Tendon response to trauma and its possible clinical application. An experimental study in primates.

A study was undertaken to determine the response of tendon to trauma, and to establish the precise role of the intrinsic tendon cells vis-à-vis the paratendinous tissues in the healing process. It was found that tendon collagen has the ability to resist gross trauma and that tendons possess an inherent ability to regenerate and heal. The high rate of proliferation of synovial cells and the initial much lower rate of activity of intrinsic tendon cells have a direct bearing on the end result of the repair process. The principle of pre-stimulation of the tendon to improve the intrinsic vasculature and hence the rate and the quality of the healing process has been applied with promising, indeed striking, effect.

[Results of the use of the Austin Moore prosthesis for the treatment of femur neck fracture at Tygerberg Hospital. A retrospective study]. / Resultate van die Austin Moore-prostese in intrakapsulêre femurnekfrakture in Tygerberg-hospitaal. 'n Retrospektiewe ondersoek.

A retrospective study was done on 116 patients who received an Austin Moore prosthesis at Tygerberg Hospital between 1982 and 1983. The patients all had displaced intracapsular femoral neck fractures (Garden type III and IV). Although the Moore prosthesis must be fitted meticulously for good results, the operation can be performed effectively by the less experienced surgeon. This cementless monoprothesis is a good option for the elderly and/or poor-risk patient with a limited life expectancy. It has a low intraoperative mortality, a low percentage of re-operation and results in early and good mobilisation. In contrast to series on cemented prosthesis, we had a very low sepsis rate. In comparison to a total hip replacement, this is a much cheaper prosthesis and operation.

Methylprednisolone and the adult respiratory distress syndrome.

Total hip replacement was carried out on 22 patients under general anaesthesia. Of these, 10 were pretreated with methylprednisolone (30 mg/kg); 1 of these developed the adult respiratory distress syndrome (ARDS) and had high levels of thromboxane B2 (TXB2) 5 minutes after fixation of the femoral prosthesis and at the end of the operation. The other 12 patients served as controls; 5 of them developed ARDS and had statistically significant higher TXB2 levels than the other 7 control patients who remained well. All patients who did not develop ARDS had low TXB2 levels. TXB2 and beta-thromboglobulin levels followed the same trend and there was good correlation (r=0,6806; P less than 0,01) at the end of the operation in the control group patients who developed ARDS. There was no statistical difference in 6-keto-PGF1 alpha levels between the patients who developed ARDS and those in the control group who remained well. Steroids reduce arachidonic acid metabolism by inhibiting the release of substrate for cyclo-oxygenase and lipoxygenase activity. Patients prone to ARDS thus benefit from methylprednisolone administration.

The effect of ventilatory patterns on prostacyclin (PGI2) synthesis in the lung.

Prostacyclin (PGI2) appears to be synthesized in the lungs of man and experimental animals. It has been stated that PGI2 must be regarded as a local hormone that inhibits platelet adhesion to vessel walls only very close to the site of synthesis. The wide range of normal values given for PGI2 may be related to the sensitivity and exclusiveness of the different assay techniques used. In animals hyperventilation increases PGI2 synthesis by the lung, but in agreement with other authors we demonstrated that hyperventilation did not influence PGI2 synthesis in man. We used a radio-immunoassay technique to estimate PGI2 levels.

Primary tendon healing. An experimental study.

The management of a severed tendon within the digital sheath continues to present a formidable challenge. The major problem is one of excessive scar tissue formation. It was found experimentally in severed and partially divided tendons that the source of the blood supply, i.e. the vasculature in the tendon proper, will promote healing through the primary tissue (tenoblast) of the tendon itself, whereas the blood supply and granulation tissue from the damaged area of the flexor sheath leads to fibrous (scar) tissue formation. In this study of tendon repair special attention was paid to a suturing procedure which would have the least effect on the intrinsic blood supply to the severed ends. It was found that the basic requirement in successful tendon repair was to approximate and not to strangulate, and to minimize trauma to the flexor sheath which is the main source of scar tissue.