LATERAL COMPRESSION TYPE I INJURIES OF THE PELVIC RING: ARE THEY MECHANICALLY STABLE?

Abstract

We investigated whether lateral compression type I injuries of the pelvic ring are inheritably mechanically stable. Between January 2005 to January 2007 all consecutive admissions of a tertiary referral center for pelvic ring reconstruction with a LC I injury pattern were eligible for inclusion. Exclusion criteria were other patterns of pelvic ring injuries.

All patients underwent radiological assessment including AP pelvis, inlet/outlet views and CT. Patient demographics, mechanism of injury, other associated injuries, ISS, length of hospitalisation, type of operation, mode of mobilization, preoperative and postoperative visual analogue score pain VAS and follow up until fracture union were prospectively documented. Mechanical stability of the pelvic ring was assessed in the operating theatre under general anaesthesia. Instability was defined as displacement > 2 cm of the anterior or posterior elements. The minimum follow up was 12 months.

Of 210 patients admitted with pelvic fractures, 40 fulfilled the inclusion criteria (LC1 type). There were 23 female 17 male and with a mean age of 33.5 (range 18–68). The mean ISS was 10 (range 9–19). 23 patients (group 1) were found to have more than 2 cm rotational displacement during EUA and were stabilised with SI screws posteriorly and a combination of retro-pubic screws, external fixator or plating anteriorly. 17 patients (group 2) exhibited minimal displacement less than 5mm and were not stabilised. Rotational instability > 2cm was characterised by complete fracture of the sacrum posteriorly. Stabilisation of the pelvic ring in group I was associated with a significant reduction of the VAS within 72 hours from surgery, early ambulation and discharge from the hospital.

This study supports the view that not all LCI fracture patterns are mechanically stable. Examination under anaesthesia of the pelvic ring can assist the clinician in the decision making progress.