Session IX - Tibia

Acute Compartment Syndrome - Who Is At Risk?

P. Gaston, MBChB, FRCS Ed; Margaret M. McQueen, MD, FRCS Ed (Orth); Charles M. Court-Brown, MD, FRCS Ed (Orth); Royal Infirmary of Edinburgh, Edinburgh, Scotland

Introduction: Acute compartment syndrome is a potentially devastating complication of injury. Recent literature has shown that diagnosis can be made earlier and complications are minimized with the use of continuous compartment pressure monitoring. In situations where compartment pressure monitoring equipment is a limited resource or where clinical symptoms and signs only are used to make the diagnosis, knowledge of which patients are at risk would allow improved targeting of resources. This is an epidemiological study designed to identify those patients at risk of developing acute compartment syndrome after injury.

Methods: One hundred and sixty-four cases of acute compartment syndrome complicating injury were prospectively documented over an eight year period from 1988 to 1995 inclusive. Demographic data was recorded on all patients.

Results: The commonest condition was tibial diaphyseal fracture, which was 35% of the total cases. Soft tissue injury not in association with fracture made up 22% of the cases, and the crush syndrome and distal radial fractures were 10% respectively. Forearm fractures accounted for 8.5% of the patients. Other conditions were all less than 5% of the total.

Of the overall population there were 149 males and 15 females with a mean age of 32 years (range 14-88 years). The mean age for the men was 30 years and the mean age for females 44 years.

There were 58 cases of tibial diaphyseal fracture complicated by acute compartment syndrome with 1,349 tibial diaphyseal fractures in the same eight-year period. This gave an incidence of 4% in all tibial diaphyseal fractures. In the under 35-year-old-age group however, the incidence of acute compartment syndrome was 6% compared to 2% in the over 35 year old age group. This difference was statistically significant (p<0.01). There was a preponderance of men with 54 of the 58 patients being male, which is significantly higher than the normal population of tibial diaphyseal fractures. The mode of injury in those complicated by acute compartment syndrome was similar to that of the total population of tibial diaphyseal fractures. Thus, young men are at significant risk of acute compartment syndrome regardless of whether the injury is high-energy or low-energy in nature.

Thirty-six patients developed acute compartment syndrome in association with soft tissue injury. Thirty-one were men and 5 were women with an average age of 37 years. Their age/sex distribution did not conform to a pattern. The majority of patients had sustained a direct blow to the muscle compartment, although 15% of the patients had a spontaneous onset associated with anti-coagulants or a bleeding diathesis. Patients without fracture are at significant risk of acute compartment syndrome if they have a bleeding diathesis.

There were 16 cases of distal radial fracture associated with acute compartment syndrome, 15 of whom were male and 1 female. The mean age was 26 years. This is a complete reversal of the demographic pattern of the total population of distal radial fractures in the same period in which the vast majority are female and the mean age is 59 years. The incidence of acute compartment syndrome in the under 35-year-old-age group with distal radial fracture was 1.5% compared to 0.07% in the age group over 35 years. This is a highly significant difference. Thirty-eight percent (38%) of the distal radial fractures complicated by acute compartment syndrome were sustained in a road traffic accident and 31% in sports. Only 13% had been sustained in a fall from standing height compared to 86% of the total population. Thus the young male, especially with a high-energy injury, is at significant risk of acute compartment syndrome following distal radial fracture.

There were 14 cases of forearm diaphyseal fracture complicated by acute compartment syndrome. All of these were males with a mean age of 34 years. Twelve of the 14 sustained high-energy injury and 8 of the 14 sustained multiple injuries. Five of the 14 patients were unconscious at the time of diagnosis. Young men with high-energy forearm diaphyseal fractures are at significant risk of acute compartment syndrome.

Discussion and Conclusion: Although compartment pressure monitoring allows earlier diagnosis of acute compartment syndrome than clinical symptoms and signs, monitoring equipment may be a limited or absent resource in some centres. Information allowing the clinician to identify at- risk groups for acute compartment syndrome will allow more effective use of limited resources. Knowledge of the at-risk groups will also increase awareness of potential acute compartment syndrome where the diagnosis relies on clinical symptoms and signs. At-risk groups for acute compartment syndrome are the young male tibial diaphyseal fracture, the young male distal radial fracture with high-energy injury, soft tissue injuries with bleeding diatheses and the young male forearm diaphyseal fracture sustained with high-energy injury.