STING contributes to trauma-induced heterotopic ossification through NLRP3-dependent macrophage pyroptosis.

Trauma-induced heterotopic ossification (HO) is featured by aberrant bone formation at extra-skeletal site. STING is a master adaptor protein linking cellular damage to immune responses, while its role in HO remains elusive. A murine burn/tenotomy model was used to mimic trauma-induced HO in vivo. We demonstrated elevated STING expression in macrophages in inflammatory stage after burn/tenotomy, and STING inhibition significantly alleviated HO formation. Activated NLRP3-dependent macrophage pyroptosis was also found in inflammatory stage after burn/tenotomy. Either STING or NLRP3 suppression reduced mature HO by weakening macrophage pyroptotic inflammation, while protective effects of STING were abolished by NLRP3 overexpression. Further, in vitro, we also found a prominent STING level in pyroptotic BMDMs. STING suppression relieved macrophage pyroptotic inflammation, while abolished by NLRP3 overexpression. Our results reveal that STING poses regulatory effects on trauma-induced HO formation, via modulating NLRP3-dependent macrophage pyroptosis. Targeting STING-NLRP3 axis represents an attractive approach for trauma-induced HO prevention.

Bilateral triceps tendon approach is flexible and efficient in the treatment of type C distal humerus fractures.

PURPOSE: The purpose of this study was to assess and compare elbow range of motion, triceps extension strength and functional results of type C (AO/OTA) distal humerus fractures treated with bilateral triceps tendon (BTT) approach and olecranon osteotomy (OO). At the same time, we are also trying to know whether BTT approach can provide sufficient vision for comminuted intra-articular fractures of the distal humerus, and whether it is convenient to convert to the treatment to total elbow arthroplasty (TEA) or OO. METHODS: Patients treated with OO and BTT approaches for type C distal humerus fractures between July 2014 and December 2017 were retrospectively reviewed. Inclusion criteria include: (1) patients' age were more than 18 years old, (2) follow-up was no less than 6 months, and (3) patients were diagnosed with type C fractures (based on the AO/OTA classification). Exclusion criteria include: (1) open fractures (Gustillo type 2 or type 3), (2) treated by other approaches, and (3) presented with combined injuries of ipsilateral upper extremities, such as ulnar nerve. Elbow range of motion and triceps extension strength testing were completely valuated, when the fractures had healed. Assessment of functional results using the Mayo elbow performance score and complications were conducted in final follow-up. The data were compared using the two tailed Student's t-test. All data were presented as mean ± standard deviation. RESULTS: Eighty-six patients of type C distal humerus fractures, treated by OO and BTT approach were retrospectively reviewed between July 2014 and December 2017. Fifty-five distal humerus fractures (23 males and 32 females, mean age 52.7 years) treated by BTT approach or OO were included in this study. There were 10 fractures of type C1, 16 type C2 and 29 type C3 according to the AO/OTA classification. Patients were divided into two surgical approach groups chosen by the operators: BTT group (28 patients) and OO group (27 patients). And the mean follow-up time of all patients was 15.6 months (range, 6-36 months). Three cases in BTT group were converted to TEA, and one converted to OO. Only one case in BTT group presented poor articular reduction with a step more than 2 mm. There were not significantly different in functional outcomes according to the Mayo elbow performance score, operation time and extension flexion motion are values between BTT group and OO group (p > 0.05). Complications and reoperation rate were also similar in the two groups. Triceps manual muscle testing were no significant difference in the two groups, even subdivided in elder patients (aged >60 years old). CONCLUSION: BTT is a safe approach to achieve similar functional result comparing with OO. BTT were not suitable for every case with severe comminuted pattern, but it avoids the potential complications related to OO, and has no complications concerning with triceps tendon. It is convenient for open reduction internal fixation and flexible to be converted to OO, as well as available to be converted to TEA in elder patients.

A new pathologic classification for elbow stiffness based on our experience in 216 patients.

