The effect of rotator cuff malreduction on tendon tension: an evaluation of a custom-made digital tensiometer clamp

Arthroscopic Posterosuperior Cuff Muscle Advancement with Linked-Double Row Repair: Yes, I'll Have My Cake and Eat It Too!

The goal of massive, retracted rotator cuff repair surgery is structural healing that produces pain relief and strength restoration. Healing is difficult to achieve in patients with large, retracted, chronic, and fatty degenerated tears. High repair tension has previously been shown to be a risk factor for clinically and structurally failed repairs. Repair tension can be decreased by arthroscopic mobilization of the supraspinatus and infraspinatus muscle bellies (AMA) from their scapular origins with subsequent lateralization of the muscle-tendon units toward the repair site. Linked-double row repair of the tendons after AMA has been shown to improve the outcomes of repairs in high-risk rotator cuff repairs. Surgeons should consider adding AMA to their intraoperative armamentarium for use in retracted cuff tears where traditional techniques fail to achieve a low-tension repair state.

Excessively High Repair Tension Decreases Microvascular Blood Flow Within the Rotator Cuff

BACKGROUND

Repair tension and microvascular blood flow within the rotator cuff has a critical impact on tendon healing after rotator cuff repair. However, the relationship between repair tension and microvascular blood flow within the rotator cuff remains unclear.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine how much tension adversely affects microvascular blood flow within the rotator cuff. The hypothesis was that as the repair tension increases, the microvascular blood flow within the rotator cuff decreases.

STUDY DESIGN

Controlled laboratory study.

METHODS

Repair tension and microvascular blood flow within the rotator cuff of 30 patients with full-thickness rotator cuff tears were simultaneously measured using a digital tension meter and a contact-type laser Doppler flowmeter, respectively. Microvascular blood flow was measured under 4 levels of tension (0, 10, 20, and 30 N) at 5 points on the rotator cuff. The obtained values were statistically analyzed by a linear mixed-effects model to clarify the effect of tension on microvascular blood flow within the rotator cuff.

RESULTS

There was no statistically significant difference in microvascular blood flow (mL/min/100 g) within the rotator cuff between 0 N (mean, 3.51; 95% CI, 3.0-4.0) and 10 N (mean, 3.74; 95% CI, 3.2-4.3) of tension (P = .716). However, there were statistically significant differences in microvascular blood flow within the rotator cuff between 0 and 20 N of tension (mean, 2.84; 95% CI, 2.3-3.4) (P = .002) and between 0 and 30 N of tension (mean, 2.45; 95% CI, 1.9-3.0) (P < .001).

CONCLUSION/CLINICAL RELEVANCE

Our findings indicate that tension of ≥10 N during rotator cuff repair significantly decreases the microvascular blood flow within the rotator cuff. These data will contribute to determining the optimal repair tension during rotator cuff repair.

Factors correlated with the optimal tension for arthroscopic rotator cuff repair using Grasper Tensioning Attachment

BACKGROUND

Little is known about the optimal tension in arthroscopic rotator cuff repair (ARCR). This study aimed to identify preoperative, intraoperative, and postoperative factors that correlate with the tension in ARCR and to determine the optimal intraoperative tension using Grasper Tensioning Attachment, a tension meter attached to the common arthroscopic surgical grasper.

METHODS

This study included 63 patients with a mean age at surgery of 65.3 years (range, 45-83 years) who underwent ARCR. The mean follow-up period was 24.1 months (range, 24-28 months). We investigated the patients' demographic data, Japanese Orthopaedic Association score, DeOrio and Cofield classification, and Goutallier stage of the supraspinatus and infraspinatus muscles. We also evaluated cuff integrity based on the Sugaya classification via magnetic resonance imaging. The free edge of the torn retracted tendon was grasped, and the passive tension to the footprint was then measured with Grasper Tensioning Attachment with the arm at the side. The anteroposterior (AP) and mediolateral (ML) diameters were also measured.

