Adequate visual clarity is paramount to performing arthroscopic shoulder surgery safely, efficiently, and effectively. The addition of epinephrine in irrigation fluid, and the intravenous or local administration of tranexamic acid (TXA) have independently been reported to decrease bleeding thereby improving the surgeon's visualization during arthroscopic shoulder procedures. No study has compared the effect of systemic administered TXA, epinephrine added in the irrigation fluid or the combination of both TXA and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. The purpose of this study is to determine if intravenous TXA is a safe alternative to epinephrine delivered by a pressure-controlled pump in improving arthroscopic shoulder visualization during arthroscopic procedures and whether using both TXA and epinephrine together has an additive effect in improving visualization.

The design of the study was a double-blinded, randomized controlled trial with four 1:1:1:1 parallel groups conducted at one center. Patients aged ≥18 years undergoing arthroscopic shoulder procedures including rotator cuff repair, arthroscopic biceps tenotomy/tenodesis, distal clavicle excision, subacromial decompression and labral repair by five fellowship-trained upper extremity surgeons were randomized into one of four arms: Pressure pump-controlled regular saline irrigation fluid (control), epinephrine (1ml of 1:1000) mixed in irrigation fluid (EPI), 1g intravenous TXA (TXA), and epinephrine and TXA (EPI/TXA). Visualization was rated on a 4-point Likert scale every 15 minutes with 0 indicating ‘poor’ quality and 3 indicating ‘excellent’ quality. The primary outcome measure was the unweighted mean of these ratings. Secondary outcomes included mean arterial blood pressure (MAP), surgery duration, surgery complexity, and adverse events within the first postoperative week.

One hundred and twenty-eight participants with a mean age (± SD) of 56 (± 11) years were randomized. Mean visualization quality for the control, TXA, EPI, and EPI/TXA groups were 2.1 (±0.40), 2.1 (±0.52), 2.6 (±0.37), 2.6 (±0.35), respectively. In a regression model with visual quality as the dependent variable, the presence/absence of EPI was the most significant predictor of visualization quality (R=0.525; p < 0 .001). TXA presence/absence had no effect, and there was no interaction between TXA and EPI. The addition of MAP and surgery duration strengthened the model (R=0.529; p < 0 .001). Increased MAP and surgery duration were both associated with decreased visualization quality. When surgery duration was controlled, surgery complexity was not a significant predictor of visualization quality. No adverse events were recorded in any of the groups.

Intravenous administration of TXA is not an effective alternative to epinephrine in the irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries although its application is safe. There is no additional improvement in visualization when TXA is used in combination with epinephrine beyond the effect of epinephrine alone.

Ulnar shortening osteotomy (USO) is a procedure performed to alleviate ulnar sided wrist pain caused by ulnar impaction syndrome (UIS) and/or triangular fibrocartilage complex (TFCC) injury. Presently, non-union rates for ulnar shortening osteotomy is quoted to be 0–18% in the literature. However, there is a dearth of literature on the effect of site of osteotomy and plate placement on the rate of complications like a delayed union, symptomatic hardware and need for second surgery for hardware removal. In this study, we performed a multi-centered institutional review of ulnar shortening osteotomies performed, focusing on plate placement (volar vs. dorsal) and osteotomy site (distal vs. proximal) and determining if it plays a role in reducing complications.

This study was a multi-centered retrospective chart review. All radiographs and charts for patients that have received USO for UIS or TFCC injury between 2013 and 2017 from hand and wrist fellowship-trained surgeons in Calgary, Alberta and Winnipeg, Manitoba were examined. Basic patient demographics including age, sex, past medical history, and smoking history were recorded. Postoperative complications such as delayed union, non-union, infection, chronic regional pain syndrome, hardware irritation requiring removal were evaluated with a two-year follow-up period. Osteotomy sites were analyzed based on the location in relation to the entire length of the ulna on forearm radiographs. Surgical techniques including volar vs. dorsal plating, oblique vs. transverse osteotomy cuts, and plate type were documented.

Continuous variables of interest were summarized as mean or medians with standard deviation or inter-quartile range as appropriate. Differences in baseline characteristics were determined by t-test or one-way ANOVA for continuous variables and chi-square or Fischer exact test for dichotomous variables. All analyses were conducted using SPSS V24.0 (Chicago, IL, USA). All statistical tests were considered significant if p < 0.05.

