Tendon stump type on magnetic resonance imaging is a predictive factor for retear after arthroscopic rotator cuff repair

Re-tear after arthroscopic rotator cuff tear surgery: risk analysis using machine learning

BACKGROUND

Postoperative rotator cuff retear after arthroscopic rotator cuff repair (ARCR) is still a major problem. Various risk factors such as age, gender, and tear size have been reported. Recently, magnetic resonance imaging-based stump classification was reported as an index of rotator cuff fragility. Although stump type 3 is reported to have a high retear rate, there are few reports on the risk of postoperative retear based on this classification. Machine learning (ML), an artificial intelligence technique, allows for more flexible predictive models than conventional statistical methods and has been applied to predict clinical outcomes. In this study, we used ML to predict postoperative retear risk after ARCR.

METHODS

The retrospective case-control study included 353 patients who underwent surgical treatment for complete rotator cuff tear using the suture-bridge technique. Patients who initially presented with retears and traumatic tears were excluded. In study participants, after the initial tear repair, rotator cuff retears were diagnosed by magnetic resonance imaging; Sugaya classification types IV and V were defined as re-tears. Age, gender, stump classification, tear size, Goutallier classification, presence of diabetes, and hyperlipidemia were used for ML parameters to predict the risk of retear. Using Python's Scikit-learn as an ML library, five different AI models (logistic regression, random forest, AdaBoost, CatBoost, LightGBM) were trained on the existing data, and the prediction models were applied to the test dataset. The performance of these ML models was measured by the area under the receiver operating characteristic curve. Additionally, key features affecting retear were evaluated.

RESULTS

The area under the receiver operating characteristic curve for logistic regression was 0.78, random forest 0.82, AdaBoost 0.78, CatBoost 0.83, and LightGBM 0.87, respectively for each model. LightGBM showed the highest score. The important factors for model prediction were age, stump classification, and tear size.

CONCLUSIONS

The ML classifier model predicted retears after ARCR with high accuracy, and the AI model showed that the most important characteristics affecting retears were age and imaging findings, including stump classification. This model may be able to predict postoperative rotator cuff retears based on clinical features.

Arthroscopic superior capsule reconstruction augmentation using a semitendinosus autograft in massive reparable rotator cuff tears

Background

Arthroscopic superior capsule reconstruction (SCR) augmentation is a viable treatment option for massive reparable cuff tears. This study aimed to retrospectively compare clinical and imaging outcomes of patients with reparable massive rotator cuff tears after arthroscopic rotator cuff repair (ARCR) with those after SCR augmentation using a semitendinosus autograft.

Methods

We retrospectively compared 50 patients with massive reparable rotator cuff tears who underwent ARCR and SCR augmentation (n = 25 each). Patients were clinically followed up for at least 2 years, and the American Shoulder and Elbow index, other patient-reported outcomes, active range of motion, and radiography and magnetic resonance imaging findings were assessed.

Results

At the final follow-up, both patient groups showed significant improvements in forward elevation in range of motion and visual analog scale scores. Improvements in the American Shoulder and Elbow scores in the SCR augmentation group were significantly superior to those in the ARCR group (48.3 and 28.9, P < .01). There was a significant difference in the retear rate between the SCR augmentation group and ARCR group (20% and 56%, respectively; P = .009).

Conclusion

Our study demonstrated that patient-reported outcomes and retear rates in patients who underwent SCR augmentation with rotator cuff repair for massive rotator cuff tears significantly improved compared with those in patients who underwent ARCR without augmentation. Augmentation with semitendinosus autografting during rotator cuff repair represents a solution for patients with massive reparable rotator cuff tears.

Clinical efficacy and tendon integrity of patients with subscapularis tear by the technique of arthroscopic single external row repair

Background

With the development of arthroscopic technology and equipment, arthroscopy can effectively repair the tear of the subscapular muscle. However, it is difficult to expose the subscapular muscle and operate it under a microscope. In this study, the SwiveLock® C external row anchor under arthroscopy was applied to repair the tear of the subscapular muscle in a single row, which is relatively easy to operate with reliable suture and fixation, and its efficacy was evaluated.

Purpose

This study aimed to assess the clinical efficacy and the tendon integrity of patients who had subscapularis tears by adopting the single-row repair technique with a SwiveLock® C external row anchor.

