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The influence of the tibial plateau orientation on cancellous bone stress was examined by finite element analysis for a cemented device. The objectives of the study were i) to examine the effect of the plateau-ankle angle on the cancellous bone stress, ii) to analyze the significance of the anteroposterior angles of the tibial component on these stresses, and iii) to compare the finite element predictions with clinical data. In general, positioning the tibial plateau in valgus resulted in lower cancellous bone stresses. These results support previous clinical studies, which suggest that overall alignment in valgus results in lower migration rates and lower incidence of loosening.

Explains the reasons behind, and the methodology of, a project to introduce a systematic work measurement programme based on standard data to a particular set of operations at the Rank Xerox Mitcheldean site. Points out both the successes and failings of the resultant scheme.

A group of 45 patients who underwent replacement of a ruptured anterior cruciate ligament with a free graft of one-third of the patellar tendon combined with a lateral extra-articular tenodesis have been reviewed. The average age of the patients was 26.4 years and the mean follow-up period 3.2 years. Stability was achieved in 42 patients (93 per cent), judged on clinical criteria. Overall patient satisfaction was high at 73 per cent and 38 patients (84 per cent) maintained their sporting activity at a social or competitive level. Those who had unsatisfactory results had undergone significant delay before anterior cruciate ligament reconstruction.

Potentially dangerous muscle damage is often overlooked in the salvage of severely injured limbs. Muscle damage may be due to direct injury with crush, laceration or contusion. This may be complicated by ischaemia through prolonged compression at the time of injury or later as a result of raised compartmental pressure. The result of muscle damage, irrespective of cause, is rhabdomyolysis, in which alteration of the cell membrane occurs with release of intracellular contents. The systemic effect of rhabdomyolysis can vary from transient mild hyperkalaemia, hypocalcaemia, myoglobinaemia and elevated creatinine phosphokinase to the lifethreatening crush syndrome with hypovolaemic shock, cardiac arrhythmias and acute myoglobinuric renal failure. The local effect is increased capillary permeability resulting in accumulation of tissue fluid and raised compartment pressure. Rhabdomyolysis may therefore cause compartment syndrome; however, the converse is true, with prolonged compartment syndrome small vessel thrombosis may cause cellular death with subsequent rhabdomyolysis despite axial vessel patency (Kitka et al., 1987). The crush syndrome was first described in air raid victims trapped under falling masonry (Bywaters and Beall, 1941); however, it may be encountered in peacetime as is illustrated by the following three cases.