We report an artificial elbow joint with a novel type radial component that we have designed that is now at the stage of trial production. The humeral component is a trochlea capitulum replacement type with a stem. The ulnar component with a stem has an articular surface distributed not only on the trochlea surface but also on the capitulum surface of the humeral component, and has another concave articular surface toward the radial component. The radial component also has a stem and has a spherical convex articular surface. This surface of the radial component does not assume the conventional anatomical morphology, but the convexity is designed to fit the concave articular surface of the ulnar component. In other words, the new artificial elbow joint is a functionally dissociated type, in which flexion-extension is achieved by the humeroulnar joint while rotation is done via the radioulnar joint. The newly designed artificial joint was used to replace the cadaveric elbow joint. Radiographic studies were conducted to observe the compatibility of each component during extension-flexion and rotationmovements. By replacing the cadaveric elbow joint with the newly designed artificial elbow joint and performing manual extension-flexion simultaneous with pronation-supination, the flexion positions of the humeral component and ulnar component were not affected, and stable compatibility was obtained for the radial component and ulnar component. Artificial elbow joints with a radial component have been reported by various authors. However, since the humeroradial joint possesses two movement axes for both flexion-extension and rotation, good compatibility with the humeroulnar joint is necessary. Aradial component that simply adopts the anatomical morphology does no tachieve good humeroradial joint compatibility. The functionally dissociated artificial elbow joint that we have designed is expected to offer a clue to solve these problems

The objective of this report was to evaluate myofibroblast numbers in human elbow anterior joint capsules. Joint capsules were obtained from six patients with post-traumatic contractures and from six elbow joints of age-matched organ donors. Frozen sections were labeled with α-smooth muscle actin (α-SMA), a marker of myofibroblasts. Myofibroblasts were identified in both experimental and control tissues. Myofibroblast numbers and percentage of total cells were significantly elevated in the capsules of patients (919 ± 187; 36 ± 0.04%) when compared to organ donor control tissue (485 ± 335; 9 ± 0.04%). Future work will look at the expression of myofibroblast modulators in human elbow joint contractures. The purpose of this study was to determine whether myofibroblasts are associated with human elbow joint contractures. Myofibroblast numbers and percentage of myofibroblasts to total cells were significantly increased in anterior elbow joint capsules of patients with post-traumatic contractures. Methods to alter myofibroblast expression may be strategies to prevent or treat post-traumatic elbow joint contractures. Joint capsules were obtained from six patients (age 33±13 yrs, preoperative flexion-extension arc range of motion 58°±15°) and from six elbow joints of organ donors free of contractures (age 26±15 yrs). Frozen sections were double labeled using monoclonal antibodies to α-smooth muscle actin (α-SMA) with peroxidase conjugated secondary antibodies, and affinity purified antibodies to laminin with Elexa Fluor 488 conjugated secondary antibodies. The laminin antibodies label components of blood vessels, to differentiate between α-SMA expression associated with blood vessels or myofibroblasts. Endogenous peroxidases were quenched and 10% normal goat serum was used as a blocking agent. DAB/peroxide substrate was added for thirteen minutes. DAPI was applied to label nuclei. Cell nuclei associated with α-SMA and not with laminin were counted as myofibroblasts. Myofibroblast numbers and percentage of total cells were significantly increased (t-test, p < 0.05) in the joint capsules of the patients when compared to organ donor control tissue. Total cell numbers were not significantly different in the patient and control tissue. Modulators of α-SMA expression and myofibroblast formation include growth factors and matrix molecule components. Future work will look at the expression of these modulators in human elbow joint contractures. Funding: Funding has not been received from a commercial party. This work was supported by The Alberta Heritage Foundation for Medical Research. Please contact author for tables and/or diagrams

