Radiographic Signs Of Loosening Research Articles

Effect of femoral head size on polyethylene wear and synovitis after total hip arthroplasty: A sonographic and radiographic study of 39 patients

Background and purpose The role of synovitis and high fluid pressure in the loosening process after total hip arthroplasty has gained increasing attention. We investigated the correlation between head size, polyethylene wear, and capsular distention.Patients and methods We analyzed 39 unrevised, radiographically stable hips that had been operated with 28 or 32 mm femoral heads 10 years earlier because of osteoarthritis. We evaluated radiographic signs of loosening, linear and volumetric polyethylene wear, body mass index, activity level, and age. Sonographic examination was performed to measure capsular distance i.e. the distance between the prosthetic femoral neck and the anterior capsule.Results Linear wear was 0.09 mm/year and 0.18 mm/year in the 28 mm and 32 mm groups, respectively (p < 0.001). The volumetric wear was 51 mm3/year and 136 mm3/year (p < 0.001) and the capsular distance was 13 mm and 17 mm, respectively (p < 0.001). There was a correlation between linear wear (r = 0.54), volumetric wear (r = 0.62), and capsular distance (p < 0.001).Interpretation Wear was greater for the larger femoral head and was correlated to capsular distension.

Exeter total hip arthroplasty with matte or polished stems

To compare implant survival rates after total hip arthroplasty with Exeter matte or polished stems and to determine the relationship of synovitis/joint effusion to signs of implant loosening and stem type. The first part of the study included retrospective revision rate analysis of 118 primary hip replacements performed during 1991-1995. Two different designs of Exeter stems were used: matte surface stems during 1991-1995 (matte surface group--47 cases), and polished stems during 1992-1995 (polished stem group--71 cases). During the second part of the study, 24 patients (11 in polished stem group and 13 in matte stem group) were prospectively examined with radiography and sonography. Sonography was performed in order to evaluate capsular distension, i.e. the distance between prosthetic femoral neck and anterior capsule. Capsular distension depends on synovitis and/or synovia in prosthetic hip. The relationship between capsular distension, stem type, and radiographic signs of loosening was assessed. For the first part of our study, total implant survival was 78% with matte stems and 61% with polished stems 13 years postoperatively (P=0.27). Stem survival was 82% for matte stems, and 88% for polished stems (P=0.54). In the second part of study, a significant relationship between increased capsular distension and cup loosening was determined (P=0.04). We did not find significant difference in capsular distension when compared matte and polished stems. Implant survival rates did not differ between the groups. The relationship between capsular distension and cup loosening was statistically significant.

Acetabular Revision with the Contour Antiprotrusio Cage

The Contour cage introduced in 1999 was designed to improve fixation and provide a surface for bone ongrowth. To determine whether the rates of radiographic loosening and/or revision have been reduced with the Contour design, we retrospectively reviewed the medical records and radiographs of 29 patients (average age, 68.1 years) undergoing 31 acetabular revisions with a Contour cage. The minimum followup was 24 months (mean 30 months, range, 24-58 months). Based on the Paprosky classification, two hips were Type 2B, seven were Type 3A, and 22 were Type 3B. Two hips (7%) were revised for loosening; one of these two was also infected. An additional five hips (16%) had signs of radiographic loosening. The mean Harris hip score improved from 45 to 80; functional scores improved less than the pain scores. Only 14 hips (45%) had an excellent or good clinical result and three of these 14 hips had radiographic signs of loosening; presuming these three hips eventually fail, only 35% of the hips had a good or excellent result. We found an association between number of previous surgeries and radiographic loosening and revision. Our data suggest the Contour cage offers little advantage over other antiprotrusio cages and highlight the substantial limitations of current methods available for treating patients with extensive acetabular bone loss.

