Summary
The behaviour of the contact system was studied in 40 patients with total hip arthroplasty,
by measuring plasma prekallikrein, spontaneous kallikrein activity and factor XII.
In the literature it had been shown that patients with complications from this operation
had decreased prekallikrein and increased kallikrein activity (M. Nakahara. Acta orthop
scand 1982; 53: 591-6). In the present study, comprising patients with and without
pain and proven loosening of the hip prosthesis, these findings could only partially
be confirmed. Patients with a loosened prosthesis had significantly lower prekallikrein
(mean 0.78 ± 0.28 U/ml; p <0.01) than patients without problems, but no detectable
kallikrein activity in plasma. Patients with pain but no loosening had normal prekallikrein
(1.04 ±0 0.26 U/ml) and also no demonstrable kallikrein activity. Factor XII was normal
in all patient groups. It is concluded that decreased prekallikrein is limited to
patients with a loosened hip prosthesis, with or without pain.
Keywords
Factor XII - Kallikrein activity - Loosened prosthesis - Prekallikrein - Total hip
arthroplasty