Applying transfer of trapezius and/or latissimus dorsi with teres major for reconstruction of abduction and external rotation of the shoulder in obstetrical brachial plexus palsy

To evaluate the effects of transfer of the trapezius and/or latissimus dorsi with the teres major for treatment of dysfunction of the shoulder in obstetrical brachial plexus palsy (OBPP), 34 patients with paresis of the abductors and external rotators, as well as co-contraction of the adductors in abduction, who had undergone reconstructive operations, were followed-up for at least 1 year. Of these, transfer of the latissimus dorsi with attached teres major to the insertion of the infraspinatus (single procedure), was performed in 25 cases, and transfer of both latissimus dorsi with teres major and trapezius (to the humerus) in nine (combined procedure). Gilbert's grading system was used for evaluation. The results showed that in spite of improvement of external rotation in most of the cases, abduction was improved in only 13 of the 25 cases with a single procedure, and that eight of nine cases with a combined procedure gained improvement of both external rotation and abduction. These results indicated that, for improvement of both abduction and external rotation of the shoulder in OBPP, transfer of the latissimus dorsi with the teres major can be performed only when abduction is > or =90 degrees; otherwise, transfer of the trapezius should be added.     

Results of latissimus dorsi and teres major transfer to the rotator cuff in the treatment of Erb's palsy

A retrospective study of the results of latissimus dorsi and teres major transfer in the treatment of Erb's palsy was conducted in 10 patients. All patients underwent release of the pectoralis major and transfer of the latissimus dorsi and teres major tendons to the rotator cuff at a mean age of 7 years and 2 months. Range of motion, patient satisfaction, and presence of any complications were evaluated postoperatively at a mean of 3 years. Active shoulder abduction improved from a mean of 72 degrees preoperatively to 136 degrees postoperatively. Postoperative shoulder active external rotation averaged 64 degrees. Subjectively, all patients participating in a questionnaire thought use of the operated-on extremity had improved since surgery. All but one patient were satisfied with the final outcome. Complications included one hypertrophic scar. Transfer of the latissimus dorsi and teres major to the rotator cuff in treatment of persistent Erb's palsy improves shoulder abduction and external rotation and results in a high degree of patient satisfaction.     

Muscle activity and coordination in the normal shoulder. An electromyographic study

Muscle activity and coordination in ten shoulders were studied in five healthy subjects using electromyography (EMG) recorded during standardized loaded movements, i.e., flexion, extension, abduction, external rotation, and internal rotation at 0 degrees, 45 degrees, and 90 degrees of abduction. Bipolar surface and intramuscular fine-wire electrodes were used, and the EMG signal was low-pass filtered, full-wave rectified, and time-averaged. Activity from the subscapularis, supraspinatus, infraspinatus, pectoralis major (sternoclavicular part), the anterior, middle, and posterior parts of the deltoid, and the latissimus dorsi was recorded in parallel. In order to allow a comparison of the activity in a subject's different muscles and the activity in specific muscles between different individuals, the EMG was normalized. Muscle activity occurred simultaneously in muscles producing the movement and in antagonistic muscles. Coordination due to muscle contractions plays a significant role in stabilizing the shoulder joint. The infraspinatus, subscapularis, and latissimus dorsi acted as stabilizers during flexion; the subscapularis acted as a stabilizer during external rotation and with the supraspinatus during extension.     

Influence of humeral prosthesis height on biomechanics of glenohumeral abduction. An in vitro study

