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Objective: The common fibular nerve (CFN) is the most frequently injured nerve in the lower limbs. Surgical management is necessary in approximately two thirds of patients and includes neurolysis, suture, graft repair, or nerve transfer. The distal sural nerve is the preferred donor for grafting, but it is not without complications and requires a second incision. We sought to study the surgical anatomy of the lateral sural cutaneous nerve (LSCN) with the aim of repairing CFN injuries through the same incision and as a potential source for grafting in other nerve injuries., Methods: The popliteal fossa was dissected in 11 lower limbs of embalmed cadavers to study LSCN variations. Four patients with CFN injuries then underwent surgical repair by LSCN grafting using the same surgical approach., Results: At the medial margin of the biceps femoris, the LSCN emerged from the CFN approximately 8.15 cm above the fibular head. The LSCN ran longitudinally to the long axis of the popliteal fossa, with an average of 3.2 cm medial to the fibular head. The mean LSCN length and diameter were 9.61 cm and 3.6 mm, respectively. The LSCN could be harvested in all patients for grafting. The mean graft length was 4.4 cm. Motor function was consistently recovered for foot eversion but was recovered to a lesser extent for dorsiflexion and toe extension. All patients recovered sensitive function (75% of S3). Hypoesthesia was recognized at the calf., Conclusions: LSCN harvest is a viable alternative for nerve grafting, especially for repairing short CFN injuries, thereby avoiding the need for a second incision., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Entubulating devices to repair peripheral nerve injuries are limited in their effectiveness particularly for critical gap injuries. Current clinically used nerve guidance conduits are often simple tubes, far stiffer than that of the native tissue. This study assesses the use of poly(glycerol sebacate methacrylate) (PGSm), a photocurable formulation of the soft biodegradable material, PGS, for peripheral nerve repair. The material was synthesized, the degradation rate and mechanical properties of material were assessed and nerve guidance conduits were structured via stereolithography. In vitro cell studies confirmed PGSm as a supporting substrate for both neuronal and glial cell growth. Ex vivo studies highlight the ability of the cells from a dissociated dorsal root ganglion to grow out and align along the internal topographical grooves of printed nerve guide conduits. In vivo results in a mouse common fibular nerve injury model show regeneration of axons through the PGSm conduit into the distal stump after 21 days. After conduit repair levels of spinal cord glial activation (an indicator for neuropathic pain development) were equivalent to those seen following graft repair. In conclusion, results indicate that PGSm can be structured via additive manufacturing into functional NGCs. This study opens the route of personalized conduit manufacture for nerve injury repair., Statement of Significance: This study describes the use of photocurable of Poly(Glycerol Sebacate) (PGS) for light-based additive manufacturing of Nerve Guidance Conduits (NGCs). PGS is a promising flexible biomaterial for soft tissue engineering, and in particular for nerve repair. Its mechanical properties and degradation rate are within the desirable range for use in neuronal applications. The nerve regeneration supported by the PGS NGCs is similar to an autologous nerve transplant, the current gold standard. A second assessment of regeneration is the activation of glial cells within the spinal cord of the tested animals which reveals no significant increase in neuropathic pain by using the NGCs. This study highlights the successful use of a biodegradable additive manufactured NGC for peripheral nerve repair., (Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Peroneal nerve palsy is the most common entrapment neuropathy of the lower extremity. Numerous etiologies have been identified; however, compression remains the most common cause. Although injury to the nerve may occur anywhere along its course from the sciatic origin to the terminal branches in the foot and ankle, the most common site of compressive pathology is at the level of the fibular head. The most common presentation is acute complete or partial foot drop. Associated numbness in the foot or leg may be present, as well. Neurodiagnostic studies may be helpful for identifying the site of a lesion and determining the appropriate treatment and prognosis. Management varies based on the etiology or site of compression. Many patients benefit from nonsurgical measures, including activity modification, bracing, physical therapy, and medication. Surgical decompression should be considered for refractory cases and those with compressive masses, acute lacerations, or severe conduction changes. Results of surgical decompression are typically favorable. Tendon and nerve transfers can be used in the setting of failed decompression or for patients with a poor prognosis for nerve recovery.