Between 2013–2017 there were 117 ulnar shortening osteotomies performed. The average age of patients was 46.2 ± 16.2, with 62.4% being female. The mean pre-operative ulnar variance was +3.89 ± 2.17 mm and post-operative ulnar variance was −1.90 ± 1.80 mm. 84.6% of the plates were placed on the volar aspect of the ulna and 14.5% were placed on the dorsal aspect. An oblique osteotomy was made 99.1% of the time. In measuring osteotomy placement, the average placement was made in the distal 1/3 of the ulna. Overall, there was a 40% complication rate. Hardware irritation requiring removal encompassed 23%, non-union 14%, and wound infection covered 0.8%. When comparing dorsal vs volar plating, there was no statistically significant difference for non-union or hardware removal. Similarly, in evaluating osteotomy level, there was no statistical difference between proximal vs distal osteotomy for non-union and hardware removal.

In this multi-centered retrospective review of ulnar shortening osteotomies, we found that there was an overall complication rate of 40%. There was no statistically significant difference in complication rates between dorsal vs volar plate placement or proximal vs distal osteotomy sites. Further studies examining other potential risk factors in lowering the complication rate would be beneficial.

During the pandemic of COVID-19, some patients with COVID-19 may need emergency surgeries. As spine surgeons, it is our responsibility to ensure appropriate treatment to the patients with COVID-19 and spinal diseases. A protocol for spinal surgery and related management on patients with COVID-19 has been reviewed. Patient preparation for emergency surgeries, indications, and contraindications of emergency surgeries, operating room preparation, infection control precautions and personal protective equipments (PPE), anesthesia management, intraoperative procedures, postoperative management, medical waste disposal, and surveillance of healthcare workers were reviewed. It should be safe for surgeons with PPE of protection level 2 to perform spinal surgeries on patients with COVID-19. Standardized and careful surgical procedures should be necessary to reduce the exposure to COVID-19.

Bone metastases are the most common cause of cancer-related pain and often lead to other complications such as pathological fractures and spinal cord compression. Bisphosphonates (BP) are a class of potent anti-resorptive agents commonly prescribed to retard osteoporosis progression. Interestingly, BP may have indirect anti-tumour properties through negative effects on macrophages, osteoclasts, endothelial cells and their ability to suppress matrix metalloproteinase (MMP) activity. Currently, the use of bisphosphonates for cancer therapy is generally restricted to high dose systemic delivery. The purpose of this study was to investigate the effects of direct local delivery of Zoledronate at the metastatic site in a mouse model of breast cancer metastasis to bone.

Seven days following intra-tibial inoculation with MDA-MB-231 (N = 1× 105) breast cancer cells in athymic mice, the experimental group (N = 11) was treated by direct infusion of 2µg of Zoledronate into the tibial lesion (three times/week for three weeks) and compared to vehicle-treated mice (N = 5). The formation of bone metastases and growth of the lesions were followed up by weekly bioluminescence imaging. In a subsequent experiment, a comparison of the effects of local versus systemic delivery of Zoledronate on the formation of osteolytic bone metastases was carried in athymic mice (N = 15). Seven days following intra-tibial inoculation with MDA-MB-231 breast cancer cells, the systemic group (N = 5) was treated with Zoledronate (0.025mg/kg) once per week for four weeks and compared to systemic delivery of vehicle (N = 4). Following treatment, the mice were sacrificed, and micro-CT images of the right tibia were obtained. Bone volume to tissue volume ratio (BV/TV%) was determined using µ-CT biomarkers.

The first experiment showed a statistically significant increase in mean bone volume/tissue volume ratio% (BV/TV%) in the treated group (7.0±1.54%) as compared to the control group (3.8±0.48%) (P <0.001, 95%CI=1.9–4.3). This corresponded to a net increase of 84.21% in response to Zoledronate treatment. Comparison between the local and systemic effects of Zoledronate also revealed a significant increase in the BV/TV% in the locally treated group (6.69±0.62%) when compared to the cohort administered systemic bisphosphonate treatment (4.03±0.44%) (P<0.001, 95%CI=1.24–3.20), corresponding to a net increase of 66.0%.

