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Study design A prospective, randomized study on patients who underwent posterior lumbar decompression with bilateral posterolateral arthrodesis. Objective To determine the long-term influence of pseudarthrosis on the clinical outcome of patients with degenerative spondylolisthesis and spinal stenosis. Summary of background data Spinal decompression and posterolateral arthrodesis have been shown to be beneficial in the surgical treatment of symptomatic spinal stenosis with concurrent spondylolisthesis. Methods Forty-seven patients with single-level symptomatic spinal stenosis and spondylolisthesis were prospectively studied. Patients were treated with posterior decompression and bilateral posterolateral arthrodesis with autogenous bone graft. Radiographic evaluation was used to determine if fusion or pseudarthrosis was present. The solid fusion and pseudarthrosis groups were analyzed clinically, roentgenographically, and with a validated self-administered spinal stenosis questionnaire. Results Forty-seven patients were available for review at a range of follow-up from 5 to 14 years. Average follow-up was 7 years 8 months. Clinical outcome was excellent to good in 86% of patients with a solid arthrodesis and in 56% of patients with a pseudarthrosis (P = 0.01). Significant differences in residual back and lower limb pain was discovered between the two groups using a scale ranging from 0 (no pain) to 5 (severe pain). Preoperative back and lower limb pain scores were statistically similar between the two groups. The solid fusion group performed significantly better in the symptom severity and physical function categories on the self-administered questionnaire. The two groups had similar results in the patient satisfaction category of this questionnaire. Conclusions In patients undergoing single-level decompression and posterolateral arthrodesis for spinal stenosis and concurrent spondylolisthesis, a solid fusion improves long-term clinical results. Benefits of a successful arthrodesis over pseudarthrosis were demonstrated with respect to back and lower limb symptomatology compared with prior shorter-term studies, which indicated no significant difference in clinical outcome between the two groups.

Stand-alone interbody cages with integrated screws potentially provide a biomechanically stable solution for anterior lumbar interbody fusion (ALIF) that alleviates the need for additional exposure for supplemental fixation, thereby reducing the chance of additional complications and morbidity.To compare the stability of a stand-alone anterior interbody fusion system with integrated fixation screws against traditional supplemental fixation methods and to evaluate the difference between three and four fixation screws in the stand-alone cage.In vitro cadaveric biomechanical study.Eight cadaveric lumbar spines (L2-sacrum) were tested using a flexibility protocol consisting of three cycles to ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The conditions evaluated were intact spine; polyether-ether-ketone cage (zero integrated screws) at L4-L5; cage (zero screws)+bilateral pedicle screws (PS); cage (three screws); cage (four screws); cage (zero screws)+anterior plate; and cage (three screws)+spinous process plate. Motion at the index level was assessed using an optoelectronic system.The cage without integrated screws reduced the motion in flexion-extension and lateral bending (p.001) compared with that in the intact spine. In axial rotation, mean range of motion (ROM) was 8% greater than in intact spine (p.962). The addition of three integrated screws reduced ROM significantly compared with the cage without screws in all motion planes (p.001). A fourth screw had no statistically significant effect on the ROM, although there was a trend toward less motion with four screws compared with three. In flexion-extension, the cage with three integrated screws and the spinous process plate was the most rigid condition. There was no significant difference from the bilateral PS (p=.537); however, this was more rigid than all other conditions (p.024). The most stable condition in lateral bending and axial rotation was the cage with bilateral PS. In lateral bending, the cage (three or four screws) was not significantly different from the cage with anterior plate or the cage (three screws) with spinous process plate fixation; however, only the latter condition was statistically comparable with bilateral PS. In axial rotation, there were no significant differences between the conditions that included integrated screws or supplemental fixation (p.081).Biomechanical testing revealed that the stand-alone cage with integrated screws provides more immediate stability than a cage alone and provides equivalent stability to ALIF constructs with supplemental fixation in lateral bending and axial rotation. Additional flexion-extension rigidity of the anterior cage maybe realized by the addition of a spinous process plate that was found to be as stable as supplemental bilateral PS.

STUDY DESIGN A retrospective study of 103 computed tomography-guided biopsies of the spine. These represent a consecutive series of patients with spinal lesions or disorders observed over a 32-month period. OBJECTIVES To determine the diagnostic accuracy and clinical usefulness of computed tomography-guided biopsies with respect to major influencing variables. SUMMARY OF BACKGROUND DATA Computer tomographic-guided biopsy of the spine is considered a safe, accurate, and relatively inexpensive examination technique. A study comparing its diagnostic accuracy with respect to all the variables of age, gender, radiographic appearance, spinal level, tissue type, or pathologic diagnosis has not been done. METHODS Biopsy specimens were sent for cytologic and histologic analysis. Bacteriologic studies were performed when clinically indicated. The biopsy results were analyzed for adequacy and diagnostic accuracy, i.e., the ability to generate a tissue sample adequate for pathologic examination and one that yields diagnostic information. RESULTS The mean age of patients was 60 years, with a range of 4-91 years. The spines of 52 males and 51 females were studied. There were eight cervical, 28 thoracic, 53 lumbar, and 14 sacral lesions used as biopsy sites. The radiographic appearance of spinal lesions were lytic in 74 cases, blastic in four cases, and mixed in two cases. Tissues undergoing biopsy included bone (63 cases), soft tissue (35 cases), and mixed specimens (five cases). The pathologic examinations revealed 18 infections, 23 primary neoplasms, 34 metastases, and 19 normal tissues. An adequate specimen for pathologic examination was obtained in 90 biopsies (87%). A diagnosis was achieved in 67 of 94 patients (71%). Diagnostic rates obtained in thoracic level biopsies were lower than those from biopsies of other spinal levels (P = .007). CONCLUSION Computed tomography-guided biopsy is an important tool in the evaluation of spinal lesions. A positive biopsy result may preclude the need for open surgical intervention. This study included one of the largest series of patients in the medical literature. In addition, it determined the diagnostic rates of this procedure with respect to the major influencing variables. Thoracic-level biopsies have a diagnostic rate that is significantly lower than that of other spinal levels. No significant correlation was found between diagnostic accuracy and age, gender, radiographic appearance, tissue type, or eventual diagnosis.