Hip Replacement In Young Patients Research Articles

Proximal load transfer with a stemless uncemented femoral implant

Bone stock preservation is crucial when performing total hip replacement in young patients. The aim is to save good bone stock for a possible revision procedure. Furthermore, there is an increasing demand from young and active patients to receive a new joint which allows a normal or nearly normal life style. With this in mind, we began, in 1993, to develop a new femoral implant. The purpose of this ultra-short stem was a physiologic strain distribution on the proximal femur with a proximal load transfer from the implant to the femoral bone. Main features were an almost complete absence of the diaphyseal portion of the stem, a well defined lateral flare with load transfer on the lateral column of the femur, and a very high femoral neck cut. These innovations resulted in a conservative implant on both the bone stock and the soft tissues. This implant, in the first years, was recommended only for young and active patients. Over the last thirteen years, this project has undergone several modifications but the basic principles of the implant have remained the same. In the present review, we present the rationale, the surgical technique and the clinical and experimental results so far obtained with this implant.

Metal-on-metal resurfacing of the hip in patients under the age of 55 years with osteoarthritis

The results of conventional hip replacement in young patients with osteoarthritis have not been encouraging even with improvements in the techniques of fixation and in the bearing surfaces. Modern metal-on-metal hip resurfacing was introduced as a less invasive method of joint reconstruction for this particular group. This is a series of 446 hip resurfacings (384 patients) performed by one of the authors (DJWM) using cemented femoral components and hydroxyapatite-coated uncemented acetabular components with a maximum follow-up of 8.2 years (mean 3.3). Their survival rate, Oxford hip scores and activity levels are reviewed. Six patients died due to unrelated causes. There was one revision (0.02%) out of 440 hips. The mean Oxford score of the surviving 439 hips is 13.5. None of the patients were told to change their activities at work or leisure; 31% of the men with unilateral resurfacings and 28% with bilateral resurfacings were involved in jobs that they considered heavy or moderately heavy; 92% of men with unilateral hip resurfacings and 87% of the whole group participate in leisure-time sporting activity. The extremely low rate of failure in spite of the resumption of high level occupational and leisure activities provides early evidence of the suitability of this procedure for young and active patients with arthritis.

Total hip replacement in younger patients: survival rate after avascular necrosis of the femoral head.

A high risk of loosening has been reported in replacements performed because of avascular necrosis. To study cementless total hip replacement (THR) in younger patients with avascular necrosis (AVN), we analyzed retrospectively the outcome in 129 cases: 46 Mittelmeier monobloc ceramic hips (22 cases with AVN), and 83 Zweymüller total hip systems (35 cases with AVN) clinically and radiographically. At follow-up, 17 Mittelmeier prostheses (10 AVN) and 4 Zweymüller prostheses (none with AVN) had been revised. The diagnosis did not affect the implant survival, but the Zweymüller THR fared better than the Mittelmeier system. The main reason for revision of Mittelmeier implants was aseptic loosening, 3 of 4 Zweymüller revisions were necessary due to polyethylene wear. This difference was confirmed by the radiographic evaluation of the still intact implants: Zweymüller THR showed better values for signs of osseointegration, radiolucent lines around the implants and migration, but more acetabular wear. None of these differences was affected by the AVN diagnosis. We could not confirm that AVN is a risk factor in total hip replacement.

Clinical and functional outcome of the Thrust Plate Prosthesis: short- and medium-term results

Objectives. The purpose of this study was to objectively assess the functional outcome after implantation of a Thrust Plate Prosthesis. Design. This retrospective study compared the gait patterns of 33 patients to a control group. Background. Few studies have been published about this type of prosthesis describing clinical and radiographic outcome. Even though the evaluation of the functional outcome is a commonly accepted way to measure the success of an implant it has not been reported in previous studies. Methods. Beside clinical ( SF-36, and Harris Hip Score) and radiographic evaluation subjects were examined by three dimensional gait analysis and surface electromyography from seven leg and trunk muscles bilaterally. Results. The average Harris Hip Score was 85.7 points, and the SF-36 only differed significantly from controls regarding physical functioning. The radiography showed considerable radiolucencies under the Thrust Plate. Kinematic parameters indicated a slight impairment of the operated limb. The analysis revealed a decreased hip (28.2%) and knee (51.2%) range of motion during gait. The joint moments on the operated side were reduced in hip (72%) and knee abduction (59%) in comparison to controls. The average electromyographic parameters indicated a significantly higher mean and peak amplitude of the tensor fasciae latae (mean 56%, peak 54%), and gluteus medius (mean 33%, peak 21%) and a lower peak activity of the gluteus maximus (19%). Conclusions. The results indicate a generally good functional outcome even though a slightly asymmetrical loading was observed. No major limitations in physical functioning and health-related quality of life was seen. The radiographic signs of loosening might indicate difficulties in achieving the proximal load transfer of this implant. Relevance The data provided in this study may serve to establish the Thrust Plate Prosthesis as an alternative procedure in total hip replacement in younger patients.

