Pedicle screw placement using image guided techniques

Clinical evaluation of a computer assisted spine surgical system is presented. Eighty pedicle screws were inserted using computer assisted technology in thoracic and lumbar vertebrae for treatment of different types of disorders including fractures, spondylolisthesis, and scoliosis. Fifty-two patients with severe fractures, spondylolisthesis, or pseudoarthrosis of T10 to L5 were treated using a computer assisted technique on 1/2 the patients and performing the screw insertion manually for the other 1/2. At the same time, 28 pedicle screws were inserted in T12 to L4 vertebrae for scoliosis with the help of the computer assisted technique. Surgery was followed in all cases (66 vertebrae; 132 pedicle screws) by postoperative radiographs and computed tomographic examination, on which measurements of screw position relative to pedicle position could be done. For fractures, spondylolisthesis, or pseudarthrosis, comparison between the two groups showed that four screws in 52 (8%) vertebrae had incorrect placement with computer assisted technique whereas 22 screws in 52 (42%) vertebrae had incorrect placement with manual insertion. In patients with scoliosis, four screws in 28 (14%) vertebrae had incorrect placement. In all of the patients (132 pedicle screws) there were no neurologic complications. These results show that a computer assisted technique is much more accurate and safe than manual insertion.     

Spinal problems in mucopolysaccharidosis I (Hurler syndrome)

Bone-marrow transplantation has increased the survival of patients with mucopolysaccharidosis-I. We describe the spinal problems and their management in 12 patients with this disorder who have been followed up for a mean of 4.5 years since transplantation. High lumbar kyphosis was seen in ten patients which was associated with thoracic scoliosis in one. Isolated thoracic scoliosis was seen in another. One patient did not have any significant problems in the thoracic or lumbar spine but had odontoid hypoplasia, which was also seen in three other children. Four of the eight patients in whom MRI of the cervical spine had been performed had abnormal soft tissue around the tip of the odontoid. Neurological problems were seen in two patients. In one it was caused by cord compression in the lower dorsal spine 9.5 years after posterior spinal fusion for progressive kyphosis, and in the other by angular kyphosis with thecal indentation in the high thoracic spine associated with symptoms of spinal claudication.     

Sequential or simultaneous, same-day anterior decompression and posterior stabilization in the management of vertebral osteomyelitis of the lumbar spine

STUDY DESIGN: A retrospective clinical study of patients with vertebral osteomyelitis of the lumbar spine necessitating surgical treatment. All patients underwent sequential (same-day) or simultaneous anterior decompression and posterior stabilization of the involved vertebrae. OBJECTIVE: To evaluate the efficacy and clinical out-come of sequential or simultaneous anterior and posterior surgical approaches in the management of vertebral osteomyelitis of the lumbar spine. SUMMARY OF BACKGROUND DATA: Anterior approach alone and staged anterior decompression and posterior stabilization have been advocated as the surgical treatment methods of choice for patients with vertebral osteomyelitis of the lumbar spine. The drawbacks of the latter management plan are the necessity to use external support or the delayed patient mobilization and the need for additional anesthesia and surgical trauma. Sequential (same-day) anterior and posterior approaches are used regularly in the surgical management of scoliosis and other spinal deformities. It would appear advantageous to also use the same strategy (i.e., combined same-day double approaches) in the management of vertebral osteomyelitis of the lumbar spine. METHODS: Ten consecutive patients who had a diagnosis of vertebral osteomyelitis of the lumbar spine underwent combined (same-day) anterior and posterior approaches either in a sequential or simultaneous manner. Indications for surgery included neurologic deficit, abscess formation, instability with localized kyphosis formation, and failure of nonoperative treatment. Patients were evaluated clinically and radiographically after surgery. RESULTS: All 10 patients had uneventful surgery. Only one patient required a second surgical procedure because of expulsion of the anterior bone graft and pull-out of instrumentation. All patients were mobilized within the 2 days immediately after surgery. At the mean follow-up examination 30 months after surgery, all patients had regained their motor function and prior ambulatory status. CONCLUSIONS: Patients with lumbar osteomyelitis necessitating surgery can undergo combined, same-day surgery either in a sequential or simultaneous manner. This is a safe and efficient way to control the infection and stabilize the affected segments, allowing for early mobilization of these sick elderly patients.     

