The relationship between the pressure adjacent to the ulnar nerve and the disease causing cubital tunnel syndrome.

We investigated the relationship between cubital tunnel pressure in patients with cubital tunnel syndrome with osteoarthritis and those without osteoarthritis. We studied 31 elbows in 29 patients. We divided the patients into two groups: one associated with osteoarthritis and the other not associated with osteoarthritis. In the latter group, there was ulnar nerve subluxation in 10 elbows and cubitus valgus in 3. Cubital tunnel pressure was measured intraoperatively with a fiberoptic microtransducer. The extraneural pressure with the elbow flexed was significantly increased in patients with osteoarthritis and those without osteoarthritis. The pressure within the cubital tunnel in osteoarthritic elbows was significantly higher than that in those without osteoarthritis. Moreover, the pressure of osteoarthritic elbows significantly increased from proximally to distally within the cubital tunnel, whereas the pressure in elbows without osteoarthritis was high only proximally. Thus, cubital tunnel pressure could be a more important causative factor for cubital tunnel syndrome in the elbows with osteoarthritis than in those without osteoarthritis.