The John Charnley Award: Risk Factors for Cup Malpositioning: Quality Improvement Through a Joint Registry at a Tertiary Hospital
Few studies have examined factors that affect acetabular cup positioning. Since cup positioning has been linked to dislocation and increased bearing surface wear, these factors affecting cup position are important considerations.
The Otto Aufranc Award: Enhanced Biocompatibility of Stainless Steel Implants by Titanium Coating and Microarc Oxidation
Stainless steel is one of the most widely used biomaterials for internal fixation devices, but is not used in cementless arthroplasty implants because a stable oxide layer essential for biocompatibility cannot be formed on the surface. We applied a Ti electron beam coating, to form oxide layer on the stainless steel surface. To form a thicker oxide layer, we used a microarc oxidation process on the surface of Ti coated stainless steel. Modification of the surface using Ti electron beam coating and microarc oxidation could improve the ability of stainless steel implants to osseointegrate.
The Frank Stinchfield Award: The Impact of Socioeconomic Factors on Outcome After THA: A Prospective, Randomized Study
Most studies of total hip arthroplasty (THA) focus on the effect of the type of implant on the clinical result. Relatively little data are available on the impact of the patient’s preoperative status and socioeconomic factors on the clinical results following THA.
Total hip arthroplasty (THA) provides high functional scores and long-term survivorship. However, differences in function and disability between men and women before and after arthroplasty are not well understood.
The introduction of new technology has increased the hospital cost of THA. Considering the impending epidemic of hip osteoarthritis in the United States, the projections of THA prevalence, and national cost-containment initiatives, we are concerned about the decreasing economic feasibility of hospitals providing THA.
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.
The Incidence of Acetabular Osteolysis in Young Patients With Conventional versus Highly Crosslinked Polyethylene
Osteolysis is a major mode of hip implant failure. Previous literature has focused on the amount of polyethylene wear comparing highly crosslinked polyethylene (HXPLE) with conventional liners but has not clarified the relative incidence of osteolysis with these two liners.
Aseptic osteolysis has been the single most important factor limiting the longevity of a THA. A great deal of attention has been focused on the development of implants and materials that minimize the development of osteolysis. The monoblock porous tantalum acetabular cup was designed to minimize osteolysis, but whether it does so is unclear.
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.
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.
Polyethylene wear may be affected by the type of polyethylene resin, manufacturing technique, degree of thermal stabilization, and sterilization technique.
Acetabular Component Positioning Using the Transverse Acetabular Ligament: Can You Find It and Does It Help?
Several studies have reported that the transverse acetabular ligament (TAL) can be used to orient the acetabular component during total hip arthroplasty and that it can be identified in nearly all patients.
In 2005, we reported removal of functional restriction after primary THA performed through the anterolateral approach did not increase the incidence of dislocation.
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.
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.
Alternative bearing materials in THA have been developed to reduce the incidence of osteolysis. Alumina-on-alumina bearings exhibit extremely low wear rates in vitro, but concerns exist regarding component impingement with the potential for dislocation and the occurrence of noise.
Restoration of hip offset and leg length during THA is often limited by available implant geometries. The recent introduction of femoral components with a modular junction at the base of the neck (two modular junction components) has expanded the options to restore femoral offset and leg length.
Bernese Periacetabular Osteotomy in Males: Is There an Increased Risk of Femoroacetabular Impingement (FAI) After Bernese Periacetabular Osteotomy?
The Bernese periacetabular osteotomy (PAO) is a popular option for treating symptomatic acetabular dysplasia. We noted symptomatic impingement after PAO in several male patients.
Impingement events, in addition to their role immediately proximate to frank dislocation, hold the potential to damage new-generation hard-on-hard bearings as a result of the relatively unforgiving nature of the materials and designs. Because of the higher stiffness and tighter design tolerances of metal-on-metal and ceramic implants, surgical positioning plausibly has become even more important.
Validity of the Alpha Angle Measurement on Plain Radiographs in the Evaluation of Cam-type Femoroacetabular Impingement
Cam-type femoroacetabular impingement is secondary to lack of concavity at the anterosuperior femoral head-neck junction, resulting in reduced femoral head-neck offset and femoral head asphericity. This morphologic deformity can be detected by MRI and plain radiographs and quantified using the alpha angle.
Proximal femoral replacement using a segmental modular system is one option for revision THA in the presence of severe bone loss or periprosthetic fracture. While many papers report function in these patients, they do not describe the quality of life.
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.
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.
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.
