellitus on rotator cuff tendon healing/tendinopathy.

Rotator cuff tendon tears are a leading cause of shoulder pain. They are challenging to treat, and tendon-bone healing has a high failure rate despite successful surgery. Tendons connect the muscles and bones, which make them important for the body's overall mobility and stability. Metabolic diseases, including diabetes or high blood pressure, can affect the healing process after repair of a damaged tendon. With a global incidence of 9.3%, diabetes is considered as a significant risk factor for rotator cuff tendon healing because it causes structural, inflammatory, and vascular changes in the tendon. However, the mechanisms of how diabetes affects tendon healing remain unknown. Several factors have been suggested, including glycation product accumulation, adipokine dysregulation, increased levels of reactive oxygen species, apoptosis, inflammatory cytokines, imbalanced matrix-metalloproteinase-to-tissue-inhibitor ratio, and impaired angiogenesis and differentiation of the tendon sheath. Despite the effects of diabetes on tendon function and healing, few treatments are available to improve recovery in these patients. This review summarizes the current literature on the pathophysiological changes of the tendon in diabetes and hyperlipidemia. Preclinical and clinical evidence regarding the association between diabetes and tendon healing is presented. Moreover, current approaches to improve tendon healing in patients with diabetes are reviewed.

Types and doses of anti-adhesive agents injected into subacromial space do not have an effect on the clinical and anatomical outcomes after arthroscopic rotator cuff repair.

PURPOSE: Joint stiffness after arthroscopic rotator cuff repair is a major concern for orthopaedic surgeons. Various antiadhesive agents are commonly administered after rotator cuff repair for its prevention. This study aimed to compare the outcomes among patients injected with different types and amounts of anti-adhesive agents after rotator cuff repair. It was hypothesized that the outcomes might differ depending on the use of the anti-adhesive agent and its type and dose. METHODS: A total of 267 patients who underwent arthroscopic rotator cuff repair with or without subacromial injection of anti-adhesive agents were enrolled. The first group (group A; 51 patients) were injected with 3 mL of poloxamer/sodium alginate-based anti-adhesive agent. The second group (group B; 93 patients) were injected with 3 mL of sodium hyaluronate-based anti-adhesive agent. The third group (group C; 82 patients) were injected with 1.5 mL of sodium hyaluronate-based anti-adhesive agent. Finally, the last group (group D; 41 patients) who did not use anti-adhesive agents served as the control. The range of motion (ROM) and pain VAS scores were measured preoperatively and at 5 weeks, 3 months, 6 months, and 1 year postoperatively. Functional outcomes were evaluated using American Shoulder and Elbow Surgeons and Constant scores, whereas cuff integrity was assessed via MRI or ultrasonography at least 6 months postoperatively. RESULTS: All ROM measurements, pain VAS scores, and functional scores were significantly improved regardless of the use, type, and dose of the anti-adhesive agents. In addition shoulder ROM and rotator cuff healing did not significantly differ among the groups (all n.s.). CONCLUSIONS: No significant differences were found in the clinical and anatomical outcomes according to the type and dose of the anti-adhesive agents subacromially injected after rotator cuff repair. LEVEL OF EVIDENCE: III.

Superior capsular reconstruction using hybrid graft for irreparable massive rotator cuff tear.

