Screw fixation without bone grafting for scaphoid fracture nonunion.

INTRODUCTION: We previously reported the classification of the scaphoid fracture nonunions as linear, cystic, and sclerotic or displaced types based on radiographic findings. We have been treating the linear and cystic type fractures via screw fixation without bone grafting and the sclerotic or displaced type fractures via screw fixation with bone grafting. In this retrospective study, we report the treatment outcomes of the linear and cystic types of scaphoid fracture nonunions. METHODS: Nineteen patients with linear and cystic type scaphoid fracture nonunions were included. Two patients had linear type and 17 had cystic type fractures. All the patients were male, their mean age was 29.2 years. All patients were treated with screw fixation alone by a single surgeon. RESULTS: Bone union was achieved in 17 cases. The mean time to bone union was 3.7 months. Bone union was not achieved in one case of linear type and one case of cystic type fracture. The former was thought to be due to misdiagnosis of displaced type as linear type fracture; however, no obvious reason could be found for the latter. DISCUSSION: Screw fixation alone could help achieve bone union in linear type scaphoid fracture nonunions. However, if the type of the fracture is difficult to diagnose based on plain radiography, evaluation using computed tomography should be performed. The cystic type fractures may need to be subclassified according to the location or size of the cyst as well as the viability of the proximal bone fragment.

In Vivo Kinematics of the Thumb Carpometacarpal Joint During Flexion and Abduction.

Background: Despite the movement of the thumb carpometacarpal joint has been studied, many unclarified points remain regarding the movement of this joint. The purpose of this study was to evaluate the in vivo kinematics of the thumb carpometacarpal joint during flexion and abduction using computed tomography images. Methods: The subjects were 9 healthy males. Computed tomography images were obtained in 4 equally-divided positions from maximum extension to maximum flexion, and maximum adduction to maximum abduction of the thumb. A three-dimensional model was constructed from these images, and the models of each position were superimposed with reference to the trapezium. The amount of angular change around the bone axes of first metacarpal bone and rotation axes were evaluated. Results: We found that the first metacarpal bone showed relatively simple behavior during abduction. However, during flexion, it exhibited a particular movement in which the amount of angular change of the metacarpal bone with respect to the trapezium rapidly increased with deep flexion. Conclusions: These results suggest that the thumb carpometacarpal joint exhibits a special movement during flexion, especially deep flexion.

Sensory Disturbance of the Lower Extremity after Sural Artery Flap Elevation.

PURPOSE: Elevation of the sural artery flap with the sural nerve is associated with donor-site morbidities, such as postoperative sensory disturbance of the lower extremity. We evaluated the sensory disturbance of the lower extremity after elevation of the sural artery flap. METHODS: This study included 7 patients who underwent surgery using the sural artery flap. The sensory disturbances immediately after surgery and at present were evaluated on a 10-point scale. The influences of surgery on activities of daily living and patient satisfaction were also evaluated. RESULTS: The sensory disturbance was 4.48 immediately after surgery and 2.24 presently, and the difference between the timepoints was not statistically significant. The influence of surgery on activities of daily living was 2.30, and the patient satisfaction was 7.90. CONCLUSION: It may be necessary to consider the sural artery flap, which does not include the sural nerve, to avoid unnecessary complications. When it is unavoidable to use the sural artery flap, including the sural nerve, it is important to thoroughly inform patients beforehand about the postsurgery sensory disturbance in the lower extremities.

Facilitatory effects of artificial nerve filled with adipose-derived stem cell sheets on peripheral nerve regeneration: An experimental study.

BACKGROUND: We evaluated how artificial nerves filled with adipose-derived stem cell (ADSC) sheets could facilitate peripheral nerve regeneration. METHODS: We prepared ADSC sheets following previously described protocols. We transected the sciatic nerve in 12-week-old Wistar rats, fixed the nerve ends to the artificial conduit, and prepared three groups: (1) conduits alone (control group); (2) conduits filled with ADSCs (ADSCs group), and (3) conduits filled with ADSC sheets (ADSC sheet group). We assessed the subjects 4 and 12 weeks post-transplantation (n = 24). We investigated ßIII-tubulin and anti-S100 expression at 4 and 12 weeks post-transplantation, in longitudinal- and cross-sections of the central portion in the regenerated tissues. The vascular endothelial growth factor A (VEGFA) and neuregulin-1 expressions were analyzed using real-time reverse-transcription polymerase chain reaction (real-time RT-PCR). We evaluated the tibialis anterior muscle wet weight (affected/healthy sides, %) and sciatic function index (SFI) 12 weeks post-transplantation. RESULTS: The ADSC sheet group comprised more S100-positive cells than the other groups. The regenerated axon length in the ADSC sheet group was markedly the longest among the studied groups. The immunostaining revealed a positive area in the regenerated tissue center in all groups, tending to be the largest in the ADSC sheet group. The muscle wet weight indicated that the ADSC sheet group exhibited significantly higher weight than the control. The mean SFI showed that the ADSC sheet group exhibited significantly better results than the control. The VEGFA expression was higher both in the ADSC and the ADSC sheet group than in the control. The neuregulin-1 expression was higher both in the ADSC and the ADSC sheet group than in the control. CONCLUSIONS: The ADSC sheets could potentially support transplanting an adequate number of ADSCs at the target site. Compared with the conventional method of attaching ADSCs, the use of ADSC sheets promotes accelerated nerve regeneration.

