- Email: [email protected]
Contemporary use of reverse total shoulder arthroplasty
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M I N A R S I N
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] (2016) ]]]–]]]
Available online at www.sciencedirect.com
www.elsevier.com/locate/semanthroplasty
Contemporary use of reverse total shoulder arthroplasty Sydney C. Cryder, BS, OMSa,n, and Brian S. Cohen, MDb a
Department of Medicine, Ohio University Heritage College of Osteopathic Medicine, Grosvenor Hall, Athens, OH 45701 b The Adena Bone and Joint Center, Adena Regional Medical Center, Chillicothe, OH
article info
abstra ct
Keywords:
Reverse total shoulder arthroplasty (RTSA) has evolved as the treatment for glenohumeral
Reverse total shoulder arthroplasty
joint disease in patients with rotator cuff pathology because it allows for the deltoid to be
Humans
further recruited during abduction. Surgical procedure for an RTSA can be done via two
Biomechanical phenomena
approaches, deltopectoral and superolateral. The most commonly reported complications
Joint prosthesis
include infection, dislocation, humeral fracture, glenoid fracture, hematoma, neurological
Range of motion
damage, implant loosening, and scapular notching. The RTSA has become prominent in
Rotator cuff injury
the treatment of shoulder pathology due to its ability to treat a gamut of complex disorders,
Shoulder joint physiology/surgery
while awarding pain relief and enhanced functional range of motion.
Treatment outcome
1.
Introduction
In the late 1980s, Paul Grammont introduced a gamechanging design for the reverse total shoulder prosthesis that was based on four core principles, listed as follows: (1) the center of rotation must be fixed, medialized, and distalized with respect to the glenoid surface, (2) prosthesis must be inherently stable, (3) the lever arm of the deltoid must be effective from the initiation of the movement, and (4) the glenosphere must be large and the humeral cup small to create a semi-constrained articulation [1,2]. Although Grammont’s principles have been the mainstay, the modern prosthetics have been modified to avoid scapular notching, impingement between the greater tuberosity and the coracoacromial arch, and maximize compressive forces while minimizing shear forces [2,3]. Between 2006 and 2011, the utilization of reverse total shoulder arthroplasty (RTSA) nearly tripled and continues to rise [4]. RTSA has gained popularity with its ability to alleviate pain and increase range
n
Corresponding author. E-mail address: [email protected] (S.C. Cryder).
http://dx.doi.org/10.1053/j.sart.2016.08.005 1045-4527/& 2016 Elsevier Inc. All rights reserved.
& 2016 Elsevier Inc. All rights reserved.
of motion in patients with glenohumeral joint disease and rotator cuff tear arthropathy, severe irreparable rotator cuff tears, rheumatoid arthritis, or failed shoulder arthroplasty [1–3,5]. RTSA has evolved as the treatment for glenohumeral joint disease in patients with rotator cuff pathology because it allows for the deltoid to be further recruited during abduction, compensating for the dysfunctional rotator cuff [2,3]. This is accomplished through moving the joint’s center of rotation medially and distally, which lengthens the moment arm of the deltoid, increases the deltoid’s ability to produce torque, and adds tension to the deltoid [1–3]. Additionally, using a larger glenoid component with no neck provides inherent stability while aiding in abduction and adduction of the shoulder joint, decreasing shear forces and the occurrence of notching [3,6]. The surgical technique for RTSA can be done via two approaches, deltopectoral and superolateral; although, deltopectoral is most commonly employed, the approach must be
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determined using surgeon experience and patient factors [3,6,7]. The surgical technique begins with an incision overlying the deltopectoral interval, preserving the cephalic vein, then tenotomizing the biceps tendon and the subscapularis if still intact [3,6,8]. Next, the joint capsule is circumferentially released and humeral head exposed to perform a humeral head osteotomy. The humeral head is then reamed and broached. Subsequently, the glenoid is exposed, the labrum excised, and the glenoid prepared. The guidewire for the glenoid reamer is placed inferiorly so that the glenoid baseplate will be flush with the inferior border of the native glenoid rim. This will help decrease the risk of scapular notching. By adding an inferior tilt to the position of the baseplate, the risk of scapular notching can be further decreased, as well as improve compressive forces and avoid shear forces on the glenoid component. The baseplate is impacted in place, and secured with screws to securely fix the baseplate to the patient’s native glenoid. The glenosphere that has been chosen is then secured to the baseplate with a Morse Taper fixation mechanism. The choice of which glenosphere to use is multifactorial. It is based not only on the patient’s size, 42 mm for larger patients, 39 mm for “average” size patients, and 36 mm for smaller patients, but on individual patient specific pathologies. The glenospheres are available in central, lateral offset, or inferior offset designs. The humeral stem is prepared, by first “sounding” the inner diameter of the humeral shaft, then broaching to the appropriate size. The final implant is tested with the spacer trials to gain the appropriate amount of stability and motion. Once the construct is determined, the real implants are seated and the shoulder is reduced. Finally, the subscapularis is reattached and biceps is tenodesed with heavy nonabsorbable sutures that are placed through drill holes in the humeral metaphysis prior to seating of the final implant. However, recent research acknowledges the controversy surrounding the reattachment of the subscapularis due to the potential for increasing the likelihood of dislocation [9]. The deltopectoral interval is re-approximated and the incision closed. The patient is placed in a shoulder abduction sling. According to Jarrett et al. [10], a period of immobilization for 2–6 weeks with a home physical therapy program is a suitable plan for a patient following RTSA. As with all orthopedic procedures, the rehabilitation protocol chosen is patient specific. Additional rehabilitation may be considered if the patient needs further strengthening in external rotation [10].
2.
] (2016) ]]]–]]]
include infection, dislocation, humeral fracture, glenoid fracture, hematoma, neurological injury, implant loosening, and scapular notching [5,11,13]. Additionally, the risk of complications nearly doubles with patients undergoing revision surgery as opposed to primary RTSA surgical patients [11].
3.
