Faculty Bibliography

INTRODUCTION: Injuries to the ulnar collateral ligament (UCL) are relatively common and are best treated in the acute setting. The acute version of this injury can often be repaired primarily but in the chronic setting the ligamentous remnants are often retracted making this method of repair difficult. We present a novel alternative approach for UCL repair after chronic injuries or difficult acute injuries. METHODS: We describe the procedure and postoperative results. A standard S-shaped incision over the dorsal ulnar aspect of the thumb is used. The adductor aponeurosis is identified and separated from the joint capsule. A proximally based and distally based rectangular flap containing the UCL remnants is elevated exposing the metacarpophalangeal joint. A burr is used to shave the condyles on the ulnar aspect of the metacarpal and proximal phalanx. The joint is stabilized with a Kirschner wire. A suture anchor is used to secure the proximally based flap. The distal flap is secured on top of this using the same sutures from the anchor. The repaired ligament is secured to the volar plate on the palmar aspect using a 4-0 Ethibond. RESULTS: This surgical technique has been used extensively by the senior authors; we present a representative case. At 3 months the patient had a grip strength of 85 lbs, tripod pinch of 12 lbs, lateral pinch of 5 lbs, 2-point pinch of 6 lbs, active range of motion at metacarpophalangeal joint of 0 to 70 and passive range of motion at the metacarpophalangeal joint MP of 0 to 85. CONCLUSION: Despite a number of options for ligament reconstruction many of the described methods of repair are relatively complex and involve derangement of local tissues. We offer a novel adjunct to current methods of UCL reconstruction in which condylar shaving makes repair much more simple and avoids the use of a tendon graft. This approach provides a shorter course for the retracted UCL remnants allowing primary repair in the chronic setting and in the difficult acute repair

In the last two decades, the anterolateral thigh flap has emerged as one of the most popular reconstructive options for multiple body sites. Based on a perforator flap harvest concept, the flap encompasses the advantages of versatility, pliability, and potential for composite tissue replacement. Although numerous anatomical variations exist, these are well-described, and flap safety remains uncompromised if certain anatomical boundaries are respected. Careful preoperative planning and identification of perforators remain the cornerstone of successful flap harvest. Once perforators are identified, variations in skin paddle design allow for multiple skin paddle configurations, central or eccentric orientations, and custom-made flaps tailored to fit almost any defect. A suprafascial dissection allows for "ultra-thin" flaps ideal for folding, tubing, or packing purposes. The versatility of the lateral circumflex femoral artery branches can be exploited to include muscle, iliac bone, tendon, fascia, or nerve in extended designs. The anterolateral thigh flap is currently the frontline choice for head and neck reconstruction, including intraoral, mandibular-maxillary, tongue, and facial defects, and is gaining popularity in abdominal and pelvis reconstruction. It can also be used as a pedicled flap in phallus or perineum reconstruction. More recently, the flap has proved to be extremely useful in skin resurfacing and even functional reconstruction in traumatic wounds. This review summarizes the anatomy, planning, flap harvest, donor morbidity, and clinical applications of the anterolateral thigh flap. An algorithm is proposed that facilitates a clear, problem-based approach for the use of this versatile reconstructive option.

