Do clinical outcomes correlate with bone density after open reduction and internal fixation of tibial plateau fractures.

ABSTRACT

INTRODUCTION: The operative management of tibial plateau fractures in elderly patients has historically led to inconsistent results, and these clinical outcomes were thought to be associated with poor bone quality often in elderly patients. The goal of this study was to investigate the relationship between bone density and subjective clinical outcome scores after open reduction and internal fixation of tibial plateau fractures. MATERIALS AND METHODS: This is a retrospective cohort study from a single-surgeon conducted at an Academic, Level 1 Trauma Center. A preoperative computed tomography (CT) scan was obtained for all patients. Bone density of the distal femur was quantified with Hounsfield units (HU) as measured on axial CT scans. Inter-rater reliability of HU measurements was assessed using interclass correlation coefficients. Regression models controlling for age were used to identify relationships between bone density (HU) and the following variables articular subsidence and 1-year subjective clinical outcomes scores [Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS), and Short-Form-36 (SF-36) physical and mental component scores (PCS, MCS)]. RESULTS: Sixty-one patients with a mean age of 59.3 years (range 27-85 years) and a minimum of 12 months of clinical follow-up were included in the study. The majority of the fractures (32 of 61) were classified as Schatzker II tibial plateau fractures, and there were 13 Schatzker V fractures, 11 Schatzker VI fractures, 2 Schatzker IV fractures and 1 Schatzker 1 fracture. HU measurements demonstrated an almost perfect inter-observer reliability (ICC = 0.97). Age was negatively correlated with HU measurements (r = -0.51, p < 0.001), and using a geriatric cut-off of 65 years of age, the geriatric group had a lower mean HU compared to the non-geriatric group (78.2 versus 114.8, p = 0.018). There was no significant relationship between bone quality, as assessed by distal femoral HU, and any subjective clinical outcome score. CONCLUSIONS: Inferior bone mineral density alone does not appear to affect clinical outcomes 1 year postoperatively when bone grafting is used to restore osseous voids. Poor bone quality should not be used as an indication for non-operative management of tibial plateau fractures.