Tibialis anterior rupture: acute and chronic.

Rupture of the tibialis anterior tendon is an unusual injury. Most ruptures occur in elderly men with a history of minor trauma. The sudden occurrence of a "foot drop" is often the presenting symptom. The diagnosis is frequently delayed. The acute rupture is best treated by direct repair. Treatment of the chronic rupture is tailored to the patient. In relatively inactive patients, either a polypropylene ankle-foot orthosis or no treatment at all is indicated. In the more active patient, a reconstruction using extensor hallucis longus helps restore dorsiflexion function.

Surgery for hallux valgus with proximal crescentic osteotomy causes variable postoperative pressure patterns.

We prospectively evaluated the results of plantar pressure measurement in 32 patients (43 feet) who had a proximal crescentic osteotomy of the first metatarsal with a modified McBride procedure. The procedure's effectiveness in increasing weightbearing under the first ray, decreasing pressure under the second metatarsal head, and the relationship of radiographic measurements of first metatarsal length and position to postoperative pressure measurements were evaluated. Mean followup was 29 months. Average peak pressure increased postoperatively under the second metatarsal head. Almost identical numbers of feet had first metatarsal elevation (12) or depression (11) greater than 2 mm. Radiographic evidence of first metatarsal elevation, but not shortening, was associated with diminishing peak pressure and pressure-time integral under the first metatarsal head and hallux. Five feet that had first metatarsal elevation greater than 2 mm had new second metatarsal transfer lesions develop. Eleven feet preoperatively and nine feet postoperatively had symptomatic second metatarsal pressure lesions. One lesion persisted, 10 resolved, and eight new lesions developed. Control of the crescentic osteotomy in the sagittal plane was unpredictable despite modification of the surgical technique to plantarly displace the distal segment of the first meta-tarsal. Although average second metatarsal pressure increased postoperatively, there was variability in the correlation of radiographic change and pedobarographic measurements.

The effect of screw type on the biomechanical properties of SCARF and crescentic osteotomies of the first metatarsal.

The basilar crescentic osteotomy is a popular method for correcting moderate to severe hallux valgus. However, inadvertent dorsiflexion of the osteotomy can result from intraoperative malposition or from malunion after fixation failure. The mechanical properties of osteotomies are dependent on the nature of the osteotomy and the type of fixation. This study examines the mechanical properties of the SCARF and crescentic osteotomies of the first metatarsal by using a cannulated asymmetric pitched screw or AO cancellous screws. Sixteen human cadaveric first metatarsal specimens were tested in plantar to dorsiflexion cantilever bending by using a mechanical testing machine. The data was compared with our recent work on the mechanical properties of the SCARF and crescentic osteotomies. Ultimate load and stiffness of the SCARF osteotomy were superior to the crescentic osteotomy but were not dependent on screw type. Screw type was a prominent factor in the stiffness but not in the strength of the crescentic osteotomy. The ultimate load and the stiffness of SCARF osteotomy fixed with the cannulated asymmetric pitched screws were not significantly different compared with AO screws (ultimate load, 124.6 N [SD = 56.8] v 105.3 N [SD = 57.0]; stiffness, 52.0 N/mm [SD = 48.0] v 31.8 N/mm [SD = 19.0]). Modes of failure were fracture of the cortical bone bridge between the screw hole and the osteotomy in all crescentic osteotomies and fracture of the proximal dorsal bridge in all SCARF osteotomies. The superior mechanical properties of the SCARF osteotomy, fixed with cannulated asymmetric pitched screws, make this a more secure construct, with less risk of malunion than the crescentic osteotomy. Stiffness is an important mechanical factor that helps distinguish the mechanical performance of different osteotomy techniques.