Efficacy of vancomycin-releasing biodegradable poly(lactide-co-glycolide) antibiotics beads for treatment of experimental bone infection due to Staphylococcus aureus.

BACKGROUND: Clinical experience and animal studies have suggested that positron emission tomography (PET) using fluorine-18-labeled fluorodeoxyglucose ((18)F-FDG) may be promising for imaging of bone infections. In this study, we aimed to establish the accuracy of (18)F-FDG PET scanning for monitoring the response to poly(lactide-co-glycolide) (PLGA) vancomycin beads for treatment of bone infection. METHODS: PLGA was mixed with vancomycin and hot-compress molded to form antibiotic beads. In vitro, elution assays and bacterial inhibition tests were employed to characterize the released antibiotics. In vivo, cylindrical cavities were made in six adult male New Zealand white rabbits, and Staphylococcus aureus or saline was injected into the cavity to create a bone infection. After 2 weeks, the infection was confirmed by bacterial cultures, and the defect was filled with PLGA vancomycin beads. The treatment response was monitored by (18)F-FDG PET. RESULTS: The biodegradable beads released high concentrations of vancomycin (well above the breakpoint sensitivity concentration) for treatment of bone infection. In bacterial inhibition tests, the diameter of the sample inhibition zone ranged from 6.5 to 10 mm, which was equivalent to 12.5-100 % relative activity. (18)F-FDG PET results showed that uncomplicated bone healing was associated with a temporary increase in (18)F-FDG uptake at 2 weeks, with return to near baseline at 6 weeks. In the infected animals, localized infection resulted in intense continuous uptake of (18)F-FDG, which was higher than that in uncomplicated healing bones. Bone infection was confirmed with positive bacterial cultures. In vancomycin-treated animals, data showed rapidly decreasing amounts of (18)F-FDG uptake after treatment. CONCLUSIONS: In vitro and in vivo analyses showed that the use of biodegradable PLGA vancomycin beads successfully eradicated S. aureus infection in damaged bone.

Exposure of Prebiopsy Antibiotics Influence Bacteriological Diagnosis and Clinical Outcomes in Patients With Infectious Spondylitis.

The benefit of prebiopsy empirical antibiotics for patients with infectious spondylitis and the effect on clinical outcome are not well known. This study assessed the impact of prebiopsy empirical antibiotics in patients with infectious spondylitis. We retrospectively reviewed 41 adult in-patients with infectious spondylitis who received percutaneous endoscopic debridement and drainage (PEDD) at a tertiary care hospital from August 2002 to August 2012. The average patient age was 55.2 years old and causative bacteria were identified in 32 out of 41 biopsy specimens (78.0%) via the PEDD procedure, which has good diagnostic efficacy comparable to open biopsy. Seventeen patients (41.5%) received prebiopsy empirical antimicrobial therapy, and these patients were less likely to have positive cultures than those who did not receive preoperative antibiotics (64.7% vs 87.5%, P = 0.04). Patients with positive cultures had a better infection control rate (78.1% vs 67.7%) and were less likely to undergo subsequent open surgery. Patients given preoperative antibiotics were more likely to need subsequent open surgery (35.3% vs 16.7%, P = 0.02). From multivariate logistic analysis showed age at diagnosis to be an independent risk factor for the need of further surgery. There were no major complications following the PEDD procedure, except 2 patients had transient paresthesia in the affected lumbar segments. Prebiopsy empirical antibiotic therapy was associated with lower positive culture rate and an increased need for subsequent open surgery. Patients with positive cultures were more likely to have initially adequate treatment, better infection control, and better clinical outcome.

The fusion rate of demineralized bone matrix compared with autogenous iliac bone graft for long multi-segment posterolateral spinal fusion.

