A Prospective Randomized Comparative Study Between Midvastus and Standard Medial Parapatellar Approaches for Total Knee Replacement Regarding the Peri-Operative Factors

Abstract

Introduction The aim of this study was to determine whether the midvastus (MV) approach in patients who underwent total knee replacement (TKR) results in differences regarding peri-operative parameters, such as surgical time, blood loss, transfusion need and complications, when compared with medial parapatellar approach (MP). Methods This was a prospective randomized comparative study of patients who received primary TKR. The first group consisted of patients where the MP approach was used and the second those where the MV approach was utilized. Patient's age, body mass index (BMI), stage of osteoarthritis (OA), prosthesis design, duration of surgery, blood loss in the drainage, hemoglobin (Hb), and intra-operative complications were recorded. Results From December 2019 to June 2020 a total of 107 (22 males, 85 females) and 38 (seven males, 31 females) patients were operated on with the MP and MV approaches, respectively. The two groups did not differ in terms of age, BMI, gender and stage of OA, however, pre-operative haemoglobin (Hb) was higher in the MP group [mean 13,5 (1.3) versus 13.1 (0.73)]. There was no significant difference in Hb decline pre- and post-operatively and in drain volume between groups. The mean Hb drop was similar for the MP [-2.2 (1.08)] and MV [-2.52 (1.06)] groups, and even though the transfusion rates were lower for the MP group, it did not reach significance. The duration of surgery was significantly longer in the MV group, with a mean time of 95.6 (12.94) minutes versus 89.4 (14.28) in the MP group. Overall complications did not differ significantly among the two surgical approaches. Multivariate logistic regression demonstrated that pre-operative Hb [OR 2.6 95% CI (1.43, 4.75)] and approach [OR 4.15 95% CI (1.15, 14.98)] were significantly correlated with the need for transfusion when gender, BMI, redon drainage, prosthesis size and duration of surgery were considered together. Conclusion In our experience, total knee replacement performed with either the midvastus or medial parapatellar approach does not result in any advantage with regards to the intra-operative complications, drain blood volume or difference in Hb drop post-operative. However, the midvastus approach presents a longer operation time, with the risk of higher transfusion rates for the patients.

Keywords: blood loss; complications; medial parapatellar; midvastus; total knee replacement.

Figure 1. Post-operative changes in hemoglobin (Hb) among the two surgical approaches.