Screw Distraction Technique For Gaining Fibular Length

Abstract

Category: Trauma Introduction/Purpose: A shortened fibula may be caused by several conditions like tumors, premature closure of the growth plate and most frequently, malunion. Biomechanically a shortened fibula causes a lateral shift of the talus, widening of the ankle mortise, decreased tibiotalar contact area and eventually could lead to osteoarthritis. Even in a posttraumatic scenario, with moderate or severe osteoarthritis, fibular lengthening has shown to be beneficial in terms of pain reduction and improved function.Several osteotomies have been described with their advantages and disadvantages in terms of technical difficulty, need for bone graft and the ability to correct length and rotation.We present an easy and reproducible surgical technique on a case, that allow restoring length and rotation independently and it does not require complex distractor devices. Methods: Case report: A 34 year old female patient who presented 8 months status post initial open reduction internal fixation (ORIF). She developed a fibular nonunion, broken distal fixation with a shortened fibula and non-anatomic mortise and presented for revision surgery.Surgical technique: The fibula is exposed in standard fashion. A fully-threaded cortical screw is placed across the tibia, distal to the fibula fracture and parallel to the plafond. Next, a second screw is placed into the fibula bicortically from anterior to posterior and approximately 12 mm distal to the tibial screw. A toothed laminar spreader is then placed in-between the screws and distracted resulting in a lengthening of the fibula. A 2 mm Kirschner wire is placed to hold reduction once fibular length is restored and ORIF continues in standard fashion. Results: The technique we present has several advantages. The technique is straightforward, easy to reproduce, and cost effective. Since the anchoring points used for distraction are not both in the fibula, rotation is not implicitly locked in as in the case when both anchoring points are in the fibula, allowing for independent and progressive adjustment of both length and rotation. There is also less risk of proximal migration of the fibular head as no force is applied directly to the proximal fibula. There is also less risk of proximal migration of the fibular head as no force is applied directly to the proximal fibula. Conclusion: Fibular lengthening can achieve improved function, pain relief and decrease the risk of osteoarthritis in selected patients. Several techniques with different degrees of difficulty have been described to treat this condition, but most are not versatile enough in correcting the length and rotation independently. The technique that we present has the advantage of correcting the length and rotation as needed, without requiring complex devices.