Purpose: To describe the percutaneous transpedicular biopsy technique as a novel way of approaching lesion of the thoracic and lumbar spine, to determine the amount of bone retrievable through the pedicle and its diagnostic yield. Material and Methods: Seventy-nine patients underwent 84 biopsies. Seventy-seven procedures were performed with ßuoroscopic guidance arid seven with CT guidance. Seventy-one biopsies underwent under local anesthesia and ten under general anesthesia. Age range of patient was from 3 to 81 years. Results: Adequate specimens for correct diagnosis were obtained in 80 of the 84 patients with the following diagnoses. Pyogenic spondylodiscitis 31, tuberculosis 4, coccidiomycosis 2, echinococcus cyst 1, blastomycosis 1, brucella 4, primary neoplasm 7, metastatic neoplasms 16, osteoporotic fractures 8, osseous repair for insufþciency fractures 5, Pagetñs disease 1. The 4 negative biopsies subsequently proven to be Ç false negative È and were related to faulty biopsy techniques. Conclusion: Pitfalls can be avoided when adhering to the details of our technique. These pitfalls can occur while retrieving the instrumentation without simultaneous withdrawal of the guiding pin; crushing pathological soft tissue against sclerotic or normal bone; or when encountering a sclerotic lesion distal to normal bone without using a sequential type of biopsy specimen-retrieval technique. Any type of bleeding is controllable. The approach is a safe, efþcacious and cost effective and avoids so the problems such low diagnostic yield nerve root injury, pneumothorax and hematoma encountered with conventional needle technique

A new dynamic classification of Paget's disease is proposed, incorporating both the radiographic phases of bone remodelling and the scintigraphic findings. Osteolytic, mixed and osteoblastic phases are associated with increased scintigraphic activity, while the osteosclerotic phase of remodelling is associated with normal or diminished activity and an osteoblastic radiographic appearance. Abnormal modelling of bone leading to deformity is produced by accelerated apposition or absorption at the periosteal and endosteal envelopes of the bone. In 112 patients with symptoms from Paget's disease, 527 lesions were classified. The most frequent remodelling phase was the mixed one and the most common modelling state was bone expansion with endosteal and periosteal apposition. Of 88 patients treated medically, 12 had lesions which progressed to increased bone formation without a change in modelling, and the active lesions in seven patients became inactive. Prolonged treatment with disodium etidronate led to progressive osteopenia in 11 patients.