BACKGROUND: Although autogenous iliac bone graft (AIBG) remains the gold standard for spine fusion, harvesting morbidity has prompted the search for alternatives especially for multi-segment fusion. This study aimed to evaluate the efficacy of using demineralized bone matrix (DBM) as a substitute of AIBG for long instrumented posterolateral fusion (≧ three-level fusion). METHODS: A total of 47 consecutive patients underwent laminectomy decompression, and multi-level instrumented posterolateral fusions were reviewed. Group 1 comprised 26 patients having DBM with autologous laminectomy bone (ALB). Group 2 consisted of 21 patients having AIBG with ALB. The fusion success evaluation was based on findings using the 12-month anteroposterior and dynamic plain radiographs. RESULTS: Gender, age, and the number of fusion levels were similar for both groups. 21 of 26 (80.8%) patients in group 1 and 18 of 21 (85.7%) patients in group 2 were observed to achieve solid bony fusion. There was no statistical difference in the fusion success (p = 0.72). Blood loss was significantly more in group 2 (p = 0.02). The duration of the hospital stays and operative times being longer for group 2, but the difference was not significant. CONCLUSIONS: DBM combined with ALB and osteoconductive materials is as effective as an autologous iliac bone graft with respect to long multi-segment posterolateral fusion success. DBM can be used as an effective bone graft substitute and may decrease morbidities associated with iliac bone graft harvest.

Evaluating Osteogenic Potential of Ligamentum Flavum Cells Cultivated in Photoresponsive Hydrogel that Incorporates Bone Morphogenetic Protein-2 for Spinal Fusion.

Regenerative medicine is increasingly important in clinical practice. Ligamentum flava (LF) are typically removed during spine-related surgeries. LF may be a source of cells for spinal fusion that is conducted using tissue engineering techniques. In this investigation, LF cells of rabbits were isolated and then characterized by flow cytometry, morphological observation, and immunofluorescence staining. The LF cells were also cultivated in polyethylene (glycol) diacrylate (PEGDA) hydrogels that incorporated bone morphogenetic protein-2 (BMP-2) growth factor, to evaluate their proliferation and secretion of ECM and differentiation in vitro. The experimental results thus obtained that the proliferation, ECM secretion, and differentiation of the PEGDA-BMP-2 group exceeded those of the PEGDA group during the period of cultivation. The mineralization and histological staining results differed similarly. A nude mice model was utilized to prove that LF cells on hydrogels could undergo osteogenic differentiation in vivo. These experimental results also revealed that the PEGDA-BMP-2 group had better osteogenic effects than the PEGDA group following a 12 weeks after transplantation. According to all of these experimental results, LF cells are a source of cells for spinal fusion and PEGDA-BMP-2 hydrogel is a candidate biomaterial for spinal fusion by tissue engineering.

Mesenchymal stem cells expressing baculovirus-engineered BMP-2 and VEGF enhance posterolateral spine fusion in a rabbit model.

BACKGROUND CONTEXT: Mesenchymal stem cell (MSC)-based cell therapy and gene transfer have converged and show great potential for accelerating bone healing. Gene therapy can provide more sustained expression of osteogenic factors such as bone morphogenetic protein-2 (BMP-2). We previously demonstrated that low-dose BMP-2 enhanced spinal posterolateral fusion by MSCs in a rabbit model. Herein, we genetically modified rabbit MSCs with a recombinant baculovirus encoding BMP-2 (Bac-CB) and vascular endothelial growth factor (Bac-VEGF) seeded into porous scaffolds to enhance spinal fusion. PURPOSE: This study evaluates the success rate of the MSC-based cell therapy and gene transfer approach for single-level posterolateral spine fusion. We hypothesize that combining three-dimensional tricalcium phosphate (TCP) scaffolds and genetically modified allogeneic MSCs with baculovirus-mediated growth factor expression would increase the success rate of spinal fusion. STUDY DESIGN: The study design was based on an animal model (approved by the Institutional Animal Care and Use Committee) using 18 adult male New Zealand rabbits. METHODS: This study included 18 male New Zealand rabbits, weighing 3.5 to 4 kg. Allogeneic bone marrow-derived MSCs were isolated and genetically modified with Bac-CB and Bac-CV seeded onto TCP scaffolds (MSC/Bac/TCP). The animals were divided into three groups according to the material implanted into the bilateral L4-L5 intertransverse space: TCP scaffold (n=6), MSC/TCP (n=6), and MSC/Bac/TCP (n=6). After 12 weeks, the rabbits were euthanized for radiographic examination, manual palpation, and histologic study. RESULTS: Bilateral fusion areas in each animal were evaluated independently. The radiographic fusion rates at 12 sites were 0 of 12 in the TCP scaffold group, 4 of 12 in the MSC/TCP group, and 10 of 12 in the MSC/Bac/TCP group. By manual palpation, there were zero solid fusions in the TCP scaffold group, two solid fusions in the MSC/TCP group, and five solid fusions in the MSC/Bac/TCP group. Fusion rates were significantly greater in the MSC/Bac/TCP group. CONCLUSIONS: The results indicate the potential of using baculovirus as a vector for gene/cell therapy approaches to improve bone healing and support the feasibility of using allogeneic MSCs for inducing bone formation and intertransverse process fusion.

