Comparison of free fibular flaps with reamer-irrigator-aspirator bone grafts for the reconstruction of critical-sized mandibular defects.

OBJECTIVE: Vascularized bone flaps are currently indicated for reconstructing mandibular defects 6 cm or larger. This technique can result in donor-site morbidity and requires microsurgery. To explore alternative methods of mandibular reconstruction, we sought to compare bone graft obtained with the reamer-irrigator-aspirator (RIA) device with the free fibula (FF) flap for the reconstruction of a critical-sized mandibular defect. METHODS: Sixteen 3-month-old Yorkshire pigs underwent 6-cm full-thickness resection of the left mandible. For the FF group (n = 8), an osseous FF flap was raised from the left leg and placed into the defect. For the RIA group (n = 8), a RIA Instrument Set was used on the ipsilateral femur to ream the femoral canal and harvest RIA putty. This putty containing medullary bone marrow contents and cortical bone was packed into the defect. At the study end point, volumetric, biomechanical, and histologic analyses were performed. RESULTS: Operative times were significantly shorter in the RIA group (RIA,126 [30] min; FF, 346 [50] min; P < 0.05). Biomechanical testing of reconstructed sites showed no significant difference in maximum fracture loads between both groups (RIA, 468 [97] N; FF, 689 [262] N; P = 0.11). Mean (SD) volume ratio of bone growth at the reconstructed sites was comparable between both groups (RIA, 71% [4.5%]; FF, 72% [3.3%]; P = 0.60). Equal bone quality was confirmed histologically. CONCLUSIONS: The RIA technique significantly reduces operative time and provides bone of equal strength and histologic quality to FF flap reconstruction in a large animal model. The RIA method may represent an efficient technique for the reconstruction of craniomaxillofacial defects.

Analysis of radiographically confirmed blunt-mechanism facial fractures.

Facial fractures resulting from blunt-mechanism trauma, although common, have been infrequently evaluated in large studies that do not include confirmation of fractures based on author review of available patient radiographic studies. An 8-year review (1998-2006) of the R Adams Cowley Shock Trauma Registry was performed with institutional review board approval. Patients diagnosed with blunt-mechanism facial fractures were identified by the International Classification of Diseases, Ninth Revision (ICD-9) codes and their facial fractures confirmed by author review of computed tomographic scans. Individual fractures were classified and grouped according to the facial thirds. Intra- and interreader variability was calculated, and confirmed fracture patterns were compared to fracture patterns listed by ICD-9 codes. Concomitant injuries and demographic data were additionally evaluated. Four thousand three hundred ninety-eight patients with 8127 fractures were identified. Intra- and interreader variability was 2% and 7%, respectively. ICD-9 coding misdiagnosed 12.5% of all fractures. Eighty-two percent of patients sustained associated injuries, including basilar skull fractures (7.6%) and cervical spine fractures (6.6%). 1.1% had at least one fracture in each facial third (panfacial fracture pattern). Significant relationships were found between demographic parameters, concomitant injuries, specific fractures, and fracture patterns. Studies investigating facial fractures should report fracture patterns confirmed by author review of available radiographic imaging. Large retrospective data sets containing confirmed fractures and capable of addressing rare fracture patterns can be compiled with low inter- and intrauser variability, and are useful for generating mechanistic hypotheses suitable for evaluation in prospective series or by directed biomechanical studies.

Tunneled superficial inferior epigastric artery (SIEA) myocutaneous/vascularized femur chimeric flaps: a model to study the role of vascularized bone marrow in composite allografts.

The role of vascularized bone marrow in promoting composite allograft survival can be assessed by intrinsically chimeric flaps. In this study, we introduce a significant modification to a previously described rat model of combined superficial inferior epigastric artery (SIEA) myocutaneous/vascularized femur transplantation. We previously noted autocannibalization in orthotopic myocutaneous SIEA allotransplants, which complicated clinical and histologic evaluation of rejection. We therefore designed syngeneic experiments in eight Lewis (RTl(1) ) rat pairs to explore the feasibility of tunneling the SIEA component of chimeric SIEA myocutaneous/vascularized femur flaps to the recipient dorsum. Vascularized SIEA myocutaneous/femur transplants survived in their entirety to POD 63 study endpoint with patent anastomoses in seven of eight (87.5%) transplants as confirmed clinically, histologically, and via near-infrared fluorescent angiography. Tunneling of the SIEA component of SIEA myocutaneous/vascularized femur flaps to the recipient dorsum can be achieved with high success rate and acceptable operative times, and is a technically easy method to study the role of vascularized bone marrow in composite allografts. This modification facilitates SIEA component monitoring, removes it from constant contact with cage bedding, and places it in a location where autocannibalization is unlikely.

Facial Fracture Patterns Associated with Traumatic Optic Neuropathy.

