[Osteoid Osteoma of the Upper Extremity].

PURPOSE OF THE STUDY Osteoid osteoma (OO) of the upper extremity is a rare pathology representing a major diagnostic challenge. The patients are often times incorrectly treated due to a misdiagnosis and therefore the final management of symptoms is delayed by several months. During this time the pain, which is the main symptom, increases. The surgical treatment is a fast and efficient solution. This paper aims to highlight the specificity of the OO of the upper extremity, evaluate our study group, the time to diagnosis and the benefits of individual imaging techniques. MATERIAL AND METHODS In the period 2007-2017, a total of 8 patients with a histologically verified OO of the upper extremity were consulted and treated at the authors departments. The group of patients was retrospectively evaluated based on the medical reports, surgical protocols, imaging examinations, histology results of preoperative samples and a postoperative questionnaire. Pain was assessed on the Visual Analogue Scale (VAS) preoperatively, at 2 weeks, 2 months and at one year postoperatively and in January 2018. The mean follow-up period was 48 months (range 16-78). The presence of swelling, synovitis and a limited range of motion were clinically assessed. The removed tissue was tested in an accredited biopsy laboratory. RESULTS 8 patients with OO of the elbow, wrist and hand were treated in the period 2007-2017. In 5 cases the OO was located in the wrist (scaphoid, 2x trapezoid, hamate and capitate) and in 2 cases in finger phalanges (middle and distal phalanx). The mean age of the patients was 24.5 years (median 21.5, range 18-42). The male to female ratio was 7:1. The mean interval between the onset of symptoms and the final diagnosis was 16.25 months (median 15.5, range 12-25). The CT examination proved to be the most beneficial imaging techniques. A plain radiograph led to a diagnosis in 1 case only. The preoperative mean pain VAS value 9.25 dropped to VAS 1 at two weeks after the surgery. No recurrence was reported. DISCUSSION The main challenge in treating the OO of the upper extremity is the diagnosis. Despite of the availability of advanced imaging techniques, the interval from the onset of symptoms to correct diagnosis did not change over the past decades. As to the treatment, despite the development of new procedures the method of choice continues to be the surgical excochleation. CONCLUSIONS Osteoid osteoma of the upper extremity is a rare pathology which shall be considered in case of an increasing pain, especially in young men. A plain radiograph of the anatomically complex terrain of the hand and wrist is mostly not useful in diagnosis, whereas the CT examination can visualise even a small size nidus. The surgical excochleation results in pain relief and early functional recovery with swelling disappearance. To diagnose the OO is not difficult provided we take it into consideration. Key words:osteoid osteoma, upper extremity, hand, wrist, diagnosis.