- Email: [email protected]
The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review
J Shoulder Elbow Surg (2015) 24, 988-993
www.elsevier.com/locate/ymse
The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review Brandon J. Erickson, MDa,*, Rachel M. Frank, MDa, Joshua D. Harris, MDb,c, Nathan Mall, MDd, Anthony A. Romeo, MDa a
Division of Orthopaedic Surgery, Midwest Orthopaedics at Rush, Rush University Medical Center, Chicago, IL, USA Department of Orthopedics and Sports Medicine, Houston Methodist Hospital, Houston, TX, USA c Division of Orthopaedic Surgery, Clinical Orthopaedic Surgery, Weill Cornell College of Medicine, New York, NY, USA d Division of Orthopaedic Surgery, Regeneration Orthopedics, Cartilage Restoration Center of St. Louis, St. Louis, MO, USA b
Background: Humeral component inclination may play an important role in implant stability and the incidence of scapular notching in reverse total shoulder arthroplasty (RTSA). This study was conducted to determine if a difference exists between RTSA prostheses with a 135 vs 155 humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135 inclination design and that the rate of scapular notching would be significantly higher with the 155 inclination design. Methods: A systematic review was registered with PROSPERO and performed with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting the number of dislocations, number of patients with scapular notching, and postoperative range of motion after RTSA with levels of evidence I to IV were eligible for inclusion. All study and subject demographics were analyzed. Statistics were calculated using 2-proportion z tests. Results: Thirty-eight studies including 2222 shoulders (average age, 70.3 3.91 years; 67% female) undergoing RTSA were included. Of these, 1762 (79.3%) used the 155 inclination prosthesis and 460 (20.7%) used the 135 inclination prosthesis with a lateralized glenosphere. The rate of scapular notching was 2.83% in the 135 group and 16.80% in the 155 group (P < .0001, z ¼ 7.7107). The rate of dislocation was 1.74% in the 135 group and 2.33% in the 155 group (P ¼ .4432, z ¼ 0.7669). Conclusions: Our systematic review of 38 studies and 2222 shoulders found that the rate of scapular nothing was significantly higher with the 155 prosthesis than with the 135 prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses. Level of evidence: Level IV, Systematic Review. Ó 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Reverse total shoulder arthroplasty; rotator cuff arthropathy; head neck angle; scapular notch; dislocation
Institutional Review Board approval was not required for this study. *Reprint requests: Brandon J. Erickson, MD, Midwest Orthopaedics at Rush, Rush University Medical Center, 1611 W Harrison St, Ste 300, Chicago, IL 60612, USA.
E-mail address: [email protected] (B.J. Erickson).
1058-2746/$ - see front matter Ó 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2015.01.001
Reverse TSA scapular notching and dislocation Reverse total shoulder arthroplasty (RTSA), first described in the 1970’s by Neer, is a well-accepted treatment for symptomatic rotator cuff tear arthropathy in patients with pseudoparalysis and a functional deltoid.7,9 Since the inception of the reversed prosthesis, there have been several design permutations, including changes in humeral head inclination, an increase in the size of the glenosphere, and the medialization of the center of rotation of the humeral head.7 The medialization concept was introduced by Paul Grammont in the 1980s as a way to decrease shear forces at the glenosphere and increase the deltoid lever arm in patients with rotator cuff deficiency.1,7 By moving the center of rotation medially and inferiorly, the Grammont style prostheses increased the number of deltoid fibers available for abduction and forward elevation, increased the deltoid’s efficiency by elongating the deltoid muscle, but weakened the teres minor and posterior deltoid for external rotation.13 Medialization of the center of rotation was accompanied by the radiographic finding of scapular notching. In scapular notching, erosion of the glenoid neck occurs secondary to abutment of the humeral polyethylene inferiorly on the scapular neck in arm adduction.13 This finding is typically seen on anteroposterior radiographs of the shoulder. Currently, there is debate about the clinical significance of this finding. Some authors believe it to be a complication that can lead to osteolysis, chronic inflammation, and ultimately, implant loosening.19 Others contest that it is an incidental finding that does not affect clinical outcomes and occasionally represents osteophyte formation rather than true erosion.10,14,23,25 To address scapular notching, the neck-shaft angle of some prostheses was reduced from 155 to 135 ; however, this alteration raised concern over stability. One biomechanical study showed this reduction in inclination did appear to resolve the issue of scapular notching but at the cost of shoulder stability, specifically at 30 of internal rotation.15 However, the 155 configuration was less stable in 30 of external rotation compared with the 135 prosthesis. This study also demonstrated decreasing the neckshaft angle did not significantly lateralize the center of rotation. Thus, the influence of neck shaft angle on stability and scapular notching is still being actively debated. The purpose of this study was to determine if a difference exists between RTSA prostheses with a 135 vs 155 humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135 inclination design and that the rate of scapular notching would be significantly higher with the 155 inclination design.
