Tadaaki Morotomi

Effect of Local Environment, Fibrin, and Basic Fibroblast Growth Factor Incorporation on a Canine Autologous Model of Bioengineered Cartilage Tissue

We developed a technique to form a bioabsorbable synthetic polymer (polyglycolic acid, PGA) combined with a natural polymer (fibrin) to serve as a scaffold to help retain seeded cells and improve the seeding efficiency of chondrocytes in an implantable construct. This approach was evaluated in a canine autologous implant model of bioengineered cartilage. The implantation site (subcutaneous or intrafascial) and the use of basic fibroblast growth factor (b-FGF) were also evaluated with this system. The intrafascial implantation site yielded optimal results, especially when used in conjunction with fibrin and a b-FGF sustained-release system incorporated into the complex. A thicker, more sustained cartilagenous layer was formed, with a more vascularized outer fibrous supporting tissue layer. This combined approach of implant environment selection, natural polymer for cell retention, and growth factor supplementation offers a more optimized method for generating bioengineered auricular cartilage.

Thoracic outlet syndrome after the Nuss procedure for pectus excavatum: Is it a rare complication?

OBJECTIVE The present study aims to elucidate the frequency of thoracic outlet syndrome after the Nuss procedure for pectus excavatum and the conditions in which thoracic outlet syndrome is likely to develop. METHODS A retrospective study including 85 pectus excavatum patients (58 males and 27 females) was conducted. Thoracic outlet syndrome was defined as a condition in which the patient has numbness, lassitude, or pain of the upper limbs at rest or during motion of the upper limbs. The frequency of the thus-defined thoracic outlet syndrome was evaluated in 85 patients. Age, sex, Haller indices, and the positions of the correction bars were compared between the patients who developed thoracic outlet syndrome and those who did not. RESULTS Preadolescent patients (18 out of 85) did not develop postoperative thoracic outlet syndrome. In total, 15.2% of adult male patients (7 out of 46) and 33% of adult female patients (7 out of 21) developed postoperative thoracic outlet syndrome. For both male and female groups, Haller indices were significantly greater for patients who had postoperative thoracic outlet syndrome than for those who did not. Correction bars were generally placed at higher intercostal spaces in patients who developed postoperative thoracic outlet syndrome than in those who did not. CONCLUSION A considerable percentage of adult patients develop thoracic outlet syndrome after the Nuss procedure for pectus excavatum. Maturity of the thoracic wall, femininity, severity of the deformity (represented by greater Haller indices), and placement of correction bars at superior intercostal spaces are risk factors for postoperative thoracic outlet syndrome.

Separation patterns of orbital wall and risk of optic canal injury in Le Fort 3 osteotomy

PURPOSE The authors hypothesized that the risks of optic canal injury in down-fracturing after Le Fort 3 osteotomy vary depending on the separation patterns of the orbital walls. This study verifies this hypothesis using biomechanical simulation. METHODS Ten finite-element skull models were produced using computer tomography data from ten persons. These models were modified to simulate Le Fort 3 osteotomy models by removing junctions between the neurocranium and facial cranium. The separation of the orbital wall was performed in four differing ways. In Type 1, all walls were completely separated. In Type 2, only the lateral wall was separated. In Type 3, the inferior wall was left unseparated. In Type 4, the lateral wall was left unseparated. Biomechanical simulation of down-fracturing was performed on the resulting 40 models. By observing irregular fractures occurring inside the orbit, the rate of optic canal involvement was evaluated for each of the four orbital-wall separation patterns. RESULTS The rates of optic canal involvement were: Type 1 (0/10), Type 2 (0/10), Type 3 (0/10), and Type 4 (4/10). CONCLUSION When the lateral wall is incompletely separated in Le Fort 3 osteotomy, irregular fracture can develop inside the orbit and involve the optic canal during the down-fracturing process. Hence, the lateral orbital wall should be completely separated to avoid potential blindness due to optic canal injury.

Normobaric Oxygen Therapy Increases Cartilage Survival Ratio in Auricular Composite Grafting in Rat Models

Purpose This study aims to clarify whether normobaric oxygen therapy improves the survival of auricular composite grafts in rats. Methods For 10 male SD rats, 1.5 cm2 composite grafts were harvested from bilateral ear regions including whole auricles. The harvested grafts were transferred caudally and sutured there. The 10 rats were randomly divided into two groups and kept for 21 days in two different circumstances. The first group (Control group: five rats carrying 10 grafts) was kept in room air (20% oxygen) throughout the 21 days, and the second group―named NBO (normobaric oxygen) group (five rats carrying 10 grafts)―was kept in normobaric 60% oxygen for 3 days and then in room air for 18 days. All the 10 rats were sacrificed on the 21st day. Surviving areas of the grafts and the height of the surviving auricular cartilage were examined for statistical comparison of the two groups. Furthermore, the conditions of chondrogenesis occurring around the perichondrium were compared between the two groups. Results Surviving areas did not present statistically significant differences between the two groups. The height of surviving cartilage was significantly greater for the NBO group (2610 ± 170 SD µm) than that for the Control group (1720 ± 190 SD µm). Chondrogenesis occurred at positions more distant from the recipient bed in the NBO group than that in the Control group. Conclusion Normobaric oxygen therapy increases the thickness of surviving cartilage in auricular composite grafting in rats, thus suggesting that NBO therapy may also be effective in composite grafting for humans.

