The use of the long head of triceps interposition muscle flap for treatment of massive rotator cuff tears

Massive rotator cuff tears present a difficult problem for orthopedic surgeons. To address this problem, a long head of triceps muscle interposition flap was proposed. Ten patients underwent repair of massive rotator cuff tears using the triceps muscle flap. The patients' strength and range of motion were tested preoperatively, and a University of California, Los Angeles, shoulder score was assigned. Similar testing was performed 1 year later. Postoperatively, the patients showed significant improvement in the overall shoulder score and in the pain and function components of the score. There was no significant improvement in shoulder range of motion, except for shoulder flexion. An important finding was that there was no loss of strength in elbow extension following the loss of the long head of triceps muscle. It was concluded that the long head of triceps interposition flap is useful in the reconstruction of the massive rotator cuff tear.     

Treatment of lesions of the rotator cuff

The impingement syndrome and tendinopathy of the rotator cuff are the most common causes (complaints) of pain and disability of the shoulder. The aim of this study is to evaluate the efficacy of a specific rehabilitative protocol, integrated with the administration of a nutritional supplement, in the conservative rehabilitative treatment, as well as in post-surgery, of patients with lesions of the rotator cuff. Two groups with syndrome of the rotator cuff were formed to follow different therapeutic courses, in relation to the choice of each subject to undergo the conservative treatment (Arm A) or the surgical one (Arm B). In Arm A the study included the association of therapy with ESWT (shock waves) with the proprioceptive Multi Joint System, for rehabilitating joint movement and muscle strength of the shoulder, and a specific nutritional supplement to reduce the pain and conserve the cartilage tissue. Between February 2009 and June 2009, we enrolled 30 subjects (randomized into three homogenous groups A1, A2, A3), average age 45±10 years, with rotator cuff syndrome with calcification of the shoulder, diagnosed through clinical examination and investigative instruments (X-ray, echography or NMR). In Arm B, from September 2009 to January 2010, we enrolled 50 patients (randomized into two groups, B1 and B2), 24 male (average age 58.4: min 28 and max 78) and 26 females (average age 59.5: min 30 and max 80), who had undergone rotator cuff operations and acromionplasty for non-massive lesions without important gleno-humeral instability, with either open or arthroscopic procedures. The analysis of the results of Arm A highlights that in terms of reducing pain the main benefits were found in Group A1 where the supplement was given. From the analysis of the data of Arm B, in both groups an improvement of the first 4 items evaluated was evident. In Group B1, 84 percent of the patients declared to be satisfied and improved and 16 percent were dissatisfied; in Group B2, where the nutritional supplement was given, 92 percent were satisfied and 8 percent were dissatisfied. In conclusion, we retain that in cases of rotator cuff syndrome, an integrated rehabilitative approach, whether conservative or post-surgical, directed at taking total control of the patient, must observe particular attention to the optimization of the articular tissular metabolic balance in order to favour better functional recovery.     

Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes

Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.     

Effect of biceps-to-triceps transfer on rotator cuff stress during upper limb weight-bearing lift in tetraplegia: A modeling and simulation analysis

Rotator cuff stress during upper limb weight-bearing lifts presumably contribute to rotator cuff disease, which is the most common cause of shoulder pain in individuals with tetraplegia. Elbow extension strength appears to be a key determinant of rotator cuff stress during upper limb weight-bearing lifts since individuals with paraplegia who generate greater elbow extensor moments experience lower rotator cuff stress relative to individuals with tetraplegia. Biceps-to-triceps transfer surgery can increase elbow extension strength in individuals with tetraplegia. The purpose of this study was to determine whether active elbow extension via biceps transfer decreases rotator cuff stress during weight-bearing lifts in individuals with tetraplegia. A forward dynamics computational framework was used to estimate muscle stress during the lift; stress was computed as muscle force divided by the peak isometric muscle force. We hypothesized that rotator cuff stresses would be lower in simulated lifting with biceps transfer relative to simulated lifting without biceps transfer. We found that limited elbow extension strength in individuals with tetraplegia, regardless of whether elbow strength is enabled via biceps transfer or is residual after spinal cord injury, results in muscle stresses exceeding 85% of the peak isometric muscle stress in the supraspinatus, infraspinatus, and teres minor. The rotator cuff stresses we estimated suggest that performance of weight-bearing activities should be minimized or assisted in order to reduce the risk for shoulder pain. Our results also indicate that biceps transfer is unlikely to decrease rotator cuff stress during weight-bearing lifts in individuals with tetraplegia.     

