Outcomes for subscapularis management techniques in shoulder arthroplasty: a systematic review

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.

Lesser Tuberosity Osteotomy for the Management of the Subscapularis During Total Shoulder Arthroplasty

Subscapularis integrity is critical after anatomic total shoulder arthroplasty, with failure leading to potential instability, loss of function, and revision surgery. The three well-described subscapularis mobilization techniques during total shoulder arthroplasty include tenotomy, peel, and lesser tuberosity osteotomy (LTO). While several comparative studies exist, the optimal approach remains controversial. LTO has been associated with the highest healing rates, but techniques and repair constructs are highly variable. The purpose of this article was to provide an overview of LTO with attention on radiographic assessment, repair options, and clinical outcomes.

Early rehabilitation after reverse total shoulder prosthesis on fracture of proximal humerus in elderly patients provides better functional outcome

PURPOSE

Reverse total shoulder arthroplasty (RSA) has revolutionized the management of proximal humerus fractures (PHF) in the elderly patients. There is few or no consensus regarding to management of postoperative rehabilitation in elderly patients. An early rehabilitation from D1 allowed better functional results compared to rehabilitation started to D30 independently from tuberosities consolidation.

METHODS

94 patients operated on for PHF were evaluated retrospectively, with a minimum radio-clinical follow-up of 2 years. Clinical evaluation included mobilities and four functional scores: ASES, quick DASH, gross constant, weighted constant. Radiological evaluation was performed on a frontal shoulder X-ray with evaluation of tuberosities' consolidation.

RESULTS

The mean follow-up was 45 ± 19 months (24-88 months). Early rehabilitation was significantly associated with a better Constant Score (71.1 ± 17.2 vs. 56.4 ± 15.8; p < 0.001), better adjusted Constant score (92.4 ± 14.2 vs. 80.3 ± 19.5; p < 0.001), better quick DASH (22.8 ± 19.8 vs. 36.7 ± 21.3; p < 0.01), better ASES (78.6 ± 20.2 vs. 63 ± 22; p < 0.001).

CONCLUSION

In traumatology, functional result of RSA seems not related in tuberosities' union but in rehabilitation in order to limit postoperative stiffness of operated shoulder. An early rehabilitation is related with better clinical and functional results, independently of tuberosities' union.

LEVEL OF EVIDENCE

3, control-case study.

Anatomic glenohumeral arthroplasty: State of the art

Anatomical total shoulder arthroplasty in its modern form where it reproduces the normal shoulder has been utilized clinically for more than half a century. As the technology and the designs have changed to recreate the humeral and glenoid sides of the joint, the sophistication of design has resulted in the growing number of cases annually worldwide. This increase is due in part to the increasing number of indications that the prosthesis can treat with successful results. On the humeral side, there have been design changes to better reflect the proximal humeral anatomy, and humeral stems are increasingly placed safely without cement. Platform systems which allow conversion of a failed arthroplasty to a reverse configuration without stem extraction is another design change. Similarly, there has been increasing utilization of short stem and stemless humeral components. Extensive experience with shorter stem and stemless devices, however, has yet to demonstrate the purported advantages of these devices, as recent studies have demonstrated equivalent blood loss, fracture rates, operative times, and outcome scores. Easier revision with these shorter stems remains to be definitively established, with only one study comparing the ease of revision between stem types. On the glenoid side, hybrid cementless glenoids, inlay glenoids, cementless all-polyethylene glenoids, and augmented glenoids have all been investigated; however, the indications for these devices remain unclear. Lastly, innovative surgical approaches to implanting shoulder arthroplasty and the use of patient specific guides and computerized planning, while interesting concepts, still await validation before they are utilized on a widespread basis. While reverse shoulder arthroplasty has been increasingly used to reconstruct the arthritic shoulder, anatomic glenohumeral replacement maintains a significant role in the armamentarium of the shoulder surgeon.

Subscapularis management in anatomic total shoulder arthroplasty: A systematic review and network meta-analysis

Background

This systematic review and network meta-analysis compare clinical outcomes of three different subscapularis management techniques in anatomic total shoulder arthroplasty: lesser tuberosity osteotomy, subscapularis peel, and subscapularis tenotomy.

Methods

PubMed, Web of Science, Embase, and Cochrane's trial registry were searched in July 2021. Comparative studies and case series evaluating the outcomes of these three techniques were included. The network meta-analysis was performed only on comparative studies.

Results

Twenty-three studies were included. Both lesser tuberosity osteotomy and subscapularis peel had significantly higher Western Ontario Osteoarthritis Scores compared to subscapularis tenotomy, but no difference in American Shoulder and Elbow Society Scores. Subscapularis peel had superior external rotation compared to lesser tuberosity osteotomy. However, no difference was found in external rotation between subscapularis peel and subscapularis tenotomy or between subscapularis tenotomy and lesser tuberosity osteotomy. The overall weighted average for lesser tuberosity osteotomy bony union was 93.6%, whereas the overall weighted average for subscapularis tendon healing was 79.4% and 87% for subscapularis tenotomy and subscapularis peel, respectively.

