Partial Neurectomy Research Articles

Partial Tibial Neurectomy for Treatment of Spastic Paresis in a Simmental Calf

Spastic paresis is a progressive neuromuscular disease that usually occurs in calves at the age of 3-5 months. The material of this study was a 3.5-month old female Simmental calf, weighing 87 kg, brought to Selcuk University Faculty of Veterinary Medicine Large Animal Hospital in May 2023 with a complaint of lameness in the right hind leg. Clinical examination revealed contraction and hyperextension in the right hind limb of the calf. There was no swelling or pain in the tarsal or genu joints or other anatomical regions. Radiological examination showed no evidence of degenerative joint disease. A diagnosis of progressive spastic paresis was made on the basis of the clinical findings. Partial neurectomy of the tibial nerve was made to treat the calf with spastic paresis. A 15 cm incision was made over the semimembranous and gluteobiceps muscles to access the area. The tibial nerve innervating the gastrocnemius muscles was then identified and a 1 cm section was resected. This de-innervated the gastrocnemius muscles of the limb and the weight was transferred to the flexor digitorum superfisialis. Postoperatively, the patient was treated with antibiotics and analgesics. In conclusion; in the case of spastic paralysis, pain and contractions related to muscle spasms disappeared after the partial tibial neurectomy operation and the life welfare of the calf increased.

The utility of selective partial neurectomy of the musculocutaneous nerve in children with bilateral spastic elbow.

This study aims to determine the utility of selective partial neurectomy of the musculocutaneous nerve (MCN) in pediatric patients with bilateral spastic elbow. A prospective, cross-sectional, case series study was performed in nine pediatric patients (four females and five males) with bilateral spastic elbow, all with a 11.4-year-old average age, where 18 selective partial neurectomies of the MCN were carried out. They were evaluated with goniometry of both spastic elbows at resting position and active amplitude, and staging spasticity employing the Modified Ashworth Scale (MAS) in the preoperative and postoperative period. The results are reported 1year after surgery. The etiology of the spasticity was secondary to cerebral palsy in eight patients (88.8%) and in one patient (11.11%) secondary to traumatic brain injury. A clinical improvement was observed in goniometry comparing the preoperative and postoperative resting position, a mean preoperative of 44.38 degrees (SD ± 7.61) versus 98.05 degrees (SD ± 24.44), respectively, and preoperative active amplitude a mean of 86.55 degrees (SD ± 15.97) versus the mean postoperative of 47.33 (SD ± 17.86). A relevant decrease on the MAS after surgical intervention was observed, resulting from an average preoperative state according to MAS of 3.78 (SD ± 0.42) to a postoperative state according to MAS of 1.44 (SD ± 0.51), these changes being statistically significant (p ≤ 0.001). No postoperative complications were observed. Selective partial neurectomy of the MCN has shown good results in patients with bilateral spastic elbow in whom antispastic drugs and physical therapy have failed, and has prove permanent effects.

Hyperselective neurectomy for the treatment of upper limb spasticity in adults and children: a prospective study.

Hyperselective neurectomy (HSN) procedures in the spastic upper limb aim to reduce tone by excising some branches of the involved peripheral motor nerves, at the point of entry of each motor ramus into the target muscle. In this prospective study, 42 patients with upper limb spasticity were treated by HSN for the muscles of elbow flexion, forearm pronation and wrist flexion and evaluated for their short-term results (average 6 months) and long-term outcomes (average 31 months). Results at both time points showed an effective reduction of the spastic tone, with no decrease of muscle strength in the operated spastic muscles. Comparison of results between the two time points showed durability of the improvement, which remained statistically significant despite a slight relapse in spasticity. The results of HSN compare favourably with the other techniques of partial neurectomy; however, the technique requires a detailed knowledge of upper limb motor anatomy.Level of evidence: II.