BACKGROUND: During shoulder replacement surgery, the normal height of the proximal part of the humerus relative to the tuberosities frequently is not restored because of differences in prosthetic geometry or problems with surgical technique. The purpose of the present study was to determine the effect of humeral prosthesis height on range of motion and on the moment arms of the rotator cuff muscles during glenohumeral abduction. METHODS: Tendon excursions and abduction angles were recorded simultaneously in six cadaveric specimens during passive glenohumeral abduction in the scapular plane. Moment arms were calculated for each muscle by computing the slope of the tendon excursion-versus-glenohumeral abduction angle relationship. The experiments were carried out with the intact joint and after replacement of the humeral head with a prosthesis that was inserted in an anatomically correct position as well as 5 and 10 mm too high. RESULTS: Insertion of the prosthesis in positions that were 5 and 10 mm too high resulted in significant and marked reductions of the maximum abduction angle of 10 degrees (range, 5 degrees to 18 degrees ) and 16 degrees (range, 12 degrees to 20 degrees ), respectively. In addition, the moment arms of the infraspinatus and subscapularis decreased by 4 to 10 mm. This corresponded to a 20% to 50% decrease of the abduction moment arms of the infraspinatus and an approximately 50% to 100% decrease of the abduction moment arms of the subscapularis, depending on the abduction angle and the part of the muscle being considered. CONCLUSIONS: If a humeral head prosthesis is placed too high relative to the tuberosities, shoulder function is impaired by two potential mechanisms: (1) the inferior capsule becomes tight at lower abduction angles and limits abduction, and (2) the center of rotation is displaced upward in relation to the line of action of the rotator cuff muscles, resulting in smaller moment arms and decreased abduction moments of the respective muscles. Clinical Relevance: In patients managed with shoulder replacement surgery, limitation of range of motion, loss of abduction strength, and overload with long-term failure of the supraspinatus tendon are potential consequences of positioning the humeral head of the prosthesis proximal to the anatomic position.     

Thoracohumeral muscle activity alters glenohumeral joint biomechanics during active abduction.

Normal function of the glenohumeral joint depends on coordinated muscle forces that stabilize the joint while moving the shoulder. These forces can either provide compressive forces to press the humeral head into the glenoid or translational forces that may destabilize the glenohumeral joint. The objective of this study was to quantify the effect of pectoralis major and latissimus dorsi muscle activity on glenohumeral kinematics and joint reaction forces during simulated active abduction. Nine fresh-frozen whole upper extremities were tested using a dynamic shoulder testing apparatus. Seven muscle force combinations were examined: a standard combination and 10%, 20%, or 30% of the deltoid force applied to the latissimus dorsi or pectoralis major tendon, respectively. Pectoralis major and latissimus dorsi muscle activity decreased the maximum angle of glenohumeral abduction and external rotation, and increased the maximum horizontal adduction angle compared to the standard muscle combination. Thoracohumeral muscle activity also created a more anteriorly directed joint reaction force that resulted in anterior translation compared to the standard muscle combination. Therefore, the ratio between anteriorly directed translational forces and compressive forces increased during abduction due to this muscle activity, suggesting that thoracohumeral muscle activity may decrease glenohumeral stability based on the joint position and applied loads. A better understanding of the contribution of muscle forces to stability may improve rehabilitation protocols for the shoulder aimed at maximizing compression and minimizing translation at the glenohumeral joint.     

Latissimus dorsi transfer for the treatment of massive tears of the rotator cuff. A preliminary report

Symptomatic irrepairable rotator cuff tears usually entail complete loss of the substance of the supraspinatus and infraspinatus tendons. Loss of external rotation control and cranial migration of the humeral head on attempted flexion or abduction of the shoulder are the functional hallmarks. Transfer of the latissimus dorsi tendon from the humeral shaft to the superolateral humeral head provides a large, vascularized tendon that can be used to close a massive cuff defect and that exerts an external rotation and head-depressing moment that allow more effective action of the deltoid muscle. This procedure was carried out in 14 patients without any significant complications. Pain relief and functional results in those four cases with a minimum follow-up period of one year (average, 14 months) compared favorably with alternative treatment methods and warrant further anatomic, electromyographic, and clinical investigation.     

Optimal normalization tests for shoulder muscle activation: An electromyographic study

To accurately compare electromyographic data from different muscles and different subjects, it is necessary to normalize the integrated data obtained from each muscle. The purpose of this study was to identify the manual muscle testing positions that elicit maximal neural activation (integrated electromyography) of three rotator cuff muscles (supraspinatus, infraspinatus, and subscapularis) and five shoulder synergists (pectoralis major, latissimus dorsi, and anterior, middle, and posterior deltoids). The electromyographic activity of these eight muscles was examined in the nondominant shoulders of nine subjects. Indwelling wire electrodes (supraspinatus, infraspinatus, and subscapularis) and surface adhesive electrodes (pectoralis major, latissimus dorsi, and anterior, middle, and posterior deltoids) were placed. Each subject performed a series of 27 isometric contractions, and optimal tests (maximal neural activation) were identified for each muscle. Four tests were identified that resulted in the maximal neural activation of all eight shoulder muscles: 90° of scapular elevation with ?45° of humeral rotation for the supraspinatus, anterior deltoid, and middle deltoid; external rotation at 90° of scapular elevation and ?45° of humeral rotation for the infraspinatus and posterior deltoid: internal rotation at 90° of scapular elevation and neutral humeral rotation for the subscapularis and latissimus dorsi: and internal rotation at 0° of elevation and neutral rotation for the pectoralis major. These results identify four standard testing positions that will provide reference values for normalization of maximal voluntary contraction for the eight muscles of the shoulder examined in this study. Standardization of these test positions offers normalization guidelines that can be used in future dynamic electromyography studies of the shoulder.     

