(P 103) EARLY OUTCOMES OF BONE PROSTHESIS COMPOSITE FOR RECONSTRUCTION IN LOWER LIMB TUMORS. A SINGLE INSTITUTION STUDY

Objective: Reconstruction after long tumor resection are challenging due to limited options available. Augmenting residual bone length with either allograft or autograft to enhance prosthesis fixation after long segment resection, provides a good option for avoiding a total bone replacement.

Methods: In order to analyse the short-term outcomes with a view to judge the efficacy of this technique, we retrospectively analyzed 20 patients operated between 2005- June 2021 at out institution for graft union, time to weight bearing and associated complications.
Patients in whom patient’s own bone was used after sterilization (Extracorporeal radiotherapy/Cryotherapy), or an allograft was used to augment fixation were included in the study. In 15 out of 20 patients, more than 50% of implant stem was in the augmented bone. Fixation with plate was done in 10 out of these 15 cases to improve the stability. In remaining 4 of 5 cases, allograft was telescoped with the host bone to improve stability.

Results: Ten patients died of disease and 1 was lost to follow up. Among the 18 constructs with known outcomes, 14 constructs were in-situ at a mean follow-up of 40 months (range: 6–116 months) while 4 underwent removal. Constructs were completely intact in 11, partially intact (during revision surgery) in 2 and in 1 patient with local recurrence who underwent amputation, stem-graft construct was retained. The overall graft survival was 88.5% at 2 years and 69% at 5 years. For constructs with ≥50% stem incorporation, the 2-year and 5-year graft survival rates were 86.2% and 61.3%, respectively. In contrast, constructs with < 50% stem incorporation demonstrated 100% survival at both 2 and 5 years (p=0.31).

Conclusion: Bone prosthesis composite is an acceptable option for reconstruction after long segment resection in lower limb.