SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Spinal fusion

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Chronic low back pain (cLBP) represents a major challenge to our health care systems. The relative efficacy of surgery over nonoperative treatment for the treatment of cLBP remains controversial, and little is known of the long-term comparative outcomes.

Concepts: Health care, Medicine, Epidemiology, Low back pain, Back pain, Randomized controlled trial, Spinal fusion

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BACKGROUND:Erythrocyte cell membranes undergo morphologic changes during storage, but it is unclear whether these changes are reversible. We assessed erythrocyte cell membrane deformability in patients before and after transfusion to determine the effects of storage duration and whether changes in deformability are reversible after transfusion.METHODS:Sixteen patients undergoing posterior spinal fusion surgery were studied. Erythrocyte deformability was compared between those who required moderate transfusion (≥5 units erythrocytes) and those who received minimal transfusion (0-4 units erythrocytes). Deformability was measured in samples drawn directly from the blood storage bags before transfusion and in samples drawn from patients before and after transfusion (over 3 postoperative days). In samples taken from the blood storage bags, we compared deformability of erythrocytes stored for a long duration (≥21 days), those stored for a shorter duration (<21 days), and cell-salvaged erythrocytes. Deformability was assessed quantitatively using the elongation index (EI) measured by ektacytometry, a method that determines the ability for the cell to elongate when exposed to shear stress.RESULTS:Erythrocyte deformability was significantly decreased from the preoperative baseline in patients after moderate transfusion (EI decreased by 12% ± 4% to 20% ± 6%; P = 0.03) but not after minimal transfusion (EI decreased by 3% ± 1% to 4% ± 1%; P = 0.68). These changes did not reverse over 3 postoperative days. Deformability was significantly less in erythrocytes stored for ≥21 days (EI = 0.28 ± 0.02) than in those stored for <21 days (EI = 0.33 ± 0.02; P = 0.001) or those drawn from patients preoperatively (EI = 0.33 ± 0.02; P = 0.001). Cell-salvaged erythrocytes had intermediate deformability (EI = 0.30 ± 0.03) that was greater than that of erythrocytes stored ≥21 days (P = 0.047), but less than that of erythrocytes stored <21 days (P = 0.03).CONCLUSIONS:The findings demonstrate that increased duration of erythrocyte storage is associated with decreased cell membrane deformability and that these changes are not readily reversible after transfusion.

Concepts: Protein, Gene, Cell nucleus, Cell, Cytosol, Cell membrane, Red blood cell, Spinal fusion

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To identify factors that account for variation in complication rates across hospitals and surgeons performing lumbar spinal fusion surgery.

Concepts: Hospital, Surgery, Physician, Surgeon, American College of Surgeons, Spinal fusion

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STUDY DESIGN.: Meta-analysis on mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion. OBJECTIVE.: To compare mid- to long-term outcomes and complications of the most commonly used instrumentation systems in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA.: A meta-analysis of mid- to long-term results of different methods of instrumentation, including the most currently used all-pedicle screw construct, is lacking. METHODS.: A structured literature review was conducted for studies concerning management of patients with adolescent idiopathic scoliosis with instrumented posterior fusion. Pooled means, standard deviations, and sample sizes were either identified or calculated on the basis of the results of each study. RESULTS.: Meta-analyses were performed on outcomes from 27 studies. Overall, 1613 patients who had been treated with Harrington rods, 361 patients who had undergone Cotrel-Dubousset instrumentation, and 298 patients who managed with all-pedicle screw constructs were reviewed. The mean follow-up was 14.9 years. Cotrel-Dubousset and pedicle screw instrumentations achieved a significantly greater degree of correction of the thoracic curve than Harrington rods (40.3° vs. 14.7°; P < 0.001 and 21.9° vs. 14.7°; P = 0.005, respectively). Cotrel-Dubousset technique achieved a significantly higher degree of correction than all-pedicle screw construct in both the thoracic (40.3° vs. 21.9°, respectively; P < 0.001) and lumbar curves (37.2° vs. 16°, respectively; P < 0.001). Similarly, Cotrel-Dubousset construct achieved a greater correction of both thoracic kyphosis (33.5° vs. 23°, respectively; P < 0.001) and lumbar lordosis (46° vs. 50.7°, respectively; P = 0.002) than pedicle screws. All-pedicle screw fixation was associated with the lower risk of pseudarthrosis, infection, neurological deficit, and reoperation. CONCLUSION.: This study confirms the negative effect of Harrington rods on sagittal alignment. We further found that the degree of correction in the coronal and sagittal planes was higher after Cotrel-Dubousset instrumentation than all-pedicle screw fixation. All-pedicle screw constructs offered the lower risk of mid- to long-term complications and revision surgery.

