Can coracoacromial ligament degeneration be evaluated with preoperative MRI?

BACKGROUND: Subacromial impingement syndrome is one of the most common causes of painful shoulder in the middle-aged and elderly population. Coracoacromial ligament (CAL) degeneration is a well-known indicator for subacromial impingement. PURPOSE: To examine the relationship between CAL thickness on preoperative magnetic resonance imaging (MRI), arthroscopic CAL degeneration and types of rotator cuff tears. MATERIAL AND METHODS: Video records of patients who underwent arthroscopic shoulder surgery between 2015 and 2021 were retrospectively scanned through the hospital information record system. In total, 560 patients were included in this study. Video records of the surgery were used to evaluate the grade of coracoacromial ligament degeneration and the type of cuff tear. Preoperative MRI was used to measure CAL thickness, acromiohumeral distance, critical shoulder angle, acromial index, and acromion angulation. RESULTS: Significant differences were observed between grades of CAL degeneration in terms of CAL thickness (P < 0.001). As CAL degeneration increases, the mean of CAL thickness decreases. According to the results of post-hoc analysis, the mean CAL thickness of normal patients was significantly higher than those of patients with full-thickness tears (P = 0.024) and massive tears (P <0.001). Patients with articular-side, bursal-side, and full-thickness tears had significantly higher CAL thickness averages than patients with massive tears. CONCLUSION: This study showed that the CAL thickness decreases on MRI as arthroscopic CAL degeneration increases. High-grade CAL degeneration and therefore subacromial impingement syndrome can be predicted by looking at the CAL thickness in MRI, which is a non-invasive method.

Distribution and analysis of subacromial spurs and the relationship with acromial classification and angle in healthy individuals.

BACKGROUND: Subacromial spurs are considered the one of the pathology underlying shoulder impingement syndrome. Furthermore, few studies have focused on the morphology of the subacromial spurs in normal Chinese people. This study aimed to study the spur distribution and to illustrate the morphology of spurs, which may help guide the extent of acromioplasty. METHODS: A total of 93 normal individuals were enrolled, and both shoulders of all enrolled individuals were analyzed. The subjects were divided and classified into three different groups by ages: group I = 18-40 years, group II = 41-60 years, and group III ≥ 61 years. The osteophyte distribution, osteophyte area, subacromial surface area and osteophyte area/subacromial surface area ratio were measured and illustrated using Mimics and 3-matic software. The shape of the acromion was classified according to the Bigliani and Morrison classification system. The acromial angle was also classified. Then, the relationship between osteophytes, acromial classification and acromial angle was analyzed. RESULTS: Type II (curved shape) was the most common type of acromion, and the hooked shape was a rare form. A significant increase in the left subacromial surface area in males was observed in group III compared with group I (P < 0.001) and group II (P = 0.004). The total spur/subacromial area ratio was significantly higher in group II than I. An obvious increase in the right subacromial area was observed in group III compared with group I (P = 0.004). Furthermore, there was a significant increase in the right spur area (P = 0.021) and total spur/subacromial area ratio (P = 0.006) in females in group II compared with group I. Fewer spurs were observed on the left than on the right side (p = 0.0482). One spur was most common among type II acromions (29/36) (80.56%) on the left side and the right side (34/52, 65.38%). CONCLUSIONS: Spurs osteophytes are mainly distributed with an irregular shape and mostly run through the medial and lateral sides of the subacromial surface in normal subjects. The characteristics of subacromial spurs are so diverse that a surgeon must conduct subacromial decompression completely based on the morphology of individual spurs.

Novel Posterior Shoulder Stretching With Rapid Eccentric Contraction and Static Stretching in Patients With Subacromial Pain Syndrome: A Randomized Trial.

