Wednesday, November 16, 2011

Silent soft tissue pathology is common with a modern metal-on-metal hip arthroplasty.

I mentioned that I would reprint this journal article as my revision surgery is an exemplar case to illustrate  the issues and outcomes with metal on metal  patients who have no pain.  I had a revision based in part on the soft tissue damage identified by the MRI.  The post op report, certainly confirmed that I needed this operation for several reasons:
  • A hole the size of a golf ball was found in the ilium that was fixed with a bone graft.
    • "large cavetry leison" found  on my ilium and this defect was contained.
  • Significant amount of inflammatory fluid within the hip joint
    • all evacuated
  • Diffuse, hypertrophic, synovitic reaction within the joint itself
    • this was thoroughly debrided (cleansed.) 
There have been a number of reports in the literature describing  inflammatory masses around painful MoM atheroplasties that can  be grouped under a variety of headings such as:
  • ayseptic lymphocytic-dominated vasculitis (ALVAL)
  • pseudotumors
  • adverse reaction to metal debris (ARMD)

Although these "lesions" have been previously described in patients investigated for pain, there have been no studies of these lesions in unselectected series of patients including those with no or few symptoms as is the case with me.  "It is not known whether these lesions may occur in the absence of symptoms."

This study which was just undertaken early this year, confirms that these things can occur without pain symptoms and I believe my results confirm their observations as well.  I had no pain prior to surgery which might have served as a warning sign to the presence of these underlying issues.

I have not received the tissue path reports yet but I will get them soon. (It is like pulling teeth to get op reports in the hospital.  You must be very persistent.  I get the sense that these reports are guarded in some kind of shroud of secrecy.  No one should have an operation without reading the post op report.  Why would you pay thousands of dollars for an operation with no documentation on what was done????  Kinda crazy if you think about it.  Ditto for the path report.  These are your reports and by law, you are entitled to read them.)
Acta Orthop. 2011 Jun;82(3):301-7. Epub 2011 Apr 19.

Source

The Centre for Hip Surgery, Wrightington Hospital, Lancashire, UK. hwj@doctors.net.uk

Abstract

BACKGROUND AND PURPOSE:

Adverse reactions to metal debris have been reported to be a cause of pain in metal-on-metal hip arthroplasty. We assessed the incidence of both symptomatic and asymptomatic adverse reactions in a consecutive series of patients with a modern large-head metal-on-metal hip arthroplasty.

METHODS:

We studied the early clinical results and results of routine metal artifact-reduction MRI screening in a series of 79 large-head metal-on-metal hip arthroplasties (ASR; DePuy, Leeds, UK) in 68 patients. 75 hips were MRI scanned at mean 31 (12-52) months after surgery.

RESULTS:

27 of 75 hips had MRI-detected metal debris-related abnormalities, of which 5 were mild, 18 moderate, and 4 severe. 8 of these hips have been revised, 6 of which were revised for an adverse reaction to metal debris, diagnosed preoperatively with MRI and confirmed histologically. The mean Oxford hip score (OHS) for the whole cohort was 21. It was mean 23 for patients with no MRI-based evidence of adverse reactions and 19 for those with adverse reactions detected by MRI. 6 of 12 patients with a best possible OHS of 12 had MRI-based evidence of an adverse reaction. [12= best score and 60 is the worst score.]

INTERPRETATION:

We have found a high early revision rate with a modern, large-head metal-on-metal hip arthroplasty. MRI-detected adverse reactions to metal debris was common and often clinically "silent". We recommend that patients with this implant should be closely followed up and undergo routine metal artifact-reduction MRI screening.

Additional information from this study found in the discussion section  of the paper:

(1) "One of the most concerning findings in this was that MRI based evidence of an adverse reaction to metal debris does not appear to correlate with symptoms. 

(2) In fact, some of the highest levels of patient  satisfaction were in those patients with the worst MRI/MAR findings.

(3) One quarter of the patients with the best OHS (12) had MRI based evidence of ARMD.

(4) This suggests that even a policy of frequent clinical reviews would not detect patients developing soft tissue complications until extensive damage had occurred.

(5) It is unclear why there is no pain.

(6) We believe it is preferable to detect ARMD soft tissue damage and fluid filled cavities at an early stage before the damage becomes extensive and irreversible.

I will continue to address the  potential serious  nature of ignoring early testing with MoM implants even if there is no pain present.

Remember the title of this study which was just published this year:  "Silent Soft Tissue Pathology is common with modern metal-on-metal implants". 



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