The purpose of this study was to assess the long-term results (more than ten years) of two types of cemented ulnar component with type-5 Kudo total elbow arthroplasty in a consecutive series of 56 patients (60 elbows) with rheumatoid arthritis, and to compare the results in elbows above and below a Larsen grade IV. There was no radiolucency around the humeral component. Patients in whom a metal-backed ulnar component and a porous-coated stem were used had better clinical results and significantly less progression of radiolucent line formation around the ulnar component. They also had a significantly better long-term survival than patients with an all-polyethylene ulnar component. The clinical results of arthroplasty using all-polyethylene ulnar components were inferior, regardless of the degree of joint destruction. We conclude that the type-5 Kudo total elbow arthroplasty with cementless fixation of the porous-coated humeral component and cemented fixation of a metal-backed ulnar component is acceptable and well-tolerated by rheumatoid patients

Aims

The aims of this study were to identify and evaluate the current literature examining the prognostic factors which are associated with failure of total elbow arthroplasty (TEA).

Total elbow arthroplasty (TEA) usage is increasing owing to expanded surgical indications, better implant designs, and improved long-term survival. Correct humeral implant positioning has been shown to diminish stem loading in vitro, and radiographic loosening in in the long-term. Replication of the native elbow centre of rotation is thought to restore normal muscle moment arms and has been suggested to improve elbow strength and function. While much of the focus has been on humeral component positioning, little is known about the effect of positioning of the ulnar stem on post-operative range of motion and clinical outcomes. The purpose of this study is to determine the effect of the sagittal alignment and positioning of the humeral and ulnar components on the functional outcomes after TEA. Between 2003 and 2016, 173 semi-constrained TEAs (Wright-Tornier Latitude/Latitude EV, Memphis, TN, USA) were performed at our institution, and our preliminary analysis includes 46 elbows in 41 patients (39 female, 7 male). Patients were excluded if they had severe elbow deformity precluding reliable measurement, experienced a major complication related to an ipsilateral upper limb procedure, or underwent revision TEA. For each elbow, saggital alignment was compared pre- and post-operatively. A best fit circle of the trochlea and capitellum was drawn, with its centre representing the rotation axis. Ninety degree tangent lines from the intramedullary axes of the ulna and humerus, and from the olecranon tip to the centre of rotation were drawn and measured relative to the rotation axis, representing the ulna posterior offset, humerus offset, and ulna proximal offset, respectively. In addition, we measured the ulna stem angle (angle subtended by the implant and the intramedullary axis of the ulna), as well as radial neck offset (the length of a 90o tangent line from the intramedullary axis of the radial neck and the centre of rotation) in patients with retained or replaced radial heads. Our primary outcome measure was the quickDASH score recorded at the latest follow-up for each patient. Our secondary outcome measures were postoperative flexion, extension, pronation and supination measured at the same timepoints. Each variable was tested for linear correlation with the primary and secondary outcome measures using the Pearson two-tailed test. At an average follow-up of 6.8 years (range 2–14 years), there was a strong positive correlation between anterior radial neck offset and the quickDASH (r=0.60, p=0.001). There was also a weak negative correlation between the posterior offset of the ulnar component and the qDASH (r=0.39, p=0.031), and a moderate positive correlation between the change in humeral offset and elbow supination (r=0.41, p=0.044). The ulna proximal offset and ulna stem angle were not correlated with either the primary, or secondary outcome measures. When performing primary TEA with radial head retention, or replacement, care should be taken to ensure that the ulnar component is correctly positioned such that intramedullary axis of the radial neck lines up with the centre of elbow rotation, as this strongly correlates with better function and less pain after surgery

