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.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, May 15, 2012 4:38 pm