Surgical treatment of patients with lumbar spinal stenosis with associated scoliosis.

Spinal stenosis in combination with scoliosis frequently is seen in elderly patients. Patients typically present with a combination of symptoms attributable to neurogenic claudication and radicular pain, and symptoms of lower back pain. For patients in whom conservative treatment is not sufficient, surgical treatment can be done with careful consideration of the overall patient and his or her medical status. Surgical treatment is twofold; one purpose is to decompress the neural elements, the other purpose is to stabilize and realign the spine to as great a degree as possible. Appropriate balance of the spine at the end of the procedure is more important than the absolute amount of correction obtained. Stabilization and correction of the spine is done with pedicle screw-rod instrumentation and fusion, and the procedure must be done in an efficient and timely manner to involve the least amount of morbidity. There are two types of deformity typically seen, one is a degenerative lumbar scoliosis with no or minimal rotational deformity (Type I), and the other is a degenerative scoliosis often superimposed on a preexisting scoliosis with greater rotational deformity and greater loss of lordosis (Type II). Instrumentation and correction techniques differ for these two types of deformities, with shorter instrumentation procedures usually possible for the Type I deformity and longer instrumentation with sagittal plane reconstitution necessary for Type II deformity.

Cervical deformity: rationale for selecting the appropriate fusion technique (anterior, posterior, and 360 degree).

This article examines cervical deformities and their treatments, such as iatrogenic deformities, posttraumatic deformities, ankylosing spondylitis, rheumatoid arthritis, degenerative subaxial spondylolisthesis, myopathy, infectious spondylitis, and tumors. Congenital scoliosis and kyphosis and torticollis and rotatory atlanto-axial subluxation also are discussed.

Thoracic and lumbar deformity: rationale for selecting the appropriate fusion technique (Anterior, posterior, and 360 degree).

The rationale of anterior versus posterior, or combined fusion is discussed with regards to different clinical diagnoses and situations. Factors involved in the decision-making process include stability, magnitude of deformity, rigidity of deformity, neurologic considerations, bone quality, and medical/metabolic factors. Careful preoperative assessment and planning are required as well as consideration for the patient's overall well being.

Interobserver variability in grading lumbar fusions.

Inter- and intraobserver variability in grading lumbar fusion status radiographically was assessed. The objective was to determine the interobserver variability and intraobserver reproducibility in the assessment of two level noninstrumented lumbar fusions. Fifty sets of radiographs with anteroposterior, left and right bending, and flexion-extension lateral views were assessed by six observers of varying experience and background, with fusion status graded. Kappa statistical analysis revealed only fair interobserver agreement in grading lumbar fusion status. Intraobserver reproducibility was higher in more experienced observers. The results indicate only fair reliability in terms of interobserver agreement to grading of lumbar fusion status. Variability in assessing lumbar fusion radiographically may explain some of the variability in fusion rates reported in the literature and poor correlation that can be seen between clinical outcome and radiologic outcome.

Reliability of roentgenogram evaluation of pedicle screw position.

STUDY DESIGN: This was a human cadaver study of the accuracy of biplanar roentgenography in determining pedicle screw position. OBJECTIVE: To determine the independent accuracy of radiologic evaluation of screw placement and to determine if there are any particular screw malpositions that are more likely to produce a false sense of acceptable screw position. SUMMARY OF BACKGROUND DATA: Other investigators have reported the correlation between radiologic evaluation and anatomic dissection. However, in those studies the radiologic evaluation was not independent of the surgeons placing the screws. There has been no comment in the literature regarding particular screw malpositions that would lead the surgeon into a false sense of successful screw placement. METHODS: Pedicle screws were placed in cadaver spines, and biplanar roentgenograms of the specimens were evaluated by independent observers. The results of the roantgenogram evaluation then were compared to those of the anatomic dissection. RESULTS: The accuracy of roentgenogram evaluation varied from 73% to 83%, depending on the experience of the surgeon grading the roentgenograms. Screws misplaced medially into the spinal canal are more likely to give the surgeon a false sense of successful screw placement. CONCLUSIONS: The surgeon must not rely solely on the roentgenograms, but instead continue to use tactile sensory skills, anatomic knowledge, and additional modalities such as electromyography monitoring.

Familial predisposition for degenerative disc disease. A case-control study.

