Short-Term Outcomes of Lower Trapezius Tendon Transfer With Achilles Allograft for Irreparable Posterosuperior Rotator Cuff Tears

Tendon Transfers in Reverse Total Shoulder Arthroplasty: A Systematic Review

PURPOSE

The purpose of this study was to evaluate clinical outcomes after tendon transfers in the setting of reverse total shoulder arthroplasty (RTSA).

METHODS

PubMed and Embase were searched according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines to find primary clinical studies of any type of tendon transfer in the setting of RTSA.

RESULTS

Overall, 17 studies (level of evidence [LOE] I: 1, LOE II: 0, LOE III: 3, LOE IV: 13) met inclusion criteria, with 300 shoulders. Most patients were female (56.7%), with an average age of 68.7 years (range 19 to 89) and a mean follow-up of 46.2 months (range 6 to 174). 11 studies reported outcomes after combined latissimus dorsi and teres major transfer (LDTM) while eight studies reported on latissimus dorsi transfer only (LD). Improvements in commonly reported subjective and functional outcome measures were as follows: external rotation +32° (LDTM) and +30° (LD), flexion +65° (LDTM) and +59° (LD), Visual Analog Score -5.4 (LDTM) and -4.5 (LD), subjective shoulder value +43.8% (LDTM) and +46.3% (LD), and overall Constant score +33.8 (LDTM) and +38.7 (LD). The overall complication rate was 11.3%, including tendon transfer ruptures (0.7%), instability (3.0%), infection (2.0%), and nerve injury (0.3%). The all-cause repeat operation rate was 7.3%, most commonly for arthroplasty revision (5.3%). Subgroup analysis revealed that lateralized implants with tendon transfer resulted in markedly greater improvements in Constant score, flexion, ER1, and ER2 while medialized implants with tendon transfer had markedly greater improvements in Visual Analog Score, subjective shoulder value, and abduction.

CONCLUSION

Patients undergoing tendon transfer of either combined LDTM or latissimus dorsi alone in the setting of RTSA have markedly improved subjective and functional outcomes. A moderate incidence of complications (11.3%) was noted in this patient population.

A scoping review of tendon transfer surgeries and postsurgical physical therapy interventions in individuals with massive rotator cuff tears

OBJECTIVE

To identify tendon transfer surgeries and postsurgical physical therapy interventions in people with massive rotator cuff (RC) tears.

METHODS

The literature search was conducted in the MEDLINE, Science Direct, Scopus, Web of Science, and PEDro databases from inception to September 2022. Studies with patients diagnosed with massive RC tears undergoing tendon transfers that reported physical therapy interventions after surgery were included. Two reviewers pooled the data into ad hoc summary tables with the following information: authors, year, study characteristics (sample size, tendon transfer surgical used, approach type, preoperative risk, deficit addressed, additional surgical interventions), and physical therapy interventions (early stage, intermediate stage, and advanced stage).

RESULTS

Forty-four articles (59.0% case series) were included, with a total sample of 1213 participants. The most frequently used surgery was the isolated tendon transfer of the latissimus dorsi (49.1%). Most of the studies reported three main stages of physical therapy interventions after tendon transfer surgery: early stage (lasting 5-6 weeks), intermediate stage (started at 7-12 weeks), and advanced stage (started at 12 weeks). Physical therapy interventions included passive, active-assisted, resisted therapeutic exercise, and hydrotherapy.

CONCLUSIONS

The evidence regarding physical therapy interventions after RC tendon transfer surgery is limited to the number and duration of the stages and general characteristics without specifying the type and dose of the interventions. Future research with high methodological quality should integrate more detailed rehabilitation protocols to better guide therapeutic decisions after RC transfer surgery.

Mid-term outcomes of arthroscopically assisted lower trapezius tendon transfer using Achilles allograft in treatment of posterior-superior irreparable rotator cuff tear

BACKGROUND

Arthroscopically assisted lower trapezius tendon (aLTT) transfer is one of the treatment options for posterior-superior irreparable rotator cuff tears (PSIRCTs). Although short-term clinical outcomes have shown promising results, there are currently no reported clinical outcomes over a longer follow-up period. This study evaluated the mid-term outcomes of aLTT transfer in patients with a diagnosis of PSIRCT.