Between 1982 and 1997, 403 consecutive patients (522 elbows) with rheumatoid arthritis underwent Souter-Strathclyde total elbow replacement. By the end of 2007, there had been 66 revisions for aseptic loosening in 60 patients. The mean time of follow-up was 10.6 years (0 to 25) The survival rates at five-, ten, 15 and 19 years were 96% (95%, confidence interval (CI) 95 to 98), 89% (95% CI 86 to 92), 83% (95% CI 78 to 87), and 77% (95% CI 69 to 85), respectively. The small and medium-sized short-stemmed primary humeral components had a 5.6-fold and 3.6-fold risk of revision for aseptic loosening respectively, compared to the medium-sized long-stemmed component. The small and medium-sized all-polyethylene ulnar components had respectively a 28.2-fold and 8.4-fold risk of revision for aseptic loosening, compared to the metal-backed ulnar components. The use of retentive ulnar components was not associated with an increased risk of aseptic loosening compared to non-retentive implants

The aim of this study was to assess the long-term results of the Kudo type-5 total elbow prosthesis and compare the results of two types of cemented ulnar components. The Kudo type-5 unlinked total elbow prosthesis (Biomet UK Ltd, Bridgend Wales) was developed in 1993. The stem of humeral component is porous-coated with a plasma spray of titanium alloy for cementless use. The ulnar component may be metal-backed with a porous-coated stem or polyethylene alone; the latter designed mainly for cement use. A metal-backed type without a porous-coated stem designed for cement use also came into being after 2003. Between 1993 and 2010, the Kudo type-5 total elbow arthroplasty was performed on 364 elbows in 274 consecutive patients with rheumatoid arthritis. The mean age of the patients at the time of the operation was 60.7 (27–86) years. Twenty elbows had Larsen grade III, 224 had grade IV, and 120 had grade V changes pre-operatively. Before the operation, 346 elbows had severe or moderate pain, 95 had gross valgus-varus instability. Clinical symptoms and revision rates were assessed 4 to 20 years (mean, 9 years) postoperatively. The mean Mayo elbow performance scores were all poor except for three initially (mean overall score, 39.5 points). The overall score had improved substantially both at the early follow-up (1 to 3 years after the operation) and the latest follow-up (4 to 20 years after the operation), with 89.5 and 84.7 points, respectively. At the latest follow-up the overall result was excellent for 185 elbows, good for 103, fair for 11 and poor for 30, with almost complete relief from pain for 298. The arc of movement had increased from a mean of 85.7 °pre-operatively to 95.1 ° post-operatively, and to 98.1 °at the latest follow-up. Spot welds around the humeral stem suggesting solid osseous integration were often seen in the elbows with cementless fixation of the porous humeral stem. At the latest follow-up, implants were removed due to infection in 3 elbows. Twenty-five elbows required ulnar component revision due to loosening of the all-polyethylene component. Two elbows required ulnar component revision due to loosening of the metal-backed component. Seven elbows required humeral component revision due to loosening of the humeral components. One elbow required revision due to dislocation. A survival analysis with revision or removal of one or both components as the end point was performed according to the Kaplan and Meier method. The overall survival rate of the prosthesis was 75.2% at 19 years. The survival of 87.0% in the metal-backed group was higher than the 74.3% in the all-polyethylene group. Loosening of the all-polyethylene ulnar component was the main reason for deterioration in the long-term outcome. We conclude that the long-term results of the Kudo type-5 total elbow arthroplasty is acceptable and cemented fixation of metal-backed ulnar component had better long-term survival than the all-polyethylene component

Aims. We assessed the long-term (more than ten-year) outcomes of the Kudo type-5 elbow prosthesis in patients with rheumatoid arthritis (RA). Materials and Methods. We reviewed 41 elbows (Larsen Grade IV, n = 21; Grade V, n = 20) in 31 patients with RA who had undergone a Kudo type-5 total elbow arthroplasty (TEA) between 1994 and 2003, and had been followed up for more than ten years. The humeral component was cementless and the all-polyethylene ulnar component cemented in every patient. Clinical outcome was assessed using the Mayo elbow performance score. We calculated the revision rate and evaluated potential risk factors for revision. The duration of follow-up was a mean 141 months (120 to 203). Results. Aseptic loosening of the ulnar component occurred in 11 elbows. There was no radiolucency around any humeral component. There was one deep infection. The survival rate according to Kaplan-Meier survivorship analysis was 87.8% after five years and 70.7% after ten years. The range of extension/flexion was a mean -38° (-80° to 0°)/105° (30° to 150°) before surgery and -40° (-70° to -20°)/132° (100° to 150°) at the final follow-up, while the mean Mayo elbow performance score was 43 before surgery and 80 at final follow-up. Disease duration of RA up to the TEA of < 15 years and a pre-operative range of movement (ROM) of > 85° were significant risk factors for revision or aseptic loosening. Conclusion. Although Kudo type-5 prostheses gave satisfactory results in the short-term, aseptic loosening increased after five years. In most cases, elbow function was maintained in the long-term without loosening of the implant. A short duration from the onset of RA to TEA and a large pre-operative ROM were significant risk factors for revision or aseptic loosening. Cite this article: Bone Joint J 2017;99-B:818–23

