Subsidence Of Femoral Component Research Articles

Femoral component fixation with and without intramedullary plug. A 6-year follow-up.

A total of 113 patients underwent a cemented total hip replacement (THR) operation involving femoral component fixation either without the use of a distal intramedullary plug (n = 57, group 1) or with the plug (n = 56, group 2). We studied the femoral component fixation radiographically at on average 6 years after THR. The cement coating was assessed as technically good in 86% and 95% of groups 1 and 2, respectively. There was radiographically diagnosable loosening of the femoral component at the follow-up in 25 cases in which stems were inserted without the intramedullary plug, and in 6 cases in those with the plug (P < 0.0008), and the mean subsidence of the femoral component was 5 mm in group 1 and 1.5 mm (P < 0.0003) in group 2, respectively. Osteolytic changes around the femoral component were noticed in both groups in equal numbers and with no statistical difference. The use of a distal intramedullary plug in the cementation of the femoral stem results in a better cement coating, reduces femoral component subsidence and ameliorates the loosening rates.

Cementless Revision for Failed Cemented total Hip Arthroplasty

Sixty-two consecutive revision hip arthroplasties were carried out in 57 patients between 1986 and 1990 using the long stem Porous Coated Anatomic (PCA) prosthesis. Fifty-two hips were available for clinical and radiological review. The remainder had either died or were lost to follow-up. The average follow-up was 4.8 years (range 3-7.8 years) and the mean age was 56 years (range 25-77 years). Using the Harris Hip Score, 38/53 (73%) were regarded as good/excellent, 6/52 (11.5%) as fair and 8/52 (15.5%) as poor. The incidence of femoral component subsidence (31/52 - 60%) was a cause of concern, and accounted for two cases of late dislocation. Of the remaining six hips regarded as failures, two had been revised for acetabular graft resorption and migration of the cup while four had moderate persistent pain despite fair hip function. The authors are unable to recommend the long stem PCA prosthesis for routine use in revision hip arthroplasty.

Early radiographic results comparing cemented and cementless total hip arthroplasty

In a randomized clinical trial of cemented and cementless total hip arthroplasty, 147 patients (76 cemented, 71 cementless) have had a minimum 4-year clinical and radiographic follow-up evaluation. No revisions have been done in either group. Two cemented acetabular components were considered definitely loose and 18 were probably loose; 7 cemented stems were possibly loose at last follow-up examination. One cementless socket was considered unstable. Although cementless femoral component subsidence occurred in 10 cases, the sinkage always stabilized within 6 months, and no stem was considered unstable at last follow-up examination. Significant femoral bone resorption was rare, and so-called “spot welds” were uncommon using this titanium stem. Distal cortical hypertrophy was common, but the cause is uncertain. Osteolysis was seen around 10 cementless and 6 cemented sockets. A small area of lysis occurred in the proximal medial femoral neck in 15 cemented stems and 1 cementless stem. No cases of distal femoral lysis were seen in either group. Despite excellent clinical results with no difference between groups, the high rate of early radiographic failure of this metal-backed acetabulum should preclude its use. Osteolysis will continue to be a problem in both groups, and its prevention should remain the focus of future studies.

慢性関節リウマチに対するＨａｒｒｉｓ／Ｇａｌａｎｔｅ型セメントレスＴＨＡの臨床成績

Nineteen primary uncemented total hip arthroplasties (THAs) were performed in 15 patients with rheumatoid arthritis. Average age was 57.7 years. Four hips had an acetabular component placed with cement (Hybrid). The follow up period averaged 25.2 months (range, 6 to 61 months). Clinical evaluation based on the Japanese Orthopedic Association (JOA) score indicated significant improvement from preoperative to the most recent follow-up examination for pain. No hips required revision surgery. There was no evidence of roentgenographical failure; however, 68% of femoral and 73% of acetabular components had minor radiopaque lines and 53% of femoral components had cortical thinning in zones 2 and 6, and 74% of femoral components showed cortical atrophy in zones 1 and 7. No hips had femoral component subsidence, or acetabular component migration. Complications included only two dislocations. No deep sepsis occurred. These short term results suggest that cementless THA may be successful in rheumatoid hips. Clinical outcome is similar to that seen in our cemented THA paients, with a similar follow-up period. However, a longer follow-up study is necessary for a true evaluation of the efficacy of cementless THA in rheumatoid patients.