Purpose of the study: There is no satisfactory surgical solution for symptomatic osteoarthritis of the elbow joint with preserved functional motion if arthroplasty is not indicated (age, functional demand). The same is true for resistant epicondylalgia. The joint denervation techniques applied for the wrist and proximal inter-phalangeal joints have demonstrated their efficacy. We conducted an anatomic study of elbow innervation as a preliminary step to the development of a standardized surgical procedure for complete denervation of the elbow compartment. Material and methods: The study was conducted on 15 right and left unprepared fresh cadaver specimens. A standardized dissection method was used. The terminal branches of the brachial plexus were dissected proximally to distally under magnification, from the root of the arm to the mid third of the forearm. Results: Innervation of the medial compartment arose: anteriorly, from one of the two capsuloperiosteal branches arising from the medial nerve; in the epitrochleo-olecraneal gutter, from capsular branches issuing from the trunk of the radial nerve at the root of the arm and running with the ulnar nerve. The innervation of the lateral compartment arose: anteriorly, from an inconstant capsular branch issuing from the musculo-cutaneous nerve arising 4 to 7 cm downstream from the joint space and running between the bones. In the other cases, this zone was innervated by a nerve branch coming from the dorsal cutaneous nerve of the forearm issuing from the radial nerve. This branch innervated the apex of the laeral epicondyle in all cases. The posterior part of the lateral compartment was constantly innervated by a branch arising from the radial nerve in the proximal part of the arm, running between the deep hed of the triceps and the vastus lateralis, giving rise of nerves innervating the joint and terminating in the body of the anconeus muscle. Discussion: Our study enabled the description of new sources of elbow innervation not reported by Wilhelm. Conclusion: This systematization study of elbow joint innervation is a preliminary step to the development of a complete procedure for unicompartmental lateral or medial denervation of the elbow joint. The fields of application are the treatment of symptomatic osteoarthritis of the elbow joint in patients with preserved joint motion and resistant epicondylalgia

The hypothesis is that mast cell numbers and neuropeptide containing nerve fibres are increased in the elbow joint anterior capsule of patients with post-traumatic contractures when compared to normal capsules. Capsules were obtained from two patients with chronic contractures following radial head fractures and two organ donor elbows free of contractures. Four sections from each capsule were double-labelled with specific antibodies to the mast cell marker chymase and the neuropeptide calcitonin gene-related peptide (CGRP). Species specific secondary fluorescent antibodies were used to detect the marker antibodies and cells were identified with a fluorescent nuclear marker (DAPI). Images were captured using a microscope (200x magnification) and five randomly selected areas were sampled for each section obtained from all joint capsules. Chymase positive cell numbers and numbers of nerve fibers (minimum length fifty micrometres) were gathered. The number of chymase positive mast cells was 6x greater in the contracture capsules when compared to normal capsules. In the contracture capsule, chymase positive mast cells represented 39% of total cells while in control capsules they represented 7% of total cells. Total cell numbers were similar in the capsules of both groups. The number of CGRP positive nerve fibres was increased 3x in the contracture capsule when compared to normal capsule. Mast cell numbers and neuropeptide positive fibre numbers are increased in the elbow joint anterior capsule of patients with post-traumatic contractures when compared to normal tissues. Neuropeptides such as CGRP can induce mast cell degranulation. Mast cells release profibrotic molecules such as transforming growth factor beta1 (TGF-b1), a myofibroblast upregulator. It has been described that TGF-b1 and myofibroblast numbers are elevated in human elbow joint capsules in post-traumatic contractures. While these trends are encouraging, more subjects are needed to determine whether the mast cell and neuropeptide nerve fibre findings can be generalised to larger numbers. If future work supports a myofibroblast - mast cell - neuropeptide - fibrosis axis in the joint capsule in post-traumatic contractures, then methods to modulate this axis, such as mast cell stabilisers, may be evaluated in animal models

Introduction The radial nerve is at risk in arthroscopic elbow surgery and there are reports of significant nerve injury, particularly with arthroscopic synovectomy or arthroscopic capsulectomy for the stiff elbow. This study was aimed to further define the relationship of the radial nerve to the elbow joint. Methods Magnetic Resonance Imaging studies of 23 elbows with minimal or no pathology were used to measure the distance of the radial nerve from the border of the radial head and the position of the nerve relative to the bony landmarks of the elbow joint. Results The radial nerve or its branches were found to lie on average 6.6 mm from the border of the radial head (range 3 to 9 mm) and in an arc of 64° antero-lateral to the radial head. At the level of the radial head the nerve was not separated from capsule by muscle in 12 of the 23 elbows. Conclusions Care should be taken in the insertion of antero-lateral portals in elbow arthroscopy as the position of the radial nerve and its branches is variable. Arthroscopic synovectomy and capsulectomy should be carried out above the level of the radial head where the nerve is protected by brachialis to avoid permanent damage to the radial nerve

