Delta Xtend Research Articles

Influence of design features and brand of reverse shoulder arthroplasties on survivorship and reasons for revision surgery: results of 5,494 arthroplasties with up to 15 years' follow-up reported to the Norwegian Arthroplasty Register 2007-2022.

We aimed to report the survival of different reverse shoulder arthroplasty (RSA) designs and brands, and factors associated with revision. The secondary aim was to evaluate the reasons for revision. We included 4,696 inlay and 798 onlay RSAs reported to the Norwegian Arthroplasty Register (NAR) 2007-2022. Kaplan-Meier estimates of survivorship and Cox models adjusted for age, sex, diagnosis, implant design, humeral fixation, and previous surgery were investigated to assess revision risks. The reasons for revision were compared using competing risk analysis. Overall, the 10-year survival rate was 94% (confidence interval [CI] 93-95). At 5 years all brands exceeded 90%. Compared with Delta Xtend (n = 3,865), Aequalis Ascend Flex (HR 2.8, CI 1.7-4.6), Aequalis Reversed II (HR 2.2, CI 1.2-4.2), SMR (HR 2.5, CI 1.3-4.7), and Promos (HR 2.2, CI 1.0-4.9) had increased risk of revision. Onlay and inlay RSAs had similar risk of revision (HR 1.2, CI 0.8-1.8). Instability and deep infection were the most frequent revision causes. Male sex (HR 2.3, CI 1.7-3.1), fracture sequelae (HR 3.1, CI 2.1-5.0), and fractures operated on with uncemented humeral stems had increased risk of revision (HR 3.5, CI 1.6-7.3). We found similar risk of revision with inlay and onlay designs. Some prosthesis brands had a higher rate of revision than the most common implant, but numbers were low.

Do the humeral radiographic changes at 5-year follow-up affect the clinical outcomes of press-fit humeral stems in primary reverse shoulder arthroplasties?

The purposes of this study were to analyze and compare the functional outcomes and radiological changes around the press-fit humeral components in two contemporary medialized reverse total shoulder arthroplasty (RTSA) systems at a minimum of 5-year follow-up. Between December 2003 and December 2015, 249 consecutive RTSAs were performed at our hospital. Of these, 68 primary uncemented RTSA met our inclusion criteria. The Constant-Murley score (CMS), the modified Constant score, a visual analog scale (VAS) and active shoulder range of motion (ROM) were measured pre- and postoperatively. Radiological assessment was performed by plain radiographs at a minimum of 5years postoperatively. At a mean follow-up of 80.2months, there was no significant difference (p = .59) between the postoperative functional scores and range of motion of the two groups (Delta Xtend and Lima SMR). Radiological data of stress-shielding were observed in 38 patients (55.9%) being slightly more frequent in the Lima SMR group (21 patients) than in the Delta Xtend group (17 patients) (p = .62). Our study shows that the good functional results are similar between the two uncemented RTSA systems used and that they do not depend on the presence of radiological changes (stress-shielding) in the humeral stem at a minimum 5-year follow-up.

Reverse shoulder arthroplasty with a 155° neck-shaft angle inlay implant design without reattachment of the subscapularis tendon results in satisfactory functional internal rotation and no instability: a cohort study

BackgroundThe aim of this study was to use the Activities of Daily Living which require Internal Rotation (ADLIR) questionnaire to assess the functional internal rotation in patients who had undergone reverse shoulder arthroplasty (RSA) without reattachment of the subscapularis (SSc) tendon at a minimum follow-up of 2 years. The secondary aim was to report the objective range of motion (ROM) and the rate of postoperative instability.Materials and methodsAll consecutive primary RSA procedures without reattachment of the SSc tendon that were performed using a Delta Xtend prosthesis (an inlay system with a 155° neck-shaft angle) between January 2015 and December 2020 were identified to ensure a minimum follow-up of 2 years. Patients were contacted and requested to fill in several questionnaires, including the ADLIR and Auto-Constant scores.ResultsIn total, 210 patients met the inclusion criteria; among those patients, 187 could be contacted and 151 completed questionnaires (response rate: 81%). The SSc tendon was fully detached without repair in all cases, and a superolateral approach was used in 130 (86%) cases. The median follow-up was 4.5 years (range: 2.0–7.6). At final follow-up, the mean ADLIR score was 88/100 (interquartile range (IQR): 81–96). The median level reached in internal rotation was the 3rd lumbar vertebra (IQR: lumbosacral region—12th thoracic vertebra). Of the 210 eligible patients, one required a revision for a dislocation within the first month after primary surgery. With regards to regression analysis with ADLIR score as the outcome, none of the factors were associated with the ADLIR score, although age and smoking approached significance (0.0677 and 0.0594, respectively). None of the explanatory variables were associated with ROM in internal rotation (p > 0.05).ConclusionsThis study demonstrates that satisfactory ADLIR scores and internal rotation ROM were obtained at mid-term follow-up after RSA leaving the SSc detached. Leaving the SSc detached also did not lead to high instability rates; only one out of 210 prostheses was revised for dislocation within the first month after primary surgery.Level of evidence III.

