The safety of direct primary excision of low-grade chondral lesions based on radiological diagnosis alone.

: The safety of treating low-grade chondral tumours by primary surgery without a pre- operative diagnostic needle biopsy was assessed by looking at the concordance between radiological and histological diagnoses. A retrospective review of the departmental histopathology registry from 2005 to 2009 was performed to identify cases of intramedullary chondral lesions in the appendicular skeleton. Cases with a pre-operative needle biopsy and with recurrence were excluded. Correlation between radiological and histological diagnosis was investigated with kappa analysis. Of 53 patients, bone expansion was seen in 18.4%, endosteal scalloping in 42.9% and extraosseous extension in 143%. Concordance was 100% between the radiological and histological diagnoses (Kappa score = 1.0). If a radiological diagnosis of an enchondroma or low-grade chondrosarcoma is made, then direct surgical treatment without needle biopsy is safe. A biopsy should be considered if any atypical radiological features suggesting a high-grade chondrosarcoma exist. This increases the certainty of diagnosis and allows planning of surgical treatment.