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).

Aims. For paediatric and adolescent patients with growth potential, preservation of the physiological joint by transepiphyseal resection (TER) of the femur confers definite advantages over arthroplasty procedures. We hypothesized that the extent of the tumour and changes in its extent after neoadjuvant chemotherapy are essential factors in the selection of this procedure, and can be assessed with MRI. The oncological and functional outcomes of the procedure were reviewed to confirm its safety and efficacy. Methods. We retrospectively reviewed 16 patients (seven male and nine female, mean age 12.2 years (7 to 16)) with osteosarcoma of the knee who had been treated by TER. We evaluated the MRI scans before and after neoadjuvant chemotherapy for all patients to assess the extent of the disease and the response to treatment. Results. The mean follow-up period was 64.3 months (25 to 148) after surgery and no patients were lost to follow-up. On MRI evaluation, 13 tumours were near but not in contact with the physes and three tumours were partially in contact with the physes before neoadjuvant chemotherapy. Bone oedema in the epiphysis was observed in eight patients. After neoadjuvant chemotherapy, bone oedema in the epiphysis disappeared in all patients. In total, 11 tumours were not in contact and five tumours were in partial contact with the physes. The postoperative pathological margin was negative in all patients. At the last follow-up, 12 patients were continuously disease-free and three had no evidence of disease. One patient died due to the disease. Functionally, the patients with retained allograft or recycled autograft had a mean knee range of flexion of 126° (90° to 150°). The mean Musculoskeletal Tumor Society functional score was 27.6 (23 to 30). Conclusion. TER is an effective limb-salvage technique for treating malignant metaphyseal bone tumours in paediatric and young osteosarcoma patients with open physes when a good response to chemotherapy and no progression of the tumour to the epiphysis have been confirmed by MRI. Cite this article: Bone Joint J 2020;102-B(6):772–778

Introduction. The interaction between the mobile components of total elbow replacements (TER) provides additional constraint to the elbow motion. Semi-constrained TER depend on a mechanical linkage to avoid dislocation and have greater constraint than unconstrained TER that rely primarily in soft tissue for joint stability. Greater constraint increases the load transfer to the implant interfaces and the stresses in the polyethylene components. Both of these phenomena are detrimental to the longevity of TER, as they may result in implant loosening and increased damage to the polyethylene components, respectively[1]. The objective of this work was to compare the constraint profile in varus-valgus and internal-external rotation and the polyethylene stresses under loads from a common daily activity between two semi-constrained TER, Coonrad/Morrey (Zimmer-Biomet) and Discovery® (DJO), and an unconstrained TER, TEMA (LimaCorporate). Methods. We developed finite element (FE) models of the three TER mechanisms. To reduce computational cost, we did not include the humeral and ulnar stems. Materials were linear-elastic for the metallic components (E. Ti6Al4V. =114.3 GPa, E. CoCr. =210 GPa, v=0.33) and linear elastic-plastic for the polyethylene components (E=618 MPa, v=0.46; S. Y. =22 MPa; S. U. =230.6 MPa; ε. U. =1.5 mm/mm). The models were meshed with linear tetrahedral elements of sizes 0.4–0.6 mm. We assumed a friction coefficient of 0.02 between metal and polyethylene. In all simulations, the ulnar component was fixed and the humeral component loaded. We computed the constraint profiles in full extension by simulating each mechanism from 8° varus to 8° valgus and from 8° internal to 8° external rotation. All other degrees-of-freedom except for flexion extension were unconstrained. Then, we identified the instant during feeding that generated the highest moments at the elbow[2], and we applied the joint forces and moments to each TER to evaluate the stresses in the polyethylene. To validate the FE results, we experimentally evaluated the constraint of the design with highest polyethylene stresses in pure internal-external rotation and compared the results against those from a FE model that reproduced the experimental setup (Fig.1-a). Results. For each design, the constraint profiles in varus-valgus (Fig.2-a) were similar to internal-external rotation (Fig.2-b). All designs showed a lax zone in which the mechanisms rotated freely and an engagement zone in which the mobile components contacted, resulting in load transfer. The laxity of the Coonrad/Morrey and the Discovery® was similar and lower than that of the TEMA. After engagement, the stiffness of the TEMA was less than that of the Discovery® and the Coonrad/Morrey. The TEMA showed the lowest polyethylene stresses of all three designs under demanding loads during feeding. Only Discovery® and Coonrad/Morrey had zones reaching permanent deformation (Fig.3). For the Coonrad/Morrey, with the highest polyethylene stresses, the experimental and computational constraint profiles were similar (Fig.1-b). Discussion. The TEMA unconstrained design transferred less moment than semi-constrained designs, reducing the burden on the implant interfaces. Moreover, the TEMA design had lower stresses in the polyethylene components due to the combination of less constraint and a lack of sharp edges on the articular surfaces. For any figures or tables, please contact the authors directly

