Displaying publications 1 - 20 of 35 in total

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  1. Kwan MK, Chiu CK, Lee CK, Chan CY
    Bone Joint J, 2015 Nov;97-B(11):1555-61.
    PMID: 26530660 DOI: 10.1302/0301-620X.97B11.35789
    Percutaneous placement of pedicle screws is a well-established technique, however, no studies have compared percutaneous and open placement of screws in the thoracic spine. The aim of this cadaveric study was to compare the accuracy and safety of these techniques at the thoracic spinal level. A total of 288 screws were inserted in 16 (eight cadavers, 144 screws in percutaneous and eight cadavers, 144 screws in open). Pedicle perforations and fractures were documented subsequent to wide laminectomy followed by skeletalisation of the vertebrae. The perforations were classified as grade 0: no perforation, grade 1: < 2 mm perforation, grade 2: 2 mm to 4 mm perforation and grade 3: > 4 mm perforation. In the percutaneous group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and one (0.7%) grade 2 perforations. In the open group, the perforation rate was 8.3% (12 screws) and all were grade 1. This difference was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures in the percutaneous group and 21 (14.6%) in the open group (p = 0.73). In summary, the safety of percutaneous fluoroscopy-guided pedicle screw placement in the thoracic spine between T4 and T12 is similar to that of the conventional open technique.
  2. Chiu CK, Kwan MK, Chan CY, Schaefer C, Hansen-Algenstaedt N
    Bone Joint J, 2015 Aug;97-B(8):1111-7.
    PMID: 26224830 DOI: 10.1302/0301-620X.97B8.35330
    We undertook a retrospective study investigating the accuracy and safety of percutaneous pedicle screws placed under fluoroscopic guidance in the lumbosacral junction and lumbar spine. The CT scans of patients were chosen from two centres: European patients from University Medical Center Hamburg-Eppendorf, Germany, and Asian patients from the University of Malaya, Malaysia. Screw perforations were classified into grades 0, 1, 2 and 3. A total of 880 percutaneous pedicle screws from 203 patients were analysed: 614 screws from 144 European patients and 266 screws from 59 Asian patients. The mean age of the patients was 58.8 years (16 to 91) and there were 103 men and 100 women. The total rate of perforation was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade 3 perforations. The rate of perforation in Europeans was 10.4% and in Asians was 8.6%, with no significant difference between the two (p = 0.42). The rate of perforation was the highest in S1 (19.4%) followed by L5 (14.9%). The accuracy and safety of percutaneous pedicle screw placement are comparable to those cited in the literature for the open method of pedicle screw placement. Greater caution must be taken during the insertion of L5 and S1 percutaneous pedicle screws owing to their more angulated pedicles, the anatomical variations in their vertebral bodies and the morphology of the spinal canal at this location.
  3. Muhammad MT, Kwan MK, Chan CY, Lim BS, Goh DW
    Med J Malaysia, 2012 Dec;67(6):633-5.
    PMID: 23770965 MyJurnal
    A 15-year-old teenager with Type 1 Neurofibromatosis presented with grade 4 spondylolisthesis over T12/L1 junction resulting paraparesis (Frankel D). Radiograph showed a Cobb angle of 88 degrees. Computed tomography scan showed dysplastic vertebral bodies, pedicles and facet joints of T11, T12 and L1 vertebra with complete T12/L1 facets dislocation. Magnetic resonance imaging confirmed presence of spinal cord compression. He underwent posterior instrumentation and posterolateral fusion (T8 to L4) using hybrid instrumentation. Extensive corticotomy of the posterior elements was followed by the use of large amount of bone graft. Post operatively, his neurology improved markedly back to normal. Radiographs showed a good correction of the deformity. He was immobilized in a thoracolumbar orthosis for six months. A solid posterior fusion was achieved at six months follow up. At 36-month follow up, he remained asymptomatic. This case report illustrates a successful treatment of a grade 4 thoracolumbar spondylolisthesis secondary to neurofibromatosis with posterior spinal fusion alone.
