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Bone & Joint Open
Vol. 2, Issue 10 | Pages 850 - 857
19 Oct 2021
Blankstein AR Houston BL Fergusson DA Houston DS Rimmer E Bohm E Aziz M Garland A Doucette S Balshaw R Turgeon A Zarychanski R

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Methods

We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 39 - 39
1 Mar 2021
Aziz M Rosenzweig D Weber M
Full Access

Great strides have been made in the early detection and treatment of cancer which is resulting in improved survivability and more Canadians living with cancer. Approximately 80% of primary breast, lung, and prostate cancers metastasize to the spine. Poly-methyl methacrylate (PMMA) bone cement is one of the most commonly used bone substitutes in spine surgery. In clinical practice it can be loaded with various drugs, such as antibiotics or chemotheraputic drugs, as a means of local drug delivery. However, studies have shown that drugs loaded into PMMA cement tend to release in small bursts in the first 48–72 hours, and the remaining drug is trapped without any significant release over time. The objective of this study is to develop a nanoparticle-functionalized PMMA cement for use as a sustained doxorubicin delivery device. We hypothesize that PMMA cement containing mesoporous silica nanoparticles will release more doxorubicin than regular PMMA.

High viscosity SmartSet ™ PMMA cement by DePuy Synthes was used in this study. The experimental group consisted of 3 replicates each containing 0.24 g of mesoporous silica nanoparticles, 1.76 g of cement powder, 1ml of liquid cement monomer and 1 mg of doxorubicin. The control group consisted 3 replicates each containing 2.0 g of cement powder, 1ml of liquid cement monomer and 1 mg of doxorubicin. The experimental group contained an average of 8.18 ± 0.008 % (W/W) mesoporous silica nanoparticles. Each replicate was casted into a cylindrical block and incubated in a PBS solution which was changed at predetermined intervals for 45 days. The concentration of eluted doxorubicin in each solution was measured using a florescent plate reader. The mechanical properties of cement were assessed by unconfined compression testing. The effect of the doxorubicin released from cement on prostate and breast tumor cell metabolic activity was assessed using the Alamar Blue test.

After 45 days the experimental group released 3.24 ± 0.25 % of the initially loaded doxorubicin which was more than the 2.12 ± 0.005% released by the control group (p 0.03). There was no statistically significant difference in Young's elasticity modulus between groups (p 0.53). Nanoparticle functionalized PMMA suppressed the metabolic activity of prostate cancer by more than 50 percent but did not reach statistical significance. Nanoparticle functionalized PMMA suppressed the metabolic activity of breast cancer cells by 69 % (p < 0.05).

Nanoparticle-functionalized PMMA cement can release up to 1.53 times more doxorubicin than the standard PMMA. The use of mesoporous silica nanoparticles to improve drug release from PMMA cement shows promise. In the future, in vivo experiments are required to test the efficacy of released doxorubicin on tumor cell growth.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 81 - 81
1 Jul 2020
Aziz M Jarzem PF McIntosh G Weber M
Full Access

Seniors make up 16.9 percent of the Canadian population. Furthermore, the number of Canadians who are 65 years or older is increasing at an average rate of 20 percent every 5 years. In 2017, Sing etal reported that there is an increasing number of patients undergoing degenerative scoliosis surgery with the largest increase attributed to patients aged 65–69 years followed by those aged 70–74 years. Therefore, the purpose of this study is to assess the effectiveness of undergoing spinal surgery to correct degenerative spinal scoliosis in the ever-growing number of elderly patients. We hypothesize that age is not an independent prognostic factor of patients' outcomes followings degenerative scoliosis surgery.

A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. ANOVA was used to analyze continuous variables while Chi Square test was used to analyze categorical variables. Significance level was p < 0.05.

There were 165 patients identified from the registry who met the inclusion criteria, 94 patients (57 %) were female. There were 102 (61.8 %) patients who were 65 years or older. The overall average age was 66.6 years (range 35–84, SD 8.6). There were 27 intra-operative complications, 44 peri-operative complications and 18 post operative complications. There was no statistically significant difference between the two age groups with regards to risk of developing intra-operative, perioperative and post operative complications. Patients who underwent degenerative scoliosis surgery reported an average improvement of 2.95±3.32, 3.64±3.50, 16.84±20.44 points on the back-pain scale, leg pain scale and the Oswestry Disability Index (ODI) respectively, there was no statistically significant differences in these measures between the two age groups.

As the number of patients undergoing degenerative scoliosis surgery increases, clinicians will need to determine which factors will significantly impact patients' outcomes following surgery. This study shows that age is not an independent prognostic factor when it comes to patients' outcomes following degenerative scoliosis surgery. In the future, research should examine the impact of age in conjunction with factors such as frailty, comorbidities and functional status on patient outcomes.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 80 - 80
1 Jul 2020
Aziz M McIntosh G Johnson MG Fisher CG Weber M Goytan M
Full Access

Post-operative infection is a serious complication of spine surgery and can contribute to the strain on the healthcare system's resources. The purpose of this study is to determine what factors affect the risk of developing postoperative infection. We hypothesize that female gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, increased age, body mass index (BMI), American Society of Anaesthesiologists (ASA) score, blood loss, number of operative levels, operative time and undergoing non-elective surgery will increase the patients' risk of developing a post-operative infection.

A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. Multivariable logistical regression analysis was conducted (odds ratios) to determine any association between the outcome and independent factors. Significance level was p < 0.05.

There were 7747 patients identified from the registry that had completed at least 12 weeks of follow up. There were 199 infections recorded representing a 2.6% risk of infection. There were no association found between the risk of developing a post operative infection and gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, ASA score, blood loss, number of operative levels and undergoing non-elective surgery. The following were associated with an increased risk of developing a post operative infection: Older age (adjusted OR=1.021, 95% CI=1.005–1.038, p < 0 .05), having an elevated BMI (adjusted OR=1.042, 95% CI=1.013–1.072, p < 0 .005), longer operative time (adjusted OR=1.002, 95% CI=1.001–1.004, p < 0 .001).

There is a 2.6% overall rate of post-operative spine infection across 20 Canadian centres. The factors that were associated with an increased risk of developing a post operative-infection were older age, increased BMI and longer operative time. This study establishes a benchmark against which the effectiveness of future interventions to reduce infection can be compared.