Implication of bone morphology in degenerative rotator cuff lesions: A prospective comparative study between greater tuberosity angle and critical shoulder angle

The relationship between the shape of rotator cuff tears and shoulder anatomical parameters

BACKGROUND

The aim of this study is to investigate the potential relationship between shoulder anatomical parameters and the shape of rotator cuff tears (L-shaped, U-shaped, and crescent-shaped).

MATERIALS AND METHODS

The study included 160 (n:160) patients. Patients were divided into four groups: crescent type, u type and L type tears and control group. There were 40 cases in each group. The operated patients were divided into three groups based on the shape of the tears in arthroscopic images. Measurements of Critical Shoulder Angle (CSA), Greater Tuberosity Angle (GTA), Acromion Index (AI), Lateral Acromion Angle (LAA), and Humerus Footprint width (coronal width and sagittal width) were taken in each group and compared.

RESULTS

Patients were divided into four different groups: Crescent type group (n:40), L type group (n:40), U type group (n:40) and control group (n:40). Upon assessing the coronal and sagittal width measurements, The mean coranal width measurement of the L-type tear group was 12.62 ± 0.29 mm, which was significantly higher than all other groups (p < 0.05). The mean sagittal width of the L-type tear group was 34.95 ± 0.29 mm, which was significantly higher than all other groups (p < 0.05). When the groups were evaluated based on GTA, CSA, and AI data, the mean GTA measurement of the L-type tear group was 73.03 ± 0.95 degrees, which was significantly higher than all other groups (p < 0.05). The mean CSA measurement of the L-type tear group was 34.77 ± 0.66 degrees, which was significantly higher than all other groups (p < 0.05). The mean AI measurement of the L-type tear group was 0.77 ± 0.02, which was significantly higher than all other groups (p < 0.05). When the groups were evaluated based on LAA data, the mean LAA measurement of the L-type tear group was 76.98 ± 1.04 degrees, which was significantly lower than all other groups (p < 0.05).

CONCLUSION

In our study, especially in L-shaped tears, measurements of GTA, CSA, AI, LAA, coronal and sagittal width were found to be different compared to the control group. These results suggest that shoulder anatomy affects the mechanisms of rotator cuff tear formation and that these parameters play a more significant role in L-shaped tears.

Acromioplasty combined with arthroscopic rotator cuff repair can reduce the risk of reoperation: a systematic review and meta-analysis

BACKGROUND

Whether to perform acromioplasty in arthroscopic rotator cuff repair (ARCR) is controversial, and the optimal surgical approach for rotator cuff tear repair is unknown. The purpose of this study was to compare the reoperation rate, retear rate and patient-reported outcomes (PROs) of ARCR with those of ARCR combined with acromioplasty (ARCR-A).

METHODS

PubMed, Embase and Cochrane Library were searched for relevant literature dated between database inception and 4 December 2023. The primary outcomes of this study were the reoperation rate and the retear rate. The secondary outcomes were PROs, including the visual analogue scale (VAS) pain score, the American Shoulder and Elbow Surgeons (ASES) score, the University of California-Los Angeles (UCLA) score, the Constant score and the Western Ontario Rotator Cuff (WORC) score. The quality of the included studies was evaluated by using the risk of bias assessment tool. RevMan 5.3 software was used for meta-analysis. Fixed (I2 <50%) or random (I2 ≥50%) effects models were applied to calculate the effect size.

RESULTS

Meta-analysis revealed that ARCR-A had a lower reoperation rate (OR = 0.35, 95%CI: 0.15-0.85, p = 0.02), but the difference in the retear rate between ARCR-A and ARCR was not significant (p = 0.25). In type 2 acromion patients, the reoperation rate was not significantly different between ARCR and ARCR-A (p = 0.12), but, for type 3 acromion patients, the retear rate was lower for ARCR-A than for ARCR (OR = 0.12, 95%CI: 0.01-0.94, p = 0.04). There were statistically significant differences in the 6-month postoperative Constant scores (p < 0.001), VAS pain scores (p = 0.003) 12-month postoperative ASES scores (p = 0.02) and 24-month postoperative WORC scores (p = 0.04), but these differences were not clinically significant.

CONCLUSIONS

Combining ARCR with acromioplasty can reduce the rate of reoperation, especially in patients with type 3 acromion, but it provides no clinically important change in the retear rate and postoperative PRO compared with ARCR.

