ODP105 Long-Term Bone Mineral Density Changes for Amputees Following Transcutaneous Osseointegration

BACKGROUND: Transcutaneous osseointegration (OI) is an emerging rehabilitation alternative for amputees who have difficulty with traditional socket prostheses. OI inserts a metal implant into an amputated extremity's bone, through a permanent skin stoma, allowing direct connection of a prosthetic limb to the patient's skeleton. OI implants have been shown to provide better mobility, quality of life, and address issues such as poor prosthesis fit, dermatitis, and excessive sweating. (Kunutsor et al, 2018) Direct skeletal loading facilitated by OI should improve bone health, but this question has not been evaluated over the long term. AIM: This study compared the preoperative and minimum five-year postoperative femoral neck bone mineral density (BMD) change in amputees, measured on the amputated and intact side, using dual-energy X-ray absorptiometry (DEXA). METHODS: A retrospective cohort review identified 45 lower limb amputees who had DEXA evaluation prior to transfemoral or transtibial OI implants. Six patients had follow-up DEXA performed at least five years postoperatively. These six patients’ charts were retrospectively reviewed for demographic data, FRAX specific criteria, and adverse outcomes which could have impacted time spent using the OI prosthesis. Bone density, T-scores, and Z-scores were evaluated for all BMD measurements. Comparison of mean values was assessed using Student's t-test. RESULTS: (Note: Of the 45-patient cohort, 6 patients have had a 5-year DEXA recorded at the time of abstract submission. Data collection is ongoing and is expected to be at least 15 patients at study completion) This cohort includes three males and three females, five transfemoral and one transtibial, aged between 50 and 68 (mean = 51 ± 13) years at the time of implant surgery. For the amputated limb, there was a non-significant increase from0.540 ±0.155 g/cm 2 to 0.707 ±0. 094 g/cm 2 (p = 0.105) . The Z-score increased -3. 067 ±1. 089 g/cm 2 to -1.200 ±0.540 g/cm 2 (p = 0. 024). The T-score increased from -3.933 ±1.193 g/cm 2 to -2.333 ±1.193 g/cm 2 (p = 0. 049). CONCLUSIONS: Although this is a small cohort, there were statistically significant increases of the Z-score and T-score when measured at least five years after osseointegration. Presentation: No date and time listed