Hyperbaric oxygen treatment prevents nitric oxide-induced apoptosis in articular cartilage injury via enhancement of the expression of heat shock protein 70.

Heat shock proteins (HSPs), inflammatory cytokines, nitric oxide (NO), and localized hypoxia-induced apoptosis are thought to be correlated to the degree of cartilage injury. We investigated the effect of hyperbaric oxygen (HBO) on (1) interleukin-1ß (IL-1ß)-induced NO production and apoptosis of rabbit chondrocytes and (2) healing of articular cartilage defects. For the in vitro study, RT-PCR and Western blotting were performed to detect mRNA and protein expressions of HSP70, inducible NO synthase (iNOS), and caspase 3 in IL-1ß-treated chondrocytes. To clarify that the HSP70 was necessary for anti-iNOS and anti-apoptotic activity by HBO, we treated the cells with an HSP70 inhibitor, KNK437. For the in vivo study, cartilage defects were created in rabbits. The HBO group was exposed to 100% oxygen at 2.5 ATA for 1.5 h a day for 10 weeks. The control group was exposed to normal air. After sacrifice, specimen sections were sent for examination using a scoring system. Immunohistochemical analyses were performed to detect the expressions of iNOS, HSP70, and caspase 3. Our results suggested that HBO upregulated the mRNA and protein expressions of HSP70 and suppressed those of iNOS and caspase 3 in chondrocytes. KNK437 inhibited the HBO-induced downregulation of iNOS and casapase 3 activities. The histological scores showed that HBO markedly enhanced cartilage repair. Immunohistostaining showed that HBO enhanced HSP70 expression and suppressed iNOS and caspase 3 expressions in chondrocytes. Accordingly, HBO treatment prevents NO-induced apoptosis in articular cartilage injury via enhancement of the expression of heat shock protein 70.

Hyperbaric oxygen treatment suppresses MAPK signaling and mitochondrial apoptotic pathway in degenerated human intervertebral disc cells.

Nucleus pulposus cells (NPCs) from degenerating discs produce catabolic and inflammatory factors, including interleukin (IL)-1 and nitric oxide (NO). Enhanced production of NO has been implicated in the apoptosis of degenerating disc cells. This study evaluates the effects of hyperbaric oxygen (HBO) on degenerated human NPCs. All hyperoxic cells were exposed to 100% O(2) at 2.5 atmospheres absolute (ATA). Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) in NPCs was detected using the phosphor-kinase array kit. RNA was isolated for real-time polymerase chain reaction (PCR) analysis of aggrecan and type II collagen gene expression. The levels of IL- 1ß and NO were quantified by enzyme-linked immunosorbent assay (ELISA). To identify the HBO-induced anti-apoptotic pathways, expression of Bcl-2 and Bax proteins as well as activation of cysteine-containing aspartate-specific proteases (caspases) 3, 8, and 9 was evaluated using Western blotting after HBO treatment. Our data showed that HBO treatment decreased the expression of IL-1ß, suppressed phosphorylation of ERK1/2, JNK, and p38 MAPK, decreased synthesis of NO, and increased the gene expression of aggrecan and type II collagen in NPCs as compared with the atmospheric treatment. HBO up-regulated the ratio of Bcl-2 to Bax expression and reduced the activity of caspases 9 and 3 but not of caspase 8, indicating a selective effect over the mitochondrial apoptosis pathway in degenerated NPCs. These results support our hypothesis that HBO treatment suppresses MAPK signaling and mitochondrial apoptotic pathway in degenerated human intervertebral disc cells.

