Closed Bone Biopsy by a Radiologis

Percutaneous bone biopsy can be performed either by needle aspiration (1, 2) or by obtaining a core of tissue using a Craig needle (3, 4). The latter is a cutting instrument that obtains a core of bone measuring approximately 0.3 em in diameter. By slight modification of the Craig needle, specimens may now be obtained with relative safety under local anesthesia and occasionally on an outpatient basis. The modified Craig needle is used with either biplane image-intensification fluoroscopy or some type of C-arm that allows needle positioning in two planes. These modifications consist of fashioning each step of the procedure so that a needle can be inserted for local anesthesia as well as for anchoring the instrument (Fig. 1). Technic The patient is positioned on the x-ray table so that the bone to be biopsied can be visualized in two pro jections under image-intensification control. After careful sterile preparation of the skin, a stab wound of approximately 8 mm in length is made under local anesthesia. Local anesthesia is then infiltrated along the projected track of the needle down to the area of the bone. The blunt cannula is inserted down to the bone, and if the patient experiences any pain during this passage the obturator is removed. The central needle is inserted into the cannula, and local anesthesia is injected. After the blunt cannula is directed to the desired site of biopsy, the anchoring needle is inserted into the lumen of the cannula and is passed into the periosteum and cortex of the bone to firmly anchor the blunt cannula. Its position is verified by biplane fluoroscopy. Over the top of the blunt cannula the sleeve is inserted down to the level of the bone. A tube in the sleeve allows an additional needle to be placed in the wall of the sleeve for any needed local anesthesia and later, after the sleeve has been placed down to the bone to be biopsied, this same anesthesia needle will serve as an anchoring needle. Once the sleeve is in position the blunt cannula is removed, and the cutting instrument is inserted through the sleeve. If there is any tendency for the cutting instrument to wander, an anchoring needle can be placed through its lumen to prevent slippage of the biopsy instrument. The cutting instrument is inserted into the bone with a twisting action until the desired depth of specimen has been obtained. This is usually 10–15 mm in length. A clasping worm instrument is inserted through the cutting instrument to insure that the specimen is not lost in the sleeve and biopsy hole. After the specimen is removed, together with the cutting instrument, a tamponading instrument is inserted into the bony defect to control bleeding. After seven to ten minutes the tamponading instrument is removed from the sleeve and the lumen of the sleeve observed to insure that bleeding has, in fact, been controlled. Once satisfied, the radiologist removes the sleeve and compresses the puncture site for four to five minutes. No sutures are required, nor is drainage necessary.