✓ Odontoid fractures are a common traumatic upper cervical spine injury. Treatment of Type III odontoid fractures includes skeletal traction for realignment and halo vest immobilization. The authors report an unusual case of severe atlantoaxial ligamentous disruption accompanying a traumatic Type III odontoid fracture. Five pounds of skeletal traction was associated with marked neurological deterioration from unanticipated longitudinal instability. Radiographic findings were identified that were suggestive of extensive ligamentous disruption. Recommendations for individualized patient management are given in the context of related literature.
Case report and review of the literature
Gregory J. Przybylski and William C. Welch
Peter C. Gerszten and William C. Welch
✓Percutaneous balloon kyphoplasty has become a widely adopted treatment option for patients with pain due to pathological compression fractures. One potential risk of the procedure is the displacement of tumor into the spinal canal and resulting spinal cord or cauda equina injury during inflation of the balloon prior to polymethylmethacrylate (PMMA) placement. In addition, the presence of any remaining tumor between the PMMA and the fractured cortical bone can lead to suboptimal improvement in stabilization and subsequent pain relief. The authors describe a technique to remove tumor from within the vertebral body (VB) through a percutaneous working channel prior to kyphoplasty balloon inflation and augmentation.
The technique was successfully used in all three patients who had presented with pain, and the pain improved in all three cases. There was no extravasation of PMMA into the spinal canal in any case.
A combined VB tumor debulking and kyphoplasty technique offers the ability to improve the placement of PMMA within the diseased vertebral body, potentially leading to increased safety as well as clinical effectiveness for stabilization of these fractures.
William C. Welch and Peter C. Gerszten
In recent years the general trend in spinal surgery has been one of reductionism and minimalization. A number of techniques have recently been developed that are applicable in the treatment of lumbar disc herniation and discogenic pain due to degenerative disc disease. The purpose of this manuscript is to examine two newer percutaneous disc treatment techniques, intradiscal electrothermal therapy (IDET) anuloplasty and nucleoplasty. The authors review the appropriate clinical treatment criteria, techniques, and lessons learned after performing these procedures in more than 100 patients.
The IDET involves the percutaneous insertion of a specially designed thermal resistance probe followed by controlled heating of the intervertebral disc. This may result in disc shrinkage and reduction in pain. The nucleoplasty procedure involves the percutaneous removal of disc material by using a low-temperature resister probe to disintegrate and evacuate disc material, followed by thermal treatment of adjacent residual disc material. To date, no study has been published in which investigators examine the outcomes of this procedure for the treatment of radicular leg pain and low-back pain.
Both IDET and nucleoplasty appear to be safe procedures. The IDET procedure may be an alternative to lumbar interbody fusion. Although its long-term role is being defined, this technique appears to provide intermediate-term relief of pain in a population of patients with discogenic low-back pain. Nucleoplasty may provide a percutaneous alternative to microdiscectomy in selected cases.
William C. Welch, Robert D. Rose, Jeffrey R. Balzer, and George B. Jacobs
✓ The neuroanatomical structures that approximate the bony pedicles of the lumbar spine allow little room for technical error or compromise of the bone during pedicle screw insertion. Currently available neurophysiological monitoring techniques detect compromised bone and nerve root injury after it occurs. The purpose of this prospective study is to evaluate the reliability and efficacy of a unique neurophysiological monitoring technique. This technique provides immediate evaluation of pedicle cortical bone integrity in patients undergoing lumbar fusion with instrumentation by using electrified surgical instruments throughout the pedicle screw fusion procedure. Spontaneous electromyographic (EMG) activity was also monitored.
Intraoperative evoked EMG stimulation was performed using a pedicle probe and feeler as monopolar stimulators during the insertion of 164 pedicle bone screws in 32 patients. The EMG response to subthreshold stimulation intensities indicated cortical bone compromise. Immediate and conclusive feedback via evoked EMG activity using stimulating pedicle probes in appropriate muscle groups was successful in identifying pedicle cortical bone compromise in four patients. One false-negative evoked EMG study was noted but was identified via spontaneous EMG activity. Intraoperative EMG monitoring alerted the surgeon that redirection of the pedicle probe or screw was necessary to avoid nerve root irritation or injury and served as an early warning system.
Evoked EMG stimulation proved to be reliable and efficacious, especially when used in combination with spontaneous EMG. This technique may provide an added safeguard during implant placement procedures at centers where intraoperative neurophysiological monitoring is routinely performed.
Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2005
Peter C. Gerszten, William C. Welch, and Joseph T. King Jr.
Nucleoplasty is a minimally invasive surgical procedure for disc decompression developed to treat patients with symptomatic contained herniated discs. Nucleoplasty uses nonheat-driven radiofrequency energy to ablate and coagulate the disc nucleus via a percutaneous “discography” trajectory under fluoroscopic guidance. In this study the authors evaluated pain, functioning, and quality of life (QOL) in patients with radicular leg and back pain who underwent nucleoplasty-based percutaneous disc decompression.
