Subscapularis-sparing Approach Research Articles

Managing Subscapularis in Shoulder arthroplasty

Managing subscapularis forms an integral part of shoulder arthroplasty and the ideal technique for subscapularis release and repair during shoulder arthroplasty is still under debate. The three common techniques are tenotomy, peel and lesser tuberosity osteotomy (LTO). Current literature from clinical studies does not show any difference in the outcome between the 3 techniques. However biomechanical studies favour LTO. Subscapularis sparing approach can be an alternative solution allowing early rehabilitation but needs further clinical studies to assess its longterm benefits. Failure of subscapularis repair in anatomical shoulder replacement can lead to pain, loss of movements, instability and loosening of implants. Treatment options include revision repair, tendon transfer, reconstruction with allograft tendon and revision to reverse shoulder arthroplasty (RSA). Repairing subscapularis in RSA can improve rotations and stability, however it also has adverse biomechanical effects on deltoid. Absence of subscapularis repair is seen to affect stability only in medialised implant designs, while no such effects are seen in lateralised design implants.

Retrospective analysis of the subscapularis-sparing approach for reverse total shoulder arthroplasty.

The influence of the subscapularis tendon on reverse total shoulder arthroplasty (RTSA) has been discussed controversially. The aim of the study was to investigate the subscapularis-sparing approach for RTSA and the effect of the intact subscapularis tendon. This retrospective comparative study included 93 patients. Among these, 55 underwent the deltopectoral subscapularis-sparing approach, and in 38 cases, the standard deltopectoral approach with subscapularis tenotomy was applied. At the final follow-up, representative shoulder scores were measured, radiographs were taken in two planes, and shoulder sonography was performed. The subscapularis-sparing group showed a significantly higher Constant score (71.8 vs. 65.9 points) and adapted Constant score if the subscapularis tendon was shown to be intact in the postoperative sonography (85.2% vs. 78.6%) (p = 0.005; p = 0.041). Furthermore, these patients had improved abduction (128.2 vs. 116.8, p = 0.009) and external rotation (34.6 vs. 27.1, p = 0.047). However, no significant differences were found for the degree of internal rotation and internal rotation strength. No dislocation or infection was observed. The degree of scapular notching was not significantly different between the two groups (p = 0.082). However, independently from the integrity of the subscapularis the subscapularis-sparing approach showed no difference in clinical and radiographic outcome (Constant score scapularis-sparing 70.0 points vs. tenotomy 66.8 points; p = 0.27). The subscapularis-sparing approach RTSA showed improved clinical outcome, abduction, and external rotation, if the subscapularis was shown to be intact at time of follow-up. Both groups showed no difference in internal rotation.

Management of Subscapularis Insufficiency After Total Shoulder Arthroplasty.

The functional success of anatomic total shoulder arthroplasty (TSA) relies heavily on the healing integrity of the subscapularis tendon. Access to the glenohumeral joint is performed through a deltopectoral approach, and takedown of the subscapularis tendon is necessary in most surgeons' hands. Although initially described as a tenotomy, lesser tuberosity osteotomy and subscapularis peel are two techniques more commonly used today. Both of these options offer good results as long as proper repair is done. A subscapularis-sparing approach has more recently been advocated but is technically demanding. Failure of tendon repair can lead to early failure of anatomic total shoulder arthroplasty with accelerated glenoid loosening, decreased function, and anterior instability. Treatment options for subscapularis insufficiency include nonsurgical management, revision tendon repair, tendon reconstruction or transfer, or conversion to reverse shoulder arthroplasty. As shoulder arthroplasty continues to become increasingly prevalent, subscapularis insufficiency, too, will become more common. Accordingly, a surgeon's knowledge of subscapularis management in an arthroplasty setting must encompass treatment options for postoperative subscapularis insufficiency.

Ultrasound assessment after a subscapularis-sparing approach to total shoulder arthroplasty.