The Delta III and Delta Xtend reverse shoulder arthroplasty—risk of revision and failure mechanisms: a report on 3650 cases from the Norwegian Arthroplasty Register 1994-2021

The Delta reverse shoulder arthroplasty (RSA) is commonly used worldwide and is the most frequently used RSA in Norway. The aim of this registry-based study was to report 10- and 20-year implant survival, risk of revision, and reasons for revision in 2 consecutive time periods for Delta III (1994-2010) and Delta Xtend (2007-2021) prostheses. We included 3650 primary RSAs reported to the Norwegian Arthroplasty Register: 315 Delta III (42% cemented stems) and 3335 Delta Xtend (88% cemented stems). We used Kaplan-Meier analyses to investigate implant survival. The reasons for revision were compared for the 2 designs and fixation technique. Factors that could influence the risk of revision, such as implant design, fixation technique, and patient factors, were investigated using Cox regression analyses with adjustments for age, sex, and diagnosis. Patients operated with Delta III were more likely to be diagnosed with inflammatory disease or fracture sequela, whereas acute fracture, osteoarthritis, and cuff arthropathy were the most frequent indications for Delta Xtend. Ten-year survival was 93.0% (95% confidence interval [CI]: 87.0-99.0) (cemented stem) and 81.6% (95% CI: 75.3-87.9) (uncemented stem) for Delta III and 94.7% (95% CI: 93.3-96.1) (cemented stem) and 95.7% (95% CI: 88.3-100) (uncemented stem) for Delta Xtend. Twenty-year survival for Delta III (uncemented stem) was 68.2% (95% CI: 58.8-77.6). Compared with DeltaXtend (cemented stem) at 10-year follow-up, we found a higher risk of revision for Delta III (uncemented stem) (hazard ratio [HR]: 2.9, 95% CI: 1.7-5.0), whereas no significant difference was found for Delta III (cemented stem) and Delta Xtend (uncemented stem). The most common reason for revision of Delta III (uncemented stem) was glenoid loosening followed by deep infection and instability. Instability was the most frequent revision cause for Delta Xtend (both cemented and uncemented stem). Men had an overall higher revision risk than women (HR: 2.8 [95% CI: 2.0-3.9]), and patients with fracture sequela had increased risk for revision (HR: 2.8, 95% CI: 1.7-4.7) compared with patients with osteoarthritis. We found that Delta III (uncemented stem) had a higher risk of revision compared with Delta Xtend (cemented stem). The risk of revision for glenoid component loosening was lower for Delta Xtend, but revisions due to instability/dislocation are still a concern. This register study cannot determine whether the differences found were caused by differences in implant design or other factors that changed during the study period. Risk of revision may have been affected by the indication for primary operation.

Functional and radiographic outcomes of reverse shoulder arthroplasty with a minimum follow-up of 10 years

The use of reverse shoulder arthroplasty (RSA) is becoming increasingly prevalent. However, few studies have been published reporting the long-term outcomes of RSA. This study aims to report the clinical, radiographic, and patient-reported outcomes of the Delta Xtend reverse shoulder prosthesis, performed by a single surgeon and with a minimum follow-up of 10years. All RSA procedures performed between 2005 and 2012 were identified. Patients were contacted and invited for a follow-up visit including clinical assessment, radiographs, and patient-reported outcome measures. Patients with a follow-up of less than 10years were excluded. The revision-free implant survival was calculated at 10years. Between 2005 and 2012, 119 procedures in 116 patients meeting inclusion criteria were identified. Of these patients, 35 were deceased before reaching the 10-year follow-up and 23 could not be reached. In total, 63 RSAs could be included in 61 patients (response rate: 75%). The median follow-up was 11.7years (interquartile range [IQR]: 10.5-13.2). Of the 61 patients, 7 patients underwent a revision after a median of 3years (IQR: 0.2-9.8) during the total follow-up period. The 10-year implant survival was 94% (95% confidence interval: 84-98). At final follow-up, the median anterior elevation was 135° (IQR: 130°-160°), the median abduction was 120° (IQR: 100°-135°), and the median level reached with internal rotation was L5 (IQR: sacrum-L5). The median Auto-Constant score was 68 (IQR: 53-78), the median Subjective Shoulder Value was 80 (IQR: 70-93), and the median pain score was 0.2/10 (IQR: 0-2). In total, radiographs could be obtained in 25 patients (40%). Scapular notching occurred in 10 patients (40%), which was classified as Sirveaux-Nerot grade IV in 3 patients (12%). Ossification occurred in 10 patients (40%), and stress shielding in 2 patients (8%). Radiolucencies were observed around the humeral component in 24 patients (96%) and around the glenoid component in 13 patients (52%). The long-term results of RSA with a Delta Xtend prosthesis are favorable, with long-term improvement in range of motion and patient-reported outcome measures, and a satisfactory implant survival rate. Interestingly, the radiographical analysis showed high prevalence of signs associated with loosening, which did not seem to translate to high complication rates or inferior results.

