Effect of exogenous thyroxin on renal ion-regulating and acid-secreting functions in white rats

Experimental hyperthyreosis was stimulated by intraventricular injections of sodium solithyroxin (T4) suspension on 1% starch gel during 10 days at a dose of 10 microg/100 g of body mass (n = 15) or 20 microg/100 g of body mass (n = 15). Renal function was tested by 5 % water loading after 24 hrs. since the last T4 injection. Urine and blood plasma samples were analyzed for creatinine; in addition, urine was analyzed for sodium and potassium ions of titrated acids, ammonium cations, and pH. Thyroxin was found to decrease creatinine clearance and expedite renal excretion of sodium and potassium ions irrespective of the amount of exogenous T4; at the same time, exaggerated excretion of titrated acids and ammonium cations correlated with T4 dose.     

Tendon Graft—Ulna Fixation in Distal Radio-Ulnar Joint Stabilisation; Biomechanical Comparison of Three Graft-Bone Fixation Methods

A common distal radio-ulnar joint (DRUJ) stabilisation procedure uses a tendon graft running from the lip of the radial sigmoid notch to the ulnar fovea and through a bony tunnel to the ulnar shaft, before being wrapped round the distal ulna and sutured to itself. Such graft fixation can be challenging and requires a considerable tendon length. The graft length could be reduced by fixing the graft to the ulna using a bone anchor or interference screw. The aim of this study was to compare the strength of three distal ulna graft fixation methods (tendon wrapping and suturing, bone anchor and interference screw). Four human cadaveric ulnae were used. A tendon strip was run through a tunnel in the distal ulna and secured by: (1) wrapping round the shaft and suturing it to itself, (2) a bone anchor and (3) an interference screw in the bone tunnel. Load to failure was determined using a custom-made apparatus and an Instron machine. Maximum failure load was highest for the bone anchor fixation (99.3 ± 23.7 N) followed by the suturing (96.2 ± 12.1 N), and the interference screw fixation (46.9 ± 5.6 N). There was no significant difference between the tendon suturing and bone anchor methods, but the tendon suturing was statistically significantly higher compared to the interference screw (P = 0.028). In performing anatomical stabilisation of the DRUJ fixation of the tendon graft to the distal ulna with a bone anchor provides the most secure fixation. This may make the stabilisation technique less demanding and require a smaller tendon graft.