BACKGROUND: Primary alveolar cleft repair has a 41 to 73 percent success rate. Patients with persistent alveolar defects require secondary bone grafting. The authors investigated scaffold-based therapies designed to augment the success of alveolar repair. METHODS: Critical-size, 7 x 4 x 3-mm alveolar defects were created surgically in 60 Sprague-Dawley rats. Four scaffold treatment arms were tested: absorbable collagen sponge, absorbable collagen sponge plus recombinant human bone morphogenetic protein-2 (rhBMP-2), hydroxyapatite-tricalcium phosphate, hydroxyapatite-tricalcium phosphate plus rhBMP-2, and no scaffold. New bone formation was assessed radiomorphometrically and histomorphometrically at 4, 8, and 12 weeks. RESULTS: Radiomorphometrically, untreated animals formed 43 +/- 6 percent, 53 +/- 8 percent, and 48 +/- 3 percent new bone at 4, 8, and 12 weeks, respectively. Animals treated with absorbable collagen sponge formed 50 +/- 6 percent, 79 +/- 9 percent, and 69 +/- 7 percent new bone, respectively. Absorbable collagen sponge plus rhBMP-2-treated animals formed 49 +/- 2 percent, 71 +/- 6 percent, and 66 +/- 7 percent new bone, respectively. Hydroxyapatite-tricalcium phosphate treatment stimulated 69 +/- 12 percent, 86 +/- 3 percent (p < 0.05), and 87 +/- 14 percent new bone, respectively. Histomorphometry demonstrated an increase in bone formation in animals treated with hydroxyapatite-tricalcium phosphate plus rhBMP-2 (p < 0.05; 4 weeks) compared with empty scaffold. CONCLUSIONS: Radiomorphometrically, absorbable collagen sponge and hydroxyapatite-tricalcium phosphate scaffolds induced more bone formation than untreated controls. The rhBMP-2 added a small but significant histomorphometric osteogenic advantage to the hydroxyapatite-tricalcium phosphate scaffold.

Peripheral nerve defects are common. The surgeon faced with these problems must provide the best functional recovery for the patient with the tools provided. The ideal nerve reconstruction would create a tensionless repair with direct coaptation. However, this is not always possible and other techniques must be employed. The alternatives to direct coaptation include nerve autografts, nerve conduits, and tissue-engineered constructs. This article reviews commonly used autogenous nerve grafts and conduits. Autogenous nerve grafts have been utilized in various techniques which include the trunk graft, cable graft, interfascicular graft, and vascularized graft. The nerve conduits reviewed fall into the category of autogenous biological conduits, nonautogenous biological conduits, and nonbiological conduits. New technologies are being developed to enhance peripheral nerve regeneration with the concept that conduits can be enriched and manipulated in the laboratory to promote regeneration of the peripheral nerve. Further clinical studies hold the promise of successful alternatives for treating peripheral nerve injuries

BACKGROUND: Frontobasal injury is a classic craniomaxillofacial fracture affecting the anterior cranial base. No data exist regarding the degree of frontobasal injury and associated midfacial fractures. The authors propose a classification of frontobasal and midface fractures involving the cranial base based on cadaveric experiments and comprehensive clinical experience. METHODS: An institutional review board-approved retrospective review was conducted on patients with frontobasal fractures from 1995 to 2005. Fractures were categorized by pattern, location, midfacial involvement (impure), and complications compiled. One hundred five cadaveric heads underwent blunt impact to the frontal bone and upper midface. Calvarial vault, cranial base, and midface fracture patterns were categorized. RESULTS: Three frontobasal fracture patterns were identified. Isolated linear cranial base fractures constitute type I. Vertical-linear fractures of the skull vault (frontal bone) occur in combination with base fractures, representing type II (vault and base). Comminution of the frontolateral skull vault and orbital roof in association with a linear base fracture constitute type III. Two hundred ninety patients were identified with 49 complications (cerebrospinal fistula, 24; and infectious 25). Type III (n = 159) had the highest complication rate (impure, 29 percent; pure, 17 percent), followed by type II (impure, 19 percent; pure, 5 percent). There is essentially no extension of midface fractures to the cranial vault. CONCLUSIONS: Frontobasal fractures have three unique and reproducible patterns based on vector, location, and force. This new classification scheme, paired with known patterns of midfacial injuries, assists in fully understanding frontofaciobasal injury and its complications. Overwhelmingly, impure type II and any type III fractures are associated with a high rate of complications and must be carefully managed.