Objective: To explore the feasibility of transposition of the proximal motor branches from tibial nerve (TN) as direct donors to suture the deep peroneal nerve (DPN) so as to provide a basis for surgical treatment of high fibular nerve injury., Methods: Nineteen lower limb specimens were selected from 3 donors who experienced high-level amputation (2 left limbs and 1 right limb) and 8 fresh frozen cadavers (8 left limbs and 8 right limbs). The length and diameter of the three motor branches from TN (soleus, medial gastrocnemius, and lateral gastrocnemius) and the distance from the initial points to the branch point of the common peroneal nerve (CPN), as well as the length and diameter of the noninvasive separated bundles of DPN, then the feasibility of tensionless suturing between the donor nerves and the DPN bundle was evaluated. At last, part of the nerve tissue was cut out for HE and Acetylcholine esterase staining observation and the nerve fiber count., Results: Gross anatomic observation indicated the average distance from the initial points of the three donor nerves to the branch point of the CPN was (71.44 ± 2.76) (medial gastrocnemius), (75.66 ± 3.20) (lateral gastrocnemius), and (67.50 ± 3.22) mm (soleus), respectively. The three donor nerves and the DPN bundles had a mean length of (31.09 ± 2.01), (38.44 ± 2.38), (59.18 ± 2.72), and (66.44 ± 2.85) mm and a mean diameter of (1.72 ± 0.08), (1.88 ± 0.08), (2.10 ± 0.10), and (2.14 ± 0.12) mm, respectively. The histological observation showed the above-mentioned four nerve bundles respectively had motor fiber number of 2,032 ± 58, 2.186 ± 24, 3,102 ± 85, and 3,512 ± 112. Soleus nerve had similar diameter and number of motor fibers to DPN bundles (P > 0.05), but the diameter and number of motor fibers of the medial and lateral gastrocnemius were significantly less than those of DPN bundles (P < 0.05)., Conclusion: All of the three motor branches from TN at popliteal fossa can be used as direct donors to suture the DPN for treating high CPN injuries. The nerve to the soleus muscle should be the first choice.

Objective: Ultrasound (US) and neurophysiological examination are useful tools in the evaluation of common fibular mononeuropathy. There is only a report comparing US and electrophysiological parameters in patients with common fibular nerve (CFN) conduction block at fibular head. We investigated the correlation between US and neurophysiologic findings in this condition., Methods: We retrospectively reviewed patients with CFN assessed in our lab during last 2 years. Each patient underwent to clinical, neurophysiological and ultrasound evaluations. Cross sectional area (CSA) of CFN at fibular head was assessed., Results: Twenty-four patients were included. Motor nerve conduction study showed a reduction of distal compound muscle action potential (CMAP) amplitude in 10 patients (mean 1.3 mV). US showed an increased CSA in 10 patients. Statistical analysis revealed a strong correlation between the increased CSA and the CMAP reduction of CFN., Conclusion: Our data suggest that usually US examination is normal in CFN conduction block at fibular head. However the association with axonal damage is frequently accompanied by an increase of CSA., Significance: Ultrasound evaluation may represent a powerful diagnostic/prognostic tool in cases with CPN conduction block at fibular head because it usually shows normal pattern in pure conduction block and increase of CSA in associated axonal damage., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Introduction: Nowadays, the total hip arthroplasty is a very frequent surgical intervention. In some cases, vascular and nerve injuries may happen around the hip with total hip arthroplasty. Although they are very rare, they may be very dangerous for the patient in some cases. This paper presents a case of a female patient, in whom the nervous fibularis lesion was detected after the total hip arthroplasty, and the occlusion of the iliac femoral artery was revealed later during physical therapy., Case Report: We described a case of a 32-year-old female patient, in whom the nervous fibularis lesion was detected after the total hip arthroplasty. The patient was referred to a ward for physical therapy. On the 19th postoperative day, she felt a vigorous ache and numbness on the left operated leg during stimulation of the paretic fibular musculature. Clinically weak inguinal arterial pulse was detected. After the examination, iliac-femoral occlusion was diagnosed. The patient was referred to the vascular surgeon. In the next few months, she was treated conservatively and eventually underwent surgery. The revascularization was achieved with a satisfactory effect. A year after the total hip replacement, the patient continued with rehabilitation and physical treatment, which lasted one and a half month and had an incomplete functional result - the patient walked with a walking stick and had weak fibular musculature ofa severe degree. The vascular status of the leg was good., Conclusion: In this case, neurovascular lesions led to an incomplete functional recovery of the patient and compromised the expected treatment outcome. According to the scoring system used to assess the functionality, the result was marked as poor.

Bilateral leg compartment syndrome due to myonecrosis caused by inappropriate use of statins is a rare but potentially fatal complication of this lipid lowering medication. We report a case of a 39-year-old woman who presented with suspicious critical lower limb ischemia. Subsequently, bilateral leg compartment syndrome and myonecrosis developed. The primary cause of myonecrosis was due to misuse of simvastatin mistaken by the patient for a weight-reducing drug. Urgent fasciotomies were performed and the patient underwent urgent renal replacement therapy with continuous hemodialysis for acute renal failure due to myoglobinuria. After this complex treatment, the patient was discharged. She almost fully recovered with only a residual paresis of the left fibular nerve. According to literature, this is a unique case of bilateral compartment syndrome and myonecrosis with acute renal failure due to statin overdose leading to acute renal failure and bilateral fasciotomy.

