The Hip
Home » Joints » Hip » THR: Press Fit Acetabular Component

THR: Press Fit Acetabular Component



- See: Total Hip Replacement Menu:
           - acetabular component revision:
           - operative considerations for hip dyplasia
           - protrusio
           - reaming technique:
           - component insertion:
           - component position:
           - screw placement:
           - bone grafting for acetabular defects:
           - acetabular component revision:


- Discussion:
    - design of acetabular components: (see surface coating)
    - acetabular component loosening:
    - osteolysis
    - normal bone ingrowth:
            - generally for bone ingrowth to occur, component must lie within 40-50 micrometers of the acetabulum, and have enough mechanical stability (less than 40 to
                  50 micrometers) inorder for host bone ingrowht to occur;
            - Bloebaum RD, et al (1997), bone ingrowth into component averages only 12%, even though 84% of cup surface was in contact w/ periprosthetic bone;
                  - bone ingrowth was found to be uniform in all zones, most likely due to the uniform distribution of stresses from the metal backing; 
            - references:
                  - Postmortem analysis of consecutively retrieved asymmetric porous-coated tibial components.
                  - Histological and radiographic assessment of well functioning porous-coated acetabular components. A human postmortem retrieval study.   
                  - Incomplete seating of press-fit porous-coated acetabular components: the fate of zone 2 lucencies.

    - acetabular offset and latealized acetabular liner:
            - this may induce additional torque and shear at the metal osseous surface leading to loosening;
            - references:
                  - Offset acetabular components introduce torsion on the implant and may increase the risk of fixation failure.
                  - Histological and radiographic assessment of well functioning porous-coated acetabular components. A human postmortem retrieval study.
                  - Acetabular Revision With a 7-mm Lateral Offset Component Inserted Without Cement in Patients Who Have Acetabular Deficiency.
                  - Midterm Radiographic Comparison of Cementless Acetabular Shells Containing Lateralized and Nonlateralized Liners. 
    - types of press fit surfaces: 
    - acetabular liner / femoral head size: (vs metal on metal)
           - as pointed out by Jasty M, et al (1997), the thickness of the polyethylene component is especially important in metal backed press fit components;
                  - w/ smaller acetabular components consider using a 26 mm rather than a 28 mm head in order to better prevent osteolysis;
           - as noted by Cobb, et al (1997), there was no indication of early loosening of elevated rim liners at 5 years as compared to neutral liners;
           - optimally orthopaedists should be able to choose specific liners based on long term data of liner survival;
                  - Hylamer liner from DePuy is associated w/ early signs of wear and osteolytic changes.
           - references: 
                  - Wear of polyethylene acetabular components in total hip arthroplasty. An analysis of one hundred and twenty-eight components retrieved at autopsy or revision operations.
                  - Effect of femoral head size on wear of the polyethylene acetabular component.
                  - Size of the femoral head and acetabular revision in total hip-replacement arthroplasty.
                  - Effect of the elevated-rim acetabular liner on loosening after total hip arthroplasty. 
                  - Elevated-rim acetabular components. Effect on range of motion and stability in total hip arthroplasty.

                  - Complications of total hip arthroplasty associated with the use of an acetabular component with a Hylamer liner. 
                  - Impingement and loosening of the long posterior wall acetabular component.   
                  - Effect of femoral head size and abductors on dislocation after revision THA.
                  - Range of motion and stability in total hip arthroplasty with 28-, 32-, 38-, and 44-mm femoral head sizes

    - outcomes:
         - as noted by Bohm and Bosche (1998), the 11 year survivorship of press fit Harris Galante components was 97.7%;
                - there was only one case of osteolysis in this study;
                - mean postoperative inclination was 42 deg;
                - holes in the acetabular component did not correlate with pelvic osteolysis;
    - references: 
         - Survival analysis of the Harris-Galante I acetabular cup.
         - Acetabular augmentation in primary and revision total hip arthroplasty with cementless prostheses.
         - Comparison of porous-threaded and smooth-threaded acetabular components of identical design. Two- to four-year results.
         - Comparison of in vivo cementless acetabular fixation.
         - A preliminary report of the use of a cementless acetabular component with a cemented femoral component.
         - Metal-backed acetabular cups in total hip arthroplasty.
         - Further follow-up on socket fixation using a metal-backed acetabular component for total hip replacement. A minimum ten-year follow-up study.
         - Range of motion caused by design of the total hip prosthesis.
         - Hip Replacement with a Threaded Acetabular Cup. A Follow-up Study.
         - Total hip replacement with insertion of an acetabular component without cement and a femoral component with cement. Four to seven-year results.
         - Early failure of acetabular components inserted without cement after previous pelvic irradiation.
         - Cementless press-fit cup. Principles, experimental data, and three-year follow-up study.
         - Development and first experience with an uncemented press-fit cup.
         - Postmortem Analysis of Bone Ingrowth into Porous Coated Acetabular Components.   
         - Histological and radiographic assessment of well functioning porous-coated acetabular components. A human postmortem retrieval study. 
         - Fixation of acetabular cups without cement in total hip arthroplasty. A comparison of three different implant surfaces at a minimum duration of follow-up of five years. 
         - Fixation of the acetabular component: the case for cementless bone ingrowth modular sockets


- Radiographic Evaluation:
    - preop acetabular x-ray evaluation:
           - protrusio:
                  - reference:
                         - Radiographic measurements in protrusio acetabuli.
           - bone grafting for acetabular defects:
           - references:
                  - The acetabular teardrop and its relevance to acetabular migration.
                  - Bone grafting in total hip replacement for acetabular protrusion.
    - postop radiographic evaluation:
           - acetabular component loosening:
           - component position;
           - polyethylene wear:
           - osteolysis:
                  - references:
                         - Severe Osteolysis of the Pelvis in Association with Acetabular Replacement without Cement.
                         - The relationship between design, position, and articular wear of acetabular components inserted without cement and development of pelvic osteolysis
                           - Are cementless acetabular components the cause of excess wear and osteolysis in total hip arthroplasty?


- Complications:
    - acetabular fracture:
           - acetabuli should not be underreamed by more than 1 mm, especially in osteoporotic bone;
           - underreaming of the acetabulum by two milimeters may result in frx in 20-25% of cases;
           - when intra-operative fracture is recognized intra-operatively, then augment the component with as many acetabular screws as possible;
    - acetabular component loosening:
    - dislocation
    - screw insertion injuries;
    - osteolysis
    - protrusio:
    - references:
           - Periprosthetic fractures of the acetabulum during and following total hip arthroplasty.   
           - Fracture of the acetabulum during insertion of an oversized hemispherical component.
           - The elevated-rim acetabular liner in total hip arthroplasty: relationship to postoperative dislocation.



Secondary total hip replacement after fractures of the femoral neck.

Current status of acetabular fixation in primary total hip arthroplasty.

Failure of the Mecring screw-ring acetabular component in total hip arthroplasty. A three to seven-year follow-up study.

The definition and measurement of acetabular orientation.

Cementless Acetabular Fixation at Fifteen Years. A Comparison with the Same Surgeon's Results Following Acetabular Fixation with Cement.