J Shoulder Elbow Surg (2015) 24, e50-e55
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Bilateral scapular fractures after reverse shoulder arthroplasties Christopher G. Stevens, MDa, Mark R. Murphy, BSb, Taylor D. Stevensc, Tony L. Bryant, MDd, Thomas W. Wright, MDd,* a
Tucson Orthopaedic Institute, Tucson, AZ, USA Midwestern University, Arizona College of Osteopathic Medicine, Glendale, AZ, USA c University of Arizona, Tucson, AZ, USA d Department of Orthopaedics & Rehabilitation, University of Florida, Gainesville, FL, USA b
Scapular fractures are a well-recognized complication after reverse shoulder arthroplasty (RSA).2-6,8,10,11,13,15, 16,19,27,28,30 Varying theories as to the etiology of these fractures exist, and the natural history of the operative and nonoperative treatment of these fractures has not yet been fully elucidated. Although many authors have recognized and reported on this complication unilaterally, to our knowledge no one has reported on this complication occurring bilaterally and examined its functional consequence.
Case report A 63-year-old right-hand dominant woman with a history of failed rotator cuff repair on the right shoulder underwent an RSA with a Delta III prosthesis (DePuy, Warsaw, IN, USA) for the diagnosis of rotator cuff tear arthropathy. Her preoperative active range of motion (AROM) was 70 in forward elevation (FE), 65 in external rotation (ER), and to the fifth lumbar vertebra in internal rotation (IR). Preoperative outcome measures were as follows: American
IRB information: University of Florida Authorization to Use or Disclose De-identified Health Information for Publication and Educational Services has been obtained. C.G. Stevens MD and T.D. Stevens are brothers. *Reprint requests: Thomas W. Wright, MD, 3450 Hull Road, 3rd Floor, Gainesville, FL 32608, USA. E-mail address: [email protected] (T.W. Wright).
Shoulder and Elbow Surgeons (ASES) score, 40; Constant score, 29; Shoulder Pain and Disability Index, 88; University of California–Los Angeles score,12; Simple Shoulder Test score, 1; and 12-Item Short Form Health Survey, 30. Medications pertinent to the planned procedure were ibandronate, atenolol, and clopidogrel. Details of the operation include wafer osteotomy of the subscapularis and repair, placement of the humeral stem in 10 of retroversion, and use of a DePuy Delta III prosthesis. Figure 1 represents the radiographs taken at the first postoperative visit (2 weeks). At the 6-month visit, the patient’s AROM was 140 in FE, 40 in ER, and to the second lumbar vertebra in IR. At 10.5 months postoperatively, the patient returned with increasing pain and declining function without a traumatic event. Her AROM had decreased to FE of 40 , ER to 10 , and IR to the posterior superior iliac spine. Physical examination revealed significant tenderness along the acromial angle, and radiographs showed increased acromial tilt and a fracture at the base of the acromion. A computed tomography (CT) scan was ordered to further characterize the fracture (Fig. 2). At this time, the patient was treated conservatively and placed in an abduction sling. At approximately 22 months postoperatively, she was diagnosed with rheumatoid arthritis and prescribed daily prednisone (5 mg orally 4 times a day). Her right shoulder had not regained motion; however, because of pain and difficulty in sleeping and other activities of daily living (ADLs), the patient wished to be evaluated for an RSA on her left side. She was extensively counseled about the
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Scapular fractures after reverse shoulder arthroplasties
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Figure 1 (A and B) The Grashey (true anteroposterior) and axillary lateral views of the right shoulder at the 2-week postoperative clinic visit. The prosthesis is a DePuy Delta III and is cemented.
Figure 2
Axial cut of the CT scan at the level of the fracture.
concerns in patients with bilateral RSAs, especially given her minimally functional right side with the acromial base fracture. At approximately 27 months after the initial arthroplasty, the patient elected to undergo RSA on the left side. Medications pertinent to the planned procedure were ibandronate, atenolol, clopidogrel, and prednisone. The humerus was cut in 15 of retroversion, and an Equinoxe prosthesis (Exactech, Gainesville, FL, USA) was used. Figure 3 represents the postoperative radiographs obtained 2 weeks after the procedure on the left. The patient’s preoperative AROM on the left was FE to 45 and ER to 30 ; IR and outcome measures were not obtained. The patient did well in the perioperative period, with AROM of FE to 140 and ER to 45 . At approximately 3.5 years postoperatively on the left, the patient was getting up from a seated position when she felt a ‘‘pop’’ in her left shoulder that was followed by extreme
pain. Evaluation at that time revealed point tenderness along the left scapular spine and AROM values of 30 in FE, 45 in ER, and IR to the greater trochanter. Imaging revealed an obliquely oriented, minimally displaced fracture of the scapular spine. Given that the patient had relatively poor function on the right side after a similar fracture, the patient was once again presented her options with a strong recommendation for surgical fixation of the fracture. Once again, the patient declined surgery, and conservative treatment was undertaken. She was evaluated 6 months later with radiographs and a CT scan (Fig. 4) and again declined any intervention. At the most recent follow-up (6 years on the right and 4 years on the left), the patient continued to have difficulty with overhead activities and pain. Her range of motion and outcome measures were obtained at that time and are summarized in Table I. Radiographs at the most recent follow-up (6 years on the right, 4 years on the left) are represented in Figure 5.
