The Value of Early Active Rehabilitation on Long-Term Functional Outcomes in Neer Type-4 Valgus Impacted Proximal Humeral Fractures Treated with Open Reduction and Internal Fixation: A Retrospective Cohort Study

<b>Objectives:</b> The optimal rehabilitation protocol following open reduction and internal fixation (ORIF) for Neer type-4 valgus impacted proximal humeral fractures (VIPHF) remains controversial. This study aimed to compare the long-term efficacy and safety of early active mobilization versus conventional rehabilitation in these patients. <b>Methods:</b> We conducted a retrospective cohort study at a single tertiary hospital involving 128 patients who underwent ORIF for Neer type-4 VIPHF between January 2018 and December 2022. Participants were divided into two groups based on the rehabilitation protocol received: the Early Active Activation (EAA) group (<i>n</i> = 64), which initiated controlled active exercises on postoperative day 1, and the Conventional Rehabilitation (CR) group (<i>n</i> = 64), which followed a delayed protocol. The primary outcome was the Constant-Murley score at 24 months. Secondary outcomes included scores at 3, 6, and 12 months, pain VAS scores, active range of motion, fracture healing time, and complications. <b>Results:</b> The EAA group demonstrated significantly superior outcomes, including a higher 24-month Constant-Murley score (88.7 ± 6.5 vs. 75.3 ± 9.2, <i>p</i> < 0.001), lower VAS scores at all time points (<i>p</i> < 0.001), greater range of motion (<i>p</i> < 0.001), and shorter fracture healing time (10.2 ± 1.8 vs. 12.5 ± 2.3 weeks, <i>p</i> < 0.001). Complication rates did not differ significantly (4.7% vs. 6.3%, <i>p</i> = 0.718). <b>Conclusions:</b> For patients with surgically stabilized Neer type-4 VIPHF, early active rehabilitation initiated on postoperative day 1 was associated with significantly improved functional outcomes, accelerated recovery, and a favorable safety profile. However, these findings should be interpreted with caution due to the retrospective design, single-center setting, and potential residual confounding. Further validation through prospective, multicenter studies is recommended.