BACKGROUND: Elbow stiffness commonly causes functional impairment and upper-limb disability. This study aimed to develop a new pathologic classification to further understand and standardize elbow arthrolysis from a new perspective, as well as to determine clinical outcomes. METHODS: Extension-flexion dysfunction was classified into 4 types: EFI, tethers alone; EFII, tethers with blocks; EFIII, articular malformation; and EFIV, bony ankylosis. Forearm rotation dysfunction was classified into 3 types: FRI, contracture alone; FRII, radial head malunion or nonunion; and FRIII, proximal radioulnar bony ankylosis. A total of 216 patients with elbow stiffness were prospectively included and categorized preoperatively. All surgical procedures were performed by the same chief surgeon; different types underwent specific procedures. Patient data, elbow motion, and functional scores were analyzed. RESULTS: Mean range of motion (ROM) increased from 40° preoperatively to 118° at final follow-up; 88% of patients regained ROM of 100° or greater. The forearm rotation arc (FRA) with forearm rotation dysfunction increased from a preoperative mean of 76° to 128°; 82% of patients regained an FRA of 100° or greater. The mean Mayo Elbow Performance Index (MEPI) increased from 63 to 91 points; the proportion of patients with good or excellent results was 95%. EFI patients had the best ROM (129°) and MEPI (93 points) and EFIV patients achieved the most-changed ROM (116°), whereas EFIII patients had the worst ROM (104°) and MEPI (84 points) and the least-changed ROM (64°). The FRA was best in FRI patients (142°), followed by FRII patients (118°), and worst in FRIII patients (82°); in contrast, the changed FRA was greatest in FRIII patients (82°), followed by FRII patients (64°), and least in FRI patients (37°). CONCLUSION: This study suggests that the proposed pathologic classification provides a new perspective on the understanding and standardization of elbow arthrolysis, providing satisfactory clinical outcomes.

Bifocal osteosynthesis to treat radial shortening deformity with dislocation of the inferior radioulnar joint.

BACKGROUND: Several methods have been reported to correct deformity and shortening of the distal radius. However, the results are not entirely satisfactory. The results of bifocal osteosynthesis were retrospectively analyzed in this study. METHODS: Eight patients treated with bifocal osteosynthesis were evaluated retrospectively. Pre-operative and post-operative clinical and radiographic examinations were performed. Subjective symptoms and objective joint function were assessed. Radiographic data of the extent of radial lengthening and distal radial articular angle were collected. RESULTS: The mean follow-up period was 46 months (37-68 months). Satisfactory wrist appearance and radial lengthening was achieved in all patients. All patients were satisfied with the wrist appearance and willing to undergo the same treatment again. The range of motion (ROM) of the forearm and wrist was significantly improved. Pin-track infections occurred in two patients, for which they received wound care and oral antibiotics. Complications such as fixation device failure, tendon rupture, fracture of regenerated bone or nerve impairment did not occur. The duration of lengthening depended on the shortening of the radius. Delayed union in the docking site was observed in two patients and union was achieved after bone grafting. CONCLUSIONS: Bifocal osteosynthesis using the Ilizarov method provides a useful method for correction of radial shortening deformity with dislocation of the inferior radioulnar joint. Despite the fact that we did not validate pre-and post-operation functional outcome scores, all patients were satisfied with the wrist appearance and function.

Humeral lengthening and proximal deformity correction with monorail external fixator in young adults.

PURPOSE: Several humeral lengthening or simultaneous deformity corrections through one osteotomy using various external fixators were reported, while literature regarding correction of shortening and proximal varus deformity is scarce. This retrospective clinical study evaluated the results of preforming an acute correction and delayed lengthening in young adults through two osteotomies using monorail external fixator. METHODS: We report seven patients with various pathologies who underwent humeral proximal deformity correction and lengthening between 2009 and 2015. Pre-operative and post-operative clinical and radiographic data were collected. The mean follow-up time was 33.4 months (25-46 months). RESULTS: The humeral neck-shaft angle improved from 97.9° (85-110°) to 138.6° (135-145°). The magnitude of lengthening achieved was average 7.6 cm (range, 6-10 cm) at an average healing index of lengthening of 30.2 days/cm (range, 27.7-35.4 days/cm). There was a significant increase in range of shoulder abduction, and active abduction improved from pre-operative 136.4° (range, 95-160°) to post-operative 166.4° (range, 150-180°). The DASH score improved significance from 23.29 ± 8.36 to 6.57 ± 3.65 (t = 4.848; p < 0.001). CONCLUSION: Acute deformity correction and gradual lengthening with the monorail external fixator can be used for humeral shortening and proximal varus angular deformity. Functional improvement is expected after surgery and post-operative therapy.