Discussion Stress fractures of the acromion are uncommon in the setting of a nonarthroplasty shoulder, but select case reports can be found throughout the literature.7,9,12,21-23,29 However, the incidence of scapular fractures after RSA has been reported to be between 0.8% and 10.2%.3-6,8,10,11,13-16,19,26-28,30 Given the relatively low incidence of bilateral RSAs being performed, only a single case report exists in the literature that discusses bilateral atraumatic scapular spine fractures after RSA.17 This report focused on the radiographic presentation and diagnosis of this type of lesion rather than quantifying the motion loss in FE or examining the decline in functional outcome measures after such fractures. However, the case report did mention that the ‘‘function was never regained in either shoulder, with the
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C.G. Stevens et al.
Figure 3 (A and B) The Grashey and axillary postoperative radiographs of the left side obtained at 2 weeks after the procedure. The prosthesis is an Exactech Equinoxe and is uncemented.
Figure 4 Axial cut from the CT scan confirming fracture orientation and a hypertrophic delayed union.
patient struggling to maintain daily activities.’’17 Our case is similar; however, we were able to quantify the motion loss and decline in functional outcomes and to provide insight into the natural history of this entity at mediumterm follow-up (48 months for the most recent shoulder). Risk factors for the development of this type of fracture have been examined in the literature. Otto et al18 examined a cohort of 53 scapular fractures after RSA and found that osteoporosis was a significant risk factor (P ¼ .49), whereas osteopenia, endocrine disease, autoimmune disease, excessive alcohol intake, smoking, and corticosteroid use were not significant risk factors. Of particular interest is that our patient had many of the potential risk factors identified and had been taking ibandronate for osteopenia (T-score of 1.3 in the right femoral neck in 2006) for a number of years. Although none of these demographics were found by Otto et al18 to be significant risk factors for
the development of scapular fractures after RSA, it seems reasonable that each could be identified as one in a study of sufficient power, given the known deleterious effects of these disease states and medications on bone density. Other potential causes for the development of scapular spine and acromial fractures include overtensioning of the deltoid and iatrogenic placement of a stress riser in the form of a posterosuperior screw. Hamid et al10 reported that ‘‘an increase in passive tension of the deltoid on the acromion can lead to fatigue, stress, or complete fracture,’’ and Matsen et al16 stated that scapular fractures after RSA were due to preexisting lesions, deltoid overtensioning, and fatigue fracturing through osteopenic bone. This seems especially plausible given the recent report of a stress fracture of the clavicle after RSA that occurred at the leading edge of the origin of the anterior deltoid.1 The idea of the posterosuperior screw originating from the baseplate as an iatrogenic cause of fracture was first introduced by Crosby et al5 when they discovered that in 3 of their 4 patients with scapular spine fractures after RSA, the fracture appeared to propagate from the screw tip of the posterosuperior screw. Otto et al18 also found an association with scapular spine fractures originating from the baseplate screws. In their series of 16 scapular spine fractures after RSA, 88% were in association with a screw, and 50% of these appeared to be in association with a long posterosuperior screw. Evaluation of the CT scan in our patient revealed that the fracture on the left (scapular spine) did appear to be associated with the posterosuperior screw, whereas the acromial base fracture on the right did not appear to be associated with the prosthesis/hardware. This particular complication has led some authors to recommend against the use of posterosuperior screws in the baseplate.5 Despite some authors cautioning against performing bilateral RSAs because this could lead to significant functional consequences associated with a lack of IR, we have
Scapular fractures after reverse shoulder arthroplasties Table I
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Range of motion and functional outcomes before and after acromion fracture
RSA shoulder
Right Before fracture (6 months postoperatively) Most recent follow-up (48 months after fracture) Difference Left Before fracture (36 months postoperatively) Most recent follow-up (6 months after fracture) Difference Mean decrease
Forward elevation (degrees)
Constant (0-100)
ASES (0-100)
SPADI (0-130)
UCLA (0-35)
SST (0-12)
SF-12 (0-100)
140 37 103
52 32 20
68 50 18
19 62 43
29 13 16
9 4 5
36 29 7
140 55 85 94
57 31 26 23
52 42 10 14
49 68 19 31
29 13 16 16
7 3 4 4.5
31 29 2 4.5
ASES, American Shoulder and Elbow Surgeons; SPADI, Shoulder Pain and Disability Index; UCLA, University of California–Los Angeles; SST, Simple Shoulder Test; SF-12, 12-Item Short Form Health Survey.
