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- Document type:
- Journal Article
- Author(s):
- Yang, Justin S; Fulkerson, John P; Obopilwe, Elifho; Voss, Andreas; DiVenere, Jessica; Mazzocca, Augustus D; Edgar, Cory M
- Title:
- Patellofemoral Contact Pressures After Patellar Distalization: A Biomechanical Study.
- Abstract:
- To measure the patellofemoral contact pressure in early flexion after a tibial tubercle distalization osteotomy.Ten matched-pair fresh-frozen cadaveric knees were studied. The average Blackburne-Peel ratio of the native knees was 0.91. The knees were placed on a testing rig, with a fixed femur and tibia mobile through 90° of flexion. Individual quadriceps heads and the iliotibial band were separated and loaded with 205 N in anatomic directions using a weighted pulley system. A straight tubercle distalization osteotomy of 1 cm was performed and fixed with screws, with and without a lateral release. Patellofemoral contact pressures were measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of flexion using pressure-sensitive films on the medial trochlea and lateral trochlea. Contact force, area, and pressure were measured in the following states: (1) in the native knee, (2) after distalization, and (3) after distalization with lateral release.The average Blackburne-Peel ratio after distalization was 0.64. Tibial tubercle distalization resulted in a 6-fold increase in mean contact pressure at 0° (0.15 MPa vs 0.90 MPa, P < .001) and a 55% increase at 10° of flexion (0.70 MPa vs 1.09 MPa, P = .02). Mean contact pressure was similar from 20° to 90° of flexion (P > .1). After distalization, the total contact area was significantly higher at 0° of flexion (17.7 mm vs 58.4 mm, P = .02). Lateral release after distalization did not significantly change contact pressure (P > .21).Our results suggest that patella baja, as a result of excessive patellar distalization, can cause increased patellofemoral contact pressures during early flexion at 0° and 10°. No changes were seen in contact pressure from 20° to 90°.Care should be taken to prevent excessive distalization of the patella to avoid patella baja and increased patellofemoral contact pressures during early flexion.
- Journal title abbreviation:
- Arthroscopy
- Year:
- 2017
- Journal volume:
- 33
- Journal issue:
- 11
- Pages contribution:
- 2038-2044
- Language:
- eng
- Fulltext / DOI:
- doi:10.1016/j.arthro.2017.06.043
- Pubmed ID:
- http://view.ncbi.nlm.nih.gov/pubmed/28844344
- Print-ISSN:
- 0749-8063
- TUM Institution:
- Fachgebiet Sportorthopädie (Prof. Imhoff)
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