Surgical Outcomes After Microvascular Decompression With Internal Neurolysis and Partial Neurectomy for Patients With Trigeminal Neuralgia and Negative Neurovascular Compression

Abstract INTRODUCTION Microvascular decompression (MVD) is an effective and durable treatment for patients with trigeminal neuralgia (TN) due to neurovascular compression (NVC). In the absence of NVC, the traditional MVD is less effective in achieving long-term pain relief. Internal neurolysis at the root entry zone (REZ) of the trigeminal nerve has been described in the literature; however, there are few reports of long-term outcome after this procedure. Furthermore, this is the first study to combine this procedure with additional partial neurectomy. METHODS This is a retrospective review of the senior author's patients with TN who underwent retrosigmoid craniectomy for MVD with internal neurolysis and partial neurectomy. Primary indications were patients with TN and no evidence of NVC intraoperatively. A total of 9 patients were included in the analysis. Three cases were of recurrent TN. The technique was performed with an 11-blade or arachnoid knife to open the perineurium in a longitudinal fashion at the REZ. A disc dissector was used to comb the fascicles along the longitudinal course, and a partial neurectomy was performed with a microscissors to make three selective cuts into the fascicles at the REZ. Barrow Neurological Institute (BNI) facial pain and numbness scales were used as postoperative assessment. RESULTS At median follow up of 12 mo (range: 2 to 34), 8 of 9 patients (89%) had a BNI-pain score of I (no trigeminal pain, no medications). Two of nine patients (22%) had a BNI-numbness score of I (no numbness); seven (78%) had a BNI-numbness score of II (mild facial numbness that is not bothersome). CONCLUSION Internal neurolysis with partial neurectomy appears to be an effective and potentially durable treatment option for patients with TN (primary or recurrent) without NVC. Larger series with longer follow-up is indicated to further evaluate the utility of this procedure.

Penetrating Offending Vessel, The Most Surgically Demanding Type during Microvascular Decompression Surgery in Hemifacial Spasm

Abstract INTRODUCTION Microvascular decompression (MVD) is the most effective and curative treatment option for neurovascular compression syndrome and it is increasingly performed around the world. This study aimed to identify and describe the most technically difficult cases, which were the patients with penetrating offending vessel through the facial nerve, from our experiences and to give surgical tips for the successful MVD. METHODS Surgical records and intraoperative video of hemifacial spasm patients with penetrating offending vessels were reviewed. Interposition of Teflon felt between nerve and vessel was pursued, and neurectomy was avoided as much as possible. RESULTS Five patients with hemifacial spasm were identified as having a penetrating offending vessel through the facial nerve during the last 5 yr of MVD surgery in our institution. Four AICAs and one PICA were the causative vessels. Partial neurectomy was required in 1 patient. During the median follow-up of 6 mo (range, 1-26), all patients were spasm-free. No patients including the one with partial neurectomy were involved in facial palsy or hearing loss. CONCLUSION MVD in HFS patients with penetrating offending vessel through the facial nerve is the most surgically challenging and demands a high surgical skill. Interposition with Teflon felt is effective and neurectomy should be avoided. Intraoperative monitoring of free-running EMG and abnormal muscle response are helpful to decide the extent of surgery.

Neuralgia due to iliohypogastric nerve injury after inguinal hernioplasty: a case report

BackgroundNeuralgia due to iliohypogastric nerve entrapment from sutures and mesh after inguinal hernioplasty is a rare entity in clinic. Its’ awareness and management remain a clinical challenge.Case presentationWe report a case of 54-year-old male who presented with post-operative pain after 1 month and sensory disturbances of the right lower limb. He underwent partial neurectomy and during the surgery it was found that there was injury to iliohypogastric nerve due to entrapment from sutures and mesh.ConclusionWe hope to strengthen awareness about the importance of the identification of iliohypogastric nerve during inguinal hernioplasty.

Efficacy and Safety of the Babysitter Procedure With Different Percentages of Partial Neurectomy.

