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Subscapularis Tenotomy: Optimal Approach to Shoulder Replacement: Affirms
Subscapularis Tenotomy: Optimal Approach to Shoulder Replacement: Affirms John W. Sperling, MD, MBA Subscapularis tenotomy is a simple, reproducible, and time-efficient method to provide secure repair of the subscapularis in shoulder arthroplasty. Comparing lesser tuberosity osteotomy with tenotomy, biomechanical research has shown no difference in maximum load, stiffness, elongation amplitude, or cyclic elongation. Clinical research has shown satisfactory results of subscapularis healing with tendon-to-tendon repair. In addition, research on the outcome of lesser tuberosity osteotomy shows concerning rates of progressive fatty infiltration of the subscapularis. Therefore, the complexity of lesser tuberosity osteotomy, in conjunction with concerns about possible nonunion and fragmentation, does not seem to warrant changing from the safe, reliable, and simple approach of subscapularis tenotomy. Semin Arthro 23:90-91 © 2012 Elsevier Inc. All rights reserved. KEYWORDS subscapularis, tenotomy, shoulder, replacement
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t is known that a strong repair of the subscapularis is imperative for motion, stability, and strength after shoulder replacement. However, there has been significant debate over the preferred technique for management of the subscapularis. Traditionally, tenotomy of the subscapularis has been performed to allow access to the glenohumeral joint to perform the shoulder arthroplasty procedure. Recently, lesser tuberosity osteotomy has been described as another option to manage the subscapularis tendon and decrease the rate of subscapularis insufficiency after shoulder arthroplasty. Little attention was directed at subscapularis integrity before the report by Miller et al1 in 2003. The authors had noticed in some of their patients, a loss of subscapularis function after total shoulder arthroplasty. The authors performed a review of 41 patients. Among these patients, 32 underwent subscapularis repair with bone tunnels, and 9 underwent anatomic subscapularis repair. The investigators reported that 25 of 37 lift-off examinations were abnormal. In addition, the belly-press examination was abnormal in 24 of 36 shoulders. Among those 25 patients with an abnormal lift-off test, the authors observed that 92% reported decreased subscapularis function (P ⬍ 0.01). Because of the high reported rate of subscapularis dysfunction, there was interest in developing alternative techniques Mayo Clinic, Rochester, MN. Address reprint requests to John W. Sperling, MD, MBA, Mayo Clinic, 200 First Street South West, Rochester, MN 55905. E-mail: sperling.john@ mayo.edu
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1045-4527/12/$-see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.sart.2012.04.002
to subscapularis tenotomy, specifically lesser tuberosity osteotomy. This in turn has generated significant debate. The purpose of this article is to discuss subscapularis tenotomy as the preferred technique.
Benefits of Subscapularis Tenotomy Subscapularis tenotomy is a simple, reproducible, and timeefficient method to provide secure repair of the subscapularis in shoulder arthroplasty. There are several potential challenges associated with lesser tuberosity osteotomy. These include increased complexity and possible crushing of the metaphyseal bone during the shoulder arthroplasty procedure. Performing a lesser tuberosity osteotomy may also result in fragmentation of the lesser tuberosity and potential nonunion.
Biomechanical Studies Van Thiel et al performed a biomechanical study comparing 3 different techniques to manage the subscapularis: tendonto-bone repair, lesser tuberosity osteotomy, and a combined technique.2 The authors used 24 paired cadaveric shoulders for testing. Examination of the specimens revealed no significant difference in bone mineral density, construct thickness, or age (P ⬎ 0.05). The authors reported no significant differ-
Subscapularis tenotomy ence in maximum load to failure, stiffness, elongation amplitude, or cyclic elongation, comparing the techniques. Giuseffi et al3 performed biomechanical testing comparing lesser tuberosity osteotomy with subscapularis tenotomy. The investigators used 20 paired upper extremities from 10 cadavers. From each cadaver, 1 shoulder underwent subscapularis tenotomy, and the contralateral shoulder underwent lesser tuberosity osteotomy. The specimens then underwent testing that included cyclic displacement and evaluation for maximum load to failure. The authors discovered that the specimens with a subscapularis tenotomy had significantly less cyclic displacement (0.8 mm) compared with those that underwent a lesser tuberosity osteotomy (1.8 mm). With regard to maximum load to failure, there was no significant difference comparing lesser tuberosity osteotomy (447 ⫾ 89 N) with subscapularis tenotomy (439 ⫾ 96 N) (P ⫽ 0.78).
