Frequency, presentation and postintervention prognosis of chondroblastoma.

Objective: To evaluate the frequency of clinico-radiological presentation and the prognosis after treatment of chondroblastoma.

Design: A descriptive, observational study.

Place And Duration Of Study: The study was carried out at the Department of Orthopaedic Surgery, JPMC, Karachi over the period of 16 years, January 1986 to June 2002.

Methodology: Patients in teenage, presenting with signs and symptoms of a primary bone tumours, were included by retrospectively reviewing the tumour registry record. Detailed scrutiny of clinical record was carried out to analyze the clinico-radiological presentation and posttreatment prognosis criteria of healing was symptom-free centripetal and homogeneous ossification.

Results: Seven (1.24%) out of 563 primary bone tumour cases were chondroblastoma. The clinico-radiological presentation in the 2 out of 7 (28.57%) cases was classical, 2 simulated osteomyelitis and other 3 as chondromyxoid fibroma, aneurysmal bone cyst and giant cell tumour. Lesions were treated with curettage and bone grafting. One patient (14.28%) developed recurrence within 2 years after curettage and healed after re-curettage and bone grafting. Five out of 7 (71.42%) tumours showed good response and 2 out of 7 (28.57%) showed satisfactory response.

Conclusion: Chondroblastoma is very rare benign primary bone tumour with high local recurrence rate. The lesions confined to epiphysis of weight-bearing bone present early with symptoms of mild arthritis. Lesions in non-weight-bearing bones often present late and simulates epiphysio-metaphyseal tumours. Lesions heals with centripetal healing and need more than 2 years follow-up to achieve recurrence-free healing.