RESULTS

The preoperative Goutallier stage of the supraspinatus muscle was stage 0 in 7 cases, stage 1 in 34, stage 2 in 20, and stage 3 in 2. The mean intraoperative rotator repair tension was 10.0 ± 2.5 N (range, 7.5-17 N). The mean AP diameter of the rotator cuff tear was 22 ± 10 mm (range, 8-50 mm), and the mean ML diameter was 24 ± 10 mm (range, 10-50 mm). Age, DeOrio and Cofield classification, Goutallier stage, AP diameter, and ML diameter correlated with rotator repair tension. The rotator repair tension in Sugaya classification type III or IV cases (n = 12, 11.4 ± 2.4 N) was significantly larger than that in type I or II cases (n = 51, 9.7 ± 2.4 N; P = .03). Tension ≥ 10 N as a cutoff value from receiver operating characteristic curve analysis was a risk factor for poor cuff integrity (95% confidence interval, 0.53-0.88).

CONCLUSIONS

Rotator repair tension ≥ 10 N was a risk factor for poor cuff integrity. Thus, care should be taken when performing intraoperative procedures and administering postoperative regimens.

Are there differences in arthroscopic and histological features between traumatic and degenerative rotator cuff tears in elderly patients? A prospective dual-center analysis

Background

Discriminating traumatic rotator cuff tears (RCTs) from degenerative RCTs is sometimes difficult in elderly patients because the prevalence of asymptomatic RCTs increases with age. Little intraoperative information is available on the characteristics of traumatic and degenerative RCTs in elderly patients. The purpose of this study was to compare the arthroscopic findings and histological changes of the coracoacromial ligament (CAL) between traumatic and degenerative RCTs in elderly patients.

Methods

Forty-two shoulders of 42 patients aged ≥ 65 years underwent arthroscopic rotator cuff repair. Nineteen patients had traumatic full-thickness RCTs (Group T), and 23 had degenerative full-thickness RCTs (Group D). The quality of the rotator cuff tissue and the condition of the long head of the biceps were examined. The grade of CAL was evaluated both arthroscopically and histologically. The stiffness of the musculotendinous unit was calculated by measuring the force and displacement using a tensiometer. The arthroscopic and histological findings of the two groups were compared.

Results

Although the mean tendon displacement was comparable, the stiffness was different between Group T and Group D (0.56 ± 0.31 and 1.09 ± 0.67 N/mm, respectively; p < 0.001). Both arthroscopic and histological analysis of the CAL showed that the degenerative changes in the CAL were milder in Group T than in Group D (p < 0.001 and p < 0.001, respectively). There was a moderate positive correlation between the arthroscopic findings of CAL degeneration and the histopathological changes in this ligament (r = 0.47, p = 0.002).

Conclusions

Traumatic RCTs were characterized by preserved elasticity of the musculotendinous unit and milder CAL degeneration compared with degenerative RCTs even in elderly patients.

Repair Tension During Arthroscopic Rotator Cuff Repair is Correlated With Preoperative Tendon Retraction and Postoperative Rotator Cuff Integrity

PURPOSE

This study aimed to examine the correlation of repair tension during arthroscopic rotator cuff repair (ARCR) with preoperative factors and to evaluate whether measuring tension during ARCR is effective for predicting rotator cuff integrity after ARCR.

METHODS

Patients who underwent ARCR from May 2014 to June 2017 were enrolled in this study. Inclusion criteria were patients with medium or larger-sized tears and with a minimum of 6 months' follow-up. Patients with a partial repair were excluded. Intraoperative repair tension was measured according to Davidson's method. Correlation of repair tension with preoperative factors was evaluated with Pearson and Spearman correlation coefficient tests. Logistic regression analysis was performed on intraoperative factors, including repair tension, to identify independent predictors of retear after ARCR. Receiver operating characteristic (ROC) curve was used to determine the cutoff value of repair tension for retear.

