974 THE JOURNAL OF BONE AND JOINT SURGERY Chondroblastoma of bone LONG-TERM RESULTS AND FUNCTIONAL OUTCOME AFTER INTRALESIONAL CURETTAGE R. Suneja, R. J. Grimer, M. Belthur, L. Jeys, S. R. Carter, R. M. Tillman, A. M. Davies From The Royal Orthopaedic Hospital Oncology Service, Birmingham, England  R. Suneja, FRCS, Specialist Registrar  R. J. Grimer, FRCS, Consultant Orthopaedic Surgeon  M. Belthur, FRCS, Specialist Registrar  L. Jeys, FRCS, Specialist Registrar  S. R. Carter, FRCS, Consultant Orthopaedic Surgeon  R. M. Tillman, FRCS, Consultant Orthopaedic Surgeon  A. M. Davies, FRCR, Consultant Radiologist The Royal Orthopaedic Hospital Oncology Service, Bristol Road South, Birmingham B31 2AP, UK. Correspondence should be sent to Mr R. J. Grimer; e-mail: rob.grimer@roh.nhs.uk ©2005 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.87B7. 16009 $2.00 J Bone Joint Surg [Br] 2005;87-B:974-8. Received 23 September 2004; Accepted after revision 8 March 2005 We undertook this retrospective study to determine the rate of recurrence and functional outcome after intralesional curettage for chondroblastoma of bone. The factors associated with aggressive behaviour of the tumour were also analysed. We reviewed 53 patients with histologically-proven chondroblastoma who were treated by intralesional curettage in our unit between 1974 and 2000. They were followed up for at least two years to a maximum of 27 years. Seven (13.2%) had a histologically-proven local recurrence. Three underwent a second intralesional curettage and had no further recurrence. Two had endoprosthetic replacement of the proximal humerus and two underwent below-knee amputation after aggressive local recurrence. One patient had the rare malignant metastatic chondroblastoma and eventually died. The mean Musculoskeletal Tumour Society functional score of the survivors was 94.2%. We conclude that meticulous intralesional curettage alone can achieve low rates of local recurrence and excellent long-term function. The term ‘benign chondroblastoma’ was coined by Jaffe and Lichtenstein 1 to describe a rare neo- plasm with a predilection for the epiphyses of long bones, thus distinguishing it from the giant- cell tumour of bone. Some features of chon- droblastoma had been recognised earlier by Kolodny, 2 who described it as a “giant cell vari- ant”, and Codman 3 who used the term “epiphy- seal chondromatous giant cell tumour”. Chon- droblastoma accounts for about 1% of all primary bone tumours and appears to arise from secondary centres of ossification. Although the most common sites are the hip, shoulder and knee, there is no part of the axial or appendicu- lar skeleton which can be excluded. 4 Most lesions are seen in adolescence during the period of active epiphyseal growth. Patients present with gradually increasing pain and local tender- ness, followed by swelling and limitation of movement of the neighbouring joint. The histopathological description of chon- droblastoma according to the World Health Organisation 5 is “a relatively benign tumour, characterised by highly cellular and relatively undifferentiated tissue, made up of rounded or polygonal chondroblast-like cells with distinct outlines and multi-nucleated giant cells of osteoclast type arranged singly or in groups. The presence of a cartilaginous intercellular matrix with areas of focal calcification is typi- cal.” About 10% to 15% of lesions are associ- ated with large, fluid-filled spaces indicative of a secondary aneurysmal bone cyst component. The recommended surgical treatment for chondroblastoma varies. Curettage, either alone or in conjunction with bone grafting or packing the cavity with polymethylmethacry- late, or coupled with cryosurgery, are among the techniques which have been described. 4 The rate of recurrence after these procedures has been reported to be between 10% to 35%. 6 Our aim in this retrospective study was to evaluate the rate of recurrence after intra- lesional curettage, to define any factors associ- ated with aggressive tumour behaviour and to evaluate the functional outcome of the patients. Patients and Methods We performed a retrospective study of 70 patients with chondroblastoma who had been referred to an orthopaedic oncology unit between 1974 and 2000. The diagnosis was based on recognised radiological and histolog- ical criteria. The age at presentation, gender, presenting symptoms, anatomical site and pre- vious treatment were noted along with the clin- ical signs, operation records and intra- and post-operative complications. Chronology