Chien-Tzung Chen

Endoscopically Assisted Repair of Orbital Floor Fractures

&NA; Traditionally, orbital floor fractures are repaired with standard transcutaneous or transconjunctival approaches. Complications such as external scarring, eyelid edema, ectropion, entropion, and granuloma formation have been associated with these open lid techniques. The endoscope has been used to assist in orbital floor exploration, to reduce entrapped orbital tissue, and to identify the posterior shelf for implant placement. However, an open lid incision is inevitable when implant placement is necessary. We present our experiences in repairing orbital floor fractures using transantral endoscopy without open lid incision. A 0‐degree, 4‐mm endoscope was placed through a 2 × 1.5‐cm2 maxillary antrostomy to dissect the sinus roof. The endoscope was used to assist in the reduction of the floor fractures and prolapsed orbital tissue into the orbital cavity, if present. The orbital floor defect was reconstructed with titanium mesh or Medpor through the antrostomy under endoscopic control. This technique was applied to nine patients who had orbital floor fractures. Two of the patients had zygomatico‐orbital fractures, whereas the rest had isolated orbital floor fractures. Three patients received Medpor reconstruction and the remaining six underwent titanium mesh reconstruction. The patients were followed up for 10 months on average. The enophthalmos was corrected in all patients but one, who suffered from mild enophthalmos because of uncorrected orbital medial wall fractures. Diplopia occurred in three patients preoperatively, which was resolved in two of them and improved in the other postoperatively. There have been no complications apart from transient anesthesia in the dermatome of the infraorbital nerve. The technique successfully reconstructed the orbital floor defects, minimized ocular globe manipulation, and eliminated a lower eyelid incision. (Plast. Reconstr. Surg. 108: 2011, 2001.)

Acute life-threatening injuries in facial fracture patients : A review of 1,025 patients

BACKGROUND The literature on facial fractures has emphasized obstruction of the airway as the most common associated life-threatening problem. Other life-threatening injuries associated with facial fractures are not as well documented. For this reason, we conducted a retrospective study involving 1,025 patients with facial fractures admitted to the trauma center at Chang Gung Memorial Hospital in Taiwan from January 1995 through December 1998. METHODS This study identifies the incidence of facial fractures and establishes a management plan. Life-threatening injuries associated with facial fractures were those that warranted immediate invasive rescue procedures. RESULTS Sixty-four (6.2%) of the patients with facial fractures required life-saving intervention; 21 patients had cerebral trauma prompting craniotomy, 19 had hemorrhagic shock, 17 had airway compromise, and 7 had pulmonary injury grave enough to necessitate tube thoracostomy. There were five mortalities, three due to cerebral trauma and two credited to hemorrhagic shock not identified until long after admission. CONCLUSION These findings illustrate the need for prompt identification and proper management of the associated life-threatening injuries in facial fracture patients. Clinical assessment should begin with evaluation of cerebral trauma, followed by hemorrhagic shock, airway compromise, and hemopneumothorax. Proper management may require a multidisciplinary and coordinated team approach.

Endoscopically assisted mandibular subcondylar fracture repair

The endoscope has been widely used in aesthetic surgery in recent years, but rarely has it been used in cases of facial trauma. From July of 1996 to December of 1996, the endoscope was used successfully to assist in the repair of mandibular subcondylar fractures in eight patients (five men and three women). Their ages ranged from 15 to 60 years with an average age of 31 years. Six of the patients had other associated mandibular fractures including angular, parasymphyseal, and contralateral subcondylar fractures. A 4.0-mm, 30-degree telescope was introduced to visualize the fracture site by means of an intraoral incision over the ascending ramus. A miniplate was used to stabilize the fracture site with the help of a percutaneous trocar. Intermaxillary fixation was applied for 3 to 6 days. Functionally, all patients returned to normal range of motion within 8 weeks. A slight deviation to the trauma site was noted on maximal opening in three patients, but this condition returned to normal 3 months after surgery. There was no facial palsy or lip numbness. The benefits of the endoscopic approach include not only the provision of better visualization and precise anatomic alignment of bony segments but also the avoidance of large facial scars and facial nerve injuries.

Free Functioning Muscle Transfer for Lower Extremity Posttraumatic Composite Structure and Functional Defect

Background: Traumatized lower extremities may present not only composite soft-tissue defects but also flexor and/or extensor loss. Free functioning muscle transfer can provide composite structural and functional restoration. Methods: From 1996 to 2004, 19 patients with lower extremity injuries whose lesions exhibited composite soft-tissue damage, with or without bone defects, and certain accompanying functional disabilities were allocated to study groups on the basis of impression, as follows: group I, open fracture IIIB (n = 10); group II, neglected compartment syndromes [open IIIB (n = 4) and open IIIC (n = 1)]; and group III, crush injuries (n = 4). Free flap resurfacing was indicated for these lesions. Fifteen patients underwent free functioning muscle transfer; source muscles were the rectus femoris (n = 3), rectus femoris with anterolateral thigh flap (n = 5), and gracilis (for ankle dorsiflexion) (n = 7). Two patients underwent composite rectus femoris and vascular iliac crest for ankle dorsiflexion and segmental tibial defect reconstruction. Two received rectus femoris muscle and anterolateral thigh flaps for posterior compartment defect and quadriceps defect reconstruction, individually. Results: Two patients required reexploration; salvage was successful in only one, with below-knee amputation necessary in the other. Skin grafts were needed for partial skin paddle necrosis (n = 3) or remaining skin defect (n = 2). Functioning muscle reinnervation failed in four cases, with one individual undergoing ankle fusion, two people electing ambulation with stiff ankles, and one person using an orthosis. In the sample population, range of motion varied and was related to the severity of injury and the extent of skin grafting on the distal musculotendinous portion. Less function was exhibited in the compartment syndrome group (group II). Conclusion: Functioning muscle transfer can be performed posttraumatically in lower limbs with composite soft-tissue and motor-unit defects, resulting in acceptable functional results and reliable limb salvage.