Five-year Follow-up of Socket Movements and Loosening After Revision With Impacted Morselized Allograft Bone and Cement: A Radiostereometric and Radiographic Analysis

In 1999, we reported on the 2-year results of a series of 21 first-time socket revisions using impacted morselized allograft bone. Seven still migrated between 1.5 and 2 years. Seventeen remained for the current 5-year follow-up. No socket had been rerevised. Five sockets showed signs of radiographic loosening. These 5 cases also exhibited radiographic signs of allograft resorption as well as high rates of socket migration and rotation as measured by radiostereometric analysis. Of the 6 remaining sockets that had migrated between 1.5 and 2 years, 3 stabilized and 3 were among those with signs of radiographic loosening. Fifteen patients (15 hips) revealed pain reduction at the 5-year follow-up. Three had slight pain on walking that disappeared immediately at rest (pain score 4). All the others revealed either no pain (pain score 6) or slight pain that disappeared with activity (pain score 5). No pattern of early socket migration according to radiostereometric analysis could be identified, predicting later socket migration or loosening. The rate of cases with signs of radiographic loosening (29%, 5/17) was comparable to that reported by the Nijmegen group but the follow-up was shorter in the current study. The rate of cases with signs of radiographic loosening was comparable to both conventionally cemented socket revisions and cementless revisions. The future will show if further sockets loosen and if the loose sockets up to date will end up in rerevisions.

Uncemented STAR total ankle prostheses.

The feasibility of replacing the ankle joint has been a matter of speculation for a long time. In recent years, the designs of ankle prostheses have been improved, and three designs, all used without bone cement, currently dominate the market. However, documentation of the clinical results of the use of these prostheses is sparse. We reviewed the intermediate-term results of fifty-one consecutive Scandinavian Total Ankle Replacements (STAR). Between 1993 and 1999, fifty-one consecutive ankles were replaced with an uncemented, hydroxyapatite-coated STAR total ankle prosthesis. Clinical examination for the present study was performed by one surgeon who had not taken part in the operations. Standardized radiographs were used. Complications and failures were recorded, and patient satisfaction and functional outcome scores were determined for all patients with an unrevised implant. Twelve ankles had to be revised. Seven were revised because of loosening of at least one of the components; two, because of fracture of the meniscus; and three, for other reasons. A component was exchanged in seven of the twelve revisions, whereas the ankle was successfully fused in the other five. An additional eight ankles had radiographic signs of loosening. The thirty-nine unrevised ankles (thirty-seven patients) were examined after thirty-six to ninety-seven months (median, fifty-two months). The patient was satisfied with the result after thirty-one of the ankle replacements, somewhat satisfied after two, and not satisfied after six. The median Kofoed score increased from 39 points before the surgery to 70 points at the time of the follow-up examination. A median follow-up score of 74 points was recorded when the system described by Mazur et al. and the AOFAS (American Orthopaedic Foot and Ankle Society) system were used. The median range of motion was approximately the same preoperatively and postoperatively. The estimated five-year survival rate, with revision for any reason as the end point, was 0.70. When radiographic loosening of either component was used as the end point, the estimated five-year radiographic survival rate was significantly better for the last thirty-one ankles treated in the series (p = 0.032). Total ankle replacement may be a realistic alternative to arthrodesis, provided that the components are correctly positioned and are of the correct size. However, the risks of loosening and failure are still higher than are such risks after total hip or total knee replacement.

Dosages sanguins de métaux chez 48 patients porteurs d’une prothèse totale de hanche en chrome-cobalt à couple métal-polyéthylène

