Translaminar screw fixation of the lumbar and lumbosacral spine. A 5-year follow-up

STUDY DESIGN: In a retrospective study, the long-term results of translaminar facet screw fixation of the lumbar and lumbosacral spine are reviewed. OBJECTIVES: To evaluate the clinical results, fusion rates and complications of this posterior fusion technique in various conditions of the lumbar spine. SUMMARY OF BACKGROUND DATA: Posterior fusion of the lumbar and lumbosacral spine is one of the possible methods to relieve pain and eliminate instability in degenerative conditions. Data in the literature support the use of internal fixation to optimize the rate of fusion. METHODS: Posterior lumbar and lumbosacral fixation with translaminar screws and fusion in 173 patients with degenerative changes with or without compressive syndromes including failed back syndromes, monosegmental hypermobilities, and posttraumatic conditions were investigated. Fixation and fusion with translaminar screws was performed in 57% monosegmentally, in 40% across two segments and in 2% over three segments. Decompressive surgery was performed in addition in 52% and nucleotomy in 30% of the cases. Clinical and radiologic assessment with flexion/extension x-rays was performed in 145 (83%) patients by two independent orthopedic surgeons. After an average follow-up of 68 months (range, 52-83). RESULTS: Ninety-four percent of the patients showed solid bony fusion in the radiologic follow-up. Loosening of the screws was noted in 3%, and two screws were broken without apparent motion on the functional x-rays. Pain scores decreased from 7.6 before surgery to 2.9 after surgery on a 10-point pain scale. The results were further analyzed according to Stauffer and Coventry with 99 good results, 70 satisfactory results, and 4 bad results. CONCLUSIONS: Translaminar screw fixation offers an immediate postoperative stability of the lumbar and lumbosacral spine and enhances fusion. In the present series no neurologic complications were noted. It represents a useful and inexpensive technique for short segment fusion of the nontraumatic lumbar and lumbosacral spine.     

Posterior C1-C2 transarticular screw fixation for atlantoaxial arthrodesis

OBJECTIVE: To assess the outcomes associated with C1-C2 transarticular screw fixation. METHODS: The clinical outcomes of 121 patients treated with posterior C1-C2 transarticular screws and wired posterior C1-C2 autologous bone struts were evaluated prospectively. Atlantoaxial instability was caused by rheumatoid arthritis in 48 patients, C1 or C2 fractures in 45, transverse ligament disruption in 11, os odontoideum in 9, tumors in 6, and infection in 2. RESULTS: Altogether, 226 screws were placed under lateral fluoroscopic guidance. Bilateral C1-C2 screws were placed in 105 patients; each of 16 patients had only one screw placed because of an anomalous vertebral artery (n = 13) or other pathological abnormality. Postoperatively, each patient underwent radiography and computed tomography to assess the position of the screw and healing. Most screws (221 screws, 98%) were positioned satisfactorily. Five screws were malpositioned (2%), but none were associated with clinical sequelae. Four malpositioned screws were reoperated on (one was repositioned, and three were removed). No patients had neurological complications, strokes, or transient ischemic attacks. Long-term follow-up (mean, 22 mo) of 114 patients demonstrated a 98% fusion rate. Two nonunions (2%) required occipitocervical fixation. In comparison, our C1-C2 fixations with wires and autograft (n = 74) had an 86% union rate. CONCLUSION: Rigidly fixating C1-C2 instability with transarticular screws was associated with a significantly higher fusion rate than that achieved using wired grafts alone. The risk of screw malpositioning and catastrophic vascular or neural injury is small and can be minimized by assessing the position of the foramen transversaria on preoperative computed tomographic scans and by using intraoperative fluoroscopy and frameless stereotaxy to guide the screw trajectory.     

A biomechanical comparison of intramedullary nail and crossed lag screw fixation for tibiotalocalcaneal arthrodesis

A series of Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (4a-p) was prepared by a simple synthetic procedure based on the reaction of hydroxylamine or methoxyamine with 2,3-substituted ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (3a-p). The antimicrobial activity of the obtained compounds was evaluated on a series of standard strains of Gram positive, Gram negative bacteria and fungi. None of the tested compounds showed significant activity.     

