On this stem, an artificial ball is attached using an engineering taper. The ball is made of either cobalt-chrome metal, or ceramic. The ball can be changed at any time in the future, if need be, without removing the stem from the femur. What brand of hip implants do you use? These designs have withstood the test of time, with excellent long-term results.
Implant companies make several models and designs of implants, and the precise application depends on individual patient needs and anatomy. The most common bearing surface we use in hip replacements is a cobalt-chrome ball with a cross-linked polyethylene socket liner.
This bearing is built upon decades of experience with standard non cross-linked polyethylene; the material offers more flexibility and options to make hip replacement safe and predictable.
If you have a strong preference for a certain type of joint prosthesis, or a certain type of material, we can discuss using that implant and material. There is very little difference between the implants offered by the major manufacturers. No implant company pays us to promote or use any product.
What if I want a particular brand of hip replacement? Simply let us know. Because of our emphasis on research and investigation, we embrace the latest technology, biomaterials and surgical methods. However, be cautious about the unregulated marketing and promotion of hip and knee implants.
Orthopaedic companies and hospitals want business, and their advertisements rarely give the complete picture. We can offer unbiased opinion about different implants, while respecting whatever decision you make in this regard. How much do the parts used in hip replacement weigh? The parts weigh about three to five pounds. The bone your surgeon removes during hip replacement weighs a little less. So, you may gain a few pounds of body weight because of hip replacement surgery.
This is more than balanced by the fact that people tend to lose weight after surgery due to diminished appetite and the stress of an operation. Why does an artificial hip wear? Everything wears out over time, and artificial hip bearings are no exception.
During everyday activity, our hips endure several million cycles a year. People who are athletic or walk more than usual will load their joints even more. Cyclic loading leads to wear, even though modern hip bearings are extremely wear-resistant.
However, no bearing surface is completely wear-proof. Realistically, for most patients, bearing wear in an artificial hip is not a practical concern. Where do wear particles from the artificial hip go? All hip bearings produce microscopic wear particles that collect in the soft tissue envelope around the artificial hip. This layer of tissue — called the hip capsule — forms around the prosthetic joint after surgery.
Some wear particles migrate into the body, and are spread by the circulating blood to remote organs such as the heart, liver, spleen and lymph nodes. No study has shown any adverse impact of such wear particles from artificial hips that spread throughout the body, although this remains an area of investigation and research. What is the advantage of ceramic bearings in hip replacement?
Ceramics are synthetic materials, used in industrial applications. When used in orthopaedic bearings, their wear rates are extremely low. This is an area of research interest for us; we completed an FDA-approved trial of ceramic hips some years ago. Those bearings are now available for use by community surgeons in the United States. We performed a prospective analysis of the outcome of conversion surgery in patients with failed hemiarthroplasty.
The patients had clinical evaluations at 1 month, 6 months, 1 year, and annually thereafter. We used Harris Hip Score HHS to evaluate the results of conversion procedure in terms of relief of groin pain and functional improvement. Dislocation occurred in 6 patients 4. The mean period of follow-up was 42 months range 36—60 months. HHS score improved from mean preoperative score of The survivorship analysis with revision of HHS score was THA is a safe option which can lead to good functional and short-term and mid-term outcomes; and patients should be informed of the possibility of incomplete relief of groin pain or other symptoms postoperatively.
Keywords: conversion, failure, hemiarthroplasty, total hip arthroplasty 1. Cementing technique Since new cementing techniques have been introduced, the long-term results of the cemented prosthesis have been considerably improved.
A cement restrictor, placed a centimeter or so below the prosthesis, allows the cement to be pressurized so that it flows into the cancellous bone rather than into the distal femur. Before inserting cement, clean the canal with irrigation and an appropriate brush.
Place a temporary dry sponge in the canal, to be removed just before the cement is inserted. By mixing the cement liquid and powder in a low-pressure container, air bubbles are avoided, and the cement is stronger.
Cementing of the medullary canal The prepared medullary cavity is filled from bottom to top with a cement gun, as illustrated. Withdraw the cement gun as the medullary canal fills.
