Foot & Ankle International

The Austin osteotomy is a widely accepted method for correction of mild and moderate hallux valgus. In view of publications by Kitaoka et al. in 1991 and by Mann and colleagues, a more radical lateral soft tissue procedure was added to the originally described procedure. From September 1992 to January 1994, 85 patients underwent an Austin osteotomy combined with a lateral soft tissue procedure to correct their hallux valgus deformities. Seventy-nine patients (94 feet) were available for follow-up.

The average patient age at the time of the operation was 47.1 years, and the average follow-up was 16.2 months. The average preoperative intermetatarsal angle was 13.9°, and the average hallux valgus angle was 29.7°. After surgery, the feet were corrected to an average intermetatarsal angle of 5.8° and an average hallux valgus angle of 11.9°. Sesamoid position was corrected from 2.1 before surgery to 0.5 after surgery. The results were also graded according to the Hallux Metatarsophalangeal Interphalangeal Score, and the functional and cosmetic outcomes were graded by the patient. Dissection of the plantar transverse ligament and release of the lateral capsule repositioned the tibial sesamoid and restored the biomechanics around the first metatarsophalangeal joint. There was no increased incidence of avascular necrosis of the first metatarsal head compared with the original technique.

Twenty-one patients with unstable medial malleolar, bimalleolar, or trimalleolar ankle fractures underwent open reduction and internal fixation of the medial malleolus with 4.5-mm polyglycolide screws. All lateral malleolar fractures were internally fixed with standard metallic implants.

Radiographic and clinical follow-up results were available on 16 of 21 patients. All fractures healed at an average of 3.4 months (range, 3–6 months), and there were no medial wound infections. Eight of 16 patients developed an inflammatory reaction to the biodegradable polyester at 3 to 4 months after implantation, including one who developed a sterile draining sinus tract. No surgical or nonsurgical treatment was required in those eight patients.

We conclude that whereas polyester screws yield union rates and functional results similar to those of metallic screws in the treatment of medial malleolar fractures, the use of polyglycolide screws is associated with an unacceptable rate of inflammatory reactions.

The kinematics of the first metatarsophalangeal joint were investigated in five embalmed cadaver feet (three normal, one hallux valgus, one hallux rigidus). Sagittal displacements of the first metatarsal relative to the proximal phalanx were measured during first metatarsophalangeal joint dorsiplantarflexion; first in intact cadavers, then with an intact capsule sans extracapsular soft tissues (hallux amputated at the first metatarsal cuneiform joint), and finally with a double-stem silicone prosthesis inserted. In the intact cadaver, the base of the metatarsal is raised by FMTP dorsiflexion in a manner similar to a cam. However, this effect ceased when the extracapsular soft tissues were removed. Silicone arthroplasty did not restore cam function.

Seven patients with supramalleolar nonunions after tibial plafond fractures underwent ankle arthrodesis combined with surgical treatment of the nonunion. Stabilization of the nonunion and the ankle consisted of medial and lateral plating for two hypertrophic cases and medial external fixation for five atrophic cases. Two of the atrophic nonunions were infected, and the distal tibia below the nonunion was resected and distraction osteogenesis from a proximal level was used to fill the resulting defect. Both the nonunion and ankle arthrodesis healed in six patients in an average of 7.9 months (range, 4–20 months). The nonunion failed to heal in one patient and required a below-knee amputation. The average cost of care was $66,491 per patient. Before surgery, the average patient ankle score was 25 (range, 15–50), and at a median of 35 months' follow-up the average score was 64 (range, 18–79 months). Three patients had scores in the “good” range, two in the “fair” range, one in the “poor” range, and one was rated a treatment failure. The SF-36 scores were significantly lower than age-matched population-based normal subjects. Limb salvage was possible in six of these seven patients, but the treatment times were long, complications frequent, and the cost of care high.