Can the presence of SLAP-5 lesions be predicted by using the critical shoulder angle in traumatic anterior shoulder instability?

OBJECTIVE

Although SLAP-5 lesions are associated with recurrent dislocations, their causes and pathomechanisms have not been fully elucidated. This study aimed to investigate the association between SLAP-5 lesions and scapular morphology in traumatic anterior shoulder instability (ASI). We hypothesized that there may be a relationship between SLAP-5 lesions and scapular morphology in traumatic ASI patients.

MATERIALS AND METHODS

The study included 74 patients with isolated Bankart lesions and 69 with SLAP-5 lesions who underwent arthroscopic labral repair for ASI. Critical shoulder angle (CSA) was measured on the roentgenograms, while glenoid inclination (GI) and glenoid version (GV) were measured on magnetic resonance imaging (MRI) by two observers in two separate sessions blinded to each other. Both groups were compared in terms of CSA, GI, and GV.

RESULTS

The mean ages of Bankart and SLAP-5 patients were 28.4±9.1 and 27.9±7.7 (P=0.89), respectively; their mean CSA values were 33.1°±2.6° and 28.2°±2.4°, respectively (P<0.001). The ROC analysis's cut-off value was 30.5°, with 75.0% sensitivity and 76.7% specificity (AUC = 0.830). SLAP-5 lesions were more common on the dominant side than isolated Bankart lesions (P=0.021), but no difference was found between the groups in terms of GI and GV (P=0.334, P=0.081, respectively).

CONCLUSIONS

In ASI, low CSA values appeared to be related to SLAP-5 lesions, and the cut-off value of CSA for SLAP lesion formation was 30.5° with 75.0% sensitivity and 76.7% specificity. Scapula morphology may be related to the SLAP-5 lesions, and CSA can be used as an additional parameter in provocative diagnostic tests and medical imaging techniques for the detection of SLAP lesions accompanying Bankart lesions.

LEVEL OF EVIDENCE

III retrospective case-control study.

Critical Shoulder Angle in Patients With Cuff Tears

OBJECTIVE

The pathogenesis of rotator cuff tears (RCTs) is multifactorial. Critical shoulder angle (CSA), which represents the lateral extension of the acromion over the cuff, has been proposed as an extrinsic risk factor. The aim of the present systematic review and meta-analysis was to analyze the available literature regarding the correlation between RCT and CSA.

METHODS

A review was carried out in accordance with the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" guidelines on July 17, 2023, using the following databases: PubMed, Ovid, and Cochrane Reviews. The following keywords were used: "critical shoulder angle," "rotator cuff tears," and "rotator cuff lesions." The methodological quality of the studies was assessed with the MINORS SCORE.

RESULTS

Twenty-eight studies were included. The average CSA among the 2110 patients with full-thickness RCT was 36.7 degrees, whereas the same value among the 2972 controls was 33.1 degrees. The average CSA in the 348 patients with partial-thickness RCT was 34.6 degrees, whereas it was 38.1 degrees in the 132 patients with massive RCT. The average MINORS score was 15.6.

CONCLUSIONS

CSA values were significantly higher in patients with RCT compared with the asymptomatic population. In addition, it appears that CSA values increase with the severity of rotator cuff involvement.

Clinical and radiological outcome after arthroscopic rotator cuff repair using PEEK-CF anchors

PURPOSE

The goal of this study was to evaluate the clinical and radiological outcome after arthroscopic rotator cuff repair using new carbonfiber reinforced polyetheretherketone (CF-PEEK) suture anchors.

METHODS

One hundred (n=100) patients with rotator cuff tears were enrolled at seven French hospitals between July 2019 and June 2020. Pain levels, Constant score and Subjective Shoulder Value (SSV) were taken preoperatively and 6months postoperatively. Ultrasonography (US) was performed at 6months postoperatively to evaluate tendon healing using the Sugaya classification. Statistical analysis was done with the Student t-test with 95% confidence intervals.

RESULTS

One hundred patients of the 100 patients were followed at 6months. The mean SSV and Constant score improved from 40.1% preoperatively to 78% at 6months (p<0.0001) and from 43 points preoperatively to 65 points at 6months (p<0.0001), respectively. The mean level of pain, as measured with the visual analogue scale, decreased from 5.9 to 1.6 (p<0.001). There were no postoperative complications that resulted in revision surgery.