After 2 months of denervation, the number of motor units in the muscle decreases; after 6 months of denervation, muscle atrophy and weakness are irreversible and successful nerve reconstruction does not generally restore function. The babysitter procedure was reported to successfully avoid muscle atrophy. One study found that the babysitter procedure with a 40% neurectomy was most suitable; however, the amount of donor nerve that can be borrowed for the babysitter procedure in peripheral nerve injury is unknown. One hundred adult female Sprague-Dawley rats were used in this study. The rats were randomly allocated to 5 groups (groups A-E; n = 20 each). The rats underwent different surgeries based on their grouping. At 6, 12, 18, and 24 weeks after surgery, 5 rats in each group were selected for electrophysiology and muscle force tests. These rats were then killed, and the gastrocnemius and tibialis anterior muscles were harvested for weight measurement and cross-sectional muscle measurement. The results of the effects on the peroneal nerves and tibialis anterior muscles after the babysitter procedure with 40% and 80% neurectomies showed that the functional ability of the recipient nerves was maintained and the muscle was effectively prevented from atrophy, whereas the 20% neurectomy and end-to-side procedures showed relatively poor performance. The results of the effects on the tibial nerve and gastrocnemius muscles after the babysitter procedure with 20% and 40% neurectomies showed that there was little effect on the donor nerve. By contrast, 80% neurectomy strongly and negatively affected the donor nerve. Our results indicate that the babysitter procedure using a donor nerve with a partial neurectomy of 40% was the best choice for effectively treating peripheral (peroneal) nerve injury in rats.

End-to-Side Neurorrhaphy as Schwann Cells Provider to Acellular Nerve Allograft and Its Suitable Application.

Axonal regeneration relies on support from proliferating host Schwann cells (SCs), and previous studies on acellular nerve allografts (ANGs) suggest that axons can regenerate into ANGs within a limited distance. Numerous studies have demonstrated that the supplementation of ANGs with exogenous factors, such as cultured SCs, stem cells, and growth factors, promote nerve regeneration in ANGs. However, there are several problems associated with their utilization. In this study, we investigated whether end-to-side (ETS) neurorrhaphy, which is an axonal provider, could be useful as an SC provider to support axonal elongation in ANGs. We found that ETS neurorrhaphy effectively promoted SC migration into ANGs when an epineurium window combined with partial neurectomy was performed, and the effectiveness increased when it was applied bilaterally. When we transplanted ANGs containing migrated SCs via ETS neurorrhaphy (hybrid ANGs) to the nerve gap, hybrid ANGs increased the number of regenerated axons and facilitated rapid axonal elongation, particularly when ETS neurorrhaphy was applied to both edges of the graft. This approach may represent a novel application of ETS neurorrhaphy and lead to the development of hybrid ANGs, making ANGs more practical in a clinical setting.

Efficacy of the end-to-side neurorrhaphies with epineural window and partial donor neurectomy in peripheral nerve repair: an experimental study in rats.

End-to-side (ETS) neurorrhaphy was a useful tool in peripheral nerve repair and "baby-sitter" procedure. The study was designed to evaluate the long-term efficacy of ETS with epineurial window and 40% partial donor neurectomy in rats. A total of 60 Lewis rats were divided into three groups (n = 20, each group): following peroneal nerve transection, rats in Group A underwent end-to-end neurorrhaphy; rats in Group B underwent ETS neurorrhaphy of the distal peroneal nerve stump to an epineurial window on the tibial nerve; and rats in Group C underwent ETS neurorrhaphy of the distal peroneal nerve stump to the tibial nerve with 40% partial neurectomy. At 6, 12, 18, and 24 weeks after surgery, electrophysiology, muscle tension, myelinated fiber regeneration, cross-sectional area of muscular fiber, and muscle weight were analyzed. Histology exhibited apparently increased number and size of myelinated fibers in peroneal nerves in Group C, compared with those in Group B. More superior recovery was demonstrated in the electrophysiology and axon regeneration of the peroneal nerves, as well as the maintenance of muscle force, wet weight, and fiber size of the anterior tibial muscles in Group C than those in Group B. ETS neurorrhaphy with partial donor neurectomy can achieve higher efficacy in functional and structural recovery of the recipient system. This study provides the evidence of long-term follow-up for the further investigation of ETS neurorrhaphies with different modalities in peripheral nerve repair and in "baby-sitter" procedure.