Effect of hyperbaric oxygenation on intervertebral disc degeneration: an in vivo study with sprague-dawley rats.

STUDY DESIGN: An in vivo study was conducted to test the effect of hyperbaric oxygenation (HBO) on intervertebral disc degeneration in Sprague-Dawley rats. OBJECTIVE: To observe the changes in intervertebral disc height and levels of glycosaminoglycan, collagen, interleukin-1ß (IL-1ß), prostaglandin E2 (PGE2), and inducible nitric oxide synthase (iNOS) in degenerated intervertebral discs after HBO therapy. SUMMARY OF BACKGROUND DATA: Although the involvement of IL-1ß, PGE-2, NO, and low O2 concentration has been demonstrated in intervertebral disc degeneration, the actual mechanism is not clear. It has been reported that HBO influences changes in IL-1ß, PGE-2, NO, and O2 concentration. Previously, a study demonstrated an in vitro positive effect of HBO on the human nucleus pulposus. Thus, an in vivo study in animals was necessary. METHODS: Twelve Sprague-Dawley rats were each injected with chondroitinase ABC in 2 proximal intervertebral discs of the tail. After treating with 100% oxygen at 2.5 atmospheres 2 hours per days for 10 days, the change in disc height was determined by radiography. The amounts of PGE-2, iNOS, glycosaminoglycan, and total collagen in the intervertebral disc were quantified by enzyme-linked immunosorbent assay. Tissue morphology and the distribution of glycosaminoglycan, IL-1ß, and iNOS in the intervertebral disc were assessed by histology and immunohistochemistry. The area of IL-1ß in the intervertebral discs was quantified using image analysis software. RESULTS: HBO therapy stopped the decrease in intervertebral disc height, caused an increase in the amount of glycosaminoglycan, and inhibited IL-1ß, PGE-2, and iNOS production. CONCLUSION: HBO provides a potential treatment modality for intervertebral disc degeneration.

Classification and analysis of pathology of the long head of the biceps tendon in complete rotator cuff tears.

BACKGROUND: Pathology of the long head of the biceps tendon (LHB) is commonly associated with rotator cuff tears (RCTs). Superior labral anterior-posterior (SLAP) lesions can also occur with RCTs. The purpose of this study was to include SLAP lesions as part of LHB pathology in surgical cases of RCT and define the role of SLAP lesions in RCTs. METHODS: We retrospectively evaluated clinical data from 176 cases of complete RCT undergoing surgery. During surgery, the LHB was arthroscopically examined. A modified 6-type classification was used to describe the LHB pathology in these cases: tendinitis, subluxation, dislocation, partial tear, complete rupture and SLAP lesions. The relationship of LHB pathology to different characteristics of RCTs was statistically analyzed. RESULTS: Of RCT cases, 33% had Type 1 (tendinitis), 11% had Type 2 (subluxation), 9% had Type 3 (dislocation), 16% had Type 4 (partial tear), 7% had Type 5 (complete rupture) and 6% had Type 6 (SLAP) lesions. The remaining 18% of cases had no obvious LHB pathology. LHB pathology were associated with RCTs of a long duration (> 3 months), large area (> 5 cm(2)), and multiple or subscapularis tendon involvement. Seventy four percent of patients with affected shoulders underwent simultaneous surgery for both LHB pathology and RCTs. CONCLUSION: Most patient with RCTs with chronic, massive, and multiple or subscapularis tendon involvement also had LHB injury. SLAP lesions, which we classified as a subgroup of LHB pathology, should be identified during rotator cuff surgery and treated appropriately.

