BONE BRUISING OF THE KNEE: A PROSPECTIVE RANDOMISED STUDY TO ELUCIDATE THE NATURAL HISTORY OF MRI-DIAGNOSED BONE BRUISING

Abstract

Aim To study the natural history of bone bruising of the knee and to identify the effect of weight bearing and associated internal derangement (ID) on clinico-radiololgical progress of bone bruising of the knee.

Method Patients with an acute knee injury were prospectively assessed by clinical and MRI examination within 48 hours of injury. Patients with fracture, osteoarthrosis, bleeding disorder and previous injury or surgery to the injured knee were excluded. Internal derangement (ID) of the knee joint was identified. Patients with bone bruising (study group) were randomised into weight bearing and non weight bearing groups and followed up for clinical and MRI examination at six weeks, three months, six months and twelve months. At follow up, bone bruising on MRI was classified as Progressive, Static, Resolving or Resolved. Patients without bone bruising (control group) were similarly followed up for clinical examination. This is an ongoing study

Results Twenty-eight patients were available for the follow up. There were 8 patients in the control group and 10 patients each in the weight bearing and non-weight bearing group. Eleven patients had associated internal derangement of the knee joint.

Clinical improvement was better in the control group compared to the study group. Patients with isolated bone bruising were doing better than those with associated ID.

Radiololgically there was a tendency for the bone bruise (BB) to progress in the first six weeks but the majority started resolving by three months time. All isolated BB were resolved by six months but there was delayed resolution of BB associated with internal derangement.

Weight bearing status did not influence clinical or radiological course of bone bruising.

Conclusion Weight bearing does not alter the course of the bone bruising. Internal derangement associated with bone bruising delayed radiological resolution and clinical improvement of the patient.