Early results with the Delta Xtend shoulder arthroplasty as primary treatment or proximal humerus reoperation

Reverse total shoulder arthroplasty (RTSA) has established itself as the standard of care for the treatment of rotator cuff arthropathy (RCA). Gradually, its share increased in relation to all used shoulder arthroplasties mainly in cases of complex proximal humeral fractures (PHFx).
 Method: From November 2019 to December 2021, 39 patients at mean age of 72.8 years were operated via RTSA Delta Xtend by one surgeon in our clinic. 32 of them were followed for a period between 12 ÷ 30 months. At postoperative visits, function and pain were assessed using the Constant-Murley score (CMS), DASH score and recorded range of motion (ROM). Level of satisfaction was assessed using the visual analogue scale (VAS).
 Results: The mean CMS recorded at the last visit was 82.6, and the relative one 90.8%. The achieved anterior elevation 145.9° and lateral elevation 136.6°. A significantly lower mean value of external rotation (39.8°) was found compared to the inner one (50.6°).
 Conclusion: This study confirms those described by other authors promising early results with Delta Xtend RTSA. Longer follow-up is needed with a view to assessment of the dynamics of registered results, possible late complications and revision interventions.

Characterizing moment arms of the coracobrachialis and short head of biceps in native shoulders and after reverse total shoulder arthroplasty during elevation and rotation: a modeling study.

Reverse total shoulder arthroplasty (RTSA) alters the line of action of muscles around the glenohumeral joint. The effects of these changes have been well characterized for the deltoid, but there is limited information regarding the biomechanical changes to the coracobrachialis (CBR) and short head of biceps (SHB). In this biomechanical study, we investigated the changes to the moment arms of the CBR and SHB due to RTSA using a computational model of the shoulder. The Newcastle Shoulder Model, a pre-validated upper-extremity musculoskeletal model, was used for this study. The Newcastle Shoulder Model was modified with bone geometries obtained from 3-dimensional reconstructions of 15 nondiseased shoulders, constituting the native shoulder group. The Delta XTEND prosthesis, with a glenosphere diameter of 38 mm and polyethylene thickness of 6 mm, was virtually implanted in all the models, creating the RTSA group. Moment arms were measured using the tendon excursion method, and muscle length was calculated as the distance between the muscle's origin and insertion points. These values were measured during 0°-150° of abduction, forward flexion, scapular-plane elevation, and -90° to 60° of external rotation-internal rotation with the arm at 20° and 90° of abduction. Statistical comparisons between the native and RTSA groups were analyzed using 1-dimensional statistical parametric mapping (spm1D). Forward flexion moment arms showed the greatest increase between the RTSA group (CBR, 25.3±4.7 mm; SHB, 24.7±4.5 mm) and native group (CBR, 9.6±5.2 mm; SHB, 10.2±5.2 mm). The CBR and SHB were longer in the RTSA group by maximum values of 15% and 7%, respectively. Both muscles had larger abduction moment arms in the RTSA group (CBR, 20.9±4.3 mm; SHB, 21.9±4.3 mm) compared with the native group (CBR, 19.6±6.6 mm; SHB, 20.0±5.7 mm). Abduction moment arms occurred at lower abduction angles in the RTSA group (CBR, 50°; SHB, 45°) than in the native group (CBR, 90°; SHB, 85°). In the RTSA group, both muscles had elevation moment arms until 25° of scapular-plane elevation motion, whereas in the native group, the muscles only had depression moment arms. Both muscles had small rotational moment arms that were significantly different between RTSA and native shoulders during different ranges of motion. Significant increases in elevation moment arms for the CBR and SHB were observed in RTSA shoulders; these increases were most pronounced during abduction and forward elevation motions. RTSA also increased the lengths of these muscles.

Comparative study of 145° onlay curved stem versus 155° inlay straight stem reverse shoulder arthroplasty: clinical and radiographic results with a minimum 2-year follow-up.

