Internal impingement in the shoulder

Current wisdom holds that the acromion is a major factor in the development of rotator cuff impingement. From the examination of a large number of skeletal specimens (1232 shoulders), we conclude that this view may require some modification. It appears that internal impingement between the glenoid and the humeral head may also be a significant mechanism in the development of rotator cuff pathosis. We present here the evidence for this internal impingement, which is expressed in characteristic telltale patterns impressed into the bones on both sides of the joint. If this thesis is correct, the rationale for some acromioplasty operations may be called into question, currently the most popular procedure in shoulder surgery.     

肩峰撞击综合征的关节镜下治疗

目的评价肩关节镜下治疗肩峰撞击综合征的临床效果。方法2009年1月-2012年1月,对20例肩峰撞击综合征患者于肩关节镜下行肩峰成形术,术后采用Neer法进行评分。结果术后随访10-25个月,平均15个月,本组患者均未出现关节感染、血管神经损伤及关节腔积血等并发症。肩关节功能术前和术后依据Neer评分系统分别为（78．5±3．0）分及（92．0±2．6）分（P〈0．01）。结论肩关节镜下肩峰成形术能有效治疗肩峰撞击综合征。     

Internal impingement of the shoulder in flexion

Contact of the rotator cuff to the superior glenoid with the arm in flexion has been described and postulated to be a source of rotator cuff disease. The goals of the current study were to document the existence of internal impingement in flexion arthroscopically and to determine its prevalence in patients with various diseases. Also, we attempted to determine the clinical significance of internal impingement in flexion by investigating the associations between internal impingement in flexion and the preoperative and intraoperative findings. A consecutive case series of 376 patients having arthroscopy of the shoulder were entered prospectively into this study. During arthroscopy, intraarticular lesions were evaluated and the presence of contact of the rotator cuff to the superior glenoid and the degree of flexion making the contact were noted. Statistical analysis was done with two dependent variables defined: the presence of internal impingement in flexion and the flexion degree making internal impingement in flexion. Of the 376 patients, 277 (74%) had internal impingement in flexion and 99 (26%) did not have internal impingement in flexion. There were no statistically significant differences in the prevalence of internal impingement in flexion according to the primary diagnoses. Statistical analysis revealed that the presence of internal impingement in flexion was associated with Type II superior labrum anterior posterior (SLAP) lesions and the presence of internal impingement of the rotator cuff to the superior glenoid in abduction and external rotation. There was a significant relationship between rotator cuff disease and decreasing angle of contact for internal impingement in flexion. This study showed that internal impingement in flexion is common in a cohort of patients having shoulder surgery, with an overall prevalence of 74%, and that internal impingement in flexion may contribute to the development of Type II SLAP lesions and rotator cuff disease.     

Anterosuperior impingement of the shoulder as a result of pulley lesions: a prospective arthroscopic study

Lesions of the biceps pulley and the rotator cuff have been reported to be associated with an internal anterosuperior impingement (ASI) of the shoulder. The purpose of this study was to determine the factors influencing the development of an ASI. Eighty-nine patients with an arthroscopically diagnosed pulley lesion were prospectively included in this study. Four patterns of intraarticular lesions could be identified. Twenty-six patients (group 1) showed an isolated lesion of the superior glenohumeral ligament (SGHL). In 21 patients (group 2) an SGHL lesion and a partial articular-side supraspinatus tendon tear were found. Twenty-two patients (group 3) had an SGHL lesion and a deep surface tear of the subscapularis tendon, and in twenty patients (group 4) a lesion of the SGHL combined with a partial articular-side supraspinatus and subscapularis tendon tear was diagnosed. Of the patients, 80 (89.9%) showed involvement of the long head of the biceps tendon including synovitis, subluxation, dislocation, and partial or complete tearing. In 43.8% of all patients, ASI was observed. Whereas ASI was seen in 26.6% and 19.1% of patients in groups 1 and 2, respectively, 59.1% of patients in group 3 and 75% of patients in group 4 were found to have an ASI. ASI was significantly more often seen in patients with additional partial articular-side subscapularis tendon tears (P <.0001). In patients with acromioclavicular (AC) arthritis, ASI (62.5%) was more frequently observed than in patients without AC arthritis (P =.0309). In the multivariate analysis the stepwise selection procedure revealed only AC arthritis and the deep surface tear of the subscapularis (groups 3 and 4) to be significant influencing factors for an ASI. Our findings indicate that a progressive lesion of the pulley system, including partial tears of the subscapularis and supraspinatus tendons, contributes significantly to the development of an ASI. A pulley lesion leads to instability of the long head of the biceps tendon, causing increased passive anterior translation and upward migration of the humeral head, resulting in an ASI. In addition, a partial articular-side subscapularis and supraspinatus tendon tear reinforces the ASI.     

