Types Of Total Hip Replacements Research Articles

A prospective study on cancer risk after total hip replacements for 41,402 patients linked to the Cancer registry of Norway

BackgroundConcerns have been raised that implants used in total hip replacements (THR) could lead to increased cancer risk. Several different materials, metals and fixation techniques are used in joint prostheses and different types of articulation can cause an increased invasion of particles or ions into the human body.MethodsPatients with THR registered in the Norwegian Arthroplasty Register during 1987–2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular components). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender and if the patient had additional THR-surgery in the same or the opposite hip. The study follows the STROBE guidelines.ResultsComparing patients with THR to the general population in Norway we found no differences in cancer risk. The overall SIR for the THR-patients after 10 years follow-up was 1.02 (95% CI: 0.97–1.07). For cemented THR, the SIR after 10 years follow-up was 0.99 (95% CI: 0.94–1.05), for uncemented, 1.16 (95% CI: 1.02–1.30), and for hybrid 1.12 (95% CI: 0.91–1.33). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk for cancer (hazard ratio: HR = 1.24, 95% CI: 1.05–1.46, p = 0.009) when compared to patients with cemented THRs after 10 years follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR = 1.07, 95% CI: 0.85–1.35, p = 0.55) compared to patients with cemented THRs.ConclusionsTHR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk for cancer compared to cemented THR in males, but that this may be prone to unmeasured confounding.

Imaging post total hip replacement – how to interpret, what to expect and what to look out for!

Purpose: To categorise the different types of total hip replacement, how to interpret the postoperative radiograph and a pictorial review of the possible associated complications.

Adventure sports and sexual freedom hip replacement: the tripolar hip.

Certain athletic activities and lifestyles require a completely stable and very mobile hip. Total hip replacement with a natural femoral head size and two mobile-bearing surfaces (i.e., a "tripolar" prosthesis) is the most stable prosthesis. Elegant design and wear-resistant bearing surfaces are the keys to long-term implant survivorship. The hypothesis is that a ceramic-coated tripolar prosthesis using highly cross-linked polyethylene can provide full function and complete stability with low wear. This study sought to determine: (1) patient-reported outcomes, (2) functional outcomes, (3) implant survivorship and complications, and (4) postoperative sexual limitations. Between 1998 and 2011, the author performed 160 primary total hip replacements using tripolar prostheses in patients participating in adventure sports and other physically demanding activities. The institutional review board approved this study. The inclusion criteria were patients who needed unrestricted activity and who were not candidates for or did not choose hip resurfacing. Patients were followed every second year and assessed with radiographs, Harris Hip Score, WOMAC, SF-12, and UCLA functional outcome scores. Patients were asked about symptoms of instability and satisfaction with their hip replacement. Patients were asked both preoperatively and 2years postoperatively four questions about their sexual activity. Mean follow-up was 11years. At 2years' postoperatively, 98% of patients reported their satisfaction as excellent or good and 99% were not limited for sexual activity following surgery. Seventy-four percent of patients reported they were recovered within 6weeks of surgery. There were no dislocations. There were three revision procedures for implant loosening, infection, and periprosthetic fracture, but there were no failures of the tripolar articulation. The mean postoperative UCLA score was the highly athletic score of 8. There were no signs of osteolysis, wear, or metal sensitivity reactions. The range of motion achieved, sexual, and functional outcomes were higher than with other types of total hip replacement. This ceramic-coated tripolar prosthesis using highly cross-linked polyethylene provides full function, complete stability, and low wear to younger, active patients, thus confirming the hypothesis and clinical relevance.

Indications for dual-mobility hip replacements

This project was aiming to look at the indications for dual-mobility hip replacements. Dual-mobility hip replacements are a type of total hip replacement which aim to increase stability compared to standard total hip replacement due to the large head size, increased range of motion, and, at least theoretically, reduce wear due to lower frictional torque. Lancashire Teaching Hospitals Trust began using dual-mobility hip replacements in 2013, and this retrospective analysis looks at each of the 174 patients who received one since then to discover why they were put in and how this relates to the NICE guidelines for treating certain types of hip problems. The results have shown that 102 were primary hip replacements for displaced intracapsular fracture of the femur, 31 were revisions for instability and 41 were for other indications, both primary and revision. Of the 174 dualmobility cups put in, 3 have dislocated, but all were reduced successfully and have remained stable since. This gives the dual-mobility cups a current revision rate of 0%, which is very successful in comparison to the average revision rate for a standard (non-dual-mobility) total hip replacement.