Carbonated apatite cement augmentation of pedicle screw fixation in the lumbar spine

STUDY DESIGN: Biomechanical testing with human cadaveric lumbar vertebral bodies was used to determine the utility of an injectable carbonated apatite cancellous bone cement for improving the structural performance of pedicle screws subjected to axial pull-out or transverse cyclic loading. OBJECTIVES: To ascertain whether augmentation with a carbonated apatite cement can enhance pedicle screw fixation in the lumbar spine. SUMMARY OF BACKGROUND DATA: The beneficial effects of polymethylmethacrylate augmentation on pedicle screw pull-out strength have been demonstrated. Cancellous bone cement, however, may provide an attractive alternative in this application, as it is remodelable, biocompatible, and nonexothermic. METHODS: Forty-three cadaveric lumbar vertebral bodies were instrumented with pedicle screws. In 20 of these specimens, axial pull-out strength was compared between the control screws and those augmented with cancellous bone cement. In the remaining 23 specimens, the screws were loaded in the superior-inferior direction with a peak displacement of +/- 1 mm at a frequency of 3 Hz for 5000 cycles. Three parameters were calculated from the force-versus-time data: 1) the energy dissipated, 2) the peak force at the start of the test, and 3) the peak force at the end of 5000 cycles. RESULTS: The pull-out strength of the augmented pedicles averaged 68% greater than that of the control side. In response to cyclic loading, all measures of bio-mechanical performance improved 30-63%. CONCLUSIONS: The data suggest that augmentation with this carbonated apatite cancellous bone cement can enhance immediate screw fixation.     

Pedicle instrumentation in the thoracic spine. A morphometric and cadaveric study for placement of screws

The aim of this study was to examine the possible effects of local application of a potent immunosuppressive drug, cyclosporin A (CsA), on fibroblast proliferation in vitro. Rabbit subconjunctival fibroblasts were cultured and incubated with varying doses of CsA (from 0.5 to 5%). Growth inhibition curves were obtained, and cell attachment and reversibility of drug-induced growth inhibition were studied. None of the doses stimulated fibroblast proliferation. CsA inhibited fibroblast proliferation depending on the dose and duration of application. Also, drug-induced growth inhibition decreased depending on dose and duration of application. While the dosage which led to 50% inhibition was found to be 7.2 mg/ml, 4% and higher doses had toxic effects.     

CT-guided interventional procedures for pain management in the lumbosacral spine

The lumbosacral spine is the source of pain, suffering, and disability more frequently than any other part of the body. Pain in the lower back can be managed with computed tomography-guided analgesic interventional procedures, such as periradicular infiltration, percutaneous laser disk decompression, facet joint block, and percutaneous vertebroplasty. Periradicular injection of steroids provides short-term and sometimes even long-term relief of low back pain. Percutaneous laser disk decompression is used to treat radiculalgia caused by disk herniation. Facet joint block is useful in diagnosis and treatment of facet syndrome. Percutaneous vertebroplasty provides short- and long-term pain relief in patients with vertebral body disease. However, precise patient selection is essential to the success of each of these techniques. The interventional radiologist has an active role to play in minimally invasive management of lower back pain and should be part of an interdisciplinary team that determines the appropriate therapy.     

Ankle arthrodesis with cross screw fixation. Good results in 36/40 cases followed 3-7 years

From May 1991 to May 1994, Lyme borreliosis was studied prospectively in 301 residents living on Asp?, a highly endemic area for the disease. The study included annual questionnaires and blood samples for serology. Immunoglobulin G (IgG) antibodies to Borrelia burgdorferi sensu lato were detected by enzyme-linked immunosorbent assay in 63/301 (21%) of the residents at the start of the study. Seropositivity rates increased with time, and 3 years later 101/301 (34%) were positive. A total of 34 individuals developed physician-verified manifestations of Lyme borreliosis during the study period. Nine individuals developed an erythema migrans, despite a previously treated Lyme borreliosis or pre-existing high levels of IgG antibodies to B. burgdorferi s.l.     

