Effects of the hyperbaric oxygen on de novo bone formation during periosteal distraction.

OBJECTIVE: The purpose of this study was to investigate the effect of hyperbaric oxygen (HBO) therapy on de novo bone formation during periosteal distraction (PD). MATERIALS AND METHODS: Periosteal distraction was performed in 24 mature male New Zealand rabbits using a custom-designed device placed on the lateral surface of the mandibular corpus. Twelve rabbits (group H) were given adjunctive HBO treatment, whereas 12 rabbits (group N) were kept in a normal environment (normobaric oxygen). After a 7-day latency period, the same distraction protocol was applied to both groups. However, the rabbits in group H were treated with pure oxygen at 2.4 atm absolute for 25 times. Both groups were further divided into 2 subgroups and killed after consolidation periods of 4 and 8 weeks. Photodensitometric and histologic analyses were performed to evaluate the newly formed bone. RESULTS: There was no significant difference between the 4-week consolidated HBO group and the 8-week consolidated normobaric oxygen subgroup (P = 0.229). Moreover, there was better bone formation in the 8-week HBO group than in the 8-week control group. CONCLUSION: The results of this study indicate that PD with HBO could be used to increase the quality and the quantity of the bone newly formed by PD.

Lidocaine concentration in mandibular bone after subperiosteal infiltration anesthesia decreases with elevation of periosteal flap and irrigation with saline.

It has been reported that the action of infiltration anesthesia on the jawbone is attenuated significantly by elevation of the periosteal flap with saline irrigation in clinical studies; however, the reason is unclear. Therefore, the lidocaine concentration in mandibular bone after subperiosteal infiltration anesthesia was measured under several surgical conditions. The subjects were 48 rabbits. Infiltration anesthesia by 0.5 mL of 2% lidocaine with 1 : 80,000 epinephrine (adrenaline) was injected into the right mandibular angle and left mandibular body, respectively. Under several surgical conditions (presence or absence of periosteal flap, and presence or absence of saline irrigation), both mandibular bone samples were removed at a fixed time after subperiosteal infiltration anesthesia. The lidocaine concentration in each mandibular bone sample was measured by high-performance liquid chromatography. As a result, elevation of the periosteal flap with saline irrigation significantly decreased the lidocaine concentration in the mandibular bone. It is suggested that the anesthetic in the bone was washed out by saline irrigation. Therefore, supplemental conduction and/or general anesthesia should be utilized for long operations that include elevation of the periosteal flap with saline irrigation.

Tratamento cirúrgico da paquidermoperiostose primária - relato de dois casos / Surgical Treatment of Primary Pachydermoperiostosis: Report of Two Cases / Surgical Treatment of Primary Pachydermoperiostosis: Report of Two Cases

A paquidermoperiostose primária é uma doença rara, caracterizada por aposição excessiva do periósteo do crânio, coexistindo com espessamento da epiderme e derme (paquidermia), provocando deformidades grosseiras. Devido à diversidade de estruturas acometidas, há várias opções cirúrgicas e métodos complementares que são utilizados no tratamento das alterações faciais desses pacientes. Esse trabalho apresenta o lifting subperiosteal como uma opção de tratamento estético para a face de pacientes portadores dessa síndrome, através do relato de dois casos operados no Hospital das Clínicas da Universidade Federal de Minas Gerais.

Primary pachydermoperiostosis is a rare disease characterized by excessive skull affixing of the periosteum, coexisting with thickening of the epidermis and dermis (pachydermia), thereby causing gross deformities. Owing to the variety of affected structures, there are several surgical options and complementary methods that are used in the treatment of facial alterations in these patients. This report describes the use of subperiosteal detachment as an aesthetic treatment option for the faces of two patients with primary pachydermoperiostosis, operated at the Hospital das Clínicas of the Federal University of Minas Gerais.

[Assessment of quality in day-case hand surgery]. / Démarche d'assurance qualité en chirurgie ambulatoire de la main.