Ulnar neuritis after open elbow arthrolysis combined with ulnar nerve subcutaneous transposition for post-traumatic elbow stiffness: outcome and risk factors.

BACKGROUND: Ulnar neuritis (UN) is a common complication of open elbow arthrolysis for elbow stiffness. The purpose of this study was to evaluate the outcome of subcutaneous anterior transposition of the ulnar nerve during open elbow arthrolysis and to describe the risk factors for UN. METHODS: We retrospectively studied 260 patients with post-traumatic elbow stiffness who underwent routine ulnar nerve transposition during open elbow arthrolysis. Patient demographics, clinical characteristics, and incidence and reoperation rate of UN were recorded. UN was defined as new-onset ulnar nerve symptoms and no relief or worsening of pre-existing ulnar nerve symptoms during the period of postoperative rehabilitation. Factors affecting the development of UN were analyzed by univariate and multivariate analyses. RESULTS: A total of 9.2% of the patients had UN, 25% of whom required reoperation for progressive neuropathy. The Dellon grade of patients associated with UN at last follow-up improved significantly compared with that preoperatively. The mean arc of motion in patients with UN decreased during follow-up in a time-dependent manner. Univariate analysis showed that male sex, limited preoperative flexion and arc of motion, preoperative heterotopic ossification (HO), and preoperative ulnar nerve symptoms were significantly associated with the development of UN. Multivariate regression analysis revealed that preoperative HO was the only independent risk factor for the development of UN. CONCLUSIONS: UN is still an important complication, although ulnar nerve subcutaneous transposition was performed during open arthrolysis for post-traumatic elbow stiffness. Identified risk factors for UN, especially preoperative HO, should be taken into consideration before surgery.

The efficacy of celecoxib in preventing heterotopic ossification recurrence after open arthrolysis for post-traumatic elbow stiffness in adults.

BACKGROUND: Heterotopic ossification (HO) recurrence after joint surgery is always a disturbing problem for patients and surgeons. Our study was performed to assess the efficacy and safety of celecoxib in preventing the recurrence of HO after open arthrolysis for post-traumatic elbow stiffness. METHODS: We retrospectively studied 152 patients with stiff elbows caused by post-traumatic HO. After surgery, 77 patients received celecoxib (200 mg once daily) for 28 days, whereas 75 did not. Radiographic evaluation was performed at 3, 6, and 9 months postoperatively. Univariate and multivariate analyses were performed to determine which factors affected HO recurrence. RESULTS: HO was both more common and more severe in the no-celecoxib group than in the celecoxib group at 3, 6, and 9 months after surgery. A significant difference was observed between the 2 groups in terms of postoperative extension (P = .030), flexion (P = .008), and pronation (P = .005); however, no significant difference in postoperative supination was noted (P = .622). Logistic regression analysis showed that taking celecoxib was the protective factor for HO recurrence, whereas overweight (body mass index > 25) and male gender were the risk factors. CONCLUSIONS: A short course of celecoxib aids in the prevention of HO recurrence after open arthrolysis for elbow stiffness in adults and could be an effective and safe option.

The time point in surgical excision of heterotopic ossification of post-traumatic stiff elbow: recommendation for early excision followed by early exercise.