Aims: The aim of the study was to investigate the anatomy of the medial collateral ligament of the Articulatio cubiti and to analyse its clinical importance. Methods: Eight alcohol-formalin-glycerol þxed elbow joints were dissected (age range 65 Ð 78). The muscles of the arm, elbow and the forearm were removed. The ligaments of the elbow joint were þnely dissected. The joint cavity was opened and the intra-articular anatomy of the medial collateral ligament was described. Results: In all the investigated specimens the Lig. collaterale ulnare was composed of three parts Ð Partes anterior, posterior et obliquus. The oblique (transverse) part of the ligament spread between Processus coronoideus and Olecranon. Intra-articularly the Pars obliqua strengthened the joint capsule at the lower part of the ulnohumeral connection in all the dissected specimens. Conclusions: It is the common belief, that the oblique part of the Lig. collaterale ulnare is unstable anatomical variation, that does not cross the ulnohumeral joint. According to our þndings it is a constant anatomical structure that is intra-articularly visible within the lower part of the medial joint capsule. It does not connect only the bony parts of the Processus coronoideus and Olecranon, but also strengthens the articular joint capsule and contributes to elbow stability. This anatomical fact should be taken into consideration during the diagnosis and treatment of different elbow joint pathologies

Purpose: Elbow osteoarthritis (OA) is characterized by a loss of elbow motion secondary to joint capsular hypertrophy and osteophyte formation. Previous work on joint capsules in post-traumatic (PT) elbow joint contractures has shown that alterations in cell populations (increased number of alpha-SMA positive myofibroblasts), matrix molecule and enzyme, and growth factor mRNA profiles are associated with loss of elbow motion in this condition. The objective of this study was to determine whether alterations in joint capsule parameters were similar or different in two etiologies of human elbow contractures, primary OA and PT. Method: Posterior elbow joint capsules were obtained from eight male patients with primary elbow OA (age 52±12 yr ), five male patients with chronic (> 1 year) PT (age 47±12 yr ) and four male organ donors free of OA and contractures (age 43±10 yr ). RNA was extracted for subsequent real-time PCR for alpha-SMA, interleu-kin-1beta, MMP-1, MMP-3, collagen type III, biglycan, versican, tenascin C, TIMP-1, MMP-2, iNOS, COX-2, glyceraldehyde – 3 phosphate dehydrogenase (GAPDH) and 18S. 18S was used to normalize gene expression. Statistical comparisons used a oneway ANOVA followed by posthoc Tukey test. Significance was p < 0.05. Results: The mRNA levels in the OA and PT capsules were increased compared to controls in most cases. This includes the major matrix molecule collagen I and the myofibroblast marker alpha-SMA, the growth factors TGF-beta1 and CTGF plus decorin, the injury response elements (collagen III, biglycan, versican, tenascin C) as well as TIMP-1 and MMP-2. The housekeeping gene GAPDH was similar in all 3 groups as was COX-2, while iNOS was elevated in both groups characterized by contractures. When comparing the two contracture groups, the mRNA levels were similar for some molecules while differences were evident in other instances. In PT, alpha-SMA and collagen I were greater than in OA. Conversely, in the OA group, the growth factors and matrix enzyme systems exhibited higher levels than PT. Conclusion: In this study of human elbow joint capsules, we have shown that relative mRNA levels for markers of myofibroblasts, major matrix components, injury response elements and selected growth factors are significantly elevated in elbow OA and post-traumatic contractures when compared to age matched organ donor controls free of contractures. When comparing the OA and PT groups, the injury response molecules were elevated to similar relative levels. The OA group had greater increases in the growth factors and many of the matrix enzymes / inhibitors measured, while the PT group had greater increases in the myofibroblast marker alpha-SMA and the major matrix molecule collagen I. Thus in general matrix, growth factor and cellular properties appear to be preferentially altered in the two conditions studied when compared to control tissues, strengthened by the fact that the housekeeping gene GAPDH had similar relative levels in all 3 groups

