The Effect of Acetabular Inclination on Metal Ion Levels Following Metal-on-Metal Hip Arthroplasty (original) (raw)
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Surgical Variables Influence Metal Ion Levels After Hip Resurfacing
Clinical Orthopaedics and Related Research®, 2011
Background Metal-on-metal bearings in surface arthroplasty are associated with prolonged periods of elevated ion circulation. However, there exists some controversy regarding the effect of different surgical variables on the concentration of metal ions in whole blood of patients after hip resurfacing. Questions/purposes We sought to confirm which clinical and radiographic parameters are associated with elevated levels of cobalt, chromium, and molybdenum after unilateral metal-on-metal surface arthroplasty. Methods We retrospectively reviewed 91 patients with a minimum followup of 24 months (mean, 37 months; range, 24-55 months). The clinical variables consisted of age, gender, preoperative severity of osteoarthritis, component size, and functional outcome measures using the Harris hip score and UCLA activity score. The radiographic parameters included acetabular inclination and version as well as femoral component alignment from both the anteroposterior and lateral radiographs. Results A smaller femoral head diameter was associated with larger levels of cobalt and chromium. We observed a negative correlation between ion levels and the Harris hip score or UCLA score. A larger acetabular inclination showed a direct relationship with the concentration of metal ions. Severity of preoperative osteoarthritis, acetabular version, femoral stem-shaft and valgus angle, and anterior orientation of the femoral component had no effect on the circulating metal ion levels.
The Journal of Arthroplasty, 2014
Keywords: MARS MRI metal-on-metal arthroplasty inclincation metal ions ARMD Following the global recall of all ASR metal on metal hip products, our aim was to correlate MRI findings with acetabular inclination angles and metal ion levels in patients with these implants. Both cobalt and chromium levels were significantly higher in the presence of a periprosthetic fluid collection. There was no association between the presence of a periprosthetic mass, bone marrow oedema, trochanteric bursitis or greater levels of abductor muscle destruction for cobalt or chromium. There was no association between the level of periprosthetic tissue reaction and the acetabular inclination angle with any of the pathologies identified on MRI. The relationship between MRI pathology, metal ion levels and acetabular inclination angles in patients with ASR implants remains unclear adding to the complexity of managing patients.
Blood metal ion concentrations after hip resurfacing arthroplasty
The Journal of Bone and Joint Surgery. British volume, 2009
There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available hip resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) hip resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p < 0.05). Cr and Co were more strongly influenced by the position of the acetabular component in the case of the ASR, with an increase in metal ions observed at inclinations > 45° and anteversion angles of < 10° and > 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an i...
Journal of Bone and Joint Surgery - British Volume, 2008
We examined the relationships between the serum levels of chromium and cobalt ions and the inclination angle of the acetabular component and the level of activity in 214 patients implanted with a metal-on-metal resurfacing hip replacement. Each patient had a single resurfacing and no other metal in their body. All serum measurements were performed at a minimum of one year after operation. The inclination of the acetabular component was considered to be steep if the abduction angle was greater than 55°.
Clinical Orthopaedics and Related Research®, 2011
Background Many factors affect the blood metal ion levels after metal-on-metal (MOM) hip arthroplasty. The main surgically adjustable variable is the amount of coverage of the head provided by the cup which is a function of the inclination and version angles. However, most studies have used plain radiographs which have questionable precision and accuracy, particularly for version and large diameter metal heads; further, these studies do not simultaneously assess version and inclination. Thus the relationship between version and blood metal ions levels has not been resolved. Questions/purposes We determined whether cup inclination and version influence blood metal ion levels while adjusting for age at assessment, gender, body mass index, horizontal femoral offset, head size, manufacturer hip type, and Oxford hip score. Patients and Methods We prospectively followed 100 individuals (51 females, 49 males) with unilateral MOM hip resurfacing who underwent clinical assessment, CT scanning, and blood metal ion measurement. Multiple regression analysis was used to determine which variables were predictors of blood metal ion levels and to model the effect of these variables. Results Only cup inclination, version angles, and gender influenced blood cobalt or chromium levels. Cobalt and chromium levels positively correlated with inclination angle and negatively correlated with version angle. The effect of changes in version angle was less than for inclination angle. Based on our observations, we developed a formula to predict the effect of these parameters on metal ion levels. Conclusions Our data suggest insufficient cup version can cause high blood metal ions after MOM hip arthroplasty. We were unable to show that excessive version caused high levels.