Shoulder complex kinematics pre- and post- rotator cuff repair

This study investigated shoulder complex joint kinematics and functional outcomes before and after full-thickness supraspinatus rotator cuff repair. Nine adults (mean age 63.4 ± 6.2 years) participated in three test sessions: 0–12 weeks pre-operatively, 9–12 weeks, and 22–30 weeks post-operatively. Upper extremity kinematics of the surgical arm’s glenohumeral, acromioclavicular, sternoclavicular and thoracohumeral joints over the duration of a hair combing task were quantified with motion analysis using inverse kinematics. The UCLA Shoulder Rating and Simple Shoulder Test shoulder health outcomes were administered at each session to determine patients’ perceived function of their surgical shoulder. Results indicated multiple significant increases over time among the three joints comprising the shoulder complex in the coronal and transverse planes, despite no increases in thoracohumeral motion, and suggest that thoracohumeral motion alone does not provide a comprehensive assessment. Interestingly, more significant increases were observed at the 6-month evaluation than the 3-month evaluation, which is not aligned with the standard rehabilitation endpoint. Thus, our findings suggest that clinicians should evaluate all joints of the shoulder complex during longer-term rehabilitation assessment. Ultimately, knowledge of patients’ pre-operative and post-operative shoulder complex kinematics may help to improve rehabilitation to promote improved patient outcomes.     

Effects of rotator cuff tears on muscle moment arms: a computational study

Rotator cuff tears cause morphologic changes to cuff tendons and muscles, which can alter muscle architecture and moment arm. The effects of these alterations on shoulder mechanical performance in terms of muscle force and joint strength are not well understood. The purpose of this study was to develop a three-dimensional explicit finite element model for investigating morphological changes to rotator cuff tendons following cuff tear. The subsequent objectives were to validate the model by comparing model-predicted moment arms to empirical data, and to use the model to investigate the hypothesis that rotator cuff muscle moment arms are reduced when tendons are divided along the force-bearing direction of the tendon. The model was constructed by extracting tendon, cartilage, and bone geometry from the male Visible Human data set. Infraspinatus and teres minor muscle and tendon paths were identified relative to the humerus and scapula. Kinetic and kinematic boundary conditions in the model replicated experimental protocols, which rotated the humerus from 45 degrees internal to 45 degrees external rotation with constant loads on the tendons. External rotation moment arms were calculated for two conditions of the cuff tendons: intact normal and divided tendon. Predicted moment arms were within the 1-99% confidence intervals of experimental data for nearly all joint angles and tendon sub-regions. In agreement with the experimental findings, when compared to the intact condition, predicted moment arms were reduced for the divided tendon condition. The results of this study provide evidence that one potential mechanism for the reduction in strength observed with cuff tear is reduction of muscle moment arms. The model provides a platform for future studies addressing mechanisms responsible for reduced muscle force and joint strength including changes to muscle length-tension operating range due to altered muscle and tendon excursions, and the effects of cuff tear size and location on moment arms and muscle forces.     

Arthroscopic surgery compared with supervised exercises in patients with rotator cuff disease (stage II impingement syndrome)

OBJECTIVE--To compare the effectiveness of arthroscopic surgery, a supervised exercise regimen, and placebo soft laser treatment in patients with rotator cuff disease (stage II impingement syndrome). DESIGN--Randomised clinical trial. SETTING--Hospital departments of orthopaedics and of physical medicine and rehabilitation. PATIENTS--125 patients aged 18-66 who had had rotator cuff disease for at least three months and whose condition was resistant to treatment. INTERVENTIONS--Arthroscopic subacromial decompression performed by two experienced surgeons; exercise regimen over three to six months supervised by one experienced physiotherapist; or 12 sessions of detuned soft laser treatment over six weeks. MAIN OUTCOME MEASURES--Change in the overall Neer shoulder score (pain during previous week and blinded evaluation of function and range of movement by one clinician) after six months. RESULTS--No differences were found between the three groups in duration of sick leave and daily intake of analgesics. After six months the difference in improvement in overall Neer score between surgery and supervised exercises was 4.0 (95% confidence interval -2 to 11) and 2.0 (-1.4 to 5.4) after adjustment for sex. The condition improved significantly compared with placebo in both groups given the active treatments. Treatment costs were higher for those given surgery (720 pounds v 390 pounds). CONCLUSIONS--Surgery or a supervised exercise regimen significantly, and equally, improved rotator cuff disease compared with placebo.     