PURPOSE: To evaluate the clinical and radiological outcomes of arthroscopic superior capsular reconstruction (SCR) using hybrid grafts composed of tensor fascia lata autografts and human dermal allografts. METHODS: This study included 30 patients with chronic irreparable posterosuperior rotator cuff tears (RCTs) who underwent arthroscopic SCR using a hybrid graft composed of tensor fascia lata autograft and human dermal allograft. Clinical outcomes were evaluated using the pain visual analogue scale score, shoulder range of motion, American Shoulder and Elbow Surgeons score, constant score, University of California-Los Angeles score, and simple shoulder test score preoperatively and at least 2 years after surgery. Radiographic analysis included the Hamada classification grade, acromiohumeral distance (AHD), and graft integrity at 2 years after surgery. RESULTS: All patients exhibited significant clinical improvement in all functional outcome measurements, except external rotation (all P < 0.05). The number of patients who exhibited pseudoparalysis decreased from 7 (23.3%) to 2 (6.7%) postoperatively. Complications were not observed. Radiologically, the mean postoperative AHD increased significantly from 6.9 ± 1.6 cm to 8.8 ± 2.1 cm at 2 years postoperatively (P < 0.001). Twenty five out of the 30 (83.3%) patients showed successful graft healing, and all healing failures occurred on the humeral side. The differences between the healed-graft and failed-graft groups were significantly lower graft thickness (P = 0.001) and smaller AHD (P < 0.001) in the failed-graft group. Every functional outcome scores were not statistically different between healed-graft and failed-graft groups. CONCLUSIONS: An arthroscopic SCR technique using a hybrid graft consisting of a tensor fascia lata autograft and human dermal allograft showed satisfactory clinical outcomes in patients with irreparable RCTs. LEVEL OF EVIDENCE: IV.

Improvement in scapular dyskinesis after rotator cuff repair and subacromial decompression.

PURPOSE: To investigate the incidence of scapular dyskinesis (SD) in patients with rotator cuff tears using pre- and postoperative 3D computed tomography, analyze the changes in scapular kinematics that occur after arthroscopic rotator cuff repair, and identify the contributing clinical factors. METHODS: Thirty-five patients (mean age, 62.5 ± 8.4 years) were included. Four scapular angles (upward rotation, internal rotation, protraction, and posterior tilt) were measured. The patients were categorized into three pre-existing SD types according to the difference in measured scapular angles between the affected and unaffected sides (type 1 SD, posterior tilt angle difference < - 5°; type 2 SD, internal rotation angle difference > 5°; and type 3 SD, upward rotation angle difference > 5°). The prevalence, factors influencing SD, and outcomes were compared between the improved and sustained SD groups. RESULTS: Twenty three of the 35 patients (65.7%) with rotator cuff tears had SD (type 1, 11; type 2, six; type 3, six). Of the 23 preoperative SD patients, 12 (52.1%) showed improved SD postoperatively. Most of the patients with improved SD (9/12) had type 1 SD (p = 0.021) and a significantly improved posterior tilt angle (p = 0.043). The improvement in SD was correlated with a higher range of motion of forward flexion and higher Constant scores (all p < 0.05). No healing failure occurred in the improved SD group (p = 0.037). CONCLUSION: The prevalence of SD was high in patients with degenerative rotator cuff tears. More than half of the SD cases, especially type 1 SD, improved postoperatively. SD recovery correlated with better function and successful rotator cuff healing. LEVEL OF EVIDENCE: IV.

Clinical outcome of rotator cuff repair in patients with mild to moderate glenohumeral osteoarthritis.

PURPOSE: Osteoarthritis (OA) in the glenohumeral joint is a concomitant lesion with rotator cuff tear that commonly occurs in older patients. The authors aimed to evaluate the effect of associated OA on the treatment outcome of rotator cuff repair. METHODS: A total of three hundred and forty-eight patients who underwent full-thickness arthroscopic rotator cuff repair were retrospectively reviewed, and the data were prospectively collected. The severity of OA was evaluated using the Samilson and Prieto method preoperatively and the Outerbridge classification intraoperatively. The patients were divided into the small-to-medium group and large-to-massive group according to rotator cuff tear size and were evaluated for presence or absence of OA. The postoperative clinical outcomes were assessed using the visual analog scale for pain, simple shoulder test (SST), University of California-Los Angeles, Constant, and American Shoulder and Elbow Surgeons (ASES) scoring systems at baseline and at final follow-up. RESULTS: Forty-five patients were diagnosed with glenohumeral OA (12.9%). Overall, no significant differences were observed in demographic and baseline data between the two groups according to the presence or absence of OA. The clinical symptoms of both groups significantly improved at the final follow-up. At the final follow-up, no significant differences were found in the VAS for pain, SST, UCLA, Constant, and ASES scores between the two groups. In the large-to-massive tear group, patients with OA had significantly inferior clinical results compared with those without OA. CONCLUSION: The clinical outcome scores improved after rotator cuff repair regardless of the presence of concomitant OA. However, glenohumeral OA should be considered as a potential negative prognostic factor in patients with large-to-massive rotator cuff tears. LEVEL OF EVIDENCE: III.

