The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects : a seven-year follow-up study.

BACKGROUND: In 1989, a group of sixty-seven asymptomatic individuals with no history of back pain underwent magnetic resonance imaging of the lumbar spine. Twenty-one subjects (31%) had an identifiable abnormality of a disc or of the spinal canal. In the current study, we investigated whether the findings on the scans of the lumbar spine that had been made in 1989 predicted the development of low-back pain in these asymptomatic subjects. METHODS: A questionnaire concerning the development and duration of low-back pain over a seven-year period was sent to the sixty-seven asymptomatic individuals from the 1989 study. A total of fifty subjects completed and returned the questionnaire. A repeat magnetic resonance scan was made for thirty-one of these subjects. Two neuroradiologists and one orthopaedic spine surgeon interpreted the original and repeat scans in a blinded fashion, independent of clinical information. At each disc level, any radiographic abnormality, including bulging or degeneration of the disc, was identified. Radiographic progression was defined as increasing severity of an abnormality at a specific disc level or the involvement of additional levels. RESULTS: Of the fifty subjects who returned the questionnaire, twenty-nine (58%) had no back pain. Low-back pain developed in twenty-one subjects during the seven-year study period. The 1989 scans of these subjects demonstrated normal findings in twelve, a herniated disc in five, stenosis in three, and moderate disc degeneration in one. Eight individuals had radiating leg pain; four of them had had normal findings on the original scans, two had had spinal stenosis, one had had a disc protrusion, and one had had a disc extrusion. In general, repeat magnetic resonance imaging scans revealed a greater frequency of disc herniation, bulging, degeneration, and spinal stenosis than did the original scans. CONCLUSIONS: The findings on magnetic resonance scans were not predictive of the development or duration of low-back pain. Individuals with the longest duration of low-back pain did not have the greatest degree of anatomical abnormality on the original, 1989 scans. Clinical correlation is essential to determine the importance of abnormalities on magnetic resonance images.

Iliosacral screw insertion using computer-assisted CT image guidance: a laboratory study.

Procedures were performed to evaluate the efficacy of using a computer-assisted image-guided system to improve the accuracy of inserting iliosacral screws for posterior pelvic ring injuries. The fluoroscopic method currently in use has shortcomings that do not eliminate the risk to the L5 and sacral nerve roots and iliac vessels. The procedure was performed on embalmed cadaver pelvis specimens with intact soft tissues. Iliosacral screws were inserted across each sacroiliac joint after registering the opposite ilium to simulate a clinical situation. Two trials were performed. The first was necessary to become familiar with the system and test the basic methods of registration. In the second trial, deficiencies were corrected by using spherical-headed fiducial screws for fiducials and a better reference frame clamp, and by better spacing of more fiducials. Results were evaluated by inlet and outlet X-ray views and dissection. All eight S-1 iliosacral 7.0-mm cannulated screws were entirely inside bone. Of the eight S-2 screws, five were inside bone, two infringed upon an S-1 foramen, and one had threads out of the sacral body anteriorly and intruding into an S-1 foramen. This system was felt to be effective and sufficiently safe to warrant clinical trials.

Chest wall fibromatosis associated with silicone breast implants.

Aggressive fibromatosis is a well described locally destructive benign lesion, comprising 0.3% of all solid tumors. Although the chest wall is a common location, this tumour has rarely been associated with breast tissue or breast implants. Herein is only the fourth case described in conjunction with a breast implant and the only case linked to a ruptured silicone implant. This tumour was locally aggressive and required wide surgical resection, including removal of the chest wall, to gain control. Wide surgical resection is recommended with the application of adjuvant radiation therapy being more controversial.