SLR - August 2014 - Sari Goldman

A New Look at the Hawkins Classification for Talar Neck Fractures: Which Features of Injury and Treatment Are Predictive of Osteonecrosis?

Reference: Vallier HA, Reichard SG, Boyd AJ, Moore TA. A New Look at the Hawkins Classification for Talar Neck Fractures: Which Fractures of Injury and Treatment Are Predictive of Osteonecrosis? J Bone Joint Surg Am. 2014 96(3): 192-97.

Scientific Literature Review

Reviewed By: Sari Goldman, DPM 
Residency Program: Montefiore Medical Center, Bronx NY

Podiatric Relevance: Since osteonecrosis is a common complication associated with talar neck fractures, the Hawkins classification has been historically utilized to evaluate the risk of osteonecrosis associated with the different fracture patterns. This article portrays an investigation of the timing of talar fracture reduction events and reassesses the effectiveness of the Hawkins classification scheme used for talar neck fractures.

Methods: The records of 80 patients with 81 talar neck and/or body fractures were retrospectively reviewed. There were 40 male and 40 female patients with a mean age of 36.7 years. All fractures were treated surgically by five orthopaedic traumatologists. Osteonecrosis was defined on ankle and foot radiographs as increased radiographic density of the talar dome, relative to the adjacent osseous structures.

Results: After a mean of 30 months of follow up, 16/65 fractures developed osteonecrosis but 7/16 revascularized without collapse. Hawkins Type I and IIA never displayed osteonecrosis (fractures without subtalar joint subluxation). Twenty-five percent of Hawkins type IIB fractures developed osteonecrosis and 41 percent of Hawkins type III. Osteonecrosis also occurred after 30 percent of open fractures and only 21 percent of closed fractures (not a statistically significant difference). Thirty-five patients had delayed ORIF (mean was 10.6 days), including 10 Hawkins type IIB and 10 with Hawkins type III fractures, after initial closed reduction. Only one out of these 20 patients developed osteonecrosis. Additionally, 35 patients developed post traumatic arthritis (83 percent were associated with a talar body fracture and 59 percent of Hawkins type III fractures).

Conclusions: Separating out the Hawkins type II fractures into type IIA and IIB was helpful in predicting the likelihood of osteonecrosis. The difference is whether or not the subtalar joint was subluxed or dislocated. In this study, osteonecrosis never occurred when the subtalar joint was not dislocated. When osteonecrosis did develop, it often revascularized without talar dome collapse. Finally, delaying ORIF did not increase the risk of developing osteonecrosis in this study. 

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