The anterior pelvic internal fixator is increasingly used for
the treatment of unstable, or displaced, injuries of the anterior
pelvic ring. The evidence for its use, however, is limited. The
aim of this paper is to describe the indications for its use, how
it is applied and its complications. We reviewed the case notes and radiographs of 50 patients treated
with an anterior pelvic internal fixator between April 2010 and
December 2015 at a major trauma centre in the United Kingdom. The
median follow-up time was 38 months (interquartile range 24 to 51).Aims
Patients and Methods
Traditionally, unstable anterior pelvic ring injuries have been stabilised with an external fixator or by internal fixation. Recently, a new percutaneous technique of placement of bilateral supraacetabular polyaxial screws and subcutaneous connecting bar to assemble an “internal fixator” has been described. We present the surgical technique and early clinical results of using this technique in twenty-five consecutive patients with a rotationally unstable pelvic ring injury and no diastasis of the symphysis pubis treated between April 2010 and December 2013. Additional posterior pelvic stabilisation with percutaneous iliosacral screws was used in 23 of these patients. The anterior device was routinely removed after three months. Radiological evidence of union of the anterior pelvic ring was seen in 24 of 25 patients at a minimum 6 month follow-up. Thirteen patients developed sensory deficits in the lateral femoral cutaneous nerve (five bilateral) and only one fully recovered. The anterior pelvic internal fixator is a reliable, safe and easy percutaneous technique for the treatment of anterior pelvic ring injuries, facilitating the reduction and stabilisation of rotational displacement. However, lateral femoral cutaneous nerve dysfunction is common. The technique is recommended in cases with bilateral or unilateral pubic rami fractures and no diastasis of the symphysis pubis.
Magnetic resonance imaging (MRI) scans are widely used in the assessment of knees, often prior to arthroscopic procedures. The reporting of chondral damage on MRI scans can be variable. The correlation between MRI reports of chondral damage and that found at arthroscopy is often inconsistent. The aim of this study was to identify how well MRI reports correlated with the extent of chondral damage found at arthroscopy. A retrospective case-note review of a single-surgeon series of 175 arthroscopic procedures was performed. 83 patients were included in the study. The remainder were excluded if an MRI scan had not been performed, or had been performed more than 3 months prior to surgery. The condition of the articular cartilage demonstrated by MRI was compared to that found at arthroscopy. Data was analysed for presence and extent of chondral damage. Comparison between MRI and arthroscopy findings showed high Specificity (90%) and Negative Predictive Values (89%) for chondral damage, but low Sensitivity (46%). Cohen's kappa values < 0.2 revealed very poor correlation for the extent of damage. This study demonstrates that MRI is good at describing whether articular damage is present but does not reliably describe the extent of the damage.