Revision total hip arthroplasty: The use of solid allograft

Intract solid allografts was used to augment severe bone loss in 8 acetabula and 15 femora in 22 patients who underwent revision total hip arthroplasty with noncemented implants. The average follow-up period was 4 years. The average time to radiographic union of whole acetabular allografts was 11 months. Superior migration of the allografts occurred in four patients. Varus tilt of the acetabular component within the allografts was noted in three patients. Eleven patients underwent entire proximal femoral allograft reconstruction, and four patients had femoral head allograft reconstruction. Nine patients with entire proximal femoral allografts achieved radiographic union at an average of 13 months and two failed by nonunion. Only one of the four patients with femoral head, allograft reconstruction achieved union. Femoral component subsidence was noted in seven whole proximal femoral allografts (64%). Entire proximal femoral allograft reconstruction was complicated by at least one episode of postoperative dislocation in 6 of 11 procedures. The authors recommend that femoral head allografts should be used with caution to reconstruct proximal femoral deficiencies in which structural, support is required for stability of the implant. Successful use of acetabular allografts requires that the majority of the allograft be contiguous to host bone and not to soft tissue. With entire proximal femoral reconstruction, the tip of the femoral, component should not reside at the host-graft junction. All components should be cemented into allograft bone; and revision surgery should be performed before osteolytic destruction of bone advances to the point where allograft reconstruction is required.

A prospective study of 100 consecutive harris-galante porous total hip arthroplasties: 2–5—Year results

This is a prospective study of the authors' first 100 Harris-Galante porous total hip arthroplasties (THA) that were followed for 2–5 years. The mean age of the 83 patients was 43 years. Using the Harris hip rating system, 80% of the hips were rated as excellent, 13% as good, 5% as fair, and 2% as poor at final evaluation. Eighty percent of the hips had no pain, 11% had slight or occasional pain, 8% had activity-related pain, and 1% had moderate pain. Eighty-seven percent of the hips had no limp, 8% had a slight limp, and 5% had a moderate limp. One femoral component, placed as a conversion of a loose bipolar hemiarthroplasty, has been removed for loosening. Two other hips have been reoperated, one for lengthening the femoral neck and one for changing the acetabular liner. There were no problems with acetabular screw fixation and no component migrated. Only two hips had 1 mm nonprogressive radiolucent lines in all three zones. Femoral component subsidence of 3 or more mm was measured in 16 hips, but was progressive in only 1. Radiolucent and radiodense lines were frequently seen in the nonporous coated regions of the femoral stem. Loss of proximal medial femoral bone density was seen in 59% of hips, and calcar resorption was seen in 16% of hips. Although the clinical results of this uncemented implant system were good or excellent in 93% of hips, the high incidence of femoral component subsidence is worrisome.

Uncemented Total Hip Arthroplasty in Rheumatoid Arthritis Diseases

Forty primary uncemented total hip arthroplasties (THAs) were performed in 34 patients with an average age of 41.2 years (range, 21-78 years). Four hips had one component placed with cement: three femoral, one acetabular. Diagnoses included rheumatoid arthritis (30 hips), juvenile rheumatoid arthritis (seven hips), and systemic lupus erythematosus (three hips). The follow-up period averaged 3.7 years (range, two to six years). Thirty-five percent of the patients were using corticosteroids before hip replacement and throughout the follow-up period, whereas 44% of the patients had been using steroids in the past. Additionally, 79% of the patients were taking some form of antiinflammatory medications at follow-up examination. Clinical evaluation based on a ten-point rating scale indicated significant improvements from preoperative to the most recent follow-up examination for pain (from 3.1 to 9.0), walking (4.0-7.3), function (3.5-6.0), and activity (3.0-4.9). None of the hips required revision surgery, and none are pending. There was no evidence of roentgenographic failure; however, 43% of femoral and 12.8% of acetabular components showed some minor radiolucencies with sclerotic lines. None of these involved 100% of the bone-prosthesis interface. Femoral component subsidence occurred in two hips, and acetabular component migration occurred in one hip. Complications included three (8.1%) intraoperative femoral fractures, of which two required internal fixation. One patient had postoperative, culture negative, wound drainage. No deep sepsis occurred. These findings suggest that uncemented THA may be successful in the rheumatoid patient. Pain relief, walking, function, and activity levels are similar to those seen in cemented replacements with this length of follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Performances of Ingrowth Surfaces

Since the relatively recent introduction of porous-coated implants for joint replacement applications, considerable experience has been gained concerning the efficacy of these devices. In general, the short- and intermediate-term clinical results have been satisfactory. Based on the authors' experience with retrieved components, bone ingrowth is a consistent finding in well-fixed implants, particularly in areas of rigid fixation and intimate apposition. However, a number of issues have emerged that may jeopardize the long-term success of porous-coated devices. These include femoral component subsidence, porous-surface delamination, endosteal bone loss, and proximal femoral atrophy. Improvements in design, manufacturing processes, and surgical technique can be expected to address some of the current limitations in these implant systems.

