Clinical importance of the lateral branch of the deep peroneal nerve.

Persistent recalcitrant dorsolateral foot pain after ankle sprain cannot always be explained by known anatomic nerve pathways. To determine whether an impingement of a lateral branch of the deep peroneal nerve might be responsible for atypical pain, we conducted a cadaveric anatomic study to identify the anatomy and course of the nerve. Furthermore, using this information, we conducted a clinical study to determine if targeted treatment to a lateral branch of the deep peroneal nerve would resolve these symptoms. We dissected 22 cadaveric feet to identify a large lateral branch of the deep peroneal nerve. This nerve arborized into five main branches. We identified two areas of compression in the lateral branch of the deep peroneal nerve. We also performed a prospective clinical study including 11 consecutive patients with a 1-year minimum followup. Pain and clinical findings corresponded to the anatomic compression sites in all 11 patients. All patients responded to a local anesthetic injection or surgical release of the lateral branch of the deep peroneal nerve. We identified a previously unreported complex course of the lateral branch of the deep peroneal nerve that correlated with clinical impingement syndrome and responded to specifically targeted treatment.

Tarsal coalition.

Tarsal coalition is a common abnormality of the hindfoot skeleton that only rarely leads to symptoms. These symptoms occur most commonly in adolescence but rarely can be found also in adults. Although most coalitions are congenital, as the consequence of autosomal dominant inheritance, coalitions also can be acquired by degenerative joint disease, inflammatory arthritis, infection, and clubfoot deformities. Fifty percent of all coalitions are bilateral. Talocalcaneal and calcaneonavicular coalitions are most commonly found, and patients frequently have more than one coalition in the same foot. Clinical symptoms of the tarsal coalition frequently follow a sequence of sprains or other minor injuries to the involved foot. This leads to a rigid, painful foot. The pain is worsened by continued activities. The frequently cited peroneal spastic flatfoot is an uncommon means of identifying a tarsal coalition. The diagnosis of the tarsal coalition is made on the oblique radiograph of the foot, which demonstrates the calcaneonavicular coalition. Computed tomography (CT) and magnetic resonance imaging scans show the presence and extent of other coalitions. Secondary signs for the presence of a coalition are talar beaking, anteater nose sign, and C sign. These secondary signs can be demonstrated best on a lateral view of the involved foot. Local anesthetic blocks under image intensifier or CT guidance can identify areas of joint degeneration, which are caused by the altered biomechanics of the foot. Initial treatment should consist of conservative therapy in the form of support or immobilization of the involved foot, change in the activities of the patient, and nonsteroidal anti-inflammatory medication. Surgical treatment in the form of a resection of the coalition should be reserved for those patients for whom conservative therapy has failed. Subtalar or triple arthrodesis should be reserved for those patients for whom all other therapy has failed.

Ganglion cysts of the lower extremity: an analysis of 54 cases and review of the literature.

This article reviews 54 consecutive patients with lower extremity ganglion cysts that were surgically removed and histologically confirmed at the Hospital for Special Surgery from 1981 to 1993. Lower extremity ganglia were more common among women. Patients' ages ranged from 13 to 80 years, with the fifth and sixth decades being the most common. Size of the cysts ranged from 3 cm to 10 cm (average: 2.9 cm). Thirty-six (67%) patients had ganglion cysts of the foot and ankle, and 18 (33%) patients had ganglion cysts of the knee area. Four (7%) patients had intraosseous ganglia located in the proximal tibia, patella, and the first metatarsal head. Follow-up data of 40 (74%) patients at an average of 5.9 years (range: 1 to 12.5 years) were obtained. Satisfaction was reported by 83% of patients. Recurrence was seen in 10% of patients, and a report of no or mild pain was given by 86% of the group. Patients who underwent revision ganglion excision had inferior results. Only 25% reported satisfaction and 50% reported no or mild pain. Patients who underwent curettage of an intraosseous ganglion appeared to have superior results. All patients reported satisfaction and no or mild pain. The performance of a concomitant surgical procedure, the anatomic region of the ganglion, or type of postoperative immobilization did not appear to affect the outcome.

Action of the peroneus longus tendon on the first metatarsal against metatarsus primus varus force.