Aims

Arthroplasty for end-stage hallux rigidus (HR) is controversial. Arthrodesis remains the gold standard for surgical treatment, although is not without its complications, with rates of up to 10% for nonunion, 14% for reoperation and 10% for metatarsalgia. The aim of this study was to analyze the outcome of a double-stemmed silastic implant (Wright-Medical, Memphis, Tennessee, USA) for patients with end-stage HR.

Aims

The aim of this study was to assess the current evidence relating to the benefits of virtual reality (VR) simulation in orthopaedic surgical training, and to identify areas of future research.

As a treatment for end-stage elbow joint arthritis, total elbow replacement (TER) results in joint motions similar to the intact joint; however, bearing wear, excessive deformations and/or early fracture may necessitate early revision of failed implant components. Compared to hips, knees and shoulders, very little research has been focused on the evaluation of the outcomes of TER, possible failure mechanisms and the development of optimal designs. The current study aims to develop computational models of TER implants in order to analyze implant behaviour; considering contact stresses, plastic deformations and damage progression. A geometrical model of a TER assembly was developed based on measurements from a Coonrad-Morrey TER implant (Zimmer, Inc., Warsaw, IN). Ultra high molecular weight polyethylene (UHMWPE) nonlinear elasto-plastic material properties were assigned to the humeral and ulnar bushings. A frictional penalty contact formulation with a coefficient of friction of 0.04 was defined between all of the surfaces of the model to take into account every possible interaction between different implant components in vivo. The loading scenario applied to the model includes a flexion-extension motion, a joint force reaction with variable magnitude and direction and a time varying varus-valgus (VV) moment with a maximum magnitude of 13 N.m, simulating a chair-rise scenario as an extreme loading condition. An explicit dynamic finite element solver was used (ABAQUS Explicit, Dassault Systèmes, Vélizy-Villacoublay, France), due to improved capabilities when performing large deformation analyses. Model results were compared directly with corresponding experimental data. Experimental wear tests were performed on the abovementioned implants using a VIVO (AMTI, Watertown, MA) six degree-of-freedom (6-DOF) joint motion simulator apparatus. The worn TER bushings were scanned after the test using micro computed tomography (µCT) imaging techniques, and reconstructed as 3D models. Comparisons were made based on the sites of damage and deformed geometries between the numerical results and experimental test data. In addition to that, parametric geometrical models were developed using worn geometry of the retrievals in order to account for primary wear and deformations while simulating long-term contact stress and secondary damage progression on the bushings (Fig. 1). Contact pressure distributions on the humeral and ulnar bushings correlate with the sites of damage as represented by the µCT data and gross observation of clinical retrievals. Furthermore, deformation patterns and kinematics of the components are in good agreement with the experimental results (Fig.2). Excessive plastic deformations are evident in both the numerical and the experimental results close to the regions with high contact pressures. Simulating parametric initially-worn geometries results in the formation of secondary damage zones, as well as redistribution of contact stresses and contact locations (Fig. 3). The results demonstrate UHMWPE bushing damage due to different loading protocols. Numerical results demonstrate strong agreement with experimental data based on the location of deformation and creep on bushings and exhibit promising capabilities for predicting the damage and failure mechanisms of TER implants. For figures/tables, please contact authors directly.