Combined pectoralis major and latissimus dorsi tendon transfer for massive rotator cuff deficiency

This report is a retrospective review of 11 consecutive patients treated with a combined transfer of the latissimus dorsi and pectoralis major tendons for massive rotator cuff deficiency. Each patient's chief complaint was diminished shoulder function and motion with little or no accompanying pain. The primary operative objective was to increase active shoulder motion. All 11 patients were followed up for at least 2 years (range, 24 to 42 months). The mean active elevation improved from 42 degrees preoperatively to 86 degrees postoperatively. The mean active external rotation improved from 0 degrees to 13 degrees. On the basis of the Medical Research Council scale, the mean abduction strength improved from 2.3 to 3.1 and the mean external rotation strength improved from 2.1 to 2.7. Overall, 4 patients made no improvement, 2 improved slightly, and 5 improved significantly. We conclude that a combined transfer of the latissimus dorsi and pectoralis major is a reasonable and safe procedure that may restore active elevation and external rotation in some patients' shoulders with a massive rotator cuff deficiency that have not responded favorably to traditional nonoperative and operative techniques. However, it is difficult to conclude, based on our experience, for which patients this surgery can be predictably successful.     

Latissimus-dorsi-Transfer bei nichtrekonstruierbarem Rotatorenmanschettendefekt

Objective

Improvement of glenohumeral dynamic centering and active external rotation by a transfer of the latissimus dorsi tendon to the greater tuberosity or the lateral proximal humerus.

Indications

Irreparable posterosuperior rotator cuff tears.

Contraindications

Cuff tear arthropathy, subscapularis tendon tear, deltoid insufficiency, palsy of the axillary nerve.

Surgical technique

Diagnostic arthroscopy in lateral decubitus position. Placement of suture through the biceps tendon and supragleonidal tenotomy. Posterior approach. Preparation and mobilization of a pedicled latissimus dorsi flap. Second anterior incision with delta split. Debridement of the torn rotator cuff. Insertion of suture anchors in the greater tuberosity. Passing of the muscle flap inferior to the posterior deltoid and fixation with suture anchors to the greater tuberosity (where applicable suturing with remaining rotator cuff tissue).

Postoperative management

Immobilization in a thorax abduction cast for 6?weeks. Passive exercises out of the cast (IR/ER 0-0-free and ABD/ADD free-45-0°). Active assistive exercises from week?4 postoperatively. Stepwise increase of passive range of motion from week?7. Unlimited active range of motion from week?10.

Results

After an average follow-up of 57.6 (SD?27.5) months 17?patients were examined clinically. The average age at time of surgery was 55.6 (SD?7.7) years. At follow-up the patients showed an average Constant score of 64.4?points (SD?17.4). The active external rotation in 0° abduction was 16° (SD?17). The 4?patients (23%) with a sonographically-detected retear of the latissimus flap presented worse clinical results.     

An adjustable shoulder abduction orthosis for the post-operative management of tendon transfers: A preliminary study

Transfer of Musculus Latissimus dorsi/M. Teres major to the rotator cuff with or without M. Subscapularis/M. Pectoralis release is a widely used procedure for restoring shoulder abduction and external rotation in squeal of obstetric brachial plexus palsy. After the operation a shoulder abduction orthosis in maximal external rotation and 90 - 100 degrees abduction is utilized following six weeks of immobilization in a shoulder spica cast for protecting the newly transferred muscle from undue elongation. However this in turn may cause contracture of the external rotators. To overcome this problem, a modified shoulder abduction splint with adjustable internal-external rotation/abduction-adduction ranges was developed in the orthotics department of a rehabilitation center. The custom molded adjustable shoulder abduction orthosis is described and the preliminary results are compared with former applications.     