Discussion

This network meta-analysis demonstrated that lesser tuberosity osteotomy and subscapularis peel were associated with the high union and subscapularis healing rates and may be associated with improved shoulder function and quality of life, compared to subscapularis tenotomy. Lesser tuberosity osteotomy and subscapularis peel demonstrate a trend of superior outcomes compared to subscapularis tenotomy during anatomic total shoulder arthroplasty.

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.

Lesser Tuberosity Osteotomy Healing in Stemmed and Stemless Anatomic Shoulder Arthroplasty Is Higher with a Tensionable Construct and Affected by Body Mass Index and Tobacco Use

BACKGROUND

This study compared the healing rates of lesser tuberosity osteotomy (LTO) for anatomic total shoulder arthroplasty (TSA), repaired with either standard knot tying or a tensionable construct. Second, we evaluated LTO healing in stemmed and stemless prostheses and identified the patient characteristics associated with healing.

METHODS

An analysis of consecutive primary TSAs approached with an LTO performed by a single surgeon between 2016 and 2020 was conducted. In the first two years of the study period, the LTOs were repaired with four #2 polyblend sutures passed through drill tunnels and around a short press-fit stem, followed by manual knot tying. Subsequently, a tensionable construct with suture tapes (TCB) was universally adopted. The radiographic appearance of the LTO was evaluated at a minimum of six months postoperatively.

RESULTS

A total of 340 patients met the study criteria, including 168 with manual knot tying, 84 TCB repairs with a stemmed implant, and 88 TCB repairs with a stemless implant. There was no difference in the baseline demographics between the groups. The LTO healing rate of the manual knot tying group (85%) was lower than that of the stemmed (95%) and stemless (98%) TCB groups (p < 0.001). When directly comparing the LTO healing between the stemmed and stemless TCB groups, the differences were not significant (p = 0.44). Across all constructs, the body mass index (BMI) was higher in the displaced nonunion group (p = 0.04), with a failure rate of 9.4% for a BMI between 30 and 40, 12.5% for a BMI between 40 and 50, and 28.6% for a BMI > 50. The rate of tobacco use was higher in the displaced nonunion group (p = 0.037).

CONCLUSION

A tensionable construct improves LTO healing compared to manual knot tying, irrespective of the implant type. In addition to the surgical technique, the patient factors that influence tuberosity healing include a greater BMI and tobacco use.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Functional internal rotation is similar between lesser tuberosity osteotomy and subscapularis peel in total shoulder arthroplasty: short-term follow-up

INTRODUCTION

Lesser tuberosity osteotomy (LTO) and subscapularis peel (Peel) are 2 common techniques used to mobilize the subscapularis tendon during anatomic total shoulder arthroplasty (TSA). The literature is inconclusive over which technique is optimal; thus, controversy exists over which technique should be performed. The purpose of this study was to compare specific functional internal rotation tasks and general outcome scores in TSA patients who received either an LTO or Peel.

METHODS

A retrospective review of 563 patients treated with primary TSA using either an LTO (n = 358) or Peel (n = 205) with a minimum 2-year follow-up was performed. Subjective internal rotation, active internal rotation, and specific questions related to functional internal rotation isolated from the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgeons functional questionnaires were reviewed. Other outcome scores including visual analog scale pain and function, Single Assessment Numerical Evaluation, SST, American Shoulder and Elbow Surgeons, and revision rates were compared between the 2 groups.

RESULTS

The study found no difference in postoperative functional internal rotation and range of motion between LTO and Peel. Patients who received a Peel were shown to have a slightly greater improvement in the ability to perform toileting and a higher average change in SST score that did not reach clinical significance. There was no difference in the percentage of maximal improvement, revision rate, or need for revision between the 2 groups.

CONCLUSION

No difference was found between the LTO and Peel techniques in regard to functional tasks of internal rotation at short-term follow-up.

Compressed autograft biceps tendon augmentation of subscapularis repair following shoulder arthroplasty

Subscapularis integrity is correlated with function following shoulder arthroplasty. Failure of healing, particularly following anatomic total shoulder arthroplasty, is associated with poor outcomes and the need for revision. Graft augmentation has been used to increase healing following rotator cuff repair but has not been commonly advocated for augmenting the subscapularis following shoulder arthroplasty. The long head biceps tendon is typically tenodesed and discarded during shoulder arthroplasty. Rather than discarding the tendon, the tendon may be compressed and applied to the subscapularis as a biologic scaffold to potentially improve subscapularis healing following shoulder arthroplasty.

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.

Zimmer Z, Gilotra MN. Reliability, validity, and responsiveness of a novel subscapularis outcome score: The Baltimore Orthopedic Subscapularis Score

Background

Available surveys that evaluate shoulder strength and pain often combine rotator cuff muscles making the test unable to differentiate subscapularis tears from other pathology including concomitant supraspinatus, infraspinatus tears. The purpose of this study was to validate a subscapularis-specific shoulder survey (Baltimore Orthopedic Subscapularis Score) as a viable clinical outcome assessment through analysis of psychometric properties.