CONCLUSION

The study showed good results at 6months follow-up using carbonfiber reinforced PEEK anchors with improved Constant and SSV scores as well as a high ultrasonographic tendon healing rate, making PEEK-CF anchors safe to use, comparable to commonly used anchors.

LEVEL OF EVIDENCE

IV.

The Association between SLAP Lesions and Critical Shoulder Angle and Glenoid Depth

PURPOSE OF THE STUDY

The critical shoulder angle (CSA) is formed by the combination of glenoid inclination and acromial index and has been shown related to rotator cuff tears and glenohumeral osteoarthritis. SLAP lesions today have an important place among bicipitolabral pathologies that cause intensive shoulder pain. We aimed to investigate the relationship between CSA and glenoid depth and SLAP lesions.

MATERIAL AND METHODS

Between March 2017 and January 2022, 279 consecutive shoulder arthroscopy patients' MRI images were retrospectively examined. After the exclusion criteria, 191 patients were eligible. Patients with SLAP lesions (n=37) were assembled as the study group (Group 1), and patients with intact superior labrum (n=154) were named as the control group (Group 2). Critical shoulder angle (CSA) and glenoid depth measurements were performed using the preoperative MRI images.

RESULTS

A total of 191 patients, of whom 84 were male (44%) were included. The mean age was 49.9±14.96 (range 18-79). There was a statistically signifi cant difference between the SLAP group (Group 1) and the control group (Group 2) in terms of CSA (p=0.032). The mean CSA was 31.66°±3.51° in Group 1 and 33.57° ±5.01° in Group 2. The cut-off value for CSA in patients with SLAP lesions was calculated as 32.85° and the area under the curve was 0.61, therefore a satisfactory association was observed between the groups. The mean glenoid depth was 4.32 ±1.25 mm in Group 1, and 4.39 ±0.32 mm in Group 2. There was no statistically signifi cant difference between the groups in terms of glenoid depth (p=0.136) and also no association between the glenoid depth and SLAP lesions was observed (cut-off=4.45 mm, AUC=0.32).

CONCLUSIONS

Low CSA is associated with SLAP lesions, just as in glenohumeral osteoarthritis. Further prospective clinical studies are needed to enlighten the predisposing effect of CSA to SLAP lesions and the success of superior labral repairs.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

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.

Application progress of artificial intelligence and augmented reality in orthopaedic arthroscopy surgery

In today's rapidly developing technological era, the technological revolution triggered by the rapid iteration of artificial intelligence and augmented reality has provided brand-new digital intelligent empowerment for orthopaedic clinical operation. Although traditional arthroscopy has been widely promoted globally due to its advantages such as minimally invasive, safety and early functional exercise, it still has deficiencies in precision and personalization. The assistance of artificial intelligence and augmented reality enables precise positioning and navigation in arthroscopic surgery, as well as personalized operations based on patient conditions, which lifts the objective limitations of traditional sports medicine surgery. The integration of artificial intelligence and augmented reality with orthopaedic arthroscopy surgery is still in infancy, even though there are still some insufficient to be solved, but its prospect is bright.

The Critical Shoulder Angle Can be Accurately and Reliably Determined from Three-Dimensional Computed Tomography Images

OBJECTIVE

Anteroposterior (AP) radiographs do not necessarily offer the optimal approach to measuring the critical shoulder angle (CSA) due to the malposition of the scapula. Three-dimensional computed tomography (3D-CT) may offer some advantages, including the ability to rotate the scapula for position alignment and pre-operative planning for reducing CSA. This study aimed to investigate the accuracy and reliability of CSA measurement in 3D-CT and to determine whether there is an association between CSA and rotator cuff tears (RCTs).

METHODS

In this retrospective study we identified 200 patients who received shoulder arthroscopy from 2019 to 2021, including 142 patients (81 females, 61 males) with RCTs and 58 patients (14 females, 44 males) with non-RCTs. For each participant, CSA was measured from standard shoulder AP radiographs and anterior views of 3D-CT of the scapula by two independent assessors. Inter- and intra-observer agreements were assessed by the intraclass correlation coefficient (ICC). The relationship between the two measurement methodologies was determined by Spearman's correlation coefficient and Bland-Altman plots. Discriminative capacity was calculated by using receiver operating curve (ROC) analyses in the whole cohort and age sub-groups above and below 45 years.

