Short-term outcomes of anatomic total shoulder arthroplasty with biceps augmentation of subscapularis peel repair

Article information

Clin Shoulder Elb. 2025;28(1):15-22

Publication date (electronic) : 2024 November 21

doi : https://doi.org/10.5397/cise.2024.00549

Mohamad Y. Fares, Peter Boufadel, Jonathan Koa, Jaspal Singh, Ryan Lopez, Nabil Mehta, Kyle Achors, Joseph A. Abboud

Division of Shoulder and Elbow Surgery, Rothman Orthopaedic Institute, Philadelphia, PA, USA

Corresponding Author: Joseph A. Abboud Division of Shoulder and Elbow Surgery, Rothman Orthopaedic Institute, 925 Chestnut St, Philadelphia, PA 19107, USA Tel: +1-610-547-8351, Email: abboudj@gmail.com

Received 2024 July 16; Revised 2024 August 27; Accepted 2024 September 16.

Abstract

INTRODUCTION

Anatomic total shoulder arthroplasty (aTSA) is a surgical procedure that involves replacing the arthritic surfaces of the glenohumeral joint to eliminate pain and restore the anatomic and functional integrity of the shoulder [1,2]. The procedure is typically performed using a deltopectoral approach and involves releasing the subscapularis muscle to gain visibility and exposure to the joint [3]. Subscapularis exposure can be performed using multiple techniques including subscapularis peel, subscapularis tenotomy, and lesser tuberosity osteotomy [4-7]. The subscapularis muscle is then repaired following procedural guidelines. Meticulous care is taken during postoperative rehabilitation to avoid re-injuring the repaired tendon [4].

The integrity of the subscapularis muscle following aTSA is integral for achieving good outcomes and high levels of patient satisfaction [8,9]. Subscapularis repair failure after aTSA, which has an average reported incidence of 1%–6% and a maximum of 13%, is considered a significant complication following surgery. Repair failure can lead to persistent disability, pain, component failure, and need for reoperation [4,10]. Attempting repair in this setting can lead to equivocal outcomes, and conversion to reverse shoulder arthroplasty is the most viable, yet invasive, option available [11]. Accordingly, ensuring the robustness and strength of the subscapularis repair following aTSA is crucial for achieving optimal patient outcomes and high levels of postoperative patient satisfaction.

Recently, a new subscapularis repair technique, the “biceps-subscap sling” technique, was described by Cohn et al. [12]. This technique utilizes the long head of the biceps tendon (LHBT) to augment the subscapularis peel repair following aTSA [12]. This technique was based on a biomechanical study that highlighted the utility of the LHBT in augmenting repair of a subscapularis peel following aTSA [12]. The authors demonstrated greater time zero load to failure and stiffness compared to a standard subscapularis peel repair [12]. However, clinical data supporting the use of the LHBT to augment the subscapularis has not been acquired. Therefore, the aim of this case series was to report the outcomes of aTSA patients who underwent the “biceps-subscap sling” technique for subscapularis peel repair.

METHODS

After obtaining an exemption from the Institutional Review Board at Thomas Jefferson University (iRISID-2023-2496), a retro­spective chart review was performed for all patients who under­went aTSA and the “biceps-subscap sling” technique for sub­scapularis peel repair and who had a minimum follow-up of 1 year. The technique involves releasing the LHBT from the supraglenoid tubercle, utilizing a pulvertaft weave to integrate the tendon into the subscapularis, and using transosseous sutures to conduct the peel repair [12]. Due to the retrospective nature of our study, the requirement of a written informed consent from the patients was waived.

The full technique has been thoroughly described by Cohn et al. [12], and a summary of the technique is presented in Fig. 1. All consecutive aTSA patients whose clinical history, physical examination results, and imaging findings showed significant glenohumeral osteoarthritis with intact rotator cuffs since 2022 and who underwent the technique were screened. The “biceps-subscap sling” was only performed in patients with a healthy LHBT; those with a ruptured or degenerative LHBT were not eligible for the technique. Only patients with adequate preoperative and postoperative patient-reported outcome data were included. An experienced, fellowship-trained shoulder and elbow surgeon performed the procedure for all patients.

Fig. 1.

Summary of the “biceps-subscap sling” technique: (A) the long head of the biceps tendon (LHBT) is identified and released (yellow arrow). The tendon is then tagged using a Krackow stitch. The subscapularis is tagged and peeled from the lesser tuberosity, and shoulder arthroplasty is performed. (B) To perform the “biceps-subscap sling” technique for subscapularis peel repair, a blade is used to introduce an initial incision into the stretched subscapularis (black arrow). (C) The LHBT is then passed through this initial incision using a mosquito forceps. (D) Another subscapularis incision, superior to the initial incision (gray arrow), is made; and the LHBT is passed through the second incision (green arrow). (E) The LHBT is then pulled to tighten the construct, and a pulvertaft weave is performed to incorporate the tendon into the subscapularis. (F) Transosseous sutures, previously introduced into the humeral head, are passed medial to the LHBT. This serves as a ripstop into the subscapularis to perform subscapularis peel repair. (G) All sutures are passed and tied sequentially, and the final LHBT-integrated repair is achieved. (H) The last image shows the passage of the LHBT into the subscapularis (blue shade) between the two incisions (yellow shade) and then out of the subscapularis tendon.