METHODS

This retrospective case-series study included patients who underwent aLTT transfer between May 2017 and May 2019. The clinical outcome assessment included the visual analog scale (VAS) pain score, Constant score, American Shoulder and Elbow Surgeons score, University of California-Los Angeles score, Activities of Daily Living Requiring Active External Rotation (ADLER) score, active range of motion, Single Assessment Numeric Evaluation score, and return-to-work rate. The radiographic analysis included the acromiohumeral distance, Hamada grade, and integrity of the transferred tendon at final follow-up. Subgroup analyses were performed based on the integrity of the transferred tendon and the trophicity of the teres minor (Tm).

RESULTS

This study enrolled 36 patients with a mean age of 63.4 years who met the inclusion criteria and were followed up for a mean of 58.2 ± 5.3 months. At final follow-up, the patients showed significant improvement in mean VAS score, Constant score, American Shoulder and Elbow Surgeons score, University of California-Los Angeles score, ADLER score, and active range of motion in all directions except internal rotation. A decrease in the acromiohumeral distance and an increase in the Hamada grade were observed at final follow-up (P = .040 and P = .006, respectively). Retears of the transferred tendon occurred in 7 patients, and postoperative infections developed in 2 individuals. An interesting finding was that the retear group still demonstrated improvement in the VAS score but did not show improvement in external rotation at the side by the final follow-up. Compared with the Tm non-hypertrophy group, the Tm hypertrophy group showed significantly better improvement in external rotation at 90° of abduction and at the side, as well as the ADLER score. Of the study patients, 30 (83.3%) were able to successfully resume their previous work.

CONCLUSION

In this study, aLTT transfer in patients with PSIRCTs demonstrated significant improvements in clinical and radiologic outcomes by the final follow-up. These findings provide support for the mid-term safety and effectiveness of aLTT transfer as a viable joint-preserving treatment option for PSIRCTs. However, larger and longer-term studies are still needed to further validate these findings.

Middle trapezius tendon transfer using Achilles allograft for irreparable isolated supraspinatus tendon tears effectively restores the superior stability of the humeral head without restricting range of motion: a biomechanical study

BACKGROUND

Middle trapezius tendon (MTT) transfer has been suggested for promising treatment of irreparable isolated supraspinatus tendon tears (IISTTs). However, there have been no attempts to assess the biomechanical efficacy of MTT transfer. This study aims to evaluate the biomechanical efficacy of MTT transfer in the setting of IISTTs.

METHODS

Eight fresh frozen cadaveric shoulders were tested in 3 conditions: (1) intact rotator cuff, (2) IISTT, and (3) MTT transfer using Achilles allograft for IISTTs. Total humeral rotational range of motion (ROM), superior translation of the humeral head, and subacromial contact characteristics were measured at 0°, 20°, and 40° glenohumeral abduction (representing 0°, 30°, and 60° shoulder abduction). Superior translation and subacromial contact pressures were measured at 0°, 30°, 60°, and 90° external rotation (ER). Two different MTT muscle loading conditions were investigated. A linear mixed effects model and Tukey post hoc test were used for statistical analysis.

RESULTS

Total ROM was significantly increased after IISTT at 20° abduction (P = .037). There were no changes in total ROM following MTT transfer compared to the IISTT condition (P > .625 for all comparisons). The IISTT condition significantly increased superior translation compared to the intact rotator cuff condition in 0° and 20° abduction with all ER angles (P < .001), 40° abduction-30° ER (P = .016), and 40° abduction-60° ER (P = .002). MTT transfer significantly decreased superior translation of the humeral head at all abduction angles compared to the IISTT condition (P < .026). MTT transfer significantly decreased peak contact pressure by 638.7 kPa (normal loading) and 726.8 kPa (double loading) at 0° abduction-30° ER compared to the IISTT condition (P < .001). Mean contact pressure was decreased by 102.8 kPa (normal loading) and 118.0 kPa (double loading) at 0° abduction-30° ER (P < .001) and 101.0 kPa (normal loading) and 99.2 kPa (double loading) at 0° abduction-60° ER (P < .001). MTT transfer at 20° abduction-30° ER with 24 N loading significantly decreased contact pressure by 91.2 kPa (P = .035).

CONCLUSIONS

The MTT transfer biomechanically restored the superior humeral head translation and reduced the subacromial contact pressure in a cadaveric model of IISTT, while not restricting total ROM. These findings suggest that MTT transfer may have potential as a surgical treatment for IISTTs.

