Workflow and Outcome of Thrombectomy in Late Time Window: A Pooled Multicenter Analysis.

BACKGROUND: We investigated the impact of workflow times on the outcomes of patients treated with endovascular thrombectomy (EVT) in the late time window. METHODS: Individual patients' data who underwent EVT in the late time window (onset to imaging >6 hours) were pooled from seven registries and randomized clinical trials. Multiple time intervals were analyzed. Mixed-effects logistic regression was used to estimate the likelihood of functional independence at 90 days (modified Rankin Scale 0-2). Mixed-effects negative binomial regression was used to evaluate the relationship between patient characteristics and workflow time intervals. RESULTS: 608 patients were included. The median age was 70 years (IQR: 58-71), 307 (50.5%) were female, and 310 (53.2%) had wake-up strokes. Successful reperfusion was achieved in 493 (81.2%) patients, and 262 (44.9%) achieved 90-day mRS 0-2. The estimated odds of functional independence decreased by 13% for every 30 minute delay from emergency department (ED) arrival to imaging time and by 7% from ED arrival to the end of EVT in the entire cohort. Also, the estimated odds of functional independence decreased by 33% for every 30 minute delay in the interval from arterial puncture to end of EVT, 16% in the interval from arrival in ED to end of EVT and 6% in the interval from stroke onset to end of EVT among patients who had a wake-up stroke. CONCLUSION: Faster workflow from ED arrival to end of EVT is associated with improved functional independence among stroke patients treated in the late window.

The credibility of subgroup analyses reported in stroke trials is low: A systematic review.

BACKGROUND: Subgroup analyses are widely used to evaluate the heterogeneity of treatment effects in randomized clinical trials. However, there is a limited investigation of the quality of prespecified and reported subgroup analyses in stroke trials. This study evaluated the credibility of subgroup analyses in stroke trials. METHODS AND ANALYSIS: We searched Medline/PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Web of Science from inception to 24 March 2021. Three reviewers screened, extracted, and analyzed the data from the publications. Primary publications of stroke trials that reported at least one subgroup effect and had published corresponding study protocols were included. The Instrument for Assessing the Credibility of Effect Modification Analyses (ICEMAN) was used to examine the quality of the subgroup effects reported, with each subgroup effect assigned a credibility rating ranging from very low to high. Subgroup effects with two or more "definitely no" responses received a low credibility rating. The risk of bias was assessed using the Cochrane Risk-of-Bias tool for randomized trials version 2. RESULTS: Seventy-four articles met the inclusion criteria and reported a combined total of 647 subgroup effects. The median sample size was 1264 (interquartile range (IQR): 380-3876), and the median number of subgroups prespecified in the protocol was 6 (IQR: 2-10). Sixty-one (82%) studies used the univariate test of interaction. Of the total 647 subgroup effects reported in these studies, 319 (49%) were reported in acute stroke trials, while 423 (65%) had low credibility. CONCLUSION: The quality of subgroup analysis reporting in stroke trials remains poor. More effort is needed to train trialists on the best methods for designing and performing subgroup analyses, and how to report the results. TRIAL REGISTRATION NUMBER: We prospectively registered the review with International Prospective Register for Systematic Reviews (registration number: CRD42020223133).

Patient gender and rotator cuff surgery: are there differences in outcome?

BACKGROUND: Although rotator cuff syndrome is common and extensively studied from the perspective of producing healed tendons, influence of gender on patient-reported outcomes is less well examined. As activity and role demands may vary widely between men and women, clarity on whether gender is an important factor in outcome would enhance patient education and expectation management. Our purpose was to determine if differences exist in patient-reported outcomes between men and women undergoing rotator cuff surgery. METHODS: One hundred forty-eight participants (76 W:72 M) aged 35-75 undergoing surgery for unilateral symptomatic rotator cuff syndrome were followed for 12 months after surgery. Demographics, surgical data, and the Western Ontario Rotator Cuff (WORC) scores were collected. Surgery was performed by two fellowship-trained shoulder surgeons at a single site. RESULTS: There were no gender-based differences in overall WORC score or subcategory scores by 12 months post-op. Pain scores were similar at all time points in men and women. Women were more likely to have dominant-arm surgery and had smaller rotator cuff tears than men. Complication rates were low, and satisfaction was high in both groups. CONCLUSION: Patient gender doesn't appear to exert an important effect on patient-reported rotator cuff outcomes in this prospective cohort. Further work examining other covariates as well as the qualitative experience of going through rotator cuff repair should provide greater insight into factors that influence patient-reported outcomes.

