Management of the medial canthal tendon in nasoethmoid orbital fractures: the importance of the central fragment in classification and treatment

The medial canthal tendon and the fragment of bone on which it inserts ("central" fragment) are the critical factors in the diagnosis and treatment of nasoethmoid orbital fractures. The status of the tendon, the tendon-bearing bone segment, and the fracture pattern define a clinically useful classification system. Three patterns of fracture are appreciated: type I--single-segment central fragment; type II--comminuted central fragment with fractures remaining external to the medial canthal tendon insertion; and type III--comminuted central fragment with fractures extending into bone bearing the canthal insertion. Injuries are further classified as unilateral and bilateral and by their extension into other anatomic areas. The fracture pattern determines exposure and fixation. Inferior approaches alone are advised for unilateral single-segment injuries that are nondisplaced superiorly. Superior and inferior approaches are required for displaced unilateral single-segment injuries, for bilateral single-segment injuries, and for all comminuted fractures. Complete interfragment wiring of all segments is stabilized by junctional rigid fixation. All comminuted fractures require transnasal wiring of the bones of the medial orbital rim (medial canthal tendon-bearing or "central" bone fragment). If the fracture does not extend through the canthal insertion, the canthus should not be detached to accomplish the reduction.     

A new classification of palatal fracture and an algorithm to establish a treatment plan

Palatal fractures have previously been classified according to the anatomic location of the fracture line, which is helpful for understanding the types of palatal fracture, but which is insufficient for helping the surgeon to decide which fracture to open and how to do so. The purpose of this study was to aid in the establishment of a precise treatment plan by determining the surgical approach and the types of stabilization that should be used for different types of palatal fracture.In a retrospective review of 136 consecutive Le Fort maxillary fractures over 6 years, 18 patients (13.2 percent) with palatal fractures were analyzed. The principle of open reduction and internal fixation was applied to all the patients. In six patients (33 percent), exploration and fixation was done in the palatal surface. Eight patients (44 percent) needed an extended period of immobilization (4 to 6 weeks). No major complications were observed during the follow-up period.An algorithm was devised to help establish a proper treatment plan, and palatal fractures were classified into four types: closed reduction, anterior treatment, anterior and palatal treatment, and combined. The key elements considered in deciding the treatment principle and the classification of a palatal fracture were the possibility of closed reduction, surgical exposure, site of rigid fixation, and stability of fractured segments after rigid fixation. The outcome of reconstruction and the postoperative course differed depending on the type of palatal fracture. This classification scheme provided an easy and simple way to establish a treatment plan and was helpful in learning the treatment principles of palatal fracture.     

Prospective comparison of panoramic tomography (zonography) and helical computed tomography in the diagnosis and operative management of mandibular fractures

This prospective study compared the sensitivity of panoramic tomography (zonography) and helical computed tomography (CT) in diagnosing 73 mandibular fractures in 42 consecutive patients and correlated the results with known surgical findings. The purpose of the study was to determine the optimal radiologic examination for the diagnosis and operative management of mandibular fractures. The attending surgeons' interpretations of panoramic tomograms and helical CT images in the axial plane were compared with the patients' known surgical findings. A series of questions assessed the relative contribution of these two radiologic examinations in formulating an optimal operative plan for each patient. In the 42 patients studied, the sensitivity of helical CT was 100 percent in diagnosing mandibular fractures; this compared with 86 percent (36 of 42) for panoramic tomography, in which significantly more fractures were missed (p = 0.0412). In the six patients with fractures not visualized, the operative management was altered because of the new fracture visualized on helical CT. Of the seven missed fractures, six were in the posterior portion of the mandible. Comparing fracture detection by region, seven fractures found on helical CT were not visualized on panoramic tomography. Helical CT improved the understanding of the nature of mandibular fractures by providing additional information regarding fracture displacement and comminution and by locating injuries missed using panoramic tomography. This study suggests that helical CT alone may be more diagnostic than panoramic tomography alone in evaluating mandibular fractures. Helical CT sufficiently demonstrated details of fractures in 41 of 42 patients; in one patient, the nature of a dental root fracture was better delineated by panoramic tomography.     

