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.

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.

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.

[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.

Volumetric evaluation of the subacromial space in shoulder impingement syndrome.

INTRODUCTION: Shoulder impingement syndrome is evaluated radiologically with two-dimensional measurement parameters. None of these measurement parameters accurately reflect the three-dimensional geometry. The purpose of this study was to evaluate the volumetric status of the subacromial space in patients with shoulder impingement syndrome and to investigate its relationship with two-dimensional parameters. HYPOTHESIS: The primary hypothesis of this study is that subacromial volume is reduced in patients with impingement syndrome. The second hypothesis is that the sagittal plane morphology of the acromion reflects the subacromial volume better than the coronal plane morphology. PATIENTS AND METHODS: This retrospective study consisted of a total of 52 participants: 26 patients with impingement syndrome and 26 controls. Volumetric measurements were performed with using magnetic resonance imaging. The relationship between humerus and acromion was evaluated by acromiohumeral distance. The sagittal plane morphology of the acromion was evaluated with an objective acromial angle, while the coronal plane morphology was evaluated with a lateral acromial angle. The radiological parameters between groups were compared. RESULTS: The mean subacromial volume was significantly smaller in the impingement group compared to the control group (p=0.01). The subacromial volume had a negative correlation with the objective acromial angle (R=-0.46; p=0.01) The mean tendon volume was significantly higher in the impingement group (p<0.001). The mean acromiohumeral distance in the impingement group (6.8mm±1.0mm), was calculated to be significantly lower than the control group (10.1mm±1.5mm) (p<0.001). There was a positive moderate correlation between subacromial volume and acromiohumeral distance (R=0.61; p=0.01). DISCUSSION: This is the first study to demonstrate a reduction in subacromial volume in patients with impingement syndrome. The sagittal plane morphology of the acromion, rather than the coronal plane, appears to be more closely related to the subacromial volume. LEVEL OF EVIDENCE: III; case-control study.

Morphological Characteristics of Acromion and Acromioclavicular Joint in Patients with Shoulder Impingement Syndrome and Related Recommendations: A Three-Dimensional Analysis Based on Multiplanar Reconstruction of Computed Tomography Scans.

To find out which structure is crucial for the formation of shoulder impingement syndrome with the purpose of directing surgical procedures of subacromial decompression and discussing whether it is necessary to manage acromioclavicular joint during operation and how to do it properly. METHODS: This was a retrospective study. Clinical data and preoperative computed tomography (CT) images were collected from patients who were diagnosed with rotator cuff tears between January 2017 and August 2019 (sample size: 46) and those who were diagnosed without rotator cuff tears between March 2018 and August 2019 (sample size: 44) in our institution, respectively. Three-dimensional models of shoulders were established by multiplanar reconstruction of CT scans and measurements were performed on these models. The parameters such as the acromial length and width, the axial tilt, and the distance from acromial margin to glenoid plane were measured in an adjusted axial plane, and the critical shoulder angle and the spatial volume under acromioclavicular joint were measured in an adjusted coronal plane. The demographic characteristics, the acromial morphology and the spatial volume under acromioclavicular joint were compared to find significant differences between the two groups. The association between the axial tilt and the distance from acromial margin to glenoid plane was evaluated by an ordinary least squares linear regression. RESULTS: The patients with rotator cuff tears consisted of 16 males and 30 females, among which 30 right shoulders and 16 left shoulders were included. The patients without rotator cuff tears consisted of 28 males and 16 females, among which 15 right shoulders and 29 left shoulders were involved. Significant differences between the groups were found in the acromial width (3.332 cm vs 3.111 cm), the axial tilt (33.765° vs 23.829°), the critical shoulder angle (32.630° vs 30.363°), the distance from anterior 3 cm of lateral acromial margin (range, 2.476 cm-3.302 cm vs 1.993 cm-3.089 cm), and anterior 0.9 cm of medial acromial margin (range, 0.967 cm-2.369 cm vs 0.668 cm-1.993 cm) to glenoid plane, and the spatial volume under acromioclavicular joint (1.089 cm vs 1.446 cm) in the two groups. No significant differences were found in the age (60.0 years vs 58.3 years) or the acromial length (4.187 cm vs 4.184 cm). Significant association was revealed by linear regression analysis between the axial tilt and the distance from anterior two-thirds of lateral acromial margin to glenoid plane, and similar association was also found in the anterior half of medial margin. CONCLUSION: Anterior two-thirds of lateral acromial margin, anterior half of medial acromial margin, and inferior aspect of acromioclavicular joint are crucial structures and need to be fully decompressed when treating patients with rotator cuff tears.

