Influence of joint volume on range of motion after arthroscopic rotator cuff repair

BACKGROUND

Capsular contracture is a well-known etiology in the primary stiff shoulder; thus capsular contracture and resultant decreased joint volume could lead to postoperative stiffness, which is a commonly reported morbidity after arthroscopic rotator cuff repair (ARCR). The purpose of this study was (1) to quantify the joint volume (total joint volume and each quadrant compartmental volume) using computed tomography arthrography (CTA) and (2) to demonstrate the relationship between joint volume and postoperative range of motion (ROM) after ARCR.

MATERIALS AND METHODS

Eighty-three patients (60 ± 5.11 years, men = 26, women = 57) who had undergone ARCR between January 2015 to December 2020 due to small to medium full-thickness tear and followed by CTA 6 months postoperatively were retrospectively reviewed. An image reconstruction program (3D Slicer, version 4.11.2 software) was used to calculate the joint volume (total joint volume and quadrant compartment joint volumes; anteroinferior, anterosuperior, posterosuperior and posteroinferior). For shoulder ROM, data including scaption (Sc), external rotation on side (ERs), external rotation at 90° (ER90), and internal rotation on back (IRb) were collected 6 months postoperatively. An evaluation of the correlation between joint volume and each shoulder motion was performed.

RESULTS

There were moderate correlations between the total joint volume and each motion (Sc: Pearson coefficient, 0.32, p = 0.0047; ERs: Pearson coefficient, 0.24, p = 0.0296; ER90: Pearson coefficient, 0.33, p = 0.0023; IRb: Pearson coefficient, 0.23, p = 0.0336). Among the quadrant compartments, the anteroinferior (Sc: Pearson coefficient, 0.26, p = 0.0199; ERs: Pearson coefficient, 0.23, p = 0.0336; ER90: Pearson coefficient, 0.25, p = 0.0246; IRb: Pearson coefficient, 0.26, p = 0.0168) and posterosuperior (Sc: Pearson coefficient, 0.24, p = 0.029; ER90: Pearson coefficient, 0.29, p = 0.008; IRb: Pearson coefficient, 0.22, p = 0.0491) and posteroinferior (Sc: Pearson coefficient, 0.30, p = 0.0064; ER90: Pearson coefficient, 0.29, p = 0.0072) showed moderate correlations with each shoulder motion.

CONCLUSION

Total joint volume, anteroinferior compartment joint volume, posterosuperior compartment joint volume and posteroinferior compartment joint volume were related to postoperative ROM after ARCR. Perioperative methods to increase the joint volume, especially the anteroinferior, posterosuperior and posteroinferior parts of the capsule may prevent postoperative stiffness after ARCR.

LEVEL OF EVIDENCE

Level III; Retrospective Case-Control Study.

Sonographic and elastographic findings after arthroscopic rotator cuff repair: a comparison with clinical results

OBJECTIVE

We assessed the relationship between early postoperative clinical outcomes of arthroscopic rotator cuff repair (ARCR) and observations obtained by postsurgical ultrasound (US) and strain elastography (SE) of repaired supraspinatus tendons (SSTs).

METHODS

This retrospective study included 42 cases in which the patient underwent ARCR followed by postoperative US and SE. The Korean Shoulder Scoring (KSS) system was used to assess preoperative and postoperative conditions. The thickness of the repaired SST and subdeltoid fluid was measured by US. SE scores were classified into four grades (1 to 4) according to elasticity of repaired SST. In addition, SE scores were divided into two groups: soft (SE scores of 1 and 2) and hard (SE scores of 3 and 4). The relationship between clinical outcomes and US parameters and SE scores was determined by KSS.

RESULTS

Postoperative SE scores observed by two readers correlated significantly with function (p = 0.021 and p = 0.021, respectively) and muscle strength (p = 0.008 and p = 0.015, respectively). SE scores were significantly correlated with a difference value of muscle strength of KSS scores (p = 0.002 and p = 0.014). In a comparison of hard and soft groups of repaired SSTs, function (p = 0.008 and p = 0.010, respectively) and muscle strength (p = 0.002 and p = 0.014, respectively) in postoperative KSS scores were statistically higher in the hard SE scores than the soft SE scores. The difference value of function (p = 0.021 and p = 0.021,) and muscle strength (p = 0.008 and p = 0.015) of KSS scores was significantly higher in the hard SE scores.

CONCLUSIONS

Postoperative SE scores of repaired tendons correlated significantly with muscle strength and function after ARCR. Postoperative US images including thickness of repaired tendon and subdeltoid fluid did not correlate with clinical outcome.

ADVANCES IN KNOWLEDGE

SE evaluations of repaired SST may provide important information about postoperative muscle strength and function.

Management of Massive Rotator Cuff Tears Without Arthropathy

Arthroplasty is not an optimal treatment for massive rotator cuff tears in patients who are active and without glenohumeral arthritis. Several surgical techniques have been developed for these patients, including arthroscopic rotator cuff repair with single-/double-row repair (with or without interval slides, margin convergence, graft augmentation), graft bridging, superior capsular reconstruction, tuberoplasty, and tendon transfers. Complete, tension-free, anatomic repair is ideal; however, tendon atrophy and retraction associated with massive tears often complicate repairs. All surgical treatments significantly increase patient-reported functional outcomes 1 year after intervention, with many treatments demonstrating improved mid-term and long-term outcomes. [Orthopedics. 2023;46(1):e1-e12.].