Revision of failed lumbar fusions. A comparison of anterior autograft and allograft

STUDY DESIGN: The radiographic and clinical results of two different anterior structural grafts were compared in 38 patients who had combined anterior-posterior revision surgery for failed lumbar fusion. OBJECTIVES: Failed lumbar fusion surgery, such as pseudarthrosis or flatback deformity, may result in disabling pain. The optimum revision technique has yet to be defined. The authors of the current study sought to determine which of two different types of anterior graft yields the best results. SUMMARY OF BACKGROUND DATA: Posterior procedures for revision of a failed lumbar fusion have not yielded reliably successful results. A combined anterior-posterior approach may be effective in restoring sagittal balance and enhancing fusion rates. Recent studies have shown femoral ring allografts to be effective in lumbar fusion revision, but no studies have compared these with other types of structural grafts. METHODS: Thirty-eight patients with pseudarthrosis were treated with combined anterior-posterior lumbar spine fusion using either femoral ring allografts (26 patients) or tricortical iliac autografts (12 patients). Radiographic follow-up examination and retrospective patient self-assessment questionnaires were used to evaluate outcomes. Results were assessed by independent reviewers after a mean follow-up period of 35 months. RESULTS: Radiographic follow-up examination revealed acceptably low pseudarthrosis rates for structural autografts (0%) and allografts (6%). The questionnaires revealed significant improvement in pain for both groups. Allograft patients showed greater improvement in function, less pain medication usage, and higher overall success rates (83%) than autograft patients (64%). CONCLUSIONS: Femoral ring allografts are as effective, clinically and radiographically, as tricortical iliac autografts when used as an anterior structural element in revision lumbar spine fusion in patients who have undergone multiple surgical procedures for pseudarthrosis or flatback deformity. The slightly greater improvement for the allograft group needs to be confirmed in a larger study.     

Spinal deformity in myelodysplasia. Correction with posterior pedicle screw instrumentation

STUDY DESIGN: A retrospective review of transpedicular instrumentation used in a series of 24 patients with myelodysplastic spinal deformities and deficient posterior elements. OBJECTIVE: To describe the usefulness and efficacy of these instruments in the treatment of complicated myelodysplastic spinal deformity. METHODS: The mean preoperative scoliosis was 75.7 degrees (range, 39-130 degrees) in the 22 patients with scoliotic deformities; 4 patients with thoracic hyperkyphoses averaged 70.5 degrees (range, 46-90 degrees) and 10 patients with lumbar kyphoses averaged 80.5 degrees (range, 42-120 degrees). The instrumentation extended to the sacrum in 4 patients and the pelvis in 9; 10 patients also underwent anterior release and fusion and 7 underwent concomitant spinal cord detethering. At an average follow-up of 4.0 years (2.0-7.7 years; one patient died at 8 months), all patients have fused (with the exception of two lumbosacral pseudarthroses). RESULTS: At last follow-up, deformity measured 32.1 degrees scoliosis (range, 6-85 degrees), 30.8 degrees thoracic kyphosis (range, 24-35 degrees), and 0.0 degree lumbar kyphosis (range, 35 degrees kyphosis to 29 degrees lordosis). Three patients lost some neurologic function after surgery; two recovered within 6 months and one has incomplete recovery. No ambulatory patient lost the ability to walk. Five patients required additional surgical procedures; in three cases, there was instrumentation breakage associated with pseudarthrosis or unfused spinal segments. CONCLUSIONS: Pedicle screw instrumentation is uniquely suited to the deficient myelodysplastic spine. Compared with historical control subjects, these devices have proven capable of significant correction of both scoliotic and kyphotic deformities. This instrumentation appears particularly useful in preserving lumbar lordosis in all patients and may preserve more lumbar motion in ambulatory myelodysplasia patients.     