Functional results of unilateral mandibular condylar process fractures after open and closed treatment.

BACKGROUND This retrospective study compared the functional results of unilateral mandibular condylar process fractures treated either by open reduction or by closed treatment. METHODS Sixty-six patients with unilateral mandibular condylar process fractures were reviewed. Thirty-six patients received open reduction, and the other 30 underwent closed treatment (intermaxillary fixation only). Each group was further divided into condylar and subcondylar subgroups according to fracture level. The functional outcome was evaluated by posttreatment occlusion status, maximal mouth opening, facial symmetry, chin deviation, and temporomandibular joint symptoms. RESULTS Patients undergoing closed treatment exhibited more condylar motility than those treated by open reduction. Patients in the condylar subgroup with open reduction presented less chin deviation (21.43%) compared with those with closed treatment (56.25%; p = 0.072). Although a greater severity of subcondylar fractures existed in patients treated with open reduction, patients treated with open reduction or closed treatment did not reveal a significantly functional difference. CONCLUSION The present study revealed that patients with condylar neck or head fractures gained more benefits from open reduction in terms of chin deviation and temporomandibular joint pain. For subcondylar fractures, open reduction provides satisfactory functional results in patients with severely displaced fractures.

Endoscopically assisted repair of frontal sinus fracture.

BACKGROUND Classic approaches to frontal sinus fracture involve bicoronal or direct forehead incisions. However, these incisions cause paresthesia, scarring, and even alopecia. In the field of plastic and reconstructive surgery, endoscopically assisted surgery is now widely accepted, particularly for esthetic surgery. It also is applied for the management of midface and lower-face fractures, but rarely for treatment of the frontal area. The authors present their experience with the repair of frontal sinus fractures using the endoscopically assisted method. METHODS The surgery was performed with the patients under general anesthesia. Two slit incisions were placed in the hair-bearing area, through which a 4-mm 30 degrees endoscope was inserted. The subperiosteal dissection was performed toward the fracture site using an endoscopic periosteal elevator. The depressed fracture segments of the anterior table of the frontal sinus were reduced and fixed with microplates to restore the contour of the forehead. Seven consecutive patients received endoscopic correction of frontal sinus depressed fractures. RESULTS No patients required conversion conventional bicoronal incisions. Good anatomic reduction of the fracture sites, acceptable surgical scar, and esthetic recontour were obtained in all the patients. The postoperative course was uneventful, without any complications. CONCLUSION The endoscopically assisted method allows feasible reduction and fixation of a frontal sinus fracture. It avoids the complications of traditional methods and yields improved convalescence and esthetic results. It also helps in the diagnosis of unsuspected cerebrospinal fluid leaks. Thus, for anterior table fractures with an intact nasofrontal duct, endoscopically assisted surgery provides an alternative option of treatment.

Free flap reconstruction of foot and ankle defects in pediatric patients: long-term outcome in 91 cases.

Background: Free tissue transfer has not been fully adopted as the primary mode of treating foot and ankle defects in potentially indicated patients, partly because of the lack of sizable vessels and the potential in the long term of differential growth in the flap and the recipient site. Also lacking are long-term outcome studies in these growing patients. Methods: Between 1989 and 2002, 91 children with 93 foot and ankle defects underwent microsurgical reconstructions. The patients underwent reconstruction with flaps with a cutaneous component or with muscle flaps (skin-grafted). Results: Fifty-eight defects were reconstructed with cutaneous/musculocutaneous flaps (37 fasciocutaneous and 21 musculocutaneous flaps), and 35 were reconstructed with skin-grafted muscle flaps. Thirteen patients underwent secondary free flap surgery, for a total of 106 flaps used to complete the reconstructions. Twelve cases underwent reexploration, and overall survival was 95.3 percent (101 of 106). Secondary deformities were present in 37.9 percent of skin/musculocutaneous flaps and 58.9 percent of skin-grafted muscle flaps (p = 0.029). More resurfacing procedures were performed in skin-grafted muscle flaps than in skin/musculocutaneous flaps (32.4 percent versus 12.1 percent; p = 0.0386). Conclusions: Free tissue transfer in pediatric patients is a viable and reliable option. Skin/musculocutaneous flaps and skin-grafted muscle flaps both had equal survival rates; however, flaps with a skin component required fewer secondary procedures to correct deformities. Whenever a skin component was present, it provided useful tissue during the secondary procedure and minimized complications. For plantar foot reconstructions, skin-grafted muscle flaps demonstrated a higher incidence of trophic ulcers and a higher need for resurfacing procedures than flaps with a skin component. Reconstructions of tendons in the immediate setting led to fewer secondary operations than staged tendon reconstructions.