The Dose-Response Effect of the Mast Cell Stabilizer Ketotifen Fumarate on Posttraumatic Joint Contracture: An in Vivo Study in a Rabbit Model.

Posttraumatic joint contracture is a debilitating complication following an acute fracture or intra-articular injury that can lead to loss of motion and an inability to complete activities of daily living. In prior studies using an established in vivo model, we found that ketotifen fumarate (KF), a mast cell stabilizer, was associated with a significant reduction in the severity of posttraumatic joint contracture. Our primary research question in the current study was to determine whether a dose-response relationship exists between KF and posttraumatic joint contracture reduction. METHODS: A standardized operative method to create posttraumatic joint contracture in a knee was performed on skeletally mature New Zealand White rabbits. The animals were randomly assigned to 1 of 5 groups (n = 10 per group): a nonoperative control group, an operative control group, or 1 of 3 experimental KF groups (0.01 mg/kg [the KF 0.01 group], 0.1 mg/kg [KF 0.1], or 5.0 mg/kg [KF 5.0]). Flexion contractures were measured following 8 weeks of knee immobilization using a hydraulic material-testing machine. The posterior knee joint capsules were then harvested for quantification of myofibroblast and mast cell numbers with immunohistochemistry analysis. RESULTS: Forty-five rabbits were used in the final analysis. Contracture severity was significantly reduced in the KF 0.1 group (p = 0.016) and the KF 5.0 group (p = 0.001) compared with the operative control group. When converted to a percent response, posttraumatic joint contracture reduction was 13%, 45%, and 63% for the KF 0.01, KF 0.1, and KF 5.0 groups, respectively. A half-maximal effective concentration (EC50) for KF of 0.22 mg/kg was established. There was also a decrease in myofibroblasts, mast cells, and substance P-containing nerve fiber counts with increasing doses of KF. CONCLUSIONS: Using a preclinical, rabbit in vivo model of posttraumatic joint contracture, increasing doses of KF were associated with decreasing biomechanical estimates of knee posttraumatic joint contracture as well as decreasing numbers of myofibroblasts, mast cells, and substance P-containing nerve fibers. CLINICAL RELEVANCE: KF has been used safely in humans for more than 40 years and, to our knowledge, is the first and only agent ready to be potentially translated into an effective treatment for posttraumatic joint contracture.

Is Immobilization Necessary for Early Return to Work Following Distal Biceps Repair Using a Cortical Button Technique?: A Randomized Controlled Trial.

BACKGROUND: Improvements in surgical fixation to repair distal biceps tendon ruptures have not fully translated to earlier postoperative mobilization; it is unknown whether earlier mobilization affords earlier functional return to work. This parallel-arm randomized controlled trial compared the impact of early mobilization versus 6 weeks of postoperative immobilization following distal biceps tendon repair. METHODS: One hundred and one male participants with a distal biceps tendon rupture that was amenable to a primary repair with use of a cortical button were randomized to early mobilization (self-weaning from sling and performance of active range of motion as tolerated during first 6 weeks) (n = 49) or 6 weeks of immobilization (splinting for 6 weeks with no active range of motion) (n = 52). Follow-up assessments were performed by a blinded assessor at 2 and 6 weeks and at 3, 6, and 12 months. At 12 months, distal biceps tendon integrity was verified with ultrasound. The primary outcome was return to work. Secondary outcomes were pain, range of motion, strength, shortened Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) score, and tendon integrity. Intention-to-treat analysis was performed. A linear mixed model for repeated measures was used to compare pain, range of motion, strength, and QuickDASH between the groups over time; return to work was assessed with use of independent t tests. RESULTS: The groups were similar preoperatively (p ≥ 0.16). The average age (and standard deviation) was 44.7 ± 8.6 years. Eighty-three participants (82%) were followed to 12 months. There were no differences between the groups in terms of return to work (p ≥ 0.83). Participants in the early mobilization group had significantly more passive forearm supination (p = 0.04), with passive forearm pronation (p = 0.06) and active extension and supination (p = 0.09) trending toward significantly greater range of motion in the early mobilization group relative to the immobilization group. Participants in the early mobilization group had significantly better QuickDASH scores over time than those in the immobilization group (p = 0.02). There were no differences between the groups in terms of pain (p ≥ 0.45), active range of motion (p ≥ 0.09), or strength (p ≥ 0.70). Two participants (2.0%, 1 in each group) had full-thickness tears on ultrasound at 12 months (p = 0.61). Compliance was not significantly different between the groups (p = 0.16). CONCLUSIONS: Early motion after distal biceps tendon repair with cortical button fixation is well tolerated and does not appear to be associated with adverse outcomes. No clinically important group differences were seen. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Surgical outcomes and complications following distal biceps tendon reconstruction: a systematic review and meta-analysis.