Changes of the donor nerve in end‐to‐side neurorrhaphies with epineurial window and partial neurectomy: A long‐term evaluation in the rat model

End-to-side (ETS) neurorrhaphy has been applied in the repair of peripheral nerve injuries and in babysitter procedures. However, the long-term changes of donor nerve and muscle after ETS remain unknown. This study was designed to investigate long-term changes in donor nerve and muscle in a rat model. Sixty Lewis rats were equally allocated into three groups of 20 rats. The peroneal nerve was divided. In Group A, end-to-end (ETE) neurorrhaphy was performed. In Group B, ETS was performed to an epineurial window on the tibial nerve. In Group C, ETS was performed to the tibial nerve with 40% partial neurectomy. The following data were obtained at 6, 12, 18, and 24 weeks postoperatively: latency delaying rate (LDR), amplitude recovery rate (ARR), myelinated fiber counts, muscle force and weight, and cross-sectional area of gastrocnemius muscle fibers. The results showed no significant changes of the donor nerve and muscle in Group B. Nerve regeneration was found in the peroneal nerve, and myelinated fiber number was significantly decreased when compared to the nerve with ETE. In Group C, the myelinated axon number in the peroneal nerve was equivalent to the level in ETE repair. However, function and structure of the donor nerve and muscle were significantly impaired in the early postoperative period. Nonetheless, full recovery was observed 24 weeks after surgery. Both ETS with epineurial window and 40% donor nerve neurectomy showed reinnervation of the recipient nerve without structural and functional changes of the donor system in a long-term follow-up. Partial neurectomy may promote recipient nerve regeneration, but at the cost of donor neuromuscular compromises in the early postoperative period. This study provides long-term evidence for further investigation of ETS in peripheral nerve repair and in babysitter procedures.

Medium-term results of arthroscopic debridement and capsulectomy for the treatment of elbow osteoarthritis

We retrospectively reviewed 20 patients (21 elbows) after arthroscopic debridement and capsulectomy of the elbow for primary osteoarthritis. We aimed to see if there was an improvement in pain, function, and range of movement in the medium-term. Outcomes of 20 patients (18 men, 2 women) with primary osteoarthritis of the elbow (21 elbows) operated on by the senior surgeon were reviewed at a mean of 5.5 years postoperatively. Inclusion criteria were patients with undergoing arthroscopic debridement and capsulectomy after failure of previous conservative treatment. Exclusion criteria were patients undergoing additional intra-articular procedures at surgery and patients with post-traumatic or inflammatory arthritis. Mean age was 42 years (range, 22-79 years). Preoperatively, osteoarthritis was classified based on plain x-ray images. Functional outcome was assessed using preoperative and postoperative Disabilities of the Arm, Shoulder and Hand (DASH) scores, Mayo scores, and range of movement. Radiographically, osteoarthritis was assessed as class I in 9 elbows, class II in 10 elbows, and class III in 3 elbows. There was a mean significant improvement in DASH score from 34.0 to 12.7 (P< .05). This was true for all grades of osteoarthritis and significant for classes II and III (P < .05). Mayo scores postoperatively were "excellent" in 11 elbows, "good" in 5, "fair" in 4, and "poor" in 1. Nineteen of the 20 patients said they would have had the surgery again. Arthroscopic debridement and capsulectomy is an effective procedure for patients with primary osteoarthritis of the elbow. We propose this may work as a partial neurectomy to denervate pain sensation in the joint.

Direct neurectomy of the motor branches of the tibial nerve in hemiplegic adults: An assessment with a mean follow-up period of 11 years

IntroductionNeurectomy of the tibial nerve plays a major role in the relief of disabling spasticity, which is refractory to drug treatment and physiotherapy. Although the immediate postoperative results are generally satisfactory, few evaluations of the procedure's long-term efficacy have been published. ObjectiveTo estimate the long-term efficacy of total or partial neurectomy of the motor branches of the tibial nerve (combined with additional orthopaedic surgery in some cases). MethodA descriptive, retrospective study of 25 brain-damaged patients having undergone neurectomy at least 4 years ago. ResultsThe mean post-neurectomy follow-up period was 11 years. Twenty patients became less dependent on the use of walking aids. Of the 18 patients unable to walk barefoot before surgery, 11 could do so after surgery. Of the 12 patients unable to walk on uneven ground before surgery, seven could do so afterwards. The walking distance increased for 20 patients. In 22 cases, the spasticity disappeared immediately after the operation and did not reappear in the long-term. In three other cases, spasticity persisted postoperatively and, in the long-term, affected the soleus (the denervation of which had been incomplete or not performed). Eighty-three percent of the patients were satisfied with the operation's outcome. ConclusionsThe observed maintenance of the benefits of total or partial neurectomy after an average follow-up period of 11 years confirms the value of this procedure. The few mediocre outcomes (observed in cases of partial neurectomy of the soleus) are in agreement with literature reports and emphasize the role of the soleus in this pathology.