Purpose of the study Component wear and dissemination of wear debris, particularly with metal-on-metal combinations, is the predominant long-term complication of total hip arthroplasty. The purpose of our work was to search for metal particles released when using the metal-on-polyethylene combination by analyzing serum levels of chromium (Cr), cobalt (Co), nickel (Ni), and molybdium (Mo) in patients with a metal-on-polyethylene chromium-cobalt total hip arthroplasty. We compared the observed levels with those observed in a control population and studied changes as a function of signs of loosening. Material and methods During a thirty-month period, 53 patients with degenerative hip disease underwent total hip arthroplasty. The same implant, PVL ®, being used for all hips. Forty-eight patients were available for analysis at a minimum follow-up of 32 months. Results of the clinical and radiological examination of the operated hip were recorded. Serum metal levels were assayed by mass spectrometry on total blood samples. Patient activity was determined with the Devane classification and hip function with the Postel-Merle-d’Aubligné score; walking distance was recorded in kilometers. Signs of prosthetic loosening were identified on plain radiograms (AP and lateral views) searching for femoral and/or acetabular lucent lines, cement fracture, granuloma. The control group included 56 patients scheduled for total hip arthroplasty. Non-parametric statistical analysis was used to search for correlations between the clinical, radiological, and biological parameters. Results At mean 44 months follow-up, 17% of the patients had a fair or mediocre function score and 37% had radiological signs of femoral component loosening. Serum cobalt increased significantly in the implanted group (serum cobalt ≥ 0.60 μg/L in 50% of patients) compared with the control group (serum cobalt ≥ 0.60 μg/L in 9%) (P < 0.001, Mann-Whittney test). Increased serum cobalt was highest in patients with radiographic signs of loosening. This significant difference was not found for other metals. Patient activity, hip function, and follow-up were not correlated with serum levels. Discussion Serum cobalt appears to be a good biological marker of prosthetic function although intra- and inter-individual variations are influenced by assay technique, metal ion solubility, and metal dissemination in the organism. The metal-on-metal combination does not appear to be the only friction couple which increases the serum level of metal ions. Our results do not allow defining a time of latency between onset of radiographic signs and increased serum levels.

Neutrophils are active in total joint implant loosening

Polymorphonuclear neutrophils (PMN) are the first cells to take part in the local foreign body reaction in aseptic loosening of endoprostheses. The aim of this study was to evaluate the systemic host reaction to total joint replacement by measuring the production of nitric oxide by neutrophils before and after total joint replacement. Blood samples were collected from 33 patients (27 hips and 6 knees) before surgery, and 2 weeks, 2 months and 2.5-3 years after surgery. The levels of nitric oxide produced by PMN were measured by the method described by Markert et al. (1994). Patients reporting pain in the region of the implant 3 years after surgery, and also patients with radiographic signs of loosening, had higher production of NO in the early period and 3 years after the implantation than those with good clinical results. We propose that elevated levels of nitric oxide production by PMNs may serve as a marker of total joint prosthesis loosening.

Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip.

Total joint replacement in patients suffering from developmental dysplasia of the hip poses specific technical difficulties due to insufficient bone stock at the site of the original and secondary acetabulum and a narrow, cranially displaced proximal femur. Twelve hips with severe congenital dislocation (4 Crowe type II, 5 type III, 3 type IV) were treated with cementless, porous structured total hip replacement. The cup was implanted at the anatomic height, a femoral segment was resected below the minor trochanter to reduce the femoral component in all cases. One femoral component was exchanged for a longer stem after 2 months due to insufficient fit and fill. After a mean follow-up of 5.1 years, there were no further revisions or radiographic signs of loosening. No cup was revised or loose radiographically. Harris hip score (mean) improved from 36 to 82 points, mean leg length discrepancy was reduced from 5.4 to 1.3 cm. The cementless technique described is useful in cases of severe congenital dislocation of the hip when the cup is implanted at the anatomic level, and implant reduction is not possible despite thorough soft-tissue release or not advisable because of excessive limb lengthening. A reconstruction of the original joint center and good mid-term results are demonstrated.

