Outcome of lumbar spinal fusion surgery in obese patients: a systematic review and meta-analysis.

The aim of this study was to determine whether obesity affects pain, surgical and functional outcomes following lumbar spinal fusion for low back pain (LBP). A systematic literature review and meta-analysis was made of those studies that compared the outcome of lumbar spinal fusion for LBP in obese and non-obese patients. A total of 17 studies were included in the meta-analysis. There was no difference in the pain and functional outcomes. Lumbar spinal fusion in the obese patient resulted in a statistically significantly greater intra-operative blood loss (weighted mean difference: 54.04 ml; 95% confidence interval (CI) 15.08 to 93.00; n = 112; p = 0.007) more complications (odds ratio: 1.91; 95% CI 1.68 to 2.18; n = 43858; p < 0.001) and longer duration of surgery (25.75 mins; 95% CI 15.61 to 35.90; n = 258; p < 0.001). Obese patients have greater intra-operative blood loss, more complications and longer duration of surgery but pain and functional outcome are similar to non-obese patients. Based on these results, obesity is not a contraindication to lumbar spinal fusion.

Isolation & cryo-preservation of human foetal articular chondrocytes.

An attempt to determine the ideal temperature and duration of storage of human foetal chondrocytes yielded highly cellular preparations with no alteration in morphology or loss of viability. Initial digestion with activated papain was followed by incubation in 0.5 per cent collagenase. Trypan blue exclusion test revealed a viability count of 95-99 per cent and radioactive thymidine uptake a corresponding labelling index. On TEM no subcellular damage was evident. The isolated viable chondrocytes were further banked at varying temperatures of +4 degrees, -4 degrees, -30 degrees, -79 degrees and -196 degrees C, in Eagles MEM with 10 per cent dimethyl sulfoxide. Post storage morphology and viability of these cells, thawed after durations of 20 h, 1 wk, 1, 2, 3, 4 and 6 months, were compared with prestorage readings in an attempt to define the ideal temperature for banking. Storage in liquid nitrogen at -196 degrees C demonstrated excellent preservation even at the end of six months with minimal subcellular change. Electron microscopy and labelling index were found to be superior to Trypan blue exclusion test in assessing the stored chondrocytes for retention of their functions.

Allogenic transplantation of ultra-deep frozen osteochondral grafts. An experimental study in dogs.

Twenty dogs were subjected to allotransplantation of the lower end of the femur, frozen at -196 degrees C for 24 hours in liquid nitrogen, and stored at -30 degrees C. Two dogs were sacrificed at monthly intervals, providing the grafted bone for histological study. Eight dogs were excluded from the study following infection or death, resulting in a follow up of only 6 months. Monthly roentgenographic assessment showed bridging of the host-graft unit by the second month, with posterior subluxation of the graft with subsequent malunion. Histologically, exuberant callus was seen around the interface with progressive incorporation of the graft. However, the articular cartilage degenerated after 2 months. Attempts to repair the articular surface with new fibrocartilage were poor in the malunited grafts. The technical problems in surgery including control of infection, sound mechanical fixation and repair of tendons and ligaments must be solved to ensure a successful allograft.