Isolated vs. complex exercise in strengthening the rotator cuff muscle group

The purpose of this study was to compare 2 different training modes in improving shoulder cuff muscular performance. Thirty-nine participants were randomly assigned into 3 groups: the isolated group exercised using 2-kg dumbbells; the complex group used a protocol with complex exercises; and the control group had no training. All participants trained for 6 weeks (3 times per week) and were evaluated isokinetically before (pretest) and after the training period (posttest). Results showed that the complex group significantly improved their muscular performance, but the isolated group did not, indicating that isolated exercises are only effective when the training goal is to strengthen the weaker muscle group, but they must be replaced by more complex and closed-kinetic exercises in order to obtain considerable improvement of the rotator cuff strength. The authors propose that a strengthening program should start with isolated movements for better stimulation of the weaker muscles and continue with complex exercise for more impressive strengthening.     

Arthroscopic treatment of ruptures of the rotator cuff

566 patients with shoulder disease were treated at the Clinic of Orthopaedics at the University Hospital Olomouc. Of these, 181 were operated for ruptures of the rotator cuff (RC). They were categorised according to the Gschwend classification, age and gender(1). Laterality of the operated limb was also evaluated. Patients with ruptures larger than 4 cm were treated by open operation. 84 shoulders with ruptures classified as Gschwend I, II and IIIa -52 males and 32 females-were treated arthroscopically. The age of the operated patients ranged from 40-60 years. In both genders, the right shoulder was more often affected. Two operating techniques were used: 1) Transosseal refixation of the RC muscle tendons, using RC MITEK anchor implants, 2) "End to end" sutures, without implants(2-4). Operating time was reduced to 30-40 min. The operating results were evaluated according to the UCLA criteria- University of California Shoulder Rating Score(2). 45 patients achieved excellent results (53 %), 35 patients had good results (42 %), and 4 patients (5 %) obtained satisfactory results. None of the patients obtained poor results- a score of less than 20 was poor. Patients felt comfortable following the operation and none had any post-operational complications. The author is convinced, along with others, that arthroscopic suturing of RC ruptures classified I-IIIa allows for rupture treatment that in the past had to be treated by open technique(2-5). The deltoid muscle is not affected by arthroscopy. There is normalisation of the patient's movement, pain, force, and rotational stability is comparable to the healthy limb. Treatment time is reduced to a minimum and the patient may soon return to normal daily life.     

Supraspinatus tendon organizational and mechanical properties in a chronic rotator cuff tear animal model

Rotator cuff tears of the shoulder are a common cause of pain and disability. The successful repair of rotator cuff tendon tears depends on the time from onset of injury to the time of surgical repair. However, the effect of time from injury to repair remains poorly understood. A rat model was used to investigate the supraspinatus tendon organizational and mechanical property changes that occur with time post-injury to understand the natural injury response in the absence of repair. It was hypothesized that increased time post-injury would result in increased detrimental changes to tendon organizational and mechanical properties. Tendons were detached at the insertion on the humerus without repair and the quantitative organizational and mechanical properties were analyzed at 1, 2, 4, 8, and 16 weeks post-detachment. Tendon detachment resulted in a dramatic decrease in mechanical properties initially followed by a progressive increase with time. The quantitative collagen fiber orientation results provided corroborating support to the mechanical property data. Based on similarities in histology and mechanical properties to rotator cuff tears in humans, the animal model presented here is promising for future investigations of the tendon's natural injury response in the absence of repair.     

Effect of rotator cuff exercise on humeral rotation torque in healthy individuals

Conservative management of rotator cuff pathology often involves certain therapeutic exercises. Although a major goal of these exercises is to increase strength of the rotator cuff, little empirical evidence supports this assertion. In this study, 34 nonpathologic young adults were pretested using a LIDO Multijoint II isokinetic device for average and peak torque generated during internal and external rotation. Subjects were arbitrarily assigned to a right-arm- or left-arm-trained group, exercised for 4 weeks, and then posttested for changes in humeral rotation torque. Moderate but significant increases in torque (8-10%) as well as in total work done were observed in both groups, only in the trained arm. Subjects who trained the nondominant (left) arm experienced gains similar to those who trained the right arm. Gains were significant in the case of both internal and external rotation (also average as well as peak torque), with men and women experiencing the same relative increases. These data, in addition to supporting the use of selected exercises to increase humeral rotation torque in a healthy population, offer a potential model for the rehabilitation of patients with rotator cuff injury.     