Observer variation in plain radiography of the lumbosacral spine

In this study, interobserver and intraobserver variations in the interpretation of plain radiographs of the lumbosacral spine were evaluated. Three radiologists independently interpreted the radiographs from 200 consecutive outpatients, aged 13-93 years, mostly referred from general practitioners. Interobserver agreement was best for vertebral fractures, osteopenia, spondylolisthesis at L5-S1, lumbosacral junctional vertebra, reduced disc height at L4-S1 and osteophytes at L2-S1 (kappa 0.61-0.95), and poorest for spina bifida of S1, degenerative spondylolisthesis and facet joint arthrosis at T12-L4, sacroiliac joint arthrosis, narrow central spinal canal, film quality, and for decisions concerning evaluation of facet joints and spinal canal (kappa < 0.34). For several diagnoses, the number of abnormal findings differed significantly between observers (p < 0.05, McNemar's test), indicating different diagnostic thresholds. Intraobserver agreement in 36 reevaluated patients was fair to excellent for almost all variables (kappa > 0.46). Although some diagnoses related to low back pain were quite consistently evaluated, the substantial disagreement on many findings should alert clinicians and radiologists against overestimating the validity and usefulness of the examinations. To improve diagnostic consistency, it is important to reduce variation caused by different thresholds for abnormality.     

Kinematic analysis of posterolateral fusion in the lumbosacral spine

Three cases operated upon with posterolateral fusion in the lumbosacral spine have been subjected to a kinematic postoperative analysis with the aid of a roentgen stereophotogrammetric method. The primarily diseased intervals became comparatively rigid in spite of significant residual mobility, in two of the patients, not until 174 days postoperatively. Three levels of operation displayed unrestricted residual mobility.     

Osteoplastic fixation of the spine

The combined anterolateral osteoplastic fixation of the spine was carried out on 17 cases out of 73 operated upon for pathological spinal changes of various etiology. The tibial crest rigid homograft and the rib autograft on vasoneuromuscular feeding pedicle were used. Such a combination of bone grafts possessing different mechanic and osteogenic properties permitted to obtain a reliable fixation of the spine for all the period necessary for anatomic and functional reconstruction of the grafts.     

Safety and accuracy of transarticular screw fixation C1-C2 using an aiming device. An anatomic study

STUDY DESIGN: In this anatomic study, the safety and accuracy of C1-C2 transarticular screw placement was tested in a normal anatomic situation in cadaver specimens using a specially designed aiming device. OBJECTIVES: To assess the safety and accuracy of transarticular screw placement using the technique described by Magerl and a specially designed aiming device. SUMMARY OF BACKGROUND DATA: Transarticular C1-C2 screw fixation has been shown to be biomechanically superior to posterior C1-C2 wiring techniques. Several clinical series have been reported in the literature. However, no previous study assessing the accuracy or safety of this technique has been published. Structures at risk are the vertebral arteries, spinal canal, and the occiput-C1 joint. METHODS: Five frozen human cadaveric specimens were thawed and instrumented with 10 C1-C2 transarticular screws, according to the technique described by Magerl but using a specially designed aiming device described by the senior author (Jeanneret). After screw placement, the accuracy of screw positioning and the distance of the screws from the spinal canal, vertebral arteries, and atlanto-occipital joint were determined by anatomic dissection and radiographic analysis. RESULTS: The structure at greatest risk was the atlanto-occipital joint, with one screw found to be damaging the joint. Vertebral artery or spinal canal penetration was not observed in any of the specimens. Screw length averaged 45 mm and, with proper length, the screw tip was found to be located approximately 7.5 mm behind the anterior tubercle of C1 on lateral radiographs. CONCLUSIONS: This anatomic study demonstrates that C1-C2 transarticular screw fixation can be performed safely in a normal anatomic situation by surgeons who are familiar with the pertinent anatomy. The aiming device allowed safe instrumentation in all patients. In case of an irregular anatomic situation (e.g., congenital abnormalities or trauma), computed tomographic scan with sagittal reconstruction is recommended-in particular, to obtain information about the course of the vertebral artery.     

Changes in the lumbosacral segment of the spine due to overweight in adults. Preliminary remarks

The Authors studied postural changes in the lumbosacral segment of the spine due to severe obesity in 28 young adults of both sexes. In particular, the preliminary degree of pelvic rotation caused by overweight was evaluated by studying the lumbosacral angle (LSA) amplitude, changes in normal static equilibrium of the spine and lumbar hyperlordosis in relation to the lordotic angle (LA) amplitude. Body Build Index (BBI), the lumbosacral angle and the lordotic angle were compared to determine if any correlations existed among the three. Even though the patient number was limited, pathologic values for both the LSA and the LA were found in all 28 subjects. The Authors found no correlation between LSA and LA increase regarding BBI; on the contrary, a correlation was evident between LSA increase and LA. A decrease in the LSA and LA values took place after reduction in body weight, after therapeutic intervention. The Authors believe that a one year follow-up is necessary to evaluate any long term decrease in the values of the above mentioned angles.     