Lateralized onlay reverse shoulder arthroplasty (RSA) is designed to ensure better clinical functional recovery and lower rate of complications compared with Grammont medialized inlay RSA. The purpose of the present study was to compare the clinical and radiographic outcomes between these 2 different designs. Eighty-five consecutive patients who underwent RSA were retrospectively analyzed. Nine patients were lost to follow-up, 34 received a curved onlay with a 145° neck-shaft angle (Ascend Flex group), and 42 received a long straight inlay stem with a 155° neck-shaft angle (Delta Xtend group). Patients were reviewed at an average follow-up of 46.8±13.2 months (Ascend Flex group) and 36±10.8 months (Delta Xtend group). Clinical outcome measures included active range of motion, strength, visual analog scale, Constant-Murley score, and the American Shoulder and Elbow Surgeons score. Radiographic evaluation at the final follow-up was performed to assess scapular notching, stress shielding, acromial or scapular fractures, heterotopic ossification, and radiolucent lines or implant loosening. No differences emerged between the 2 groups in terms of visual analog scale, American Shoulder and Elbow Surgeons and Constant-Murley scores, pain, function, strength, mobility, active forward elevation, active internal rotation, active external rotation at 0° and 90° of abduction, abduction, forward elevation, and external rotation strength (P=n.s.). Statistically superior active abduction was observed in the Delta Xtend group (P=.0017). Scapular notching was observed in 12 shoulders (35.2%) in the Ascend Flex group (a grade 1) and in 10 shoulders (23.8%) in the Delta Xtend group (P=n.s.). No differences emerged between the 2 groups in terms of humeral or glenoid radiolucency (P=n.s.). Higher rate of humeral stress shielding rate was observed in the Ascend flex cohort (P=n.s.). No statistically significant difference emerged between the 145° onlay curved stem vs. the 155° inlay straight stem according to most of the evaluated parameters. Statistically superior active abduction was observed in the 155° group although it did not affect patients' satisfaction.

Implant migration and functional outcome of Reverse Shoulder Lateralized Glenosphere Line Extension System: a study protocol for a randomized controlled trial

BackgroundInferior scapular notching is a complication unique to reverse shoulder arthroplasty. The most efficient technique to avoid inferior scapular notching has been reported to be lateralization of the glenoid offset. This study aims to compare radiological and functional outcomes of the DELTA Xtend® Reverse Shoulder System Lateralized Glenosphere Line Extension (intervention group) with the Standard DELTA Xtend® Reverse Shoulder System (control group). We hypothesize that the lateralization improves the patient outcome by decreasing the risk of inferior scapular notching without increasing the risk of migration and loosening of glenoid component.MethodsIn this randomized controlled trial, all Danish citizens with rotator cuff arthropathy or degeneration of the glenohumeral joint with severe posterior wear and allocated for a reverse total shoulder arthroplasty at the department of orthopaedic surgery at Herlev and Gentofte Hospital, Copenhagen University Hospital, will be considered for participation. The exclusion criteria are as follows: below 50 years of age, cognitive or linguistic impairment, insufficient glenoid bone stock, previous fracture in the upper extremity and autoimmune-mediated inflammatory arthritis. There will be included a total of 122 patients of which 56 will participate in the radiostereometric analysis. This number of patients allows 20% to drop out. The co-primary outcomes are the pattern and magnitude of the migration of the glenoid component assessed by radiostereometric analysis and the Western Ontario Osteoarthritis of the Shoulder index. The secondary outcomes are inferior scapular notching, patient-reported and functional outcomes (Oxford shoulder score, Constant-Murley score and pain), side effects and complications, changes in bone mineral density and economy. The included patients will be examined before the surgery, within 1 week and 3, 6, 12 and 24 months after.DiscussionNo previous studies have compared the conventional reverse shoulder arthroplasty with the lateralized reverse shoulder arthroplasty in a randomized controlled trial regarding migration and functional outcome. Furthermore, radiostereometric analysis has not been used to evaluate the migration of reverse shoulder arthroplasty in a randomized controlled trial. This study intends to determine which treatment has the most optimal outcome for the benefit of future patients with an indication for reverse shoulder arthroplasty.Trial registrationThe study has been notified to Pactius and has approval number P-2021-231. Furthermore, the study will be registered on Clinicaltrials.gov before starting the inclusion.

Effect of glenosphere size on reverse shoulder arthroplasty revision rate: an analysis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).

Modularity is an integral element of reverse total shoulder arthroplasty (RTSA). Glenosphere diameter is a key component, but its effect on revision rate is unknown. The aim of this study was to investigate the relationship between glenosphere size and revision rates in RTSA procedures. Data from a large national arthroplasty registry were analyzed for the period April 2004 to 31 December 2019. The study population included all primary RTSA procedures using glenosphere sizes <38 mm, 38-40 mm, and >40 mm. A subanalysis of glenosphere sizes for each of the 3 most commonly implanted prostheses and further analyses by patient age and gender were also performed. The rate of revision was determined by Kaplan-Meier estimates, with comparisons by Cox proportional hazard models. There were 28,817 primary RTSA procedures. Glenosphere sizes <38 mm had a higher revision rate compared to 38-40-mm glenospheres (hazard ratio [HR]1.28, 95% confidence interval [CI] 1.11, 1.48, P<.001) and >40-mm sizes (HR1.35, 95% CI 1.15, 1.59, P<.001). Males with <38-mm and 38-40-mm glenospheres had significantly higher revision rates compared to >40-mm glenospheres (HR1.49, 95% CI 1.21, 1.83, P<.001; and HR1.28, 95% CI 1.03, 1.58, P=.025, respectively). Females with <38-mm and >40-mm glenospheres had higher revision rates compared to females with 38-40-mm glenospheres (HR 1.38, 95% CI 1.14, 1.68, P<.001; and HR 1.41, 95% CI 1.06, 1.88, P=.019, respectively). For patients aged 65-74 years, glenospheres >40 mm had a significantly lower revision rate than both the <38-mm glenospheres (entire period: HR0.59, 95% CI 0.45, 0.76, P<.001) and 38-40-mm glenospheres (entire period: HR0.72, 95% CI 0.54, 0.94, P=.017). For patients aged ≥75 years (n=14,622), <38-mm glenospheres had a significantly higher rate of revision compared with 38-40-mm glenospheres after 3 months (HR1.43, 95% CI 1.09, 1.86, P=.009). Analysis comparing glenosphere sizes within each of the 3 most commonly implanted prostheses found that the Delta Xtend with 38-40-mm glenospheres had higher revision rates compared with >40-mm glenospheres (HR1.49, 95% CI 1.14, 1.92, P=.003). The SMR L1 (Lima) 38-40-mm glenospheres had a lower rate of revision compared with the <38-mm (HR0.50, 95% CI 0.37, 0.67, P<.001) and >40-mm glenospheres (HR0.60, 95% CI 0.43, 0.85, P=.004). Glenospheres <38 mm can be expected to increase revision rates in primary RTSAs. The optimum size of glenospheres is gender, age, and prosthesis specific, with revision rates lower for females with 38-40-mm glenospheres and lower for males with >40-mm glenospheres.