Avoid mixing blood or air with the cement. Compressing the cement before and by prosthesis insertion pushes it into the surrounding bone, thus improving its anchorage.
Prosthesis insertion Before the cement hardens, the prosthesis is inserted with correct rotation anteversion and valgus alignment. It must be placed to the appropriate, predetermined depth. Once the stem is seated, allow the cement to set undisturbed. Trim off any excessive cement, and carefully remove all cement fragments from the hip joint and surrounding wound.
Assembly of the prosthesis For a hemiarthroplasty, use a trial femoral head prosthesis on the cemented stem to confirm both diameter and neck length. The latter affects both leg length soft-tissue tension, and hip stability.
For total hip arthroplasty a similar trial prosthesis is used to check length and offset. Head size, however, is determined by the preoperatively selected acetabular component. Total hip prostheses with larger heads tend to be more stable.
With the hip reduced, confirm range of motion and stability. Adjust the neck and head if necessary. Once satisfactory, attach the definitive femoral head to the stem, and reduce the hip. Confirm complete reduction, stability, and range of motion. While the external diameter of the acetabular component is definitively selected intraoperatively, its internal diameter, the same as that of the matching femoral head component, is a feature of the chosen prosthetic system.
The acetabular prosthesis must be fixed to the pelvis. Early weight bearing may be safer with cement. This is usually preferable in the elderly and will be illustrated. Reaming First, the acetabular cartilage has to be removed with a reamer.There may be exceptions where certain patients need to avoid bending, crossing legs, or twisting at the waist - this will be explained to you specifically by your surgeon. Once bone grows into the socket and femoral stem, the bond is permanent. Purpose of this study was to evaluate the outcomes of patients underwent hemiarthroplasty for proximal femoral fracture converted to THA. Inside this shell, a locking mechanism fastens the bearing, which can be polyethylene, metal or ceramic. The short-term outlook of total hip replacement is excellent. Cementing of the medullary canal The prepared medullary cavity hips is superior to girdlestone Hip by itself. R: Reimplantation of the artificial hip joint in girdlestone optimized for their weight to bind to living bone. Everything wears out over replacement, and artificial hip bearings are no prosthesis. However, no bearing surface is completely wear-proof.
Side effects of pain medicine and anesthesia include nausea, constipation, mood changes and sometimes a tired feeling. When used in orthopaedic bearings, their wear rates are extremely low. Results: After an average follow-up of 6.
AP unilateral hip radiographs performed at one week postoperatively were used as a baseline, and wear measurements were performed on the most recent radiographs.
At 1-month follow-up, radiographs were evaluated to determine the inclination and anteversion of the acetabular component based on the AP film. Implant companies make several models and designs of implants, and the precise application depends on individual patient needs and anatomy. The average preoperative Harris Hip Score was 38 range The neck of the femoral component should usually be co-axial with the femoral neck, as in the illustration. If a patient has a problem with these side effects, often the medication can be adjusted or a different medication tried in order to minimize these effects.
They are safer, and have excellent long-term outcomes, with almost zero wear. The average age of these patients was
Yes, for three to six months. Femoral periprosthetic osteolysis or radiolucencies was observed in four hips in the tantalum rod group, but was not found in the control group Fig. Bearing surfaces in the hip are made of plastic, metal or ceramic. Realistically, for most patients, bearing wear in an artificial hip is not a practical concern.
These types of pain control are generally provided until the day after surgery. The difference between two corrected values was calculated to determine the distance of the liner wear. All hip bearings produce microscopic wear particles that collect in the soft tissue envelope around the artificial hip. Do you use human tissue or parts for hip replacement? All noninfected patients checked for C-reactive protein CRP and estimated sedimentation rate ESR preoperatively which were negative for them.
Anchorage holes For better anchorage of the cement and cup, several holes with a diameter of about 6 mm are drilled in multiple locations as illustrated.
If you have older films, please bring them in for comparison. Bearing surfaces in the hip are made of plastic, metal or ceramic. Based on the diameter of the implants, a medical metal-cutting trephine was chosen and placed over the proximal end of the tantalum rod. In reality, participation in sports such as golf and other activities is just as possible with one brand of hip components as the other. The tantalum rod was removed through two methods.