BACKGROUND: Primary repair of chronic distal biceps tendon ruptures may not be possible because of tendon retraction, and there remains no clear consensus on the type of reconstruction technique used. The purpose of this study was to report the clinical outcomes and complication rates following reconstruction of chronic distal biceps tendon ruptures. METHODS: A systematic review was performed following PRISMA guidelines. The following databases were searched: Embase, MEDLINE, and Cochrane Central Register of Controlled Trials. The primary outcomes of interest included range of motion, strength, and functional outcome scores. Secondary outcomes included complication, reoperation, and revision rates. Outcomes and complication rates of each graft type and fixation technique were aggregated and compared with nonparametric Wilcoxon signed rank and rank sum tests. Spearman rank coefficients were calculated for time from injury to surgery on all outcomes. RESULTS: There were no significant differences found between the graft type or fixation technique for postoperative range of motion, strength, and patient-reported outcomes. Postoperative complications were substantially higher in the autograft group (34%) as compared to the allograft group (14%). The fixation technique used also demonstrated a significantly increased complication rate in the weave group compared with the onlay group (34% and 9%, respectively). CONCLUSION: Our results do not reveal any statistically significant differences between groups in the primary outcomes. However, substantially higher complication rates were observed in the autograft and weave cohorts; more than half of the complications related to the use of autograft were associated with donor site morbidity. No specific graft type was identified as superior, although this may be due to the small patient numbers included within this study.

PrEvention of Posttraumatic contractuRes with Ketotifen 1 (PERK 1): A Randomized Clinical Trial.

OBJECTIVE: To assess the use of ketotifen fumarate (KF) to reduce posttraumatic contractures after elbow fractures and/or dislocations. DESIGN: Randomized clinical trial. SETTING: Three hospitals in Calgary, Canada, including one Level 1 trauma center. PARTICIPANTS: Adults (n = 151) sustaining operative or nonoperatively managed isolated distal humerus or proximal radius ± ulna fractures or elbow dislocations within 7 days of injury. INTERVENTIONS: KF 5 mg (n = 74) or lactose placebo (PL, n = 77) orally twice daily for 6 weeks. MAIN OUTCOMES: Primary outcome elbow flexion-extension arc range of motion (ROM) at 12 weeks postrandomization. Safety measures including serious adverse events and radiographic fracture line disappearance from 2 to 52 weeks postrandomization. RESULTS: The elbow ROM (mean, confidence interval) was not significantly different between KF (122 degrees, 118-127 degrees) and PL (124 degrees, 119-130 degrees) groups (P = 0.56). There was a significant difference in elbow ROM at 12 weeks postrandomization comparing operative (117 degrees, 112-122 degrees) versus nonoperative groups (128 degrees, 124-133 degrees) irrespective of intervention (P = 0.0011). There were 11 serious adverse events (KF = 6, PL = 5) that were those expected in an elbow fracture population potentially taking KF. There was no statistically significant difference in the rates of these events between the groups. The disappearance of fracture lines over the course of time was similar between groups. There was one nonunion in each group. CONCLUSIONS: In a population of operative and nonoperatively managed elbow fractures and/or dislocations KF did not reduce posttraumatic contractures. The administration of KF in this population was not found to result in a significantly higher number of major adverse events when compared with placebo. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Human serum mast cell tryptase levels in elbow fractures or dislocations and its association with injury severity.