High patient satisfaction after arthroscopic subacromial decompression for shoulder impingement: a prospective study of 50 patients

BACKGROUND: Arthroscopic subacromial decompression (ASD) for shoulder impingement has gained popularity. We evaluated the result of this common procedure prospectively, from a patient perspective. METHOD: We used the Disability of the Arm, Shoulder and Hand questionnaire (DASH) and the Visual Analogue Scale (VAS) to evaluate 50 patients with a mean age of 49 (27-72) years. All patients had undergone 6 months of failed nonoperative treatment prior to surgery. Exclusion criteria were total rotator cuff rupture, shoulder instability, clinically verified acromioclavicular joint osteoarthritis, calcifying tendonitis or neurological symptoms. All the decompressions were done by experienced shoulder arthroscopists. RESULTS: A significant improvement in both the median DASH score and the VAS had occurred 6 months after surgery. INTERPRETATION: ASD for impingement in properly selected patients performed by experienced surgeons gives a high degree of patient satisfaction 6 months after surgery.     

Subacromial impingement: open versus arthroscopic decompression.

An analysis of the follow-up results of 53 patients treated by an arthroscopic decompression (AD) and 53 patients treated by an open decompression (OD) is presented. Patients were evaluated pre- and postoperatively with the UCLA Shoulder Rating Scale, which includes an assessment of pain, function, range of motion, strength, and patient satisfaction. After an average of 20.1 months for the AD group and 27.3 months for the OD group, good or excellent results were found in 83.1% in the AD group and in 81.1% in the OD group. Patient satisfaction was 88.3% (AD) compared with 94.3% (OD). Results of decompression in both groups were not influenced by associated pathologies (acromioclavicular degeneration, frozen shoulder, calcified tendinitis, rotator cuff lesions).     

In vivo analysis of coracoid and subacromial shoulder impingement mechanism during clinical examination

Background

Understanding the mechanisms of shoulder impingement created by clinical tests is crucial to accurately evaluate the condition. The objective of this study was to relate mechanisms of subacromial and coracoid impingement occurring in positions of the shoulder during clinical examination, in quantitative and qualitative terms.

Methods

A 1.0T open magnetic resonance imaging system was used in 18 female and 19 male subjects, to determine the distances between the humeral head and the acromion or coracoid, and contact with the rotator cuff (RC). Measurements were taken with the shoulder in neutral, “Hawkins”, “Neer”, and 90° abduction/15° internal rotation (horizontal impingement test) positions. Additionally, impingement was classified based on the grade of RC contact with the acromion or coracoid.

Results

In the Hawkins position, distance between the supraspinatus and the coracoid was closest (14.5 ± 4.5 mm), while the coracohumeral distance (CHD) narrowed (p < 0.001). In the horizontal impingement test position, the minimum distance between the subscapularis and coracoid was found, whereas the CHD increased (27.4 ± 5.7 mm). In the Neer and Hawkins positions, the space between the greater tuberosity and acromion was significantly narrowed, which was also the case in the horizontal impingement test position compared to neutral position (p < 0.001).

Conclusion

Shoulder movements of forward flexion and internal rotation (Hawkins test) and abduction and internal rotation (horizontal impingement test) can lead to different coracoid impingement mechanisms during clinical examination. The Hawkins, Neer, and horizontal impingement tests lead to comparable narrowed acromiohumeral distances and subacromial contact of the RC.

Level of evidence

Therapeutic level III.

