Glenoid lateralization and subscapularis repair are independent predictive factors of improved internal rotation after reverse shoulder arthroplasty.

PURPOSE: Reverse shoulder arthroplasty (RSA) has shown improvement in clinical outcomes for various conditions, although some authors expressed concern about the restoration of active internal rotation (AIR). The current study assesses preoperative and intraoperative predictive factors of AIR in patients having a Grammont-style RSA with a minimum five year follow-up. METHODS: We conducted a retrospective multicentric study, including patients operated on with a 155° Grammont-style RSA for cuff-related pathology or primary osteoarthritis with posterior subluxation or an associated cuff tear. Patients were clinically evaluated at a minimum of five year follow-up. Patients with previous surgery or those who had a tendon transfer with the RSA were excluded. Demographic parameters, BMI, preoperative notes, and operative reports were obtained from medical records. AIR was graded according to the constant score system from 0 to 10. RESULTS: A total of 280 shoulders in 269 patients (mean age at surgery, 74.9 ± 5.9 years) met the inclusion criteria and were analyzed. The average follow-up was 8.1 years (range, 5-16 years). Overall, AIR increased from 4.2 (SD 2.5, range 0 to 10) preoperatively to 5.9 (SD 2.6, range 0 to 10) at final follow-up. At the last follow-up, AIR increased in 56% of cases, was unchanged in 26% and decreased in 18%. In 188 shoulders (67%), internal rotation was functional and allowed patients to reach the level of L3 or higher. Multivariable linear regression found the following preoperative clinical factors predictive of worse AIR after RSA: male gender (ß = -1.25 [-2.10; -0.40]; p = 0.0042) and higher values of BMI (ß = -0.085 [-0.17; -0.0065]; p = 0.048). Two surgical factors were associated with better AIR after RSA: glenoid lateralization with BIO-RSA technique (ß = 0.80 [0.043; 1.56]; p = 0.039) and subscapularis repair (ß = 1.16 [0.29; 2.02]; p = 0.0092). CONCLUSIONS: With a mean of eight year follow-up (5 to 16 years), internal rotation was functional (≥ L3 level) in 67% of operated shoulders after Grammont-style RSA; however, two patients out of ten had decreased AIR after surgery. Male patients and those with higher BMIs had worse AIR, with glenoid lateralization (using the BIO-RSA technique) and subscapularis repair, as they are predictive of increased AIR after RSA. LEVEL OF EVIDENCE: Case series, Level IV.

The effect of subscapularis repair in reverse total shoulder arthroplasty depends on the design of the implant: a comparative study with a minimum 2-year follow-up.

INTRODUCTION: The role of the subscapularis (Ssc) tendon does not yet have a well-defined role in RSA. The purpose of the present study was to evaluate if the repair of the Ssc in RSA improves overall clinical and radiographic results and if it has the same results using a medialized design humeral stem compared to a lateralized design. METHODS: Eighty-four consecutive patients undergoing RSA were retrospectively analyzed. Nine patients were lost at FU. Two implants with similar glenosphere design and different stem design (medialized and lateralized) were used. The Ssc was repaired in case of good quality of the fibers and reducibility without tension intraoperatively. Patients were divided into four groups for data analysis depending on whether they had received a medialized or lateralized design and Ssc repair or not. Patients were reviewed at an average follow-up of 40.8 ± 13.1 months. Clinical outcome measures included Active range of motion (ROM), strength, visual analog scale (VAS), Constant-Murley score (CMS), and the American Shoulder and Elbow Surgeons score (ASES). Radiographic evaluation at final follow-up was performed to assess scapular notching, stress shielding, and radiolucent lines. RESULTS: No statistically significant clinical differences (p > 0.05) emerged between Lat/Ssc+ and Lat/Ssc-. Conversely, the patients belonging to the Med/Ssc- group reported statistically worse (p < 0.05) results than the Med/Ssc + group in terms of VAS, ASES and CMS. Statistically worse (p < .05) results in the Med/Ssc- group than in the Med/Ssc + were found also in active ROM achieved in FE, ABD, ER1 and ER2, and in the strength obtained in FE, ABD and ER2. Scapular notching was reported in 3 shoulders (15.7%) in Lat/Ssc+ group and in 7 shoulders (50%) in Lat/Ssc- group, while it was reported in 4 shoulders (14.2%) in Med/Ssc + group and in 6 shoulders (42.8%) in Med/Ssc- group. Stress shielding was observed in 6 cases in Lat/Ssc+ group (31.6%), in 8 cases in Lat/Ssc- group (57.1%), in 3 cases (10.7%) in Med/Ssc + group and 4 cases in Med/Ssc- group (28.6%). CONCLUSIONS: Patients undergoing RSA show clinical improvements at mid-term follow-up with a low rate of complications, regardless of the use of a medialized or a lateralized humeral stem design. Ssc repair is associated with better functional outcomes in the cohort of medialized stem, while it did not yield significant differences in the cohort of lateralized stem. LEVEL OF EVIDENCE: Level III; Retrospective Cohort Comparison; Treatment Study.

