Biomedical subjects

M H A Malik

Publications and source records attributed to M H A Malik.

12 recordsLinked to original sources

PubMed2006

Preliminary radiological evaluation of the Vector Vision CT-free knee module for implantation of the LCS knee prosthesis.

We have assessed the bone cuts achieved at surgery as compared to the planned cuts produced during computer assisted surgery (CAS) using a CT-free navigation system. In addition, two groups of matched patients were compared to assess the post-operative mechanical alignment achieved. Fourteen patients received a LCS total knee replacement (TKR) using the Vector Vision module and 14 received a TKR using a conventional method of extramedullary alignment jigs. The deviation in each plane (valgus-varus, flexion-extension and proximal-distal) was calculated. For the tibia the mean deviation in coronal plane was 0.21 degrees of varus (SD=1.37) and in the sagittal plane was 1.29 degrees of flexion (SD=3.73) and 0.24 mm of resection distal to the anticipated cut (SD=2.14). For the femur the mean deviation in the coronal plane was 0.88 degrees (SD=2.2) of valgus and in the sagittal plane the mean deviation was 0.3 degrees (SD=2.91) of extension. In the transverse plane there was a mean deviation of 0.07 degrees (SD=1.57) of external rotation. There was a mean deviation of 2.33 mm of proximal resection (SD=2.9) and 1.05 mm of anterior shift (SD=2.81). On comparing the two groups, no statistically significant differences were found for the angles between the femoral component and the femoral mechanical axis, the tibial component and the tibial mechanical axis, the femoral and tibial mechanical axis and the femoral and tibial anatomical axis. This study has presented preliminary data regarding the efficacy of a particular navigation system with regards to improving upon the accuracy of component position with the long-term aspiration of improving upon TKR longevity. A further randomised controlled trial with greater numbers of cases and controls would improve upon our knowledge as to the efficacy of the Vector Vision system and a power analysis based upon the findings of this pilot study has suggested that at least thirty subjects be included in each group.

Adult↗

PubMed2006

Cement pressurisation in the acetabulum.

Cement pressurisation is an important step in total hip arthroplasty that determines the long-term integration at the cement-bone interface. Our aim was to evaluate the performance of a new pressuriser designed by us against the standard existing pressurisers in an in vitro experimental set-up using two parameters: cement penetration and cement pressurisation. A polypropylene cup model was designed to represent the acetabulum. DePuy's T-handle, Exeter and our own plunger type pressuriser were each tested for cement pressurisation in this acetabular model. Cement penetration and pressures were measured. The cement intrusion into the capillaries with the DePuy pressuriser was found to vary between 2 and 8 mm (mean: 5 mm at the pole and 4.6 mm at the rim), with the Exeter pressuriser it varied between 3 and 9 mm (mean: 5.8 mm at the pole and 7.8 mm at the rim) and with the plunger type pressuriser it varied between 4 and 6 mm (mean 5.2 mm at the pole and 4.8 mm at the rim). The peak pressure achieved with the DePuy pressuriser was 60 kPa whereas it was 70 kPa with the plunger type pressuriser. The mean penetration with the plunger type pressuriser was found to be better than the other types. The penetration was found to be more uniform with equal penetration at the rim as well as at the pole.

Acetabulum↗

PubMed2006

Genetic susceptibility to hip arthroplasty failure--association with the RANK/OPG pathway.

The OPG/RANK/RANKL system has been implicated in the biological cascade of events initiated by particulate wear debris and bacterial infection resulting in periprosthetic bone loss around total hip arthroplasties (THA). Individual responses to such stimuli may be dictated by genetic variation caused by single nucleotide polymorphisms (SNPs). Case control study of the osteoprotegerin and RANK genes for possible association with deep sepsis or aseptic loosening. All patients were Caucasian and had had a cemented Charnley THA and polyethylene acetabular cup. Cases consisted of 91 patients with early aseptic loosening and 71 patients with deep infection. Controls were 150 clinically and radiologically well-fixed THAs. DNA samples were genotyped using Taqman allelic discrimination. The A allele (p<0.001) and genotype A/A (p<0.001) for the OPG-163 SNP were associated with aseptic failure. Additionally, the RANK +575 (C/T SNP) T allele (p=0.004) and T/T genotype (p=0.008) frequencies were associated with aseptic failure. Comparing the septic group with the controls, the frequency of the A allele (p<0.001) and the genotype A/A (p<0.001) for the OPG-163 SNP were statistically significant. Aseptic loosening and deep infection of THA may be under the influence of susceptibility genes. SNP markers may serve as predictors of implant survival.