Elongation of the brachial plexus after reverse shoulder arthroplasty: an anatomical study.

The use of reverse shoulder arthroplasty (RSA) is becoming more extended and its clinical results are good or excellent according to the literature. The main biomechanical characteristic of RSA is that it lowers and medializes the centre of rotation of the shoulder causing an arm lengthening. Although the number of neurological complications is low (5%), there are more neurophysiological changes in the brachial plexus with RSA than with the anatomic shoulder arthroplasty. The main goal of this study was to quantify the lengthening of the terminal branches of the brachial plexus suffered after RSA implantation. 20 Embalmed cadavers were analysed. Four distances using bone references were employed to measure the lengthening of the arm and subacromial space. The brachial plexus and its terminal branches (radial, axillary, ulnar, musculocutaneous and median nerves) and the axillary artery, were identified and marked. Measurements were made to determine the change of position of the neurovascular structures, the arm lengthening and the lengthening of each nerve before and after the implantation of RSA. Two models of RSA were used: SMR®(Lima) and Delta Xtend®(DePuy-Synthes). The mean arm elongation was 10.5mm. The subacromial space suffers an elongation of 20.5-29.8%. All the neurovascular structures suffered elongation: median nerve 23.1%, musculocutaneous nerve 22.1%, ulnar nerve 19%, radial nerve 17%, axillary nerve 12-14.5%, axillary artery 24.8%. There were no differences in the results between the types of prosthesis. Due to its design, the RSA causes an arm lengthening which is reflected by the elongation of the neurovascular structures of the arm.

Dislocation after reverse total shoulder arthroplasty using contemporary medialized modular systems. Can we still consider it such a frequent complication?

Improvement in reverse total shoulder arthroplasty (RTSA) prosthesis and technique has reduced the initially high complication and revision rates associated with this implant. However, instability continues to be a leading cause of reoperation after RTSA, being related in previous studies with medialized designs. The aim of this study was to determine the dislocation rate with the employment of two medialized modular systems of RTSA in our institution. A retrospective review of two different modular systems of RTSA (SMR Modular Shoulder System and Delta XTEND Reverse Shoulder) was performed between 2009 and 2017 with a minimum 3-year follow-up. Baseline demographic, clinical (Constant, ASES and ROM), and radiographic data were collected. Characteristics of postoperative instability cases were also evaluated. 237 primary RTSA (41% SMR/59% Delta) and 34 revision RTSA (44% SMR/56% Delta) with a mean follow-up of 75.6 ± 5.2months (79.2 SMR/86.3 Delta, p = .586) were included in the present study. Indications for primary RTSA were osteoarthritis, rotator cuff tear arthropathy and massive irreparable rotator cuff tear (64%), acute fracture (32%), and fracture sequelae (4%). Subscapularis tendon was always repaired in degenerative pathology and tuberosities reattached in traumatic cases. The mean age of the global series was 76.5 ± 5.3years (75.8 SMR/78.6 Delta, p = .104) with a mean Constant/ASES score at final follow-up of 68.5 ± 4.3/72.9 ± 20.3 (71/68 SMR and 69/74 Delta, p = .653 and .642). Only 2 patients (one acute fracture and one fracture sequelae) suffered an early postoperative anterior dislocation (before 3months) which represents a rate of .84% in primary cases and .73% including revision surgery. Closed reduction manoeuvres were not successful, and both patients required revision surgery. At the end follow-up, both were stable and had no further dislocations. The dislocation rate after RTSA with the employment of two contemporary modular systems with a medialized centre of rotation is extremely low, especially when compared with the previously published series with the original Grammont design. Acute fracture and fracture sequelae were the main diagnoses associated with this instability. The reasons for the low dislocation rate are multifactorial, but the improvement in the baseplate position according to the more recent standards of "ideal position" and technical aspects such as subscapularis repair or tuberosity reattachment in fractures probably play an important role in this aspect.