BMC Musculoskeletal Disorders, 2012
Background Metal-on-metal hip resurfacing is an alternative to metal-on-metal total hip arthroplasty, especially for young and physically active patients. However, wear which might be detected by increased serum ion levels is a matter of concern. Methods The aims of this preliminary study were to determine the raise of metal ion levels at 2-years follow-up in a prospective setting and to evaluate differences between patients with either resurfacing or total hip arthroplasty. Furthermore we investigated if the inclination of the acetabular component and the arc of cover would influence these findings. Therefore, 36 patients were followed prospectively. Results The results showed increments for Co and Cr in both implant groups. Patients treated with large-diameter total hip arthroplasty showed fourfold and threefold, respectively, higher levels for Co and Cr compared to the resurfacing group (Co: p
Journal of Arthroplasty, 2017
Background: The recent experiences with adverse local tissue reactions (ALTR) have highlighted the need to establish what are normal serum levels of cobalt (Co), chromium (Cr), and titanium (Ti) after hip arthroplasty. Methods: Serum Co, Cr, and Ti levels were measured in eighty nonconsecutive patients with wellfunctioning unilateral THA and compared among four bearing surfaces: ceramic on ceramic (CoC); ceramic on polyethylene (CoP); metal on polyethylene (MoP), and dual mobility (DM). The preoperative and most recent UCLA and WOMAC scores were compared among the different bearing surfaces. Subgroup analysis was also completed using metal vs. ceramic heads to compare metal ion levels and patient reported outcomes. Categorical variables were compared among the four bearing couples using Fisher exact tests and between metal and ceramic heads using Chi-squared tests. Continuous variables were compared between bearing surface groups using Kruskal-Wallis tests and between metal and ceramic heads using Wilcoxon rank-sum tests. Spearman correlation coeffecient was used measure the correlation between PROM and metal ion levels. Results: No significant difference was among serum Co and Cr levels between the four bearing surface groups (p= 0.0609 and p= 0.1577). The preoperative and most recent UCLA activity and total WOMAC scores were not significantly different among different bearing surfaces. Secondary
Ten-Year Outcome of Serum Metal Ion Levels After Primary Total Hip Arthroplasty
The Journal of Bone and Joint Surgery (American), 2013
We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%). Ten patients (hybrid group) had received a hybrid total hip replacement that consisted of a modular cobalt-alloy femoral stem with a cobalt-alloy femoral head that had been inserted with cement and a titanium acetabular socket that had been inserted without cement. Nine patients (cobalt-chromium [CoCr] group) had received an implant with an extensively porous-coated modular cobalt-alloy femoral stem and femoral head along with a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Eight patients (titanium group) had undergone insertion of a proximally porous-coated modular titanium-alloy femoral stem with a cobaltalloy femoral head and a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Thirteen patients (control group) from the original control group of patients who had not received an implant served as control subjects. Serum metal levels were measured with use of high-resolution sector field inductively coupled plasma mass spectrometry. The hybrid total hip arthroplasty group had mean cobalt levels that were 3.2 times higher at 120 months than they were at baseline, and the cobalt levels in that group were significantly higher than those in the titanium total hip arthroplasty group at thirty-six, sixty, eighty-four, ninety-six, and 120 months (p < 0.01). The hybrid group had mean chromium levels that were 3.9 times higher at 120 months than they were at baseline, and the CoCr total hip arthroplasty group had chromium levels that were 3.6 times higher at 120 months than they were at baseline. The serum titanium levels were higher in the titanium group at all follow-up time intervals as compared with the levels in all other groups, and the level in the titanium group at 120 months was eighteen times higher than it was at baseline (p < 0.01). Patients with well-functioning primary metal-on-polyethylene total hip replacements had elevated serum metal levels for as many as ten years postoperatively. Furthermore, metal release at the modular femoral head-neck junctions, rather than passive dissolution from porous ingrowth surfaces, was likely the dominant source of serum cobalt and chromium. continued *Original Publication Jacobs JJ, Skipor AK, Patterson LM, Hallab NJ, Paprosky WG, Black J, Galante JO. Metal release in patients who have had a primary total hip arthroplasty. A prospective, controlled, longitudinal study.
Levels of metal ions after small- and large-diameter metal-on-metal hip arthroplasty
The Journal of bone and joint surgery. British volume, 2003
Metal-on-metal (MOM) bearings for hip arthroplasty are increasing in popularity. Concern remains, however, regarding the potential toxicological effects of the metal ions which these bearings release. The serum levels of cobalt and chromium in 22 patients who had undergone MOM resurfacing arthroplasty were compared with a matched group of 22 patients who had undergone 28 mm MOM total hip arthroplasty (THA). At a median of 16 months (7 to 56) after resurfacing arthroplasty, we found the median serum levels of cobalt and chromium to be 38 nmol/l (14 to 44) and 53 nmol/l (23 to 165) respectively. These were significantly greater than the levels after 28 mm MOM THA which were 22 nmol/l (15 to 87, p = 0.021) and 19 nmol/l (2 to 58, p < 0.001) respectively. Since the upper limit for normal patients without implants is typically 5 nmol/l, both groups had significantly raised levels of metal ions. MOM bearings of large diameter, however, result in a greater systemic exposure of cobalt an...