The effect of intraoperative blood loss on serum cefazolin level in patients undergoing instrumented spinal fusion. A prospective, controlled study.

STUDY DESIGN: This study is a prospective, controlled study of the effect of intraoperative and postoperative blood loss during spinal surgery on serum cefazolin level. OBJECTIVES: To determine what effect, if any, intraoperative blood loss has on serum antibiotic levels, and to determine if adjustment of the dose or dose interval is appropriate in operative cases of significant blood loss. SUMMARY OF BACKGROUND DATA: The problem of infection at the operative site after posterior spinal fusion with internal fixation is significant. It commonly has been accepted that blood loss results in a more rapid clearance of antibiotic. METHODS: Nineteen patients scheduled for elective spinal fusion with internal fixation were enrolled in this study. Each patient served as his or her own control. Baseline cefazolin clearance was determined the week before surgery. Cefazolin clearance again was determined intraoperatively. Blood loss was recorded throughout the procedure. RESULTS: The mean blood loss was 650 mL. There was no significant difference between preoperative and intraoperative cefazolin clearance, and there was no correlation between blood loss and cefazolin level. CONCLUSIONS: It is not necessary to give cefazolin at a dosing interval of less than 4 hours with blood losses of up to 1200 mL. This will maintain the antibiotic concentrations well above the minimum inhibitory concentration.

A study of the efficacy of nonoperative treatment of presumed traumatic spondylolysis in a young patient population.

The purpose of this study is to report the results of nonoperative treatment of presumed traumatic spondylolysis in a young patient population seen at the Walter Reed Army Medical Center Orthopaedic Surgery Spine Service from 1986 to 1994. A retrospective chart review analysis with recent follow-up was performed on 29 patients diagnosed through clinical examination and plain radiographs. Bone scan was reserved for those patients with an examination consistent with spondylolysis yet inconclusive plain films. All patients were treated with activity modification (to include a temporary profile for active duty military), full-time bracing (most commonly a thoracolumbosacral orthosis), and nonsteroidal anti-inflammatory drugs. Narcotic analgesics were added to this regimen, if indicated. There were 23 males and 6 females with an average age of 21 (range 13-31). There were 7 United States Military Academy cadets, 7 dependent children, 5 noncommissioned officers, 6 enlisted, and 4 officers. Of the 29 patients with spondylolysis, 20 had an L5 defect, 6 had an L4 defect, 4 had an L3 defect, and 1 had an L2 defect. Two of the 29 patients healed their spondylolysis, but the remainder failed nonoperative treatment. In the population of patients referred to our institution, spondylolysis is not a benign process. The literature suggests that the majority of these injuries heal, yet this has not been our experience. We propose that if the patient is diagnosed acutely with a fracture of the pars interarticularis and the aforementioned proven regimen is initiated, the chances for a successful nonoperative outcome are optimized.(ABSTRACT TRUNCATED AT 250 WORDS)

Total coccygectomy for the relief of coccygodynia: a retrospective review.

Nine of 10 patients operated on by a single surgeon were studied. Hospital records, radiographs, and a postal survey were used. Follow-up averaged 56 months. Age at operation averaged 32.5 years. There were six males and three females. Symptoms had been present for 7 months to 14 years and all patients failed a course of non-operative therapy. All patients underwent a total coccygectomy by subperiosteal dissection through a longitudinal midline incision. There was one postoperative wound infection. All patients were satisfied with the surgical scars. Three patients reported "complete" pain relief, five reported "marked improvement," and one was "slightly improved." All nine patients were satisfied with the operation and would choose to have the surgery again.

Lumbar and lumbosacral fusion using Steffee instrumentation.

Posterior and posterolateral spinal fusion with the Steffee variable plating system have been performed on 176 patients at Walter Reed Army Medical Center since November 1985. This report covers the authors' early experience using the Steffee device on 39 patients. All of the 39 patients (100%) were available for a minimum follow-up of 2 years. Complications occurred in 26% of the patients. Radiographic pseudarthrosis occurred in 8% of the patients. The findings suggest that lumbar and lumbosacral fusion supplemented with Steffee plate instrumentation are associated with a low incidence of pseudarthrosis and acceptable morbidity overall.

