Abstract
The abnormal shortening of a metatarsal (MT), being congenital or aquired, may cause functional problems, on altering feet support. Besides some deformities may be aestheticaly unacceptable to some patients, particularly females. We performed a retrospective, concurrent epide-miological revision on 28 records of patients that had MT lengthening for a short metatarsal. ( 21 patients with 9 bilateral.) These were the 4th. in 22 oportunities, followed by the 1st in 7, the 3rd. in 2 and the 5th. in 1. Etiology was in 20 cases congenital shortening, 2 shortening after equinus foot surgery and 1 after osteomyelitis. Seven cases had bilateral elongation, thus making 28 cases. Age ranged from 5 years to 20 years, with a mean 10 years. The indications for surgery were pain in 10 cases and aesthetic in 18 . All. were females except one.
The Caracas group used a modified mini Anderson apparatus. After 1992 the apparatus was modified for the last 4 cases for one that could be placed only on the dorsal aspect of foot, thus allowing weight bearing. The application was performed under image intensifier placing the threaded pins perpendicularly to the MTT with transversal diafisis osteotomy, starting the elongation between 5th and 10th day at a speed of 1.5 mm weekly at a range of 0.5 mm every second day, in a period from 3 weeks to 8 weeks with a mean of 5.5 weeks. Ten had unilateral lengthening (83.33) and 2 bilateraly (16.57%) making a total of 14 metatarsal lengthenings. All were females and all had elongation fix-ation callotaxis according to DeBastiani. The cases were operated from 1987 to 1994 and with more than 6 years follow up. Age ranged from 10 to 15 years in 10 cases and 16 to 20 in 2 patients. The MTT mostly involved was the 4th. in 12 patients (85.71%), 2 bilateral (14 MTT), and the 3rd in 2 cases (14.29%), . The shortest MTT lengthened measured 3.5 cmts. Lengthening obtained ranged from 5 mm. to 22 mm, with a mean of 14.3 mm. One patient obtained 5 mm. (7.14%), another 10 mm. (7.14%), one 11 (7.14%) and 1 15mm. (7.14%), 5 (35,71%) from 16mm. To 20 mm. and other 5 (35.71%) from 21mm. to 25mm.
Complications were pseudoarthrosis in 3 cases, delayed union in 1 case and angulation in 1. These were treated by reintervention and bone graft maintaining the lengthening in 4 and in the other, 1 pseudoarthrosis the lengthening was lost.
The Buenos Aires Group with 16 lengthenings in 11 patients,used an external apparatus with 2,3 or 4 joints and threded 1 mm pins fixed in the metatarsal to length, dorsally. . In some cases the proximal pin was fixed to third cuneiform and in 6 to the the distal in the proximal phalang to aviod bending. This last mentioned method were not used afterwards because correct alignment was obtained fixing the apparatus only in the metatarsal. The corticotomy was metaphysoepyphisary lenghthening 0.5 mm daily starting the 8th day. Hospitalization time ranged 2.5 days. Minimal follow up was 2.6 years. Nine of 11 cases recovered the normal metatarsal formula. Pain disappeared in cases that had it previously but aesthetic requirements were not always completely fulfilled, special with the 1st. MT. Mean elongation length was 17 mm. Mean percentage ogf elongation was 40%. Mean duration of total treatment was 112 days, making mean healing time index of 65 days per every centimeter elongated. No axial deviation ocurred. All cases healed at callus site. The case of osteomyelitis had bone graft at operation. Complications were 3 superficial infections at pin site and 1 case of recurrent deep infection. An elongation above 50% of original length of MT should be avoided.
Local Host: British Society for Children’s Orthopaedic Surgery. Conference Theme: Congenital Deficiencies of the Lower Limb. These abstracts were prepared by A.Catterall.