Enhancement of rotator cuff tendon-bone healing with injectable periosteum progenitor cells-BMP-2 hydrogel in vivo.

PURPOSE: The fixation and incorporation of ruptured rotator cuff tendon to bone is a major concern in rotator cuff repair surgery. Rotator cuff repair usually fails at the tendon-bone interface, especially in case of large or massive tears. To enhance tendon-bone healing, an injectable hydrogel made with periosteal progenitor cells(PPCs) and poly (ethylene glycol) diacrylate (PEGDA) tethered with bone morphogenic protein-2(BMP-2) was developed to encourage extracellular matrix synthesis for tendon-to-bone healing in rotator cuff repair. METHODS: The infraspinatus tendon was cut from the greater tuberosity and repaired through a transosseous tunnel with the injectable progenitor cell-BMP-2 hydrogel applied between the tendon-bone interface. The injectable hydrogel was prepared from 10% poly (ethylene glycol) diacrylate (PEGDA) containing 0.05% of the photoinitiator. BMP-2 tethered with poly(ethylene glycol) (PEG) was blended to the hydrogel. Rabbit periosteal progenitor cells (PPCs) isolated from periosteum were mixed with hydrogel and injected on the tendon-bone interface. Ultraviolet radiation (365 nm) was applied for 60 s to photopolymerize the injection and solidify the hydrogel. The rabbits were killed at 4 and 8 weeks. The morphological characteristics of the healing tendon-to-bone interface were evaluated by histological and immunohistochemical methods. The biomechanical test was done to determine healing attachment strength. RESULTS: At both the 4- and 8-week killing, histological analysis of the tendon-bone interface showed an increasing fibrocartilage and bone layer formed in the tendon-bone interface in PEGDA group. At 4 weeks, fibrocartilage-like tissue was observed in a focal area. At 8 weeks, further matrix deposition occurred with fibrocartilage formation in the tendon-bone junction, and bone formation appeared near host bone. Immunohistochemistry revealed the presence of aggrecan and type II collagen. Biomechanical testing revealed a higher maximum pull-out load at all time points with a statistically significant difference at 4 and 8 weeks postoperatively. CONCLUSION: PEGDA hydrogel was approved as an adequate matrix for the encapsulation of cells and signal factor, and as an effective local delivery method to the tendon-bone interface through injection and photopolymerization. The PPCs-BMP2-hydrogel provides a powerful inductive ability between the tendon and the bone and enhances tendon-bone healing through the neoformation of fibrocartilage.

Effect of hyperbaric oxygenation on intervertebral disc degeneration: an in vitro study with human lumbar nucleus pulposus.

STUDY DESIGN: An in vitro study with degenerated human lumbar intervertebral disc specimens cultured under hyperbaric oxygenation (HBO). OBJECTIVE: To observe the changes in interleukin (IL)-1ß, prostaglandin (PG)-E2, nitric oxide (NO), cell growth, and apoptosis of the human nucleus pulposus cell (NPC) after HBO. SUMMARY OF BACKGROUND DATA: Intervertebral disc degeneration has been demonstrated as related to IL-1ß, PG-E2, NO, and O2 concentration but the actual mechanism is not clear. HBO also has also been reported in the literature to influence changes in IL-1ß, prostaglandin E2, NO, and O2 concentration. However, the direct effect of HBO on the disc cells has not been previously reported. METHODS: We collected 12 human lumbar degenerated disc specimens and evaluated the effects of HBO on the cultured NPCs. The amounts of IL-1ß, PG-E2, and NO in the conditioned medium were quantified by enzyme-linked immunosorbent assay and high performance liquid chromatography. Cell growth was measured by increase in cell number. Cell viability and proteoglycan content were evaluated by histologic study using safranin O staining. In situ analysis of apoptosis was performed using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. RESULTS: Our data indicated that HBO treatment inhibited IL-1ß, PG-E2, and NO production but increased cell number and matrix synthesis of cultured NPCs. TUNEL staining showed that HBO treatment suppressed the apoptosis of cultured NPCs. CONCLUSION: HBO provides a potential treatment modality for disc degeneration.