Treatment of Mandibular Condyle Fractures Using a Modified Transparotid Approach via the Parotid Mini-Incision: Experience with 31 Cases

Surgery for mandibular condyle fractures must allow direct vision of the fracture, reduce surgical trauma and achieve reduction and fixation while avoiding facial nerve injury. This prospective study was conducted to introduce a new surgical approach for open reduction and internal fixation of mandibular condyle fractures using a modified transparotid approach via the parotid mini-incision, and surgical outcomes were evaluated. The modified transparotid approach via the parotid mini-incision was applied and rigid internal fixation using a small titanium plate was carried out for 36 mandibular condyle fractures in 31 cases. Postoperative follow-up of patients ranged from 3 to 26 months; in the first 3 months after surgery, outcomes for all patients were analyzed by evaluating the degree of mouth opening, occlusal relationship, facial nerve function and results of imaging studies. The occlusal relationships were excellent in all patients and none had symptoms of intraoperative ipsilateral facial nerve injury. The mean degree of mouth opening was 4.0 (maximum 4.8 cm, minimum 3.0 cm). No mandibular deviations were noted in any patient during mouth opening. CT showed complete anatomical reduction of the mandibular condyle fracture in all patients. The modified transparotid approach via the smaller, easily concealed parotid mini-incision is minimally invasive and achieves anatomical reduction and rigid internal fixation with a simplified procedure that directly exposes the fracture site. Study results showed that this procedure is safe and feasible for treating mandibular condyle fracture, and offers a short operative path, protection of the facial nerve and satisfactory aesthetic outcomes.     

Management of frontal sinus fractures

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Understand the radiographic and clinical diagnosis of frontal sinus fractures. 2. Identify various management approaches to the frontal sinus fracture and the indications for each. 3. Understand the rationale behind the decision of sinus obliteration when needed. 4. Recognize the most common complications arising from frontal sinus fracture treatment and the methods of avoiding or managing these complications. SUMMARY: Frontal sinus fracture management is still controversial and involves preserving function when feasible or obliterating the sinus and duct, depending on the fracture pattern. There is no single algorithm for the choice of management, but appropriate treatment depends on an accurate diagnosis using physical examination, computed tomography data, and the findings of intraoperative exploration. The amount and location of fixation and the need for frontonasal duct and sinus obliteration or elimination of the entire sinus depend on the anatomy of the fracture in general and the extent of involvement of the anterior wall of the sinus, the frontonasal duct, and the posterior wall in particular. This article discusses an algorithm for frontal sinus fractures that was obtained from the literature and modified according to the authors' experience. The decision-making process presented by the authors has withstood the test of time over a period of more than 20 years in their practice and has been proven to be safe and efficacious in treating frontal sinus fractures of all types.     

The fate of plates and screws after facial fracture reconstruction.

Rigid plate and screw fixation is the mainstay of treatment for complex fractures of the facial skeleton. Complications of plate and screw fixation include prominence, infection, exposure, and migration. Five hundred and seven patients undergoing plate and screw fixation for facial fractures (1112 fractures) from 1983 to 1988 were followed for complications. Sixty-one patients (12 percent) required hardware removal. The location on the facial skeleton influenced symptoms and the rate of hardware removal. Infection and exposure may be decreased with antiseptic irrigations, avoiding mucosal damage, attention to proper mucosal closure, and correct placement of plates. Prominence may be decreased by the use of microplates in the supraorbital, frontal, and naso-orbital-ethmoid locations.     

The management of orbitozygomatic fractures

Orbitozygomatic injuries are among the most common fractures encountered by the plastic surgeon. Appropriate management depends on an accurate diagnosis, focusing on the physical examination and data from computed tomography scans. One must pay particular attention to the orbital component of this injury, as it is from this that so much of the morbidity relating to these fractures is incurred. As with all facial fractures, accurate reduction is paramount to a successful outcome. As many buttresses as are necessary should be visualized to ensure an anatomic reduction. The amount and location of fixation depend on the fracture anatomy.A successful outcome may be expected if these basic principles are followed.     

