Sagittal plane configuration of the sacrum in spondylolisthesis.

STUDY DESIGN: A radiographic study of the sagittal sacral deformity in spondylolisthesis. OBJECTIVES: To characterize and classify the pathoanatomy of sagittal sacral deformation in spondylolisthesis. SUMMARY OF BACKGROUND DATA: Spondylolisthesis has been extensively described and reviewed in the literature. Deformity of the entire sacrum in spondylolisthesis potentially could affect the natural history, treatment options, and outcome. The sagittal contour of the entire human sacrum has never been quantitatively studied in spondylolisthesis. METHODS: A literature search was performed and data was gathered retrospectively on patients with spondylolisthesis at the authors' institution. Cases of degenerative spondylolisthesis were excluded. Specifically those patients with L5-S1 spondylolisthesis were studied. The authors studied standing lateral radiographs and performed statistical analysis to understand morphologic relations. RESULTS: A broad range of global sacral kyphosis (37-188 degrees ) exists in spondylolisthesis. Increasing sacral kyphosis is significantly associated with increasing percent slip, sacral horizontal angle, Neuman's classification, lumbar lordosis, and lumbar index. A simple classification of the spectrum of sacral deformity in the sagittal plane is presented. CONCLUSION: The entire sacrum in spondylolisthesis can develop a significant kyphotic deformity in the sagittal plane, and this is associated with other abnormalities found in the lumbosacral spine. Sacral deformity is a significant factor in the assessment of the sagittal contour of the patient with L5-S1 spondylolisthesis.

An open, minimally invasive approach to the lumbar spine.

A minimum 2-year follow-up retrospective review was undertaken to assess our experience with an anterior paramedian muscle-sparing approach to the lumbar spine for anterior spinal fusion (ASF). The records of 28 patients (November 1991 through January 1996) undergoing ASF via a left lower quadrant transverse skin incision (6-10 cm) with a paramedian anterior rectus fascial Z-plasty retroperitoneal approach were reviewed. Diagnosis, number, and level of lumbar interspaces fused, types of fusion, estimated blood loss, length of procedure, length of hospital stay, and complications were analyzed. All cases were completed as either a same-day anterior/posterior (24 of 28) or as a staged procedure at least 1 week after posterior fusion (4 of 28). The General Surgery service performed the muscle-sparing approach, whereas the Orthopedic Spine service performed the ASF. There were 14 men and 14 women, with a mean age of 35.5 years (range, 11-52 years). Diagnoses included spondylolisthesis in 20 cases (including four grade III or IV slips), segmental instability (degenerative or postsurgical) in 7, and 1 flatback deformity. A single level was fused in 20 cases (L4/5 in 4 and L5/S1 in 16), two levels were fused in 5 cases (L4/5 and L5/S1) and three levels were fused in 2 cases (L3/4, L4/5, and L5/S1). The mean length of stay was 7.4 days (range, 5-12 days). The mean estimated blood loss was 300 mL for the anterior procedure alone and 700 ml for both anterior/posterior procedures on the same day. The mean length of operating room time for the anterior approach and fusion was 117 minutes (range, 60-330 minutes). Posterior instrumentation was used in all cases. Anterior interbody struts used included 19 autogenous tricortical grafts, 4 fresh-frozen allografts (2 femoral rings and 2 iliac crests), 3 carbon fiber cages packed with autogenous bone, and a Harms titanium cage with autograft. There was one L5 corpectomy for which a large tricortical allograft strut was utilized. There were no vascular, visceral, or urinary tract injuries. In three cases a mild ileus developed, which resolved spontaneously. We conclude that the anterior paramedian muscle-sparing retroperitoneal approach is safe, uses a small skin incision, avoids cutting abdominal wall musculature, and allows for multiple-level anterior spinal fusions by a variety of interbody fusion techniques. This approach does not require transperitoneal violation or added endoscopic instrumentation, nor does it limit fusion level and technique of fusion, as is the case with the recently popularized laparoscopic approach to the lumbar spine.