Although anatomic total shoulder arthroplasty (ATSA) has favorable outcomes, nearly all techniques involve subscapularis tendon release for shoulder joint access. Such takedown of the subscapularis may be associated with decreased function, instability, and pain. Subscapularis-sparing approaches have the theoretical benefits of improved function, decreased failure of the tendon reattachment site, and early range of motion and rehabilitation. The primary purpose of this study was to use ultrasound to assess the postoperative integrity of the subscapularis tendon and surrounding soft tissues after ATSA with a subscapularis-sparing technique through an extensile anterosuperior skin incision. Our hypothesis was that this subscapularis-sparing approach would have low rates of subscapularis disruption. A consecutive cohort of patients who underwent subscapularis-sparing ATSA between 2014 and 2017 were included. Ultrasound was used to evaluate the rotator cuff tendons and deltoid postoperatively, and these were classified as intact, disrupted, or unable to be adequately visualized. Clinical outcome scores, range of motion, and strength measurements were also collected at 1-3 years postoperatively. Thirty-seven subscapularis tendons and 40 supraspinatus and infraspinatus muscles were adequately visualized and included for analysis. Of the subscapularis muscles, 32 (86%) were intact; 38 of the visualized supraspinatus muscles (95%) and 39 of the infraspinatus muscles (98%) were intact. No dehiscence or loss of integrity of the deltoid was noted. Clinical comparison between patients with disrupted subscapularis muscles and patients without such disruption demonstrated no difference in clinical outcome scores and postoperative range of motion but showed less strength in forward flexion, abduction, and external rotation. The rate of subscapularis disruption using a subscapularis-sparing approach for ATSA was low (14%), but the potential for tendon disruption was not eradicated. Favorable clinical outcomes support this surgical approach as a potential technique for ATSA.

Comprehensive Modified Latarjet Technique: What the Masters Taught Us.

The Latarjet technique can be performed via a cosmetic axillary-based approach. The subscapularis is split horizontally without detachment as described by Neer5. The capsule is released like in a medially based T-plasty as described by Altchek et al.6. The coracoid osteotomy is performed with a 90° oscillating saw and prepared for en-face implantation as described by Edwards and Walch7. The inferior surface of the coracoid is decorticated and prepared per Molé8. Coracoid fixation is performed with two 3.5-mm cortical screws. The soft-tissue reconstruction is selectively tensioned per Warner et al.9. The capsular shift is augmented with a pants-over-vest repair per Kim et al.10. Nonoperative treatment in young patients with glenohumeral instability and bone loss can lead to recurrence rates as high as 87%11. Arthroscopic management with anterior capsulolabral repair and a remplissage procedure can be beneficial for patients with instability. In the setting of bone loss, arthroscopic repair is associated with failure rates as high as 75%12. In the setting of glenoid and/or humeral bone loss, there is a loss of native osseous anatomy, leading to a higher risk of instability. Gerber and Nyffeler reported a >30% loss of compressive force when the vertical edge of the glenoid defect is greater than one-half of the glenoid diameter13. The Latarjet procedure is a reliable procedure that reconstructs the anterior osseous anatomy as well as the capsular laxity, restoring glenohumeral stability. When compared with arthroscopic labral repair, the Latarjet procedure is superior with more consistent improvements in functional outcomes with low risk of recurrence, even in high-risk populations of young, active athletes in contact sports2,3. At our institution, a total of 34 patients underwent Latarjet reconstruction as described in the present article and videos from 2013 to 2018, with a minimum follow-up of 1 year. Among these patients, the mean Single Assessment Numeric Evaluation score was 90.7 (range, 70 to 100). There were 4 cases of recurrent instability with graft fracture or resorption (11.8%). Zimmermann et al. presented a series of Latarjet reconstructions with similar functional outcomes and a recurrence rate of 11%4. Meta-analysis of long-term Latarjet studies show high rates of return to sports and successful outcomes in 86% of cases, with an 8.5% recurrence rate2. The Latarjet procedure can be consistently performed with a subscapularis-sparing approach, which minimizes adverse comorbidities.Splitting the subscapularis at the inferior one-third junction will position the surgical window directly over the bottom half of the glenoid, which optimizes coracoid implantation.A medially based T-plasty will maximize the glenoid exposure for direct coracoid implantation. Subsequently, the capsule may be shifted for capsular imbrication.Low-profile, non-bulky retractors will help to improve visualization.Adjusting the arm is a key technique in performing this surgical procedure. This adjustment will help to shift the surgical window, expose key anatomic structures, and allow a capsular shift without overtensioning. This cannot be overstated.