Methods A systematic review was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses
989 (PRISMA) guidelines using a PRISMA checklist.11 Systematic review registration was performed using the PROSPERO International prospective register of systematic reviews (registration number CRD42014012902, dated July 26, 2014).22 Two reviewers independently conducted the search on March 25, 2014, using the Medline, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. The electronic search citation algorithm used was reverse (title/abstract) and shoulder (title/abstract) and arthroplasty (title/abstract) not arthroscopic (title/abstract)not cadaver (title/abstract) not biomechanical (title/abstract). Level I to IV evidence (2011 update by the Oxford Centre for Evidence-Based Medicine21) clinical studies reported in the English language were eligible. References within included studies were cross-referenced for inclusion if missed by the initial search. If a duplicate population was detected, the study with the greater number of patients or the longer duration follow-up was used and the other excluded. Excluded from this review were level V evidence reviews, medical conference abstracts, letters to the editor, cadaveric studies, basic science, biomechanical studies, arthroscopic shoulder surgery, imaging, surgical technique, and classification studies. Patients of interest in this systematic review underwent RTSA for one of many indications, including rotator cuff tear arthropathy, rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, instability, osteonecrosis, pseudoparalysis, bone tumors, locked shoulder dislocation, acute proximal humeral fractures (2-, 3-, and 4-part), and revision from previously failed total shoulder arthroplasty (TSA), open reduction internal fixation, closed reduction percutaneous pinning, or hemiarthroplasty. A minimum of 24 months of clinical follow-up was required, but there was no minimum rehabilitation requirement. Studies that included patients aged <50 years were excluded. Study and subject demographic parameters analyzed included year of publication, years of patient enrollment, presence of study financial conflict of interest, number of shoulders, preoperative and postoperative range of motion (ROM), prosthesis used, and head-neck angle of the prosthesis. Number of dislocations, number of patients with scapular notching, and ROM (when reported) were recorded for all studies. Study methodologic quality was evaluated using the Modified Coleman Methodology Score.4
Statistical analysis Study descriptive statistics were calculated. Continuous variable data are reported as mean standard deviation from the mean. Weighted means and standard deviations were calculated for all patient and demographic parameters. Categoric variable data are reported as frequency with percentages. P < .05 was considered statistically significant for all statistical analysis measured and calculated from study data extraction or directly reported from the individual studies. A two-proportion z test with equal variance and a ¼ 0.05 was used to compare (1) the proportion of shoulders that had undergone RTSA with a subsequent instability event with 135 or 155 inclinations, and (2) the proportion of shoulders that had undergone RTSA with subsequent scapular notching with 135 or 155 inclinations. The z value scores and P values were calculated using a free publicly available calculator (http://insilico.net/tools/statistics/ztest/).
990
B.J. Erickson et al.
Figure 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart. RTSA, reverse total shoulder arthroplasty; TSA, total shoulder arthroplasty.
Results After implementation of the inclusion criteria, 38 studies published between 2006 and 2014 were available for analysis (Fig. 1). Included were 2222 shoulders undergoing RTSA. The 155 inclination prosthesis was used in 1762 (79.3%) and the 135 inclination prosthesis with a lateralized glenosphere was used in 460 (20.7%). The included patients (67% female) were a mean age of 70.3 3.9 years (range, 50-97 years). Average follow-up for the 135 group and the 155 group combined was 37.9 12.2 months (range, 24-78 months) and was 34.61 9.69 months for the 135 group and 38.32 12.62 months 155 group.
A conflict of interest was present in 13 studies (34.2%), absent in 15 (39.5%) studies, and was not reported in 10 studies (26.3%). The average level of evidence of the included studies was 3.7 0.7 (30 studies were level IV evidence, 5 were level III, and 4 were level II). The country with the most studies included in this review was the United States of America (12 studies), followed by France (7 studies). The rate of scapular notching was 2.83% in the 135 group and 16.80% in the 155 group. Significantly more notching was seen in the 155 group (P < .0001; z ¼ 7.7107). The prostheses mentioned in the 135 group all used a lateralized glenosphere. The rate of dislocation
Reverse TSA scapular notching and dislocation
991
Table I Range of motion differences between 135 and 155 prosthesis in external rotation, forward elevation, and abduction Variable) Pre Post P 135 Pre vs post External rotationy Forward elevation Abduction 155 Pre vs post External rotationy Forward elevation Abduction
135 16.1 59.8 56.5 155 13.7 59.1 50.7 Post
7.34 9.28 9.68 5.62 20.2 18.7
135 32.9 119 115 155 23 125.5 105.7
11.3 12.7 9.42
<.0001z <.0001z N/A
88.9 <.0001z 19.13 <.0001z 14.38 N/A
Post
135 155 135 vs 155 External rotationy 32.9 11.3 23 88.9 .0007z Forward elevation 119 12.7 125.5 19.13 .2265 Abduction 115 9.42 105.7 14.38 N/A N/A, not applicable. ) Data are shown as mean standard deviation. y External rotation with the arm at the side. z Statistically significant.
was 1.74% in the 135 group and 2.33% in the 155 group. The difference in the number of dislocations between the 2 groups was not significant (P < .4432; z ¼ –0.7669). The preoperative and postoperative ROM for the 135 the 155 groups are reported in Table I. The 135 prosthesis and the 155 prosthesis both showed significant improvement in forward elevation and external rotation with the arm at the side from preoperatively to postoperatively. The 135 group demonstrated significantly more postoperative external rotation than the 155 group, but the groups did not differ in forward elevation. There was a trend towards more abduction in the 135 group, but statistical analysis could not be performed because too few studies reported this ROM parameter.