BACKGROUND: In subacromial pain syndrome (SPS), it is unknown whether posterior shoulder stretching exercises (PSSE) with rapid eccentric contraction, a muscle energy technique, improve clinical and ultrasonographic outcomes more than no stretching or static PSSE. HYPOTHESIS: PSSE with rapid eccentric contraction is superior to no stretching and static PSSE in improving clinical and ultrasonographic outcomes in SPS. STUDY DESIGN: Randomized controlled trial. LEVEL OF EVIDENCE: Level 1. METHODS: Seventy patients with SPS and glenohumeral internal rotation deficit were randomized into the modified cross-body stretching with rapid eccentric contraction group (EMCBS; n = 24), static MCBS group (SMCBS; n = 23), or control group (CG; n = 23). In addition to 4-week physical therapy, EMCBS received PSSE with rapid eccentric contraction, SMCBS static PSSE, and CG no PSSE. The primary outcome was internal rotation range of motion (ROM). Secondary outcomes were posterior shoulder tightness, external rotation ROM (ERROM), pain, modified Constant-Murley score, short form of the disabilities of the arm, shoulder, and hand questionnaire (QuickDASH), rotator cuff strength, acromiohumeral distance (AHD), supraspinatus tendon thickness, and supraspinatus tendon occupation ratio (STOR). RESULTS: Shoulder mobility, pain, function and disability, strength, AHD, and STOR improved in all groups (P < 0.05). CONCLUSION: In patients with SPS, PSSE with rapid eccentric contraction and static PSSE were superior to no stretching in improving clinical and ultrasonographic outcomes. Stretching with rapid eccentric contraction was not superior to static stretching, but improved ERROM compared with no stretching. CLINICAL RELEVANCE: In SPS, both PSSE with rapid eccentric contraction and static PSSE included in physical therapy program are beneficial to improve posterior shoulder mobility and other clinical and ultrasonographic outcomes. In the case of ERROM deficiency, rapid eccentric contraction might be preferred.

Diagnostic Implications of Ultrasound Evaluation in Patients With Shoulder Impingement Syndrome.

OBJECTIVE: To evaluate the diagnostic value of musculoskeletal ultrasound measurements of subacromial bursa (SAB) thickness, supraspinatus tendon (SUP) thickness, acromiohumeral distance (AHD), and SUP-to-AHD ratio (AHD%) in patients with shoulder impingement syndrome (SIS). METHODS: This was a prospective cross-sectional observational study. Thirty patients with SIS (60 shoulders) admitted between January 2019 and January 2020 were enrolled. The SUP thickness, SAB thickness, AHD, and AHD% (calculated as AHD% = [(SUP / AHD) × 100%]) were measured in 60 shoulders using musculoskeletal ultrasound. RESULTS: The affected shoulder displayed thicker SUP and SAB (t = 7.838), narrower AHD (t = 2.324), and larger AHD% (t = 6.875) than the unaffected shoulder (P < .05). The SUP thickness showed a linear positive correlation with AHD (r = .503) and AHD% (r = .792) in the affected shoulder (P < .05). On receiver operating characteristic analysis, AHD*AHD% showed the best diagnostic performance in both measurements (area under the curve: 0.877). CONCLUSION: This study revealed that SIS symptoms may be related to a larger AHD% with SUP thickening. As diagnostic criteria, the cut-off values of AHD% (65.6%) and AHD*AHD% (0.504) have good sensitivity and specificity and can help improve the differential diagnosis of patients with SIS.

The role of bone morphology of the greater tuberosity and lateral acromion on subacromial space during scaption: a three-dimensional dynamic simulation analysis.

BACKGROUND: The bone morphology of the greater tuberosity and lateral acromion plays a central role in subacromial impingement syndrome. The critical shoulder angle (CSA) and greater tuberosity angle (GTA) are two-dimensional measurement parameters that have been validated to evaluate it radiologically. These markers are, however, static and don't consider the dynamic effect of glenohumeral motion. OBJECTIVES: This study aimed to better understand the biomechanics in subacromial impingement with a dynamic simulation based on a validated 3D biomechanical model coupling joint kinematics and 3D reconstructed computed tomography. STUDY DESIGN & METHODS: Sixty-one patients were included in this study: a case group of 44 patients with degenerative rotator cuff tears involving only the supraspinatus, and a control group of 17 without a rotator cuff tear. Patients with previous surgeries, traumatic cuff tears, and cuff tear arthropathy were excluded. CSA, GTA, and impingement-free range of motion (IF-ROM) of the glenohumeral joint in scaption were calculated. Correlation tests were used to determine the relationship between ROM and CSA, GTA, and combined CSA and GTA values. RESULTS: CSA and GTA were significantly higher in the rotator cuff tear group (p = 0.001 and < 0.001), while IF-ROM was significantly higher in the control group (p = 0.001). There was no overall correlation between CSA and GTA (R = 0.02, p = 0.8). Individual correlation between both angles with IF-ROM was negatively weak for CSA (R = -0.4, p < 0.001) and negatively moderate for GTA and IF-ROM (R = -0.5, p < 0.001). However, combining both angles resulted in a negatively high correlation with IF-ROM (R = -0.7, p < 0.001). CONCLUSION: Subacromial space narrowing during scaption is highly correlated to the cumulative values of GTA and CSA. These findings suggest that the combined bony morphology of the lateral acromion and greater tuberosity plays an important role in subacromial impingement. LEVEL OF EVIDENCE: III.

