Pending Failure in Hard-hard Total Hip Arthroplasty
Condition: Infection and Inflammatory Reaction
MeSH terms: Inflammation
Study type: Observational

Summary: 
      During last 6 years approximately 10.000 ceramic balls and 5.000 ceramic liners have been
      implanted in the region Emilia-Romagna in Italy (4 million Every single year approximately
      60.000 hip prostheses are implanted in Italy. Quality of life of patients after surgery is
      very good, as widely demonstrated in the literature. On the basis of data produced by the
      only complete hip register in Italy that is run in our Lab (RIPO, Register of Orthopedic
      Implants in the Region Emilia-Romagna) survival rate of primary total hip prosthesis is 95.6%
      at 9 years. Reasons for revision are mainly aseptic loosening of one or both components (40%
      of the total) and dislocation (26%), being the latter much more frequent in the first two
      years. Less frequently revision is due to sepsis (7% of the total),bone fracture (11%),
      prosthesis fracture (3%) or pain (3%). Revision is relates, among the others, to
      prosthesis-related factors, such as fixation to bone and articular coupling. In our
      experience, during the last ten years 32% of implants had both articular component in ceramic
      , 34% had metal head and plastic liner, 24% ceramic head and plastic liner, 10% both
      components in metal.

      Each solution has strengths and weakness and they have been identified and clinically applied
      in order to overcome step by step limitations observed in the previous one. The most recent
      are the hard-on-hard bearings, that is ceramic on ceramic and metal on metal. These two
      solutions, beside very promising results on wear resistance, show some peculiar failures:
      respectively fracture of the ceramic component and hypersensitivity induced by metal ions.

      Aim of research proposal is to investigate two uncommon and less investigated early symptoms
      of failure:

        -  'noising hip' in ceramic on ceramic total hip arthroplasty

        -  pain without radiographic signs of loosening in metal on metal total hip arthroplasty
           These two situations are extremely relevant, as they prelude to a failure of the
           prosthesis. If clearly identified they could represent a powerful tool in early
           diagnosis of pending failure To reach this goal our patients wearing hard-on-hard total
           hip arthroplasty, suffering for described symptoms will undergone a specific diagnostic
           procedure.

      The first group will be studied through CT scan of the patients to evaluate impingement or
      instability of the prosthesis, and a needle aspiration for synovial fluid. The fluid will be
      examined to identify ceramic wear debris, according to a method of separation and analysis in
      scanning electron microscopy that was set in our Lab.

      Sound will be recorded by means of a wearable sensor set capable of recording the articular
      noise produced during level walking. This instrumentation will be coupled to motion analysis
      technology.

      This would make possible a diagnostic approach able to correlate the involved factors to
      clinical occurrences, on the basis of the recorded frequencies.

      -Second group will be studied through the dosage of circulating ions, deriving from the
      articular surfaces and through the histological classification of vasculitis in periimplant
      tissues. There is increasing evidence, indeed that locale release of submicron particles worn
      out from articular surfaces can release metal ions (mainly Chromium and Cobalt) responsible
      for lymphocyte local infiltration. In particular CD20 positive B lymphocyte and CD3 positive
      T lymphocyte and sometimes CD68 positive plasma cells are present. The cells could justify
      the development of pseudotumors in metal-on metal hip prosthesis.

      Data collected from patients matched to in vitro results will allow us to to avoid or at
      least propose a more appropriate timing for revision surgery.
    

Detailed description: 
      Every single year approximately 60.000 hip prostheses are implanted in Italy. Quality of life
      of patients after surgery is very good, as widely demonstrated in clinical experience and in
      the literature. On the basis of data produced by the only complete hip register in Italy,
      that is run in our Lab (RIPO, Register of Orthopedic Implants in the Region Emilia-Romagna
      http://ripo.cineca.it) survival rate of primary total hip prosthesis is 95.6% at 9 years.
      Reasons for revision are mainly aseptic loosening of one or both components (40% of the
      total) and dislocation (26%), being the latter much more frequent in the first two years.
      Less frequently revision is due to sepsis (7% of the total),bone fracture (11%), prosthesis
      fracture (3%) or pain (3%).

      Revision can be related, among the others, to prosthesis-linked factors, such as fixation to
      bone and articular coupling.

      In the experience of RIPO, during the last ten years 32% of implants had both articular
      component in ceramic, 34% had metal head and plastic liner, 24% ceramic head and plastic
      liner, 10% both components in metal.

      Each solution has strengths and weakness and they have been identified and clinically applied
      in order to overcome step by step limitations observed in the previous one.

