Safety and efficacy of a nerve matrix membrane as a collagen nerve wrapping: a randomized, single-blind, multicenter clinical trial.

A new nerve matrix membrane derived from decellularized porcine nerves has been shown to retain the major extracellular matrix components, and to be effective in preventing adhesion between the nerve anastomosis sites and the surrounding tissues in a rat sciatic nerve transection model, thereby enhancing regeneration of the nerve. The effectiveness of the membrane may be attributed to its various bioactive components. In this prospective, randomized, single-blind, parallel-controlled multicenter clinical trial, we compared the safety and efficacy of the new nerve matrix membrane with a previously approved bovine tendon-derived type I collagen nerve wrapping. A total of 120 patients with peripheral nerve injury were recruited from Beijing Jishuitan Hospital, The First Bethune Hospital of Jilin University, and Yantai Yuhuangding Hospital, China. The patients were randomly assigned to undergo end-to-end and tension-free neurorrhaphy with nerve matrix membrane (n = 60, 52 male, 8 female, mean age 41.34 years, experimental group) or tendon-derived collagen nerve wrapping (n = 60, 42 male, 18 female, mean age 40.17 years, control group). Patients were followed-up at 14 ± 5, 30 ± 7, 90 ± 10 and 180 ± 20 days after the operation. Safety evaluation included analyses of local and systemic reactions, related laboratory tests, and adverse reactions. Efficacy evaluation included a static 2-point discrimination test, a moving 2-point discrimination test, and a Semmes-Weinstein monofilament examination. Sensory nerve function was evaluated with the British Medical Research Council Scale and Semmes-Weinstein monofilament examination. The ratio (percentage) of patients with excellent to good results in sensory nerve recovery 180 ± 20 days after the treatment was used as the primary effectiveness index. The percentages of patients with excellent to good results in the experimental and control groups were 98.00% and 94.44%, respectively, with no significant difference between the two groups. There were no significant differences in the results of routine blood tests, liver and renal function tests, coagulation function tests, or immunoglobulin tests at 14 and 180 days postoperatively between the two groups. These findings suggest that the novel nerve matrix membrane is similar in efficacy to the commercially-available bovine-derived collagen membrane in the repair of peripheral nerve injury, and it may therefore serve as an alternative in the clinical setting. The clinical trial was approved by the Institutional Ethics Committee of Beijing Jishuitan Hospital, China (approval No. 20160902) on October 8, 2016, the Institutional Ethics Committee of the First Bethune Hospital of Jilin University, China (approval No. 160518-088) on December 14, 2016, and the Institutional Ethics Committee of Yantai Yuhuangding Hospital, China (approval No. 2016-10-01) on December 9, 2016. The clinical trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2000033324) on May 28, 2020.

Radial Pronation Angle: A Novel Radiological Evaluation Index of Congenital Proximal Radioulnar Synostosis.

INTRODUCTION: Congenital proximal radioulnar synostosis (CPRUS) is a relatively rare forearm deformity that is characterized by a fixed pronated forearm of varying severity. The osseous synostosis between the proximal part of the ulna and the radius can be seen on the X-ray images in most cases. Many researchers have attempted to identify methods to measure the disease severity to guide in the treatment of CPRUS. However, to describe the overall deformity, the use of multiple indicators is essential, and some of these measurements require special software or need to be conducted on cadavers. OBJECTIVE: The aim of the current study was to introduce the radius pronation angle (RPA), a novel radiological evaluation index of CPRUS, and analyze the relationship between the RPA and the severity of the deformity. METHODS: Three-dimensional models of 43 CPRUS forearms (19 left forearms and 24 right forearms) of 32 patients (23 males and 9 females; average age was 6 years 8 months; range, from 1.5 to 27 years) treated at Beijing Ji Shui Tan Hospital during 2016 to 2019 were reconstructed using a computer-assisted technique. The special flexed posterior-anterior views of the X-ray image (the f-PA view) of the forearms were obtained, and the forearm rotation angle and the ulnar inner rotation angle were measured on each forearm. The RPA was measured on the f-PA view, and the lengths of the osseous synostosis, ulna, and the radial head were measured on the computed tomography scan images using the multiplanar reconstruction function. The Pearson index was analyzed between the RPA and the other measurements. RESULTS: The RPAs were correlated with the forearm rotation angle, ulnar inner rotation angle, relative length of the osseous synostosis, and the relative length of the radial head (P < 0.05). CONCLUSIONS: The RPA can be measured quickly and easily on the f-PA view of the X-ray image and can be used as a reliable indicator of the severity of CPRUS.