The subscapularis-sparing windowed anterior technique for total shoulder arthroplasty.

Traditionally, total shoulder arthroplasty (TSA) involves detaching the subscapularis tendon through either tenotomy or lesser tuberosity osteotomy. A subscapularis-sparing approach avoids detachment but may make re-creation of the anatomy more difficult because of limited exposure. The primary aim of this study was to evaluate the ability to re-create the proximal humeral geometry and assess for osteophyte removal with this technique. The secondary aim was to assess for complications or an inability to complete the procedure with this technique. We performed a retrospective review of a consecutive series of 47 patients (100% with osteoarthritis; 59% Walch type A and 41% Walch type B; 50% male and 50% female patients; and average body mass index, 28.21 ± 4.6) who underwent the subscapularis-sparing windowed anterior technique for TSA. The ability to reconstruct the proximal humeral geometry and remove the inferior osteophytes was assessed by 2 independent observers using the center-of-rotation difference (ΔCOR) between the native and prosthetic humeral heads. The ability to complete the procedure was recorded, and a chart review was performed to assess for complications. The procedure was successfully completed in 44 of the 47 patients. Radiographic review demonstrated an average ΔCOR of 2.28 mm (range, 0.2-6.05 mm; intraclass correlation coefficient, 0.971), below the previously reported acceptable ΔCOR of 3 mm. The ΔCOR was >3 mm in 31.8% of patients (14 of 44; 8 Walch type A and 6 Walch type B; 9 male and 5 female patients). There was no difference in ΔCOR based on Walch type (P = .824). Male patients on average showed a higher ΔCOR (2.62 mm) than female patients (1.94 mm) (P = .099) and more commonly had a ΔCOR > 3 mm (P = .195). Body mass index was not significantly correlated with ΔCOR (r = 0.077, P = .619). For all cases in which the ΔCOR was >3 mm, the prosthetic humeral head was undersized. Osteophytes were successfully removed in 75% of cases (33 of 44) and had no effect on average ΔCOR (P = .468). No revisions or mechanical failures in the early postoperative period were identified in the treatment group of 44 patients (range, 3-15 months). In the group with unsuccessful treatment, there was 1 case of infection treated with 1-stage revision reverse TSA. The subscapularis-sparing windowed anterior technique is an effective approach to TSA that allows for early unrestricted motion. Over 90% of cases can be completed using this technique. Radiographic analysis demonstrated that this approach can be used successfully without compromising anatomic reconstruction of the proximal humerus. Further study is necessary to identify patient factors that would favor a traditional deltopectoral approach and to assess the functional outcomes of this technique.

The V-shaped subscapularis tenotomy for anatomic total shoulder arthroplasty

Management of the subscapularis tendon during anatomic total shoulder arthroplasty (TSA) remains controversial. In our unit, subscapularis tenotomy is the preferred technique; however, the potential for tendon gapping and failure is recognised. The purpose of this study is to describe and provide early clinical results of a novel, laterally based V-shaped tenotomy (VT) technique hypothesised to provide greater initial repair strength and resistance to gapping than a transverse tenotomy (TT), with both clinically and radiologically satisfactory post-operative tendon healing and function. A retrospective study of patients who underwent primary TSA with VT over a threeyear period was performed using shoulder and subscapularis-specific outcome scores, radiographs, and ultrasound. A separate cohort of patients who underwent TSA using a subscapularis sparing approach was also reviewed to provide comparative clinical outcomes of a group with TSA and an un-violated subscapularis. Eighteen patients were reviewed at mean 30.4 months (± 11.7). Constant (78.2 ± 12.3), UCLA (8.4 ± 1.5), pain VAS (2.3 ± 2.8), and strength in internal rotation were no different from the comparison group. Likewise, neither were the clinical outcomes of range-of-motion, belly-press, lift-off, and shirt-tuck tests. One patient (5.5%) was found to have a failed subscapularis repair on ultrasound. VT during TSA appears to provide healing rates at least equal to those reported for TT, and not dissimilar from those of lesser tuberosity osteotomy. Clinical outcomes are comparable to reported results in the literature for alternative techniques, and not different from those observed here in a comparison cohort with TSA performed without violating the subscapularis tendon. VT therefore potentially offers a more effective and secure tendon repair than a traditional TT, with at least comparable clinical outcomes.