BACKGROUND: Post-traumatic heterotopic ossification (HO) around the elbow may severely impair joint function. Although surgical excision is effective at restoring range of motion (ROM), traditional surgical treatment is postponed for at least 1 year to prevent recurrence, which leads to secondary contracture of the elbow. Because the optimal timing of resection is controversial, our study was performed to compare recurrence and elbow function between early and late excision in our patients to determine whether the delay is necessary. METHODS: We retrospectively reviewed 164 patients during a 4-year period. In the control group (112 patients), HO was excised at an average of 23.0 months after initial injury (range, 9-204 months); in the early excision group (52 patients), resection was performed at an average of 6.1 months (range, 3-8 months). HO recurrence was assessed by the Hastings classification system. Final ROM and Mayo Elbow Performance Scores were also evaluated. RESULTS: Recurrent HO was observed in 30 of 112 patients (26.8%) in the control group and 15 of 52 (28.9%) in early excision group. No significant difference in HO recurrence was found between the 2 groups (P = .942). Moreover, there were no notable differences regarding ROM, Mayo Elbow Performance Scores, and complications postoperatively. CONCLUSIONS: Early excision associated with early exercise is effective for the treatment of HO aiming at a low recurrence rate and satisfactory function. The conventional surgical delay of more than 1 year may be shortened.

Arthrolysis and delayed internal fixation combined with hinged external fixation for elbow stiffness associated with malunion or nonunion of capitellum fracture.

BACKGROUND: This study assessed outcomes after treatment of patients with capitellum fracture diagnosed >4 weeks after the trauma (delayed) who presented with stiff elbow. METHODS: We reviewed 7 patients with stiff elbows after delayed diagnosis of capitellum fractures between February 2007 and February 2012. They were treated with arthrolysis by twin incisions, late open reduction and internal fixation, and a hinged external fixator. According to the Bryan-Morrey-McKee classification, 3 patients had type I capitellum fractures and 4 patients had type IV. RESULTS: Mean follow-up was 28 months (range, 24-38 months). The mean delay from the initial trauma was 3.7 months. The flexion arc improved from a preoperative mean of 24° to a postoperative mean of 122°. The Mayo Elbow Performance Score increased from a mean of 56 points to 93 points. Anatomic fracture union occurred in all cases, and there was no secondary displacement. CONCLUSIONS: Arthrolysis, late internal fixation, and use of a hinged external fixator can solve problems associated with stiff elbow after delayed diagnosis of capitellum fracture. Combined use of these techniques may be a safe and effective treatment option.

Comparative study of radial head resection and prosthetic replacement in surgical release of stiff elbows.

PURPOSE: Elbow trauma can compromise the arc of elbow flexion and forearm rotation. This study aimed at comparing the outcomes of radial head resection and prosthetic replacement in the surgical release of post traumatic elbow stiffness and associated restriction in forearm rotation. METHODS: We retrospectively reviewed the data of patients who underwent open arthrolysis with radial head resection (n = 15; resection group) or radial head replacement (n = 19; replacement group). The pre- and postoperative measurements of the elbow range of motion (ROM) were recorded. Elbow function was evaluated by the Broberg and Morrey Evaluation System; the Mayo Elbow Performance Index (MEPI); and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. RESULTS: Over a mean follow-up duration of 22 months, the improvement in the arc of flexion and extension was 79° (range, 45-125°) and 82° (range, 10-110°), while that in the ROM for forearm rotation was 96° (range, 40-150°) and 102° (range, 15-150°) in the resection and replacement groups, respectively. There were no significant intergroup differences in the elbow ROM measured at the last follow up. The Broberg and Morrey, MEPI, and Dash scores in the two groups were comparable. CONCLUSIONS: Both resection and prosthetic replacement of the radial head with open arthrolysis of post traumatic elbow stiffness were feasible in treating the associated restriction of forearm rotation. We recommend that if the elbow is stable after complete release, radial head resection is preferable to prosthetic replacement because it is technically less demanding.

Stability of severely stiff elbows after complete open release: treatment by ligament repair with suture anchors and hinged external fixator.

