Hip 723 articles
Legg-Calvé-Perthes disease (LCPD) was described a century ago. In previous long-term reports of patients with LCPD, nonoperative treatment varied considerably. The likelihood of hip osteoarthritis (OA) developing in patients with LCPD and possible need for THA are not well defined.
Optimal techniques for acetabular revision in the setting of major pelvic osteolysis have not been established. Bilobed components, structural grafts, and reinforcement cages have demonstrated 10–24% midterm failure rates. While cementless hemispherical components have been utilized to treat large acetabular defects, most reports have not focused specifically on patients with extensive deficiencies.
Modular femoral stems are one option for revision THA surgeons and allow offset restoration, leg length discrepancy correction, and stability independent of distal stem fixation. The complexity of revision THA usually leads surgeons to use multiple revision hip designs to address these issues.
Hip arthroscopy is an evolving procedure. One small study suggested that a low modified Harris hip score and arthritis at the time of surgery were predictors of poor prognosis.
Highly cross-linked polyethylene (HXLPE), created by disrupting the molecular structure of polyethylene, then through the application of heat, encourages creation of new cross-links in the process, resulting in a material with improved wear resistance. The impetuses for this new technology were the unsatisfactory wear properties and subsequent osteolysis of noncross-linked polyethylene. A 72% reduction in wear using highly cross-linked polyethylenes (HXLPE) compared with conventional polyethylene at 5 years was described previously. The longest term followup studies on HXLPE range from 2 to 6 years.
The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking.
Offset in THA correlates to abductor muscle function, wear, and impingement. Femoral offset after THA is not independent of the cup center of rotation (COR) so hip offset, a combination of femoral offset and change in hip COR, becomes the important measurement.
Although surgical navigation reduces the rate of malpositioned acetabular cups in total hip arthroplasty (THA), its use has not been widely adopted. As a result of our perceived need for simple and efficient methods of navigation, we developed a mechanical navigation device for acetabular cup orientation.
Retrieved Highly Crosslinked UHMWPE Acetabular Liners Have Similar Wear Damage as Conventional UHMWPE
Highly crosslinked UHMWPE is associated with increased wear resistance in hip simulator and clinical studies. Laboratory and case studies, however, have described rim fracture in crosslinked acetabular liners. Controversy exists, therefore, on the relative merits of crosslinked liners over conventional liners in terms of wear performance versus resistance to fatigue cracking.
Evidence suggests a growing incidence of revision total hip arthroplasty (THA) including a subset with large acetabular defects. Revision THA for severe acetabular bone loss is associated with a relatively high rate of mechanical failure.