STUDY DESIGN: This case-control study was undertaken to determine if relatives of patients who had been admitted for surgery for degenerative disc disease-related problems were at increased risk for lower back pain or sciatica. OBJECTIVES: To determine if familial factors play a role in placing a person at risk for development of degenerative disc disease of the lumbar spine. SUMMARY OF BACKGROUND DATA: It is known that smoking and various occupational factors can place a person at risk for degenerative disc disease problems. It is not known if a familial predisposition may also exist. METHODS: The family members and relatives of 65 patients who had undergone surgery for lumbar degenerative disc disease were interviewed with a standardized questionnaire and compared with a control group of 67 patients who had been admitted to hospital for non-spine-related orthopedic procedures. The same interview and standardized questionnaire was used for both groups by a single observer. RESULTS: In the study group of 65 patients who had undergone surgery for degenerative disc disease, 44.6% were noted to have a positive family history, whereas 25.4% of the patients in the control group had a positive family history. Eighteen and one-half percent of relatives in the study group had a history of having spinal surgery, compared with only 4.5% of the control group. CONCLUSIONS: The results indicate that a familial predisposition to degenerative disc disease can exist along with other risk factors.

Biomechanical comparison of the dewar and interspinous cervical spine fixation techniques.

STUDY DESIGN: This study evaluates and compares the stiffness of two cervical spine fixation techniques. OBJECTIVES: This biomechanical study was carried out to compare the interspinous and Dewar cervical spine fixation techniques. SUMMARY OF BACKGROUND DATA: Interspinous wiring is a commonly used method of fixation in the cervical spine. The Dewar technique is less commonly known and practiced, and clinical experience has suggested that it may be a more stable technique. METHODS: Cervical spine specimens stabilized with the interspinous and "Dewar" techniques were biomechanically tested in flexion and in torsion. Stiffness and energy absorption under moderate loads were compared. The Dewar technique uses contoured double corticocancellous iliac grafts as internal grafts/splints fixed to the spine with threaded pins and wire. The interspinous technique is a single interspinous wire loop. Eleven fresh human cervical spines were harvested from cadavers. The spines were destabilized at C4-C5 by sectioning all tissue except the anterior longitudinal ligament. Each fixation technique was applied alternatively and tested on each spine. RESULTS: In torsion testing (n = 5), the Dewar fusion was 61% stiffer than the interspinous technique (P < 0.02). Dewar: 11.3 N/mm (s.d. 4.9 N/mm) and interspinous: 8.4 N/mm (SD 3.3 N/mm). In flexion testing (n = 6), the Dewar technique was 35% stiffer than the interspinous technique (P < 0.10). Dewar: 655.4 Nmm/degree (SD 293 Nmm/degree) and interspinous: 406.8 Nmm/degree (SD 113.0 Nmm/degree). Energy absorption with the interspinous technique was greater in flexion (P < 0.10) and in torsion (P < 0.005), indicating more deformation with the interspinous technique. There was no statistically significant difference between the means of specimens tested first and those tested second independently of the fixation technique. CONCLUSIONS: These tests indicate that the Dewar cervical spine fixation is stiffer than the single interspinous wire in both flexion and particularly torsion. This project is the only biomechanical study of the Dewar technique that we are aware of, and the results support the clinical findings regarding the effectiveness of this technique.

Brown's procedure for congenital absence of the tibia revisited.

The results of reconstructive surgery in tibial hemimelia using a modified fibular transfer procedure as described by Brown were reviewed. A modified Brown's procedure was carried out on five patients with a total of seven affected limbs. A Syme's-type amputation of the foot was carried out in each case. All of the knees had quadriceps function preoperatively, which was considered a prerequisite for surgery. Average length of follow-up was 7 years, with a range of 2-12 years. The average age at time of surgery was 12.7 months, with a range of 7-26 months. At the time of review, all patients had reasonably good function of their lower extremities. All were ambulating with patellar tendon-bearing prostheses and thigh extensions for collateral support. The average arc of motion at review was 57.4 degrees, with further passive motion possible in all cases. Average extension was -18.5 degrees, and the average active flexion was 76 degrees. We found that a fibular centralization procedure in a patient with at least grade III+ quadriceps function can give good functional results that do not appear to deteriorate over time.