Can subcoracoid effusion be a more specific finding for subscapularis tear among rotator cuff pathologies on magnetic resonance imaging?

HYPOTHESIS AND BACKGROUND

Magnetic resonance imaging (MRI) is a well-known, noninvasive diagnostic method for rotator cuff tendon pathologies that are not very sensitive for subscapularis tendon tears. Subcoracoid effusion (SE) is an easily recognizable radiologic sign on MRI. In this study, we aimed to examine the relationship of SE with rotator cuff tear and to investigate whether SE could be a supportive finding in the diagnosis of subscapularis tear in preoperative MRI. Our hypothesis was that SE was a more specific finding of subscapularis tear than other rotator cuff tears.

METHODS

The data of patients who underwent shoulder arthroscopy in our clinic between 2017 and 2021 were analyzed retrospectively. Four groups were included in the study: patients with a rotator cuff tear accompanied by a subscapularis tear (group 1, n = 273), patients with isolated subscapularis tear (group 2, n = 57), patients with rotator cuff tear with intact subscapularis tendon (group 3, n = 190), and patients without any rotator cuff pathology (group 4, n = 263). Arthroscopic video records and MRIs of all patients were evaluated retrospectively. Subscapularis tendon tears were classified according to the Lafosse classification.

RESULTS

There was a statistically significant difference between the groups in terms of the presence of SE on MRI (P = .001). The presence of SE in group 1 and group 2 was statistically significantly higher than that in both group 3 and group 4 (P = .001), and there was no significant difference between group 3 and group 4 (P > .05). A significant relationship was found between Lafosse classification and SE (P = .001). When the diagnostic powers of the detection of SSC tear and the presence of SE on MRI for SSC tear were compared, Kappa values were 0.615 (P = .001) and 0.701 (P = .001), and overall diagnostic accuracy rates were 80.3% and 85.5%, respectively.

CONCLUSION

We conclude that SE is a more specific finding for subscapularis tears than other rotator cuff pathologies. We suggest that SE on MRI should also be considered in patients with a rotator cuff tear in whom a subscapularis tear was not detected in preoperative MRI and that the subscapularis tendon should be carefully evaluated during surgery in cases where the effusion is positive.

Reliability of Ellman Classification System in Partial Thickness Rotator Cuff Tears on Magnetic Resonance Views

PURPOSE OF THE STUDY The current study aimed to investigate the intra- and inter-observer reliability of the Ellman classification system in partialthickness rotator cuff tears through magnetic resonance imaging (MRI) scans instead of arthroscopic views. MATERIAL AND METHODS Pre-operative MRI scans of 45 patients, with confirmed partial-thickness rotator cuff rupture in previous arthroscopic surgeries (performed by the senior author), were obtained from Picture Archiving and Communication Systems records. The observers (n=8) were asked to categorize MRI scans according to Ellman's classification of location and grade. There were four orthopedic surgeons less experienced in rotator cuff operations in the first group and four more experienced orthopedic surgeons in the second group. They were asked to re-evaluate the MRI scans six weeks later, without access to their previous answers. Reliability evaluation was performed within and among the groups. It was also evaluated if the surgeon's experience increased the reliability of the classification. Fleiss kappa coefficient was used for the inter-observer reliability and Cohen kappa coefficient for the intra-observer reliability, and post hoc analysis was performed. RESULTS When all observers were examined in the inter-observer evaluation, it was seen that there was moderate agreement in the first location evaluation (κ=0.414); however, there was fair agreement in all other evaluations in both groups (κ=0.339- 0.383-0.337, respectively). When all observers were examined in the mean intra-observer evaluation, it was seen that there was substantial agreement in both evaluations (κ=0.795-0.721, respectively). DISCUSSION A classification system must be valid, reliable, and reproducible. It should establish a standard terminology for both surgeons and researchers. The correct identification of the tear configuration is crucial for selecting the correct repair technique. In our study, in which we evaluated the Ellman classification, which is frequently used in arthroscopic diagnosis, we investigated its intra-observer and inter-observer reliability on MRI scans. Although the mean intra-observer evaluation results were substantial agreement (κ=0.795-0.721, respectively), inter-observer evaluation results were fair agreement (κ=0.339- 0.383-0.337, respectively) except for the first location evaluation (κ=0.414). CONCLUSIONS Although intra-observer reliability was satisfactory, the Ellman system used in the classification of partial-thickness rotator cuff tears was not found to be useful by using only MRI views because of fair inter-observer reliability except for the first location evaluation, which was moderate agreement. Key words: partial, rotator cuff, tear, Ellman classification, reliability, validity.

Application of diffusion microstructure imaging in musculoskeletal radiology - translation from head to shoulders

OBJECTIVES

Quantitative MRI techniques, such as diffusion microstructure imaging (DMI), are increasingly applied for advanced tissue characterization. We determined its value in rotator cuff (RC) muscle imaging by studying the association of DMI parameters to isometric strength and fat fraction (FF).

