The effect of torque pressure on halo pin complication rates. A randomized prospective study.

At Thomas Jefferson University Hospital, 102 consecutive patients treated in a halo vest orthosis were randomized into one of two torque protocol groups based on their date of birth. The pins of patients who were born in even-numbered months were inserted with 8 inch-lbs of torque and those born in odd-numbered months were inserted with 6 inch-lbs. All patients were placed in an identical model halo using a standardized technique of application. The patients were followed prospectively, and all potential complications were evaluated by a member of the orthopedic attending staff, using protocols established at the onset of the study. Statistical analysis indicated no significant differences in halo pin loosening, infection, pain, or scarring between the torque protocols, but there was a trend toward a higher complication rate in the 8-inch-lbs group. There was no direct evidence of skull penetration in either group, and no patients developed a deep infection. Based on the results of this study, we conclude that insertion torque has no significant effect on halo pin complications within the ranges tested by this study. Our current protocol calls for routine insertion of halo pins with 6 inch-lbs of torque.

MRI evaluation of fusion mass incorporation after anterior cervical bony fusions: preliminary findings.

While Modic has described certain MRI changes in bone grafts in patients after anterior cervical discectomy and fusion (ACF), no study has evaluated specific MRI signal changes in the fusion mass prospectively and longitudinally. The goal of the present study was to prospectively evaluate MRI changes in ACF grafts in a longitudinal fashion. Twenty-seven MRIs were included in the evaluation of seven postoperative patients. MRIs were obtained in a 1.5 tesla GE imager immediately postoperatively, and at 1, 3, and 6 months in most patients. All patients received at least three sequential MRIs. Two patients had greater than one level fused. T1 and T2 images were evaluated in all patients at each available interval. GRASS images were not found to be helpful secondary to a prohibitive amount of noise. For single level fusion masses, T1 images showed a very intense homogeneous graft signal in the immediate postoperative period which decreased slightly at 1 month. At 3 months the signal intensity of the graft was similar to the 1 month image, but was slightly less homogeneous. At 6 months, the T1 signal had greatly decreased in much of the graft. Immediate postoperative specimens showed heterogeneously high signal on T2 images which increased at 1 month in the whole graft, and then seemed to increase at the endplates while decreasing in the graft at 3 months. At 6 months the graft was becoming difficult to delineate on T2 images in many specimens. The two and three level fusions had a more heterogeneous image progression without clear evidence of solid fusion at 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Intervertebral disc injury complicating cervical spine trauma.

The incidence of acute herniated nucleus pulposus was determined in 55 patients with cervical spine trauma. A standardized protocol and a 1.5-T magnetic resonance image scanner was used to document a 42% incidence of acute herniated nucleus pulposus in patients studied within 72 hours of injury. The incidence of herniated nucleus pulposus was correlated with the patients' presenting neurologic status and mechanism of injury. The incidence of herniated nucleus pulposus was highest in patients with bilateral facet dislocations (80%) and anterior cord syndromes (100%). There was no statistically significant correlation between the incidence of herniated nucleus pulposus and patients' age or sex.

Curve progression after treatment with the Wilmington brace for idiopathic scoliosis.

We evaluated curve progression after completion of Wilmington brace treatment for adolescent idiopathic scoliosis in 67 patients. Follow-up ranged from 5 to 13 years. Pretreatment curve magnitudes ranged from 20 to 39 degrees, with a Risser sign of 0 or 1. Sixteen patients (21%) experienced 5-16 degrees of curve progression after brace treatment was discontinued. For nine of these patients, the final curve magnitude was within 5 degrees of the pretreatment Cobb angle, reflecting a loss of correction achieved during brace treatment. The remaining seven patients had final curve magnitudes measuring 8-32 degrees greater than the pretreatment Cobb angle.

Neuropathic spinal arthropathy in congenital insensitivity to pain.

Neuropathic arthropathy developed in the lumbar spine of a 28-year-old woman with congenital insensitivity to pain. Progressive spinal instability and destruction occurred at the L1-L2 interspace, with resultant kyphosis. Successful arthrodesis was obtained with staged posterior and anterior procedures.