Andrea Cracchiolo

Rupture of the posterior tibial tendon. Evaluation of injury of the spring ligament and clinical assessment of tendon transfer and ligament repair.

Eighteen of twenty-two patients who were having a tendon transfer to treat rupture of the posterior tibial tendon had evidence of injury to the spring ligament. The injury consisted of a longitudinal tear in the ligament in seven patients, a lax ligament without a gross tear in seven, and a complete rupture of the ligament in four. The ruptured posterior tibial tendon was treated with transfer of the flexor digitorum longus in twenty of the twenty-two patients. A variety of methods were used to repair the ligament. It is essential to determine the status of the spring ligament when patients are managed for rupture of the posterior tibial tendon. Patients who have a torn or lax spring ligament in addition to the ruptured posterior tibial tendon may have more severe abnormalities of the hindfoot than those who have only a ruptured tendon.

Clinical results after tarsal tunnel decompression.

We reviewed the clinical results for thirty patients (thirty-two feet) who had had exploration and decompression of the posterior tibial nerve for the treatment of tarsal tunnel syndrome between 1982 and 1990. The average duration of follow-up was thirty-one months (range, twenty-four to 118 months). Most of the patients were female, and the average age was forty-seven years (range, thirteen to seventy-two years). Over-all, only fourteen (44 percent) of the thirty-two feet benefited markedly from the operative procedure (a good or excellent result). Of the five patients (five feet) who were completely satisfied, three had another lesion (a ganglion cyst, an accessory navicular bone, or a medial talocalcaneal coalition) in or near the tarsal tunnel that had been treated at the same time. Eleven patients (twelve feet [38 percent]) were clearly dissatisfied with the result and had no long-term relief of the pain (a poor result). The pain was decreased in six feet (19 percent), but the patients still had some pain and disability (a fair result). There were four complications (13 percent): three wound infections and one delay in wound-healing. Twenty-two feet had had preoperative electrodiagnostic studies; the results of eighteen studies were considered abnormal and supportive of a diagnosis of tarsal tunnel syndrome. However, there was no correlation between the clinical outcome at the latest follow-up visit and the results of these studies. Over-all, the patients in the current series had less improvement than those who have been reported on previously.2

Arthrodesis of the ankle in patients who have rheumatoid arthritis.

We reviewed thirty-two arthrodeses of the ankle in twenty-six patients who had rheumatoid arthritis. In seventeen patients (eighteen ankles), a compression arthrodesis was done and external fixation was used. In eight patients (twelve ankles), we used internal fixation with 6.5-millimeter cancellous-bone screws. In the remaining patient, an arthrodesis with external fixation was done in one ankle and internal fixation was used in the other ankle; data for the appropriate ankle are included in each group. The patients were followed for an average of thirty-three months. The two groups were comparable with respect to age, sex, preoperative medications, and severity of disease. The average time to fusion was nineteen weeks in the compression arthrodesis group and seventeen weeks in the internal fixation group. Of the nineteen ankles that had a compression arthrodesis, four failed to fuse; all of the failures were associated with infection. Infection developed in two additional patients, there was malposition of the fusion in three patients, and neurapraxia developed in three patients. Of the thirteen ankles that had internal fixation, three ankles failed to fuse; one of the failures was associated with infection. Infection developed in one additional ankle. In two patients, the ankle fused in excessive valgus. Comparison of the two groups revealed comparable rates of fusion: fusion occurred in fifteen of the nineteen ankles in the group that had compression arthrodesis and in ten of the thirteen ankles in the group that had internal fixation. The method of arthrodesis did not affect the time to fusion or the rate of complications.(ABSTRACT TRUNCATED AT 250 WORDS)

A Method for Measuring Foot Pressures Using a High Resolution, Computerized Insole Sensor: The Effect of Heel Wedges on Plantar Pressure Distribution and Center of Force

A new, high resolution, pressure-sensitive insole was tested and found to provide reproducible measurements of static and dynamic plantar pressures inside the shoe of normal test subjects under certain conditions. However, calibration between separate sensors was poor and the sensor pads showed significant wear with use. This system was also used to investigate the effect of heel wedges on plantar foot pressure to determine whether this system was sensitive enough to detect the effect of a gross shoe modification on plantar foot pressure. Medial heel wedges decreased plantar pressures under the first and second metatarsals as well as under the first toe, and shifted the center of force laterally in all portions of the foot. Lateral heel wedges decreased pressures under the third, fourth, and fifth metatarsals, increased pressures under the first and second metatarsals, and shifted the center of force medially in all portions of the foot. Our evaluations indicate that it is possible to measure static and dynamic plantar foot pressures within shoes and to study the possible effect of shoe modifications on plantar pressures in controlled gait trials.