Lower Trapezius Transfer Improves Clinical Outcomes With a Rate of Complications and Reoperations Comparable to Other Surgical Alternatives in Patients with Functionally Irreparable Rotator Cuff Tears: A Systematic Review

PURPOSE

To analyze the clinical outcomes of lower trapezius transfer (LTT) for patients with functionally irreparable rotator cuff tears (FIRCT) and summarize the available literature regarding complications and reoperations.

METHODS

After registration in the International prospective register of systematic reviews (PROSPERO [CRD42022359277]), a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. Inclusion criteria were English, full-length, peer-reviewed publications with a level of evidence IV or higher reporting on clinical outcomes of LTT for FIRCT. Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus via Elsevier databases were searched. Clinical data, complications and revisions were systematically recorded.

RESULTS

Seven studies with 159 patients were identified. The mean age range was 52 to 63 years, 70.4% of the patients included were male, and the mean follow-up time ranged between 14 and 47 months. At final follow-up, LTT lead to improvements in range of motion, with reported forward elevation (FE) and external rotation (ER) mean gains of 10° to 66° and 11° to 63°, respectively. ER lag was present before surgery in 78 patients and was reversed after LTT in all shoulders. Patient-reported outcomes were improved at final follow-up, including the American Shoulder and Elbow Society score, Shoulder Subjective Value and Visual Analogue Scale. The overall complication rate was 17.6%, and the most reported complication was posterior harvest site seroma/hematoma (6.3%). The most common reoperation was conversion to reverse shoulder arthroplasty (5%) with an overall reoperation rate of 7.5%.

CONCLUSIONS

Lower trapezius transfer improves clinical outcomes in patients with irreparable rotator cuff tears with a rate of complications and reoperations comparable to other surgical alternatives in this group of patients. Increases in forward flexion and ER are to be expected, as well as a reversal of ER lag sign when present before surgery.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Superior Capsular Reconstruction Versus Middle Trapezius Tendon Transfer for Isolated Irreparable Supraspinatus Tendon Tears: Static Versus Dynamic Reconstruction

BACKGROUND

Both superior capsular reconstruction (SCR) and middle trapezius tendon (MTT) transfer can be performed in nonarthritic young and active patients with isolated irreparable supraspinatus tendon tears (IISTTs). However, to our knowledge, no comparative clinical studies have been conducted on these procedures.

PURPOSE

To evaluate and compare the clinical and radiological outcomes of SCR and arthroscopic-assisted MTT transfer in patients with IISTTs.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 60 patients with IISTTs were categorized into 2 groups according to the surgical procedure-Group S underwent SCR (n = 34); Group M underwent MTT transfer (n = 26). The clinical outcomes included the visual analog scale score for pain, active shoulder range of motion, American Shoulder and Elbow Surgeons score, and University of California, Los Angeles, shoulder score. Radiological outcomes included the assessment of the acromiohumeral distance, progression of cuff tear arthropathy (Hamada grade), subacromial bone erosion, and graft failure.

RESULTS

The mean follow-up time was 39.3 ± 5.2 months (range, 26-59 months) and 37.6 ± 9.8 months (range, 27-54 months) in Group S and Group M, respectively. Significant improvements in clinical outcomes were observed in both groups, while the active forward flexion (148.2°± 24.1° vs 165.9°± 8.7°; P = .003) and abduction (131°± 37.3° vs 152.5°± 17.9°; P = .035) were significantly higher in Group M at the final follow-up. No significant differences were found in the postoperative Constant, American Shoulder and Elbow Surgeons, and University of California, Los Angeles, shoulder scores between the 2 groups. Radiologically, although no difference was found in the Hamada grade at the final follow-up between the 2 groups (P = .143), the rates of acromial wear (58.8% vs 15.4%; P < .001) and graft retear (47.1% vs 7.7%; P < .001) were significantly higher in Group S than in Group M.

CONCLUSION

Both SCR and MTT transfer improved the overall clinical outcomes of IISTTs postoperatively, whereas MTT transfer was superior to SCR in terms of active forward flexion and abduction range of motion. Although higher rates of graft failure and subacromial bone erosion were observed in Group S, no difference was found in the clinical scores between the 2 groups at the short-term follow-up. However, further well-structured, prolonged comparative trials should be conducted in the future.

Outcomes after arthroscopically assisted lower trapezius transfer with Achilles tendon allograft

BACKGROUND

Lower trapezius tendon transfer is 1 option to improve pain and function with massive irreparable rotator cuff tears. Magnetic resonance imaging (MRI) evaluation of tendon healing with the procedure has not yet been reported. The purpose of this study was to evaluate early tendon transfer healing using postoperative MRI scans and to assess early clinical outcomes in patients after arthroscopically assisted lower trapezius tendon transfer (AALTT) for massive irreparable rotator cuff tears.