Methods

Patients who had the subscapular muscle tear either with or without retraction were included, and their follow-up time was at least 1 year. The degree of tendon injury was examined by magnetic resonance imaging (MRI) and confirmed by arthroscopy. The tendon was repaired in an arthroscopic manner by utilizing the single-row technique at the medial margin of the lesser tuberosity. One double-loaded suture SwiveLock® C anchor was applied to achieve a strong fixation between the footprint and tendon. The range of motion, pain visual simulation score, American Shoulder and Elbow Surgeons (ASES) score, and Constant score of shoulder joint were evaluated for each patient before the operation, 3 months after the operation, and at least 1 year after the operation.

Results

In total, 110 patients, including 31 males and 79 females, with an average age of 68.28 ± 8.73 years were included. Arthroscopic repair of the subscapular tendon with SwiveLock® C external anchor can effectively improve the range of motion of the shoulder joint. At the last follow-up, the forward flexion of the shoulder joint increased from 88.97 ± 26.33° to 138.38 ± 26.48° (P < 0.05), the abduction range increased from 88.86 ± 25.27° to 137.78 ± 25.64° (P < 0.05), the external rotation range increased from 46.37 ± 14.48° to 66.49 ± 14.15° (P < 0.05), and the internal rotation range increased from 40.03 ± 9.01° to 57.55 ± 7.43° (P < 0.05). The clinical effect is obvious. The constant shoulder joint score increased from 40.14 ± 15.07 to 81.75 ± 11.00 (P < 0.05), the ASES score increased from 37.88 ± 13.24 to 82.01 ± 9.65 (P < 0.05), and the visual analog scale score decreased from 5.05 ± 2.11 to 1.01 ± 0.85 (P < 0.05). In the 6th month after the operation, two cases (1.81%) were confirmed to have re-tears via MRI.

Conclusion

In this study, we repaired the subscapularis muscle with a single-row technique fixed by SwiveLock® C anchor and FiberWire® sutures and evaluated its efficacy. The results showed that the clinical effect of single-row arthroscopic repair was satisfactory and that reliable tendon healing could be achieved.

Association of Severe Histological Degeneration of the Torn Supraspinatus Tendon and Retear After Arthroscopic Repair of Full-Thickness Rotator Cuff Tears Using the Suture Bridge Technique

BACKGROUND

Previous studies have demonstrated several prognostic factors for retear after arthroscopic rotator cuff repair (ARCR). However, studies that histologically evaluate the quality of the torn rotator cuff (RC) tendon and its association with postoperative outcomes are limited.

PURPOSE

To investigate factors associated with retear after ARCR using the suture bridge (SB) technique, including the degree of histological degeneration of the RC tendon edge.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors retrospectively evaluated 187 patients who underwent ARCR for full-thickness tears using the SB technique; intraoperative biopsy samples were taken to assess the degree of histological degeneration using the Bonar score. The cohort was divided into healed (n = 165) and retear (n = 22) groups according to magnetic resonance imaging results obtained ≥6 months postoperatively. The evaluation included preoperative patient data (age, sex, symptom duration, trauma history, history of heavy manual work, smoking habit, hypertension, diabetes mellitus, and hyperlipidemia) and radiological data (Hamada classification, Patte classification, Goutallier classification, and global fatty degeneration index [GFDI]). Additionally, intraoperative data (anteroposterior tear size, Lafosse classification for concomitant subscapularis tendon tear, and long head of biceps injury) and preoperative and postoperative clinical findings (active range of motion, University of California, Los Angeles [UCLA], score) were evaluated.

RESULTS

The retear rate was 11.8%. The retear group had a higher percentage of men (P = .031), higher Bonar score (P < .001), higher mean GFDI value (P = .002), higher rate of tear retraction degree (P = .010), and larger anteroposterior tear size (P = .020) than the healed group. The retear group had lower postoperative internal rotation (P = .031) and lower UCLA score (P < .001). Multivariate logistic regression analysis with a stepwise variable selection revealed anteroposterior tear size (odds ratio [OR], 2.4; 95% CI, 1.3-4.5; P = .004) and Bonar score (OR, 1.7; 95% CI, 1.3-2.4; P < .001) as independent predictors for a retear.