Introduction: The Kudo total elbow prosthesis (TEP) is a well established implant, with good mid-term results. In the last decades this implant underwent several modifications. The last modification (type 5) has overcome the problems of stem breakage of the humeral component by modifications of the stem. The ulnar component can be placed with or without cement; the humeral component is always placed without cement. Aims of this study: To examine the mid-term results of the Kudo type 5 TEP and to compare the results of the uncemented Kudo total elbow prosthesis (TEP), with the hybrid Kudo TEP (uncemented humeral component and cemented ulnar component). Material and methods: Between 1994 and 2004 89 Kudo type 5 TEPs were placed for joint destruction due to rheumatoid arthritis (RA). The mean age of the patients was 55 years (range 21–84 years). Twenty-two prostheses were placed in males, 66 in females. Forty-nine TEPs (group 1) were fully uncemented and 40 TEPs (group 2) were hybrid (humeral component uncemented, ulnar component cemented). The groups were comparable as related to age, sex and indication for surgery. After implantation of the prosthesis a radiograph was made every two years or sooner when indicated. Evaluation took place after an average of 5.3 years of follow up (range 1.7–10.6 years) and consisted of a questionnaire, elbow function assessment and anteroposterior and lateral radiographs in a standard way. Pre- and postoperative range of motion was analysed with the paired T-test. Pain scores and EFAS scores postoperatively were analysed using the independent sample T-test. The survival of the prosthesis was calculated from the time of implant to the time of revision or occurrence of radiolucencies. Results: In group 1, seven ulnar components had to be revised due to aseptic loosening after a mean follow-up of 4 years (range 1.5–6.3 years). Three of these ulnar components were short-stemmed, four were long stemmed uncemented. In group 2 five patients died of an unrelated course and no revisions have taken place, one TEP is loose on X-ray (after two years) with a suspicion of septic loosening The EFAS scores (87 in group 1 and 91 in group 2) and range of motion (84 degrees in group 1 and 90 degrees in group 2) were the same in both groups. Conclusion: In this group of patients with RA the survival of the Kudo type 5 TEP with cemented ulnar component is better as compared to the uncemented ulnar component

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

A 55-year-old woman who was diagnosed as RA (stage, class ) in 1995 had undergone right total elbow arthroplasty (TEA) in October 2006. We implanted her prosthesis FINE ELBOW. ®. (Nakashima Medical, Japan). Prosthesis of the humerus side is made of Co-Cr-Mo, and the ulna side is of polyethylene. Radius side is metal back system which inserts a polyethylene joint part in metal holder made by Co-Cr-Mo. All components were fixed by cement. She complained her right elbow uncomfortable gradually from January 2008. X-ray radiograph showed loosening of the ulnar component. So we performed revision surgery using ulnar revision sack in May 2008. This ulnar component had only a product made in polyethylene and we inserted the component of the product made in the polyethylene in a metal sack. The operation was successed and now she does housework. We think that strength is not worthy of the ulnar component made by polyethylene in TEA for the patient with terrible joint destruction and high daily activity patient of rheumatoid arthritis