Biomechanical analysis of likelihood of optic canal damage in peri-orbital fracture

Abstract Purpose: Detection of optic canal fractures is often difficult because of the subtleness of the fracture. If we could clarify impact on which region around the orbit is likely to accompany the fracture of the optic canal, the knowledge should be useful to make early diagnosis of optic canal fractures. The present study was conducted to elucidate this issue. Methods: Ten finite element models were produced simulating the skulls of ten humans (8 males and 2 females; 43.8 ± 10.2 y/o). The peri-orbital area of each of the ten models was divided into eight regions in a clockwise fashion per 45 degrees. These regions were defined as Superior-Medial (0–45 degrees), Medial-Superior (45–90 degrees), Medial-Inferior (90 to 135 degrees), Inferior-Medial (135 to 180 degrees), Inferior-Lateral (180–225 degrees), Lateral-Inferior (225 to 270 degrees), Lateral-Superior (270–315 degrees), and Superior-Lateral regions (315–360 degrees), respectively. Dynamic simulation of applying traumatic energy on each of these regions was conducted. Resultant fracture patterns were evaluated using finite element analyses. Thereafter, frequencies of fracture involvement of the optic canal were evaluated for each of the eight regions. Results: The involvement of the optic canal was most frequent for the Superior-Medial region (7/10), followed by the Medial-Superior region (5/10). Conclusion: Optic canal fracture is likely to occur when the area between the supra-orbital notch and the medial canthus are strongly impacted. When evident fracture or serious damage of soft tissue is observed in this area, occurrence of optic canal fracture should be suspected.

A biomechanical study of relationship between sternum defect patterns and thoracic respiration

Abstract Background: Various types of sternum defects are produced after the removal of thoracic tumors involving the sternum. The present study aims to elucidate the relationship between the defect patterns and their effects on thoracic respiration. Methods: Ten sets of finite element models were produced simulating thoraces of 10 persons and termed normal models. With each of the 10 normal models, the sternum was removed in six different ways to produce new models termed defect models. Defect models were categorized into hemi-superior (H-S), hemi-inferior (H-I), hemi-whole length (H-W), bilateral-superior (B-S), bilateral-inferior (B-I), and bilateral-whole length (B-W) defect types, depending on the locations of the defects. Respiratory movement was dynamically simulated with these models. The volume change the thoraces present during respiration was measured to evaluate the effectiveness of thoracic respiration. This value – defined as ΔV – was calculated and was compared between normal and defect models. Results: With H-W and B-W type models, ΔV dropped to around 20% of normal values. With H-S and B-S type models, ΔV dropped to around 50% of normal values. With H-I and B-I type models, ΔV presented values almost equivalent to those of normal models. Conclusion: Effectiveness of thoracic respiration is seriously impaired when the whole length of the sternum is absent. Reconstruction of the defect is essential for these cases. However, since the upper part of the sternum is most important for effective thoracic respiration, priority should be placed on the upper part in performing reconstruction.

Dermoscopic assessment for a brushing treatment for a patient pelted with metal fragments in an industrial explosion

deposition. LPP has been described as pruritic, brownish-black macules of patches with no active border, with site predominance on sun-exposed areas and flexural folds. The patient’s eruptions were distributed symmetrically over the body, suggesting ashy dermatosis and not LPP. FDE induced by antiepileptics was also discussed. Because the eruptions had never recurred at the same sites, FDE and the recurrence of the brain tumor were ruled out. In addition, although the patient continued to take medications every day, acute new flares occurred spontaneously and randomly. Patch tests using these drugs on pigmented lesions were all negative. Moreover, neither eosinophilia nor eosinophilic infiltration to the eruption was noticed. These observations suggested that FDE was unlikely in this case, and therefore, we diagnosed the patient with ashy dermatosis. As mentioned before, “asymptomatic’’ blue-gray patch is a characteristic of ashy dermatosis. It usually begins with disseminated macules displaying an elevated red border. However, it is difficult to observe its active inflammatory phase, and the erythematous border is infrequently seen despite its classical description. In addition, the areas can also appear as blue-gray macules from the very beginning. Identification of the itching sensation and scaling is quite rare, and we were able to find only one report of ashy dermatosis with itching in the published work. Both the pruritus and scaling observed in our case demonstrated intense inflammatory reactions, which were supported by histological observations. Considering them, we believed that ashy dermatosis is a result of melanin deposition in the dermis induced by inflammation of unknown origin. It is supposed that many “asymptomatic’’ ashy dermatoses were the result of mild inflammations which may not have been detected as erythema. The reason why such relatively strong symptoms occurred in our patient remains unknown. Our case reminds us that ashy dermatosis has a wide range of inflammation phases, and that the pigmentation can be a result of inflammation.

A Rare Case of Rapid Progression from Incurved Nail to Pincer Nail

Pincer nail, which is characterized by transverse overcurvature of the nail plate and progressive pinching distally, is a rare dystrophy of unknown pathogenesis. Several causative factors have been identified, including heredity, psoriasis, ill-fitting shoes, subungual exostoses, drug induction, trauma, and other idiopathic agents. This condition existed in many patients for extended periods before medical intervention, but the early pathology of this deformity remains unclear. We describe a rare case involving a mild incurved nail that progressed rapidly to severe pincer nail.