Objective: To study the applied anatomy of the vascular and muscular innervations related to vascularized fibular grafts., Methods: Thirty-four cadaveric lower extremities were dissected for this study. The observations included fibular length, fibular nutrient artery, arcuate arteries, and innervation of fibular muscles. The fibulas were averagely divided into four segments and the locations of relevant vessels and nerves were ascertained., Results: All specimens had 1 fibular nutrient artery and 4-9 arcuate arteries except 1 specimen which had only 1 arcuate artery. The fibular nutrient artery and the first three arcuate arteries were constantly located between the distal half of the 1/4 segment and 2/4 segment of the fibula. The muscular branch of the superficial peroneal nerve passed through the surface of the periosteum in the 2/4 segment of the fibula., Conclusions: The most proximal osteotomy point locates at the midpoint of the 1/4 segment by which it ensure the maximal potential for preserving the nutrient vessels. The muscular branch of the superficial peroneal nerve is fragile to injury at the 2/4 segment of the fibula.

The tibial nerve has been reported to be often iatrogenically injured during fibular graft harvest, high tibial osteotomy and fascial release procedures. Despite this complication, there are limited data available in the literature concerning the surgical anatomy of tibial nerve branches in the deep posterior compartment of the leg. The aim of the present study was to quantitative and localize the motor nerve points for the flexor hallucis longus (FHL), tibialis posterior (TP) and flexor digitorum longus muscles (FDL) in relation to a regional bony landmark. The range for the number of branches of the tibial nerve and the terminal motor points of each muscle were identified and measurements were made with a digital caliper from these points to the apex of the head of fibula. Three particular types in the branching of tibial nerve were determined. In 55.6% of the cases there were separate branches to each of the muscles in the deep posterior compartment of the leg (Type I). In 30.6% of the cases there were two main branches of the tibial nerve that provided motor branches (Type II). Finally, the tibial nerve had one main branch, which gave rise to separate motor branches to each of the muscles in 13.8% (Type III). In 61.1% of the cases the FHL was innervated by proximal and distal branches of the tibial nerve. In 38.9% of the cases, it was innervated only by one proximal branch. In all of our cases, the TP was innervated by both proximal and distal branches and the FDL innervated only distally. This provided a detailed anatomical description of the tibial nerve in the deep posterior compartment of the leg. Knowledge of the variable peripheral course of the tibial nerve, as well as the detailed anatomy of its motor branches may decrease iatrogenic injuries and motor loss of the foot during surgical procedures.

Purpose: Since the first harvesting of a microsurgical fibula in 1974 by Ueba and in 1975 by Taylor, using the fibula for osseous reconstruction has proven to be a valuable approach. The harvesting technique, which has been refined by subsequent investigators, has become increasingly standardized, today providing a clear, reproducible method. The procedure involves elevating the fibular graft from lateral, choosing the shortest route to reach the fibula. One disadvantage of this approach is that the bone often obstructs visualization of the vascular pedicle, which lies medially, promoting unintentional injury. In addition, this method is associated with some donor site morbidity, prompting further investigations into accessing the fibula. Here we present an alternative approach for harvesting the fibula and highlight the pros and cons of each approach., Patients and Methods: Between 1999 and 2006, a total of 38 microsurgical (23 for the mandible, 9 for the extremities, and 6 for the maxilla) fibula grafts were harvested through the medial approach., Results: In all cases, the patency of the posterior tibial, peroneal vessels, and the tibial nerve could be visualized. Two flaps failed (both mandible, for a success rate of 94.7%). No ischemic or wound healing complications of the lower limb were observed., Conclusions: The medial approach for harvesting the fibula is a feasible alternative to the lateral approach and provides the surgeon with a comparable likelihood of success. If for some reason access from the lateral approach is contraindicated, then the medial route should be considered.

New patterns of intraneural ganglion cyst formation are emerging that have not previously been explained in current pathoanatomic terms. We believe there are three important elements underlying the appearance of these cysts: (a) an articular branch of the nerve that connects to a nearby synovial joint; (b) ejected synovial fluid following the path of least resistance along tissue planes; and (c) the additional effects of pressure and pressure fluxes. The dynamic nature of cyst formation has become clearly apparent to us in our clinical, operative and pathologic practice, but the precise mechanism underlying the process has not been critically studied. To test our hypothesis that a fibular (peroneal) or tibial intraneural cyst derived from the superior tibiofibular joint could ascend proximally into the sciatic nerve, expand within it and descend into terminal branches of this major nerve, we designed a series of simple, qualitative laboratory experiments in two cadavers (four specimens, six experiments). Injecting dye into the outer or "epifascicular" epineurium of the fibular and the tibial nerves we observed its ascent, cross over and descent patterns in three of three specimens as well as its cross over after an outer epineurial sciatic injection. In contrast, injecting dye into the inner or "interfascicular" epineurium led to its ascent within the tibial nerve and its division within the sciatic nerve in one specimen and lack of cross over in a sciatic nerve injection. Histologic cross-sections of the nerves at varying levels demonstrated a tract of disruption within the outer epineurium of the nerve injected and the nerve(s) into which the dye, after cross over, descended. Those specimens injected in the inner epineurium demonstrated dye within this tract but without disruption of or dye intrusion into the outer epineurium. In no case did the dye pass through the perineurial layers. Coupled with our observations in previous detailed studies, these anatomic findings provide proof of concept that sciatic cross over occurs due to the filling of its common epineurial sheath; furthermore, these findings, support the unifying articular theory, even in cases wherein patterns of intraneural ganglion cyst formation are unusual. Additional work is needed to be done to correlate these anatomic findings with magnetic resonance imaging and surgical pathology.