Reversed vascularized second metatarsal flap for reconstruction of Manske type IIIB and IV thumb hypoplasia with reduced donor site morbidity.

BACKGROUND: The predominant method for Manske type IIIB and IV thumb hypoplasia is pollicization. However, for those who are not willing to sacrifice the index finger, a method that could reconstruct a functionally capable and aesthetically acceptable thumb remains desirable. This study aimed to investigate and assess the functional and radiographic outcomes of utilizing a reversed vascularized second metatarsal composite flap for thumb reconstruction as a new alternative. METHODS: From May 2014 to January 2017, 15 patients with Manske type IIIB or IV thumb hypoplasia who were admitted to the Department of Hand Surgery, Beijing Jishuitan Hospital were included in this study. An osteocutaneous flap containing a section of second metatarsal and its distal head was transferred in reversed position to reconstruct carpometacarpal joint. The donor site was reconstructed by a split half of the third metatarsal. Various functional reconstructions were commenced at second stage. The reconstructed thumbs were evaluated using the Kapandji score, pinch force, and the capacities of performing daily activities through a detailed questionnaire. RESULTS: Among these 15 patients (seven type IIIB and eight type IV), there were ten boys and five girls with median age of 4.2 years (range: 2.0-7.0 years). There were seven right, three left, and five bilateral thumbs for whom only the right thumb received surgery. There were 14 metatarsal flaps survived (14/15). With an average follow-up of 19.2 months, the reconstructed thumbs had acceptable functional and aesthetic outcomes and the donor foot presented in decent appearance without signs of impaired function. All 15 children have improved the Kapandji score (from 0 to an average of 6.7), pinch force (from 0 to an average of 1.5 kg), with ability of grip and pen holding. X-ray indicated continuous bone growth. Patients and parents had good acceptance of the new thumb. CONCLUSIONS: Reconstruction of an unstable hypoplastic thumb (Manske type IIIB and IV) with use of a vascularized metatarsal is an effective strategy. It offers an alternative solution for parents insisting on saving the thumb.

[Segmental schwannomatosis in upper-extremity: 5 cases report and literature review].

OBJECTIVE: Multiple schwannomas localized in a single body part not crossing the midline constitute a rare variant of neurofibromatosis, segmental schwannomatosis. We report our experience with 5 cases of segmental schwannomatosis of the upper extremity and review the related literature to improve our skills in diagnosis and differentiation. METHODS: Five patients with segmental schwannomatosis received surgical treatment in our department from 2003 to 2012, of whom 4 were female and the other one male. The mean age was 38 years, ranging from 29 to 48 years. In retrospect, we discussed the clinical appearance, histologic characteristics, genetic data and surgical management. RESULTS: A total of 351 patients with schwannomas were treated in the recent decade. There were 326 patients with solitary schwannoma, accounting for 92.88%, 25 with neurofibromatosis type 2 (NF-2), occupying 7.12% and 5 with segmental schwannomatosis representing 1.42% of the total. Schwannomas are limited in one upper extremity and randomly located at ulnar nerve, median nerve and radial nerve and their branches, with no obvious predisposition. Their family history was negative for cutaneous tumors or central nervous system disease. Neurological examinations did not reveal symptoms related to vestibular nerves or optic nerves, which excluded NF-2 preliminarily. The prior symptom of three cases was pain which could be irradiated to the nerve distribution area. No pain but slight numbness was found in two cases. MRI disclosed multiple masses along the course of the nerves. They were isointense to muscle on T1-weighed images and hyperintense to subcutaneous fat on T2-weighed images. All schwannomas were resected and histological sections exhibited a characteristic feature of schwannoma. Follow-up work of 4.5 years was done to 4 cases and no recurrence or impairment of nerves was found. CONCLUSION: Segmental schwannomatosis is characterized by multiple schwannomas localized in one limb (upper extremity in our cases) without vestibular nerve tumors, most frequently seen in females at the age of 30-60 years. Segmental schwannomatosis is rarely seen in the previous literature. We found around 20 cases in English articles and no cases in domestic articles. In consideration of the clinical appearances of these 5 cases and the genetic research in the related literature, we recommend that segmental schwannomatosis is a distinct form of neurofibromatosis which needs to be more studied. We should also pay more attention to differentiating this disease from other forms of neurofibromatosis.