     

Posttraumatic anterior-inferior instability of the shoulder: arthroscopic findings and clinical correlations

Introduction: The main purpose of our study was to evaluate intra-articular lesions in glenohumeral-instability with arthroscopy and correlate them with clinical findings as well as history of instability. Material and methods: In this prospective multi-centre study, we evaluated arthroscopic findings in 303 patients with posttraumatic anterior-inferior instability of the shoulder. The study cohort was divided into 2 groups: patients with a history of one dislocation (Group 1, n=61, 20.1%) and patients with a history of more than one dislocation (Group 2, n=242, 79.9%). Results: In Group 1, 37 patients had an IGHL-lesion, 31 a MGHL-lesion and 41 a Hill-Sachs lesion. In Group 2, 182 patients had an IGHL-lesion, 172 a MGHL-lesion and 203 a Hill-Sachs lesion. The percentage of lesions in Group 2 (IGHL-75.2%, MGHL-71.1%, Hill-Sachs-83.9%) was significantly higher than in Group 1 (IGHL-60.7%, MGHL-50.8%, Hill-Sachs-67.2%, P=0.0233, P=0.0026, and P=0.0033, respectively). Within Group 2 we found significantly more Hill-Sachs-lesions with a history of an increasing number of recurrences (P=0.0436). We also found an increase of IGHL- and MGHL-lesions with an increasing number of recurrences, but this difference was not significant. The distribution of lesion types of the anterior labrum-ligament complex showed no significant difference between the two groups, apart from a higher incidence of ALPSA-lesions within Group 2 (34.7% versus 18.0% in Group 1). The results of this study show that recurrences after primary posttraumatic anterior-inferior shoulder dislocation cause increasing ligamental damage as well as increasing Hill-Sachs lesions within the gleno-humeral joint. Conclusion: Thus we conclude that early surgical stabilization after posttraumatic anterior-inferior shoulder dislocation is necessary to prevent increasing damage within the shoulder joint.     

Internal impingement in the shoulder of the overhand athlete: pathophysiology, diagnosis, and treatment

The etiology of rotator cuff disease is multifactorial in nature. The process by which the articular surface of the rotator cuff can become diseased secondary to direct abutment against the glenoid rim and labrum has been termed internal impingement. Damage to the undersurface of the rotator cuff can occur from contact at the extremes of shoulder motion and can increase secondary to adaptive changes in bone and soft tissue. Diagnosis is achieved in most instances by a thorough physical examination. Adjunctive tests, particularly magnetic resonance imaging, can increase the accuracy of the diagnosis. If this disease is recognized early, nonoperative intervention may be successful. When nonoperative treatment fails, the use of arthroscopy for the treatment of torn rotator cuff and labral tissue and capsular laxity may be indicated to resolve symptoms and restore the premorbid level of function.     

Internal impingement of the shoulder: comparison of findings between the throwing and nonthrowing shoulders of college baseball players.

The authors evaluated and compared the findings of gadolinium-enhanced magnetic resonance imaging (MRI) studies of throwing and nonthrowing shoulders in college baseball athletes and contrasted these findings with the clinical examination results. Ten throwing college baseball athletes were prospectively clinically examined for instability, range of motion, impingement signs, and relocation testing, then evaluated with bilateral gadolinium enhanced MRI using the nonthrowing shoulder as a control. All MRIs were performed on a 1.5-Tesla magnet and included routine adduction images and images obtained in abduction and external rotation (ABER). Studies were interpreted by a musculoskeletal radiologist and an orthopaedic surgeon specializing in shoulder surgery. In all shoulders, ABER imaging showed physical contact between the undersurface of the rotator cuff and the posterior superior glenoid. No imaging or physical examination abnormalities were identified in the nonthrowing shoulders. Three of 10 throwing shoulders had superior labral tears and adjacent paralabral cysts extending toward or into the spinoglenoid notch. Four of 10 throwing shoulders had abnormal signal change in the rotator cuff tendons. No correlation was identified between positive MRI findings and instability on physical examination. Physical contact between the rotator cuff undersurface and the subjacent labrum can be seen normally in the ABER position. Abnormalities of the rotator cuff and superior labrum are seen in asymptomatic throwing shoulders but not nonthrowing shoulders. MRI abnormalities consistent with internal impingement can be seen in asymptomatic patients. Treatment of these abnormalities in young throwing athletes should be approached with caution.     