Concepts: Vertebral column, Scoliosis, Lordosis, Spinal fusion, Kyphosis, Scheuermann's disease, Kyphoscoliosis, Harrington implant

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STUDY DESIGN.: Prospective case series study. OBJECTIVE.: To study the effect of percutaneous thoracoplasty-only procedure on curve pattern in mature adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA.: The rib hump prominence on the convex side is the major cosmetic concern among patients with AIS. Thoracoplasty combined with spinal fusion is a commonly used procedure in scoliosis. However, there are no studies regarding the effect of isolated thoracoplasty procedure on curve pattern in skeletally matured patients with AIS. METHODS.: The study involved 7 skeletally matured female patients with AIS. The convex rib hump deformity was measured preoperatively using hump height and hump angle. We performed thoracoplasty without spinal fusion in patients with the Cobb angle less than 40° but with prominent hump deformity. Thoracoplasty was performed percutaneously using 1 or 2 transverse incisions along the rib hump, and apex portions of the deformed ribs were resected. The Cobb angle was measured before surgery, immediately after surgery, and at final follow-up visit. In all cases, clinical satisfaction was assessed using the Scoliosis Research Society Instrument (SRS-22 questionnaires) and trunk appearance perception scale before surgery and at final follow-up visit. RESULTS.: The mean patient age was 20.24 years and an average of 4 ribs were resected. The mean preoperative hump height and hump angle of 38.14 mm and 14.14° improved to 11.70 mm and 11.42° respectively, after surgery (P = 0.018 and 0.042). Preoperative and the final follow-up mean Cobb angles were 35.43° and 45.00°, respectively (P = 0.028). On average, the mean thoracic curve progressed by 9.57°. Preoperative Scoliosis Research Society Instrument SRS-22 questionnaires and trunk appearance perception scale scores of 4.09 and 2.57 respectively improved to and 4.26 and 3.66 after surgery (P = 0.126 and 0.014). CONCLUSION.: Percutaneous thoracoplasty-only procedure gives significant rib humps correction and satisfactory clinical outcome. However, progression of the curve was observed after surgery. This suggests that the convex ribs function as a buttress for curve progression.

Concepts: Vertebral column, Scoliosis, Arithmetic mean, Paul Randall Harrington, Scoliosis Research Society, Thorax, Spinal fusion, Case series

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STUDY DESIGN.: This is a case report. OBJECTIVE.: To report a case of soft-tissue reaction to wear debris and osteolysis around a pedicle screw after posterior spine fusion in a pediatric patient. SUMMARY OF BACKGROUND DATA.: Posterior spine fusion with instrumentation is a standard procedure for stabilization and curve correction in patients with scoliosis. Late operative site pain accounts for the highest frequency of reoperation. Debris accumulation for steel and titanium constructs occurs at the pedicle screw-rod junction. Cellular reaction to metal wear may be responsible for osteolysis and aseptic loosening around spinal implants. METHODS.: A 14-year-old male patient with neurofibromatosis and right thoracic scoliosis of 50° underwent posterior spine fusion from T2 to T10. The postoperative course was complicated by continuous pain, and imaging studies demonstrated hardware failure, requiring a revision and subsequent development of a perihilar opacity of unknown origin. Further studies demonstrated hypermobility with adjacent soft-tissue reactivity and inflammation surrounding the right T5 transpedicle screw. RESULTS.: After hardware removal, the patient’s recovery was uneventful. Six months later, a repeated computed tomographic scan demonstrated resolution of the previously described soft-tissue mass and a satisfactory fusion of the thoracic spine. CONCLUSION.: Metal wear debris can form in pediatric patients during the healing process after spinal fusions or when pseudarthrosis is present. Clinically, this manifests as back pain with a possible aseptic inflammatory abscess. Hardware removal can achieve resolution of symptoms and regression of inflammation.