Reversing the inhibitory effect of nicotine on spinal fusion using an osteoinductive protein extract

STUDY DESIGN: The effect on spinal fusion of an osteoinductive bone protein extract in the presence of a known inhibitor of spinal fusion (systemic nicotine) was studied prospectively in an animal model of posterolateral lumbar fusion. OBJECTIVES: To evaluate the ability of a bovine-derived osteoinductive bone protein extract to overcome the inhibitory effect of nicotine in a rabbit spine fusion model. SUMMARY OF BACKGROUND DATA: Multiple studies have demonstrated the ability of a variety of osteoinductive growth factors to serve as a bone graft substitute for lumbar spinal fusion under "normal" healing conditions. METHODS: Forty-eight adult female New Zealand white rabbits underwent spine arthrodesis at L5-L6 while receiving systemic nicotine through a subcutaneous miniosmotic pump. Arthrodesis was performed using one of the following three graft materials: 1) autogenous iliac crest, 2) osteoinductive bone protein delivered in an allogeneic demineralized bone matrix/ collagen carrier, or 3) osteoinductive bone protein delivered with autogenous iliac crest. Fusions were assessed by blinded manual palpation, radiography, and biomechanical testing. RESULTS: Of the 44 rabbits manually tested by blinded observers, all 14 in the osteoinductive bone protein plus autogenous iliac crest bone group had solid fusions (14 of 14), whereas the fusion rate was less in the osteoinductive bone protein plus demineralized bone matrix group (nine of 14, 64%; P = 0.02), and there were no fusions in the autogenous iliac crest only group (0 of 16, 0%; P = 0.000001). The use of osteoinductive bone protein with autogenous bone produced stronger and stiffer fusions compared with those using autogenous bone alone or osteoinductive bone protein with allograft bone. CONCLUSIONS: Cigarette smoking and nicotine are inhibitory factors in the healing of fractures and spine fusions. This study shows that the inhibitory effect of nicotine can be overcome with an osteoinductive bone growth factor in an animal model.     

A study of the diagnostic accuracy and reliability of the Scoliometer and Adam's forward bend test

STUDY DESIGN: Study of the diagnostic accuracy and interexaminer reliability of scoliosis diagnostic tests. OBJECTIVES: To estimate the sensitivity, specificity, and predictive value of the Scoliometer (National Scoliosis Foundation, Watertown, MA) and Adam's forward bend test in diagnosing scoliosis, and to determine the interexaminer reliability of the Scoliometer and Adam's forward bend test. SUMMARY OF BACKGROUND DATA: Exposure to diagnostic radiation in patients with adolescent idiopathic scoliosis may result in a small but significant increase in cancer rates. The full-spine radiographic examination remains the standard procedure for the assessment of scoliosis. There is a need for a valid and reliable noinvasive test to assess scoliosis. METHODS: Two examiners independently assessed 105 patients presenting to a scoliosis clinic for trunk asymmetry with Adam's forward bend test and axial trunk rotation with the Scoliometer. The Cobb method served as the gold standard. RESULTS: The interexaminer agreement for the Scoliometer is excellent in the thoracic spine and substantial in the lumbar spine. The interexaminer measurement error shows poor precision for thoracic and lumbar Scoliometer measurements. The interexaminer agreement for Adam's forward bend test is substantial in the thoracic spine and poor in the lumbar spine. Adam's forward bend test is more sensitive than the Scoliometer in detecting thoracic curves measuring 20 degrees or more by the Cobb method. Receiver operating characteristic curve analysis suggests that the use of the Scoliometer marginally improves the ability of diagnosing a scoliosis in the thoracic spine. CONCLUSIONS: The Scoliometer and Adam's forward bend tests have adequate interexaminer reliability for the assessment of thoracic curves. The Scoliometer has better interexaminer agreement in the lumbar spine. However, the Scoliometer has a high level of interexaminer measurement error that limits its use as an outcome instrument. Because Adam's forward bend test is more sensitive than the Scoliometer, the authors believe that it remains the best noninvasive clinical test to evaluate scoliosis.     