The study was designed as a prospective nonrandomized longitudinal cohort study in an academic medical center. Sixty-seven patients (mean age 41 years) with primarily radicular pain due to a contained disc herniation underwent nucleoplasty-based decompression in an outpatient setting. Patients completed the Medical Outcomes Study 36-Item Short Form (SF-36) Health Survey, EuroQol 5D (EQ5D), and a visual analog scale (VAS) for pain pre-operatively, and at 3 and 6 months after surgery. Postoperative QOL differences were assessed using the Wilcoxon signed-rank test. A surgical probe, the Perc-DLE SpineWand, was placed percutaneously into the disc after application of a local anesthetic or induction of general anesthesia to remove part of the disc (that is, a percutaneous discectomy).
Nucleoplasty-treated levels were L2–3 (one case), L3–4 (five cases), L4–5 (44 cases), and L5–S1 (40 cases); there were 22 multiple treatment levels and 42 bilateral treatments. There were no infections or nerve root injuries associated with the procedure. Compared with preoperative QOL, there was a statistically significant improvement in QOL at 3 months as measured using the SF-36 Physical Component Summary (PCS) scale (mean score improvement 4.4 [p = 0.014]), the EQ5D (mean score improvement 0.22 [p = 0.001]), and the VAS for pain (mean score improvement 0.13 [p = 0.02]). Six-month results in 36 patients continued to reflect improvement as measured using the SF-36 PCS (mean score improvement 7.6 [p = 0.002]) and the EQ5D (mean score improvement 0.27 [p = 0.001]).
Nucleoplasty-based percutaneous disc decompression in patients with symptomatic contained disc herniations is safe and improves QOL as measured by the SF-36, EQ5D, and VAS for pain, three generic QOL outcome instruments. Nucleoplasty is an effective minimally invasive surgical treatment alternative in patients with symptomatic contained disc herniations. Further follow-up evaluation is underway to determine the durability of QOL improvement after nucleoplasty.
Peter C. Gerszten, John J. Moossy, John C. Flickinger, and William C. Welch
Object. The authors of clinical studies have demonstrated a significant association between the presence of extensive post—lumbar discectomy peridural scar formation and the recurrence of low-back and radicular pain. Low-dose perioperative radiotherapy has been demonstrated to inhibit peridural fibrosis after laminectomy in animal models. The present study was designed to evaluate the clinical efficacy of preoperative irradiation in patients with failed—back surgery syndrome due to peridural fibrosis who underwent reexploration and nerve root decompression.
Methods. Ten patients with symptomatic post—discectomy peridural fibrosis were randomized. Half of the patients underwent 700-cGy external-beam irradiation to the operative site 24 hours prior to reexploration and decompressive treatment of their symptomatic nerve root(s) (treatment group) and the other half underwent reexploration and decompressive treatment without preoperative irradiation (control group). All patients underwent simulated irradiation so neither patient nor surgeon was aware of the patient's group. In all patients the antiadhesion product ADCON-L was placed over the affected nerve root at the time of surgery. Clinical outcome was assessed using the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section Lumbar Disc Herniation Study Questionnaire at baseline, 6 weeks, 3 months, and 1 year follow up.
Five men and five women (mean age 42 years) underwent randomization and surgery. Three patients underwent reexploration at L4–5, four at L5—S1, and three at both levels. No complication was associated with irradiation, and no new neurological deficits occurred. At 1-year follow-up examination, three irradiation-treated patients were pain free and two experienced improvement. In the control group, three patients experienced improved pain relief and two were unchanged. There was a trend toward better outcome at 1 year in the radiotherapy-treated group (p = 0.056).
Conclusions. Preoperative low-dose external-beam irradiation improved clinical outcomes after reexploration and decompression of nerve roots affected by postlaminectomy peridural fibrosis causing radicular pain. The addition of preoperative irradiation may improve outcome in patients who undergo reoperation for recurrent radicular pain associated with a significant amount of peridural fibrosis, particularly now that no antiadhesion product is available for clinical use.
Peter C. Gerszten, Cihat Ozhasoglu, Steven A. Burton, Shalom Kalnicki, and William C. Welch
The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. Its use for the treatment of spinal lesions has been limited by the availability of effective target-immobilizing devices. In this study the authors evaluated the CyberKnife Real-Time Image-Guided Radiosurgery System for spinal lesion treatment involving a single-fraction radiosurgical technique.
This frameless image-guided radiosurgery system uses the coupling of an orthogonal pair of x-ray cameras to a dynamically manipulated robot-mounted linear accelerator possessing six degrees of freedom, which guides the therapy beam to the target without the use of frame-based fixation. Cervical lesions were located and tracked relative to osseous skull landmarks; lower spinal lesions were tracked relative to percutaneously placed gold fiducial bone markers. Fifty-six spinal lesions in 46 consecutive patients were treated using single-fraction radiosurgery (26 cervical, 15 thoracic, and 11 lumbar, and four sacral). There were 11 benign and 45 metastatic lesions.