Does strength deficit correlate with shoulder function in patients with rotator cuff tears? Characteristics of massive tears.

BACKGROUND: The correlation between shoulder strength deficits and function in rotator cuff tears remains uncertain. This study aimed to determine the correlation between shoulder strength deficits and shoulder function evaluated by various clinical scoring systems. METHODS: A total of 262 patients (mean age, 59.67 years [standard deviation, 8.06 years]) who underwent full-thickness rotator cuff repair were included. Patients in group I (n = 188) had small to large rotator cuff tears, whereas those in group II (n = 74) had massive rotator cuff tears. Demographic factors, isokinetic test results, and shoulder function evaluated using various scoring systems were obtained. Correlation differences according to severity of the rotator cuff tear were evaluated. RESULTS: We found weak correlations between shoulder strength deficits (peak torque and total work) and clinical outcomes in patients with rotator cuff tears (r = -0.288). For patients in group I (nonmassive tears), we found a weaker correlation (r = -0.242) according to the tear pattern. However, shoulder strength deficits in group II patients (massive tears) were strongly correlated with American Shoulder and Elbow Surgeons (r = -0.598), Constant (r = -0.582), and Short Form 36 (r = -0.511) scores, especially regarding internal rotator strength deficits. CONCLUSIONS: Shoulder strength deficits measured via isokinetic testing and shoulder function were weakly correlated in patients with rotator cuff tears. However, shoulder strength deficits in patients with massive tears considerably worsened shoulder function and systemic disability, but not regional disability. In particular, internal rotator strength deficits were strongly correlated with poor shoulder function.

Automated detection and classification of the proximal humerus fracture by using deep learning algorithm.

Background and purpose - We aimed to evaluate the ability of artificial intelligence (a deep learning algorithm) to detect and classify proximal humerus fractures using plain anteroposterior shoulder radiographs. Patients and methods - 1,891 images (1 image per person) of normal shoulders (n = 515) and 4 proximal humerus fracture types (greater tuberosity, 346; surgical neck, 514; 3-part, 269; 4-part, 247) classified by 3 specialists were evaluated. We trained a deep convolutional neural network (CNN) after augmentation of a training dataset. The ability of the CNN, as measured by top-1 accuracy, area under receiver operating characteristics curve (AUC), sensitivity/specificity, and Youden index, in comparison with humans (28 general physicians, 11 general orthopedists, and 19 orthopedists specialized in the shoulder) to detect and classify proximal humerus fractures was evaluated. Results - The CNN showed a high performance of 96% top-1 accuracy, 1.00 AUC, 0.99/0.97 sensitivity/specificity, and 0.97 Youden index for distinguishing normal shoulders from proximal humerus fractures. In addition, the CNN showed promising results with 65-86% top-1 accuracy, 0.90-0.98 AUC, 0.88/0.83-0.97/0.94 sensitivity/specificity, and 0.71-0.90 Youden index for classifying fracture type. When compared with the human groups, the CNN showed superior performance to that of general physicians and orthopedists, similar performance to orthopedists specialized in the shoulder, and the superior performance of the CNN was more marked in complex 3- and 4-part fractures. Interpretation - The use of artificial intelligence can accurately detect and classify proximal humerus fractures on plain shoulder AP radiographs. Further studies are necessary to determine the feasibility of applying artificial intelligence in the clinic and whether its use could improve care and outcomes compared with current orthopedic assessments.

Altered Gene and Protein Expressions in Torn Rotator Cuff Tendon Tissues in Diabetic Patients.

