Shoulder muscle activation and coordination in patients with a massive rotator cuff tear: an electromyographic study

Adaptive muscle activation strategies following a massive rotator cuff tear (MRCT) are inadequately understood, and the relationship among muscles during everyday activities has not been considered. Thirteen healthy subjects comprised the control group, and 11 subjects with a MRCT the patient group. Upper limb function was assessed using the Functional Impairment test‐hand, neck, shoulder, and arm (FIT‐HaNSA). Electromyography (EMG) was recorded from 13 shoulder muscles, comprising five muscle groups, during a shelf‐lifting task. Mean FIT‐HaNSA scores were significantly lower in MRCT patients (p ≤ 0.001), reflecting a severe functional deficit. In MRCT patients, EMG signal amplitude was significantly higher for the biceps brachii‐brachioradialis (p < 0.001), upper trapezius‐serratus anterior (p = 0.025), muscle groups and for the latissimus dorsi (p = 0.010), and teres major (p = 0.007) muscles. No significant differences in the correlation among muscle groups were identified, pointing to an unchanged neuromuscular strategy following a tear. In MRCT patients, a reorganization of muscle activation strategy along the upper limb kinetic chain is aimed at reducing demand on the glenohumeral joint. Increased activation of the latissimus dorsi and teres major muscles is an attempt to compensate for the deficient rotator cuff. Re‐education towards an alternate neuromuscular control strategy appears necessary to restore function. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1140–1146, 2012     

关节镜下治疗大型肩袖撕裂

目的探讨肩关节镜下治疗大型肩袖撕裂的方法和疗效。方法对34例大型肩袖撕裂患者在关节镜下行单排或双排FastTakII锚钉止点重建术。应用美国肩肘外科医师协会评价系统（ASES）和加利福尼亚大学洛杉矶分校（UCLA）肩关节标准评分。结果34例均获随访,时间4．5～40（7．7±2．4）个月。术后患肩在主动上举、内收、后伸、外展、外旋和内旋6个方向的活动度较术前均有改善（P〈0．05）;患肩完成10项13常活动能力：术前为8．45分±O．97分,术后提高至24．60分±1．21分（P〈0．05）;ASES和UCLA评分：术前分别为24．64分±2．44分和8．06分±1．47分,术后分别提高至71．15分±1．28分和21．77分±1．16分（P〈0．05）;VAS评分：术前为7．18分±2．33分,术后为3．43分±1．75分（P〈0．05）。结论肩关节镜下肩袖重建手术微创治疗优势显著,3～5个作业通道和专业化手术器械的合理交替配合操作能满足大型肩袖撕裂止点重建需求,经镜下双排或单排锚钉重建后的大型损伤肩袖稳定性良好,肩关节功能改善明显。     

Rotator cuff tears

Rotator cuff disease is a common cause of pain and weakness in the shoulder. This article examines the anatomy and function of the rotator cuff; and the incidence, pathogenesis, evaluation, treatment and prognosis of rotator cuff tears.     

Midterm clinical outcomes following arthroscopic transosseous rotator cuff repair

Purpose:Arthroscopic transosseous (TO) rotator cuff repair has recently emerged as a new option for surgical treatment of symptomatic rotator cuff tears. Limited data is available regarding outcomes using this technique. This study evaluated midterm clinical outcomes following a novel arthroscopic TO (anchorless) rotator cuff repair technique.Results:Statistically significant improvements were noted in forward flexion, external rotation and internal rotation (P < 0.0001). Average postoperative subjective shoulder value was 93.7, simple shoulder test 11.6, and American Shoulder and Elbow Surgeons (ASES) score 94.6. According to ASES scores, results for the 109 shoulders available for final follow-up were excellent in 95 (87.1%), good in 8 (7.3%), fair in 3 (2.8%), and poor in 3 (2.8%). There was no difference in ROM or outcome scores in patients who underwent a concomitant biceps procedure (tenodesis or tenotomy) compared with those who did not. Furthermore, there was no significant difference in outcome between patients who underwent either biceps tenodesis or tenotomy. Age, history of injury preceding the onset of pain, tear size, number of TO tunnels required to perform the repair, and presence of fatty infiltration did not correlate with postoperative ROM or subjective outcome measures at final follow-up. Two complications and four failures were noted.Conclusions:Arthroscopic TO rotator cuff repair technique leads to statistically significant midterm improvement in ROM and satisfactory midterm subjective outcome scores with low complication/failure rates in patients with average medium-sized rotator cuff tears with minimal fatty infiltration. Further work is required to evaluate radiographic healing rates with this technique and to compare outcomes following suture anchor repair.

Level of Evidence:

Level IV     

Results of the repair of acute rotator cuff tears is not influenced by tear retraction

Purpose:

This study evaluated retraction in the setting of acute rotator cuff tears and determined its effects on patient outcomes and tendon repair integrity.