Tension band suture technique for the fixation of a displaced posterolateral acromion process fracture with subacromial impingement.

An adult old cyclist presented to our hospital and was referred to the orthopaedic department with a left shoulder posterolateral acromion avulsion fracture and subacromial impingement demonstrated on X-ray and CT. This highly unusual fracture pattern was treated by open reduction and internal fixation with cannulated screws and a tension band suture technique. This fracture went onto successful union with full range of motion and good patient-reported outcome measures by the Oxford Shoulder Score at 3 months. Informed consent was taken for the following case report.

The role of 18F-FDG PET/CT in the diagnosis of frozen shoulder.

PURPOSE: Frozen shoulder is characterized by pain and reduced passive movement capability, and the diagnose is made clinically. However, pain is the major symptom in the first stage before stiffness occurs, and the condition can be mistaken for subacromial impingement. This study explored the possibility to use positron emission tomography/computed tomography (PET/CT) with a 18F Flour-Deoxy-Glucose (FDG) tracer in the diagnostic process. METHODS: Eleven patients with frozen shoulder and 9 patients with subacromial impingement received a 18F-FDG PET/CT scan before being treated surgically. During arthroscopy, the diagnoses were confirmed. Images were blindly analyzed visually by two nuclear medicine physicians. Also, semi-quantified analysis applying a set of standard regions was performed, and standard uptake value in both shoulder regions was recorded. RESULTS: Both the visual description of the pictures and the semi-quantified analysis generally showed increased FDG uptake in the affected shoulder regions of patients that had frozen shoulder and no uptake in patients with subacromial impingement. Kappa for interobserver agreement in the visual assessments was 0.74. Sensitivity was 92% and specificity 93% of the visual assessment, 77% and 93%, respectively, of the semi-quantified analyses, and by combining the two types of analyses sensitivity was 100% and specificity was 93% for the distinction between frozen shoulders and subacromial impingement/unaffected shoulders. CONCLUSION: 18F-FDG PET/CT seems to be a valid method to diagnose frozen shoulder. This is clinically relevant in diagnostically challenging cases, for instance in the first phase of frozen shoulder, which can be difficult to distinguish from subacromial impingement. LEVEL OF EVIDENCE: II.

The acromiohumeral distance in the MRI should not be used as a decision criterion to assess subacromial space width in shoulders with an intact rotator cuff.

PURPOSE: The acromiohumeral distance is in practice often evaluated on MRI by radiologists and a reduction diagnosed as subacromial impingement. However, the acromiohumeral distance as indicator for a decentered glenohumeral joint is defined on a true AP radiograph with the patient standing or sitting. The present study therefore evaluated the influence of the patient position by comparing the acromiohumeral distance in both modalities in shoulders with an intact rotator cuff. METHODS: On MRI images and true AP radiographs of patients > 20 and < 80 years with an intact rotator cuff the acromiohumeral distance was measured. The maximum cranio-caudal size of the glenoid was measured as a reference to allow a direct comparison of both modalities. RESULTS: Two-hundred and thirty-four shoulders (mean patients age 45.8 ± 14.3 years) were included. The mean acromiohumeral distance/glenoid size ratio of all shoulders was significantly larger (P < 0.0001) on the MRI with 4.6 ± 1.0 in comparison to 4.1 ± 0.9 in the radiographs indicating a smaller acromiohumeral distance on the MRI. In absolute values, a mean acromiohumeral distance of 9.2 mm ± 1.8 on MRI in comparison to 10.4 mm ± 2.4 on the radiographs was calculated. Herewith, the acromiohumeral distance in the MRI was in the average 1.2 mm ± 2.1 (13%) smaller than the in corresponding radiographs (P < 0.0001). CONCLUSION: The acromiohumeral distance is significantly smaller in the MRI in comparison to AP radiographs in shoulders with an intact rotator cuff and should not be used as a decision criterion on MRI to assess glenohumeral centering or subacromial space width. LEVEL OF EVIDENCE: IV.

