Successful Total Hip Replacement Research Articles

The natural history of a posteriorly dislocated total hip replacement

A retrospective review was conducted to delineate the natural history of the posteriorly dislocated total hip replacement. A total of 1,036 consecutive total hip replacements were performed between 1989 and 1992. Forty (3.9%) were known to have dislocated posteriorly. Twenty-four of these dislocations occurred after primary replacements, and 16 occurred after revision. Eighty-five percent of the dislocations occurred within 2 months and were reduced closed. No statistical differences were noted between these 2 groups with respect to height, weight, sex, age, and femoral and acetabular anteversion. Nonunion of the greater trochanter, modular femoral neck length, and operative approach appeared to affect hip stability. Twenty-three of the 40 dislocated hips (57.5%) redislocated. Sixteen of the 40 hips (40%) required reoperation for recurrent dislocation. Thirteen of the 16 revisions (81.3%) were successful. A dislocated total hip replacement that has been rendered stable does not preclude one from having a successful total hip replacement, and it does not appear to affect survivorship at intermediate follow-up.

Importance of a thin cement mantle. Autopsy studies of eight hips.

The question whether thin cement mantles around cemented femoral components led to an increased frequency of cracks in the cement was asked. Microscopically, multiple cross sections of eight femurs retrieved at autopsy from clinically successful total hip replacements after prolonged in vivo service containing well fixed Harris Design 2 cemented femoral components were studied. None of the components were loose by radiographic criteria. All were fixed solidly when loaded in vitro in simulated stair climbing and gait, as assessed by high resolution micromotion sensors. The specimens were sectioned transversely at 5-mm increments. The cross sections were examined under a dissecting microscope at x 100. A thin mantle arbitrarily was defined as a mantle of less than 1 mm in thickness. The analysis of the contact radiographs showed that the routine anteroposterior and lateral radiographs underestimated the prevalence of thin cement mantles and mantle defects. Although overall on all the cross sections 9% of the aggregated cement mantles was classified as having thin cement, 92 of the 101 cement cracks occurred in areas of the mantles that were less than 1 mm thick.

Migration and wear of long-term successful Charnley total hip replacements

We analysed in-vivo migration and wear over a long period of all-polyethylene acetabular cups which had not been affected by mechanical loosening. The selection criteria of regular radiological follow-up, good clinical outcome (Charnley score of 5 or 6), continued walking without crutches and no radiological signs of loosening of the acetabular cups were fulfilled by 25 Charnley total hip arthroplasties. Mean migration, measured by the Nunn method, was 0.6 mm in the medial and 0.2 mm in the cranial direction. The mean yearly rate of wear was 0.05 mm and 0.04 mm, with six and two cups having no detectable wear, as measured by the Livermore and Charnley-Cupic methods, respectively. The maximal detected wear was 3.7 mm. There were no changes in the rate of wear with time. Computerised Ein Bild Röntgen Analyse (single-image radiological analysis) measurements of 20 hips indicated plastic deformation of the cups. We conclude that long-term successful cups do not migrate and have a very low rate of wear which was not affected by ageing of the polyethylene. There was no evidence that polyethylene wear alone caused mechanical loosening of the cup but high rates of wear seem to have an adverse prognostic value in terms of the long-term survival of the prosthesis.

Preoperative planning for primarytotal hip arthroplasty

Preoperative planning for total hip replacement (THR) takes place at the institutional, physician practice, and individual case levels. Patient-implant demand matching and the development of critical pathways for postoperative care are essential to the continued practice of THR in today's health care environment. Preoperative patient education speeds recovery, provides realistic expectations, and enhances the durability of the arthroplasty. Prospective evaluation of patient outcomes enables rationale assessment of new technologies and confirms the cost-effectiveness of THR in enhancing quality of life. Successful THR for a given individual demands a comprehensive assessment and optimization of the patient's general medical status. The orthopaedic evaluation focuses on leg lengths, contractures, and coexisting musculoskeletal abnormalities. appropriate preoperative radiographs are essential. Implants must be selected to optimize component fit and fill (intraosseous considerations) as well as leg length, offset, and anteversion (extraosseous relationships).The surgeon should have not only a primary intraoperative plan, but alternative plans, implants, and instruments to deal with unexpected findings or complications.