Mast cells contain an abundance of tryptase, and preclinical models have shown elevated serum mast cell tryptase (SMCT) in the setting of posttraumatic joint contractures. Therefore, SMCT emerged as a potential biomarker to help recognize patients with more severe injuries and a higher likelihood of developing contractures. The objective of this study is to assess SMCT levels in participants with varying severity of elbow fractures and/or dislocations. A prospective cohort including 13 participants with more severe injuries that required an operation and 28 participants with less severe injuries managed nonoperatively were evaluated. A control group of eight individuals without elbow injuries was also evaluated. The SMCT levels were measured using an enzyme-linked immunosorbent assay kit specific for human mast cell tryptase. A one-way analysis of variance and Tukey's Honest Significance test was used to assess for statistical significance among and between the three groups. The average time from injury to the collection of the blood samples was 4 ± 2 days. Highly significant differences were identified between the operative, nonoperative, and control groups (P = .0005). In the operative group, SMCT levels were significantly higher than the nonoperative group (P = .0005) and the control group (P = .009), suggesting a correlation between SMCT levels and injury severity. There was no statistically significant difference in SMCT levels between the nonoperative and control groups. The SMCT levels were elevated in participants with acute elbow injuries requiring operative intervention, suggesting that SMCT levels were higher in injuries regarded as more severe.

PrEvention of posttraumatic contractuRes with Ketotifen 2 (PERK 2) - protocol for a multicenter randomized clinical trial.

BACKGROUND: Injuries and resulting stiffness around joints, especially the elbow, have huge psychological effects by reducing quality of life through interference with normal daily activities such as feeding, dressing, grooming, and reaching for objects. Over the last several years and through numerous research results, the myofibroblast-mast cell-neuropeptide axis of fibrosis had been implicated in post-traumatic joint contractures. Pre-clinical models and a pilot randomized clinical trial (RCT) demonstrated the feasibility and safety of using Ketotifen Fumarate (KF), a mast cell stabilizer to prevent elbow joint contractures. This study aims to evaluate the efficacy of KF in reducing joint contracture severity in adult participants with operately treated elbow fractures and/or dislocations. METHODS/DESIGN: A Phase III randomized, controlled, double-blinded multicentre trial with 3 parallel groups (KF 2 mg or 5 mg or lactose placebo twice daily orally for 6 weeks). The study population consist of adults who are at least 18 years old and within 7 days of injury. The types of injuries are distal humerus (AO/OTA type 13) and/or proximal ulna and/or proximal radius fractures (AO/OTA type 2 U1 and/or 2R1) and/or elbow dislocations (open fractures with or without nerve injury may be included). A stratified randomization scheme by hospital site will be used to assign eligible participants to the groups in a 1:1:1 ratio. The primary outcome is change in elbow flexion-extension range of motion (ROM) arc from baseline to 12 weeks post-randomization. The secondary outcomes are changes in ROM from baseline to 6, 24 & 52 weeks, PROMs at 2, 6, 12, 24 & 52 weeks and impact of KF on safety including serious adverse events and fracture healing. Descriptive analysis for all outcomes will be reported and ANCOVA be used to evaluate the efficacy KF over lactose placebo with respect to the improvement in ROM. DISCUSSION: The results of this study will provide evidence for the use of KF in reducing post-traumatic joint contractures and improving quality of life after joint injuries. TRIAL REGISTRATION: This study was prospectively registered (July 10, 2018) with ClinicalTrials.gov reference: NCT03582176.

Clinical outcomes and complications following primary total elbow arthroplasty using the Latitude prosthesis.

