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

1. A method of denervating the elbow joint, based upon observations on the articular branches of the main nerve trunks, is presented. 2. In a small group of cases with post-traumatic arthritis and osteoarthritis, relief of pain and restoration of painless movement has been gained. 3. There was recurrence of pain after six months in one patient with acute rheumatoid arthritis; in such cases denervation is not recommended until further study is completed. 4. Denervation must be as complete as possible and full exposure with stripping of nerve trunks is recommended. There have been no complications. 5. The results in this small series of cases are encouraging, but patients should be warned that there will be no significant increase in the range of movement, and that a normal joint is not to be expected. 6. Articular neurectomy is still on trial. If the limitations are recognised, the procedure may have a useful place in the relief of pain in the elbow joint

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

1. The age changes in the articular cartilage of the elbow joint are presented from a study of twenty-eight necropsy subjects aged eighteen to eighty-eight years. During early adult life those areas of cartilage which do not usually articulate with opposed cartilage always show some degree of chondromalacia. 2. Evidence is presented that the almost inevitable degeneration of the radio-humeral joint in old age is related to the combination of rotation and hinge movements that occur at that joint. This is in marked contrast with the relative immunity of the humero-ulnar articulation which has hinge movement only

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

Two boys with entrapment of the median nerve in the elbow joint after closed reduction of a posterior dislocation with fracture of the medial epicondyle showed a characteristic radiological sign in the anteroposterior radiograph after two to three months. The sign was a depression in the cortex on the ulnar side of the distal humeral metaphysis, with interruption of the local periosteal reaction. At operation in both patients the depression was found to correspond with the place where the median nerve reached the posterior surface of the humerus. Radiographs taken after transverse section of the nerve above and below the joint capsule and end-to-end suture showed gradual disappearance of the cortical depression

Aims

The purpose of this study was to evaluate the relationships between the degree of injury to the medial and lateral collateral ligaments (MCL and LCL) and associated fractures in patients with a posterolateral dislocation of the elbow, using CT and MRI.

We describe a posterior approach to the elbow which combines the advantages of both splitting and reflecting the triceps. It gives protection to the ulnar nerve and its blood supply during the operation while providing excellent exposure of the distal humerus. During closure, the triceps muscle can be tensioned, thereby improving stability of the elbow. This approach has particular relevance to unlinked total elbow arthroplasty allowing early rehabilitation of the joint.

Between 1969 and 1985 26 patients with destructive lesions of the distal humerus were treated by endoprosthetic replacement; each implant was custom-made and incorporated part of the distal humerus or the entire bone as well as a hinged total elbow replacement. Recurrence occurred in three of the patients with tumours, and three prostheses were removed because of deep infection in patients with previously compound injuries of the elbow. Another three loosened without infection, but none needed revision or removal and no amputations resulted. Other complications included nerve palsies, but the only deaths were from metastases. A useful range of elbow movement, with a stable arm and good hand function, was achieved in every patient.

1. In a survey of 107 cases of Erb's paralysis, twenty-seven instances of incipient or actual posterior dislocation of the upper end of the radius were discovered.

2. The type of case in which the dislocation occurs is defined and the early clinical and radiographic signs of the displacement are described and illustrated.

3. The probable causes—muscle imbalance and rigid splinting over a long period—are adumbrated and the prevention and remedies are suggested.

4. The occurrence of anterior dislocation—six cases—and its significance are discussed.

Aims

The aim of this retrospective multicentre study was to evaluate mid-term results of the operative treatment of Monteggia-like lesions and to determine the prognostic factors that influence the clinical and radiological outcome.

We assessed the short- to mid-term survival of metallic press-fit radial head prostheses in patients with radial head fractures and acute traumatic instability of the elbow.

The medical records of 42 patients (16 males, 26 females) with a mean age of 56 years (23 to 85) with acute unstable elbow injuries, including a fracture of the radial head requiring metallic replacement of the radial head, were reviewed retrospectively. Survival of the prosthesis was assessed from the radiographs of 37 patients after a mean follow-up of 50 months (12 to 107). The functional results of 31 patients were assessed using range-of-movement, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH) score and the RAND 36-item health survey.

At the most recent follow-up 25 prostheses were still well fixed, nine had been removed because of loosening, and three remained implanted but were loose. The mean time from implantation to loosening was 11 months (2 to 24). Radiolucent lines that developed around the prosthesis before removal were mild in three patients, moderate in one and severe in five. Range of movement parameters and mass grip strength were significantly lower in the affected elbow than in the unaffected side. The mean MEPS score was 86 (40 to 100) and the mean DASH score was 23 (0 to 81). According to RAND-36 scores, patients had more pain and lower physical function scores than normal population values.

Loosening of press-fit radial head prostheses is common, occurs early, often leads to severe osteolysis of the proximal radius, and commonly requires removal of the prosthesis.