Methods

A 5-question survey was given to a study population of 390 patients, 136 of whom had full thickness rotator cuff tears with a minimum score of 5 (better) and a maximum score of 25 (worse). Surveys were given during the initial consultation, preoperative visit, and postoperative visit. Content validity, construct validity, test-retest reliability, responsiveness to change, internal consistency, and minimal clinically important difference using distribution and anchor-based methods were determined for our subscapularis function survey.

Results

A high correlation was reported on test-retest reliability (intraclass correlation coefficient = 0.89). An acceptable internal consistency was reported for all patients surveyed (Cronbach alpha = 0.91). Floor and ceiling effects for patients with rotator cuff pathology were minimized (1% for both). Patients with an isolated subscapularis tear scored worse than supraspinatus/infraspinatus tears and exhibited similar dysfunction as patients with a supraspinatus/infraspinatus/subscapularis tear. An acceptable construct validity was reported with subscapularis-involved tears demonstrating higher scores with significance (P < .05). There was excellent responsiveness to change with a standardized response mean of 1.51 and effect size of 1.27 (large > 0.8). The minimal clinically important difference using a distribution and anchor-based method was 4.1 and 4.6, respectively. Among patients with rotator cuff tears in this population, a score of 22 or higher predicts a subscapularis tear 75% of the time, in spite of its low overall prevalence.

Conclusion

The subscapularis shoulder score demonstrated acceptable psychometric performance for outcomes assessment in patients with rotator cuff disease. This survey can be used as an effective clinical tool to assess subscapularis function.

Lesser Tuberosity Osteotomy Combined with Anteroinferior Capsulectomy for Anatomic Shoulder Arthroplasty

Adequate subscapularis tendon mobilization and glenoid exposure are critical to a successful anatomic total shoulder arthroplasty. A lesser tuberosity osteotomy allows for direct bone-to-bone healing while maintaining the strong tendon-to-bone attachment of the subscapularis tendon insertion. Excision of the typically thickened and contracted anteroinferior capsule in osteoarthritic shoulders can help mobilize the subscapularis, theoretically allowing for optimal soft-tissue balance, decreased tension on the subscapularis repair, improved glenoid exposure, and anatomic repair. In this Technical Note and accompanying video, we describe our technique for lesser tuberosity osteotomy with anteroinferior capsulectomy for anatomic total shoulder arthroplasty. This technique reliably and reproducibly produces good results in terms of glenoid exposure, soft-tissue balance, and postoperative subscapularis function.

Lesser Tuberosity Osteotomy Does Not Appear to Compromise Fixation or Function Compared With Peel in Short-Stem Anatomic Shoulder Arthroplasty

Several methods are available for subscapularis management in total shoulder arthroplasty (TSA). The goal of this study was to compare radiographic and clinical outcomes of short-stem TSA stratified by subscapularis management technique. A multicenter trial was completed evaluating primary short-stem TSA performed with a subscapularis peel (n=80) or lesser tuberosity osteotomy (LTO) (n=59). The primary outcome measure was subscapularis function, as measured by internal rotation and strength at 1 year postoperatively. Secondary outcomes included patient-reported outcomes, radiographic changes, and implant loosening. Patients in the peel group obtained better active internal rotation by spinal level (P=.004). No difference was seen between groups for internal rotation with 90° shoulder abduction (P=.862) or belly press (P=.903). Statistically significant improvements in functional outcomes were seen without clinical differences. Radiographic changes showed no difference in stem shift, subsidence, or at-risk loosening rate. Anterior subluxation of the humerus was observed among 2% of the LTO group vs 17% of the peel group (P=.006). At short-term follow-up, those in the peel group appear to have a better final spinal level of internal rotation, whereas those in the LTO group have a significantly lower rate of anterior humeral subluxation. Both LTO and subscapularis peel appear safe for short-stem TSA, with no radiographic evidence of loosening. [Orthopedics. 2022;45(3):151-155.].

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.

Biomechanics of anatomic and reverse shoulder arthroplasty

The biomechanics of the shoulder relies on careful balancing between stability and mobility. A thorough understanding of normal and degenerative shoulder anatomy is necessary, as the goal of anatomic total shoulder arthroplasty is to reproduce premorbid shoulder kinematics.With reported joint reaction forces up to 2.4 times bodyweight, failure to restore anatomy and therefore provide a stable fulcrum will result in early implant failure secondary to glenoid loosening.The high variability of proximal humeral anatomy can be addressed with modular stems or stemless humeral components. The development of three-dimensional planning has led to a better understanding of the complex nature of glenoid bone deformity in eccentric osteoarthritis.The treatment of cuff tear arthropathy patients was revolutionized by the arrival of Grammont's reverse shoulder arthroplasty. The initial design medialized the centre of rotation and distalized the humerus, allowing up to a 42% increase in the deltoid moment arm.More modern reverse designs have maintained the element of restored stability but sought a more anatomic postoperative position to minimize complications and maximize rotational range of motion. Cite this article: EFORT Open Rev 2021;6:918-931. DOI: 10.1302/2058-5241.6.210014.

