Impact of smoking on the outcome of anterior cervical arthrodesis with interbody or strut-grafting.

BACKGROUND: An increased rate of pseudarthrosis has been documented following posterolateral lumbar spine grafting in patients who smoke. This same relationship has been assumed for anterior cervical interbody grafting, but to our knowledge it has never been proven. This study compared the long-term radiographic and clinical results of smokers and nonsmokers who had undergone arthrodesis with autogenous bone graft following multi-level anterior cervical decompression for the treatment of cervical radiculopathy or myelopathy, or both. METHODS: One hundred and ninety patients were followed clinically and radiographically for at least two years (range, two to fifteen years). Fifty-nine of the patients had corpectomy with strut-grafting, and 131 patients had multiple discectomies and interbody grafting. Fifty-five of the 190 patients had a history of active cigarette-smoking; fifteen of the fifty-five had corpectomy with strut-grafting, and forty had multilevel discectomies and interbody grafting. Internal fixation was not used in any patient. The reconstruction techniques and postoperative bracing regimen were similar between smokers and nonsmokers. Osseous union was judged on dynamic lateral radiographs made at least two years following surgery, and clinical outcomes were judged on the basis of pain level, medication usage, and daily activity level. RESULTS: Of the forty smokers who had undergone multilevel interbody grafting, twenty had a solid fusion at all levels, whereas sixty-nine of the ninety-one nonsmokers had solid fusion at all levels (p < 0.02; chi-square test). This difference was especially pronounced among patients who had had a two-level interbody grafting procedure (p < 0.002; chi-square test). With the numbers available, there was no difference in the rate of fusion between smokers (fourteen of fifteen) and nonsmokers (forty-one of forty-four) who had undergone corpectomy and strut-grafting, as 93% of both groups had a solid union. In addition, clinical outcomes were significantly worse among smokers when compared with nonsmokers (p < 0.03; rank-sum analysis). CONCLUSIONS: Smoking had a significant negative impact on healing and clinical recovery after multilevel anterior cervical decompression and fusion with autogenous interbody graft for radiculopathy or myelopathy. Since smoking had no apparent effect upon the healing of autogenous iliac-crest or fibular strut grafts, subtotal corpectomy and autogenous strut-grafting should be considered when a multilevel anterior cervical decompression and fusion is performed in patients who are unable or unwilling to stop smoking prior to surgical treatment.

Disc degeneration: a human cadaveric study correlating magnetic resonance imaging and quantitative discomanometry.

STUDY DESIGN: This human cadaveric study evaluated disc degeneration of the lumbar spine using magnetic resonance imaging and quantitative discomanometry. OBJECTIVE: To determine if a correlation exists between magnetic resonance imaging and quantitative discomanometry in determining disc degeneration of the lumbar spine. SUMMARY OF BACKGROUND DATA: Several studies analyzing disc degeneration of the lumbar spine have compared magnetic resonance imaging with discography and discomanometry. The reported results are conflicting. No studies exist that compare magnetic resonance imaging and quantitative discomanometry in assessing the disc degeneration of the lumbar spine. METHODS: Three fresh human cadaveric thoracolumbar spine specimens (two T11-S1 and one L1-S1) that included a total of 19 discs were used. Spines were scanned with magnetic resonance imaging, and the scans were read by a neuroradiologist. Using the quantitative discomanometry technique, discs were injected with normal saline, and pressure-volume curves were collected and quantified with six parameters: intrinsic pressure, leakage pressure, initial slope, slope from 0.0 to 0.1 mL, maximum pressure, and volume at maximum pressure. Data analysis was performed using Spearman's Rank Correlation (Rho) statistic. RESULTS: Based on the results from 19 discs, an overall good correlation between magnetic resonance imaging scores and the six quantitative discomanometry parameters was demonstrated. With exception of the volume at maximum pressure, correlation coefficients ranged between 0.61 to 0.78 with a P < 0.05. CONCLUSIONS: Magnetic resonance imaging scores and quantitative discomanometry parameters correlated well in the assessment of disc degeneration of the lumbar spine. Quantitative discomanometry may be an important technique for evaluating early disc degeneration, especially tears of the anular fibers, which may be missed on magnetic resonance imaging.