Blood vessel growth is regulated by angiogenic and angiostatic CXC chemokines, and radiation is a vasculogenic stimulus. We investigated the effect of radiation on endothelial cell chemokine signaling, receptor expression, and migration and apoptosis. Human umbilical vein endothelial cells were exposed to a single fraction of 0, 5, or 20Gy of ionizing radiation (IR). All vasculogenic chemokines (CXCL1-3/5-8) increased 3-13-fold after 5 or 20Gy IR. 20Gy induced a marked increase (1.6-4-fold) in angiostatic CXC chemokines. CXCR4 expression increased 3.5 and 7-fold at 48h after 5 and 20Gy, respectively. Bone marrow progenitor cell chemotaxis was augmented by conditioned media from cells treated with 5Gy IR. Whereas 5Gy markedly decreased intrinsic cell apoptosis (0Gy=16%+/-3.6 vs. 5Gy=4.5%+/-0.3), 20Gy increased it (21.4%+/-1.2); a reflection of pro-survival angiogenic chemokine expression. Radiation induces a dose-dependent increase in pro-angiogenic CXC chemokines and CXCR4. In contrast, angiostatic chemokines and apoptosis were induced at higher (20Gy) radiation doses. Cell migration improved significantly following 5Gy, but not 20Gy IR. Collectively, these data suggest that lower doses of IR induce an angiogenic cascade while higher doses produce an angiostatic profile

BACKGROUND: Most reconstructions for lower lip palsy focus on paralyzing the contralateral normal lip or providing static support on the affected side. The authors' unit has reported dynamic strategies for lower lip reanimation and use of 40 percent of the hypoglossal nerve (mini-hypoglossal) in facial reanimation. They report their experience with mini-hypoglossal nerve transfer for lower lip palsy. METHODS: Between 1987 and 2005, 29 patients with unilateral facial palsy had lower lip reanimation with the mini-hypoglossal as the motor donor. Twenty patients had transfer of the mini-hypoglossal to the cervicofacial branch of the facial nerve and nine had direct depressor muscle neurotization. Five patients had a mean denervation time of 14.60 +/- 4.50 months (<2 years), and the rest had a mean denervation time of 10.63 +/- 9.23 years. In late cases, the facial nerve was in-continuity, and preoperative needle electromyographs of depressors showed at least fibrillations. Standardized videos taken preoperatively and at 2 years postoperatively were available for 27 patients and assessed by three independent reviewers. Needle electromyographic results were analyzed. RESULTS: Thirteen patients (48.15 percent) achieved excellent and good results, nine (33.33 percent) had moderate results, and five (18.52 percent) obtained fair results. The difference between the averaged preoperative and postoperative scores was statistically significant, as was the difference in electromyographic outcomes (p < 0.0001, Wilcoxon signed rank test). The nerve transfer and direct neurotization groups had no statistically significant difference in clinical and electromyographic outcomes. Four patients required muscle transfer for further outcome upgrading. CONCLUSION: Use of the mini-hypoglossal either for nerve transfer or for direct muscle neurotization of lower lip depressors can provide reinnervation and satisfactory clinical function, even for muscles with prolonged partial denervation

PURPOSE: The objective of this study was to evaluate the bone response to a nanothickness bioceramic ion beam-assisted deposition (IBAD) on endosteal implants in a canine model. MATERIALS AND METHODS: Alumina-blasted/acid-etched (control) and IBAD-modified (test) implants were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy + ion beam milling, thin-film mode X-ray diffraction, and atomic force microscope. The implants were surgically placed in four dogs' proximal tibiae and remained for 2 and 4 weeks in vivo. Oxytetracycline (10 mg/kg) was administered for bone labeling 48 hours prior to euthanization. Following euthanization, nondecalcified thin sections were prepared for UV and transmitted light microscopy. The amount of bone labeling was evaluated along the length and away from the implant surface by means of a computer software. The % bone-to-implant contact (BIC) was determined for each specimen. One-way analysis of variance at 95% level of significance along with Tukey's post hoc multiple comparisons were utilized for statistical evaluation. The characterization showed Ca- and P-based amorphous coatings with a 20- to 50-nm thickness. RESULTS: In vivo results showed a significant increase in general and site-specific (to 0.5 mm from the implant surface) bone activity for the 4-week test implants compared with the control implants. Bone activity levels decreased as a function of distance from the implant surface for all groups. No significant differences in BIC were observed between groups. CONCLUSIONS: This study showed that both surfaces were biocompatible and osteoconductive and that a time-dependent increase in osteoactivity occurred around the test implants.