Biomedical subjects

K Y Chiu

Publications and source records attributed to K Y Chiu.

At least 55 records · Page 3Linked to original sources

PubMed2001

Review Article: Polyethylene wear and osteolysis in total hip arthroplasty.

Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty. Submicron particles, which are secondary to abrasive wear, migrate into the effective joint space and stimulate a foreign-body response resulting in bone loss which is mainly mediated by macrophages. Diagnosis depends on serial radiographic evaluation and frequent follow-up. Polyethylene wear and osteolysis can be prevented by reducing the wear such as using a small femoral head, adaptive polyethylene thickness, suitable surgical techniques, non-polyethylene articulation, etc. The presence of cement or circumferential coatings may also retard the distal migration of particles. Medicines such as NSAIDs and bisphosphonate appear to inhibit the progress of osteolysis. As far as treatment, revision surgery is able to reconstruct the joint by replacing partial or total prosthesis and repair the defect by bone grafting according to intraoperative assessment.

Journal Article↗

PubMed2001

Renal cell carcinoma metastasized to the ureteral stump.

A rare case of ureteral stump metastasis 3 months after nephrectomy for a renal cell carcinoma is presented. A 62-year-old female had undergone right radical nephrectomy 3 months earlier because of renal cell carcinoma in our hospital, and she came back due to gross hematuria. Cystoscopy revealed a papillary mass with a vascular pedicle protruding from the right ureteral orifice. Transurethral resection of the bladder tumor over right ureteral orifice was performed and the pathologic result showed clear cell adenocarcinoma, which argued in favor of a metastatic lesion from the previous renal cell carcinoma. Ureterectomy and a bladder cuff excision were then adopted for this patient, but no residual tumor was found over the remaining ureter. Nevertheless, the patient died of cancer 36 months after the event of ureteral stump metastasis.

Carcinoma, Renal Cell↗

PubMed2000

A novel injectable bioactive bone cement for spinal surgery: a developmental and preclinical study.

The injection of bone cement by minimally invasive techniques for the treatment of vertebral body fractures or for stabilization of an osteoporotic vertebral body is regarded as promising in spinal surgery. The purpose of this study was to develop a novel injectable bioactive bone cement to address such concerns. The cement was composed mainly of strontium-containing hydroxyapatite (Sr-HA) filler and Bisphenol A Diglycidylether Dimethacrylate (D-GMA) resin. The Sr-HA filler was prepared by precipitation and calcination, then analyzed with Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns. Samples of strontium-containing hydroxyapatite cement (SrHAC) were formed by a combination of powder filler and resin matrix, with the setting time and peak temperature recorded. Cell relative growth rate (RGR), Tetrazolium bromide (MTT), and haemolysis tests were used to detect initial in vitro biocompatibility of the new cement. In vitro spinal biomechanical testing and morphological observation after bone cement injection were performed on pig spines. Results indicate that the setting time and peak temperature of the cement was 15 min and 55 degrees C, respectively. Cytotoxicity of the cement was class 1 (no cytotoxicity) and haemolysis was 1% (no haemolysis). Stiffness after cement injection and fatigue loading were 112% and 95% of the intact bone, respectively, which is similar to that of natural bone. Radiopacity of SrHAC allowed easy radiographic imaging. The use of SrHAC cement is, thus, promising in spinal surgery.

Animals↗

PubMed2000

Posterior slope of tibial plateau in Chinese.

The posterior slope of tibial plateau in 25 pairs of Chinese cadaveric tibia was studied. A digital photograph of the lateral profile of each cadaveric tibia was taken, and the posterior slope angles of medial and lateral plateau relative to the anterior tibial cortex were measured. The posterior slope of the medial plateau was 14.8 degrees, and the posterior slope of the lateral plateau was 11.8 degrees. Lateral radiographs of each cadaveric tibia were taken, and the posterior tibial slope angles relative to simulated extramedullary and intramedullary alignment were determined. With radiographic measurement, the posterior slope was 11.5 degrees using intramedullary method, and it was 14.7 degrees using extramedullary method. The posterior slopes increased with the presence of degenerative changes.

Aged↗

PubMed2000

Silent compartment syndrome complicating total knee arthroplasty: continuous epidural anesthesia masked the pain.

Posterior dislocation is an uncommon complication of total knee arthroplasty (TKA) using a posterior stabilized total knee prosthesis, and it usually results from flexion instability. Acute posterior dislocation of a posterior stabilized prosthesis complicated by compartment syndrome of the leg has not previously been reported in the literature. We report a 62-year-old woman with posterior dislocation of her posterior stabilized TKA when her knee was in extension. It was further complicated by compartment syndrome with severe muscle necrosis. The diagnosis of compartment syndrome was delayed, partly because of continuous epidural anesthesia that completely abolished the pain and partly because of the low index of suspicion, as compartment syndrome is not well recognized as a possible complication of TKA. This case report strongly emphasizes that continuous epidural anesthesia is contraindicated in the case of complicated TKA because important clinical cues to neurovascular complications could be masked.