Figure 5 True anteroposterior radiographs of each shoulder at the most recent follow-up (6 years on the right, 4 years on the left). (A) Note the diastasis at the nonunion site as well as the decrease of the acromiohumeral interval and increased acromial tilt. (B) There is notching to the level of the inferior screw (Sirveaux grade 2), and a hypertrophic nonunion is still present. Again, there is increased acromial tilt and decreased acromiohumeral distance.
previously reported on a series of 15 patients with bilateral RSAs, all of whom were able to perform the necessary ADLs for hygiene (perineal care) after bilateral RSAs.24,25 Interestingly, this patient was still able to perform the necessary hygienic ADLs, despite the increase in pain, decrease in functional outcome measures, and bilateral delayed union and nonunion of the scapula. In the patient presented here, significant decline in both range of motion and functional outcome measures was present after the fractures occurred, and these results persisted through the most recent follow-up. The patient’s FE on the right decreased from 140 at 6 months after the operation to 37 at the most recent follow-up; on the left, the FE decreased from 140 at 36 months postoperatively to 55 at the most recent follow-up. Concomitantly, the patient’s functional outcome scores also declined, with the ASES dropping by a mean of 14 points compared with the prefracture scores; other outcome measures also showed
similar decline and are illustrated in Table I. This loss in FE and functional measures with nonoperative treatment has been noted by other authors as well. Teusink et al26 noted that with nonoperative management of these fractures, patients had 50 less FE and ASES scores that were 16.2 points lower compared with their peers that did not have a postoperative fracture; Levy et al14 and Hattrup11 reaffirmed this notion, reporting ASES values of 44 and 47.9 after scapular fracture, respectively. In Hattrup’s series, the patients with a fracture were compared with those who underwent RSA without a fracture, and the difference in ASES scores was 39.8.11 Despite their being a well-recognized consequence of RSA, the optimal management of scapular spine and acromial fractures after RSA is still being elucidated. The development of nonunion is high with conservative treatment, with rates reported between 44% and 89%, which may be in part due to the large inherent stresses and
e54 distraction placed across the fracture site by the tensioned deltoid.10,20 Although patients still show improvement in functional outcomes compared with their preoperative values with nonoperative treatment, their results are inferior to those of their nonfracture peers.10,11,26 The reported results of surgical intervention for these types of fractures have been unpredictable. Some authors report failure of tension band–type constructs, some report poor outcomes and loss of FE (40 ) after dual plating, and still others report restoration of FE and outcome measures (FE, 160 ; Constant score, 69; shortened Disabilities of the Arm, Shoulder, and Hand questionnaire, 29.5) to those of nonfracture RSA patients with dual plate/screw constructs.20,27,28 Given their success with dual plating of an acromial base fracture, Rouleau and Gaudelli20 recommended against the use of tension band–type constructs for these types of fractures, stating that the tension band was inadequate to neutralize the forces because the pull of the deltoid was in a different direction from the line of fixation. Walch et al28 have also recognized the difficulty with treating these fractures, reporting failure of osteosynthesis with a tension band–type construct used for fixation of a scapular spine fracture that subsequently needed hardware removal; still, even with this failure, they recognized the potential importance of fixation, stating that ‘‘it would seem reasonable to recommend immediate operative fixation with a plate and screw construct to avoid nonunion and excessive acromial tilt.’’ The patient presented here declined fixation of her fractures and subsequently went on to develop bilateral nonunions with increased inferior tilting of the acromion and decreasing acromiohumeral distance (Fig. 5) as well as significant decline in her functional outcome measures (Table I).
Conclusion Acromial and scapular spine fractures are a well-known complication of RSA. This case highlights some of the features of the natural history of these fractures, including the high incidence of nonunion and the negative effect they have on functional outcomes and range of motion. Risk factors for the development of fracture are still being elucidated but appear to be related to age and bone quality. Given the difficulties with ADLs that patients with bilateral RSAs inherently face, special consideration and counseling should be given to patients with risk factors to inform them of this potential complication and the natural history of nonoperative treatment. Further study needs to be performed to determine if operative fixation is a reasonable option to alter the natural history and to restore AROM and functional scores to those of patients without this complication.
C.G. Stevens et al.
Disclaimer Thomas W. Wright is a paid consultant for Exactech and receives royalties from Exactech. All the other authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.
