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Biomedical subjects

E K Chao

Publications and source records attributed to E K Chao.

13 recordsLinked to original sources
PubMed1999

Osteosynthesis of carpal scaphoid nonunion with interpositional bone graft and Kirschner wires: a 3- to 6-year follow-up.

BACKGROUND: Malreduced or neglected unstable carpal scaphoid fractures may lead to nonunion, which is often difficult to treat and carries the risk of carpal instability and degenerative arthrosis. Here, we describe a new "sandwich" method, which takes advantage of minimal dissection and has promising results. METHODS: From 1989 through 1992, we treated 39 patients with scaphoid nonunion by using the sandwich method that consisted of a wedge corticocancellous strut graft and numerous cancellous bone chips. Divergent Kirschner wires were used for fixation of reduction. We retrospectively review 26 scaphoids with follow-up periods of 3 to 6 years. The functional outcome was evaluated with modification of the Mayo Wrist Scoring Chart. The radiographs were analyzed, and tomographs were used for confirmation of osseous union. RESULTS: All 26 scaphoids united within 4 months. The carpal instability and humpback deformity were corrected. In all cases, the functional results were either good or excellent. CONCLUSION: Interpositional bone grafts corrected scaphoid angulation and length. Divergent multiple pinning rather than screws avoids unwanted shearing and rotational force during application and provides stable fixation with minimal dissection. Most of scaphoid nonunions in our series were the oblique type in which the lag screw never created perfect compression because of a shearing force.

Adolescent↗
PubMed1999

Development of a biodegradable antibiotic delivery system.

Antibiotic beads have been used as a drug delivery system for the treatment of various surgical infections. In this study, the copolymer 50:50 poly(DL-lactide):co-glycolide was mixed with vancomycin powder and hot compressing molded at 55 degrees C to form five types of biodegradable antibiotic beads. The beads were placed in 1 mL of phosphate buffered saline and incubated at 37 degrees C. The phosphate buffered saline was changed daily, and the removed buffer solutions were stored at -70 degrees C until the antibiotic concentration in each sample was determined by high performance liquid chromatography system assay. The concentration of vancomycin in each sample was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for more than 32 days. The release was most marked during the first 48 hours. All copolymer 50:50 poly(DI lactide):co-glycolide biodegradable beads released high concentrations of the antibiotics in vitro for the time needed to treat bone infections (4 to 6 weeks). The diameter of the sample inhibition zone ranged from 6.5 mm to 10 mm, and the relative activity of vancomycin ranged from 12.5% to 100%. Copolymers with low heat of formation temperatures are required for making a controlled release system to prevent antibiotic decomposition, which occurs when using the hot compressing molded method. The rate and duration of release from the antibiotic beads can be adjusted by varying the diameter of the beads. This offers a convenient method to adjust the release rate to meet the specific antibiotic requirements for different patients.

Absorbable Implants↗
PubMed1998

Management of small infected tibial defects with antibiotic-impregnated autogenic cancellous bone grafting.

Between January of 1991 and December of 1993, 36 patients who had tibia fractures complicated by small infected tibia defects were treated at the authors' service. The group included 30 men and 6 women whose average age was 36.5 years (range, 18-72 years). The average follow-up period was 3.7 years. By using the Cierney-Mader staging classification of chronic osteomyelitis, 26 of 36 patients (72%) were stage 4A and 10 of 36 patients (28%) were stage 4B. Ten patients required muscle transfer. All patients were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate bead chains were used to obliterate the debrided osseous defect. In the second stage, the beads were removed, and the defects were reconstructed with antibiotic-impregnated autogenic cancellous bone graft. The time between the first and second stage was 2 to 8 weeks for patients without muscle transfer and 8 to 12 weeks for the patients with muscle transfer. The bone defects ranged from 2 to 4 cm. Wound healing and bony union were achieved in all patients. Only two patients had recurrent infections. The infection arrest rate was 94.4%. Minor pin tract infection of the external skeletal fixation was seen in two patients. Two patients developed skin rashes secondary to antibiotic therapy. Radiographs at an average follow-up of 3.7 years showed good consolidation and hypertrophy of grafted bones in all patients. After 3 to 5 years of follow-up, our results suggest that the use of impregnating antibiotics have no adverse effects on autogenic cancellous bone graft incorporation and may help to eliminate infection. This treatment protocol provided rapid recovery from osteomyelitis. The use of antibiotic-impregnated autogenic bone graft seems to be an effective and safe method for the management of small infected tibial defects.