[Subacromial shoulder impingement]. / Subakromiales Schulterimpingement.

Impingement, especially subacromial impingement, is one of the most frequent causes of shoulder pain. It results in soft tissue pathologies due to constriction of the subacromial space. It can lead to tendon pathologies and bursitis. In addition to the clinical examination, imaging methods such as magnetic resonance imaging (MRI), MRI arthrography, ultrasound and X­ray examinations are helpful in making a diagnosis or evaluating the cause of pain. Conservative treatment approaches, such as rest, medication, physiotherapy, manual therapy and infiltrations should primarily be used. If the symptoms do not improve after 3-6 months of conservative treatment, surgical treatment should be considered.

Shoulder Impingement Syndrome.

Shoulder impingement is the most common diagnosis for shoulder pain. Shoulder impingement syndrome has been scrutinized as a misleading "umbrella" term, due to its vague and nonspecific context. It is better subcategorized into subacromial, internal, and subcoracoid impingement. The evaluation and treatment algorithm for each is grossly similar. A thorough history, focused physical examination, and standard radiographs are the first steps. Advanced imaging with MRI or ultrasound may be useful. The mainstay of treatment includes physical therapy, anti-inflammatory medications, and injections. Surgical treatment is reserved for refractory cases, and includes decompression, debridement, and/or repair of injured structures.

Is it the subcoracoid impingement or the subacromial impingement that tears the subscapularis tendon? A comparison of the MRI findings of the operated and healthy shoulders of the patients.

BACKGROUND: : The purpose of this study is to investigate whether the etiological factors accepted as causes of idiopathic subscapularis tears are true or not when the comparison is made with the opposite side healthy shoulder of the patients who underwent arthroscopic repair for an isolated subscapularis tear. METHODS: Sixteen patients who underwent shoulder arthroscopy between February 2016 and January 2018 and were diagnosed with isolated subscapularis tear were evaluated. The coracohumeral distance (CHDax), coracoid overlap (CO), and tuberculum minus cysts (TMC) were evaluated on the axial images of the MRI studies while the acromiohumeral distance (AHDsag), CHDsag, and subscapularis tendon slip number (STSN) on the sagittal oblique images and the AHDcor and SLAP lesion on the coronal oblique images. Degeneration of the coracoacromial ligament was evaluated during arthroscopy. RESULTS: The mean CHDsag (11.26-10.08), CHDax (10.63-9.98), CO (14.2-15.43), AHDsag (8-7.66), and AHDcor (7.65-7.68) measurements (operated side-healthy side, respectively) were statistically similar (p > 0.05). No statistically significant difference was found between TMC and STSN in healthy and operated shoulders (p > 0.05). There was mild coracoacromial ligament fraying in 4 (25%) and obvious coracoacromial ligament fraying in 8 (50%) which indicated subacromial impingement in 75% of the patients. DISCUSSION: The parameters of the coracoid process did not reveal any significant difference between the operated (for an isolated subscapularis tear) and opposite-side healthy shoulders of the patients. However, coracoacromial ligament degeneration was present in 75% of the patients.

Effectiveness of lyophilized growth factors injection for subacromial impingement syndrome: a prospective randomized double-blind placebo-controlled study.

BACKGROUND: Platelet-derived lyophilized growth factors (L-GFs) use a standardized number of allogenic pathogen-free platelets instead of autologous platelets used in PRP as a source of growth factors. This study aimed to evaluate the efficacy of L-GF injection versus placebo in subacromial impingement (SIS) treatment. METHODS: The current randomized double-blind placebo-controlled study included sixty patients (40 females and 20 males, aged between 24 and 75 years) diagnosed with SIS (both clinically and sonographically). Patients were randomly assigned to two equal groups. Under ultrasound guidance, group 1 received subacromial saline injection, and group 2 received L-GF injection. Clinical examination, pain visual analogue scale (VAS), shoulder pain and disability index (SPADI) and shoulder ultrasound were performed before and at the 8th week after injection. RESULTS: Follow-up assessment showed statistically significant improvement in the L-GF group regarding active flexion, active and passive internal rotation and extension, SPADI-disability scale, VAS and thickness of the supraspinatus tendon by US. Regression analysis showed that group 1 was approximately 30 times more likely than the L-GF group to experience painful arc at follow-up. Both groups showed statistically significant improvement in SPADI-pain scale and SPADI-total, flexion and abduction (still the mean value of abduction was significantly higher in the L-GF group). CONCLUSIONS: L-GF injection resulted in clinically significant reductions in pain and functional disability outcomes in patients with SIS. An objective significant reduction in the thickness of the supraspinatus tendon, measured by ultrasound, in the L-GF group hopefully encourages proper healing and functioning in SIS. TRIAL REGISTRATION: The identification number is NCT04330027, date of first registration (01/04/2020). Unique on 21/11/2019, Protocol ID: 0106178.

