Repair of peripheral meniscal tears: open versus arthroscopic technique.

Tears in the peripheral vascular zone of 71 menisci in 68 knees were repaired by us from 1978 to 1986. The meniscus repair was done by open arthrotomy in 26 cases and by arthroscopic techniques in 45 cases. We have assessed the relative efficacies of open and arthroscopic repair techniques. The results were compared in knees with and without anterior cruciate laxity. The indications for meniscal repair included unstable peripheral detachments and longitudinal tears of the outer third of the meniscus. Open repair was performed by a posteromedial arthrotomy incision. Arthroscopic repair was done using the double-lumen guide system with a limited posterior incision for retrieval of needles. We have found that the arthroscopic technique is easier to perform than the open repair because some tears are too far inside the rim to lend themselves to open suture. The average follow-up is 4 years, 2 months, with a range of 2-10 years. There have been no neurologic or vascular injuries from either technique. Twenty-five patients have had a repeat arthroscopy. The overall failure rate was 9.8%. The difference between the failure rate of 11% in the open-repair group and 8.8% in the arthroscopic repair group was not statistically significant. The failure rate in anterior cruciate-stable knees was 8% versus a 13% failure in cruciate-deficient knees. We conclude that both open and arthroscopic meniscus repair techniques are safe and effective with few complications in both stable and unstable knees. Anterior cruciate ligament stability is ideal, but it is not mandatory for a successful result.

Electrical stimulation in the treatment of idiopathic scoliosis.

Sixty-two fully compliant patients (with 94 curves) met protocol criteria of 20 degree-39 degree curves, Risser iliac crest signs of 0, 1, or 2, and no prior treatment. Both clinical and roentgenographic examinations were performed before, during, and after treatment. The follow-up periods averaged 2.3 years, with a 3.2-year average follow-up period for patients who completed, rather than failed, Electro Spinal Orthosis (ESO) treatment. Seventy-one percent of the 20 degree-29 degree curves and 66% of the 30 degree-39 degree curves had progressed 5 degrees or more at follow-up evaluation. Fifty percent of the patients had a follow-up curve of at least 40 degrees or were treated by posterior spinal fusion and were considered treatment failures. The curve progression paralleled that found in natural history studies, and the rate of failure exceeded that found in orthotic treatment studies.

Behavioural estimates of auditory thresholds in hens.

Six hens were trained in a trial-by-trial auditory discrimination in which trials were signalled by the lighting of two key lights. Correct responses (left-key pecks when a tone was presented and right-key pecks when it was not) produced intermittent deliveries of food. Following training at one tone frequency and intensity, testing sessions at lower intensities were carried out. Training and testing were repeated for 10 frequencies between 260 Hz and 8000 Hz. Derived measures of detection performance allowed estimates of the intensities at which no discrimination would have occurred. The threshold measures are presented and suggest that the range of most sensitive hearing was between 3000 and 5000 Hz.