Iatrogenic Fracture Gapping During Fixation of Jones Fractures

Abstract

Category: Trauma Introduction/Purpose: Surgical fixation of Jones fractures is often recommended to facilitate recovery and achieve union. Iatrogenic fracture displacement during intramedullary screw fixation is a commonly encountered technical issue. This may be related to fracture location in relation to the surrounding ligamentous attachments, namely the robust intermetatarsal ligaments found at the proximal articulation of the 4th and 5th metatarsals. This study examines the relationship between fracture line and its location in regards to the surrounding ligamentous structures and its effect on Jones fracture displacement, reduction and fixation in a cadaveric model. Methods: Eighteen fresh-frozen cadaveric feet were dissected with preservation of all ligamentous attachments. Given the similar anatomic distal extent of the dorsal and plantar intermetatarsal ligaments on the 5th metatarsal, measurements were obtained detailing the anatomic position of the dorsal intermetatarsal ligament (DIL) only. The specimens were divided into two groups with modelled fractures created at the 4th & 5th metatarsal articulation proximal to the distal extent of the DIL (Group 1) or just distal to the DIL (Group 2). Fractures were fixed in standard fashion with serial fluoroscopic images obtained to study fracture gapping and rotation. Results: There was approximately 5 mm of fracture gapping created iatrogenically during tapping with no statistically significant differences between Group 1 and Group 2 (4.53 mm versus 5.25 mm, p=0.5430). The distal aspect of the DIL was anatomically located 2.77 mm (Range 1.58 mm – 4.46 mm) distal to the 4th & 5th metatarsal articulation. Conclusion: Considerable iatrogenic fracture gapping occurs during intramedullary screw fixation of Jones fractures in a cadaveric model regardless of fracture location in relation to the intermetatarsal ligamentous attachments. Intraoperative displacement may be related to iatrogenic distraction caused by canal tapping when utilizing a common surgical method. Specific techniques may be required to maintain anatomic alignment during tapping and screw fixation to prevent iatrogenic displacement.