Surface modification of polycaprolactone scaffolds fabricated via selective laser sintering for cartilage tissue engineering

Surface modified porous polycaprolactone scaffolds fabricated via rapid prototyping techniques were evaluated for cartilage tissue engineering purposes. Polycaprolactone scaffolds manufactured by selective laser sintering (SLS) were surface modified through immersion coating with either gelatin or collagen. Three groups of scaffolds were created and compared for both mechanical and biological properties. Surface modification with collagen or gelatin improved the hydrophilicity, water uptake and mechanical strength of the pristine scaffold. From microscopic observations and biochemical analysis, collagen-modified scaffold was the best for cartilage tissue engineering in terms of cell proliferation and extracellular matrix production. Chondrocytes/collagen-modified scaffold constructs were implanted subdermally in the dorsal spaces of female nude mice. Histological and immunohistochemical staining of the retrieved implants after 8 weeks revealed enhanced cartilage tissue formation. We conclude that collagen surface modification through immersion coating on SLS-manufactured scaffolds is a feasible scaffold for cartilage tissue engineering in craniofacial reconstruction.

Osteogenic Differentiation and Ectopic Bone Formation of Canine Bone Marrow-Derived Mesenchymal Stem Cells in Injectable Thermo-Responsive Polymer Hydrogel

This study describes an injectable, thermo-responsive hyaluronic acid-g-chitosan-g-poly(N-isopropylacrylamide) (HA-CPN) copolymer for bone tissue engineering. The wettability, temperature-dependent change of water content, and volume of HA-CPN hydrogel were measured, together with its biocompatibility in vitro and in vivo. The dried hydrogel morphology shows a three-dimensional, porous structure with interconnected pores. Canine bone marrow-derived mesenchymal stem cells (cBMSCs) were encapsulated in HA-CPN hydrogel and osteoinduction was assessed by comparing samples with different osteogenic differentiation induction times but with the same total cell culture time. Cell proliferation and time-dependent osteogenic differentiation, evident from secretion of extracellular matrix and formation of mineral deposits, were observed. The cells showed better proliferation in HA-CPN hydrogel than on tissue culture polystyrene after osteo-induced for 21 days and higher alkaline phosphatase activity regardless of osteo-induction times. Mineralization extent of cBMSCs in HA-CPN followed by Alizarin red stains showed positive stained nodules after osteo-induced longer than 7 days. The cells/hydrogel construct also showed increased mechanical strength and elasticity after osteogenic differentiation, and the increase could be correlated with osteo-induction time. In vivo studies confirmed the biocompatibility and bioresorption of the HA-CPN hydrogel and ectopic bone formation when the hydrogel was used as a cell carrier for osteo-induced cBMSCs and implanted in nude mice subcutaneously. Taken together, the results indicate the feasibility and efficacy of HA-CPN hydrogel as an injectable bone tissue engineering scaffold with cBMSCs.

Combination of guided osteogenesis with autologous platelet-rich fibrin glue and mesenchymal stem cell for mandibular reconstruction.

BACKGROUND This study examined whether a combination of autologous platelet-rich fibrin glue (PRFG) with mesenchymal stem cells (MSCs) and MEDPOR as guided tissue regeneration (GTR) could act as an osteogenic substitute and whether this treatment yields faster new bone formation than MEDPOR alone or PRFG plus MSC. MATERIAL MSCs were harvested and isolated from the bone marrow of dog ilium. Full-thickness bony defects (1.5×1.5 cm) were created in the bilateral mandible angles of the dog. Treatments for bone defect in each group were as follows: group I (n=4), MEDPOR sheet as GTR and autologous PRFG/MSCs admixtures; group II (n=4), autologous PRFG/MSCs admixtures; group III (n=4), MEDPOR sheet as GTR; and group IV (n=4), control (empty defect). The percentage of new bone regeneration in computerized tomography at 2 months and 4 months was calculated by Analyze version 7.0 software. The mandibles were harvested from all specimens at 4 months, and the grafted sites were evaluated by gross, histologic, and X-ray examination. RESULTS By radiographic analysis at 16 weeks posttransplantation, it was shown that an average of 72.8%±8.02% new bone formation in group I, 53.34%±6.87% in group II, 26.58%±6.41% in group III, and 15.14%±2.37% in group IV. Histologic examination revealed that the defect was repaired by typical bone tissue in groups I and II, whereas only minimal bone formation with fibrous connection was observed in the groups III and IV group. Besides, muscle incarceration was found in groups II and IV without MEDPOR as GTR. CONCLUSION Autologous PRFG plus osteoinduced MSCs have good potential for bone regeneration. In combination with MEDPOR as GTR, bone regeneration is enhanced by preventing soft tissue ingrowth hindering bone regeneration.