OBJECTIVE: To determine the level of satisfaction in terms of pain relief and comfort among patients receiving different postoperative analgesia protocols after hand surgery under regional anaesthesia in a day care unit. METHODS: Cohort study among patients after hand surgery under regional anaesthesia during two consecutive three months time periods, with patient stratification according to the expected pain level with different balanced analgesia protocols (group A: carpal tunnel, group B: other surgery without bone involvement, group C: bone surgery). A telephone survey, scoring analgesia and comfort, each with a numerical (0-10) scale was conducted on days 1 and 7. During the first period analgesia for groups A and B was the same (acetaminophen-dextropropoxyphene or acetaminophen-codeine) and group C patients were treated with acetaminophen-ketoprofen-tramadol. In the second period analgesia was reduced for group A (acetaminophen alone) and increased for group B (acetaminophen-ketoprofen-tramadol) and group C (duration increased from 3 to 7 days). RESULTS: For carpal tunnel surgery, analgesia with acetaminophen alone was efficient, (Pain scale [PS] d0=2[0-10], PS d1=1 [0-10] and PS d2-d4=0,5 [0-10]). This surgery does not elicit important pain, there is no benefit in adding other analgesics. For group B, a significant improvement in postoperative pain was observed (postoperative d1 p<0.03) with a major increase in side effects (2/57 vs 17/48 p<0.001). For group C, therapeutic changes were ineffective (PS d0=2 vs 3.5 et PS d1=3 vs 5 [NS]) and we noticed an increase in side effects (p<0.05). One third of all patients are totally satisfied on day 7, logistic regression showing the role of inefficient analgesia in late postoperative period (PS>2 between d2-d4). Between day 1 and day 7, 20% of the patients change their point of view, those who feel less satisfied on day 7 complained of a more severe postoperative pain between day 2 and 4 (p<0.001) and between day 5-7 (p<0.01). CONCLUSION: For hand surgery on day case, quality of late postoperative analgesia (day 2-day 7) is strongly related to patient's satisfaction on day 7.

Elevation of a periosteal flap with irrigation of the bone for minor oral surgery reduces the duration of action of infiltration anesthesia.

The aim of this study is to assess the difference in duration of action after infiltration anesthesia when elevation of a periosteal flap (EPF) was accomplished with water or saline irrigation versus nonelevation of a periosteal flap (NEPF). The 57 patients in this study were under conscious sedation. A long treatment time of more than 1 hour was used. Instances where peripheral nerve block or opioids were administered and infiltration anesthesia over 2 fields were excluded before the study. Patients were included in either an EPF group (n = 29) or an NEPF group (n = 28). Statistically significant differences were detected in the initial dose of anesthetic (EPF: 4.3 +/- 1.4 mL, NEPF: 1.8 +/- 0.9 mL), the time until initial supplemental anesthesia (EPF: 38 +/- 26 minutes, NEPF: 65 +/- 27 minutes), and the frequency of anesthesia administration (EPF: 2.5 +/- 1.2 times, NEPF: 1.3 +/- 0.7 times). These results suggest that the duration of anesthesia action in EPF decreases to half compared with NEPF, even if the anesthetic was infiltrated in double the amount. Although supplemental anesthesia is required frequently in EPF, it is not efficacious. We speculated that the residual anesthetics in tissue were washed out by irrigation and hemorrhage and that supplemental anesthesia became ineffective because of leakage from the opened flap. Elevation of a periosteal flap reduces the effect of infiltration anesthetics.

Differences in mandibular distraction osteogenesis after corticotomy and osteotomy.

Corticotomy or osteotomy was performed on opposing sides of the mandibles in 18 goats. A custom-made distractor was used to lengthen the mandible at a rate of 1 mm/day for 10 days (total 10 mm elongation). Six goats were sacrificed respectively at 2, 4 and 8 weeks after completion of distraction. The distracted calluses were harvested and processed for radiographic, histologic, and scanning electron microscopic evaluation as well as Ca/P ratio analysis. The regenerate bone in the corticotomy side showed more bone formation and earlier mineralization than in the osteotomy side. The results of this study suggest that preservation of intramedullary vessels is beneficial to bone regeneration following mandibular osteodistraction, and that performing corticotomy may be a simple but effective way to promote the maturity of the distracted callus and shorten the time for fixation.

Onlay silicone and hydroxyapatite-tricalciumphosphate composite (HAP-TCP) blocks interfere with nasal bone growth in rabbits.

We investigated how a new type of synthetic porous hydroxyapatite ceramic (HAP-TCP) acts when it is implanted in growing membranous bone. Seventy-six New Zealand White infant male rabbits (4-week-olds) were used. Rabbits received HAP-TCP block or silicone block implantation in their right nasal bone. The left nasal bone was used for a sham. Serial or cross-sectional examinations by morphometry, radiology, blood biochemistry, and histology were carried out. Both the HAP-TCP and silicone groups exhibited no systemic growth disturbance in terms of morphometry and blood biochemistry. Dual energy x-ray absorptiometry (DEXA) revealed, however, a decrease in the bone mineral content (BMC) of the right nasal bone in the silicone group. Histology revealed a superior affinity of HAP-TCP to bone tissue than that of silicone. When a HAP-TCP block was implanted under the periosteum it bonded directly to bone tissue. However, sinking of the implants into the bone tissue were noted both in the HAP-TCP and the silicone groups in longitudinal observation. These results suggest that although HAP-TCP has superior affinity to bone tissue, this by itself is not enough sufficient reason to believe that HAP-TCP can be effectively applied during the growth period.