Biomechanical analysis of the subscapularis,infraspinatus and teres minor length and moment arm after reverse shoulder arthroplasty: a cadaveric study

BackgroundReverse shoulder arthroplasty (RSA) affects the length and moment arm of the deltoid and rotator cuff. Currently, RSA is commonly considered for cuff-intact conditions, such as primary glenohumeral osteoarthritis. As such, understanding the effect of contemporary lateralized designs on the rotator cuff is paramount. The purpose of this study was to determine changes in length and moment arm of the subscapularis, infraspinatus and teres minor with implantation of one of 3 RSA designs.MethodsA previously validated model was used in 6 hemi-toraces with the shoulder attached. Suture lines were run through pneumatic cylinders from the insertion to the origin of 10 muscles to apply a constant, stabilizing load. Electromagnetic tracking sensors were fixed to the thorax, scapula, and humerus to record 3-dimensional kinematics. Coordinate systems were established according to ISB recommendations. The origin and insertion of the subscapularis, infraspinatus and teres minor were digitized and tracked. Testing consisted of manually rotating the humerus through 5 cycles of its internal-external rotation arc. Kinematic data was collected at 120 Hz. Testing was performed in 3 positions of abduction: 0°, 30°, and 60°. After testing the intact shoulder, RSA was performed using 3 different configurations: an onlay 135-degree humeral component matched with a 2-mm lateralized glenosphere, the same humeral component with a 6-mm lateralized glenosphere, and an inlay 135-degree humeral component matched with a 10 mm lateralized glenosphere. Minimal muscle operative lengths, maximal muscle operative lengths, and muscle moment arms were computed.ResultsWhen compared with the native shoulder, all 3 configurations of RSA resulted in statistically significant increases in both the minimal and maximal operative lengths of the subscapularis in all abduction positions. The teres minor only showed a statistically significant increase in minimal and maximal length at 60° of abduction. The infraspinatus showed a statistically significant increase in tendon excursion at 0° and 30° of abduction. In 40° of abduction and 40° of internal rotation, all RSA configurations translated in a decreased subscapularis internal rotation moment arm. On the contrary, RSA increased the external rotation moment arm of the infraspinatus in neutral rotation and 0° of abduction.ConclusionImplantation of contemporary lateralized RSA implants led to increased length of the subscapularis to a greater extent than the increased length experienced by the infraspinatus and teres minor. The moment arm of the subscapularis decreased, whereas the moment arm of the teres minor in neutral rotation with the arm in abduction increased.Level of EvidenceLevel III; Basic Science, Biomechanics Study     

Variation of the latissimus dorsi

A typical muscle variation of latissimus dorsi — the axillary arch is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi passing over the axilla under the axillary fascia crossing the medial side of the brachial plexus to continue as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. The full extent of the muscle is rarely present. Slips of muscle extend from the latissimus dorsi at the inferior angle of scapula to insert into pectoralis major (Langer), coracobrachilis, biceps or coracoid process forming what is described as a common variant - the muscular axillary arch. We report three cases of variants of latissimus dorsi, one of which has not been reported in the literature before.KEY WORDS: Axillary arch, latissimus dorsi, shoulder muscle transfer, variant     

The influence of testing positions and resistance locations on muscle activities during shoulder internal rotation strength measurements in young healthy adults