Total hip replacement with a cementless acetabular component and a cemented femoral component in patients younger than fifty years of age.

We have been using hybrid total hip arthroplasty (a cementless acetabular component and a cemented stem) in young patients. The purpose of this study was to determine the prevalence of aseptic loosening, polyethylene wear, and osteolysis after the use of this technique. We studied a prospective consecutive series of sixty-four primary hybrid total hip replacements in fifty-five patients younger than fifty years old. There were forty-three men and twelve women; the average age at the time of the index operation was 43.4 years. The average duration of follow-up was 9.4 years. We used a cementless acetabular component without screw-holes and a cemented femoral component with a 22-mm head in all hips. Clinical follow-up with use of Harris hip ratings and radiographic follow-up were performed at six weeks; at three, six, and twelve months; and yearly thereafter. The sequential annual linear and volumetric wear rates were measured, and bone-remodeling and osteolysis were assessed. The mean preoperative Harris hip score was 44 points, which increased to 95 points at the time of final follow-up. No hip had aseptic loosening. One hip (2%) was revised because of late infection. The average linear wear (and standard deviation) was 0.96 +/- 0.066 mm, with an average annual rate of 0.096 +/- 0.013 mm. The average volumetric wear was 364.7 +/- 25.2 mm (3), with an average annual rate of 43.4 +/- 3.5 mm (3). Six hips (9%) had an osteolytic lesion of <1 cm in diameter in the calcar femorale (zone 7). Our results show that a hybrid arthroplasty with a cementless acetabular component and a smooth cemented femoral component (Ra, 0.6 mm) is effective for primary total hip replacement in young patients. Although there was no aseptic loosening and a low prevalence of osteolysis at the latest follow-up evaluation, the high rates of linear and volumetric wear of the polyethylene liner in these young patients remain a concern.

Total Hip Replacement in Young Patients with Ankylosing Spondylitis

Total Hip Replacement in Young Patients with Ankylosing Spondylitis

Long-term results of total hip replacement in young patients who had ankylosing spondylitis. Eighteen to thirty-year results with survivorship analysis.

We determined the long-term results of total hip replacement in a series of young patients who had ankylosing spondylitis. Between 1966 and 1978, forty-three Charnley low-friction arthroplasties were performed in twenty-four patients who had an average age of 28.8 years (range, nineteen to thirty-nine years) at the time of the operation. There were seventeen men and seven women. The average duration of follow-up for the series was 22.7 years (range, one month [a perioperative death] to 30.3 years). Four patients (seven hips) had died an average of 12.6 years (range, one month to 18.7 years) after the operation. The twenty surviving patients had clinical and radiographic follow-up until the time of writing or until both of the original components had been revised. All patients had substantial relief of pain and improvement of function and the range of motion of the joint. Twenty-one patients (88 per cent; thirty-nine hips) were completely free of pain (6 points, according to the scale of Merle d'Aubigne and Postel), and the remainder had only slight discomfort (5 points). Ten acetabular components and one femoral component were revised because of aseptic loosening, and one patient had a revision of both components because of late deep infection. Three additional femoral components were revised during a revision operation for a loose acetabular component. Although the femoral components were not loose, they had been in place for more than ten years and it was thought likely that the bearing surface was damaged. The average time to revision was 13.3 years (range, 4.0 to 20.3 years). At an average of 22.7 years, thirty-eight (88 per cent) of the original femoral components and thirty-two (74 per cent) of the original acetabular components remained in situ. The average annual rate of acetabular wear was 0.12 millimeter for the entire series. Only six hips (14 per cent) had minor heterotopic ossification, and none of the hips had clinically important ossification (class III or IV according to the system of Brooker et al.). To our knowledge, the present report describes the largest series of total hip arthroplasties, with the longest duration of follow-up, in young patients who had ankylosing spondylitis. Survivorship analysis with use of the Kaplan-Meier method revealed that the probability of survival of the femoral component (with 95 per cent confidence intervals) was 91 per cent (83 to 99 per cent) at twenty years and 83 per cent (72 to 94 per cent) at thirty years. The probability of survival of the acetabular components was 73 per cent (61 to 84 per cent) at twenty years and 70 per cent (57 to 83 per cent) at thirty years. The probability that both components would survive was 91 per cent (82 to 100 per cent) at ten years, 73 per cent (61 to 84 per cent) at twenty years, and 70 per cent (57 to 83 per cent) at thirty years. The Charnley low-friction arthroplasty provided consistently good long-term results, with a low rate of complications and revisions, in this group of young patients.

