Cruciate-retaining Prosthesis Research Articles

Kinematic total knee arthroplasty: A 10- to 14-year prospective follow-up review

To understand better the type and incidence of long-term complications in total knee replacement, 306 primary Kinematic total knee arthroplasties performed between June 1978 and December 1982 were prospectively reviewed in detail. The Kinematic knee is a nonconstrained, posterior cruciate-retaining prosthesis that has right and left femoral components to afford anatomic tracking of the patella. The overall revision rate was 6.5%. The most common cause for revision surgery was patellar complications. Ten revisions (3.06%) were for patellar component loosening. Two knees were revised for patella subluxation (0.65%); 1 was in a resurfaced rheumatoid patella, and 1 in an unsurfaced osteoarthritic patella. Stair climbing was better with an unsurfaced patella. Anterior knee pain was 21.8% in the unsurfaced patella and 11.2% in the replaced patella. These data suggest patella replacement is not appropriate with this design.

A comparison of isokinetic strength testing and gait analysis in patients with posterior cruciate-retaining and substituting knee arthroplasties

Fourteen patients with a posterior-stabilized prosthesis in one knee and a posterior cruciate-retaining prosthesis in the contralateral knee and both scoring good or excellent on the Hospital for Special Surgery (HSS) knee scale were evaluated by isokinetic muscle testing and comprehensive gait analysis at a mean follow-up of 98 months after arthroplasty. The average HSS knee score (93 points) and the average Knee Society score (94 points) were the same for the cruciate-retaining and posterior-stabilized knees. No differences were noted between the cruciate-retaining and the posterior stabilized knees with respect to isokinetic muscle testing parameters (peak torque, endurance, angle of peak torque, and torque acceleration energy) for both quadriceps and hamstrings. No significant differences were found between the cruciate-retaining and the posterior-stabilized knees with regard to gait parameters, knee range of motion, and electromyographic waveforms during level walking and stair climbing. Cruciate-retaining and posterior-stabilized total knee prostheses perform equally well during level gait and stair climbing.

Comprehensive gait analysis in posterior-stabilized knee arthroplasty

Sixteen patients implanted with a posterior-stabilized prosthesis (Insall-Burstein PS II, Zimmer, Warsaw, IN) and 32 age-matched control subjects were evaluated by isokinetic muscle testing and comprehensive gait analysis at a mean 46 months following the index arthroplasty. The contralateral knee was normal in 13 patients and an asymptomatic total knee arthroplasty in 3 patients. No significant differences ( P > .05) were found between the study and control groups in spatiotemporal gait parameters nor were there isokinetic strength deficits. A prolonged firing of the vastus medialis was observed in some patients. Knee range of motion during level walking and stair descent was decreased significantly ( P < .05) in the study group. There was no significant difference for knee range of motion between the study and control groups during stair ascent. Spatiotemporal gait parameters in the total knee arthroplasty patients show no significant differences from the control subject at nearly 4 years after surgery. However, other gait abnormalities are present and cannot be accounted for on the basis of muscle weakness, abnormal phasic muscle activity, or inadequate knee range of motion. With reference to historic control subjects, the persistent gait abnormalities of patients implanted with posterior-stabilized prostheses (posterior cruciate substituting) are comparable to those of patients implanted with cruciate-retaining prostheses and superior to cruciate-sacrificing prostheses.

Posterior cruciate function following total knee arthroplasty: A biomechanical study

The strain developed in the posterior cruciate ligament (PCL) of eight fresh cadaveric knees was measured before and after total knee arthroplasty using a loading technique that simulated stair ascent and descent. Each knee was instrumented with a Hall Effect strain gauge (Micro-Strain, Burlington, VT) in the PCL, a load cell in the quadriceps tendon, an electrogoniometer, and an array of linear displacement transducers to measure femoral rollback. Testing was undertaken with each knee in its normal state with the anterior cruciate cut and with a cruciate-retaining prosthesis, a cruciate-excising prosthesis, and a cruciate-substituting prosthesis. Normal PCL strain levels were produced in only 37% of the trials following implantation of the cruciate-retaining knee arthroplasties. With a cruciate-retaining prosthesis, femoral rollback decreased by an average of 36% and was associated with a 15% loss in extensor efficiency. In the procedures performed with excision of the PCL, rollback decreased by 70% and extensor efficiency by 19%. Cruciate substitution resulted in a 12% loss in rollback and an 11% decrease in extensor efficiency. The strain developed within the PCL during knee flexion was found to be extremely sensitive to the thickness of the polymeric tibial insert. In the majority of cases, it was not possible to restore normal ligament loading with flexion while simultaneously maintaining acceptable varus/valgus stability of the knee joint. Using a range of contemporary knee arthroplasties, the authors were unable to consistently reproduce normal function of the PCL.