CONCLUSION

The results indicate that end-stage severe tendon degeneration might affect retear. Therefore, further investigation on the progression mechanisms of tendon degeneration and development of methods to assess degenerative tissue might improve clinical outcomes after ARCR.

Relationship between hematoma-like tissue on the footprint and structural outcome of arthroscopic rotator cuff repair with a transosseous technique

Background

We have tried to create hematoma over the footprint site at the end of arthroscopic rotator cuff repair (ARCR) surgery, expecting to apply biochemical effects of the platelet-related factors. The purpose of this study was to investigate the presence of hematoma-like tissue (HLT) on postoperative magnetic resonance imaging, and to evaluate the relationship between the HLT and the structural outcomes of ARCR.

Materials and methods

Twenty-five patients were reviewed with a mean age at surgery of 69.8 years (range, 52-85 years). Postoperative magnetic resonance imaging was performed at 1 week, 6-8 weeks, and >6 months postoperatively. Structural outcomes for the repaired cuff and thickness of HLT were evaluated on coronal T2-weighted images. Signal intensity of HLT was evaluated on coronal T2-weighted fat-suppressed images as the ratio compared to supraspinatus tendon intensity (HLT/SSP ratio).

Results

Structural outcomes showed Sugaya type 1 in 12 shoulders, type 2 in 4, and type 3 in 9. HLT thickness was significantly thicker at 1 week and 6-8 weeks postoperatively in Sugaya type 1 patients than in type 3 patients (1 week; P = .014, 6-8 weeks; P < .001). HLT/SSP ratio gradually decreased (at 1 week; 1.9 ± 0.7, 6-8 weeks; 1.6 ± 0.6, >6 months; 1.2 ± 0.5), and differed significantly between >6 months and both 1 week and 6-8 weeks (P < .001 each).

The clinical outcomes of infraspinatus rotational transfer for irreparable posterosuperior rotator cuff tears: a preliminary report

Background

This study aimed to examine the preliminary clinical results of the infraspinatus rotational transfer procedure for irreparable posterosuperior rotator cuff tears.

Methods

This study included 34 patients (mean age, 68.4 years). Their mean tear width and length measurements were 50.9 mm and 50.6 mm, respectively. The functional outcomes, including physician-determined and patient-reported scores, were evaluated before and at 1 year after surgery. The structural outcomes determined using the magnetic resonance imaging examination results were also assessed.

Results

The clinical scores significantly improved after surgery compared with the scores before surgery: the Constant-Murley score (53.3±21.1 to 76.8±10.5), University of California at Los Angeles Shoulder score (15.6±3.6 to 27.8±6.7), American Shoulder and Elbow Surgeons Shoulder score (51.8±18.3 to 89.1±13.5), and WORC score (925.0±436.8 to 480.3±373.2) (all p<0.001). Postoperative re-tears were noted in two patients (5.9%).

Conclusions

One year postoperatively, the patient’s clinical scores significantly improved, with a re-tear rate of 5.9%.

Biochemical Markers of Aging (Advanced Glycation End Products) and Degeneration Are Increased in Type 3 Rotator Cuff Tendon Stumps With Increased Signal Intensity Changes on MRI

BACKGROUND

Advanced glycation end products (AGEs) are end products of protein glycation that bind to the receptor for AGEs (RAGE) and activate nicotinamide adenine dinucleotide phosphate oxidase (NOX), resulting in increased oxidative stress and rotator cuff fragility. Stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of T2-weighted fat-suppressed magnetic resonance imaging (MRI) scans is an indicator of clinical outcomes after rotator cuff repair surgery. Comparing the signal intensities of the deltoid (D) and rotator cuff tears (C), Ishitani et al. classified C/D <0.8 as type 1, 0.8 to 1.3 as type 2, and >1.3 as type 3.

HYPOTHESIS/PURPOSE

It was hypothesized that the oxidative stress and collagen degeneration that occur in the rotator cuff due to accumulation of AGEs can be assessed on MRI scans (stump classification). Therefore, this study aimed to compare AGE-related factors in the rotator cuff tear site tissues based on stump classification.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The authors included 30 patients (11 with type 1, 9 with type 2, and 10 with type 3; mean age, 62.3 years) who underwent surgery for complete rotator cuff tears at our hospital. Tendon tissue was harvested from the torn rotator cuff site during surgery for tissue and cell evaluation.