Tumor volume ranged from 0.3 to 168 ml (mean 26.7 ml). Thirty-one lesions had previously received external-beam radiotherapy with maximum spinal cord doses. Dose plans were calculated based on computerized tomography scans acquired using 1.25-mm slices. Tumor dose was maintained at 12 to 18 Gy to the 80% isodose line; spinal cord lesions receiving greater than 8 Gy ranged from 0 to 1.3 ml (mean 0.3 ml). All patients tolerated the procedure in an outpatient setting. No acute radiation-induced toxicity or new neurological deficits occurred during the follow-up period. Axial and radicular pain improved in all patients who were symptomatic prior to treatment.
Spinal stereotactic radiosurgery involving a frameless image-guided system was found to be feasible and safe. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and symptomatic response. This procedure offers a successful alternative therapeutic modality for the treatment of a variety of spinal lesions not amenable to open surgical techniques; the intervention can be performed in medically untreatable patients, lesions located in previously irradiated sites, or as an adjunct to surgery.
Peter C. Gerszten, Steven A. Burton, Cihat Ozhasoglu, William J. Vogel, William C. Welch, Joseph Baar, and David F. Friedland
Object. The role of stereotactic radiosurgery in treating renal cell carcinoma (RCC) metastases to the spine has previously been limited. In this study the authors evaluated the clinical outcome in patients with spinal RCC who underwent single-fraction radiosurgery.
Methods. Forty-eight patients with 60 RCC metastases to the spine (six cervical, 26 thoracic, 18 lumbar, and 10 sacral) were treated with a single-fraction radiosurgery technique and were followed for a period of 14 to 48 months (median 37 months).
All patients were successfully treated in an outpatient setting. The tumor volume ranged from 5.5 to 203 cm3 (mean 61.9 cm3). Forty-two of the total 60 lesions had been previously treated with external-beam radiation therapy (EBRT). The maximum tumor dose was maintained at 17.5 to 25 Gy (mean 20 Gy). The volume of the spinal cord exposed to greater than 8 Gy ranged from 0.01 to 3 cm3 (mean 0.64 cm3); the volume of the spinal canal at the cauda equina level exposed to greater than 8 Gy ranged from 0.01 to 2.2 cm3 (mean 0.65 cm3). No radiation-induced toxicity occurred during the follow-up period. Axial and radicular pain improved in 34 (89%) of 38 patients who were treated primarily for pain. Tumor control was demonstrated in seven of eight patients treated primarily for radiographically documented tumor progression. In time six patients required open surgical intervention for tumor progression that had caused neurological dysfunction after radiosurgery.
Conclusions. Spinal radiosurgery can be a successful therapeutic modality for the delivery of large-dose single-fraction radiation to RCC spinal metastases that are often poorly controlled with conventional EBRT modalities.
Peter C. Gerszten, Anand Germanwala, Steven A. Burton, William C. Welch, Cihat Ozhasoglu, and William J. Vogel
Patients with symptomatic pathological compression fractures require a stabilization procedure for mechanical control of back pain as well as radiation therapy for the underlying malignant process. In this study the authors evaluated a treatment paradigm of closed fracture reduction and fixation in which kyphoplasty was used, followed by single-fraction spinal radiosurgery performed with the CyberKnife.
Twenty-six patients (six men and 20 women, mean age 72 years) with histologically confirmed pathological compression fractures (16 thoracic, 10 lumbar) were prospectively evaluated. For inclusion in the study, the patients' presenting symptoms were limited to pain without neurological deficits. Histological findings included 11 lung, nine breast, and four renal carcinomas, one cholangiocarcinoma, and one ocular melanoma. All patients underwent kyphoplasty of the affected vertebral body, for which a percutaneous transpedicular procedure was used. Fiducial markers that allow image guidance for CyberKnife radiosurgery were placed into the pedicles at the adjacent levels at the time of the kyphoplasty procedure. Patients then underwent single-fraction radiosurgery (at a mean of 12 days after kyphoplasty) in an outpatient setting. The tumor dose was maintained at 16 to 20 Gy to the 80% isodose line (mean 18 Gy). Treated tumor volume ranged from 12.7 to 37.1 cm3. Axial pain improved in 24 (92%) of 26 patients during the follow-up period of 7 to 20 months.
A combined kyphoplasty and spinal radiosurgery treatment paradigm was found to be safe and clinically effective for patients with pathological fractures without significant spinal canal compromise. This technique combines two minimally invasive surgical procedures, thereby avoiding the morbidity associated with open surgery while providing immediate fracture fixation as well as a single-fraction tumoricidal radiation dose.