Introduction

Total hip arthroplaty (THA) using direct anterior minimal invasive (AMI) surgery is an attractive option to achieve a quicker habilitation. However, high complication rates were reported and very often related to technical difficulties at the time of surgery. We hypothesized that 3D preoperative planning may allow to anticipate these difficulties and to decrease the complications rates when using an AMI approach.

Introduction

According to the literature, the gait does not return to normal after THA. However, the three-dimensional hip anatomy is usually not assessed before and after surgery. Our hypothesis was that an accurate reconstruction of the hip anatomy, based on a three-dimensional preoperative planning, may normalize the gait after THA.

Purpose of the study: The major functional impairment which results from femoral head necrosis in patients with sickle-cell anemia leads to implantation of a total hip arthroplasty (THA) in many of these often young patients. Intra- and postoperative complications are frequent.

Material and methods: In order to better understand the causes of these complications, and to search for ways of preventing them, we analyzed the cases of 35 sickle-cell anemia patients with 38 THA. Mean patient age was 36.4 years for these 22 women and 13 men. Twenty-eight patients had SS hemoglobin, five AS hemoglobin, and two presented sickle-cell-thalassemia (S-ß-hemoglobin). Mean follow-up was 7.6 years (range 2–29 years).

Results: Fifteen patients underwent revision surgery (39%) on average 4.8 years after primary implantation for loosening (n=13) or infection (n=2). Five other prostheses presented peripheral lucent lines (13%). The overall complication rate was 64% (shaft fractures, sickle cell crisis, dislocation or loosening, infection). One patient developed an early superficial infection which resolved. One other patient required revision for severe pain and prosthesis misalignment (flexion-external rotation) but with normal cell counts and a simply inflammatory synovial fluid. The presence of slowly progressive degenerative disease in a patient with severe pain should be carefuly identified before undertaking THA. Systematic samples are necessary. The femor-related complications in this series were: two intraoperative shaft fractures, one fracture below the stem during the first six months, and intraoperative shaft reaming in two. Femoral shaft morphological anomales must be identified preoperatively to enable a proper surgical plan. Small-size femoral stems should be available and zones of sclerosis in the canal must be identified. Cup-related complications are more difficult to analyze. The bony structure of the acetabulum was often remodeled, with very weak cancellous bone. Avivement of the acetabulum must be performed prudently manually or with a well controlled motor.

Discussion: Series report few cases in the literature, on average 22 cases (8–36). Mean follow-up was 5.1 years (range 4.6–9.5). The overall rate of complications was 42% (33–59) except for one series with only 2.8%. The rate of deep infection was 14.8% on average (0–36.4).

Conclusion: The decision to implant a THA in these young patients must be made conjointly with the patient. Multidisciplinary management before surgery is essential. Precise planning must take into consideration all the potential pitfalls. Special attention must be given to hemodynamic balance, intra- and postoperative oxygenation and the hemoglobin level.