Discussion RTSA is a well-described treatment for patients with rotator cuff arthropathy and for several other shoulder pathologies with a deficient rotator cuff.13 We hypothesized that there would be significantly more scapular notching in the 155 group and significantly more dislocations in the 135 group. The primary findings of this study were that rates of scapular notching were higher in the 155 humeral inclination prosthesis than in the 135 humeral inclination prosthesis (Fig. 2), but the dislocation rates were similar. These results confirmed the first hypothesis because significantly more notching occurred in the 155 group, but the second hypothesis was rejected because the rate of dislocation between the 155 and 135 group was not significantly different. The available data on scapular notching and its effect on clinical outcomes are extremely variable, and the clinical
relevance of radiographic scapular notching has not been completely elucidated. The 155 prosthesis is certainly the most widely accepted inclination angle and has been essentially the only prosthesis used in Europe for more than 10 years.5,12,16-18,20,26,28 An inclination of 155 is theorized to improve joint stability, and further, functionally lengthens the deltoid, improving one’s ability to perform forward elevation-based tasks without an intact rotator cuff.6 However, this inclination is associated with a higher rate of scapular notching, which may be associated with midterm to long-term prosthesis failure.8 Boileau et al2 attempted to decrease the rate of scapular notching in patients with a 155 prosthesis by lateralizing the glenoid using cancellous humeral head autograft. The study concluded that the rate of notching decreased (reported in the study at 19%) with bony lateralization without increasing torque on the glenoid component as is seen metallic lateralization. Our review found the scapular notching rate was 16.8% in the 155 prosthesis group, so whether this bony lateralization did decrease the rate of scapular notching is unclear. Further studies comparing patients with and without bony glenoid lateralization are necessary to evaluate the effectiveness of bony lateralization in decreasing scapular notching with a 155 prosthesis. Furthermore, an eccentric glenosphere in a 155 prosthesis may lead to a decrease in scapular notching rates, as demonstrated by De Biase et al,5 but this needs to be studied in a larger patient cohort to determine if the results are reproducible. The 155 prosthesis does not help with the inherent rotation problems associated with RTSA. In contrast, the 135 prosthesis is more anatomic and is associated with a lower rate of scapular notching.3 With this anatomy, the 135 prosthesis may improve internal and external rotation of the joint, although given the sharper angle, the deltoid is not lengthened as it is with the 155 prosthesis. Thus, the 135 prosthesis may not be associated with improvements in forward elevation strength. Critics of the 135 prosthesis have expressed concern regarding a potential for increased joint instability over time, but the results from this review showed no difference in dislocation events in the 155 prosthesis compared with the 135 prosthesis. Table I reports the differences in ROM with the 155 and 135 prostheses, demonstrating significantly less external rotation, with no significant difference in forward elevation, with the 155 compared with the 135 prosthesis. Although the incidence of notching has been reported at between 44% and 96%, substantial variability exists in the results of patients with and without a notch.20,27 Torrens et al23 examined 36 patients with and without a scapular notch at a minimum of 2 years after an RTSA. The difference in Constant or EQ-5D scores between patients with and without a notch was not significant. However, Levigne et al10 monitored 448 patients for a mean of 51 months after implantation of a Grammont style RTSA to determine if patients who developed a scapular notch had inferior
992
B.J. Erickson et al.
Figure 2
Illustration demonstrates the difference between the (Left) 155 and (Right) 135 prosthesis.
clinical outcomes. Overall, they found 68% of patients developed a scapular notch, and those patients who were more active had an increased likelihood of developing a notch earlier in the postoperative period. Patients who had a notch had slightly decreased passive and active anterior elevation as well as a slight decrease (0.5 kg) in strength, but pain and Constant scores were similar to those in patients without a notch.10 From these studies, scapular notching does not appear to cause a clinically significant deficit. A recent biomechanical study by Oh et al15 demonstrated that the 135 prosthesis was less stable to anterior dislocation forces at 30 of internal rotation compared with the 155 prosthesis but that the 135 prosthesis was more stable than the 155 prosthesis in 30 of external rotation. The authors also found that the 155 prosthesis had an adduction impingement angle of 0 , whereas the 135 prosthesis did not impinge until an average of 12 of adduction. The significance of this is that the 155 prosthesis will notch when the arm is resting at the side and not adducted across the body, whereas the 135 prosthesis will not notch until the arm has been adducted across the body. Our study concluded that the 155 prosthesis had a higher rate of scapular notching, as would be expected from the results of the biomechanical study by Oh et al.15 As the study by Oh et al pointed out, the 155 prosthesis was more stable in internal rotation but not as stable in external rotation as the 135 prosthesis, possibly accounting for this lack of difference. In addition to (or instead of) reducing the amount of inclination, other design features, such as the amount of lateral glenoid offset, have been adjusted to decrease the incidence of scapular notching. For example, lateralizing the
glenosphere center of rotation to increase lateral glenoid offset, by using a bone graft (Bio-RSA; Tornier, Saint-Ismier, France) or a lateral offset built into the implant itself (Reverse Shoulder Prosthesis; DJO Surgical, Austin, TX, USA), has been shown to reduce notching.3 Whether increasing the amount of lateral glenoid offset is as effective at decreasing scapular notching compared with decreasing the inclination angle of the humeral component remains unclear. Although the results of this study demonstrate an increased rate of notching in the 155 group, these data must be scrutinized. Valenti et al24 reported a RTSA prosthesis with a less medialized design (more lateral center of rotation) to attempt to correct the problem of scapular notching. The study found no glenoid notching or loosening in 76 patients at an average of 44 months of follow-up. Most of the 135 prostheses included in this study were combined with a lateralized glenosphere, making it difficult to confirm whether the results of this study were solely related to inclination angle of the humeral component. Lastly, there was a significant difference in the postoperative external rotation in the 135 group compared with the 155 group but not a significant difference in forward elevation, although there was a trend toward more forward elevation in the 155 group. The external rotation was statistically significant, but this difference may not correlate with any clinical differences. This study has several limitations. Although 2 authors performed the search, some studies could have been missed, possibly introducing selection bias. Several studies were excluded because there was no mention of the prosthesis that was used. Several studies did not report all of the variables the authors examined, including ROM, leading to inclusion bias.
Reverse TSA scapular notching and dislocation Owing to inconsistent reporting of outcomes by the individual studies included in this review, this study did not address outcome measures and so cannot draw conclusions on the best implant choice or effects of the head-neck angle on objective outcome scores. This study also did not examine any concomitant pathology at the time of surgery, nor did it look at postoperative complications other than those listed in the study. Finally, the clinical relevance of scapular notching cannot be determined by this study.
Conclusions Our systematic review of 38 studies comprising 2222 shoulders found that the 155 prosthesis has a significantly higher rate of scapular notching compared with the 135 prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses.
