LIMB-SALVAGE SURGERY AFTER UNPLANNED SURGERY FOR EXTREMITY BONE SARCOMAS: 30-YEAR EXPERIENCE AT A TERTIARY REFERRAL CENTRE

Bone sarcomas are rare and can mimic other entities, such as benign lesions or usual fractures. Subsequently, bone sarcomas can occasionally be operated on without recognition or under incorrect diagnosis (unplanned surgery). The tumor cells may be spread into the surrounding tissue after unplanned surgeries, which can render limb-salvage surgery challenging and can be associated with a worse outcome. In this study, we investigated the following questions: 1) what is the pattern of unplanned surgeries for bone sarcoma, 2) who received limb-salvage surgery, and 3) what are the oncologic outcomes? This was a single-center retrospective study. All patients from 1993 to 2023 presenting with extremity bone sarcoma after unplanned surgery and undergoing surgical treatment in our institution were included. The demographics and details of unplanned surgeries were analyzed. The local recurrence and disease-specific survival were compared between the limb-salvage group and the amputation group. In total, 32 patients were included, and 50% (16/32) received limb-salvage surgery. Median follow-up was 65 months (IQR, 11 – 162). Of these patients, 41% (13/32) had chondrosarcoma, 25% (8/32) had osteosarcoma, and the remaining had other bone sarcomas. They were initially diagnosed to be benign lesions in 38% (12/32), usual fractures in 31% (10/32), metastatic carcinoma in 16% (5/32), and osteoarthritis in 16% (5/32). The location was femur in 69% (22/32), tibia in 9% (3/32), hand or foot in 9% (3/32) and other in 13% (4/32). The backgrounds of the limb-salvage group and amputation group significantly differed in age (median 47 (IQR, 41–56) versus 62 (IQR, 44–69) years old, p=0.048), tumor size (median 7 cm (IQR, 6–10) versus 14 cm (IQR, 11–20), p=0.006), and type of unplanned surgery (Table 1, p=0.049). Of the 7 intramedullary nail cases, limb-salvage surgeries were only performed on the femurs but not the humerus and tibia. Between the limb-salvage and amputation groups, the 5-year local recurrence-free survival was similar among the groups (93% versus 89%, p=0.81). The 5-year disease-specific survival was better in the limb-salvage group (93% versus 48%, p=0.002) without controlling for age and tumor size. Incorrect diagnoses as benign tumors were the most common cause for unplanned surgery in patients with extremity bone sarcomas. Unplanned surgery of larger tumors and more contaminating procedures, such as arthroplasty and intramedullary nails (especially in the humerus and tibia), may render limb-salvage surgery unfeasible. Limb-salvage surgery was not associated with a higher local recurrence rate with our cohort size and may be considered whenever possible, especially for patients after plate/screw fixation, curettage/partial resection, and femoral intramedullary nail. For any figures or tables, please contact the authors directly.