Design and Development Towards a Novel Prosthesis for Total Shoulder Arthroplasty to Reduce Aseptic Glenoid Loosening

Total shoulder arthroplasty (TSA) is the most common surgical solution, that helps in restoring the structural and functional integrity of a diseased glenohumeral (GH) joint with intact rotator-cuff. A 300% increase in the usage of TSA has been observed since 2007, along with 2.5% increase in revision rate. Aseptic glenoid loosening accounts for 37% of postsurgical failures in TSA. Eccentric loading of the prosthetic glenoid cup, leading to the “rocking horse” effect, is one of the prevalent causes of aseptic glenoid loosening. Current anatomical total shoulder prosthesis (ATSP) geometry does not consider all the GH morphometric features, for example the elliptical shape of the humeral head. Moreover, the morphometric studies leading to the initial ATSP design did not consider the GH morphology of any sub-Saharan population. Hence, there exists a gap in understanding of the implications of certain morphometric features on the functionality of a post-TSA GH joint. This thesis had two primary aims to address this gap in knowledge. Firstly, to study the GH morphometric variations between cohorts representing native European (Swiss) and native sub-Saharan (South African) populations. Secondly, to develop anatomically inspired ATSP design concepts and test them using biomechanical and finite element (FE) models, insilico, under standardised testing protocols. The morphometric analysis suggested that an average Swiss humeral head radius of curvature was larger (P28mm or <19mm. Considering both the populations, the inherent shape of an average humeral head was found to be elliptical. The thickest region of the head was found to lie in the posterior region and not at the geometric center. Hertzian contact theory was applied to calculate the GH stresses produced by symmetric and asymmetric elliptical heads. Higher concentric stresses (P<0.001), within the acceptable limit for polyethylene, were observed to be imparted by the asymmetric heads. Population-specific musculoskeletal models were developed to study the post-TSA kinematic variation. When an identical range of motion (RoM) was performed by these models, population-specific variation in muscle moment arms was observed. The novel glenoid designs were not found to alter the post-surgical kinematics. FE models of the biradial, compartmental and pear-shaped glenoid implant designs were subjected to compressive and shear loading according to the American Society for Testing and Materials (ASTM). Using the bi-radial the glenoid cup, with thickened posterior-superior surface, anatomically relevant force distribution patterns could be replicated. Compartmentalising the glenoid prosthesis into concentric and eccentric regions with the gaps, proved to be highly beneficial. When compared to a commercially available glenoid prosthesis, the compartmental prosthesis was able to contain the GH forces to the concentric region for longer, delaying the eccentric loading and therefore potentially reducing the “rocking horse” effect. In the light of the above observations, two conclusions can be drawn from this thesis. Firstly, it would be beneficial if population-specific ATSP were made available for natives of certain geographic locations. Secondly, glenoid prosthesis designs could be compartmentalised to contain the GH joint forces within the concentric regions of the cup which might aid in the reduction of post-TSA complications

The management of acute knee dislocations: A global survey of orthopaedic surgeons' strategies.