Primary stability of fixation methods for periprosthetic fractures of the humerus: a biomechanical investigation.

The incidence of periprosthetic fractures of the proximal humerus is gradually increasing, following an increase in reverse shoulder arthroplasties in recent years. Locking plate fixation and revision arthroplasty are both valuable treatment methods. However, the primary stability of fixation methods for periprosthetic fractures has not been investigated in detail. The aim of this study was to analyze and compare the primary stability of the common treatment measures. Cemented reverse total shoulder arthroplasty (Delta Xtend; DePuy Synthes, Warsaw, IN, USA) was performed in 5 shoulders, and a distal, mid-diaphysis humeral fracture (Wright and Cofield type B) was induced. The implant was left in place, and 3 distinct fixation scenarios were tested: osteosynthesis using 4.5-mm locking plate fixation (subgroup A), 4.5-mm locking plate fixation with an additional 3.5-mm locking plate (subgroup B), and 4.5-mm locking plate fixation with an additional K-wire cerclage (subgroup C). The specimens were tested in a biomechanical setup simulating activities of daily living including rotation. Strain gauges (4-wire strain at 120 Ω; Vishay Measurements Group, Chartres, France) mounted on the 4.5-mm locking plates were used to evaluate the strain of the fixation and to give an estimate of primary stability. Regarding the simulation of activities of daily living, no statistically significant differences were found in the measured strains on the locking plate between subgroups A, B, and C. A maximum measured strain of 216.85 μm/m in subgroup A resulted in bending of the locking plate (length, 134 mm) of 0.03 mm. In subgroup B (277.01 μm/m), the plate strained 0.04 mm compared with a strain measurement of 0.01 mm in subgroup C (75.93 μm/m). Additional K-wire cerclages or additional 3.5-mm locked plating did not increase primary stability. With a stable prosthetic implant in place, 4.5-mm locked plating is sufficient to address periprosthetic humeral shaft fractures in the present invitro setup.

Low risk of revision after reverse shoulder arthroplasty for acute proximal humeral fractures

BackgroundReverse shoulder arthroplasty (RSA) has gained popularity in the treatment of proximal humeral fractures (PHFs), especially in elderly patients. The purpose of this study was to investigate the use of RSA implants for acute PHFs and risk of revision, as well as risk factors for revision.MethodsRSA implants for acute PHFs were identified from the Nordic Arthroplasty Register Association registry data from 2004 to 2016. Kaplan-Meier survival analysis was used to calculate implant survival. Cox multiple regression analysis was used to calculate the adjusted revision rate for sex, age, country of operation, and year of surgery.ResultsThe study included 1523 RSA implants for PHFs (84% women; average age, 77 years; average follow-up time, 2.5 years). The 5-year cumulative implant survival rate was 97% (confidence limits, 95.5% and 98%). Revision was performed for 33 implants (2%). The most common reason for revision was instability, occurring in 11 cases (0.7%), followed by fracture, occurring in 6 (0.4%), and infection, occurring in 5 (0.3%). Four different arthroplasty brands were used in this cohort, with the Delta Xtend in two-thirds of cases (n = 1025). Age younger than 60 years and male sex were associated with slightly higher rates of revision; however, these differences did not reach statistical significance (hazard ratio of 2.02 with P = .075 and hazard ratio of 3.23 with P = .057, respectively).ConclusionThe use of RSA for acute PHFs is increasing in the Nordic countries. The short-term risk of revision is low. The main reason for revision of RSA for this indication is instability.

What Factors are Associated with Revision or Worse Patient-reported Outcome after Reverse Shoulder Arthroplasty for Cuff-tear Arthropathy? A Study from the Danish Shoulder Arthroplasty Registry.