Bioabsorbable rods and pins for fixation of metacarpophalangeal arthrodesis of the thumb

We report results on the use of bioabsorbable pins and intramedullary rods made of high-molecular-weight polylactic acid in both experimental and clinical conditions. In the experimental study, bioabsorbable rods were implanted in rabbit femora. Histologic assessment on nondecalcified bone showed that resorption of the material began at 4 months after implantation and gradually fragmented over a period of 3 years. In 12 patients 13 metacarpophalangeal joints of the thumb were arthrodesed by using one bioabsorbable intramedullary rod with one or two oblique pins. All joints fused within 6 to 8 weeks. During that period there was no sign of inflammation, and there were no nonunions. Postoperative magnetic resonance imaging assessment was done in all rabbits and eight patients. This modality is a useful tool in postoperative evaluation of the position and shape of the rod but is not sufficiently sensitive to assess the presence of local inflammation and the rate of resorption of the rods.     

Executive coaching: An outcome study.

While executive coaching continues to mushroom as a practice area, there has been little outcome research. This article presents the results of a study that explored factors influencing the choice of a coach, executives' reactions to working with a coach, the pros and cons of both internal and external coaches, the focus of executive coaching engagements, indications of successful coaching engagements, coaching tools executives favored, and the sustainability of coached executives' learning and behavior change. The author also raises a question about which executives are most likely to benefit from this development resource and presents a typology for gauging this issue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive-behavioral therapy for bulimia: An initial outcome study.

Examined the efficacy of a cognitive-behavioral therapy for bulimia with 20 18–30 yr old bulimic females who were randomly assigned in equal numbers to either full- or brief-intervention therapy programs. Three Ss reported a previous history of anorexia nervosa; 3 of the Ss had previously received treatment for bulimia. The full intervention was based on a cognitive-behavioral conceptualization in which bulimia is viewed as a type of obsessive-compulsive problem, and it involved cognitive restructuring, exposure with response prevention, behavioral contracting, and process-oriented psychotherapy. Results indicate that the full-intervention Ss, relative to the brief-intervention Ss, substantially reduced the frequency of their bingeing-vomiting; improved their general psychological adjustment; and changed their attitudes about food, dieting, and their bodies. In addition, data collected in an actual eating situation demonstrated a dramatic reduction in the urge to vomit and level of discomfort for the full-intervention Ss. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cervical spine fractures in the elderly

BACKGROUND: Cervical spine fractures in the elderly are relatively common. The management of such injuries may be complicated by underlying medical debility and osteopenia as well as reduced tolerance to halo immobilization. METHODS: Over a 1-year period, 43 cervical spine fractures were treated at our institution. Ten (23%) were in persons 70 years of age or older. This retrospective analysis describe the clinical features, treatment, and outcome of these 10 elderly patients. All fractures in this patient population involved the atlantoaxial complex, including five combination C1-C2 fractures. Six patients were treated with early halo immobilization and three were initially managed with a rigid cervical collar. Three patients required posterior cervical fusion. RESULTS: Of the six patients undergoing halo immobilization, five progressed to osseous union. Three patients were immobilized in a Philadelphia collar resulting in one osseous union, one nonunion, and one death. Three patients underwent posterior cervical fusion with subsequent osseous union in all three. CONCLUSIONS: Although external immobilization with a halo device is our treatment of choice for most C1 and C2 fractures in elderly patients, a Philadelphia collar is useful in select cases when halo immobilization or early surgical fusion is contraindicated. Posterior cervical fusion can be safely and effectively performed in elderly patients and should be strongly considered for initial therapy in the elderly with fracture types unlikely to progress to osseous union with external immobilization alone.     