Alteration in coracohumeral ligament and distance in people with symptoms of subcoracoid impingement.

BACKGROUND: Differentiation between subacromial impingement versus subcoracoid impingement are important for the treatment target. We evaluated the correlations between coracohumeral ligament (CHL) thickness and distance (CHD) and characterized the CHL and subscapularis (SSC) in subcoracoid impingement subjects. METHODS: An observational, cross-sectional study was carried out. Twenty subcoracoid impingement subjects and age/gender matched controls were assessed in 4 different shoulder positions by ultrasonography. RESULTS: Moderate correlations between CHL thickness with CHD (r = 0.455 in neutral rotation, p = 0.044; r = 0.483 in interior rotation, p = 0.031) were found in subacromial subjects. Subcoracoid impingement subjects had greater CHL thickness (difference = 0.3 mm, effect size = 0.85, p = 0.006), SSC tendon thickness (difference = 0.7 mm, effect size = 0.92, p = 0.01) and SSC/CHD occupation ratio (difference = 8%, effect size = 0.95, p = 0.005) compared with the control. CONCLUSIONS: Coracohumeral distance is related to ligament thickness, especially in subacromial impingement subjects. Increased coracohumeral ligament and subscapularis thickness as well as decreased subscapularis/coracohumeral distance occupation ratio are characterized in subcoracoid impingement subjects. These quantitative measurements can be useful in identifying patients at risk of subcoracoid impingement from subacromial impingement.

Subacromial impingement syndrome: association of multiple magnetic resonance imaging parameters with shoulder function and pain.

INTRODUCTION: Shoulder pain is one of the most common complaints in orthopaedics. This study focusses on the relationship between shoulder function in subacromial impingement syndrome and imaging criteria in magnetic resonance imaging (MRI). MATERIALS AND METHODS: This prospective clinical trial included 69 patients treated for subacromial impingement syndrome. Shoulder function (Constant Score, range of abduction, abduction force) and pain were correlated with the following MRI parameters: tendinosis of the rotator cuff, "halo-sign" around the biceps tendon, subacromial distance, critical shoulder angle, size of subacromial osteophytic spurs and maximum width of subacromial and subdeltoid bursa. Statistical analyses included Pearson's and Spearman's coefficients of correlation, multiple regression analysis and Student's t-test. RESULTS: The Constant Score was correlated positively with the critical shoulder angle (r = 0.313; p = 0.009) and inversely with a "halo-sign" around the biceps tendon (rho = -0.384; p = 0.001). There was no significant correlation between spur size and shoulder function, but the size of the subacromial and subdeltoid bursae was positively correlated with the subacromial spur's size (subacromial bursa: coronal plane: r = 0.327; p = 0.006; sagittal view: r = 0.305; p = 0.011; subdeltoid bursa coronal view: r = 0.333 p = 0.005). The width of the subdeltoid bursa in coronal plane was positively correlated with shoulder pain (r = 0.248; p = 0.004) and negatively with the range of abduction (r = -0.270; p = 0.025), as well as the mean (r = -0.332; p = 0.005) and maximum (r = -0.334; p = 0.005) abduction force. CONCLUSIONS: Shoulder function and pain in subacromial impingement are best predicted by the width of the subdeltoid bursa measured in the coronal MRI plane as an indicator of bursitis as well as the presence of a "halo-sign" around the biceps tendon indicating glenohumeral joint effusion. Presence of a subacromial spur could lead to subacromial and subdeltoid bursitis, which impairs shoulder function. Shoulder function seems not to be compromised by the presence of a subacromial spur in absence of bursitis. This study was registered at the German Clinical Trials Register on 08 February 2013 (ID: DRKS00011548).