Rotator cuff tear arthropathy
In a healthy individual, the humeral head is approximately twice as large as the glenoid surface, which allows for a large breadth of functional range of motion. The joint is awarded its stability from tendons, muscles, and ligaments. The rotator cuff provides stability and compressive forces throughout the ranges of motion [3]. However, in a patient with rotator cuff arthropathy, the functional range of motion is often diminished. The supraspinatus is most commonly involved in rotator cuff arthropathy and when deficient, causes the humeral head to migrate superiorly, creating abnormal pressure and wear on the superior glenoid, acromion, and coracoid [3]. The stages of severity of rotator cuff tear arthropathy may be determined using Hamada–Walsh classification system [11,14]. Stage 1 is associated with slight radiographic changes; stage 2 demonstrates diminished subacromial space (r 5 mm); stage 3 is demarcated by erosion and “acetabularization” of the acromion as a result of superior migration of the humeral head; stage 4 shows glenohumeral arthritis with acetabularization/femoralization (4a) or without acetabularization/femoralization (4b); and stage 5 is illustrated by humeral head osteonecrosis [11].
4.
Component wear and loosening
Nam et al. [3] and Wiater et al. [5] both found that scratching, abrasion, and pitting were the most common modes of damage in the poly components of the RTSA. Damage was observed most frequently in the inferior quadrant, which was attributed to impingement between the scapula and humeral poly component [3]. Component loosening occurred as a result of improper fixation of the glenoid component and inadequate anchoring of a bone graft to native bone [11]. Wiater et al. [5] concluded that damage modes of the components significantly correlated to radiographic and clinical findings; thus, accelerated component wear may lead to premature failure of the RTSA implants.
Surgical outcomes 5.
RTSA has become prominent in the treatment of shoulder pathology due to its ability to treat a gamut of complex disorders, while awarding pain relief and enhanced functional range of motion [5]. Wall et al. [11] and Roy et al. [12] conducted separate studies, both of which concluded that patients experienced a reduction in pain, and improved functional range of motion in elevation, external rotation, and internal rotation. Although RTSA potentiates major improvements for shoulder pathology, it also poses several complications, with rates ranging from 19% to nearly 60% [5,11–13]. The most commonly reported complications
Deltoid engagement
The deltoid muscle plays a major role in the functional range of motion following RTSA; however, excessive load may lead to acromion fracture and chronic muscle fatigue [15]. Overrecruitment of the deltoid increases the load placed upon the joint, which amplifies the risk of implant component wear and failure. Giles et al. [15] measured the effects of humeral component lateralization, glenosphere lateralization, and poly cup thickness, on the joint loading outcomes due to muscle moment arms. They observed that humeral lateralization decreased the deltoid force, glenosphere lateralization
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increases deltoid force, and an increased thickness poly increased the deltoid force necessary for abduction. Further, Giles et al. [15] determined that humeral and glenosphere lateralization worked synergistically to decrease deltoid force. The thickness of the poly component and glenosphere lateralization also demonstrated increases in joint load [15]. In patients with rotator cuff insufficiency, adequate activation, and recruitment of the deltoid is an important factor in functional range of motion. Berliner et al. [2] stated that the role of the deltoid changes to accommodate functionality of the shoulder. In a healthy shoulder, the anterior deltoid acts primarily as a flexor, the middle deltoid acts primarily as an abductor, and the posterior deltoid acts primarily as an extensor. Whereas following the RTSA, each division of the deltoid acts primarily as an abductor [2]. Berliner et al. [2] concluded that maintenance of the shoulder girdle musculature intra- and post-operatively is crucial in order to antagonize the shear forces created by the deltoid.
6.
Patient demographics
Westermann et al. [4] conducted a study evaluating the varying demographics between traditional anatomic total shoulder arthroplasty (TSA), RTSA, and hemiarthroplasty (HA). In 2011, the mean age of patients undergoing a TSA or HA, approximately 67 years, was significantly younger than those receiving the RTSA, approximately 73 years. Further, Westermann and colleagues found that the use of HA decreased by 12.5% between 2002 and 2011. Additionally, the indications for each procedure varied, as TSA was more commonly utilized in patients with the primary diagnosis of osteoarthritis and HA was used more often in patients with a proximal humeral fracture [4]. Whereas, the RTSA was the treatment in patients with a primary diagnosis of partial or massive rotator cuff tears [4]. Padegimas et al. [16] examined the issues presented when patients younger than 55 years required treatment of severe shoulder pathology and rotator cuff insufficiency. Treatment of younger patients presents a greater challenge due to an increased life expectancy, activity level, and lifestyle [14,16]. Moreover, long-term implant success rate is a concern in younger patients; thus, putting younger patients at a higher risk for revision in the long term. However, Ek et al. [14] found that RTSA produced excellent results in no less than 10 years, despite the unforeseen obstacles in the cohort. The demand for shoulder arthroplasty is projected to increase among the younger populations; however, the greatest increase is expected in the older population [16].
7.
Patient return to activity
Garcia et al. [17] conducted a study to evaluate patients’ return to activity following RTSA. On average, patients returned to sporting activities in approximately 5 months with 85.5% of patients resuming at least one sporting activity. This result is comparable to the rate of return to sporting activity following TSA [17]. The results also demonstrated that fitness sports, swimming, and running had the highest
] (2016) ]]]–]]]
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rate of return. Importantly, age was a significant predictor of return, with an age at or above 70 correlating to a reduced return rate [17].
8.
Case presentation
The following is a case presentation that represents the a commonly used protocol for a RTSA.
8.1.
Patient
A 69-year-old male patient presents with left shoulder pain and limited range of motion [18]. He is right hand dominant and an avid outdoorsman. In 1964, while in the United States Air Force, he sustained an injury to the left shoulder after falling off of a B-58 bomber wing; which was repaired with two screws that were removed 6 months later. In 1995, after living with limited range of motion, his collar bone was shortened. Then in 1999, he suffered a biceps muscle rupture that was managed nonoperatively. Plain radiographs revealed proximal humeral migration and femoralization of the humeral head underneath the acromion, all consistent with rotator cuff insufficiency. The axillary view showed asymmetric wear pattern with the humeral head centered in the glenoid. Furthermore, on MRI, proximal humeral migration and a large retracted rotator cuff tear of the supraspinatus tendon all the way to the level of the glenoid, was observed. The subscapularis and infraspinatus were intact with some fatty infiltration, while the fatty infiltration of the supraspinatus alluded to the chronic nature of the rotator cuff insufficiency.