Transfusion management in pediatric and adolescent scoliosis surgery. Efficacy of autologous blood

STUDY DESIGN: A retrospective review of consecutive pediatric and adolescent patients who required posterior spinal fusion to correct scoliosis. OBJECTIVES: To 1) measure the participation of pediatric patients in predeposit programs for autologous and directed blood donation 2) to assess the success of autologous predonation in preventing allogeneic blood use, 3) to determine whether transfusion indications differed between patients who received allogeneic blood and those who received autologous blood, and 4) to assess factors that predict transfusion requirements during scoliosis surgery. SUMMARY OF BACKGROUND DATA: Authors of recent studies in adults have questioned whether transfusion of autologous blood is a cost-effective therapy when compared with the less-expensive alternative--transfusion of allogeneic blood. In children, the efficacy of autologous blood has not been assessed in a large population of surgical patients. In adults, the frequency of patient participation, the success of autologous donors in avoiding allogeneic transfusion, and the proportion of collected autologous units used during the perioperative period are measures used to establish the efficacy of autologous predonation programs. METHODS: Hospital and clinic records for each patient who underwent posterior spinal fusion from September 1, 1989 through September 1, 1994 were reviewed. Blood bank consultation, autologous donation records, anesthesia records, surgical reports, and hospital records were reviewed. Seventy percent of patients (164 of 243) participated in autologous donation. RESULTS: More than 90% of autologous donors successfully avoided receiving allogeneic blood. Patients with idiopathic scoliosis (n = 168) were more likely to participate in autologous donation (n = 144) and to avoid allogeneic blood (n = 135). Patients with neurologic causes of scoliosis more commonly used allogeneic or directed donation (56 of 75 patients). Nineteen patients with neuromuscular causes of scoliosis participated in autologous donation, but more than one half of this group (10 of 19 patients) required allogeneic blood in addition to autologous units. CONCLUSIONS: Using measures of efficacy similar to those reported in studies of adults, autologous blood was found to be more effective in meeting the transfusion needs of pediatric patients who required posterior spinal fusion than in meeting those needs in adult surgical patients in previous studies.     

Internal fixation of the thoracic and lumbar spine using Roy-Camille plates

Thirty patients underwent fixation of the thoracic and lumbar spine from 1986 to 1990 using the Roy-Camille pedicular screw fixation system. The spine was stabilized for a variety of pathologic entities including fracture, tumor, spondylolisthesis, postlaminectomy instability, and pseudarthrosis. All but one patient obtained solid fusion based on radiographic and clinical criteria with an average follow up of 19.5 months. All patients reported subjective improvement in preoperative pain levels. There were no neurologic complications associated with the surgical procedure. Roy-Camille plate fixation appears to offer a stable surgical construct in the treatment of thoracic and lumbar spine instability.     

New anterior instrumentation for the management of thoracolumbar and lumbar scoliosis. Application of the Kaneda two-rod system

