Carpal bone mechanics are complex and poorly understood. An anatomic model that explains observed kinematic results is yet to be achieved. The aim of this study is to determine if morphologic sub-typing of the STT and TH joints exists.

The study used 100 sets of dry disarticulated carpal bones and 50 cadaveric wrists. A digital microscribe was used to reconstruct and measure the articular surfaces of the STT and TH joints and distal lunate of all specimens. Ligaments were dissected, reconstructed and measured. Lunate typing based on the morphology of the distal articular surface allowed the specimens to be split into three groups: type one lunates (single facet; 30%), type two lunates (double facet; 42%) and unclear (intermediate; type three; 28%).

Type one and type two groups had significantly different (p < 0.05) mean measures at the STT and TH joints, suggesting clear differences in joint shape and hence joint motion. Type three had mean measures that were not significantly different (p>0.05) from either of the other groups. Two distinct ligament patterns were also observed. The mean measures of each ligament were significantly different (p< 0.05) between type one and two specimens. Type three specimens were split into those with a ligamentous pattern similar to type one specimens and those similar to type two, each significantly different from each other (p< 0.05). Type one specimens had ‘sling-like’ supports for either side of the wrist, whilst type two specimens had numerous attachments to the scaphoid and hamate, creating potential points of rotation.

These results suggest that bony typing gives a clear indication of potential carpal motion for 72% of cases. The remaining 28% are reliant upon ligamentous typing. Individuals are predisposed to structurally support one pattern of motion. Further investigation will relate these anatomic differences to observable motion.

Aims: To compare the vastus muscle-splitting approach and the classical medial parapatellar in total knee replacement. Methods: Prospective clinical and radiographic study in 50 cemented cruciate-retaining prostheses (Interax, Stryker-Howmedica-Osteonics): midvastus approach in 25 and parapatellar medial in 25. Results: There were no differences (p> 0.05) in postoperative femoro-tibial or patelar tilt angles, duration of surgery, drainage bleeding, Hemoglobine and Hematocrite at postoperative day 3, units of blood transfused, complications, hospital stay, range of motion, and score of the American Knee Society at 1, 6, 12 or 24 months. However, the midvastus approach showed less intraoperative lateral retinacular releases, more patients were able to get independent terminal knee extension at postoperative day 5, and the range of motion at discharge was higher (p< 0.05). Conclusions: The midvastus splitting approach can reduce the need to perform lateral retinacular releases, with advantages in the early postoperative range of motion and knee extension ability.

The purpose of this paper is to call attention to the anterior bone block method of Hybbinette-Eden for recurrent dislocation of the shoulder joint.

1. The operative technique is not difficult, and the after-treatment is short and relatively agreeable for the patient.

2. Sixty of our own cases are described, with four recurrences. The recurrences all occurred as the result of real trauma. In a total of 128 Scandinavian cases there were eight recurrences—that is 6·3 per cent.

3. In our opinion, based on the observations of radiography, arthrography, and operation, it is the compression fracture of the head of the humerus which deserves the name "essential lesion." Destruction of the anterior rim of the glenoid may be very slight, or entirely lacking. No false joint cavity or rupture big enough to receive the head of the humerus was ever observed by arthrography or by inspection during operative exploration.

Recurrent dislocation is an intracapsular subluxation, which occurs when the anterior rim of the glenoid slides into the hollow in the humeral head.