Purpose: To develop a computerized inverse dynamic 3D model of the upper limb, focussing on the elbow. Methods: Anatomic bony landmarks were identified in one cadaveric arm using an electromagnetic tracking device (Flock of Birds, Ascension Technologies, VT). The articular surfaces of the radiohumeral and ulnohumeral joints were digitized, thereby identifying the areas over which the contact forces could act. Attachment sites of the medial collateral (MCL) and lateral collateral (LCL) ligaments and the major muscles (BRA=brachialis, BIC=biceps, BRD=brachioradialis, TRI=triceps) were also digitized to create line-of-action vectors. These data were fed into custom-written software (MATLAB®, The MathWorks Inc., MA) that simulated flexion with gravity as external loading, and calculated the forces exerted by the joint structures. As an indeterminate system, computerized mathematical optimization solved for the internal loads using a cost function that minimized the sum of forces squared. Results: Model outputs were comparable with results from previous muscle activity and cadaveric studies. Force ratios among the elbow’s prime movers at 30 degrees of flexion agreed quite closely with previous findings (Funk et al, 1987), with percent differences of 11% (BRA), −5% (BIC), −6% (BRD), and −1% (TRI). Overall, the brachialis force was the highest throughout flexion, being the prime mover, while extensor (triceps) activity remained quiet through mid-range. The magnitude of the radiohumeral contact force showed a decreasing pattern through the arc of flexion, similar to the trend found experimentally by others (Morrey et al, 1988). The results also demonstrated stabilizing forces supplied by the MCL, but not the LCL. Conclusions: Current understanding of upper extremity loading is very limited. Creating an accurate computerized model of the elbow joint, would reduce the need for experimental testing with cadavers, which are always of limited availability. While stability of the elbow has been experimentally investigated, this model will be able to quantify the forces within the stabilizing structures. By establishing a normal baseline of these forces, surgical procedures and joint replacement designs can be validated. Thus, this model can provide a significant contribution to upper extremity biomechanics research and clinical treatments

Aims. The ulna is an extremely rare location for primary bone tumours of the elbow in paediatrics. Although several reconstruction options are available, the optimal reconstruction method is still unknown due to the rarity of proximal ulna tumours. In this study, we report the outcomes of osteoarticular ulna allograft for the reconstruction of proximal ulna tumours. Methods. Medical profiles of 13 patients, who between March 2004 and November 2021 underwent osteoarticular ulna allograft reconstruction after the resection of the proximal ulna tumour, were retrospectively reviewed. The outcomes were measured clinically by the assessment of elbow range of motion (ROM), stability, and function, and radiologically by the assessment of allograft-host junction union, recurrence, and joint degeneration. The elbow function was assessed objectively by the Musculoskeletal Tumor Society (MSTS) score and subjectively by the Toronto Extremity Salvage Score (TESS) and Mayo Elbow Performance Score (MEPS) questionnaire. Results. The mean follow-up of patients was 60.3 months (SD 28.5). The mean elbow flexion-extension ROM was 95.8° (SD 21). The mean MSTS of the patients was 84.4 (SD 8.2), the mean TESS was 83.8 (SD 6.7), and the mean MEPS was 79.2 (SD 11.5). All the patients had radiological union at the osteotomy site. Symptomatic osteoarthritic change was observed in three patients (23%), one of whom ended up with elbow joint fusion. Two patients (15.4%) had recurrence during the follow-up period. Surgical complications included two allograft fractures, two plate fractures, three medial instabilities, and two infections. Conclusion. Osteoarticular ulna allograft reconstruction provides acceptable functional outcomes. Despite a high rate of complications, it is still a valuable reconstruction method, particularly in skeletally immature patients who need their distal humerus physis for the rest of hand growth. Cite this article: Bone Jt Open 2024;5(9):749–757