Determining and accurately restoring the flexion-extension axis of the elbow is essential for functional recovery after total elbow arthroplasty (TEA). We evaluated the effect of morphological features of the elbow on variations of alignment of the components at TEA. Morphological and positioning variables were compared by systematic CT scans of 22 elbows in 21 patients after TEA. There were five men and 16 women, and the mean age was 63 years (38 to 80). The mean follow-up was 22 months (11 to 44). The anterior offset and version of the humeral components were significantly affected by the anterior angulation of the humerus (p = 0.052 and p = 0.004, respectively). The anterior offset and version of the ulnar components were strongly significantly affected by the anterior angulation of the ulna (p < 0.001 and p < 0.001). The closer the anterior angulation of the ulna was to the joint, the lower the ulnar anterior offset (p = 0.030) and version of the ulnar component (p = 0.010). The distance from the joint to the varus angulation also affected the lateral offset of the ulnar component (p = 0.046). Anatomical variations at the distal humerus and proximal ulna affect the alignment of the components at TEA. This is explained by abutment of the stems of the components and is particularly severe when there are substantial deformities or the deformities are close to the joint. Cite this article: Bone Joint J 2015;97-B:1539–45

To measure any observed migration and rotation of humeral and ulnar components using radiostereometric analysis. From 2002–2004 in a prospective ongoing study, twelve elbows in patients treated with either a linked or unlinked Acclaim total elbow prosthesis were included in a radiostereometry study. Six tantalum markers were introduced into the humerus another three markers were located on a humeral component. Four markers were placed in to ulna and three markers located on the ulnar component. RSA radiographs were taken postoperatively, six, twelve and twenty-four months. The radiographs were digitised and analysed using UmRSA software. The relative movement of the humeral and ulnar implants with respect to the bone was measured. At twelve months, the largest segment translation of the humeral component was in the anterior/posterior direction with a mean of 0.44mm followed by medial/lateral translation of 0.39 mm; there was minimal proximal/ distal translation or with a mean of 0.16mm. Paired t-tests between twelve and 24 months segment translation data showed the mean differences to be no more than 0.056mm. The largest rotation at twelve months was anteversion/retroversion with a mean of 2.40deg, anterior tilt had a mean of 1.20deg and varus/valgus tilt was minimal mean 0.60deg. Mean difference between twelve and 24 months segment rotation was no more than 0.30deg. In contrast, humeral tip motion produced a mean of 1.1mm at 12 months dominated by movement in the plane horizontal plane with a mean difference at 24 months of 0.06mm. No patients could be measured for segment micromotion of the ulnar component due to technical difficulty in visualising tantalum markers in the ulna. Early micromotion of the Acclaim humeral implant occurs mostly by rotation about the vertical axis accompanied by anterior tilt. This motion reaches a plateau at 12 months after operation

Introduction: The design of the GSB III elbow arthroplasty has essentially remained unchanged since 1978 until recently. Because of observations of aseptic loosening of the ulnar component, the ulnar stem was changed in an excentric curved shape. The aim of the present study was to assess the clinical and radiographic outcome after more than 2 years of follow up with the new ulnar stem shape. Patients and methods: Between january 2000 and august 2002, 34 patients had undergone 36 total elbow replacements with the GSB III device with a new curved ulnar shape. Nineteen patients (20 elbows) underwent the operation for the first elbow arthroplasty and 16 patients underwent revision surgery. The mean follow up was 35 months (R: 25–49). The subjective satisfaction and pain intensity were assessed. Clinical exam recorded range of motion and strength. Radiographs were analysed for implant loosening and osteolysis. Results: There was a significant improvement of the average range of motion in flexion-extension from pre-operative 82degree to postoperative 105degree for all 36 elbows (t-test, p< 0,005). The 20 cases with primary elbow arthroplasty showed a significant improvement in the average range of flexion-extension from 76degree to 106degree (t-test, p< 0,001). The subjective assessment for satisfaction averaged 93 per cent at the time of follow up. For the 16 patients with revision elbow arthroplasty, the average range of flexion-extension improved from 90degree to 103degree (p< 0,01). The mean subjective satisfaction rated at 94 per cent. One case showed a radiolucent line at the ulnar component which remained unchanged at follow up. There was no component loosening. Discussion: The new excentric curved ulnar component shows no case of component loosening in our series for primary and revision elbow arthroplasty after 2 years. The range of motion and patient satisfaction are promising

