Techniques for the selective cutting of ligaments in cadaver knees defined the static contributions of the posterolateral structures to external rotation, varus rotation and posterior tibial translation from 0° to 120° of flexion under defined loading conditions.

Sectioning of the popliteofibular ligament (PFL) (group 1) produced no significant changes in the limits of the knee movement studied. Sectioning of the PFL and the popliteus tendon (femoral attachment, group 2) produced an increase of only 5° to 6° in external rotation from flexion of 30° to 120° (p < 0.001). Even when other ligaments were sectioned first (group 3), the maximum effect of the PFL was negligible.

Our findings show that the popliteus muscle-tendon-ligament complex, lateral collateral ligament, and posterolateral capsular structures function as a unit. No individual structure alone is the primary restraint for the movements studied. Operative reconstruction should address all of the posterolateral structures, since restoration of only a portion may result in residual instability.

Studies derived from analyses of radiographs and dissections of cadaveric wrists have been directed at testing and disproving the commonly held theories that link chip fractures of the os triquetrum with avulsion. The authors found that the mechanism of such injuries involved a chisel action of the ulnar styloid upon the dorsum of the os triquetrum; furthermore, the impact of a fall on the outstretched arm with the hand rigidly held in strong dorsiflexion and ulnar deviation could be forceful enough to fracture the body of the os triquetrum as well. In all cases a striking prolongation of the ulnar styloid, beyond the surface of the ulnar head, was consistently noted.

1. A case of bilateral spontaneous and simultaneous rupture of the quadriceps tendons is described.

2. The underlying cause was found to be gouty affection of the tendons.

3. So far as is known, a similar case has not previously been recorded.

1. Three cases of paralysis of the radial nerve after intensive muscular effort in extension of the elbow are described. Clinical and electrophysiological evidence is recorded.

2. There was motor and sensory affection of varying degree and extent in the distribution of the radial nerve.

3. The type of lesion in each case was that of neurapraxia, and rapid spontaneous recovery occurred in each case.

4. The level of the lesion was in the arm, below the origin of the branches to the triceps.

5. The cause of the lesion was thought to be compression by a fibrous arch related to the lateral head of the triceps.

6. The cases are discussed in relation to other instances of compression of nerves by fibrous arches, and an explanation is advanced for spontaneous recovery.

1. Three cases of the Laurence-Moon-Biedl-Bardet syndrome occurring in a Yemenite family are presented. The parents were first cousins.

2. In two of the patients the complete syndrome, which comprises retinitis pigmentosa, polydactyly, obesity, genital hypoplasia and mental retardation, was found. The patients also had abnormalities of the hips.