Anesthesia, Epidural↗

PubMed2000

Primary total hip arthroplasty in patients with ankylosing spondylitis.

The results of total hip arthroplasty in a group of patients with ankylosing spondylitis are described. Ninety-five arthroplasties were performed in 56 men and 2 women whose average age at operation was 38.9 years (standard deviation [SD], 11.6; range, 19.2-78.8). They were followed for an average of 135.4 months (SD, 81.6; range, 24.4-331.2). We encountered 4 deep infections necessitating the removal of prostheses. Two of 3 dislocations were anterior dislocations. Nineteen arthroplasties were revised at an average of 162.0 months (SD, 49.6; range, 55.1-250.5) after the primary surgery; 9 of them had only the acetabular component revised because of aseptic loosening. Hyperextension of the hips is a common phenomenon that can lead to surgical error and predispose the prosthesis to anterior dislocation.

Adult↗

PubMed2000

The use of intravenous atropine after a saline infusion in the prevention of spinal anesthesia-induced hypotension in elderly patients.

UNLABELLED: We investigated the efficacy of IV atropine for preventing spinal anesthesia-induced hypotension in elderly patients. Seventy-five patients undergoing transurethral prostate or bladder surgery were randomized to receive either placebo (n = 25), atropine 5 microg/kg (small-dose atropine, n = 25) or atropine 10 microg/kg (large-dose atropine, n = 25) after the induction of spinal anesthesia. All the patients received an IV infusion of 10 mL/kg 0.9% normal saline over 10 min before the induction of anesthesia. The systolic blood pressure decreased in all three groups after spinal anesthesia. There was a significant increase in the mean heart rate in both atropine groups as compared to the placebo group (placebo group: 78 bpm, 95% confidence interval [CI]: 76.6-78.5; small-dose atropine group: 86 bpm, 95% CI 83.9-88.8; large-dose atropine group: 97 bpm, 95% CI 94.5-100.3; P: = 0.001). There was a significant decrease in the incidence of hypotension in patients who received atropine (placebo group: 76%, small-dose atropine group: 52%, large-dose atropine group: 40%, P: = 0.03). The mean dose of ephedrine required was significantly decreased in the atropine groups (placebo group: 12.2 mg [SD= 10.5], small-dose atropine group: 7.4 mg [SD= 10.0], large-dose atropine group: 5.4 mg [SD= 8.7 mg], P: = 0.048). The total amount of IV fluid and number of patients requiring metaraminol in addition to 30 mg of ephedrine were not significantly different among the three groups. Significant side effects, such as confusion, ST segment changes or angina were not detected in any of the patients. We conclude that IV atropine may be a useful supplement to the existing methods in preventing hypotension induced by spinal anesthesia. IMPLICATIONS: IV atropine increases heart rate in a dose-dependent manner in elderly patients undergoing spinal anesthesia. It reduces the incidence of hypotension and the dose of ephedrine required. Small-dose atropine may be a useful supplement in preventing spinal anesthesia-induced hypotension in elderly patients.

Aged↗

PubMed2000

Axial alignment of the lower extremity in Chinese adults.

BACKGROUND: The restoration of normal axial alignment of the lower extremity is important to surgeons who perform reconstructive surgery of the knee. However, data on the normal alignment of the lower extremity in Chinese adults are not available. METHODS: The axial alignment of the lower extremity in twenty-five adult male and twenty-five adult female volunteers of southern Chinese origin was measured on weight-bearing radiographs of the entire lower limb. The mean age was twenty-four years for the male volunteers and twenty-three years for the female volunteers. The results were compared with those of two similar studies of white volunteers in the United States. RESULTS: The medial inclination of the tibial plateau in the Chinese subjects (mean and standard deviation, 5.4 +/- 2.5 degrees for women and 4.9 +/- 2.3 degrees for men) was greater than the commonly reported 3 degrees. The extremities of the Chinese women were found to have a mean of 2.2 +/- 2.5 degrees of varus alignment, and those of the Chinese men had a mean of 2.2 +/- 2.7 degrees of varus alignment. CONCLUSIONS: Compared with the white subjects described in the studies by Moreland et al. and Hsu et al., the Chinese subjects had significantly larger medial inclination of the knee joint (knee-joint obliquity) (p < 0.005) and the female Chinese subjects had significantly more varus alignment of the lower extremity (p < 0.025). CLINICAL RELEVANCE: Five degrees of external rotation of the femoral component, instead of the commonly reported 3 degrees, may be required to obtain a rectangular flexion gap in total knee arthroplasty in Chinese patients. The racial difference in the knee-joint obliquity may contribute to the racial difference in the ratio of knee osteoarthritis to hip osteoarthritis. Additional studies are necessary to confirm this relationship.