Semirigid instrumentation in the management of lumbar spinal conditions combined with circumferential fusion. A multicenter study.

STUDY DESIGN: Patients with the diagnosis of degenerative disc conditions or spondylolisthesis undergoing circumferential fusion with posterior pedicle screw fixation using a semirigid rod were reviewed. OBJECTIVES: To determine the effectiveness of this approach in achieving a spinal fusion and satisfactory clinical outcome, and to determine the complications associated with the procedure. SUMMARY OF BACKGROUND DATA: The use of instrumentation to stabilize the lumbar motion segments and thereby enhance the fusion rate has been proposed in a number of studies. Semirigid fixation was believed to be effective in achieving these objectives without concern for stress-shielding, which was suggested by some authors using rigid fixation systems. METHODS: Patients who required spinal fusion with anterior and posterior approaches because of specific lumbar pathology or previous surgeries were selected. The surgery consisted of an anterior interbody fusion using allograft, followed by a posterolateral fusion and pedicle screw fixation. Fusion was determined by continuity of trabecular bridging, and outcomes were determined by pain reduction and return to previous levels of activity. Fusion was considered solid if the two posterolateral areas were fused (Zones one and two), if the anterior interbody area was fused (Zone three), or if all three zones were fused. Complications were documented during and after surgery. RESULTS: Sixty-two percent of patients had previous surgery with 25% of these patients having a diagnosis of pseudarthrosis. Fifty-five percent of patients had two or more levels fused, and 43% were heavy smokers. Ninety-seven percent of patients had successful fusions. Pain was significantly reduced on a pain analogue scale from 7.1 to 2.1 in the back and from 5.8 to 1.5 in the leg (p < 0.006 and 0.0001, respectively). Fifty-nine percent of patients returned to their previous level of activity, and 18% returned to lighter work or job retraining, for a total of 77% returning to the same or lighter levels of activity. Complications included metal failure, 4.9%; neurologic deficit, 1.2%; deep infection, 1.2%; deep venous thrombosis, 4.9%; and vascular injury, 2.4%. Fatal pulmonary embolus occurred in one patient. CONCLUSION: This technique produces a satisfactory fusion rate (97%) and a good clinical outcome based on pain reduction and return to a satisfactory level of activity (77%). It is associated with few, but significant, complications that compare well with other reported series in a difficult group of patients. This procedure should be reserved for patients who are considered to be at high risk for not achieving spinal fusion.

Scoliosis in Rett syndrome.

Scoliosis is the most common orthopaedic problem encountered in Rett syndrome. It is characterized by a long C-shaped thoracolumbar curve of neurologic origin. The occurrence of scoliosis in Rett syndrome is age-dependent, with a reported incidence of 36% to 100%. The onset of scoliosis is usually before age 8 years, and rapid curve progression is usually detected early in the second decade. In Rett syndrome, sagittal deformity with excessive kyphosis can progress and necessitates close observation. Orthotic treatment does not alter the natural history of scoliosis or kyphosis. Indications for surgery are curve progression exceeding a 40 degree or 45 degree Cobb angle or curves that cause pain or loss of function. Anterior discectomy, interbody fusion, and posterior fusion with instrumentation can achieve improved correction in young adolescents with significant curves. Surgical intervention should include fusing the scoliotic and the excessively kyphotic segments.

Surgical treatment of metastatic spine disease.

The results of surgical intervention for metastatic disease on 56 consecutive patients since 1980 were reviewed. Two patients underwent a second procedure to stabilize remote levels of spinal involvement, for a total of 58 surgeries. All 56 patients presented with pain. After surgery, significant relief was noted by 51 (91%). Twenty-seven patients presented with neurologic compromise. After operation, neurologic improvement was noted in 20 (74%). No patient's neurologic function deteriorated secondary to surgical intervention. Twenty-one patients were bedridden before surgery secondary to pain or paresis. After operation, improvement in activity level was achieved in 16 (76%) of these patients. In summary, the goal of surgical treatment of metastatic spine disease is to improve the quality of the remaining life, by the relief of pain and preservation or restoration of neurologic function. The dismal consequences of prolonged bed rest, paraplegia, and a painful premature demise can be avoided with thoughtful and timely surgical intervention.