BACKGROUND: Instability is a crucial issue in severe post-traumatic elbow stiffness during complete-release surgery. This study aimed to evaluate the efficacy of ligament repair using a suture anchor in the operative treatment of severely stiff elbows for which a hinged external fixator was indicated. METHODS: We retrospectively reviewed 46 cases of severely stiff elbows (flexion arc <60°) undergoing open release. During the operation, all 46 elbows were noted to have instability. Suture anchors were applied to restore the ligament if it was impossible to repair the ligament directly, and a hinged external fixator was simultaneously applied to protect the vulnerable ligament and facilitate rehabilitation. No allograft or autograft was used in any of our cases. The stability, arc of motion, Mayo Elbow Performance Score, ulnar nerve symptoms, and radiographs were evaluated. RESULTS: At a mean follow-up of 24.3 months, the postoperative Mayo Elbow Performance Score was 91 points, as compared with 63 points preoperatively. The mean flexion arc improved from 25° to 126°. Three patients presented with moderate elbow instability when the hinged external fixator was removed; however, all of them regained stability by the last follow-up. Furthermore, 7 cases of new-onset nerve palsy were noted; however, all of them resolved with conservative management. None of the patients required secondary surgery for any reason. CONCLUSIONS: Repair of an avulsed collateral ligament with suture anchors and hinged external fixation was effective in restoring functional mobility in patients with severe post-traumatic elbow stiffness after complete release. This could be an option for treating ankylosed, severely or very severely stiff elbows.

Arthrolysis combined with reconstruction for treatment of terrible triad injury with a poor outcome after surgical as well as conservative intervention.

INTRODUCTION: The treatment of terrible triad injury with a poor outcome after intervention has not been successful thus far. The purpose of this study was to evaluate the efficacy of arthrolysis and reconstruction in the treatment of terrible triad injury with a poor outcome after surgical as well as conservative intervention. MATERIALS AND METHODS: Twelve patients (12 elbows) with the diagnosis of terrible triad injury were respectively reviewed. All the 12 patients had elbow dysfunction after conservative and surgical treatment of the terrible triad injury. Preoperatively, the flexion arc and forearm rotation were 36.7° ± 28.5° and 51.3° ± 43.4°, respectively, and the Mayo Elbow Performance Score was 56.3 points. The mean interval between the primary injury and our surgical treatment was 6.6 months. Our surgical intervention included elbow arthrolysis, ulnar nerve transposition, radial head replacement, coronoid process and ligament repair, and hinged external fixation. Patients were encouraged to participate in rehabilitation training 24 h after surgery. RESULTS: The mean follow-up duration was 20.1 months; the flexion arc and forearm rotation were 122° ± 18° and 140° ± 20°, respectively, and the mean Mayo Elbow Performance Score was 94.6 points (9 excellent, 3 good). Concentric stability was restored in all elbows. Complications included superficial pin tract infection (1), heterotopic ossification (3), and ulnar nerve palsy (1); the ulnar nerve symptoms had improved at the last follow-up. CONCLUSIONS: The combination of open arthrolysis and reconstruction performed at a mean interval of 6-month posttrauma can restore functional mobility in cases of terrible triad injury with a poor outcome after surgical as well as conservative intervention. Thus, it may be an effective alternative for the treatment of the poor outcome terrible triad injury. We recommend early functional rehabilitation with adherence to the guidelines for hinged external fixation.

KLF2/PPARγ axis contributes to trauma-induced heterotopic ossification by regulating mitochondrial dysfunction.

Trauma-induced heterotopic ossification (HO) is a complex disorder after musculoskeletal injury and characterized by aberrant extraskeletal bone formation. Recent studies shed light on critical role of dysregulated osteogenic differentiation in aberrant bone formation. Krupel-like factor 2 (KLF2) and peroxisome proliferator-activated receptor gamma (PPARγ) are master adapter proteins that link cellular responses to osteogenesis; however, their roles and relationships in HO remain elusive. Using a murine burn/tenotomy model in vivo, we identified elevated KLF2 and reduced PPARγ levels in tendon stem/progenitor cells (TSPCs) during trauma-induced HO formation. Both KLF2 inhibition and PPARγ promotion reduced mature HO, whereas the effects of PPARγ promotion were abolished by KLF2 overexpression. Additionally, mitochondrial dysfunction and reactive oxygen species (ROS) production also increased after burn/tenotomy, and improvements in mitochondrial function (ROS scavenger) could alleviate HO formation, but were abolished by KLF2 activation and PPARγ suppression by affecting redox balance. Furthermore, in vitro, we found increased KLF2 and decreased PPARγ levels in osteogenically induced TSPCs. Both KLF2 inhibition and PPARγ promotion relieved osteogenesis by improving mitochondrial function and maintaining redox balance, and effects of PPARγ promotion were abolished by KLF2 overexpression. Our findings suggest that KLF2/PPARγ axis exerts regulatory effects on trauma-induced HO through modulation of mitochondrial dysfunction and ROS production in TSPCs by affecting redox balance. Targeting KLF2/PPARγ axis and mitochondrial dysfunction can represent attractive approaches to therapeutic intervention in trauma-induced HO.