Enhanced nerve autograft using stromal vascular fraction.

PURPOSE: While many studies have been conducted on peripheral nerve regeneration, few have focused on strengthening the nerve autografts. This study hypothesized that adding autologous stromal vascular fraction (SVF) to a nerve autograft will improve nerve regeneration. The purpose of this study was to compare the results of nerve autograft with and without SVF. METHODS: An adipose tissue sample was excised from the right inguinal region of female Wistar rats, and SVF was separated by centrifugation. The left sciatic nerve was resected at a length of 15 mm and the defect was bridged by a resected nerve autograft. We added SVF with collagen gel around the nerve autograft in the SVF group and added saline in the control group. At 12 weeks after surgery, the wet muscle weight, distal latency, and amplitude of the compound muscle action potential of the tibialis anterior were evaluated by the ratio of left and right sides. Sciatic functional index (SFI) was also evaluated. RESULTS: The wet muscle weight was significantly better in the SVF group than in the control group. The results of distal latency, amplitude, and SFI were not significantly different between the two groups; however, these results tended to be better in the SVF group than in the control group. CONCLUSION: SVF added to artificial nerve grafts has been reported to promote axonal regeneration through secretion of angiogenic, neurotrophic, and anti-apoptotic factors. This study indicates that SVF may also be effective for nerve autografts and improve the clinical result of nerve autograft.

Use of a Free Vascularized Medial Femoral Condyle Flap for Revision Surgery in a Pediatric Patient with Congenital Pseudarthrosis of the Clavicle.

The most common surgical treatment for congenital pseudarthrosis of the clavicle (CPC) is resection of the pseudarthrosis, placement of an autologous bone graft, and Kirschner wire or plate fixation. However, in some cases, bone fusion cannot be achieved at the first surgery, and an additional surgery is required. We present a case report of a boy with a right CPC who failed radiographic bone union after the first surgery. He subsequently underwent revision surgery with resection of the pseudarthrosis, plate fixation, and establishment of a vascularized medial femoral condyle (MFC) flap to ensure bone union. Three months after the revision surgery, a radiographic bone union was achieved, and no symptoms were observed for one year after the operation. There have been no previous reports of the use of a vascularized MFC flap as a treatment for CPC. We believe that this technique effectively ensures bone union during revision surgery for CPC.

Effects of hybridization of decellularized allogenic nerves with adipose-derive stem cell sheets to facilitate nerve regeneration.

We developed a sheet of stem cells derived from adipose tissue (ADSC sheet). To improve transplantation, we wrapped decellularized nerves with ADSC sheets and examined the efficacy of this recellularized nerves in nerve regeneration. Decellularized nerves were prepared from sciatic nerves of Sprague-Dawley rats. Wistar rats were subjected to sciatic nerve injury and then randomly assigned to three groups (n = 7 per group), which were transplanted with 15-mm bridge grafts; the first group received a decellularized allogenic nerve implant, the second an ADSC sheet-wrapped decellularized allogenic nerve implant, and the third an autogenous nerves were implant. No significant differences were found in S100-positive and neurofilament-positive areas, axon density, and sciatic functional index (SFI) score between rats transplanted with ADSC sheet-wrapped nerve grafts and those that received autografts. In contrast, these parameters except SFI and the amplitude ratio were significantly larger in rats grafted with ADSC sheet-wrapped nerve than with the decellularized nerve. These results suggest that the number of regenerating axons, as well as their regenerating velocity, and the number of migrating Schwann cells into the implant in rats transplanted with ADSC sheet-wrapped nerves matched those in rats transplanted with autografts. These positive effects are possibly attributable to secretion of growth factors of ADSCs.

Preventive Effect of Alginate Gel Formulation on Perineural Adhesion.

