Craig A. Vander Kolk

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 tendonbearing 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.

Microvascular Soft-tissue Transplantation for Reconstruction of Acute Open Tibial Fractures: Timing of Coverage and Long-term Functional Results

Seventy-two patients with Gustilo grade IIIB open tibial fractures were treated with free-tissue transfers. If successful free-tissue transfer for soft-tissue reconstruction is performed within 15 days of injury, the risk of major complications is 3.6 percent. Long-term retrospective follow-up (mean 42 months) revealed successful limb salvage in 93 percent, good aesthetic results in 80 percent, and patient satisfaction in 96 percent. However, 66 percent of patients exhibited significantly decreased range of motion of the ankle, 44 percent experienced swelling and edema requiring elastic support and activity modification, and 50 percent occasionally required an assistance device for ambulation. The long-term employment rate was 28 percent, and no patient returned to work after 2 years of unemployment. In contrast, 68 percent of amputees after lower extremity trauma over the same period returned to work within 2 years. Patients need to realize the disruptive nature of this injury on their family, job, and future.

Long-term results of flap reconstruction in median sternotomy wound infections.

Reconstruction of infected median sternotomy wounds using muscle and omental flaps has been shown to result in significantly reduced morbidity, mortality, and length of hospital stay. Despite these benefits, very little is known about the potential long-term sequelae of such procedures. The purpose of this study was therefore to evaluate the ultimate functional outcome in such patients. One-hundred and thirty-three consecutive patients underwent debridement and flap reconstruction of their infected median sternotomy wounds over an 8-year period. Eighty patients were available for follow-up and responded to a questionnaire. Forty-eight patients consented to a physical examination. The length of follow-up ranged from 15 to 108 months (average 48 months). Healed wounds were obtained in 99 percent of patients. Fifty-one percent of patients noted persistent pain or discomfort, particularly in the chest and shoulder. Forty-four percent noted areas of numbness/paresthesias, mainly on the chest. Thirty-four patients (42.5 percent) noted symptoms of sternal instability; of those consenting to an examination, 45 percent were confirmed to have instability. Twenty-six patients (32.5 percent) claimed postoperative weakness (shoulder/abdomen). Significant shoulder weakness was not demonstrated; however, abdominal weakness was substantial. Thirty-six percent of patients reported an inability to perform the same preoperative activities that were of importance to them (sports, housework, etc.). Of those patients eligible to return to work, 52 percent did not. Patients younger than age 60 had a somewhat higher chance of not returning to work. Scars were noted to be good to excellent in 75 percent, but contour abnormalities of the chest and abdomen were found in 85 percent. Abdominal-wall pathology (hernias/bulges) was present in 31 percent of patients, including 10 of 19 patients having rectus abdominis flaps, 2 of 3 patients having omental flaps, and 3 of 41 patients having isolated pectoralis major flaps. Shoulder range of motion was not noticeably affected by operation. Despite the proven advantages of flap reconstruction in mediastinitis, these procedures are not without long-term sequelae. Possible methods of preventing these problems are discussed. (Plast. Reconstr. Surg. 93: 1208, 1994.)

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.

Standardizing digital photography: it's not all in the eye of the beholder.

Advances in digital photography have made it an efficient and economically appealing alternative to conventional photography. Nevertheless, as objective observers and clinical photographers, we must realize that all digital cameras are not created equal. Different digital cameras frequently used in plastic surgery practices (Olympus 600DL, Olympus 2500, Sony DSC-D700, Nikon Coolpix 950, and Nikon D1) were evaluated, using a subject photographed with each camera in the identical lighting conditions, to determine inherent differences in quality, color, and contrast of the resultant photographs. Three different lighting conditions were examined: single soft-box lighting, dual studio flash boxes, and operating room lighting with on-camera flash. The same digital settings (program mode, ISO camera default setting, high quality setting with JPEG compression) were used. Each camera was digitally color balanced using an 18 percent gray card. Raw and color-balanced images were viewed side-by-side. The macro-image capabilities of each camera were also examined. Conventional 35-mm photographs using a 105 macro-lens on Kodachrome and Ektachrome slide film were obtained for comparison. All of the digital cameras performed with noticeable differences, but they maintained consistency in the three different lighting conditions. Digital photographs differed most greatly with respect to quality and contrast, which was especially obvious once color balancing was performed. Marked differences in quality and ability were observed with respect to macro-image capabilities. Inherent differences in features among digital cameras produce dramatically different photographic results with regard to color, contrast, focus, and overall quality. With the increasing use of digital photography in plastic surgery journals and presentations, it must be recognized that digital cameras do not all display photographs of similar quality, especially when used to evaluate skin appearance. To standardize digital photography, the surgeon must realize that switching digital cameras is akin to switching film types. Standardization of digital photographs should include image resolution between 1.5 and 2.7 million pixels, ISO default setting, color balancing with an 18 percent gray card and software, consistency in focal distance, JPEG compression of medium-to-high quality, and backgrounds of medium blue or 18 percent gray.