Mucoid cysts compressing the common peroneal nerve have been reported. Whether these cysts are schwannoma or are synovial in nature is the subject of controversy in the medical literature. To contribute to this debate, the present study was designed to detail the anterior innervation of the proximal tibiofibular joint. We dissected 10 knees of five fresh cadavers after staining the tibiofibular joint under fluoroscopic guidance. Through a lateral approach near the fibular head, the common peroneal nerve was isolated then dissected distally to determine whether it or its branches ramified over the proximal tibiofibular joint. In all 10 legs, only one collateral branch was observed on the common peroneal nerve proximal to its terminal division. This collateral sent a branch to the proximal tibiofibular joint before penetrating the tibialis anterior muscle. The articular branch coursed in a superior and posterior direction approximately 1 cm to attain the tibiofibular joint. In no specimen did the deep or superficial peroneal nerves send a twig to the tibiofibular joint. This study confirms and clarifies prior descriptions of the innervation of the anterior aspect of the proximal tibiofibular joint. It clarifies the mechanisms of compression of the common peroneal nerve by synovial cysts that originate from the proximal tibiofibular joint and provides anatomical landmarks that should facilitate complete resection of these cysts.

Purpose of the Study: Mucoid pseudocysts are infrequent benign tumors which can develop on all peripheral nerves near joints. The origin of these cysts remains to be determined. We searched for arguments favoring an articular origin which would have an impact on management and risk of recurrence., Materials and Methods: Twenty-three patients (21 men and 2 women, mean age 38 years, age range 13-56 years) presented mucoid pseudocysts and were followed for a mean six years. The mucoid pseudocyst was located on the common fibular nerve at the neck of the fibula in 16 patients, on the tibial nerve at the knee in one, on the median nerve in one, on the ulnar nerve in one, and on the suprascapular nerve in two. Pain was local in 18 patients and irradiated to the concerned nerve territory in 20. Motor deficit was the inaugural feature in 17 patients. EMG was performed in all patients, ultrasound exploration in 15, computed tomography in 7 and magnetic resonance imaging in 10. All patients included in this series underwent surgery: pathological diagnosis of mucoid intra-neural pseudocyst was established in all. Systematic search for communication with the neighboring joint was performed in all cases., Results: An articular communication was found in 17 patients. Mean time to recovery of muscle force (scored 5) and/or normal sensitivity was seven months in 17 patients. One patient did not achieve full recovery. Three patients experienced recurrence and required tibiofibular arthrodesis., Discussion: Three theories have been proposed (cystic degeneration of schwannoma, degeneration of nerve sheath connective tIssue, and an articular origin). The articular theory appears to be the most probable. The presence of an articular pedicle in 60% of the patients, the anatomic juxtaposition between the nerves involved and neighboring joints, and occasional migration along the articular nerve as well as the cyst's mucoid content argue in favor of the articular theory. The notion of recurrence after complete minute excision is also in favor of an articular pathogenic mechanism. The diagnosis of mucoid cyst should be retained as a possibility in patients with rapidly progressive signs of nerve compression near a joint. It is important to search for articular communication before and during the surgical excision in order to limit the risk of recurrence.

Traction injuries of the common fibular (peroneal) nerve frequently result in significant morbidity due to tibialis anterior muscle paralysis and the associated loss of ankle dorsiflexion. Because current treatment options are often unsuccessful or unsatisfactory, other treatment approaches need to be explored. In this investigation, the anatomical feasibility of an alternative option, consisting of nerve transfer of motor branches from the tibial nerve to the deep fibular nerve, was studied. In ten cadaveric limbs, the branching pattern, length, and diameter of motor branches of the tibial nerve in the proximal leg were characterized; nerve transfer of each of these motor branches was then simulated to the proximal deep fibular nerve. A consistent, reproducible pattern of tibial nerve innervation was seen with minor variability. Branches to the flexor hallucis longus and flexor digitorum longus muscles were determined to be adequate, based on their branch point, branch pattern, and length, for direct nerve transfer in all specimens. Other branches, including those to the tibialis posterior, popliteus, gastrocnemius, and soleus muscles were not consistently adequate for direct nerve transfer for injuries extending to the bifurcation of the common fibular nerve or distal to it. For neuromas of the common fibular nerve that do not extend as far distally, branches to the soleus and lateral head of the gastrocnemius may be adequate for direct transfer if the intramuscular portions of these nerves are dissected. This study confirms the anatomical feasibility of direct nerve transfer using nerves to toe-flexor muscles as a treatment option to restore ankle dorsiflexion in cases of common fibular nerve injury., (Copyright 2004 Wiley-Liss, Inc.)

