[Failure and complications of saddle-joint arthroplasty].

Two different or general types of arthroplasty for treatment of the saddle-joint-arthrosis are usual: particular bone-resection (base of first metacarpal or part of the trapezium) or complete resection of the trapezium, both combined with an interposition. The last one is essentially used in carpometacarpal arthroplasty. Two main groups are known: tendon-interposition and silastic prostheses. Most authors describe the dislocation of the first metacarpal, followed by pain and instability, in 20% of all cases. Neglecting of the ligament conditions seems to be the mainfault. In nearly all cases the ligaments can be found destroyed or elongated. Functional reconstruction is difficult or impossible, therefore a tendon-plasty should be done to restore the function of the ligaments. Some other mistakes and complications are reported. Planning a saddle-joint-arthroplasty they should be known as the best protection against bad results.