Advantages of performing bilateral total hip arthroplasty (THA) in one stage include a single hospital stay, a single exposure to anaesthesia risks, and expedited rehabilitation. Controversy persists however, regarding safety, notably morbidity and mortality rates. Importantly, few studies have compared the anterior to the posterior approach for single-stage bilateral THA (1B-THA). The objective of this retrospective study in a uniform patient population was to compare the anterior and posterior approaches for 1B-THA in terms of: 1) early mortality rates, 2) early complications, 3) and 90-day re-admission rates, hospital stay lengths, and blood loss.

1B-THA in patients younger than 80 years who have an ASA score of 1 or 2 is associated with no early mortality and with low early morbidity rates regardless of whether the anterior or posterior approach is used.

A single-centre retrospective comparative design was used to assess 90-day mortality and morbidity rates in consecutive patients who underwent 1B-THA between 2004 and 2018. The groups managed with the anterior approach (AA) without traction table and posterior approach (PA) were compared. The ASA score was ≤2 and age ≤80 years in all patients. The groups were comparable for age, sex distribution, ASA score, pre-operative haemoglobin level, and reason for THA.

We included 55 patients managed via the AA and 82 managed via the PA. No patients died in either group. Early complications occurred in 3 patients in the AA group and 6 in the AP group (p=0.74). No differences were noted between the two groups for each type of complication. In the AA group, 3 patients experienced major complications (p=0.06) (2 cerebrovascular events and 1 peri-prosthetic fracture). In the PA group, 6 patients experienced minor complications (1 case each of dislocation, piriformis syndrome, sacral pressure sore, and deep vein thrombosis and 2 cases of ilio-psoas irritation; p=0.08). Operative time was 144minutes (range, 110-195minutes) in the AA group and 171minutes (range, 108–255minutes) in the PA group (p<0.001). Mean hospital stay length was 7.6 days (range, 3-13 days) overall, 6.7 days (range, 5–11 days) in the AA group, and 8.2 days (range, 3–13 days) in the PA group (p<0.001). The early re-admission rate was 2.9% overall, with no difference between the AA group (3.6% [2/55]) and the PA group (2.4% [2/82]) A post-operative blood transfusion was required by 34/137 (24.8%) patients overall, 15/55(27.3%) patients in the AA group and 19/82 (23.2%) patients in the PA group (p=0.58).

In selected patients (ASA score 1 or 2 and age ≤80 years), 1B-THA was not followed by any early deaths in the patients managed using the anterior or posterior approach. Total early morbidity rates were low. Neither the types of complications nor the early re-admission rates differed between the AA and PA groups. The shorter operative time in the AA group is ascribable to change in patient installation between the two arthroplasties when the PA is used.

III, comparative study of consecutive patients.