Abstract
<title>Abstract</title> <p> Purpose To investigate the incidence, anatomical distribution, and temporal characteristics of musculoskeletal pain associated with prolonged face-down positioning (FDP) during the first 24 hours after pars plana vitrectomy (PPV) with intraocular tamponade, and to evaluate its association with postoperative positional adherence. Methods In this prospective observational study, 199 patients who underwent PPV with silicone oil or gas tamponade between August 2025 and January 2026 were enrolled. Posture-related pain was assessed every 6 hours using the Numeric Rating Scale (NRS), while FDP adherence was recorded at 2-hour intervals during the first 24 postoperative hours. Pain incidence, intensity, anatomical distribution, and temporal patterns were analyzed according to both chronological time periods (00:00–05:59, 06:00–11:59, 12:00–17:59, and 18:00–23:59) and postoperative intervals (0–6 h, 6–12 h, 12–18 h, and 18–24 h). Results Among the 199 participants, 124 (62.3%) reported posture-related musculoskeletal pain within the first 24 postoperative hours. Muscle soreness was the most frequently reported reason for poor FDP adherence (36.2%), followed by prolonged positioning requirements (22.6%) and difficulty adapting to the prescribed posture (17.1%). FDP adherence differed significantly across time periods, reaching its lowest level during the early morning hours (43.7%) and its highest levels during the afternoon and evening. Analysis by postoperative interval demonstrated a progressive decline in adherence from 68.8% during the first 6 hours to 46.4% at 18–24 hours after surgery. Shoulder, neck, and back pain persisted throughout the observation period without significant temporal variation ( <italic>P</italic> > 0.05). In contrast, arm pain ( <italic>P</italic> = 0.046) and chest pain ( <italic>P</italic> < 0.001) showed significant time-dependent changes, both peaking at 12–18 hours postoperatively. Conclusion Posture-related musculoskeletal pain is highly prevalent during the first 24 hours following PPV with intraocular tamponade and represents an important barrier to FDP adherence. The period 12–18 hours after surgery appears to be particularly vulnerable to chest and upper-limb pain, whereas adherence is poorest during the early morning and after the first 12 postoperative hours. These findings highlight the need for targeted, time-specific nursing strategies, including structured exercise programs, massage interventions, and enhanced overnight monitoring, to improve pain management, promote adherence to postoperative positioning, and potentially optimize surgical outcomes. </p>