There are many factors causing a compression of the fibular nerve accompanied by a loss of function. We describe an unknown cause: a chronic low-grade infection after implantation of a knee endoprosthesis. Perforation of the capsule of the knee joint followed by discharge of polyethylene particles originating from the endoprosthesis. A granuloma developed which resulted in a compression of the peroneal nerve with sensomotor disabilities. Preoperatively we were not able to define the dignity of the tumour. Neurolysis was performed followed by excision of the tumour. The infection was treated by long term antibiotics without removal of the endoprosthesis. Histological examination revealed the definitive diagnosis.

The peroneal nerve palsy at the fibular head is quite common but often difficult to diagnose both clinically and electrophysiologically. The purpose of this study was to evaluate the usefulness of the inching in mononeuropathy of the peroneal nerve at the fibular head. Recording from extensor digitorum brevis muscle the nerve was stimulated supramaximally at 1 cm intervals starting 2 cm distal and ending 8 cm proximal to the fibular head. Forty-six patients were examined: the inching was modified in 32 patients. In five of these the motor conduction using conventional method was normal, but the inching was normal or borderline in fourteen patients with reduced conduction velocity across the fibular head. Despite some limitations, the inching can be useful in evaluating patients with suspected palsy of the peroneal nerve at the fibular head.

The constant anatomic position of the common peroneal nerve is relied on when performing fine wire external fixation in the upper tibia. We report the case of a sixty-two-year-old woman with a Schatzker Type V fracture of her right tibial plateau and upper-third diaphyseal fracture associated with displacement and shortening of the upper tibia. She was treated by minimal internal fixation of the intraarticular fracture and application of a Sheffield Hybrid External Fixator. During percutaneous insertion of the reference wire in the fibular head, a distal muscle twitch alerted the surgeon, and the common peroneal nerve was duly explored and found displaced forward over the fibular head, dangerously close to the wire. It is postulated that at the time of injury, the common peroneal nerve was displaced anteriorly and that despite reduction of the tibial fractures, it had failed to return to its original position. The mechanism of this was confirmed by an anatomic study on an above-the-knee amputation specimen in which the metaphyseal-diaphyseal element of the fracture was reproduced. We recommend insertion of the reference fibular wire with the knee in flexion. Open insertion of this wire, with an incision down to bone and exposure of the fibular head, is recommended in cases in which severe trauma with shortening of the upper tibia, with possible disruption of the tibiofibular joint, puts the nerve in danger of injury.

Objective: To describe the anatomical relationship of the sural sensory nerve complex to the posterior crural intermuscular septum (PS), the key anatomical structure for the osteoseptocutaneous fibula skin paddle., Design: Anatomical study., Subjects: Twenty-two legs from 11 cadavers (7 females and 4 males)., Results: The lateral sural cutaneous (LSC) nerve, present in 20 of 22 legs, divides into lateral and medial branches near the head of the fibula. The LSC nerve and its medial branch course away from the PS, whereas the lateral branch tends to course toward the PS. The lateral branch courses nearest to the PS at a median distance of between 4 cm proximally and 3 cm distally. The medial branch of the LSC nerve terminates approximately in the middle of the leg, and the lateral branch of the LSC nerve terminates within 7 cm below the head of the fibula. The peroneal communicating branch is thicker than the LSC nerves; however, it is further from the PS in the upper leg., Conclusions: The LSC nerve is the most consistent and accessible donor sensory nerve in the posterior leg for harvest with the osteoseptocutaneous fibula free flap. Results of this study will assist the surgeon in harvesting a sensory nerve with the osteoseptocutaneous fibula free flap, bringing this potentially sensate flap into more common use. Arch Facial Plast Surg. 2000;2:252-255

F wave latency has been shown to be a simple and valuable method in evaluation of proximal part of peripheral nerves. According to our previous study of F wave of upper extremity nerves (1), maximum normal F wave latency for the median nerve was 28 ms with stimulation at wrist and 25 ms with stimulation at elbow. These values for the ulnar nerve were 29 ms and 25 ms respectively. Maximum normal difference between right and left F wave latency with wrist stimulation was 2 ms for median nerve and 2.5 ms for ulnar nerve. Maximum normal difference between median and ulnar nerve F latency was 3.5 ms with stimulation at wrist. In this study we measured F wave of lower extremity nerves in 73 healthy individuals in Shiraz. Maximum normal F wave latency for tibial nerve was 55 ms with stimulation at ankle and 46 ms with stimulation at popliteal area. Maximum normal F wave latency for the peroneal nerve was 54 ms with stimulation at ankle and 47 ms with stimulation at fibular head. Mean F ratio for both nerves was 1.29 with stimulation at knee. Maximum normal difference in F wave latency between right and left lower extremities was 3.5 ms with stimulation at ankle and 3 ms with stimulation at knee for the peroneal nerve. These values were 3 ms and 2.5 ms for the tibial nerve respectively. Maximum normal difference in F wave latency between tibial and peroneal nerve was 4 ms with stimulation at ankle and 3 ms with stimulation at knee.