Arthroscopic single-bundle anterior cruciate ligament reconstruction with periosteum-enveloping hamstring tendon graft: clinical outcome at 2 to 7 years.

PURPOSE: In this case-series outcome study, we present our surgical technique for single-bundle anterior cruciate ligament (ACL) reconstruction with periosteum-enveloping hamstring tendon graft at a minimum of 2 years' follow-up. METHODS: From 2000 to 2005, ACL reconstruction with a periosteum-enveloping hamstring tendon graft was performed in 368 patients (372 knees). Of those patients, 312 who completed at least 2 years of follow-up were included for analysis. Four-strand periosteum-enveloping hamstring tendon grafts were used for single-bundle reconstruction. Clinical assessments included the Lysholm knee score, International Knee Documentation Committee score, KT-1000 instrumented testing (MEDmetric, San Diego, CA), thigh muscle assessment, and radiographic evaluation. Radiographs were used to assess femoral and tibial tunnel widening. RESULTS: The 312 study patients were followed up for a mean of 4.6 years (range, 2 to 7 years). The median Lysholm knee scores were 56 points (range, 40 to 70 points) and 95 points (range, 60 to 100 points) before and after surgery, respectively. After reconstruction, 85% of patients could return to moderate or strenuous activity, 5.1% exhibited grade 2 or higher ligament laxity with the anterior drawer test, and 6.1% had a positive pivot shift. Complete range of motion was achieved in 88% of patients. On the basis of International Knee Documentation Committee assessment, 93% of patients had a normal or nearly normal rating. CONCLUSIONS: Satisfactory results can be achieved with the periosteum-enveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Treatment of volar Barton's fractures: comparison between two common surgical techniques.

BACKGROUND: Volar Barton's fractures are not uncommon but more convincing treatment methods are still controversial. Currently, open reduction with buttress plating or closed reduction with external fixation and percutaneous Kirschner wire fixation have achieved most support. METHODS: Twenty-three consecutive volar Barton's fractures treated with either open reduction and buttress plate fixation (12 cases) or closed reduction with external fixation and percutaneous Kirschner wire fixation (11 cases) were compared retrospectively. The fractures were followed-up for a mean of 30 months (range, 24-50 months). RESULTS: All 23 fractures healed without major complications. The wrist function was satisfactory in all plating patients (12 out of 12) and nine out of 11 external fixation patients (p = 0.22). CONCLUSION: Both the above mentioned surgical techniques give a high success rate. Despite the fact that each technique has advantages and disadvantages, the results from the plating treatment seem to be superior.

Subacromial injections of corticosteroids and xylocaine for painful subacromial impingement syndrome.