Muscle efficiency in total shoulder prosthesis implantation: dependence on position of the humeral head and rotator cuff function]

Modern shoulder prostheses permit an anatomic reconstruction of the joint, although the biomechanical advantages are not proven. The goal of this study was to investigate the relationship between position of the humeral head and function of the shoulder prosthesis (muscle efficiency). Shoulder elevation-motion and rotator cuff defects were simulated in vitro in a robot-assisted shoulder simulator. The EPOCA Custom Offset shoulder prosthesis (Argomedical AG, Cham, CH) was implanted in seven normal shoulders (77 +/- 20 kg, 55 +/- 14 years). Active elevation was simulated by hydraulic cylinders, and scapulothoratic motion by a specially programmed industrial robot. Muscle efficiency (elevation-angle/muscle-force of the deltoid muscle) was measured in anatomic (ANA), medialised (MED) and lateralised (LAT) positions of the humeral head, with or without rotator cuff muscle deficiency. Medialisation increased efficiency by 0.03 +/- 0.04 deg/N (p = 0.022), lateralisation decreased it by 0.04 +/- 0.06 deg/N (p = 0.009). Supraspinatus muscle deficiency increased the deltoid force required to elevate the arm, and thus decreased efficiency (ANA p = 0.091, MED p = 0.018, LAT p = 0.028). The data confirm that the position of the humeral head affects the mechanics of total shoulder arthroplasty. Medialisation increases efficiency of the deltoid muscle and may prove useful in compensating isolated supraspinatus muscle deficiency. Lateralisation, in contrast, leads to an unfavorable situation.     

Ruptures of the rotator cuff.

Through the use of improved diagnostic techniques, including arthrography and arthroscopy, ruptures of the rotator cuff that previously might not have been recognized are now being identified more frequently. In most cases the symptoms are relatively mild and respond satisfactorily to rest and therapy. Occasionally, however, there is severe, persistent disability despite treatment. These ruptures require surgical repair. In such cases the data obtained from special investigations help the surgeon select the appropriate surgical approach and repair technique. An imaginative program of physiotherapy before and after the operation contributes greatly to a satisfactory result.     

Difference in isokinetic torque acceleration energy of the rotator cuff: competitive male pitchers versus male nonathletes

Rotator cuff function is critical to the overhead athlete. Rotator cuff power is felt to be important in the overhead athlete during the throwing motion. Little research exists regarding torque acceleration energy (TAE) in overhead athletes. Twenty-five males were divided into 2 groups consisting of overhead athletes (pitchers) (n = 12) and nonoverhead athletes (controls) (n = 13). All participants were given a concentric velocity spectrum isokinetic test at speeds of 60 degrees (1.05 r), 180 degrees (3.16 r), and 300 degrees.s(-1) (5.26 r) to both the dominant and nondominant shoulder internal and external rotators. Significant differences were found for all internal rotator TAE scores (p = 0.000-0.016), at each of the 3 velocities, when comparing dominant to nondominant arms of both overhead athletes and nonoverhead athletes. Only 60 degrees.s(-1) (1.05 r) was found to be different during external rotation TAE testing of the overhead athletes (p = 0.027) but was not found in the control subjects. Post hoc analysis revealed no differences between dominant or nondominant TAE scores when comparisons were made between overhead athletes and controls. Results may reveal that power of the rotator cuff muscles may not be a critical component of the overhead throwing motion.     

Direction-specific recruitment of rotator cuff muscles during bench press and row

Recent studies indicate that rotator cuff (RC) muscles are recruited in a reciprocal, direction-specific pattern during shoulder flexion and extension exercises. The main purpose of this study was to determine if similar reciprocal RC recruitment occurs during bench press (flexion-like) and row (extension-like) exercises. In addition, shoulder muscle activity was comprehensively compared between bench press and flexion; row and extension; and bench press and row exercises. Electromyographic (EMG) activity was recorded from 9 shoulder muscles sites in 15 normal volunteers. All exercises were performed at 20, 50 and 70% of subjects’ maximal load. EMG data were normalized to standard maximal voluntary contractions. Infraspinatus activity was significantly higher than subscapularis during bench press, with the converse pattern during the row exercise. Significant differences in activity levels were found in pectoralis major, deltoid and trapezius between the bench press and flexion exercises and in lower trapezius between the row and extension exercises. During bench press and row exercises, the recruitment pattern in each active muscle did not vary with load. During bench press and row exercises, RC muscles contract in a reciprocal direction-specific manner in their role as shoulder joint dynamic stabilizers to counterbalance antero-posterior translation forces.     