Schwannomatosis: a new member of neurofibromatosis family.

BACKGROUND: Schwannomatosis is a recently recognized peripheral nerve polyneoplasm with clinical characteristics and a genetic background that differ from those of neurofibromatosis 2 (NF2). The diagnostic and treatment criteria of this rare disorder are herein discussed. METHODS: The data of 180 patients who underwent operations for benign schwannomas from 2003 to 2012 in our center were reviewed. Eight of them were classified as schwannomatosis according to the diagnostic criteria suggested by MacCollin. The demographic characteristics were documented and compared between the two groups of patients. The patients' clinical presentations, imaging characteristics, histological features, and treatment results were retrospectively investigated and summarized. RESULTS: Of the 180 cases of benign schwannomas we reviewed this time, eight patients presented with schwannomatosis (4.44%). The mean age of the two groups was not significantly different (40.0 vs. 44.7 years, t = 0.88, P = 0.378). However, schwannnomatosis seems to more generally occur in females (75% vs. 48% were females, P = 0.162), although the difference was not statistically significant. The initial main symptom was pain. The neurological examination was otherwise normal. Magnetic resonance imaging (MRI) revealed multiple discrete, well-defined round, or oval lesions distributed along the course of the peripheral nerves in the extremities with low-to-intermediate signal intensity on T1-weighted images and high-signal intensity on T2-weighted images. Vestibular schwannomas were excluded in four patients by cranial MRI. The lesions in all patients were resected and were pathologically proven to be schwannomas. The average follow-up period was 26 months. Six individuals obtained a good result without symptoms or function loss. CONCLUSIONS: Schwannomatosis is characterized by the development of multiple schwannomas without evidence of the vestibular tumors that are diagnostic for NF2. It commonly occurs in middle-aged females. It has similar demographic features to solitary benign schwannoma. Surgical resection always results in a good outcome.

[A method of measuring the displacement of the distal radioulnar joint on the three-dimensional CT imaging].

OBJECTIVES: To establish a clinical method for measuring the displacement of the distal radioulnar joint (DRUJ) precisely irrespective of ulnar variance, and to derive normal population translation references with palmar and dorsal stress. METHODS: Thirty-seven normal distal forearms were scanned with computed tomography using an apparatus designed by Pirela-Cruz. Each extremity was scanned in two positions: maximal ulnar palmar and dorsal stress. The digital imaging and communications in medicine (DICOM) CT images were then imported into Mimics 10.0 for three-dimensional reconstruction. On the DRUJs 3D images, choose the most prominent point of the palmar and dorsal margins of the sigmoid notch and the excavate ulna fovea as the reference points A, B and C. A perpendicular line was then drawn from the point C to a line connecting points A and B with the intersection D. Calculate the ratio of AD/AB and DB/AB. Two observers measured all the DRUJs independently and one repeated the measurements one month later to determine the interobserver and intraobserver reliability. RESULTS: The mean ratio values of palmar (AD/AB) and dorsal (DB/AB) translation were 0.39 ± 0.07 and 0.37 ± 0.07, and the normal references (x(-) ± 2 s) were from 0.25 to 0.50 and from 0.23 to 0.50, respectively. No significant differences were observed in terms of positions, genders and dominant hands. The intraclass correlation coefficient (ICC) values for interobserver and intraobserver reliability (DB/AB, AD/AB) were 0.84, 0.80, 0.93 and 0.92, respectively. CONCLUSIONS: This new method could accurately measure the displacement of DRUJs with acceptable reliability, even with ulna positive or negative variance. Instability of DRUJ may be indicated when AD/AB is less than 0.25 or BD/AB is less than 0.23.