Between 1993 and 2002, 58 GSB III total elbow replacements were implanted in 45 patients with rheumatoid arthritis by the same surgeon. At the most recent follow-up, five patients had died (five elbows) and six (nine elbows) had been lost to follow-up, leaving 44 total elbow replacements in 34 patients available for clinical and radiological review at a mean follow-up of 74 months (25 to 143). There were 26 women and eight men with a mean age at operation of 55.7 years (24 to 77). At the latest follow-up, 31 excellent (70%), six good (14%), three fair (7%) and four poor (9%) results were noted according to the Mayo elbow performance score. Five humeral (11%) and one ulnar (2%) component were loose according to radiological criteria (type III or type IV). Of the 44 prostheses, two (5%) had been revised, one for type-IV humeral loosening after follow-up for ten years and one for fracture of the ulnar component. Seven elbows had post-operative dysfunction of the ulnar nerve, which was transient in five and permanent in two. Despite an increased incidence of loosening with time, the GSB III prosthesis has given favourable mid-term results in patients with rheumatoid arthritis

To prevent insufficiency of the triceps after total elbow arthroplasty, we have, since 2008, used a triceps-sparing ulnar approach. This study evaluates the clinical results and post-operative alignment of the prosthesis using this approach. We reviewed 25 elbows in 23 patients. There were five men and 18 women with a mean age of 69 years (54 to 83). There were 18 elbows with rheumatoid arthritis, six with a fracture or pseudoarthrosis and one elbow with osteoarthritis. Post-operative complications included one intra-operative fracture, one elbow with heterotopic ossification, one transient ulnar nerve palsy, and one elbow with skin necrosis, but no elbow was affected by insufficiency of the triceps. Patients were followed for a mean of 42 months (24 to 77). The mean post-operative Japanese Orthopaedic Association Elbow Score was 90.8 (51 to 100) and the mean Mayo Elbow Performance score 93.8 (65 to 100). The mean post-operative flexion/extension of the elbow was 135°/-8°. The Manual Muscle Testing score of the triceps was 5 in 23 elbows and 2 in two elbows (one patient). The mean alignment of the implants examined by 3D-CT was 2.8° pronation (standard deviation (. sd). 5.5), 0.3° valgus (. sd. 2.7), and 0.7° extension (. sd. 3.2) for the humeral component, and 9.3° pronation (. sd. 9.7), 0.3° valgus (. sd. 4.0), and 8.6° extension (. sd. 3.1) for the ulnar component. There was no radiolucent line or loosening of the implants on the final radiographs. . The triceps-sparing ulnar approach allows satisfactory alignment of the implants, is effective in preventing post-operative triceps insufficiency, and gives satisfactory short-term results. . Cite this article: 2015;97-B:1096–1101

For the last few decades there have been several successful reports of TEA of both semi-constrained and non-linked prosthesis: pain relief, improvement of range of motion, functional improvement, and good survival rate of the components. However, other reports also showed that TEA had higher complication rates and lower survival rate than knee and hip joint replacement. To solve this problem some in vitro kinematic studies about TEA have been done and reported. But in vivo research has not been reported yet in the TEA, and it must be done for an essential solution. The aim of this study is to analyze in vivo motion of TEA components using two- to three- (2D/3D) registration technique. Six patients, six elbows were included in this study, having been treated with K-Elbow because of rheumatoid arthritis. The mean age at the operation was 47.2 years The mean duration between the operation and the fluoroscopic surveillance was 56.7 months. Under fluoroscopic examination in the sagittal plane, each patient was asked to bend his or her elbow from full extension to full flexion. Successive elbow motions were recorded as serial digital X-ray images using a digital image intensifier system. In vivo 3D poses of the humeral and the ulnar components were estimated using a 2D/3D registration technique, which uses CAD models to reproduce spatial postures of the humeral and the ulnar components from calibrated single view fluoroscopic images. The algorithm utilizes a feature-based approach to minimize distances between lines drawn from a contour found in the 2D image to the X-ray source and a surface CAD model with iterative computations. The amount of extension/flexion, varus/ valgus, and internal/external rotation angles of the ulnar component for the humeral component were evaluated quantitatively using Euler’s method. Results: The minimum flexion angle between the components was 33.6°± 18.5. Four of the six elbows exhibited inimum flexions of > 30° and the other two elbows exhibited < 30°. One elbow exhibited excessive flexion contracture > 50°. The maximum flexion angle was 126.7° ± 5.5. Only one elbow demonstrated flexion angle < 120° and all the others > 120°. The arc of range of motion was 93.0°±19.4. Concerning the valgus/varus angles between the components, there was a variation among patients. And from 30 to 120° flexion, there was a tendency to incline valgus with the increase of flexion. The mean valgus angle through flexion was −0.1°± 4.3 and the magnitude of displacement of valgus angle was 9.5° ± 4.0. In a similar way, there was a variation among patients about the rotation between the components. And from 30 to 120° flexion, there was a tendency to incline external rotation with the increase of flexion. The mean internal rotation through flexion was −1.0° ± 4.3 and the magnitude of displacement of internal rotation was 8.1°± 3.3