UNCEMENTED STAR TOTAL ANKLE PROSTHESES

The feasibility of replacing the ankle joint has been a matter of speculation for a long time. In recent years, the designs of ankle prostheses have been improved, and three designs, all used without bone cement, currently dominate the market. However, documentation of the clinical results of the use of these prostheses is sparse. We reviewed the intermediate-term results of fifty-one consecutive Scandinavian Total Ankle Replacements (STAR). Between 1993 and 1999, fifty-one consecutive ankles were replaced with an uncemented, hydroxyapatite-coated STAR total ankle prosthesis. Clinical examination for the present study was performed by one surgeon who had not taken part in the operations. Standardized radiographs were used. Complications and failures were recorded, and patient satisfaction and functional outcome scores were determined for all patients with an unrevised implant. Twelve ankles had to be revised. Seven were revised because of loosening of at least one of the components; two, because of fracture of the meniscus; and three, for other reasons. A component was exchanged in seven of the twelve revisions, whereas the ankle was successfully fused in the other five. An additional eight ankles had radiographic signs of loosening. The thirty-nine unrevised ankles (thirty-seven patients) were examined after thirty-six to ninety-seven months (median, fifty-two months). The patient was satisfied with the result after thirty-one of the ankle replacements, somewhat satisfied after two, and not satisfied after six. The median Kofoed score increased from 39 points before the surgery to 70 points at the time of the follow-up examination. A median follow-up score of 74 points was recorded when the system described by Mazur et al. and the AOFAS (American Orthopaedic Foot and Ankle Society) system were used. The median range of motion was approximately the same preoperatively and postoperatively. The estimated five-year survival rate, with revision for any reason as the end point, was 0.70. When radiographic loosening of either component was used as the end point, the estimated five-year radiographic survival rate was significantly better for the last thirty-one ankles treated in the series (p = 0.032). Total ankle replacement may be a realistic alternative to arthrodesis, provided that the components are correctly positioned and are of the correct size. However, the risks of loosening and failure are still higher than are such risks after total hip or total knee replacement.

Hip revisions with impacted morselized allograft bone and cement. Patient outcome, prosthetic fixation and risks.

144 consecutive hip revisions performed with morselized allograft bone and cement were followed up to 5 years after surgery. In 49 hips patient outcome was evaluated with the Nottingham Health Profile (NHP) questionnaire and Charnley hip scores in 47 hips prosthetic fixation was evaluated with radiostereometry (RSA)and in all 144 hips risks and complications were recorded using a prspective protocol. Patient outcome regarding pain, physical mobility and sleep at 4 years after revision was comparable to that of primary hip replacements. The correlations between NHP and Charnley pain and physical mobility scores were weak to moderate. RSA index examination should be done as early as possible after surgery. The Exeter stem subsides within the cement mantle and in revisions additional subsidence of the stem-cementbeam occurs relative to the femur. All stems and most sockets migrated, mostly early after revision, without correlation to the grade of bone stock deficiency; one third of the prosthetic components still migrated between 1.5 and 2 years postoperatively. 1 of 15 stems had aseptic loosening according to RSA while the other had migrated only marginally between the 2-year and 5-year follow-up examinations. 5 of 17 sockets had signs of radiographic loosening (radiolucent line >2mm; these sockets were also among those showing the most pronounced migration and rotation at the 5-year follow-up. Neither for the stems nor for the sockets did early migration pattern predict future prosthetic movements. In a pilot study free weight bearing was practised and the migration of the stem and socket was similar to that shown among patients who practised restricted weight bearing for 3 months after revision. Concomitant disease, large bone stock deficiency, intraoperative femoral cortical window or perforation increased the risk for femoral fracture but all 9 hips but could be managed without lasting morbidity.

The Harrington reconstruction for advanced periacetabular metastatic destruction: good outcome in 32 patients.

We report the outcome in 32 patients operated on for advanced periacetabular metastatic destruction, where all but 2 had Harrington class III destruction. The patients were operated on using the Harrington reconstruction technique, where threaded pins and cement and a total hip replacement are used to reconstruct the acetabulum and ilium. The median survival was 11 (0-106+) months. 13 patients lived for a year or more. At follow-up after 1 year, 10 of the 13 were free of pain at rest and weight-bearing, 6 were walking with and 7 without support, and 11 lived outside a health care facility. 2 patients died within 2 weeks of surgery, both of excessive peroperative bleeding. 2 patients had dislocations, 1 developed a deep infection, and 2 patients deep vein thrombosis. There were no complications caused by erroneous pin placement or intraoperative thromboembolic incidents. There were no mechanical failures, or radiographic signs of loosening, of the pelvic components. The Harrington reconstruction technique is an effective and long-lasting method to relieve pain and restore function in patients with advanced periacetabular metastatic destruction.

