Abstract
Introduction:
For reconstructive surgery of the deteriorated rheumatoid MCP-joints silastic implants are used in general. Though realignment and stability after silastic joint replacement is achieved many disadvantages as reduced ROM, fractures and osteolysis are known. The first study of the cement less, non-constrained MCP-arthroplasty with HM-prosthesis showed a high rate of subluxation and synovitis.
Therefore the design of the HM-prosthesis was changed with a PE-head to avoid wear and an increase of the diameter of the phalangeal base of 30% to get more stability.
In prospective study we replaced 20 MCP joints in RA with this new designed prosthesis.
Material and Methods:
short-time results after a mean Fu-period of 6 month (2–12 month) are now reported. In all cases a total replacement was performed. Clinical and radiographic re-examination could performed in all cases.
Results:
In all cases we found an osteo-integration, no infection was seen. A luxation or subluxation as we have seen in the old design was not seen in any new designed prosthesis. In all cases pain-reduction was reported. The range of motion improved in all cases (flexion/extension 70/5/0).
Conclusion:
The results after changing the design of the HM-pros-thesis show an improvement of stability and show no wear, luxation or subluxation. The Improvement of mobility and pain-reduction is still seen as published in our studies before.
This first results have to be verified by longer FU-periods a higher number of patients.