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort.

BACKGROUND: Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability. METHODS: Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images. RESULTS: Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm. CONCLUSIONS: This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to date and demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

Effects of Ultrasound-Guided Peritendinous and Intrabursal Corticosteroid Injections on Shoulder Tendon Elasticity: A Post Hoc Analysis of a Randomized Controlled Trial.

OBJECTIVES: The study aimed to investigate whether the shoulder tendons changed their elasticity after ultrasound-guided peritendinous or intrabursal corticosteroid injections. DESIGN: Post hoc secondary analysis of a double-blinded, randomized controlled study with 3 months of follow-up. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Patients with subacromial impingement syndrome (N=60). INTERVENTIONS: Patients with unilateral shoulder pain were randomly assigned to receive standard ultrasound-guided subacromial or dual-target corticosteroid injections. The supraspinatus tendons were exposed to 40 mg triamcinolone acetonide in the formal group, whereas the long head of the biceps brachii tendons (LHBT) and supraspinatus tendons were individually infiltrated by 20 mg triamcinolone acetonide in the latter group. Patients' bilateral shoulders were divided into group 1 (n=30, receiving standard subacromial injections), group 2 (n=30, receiving dual-target injections), and group 3 (n=60, without injections). MAIN OUTCOME MEASURES: Strain ratio of LHBT and supraspinatus tendons using ultrasound elastography. RESULTS: The repeated-measures analysis of variance revealed no intragroup difference of the strain ratio of the LHBT (P=.412 for group 1, P=.936 for group 2, P=.131 for group 3) and supraspinatus tendon (P=.309 for group 1, P=.067 for group 2, P=.860 for group 3) across the 3 time points. Treating group 3 as the reference, the linear mixed model revealed no significant changes in tendon elasticity after either the standard subacromial injection (P=.205 for the LHBT and P=.529 for the supraspinatus tendon) or the dual-target injection (P=.961 for the LHBT and P=.831 for the supraspinatus tendon). CONCLUSIONS: Elasticity of the LHBT and supraspinatus tendons is unlikely to change after a single dose of peritendinous or intrabursal corticosteroid injections. Future studies with a shorter follow-up interval are needed to validate whether corticosteroid injections can cause transient changes of the tendon's elasticity.

Subacromial decompression versus diagnostic arthroscopy for shoulder impingement: a 5-year follow-up of a randomised, placebo surgery controlled clinical trial.

OBJECTIVES: To assess the long-term efficacy of arthroscopic subacromial decompression (ASD) by comparing it with diagnostic arthroscopy (primary comparison), a placebo surgical intervention, and with a non-operative alternative, exercise therapy (secondary comparison). METHODS: We conducted a multicentre, three group, randomised, controlled superiority trial. We included 210 patients aged 35-65 years, who had symptoms consistent with shoulder impingement syndrome for more than 3 months. 175 participants (83%) completed the 5 years follow-up. Patient enrolment began on 1 February 2005 and the 5-year follow-up was completed by 10 October 2018. The two primary outcomes were shoulder pain at rest and on arm activity measured with Visual Analogue Scale (VAS). Minimally important difference (MID) was set at 15. We used a mixed-model repeated measurements analysis of variance with participant as a random factor, the baseline value as a covariate and assuming a covariance structure with compound symmetry. RESULTS: In the primary intention to treat analysis (ASD vs diagnostic arthroscopy), there were no between-group differences that exceeded the MID for the primary outcomes at 5 years: the mean difference between groups (ASD minus diagnostic arthroscopy) in pain VAS were -2.0 (95% CI -8.5 to 4.6; p=0.56) at rest and -8.0 (-17.3 to 1.3; p=0.093) on arm activity. There were no between-group differences in the secondary outcomes or adverse events that exceeded the MID. In our secondary comparison (ASD vs exercise therapy), the mean differences between groups (ASD minus exercise therapy) in pain VAS were 1.0 (-5.6 to 7.6; p=0.77) at rest and -3.9 (-12.8 to 5.1; p=0.40) on arm activity. There were no significant between-group differences for the secondary outcomes or adverse events. CONCLUSIONS: ASD provided no benefit over diagnostic arthroscopy (or exercise therapy) at 5 years for patients with shoulder impingement syndrome.