Cemented versus uncemented fixation of second-generation Trabecular Metal glenoid components: minimum 5-year outcomes

BACKGROUND

Total shoulder arthroplasty (TSA) with second-generation Trabecular Metal™ implants (Zimmer, Warsaw, IN, USA) has shown good short-term outcomes. Differences in outcomes between cemented and uncemented fixation are unknown. This study compared the clinical, radiographic, and patient-rated outcomes of TSA with cemented vs. uncemented TM glenoids at minimum 5-year follow-up.

METHODS

Patients who underwent anatomic TSA with second-generation TM glenoid components for primary osteoarthritis were identified for minimum 5-year follow-up. The patients were divided into 2 groups: cemented and uncemented glenoid fixation. Outcome measures included implant survival, patient-rated outcome scores (Patient-Reported Outcomes Measurement Information System [PROMIS] and American Shoulder and Elbow Surgeons scores), shoulder range of motion, and radiographic analysis. Findings were compared between groups.

RESULTS

The study included 55 shoulders: 27 in the cemented group (21 with full radiographic follow-up) and 28 in the uncemented group (22 with full radiographic follow-up). Both groups had similar follow-up times (6.6 years in cemented group vs. 6.7 years in uncemented group, P = .60). Moreover, the groups did not differ significantly in sex composition, age at the time of surgery, or preoperative Walch glenoid grade distribution. No patients required revision surgery. The 2 groups had similar preoperative range of motion, but patients in the uncemented group had greater follow-up forward flexion (P = .03), external rotation (P < .01), and lateral elevation (P = .03) than did patients in the cemented group. PROMIS scores were not significantly different between groups. American Shoulder and Elbow Surgeons scores were similar (89.8 in cemented group vs. 94.1 in uncemented group, P = .21). Mid-term radiographs showed a metal debris rate of 24% in the cemented group and 27% in the uncemented group. Although these values were not significantly different (P = .90), the frequency of mild metal debris (grade 1-2), when present, was greater in the uncemented group (grade 2 in 6 shoulders) than in the cemented group (grade 1 in 4 and grade 2 in 1, P = .02). There was a greater presence of mild (grade 1) radiolucent lines in the uncemented group (64%) than in the cemented group (29%, P < .01). No glenoid had evidence of loosening (defined by a change in position or radiolucent lines > 2 mm). The presence of metal debris and radiolucent lines did not have a significant effect on clinical outcomes.

CONCLUSION

At minimum 5-year follow-up, TSA patients with TM glenoids demonstrated excellent clinical and patient-reported outcomes with a 100% implant survival rate, regardless of cemented vs. uncemented fixation. However, the uncemented group showed a significantly higher rate of radiolucent lines and a higher frequency of mild metal debris. These radiographic findings did not affect the clinical outcomes, and their implications for long-term outcomes and prosthesis survival is unknown.

Subscapularis-sparing approaches in shoulder arthroplasty: A systematic review

Background

Novel approaches for anatomic and reverse total shoulder arthroplasty (aTSA and rTSA) that spare the subscapularis (SSC) have recently been described. Outcomes for the SSC-sparing approach were evaluated through this systematic review.

Methods

Medline, Embase, PubMed, and CENTRAL were searched.

Results

From 2051 citations, 8 studies were included (aTSA group, n = 241; rTSA group, n = 68). SSC-sparing aTSA and rTSA were associated with significant postoperative improvements in shoulder function and range of motion at 12- to 24-month follow-up.

Conclusion

The SSC-sparing approach may provide a safe alternative for up to two years post-surgery. Evidence for long-term use remains inconclusive.

The Lesser Tuberosity Osteotomy Exposure for Total Shoulder Arthroplasty

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.

Distal tibia allograft glenoid reconstruction for shoulder instability: outcomes after lesser tuberosity osteotomy

BACKGROUND

Distal tibia allograft reconstruction of the glenoid in shoulder instability has garnered significant attention over the last decade. Prior studies demonstrate significant improvement in all reported patient outcomes albeit the approach is through a subscapularis split. There have not been prior studies evaluating outcomes after lesser tuberosity osteotomy which provides excellent exposure to the anterior glenoid.We hypothesize there is significant improvement in functional outcomes and no deleterious effects after lesser tuberosity osteotomy for distal tibia allograft reconstruction of the glenoid for shoulder instability.

METHODS

A retrospective review was performed from 2016 of 2019 of patients undergoing distal tibia allograft reconstruction of the glenoid through a lesser tuberosity osteotomy. Patients were indicated if they had recurrent anterior shoulder instability with >20% glenoid bone loss and evidence of an off-track lesion. Clinical, imaging, and operative data were evaluated. Objective follow-up data evaluated at minimum 2 years included radiographs, range of motion, DASH, SANE, VAS, SST, ASES, and Constant scores.