METHODS

Healthy individuals prospectively underwent 3T-MRI of the shoulder using DMI and chemical shift encoding-based water-fat imaging. RC muscles were segmented and quantitative MRI metrics (V-ISO, free fluid; V-intra, compartment inside of muscle fibers; V-extra, compartment outside of muscle fibers, and FF) were extracted. Isometric shoulder strength was quantified using specific clinical tests. Sex-related differences were assessed with Student's t. Association of DMI-metrics, FF, and strength was tested. A factorial two-way ANOVA was performed to compare the main effects of sex and external/internal strength-ratio and their interaction effects on quantitative imaging parameters ratios of infraspinatus/subscapularis.

RESULTS

Among 22 participants (mean age: 26.7 ± 3.1 years, 50% female, mean BMI: 22.6 ± 1.9 kg/m²), FF of the individual RC muscles did not correlate with strength or DMI parameters (all p > 0.05). Subjects with higher V-intra (r = 0.57 to 0.87, p < 0.01) and lower V-ISO (r = -0.6 to -0.88, p < 0.01) had higher internal and external rotation strength. Moreover, V-intra was higher and V-ISO was lower in all RC muscles in males compared to female subjects (all p < 0.01). There was a sex-independent association of external/internal strength-ratio with the ratio of V-extra of infraspinatus/subscapularis (p = 0.02).

CONCLUSIONS

Quantitative DMI parameters may provide incremental information about muscular function and microstructure in young athletes and may serve as a potential biomarker.

KEY POINTS

• Diffusion microstructure imaging was successfully applied to non-invasively assess the microstructure of rotator cuff muscles in healthy volunteers. • Sex-related differences in the microstructural composition of the rotator cuff were observed. • Muscular microstructural metrics correlated with rotator cuff strength and may serve as an imaging biomarker of muscular integrity and function.

Artificial Intelligence in the Management of Rotator Cuff Tears

Technological innovation is a key component of orthopedic surgery. Artificial intelligence (AI), which describes the ability of computers to process massive data and "learn" from it to produce outputs that mirror human cognition and problem solving, may become an important tool for orthopedic surgeons in the future. AI may be able to improve decision making, both clinically and surgically, via integrating additional data-driven problem solving into practice. The aim of this article will be to review the current applications of AI in the management of rotator cuff tears. The article will discuss various stages of the clinical course: predictive models and prognosis, diagnosis, intraoperative applications, and postoperative care and rehabilitation. Throughout the article, which is a review in terms of study design, we will introduce the concept of AI in rotator cuff tears and provide examples of how these tools can impact clinical practice and patient care. Though many advancements in AI have been made regarding evaluating rotator cuff tears-particularly in the realm of diagnostic imaging-further advancements are required before they become a regular facet of daily clinical practice.

Longitudinal MR Quantification of the Fat Fraction within the Supraspinatus and Infraspinatus Muscles in Patients with Shoulder Pain

RATIONALE AND OBJECTIVES

Knowing the natural history of fatty degeneration of rotator cuff muscles is important for estimating the risk and rate of progression to cuff tear arthropathy (CTA). The purpose of this study was to investigate the changes in rotator cuff muscle fatty degeneration over time quantitatively in patients treated conservatively for shoulder pain.

MATERIALS AND METHODS

Thirty patients with a baseline and follow-up shoulder MRI, including a 2-point Dixon sequence, which were performed at least 1 year apart, were included. We classified patients into 3 groups: "full-thickness tear" (n = 7), "partial-thickness tear" (n = 13), and "no-tear" (n = 10) groups. The fat fraction in the supra- and infraspinatus muscles, and the rate of change in the fat fraction (ΔFfr) were calculated using the formula "fat fraction of follow-up MRI/fat fraction of initial MRI." We investigated the difference in ΔFfr among the 3 groups and the degree of progression to CTA.

RESULTS

Statistically significant differences in ΔFfr within the supraspinatus and infraspinatus muscles were found among full-thickness, partial-thickness, and no-tear groups (2.54 vs 1.02 vs 0.75, p < 0.001 and 1.96 vs 1.07 vs 0.73, p = 0.021, respectively). Overall, 71.4% of the full-thickness tear group showed progression of CTA, and 28.6% of the full-thickness tear group needed reverse shoulder arthroplasty within an average follow-up period of 34 months.

CONCLUSIONS

MR quantification, together with the knowledge of change in fatty degeneration over time, may be useful for the management of patients with shoulder pain.

Ultrasonography in the diagnosis of rotator cuff avulsion fracture

Deepening the understanding of morphology and corresponding sonographic features of the greater tuberosity and the various fracture lines in avulsion fracture like the "horizontal line sign" and "double-line sign" and sharp bony prominence besides the defect on the greater tuberosity, can make it simple to identify avulsion fracture accurately and quickly.

Arthroscopic biceps augmentation does not improve clinical outcomes during incomplete repair of large to massive rotator cuff tears

AIMS

This study compared patients who underwent arthroscopic repair of large to massive rotator cuff tears (LMRCTs) with isolated incomplete repair of the tear and patients with incomplete repair with biceps tendon augmentation. We aimed to evaluate the additional benefit on clinical outcomes and the capacity to lower the re-tear rate.