The acromion-greater tuberosity impingement index: A new radiographic measurement and its association with rotator cuff pathology.

PURPOSE: Several radiographic parameters describe humeral head coverage by the acromion. We describe a new radiographic measurement, the acromion-greater tuberosity impingement index (ATI), and its ability to predict rotator cuff pathology. METHODS: The ATI was measured with magnetic resonance imaging (MRI) and X-ray analysis in 83 patients with rotator cuff pathology and 76 patients with acute rotator cuff tears. The lateral acromial angle (LAA), acromion type, the acromion index (AI) and the critical shoulder angle (CSA) were measured to assess their correlations with the ATI. Receiver operating characteristic (ROC) curves were used to predict degenerative rotator cuff pathology. The change in the ATI after acromion surgery was evaluated in both groups. RESULTS: According to the ROC curves, the ATI is a good predictor of degenerative rotator cuff pathology on both X-ray (cut-off, 0.865) and MRI (cut-off, 0.965). Patients with degenerative rotator cuff pathology had a significantly higher average ATI compared to the trauma group (p = 0.001 for X-ray and MRI). The degenerative group had a significantly lower LAA (p = 0.001) and a higher ratio of type III acromion (p = 0.035) than the trauma group. The ATI on X-ray was negatively related to the LAA and positively related to the AI, the CSA and acromion type (each p < 0.05). The ATI on MRI was negatively related to the LAA and positively related to the AI and acromion type (each p <0.05). More patients in the degenerative group than the trauma group needed acromioplasty or acromion decompression (p < 0.05). The ATI on MRI was significantly lower after acromion surgery compared to before surgery in both groups (p < 0.05). CONCLUSION: The ATI is a good predictor of degenerative supraspinatus tendon tears or subacromial impingement syndrome. The ATI on MRI is more accurate and can precisely guide acromion surgery.

Diminutive Incision Acromioplasty Assisted with Arthroscopy in the Treatment of Chinese Patients with Subacromial Impingement Syndrome / Acromioplastia de Incisión Diminuta Asistida con Artroscopia en el Tratamiento de Pacientes Chinos con Síndrome de Pinzamiento Subacromial

ABSTRACT Background: Many causes can lead to shoulder pain and subacromial impingement syndrome (SIS) is the most frequently recorded disorders. The aim of this study was to evaluate the clinical effects of diminutive incision acromioplasty assisted with arthroscopy for the treatment of Chinese patients with subacromial impingement syndrome. Subject and Methods: Twenty-two patients with 24-painful shoulders subacromial impingement syndrome were enrolled. All painful shoulders were in Grades II (8) and III (16) according to Neer's classification. Detailed physical examination was performed. Conventional radiography and subsequent magnetic resonance imaging (MRI) of the shoulder region of all patients were done. The University of California at Los Angeles Shoulder (UCLA) score system was used for all patients to evaluate their satisfaction after surgery. The preoperative recordings of the UCLA scores were collected and all enrolled cases including 24-painful shoulders were available for follow-up in 1, 3, 6, 12 months after surgery. Results: According to the UCLA scoring system, the symptom of all painful shoulders were improved after one year postoperatively. The average score before surgery from 15.4 points increased to 31.2 points postoperatively, showing a statistical difference (p < 0.05). Conclusions: A diminutive incision acromioplasty assisted with arthroscopy is a reliable approach to treat Chinese patients with subacromial impingement syndrome. All painful shoulders were obviously improved in one year after surgery.