BACKGROUND: The Latitude total elbow arthroplasty (TEA) is an implant with limited published data on its performance and outcomes. The aim of this study was to report the short-term outcomes of the Latitude TEA as well as to describe the radiographic outcomes and complications. METHODS: The Latitude was implanted in 20 patients (23 elbows) in a linked configuration. Patients were recalled to clinic for the assessment of their range-of-motion and compared to preoperative values. Administration of functional outcome measures was also performed. RESULTS: Mean follow-up was 4.7 years (range, 1 to 7.5 years) with four elbows requiring revision. The flexion-extension arc improved from 86.6 to 101.3 (range, 76 to 126) postoperatively (p = 0.04). The average Disabilities of the Arm, Shoulder, and Hand score was 28.1 (range, 5.8 to 50.4) and the average Mayo Elbow Performance Score was 89.6 (range, 76 to 100), with 83% of elbows scoring in the good or excellent range. Radiolucencies were detected in 60% of patients and 31% of these lucencies progressed in size at the time of follow-up. CONCLUSIONS: The Latitude prosthesis provides patients with favorable clinical outcomes with improvements in their range-of-motion and a complication rate comparable to other elbow arthroplasty implants.

Serum Mast Cell Tryptase as a Marker of Posttraumatic Joint Contracture in a Rabbit Model.

OBJECTIVES: Mast cells have been identified as key mediators of posttraumatic joint contracture, and stabilizing medications (ketotifen) have been shown to decrease contracture severity. Serum mast cell tryptase (SMCT) levels are used clinically to monitor mast cell-mediated conditions. The goals of this study were to determine if SMCT levels are elevated in the setting of joint contracture, if they can be decreased in association with ketotifen therapy, and if they correlate with contracture severity. METHODS: This study used a previously developed rabbit model in which 39 animals were divided into 4 groups: operatively created joint contracture (ORC, n = 13), operatively created contracture treated with ketotifen at 2 doses (KF0.5, n = 9; KF1.0, n = 9), and healthy rabbits (NC, n = 8). Range of motion measures were performed at 8 weeks after the surgery. Serum samples were collected on postoperative days 1, 3, 5, 7, 21, 35, and 49. SMCT levels were measured using a rabbit-specific enzyme-linked immunosorbent assay. RESULTS: Levels of SMCT were highest in the operatively created joint contracture group and were significantly greater compared with both ketotifen groups (P < 0.001). Levels were highest at postoperative day 1 with a trend to decrease over time. A positive correlation between SMCT levels and contracture severity was observed in all operative groups (P < 0.05). CONCLUSIONS: Levels of SMCT are elevated in the setting of joint contracture, decreased in association with ketotifen therapy, and positively correlated with contracture severity. This is the first study to establish a relationship between SMCT and joint injury. Measurement of SMCT may be valuable in identifying those at risk of posttraumatic joint contracture.

Fungal periprosthetic joint infection following total elbow arthroplasty: a case report and review of the literature.

BACKGROUND: With improving surgical techniques for total elbow arthroplasty clinical outcomes have improved and its utilization continues to increase. Despite these advances, complication rates remain as high as 24%. Of these complications periprosthetic joint infection is one of the most common and morbid. The rheumatoid elbow remains a leading indication for total elbow arthroplasty. Patients with this condition frequently require immunosuppressive therapy, which places them at higher risk of both typical and atypical infections. CASE PRESENTATION: We present the case of a persistent, late-onset periprosthetic joint infection in a total elbow arthroplasty of a 64-year-old Caucasian woman with severe refractory rheumatoid arthritis. The offending pathogen, Aspergillus terreus, is previously unreported in the arthroplasty literature and grew concurrently with coagulase-negative staphylococcus. Eradication of the fungal and bacterial agents involved resection arthroplasty, serial debridement, and multiple courses of intravenous and oral antimicrobial therapy. Two attempts at reimplantation arthroplasty failed to eliminate the infection and our patient ultimately required definitive resection arthroplasty. CONCLUSIONS: Arthroplasty in the rheumatoid elbow confers with it a high complication rate. Inflammatory disease and immunosuppressive drugs combined with the subcutaneous anatomy of the elbow contribute to the risk of infection. Fungal periprosthetic joint infection in the rheumatoid patient presents both diagnostic and therapeutic challenges. Fungal growth should always be treated and requires organism-specific antimicrobials in conjunction with surgical debridement. More literature is needed to determine the optimal treatment regimen for this devastating complication.

Reconstruction of medial collateral ligament defects with a flexor-pronator fascia patch in complete open release of stiff elbows.