Outcome after cup hemiarthroplasty in the rheumatoid shoulder: a retrospective evaluation of 39 patients followed for 2-6 years.

33 rheumatoid patients, treated with hemispherical cup resurfacing hemiarthroplasty of the shoulder without medullary fixation (6 bilaterally), were reviewed after mean 4.4 (2-6) years. The median Constant score was 30 (15-79), mean proximal migration of the humerus 55 (SD 5.2) mm and mean glenoid erosion 2.6 (SD 1.7) mm. Proximal migration and glenoid erosion did not correlate with shoulder function or pain. Radiographic signs of loosening (changes in cup inclination combined with changes in cup distance above the greater tuberosity) occurred in one quarter of the shoulders. At follow-up, 26 patients were satisfied with the procedure, despite poor shoulder function and radiographic deterioration.

Early Subsidence of the Exeter Femoral Stem within the Cement Mantle in Primary Arthroplasties and in Revisions Using Impacted Allografts and Cement: A Roentgen Stereophotogrammetric Analysis

In five primary hip arthroplasties and in six revisions with impacted, morselized allografts and cement, roentgen stereophotogrammetric analysis (RSA) was planned to be used to measure the subsidence of the polished and double-tapered Exeter femoral stem, relative both to the cement and the femur. Only in two primary arthroplasties and in two revisions could the tantalum markers be adequately imaged for RSA evaluation. The stems in the primary arthroplasties subsided 1.4 to 2.0 mm and all the subsidence occurred within the cement mantle. The two revisions subsided 1.9 to 3.1 mm within the cement mantle, but there was also a slight subsidence of the cement in relation to the femur, 0.5 to 0.4 mm, respectively. No radiographic signs of stem loosening were found in any of the hips. Our findings of subsidence of the Exeter femoral stem within the cement mantle with no radiographic signs of loosening are in accordance with those reported by the Exeter group. The present technique using tantalum markers in the medioproximal aspect of the cement mantle must be considered as difficult.

Radiographic assessment of cup migration and wear after hip replacement.

Methods are needed for accurate measurement of acetabular cup migration and wear after hip replacement. The EBRA (Ein Bild Röntgen Analyse) method was recently introduced as computerized method for radiographic assessment of acetabular cup migration. In this study, various standard methods for measuring migration were evaluated and compared to radiostereometry (RSA), which has proved to be highly accurate. A subroutine for wear measurement was developed and added to the EBRA method. Of the standard methods, Nunn's method was the best for migration measurement and Livermore's the best for wear measurement. Measurements with EBRA were better than the standard methods. Pelvic tilt seemed to be the main source of error in measurements. The effect of pelvic tilt was evaluated experimentally. EBRA detected and excluded tilted radiographs, the errors of measurement being smaller with EBRA than with standard methods. The precision of the input procedure, repeated radiographic examination, the intra- and interobserver errors were assessed. Apart from the digital input of the data, EBRA was better than the standard methods. Normal values concerning acetabular cup migration and wear should be obtained from long-term surviving hip replacements, without radiographic signs of loosening. No method of measurement detected evidence of changes in the wear-rate and in migration over time. EBRA showed cold-flow in some cups, but did not provide additional information in the long-term. Nunn's method for migration measurements and Livermore's method for wear are recommended in clinical practice. EBRA is more accurate and should be used for studies of new implant designs that have passed the preclinical and, preferably, radiostereometric analysis. RSA is unsurpassed and is recommended for early clinical follow-up in a limited number of patients.