Comparison of Subscapularis Management and Repair Techniques.

Management of the subscapularis tendon is a crucial step during the approach for total shoulder arthroplasty. The method of mobilizing the tendon and the technique used to repair it determine the initial integrity of the subscapularis and impact its capacity to heal. Currently, there exist 3 well-described and well-studied approaches to managing and repairing the subscapularis: subscapularis tenotomy, subscapularis peel, and lesser tuberosity osteotomy. More recently, a subscapularis-sparing approach has been proposed as an option. There is debate in the literature regarding which technique provides optimal strength and stability for subscapularis repair following shoulder arthroplasty. In this symposium, we provide an overview of each of the techniques and review the biomechanical studies comparing them.

Subscapularis-Sparing Rotator Interval Approach for Anatomic Total Shoulder Arthroplasty.

A subscapularis-sparing approach to anatomic total shoulder arthroplasty (TSA) is used for patients with glenohumeral osteoarthritis who have an intact rotator cuff and sufficient bone volume. A 7 to 10-cm anterosuperior incision is made with the patient in the beach chair position. The anterolateral deltoid muscle raphe is split, and the shoulder is externally rotated to bring the rotator interval to the field. A flap of interval tissue is incised, tenodesis of the biceps tendon is performed, and the interval tissue is incised straight back to the glenoid from the upper edge of the subscapularis, creating a triangular piece of tissue referred to as a "trapdoor." Two Darrach retractors are placed to expose the humeral head. An intramedullary guide is placed, and a humeral head osteotomy is performed. The glenoid is exposed, and the glenoid component is placed after sizing, preparation, drilling, and insertion of trial components per the surgical technique. The humeral head size is estimated by measuring, and the humeral stem size is decided by sequentially inserting the trial components. The permanent humeral stem is inserted, and the permanent humeral head is implanted after insertion of trial components. The trapdoor is sutured, the deltoid is reattached, and subcutaneous tissue and skin are sutured. The traditional surgical approach for anatomic TSA involves release and reattachment of the subscapularis tendon. Nearly all anatomic TSA techniques require the subscapularis to be released, with a peel, tenotomy, or osteotomy, and then repaired on completion of the arthroplasty. Failure of the subscapularis to heal is an unfortunate and potentially devastating complication following anatomic TSA that has been linked to decreased function, instability, and pain1-4. Subscapularis dysfunction following anatomic TSA is seen in one-third to two-thirds of patients, with evidence of complete tears in up to 50% of asymptomatic patients using ultrasound examinations1-5.Sling immobilization with avoidance of excessive passive external rotation and active internal rotation is recommended to help prevent postoperative rupture of the subscapularis repair6-8. However, postoperative motion restrictions to protect the subscapularis may lead to stiffness and may negatively impact function and satisfaction.We describe a subscapularis-sparing TSA, in which we address and improve on 3 technical difficulties identified by Lafosse et al.9: (1) difficulty ensuring an anatomic humeral neck cut because of the difficulty visualizing the anterior aspect of the shoulder, (2) inadequate resection of inferior humeral neck osteophytes, and (3) undersizing of the humeral head.

Biomechanical characteristics of subscapularis-sparing approach for anatomic total shoulder arthroplasty