  4. Chan CYW, Kwan MK, Saw LB, Deepak AS, Chong CS, Liew TM, et al.
    Med J Malaysia, 2008 Jun;63(2):137-9.
    PMID: 18942300
    Adolescent Idiopathic Scoliosis is a spinal deformity which affects patients' self image and confidence. Surgery is offered when the curve is more than 50 degrees based on its likelihood of progression. Studies on the radiological outcome of scoliosis correction are abundant. Therefore, it is the objective of this study to evaluate the health related quality of life in scoliosis patients who had undergone surgical correction in University Malaya Medical Center, Kuala Lumpur, Malaysia using Scoliosis Research Society-22 (SRS-22) patient questionnaire. This is a prospective evaluation of SRS-22 scores of thirty eight patients operated in our center over the past five years with a minimum follow up of one year. There were thirty two females and six males. Twenty six (68.4%) were Chinese, eight (21.1%) Malay and four (10.5%) Indian patients. The age of the patients ranged from twelve to twenty eight years, with a mean age of 18.4 +/- 3.5. Based on the King and Moe's classification, sixteen patients had King's 3 curve. The mean pre-operative Cobb angle was 68.6 degree and post-operative Cobb angle was 35.8 degree. The average curve correction was 48.5%. The overall score for SRS-22 was 4.2. The SRS-22 scores were highest for the pain domains and lowest for the functional domains. Satisfaction domain scored 4.3. The function domain scored significantly higher in those who have twenty four months or less follow up duration. Curve magnitude and the amount of correction did not significantly alter the SRS scores. In conclusion, patients were satisfied with the outcome of their operation. Although pain was common, the intensity of the pain was minimal. The amount of curve correction did not correlate with the quality of life after operation.
  5. Chan CY, Kwan MK, Saravanan S, Saw LB, Deepak AS
    Med J Malaysia, 2007 Mar;62(1):33-5.
    PMID: 17682567 MyJurnal
    Assessment of the curve flexibility is a crucial step in a surgeon's pre-operative planning for scoliosis surgery. Many techniques have been described. These include traction films, supine side bending films, push prone techniques, traction under general anaesthesia as well as fulcrum bending film. In this study, we studied the pre- and immediate post-operative radiographs of twenty eight adolescent idiopathic scoliosis (AIS) patients who were corrected using pedicle screw systems between January 2004 and August 2006. There were twenty two females and six male patients. The mean age of the patients were 17.5 years with a range of 12 to 38 years. Skeletal maturity of the patients was assessed by Risser's score. The majority was Risser 4 (15 cases, 53.6%). Based on King and Moe's classification, the most common curve was type 3 curve (15 cases, 53.6%). Among the twenty eight patients, twenty three patients underwent only posterior correction, while 5 patients underwent additional anterior release surgery. The mean pre-operative Cobb's angle for the posterior surgery group was 65.5 +/- 13.9 degrees and the mean post-operative Cobb's angle was 32.9 +/- 12.6 degrees. There was no difference between the mean correction estimated by fulcrum bending films (Fulcrum Flexibility) and the post- operative Correction Rate figures (44.2% vs. 49.9%). The mean Fulcrum Bending Correction Index (FBCI) in this group of patients is 112.8%. In the group of patients who underwent additional anterior release, their curves were noted to be larger and less flexible with the mean pre-operative Cobb's angle and Fulcrum Flexibility of 90.4 degrees +/- 9.3 degrees and 23.4% respectively. The Fulcrum Bending Correction Index (FBCI) for this group of patients was significantly higher than the posterior surgery group: i.e. 164.0% vs 112.8%. Thus, anterior release does help to improve the correction significantly. The fulcrum bending films give good pre-operative estimation of the amount of correction to be expected post-operatively. The fulcrum bending films can help to identify the curve types which might require anterior release in order to improve the scoliosis correction. Using the Fulcrum Bending Correction Index (FBCI) will also enable surgeons to quantify more accurately the amount of correction achieved by taking into account the inherent flexibility of the spine.