Mechanical loosening which begins with early-onset migration of the prosthesis is the major reason for failure of the Souter-Strathclyde elbow replacement. In a prospective study of 18 Souter-Strathclyde replacements we evaluated the patterns of migration using roentgen stereophotogrammetric analysis. We had previously reported the short-term results after a follow-up of two years which we have now extended to a mean follow-up of 8.2 years (1 to 11.3). Migration was assessed along the co-ordinal axes and overall micromovement was expressed as the maximum total point movement. The alignment of the prosthesis and the presence of radiolucent lines were examined on conventional standardised radiographs. All the humeral components showed increased and variable patterns of migration at the extended follow-up and four humeral components were revised. The maximum total point movement at two years in the revised prostheses was 1.8 mm (. sd. 1.0) and in the non-revised 0.7 mm (. sd. 0.5, p = 0.01). Most humeral components migrated into external rotation resulting in an anterior and varus tilt. The ulnar components remained stable

We assessed the long-term results of 58 Souter-Strathclyde total elbow replacements in 49 patients with rheumatoid arthritis. The mean length of follow-up was 9.5 years (0.7 to 16.7). The mean pre-operative Mayo Elbow Performance Score was 30 (15 to 80) and at final follow-up was 82 (60 to 95). A total of 13 elbows (22.4%) were revised, ten (17.2%) for aseptic loosening, one (1.7%) for instability, one (1.7%) for secondary loosening after fracture, and one elbow (1.7%) was removed because of deep infection. The Kaplan-Meier survival rate was 70% and 53% at ten and 16 years, respectively. Failure of the ulnar component was found to be the main problem in relation to the loosening. Anterior transposition of the ulnar nerve had no influence on ulnar nerve paresthaesiae in these patients

Between September 1993 and September 1996, we performed 34 Kudo 5 total elbow replacements in 31 rheumatoid patients. All 22 surviving patients were reviewed at a mean of 11.9 years (10 to 14). Their mean age was 56 years (37 to 78) at the time of operation. All had Larsen grade IV or V rheumatoid changes on X-ray. Nine (three bilateral replacements and six unilateral) had died from unrelated causes. One who had died before ten years underwent revision for dislocation. Of the 22 total elbow replacements reviewed six had required revision, four for aseptic loosening (one humeral and three ulnar) and two for infection. Post-operatively, one patient had neuropraxia of the ulnar nerve and one of the radial nerve. Two patients had valgus tilting of the ulnar component. With revision as the endpoint, the mean survival time for the prosthesis was 11.3 years (95% confidence interval (10 to 13) and the estimated survival of the prosthesis at 12 years according to Kaplan-Meier survival analysis was 74% (95% confidence interval 0.53 to 0.91). Of the 16 surviving implants, ten were free from pain, four had mild pain and two moderate. The mean arc of flexion/extension of the elbow was 106° (65° to 130°) with pronation/supination of 90° (30° to 150°) with the joint at 90° of flexion. The mean Mayo elbow performance score was 82 (60 to 100) with five excellent, ten good and one fair result. Good long-term results can be expected using the Kudo 5 total elbow replacement in patients with rheumatoid disease, with a low incidence of loosening of the components