BACKGROUND: Because medial elbow stability is essential for stiff elbow release, surgical techniques have been reported for reconstructing medial elbow stability. However, medial collateral ligament (MCL) defects, caused by inevitable detachment and resection performed for complete release, make the reconstruction more challenging. To our knowledge, no study has evaluated the outcomes after using a flexor-pronator fascia patch in medial elbow reconstruction for open release of stiff elbows. We hypothesized that this technique is effective for repairing MCL defects. METHODS: We retrospectively reviewed the records of 10 patients. The MCL defects were all reconstructed with a flexor-pronator fascia patch. An external fixator was used in all patients. One patient could not be contacted and was thus excluded from the study. Outcome measures included stability, range of motion, Mayo Elbow Performance Score, ulnar nerve symptoms, power grip, and radiographic findings. RESULTS: The mean follow-up period was 19.6 months; all elbows were stable by the last follow-up. One patient presented with moderate elbow instability and then regained stability 3 months after the external fixator was removed. The Mayo Elbow Performance Score improved from 58 points to 94 points, and the mean flexion arc improved from 40° to 133°. No radiographic manifestations of elbow dislocation or suture anchor looseness were observed. CONCLUSION: A flexor-pronator fascia patch provides sufficient stability for repairing MCL defects without restricting the range of motion gained during arthrolysis.

Open arthrolysis for elbow stiffness increases carrying angle but has no impact on functional recovery.

BACKGROUND: With the exception of normal anatomic changes in the medial collateral ligament and radial head, other factors related to carrying angle changes have not been systematically studied. We reviewed patients who underwent open arthrolysis of the elbow, and evaluated if open arthrolysis could change carrying angle. We then identified factors associated with carrying angle changes. METHODS: Fifty patients with a minimum of 24 months of follow-up after open arthrolysis were evaluated retrospectively. Preoperative and postoperative carrying angles were compared. RESULTS: The carrying angles of 36 elbows in 36 patients were unchanged after surgery (Group A), while the carrying angles of 14 elbows in 14 patients increased postoperatively (Group B). In Group A, mean postoperative extension and flexion were 7° (range 0-24°) and 125° (range 10-135°) respectively, while mean postoperative pronation and supination were 60° (range 50-80°) and 65° (range 30-85°), respectively. In Group B, mean postoperative extension and flexion were 25° (range 0-40°) and 128° (range 60-138°), while mean postoperative pronation and supination were 65° (range 45-85°) and 60° (range 45-75°), respectively. No significant difference in range of motion and Mayo Elbow Performance Score was observed between the two groups. CONCLUSIONS: During open arthrolysis, humeral trochlea debridement and techniques for improving forearm rotation could increase carrying angle. However, this had no impact on elbow functional recovery.

Neuroinflammatory Mechanisms of Connective Tissue Fibrosis: Targeting Neurogenic and Mast Cell Contributions.

Significance: The pathogenesis of fibrogenic wound and connective tissue healing is complex and incompletely understood. Common observations across a vast array of human and animal models of fibroproliferative conditions suggest neuroinflammatory mechanisms are important upstream fibrogenic events. Recent Advances: As detailed in this review, mast cell hyperplasia is a common observation in fibrotic tissue. Recent investigations in human and preclinical models of hypertrophic wound healing and post-traumatic joint fibrosis provides evidence that fibrogenesis is governed by a maladaptive neuropeptide-mast cell-myofibroblast signaling pathway. Critical Issues: The blockade and manipulation of these factors is providing promising evidence that if timed correctly, the fibrogenic process can be appropriately regulated. Clinically, abnormal fibrogenic healing responses are not ubiquitous to all patients and the identification of those at-risk remains an area of priority. Future Directions: Ultimately, an integrated appreciation of the common pathobiology shared by many fibrogenic connective tissue conditions may provide a scientific framework to facilitate the development of novel antifibrotic prevention and treatment strategies.

Neurologic complications of distal biceps tendon repair with 1-incision endobutton fixation.

