B. J. van Royen

ASAS/EULAR recommendations for the management of ankylosing spondylitis

Objective: To develop evidence based recommendations for the management of ankylosing spondylitis (AS) as a combined effort of the ‘ASsessment in AS’ international working group and the European League Against Rheumatism. Methods: Each of the 22 participants was asked to contribute up to 15 propositions describing key clinical aspects of AS management. A Delphi process was used to select 10 final propositions. A systematic literature search was then performed to obtain scientific evidence for each proposition. Outcome data for efficacy, adverse effects, and cost effectiveness were abstracted. The effect size, relative risk, number needed to treat, and incremental cost effectiveness ratio were calculated. On the basis of the search results, 10 major recommendations for the management of AS were constructed. The strength of recommendation was assessed based on the strength of the literature evidence, risk-benefit trade-off, and clinical expertise. Results: The final recommendations considered the use of non-steroidal anti-inflammatory drugs (NSAIDs) (conventional NSAIDs, coxibs, and co-prescription of gastroprotective agents), disease modifying antirheumatic drugs, treatments with biological agents, simple analgesics, local and systemic steroids, non-pharmacological treatment (including education, exercise, and physiotherapy), and surgical interventions. Three general recommendations were also included. Research evidence (categories I–IV) supported 11 interventions in the treatment of AS. Strength of recommendation varied, depending on the category of evidence and expert opinion. Conclusion: Ten key recommendations for the treatment of AS were developed and assessed using a combination of research based evidence and expert consensus. Regular updating will be carried out to keep abreast of new developments in the management of AS.

Lumbar osteotomy for correction of thoracolumbar kyphotic deformity in ankylosing spondylitis. A structured review of three methods of treatment

OBJECTIVES Three operative techniques have been described to correct thoracolumbar kyphotic deformity (TLKD) resulting from ankylosing spondylitis (AS) at the level of the lumbar spine: opening wedge osteotomy, polysegmental wedge osteotomies, and closing wedge osteotomy. Little knowledge exists on the indication for, and outcome of these corrective lumbar osteotomies. METHODS A structured review of the medical literature was performed. RESULTS A search of the literature revealed 856 patients reported in 41 articles published between 1945 and 1998. The mean age at time of operation was 41 years, male-female ratio 7.5 to 1. In 451 patients an open wedge osteotomy was performed. Polysegmental wedge osteotomies were performed in 249 patients and a closing wedge osteotomy in 156 patients. Most of the studies primarily focus on the surgical technique. Technical outcome data were poorly reported. Sixteen reports, including 523 patients, met the inclusion criteria of this study, and could be analysed for technical outcome data. The average correction achieved with each surgical techniques ranged from 37 to 40 degrees. Loss of correction was mainly reported in patients treated by open wedge osteotomy and polysegmental wedge osteotomies. Neurological complications were reported in all three techniques. The perioperative mortality was 4%. Pulmonary, cardiac and intestinal problems were found to be the major cause of fatal complications. CONCLUSION Lumbar osteotomy for correction of TLKD resulting from AS is a major surgery. The indication for these lumbar osteotomies as well as the degree of correction in the lumbar spine has not yet been established. Furthermore, there is a need for a generally accepted clinical score that encompasses accurate preoperative and postoperative assessment of the spinal deformity. The results of this review suggest that the data from the literature are not suitable for decision making with regard to surgical treatment of TLKD resulting from AS.

Accuracy of the sagittal vertical axis in a standing lateral radiograph as a measurement of balance in spinal deformities

Abstract Sagittal balance of the spine is becoming an important issue in the assessment of the degree of spinal deformity. On a standing lateral full-length radiograph of the spine, the plumb line, or sagittal vertical axis (SVA), can be used to determine the spinal sagittal balance. In this procedure patients have to adopt a habitual standing position with the knees extended during radiographic examination, though it is not known whether small changes in the position of the lower extremities affects the location of the SVA. The purpose of the present study was to investigate the effect of postural change on shifts of the SVA, and to evaluate whether the SVA as measured on a standing full-length lateral radiograph can be used as an accurate measurement of spinal balance in clinical practice. Sagittal balance was analyzed using a patient with ankylosis of the entire spine due to ankylosing spondylitis, to eliminate segmental movement of the spine. A virtual SVA was constructed for seven different standing postures by cross-referring the coordinate systems from a standing full-length lateral radiograph of the spine with video analysis. The horizontal distance between the SVA and the anterior superior corner of the sacrum was measured for each posture. Small changes in the joint angles of the lower extremities affected the SVA significantly, and resulted in the horizontal distance between the SVA and the anterior superior corner of the sacrum varying from –4.5 to +14.9 cm. High correlations were found between this distance and the joint angle of the hip (r = –0.959), knee (r = –0.936), and ankle (r = 0.755) (P < 0.01). The results of the study showed that SVA translations during standing radiographic analysis in a patient with a fixed spine depend on small changes in the hip, knee, and ankle joints. Thus, sagittal spinal (im)balance in ankylosing spondylitis can not be measured from the SVA on a standing lateral full-length radiograph of the spine unless strict procedures are developed to control for the angle of the hip, knee, and ankle joints. The accuracy of the SVA as a measurement of sagittal spinal balance in other spinal deformities, with possible additional segmental movements, therefore remains questionable.