Magnetic resonance imaging of the brain stem in adolescent idiopathic scoliosis.

The cause of adolescent idiopathic scoliosis remains an enigma. Several studies have demonstrated abnormalities of posture, proprioception, and equilibrium control in patients with adolescent idiopathic scoliosis. These functions are integrated by structures in and around the brain stem. Twenty-seven patients with adolescent idiopathic scoliosis were studied with magnetic resonance imaging to delineate the anatomy of the brain stem in such patients. Imaging was conducted from the hypothalamus to the spinal cord at C3 in 26 patients; the remaining patient underwent an incomplete study because of a claustrophobic reaction. The study group consisted of 25 females and 2 males with an average age of 16 + 5 years. There were 19 right thoracic curves, 5 thoracolumbar curves, and 3 left lumbar curves. The mean primary curve size was 27 degrees at the most recent clinical evaluation. Seven patients were treated with observation, 14 with bracing, and 6 with surgery. The magnetic resonance imaging studies were read independently by three attending radiologists in a randomized, blinded fashion along with the magnetic resonance imaging studies of 11 controls. Asymmetry in the ventral pons or medulla in the area of the corticospinal tracts was noted in seven study patients and one control; one study patient had an enlarged cisterna magna and one an inconclusive (incomplete) study. These findings may support previous studies that have suggested a central nervous system abnormality as a cause of adolescent idiopathic scoliosis.

Osteoblastoma of the spine. A review of 75 cases.

Clinical and radiologic features of 75 cases of osteoblastoma of the spine were reviewed. In addition to pain, which was the most frequent complaint, 18 patients demonstrated objective neurologic deficit, while scoliosis was observed in 17 patients. Aspirin yielded pain relief in 13 patients. Pathologic fracture was not encountered. The radiologic and histologic characteristics of osteoblastoma of the spine are indistinguishable from those arising in other sites. The typical lesion exhibited a well-defined, geographic margin with a sclerotic, frequently lobulated border. Approximately one half of the cases were predominantly lucent, the remainder displaying varying degrees of matrix mineralization. Distribution of the osteoblastomas through the spinal axis was as follows: cervical-29, thoracic-16, lumbar-17, sacral-13. Other significant findings included posterior element involvement in 73 of 75 cases, and a striking male to female ratio of 2.5 to 1.

Microcomputer reconstruction for analysis of spinal deformity and lung volume in hypokyphotic scoliosis.

Current techniques for imaging chest deformity are limited to two-dimensional representations, and clinical testing for lung volume measurements are based on pulmonary function studies that are effort-dependent. The authors evaluated spine deformity and lung volume by using a new three-dimensional microcomputer imaging technique. Results from preoperative and postoperative chest computed tomograms underwent boundary detection by expert human observers. Data were then processed by polygon surface tiling to create three-dimensional color images of the spine and lungs for display. This computer technique allowed: 1) visualization of the anatomic relationships from any angle, 2) assessment of spinal deformity in relation to lung volume, and 3) measurement of individual lung volumes. Three-dimensional microcomputer imaging is a useful technique in objectively measuring lung volume and assessing postoperative changes.

Serum creatine kinase and lactate dehydrogenase changes after anterior approaches to the thoracic and lumbar spine.

