Preliminary clinical effects of total knee arthroplasty with iASSIST navigation system / 中华骨科杂志

ABSTRACT

Objective To explore the application value of iASSIST portable navigation in total knee arthroplasty.Methods Seventy-four patients with knee osteoarthritis from April 2016 to April 2017 were retrospectively recruited.Thirty-seven patients (37 knees) underwent TKA with iASSIST navigation,while 37 patients (37 knees) underwent conventional TKA.Five parameters were measured on the weight-bearing radiographs at six months after TKA,including mechanical axis (MA),mechanical lateral distal femoral angle (mLDFA),mechanical medial proximal tibial angle (mMPTA),sagittal femoral component angle (sFCA) and sagittal tibial component angle (sTCA).Duration of operation,blood loss volume,postoperative hospital day,Western Ontario and McMaster Universities (WOMAC) osteoarthritis index,Knee Society Score (KSS) clinical score and functional score at 6 weeks,12 weeks and 24 weeks after surgery were also recorded.Results The accuracy of MA (180.85°±0.88° versus 182.23°±1.09° in the conventional group,P＜0.05),mLDFA (90.52° ±0.78° versus 91.09° ±0.96° in the conventional group,P＜0.05),and mMPTA (90.34°± 1.25° versus 91.13°± 1.46° in the conventional group,P＜0.05) was improved significantly in navigation group.The WOMAC osteoarthritis index at 6 weeks postoperatively in the navigation group and in the conventional group were 58.54±1.45 and 56.54± 1.77 respectively.The KSS clinical score in the navigation group and in the conventional group were 53.14± 1.13 and 49.35± 1.11 respectively.The KSS functional score in two groups were 61.24± 1.30 and 59.81 ± 1.29 respectively (P＜0.05).The WOMAC osteoarthritis index at 12 weeks postoperatively in the navigation group and in the conventional group were 43.54± 1.19 and 41.92± 1.42 respectively.At 12 weeks,the KSS clinical score in two groups were 67.11 ± 1.51 and 62.08± 1.46 respectively.The KSS functional score in two groups were 68.14±1.11 and 66.38±1.26 respectively (P＜0.05).The blood loss volume in the navigation group and in the conventional group were 113.11±57.29 ml and 147.57±68.77 ml respectively (P＜0.05).There were no significant difference in the duration of operation,postoperative hospital day,WOMAC osteoarthritis index,knee clinical score and functional score at 24 weeks postoperatively between two groups (P＞0.05).Conclusion More accurate restoration in mechanical axis and optimal implantation can be achieved with the help of iASSIST navigation.This navigation system can also achieve better knee function in the early stage after TKA.