BackgroundAlthough some tests of shoulder internal rotator strength including subscapularis are commonly used in clinical practice, the differences in shoulder muscle activities other than subscapularis muscle among those tests are not well understood. The purpose of this study was to examine the activities of the superficial shoulder muscles in addition to internal rotation strength during two belly-press and three lift-off test positions.MethodsThirteen healthy young adult men (age 29.5 ± 5.4 years) were recruited for the present study. They performed isometric shoulder internal rotation against manual resistance during the belly-press test positions with two different resistance locations and the lift-off test with three different arm positions. The surface electromyographic activities of the superficial shoulder muscles, including the deltoid (anterior, middle, posterior), pectoralis major, long head of triceps and latissimus dorsi muscle, were collected and compared between the two belly-press tests, and among the three lift-off test positions (P < 0.05).ResultsThe belly-press test position with resistance to elbow showed significantly greater activities of the anterior and middle deltoid muscle than the original belly-press test; but showed significantly smaller activities of pectoralis major, triceps and latissimus dorsi muscle than the original belly-press test. Among the three lift-off tests, all muscle activities, except for the pectoralis major, were greater in the lift-off at L4/5 than in the lift-off at buttock and thigh. Lift-off at thigh showed significantly smaller activity of pectoralis major than the lift-off at L4/5 and buttock.ConclusionsThe findings of the present study suggest that clinician should give attention to compensatory motions by excessive shoulder extensor and adductor muscle activities for the original belly press test, by excessive deltoid muscle activities for the modified belly-press, and by excessive shoulder extensor muscle activities for the lift off test in the inferior arm positions.     

Latissimus dorsi transfer for primary treatment of irreparable rotator cuff tears

Transfer of the musculotendinous unit of the latissimus dorsi was performed in seven patients (5 men and 2 women, with a mean age of 57 years) with irreparable rotator cuff tear who had had no previous surgery for cuff repair. Preoperatively, the mean active shoulder motion was 86° in flexion, 74° in abduction and 22° in external rotation. One patient had a positive lift-off test. The average preoperative Constant and Murley score was 44%. Diagnosis of irreparability of the cuff leasion was made preoperatively only in one case. In the remaining patients, the preoperative data only led to suspect that the tear was irreparable. At surgery, all patients had an irreparable tear of the superoinferior portion of the cuff and one patient also had a tear of the subscapularis tendon. In all cases the latissimus dorsi tendon was inserted to the greater tuberosity and, in four cases, to the subscapularis tendon; in three patients it was sutured to the bicipital tendon. Postoperatively all patients had relief of shoulder pain. The mean improvement in active flexion, abduction and external rotation was, respectively, 39°, 29° and 10°: At the latest follow-up, the average Constant and Murley score was 64%. The results of surgery were rated as excellent in three cases, good in two, fair in one and poor in one. All patients but one returned to preoperative work. Transfer of the latissimus dorsi muscle is an effective procedure for patients in middle or early elderly age who have an irreparable tear of the supraspinatus and infraspinatus tendons. Received: 18 December 2001/Accepted: 4 January 2002     

Neer Award 2006: Biomechanical assessment of inferior tuberosity placement during hemiarthroplasty for four-part proximal humeral fractures

Tuberosity malpositioning commonly occurs and is associated with a decline in clinical function after prosthetic shoulder reconstruction for proximal humeral fractures. This study assesses the biomechanical effects of inferior tuberosity position on glenohumeral joint forces and humeral head position at multiple positions. Eight fresh-frozen cadaveric shoulders were tested. Hemiarthroplasty was performed with preservation of anatomic tuberosity height and with 10 mm and 20 mm of inferior tuberosity displacement. The rotator cuff, deltoid, pectoralis major, and latissimus dorsi muscles were statically loaded. Contact forces and humeral head position were recorded within a functional range of motion. Glenohumeral joint forces shifted significantly superiorly (P < .05) at 30 degrees of abduction after both 10 mm and 20 mm of tuberosity displacement. At 60 degrees of glenohumeral abduction, glenohumeral joint forces remained significantly altered after tuberosity displacement of 10 mm and 20 mm compared with the intact height (P < .005). This study demonstrates that, during hemiarthroplasty performed for proximal humeral fractures, malpositioning the tuberosities inferiorly results in significant superior glenohumeral joint force displacement. These findings suggest that the mechanical advantage of the shoulder abductor muscles is compromised with inferior tuberosity malpositioning and may help to explain inferior functional results seen in these patients.     