PURPOSE: To analyze and compare the gene and protein expression characteristics in torn rotator cuff tendon tissues between diabetic and nondiabetic patients. METHODS: This was a pilot study. Twelve samples of rotator cuff tendon tissue from diabetic patients (mean age, 62.3 ± 9.9 years) and 12 age- and sex-matched nondiabetic tendon tissues (62.3 ± 9.9 years) were acquired from the torn tendon end of medium rotator cuff tears during arthroscopic surgery, after applying the same inclusion and exclusion criteria. Expressions of various genes of interest, including collagens I and III, matrix metalloprotease (MMP)-2, MMP-3, MMP-9, MMP-13, interleukin (IL)-1, IL-6, insulin-like growth factor-1, vascular endothelial growth factor, tenomodulin, tumor necrosis factor-α, and p53, were analyzed with real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). In addition, immunohistochemistry and western blot assay were performed for the genes that revealed significantly different expressions in real-time qRT-PCR between groups. RESULTS: Gene expression levels of MMP-9, MMP-13, IL-6, and tenomodulin were significantly higher in the diabetic than in the nondiabetic group by real-time qRT-PCR analyses (P = .011, .004, .009, and .010, respectively). The density of cells expressing MMP-9 and IL-6 was significantly increased in the torn tendons of the diabetic patients on immunohistochemical analysis, and the density of MMP-9 and IL-6 protein expressions was significantly higher in the diabetic group on western blot (P = .018 and .044, respectively). CONCLUSIONS: Diabetic torn cuff tendon tissues showed MMP-9 and IL-6 overexpressions compared with controls. CLINICAL RELEVANCE: The overexpressions of MMP-9 and IL-6 may be one of the explanations for the high healing failure rate after rotator cuff repair in the diabetic patients.

Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation.

PURPOSE: Acromioclavicular (AC) joint dislocation is a common sports injury. Hook plate fixation is currently widely used to treat this injury, as it can promote the natural healing of the ligament with good clinical outcomes. However, subacromial erosion and impingement are frequently observed post-operatively. It was hypothesized that the morphology and the contact characteristics between the hook portion and the acromion are the main causes of complications after hook plate fixation with the currently available commercial designs. METHODS: Three-dimensional reconstructed models of the AC joint obtained from the computed tomographic scans of 23 male and 23 female patients (mean age, 61.1 ± 6.3 years) were evaluated, and multiple anatomical parameters were measured. For the subacromial positioning of the hook plate, an actual hook plate (Synthes Inc., West Chester, PA, USA) was scanned, and the contact between the hook plate and the acromion was estimated. RESULTS: The thicknesses of the acromion and distal clavicle were 9.7 ± 1.5 mm (10.7 mm in men; 8.6 mm in women) and 11.3 ± 1.6 mm (11.6 mm in men; 10.0 mm in women), respectively. The width of the acromion was 28.5 ± 3.6 mm. The mean inclination angle between the hook plate and the acromion was 29.3° ± 9.7° (27.9° in men; 30.6° in women). The hook plate made a point contact with the acromion at 9.2 ± 3.3 mm (31.5 %) from the lateral end of the acromion. CONCLUSIONS: The results revealed that the hook made a pinpoint contact with the undersurface of the acromion, and this might explain why complications commonly occur after hook plate fixation. The force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space.

Correlations of magnetic resonance imaging findings with clinical symptom severity and prognosis of frozen shoulder.