CALLUS STIMULATION IN DISTRACTION OSTEOGENESIS

Distraction osteogenesis has been described as in vivo tissue engineering. The ability to stimulate this process for the repair of bony defects or lengthening of congenitally shortened facial structures is likely to significantly impact the field of craniofacial surgery. The purpose of this study was to determine whether mechanical stimulation of the distracted rabbit mandible would accelerate the maturation of the bony callus when applied during the early consolidation period. Twenty adult New Zealand White rabbits underwent unilateral mandibular osteotomy. A uni-directional internal distractor device (Synthes, Paoli, Pa.) was positioned along a plane perpendicular to the line of osteotomy. After a 7-day latency period, distraction was commenced at a rate of 1.0 mm/day for 12 days in all animals. In a control group of 10 rabbits, a consolidation period of 8 weeks was observed before they were killed. In the experimental group of 10 rabbits, daily alternate compression and distraction of 1 mm (sequential compression and distraction) was performed for 3 weeks followed by a 5-week period of rigid fixation. Each animal received a dose of a fluorescent label at three different time points during the study: at the end of the distraction period, 3 weeks after the completion of the distraction phase, and 3 days before it was killed. All animals were killed 8 weeks after the completion of the distraction phase. Undecalcified histologic analysis and 3-point bending tests to failure were performed on the extracted mandibles. The results of the experimental and control groups were compared. Four animals in the control group and three animals in the experimental group were excluded from the study because of screw loosening resulting in distractor dislodgment or because of infection. On histologic analysis, cortical thickness at the center of the callus was found to be significantly greater in the experimental group compared with the control group when normalized to the contralateral hemimandible (83 percent versus 49 percent, respectively; p < 0.007). The ratio of cortical to cancellous bone in the distracted callus was uniformly found to be greater in the experimental specimens. The mineral apposition rate was calculated by using fluorescence microscopy and found to be significantly greater in the experimental group both during the period of sequential compression and distraction (3.2 microm/day versus 2.1 microm/day, p = 0.02) and after the period of sequential compression and distraction (1.4 microm/day versus 1.1 microm/day, p = 0.006). Mechanical testing revealed no significant differences in bending strength or stiffness between experimental or control groups (p = 0.54 and 0.47, respectively). This study has demonstrated that daily alternating compression and distraction of 1 mm amplitude during the early consolidation period has a stimulatory impact on callus formation with respect to osteoblastic activity, remodeling, and maturation of bone. Optimal timing and amplitude of sequential movement, long-term biomechanical differences, and molecular pathways have yet to be elucidated.

Biocompatibility of fixation materials in the brain

&NA; Recent clinical reports documenting passive intracranial translocation of microplates and microscrews have prompted concerns regarding brain biocompatibility and neurotoxicity of fixation hardware used in craniofacial surgery. Although the effects of commercially pure titanium, Vitallium (cobalt‐chromium‐molybdenum), stainless steel, and various alloys have been well assessed in bone and soft tissues, there are no comprehensive studies of these materials in the brain. To investigate this, the biocompatibility of titanium, Vitallium, and 316L stainless steel was evaluated in the rabbit brain and compared with silicone elastomer shunt tubing, a material that is used commonly as a neurosurgical implant material with wellestablished brain biocompatibility. Forty‐eight juvenile New Zealand White rabbits were randomly assigned to one of three groups and underwent placement of either commercially pure titanium microscrews, Vitallium microscrews, or 316L monofilament stainless steel wire into the parietal region. Silicone elastomer strips of similar size were implanted in the contralateral hemisphere of each rabbit. Animals were assessed daily for signs of neurotoxicity. Rabbits in each group were sacrificed at 2, 4, 8, and 26 weeks following implantation. Brains were sectioned at the implantation site and were examined by means of standard hematoxylin and eosin stains and with immunohistochemical markers sensitive to inflammatory changes in the brain. None of the animals showed any behavioral changes or neurologic deficits suggestive of either systemic or localized toxicity from the implant materials. Silicone elastomer was found to cause the least amount of inflammation relative to other materials tested at all sacrifice points, suggesting that as a standard neurosurgical implant material, it is an appropriate control for studies of brain biocompatibility. At 2 weeks, titanium was found to cause the largest inflammatory response in surrounding brain parenchyma based on analysis of markers for microglial proliferation, gliosis, and leukocyte infiltration. At the 26‐week endpoint of our study, the biocompatibility of titanium was nearly equal to the biocompatibility of Vitallium based on all studied markers of inflammation. A progressive increase in the inflammatory response surrounding stainless steel implants was noted at 8 and 26 weeks. Relative to all materials studied, at 26 weeks the greatest leukocyte response was found with stainless steel implants. Our results indicate that at the 26‐week endpoint of our study, titanium and Vitallium incited a similar inflammatory response in the rabbit brain that was greater than the response found with silicone elastomer, a standard neurosurgical implant material, but less than that found with stainless steel wire, which is commonly recommended as an alternative fixation material. (Plast. Reconstr. Surg. 100: 14, 1997.)

