Faculty Bibliography

BACKGROUND:The purposes of this retrospective study were to review the results of isolated subtalar arthrodesis in adults and to identify factors influencing the union rate. The hypotheses were that (1) the overall outcome is acceptable but is not as favorable as previously reported, (2) complication rates, especially the nonunion rate, are higher than previously reported, and (3) factors contributing to a less favorable union rate can be identified. METHODS:Between January 1988 and July 1995, 184 consecutive isolated subtalar arthrodeses were performed in 174 adults (115 men and fifty-nine women) whose average age was forty-three years (range, eighteen to seventy-nine years). Eighty patients (46 percent) were smokers. The indications for the procedure included posttraumatic arthritis after a fracture of the calcaneus (109 feet), a fracture of the talus (thirteen feet), or a subtalar dislocation (thirteen feet); primary subtalar arthritis (thirteen feet); failure of a previous subtalar arthrodesis (twenty-eight feet); and residual congenital deformity (eight feet). Rigid internal fixation with one or two screws was used for all feet. Bone graft was used in 145 feet; the types of graft material included cancellous autograft (ninety-four feet), structural autograft (twenty-nine feet), cancellous allograft (seventeen feet), and structural allograft (five feet). Bone graft was not used in the remaining thirty-nine feet. RESULTS:Clinical and radiographic follow-up examinations were performed for 148 (80 percent) of the 184 feet at an average of fifty-one months (range, twenty-four to 130 months) postoperatively. The average ankle-hindfoot score according to the modified scale of the American Orthopaedic Foot and Ankle Society (maximum possible score, 94 points) improved from 24 points preoperatively to 70 points at follow-up. Thirty feet had clinical evidence of nonunion. The union rate was 84 percent (154 of 184) overall, 86 percent (134 of 156) after primary arthrodesis, and 71 percent (twenty of twenty-eight) after revision arthrodesis. The union rate was 92 percent (ninety-three of 101 feet) for nonsmokers and 73 percent (sixty-one of eighty-three feet) for smokers (p < 0.05). Intraoperative inspection revealed that 42 percent (seventy-eight) of the 184 feet had evidence of more than two millimeters of avascular bone at the subtalar joint; all thirty nonunions occurred in this group (p < 0.05). A nonunion occurred in three of the five feet that had been treated with structural allograft and in two of the six feet in which the subtalar arthrodesis had been performed adjacent to the site of a previous ankle arthrodesis. After elimination of the subgroups of feet in patients who smoked, those that had had a failure of a previous subtalar arthrodesis, those that had been treated with a structural graft, and those that had had the subtalar arthrodesis adjacent to the site of a previous ankle arthrodesis, the union rate improved to 96 percent (seventy-three of seventy-six). Complications other than nonunion included prominent hardware requiring screw removal (thirty-six of 184 feet; 20 percent), lateral impingement (fifteen of 148 feet; 10 percent), symptomatic valgus malalignment (five of 148 feet; 3 percent), symptomatic varus malalignment (four of 148 feet; 3 percent), and infection (five of 184 feet; 3 percent). CONCLUSIONS:To the best of our knowledge, the present study includes the largest reported series of isolated subtalar arthrodeses in adults. Our results suggest that the outcome following isolated subtalar arthrodesis is not as favorable as has been reported in previous studies. The rate of union was significantly diminished by smoking, the presence of more than two millimeters of avascular bone at the arthrodesis site, and the failure of a previous subtalar arthrodesis (p < 0.05 for all). Other factors that probably affect the union rate include the use of structural allograft and performance of the arthrodesis adjac

We treated 24 patients (18 women, six men; average age, 46.4 years; (range, 28 to 66 years) with fusion of the hallux metatarsophalangeal (MTP) joint using bone graft for the restoration of the length of the first ray. This procedure was performed after bone loss subsequent to previous surgeries for the correction of hallux valgus and hallux rigidus with: silastic arthroplasty (11), bunionectomy and distal metatarsal osteotomy (six), Keller resection arthroplasty (five), and total joint replacement (two). The indication for performing the arthrodesis with bone graft was a short first metatarsal, and associated metatarsalgia of the lesser metatarsals in addition to a painful MTP joint with or without deformity. This bone loss was associated with avascular necrosis of the first metatarsal (nine patients) and with osteomyelitis (seven patients). Of the 24 patients, 14 underwent additional concurrent surgery for correction of hammer toes (10), excision of a Morton's neuroma (two), and lesser metatarsal osteotomy (two). All patients were examined clinically and radiographically at a mean interval of 62.7 months after surgery (range, 26 to 108 months). The patients were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) hallux and MTP 100-point outcome scale. Arthrodesis occurred in 19/24 patients (79.1%) at a mean of 13.3 weeks (range, 11 to 16 weeks), and the first ray was lengthened by a mean of 13 mm (range, 0 to 29 mm). Of the five nonunions, two were asymptomatic, and three were subsequently revised successfully, with arthrodesis occurring at a mean of 10.7 weeks. Complications included one deep infection requiring intravenous antibiotics for treatment of osteomyelitis and two minor superficial wound infections. The mean AOFAS score improved from 39 points (range, 22 to 60 points) to 79 points (range, 64 to 90 points). All patients were satisfied with the final outcome of treatment and stated that they would undergo the surgical procedure again. We concluded that arthrodesis of the hallux MTP joint with bone graft to restore bone loss and length of the first ray may be a worthwhile procedure despite the technical difficulty and the high rate of nonunion.

BACKGROUND:To analyze the effects of multiple preoperative, intraoperative, and postoperative factors on the intermediate results of triple arthrodesis, we focused on preoperative deformity, preoperative diagnosis, degree of clinical and radiographic correction, and arthritis of the ankle. METHODS:Between 1987 and 1995, 160 patients were managed with a total of 183 triple arthrodeses. Patients who had an infection or neuroarthropathy or who were managed with a revision arthrodesis were excluded from our study. Of the 160 patients, 111 (132 feet) who had been followed for a minimum of two years formed our study group. Each patient had an arthrodesis with rigid screw fixation and realignment of the joint surfaces without resection of wedges. The average duration of follow-up was 5.7 years (range, 2.0 to 10.8 years). RESULTS:As seen radiographically, arthritis of the ankle was significantly more severe postoperatively than preoperatively (p<0.01), although patient satisfaction was not associated with the presence of arthritis. On a scale (not a visual analog) of 0 (not satisfied) to 10 (completely satisfied), overall satisfaction averaged 8.3 points (range, 0 to 10 points). The postoperative modified ankle-hindfoot score of the American Orthopaedic Foot and Ankle Society averaged 60.7 points (range, 0 to 94 points). There was a significant association (p = 0.001) between satisfaction of the patient and postoperative alignment. Ten patients had a total of eleven complications: four superficial wound problems, three nonunions, one case of superficial peroneal neuritis, one case of Charcot-like neuroarthropathy of the foot (in a patient in whom diabetes developed during the follow-up period), one rupture of the Achilles tendon, and one case of peroneal tenosynovitis. Of the 111 patients, 101 (91 percent) stated that they would have the procedure again under similar circumstances, and this response was independent of the preoperative diagnostic or deformity group. CONCLUSIONS:Triple arthrodesis for the treatment of various deformities and etiologies is effective in relieving pain and improving functional deficits. Although a high prevalence of subsequent arthritis of the ankle was noted clinically and radiographically, we could detect no association between satisfaction of the patient and arthritis.

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 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.

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.