PURPOSE: To evaluate the correlation between indirect magnetic resonance (MR) arthrographic imaging findings and the clinical symptoms and prognosis of patients with frozen shoulder. METHODS: Indirect MR arthrography was performed for 52 patients with primary frozen shoulder (mean age 55.1 ± 9.0 years) and 52 individuals without frozen shoulder (mean age 53.1 ± 10.7 years); capsular thickening and enhancement of the axillary recess as well as soft tissue thickening of the rotator interval were evaluated. Clinical symptom severity was assessed using the Visual Analogue Scale for Pain (VAS Pain), simple shoulder test (SST), Constant score, American Shoulder and Elbow Surgeons (ASES) score, and range of motion (ROM). At 6-month follow-up, we evaluated whether MR arthrography findings correlated with the clinical symptoms and prognosis. RESULTS: Capsular thickening and enhancement of the axillary recess as well as soft tissue thickening of the rotator interval were significantly greater in the patient group than in the controls (p < 0.001). Capsular thickening of the axillary recess did not correlate with clinical symptoms or ROM (n.s.); however, capsular enhancement correlated with clinical symptom severity according to VAS Pain (p = 0.005), SST (p = 0.046), and ASES scores (p = 0.009). Soft tissue thickening of the rotator interval did not correlate with clinical symptom severity, but was associated with external rotation limitation (p = 0.002). However, none of the parameters correlated with clinical symptoms at 6-month follow-up. CONCLUSIONS: Indirect MR arthrography provided ancillary findings, especially with capsular enhancement, for evaluating clinical symptom severity of frozen shoulder, but did not reflect the prognosis. MR findings in frozen shoulder should not replace clinical judgments regarding further prognosis and treatment decisions. LEVEL OF EVIDENCE: IV.

Intra-articular injection, subacromial injection, and hydrodilatation for primary frozen shoulder: a randomized clinical trial.

BACKGROUND: The aim of this prospective randomized study was to compare the efficacy of 3 injection methods, intra-articular injection, subacromial injection, and hydrodilatation (HD), in the treatment of primary frozen shoulder. METHODS: Patients with primary frozen shoulder were randomized to undergo intra-articular injection (n = 29), subacromial injection (n = 29), or HD (n = 28). Evaluations using a visual analog scale for pain, Simple Shoulder Test, Constant score, and passive range of shoulder motion were completed before treatment and 1 month, 3 months, and 6 months after treatment. RESULTS: Among the 3 injection methods for primary frozen shoulder, HD resulted in a greater range of motion in forward flexion and external rotation, a lower visual analog scale score for pain after 1 month, and better outcomes for all functional scores after 1 month and 3 months of follow-up. However, there were no significant differences in any clinical outcomes among the 3 groups in the final follow-up at 6 months. CONCLUSIONS: Although HD yielded more rapid improvement, the 3 injection methods for primary frozen shoulder resulted in similar clinical improvement in the final follow-up at 6 months.

Rotator cuff tear and sarcopenia: are these related?

BACKGROUND: Sarcopenia is the loss of muscle mass and consequent loss of muscle function with aging. Its prevalence among the general population is 12% to 30% in those aged >60 years. We evaluated (1) the difference in the prevalence of sarcopenia between patients with rotator cuff tear and controls and (2) the sarcopenia severity according to the size of the rotator cuff tear. METHODS: Group 1 included 48 consecutive patients with chronic symptomatic full-thickness rotator cuff tears (mean age, 60.1 ± 6.5 years; range, 46-76 years), and group 2 included 48 age- and sex-matched patients. The sarcopenic index was evaluated by using the grip strength of the asymptomatic contralateral side and the skeletal muscle mass. RESULTS: No significant differences were found in the baseline data and demographic factors between the groups. The sarcopenic index was significantly inferior in the rotator cuff tear group than in the age- and sex-matched control groups (P = .041, .007, and .05, respectively). Patients with large to massive tears had a significantly inferior sarcopenic index than those with small and medium tears. CONCLUSION: The results showed that sarcopenia was more severe in patients with a chronic symptomatic full-thickness rotator cuff tear than in the age- and sex-matched control population and was correlated with the size of the tear, with the numbers available. Despite the individual variance in the underlying medical condition and physical activities, this study suggests that clinicians should consider the sarcopenic condition of patients with a rotator cuff tear, especially in elderly patients with large to massive tears.

Prognostic Factors of Arthroscopic Extensor Carpi Radialis Brevis Release for Lateral Epicondylitis.