METHODS

We retrospectively reviewed 1,115 patients who underwent arthroscopic rotator cuff repair for full-thickness tears between October 2011 and May 2019. From this series, we identified 77 patients (28 male, 49 female) with a mean age of 64.1 years (50 to 80). Patients were classified into groups A (n = 47 incomplete) and B (n = 30 with biceps augmentation) according to the nature of their reconstruction. Clinical scores were checked preoperatively and at six months, one year, and two years postoperatively. In preoperative MRI, we measured the tear size, the degree of fatty infiltration, and muscle volume ratio of the supraspinatus. In postoperative MRI, the integrity of the repaired rotator cuff tendon was assessed using the Sugaya classification. Tendon thickness at the footprint was evaluated on T2-weighted oblique coronal view.

RESULTS

There were no significant differences in the initial preoperative demographic characteristics. In both groups, there were significant improvements in postoperative clinical scores (p < 0.001). However, most clinical outcomes, including range of motion measurements (forward elevation, external rotation, internal rotation, and abduction), showed no differences between the pre- and postoperative values. Comparing the postoperative outcomes of both groups, no further improvement from biceps augmentation was found. Group B, although not reaching statistical significance, had more re-tears than group A (30% vs 15%; p = 0.117).

CONCLUSION

In LMRCTs, biceps augmentation provided no significant improvement of an incomplete repair. Therefore, biceps augmentation is not recommended in the treatment of LMRCTs.Cite this article: Bone Joint J 2022;104-B(11):1234-1241.

Can deep learning reduce the time and effort required for manual segmentation in 3D reconstruction of MRI in rotator cuff tears?

Background/Purpose

The use of MRI as a diagnostic tool has gained popularity in the field of orthopedics. Although 3-dimensional (3D) MRI offers more intuitive visualization and can better facilitate treatment planning than 2-dimensional (2D) MRI, manual segmentation for 3D visualization is time-consuming and lacks reproducibility. Recent advancements in deep learning may provide a solution to this problem through the process of automatic segmentation. The purpose of this study was to develop automated semantic segmentation on 2D MRI images of rotator cuff tears by using a convolutional neural network to visualize 3D models of related anatomic structures.

Methods

MRI scans from 56 patients with rotator cuff tears (T2 Linear Coronal MRI; 3.0T, 512 mm × 512 mm, and 2.5-mm slice thickness) were collected. Segmentation masks for the cuff tendon, muscle, bone, and cartilage were obtained by four orthopedic shoulder surgeons, and these data were revised by a shoulder surgeon with more than 20 years’ experience. We performed 2D and 3D segmentation using nnU-Net with secondary labels for reducing false positives. Final validation was performed in an external T2 MRI dataset (10 cases) acquired from other institutions. The Dice Similarity Coefficient (DSC) was used to validate segmentation quality.

Results

The use of 3D nnU-Net with secondary labels to reduce false positives achieved satisfactory results, even with a limited amount of data. The DSCs (mean ± SD) of the cuff tendon, muscle, bone, and cartilage in the internal test set were 80.7% ± 9.7%, 85.8% ± 8.6%, 97.8% ± 0.6%, and 80.8% ± 15.1%, respectively. In external validation, the DSC of the tendon segmentation was 82.74±5.2%.

Conclusion

Automated segmentation using 3D U-Net produced acceptable accuracy and reproducibility. This method could provide rapid, intuitive visualization that can significantly facilitate the diagnosis and treatment planning in patients with rotator cuff tears.

[Postoperative imaging of the shoulder]

BACKGROUND

Imaging of the postoperative shoulder joint includes complex, diagnostically challenging changes regarding the anatomical structures.

OBJECTIVES

Case-based presentation of common surgical procedures, expected postoperative findings, and typical complications.

MATERIALS AND METHODS

Interdisciplinary evaluation of (didactically instructive) cases and discussion of pertinent literature and expert opinions.

RESULTS

Presentation of normal postoperative findings and complications after subacromial decompression, surgical treatment of rotator cuff lesions, SLAP (superior labral anterior to posterior) lesions/lesions of the long biceps tendon, Bankart lesions as well as instability-related procedures and after shoulder arthroplasty. Discussion of the appropriate use of imaging methods with a focus on magnetic resonance imaging (MRI), which are supplemented by computed tomography (CT), and conventional x‑ray images.

CONCLUSION

The broad spectrum of complex findings as well as the evermore developing and thereby changing surgical procedures result in significant challenges in the radiological evaluation of the postoperative shoulder joint. To differentiate physiological reactions from pathological changes it is necessary to have general knowledge of the common surgical procedures, expected postoperative findings and possible complications. A variety imaging modalities can be used to further advance diagnostic precision.

Clinical and MRI outcomes of subacromial impingement syndrome with conservative treatment: a 21-month prospective study

BACKGROUND

Information is lacking on the natural history of early stages of degenerative rotator cuff disease. Such information can be obtained by using clinical and imaging assessment after conservative treatment in affected patients.

HYPOTHESIS

Subacromial impingement syndrome is a clinical presentation that can be associated with early stages of the disease. We aimed to describe the natural history of degenerative rotator cuff disease from the early stages by studying clinical and imaging outcomes in non-operated patients with subacromial impingement syndrome.