  6. Ng SS, Kwan MK, Ahmad TS
    Med J Malaysia, 2006 Dec;61 Suppl B:13-7.
    PMID: 17600987
    This study is designed to evaluate twenty patients after sural nerve harvest using the single longitudinal incision method. The area of sensory loss to pin prick was assessed by the authors at different intervals. Donor site factors, scar cosmesis, functional status and complications were assessed using a questionnaire. The mean area of anaesthesia at one month was 65 cm2 and it had reduced by 77% to 15 cm2 at one and a half years. The mean area of reduced sensation was 49 cm2 at one month and it increased by 18% to 58 cm2 over the same period. Therefore, the total area of sensory deficit was reduced by 36% from 114 cm2 at one month to 73 cm2 at one and a half years. Subjective patient evaluation indicated moderate level of pain during immediate post surgical period, which reduced significantly at one month. A low level of neuroma symptoms was recorded throughout the study period. At a mean follow-up period of two years, there was no area of anaesthesia in 50% of the patients. Mean area of anaesthesia for all patients was 12 cm2 and mean area of reduced sensation was 55 cm2. Subjective patient evaluation indicated a low level of pain, neuroma symptoms and numbness over the sural nerve sensory distribution. Twenty five percent of the patients were not satisfied with the scar appearance. Function and daily activities were not affected significantly. No surgical complications were observed.
  7. Ling HT, Kwan MK, Chua YP, Deepak AS, Ahmad TS
    Med J Malaysia, 2006 Dec;61 Suppl B:8-12.
    PMID: 17600986
    Treatment of radius or ulna nonunion requires both osteogenic environment and mechanical stability. We would like to report three radial and six ulnar diaphyseal nonunions treated with 3.5 mm locking compression plate (LCP) fixation. To assess the effectiveness of 3.5 mm LCP in treating diaphyseal nonunion of the forearm bones, we prospectively reviewed nine patients with the mean age of 33 years with diaphyseal nonunion of the radius or ulna. All patients were treated with 3.5 mm LCP. Bone grafting was only performed for atrophic nonunion. Surgical and functional outcome were evaluated. There were three atrophic nonunion of the radius, four atrophic nonunion of the ulna and two hypertrophic nonunion of the ulna. All nonunion united successfully with satisfactory functional outcome. 3.5 mm LCP is effective in the treatment of nonunion of ulna or radius.
  8. Tan WJ, Kwan MK, Deepak AS, Saw A, Peng BC, Jalalullah W
    Med J Malaysia, 2006 Dec;61 Suppl B:18-22.
    PMID: 17600988
    Fracture of the femur is most commonly treated with interlocking nailing. We conducted this study to describe and analyze the size of femoral interlocking nails used in our local population. This is a retrospective study on reamed intramedullary interlocking nailing procedures performed between 1st July 1998 and 30th June 2003. Demographic data, the diameter and length of femoral nails used were obtained from patient's medical record. A total of 267 procedures were included. The most common diameter used was 10 mm (56.9%), followed by 11 mm (27.0%) and 12 mm (13.1%). Only 2.6% of the nails were less than 10 mm in diameter. The most common nail length was 38 cm (31.1%), followed by 36 cm (24.9%) and 40 cm (19.5%). The longest nail used was 46 cm while the shortest 32 cm. The most commonly used femoral nails were of 10 mm diameter with the length ranging from 36 to 40 cm, which is smaller than those reported in the English literature. Nails with diameter smaller than 10 mm were required in 2.6% of patients.
  9. Ling HT, Kwan MK, Saw A, Choon DS
    Med J Malaysia, 2006 Aug;61(3):380-2.
