Functional outcomes and complications of tibial lengthening using unilateral external fixation and then plating. A prospective case series

Abstract

Introduction: and Importance: The purpose of this study was to assess the functional outcomes and complications of tibial lengthening using unilateral external fixation and then plating.

Material and methods: This was a prospective case series study that enrolled people of short stature or leg length discrepancy of more than 3 cm from January 2019 to January 2021. A total of 11 patients (one male and 10 females) were recruited for the study, including seven short statures and four patients with leg length discrepancies. The external fixaters in this study were Muller's frame or Nhan's frame.

Results: The average age of patients at the time of surgery was 25.89 years (range: 13-41 years). The study included 18 tibias that were lengthened and then plated. Average tibial lengthening was 6.89 ± 1.25 cm (21.87 ± 6.59%). The functional result was excellent in seven patients and good in four patients. Pin-track infection occurred in three tibias. There was one case of superficial infection. 12 legs (66.7%) developed ankle equinus after removing the external fixator. Four legs with severe equinus deformity were treated with percutaneous tendo-Achilles lengthening. Valgus deviation occurred in eight tibias. Peroneal nerve neuropraxia occurred in two legs during distraction. Distal migration of the fibula head occurred in four legs.

Conclusion: Our study suggested that tibial lengthening using Nhan's external fixater or Muller frame then plating was safe and effective provided complications were looked for and kept in check. Equinus contracture, pin-site infection, and valgus alignment were the most common complications.

Level of evidence: Level IV, prospective case series study.

Keywords: Distraction; External fixater; Lengthening then plating; Osteogenesis; Plate; Vietnam.

Fig. 1

The external fixators were used in the study. Note: A) Nhan's external fixator after assembly; B) Vertical bar with six faces numbered 1-2-3-4-5-6 in the direction of stretching. C) Muller external fixator after assembly.

Fig. 2

A 7 cm right tibial lengthening using Nhan's external fixator then locking plating. Note: A,B,C) Clinical and X-rays pre-operative of 13 year-old female patients showed a 7 cm leg-length discrepancy; D,E) post-operative, F) X-rays 1.5 months post-operative; G,H) 3 months post-operative; I,J,K) Plating and removal of external fixater; L,M) 2 months post-operative of plating and removal of frame; N,O,P,Q) Clinical and X-rays 1 years post-operative (after plating removal of frame).

Fig. 3

A 7 cm bilateral tibial lengthening using Muller external fixator then locking plating. Note: A) Clinical pre-operative of 24 year-old female patients (Height: 1.47 m); B,C,D,E) X-rays and clinical post-operative, F,G) X-rays and clinical 2.5 months post-operative (finished distraction); H, I, J, K, L) Clinical and X-rays 14 months post-operative (after plating removal of frame).