A medially directed force was applied to the first metatarsal in 10 cadaver feet. The peroneus longus tendon was subjected to a pull of 5 pounds. The soft tissues between the first and second metatarsals were cut sequentially, starting with the skin on the dorsal and plantar aspect, followed by the intermetatarsal ligament and adductor hallucis tendon, and, finally, the peroneus longus tendon at its distal insertion. Dorsoplantar radiographs while weightbearing were taken after each sectioning. A statistically significant varus displacement of the first metatarsal was observed only after transection of the peroneus longus tendon. It was concluded that the peroneus longus tendon is a strong retaining mechanism of the first metatarsal.

Anatomy of the Achilles tendon and plantar fascia in relation to the calcaneus in various age groups.

Ten adult cadaver feet, three neonatal feet, and the feet of two fetuses were dissected to investigate whether an anatomical continuity exists between the fibers of the Achilles tendon and the plantar fascia. Histologic sections of the feet were done in three age groups: neonate, persons in their mid-20s, and the elderly. As the foot ages, there appears to be continued diminution of the number of fibers connecting the Achilles tendon and plantar fascia. The neonate has a thick continuation of fibers, while the middle-aged foot has only superficial periosteal fibers that continue from tendon to fascia. The elderly feet show simply an insertion of fibers of both structures into the calcaneus with periosteum in between.

Spindle cell lipoma of the foot: a case report and literature review.

Lipomas are among the most commonly encountered soft tissue tumors in clinical practice, though they are rare in the foot. Although a presumptive diagnosis is typically made clinically, those tumors with atypical clinical features may require radiological consultation. Difficulty arises when radiographic features are not typical of lipoma. We present a fatty soft tissue tumor of the foot with nonadipose elements on magnetic resonance imaging evaluation. Differentiation of lipoma variants (e.g., spindle cell lipoma, atypical lipoma, pleomorphic lipoma, lipoblastoma, angiolipoma) from liposarcoma based on imaging features is not possible, necessitating surgical resection for definitive histological diagnosis.

The superior peroneal retinaculum: an anatomic study.

The superior peroneal retinaculum is thought to be the primary restraint to subluxation and/or dislocation of the peroneal tendons as they pass posterior to the distal fibula. The descriptions in anatomy texts vary widely. This anatomical study describes the different patterns of insertions for the superior peroneal retinaculum and its relationship to the peroneal tendons and the ligaments of the lateral ankle.

Lateral ankle instability as a cause of superior peroneal retinacular laxity: an anatomic and biomechanical study of cadaveric feet.

The role of the competent superior peroneal retinaculum (SPR) as a primary restraint to peroneal tendon subluxation and mechanical attritional wear is clear. Injury to the SPR has classically been described as a dorsiflexion eversion movement of the ankle coupled with a forceful peroneal tendon reflex contraction. This mechanism, however, does not cause injury to the lateral collateral ligaments of the ankle and does not explain the coexistent findings of lateral ankle instability, laxity of the SPR, and concurrent peroneal tendon pathology. Anatomic studies reveal a parallel alignment of the calcaneal band of the SPR and the calcaneofibular ligament. A cadaveric model of ankle instability created by serial sectioning of the lateral collateral ligaments revealed increasing visual strain on the SPR with increasing degrees of ankle instability. These findings suggest the SPR serves as a secondary restraint to ankle inversion stress and that the force or forces that result in chronic ankle instability can also injure and attenuate the superior peroneal retinaculum.

Peroneal tendon subluxation in a case of anomalous peroneus brevis muscle.

We report a case of peroneal tendon subluxation as a result of an anomalous extension of the peroneus brevis muscle into the fibular groove, causing an encroachment phenomenon, stretching-out of the superior peroneal retinaculum, longitudinal splitting of the peroneus brevis tendon, subluxation of the peroneal tendons, and peroneal tenosynovitis. We describe a simple surgical technique for tendon stabilization, after decompression of the fibular groove.

Microvascular anatomy of the peroneal tendons.