The Correlation between Various Shoulder Anatomical Indices on X-Ray and Subacromial Impingement and Morphology of Rotator Cuff Tears.

OBJECTIVES: Rotator cuff injury caused by subacromial impingement presents different morphologies. This study aims to investigate the correlation between various shoulder anatomical indexes on X-ray with subacromial impingement and morphology of rotator cuff tears to facilitate surgical management. METHOD: This retrospective study was carried out between January 2020 and May 2022. Patients who were diagnosed as sub-acromial impingement associated with rotator cuff tears (without tendon retraction) and received arthroscopic surgery were enrolled in this study. The radiographic indexes of acromial slope (AS), acromial tilt (AT), lateral acromial angle (LAA), acromial Index (AI), and sub-acromial distance (SAD) were measured on preoperative true AP view and outlet view. The location of rotator cuff tear (anterior, middle, posterior, medial, and lateral) and morphology of tear (horizontal, longitudinal, L-shaped, and irregular shaped) were evaluated by arthroscopy. Groups were set up due to different tear location and tear morphologies, by comparing the various radiographic indices between each group (one-way analysis of variance and t-test), the correlation between radiographic indices and tear characteristics was investigated. RESULTS: We analyzed 92 shoulders from 92 patients with a mean age of 57.23 ± 8.45 years. The AS in anterior tear group (29.32 ± 6.91°) was significantly larger than that in middle tear group (18.41 ± 6.13°) (p = 0.000) and posterior tear group (24.01 ± 7.69°) (p = 0.041). The AS in posterior tear group (24.01 ± 7.69°) was significantly larger than that in middle tear group (18.41 ± 6.13°) (p = 0.029). The LAA in middle tear group (67.41 ± 6.54°) was significantly smaller than that in posterior group (72.74 ± 8.78°) (p = 0.046). The AS in longitudinal tear group (26.86 ± 8.41°) was significantly larger than that in horizontal tear group (22.05 ± 9.47°) (p = 0.035) and L-shaped group (21.56 ± 6.62°) (p = 0.032). The LAA in horizontal group (70.60 ± 6.50°) was significantly larger than that in L-shaped group (66.39 ± 7.31°) (p = 0.033). The AI in L-shaped tear group (0.832 ± 0.074) was significantly larger than that in horizontal tear group (0.780 ± 0.084) (p = 0.019) and irregular tear group (0.781 ± 0.068) (p = 0.047). CONCLUSION: Acromion with a larger AS and a smaller LAA tend to cause anterior or posterior rotator cuff tears rather than middle tears in sub-acromial impingement. Meanwhile acromion with a larger AS tends to cause a longitudinal tear, a larger LAA tends to cause horizontal tears and a larger AI tends to cause L-shaped tears.

Update on Diagnostic Imaging of the Rotator Cuff.

Understanding the anatomy, injury patterns, and surgical procedures is essential for image interpretation. While direct evaluation of the rotator cuff cannot be made, radiographs of the shoulder provide the initial evaluation of the osseous abnormalities associated with rotator cuff impingement. MR imaging is considered the study of choice for the evaluation of the shoulder because of the comprehensive assessment of both bone and soft-tissue abnormalities. MR can accurately evaluate the size and shape of tendon tears, tendon tear retraction, and tendon and muscle quality. Computed tomography is an excellent modality for the evaluation of osseous detail and detection of gas and calcium deposition; however, conventional CT is much less sensitive for bone marrow edema detection and soft tissue detail of the rotator cuff. Ultrasound can assess the rotator cuff with results similar to MRI, but cannot evaluate osseous structures.

Subacromial Motion Metrics in Painful Shoulder Impingement: A Dynamic Quantitative Ultrasonography Analysis.