References 1. Baulot E, Sirveaux F, Boileau P. Grammont’s idea: the story of Paul Grammont’s functional surgery concept and the development of the reverse principle. Clin Orthop Relat Res 2011;469:2425-31. http://dx. doi.org/10.1007/s11999-010-1757-y 2. Boileau P, Moineau G, Roussanne Y, O’Shea K. Bony increased-offset reversed shoulder arthroplasty: minimizing scapular impingement while maximizing glenoid fixation. Clin Orthop Relat Res 2011;469: 2558-67. http://dx.doi.org/10.1007/s11999-011-1775-4 3. Clark JC, Ritchie J, Song FS, Kissenberth MJ, Tolan SJ, Hart ND, et al. Complication rates, dislocation, pain, and postoperative range of motion after reverse shoulder arthroplasty in patients with and without repair of the subscapularis. J Shoulder Elbow Surg 2012;21:36-41. http://dx.doi.org/10.1016/j.jse.2011.04.009 4. Cowan J, Lozano-Calderon S, Ring D. Quality of prospective controlled randomized trials. Analysis of trials of treatment for lateral epicondylitis as an example. J Bone Joint Surg Am 2007;89:1693-9. http://dx.doi.org/10.2106/JBJS.F.00858 5. De Biase CF, Delcogliano M, Borroni M, Castagna A. Reverse total shoulder arthroplasty: radiological and clinical result using an eccentric glenosphere. Musculoskelet Surg 2012;96(Suppl 1):S27-34. http://dx.doi.org/10.1007/s12306-012-0193-4 6. Favard L, Levigne C, Nerot C, Gerber C, De Wilde L, Mole D. Reverse prostheses in arthropathies with cuff tear: are survivorship and function maintained over time? Clin Orthop Relat Res 2011;469:246975. http://dx.doi.org/10.1007/s11999-011-1833-y 7. Flatow EL, Harrison AK. A history of reverse total shoulder arthroplasty. Clin Orthop Relat Res 2011;469:2432-9. http://dx.doi.org/10. 1007/s11999-010-1733-6 8. Groh GI, Groh GM. Complications rates, reoperation rates, and the learning curve in reverse shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:388-94. http://dx.doi.org/10.1016/j.jse.2013.06.002 9. Hyun YS, Huri G, Garbis NG, McFarland EG. Uncommon indications for reverse total shoulder arthroplasty. Clin Orthop Surg 2013;5:24355. http://dx.doi.org/10.4055/cios.2013.5.4.243 10. Levigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop Relat Res 2011;469:2512-20. http://dx.doi.org/ 10.1007/s11999-010-1695-8
993 11. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gotzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009;62: e1-34. http://dx.doi.org/10.1016/j.jclinepi.2009.06.006 12. Martinez AA, Bejarano C, Carbonel I, Iglesias D, Gil-Albarova J, Herrera A. The treatment of proximal humerus nonunions in older patients with reverse shoulder arthroplasty. Injury 2012;43(Suppl 2): S3-6. http://dx.doi.org/10.1016/S0020-1383(13)70172-4 13. Nicholson GP, Strauss EJ, Sherman SL. Scapular notching: recognition and strategies to minimize clinical impact. Clin Orthop Relat Res 2011;469:2521-30. http://dx.doi.org/10.1007/s11999-010-1720-y 14. Nyffeler RW, Werner CM, Simmen BR, Gerber C. Analysis of a retrieved Delta III total shoulder prosthesis. J Bone Joint Surg Br 2004;86:1187-91. http://dx.doi.org/10.1302/0301-620X.86B8.15228 15. Oh JH, Shin SJ, McGarry MH, Scott JH, Heckmann N, Lee TQ. Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:1091-8. http://dx.doi.org/10.1016/j.jse.2013.11.003 16. Randelli P, Randelli F, Arrigoni P, Ragone V, D’Ambrosi R, Masuzzo P,, et al. Optimal glenoid component inclination in reverse shoulder arthroplasty. How to improve implant stability. Musculoskelet Surg 2014;98(Suppl):15-8. http://dx.doi.org/10.1007/s12306-014-0324-1 17. Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg 2001;10:17-22. 18. Sayana MK, Kakarala G, Bandi S, Wynn-Jones C. Medium term results of reverse total shoulder replacement in patients with rotator cuff arthropathy. Ir J Med Sci 2009;178:147-50. http://dx.doi.org/10.1007/ s11845-008-0262-8 19. Scarlat MM. Complications with reverse total shoulder arthroplasty and recent evolutions. Int Orthop 2013;37:843-51. http://dx.doi.org/10. 1007/s00264-013-1832-6 20. Simovitch RW, Zumstein MA, Lohri E, Helmy N, Gerber C. Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement. J Bone Joint Surg Am 2007;89: 588-600. http://dx.doi.org/10.2106/JBJS.F.00226 21. The University of Oxford. Centre for Evidence Based Medicine. OCEBM 2011 levels of evidence system. Available at: http://www. cebm.net/index.aspx?o¼5653. Accessed August 1, 2014. 22. The University of York. Centre for Reviews and Dissemination. PROSPERO - International prospective register of systematic reviews. Available at: http://www.crd.york.ac.uk/PROSPERO/. Accessed August 14, 2014. 23. Torrens C, Santana F, Picazo B, Caceres E. Retrospective study of scapular notches in reverse shoulder arthroplasties. Am J Orthop (Belle Mead NJ) 2013;42:362-5. 24. Valenti P, Sauzieres P, Katz D, Kalouche I, Kilinc AS. Do less medialized reverse shoulder prostheses increase motion and reduce notching? Clin Orthop Relat Res 2011;469:2550-7. http://dx.doi.org/ 10.1007/s11999-011-1844-8 25. Vanhove B, Beugnies A. Grammont’s reverse shoulder prosthesis for rotator cuff arthropathy. A retrospective study of 32 cases. Acta Orthop Belg 2004;70:219-25. 26. Wall B, Nove-Josserand L, O’Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85. http://dx.doi.org/10. 2106/JBJS.F.00666 27. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86. http://dx.doi.org/10.2106/JBJS.D. 02342 28. Young AA, Smith MM, Bacle G, Moraga C, Walch G. Early results of reverse shoulder arthroplasty in patients with rheumatoid arthritis. J Bone Joint Surg Am 2011;93:1915-23. http://dx.doi.org/10.2106/JBJS. J.00300
