ABSTRACT
This study aimed to investigate the reconstruction of the thumb and finger extension function in patients with middle and lower trunk root avulsion injuries of the brachial plexus.From April 2010 to January 2015,we enrolled in this study 4 patients diagnosed with middle and lower trunk root avulsion injuries of the brachial plexus via imaging tests,electrophysiological examinations,and clinical confirmation.Muscular branches of the radial nerve,which innervate the supinator in the forearm,were transposed to the posterior interosseous nerve to reconstruct the thumb and finger extension function.Electrophysiological findings and muscle strength of the extensor pollicis longus and extensor digitorum communis,as well as the distance between the thumb tip and index finger tip,were monitored.All patients were followed up for 24 to 30 months,with an average of 27.5 months.Motor unit potentials (MUP) of the extensor digitorum communis appeared at an average of 3.8 months,while MUP of the extensor pollicis longus appeared at an average of 7 months.Compound muscle action potential (CMAP) appeared at an average of 9 months in the extensor digitorum communis,and 12 months in the extensor pollicis longus.Furthermore,the muscle strength of the extensor pollicis longus and extensor digitorum communis both reached grade Ⅲ at 21 months.Lastly,the average distance between the thumb tip and index finger tip was 8.8 cm at 21 months.In conclusion,for patients with middle and lower trunk injuries of the brachial plexus,transposition of the muscular branches of the radial nerve innervating the supinator to the posterior interosseous nerve for the reconstruction of thumb and finger extension function is practicable and feasible.
ABSTRACT
In order to investigate the biological function of transforming growth factor-β1 (TGF-β1)during fibrosis in denervated skeletal muscle,we recruited sciatic nerve injury model of SD rats in which denervated gastrocnemius was isolated for analysis.At different time points after operation,denervated muscle was examined by several methods.Masson trichrome staining showed morphological changes of denervated skeletal muscle.Quantitative RT-PCR detected the rapid increase of TGF-β1 expression at mRNA level after nerve injury.It was found that a peak of TGF-β1 mRNA expression appeared one week post-operation.The expression of collagen Ⅰ (COL Ⅰ ) mRNA was up-regulated in the nerve injury model as well,and reached highest level two weeks post-injury.Immunoblot revealed similar expression pattern of TGF-β1 and COL Ⅰ in denervated muscles at protein level.In addition,we found that the area of the gastrocnemius muscle fiber was decreased gradually along with increased interstitital fibrosis.Interestingly,this pathological change could be prevented,at least partly,by local injection of TGF-β1 antibodies,which could be contributed to the reduced production of COL Ⅰ by inhibiting function of TGF-β1.Taken together,in this study,we demonstrated that the expression of TGF-β1 was increased significantly in denervated skeletal muscle,which might play a crucial role during muscle fibrosis after nerve transection.