In a prospectively randomized study including 68 patients, the results of inside-out horizontal meniscus suturing were compared to meniscus repair using the meniscus arrow. 96% of the patients underwent re-arthroscopy after 3-4 months. Only lesions in the red/red or red/white areas were included. Patients were treated with a hinged brace for 9 weeks. 30 patients had an isolated bucket-handle lesion. In 19 cases the repair was done in conjunction with an ACL reconstruction and in 19 cases the repair was performed in an ACL-insufficient knee. The two groups were comparable. Operating time in the arrow group was one half that of the suture group. Of 65 re-arthroscopies, 91% of the patients had healed or partially healed in the arrow group compared to 75% in the suture group (P = 0.11). In only 50% of the non-healed cases was this clinically suspected prior to control arthroscopy. The difference between healing in ACL-reconstructed and ACL-insufficient knees was not significant. Two patients in the suture group had a deep infection. There were no serious neurovascular injuries. Five patients in the suture group and two patients in the arrow group had symptoms in the saphenous nerve area. All patients had some synovial irritation at control arthroscopy but no severe reactions to suture or arrows were seen. Short-term results with meniscus arrows, based on healing and evaluated by second-look arthroscopy, seem promising.

No abstract

We used 10 cadaver knees to estimate the safe pressure during arthroscopy by measuring the volumes and pressures of irrigation fluid at different flexion angles. Maximum volumes could be contained at 35 degrees of flexion. Pressures of 200 to 450 mmHg were measured, and all the knees ruptured by extension or flexion after they were filled to 100 mmHg at 35 degrees of flexion. Fifty milliliters of irrigation fluid had to be removed if the pressure remained constant when extending from 35 degrees and 70 ml when flexing to 90 degrees. Totally, 100 ml irrigation fluid had to be removed when flexing from 35 degrees to 120 degrees. Our investigation indicates that a pressure of 150 mmHg can be tolerated by all knees. Both flexion and extension from the 35 degrees position must be done gently and slowly using a large bore, wide-open inflow and outflow tubes allowing egress of irrigation fluid to prevent capsular rupture, extravasation of irrigation fluid, vascular compromise, or compartment syndrome.

Displacement from human plasma proteins of lidocaine by disopyramide was investigated in serum from nine patients receiving lidocaine treatment because of severe ventricular arrhythmias. From each patient disopyramide in concentrations of 5.9 and 14.7 mumol/l was added to three different serum concentrations of lidocaine and the displacement was examined. At a serum concentration of disopyramide of 14.7 mumol/l the percentage of unbound lidocaine increased from 30.4 +/- 0.2 to 36.3 +/- 0.2% (mean +/- S.E.M., P less than 0.001) at an average total serum concentration of lidocaine of 22.7 mumol/l. The study implies a stronger binding affinity of disopyramide than lidocaine to alpha-1-acid glycoprotein. We recommend caution when using disopyramide immediately after an infusion of lidocaine. With the dosage regimen used serum concentrations considerably above the suggested therapeutic level were achieved in the majority of patients.