Imbibe - Surgical Technique - Pedicle

BMA Surgical Technique
Lumbar Pedicle Approach

The 8-gauge x 6" BMA needle may also be used for bone marrow harvest from the lumbar vertebral bodies via a transpedicular approach. (Fig 12)

The outside diameter of the BMA needle is 4.2mm, similar to most "gearshift" pedicle finder instruments. Using an open technique, the pedicle landmarks are identified and the outer cortex of the pedicle perforated using the surgeon's preferred technique. Prior to any tapping o the pedicle, the BMA needle with bullet-tip stylet is advanced slowly through the pedicle using a back and forth twisting motion. The needle should be advanced to a minimum depth of 2.0 to 2.5cm as judged by the graduated markings on the needle. Once positioned, remove the bullet-tip stylet and aspirate 2 to 4cc of bone marrow with a 10cc or 20cc syringe (a 20cc syringe provides greater vacuum for marrow aspiration).

If deemed appropriate by the operating surgeon, the needle can be advanced another 2cm into the vertebral body and additional bone marrow aspirated. The opposite pedicle of the same vertebra or the second vertebral pedicles can also be used for aspiration.

The pedicle can also be accessed using a percutaneuous approach with flouroscopic guidance. In this case, the BMA needle with a sharp-tip trocar would be utilized in the same fashion as a standard Jamshidi or targeting needle to access the pedicle. After aspiration of marrow from the vertebral body, a guide pin can be inserted if percutaneous spinal instrumentation is utilized.

With a #11 or #15 scalpel, make a stab incision at the desired location over the iliac crest and place the sharp tip BMA needle (Fig 7) through the stab incision down to bone. Use the needle tip to "palpate" the iliac crest and, once the center of the crest is located, seat the needle tip into the cortical bone with one or two brisk taps with a small, lightweight mallet. Using a mallet to advance the needle through bone is the preferred technique as it affords the surgeon greater control of the needle. Advancing the needle by hand often requires excessive downward force and, should the needle suddenly lose contact with bone, may result in perforation of the sacrum or gluteal muscle.