Outcome of Primary total Hip Replacement in Patients Less than 50 Years Old

We reviewed 33 primary total hip replacements in 24 patients younger than 50 years old. The mean age was 39.5 years and the follow-up averaged 6.1 years. There were 15 men and 9 women. Twenty-five hip replacements were cemented and 8 were uncemented. The most common hip pathology was osteonecrosis of the femoral head (36%), followed by rheumatoid arthritis (27%) and osteoarthritis (21%). Good pain relief was obtained in 70% of hips. Thigh pain developed in 2 uncemented hips and another had increasing hip pain. Function was good in 64% and 67% had good hip mobility. The best results were obtained in osteonecrosis of the femoral head, followed by osteoarthritis and rheumatoid arthritis. The commonest indication for revision was loosening of the acetabular component. Survival analysis of the 25 cemented hips showed a failure of 35% at 6 years and 9.1% at 8 years. Total hip replacement in young patients provides good pain relief and function although there is a limited time expectancy for good results.

Fixation and effect on bone strain pattern of a stemless hip prosthesis

Given the relatively short survival time of total hip replacement in young patients, a different concept of femoral implant was designed and evaluated biomechanically prior to clinical application. The femoral component has no intramedullary stem and fits into an angular resection of the femoral neck. A trans-trochanteric screw provides immediate strong fixation. A comparative biomechanical study with cadaver femora and a dynamic hip simulator was performed. The study had three objectives. (1) The strains generated under loading in the intact proximal femur were compared to those generated in the presence of the experimental implant and a classic cemented implant. (2) The short-term stability of the experimental prosthesis under loading conditions encountered during fast walking was evaluated. (3) Most importantly, the implant design was improved in the light of the experimental observations prior to any clinical trial. Indeed, the prototype underwent several important modifications in the course of the study. With the modified design, later used in a clinical trial, it was demonstrated that if accurate fit and position of the prosthesis were provided, fixation remained sound for over one million loading cycles with peak loads of three times the body weight. The measured interface micromotion was compatible with direct bone apposition and ingrowth. No statistical difference was found between the strain measurements obtained before and after implantation of the experimental prosthesis whereas significant stress shielding was observed with a stemmed, cemented prosthesis.

Long-term results of core decompression for ischaemic necrosis of the femoral head

We have studied the long-term results of core decompression as the sole treatment for Ficat stages I, II and III ischaemic necrosis of 128 femoral heads in 90 patients. The 5-, 10- and 15-year survival rates for the three stages were respectively: stage I 100%, 96% and 90%; stage II 85%, 74% and 66%; and stage III 58%, 35% and 23%. At a mean follow-up of 11 years (4.5 to 19), 55 hips had failed (43%). No further surgery had been needed for 88% of stage-I, 72% of stage-II and 26% of stage-III hips; but despite the generally satisfactory clinical results, 56% of the hips had progressed radiographically by at least one Ficat stage. Complications of the core procedure included four fractures, all from postoperative falls, and one head perforation due to technical error. We conclude that core decompression delays the need for total hip replacement in young patients with ischaemic necrosis.

Total hip arthroplasty in juvenile rheumatoid arthritis. Two to eleven-year results.

From 1971 to 1980, forty-five patients with juvenile rheumatoid arthritis had eighty-three cemented total hip replacements at The Hospital for Special Surgery and North Carolina Memorial Hospital. Thirty-four of these patients, with sixty-two involved hips, returned for examination and radiographs. The average age of these thirty-four patients at the time of surgery was twenty-six years, and twenty-seven of them, with forty-nine involved hips, were thirty years old or less. The average length of follow-up was six years (range, two to eleven years), with forty-one hips having been followed for five to eleven years. According to The Hospital for Special Surgery hip-rating system, thirty hips were rated excellent; nineteen, good; nine, fair; and four, poor. Of the four hips with a poor result, two (in the same patient) had severe heterotopic ossification with ankylosis postoperatively, and two had required revision: one for acetabular loosening six years after replacement and the other for a broken stem of the femoral component ten years postoperatively. Radiographic review of the sixty-two hips demonstrated progressive radiolucencies or migration of 26 per cent of the acetabular components and 8 per cent of the femoral components. The frequency of acetabular migration or progressive radiolucencies was related to the postoperative position of the component relative to the position of the true acetabulum. These results were somewhat better than those in other reports on cemented total hip replacement in young patients. The difference is probably related to the lower average weight and decreased activity level of patients with juvenile rheumatoid arthritis.