Preoperative demographic data including patient age at surgery and gender were reported and included in our database. Intraoperative data were also collected and included implant design, length of the LHBT, and number of incisions introduced to the subscapularis during the technique. The primary outcomes were the American Shoulder and Elbow Surgeon (ASES) score and visual analog scale (VAS) pain score at 3, 6, and 12 months post-surgery. Preoperative and postoperative range of motion values including those for forward elevation, abduction, external rotation, and internal rotation to reach behind the back were obtained from the charts to assess change at final follow-up. Internal rotation was assessed according to the levels designated in Table 1, and change was reported according to the number of levels gained postoperatively.

Table 1.

Designated levels of internal rotation as assessed according to physical exam

A minimal clinically important difference (MCID) analysis was performed as per Tashjian et al. [13] who described the MCID for ASES and VAS scores following shoulder arthroplasty as improvement of 21 points and 1.4 points, respectively. An independent t-test was used to ascertain the statistical significance between preoperative and postoperative outcome ASES and VAS scores and preoperative and postoperative forward elevation, abduction, and external rotation values. The significance level was set at a P-value less than 0.05. Statistical analysis was conducted using the SPSS Windows software version 25.0 (IBM Corp.).

RESULTS

Complications and Conversion to Reverse Shoulder Arthroplasty

Of the 16 patients, two (12.5%) were converted to reverse shoulder arthroplasty (RSA), one for subscapularis failure at 2 months and one for glenoid component loosening at 13 months postoperatively. Of note, the patient who was revised at 2 months reported engaging in strenuous activity shortly after the procedure, without adherence to rehabilitation protocols. Both patients were excluded from our cohort analysis. A third patient noted persistent pain and dysfunction at 14 months postoperatively and underwent diagnostic arthroscopy for shoulder joint examination. No visible rotator cuff tear was observed at that time. The timeline of the recovery of these 3 patients is reported in Fig. 2.

Fig. 2.

Rehabilitation trends (American Shoulder and Elbow Surgeon [ASES] scores) of the three patients who exhibited complications in recovery following anatomic shoulder arthroplasty with the “biceps-subscap sling” technique for subscapularis peel repair.

Patient Reported Outcome Measures

Of 14 patients included in the cohort analysis, the mean preoperative ASES and VAS scores were 34.1 and 6.3, respectively. The mean postoperative ASES score improved significantly by 58.0 points to 92.1 at a mean follow-up of 12.4 months (P<0.001; standard error, 3.6). Moreover, the mean postoperative VAS score decreased significantly by 5.4 points to 0.9 (P<0.001; standard error, 0.6). All 14 patients noted improvements exceeding the MCID in both ASES and VAS at final follow-up.

Nine patients (64.3%) had a VAS of 0, and 10 patients (71.4%) had an ASES >90 at final follow-up. Table 2 shows the trends of recovery of our final cohort (n=14) at 3 months, 6 months, and 1 year of follow-up. At the 6-month follow-up, eight of the 11 patients had a VAS score of 0, and seven of the 10 patients had an ASES score >90 (Table 2). Postoperative mean ASES and mean VAS score trends are reported in Fig. 3A and Fig. 3B, respectively. Patients had a moderate reduction in symptoms at the 3-month follow-up and had the most significant improvement in scores at 6 months. This stabilized at around 1 year postoperatively (Fig. 3).

Table 2.

Trends of recovery of our final cohort (n=14) at 3 months, 6 months, and 9 months of follow-up

Fig. 3.

Trends in postoperative mean American Shoulder and Elbow Surgeon (ASES) (A) and visual analog scale (VAS) scores (B) at the 3-month, 6-month, and 1-year follow-ups.

Range of Motion

Preoperative and postoperative range of motion values are shown in Table 3. Thirteen patients had both preoperative and postoperative forward elevation values that improved from an average of 99.6°±31.6° to an average of 147.3°±21.7° (P<0.001). Twelve patients had both preoperative and postoperative abduction values available, reporting improvement from an average of 66.3°±22.3° to an average of 97.1°±12.5° at final follow-up (P<0.001). Similarly, 12 patients had both preoperative and postoperative external rotation values, reporting improvements from an average of 16.9°±11.1° to an average of 38.3°±7.2° at final follow-up (P<0.001). Also, 11 patients had both preoperative and postoperative internal rotation values; on average, patients had a three-level improvement at final follow-up. Overall, all patients exhibited improvements in all criteria of range of motion except one patient who experienced a decrease in 10° of external rotation and one patient who exhibited no change in internal rotation level at final follow-up (Table 3).

Table 3.