References 1. Anakwenze OA, Pifer MA, Singh A. Clavicle stress fracture after reverse shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:e170-2. http://dx.doi.org/10.1016/j.jse.2014.03.015 2. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: the Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg 2006;15:527-40. http://dx.doi.org/10.1016/j.jse.2006.01.003 3. Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg 2005;14:147S-61S. http://dx.doi.org/10.1016/j.jse.2004.10.006 4. Bufquin T, Hersan A, Hubert L, Massin P. Reverse shoulder arthroplasty for the treatment of three- and four-part fractures of the proximal humerus in the elderly: a prospective review of 43 cases with a short-term follow-up. J Bone Joint Surg Br 2007;89:516-20. http:// dx.doi.org/10.1302/0301-620X.89B4.18435 5. Crosby LA, Hamilton A, Twiss T. Scapula fractures after reverse total shoulder arthroplasty: classification and treatment. Clin Orthop 2011; 469:2544-9. http://dx.doi.org/10.1007/s11999-011-1881-3 6. Cuff D, Pupello D, Virani N, Levy J, Frankle M. Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency. J Bone Joint Surg Am 2008;90:1244-51. http://dx.doi.org/10.2106/JBJS.G.00775 7. Dennis DA, Ferlic DC, Clayton ML. Acromial stress fractures associated with cuff-tear arthropathy. A report of three cases. J Bone Joint Surg Am 1986;68:937-40. 8. Frankle M, Siegal S, Pupello D, Saleem A, Mighell M, Vasey M. The Reverse Shoulder Prosthesis for glenohumeral arthritis associated with severe rotator cuff deficiency. A minimum two-year follow-up study of sixty patients. J Bone Joint Surg Am 2005;87:1697-705. http://dx.doi. org/10.2106/JBJS.D.02813 9. Hall RJ, Calvert PT. Stress fracture of the acromion: an unusual mechanism and review of the literature. J Bone Joint Surg Br 1995;77: 153-4. 10. Hamid N, Connor PM, Fleischli JF, D’Alessandro DF. Acromial fracture after reverse shoulder arthroplasty. Am J Orthop (Belle Mead NJ) 2011;40:E125-9. 11. Hattrup SJ. The influence of postoperative acromial and scapular spine fractures on the results of reverse shoulder arthroplasty. Orthopedics 2010;33:302. http://dx.doi.org/10.3928/01477447-20100329-04 12. Ho KM, Schranz P, Wallace WA. ‘‘Stress’’ fracture of the scapula. Injury 1993;24:498. 13. Kim SH, Wise BL, Zhang Y, Szabo RM. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am 2011; 93:2249-54. http://dx.doi.org/10.2106/JBJS.J.01994 14. Levy JC, Anderson C, Samson A. Classification of postoperative acromial fractures following reverse shoulder arthroplasty. J Bone Joint Surg Am 2013;95:e104. http://dx.doi.org/10.2106/JBJS.K.01516 15. Levy JC, Blum S. Postoperative acromion base fracture resulting in subsequent instability of reverse shoulder replacement. J Shoulder Elbow Surg 2012;21:e14-8. http://dx.doi.org/10.1016/j. jse.2011.09.018
Scapular fractures after reverse shoulder arthroplasties 16. Matsen FA 3rd, Boileau P, Walch G, Gerber C, Bicknell RT. The reverse total shoulder arthroplasty. J Bone Joint Surg Am 2007;89: 660-7. 17. Nicolay S, De Beuckeleer L, Stoffelen D, Vanhoenacker F, Pouillon M. Atraumatic bilateral scapular spine fracture several months after bilateral reverse total shoulder arthroplasty. Skeletal Radiol 2014;43:699-702. http://dx.doi.org/10.1007/s00256-0131775-4 18. Otto RJ, Virani NA, Levy JC, Nigro PT, Cuff DJ, Frankle MA. Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification. J Shoulder Elbow Surg 2013;22:1514-21. http://dx.doi.org/10.1016/ j.jse.2013.02.007 19. 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. 20. Rouleau DM, Gaudelli C. Successful treatment of fractures of the base of the acromion after reverse shoulder arthroplasty: case report and review of the literature. Int J Shoulder Surg 2013;7:149-52. http://dx. doi.org/10.4103/0973-6042.123531 21. Roy N, Smith MG, Jacobs LGH. Stress fracture of base of the acromion. Ann Rheum Dis 2002;61:944-5. http://dx.doi.org/10.1136/ard. 61.10.944 22. Rupp S, Seil R, Kohn DM. Surgical reconstruction of a stress fracture of the acromion after arthroscopic subacromial decompression in an elite tennis player. Arthroscopy 1998;14:106-8.
e55 23. Schils JP, Freed HA, Richmond BJ, Piraino DW, Bergfeld JA, Belhobek GH. Stress fracture of the acromion. AJR Am J Roentgenol 1990;155:1140-1. 24. Sirveaux F, Mole D. Failures of the reverse prosthesis: identifying the problems. In: Cofield RH, Sperling JW, editors. Revision and complex shoulder arthroplasty. Philadelphia: Lippincott Williams & Wilkins; 2010. p. 18-28 (ISBN No. 078177747X). 25. Stevens CG, Struk AM, Wright TW. The functional impact of bilateral reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2014;23: 1341-8. http://dx.doi.org/10.1016/j.jse.2013.12.012 26. Teusink MJ, Otto RJ, Cottrell BJ, Frankle MA. What is the effect of postoperative scapular fracture on outcomes of reverse shoulder arthroplasty? J Shoulder Elbow Surg 2013;23:782-90. http://dx.doi. org/10.1016/j.jse.2013.09.010 27. Wahlquist TC, Hunt AF, Braman JP. Acromial base fractures after reverse total shoulder arthroplasty: report of five cases. J Shoulder Elbow Surg 2011;20:1178-83. http://dx.doi.org/10.1016/j.jse.2011.01.029 28. Walch G, Mottier F, Wall B, Boileau P, Mole D, Favard L. Acromial insufficiency in reverse shoulder arthroplasties. J Shoulder Elbow Surg 2009;18:495-502. http://dx.doi.org/10.1016/j.jse.2008.12.002 29. Ward WG, Bergfeld JA, Carson WG Jr. Stress fracture of the base of the acromial process. Am J Sports Med 1994;22:146-7. 30. Werner CML, 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
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Bilateral scapular fractures after reverse shoulder arthroplasties Christopher G. Stevens, MDa, Mark R. Murphy, BSb, Taylor D. Stevensc, Tony L. Bryant, MDd, Thomas W. Wright, MDd,* a
Tucson Orthopaedic Institute, Tucson, AZ, USA Midwestern University, Arizona College of Osteopathic Medicine, Glendale, AZ, USA c University of Arizona, Tucson, AZ, USA d Department of Orthopaedics & Rehabilitation, University of Florida, Gainesville, FL, USA b
Scapular fractures are a well-recognized complication after reverse shoulder arthroplasty (RSA).2-6,8,10,11,13,15, 16,19,27,28,30 Varying theories as to the etiology of these fractures exist, and the natural history of the operative and nonoperative treatment of these fractures has not yet been fully elucidated. Although many authors have recognized and reported on this complication unilaterally, to our knowledge no one has reported on this complication occurring bilaterally and examined its functional consequence.
