The Lesser Tuberosity Osteotomy Exposure for Total Shoulder Arthroplasty

Abstract

Background: The lesser tuberosity osteotomy (LTO) is a commonly employed technique for mobilizing the subscapularis tendon during anatomic total shoulder arthroplasty that is performed through a deltopectoral approach. During this procedure, the lesser tuberosity is osteotomized from the proximal aspect of the humerus while maintaining the strong tendon-to-bone attachment of the subscapularis tendon insertion. After the shoulder arthroplasty is performed, the lesser tuberosity osseous fragment is then resecured to the proximal aspect of the humerus with heavy nonabsorbable suture, which allows for direct bone-to-bone compression and healing of the fragment to the proximal aspect of the humerus. This technique may be utilized for subscapularis tendon mobilization in any primary and some revision anatomic total shoulder arthroplasty procedures. Description: The procedure is performed as follows. (1) Preoperative planning is performed. (2) The patient is positioned in the semi-upright beach-chair position, and the shoulder girdle and the upper arm are prepared and draped. (3) A standard deltopectoral approach is utilized. (4) A tenotomy of the long head of the biceps tendon is performed, exposing the bicipital groove. (5) An LTO is made from lateral to medial with an oscillating saw and is completed with use of an osteotome. (6) The remaining inferior portion of the subscapularis and capsule are released off of the humerus. (7) The total shoulder arthroplasty is completed up to the point of implantation of the final humeral component. (8) Four drill-holes are made lateral to the bicipital groove and osteotomy site. (9) Heavy nonabsorbable sutures, with or without cerclage wires, are passed from lateral to medial around the humeral stem and passed medial to the osteotomy fragment through the insertion of the subscapularis tendon. (10) The sutures are then tensioned and tied with the arm in 30° of external rotation. (11) The wound is irrigated, dried, and closed in layered fashion. Alternatives: The most commonly accepted alternative approaches include the subscapularis tenotomy and subscapularis peel techniques. Rationale: The LTO approach technique was developed to take advantage of bone-to-bone healing and to address concerns regarding poor tendon-to-tendon or tendon-to-bone healing in the subscapularis tenotomy and subscapularis peel exposure techniques, respectively. Expected Outcomes: Based on numerous published studies, excellent clinical results are achieved with anatomic total shoulder arthroplasty. When comparing surgical techniques involving the subscapularis in Level-I, randomized controlled trials, no significant differences exist among clinical outcomes, range of motion, or strength between the different techniques. Important Tips: Three-dimensional preoperative templating software allows for the anticipation of potential operative challenges, the prediction of implant limitations, and more accurate assessment of abnormal glenoid morphology and wear patterns.An articulating arm positioner can be helpful in controlling the arm position without the need for an extra surgical assistant.The goal thickness of the LTO is 10 mm. If the osteotomy is made too thin, there is a risk that the repair sutures cut through the lesser tuberosity fragment, leading to subscapularis repair failure.Releasing the capsule from the subscapularis is a critical step to ensure adequate tendon excursion for later repair and restoration of external rotation in arthritic shoulders. However, careful attention must be directed to the position and orientation of the axillary nerve in order to avoid iatrogenic injury during this critical step.Creating the drill-holes lateral to the bicipital groove takes advantage of the very strong and dense bone in that area of the proximal aspect of the humerus, enhancing the integrity of the repair.The tension band suture is critical to aid in further compression of the LTO fragment when the arm is brought into external rotation.Closing the rotator interval substantially increases the strength of the subscapularis repair; however, the closure of the interval must be made with the arm in at least 30° of external rotation in order to avoid iatrogenic motion restriction.Using interrupted nonabsorbable sutures to close the deltopectoral interval at the conclusion of the procedure is helpful in the event that any revision procedure is needed because these sutures will guide the revision surgeon toward making the deltopectoral approach in the correct interval. Acronyms and Abbreviations: LTO = lesser tuberosity osteotomyROM = range of motionASES = American Shoulder and Elbow SurgeonsWOOS = Western Ontario Osteoarthritis of the Shoulder indexVAS = visual analog scaleSF-36 = 36-Item Short Form Health SurveySST = Simple Shoulder TestDVT = deep-vein thrombosis

Custom, 3-Dimensional Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty: Part 2, Dissection and Soft Tissue Management

“… 22 Yet, these three techniques have shown similar results biomechanically regarding cyclic tendon elongation and load to failure. 23 Although some evidence suggests better results with LTO compared with subscapularis peel and tenotomy, 24 , 25 clinical trials have demonstrated that the techniques presented similar clinical outcomes and healing, 26 , 27 , 28 , 29 advocating that the choice of the technique should rely also on the surgeon preference and experience. In all techniques, care must be taken when releasing the subscapularis muscle belly medially and manipulating the tendon, as the muscle innervation can be at risk in the DP approach.…”

Lesser Tuberosity Osteotomy Combined with Anteroinferior Capsulectomy for Anatomic Shoulder Arthroplasty

“…Regardless of the technique used for subscapularis management, release of the capsule from the subscapularis during TSA is a pivotal step to ensure adequate glenoid exposure and tendon excursion for lateral repair, as well as restoration of range of motion in the arthritic shoulder. 5 Lovse et al 17 performed a cadaveric analysis to understand how various softtissue releases impacted glenoid exposure. They found that release of the long head of the biceps increased glenoid exposure to 69%, which subsequently increased to 83% after pectoralis major release and finally to 93% exposure after inferior capsular release.…”

“…[2][3][4] LTO has multiple potential benefits, including bone-tobone healing of the repair, a bony fragment that decreases pull-through of the sutures, easy postoperative repair surveillance with radiographs, and decreasing the anterioreposterior dimension of the humerus, which may aid in glenoid exposure. 5 Stemless and mini-stem arthroplasty was initially felt to be a contraindication to this technique, but this been shown not to be the case. 6,7 Despite these theoretical benefits and a host of retrospective and caseecontrol data, 2,[8][9][10][11][12][13] prospective, Level I studies have shown no difference compared with subscapularis peel or tenotomy.…”

“…6,7 Despite these theoretical benefits and a host of retrospective and caseecontrol data, 2,[8][9][10][11][12][13] prospective, Level I studies have shown no difference compared with subscapularis peel or tenotomy. 4,5,14,15 Another key component of anatomic TSA is thorough release of the contracted anterior and inferior capsular tissues. 16,17 In the past few years, a growing body of evidence has shown these tissues to be pathologically thickeneddcontaining multiple contractile, biologically active and proinflammatory mediators, affecting the pattern of osteoarthritis on the humeral head, and affecting posterior subluxation and posterior glenoid erosion in the pathogenesis of glenohumeral osteoarthritis.…”