THE PRESENCE AND PATTERN OF VASCULAR INSUFFICIENCY IN THE OLDER PATIENT SUFFERING AN UNSTABLE ANKLE FRACTURE – THE RELATIONSHIP TO SKIN AND WOUND COMPLICATION

Abstract

Impaired vascularity of the skin in elderly ankle fracture patients causes the skin and wound complications. This is part of a RCT comparing ORIF and close contact casting (CCC) for isolated unstable ankle fractures in patients > 60 years. Assessments over 6-months

1. trans-cutaneous O2 saturation (TcP02) of medial and lateral ankle skin

2. Ankle-Brachial Pressure Index (ABPI).

3. 3-vessel arterial duplex scan

4. distal calf perforator artery patency.

The uninjured limb was the control.

Eighty-nine patients eligible; 59 participated (76% female). 30 randomised to ORIF; 29 to CCC. Each had one death and one withdrawal. Vascular data available on 55. Two patients had delays in wound healing (> 25% for > 6-weeks). Two further developed wound infections. No skin breakdowns in CCC group. There was a reduced TcP02 on day-3 in the injured limb. The TcP02 rose at 6-weeks compared to day-3 (medial 58mmHg; lateral 53mmHg, p=0.002) in the injured leg. At 6-months the TcP02 measurements were not different to uninjured leg. A critical TcP02 (< 20mmHg) found in 4, correlated with skin problems (p=0.003). Two of these had the only major delays in wound healing and one of the two wound infections.

94% of participants had normal ABPI’s (> 1.0). There was no difference between patients with or without an impaired ABPI (< 0.7 mm Hg) and wound problems (p=0.20).

There was no difference in patent perforators between the injured and uninjured (p=0.39).

Occult vascular insufficiency is present but at low incidence. ABPI and Duplex-US are insensitive for predicting infection or delayed healing. The ankle fracture injury does not disrupt the local perforators. TcPO2 is sensitive and specific for predicting skin problems. Impairment of skin oxygenation is transient. Current TcPO2 technology however is impractical as a clinical tool.