Subscapularis repair for reverse shoulder arthroplasty: a systematic review and meta-analysis.

BACKGROUND: The purpose of this study is to perform a systematic review of the literature evaluating the importance of subscapularis repair in patients who underwent reverse shoulder arthroplasty (RSA). METHODS: A systematic search of articles in PubMed, EMBASE, and the Cochrane Library databases was carried out according to the PRISMA guidelines. Cohort studies comparing RSA with subscapularis repair vs. RSA without subscapularis repair were included. All statistical analysis was performed using Review Manager. A P value of <.05 was considered to be statistically significant. RESULTS: Seventeen studies with 2620 patients were included. Subscapularis repair resulted in less instability compared to without subscapularis repair (0.8% vs. 4.2%, P = .04), and there were no significant differences in rate of instability with lateralization (0.6% vs. 1.6%, P = .40), revision rates (2.6% vs. 3.9%, P = .62), and complication rates (7.7% vs. 4.9%, P = .21). Subscapularis repair had improved American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (83.6 vs. 80.2, P = .02) and Constant scores (72.6 vs. 68.9, P < .01) but there was not a significant difference in visual analog scale pain scores (1.2 vs. 1.6, P = .11). Subscapularis repair had a significant difference in forward flexion (140° vs. 137°, P = .04) and internal rotation score (5.5 vs. 4.6, P = .001); however, there was no significant difference in external rotation (35° vs. 35°, P = .80) and abduction (117° vs. 123°, P = .13). CONCLUSION: This study found that RSA with subscapularis repair demonstrated a reduction in the occurrence of implant instability with medialized implants. However, subscapularis repair did not yield improvements in revision rates, complications, or instability with lateralized implants. Additionally, other outcome measures such as ASES, Constant score, and range of motion exhibited statistically significant improvements with subscapularis repair but did not surpass clinically significant thresholds.

The effect of subscapularis-specific rehabilitation following total shoulder arthroplasty: a prospective, double-blinded, randomized controlled trial.

BACKGROUND: Patients undergoing a total shoulder arthroplasty (TSA) through a deltopectoral approach will require repair of the subscapularis tendon. There are no universal postoperative guidelines for rehabilitation of the subscapularis specifically. We hypothesize that the addition of a subscapularis-specific regimen will result in improved subscapularis strength and function. METHODS: Adult patients undergoing anatomic TSA for the treatment of primary glenohumeral osteoarthritis were included. Patients were randomized into either the traditional rehabilitation (TR) control group or the subscapularis rehabilitation (SR) group, which consisted of the traditional therapy along with early and additional subscapularis exercises. Baseline demographics, patient-reported outcome measures (PROMs), range of motion (ROM), provocative tests, and subscapularis strength using a handheld dynamometer were measured preoperatively at the initial clinic visit (ICV) as well as 3 months, 6 months, and 1 year postoperatively. The primary outcome of interest was a comparison of subscapularis strength between cohorts relative to preoperative baseline, whereas secondary outcomes were functional, ROM, and PROMs. RESULTS: Sixty-six patients were included in the final analysis (32 TR vs. 34 SR). There were no statistically significant differences between cohorts at the ICV with regard to demographics, baseline subscapularis strength, functional testing, or PROMs. All postoperative time points demonstrated similar subscapularis strength testing between TR and SR groups (P > .05). Additionally, peak and average subscapularis strength testing at 3, 6, and 12 months postoperatively were similar to baseline ICV testing in both groups. Both groups demonstrated improvements across several provocative tests, ROM, and PROM outcome metrics at every postoperative time point as compared to baseline ICV values (P < .05). CONCLUSIONS: Patients undergoing anatomic TSA return to baseline internal rotation strength by 3 months postoperatively and demonstrate significant improvements in function, ROM, and several patient-reported outcome measures. The addition of early and focused subscapularis strengthening exercises does not appear to significantly impact any outcomes when compared to traditional rehabilitation programs.