Adult↗

PubMed2000

Expression of nm23 protein in human osteosarcoma in relationship with early metastasis.

Nm23 protein expression was analyzed by immunohistochemical staining using formalin-fixed, paraffin-embedded sections from 39 cases with osteosarcomas and compared with the histologic findings and early metastasis for the purpose of detecting nm23 expression in osteosarcoma and elucidating the clinical significance of its expression. Immunoreactivity of nm23 protein was detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but there was a trend for cases with nm23 expression to progress to early metastasis within 1 year after operation. The role of nm23 as a tumor metastasis suppressor in osteosarcomas appeared less prominent.

Adolescent↗

PubMed1999

Parent management training in a Chinese population: application and outcome.

OBJECTIVE: To examine the applicability and outcome of parent management training in a group of Chinese children referred for aggressive and defiant behaviors. METHOD: Twenty-five children (aged 4-10 years) were assigned to a standardized 8 to 12 sessions of parent management training. Trained child and adolescent psychiatric nurses conducted the treatment. Measures taken at pretreatment, posttreatment, and 4-month follow-up period included the Child Behavior Checklist, direct observation of parent-child interactions, and a parent perception inventory. RESULTS: Significant therapeutic gains occurred in parent-child interactions, externalizing behaviors, and parents' perception of their parenting behaviors. These were maintained at 4-month follow-up. Fifty-two percent of cases improved to a level below clinical cutoffs. Poor parent-child interactions had stronger correlation with externalizing disturbances than internalizing disturbances. The changes in parent-child interactions had low correlation with the changes in the symptom profiles. CONCLUSIONS: The data provide preliminary evidence for the efficacy of parent management training for Chinese children with conduct problems. The rationale for its success and modifications to improve its cultural sensitivity are discussed.

Adult↗

PubMed1998

Preliminary observation on the correlation between nm23 expression and Ki-67 antigen with early metastasis of human osteosarcoma.

OBJECTIVES: To detect the nm23 expression in osteosarcoma, analyze the correlation between nm23 expression and early metastasis and to study the relation between nm23 expression with tumor differentiation and cell proliferation, as defined by Ki-67 labeling. METHODS: nm23 oncoprotein expression was measured by immunohistochemical staining using formalin fixed, paraffin embedded sections of 39 surgically resected osteosarcomas and was compared with Ki-67 expression, histological findings and early metastasis. In each sample, the grading of immunoreactivity was recorded as 0, 1+, 2+ according to the percentage of nm23 and Ki-67 labeling cells respectively. RESULTS: The cases with more than 25% positive immunoreactivity of nm23 protein were detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but the cases with nm23 expression appeared to have a trend to get early metastasis. nm23 expression was significantly correlated with Ki-67 expression, which was associated with differentiation of the tumor cells. CONCLUSION: The role of nm23 as a tumor metastasis suppressor in osteosarcoma is less prominent. Both nm23 and Ki-67 may help predict the possibility of early metastasis in human osteosarcomas.

Adolescent↗

PubMed1996

Seasonal variation of fractures of the hip in elderly persons.

A prospective study was made of 1500 elderly patients who suffered from acute hip fractures from 1986 to 1990. There were 36 per cent more fractures in the 6 colder months from November to April than in the rest of the year (P < 0.001). A strong correlation between the monthly adjusted fracture rate and the average lowest ambient temperature was also observed (P < 0.001). The fractures occurred in the older and less active patients during the 6 colder months. More importantly, they needed to wait longer for the operation during this 'high' season. This might be responsible for the higher medical complication rate after the operation. Better health care planning to help with the increased patient load in the 'high' season is essential to reduce the waiting time for the operation and the postoperative medical complication rate.

Aged↗

PubMed1995

Cord compression caused by multiple disc herniations and intraspinal cyst in Scheuermann's disease.

STUDY DESIGN: The design for this article is a case report. OBJECTIVES: Reported is the case of a patient with Scheuermann's disease who experienced spastic paraparesis caused by multilevel disc herniations and intraspinal meningeal cyst occurring together. SUMMARY OF BACKGROUND DATA: Although Scheuermann's disease is associated with disc degeneration and calcification, multilevel disc herniations causing neurologic deficit is exceedingly rare. METHODS: A patient diagnosed with Scheuermann's disease was evaluated by laboratory tests and radiographs because of paresthesin in bilateral lower extremities. RESULTS: Evaluation revealed a "cyst" that was separated from the proper subarachnoid space and a disc herniation. CONCLUSIONS: Intraspinal cyst and multilevel disc herniations could coexist in Scheuermann's disease. Both could contribute to cord compression. Drainage of the cyst, anterior decompression of the disc herniations, and interbody fusion to stabilize the diseased segments produced good results after 2 years.