TER is a viable surgical option in patients with advanced RA with painful stiff elbows. We retrospectively analysed 22 TER performed in 21 patients over a 12 year period by a single surgeon, with a mean follow up of 64 months (10–145). Disability of the arm, shoulder and hand (DASH) scores were performed pre-operatively and post-operatively in patients through postal questionnaires. The mean age was 59.1 years (32–78). There were 12 women and 9 men. The mean pre-operative DASH score was 72.3 (45.0–91.7) and post-operatively improved to 46.8 (21.7–94.2). Complications included infection, peri-operative fracture, peri-prosthetic fracture and aseptic loosening. There were 6 revisions performed, 2 for peri-prosthetic fracture, 2 for infection, 1 for intra-operative fracture and 1 for symptomatic aseptic loosening. Four patients had died due to unrelated causes. The 10 year survival rate with symptomatic aseptic loosening as the end point was 93% and revisions for all reasons was 69%. Follow up radiographs (in those without revision) were reviewed and 10 had satisfactory positioning of the prosthesis, 5 had loosening of the humeral or radial component and 1 had inadequate cement mantle but was clinically asymptomatic. TER is a rewarding procedure in with advanced RA. Our results are comparable to other published studies

We retrospectively analysed a single surgeon series of 22 TER in 21 patients over a 12 year period. The mean age and follow up was 59.1 years and 64 months respectively. DASH scores assessed pre and post op confirmed a significant improvement. Complications included infection, intra-operative fracture, peri-prosthetic fracture and aseptic loosening. 6 revisions were performed for various reasons.4 patients had died due to unrelated causes. The 10 year survival rate with symptomatic aseptic loosening as the end point was 93%. 5 patients had radiological loosening but were clinically asymptomatic. TER is a rewarding procedure in with advanced RA

Non-tuberculous mycobacterial (NTM) infection of the musculoskeletal tissue is a rare disease. An early and accurate diagnosis is often difficult because of the indolent clinical course and difficulty of isolating pathogens. Our goal was to determine the clinical features of musculoskeletal NTM infection and to present the treatment outcomes. A total of 29 patients (nine females, 20 males between 34 and 85 years old, mean age 61.7 years; 34 to 85) with NTM infection of the musculoskeletal system between 1998 to 2011 were identified and their treatment retrospectively analysed. Microbiological studies demonstrated NTM in 29 patients: the isolates were Mycobacterium intracellulare in six patients, M. fortuitum in three, M. abscessus in two and M. marinum in one. In the remaining patients we failed to identify the species. The involved sites were the hand/wrist in nine patients the knee in five patients, spine in four patients, foot in two patients, elbow in two patients, shoulder in one, ankle in two patients, leg in three patients and multiple in one patient. The mean interval between the appearance of symptoms and diagnosis was 20.8 months (1.5 to 180). All patients underwent surgical treatment and antimicrobial medication according to our protocol for chronic musculoskeletal infection: 20 patients had NTM-specific medication and nine had conventional antimicrobial therapy. At the final follow-up 22 patients were cured, three failed to respond to treatment and four were lost to follow-up. Identifying these diseases due the initial non-specific presentation can be difficult. Treatment consists of surgical intervention and adequate antimicrobial therapy, which can result in satisfactory outcomes.

Cite this article: Bone Joint J 2014;96-B:1561–5.

Medium-term results of the Discovery elbow replacement are presented. We reviewed 51 consecutive primary Discovery total elbow replacements (TERs) implanted in 48 patients. The mean age of the patients was 69.2 years (49 to 92), there were 19 males and 32 females (37%:63%) The mean follow-up was 40.6 months (24 to 69). A total of six patients were lost to follow-up. Statistically significant improvements in range movement and Oxford Elbow Score were found (p < 0.001). Radiolucent lines were much more common in, and aseptic loosening was exclusive to, the humeral component. Kaplan–Meier survivorship at five years was 92.2% (95% CI 74.5% to 96.4%) for aseptic loosening. In four TERs, periprosthetic infection occurred resulting in failure. A statistically significant association between infection and increased BMI was found (p = 0.0268). Triceps failure was more frequent after the Mayo surgical approach and TER performed after previous trauma surgery. No failures of the implant were noted. . Our comparison shows that the Discovery has early clinical results that are similar to other semi-constrained TERs. We found continued radiological surveillance with particular focus on humeral lucency is warranted and has not previously been reported. Despite advances in the design of total elbow replacement prostheses, rates of complication remain high. Cite this article: Bone Joint J 2014;96-B:1359–65