8.2.
Surgical approach
Pre-operatively, the patient was given an interscalene block. In some cases, patients may be paralyzed intraoperatively to augment glenoid exposure. Generally, patients are positioned at 25–301 of incline. A standard deltopectoral approach was used utilizing some of the patient’s previous scars.
8.3.
Humeral head preparation
Caution was taken to avoid damage to the cephalic vein, by mobilizing it medially with the pectoralis major, and the musculocutaneous nerve was protected using small Richardson retractors. No biceps tendon was identified, consistent with the patient’s history. A peel technique was employed to release the subscapularis off the lesser tuberosity. Sutures were used to tag the superior and inferior edges of the subscapularis and provide traction. The anterior circumflex vessels were ligated. A pointed Hohmann retractor was used to protect the neurovascular structures while dislocating the humeral head. The characteristic “bald head” of the humerus was clearly observed, further confirming the chronicity of the rotator cuff tear (Fig. 1). The humeral cut was made along the anatomic neck, consistent with the patient’s anatomic version. Inferior, superior, and medial borders were defined with retractors to avoid injury to the posterior rotator cuff.
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Fig. 1 – Retractor definition of boarders in preparation for the anatomical humeral neck cut. Demonstration of the characteristic "bald head" [18]. The humeral surface is sized and broached for a neck angle inclination of 1351, also limiting the risk of scapular notching when compared with a component that sits at 1551 angle [18]. Unique to each patient is the offset of the humeral head in relation to the humeral diaphysis. Most patients have a posterior offset of the humeral head. So an implant that recreates this posterior offset position is chosen. The Arthrex reverse shoulder system (Arthrex, Inc., Naples, FL, 2015), used in this case, is a totally cement-less system. Erickson et al. [19] concluded that an inclination of 1351 had a reduced rate of scapular notching compared to a 1551 implant. Furthermore, inclination angle of 1351 decreased the minimum abduction angle in comparison to an inclination of 1551 [20]. The lateralization of the glenosphere also acts to incorporate the deltoid more and give the patient more of an anatomic appearing shoulder [18]; in addition to decreasing the minimum abduction angle and the rate of scapular notching [2,20] (Fig. 2).
8.4.
Glenoid preparation
The back of the glenoid was fully exposed and the inferior capsule was released first. The axillary nerve was palpated while the capsule was released to the 6 o’clock position and the middle glenohumeral ligament was transected. The capsule was not excised so that the tissue was maintained for the subscapular repair at the end of the case. The labrum was removed to provide excellent glenoid exposure and avoid soft tissue impingement (Fig. 3).
Fig. 2 – Demonstration of the desired angle of inclination and lateral offset of the humeral component. [18]
] (2016) ]]]–]]]
Fig. 3 – Glenoid exposure following soft tissue removal and preparation. [18] A guide was used to determine the position of the baseplate while achieving slight inferior tilt of the component to help decrease the risk of notching. With regard to bone grafting for the glenoid, pre-operative imaging can be used to determine if a bone graft is necessary and required. When placing the screws, the inferior peripheral screw is drilled first, then the superior screw, and finally the central screw. The superior screw is aimed anterior to avoid penetration into the suprascapular notch and a potential injury to the suprascapular nerve. Additionally, posterior placement of the screw may create a stress riser in the scapular spine, increasing the risk of fracture. The inferior screw is seated first to pull the baseplate into an inferior position, followed by the central and superior screw. A central screw depth gage is used to assess if the central screw is engaged deep enough to allow the Morse Taper of the glenosphere to be fully seated. The surgeon operating on this patient has completed approximately 350 RTSAs using the Arthrex reverse system (Arthrex, Inc., Naples, FL, 2015) without any baseplate failures or glenosphere dissociations [18]. The glenoid implant is an Arthrex two-stage flat back with press-fit fixation, fenestrations, and hydroxyapatite on the back to aid in fixation to the patient’s native bone. The glenosphere is reduced by placing the sphere on the cut surface of the humerus, lining it up with the Morris taper hole, then internally rotating the arm to snap the glenosphere into the baseplate. After impaction, a “glenosphere-checker” is used to verify the engagement of the sphere to the baseplate.
8.5.
Closing surgical remarks
As previously stated, the Arthrex reverse shoulder system (Arthrex, Inc., Naples, FL, 2015) is totally cement-less, which clearly eliminates the use of antibiotic cement, although cemented options are available. However, even in the use of approximately 66 RTSA cases that were completed for fractures, the infection rate was zero percent [18]. Spacer components may be used to build up the stability on the humeral side of the system and the Arthrex system is a “screw-in fixation” that allows the screw to lock down without rotating the implant, signifying very good humeral fixation [18]. Finally, the outcomes and stability of the shoulder following an RTSA seem to depend on the choice of implant [18]. Refer to the Table for a comprehensive list of tools and implants utilized during RTSA.
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Table – Preferential Tools and Implants Utilized During the RTSA [18,21] Tool, Implant
Rationale
Humeral stem 1351, 1551
1351 is used in majority of cases, this angle aids in range of motion; 1551 is used when patient stability is a concern Largely depends on the patient anatomy Standard is most commonly employed; Constrained is only used when patient stability is a concern or if the patient is walker, cane, or wheelchair dependent Lateralized to help shift the patient’s humerus away from the glenoid and prevent notching Determine the placement and depth of the central screw Reaming for the central screw; Prepare the glenoid Ream the entire circumference of the glenoid in preparation for baseplate placement; size determined by the size of the glenoid Impact the baseplate onto the prepared glenoid surface Achievement of the desired trajectory and depth of the inferior and superior screws; screws may be placed and seated Aid in placement, seating, and engagement of the central screw Confirm that the central screw is appropriately seated within the baseplate hole Longer shaft allows distance from the glenoid Aids in verifying that the glenosphere will completely seat and engage Preparation of the humeral canal for broaching and implantation; T-Handle Achievement of proper broach sizes and version in the humeral canal
Humeral cups Humeral polyethylene liners Glenosphere 2.8-mm Glenoid guide wire Primary post reamer Final reamer Baseplate impactor Peripheral screw drill guide, inferior/ superior bushing Central screw tap Central Screw Depth Gauge T15 Torx Driver (long) Coring reamer Humeral IM reamer (6 mm) Humeral broach alignment guide, broach handle Humeral broaches Humeral cup reamer Humeral trial cup Trial humeral liner European glenosphere Inserter Glenosphere impactor Glenosphere forceps Pointed impactor Extractors Humeral spacers Revision humeral stems
9.