Peroneal motor studies to the extensor digitorum brevis are commonly performed in electrodiagnosis. They have been investigated by many authors to derive the normal ranges for latency, amplitude, and nerve conduction velocity. Many of these studies, particularly the older ones, have methodological limitations, especially in light of modern technique and statistical applications. They often used small sample sizes. The objective of this study was to generate an expanded database of normative values for the peroneal nerve. In this study, 242 asymptomatic subjects without risk factors for neuropathy were tested, and their peroneal motor response was analyzed for latency, amplitude, area, duration, and nerve conduction velocity. Side-to-side and proximal-to-distal variation was recorded. Mean +/- 2 standard deviations (SD) and percentiles of normality are presented. Mean onset latency was 4.8 ms (SD, 0.8). Mean amplitude was 6.8 mV (SD, 2.5) and 5.1 mV (SD, 2.5) for the younger and older than 40-yr age groups, respectively. Mean nerve conduction velocity ranged from 44 to 49 m/s, depending on the demographic group (SD, 4-5). The upper limit of normal side-to-side latency variation was 1.4 ms (mean + 2 SD). The upper limit of normal drop in nerve conduction velocity from the low leg to the across knee segment was 10 m/s (mean - 2 SD) or 12% (97th percentile). The upper limit of normal amplitude difference from side to side was 61 % (at the 97th percentile), and the upper limit of normal drop in amplitude from below to above the fibular head stimulation was 25% (at the 97th percentile). The other measures are presented in the article.

The interosseous nerve of birds innervates a string of Herbst corpuscles located near the interosseous membrane between the tibia and fibula. Fibre composition of this nerve was assessed including both myelinated and unmyelinated axons. The diameter of the whole nerve is approximately 100 microm. Complete data were obtained for 3 nerves. The mean total number of myelinated fibres and unmyelinated axons was 2872 +/- 53. The mean number of myelinated fibres was 280 +/- 20 and that for unmyelinated axons was 2600 +/- 47. There was a broad distribution of diameters for myelinated fibres ranging from approximately 2 microm to 10 microm with a distinct peak at approximately 3-5 microm and a less prominent second peak at 6-8 microm. Similarly, myelin sheath thickness distribution showed 2 peaks, one at 0.6-0.8 microm and another at 1.4-1.6 microm. It is suggested that the group represented by the second peak innervates the Herbst corpuscles. The group of smaller myelinated fibres and the unmyelinated axons are assumed to innervate other types of receptors, some of which may be nociceptors.

We report the occurrence of bilateral foot-drop in a patient with anorexia nervosa. To the best of our knowledge this has not been reported previously. The underlying pathology was found to be peroneal nerve palsy probably related to mechanical pressure at the head of the fibula. Nutritional deficiency may also be implicated.

Five patients with giant cell tumor of the proximal fibula were treated with intralesional excision of the lesion, preservation of the peroneal nerve, and reconstruction of the lateral collateral ligament. At minimum 24-month follow-up there have been no local recurrences. Four patients exhibit normal function of the peroneal nerve and one has grade 4 strength of the muscles innervated by this nerve. No patient demonstrated varus instability. Marginal excision with nerve preservation and reconstruction of the ligament is a worthwhile procedure for treatment of this relatively uncommon lesion.

We dissected fifty legs from twenty-six cadavera to determine the origin and frequency of nerves that crossed the line of a lateral approach to the distal part of the fibula. A branch of the sural or common peroneal nerve, or both, that was at least one millimeter in diameter crossed the line of the operative approach in eleven legs (22 per cent) and was within five millimeters of the anterolateral border of the fibula in twenty-seven legs (54 per cent). We recommend that a meticulous operative technique be used during exposure of the distal part of the fibula to prevent paresthesias or painful neuromas resulting from the inadvertent transection of these small nerves.

Twenty legs in 10 cadavers were dissected to determine the course of the deep peroneal nerve from its origin to its termination. Particular attention was paid to defining: (1) its relationship to palpable landmarks, (2) the angle of the course of its proximal portion against the long axis of the fibula, (3) distribution of the proximal branch to the extensor hallucis longus muscle, and (4) safe areas of osteotomy in the proximal fibula during high tibial osteotomy. The extensor hallucis longus was often supplied by only one branch from the deep peroneal nerve at 99.8 mm (31.7%) distally from the apex of the fibula; this seems to explain why osteotomy of the fibula at its proximal one third often causes paralysis of this muscle. The findings suggest that safe areas for osteotomy in the proximal fibula during high tibial osteotomy are located up to 20.5 mm (6.5%) distal to the tip of the fibular head and that the safe angle of a periosteal incision against the fibular neck area is 64.1 degrees.