Arthroplasty of the first metatarsophalangeal joint with a double-stem silicone implant. Results in patients who have degenerative joint disease failure of previous operations, or rheumatoid arthritis.

Sixty-six patients who had a total of eighty-six double-stem silicone implants in the first metatarsophalangeal joint were followed prospectively for an average of 5.8 years (range, two to fifteen years). There were two groups of patients: thirty-four patients (thirty-seven implants) who had degenerative joint disease (including those who had hallux rigidus or in whom a previous operation on a bunion had failed) and thirty-two patients (forty-nine implants) who had rheumatoid arthritis. The implants were used only if the patient was a candidate for an excisional arthroplasty or an arthrodesis; they were not used in patients who wished to maintain or adopt very active use of the foot (such as in running, jogging, and tennis) or to wear very high heels. Twenty-eight (82 per cent) of the thirty-four patients in the first group were completely satisfied and three (9 per cent) were somewhat satisfied. However, three patients (9 per cent), all of whom had had a failed bunionectomy, were dissatisfied; the ages of these three patients were less than the average age of all patients in the first group. Radiographs showed a fracture in three implants, but the patients had a good clinical result and an additional operation was not warranted. Twenty-seven (84 per cent) of the thirty-two patients in the second group were completely satisfied, four (13 per cent) were somewhat satisfied, and one (3 per cent) was dissatisfied. Radiographs showed a fracture in five implants. Four of the implants caused no symptoms, and the result was good; the fifth one was fragmented and was removed because of symptoms. Radiographs showed radiolucent areas around the implant and hypertrophic changes in many patients. There was no evidence of synovitis, such as that caused by silicone, either clinically or radiographically. We found that the double-stem silicone implant was effective in reconstructing the first metatarsophalangeal joint but emphasize our belief that it should be used only in carefully selected patients.

The effect of chevron osteotomy with lateral capsular release on the blood supply to the first metatarsal head.

The chevron osteotomy is one of the most widely used distal metatarsal osteotomies for the treatment of hallux valgus in adults. Because the osteotomy interrupts the intraosseous blood supply to the metatarsal head, there has always been a concern that the operation could produce osteonecrosis of the metatarsal head, particularly if the important extraosseous blood supply was also damaged. We used latex injection and a modified Spalteholz technique in cadaveric specimens to demonstrate the effect of the chevron osteotomy, with and without lateral capsular release, on the vascular supply to the first metatarsal head. We found an extensive network of extraosseous vasculature to the metatarsal head both proximal and distal to the site of the osteotomy. Both of these vascular networks were preserved when the osteotomy was done properly. Also, an extensive plantar and plantar lateral network of vessels provided circulation to the head. Potential technical flaws in the performance of the osteotomy included cutting of the first dorsal metatarsal artery by overpenetration of the saw blade and incorrect placement of the proximal arms of the osteotomy inside the joint capsule. These technical errors, alone or in conjunction with extensive capsular stripping, can result in damage to the vessels that supply the metatarsal head.

The Use of a 95° Blade Plate and a Posterior Approach to Achieve Tibiotalocalcaneal Arthrodesis

Various types of internal fixation have been used to achieve arthrodesis of both the ankle and subtalar joints. We have investigated the use of a standard 95° angled blade plate as a method of more rigid internal fixation to achieve arthrodesis of these joints. The purpose of this retrospective study was to review our clinical and radiographic results in adults using a blade plate applied through a posterior approach to fuse the ankle and subtalar joints. Methods: Between April 1995 and June 2000, 10 tibiotalocalcaneal arthrodeses were performed using a posterior approach and a blade plate for internal fixation. There were 10 adults (five men and five women) whose average age was 64 years (range, 42 to 80 years). The indication for the procedure was severe pain which was unresponsive to nonoperative management in patients with arthritic joints. Preoperative diagnoses included six patients with post-traumatic arthritis, two with primary degenerative arthritis, one with rheumatoid arthritis, and one with post-polio deformity. An average of 1.7 previous operations had been performed on the affected ankle. Results: Clinical and radiographic follow-up was performed for all patients at an average of 37 months (range, 12 to 71 months) postoperatively. All 10 patients achieved a solid fusion. The mean time to radiographic fusion was 14.5 weeks (range, 9 to 26 weeks). The operation resulted in plantigrade feet in all patients with an average tibia-floor angle of 2.3° of dorsiflexion and an average of 5° of hindfoot valgus. Patients had excellent pain relief, however function did not improve as much. Complications occurred in three patients. One patient required a small split-thickness skin graft for wound healing, one experienced a transient posterior tibial nerve neuropraxia, and one developed a deep venous thrombosis in the nonoperative leg at six weeks postoperatively. Three patients required removal of the blade plate because of discomfort, which promptly cleared. Conclusions: Arthrodesis provides excellent pain relief for patients with painful arthritic deformities of the ankle and subtalar joints. Using a posterior approach, a blade plate for internal fixation and bone grafts resulted in a solid fusion for all our patients. This method is particularly effective in large patients with a mild-moderate hindfoot deformity.