RESULTS

A total of 12 patients were available with average follow-up 28 months, average age 26 years old, and average glenoid bone loss of 33%. The patients demonstrated significant improvement in their clinical outcomes at final follow-up: DASH 42.9-8.9 (P = .004), SANE 32.2-85 (P = .00005), VAS 4.6-1.1 (P = .003), SST 7-11.4 (P = .01), ASES 50.2-90.5 (P = .001), and Constant 37.6-86.2 (P = .01). Range of motion at final follow-up was forward flexion to 161.4° (135-170°), external rotation 49.5° (40-65°), and internal rotation to T12-L1 (T7-L2) vertebral body.

CONCLUSION

The present study demonstrates the effectiveness of a lesser tuberosity osteotomy in exposure of the glenoid for reconstruction with a distal tibia allograft. The functional integrity of the subscapularis is maintained and the patient-reported outcomes are comparable with current literature.

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.

The American Society of Shoulder and Elbow Therapists' consensus statement on rehabilitation for anatomic total shoulder arthroplasty

Anatomic total shoulder arthroplasty is the gold standard shoulder replacement procedure for patients with an intact rotator cuff and sufficient glenoid bone to accommodate prosthetic glenoid implant and offers reliable patient satisfaction, excellent implant longevity, and a low incidence of complications. Disparity exists in the literature regarding rehabilitation strategies following anatomic total shoulder arthroplasty. This article presents a consensus statement from experts in the field on rehabilitation following anatomic total shoulder arthroplasty. The goal of this consensus statement is to provide a current evidence-based foundation to inform the rehabilitation process after anatomic total shoulder arthroplasty. These guidelines apply to anatomic total shoulder arthroplasty (replacement of the humeral head and glenoid), hemiarthroplasty (replacing only the humeral head), and hemiarthroplasty with glenoid reaming or resurfacing. The consensus statement integrates an extensive literature review, as well as survey results of the practice patterns of members of the American Society of Shoulder and Elbow Therapists and the American Shoulder and Elbow Surgeons. Three stages of recovery are proposed, which initially protect and then gradually load soft tissue affected by the surgical procedure, such as the subscapularis, for optimal patient outcomes. The proposed guidelines should be used in collaboration with surgeon preferences and patient-specific factors.

Artroplastia de ombro: tenotomia do subescapular versus osteotomia do tubérculo menor

Objective  To evaluate and compare subscapular muscle function among patients undergoing subscapular tenotomy (Group A) and lesser tuberosity osteotomy (Group B), in patients treated with total and partial anatomic shoulder arthroplasty for primary osteoarthrosis.

Methods  Retrospective study of patients with primary glenohumeral osteoarthrosis surgically undergoing total or partial anatomic shoulder prosthesis implant, evaluated by clinical examination, imaging exams, analogue pain scale and Constant and Murley functional score. A total of 28 patients were evaluated, totalizing a sample of 32 operated shoulders. The minimum follow-up was of 12 months (mean 47.45 months).

Results  Among patients submitted to subscapularis tendon tenotomy, 10 had an ultrasound with total rupture of its thickness (56%). All of the patients of the group B showed lesser tuberosity healing. There was no difference between groups comparing strength evaluated by Belly press and Bear hug tests as well as clinical outcome, through the Constant and Murley score.

Conclusions  We did not find differences between Groups A and B evidenciated by comparing strength in the Lift-off test, in the Belly press and Bear hug tests and through he Constant and Murley score.

Total Shoulder Arthroplasty Utilizing the Subscapularis-Sparing Approach

Traditionally, total shoulder arthroplasty is performed through the deltopectoral approach with violation of the subscapularis tendon. In order to reduce the incidence of postoperative subscapularis dysfunction, the subscapularis-sparing approach, performed entirely through the rotator interval, was developed. This technique allows earlier rehabilitation and may potentially prevent subsequent subscapularis insufficiency and clinical failures.

Shoulder replacement surgery for osteoarthritis and rotator cuff tear arthropathy

BACKGROUND

Shoulder replacement surgery is an established treatment for patients with end-stage glenohumeral osteoarthritis or rotator cuff tear arthropathy who have not improved with non-operative treatment. Different types of shoulder replacement are commonly used, but their relative benefits and risks compared versus one another and versus other treatments are uncertain. This expanded scope review is an update of a Cochrane Review first published in 2010.

OBJECTIVES

To determine the benefits and harms of shoulder replacement surgery in adults with osteoarthritis (OA) of the shoulder, including rotator cuff tear arthropathy (RCTA).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, SportDiscus, and Web of Science up to January 2019. We also searched clinical trial registers, conference proceedings, and reference lists from previous systematic reviews and included studies.

SELECTION CRITERIA

We included randomised studies comparing any type of shoulder replacement surgery versus any other surgical or non-surgical treatment, no treatment, or placebo. We also included randomised studies comparing any type of shoulder replacement or technique versus another. Study participants were adults with osteoarthritis of the glenohumeral joint or rotator cuff tear arthropathy. We assessed the following major outcomes: pain, function, participant-rated global assessment of treatment success, quality of life, adverse events, serious adverse events, and risk of revision or re-operation or treatment failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We collected trial data on benefits and harms.