Results of intervertebral diskectomy without fusion at L4-5 versus L5-S1.

The results of diskectomy without fusion at L4-5 were compared with those at L5-S1. Strict indications for surgery had been applied to each group. Evaluation was carried out using the Oswestry Disability scale, as well as a modified Smiley-Webster scale, and a subjective improvement rating scale, as well as documenting work status, whether any future surgery was required, and other factors. Results were placed into categories based on these evaluation methods and were analyzed statistically. Average follow-up was 51 months with a minimum of 24 months. Overall excellent and good results occurred in 81% of patients in both groups. No difference in reoperation rate was detected between the two groups. Women were more likely to undergo a subsequent procedure, usually fusion. Equally satisfactory results can be obtained at L4-5 and L5-S1 if strict selection criteria are used.

Radiographic assessment for patients with low back pain.

Guidelines for radiographs of the lumbar spine are established. In general, radiographs are not believed to be necessary for a first episode of low back pain present for less than 7 weeks. Exceptions to this include various medical or physical findings, which are listed. In general, anteroposterior and lateral views only should be done initially. Indications for other views are discussed.

Magnetic resonance imaging. Use in patients with low back or radicular pain.

With the current emphasis on cost containment, it is important to order the single best diagnostic test when clinical uncertainties must be resolved. Magnetic resonance imaging is currently the optimal imaging modality to provide the maximum amount of information when evaluating patients with suspected spinal disorders. A comprehensive magnetic resonance imaging study is needed along with a subspecialty interpretation to provide the greatest amount of useful clinical information.

The results of surgical treatment for adult scoliosis.

This study was done to define and characterize those adult patients with scoliosis who will have problems of pain and/or progression leading to a surgical procedure and to review the results of these surgical procedures. The authors reviewed the cases of 49 adult patients who had undergone surgical treatment for scoliosis (average follow-up, 34 months; range, 24-140 months). The patients were categorized according to age, which allowed analysis of the data comparing age and the incidence and level of pain, age versus the degree of curvature, and age versus the incidence of progression. The relative incidence of pain and progression as indications for surgery were found to vary with respect to age. In the younger groups, progression was more often the indication for surgery than in the older groups. The younger groups also had larger curves than did the older groups, on average. The degree of pain was not found to correlate with the magnitude of the deformity. Surgical complications occurred in 20 patients; however, 14 of these were minor complications during the perioperative period, which did not result in any sequelae. Surgical treatment can be done with a relatively low serious complication rate and good results in terms of pain relief and reasonable correction of the deformity.

Capitellocondylar total elbow replacement in rheumatoid arthritis. Long-term results.

We evaluated the long-term results of 202 capitellocondylar total elbow replacements that had been performed, from July 1974 through June 1987, in 172 patients. The duration of follow-up averaged sixty-nine months (range, twenty-four to 178 months). At the most recent follow-up examination, use of a 100-point rating score demonstrated an improvement from an average preoperative score of 26 points (range, 2 to 50 points) to an average postoperative score of 91 points (range, 45 to 100 points). The most improvement occurred in the categories of relief of pain, functional status, and range of motion in all planes except extension. The improvements in these categories and in the roentgenographic appearance that were seen in the early postoperative period did not deteriorate with time. The average preoperative arc of motion at the elbow ranged from -37 degrees of extension to 118 degrees of flexion. The average postoperative arc of motion at the elbow ranged from -30 degrees of extension to 135 degrees of flexion. Supination improved from 45 degrees preoperatively to 64 degrees postoperatively; pronation improved from 56 degrees preoperatively to 72 degrees postoperatively. The roentgenograms showed a radiolucent line adjacent to eight humeral and nineteen ulnar components; most of the lines were incomplete and one millimeter wide or less. Revision of the prosthesis was necessary in three elbows (1.5 per cent) because of loosening without infection, and in three additional elbows because of dislocation of the prosthesis. Complications included deep infection in three elbows (1.5 per cent); problems related to the wound in fifteen (7 per cent); permanent, partial sensory ulnar-nerve palsy in five (2.5 per cent); permanent, partial motor ulnar-nerve palsy in one (0.5 per cent); and dislocation in seven (3.5 per cent).

Spinal stenosis with scoliosis.