Biomechanical evaluation of subscapularis peel repairs augmented with the long head of the biceps tendon for anatomic total shoulder arthroplasty.

BACKGROUND: Subscapularis failure is a troublesome complication following anatomic total shoulder arthroplasty (aTSA). Commonly discarded during aTSA, the long head of the biceps tendon (LHBT) may offer an efficient and cheap autograft for the augmentation of the subscapularis repair during aTSA. The purpose of this study was to biomechanically compare a standard subscapularis peel repair to 2 methods of subscapularis peel repair augmented with LHBT. METHODS: 18 human cadaveric shoulders (61 ± 9 years of age) were used in this study. Shoulders were randomly assigned to biomechanically compare subscapularis peel repair with (1) traditional single-row repair, (2) single row with horizontal LHBT augmentation, or (3) single row with V-shaped LHBT augmentation. Shoulders underwent biomechanical testing on a servohydraulic testing system to compare cyclic displacement, load to failure, and stiffness. RESULTS: There were no significant differences in the cyclic displacement between the 3 techniques in the superior, middle, or inferior portion of the subscapularis repair (P > .05). The horizontal (436.7 ± 113.3 N; P = .011) and V-shape (563.3 ± 101.0 N; P < .001) repair demonstrated significantly greater load to failure compared with traditional repair (344.4 ± 82.4 N). The V-shape repair had significantly greater load to failure compared to the horizontal repair (P < .001). The horizontal (61.6 ± 8.4 N/mm; P < .001) and the V-shape (62.8 ± 6.1; P < .001) repairs demonstrated significantly greater stiffness compared to the traditional repair (47.6 ± 6.2 N). There was no significant difference in the stiffness of the horizontal and V-shape repairs (P = .770). CONCLUSIONS: Subscapularis peel repair augmentation with LHBT autograft following aTSA confers greater time zero load to failure and stiffness when compared to a standard subscapularis peel repair.

A biomechanical comparison of subscapularis tenotomy repair techniques for stemless shoulder arthroplasty.

BACKGROUND: One of the leading challenges for surgeons shifting to stemless anatomic total shoulder arthroplasty (TSA) is subscapularis repair. In the available literature reporting outcomes after stemless TSA, subscapularis tenotomy with side-to-side repair is the most common technique despite some concerns regarding this technique in the biomechanical and clinical literature. Accordingly, this study investigated subscapularis tenotomy repair with stemless TSA with 2 primary objectives: (1) to evaluate the subscapularis tendon dimensions with reference to subscapularis tenotomy to determine the amount of tendon remaining for side-to-side repair after shoulder arthroplasty and (2) to biomechanically compare 2 methods of subscapularis tenotomy repair after stemless TSA-side-to-side repair and anchor-based repair. METHODS: We used 12 male shoulder specimens for this study. To address our first objective, measurements were made to calculate the dimensions of the subscapularis tendon at the superior, middle, and inferior levels to determine the amount of tendon remaining after tenotomy. These specimens were then divided into 2 groups (n = 6 in each group) to biomechanically compare subscapularis tenotomy repair with (1) traditional side-to-side repair and (2) anchor-based repair. The shoulders then underwent biomechanical testing with primary outcomes including load to failure and cyclic displacement. RESULTS: The mean subscapularis tendon width measured from the medial insertion at the lesser tuberosity to the muscle-tendon junction varied depending on the level: 19.5 mm superiorly (95% confidence interval [CI], 16.2-22.8 mm); 18.3 mm at the midportion (95% CI, 13.6-23.0 mm); and 13.1 mm inferiorly (95% CI, 9.1-17.1 mm). With a tenotomy made 1 cm medial to the lesser tuberosity insertion, a mean of 3.1 mm of tendon remained medially at the inferior subscapularis, with one-third of specimens having no tendon left medially at this level. On comparison of tenotomy repair techniques, the anchor-based technique had a 57% higher ultimate load to failure compared with the side-to-side repair (448 N vs. 249 N, P < .001). There were no significant differences in cyclic displacement (6.1 mm vs. 7.1 mm, P = .751) and construct stiffness (38.1 N/mm vs. 42.9 N/mm, P = .461) between techniques. CONCLUSIONS: With traditional techniques for subscapularis tenotomy for anatomic TSA, there is very little tendon remaining inferiorly for side-to-side repair. When subscapularis tenotomy is performed for stemless TSA, a double-row anchor-based repair has a better time-zero ultimate load to failure compared with side-to-side repair.