The free osteofasciocutaneous fibular transplant is a direct development of the free fibular bone graft used from 1983 in reconstructive surgery of the long bones. In 1989, Hidalgo was the first to publish a method of reconstruction of the mandible by composite free fibular transplants. The aim of this study was to specify the anatomy of the osteofascio-cutaneous fibular graft and particularly of the vessels to the skin. The sensory innervation of this transplant is described.

Iatrogenic, isolated weakness or paralysis of the extensor hallucis longus muscle is a common complication in patients who have had a proximal tibial and fibular osteotomy. To investigate why this complication occurs, we dissected the deep peroneal nerve and neighboring structures, such as the tibia and fibula and the muscles of the leg, in twenty-nine specimens from cadavera, paying special attention to the motor branches supplying the extensor hallucis longus. Of forty-six motor nerves that were identified, eight entered the muscle from the lateral side in an area seventy to 150 millimeters distal to the fibular head; all of them ran close to the fibular periosteum. We suggest that, in some patients, the nerve supply to the extensor hallucis longus is at high risk for injury during a tibial osteotomy because of the proximity of the bone to the motor branches.

Twenty preserved cadaver limbs were dissected to show the distal course of the sural nerve and the number and site of origin of its branches. The mean position of the main nerve trunk was calculated at various points related to bony landmarks of the fibula and the fifth metatarsal base. Ninety-five percent confidence limits for the course of the main nerve trunk could be described. A fibula incision may damage the nerve if it extends more than 7 mm inferior to the lateral malleolar tip with the foot in equinus. Dorsolateral foot incisions may damage both the main trunk and the major anterior branch.

The author has studied, in a group of 40 dissections on cadavers of individuals of different ages, the main "critical zones" of entrapment of some terminal branches of the lumbo-sacral plexus, which include canals (fibrous, osteo-fibrous, fibro-muscular), intervals (intermuscular, fibro-muscular, musculo-ligamentous), rings (fibrous or fibro-muscular) and foramina. They provide the topographical anatomical basis for possible compressive phenomena of the nerves of the lower limb.

1. The fibular nerve was transplanted on to the soleus muscle of the rats. Interruption of the original soleus nerve then permitted cross-innervation, and subsequently, over a period of weeks, re-innervation by the original nerve. 2. Individual muscle fibres were often innervated by both the original and the foreign nerve. The original and foreign end-plates were located in separate regions of the muscle. There were no indications that the original nerve could displace or repress the foreign innervation. 3. The extent of re-innervation by the original nerve depended upon the method of denervation. A single crush of the nerve was followed by virtually complete re-innervation, even of muscle fibres already innervated by the foreign nerve. When re-innervation was delayed by resection of a segment of the nerve only muscle fibres without foreign nerve innervation were re-innervated. Denervation by a simple nerve cut gave an intermediate result. 4. Re-innervation by the original nerve can take place without measurable extrajunctional sensitivity to ACh. 5. The original end-plate region could retain high and localized sensitivity to ACh for several months despite degeneration of its motor nerve terminal and activity of the muscle fibre. 6. Established foreign end-plates were re-innervated by the foreign nerve on muscle fibres with intact original innervation. 7. The factors controlling synapse formation in skeletal muscles are discussed.

Periosteal proprioceptive nerve receptors may act as mechanoreceptors of long bones during adaptive remodeling after fracture. They may also contribute to the mechanisms of coordinated functional activity of fractured limbs and thus inhibit harmful overloading of fracture callus. The area of proprioceptive nerve receptors around the distal part of the rat fibula was stripped surgically, and a standard fracture of the fibular shaft was produced. Animals failed to unite their fractures and developed mainly atrophic nonunions. Atrophy of ununited fragments was due to osteoclastic bone resorption. Atrophy of the bone fragments was aggravated if the legs were also subjected to sciatic denervation. Sciatic denervation alone, without removal of receptors, did not interfere with the union of fractures. The results indicate that the area of proprioceptive receptors in the rat tibiofibular bone is critical for the healing of fibular fractures. Because the effect on bone healing of receptor removal was not inhibited by sciatic denervation, the effect was not transmitted through spinal pathways of the sciatic nerve. The development of nonunions could not be explained by the surgical trauma alone. Aggravation of fibular atrophy by sectioning of the sciatic nerve suggests that some neural elements are associated with the phenomenon, either directly or indirectly through neuromuscular function.

The operative treatment of six cases of paresis of the fibular nerve caused by external compression in five patients are reported. From the intraoperative findings and the postoperative results, decompression of the fibular nerve with simultaneous neurolysis can be recommended as the optimal method for cases, which have been treated conservatively without success.

The authors report on a newborn with skin necroses and fibularis paresis after postnatal administration of NaHCO3 via the umbilical cord. Then some problems of postnatal buffer therapy are discussed. After a review of advantages and disadvantages of puncture or cannulation of the umbilical vein on the one hand and its catheterization on the other, the former procedures are preferred for an effective buffer therapy, provided strict indications are followed.