METHODS

This was a single institution retrospective review of consecutive patients with massive irreparable rotator cuff tears who underwent AALTT with a single surgeon from January 2017 to July 2020 with a minimum 6-month follow-up. Patient information including age, sex, follow-up, prior surgical history, and type of work (sedentary or labor-intensive) was recorded. Preoperative and postoperative range of motion, external rotation strength, presence of a lag sign, and pain visual analog scale data were extracted from medical records. Patient-reported outcomes were extracted from patient charts. Six-month postoperative MRIs were reviewed for tendon transfer healing at both the greater tuberosity and the trapezius-allograft interface.

RESULTS

A total of 19 patients met inclusion criteria with average age 56.7 (range, 29-72 years). Of these patients, 17 (89.5%) were male. The average follow-up was 14.6 (range, 6-45) months. Fifteen (78.9%) patients had unsuccessful previous rotator cuff repair. Six-month MRI demonstrated complete healing of the transferred tendon in 17 of 19 patients (89.5%). There were significant improvements in postoperative pain visual analog scale (5.9 ± 2 vs. 1.8 ± 2), ASES score (44.6 ± 18 vs. 71.2 ± 24), and Patient Reported Outcomes Measurement Information System Physical (46.3 ± 6 vs. 51.3 ± 11) and in external rotation motion (10.5 ± 17° vs. 40.5 ± 13°) and strength (2.8/5 ± 1 vs. 4.7/5 ± 0.5) at final follow-up. All patients with a preoperative external rotation lag sign had reversal of their lag sign at final follow-up (15/15). Of 17 work-eligible patients, 13 (76.4%) were able to return to work.

CONCLUSION

In this series, AALTT showed a high rate of healing of the transferred tendon on MRI by 6 months postoperatively. The current findings of a high rate of early tendon transfer healing are consistent with the good early and mid-term outcomes that have been observed in AALTT and provide support for surgeon and patient expectations, postoperative rehabilitation, and return to work following AALTT for massive posterior superior rotator cuff tears.

My Approach to Failed Rotator Cuff Repair

Failed rotator cuff repairs pose several challenges due to the high incidence rate, complexity, and range of symptoms. We propose an overview for assessing and treating failed rotator cuff repairs. For active young patients, attempt revision repair with patch augmentation if possible. When anatomic revision is not viable, but muscle is retained, consider partial repair with interposition bridging. Isolated, irreparable supraspinatus tears may benefit from superior capsule reconstruction. Tendon transfer is suitable for patients with significant atrophy and multiple irreparable cuff tears. Low-demand elderly patients or those with substantial glenohumeral arthritis may consider reverse total shoulder arthroplasty if conservative management fails. There are a variety of reported outcomes in the literature but long-term studies with larger cohorts are needed to improve the management of failed rotator cuff repair.

Physiological Tensioning During Lower Trapezius Transfer for Irreparable Posterosuperior Rotator Cuff Tears May Be Important for Improvement in Shoulder Kinematics

BACKGROUND

Lower trapezius transfer (LTT) has been proposed for restoring the anteroposterior muscular force couple in the setting of an irreparable posterosuperior rotator cuff tear (PSRCT). Adequate graft tensioning during surgery may be a factor critical for sufficient restoration of shoulder kinematics and functional improvement.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the effect of tensioning during LTT on glenohumeral kinematics using a dynamic shoulder model. It was hypothesized that LTT, while maintaining physiological tension on the lower trapezius muscle, would improve glenohumeral kinematics more effectively than undertensioned or overtensioned LTT.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 10 fresh-frozen cadaveric shoulders were tested using a validated shoulder simulator. Glenohumeral abduction angle, superior migration of the humeral head, and cumulative deltoid force were compared across 5 conditions: (1) native, (2) irreparable PSRCT, (3) LTT with a 12-N load (undertensioned), (4) LTT with a 24-N load (physiologically tensioned according to the cross-sectional area ratio of the lower trapezius muscle), and (5) LTT with a 36-N load (overtensioned). Glenohumeral abduction angle and superior migration of the humeral head were measured using 3-dimensional motion tracking. Cumulative deltoid force was recorded in real time throughout dynamic abduction motion by load cells connected to actuators.