The role of subscapularis repair following reverse shoulder arthroplasty: systematic review and meta-analysis.

PURPOSE: Inadequate subscapularis repair has been advocated as one of the contributing factors for dislocation in reverse total shoulder arthroplasty; nonetheless the need to restore the subscapularis tendon integrity is under debate. The aim of this systematic review was to answer the question: does subscapularis reattachment following reverse total shoulder arthroplasty improve joint stability, range of motion and functional scores? METHODS: The literature was systematically screened in accordance with PRISMA guidelines looking for papers evaluating clinical outcomes of reverse total shoulder arthroplasty in relation to the management of subscapularis tendon. Studies comparing clinical outcomes, complications and dislocation rate with or without subscapularis repair were included. Studies in which reverse total shoulder arthroplasty was performed for trauma or tumors were excluded. The methodology of included articles was scored with MINORS scale and the Risk of Bias was assessed adopting the ROBINS-I (Risk Of Bias In Non-randomized Studies of Interventions) developed by the Cochrane Group. A meta-analysis was also performed combining the studies to increase the sample size and hence the power to obtain meaningful data. RESULTS: The database search identified 1062 records, and 6 full-text articles were finally included. A total number of 1085 reverse total shoulder arthroplasty were assessed on. Except for one study, lateralized prosthetic designs have been used. Dislocation occurred in 0.8% (5/599 patients) of the patient with repaired subscapularis and in 1.6% (8/486 patients) of the tenotomized patients, and subscapularis repair was not associated with a higher risk of dislocation (pooled Peto OR: 0.496, 95% CI: 0.163 to 1.510, p = 0.217). Qualitative assessment revealed no differences in the range of motion and clinical scores. CONCLUSION: Subscapularis repair after reverse total shoulder arthroplasty produces no clinically meaningful benefits, particularly using lateralized prosthetic designs. Subscapularis re-attachment does not improve implant stability, nor increases range of motion or clinical scores. Given these results, keeping in mind the antagonistic effect of the repaired subscapularis on external rotation, no evidence lead to suggest subscapularis reattachment following reverse total shoulder arthroplasty with lateralized prosthetic designs.

Atrophy patterns in isolated subscapularis lesions.

BACKGROUND: While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. METHODS: Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. RESULTS: The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). CONCLUSION: Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

Influence of subscapularis stiffness with glenosphere lateralization on physiological external rotation limits after reverse shoulder arthroplasty.

BACKGROUND: Repair of the subscapularis following reverse shoulder arthroplasty (RSA) remains a controversial topic among surgeons. Poor rotator cuff muscle quality is associated with increased musculotendinous stiffness, and the subsequent effect of compromised tissue repair on RSA functional outcomes remains unclear. The objective was to investigate the influence of subscapularis stiffness together with glenoid component lateralization on pre- and postimpingement joint mechanics during external rotation after RSA. METHODS: A validated finite element model incorporating the Zimmer Trabecular Metal reverse system was used. The deltoid and subscapularis tendon were tensioned and wrapped around the joint prior to controlled shoulder external rotation. Baseline subscapularis stiffness, determined from cadaveric testing, was varied to 80%, 120% and 140% of baseline, to simulate a range of pliability associated with fatty infiltration and fibrosis. We evaluated the effects of varying subscapularis stiffness and the corresponding variation in joint tension with varying glenosphere lateralization (2, 4, and 10 mm) on the torque required to externally rotate the shoulder and the impingement/subluxation risk. RESULTS: Prior to any impingement, the torques required to externally rotate the shoulder ranged from 22-47 Nm across the range of parameters studied, with the greatest torques required for the 10-mm glenosphere lateralization. The impact of increasing subscapularis stiffness on torque requirements was most pronounced at the 10-mm lateralization, as well. A 20% increase in subscapularis stiffness necessitated a 7%-14% increase in preimpingement torque, whereas a 40% stiffness increase was associated with a 12%-27% increase in torque. Torque was proportional to lateralization. When lateralization was increased from 2 to 4 mm, the preimpingement torque increased by 10%-13%, whereas a 10-mm lateralization necessitated a 35%-62% torque increase relative to 2 mm of lateralization. Increased subscapularis stiffness did not limit impingement-free range of motion or substantially decrease postimpingement subluxation in this model. DISCUSSION: Mechanical gains achieved through lateralization may be hindered by increased torque demands, especially when a stiffer subscapularis is repaired. As lateralization increases subscapularis tension, greater torque is required to externally rotate the shoulder. The torque required for external rotation has been reported between 15-50 Nm. Subscapularis repair with the simulated increases in stiffness requires relative increases in torque that the reconstructed shoulder may not be able to physically produce to rotate the glenohumeral joint, particularly at 10-mm lateralization. These results suggest that subscapularis repair may not be indicated in cases where a lateralized glenoid component is used and the subscapularis is compromised.

