Redox Molecules in Aging and Neurodegenerative Disorders.

In 2020, the global population with osteoarthritis (OA) reached 595 million, and a 74.9% rise in the prevalence of knee osteoarthritis is anticipated by the year 2050, posing a substantial health and economic burden []. Despite the rapid development of emerging therapeutic technologies such as platelet-rich plasma, total knee arthroplasty (TKA) is still the definitive surgical solution for end-stage knee OA []. Traditional TKA surgery adheres to the mechanical alignment principle, aiming to achieve neutral limb alignment. This principle has been widely applied in clinical practice and has demonstrated favorable long-term implant survival and satisfactory functional outcomes [, ]. However, empirical observations suggest that the indiscriminate application of mechanical alignment, without accounting for physiological differences, can disrupt native bone alignment and perturb the physiological soft tissue envelope []. In response, kinematic alignment was proposed to preserve the patient’s physiological alignment, offering a new direction for physiological joint replacement []. Current research predominantly focuses on the impact of lower limb alignment on clinical outcomes [], leaving the critical factor of medial-lateral gap balance insufficiently explored. Despite satisfactory postoperative radiographic alignment, 15–20% of patients still report symptoms such as pain and tightness []. These symptoms may be linked to improper management of soft tissue balance, potentially leading to abnormal prosthetic load distribution, reduced joint stability, and ultimately impaired functional recovery []. Previous study investigating the association between coronal ligament laxity and clinical outcomes in patients undergoing TKA have demonstrated that medial laxity ≥ 5° is negatively correlated with outcome measures, underscoring the importance of soft tissue balance []. Historically, with respect to soft tissue release during TKA, achieving absolute medial-lateral balanced gap has been considered the “gold standard” in TKA. However, it was found that in PS-TKA patients, the lateral joint gap was larger than the medial gap during both knee extension and 90° of flexion []. Another study demonstrated appropriate lateral laxity during flexion was associated with better clinical outcomes ( = 0.272,  < 0.01) [], However, the postoperative optimal soft tissue state remains uncertain. Especially for Chinese populations, the prevalence of varus limb alignment is 38.03%, higher than the neutral alignment, typically demonstrating a smaller medial gap than lateral gap due to relative tightness of the medial soft-tissue envelope [, ]. This raises an important question: in the Chinese population, where varus alignment is predominant, whether the medial-lateral gap difference is associated with postoperative clinical outcomes.