Summary Statement. Discovery system produced effective functional improvement in both primary and revision total elbow replacement. The incidence of major complications was in an acceptable range. Introduction. The search for the ideal elbow prosthesis continues as instability and loosening remain the prime reasons for total elbow replacement (TER) failure. The Discovery Elbow System (Biomet) is one of the latest generations of linked prosthesis and has been used in UK since 2003. We report outcome of TER using this system. Methods. A total of 100 TERs (75 primary, 25 revisions) were performed between 2003 and 2010. The main primary underlying pathologies for TER were advanced rheumatoid arthritis (N=58), osteoarthritis (N=35), acute fractures (N=7). There were 60 female and 40 male patients with an average age of 62 years. The outcome assessment included pain, patient satisfaction, Liverpool Elbow Score (LES), range of movement, and imaging during a mean follow-up period of 48.5 months. Major complications are also reported. Results. For the whole patient group (primary + revision), the LES was significantly (p<0.001) improved from 3.79+/−1.71 to 6.36+/−1.85There were significant improvements in elbow flexion from 100°+/−24 to 118°+17, supination from 38°+/−26 to 50°+/−25 and pronation from 48°+/−22 to 61°+/−21. Mean improvement in flexion-extension and pronation-supination arc was 20° and 25°, respectively. 64% of cases were completely pain-free and at the final follow-up (compared to 7% preoperatively). Only 6% of patients scored “Not Satisfied” at the final follow-up. LES improvement was significantly higher in the primary TER compared to revision TER (p<0.05). Imaging reviewed for 60 cases showed loosening in 4% of patients. Other main complications included deep infection (N=2), ulnar neuropathy (N=3), pre-prosthetic fracture (N=2), and prosthetic failure (N=1). Discussion. TER using the Discovery Elbow System is an effective arthroplasty in terms of functional improvement, pain relief and range of motion in both primary and revision patients. TER resulted in no/mild pain in 78% of cases. Patients undergoing Acclaim, Souter-Strathclyde, GSB III, and Coonrad-Morrey TER have been reported to have no/mild pain in 64%, 67%, 50–92% and 60–100% of cases, respectively. A 20° improvement in flexion-extension arc is comparable to that of Acclaim (23°), Souter-Strathclyde (15°), GSBIII (19–33°), and Coonrad-Morrey (17–26°) TER. An improvement of 25° in pronation-supination arc in our series is also comparable to that of 21–28° reported the Coonrad-Morrey and 27–33° for Discovery prostheses. An infection rate of 2% is lower than several other reports for GSB III TER (7–11%) and Coonrad-Morrey (6–8%). The incidence of persistent ulnar neuropathy (3%) was lower compared to GSBIII TER (11–14%), Coonrad-Morrey (12–26%), and Acclaim (8%)

We determined the short-term clinical outcome and migration within the bone of the humeral cementless component of the Instrumented Bone Preserving (IBP) total elbow replacement in a series of 16 patients. There were four men and 12 women with a mean age at operation of 63 years (40 to 81). Migration was calculated using radiostereometric analysis. There were no intra-operative complications and no revisions. At two-year follow-up, all patients showed a significant reduction in pain and functional improvement of the elbow (both p < 0.001). Although ten components (63%) showed movement or micromovement during the first six weeks, 14 (88%) were stable at one year post-operatively. Translation was primarily found in the proximal direction (median 0.3 mm (interquartile range (IQR) -0.09 to 0.8); the major rotational movement was an anterior tilt (median 0.7° (IQR 0.4° to 1.6°)). One malaligned component continued to migrate during the second year, and one component could not be followed beyond three months because migration had caused the markers to break off the prosthesis.