Setting benchmark revision rates for total hip replacement: analysis of registry evidence

Objective To compare 10 year revision rates for frequently used types of primary total hip replacement to inform setting of a new benchmark rate in England and Wales that will...

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation.

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation.

Total hip replacement for the treatment of end stage arthritis of the hip: a systematic review and meta-analysis.

BackgroundEvolvements in the design, fixation methods, size, and bearing surface of implants for total hip replacement (THR) have led to a variety of options for healthcare professionals to consider. The need to determine the most optimal combinations of THR implant is warranted. This systematic review evaluated the clinical effectiveness of different types of THR used for the treatment of end stage arthritis of the hip.MethodsA comprehensive literature search was undertaken in major health databases. Randomised controlled trials (RCTs) and systematic reviews published from 2008 onwards comparing different types of primary THR in patients with end stage arthritis of the hip were included.ResultsFourteen RCTs and five systematic reviews were included. Patients experienced significant post-THR improvements in Harris Hip scores, but this did not differ between impact types. There was a reduced risk of implant dislocation after receiving a larger femoral head size (36 mm vs. 28 mm; RR = 0.17, 95% CI: 0.04, 0.78) or cemented cup (vs. cementless cup; pooled odds ratio: 0.34, 95% CI: 0.13, 0.89). Recipients of cross-linked vs. conventional polyethylene cup liners experienced reduced femoral head penetration and revision. There was no impact of femoral stem fixation and cup shell design on implant survival rates. Evidence on mortality and complications (aseptic loosening, femoral fracture) was inconclusive.ConclusionsThe majority of evidence was inconclusive due to poor reporting, missing data, or uncertainty in treatment estimates. The findings warrant cautious interpretation given the risk of bias (blinding, attrition), methodological limitations (small sample size, low event counts, short follow-up), and poor reporting. Long-term pragmatic RCTs are needed to allow for more definitive conclusions. Authors are encouraged to specify the minimal clinically important difference and power calculation for their primary outcome(s) as well CONSORT, PRISMA and STROBE guidelines to ensure better reporting and more reliable production and assessment of evidence.

Bilateral gait patterns in subjects fitted with a total hip prosthesis

Objectives: The purpose of this report was to determine whether the muscle powers and the mechanical energies developed during the push-off period of the gait cycle of patients having a total hip prosthesis were different from able-bodied subjects as well as the effect on the nonoperated limb. Design: Case control study. Setting: All patients where independent and functional. Patients: Four patients participated in the study. The indication for surgery was degenerative arthritis of the hip. There was also an able-bodied group. Intervention: A HarrisGalante total hip prosthesis was used to restore hip stability and function. The patients were all operated on by the same orthopedic surgeon and had the same type of total hip replacement. Main outcome measure: Gait analyses showed that not only the hips of the surgical group were affected but also the knees. Results: Peak power did not show any significant difference except for a decrease in the frontal plane of the operated hip power absorption. The operated hip developed 35% and 48% less energy than that of the able-bodied group in the sagittal and frontal planes, respectively. The nonoperated hip was also affected and developed 35% more energy in the sagittal plane than the operated limb but 20% less than that of the able-bodied group. There was a reduction of 47% in the energies developed in the knees of the surgical patient group. Conclusion: These results confirmed the presence of some mechanical dysfunction in the nonoperated limb.

Three dimensional shape reconstruction and finite element analysis of femur before and after the cementless type of total hip replacement

Computerized tomography was used to reconstruct a shape, and stresses in three-dimensional objects were analysed. The human femur, which has a very irregular shape, was chosen as an object. CT image data of a cadaver femur were transferred to a computer, and an edge extraction program generated the cross-section of bone by specifying a range of CT values for each slice. Pixel data from the CT scan are converted into a vector of points (x, y, z) which can specify the boundaries of bone. Lateral surfaces are defined by stacking up the slices and making use of the vectorized data. Intermediate and oblique cross-sections can be obtained by an interpolation technique. The constructed model was used as input data for the finite element analysis. To understand the stress distributions before and after the cementless type of total hip replacement, a three-dimensional finite element stress analysis of the bone-implant system was carried out, assuming micromotions between the stem and the femur. The analysis was done for both frictionless and friction cases, modelling the contact point with a gap element having isotropic friction. The analysis shows that the stress is not concentrated on the femoral calcar when the friction coefficient is large.