Case report A 63-year-old right-hand dominant woman with a history of failed rotator cuff repair on the right shoulder underwent an RSA with a Delta III prosthesis (DePuy, Warsaw, IN, USA) for the diagnosis of rotator cuff tear arthropathy. Her preoperative active range of motion (AROM) was 70 in forward elevation (FE), 65 in external rotation (ER), and to the fifth lumbar vertebra in internal rotation (IR). Preoperative outcome measures were as follows: American
IRB information: University of Florida Authorization to Use or Disclose De-identified Health Information for Publication and Educational Services has been obtained. C.G. Stevens MD and T.D. Stevens are brothers. *Reprint requests: Thomas W. Wright, MD, 3450 Hull Road, 3rd Floor, Gainesville, FL 32608, USA. E-mail address: [email protected] (T.W. Wright).
Shoulder and Elbow Surgeons (ASES) score, 40; Constant score, 29; Shoulder Pain and Disability Index, 88; University of California–Los Angeles score,12; Simple Shoulder Test score, 1; and 12-Item Short Form Health Survey, 30. Medications pertinent to the planned procedure were ibandronate, atenolol, and clopidogrel. Details of the operation include wafer osteotomy of the subscapularis and repair, placement of the humeral stem in 10 of retroversion, and use of a DePuy Delta III prosthesis. Figure 1 represents the radiographs taken at the first postoperative visit (2 weeks). At the 6-month visit, the patient’s AROM was 140 in FE, 40 in ER, and to the second lumbar vertebra in IR. At 10.5 months postoperatively, the patient returned with increasing pain and declining function without a traumatic event. Her AROM had decreased to FE of 40 , ER to 10 , and IR to the posterior superior iliac spine. Physical examination revealed significant tenderness along the acromial angle, and radiographs showed increased acromial tilt and a fracture at the base of the acromion. A computed tomography (CT) scan was ordered to further characterize the fracture (Fig. 2). At this time, the patient was treated conservatively and placed in an abduction sling. At approximately 22 months postoperatively, she was diagnosed with rheumatoid arthritis and prescribed daily prednisone (5 mg orally 4 times a day). Her right shoulder had not regained motion; however, because of pain and difficulty in sleeping and other activities of daily living (ADLs), the patient wished to be evaluated for an RSA on her left side. She was extensively counseled about the
1058-2746/$ - see front matter Ó 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2014.09.045
Scapular fractures after reverse shoulder arthroplasties
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Figure 1 (A and B) The Grashey (true anteroposterior) and axillary lateral views of the right shoulder at the 2-week postoperative clinic visit. The prosthesis is a DePuy Delta III and is cemented.
Figure 2
Axial cut of the CT scan at the level of the fracture.
concerns in patients with bilateral RSAs, especially given her minimally functional right side with the acromial base fracture. At approximately 27 months after the initial arthroplasty, the patient elected to undergo RSA on the left side. Medications pertinent to the planned procedure were ibandronate, atenolol, clopidogrel, and prednisone. The humerus was cut in 15 of retroversion, and an Equinoxe prosthesis (Exactech, Gainesville, FL, USA) was used. Figure 3 represents the postoperative radiographs obtained 2 weeks after the procedure on the left. The patient’s preoperative AROM on the left was FE to 45 and ER to 30 ; IR and outcome measures were not obtained. The patient did well in the perioperative period, with AROM of FE to 140 and ER to 45 . At approximately 3.5 years postoperatively on the left, the patient was getting up from a seated position when she felt a ‘‘pop’’ in her left shoulder that was followed by extreme
pain. Evaluation at that time revealed point tenderness along the left scapular spine and AROM values of 30 in FE, 45 in ER, and IR to the greater trochanter. Imaging revealed an obliquely oriented, minimally displaced fracture of the scapular spine. Given that the patient had relatively poor function on the right side after a similar fracture, the patient was once again presented her options with a strong recommendation for surgical fixation of the fracture. Once again, the patient declined surgery, and conservative treatment was undertaken. She was evaluated 6 months later with radiographs and a CT scan (Fig. 4) and again declined any intervention. At the most recent follow-up (6 years on the right and 4 years on the left), the patient continued to have difficulty with overhead activities and pain. Her range of motion and outcome measures were obtained at that time and are summarized in Table I. Radiographs at the most recent follow-up (6 years on the right, 4 years on the left) are represented in Figure 5.
