Using Tantalum Augments for Major Acetabular Bone Defects in Revision Hip Surgery

Aim. The purpose of the study was to follow up the clinical and functional results of the patients with major acetabular bone defects in revision hip surgery.Materials and methods. The study was retrospective, over a period of six years (from January 2014 to January 2019), and included all the patients with hip replacement, with major acetabular bone defects, who needed Tantalum blocks substitution.11 patients were included in the study (8 men and 3 women). The average age was 71 years (between 64 and 78 years old). The average follow up period was 23 months (between 11 and 36 months). Paprosky radiological classification was used for the preoperatory evaluation of the bone defects. In 9 cases, the bone defect was of type 2B Paprosky and in 2 cases, of type 3A. Harris score was determined preoperatory and postoperatory for the appreciation of functional results.Results. 6 patients were underwent replacement for coxarthrosis secondary to dysplasia, 2 patients for coxarthrosis secondary to aseptic necrosis and 3 patients for primary coxarthrosis.The average time elapsed from the moment of primary arthroplasty to the need of revision surgery was on average of 13 years (between 7 and 16 years). The postoperatory radiological evaluation showed an improvement of the hip rotation center from an average postoperative vertical position of 3.1 cm (between 1.2 and 4.6 cm) at an average postoperatory position of 1.1 cm (between 0.5 and 2.3). The average result of Harris score postoperatively was 36 (between 39 and 96). During the follow up period, no early loosening, infection or prosthesis dislocation was registered. Conclusions. The Tantalum Augments used in major acetabular bone defects in revision surgery represent a good option, correcting the hip rotation center, thus considerably improving the functional score.

Advantages and disadvantages of 3D printing for pre-operative planning of revision hip surgery

Total hip arthroplasty (THA) is one of the most successful and cost-effective interventions in medicine nowadays, providing reliable pain relief and functional improvement to those with osteoarthritis or inflammatory arthritis of the hip (P Kinov, B Antonov,’Possibilities for surgical treatment of acetabular osteolysis subsequent to revision arthroplasty of hip joint‘, Orthop Trauma. 52, 2015). Revision hip arthroplasty or severe reconstructive procedures in cases with significant anatomical defects require skilled surgical staff and accurate preoperative planning, including bone insufficiency, deficiency, discontinuity (anatomical assessment) as well as augmentation, cage or other requirements. (implant planning). Some authors recommend preoperative 3D model planning for precise anatomical assessment and preoperative training. This method has some limitations but could be successfully used in addition to conventional surgery.

Early radiological and functional outcomes for a cementless press-fit design modular femoral stem revision system

Aim: To assess early radiological and functional outcomes of revision hip surgery with a cementless press-fit design femoral stem. Patients and methods: A retrospective review of 48 consecutive revision total hip replacements using the RECLAIM revision hip system, between October 2012 and August 2015. Radiographic assessment was undertaken with serial anteroposterior (AP) X-rays of the pelvis. Risk factors for subsidence were evaluated. Prospective clinical follow up was performed on 21 patients to assess functional outcomes. Results: Mean stem subsidence was 1.1 mm (95% confidence interval[CI]: 0.63–1.57). Median follow up of 12 months. An inverse relationship was observed between level of subsidence and femoral stem diameter r = −0.45, p = 0.001. Subsidence at the time of follow-up assessment was correlated with initial subsidence (correlation coefficient rho 0.69, p = 0.001). The mean Merle d’Aubigne score at the latest follow up was 14.2 (range 8–17). The mean OHS was 34.1 (range 15–48). Conclusion: Early radiological and functional outcomes for the RECLAIM revision system showed very low levels of subsidence and good functional outcomes. There was an association with smaller diameter femoral stems and greater levels of subsidence.

Proximal Femoral Bone Regeneration After an Uncemented Hydroxyapatite-coated Long-stem in Revision Hip Surgery

Background: Bone remodelling with lateral femoral cortex thinning is a major concern after extensively porous-coated long-stem in revision surgery. Extensive hydroxyapatite coated long-stems were introduced to improve osseointegration, but bone remodelling changes have not been quantified. Objective: The question of whether bone remodelling changes from extensive hydroxyapatite-coated long stems influence the durability of femoral revision, clinical outcome is assessed in follow-up radiographs. Methods: Uncemented straight monoblock hydroxyapatite-coated long-stems used in revision hip surgery for aseptic loosening were assessed in a consecutive series of 64 hips (60 patients). Mean follow-up was 8.6 years and the mean age at surgery was 70 years (27-91). The pre-operative bone defect was classified according to Paprosky. Cortical struts were not used in this series. Cortical index and femoral cortical width were measured at three different levels at different periods. Results: Four patients with pain under level 4 due to stem loosening needed an exchange surgery of their femoral component, but two patients rejected re-surgery. The cumulative probability of not having aseptic loosening was 91.2% (95% confidence interval 73.5-96.9) at 10 years according to Kaplan and Meier. Twenty-seven of 35 osteolytic lesions had disappeared or decreased at the last follow-up. The thickness of the lateral and medial cortex increased over the course of the study at different levels. Increases of femoral cortex thickness were greater in men and in cases with mild bone defects. Conclusion: Although clinical outcome of the hydroxyapatite-coated long stem in revision surgery is good but not outstanding, most osteolytic lesions heal and the femoral cortex thickness increases at different levels.