OBJECTIVES: To explore the subacromial motion metrics in patients with and without subacromial impingement syndrome (SIS) and to investigate whether the abnormality was associated with rotator cuff pathologies. DESIGN: This cross-sectional observational study used dynamic quantitative ultrasonography imaging for shoulder joint assessment. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Individuals with SIS on at least 1 shoulder (n=32) and asymptomatic controls (n=32) (N=64). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Frame-by-frame, the humeral greater tuberosity against the lateral edge of the acromion was traced to obtain the minimal vertical acromiohumeral distance (AHD). The rotation angle and radius of the humerus were computed using the least-squares curve fitting method. RESULTS: Approximately two-thirds of the shoulders with SIS did not have any sonographically identifiable rotator cuff pathologies. There was a consistent trend of nonsignificantly increased humeral rotation angles in painful shoulders. The generalized estimating equation demonstrated that the decreased minimal vertical AHD was associated with painful subacromial impingement (ß coefficient: -0.123cm, 95% confidence interval [CI], -0.199 to -0.047). The area under the curve for the minimal vertical AHD to discriminate painful or impinged shoulders ranged from 0.624-0.676. The increased rotation angle (ß coefficient: 10.516°; 95% CI, 3.103-17.929) and decreased rotation radius (ß coefficient: -2.903cm; 95% CI, -5.693 to -0.111) were shown to be significantly related to the presence of supraspinatus tendinopathy. CONCLUSIONS: Shoulders with SIS were characterized by a decreased minimal vertical AHD during dynamic examination. Abnormal subacromial metrics can develop in patients with mild (or no) rotator cuff pathologies. More prospective cohort studies are warranted to investigate the changes in subacromial motion metrics in populations at risk for painful or impinged shoulders.

[Clinical application of acromion radiological classification in diagnosis and treatment of rotator cuff injury].

OBJECTIVE: To develop a new classification of acromion based on the subacromial impingement theory and the Rockwood tilt view. And explore the application value of the new classification in the diagnosis and treatment of rotator cuff tear. METHODS: The clinical data of 101 patients underwent shoulder arthroscopic surgery for impingement syndrome or rotator cuff tear from January to December 2017 were retrospectively analyzed. There were 34 males and 67 females, aged from 34 to 76 years with an average of (56.31±9.63) years old, course of disease from 2 to 12 months with average of 6 months. Preoperative radiographs of the routine anteroposterior view, Rockwood tilt view and the supraspinatus outlet view were obtained. Based on the subacromial impingement theory and Rockwood radiographs, the morphology of the acromion can be divided into three types:typeⅠ(flat type), typeⅡ(bump type), and type Ⅲ (impingement type). Two observers classified 101 shoulder Rockwood radiographs according to the new classification method and the supraspinatus Outlet radiographs according to the traditional acromial morphological classification method. Supraspinatus tendon injuries were classified into no tear, partial-thickness tear, and full-thickness tear according to the arthroscopic findings. Concordance test (Kappa value) between the inter-observer and intra-observer was carried out for the new classification method and the traditional classification method respectively. The rank sum test was used to compare the mean acromiohumeral distance(AHD) of the three acromion forms in the new acromion classification method. Spearman rank correlation test and Gamma method were used to analyze the correlation between the new acromion classification method and the degree of supraspinatus tendon tear. RESULTS: The inter-observer consistency analysis of the new classification system was significantly better than that of the traditional classification (0.827 vs 0.278), the intra-observer consistency analysis of the new classification system were also significantly better than that of the traditional classification (0.921 vs 0.448, 0.890 vs 0.539). There was no statistical significance in the AHD among three types of the new classification(H=2.186, P>0.05). In all 101 patients, the highest proportion of impingement type acromion was 45.5% (46 cases), followed by bump type acromion was 36.6% (37 cases), and flat type acromion was 17.8% (18 cases). The incidence of supraspinatus tendon tear in the patients with impingement type acromion was significantly higher than that of the other two types of acromion, there was a spearman rank correlation between the new acromion type and the degree of the supraspinatus tendon tear(rs=0.719, P<0.001). CONCLUSION: Rockwood radiographs of the shoulder can well display the anterolateral osteophytes of the acromion. The new acromion classification method based on Rockwood radiographs has high reliability and good reproducibility, in which impingement type of acromion is closely related to supraspinatus tendon tear. Compared with the traditional classification and AHD, the new classification method has more diagnostic value than for rotator cuff injury.

Posteroinferior relevant scapular neck offset in reverse shoulder arthroplasty: key player for motion and friction-type impingement in a computer model.

