A study of the micromovement of pegged and keeled glenoid components compared using radiostereometric analysis.

In a prospective, randomized study between 2000 and 2004, 20 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with radiostereometric analysis, 10 with keeled and 10 with pegged glenoid components. The relative movement of the glenoid component with respect to the scapula was measured over a 24-month period. Three keeled and five pegged glenoids needed reaming for erosion. The largest translations occurred along the longitudinal axis (mean of 1.35 mm for keeled eroded components) (P = .017 for keeled vs pegged components and P = .013 for eroded vs non-eroded components). Both of the other translation axes showed no significant differences. The highest maximum total point movement at 24 months was 2.57 mm for keeled eroded components and 1.64 mm for pegged eroded components (P = .029 for keeled vs pegged components and P = .023 for eroded vs non-eroded components). The largest rotation was anteversion, with mean values of 5.5 degrees for keeled eroded components and 4.8 degrees for pegged eroded components (P = .658 for keeled vs pegged components and P = .90 for eroded vs non-eroded components). The mean varus tilt was 4.5 degrees for keeled eroded components compared with 2.3 degrees for pegged eroded components (P = .004 for keeled vs pegged components and P = .016 for eroded vs non-eroded components), and finally, anterior-posterior rotation mean values were 3.5 degrees for keeled eroded components and 1.1 degrees for pegged eroded components (P = .022 for keeled vs pegged components and P = .04 for eroded vs non-eroded components). In conclusion, whereas all components moved, radiostereometric analysis revealed increased migration with keeled components, exacerbated by glenoid erosion. Furthermore, a distinctive pattern of migration was identified over the 2-year period.

[1]  R. Hawkins,et al.  Total shoulder arthroplasty. , 1989, Clinical orthopaedics and related research.

[2]  M. Post.  Constrained arthroplasty of the shoulder. , 1987, The Orthopedic clinics of North America.

[3]  J. Wolf,et al.  Influence of Comorbidity on Self-Assessment Instrument Scores of Patients with Idiopathic Adhesive Capsulitis , 2002, The Journal of bone and joint surgery. American volume.

[4]  R. Cofield.  Total shoulder arthroplasty with the Neer prosthesis. , 1984, The Journal of bone and joint surgery. American volume.

[5]  I A Trail,et al.  The results of shoulder arthroplasty in patients with rheumatoid arthritis. , 2002, The Journal of bone and joint surgery. British volume.

[6]  P. Mattsson,et al.  Stability of cemented all-polyethylene keeled glenoid components. A radiostereometric study with a two-year follow-up. , 2004, The Journal of bone and joint surgery. British volume.

[7]  A. Beckett,et al.  AKUFO AND IBARAPA. , 1965, Lancet.

[8]  G. Beaupré,et al.  The influence of fixation peg design on the shear stability of prosthetic implants , 1990, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[9]  S. Toksvig-Larsen,et al.  Roentgen stereophotogrammetric analysis as a predictor of mechanical loosening of knee prostheses. , 1995, The Journal of bone and joint surgery. British volume.

[10]  C. Becker,et al.  The mineralization patterns at the subchondral bone plate of the glenoid cavity in healthy shoulders. , 2002, Journal of shoulder and elbow surgery.

[11]  G. Walch,et al.  Primary Gleno-humeral Osteoarthritis: Clinical and Radiographic Classification , 1999 .

[12]  P J Prendergast,et al.  Contact stresses in the glenoid component in total shoulder arthroplasty , 2003, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[13]  R. Churchill,et al.  Glenoid Cementing May Generate Sufficient Heat to Endanger the Surrounding Bone , 2004, Clinical orthopaedics and related research.

[14]  G. Selvik.  Roentgen stereophotogrammetry. A method for the study of the kinematics of the skeletal system. , 1989, Acta orthopaedica Scandinavica. Supplementum.

[15]  E R Valstar,et al.  Patterns of loosening of the glenoid component. , 2002, The Journal of bone and joint surgery. British volume.

[16]  J Kärrholm,et al.  RSA in the assessment of aseptic loosening. , 1996, The Journal of bone and joint surgery. British volume.

[17]  Frederick A Matsen,et al.  The Radiographic Evaluation of Keeled and Pegged Glenoid Component Insertion , 2002, The Journal of bone and joint surgery. American volume.

[18]  D. Altman,et al.  STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT , 1986, The Lancet.

[19]  P. Büchler,et al.  A finite element model of the shoulder: application to the comparison of normal and osteoarthritic joints. , 2002, Clinical biomechanics.