The effect of posterior cruciate ligament reconstruction on patellofemoral contact pressures in the knee joint under simulated muscle loads.
ABSTRACT The mechanism of cartilage degeneration in the patellofemoral joint (PFJ) and medial compartment of the knee following posterior cruciate ligament (PCL) injury remains unclear. PCL reconstruction has been recommended to restore kinematics and prevent long-term degeneration. The effect of current reconstruction techniques on PFJ contact pressures is unknown.
To measure PFJ contact pressures after PCL deficiency and reconstruction.
Eight cadaveric knees were tested with the PCL intact, deficient, and reconstructed. Contact pressures were measured at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion under simulated muscle loads. Knee kinematics were measured by a robotic testing system, and the PFJ contact pressures were measured using a thin film transducer. A single bundle achilles tendon allograft was used in the reconstruction.
PCL deficiency significantly increased the peak contact pressures measured in the PFJ relative to the intact knee under both an isolated quadriceps load of 400 N and a combined quadriceps/hamstrings load of 400 N/200 N. Reconstruction did not significantly reduce the increased contact pressures observed in the PCL-deficient knee.
The elevated contact pressures observed in the PCL-deficient knee and reconstructed knee might contribute to the long-term degeneration observed in both the non-operatively treated and PCL-reconstructed knees.
- SourceAvailable from: William Robert Walsh[show abstract] [hide abstract]
ABSTRACT: A computerised, real time, thin-film pressure transducer method is used to measure tibiofemoral contact area in total knee arthroplasty (TKA) devices that is easier and more reliable and reproducible as compared to the Fuji pressure-sensitive film technique. Many authors have suggested that contact areas and pressures within TKA devices can be a predictor of wear and failure of the ultra-high molecular weight polyethylene (UHMWPE) tibial insert. In this study, two contact area measurement techniques (Fuji pressure-sensitive Film and K-scan sensor system) were compared using a custom TKA testing jig designed for freedom of movement so that in any loading configuration the component found and seated in its own "home" position. The K-scan system was used to measure contact areas of one TKA design at several angles from 0 to 110 degrees flexion with loads equating to 4, 4.5, and 5 times body weight. For comparison, four ranges of Fuji film were used to measure areas at the same flexion angles but at 5 times body weight only. Contact areas measured with the Fuji films were 11-36% (p < 0.05) lower than those measured by the K-scan sensor.Journal of Biomechanics 09/1999; 32(9):951-8. · 2.72 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The long-term results of 25 patients treated nonoperatively with isolated posterior cruciate ligament (PCL) injuries were evaluated. Mean followup was 6.2 years (range, 2.2 to 16 years). All patients were evaluated both subjectively (questionnaire) and objectively (clinical examination, x-ray films, Cybex II dynamometer, and KT-1000 Knee Arthrometer). At followup, 80% of the patients were satisfied with their knees and 84% had returned to their previous sport (68% at the same level of performance, 16% at a decreased level of performance). Mean torque Cybex II quadriceps values for three velocities of testing (45, 90, and 180 deg/sec) in patients fully returned to sport and satisfied with their knees was greater than 100% of uninvolved quadricep; conversely, those not satisfied with their knees all had values less than 100% of uninvolved knee. The amount of knee instability as determined by the KT-1000 Arthrometer was not related to the patient's return to sport nor to knee satisfaction. We concluded that the majority of athletes with isolated PCL injuries who maintain strength in musculature return to sports without functional disability.The American Journal of Sports Medicine 01/1986; 14(1):35-8. · 4.44 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: With adequate quadriceps exercises, the prognosis of a ruptured posterior cruciate ligament can be greatly improved. Of the 116 cases followed in this report, 55 were sports injuries while most of the remainder were traffic accidents. An excellent or good result was obtained in 47 sports-injured patients, while only 5 involved in road trauma obtained this result. Surgery was used to improve the eventual result and this was successful in nine cases. Early repair is still the treatment of choice. Eighty percent of ruptures can have a good or excellent result with effective management.The American Journal of Sports Medicine 01/1984; 12(4):292-7. · 4.44 Impact Factor