Nonunions and malunions after pelvic fractures: why they occur and what can be done?

Between 1987 and 2005, 55 patients were treated operatively to correct 44 malunions and 11 nonunion of the pelvic ring. These pathologies were the consequence of a nonoperative initial treatment for 38 cases, or of an inappropriate indication, such as the use of an external fixator as the definitive treatment of an unstable pelvic fracture in 15 and symphysis cerclage wiring in 2. Three patients had undergone ORIF of the lumbar spine performed by neurosurgeons, but the pelvic fractures below were ignored. On the basis of damaging mechanisms and of the main instability plane, initial lesions were classified as follows: 32 shearing lesions, 11 rotatory by antero-posterior compression, 7 by lateral compression, 5 mixed. In 23 cases the site of the posterior lesion was the sacrum, 4 of which were H fractures type; 13 were sacroiliac joint dislocations, or rotatory instability of the joint (in 2 cases the lesion was bilateral), 8 were sacroiliac dislocation fractures (crescent fractures); 7 were fractures of the iliac wing. Four patients only had pubic symphysis diastasis. Indications for surgery were pain associated with deformity or instability. Surgery was performed through a multistage procedure. Mean surgery time was 6h (range: 2-10h), with a mean blood loss of 700ml (range: 200-5000ml). Follow-up ranged from a minimum of 16 months to a maximum of 14 years (mean: 5.85 years).

At the last follow-up, all patients but one had consolidated and were considered stable. All patients had improved walking ability. Six patients still report pain. Even if most of the deformity were corrected with a significant decrease of pre-operative symptoms achieved, deformity correction was considered satisfactory but not anatomic, in 12 patients (21%). Complications occurred in 24% of patients but most were temporary.

The most frequent cause of pelvic malunion or nonunion was inadequate treatment. To reduce the number and the percentage of disabilities, it is necessary that specialised centres provide patients with early treatment that is adequate and definitive.