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Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement.

Reito A, Elo P, Nieminen J, Puolakka T, Eskelinen A - Acta Orthop (2015)

Bottom Line: Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI.A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare.However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

View Article: PubMed Central - PubMed

Affiliation: a Coxa Hospital for Joint Replacement , Tampere , Finland .

ABSTRACT

Background and purpose: There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors.

Patients and methods: 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles.

Results: The prevalence of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that "preoperative diagnosis other than osteoarthrosis" was the strongest predictor of the presence of fatty atrophy.

Interpretation: Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

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Related in: MedlinePlus

Box plot showing median WB Cr levels, interquartile range (boxes), and 95% CIs (whiskers) with outliers (circles), presented according to grade of g. medius atrophy.
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Figure 0003: Box plot showing median WB Cr levels, interquartile range (boxes), and 95% CIs (whiskers) with outliers (circles), presented according to grade of g. medius atrophy.

Mentions: Clinical and radiological details of patients are given in Table 1. There was no statistically significant difference in prevalence of atrophy between g. minimus and g. medius muscles (p = 0.6) (Table 2). Atrophy in g. maximus was, however, less common than atrophy in g. minimus (p < 0.001) or in g. medius (p < 0.001) (Table 2). Elevated WB Cr values (> 5 ppb) were detected in 48 patients (18%) and elevated WB Co values were detected in 130 patients (49%). In general, muscle atrophy was equally common in patients with elevated WB Cr or Co values as in those patients with normal blood metal ion levels (Figure 2, see Supplementary data). Moderate-to-severe g. minimus muscle atrophy was more common in patients with WB Cr levels exceeding 5 ppb than in those with levels of less than 5 ppb (p = 0.02). No other significant differences were observed between patients with elevated and non-elevated blood metal ion levels. Interestingly, median WB Cr levels were higher in cases without g. medius atrophy than in cases with mild or moderate-to-severe atrophy (2.4 ppb as opposed to 1.75 ppb and 1.80 ppb, respectively) (p = 0.02) (Figure 3). No other statistically significant differences in median WB Cr and WB Co levels were observed in relation to grade of atrophy in other muscle groups (all p > 0.05).Figure 1.


Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement.

Reito A, Elo P, Nieminen J, Puolakka T, Eskelinen A - Acta Orthop (2015)

Box plot showing median WB Cr levels, interquartile range (boxes), and 95% CIs (whiskers) with outliers (circles), presented according to grade of g. medius atrophy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940588&req=5

Figure 0003: Box plot showing median WB Cr levels, interquartile range (boxes), and 95% CIs (whiskers) with outliers (circles), presented according to grade of g. medius atrophy.
Mentions: Clinical and radiological details of patients are given in Table 1. There was no statistically significant difference in prevalence of atrophy between g. minimus and g. medius muscles (p = 0.6) (Table 2). Atrophy in g. maximus was, however, less common than atrophy in g. minimus (p < 0.001) or in g. medius (p < 0.001) (Table 2). Elevated WB Cr values (> 5 ppb) were detected in 48 patients (18%) and elevated WB Co values were detected in 130 patients (49%). In general, muscle atrophy was equally common in patients with elevated WB Cr or Co values as in those patients with normal blood metal ion levels (Figure 2, see Supplementary data). Moderate-to-severe g. minimus muscle atrophy was more common in patients with WB Cr levels exceeding 5 ppb than in those with levels of less than 5 ppb (p = 0.02). No other significant differences were observed between patients with elevated and non-elevated blood metal ion levels. Interestingly, median WB Cr levels were higher in cases without g. medius atrophy than in cases with mild or moderate-to-severe atrophy (2.4 ppb as opposed to 1.75 ppb and 1.80 ppb, respectively) (p = 0.02) (Figure 3). No other statistically significant differences in median WB Cr and WB Co levels were observed in relation to grade of atrophy in other muscle groups (all p > 0.05).Figure 1.

Bottom Line: Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI.A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare.However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

View Article: PubMed Central - PubMed

Affiliation: a Coxa Hospital for Joint Replacement , Tampere , Finland .

ABSTRACT

Background and purpose: There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors.

Patients and methods: 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles.

Results: The prevalence of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that "preoperative diagnosis other than osteoarthrosis" was the strongest predictor of the presence of fatty atrophy.

Interpretation: Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

Show MeSH
Related in: MedlinePlus