Clinical Outcomes After Total Hip Arthroplasty Using Direct Anterior Approach Versus Direct Lateral Approach In The Lateral Decubitus Position

Objective:To compare the clinical outcomes of direct anterior approach and direct lateral approach in total hip arthroplasty.Methods:A prospective randomized study was performed on 66 patients who received primary unilateral total hip arthroplasty from November 2017 to April 2019.66 patients were randomly divided into two groups:one group underwent operation through direct anterior approach(DAA group)and the other group underwent operation through direct lateral approach(DLA group).DAA group:29 cases of hip osteoarthritis,4 cases of femoral head necrosis,16 males and 17 females,18 of the left hip joints and 15 of the right hip joints,the age was 66.2±5.9 years old,the Body Mass Index(BMI)was23.9±3.2kg/m~2,the preoperative Harris Hip Score(HHS)was 55.8±5.1.DLA group:30cases of hip osteoarthritis,3 cases of femoral head necrosis,15 males and 18 females,16of the left hip joints and 17 of the right hip joints,the age was 67.8±6.8 years old,the BMI was 24.1±3.1kg/m~2,the preoperative HHS was 54.4±5.7.Data gathered included the incision length,operation time,intraoperative blood loss,the leaving bed time,the presence of complications,types of complication were compared.The pain Numerical Rating Scale(NRS)was recorded 24 hours and 48 hours after surgery.The HHS was administered to the patients 1 week,1 month and 6 month after surgery.Results:All patients were followed up for 6-12 months,with an average of 8.6 months.The incision length was 9.9±0.9cm in DAA group and 12.6±1.0cm in DLA group,which showed significant difference between the two groups(P<0.001).The incision length in DAA group was shorter than that in DLA group.The operation time was 110.7±13.9min in DAA group and 102.1±13.2min in DLA group,which showed significant difference between the two groups(P<0.05).The operation time in DAA group was longer than that in DLA group.The intraoperative blood loss was 236.8±55.8ml in DAA group and261.1±68.5ml in DLA group,which showed no difference between the two groups(P>0.05).The leaving bed time was 30.5±4.6h in DAA group and 33.9±6.2h in DLA group,which showed significant difference between the two groups(P<0.05).The leaving bed time in DAA group was shorter than that in DLA group.The pain NRS score 24 hours postoperatively was 3.8±0.8 in DAA group and 4.3±0.9 in DLA group,which showed significant difference between the two groups(P<0.05).The pain NRS score 48 hours postoperatively was 3.4±0.7 in DAA group and 3.8±0.7 in DLA group,which showed significant difference between the two groups(P<0.05).The pain NRS score 24 hours and 48 hours postoperatively in DAA group were lower than those in DLA group.The HHS 1 week postoperatively was 60.8±4.5 in DAA group and 58.4±4.6 in DLA group,which showed significant difference between the two groups(P<0.05).The HHS 1month postoperatively was 76.2±5.2 in DAA group and 72.1±4.2 in DLA group,which showed significant difference between the two groups(P<0.001).The HHS 1 week and1 month postoperatively in DAA group were higher than those in DLA group.The HHS6 months postoperatively was 90.1±3.6 in DAA group and 88.8±4.1 in DLA group,which showed no significant difference between the two groups.The HHS at 1 week,1 month and 6 months postoperatively in both groups were significantly superior to the preoperative HHS(P<0.001).One case of superficial wound infection observed in the DLA group and one case of nerve damage observed in the DAA group and no other complications such as dislocation,periprosthetic fracture observed in either group which showed no significant difference between the two groups in the complications.Conclusions:Compared with the DLA group,the DAA group showed significant longer operation time,shorter incision length,shorter leaving bed time,lower pain NRS score,higher HHS at 1week and 1 month postoperatively.But we found no difference between the two groups in the intraoperative blood loss and the HHS at 6 months postoperatively.It is suggested that patients undergoing total hip arthroplasty through DAA have mild pain,quick postoperative recovery and better early postoperative hip function,but the long-term efficacy remains to be further observed.