Development and Validation of a Deep-Learning Model to Predict Total Hip Replacement on Radiographs: The Total Hip Replacement Prediction (THREP) Model.

BACKGROUND: There are few methods for accurately assessing the risk of total hip arthroplasty (THA) in patients with osteoarthritis. A novel and reliable method that could play a substantial role in research and clinical routine should be investigated. The purpose of the present study was to develop a deep-learning model that can reliably predict the risk of THA with use of radiographic images and clinical symptom data. METHODS: This retrospective, multicenter, case-control study assessed hip joints on weighted-bearing anteroposterior pelvic radiographs obtained from Osteoarthritis Initiative (OAI) participants. Participants who underwent THA were matched to controls according to age, sex, body mass index, and ethnicity. Cases and controls were uniformly split into training, validation, and testing data sets at proportions of 72% (n = 528), 14% (n = 104), and 14% (n = 104), respectively. Images and clinical symptom data were passed through a detection model and a deep convolutional neural network (DCNN) model to predict the probability of THA within 9 years as well as the most likely time period for THA (0 to 2 years, 3 to 5 years, 6 to 9 years). Model performance was assessed with use of the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity in the testing set. RESULTS: A total of 736 participants were evaluated, including 184 cases and 552 controls. The prediction model achieved an overall accuracy, sensitivity, and specificity of 91.35%, 92.59% and 86.96%, respectively, with an AUC of 0.944, for THA within 9 years. The AUC of the DCNN model for assessing the most likely time period was 0.907 for 0 to 2 years, 0.916 for 3 to 5 years, and 0.841 for 6 to 9 years. Gradient-weighted class activation mapping closely corresponded to regions affecting the prediction of the DCNN model. CONCLUSIONS: The proposed DCNN model is a reliable and valid method to predict the probability of THA-within limitations. It could assist clinicians in patient counseling and decision-making regarding the timing of the intervention. In the future, by increasing the size of the data set, enhancing the ethnic and socioeconomic diversity of the participants, and improving the follow-up rate, the quality of the conclusions can be further improved. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Open arthrolysis and prosthetic replacement of the radial head for elbow stiffness associated with rotation limitation.

BACKGROUND: Limited forearm rotation is a frequent combined disorder in elbow stiffness. If the radial head cannot be saved during open arthrolysis, prosthetic replacement might be considered because it enhances stability and allows early motion. METHODS: In this study we retrospectively analyzed the outcome of 8 patients (7 men, 1 woman) who underwent open arthrolysis and simultaneous prosthetic replacement after resection of the radial head to restore elbow range of motion and forearm rotation. Patients were a mean age of 31.7 years (range, 22-40 years). RESULTS: Postoperatively, the mean (range) active range of motion improved from 29.4° (0°-70°) to 113.1° (80°-135°), mean (range) supination increased from 38.8° (0°-80°) to 77.5° (50°-90°), and mean (range) pronation improved from 18.8° (0°-80°) to 68.8° (50°-80°). The Mayo Elbow Performance Score improved from a mean (range) of 57.5 (50-70) to 92.5 (85-100) points. No elbow valgus instability was detected over a mean duration of 26 months of follow-up. The implant was considered stable in all patients. CONCLUSIONS: Open arthrolysis and prosthetic replacement of the radial head are effective in treating elbow stiffness with associated rotation limitation after resection of the radial head.

Prevention of Tendon Adhesions by ERK2 Small Interfering RNAs.