PATIENTS AND METHODS

Patients with subacromial impingement syndrome were prospectively included. They had conservative treatment and were assessed before treatment and during at least 12-month follow-up. Assessment included clinical evaluation on a 0- to 100-point Constant scale and subscales as well as MRI of the rotator cuff. Clinical results were compared to baseline MRI findings and according to lesional progression.

RESULTS

We included 26 patients with mean age 59.1 (SD 9.6), mean pain duration 23.1 (31.3) months; mean total Constant score 39.1 (12.1). Overall, 9 patients had no tear, 9 had a partial tear and 8 had a full-thickness tear. Mean follow-up was 21 (SD 10) months. Total Constant score and subscores improved at follow-up in the overall sample. Patients without tear and those with partial or full-thickness tear at baseline showed clinical improvement. MRI of the rotator cuff at follow-up indicated lesional worsening in 7 patients. However, clinical improvement did not differ by lesional progression or not.

CONCLUSION

We report on 21-month clinical and MRI assessments of degenerative rotator cuff disorders including early stages of the disease. Clinical improvement was not related to MRI changes over time. Further investigations are needed to verify our findings in larger study populations.

Clinical and radiographic outcomes following reverse total shoulder arthroplasty in patients 60 years of age and younger

BACKGROUND

Although initially indicated for use in older patients, reverse total shoulder arthroplasty (rTSA) is being increasingly used in younger patients. The purpose of this study is to compare the clinical and radiographic outcomes of patients aged <60 years to those aged 60-79 years following primary rTSA.

METHODS

154 patients aged <60 years and 1763 patients aged 60-79 years were identified from an international multi-institutional Western Institutional Review Board-approved registry with a minimum 2 years' follow-up. All patients were evaluated and scored preoperatively and at latest follow-up using 5 outcome scoring metrics and 4 active range of motion (ROM) measurements.

RESULTS

Patients aged <60 years were more often male (P = .023), had a higher body mass index (P = .001), higher rates of previous surgery (57% vs. 27%, P < .001), higher rates of post-traumatic arthritis (11% vs. 5%, P < .001) and inflammatory arthropathy (13% vs. 4%, P < .001), and lower rates of rotator cuff tear arthropathy (25% vs. 38%, P = .006). There were no differences in ROM between the groups but patients aged <60 years had significantly lower function and outcome metric scores and higher pain scores at latest follow-up. Adverse event rates were similar between the 2 groups, but patients aged <60 years were more likely to require revision (5.2% vs. 1.8%, P = .004). Patients aged <60 years also had lower satisfaction scores (much better/better 86% vs. 92%, P = .006).

CONCLUSION

At a mean follow-up of 47 months, primary rTSA patients aged <60 years had worse clinical outcomes compared with those aged 60-79 years, with lower outcome scores, increased pain, lower function scores, and less patient satisfaction. Patients aged <60 years had higher rates of previous surgery, inflammatory arthropathy, and post-traumatic arthritis, whereas those aged 60-79 years had higher rates of rotator cuff tear arthropathy. Although complications were similar, younger patients had 3 times the risk of revision rTSA.

Postoperative Nursing and Functional Rehabilitation of Ultrasound Diagnosis of Lower Rotator Cuff Injury

In order to explore the postoperative nursing effect and functional rehabilitation of rotator cuff repair under ultrasound diagnosis, a method of nursing and rehabilitation functional training for athletes' wrist injury under the assistance of microscopic B-ultrasound was proposed. This study retrospectively analyzed the therapeutic effect of tendon anastomosis in 237 patients with wrist tendon injury, adopted nursing measures such as health education and functional exercise, and observed its clinical effect. The results showed that after 3-6 months of follow-up, all patients had satisfactory recovery of tendon function. Of these, 132 patients recovered well. 84 patients recovered well. The excellent and good rate of patients was 91%. Ultrasound diagnosis of rotator cuff repair combined with functional exercise promotes good recovery of shoulder joint function in patients.

[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.

[Conventional radiological markers in rotator cuff surgery]

The surgical management of a degenerative or traumatic lesion of the shoulder joint is based on anatomical, clinical, and radiologic criteria. To optimize the diagnostic and therapeutic management of patients, the use of radiological imaging must be accompanied by meticulous clinical examination first. Conventional radiography is an effective complementary exam to assess the nature of shoulder joints injuries. Many conventional radiographic markers have been described, mainly for degenerative rotator cuff lesions, and are routinely used by clinicians as a screening tool. The aim of this review was to describe these different markers and define their reliability and usefulness in avoiding more expensive imaging modalities.

Histologic Differences in Human Rotator Cuff Muscle Based on Tear Characteristics

BACKGROUND

Fatty accumulation in the rotator cuff is associated with shoulder dysfunction and a risk of failure of rotator cuff repair. The aims of this study were to (1) describe cellular findings in rotator cuff muscles in patients presenting with varying degrees of rotator cuff tendon pathology by examining fat content and myofiber cross-sectional area of rotator cuff muscles and (2) correlate histologic features to magnetic resonance imaging (MRI) grades derived with the Goutallier classification.