Stability of an ankle arthrodesis fixed by cancellous-bone screws compared with that fixed by an external fixator. A biomechanical study.

Twenty-three fresh-frozen human specimens were subjected to ankle arthrodesis and fixation with two cancellous-bone screws. The specimens were then subjected to four newton-meters of manually applied tibial torque, plantar flexion-dorsiflexion moment, and medial-lateral bending moment; relative rotation between the tibia and the talus was recorded for each mode of testing. A Calandruccio triangular compression device was then applied to threaded pins penetrating the tibia and talus, the screws were removed, and the test sequence was repeated. Tibiotalar motions recorded with both systems of fixation were markedly affected by the quality of the bone. When less than 2 degrees of total tibiotalar rotation was recorded in response to four newton-meters of manually applied internal-external tibial torque, all specimens demonstrated less torsional rotation with the screw fixation than with the external fixator. The mean rotations produced by medial-lateral bending moment were equivalent for both systems of fixation. When torsional rotations with the use of screw fixation were greater than 2 degrees, all specimens demonstrated more torsional rotation with the screws than with the external fixator, and all but one specimen had more medial-lateral rotation with the screws than with the fixator. For applied plantar flexion-dorsiflexion moment, twenty-two of the twenty-three specimens demonstrated more rotation with the Calandruccio fixator than with the screws; this was due in part to motion permitted at the hinge points of the frame itself.

Magnetic resonance imaging of plantar plate rupture

Degenerative plantar plate failure is an under-recognized cause of lesser metatarsalgia. We performed magnetic resonance imaging (MRI) with a small receiver coil in 13 patients in whom plantar plate ruptures of the second or third metatarsophalangeal joint were clinically suspected. In eight patients, MRI showed focal hyperintensity in the plantar plate that was interpreted as a rupture of the plate. Ruptures were confirmed in all five patients who underwent an operative procedure to treat the unstable, painful metatarsophalangeal joint. MRI is a noninvasive technique that can visualize plantar plate abnormalities and aid the clinical evaluation of problematic lesser metatarsalgia.

Strength of Fixation Constructs for Basilar Osteotomies of the First Metatarsal

Twenty-four pairs of fresh-frozen human feet had a proximal osteotomy of the first metatarsal that was fixed using either screws, staples, or K wires. Each metatarsal was excised and the specimen was loaded to failure in a cantilever beam configuration by applying a superiorly directed force to the metatarsal head using an MTS ser-vohydraulic test machine. Specimens with a crescentic osteotomy that were fixed using a single screw demonstrated higher mean failure moments than pairs that were fixed with four staples or two K wires; staples were the weakest construct. All specimens fixed with staples failed by bending of the staples without bony fracture; all K wire constructs but one failed by wire bending. Chevron and crescentic osteotomies fixed with a single screw demonstrated equal bending strengths; the bending strength of an oblique osteotomy fixed with two screws was 82% greater than for a crescentic osteotomy fixed with a single screw. Basilar osteotomies of the first metatarsal are useful in correcting metatarsus primus varus often associated with hallux valgus pathology. Fixation strength is an important consideration since weightbearing forces on the head of the first metatarsal acting at a distance from the osteotomy site subject the construct to a dorsiflexion bending moment, as simulated in our tests. Our results show that screw fixation is the strongest method for stabilizing a basilar osteotomy. Based upon the relatively low bending strengths of the staple and K wire constructs, we would not recommend these forms of fixation. If, for some reason, these are the only methods of fixation available, then use of a short leg cast and limited weightbearing for several weeks postoperatively should be considered.