Acetabular Screw cup implant as a rescue procedure in case of failure to obtain sphericity allowing stable settlement of press-fit acetabular cup

Abstract

Background. The lack of ideal sphericity of the hip joint acetabular bed is a problem encountered by orthopedists during the initial process of learning about hip joint replacement procedures. The aim of the study was analysis of the complications after cementless endoprosthesoplasty, when the primary sphericity was not obtained and the “Screw Cup” acetabulum (Aesculap) was used as a rescue procedure. Material and methods. The inclusion criteria were met only by 39 patients since, due to numerous complications, such implants were no longer used for patients aged 44–90 years and the average time of postoperative observation was 54 months. The patients were operated in a lateral position, from the posterolateral access or minimally invasive posterior access. In order to assess hip joint function after the procedure, the Harris and Hoos Hip Score questionnaires were used. Results. Harris Hip Score revealed 64.3%very good and good results and the obtained mean score was 96 points according to Hoos’s questionnaire. The type of surgical incision, BMI values and the types of dermal sutures had no impact on the functional result, the rate of complications and the incidence of pain in the groin. All the pa­tients who underwent surgical procedures using the minimally invasive access and whose skin sewn using a transdermal continuous suture, assessed their postoperative scars as esthetic. However, the lateral position during the procedure significantly complicated the intraoperative limb length assessment. In consequence, 30% of the opera­ted patients reported different lengths of their lower limbs, which significantly (p = 0,036) reduced the score corresponding to limb functionality, measured using HOOS and Harris Hip Score. The functional values show a significantly negative correlation with age, but not with gender, although men are more at risk of postoperative complications (p = 0,18). Despite the relatively big number of postoperative complications after surgical procedures using the “Screw Cap” acetabular implants, 75% of patients operated using this approach reported no objections to secondary procedures using the same system. Conclusions. Using the Screw Cap” acetabular implants in cases of failure to obtain an ideal sphericity entails the risk of numerous complications and only 60% of the results are good and very good, therefore, the authors of this paper do not recommend this solution.