Biomechanical evaluation of 2 techniques of repair after subscapularis peel for stemless shoulder arthroplasty.

BACKGROUND: Stemless anatomic total shoulder arthroplasty (TSA) has been gaining significant popularity but poses unique challenges for subscapularis repair. Tenotomy with side-to-side repair has been the most frequently reported technique for subscapularis repair with stemless TSA but has the poorest biomechanical properties, and clinical failures have been reported. There is limited biomechanical evidence evaluating other subscapularis repair techniques for stemless TSA. Therefore, the goal of this study was to investigate 2 additional techniques using a subscapularis peel for subscapularis repair with a stemless TSA. METHODS: We used 18 male cadaveric specimens to investigate the native subscapularis (n = 6) and 2 subscapularis repair techniques (n = 12) after stemless anatomic TSA (Eclipse). A subscapularis peel with double-row, knotless anchor-based repair (n = 6) was compared with a subscapularis peel with a "backpack" repair (n = 6). The specimens then underwent biomechanical testing, including cyclic displacement and load-to-failure testing. The mode of failure was also recorded. RESULTS: The native tendon had the highest ultimate load to failure (mean, 1017.1 N). Load to failure was similar between the 2 study groups: 397.9 N for the peel and backpack repair and 593.7 N for the knotless anchor-based repair (P > .05 for all comparisons). Moreover, no significant differences in cyclic displacement or construct stiffness were found between the groups (P > .05 for all comparisons). CONCLUSIONS: A double-row, knotless anchor-based repair of a subscapularis peel for stemless anatomic shoulder arthroplasty has similar biomechanical properties to a backpack repair technique; however, both techniques fail to reproduce the native biomechanical properties at time zero.

The V-shaped subscapularis tenotomy for anatomic total shoulder arthroplasty.

PURPOSE: 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. METHODS: A retrospective study of patients who underwent primary TSA with VT over a three year 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. RESULTS: 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. CONCLUSION: 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.

Clinically significant subscapularis failure after anatomic shoulder arthroplasty: is it worth repairing?

BACKGROUND: Symptomatic subscapularis (SC) failure after anatomic total shoulder arthroplasty (TSA) is difficult to treat. The purpose of this study was to determine the outcomes of reoperation for SC failure. METHODS: All patients undergoing reoperation for SC failure after TSA were identified from a single-institution database. Patients underwent either revision SC repair or revision to reverse shoulder arthroplasty. At a minimum of 1 year after reoperation, complications, reoperations, and functional outcomes were collected. RESULTS: Patients who initially underwent SC repair were significantly younger than patients who underwent revision to reverse shoulder arthroplasty (mean age, 59.3 years vs. 70.3 years; P = .004), had a better comorbidity profile (mean Charlson Comorbidity Index, 2.2 vs. 3.6; P = .04), and had a more acute presentation (mean time between injury and surgery, 9.1 weeks vs. 28.5 weeks; P = .03). Patients who underwent SC repair also had a significantly higher reoperation rate (52.9% vs. 0.0%, P = .01). At final follow-up, functional outcomes scores and patient satisfaction rates were not significantly different between treatment groups. DISCUSSION: Decision making on how to treat patients with SC failure following TSA remains challenging and should be individualized to the patient's age, level of activity, comorbidities, timing and mechanism of SC failure, and functional expectations.

Do individualized humeral retroversion and subscapularis repair affect the clinical outcomes of reverse total shoulder arthroplasty?

