Knee Joint Line Obliquity Causes Tibiofemoral Subluxation That Alters Contact Areas and Meniscal Loading

Background: Little scientific evidence is available regarding the effect of knee joint line obliquity (JLO) before and after coronal realignment osteotomy. Hypotheses: Higher JLO would lead to abnormal relative position femur on tibia, a shift contact areas, elevated pressures. Study Design: Descriptive laboratory study. Methods: 10 fresh-frozen human cadaveric knees (age, 59 ± 5 years) were axially loaded 1500 N in materials testing machine with tilted 0°, 4°, 8°, 12° varus (“downhill” medially) valgus, at 0° 20° flexion. The mechanical compression axis was aligned center tibial plateau. Contact pressure area recorded by sensors inserted between tibia below menisci. Changes femoral plane obtained an optical tracking system. Results: Both medial lateral caused significant tibiofemoral subluxation distribution changes. Medial (varus) subluxate medially down slope plateau, vice versa for (valgus) downslopes ( P < .01), giving 6-mm range subluxation. areas peak moved 12 mm 8 across condyles, onto downhill meniscus “uphill” spine. had only small effects maximum Conclusion: A 4° change during load bearing mediolateral slid plateau abut eminence also rest meniscus. This large movements pressures each compartment. Clinical Relevance: These results provide important information understanding consequences creating clinical practice terms osteotomy planning JLO. provides guidance choice single- or double-level Excessive alteration may cause articulation chondral meniscal loading.