PURPOSE: The purpose of this study was to analyze factors affecting the treatment outcomes and prognoses of arthroscopic debridement for refractory lateral epicondylitis. METHODS: We included 45 patients who had undergone arthroscopic extensor carpi radialis brevis release for chronic refractory lateral epicondylitis between October 2008 and December 2012. Demographic data, magnetic resonance imaging studies, and arthroscopic findings were examined and analyzed. RESULTS: The mean age of the enrolled patients (23 men and 22 women) was 45.9 ± 7.8 years, and the mean follow-up duration was 26.9 ± 9.0 months. All the patients showed significant clinical improvement on all parameters assessed using the visual analog scale (6.9 preoperatively to 0.9 postoperatively), the Upper Extremity Functional Scale (34.8 to 66.7), and the Mayo Elbow Score (63.5 to 92.3) (P < .05). There were no reports of serious surgical complications. At final follow-up, 37 patients (82.2%) were satisfied with their outcomes whereas 8 patients (17.8%) were dissatisfied. In terms of demographic factors, female sex was significantly different between the 2 groups. On preoperative magnetic resonance imaging, 7 patients in the satisfied group (18.9%) had a definite tendon lesion (grade III defect, ≥6 mm) whereas 6 patients in the dissatisfied group (75%) had a grade III defect (P = .016). CONCLUSIONS: Overall, clinical outcome scores showed improvement after arthroscopic extensor carpi radialis brevis release for refractory lateral epicondylitis. However, preoperative tendon status and sex were associated with dissatisfaction and poor postoperative outcomes after the arthroscopic release procedure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Artificial intelligence- and computer-assisted navigation for shoulder surgery.

Background: Over the last few decades, shoulder surgery has undergone rapid advancements, with ongoing exploration and the development of innovative technological approaches. In the coming years, technologies such as robot-assisted surgeries, virtual reality, artificial intelligence, patient-specific instrumentation, and different innovative perioperative and preoperative planning tools will continue to fuel a revolution in the medical field, thereby pushing it toward new frontiers and unprecedented advancements. In relation to this, shoulder surgery will experience significant breakthroughs. Main body: Recent advancements and technological innovations in the field were comprehensively analyzed. We aimed to provide a detailed overview of the current landscape, emphasizing the roles of technologies. Computer-assisted surgery utilizing robotic- or image-guided technologies is widely adopted in various orthopedic specialties. The most advanced components of computer-assisted surgery are navigation and robotic systems, with functions and applications that are continuously expanding. Surgical navigation requires a visual system that presents real-time positional data on surgical instruments or implants in relation to the target bone, displayed on a computer monitor. There are three primary categories of surgical planning that utilize navigation systems. The initial category involves volumetric images, such as ultrasound echogram, computed tomography, and magnetic resonance images. The second type is based on intraoperative fluoroscopic images, and the third type incorporates kinetic information about joints or morphometric data about the target bones acquired intraoperatively. Conclusion: The rapid integration of artificial intelligence and deep learning into the medical domain has a significant and transformative influence. Numerous studies utilizing deep learning-based diagnostics in orthopedics have remarkable achievements and performance.

Pure varus posteromedial rotatory instability of the elbow: Radiographic findings, treatment, and outcomes.

