A radiolucent lesion in the medial femoral condyle was observed in 40 knees in 39 patients over age 60. Mast patients had had spontaneous onset of severe knee pain. Twelve knees were radiographically normal within 2 months following onset of pain. Seven knees proceeded to osteoarthritis whereas others became rather asymptomatic. Strontium-85 scintimetry of symptomatic knees showed N THE COURSE of prospective studies I of osteoarthritis of the knee we became aware of a peculiar radiolucent lesion of subchondral bone in the medial femoral condyle. Radiographically, this lesion differed from osteochondritis dissecans in appearance and location. It afEicted aged rather than adolescent individuals and was associated with spontaneous pain in the knee. This particular lesion has received only minimal attention; previous descrip-

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.

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.

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.

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.

The current study identified a deficiency in the AOFAS score in evaluating functional ankle stability after the Broström-Gould procedure. A more meaningful analysis of outcomes can be expected using the SF-36 score. The data suggest that greater attention must be paid to functional rehabilitation after ankle stabilization surgery to obtain optimal outcome.

Several methods of obtaining ankle fusion have been described, with numerous studies reporting on patient populations with varied diagnoses and various methods of fixation. This has led to outcome analyses that are difficult to interpret. Our hypothesis is that using a standard method of fusion, without the aid of allograft, a solid ankle fusion can be achieved in patients with end-stage ankle arthritis, and that this outcome can be reflected in standardized outcome tools. Forty-one consecutive ankle fusions in 40 patients were included in our study, with a minimum followup of 3 years. All patients had an ankle arthrodesis using two parallel retrograde 7.3-mm screws and local fibular graft. All but two patients obtained a solid talocrural union (95%), with a mean postoperative improvement in the American Orthopaedic Foot and Ankle Society score of 23 points. Results of our study showed that a simple technique based on sound mechanical and biologic principles can yield excellent outcomes for patients.

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)