BACKGROUND: This study aimed to evaluate the effects of an individualized angle of humeral retroversion and subscapularis repair on clinical outcomes after reverse total shoulder arthroplasty (RTSA) using a lateralized prosthesis. METHODS: A retrospective analysis of 80 patients who underwent RTSA and had a minimum of 2 years' follow-up was performed. Individualization was based on the native retroversion angle, quantified from computed tomography images. Clinical outcomes (forward flexion, external rotation at the side, internal rotation at the back, functional scores, and pain) were compared between patients with individualized retroversion (group I, n = 52) and patients with a fixed retroversion angle of 20° (group II, n = 28). Group I was further subdivided into patients with a retroversion angle of 20° or less (subgroup A, n = 21) and patients with a retroversion angle greater than 20° (subgroup B, n = 31). We also compared outcomes in group I between patients with (n = 40) and without (n = 12) subscapularis repair. RESULTS: Ranges of motion including external rotation and internal rotation, functional scores, and pain relief were significantly better in group I than in group II (P < .05 for all). No differences in clinical outcomes were found between subgroups A and B, although outcomes for both of these subgroups were better than those for group II (P < .05 for all). Subscapularis repair was not correlated with superior clinical outcomes. CONCLUSIONS: Individualized humeral retroversion may provide superior clinical outcomes to those of implantation of the humeral component at a fixed angle of 20° of retroversion. Repair of the subscapularis may not be essential for superior clinical outcomes in patients treated using a lateralized RTSA prosthesis.

Arthroscopic anatomy medial to the coracoid: an anatomic study of the axillary and musculocutaneous nerves.

PURPOSE: The purpose of this study was to provide arthroscopic measurements and orientations of the axillary and musculocutaneous nerves medial to the coracoid. METHODS: A retrospective chart review of 29 patients undergoing arthroscopic subscapularis repair and arthroscopic cadaveric dissection of 23 shoulders was used to analyze neuroanatomical distances to arthroscopic landmarks and to document the orientations of the axillary and musculocutaneous nerves using a clock face analogy. The clock face data was analyzed by separating the clock face into four quadrants and the frequency of any crossing nerve within each of the four quadrants was then determined. RESULTS: In vivo, the axillary nerve was found 1.5 ± 0.5 cm medial to the coracoid tip and the musculocutaneous nerve was found 1.6 ± 0.6 cm medial to the coracoid tip. In cadavera, the axillary nerve was found 2.0 ± 0.6 cm medial to the coracoid tip and the musculocutaneous nerve was found 1.5 ± 0.5 cm medial to the coracoid tip. The posterosuperior quadrant of the subcoracoid space contained a crossing nerve in 4 of 29 (13.8%) patients undergoing arthroscopic rotator cuff repair medial to the coracoid, compared to 9 of 23 (39.1%) cadavera undergoing arthroscopic dissection medial to the coracoid. The posteroinferior quadrant contained a crossing nerve in 16 of 29 (55.2%) patients compared to 17 of 23 (73.9%) cadavera. CONCLUSIONS: The axillary and musculocutaneous nerves run in close proximity to the coracoid tip and coracoid arch, most consistently within 1-2 cm medial to these structures, which is closer than has been previously documented in the literature. Crossing nerves are least frequently encountered within the posterosuperior quadrant of the subcoracoid space medial to the coracoid, followed by the posteroinferior quadrant. Arthroscopic dissection of this space should begin in the posterosuperior quadrant and carefully progress to the posteroinferior quadrant to decrease the risk of intraoperative nerve injury. Given the close proximity and frequently encountered nerves in this area, extreme caution must be exercised when working arthroscopically within the subcoracoid space.

The effect of subscapularis repair on dislocation rates in reverse shoulder arthroplasty: a meta-analysis and systematic review.