Sexual Function After Total Hip Arthroplasty

Eighty-six patients who had successful total hip replacement completed questionnaires on their sexual activity. Preoperatively, 46% of patients attributed significant sexual difficulties to their hip disease, whereas only 1% felt that their hips remained a significant source of problems postsurgery. The majority (55%) of patients were able to resume intercourse one to two months postoperation. Male patients were statistically more likely to resume intercourse sooner than their female counterparts. Patients were also questioned about which coital positions they found comfortable after arthroplasty. The supine position (patient on bottom) was the most preferred. The next most comfortable position for males was prone (patient on top), yet for female it was sidelying on the nonoperative hip. In addition, 89% of patients desired more information regarding sexual function postarthroplasty, preferably in the form of a booklet. Therefore, a booklet was written specifically for postoperative patients and their sexual partners.

Prosthetic hip failure: preliminary findings of retrospective radiograph image analysis.

We present the results of a retrospective study based on radiographs of 75 successful total hip replacements, and 103 which involved failure of the femoral component of the prosthesis. The failures were selected to exclude cases in which infection was implicated. Success was defined as absence of adverse clinical or radiological symptoms for at least 12 years after surgery. A failure was either obvious, for example, stem fracture, or defined as one which showed progressive radiological and clinical degeneration resulting in the need for revision surgery. Measurements were made on radiographs which had been obtained immediately post-operatively, so that the features measured would depend on surgical procedure rather than on any subsequent biological response. Computer image analysis has been used to make precisely defined, reproducible measurements of 58 parameters characterising the insertion of the femoral component of a standard Charnley prosthesis. These parameters include geometry of insertion, distribution of cement, surrounding bone thickness, and so on. Clinical findings, including patient weight, were also recorded with the measurements on computer disc. Preliminary statistical comparisons indicate that several of the measured parameters are of predictive value for determining the long-term success or failure of total hip replacements.

Total hip replacement in the previously septic hip.

Total hip replacement was performed in either one or two stages in thirty-three hips with active sepsis. The sepsis had followed hemiarthroplasty in six hips, open reduction with internal fixation of a fracture in eight, cup arthroplasty in one, and total hip replacement in eight hips within six years prior to the second total hip replacement. Ten additional patients had total hip replacement following destruction of the hip joint by hematogenous sepsis in nine and by infection following a shrapnel wound in one. Of these thirty-three patients, twenty-three (70 per cent) reveal no signs of infection at three to nine years after prosthetic replacement. Of the remaining ten in whom an infection developed, six had definite recurrences of the original infection, three were infected with organisms different from the original one, and one was either a local recurrence or reseeding from a persistent pyelonephritis. The success rate when the original organism was gram-positive was 78 per cent, including two of three total hip replacements done in the presence of active infection with Staphylococcus epidermidis. The success with gram-negative organisms, however, was only 58 per cent. The prosthetic failure rate was highest in patients who had had a previous infection about a total hip replacement (37 per cent) and in patients who had had a previous infection but no prior prosthetic or internal fixation devices (37 per cent). The lowest prosthetic failure rates were in patients with an infected hemiarthroplasty (16 per cent), an infection around an internal fixation device (25 per cent), or an infected cup arthroplasty. A complete and differential blood-cell count, erythrocyte sedimentation rate, aspiration arthrogram, and radiographs did not effectively predict success or failure. For gram-positive infections, the success rates were similar following either a one or a two-stage procedure. We found that the success rates could be improved by a repeat course of parenteral antibiotics after the total hip replacement even if all preoperative and intraoperative studies failed to identify an infection. Patients with a successful total hip replacement achieved much better functional results than those who had to have a Girdlestone procedure. However, all patients must be carefully assessed prior to reimplantation of a prosthesis because of the high failure rate, especially with gram-negative organisms (Pseudomonas having the gravest prognosis), even when the procedure is done in two stages.(ABSTRACT TRUNCATED AT 400 WORDS)