The role of post-operative radiation in the prevention of heterotopic ossification in patients with post-traumatic acetabular fracture.

Heterotopic ossification (HO) with subsequent pain and limitation of motion of the lower extremity is a common and significant problem for patients who suffer traumatic acetabular fracture (TAF). The incidence of heterotopic ossification is markedly increased for patients requiring surgical repair depending on the degree of trauma and the type of surgical repair necessary. Radiation therapy (RT) has proven to be the most effective surgical adjunct for the prevention of heterotopic ossification in patients undergoing total hip replacement (THR), but has not been reported in patients with traumatic fracture and repair. This report details an experience with patients treated at a Shock Trauma Center with extensile repair and immediate (within 48 hr) post-operative radiation therapy given as 5 daily fractions of 2 Gy in 5 to 7 days to a total dose of 10 Gy using megavoltage radiation therapy. A total of 30 consecutive patients (RT group) have been treated at our institution since June 1985. The last 20 patients treated with surgery only (non-RT group) prior to initiation of this study were used as a control group. Heterotopic ossification was seen to some degree in 50% of all radiation therapy patients, but was severe in only three of 30 (10%) of cases [three (10%) had Brooker III HO and no patients had ankylosis (Brooker IV HO)]. In contrast, some degree of heterotopic ossification was seen in 90% of the non-radiation therapy patients, and was severe in 10 of 20 (50%) of patients [seven (35%) had Brooker III HO whereas three (15%) had ankylosis (Brooker IV)]. This difference is significant for both total incidence and incidence of severe cases (p less than 0.01). This reduction in heterotopic ossification incidence approaches the magnitude reported for high-risk patients with total hip replacement. Even though the incidence of severe heterotopic ossification after radiation therapy for total hip replacement is approximately 5% and for traumatic acetabular fracture patients it is double (10%), the actual incidence of heterotopic ossification without radiation therapy is different in the two conditions. For total hip replacement, the incidence is about 30% and for traumatic acetabular fracture it is 50%. Radiation therapy has again proven itself to be an excellent surgical adjunct to prevent heterotopic ossification, this time in traumatic acetabular fracture patients.

Pelvic fracture in multiple trauma: classification by mechanism is key to pattern of organ injury, resuscitative requirements, and outcome.

Three hundred forty-three multiple trauma patients with major pelvic ring disruption were studied and subdivided into four major groups by mechanism of injury: antero-posterior compression (APC), lateral compression (LC), vertical shear (VS), and combined mechanical injury (CMI). Acetabular fractures which did not disrupt the pelvic ring were excluded. The mode of injury was: MVA, 57.4%; motorcycle, 9.3%; fall, 9.3%; pedestrian, 17.8%; crush, 3.8%. The LC and APC groups were divided into Grades 1-3 of increasing severity. The pattern of organ injury: including brain, lung, liver, spleen, bowel, bladder, pelvic vascular injury (PVASI), retroperitoneal hematoma (RPH) and complications: circulatory shock, sepsis, ARDS, abnormal physiology, and 24-hr total fluid volume administration were all evaluated as a function of mortality (M). As LC grade increased from 1 to 3 there was increased % incidence of PVASI, RPH, shock, and 24-hr volume needs. However, the large incidence of brain, lung, and upper abdominal visceral injuries as causes of death in Grade 1 and 2 fell in LC3, with limitation of the LC3 injury pattern to the pelvis. As APC grade increased from 1 to 3 there was increased % injury to spleen, liver, bowel, PVASI with RPH, shock, sepsis, and ARDS, and large increases in volume needs, with important incidence of brain and lung injuries in all grades. Organ injury patterns and % M associated with vertical shear were similar to those with severe grades of APC, but CMI had an associated organ injury pattern similar to lower grades of APC and LC fractures. The pattern of injury in APC3 was correlated with the greatest 24-hour fluid requirements and with a rise in mortality as the APC grade rose. However, there were major differences in the causes of death in LC vs. APC injuries, with brain injury compounded by shock being significant contributors in LC. In contrast, in APC there were significant influences of shock, sepsis, and ARDS related to the massive torso forces delivered in APC, with large volume losses from visceral organs and pelvis of greater influence in APC, but brain injury was not a significant cause of death. These data indicate that the mechanical force type and severity of the pelvic fracture are the keys to the expected organ injury pattern, resuscitation needs, and mortality.

Preoperative angiographic assessment of the superior gluteal artery in acetabular fractures requiring extensile surgical exposures.

Extensile exposures used for complex acetabular fracture reconstructive surgery often create abductor muscle flaps pedicled on the superior gluteal artery. Preoperative arteriograms were performed in eight patients who required extended iliofemoral or modified extended iliofemoral surgical approaches to assess the integrity of the superior gluteal artery. All of the patients had complex acetabular fractures, with significant displacement of the fracture into the sciatic notch. Abnormalities of the superior gluteal artery were found in three patients. One patient demonstrated a complete laceration of the superior gluteal artery, one patient a complete arterial occlusion, and one patient had a compressive entrapment of the artery at the fracture site. Preoperative angiographic evaluation of the superior gluteal artery is suggested for patients with acetabular fractures that are displaced into the sciatic notch and who will require an extensile surgical exposure creating an abductor muscle flap supplied by the superior gluteal artery.