The etiology of longitudinal splitting of the peroneus brevis tendon is unclear. It has been hypothesized that compressive load applied to the tendon as it passes through the fibular groove may compromise the vascularity of the tendon with resultant inhibition of the repair response and degeneration of tendon structure. To investigate this possibility, a study of the microvascularity of the peroneal tendons was undertaken. Twelve fresh, frozen cadaveric limbs were injected with India ink. The vascularity of the peroneal tendons was examined in situ and the tendons were harvested and cleared using a modified Spalteholz technique. The vascularity of the cleared tendons was evaluated utilizing a dissecting microscope. The vascular supply of the peroneal tendons arises from two posterolateral vincula, one for the peroneus longus tendon and one for the peroneus brevis tendon. These vincula are supplied by branches of the posterior peroneal artery. A zone of hypovascularity within the peroneus brevis or peroneus longus tendon correlating with the site of peroneus brevis splits was not found. There was no relationship between increasing age of specimens and alteration in vascular supply.

The dynamics of peroneus brevis tendon splits: a proposed mechanism, technique of diagnosis, and classification of injury.

The etiology of peroneus brevis splits is unclear. Because longitudinal splits in the peroneus brevis tendon do not necessarily effect the integrity or strength of the tendon, it is difficult to ascertain whether or not injury to the peroneus brevis tendon is present. Recent clinical, anatomic, and histologic reports have suggested that the split develops from prolonged mechanical attrition within the fibular groove as a result of ankle trauma with resultant lateral ankle instability and incompetency of the superior peroneal retinaculum with resultant subluxation of the peroneal tendons. This cascade of events may result in splitting of the peroneus brevis tendon. The purpose of this paper was to report the investigation of the mechanism by which peroneus brevis splits develop, to describe a technique of diagnosis, and to propose a classification of injury. Peroneus brevis splits are the result of a dynamic mechanical insult at the fibular groove. Laxity of the superior peroneal retinaculum combined with peroneus longus mechanical compression causes the peroneus brevis to splay out and eventually split over the sharp posterior edge of the fibula. Anatomic factors, such as a shallow fibular groove (congenital convex groove) or the presence of an anomalous low-lying peroneus brevis muscle belly or peroneus quartus tendon, may also play a role in this mechanism by interfering with the competence of the superior peroneal retinaculum.

The microvasculature of the sesamoid complex: its clinical significance.

The microvascular anatomy of the sesamoid complex was investigated in 15 cadaver specimens using histology and tissue clearing (Spalteholz) techniques. It was found that both sesamoids appeared equally well vascularized and the vascular supply to each sesamoid originated from two major sources (proximal and plantar) and one minor source (distal). Proximally, vessels originating from the first plantar metatarsal artery enter the sesamoid at its attachment to the flexor hallucis brevis. In addition, vessels enter the plantar surface of the sesamoid near the midline and arborize throughout the bone, anastamosing with the proximal vessels. The distal vascular supply to the sesamoids originates from its distal capsular attachment and appears to contribute minimally to the overall vascular scheme. The lateral attachments of the sesamoids to the plantar plate and joint capsule were relatively avascular. In two bipartite specimens examined, the major blood supply originated from the proximal and distal poles of the sesamoid. No vessels were observed entering the plantar surface of these specimens. The results of this study suggest that injury to the proximal or plantar aspects of the sesamoids could disrupt the vascular supply to these bones. These areas should, therefore, be avoided during the surgical approach to the sesamoids.

Longitudinal splitting of the peroneus brevis tendon: an anatomic and histologic study of cadaveric material.

Gross and microscopic examinations of 21 split and 10 intact cadaveric peroneus brevis tendons were performed in an effort to determine the pathogenesis of longitudinal splitting of this tendon. The split regions were centered over the posterior margin of the distal fibula and were characterized by splaying of the collagen bundles with accompanying proliferation of blood vessels and fibrovascular connective tissue. Inflammatory infiltrates were not present. Regions of the tendons that were not altered had normal cellularity and orientation of the collagen. The findings of this study suggest that the splitting of the tendon develops through a mechanical mechanism.

Cadaver correlation of peroneal tendon changes with magnetic resonance imaging.

Magnetic resonance imaging (MRI) is used to show the soft tissues of the body. The presence of anomalous tendons and muscles can be detected. Chronic lateral ankle pain and instability can be associated with peroneal tendon pathology and MRI may be used to assess both longitudinal attrition of the peroneus brevis tendon, as well as the presence of the peroneus quartus which may be useful in lateral ankle reconstruction. Tenography can occasionally present technical difficulties and can lead to patient dissatisfaction.

Longitudinal attrition of the peroneus brevis tendon in the fibular groove: an anatomic study.

