Outcomes of Sciatic Nerve Injury Repairs: A Systematic Review.

Background: The objective of this study was to investigate the surgical repair techniques and the outcomes of sciatic nerve injuries in traumatic wounds. Methods: A literature search was conducted using the following keywords:sciatic, nerve, repair, technique, conduit, graft, reconstruction, outcome, rehabilitation, recovery, function, surgery, and NOT anesthesia. Results: In total, 715 studies were retrieved. After abstract review, 13 articles fit the criteria. A total of 2627 repairs were carried out, including nerve grafts (n = 953), suture (n = 482), and neurolysis (n = 1192). Six studies reported good motor outcome, and good sensory outcome was reported across 2 studies. The thigh region accounted for 81.5% of lesions. Sciatic, peroneal, and tibial nerves were all equally affected. Gunshot wounds were the most common mechanism of injury (22.6%). Conclusions: The cumulative evidence demonstrates sciatic nerve injury repair has poor motor and sensory outcomes. This study shows there is a lack of standardized outcome measures, making comparisons very difficult. Graft lengths of <4 cm within the intermediate region yielded more successful outcomes. Further higher quality studies of nerve transfers in the lower limbs are needed to determine the optimal repair to restore sciatic nerve function.

Comparação de diferentes comprimentos de onda do laser de baixa potência no sóleo de ratos Wistar após lesão nervosa / Comparación entre diferentes longitudes de onda de láser de baja potencia en el sóleo de ratas Wistar tras lesión nerviosa / Comparison of different low-level laser therapy wavelengths in the soleus of Wistar rats after nerve injury

RESUMO Os músculos esqueléticos podem ser afetados por lesões do sistema nervoso periférico, levando a fraqueza e atrofia muscular. Na tentativa de recuperar a funcionalidade dos músculos, existem vários recursos terapêuticos utilizados, dentre os quais o laser de baixa potência (LBP). Este estudo comparou o efeito do LBP em dois comprimentos de onda (660 nm e 830 nm), em características morfológicas do tecido muscular após axonotmese de nervos isquiáticos de ratos Wistar. Para tanto, foram utilizados 32 ratos Wistar, divididos em quatro grupos, sendo G1 (controle), G2 (lesão), G3 (lesão e tratamento com LBP de 660 nm) e G4 (lesão e tratamento com LBP de 830 nm). Os animais de G2, G3 e G4 foram submetidos à lesão do nervo isquiático e, três dias após a lesão, G3 e G4 realizaram tratamento com LBP de 660 nm e 830 nm, respectivamente. Após o tratamento, todos os animais foram eutanasiados e os músculos sóleos coletados para confecção das lâminas histológicas, visando a realização de análises morfológicas do tecido. Constatou-se que os animais submetidos à lesão sofreram alterações morfológicas na fibra, resultando em sua atrofia. Foi percebido também que o LBP com comprimento de onda de 830 nm apresentou ligeiros sinais de recuperação das características morfométricas analisadas.

RESUMEN Las lesiones en el sistema nervioso periférico pueden afectar los músculos esqueléticos y provocar debilidad y atrofia muscular. Para recuperar la funcionalidad de los músculos, se utilizan varios recursos terapéuticos, entre los cuales el láser de baja potencia (LBP). Este estudio comparó el efecto del LBP en dos longitudes de onda (660 nm y 830 nm) sobre las características morfológicas del tejido muscular después de la axonotmesis de los nervios ciáticos en ratas Wistar. Para ello, se utilizaron 32 ratas Wistar, divididas en cuatro grupos: G1 (control), G2 (lesión), G3 (lesión y tratamiento con LBP de 660 nm) y G4 (lesión y tratamiento con LBP de 830 nm). Los animales de G2, G3 y G4 se sometieron a lesión del nervio ciático y, tres días después de la lesión, el G3 y G4 se sometieron al tratamiento con LBP de 660 nm y 830 nm, respectivamente. Después del tratamiento, todos los animales fueron sacrificados y se recogieron los músculos sóleos para la preparación de placas histológicas, con el fin de realizar análisis morfológicos del tejido. Se encontró que los animales sometidos a lesión sufrieron cambios morfológicos en la fibra, lo que resultó en atrofia. También se observó que el LBP con la longitud de onda de 830 nm presentó leves signos de recuperación de las características morfométricas analizadas.

ABSTRACT Skeletal muscles may be affected by peripheral nervous system injuries, leading to muscle weakness and atrophy. Several therapeutic resources may be used in the attempt to recover the functionality of muscles, such as low-level laser therapy (LLLT). This study compared the effect of LLLT of two wavelengths (660 nm and 830 nm) on morphological characteristics of muscle tissue after axonotmesis of ischiatic nerves of Wistar rats. A total of 32 Wistar rats were divided into four groups: G1 (control), G2 (injury), G3 (injury and treatment with 660 nm LLLT) and G4 (injury and treatment with 830 nm LLLT). G2, G3, and G4 animals were submitted to sciatic nerve damage and, three days after the injury, G3 and G4 were treated with LLLT of 660 nm and 830 nm, respectively. After the treatment, all animals were euthanized, and the soles muscles were collected to perform morphological analyzes of the tissue using histological slides. We verified that animals submitted to the lesion underwent morphological changes in the fiber, resulting in their atrophy. We also noticed that LLLT with a wavelength of 830 nm presented slight signs of recovery of the morphometric characteristics analyzed.