Sizes 6–13; Placement of the stem into the humeral cut Confirm accurate fit of the humeral cup into the stem Match correct sizing prior to placing final implant Test fit in the actual implant to give the most exact fit Insertion of the glenosphere onto the glenoid baseplate Guarantee proper security and engagement of the Morse Taper Corroborate the validity of the Morse Taper connection Used in seating the humeral cup into the stem For the glenoid baseplate and humeral stem/ cup, only when performing a revision procedure Only used when a greater space must be filled Extended stem length allows for passage beyond humeral fracture sites
Results
For post-operative rehabilitation, the patient was placed into an abducted sling, in which the abduction component was removed on post-operative day 1. Then, the sling was no longer required and used only for comfort. The patient was advised to avoid movements that included extension, crossbody adduction, and direct abduction. The patient started physical therapy and received home therapy exercises prior to being discharged. Post-operative imaging verified appropriate alignment of the implants.
Conclusion RTSA is an effective treatment for patients with rotator cuff tear arthropathy, whereas the traditional anatomic total shoulder arthroplasty is often not an option for these patients given their cuff deficiency. The geometry of the implant components plays a major role in the success of the implant and the patient outcomes. Also, RTSA may be an appropriate option for patients undergoing revision shoulder arthroplasty. Conversely, RTSA presents several complications, most commonly including infection, dislocation, and scapular notching. Despite the risk of complications, patients
experience an improvement in pain and functional range of motion overall.
Disclosure Sydney C. Cryder, BS has no conflicts of interest to declare. Brian S. Cohen, MD: Arthrex Consultant, Royalties received, but none on Arthrex Univers Revers implants
refere nces
[1] Drake GN, O’Connor DP, Edwards TB. Indications for reverse total shoulder arthroplasty in rotator cuff disease. Clinical orthopaedics and related research 2010;468:1526–33. [2] Berliner JL, Regalado-Magdos A, Ma CB, Feeley BT. Biomechanics of reverse total shoulder arthroplasty. Journal of shoulder and elbow surgery/American Shoulder and Elbow Surgeons ... [et al.] 2015;24:150–60. [3] Nam D, Kepler CK, Neviaser AS, et al. Reverse total shoulder arthroplasty: current concepts, results, and component wear analysis. The Journal of bone and joint surgery. American volume 2010;92(Suppl 2):23–35. [4] Westermann RW, Pugely AJ, Martin CT, Gao Y, Wolf BR, Hettrich CM. Reverse shoulder arthroplasty in the United States: a comparison of national volume, patient demographics, complications, and surgical indications. The Iowa orthopaedic journal 2015;35:1–7.
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[5] Wiater BP, Baker EA, Salisbury MR, et al. Elucidating trends in revision reverse total shoulder arthroplasty procedures: a retrieval study evaluating clinical, radiographic, and functional outcomes data. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 2015;23:1–11. [6] Gerber BS, Brodsky IG, Lawless KA, et al. Implementation and evaluation of a low-literacy diabetes education computer multimedia application. Diabetes care 2005;28:1574–80. [7] Dilisio MF, Miller LR, Siegel EJ, Higgins LD. Conversion to reverse shoulder arthroplasty: humeral stem retention versus revision. Orthopedics 2015;38:e773–9. [8] Wierks C, Skolasky RL, Ji JH, McFarland EG. Reverse total shoulder replacement: intraoperative and early postoperative complications. Clinical orthopaedics and related research 2009;467:225–34. [9] Zhou HS, Chung JS, Yi PH, Li X, Price MD. Management of complications after reverse shoulder arthroplasty. Current reviews in musculoskeletal medicine 2015;8:92–7. [10] Jarrett CD, Brown BT, Schmidt CC. Reverse shoulder arthroplasty. The Orthopedic clinics of North America 2013;44 (3):389–408 x. [11] Wall B, Nove-Josserand L, O’Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. The Journal of bone and joint surgery. American volume 2007;89:1476–85. [12] Roy JS, Macdermid JC, Goel D, Faber KJ, Athwal GS, Drosdowech DS. What is a successful outcome following reverse total shoulder arthroplasty? The open orthopaedics journal 2010;4:157–63. [13] Cheung E, Willis M, Walker M, Clark R, Frankle MA. Complications in reverse total shoulder arthroplasty. The Journal of the American Academy of Orthopaedic Surgeons 2011;19:439–49.
] (2016) ]]]–]]]
[14] Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. 2013;22:1199–208. [15] Giles JW, Langohr GD, Johnson JA, Athwal GS. Implant design variations in reverse total shoulder arthroplasty influence the required deltoid force and resultant joint load. Clinical orthopaedics and related research 2015;473:3615–26. [16] Padegimas EM, Maltenfort M, Lazarus MD, Ramsey ML, Williams GR, Namdari S. Future patient demand for shoulder arthroplasty by younger patients: national projections. Clinical orthopaedics and related research 2015;473:1860–7. [17] Garcia GH, Taylor SA, DePalma BJ, et al. Patient activity levels after reverse total shoulder arthroplasty: what are patients doing? The American journal of sports medicine 2015;43: 2816–21. [18] Reverse Shoulder Arthroplasty. Cleveland, OH: Current Concepts Institute; 2015. [19] Erickson BJ, Frank RM, Harris JD, Mall N, Romeo AA. The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 2015;24:988–93. [20] North LR, Hetzler MA, Pickell M, Bryant JT, Deluzio KJ, Bicknell RT. Effect of implant geometry on range of motion in reverse shoulder arthroplasty assessed using glenohumeral separation distance. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. 2015;24:1359–66. [21] Univers Revers Surgical Technique. Naples, FL: Arthrex, Inc; 2014;2014.