Reverse shoulder arthroplasty has been proven to improve function in shoulders with cuff-tear arthropathy, but existing studies are primarily single-center studies with a small number of patients, which limits their ability to identify patients who have an increased risk of revision or a worse functional outcome. (1) What is the estimated 10-year cumulative revision rate after reverse shoulder arthroplasty for cuff-tear arthropathy, and what factors are associated with the risk of revision? (2) What is the patient-reported outcome 1 year after surgery, and what factors are associated with a worse patient-reported outcome? We included all patients treated with reverse shoulder arthroplasty for cuff-tear arthropathy reported in the Danish Shoulder Arthroplasty Registry from 2006 to 2015. During the study period, the completeness of reporting was 93% for both primary and revision arthroplasties. Estimated revision rates were illustrated using the Kaplan-Meier method, and hazard ratios were calculated using a Cox regression model. Patient-reported outcome was measured with a postal survey at 12 months (range 10-14 months) postoperatively using the Western Ontario Osteoarthritis of the Shoulder (WOOS) index. The WOOS is a patient-administered questionnaire that measures the quality of life of patients with glenohumeral osteoarthritis. A visual analog scale that ranges from 0 to 100 is used for each question. There are 19 questions, giving a total score ranging from 0 to 1900, with 1900 being the worst. For simplicity of presentation, raw scores were converted to a percentage of the maximum score, with 100 being the best. There is no defined minimal clinically important difference of the WOOS, but the Danish Shoulder arthroplasty registry has for many years regarded an arbitrary difference of 10 or above as being clinically relevant. The rate of response to the WOOS was 71%. The estimated 10-year cumulative revision rate was 8.5% (95% confidence interval, 5.7%-11.3%) with differences between the arthroplasty model (21.0%; 95% CI, 11.8% to 30.8% for the Delta Mark III and 5.5%; 95% CI, 3.7% to 7.3% for the Delta Xtend) and gender (6.0%; 95% CI, 3.0% to 9.0% for women and 13.1%; 95% CI, 7.1% to 19.1% for men). After controlling for potential confounding variables including gender, previous surgery, arthroplasty model, and period of surgery, the risk of revision was higher with the Delta Mark III than with the Delta Xtend (hazard ratio 2.7; 95% CI, 1.3 to 5.4; p < 0.01) and higher in men than in women (hazard ratio 2.7; 95% CI, 1.6 to 4.7; p < 0.01). Thirty-three percent (19 of 57) of the revision arthroplasties were performed for dislocation and 32% (18 of 57) were to treat periprosthetic joint infection. After controlling for confounding variables, only previous surgery was associated with a worse WOOS score (mean difference -10.6; 95% CI, -15.2 to -5.9; p < 0.01); there were no associations between a worse score and gender, arthroplasty model, age group, or period of surgery. The results from the present study can be used to inform patients about their individual risk of revision or a disappointing functional outcome. The study also demonstrates the need for proper patient selection and attention to technical details to reduce the risk of revision, especially for men. Our follow-up time was, however, short, with only an estimate of the 10-year revision rate. Future studies with a long-term follow-up duration are needed to confirm our results. Level III, therapeutic study.

Short-Term Outcomes of the Grammont Reverse Shoulder Arthroplasty: Comparison between First and Second Generation Delta Prosthesis.

Purpose This article compares short-term outcomes of two series of patients, who underwent reverse total shoulder arthroplasty (RTSA) with two different implants, both based on Grammont's principles: the Delta III (D-3) and the Delta Xtend (D-XT) prostheses. Methods The D-3 group included a consecutive series of 26 patients (mean age 75 years), that were treated between 2000 and 2006; the D-XT group included a consecutive series of 31 patients (mean age 72.5 years), for a total of 33 implants performed between 2011 and 2015. In both groups the most common diagnoses were cuff tear arthropathy (18 and 22 shoulders, respectively) and malunion of proximal humerus fractures (3 and 5). All procedures were performed by the same surgeon. Constant–Murley score (CMS) was used to assess clinical and functional outcomes. Radiographic evaluation included the true anteroposterior and axillary views. Results Twenty-three patients of the D-3 group and 22 patients (24 shoulders) of the D-XT group were evaluated at a mean follow-up of 42 months (range 26–84) and 44 months (range 26–66), respectively. Four complications occurred in the D-3 group (1 partial deltoid detachment, 1 dislocation, and 2 glenoid component loosening), while one early postoperative infection occurred in the D-XT group. Increases in elevation and CMS between preoperative and postoperative period were observed in both groups; only the D-XT group showed a slight improvement in rotations. The incidence of scapular notching was significantly different between the two groups: 100% for D-3 and 22.2% for D-XT in patients with a minimum follow-up of 5 years. Conclusion Prosthetic design evolution and greater acquaintance with this surgery have undoubtedly led to an improvement in short-term outcomes with second generation implants of RTSA. Future studies will have to ascertain whether newer implants, relying on biomechanical solutions alternative to Grammont's original concept, might provide additional advantages and minimize drawbacks.

Safety and Effectiveness of Shoulder Arthroplasties in Spain: A Systematic Review

The effectiveness and safety of shoulder arthroplasties in the general context of a Spanish patient population remains unclear. The aim of this study was to ascertain both the effectiveness and safety of primary shoulder arthroplasties and the prosthesis types used in Spain. A systematic review of all the available literature evaluating the effectiveness and safety of primary shoulder arthroplasties in Spain was performed. A narrative synthesis was performed, and evidence tables were created in four dimensions: study design, arthroplasty characteristics, safety, and effectiveness. Orthopaedic Data Evaluation Panel (ODEP) scores were used to evaluate prosthesis types. Twenty-one studies were selected that included a total of 1293 arthroplasties. The most common indication was fractures, while the prosthesis most frequently used was the Delta Xtend (ODEP 10A). The most common complication was scapular notching. Prosthesis revision rate was approximately 6% for follow-ups between 12 and 79 months. In addition, significant improvements were observed in the Constant–Murley test score after the intervention. Currently in Spain, shoulder arthroplasty can be considered a safe and effective procedure with functional recovery and pain reduction for eligible patients with humeral fracture, rotator cuff arthropathy, fracture sequelae and malunion of the proximal humerus, and degenerative disease. Future longitudinal research and population-based studies could serve to confirm these results and identify points of improvement.