Clinical Studies Caplan et al reported on 45 patients who underwent repair of the subscapularis in a tendon-to-tendon manner during the course of total shoulder arthroplasty.4 In their study, 41 of 45 patients had a negative lift-off test, and all patients had a negative belly-press test. The authors noted that tendon-totendon repair of the subscapularis is faster, simpler, and avoids the possibility of a lesser tuberosity nonunion. They also reported that the issue with postoperative subscapularis tearing is related to the postoperative rehabilitation. Specifically, the investigators noted that “inordinate stress on the repair before sufficient healing of the tendon” is the reason for subscapularis failure. Therefore, careful attention must be directed at the role of early postoperative rehabilitation to allow healing. In addition, research on the outcome of lesser tuberosity osteotomy has shown concerning rates of progressive fatty infiltration of the subscapularis. Gerber et al5 reviewed the results of 39 shoulders in 26 consecutive patients who had
91 undergone total shoulder arthroplasty using a lesser tuberosity osteotomy. The patients were studied at a mean follow-up of 39 months. In addition to standard clinical scoring, each of the shoulders underwent radiography and computed tomography to evaluate for changes in the subscapularis and lesser tuberosity healing. At the most recent follow-up, all the lesser tuberosities had healed. Clinically, 27 of 36 shoulders had a normal lift-off test, and 33 of 37 had a negative belly-press test. However, there was a 44% rate of progressive fatty infiltration of the subscapularis without a defined cause.
Conclusions The complexity of lesser tuberosity osteotomy, in conjunction with concerns about possible tuberosity nonunion, fragmentation, and fatty infiltration, as well as a lack of strong evidence of superiority, does not seem to warrant changing from the safe, reliable, and simple approach of subscapularis tenotomy. The author prefers the safe, reliable, and simple approach of subscapularis tenotomy, which has been shown to be biomechanically and clinically sound.
References 1. Miller SL, Hazrati Y, Klepps S, et al: Loss of subscapularis function after total shoulder replacement: A seldom recognized problem. J Shoulder Elbow Surg 12:29-34, 2003 2. Van Thiel GS, Wang VM, Wang FC, et al: Biomechanical similarities among subscapularis repairs after shoulder arthroplasty. J Shoulder Elbow Surg 19:657-663, 2010 3. Giuseffi SA, Wongtriratanachai P, Omae H, et al: Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2011 Oct 5 (Epub ahead of print) 4. Caplan JL, Whitfield B, Nevaiser RJ: Subscapularis function after primary tendon to tendon repair in patients after replacement arthroplasty of the shoulder. J Shoulder Elbow Surg 18:193-196, 2009 5. Gerber C, Yian EH, Pfirrmann CA, et al: Subscapularis muscle function and structure after total shoulder replacement with lesser tuberosity osteotomy and repair. J Bone Joint Surg Am 87:1739-1745, 2005
I
t is known that a strong repair of the subscapularis is imperative for motion, stability, and strength after shoulder replacement. However, there has been significant debate over the preferred technique for management of the subscapularis. Traditionally, tenotomy of the subscapularis has been performed to allow access to the glenohumeral joint to perform the shoulder arthroplasty procedure. Recently, lesser tuberosity osteotomy has been described as another option to manage the subscapularis tendon and decrease the rate of subscapularis insufficiency after shoulder arthroplasty. Little attention was directed at subscapularis integrity before the report by Miller et al1 in 2003. The authors had noticed in some of their patients, a loss of subscapularis function after total shoulder arthroplasty. The authors performed a review of 41 patients. Among these patients, 32 underwent subscapularis repair with bone tunnels, and 9 underwent anatomic subscapularis repair. The investigators reported that 25 of 37 lift-off examinations were abnormal. In addition, the belly-press examination was abnormal in 24 of 36 shoulders. Among those 25 patients with an abnormal lift-off test, the authors observed that 92% reported decreased subscapularis function (P ⬍ 0.01). Because of the high reported rate of subscapularis dysfunction, there was interest in developing alternative techniques Mayo Clinic, Rochester, MN. Address reprint requests to John W. Sperling, MD, MBA, Mayo Clinic, 200 First Street South West, Rochester, MN 55905. E-mail: sperling.john@ mayo.edu
90
1045-4527/12/$-see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.sart.2012.04.002
to subscapularis tenotomy, specifically lesser tuberosity osteotomy. This in turn has generated significant debate. The purpose of this article is to discuss subscapularis tenotomy as the preferred technique.