Functional ankle instability, orthoses, and passive resistive torque tolerated have not been researched. The purpose of the study was to evaluate the passive resistance torque exerted by a flexible and semirigid orthosis for individuals with chronic instability. Twenty-two subjects were evaluated on the passive ankle resistance unit during unbraced, flexible, and semirigid brace conditions. Data from the final three trials for each condition were analyzed using a multiple analysis of variance with repeated measures for resistive torque and inversion range of motion. The semirigid and flexible braces tolerated significantly greater torque forces and less inversion range than the unbraced condition (P < 0.000). External orthotic support, in particular that of a semirigid orthosis, may be beneficial toward reducing injury or be an effective prophylactic for the healthy population.

Five patients with concomitant distal tibia osteomyelitis and ankle sepsis with an open, draining wound were treated. All of the patients were men with an average age of 54.8 years. All of the bone infections were polymicrobial and had open draining wounds. A standardized protocol of radical soft tissue and bone debridement, soft tissue transfer, intravenous antibiotics, and delayed ankle fusion was employed. All five fusions were successful on first attempt, with an average time to fusion of 3.5 months. All patients were free of infection at an average follow-up of 27 months. We believe our aggressive treatment protocol can salvage these extremities and preclude amputation in properly selected cases.

The purpose of this study was to determine the possible mechanisms explaining the interindividual differences in foot orientations observed during running. Foot orientations, foot pressures, and ankle dorsiflexion and plantarflexion were simultaneously recorded on 12 male subjects running barefooted at 3.9 ± 0.6 m · sec⁻¹. The abduction of the forefoot was significantly related to the ankle dorsiflexion and plantarflexion velocities (P < 0.01 and P < 0.05, respectively). Because it was not possible, from pressure measurements, to determine differences in foot lever arm of runners, it is suggested that the interindividual variability of foot kinematics could not be explained by Bojsen-Moller's model, but could reflect differences in the lower limb stiffness control.

From 1981 to 1984, 131 reconstructive procedures and 113 Evans tenodesis procedures (1972–1984) were performed for patients with chronic instability of the ankle joint. From 1981 to 1985, 42 Christman/Snook procedures were performed for patients with isolated or combined subtalar instability.

Reevaluation was conducted for 223 patients (102 reconstructive procedures, 87 Evans tenodesis procedures, and 34 Christman/Snook tenodesis procedures). The follow-up protocol comprised standard and stress radiograms, subjective patient evaluation, and objective functional data.

No patient in either treatment group had clinically important ankle instability. Patients who had undergone the Evans tenodesis had a 3.3° mean less talar tilt than did patients treated with reconstructive procedure. Of 87 patients who underwent Evans tenodesis, 33 had a mean supination deficit of 7.5°. According to the ±100 points classification, 90% of the patients in both groups achieved good or excellent results.

For subtalar instability, the Christman/Snook techniques resulted in a mean supination deficit of 7.2° in 20 patients. Of 34 patients, 31 were rated good or excellent.

We studied six fresh frozen cadaver feet to define the three-dimensional motion of the hallux proximal phalanx in relation to the first metatarsal and to describe the contact features of the first metatarsophalangeal joint. Six tendons to the hallux were loaded to simulate dynamic loading of the hallux. A magnetic tracking system was used to monitor the three-dimensional movement of the proximal phalanx while the toe position was changed from a neutral position to full extension by adjusting the tendon loads. The average surface area was 0.38 ± 0.08 cm² in the neutral position; it decreased with toe extension and was the lowest (0.04 ± 0.03 cm²) at the full extension position. Contact distribution of the proximal phalanx did not change substantially throughout the arc of motion. However, for the metatarsal articular surface, the contact distribution shifted dorsally with increasing degrees of extension.

These data are consistent with the observation that chondral erosions associated with hallux rigidus and degenerative arthritis initially affect the dorsal articular surface of the metatarsal, and implant arthroplasty often fails from component loading dorsally. The current technique of determining joint contact characteristics is applicable not only for the first metatarsophalangeal joint but also other joints that have not been studied because of shortcomings with more conventional methods.

Phalangeal dislocations of toes are extremely rare in childhood and usually can be treated by closed reduction. We present a proximal interphalangeal dislocation of the fourth toe with an irreducible avulsion fracture of the middle phalanx requiring open reduction. To our knowledge concomitant avulsion fractures in this condition have not been reported thus far in pediatric patients. The pathological mechanism of this injury is discussed, and the significance of the plantar plate for joint stability is emphasized.