Foot & Ankle International

Twenty-three patients (twenty-seven feet) with either a primary or staged pantalar arthrodesis or a tibiotalocalcaneal arthrodesis were evaluated to determine their clinical status. The main indication for the operation was the presence of severe pain unresponsive to non-operative treatment. Fourteen feet (twelve patients) had a pantalar arthrodesis; a fusion of the ankle, subtalar, talonavicular and calcaneocuboid joints. Half the feet in this group had either a triple arthrodesis or an ankle fusion performed at an earlier time. The remaining seven feet had all joints fused during the same operation. Thirteen feet (eleven patients) had a tibiotalocalcaneal arthrodesis. Two of these feet had an ankle arthrodesis performed four and six years previously. The other eleven had the ankle and subtalar joints fused during the same operation. All patients were followed for a mean of fifty-five months (14 to 159 months) from the time of their final arthrodesis procedure. Overall, twenty-three of the twenty-seven feet achieved a solid arthrodesis of all joints operated upon. Four feet had a failure of fusion of only a single joint and all were in the pantalar group. The mean time to radiographic fusion was twenty-three weeks and resulted in a plantigrade foot with an average tibia-floor angle of 87°. Complications occurred in ten feet (37%); of which there were three deep infections; two ankles and one subtalar joint. These arthrodeses procedures resulted in marked relief of the patients' preoperative pain, the main indication for performing the surgery. Postoperatively there was no pain in eleven feet, mild occasional pain in thirteen feet, and moderate pain in only three feet. However, when all parameters of our clinical rating scale were evaluated, only five patients had an excellent clinical result, nine were rated good, three were rated fair and six patients had a poor result. These operations must be considered to be salvage procedures. They are technically difficult to perform and major complications may occur. Pain relief appears to be the main indication for performing these operations, and may account for whatever improvement occurs in the patient's function.

The incidence of calcaneal fracture has been slowly increasing; however, the ideal treatment for displaced intra-articular fracture is not available yet, even though the fracture brings frequent complication and disability. Between April 1991 and March 1998, we treated 103 displaced intra-articular calcaneal fractures of 92 patients surgically with limited posterior incision, modified Gallie approach. There were thirty-seven tongue-type fractures, fifteen tongue-type fractures with moderate comminution, nineteen joint-depression fractures, twenty-nine joint-depression fractures with moderate comminution, and three extensively comminuted fractures. The fracture fragments were fixed mainly with partly threaded small cancellous screws or Steinmann pins without any bone graft. Ankle and subtalar motion was permitted immediately if fixation were stable enough. Otherwise, a short period of cast immobilization was utilized. With a mean follow-up of 28 months (range, 12 to 66 months), eighty six percent of feet had no pain or only occasional pain not requiring medication. Using American Orthopedic Foot and Ankle Society hindfoot score system for assessment, ninety percent of feet rated as good to excellent. We used “Circle draw test” for evaluation of subtalar motion during follow-up visitation and found eight-seven percent of feet showed good to excellent correlation with the functional recovery. We recommend a limited posterior incision for reduction and internal fixation of displaced intra-articular calcaneal fractures. For displaced intra-articular fractures with three or four large fragments without further comminution and without a displaced fracture of the calcaneal cuboid joint, this method is particularly useful. We also recommend a Circle draw test for evaluation of subtalar joint motion as well as an indicator of functional recovery after displaced calcaneal fractures.

This prospective, randomized study compares the treatment of an interdigital neuroma (IDN) by the standard resection operation with a technique in which the IDN is transposed into the inter-muscular space between the adductor hallucis and the interossei muscles after division of the digital nerves distal to the IDN. The resection group contained 22 patients and 22 neuromas and the transposition group contained 22 patients and 23 neuromas. An interviewer, blinded as to the operative technique used, telephoned each patient preoperatively, and at 1 month, 3 months, 6 months, 12 months, and 36–48 months postoperatively. The interviewer recorded the patient's reported pain level on a numerical rating scale of 0 to 100. In the resection group the average pain level was slightly lower through the first 6 month period, but at the 12 month review the resection group had a slightly higher average pain level. At the 36–48 month survey the resection group again reported a greater average pain level and fewer asymptomatic patients.

It was concluded that it is unnecessary to excise the IDN to obtain excellent relief of pain. It was also concluded that transposition of the IDN into an intermuscular position between the adductor hallucis and the interossei muscles produced significantly better long term results than did the standard resection operation.