INTRODUCTION: Although varus posteromedial rotatory instability (VPMRI) is a subtle elbow injury that involves anteromedial coronoid facet (AMCF) fracture and ligamentous injuries, treatment options and outcomes of VPMRI remains controversial. The aim of this study was to investigate radiographic findings, treatments, and outcomes of a large series of VPMRI. METHODS: We retrospectively reviewed 91 pure VPMRI cases with AMCF fracture (O'Driscoll classification anteromedial type) which were treated at 6 hospitals. Clinical and radiographic outcomes were investigated with a mean follow-up period of 46.8 months using the Mayo elbow performance score (MEPS), and the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) score, and serial plain radiographs. RESULTS: In AMCF fracture, there were 4 cases of subtype 1, 67 cases of subtype 2, and 20 cases of subtype 3. On MRI, complete tears of lateral collateral ligament and medial collateral ligament were observed in 83.1 % (59/71 cases) and 33.8 % (24/71 cases). Operative treatment was performed in 68 cases (74.7 %) including both side fixation in 40 cases (58.8 %), medial side fixation only in 17 cases (25.0 %), and lateral side fixation only in 11 cases (16.2 %). Nonoperative treatment was performed in 23 cases (25.3 %). The mean final MEPS and Quick-DASH scores were 93.7 and 7.9. The overall complication and reoperation rates were 22.0 % and 15.4 %. No significant differences regarding final clinical scores and range of motions were observed between the operative group and the nonoperative group, but significant differences were observed regarding number (p = 0.019) and displacement (p = 0.002) of coronoid fragment, and complication rate (p < 0.001) between the two groups. CONCLUSION: Depending on the pattern of coronoid fragment and the degree of ligamentous injuries, operative treatment of unstable VPMRI using various fixation techniques including coronoid fixation and ligament repair yielded satisfactory final clinical outcomes. However, surgeons should be aware of the high complication and reoperation rates after operative treatment. Stable VPMRI with AMCF fracture involving minimal displacement or small number of fragments can be treated nonoperatively.

Reconstruction of Bilateral Chronic Triceps Brachii Tendon Disruption Using a Suture-Mediated Anatomic Footprint Repair in a Dog.

A 2-year-old, intact female Pomeranian presented with bilateral forelimb lameness, characterized by the olecranon making contact with the ground. The patient experienced two separate incidents of falling, occurring four and three weeks before admission, respectively. Following each episode, non-weight-bearing lameness was initially observed in the left forelimb, followed by the development of crouch gait. Based on the physical examination, radiographic, and ultrasonographic findings, bilateral triceps brachii tendon disruption was diagnosed. Intraoperatively, excessive granulation tissue at the distal end of the tendon was excised. The footprint region of each triceps brachii tendon was decorticated with a high-speed burr until bleeding was observed. The triceps brachii tendon was reattached to completely cover its footprint on the olecranon using the Krackow suture technique. This method involves anchoring the suture through bone tunnels in the ulna. Trans-articular external skeletal fixation was applied to both forelimbs to immobile and stabilize the elbow joints for nine weeks. Subsequently, the dog gradually increased its walking activities while on a leash over a six-week period. At the three-year follow-up, the patient exhibited improved forelimb function and maintained a normal gait without signs of lameness. Suture-mediated anatomic footprint repair proved useful in this single case and may be an effective surgical alternative for the management of chronic triceps brachii tendon disruption in dogs.

Diagnostic value of four clinical tests for the evaluation of subscapularis integrity.

HYPOTHESIS: The lift-off, internal rotation lag sign, belly-press, and bear-hug tests are widely used to evaluate the integrity of the subscapularis. We hypothesized that these tests might reflect different types of subscapularis tears and sought to ascertain whether these tests accurately determine the severity of the internal rotation strength deficit and fatty degeneration. METHODS: Isokinetic testing and the 4 clinical tests were used preoperatively to evaluate 312 patients who had undergone arthroscopic rotator cuff surgery. Of these, 37 patients had a full-thickness subscapularis tear, 96 had a partial-thickness tear, and 179 had no tear. RESULTS: For differentiating any tears from an intact subscapularis, the most sensitive test was the belly-press test (27.8%), and the most specific test was the lift-off test (100%). For differentiating a full-thickness tear from a partial tear, the most sensitive test was the belly-press test (56.8%), and the most specific was the lift-off test (96.9%). A positive lift-off test also most reflected loss of internal rotation strength (mean, 72.2%; 95% confidence interval, 61.9-82.5), followed by the internal rotation lag sign (55.1%; 44.2-66.1) and the belly-press test (45.9%; 36.4-54.4). CONCLUSIONS: A positive lift-off test was highly specific for the detection of a full-thickness subscapularis tear and to reflect severe fatty degeneration. The lift-off, internal rotation lag sign, belly-press, and bear-hug tests sequentially predict internal rotation strength deficit and provide discrimination of internal rotation strength impairment.

