Artikel
Why do we need the 3D knee™?: first experiences with the new prosthesis design
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Veröffentlicht: | 13. Juni 2005 |
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Gliederung
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Regaining normal levels of functional strength and range of motion remain significant challenges in total knee arthroplasty. Many studies have demonstrated a link between prosthesis design and patient function. Based on in vivo kinematic studies and retrieved implant analysis, a data driven design, the 3D KneeTM prosthesis (Encore Medical, Austin, TX) was designed with the goal of providing better patient strength, improved range of motion, and enhanced durability. This fixed-bearing total knee prosthesis incorporates a hemispherical lateral condyle and tibial articulation to provide definitive ap. translation control while freely allowing endo-exo-rotation.
The purpose of this evaluation was to quantify the first clinical, gait and kinematic performance of the patients retaining the 3D KneeTM in a single-surgeon case series.
Clinical data were gathered from 31 patients 12 months after surgery.
Gait laboratory studies using motion analysis, force platforms and surface electromyography and fluoroscopic examination were performed.
Average pre-op Knee Society Knee/Function scores were 45±15/48±13 and improved to 94±10/92±13 post-op. Range of motion increased from an average of 104°±9° pre-op to 118°±11° post-op. 55% of the knees had greater than 120° flexion. There were no statistically significant differences in knee kinematics during the gait or step-over activities comparing the normal and operated knees.
Clinical scores are equivalent or better than experienced with previous devices in the same clinic. Maximum flexion in this PCL retaining design is equivalent to the best performing posterior stabilized knee arthroplasty. Studies are ongoing to provide mid-term outcomes with the prosthesis designed to achieve enhanced functional performance.