BACKGROUND: Range of motion (ROM) and prevention of notching remain a challenge for reverse shoulder arthroplasty (RSA). Both may be affected by the morphology of the scapula. The purpose of this study was to define anteroinferior (a) and posteroinferior (p) relevant scapular neck offset (RSNO) and to examine the hypothesis that pRSNO is significantly smaller than aRSNO, and influences rigid body motion (RBM). Adapting glenosphere implantation strategies may therefore be of value. MATERIAL AND METHODS: In this computer model study, we used deidentified computed tomographic scans of 22 patients (11 male and 11 female; mean age: 72.9 years) with massive cuff tears without joint space narrowing. Eight RSA glenoid configurations were tested with a constant neck-shaft angle (145°). Two baseplate types (25 mm; 25 + 3 mm lateralized) and 4 glenospheres (GS) (36 mm; 36 +2 mm of eccentricity; 39 mm; 39 + 3 mm) were used. RSNO was defined as the standardized measurement of the horizontal distance from the inferior extent of the GS to the bony margin of the scapula after baseplate positioning (flush to inferior glenoid extent; neutral position: 0° inclination and 0° version-both software computed). RESULTS: There was a highly significant difference between pRSNO and aRSNO for both genders (P < .001). pRSNO was always smaller than aRSNO. pRSNO was strongly correlated with external rotation (ERO: 0.84) and extension (EXT: 0.74) and moderately correlated with global ROM (GROM: 0.68). There was a moderately strong correlation between aRSNO and internal rotation (IRO: 0.69). pRSNO was strongly correlated with aRSNO, EXT, ERO, IRO, adduction (ADD) and GROM (0.82, 0.72, 0,8, 0.71, 0.82, 0.76) in female patients and with EXT and ERO (0.82, 0.89) in male patients. The median pRSNO allowing for at least 45° ERO and 40° EXT was 14.2 mm for men and 13.8 mm for women. For all patients and models, pRSNO ≥14 mm increased EXT, ERO, and GROM significantly compared with pRSNO <14 mm (P < .001). The combination of lateralization and inferior overhang (eccentricity) led to the most significant increase of pRSNO for each GS size (P < .001). CONCLUSION: This is one of the first RSA modeling studies evaluating nonarthritic glenoids of both genders. The lateral scapular extent to glenoid relationship is asymmetric. pRSNO is always smaller than aRSNO for both genders and was a critical variable for EXT and ERO, demonstrating additional strong correlation with aRSNO, IRO, ADD, and GROM in female patients. pRSNO ≥14 mm was a safe value to prevent friction-type impingement. Combining increased glenosphere size, lateralization, and inferior overhang gives the best results in this computer-simulated setting.

Identification of Diagnostic Magnetic Resonance Imaging Findings in 47 Shoulders with Subcoracoid Impingement Syndrome by Comparison with 100 Normal Shoulders.

BACKGROUND The aim of this study was to identify the diagnostic magnetic resonance imaging (MRI) findings in 47 shoulders with subcoracoid impingement syndrome by comparison with 100 normal shoulders. MATERIAL AND METHODS The subcoracoid impingement syndrome group consisted of 47 shoulders with subcoracoid impingement syndrome and the normal group consisted of 100 normal shoulders. The MRI parameters - coracoids-humeral distance (CHD), coracoid index (CI), height of the lesser tuberosity (HLT), coracoid obliquity (CO), coracoglenoid angle (CGA), coracohumeral angle (CHA), width of the subscapular tendon (WST), and contact distance between subscapular tendon and coracoid process (CD) - were compared between the subcoracoid impingement syndrome group and the normal group. The areas under the curves (AUCs) from the receiver operating characteristic (ROC) for single MRI parameters were recorded, in which the MRI parameters with AUC exceeding 0.70 were included in the analysis of combined parameters. Comparisons of ROC were made among single parameters and combined parameters. RESULTS For diagnosing subcoracoid impingement syndrome by using single MRI parameters (CHD, CI, HLT, CGA, CHA, WST, and CD), the AUCs were 0.963, 0.806, 0.745, 0.691, 0.613, 0.685, and 0.614, respectively, of which CHD had the largest AUC. CHD, CI, and HLT (AUC exceeding 0.70) were included in the study of the combined parameters. The AUC of combined CHD and HLT showed a significantly larger AUC than that of CHD (0.986 vs 0.963, P=0.036), and showed no significant difference compared with that of combined CHD, CI, and HLT (0.986 vs 0.987, P=0.882). CONCLUSIONS Measurement of the coracoid-humeral distance and height of the lesser tuberosity were key MRI diagnostic findings for subcoracoid impingement syndrome.

Supraspinatus tendon thickness and subacromial impingement characteristics in younger and older adults.

