Defining sagittal knee phenotypes via monopedal static anterior tibial translation. Part 2: The assessment-led personalization (ALP) system for indication and correction target planning in slope-reducing osteotomy.

Abstract

Current decision-making for slope-reducing osteotomy (SRO) often relies on isolated posterior tibial slope (PTS) thresholds, potentially misidentifying patients with acquired soft-tissue decompensation or possibly overtreating those with an asymptomatic, inherently hyperlax baseline. Furthermore, rigid point-based scoring systems oversimplify the synergistic biomechanics of the anterior cruciate ligament-deficient knee. Building on the foundational 'Set-Point' theory established in Part 1, this paper introduces the assessment-led personalization (ALP) system. This unified clinical algorithm integrates the normalized percentage of absolute static anterior tibial translation (sATT%) and its side-to-side difference (ΔsATT%) with PTS laterality, generalized hyperlaxity, and injury chronicity. By mathematically calibrating raw translation data to isolate true soft-tissue decompensation from underlying osseous asymmetry, the ALP system provides a proactive, joint-preserving framework to identify high-risk phenotypes likely to fail isolated soft-tissue reconstruction and precisely refines the indications for SRO. LEVEL OF EVIDENCE: Level V.