Inferior Subluxation of the Fibular Head Following Tibial Lengthening with a Unilateral External Fixator

• Published in: Journal of bone and joint surgery. American volume Vol. 86; no. 7; pp. 1491 - 1496
• Main Authors: Hatzokos, Ippokratis, Drakou, Androniki, Christodoulou, Anastasios, Terzidis, Ioannis, Pournaras, John
• Format: Journal Article
• Language: English
• Published: Boston, MA Copyright by The Journal of Bone and Joint Surgery, Incorporated 01.07.2004; Journal of Bone and Joint Surgery Incorporated; Journal of Bone and Joint Surgery AMERICAN VOLUME
• Edition: American volume
• Subjects: Adolescent; Adult; Biological and medical sciences; Bone Lengthening - adverse effects; Child; Diseases of the osteoarticular system; Equipment Design; External Fixators; Female; Fibula; Humans; Knee Dislocation - diagnostic imaging; Knee Dislocation - etiology; Male; Medical sciences; Radiography; Tibia - surgery; Fixator; Fibula; Head; Luxation; Tibia; Orthopedics; Rheumatology; External; Unilateral
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-200407000-00019

BackgroundInferior subluxation of the proximal part of the fibula has been reported to occur with distraction osteogenesis of the tibia; however, the clinical sequelae of this subluxation are unknown. The purpose of this study was to evaluate inferior subluxation of the proximal part of the fibula and its possible clinical implications in patients who had undergone tibial lengthening by distraction osteogenesis with use of a unilateral external fixator.MethodsThirty tibiae in seventeen patients with a variety of conditions underwent tibial lengthening by distraction osteogenesis with use of a unilateral external fixator and were followed clinically and radiographically for a mean of two years and ten months (range, two to four years). Ten patients were female and seven were male. Their mean age at the time of the surgery was seventeen years (range, eight to twenty-five years). The mean tibial lengthening was 8.1 cm (range, 3.5 to 13 cm).ResultsAn inferior shift of the fibular head in relation to the tibia was evident in all cases. The shift, which ranged from 0.4 to 3.3 cm, was proportionally related to the amount of tibial lengthening. This type of subluxation is probably attributable to the tension that is exerted by the intact interosseous membrane during the distraction as well as to the tension of the regenerated bone of the fibula and the fact that the fibula itself is not fixed or directly lengthened by the external fixator.ConclusionsIt appears that inferior subluxation of the fibula is a common phenomenon in patients undergoing tibial lengthening by distraction osteogenesis with use of a unilateral external fixator. However, no clinical symptoms or findings related to the inferior subluxation of the fibula were found in our series.