RESULTS

One-hundred twenty patients met the inclusion criteria. Mean repair tension was 26.6 ± 12.6 N, and retear was found in 29 shoulders (24.2%). Among the preoperative factors, tear size in the mediolateral (P < .001) and anteroposterior (P < .001) directions, DeOrio and Cofield's classification (P <0.001), geometric classification (P <.001), and fatty infiltration of supraspinatus (P = .006) and infraspinatus (P = .003) were significantly correlated with repair tension. However, multivariable logistic regression analysis identified only tear size in the mediolateral direction as an independent predictor of repair tension (P = .036). Logistic regression analysis showed that repair tension (P = .02) and geometric classification (P < .001) are significant factors affecting rotator cuff integrity after ARCR. ROC curve analysis showed the cutoff value of repair tension of large to massive tears for retear to be 35.6 N.

CONCLUSION

This study demonstrated that intraoperative repair tension is strongly correlated with tear size in the mediolateral direction based on preoperative magnetic resonance imaging and that measuring tension during ARCR is effective for predicting rotator cuff integrity after ARCR.

LEVEL OF EVIDENCE

Level IV, prognostic study.

Mobility Assessment of the Supraspinatus in a Porcine Cadaver Model Using a Sensor-Enhanced, Arthroscopic Grasper

Tendon mobility is highly relevant in rotator cuff surgery. Objective data about rotator cuff mobility is rare. Tendon mobility still needs to be evaluated subjectively by the surgeon. This study aims to establish a porcine animal model for mobility analysis of the supraspinatus. In this context, we introduce a sensor-enhanced, arthroscopic grasper (SEAG) suitable for objective intraoperative measurements of tendon mobility in clinical praxis. Tendon mobility of 15 fresh porcine cadaver shoulders with artificial rotator cuff tears was evaluated using the SEAG. Mobility characteristics (load–displacement curves, maximum load, stiffness) were studied and inter- and intraobserver agreement (intraclass correlation coefficient (ICC)) were tested. Factors with a potential adverse effect (plastic deformation and rigor mortis) were also evaluated. All shoulders showed characteristic reproducible load–displacement curves with a nonlinear part at the start, followed by a linear part. Mean maximum load was 28.6 N ± 12.5. Mean stiffness was 6.0 N/mm ± 2.6. We found substantial interobserver agreement (ICC 0.672) and nearly perfect intraobserver agreement (0.944) for maximum load measurement. Inter- (0.021) and intraobserver (0.774) agreement for stiffness was lower. Plastic deformation and rigor mortis were excluded. The animal model demonstrates reliable and in vivo-like measurements of tendon mobility. The SEAG is a reliable tool for tendon mobility assessment.

How Much Will High Tension Adversely Affect Rotator Cuff Repair Integrity?

PURPOSE

To suggest a cutoff value of tension related to retear of a repaired chronically contracted rotator cuff and to analyze the correlation between predictive factors and integrity of repair in large to massive contracted rotator cuff tears (RCTs).

METHODS

We analyzed arthroscopic rotator cuff repairs for large to massive (>3 cm) contracted RCTs, not amenable to complete repair by standard means with meticulous release, with a minimum of 1 year follow-up. An intraoperative procedure was designed for the estimation of repair tension using a tensiometer. Clinical and radiological findings were compared between the healed group and the retear group, and magnetic resonance imaging was performed ∼1 year postoperatively for the evaluation of integrity of the repair site. The receiver operating characteristic curve was used to identify the cutoff value of the independent factors. Factors affecting postoperative retear were examined with multivariate analysis.

RESULTS

Fifty patients were enrolled in this study and divided into the healed group (31 patients) and the retear group (19 patients) according to the follow-up magnetic resonance imaging findings. Significant results showed that tension (5.13 < 95% confidence interval [CI] < 58.15, P < .001) and acromiohumeral interval (AHI) (1.13 < 95% CI < 33.10, P = .013) were important factors for the integrity of rotator cuff repair. The cutoff value of tension was 35 N, and an AHI <6.6 mm may also be considered a predictor of retear. An occupation ratio of the tension >35 N was the strongest predictor of retear, with an area under the curve of 0.799, sensitivity of 84.2%, and specificity of 67.7% (accuracy = 76.0%).

CONCLUSIONS

The integrity of a large to massive rotator cuff repair is strongly related to the tension to reach the articular margin of the footprint and AHI. We found that the possibility of retear increases when tension ≥35 N is required. AHI <6.6 mm may also be considered a predictor of retear.