Deformity planning for sagittal plane corrective osteotomies of the spine in ankylosing spondylitis.

Abstract Ankylosing spondylitis (AS) may lead to a severe fixed thoracolumbar kyphotic deformity (TLKD) of the spine. In a few patients, the TLKD is so extreme that a corrective osteotomy of the spine may be considered. Several authors have reported the results of patients treated by a lumbar osteotomy, but there is no consensus on the level of the osteotomy and on the exact degree of correction required. This can be explained by the lack of quantification of the sagittal plane deformity, since compensation mechanisms of the lower extremities have to be reckoned with for the assessment of spinal sagittal balance in AS. Therefore, there is a need for a method of deformity planning for sagittal plane corrective osteotomies of the spine in AS. In this study, a biomechanical analysis and a newly developed planning procedure are presented and illustrated with two cases of AS. Sagittal balance of the spine was defined in relation to the physiologic sacral end plate angle using trigonometric terms. Nomograms were constructed to show the relationship between the correction angle, horizontal position of the C7 plumb line and the level of the spinal osteotomy. The surgical results of two patients were retrospectively analyzed with our method. It showed that the effect of a spinal osteotomy on the horizontal position of the C7 plumb line depends on the combination of correction angle and the level of osteotomy. In one patient, the achieved correction of the deformity proved to correct the sagittal spinal balance and the pelvic sacral endplate angle. In the other patient, the achieved correction was not sufficient. It is concluded that adequate deformity planning for sagittal plane corrective osteotomies of the spine in AS is essential for reliable prediction of the effect of a lumbar osteotomy on the correction of the spine.

Polysegmental lumbar posterior wedge osteotomies for correction of kyphosis in ankylosing spondylitis

Abstract Between 1984 and 1993 we treated 21 consecutive patients who had progressive thoracic kyphosis due to ankylosing spondylitis by polysegmental posterior lumbar wedge osteotomies. In 19 patients we used the Universal Spinal Instrumentation System and in the last 2 patients the H-frame. The average correction in 20 of 21 patients at follow-up was 25.6° (range 0°–52°), with a mean segmental correction of 9.5° and a mean loss of correction after operation of 10.7° (range 0°–36°). There were no fatal complications, but in one patient no correction could be obtained during surgery and another patient was reoperated due to lack of correction. Breaking out of screws through the pedicle during compressive correction was seen in seven patients. Implant failure, such as breakage of the threaded rods and/or loosening of the junction between the pedicle screw and the rod, occurred in 9 out of 21 patients. Two patients required reoperation at long-term follow-up. Five out of seven deep wound infections required removal of the implant. Polysegmental lumbar wedge osteotomies for correction of progressive thoracic kyphosis in ankylosing spondylitis is only recommended in patients at a mild stage of the disease with mobile discs and in combination with strong instrumentation.

A Dutch guideline for the treatment of scoliosis in neuromuscular disorders

BackgroundChildren with neuromuscular disorders with a progressive muscle weakness such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy frequently develop a progressive scoliosis. A severe scoliosis compromises respiratory function and makes sitting more difficult. Spinal surgery is considered the primary treatment option for correcting severe scoliosis in neuromuscular disorders. Surgery in this population requires a multidisciplinary approach, careful planning, dedicated surgical procedures, and specialized after care.MethodsThe guideline is based on scientific evidence and expert opinions. A multidisciplinary working group representing experts from all relevant specialties performed the research. A literature search was conducted to collect scientific evidence in answer to specific questions posed by the working group. Literature was classified according to the level of evidence.ResultsFor most aspects of the treatment scientific evidence is scarce and only low level cohort studies were found. Nevertheless, a high degree of consensus was reached about the management of patients with scoliosis in neuromuscular disorders. This was translated into a set of recommendations, which are now officially accepted as a general guideline in the Netherlands.ConclusionIn order to optimize the treatment for scoliosis in neuromuscular disorders a Dutch guideline has been composed. This evidence-based, multidisciplinary guideline addresses conservative treatment, the preoperative, perioperative, and postoperative care of scoliosis in neuromuscular disorders.

Fatigue failure in shear loading of porcine lumbar spine segments.

