Incidence of radius shortening following intramedullary nail fixation for gunshot fractures: a retrospective radiological audit

ABSTRACT BACKGROUND: Intramedullary nail fixation is an option to manage highly comminuted fractures of the radius shaft resulting from gunshot wounds. However, complications including nail migration and malunion are well documented. We have noticed some patients presenting to our clinic with radiological shortening following nail fixation. This may result in chronic pain, reduced pronation and supination, poor grip strength and early onset arthrosis. This study aimed to quantify the incidence of radiological shortening following fixation of isolated gunshot wound (GSW) fractures of the radius with an intramedullary nail. Our secondary objectives were to identify if length of the zone of comminution and anatomical location of the fractures were risk factors for shortening, and to assess whether shortening was a result of surgical error, or whether shortening occurred over time. METHODS: We performed a retrospective review of all (n = 40) isolated radius nails performed between January 2012 and January 2019. Two doctors assessed the latest anterior-posterior forearm X-ray of every patient, using the rule of perpendiculars to calculate ulnar variance (UV). Shortening was defined as a UV > 5.0 mm. If the radius was deemed shortened by consensus, then the immediate postoperative X-ray was also assessed to gauge when shortening occurred. Anatomical location in thirds and length of comminution (mm) were also assessed. RESULTS: Forty patients with a mean age of 32 years (range 15-59) were included. Twelve patients' radiuses were assessed as radiologically short. All 12 were deemed to have been fixed short. One case shortened further over time. We found the incidence of shortening being dependent on the fracture location (p = 0.03), with the fractures occurring in the middle third of the arm shortening more. The measured zone of comminution between the shortened and non-shortened groups was not found to be statistically significant (p = 0.55). CONCLUSION: The radius nail remains useful to manage comminuted radius shaft fractures following GSW. Meticulous technique is needed to avoid radiological shortening, seen in 30% of our series. This can lead to chronic pain, reduced grip strength and early onset arthrosis. We found no evidence that shortening develops over time. We found that the incidence of shortening is dependent on fracture position but did not And any causative relationship between length of the zone of fracture comminution and shortening. Level of evidence: Level 4 Keywords: radial nail, shortening, gunshot