Two-Day Spacing Outperforms 1-Hour and 1-Week Spacing in Arthroscopic Training: A Simulation-Based Randomized Controlled Trial With Functional Near-Infrared Spectroscopy Evidence.

Abstract

To compare the effectiveness of short (1 hour), medium (2 days), and long (1 week) spacing intervals in knee arthroscopic skill acquisition and retention, using behavioral and cortical activation as metrics. Right-handed orthopaedic residents with no previous arthroscopic experience were recruited and randomly assigned to Groups A (1 hour), B (2 days) and C (1 week). After initial standardized arthroscopy training on a simulator, Test 1 was conducted to assess baseline performance. All participants then completed 3 training sessions, with spacing intervals of 1 hour, 2 days, and 1 week, respectively, followed by Test 2. Test 3 was performed 1 week after the spaced training. A functional near-infrared spectroscopy device was used during Test 2 and Test 3 to measure cortical activation (presupplementary motor area, left prefrontal cortex, left primary motor cortex, right prefrontal cortex, and right primary motor cortex). A total of 30 participants were included and achieved comparable performance levels after the initial learning phase. In Test 2, Group B showed the highest total score (84.30 vs 86.30 vs 82.20, all P < .001), with shorter completion time (P^(B-C) < .001), reduced camera path length (P^(B-C) < .001), and greater activation in right primary motor cortex (P^(B-C) = .013) and left primary motor cortex (P^(B-C) = .046). In Test 3, Group A showed significant skill deterioration, whereas Groups B and C showed preserved performance (58.90 vs 87.20 vs 84.80, P^(A-B) < .001, P^(A-C) < .001). Group B outperformed Group C in completion time (P = .016) and left primary motor cortex activation (P = .004). No significant differences were observed in left prefrontal cortex or right prefrontal cortex activation between Groups B and C at either Test 2 or Test 3. A 2-day interval produced more effective arthroscopic skill training than both 1-hour and 1-week intervals with greater primary motor cortex activation. Structuring arthroscopic training schedules using day- and week-spacing intervals could enhance skill development. Off-site bimanual motor practice may further reinforce technical proficiency.