RESULTS

We found perfect inter-observer (ICC >0.96) and intra-observer (ICC >0.97) reliabilities for CSA measurements obtained from the standard AP radiographs and the 3D-CT. There was a strong correlation between the two methods (r = 0.960, P < 0.001). The mean CSA was 31.7° ± 4.2° in the standard AP radiographs and 31.8° ± 4.4° in the 3D-CT (mean difference 0.02°, P = 0.940; bias 0.02°, limits of agreement -2.29° to +2.33°). ROC analysis of the whole cohort showed that the CSA measured in the standard AP radiographs (area under the ROC curve [AUC] = 0.812, P < 0.001) and the 3D-CT (AUC = 0.815, P < 0.001) predicted RCT with high confidence. ROC analysis of patients aged ≥45 years showed that the CSA measured from the standard AP radiographs (AUC = 0.869, P < 0.001) and the 3D-CT (AUC = 0.870, P < 0.001) were very good at predicting RCTs.

CONCLUSION

CSA measured from standard AP radiographs and 3D-CT showed high consistency, and the CSA could be accurately and reliably measured using 3D-CT. CSAs measured from standard AP radiographs and 3D-CT could predict RCTs, especially in patients aged ≥45 years.

The combined utilization of predictors seems more suitable to diagnose and predict rotator cuff tears

BACKGROUND

Morphological markers presenting the lateral extension of acromion and the greater tuberosity of humerus were proposed to diagnose and predict rotator cuff tears (RCTs) in recent years, but few studies have addressed the combined performance when using two predictors together. As a presence of a RCT may be associated with the impingement caused by both acromion and the greater tuberosity, we believe a combined utilization of predictors could result in a better diagnostic and predictive performance than using a single predictor. The aim of this study is to (i) explore whether the combination is more efficient to predict and diagnose RCTs; (ii) find out which combination is the most superior screening approach for RCTs.

METHODS

This was a retrospective study and patients who visited our hospital and were diagnosed with or without partial-thickness or full-thickness RCTs via magnetic resonance imaging from January 2018 to April 2022 were enrolled and classified into two groups respectively. Four predictors, the critical shoulder angle (CSA), the acromion index (AI), the greater tuberosity angle (GTA) and the double-circle radius ratio (DRR) were picked to participate in the present study. Quantitative variables were compared by independent samples t tests and qualitative variables were compared by chi-square tests. Binary logistic regression analysis was used to construct discriminating combined models to further diagnose and predict RCTs. Receiver operating characteristic (ROC) curves were pictured to determine the overall diagnostic performance of the involved predictors and the combined models.

RESULTS

One hundred and thirty-nine shoulders with RCTs and 57 shoulders without RCTs were included. The mean values of CSA (35.36 ± 4.57 versus 31.41 ± 4.09°, P < 0.001), AI (0.69 ± 0.08 versus 0.63 ± 0.08, P < 0.001), DRR (1.43 ± 0.10 versus 1.31 ± 0.08, P < 0.001) and GTA (70.15 ± 7.38 versus 64.75 ± 7.91°, P < 0.001) were significantly higher in the RCT group than for controls. Via ROC curves, we found the combined model always showed a better diagnostic performance than either of its contributors. Via logistic regression analysis, we found the values of both predictors over their cutoff values resulted in an increasement (20.169-161.214 folds) in the risk of having a RCT, which is more than that by using a single predictor only (2.815 -11.191 folds).

CONCLUSION

The combined utilization of predictors is a better approach to diagnose and predict RCTs than using a single predictor, and CSA together with DRR present the strongest detectability for a presence of RCTs.

Computer Image-Guided Precise Acromioplasty for Reducing the Critical Shoulder Angle

The shoulders with critical shoulder angle (CSA) of greater than 33-35° are associated with rotator cuff tears, whereas a CSA of less than 30° is likely to be osteoarthritic. However, anterior acromioplasty or lateral acromioplasty could not reduce high CSAs to the desired range (30-33°), with satisfactory accuracy and efficacy. Thus, we introduce a computer image-guided precise acromioplasty (CIG-PAP) technique, an individualized treatment based on three-dimensional planning. We believe that the introduction of this technique will provide an alternative approach to reduce a large CSA to the desired range (30-33°).