Twenty cadaver fifth metatarsals were harvested from cadaver feet. They were then sectioned coronally in three locations. The cortical thickness (medial, lateral, dorsal, and plantar) and the intra-medullary canal diameter (dorsoplantar and mediolateral) were measured at the three sectional sites. The intra-medullary canal of six specimens was outlined with radiopaque solder wire. The canal was then examined radiographically with the lateral and dorsoplantar views. A lateral bow on the dorsoplantar view was observed in some specimens, which could contribute to surgical complications. On lateral view the intramedullary canal appeared straight in all specimens. The canal projects at least partially into the fifth metatarsal cuboid joint. When considering intra-medullary fixation a surgeon must take into account quality of bone stock and bowing of the canal. A bowed intra-medullary canal lends to vulnerability of the medial cortex at roughly mid-shaft of the fifth metatarsal. The canal has a narrower diameter in the dorsoplantar dimension than the mediolateral dimension. The cortical thickness was found to be less in the dorsal and plantar areas of the fifth metatarsal when compared to medial and lateral cortex. All of these findings lead to causes for complication in intra-medullary fixation of the fifth metatarsal.

A three-dimensional biomechanical model was used to calculate the mechanical response of the foot to a load of 683 Newtons with the subtalar joint in the neutral position, at five degrees of pronation, and at five degrees of supination. Pronation causes the forefoot to evert, increasing the load borne by the first metatarsal. This results in a 47% increase in the moment about the talonavicular joint and a 58% increase in the moment about the navicular-medial cuneiform joint. Subtalar joint supination causes the forefoot to invert and results in a 55% increase in the moment about the calcaneal-cuboid joint.

This study analyzed the ability of an in-shoe plantar pressure measurement system to provide repeatable measurements of postural sway data for both healthy and clinical patients. Each participant's in-shoe pressure data were recorded for three trials during each test session during quiet stance. Healthy individuals (n=9) participated on three consecutive days while clinical participants (n=5) were tested on one day. Nine response variables were measured to assess their postural stability. Intra-subject measures were evaluated using the Kerlinger reliability procedure. Values provided directly by the Parotec System® for a single day of testing yielded the following average coefficients: r = 0.95 (left), r = 0.97 (right) with mean coefficient values from the three day tests of: r = 0.98 (left), r = 0.98 (right). Variables calculated from raw data on a single day produced mean coefficients of: r = 0.77 (left), r = 0.76 (right) and over three days of: r = 0.65 (left), r =0.66 (right). The ability to record highly reproducible data of postural sway parameters should assist clinicians to treat patients more confidently for balance deficiencies.

The purpose of the study was to examine the plantar loading changes during 5 gradient conditions on a treadmill (−15%, −8.5%, Level, 8.5%, 15%) for 20 participants using the Pedar® in-shoe pressure measurement system. The measurement system uses EMED insoles, each consisting of 99 capacitive sensors, sampled at 50 Hz. Data was collected from the last 20 seconds at each gradient condition while participants walked. As the treadmill gradient increased, loading (peak pressure [PP] and peak force [PF]) increased in the hallux and 1st metatarsal regions and decreased in the heel region. With negative gradients, loading (PP and PF) increased in the heel region and decreased in the 4th and 5th metatarsal regions.

The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between calcaneus and tibia was higher in the first phase (from heel strike to midstance) compared with the second phase (from midstance to take-off). This finding is in contrast to previous in-vitro studies but may be explained by the higher vertical loads of the present in-vivo study. Thus, movement coupling measured at the bone level changed throughout the stance phase of running and was found to be far more complex than a simple mitered joint or universal joint model.

The need for measuring the mobility of the first ray has been identified. The purpose of this study was to test the reliability and validity of a device built to measure the relative vertical displacement of the first ray. Twenty fresh frozen cadaver feet were sampled (mean age of donor was 70 ± 13 years). Dorsal mobility of the first ray was measured by device over three trials of repeated loading using 20 N, 35 N, 55 N and 85 N of force. Radiographs served as the criterion standard for validation of the device. Vertical displacement was measured from x-ray by a digitizing procedure that recorded movement of the first ray during loading. Reliability of the device assessed by intraclass correlation coefficients (ICC) was .98 with standard errors of the measurement calculated to be 0.35 mm. A correlation of agreement value of .97 was determined for the two methods of measurement. Analysis of variance testing found a significant interaction between force and method of measurement. Tukey post-hoc analysis found no difference (F < 1.70) between the two methods of measuring first ray displacement in cadaver specimens when the force applied did not exceed 55 N. At 85 N of force (F = 10.05), unwanted movement of the second metatarsal caused the device to overestimate the amount of displacement that occurred specific to the first ray. This measure of first ray mobility should help clinicians and researchers to better investigate foot pathology resulting from faulty mechanics of the first ray.

Specialty Day of the European Foot and Ankle Society (EFAS) June 6, 1999, at the 4th Congress of the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) from June 3–8 in Brussels, Belgium.