Ten patients undergoing anterior approaches to the thoracic and lumbar spine had prospective determinations of serum creatine kinase, lactate dehydrogenase, and their myocardial-associated isoenzymes (CK-MB and the LD-1/LD-2 ratio). None of these patients experienced postoperative myocardial infarction. Skeletal muscle injury associated with anterior spinal surgery resulted in significant elevations of serum CK-MB on postoperative Day 1; however, the LD-1/LD-2 ratio did not change significantly. Although false-positive elevations of serum CK-MB occurred, no patient had a CK-MB value exceeding 50 IU/liter combined with an LD-1/LD-2 ratio exceeding 1.0 (so-called "flipped LD" pattern). In evaluating suspected postoperative myocardial infarction, the authors recommend determining the isoenzymes of both serum creatine kinase and lactate dehydrogenase. In postoperative patients, elevations of CK-MB exceeding 50 IU/liter combined with an LD-1/LD-2 ratio exceeding 1.0 should not be attributed to skeletal muscle injury alone after anterior approaches to the thoracic and lumbar spine.

Preoperative indium-labeled white blood cell scintigraphy in suspected osteomyelitis of the axial skeleton.

The cases of six patients with suspected osteomyelitis of the axial skeleton who underwent preoperative indium-labeled white blood cell scintigraphy (In-WBC) were reviewed retrospectively. Five of these patients had undergone previous spinal surgery, and all six patients complained of back pain. Four of these six patients were proven to have osteomyelitis by culture and histopathology. The sensitivity, specificity, and accuracy of In-WBC scintigraphy in detecting osteomyelitis of the axial skeleton was 25%, 50%, and 33%, respectively. Our preliminary experience in six patients with suspected osteomyelitis of the axial skeleton suggests that In-WBC scintigraphy is neither sensitive nor specific in predicting infection.

Nonoperative treatment of adult scoliosis.

The adult with idiopathic or degenerative scoliosis usually seeks treatment for relief of pain. Identifying the source of pain is crucial in formulating a plan of treatment. Nonoperative treatment is best suited to those adults with mild pain or elderly patients for whom surgery is not prudent. Analgesics, nonsteroidal anti-inflammatory drugs, orthoses, and activity modification are the mainstays of treatment.

Operative treatment of adult scoliosis with posterior fusion and instrumentation.

Adults with idiopathic or senescent scoliosis are a surgical challenge. Complaints of pain should be investigated to ascertain the exact cause in order for appropriate surgery to be performed. Complications associated with surgery in the adult are higher than with the adolescent, but can be minimized by a careful preoperative evaluation and meticulous surgical technique. Segmental spinal fixation using distraction and compression rods, sublaminar wires, and CD instrumentation are currently in use.

Adult idiopathic scoliosis treated by posterior spinal fusion and Harrington instrumentation.

Ninety-one patients with idiopathic scoliosis, who underwent posterior spinal fusion and instrumentation from January 1977 to December 1982, were reviewed. All patients were 20 years or older at the time of surgery and none had undergone a prior surgical procedure. Indications for surgery included pain, progressive deformity, and pulmonary symptoms. All patients had a posterior spinal fusion with Harrington instrumentation and autogenous iliac bone graft, with the addition of segmental wiring in only eight. No patient had an anterior fusion or fusion to the sacrum. Follow-up averaged 3.5 years (range: 2-7 years). The average correction at the time of surgery was 38%, and 32% at the time of last follow-up. Seventy-nine percent of the patients reported complete relief of the symptom(s) for which they had surgery. There were 34 complications in 30 (33%) patients. Pseudarthrosis occurred in 14 (15%), requiring 15 additional procedures to achieve a solid arthrodesis. Urinary tract infection occurred in 8 (9%) patients and Harrington hook dislodgement in 5 (5%). One patient sustained a partial paraparesis with recovery to a minimal deficit. No deaths occurred. Although largely successful, posterior fusion with Harrington instrumentation for adult scoliosis has a significant incidence of pseudarthrosis and instrumentation problems.

Determination of the Catterall classification in Legg-Calvé-Perthes disease.

Fifty hips in forty-four children with Legg-Calvé-Perthes disease, treated at the Shriners Hospital for Crippled Children, San Francisco, were evaluated with a simplified method of Catterall's classification. Our data indicate that the Catterall rating changed in 40 per cent of the hips when they were classified before they had reached the fragmentation stage of Waldenström compared with only 6 per cent when they were classified after fragmentation had occurred.