Total Hip Arthroplasty with the Charnley Prosthesis in Patients Fifty-five Years Old and Less. Fifteen to Twenty-one-Year Results*

Data on 240 primary Charnley total hip arthroplasties, performed in 211 patients from October 1968 to July 1974, were recorded prospectively. Fifty-two prostheses were implanted in forty-six patients who were thirty-four to fifty-five years old, and 188 prostheses were implanted in 165 patients who were more than fifty-five years old. The results for the younger patients were compared with those for the older patients. Twenty hips were revised over-all, and all five of the infections and four of the five fractures of the femoral stem that occurred in this group were in the older patients. However, the rate of aseptic loosening was similar for the two age-groups (three of the hips in the younger patients and five in the older patients). The probability of revision after twenty years for the two groups, as determined with Kaplan-Meier analysis, was 11.7 per cent for the younger patients and 10.7 per cent for the older patients. There was no significant difference between the two groups with regard to either the number of revisions or the percentage of patients who had radiographic signs of loosening. The median Charnley hip scores during the course of the study were also similar for the two groups. We recommend that Charnley low-friction arthroplasty be used even in younger patients, as the long-term results were excellent and were comparable with those in the elderly age-group.

Polyethylene wear in Scanhip arthroplasty with a 22 or 32 mm head: 62 matched patients followed for 7-9 years.

We measured radiographic polyethylene wear in patients with Scanhip arthroplasty and no clinical or radiographic signs of loosening. The patients were divided into 2 groups according to head sizes. 32 patients (33 hips) had an implant with a 22 mm and 30 patients (34 hips) with a 32 mm head. They were followed for 7-9 years. The groups were matched for diagnosis, sex, weight, age, and time of follow-up. The mean linear wear with a 22 mm head was 1.1 mm and with a 32 mm head 1.5 mm (p 0.004), which corresponds to a yearly wear rate of 0.15 mm and 0.18 mm, respectively. The mean difference in volumetric wear was greater, 420 mm3, as compared to 1239 mm3.

Bony atrophy after mega total hip replacement for bone tumors. 11 cases followed for 3-15 years.

We followed 11 patients 3-15 years after a cemented mega total hip replacement for a proximal femoral bone tumor. 7/8 survivors had good function and only occasional pain. 1 hip had been revised because of deep infection and in 1 case the cup had been exchanged because of aseptic loosening. 2 patients had been operated on because of local recurrence of the tumor. At follow-up, 1 patient had radiographic signs of loosening of the stem after 7 years. There was in 8 cases a pronounced athropy of the femoral cortical bone, not correlated to loosening of the stem.

Total hip replacement for juvenile chronic arthritis

We review the results of 96 primary total hip replacements in 54 patients with juvenile chronic arthritis at five years or longer after surgery. The mean age at operation was 16.7 years (range 11.25 to 26.6); the follow-up period averaged 11.5 years. The clinical results in terms of pain, range of movement, mobility and function are presented. A revision procedure was required in 24 hips (25%) in 18 patients at an average of 9.5 years after the primary operation. A further 17 hips had radiographic signs of loosening. The factors thought to contribute to this relatively high failure rate in patients with juvenile chronic arthritis are discussed.

Polyethylene synovitis following canine total hip arthroplasty: Histomorphometric analysis

The synovial membrane response to polyethylene wear debris was analyzed in canine total hip arthroplasties (THA). Fifty-four THAs were performed in healthy, mature dogs. None of the arthroplasties demonstrated clinical or radiographic signs of loosening. Synovial membrane biopsies were harvested 4 (n=13), 6 (n=5), 8 (n=8), 12 (n=15), and 24 (n=6) months after surgery and were scored for inflammation, polyethylene (PE) wear debris, histiocyte density, and membrane thickness. The amount of PE wear debris tended to increase with time. However, the inflammatory changes within the joint capsule and synovial membrane did not progress, and the total thickness of the alveolar and surface layers decreased ( P=.008). It appears that the amount of wear debris at 2 years in canine hip arthroplasties, without evidence of loosening, is well tolerated by the joint capsule.