gms | German Medical Science

Objectives/Interrogation: Osteoid osteoma predominantly develops in the cortex of long bones and the spine,but rarely in the carpal bones. We report two cases of osteoid osteoma in the carpal bones,one in the hamate and another in the capitate.

Methods: Case 1: A 10-year-old girl who danced hip-hop presented with pain and swelling in the back of the right hand 1 month earlier. The ROM associated with pain was 45° for dorsiflexion(DF)and 60° for palmar flexion(PF). Xray revealed sclerosis in the hamate. CT revealed a concave area in the cortex of the articular surfaces of the hamate and triquetrum, with shadows indicating bone fragments. T1- and T2-weighted MRI revealed decreased intensity at the same site. As she reported that she often spun on her hands during dance performance, osteochondritis dissecans of the articular surfaces of the hamate and triquetrum was initially suspected; thus, conservative treatment was initiated. However, the pain did not improve after 6 months, and Xray revealed bone atrophy. As aspirin was markedly effective, osteoid osteoma was suspected, but no tumor was detected in the CT-guided biopsy. One year after the initial visit, she underwent curettage of the hamate followed by iliac bone grafting, which improved the symptoms.

Case 2: A 29-year-old male firefighter presented with a chief complaint of pain in the left hand. Six months earlier, pain occurred on the ulnar side with no apparent cause, which made push-ups difficult and led to his visit to our hospital on referral by his local physician. The dorsum of his left hand was mildly swollen, with tenderness on the dorsal aspect of the capitate. The pain ROM as 80°/70° =DF/PF. The grip strength relative to the unaffected hand was reduced to 78%. Pain intensified at night but was alleviated by Bufferin. CT and contrast-enhanced MRI revealed a nidus in contact with the articular surfaces of the capitate and hamate. En bloc excision was performed via the dorsal side under conduction anesthesia, immediately followed by CT to confirm that the nidus had disappeared. The pathological examination results were assessed, and iliac bone grafting was later performed. On pathological examination, a newly formed osteoid was found. Complete bone healing was observed. At 13 months later, the pain had disappeared. The ROM was still mildly restricted, but the grip strength increased to 105%. Imaging results indicated no tumor recurrence and bone healing.

Results and Conclusions: Though rarely, an osteoid osteoma can be accompanied by pain and swelling in the hand.