Adult↗

PubMed2006

An unusual case of talonavicular dislocation with associated ipsilateral foot fractures.

We describe a previously unreported form of a talonavicular dislocation complicated by navicular, talar neck and open calcaneal fractures. Prompt recognition and rapid reduction of fractures and dislocations gives the best possible outcome. The presence of serious distracting injuries can alter priorities, however the "lesser" injuries often lead to long term morbidity after recovery from the life-threatening injuries.

Adult↗

PubMed2006

Levels of evidence.

Explore the source record for details and available documents.

Evidence-Based Medicine↗

PubMed2006

Comfort assessment of personal protection systems during total joint arthroplasty using a novel multi-dimensional evaluation tool.

INTRODUCTION: A number of studies have assessed the usefulness of surgical gowns and exhaust suits with regards to barrier function and protection afforded to healthcare workers from blood strike-through, splashes and aerosols. PATIENTS AND METHODS: We have performed a comfort assessment comparison between the Charnley exhaust suit, disposable gown plus visor and the Stryker Steri-Shield system using a newly developed objective multidimensional ergonomic tool designed to measure wearable comfort across the dimensions of emotion, attachment, harm, perceived change, movement and anxiety. RESULTS: The total mean Comfort Rating Scale value for a disposable gown plus visor was 16.1 with a mean dimensional score of 2.7 (range, 0.2-8.4), for the Charnley system the values were 51.4 and 8.6 (range, 5.9-12.8), respectively, and for the Stryker Steri-Shield 15.4 and 2.6 (range, 0.8-5.6). CONCLUSIONS: The Steri-Shield system provides the least variation in comfort and, as such, may offer the best combination of comfort, protective qualities and form or style of personal protection equipment for lower limb arthroplasty operations.

Anxiety↗

PubMed2005

Prediction of Charnley femoral stem aseptic loosening by early post-operative radiological features.

We describe the association between immediate post-operative radiological appearances and early aseptic failure of total hip replacement. Sixty-three hips were entered into the aseptic failure group and 138 into the control group. Alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was associated with failure in Gruen zones 6 (p=0.040) and 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). Grade of cementation was associated with failure for Barrack grades C (p=0.001) and D (p=0.001). This study has demonstrated that easily applied radiological criteria can be used to identify 'hip arthroplasties at risk' from the immediate post-operative radiograph.

Aged↗

PubMed2005

Primary total knee replacement: a comparison of a nationally agreed guide to best practice and current surgical technique as determined by the North West Regional Arthroplasty Register.

INTRODUCTION: In 1999, a statement of best practice in primary total hip replacement was approved by the Council of the British Orthopaedic Association (BOA) and by the British Association for Surgery of the Knee (BASK) to provide a basis for regional and national auditable standards: we have compared practice in the North West of England to this document to ascertain adherence to this guide to best practice. MATERIALS AND METHODS: A direct comparison of data held on the North West Hip Arthroplasty Register for 2001/2002 and BASK/BOA guidelines was performed. 86 surgeons from 26 hospitals were included in the study. RESULTS: A mean of 93.3% of operations were performed in the surgeon's usual theatre. All of these theatres had vertical laminar air flow systems. 42.2% of respondents routinely used exhaust suits and 68.1% of respondents routinely used impermeable disposable gowns. All surgeons use some form of anti-thromboembolic prophylaxis; 66.2% use a combination of both mechanical and chemical means. All surgeons used antibiotic prophylaxis. The most popular choice of antibiotic was a cephalosporin. 93.7% of surgeons routinely use antibiotic-loaded cement. The PFC and Kinemax prostheses were the most commonly used prostheses. Interestingly, 97.7% of all first-choice implants were cemented. Only 2 surgeons used uncemented total knee replacement. 69.8% of surgeons used a posterior cruciate retaining design. A midline longitudinal skin incision is used by 87.2% of surgeons, a medial longitudinal skin incision by 7.0% and a lateral longitudinal skin incision by 5.8% of surgeons. A medial parapatellar capsular incision is preferred by 91.9% with the remainder using mid vastus or trivector retaining capsulotomy. Closure of capsulotomies is performed in flexion by 65.1% and in extension by 34.9%. In patients with osteoarthritis, 38.4% routinely resurfaced the patella, 34.9% never resurfaced the patella and 26.7% selectively resurfaced. This was in direct contrast to practice for patients with rheumatoid arthritis in whom 66.3% routinely resurfaced the patella, 22.1% never resurfaced the patella and 11.6% selectively resurfaced. DISCUSSION AND CONCLUSIONS: This study has demonstrated variation of practice in hip arthroplasty across the North West region and significant divergence from the BASK/BOA statement of best practice. The introduction of a properly funded national arthroplasty register will surely help to clarify the effect of such diverse practice on patient outcome.

