Clinical orthopaedics and related research
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Clin. Orthop. Relat. Res. · Feb 2010
Comparative StudyDoes femoral component loosening predispose to femoral fracture?: an in vitro comparison of cemented hips.
The incidence of femur fracture around total hip arthroplasties continues to increase at substantial cost to society. These fractures are frequently associated with a loose femoral component. Consequently, we sought to test whether femoral component loosening predisposes to periprosthetic femoral fracture. ⋯ For the cadaveric specimens, torque to failure was reduced by 58%, whereas stiffness decreased 70% for the loose group compared with the well-fixed group. Fracture patterns were similar between synthetic and cadaveric femora with a proximal spiral pattern in loose specimens and more distal fracture patterns with well-fixed stems. Based on our data, patients with loosened femoral components are at risk for fracture at a substantially lower torque than those with well-fixed components.
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Clin. Orthop. Relat. Res. · Feb 2010
Reintervention after mobile-bearing Oxford unicompartmental knee arthroplasty.
Medial compartment osteoarthritis is a common disorder that often is treated by unicompartmental knee arthroplasty (UKA). Although the Oxford 3 prosthesis is commonly used based on revision rate and cumulative survival, our experience suggests that although there may be adequate implant survival rates, we observed a worrisome and undisclosed reintervention rate of nonrevision procedures. ⋯ Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
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Clin. Orthop. Relat. Res. · Feb 2010
Hip resurfacing data from national joint registries: what do they tell us? What do they not tell us?
Current-generation metal-on-metal hip resurfacing implants (SRAs) have been in widespread global use since the 1990s, and in the United States, specific implants have recently been approved for clinical use. Many recent publications describe short-term survivorship achieved by either implant-designing surgeons or high-volume centers. National joint replacement registries (NJRRs) on the other hand report survivorship achieved from the orthopaedic community at large. ⋯ Diagnoses other than primary osteoarthritis bear a higher risk of early revision of SRA as compared with THA. Revision of SRA does not lead to reproducible results with rerevision rates of 11% at 5 years. Given these predictors of failure, our review of data from the NJRR suggests stringent patient selection criteria might enhance the survival rates of SRA.
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Clin. Orthop. Relat. Res. · Feb 2010
Comparative StudyFear in arthroplasty surgery: the role of race.
Understanding the difference in perceived functional outcomes between whites and blacks and the influence of anxiety and pain on functional outcomes after joint arthroplasty may help surgeons develop ways to eliminate the racial and ethnic disparities in outcome. We determined the difference in functional outcomes between whites and blacks and assessed the influence of fear and anxiety in total joint arthroplasty outcomes in 331 patients undergoing primary hip and knee arthroplasty. WOMAC, Quality of Well Being, SF-36, and Pain and Anxiety Symptoms Scale (PASS) were administered pre- and postoperatively (average 5-year followup). For the SF-36 General Health Score, blacks reported having worse perceived general health than whites before surgery. Regardless of time, blacks scored worse than whites for all measures except for the SF-36 physical function and general health scores. Blacks had a greater fear score (ie, that associated with the procedure) and total PASS score. For both races, there was a low association between the fear dimensions and dependent measures before and after surgery. Black patients undergoing hip and knee arthroplasty had lower scores than whites in most outcome measures regardless of time of assessment. We found higher fear levels before joint arthroplasty in blacks compared with whites. After surgery, blacks had much higher associations of the fear subscale, cognitive subscale, and total PASS score with the WOMAC physical function, pain, and total scores. ⋯ Level II, prospective controlled cohort study. See Guidelines for Authors for a complete description of levels of evidence.