Experience with Spinal Cord Stimulation for Treating Intractable Penile Pain after Partial Neurectomy of the Dorsal Penile Nerve

Neuroablation should be performed cautiously because neuropathic pain can occur following denervation of a somatic nerve. A 34-year-old man presented with severe penile pain and allodynia following a selective neurectomy of the sensory nerve that innervated the glans penis for treatment of his premature ejaculation. He was treated with various nerve blocks, including continuous epidural infusion, lumbar sympathetic block and sacral selective transforaminal epidural blocks, as well as intravenous ketamine therapy. However, all of the treatments had little effect on the relief of his pain. We performed spinal cord stimulation as the next therapy. After this therapy, the patient has currently been satisfied for 3 months.

Collateral sprouting occurs following end-to-side neurorrhaphy.

Recent evidence supports the use of end-to-side neurorrhaphy for the treatment of certain peripheral nerve disorders. However, the mechanism by which nerves regenerate following this procedure is still unclear. To address this question, the authors designed a new end-to-side coaptation model in rats in which the donor nerves were uninjured. The regenerated axons at the coaptation site were observed directly using fluorescent dye as the neural tracer. The sciatic nerve from adult Wistar rats was transplanted between the left and right median nerves. Fifteen rats were divided into three groups. In group I, the donor (right median) nerve was sutured end to side to the divided grafted nerve using a noninjury technique. In group II, the aponeurosis of the spinal muscles was harvested and the sciatic and right median nerves were coapted end to side noninjuriously by wrapping them in the excised aponeurosis. In group III, a perineurial window was created and a partial neurectomy was carried out at the suture site, after which the sciatic and right median nerves were sutured end to side. Sixty days after the operation, nerve regeneration was evaluated by recording action potentials in the grafted nerve, by performing electromyography in the flexor muscles in the forearm, and by histological examination. The grafted nerves were fixed and sectioned, the number of regenerated nerve fibers was counted, and axonal diameters were measured. Fluorescent dye crystal was used, in conjunction with confocal microscopy, to observe the regenerated axons at the co-aptation site. The results showed that nerve regeneration had occurred in the animals, as determined electrophysiologically and histologically. Both the right and left flexor muscles of the forearm contracted simultaneously as a result of indirect electric stimulation of the grafted nerve, which suggests that the regenerated nerve was physiologically connected with the donor nerve. Nerve fiber counts did not show any differences among groups (p > 0.05), but axonal diameters were significantly greater in group III than in the other two groups. Fluorescent dye staining revealed the presence of regenerated nerve fibers beyond the coaptation site. In group III, the regenerating nerves were observed within the whole section of the coaptation site and collateral sprouting was found to occur even at a site distal to the suture. From these results, the authors conclude that in end-to-side neurorrhaphy, nerve regeneration occurs by collateral sprouting from the donor nerve.

Amelioration of disease severity by intraarticular hylan therapy in bilateral canine osteoarthritis.

