Saddle joint

Abstract: In addition to the usual methods of arthroplasty of the carpometacarpal joint of the thumb an alternative technique of transosseus suspension for the first metacarpal is described. The basic idea is to reconstruct the intermetacarpal ligaments I-II with a distally pedicled slip of the flexor carpi radialis tendon to prevent proximal migration of the first ray after removal of the trapezium. This technique is considered simple, avoiding implantation of silastic or other material with their well known problems. Follow-up results of 97 patients out of a series of 151 operations between 1976 and 1982 are shown and discussed.

Abstract: Thumb saddle joint (A) comprises two shaft parts (1,2), for implantation, respectively, between the trapezium and the first metacarpal bone. Thumb saddle joint (A) comprises two shaft parts (1,2), for implantation, respectively, between the trapezium and the first metacarpal bone and, detachably connected to (2) and (1), respectively, a receptor part (3) with a spherical cup and a ball joint (5), for insertion in (3) and able to rotate in it during movement of the joint. The bottom edge (11) of (4) grips around the equator of (5).

Abstract: The thumb trapeziometacarpal joint is a saddle joint that is subject to high compressive forces during prehensile hand function. Fractures to the base of the thumb metacarpal occur commonly following axial load to a partially flexed thumb. Although reduction is easily performed, severe deforming forces act to displace the fractures into a varus and shortened position. Most extra-articular fractures can be treated with closed reduction and cast immobilization. Angulation up to 30 degrees can be tolerated because of the substantial compensatory motion at the thumb carpometacarpal joint. In Bennett fractures, good functional results are observed even with residual deformity and articular incongruity. However, the goal of treatment for intra-articular fractures should be the anatomic reduction of the joint surface with less than 1 mm of articular step-off to minimize the long-term risk of posttraumatic arthritis. Most Bennett fractures can be treated with closed reduction with percutaneous Kirschner wire fixation. Fractures with large Bennett fragments and Rolando fractures should be treated with open reduction and internal fixation to allow anatomic reduction with rigid fixation and early range of motion. Comminuted intra-articular fractures are challenging injuries that are best treated with application of an external fixator with limited open reduction and internal fixation, followed by bone grafting of metaphyseal bone defects if necessary.

Abstract: Primary arthritis of the thumb saddle joint is very common. Among the different treatment options, the implantation of a total joint arthroplasty is an alternative. The GUEPAR prosthesis, developed by a group of French surgeons, is mainly used in elderly patients and only in cases with preserved trapezial height. This study reports the mid-term results of the second generation of this implant. The clinical results show good pain relief and good mobility of the thumb. There were a few patients with radiological signs of implant loosening, but none of them had clinical problems. The advantage of a total replacement of the saddle joint, compared to the standard resection arthroplasty, is faster rehabilitation and preservation of the length of the thumb. The new generation of the GUEPAR prosthesis has a more anatomical metacarpal stem and a modularity which allows the fit of the implants according to the anatomical situation.