Hand osteoid osteoma: evaluation of diagnosis and treatment.

Background: OO (osteoid osteoma) is a common, osteoblastic, benign bone tumor but rarely seen in the hand region. There is still some debate about the diagnosis and treatment of hand OOs. In the present study, we aimed to evaluate the epidemiology, radiologic features, surgical treatment options and functional outcomes.
Methods: Between January 2003 and December 2014, surgically treated and pathologically verified 9 hand OO cases were investigated retrospectively. The preoperative and postoperative clinical outcome scores were calculated using the M2-DASH (Manchester-Modified Disabilities of Arm Shoulder and Hand) Score.
Results: Lesion locations were as follows: middle phalanx in 2/9 (22%) patients (2nd and 4th digit), proximal phalanx in 6/9 (67%) patients (one 4th, two 2nd and three 5th digits) and metacarpal (2nd) in 1/9 (11%) patient. Incidence of nidus formation was 6/9 (67%) on X-ray, 7/9 (78%) on CT imaging and 2/9 (22%) on MR imaging. The mean time to diagnosis was 13.22 ± 5.44 months. Preoperative mean M2-DASH score was 41 ± 6 and postoperative was 7.4 ± 8.6.
Conclusion: Osteoid osteoma is usually seen below 25 years, and rarely found over 40 years of age. There is male dominance with a male to female ratio of 3:1. Delay of diagnosis may be encountered because of many differential diagnoses. When OO is suspected, CT imaging should be taken before the MR imaging. Because of superiority in soft tissue imaging, MR imaging should be an alternative tool in complex cases.