Background: Perineural adhesion is a potential complication of manipulating peripheral nerves. Using a model of median nerve manipulation in the carpal tunnel, perineural adhesion preventive effects of an alginate gel formulation were examined. Methods: After exposing carpal tunnels of Japanese white rabbits and dissecting the median nerve, the gliding floor was excised as much as possible and the transverse carpal ligament was repaired to induce a perineural tissue reaction. Prior to wound closure, 0.5 ml of alginate gel formulation was administered into the right carpal tunnel (formulation group) and 0.5 ml of physiological saline was administered into the left carpal tunnel (control group). At 1, 2, 3, and 6 weeks after treatment, electrophysiological evaluation of thenar distal latency, macroscopic evaluation with adhesion score, and pathological evaluation of carpal tunnel cross sections were performed (N = 4-5 at each time point). Results: Although distal latency tended to be low in the formulation group, there was no significant difference between the groups according to electrophysiological evaluation. Macroscopic evaluation revealed that the adhesion score was always lower in the formulation group than in the control group; over the course of treatment, it remained unchanged in the formulation group, but peaked at 3 weeks after treatment in the control group. In pathological evaluation, neural perfusion peaked at 2-3 weeks after treatment in both groups; neural perfusion tended to be lower in the formulation group than in the control group. Conclusions: Results suggested that the peak tissue response associated with nerve dissection occurred 2-3 weeks after treatment and that the repair process started subsequently. The alginate gel formulation modified the surrounding environment of the nerve and promoted repair by acting as a physical barrier against perineural fibrosis. The preventive effect of alginate gel on perineural adhesion may improve treatment outcomes of constrictive neuropathy.

Differentiated adipose-derived stem cells promote peripheral nerve regeneration.

INTRODUCTION: Many reports have indicated that adipose-derived stem cells (ADSCs) are effective for nerve regeneration. We investigated nerve regeneration by combining a polyglycolic acid collagen (PGA-c) tube, which is approved for clinical use, and Schwann cell-like differentiated ADSCs (dADSCs). METHODS: Fifteen-millimeter-long gaps in the sciatic nerve of rats were bridged in each group using tubes (group I), with tubes injected with dADSCs (group II), or by resected nerve (group III). RESULTS: Axonal outgrowth was greater in group II than in group I. Tibialis anterior muscle weight revealed recovery only in group III. Latency in nerve conduction studies was equivalent in group II and III, but action potential was lower in group II. Transplanted dADSCs maintained Schwann cell marker expression. ATF3 expression level in the dorsal root ganglia was equivalent in groups II and III. DISCUSSION: dADSCs maintained their differentiated state in the tubes and are believed to have contributed to nerve regeneration.

Long-Term Outcomes of Donor Site Morbidity After Sural Nerve Graft Harvesting.

Purpose: Although nerve autografts have been considered the standard treatment for peripheral nerve defects, limited studies have reported long-term outcomes of nerve harvesting over 15 years after surgery. This study aimed to evaluate the long-term outcomes of donor site morbidity after sural nerve graft harvesting. Methods: Thirteen patients for whom more than 15 years had passed after harvesting of the sural nerve for peripheral nerve defects were included. Mean follow-up was 29.5 years. Sensory disturbances and difficulty in performing foot movements immediately after surgery and currently were evaluated on a 10-point scale. Influences on daily living and work and current satisfaction with the autologous sural nerve graft were evaluated. Results: Sensory disturbances and difficulty in movement tended to improve; however, the differences between time points were not significant. Influences on activities of daily living and work were mild, and the satisfaction level for autologous sural nerve graft was high. Conclusions: Although donor site morbidity after sural nerve graft harvesting persisted for a long time after surgery, foot symptoms and functional impairment were mild. Type of study/level of evidence: Therapeutic V.

Topical Application of Fasudil Hydrochloride for Vasospasm during Soft Tissue Reconstruction Using a Free Flap.

Vasospasm is a phenomenon that can complicate microsurgery. We report a case in which vasospasm was quickly relieved by topical application of fasudil hydrochloride. A 36-year-old man underwent preoperative chemotherapy and wide excision for a malignant soft tissue tumor around the knee joint. We planned reconstruction using a free latissimus dorsi muscle flap for the resulting soft tissue defect and selected the peroneal vessels as the recipient vessels. However, there was no arterial blood flow from the peroneal vessels, which we diagnosed as vasospasm. Conventional treatment of the vasospasm was attempted, but blood flow was not achieved. Topical application of fasudil hydrochloride solution promptly relieved the vasospasm. To the best of our knowledge, this is the first clinical report of the use of fasudil hydrochloride for vasospasm during soft tissue reconstruction using a free flap.