    PMID: 17240598 MyJurnal
    The incidence of wound related complication following total knee arthroplasty is as high as 10%-20%. To perform total knee arthroplasty in a knee with extensive scarring around the knee can be a challenging task. We report a case of 55-year-old diabetic woman, who had total knee arthroplasty, performed two years after she had recovered from necrotizing fasciitis around the right knee. Understanding the vascular anatomy around the knee is of paramount importance in the planning of skin incision to ensure fewer wound related complications.
  10. Kwan MK, Saw A, Chee EK, Lee CS, Lim CH, Zulkifle NA, et al.
    Med J Malaysia, 2006 Feb;61 Suppl A:17-20.
    PMID: 17042223
    Necrotizing fasciitis is a limb- and life-threatening rapidly spreading infection affecting the deep fascia with secondary necrosis of the subcutaneous tissue. It requires immediate medical attention and emergency surgery to prevent morbidity and death. This study was undertaken to determine its co-morbidity and risk factors affecting the outcome of its surgical treatment. This is a retrospective review of 36 cases of necrotizing fasciitis of the lower limb treated in our center between 1998 and 2002. Only 19% of the cases were correctly diagnosed upon admission and 48.6% were initially diagnosed as 'cellulitis'. Diabetes mellitus was the most common co-morbid. Pseudomonas, Staphylococcus, Streptococcus and Enterobactericae were the common pathogens isolated. Ten patients (27.8%) had major amputation as part of radical debridement. The overall mortality rate was 36% with laboratory parameters: high serum urea and creatinine, and low haemoglobin levels were predictors for higher mortality. Poor white cell response which is common in diabetic patients and a delay in surgical debridement were. notable attributes to a higher mortality. Necrotizing fasciitis is a serious infection associated with significant morbidity and mortality. A poor white blood cell response, high serum urea and creatinine, and low haemoglobin level were the predictors for mortality. Early diagnosis and prompt treatment are of paramount importance in the treatment of this infection.
  11. Kwan MK, Ng ES, Penafort R, Saw A, Sengupta S
    Med J Malaysia, 2005 Jul;60 Suppl C:66-71.
    PMID: 16381287 MyJurnal
    Bone defect following en bloc resection of primary bone tumor around the knee can be reconstructed by allograft or prothesis or combination of both. Resection-arthrodesis is an alternative option for young vigorous patients facing circumstances of financial constrain or limited supply of allograft. This study was undertaken to determine the outcome and complications associated with resection-arthrodesis of 22 primary bone tumors (13 giant cell tumors and 9 osteosarcomas) around the knee treated between 1990 and 2003 at the University Malaya Medical Center. The mean follow-up was 6 years (range 1-13 years). hree patients with osteosarcoma died of lung metastasis, 3 required above knee amputation and 2 defaulted follow-up. Local complications of the procedure include infection in 8 cases (36.4%), non-union 7 (31.8%) and mal-union. Of 14 patients who returned for final evaluation, 79.8% had satisfactory outcomes according to the Musculoskeletal Tumor Society grading system. In conclusion, resection-arthrodesis of the knee is a viable treatment option for selected patients with primary bone tumor around the knee, and good functional outcome can be expected in the presence of short-term local complications.
  12. Chua YP, Kwan MK, Saw A
    Med J Malaysia, 2005 Jul;60 Suppl C:78-82.
    PMID: 16381289
    The need for perioperative blood transfusion in elderly patients with trochanteric fracture scheduled for elective dynamic hip screw fixation has recently been questioned following reports on the association between allogeneic blood transfusion and post-operative infections. This retrospective study was undertaken to assess the amount of per operative blood loss and transfusion requirement in relation to pre-operative haemoglobin level in 198 patients with trochanteric fractures. The average per operative blood loss was 409 ml and it correlated well with the duration of the operation. More than half of the patients (52.5%) required blood transfusion and nearly three-quarters were anaemic prior to the surgery. Proactive pre-operative measures to optimize the patient's haemoglobin level and intra-operative minimization of blood loss are essential steps to obviate the need for perioperative allogeneic blood transfusion.