A study was conducted to determine the acceptable fibular motor nerve conduction velocity (NCV) in goats and to characterize pressure-induced changes in conduction velocity and muscle-evoked potentials (MEP). The acceptable motor NCV in the adult goat was determined to be 95.9 +/- 6.8 m/s. Limb compression in recumbent cows was modeled by application of external compression to the goat pelvic limb to increase IM pressure to a minimum of 50 mm of Hg. This pressure, when applied for a 6-hour period, caused a 30% to 100% reduction of fibular motor NCV and a 10% to 100% reduction of amplitude of MEP measured from fibularis (peroneus) tertius muscle. The reduction of motor NCV and MEP was associated with clinically evident limb dysfunction. The changes detected by the electrodiagnostic tests were proportional to the magnitude and duration of the locomotor deficits. The limb dysfunction was accompanied by muscular damage indicated by an increase of serum creatine kinase activity.

Transection of the common fibular (FIB) nerve caused an immediate reduction in the total amount of soleus (SOL) motor unit activity, which declined further during the following 10 days and then remained stable at less than half of normal values. In addition, there was an immediate reduction in median impulse rate from about 20.0 to 14.9 Hz followed by a return to normal values during the first 10 days. Short interval (3-4 ms) double discharges, occurring either in isolation or at the same regular intervals as single impulses, were observed 2-5 days after FIB nerve section in a few motor units. Brief, high frequency impulse bursts with interspike intervals of 12-16 ms were observed in a few units from the third day and until the end of the experiment (up to 31 days). It was not established whether the high frequency discharge pattern occurred only in a fixed population of the SOL motor units, or whether the units could switch between high and low frequency activity. Two months after FIB nerve section, the SOL muscle in the same leg contracted faster than normal (mean isometric twitch contraction time 29.6 ms, n = 4; vs. 38.7 ms, n = 8), contained a larger than normal percentage of type II fibres (13-36 vs. 0-0.2%) and weighed less than the contralateral SOL muscles (180 vs. 206 mg). SOL muscles (n = 4) in the opposite leg were comparable to normal SOL muscles except for a small reduction in mean isometric twitch contraction time (35.5 ms).

Soleus (SOL) and extensor digitorum longus (EDL) muscles in adult rats were kept denervated for 2 months by four repeated freezes at 2-week intervals of the sciatic nerve. Reinnervation was studied in the absence or presence of chronic muscle stimulation, starting 1 month before reinnervation began. In addition, reinnervation was studied in SOL muscles where a previously transplanted fibular (FIB) nerve had formed ectopic neuromuscular junctions outside the original endplate area. After repeated freezes only, reinnervation was complete judged by tension measurements and histochemical examinations in SOL (n = 7) and EDL (n = 8) muscles. In directly stimulated muscles reinnervation was incomplete, and the force tensions evoked from indirect stimulation was on average 87 (n = 5) and 82% (n = 5) of direct muscle stimulation in SOL and EDL muscles, respectively. Of ectopically innervated SOL muscle fibres, only 26% became reinnervated in 12 muscles. Denervation and reinnervation increased the number of muscle fibres in stimulated (n = 4) and unstimulated (n = 5) EDL muscles by 18 and 15%, respectively. In stimulated (n = 4) and unstimulated (n = 7) SOL muscles, on the other hand, the number of muscle fibres remained normal. The stronger suppression of reinnervation in ectopically reinnervated compared to chronically stimulated SOL fibres indicates that reinnervation can also be suppressed by activity independent influences from the foreign nerve.

Extra- and intraneural ganglionic cysts rarely involved peripheral nerves. They are found in the neighbourhood of large joints. Intraneural cysts prefer the deep peroneal nerve and cause intermittent pain and severe nerve damage. The ulnar nerve is affected most often at the wrist. There are different types of distal motor and/or sensory ulnar palsy. Spontaneous recovery may take place and recurrences of intraneural cysts of the peroneal nerve occur after surgery.

1. Responses of receptors with fibres in the interosseous nerve of the duck's leg have been studied by recording unit discharges in filaments dissected from the sciatic nerve.2. Seventy-two of the ninety-four units examined served highly phasic, vibration-sensitive mechanoreceptors in the interosseous region interpreted as being Herbst corpuscles. Receptor types for most of the other units could not be determined, but some were slowly adapting mechanoreceptors.3. Rheobase threshold values for the most sensitive vibration-receptors were similar to those of mammalian Pacinian corpuscles.4. Threshold-frequency relationships for the vibration receptors showed a wider range of low frequency cut-off values, and a greater capacity to signal high frequencies, than is the case with Pacinian corpuscles.5. Fibres of the vibration-receptors had calculated diameters ranging from 5 to 10 mum and account for the bulk of the larger fibres in the interosseous nerve.6. It is suggested that Herbst corpuscles in the legs of birds might act as a warning device by detecting vibratory disturbances of the ground or other supporting surface.