Experimental and probabilistic analysis of distal femoral periprosthetic fracture: a comparison of locking plate and intramedullary nail fixation. Part A: experimental investigation

The following is a two-part study. Part A evaluates biomechanically intramedullary (IM) nails vs. locking plates for fixation of femoral fractures in osteoporotic bone. Part B of this study introduces a deterministic finite element model of each construct type and investigates the probability of periprosthetic fracture of the locking plate compared with the retrograde IM nail using Monte Carlo simulation. For Part A, an extra-articular, metaphyseal wedge fracture pattern was created in 11 osteoporotic fourth-generation composite femurs. Fixation was performed with a locking plate or a retrograde IM nail. Axial, torsion and bending cyclic loading to simulate post-operative damage accumulation were performed followed by ramped load to failure. Locking plates proved to be more stable (using stiffness as the determining factor) in osteoporotic bone as observed under low load cycle conditions. However, some of these advantages were offset by a greater incidence of sudden periprosthetic fracture observed under ramped loading conditions. Cadaveric, osteoporotic femurs included as a case study also exhibited periprosthetic fracture, but failure was accompanied by catastrophic comminution of the cortex. Periprosthetic failure at the implant end including bone comminution is difficult to salvage with revision fixation. The weakened trabecular matrix and thinned cortex of osteoporotic bone may increase the incidence of periprosthetic fracture. It is, therefore, essential for the surgeon to consider all possible loading scenarios when recommending an ideal implant for the osteoporotic patient.     

Internal fixation of malar fractures: an experimental biophysical study

Open reduction and internal fixation of displaced zygoma fractures are necessary to avoid immediate and delayed facial disfigurement. Interosseous wires, Kirschner wires, and more recently, rigid metallic miniplates have been recommended for fixation of these and other midfacial fractures. However, the precise physical stability of the zygoma with respect to wire versus miniplate fixation methods and with respect to the number and location of miniplates applied is not known. Noncomminuted zygoma fractures were simulated by saw osteotomy in eight fresh human cadaver heads (16 zygoma "fractures"). Each zygoma was sequentially fixated with three miniplates, two miniplates, one miniplate, and three interosseous wires across the orbital rim and arch "fractures". Static and oscillating loads simulating maximal physiologic masticatory stresses were applied to the fixated zygoma along the lines of action of the masseter muscle by means of a tensometer. The stability and adequacy of each pattern of fixation were recorded. Double-miniplate fixation across the orbital rim of simulated noncomminuted zygoma "fractures" is sufficient to withstand static and oscillating loading similar to physiologic masticatory forces. Neither single-miniplate fixation nor triple-wire fixation are sufficient to stabilize the zygoma against similar forces.     

Modified towel-clamp technique to effect reduction of displaced mandible fractures

We report a technique that uses a modified standard towel clamp, allowing a single surgeon to perform and maintain an anatomic reduction of displaced mandible fractures simultaneous with the application of internal fixation. The reduced convergent angle of the modified towel clamp allows bicortical engagement of the clamp, which prevents comminution of the fracture or the outer cortex of the mandible. Additionally, the modification allows the clamp to engage the bone with less exposure than conventional towel clamps. In our clinical experience of treating more than 100 mandible fractures a year, this technique proves superior to others described in the literature.     

Application of minimal-access techniques in lag screw fixation of fractures of the anterior mandible

A modification of the traditional open methods for the surgical management of anterior mandibular fractures using the principles of minimal-access surgery is presented; it was successfully performed in five patients. This technique incorporates the use of lag screws introduced through small incisions transmucosally or percutaneously after anatomic reduction of the fracture, and it relies on accurate preoperative radiologic assessment of the fracture pattern and location. This technique is indicated for any favorable fracture in the anterior mandibular arch that could achieve osteosynthesis with lag screw fixation, and it depends on the use of a dental arch bar as a tension band. Contraindications include unfavorable fracture patterns (long oblique, comminuted, or flat mandibular plane), inadequate dental support to maintain an arch bar due to missing or loose teeth, the inability to determine the fracture pattern preoperatively, and operator inexperience. Potential advantages include a shorter operative time, economic savings, decreased patient morbidity (swelling, scarring, and mental nerve and lower-lip muscle dysfunction), and improvement in functional rehabilitation.     