Recent attention in THA has focused on minimally invasive techniques and their short-term outcomes. Despite much debate over the outcomes and complications of the two-incision and the mini-lateral and mini-posterior approaches, complications arising from use of the anterior THA on a fracture table are not well documented.
A femoral implant with a modular sleeve and stem has been designed to allow independent and complete metaphyseal-diaphyseal fit and fill as well as independent rotation to accommodate anteversion at the time of THA.
Local elution of zoledronic acid from a porous implant reportedly enhances periimplant bone formation and implant fixation. However, there is no information in the literature on the extent to which eluted bisphosphonate remains localized around the implant or becomes systemically distributed.
Perivascular lymphocytic infiltration (PVLI) suggests an adaptive immune response. Metal hypersensitivity after THA is presumed associated with idiopathic pain and aseptic loosening, but its incidence and relationship to metallic wear leading to revision are unclear as are its presence and relevance in non-metal-on-metal arthroplasty.
Incidence of Postthrombotic Syndrome in Patients Undergoing Primary Total Hip Arthroplasty for Osteoarthritis
Postthrombotic syndrome (PTS) is a chronic condition in the lower extremity that develops after deep vein thrombosis (DVT). The incidence of PTS after total hip arthroplasty (THA) is not well established.
Markers of Thrombin Generation During Resurfacing and Noncemented Total Hip Arthroplasty: A Pilot Study
Hip resurfacing arthroplasty (HRA) could be associated with an increased risk of deep vein thrombosis (DVT) compared to traditional noncemented THA because it involves greater dissection, increased kinking and distortion of the femoral vessels, takes longer to perform, and involves insertion of some cement into the femur.
Revision THA is associated with high blood loss and a high probability of blood transfusion in the perioperative period. In November 2003, government legislation established the Blood Utilization Program at our center to reduce the rate and risks associated with allogenic transfusion.
Infection is uncommon after THA performed for failed acetabular fracture repair, despite a high reported incidence of culture-positive fixation implants. The use of frozen section analysis at the time of THA after acetabular fracture fixation surgery is unknown.
Multilevel Measurement of Acetabular Version Using 3-D CT-generated Models: Implications for Hip Preservation Surgery
Numerous structural deformities of the acetabulum are associated with hip osteoarthritis (OA). Acetabular retroversion has been implicated in the development of femoroacetabular impingement. However, it is unknown if retroversion occurs from isolated excessive bone in the superior acetabulum or a torsional phenomenon of the entire pelvic segment.
Loosening of acetabular components often leads to bony defects. Management of extensive acetabular bone loss in hip revision arthroplasty can be a tremendous challenge.
What is the Evidence for Total Knee Arthroplasty in Young Patients?: A Systematic Review of the Literature
TKA is commonly performed to treat advanced inflammatory and degenerative knee arthritis. With increasing use in younger patients, it is important to define the best practices to enhance clinical performance and implant longevity.
Patients with malignant fibrous histiocytoma of bone (MFH-B) and osteosarcoma reportedly have comparable survival rates, despite the lesser chemosensitivity of patients with MFH-B compared with those with osteosarcoma.
Many surgeons treat giant cell tumor of bone (GCT) with intralesional curettage. Wide resection is reserved for extensive bone destruction where joint preservation is impossible or when expendable sites (eg, fibular head) are affected. Adjuvants such as polymethylmethacrylate and phenol have been recommended to reduce the risk of local recurrence after intralesional surgery. However, the best treatment of these tumors and risk factors for recurrence remain controversial.
Major disadvantages of antibiotic bone cements include limited drug release and reduced strength resulting from the addition of high doses of antibiotics. Bacterial cellulose, a three-dimensional hydrophilic mesh, may retain antibiotics and release them gradually. We hypothesized that the addition of cellulose to antibiotic bone cement would improve mechanical strength and antibiotic release.
Vascular reconstruction in infants constitutes a surgical challenge and is indicated frequently for acute occlusions. With the presence of a subacute vascular occlusion, including that produced by tumor resection, collateral circulation develops quickly. Thus a surgeon can consider tumor and vessel resection, without the need for vascular reconstruction.
Locking titanium plates revolutionized the treatment of osteoporotic and metaphyseal fractures of long bones. However as with any innovation, with time new complications are identified. One of the problems with titanium locking plates is removal of screws, often attributable to cold welding of screw heads into the locking screw holes. Several techniques have been described to overcome this problem. We describe a new easy technique to remove a jammed locking screw in a locking plate that is easily reproducible and suggest an algorithm to determine the method to remove screws from locking plates.