BACKGROUND: Subacromial impingement (SAI) may be a cause of age-related rotator cuff abnormalities; therefore, the purpose of this study was to compare SAI characteristics between younger and older adults. In addition to the fact that thickened supraspinatus tendon (SST) indicates tendon abnormalities, SAI characteristics have been recognized as follows: greater SST thickness, reduced acromiohumeral distance (AHD), greater reduction of AHD (∆AHD) with arm elevation, and a higher percentage of SST within AHD (i.e., occupation ratio: OcAHD). Furthermore, we investigated the relationships between SST thickness and AHD, as well as SST thickness and ∆AHD to clarify the effect of SAI on rotator cuff abnormalities. METHODS: Healthy younger (n = 18, 21-24-year-old) and older (n = 27, 45-80-year-old) adults without any shoulder symptoms participated in this study. We measured their SST thickness and AHD at rest and at arm elevation (30° and 60°) in the scapular plane using ultrasound, and calculated ∆AHD as the relative change expressed as a percentage of the baseline. OcAHD was expressed as the ratio of SST thickness at rest to AHD at rest and in elevated positions. RESULTS: The older subjects had approximately one mm thicker SST (P = 0.003, 95% Confidence interval [CI] = 0.410 to 1.895) and approximately 1.0 to 1.3 mm greater AHD than the younger subjects (P = 0.011, 95%CI = 0.284 to 2.068 at rest; P = 0.037, 95%CI = 0.082 to 2.609 for 30° of arm elevation; P = 0.032, 95%CI = 0.120 to 2.458 for 60° of arm elevation). However, there were no differences in ΔAHD and OcAHD between the groups. CONCLUSION: This study demonstrated that, compared with the younger subjects, the older subjects showed thicker supraspinatus tendon but no other SAI characteristics including decreases in AHD and increases in OcAHD. Thus, this study suggests that older subjects showed age-related SST abnormalities without SAI, although the magnitude of the differences in SST thickness is notably small and the clinical significance of this difference is unclear.

[CME Sonography 103: Subacromial Pain Syndrome (SAPS) and Subcoracoid Impingement (SCI)]. / CME-Sonografie 103: Subakromiales (SAI) und subkorakoidales Impingement (SCI).

CME Sonography 103: Subacromial Pain Syndrome (SAPS) and Subcoracoid Impingement (SCI) Abstract. Pain in the shoulder can have its origin in different structures of the shoulder joint or in affected periarticular structures. Therefore, it is important to be able to make a specific diagnosis and identify the exact pathology behind it in order to initiate the most appropriate individually precise treatment. In this review, we discuss possible causes of impingement of the shoulder.

Shoulder impingement syndrome in water polo players: muscle shortening manoeuvre controls pain intensity, recovers function and normalizes sonographic parameters.

PURPOSE: To evaluate the effects of muscle shortening manoeuvre (MSM) by sonography (US) in professional water polo players with shoulder impingement syndrome (SIS). METHODS: Twenty-four professional water polo players (mean age: 22.13 ± 3.34) with SIS were assigned to one of 2 different treatment interventions: Group (1) MSM: a series of fast accelerations in the upward direction was applied to the upper limb that's connected to a spring through a metal plate with a ring. The ring was linked to a pulley system that was submitted to forces acting in the opposite direction (added mass). Group (2) Simple traction: the series of fast accelerations were performed without the springs. Pain intensity, Yocum and Hawkins tests for SIS, Neer's impingement sign, range of motion, muscle strength and shoulder US were assessed. The examination was performed before, immediately after and 30 days after each treatment to study the US width of subacromial-subdeltoid bursa (SSB), thickness of supraspinatus (ST), long biceps tendons (LBT); hypoechoic halo of surrounding the long biceps (LBH) and subscapular tendons (STH); width of acromio-clavicular joint capsule (ACJ) and the distance between bone heads (ACD). Impingement sign (IS) was evaluated by dynamic examination. RESULTS: Immediately after treatment with MSM, pain was much reduced (p = 0.002); Yocum and Hawkins tests were decreased (p = 0.008, p = 0.031); Neer's impingement sign was negative; range of motion and muscle strength were increased. US showed that the following parameters were significantly reduced: SSB (p = 0.001), LBT (p = 0.014), LBH (p = 0.014), SSH (p = 0.002), ACJ (p = 0.004), ACD (p = 0.001). IS was no more detected. After 30 days, the improvement of clinical and US findings was maintained. In the control group, after simple traction, no clinical amelioration of US parameters was found immediately after the procedure. CONCLUSION: These data show that MSM could be significantly and rapidly effective against pain and the loss of function due to shoulder impingement in water polo players.