A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Medicine in the branch of Orthopaedic Surgery Johannesburg 31 January 2017 / Background Fractures of the radial head are classified according to the Mason System modified by Johnston. The fracture is managed according to its classification. Fractures of the Mason Type III and IV are complex and management is controversial. The early literature regarding the outcome of patients after arthroplasty of fracture dislocation of the elbow is limited by small patient numbers, short-term follow-up, and high complication rates. More recent literature has shown radial head replacement to have better functional outcomes in the short to medium term. Objectives To assess outcomes of radial head replacements in acute 3 and 4 radial head fractures by assessing elbow function, pain, elbow mobility post radial head arthroplasty and complications. Method A retrospective study design was used. Records were retrieved for all 40 patients who underwent a radial head replacement for a Mason III and IV fracture at Helen Joseph Hospital over a ten year period. Participants were traced and asked to complete a data sheet and undergo an examination by an interviewer. The data sheet included demographics, surgical and injury details, as well as details relating to function based on the Mayo Elbow Performance Score. Results Of a sample size n=16, 8 were male and 8 were female with an age range of 29 to 61 years and a mean age of 42.5 years. The length of follow up ranged from 2 to 8 years. When asked about daily functionality, 4 reported difficulty with one of the five tasks assessed on the Mayo Elbow Performance Score and 12 reported no difficulty with any of the tasks assessed. Moderate pain was reported by 8 with the other 8 patients reporting no pain.The flexion-extension arc ranged from 60º to 160º on examination with an average of 111º. An arc of greater than 100º was achieved in 11 out of 16 patients . A total of five patients had an arc of greater than 50º but less than 100. No patients had an arc less than 50º . Stability was assessed and scored. No study participants had any gross instability. Moderate instability was detected in 6 participants. Complications were noted in 2 of the 16 participants (One posterior interosseus nerve injury and one possible Essex-Lopresti injury). The final MEPS scores showed that 8 patients had good results and 8 patients had excellent functional outcomes with no fair or poor outcomes. Conclusions Good to excellent functional outcomes can be achieved with radial head replacement in Mason III and IV fractures with minimal complications however, longer term follow up with level one evidence is still needed. / MT2017

Proximal forearm fractures account for over 10% of all upper limb fractures. There is limited epidemiological data available and much of the literature focuses on the more complex fracture patterns, with the role of non-operative management for the isolated proximal forearm fracture still to be defined. Prospective short and long-term patient reported outcome data for simple isolated fractures of the radial head and olecranon would help define the indications for the non-operative management of these injuries. This thesis aims to test the hypothesis that non-operative management provides a comparable outcome to operative intervention for defined fractures of the proximal forearm. A large prospective database of 6872 fractures collected over a one-year period was used to define the epidemiology of proximal forearm fractures. A separate large prospective study carried out over an eighteen-month period using a pre-defined management protocol for all isolated radial head and neck fractures was analysed to determine the short and long-term outcome. Additional retrospective databases were collected and analysed to determine the short and long-term outcome for the non-operative and operative management of olecranon fractures, as well as the operative management of complex radial head fractures. Finally, two prospective randomised controlled trials (PRCTs) of isolated displaced fractures of the olecranon were carried out to compare 1) tension band wire (TBW) versus plate fixation in younger patients (< 75 years) and 2) operative versus non-operative management in elderly patients (≥75 years). The primary outcome measure for these studies was the upper limb specific patient reported Disabilities of the Arm, Shoulder and Hand (DASH) score. Secondary outcome measures included surgeon reported outcome scores, complication rates and cost. The incidence of proximal forearm fractures was 68 per 100,000. Radial head fractures fit a type D distribution curve (unimodal young man, bimodal woman) and radial neck type A (unimodal young man, unimodal older woman). Proximal ulna and olecranon fractures were both a type F (unimodal older man, unimodal older woman), with an increasing incidence after the 6th decade. Over 90% of proximal radial fractures were isolated stable fractures. Prospective analysis of 201 isolated proximal radius fractures found that the patient and surgeon reported outcome following primary non-operative management for Mason type 1 and type 2 (n=185) fractures was excellent in the short and long-term, with < 2% of patients undergoing secondary surgical intervention. At a mean of 10 years post injury (n=100), the mean DASH score was 5.8 and 92% of patients were satisfied. Factors associated with a poorer short and long-term patient reported outcome included increasing fracture displacement (≥5mm) and socio-economic deprivation. Retrospective analysis of 105 acute unstable complex radial head fractures found that the mean short-term functional outcome was good (mean Broberg and Morrey Score 80) following radial head replacement. In the long-term (mean 7 years), 28% of patients required removal or revision of the prosthesis, with younger patients and silastic implants independent risk factors (both p < 0.05). Retrospective analysis of 36 operatively managed isolated displaced olecranon fractures found satisfactory short and long-term outcomes, with the symptomatic metalwork removal rate 47% and the mean DASH 2.5 at a mean of seven years post injury. In the PRCT of plate (n=34) versus TBW (n=33) fixation, comparable functional and patient reported outcomes (DASH 8.5 vs 13.5; p=0.252) were found at one year following injury. Complication rates were significantly higher in the TBW group (63.3% vs 37.5%; p=0.042), predominantly due to a significantly higher rate of symptomatic metalwork removal (50.0% vs 21.9%; p=0.021), resulting in equivocal costs for both techniques (p=0.131). In older lower-demand patients, short and long-term retrospective analysis found very satisfactory outcomes following non-operative management of isolated displaced fractures of the olecranon, with patient satisfaction 91% and no patients requiring surgery for a symptomatic non-union. The preliminary results of the PRCT of non-operative (n=8) versus operative (n=11) management demonstrated comparable functional and patient reported outcomes at all points over the one-year following injury (all p≥0.05), with a higher rate of complications (81.8% vs 14.3%; p=0.013) and cost (p=0.01) following surgical intervention. The association found between fragility and the epidemiology of proximal forearm fractures highlighted the importance of considering non-operative management for these injuries. These findings support non-operative management for isolated stable radial head and neck fractures. For more complex injuries when radial head replacement is indicated, there is a high rate of removal or revision, with younger patients most at risk. In younger active patients with an isolated displaced fracture of the olecranon, TBW and plate fixation provide comparable short-term results, with TBW fixation as cost effective despite an increased rate of metalwork removal. In older lower demand patients, this data provides strong evidence for the non-operative management of isolated displaced olecranon fractures.