Functional outcomes of biceps tendon rupture may be optimized with operative treatment. We conducted a retrospective study to determine the neurologic complications of using 1-incision Endobutton fixation to repair distal biceps tendon ruptures. Patients with distal biceps tendon ruptures treated with a 1-incision technique and Endobutton fixation were included. The primary outcome measure was frequency of neurologic complications. All 50 patients in the study were men. Mean age was 45 years. Twenty-one patients (42%) had at least 1 complication. Injury to the lateral antebrachial cutaneous nerve (LACN) was the most common (36%). Mean time to diagnosis was 17 days (range, 0 to 40 days). Posterior interosseous, anterior interosseous, and superficial radial nerve palsies each occurred at a 4% rate. Mean follow-up was 133 days. This study involved the largest cohort of patients with distal biceps tendon rupture repaired with Endobutton fixation using a 1-incision technique. The LACN injury rate (36%) was higher than in other studies using the same technique (0% to 22%). Injury rates for other neural structures near the elbow were comparable to those in the literature.

A myofibroblast-mast cell-neuropeptide axis of fibrosis in post-traumatic joint contractures: an in vitro analysis of mechanistic components.

Previous studies have implicated a myofibroblast-mast cell-neuropeptide axis of fibrosis in pathologic joint capsules from post-traumatic contractures. The hypothesis to be tested is that joint capsule cells (JC) from human elbows with post-traumatic contractures and their interactions with mast cells (MC) and neuropeptides in the microenvironment underlie the pathogenesis of contractures. The hypothesis was tested using an in vitro collagen gel contraction model. The JC were isolated from human elbow capsules and mixed with neutralized PureCol collagen I. The gels were treated in various ways, including addition of MC (HMC-1), the neuropeptide substance P (SP), an NK1 receptor (SP receptor) antagonist RP67580 and the mast cell stabilizer ketotifen fumarate (KF). The collagen gels were released from the wells and gel size (contraction) was measured optically at multiple time points. The JC contracted collagen gels in a dose-dependent manner. This was enhanced in the presence of MC and increased further with SP. Increasing concentrations of the SP receptor antagonist, RP67580 or the mast cell stabilizer, KF decreased the magnitude of contraction. These observations identify putative mechanistic components of a myofibroblast-mast cell-neuropeptide axis of fibrosis in the joint capsules in post-traumatic contractures and potential prophylactic or therapeutic interventions.

Posttraumatic elbow joint contractures: defining pathologic capsular mechanisms and potential future treatment paradigms.

The Andrew J. Weiland Medal is presented by the American Society for Surgery of the Hand to a midcareer researcher who is dedicated to advancing patient care in the field of hand surgery. This essay, awarded the Weiland Medal in 2012, focuses on posttraumatic elbow joint contractures. Joint contractures are well known to hand surgeons because they limit function of our patients. There is a thorough understanding of the pathoanatomy underlying joint contractures. However, the mechanisms leading to the pathoanatomy are either unknown or partially understood, depending on the etiology of the particular clinical condition. This review describes our research over the past 14 years on posttraumatic elbow joint contractures. It defines pathologic cellular, matrix, and growth factor changes in the joint capsule, elaborates on the development of an animal model of posttraumatic joint contractures, presents an evaluation of a potential prevention strategy based on our research, and outlines future plans to bring this work to the clinical realm for the benefit of patients.

Posttraumatic elbow contractures: targeting neuroinflammatory fibrogenic mechanisms.

Posttraumatic elbow stiffness remains a common and challenging clinical problem. In the setting of a congruent articular surface, the joint capsule is regarded as the major motion-limiting anatomic structure. The affected joint capsule is characterized by irreversible biomechanical and biochemical fibrogenic changes strikingly similar to those observed in many other fibroproliferative human conditions. Studies in humans and preclinical animal models are providing emergent evidence that neuroinflammatory mechanisms are critical upstream events in the pathogenesis of posttraumatic connective tissue fibrogenesis. Maladaptive recruitment and activation of mast cell infiltrates coupled with the aberrant expression of growth factors such as transforming growth factor-beta, nerve growth factor, and neuropeptides such as substance P are common observations in posttraumatic joint contractures and many other fibroproliferative disorders. Blockade of these factors is providing promising evidence that if treatment is timed correctly, the fibrogenic process can be interrupted or impeded. This review serves to highlight opportunities derived from these recent discoveries across many aberrant fibrogenic disorders as we strive to develop novel, targeted antifibrotic prevention and treatment strategies for posttraumatic elbow stiffness.