Tendon adhesions are one of the most concerning complications after surgical repair of flexor tendon injury. Extracellular signal-regulated kinase (ERK) 2 plays crucial roles in fibroblast proliferation and collagen expression which contributes to the formation of tendon adhesions after flexor tendon surgery. Using a chicken model, we have examined the effects of a small interfering RNA (siRNA) targeting ERK2 delivered by a lentiviral system on tendon adhesion formation with an adhesion scoring system, histological assessment, and biomechanical evaluation. It was found that ERK2 siRNA effectively suppressed the increase of fibroblasts and the formation of tendon adhesions (p < 0.05 compared with the control group). Moreover, no statistically significant reduction in breaking force was detected between the ERK2 siRNA group and the control group. These results show that the lentiviral-mediated siRNA system is effective in preventing tendon adhesion formation but not to tendon healing, and may be used for tendon repair after confirmation and improvement by future detailed studies.

Open arthrolysis and hinged external fixation for posttraumatic ankylosed elbows.

BACKGROUND: An ankylosed elbow is defined as an elbow having a range of motion of 0°. Movement is extremely limited. This study retrospectively analyzes the results of arthrolysis and hinged external fixation performed on 15 patients suffering from ankylosed elbows. METHODS: Fifteen completely ankylosed elbows were treated by arthrolysis and hinged external fixation. Patients comprised nine men and six women, with a mean age of 37.93 years (37.93 ± 9.68) when arthrolysis was performed. Before surgery, the elbows were ankylosed at various angles ranging from 30° to 85°. Eleven patients underwent arthrolysis by medial and lateral approaches, three patients by the posterior approach, and one patient by posterior and lateral approaches. Hinged external fixators were applied to all patients. Subcutaneous anterior transposition of the ulnar nerve was performed in all patients. RESULT: All patients received satisfactory follow-up. The range of motion of the elbow improved from 0° preoperatively to a postoperative mean of 115.67° (115.67 ± 23.29). The Mayo Elbow Performance Score improved from a mean of 67.67 ± 11.00 to 86.67 ± 8.38 points, with excellent results in nine patients, good in five, and fair in one. This difference is statistically significant (t = -6.862; p < 0.001). CONCLUSION: Open arthrolysis and monolateral hinged external fixation are effective in treating posttraumatic ankylosed elbow. Arthrolysis should be performed by a combination of lateral and medial approaches. In addition, routine hinged external fixation and anterior transposition of the ulnar nerve may improve the postoperative recovery of elbow stiffness.

lncRNA MEG3 Promotes Osteogenic Differentiation of Tendon Stem Cells Via the miR-129-5p/TCF4/ß-Catenin Axis and thus Contributes to Trauma-Induced Heterotopic Ossification.

BACKGROUND: Heterotopic ossification (HO) is one of the most intractable conditions following injury to the musculoskeletal system. In recent years, much attention has been paid to the role of lncRNA in musculoskeletal disorders, but its role in HO was still unclear. Therefore, this study attempted to determine the role of lncRNA MEG3 in the formation of post-traumatic HO and further explore the underlying mechanisms. RESULTS: On the basis of high-throughput sequencing and qPCR validation, elevated expression of the lncRNA MEG3 was shown during traumatic HO formation. Accordingly, in vitro experiments demonstrated that lncRNA MEG3 promoted aberrant osteogenic differentiation of tendon-derived stem cells (TDSCs). Mechanical exploration through RNA pulldown, luciferase reporter gene assay and RNA immunoprecipitation assay identified the direct binding relationship between miR-129-5p and MEG3, or miR-129-5p and TCF4. Further rescue experiments confirmed the miR-129-5p/TCF4/ß-catenin axis to be downstream molecular cascade responsible for the osteogenic-motivating effects of MEG3 on the TDSCs. Finally, experiments in a mouse burn/tenotomy model corroborated the promoting effects of MEG3 on the formation of HO through the miR-129-5p/TCF4/ß-catenin axis. CONCLUSIONS: Our study demonstrated that the lncRNA MEG3 promoted osteogenic differentiation of TDSCs and thus the formation of heterotopic ossification, which could be a potential therapeutic target.

[The second dorsal metacarpal artery flap relaying the dorsal island flap of the index finger for the repair of soft tissue defect of thumb].