ABSTRACT Antecedentes: Muchas causas pueden provocar dolor de hombro y síndrome de compresión subacromial (SIS) es el trastorno más frecuentemente registrado. El objetivo de este estudio fue evaluar la clínica. Efectos de la acromioplastia con incisión diminuta asistida con artroscopia para el tratamiento de Pacientes chinos con síndrome de pinzamiento subacromial. Sujeto y métodos: Se incluyeron veintidós pacientes con síndrome de afectación subacromial de 24-hombros dolorosos. Todos los hombros dolorosos estaban en Grados II (8) y III (16) de acuerdo con la clasificación de Neer. Se realizó examen físico detallado. Se realizaron radiografías convencionales y, posteriormente, imágenes de resonancia magnética (IRM) de la región del hombro de todos los pacientes. El sistema de puntuación de la Universidad de California en Los Angeles Shoulder (UCLA) se utilizó para que todos los pacientes evaluaran su satisfacción después de la cirugía. Los registros preoperatorios de las puntuaciones de UCLA se recopilaron y todos los casos incluidos, incluidos 24-hombros dolorosos, estaban disponibles para el seguimiento en 1, 3, 6 y 12 meses después de la cirugía. Resultados: De acuerdo con el sistema de puntuación de UCLA, el síntoma de todos los hombros dolorosos mejoró después de un año después de la operación. La puntuación promedio antes de la cirugía de 15.4 puntos aumentó a 31.2 puntos después de la operación, mostrando una diferencia estadística (p < 0.05) Conclusiones: Una acromioplastia de incisión diminuta asistida con artroscopia es un enfoque confiable para tratar a pacientes chinos con síndrome de pinzamiento subacromial. Todas las lesiones dolorosas se mejoraron obviamente en un año después de la cirugía.

Estudio comparativo de la distancia coracohumeral en pacientes con patología degenerativa del subescapular y una población voluntaria asintomática / Comparative analysis of the coracohumeral distance between patients with degenerative subscapularis tendon pathology and a normal age-matched population

INTRODUCCIÓN: El pinzamiento subcoracoideo secundario a una distancia coracohumeral (DCH) disminuida, ha sido descrito como una posible etiología de las lesiones degenerativas del tendón del Subescapular (SSC), sin embargo, esa teoría aún es controversial. OBJETIVO: Evaluar si existe una diferencia significativa entre la DCH promedio de pacientes con patología degenerativa del SSC y un grupo control. MATERIALES Y MÉTODOS: Se diseñó un estudio de casos-controles y se estableció un tamaño muestral mínimo de 36 casos por grupo. De nuestra base de datos, y dentro de un periodo de 6 meses, se rescataron 46 Resonancias Magnéticas (RM) de hombro con patología degenerativa avanzada y/o roturas del SSC (grupo SSC). El grupo control fue conformado por 36 RM realizadas a voluntarios asintomáticos sin patología del mango rotador. Se incluyeron en ambos grupos solo pacientes entre 40 y 60 años. Se utilizó prueba de t para determinar las diferencias entre 2 grupos con un nivel de confianza del 95%. RESULTADOS: La edad promedio del grupo SSC fue 50,1 6,1 años y del grupo control 51,7 6,8 años, no existiendo diferencia estadísticamente significativa entre ambos (p » 0.43). La DCH promedio en el grupo SSC fue 8,58 mm [IC: 7,95­9,21 mm], y en el grupo control fue 11,04 mm [IC: 10,05­12,04 mm]. Al comparar la DCH, se encontró una diferencia estadísticamente significativa entre grupos (p » 0,00048). CONCLUSIÓN: Nuestros resultados respaldan la existencia de una asociación estadísticamente significativa entre una DCH disminuida y la presencia de patología degenerativa del SSC. NIVEL DE EVIDENCIA: III (Estudio de casos y controles).

