BILATERAL HUMERAL LENGTHENING IN PATIENTS WITH ACHONDROPLASIA

Abstract

Introduction: Achondroplasia is a form of rhizomelic dwarfism. Even if patients can compensate for their short arms through the mobility in their spine during the childhood, the flexibility in their spine becomes less with aging. Because of that, as they get older they experience problems in maintaining personal hygiene especially in reaching the back. In addition putting on socks and tying their own shoes might become difficult.

Methods: Inclusion criteria included any patient with a history of achondroplasia who had undergone humeral lengthening in the proximal part of the humerus (just distal to deltoid muscle insertion). Patients who had distal humeral (supracondylar) osteotomy and/or who received other than monolateral external fixator were excluded from the study. 50 humeri of 25 patients with achondroplasia were lengthened using Orthofix mono-lateral external fixator utilizing proximal humeral osteotomy. Sixteen patients were female and nine were male. Mean age was 15.4 months (range, 9.6 – 21.8). Lengthening was started at 7th day. Patients were lengthened at 1/4 turn four times a day reaching 1 mm/day. Physical therapy was performed 3 times a week. Goal of lengthening was around 10 cm or whatever length the patient could tolerate. Patients wore Sarmiento type fracture brace 4–6 weeks after the fixator was removed.

Results: Mean follow-up time from surgery was 51.5 months (range, 6 – 143 months). Mean follow-up time from removal of external fixator was 44.7 months (range, 0 – 135 months). Average external fixation time was 7.3 months. In 20 humeri it was noted that the average duration of lengthening was 4.2 months (range, 3 – 5.8 months). A mean lengthening of 9.3 cm was obtained (range, 4.3 – 12.8 cm). At latest follow-up range of motion was not compromised due to lengthening. All patients had similar ROM before and after the surgery. Complications included radial nerve palsy in 8, pin tract infection in 7, fracture through regenerate in 3, premature consolidation in 1, nonunion in 1, delayed healing in 1. Radial nerve palsy recovered without intervention in one case. In others it recovered uneventfully after successful decompression. No complications at all occurred in 30 cases.

Discussion: Fifty humeri of 25 patients with achondroplasia received successful humerus lengthening as part of extensive limb lengthening offered in our center. None of the patients had long term sequela, and all radial nerve palsies recovered. Patients were satisfied with the lengthening and found it easier to undergo through humerus lengthening compared to lower limb lengthening. After a mean follow-up time of almost 4 years, these patients returned back to their normal lives with optimum upper limb function with no hindrance in maintaining personal hygiene, putting on socks or tying their own shoes.