M I N A R S I N
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R T H R O P L A S T Y
] (2016) ]]]–]]]
Available online at www.sciencedirect.com
www.elsevier.com/locate/semanthroplasty
Contemporary use of reverse total shoulder arthroplasty Sydney C. Cryder, BS, OMSa,n, and Brian S. Cohen, MDb a
Department of Medicine, Ohio University Heritage College of Osteopathic Medicine, Grosvenor Hall, Athens, OH 45701 b The Adena Bone and Joint Center, Adena Regional Medical Center, Chillicothe, OH
article info
abstra ct
Keywords:
Reverse total shoulder arthroplasty (RTSA) has evolved as the treatment for glenohumeral
Reverse total shoulder arthroplasty
joint disease in patients with rotator cuff pathology because it allows for the deltoid to be
Humans
further recruited during abduction. Surgical procedure for an RTSA can be done via two
Biomechanical phenomena
approaches, deltopectoral and superolateral. The most commonly reported complications
Joint prosthesis
include infection, dislocation, humeral fracture, glenoid fracture, hematoma, neurological
Range of motion
damage, implant loosening, and scapular notching. The RTSA has become prominent in
Rotator cuff injury
the treatment of shoulder pathology due to its ability to treat a gamut of complex disorders,
Shoulder joint physiology/surgery
while awarding pain relief and enhanced functional range of motion.
Treatment outcome
1.
Introduction
In the late 1980s, Paul Grammont introduced a gamechanging design for the reverse total shoulder prosthesis that was based on four core principles, listed as follows: (1) the center of rotation must be fixed, medialized, and distalized with respect to the glenoid surface, (2) prosthesis must be inherently stable, (3) the lever arm of the deltoid must be effective from the initiation of the movement, and (4) the glenosphere must be large and the humeral cup small to create a semi-constrained articulation [1,2]. Although Grammont’s principles have been the mainstay, the modern prosthetics have been modified to avoid scapular notching, impingement between the greater tuberosity and the coracoacromial arch, and maximize compressive forces while minimizing shear forces [2,3]. Between 2006 and 2011, the utilization of reverse total shoulder arthroplasty (RTSA) nearly tripled and continues to rise [4]. RTSA has gained popularity with its ability to alleviate pain and increase range
n
Corresponding author. E-mail address: [email protected] (S.C. Cryder).
http://dx.doi.org/10.1053/j.sart.2016.08.005 1045-4527/& 2016 Elsevier Inc. All rights reserved.
& 2016 Elsevier Inc. All rights reserved.
of motion in patients with glenohumeral joint disease and rotator cuff tear arthropathy, severe irreparable rotator cuff tears, rheumatoid arthritis, or failed shoulder arthroplasty [1–3,5]. RTSA has evolved as the treatment for glenohumeral joint disease in patients with rotator cuff pathology because it allows for the deltoid to be further recruited during abduction, compensating for the dysfunctional rotator cuff [2,3]. This is accomplished through moving the joint’s center of rotation medially and distally, which lengthens the moment arm of the deltoid, increases the deltoid’s ability to produce torque, and adds tension to the deltoid [1–3]. Additionally, using a larger glenoid component with no neck provides inherent stability while aiding in abduction and adduction of the shoulder joint, decreasing shear forces and the occurrence of notching [3,6]. The surgical technique for RTSA can be done via two approaches, deltopectoral and superolateral; although, deltopectoral is most commonly employed, the approach must be
2
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AR
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determined using surgeon experience and patient factors [3,6,7]. The surgical technique begins with an incision overlying the deltopectoral interval, preserving the cephalic vein, then tenotomizing the biceps tendon and the subscapularis if still intact [3,6,8]. Next, the joint capsule is circumferentially released and humeral head exposed to perform a humeral head osteotomy. The humeral head is then reamed and broached. Subsequently, the glenoid is exposed, the labrum excised, and the glenoid prepared. The guidewire for the glenoid reamer is placed inferiorly so that the glenoid baseplate will be flush with the inferior border of the native glenoid rim. This will help decrease the risk of scapular notching. By adding an inferior tilt to the position of the baseplate, the risk of scapular notching can be further decreased, as well as improve compressive forces and avoid shear forces on the glenoid component. The baseplate is impacted in place, and secured with screws to securely fix the baseplate to the patient’s native glenoid. The glenosphere that has been chosen is then secured to the baseplate with a Morse Taper fixation mechanism. The choice of which glenosphere to use is multifactorial. It is based not only on the patient’s size, 42 mm for larger patients, 39 mm for “average” size patients, and 36 mm for smaller patients, but on individual patient specific pathologies. The glenospheres are available in central, lateral offset, or inferior offset designs. The humeral stem is prepared, by first “sounding” the inner diameter of the humeral shaft, then broaching to the appropriate size. The final implant is tested with the spacer trials to gain the appropriate amount of stability and motion. Once the construct is determined, the real implants are seated and the shoulder is reduced. Finally, the subscapularis is reattached and biceps is tenodesed with heavy nonabsorbable sutures that are placed through drill holes in the humeral metaphysis prior to seating of the final implant. However, recent research acknowledges the controversy surrounding the reattachment of the subscapularis due to the potential for increasing the likelihood of dislocation [9]. The deltopectoral interval is re-approximated and the incision closed. The patient is placed in a shoulder abduction sling. According to Jarrett et al. [10], a period of immobilization for 2–6 weeks with a home physical therapy program is a suitable plan for a patient following RTSA. As with all orthopedic procedures, the rehabilitation protocol chosen is patient specific. Additional rehabilitation may be considered if the patient needs further strengthening in external rotation [10].
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include infection, dislocation, humeral fracture, glenoid fracture, hematoma, neurological injury, implant loosening, and scapular notching [5,11,13]. Additionally, the risk of complications nearly doubles with patients undergoing revision surgery as opposed to primary RTSA surgical patients [11].
3.