LEVEL OF EVIDENCE

Level III, retrospective cohort design.

Supraspinatus muscle location changes after arthroscopic rotator cuff repair: a potential source of preoperatively predicting tear patterns

Purpose

When repairing retracted rotator cuff tears, the tear pattern (eg, crescent-shaped, L-shaped) is best determined intraoperatively by evaluating the mobility of the tendon in multiple directions. The purpose of our study was to evaluate the location of the supraspinatus (SSP) muscle belly on magnetic resonance imaging (MRI) in patients undergoing arthroscopic repair of retracted rotator cuff tears. We hypothesized that the location of the rotator cuff muscle would move after tendon repair, and that the perioperative change in muscle position would correlate with the tear pattern.

Methods

A series of primary arthroscopic repairs for rotator cuff tears with >3 cm of medial retraction from 2015 to 2016 was reviewed. MRIs were performed preoperatively and within 10 days postoperatively. The SSP muscle was assessed on sagittal MRI and evaluated for the “occupation ratio”, “tangent sign”, and the “location index” proposed in this study. Pre and postoperative MRIs were compared, and correlated with intraoperatively determined tear patterns. Fifty shoulders without rotator cuff pathology were also assessed for the “location index” as control.

Results

Fifty-nine shoulders (mean age 65.0 years) were included, among which five reverse L-shaped tears were identified. The occupation ratio and tangent sign improved postoperatively. Preoperatively, in the majority of tears, the SSP muscle was located more posteriorly in the SSP fossa, compared to the control group, and shifted anteriorly after repair. However, in reverse L-shaped tears the SSP muscle was located more centrally in the fossa, and shifted posteriorly following repair.

Conclusion

Rotator cuff tearing and arthroscopic rotator cuff repair change the location of the SSP muscle. Although repair usually results in shifting of the muscle belly from posterior to anterior, reverse L-shaped tears demonstrated an opposite pattern. The location of the SSP muscle belly may be useful in predicting tear patterns of retracted rotator cuff tears.

Level of evidence

Level IV (case series).

A novel remaining tendon preserving repair technique leads to improved outcomes in special rotator cuff tear patterns

INTRODUCTION

The purpose of this study was to identify the tear pattern that could be anatomically repaired by preserving the remaining tendon on footprint and evaluate clinical outcomes of patients who underwent remaining tendon preserving cuff repair.

MATERIALS AND METHODS

Of 523 patients with full-thickness rotator cuff tears who underwent arthroscopic repair, 41 (7.8%) patients had repairable rotator cuff tear while preserving the remaining tendon. Among them, 31 patients were followed-up for more than 2 years, including 26 patients with posterior L-shaped tear and 5 patients with transtendinous tear patterns. Clinical outcomes were evaluated using ASES and Constant score, SANE score for patient satisfaction, and VAS for pain. MRI was taken for tendon integrity 6 months postoperatively.

RESULTS

Of the 31 patients, 11 (35.5%) had previous injury history before rotator cuff tear, including 7 (26.9%) of the 26 patients with posterior L-shaped tear and 4 (80%) of the 5 patients with transtendinous tear. The average size of preoperative cuff tear was 17.8 ± 6.8 mm in anterior-to-posterior direction and 15.2 ± 5.1 mm in medial-to-lateral direction. ASES and Constant score, SANE score, and VAS for pain were significantly (p < 0.001) improved after remaining tendon preserving rotator cuff repair. Rotator cuff tendons of 22(84.6%) patients with posterior L-shaped tear and 4(80%) patients with transtendinous tear patterns were healed.

CONCLUSION

Patients who underwent rotator cuff repair with preservation of the remaining tendon on the footprint obtained satisfactory functional outcomes. Rotator cuff tears in patients who had posterior L-shaped tear extending between supraspinatus and infraspinatus tendons or transtendinous tear pattern with substantial remaining tendon could be repaired using remaining tendon preserving repair technique. Anatomic reduction of torn cuff tendon without undue tension could be achieved using the remaining tendon preserving repair technique.