Studies have demonstrated increased myofibroblasts in contractures. However, the timeline is largely unknown. The aim of this study was to determine the number of myofibroblasts in contracting joint capsules at 3-time points over a 24-week period. Eighteen rabbits subjected to a surgical procedure designed to elicit a knee joint contracture were divided into three groups of six. Rabbits were sacrificed at each respective time point and myofibroblasts in the joint capsules were quantified using immunohistochemistry. The percent of myofibroblasts was significantly elevated in the operated limbs compared to the control limbs at 2 weeks (20% vs. 7%, respectively; p ¼ 0.014). There was no difference in the percent of myofibroblasts between the operated and control limbs at 8 or 24 weeks (p ¼ 0.96 and 0.07, respectively). The percent of myofibroblasts dropped from 20% at 2 weeks to 3.0% at 8 weeks (p < 0.001). The decrease from 8 to 24 weeks was not significant (p ¼ 0.19). A large proportion of myofibroblasts are present in contracted joints at 2 weeks. By week 8, the proportion of myofibroblasts seem to return to normal. Interventions aimed at affecting the myofibroblast cell in order to prevent fibrosis should be instituted early. ß
Post-traumatic joint contracture is a debilitating consequence of trauma or surgical procedures. It is associated with fibrosis that develops regardless of the nature of initial trauma and results from complex biological processes associated with inflammation and cell activation. These processes accelerate production of structural elements of the extracellular matrix, particularly collagen fibrils. Although the increased production of collagenous proteins has been demonstrated in tissues of contracted joints, researchers have not yet determined the complex protein machinery needed for the biosynthesis of collagen molecules and for their assembly into fibrils. Consequently, the purpose of our study was to investigate key enzymes and protein chaperones needed to produce collagen-rich deposits. Using a rabbit model of joint contracture, our biochemical and histological assays indicated changes in the expression patterns of heat shock protein 47 and the a-subunit of prolyl 4-hydroxylase, key proteins in processing nascent collagen chains. Moreover, our study shows that the abnormal organization of collagen fibrils in the posterior capsules of injured knees, rather than excessive formation of fibril-stabilizing cross-links, may be a key reason for observed changes in the mechanical characteristics of injured joints. This result sheds new light on pathomechanisms of joint contraction, and identifies potentially attractive anti-fibrotic targets. ß
Objective:
To compare functional and clinical outcomes in patients with pertrochanteric hip fractures treated with either a short (SN) or long (LN) cephalomedullary nail.
Design:
Prospective, randomized.
Setting:
Clinical investigation was performed at the Mayo Clinic's Level 1 Trauma Center in Rochester, MN.
Patients/Participants:
Two hundred twenty patients with intertrochanteric fractures were prospectively randomized to an SN or LN cohort. A total of 168 patients (SN, n = 80; LN, n = 88) had a mean follow-up of 13.9 months. Fifty-two patients did not meet the minimum 3-month follow-up. Demographics were comparable between the cohorts.
Main Outcome Measures:
The primary outcome measurement was functional outcome evaluated by Short Form (SF-36) and Harris Hip scores (HHS) at 3 months. Secondary outcomes included implant failure, peri-implant fracture, mortality, operative time, estimated blood loss, and reoperation.
Results:
SN and LN cohorts were comparable in all aspects of the SF-36. There was a clinically insignificant difference in the HHS between cohorts. Patients treated in the SN cohort experienced shorter operative times but did not differ in tip-to-apex distance or subtrochanteric fracture extension. There was no difference in implant cutout, deep surgical site infection, or peri-implant fractures.
Conclusions:
Patients treated with SNs or LNs for pertrochanteric femur fractures experienced comparable functional outcomes as measured by SF-36 and HHS. When compared with the LN cohort, SN patients experienced no difference in peri-implant fracture or lag-screw cutout and tolerated up to 3 cm of subtrochanteric fracture line extension.
Level of Evidence:
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
Introduction: The proximal humerus is a common site of primary and metastatic disease in the upper extremity. Historically, the goal of a hemiarthroplasty reconstruction was to provide a stable platform for hand and elbow function, with limited shoulder function. Techniques utilizing a reverse endoprosthesis (endoprosthetic replacement [EPR]) and allograft-prosthetic composite (APC) have been developed; however, there is a paucity of comparative studies. Methods: A total of 83 (42 females, 41 males) patients undergoing an intraarticular resection of the humerus were reviewed. Reconstructions included 30 reverse and 53 hemiarthroplasty; including hemiarthroplasty EPR (n = 36) and APC (n = 17), and reverse EPR (n = 20) and APC (n = 10). Results: Reverse reconstructions had improved forward elevation (85°vs. 44°, p < .001) and external rotation (30°vs. 21°; p < .001) versus a hemiarthroplasty. Reverse reconstructions had improved American Shoulder and Elbow Surgeons scores (65 vs. 57; p = .01) and Musculoskeletal Tumor Society 93 scores (72 vs. 63; p < .001) versus hemiarthroplasty. Subluxation of the reconstruction was a common (n = 23, 27%), only occurring in hemiarthroplasty patients (EPR [n = 13, 36%] and APC [n = 10, 59%]). Conclusion: The current series highlights the improved functional outcome in patients undergoing reconstruction with a reverse arthroplasty compared to the traditional hemiarthroplasty. Currently reverse shoulder arthroplasty (APC or EPR) is our preferred methods of reconstruction in this patient population.
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