Microscope-Assisted Excision of CT-Occult Inferior Rectus Adhesions After Pediatric Orbital Floor Trapdoor Fracture Repair: A Case Report.

We report the case of a 12-year-old competitive athlete who presented with persistent ocular motility restriction and diplopia following surgical repair of an orbital floor trapdoor fracture. Although the initial surgery was performed at another institution on the day following the injury and postoperative CT confirmed the successful release of tissue entrapment, her clinical symptoms persisted (elevation restriction grade -3). Revision orbital surgery was performed 53 days after the initial injury. Pre-incision forced duction testing (FDT) confirmed mechanical tethering. Under microscopic guidance, meticulous adhesiolysis and scar excision were conducted to completely remove dense fibrotic-appearing adhesions on the orbital floor and the inferior surface of the inferior rectus muscle. Intraoperative FDT immediately converted to negative. Six months postoperatively, ocular motility completely resolved to grade 0, and the threshold for diplopia on the binocular single vision field improved substantially from 25° to 40°, allowing her to return to competitive sports without functional impairment. The meticulous observation and excision of these CT-occult scar-like adhesions using an operating microscope contributed significantly to the successful functional recovery. This case demonstrates that microscopic scar excision can be an effective intervention for persistent motility restriction after trapdoor fracture repair, even when residual entrapment has been resolved on CT.