Patients with shoulder impingement remain satisfied 6 years after arthroscopic subacromial decompression: a prospective study of 46 patients

Background

Although arthroscopic subacromial decompression (ASD) is a common procedure for treatment of shoulder impingement, few long term results have been published. In this prospective study, we determined whether the high degree of patient satisfaction at 6 months postoperatively reported by us earlier remained at the 6-year follow-up.

Patients and methods

We originally reported high patient satisfaction 6 months after ASD for shoulder impingement in 50 prospectively studied patients using the Disability of the Arm Shoulder and Hand questionnaire (DASH) and the Visual Analog Scale (VAS). Patients with associated shoulder disorders were excluded. The surgeons were experienced shoulder arthroscopists. 6 years after surgery, the DASH questionnaire and the VAS were sent to these 50 patients. 2 patients had other medical problems of the upper extremity that affected the DASH and VAS scores, 1 patient was lost to follow-up, and another refused to participate. Thus, 46 patients with a mean age of 55 (33–78) years were included in this 6-year evaluation.

Results

The considerable improvement in both the DASH score and the VAS that was observed 6 months after surgery persisted or had even improved 6 years after surgery.

Interpretation

Properly selected patients with shoulder impingement treated with ASD remain satisfied 6 years after surgery.Patients with shoulder impingement may have associated conditions such as painful osteoarthrosis of the acromioclavicular joint, degenerative biceps tendon, or rotator cuff tear. There have been few studies describing the long-term results of arthroscopic subacromial decompression (ASD) for patients with pure shoulder impingement, especially from the standpoint of patient satisfaction. The Constant-Murley score (1987) is commonly used; it provides objective information including strength and range of motion. The DASH score reflects the patient''s own experience of disability and is used to study rotator cuff disorders (Norlin and Adolfsson 2008, Björnsson et al. 2010). Pain is the main complaint in shoulder impingement patients. Thus, it is important to compare preoperative and postoperative pain to evaluate the surgical results. The VAS is a validated and widely accepted tool that measures the severity of pain.We have already reported that ASD in properly selected patients with impingement is an operation that gives high patient satisfaction 6 months after surgery when using DASH and VAS as evaluation tools (Bengtsson et al. 2006). We have now evaluated the patients 6 years after surgery.     

Open versus arthroscopic shoulder stabilization. An analysis of the treatment costs

In this study the total costs of clinical open and arthroscopic anterior shoulder stabilization were evaluated, analyzed and compared. From 1988 to 1998 147 patients underwent open (Bankart) or arthroscopic (ASK) anterior shoulder stabilization. We randomized two groups of 30 patients for each method (Bankart: 25 male, 5 female, 29 years of age; ASK: 25 male, 5 female, 26 years of age) and evaluated the costs of their clinical treatment. The total cost was significantly ( p<0.05, Mann-Whitney U-Test) higher for the open (5639 euro) than for the arthroscopic (4601 euro) therapy. There was a significant difference between the groups for the average cost of surgery (Bankart: 2741 euro; ASK: 2315 euro, p<0.05) and the average postoperative treatment cost (Bankart: 2202 euro; ASK: 1630 euro, p<0.05) whereas the average preoperative treatment cost was not significantly different (Bankart: 669 euro, ASK: 657 euro). The staff costs for the surgical procedure (Bankart: 1800 euro (32%), ASK: 1319 euro (29%)) and the postoperative staff costs of the nurses (Bankart: 1271 euro (23%), ASK: 997 euro (22%)) represented the greatest parts of the total costs. The average duration of the clinical treatment was 15.8 days for the open- and 12,4 days for the arthroscopic group.     