RESULTS

There was no significant difference in the mean age according to stump classification. The number of patients with diabetes was significantly larger in type 3 than in the other types (P < .05). Tissue evaluation showed significantly higher expression of AGE and RAGE staining in type 3 than in the other types (~6.7-fold; P < .01). Cell evaluation showed that the expression rates of reactive oxygen species and apoptosis were significantly higher in type 3 than in the other types (~4.3-fold; P < .01). Gene expression by real-time polymerase chain reaction showed significantly higher RAGE (~5.1-fold), NOX (~5.3-fold), and IL (~3.0-fold) in type 3 than in the other types (P < .05).

CONCLUSION

Stump classification type 3 exhibited the highest accumulation of AGEs and the highest oxidative stress and apoptosis, suggesting a high degree of degeneration and inflammation. Imaging based on stump classification reflects the degeneration and fragility of the torn rotator cuff site.

CLINICAL RELEVANCE

This study provides evidence of a relationship between stump classification, which reflects rotator cuff fragility on MRI, and pathologies related to advanced glycation end products.

Relevance between Proximal Humeral Migration and Rotator Cuff Tears

Background

Proximal humeral migration is common in patients with rotator cuff tears. In this study, we aimed to evaluate the relevance between proximal humeral migration and some rotator cuff tear-related factors.

Methods

A total of 75 patients with unilateral rotator cuff tears were retrospectively included from August 2016 to January 2018 who underwent magnetic resonance imaging and X-ray examinations before enrollment. We introduced the upward migration index (UMI) to stratify the patients into three groups, Group A: 1 &lt; UMI ≤ 1.3; Group B: 1.3 &lt; UMI ≤ 1.4; and Group C: UMI &gt; 1.4. Pearson correlation analysis and logistic regression analysis were used to evaluate the relationship between UMI and age, sex, body mass index, pain, fatty degeneration grade, tear size, and thickness of ruptured tendon. Then, the χ2 test and receiver operator characteristic curve were applied to measure the diagnostic value of UMI.

Results

The average UMI was 1.34 ± 0.07, ranging from 1.16 to 1.48. For the Pearson correlation analysis, there was a negative correlation between UMI and tear size (R = −0.68, p &lt; 0.01), and also, there was a negative correlation between UMI and the visual analogue scale score (R = 0.342, p &lt; 0.01). What is more, there was a negative correlation between UMI and the fatty degeneration grade (R = −0.373, p &lt; 0.01). Ordinal multinomial logistic regression analysis indicated that tear size (β = −1.825, p &lt; 0.001) was the independent predictor of UMI, which was a risk factor for humeral upward migration. The cutoff points of UMI were 1.38 and 1.3 to determine tears and distinguish large tears from small ones.

Conclusions

UMI is a good predictor for humeral upward migration, which is related to the tear size of posterosuperior cuff tears. When the UMI is &lt;1.3, a large tear should be alerted. Combining physical examination and X-ray is helpful for evaluating rotator cuff tears.

Stump classification was correlated with retear in the suture-bridge and double-row repair techniques for arthroscopic rotator cuff repair

PURPOSE

The Stump classification is significantly correlated with a retear after arthroscopic rotator cuff repair. However, no study has evaluated whether or not the stump classification is correlated with retear in the suture-bridge or double-row repair techniques. The aim of this study was to evaluate the relationship between a retear and the stump classification in the suture-bridge and double-row repair techniques.

METHODS

Among 389 patients who underwent arthroscopic repairs of full-thickness rotator cuff tears using suture-bridge or double-row repair techniques, 326 patients (median age 67.0 years; range 25-85) were included. There were 51 small, 172 medium, 83 large, and 20 massive tears. Two hundred forty patients were treated with the suture-bridge technique, and 86 patients were treated with the double-row technique. The following variables were analyzed: age, sex, the Cofield classification, anteroposterior and mediolateral tear size on preoperative MRI, global fatty degeneration index, and the stump classification. Cuff integrity was evaluated on magnetic resonance imaging at 6 months after surgery. The patients were divided into the intact and retear groups and the relationship between the variables and retear was evaluated by multivariate logistic regression analysis.