Clinical and Radiographic Experience with a Hydroxyapatite-Coated Titanium Plasma-Sprayed Porous Implant

Recent efforts to improve the interface between implant and bone have involved the use of bioactive materials, specifically hydroxyapatite (HA). HA coatings applied to implants have shown excellent clinical results at 2 years. There have been no radiolucent lines around the HA-coated implants. The long-term strength of the HA coating-substrate bone interface remains a concern as osseointegration of the HA appears to be a consistent phenomenon. This can lead potentially to an interruption between the substrate itself and the osseointegrated coating.

In Vivo Measurements of Relative Motion Between an Uncemented Femoral Total Hip Component and the Femur by Roentgen Stereophotogrammetric Analysis

Roentgen stereophotogrammetric analysis (RSA) was used to study rotation and subsidence of an uncemented polyethylene-coated femoral component for total hip arthroplasty in ten patients younger than 55 years of age. Three years postoperatively, the total subsidence averaged 2.44 mm and the internal rotation was 7.4 degrees. The rate of subsidence decreased between the observation periods, whereas the rate of rotation, after an initial significant decrease, became almost constant. One patient, who was a clinical failure and required revision arthroplasty, had a significantly higher rate of migration after six months. The pattern of subsidence in the absence of pain might be the normal reaction of bone to an uncemented prosthesis, but the continuing rotation suggests the potential for failure of the arthroplasty. The type of analysis made possible in RSA may allow early prediction of the success of arthroplasties and significantly speed the design cycle for arthroplasty components.

The Effects of the Collar on Total Hip Femoral Component Subsidence

Twenty-four preserved autopsy femurs were used to evaluate the effect of the collar and tight distal fit on noncemented femoral component subsidence, micromotion, and load to failure. Ten collared implants (five with tight and five with loose distal fit) and 14 collarless implants (seven with tight and seven with loose distal fit) were inserted with press-fit technique. They were compressively loaded in an Instron machine (Instron, Canton, Massachusetts) at 25-kg increments with 20 cycles applied at each load level. Subsidence was significantly decreased, and load to failure increased by the collar. None of the parameters was significantly affected by tight fit of the cylindrical distal stem. Tightening of the collarless implant by subsidence could not be relied upon to achieve fixation, and may not be reliable in a clinical situation. Improved rigidity of fixation and increased strength achieved by seating on the collar are distinctive advantages for pain control and biologic fixation of noncemented femoral components.

The bipolar endoprosthesis in avascular necrosis of the femoral head

The authors reviewed the clinical and radiographic results of 31 bipolar hip arthroplasties performed for avascular necrosis in 24 patients. The average patient age at the time of operation was 43 years, and the average follow-up period was 4.6 years. Using a modified Hospital for Special Surgery hip rating system, the results were excellent in eight hips, good in seven, fair in eight, and poor in eight. Eight hips had residual pain despite a satisfactory rating. Four hips have required revision. There was a correlation between the patient's age and preoperative radiographic stage and the clinical result. Abduction-adduction weight-bearing radiographs showed that only 33% of the hips had significant inner-bearing motion. Superior acetabular cartilage narrowing or migration of the acetabular component was seen in 14 hips. Femoral component subsidence occurred in seven hips.

Comparison of Charnley and T-28 Total Hip Arthroplasty

A retrospective review of a matched series of 40 Charnley and 40 T-28 total hip arthroplasties was performed. The mean follow-up period after surgery was 5 1/2 years. The clinical status and detailed radiographic appearance were carefully evaluated prior to operation, two months after operation, and at the final follow-up examination. The clinical results were similar. The Charnley femoral components tended to be positioned in a more valgus orientation than the T-28 prostheses by 2.2 degrees (p less than 0.02). After operation, the patients with T-28 prostheses had larger leg-length discrepancies than the patients with Charnley prostheses (p less than 0.01). Calcar resorption was not significantly different between the two groups, nor were subsidence of the femoral components and migration of the acetabular components. A collared T-28 femoral component has little clinical advantage over a noncollared prosthesis with respect to calcar resorption and femoral component subsidence.