A customized fixation plate with novel structure designed by topological optimization for mandibular angle fracture based on finite element analysis

Background

The purpose of this study was to design a customized fixation plate for mandibular angle fracture using topological optimization based on the biomechanical properties of the two conventional fixation systems, and compare the results of stress, strain and displacement distributions calculated by finite element analysis (FEA).

Methods

A three-dimensional (3D) virtual mandible was reconstructed from CT images with a mimic angle fracture and a 1 mm gap between two bone segments, and then a FEA model, including volume mesh with inhomogeneous bone material properties, three loading conditions and constraints (muscles and condyles), was created to design a customized plate using topological optimization method, then the shape of the plate was referenced from the stress concentrated area on an initial part created from thickened bone surface for optimal calculation, and then the plate was formulated as “V” pattern according to dimensions of standard mini-plate finally. To compare the biomechanical behavior of the “V” plate and other conventional mini-plates for angle fracture fixation, two conventional fixation systems were used: type A, one standard mini-plate, and type B, two standard mini-plates, and the stress, strain and displacement distributions within the three fixation systems were compared and discussed.

Results

The stress, strain and displacement distributions to the angle fractured mandible with three different fixation modalities were collected, respectively, and the maximum stress for each model emerged at the mandibular ramus or screw holes. Under the same loading conditions, the maximum stress on the customized fixation system decreased 74.3, 75.6 and 70.6% compared to type A, and 34.9, 34.1, and 39.6% compared to type B. All maximum von Mises stresses of mandible were well below the allowable stress of human bone, as well as maximum principal strain. And the displacement diagram of bony segments indicated the effect of treatment with different fixation systems.

Conclusions

The customized fixation system with topological optimized structure has good biomechanical behavior for mandibular angle fracture because the stress, strain and displacement within the plate could be reduced significantly comparing to conventional “one mini-plate” or “two mini-plates” systems. The design methodology for customized fixation system could be used for other fractures in mandible or other bones to acquire better mechanical behavior of the system and improve stable environment for bone healing. And together with SLM, the customized plate with optimal structure could be designed and fabricated rapidly to satisfy the urgent time requirements for treatment.

     

Care of maxillofacial injuries: survey of plastic surgeons.

The purpose of this survey was to evaluate the current trends in the care of facial trauma. Data were obtained through the responses of a survey mailed to all those members and candidates listed in the 1989 American Society of Plastic and Reconstructive Surgeons Directory. A total of 2777 questionnaires were sent, with 1113 (40 percent) returned by means of a self-addressed envelope. Demographic results show that over 70 percent of the treating plastic surgeons fall within the age range 30 to 50 years. Although significant advances have occurred, treatment goals have remained unchanged. These center around the principles of accurate reduction and precise stabilization of fracture segments. The results of this survey reveal that a number of acceptable techniques were employed in the surgical repair of mandibular and zygomatic complex fractures. In the care of Le Fort III fractures, 59 percent of the respondents preferred the use of miniplates and screws for stabilization. Only 26.8 percent believed that facial fracture repair should be performed within the initial 24 hours. With frontal sinus fractures, the vast majority of plastic surgeons (82.1 percent) obtained a neurosurgical consultation. When the posterior wall was involved, 45.6 percent favored removal of the sinus mucosa, 29.7 percent obliterated the frontal sinus with a variety of autogenous materials, while 20.5 percent preferred cranialization. In summary, this survey shows a wide variation in the practice of facial fracture management within the plastic surgical community.     

