Osseous tumors of the foot, ankle, and lower leg: a cross-sectional observational study analysing 288 cases.

Background: Osseous tumors of the foot and ankle are rarely encountered in general orthopaedic practice and represent only 3 % of osseous neoplasms. It can be difficult to distinguish between benign and malignant lesions, leading to misdiagnosis. Delays in diagnosis are the main cause of litigation in sarcoma of the extremities. Poor understanding of how sarcomas present in this region can lead to inappropriate initial procedures, limiting options for limb salvage and increasing rates of local recurrence. Our aim is to improve understanding of these rare tumors to reduce misdiagnosis and decrease the occurrence of inappropriate or unwarranted procedures.

Methods: We retrospectively analysed a prospectively maintained database of 288 new referrals to the West of Scotland regional musculoskeletal oncology service for osseous lesions of the foot, ankle and lower leg over a 10-year period. An analysis of patient demographics, presentation, anatomical location, diagnosis, classification, management and outcomes was performed.

Results: Of all new referrals, 52.4 % were diagnosed with primary benign osseous tumors, 8.7 % with primary malignant osseous tumors, 9.7 % with metastatic osseous lesions, and 29.2 % pseudotumors. The most common primary benign tumor in our population was osteoid osteoma (18.5 %), primary malignant tumor was osteosarcoma (32 %) and metastatic osseous lesions were from small cell lung cancer primary (14.3 %). In the foot and ankle, malignant bone tumors most commonly presented in the distal tibia and fibula (20 %). Rest pain was the most common symptom at presentation in all groups, followed by swelling. The average duration of symptoms was 5 months for malignant lesions before primary referral.

Conclusion: Bone tumors in the foot and ankle remain a diagnostic challenge. We hope to have increased understanding of these rare lesions and have recommended a management protocol in order to reduce the number of inappropriate procedures performed, optimising clinical outcomes and reducing the cost of litigation to healthcare services.

Level of evidence: Level III- Cross-sectional observational study.