Benefits of Subscapularis Tenotomy Subscapularis tenotomy is a simple, reproducible, and timeefficient method to provide secure repair of the subscapularis in shoulder arthroplasty. There are several potential challenges associated with lesser tuberosity osteotomy. These include increased complexity and possible crushing of the metaphyseal bone during the shoulder arthroplasty procedure. Performing a lesser tuberosity osteotomy may also result in fragmentation of the lesser tuberosity and potential nonunion.
Biomechanical Studies Van Thiel et al performed a biomechanical study comparing 3 different techniques to manage the subscapularis: tendonto-bone repair, lesser tuberosity osteotomy, and a combined technique.2 The authors used 24 paired cadaveric shoulders for testing. Examination of the specimens revealed no significant difference in bone mineral density, construct thickness, or age (P ⬎ 0.05). The authors reported no significant differ-
Subscapularis tenotomy ence in maximum load to failure, stiffness, elongation amplitude, or cyclic elongation, comparing the techniques. Giuseffi et al3 performed biomechanical testing comparing lesser tuberosity osteotomy with subscapularis tenotomy. The investigators used 20 paired upper extremities from 10 cadavers. From each cadaver, 1 shoulder underwent subscapularis tenotomy, and the contralateral shoulder underwent lesser tuberosity osteotomy. The specimens then underwent testing that included cyclic displacement and evaluation for maximum load to failure. The authors discovered that the specimens with a subscapularis tenotomy had significantly less cyclic displacement (0.8 mm) compared with those that underwent a lesser tuberosity osteotomy (1.8 mm). With regard to maximum load to failure, there was no significant difference comparing lesser tuberosity osteotomy (447 ⫾ 89 N) with subscapularis tenotomy (439 ⫾ 96 N) (P ⫽ 0.78).
Clinical Studies Caplan et al reported on 45 patients who underwent repair of the subscapularis in a tendon-to-tendon manner during the course of total shoulder arthroplasty.4 In their study, 41 of 45 patients had a negative lift-off test, and all patients had a negative belly-press test. The authors noted that tendon-totendon repair of the subscapularis is faster, simpler, and avoids the possibility of a lesser tuberosity nonunion. They also reported that the issue with postoperative subscapularis tearing is related to the postoperative rehabilitation. Specifically, the investigators noted that “inordinate stress on the repair before sufficient healing of the tendon” is the reason for subscapularis failure. Therefore, careful attention must be directed at the role of early postoperative rehabilitation to allow healing. In addition, research on the outcome of lesser tuberosity osteotomy has shown concerning rates of progressive fatty infiltration of the subscapularis. Gerber et al5 reviewed the results of 39 shoulders in 26 consecutive patients who had
91 undergone total shoulder arthroplasty using a lesser tuberosity osteotomy. The patients were studied at a mean follow-up of 39 months. In addition to standard clinical scoring, each of the shoulders underwent radiography and computed tomography to evaluate for changes in the subscapularis and lesser tuberosity healing. At the most recent follow-up, all the lesser tuberosities had healed. Clinically, 27 of 36 shoulders had a normal lift-off test, and 33 of 37 had a negative belly-press test. However, there was a 44% rate of progressive fatty infiltration of the subscapularis without a defined cause.
Conclusions The complexity of lesser tuberosity osteotomy, in conjunction with concerns about possible tuberosity nonunion, fragmentation, and fatty infiltration, as well as a lack of strong evidence of superiority, does not seem to warrant changing from the safe, reliable, and simple approach of subscapularis tenotomy. The author prefers the safe, reliable, and simple approach of subscapularis tenotomy, which has been shown to be biomechanically and clinically sound.
References 1. Miller SL, Hazrati Y, Klepps S, et al: Loss of subscapularis function after total shoulder replacement: A seldom recognized problem. J Shoulder Elbow Surg 12:29-34, 2003 2. Van Thiel GS, Wang VM, Wang FC, et al: Biomechanical similarities among subscapularis repairs after shoulder arthroplasty. J Shoulder Elbow Surg 19:657-663, 2010 3. Giuseffi SA, Wongtriratanachai P, Omae H, et al: Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2011 Oct 5 (Epub ahead of print) 4. Caplan JL, Whitfield B, Nevaiser RJ: Subscapularis function after primary tendon to tendon repair in patients after replacement arthroplasty of the shoulder. J Shoulder Elbow Surg 18:193-196, 2009 5. Gerber C, Yian EH, Pfirrmann CA, et al: Subscapularis muscle function and structure after total shoulder replacement with lesser tuberosity osteotomy and repair. J Bone Joint Surg Am 87:1739-1745, 2005