MAIN RESULTS

We included 20 studies involving 1083 participants (1105 shoulders). We found five studies comparing one type of shoulder replacement surgery to another type of shoulder replacement surgery, including three studies comparing conventional stemmed total shoulder replacement (TSR) surgery to stemmed humeral hemiarthroplasty. The remaining 15 studies compared one type of shoulder replacement to the same type of replacement performed with a technical modification or a different prosthetic component. We found no studies comparing shoulder replacement surgery to any other type of surgical treatment or to any type of non-surgical treatment. We found no studies comparing reverse total shoulder replacement surgery to any other type of treatment or to any type of replacement. Trial size varied from 16 to 161 participants. Participant mean age ranged from 63 to 81 years. 47% of participants were male. Sixteen trials reported participants with a diagnosis of osteoarthritis and intact rotator cuff tendons. Four trials reported patients with osteoarthritis and a rotator cuff tear or rotator cuff tear arthropathy. All studies were at unclear or high risk of bias for at least two domains, and only one study was free from high risk of bias (included in the main comparison). The most common sources of bias were lack of blinding of participants and assessors, attrition, and major baseline imbalance. Three studies allowed a comparison of conventional stemmed TSR surgery versus stemmed humeral hemiarthroplasty in people with osteoarthritis. At two years, low-quality evidence from two trials (downgraded for bias and imprecision) suggested there may be a small but clinically uncertain improvement in pain and function. On a scale of 0 to 10 (0 is no pain), mean pain was 2.78 points after stemmed humeral hemiarthroplasty and 1.49 points lower (0.1 lower to 2.88 lower) after conventional stemmed TSR. On a scale of 0 to 100 (100 = normal function), the mean function score was 72.8 points after stemmed humeral hemiarthroplasty and 10.57 points higher (2.11 higher to 19.02 higher) after conventional stemmed TSR. There may be no difference in quality of life based on low-quality evidence, downgraded for risk of bias and imprecision. On a scale of 0 to 100 (100 = normal), mean mental quality of life was rated as 57.4 points after stemmed humeral hemiarthroplasty and 1.0 point higher (5.1 lower to 7.1 higher) after conventional stemmed TSR. We are uncertain whether there is any difference in the rate of adverse events or the rate of revision, re-operation, or treatment failure based on very low-quality evidence (downgraded three levels for risk of bias and serious imprecision). The rate of any adverse event following stemmed humeral hemiarthroplasty was 286 per 1000, and following conventional stemmed TSR 143 per 1000, for an absolute difference of 14% fewer events (25% fewer to 21% more). Adverse events included fractures, dislocations, infections, and rotator cuff failure. The rate of revision, re-operation, or treatment failure was 103 per 1000, and following conventional stemmed TSR 77 per 1000, for an absolute difference of 2.6% fewer events (8% fewer to 15% more). Participant-rated global assessment of treatment success was not reported.

AUTHORS' CONCLUSIONS

Although it is an established procedure, no high-quality randomised trials have been conducted to determine whether shoulder replacement might be more effective than other treatments for osteoarthritis or rotator cuff tear arthropathy of the shoulder. We remain uncertain about which type or technique of shoulder replacement surgery is most effective in different situations. When humeral hemiarthroplasty was compared to TSR surgery for osteoarthritis, low-quality evidence led to uncertainty about whether there is a clinically important benefit for patient-reported pain or function and suggested there may be little or no difference in quality of life. Evidence is insufficient to show whether TSR is associated with greater or less risk of harm than humeral hemiarthroplasty. Available randomised studies did not provide sufficient data to reliably inform conclusions about adverse events and harm. Although reverse TSR is now the most commonly performed type of shoulder replacement, we found no studies comparing reverse TSR to any other type of treatment.

A randomized controlled trial comparing subscapularis tenotomy with peel in anatomic shoulder arthroplasty

BACKGROUND

Controversy exists regarding the optimal technique of subscapularis tendon mobilization during anatomic shoulder arthroplasty. The purpose of this prospective, randomized, double-blind study was to compare internal rotation strength in the belly-press position and functional outcomes between the subscapularis tenotomy and subscapularis peel approaches during shoulder arthroplasty.

METHODS

Patients undergoing anatomic shoulder arthroplasty were randomized to either a tenotomy or peel approach. The primary outcome was internal rotation strength in the belly-press position, measured by an electronic handheld dynamometer at 24 months postoperatively. Secondary outcomes included the Western Ontario Osteoarthritis of the Shoulder (WOOS) index score, American Shoulder and Elbow Surgeons (ASES) score, range of motion, radiographic lucencies, and adverse events.

RESULTS

We randomized 100 patients to subscapularis tenotomy (n = 47) or peel (n = 53). Eighty-one percent of the cohort returned for 24 months' follow-up. Compared with baseline measures, mean internal rotation strength in the belly-press position and WOOS and ASES scores improved in both groups at final follow-up (P < .0001). Intention-to-treat analysis for internal rotation strength at 24 months revealed no significant difference (P = .57) between tenotomy (mean, 4.9 kg; SD, 3.8 kg) and peel (mean, 5.4 kg; SD, 3.9 kg). Comparison of WOOS and ASES scores demonstrated no significant differences between groups at any time point. The healing rates by ultrasound were 72% for tenotomy and 71% for peel (P = .99).

