We used 15 pairs of femora from fresh human cadavers to study the effects of the size and location of the entry hole for an intramedullary nail on the strength of the femur. Right femora were used as controls. Left femora in group 1 had a 10 mm entry hole in the 'ideal' location in the piriformis fossa. Group 2 had a 14 mm entry hole in the same position and group 3 had a 14 mm entry hole anterior to this on the superior aspect of the femoral neck. Femora were equipped with strain gauges and loaded to failure in compression. There was reduced stiffness and load to failure in group 3 specimens, suggesting that the location of the hole was more important than its size.

We examined the menisci in 47 patients at the time of anterior cruciate ligament reconstruction. Twenty-one patients had abnormal menisci at a mean of 34 months after injury, but there was no difference between the Lysholm scores of patients with intact or damaged menisci. Eleven patients had a new meniscal injury between reconstruction and review at a mean of six years later; only 15 patients had both menisci intact nine years after injury. If pivot shift had been cured, the incidence of meniscal injury was reduced, but remained higher than normal. If pivot shift returned after reconstruction there was a significantly higher incidence of meniscal injury. Meniscal lesions appear to be the result of instability and not the cause.

Forty-seven patients with disabling instability due to isolated anterior cruciate deficiency are described. None had responded to conservative measures or to attempted correction of internal derangements. Eighteen patients were treated by extra-articular MacIntosh lateral substitution alone, the other 29 were treated by the same procedure combined with carbon-fibre replacement of the anterior cruciate ligament. No statistically significant difference was found between the two groups at six years. A satisfactory outcome was found in 44% of the extra-articular group and 55% of the carbon-fibre group at last review; however, the latter group had more complications. There was a marked deterioration in the quality of results between three and six years in both groups.