Background Displaced acromial fractures are challenging to treat. Complex bony anatomy, variable fracture morphology and limitations of available implants present challenges in achieving favourable surgical outcomes. We determined to what extent currently available scapular and clavicular plating systems are able to provide adequate fixation options. Methods Patients presenting to an urban trauma centre with acromial fractures sustained from blunt trauma between 2012 and 2016 were identified (n = 15, 14M / 1F). The fracture patterns were categorized according to location (Type I = 13%, Type II = 27%, Type III = 60%). Computed Tomography (CT) scans were reconstructed to produce three-dimensional (3D) printed anatomical models on which a quantitative fit analysis was performed. Measurements were performed twice, by five separate observers, with fit graded as anatomical fit (< 2mm), intermediate fit (> 2mm) or no-fit. Results The anterior clavicle 6 hole plate fitted best in 45.7% of cases. Acromial plates only achieved 27.3%. The acromion short plate together with the lateral clavicle short plates performed the best in Type II fractures. An inter-observer intraclass correlation coefficient (ICC) agreement of 0.974 was obtained. Conclusion The available commercial acromial plating system fails to provide adequate congruency and fit for fixation. Clavicular plates were superior alternative implants. 3D printed anatomical models can be used effectively to assist in templating implants preoperatively.

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Purpose: We aimed to assess functional and clinical outcomes of patients who underwent open reduction and internal fixation of distal intra-articular fractures of the humerus through a previously undescribed approach through the triceps tendon called the Triceps-Off, Transfascial Sleeve (TOFS) approach. Method: We conducted an Ambispective cohort study of 10 patients who underwent open reduction and internal fixation of the distal humerus through the TOFS approach at a tertiary hospital between March 2016 and January 2019. Patients were identified from the prospectively kept surgical database. All had AO type C fractures of the distal humerus. The mean age was 36.7 ± 14.9 years (range 19 to 68). The assessment consisted of a review of their hospital records, range of motion, triceps strength, ultrasound evaluation of triceps tendon integrity, X-rays for union rates and adequacy of reduction, and DASH scores. Results: The mean time of follow up was 10.8 ± 4.7 months (range 6 to 19). The mean arc of motion was 114.7 ± 25.1 degrees (range 80 to 150 degrees). There was a decrease in mean triceps muscle strength compared to the uninjured side; 66% at 45 degrees of flexion, 70% at 90 degrees and 86% at 120 degrees of elbow flexion. The mean DASH score was 15.7 ± 8.9 indicating mild residual impairment (range 5 to 31). The DASH score had a strong correlation (r = 0.71; p<0.05) with the follow-up period. All tendons were intact on ultrasound evaluation. One patient had deep surgical site infection, treated with surgical debridement, antibiotics and plate removal with resolution of sepsis and healing. All fractures united by 6 months. Conclusion: TOFS is a successful surgical approach for reduction and fixation of AO Type C intra-articular distal humerus fractures, with excellent tendon healing rates. It is however, associated with mild residual functional impairment and residual triceps weakness.

Bone drilling is a major part of modern orthopaedic surgery associated with the principles of internal fixation of fractured bones. At present, information related to drilling forces, rate of drill bit penetration and drill bit rotational speed is not available to orthopaedic surgeons, clinicians and researchers as bone drilling is performed manually. This research demonstrates that orthopaedic surgery involving the drilling of bone can greatly benefit from the technology of automation/ mechatronics, which allows the collection and storage of the drilling data for analysis as well as for the improvement of the drilling procedure. The research also represents a significant contribution to the development of a drilling system for the enhancement of safety and/or as a diagnostic tool for the evaluation of bone strength. A novel automated experimental rig, which enables drilling tests to be carried out in a controlled environment, has been developed. The investigation for the enhancement of safety involves the detection of drill bit break-through on a femoral shaft in the presence of system compliance and inherent fluctuation of drilling forces. Since these two factors affect the detection of drill bit break-through, a robust and reliable method based on a modified Kalman filter has been developed. When applied to the force difference between successive samples and the rotational speed, the modified Kalman filter has been found to be very effective in establishing trends and ironing out major fluctuations caused by the system compliance and inherent drilling force fluctuation. The evaluation of bone strength related to the cancellous bone at the proximal femur has resulted in the establishment of a positive relationship between the average drilling force and bone mineral density (BMD), obtained from bone densitometry, which is used to estimate bone strength in clinical practice. The correlation has been found to depend on the direction of drilling. This is indicated by a linear relationship obtained in the anterior-posterior direction (perpendicular to the cervical axis), which is not interchangeable with the relationship in the direction of the cervical axis. Findings of this research have indicated that analysis of bone drilling forces has the potential to provide additional information about the strength of bone.