Study Design. An in vitro study on porcine spinal segments. Objectives. To determine the differences in mechanical behavior and fatigue strength in shear loading between intact spinal segments and segments without posterior elements, and between segments in neutral and flexed positions. Summary of Background Data. Limited data are available on shear strength of spinal segments. Literature suggests that shear loading can lead to failure of the posterior elements and failure of the disc, when the posterior elements cannot provide adequate protection. Methods. In 2 experiments, 18 and 20 spines of pigs (80 kg) were used, respectively. Shear strength of the T13–L1 segment was tested, while loaded with 1600-N compression. L2–L3 and L4–L5 segments were loaded with a sinusoidal shear between 20% and 80% of the strength of the corresponding T13–L1 segment and 1600-N compression. In experiment No. 1, the posterior elements were removed in half the segments. In experiment No. 2, half the segments were tested in the neutral position, and half were tested in 10° flexion. Results. The group without posterior elements had failure earlier than the intact group. In the group without posterior element, stiffness increased on failure; in the intact group, it decreased. In experiment No. 2, no differences between groups were found. Conclusions. Repetitive shear loading can induce failure of porcine spinal segments, likely caused by fracture of the posterior elements, and, although repetitive anterior shear forces can also induce disc damage, this appears not to occur in intact segments, not even when flexed close to maximal.

Free vascularized bone graft in spinal surgery: indications and outcome in eight cases.

Abstract In selected spinal deformities the use of a vascularized graft to establish fusion may be considered: compared to a non-vascularized graft it has superior mechanical properties, resulting in greater graft strength and stiffness, and greater effectiveness in facilitating union. Eight patients with a progressive spinal deformity (four cases) and malignancy (four cases) were treated with resection and/or correction and stabilization. To facilitate (multi)level fusion vascularized fibular grafts were used in two cervical and two thoracolumbar deformities. Fibular (two cases) or iliac grafts (two cases) were used in four cases of spinal reconstruction after vertebrectomy for malignancy. In all patients complete incorporation of the graft was obtained within 5 weeks to 8 months postoperatively. Complications occurred in three cases: one patient had a transient laryngeal edema and laryngeal nerve palsy. Another patient had a non-fatal deep vein thrombosis with pulmonary embolisms, successfully treated with anticoagulants. A third patient developed a lung infection and subsequently a deep infection around the dorsal instrumentation; after hardware removal the infection was controlled. At the latest follow-up (mean 30 months, range 24– 48 months) six out of eight patients are alive. One patient died 2.5 years after the intervention due to widespread metastases, while another patient died in the postoperative period due to unknown reasons. Vascularized bone graft in spinal surgery facilitates primary mechanical stability and rapid fusion, and it has higher resistance to infection. The variety of applications of a vascularized graft may extend the range of indications for the use of grafts in spinal surgery.

Trochanter Osteomyelitis and Ipsilateral Arthritis due to Gemella morbillorum

What is the link between infectious disease and acute cholecystitis ? Brucellosis, like typhoid, is an enteric fever in which systemic symptoms generally predominate over disorders of the gastrointestinal tract [1]. Localized brucellosis may result as a complication of bacteremia and may be the only manifestation of chronic infection [8]. Bacterial contamination of the gallbladder via the lymphatic network may occur during a systemic infection such as tuberculosis, typhoid [9] or brucellosis. Bile cultures are not always positive in cases of acute cholecystitis: according to a French study performed in 1991 by Freland et al. [10], they are positive in more than 60% of cases at the time of acute cholecystitis. When the culture is positive, gram-negative bacilli are usually isolated, but sometimes gram-positive cocci and anaerobic bacteria are found [10]. Therefore, it is imperative that blood cultures be performed.

The feasibility of modal testing for measurement of the dynamic characteristics of goat vertebral motion segments

Structural vibration testing might be a promising method to study the mechanical properties of spinal motion segments as an alternative to imaging and spinal manipulation techniques. Structural vibration testing is a non-destructive measurement technique that measures the response of a system to an applied vibration as a function of frequency, and allows determination of modal parameters such as resonance frequencies (ratio between stiffness and mass), vibration modes (pattern of motion) and damping. The objective of this study was to determine if structural vibration testing can reveal the resonance frequencies that correspond to the mode shapes flexion-extension, lateroflexion and axial rotation of lumbar motion segments, and to establish whether resonance frequencies can discriminate specific structural alterations of the motion segment. Therefore, a shaker was used to vibrate the upper vertebra of 16 goat lumbar motion segments, while the response was obtained from accelerometers on the transverse and spinous processes and the anterior side of the upper vertebra. Measurements were performed in three conditions: intact, after dissection of the ligaments and after puncturing the annulus fibrosus. The results showed clear resonance peaks for flexion-extension, lateral bending and axial rotation for all segments. Dissection of the ligaments did not affect the resonance frequencies, but puncturing the annulus reduced the resonance frequency of axial rotation. These results indicate that vibration testing can be utilised to assess the modal parameters of lumbar motion segments, and might eventually be used to study the mechanical properties of spinal motion segments in vivo.