      Alumina ceramic-on-ceramic (COC) bearings have been shown to produce substantially less wear
      debris than traditional metal/ceramic on polyethylene bearings. In addition, the alumina
      ceramic material itself is essentially bioinert in both bulk and particulate form . Unlike
      metal-on-metal bearings (MOM), this bearing couple does not release metal ions into the body
      either from the articulation or from breakdown of wear debris. Weakness of ceramic-on-ceramic
      bearings are represented by brittleness of the material. Ceramic can fracture, even in very
      few cases, due to trauma or to malpositioning. Beside this occurrence of noise during gait of
      patients can be extremely disturbing for patient itself, leading to request of revision.
      These two solutions represent more recent proposal that technology suggested to overcome
      problem of wear.

      Hard components on plastic has the unsolved problem of wear debris, leading to osteolysis and
      consequent failure of he im plant. The problem has only partially solved by the introduction
      of cross linked polyethylene, aimed to improve tribological behaviour of the plastic.

      Rizzoli Institute is the only public mono-specialistic research hospital in Italy. Nearly 500
      hip prosthesis revisions are performed here every year in the structure. Due to its high
      specialization difficult cases from all the country are treated here, not on ly when anatomy
      of the patient is damaged (dislocation of the hip, post traumatic arthritis) but .even more
      frequently when failure of the implant occurred.

      Aim of research proposal is to investigate two uncommon and less investigated early symptoms
      of failure:

        -  'noising hip' in ceramic on ceramic total hip arthroplasty

        -  pain in metal on metal total hip arthroplasty Even if not numerically so important,
           these two situations are extremely relevant, as they prelude to a failure of the
           prosthesis. If clearly identified they could represent a powerful tool in early
           diagnosis of pending failure.

      The first point will be studied through CT scan of the patients to evaluate impingement or
      instability of the prosthesis, and a needle aspiration for synovial fluid. The fluid will be
      examined to identify ceramic wear debris, according to a method of separation and analysis in
      scanning electron microscopy that was set in our Lab.

      Sound will be recorded by means of a wearable sensor set capable of recording the articular
      noise produced during level walking. This instrumentation will be coupled to motion analysis
      technology, so as to provide a temporal correlation between the recorded noise and the gait
      cycle. It will be developed in the first phase of the project. In parallel surface analyses
      will be conducted on retrievals that are stored in the Lab since 2000, in one of the biggest
      retrieval study ever conducted in our country. Type of damage, surface roughness of both
      ceramic components will be analysed and compared to clinical data.

      Finally the study will be completed in vitro, using an hip simulator, to reproduce the
      possible clinical scenarios leading to hip noise, record, and analyse it in a reproducible
      and robust manner. This would make possible a diagnostic approach able to correlate the
      involved factors to clinical occurrences, on the basis of the recorded frequencies. Second
      point will be studied through the dosage of circulating ions, deriving from the articular
      surfaces and through the histological classification of vasculitis in periimplant tissues.
      There is increasing evidence, indeed that locale release of submicron particles worn out from
      articular surfaces can release metal ions (mainly Chromium and Cobalt) responsible for
      lymphocyte local infiltration. In particular cluster of differentiation antigen 20 (CD20)
      positive B lymphocyte and cluster of differentiation 3 (CD3) positive T lymphocyte and
      sometimes cluster of differentiation antigen 68 (CD68) positive plasma cells are present. The
      cells could indicate a specific phlogistic condition responsible for pain and eventually
      subsequent revision.

      Data collected on studied population will allow a better understanding of the two phenomena
      and possibly will suggest new therapeutic approaches to the problems.
    

Intervention name(s): Metal ions dosage and evaluation of local/systemic reaction; Noise registration and metal ions determination; Metal ions dosage, evaluation of local/systemic reaction, noise registration
Intervention type(s): Other; Other; Other
Intervention description(s): Dosage of Chromium and Cobalt on several biological matrices deriving from each patients.
Determination of local/systemic reaction; Dosage of Vanadium and Titanium on several biological matrices deriving from each patients.
Determination of range of noise; Dosage of Chromium, Cobalt, Vanadium and Titanium on several biological matrices deriving from each patients.
Determination of local/systemic reaction
Other intervention name(s): Controls comparison for variables considered
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        All the patients (no septic) afferent to our ward and wearing hip prosthesis MoM or CoC. A
        group of control patients, waiting for primary total hip arthroplasty.
      
Biospecimen description: 
      Whole blood, serum, synovial fluid, urines, periprosthetic tissues, at -80°C
    
Keywords: Internal Left Hip Prosthesis; Internal Right Hip Prosthesis