A biomechanical study in vitro has evaluated a new modification of the core and peripheral suture technique for flexor tendon repair. Groups of repairs were conducted in cadaver tendons, using a core suture alone, a core suture with a simple running surface suture and a new modification involving a 'Halsted' horizontal mattress technique for the peripheral stitch. The Halsted modification increased the load at which a visible gap formed by 93%, the load at which a 2 mm gap formed by 77%, and the maximum strength by 89%. This increase was due to the technique; it did not depend on the suture material used. The bulk of the tendon repair was not significantly greater with the Halsted modification.

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Using dried bones which could be tilted and rotated, we assessed the accuracy of published radiographic methods for measuring the migration of prosthetic acetabular components and compared the results with a new method. The new line linking acetabular margins was significantly more accurate for proximal migration than the teardrop, the sacroiliac line or the sacroiliac-symphysis line. For medial migration, a new line tangential to the brim and through the horizontal mid-point of the obturator foramen was more accurate than Kohler's line, the ilio-ischial line or the iliopubic line. In combination, the two new lines can give a more accurate assessment of acetabular erosion than previous methods, since they are less affected by the differences in rotation commonly found in a series of radiographs.

Cadaveric acetabula were mounted in a hip simulator and the friction developed in each during articulation with a series of metal femoral head prostheses of differing sizes was measured. In a separate study, assembled Hastings bipolar hip prostheses were subjected to weight-bearing forces in the same acetabula and their self-righting mechanism was observed. The self-righting mechanism was found to function efficiently, in most cases overcoming the combined friction of the inner and outer articulations of the Hastings hip. However, during motion in the hip simulator a wide variation of friction was observed between different acetabula and within the same acetabulum with differing head size. In several cases this acetabular friction was found to be less than the friction in the inner articulation of the Hastings bipolar hip prosthesis, and this may explain some cases of reported failure of biarticular function.