A retrospective follow-up study of patients who, having undergone instrumented posterior spinal fusion for scoliosis, experienced late infection and then underwent either implant removal alone or implant removal and instrumented refusion. We conducted this study to determine whether it is possible to avoid loss of correction by a single-stage implant removal and reinstrumentation procedure. There have been a few reports of late-appearing infections after spinal instrumentation. Implant bulk, metallurgic reactions, and contamination with low-virulence microorganisms have been suggested as possible etiologic factors. The clinical symptoms include pain, swelling, redness, and spontaneous drainage of fluid. Complete instrumentation removal and systemic antibiotics is usually curative. We retrospectively reviewed 45 patients who underwent instrumented posterior spinal fusion for scoliosis and experienced development of late infections and, after a mean of 3 years after the initial procedure, either underwent implant removal alone [n=35, instrumentation removal (HR) group] or additionally underwent reinstrumentation and fusion [n=10, reinstrumentation and fusion (RI&F) group]. Three patients were reinstrumented 1.5 years after

The significance of obesity as a risk factor for postoperative complications was determined in a consecutive series of 229 cases of revision total hip replacement. The body mass index (BMI) was used as an objective measure to classify the patients. The group-wise analysis of data included all medical and procedure-related complications, the number of fatal cases, operative time, requirement for analgesics, the number of transfusions and perioperative haemoglobin levels. The results of our study demonstrate a clear association between obesity and operative time, whereas no statistically significant relationships were observed between obesity and the other parameters. We conclude that obesity does not have any significant influence on perioperative morbidity and mortality but is clearly related to operation time and, therefore, to higher costs per operation.

IntroductionDespite modern fixation techniques, pseudarthrosis is a major cause of failure in the surgical treatment of idiopathic scoliosis. To avoid this, dorsal spondylodesis requires the use of large quantities of bone graft. Autologous bone graft from spinal process and iliac crest often provides insufficient quantities. In addition, morbidity after harvesting bone from the pelvis is considerable [1,7].Allograft bone from bone banks carries known risks of bacterial contamination and viral transmission [2,5].Because of these problems, there is an increasing interest in biodegradable osteoconductive ceramic bone graft substitutes. These materials must fulfil certain properties [1,13]: compatibility with surrounding tissues, chemical stability in body fluids, compatibility of mechanical and physical properties, ability to be produced in functional shapes and to withstand the sterilization process, reasonable cost of manufacture and reliable quality control.Abstract The aim of this study is to evaluate the ability of β-tricalcium phosphate (TCP) in granular form to achieve dorsal spondylodesis in adolescent idiopathic scoliosis (AIS). Twenty-eight patients underwent surgical correction and were followed up for 13±8 (range 6-33) months. Posterolateral grafting was performed, using either autograft bone mixed with allograft bone (n=19; "bone group") or autograft bone mixed with 25 g TCP (n=9; "TCP group"). Patients were followed by clinical examination, X-rays and computed tomographic (CT) scans to measure bone mineral density. Fusion involved 12±1 (range 10-14) vertebrae. The segments were fused after 6±1 months in both groups according to the radiographs. No pseudarthrosis was observed. Bone mineral density was 430±111 (range 273-629) mg/cm 3 in the TCP group versus 337±134 (range 130-669) mg/cm 3 in the bone group. Resorption of TCP was complete on the radiographs after 8±2 (range 6-10) months. Based upon the results of this small preliminary study, the use of TCP appears to be a valuable alternative to allografts for application in the spine, even when large amounts of bone are needed.

Ventral derotation spondylodesis, according to Zielke, achieves good results in operative treatment of idiopathic thoracic scolioses. Corrections of scoliotic major and secondary curve as well as derotation of the spine are reliably performed. The high rate of rod fractures with subsequent correction loss as well as a proportionate kyphogenic effect represents a problem. By keeping to the correcting principle, anterior double-rod instrumentation (Halm-Zielke Instrumentation) is to be stable in a similar way as posterior double-rod systems. Thus, it is done to facilitate brace-free postoperative care and to prevent excessive kyphotic pattern of the spine. In this prospective study, we retrospectively collected data. We performed radiological follow-up of two groups of patients with idiopathic thoracic scoliosis (King II, III and IV) undergoing an operation with posterior approach (USS instrumentation, posterior group, n=104) in 1997 and 1998 or being corrected with an anterior fusion (Halm-Zielke instrumentation, anterior group, n=37) between 2000 and 2001. Mean age of all patients for operation was 15+/-4 years. Follow-up was performed after 4+/-2 years on average. Preoperative measurements of the major and secondary curve, the lateral profile, rotation and frontal balance (C7 to S1) did not show any significant differences apart from a more severe scoliotic curve in the lumbar spine for the anterior group with appropriately higher lumbar rotation. During follow-up we noticed similar corrections of the thoracic major and lumbar curve in both groups ranging from 49 to 56%. In case of hypokyphotic (T4-T12or=40 degrees ) scolioses were flattened by posterior spinal fusion; the effect of anterior spinal fusion was not significant. Correction of thoracic and lumbar rotation in the anterior group by 37 or 30% was more significant than in the posterior group by 27 or 20%. There was no impact of anterior technique on the balance of the spine whereas the latter shifted by an average of 7 mm to the left in the posterior group. The number of fused segments was significantly smaller in the anterior group with 7+/-1 vertebral bodies (posterior, 11+/-1 vertebral bodies). Rates of complication were identical with 11 or 12% in both groups during follow-up. Anterior and posterior double-rod instrumentations result in comparable corrections for idiopathic thoracic scoliosis of the major and secondary curve. In case of posterior technique, however, four vertebral bodies less were integrated in spondylodesis on average. Balance of the spine did not change after anterior spondylodesis; however, it declined by using the posterior technique. Augmentation of the anterior threaded rod combined with a solid second rod significantly decreases the rate of implant breakages and reliably reduces consecutive correction losses.

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