To analyse bone stresses in humerus-megaprosthesis construct in response to axial loading under varying implant lengths in proximal humeral replacement following tumour excision. CT scans of 10 cadaveric humeri were processed in 3D Slicer to obtain three-dimensional (3D) models of the cortical and cancellous bone. Megaprostheses of varying body lengths (L) were modelled in FreeCAD to obtain the 3D geometry. Four FE models: group A consisting of intact bone; groups B (L=40mm), C (L=100mm) and D (L=120mm) comprising of humerus-megaprosthesis constructs were created. Isotropic linear elastic behaviour was assigned for all materials. A tensile load of 200N was applied to the elbow joint surface with the glenohumeral joint fixed with fully bonded contact interfaces. Static analysis was performed in Abaqus. The bone was divided at every 5% bone length beginning distally. Statistical analysis was performed on maximum von Mises stresses in cortical and cancellous bone across each slice using one-way ANOVA (0-45% bone length) and paired t-tests (45-70% bone length). To quantify extent of stress shielding, average percentage change in stress from intact bone was also computed. Maximum stress was seen to occur distally and anteriorly above the coronoid fossa. Results indicated statistically significant differences between intact state and shorter megaprostheses relative to longer megaprostheses and proximally between intact and implanted bones. Varying levels of stress shielding were recorded across multiple slices for all megaprosthesis lengths. The degree of stress shielding increased with implant lengthening being 2-4 times in C and D compared to B. Axial loading of the humerus can occur with direct loading on outstretched upper limbs or indirectly through the elbow. Resultant stress shielding effect predicted in longer megaprosthesis models may become clinically relevant in repetitive axial loading during activities of daily living. It is recommended to use shorter megaprosthesis to prevent failure

Aim. Arthroscopic interventions have revolutionized the treatment of joint pathologies. The appropriate diagnostics and treatment are required for infections after ligament reconstructions using non-resorbable material such as tendon grafts, anchors, and sutures, prone to biofilm formation. The infection rate is around 1% for knee and shoulder, while up to 4% for Achilles tendon reconstructions. Despite high number of these procedures worldwide, there is limited evidence about the best treatment protocol. Our study aimed to provide a general protocol for the treatment of small implants for soft tissue reconstruction. Method. Between 2019 and 2023, we treated 48 infections of ligament, meniscus, and tendon reconstructions out of 7291 related procedures performed in the same time period. Early infection (<30 days) were treated with an arthroscopic debridement and implant retention (DAIR), except Achilles tendons had open DAIR, while those with delayed or chronic infection (>30 days) were treated with extensive debridement and lavage combined with one-stage exchange (OSE) or implant removal. During surgery, at least 5 microbiological s and samples for histopathology were obtained. The removed material was sonicated. After surgery, all patients were one week on iv. antibiotics, followed by oral antibiofilm antibiotics for 6 weeks including rifampicin and/or a quinolone. All patients were followed for at least 1 year. Failure was defined as the need for additional revision surgery after finished iv. antibiotic treatment. Results. Among 48 patients, 38 were early and 10 were late acute or chronic infections. The incidence of infection for our cohort was 0.7%. We observed 27 infections after ligament reconstruction of the knee, 15 of the shoulder, 5 of the ankle, and 1 infection of the elbow joint. 40 patients were treated with DAIR, 5 with OSE, and 3 with implant removal. We had 11 C. acnes, 10 S. aureus, 6 S. epidermidis, 2 P. aeruginosa, 2 S. lugdunensis, 10 mixed flora, and 3 culture-negative infections. 12 patients received antibiotics before surgery, and all culture-negative infections were related to this subgroup. We observed 2 failures, both in a combination of proximal tibial osteotomy and ligament reconstruction of the knee joint. The success rate of our protocol was 96%. Conclusions. Prompt surgical treatment followed by 6 weeks of antibiotic treatment cured 96% of infections of small implants after reconstruction procedures of knee, shoulder, and ankle joints. Our study is the first to provide a treatment protocol for infections of small implants after ligament reconstruction procedures