Rotator cuff tear arthropathy
In a healthy individual, the humeral head is approximately twice as large as the glenoid surface, which allows for a large breadth of functional range of motion. The joint is awarded its stability from tendons, muscles, and ligaments. The rotator cuff provides stability and compressive forces throughout the ranges of motion [3]. However, in a patient with rotator cuff arthropathy, the functional range of motion is often diminished. The supraspinatus is most commonly involved in rotator cuff arthropathy and when deficient, causes the humeral head to migrate superiorly, creating abnormal pressure and wear on the superior glenoid, acromion, and coracoid [3]. The stages of severity of rotator cuff tear arthropathy may be determined using Hamada–Walsh classification system [11,14]. Stage 1 is associated with slight radiographic changes; stage 2 demonstrates diminished subacromial space (r 5 mm); stage 3 is demarcated by erosion and “acetabularization” of the acromion as a result of superior migration of the humeral head; stage 4 shows glenohumeral arthritis with acetabularization/femoralization (4a) or without acetabularization/femoralization (4b); and stage 5 is illustrated by humeral head osteonecrosis [11].
4.
Component wear and loosening
Nam et al. [3] and Wiater et al. [5] both found that scratching, abrasion, and pitting were the most common modes of damage in the poly components of the RTSA. Damage was observed most frequently in the inferior quadrant, which was attributed to impingement between the scapula and humeral poly component [3]. Component loosening occurred as a result of improper fixation of the glenoid component and inadequate anchoring of a bone graft to native bone [11]. Wiater et al. [5] concluded that damage modes of the components significantly correlated to radiographic and clinical findings; thus, accelerated component wear may lead to premature failure of the RTSA implants.
Surgical outcomes 5.
RTSA has become prominent in the treatment of shoulder pathology due to its ability to treat a gamut of complex disorders, while awarding pain relief and enhanced functional range of motion [5]. Wall et al. [11] and Roy et al. [12] conducted separate studies, both of which concluded that patients experienced a reduction in pain, and improved functional range of motion in elevation, external rotation, and internal rotation. Although RTSA potentiates major improvements for shoulder pathology, it also poses several complications, with rates ranging from 19% to nearly 60% [5,11–13]. The most commonly reported complications
Deltoid engagement
The deltoid muscle plays a major role in the functional range of motion following RTSA; however, excessive load may lead to acromion fracture and chronic muscle fatigue [15]. Overrecruitment of the deltoid increases the load placed upon the joint, which amplifies the risk of implant component wear and failure. Giles et al. [15] measured the effects of humeral component lateralization, glenosphere lateralization, and poly cup thickness, on the joint loading outcomes due to muscle moment arms. They observed that humeral lateralization decreased the deltoid force, glenosphere lateralization
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increases deltoid force, and an increased thickness poly increased the deltoid force necessary for abduction. Further, Giles et al. [15] determined that humeral and glenosphere lateralization worked synergistically to decrease deltoid force. The thickness of the poly component and glenosphere lateralization also demonstrated increases in joint load [15]. In patients with rotator cuff insufficiency, adequate activation, and recruitment of the deltoid is an important factor in functional range of motion. Berliner et al. [2] stated that the role of the deltoid changes to accommodate functionality of the shoulder. In a healthy shoulder, the anterior deltoid acts primarily as a flexor, the middle deltoid acts primarily as an abductor, and the posterior deltoid acts primarily as an extensor. Whereas following the RTSA, each division of the deltoid acts primarily as an abductor [2]. Berliner et al. [2] concluded that maintenance of the shoulder girdle musculature intra- and post-operatively is crucial in order to antagonize the shear forces created by the deltoid.
6.
Patient demographics
Westermann et al. [4] conducted a study evaluating the varying demographics between traditional anatomic total shoulder arthroplasty (TSA), RTSA, and hemiarthroplasty (HA). In 2011, the mean age of patients undergoing a TSA or HA, approximately 67 years, was significantly younger than those receiving the RTSA, approximately 73 years. Further, Westermann and colleagues found that the use of HA decreased by 12.5% between 2002 and 2011. Additionally, the indications for each procedure varied, as TSA was more commonly utilized in patients with the primary diagnosis of osteoarthritis and HA was used more often in patients with a proximal humeral fracture [4]. Whereas, the RTSA was the treatment in patients with a primary diagnosis of partial or massive rotator cuff tears [4]. Padegimas et al. [16] examined the issues presented when patients younger than 55 years required treatment of severe shoulder pathology and rotator cuff insufficiency. Treatment of younger patients presents a greater challenge due to an increased life expectancy, activity level, and lifestyle [14,16]. Moreover, long-term implant success rate is a concern in younger patients; thus, putting younger patients at a higher risk for revision in the long term. However, Ek et al. [14] found that RTSA produced excellent results in no less than 10 years, despite the unforeseen obstacles in the cohort. The demand for shoulder arthroplasty is projected to increase among the younger populations; however, the greatest increase is expected in the older population [16].
7.
Patient return to activity
Garcia et al. [17] conducted a study to evaluate patients’ return to activity following RTSA. On average, patients returned to sporting activities in approximately 5 months with 85.5% of patients resuming at least one sporting activity. This result is comparable to the rate of return to sporting activity following TSA [17]. The results also demonstrated that fitness sports, swimming, and running had the highest
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rate of return. Importantly, age was a significant predictor of return, with an age at or above 70 correlating to a reduced return rate [17].
8.
Case presentation
The following is a case presentation that represents the a commonly used protocol for a RTSA.
8.1.
Patient
A 69-year-old male patient presents with left shoulder pain and limited range of motion [18]. He is right hand dominant and an avid outdoorsman. In 1964, while in the United States Air Force, he sustained an injury to the left shoulder after falling off of a B-58 bomber wing; which was repaired with two screws that were removed 6 months later. In 1995, after living with limited range of motion, his collar bone was shortened. Then in 1999, he suffered a biceps muscle rupture that was managed nonoperatively. Plain radiographs revealed proximal humeral migration and femoralization of the humeral head underneath the acromion, all consistent with rotator cuff insufficiency. The axillary view showed asymmetric wear pattern with the humeral head centered in the glenoid. Furthermore, on MRI, proximal humeral migration and a large retracted rotator cuff tear of the supraspinatus tendon all the way to the level of the glenoid, was observed. The subscapularis and infraspinatus were intact with some fatty infiltration, while the fatty infiltration of the supraspinatus alluded to the chronic nature of the rotator cuff insufficiency.
