Bone mineral assessments in the calcaneus after anterior cruciate ligamentinjury - An investigation of 92 male patients before and two years after reconstruction or revision surgery

The aim of this study was to assess the Bone Mineral Areal mass (BMA) in th e calcaneus of male patients with unilateral anterior cruciate ligament (AC L) injury before and after reconstruction and to assess whether the BMA rat io or the BMA of the injured and uninjured side correlated with the level o f activity, functional performance or the time period between the injury an d the reconstruction. Ninety-two male patients with unilateral ACL injury were included in the st udy. The BMA was analysed immediately prior to surgery: a median of 11 (2-1 92) months after the injury in 30 patients aged 26 (15-41) years scheduled for primary ACL reconstruction (Group A). Forty-nine patients aged 29 (18-4 9) years had their BMA analysed a median of 24 (23-29) months after the pri mary ACL reconstruction (Group B). Thirteen patients aged 27 (21-39) years had their BMA analysed a median of 24 (20-45) months after ACL revision sur gery (Group C). The median BMA ratio (injured side/uninjured side) was 96 (88-105)% in Grou p A, 96 (86-118)% in Group B and 95 (83-111)% in Group C. In all three grou ps, the median BMA value in the calcaneus was significantly lower on the in jured side compared with the uninjured side (P=0.001, P=0.0003, P=0.01 in G roups A, B and C, respectively). The time period between the injury and the reconstruction neither correlated with the BMA ratio nor the BMA of the in jured or the uninjured side in Group A. The level of activity as measured b y the Tegner activity level and the functional performance as measured by t he one-leg-hop quotient did not correlate with the BMA ratio in any of the groups. In the 49 patients with a primary ACL reconstruction (Group B), the post-operative Tegner activity level correlated with the BMA, on both the injured and uninjured side (P=0.0003, P=0.0005, respectively), when the BMA was assessed two years after the index operation. Male patients with unilateral ACL injury had a significantly lower BMA in t he calcaneus on the injured side compared with the uninjured side before pr imary reconstruction, two years after primary reconstruction and two years after revision surgery. The time period between the injury (sic).