STUDY DESIGN: The Kaneda multisegmental instrumentation is a new anterior two-rod system for the correction of thoracolumbar and lumbar spine deformities. This system consists of a vertebral plate and two vertebral screws for individual vertebral bodies and two semirigid rods to interconnect the vertebral screws. Clinical results of 25 thoracolumbar and lumbar scoliosis patients treated with this new instrumentation were analyzed. OBJECTIVES: To evaluate the efficacy of the new anterior instrumentation in correction and stabilization of thoracolumbar and lumbar scoliosis. SUMMARY OF BACKGROUND DATA: Since Dwyer first introduced the concept of anterior spinal instrumentation and fusion for scoliosis, anterior surgery has gradually gained acceptance. In 1976, a useful modification for the anterior spinal instrumentation, which reportedly provided means of lordosation and vertebral body derotation, was described. However, some authors reported a high tendency of the implant breakage, loss of correction, progression of the kyphosis, and pseudoarthrosis as the major complications. To overcome the disadvantages of Zielke instrumentation, the authors have developed a new anterior spinal instrumentation (two-rod system) for the management of thoracolumbar and lumbar scoliosis. METHODS: Anterior correction and fusion using Kaneda multisegmental instrumentation was performed in 25 patients with thoracolumbar or lumbar scoliosis. The average follow-up period was 3 years, 1 month (range, 2 years to 4 years, 7 months). There were 20 patients with idiopathic scoliosis (13 adolescents and seven adults) and five patients with other types of scoliosis, including congenital and other etiologies. All patients had correction of scoliosis by fusion within the major curve, and for 16 of the 25 patients, the most distal end vertebra was not included in the fusion (short fusion). Radiographic evaluations were performed to analyze frontal and sagittal alignments of the spine. RESULTS: The average correction rate of scoliosis was 83%. Over the instrumented levels, the correction rate was 90%. Preoperative kyphosis of the instrumented levels of 7 degrees was corrected to 9 degrees of lordosis. Sagittal lordosis of the lumbosacral area beneath the fused segments averaged 51 degrees before surgery and was reduced to 34 degrees after surgery. The trunk shift was improved from 25 mm before surgery to 4 mm at final follow-up evaluation. The average improvement in the lower end vertebra tilt-angle was 97% in those patients whose lower end vertebra was included in the fusion and 83% in patients whose lower end vertebra was not included in the fusion. Apical vertebral rotation showed an average correction rate of 86%. At final follow-up evaluation, all patients demonstrated solid fusion without implant-related complications. There was 1.5 degrees of frontal plane and 1.5 degrees of sagittal plane correction loss within the instrumented area at final follow-up evaluation. CONCLUSIONS: New anterior two-rod system showed excellent correction of the frontal curvature and sagittal alignment with extremely high correction capability of rotational deformities. Furthermore, correction of thoracolumbar kyphosis to physiologic lordosis was achieved. This system provides flexibility of the implant for smooth application to the deformed spine and overall rigidity to correct the deformity and maintain the fixation without a significant loss of correction or implant failure compared with conventional one-rod instrumentation systems in anterior scoliosis correction.     

Molecular genetics of alpha-L-fucosyltransferase genes (H, Se, Le, FUT4, FUT5 and FUT6)

The records of 1018 patients with low back pain in a tertiary spine referral practice were reviewed. One hundred thirty-nine out of 1018 (13.6%) underwent technetium-99m planar bone scanning as part of their investigation. Seventy-three out of 139 scans (52%) showed increased uptake in some area, but only 27 out of 139 (19.4%) showed increased uptake specifically in the low back. Scans consistently yielded no findings with reference to the back when the prescan diagnosis was spinal stenosis, lumbar pain syndrome, herniated nucleus pulposus, or postlaminectomy syndrome. Some scans gave positive findings in patients with a diagnosis of degenerative disc disease, pseudarthrosis, spondylolisthesis, fracture, infection, metabolic disorder, or tumor. Positive scans were generally obtained early after presentation (within 3 months) and negative scans obtained later (after 6 months), suggesting that clinical suspicion is still the main indication for early scanning. Planar bone scanning was helpful in both diagnosis and therapeutic decision-making in many conditions.     

The lordotic effect of the OSI frame on operative adolescent idiopathic scoliosis patients