PURPOSE: Great variety and controversies surround the management strategies of acute multiligament knee injuries (aMKLIs) and no established guidelines exist for resource-limited practices. The aim of this study was to compare the management approach of acute knee dislocations (AKDs) by orthopedic surgeons from nations with different economic status. METHODS: This descriptive cross-sectional scenario-based survey compares different management strategies for aMLKIs of surgeons in developed economic nations (DEN) and emerging markets and developing nations (EMDN). The main areas of focus were operative versus non-operative management, timing and staging of surgery, graft choice and vascular assessment strategies. The members of the Societe Internationale de Chirurgie Orthopedique et de Traumatologie (SICOT) were approached to participate and information was collected regarding their demographics, experience, hospital setting and management strategies of aMLKIs. These were analyzed after categorizing participants into DEN and EMDN based on the gross domestic product (GDP) per capita. RESULTS: One-hundred and thirty-eight orthopedic surgeons from 47 countries participated in this study, 67 from DEN and 71 (51.4%) from EMDN. DEN surgeons had more years of experience and were older (p < 0.05). Surgeons from EMDN mostly worked in public sector hospitals, were general orthopedic surgeons and treated patients from a low-income background. They preferred conservative management and delayed reconstruction with autograft (p < 0.05) if surgery was necessary. Surgeons from DEN favored early, single stage arthroscopic ligament reconstruction. Selective Computerized Tomography Angiography (CTA) was the most preferred choice of arterial examination for both groups. Significantly more EMDN surgeons preferred clinical examination (p < 0.05) and duplex doppler scanning (p < 0.05) compared to DEN surgeons. More surgeons from EMDN did not have access to a physiotherapist for their patients. CONCLUSIONS: Treatment of aMLKIs vary significantly based on the economic status of the country. Surgeons from DEN prefer early, single stage arthroscopic ligament reconstruction, while conservative management is favored in EMDN. Ligament surgery in EMDN is often delayed and staged. EMDN respondents utilize duplex doppler scanning and clinical examination more readily in their vascular assessment of aMLKIs. These findings highlight very distinct approaches to MLKIs in low-resource settings which are often neglected when guidelines are generated

A narrative review of treatment strategies for major glenoid defects during primary reverse shoulder arthroplasty, with a focus on the use of structural bone graft

Structural glenoid defects are common during primary reverse shoulder arthroplasty (RSA) and are often associated with poor outcomes. The lack of pre-operative imaging protocols for determining the depth and degree of glenoid wear hinders our ability to accurately plan and correct these defects. Although bone grafting has been reported to be effective in reducing glenoid wear during RSA, there is limited information on when to utilise it and how to prepare the graft. We conducted this review to assess the evidence for the management of glenoid defects, with an emphasis on bone grafts to treat structural glenoid bone loss in primary RSA patients

Clinical outcomes of children using a metered dose inhaler with a sleeve attachment device to improve ease of use

Background: Activating pressurized metered dose inhalers (pMDIs) is often challenging for children. The Easy Squeezy (ES) is a novel sleeve attachment device that reduces activation force by 3 times. Although users have favored using the ES over using a pMDI alone, the clinical impact of the ES remains unknown. The aim of this study was to compare lung function and quality of life between ES users and users of a pMDI alone. Objectives: Our aim was to measure and compare lung function of asthmatic children after they used the ES and pMDI alone. Methods: In this crossover study we recruited 65 asthmatic children between the ages of 5 and 12 years. The participants were randomized into 2 groups. One of the groups used the ES for 6 weeks whereas the other group used a pMDI. After 6 weeks the participants crossed over to the other group. Lung function test parameters were measured after randomization and after each 6 weeks of device use. Quality of life (measured by the Patient Asthma Quality of Life Questionnaire [PAQLQ]) and Childhood Asthma Control Test were measured after each period of device use. Results: There was no significant difference in the baseline lung function between the groups. The ES group had a significantly lower percentage difference between prebronchodilator and postbronchodilator FEV1 values. Although no significant differences were observed in PAQLQ scores between the groups, more patients in the ES group had improvement of their PAQLQ score than did patients in the group using a pMDI alone. Total Childhood Asthma Control Test scores were significantly higher for the ES group. Conclusions: The ES device may allow users’ asthma to be better controlled than by using a pMDI alone

Quantitative fit analysis of acromion fracture plating systems using three-dimensional reconstructed scapula fractures – A multi-observer study

