Bone quality assessment for total hip arthroplasty with intraoperative trabecular torque measurements.
BACKGROUND
In cases of poor bone quality, intraoperative torque measurement might be an alternative to preoperative dual-energy X-ray absorptiometry (DXA) to assess bone quality in total hip arthroplasty (THA).


METHODS
Trabecular peak torque measurement was applied in 14 paired fresh frozen human femurs. Here, a 6.5 × 23 mm wingblade was inserted into the proximal femur without harming the lateral cortical bone. Further tests of the proximal femur also evaluated bone strength (DXA, micro-computed tomography (μCT), monoaxial compression test), and the results were compared to the trabecular torque measurement. Student's t-test was used to compare the values of the groups. Pearson product-moment was applied to correlate the values of the peak torque measurement with the bone strength measured by DXA, μCT, and monoaxial compression test.


RESULTS
In the femoral head, the mean trabecular peak torque was 4.38 ± 1.86 Nm. These values showed a strong correlation with the values of the DXA, the μCT, and the biomechanical load test (Pearson's product-moment: DXA: 0.86, μCT-BMD: 0.80, load test: 0.85). Furthermore, the torque measurement showed a more pronounced correlation with the biomechanical load test compared to the DXA.


CONCLUSIONS
The use of this method provides highly diagnostic information about bone quality. Since the approach was adjusted for THA, no harm of the lateral bone stock will result from this measurement during surgery. The results of this initial study employing small sample sizes indicate that this new method is as sensitive as DXA in predicting bone quality and may function as an intraoperative alternative to DXA in THA. Nevertheless, before this method will turn into clinical use, more research and clinical trials are necessary.
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. Matthias.klotz@med.uni-heidelberg.de.
Matthias C M
MC
Klotz
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. Nicholas.beckmann@med.uni-heidelberg.de.
Nicholas A
NA
Beckmann
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. rudi.bitsch@med.uni-heidelberg.de.
Rudi G
RG
Bitsch
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. elisabeth.seebach@med.uni-heidelberg.de.
Elisabeth
E
Seebach
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. tobias.reiner@med.uni-heidelberg.de.
Tobias
T
Reiner
Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstraße 200a, 69118, Heidelberg, Germany. sebastian.jaeger@med.uni-heidelberg.de.
Sebastian
S
Jäger
D015502:Absorptiometry, Photon; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015519:Bone Density; D005270:Femur Head / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D007432:Intraoperative Period; D019415:Torque; D016474:Weight-Bearing; D055114:X-Ray Microtomography