Stem cell therapy in the management of shoulder rotator cuff disorders

Rotator cuff tears are frequent shoulder problems that are usually dealt with surgical repair. Despite improved surgical techniques, the tendon-to-bone healing rate is unsatisfactory due to difficulties in restoring the delicate transitional tissue between bone and tendon. It is essential to understand the molecular mechanisms that determine this failure. The study of the molecular environment during embryogenesis and during normal healing after injury is key in devising strategies to get a successful repair. Mesenchymal stem cells (MSC) can differentiate into different mesodermal tissues and have a strong paracrine, anti-inflammatory, immunoregulatory and angiogenic potential. Stem cell therapy is thus a potentially effective therapy to enhance rotator cuff healing. Promising results have been reported with the use of autologous MSC of different origins in animal studies: they have shown to have better healing properties, increasing the amount of fibrocartilage formation and improving the orientation of fibrocartilage fibers with less immunologic response and reduced lymphocyte infiltration. All these changes lead to an increase in biomechanical strength. However, animal research is still inconclusive and more experimental studies are needed before human application. Future directions include expanded stem cell therapy in combination with growth factors or different scaffolds as well as new stem cell types and gene therapy.     

Comparison between line and surface mesh models to represent the rotator cuff muscle geometry in musculoskeletal models

Accurate muscle geometry (muscle length and moment arm) is required to estimate muscle function when using musculoskeletal modelling. In shoulder, muscles are often modelled as a collection of independent line segments, leading to non-physiological muscles trajectory, especially for the rotator cuff muscles. To prevent this, a surface mesh model was developed and validated against 7 MRI positions in one participant. Mean moment arm errors was 11.4% for the line vs. 8.8% for the mesh model. While the model with independent lines led to some non-physiological trajectories, the mesh model gave lower misestimations of muscle lengths and moment arms.     

Electromyographic analysis of rotator cuff muscles in patients with rotator cuff tendinopathy: A systematic review

The shoulder is inherently an unstable joint which heavily relies on the neuromuscular activation of the rotator cuff (RC) complex for stability during movement. Currently, there is no consensus regarding how the activity of RC muscles is affected among individuals with a RC tendinopathy (RCTe). This study reviewed the evidence of studies comparing the electromyographic (EMG) activity of any RC muscle of shoulders with a symptomatic RCTe to asymptomatic shoulders. Eight databases were searched. Data from 343 participants (201 symptomatic and 209 asymptomatic shoulders) were analyzed from 10 out of 402 included studies. Strong evidence for the infraspinatus and supraspinatus during isometric contractions and limited evidence for the supraspinatus and infraspinatus during isokinetic contractions suggest that the muscular activity is not altered among individuals with a RCTe during these types of contraction. Very limited evidence indicates reduced muscle activity for the infraspinatus and subscapularis in the presence of a RCTe during isotonic contractions, and no alterations for the supraspinatus or teres minor were identified. Lastly, conflicting to moderate evidence suggests alterations in RC muscle activity during unrestrained movements and swimming. These findings indicate that EMG deficits associated with a RCTe can best be appreciated during unrestrained movements.     

Low-dose CT imaging of radio-opaque markers for assessing human rotator cuff repair: accuracy, repeatability and the effect of arm position

Previous studies have used radiostereometric analysis (RSA) to assess the integrity and mechanical properties of repaired tendons and ligament grafts. A conceptually similar approach is to use CT imaging to measure the 3D position and distance between implanted markers. The purpose of this study was to quantify the accuracy and repeatability of measuring the position and distance between metallic markers placed in the rotator cuff using low-dose CT imaging. We also investigated the effect of repeated or variable positions of the arm on position and distance measures. Six human patients had undergone rotator cuff repair and placement of tantalum beads in the rotator cuff at least one year prior to participating in this study. On a single day each patient underwent nine low-dose CT scans in seven unique arm positions. CT scans were analyzed to assess bias, precision and RMS error of the measurement technique. The effect of repeated or variable positions of the arm on the 3D position of the beads and the distance between these beads and suture anchors in the humeral head were also assessed. Results showed the CT imaging method is accurate and repeatable to within 0.7 mm. Further, measures of bead position and anchor-to-bead distance are influenced by arm position and location of the bead within the rotator cuff. Beads located in the posterior rotator cuff moved medially as much as 20 mm in abduction or external rotation. When clinically relevant CT arm positions such as the hand on umbilicus or at side were repeated, bead position varied less than 4 mm in any anatomic direction and anchor-to-bead distance varied +2.8 to -1.6 mm (RMS 1.3 mm). We conclude that a range of ± 3 mm is a conservative estimate of the uncertainty in anchor-to-bead distance for patients repeatedly scanned in clinically-relevant arm positions.