Is elevated contact stress predictive of post-traumatic osteoarthritis for imprecisely reduced tibial plafond fractures?
Despite the widely held belief that residual incongruities from intra-articular fractures subject the joint to contact stresses that predispose to post-traumatic osteoarthritis (PTOA), objective evidence has been lacking. This study tested the hypothesis that a metric of elevated contact stress exposure would predict the onset of PTOA. The ankles of 10 tibial plafond fracture patients were treated initially using a spanning fixator, with subsequent screw fixation of the articular surface. Following up on an earlier report of finite element computed post-operative contact stress distributions in these patients' ankles, Kellgren-Lawrence (KL) scores were assessed from minimum 2-year follow-up radiographs to characterize the presence/severity of PTOA. At that time point, seven patients had developed PTOA (KL ≥ 2). Five different metrics of contact stress exposure were calculated, all of which exhibited excellent concordance with KL scores, ranging from 88% to 95%. When time of stress exposure was included, one metric was able to predict PTOA development (KL ≥ 2) with 100% reliability, and all metrics exhibited >94% prediction reliability. These findings, albeit in a small population, support the existence of a contact stress exposure threshold above which incongruously reduced tibial plafond fractures are highly likely to develop PTOA.
Anderson
Donald D
DD
Department of Orthopaedics and Rehabilitation, The University of Iowa, 2181 Westlawn Building, Iowa City, Iowa 52242, USA. don-anderson@uiowa.edu
Van Hofwegen
Christopher
C
Marsh
J Lawrence
JL
Brown
Thomas D
TD
D000328:Adult; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D010003:Osteoarthritis / Q000209:etiology*; D013314:Stress, Mechanical; D013978:Tibial Fractures / Q000150:complications*