The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow-twitch fibers, the majority of fast-twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles-related diseases. Anat Rec, 299:1397-1401, 2016. © 2016 Wiley Periodicals, Inc.
Background: Patella fractures treated with traditional open approach and tension band fixation are associated with a significant rate of soft tissues complications, including hardware irritation, postoperative adhesions and non-cosmetic scar. An alternative is to utilize cannulated screws and high-strength sutures by the minimally invasive technique. Methods: This retrospective study comprised 48 patients who had been treated for unilateral closed transverse patellar fracture, type 34C1 according to the AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification, between June 2018 to June 2020. All patients were treated either by closed reduction and internal fixation using cannulated screws combined with high-strength sutures and Nice knots (the CRIF-NK group, n=24), or traditional open reduction and internal fixation using cannulated screws and tension band wiring (the ORIF-TBW group, n=24). The operative time and intraoperative blood loss for each patient were recorded. All the patients were underwent a regularly clinical and radiological follow-up. The clinical evaluation was performed using the Böstman scale and the Visual Analogue Scale (VAS) for pain.Results: Average follow up was 21.9 months (range, 16-29 months). The mean intraoperative blood loss of the CRIF-NK group (35.21±6.16 mL) was significantly less than that of the ORIF-TBW group (75.42±7.92 mL; P<0.001). The mean VAS scores at 4 and 8 weeks and the mean Böstman scale score at 8 weeks after surgery were significantly better in the 1.47±0.40 and 28.13±0.94, respectively) than the ORIF-TBW group (5.16±0.68, 3.14±0.72 and 26.33±1.00, respectively; all P<0.001). No significant differences were observed between the two groups in terms of operative time, Böstman scale score at 1-year follow-up, or fracture healing time. The union rate was 100% (24/24) in both groups. One patient (1/24) in the CRIF-NK group, and all patients (24/24) in the ORIF-TBW group required internal fixation removal. Conclusions:The percutaneous minimally invasive technique using cannulated screws combined with high-strength sutures and Nice knots exhibited some superiority to traditional open reduction with cannulated screws and tension band wiring for treatment of transverse patellar fractures in terms of efficacy and safety by reducing soft-tissue stimulating complications and promoting functional recovery.
The failure to accept reinnervation is considered to be one of the reasons for the poor motor functional recovery of intrinsic hand muscles (IHMs) after nerve injury. Rat could be a suitable model to be used in simulating motor function recovery of the IHMs after nerve injury as to the similarities in function and anatomy of the muscles between human and rat. However, few studies have reported the muscle fiber types composition and endplate morphologic characteristics of intrinsic forepaw muscles (IFMs) in the rat. In this study, the myosin heavy chain isoforms and acetylcholine receptors were stained by immunofluorescence to show the muscle fiber types composition and endplates on type-identified fibers of the lumbrical muscles (LMs), interosseus muscles (IMs), abductor digiti minimi (AM) and flexor pollicis brevis (FM) in rat forepaw. The majority of IFMs fibers were labeled positively for fast-switch fiber. However, the IMs were composed of only slow-switch fiber. With the exception of the IMs, the other IFMs had a part of hybrid fibers. Two-dimensional morphological characteristics of endplates on I and IIa muscle fiber had no significant differences among the IFMs. The LMs is the most suitable IFMs of rat to stimulate reinnervation of the IHMs after nerve injury. Gaining greater insight into the muscle fiber types composition and endplate morphology in the IFMs of rat may help understand the pathological and functional changes of IFMs in rat model stimulating reinnervation of IHMs after peripheral nerve injury.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.