Targeted Muscle Reinnervation in the Upper Arm: A Functional Anatomical Study.

BACKGROUND: The aim of this study was to accurately locate the neural fascicle controlling hand movement in the upper arm, to enhance expression of motor intention after targeted muscle reinnervation. METHODS: The right sides of the median, ulnar and radial nerves were dissected from distal to proximal in 6 fresh cadaver specimens. The sectional location and diameter of the functional fascicle were measured at 10 and 20 cm below the acromion. The diameter of the main muscle branches of muscle reinnervation target muscles was measured. RESULTS: The median nerve branch of finger and wrist flexion was mainly located between the 9 and 12 o'clock positions in the plane 10 and 20 cm below the acromion, where the diameter of the nerve fascicle was 2.07 and 2.04 mm, respectively. The ulnar nerve branch of finger and wrist flexion was mainly located between the 8 and 12 o'clock positions, with a diameter of respectively 1.80 and 1.99 mm. The radial branch of finger and wrist extension was mainly located between the 10 and 2 o'clock positions in the plane 10 cm below the acromion and between 6 and 12 o'clock in the plane 20 cm below the acromion, with a diameter of respectively 2.57 and 3.03 mm. CONCLUSIONS: The nerve fascicles innervating the flexor and extensor fingers were distributed in relatively constant regions of the median, ulnar and radial nerve trunks, and their diameters closely matched the muscle branches of the target muscle.

Direct Repair of ruptured nerve stump to middle trunk for restoration of extrinsic finger extension in total brachial plexus injuries.

BACKGROUND: Attempts to restore independent hand function in total brachial plexus injuries (TBPI) have often failed due to the inconsistent results of fingers extension reconstruction. An innovative technique is described to achieve this by direct neurorrhaphy of residual (ruptured) roots with the middle trunk. METHODS: Direct coaptation of the ruptured roots to the middle trunk and, simultaneously, transferring the anterior division of the middle trunk to the posterior division of lower trunk was performed in 64 patients of TBPI. The return of extension of the elbow, wrist and fingers were monitored. RESULTS: The excellent and good muscle strength of finger extension was noted in 45.3% cases. The patients were divided into group A (>32 years) and group B (≤32 years) according to ROC curve analysis. The difference of excellent and good rates of finger and wrist extension muscle strengths between the two groups was statistically significant (χ 2=4.635, P=0.031 χ 2=6.615, P=0.010). CONCLUSIONS: Direct neurorrhaphy of ruptured nerve root stumps with the middle trunk could achieve satisfactory results for finger extension in TBPI for patients ≤32 years old. Long nerve defects (4-6.5 cm) could be overcome by freeing the nerve and adducting the arm against the trunk.

Muscle redistribution technique for expressing motion intention in patients with wrist-level amputation.

This study reports the preliminary results of a technique for redistributing muscles at the wrist in the stump of hand amputees by suturing the tendons to the dermis. The technique has the potential to improve control of hand prostheses by detecting movement intentions.

Parallel reconstruction of vascularized fibula autograft for treatment of complications after resection of malignant tumor from the thigh.

SUMMARY: The authors herein introduce a modification of parallel reconstruction with a vascularized fibula autograft (VFA) for cases of femur allograft complications. Conventional parallel reconstruction, in which the fibula with its vascular pedicle is placed on the medial side of the femur and allogeneic bone, may be an effective means to solve the allograft complications. However, the limited contact area between the fibula and femur/allogeneic bone can affect the bone healing ability. Furthermore, the rigid internal fixation method for the VFA may cause stress shielding and result in bone resorption. The authors propose the use of modified parallel reconstruction of the VFA with fibula expansion and titanium cable fixation for patients with allograft-host junction nonunion, allogeneic bone fracture, and femoral shaft fracture after surgical removal of a malignant tumor from the thigh. The modified parallel reconstruction has been performed on 5 patients (2 patients underwent fibular expansion). All 5 patients with 7 nonunion of allograft-host junction or fracture were followed up 33.2 months. The length of fibular graft is 10-20cm, with an average of 15.0 cm. The union rate of allograft-host junction and fracture was 100% (7/7), and the union time 15.9 months. This modified parallel reconstruction technique can achieve satisfactory union in treatment of the above complications.

Quantitative Analysis of Deformity in Digital Model of Congenital Radioulnar Synostosis.

OBJECTIVE: The deformity of congenital radioulnar synostosis is quite complicated and difficult. This study aims to find out the related factors of the "forearm rotation angle" (FR) which relate to the severity of congenital radioulnar synostosis (CRUS), and try to quantify the internal relations of each deformity and help to understand the reconstruction method in surgery treatment of this disease. METHODS: This study is case series research. We established 48 digital three-dimensional forearm bone models of 48 patients with congenital radioulnar synostosis classified as Cleary and Omer type 3. All the patients were treated at our institution from January 2010 to June 2016. In total, 10 independent deformities (the rotation angle of forearm; the internal rotation, radial, and dorsal angulation of radius and ulna; the relative length of osseous fusion at PRUJ; the relative dislocation distance of distal radioulnar joint; the relative area of proximal radial epiphysis) involved in the CRUS complex deformity were measured. Pearson correlation analysis for each deformity which was mentioned above was performed, and multivariate linear regression analysis was also performed with FR as the dependent variable and the other deformities as the influential factors. RESULTS: The "dorsal angle of radius" (DAR, 21.69° ± 21.55°) had the strongest correlation with the FR (79.72° ± 40.39°), the Pearson correlation coefficient was 0.601 (p < 0.01), the internal rotation angle of the radius (IRAR, 82.69° ± 54.98°) had a moderate correlation with FR, the Pearson correlation coefficient was 0.552 (p < 0.01). A forearm deformity equation was established: FR = 35.896 + 0.271 DAR + 0.989 IRAR. CONCLUSION: The dorsal angulation deformity of radius may be the most important deformity that effects the severity of CRUS and should be correct in the first place during reconstruction operation.

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.