SLR - April 2014 - Kelly M. Pirozzi
Reference: Vallier HA, Reichard SG, Boyd AJ, Moore TA. A New Look at the Hawkins Classification for Talar Neck Fractures: Which Features of Injury and Treatment Are Predictive of Osteonecrosis?. J Bone Joint Surg Am. 96A:192-197, 2014
Scientific Literature Review
Reviewed By: Kelly M. Pirozzi, DPM
Residency Program: Temple University Hospital; Philadelphia, PA
Podiatric Relevance: This study aims to better correlate the risk factors for development of osteonecrosis in talar fractures. The Hawkins classification is often used to classify these injuries as well as their associated risk of osteonecrosis. However, the more clinically relevant issue is whether or not delaying treatment in these patients has any implications on the vascularity of the talus. This study demonstrated that the type of injury and whether or not there are associated joint displacements had a greater correlation with osteonecrosis rather than time of ORIF. The podiatric relevance of this article is that closed talar fracture without neurovascular compromise may undergo delayed fixation due to soft tissue edema without any additional concern for increased osteonecrosis.
Methods: This study was conducted at a level-one trauma center over a ten year period and eighty one talar fractures (eight patients) were reviewed. There were forty male and forty female patients with a mean age of 36.7 years included in this study. Based on the Orthopaedic Trauma Classification, there were fifty-two talar neck fractures and twenty-nine talar neck and body fractures. Hawkins classification system was then used to classify these fractures: two type 1, forty-two type 2, thirty-two type 3, and three type 4.
All patients were surgically treated by five orthopaedic traumatologists. Patients taken urgently to the operating room included open fractures, irreducible dislocations, and fractures up to the discretion of the surgeon. Timing of the definitive fixation was up to the discretion of the treating surgeon. Clinical outcome variables included osteonecrosis and post traumatic arthritis, as well as the need for secondary reconstructive procedures. Possible predictive variables included open versus closed fractures, fracture pattern, and the presence of a talar body or medial malleolar fracture.
Results: Forty-six fractures were treated with urgent ORIF at a mean of 10.1 hours. Twenty-two of these were open fractures, fifteen were irreducible, and nine were at the discretion of the surgeon. Of the fractures treated urgently, eight were Hawkins type 2A, thirteen were type 2B, twenty one type 3, and three type 4.
Sixty three patients had follow up of thirty months. Of these patients, two fractures developed nonunion, two malunions, and sixteen developed osteonecrosis. Osteonecrosis never occurred in Hawkins type 1 or 2A fractures. However, type 2B fractures developed osteonecrosis 25 percent of the time and type 3 developed osteonecrosis 41 percent of the time. Of the fractures that developed osteonecrosis, 44 percent revascularized without collapse. Thirty-five patients developed post traumatic arthritis, which included 83 percent of those with body fractures and 59 percent of type 3 injuries.
Conclusions: This study demonstrated that following talar neck fractures, osteonecrosis of the talar body is associated with the initial amount of fracture displacement and/or associated dislocations. Osteonecrosis did not occur in patients that had an intact subtalar joint. However, when necrosis does occur revascularization often occurs without collapse of talar dome. There was no correlation between delaying reduction and definitive internal fixation with associated osteonecrosis.