  13. Wong ELW, Kwan MK, Loh WYC, Ahmad TS
    Med J Malaysia, 2005 Jul;60 Suppl C:72-7.
    PMID: 16381288
    Shoulder arthrodesis is a secondary reconstructive option for patients with brachial plexus injuries requiring a stable shoulder. This study was undertaken to evaluate the clinical and radiological outcomes of shoulder fusion in six patients with flail upper limbs following complete brachial plexus injuries. The shoulder was fused in 30 degrees abduction, 30 degrees internal rotation and 30 degrees flexion via a direct lateral approach by using a 4.5 mm reconstruction plate without bone grafting. The average follow-up was 10.3 months. Radiological union was obtained in all patients. Five patients (83%) had relief of pain after the shoulder fusion. Improvement of function was observed in all patients with a mean improvement of 56.6 degrees (range 30 degrees-75 degrees) and 47.5 degrees (range 30 degrees-60 degrees) active flexion and abduction respectively. One patient developed humeral fracture distal to the plate and the fracture eventually healed with a splint. Successful stable fusion of the shoulder in patients with brachial plexus injuries requires rigid fixation with a single 4.5 mm reconstruction plate, protection of bone healing with a triangular abduction brace for 12 weeks and functional trapezius, levator scapulae, serratus anterior and rhomboid muscles for optimizing the functional result.
  14. Kwan MK, Marican AM, Ahmad TS
    Med J Malaysia, 2005 Jul;60 Suppl C:104-7.
    PMID: 16381293
    Soft tissue loss of the heel is difficult to treat as it may cause significant morbidity particularly recurrent ulceration and subsequent chronic osteomyelitis. Reconstruction of such defect with local flap can provide good result. We report our experience in treating four patients with heel defect using the in-step island flap. The flap, which is based on the medial plantar neurovascular pedicle, provides a sensate durable tissue required for weight-bearing and normal gait.
  15. Abbas AA, Merican AM, Kwan MK, Mohamad JA
    Med J Malaysia, 2006 Feb;61 Suppl A:83-7.
    PMID: 17042237
    Total knee arthroplasty is the most preferred option for treatment of severe osteoarthritis of the knee. We report the short-term outcome of 48 total knee replacements in 31 patients utilizing the Apollo Total Knee System after an average follow-up of 48 months (range 15 to 70 months). Records of all patients who underwent TKA using Apollo Total Knee System were retrospectively reviewed. Functional outcome was evaluated using visual analogue scale for pain rating and the Oxford 12-item questionnaire. Postoperative radiographs of the replaced knees were assessed by using the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Degenerative osteoarthritis was the commonest indication for TKA. The average patient's age was 63.7 years (range, 30-77 years). The mean visual analogue scale for pre- and post-operative pain was eight and zero respectively. The mean Oxford 12-item questionnaire score pre- and post-operatively was 44.8 and 16.5 respectively. Patient satisfaction was notable in 98% of the cases with an average improvement in arc of flexion of 111 degrees. There were four failures; deep infection (one) and aseptic loosening (three) giving rise to a 94% implant survivor. The short-term results of this series is comparable with or better than a number of outcome studies of the Apollo Knee System or other implants of similar design.
  16. Kwan MK, Saw A, Sara Ahmad T
    Med J Malaysia, 2005 Mar;60(1):112-4.
    PMID: 16250295 MyJurnal
    We are reporting four cases of serious washing machine related injury that presented within a period of 5 months. All patients were young children with the mean age of 9 year-old and three had their dominant hand injured. The washing machines involved were the automatic top loader type and all injuries occurred during the spinning phase. Serious automatic washing machine injury is not uncommon in Malaysia. We feel that there is a need to improve the safety features especially during the spinning phase. The operating instructions and safety precautions on the washing machine should be displayed in different languages that can be understood well. Parents should also aware of the potential risks of this seemingly benign household appliance.