Adult↗

PubMed1994

Immunohistochemical demonstration of c-erbB-2 oncoprotein in gastric adenocarcinoma: comparison of cryostat and paraffin wax sections and effect of fixation.

AIMS: To investigate the effects of fixation on the immunohistochemical demonstration of c-erbB-2 oncoprotein using paraffin wax and cryostat sections; to compare c-erbB-2 expression in non-neoplastic and neoplastic gastric tissues. METHODS: Adjacent blocks of tumour and non-neoplastic tissue from four gastrectomy specimens were put into a panel of 10 fixatives including acetone, B5, Bouin's fluid, Carnoy's fluid, buffered formalin, formol dichromate, zinc formalin, 4% paraformaldehyde, periodate-lysine-paraformaldehyde (PLP) and periodate-lysine-paraformaldehyde-dichromate (PLPD) before embedding in paraffin wax for sectioning. Similar tissue blocks were snap frozen and cryostat sections were postfixed in these fixatives, either alone or in combination, before immunostaining. RESULTS: In paraffin wax embedded sections the best fixative was PLP, and in frozen tissues the best results were obtained after fixation of cryostat sections in buffered formalin followed by cold methanol and acetone. Applying these fixatives to samples from a further 16 gastrectomy specimens, strong membrane staining of c-erbB-2 protein was found in the tumour in eight of 16 cases (50%) using paraffin wax sections, and staining was stronger in the better differentiated carcinomas. For frozen tissues, positive membrane staining was found in all gastric adenocarcinomas, but differential staining intensity associated with tumour differentiation could not be detected. CONCLUSIONS: These results indicate that fixation and paraffin wax embedding affect the results of immunohistochemical demonstration of c-erbB-2 in gastric cancer. The choice of fixative is critical in the demonstration and evaluation of c-erbB-2 protein expression by immunohistochemistry in gastric carcinomas. Staining results also vary depending on whether frozen or paraffin wax embedded tissues are studied.

Adenocarcinoma↗

PubMed1994

Cancellous screw fixation for subcapital femoral neck fractures.

Experience in treating 80 subcapital femoral neck fractures by AO/ASIF cancellous screws is reported. Immediate full-weight bearing was allowed routinely. The mean follow-up was 28 months. Non-union occurred in 2% and late segmental collapse in 12% of patients with undisplaced fractures. Non-union occurred in 16.7% and late segmental collapse in 30% of patients for displaced fractures. Regression of screws occurred in 30% of patients, all of which were detected within the first month after the operation. It was associated with a significantly higher risk of non-union and late segmental collapse for both undisplaced (P < 0.01) and displaced (P < 0.001) fractures.

Adult↗

PubMed1993

Plastic adhesive drapes and wound infection after hip fracture surgery.

One hundred and twenty patients with acute hip fractures treated operatively were randomized into two groups. In the 'drape' group (n = 65) the operation site was covered with plastic adhesive drape after preparation. In the 'no drape' group (n = 55) the operation site was left uncovered. The two groups were otherwise matched. Swabs for culture were taken from skin adjacent to the wound before closure. The drape group had four positive wound swabs. There was only one positive wound swab for the no-drape group. There was no difference in the post-operative wound infection rates.

Adhesiveness↗

PubMed1993

The use of double latex gloves during hip fracture operations.

A prospective study was undertaken to determine the perforation rate of surgical gloves when double-gloving techniques were employed in 120 hip fracture operations. One or more perforations occurred in 30 operations (25%). In 10 operations (8.3%), perforations of both the outer and inner gloves occurred at corresponding sites. The surgeons were able to recognize the perforations during the surgery on five occasions only. Of the 64 perforations identified, 41 (64%) occurred in the left (nondominant) hands, and 42 (65.6%) occurred at the tips of thumbs and index fingers. Nearly half of the perforations (46.9%) occurred at the thumb and index finger of left (nondominant) hands. To reduce the perforation rate, further protection of the thumb and index finger of the nondominant hand of surgeons is therefore required.

Accidents, Occupational↗

PubMed1992

A prospective study on hip fractures in patients with previous cerebrovascular accidents.

Of 1430 patients with proximal femoral fractures admitted into Queen Mary Hospital, Hong Kong from 1985 to 1990, 146 patients (10.2 per cent) had a history of previous cerebrovascular accidents. The fracture was on the hemiplegic side in 82 percent of patients. Most patients were treated by operation. Intensive physiotherapy was given to these patients for an average of 6 weeks. The prefracture walking ability was regained or even improved upon discharge in 60.9 per cent of patients. After an average follow-up of 21 months, 31 per cent had satisfactory walking and active daily activities. There was significant correlation of the performance upon discharge from the hospital with the walking ability at the final follow-up.

Aged↗