www.elsevier.com/locate/ymse
The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review Brandon J. Erickson, MDa,*, Rachel M. Frank, MDa, Joshua D. Harris, MDb,c, Nathan Mall, MDd, Anthony A. Romeo, MDa a
Division of Orthopaedic Surgery, Midwest Orthopaedics at Rush, Rush University Medical Center, Chicago, IL, USA Department of Orthopedics and Sports Medicine, Houston Methodist Hospital, Houston, TX, USA c Division of Orthopaedic Surgery, Clinical Orthopaedic Surgery, Weill Cornell College of Medicine, New York, NY, USA d Division of Orthopaedic Surgery, Regeneration Orthopedics, Cartilage Restoration Center of St. Louis, St. Louis, MO, USA b
Background: Humeral component inclination may play an important role in implant stability and the incidence of scapular notching in reverse total shoulder arthroplasty (RTSA). This study was conducted to determine if a difference exists between RTSA prostheses with a 135 vs 155 humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135 inclination design and that the rate of scapular notching would be significantly higher with the 155 inclination design. Methods: A systematic review was registered with PROSPERO and performed with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting the number of dislocations, number of patients with scapular notching, and postoperative range of motion after RTSA with levels of evidence I to IV were eligible for inclusion. All study and subject demographics were analyzed. Statistics were calculated using 2-proportion z tests. Results: Thirty-eight studies including 2222 shoulders (average age, 70.3 3.91 years; 67% female) undergoing RTSA were included. Of these, 1762 (79.3%) used the 155 inclination prosthesis and 460 (20.7%) used the 135 inclination prosthesis with a lateralized glenosphere. The rate of scapular notching was 2.83% in the 135 group and 16.80% in the 155 group (P < .0001, z ¼ 7.7107). The rate of dislocation was 1.74% in the 135 group and 2.33% in the 155 group (P ¼ .4432, z ¼ 0.7669). Conclusions: Our systematic review of 38 studies and 2222 shoulders found that the rate of scapular nothing was significantly higher with the 155 prosthesis than with the 135 prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses. Level of evidence: Level IV, Systematic Review. Ó 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Reverse total shoulder arthroplasty; rotator cuff arthropathy; head neck angle; scapular notch; dislocation
Institutional Review Board approval was not required for this study. *Reprint requests: Brandon J. Erickson, MD, Midwest Orthopaedics at Rush, Rush University Medical Center, 1611 W Harrison St, Ste 300, Chicago, IL 60612, USA.
E-mail address: [email protected] (B.J. Erickson).
1058-2746/$ - see front matter Ó 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2015.01.001
Reverse TSA scapular notching and dislocation Reverse total shoulder arthroplasty (RTSA), first described in the 1970’s by Neer, is a well-accepted treatment for symptomatic rotator cuff tear arthropathy in patients with pseudoparalysis and a functional deltoid.7,9 Since the inception of the reversed prosthesis, there have been several design permutations, including changes in humeral head inclination, an increase in the size of the glenosphere, and the medialization of the center of rotation of the humeral head.7 The medialization concept was introduced by Paul Grammont in the 1980s as a way to decrease shear forces at the glenosphere and increase the deltoid lever arm in patients with rotator cuff deficiency.1,7 By moving the center of rotation medially and inferiorly, the Grammont style prostheses increased the number of deltoid fibers available for abduction and forward elevation, increased the deltoid’s efficiency by elongating the deltoid muscle, but weakened the teres minor and posterior deltoid for external rotation.13 Medialization of the center of rotation was accompanied by the radiographic finding of scapular notching. In scapular notching, erosion of the glenoid neck occurs secondary to abutment of the humeral polyethylene inferiorly on the scapular neck in arm adduction.13 This finding is typically seen on anteroposterior radiographs of the shoulder. Currently, there is debate about the clinical significance of this finding. Some authors believe it to be a complication that can lead to osteolysis, chronic inflammation, and ultimately, implant loosening.19 Others contest that it is an incidental finding that does not affect clinical outcomes and occasionally represents osteophyte formation rather than true erosion.10,14,23,25 To address scapular notching, the neck-shaft angle of some prostheses was reduced from 155 to 135 ; however, this alteration raised concern over stability. One biomechanical study showed this reduction in inclination did appear to resolve the issue of scapular notching but at the cost of shoulder stability, specifically at 30 of internal rotation.15 However, the 155 configuration was less stable in 30 of external rotation compared with the 135 prosthesis. This study also demonstrated decreasing the neckshaft angle did not significantly lateralize the center of rotation. Thus, the influence of neck shaft angle on stability and scapular notching is still being actively debated. The purpose of this study was to determine if a difference exists between RTSA prostheses with a 135 vs 155 humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135 inclination design and that the rate of scapular notching would be significantly higher with the 155 inclination design.