DISCUSSION

No statistically significant difference in internal rotation strength was identified between the tenotomy and peel groups. The secondary outcomes were not significantly different between groups.

Subscapularis management in stemless total shoulder arthroplasty: tenotomy versus peel versus lesser tuberosity osteotomy

BACKGROUND

It is unknown whether subscapularis management technique has an influence on the outcomes and complications of stemless total shoulder arthroplasty. The purpose of this study, therefore, was to compare outcomes and complications between subscapularis tenotomy, peel, and lesser tuberosity osteotomy used during stemless shoulder arthroplasty.

METHODS

We reviewed 188 stemless anatomic total shoulder arthroplasties and compared clinical and functional outcomes between those performed through a subscapularis tenotomy (n = 68), subscapularis peel (n = 65), or lesser tuberosity osteotomy (n = 55). Patients were followed up clinically and radiographically at 6 months, 1 year, and 2 years postoperatively.

RESULTS

At 2 years postoperatively, no statistically significant differences in visual analog scale pain scores, American Shoulder and Elbow Surgeons scores, or patient-reported instability (P ≥ .19) were found between groups. Active external rotation was greater in the peel group (P = .006) than in the tenotomy group but was not different compared with the lesser tuberosity osteotomy group (P = .07). No statistically significant difference in clinical subscapularis failures was noted between groups (P = .11); however, 2 patients in the peel group sustained a subscapularis failure requiring reoperation.

DISCUSSION

The results of this multicenter comparative analysis show that all 3 subscapularis management techniques are effective and safe in the short term when used with stemless anatomic total shoulder arthroplasty.

Shoulder arthroplasty using mini-stem humeral components and a lesser tuberosity osteotomy

PURPOSE

To determine whether lesser tuberosity osteotomy (LTO) and mini-stem humeral components (MSHCs) can be safely and effectively used together in total and hemi-shoulder arthroplasty (TSA/HHA).

METHODS

This is a retrospective review of consecutive patients who underwent anatomic TSA/HHA utilizing combined LTO/MSHC with minimum 2-year follow-up. Six-week and final radiographs, range of motion, pain scores, and selected outcome measures were assessed.

RESULTS

Seventy five shoulders with mean follow-up of 27.8 months (24-50 months) were analyzed. Sixty-seven (89.3%) shoulders had uneventful LTO healing. There were five (6.67%) LTO failures, one (1.33%) fibrous union, and two (2.67%) osteotomies that had displaced > 4 mm at 6 weeks; four of the five failures required open repair, including one converted to reverse TSA. The other failure, the fibrous union, and the two displaced osteotomies were without clinical deficits and elected for non-operative management. One patient required intraoperative conversion to a long stem due to concern that metaphyseal bone integrity was compromised, in part, by the LTO. Four (5.33%) stems subsided, with one of them also being frankly loose and requiring revision, while the other three were asymptomatic, not requiring treatment. No other stems were judged to be loose. Mean ASES, SANE, VAS, forward flexion, external rotation, and internal rotation all improved significantly (p < 0.001 for all).

CONCLUSIONS

LTO/MSHC use is appropriate for TSA/HHA, achieving pain relief and functional improvement. Component loosening appears uncommon at early follow-up. Long-stem components should be available in case the metaphyseal bone is compromised. When performed properly, LTO/MSHC use is a safe and effective surgical strategy.

Lesser tuberosity osteotomy in total shoulder arthroplasty: impact of radiographic healing on outcomes

BACKGROUND

Lesser tuberosity osteotomy (LTO) has gained popularity in anatomic total shoulder arthroplasty (TSA); however, healing rates have not been universally high. This study examined differences in outcomes based on variations in LTO healing.

METHODS

A retrospective review identified primary TSA patients with 2-year minimum follow-up treated with a LTO. Postoperative radiographs classified LTO healing as "bony union," "nondisplaced nonunion," "displaced nonunion," and "not seen," creating 4 cohorts. Comparisons were made among patient-reported outcome measures (PROMs), motion, and radiographic evidence of component loosening.

RESULTS

The study cohort consisted of 189 patients who met inclusion criteria, with an average age of 69.5 years (range, 32-89 years) and follow-up of 50 months (range, 24-95 months). There were 143 patients with union, 16 with nondisplaced nonunion, 14 with displaced nonunion, and 16 not seen. There were no differences in preoperative comparisons. All cohorts demonstrated significant improvements in PROMs and ranges of motion; however, the displaced nonunion cohort had no improvement in Single Assessment Numeric Evaluation (0.114) or internal rotation (P = .279). Patients with displaced nonunion had lower postoperative functional scores (Simple Shoulder Test and American Shoulder and Elbow Surgeons scores; P < .01), and higher pain scores (visual analog scale for pain; P < .01). However, 85.7% of patients reported they would have the same procedure again. Simple Shoulder Test (2.5) and American Shoulder and Elbow Surgeons score (37.5) improvements exceeded minimal clinically important difference thresholds for TSA. A higher rate of glenoid gross loosening was present in the displaced nonunion cohort (3 patients [21.4%]; P < .01). There were no cases of loose humeral stems.

