Faculty Bibliography

Because malunion (usually with dorsal elevation of the first metatarsal) has been reported after the treatment of severe hallux valgus deformities by proximal osteotomies, the current study was designed to compare the sagittal stability of six different metatarsal shaft osteotomies: the proximal crescentic, proximal chevron, Mau, Scarf, Ludloff, and biplanar closing wedge osteotomies. A plate was used in the biplanar closing wedge osteotomy; all others used screws for fixation. Ten fresh-frozen, human anatomic lower extremity specimens were used for each osteotomy. Failure loads were measured as units of force (newtons) and converted to pressure (kilopascals). Then the F-Scan system, which uses a thin insole to measure plantar pressure, was used to evaluate the pressure under the first metatarsal of seven volunteers using four types of shoes. According to the results, in patients with normal bone stock who are compliant, any of the four shoe types tested may be used after a Ludloff, Scarf, biplanar wedge (plantar screw fixation), or Mau osteotomy, but the wedge-based shoe should be used after a proximal crescentic or chevron osteotomy or for patients with severe osteopenic bone.

HYPOTHESIS/PURPOSE/OBJECTIVE:The purpose of this study was to determine the effectiveness of lower extremity peripheral nerve vein wrapping procedures in the management of patients with intractable lower extremity pain. The hypothesis was that nerve insulation through vein wrapping is effective in treating symptoms related to adhesive neuralgia, but not those secondary to intraneural damage. METHODS:We retrospectively reviewed 25 consecutive patients whose intractable chronic lower extremity peripheral neuralgia had been treated with revision neurolysis and vein wrapping. The 14 women and 11 men had an average age of 39 years (range, 21 to 53 years). Vein wrapping was performed using a saphenous vein autograft in 19 patients and a fetal umbilical vein in six patients. The average length of follow-up after vein wrapping was 24 months (range, 12 to 63 months). Assessment of pain and dysfunction was on a scale of 0 (no pain/dysfunction) to 10 (severe enough to prompt request for amputation and required use of a wheelchair). RESULTS:Pain scores improved from a preoperative average of 8.7 points (range, 6 to 10 points) to a postoperative average of 4.6 points (range, 0 to 10 points); dysfunction improved from a preoperative average of 7.3 points (range, 3 to 10 points) to a postoperative average of 4.4 points (range, 0 to 9 points). Although 17/25 patients were satisfied with the procedure, only 14/25 stated they would undergo the surgery again. All eight patients who exhibited no improvement had preoperative and intraoperative evidence of an idiopathic etiology and/or intraneural damage. Preoperatively, 18/25 patients could not work; postoperatively, that number improved to 8/25. CONCLUSIONS:Vein wrapping of lower extremity peripheral nerves is most effective in relieving symptoms related to adhesive neuralgia and less beneficial in the presence of intraneural damage. Although symptoms are rarely relieved completely, vein wrapping typically results in a substantial improvement in symptoms related to scar entrapment of peripheral nerves.

In triple arthrodesis performed for severe deformity and neuroarthropathy in poorly compliant patients with osteoporotic bone, fixation of the arthrodesis is critical. We biomechanically tested an alternative means of stabilization for calcaneocuboid fusions. In seven matched pairs of fresh-frozen cadaver feet, we removed the soft tissue from around the calcaneocuboid joint, except for the capsule, and we did not resect the articular cartilage. One joint of each pair was fixed with an oblique standard screw, and the contralateral joint was stabilized with an axial screw placed perpendicularly to the joint surface. Testing on an MTS Mini Bionix Test Frame (MTS Systems Corp., Eden Prairie, MN) demonstrated that the axial screw provided significantly higher initial stiffness and maximum load to failure. We concluded that an axial screw provided better fixation of the calcaneocuboid joint.

Autogenous saphenous vein graft wrapping of the tibial nerve has been described as an effective treatment option for failed tarsal tunnel decompression. Various theories have been proposed to explain how this method works, with little histologic evidence to date. A pathologic investigation of a sectioned nerve that had been previously wrapped provides some insight into these proposals.

To develop a classification of midtarsus deformities, clinical examination and weightbearing radiographs were used to evaluate 131 feet in 109 patients (average age, 59+/-11 years) with those deformities. Patients were classified into four types based on anatomic location of the maximum deformity. Type I (N=43) showed deformity at the metatarsocuneiform joints medially and the fourth and fifth metatarsocuboid joints laterally, with plantarmedial and/or medial prominence. Type II (N= 60) had deformity at the naviculocuneiform joint medially and the fourth and fifth metatarsocuboid joints laterally; plantarlateral prominence was characteristic, although one-third had isolated or additional medial prominences. Type III (N=17) had major deformity in the perinavicular region, with a prominence plantarcentrally or plantarlaterally. Type IV (N=11) had deformity at the transverse tarsal joints with variable prominences. Each type was further subdivided into stages A, B, and C based on the severity of the deformity. In stage B, the midtarsus was coplanar with the metatarsocalcaneal plane. In stage A, the midtarsus was above this plane. In stage C, the midtarsus was below this plane. We concluded that midtarsus deformities can be classified as one of four types and one of three stages. Additional study is warranted to correlate this system with prognosis and treatment for this pathologic process.

Dancing en pointe requires the ballerina to stand on her toes, which are protected only by the pointe shoe toe box. This protection diminishes when the toe box loses its structural integrity. The objectives of this study were 1) to quantify the comparative structural static and fatigue properties of the pointe shoe toe box, and 2) to evaluate the preferred shoe characteristics as determined by a survey of local dancers. Five different pointe shoes (Capezio, Freed, Gaynor Minden, Leo's, and Grishko) were evaluated to quantify the static stiffness, static strength, and fatigue properties (cycles to failure) of the shoes. Under axial loading conditions, the Leo's shoe demonstrated the highest stiffness level, and the Freed shoe exhibited the least strength. Under vertical loading conditions, the Leo's and Freed shoes demonstrated the highest stiffness levels, and the Gaynor Minden and Freed shoes exhibited the highest strength. Fatigue testing highlighted the greatest differences among the five shoes, with the Gaynor Minden demonstrating the highest fatigue life. Dancers rated the top five shoe characteristics, in order of importance, as fit, comfort, box/platform shape, vamp shape, and durability and indicated that the "best" shoe is one that "feels right" and permits artistic maneuvers, not necessarily the strongest or most durable shoe.

To test the hypothesis that a plate applied to the plantar (tension) side of the medial midfoot provides stronger fixation than midfoot fusion with screw fixation, we biomechanically compared the two constructs for midfoot fusion. We created a model of midfoot instability in eight matched pairs of cadaver legs by section of joint capsule, ligaments, and tendons about Lisfranc's joints, and then performed a load-to-failure study to compare the fixation provided by a plantarly applied third tubular plate with that by cortical screws. After an initial load deformation curve to 1000 N was obtained, specimens were cyclically loaded at 200 to 750 N for 3000 cycles and then loaded to failure (screw pullout, fracture, or deformation >3 mm). Comparing the plantar plate and midfoot fusion with screw fixation constructs, a plate applied to the plantar (tension) aspect of the medial midfoot provides a stronger, sturdier construct than does midfoot fusion with screw fixation.