Materials and Methods:

A total of 22 patients had surgery within 6 weeks or less from the time of injury. Fifteen of these patients were prospectively followed at a minimum of 2 years; average 40.5 months (range 24-69). Pre-operative objective and subjective outcomes were compared. Tendon repair integrity was assessed with ultrasound at a minimum of 1 year from surgery. The population was stratified into Group 1 (8 patients) with minimal intra-operative medial tendon retraction to the mid-line level of the humeral head and Group 2 (7 patients) with a large medial tendon retraction to the glenohumeral joint or greater.

Results:

The average time to surgery from the onset of symptoms was 27 days (range, 6-42). Post-operative motion increased significantly for external rotation and forward elevation, 77% of patients were pain free, 80% were completely satisfied, and 100% would have the surgery again. Group 1 (small retraction) versus Group 2 (large retraction) showed that post-operative pain levels, satisfaction, range of motion, strength, subjective shoulder value (95.4% vs. 92.3%), Constant Score (80.8 vs. 78.1), and American Society of Shoulder and Elbow Surgeons (96.2 vs. 93.5) scores were not statistically different. Ultrasound showed a tendon repair integrity rate of 87%. 2 patients who did have a re-tear were in Group 2, yet had comparative outcomes.

Conclusion:

In acute rotator cuff tears, equal patient satisfaction, pain scores, range of motion, strength, and outcome measures should be expected with surgical repair despite the level of retraction.

Level of Evidence:

Therapeutic level IV     

Resurfacing arthroplasty for contained cuff tear arthropathy

Cuff tear arthropathy has been among the most difficult management problems faced by the shoulder surgeon. Ability to restore motion and alleviate pain has been challenging and has led Neer to coin the term “limited goals” when discussing outcomes of surgery in this group of patients. Over the past 15 years evidence of improved outcomes has been demonstrated with use of the reverse total shoulder prosthetic implant. However, with longer follow-up, a high rate of complication has also been demonstrated with these implants. Furthermore, their utilization significantly affects the local anatomy and takes away a significant amount of native bone stock. In addition, these implants cost in many cases, three to four times the price of a more conventional prosthesis. Not all patients with cuff tear arthropathy have the same degree of pathology. Many patients retain a “captured” humeral head underneath the coracoacromial arch without demonstrating anterior/superior escape and can be managed with a more conventional prosthesis. Indiscriminate use of the reverse prosthesis on all patients with cuff tear arthropathy presents a relatively reckless and irresponsible use of resources while limiting the ability to perform revision in the face of implant failure. Use of a CTA humeral head implant or cup resurfacing in a valgus position provides a seamless covering over the humeral head, which allows smooth seating within a “socket” formed by the coracoacromial arch. Such patients function quite well with excellent pain relief. Should revision ultimately be needed at a later date, a reverse arthroplasty can easily be performed without damage to the existing architecture. Reverse arthroplasty should be reserved for the physiologically older patient with limited demands and anterior/superior escape of the humeral head. Valgus resurfacing should be the procedure of choice in younger, more active patients whose humeral head remains captured within the coracoacromial arch.     

Glenohumeral interposition of a torn rotator cuff in a young motorcyclist

This report describes the rare case of a traumatic rotator cuff tear in a young patient which led to a pseudoparalysed shoulder by interposition of the tendon stump into the glenohumeral joint. The patient underwent an open rotator cuff repair and regained an almost normal shoulder function after 12 weeks. A review of the literature is presented.     

Dynamic ultrasonography to evaluate coracoacromial ligament displacement during motion in shoulders with supraspinatus tendon tears

We evaluated coracoacromial ligament (CAL) displacement during motion in shoulders with supraspinatus tendon tears by dynamic ultrasonography (US). Twenty subjects with unilateral, full‐thickness supraspinatus tendon tears (SST group) and 20 subjects with intact supraspinatus tendons (control group) underwent dynamic US. The CAL displacement in their bilateral shoulders was measured in the transverse US view during passive and active shoulder abduction and internal rotation (SAIR). In the SST group, the CAL displacement was significantly greater in the affected shoulders than in the intact ones (1.9 mm ± 0.8 mm vs. 1.5 mm ± 0.5 mm, p = 0.01) during passive SAIR, but was not significantly different between the shoulders (1.7 mm ± 0.7 mm vs. 1.7 mm ± 0.4 mm, p = 0.81) during active SAIR. In the control group, no difference in the CAL displacement between the shoulders was noted during passive and active SAIR. Thus, dynamic US revealed greater CAL displacement in shoulders with supraspinatus tendon tears than in intact ones during passive SAIR. Dynamic US may help to detect abnormal kinematics in shoulders with such injury. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1430–1434, 2012     

Rotator cuff tears

Rotator cuff tears are a common cause of pain and weakness in the shoulder. We describe the anatomy and function of the normal rotator cuff, before an overview of cuff tears, with reference to their incidence and pathogenesis. Finally, we discuss clinical presentation, examination findings, treatment options and the prognosis of cuff tears. The authors of this article hope to enable the reader to understand rotator cuff disease, assess patients with suspected rotator cuff tears and discuss the basic treatment options with patients.