The Luque trolley revisited. Review of nine cases requiring revision.

This study is a retrospective review of nine patients who underwent Luque instrumentation without fusion from 1982-1984. Average age at surgery was 9 years. Average preoperative curve was 51 degrees (30 degrees-70 degrees). All nine patients have had at least one revision. All of the revisions were technically difficult secondary to extensive fibrosis and weakened laminar bone. Spontaneous fusion was documented in all nine patients, limiting further correction. Final follow-up curves averaged 51 degrees (25 degrees-90 degrees). Average gain in spinal height was 5.8 cm (2.3 in) but only a small portion was derived from the instrumented levels. Segmental spinal instrumentation without fusion in immature patients was not effective in control of spinal deformity, nor did it allow anticipated growth under the instrumented regions.

An evaluation of spinal deformity in metastatic breast cancer.

Between October 1984 and January 1988 31 magnetic resonance (MR) imaging studies were performed on 27 patients with metastatic vertebral breast cancer (MVBC). The MR images were reviewed to determine the extent and type of sagittal spinal deformity, and whether spinal canal compromise was present. Adjunct studies were compared to determine the pathogenesis of spinal deformity and the etiology of spinal canal compromise. An analysis of the data revealed that a consistent pattern of sagittal spinal deformity exists with MVBC, and a classification system was developed to describe the stages of vertebral deformity. Criteria are suggested for identifying metastatic spinal instability. A protocol is presented for treating patients with metastatic spinal involvement. By understanding the natural history of metastatic spinal deformity, instability and spinal canal compromise can be recognized and treated early, before the onset of progressive deformity and neurologic sequelae.

The pattern of vertebral involvement in metastatic vertebral breast cancer.

The spine is a common site of bony metastasis. To date, studies have not identified the initial site and pattern of vertebral metastasis in a homogeneous group of patients. Twenty-seven magnetic resonance imaging studies performed on 25 patients with metastatic vertebral breast cancer were reviewed retrospectively. The location and extent of metastatic vertebral involvement were determined. The vertebral body is the most frequent initial site of metastatic seeding. Although radiographically an absent pedicle is often the first sign of metastatic disease, involvement of the pedicle is by direct extension from either the vertebral body or the posterior elements and is therefore a late occurrence in the disease process.

Zielke instrumentation.

Zielke modified Dwyer's anterior spinal instrumentation to produce the Ventral Derotational Spondylodesis (VDS) System. The primary indication for VDS instrumentation is the treatment of progressive, single, major lumbar or thoracolumbar curves in idiopathic scoliosis. The surgical technique, including selection of appropriate curvatures and levels of instrumentation, is described. A group of 25 consecutive patients undergoing VDS instrumentation for lumbar or thoracolumbar curvatures was reviewed. The average correction of the major curve was 76%. The minor curvature was corrected with an average of 47%. A significant complication was a 20% incidence of pseudarthrosis and rod breakage. The implications of these problems are discussed. Zielke instrumentation is a powerful technique for the correction of selected curves. The system provides greater correction of the major curve, improved frontal and sagittal alignment, and preservation of distal motion segments.

The role of prophylactic surgery in the management of metastatic hip disease.

The surgical stabilization of pathological fractures has been advocated as early as 1953 as the best form of management for this difficult problem. The treatment of impending fractures has also been advocated, although the advantages of this form of treatment has not been clearly demonstrated in the literature. A consecutive series of 99 hips treated for a pathological fracture or an impending fracture of the hip were retrospectively reviewed. The patients treated prophylactically for an impending fracture had fewer complications, a löwer postoperative mortality rate, a lesser incidence of failure of stabilization, and a greater percentage of postoperative ambulators. Survival was not improved by prophylactic surgery. Adjunctive methyl methacrylate improved fixation and decreased the incidence of failure of stabilization of both impending and pathological fractures.