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Patellar height relevance in opening-wedge high tibial osteotomy
M H El Amrani1, B Lévy, S Scharycki
1Service de chirurgie orthopédique et traumatologique, centre hospitalier intercommunal de Villeneuve-Saint-Georges, 40, allée de la Source, 94190 Villeneuve-Saint-Georges, France. hicham.elamrani@chiv.fr
Orthopaedics & Traumatology, Surgery & Research : OTSR
|February 23, 2010
Summary
Opening-wedge high tibial osteotomy (HTO) can decrease patellar height, potentially impacting knee function. Pre-operative patellar height is crucial, with low levels (<0.6 CD ratio) not recommended for HTO.
Area of Science:
- Orthopedic surgery
- Biomechanics
- Knee joint research
Background:
- Opening-wedge high tibial osteotomy (HTO) is used for medial knee osteoarthritis.
- Decreased patellar height post-HTO can complicate function and future knee replacement.
- Pre-operative patellar height is a key factor in predicting functional outcomes.
Purpose of the Study:
- To assess the impact of opening-wedge HTO on patellar height.
- To evaluate the relationship between altered patellar height and functional outcomes.
- To identify pre-operative patellar height thresholds for HTO suitability.
Main Methods:
- Retrospective analysis of 40 opening-wedge HTOs in 36 patients with medial osteoarthritis and varus deformity.
- Pre- and post-operative measurements of patellar height (Caton-Deschamps, Insall-Salvati, Blackburne-Peel ratios), tibial slope, and HKA angle.
- Functional outcomes assessed using the International Knee Society (IKS) scale.
Main Results:
- Patellar height significantly decreased by 10-15% post-HTO (p < 0.0001).
- No correlation found between osteotomy opening angle and patellar lowering.
- While moderate patellar height decrease did not affect function, severe lowering (patella infera) was linked to poorer outcomes.
Conclusions:
- Medial opening-wedge HTO leads to a predictable decrease in patellar height.
- Pre-operative patellar height below 0.6 (Caton-Deschamps ratio) is a contraindication for this procedure.
- Careful pre-operative assessment of patellar height is essential for successful HTO outcomes.
