SLR - July 2011 - Ryan Wood
Reference: Evans J, Beingessner D, Agel J, Benirschke S. Minifragment Plate Fixation of High-Energy Navicular Body Fractures. Foot and Ankle International, (May 2011) Vol. 32, No. 5: 473-484
Scientific Literature Review
Reviewed By: Ryan Wood, DPM
Residency Program: Northern Colorado Podiatric Surgical Residency
Podiatric Relevance:
Navicular fractures are seen with increasing frequency at trauma centers due to improvements in automobile safety, resulting in improved survival of patients with severe, high-energy foot injuries. The most frequently injured lesser tarsal bone is the navicular. Due to the critical role of the navicular in the medial column and the importance of the talonavicular joint, every effort should be made to reconstruct, with precision, the navicular and its surrounding joints.
Methods:
A retrospective chart review was performed on 24 patients with navicular body fractures treated with open reduction and internal fixation with minifragment plate fixation at a level one trauma center of a period of 6 years (2001-2007). The average time from injury to definitive fixation was 12 days due to the surgeon's protocol of allowing a period of soft tissue rest for swelling to stabilize. Average radiographic follow-up was 15 months. Average clinical follow-up was 16 months.
The surgical approach typically was made with a dorsomedial and/or dorsolateral skin incision, depending on which side the primary fracture was located. Adequate reduction was usually achieved with a temporary spanning external fixator, typically applied from the calcaneus to the cuneiforms. Fixation was then carried out using stainless steel mini-fragment 2.0 mm or 2.4 mm straight or T-plates. Non-weightbearing was recommended for 8 weeks.
Results:
24 patients with displaced navicular body fractures were identified that were treated with 2.0 mm, 2.4 mm, or 2.7 mm mini-fragment plates, either straight or T-plates. Mechanism of injury was MVA in 9 patients, motorcycle collision in 6 patients, fall from a height in 7 patients, and crush injury in 2 patients. According to the Sangeorzan classification, there were 8 (33%) Type II fractures and 16 (66%) Type III fractures. Multiple co-existing foot injuries were present in the majority of patients.
All fractures healed with bony union determined by plain films. No patient developed a deep infection. There was no loss of reduction. Isolated broken screws were evident in 3 patients (12.5%), with no plate breakage, and no implant failure by pullout. Four patients (17%) underwent plate removal for painful prominent hardware following fracture healing. Four patients (17%) developed radiographic arthrosis of the talonavicular joint. In all cases that developed arthrosis, the fractures had been classified as Type III. No patient underwent a fusion procedure. One patient (4%) had radiographic avascular collapse evident at 6 months and was treated with plate removal and orthotic.
Conclusions:
This study is limited due to its small sample size and short follow-up period. The results of the study are promising, however, due to the favorable rates of bony union, few cases of avascular collapse, and small number of patients with arthrosis. The surgical technique used by the authors attempts to minimize vascular insult while achieving good fixation with a minifragment plate. Minifragment fixation can be a good alternative to independent lag screws for rigid stabilization of navicular body fractures.