The appearance of the pre-Achilles fat pad after endoscopic calcaneoplasty.

PURPOSE: To evaluate whether the imaging features of the retrocalcaneal recess normalize on a conventional radiograph after surgery for retrocalcaneal bursitis and evaluate whether it can be reused if complaints reoccur.

METHODS: Patients who underwent an endoscopic calcaneoplasty at least 2 years before were eligible for inclusion. A lateral conventional radiograph of the surgically treated hindfoot was made to assess the retrocalcaneal recess and pre-Achilles fat pad; images were analysed, clinical complaints were registered and evaluated. Radiographs were evaluated by two experienced observers (one orthopaedic surgeon one musculoskeletal specialized radiologist), these scored the images either as "normal" (no obliteration of retrocalcaneal recess and pre-Achilles fat) or as "abnormal".

RESULTS: Thirty patients (34 heels: 28 asymptomatic and 6 recurrent complaints) were included in this study. Observer one rated 12 images as "normal" (2 symptomatic heels and 10 asymptomatic), 22 "abnormal". Observer two rated 9 "normal" (1 symptomatic heels and 8 asymptomatic), 25 "abnormal". No correlation between the radiographic appearance and complaints (n.s.) was found. Cohen's kappa for interobserver agreement was low (0.11 n.s.).

CONCLUSION: The appearance of the retrocalcaneal recess on a lateral radiograph cannot be used as a reliable diagnostic criterion for retrocalcaneal bursitis in patients who previously underwent endoscopic calcaneoplasty. This study clinical relevance is based upon the conclusion that a lateral radiograph cannot be used after endoscopic calcaneoplasty, whereas previous work reported the diagnostic value of a lateral radiograph for retrocalcaneal bursitis prior to surgery.

LEVEL OF EVIDENCE: III.