Methods A systematic review was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses
989 (PRISMA) guidelines using a PRISMA checklist.11 Systematic review registration was performed using the PROSPERO International prospective register of systematic reviews (registration number CRD42014012902, dated July 26, 2014).22 Two reviewers independently conducted the search on March 25, 2014, using the Medline, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. The electronic search citation algorithm used was reverse (title/abstract) and shoulder (title/abstract) and arthroplasty (title/abstract) not arthroscopic (title/abstract)not cadaver (title/abstract) not biomechanical (title/abstract). Level I to IV evidence (2011 update by the Oxford Centre for Evidence-Based Medicine21) clinical studies reported in the English language were eligible. References within included studies were cross-referenced for inclusion if missed by the initial search. If a duplicate population was detected, the study with the greater number of patients or the longer duration follow-up was used and the other excluded. Excluded from this review were level V evidence reviews, medical conference abstracts, letters to the editor, cadaveric studies, basic science, biomechanical studies, arthroscopic shoulder surgery, imaging, surgical technique, and classification studies. Patients of interest in this systematic review underwent RTSA for one of many indications, including rotator cuff tear arthropathy, rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, instability, osteonecrosis, pseudoparalysis, bone tumors, locked shoulder dislocation, acute proximal humeral fractures (2-, 3-, and 4-part), and revision from previously failed total shoulder arthroplasty (TSA), open reduction internal fixation, closed reduction percutaneous pinning, or hemiarthroplasty. A minimum of 24 months of clinical follow-up was required, but there was no minimum rehabilitation requirement. Studies that included patients aged <50 years were excluded. Study and subject demographic parameters analyzed included year of publication, years of patient enrollment, presence of study financial conflict of interest, number of shoulders, preoperative and postoperative range of motion (ROM), prosthesis used, and head-neck angle of the prosthesis. Number of dislocations, number of patients with scapular notching, and ROM (when reported) were recorded for all studies. Study methodologic quality was evaluated using the Modified Coleman Methodology Score.4
Statistical analysis Study descriptive statistics were calculated. Continuous variable data are reported as mean standard deviation from the mean. Weighted means and standard deviations were calculated for all patient and demographic parameters. Categoric variable data are reported as frequency with percentages. P < .05 was considered statistically significant for all statistical analysis measured and calculated from study data extraction or directly reported from the individual studies. A two-proportion z test with equal variance and a ¼ 0.05 was used to compare (1) the proportion of shoulders that had undergone RTSA with a subsequent instability event with 135 or 155 inclinations, and (2) the proportion of shoulders that had undergone RTSA with subsequent scapular notching with 135 or 155 inclinations. The z value scores and P values were calculated using a free publicly available calculator (http://insilico.net/tools/statistics/ztest/).
990
B.J. Erickson et al.
Figure 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart. RTSA, reverse total shoulder arthroplasty; TSA, total shoulder arthroplasty.
Results After implementation of the inclusion criteria, 38 studies published between 2006 and 2014 were available for analysis (Fig. 1). Included were 2222 shoulders undergoing RTSA. The 155 inclination prosthesis was used in 1762 (79.3%) and the 135 inclination prosthesis with a lateralized glenosphere was used in 460 (20.7%). The included patients (67% female) were a mean age of 70.3 3.9 years (range, 50-97 years). Average follow-up for the 135 group and the 155 group combined was 37.9 12.2 months (range, 24-78 months) and was 34.61 9.69 months for the 135 group and 38.32 12.62 months 155 group.
A conflict of interest was present in 13 studies (34.2%), absent in 15 (39.5%) studies, and was not reported in 10 studies (26.3%). The average level of evidence of the included studies was 3.7 0.7 (30 studies were level IV evidence, 5 were level III, and 4 were level II). The country with the most studies included in this review was the United States of America (12 studies), followed by France (7 studies). The rate of scapular notching was 2.83% in the 135 group and 16.80% in the 155 group. Significantly more notching was seen in the 155 group (P < .0001; z ¼ 7.7107). The prostheses mentioned in the 135 group all used a lateralized glenosphere. The rate of dislocation
Reverse TSA scapular notching and dislocation
991
Table I Range of motion differences between 135 and 155 prosthesis in external rotation, forward elevation, and abduction Variable) Pre Post P 135 Pre vs post External rotationy Forward elevation Abduction 155 Pre vs post External rotationy Forward elevation Abduction
135 16.1 59.8 56.5 155 13.7 59.1 50.7 Post
7.34 9.28 9.68 5.62 20.2 18.7
135 32.9 119 115 155 23 125.5 105.7
11.3 12.7 9.42
<.0001z <.0001z N/A
88.9 <.0001z 19.13 <.0001z 14.38 N/A
Post
135 155 135 vs 155 External rotationy 32.9 11.3 23 88.9 .0007z Forward elevation 119 12.7 125.5 19.13 .2265 Abduction 115 9.42 105.7 14.38 N/A N/A, not applicable. ) Data are shown as mean standard deviation. y External rotation with the arm at the side. z Statistically significant.
was 1.74% in the 135 group and 2.33% in the 155 group. The difference in the number of dislocations between the 2 groups was not significant (P < .4432; z ¼ –0.7669). The preoperative and postoperative ROM for the 135 the 155 groups are reported in Table I. The 135 prosthesis and the 155 prosthesis both showed significant improvement in forward elevation and external rotation with the arm at the side from preoperatively to postoperatively. The 135 group demonstrated significantly more postoperative external rotation than the 155 group, but the groups did not differ in forward elevation. There was a trend towards more abduction in the 135 group, but statistical analysis could not be performed because too few studies reported this ROM parameter.