No description available.

<p>Radial head arthroplasty (RHAP) is proposed as the treatment of choice of complex radial head fractures not amenable to reconstruction. With advances in the understanding of elbow biomechanics and subsequently implant designs, low morbidity, few complications and good success has been reported with RHAP compared to internal fixation. Much of the success/complication post RHAP has been attributed to the fracture pattern and presence of associated injuries. While these are important parameters to reflect on, however, the outcome of surgery cannot be solely attributed to the methods of dealing with the radial head fracture. Importantly, the outcomes of RHAP are also influenced by patient factors. Hence, the purpose of this thesis was to assess the existing knowledge of functional outcomes post RHAP and explore the role of acute post surgical pain as a predictor of those outcomes.</p> <p>The first manuscript in the thesis systematically examines the current available English literature regarding the functional outcomes of metal RHAP. Studies reviewed revealed significant heterogeneity in the study and patient characteristics. Likewise, the method of reporting fracture classification, clinician and patient reported outcomes are inconsistent. Based on the level 4 evidence studies in the review, we concluded that RHAP provides good to excellent outcomes in short-midterm follow up, with no evidence regarding the superiority of one implant over another.</p> <p>The second manuscript explored the role of acute post surgical pain in development of chronic functional impairment post RHAP using the EVOLVE (Wright Medical Technology, Arlington, Tennessee) implant at 2 years post surgery. A total of 59 adults with complex radial head fractures treated with EVOLVE metal radial head implant were followed for a period of two years. Demographics, American Shoulder and Elbow Surgeon's-Elbow (ASES-e) pain subscale and Disability of Arm, Hand and Shoulder Questionnaire (DASH) data were collected at baseline and two years. Regression analyses revealed that acute post operative pain post RHAP is significantly related to the functional outcome at 2 years post RHAP. An ASES-e pain cut off score of 32/50 predicted the development of chronic functional impairment two years post RHAP.</p> <p>The results of this thesis highlight the need for prospective longitudinal studies, comparative analyses and standardized methods of reporting concerning effectiveness of RHAP. It also emphasizes the significance of quantifying pain levels in the immediate post operative period and classifying the patient in high/low risk groups for developing chronic functional impairment based on the pain level.</p> / Master of Science (MSc)