There has been little research concerning the attrition of the peroneus brevis tendon since Meyer's observation in 1924. The purpose of our dissections was to establish the incidence of the attrition of the peroneus brevis tendon at the fibular groove, and observe the anatomical relationship of the tendon attrition to the bony anatomy of the distal fibula. One hundred and twenty-four fresh human cadavers ankles from 65 cadavers were dissected under loupe magnification. When attrition of the peroneus brevis was found, the extent of attrition was measured, and anatomic proximity of the tendon to distal fibular groove was observed. Evidence of other tendon attrition as well as the depth of the fibular groove was observed. Specimens which revealed attrition of the peroneus brevis were sketched and photographed. Attrition of the peroneus brevis tendon was found in 14 ankles (11.3% of specimens). The attrition was limited only to the peroneus brevis tendon, and in no specimens was the peroneus longus involved. The degree of tendon attrition varied from simple splaying out of the peroneus brevis in the fibular groove to longitudinal splits in the peroneus brevis tendon with significant fraying of the remaining halves of the tendon. The longitudinal ruptures in the peroneus brevis tendon averaged 1.9 cm (range 1-4 cm). In all cases, the central portion of the longitudinal split was centered over the distal tip of the fibula in the fibular groove. In no case was a complete rupture of the peroneus brevis tendon noted. There was gross evidence of chronic inflammation and synovitis in those ankles with attrition of the peroneus brevis tendon.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital variations of the peroneus quartus muscle: an anatomic study.

There has been little research concerning this muscle since the 1920s, when Hecker described this muscle to be present in (13%) of his dissections of cadaver legs. The purpose of our dissections was to establish the incidence of the peroneus quartus muscle, its origins, and insertions. One hundred and twenty-four legs from 65 fresh human cadavers were dissected under loupe magnification. When the peroneus quartus tendon was found, its origin, insertion, and anatomic relationship to the peroneus longus and peroneus brevis were observed. All specimens were sketched and photographed. The peroneus quartus muscle was present in 27 legs (21.7% of specimens). Its origins, insertions, and size varied. In 17 legs (63%) the muscle originated from the muscular portion of the peroneus brevis, and inserted on the peroneal tubercle of the calcaneus. The peroneal tubercle was hypertrophied at the insertion in most cases. The results of this study in general show that there was much higher incidence of the peroneus quartus muscle than Hecker claimed. Its course, origin, and insertion varied. Its tendon can be used for reconstructive procedures about the lateral aspect of the ankle, especially in anterior dislocation of the peroneal tendons and reconstruction of lateral ligaments.

Gait analysis in surgically treated clubfoot.

Clubfoot, a congenital foot abnormality, has been successfully managed with surgical treatment. To assess gait in individuals with surgically treated clubfeet, the patterns of electromyographic activity for the medical gastrocnemius and tibialis anterior muscles and the stride characteristics during gait were measured and compared with normal values. The duration of medial gastrocnemius activity was significantly greater than normal, whereas tibialis anterior activity, stride length, and single limb support times were not different. No correlation was found between the results of the gait analysis and the quality of the surgical result.

Bone scanning for the evaluation of knee prosthesis.

Twenty-six knees were scanned after total replacement to evaluate the relationship between bone scan, pain, the presence of a radiolucent line at the bone-cement interface and loosening. A radiolucent line was often accompanied by an increased uptake over the affected condyle, but there was no significant relationship with pain or loosening.

Spontaneous osteonecrosis of the knee.

Spontaneous osteonecrosis was diagnosed in ninety knees in which a roentgenographically visible lesion had developed within six months after onset of symptoms. Scintimetry can be used to differentiate between osteonecrosis and other painful conditions of the knee. The prognosis of osteonecrosis is dependent on the size of the radiolucent lesion. In knees with a lesion that is larger than 2.3 square centimeters, osteoarthritis is likely to develop. For forty-two knees the patients were treated with analgesics, partial weight-bearing, and quadriceps exercises. Forty-eight knees were treated surgically. Indications for surgical treatment were persistent severe complaints in spite of conservative treatment and a large osteonecrotic lesion with collapse of the condyle resulting in a varus deformity. The best results were achieved with osteotomy together with arthrotomy, and by knee replacement arthroplasty. Arthrotomy and drilling alone were ineffective.