A technique for retaining the superior 50% of the subscapularis insertion for anatomic total shoulder arthroplasty has been described. This cadaveric study biomechanically evaluates this subscapularis-sparing approach and compares it with a complete subscapularis release and repair technique to determine whether there is a higher load to failure. Twelve matched pairs of human cadaveric arms were distributed into 3 test groups. Group 1 consisted of specimens with and without a 100% subscapularis release. Group 2 consisted of specimens with and without an inferior 50% subscapularis release. Group 3 consisted of specimens with either an inferior 50% or 100% release of the subscapularis footprint and repair. All tendon repairs were performed using bone tunnels and sutures. Specimens were biomechanically tested using non-destructive cyclic and tensile failure-inducing loads. In matched pairs, the following comparative results were obtained: native intact subscapularis specimens exhibited a load to failure of 1341.20 ± 380.10 N compared with 380.10 ± 138.79 N in the 100% release specimens (P = .029), native intact subscapularis specimens exhibited a load to failure of 1209.74 ± 342.18 N compared with 744.33 ± 211.77 N in the 50% release specimens (P = .057), and 50% release and repair specimens exhibited a load to failure of 704.62 ± 165.53 N compared with 305.52 ± 91.39 N in the 100% release and repair group (P = .029). Preservation of the superior 50% of the subscapularis demonstrates a higher load to failure compared with complete subscapularis release and repair using bone tunnels.

CORR Insights(®): Obesity is Not Associated with Increased Short-term Complications After Primary Total Shoulder Arthroplasty.

CORR Insights(®): Obesity is Not Associated with Increased Short-term Complications After Primary Total Shoulder Arthroplasty.

Total shoulder arthroplasty using a subscapularis-sparing approach: a radiographic analysis

Traditional total shoulder arthroplasty (TSA) involves releasing the subscapularis tendon for exposure. This can potentially lead to subscapularis insufficiency, compromised function, and dissatisfaction. A novel TSA technique preserves the subscapularis tendon by performing the procedure entirely through the rotator interval, allowing accelerated rehabilitation. However, early reports on this approach have noted malpositioning of the humeral component and residual osteophytes. In a randomized trial, we examined the incidence of humeral head malpositioning, incorrect sizing, and residual osteophytes on postoperative radiographs after subscapularis-sparing TSA compared with the traditional approach. Patients were prospectively randomized to undergo TSA performed through the traditional or subscapularis-sparing approach. The operating surgeon was blinded to the randomization until the day of surgery. Anatomic reconstruction measurements included humeral head height, humeral head centering, humeral head medial offset, humeral head diameter (HHD), and head-neck angle. Two independent reviewers analyzed the postoperative radiographs to determine anatomic restoration of the humeral head and the presence of residual osteophytes. We randomized 96 patients to undergo either the standard approach (n = 50) or the subscapularis-sparing approach (n = 46). There were no significant differences in humeral head height, humeral head centering, humeral head medial offset, HHD, head-neck angle, and anatomic reconstruction index between the 2 groups. However, significantly more postoperative osteophytes (P = .0001) were noted in the subscapularis-sparing TSA group. Although the overall mean was not statistically different, further analysis of HHD showed that more patients in the subscapularis-sparing TSA group were outliers (mismatch >4 mm) than in the traditional TSA group. Although anatomic restoration of the shoulder can be accomplished using subscapularis-sparing TSA, retained osteophytes and significant mismatch of the HHD raise concerns regarding long-term outcomes.

The subscapularis-sparing approach in humeral head replacement

This report represents a prospective case series evaluating an open deltopectoral approach, both radiologically and clinically, without tenotomy or complete takedown of the subscapularis tendon insertion. We hypothesized that this novel technical approach would allow preservation of the upper tendon border, thus decreasing subscapularis repair failures and fatty infiltration while simultaneously allowing accelerated rehabilitation. Fifty patients underwent humeral head replacement surgery through a subscapularis-sparing approach. In this approach, we take down only the inferior 30% to 50% of the subscapularis tendon, leaving the critical superior aspect of the tendon attached to the lesser tuberosity. Forty-three patients were included in the postoperative results (7 were lost to follow-up). Nineteen patients had a postoperative magnetic resonance imaging study, and 24 patients had ultrasound evaluation. Physical examination included belly-press and lift-off tests; follow-up included visual analog scale, American Shoulder and Elbow Surgeons, Constant, modified UCLA, Rowe, and Short Form 12 scores. All patients had a minimum 2-year follow-up. All patients had subscapularis strength equal to the opposite side as measured by lift-off, belly-press, and bear hug tests. Average postoperative scores all showed statistically significant improvement except for general health. All had an intact subscapularis tendon attachment as evaluated by either magnetic resonance imaging or ultrasound imaging. None had atrophy in the muscle belly. The subscapularis-sparing, minimally invasive approach to the glenohumeral joint provides adequate exposure to allow humeral head replacement. When the upper border of the subscapularis insertion is left intact, there is a decreased risk of postoperative failure (rupture or atrophy) of the subscapularis tendon.