BACKGROUND: The incidence of subscapularis tears is increasing as diagnostic imaging and arthroscopic technology improves. Decreased coracohumeral distance (CHD) with associated Subcoracoid Impingement is thought to be one, potential etiology for these lesions. OBJECTIVE: The purpose of this study was to identify the association between reduced CHD and degenerative pathology of the subscapularis tendon. METHODS: A comparative case-control study was performed. The sample size required to determine significance was calculated to be 36 cases. In total, 46 patients with severe degenerative SSC tendinopathy or subscapularis tears on magnetic resonance imaging (MR) were collected consecutively from our database (SSC group). The control group consisted of 36 asymptomatic volunteers undergoing shoulder MR. Only patients between 40 and 60 years of age were included. An independent t-test was used to determine the statistical significance between the two groups (with a 95% level of confidence). RESULTS: No statistically relevant difference was found between the average age of the two groups (50.1 6.1 and 51.7 6.8; p » 0.43). In the control group, the mean CHD was found to be 11.04 mm [CI:10.05­12.04 mm] and was 8.58 mm [CI: 7.95­9.21 mm] in the subscapularis group. The statistical analysis, comparing the CHD showed a significant difference between groups (p » 0.00048). CONCLUSION: This study supports the conclusion that degenerative subscapularis pathology is associated with narrowed coracohumeral distance, when compared with an asymptomatic age-matched group. LEVEL OF EVIDENCE: III (case-control study).

A new method for measurement of the size of subacromial spurs of the shoulder by cassette tilt view.

OBJECTIVE: Subacromial impingement syndrome is one of the most common causes of pain in the shoulder. To this date, there is no specific radiographic view that can be used to evaluate the size of a subacromial spur. This study aims to examine a cassette tilt view can be used to evaluate the size of a subacromial spur. METHODS: A cross-sectional study was conducted between the time period of January 1, 2016, and December 31, 2016. Forty-three consecutive patients that had planned treatment of arthroscopic subacromial decompression (SAD) participated in this study. Rockwood view and cassette tilt view (caudal tilt 30  with beam and cassette) X-rays were done in all these patients. The measurements of the spur sizes were calculated from both views and were compared to the spur sizes measured intraoperatively. RESULT: The size of the spurs from intraoperative measurement was not significantly different from the spur size measured using the cassette tilt view with a mean difference of 0.54 (95% confidence interval (CI): - 0.58, 1.65), but the intraoperative measurement was significantly different from the Rockwood view spur measurement, with a mean difference of 2.84 (95% CI: 1.56, 4.11). Average proportions of the size of the spur from the cassette tilt and Rockwood view compared to that from intraoperative measurements were 1.09 and 1.55, respectively. CONCLUSION: The cassette tilt view is a simple method of measurement of the size of subacromial spurs, with good inter- and intra-observer reliabilities and good validity. This can be useful clinically when setting the patient position and portals to evaluate the size of the spur when planning SAD. LEVEL OF EVIDENCE: This is level III.

Attrition of rotator cuff without progression to tears during 2-5 years of conservative treatment for impingement syndrome.

PURPOSE: The purpose of this study was to investigate the natural history of intact rotator cuff in impingement syndrome patients with concomitant spur protruding from the undersurface of acromion. METHODS: This retrospective study included 119 patients with an intact rotator cuff who underwent conservative treatment for a spur protruding from the undersurface of the acromion. The protruded spur was defined as a trapezoid- or tetragon-shaped bony protrusion with a downward peak extending more than 3 mm in length from the baseline drawn along the acromial undersurface on the coronal view of magnetic resonance imaging (MRI) or computed tomography arthrography (CTA). Functional outcomes were evaluated by the visual analogue scale for pain, subjective shoulder value, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and active range of motion (ROM). To evaluate cuff integrity, follow-up MRI, CTA, or ultrasound were performed at least 2 years after the initial presentation. RESULTS: No new rotator cuff tears were noted in any patient during the follow-up imaging studies. However, 18 patients (15%) underwent arthroscopic acromioplasty during the study period. During the arthroscopic examinations, moderate to severe attrition of the cuff was identified, although no tears were seen. At the final follow-up, pain level and shoulder function, including ROM, showed satisfactory outcomes. CONCLUSION: Spurs protruding from the acromial undersurface did not lead to rotator cuff tears during 2-5 years of conservative treatment. However, attrition of the rotator cuff was found during arthroscopic acromioplasty, suggesting that the protruding spurs caused extrinsic impingement of the cuff. LEVEL OF EVIDENCE: Therapeutic case series Level IV.