La cimentation des vis de fixation de l’implant glénoïdien dans les prothèses inversées n’améliore pas la fixation primaire : une étude cadavérique

IntroductionCuff tear arthritis and complex proximal humeral fractures are common pathologies that are frequently addressed by the implantation of a reversed shoulder prosthesis. The present cadaveric study aimed to analyze the effect of cement augmentation of the glenoid component on the primary stability in geriatric patients. HypothesisCement augmentation of glenoid baseplate screws has an influence on primary stability in reversed shoulder arthroplasty (RSA). Materials and methodsGlenoid base plates (Delta Xtend, DePuy Synthes, Westchester, USA) were implanted in 6 pairs of formalin-fixated scapulae of 4 female and 2 male donors (average age 83 years). Two angle stable screws were placed at the superior and inferior position. Cement augmentation was performed with 2ml bone cement (Kyphon, Medtronic, Minneapolis, USA) per screw in right specimens. Afterwards, biomechanical testing with 600 to 1000N (100 cycles) at a 65° abduction angle was performed. Finally, a load-to-failure analysis was conducted. ResultsNo implant loosening was observed during cyclic tests from 600N to 1000N. In addition no difference in the plastic deformation was detected at 600N (p=0.301), 700N (p=0.522), 800N (p=0.480), 900N (p=0.521) and 1000N (p=0.748). Load- to- failure analyses revealed implant loosening at 3314N (SD 823N) in the cement-augmented implants and at 3059N (SD 974N) in scapulae with non-cemented screws (p=0.522). DiscussionCement- augmented fixation of the glenoid component did not result in an increased primary stability in this study. Thus, the application of cement should be critically assessed considering associated risks and increased costs. Level of proofBasic science study, Controlled laboratory study.

Delta Xtend reverse shoulder arthroplasty - Results at a minimum of five years.

Reverse shoulder arthroplasty provides predictable pain relief and improvements in function, but concerns remain regarding complication rates and there is little long-term outcome data. The aim of this study was to review the clinical and radiographic outcomes of the Delta Xtend reverse shoulder arthroplasty at a minimum of five years. Ninety-six Delta Xtend reverse shoulder arthroplasty procedures were performed in 93 patients. There were 41 males and 52 females with an average age of 74.9 years. All available patients returned for clinical and radiographic analysis, including completion of patient reported outcome measures. The complication rate was 9.4%. There were three revisions (3.1%) and two other reoperations (2.1%). Fifty-nine shoulders were available for review at an average of 81 months. Average forward flexion was 142°. Average American Shoulder and Elbow Assessment Score improved from 27.6 to 78.5 (p<0.001). Radiolucent lines and/or proximal bone resorption was seen in 35.4%. Scapula notching was observed in 69.1%, with Grade III or IV notching in 20%. These findings had no effect on patient reported outcome measures. This study confirms the clinical benefits of reverse shoulder arthroplasty, with improvements maintained out to 10 years. The high rate of scapula notching remains a concern. Further study is needed to fully understand the clinical significance of notching, as well as the potential benefits of newer implant designs.

Long-term results of the Delta Xtend reverse shoulder prosthesis

Reverse shoulder arthroplasty has become the standard treatment for cuff tear arthropathy and complex fractures of the proximal humerus. The Delta Xtend prosthesis (DePuy Synthes, Warsaw, IN, USA) was launched in 2006 and has shown good short-term results. Longer-term results are not yet available. There were 126 primary Delta Xtend prostheses implanted in our center by 1 surgeon from October 2006 until December 2009. Of these, 38 patients died, 12 were lost to follow-up, and 2 needed early revision of the prosthesis. Follow-up of at least 8 years was available for 74 patients. At preoperative and postoperative visits, shoulder function and pain were evaluated using the age- and sex-adjusted Constant-Murley score (aCS). The satisfaction rate was evaluated on a visual analog scale (VAS). The mean follow-up in our population was 113.1 months. The mean aCS was 44.6% (standard deviation [SD], 19.2) preoperatively. It increased significantly (P < .001) after surgery to 75.8% (SD, 12.5) at 3 months and 91.1% (SD, 11.8) at 5 years. At the latest follow-up, the mean aCS was only 79.9% (SD, 17.7), which was significantly lower (P = .002) than the aCS at 5 years postoperatively. An overall survival rate of more than 97% was seen at 8 years of follow-up. This study confirms that the promising short-term results of the Delta Xtend prosthesis can be extended in the longer-term. However, further follow-up will be necessary to check whether the statistically significant decrease in the Constant-Murley score at latest follow-up, which was driven by a decrease in range of motion and power, continues or not.