Use of pedicle screw fixation in the management of malignant spinal disease: experience in 100 consecutive procedures

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Object. Few reports are available on the use of pedicle screw fixation for cancer-related spinal instability. The authors present their experience with pedicle screw fixation in the management of malignant spinal column tumors.

Methods. Records for patients with malignant spinal tumors who underwent pedicle screw fixation at the authors' institution between September 1994 and December 1999 were retrospectively reviewed.

Results. Ninety-five patients with malignant spinal tumors underwent 100 surgeries involving pedicle screw fixation: metastatic spinal disease was present in 81 patients, and locally invasive tumors were demonstrated in 14 patients. Indications for surgery were pain (98%) and/or neurological dysfunction (80%). A posterior (48%) or a combined anterior—posterior (52%) approach was performed depending on the extent of tumor and the patient's condition. At the mean follow up of 8.2 months, 43 patients (45%) had died; median survival, as determined by Kaplan—Meier analysis, was 14.8 months. At 1 month postsurgery, self-reported pain had improved in 87% of cases (p < 0.001), which is a finding substantiated by reductions in analgesic use, and 29 (47%) of 62 patients with preoperative neurological impairments were functionally improved (p < 0.001). Postoperative complications were associated only with preoperative radiation therapy (p = 0.002) and with preexisting serious medical conditions (p = 0.04). In two patients asymptomatic violation of the lateral wall of the pedicle was revealed on postoperative radiography. The 30-day mortality rate was 1%.

Conclusions. For selected patients with malignant spinal tumors, pedicle screw fixation after tumor resection may provide considerable pain relief and restore or preserve ambulation with acceptable rates of morbidity and mortality.

Article Information

Address reprint requests to: Ziya L. Gokaslan, M.D., Department of Neurosurgery, Box 64, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030. email: zgokasla@notes.mdacc.tmc.edu.

© AANS, except where prohibited by US copyright law.

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Figures

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    Artist's rendering. A tumor has been resected posteriorly and stabilization has been performed using pedicle screws.

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    Representative neuroimaging studies obtained in a patient with hepatocellular carcinoma that metastasized to L-1. Axial (A) and sagittal (B) T1-weighted MR images demonstrating significant involvement of the posterior elements with tumor and compression of the thecal sac. After a posterior tumor resection and stabilization, anteroposterior (C) and lateral (D) plain radiographs demonstrate the three-level stabilization with pedicle screws.

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    Representative neuroimaging studies obtained in a patient with metastatic leiomyosarcoma of the uterus that metastasized to L-4. Computerized tomography (A) and enhanced sagittal T1-weighted MR (B) images revealing a lytic process involving the anterior and middle spinal columns. This female patient underwent an anterior tumor resection and reconstruction by implanting MMA via a retroperitoneal approach and, 7 days later, a posterior stabilization procedure. Anteroposterior (C) and lateral (D) plain x-ray films obtained after the second stage of the procedure demonstrating the three-level posterior stabilization with pedicle screws and the anterior reconstruction materials.

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    Representative neuroimaging studies obtained in a patient with follicular carcinoma of the thyroid metastatic to T12—L2. Five years previously, she underwent an anterior decompressive and reconstruction procedure in which a rib graft was placed at L-1 for a traumatic fracture. Preoperative (A) and postoperative (B) sagittal T1-weighted MR images demonstrating tumor resection and anterior column reconstruction in which MMA and thoracolumbar locking plate and screw system were applied. Seven days later, the patient underwent posterior stabilization and T9—L4 fusion in which a pedicle screw and hook system was used. Anteroposterior (C) and lateral (D) plain radiographs obtained 3 years postoperatively revealing no evidence of construct failure.

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    Bar graph showing median VAS pain scores at preoperative, postoperative, and follow-up evaluations in 98 cases in which pain was a significant preoperative complaint. A score of 10 indicates severe pain and a score of 0 indicates no pain. n = number of cases at each interval.

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    Kaplan—Meier survival curves. Upper: Overall survival curve for 95 patients who underwent pedicle screw fixation for malignant spinal disease. Lower: Survival estimates for patients with the four most commonly encountered metastatic tumors: breast (short-dash line), renal cell (unbroken line), melanoma or sarcoma (long-dash line), and lung cancer (long-and-short-dash line). Survival curves were estimated using the Kaplan—Meier product-limit method.

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