The objective of this study was to evaluate the functional outcome of the elbow joint in patients with heterotopic ossification of the elbow joint who underwent surgical excision of pathologic bone. From 5/1994 to 12/2006, 24 patients (33 joints) with heterotopic ossification of the elbow joint were evaluated. All patients were attended in the Intensive Care Unit (ICU). The patient\’s age ranged from 19–48 years (mean; 32 years) The median ICU hospitalization was 3 weeks. In nine patients both elbows were affected. Unilateral involvement was equally noticed to the right (seven cases) and the left elbow (eight cases). The DASH SCORE and the range of motion were used for the evaluation of the results. All patients underwent surgical treatment in order to extract heterotopic bone and to improve the range of motion of the affected elbow joint. Postoperatively 18 out of 33 operated elbow joints (54.54%) demonstrated improvement of the range of motion, whereas no improvement was observed in the remaining 15 elbow joints (45.45%). Higher DASH SCORE was obtained in 19 out of 24 patients (79.17%). Surgical excision of the ectopic bone around the affected elbow significantly improves the range of motion of the joint providing better use of the upper extremity and therefore a superior quality of life in these patients

In the treatment of acute elbow dislocation promising clinical results have been reported on articulated external fixation and surgical reconstruction of major joint stabilizers. However, it remains unclear whether or not surgical reconstruction of the major joint stabilizers sufficiently stabilizes the elbow joint or if augmentation by a hinged elbow fixator is beneficial to provide early stability and motion capacity. The aim of the present study was to compare the stabilizing potential of surgical reconstruction versus augmentation by a hinged external elbow in a model of sequentially induced intability of the elbow. Materials and Methods: 8 unpreserved human upper extremities were mounted to a testing apparatus which was integrated within a material testing machine. In a first series, varus and valgus moments were induced to the intact elbow joint at full extension, as well as at 30°, 60°, 90° and 120° of flexion and the mean angular displacement at 2.5, 5, an 7.5 Nm was calculated. Instability was then induced by sequentially dissecting the lateral and the medial collateral ligament, the radial head, and the posterior capsule. The elbow joint was then sequentially restabilized by osteosynthesis of the radial head and refixation of the lateral and medial collateral ligament using bone anchors. In each sequence, elbow stability was tested with and without augmentation by a hinged external fixator according to the first testing series described above. Biomechanical data of surgical reconstruction alone and surgical reconstruction augmented by external fixation were compared using an analysis of variance. Results: In the intact elbow, varus-valgus displacement with 7.5 Nm ranged from 8,3 ± 2,4° (0°) to 11,4 ± 4,2° (90°). With the fixator applied, varus-valgus displacement was significantly lower and ranged from 4,2 ± 1,3° (0°) to 5,3 ± 2,2° (90°). After complete destabilization of the elbow joint, maximum varus-valgus displacement ranged from 17,4 ± 5,3° (0°) to 23,6 ± 6,4° (90°). Subsequent reconstruction of the collateral ligaments, the posterior capsule, and the radial head proved to stabilize the elbow joint compared with the unstable situation, however, mean varus-valgus displacement remained significantly higher when compared to the intact elbow joint. During each sequence of instability, the hinged external fixator provided constant stability not significantly different to the intact elbow joint while guiding the elbow through the entire range of motion. Conclusion: The stabilizing potential of surgical reconstruction alone is inferior to augmentation of a hinged external elbow fixator. In order to proved primary stability and early motion capacity, augmentation of a hinged external elbow fixator in the treatment of acute dislocation of the elbow is recommended