Minimally invasive plate osteosynthesis for humeral shaft fracture: a reproducible technique with the assistance of an external fixator.

BACKGROUND: Minimally invasive plate osteosynthesis (MIPO) has become a popular option for treatment of humeral shaft fractures. However, indirect reduction might risk unpromising results, with mal-alignment/mal-union or nonunion. The purpose of this study was to describe a reproducible MIPO technique that used an external fixator during the procedure as a tool for reduction and maintenance, and to assess the outcomes in patients with humeral shaft fracture. METHODS: Of 31 consecutive cases of humeral shaft fracture in 30 patients, 29 were included in this study. There were seven simple (type A) and 22 comminuted (type B or C) fractures. After the insertion of one Schanz pin on each proximal and distal humerus, a provisional reduction was achieved by connecting the pins with a monolateral external fixator. The MIPO procedure was then performed over the anterior aspect of the humerus. To evaluate the efficacy of the provisional reduction by external fixator, coronal and sagittal alignments were assessed. We also assessed bony and functional results, including complications, from this technique. RESULTS: There was no case of mal-union >10°, and mean angulation was 1.3° (range 0°-9°) in the coronal plane and 1.2° (range 0°-8°) in the sagittal plane. Twenty-eight of 29 fractures were united, including three delayed unions, with a mean union time of 19.1 weeks (range 12.3-38.4 weeks) and a mean follow-up of 20.8 months (range 13.5-31.0 months). There was one hypertrophic nonunion that healed after fixing with two additional screws. Except one patient with associated injury in the elbow, all patients recovered to pre-injury joint motion. There were two cases of postoperative radial nerve palsy that both recovered completely. We attributed them to manipulation, and not to the Schanz pins or plate fixation. CONCLUSIONS: Surgical treatment of humeral shaft fractures with external fixator-assisted reduction and MIPO resulted in excellent reductions and high union rates.

Metformin increases the expression of proinflammatory cytokines and inhibits supraspinatus fatty infiltration.

BACKGROUND: After a rotator cuff (RC) tendon tear, the supraspinatus (SS) inflammatory response induces fatty infiltration (FI). Metformin has the effect of regulating the initial inflammatory response of atrophic muscles. Therefore, this study aimed to investigate the effect of metformin use on modulating the expression of proinflammatory cytokines and SS FI in an acute RC tear rat model. METHODS: This study used 26 male Sprague-Dawley rats. Animals were randomly divided into two groups: The metformin group received metformin for 5 days after cutting the RC tendon, and the control group was administered only with saline after cutting the tendon. Metformin 50 mg/kg was intraperitoneally injected for 5 days. Three rats in each group were sacrificed 5 days after SS tendon rupture surgery, and 10 rats in each group were sacrificed 14 days after surgery. The SS was sampled 5 days after SS tendon tear surgery, and the expression of proinflammatory cytokines was measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). On day 14 after sampling, histological analysis of the SS was performed using hematoxylin and eosin, Masson's trichrome, and picrosirius red staining. RESULTS: On day 5 of surgery, the expression values of interferon gamma (increased 7.2-fold, P < .01), tumor necrosis factor alpha (increased 13-fold, P < .05), interleukin-1ß (increased 4.7-fold, P < .001), and interleukin-6 (increased 4.6-fold, P < .01) increased significantly in the metformin group compared with those in the control group. As a result of Oil Red O staining, SS FI was significantly suppressed in the metformin group compared with that in the control group (metformin group, 305 ± 50.3 µm2, P < .001; control group, 3136 ± 662.8 µm2, P < .001). In addition, the SS volume of the metformin group was not reduced compared with those of the control group, and the morphology and structure of the SS were better preserved. CONCLUSIONS: The results of this study revealed that metformin can increase the expression of proinflammatory cytokines and suppress SS fat infiltration in delayed sutures.