Clinical outcomes of hip arthroscopic treatment for femoroacetabular impingement:a comparative study between Inside-out and Outside-in approach

Abstract

To compare the clinical outcomes and complications of hip arthroscopic treatment for femoroacetabular impingement (FAI) performed with either Inside-out or Outside-in approach. The clinical date of 48 patients with FAI treated by hip arthroscopy surgery and follow-up from June 2016 to June 2019 were retrospectively analyzed. According to the different operative methods, the patients were divided into two groups. Inside-out group, from central compartment to peripheral compartment;Outside-in group, from peripheral compartment to central compartment. There were 14 males and 10 females in Inside-out group with an averageage of (39.8±7.6)years old, 13 males and 11 females in Inside-out group with an average age of (39.5±9.1)years old in Outside-in group. There was no significant difference in age, gender, body mass index, side, impingement type, medical history and follow-up time between the two groups. The complication occurrence rate, modified Harris hip score (mHHS)and nonarthritic hip score (NAHS) were compared between these two groups. The mHHs and NAHS scores of the two groups were significantly higher than those before operation, but there was no significant difference between the two groups (P>0.05). In the Inside-out group, there were 4 cases of nerve traction injury and 3 cases of iatrogenic injury, while only 1 case of nerve traction injury occurred in the Outside-in group. The incidence of complications in the inside out group was higher than that in the outside in group (16.7% vs 4.2%, χ2=5.400, P=0.020). Both hip arthroscopic surgery methods can obtain satisfactory clinical efficacy in the treatment of FAI, but the incidence of postoperative complications of Outside-in surgical method is lower. The out-side in method can be preferentially selected for the patients with the indications of operation.