Surgical treatment of significant glenoid bone defects and associated humeral avulsions of glenohumeral ligament (HAGL) lesions in anterior shoulder instability

Combined occurrence of humeral avulsion of glenohumeral ligament (HAGL) lesion and a significant glenoid bone defect is an unusual and previously undescribed association in traumatic anterior shoulder instability. The purpose of this study was (1) to report a retrospective case series of seven anterior bony instability patients who were diagnosed with this unusual association and (2) to evaluate the results of a modified Latarjet procedure and simultaneous HAGL repair using a new subscapularis-sparing approach. A retrospective review of the records of 64 anterior shoulder instability patients who underwent bony stabilization surgery was performed, and patients who underwent a combined reconstruction for significant glenohumeral bone defects (glenoid loss >20 %) and an associated HAGL lesion were identified. Pre- and postoperative follow-up clinical parameters and functional scores were documented (Oxford shoulder instability score [OSIS], Western Ontario shoulder instability index [WOSI]), Rowe score). Radiological assessment included measurement of the glenoid bone defect (CT scan) and evaluation of soft tissue lesions (MR arthrogram). Radiological and arthroscopic evaluation confirmed the combined lesion complex in 7 (11 %) patients. Follow-up evaluation (mean 20.6 months) suggested an excellent outcome (Rowe score: median 95, range 95-100); a statistically significant improvement was seen in the follow-up OSIS (median 12, range 12-14, p = 0.018) and WOSI score (median 28, range 17-102, p = 0.018) as compared to the preoperative score (median OSIS 50, range 32-53; median WOSI 1,084, range 919-1,195). Clinical tests for subscapularis function revealed a functional subscapularis muscle; no significant differences were detected in pre- versus postoperative internal rotation strength and in the operated versus normal contralateral shoulder (ns). The dual-window subscapularis-sparing approach provided adequate exposure for combined reconstruction of the humeral and glenoid lesions, and no complications were encountered. Significant glenoid defects are associated with HAGL lesions in approximately 1/10th of patients with bony instability. Combined reconstruction of these lesions via a subscapularis-sparing approach results in an excellent outcome and significant improvement in functional scores at a medium-term follow-up. Therapeutic study, Level IV.

Dual-window Subscapularis-sparing Approach

Combined bankart lesion and humeral avulsion of glenohumeral ligament lesion (HAGL) is a well-described pathologic complex in anterior shoulder instability; open surgical approaches with and without arthroscopic assistance have been suggested for simultaneous 1-stage repair of these lesions. Presence of a significant glenoid bone defect (inverted-pear glenoid) adds to the complexity of the problem and necessitates a bony reconstruction procedure. Open surgical approaches described for management of this combined lesion complex in anterior shoulder instability necessitate a subscapularis-cutting approach; suboptimal healing of the tenotomized subscapularis and subsequent delayed rehabilitation predisposes to late subscapularis dysfunction, and this compromises clinical outcomes. This study describes a new surgical technique that utilizes a dual-window approach through the subscapularis muscle; the dual window enables access to the glenoid and humeral lesions without the need for a subscapularis tenotomy. The approach can be used to perform a congruent-arc Latarjet procedure (for glenoid bone defects) or a Bankart repair (for capsulolabral lesions), in combination with a HAGL repair. Preliminary arthroscopy is essential to identify significant bone defects and HAGL lesions. The dual-window approach for reconstruction of the lesions involves (1) a lateral "subscapularis-sparing" window to identify and repair the HAGL lesion; (2) a medial "subscapularis muscle-splitting" window to perform either a glenoid capsulolabral reconstruction or a congruent-arc Latarjet procedure; and (3) a balanced inferior capsular shift and lateralization procedure of the glenohumeral capsule. Technical tips and guidelines to avoid complications are discussed, and a rehabilitation protocol is presented.