RESULTS

The overall retear rate was 10.1%. In the multivariate logistic regression analysis, the independent predictors of a retear were the stump classification type 3 (Odds ratio: 4.71, p = 0.0246), global fatty degeneration index (Odds ratio: 3.87, p = 0.0030), and anteroposterior tear size (Odds ratio: 1.07, p = 0.0077) in the suture bridge technique. In the double-row technique, the independent predictors of retear were stump classification type 3 (Odds ratio: 7.82, p = 0.0348), and age (Odds ratio: 1.22, p = 0.0163).

CONCLUSION

The stump classification was significantly correlated with retear in the suture-bridge and double-row repair technique. Stump classification type 3 was indicated to be an important risk factor for predicting retear.

LEVEL OF EVIDENCE

III.

Risk factors for and prognosis of folded rotator cuff tears: a comparative study using propensity score matching

BACKGROUND

The prognosis of rotator cuff repair (RCR) may be affected by the shape and quality of the torn rotator cuff tendon. However, only a few studies have reported on folded rotator cuff tears (FCTs). Therefore, this study aimed to evaluate the prognostic factors for FCT and clinical outcomes of FCT repair.

METHODS

Through propensity score matching (PSM), 200 (40 patients with FCTs and 160 controls) of 1927 patients who underwent RCR from 2010 to 2016 were included. The variables not used for PSM were compared. The anatomic and functional outcomes were assessed at the final follow-up (32.3 ± 21.2 months), and the related prognostic factors for FCTs were evaluated.

RESULTS

The risk factors for FCT were heel-type spur (odds ratio [OR], 11.6; P < .001) and delamination (OR, 2.3; P = .034). Although the functional scores at the final follow-up for both groups improved postoperatively and were not significantly different, the visual analog scale scores for pain (1.9 ± 2.1 vs. 1.2 ± 1.7, P = .034) and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (83.1 ± 14.3 vs. 88.5 ± 12.2, P = .018) were significantly worse in the FCT group at 6 months postoperation. The retear rate was significantly higher in the FCT group (25.0 vs. 10.0%, P = .018). An FCT was a significant risk factor for retears (OR, 3.0; P = .015); however, a subgroup analysis revealed that the retear rate according to the management strategy for the folded portion (débridement of the folded portion vs. en masse repair including the folded portion) was not significantly different (26.7 vs. 24.0%, P > .99).

CONCLUSION

The risk factors for FCTs were heel-type spur and delamination. The retear rate was significantly higher for patients with FCTs. An FCT was indicative of poor quality of the remaining tendon; therefore, FCT may be a prognostic factor for worse functional outcomes during the early postoperative period and poor healing potential.

Effectiveness of measuring tension during arthroscopic rotator cuff repair

Purpose

Arthroscopic rotator cuff repair (ARCR) for relatively small rotator cuff tears (RCTs) has shown promising results; however, such surgery for larger tears often results in failure and poor clinical outcomes. One cause of failure is over-tension at the repair site that will be covered with the tendon stump. Reports on the clinical outcomes using ARCR with tension ≤ 30 N are lacking. This study aimed to evaluate ARCR outcomes and failure rates using less tension (30 N) and to assess the prognostic factors for failure.

Methods

Our study group comprised of 118 patients who underwent ARCR for full-thickness RCTs with full tendon stump coverage of the footprint with a tension of ≤ 30 N, measured using a tension meter; no additional procedures, such as margin convergence or footprint medialisation, were performed. The failure rate was calculated, and the prognostic factor for failure was assessed using multivariate regression analyses.

Results

There were seven cases of failure in the study group. Postoperatively, flexion and internal rotation ranges of motion, acromiohumeral interval, muscle strength, and clinical results improved significantly. Using multivariate regression analyses, intraoperative concomitant subscapularis tendon lesion and pre-operative infraspinatus tendon retraction, assessed using radial-sequence magnetic resonance imaging, were significantly correlated with post-ARCR failure using less tension (p = 0.030 and p = 0.031, respectively).

Conclusion

ARCR is likely to succeed for RCTs that can be extracted using tension ≤ 30 N. However, cases with more severe subscapularis tendon lesions and those with high infraspinatus tendon retraction may show surgical failure.

Level of evidence

LEVEL IV Retrospective case series