METHODS

Rotator cuff muscle biopsies were performed in a consecutive series of patients undergoing arthroscopic shoulder surgery. Rotator cuffs were graded according to the Goutallier classification and labeled as either partial-thickness or full-thickness. Patients without a rotator cuff tear undergoing arthroscopic surgery served as controls. The biopsy specimens were examined using LipidTOX to visualize lipid accumulation. Laminin was used to quantify myofiber cross-sectional area.

RESULTS

Twenty-seven patients with a rotator cuff tear and 12 without a tear (controls) were included. There were 24 males (62%). The mean age was 55 years. Patients in the control cohort were younger (mean, 46 years) than those in the treatment group (mean, 60 years, p < 0.01). Within the treatment group, 12 and 15 patients were recorded as having partial and full-thickness rotator cuff tears, respectively. Lipid accumulation visualized at the cellular level was fairly-to-moderately correlated with the Goutallier classification on MRI (R s = 0.705, 95% confidence interval [CI] = 0.513, 0.829). Muscle biopsy specimens with a Goutallier grade of 2+ had significantly more lipid accumulation than those with grade-0 (p < 0.01) or grade-1 (p < 0.01) fatty accumulation. Muscle biopsies at the sites of full-thickness tears showed significantly greater lipid accumulation than those associated with either partial (p < 0.01) or no (p < 0.01) tears. Partial-thickness rotator cuff tears had no difference in lipid accumulation in comparison to the control group. Muscle biopsy specimens from full-thickness tears had significantly smaller myofiber cross-sectional area when compared with partial-thickness tears (p = 0.02) and controls (p < 0.01).

CONCLUSIONS

Cellular lipid accumulation correlates with the MRI Goutallier grade of fatty accumulation, thus verifying the Goutallier classification at the cellular level. Muscle biopsy specimens from partial-thickness tears are more similar to controls than to those from full-thickness tears, whereas full-thickness tears of all sizes showed significantly greater lipid content and smaller myofiber cross-sectional area compared with partial-thickness tears and controls.

CLINICAL RELEVANCE

Our research confirms the utility of using the Goutallier classification to predict rotator cuff muscle quality and shows that tendon attachment, even if partially torn, protects the muscle from fatty accumulation.

Persistent Shoulder Pain After Vaccine Administration Is Associated with Common Incidental Pathology: A Systematic Review

BACKGROUND

Claims of shoulder injury now account for half of all claims to the Vaccine Injury Compensation Program. Reports from databases of claims or potential adverse events note a relatively high mean age and high prevalences of rotator cuff tendinopathy and adhesive capsulitis-common shoulder problems that might be incidental to vaccination. Published case reports provide much more detail about individual patients than is available in databases. A review of published cases provides an opportunity for more detailed review of symptoms, diagnoses, pathology, treatment, and prognosis. Such a review can better assess the relative likelihood that pathologies associated with new persistent shoulder symptoms after vaccination are coincidental or unique to and caused by vaccine.

QUESTIONS/PURPOSES

Regarding published case reports addressing persistent shoulder pain after vaccination: (1) In what proportion of patients was a specific diagnosis made? (2) What diagnoses were most common? (3) Among patients treated nonsurgically, what proportion resolved, and over what time span did they resolve?

METHODS

In August 2020, we searched PubMed and Embase between 2006 and 2020 using the following search strategy: Search 1: (shoulder dysfunction OR shoulder pain OR shoulder bursitis OR rotator cuff tendonitis OR adhesive capsulitis OR glenohumeral arthritis AND [vaccine OR vaccination OR immunization]); Search 2: (shoulder injury related to vaccine administration or SIRVA). The search was supplemented by reviewing reference lists of identified studies. Inclusion criteria were any detailed report of three or fewer cases involving shoulder pain after vaccine administration. Twenty published reports of 29 patients were identified and assessed by two reviewers independently. One reported glenohumeral joint infection was excluded because the relationship between this type of relatively uncommon, discrete diagnosis and vaccination raises different considerations. We assumed a high risk of bias, although we are not aware of bias assessment tool for case reports. We recorded and summarized patient demographics, symptoms, examination and imaging findings, surgery findings, diagnoses, treatments, and outcomes. Seventy-five percent (21 of 28) of patients were women, with a mean age of 54 ± 19 years. In search of an underlying pathology, at least one diagnostic study was performed in 82% (23 of 28) of patients including radiographs in seven, ultrasound in seven, and MRI in 16 patients (some patients underwent more than one type of imaging). We distinguished specific pathophysiological diagnosis from shoulder pain and stiffness, counted the most common diagnoses among patients a specific diagnosis, and tracked symptom resolution among patients treated nonoperatively.

RESULTS

A specific diagnosis was made in 57% (16 of 28) of patients. Twelve patients had pain and limitation of motion due to pain but no specific pathological diagnosis. The most common specific diagnoses were rotator cuff tendinopathy (9 of 16) and adhesive capsulitis (4 of 16). Less common specific diagnoses included rotator cuff arthropathy (and rheumatoid arthritis) and suspected septic arthritis with nonspecific synovitis on arthroscopy. One patient had transient MRI signal change in the humeral head, which was interpreted as osteonecrosis that resolved in a manner not typical for that diagnosis. Of the 17 patients treated nonsurgically, 15 reported resolution, and two had incomplete symptom resolution with the mean 6-month evaluation period.