  17. Merican AM, Kwan MK, Cheok CY, Wong ELW, Sara TA
    Med J Malaysia, 2005 Jun;60(2):218-21.
    PMID: 16114164
    Near total amputation of the upper limb if unsalvageable would cause severe disability. However, delayed revascularisation can be life threatening. We report two cases of revascularisation of the upper limb following near total amputation that was successful and functional after a warm ischaemic time of ten hours. The first was a traction avulsion injury of the arm leaving major nerves contused but in continuity. The second was a sharp injury through the mid-forearm attached by only a bridge of skin. Attempting revascularisation of a proximal injury beyond 6 hours, in selected cases is worthwhile.
  18. Mohamad JA, Kwan MK, Merican AM, Abbas AA, Kamari ZH, Hisa MK, et al.
    Med J Malaysia, 2004 Dec;59 Suppl F:3-7.
    PMID: 15941153
    We report our early experience of 20 cases of metal on metal articulation total hip arthroplasty in 19 young patients. Avascular necrosis of the femoral head (63%) was the commonest diagnosis for patients undergoing this procedure, followed by osteoarthritis (21%). In general, most of the patients were young and physically active with an average age of 43.1 years (range, 25 to 58 years). The average follow-up period was 18 months (range, 7 to 46 months). The mean total Harris Hip Score preoperatively and at final follow-up was 31 points and 89 points respectively. The mean total Pain Score improved from an average of 11.5 to 41.1 points at final follow-up. Sixteen (84%) of the patients had a good to excellent hip score. There was one dislocation, which stabilized after reduction and conservative management. One case of early infection underwent a two-staged revision.
  19. Kwan MK, Penafort R, Saw A
    Med J Malaysia, 2004 Dec;59 Suppl F:39-41.
    PMID: 15941159
    Joint stiffness is one of the complications of limb procedure. It developes as a result of failure of knee flexors to lengthen in tandem with the bone, especially when there is inadequate physical therapy to provide active and passive mobilization of the affected joint. We are reporting four patients who developed fixed flexion contracture of their knees during bone lengthening procedure for the tibia with Ilizarov external fixator. Three of them were treated for congenital pseudoarthrosis and one was for fibular hemimelia. None of them were able to visit the physiotherapist even on a weekly basis. A splint was constructed from components of Ilizarov external fixator and applied on to the existing frame to passively extend the affected knee. Patients and their family members were taught to perform this exercise regularly and eventually near complete correction were achieved. With this result, we would like to recommend the use of this "Passive Knee Extension Splint" to avoid knee flexion Contracture during limb lengthening procedures with Ilizarov external fixators.
  20. Kwan MK, Chooi WK, Lim HH
    Med J Malaysia, 2004 Dec;59 Suppl F:14-8.
    PMID: 15941155
    Between April 1998 and December 1999, thirty patients with Idiopathic Scoliosis were operated with Multisegmented Hook-Rod System. These patients were operated at the mean age of 16 years and were followed up for a mean of 22.3 months (range 13-34 months). Seven patients had anterior release to increase the curve flexibility followed by second stage posterior instrumentation on the same day. The average operating time for a posterior instrumentation alone and anterior release combined with posterior instrumentation were 270 minutes and 522 minutes respectively. The average blood loss was 2.2 litres for posterior instrumentation alone and 3.3 litres for single day anterior release and posterior surgery. The mean preoperative Cobb's angle was 70 degrees. The mean immediate postoperative and final follow up Cobb's angles were 38 and 42 degrees, which represented an average coronal plane correction of 46.7% and 40.0% respectively. The mean preoperative apical vertebral rotation was 25 degrees, which improved to 15 degrees after the operation. At final follow up, the mean apical vertebra rotation was 20 degrees, which represented a mean apical vertebral rotation correction of 20%. Complications of the procedure included one transient neurological deficit, one infection, one graft site infection and one case of screw cut out. We were able to obtain satisfactory correction of idiopathic scoliosis with the Multisegmented Hook-Rod System.
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