This study shows promising early results for the cementless humeral component of the IBP total elbow replacement. All patients had a good clinical outcome, and most components stabilised within six months of the operation.

Cite this article: Bone Joint J 2014;96-B:229–36.

The February 2014 Shoulder & Elbow Roundup³⁶⁰ looks at: whether arthroscopic acromioplasty is a cost-effective intervention; shockwave therapy in cuff tear; whether microfracture relieves short-term pain in cuff repair; the promising early results from L-PRF augmented cuff repairs; rehabilitation following cuff repair; supination strength following biceps tendon rupture; whether longer is better in humeral components; fatty degeneration in a rodent model; and the controversial acromioclavicular joint dislocation.

Treatment of an infected total elbow replacement (TER) is often successful in eradicating or suppressing the infection. However, the extensor mechanism may be compromised by both the infection and the surgery. The goal of this study was to assess triceps function in patients treated for deep infection complicating a TER. Between 1976 and 2007 a total of 217 TERs in 207 patients were treated for infection of a TER at our institution. Superficial infections and those that underwent resection arthroplasty were excluded, leaving 93 TERs. Triceps function was assessed by examination and a questionnaire. Outcome was measured using the Mayo Elbow Performance Score (MEPS). Triceps weakness was identified in 51 TERs (49 patients, 55%). At a mean follow-up of five years (0.8 to 34), the extensor mechanism was intact in 13 patients, with the remaining 38 having bone or soft-tissue loss. The mean MEPS was 70 points (5 to 100), with a mean functional score of 18 (0 to 25) of a possible 25 points. Infection following TER can often be eradicated; however, triceps weakness occurs in more than half of the patients and may represent a major functional problem. Cite this article: Bone Joint J 2014;96-B:82–7

Purpose of study:. Total elbow replacement (TER) is one of the surgical options for treatment of severe haemophilic arthropathy of the elbow. There are only a few small series described in the literature. The goal of our study was to evaluate our cases and add these data to the known literature. Methods:. A retrospective analysis of a series of 8 TER's (5 patients) was performed. Patients were seen in clinic and evaluated by physical examination, a VAS score for pain, the Mayo Elbow Performance Score (MEPS, 100 points=excellent) and X-rays of the affected elbow. Mean follow-up was 91 (4–236) months, and 103 months when we excluded a patient with only 4 months follow-up. Primary diagnosis was Hemophilia type A in 4 and von Willebrand disease in 1 patient. 2 patients were positive for Hepatitis C and 3 for HIV. Mean age at primary surgery was 46.7 (31.8–63.1) years. Results:. The mean VAS score for pain improved from 7.9 to 0.5 and the mean Mayo Elbow Performance Score from 36 to 93. The arc for flexion/extension improved from 68° to 91° and from to 75° to 153° for pro- and supination. Revision surgery was performed in 3 out of 8 TER's; 1 because of loosening of the humeral component (18.7 years postop), 1 for loosening of the ulnar component (9.9 years postoperatively) and 1 due to a late deep infection, 4 years postoperatively. The last case was treated with an excision arthroplasty, the others with a revision. No replacement currently shows signs of loosening. Conclusion:. This is a small retrospective study, as are the other studies on TER in haemophilic patients. It demonstrated excellent clinical outcome and an acceptable survival rate of a TER, with a mean follow-up of 7.6 years even in this young patient population

The June 2013 Shoulder & Elbow Roundup³⁶⁰ looks at: whether suture anchors are still the gold standard; infection and revision elbow arthroplasty; the variable success of elbow replacements; sliding knots; neurologic cuff pain and the suprascapular nerve; lies, damn lies and statistics; osteoarthritis; and one- or two-stage treatment for the infected shoulder revision.