CONCLUSION

The observation that persistent shoulder pain after vaccination overlaps with common shoulder pathology-both in large databases as well as in more detailed reports of specific patients as analyzed in this review-establishes a high probability of a coincidental rather than a causal association. In the absence of high-quality experimental evidence of vaccine-specific shoulder pathology, in our opinion, it seems safest and healthiest to assume that perceived shoulder injury related to vaccine administration (SIRVA) is due to misinterpretation of new symptoms from established pathology rather than a new, vaccine-specific pathology.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Rotator Cuff Delamination Is Associated With Increased Tendon Retraction and Higher Fatty Muscle Infiltration: A Comparative Study on Arthroscopy and Magnetic Resonance Imaging

PURPOSE

To investigate (1) tendon delamination according to different rotator cuff tear patterns as well as (2) the association of tendon retraction and fatty muscle infiltration with delamination of the rotator cuff. Furthermore, we aimed to establish the accuracy of magnetic resonance imaging for the detection of rotator cuff delamination.

METHODS

Magnetic resonance imaging scans of patients who underwent arthroscopic rotator cuff repair from 2013 to 2015 were retrospectively compared to intraoperative findings. Prevalences of tendon delamination, tendon retraction, and fatty muscle infiltration were categorized according to different rotator cuff tear patterns. For comparability of the amount of tendon retraction of delaminated and non-delaminated rotator cuff tears, we introduced the global retraction index, a description individually assessing tendon retraction in magnetic resonance imaging scans of all visible layers.

RESULTS

Of 349 shoulders, tendon delamination was observed in 231 patients (66.2%). Of these, rotator cuff delamination was most commonly seen in posterosuperior rotator cuff tears (84.6%). Delaminated rotator cuff tears presented with a significantly higher global retraction index (P < .001) as well as higher fatty muscle infiltration of the supraspinatus (P = .001) and infraspinatus (P = .001). Magnetic resonance imaging had only moderate accuracy (57.3%) to detect rotator cuff delamination, with a positive predictive value of 100% (95% confidence interval [CI] 95.6% to 100.0%) and a negative predictive value of 44.2% (95% CI 38.1% to 50.4%).

CONCLUSIONS

Tendon delamination was most commonly observed in posterosuperior rotator cuff tears. Delaminated rotator cuff tears showed a significantly greater tendon retraction as well as a higher amount of fatty muscle infiltration of the supraspinatus and infraspinatus. Magnetic resonance imaging has only moderate accuracy for detection of rotator cuff delamination.

LEVEL OF EVIDENCE

III, retrospective cohort study.

[Development of a risk stratification model for subscapularis tendon tear based on patient-specific data from 528 shoulder arthroscopy]

OBJECTIVE

To identify and screen sensitive predictors associated with subscapularis (SSC) tendon tear and develop a web-based dynamic nomogram to assist clinicians in early identification and intervention of SSC tendon tear.

METHODS

Between July 2016 and December 2021, 528 consecutive cases of patients who underwent shoulder arthroscopic surgery with completely MRI and clinical data were retrospectively analyzed. Patients admitted between July 2016 and July 2019 were included in the training cohort, and patients admitted between August 2019 and December 2021 were included in the validation cohort. According to the diagnosis of arthroscopy, the patients were divided into SSC tear group and non-SSC tear group. Univariate analysis, least absolute shrinkage and selection operator (LASSO) method, and 10-fold cross-validation method were used to screen for reliable predictors highly associated with SSC tendon tear in a training set cohort, and R language was used to build a nomogram model for internal and external validation. The prediction performance of the nomogram was evaluated by concordance index (C-index) and calibration curve with 1 000 Bootstrap. Receiver operating curves were drawn to evaluate the diagnostic performance (sensitivity, specificity, predictive value, likelihood ratio) of the predictive model and MRI (based on direct signs), respectively. Decision curve analysis (DCA) was used to evaluate the clinical implications of predictive models and MRI.

RESULTS

The nomogram model showed good discrimination in predicting the risk of SSC tendon tear in patients [C-index=0.878; 95% CI(0.839, 0.918)], and the calibration curve showed that the predicted results were basically consistent with the actual results. The research identified 6 predictors highly associated with SSC tendon tears, including coracohumeral distance (oblique sagittal) reduction, effusion sign (Y-plane), subcoracoid effusion sign, biceps long head tendon displacement (dislocation/subluxation), multiple posterosuperior rotator cuff tears (≥2, supra/infraspinatus), and MRI suspected SSC tear (based on direct sign). Compared with MRI diagnosis based on direct signs of SSC tendon tear, the predictive model had superior sensitivity (80.2% vs. 57.0%), positive predictive value (53.9% vs. 53.3%), negative predictive value (92.7% vs. 86.3%), positive likelihood ratio (3.75 vs. 3.66), and negative likelihood ratio (0.25 vs. 0.51). DCA suggested that the predictive model could produce higher clinical benefit when the risk threshold probability was between 3% and 93%.

