Purpose: To compare the accuracy of post-operative plain radiographs versus computed tomography (CT) scans for the assessment of acetabular fracture reduction.

Method: A retrospective assessment of sixty-four fractures in sixty-two patients was performed independently by three orthopedic trauma surgeons. Pre-operative CT scans and three plain radiographs (one anteroposterior pelvis and two Judet views) were used to classify the fracture pattern and measure pre-operative articular step and gap. Post-operative reduction quality was assessed using three plain radiographs and an axial CT assessing for step, gap, intra-articular hardware or fragments and necessity to re-operate.

Results: Fracture patterns were as follows; posterior wall (n=10), posterior column (n=1), anterior wall (n=4), anterior column (n=1), transverse (n=12), posterior column posterior wall (n=4), transverse posterior wall (n=8), T-type (n=6), anterior column posterior hemi-transverse (n=5) and associated both column (n=11). Pre-operatively, the average step and gap on plain radiographs was 8.7 mm (±SD) and 15.3 mm (±SD). Post-operatively, the average step and gap was 0.6 mm (SD) and 0.9 mm (SD) based on 46 patients. The assessment was not possible in 18 patients due to overlying hardware. Using plain radiographs, one patient was found to have an inadequate reduction (> 2mm step and/or > 3mm gap). Post-operative measurement of step and gap by CT scan were 1.2 mm (SD) and 2.3 mm (SD) respectively. Using CT scans, eight patients were found to have either an inadequate reduction, intra-articular hardware or retained fragments. Computed tomography demonstrated 2 times more step and gap compared to plain radiographs.

Conclusion: Post-operative CT was found to be more sensitive than plain radiographs to assess the quality of acetabular fracture reduction. Plain radiographs detected only 1 out of 8 cases where further operative intervention may have been beneficial. Given the consequences of missing an unacceptable reduction, intra-articular hardware, or retained intra-articular fragments, it is recommended that all fractures should be assessed postoperatively with CT unless the patient is not a candidate for further surgery for reasons independent of reduction quality. The benefits of post-operative CT imaging in acetabular fractures likely outweigh the cost and radiation exposure associated with its use.

Systemic capillary leak syndrome, or the Clarkson syndrome, is an extremely rare condition in which increased capillary permeability results in a massive shift of fluid into the extravascular space. This is followed rapidly by hypotensive shock, haemoconcentration, and, potentially, substantial oedema of the limbs resulting in an acute compartment syndrome. It is important for orthopaedic surgeons to be aware of this syndrome as our medical colleagues, who initially care for these patients, are less familiar with the diagnosis and the need for emergency management of the associated compartment syndrome should it develop. There have been fewer than 100 cases of this entity reported.

This case report is the first to describe the subsequent development of a compartment syndrome in all four limbs. Clinical vigilance and continuous monitoring of intracompartmental pressure is necessary in these patients in order to help reduce limb-threatening complications.