Concepts: Patient, Vertebral column, Scoliosis, Right-wing politics, Thoracic vertebrae, Conservatism, Spinal fusion, Reactionary

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Study Design. Retrospective case control study.Objective. To evaluate the effectiveness of bracing in patients with Chiari malformation-associated scoliosis (CMS) following posterior fossa decompression (PFD).Summary of Background Data. The effectiveness of bracing has been poorly studied in CMS patients who have received PFD.Methods. A retrospective study was conducted on 22 CMS patients who received brace treatment for their scoliosis following PFD. Forty-four age- and gender-matched IS patients who received bracing served as the control group. The bracing outcome was considered a failure if the curve worsened ≥ 6°; otherwise, the treatment was considered to be successful.Results. The age and Risser grade were similar between the CMS and IS patients at brace initiation. The initial curve magnitude of CMS patients (mean, 32.9° ± 6.3°; range, 20°-45°) was marginally significantly larger than that of the IS patients (mean, 29.6° ± 6.4°; range, 20°-45°). Until the final follow-up, a ≥ 6° worsening of the major curve occurred in 8 CMS patients (36%) and in 15 IS patients (34%). Overall, 7 CMS patients (32%) and 13 IS patients (30%) underwent spinal fusion surgery. No significant differences were observed between the two groups in the surgery rates or the bracing success rates (P>0.05). In the CMS patients, neither the performance of syringosubarachnoid shunting nor the extent of tonsillar descent correlated with the bracing outcomes, whereas a double major curve pattern was found to be predictive for the failure of bracing.Conclusion. Brace treatment subsequent to PFD is effective in preventing curve progression for 64% of CMS patients, which is comparable to the rate that is observed in IS patients. Double major curve pattern may be a risk factor in predicting treatment failure in CMS patients.

Concepts: Scientific method, Vertebral column, Scoliosis, The Age, Retrospective, Major, Spinal fusion, Scheuermann's disease

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This report describes the imaging findings in three patients who developed lumbar spine osteolysis after posterior spinal fusion using rhBMP-2. These cases demonstrate the variable course of osteolysis, as well as the importance of recognizing its radiological appearances to prevent confusion with infection following spinal fusion.

Concepts: Bone, Lumbar vertebrae, Vertebral column, Orthopedic surgery, Spinal fusion

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STUDY DESIGN.: A case report. OBJECTIVE.: An elderly patient presented with an acute lumbar spinal pseudogout attack after lumbar instrumented surgery. SUMMARY OF BACKGROUND DATA.: Although gout and pseudogout are common diseases causing inflammatory arthropathy in peripheral joints, involvement of the spine is uncommon. Here, we report a patient experiencing an acute lumbar spinal pseudogout attack after lumbar instrumented surgery. METHODS.: The patient was treated for lumbar spondylolisthesis at L4 and L5 level and afterward complained of lower back and bilateral leg pain. Conservative treatment was not effective for the patient; therefore, we preformed posterior transforaminal lumbar interbody fusion surgery. RESULTS.: The postoperative course was uneventful; however, he experienced lower back pain 4 weeks after surgery. Magnetic resonance image showed changes in signal intensities of vertebra and fluid accumulation in posterior back muscles. A biopsy was performed, but the culture was negative for infection. Calcium pyrophosphate dehydrate was detected in the fluid. Thus, conservative therapy without antibiotics was performed, and the patient’s symptoms disappeared within 2 weeks. CONCLUSION.: Here, we reported the first case of acute lumbar spinal pseudogout attack after lumbar instrumented surgery. We recommend considering pseudogout before and after surgery.

Concepts: Disease, Spinal disc herniation, Medical terms, Nuclear magnetic resonance, Vertebral column, Symptoms, Ultrasound, Spinal fusion