Safe lateral-mass screw lengths in the Roy-Camille and Magerl techniques. An anatomic study

STUDY DESIGN: Investigation of the mean safe lateral-mass screw lengths in the Roy-Camille and Magerl screw techniques in cadaveric cervical specimens. OBJECTIVES: To report the mean screw path length and to evaluate the relation of the screw trajectory to the nerve root in the Roy-Camille and Magerl screw techniques. SUMMARY OF BACKGROUND DATA: Potential injury to the cervical nerve root caused by too long a screw remains a major concern. Few studies regarding proper screw length and its relation to the adjacent nerve root are available. METHODS: Fourteen cervical spines were used for this study. Each lateral mass from C3 to C7 was drilled according to the techniques described by Roy-Camille (right side) and Magerl (left side). The cervical spines were harvested from the cadavers, and the anterior aspect of the lateral mass and spinal nerve were exposed. The screw path length between the dorsal and ventral cortices of the lateral mass were measured. An additional measurement was taken from the ventral aspect of the lateral mass to the nerve root along the screw path. RESULTS: The mean screw path length in the Roy-Camille technique decreased consistently from C3 (15.7 +/- 1.7 mm) to C7 (11.3 +/- 0.8 mm). The mean distance from the ventral cortex to the nerve root ranged from 1.2 to 2.3 mm, and the smallest value was at C7. The mean screw path length in the Magerl technique also decreased from cephelad to caudal, with a range of 15-16 mm at C3-C6 and a mean value of 13.8 mm at C7. CONCLUSIONS: A safe screw length is 14-15 mm in the Roy-Camille technique and 15-16 mm in the Magerl technique at C3-C6. A short screw may be used at C7 if desired.     

Anatomic study for ideal and safe posterior C1-C2 transarticular screw fixation

STUDY DESIGN: Directions of the C1-C2 posterior transarticular screw trajectories making the longest path or violating the transverse foramen were measured by using an objective measuring method. OBJECTIVES: To clarify the directions of the screw trajectory marking the longest paths without violating the transverse foramen. To achieve this, diverse directions of the screw trajectories were objectified by measuring the locations of the points of screw intersection on the superior articular surface of C2. SUMMARY OF BACKGROUND DATA: The principal limitation of posterior C1-C2 transarticular screw fixation is the location of the vertebral artery. Because of the lack of an objective measuring method, surgical unsuitability has been decided on the basis of individual experiences as reported in 18% to 23% of cases. METHODS: Sagittal reconstructed computed tomographic images were made at 3.5 mm and 6 mm from the spinal canal. C1-C2 transarticular screw trajectories making the longest path or violating the transverse foramen (dangerous trajectory) were drawn, and their points of screw intersection on the superior articular surface of C2 were measured from the posterior rim of the superior articular surface of C2. When the space available for the screw behind the points of screw intersection by the dangerous trajectory was equal to or less than 3.5 mm, the case was defined as "unacceptable"; when the space available for the screw was more than 3.5 mm but equal to or less than 4.5 mm, it was defined as "risky" for the placement of the screw. RESULTS: Trajectories make the longest paths when they pass an average of 3.6 mm and 2.8 mm anterior to the posterior rim of the posterior articular surface of C2 at 3.5-mm lateral images and 6-mm lateral images, respectively. Four of 64 cases were unacceptable or risky unilaterally on 3.5-mm lateral images, and 21 cases were unacceptable or risky on 6-mm lateral images. A sigmoid-shaped increment curve of the risk was noted as the increasing forward inclination of the screw trajectories increased. CONCLUSIONS: The areas on the superior articular surface of C2 intersected by the trajectories making the longest paths without violating the transverse foramen are clarified as a guide to the ideal and safe trajectories. The theoretical minimal risk and usual risk of the posterior C1-C2 transarticular screw fixation are presented as well.     

Surgery of the spine in myelodysplasia. An overview

Significant spinal deformity is particularly common in nonambulatory patients with myelodysplasia. Progressive deformity may be caused by congenital anomalies, paralytic collapse, hip contractures, or spinal cord tethering. Existing or projected functional impairment should be the principle indication for treatment. Surgical treatment is complicated by poor soft tissue coverage, associated contractures, lack of sensation, weak bone, and absence of posterior elements. Successful fusion can be achieved by circumferential (anterior and posterior) fusion and current rigid segmental instrumentation. The unique deformities and bony anatomy require individualized techniques to achieve fixation.