BACKGROUND: Reverse total shoulder arthroplasty is an effective treatment for patients with rotator cuff arthropathy; however, complication rates are relatively high (19%-50%), with implant instability and infection being particularly devastating to overall outcomes. The objective of this study was to analyze the highest level of data comparing dislocation rates and outcomes in reverse total shoulder arthroplasty with and without the subscapularis tendon repaired. METHODS: The databases MEDLINE, Embase, and CINAHL were searched using a sensitive search strategy for this meta-analysis/systematic review. Eligibility included any studies in which patients were treated with a reverse total shoulder arthroplasty in which the status of the subscapularis tendon could be determined. A data extraction form was developed to collect select data from the included studies. A meta-analysis was performed on pooled data of 5 studies comparing dislocation rates and 3 studies comparing postoperative forward elevation, rate of infection, overall complication rates, and fractures. RESULTS: Two independent researchers reviewed 1008 studies. Seven studies met inclusion criteria. A meta-analysis was performed on all level III studies, resulting in 1306 patients being analyzed. Results demonstrated lower dislocation rates in the subscapularis repair group (odds ratio, 0.19; P < .001). However, in patients without a subscapularis repair, lateralized center of rotation (COR) resulted in a significantly lower dislocation rate compared with medialized COR (odds ratio, 0.24; P < .001). CONCLUSION: The results of our meta-analysis of the available data demonstrated a decrease in dislocation risk when the subscapularis tendon was repaired in medialized and lateralized designs. When subscapularis repair is not performed, lateralized COR, regardless of humeral socket design, may reduce the dislocation rates.

Microbial colonization of subscapularis tagging sutures in shoulder arthroplasty: a prospective, controlled study.

BACKGROUND: Reducing intraoperative wound contamination is a critical preventive strategy for reducing the risk of prosthetic joint infection in shoulder arthroplasty. The aim of this study was to investigate the potential microbial colonization of subscapularis tagging sutures during shoulder arthroplasty. METHODS: In this prospective study, 50 consecutive patients undergoing primary shoulder arthroplasty (anatomic or reverse) were enrolled. Patients with revision shoulder arthroplasty and proximal humeral fractures were excluded. Nonabsorbable, braided tagging sutures were placed through the subscapularis tendon prior to tenotomy. A similar nonabsorbable, braided suture (control) was placed in a sterile container on the back table, open to the operating room environment. Subscapularis tagging sutures (experimental specimens) and control sutures were collected prior to subscapularis tenotomy repair and submitted for aerobic and anaerobic cultures. Cultures were held for 21 days to account for extended growth of slow-growing bacteria. RESULTS: A total of 12 of 50 experimental and 16 of 50 control sutures had positive cultures. Staphylococcus epidermidis and Cutibacterium acnes were the 2 most commonly isolated organisms. Active tobacco use (P = .038) and procedure length (P = .03) were significantly associated with positive cultures. No significant association between positive subscapularis tagging suture cultures and positive control cultures was found (P = .551). Patient age, sex, body mass index, and significant medical comorbidities were not significantly associated with positive cultures. DISCUSSION: Subscapularis tagging sutures are a potential source of microbial contaminant in shoulder arthroplasty, and we recommend exchanging the tagging suture with a suture opened immediately prior to subscapularis repair.

Isolated lesions of the lower subscapularis tendon: diagnosis and management.

PURPOSE: Isolated lesions of the caudal portion of the subscapularis (SSC) tendon are rare and have not been subject of major attention in the literature yet. However, these lesions can lead to tremendous impairment of shoulder function. The purpose of the present study was to raise clinician's awareness for these "hidden lesions" and to present the crucial steps for diagnosis and management. METHODS: Five patients (three men, two women; mean age 40) with traumatic isolated caudal SSC lesion were enrolled in the present study. After clinical and radiological examination, all patients underwent diagnostic arthroscopy and open inferior SSC repair. The results of the clinical and radiological examination were documented along with the intraoperative findings. Post-operative pain level and shoulder function were assessed. RESULTS: In all patients the SSC lesion could be detected clinically. In two patients the caudal SSC tear was diagnosed delayed after initial conservative treatment. Preoperatively, all patients showed restricted active movement of the shoulder with positive clinical tests for the SSC. All SSC lesions could be detected on MR images and identified arthroscopically. After a mean follow-up of 12 months, all clinical SSC tests were negative, and the patients have almost regained preinjury shoulder function. The mean post-operative pain score (VAS) was 1 (range 0-1), and the mean ASES score was 93.3 (range 91.6-95). CONCLUSION: Arthroscopic visualization of the SSC tendon is incomplete rendering caudal SSC tears difficult to detect and easy to overlook. Clinicians' awareness of this pathology along with accurate clinical and radiological examination leads to the correct diagnosis. Open caudal SSC repair provides pain relief and reliable shoulder function after short-term follow-up. LEVEL OF EVIDENCE: IV.

Primary reverse total shoulder arthroplasty outcomes in patients with subscapularis repair versus tenotomy.

