Intraoperative physician assessment of bone: correlation to bone mineral density

This study evaluated the intraoperative physician assessment (IPA) of bone status at time of total knee arthroplasty. IPA was highly correlated with distal femur and overall bone mineral density. When IPA identifies poor bone status, formal bone health assessment is indicated.

Purpose: Intuitively, intraoperative physician assessment (IPA) would be an excellent measure of bone status gained through haptic feedback during bone preparation. However, no studies have evaluated the orthopedic surgeon's ability to do so. This study's purpose, in patients undergoing total knee arthroplasty (TKA), was to relate IPA with (1) the lowest bone mineral density (BMD) T-score at routine clinical sites; and (2) with distal femur BMD.

Methods: Seventy patients undergoing TKA by 3 surgeons received pre-operative DXA. Intraoperatively, bone quality was assessed on a 5-point scale (1 excellent to 5 poor) based on tactile feedback to preparation. Demographic data, DXA results, and IPA score between surgeons were compared by factorial ANOVA. Lowest T-score and distal femur BMD were associated with IPA using Spearman's correlation.

Results: The mean (SD) age and BMI were 65.8 (7.6) years and 31.4 (5.1) kg/m², respectively. Patient demographic data, BMD, and IPA (mean [SD] = 2.74 [1.2]) did not differ between surgeons. IPA correlated with the lowest T-score (R = 0.511) and distal femur BMD (R = 0.603-0.661). Based on the lowest T-score, no osteoporotic patients had an IPA above average, and none with normal BMD was classified as having poor bone.

Conclusions: IPA is highly correlated with local (distal femur) and overall BMD. This study supports the International Society for Clinical Densitometry position that surgeon concern regarding bone quality should lead to bone health assessment. As IPA is comparable between surgeons, it is logical this can be widely applied by experienced orthopedic surgeons. Future studies evaluating IPA at other anatomic sites are indicated.