Dynamics of hip joint effusion after posterior soft tissue repair in total hip arthroplasty

Dislocation after total hip replacement is more common in the early, postoperative period. Postoperative intraarticular haematoma and remaining seroma fluid and/or weakened posterior soft tissue wall may be contributing factors. Our purpose was to compare and follow with sonography the resorption of the postoperative volume of intraarticular fluid/synovial oedema after total hip arthroplasty (THA) with or without posterior soft tissue repair. Thirty-three consecutive patients with hip osteoarthritis were admitted for THA. All of them received the same type of cemented implant. Patients were randomised for posterior soft tissue repair or not. Sonography, measuring the anterior capsular distension, indicating the volume of intraarticular fluid/synovial oedema in the prosthetic hip joints, was performed after six and 12 months in all patients. At six months postoperatively greater capsular distension, i.e., remaining volume of intraarticular fluid/synovial oedema, was observed in the group with posterior soft tissue repair than in the group without. After one year the capsular distension had decreased in both groups and there was no significant difference between the groups. Our results show that posterior soft tissue repair after THA is associated with increased capsular distension during the first six months. After 12 months the volume of intraarticular fluid/synovial oedema is the same with or without posterior soft tissue repair.