RESULTS

Physiologically tensioned (Δ13.1°), undertensioned (Δ7.3°), and overtensioned (Δ9.9°) LTT each significantly increased the glenohumeral abduction angle compared with the irreparable PSRCT (P < .001 for all). Physiologically tensioned LTT achieved a significantly greater glenohumeral abduction angle than undertensioned LTT (Δ5.9°; P < .001) or overtensioned LTT (Δ3.2°; P = .038). Superior migration of the humeral head was significantly decreased with LTT compared with the PSRCT, regardless of tensioning. Physiologically tensioned LTT resulted in significantly less superior migration of the humeral head compared with undertensioned LTT (Δ5.3 mm; P = .004). A significant decrease in cumulative deltoid force was only observed with physiologically tensioned LTT compared with the PSRCT (Δ-19.2 N; P = .044). However, compared with the native state, LTT did not completely restore glenohumeral kinematics, regardless of tensioning.

CONCLUSION

LTT was most effective in improving glenohumeral kinematics after an irreparable PSRCT when maintaining physiological tension on the lower trapezius muscle at time zero. However, LTT did not completely restore native glenohumeral kinematics, regardless of tensioning.

CLINICAL RELEVANCE

Tensioning during LTT for an irreparable PSRCT may be important to sufficiently improve glenohumeral kinematics and may be an intraoperatively modifiable key variable to ensure postoperative functional success.

Allograft-enhanced latissimus dorsi transfer is better than the conventional technique for irreparable posterosuperior rotator cuff tears. A retrospective matched cohort

PURPOSE

Latissimus dorsi tendon (LDT) transfer (LDTT) to the greater tuberosity to treat irreparable posterosuperior rotator cuff tears (RCTs) in young active patients has been shown to have up to 36% of clinical failures, most of them happening because of either deltoid origin disruption or post-operative transfer rupture from the greater tuberosity. In an attempt to simultaneously prevent both complications, a modified technique includes the following adaptations to the original technique: reinforcement and augmentation of the LDT with a tendinous allograft, enabling the use of a single deltopectoral approach. The aim of this study is to compare mid-term outcomes of the traditional LDTT technique with this modified transfer.

METHODS

Retrospective cohort study comparing two groups who underwent either the traditional (group 1; n = 19) or the modified technique (group 2; n = 27). Group homogenization was assured by statistical comparison of 24 baseline independent variables. The outcome variables were the gains to active shoulder range of motions (ROM) and UCLA scores (and all its subscores, independently), at a minimum follow-up of two years. A p value < .05 was considered to be statistically significant.

RESULTS

At a mean follow-up of 25 months, both groups have shown improvements to most variables. However, group two (modified technique) achieved greater improvements to UCLA score (p = .009), active external rotation (p = .006) and internal rotation (p = .008).

CONCLUSION

At mid-term follow-up, improvements to outcomes of the modified (single approach, allograft-enhanced) latissimus dorsi transfer were greater than those of the original technique.

The clinical results of lower trapezius tendon transfer with the peroneus longus allograft augmentation combined with interpositional repair with fascia lata in massive irreparable rotator cuff tears

OBJECTIVES

To investigate the clinical results of lower trapezius (LT) tendon transfer and interpositional repair that were performed simultaneously in patients with massive irreparable rotator cuff tears.

METHODS

Between 2018 and 2020 years, 16 patients with massive irreparable rotator cuff tears that were treated with LT tendon transfer and interpositional repair at the same time were included in this study. The mean follow-up period was 29±3 months (24-39 months) and the mean age of patients was 62±9 years (42-73 years). The acromio-humeral distance, active range of motions, Visual Analog Scale (VAS) scores, University of California-Los Angeles (UCLA) scores and Constant-Murley scores were made preoperatively and at the final follow-up.

RESULTS

At the final follow-up, forward flexion was increased from 109˚±24.7 to 144˚±22.21 (p=0.005), abduction from 60˚±16.33 to 135˚±16.33 (p=0.005) and external rotation from 12˚±16.87 to 35˚±14.34 (p=0.005). Total UCLA scores were 5.9±2.13 to 22.7±5.29 (p=0.005), Constant-Murley scores were 24±9.43 to 50.2±14.28 (p=0.008), VAS scores were 6.1±1.1 to 2.4±1.35 (p=0.007), mean acromio-humeral distances were 4.64±0.85 mm (3.42-6.23 mm) to 6.58 mm (5.25-8.21 mm) (p=0.005) preoperatively and at the final follow-up. Except one patient who had a frozen shoulder any significant complication was detected.

