Arthrokinematic Analysis of High-Impact and Large-Rotation Activities at 1 to 2 Years After Anterior Cruciate Ligament Reconstruction and Meniscal Surgery.

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is associated with a high incidence of posttraumatic osteoarthritis (PTOA). The incidence is even higher when ACLR is combined with meniscal surgery (ACLR+M). The mechanisms associated with the onset and progression of PTOA after injury and surgery are not fully understood, but altered joint biomechanics shortly after surgery are implicated.

PURPOSE: To compare the side-to-side differences in joint kinematics (ie, osteokinematics) and articular cartilage arthrokinematics at 1 to 2 years after ACLR+M during 3 demanding activities that challenge the knee with high-impact loads, large rotations, and non-sagittal-plane movements.

STUDY

DESIGN

Descriptive laboratory study.

METHODS

A total of 12 participants (8 male and 4 female) who had undergone ACLR+M at 1 to 2 years previously participated. Dynamic activities included single-leg landing, lunging, and pivoting. Tibiofemoral osteokinematic data of both knees were captured using dual fluoroscopy combined with model-based tracking. Osteokinematic analysis was conducted for 6 degrees of freedom kinematics. Cartilage arthrokinematic data, derived from magnetic resonance imaging-based cartilage models, were evaluated for tibiofemoral contact location, contact overlap, contact path, and excursion.

RESULTS

Compared with the contralateral knee, the ACLR+M knee underwent less flexion during landing (P < .001) and lunging (P = .04). It also exhibited increased anterior tibial translation during landing (P = .01) and pivoting (P = .002). We observed posterior shifts in contact location on the tibial cartilage surface and increased overlapping contact in both the medial and lateral compartments during landing and pivoting. The ACLR+M knee also exhibited increased anteroposterior excursion of the tibial contact path during lunging.

CONCLUSION

ACLR+M was associated with alterations in osteokinematics and arthrokinematics in the surgical knee, suggesting that the surgical knee does not return to normal function during demanding dynamic activities at 1 to 2 years. This study provides novel in vivo evidence of joint abnormalities under functional loading conditions experienced during everyday activities and sports. These findings enhance our understanding of early biomechanical side-to-side deviations that may contribute to PTOA.

CLINICAL RELEVANCE: Identifying abnormal knee joint mechanics at 1 to 2 years after ACLR+M during high-demand tasks emphasizes the need for targeted rehabilitation and monitoring strategies aimed at mitigating altered loading patterns that may accelerate PTOA development.