These preliminary results suggest that high dose sustained release of Zoledronate can lead to a significant inhibition of tumor-induced osteolysis. Moreover, comparison between local and systemic delivery revealed that the effect of local bisphosphonate administration exceeds the benefits of systemic delivery in terms of osteolysis inhibition. Lastly, the noted effects of Zoledronate local delivery triggers the need for further assessment of its anti-tumour activity.

Objective

To investigate the biomechanical mechanism and report preliminary clinical efficacy of eccentric rotational acetabular osteotomy (ERAO) when conduct treatment for developmental dysplasia of the hip (DDH).

Objective

To investigate the biomechanical basis and report preliminary clinical efficacy of eccentric rotational acetabular osteotomy (ERAO) when treating developmental dysplasia of the hip (DDH).

Implant-related infection (IRI) is closely related to the local immunity of peri-implant tissues. The generation of reactive oxygen species (ROS) in activated macrophages plays a prominent role in the innate immune response. In previous studies, we indicated that implant wear particles promote endotoxin tolerance by decreasing the release of proinflammatory cytokines. However, it is unclear whether ROS are involved in the damage of the local immunity of peri-implant tissues. In the present study, we assessed the mechanism of local immunosuppression using titanium (Ti) particles and/or lipopolysaccharide (LPS) to stimulate RAW 264.7 cells. The results indicate that the Ti particles induced the generation of a moderate amount of ROS through nicotinamide adenine dinucleotide phosphate oxidase-1 (NOX-1), but not through catalase. Pre-exposure to Ti particles inhibited ROS generation and extracellular regulated protein kinase (ERK) activation in LPS-stimulated macrophages. These findings indicate that chronic stimulation by Ti particles may lead to a state of oxidative stress and persistent inflammation, which may result in the attenuation of the immune response of macrophages to bacterial components such as LPS. Eventually, immunosuppression develops in peri-implant tissues, which may be a risk factor for IRI.

Osteotomy in spine and skull base surgery is a highly demanding task that requires very high precision. Compared to conventional surgical tools, laser allows contactless hard tissue removal with fewer traumas to the patient and higher machining accuracy. However, a key issue remains unsolved: how to terminate the ablation while the underlying critical soft tissue is reached?

Our research group has realised a closed-loop control of a CO₂-laser osteotomy system under the guidance of an optical coherence tomography (OCT). The OCT provides three-dimensional information about the microstructures beneath the bone surface with a resolution on micrometre scale and an imaging depth of about 0.5 mm. The OCT and CO₂-laser systems are integrated using a coaxial setup and a registration between their working spaces (mean absolute error 19.6 μm) was performed.

The laser ablation and OCT scan are performed in turn. After correction of image distortions and speckle noise reduction, the position of the critical structure can be segmented in the enhanced OCT scans. The laser parameters for the next round of ablation are foresightedly planned based on the overlying residual bone thickness. After patient motion compensation by tracking artificial landmarks in the OCT scans (accuracy: RMS 27.2 μm), the ablation pattern can be precisely carried out by the CO₂-laser. The system was evaluated by performing laser cochleostomy on native porcine cochlea and mean ablation accuracy of 30 μm has been achieved.

However, for narrow incisions that are only several tens of micrometres wide, very few pixels are visible beneath the incision bottom in the OCT and a robust segmentation of the critical structure is impossible. We are now developing a hybrid control system, which monitors the ablation-induced acoustic emission (AE) as a secondary control mechanism in addition to the OCT.

When a pre-defined “switching” depth is reached, the AE-based control module is activated. Instead of analysing the acquired signals with conventional Fourier transform, a wavelet transform-based approach has been developed, which compares the correlation coefficients of the wavelet spectra of successive laser pulses. At the transition from bone tissue to the underlying soft tissue layer, a significant change in the coefficients can be observed, which is regarded as the signal for terminating the ablation. In order to keep the injury to the soft tissue layer to a minimal level, the laser energy is reduced after the switching. Preliminary experiments revealed that the wavelet-based approach is capable of controlling the ablation using pulses with extremely low energy down to 0.04mJ/pulse, resulting in an injured tissue layer of less than 10 μm.

We expect to achieve the ablation accuracy on tens of micrometre scale using the proposed hybrid control mechanism.