Tenotomy of the Gluteus Maximus in Total Hip Arthroplasty with Prevention of Sciatic Nerve Injury.

The authors report a single case of complex primary hip total arthroplasty in a 34-year-old female patient with a 5.5 cm lower limb dysmetria, in whom a maximum gluteus tenotomy was performed in order to prevent sciatic nerve injury. The surgery was performed under electroneurophysiological monitoring of the fibular and tibial branches of the sciatic nerve, collecting pretenotomy, posttenotomy, and postarthroplasty reduction data. The findings demonstrate that the maximum gluteus tenotomy improved the motor response of the fibular component of the sciatic nerve.

Tenotomy of the Gluteus Maximus in Total Hip Arthroplasty with Prevention of Sciatic Nerve Injury / Tenotomia do glúteo máximo em artroplastia total do quadril como prevenção de lesão do nervo ciático

Abstract The authors report a single case of complex primary hip total arthroplasty in a 34-yearold female patient with a 5.5 cm lower limb dysmetria, in whom a maximum gluteus tenotomy was performed in order to prevent sciatic nerve injury. The surgery was performed under electroneurophysiological monitoring of the fibular and tibial branches of the sciatic nerve, collecting pretenotomy, posttenotomy, and postarthroplasty reduction data. The findings demonstrate that the maximum gluteus tenotomy improved the motor response of the fibular component of the sciatic nerve.

Resumo Os autores relatam um único caso de artroplastia total de quadril primária complexa em uma paciente do sexo feminino de 34 anos, com dismetria de membros inferiores de 5,5 cm, na qual foi feita tenotomia do glúteo máximo a fim de prevenir lesão do nervo ciático. Tal cirurgia foi feita sob monitoração eletroneurofisiológica dos ramos fibular e tibial do nervo ciático. Foramcoletados dados pré-tenotomia, pós-tenotomia e pós-redução artroplástica. Os achados demonstram que a tenotomia do glúteo máximo melhorou a reposta motora do componente fibular do nervo ciático.

Delay of neuropathic pain sensitization after application of dexamethasone-loaded implant in sciatic nerve-injured rats

Neuroimmune interactions underlying the development of pain sensitization in models of neuropathic pain have been widely studied. In this study, we evaluated the development of allodynia and its reduction associated with peripheral antineuroinflammatory effects induced by a dexamethasone-loaded biodegradable implant. Chronic constriction injury (CCI) of the sciatic nerve was performed in Wistar rats. The electronic von Frey test was applied to assess mechanical allodynia. The dexamethasone-loaded implant was placed perineurally at the moment of CCI or 12 days after surgery. Dorsal root ganglia (DRG; L4-L5) were harvested and nuclear extracts were assayed by Western blot for detection of nuclear factor (NF)-κB p65/RelA translocation. Dexamethasone delivered from the implant delayed the development of allodynia for approximately three weeks in CCI rats when the implantation was performed at day 0, but allodynia was not reversed when the implantation was performed at day 12. NF-κB was activated in CCI rat DRG compared with naïve or sham animals (day 15), and dexamethasone implant inhibited p65/RelA translocation in CCI rats compared with control. This study demonstrated that the dexamethasone-loaded implant suppresses allodynia development and peripheral neuroinflammation. This device can reduce the potential side effects associated with oral anti-inflammatory drugs.

Sericin and swimming on histomorphometric parameters of denervated plantar muscle in Wistar rats / Sericina e natação sobre parâmetros histomorfométricos de músculo plantar desnervado de ratos Wistar

Abstract Objective To analyze the combined effects of the silk protein sericin and swimming exercise on histomorphometry of the plantar muscle in Wistar rats. Methods Forty adult rats were randomly allocated into 5 groups comprising 8 animals each, as follows: Control, Injury, Sericin, Swim, and Swim plus Sericin. Three days after crushing of the sciatic nerve the rats in the Swim and Swim plus Sericin Groups were submitted to swimming exercise for 21 days. Rats were then euthanized and the plantar muscle harvested and processed. Results Cross-sectional area, peripheral nuclei and muscle fiber counts, nucleus/fiber ratio and smallest muscle fiber width did not differ significantly between groups. Morphological analysis revealed hypertrophic fibers in the Swim Group and evident muscle damage in the Swim plus Sericin and Injury Groups. The percentage of intramuscular collagen was apparently maintained in the Swim Group compared to remaining groups. Conclusion Combined treatment with sericin and swimming exercise did not improve muscle properties. However, physical exercise alone was effective in maintaining intramuscular connective tissue and preventing progression of deleterious effects of peripheral nerve injury.