Adolescent↗
PubMed1998

Closed management and percutaneous fixation of unstable proximal humerus fractures.

BACKGROUND: In dealing with displaced proximal humerus fractures, there is still much controversy in treatment modalities. The latest investigations emphasize the concept of minimal exposure and rigid fixation. METHODS: The technique of closed reduction and percutaneous fixation with cannulated screws and k-pins was performed on 19 patients with two- and three-part proximal humerus fractures. The outcomes were evaluated with a mean follow-up of 21 months. RESULTS: All except one case had a solid union of the fracture. Sixteen of 19 patients (84%) acquired good or excellent results according to Neer's classification. No further collapse or avascular necrosis was found. CONCLUSION: The method of closed reduction and percutaneous fixation, although technically demanding, yields satisfactory results in displaced proximal humerus fracture. Cannulated screws provided rigid fixation that was the underlying tenet for early functional retrieval.

Adolescent↗
PubMed1998

Chronic refractory tibia osteomyelitis treated with adjuvent hyperbaric oxygen: a preliminary report.

BACKGROUND: Refractory osteomyelitis is a serious disease that fails to respond to aggressive medical and surgical treatment. A plethora of alternative therapies have evolved. Hyperbaric oxygen has been proven to enhance bone and soft tissue healing in many in vitro and in vivo studies. This article presents the preliminary results of adjunctive hyperbaric oxygen therapy in patients with refractory osteomyelitis. MATERIALS AND METHODS: Fifteen patients who were diagnosed with refractory tibia osteomyelitis were treated prospectively with adjunctive hyperbaric oxygen therapy, aggressive surgical debridement, and parenteral antibiotic treatment. The effectiveness was evaluated with an average follow-up of 17.2 months. RESULTS: The hyperbaric oxygen therapy averaged 26 daily sessions. Successful treatment was achieved in 13 patients (86%). The mean length of treatment was 45 days. The preliminary results are comparable with other series. CONCLUSION: Hyperbaric oxygen is effective as an adjunct to aggressive medical and surgical management in refractory osteomyelitis. A precise clinical staging system for patient selection and treatment organization is imperative to successful outcome.

Adolescent↗
PubMed1997

Augmentative plate fixation for the management of femoral nonunion after intramedullary nailing.

Seventeen femoral nonunions after intramedullary nail internal fixation were treated with augmentative plate internal fixation. Six of them were initially managed with a Küntscher nail internal fixation; the other 11 fractures were managed with a locked nail internal fixation. All the femoral nonunions were caused by insecure fixation of the intramedullary nailing, in which a rotational instability of the fracture site was verified in all cases during operation. Leaving the intramedullary nail in situ, an augmentative plate fixation was applied to the fracture site to counter the rotational instability. A simultaneous bone grafting was performed in seven of them to repair the bony defect. All these patients walked bearing full weight on the extremity without aching at the fracture site within 3 months and all these 17 fractures obtained a bony union within an average of 7 months after this treatment. From our experience, we have found this method is a useful treatment for the nonunion of the femoral shaft fracture after an intramedullary nail internal fixation. The technique is simple and does not require any special instrument. It facilitates an early weight bearing and gives a quick recovery from nonunion.

Adolescent↗
PubMed1997

Hyperbaric oxygen in the treatment of diabetic foot infection.

BACKGROUND: Although hyperbaric oxygen therapy to treat diabetic foot lesions has been approved for insurance reimbursement in Taiwan, its clinical application has not yet been well accepted. This study evaluated multiple healing predictive factors in patients with diabetic foot infections to determine the usefulness of adjunctive hyperbaric oxygen in the treatment of such patients. METHODS: From March 1995 to May 1996, we treated 31 diabetic patients presenting with infected foot lesions with a regimen of adequate metabolic control, frequent wound debridement and hyperbaric oxygen therapy. Age, gender, leukocyte count, total lymphocyte count, hemoglobin, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), glycosylated hemoglobin Alc (HbAlc), albumin, ankle-brachial index, types of bacterial cultures and number of debridements were compared between successful and failed treatments. Independent t-test and Fisher's exact test were used to identify the prognostic factors associated with outcome of treatment. RESULTS: The mean age of the patients was 63.0 +/- 9.7 years (range 43 to 81). The mean number of hyperbaric oxygen therapies was 35.3 +/- 21.8 treatments (range 5 to 83). Of the 31 patients, 6 received below knee amputation, and 25 had their foot preserved or achieved a lower level of amputation. Elevated leukocyte count and low ankle-brachial index were significantly related to poor outcome. CONCLUSIONS: In the treatment of diabetic foot infection, adjunctive hyperbaric oxygen therapy seems to be a useful tool to enhance wound healing provided that there are preserved circulation and controlled infection.