Objective: To investigate the effectiveness of the second dorsal metacarpal artery fascial vascular pedicle retrograde island flap relaying the dorsal island flap of the index finger in repairing skin and soft tissue defects of the thumb. Methods: The clinical data of 8 patients with skin and soft tissue defects of thumb between October 2019 and January 2021 were retrospectively analyzed. There were 3 males and 5 females with an average age of 35 years (range, 18-52 years). The causes of injury included machine injury in 2 cases, crush injury in 3 cases, and cutting injury in 3 cases. There were 2 cases of dorsal defect of the proximal part, 1 dorsal defect of the distal part, and 5 instances of the distal part defect. The skin and soft tissue defects ranged from 1.7 cm×1.4 cm to 3.0 cm×2.5 cm. The time from injury to flap repair was 7-21 days, with an average of 14 days. Firstly, the dorsal island flap of the index finger (dorsal side of the proximal part of the index finger) was used to repair the defect of the thumb. Then the second dorsal metacarpal artery fascia vascular pedicle retrograde island flap (near the radial side of the back of the hand) was used to repair the dorsal defect of the index finger; the donor site was sutured directly. Results: Vascular crisis of the flap occurred in 1 case within 48 hours after operation, and the flap was bloated and bruised in 1 case due to excessive suture tension, and all the flaps survived after symptomatic treatment; partial skin margin of the flap was necrotic in 1 case after operation, and the incision healed after dressing change; the other 5 flaps survived, and all the wounds in the donor and recipient sites healed by first intention. All the 8 patients were followed up 3-10 months, with an average of 6 months. One patient had mild scar; the other patients had no significant difference in the color of the flap and the surrounding skin, no adhesion of tendons, and little interference of index finger function, and there was no obvious pain and dysfunction in the donor and recipient sites of the flap. At last follow-up, the extension-flexion range of motion of the metacarpophalangeal joint of the thumb was 0°-55°, and that of the interphalangeal joint was 0°-75°; the extension-flexion range of motion of the metacarpophalangeal joint of the index finger was 0°-82°, that of the proximal interphalangeal joints was 0°-90°, and that of the distal interphalangeral joints was 0°-65°. Conclusion: The application of the second dorsal metacarpal artery fascial vascular pedicle retrograde island flap relaying the dorsal island flap of the index finger to repair skin and soft tissue defect wounds of thumb is a feasible treatment with reliable blood supply, less postoperative complications, no need for skin grafting, less interference to the function of the index finger, and satisfactory wound repair effect.

Association Between Tranexamic Acid Use and Heterotopic Ossification Prevalence After Elbow Trauma Surgery: A Propensity-Score-Matched Cohort Study.

BACKGROUND: Heterotopic ossification (HO) is a common complication of elbow trauma that can affect limb mobility. Inflammation is an initiating factor for HO formation. Tranexamic acid (TXA) can reduce the inflammatory response after orthopaedic surgery. However, evidence regarding the effectiveness of TXA use for HO prevention after elbow trauma surgery is lacking. METHODS: This retrospective observational propensity-score-matched (PSM) cohort study was conducted from July 1, 2019, to June 30, 2021, at the National Orthopedics Clinical Medical Center, Shanghai, People's Republic of China. A total of 640 patients who underwent surgery following elbow trauma were evaluated. The present study excluded patients with an age of <18 years; those with a history of elbow fracture; those with a central nervous system injury, spinal cord injury, burn injury, or destructive injury; and those who had been lost to follow-up. After 1:1 matching on the basis of sex, age, dominant arm, injury type, open injury, comminuted fracture, ipsilateral trauma, time from injury to surgery, and nonsteroidal anti-inflammatory drug use, the TXA group and the no-TXA group comprised 241 patients each. RESULTS: In the PSM population, the prevalence of HO was 8.71% in the TXA group and 16.18% in the no-TXA group (with rates of 2.07% and 5.80% for clinically important HO, respectively). Logistic regression analyses showed that TXA use was associated with a lower rate of HO (odds ratio [OR], 0.49; 95% CI, 0.28 to 0.86; p = 0.014) than no TXA use, as well as with a lower rate of clinically important HO (OR, 0.34; 95% CI, 0.11 to 0.91; p = 0.044). None of the baseline covariates significantly affected the relationship between TXA use and HO rate (p > 0.05 for all). Sensitivity analyses supported these findings. CONCLUSIONS: TXA prophylaxis may be an appropriate method for the prevention of HO following elbow trauma. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.