Tibiofemoral Joint Contact Area and Pressure After Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction

PurposeThe purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees.MethodsTibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0°, 15°, 30°, and 45° of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees).ResultsWhen compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30° and 15° of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15° of flexion on the medial tibiofemoral joint and at 0° and 15° of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15° of flexion on the lateral tibiofemoral joint.ConclusionsSB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles.Clinical RelevanceOur findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.