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) is now performed at nearly the same rate as anatomic total shoulder arthroplasty in the United States. Repair of the subscapularis is of vital importance in total shoulder arthroplasty; however, its utilization in RTSA has recently been questioned. METHODS: This is a retrospective comparative study from prospectively collected data comparing the outcomes and complications after primary RTSA with or without subscapularis repair. The study includes 202 patients who underwent primary RTSA at a single institution by a single surgeon using the same implant between 2007 and 2012. Average clinical follow-up was greater than 3 years in both groups. Outcome scores, clinical range-of-motion and strength measurements, and complications including dislocations are reported. RESULTS: At an average follow-up of greater than 3 years, there were no significant differences in clinical range of motion, strength, and rates of complications including dislocations. External rotation was 24° in the subscapularis repair group and 26° in the no-repair group. There were no differences in the American Shoulder and Elbow Surgeons shoulder score. Subjective measures included the Shoulder Pain and Disability Index; University of California, Los Angeles shoulder rating scale; Simple Shoulder Test; and normalized Constant outcome scores. There were 0 dislocations (0%) in the subscapularis repair group and 3 dislocations in the no-repair group (2.6%), which were not significantly different. CONCLUSION: Primary RTSAs with or without subscapularis repair have similar clinical outcome scores, range of motion, strength, and rates of complications including dislocations at 3 years of follow-up.

Biomechanical effects of rotator interval closure in shoulder arthroplasty.

BACKGROUND: Subscapularis dysfunction remains a significant problem after shoulder arthroplasty. Published techniques have variable recommendations for placing a rotator interval closing suture in attempts to off-load the subscapularis repair site, the implications of which have yet to be examined in the literature. The goals of this study were to investigate the biomechanical benefit of the rotator interval closing suture on the subscapularis repair strength and to analyze the effect on shoulder range of motion. METHODS: Sixteen matched cadaveric shoulders underwent a subscapularis tenotomy and shoulder arthroplasty. The subscapularis tenotomy was repaired, and motion at physiologic torsional force was recorded. One of each matched pair was randomly assigned to receive an additional rotator interval closure suture. Each specimen then underwent a standardized cyclic loading with measurement of gap formation and load to failure. RESULTS: The rotator interval closing suture significantly increased the ultimate load to failure of the subscapularis repair (452 N vs. 219 N; P = .002) and decreased gap formation at the subscapularis repair site. Measurement of the shoulder motion showed no significant difference between shoulders with and without the rotator interval closing suture. DISCUSSION: We report the additional biomechanical benefit that the rotator interval closing suture provides to the subscapularis repair site after shoulder arthroplasty. This suture acts to improve the load to failure of the subscapularis repair and to decrease gap formation under cyclic load. Furthermore, it does not detrimentally affect shoulder external rotation or overall arc of rotation. Our findings support the application of this off-loading technique after subscapularis repair during shoulder arthroplasty.

Effect of lesser tuberosity osteotomy size and repair construct during total shoulder arthroplasty.

BACKGROUND: Lesser tuberosity osteotomy has been shown to decrease postoperative subscapularis dysfunction. The purpose of this study was to determine the effect of osteotomy thickness and suture configuration on repair integrity. MATERIALS AND METHODS: One side of 12 matched-pair cadaveric shoulders was randomly assigned to either a thick osteotomy (100% of lesser tuberosity height) or a thin osteotomy (50% of height). Both sides of the matched pairs were given the same repair, either (1) compression sutures or (2) compression sutures plus 1 tension suture. This created 4 groups of 6 paired specimens. Computed tomography imaging was used to measure tuberosity dimensions before and after osteotomy to validate fragment height and area. The repairs were loaded cyclically and then loaded to failure. A video system measured fragment displacement. The percent area of osteotomy contact was calculated from the computed tomography and displacement data. RESULTS: The average initial displacement was less in the thin osteotomy groups (P = .011). Adding a tension suture negated this difference. A significant number of thin repair sites compared with thick repair sites remained intact during load-to-failure testing (P = .001). No difference occurred because of maximum load between the repair groups (P = .401), and construct stiffness was greater when a tension suture was used (P = .032). The percent area of osteotomy contact showed no differences between the osteotomy (P = .431) and repair (P = .251) groups. CONCLUSION: The study showed that thin osteotomies displaced less than thick osteotomies. Adding a tension band improved construct stability and eliminated some failure modes. Our ideal repair was a thin wafer with both tension and compression sutures. This construct had smaller total displacement, a high osteotomy percent contact area, and a high maximum load.