Relationship of the proper placement of tibial prosthesis with the restoration of knee function after knee arthroplasty

Kaijin GUO; Zhaoming CHENG; Lei LI; Bing ZHOU; Hanjun GUO; Liwen WANG

ABSTRACT

BACKGROUND:

The proper placement of the prosthesis during total knee arthroplasty(TKA) is a key factor that will affect the restored function of the knee.

OBJECTIVE:

To probe into the position and axial alignment of the tibial prosthesis in order to improve knee function and stability after TKA.

DESIGN:

A self-control study.

SETTING:

Orthopaedic department in the affiliated hospital of a university.

PARTICIPANTS:

A total of 12 patients(4 males and 8 females) received TKA due to severe osteoarthropathy or rheumatic arthritis in the Orthopaedic Departnent of the Affiliated Hospital, Xuzhou Medical College, from May 1999 to September 2004. One received bilateral TKA and 11 received unilateral TKA(4 in the left knee and 9 in the right knee).

METHODS:

TKA was performed in standard procedure and special attention was paid to the proper placement of the tibial prosthesis. Evaluation on lateral genual stability and HSS knee function was made before and after operation.MAIN OUTCOME

MEASURES:

① Lateral genual stability before and after TKA. ② Genual function scale ( concerning pain, function, range of motion, muscle strength, flexion deformity and stability).③X-ray observation.

RESULTS:

Knee-Society-Scores were evaluated in the 12 patients. Before TKA, 3 knees had mild lateral instability, 7 moderates and 2 severe instabilitys. After TKA, only one knee was mildly unstable and no knee had moderate or severe instability. The mean scores of HSS scale increased from 41 before operation to 89 after operation with the effective rate of 91.7% (11/12).

CONCLUSION:

The precise placement of tibial prosthesis can increase stability of the knee and relieve pain as well as improve knee function and motion.