Computed tomographic assessment of soft tissue abnormalities following calcaneal fractures.

Computed tomographic (CT) examinations of 50 acute calcaneal fractures were compared with a further series of 77 fractures in which the date of injury preceded the CT by 6 months or more. 42 (84%) of the fractures in the acute group and 55 (71%) in the chronic group were classified as intra-articular and they form the basis of this study. The alteration in the position of the peroneal tendons in the two groups was similar, with a 5% or less difference in each category. In the acute group the peroneal tendons were normally located in 40.4% of the cases, entrapped by bone in 11.9%, subluxed in 33.3% and dislocated in 14.2%. Structural abnormalities of the peroneal tendons and surrounding soft tissues were identified in 52.4% of the acute group and in 61.1% of the chronic group. The incidence of partial rupture of the peroneal tendons in the chronic group was approximately one third that in the acute group, but the low incidence of complete tendon rupture remained unchanged. The inference from these observations is that, in the majority of cases, partial peroneal tendon rupture is reversible, whereas complete rupture is not. Seven fractures were common to both series and from this limited group the identification of haemorrhage around the peroneal tendons in the acute phase was shown not to be related to the subsequent development of chronic stenosing tenosynovitis. Various abnormalities of the medial tendons of the hindfoot were identified in 17% of the acute group and in 18% of the chronic group. Following calcaneal fracture, CT in both the immediate post-fracture period and in the late phase can be used to detect and classify the soft tissue changes. The limitations of comparing the two groups in this study are discussed.