Introduction: Surgical treatment of displaced acromial and scapula spine fractures may be challenging due to the bony anatomy and variable fracture patterns. This difficulty is accentuated by the limitations of the available scapular plates for fracture fixation. This study compares the quantitative fitting of anatomic scapular plates and clavicle plates, using three-dimensional (3D) printed fractured scapulae. Methods: Fourteen scapulae with acromion and spine fractures were used for this study. Computerized tomographic (CT) scans of the fractured scapulae were obtained from the Philips picture archiving and communication system (PACS) database of patients admitted to a tertiary teaching hospital in Cape Town, South Africa between 2012 and 2016. The reconstructed scapulae were 3D printed and the anatomical acromion and clavicle plates were templated about the fracture regions. The fit assessment was performed by five observers who classified the plates as no-fit, intermediate fit, and anatomical fit according to the surgical guidelines. Results: The 6-hole anterior clavicle plate performed better than any of the scapular plates as they were able to fit 45.7% of the fractured acromion, including the spine. Among the pre-contoured anatomical scapula plates, both the short and the long acromion plates could fit only 27.3% of the fractured acromion. The intraclass correlation coefficient was 0.965 suggesting excellent consensus among the five observers. Conclusion: Clavicle plates were found to be better suited to fit around a scapula fracture in its acromion and spine region

The correlation between clinical and radiological severity of osteoarthritis of the knee

Introduction: Primary osteoarthritis (OA) is a common cause of knee pain. Appropriate management of knee OA is based on clinical and radiological findings. Pain, deformity, and functional impairments are major clinical factors considered along with radiological findings when making management decisions. Differences in management strategies might exist due to clinical and radiological factors. This study aims at finding possible associations between clinical and radiological observations. Methods: A prospective cross-sectional study of 52 patients with primary osteoarthritis of the knee managed conservatively at a tertiary hospital arthroplasty clinic was conducted for three months. English speaking patients with primary OA were identified and included in this study. Pain and functional impairment were assessed using Wong-Baker Faces pain scale, The Knee Society Score (KSS), and Western Ontario and McMaster Osteoarthritis Index (WOMAC). The Body Mass Index (BMI) of all participants was measured. Standard two views plain radiographs were used for radiographic grading of the OA. Anonymized radiographs were presented to two senior consultant orthopaedic surgeons who graded the OA using Kellgren and Lawrence (KL) and Ahlbäck classification systems. The severity of the functional impairment and pain score was then compared to the radiological grading. Results: The average age of our participants was 63 ± 9 years. Their average BMI was 34.9 ± 8.4 kg/m2, median self-reported pain, total WOMAC, and pain WOMAC scores were 8, 60, and 13, respectively. We observed no significant correlation between BMI and pain scores. Inter-rater reliability for KL and Ahlbäck grading was strong. There was no significant correlation between WOMAC scores and the radiological grades. Conclusion: There was no correlation between pain and functional scores, patient factors and radiological severity of OA of the knee

The Association of Variants within Types V and XI Collagen Genes with Knee Joint Laxity Measurements

Joint laxity is a multifactorial phenotype with a heritable component. Mutations or common polymorphisms within the &alpha;1(V) (COL5A1), &alpha;1(XI) (COL11A1) and &alpha;2(XI) (COL11A2) collagen genes have been reported or proposed to associate with joint hypermobility, range of motion and/or genu recurvatum. The aim of this study was to investigate whether polymorphisms within these collagen-encoding genes are associated with measurements of knee joint laxity and computed ligament length changes within the non-dominant leg. One hundred and six healthy participants were assessed for genu recurvatum (knee hyperextension), anterior-posterior tibial translation, external-internal tibial rotation and ligament length changes during knee rotation of their non-dominant leg. Participants were genotyped for COL5A1 rs12722 (T/C), COL11A1 rs3753841 (C/T), COL11A1 rs1676486 (T/C) and COL11A2 rs1799907 (A/T). The genotype-genotype combination of any two or more of the four COL5A1 rs12722 CC, COL11A1 rs3753841 CC, COL11A1 rs1676486 TT and COL11A2 rs1799907 AA genotypes was associated with decreased active and passive knee hyperextension. These genotype-genotype combinations, including sex (male), increased age and decreased body mass collectively, also contributed to decreased passive knee hyperextension. These findings suggest that COL5A1, COL11A1 and COL11A2 gene-gene interactions are associated with knee hyperextension measurements of the non-dominant leg of healthy individuals