Introduction and Objective. Curative resection of proximal humerus tumours is now possible in this era of limb salvage with endoprosthetic replacement considered as the preferred reconstructive option. However, it has also been linked with mechanical and non-mechanical failures such as stem fracture and aseptic loosening. One of the challenges is to ensure that implants will endure the mechanical strain under physiological loading conditions, especially crucial in long surviving patients. The objective is to investigate the effect of varying prosthesis length on the bone and implant stresses in a reconstructed humerus-prosthesis assembly after tumour resection using finite element (FE) modelling. Methods. Computed tomography (CT) scans of 10 humeri were processed in Mimics 17 to create three-dimensional (3D) cortical and cancellous solid bone models. Endoprostheses of different lengths manufactured by Stryker were modelled using Solidworks 2020. The FE models were divided into four groups namely group A consisting of the intact humerus and groups B, C and D composed of humerus-prosthesis assemblies with a body length of 40, 100 and 120 mm respectively and were meshed using linear 4-noded tetrahedral elements in 3matic 13. The models were then imported into Abaqus CAE 6.14. Isotropic linear elastic behaviour with an elastic modulus of 13400, 2000 and 208 000 MPa were assigned to the cortical bone, cancellous bone and prosthesis respectively and a Poisson's ratio of 0.3 was assumed for each material. To represent the lifting of heavy objects and twisting motion, a tensile load of 200 N for axial loading and a 5 Nm torsional load for torsional loading was applied separately to the elbow joint surface with the glenohumeral joint fixed and with all contact interfaces defined as fully bonded. A comparative analysis against literature was performed to validate the intact model. Statistical analysis of the peak von Mises stress values collected from predicted stress contour plots was performed using a one-way repeated measure of analysis of variance (with a Bonferroni post hoc test) using SPSS Statistics 26. The average change in stress of the resected models from the intact state were then determined. Results. The validation of the intact humerus displayed a good agreement with literature values. The peak bone stress occurred distally above the coronoid and olecranon fossa closer to the load application region in the intact and resected bone models with a significant amount of loading borne by the cortical bone, while the peak implant stress occurred at the bone-prosthesis contact interface under both loading conditions. Based on the results obtained, a statistically significant difference (p =.013) in implant stress was only seen to occur between groups B and C under tension. Results illustrate initiation of stress shielding with the bone bearing lesser stress with increasing resection length which may eventually lead to implant failure by causing bone resorption according to Wolff's law. The peak implant stress under torsion was 3–5 times the stress under tension. The best biomechanical behaviour was exhibited in Group D, having the least average change in stress from the intact model, 5% and 3.8% under tension and torsion respectively. It can be deduced that the shorter the prosthesis length, the more pronounced the effect on cortical bone remodelling. With the maximum bone and implant stresses obtained being less than their yield strength, it can be concluded that the bone-implant construct is safe from failure. Conclusions. The developed FE models verified the influence of varying the prosthesis length on the bone and implant stresses and predicted signs of stress shielding in longer endoprostheses. By allowing for 2 cm shortening in the upper extremity and post-surgical scarring, it is beneficial to err towards a shorter endoprosthesis

Introduction. Recently, computer-aided orthopaedic surgery has enabled three dimensional (3D) preoperative planning, navigation systems and patient matched instrument, and they provide good clinical results in total knee arthroplasty. However, the preoperative planning methods and the criteria in total elbow arthroplasty (TEA) still have not sufficiently established due to the uncertainty of 3D anatomical geometry of the elbow joints. In order to clarify the 3D anatomical geometry, this study measured 3D bone models of the normal elbow joints. Additionally this study attempted to apply the 3D preoperative planning to ordinary surgery. Then the postoperative position of implant has evaluated as compared with the position in 3D preoperative planning. Methods. Three dimensional bone measurements on 4 normal cases were performed. Three dimensional bone models were constructed with CT image using Bone Viewer®(ORTHREE Co., Ltd.). TEA was performed with FINE® Total Elbow System (Nakashima Medical Co., Ltd.) for 3 rheumatoid arthritis (RA) cases (Fig. 1). Three dimensional preoperative planning was based on this bone measurement, and postoperative position of implant were evaluated. The postoperative assessments were evaluated by superimposing preoperative planning image on postoperative CT image using Bone Simulator® (ORTHREE Co., Ltd.). This study only covers humeral part. Results. The results of 3D bone measurements on 4 normal cases shows the average internal rotation angle between the flexion-extension axis and the epicondyles axis in the distal humerus was 2.2 degrees. The average valgus tilt of the distal humerus was 3.7 degrees. Postoperative position of humeral component for 3 RA cases was installed at proximal and valgus position compared to the preoperative planning. Discussion. This study indicates that ordinary two dimensional criteria and 3D anatomical one in the elbow joint may be different in several bony landmarks such as rotation, varus and valgus. Additionally these results show the differences between postoperative position of implant and preoperative position in 3D planning. More studies need to be conducted to validate postoperative evaluation and preoperative planning