STUDY DESIGN: A prospective evaluation of adolescent idiopathic scoliosis patients undergoing operative treatment on the Orthopedic Systems Incorporated (OSI; Jackson) frame. OBJECTIVES: To investigate prospectively thoracic, thoracolumbar, and lumbar sagittal alignments in patients with adolescent idiopathic scoliosis who undergo an instrumented posterior spinal fusion on the OSI frame. SUMMARY OF BACKGROUND DATA: In several studies, it has been shown that patient positioning on various operative frames is an important component of ultimate lumbar sagittal alignment. However, these studies have all concentrated on the lumbar spine, and no sagittal plane alignment data in adolescent idiopathic scoliosis patients have been reported in the thoracic and thoracolumbar junction as it relates to intraoperative positioning, correction maneuvers and correlative postoperative results. METHODS: Thirty-nine patients with operative adolescent idiopathic scoliosis treated with an instrumented posterior spinal fusion on the OSI frame were prospectively evaluated. Standing preoperative, intraoperative, and postoperative long-cassette lateral radiographs were reviewed with regional and segmental Cobb measurements of the thoracic, thoracolumbar junction, and lumbar spine obtained. RESULTS: Thoracic kyphosis (T1-T12) measured +34 degrees before surgery, +28 degrees during surgery, and +30 degrees after surgery, Thus, a statistically significant decrease was noted in thoracic kyphosis secondary to prone positioning on the OSI frame ( P < 0.05). Thoracolumbar spine measurements from T10 to L2 also showed a lordotic trend from +2 degrees before surgery, to -4 degrees during surgery, to -8 degrees after surgery, which was also statistically significant (P < 0.05). Total lumbar lordosis from T12 to S1 remained relatively unchanged from -60 degrees before surgery, to -59 degrees during surgery, to -60 degrees after surgery. However, segmental lumbar lordosis measured from T12 to the lowest instrumented vertebra showed a statistically significant increase in lordosis from -17 degrees before surgery, to -19 degrees during surgery, to -23 degrees after surgery (P < 0.05). Those patients in whom lumbar pedicle screws were used (vs. hooks alone) had the greatest increase in lumbar instrumented lordosis. CONCLUSIONS: Performing adolescent idiopathic scoliosis correction on the OSI frame tends to decrease thoracic kyphosis, increase thoracolumbar lordosis, and increase segmental instrumented lumbar lordosis, while it maintains total lumbar lordosis.     

Perioperative complications of anterior procedures on the spine

We reviewed the operative and hospital records of 447 patients in order to determine the rates of perioperative complications associated with an anterior procedure on the thoracic, thoracolumbar, or lumbar spine. The anterior procedures were performed to treat spinal deformity or for débridement or decompression of the spinal canal. The diagnostic groups that we studied included idiopathic scoliosis in adolescents or young adults (100 patients), scoliosis in mature adults (sixty-three patients), kyphosis (sixty-one patients), neuromuscular scoliosis (sixty patients), fracture (forty-seven patients), a revision procedure (thirty-nine patients), congenital scoliosis (thirty-six patients), tumor (nineteen patients), vertebral osteomyelitis or discitis (eight patients), and miscellaneous (fourteen patients). Complications occurred in 140 (31 per cent) of the 447 patients and were classified as major or minor. Forty-seven patients (11 per cent) had at least one major complication and 109 (24 per cent) had at least one minor complication. Two patients died, both from pulmonary complications after the operation. The most common type of major complication was pulmonary; the most common type of minor complication was genito-urinary. The adolescent or young adult patients who had idiopathic scoliosis had the lowest rate of complications, and the patients who had neuromuscular scoliosis had the highest. An age of more than sixty years at the time of the operation was associated with a higher risk of complications. The duration of the procedures involving a thoracic approach was shorter than that of those involving a thoracolumbar or lumbar approach; however, the rate of complications was not significantly different among the three approaches. Vertebrectomies took longer to perform and were associated with a greater estimated blood loss than discectomies; however, there was no significant difference in the rate of complications between the two types of procedures. The patients who had a fracture or a tumor lost more blood than those from the other diagnostic groups. Blood loss increased as the duration of the operation increased for all procedures. Combined anterior and posterior procedures performed during the same anesthesia session were associated with a higher rate of major complications than were procedures that were staged. A logistical regression analysis showed that the variables that increased the risk of a major complication were an estimated blood loss of more than 520 milliliters and an anterior and posterior procedure performed sequentially under the same anesthesia session. This analysis also demonstrated that the diagnosis of idiopathic scoliosis in adolescents or young adults was associated with a reduced risk of major complications. Compared with other major operations, an anterior procedure on the thoracic, thoracolumbar, or lumbar spine performed for the indications mentioned in this study is relatively safe.     

