pathway

Pathway: A CT scan is performed to localize precisely the lesion. The entry point and the pathway are determined by CT, avoiding nervous vascular and visceral structures.

• For peripheral long bone biopsy : the approach has to be orthogonal to the bone cortex. This approach angle avoids slippage with the tip of the needle. For minimizing as much as possible the tissue lesions during pass through, the shortest way should be chosen. The approach must avoid nervous, vascular, visceral, tendinous structures, and if possible muscular and, if not required, articular structures.

• For flat bones such as scapula, ribs, sternum and skull : we use an oblique approach angle of 30 to 60 degrees. This oblique approach angle is a compromise. The tangential approach is preferred to avoid damage to underlying structures whereas orthogonal angle avoids slippage with the tip of the needle. For the pelvic girdle we use a posterior approach avoiding sacral canal and nerves.

• For vertebral body biopsy : different approach routes can be selected depending on vertebral level : the anterior route for cervical level, the transpedicular and intercostovertebral route for the thoracic level, the posterolateral and the transpedicular route for the lumbar level. For the neural posterior arch we use a tangential approach to avoid the damages to underlying neural structures.

Fig 9: PMSB pathway

Fig 11: Rib oblique approach

Fig 10: Posterior arch oblique approach

Fig 13: Transpedicular route

Fig 12: Transpedicular

Fig 14: Intercostovertebral route