Robert F. Heary
Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004
Robert F. Heary
✓ Spinal deformity is a complex and dynamic process that occurs in both the sagittal and coronal planes of the thoracolumbar spine. Successful treatment is aimed at achieving satisfactory balance in both of these planes. The spinal curvatures in the adult differ greatly from those in adolescents. As a general rule the adult curves tend to be stiffer, whereas adolescent curves are more flexible. In addition to cosmetic concerns, adult patients frequently present with pain and neurological symptoms in contrast to adolescents who usually do not experience this degree of pain or neurological symptoms. The treatment of adult spinal deformity differs substantially from that of adolescent deformity. Surgeries in the former tend to be more complex procedures associated with higher rates of intra- and perioperative complications. The goals of surgery in the adult are to obtain a solid fusion with a balanced spine, to relieve pain, and to prevent further deformity. A secondary goal is to correct the curve, and, in so doing, to improve the cosmetic appearance. In this review the author addresses the basic principles of spinal corrective surgery in the adult and provides insight into the varied treatment options available.
Robert F. Heary
Robert F. Heary and Reza J. Karimi
The authors describe a surgical technique for the correction of symptomatic degenerative lumbar scoliosis. Using a single, unilateral, interbody cage placed on the concave side of the coronal deformity, combined with a dorsal decompression and instrumented posterolateral fusion, this technique has resulted in excellent curve correction, fusion results, and clinical outcomes in a series of 4 patients. Each of these patients presented with intractable, axial low-back pain and symptomatic unilateral nerve root compression on the concave side of a lumbar scoliotic deformity. The management is described in detail.
Robert F. Heary and Christopher M. Bono
There are many options for the surgical treatment of lumbar spondylolisthesis, including anterior and posterior techniques. Among the most versatile is a 360° fusion. In consideration of the added risk of morbidity of two procedures, circumferential fusion leads to the highest fusion rates. This is particularly useful for patients at high risk for pseudarthrosis, such as patients with diabetes, posttransplant recipients, and those in whom fusion procedures have failed. Likewise, a 360° fusion may also be useful in achieving fusion in biomechanically disadvantageous situations, such as at the L5–S1 level or with high-grade subluxation. The options for 360° fusion are many and are determined, among other factors, by surgical pathology and surgeon preference. Standard open techniques are still considered the gold standard, although newer less invasive methods of circumferential fusion are being used more frequently. The operating surgeon must have a thorough knowledge of all available maneuvers for critical and effective decision making.
Robert F. Heary and Christopher M. Bono
Metastatic spinal tumors are the most common type of malignant lesions of the spine. Prompt diagnosis and identification of the primary malignancy is crucial to overall treatment. Numerous factors affect outcome including the nature of the primary cancer, the number of lesions, the presence of distant nonskeletal metastases, and the presence and/or severity of spinal cord compression. Initial management consists of chemotherapy, external beam radiotherapy, and external orthoses. Surgical intervention must be carefully considered in each case. Patients expected to live longer than 12 weeks should be considered as candidates for surgery. Indications for surgery include intractable pain, spinal cord compression, and the need for stabilization of impending pathological fractures. Whereas various surgical approaches have been advocated, anterior-approach surgery is the most accepted procedure for spinal cord decompression. Posterior approaches have also been used with success, but they require longer-length fusion. To obtain a stable fixation, the placement of instrumentation, in conjunction with judicious use of polymethylmethacrylate augmentation, is crucial. Preoperative embolization should be considered in patients with extremely vascular tumors such as renal cell carcinoma. Vertebroplasty, a newly described procedure in which the metastatic spinal lesions are treated via a percutaneous approach, may be indicated in selected cases of intractable pain caused by non- or minimally fractured vertebrae.
Daipayan Guha, Robert F. Heary, and Mohammed F. Shamji
Decompression without fusion for degenerative lumbar stenosis is an effective treatment for both the pain and disability of neurogenic claudication. Iatrogenic instability following decompression may require further intervention to stabilize the spine. The authors review the incidence of postsurgical instability following lumbar decompression, and assess the impact of surgical technique as well as study design on the incidence of instability.
A comprehensive literature search was performed to identify surgical cohorts of patients with degenerative lumbar stenosis, with and without preexisting spondylolisthesis, who were treated with laminectomy or minimally invasive decompression without fusion. Data on patient characteristics, surgical indications and techniques, clinical and radiographic outcomes, and reoperation rates were collected and analyzed.
A systematic review of 24 studies involving 2496 patients was performed, assessing both open laminectomy and minimally invasive bilateral canal enlargement. Postoperative pain and functional outcomes were similar across the various studies, and postoperative radiographie instability was seen in 5.5% of patients. Instability was seen more frequently in patients with preexisting spondylolisthesis (12.6%) and in those treated with open laminectomy (12%). Reoperation for instability was required in 1.8% of all patients, and was higher for patients with preoperative spondylolisthesis (9.3%) and for those treated with open laminectomy (4.1%).
Instability following lumbar decompression is a common occurrence. This is particularly true if decompression alone is selected as a surgical approach in patients with established spondylolisthesis. This complication may occur less commonly with the use of minimally invasive techniques; however, larger prospective cohort studies are necessary to more thoroughly explore these findings.
Nitin Agarwal, Robert F. Heary, and Prateek Agarwal
Pedicle screw fixation is a technique widely used to treat conditions ranging from spine deformity to fracture stabilization. Pedicle screws have been used traditionally in the lumbar spine; however, they are now being used with increasing frequency in the thoracic spine as a more favorable alternative to hooks, wires, or cables. Although safety concerns, such as the incidence of adjacent-segment disease (ASD) after cervical and lumbar fusions, have been reported, such issues in the thoracic spine have yet to be addressed thoroughly. Here, the authors review the literature on ASD after thoracic pedicle screw fixation and report their own experience specifically involving the use of pedicle screws in the thoracic spine.
Select references from online databases, such as PubMed (provided by the US National Library of Medicine at the National Institutes of Health), were used to survey the literature concerning ASD after thoracic pedicle screw fixation. To include the authors’ experience at Rutgers New Jersey Medical School, a retrospective review of a prospectively maintained database was performed to determine the incidence of complications over a 13-year period in 123 consecutive adult patients who underwent thoracic pedicle screw fixation. Children, pregnant or lactating women, and prisoners were excluded from the review. By comparing preoperative and postoperative radiographic images, the occurrence of thoracic ASD and disease within the surgical construct was determined.
Definitive radiographic fusion was detected in 115 (93.5%) patients. Seven incidences of instrumentation failure and 8 lucencies surrounding the screws were observed. One patient was observed to have ASD of the thoracic spine. The mean follow-up duration was 50 months.
This long-term radiographic evaluation revealed the use of pedicle screws for thoracic fixation to be an effective stabilization modality. In particular, ASD seems to be less of a problem in the relatively immobile thoracic spine than in the more mobile cervical and lumbar spines.