Discussion Stress fractures of the acromion are uncommon in the setting of a nonarthroplasty shoulder, but select case reports can be found throughout the literature.7,9,12,21-23,29 However, the incidence of scapular fractures after RSA has been reported to be between 0.8% and 10.2%.3-6,8,10,11,13-16,19,26-28,30 Given the relatively low incidence of bilateral RSAs being performed, only a single case report exists in the literature that discusses bilateral atraumatic scapular spine fractures after RSA.17 This report focused on the radiographic presentation and diagnosis of this type of lesion rather than quantifying the motion loss in FE or examining the decline in functional outcome measures after such fractures. However, the case report did mention that the ‘‘function was never regained in either shoulder, with the
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C.G. Stevens et al.
Figure 3 (A and B) The Grashey and axillary postoperative radiographs of the left side obtained at 2 weeks after the procedure. The prosthesis is an Exactech Equinoxe and is uncemented.
Figure 4 Axial cut from the CT scan confirming fracture orientation and a hypertrophic delayed union.
patient struggling to maintain daily activities.’’17 Our case is similar; however, we were able to quantify the motion loss and decline in functional outcomes and to provide insight into the natural history of this entity at mediumterm follow-up (48 months for the most recent shoulder). Risk factors for the development of this type of fracture have been examined in the literature. Otto et al18 examined a cohort of 53 scapular fractures after RSA and found that osteoporosis was a significant risk factor (P ¼ .49), whereas osteopenia, endocrine disease, autoimmune disease, excessive alcohol intake, smoking, and corticosteroid use were not significant risk factors. Of particular interest is that our patient had many of the potential risk factors identified and had been taking ibandronate for osteopenia (T-score of 1.3 in the right femoral neck in 2006) for a number of years. Although none of these demographics were found by Otto et al18 to be significant risk factors for
the development of scapular fractures after RSA, it seems reasonable that each could be identified as one in a study of sufficient power, given the known deleterious effects of these disease states and medications on bone density. Other potential causes for the development of scapular spine and acromial fractures include overtensioning of the deltoid and iatrogenic placement of a stress riser in the form of a posterosuperior screw. Hamid et al10 reported that ‘‘an increase in passive tension of the deltoid on the acromion can lead to fatigue, stress, or complete fracture,’’ and Matsen et al16 stated that scapular fractures after RSA were due to preexisting lesions, deltoid overtensioning, and fatigue fracturing through osteopenic bone. This seems especially plausible given the recent report of a stress fracture of the clavicle after RSA that occurred at the leading edge of the origin of the anterior deltoid.1 The idea of the posterosuperior screw originating from the baseplate as an iatrogenic cause of fracture was first introduced by Crosby et al5 when they discovered that in 3 of their 4 patients with scapular spine fractures after RSA, the fracture appeared to propagate from the screw tip of the posterosuperior screw. Otto et al18 also found an association with scapular spine fractures originating from the baseplate screws. In their series of 16 scapular spine fractures after RSA, 88% were in association with a screw, and 50% of these appeared to be in association with a long posterosuperior screw. Evaluation of the CT scan in our patient revealed that the fracture on the left (scapular spine) did appear to be associated with the posterosuperior screw, whereas the acromial base fracture on the right did not appear to be associated with the prosthesis/hardware. This particular complication has led some authors to recommend against the use of posterosuperior screws in the baseplate.5 Despite some authors cautioning against performing bilateral RSAs because this could lead to significant functional consequences associated with a lack of IR, we have
Scapular fractures after reverse shoulder arthroplasties Table I
e53
Range of motion and functional outcomes before and after acromion fracture
RSA shoulder
Right Before fracture (6 months postoperatively) Most recent follow-up (48 months after fracture) Difference Left Before fracture (36 months postoperatively) Most recent follow-up (6 months after fracture) Difference Mean decrease
Forward elevation (degrees)
Constant (0-100)
ASES (0-100)
SPADI (0-130)
UCLA (0-35)
SST (0-12)
SF-12 (0-100)
140 37 103
52 32 20
68 50 18
19 62 43
29 13 16
9 4 5
36 29 7
140 55 85 94
57 31 26 23
52 42 10 14
49 68 19 31
29 13 16 16
7 3 4 4.5
31 29 2 4.5
ASES, American Shoulder and Elbow Surgeons; SPADI, Shoulder Pain and Disability Index; UCLA, University of California–Los Angeles; SST, Simple Shoulder Test; SF-12, 12-Item Short Form Health Survey.
