(P 280) SURGICAL OUTCOMES OF PELVIC CHONDROSARCOMA WITH A FOCUS ON WALKING ABILITY

Objective: Surgical treatment is the mainstay for pelvic chondrosarcoma. Due to the extent of the invasion and complications, postoperative walking ability is expected to deteriorate. This study aimed to identify factors associated with walking ability after surgery for pelvic chondrosarcoma.

Methods: Among 102 cases of primary malignant pelvic bone tumors initially treated at our hospital from 1984 to 2020, 12 cases of chondrosarcoma with wide tumor resection and follow-up for more than one year were included. There were 9 males, with a median age of 52 years, a median tumor size of 11 cm, and 11 cases of high-grade malignancy (Table 1). Walking ability was classified into five categories: wheelchair-bound, walker use, crutch use, cane use, and independent walking. Ambulatory status was defined as walker use or better. Walking ability was assessed at six months postoperatively, one year postoperatively, and at the final follow-up. Surgical outcomes and factors related to walking ability were investigated.

Results: Preoperative ureteral stents were placed in 9 cases, and arterial embolization was performed in 2 cases. The average operation time was 816 minutes, the average blood loss was 3644 ml, and navigation was used in 3 cases. Resection areas included P23 in 4 cases, P1234 in 3 cases, P1, P3, and P123 in 1 case each, external hemipelvectomy (EH) in 2 cases, and femoral head resection in 2 cases. All cases had R0 resection margins. Reconstruction included hip transposition in 9 cases and heat-treated autograft reconstruction in 1 case, with pelvic external fixation performed in 6 cases. Intraoperative urethral injury occurred in 2 cases, and the superior and inferior gluteal arteries required ligation in 2 and 1 cases, respectively. The obturator nerve was sacrificed in 7 cases, and the L5 nerve root in 2 cases. Postoperative complications occurred in 11 cases, including deep infection in 7 cases, superficial infection in 10 cases, and skin necrosis in 6 cases (some cases had multiple complications). The overall 5-year survival rate was 90%. The number of cases achieving walking ability with walker assistance or better was 2 at 6 months postoperatively, 3 at 1 year postoperatively, and 5 at the final follow-up. Cases with larger tumors had a significantly higher incidence of skin necrosis (p = .03). Postoperative walking ability at 6 months, 1 year, and the final follow-up did not reveal any significant associated factors (Table 2, 3, 4). However, at 1-year post-surgery, resections involving P1 tended to be associated with poorer walking ability improvement (p = 0.08). Generally, there was little improvement in walking ability beyond 1-year post-surgery, though some cases showed further improvement. Excluding EH cases, patients requiring resections involving P2 had significantly worse walking ability at 1 year post-surgery (p = 0.02).

Conclusion: In the early postoperative period after surgery for pelvic chondrosarcoma, walking ability significantly deteriorates, but the number of cases able to walk increases over time. It is crucial to provide sufficient informed consent for patient groups expected to experience impaired walking function.