Antibiotic Prophylaxis↗

PubMed2004

Early aseptic loosening of cemented total hip arthroplasty: the influence of non-steroidal anti-inflammatory drugs and smoking.

The purpose of this study was to investigate whether the clinical variables of non-steroidal anti-inflammatory drugs (NSAID) usage and cigarette smoking are possibly linked to aseptic loosening around total hip arthroplasty (THA). We performed a retrospective review of the records and radiographs of 224 patients attending for follow-up at Wrightington Hospital between August 2002 and 2003 who had undergone THA. The following information was recorded: age, gender, primary and revision surgery details, radiographic parameters, smoking history and NSAID usage history. Logistic regression analysis was used to determine if there is any statistically significant association between NSAID usage or smoking habit and aseptic loosening. No such association was found.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2004

Primary total hip replacement: a comparison of a nationally agreed guide to best practice and current surgical technique as determined by the North West Regional Arthroplasty Register.

BACKGROUND: In 1999, a statement of best practice in primary total hip replacement was approved by the Council of the British Orthopaedic Association (BOA) and by the British Hip Society (BHS) to provide a basis for regional and national auditable standards. We have compared practice in the North West Region of England to this document to ascertain adherence to this guide to best practice. METHODS: A total of 86 surgeons from 26 hospitals were included in a questionnaire study. RESULTS: A mean of 93.3% of operations were performed in the surgeon's usual theatre. All of these theatres had vertical laminar air flow systems. Of respondents, 42.2% routinely used exhaust suits, 68.1% routinely used impermeable disposable gowns, and 26.1% used impermeable re-usable gowns. The Charnley femoral and acetabular prostheses were the most commonly used prostheses. All surgeons used some form of anti-thromboembolic prophylaxis: 66.2% use a combination of both mechanical and chemical means. All surgeons used antibiotic prophylaxis. The most popular choice of antibiotic was a cephalosporin--70.7% used a 3-dose regimen over 24 h, 2.6% of surgeons continued antibiotic prophylaxis for 48 h after surgery, and 93.7% of surgeons routinely use antibiotic-loaded cement. All surgeons routinely cleaned, irrigated and dried the acetabulum and femur before cement insertion. Only one surgeon did not use any form of femoral canal occlusion. 69.4% used an intramedullary bone block. Retrograde filling of the femoral shaft by means of a cement gun was practised by 65.1%. CONCLUSIONS: This study has demonstrated considerable variation of practice in total hip arthroplasty across the North West Region and significant divergence from the statement of best practice approved by the BOA and BHS. The introduction of a properly funded national hip register will surely help to clarify the effect of such diverse practice on patient outcome. We would recommend that all trusts locally audit their practices and correlate them with these nationally agreed guidelines.

Antibiotic Prophylaxis↗

PubMed2004

Factors affecting rates of infection and nonunion in intramedullary nailing.

We report a retrospective study over five years to determine the incidence of infection and nonunion after intramedullary nailing in fractures of 214 long bones; 122 femoral, 75 tibial and 17 humeral. The indications for nailing were trauma (n = 161), pathological fracture (n = 30) and nonunion (n = 23). There were 30 open fractures. The overall rates of deep infection and nonunion were 3.8% and 14.2%, respectively. Using multiple logistic regression analysis, we determined the relationships between deep infection and nonunion and the pre- and peri-operative factors of age, ASA score, indication for nailing, the use of reaming, the use of antibiotics, whether the fracture was open and the operating time. Open fractures were found to be significantly associated with deep infection. The length of the operation may also affect the outcome. Opening of the fracture at the time of surgery and the ASA score were found to be significantly associated with the development of nonunion after intramedullary nailing. We have compared our findings with previously published data from large teaching hospital units.

Adolescent↗

PubMed2003

Current spinal board usage in emergency departments across the UK.

The spinal board is widely used as a means of extrication and efficient transport during the pre-hospital phase of trauma management. A number of concerns have been raised regarding its subsequent usage once the patient arrives in the emergency department. We undertook a telephone study of 100 A+E departments in the United Kingdom to ascertain current spinal board usage. Our study demonstrated great variability in practice across the UK and a marked lack of on-going audit or defined protocols governing spinal board usage following the pre-hospital phase of trauma management.

Ambulances↗