Session III - Combined Meeting with AAST

Confirmation of the Safety and Accuracy of Physical Examination in the Evaluation of Knee Dislocation for Popliteal Artery Injury: A Prospective Study

F.E. Miranda, MD; J.W. Dennis, MD; H.C. Veldenz, MD; P.S. Dovgan, MD; E.R. Frykberg, MD; University of Florida Health Science Center, Jacksonville, FL

Background: Knee dislocation (KD) poses a significant risk for popliteal artery injury, which has prompted many surgeons to routinely evaluate these patients with arteriography (AG). We hypothesized that physical examination (PX) alone (no AG) accurately confirms or excludes surgically significant vascular injuries associated with KD.

Methods: All patients diagnosed with a KD by an attending orthopaedic surgeon between January 1990 and January 2000 were prospectively managed by protocol at our Level I trauma center according to the results of their PX. Those with hard signs (active hemorrhage, expanding hematoma, pulse deficit, distal ischemia, bruit/thrill) underwent AG followed by surgical repair if indicated. Patients with no hard signs (negative PX) were admitted for 23 hours, underwent serial PX, then followed as outpatients.

Results: There were 35 KD (18 right, 17 left) in 35 patients during this 10-year period. Two patients died from closed head injuries and multi-system trauma. Eight patients had hard signs (positive PX) at presentation (6) or after reduction of their dislocation (2). All 8 patients demonstrated a loss of pulses only. Six of these patients showed popliteal artery occlusion on AG and underwent surgical repair (5 vein grafts, 1 primary), 1 demonstrated popliteal spasm only and 1was normal. None of the 27 patients with negative PX developed limb ischemia or needed vascular surgery during hospitalization. Sixteen patients were available for follow-up (46%). Twelve patients (44%) with negative PX (mean 13 mo, range 2-35 months) and 4 patients with positive PX (50%) and surgical repair were contacted (mean 19 months, range 6-49 months). None of the patients in either group developed any vascular related symptoms or suffered from a vascular repair complication over the follow-up interval.

Conclusion: PX safely and reliably predicts the presence or absence of a popliteal artery injury following KD, with a 94.3% positive predictive value and 100% negative predictive value. AG is unnecessary when PX is negative, an approach which substantially reduces cost and resource utilization without adverse impact on the patient.