8.2.
Surgical approach
Pre-operatively, the patient was given an interscalene block. In some cases, patients may be paralyzed intraoperatively to augment glenoid exposure. Generally, patients are positioned at 25–301 of incline. A standard deltopectoral approach was used utilizing some of the patient’s previous scars.
8.3.
Humeral head preparation
Caution was taken to avoid damage to the cephalic vein, by mobilizing it medially with the pectoralis major, and the musculocutaneous nerve was protected using small Richardson retractors. No biceps tendon was identified, consistent with the patient’s history. A peel technique was employed to release the subscapularis off the lesser tuberosity. Sutures were used to tag the superior and inferior edges of the subscapularis and provide traction. The anterior circumflex vessels were ligated. A pointed Hohmann retractor was used to protect the neurovascular structures while dislocating the humeral head. The characteristic “bald head” of the humerus was clearly observed, further confirming the chronicity of the rotator cuff tear (Fig. 1). The humeral cut was made along the anatomic neck, consistent with the patient’s anatomic version. Inferior, superior, and medial borders were defined with retractors to avoid injury to the posterior rotator cuff.
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Fig. 1 – Retractor definition of boarders in preparation for the anatomical humeral neck cut. Demonstration of the characteristic "bald head" [18]. The humeral surface is sized and broached for a neck angle inclination of 1351, also limiting the risk of scapular notching when compared with a component that sits at 1551 angle [18]. Unique to each patient is the offset of the humeral head in relation to the humeral diaphysis. Most patients have a posterior offset of the humeral head. So an implant that recreates this posterior offset position is chosen. The Arthrex reverse shoulder system (Arthrex, Inc., Naples, FL, 2015), used in this case, is a totally cement-less system. Erickson et al. [19] concluded that an inclination of 1351 had a reduced rate of scapular notching compared to a 1551 implant. Furthermore, inclination angle of 1351 decreased the minimum abduction angle in comparison to an inclination of 1551 [20]. The lateralization of the glenosphere also acts to incorporate the deltoid more and give the patient more of an anatomic appearing shoulder [18]; in addition to decreasing the minimum abduction angle and the rate of scapular notching [2,20] (Fig. 2).
8.4.
Glenoid preparation
The back of the glenoid was fully exposed and the inferior capsule was released first. The axillary nerve was palpated while the capsule was released to the 6 o’clock position and the middle glenohumeral ligament was transected. The capsule was not excised so that the tissue was maintained for the subscapular repair at the end of the case. The labrum was removed to provide excellent glenoid exposure and avoid soft tissue impingement (Fig. 3).
Fig. 2 – Demonstration of the desired angle of inclination and lateral offset of the humeral component. [18]
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Fig. 3 – Glenoid exposure following soft tissue removal and preparation. [18] A guide was used to determine the position of the baseplate while achieving slight inferior tilt of the component to help decrease the risk of notching. With regard to bone grafting for the glenoid, pre-operative imaging can be used to determine if a bone graft is necessary and required. When placing the screws, the inferior peripheral screw is drilled first, then the superior screw, and finally the central screw. The superior screw is aimed anterior to avoid penetration into the suprascapular notch and a potential injury to the suprascapular nerve. Additionally, posterior placement of the screw may create a stress riser in the scapular spine, increasing the risk of fracture. The inferior screw is seated first to pull the baseplate into an inferior position, followed by the central and superior screw. A central screw depth gage is used to assess if the central screw is engaged deep enough to allow the Morse Taper of the glenosphere to be fully seated. The surgeon operating on this patient has completed approximately 350 RTSAs using the Arthrex reverse system (Arthrex, Inc., Naples, FL, 2015) without any baseplate failures or glenosphere dissociations [18]. The glenoid implant is an Arthrex two-stage flat back with press-fit fixation, fenestrations, and hydroxyapatite on the back to aid in fixation to the patient’s native bone. The glenosphere is reduced by placing the sphere on the cut surface of the humerus, lining it up with the Morris taper hole, then internally rotating the arm to snap the glenosphere into the baseplate. After impaction, a “glenosphere-checker” is used to verify the engagement of the sphere to the baseplate.
8.5.
Closing surgical remarks
As previously stated, the Arthrex reverse shoulder system (Arthrex, Inc., Naples, FL, 2015) is totally cement-less, which clearly eliminates the use of antibiotic cement, although cemented options are available. However, even in the use of approximately 66 RTSA cases that were completed for fractures, the infection rate was zero percent [18]. Spacer components may be used to build up the stability on the humeral side of the system and the Arthrex system is a “screw-in fixation” that allows the screw to lock down without rotating the implant, signifying very good humeral fixation [18]. Finally, the outcomes and stability of the shoulder following an RTSA seem to depend on the choice of implant [18]. Refer to the Table for a comprehensive list of tools and implants utilized during RTSA.
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Table – Preferential Tools and Implants Utilized During the RTSA [18,21] Tool, Implant
Rationale
Humeral stem 1351, 1551
1351 is used in majority of cases, this angle aids in range of motion; 1551 is used when patient stability is a concern Largely depends on the patient anatomy Standard is most commonly employed; Constrained is only used when patient stability is a concern or if the patient is walker, cane, or wheelchair dependent Lateralized to help shift the patient’s humerus away from the glenoid and prevent notching Determine the placement and depth of the central screw Reaming for the central screw; Prepare the glenoid Ream the entire circumference of the glenoid in preparation for baseplate placement; size determined by the size of the glenoid Impact the baseplate onto the prepared glenoid surface Achievement of the desired trajectory and depth of the inferior and superior screws; screws may be placed and seated Aid in placement, seating, and engagement of the central screw Confirm that the central screw is appropriately seated within the baseplate hole Longer shaft allows distance from the glenoid Aids in verifying that the glenosphere will completely seat and engage Preparation of the humeral canal for broaching and implantation; T-Handle Achievement of proper broach sizes and version in the humeral canal
Humeral cups Humeral polyethylene liners Glenosphere 2.8-mm Glenoid guide wire Primary post reamer Final reamer Baseplate impactor Peripheral screw drill guide, inferior/ superior bushing Central screw tap Central Screw Depth Gauge T15 Torx Driver (long) Coring reamer Humeral IM reamer (6 mm) Humeral broach alignment guide, broach handle Humeral broaches Humeral cup reamer Humeral trial cup Trial humeral liner European glenosphere Inserter Glenosphere impactor Glenosphere forceps Pointed impactor Extractors Humeral spacers Revision humeral stems
9.
