Supraacetabular External Fixation for Pelvic Ring Fractures

Abstract

Objective: Closed reduction and maintenance of pelvic ring injuries by external stabilization. Indications: Emergency management of unstable type B and type C pelvic ring fractures. Definitive treatment of type B injuries. Definitive treatment of the anterior pelvic ring in type C injuries with transpubic instability after posterior internal stabilization. Adjunct stabilization of internal fixation. Stabilization of pelvic ring fractures in children. Contraindications: Poor general condition.Local soft-tissue damage. Local infection. Surgical Technique: Bilateral percutaneous insertion of Schanz screws into the supraacetabular area of iliac bone. Closed reduction and stabilization of the pelvic ring by compression and application of a connecting rod under image intensification. Postoperative Management: Depending on the patient's condition and the degree of pelvic instability, a change to an open procedure may become necessary. Mobilization of the patient with partial weight bearing (one fifth of body weight) on the side of the injured posterior pelvic ring using forearm crutches, irrespective of the degree of stability of the pelvis. Results: Retrospective analysis of 64 supraacetabular external fixator applications to stabilize the anterior pelvic ring in 20 type B and 44 type C injuries. Iatrogenic lesions of the lateral femoral cutaneous nerve: 4.5%; all sensory disturbances completely reversed within 1 year. No pin site infection. In two patients (3%) primary perforation of the Schanz screw into the small pelvis not necessitating any treatment.No secondary displacements of the anterior or posterior pelvic ring in type B injuries nor for type C injuries, sacral fractures associated with fractures of the pubic ramus. One pseudarthrosis of the pubic and ischial rami requiring surgical treatment.

Complications of Anterior Subcutaneous Internal Fixation for Unstable Pelvis Fractures: A Multicenter Study

“…It is possible to injure the nerve during implantation and removal requiring awareness of this complication. Prior studies using supraacetabular pins [2,5,6] have reported injury to the lateral femoral cutaneous nerve in zero of 37 [16], one of 14 (7%) [2], and three of 45 (7%) [4] patients, which is much lower. These studies listed injured nerves and we listed irritation and permanent injury.…”

“…We believe we could have avoided all three cases because they were attributed to technical error, were subsequently repaired, and led to good outcomes even in the patient with anterior and posterior failure who also had an infection. Loss of reduction has been reported in 7.5% to 60% of cases [7,11,19,21] with anterior fixation as the definitive treatment of the pelvic injury before 2000 but with modern fixation techniques and supplemental posterior fixation, it has fallen to 0% to 6% [4,13,16,17]. Three patients had the screw heads sunk too low resulting in the rod compressing the pelvic muscle and fascia.…”

“…Several groups report its use for treating vertically stable AP compression injuries [2,8] and lateral compression pelvic fractures [2,17]. The complications associated with external pelvic frames include pin tract infection in 2.5% to 50% of patients [1, 2, 4, 11-17, 19, 21], osteomyelitis in 0% to 7% [1,2,11,13,16,19], aseptic loosening in 0% to 19% [11,13,16,17,19], and loss of reduction in 0% to 33% [2,4,11] of rotationally unstable injuries treated with a standalone anterior external fixator. Loss of reduction in vertically unstable pelvic injuries treated with an isolated anterior external fixator is reported as high as 95% [11,12,18] and as low as 0% to 8% when combined with posterior fixation [4,13,16].…”

“…The complications associated with external pelvic frames include pin tract infection in 2.5% to 50% of patients [1, 2, 4, 11-17, 19, 21], osteomyelitis in 0% to 7% [1,2,11,13,16,19], aseptic loosening in 0% to 19% [11,13,16,17,19], and loss of reduction in 0% to 33% [2,4,11] of rotationally unstable injuries treated with a standalone anterior external fixator. Loss of reduction in vertically unstable pelvic injuries treated with an isolated anterior external fixator is reported as high as 95% [11,12,18] and as low as 0% to 8% when combined with posterior fixation [4,13,16]. Compression of the skin and subcutaneous tissues against the fixator frame has been documented in up to 8% [13] and nerve damage in 0% to 7% [2,4,11,16] of these patients.…”

“…Loss of reduction in vertically unstable pelvic injuries treated with an isolated anterior external fixator is reported as high as 95% [11,12,18] and as low as 0% to 8% when combined with posterior fixation [4,13,16]. Compression of the skin and subcutaneous tissues against the fixator frame has been documented in up to 8% [13] and nerve damage in 0% to 7% [2,4,11,16] of these patients. An anterior pelvic external fixator limits patient mobility, especially when sitting and when being rolled from side to side.…”