Because of its high molecular weight, the glycosaminoglycan molecule hyaluronan is responsible for the viscoelastic properties of normal synovial fluid. In osteoarthritis, the concentration and molecular weight of hyaluronan in synovial fluid is diminished: this impairs the ability of synovial fluid to effectively lubricate joints, absorb loads, and exert anti-inflammatory effects. Using a bilateral anterior cruciate-ligament transection and partial neurectomy canine model of osteoarthritis, this study examined the effect of viscosupplementation with hylan G-F 20 as a treatment for osteoarthritis. Twelve dogs underwent bilateral arthroscopic anterior cruciate-ligament transections and partial neurectomy of the knee joints. Beginning 1 week after the operation, six dogs received three weekly 500-microl injections of hylan G-F 20 in one knee and a sham injection of saline solution in the contralateral knee (early-treatment group). The remaining six animals underwent the same treatment 2 months following the procedure (late-treatment group). All dogs were killed at 8 months, and both knees were evaluated for gross pathology, histology, and proteoglycan content. In addition, with use of 500-MHz [1H] magnetic resonance spectroscopy, the synovial fluid from both knees was assessed for changes in metabolic profile. Differences in outcome were analyzed with paired t tests. Gross pathological and histological examination revealed significantly less severe changes of osteoarthritis in knees treated with hylan G-F 20 2 months after surgery than in the contralateral untreated knees. Magnetic resonance spectroscopy of the specimens in this late-treatment group showed significantly decreased glucose concentrations and significantly elevated isoleucine levels in the synovial fluid from knees treated with hylan G-F 20 compared with the controls. Previous magnetic resonance spectroscopy had shown that glucose concentrations increase with the onset of osteoarthritis and eventually diminish in end-stage osteoarthritis. The three injections of hylan were given after osteoarthritis was established, and the severity of the disease was ameliorated in the treated knees 6 months after treatment. This occurred although hylan G-F 20 is almost certainly cleared from joints by lymphatics within 4 weeks of injection, suggesting that hylan therapy can retard the progression of osteoarthritis for periods of time extending beyond the intraarticular residence time of the injected molecules and that hylan injections given at relatively early stages of osteoarthritis may have a chondroprotective effect. No changes in outcome were noted in the animals that received hylan G-F 20 immediately following surgery.

Ultrastructure of early axonal regeneration in an end-to-side neurorrhaphy model.

The ultrastructure of the early regenerative response in an end-to-side neurorrhaphy rat model was studied using transmission electron microscopy. The ipsilateral saphenous nerve was grafted to the sciatic nerve under the following conditions: Group 1, the epineurium and perineurium of the sciatic nerve remained intact; Group 2, an epineurial and perineurial window was created at the site of the lateral neurorrhaphy; Group 3, the same as in Group 2 and, in addition, the sciatic nerve sustained a partial neurectomy. Rats were perfused through the heart with fixative containing 2 percent paraformaldehyde and 2.5 percent glutaraldehyde in 0.1 M cacodylate buffer (pH 7.4) at 4, 8, 12, 24 and 48 hr after surgery. In Group 1, no regenerating axons were observed and the myelin sheath in the donor nerve did not demonstrate any degenerative changes through 48 hr. In Group 2, an increased diameter of the unmyelinated axons and growth cones was observed in the donor nerve proximal to the coaptation site after 12 hr. Degenerative changes in the myelin sheath were observed after 12 hr within the several layers under the coaptation site. In Group 3, many growth cone-like structures were observed in the area proximal to the coaptation site after 12 hr. After 24 hr, proximal regenerating axons elongated to the coaptation site and, at 48 hr, many regenerating nerves grew inside the Schwann cell basement membrane of the graft nerve. These results indicate that the perineurial window and nerve graft are the critical conditions for inciting nerve regeneration in the donor nerve.

Efficacy of the "baby-sitter" procedure after prolonged denervation.

This study was undertaken to evaluate whether 40 percent of the hypoglossal nerve, which showed optimal efficacy in restoring orbicularis oculi muscle (OOM) function after different percentages of partial neurectomy in a previous study would be effective after prolonged denervation time. Twenty Sprague-Dawley rats were divided into four groups. In first-stage surgery the left facial nerve of all animals was transected at the level of the stylomastoid foramen and main zygomatic branch. Group A (controls) consisted of animals with only left facial nerves transected (no repair). In Groups B, C, and D the facial nerve was transected and the facial musculature was denervated for a period of 4, 8, and 12 weeks respectively. During a second-stage procedure, a 40 percent neurectomy was performed on the hypoglossal nerve. Subsequently, a nerve transfer was performed by coaptations of a saphenous nerve graft to the neurectomized hypoglossal nerve and the main zygomatic branch of the facial nerve that innervated the OOM. Behavioral analysis of blink reflex, electrophysiology, and axon and motor end-plate counts in Groups B, C, and D showed superior results compared to Group A. There was no statistically significant difference observed among Groups B, C, and D (p > 0.05). Despite the diminished number of axons in the zygomatic branch and motor end-plates in the orbicularis oculi muscle after 12 weeks of denervation, there was still sufficient muscle target recovery to effect some eye closure in all groups except the controls. This study demonstrated in this model that the 40 percent partial neurectomy of the XII to VII component of the "baby-sitter" procedure was effective even after prolonged denervation.