The fine structure of the parathyroid glands of rats with disuse osteoporosis

A series of 246 patients with scoliosis and attempted fusion had exploration performed six months later in order to detect and treat any pseudarthrosis at an early stage and so prevent subsequent loss of correction. Bilateral or unilateral pseudarthroses occurred in 25 per cent and were of three types--definite, hairline and doubtful. Single unilateral pseudarthroses accounted for 6 per cent and were of little if any clinical significance. The hairline pseudarthroses could not be seen radiologically and were easily missed at exploration. In general the pseudarthroses were least common in the more rigid parts of the spine and in curves which by nature of their aetiology or long duration had become most rigid. Neither the initial severity of the curve nor the degree of correction obtained before the initial attempted fusion had any apparent effect on the incidence. Follow-up for an average of four years has shown that a pseudarthrosis is of little significance with regard to the ultimate result provided it is recognised early and repaired.     

The correlation of idiopathic lumbar scoliosis and lumbar lordosis

A definite correlation exists between the presence of idiopathic lumbar scoliosis and hyperlordosis of the lumbar spine. Present data do not reveal whether hyperlordosis constitutes an element which makes a "spine at risk" for developing scoliosis. However, the presence of an extreme lordosis suggests that in any comprehensive plan of treatment of idiopathic lumbar scoliosis, provision should be made for correction of severe deformities of the lumbar spine.     

Review of 87 cases of scoliosis surgically treated

BACKGROUND: The authors compared the results and complications in surgical treatment of idiopathic scoliosis with Harrington's rod instrumentation with subtrasversal wires in dorsal treat. METHODS: A research on 87 cases operated on for idiopathic scoliosis from 1987 to 1995 is carried out. The 87 cases include 65 females and 25 males, 16 years old in average (range, 11 to 30). The curvature in Cobb's degrees and rotation of vertebrae with Raimondi's method on radiographs take just before, 15 days later and an year later on operation was measured. The patients have been divided into two groups: the first of 77 patients operated with Harrington's rod instrumentation; the second of 10 patients operated with Harrington's rod instrumentation and subtrasversal wires. RESULTS: In a general analysis without taking in to consideration the type and the seriousness of curvature it was obtained a better correction and derotation of vertebrae in patients of second group. The same group with wires had obtained a better correction and derotation of vertebrae in dorsal scoliosis from 40 degrees to 60 degrees and in the double scoliosis, while the first group obtained better results in dorsal scoliosis from 60 degrees to 80 degrees and in derotation of vertebrae on dorsal treat of double scoliosis. One case of pseudarthrosis in every group was observed. Any neurological complication were observed. CONCLUSIONS: The conclusions is drawn that the application of subtrasversal wire improves the Harrington's technique for the correction and derotation of dorsal and double scoliosis without neurological complications sometimes present with subliminar wires.     

Bisphosphonate risedronate prevents bone loss in women with artificial menopause due to chemotherapy of breast cancer: a double-blind, placebo-controlled study

PURPOSE: To determine the effectiveness and safety of the bisphosphonate risedronate in preventing bone loss in young women with breast cancer and early menopause induced by chemotherapy who are at major risk for the development of postmenopausal osteoporosis. PATIENTS AND METHODS: Fifty-three white women, aged 36 to 55 years, with breast cancer and artificially induced menopause were stratified according to prior tamoxifen use. Thirty-six patients received tamoxifen (20 mg/d). Within each stratum, patients were randomly assigned to receive risedronate (n = 27) or placebo (n = 26). Treatment consisted of eight cycles oral risedronate 30 mg/d or placebo daily for 2 weeks followed by 10 weeks of no drug (12 weeks per cycle). Patients were monitored for a third year without treatment. RESULTS: Main outcomes of the study were changes in lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle) bone mineral density (BMD), and biochemical markers of bone turnover. In contrast to a significant decrease of BMD at the lumbar spine and hip in the placebo group, there was an increase in BMD in the risedronate group. On treatment withdrawal, bone loss ensued, which suggests that treatment needs to be continuous to maintain a protective effect on bone mass. At 2 years, the mean difference (+/- SEM) between groups was 2.5% +/- 1.2%, (95% confidence interval [CI], 0.2 to 4.9) at the lumbar spine (P = .041) and 2.6% +/- 1.1%, (95% CI, 0.3 to 4.8) at the femoral neck (P = .029). Similar results were observed at the hip trochanter. Results by stratum indicate a beneficial, although partial, effect of tamoxifen in reducing bone loss. Risedronate was well tolerated and showed a good safety profile, with no evidence of laboratory abnormalities. CONCLUSION: Risedronate appears to be a safe treatment that prevents both trabecular and cortical bone loss in women with menopause induced by chemotherapy for breast cancer.     