Quantitative discomanometry: technique and reproducibility in vitro.

Quantitative discomanometry is a study of intradiscal pressure and volume measurements during the injection of fluid into an endplate-disc-endplate complex. The purpose of this article was to describe the technique of quantitative discomanometry, determine the reproducibility of the injection technique in a cadaveric thoracolumbar spine, and standardize the technique for future clinical investigations. Nineteen fresh human cadaveric thoracolumbar discs were injected using quantitative discomanometry to determine: (a) the time necessary for a disc to return to a baseline pressure-volume curve, (b) the reproducibility of the technique in vitro, (c) effects of the injection approach and position of the needle in the disc, and (d) effects of the type and length of tubing as well as gauge of spinal needle. A pressure-volume curve was obtained for each disc injection. Reproducibility was measured by nine parameters obtained from each pressure-volume curve: intrinsic pressure, leakage pressure, initial slope, slope between 0-0.1 ml, slope between 1-4 ml, pressure at 2 ml, pressure at 4 ml, maximum pressure, and volume at maximum pressure. The results demonstrated that (a) the injector apparatus was reproducible, (b) the time necessary for a disc to return to a baseline pressure-volume curve was 24 h, (c) the technique using fresh human cadaveric thoracolumbar discs was reproducible, (d) the anterior and posterolateral approaches had similar results if the needle was placed into the center of the nucleus pulposus using radiographic control, and (e) the type and length of tubing, and gauge of needle did not affect the results.

Total hip arthroplasty performed without cement in patients with femoral head osteonecrosis who are less than 50 years old.

Seventy-two cementless total hip arthroplasties were performed by a single surgeon in 58 patients with the diagnosis of femoral head osteonecrosis. All patients were less than 50 years old (mean, 37 years). The mean follow-up was 84 months with a minimum of 48 months. Good-to-excellent results were maintained at final follow-up in 94% of the hips. Revision rate was 1.5% each for the cups and the stems. Mechanical failure rate was 7.6% for the cups, and 6% for the stems. If the results were analyzed excluding the data from the group of patients who received the Mittelmeier prostheses, the mechanical failure rates for the cups was 0% and for the stems was 4.2%. The probability of survival for the entire series using revision as the endpoint was 96.9% at 11 years. Survival probability decreased to 88.5% if radiographic failures were included. Excluding the Mittelmeier prostheses, survival probability was estimated to be 100% for the cups using both revision and radiographic failures as endpoints; for the stems, the survival probability was 98.0% using revision as the endpoint and 95.8% including radiographic failures. Femoral osteolysis was observed in 1.5% of the hips. No hip had acetabular osteolysis. No measurements of polyethylene wear were attempted in this study. These results appeared superior to total hip arthroplasties done with early cementing techniques in this population of young patients with femoral head osteonecrosis.

Unsatisfactory results of a first-generation modular femoral stem implanted without cement. A 4- to 9-year follow-up study.

Eighty primary total hip arthroplasties were performed using a first-generation modular femoral stem inserted without cement. Modular distal sleeves made of methacrylate were used in 33% of the hips. Dorr type B or C femoral geometry was present in 80% of the cases. The mean follow-up period was 81 months with a minimum of 48 months. Satisfactory clinical results were observed in 74% of the hips at the final follow-up visit. Revision of the stem had been performed in 14% of the hips, all for aseptic loosening. The overall mechanical failure rate was 48%. Canal fill by the stem was not any better with the sleeves than without. The incidence of failure, however, was less in those hips in which sleeves were used. Femoral osteolysis was present in 19% of the hips. The experience with this particular stem design has been disappointing.

Multifocal heterotopic ossification in a patient with sickle cell disease: a case report.

A patient had a sickle cell crisis and developed heterotopic ossification of multiple joints. Many disease entities have been associated with heterotopic ossification; however, heterotopic ossification has rarely, if ever, been associated with sickle cell disease. Only 10% of patients with heterotopic ossification develop ankylosis of their joints. This patient developed ankylosis of several joints. Surgical excision of the periarticular heterotopic ossification allowed full passive motion of the involved joints. After extensive rehabilitation, the patient could perform all activities of daily living and ambulate comfortably without devices.