Le cubitus proximal détient une courbe sagittale unique pour chaque individu, nommée « Proximal Ulna Dorsal Angulation (PUDA) ». Une reconstruction non-anatomique du cubitus proximal, suite à une fracture complexe peut engendrer une malunion, de l’arthrose et de l’instabilité. L’objectif de cette étude était d’évaluer la magnitude de malalignement au niveau de l’angulation proximale dorsale du cubitus qui causerait un malalignement radio-capitellaire, avec et sans un ligament annulaire intact. Afin d’atteindre cet objectif, une étude biomécanique fut conduite sur six spécimens frais congelés avec un simulateur de mouvement du coude. Des fractures simulées au niveau du PUDA, furent stabilisées avec une fixation interne dans cinq configurations différentes. Des images fluoroscopiques furent prises dans différentes positions du coude et de l’avant-bras, avec le ligament annulaire intact, puis relâché. Le déplacement de la tête radiale fut quantifié avec le ratio radio-capitellaire. Une interaction significative fut découverte entre les positions du coude, les angles de malalignement et l’intégrité du ligament annulaire. La subluxation de la tête radiale fut accentuée lors de la déchirure du ligament annulaire. Une augmentation de la subluxation antérieure de la tête radiale fut observée lorsque le malalignement était fixé en extension et lors de mouvements de flexion progressive du coude. D’autre part, un malalignement en flexion et une extension graduelle du coude occasionnait une subluxation postérieure. En conclusion, les résultats ont démontré l’importance d’une reconstruction anatomique du cubitus proximal, car un malalignement de 5 degrés engendre une subluxation de la tête radiale, surtout lors d’une déchirure du ligament annulaire. / It has been shown that the proximal ulna has a sagittal bow, named the Proximal Ulna Dorsal Angulation (PUDA), unique for each individual. Non-anatomic reconstruction of the proximal ulna following a complex injury may lead to malunion, arthrosis and instability, hence the importance of understanding its initial anatomy. The purpose of this study was to evaluate the magnitude of angular malalignement at the proximal ulna dorsal angulation that would lead to radiocapitellar malalignement, with and without an intact annular ligament. In order to achieve our goal, a biomechanical study was conducted on six fresh frozen specimens, with an elbow movement simulator. Simulated fractures at the PUDA were stabilized with internal fixation at five different angles. Then, fluoroscopic images were taken in different elbow and forearm positions, first with the annular ligament intact and then released. Radial head displacement was quantified with the Radio-Capitellar-Ratio (RCR). Overall, a significant interaction was found between elbow positions, angles of malalignement and annular ligament integrity. Radial head subluxation was emphasized when the annular ligament was ruptured. Moreover, anterior subluxation of the radial head increased as malalignement was fixed into extension and with progressive elbow flexion. Furthermore, posterior subluxation increased with malalignement into flexion and with elbow extension. In conclusion, our results demonstrate the importance of obtaining an anatomic reconstruction, specific for each individual’s unique proximal ulna dorsal angulation, following a proximal ulna fracture. Indeed, malalignment of 5 degrees can lead to abnormal tracking of the radial head, especially when associated with annular ligament tear.

No description available.

Rigid body modeling has historically been used to study various features of the elbow joint including both physical and computational models. Computational modeling provides an inexpensive, easily customizable, and effective method by which to predict and investigate the response of a physiological system to in vivo stresses and applied perturbations. Utilizing computer topography scans of a cadaveric elbow, a virtual representation of the joint was created using the commercially available MIMICS(TM) and SolidWorks(TM) software packages. Accurate 3D articular surfaces, ligamentous constraints, and joint contact parameters dictated motion. The model was validated against two cadaveric studies performed by Chanlalit et al. (2011, 2012) considering monopolar and bipolar circular radial head replacements in their effects on radiocapitellar stability and respective reliance upon lateral soft tissues, as well as a comparison of these with a novel anatomic radial head replacement system in an elbow afflicted with the “terrible triad” injury. Rigid body simulations indicated that the computational model was able to accurately recreate the translation of forces in the joint and demonstrate results similar to those presented in the cadaveric data in both the intact elbow and in unstable injury states. Trends in the resulting data were reflective of the average behavior of the cadaveric specimens while percent changes between states correlated closely with the experimental data. Information on the transposition of forces within the joint and ligament tensions gleaned from the computational model provided further insight into the stability of the elbow with a compromised radial head.

The use of computational modeling is an effective and inexpensive way to predict the response of complex systems to various perturbations. However, not until the early 1990s had this technology been used to predict the behavior of physiological systems, specifically the human skeletal system. To that end, a computational model of the human elbow joint was developed using computed topography (CT) scans of cadaveric donor tissue, as well as the commercially available software package SolidWorks™. The kinematic function of the joint model was then defined through 3D reconstructions of the osteoarticular surfaces and various soft-tissue constraints. The model was validated against cadaveric experiments performed by Hull et al and Fern et al that measured the significance of coronoid process fractures, lateral ulnar collateral ligament ruptures, and radial head resection in elbow joint resistance to varus displacement of the forearm. Kinematic simulations showed that the computational model was able to mimic the physiological movements of the joint throughout various ranges of motion including flexion/extension and pronation/supination. Quantitatively, the model was able to accurately reproduce the trends, as well as the magnitudes, of varus resistance observed in the cadaveric specimens. Additionally, magnitudes of ligament tension and joint contact force predicted by the model were able to further elucidate the complex soft-tissue and osseous contributions to varus elbow stability.