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Radiology of Cemented Femoral Components


- See:
      - Types of Loosening:
      - Exam for THR Loosening:

- Grading of Cement Technique: (Barrack, et al. (1992) and Mulroy, et al. (1995))
    - Grade A: meduallary canal completely filled w/ cement (white out).
    - Grade B: a slight radiolucency exists at the bone cement interface.
    - Grade C: a radiolucency of more than 50% at the bone cement interface.
    - Grade D: a radiolucency involving more than 100% of the interface between bone and cement in any projection, including absence of 
             cement distal to the stem tip;
    - as noted by Mulroy, et al., a femoral cement mantle less than 1 mm and defects in the cement mantle are associated with early 
            loosening;
    - Improved cementing techniques and femoral component loosening in young patients with hip arthroplasty. A 12-year radiographic review.
     - Total hip arthroplasty with use of so-called second-generation cementing techniques. A fifteen-year-average follow-up study.
- Radiographic Stem Loosening:
    - note that radiolucent lines are commonly found in the lateral and anterior aspects of the proximal femur, since these areas can be difficult to 
          visualize and difficult to pressurize;
          - in the proximal 1 cm of the femur, linear radiolucencies less than 2 mm in width should not be considered to be indicative of 
                  loosening;
    - definite loosening:
          - stem fracture
          - cement fracture;
          - cement-prosthesis lucency: radiolucency at the cement component interface greater than 1 mm in width;
                 - is a definite sign of loosening if a new radiolucent line of any size apprears at the cement  prosthesis interface which was not  
                        present on initial postoperative radiographs;
                 - cement debonding between the prosthesis and the cement in zone 1 (anterolateral segment), may not necessarily correlate with 
                        poor clinical results;
          - changes in stem position:
                 - pistoning:
                 - medial midstem pivot:
                 - calcar pivot:
                 - subsidence;
                 - distal pivot:
    - probable loosening:
            - radiolucent lines: continuous radiolucency at bone cement interface;
            - typically these radiolucent lines will be surrounded by lines of increased density;
            - endosteal cavitation (linear osteolysis and focal osteolysis) are also suggestive of femoral loosening;
    - possible loosening:
            - radiolucent lines at cement bone interface from 50-100% of the total bone cement interface;

- Technical Failures Causing Loosening:
    - as noted by Kobayashi, et al (1997)., a "stove pipe" femur is a strong risk factor for radiographic loosening in cemented femoral components;



- Assessment of cement column:

     



Factors affecting aseptic failure of fixation after primary Charnley total hip arthroplasty

Short-term aseptic loosening of the femoral component in canine total hip replacement: effects of cementing technique on cement mantle grade.

Comparison between triple-tapered and double-tapered cemented femoral stems in total hip arthroplasty: a prospective study comparing the C-Stem versus the Exeter Universal early results after 5 years of clinical experience.

Femoral component loosening using contemporary techniques of femoral cement fixation.