Risk factors contributing to symptomatic plate removal in maxillofacial trauma patients

This study analyzed the fate of plates used to correct maxillofacial injuries and defined risk factors that eventually resulted in plate removal. The outpatient clinic files of 108 patients treated with rigid internal fixation after maxillofacial trauma were reviewed. Study variables included age, sex, trauma circumstances, diagnosis, type of fracture, approach to the facial skeleton, presence of teeth in the line of fracture, plate material, site of plates, and reasons for plate removal. Of 204 plates used for fixation, 44 plates (22 percent) were removed. When all factors were considered together, only fracture diagnosis (mandibular body and angle) and plate location (mandibular body and angle) were statistically significant. Only when each factor was considered separately, the approach to the facial skeleton (intraoral) and the type of fracture (comminuted and compound fractures) were statistically associated with plate removal. Selection of favorable plate location, the extraoral approach, and vigilant infection control may reduce plate removal in patients with maxillofacial injuries. Special attention should be given to compound and comminuted fractures of the mandibular body and angle.     

颞部Gillies切口在颧骨复合体骨折手术中的应用

目的:颞部Gillies切口在颧骨复合体骨折手术中的应用效果。方法:运用颞部Gillies切口治疗25例病人颧骨复合体骨折,观察手术进路,显露术区,在直视下行颧骨骨折复位内固定术。结果:25例患者应用此术式均可显露骨折区域,满足颧骨复合体骨折的手术显露需要,而且与常规颧骨复合体骨折(头皮冠状切口)手术相比,减小了出血及损伤神经的可能。结论:颞部Gillies切口在颧骨复合体骨折手术中优于其它手术路径,值得临床推广。     

Subunit principles in midface fractures: the importance of sagittal buttresses, soft-tissue reductions, and sequencing treatment of segmental fractures

The patterns of midface fractures were related to postoperative computed tomography scans and clinical results to assess the value of ordering fracture assembly in success of treatment methods. A total of 550 midface fractures were studied for their midface components and the presence of fractures in the adjacent frontal bone or mandible. Preoperative and postoperative computed tomography scans were analyzed to generate recommendations regarding exposure and postoperative stability related to fracture pattern and treatment sequence, both within the midface alone and when combined with frontal bone and mandibular fractures. Large segment (Le Fort I, II, and III) fractures were seen in 68 patients (12 percent); more comminuted midface fracture combinations were seen in 93 patients (17 percent). Midface and mandibular fractures were seen in 166 patients (30 percent). Midface, mandible, and nasoethmoid fractures were seen in 38 patients (7 percent). Frontal bone and midface fractures were seen in 131 patients (24 percent). Split-palate fractures accompanied 8 percent of midface fractures. Frontal bone, midface, and mandibular fractures were seen in 54 patients (10 percent). The midface, because of weak bone structure and comminuted fracture pattern, must therefore be considered a dependent, less stable structure. Its injuries more commonly occur with fractures of the frontal bone or mandible (two-thirds of cases) and, more often than not (>60 percent), are comminuted. Comminuted and pan-facial (multiple area) fractures deserve individualized consideration regarding the length of intermaxillary immobilization. Examples of common errors are described from this patient experience.     

Midface fractures: advantages of immediate extended open reduction and bone grafting

Experience with 240 midface (Le Fort and zygoma) fractures in multiple trauma patients has emphasized that superior aesthetic results are obtained by immediate extended open reduction with primary bone grafting. Internal fixation of 110 zygomatic and 130 Le Fort fractures was performed in the lower midface (zygomaticomaxillary and nasomaxillary buttresses). Open reduction of the condyle was employed in five concomitant Le Fort and subcondylar fractures with a loss of ramus height to prevent superior and posterior displacement of the middle and lower face. Bone grafts were utilized in 74 patients. They were most frequently employed in the orbit and less frequently in the lower midface. Bone graft survival paralleled that observed under elective conditions, and a slightly higher infection rate was observed. Extended open reduction and immediate bone grafting adds a new dimension to the aesthetic results obtained from facial fracture treatment. Structural bony integrity and pre-injury facial architecture may be restored in the absence of soft-tissue contracture. Restoration of the pre-injury facial architecture (the essence of facial fracture treatment) is more accurately accomplished when these techniques are utilized.     

