Do irradiated osteo-articular recycled tumor autografts still hold promise for biological joint reconstruction? Our experience with acetabular and proximal ulna ECRT.

BACKGROUND: Joint reconstruction following resection of malignant bone tumors is challenging in itself in spite of several options in hand. Ability to restore joint anatomy, function and mobility while achieving optimal oncological outcomes are the requirement of reconstructions today. While biological reconstructions (allograft or recycled tumor autografts) following tumor bone surgery are popular for intercalary resections not involving the joint, their use for osteo-articular reconstructions are associated with concerns over cartilage and joint health. We have used extracorporeal radiation therapy (ECRT) and re-implantation of the osteoarticular segment as a size matched recycled tumor autograft reconstruction after complex acetabular and proximal ulnar resections; owing to the lack of significantly superior reconstruction alternatives in these locations and also review the current literature on other biological/non-biological reconstruction options. QUESTIONS/PURPOSES: (1) What are the oncological, reconstruction and functional outcomes with osteo-articular reconstruction using ECRT and re-implantation of recycled tumor autograft for the acetabulum and olecranon? (2) Is there an evidence of cartilage loss, joint damage or avascular necrosis resulting from irradiation of the articular autograft?
METHODS: 19 patients with primary bone tumors underwent limb salvage surgery with en-bloc resection and reconstruction using the resected articular tumor bone after treating it with extra-corporeal irradiation of 50-60Gy. These included 16 acetabular and 3 proximal ulnar. While all patients were included for oncological assessment; minimum follow-up of 24 months was considered for final outcome assessment of function and joint status.
RESULTS: MSTS scores of the 16 acetabular reconstruction patients with minimum 2 years follow-up was 87% (26/30). Neither delayed union, non-union at osteotomy sites nor was any fractures reported in the irradiated graft. There was no local recurrence within the irradiated graft and only 1 patient required graft excision for uncontrolled infection. All 3 patients of proximal ulna reconstruction achieved healing and full range of movement of the elbow. Scores of MSTS: 100% (30/30), MEPS: 100 and DASH: zero was achieved. Two patients developed osteonecrosis of the femoral head; one requiring a joint replacement and one awaiting replacement. One patient of acetabular reconstruction has joint space narrowing on radiographs with mild clinical symptoms.
CONCLUSIONS: Extracorporeal radiotherapy and re-implantation after osteo-articular resection is an oncologically safe option offering promising outcome in our small series. The availability of size-matched graft, thus avoiding inherent problems of allograft also provides a better economic option over endoprosthesis and its associated complications in select sites. The results can deteriorate over time that may require secondary reconstructive procedures like joint replacement. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.