Posterior shoulder instability: comprehensive analysis of open and arthroscopic approaches

Whether open surgery and arthroscopic repair of posterior shoulder instability have similar success rates remains unknown, but the literature suggests that arthroscopic soft-tissue stabilization procedures equal open surgery in managing posterior shoulder instability. A comprehensive PubMed computer search of the English-language literature from 1988 to 2004 was performed using the key phrase posterior shoulder instability. Studies included in our analysis addressed the surgical treatment of recurrent posterior instability and multidirectional instability with primarily a posterior component of instability; studies were excluded if their minimum follow-up was less than 1 year, if their patients had a history of habitual posterior shoulder instability, or if their patients had either bony procedures or thermal capsulorrhaphy. Data collected from each study included patient demographics, instability classifications (traumatic vs atraumatic), previous shoulder stabilizations, and clinical outcomes. After identifying and reviewing 283 abstracts, we found that 16 articles fulfilled the inclusion criteria--9 open studies (173 patients) and 7 arthroscopic trials (186 patients). The 2 treatment groups had similar sex distributions (P> .25). Mean age was 23 years for the open group and 26 years for the arthroscopic group (P< .02). Clinical outcomes were rated satisfactory by 72% of patients in the open group and 83% of patients in the arthroscopic group (P< .55), controlling for age. Eighty-five percent of patients treated with an open technique and 81% of patients treated arthroscopically returned to sports (P< .82). This study demonstrated no statistical difference in clinical outcomes for patients treated with either open or arthroscopic surgery for posterior shoulder instability.     

Early degenerative joint disease simulating impingement syndrome: arthroscopic findings.

Eighteen patients who underwent shoulder arthroscopy for impingement syndrome were shown at operation to have coexisting glenohumeral degenerative joint disease (DJD) which was not apparent during preoperative clinical and radiographic evaluation. Because traditional ("open") techniques of anterior acromioplasty do not allow inspection of the glenohumeral joint, it is almost certain that this pathology would have been missed at operation if open acromioplasty had been performed. We conclude that arthroscopic subacromial decompression (ASD), by allowing easy inspection of the glenohumeral joint, offers a distinct advantage over traditional acromioplasty. Furthermore, arthroscopic evaluation of some of these patients' glenohumeral joints provided us with evidence supporting the existence of subluxation arthropathy. We have also developed a new clinical test, the "compression-rotation" test, which has been helpful in distinguishing patients with both impingement syndrome and early DJD syndrome from those with isolated impingement syndrome. Although patients in this study appeared to be doing well at short-term follow-up status post-ASD and glenohumeral debridement, no long-term results are yet available.     

肩关节镜术后肩峰下间隙镇痛的临床研究（英文）

[目的]观察肩峰下间隙自控镇痛用于肩关节镜术后镇痛效果和不良反应。[方法]选择关节镜下肩峰成形术患者60例,采用随机数字表法随机分为两组,肩峰下间隙自控镇痛组(SA-PCA)和静脉自控镇痛组(IV-PCA)。SA-PCA组为0.2%的罗哌卡因持续泵注背景剂量为5 ml/h,负荷量为8 ml,单次剂量为5 ml,按压锁定时间20 min;IA-PCA组为2μg/ml的舒芬太尼持续泵注背景剂量为2 ml/h,负荷量为2 ml,单次剂量为2 ml,按压锁定时间20 min。观察术后2、6、12、24、48 h的静态、动态VAS评分、不良反应以及镇痛泵的使用情况,患者对镇痛总体满意度。[结果]SA-PCA组在静息状态下的VAS评分与IV-PCA无明显差别,SA-PCA组在活动状态下的VAS评分明显低于IV-PCA组(P<0.05),SA-PCA组的不良反应发生率低于IV-PCA组(P<0.05),SA-PCA组患者的总体满意度高于IV-PCA组患者的总体满意度(P<0.05)。[结论]肩峰下间隙自控镇痛用于肩关节镜术后可起到良好的镇痛效果且不良反应发生率较低。     

Arthroscopic management of the thrower's shoulder: internal impingement

Our understanding of internal impingement in the overhand athlete is an evolving body of knowledge. More recent improved understanding of the pathophysiology of events that leads to the spectrum of injury has caused us to refine our techniques of treatment. Improved surgical techniques and instrumentation have made refinement of our approach to treatment possible. Only time will tell whether the perceived understanding of these disorders, resulting in alteration of our treatment methods, is making our treatment outcomes more successful.