Arthroscopic Excision of an Osteoid Osteoma of the Lesser Trochanter of the Femoral Neck

A CT-free protocol to treat osteoid osteoma of the hip region in childhood and adolescence by percutaneous drilling and by hip arthroscopy

INTRODUCTION

It is often difficult to clinically and radiologically diagnose intra-articular osteoid osteomas and osteoid osteomas of the hip joint. Treatment can also be difficult due to complex locational relationships. CT-guided radiofrequency ablation is currently the standard form of treatment.In this paper we report on a minimally-invasive concept for treating osteoid osteomas near the hip joint in children and adolescents which does not involve using computed tomography.

MATERIAL AND METHOD

10 patients with an average age of 12.1 years underwent treatment for osteoid osteomas in the hip joint region. The diagnosis was made using a contrast-enhanced MRI. The osteoid osteomas were marked percutaneously using x-ray and MRI guidance. MRI-guided drilling/curettage was performed in 4 cases and arthroscopic resection in 6 cases.

RESULTS

All lesions were successfully treated using the MRI-guided method. All patients were free of pain after the treatment. There was no instance of recurrence during the follow-up period, which averaged 10 months. The effective dose for marking the lesion was between 0.0186 mSv and 0.342 mSV (mean 0.084 mSV).

CONCLUSIONS

Our MRI diagnostics protocol, the MRI-guided drilling and the minimally invasive hip arthroscopy represent an alternative to CT-guided radiofrequency ablation in the treatment of osteoid osteomas. Radiation exposure can thereby be significantly reduced. Hip arthroscopy can also be used to treat secondary pathologies such as femoroacetabular impingement.

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

AIM

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.