Discussion RTSA is a well-described treatment for patients with rotator cuff arthropathy and for several other shoulder pathologies with a deficient rotator cuff.13 We hypothesized that there would be significantly more scapular notching in the 155 group and significantly more dislocations in the 135 group. The primary findings of this study were that rates of scapular notching were higher in the 155 humeral inclination prosthesis than in the 135 humeral inclination prosthesis (Fig. 2), but the dislocation rates were similar. These results confirmed the first hypothesis because significantly more notching occurred in the 155 group, but the second hypothesis was rejected because the rate of dislocation between the 155 and 135 group was not significantly different. The available data on scapular notching and its effect on clinical outcomes are extremely variable, and the clinical
relevance of radiographic scapular notching has not been completely elucidated. The 155 prosthesis is certainly the most widely accepted inclination angle and has been essentially the only prosthesis used in Europe for more than 10 years.5,12,16-18,20,26,28 An inclination of 155 is theorized to improve joint stability, and further, functionally lengthens the deltoid, improving one’s ability to perform forward elevation-based tasks without an intact rotator cuff.6 However, this inclination is associated with a higher rate of scapular notching, which may be associated with midterm to long-term prosthesis failure.8 Boileau et al2 attempted to decrease the rate of scapular notching in patients with a 155 prosthesis by lateralizing the glenoid using cancellous humeral head autograft. The study concluded that the rate of notching decreased (reported in the study at 19%) with bony lateralization without increasing torque on the glenoid component as is seen metallic lateralization. Our review found the scapular notching rate was 16.8% in the 155 prosthesis group, so whether this bony lateralization did decrease the rate of scapular notching is unclear. Further studies comparing patients with and without bony glenoid lateralization are necessary to evaluate the effectiveness of bony lateralization in decreasing scapular notching with a 155 prosthesis. Furthermore, an eccentric glenosphere in a 155 prosthesis may lead to a decrease in scapular notching rates, as demonstrated by De Biase et al,5 but this needs to be studied in a larger patient cohort to determine if the results are reproducible. The 155 prosthesis does not help with the inherent rotation problems associated with RTSA. In contrast, the 135 prosthesis is more anatomic and is associated with a lower rate of scapular notching.3 With this anatomy, the 135 prosthesis may improve internal and external rotation of the joint, although given the sharper angle, the deltoid is not lengthened as it is with the 155 prosthesis. Thus, the 135 prosthesis may not be associated with improvements in forward elevation strength. Critics of the 135 prosthesis have expressed concern regarding a potential for increased joint instability over time, but the results from this review showed no difference in dislocation events in the 155 prosthesis compared with the 135 prosthesis. Table I reports the differences in ROM with the 155 and 135 prostheses, demonstrating significantly less external rotation, with no significant difference in forward elevation, with the 155 compared with the 135 prosthesis. Although the incidence of notching has been reported at between 44% and 96%, substantial variability exists in the results of patients with and without a notch.20,27 Torrens et al23 examined 36 patients with and without a scapular notch at a minimum of 2 years after an RTSA. The difference in Constant or EQ-5D scores between patients with and without a notch was not significant. However, Levigne et al10 monitored 448 patients for a mean of 51 months after implantation of a Grammont style RTSA to determine if patients who developed a scapular notch had inferior
992
B.J. Erickson et al.
Figure 2
Illustration demonstrates the difference between the (Left) 155 and (Right) 135 prosthesis.
clinical outcomes. Overall, they found 68% of patients developed a scapular notch, and those patients who were more active had an increased likelihood of developing a notch earlier in the postoperative period. Patients who had a notch had slightly decreased passive and active anterior elevation as well as a slight decrease (0.5 kg) in strength, but pain and Constant scores were similar to those in patients without a notch.10 From these studies, scapular notching does not appear to cause a clinically significant deficit. A recent biomechanical study by Oh et al15 demonstrated that the 135 prosthesis was less stable to anterior dislocation forces at 30 of internal rotation compared with the 155 prosthesis but that the 135 prosthesis was more stable than the 155 prosthesis in 30 of external rotation. The authors also found that the 155 prosthesis had an adduction impingement angle of 0 , whereas the 135 prosthesis did not impinge until an average of 12 of adduction. The significance of this is that the 155 prosthesis will notch when the arm is resting at the side and not adducted across the body, whereas the 135 prosthesis will not notch until the arm has been adducted across the body. Our study concluded that the 155 prosthesis had a higher rate of scapular notching, as would be expected from the results of the biomechanical study by Oh et al.15 As the study by Oh et al pointed out, the 155 prosthesis was more stable in internal rotation but not as stable in external rotation as the 135 prosthesis, possibly accounting for this lack of difference. In addition to (or instead of) reducing the amount of inclination, other design features, such as the amount of lateral glenoid offset, have been adjusted to decrease the incidence of scapular notching. For example, lateralizing the
glenosphere center of rotation to increase lateral glenoid offset, by using a bone graft (Bio-RSA; Tornier, Saint-Ismier, France) or a lateral offset built into the implant itself (Reverse Shoulder Prosthesis; DJO Surgical, Austin, TX, USA), has been shown to reduce notching.3 Whether increasing the amount of lateral glenoid offset is as effective at decreasing scapular notching compared with decreasing the inclination angle of the humeral component remains unclear. Although the results of this study demonstrate an increased rate of notching in the 155 group, these data must be scrutinized. Valenti et al24 reported a RTSA prosthesis with a less medialized design (more lateral center of rotation) to attempt to correct the problem of scapular notching. The study found no glenoid notching or loosening in 76 patients at an average of 44 months of follow-up. Most of the 135 prostheses included in this study were combined with a lateralized glenosphere, making it difficult to confirm whether the results of this study were solely related to inclination angle of the humeral component. Lastly, there was a significant difference in the postoperative external rotation in the 135 group compared with the 155 group but not a significant difference in forward elevation, although there was a trend toward more forward elevation in the 155 group. The external rotation was statistically significant, but this difference may not correlate with any clinical differences. This study has several limitations. Although 2 authors performed the search, some studies could have been missed, possibly introducing selection bias. Several studies were excluded because there was no mention of the prosthesis that was used. Several studies did not report all of the variables the authors examined, including ROM, leading to inclusion bias.
Reverse TSA scapular notching and dislocation Owing to inconsistent reporting of outcomes by the individual studies included in this review, this study did not address outcome measures and so cannot draw conclusions on the best implant choice or effects of the head-neck angle on objective outcome scores. This study also did not examine any concomitant pathology at the time of surgery, nor did it look at postoperative complications other than those listed in the study. Finally, the clinical relevance of scapular notching cannot be determined by this study.
Conclusions Our systematic review of 38 studies comprising 2222 shoulders found that the 155 prosthesis has a significantly higher rate of scapular notching compared with the 135 prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses.