Figure 5 True anteroposterior radiographs of each shoulder at the most recent follow-up (6 years on the right, 4 years on the left). (A) Note the diastasis at the nonunion site as well as the decrease of the acromiohumeral interval and increased acromial tilt. (B) There is notching to the level of the inferior screw (Sirveaux grade 2), and a hypertrophic nonunion is still present. Again, there is increased acromial tilt and decreased acromiohumeral distance.
previously reported on a series of 15 patients with bilateral RSAs, all of whom were able to perform the necessary ADLs for hygiene (perineal care) after bilateral RSAs.24,25 Interestingly, this patient was still able to perform the necessary hygienic ADLs, despite the increase in pain, decrease in functional outcome measures, and bilateral delayed union and nonunion of the scapula. In the patient presented here, significant decline in both range of motion and functional outcome measures was present after the fractures occurred, and these results persisted through the most recent follow-up. The patient’s FE on the right decreased from 140 at 6 months after the operation to 37 at the most recent follow-up; on the left, the FE decreased from 140 at 36 months postoperatively to 55 at the most recent follow-up. Concomitantly, the patient’s functional outcome scores also declined, with the ASES dropping by a mean of 14 points compared with the prefracture scores; other outcome measures also showed
similar decline and are illustrated in Table I. This loss in FE and functional measures with nonoperative treatment has been noted by other authors as well. Teusink et al26 noted that with nonoperative management of these fractures, patients had 50 less FE and ASES scores that were 16.2 points lower compared with their peers that did not have a postoperative fracture; Levy et al14 and Hattrup11 reaffirmed this notion, reporting ASES values of 44 and 47.9 after scapular fracture, respectively. In Hattrup’s series, the patients with a fracture were compared with those who underwent RSA without a fracture, and the difference in ASES scores was 39.8.11 Despite their being a well-recognized consequence of RSA, the optimal management of scapular spine and acromial fractures after RSA is still being elucidated. The development of nonunion is high with conservative treatment, with rates reported between 44% and 89%, which may be in part due to the large inherent stresses and
e54 distraction placed across the fracture site by the tensioned deltoid.10,20 Although patients still show improvement in functional outcomes compared with their preoperative values with nonoperative treatment, their results are inferior to those of their nonfracture peers.10,11,26 The reported results of surgical intervention for these types of fractures have been unpredictable. Some authors report failure of tension band–type constructs, some report poor outcomes and loss of FE (40 ) after dual plating, and still others report restoration of FE and outcome measures (FE, 160 ; Constant score, 69; shortened Disabilities of the Arm, Shoulder, and Hand questionnaire, 29.5) to those of nonfracture RSA patients with dual plate/screw constructs.20,27,28 Given their success with dual plating of an acromial base fracture, Rouleau and Gaudelli20 recommended against the use of tension band–type constructs for these types of fractures, stating that the tension band was inadequate to neutralize the forces because the pull of the deltoid was in a different direction from the line of fixation. Walch et al28 have also recognized the difficulty with treating these fractures, reporting failure of osteosynthesis with a tension band–type construct used for fixation of a scapular spine fracture that subsequently needed hardware removal; still, even with this failure, they recognized the potential importance of fixation, stating that ‘‘it would seem reasonable to recommend immediate operative fixation with a plate and screw construct to avoid nonunion and excessive acromial tilt.’’ The patient presented here declined fixation of her fractures and subsequently went on to develop bilateral nonunions with increased inferior tilting of the acromion and decreasing acromiohumeral distance (Fig. 5) as well as significant decline in her functional outcome measures (Table I).
Conclusion Acromial and scapular spine fractures are a well-known complication of RSA. This case highlights some of the features of the natural history of these fractures, including the high incidence of nonunion and the negative effect they have on functional outcomes and range of motion. Risk factors for the development of fracture are still being elucidated but appear to be related to age and bone quality. Given the difficulties with ADLs that patients with bilateral RSAs inherently face, special consideration and counseling should be given to patients with risk factors to inform them of this potential complication and the natural history of nonoperative treatment. Further study needs to be performed to determine if operative fixation is a reasonable option to alter the natural history and to restore AROM and functional scores to those of patients without this complication.
C.G. Stevens et al.
Disclaimer Thomas W. Wright is a paid consultant for Exactech and receives royalties from Exactech. All the other authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.