Adult↗
PubMed1996

Staphylococcal pyomyositis.

Pyomyositis, a suppurative infection of the skeletal muscle, is uncommon and frequently misdiagnosed. Staphylococcus aureus has been reported as the most common causative organism in the tropics. The purposes of this study were to examine the clinical courses including presentations, treatments, and final outcomes of Staphylococcal pymyositis in Chang Gung Memorial Hospital and to suggest a treatment modality for this disorder. From July 1985 to June 1994, 12 patients were treated in this hospital for Staphylococcal pyomyositis. There were 9 males and 3 females, whose mean age was 22.1 years. The involved patients were either in the first two or in the fifth to seventh decades of life. Fever was found in all of them. The average time lag in diagnosis was 11.8 days from the onset of minor symptoms. The Gallium-67 scan was very sensitive and valuable in localization of the disease. Debridement or surgical drainage of the abscess was done in 11 patients. All the patients recovered after between 4 and 6 weeks of adequate antibiotic treatment without major abnormalities and complications. In summary, Staphylococcal pyomyositis is a rather benign disease. However, diagnosis is often delayed due to its vague presentation and lack of clinical suspicion. Unfamiliarity with this disease may be an obstacle to appropriate management.

Adolescent↗
PubMed1996

Augmentation of elbow stability with radial head transfer: a case report and review of the literature.

A case of neglected elbow dislocation having a late open reduction is presented and the literature reviewed. While the functional result is inversely related to the interval between injury and the time of operation, stability and early motion are two keys for good functional recovery. A new method of coronoid process reconstruction is presented as a suggestion for augmentation of elbow stability in patients with irreducible dislocation and stage III instability. A functional range of motion is achieved under immediate protected flexion-extension exercise after concentric reduction and secure reconstruction.

Adult↗
PubMed1995

Complete fracture-dislocation of the thoracic spine with spontaneous neurologic decompression: a case report.

Fracture-dislocations of the thoracic spine without spinal cord injury are very rare. We report a case of a complete T6-7 fracture-dislocation without neurologic deficit in a 61-year-old male Taiwanese. Complicating neurological deterioration on the fifth post-injury day during a nonoperative treatment with a Gardner-Wells skull tong and pelvic belt traction on a Stryker frame was noted. Emergent open reduction and posterior instrumentation with dual Harrington rods of T3 to T9 was performed. At 2-year follow-up examination, a good reduction was maintained and the patient had resumed full activities.

Humans↗
PubMed1990

Post-traumatic fat embolism syndrome--a 10 year retrospective study in Chang Gung Memorial Hospital.

Forty patients with post-traumatic fat embolism syndrome (FES) from January 1977 through December 1986 were retrospectively analyzed. Diagnosis was made according to the criteria modified by Guard. All 40 patients had at least two major criteria, namely change in consciousness and hypoxia. Twenty patients (50%) presented with full-blown clinical features. Prompt respiratory support with oxygen mask or nasal prongs was the first line of treatment. Forty per cent of patients responded well, whereas the others had to be advanced to endotracheal intubation and mechanical ventilation with positive end expiratory pressure. Steroids were given to 80% of patients and better results were achieved than in the group not treated with steroids. The mortality rate was low (2.5%) and only four patients suffered prolonged cerebral sequelae. The clinical course and prognosis cannot be predicted from the severity of the fracture.

Adolescent↗
PubMed1989

Fracture of the hook of the hamate.

We removed the fracture fragment from fifty-nine patients who had an isolated fracture of the hook of the hamate. Preoperatively, all had complained of pain and tenderness on the ulnar side of the palm or on the dorsal ulnar aspect of the wrist. Most fractures were thought to have occurred while the patient was swinging a racquet, golf club, or baseball bat. Some fractures were caused by striking the palm on a solid object, by falling on the palm, or by a crush injury to the hand. Most of the fractures were diagnosed conclusively on a carpal tunnel roentgenogram or on a special oblique roentgenogram of the wrist supinated. We now believe that computed axial tomography is the best imaging technique for demonstrating this fracture. Except for two patients who had a crush injury, all of the patients returned to their regular occupational and athletic pursuits. There were no surgical complications.

Adult↗