References 1. Baulot E, Sirveaux F, Boileau P. Grammont’s idea: the story of Paul Grammont’s functional surgery concept and the development of the reverse principle. Clin Orthop Relat Res 2011;469:2425-31. http://dx. doi.org/10.1007/s11999-010-1757-y 2. Boileau P, Moineau G, Roussanne Y, O’Shea K. Bony increased-offset reversed shoulder arthroplasty: minimizing scapular impingement while maximizing glenoid fixation. Clin Orthop Relat Res 2011;469: 2558-67. http://dx.doi.org/10.1007/s11999-011-1775-4 3. Clark JC, Ritchie J, Song FS, Kissenberth MJ, Tolan SJ, Hart ND, et al. Complication rates, dislocation, pain, and postoperative range of motion after reverse shoulder arthroplasty in patients with and without repair of the subscapularis. J Shoulder Elbow Surg 2012;21:36-41. http://dx.doi.org/10.1016/j.jse.2011.04.009 4. Cowan J, Lozano-Calderon S, Ring D. Quality of prospective controlled randomized trials. Analysis of trials of treatment for lateral epicondylitis as an example. J Bone Joint Surg Am 2007;89:1693-9. http://dx.doi.org/10.2106/JBJS.F.00858 5. De Biase CF, Delcogliano M, Borroni M, Castagna A. Reverse total shoulder arthroplasty: radiological and clinical result using an eccentric glenosphere. Musculoskelet Surg 2012;96(Suppl 1):S27-34. http://dx.doi.org/10.1007/s12306-012-0193-4 6. Favard L, Levigne C, Nerot C, Gerber C, De Wilde L, Mole D. Reverse prostheses in arthropathies with cuff tear: are survivorship and function maintained over time? Clin Orthop Relat Res 2011;469:246975. http://dx.doi.org/10.1007/s11999-011-1833-y 7. Flatow EL, Harrison AK. A history of reverse total shoulder arthroplasty. Clin Orthop Relat Res 2011;469:2432-9. http://dx.doi.org/10. 1007/s11999-010-1733-6 8. Groh GI, Groh GM. Complications rates, reoperation rates, and the learning curve in reverse shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:388-94. http://dx.doi.org/10.1016/j.jse.2013.06.002 9. Hyun YS, Huri G, Garbis NG, McFarland EG. Uncommon indications for reverse total shoulder arthroplasty. Clin Orthop Surg 2013;5:24355. http://dx.doi.org/10.4055/cios.2013.5.4.243 10. Levigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop Relat Res 2011;469:2512-20. http://dx.doi.org/ 10.1007/s11999-010-1695-8
993 11. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gotzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009;62: e1-34. http://dx.doi.org/10.1016/j.jclinepi.2009.06.006 12. Martinez AA, Bejarano C, Carbonel I, Iglesias D, Gil-Albarova J, Herrera A. The treatment of proximal humerus nonunions in older patients with reverse shoulder arthroplasty. Injury 2012;43(Suppl 2): S3-6. http://dx.doi.org/10.1016/S0020-1383(13)70172-4 13. Nicholson GP, Strauss EJ, Sherman SL. Scapular notching: recognition and strategies to minimize clinical impact. Clin Orthop Relat Res 2011;469:2521-30. http://dx.doi.org/10.1007/s11999-010-1720-y 14. Nyffeler RW, Werner CM, Simmen BR, Gerber C. Analysis of a retrieved Delta III total shoulder prosthesis. J Bone Joint Surg Br 2004;86:1187-91. http://dx.doi.org/10.1302/0301-620X.86B8.15228 15. Oh JH, Shin SJ, McGarry MH, Scott JH, Heckmann N, Lee TQ. Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:1091-8. http://dx.doi.org/10.1016/j.jse.2013.11.003 16. Randelli P, Randelli F, Arrigoni P, Ragone V, D’Ambrosi R, Masuzzo P,, et al. Optimal glenoid component inclination in reverse shoulder arthroplasty. How to improve implant stability. Musculoskelet Surg 2014;98(Suppl):15-8. http://dx.doi.org/10.1007/s12306-014-0324-1 17. Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg 2001;10:17-22. 18. Sayana MK, Kakarala G, Bandi S, Wynn-Jones C. Medium term results of reverse total shoulder replacement in patients with rotator cuff arthropathy. Ir J Med Sci 2009;178:147-50. http://dx.doi.org/10.1007/ s11845-008-0262-8 19. Scarlat MM. Complications with reverse total shoulder arthroplasty and recent evolutions. Int Orthop 2013;37:843-51. http://dx.doi.org/10. 1007/s00264-013-1832-6 20. Simovitch RW, Zumstein MA, Lohri E, Helmy N, Gerber C. Predictors of scapular notching in patients managed with the Delta III reverse total shoulder replacement. J Bone Joint Surg Am 2007;89: 588-600. http://dx.doi.org/10.2106/JBJS.F.00226 21. The University of Oxford. Centre for Evidence Based Medicine. OCEBM 2011 levels of evidence system. Available at: http://www. cebm.net/index.aspx?o¼5653. Accessed August 1, 2014. 22. The University of York. Centre for Reviews and Dissemination. PROSPERO - International prospective register of systematic reviews. Available at: http://www.crd.york.ac.uk/PROSPERO/. Accessed August 14, 2014. 23. Torrens C, Santana F, Picazo B, Caceres E. Retrospective study of scapular notches in reverse shoulder arthroplasties. Am J Orthop (Belle Mead NJ) 2013;42:362-5. 24. Valenti P, Sauzieres P, Katz D, Kalouche I, Kilinc AS. Do less medialized reverse shoulder prostheses increase motion and reduce notching? Clin Orthop Relat Res 2011;469:2550-7. http://dx.doi.org/ 10.1007/s11999-011-1844-8 25. Vanhove B, Beugnies A. Grammont’s reverse shoulder prosthesis for rotator cuff arthropathy. A retrospective study of 32 cases. Acta Orthop Belg 2004;70:219-25. 26. Wall B, Nove-Josserand L, O’Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85. http://dx.doi.org/10. 2106/JBJS.F.00666 27. Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86. http://dx.doi.org/10.2106/JBJS.D. 02342 28. Young AA, Smith MM, Bacle G, Moraga C, Walch G. Early results of reverse shoulder arthroplasty in patients with rheumatoid arthritis. J Bone Joint Surg Am 2011;93:1915-23. http://dx.doi.org/10.2106/JBJS. J.00300