[Results of total knee prostheses with or without preservation of the posterior cruciate ligament].

PURPOSE OF THE STUDY

This study was undertaken to assess the functional repercussion of retention or sacrifice of the posterior cruciate ligament in total knee replacement.

MATERIAL

Two homogeneous randomised series of 24 cases were matched. They concerned primary total knee arthroplasty for osteoarthritis using the same prosthetic design. In case of sacrifice of the posterior cruciate ligament, the prosthesis included a substitution system constituting the only difference between the two types of implants (the design of trochlea, femoral condyle and tibial plateau were identical).

METHODS

Functional assessment was performed according to the Hospital for Special Surgery score, at a minimal follow up of 12 months. The Student "t" Test was used for statistical analysis.

RESULTS

In cases with posterior cruciate retention, the mean HSS score was 86.6. In postero-stabilised cases. this score was 87.7: a non significant difference. The mean range of flexion was 108 degrees for the retaining cases versus 113 degrees for the postero-stabilised ones: a non significant difference.

DISCUSSION

The functional outcome seems to be the same whether a postero-stabilised or a posterior cruciate retaining total knee prosthesis was used. The latter technique requires more care for ligament balancing, tibial cuts and exposure.

CONCLUSION

The authors believe that there is no benefit to expect at mid-term follow up from retaining the posterior cruciate ligament in total knee replacement.