References 1. Anakwenze OA, Pifer MA, Singh A. Clavicle stress fracture after reverse shoulder arthroplasty. J Shoulder Elbow Surg 2014;23:e170-2. http://dx.doi.org/10.1016/j.jse.2014.03.015 2. Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: the Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg 2006;15:527-40. http://dx.doi.org/10.1016/j.jse.2006.01.003 3. Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg 2005;14:147S-61S. http://dx.doi.org/10.1016/j.jse.2004.10.006 4. Bufquin T, Hersan A, Hubert L, Massin P. Reverse shoulder arthroplasty for the treatment of three- and four-part fractures of the proximal humerus in the elderly: a prospective review of 43 cases with a short-term follow-up. J Bone Joint Surg Br 2007;89:516-20. http:// dx.doi.org/10.1302/0301-620X.89B4.18435 5. Crosby LA, Hamilton A, Twiss T. Scapula fractures after reverse total shoulder arthroplasty: classification and treatment. Clin Orthop 2011; 469:2544-9. http://dx.doi.org/10.1007/s11999-011-1881-3 6. Cuff D, Pupello D, Virani N, Levy J, Frankle M. Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency. J Bone Joint Surg Am 2008;90:1244-51. http://dx.doi.org/10.2106/JBJS.G.00775 7. Dennis DA, Ferlic DC, Clayton ML. Acromial stress fractures associated with cuff-tear arthropathy. A report of three cases. J Bone Joint Surg Am 1986;68:937-40. 8. Frankle M, Siegal S, Pupello D, Saleem A, Mighell M, Vasey M. The Reverse Shoulder Prosthesis for glenohumeral arthritis associated with severe rotator cuff deficiency. A minimum two-year follow-up study of sixty patients. J Bone Joint Surg Am 2005;87:1697-705. http://dx.doi. org/10.2106/JBJS.D.02813 9. Hall RJ, Calvert PT. Stress fracture of the acromion: an unusual mechanism and review of the literature. J Bone Joint Surg Br 1995;77: 153-4. 10. Hamid N, Connor PM, Fleischli JF, D’Alessandro DF. Acromial fracture after reverse shoulder arthroplasty. Am J Orthop (Belle Mead NJ) 2011;40:E125-9. 11. Hattrup SJ. The influence of postoperative acromial and scapular spine fractures on the results of reverse shoulder arthroplasty. Orthopedics 2010;33:302. http://dx.doi.org/10.3928/01477447-20100329-04 12. Ho KM, Schranz P, Wallace WA. ‘‘Stress’’ fracture of the scapula. Injury 1993;24:498. 13. Kim SH, Wise BL, Zhang Y, Szabo RM. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am 2011; 93:2249-54. http://dx.doi.org/10.2106/JBJS.J.01994 14. Levy JC, Anderson C, Samson A. Classification of postoperative acromial fractures following reverse shoulder arthroplasty. J Bone Joint Surg Am 2013;95:e104. http://dx.doi.org/10.2106/JBJS.K.01516 15. Levy JC, Blum S. Postoperative acromion base fracture resulting in subsequent instability of reverse shoulder replacement. J Shoulder Elbow Surg 2012;21:e14-8. http://dx.doi.org/10.1016/j. jse.2011.09.018
Scapular fractures after reverse shoulder arthroplasties 16. Matsen FA 3rd, Boileau P, Walch G, Gerber C, Bicknell RT. The reverse total shoulder arthroplasty. J Bone Joint Surg Am 2007;89: 660-7. 17. Nicolay S, De Beuckeleer L, Stoffelen D, Vanhoenacker F, Pouillon M. Atraumatic bilateral scapular spine fracture several months after bilateral reverse total shoulder arthroplasty. Skeletal Radiol 2014;43:699-702. http://dx.doi.org/10.1007/s00256-0131775-4 18. Otto RJ, Virani NA, Levy JC, Nigro PT, Cuff DJ, Frankle MA. Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification. J Shoulder Elbow Surg 2013;22:1514-21. http://dx.doi.org/10.1016/ j.jse.2013.02.007 19. 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. 20. Rouleau DM, Gaudelli C. Successful treatment of fractures of the base of the acromion after reverse shoulder arthroplasty: case report and review of the literature. Int J Shoulder Surg 2013;7:149-52. http://dx. doi.org/10.4103/0973-6042.123531 21. Roy N, Smith MG, Jacobs LGH. Stress fracture of base of the acromion. Ann Rheum Dis 2002;61:944-5. http://dx.doi.org/10.1136/ard. 61.10.944 22. Rupp S, Seil R, Kohn DM. Surgical reconstruction of a stress fracture of the acromion after arthroscopic subacromial decompression in an elite tennis player. Arthroscopy 1998;14:106-8.
e55 23. Schils JP, Freed HA, Richmond BJ, Piraino DW, Bergfeld JA, Belhobek GH. Stress fracture of the acromion. AJR Am J Roentgenol 1990;155:1140-1. 24. Sirveaux F, Mole D. Failures of the reverse prosthesis: identifying the problems. In: Cofield RH, Sperling JW, editors. Revision and complex shoulder arthroplasty. Philadelphia: Lippincott Williams & Wilkins; 2010. p. 18-28 (ISBN No. 078177747X). 25. Stevens CG, Struk AM, Wright TW. The functional impact of bilateral reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2014;23: 1341-8. http://dx.doi.org/10.1016/j.jse.2013.12.012 26. Teusink MJ, Otto RJ, Cottrell BJ, Frankle MA. What is the effect of postoperative scapular fracture on outcomes of reverse shoulder arthroplasty? J Shoulder Elbow Surg 2013;23:782-90. http://dx.doi. org/10.1016/j.jse.2013.09.010 27. Wahlquist TC, Hunt AF, Braman JP. Acromial base fractures after reverse total shoulder arthroplasty: report of five cases. J Shoulder Elbow Surg 2011;20:1178-83. http://dx.doi.org/10.1016/j.jse.2011.01.029 28. Walch G, Mottier F, Wall B, Boileau P, Mole D, Favard L. Acromial insufficiency in reverse shoulder arthroplasties. J Shoulder Elbow Surg 2009;18:495-502. http://dx.doi.org/10.1016/j.jse.2008.12.002 29. Ward WG, Bergfeld JA, Carson WG Jr. Stress fracture of the base of the acromial process. Am J Sports Med 1994;22:146-7. 30. Werner CML, 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
