Arthroscopic removal of osteoid osteoma with gamma probe assistance in the hip joint

The aim was to present the surgical technique and clinical outcome in a series of patients treated with gamma-probe-assisted arthroscopic removal of osteoid osteoma in the hip joint.

The case series consisted of 10 patients diagnosed with osteoid osteoma of the hip, who were treated by arthroscopic nidus removal. An endoscopic gamma probe was used intraoperatively to locate the nidus and to control the extent of its removal. Residual osteoma cavities were additionally treated with an arthroscopic radiofrequency ablator. Microfracturing was performed when the osteochondral defect was in the weight-bearing area and osteochondroplasty was done in cases of concomitant cam deformity. Nonarthritic Hip Score (NAHS), Tegner activity score, quality of life questionnaire (EQ-5D) and postoperative magnetic resonance imaging (MRI) were used for evaluation before and post-surgery, with a minimum follow-up of 2 years.

The relative reduction of the gamma irradiation count immediately after removal of the nidus was 44.9% (range 33.3-54.5%). Postoperatively, all patients experienced prompt pain relief and a significant improvement according to all patient reported outcomes. Control MRI revealed fibro-cartilaginous tissue repair of post-osteoma osteochondral defects in the weight-bearing area; 1 patient showed signs of early degeneration.

The results of this case series demonstrated the safety and high efficacy of gamma-probe-assisted arthroscopic removal of the osteoid osteoma from the hip joint. Endoscopic gamma probe was recognised as a very useful device for locating the nidus of the osteoid osteoma exactly and preventing incomplete or excessive removal of the bone.