This study reports our experience with total elbow replacement for fused elbows. Between 1982 and 2004, 13 patients with spontaneously ankylosed elbows were treated with a linked semi-constrained non-custom total elbow implant. The mean age at operation was 54 years (24 to 80). The stiffness was a result of trauma in ten elbows, juvenile rheumatoid arthritis in one, and rheumatoid arthritis in two. The patients were followed for a mean of 12 years (2 to 26) and were evaluated clinically using the Mayo Elbow Performance Score, as well as radiologically. A mean arc from 37° of extension to 118° of flexion was achieved. Outcomes were good or excellent for seven elbows at final review. Ten patients felt better or much better after total elbow replacement. However, there was a high complication rate and re-operation was required in over half of patients. Two developed peri-operative soft-tissue breakdown requiring debridement. A muscle flap with skin grafting was used for soft-tissue cover in one. Revision was undertaken in one elbow following fracture of the ulnar component. Three patients developed a deep infection. Three elbows were manipulated under anaesthesia for post-operative stiffness. Prophylactic measures for heterotopic ossification were unsuccessful. Total elbow replacement for the ankylosed elbow should be performed with caution. However, the outcome can be reliable in the long term and have a markedly positive impact on patient function and satisfaction. The high potential for complications must be considered. We consider total elbow replacement to be an acceptable procedure in selected patients with reasonable expectations

Introduction. Total Elbow Arthroplasty (TEA) is recognized as an effective treatment solution for patients with rheumatoid arthritis or for traumatic conditions. Current total elbow devices can be divided into linked or unlinked design. The first design usually presents a linking element (i.e. an axle) to link together the ulnar and humeral components to stabilize the joint; the second one does not present any linkage and the stability is provided by both intrinsic design constraints and the soft tissues. Convertible modular solutions allow for an intraoperative decision to link or unlink the prosthesis; the modular connections introduce however additional risks in terms of both mechanical strength and potential fatigue and fretting phenomena that may arise not only due to low demand activities loads, but also high demand (HD) ones that could be even more detrimental. The aim of this study was to assess the strength of the modular connection between the axle and the ulnar component in a novel convertible elbow prosthesis design under simulated HD and activities of daily living (ADLs) loading. Methods. A novel convertible total elbow prosthesis (LimaCorporate, IT) comprising both ulnar and humeral components that can be linked together by means of an axle, was used. Both typical ADLs and HD torques to be applied to the axle were determined based on finite element analysis (FEA); the boundary load conditions for the FEA were determined based on kinematics analysis on real patients in previous studies. The FEA resultant moment acting on the axle junction during typical ADLs (i.e. feeding with 7.2lbs weight in hand) was 3.2Nm while for HD loads (i.e. sit to stand) was 5.7 Nm. In the experimental setup, 5 axle specimens coupled with 5 ulnar bodies through a tapered connection (5 Nm assembly torque) were fixed to a torque actuator (MTS Bionix) and submerged in a saline solution (9g/l). A moment of 3.2 Nm was applied to the axle for 5M cycles through a fixture to test it under ADLs loading. After 5M cycles, the axles were analyzed with regards to fretting behavior and then re-assembled to test them against HD loading by applying 5.7 Nm for 200K cycles (corresponding to 20 years function). Results. All 5 samples withstood all 5.2M loading cycles without any mechanical failure. At the end of 5M cycles, each axle was still stable as the measured disassembly torque was 3.96 +/−0.18 Nm. Slight signs of fretting were detected on the tapered connection after 5M cycles, however they did not compromise the mechanical connection nor the stability. Discussion and Conclusions. Currently there are no reference standards that properly define protocols for biomechanical testing of elbow prostheses. In the present study, a test to mechanically assess the strength of an axle connection under both typical ADLs and HD loads was set. The connection was able to withstand the imposed conditions. In general, testing of TEA devices should include not only standard ADLs loads but also HD loads, which could be more detrimental for the long-term survivorship. For any figures or tables, please contact authors directly