Comparison of midvastus and standard medial parapatellar approaches in total knee arthroplasty

Peiliang FU; Xiaohua LI; Yuli WU; Qingyun XIE; Jiuyi SUN; Haishan WU

ABSTRACT

BACKGROUND:

Some overseas searchers have shown that,the midvastus approach in total knee arthroplasty(TKA)can reserve the complete medial structure of quadriceps femoris,improve the functional recovery of knee extension apparatus,but also preserve the blood supply of medial knee joint and maintain proprioceptive sense of knee joint.

OBJECTIVE:

To evaluate the early functional outcome of midvastus approach and standard medial parapatellar approach in TKA.

DESIGN:

A prospective,randomized,double-blind,comparative study.

SETTING:

Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA.

PARTICIPANTS:

From March 2004 to March 2006,34 patients undergoing bilateral TKA simultaneOusly were admitted to the Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA,including 7 males and 27 females.They aged 56-78 years with a mean of 70.5 years,and consisted of 24 cases with osteoarthritis,and 10 cases with rheumatoid arthritis;24 cases with bilateral genu varum,9 cases with bilateral enu valgum,and 1 case with lateral genu varum and contralateral genu valgum.Informed consents were obtained from all the included patients.MaterialsPress Fit Condylar(PFC)Sigma knee prosthesis(DUPUY Company),the central tibial pad was added with a polyethylene prominence,while the corresponding femoral prosthesis was treated with anterioposterior steotomy,identical with the remained prosthesis.

METHODS:

The surgical approach of 34 patients was randomized into a midvastus approach in one knee and a standard medial parapatellar approach in the other knee.The comparison included the surgical parameters and clinical parameters.mevemnt,the time of performing an active straight leg raise,the time of reaching 90°knee flexion,range of motion and complications.

RESULTS:

All of 34 patients were involved in the result analysis.There was no significant difference in the surgical time botween the two roups.The assessment revealed significantly less blood loss[(286±29.8)Ml,(368±35.8)Ml,P＜0.05],fewer lateral release in valgus knee(20%,50%,P＜0.05),less pain in the first week(P＜0.05),earlier return of active straight-leg raise[(1.8±0.3)days,(4.5±0.8)days,P＜0.01],earlier reach of 90° knee flexion [(3.2±0.8)days.(7.1±1.2)days,P＜0.01]and greater range of motion at 45 day[(107±20)°,(98±12)°,P＜.05]in the midvastus approach group.

CONCLUSION:

The midvastus approach,which is based on diminished disruption of extensor mechanism and peripatellar pIexus of vessels,relieves pain and improves range of motion in the early rehabilitation period following TKA.