CONCLUSION

The nomogram model can reliably predict the risk of SSC tendon tear and can be used as an important tool for auxiliary diagnosis.

Prediction of Bilaterality in Patients With 1 Posterosuperior Rotator Cuff Tear

BACKGROUND

In patients with a known unilateral posterosuperior rotator cuff tear (PSRCT), the ability to predict a contralateral PSRCT may assist in earlier diagnosis and improved patient outcomes.

PURPOSE

To determine factors associated with bilateral PSRCT and their most predictive combinations using a nonhospitalized general population.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This study involved 736 individuals (n = 1472 shoulders) drawn from a rural cohort. PSRCT was diagnosed using magnetic resonance imaging. Symptoms of the contralateral shoulder were not considered. The demographic, physical, social, metabolic, and imaging factors, as well as comorbidities, were evaluated using logistic regression analysis. Cutoff values for the significantly associated variables obtained from multivariable logistic regression analysis were calculated using the receiver operating characteristic (ROC) curve. The areas under the ROC curve (AUCs) of the combinations of significantly associated variables were compared using the DeLong method to determine the combination most predictive of bilateral PSRCT. The likelihood ratio and the posttest probability for each of the combinations were assessed.

RESULTS

Age ≥61 years, manual labor, critical shoulder angle (CSA) ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome were significantly associated with bilateral PSRCT in multivariable analysis (P < .001). The 1-by-1 combination of any 4 of the 6 associated factors significantly increased the AUC of any smaller combinations of those 6 factors (P < .001). The AUCs of the 4-somes were all similar (P ≥ .383) and were not significantly increased by further addition of identified associated factors (P ≥ .422). Any combination of 4 of the 6 associated factors was highly predictive of bilateral PSRCT, each having a minimum AUC of 0.70, a likelihood ratio of >10, and a minimum posttest probability of 80%.

CONCLUSION

Unilateral PSRCT, accompanied by any 4 of the variables of age ≥61 years, manual labor, CSA ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome, is highly predictive of PSRCT in the other shoulder.

Is Advanced Imaging to Assess Rotator Cuff Integrity Before Shoulder Arthroplasty Cost-effective? A Decision Modeling Study

BACKGROUND

Shoulder arthroplasty is increasingly performed for patients with symptoms of glenohumeral arthritis. Advanced imaging may be used to assess the integrity of the rotator cuff preoperatively because a deficient rotator cuff may be an indication for reverse shoulder arthroplasty (RSA) rather than anatomic total shoulder arthroplasty (TSA). However, the cost-effectiveness of advanced imaging in this setting has not been analyzed.

QUESTIONS/PURPOSES

In this cost-effectiveness modeling study of TSA, all patients underwent history and physical examination, radiography, and CT, and we compared (1) no further advanced imaging, (2) selective MRI, (3) MRI for all, (4) selective ultrasound, and (5) ultrasound for all.

METHODS

A simple chain decision model was constructed with a base-case 65-year-old patient with a 7% probability of a large-to-massive rotator cuff tear and a follow-up of 5 years. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with a willingness to pay of both USD 50,000 and 100,000 per quality-adjusted life year (QALY) used, in accordance with the Second Panel on Cost-Effectiveness in Health and Medicine. Diagnostic test sensitivity and specificity were extracted from published systematic reviews and meta-analyses, and patient utilities were obtained using the Cost-Effectiveness Analysis Registry from the Center for the Evaluation of Value and Risk in Health. Final patient states were categorized as either inappropriate or appropriate based on the actual rotator cuff integrity and type of arthroplasty performed. Additionally, to evaluate the real-world impact of intraoperative determination of rotator cuff status, a secondary analysis was performed where all patients indicated for TSA underwent intraoperative rotator cuff examination to determine appropriate implant selection.

RESULTS

Selective MRI (ICER of USD 40,964) and MRI for all (ICER of USD 79,182/QALY) were the most cost-effective advanced imaging strategies at a willingness to pay (WTP) of USD 50,000/QALY gained and 100,000/QALY gained, respectively. Overall, quality-adjusted life years gained by advanced soft tissue imaging were minimal: 0.04 quality-adjusted life years gained for MRI for all. Secondary analysis accounting for the ability of the surgeon to alter the treatment plan based on intraoperative rotator cuff evaluation resulted in the no further advanced imaging strategy as the dominant strategy as it was the least costly (USD 23,038 ± 2259) and achieved the greatest health utility (0.99 ± 0.05). The sensitivity analysis found the original model was the most sensitive to the probability of a rotator cuff tear in the population, with the value of advanced imaging increasing as the prevalence increased (rotator cuff tear prevalence greater than 12% makes MRI for all cost-effective at a WTP of USD 50,000/QALY).

CONCLUSION

In the case of diagnostic ambiguity based on physical exam, radiographs, and CT alone, having both TSA and RSA available in the operating room appears more cost-effective than obtaining advanced soft tissue imaging preoperatively. However, performing selective MRI to assess rotator cuff integrity to indicate RSA or TSA is cost-effective if surgical preparedness, patient expectations, and implant availability preclude the ability to switch implants intraoperatively.

LEVEL OF EVIDENCE

Level III, economic and decision analysis.