Direct local approach through a W-shaped incision in moderate or severe blowout fractures of the medial orbital wall

For moderate or severe blowout fractures of the medial orbital wall, the goals of treatment are complete reduction of the herniated soft tissue and anatomic reconstruction of the wall without surgical complications. Various surgical approaches have been used, depending on the anatomic location and the extent of medial wall fracture. However, there is no consistent method to achieve the treatment goals with minimal morbidity because of one or more problems of limitation of entire medial wall exposure, limitation of large implant or bone graft insertion, surgical damage of important periorbital or intraorbital structures, or postoperative scar deformities. In this study, a direct local approach through a 3-cm, W-shaped incision on the superior medial orbital area was used as a consistent method to reconstruct medial orbital blowout fractures. The angle of the W-limbs is 110 to 120 degrees. Four limbs of the W were placed parallel or oblique to the relaxed skin tension lines. This technique was applied to 39 orbits of 37 patients with moderate or severe blowout fractures of the medial orbital wall. This approach provided exposure of the entire medial orbital wall, adequate placement of a large implant, short operation time within 2 hours, and no damage of important internal structures. Postoperative computed tomographic scans showed complete reduction of the herniated orbital tissues and anatomic reconstruction of the medial orbital wall without complication related to the surgical approach in all cases. During the follow-up period of 6 to 14 months, excellent functional and cosmetic results were observed with an inconspicuous scar without secondary scar deformities. Therefore, a direct local approach through a W-shaped incision on the superior medial orbit may be a consistent method to gain the surgical goal in treatment of moderate or severe blowout fractures of the medial orbital wall.     

Orbital roof fractures in the pediatric population

Twenty-three patients aged 3.3 +/- 1.6 years (mean +/- SD) presented between January of 1984 and September of 1987 with fronto-orbital trauma resulting in fractures of one (N = 20) or both (N = 3) orbital roofs. All patients had computed tomography (CT) with axial and coronal sections that revealed three fracture patterns of the orbital roof (nondisplaced, superiorly displaced, and inferiorly displaced fractures). Orbital dystopia was exhibited in 35 percent (N = 8) of the patients. Exophthalmos was noted in 61 percent (N = 14) of the patients. Only 30 percent of the patients (N = 7) sustained associated maxillofacial fractures. Eight percent of fractures exhibited orbital encephaloceles. All patients lacked frontal sinus pneumatization. The majority of children with orbital roof fractures do not exhibit concomitant facial fractures. CT utilizing both axial and coronal sections is valuable in defining the extent and pattern of the fracture as well as in identifying associated neurologic injuries. Large, displaced orbital roof fractures, which occurred in 3 of 13 patients with displaced fractures in our series, should undergo early reduction to avoid late development of encephalocele.     

The importance of the zygomatic arch in complex midfacial fracture repair and correction of posttraumatic orbitozygomatic deformities

Collapse of the zygomatic arch following trauma results in inadequate anteroposterior projection of the zygomatic body and an increase in facial width. Accurate assessment of the position of the zygomatic arch in relation to the cranial base posteriorly and the midface anteriorly is the key to the acute repair of complex midfacial fractures and the secondary reconstruction of posttraumatic deformities of the orbitozygomaticomaxillary complex. Loss of projection of the zygomatic arch may occur with injuries confined to the orbitozygomaticomaxillary region or in association with complex midfacial fractures. A safe anatomic approach to the zygomatic arch allows exact anatomic restoration of the zygomatic arch using miniplates and screws and results in the reconstruction of an outer facial frame with a correct anteroposterior projection and facial width. The zygomatic arch injury is diagnosed using axial CT scanning. Three-hundred and seventeen arches have been exposed through a coronal incision following acute trauma and 47 arches have been exposed in patients requiring late correction of a posttraumatic orbitozygomaticomaxillary deformity. Permanent palsy to the frontal branch of the facial nerve has occurred in one patient following the exact definition of the anatomy of this region.