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2D-3D registration is one of the underpinning technologies that enables image-guided intervention in computer-assisted orthopaedic surgery (CAOS). Preoperative 3D images and surgical plans need to be mapped to the patient in the operating room before they can be used to augment the surgical intervention, and this task is generally fulfilled by using 2D-3D registration which spatially aligns a preoperative 3D image to a set of intraoperative fluoroscopic images. The key problem in 2D-3D registration is to define an accurate similarity metric between the 2D and 3D data, and choose an appropriate optimization algorithm. Various similarity metrics and optimization algorithms have been proposed for 2D-3D registration; however, current techniques have several critical limitations. First, a good initial guess - usually within a few millimetres from the true solution - is required, and such capture range is often not wide enough for clinical use. Second, for currently used optimization algorithms, it is difficult to achieve a good balance between the computation efficiency and registration accuracy. Third, most current techniques register a 3D image of a single bone to a set of fluoroscopic images, but in many CAOS procedures, such as a multi-fragment fracture treatment, multiple bone pieces are involved. In this thesis, research has been conducted to investigate the above problems: 1) two new registration techniques are proposed that use recently developed optimization techniques, i.e. Unscented Kalman Filter (UKF) and Covariance Matrix Adaptation Evolution Strategy (CMA-ES), to improve the capture range for the 2D-3D registration problem; 2) a multiple-object 2D-3D registration technique is proposed that simultaneously aligns multiple 3D images of fracture fragments to a set of fluoroscopic images of fracture ensemble; 3) a new method is developed for fast and efficient construction of anatomical atlases; and 4) a new atlas-based multiple-object 2D-3D registration technique is proposed to aid fracture reduction in the absence of preoperative 3D images. Experimental results showed that: 1) by using the new optimization algorithms, the robustness against noise and outliers was improved, and the registrations could be performed more efficiently; 2) the simultaneous registration of multiple bone fragments could achieve a clinically acceptable global alignment among all objects with reasonable computation cost; and 3) the new atlas construction method could construct and update intensity atlases accurately and efficiently; and 4) the use of atlas in multiple-object 2D-3D registration is feasible. / Thesis (Ph.D, Computing) -- Queen's University, 2011-09-28 10:58:04.406

Osteoarthritis (OA) is the most common degenerative joint disease, affecting primarily the hip, knee, and hand (Ip 2005). OA of the knee and hip is the 11th highest contributor to global disability (Cross et al. 2014). Hip OA is diagnosed using radiographs, computed tomography (CT), and/or magnetic resonance imaging (MRI). Hip OA affects the whole hip joint, causing pain and reduced range of motion (Altman et al. 1991). The cause of pain in OA is not well understood, but it may be attributed to abnormal growth of blood vessels and nerves in the subchondral bone of the femoral head (Kumar et al. 2013). Quantifying blood vessels and nerves and correlating their presence with diagnostic techniques such as MRI will establish a relationship between femoral head degeneration and pain levels and current diagnostic signs. The aims of this study were: (1) to develop a reproducible histological technique to identify blood vessels and nerves in bone sections; and (2) to apply this protocol to identify blood vessel and nerve characteristics within osteoarthritic femoral heads. Femoral heads were retrieved from 8 OA patients (age range: 40-76; 5 female and 3 male) undergoing total hip replacement surgery. Each sample was evaluated for the presence of subchondral bone cysts using micro-computed tomography (µCT), then regions containing cysts were isolated and dissected for histological processing. Different fixation times in paraformaldehyde (PFA) were tested in three samples to assess the effect of fixation time on binding of the primary antibody to the target. Samples were stained with hematoxylin and eosin to evaluate overall tissue morphology, safarin-O and fast green to visualize the integrity of articular cartilage, anti-CD31 to identify vascular endothelium, and anti-PGP 9.5 to identify peripheral nerve fibers. A protocol was successfully developed to identify CD31-positive blood vessels and PGP 9.5-positive nerves in osteoarthritic femoral heads. The immunohistochemistry protocols for staining with anti-CD31 and anti-PGP 9.5 were optimized for maximum intensity of target staining, minimal background staining, and minimal artefactual tissue folding. Fixation time in PFA was not found to have an effect on quality of staining with anti-CD31. Blood vessels were found in all eight of the samples collected, and peripheral nerves were found in five of the samples. Special attention was paid to regions with fibrous subchondral bone cysts, because these are the most likely type to undergo neurovascular invasion. Out of the five samples with fibrous subchondral bone cysts, blood vessels were identified in all five cyst regions, and peripheral nerves were identified in three cyst regions. Using the protocols developed in this study, blood vessels and nerves were found in osteoarthritic femoral heads. In future, a larger sample set will be used to correlate the nature of blood vessel density and nerves that are found in bone marrow lesions identified on MRI scans obtained before surgery and are associated with bone cysts. This is an important step towards identifying more effective treatments for OA that address the specific underlying causes and the development of non-treatable pain.