CONCLUSION

Patients with a displaced nonunion LTO site have lower functional scores and higher pain scores but still achieve substantial clinical improvement and high satisfaction rates.

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.

A Systematic Review of Proposed Rehabilitation Guidelines Following Anatomic and Reverse Shoulder Arthroplasty

BACKGROUND

Total shoulder arthroplasty (TSA) is indicated for patients with glenohumeral arthritis. In this procedure, the humeral head and glenoid surface are replaced with prosthetic components. Reverse total shoulder arthroplasty (RTSA) is indicated for patients with glenohumeral arthritis and a poorly functioning rotator cuff. In this procedure, a glenosphere articulates with a humerosocket. While those surgeries are commonly performed, a thorough review of the literature is required to determine the areas of agreement and variations in postoperative rehabilitation.

OBJECTIVES

To describe the literature on rehabilitation protocols following anatomic TSA and RTSA.

METHODS

For this systematic review, a computerized search was conducted in medical databases from inception to May 21, 2018 for relevant descriptive studies on TSA and RTSA rehabilitation protocols. The methodological index for nonrandomized studies tool and the modified Downs and Black tool for randomized controlled trials were used for assessment of the individual studies.

RESULTS

Sixteen studies met the inclusion criteria, of which 1 provided level I evidence, 1 provided level III evidence, 2 provided level IV evidence, and 12 provided level V evidence. Ten of the studies described rehabilitation guidelines for TSA and 6 described those for RTSA. Following TSA, the use of a sling was recommended for a duration that varied from 3 to 8 weeks, and 4 of the 10 published protocols included resisted exercise during the initial stage of healing (the first 6 weeks after surgery). Seven of 10 published protocols recommended limiting shoulder external rotation to 30° and that passive range of motion be fully restored by 12 weeks post surgery. Suggested use of a sling post RTSA varied from "for comfort only" to 6 weeks, motion parameters varied from no passive range of motion to precautionary range limits, and all protocols agreed on performing deltoid isometric exercises early post surgery. There was a high level of heterogeneity for the rehabilitation guidelines and associated precautions for both TSA and RTSA.

CONCLUSION

The majority of published protocols were descriptive in nature. Published rehabilitation strategies following TSA and RTSA are based on biomechanical principles, healing time frames, and exercise loading principles, with little consistency among protocols. There is a need to determine optimal rehabilitation approaches post TSA and RTSA based on clinical outcomes.

LEVEL OF EVIDENCE

Therapy, level 5. J Orthop Sports Phys Ther 2019;49(5):337-346. doi:10.2519/jospt.2019.8616.

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.

Innervation of the subscapularis: an anatomic study

Background

Successful healing of the subscapularis during anatomic total shoulder arthroplasty surgery is critical to optimize functional outcomes and avoid complications. The purpose of this study was to examine the upper and lower subscapularis nerve insertion in relation to the musculotendinous junction to estimate the risk of nerve injury. Our hypothesis was that arm position changes the risks to these nerves when exposing the anterior glenoid.

Methods

Twenty cadaveric shoulders were dissected, and the subscapular nerves were identified from the posterior cord of the brachial plexus to the muscle insertion. The nerve length from the origin to the muscle insertion and the distance to the myotendinous junction were measured in various shoulder positions including neutral, external, and internal rotation.

Results

The mean length of the upper subscapular nerve was 51.4 ± 12.8 mm; that of the lower subscapular nerve was 50.5 ± 14 mm. The mean distance from the insertion of the upper subscapular nerve to the myotendinous junction 53.0 ± 14.7 mm with external rotation, 38.5 ± 9.7 mm with neutral rotation, and 30.0 ± 9.2 mm with internal rotation. The mean distance from the lower subscapular nerve to the myotendinous junction was 44.5 ± 13.8 mm with external rotation, 31.9 ± 9.3 mm with neutral rotation, and 25.4 ± 8.8 mm with internal rotation. The internally rotated position placed these nerves closest to the glenohumeral joint.

Conclusion

The upper and lower subscapular nerves insert in the muscle belly close to the myotendinous junction, putting them at risk of iatrogenic injury. Care must be taken to avoid damage with retractor placement in the anterior glenoid neck as these nerves are at risk of compression or torsional injury.

Subscapularis in Reverse Total Shoulder Arthroplasty

The use of reverse total shoulder arthroplasty (RSA) is becoming increasingly popular, but many biomechanical aspects are poorly understood. Particularly, the role and function of the subscapularis following RSA are unclear. Several clinical and biomechanical studies have analyzed its role in range of motion and stability. There is some evidence that the subscapularis is beneficial for stability but may reduce range of motion. This review provides an overview of the current literature, which suggests that the subscapularis may have a more important role in RSA than originally thought.