The biomechanical role of the subscapularis in latissimus dorsi transfer for the treatment of irreparable rotator cuff tears

Inferior functional results of latissimus tendon transfer for the treatment of irreparable rotator cuff tears have been reported in the presence of a subscapularis tendon tear. A biomechanical or experimental explanation for the necessity of an intact subscapularis is unavailable. It was, therefore, the purpose of this investigation to study the biomechanical role of the subscapularis in the treatment of a posterosuperior rotator cuff tear with latissimus dorsi transfer. A biomechanical cadaveric model was developed to reproduce glenohumeral motion patterns created by loading of the transferred latissimus dorsi tendon with and without simultaneous action of the subscapularis muscle. Significant differences could be demonstrated not only for translation but also for rotation of the humeral head depending on subscapularis action. In the neutral and in the abducted/externally rotated position of the arm, anterior translation and dislocation of the joint were encountered without subscapularis action. Our results provide evidence that motion patterns of the humeral head are significantly altered in the absence of the stabilizing effect of the subscapularis muscle. The inferior functional results of latissimus dorsi transfer in the presence of subscapularis dysfunction are explained by the loss of centering of the humeral head upon abduction and elevation if subscapularis function is deficient.     

Quantifying shoulder rotation weakness in patients with shoulder impingement

The purpose of this study was to determine whether strength deficits could be detected in individuals with and without shoulder impingement, all of whom had normal shoulder strength bilaterally according to grading of manual muscle testing. Strength of the internal rotators and external rotators was tested isokinetically at 60 degrees /s and 180 degrees /s, as well as manually with a handheld dynamometer (HHD) in 17 patients and 22 control subjects. Testing was performed with the shoulder positioned in the scapular plane and in 90 degrees of shoulder abduction with 90 degrees of elbow flexion (90-90). The peak torque was determined for each movement. The strength deficit between the involved and uninvolved arms (patients) and the dominant and nondominant arms (control subjects) was calculated for each subject. Comparisons were made for the scapular-plane and 90-90 positions between isokinetic and HHD testing. Despite a normal muscle grade, patients had marked weakness (28% deficit, P < .01) in external rotators at the 90-90 position tested with the HHD. In contrast, external rotator weakness was not evident with isokinetic testing at the 90-90 position (60 degrees /s and 180 degrees /s, 0% deficit, P = .99). In control subjects, greater internal rotator strength in the dominant compared with the nondominant arm was evident with the HHD at the 90-90 position (11%, P < .01) and in the scapular plane (7%, P < .05). Using an HHD while performing manual muscle testing can quantify shoulder strength deficits that may not be apparent with isokinetic testing. By using an HHD during shoulder testing, clinicians can identify weakness that may have been presumed normal.     

Brachial plexus palsy secondary to birth injuries

We describe the long-term results in ten patients with obstetric brachial plexus palsy of anterior shoulder release combined with transfer of teres major and latissimus dorsi posteriorly and laterally to allow them to act as external rotators. Eight patients had a lesion of the superior trunk and two some involvement of the entire brachial plexus. The mean age at operation was six years, and the mean follow-up was 30 years. Before operation, the patients were unable actively to rotate the arm externally beyond neutral, although this movement was passively normal. All showed decreased strength of the external rotator, but had normal strength of the internal rotator muscles. Radiologically, no severe bony changes were seen in the glenohumeral joint. No clinically detectable improvement of active abduction was noted in any patient. The mean active external rotation after operation was 36.5 degrees. This was maintained for a mean of ten years, and then deteriorated in eight patients. At the latest follow-up the mean active external rotation was 10.5 degrees. The early satisfactory results of the procedure were not maintained. In the long term there was loss of active external rotation, possibly because of gradual degeneration of the transferred muscles, contracture of the surrounding soft tissues and degenerative changes in the glenohumeral joint.     

Flexorplasty of the elbow

Sixteen patients (mean age, 31.6 years) whose elbow flexor power was absent or inadequate were treated with the following muscle transfer procedures: (1) bipolar pectoralis major transfer in five, (2) unipolar or bipolar latissimus dorsi transfer in five, (3) free latissimus dorsi transfer in three, and (4) triceps-to-biceps transfer in three. None of the patients in this series was a candidate for proximal advancement of the forearm muscles. At the follow-up evaluation (mean, 31.5 months), the mean antigravity elbow flexion arcs obtained from each procedure were as follows: pectoralis transfer, 91 degrees; latissimus dorsi transfer, 87 degrees; free latissimus dorsi transfer, 11 degrees; and triceps-to-biceps transfer, 125 degrees. The results were equally favorable for the pectoralis and latissimus dorsi transfer. Triceps transfer was reliable for restoration of an excellent range of elbow flexion, but active elbow extension was lost. Poor results were obtained with the free latissimus dorsi transfers.