Converting to digital photography : A model for a large group or academic practice

Digital photography has become an economical and efficient substitute for conventional photography. We recently converted our resident clinical photography to a digital format to make archiving more efficient and to save the costs of clinical photography. We present a model that can be applied to a large group or academic practice outlining the conversion of our clinical photography to digital format. We discuss the costs that we have incurred during the past 3 years of conventional photography, the economic benefit and costs for conversion to digital, and a 5-year projection of savings using digital photography. We also discuss the advantages of digital photography and the equipment needed for the conversion.

Spring-mediated mandibular distraction osteogenesis

Successful performance of distraction osteogenesis requires rigorous patient compliance with a daily activation regimen of a percutaneous screw. Previous clinical studies have found that failure of patient compliance with this regimen is the most common complication leading to technical failure of the distraction process. The authors have developed an internalized spring-mediated device for mandibular distraction osteogenesis that can potentially abrogate the risks associated with patient compliance by allowing for automated distraction across an osteotomy. Twenty adult New Zealand White rabbits underwent unilateral mandibular osteotomy. A segment of nickel–titanium shape memory alloy reinforced at both ends with a pinball was fashioned into an inferiorly based arc and secured to the mandible with stainless steel wire. On postoperative day 12, spring activation commenced by cutting a wire binding the two pinballs to one another. Animals were observed for 6 weeks before they were killed. Radiographic studies and decalcified histologic analysis were performed on extracted mandibles. Temperature- and displacement-dependent properties of the shape memory alloy were also examined. Five animals were excluded from the study due to infection, nonunion, or device failure. A mean distraction of 1.2 mm in the distracted hemimandible relative to the nonoperated hemimandible was found (P < .001, two-tailed paired t test). The maximum distraction achieved in an experimental specimen using the spring distractor was 3.7 mm. There were no other histologic or radiographic differences found between study specimens and specimens subjected to traditional distraction methods. Biomechanical testing of the shape memory alloy revealed a temperature-dependent increase in force at body temperature compared with room temperature and a reduction in force with increased displacement of the spring. This study demonstrates the feasibility of spring-mediated distraction osteogenesis across an osteotomy. As the field of distraction osteogenesis matures, the next level of sophistication in the clinical development of devices will incorporate technology that permits fully internalized and automated distraction to occur.

Three-dimensional reconstruction of the human fetal philtrum

The anatomy of the philtrum is incompletely understood because it is difficult to analyze three-dimensionally. Previous anatomic studies suggested that the philtral ridges are formed by the dermal insertion of the orbicularis oris muscle and musculis nasalis decussating across the midline, with the philtral dimple an area of few muscular insertions. This theory is inconsistent with the usual finding of a normal-appearing philtrum contralateral to the cleft in patients with unilateral cleft lip. Using a microcomputer and three-dimensional software, we have created a three-dimensional model of the philtrum from digitized images of sequential transverse histological sections from a third-trimester fetus. Our studies demonstrate that the philtral ridges are formed by thickened dermis and dermal appendages. The labial levators are the predominant muscles associated with the philtrum throughout its length; their fibers insert into the dermis lateral to the philtral ridges. Crossing muscle fibers of the orbicularis oris pars marginalis only appear below the vermilion-cutaneous junction, caudal to the philtral ridges.