A retrospective review was carried out on 40 patients who met the criteria of 1) having a significant lumbar scoliosis associated with spinal stenosis, with symptoms of neurogenic claudication; and 2) having been treated with posterior decompression and pedicular screw fixation techniques. The average age of the patients was 61.5 years (range, 38-77 years), and 25 of the 40 patients were female. Eighty-eight percent of the patients had significant back pain in addition to lower extremity pain. All patients had pedicular screw fixation at all levels. Zielke instrumentation was used in 24 patients, Cotrel-Dubousset instrumentation in 8 patients, and Texas Scottish Rite Hospital instrumentation in the remaining 8 patients. After surgery, there was marked improvement in regard to pain status: 34 patients (83%) had severe pain before surgery, with 38 patients (93%) reporting mild or no pain at follow-up. Average length of follow-up was 44 months (range, 24-61 months). There were no deaths and no instrument-related failures or pseudarthroses noted in this series. A mean correction of the deformity of 19 degrees was obtained. Average scoliosis was 37 degrees before surgery and 18 degrees at follow-up.

Acute tumor lysis syndrome after intrathecal methotrexate administration.

A 44-year-old man had acute tumor lysis syndrome after a single dose of intrathecal methotrexate was administered for lymphomatous meningitis (high-grade, small noncleaved B-cell) in the setting of untreated systemic disease. The metabolic derangements reversed completely with conservative therapy and did not recur with subsequent treatment. Intrathecal methotrexate administration results in potentially toxic systemic methotrexate levels which persist longer than an equivalent systemic dose. Active central nervous system lymphoma may increase the duration of toxic levels in the circulation and contribute to the peripheral effects of the drug. The pathogenesis of tumor lysis syndrome in this patient and the mechanisms of systemic toxicity of intrathecal methotrexate are discussed.

Age-related changes in the human femoral cortex.

Bone undergoes structural changes with aging, but the nature of qualitative changes remains to be established. Blocks of midshaft femur were taken at autopsy from men of four different age groups: 20-25 years, 40-45 years, 60-65 years, and 80-85 years. Each femoral specimen was analyzed by density fractionation, a technique that allows the separation of bone by extent of mineralization and maturity. In the 20-25 group, lower density bone predominates. The 40-45 group is characterized by more highly mineralized bone with an increase in the 2.1-2.2 g/cc fraction. At 60-65 years, an increase in the lower density fraction was found, indicating an increase in new bone formation. At 80-85 years, there is an increase in the highest density bone (2.2-2.3 g/cc), which may represent regions of interstitial bone not properly removed through remodeling processes. Chemical studies did not reveal any change in Ca, P, Ca + PO4, or Ca/P molar ratio with respect to age. X-ray diffraction studies show no changes in apatite crystal size with respect to age or degree of mineralization. Morphological studies documented increased remodeling activity and endosteal trabecularization in the older age groups, as well as increased intracortical porosity. An increase in the highest density fraction with aging may represent a pool of bone mineral that is less accessible to remodeling, which may be the interstitial bone.

The accuracy of tibial intramedullary alignment devices in total knee arthroplasty.

The accuracy of a tibial medullary alignment device is assessed radiographically in 30 varus and 30 valgus knees undergoing total knee arthroplasty. The results suggest that although the device is reliable and accurate for varus knees, it may lead to malalignment of up to 5 degrees in valgus knees. Overall neutral alignment was achieved in 83% of the varus knees and 37% of the valgus knees. Tibial bowing was the main source of error and was present in 66% of the valgus knees, with mean of 3 degrees. Preoperative long films or cross-checking with external alignment devices is recommended to assure neutral alignment in genu valgus deformity.

Interobserver variability in grading Perthes' disease.

Fifteen independent observers of three levels of experience (consultant staff, fellows, residents) assessed 40 radiographs of children presenting with Perthes' disease using the Catterall and the Salter-Thompson grading systems. Each observer was supplied with descriptions and illustrations of the classifications and each hip was grouped by both systems by each observer. The results were statistically analysed using 'kappa' statistics. The level of interobserver agreement was higher for the Salter-Thompson system and correlated with the level of experience of the observer. Both systems can give acceptable levels of interobserver agreement, but the Salter-Thompson grouping is simpler and easier to apply in the earlier stages of the disease when treatment must be decided, and has a higher degree of reproducibility amongst more experienced observers.