RESUMO Objetivo Analisar o efeito da proteína sericina associada ao exercício físico de natação na histomorfometria do músculo plantar de ratos Wistar. Métodos Foram utilizados 40 ratos adultos divididos aleatoriamente em 5 grupos, com 8 animais cada: Controle, Lesão, Sericina, Natação, Natação e Sericina. Três dias após a compressão do nervo isquiático, os Grupos Natação e Exercício e Sericina foram submetidos ao exercício físico de natação durante 21 dias. Após, os animais foram sacrificados, e o músculo plantar foi processado. Resultados Não houve diferença da área da secção transversa entre os grupos, quantidade de núcleos periféricos, quantidade de fibra, relação núcleo/fibra e diâmetro menor. A análise morfológica revelou que no Grupo Natação ocorreu hipertrofia das fibras, assim como nos Grupos Exercício e Sericina e Lesão, o dano muscular foi evidente. O percentual de conjuntivo intramuscular parece ter sido mantido no Grupo Exercício em relação aos demais grupos. Conclusão A associação da proteína sericina e exercício físico de natação não foi eficiente na melhora das propriedades musculares, embora a aplicação do exercício físico tenha sido eficiente na manutenção do conjuntivo intramuscular, e no não agravamento dos efeitos deletérios consequentes da lesão nervosa periférica.

Sciatic nerve injuries following femoral shaft fractures: Does the time interval from injury to surgery matter?

OBJECTIVES: Sciatic nerve injuries following fractures of femoral shaft are uncommon complications. The patients with such deficits present with sciatic nerve palsy. A few cases of sciatic nerve injuries secondary to femoral shaft fractures have thus far been reported. If such patients fail to improve spontaneously, they may require surgical exploration. The present paper gives an account of surgical exploration in patients presenting with sciatic nerve injuries following femoral shaft fractures. PATIENTS AND METHODS: Clinical outcomes were assessed in 14 patients undergoing surgical exploration of sciatic nerve injuries following femoral shaft fractures. RESULTS: There was a significant negative correlation between the time interval from injury to surgery and motor function recovery. Furthermore, a negative but non-significant correlation was seen between the time interval from injury to surgery and sensory recovery. CONCLUSIONS: Early exploration of sciatic nerve injuries following femoral shaft fractures can be beneficial if the nerve injury does not improve spontaneously.

The role of spinal cord p300 in chronic constriction nerve injury-induced neuropathic pain in rats / 中国医师杂志

Objective To explore the role of spinal cord p300 in neuropathic pain induced by chronic constriction nerve injury (CCI) in rats.Methods Thirty two Sprague-Dawley (SD) rats were randomly divided into sham and CCI groups,14 days after surgery,immuno-fluorescence staining and Western blot were used to detect distribution and expression of p300 protein.After rats were successfully implanted with an intrathecal catheter and accepted CCI surgery,another 24 rats were randomly divided into three groups (n =8):dimethyl sulfoxide (DMSO) group,p300 acetyltransferase inhibitor C646 group,and control C37 group.Each rat were administered through the intrathecal catheter from day 7 to 14 and mechanical withdraw threshold were tested.Results (1) The p300 positive cells were detected mainly in neurons,and p300 protein in spinal cord of CCI group were significantly higher than sham group (P ＜0.05).(2) C646 alleviated significantly neuropathic pain in rats,without significant changes in pain threshold after injection of C37 and DMSO.Conclusions The p300 protein in spinal cord was involved in the development of neuropathic pain in rats,the mechanism may be referred to its acetyltransferase activity.

Effect of lentiviral vector-mediated GDNF up-regulation on neuropathic pain of chronic constriction injury rats / 中国医师杂志

Objective To investigate the effect of intrathecal injection of lentiviral vector-mediated up-regulation of glial cell line-derived neurotrophicfactor (GDNF) on neuropathic pain of chronic constriction injury (CCI) rats.Methods The CCI model was prepared by ligating the sciatic nerve of Sprague-Dawley (SD) rats.Seven days after CCI modeling,a single intrathecal injection of lentiviral vectors (LV)-GDNF was given.Before CCI and 3,5,7,14,and 21 days after CCI modeling,the mechanical pain threshold was tested in rats,and 21 days after surgery,Western blot was used to detect the expression of GDNF protein.Results On 21 days after CCI modeling,GDNF expression was reduced compared to sham group.After intrathecal injection of LV-GDNF,GDNF expression was up-regulated in the spinal cord,and CCI-induced mechanical hyperalgesia in rats was alleviated.Conclusions Intrathecal injection LV-GDNF can up-regulate the expression of GDNF and alleviate neuropathic pain in CCI rats.