Tri-calcium phosphate ceramics and allografts as bone substitutes for spinal fusion in idiopathic scoliosis as bone substitutes for spinal fusion in idiopathic scoliosis: comparative clinical results at four years

The authors present the results of a comparative study of two series of posterolateral arthrodeses for scoliosis performed using COTREL DUBOUSSET instrumentation. Fifty-four consecutive patients underwent surgery for idiopathic scoliosis using the same technique. Thirty received a graft consisting of a mixture of corticocancellous autologous and allogenic bone frozen at -80 degrees, and 24 patients were grafted with a mixture of cortico-cancellous autologous bone and sticks of tricalcium phosphate (TCP, Biosorb, SBM, Lourdes, France). All patients were seen at three, six and twelve months, then once a year for at least four years with clinical and radiological evaluation at each visit. At the final follow up visit, no radiologic signs of pseudoarthrosis were found in either group with a minimum follow-up of 4 years. The appearance of bone callus was considered satisfactory at 6 months in all cases; moreover callus seemed to be more important in the TCP series, although this assessment was subjective. TCP resorption was total after 2 years, while allograft fragments were visible on x-rays after 2 years. Minor mechanical complications occurred but did not influence the results. Loss of correction was 8% of that initially obtained in the allograft group and 2% in the TCP group. Loss of correction did not progress after 6 months in the TCP group and after 2 years in the allograft group. Based upon this experience, the use of synthetic bone substitutes such as TCP would appear to be a valuable alternative to allografts in posterolateral spinal arthrodesis for idiopathic scoliosis, and it would eliminate the risk of viral contamination inherent to allograft implantation. To our knowledge, there have been no previous comparative studies concerning the use of tricalcium phosphate versus allograft in the literature.     

Peripheral osteopenia in adult patients with insulin-dependent diabetes mellitus

Alterations in bone metabolism in diabetes mellitus is a topic of special interest. Bone blood flow is increased in the distal limb of diabetic patients, which is believed to increase osteoclastic activity. We measure bone mineral density using dual-photon absorptiometry in the distal lower limb, the femoral neck, and the lumbar spine in 41 IDDM patients and in 30 control persons. In the diabetic group there was a 10% reduction of bone mineral density in the femoral neck (p < 0.01) and a 12% reduction in the distal limb (p < 0.001) compared with the control group. No significant difference was found in the lumbar spine (p = 0.22). Our data yield incidence for peripheral osteopenia in IDDM-patients, independent of any systemic bone disease such as osteoporosis. A link between decreased bone mineral density and diabetic neuropathy has been observed for the femoral neck (p < 0.001), but not for the distal limb or axial skeleton. Whether there is a common aetiological link or a casual connection between diabetic neuropathy and bone mineral density has still to be determined.     

Cotrel-Dubousset instrumentation. Results in 52 patients

Fifty-two posterior spinal fusions were performed for pediatric idiopathic, congenital, and neuromuscular scoliotic curves. Cotrel-Dubousset instrumentation was used in all patients. Nine had prior anterior spinal releases and fusions. The patterns were mixed, with a predominance of right thoracic curvatures. The average preoperative curve measured 60.6 degrees, with correction to 29. Seven patients required revision surgery, and 17 wore orthoses after operation. There were 17 complications in this group, including hook pullout, prominent hardware, infection, pseudarthrosis, and two cases of broken Cotrel-Dubousset instrumentation rods. Fatigue failure of this instrumentation, secondary to pseudarthrosis, has not been reported previously, and these two cases are presented in detail. The operative morbidity and difficulty were increased in the larger idiopathic curves and in neuromuscular and congenital scoliosis. Cotrel-Dubousset instrumentation is an overall excellent tool for the multiplanar correction of scoliosis and is amenable to revision surgery.