Introduction: Planovalgus is a clinical deformity on weightbearing. Extra-articular calcaneal lengthening osteotomy, is a recognised surgical treatment for symptomatic flat feet. The aim of this study was to assess the difference in pedal pressures and radiographic parameters in the assessment of patients undergoing lateral column lengthening for planovalgus deformity.

Methods: Operative records of one surgeon were reviewed over a 5 year period to identify those who had undergone a lateral column lengthening procedure. 10 patients, 14 feet were identified. Patients were recalled for post-operative pedobarography and pre- and post-operative X-rays were identified. Peak plantar pressures were measured at 8 sites and a line plotted to show maximum deviation of pressure progression from the anatomical axis of the foot. 5 angles on X-rays were measured by 2 observers on 2 occasions.

Results: Difference in pressure under the 3^rd metatarsal head (p=0.0004), hallux (p=0.02) and medial midfoot (0.001) suggested a highly significant change. Results for the first (p=0.41) and second (p=0.91) metatarsal heads showed no change. The centre of pressure maximum deviation, plotted using a line drawn between the second toe and the rear of the heel was found to be highly significant postoperatively (p=0.00051) indicating that load bearing shifted from medial to lateral. Changes in X-ray angles of the lateral talo-1^st metatarsal angle(p=0.006), calcaneal pitch(p=0.002), AP talocalcaneal angle(0.0001) and talonavicular coverage(p=0.003) were all highly significant.

Discussion: Lateral lengthening in adolescent feet changes the pedal pressures in an advantageous way.

The relationship between hindfoot deformity and forefoot pressure was assessed in 28 rheumatoid patients who had undergone forefoot reconstruction four years previously. Patients with valgus hindfoot deformities tended to have high forefoot pressures whereas those with a normal hindfoot recorded normal pressures on the dynamic pedobarograph. All patients with residual forefoot pain recorded abnormal forefoot pressures. We believe that orthotic control of hindfoot deformities should be considered for those patients who require forefoot surgery as a combination of surgical and orthotic management may offer the best chance of success.

We report a prospective study of the causes and treatment of 26 long-standing neuropathic ulcers of the foot in 21 patients. The most important causal factor, well illustrated by pressure studies, was the presence of a dynamic or static deformity leading to local areas of peak pressure on insensitive skin. All but one of the 26 ulcers had healed after an average of 10 weeks of treatment in a light, skin-tight plaster cast, with the prohibition of weight-bearing. Recurrent ulceration was prevented in all but one foot by early operation to correct the causative deformity; this was performed after the ulcer had healed and before allowing weight-bearing on the limb. Pressure studies after operation confirmed that pressure points had been relieved.

Static and dynamic measurements of foot pressure have been carried out on three groups of subjects: diabetic patients with neuropathy (with and without a history of ulceration), diabetic patients with no neuropathy, and normal subjects as controls. In many cases both techniques of measurement detected areas of abnormally high pressure under the foot, but in some cases a particularly high-pressure spot was detected on only one of the tests and sometimes both methods were needed to reveal all the areas of the foot which might be considered to be at risk. The dynamic measurements tended to show multiple areas of high pressure better than the static measurements. Our results indicate the importance of making both types of measurement when seeking to devise suitable means of protecting the foot from ulceration.