Linear nondisplaced orbital fractures with muscle entrapment.

PURPOSE: Linear nondisplaced orbital floor fractures with muscle entrapment occur in the pediatric population. These fractures occur with minimal trauma and few external signs of injury. This study reviews the clinical findings, radiologic findings and interpretations, preoperative and postoperative ocular motility, and outcomes in this subset of orbital fracture patients treated with early surgical repair.

METHODS: Review of 12 children with linear orbital floor fractures with inferior rectus muscle entrapment, who underwent surgical repair by a single surgeon.

RESULTS: All affected eyes demonstrated significant limitation to elevation and, in seven, depression preoperatively. All 12 patients were operated within 4 days of injury. Radiologist interpretation of computed tomographic (CT) findings recognized fracture in 9 of 11 cases in which a dictated report was available. The radiology report correctly identified muscle entrapment in only three cases and was equivocal in three other cases. The ophthalmologist, based on clinical examination and observation of the CT images, correctly identified findings consistent with linear orbital fracture with muscle entrapment in every case. Surgical findings included a nondisplaced linear floor fracture with muscle entrapment. In the early postoperative period limited elevation was present in 10 patients and limited depression was present in 7. Duction deficits and diplopia resolved in 4 days to 5 months.

CONCLUSIONS: Despite prompt surgical repair, limited elevation and depression occur in the early postoperative period, possibly due to muscle edema, hemorrhage, and ischemia. Recovery of normal ocular motility may take weeks or months. External signs of injury may be minimal and radiologic interpretation may not recognize fracture or muscle entrapment.