Gains and losses of the XII-VII component of the "baby-sitter" procedure: a morphometric analysis.

The classic hypoglossal transfer to the facial nerve is invariably followed by complications caused by tongue atrophy. In 1984, Terzis introduced the "baby-sitter" procedure which involved a formal cross-facial procedure, in addition to partial neurectomy of the hypoglossal nerve, and an end-to-side coaptation with the ipsilateral facial nerve. This reported study provides, for the first time, quantification of the number of hypoglossal motor fibers needed to successfully restore eye sphincter function, using an end-to-side coaptation with preservation of the tongue. Thirty adult Sprague-Dawley rats were divided into six groups: control, denervated, perineurial window, 20 percent partial neurectomy (PN), 40 percent PN, and 80 percent PN. The procedure involves interposing a nerve graft (saphenous) between the partially severed XII nerve and the upper zygomatic branch of the facial nerve. Evaluation of the behavioral data (blink reflex) revealed good-to-superb return of the blinking mechanism in the 40 percent group, without significant tongue atrophy. Electrophysiologic data in the 40 percent neurectomy group demonstrated superiority to the other groups. Quantitative axonal morphometry of the coaptation sites and graft, as well as motor end-plates of the orbicularis oculi muscle and tongue showed the 40 percent partial neurectomy group to be the optimal group.

A new animal model to investigate axonal sprouting after end-to-side neurorrhaphy.

End-to-side neurorrhaphy is a technique that may provide a solution for the problem of distal target reinnervation without injury to the original donor nerve. The technique drew extensive attention after Viterbo reported his experiments in 1992; however, to date, the animal models used to elucidate the process of lateral axon sprouting had the disadvantage of substantial injury to the donor nerve, raising questions about the origin of axons reinnervating the nerve graft. In this report, a new model in the rat is introduced, in which the donor nerve is not damaged and an additional target can be innervated via a nerve graft. The saphenous nerve represents the axonal conduit; the proximal end is coapted end-to-side to the sciatic nerve at the site of a perineurial window. The distal end is passed through the adductor muscles and coapted distally in an end-to-end fashion with the obturator nerve. In one group, a partial neurectomy was performed at the site of coaptation, which led to a lower Sciatic Functional Index (SFI). In the second group, the creation of a perineurial window yielded a normal SFI after end-to-side neurorrhaphy. Compared to the partial neurectomy group, the perineurial window end-to-side neurorrhaphy resulted in significantly less axons in the graft. The new model has the following advantages: (a) minimal injury to the donor nerve; (b) provision of a single additional target (gracilis) whose functional recovery can be assessed morphologically and behaviorally; (c) an opportunity to understand lateral sprouting by providing a non-injury model in which axonal invasion of the graft can originate from nodal axonal outgrowth; and (d) establishment of a noninjury model that can have widespread clinical applications.

Radiographic comparison of adductor procedures in cerebral palsied hips.

Hip muscle imbalance in cerebral palsy may cause subluxation or dislocation. Pelvic radiographs were used to assess hip stability in 40 affected hips before and after open adductor surgery. Preoperative rates of hip migration were determined from radiographs using the center-edge angle and migration percentage. Either an open adductor tenotomy with partial obturator neurectomy or a posterior adductor transfer was performed. Follow-up averaged 5 years, with a reversal of preoperative lateral hip migration in 36 of 40 hips. There was no statistically significant difference in the radiographic outcome of the two procedures. Lateral hip migration can be arrested or reversed with properly timed hip adductor surgery.