We investigated whether an alternative tension band wire technique will produce greater compression and less displacement at olecranon (elbow) fracture sites compared to a standard figure of eight tension band technique. Olecranon fractures are commonly treated with tension band wiring using stainless steel wire in a figure of eight configuration. However recently published studies have raised doubts over the validity of the tension band concept proving that the standard figure of eight configuration does not provide fracture compression when the elbow is flexed. We propose an alternative tension band technique where the figure of eight is applied in a modified configuration producing greater compression across the fracture. An artificial elbow joint was simulated using artificial forearm (ulna) and arm (humerus) bones. The design simulated the action of the muscles around the elbow joint to produce flexion and extension. There were two arms to this investigation. (1) Standard tension band wire configuration with stainless steel. (2) Modified tension band wire configuration with stainless steel. The simulated elbow was put through a range of movement and sensors measured the compression at the articular and non-articluar surfaces of the fracture. Measurements were taken for compression with different weights applied to challenge both the techniques of tension band wiring. Measurements from the non articular surface of the fracture demonstrated greater compression with alternative tension band technique. However it was not statistically significant (ANOVA). Compression at the articular surface of the fracture exhibited statistically significant (p<0.05) greater compression with the alternative technique. Neither technique produced greater compression during flexion of the simulated elbow. The alternative tension band wiring technique proved superior in providing greater compression over the fracture site

Insufficiency of the lateral collateral ligamentous complex causes posterolateral rotatory instability (PLRI). During reconstruction surgery the joint capsule is repaired, but its biomechanical influence on elbow stability has not been described. We hypothesized that capsular repair reduces ROM and varus angle after reconstruction of the lateral collateral complex. Six fresh frozen cadaveric elbow specimens were used. Varus laxity in supination, pronation and neutral forearm rotation with 1 Nm load and forearm rotaitonal range of motion (ROM) with 0.3 Nm torque were measured using a Microscribe 3DLX digitizing system (Revware Inc, Raleigh, NC). Each specimen was tested under four different conditions: Intact, Complete Tear with LUCL, RCL and capsule tear, LUCL/RCL reconstruction + capsule repair and LUCL/RCL reconstruction only. Reconstruction was performed according to the docking technique (Jones, JSES, 2013) and the capsule was repaired with mattress sutures. Each condition was tested in 30°, 60° and 90° elbow flexion. A two-way ANOVA with Tukey's post-hoc test was used to detect statistical differences between the conditions. Total ROM of the forearm significantly increased in all flexion angles from intact to Complete tear (p<0.001). ROM was restored to normal in 30° and 60° elbow flexion in both reconstruction conditions (p>0.05). LUCL/RCL Reconstruction + capsule repair in 90° elbow flexion was associated with a significantly lower ROM compared to intact (p=0.0003) and reconstruction without capsule repair (p=0.015). Varus angle increased significantly from intact to complete tear (p<0.0001) and restored to normal in both reconstruction conditions (p>0.05) in 30° and 60° elbow flexion. In contrast varus angle was significantly lower in 90° elbow flexion in both reconstruction conditions compared to intact (both p<0.0001). Reconstruction of the lateral collateral complex restores elbow stability, ROM and varus laxity independent of capsular repair. Over tightening of the elbow joint occurred in 90° elbow flexion, which was aggravated by capsular repair. Over all capsular repair can be performed without negatively affecting elbow joint mobility

Aims

There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

Aims

To propose a new method for evaluating paediatric radial neck fractures and improve the accuracy of fracture angulation measurement, particularly in younger children, and thereby facilitate planning treatment in this population.

Aims

The management of fractures of the medial epicondyle is one of the greatest controversies in paediatric fracture care, with uncertainty concerning the need for surgery. The British Society of Children’s Orthopaedic Surgery prioritized this as their most important research question in paediatric trauma. This is the protocol for a randomized controlled, multicentre, prospective superiority trial of operative fixation versus nonoperative treatment for displaced medial epicondyle fractures: the Surgery or Cast of the EpicoNdyle in Children’s Elbows (SCIENCE) trial.