Sizes 6–13; Placement of the stem into the humeral cut Confirm accurate fit of the humeral cup into the stem Match correct sizing prior to placing final implant Test fit in the actual implant to give the most exact fit Insertion of the glenosphere onto the glenoid baseplate Guarantee proper security and engagement of the Morse Taper Corroborate the validity of the Morse Taper connection Used in seating the humeral cup into the stem For the glenoid baseplate and humeral stem/ cup, only when performing a revision procedure Only used when a greater space must be filled Extended stem length allows for passage beyond humeral fracture sites
Results
For post-operative rehabilitation, the patient was placed into an abducted sling, in which the abduction component was removed on post-operative day 1. Then, the sling was no longer required and used only for comfort. The patient was advised to avoid movements that included extension, crossbody adduction, and direct abduction. The patient started physical therapy and received home therapy exercises prior to being discharged. Post-operative imaging verified appropriate alignment of the implants.
Conclusion RTSA is an effective treatment for patients with rotator cuff tear arthropathy, whereas the traditional anatomic total shoulder arthroplasty is often not an option for these patients given their cuff deficiency. The geometry of the implant components plays a major role in the success of the implant and the patient outcomes. Also, RTSA may be an appropriate option for patients undergoing revision shoulder arthroplasty. Conversely, RTSA presents several complications, most commonly including infection, dislocation, and scapular notching. Despite the risk of complications, patients
experience an improvement in pain and functional range of motion overall.
Disclosure Sydney C. Cryder, BS has no conflicts of interest to declare. Brian S. Cohen, MD: Arthrex Consultant, Royalties received, but none on Arthrex Univers Revers implants
refere nces
[1] Drake GN, O’Connor DP, Edwards TB. Indications for reverse total shoulder arthroplasty in rotator cuff disease. Clinical orthopaedics and related research 2010;468:1526–33. [2] Berliner JL, Regalado-Magdos A, Ma CB, Feeley BT. Biomechanics of reverse total shoulder arthroplasty. Journal of shoulder and elbow surgery/American Shoulder and Elbow Surgeons ... [et al.] 2015;24:150–60. [3] Nam D, Kepler CK, Neviaser AS, et al. Reverse total shoulder arthroplasty: current concepts, results, and component wear analysis. The Journal of bone and joint surgery. American volume 2010;92(Suppl 2):23–35. [4] Westermann RW, Pugely AJ, Martin CT, Gao Y, Wolf BR, Hettrich CM. Reverse shoulder arthroplasty in the United States: a comparison of national volume, patient demographics, complications, and surgical indications. The Iowa orthopaedic journal 2015;35:1–7.
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[5] Wiater BP, Baker EA, Salisbury MR, et al. Elucidating trends in revision reverse total shoulder arthroplasty procedures: a retrieval study evaluating clinical, radiographic, and functional outcomes data. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 2015;23:1–11. [6] Gerber BS, Brodsky IG, Lawless KA, et al. Implementation and evaluation of a low-literacy diabetes education computer multimedia application. Diabetes care 2005;28:1574–80. [7] Dilisio MF, Miller LR, Siegel EJ, Higgins LD. Conversion to reverse shoulder arthroplasty: humeral stem retention versus revision. Orthopedics 2015;38:e773–9. [8] Wierks C, Skolasky RL, Ji JH, McFarland EG. Reverse total shoulder replacement: intraoperative and early postoperative complications. Clinical orthopaedics and related research 2009;467:225–34. [9] Zhou HS, Chung JS, Yi PH, Li X, Price MD. Management of complications after reverse shoulder arthroplasty. Current reviews in musculoskeletal medicine 2015;8:92–7. [10] Jarrett CD, Brown BT, Schmidt CC. Reverse shoulder arthroplasty. The Orthopedic clinics of North America 2013;44 (3):389–408 x. [11] Wall B, Nove-Josserand L, O’Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. The Journal of bone and joint surgery. American volume 2007;89:1476–85. [12] Roy JS, Macdermid JC, Goel D, Faber KJ, Athwal GS, Drosdowech DS. What is a successful outcome following reverse total shoulder arthroplasty? The open orthopaedics journal 2010;4:157–63. [13] Cheung E, Willis M, Walker M, Clark R, Frankle MA. Complications in reverse total shoulder arthroplasty. The Journal of the American Academy of Orthopaedic Surgeons 2011;19:439–49.
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[14] Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. 2013;22:1199–208. [15] Giles JW, Langohr GD, Johnson JA, Athwal GS. Implant design variations in reverse total shoulder arthroplasty influence the required deltoid force and resultant joint load. Clinical orthopaedics and related research 2015;473:3615–26. [16] Padegimas EM, Maltenfort M, Lazarus MD, Ramsey ML, Williams GR, Namdari S. Future patient demand for shoulder arthroplasty by younger patients: national projections. Clinical orthopaedics and related research 2015;473:1860–7. [17] Garcia GH, Taylor SA, DePalma BJ, et al. Patient activity levels after reverse total shoulder arthroplasty: what are patients doing? The American journal of sports medicine 2015;43: 2816–21. [18] Reverse Shoulder Arthroplasty. Cleveland, OH: Current Concepts Institute; 2015. [19] Erickson BJ, Frank RM, Harris JD, Mall N, Romeo AA. The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 2015;24:988–93. [20] North LR, Hetzler MA, Pickell M, Bryant JT, Deluzio KJ, Bicknell RT. Effect of implant geometry on range of motion in reverse shoulder arthroplasty assessed using glenohumeral separation distance. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. 2015;24:1359–66. [21] Univers Revers Surgical Technique. Naples, FL: Arthrex, Inc; 2014;2014.