BACKGROUND: Subacromial impingement syndrome, with pain and limited motion, is a common disease encountered daily in clinics. This study determined the efficacy of subacromial injections of corticosteroids and local anesthesia for treatment of painful subacromial impingement syndrome. METHODS: A total of 238 shoulders in 209 patients, with regular follow-up, were enrolled in this study. Mean patient age was 51 years (range 31-72 years). Each patient complained of shoulder pain with progressive motion limitation present for more than one month, which was not relieved by various nonsurgical treatments. The mean duration of symptoms before injection was five months (range 1-12 months). Each patient had a positive Neer impingement sign, Hawkins impingement sign, painful tendon sign, limited range of motion and did not show clinical evidence of a rotator cuff tear. Each patient was administered an injection of 1 ml of 2% Xylocaine and 1 ml of Rinderon suspension. A second injection was administered one week later for patients without obvious improvement. Following injections, patients were instructed to perform a home rehabilitation program for four weeks. Follow-up examinations were scheduled for one, two and four weeks, and three, six, nine and 12 months after injection. Outcome measures included the Constant-Murley score and shoulder range of motion. RESULTS: At follow-up four weeks after the first injection, 216 shoulders (91%) had satisfactory improvement in amount of pain and range of motion: mean improvements in the active range of motion of forward elevation, abduction, internal rotation and external rotation were 56 degrees, 48 degrees, 18 degrees and 22 degrees, respectively. However, at the first year follow-up, the satisfaction rate was slightly down at 88%, and 19 shoulders (8%; 16 patients) had recurrent pain and motion limitation after an average of 5.4 months (range 3-12 months). Each of these patients received another injection. Surgery was recommended for 22 shoulders (9%; 18 patients) that did not have satisfactory improvement. Of these patients, eight shoulders (seven patients) had a partial tear of the rotator cuff and 10 shoulders (eight patients) had complete rotator cuff tears. CONCLUSION: Subacromial injection of corticosteroids and local anesthesia is an effective therapy for the treatment of symptomatic subacromial pathology, such as impingement pain, tendonitis and bursitis. The injection can substantially reduce pain and increase range of motion of the shoulder. If there is no improvement following injections, a rotator cuff tear should be suspected.

Closed femoral nailing in lateral decubitus position without a fracture table: a preliminary report of fifteen patients.

BACKGROUND: The use of a fracture table is standard for closed intramedullary nailing of femoral fractures. Instead of a fracture table, some clinicians have successfully performed this operation in the supine position via manual traction. Here, we present our experience performing this operation in the lateral decubitus position without a fracture table. METHODS: From December 2001 to November 2002, we consecutively performed closed intramedullary femoral nailing in 15 patients with low comminuted femoral shaft fractures in the lateral decubitus position without a fracture table. We used manual or joystick traction to approximate the fracture fragments and introduced a guide pin. A reaming procedure was done with serial reamers of increasing diameters to reduce the fracture fragments. Then, the nail was inserted along the guide pin. RESULTS: Six femora underwent Küntscher nailing and nine femora underwent interlocking nailing. Nine procedures were completed via joystick traction and six were completed via manual traction only. All fifteen procedures were completed without any changes in the other operative methods. The mean operation time was 55 minutes for Küntscher nailing and 118.3 minutes for interlocking nailing. The average union time was 5.8 months with 100% union. CONCLUSIONS: For low comminuted femoral shaft fractures, using manual or joystick traction in the lateral decubitus position without a fracture table is an alternative in closed femoral intramedullary nailing.

Early administration of hyperbaric oxygen therapy in distraction osteogenesis--a quantitative study in New Zealand rabbits.

BACKGROUND: We investigated the effect of hyperbaric oxygen (HBO) therapy on the early phase of tibial lengthening in our established rabbit model. METHODS: Twenty-four male rabbits (six per group) underwent right tibial lengthening by 5 mm. Group 1 then underwent 2.5 atmospheres of absolute hyperbaric oxygenation for 2 hours daily for 6 weeks postoperatively; group 2, for early 5 weeks (weeks 1-5), group 3, for late 5 weeks (weeks 2-6), and group 4 had no HBO therapy. Bone mineral density (BMD) was measured before surgery and weekly thereafter from weeks 2 through 6. The mechanical strengths of the lengthened tibias were measured. RESULTS: Significantly higher mean %BMDs were obtained for groups 1 and 2 compared with groups 3 and 4. There was no difference in the mean %BMD between groups 1 and 2 (p > 0.05). The results were similar for mean percentage maximal torque; group 1 had the maximum torque, followed sequentially by groups 2 though 4. CONCLUSION: The study results suggest that early and full-term administration of HBO therapy on tibial lengthening may achieve better benefits.