Comparison of reconstruction of the anterior cruciate ligament with and without a Kennedy ligament-augmentation device. A randomized, prospective study.

In a randomized, prospective study, sixty-four patients who were operated on for a torn anterior cruciate ligament were divided into two groups: thirty patients (the control group) had repair with the Marshall-MacIntosh technique alone, and thirty-four patients had repair with the same technique but with the addition of a Kennedy ligament-augmentation device. The preoperative characteristics were essentially identical in the two groups. The postoperative management, resumption of athletic activities, and occurrence of complications were also similar. All patients were followed for more than two years. No significant functional or clinical difference between the two groups was found with respect to residual laxity determined either from dynamic radiographs or with the KT-1000 arthrometer. There was no evidence that the addition of the Kennedy ligament-augmentation device gave results that were superior to those obtained with the Marshall-MacIntosh technique alone.

Effects on intact femora of dogs of the application and removal of metal plates. A metabolic and structural study comparing stiffer and more flexible plates.

Studies of flexible plates made of plastic have shown that less osteoporosis develops beneath them than beneath rigid metal plates. However, to date plastic plates of appropriate physical properties and biocompatibility are not available for use in humans. To determine if a similar beneficial effect could be obtained using metal plates, the effects of thick chromium cobalt plates were contrasted in experiments in dogs with the effects of thinner plates of similar design made of titanium, 6-aluminum, 4-vandium. A significant reduction in the osteoporosis was obtained by use of the more flexible plates. Following plate application a delayed, massive, transient stimulus to bone formation occurred endosteally, periosteally, and intracortically. Despite this, a substantial decrease in bone mass occurred, primarily mediated by endosteal bone resorption. Intracortical porosity played little or no role in net bone loss. The major effects subsided by six months. Recovery after plate removal was predominantly the result of endosteal new-bone formation.

Topical hemostatic agents for bone bleeding in humans. A quantitative comparison of gelatin paste, gelatin sponge plus bovine thrombin, and microfibrillar collagen.

The three topical hemostatic agents--gelatin paste, microfibrillar collagen, and gelatin sponge soaked in thrombin--individually were effective in reducing bleeding from cancellous bone, as tested on the femoral surface of trochanteric osteotomies during total hip replacement. During a three-minute interval, the spontaneous reduction in bleeding in eight control hips to which no agent was applied was 11 per cent. Gelatin paste gave a reduction of 85 per cent; gelatin sponge soaked in thrombin, a reduction of 75 per cent; and microfibrillar collagen, a reduction of 47 per cent. None of these agents interfered with healing of the trochanteric osteotomy.