Traumatic optic neuropathy (TON) is rare. The heterogeneity of injury patterns and patient condition on presentation makes diagnosis difficult. Fracture patterns associated with TON have never been evaluated. Retrospective review of 42 patients diagnosed with TON at the R. Adams Cowley Shock Trauma Center from May 1998 to August 2010 was performed. Thirty-three patients met criteria for study inclusion of fracture patterns. Additional variables measured included patient demographics and mechanism. Cluster analysis was used to form homogenous groups of patients based on different fracture patterns. Fracture frequency was analyzed by group and study population. Visual depiction of fracture patterns was created for each group. Cluster analysis of fracture patterns yielded five common "groups" or fracture patterns among the study population. Group 1 ( n = 3, 9%) revealed contralateral lateral orbital wall (100%), zygoma (67%), and nasal bone (67%) fractures. Group 2 ( n = 7, 21%) demonstrated fractures of the frontal bone (86%), nasal bones (71%), and ipsilateral orbital roof (57%). Group 3 ( n = 14, 43%) involved fractures of the ipsilateral zygoma (100%), lateral orbital wall (29%), as well as frontal and nasal bones (21% each). Group 4 ( n = 5, 15%) consisted of mid- and upper-face fractures; 100% fractured the ipsilateral orbital floor, medial and lateral walls, maxilla, and zygoma; 80% fractured the orbital roof and bilateral zygoma. Group 5 ( n = 4, 12%) was characterized by fractures of the ipsilateral orbital floor, medial and lateral orbital walls (75% each), and orbital roof (50%). A notably high 15 of 33 patients (45%) sustained penetrating trauma. Our study demonstrates five fracture pattern groups associated with TON. Zygomatic, frontal, nasal, and orbital fractures were the most common. Fractures with a combination of frontal, nasal, and orbital fractures are particularly concerning and warrant close attention to the eye.

Facial fractures with concomitant open globe injury: mechanisms and fracture patterns associated with blindness.

BACKGROUND: Treatment of facial fractures in the setting of open-globe injuries poses a management dilemma because of the often disparate treatment priorities of multidisciplinary trauma teams and the lack of prognostic data regarding visual outcomes. METHODS: Patients in the University of Maryland Shock Trauma Registry sustaining facial fractures with concomitant open-globe injuries from January of 1998 to August of 2010 were identified. Odds ratios were calculated to identify demographic and clinical variables associated with blindness, and multivariate regression analysis was performed. RESULTS: A total of 99 patients were identified with 105 open-globe injuries. Seventy-nine percent of injuries were blinding, whereas 4.8 percent of globes achieved a final visual acuity greater than or equal to 20/400. Blindness was associated with penetrating injury, increasing number of facial fractures, zygomaticomaxillary complex fracture, admission Glasgow Coma Scale score less than or equal to 8, and globe injury spanning all three eye zones. Fracture repair was performed more frequently (62.5 percent) and more quickly (average time to fracture repair, 4.5 days) in cases of primary globe enucleation/evisceration when compared with complete (21.2 percent; 8 days; p=0.35) or incomplete (42.9 percent; 11 days; p=0.058) primary globe repair. CONCLUSIONS: Penetrating injury mechanism and zone of eye injury appear to be better indicators of visual prognosis than facial fracture patterns. Given the high rates of blindness, secondary enucleation, and delay of fracture repair in patients that were not primarily enucleated, the authors recommend that orbital fracture repair not be delayed in the hopes of eventual visual recovery in cases of high-velocity projectile trauma. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Ocular injury, visual impairment, and blindness associated with facial fractures: a systematic literature review.

BACKGROUND: Injuries to the face can potentially lead to destruction of vital structures, with devastating sequelae to the patient. Facial fractures, especially of the midface, are often complicated by ocular injuries. The purpose of this study was to systematically review the literature to better understand specific fracture patterns associated with ocular injuries, including visual impairment and blindness. METHODS: The PubMed, EMBASE, and Cochrane databases from January of 2004 to April of 2010 were systematically reviewed to identify relevant studies. Only those that investigated facial fractures with concomitant ocular injuries, visual impairment, and/or blindness were included. Studies that described nonfacial fractures or those that only focused on the function of extraocular muscles were excluded. Case reports, nonsystematic reviews, and studies with fewer than 10 patients were also excluded. RESULTS: Eleven articles met study criteria and were included for analysis. There were a total of 14,535 patients, with an average of 1211 patients (range, 39 to 4426) per study. Level of evidence included levels II (n = 1 study), III (n = 1), and IV (n = 9). The mean reported rate of acute visual loss was 1.7 percent. Periorbital and orbital blowout fractures were more often complicated by ocular injuries compared with other facial fracture patterns. High-impact zygomatic fractures were most commonly associated with blindness. CONCLUSIONS: Existing studies exploring ocular injuries, visual impairment, and blindness associated with facial fractures offer conflicting data. Specifically directed studies are required so that significant correlations between specific fracture patterns and specific ocular injuries can be drawn. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

Isolated bilateral zygomatic arch fractures of the facial skeleton are associated with skull base fractures.

BACKGROUND: To date, only limited case reports involving isolated bilateral zygomatic arch fractures exist. This fracture pattern is defined by the presence of bilateral zygomatic arch fractures and the absence of any other facial fractures. The purpose of this study was to systematically review a large trauma database to determine whether this fracture pattern exists and, if so, to elucidate the mechanism of injury and associated concomitant injuries. METHODS: A retrospective review of all patients admitted to the R Adams Cowley Shock Trauma center from February of 1998 to December of 2009 was conducted. International Classification of Diseases, Ninth Revision coding of computed tomographic scans was used to identify patients with zygoma fractures. The facial computed tomographic scans of all patients coded with bilateral zygoma fractures were reviewed to determine whether any had isolated bilateral zygomatic arch fractures. Medical charts were reviewed extensively. RESULTS: Five patients (0.24 percent of all zygoma fractures, 3.18 percent of bilateral zygoma fractures) were found to have isolated bilateral zygomatic arch fractures. All five patients had evidence of skull impact with at least one skull fracture and one skull base fracture. Glasgow Coma Scale scores (range, 6 to 14; average, 8.2) were significantly lower (t test, two-sided, p=0.01) compared with all patients (average, 12.2) with facial trauma during the study period. CONCLUSIONS: Isolated bilateral zygomatic arch fractures do exist. The authors' findings suggest skull impacts as the inciting mechanism of injury and an intimate link with skull base force transmission. The severe nature of this injury warrants a search for concomitant injuries to the head, brain, and spinal cord.