CONCLUSION

Adding interpositional repair to the LT tendon transfer in patients with posterior superior irreparable rotator cuff tear seems to have satisfactory short to mid-term clinical outcomes without an increase in complications.

Lower trapezius tendon transfer for irreparable rotator cuff injuries: a scoping review

Background

Rotator cuff tears are a common source of shoulder pain and dysfunction. An irreparable rotator cuff tear poses a particular treatment challenge. There have been few studies reporting the outcomes of lower trapezius tendon (LTT) transfer for irreparable rotator cuff injuries. Therefore, the purpose of this review is to summarize the postoperative functional outcomes and complications of patients undergoing a LTT transfer for massive irreparable rotator cuff injuries.

Methods

A scoping review was performed using the Medline, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar databases with the search terms "trapezius" AND "transfer." Of 362 studies included for initial screening, 37 full-text citations were reviewed, with 5 studies meeting all the inclusion criteria to be included in the review. Two reviewers extracted data on study design, patient demographics, surgical technique, functional outcomes, range of motion (ROM), and complications for each study according to the predefined criteria.

Results

Improvements in the preoperative to postoperative functional status, identified using the Disabilities of the Arm, Shoulder, and Hand (50.34 to 18), The American Shoulder and Elbow Surgeons Score (48.56 to 80.24), Visual Analog Scale (5.8 to 1.89), Single Assessment Numeric Evaluation (34.22 to 69.86), and Subjective Shoulder Value (52.24 to 77.66), were evident across all 5 studies. Preoperative to postoperative increases in ROM were seen for flexion (85 to 135), external rotation (18 to 52), and abduction (50 to 98). The overall complication rate was 18%, with seroma formation (8%) as the most common postoperative complication.

Discussion/Conclusion

Our analysis showed that LTT transfer improved postoperative function, ROM, and pain for patients with irreparable rotator cuff tears with an overall complication rate of 18%. Future controlled studies are required to directly compare LTT transfer to other tendon transfers and other surgical techniques for irreparable rotator cuff tears.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.

Muscle Tendon Transfers Around the Shoulder: Diagnosis, Treatment, Surgical Techniques, and Outcomes

➤

Muscle tendon transfers (MTTs) are effective surgical procedures for reducing pain and for improving active shoulder range of motion and patient-reported outcomes for a wide range of pathologies, including serratus anterior and trapezius muscle palsy, irreparable subscapularis tears, irreparable posterosuperior rotator cuff tears, irreparable posterior rotator cuff tears in the setting of reverse shoulder arthroplasty, and symptomatic complete deltoid deficiency.

➤

The principles of MTT include ensuring that the transferred muscle is expendable, the muscle tendon unit has similar excursion, the line of pull of the transferred tendon and of the recipient muscle are similar in terms of biomechanical force, and the transferred muscle should replace at least 1 grade of strength of the deficient recipient muscle.

➤

When MTT procedures are considered, patients must have exhausted all nonoperative management, have preserved passive range of motion, and have an understanding of the postoperative expectations and potential complications.

➤

For patients with scapulothoracic abnormal motion (STAM) due to long thoracic nerve palsy, the indirect or direct pectoralis major tendon transfer is an effective procedure for reducing pain and improving active forward elevation. For patients with STAM due to spinal accessory nerve palsy, the Eden-Lange or the triple tendon transfer procedures reduce pain and improve active forward elevation and abduction as well as patient-reported clinical outcomes.

➤

Both pectoralis major and latissimus dorsi transfer procedures for isolated irreparable subscapularis deficiency without anterosuperior humeral head escape result in improvement with respect to pain, patient-reported outcomes, and forward elevation, with the pectoralis major tendon transfer demonstrating durable long-term outcomes.

➤

The latissimus dorsi or lower trapezius tendon transfer procedures for irreparable posterosuperior rotator cuff tears reliably improve patient-reported outcomes, forward elevation, abduction, and external rotation range of motion. Additionally, latissimus dorsi transfer with or without teres major transfer can be used to restore active external rotation, both in the native shoulder and in the setting of reverse shoulder arthroplasty.

➤

The complications of MTTs include infection, hematoma, and failure of tendon transfer healing; therefore, it is recommended that these complex procedures be performed by shoulder surgeons with appropriate training.