Preoperative, postoperative, and overall change in range of motion values of the patients included in our study

DISCUSSION

Our study showed that patients undergoing aTSA with augmented subscapularis peel repair have favorable outcomes postoperatively. Conversion to RSA occurred in two patients, one for subscapularis failure and one for glenoid component loosening. However, all other patients noted significant improvements in ASES and VAS scores that exceeded their MCID and significant improvements in their range of motion at final follow-up. Fourteen of our 16 patients demonstrated significant improvements in ASES and VAS scores, and nine patients had a VAS score of 0, while 10 achieved an ASES score >90 at final follow-up. The technique employed in our study incorporates the LHBT into the subscapularis tendon when undergoing peel repair, and this has several advantages [12,14]. First, this technique thickens the subscapularis tendon and allows a more robust construct to promote better recovery and healing [12,14,15]. In addition, the LHBT acts as an autograft with live tenocytes that can enhance the healing capabilities of the biceps-subscapularis construct and allow a greater regenerative potential [12,14,15]. By maintaining the distal part of the LHBT and detaching the LHBT from the supraglenoid tubercle, the blood supply is retained; viable tenocytes can incorporate properly into the final repair [12,14,15]. In addition, by allowing the final cutting sutures to pass medial to the incorporated LHBT, we were able to create a ripstop that, in theory, assists the subscapularis peel repair in retaining strength and integrity [12]. These advantages were further bolstered by the findings of a biomechanical study that showed greater stiffness and load to failure when the subscapularis peel repair was augmented with the LHBT at time zero [15]. Consistent with these findings, the majority of our patients exhibited favorable patient-reported outcomes and demonstrated well-centered humeral heads on x-ray imaging (Fig. 4) at final follow-up.

Fig. 4.

Postoperative x-ray imaging (A: anterior-posterior; B: anterior-posterior with internal rotation view; C: axillary view; D: scapular-Y view) demonstrates a well-centered humeral head in a patient who underwent anatomic total shoulder arthroplasty with a subscapularis peel repair augmented with a long head of the biceps tendon.

Our findings also showed that augmenting subscapularis repair using the LHBT provided favorable results in range of motion. Mean forward elevation, abduction, external rotation and internal rotation values were significantly improved at final follow-up. While the technique involves incorporating the LHBT into the subscapularis, concerns around alterations in joint biomechanics may imply potential limitations in mobility postoperatively. Our results suggest that augmenting subscapularis repair with the LHBT did not limit range of motion and led to significant improvements at final follow-up.

Importantly, three patients, two of whom were converted to RSA, underwent re-operation due to persistent shoulder symptoms. One of the converted patients had a failed subscapularis at 2 months postoperatively, and the other was converted to an RSA for glenoid component loosening. A systematic review by Su et al. [16] reported an approximate 3.7% secondary rotator cuff failure proportion following aTSA, with around 1.1% requiring revision surgery. Other studies have reported subscapularis failure rates to be between 1 and 6%, and some ultrasound studies have suggested rates as high as 13% at an 8-month follow-up [4,10]. The results of our case series are similar to those reported in the literature. Several reasons may explain the outcomes of the three patients with subscapularis failure in our study. One patient did not adhere to rehabilitation protocols, and this may have caused subscapularis repair failure. In addition, the introduction of two incisions in the subscapularis when employing the technique may compromise the integrity of the tendon and cause it to lose strength over time. Moreover, the dynamic properties of the LHBT, which remains attached to its muscle belly after the procedure, may lead to muscular contractions that pull on the subscapularis peel repair. These proposed explanations need to be supported by adequately-designed biomechanical studies. While our study results showed that this technique may improve the aTSA and subscapular repair procedures, the utility of this technique remains in question, especially considering the added surgical time.

To confirm the use of this technique, additional studies with larger sample sizes need to be conducted. Preferably, larger comparative studies of the outcomes of conventional subscapularis peel repair to those utilizing the “biceps-subscap sling” technique would provide valuable insight. According to previous studies, the technique adds strength and robustness to the peel repair construct at time zero [15]. However, its clinical outcomes need to be further validated before the procedure can be considered for inclusion in surgical guidelines and protocols.

Our case series is the first to report results from LHBT augmentation of subscapularis peel repair and serves as a proof of concept of its general efficacy and safety. However, several limitations need to be addressed. Our case series consisted of a total of 16 patients, and a larger patient population is required before conclusively reporting on its utility and outcomes. Nevertheless, our sample size is adequate for providing a general idea of the expected outcomes following this technique. Moreover, our study was limited by its retrospective nature; thus, we were not able to obtain additional outcome measures such as postoperative dynamometric subscapularis tendon strength or postoperative integrity of subscapularis tendon assessments using ultrasound. Despite these limitations, the outcome measures employed in our study were sufficient to describe the functional and pain states of the shoulder joint.

CONCLUSIONS

Our study showed that patients undergoing aTSA with LHBT-augmented subscapularis repair had favorable short-term outcome scores and significant improvements in range of motion at final follow-up. The incorporation of an autograft such as the LHBT, with its high regenerative potential and live viable tenocytes, is proposed to increase the integrity and robustness of subscapularis peel repair postoperatively. However, given that two patients were converted to RSA, additional studies with larger patient populations that compare the outcomes of conventional subscapularis peel repair to those augmented with LHBT are necessary. While incorporation of the LHBT into subscapularis peel repairs has shown superior outcomes in cadaveric studies at time zero, establishing its usefulness in the clinical setting requires more evidence.

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