Introduction. The aim of this study is to analyse the effect of the degree of coverage of the Total Elbow implant with cement and the significance of cementation index as a predictor of failure. Material/methods. Fifty elbows in forty seven patients who had undergone the Coonrad-Morrey TER were included in the study. The post-operative radiographs were evaluated for the cementation index. Failures and revisions were documented. Statistical analysis was done to evaluate the cementation index as a predictor of failure. Results. The mean period of follow up was 4.67 ± 2.85 years. The mean cementation index of the humerus (CIH) was 1.22 ± 0.28 (range 0.7 to 2.1). The mean cementation index of the ulna (CIU) was 1.10 ± 0.18 (range 0.77 to 1.72). The Kolmogorov-Smirnov test, used to test the type of distribution, showed that both the indices had a normal distribution (p > 0.05). Both the humeral and ulnar cementation indices were not found to be statistically significant predictors of failure (p > 0.05). Conclusions. The cementation index is an objective method of assessment of the coverage of the implant with cement. In the present series, the cementation index of the humerus varied from 0.7 to 2.1 and that of the ulna varied from 0.77 to 1.72 but both were not found to be statistically significant. A larger study with adequate follow-up should be done to establish the minimum cement mantle that can be considered adequate for the long term survivorship of the prosthesis

Background. The quest for the perfectly designed elbow prosthesis continues as instability and loosening remain the foremost reasons for the failure of total elbow replacement (TER). The Discovery® Elbow System (Biomet, UK) (Figure 1), which has been used in UK since 2003, is one of the latest generations of linked prosthesis. This system was designed to decrease polyethylene-bushing wear, improve anatomic stem design, restore elbow joint biomechanics, and produce a hinge that could be easily revised. This report describes the short term outcome of TER using the Discovery® Elbow System. Patients and Methods. A total of 60 TERs including 48 primary and 12 revisions were performed between 2003 and 2008. Patients included 21 males (37%) and 36 females (63%) with a mean age of 63 years. The indications for primary TER were advanced rheumatoid arthritis (n=19), osteoarthritis (n=16), post traumatic osteoarthritis (n=9), acute fractures (n=3), and haemophilic arthropathy (n=1). The outcome was assessed using pain score, Liverpool Elbow Score (LES), and range of movement during a mean follow-up of 26 months. Associated complications were documented. Radiological assessment included evaluation for loosening, instability and periprosthetic fractures. Results. The mean LES was significantly (p<0.001) improved from 3.8 (±1) pre-operatively to 6.9 (±2) at the final follow- up. Significant improvements were noted in elbow flexion from 100° (±22) to 120° (±15), supination from 41° (±28) to 65° (±20) and pronation from 52° (±22) to 72° (±18). There was no significant change in elbow extension. Mean improvement in flexion-extension and pronation-supination arc was 22° and 44°, respectively. 46 cases (77%) were completely pain-free at the final follow-up. The main complications included deep infection (4 cases – treated with staged revision TER), postoperative ulnar neuropathy (3 cases–treated with decompression), intra-operative fractures of medial condyle (3 cases – treated non-operatively with brace), and elbow haemarthrosis (1 case). Discussion. TER with Discovery® Elbow System resulted in either no pain or mild pain in 87% of cases. Patients undergoing Acclaim, Souter-Strathclyde, GSB III, and Coonrad-Morrey TER have been reported to have no/mild pain in 64%, 67%, 50–92% and 60–100% of cases, respectively. A 22° improvement in flexion-extension arc is comparable to that of Acclaim (23°), Souter-Strathclyde (15°), GSB III (19–33°), and Coonrad-Morrey (17–26°) TER. An improvement of 44° in pronation-supination arc in our series is also comparable to that of 31–67° reported for GSB III and higher than the Coonrad-Morrey prosthesis (21–28°). In terms of complications, an infection rate of 6.7% is consistent with those reported for GSB III TER (7–11%) and Coonrad-Morrey (6–8%). The incidence of persistent ulnar neuropathy was lower compared to GSB III TER (11–14%), Coonrad-Morrey (12–26%), and Acclaim (8%). While the survival of Discovery TER was 93%, the survival of GSB III (5–6 years) and Coonrad-Morrey (5 years) has been reported as 71–85% and 72–90%. The results indicate that Discovery® Elbow System is an effective device for total elbow arthroplasty in terms of functional improvement, pain relief and range of motion at short-term follow-up