Quantitative assessment of the muscles of the rotator cuff with magnetic resonance imaging

Supraspinatus atrophy as a predictor of rotator cuff tear size: an MRI study utilizing the tangent sign

HYPOTHESIS

We hypothesize that the degree of supraspinatus atrophy, as assessed with the tangent sign will significantly correlate with increasing rotator cuff tear size.

METHODS

A retrospective review was performed assessing presence of muscle atrophy using the tangent sign, fatty atrophy based on Goutallier classification, and size of rotator cuff tear in 34 patients. A correlation analysis was performed.

RESULTS

All agreement measures among both evaluators were statistically significant (P < .05). Agreement among the 2 physicians for the tangent sign was consider almost perfect k = 87.2 (95%CI = 51.7, 87.2). Weighted kappa agreement using the Goutallier sign was 75.1 (95%CI = 58.7, 91.4), suggesting substantial agreement. The relationship between the positive tangent sign and coded tear grade was very good with a correlation of R = .84 and R = .87, respectively, showing a strong correlation between the presence of a tangent sign and a larger rotator cuff tear. A strong relationship was also found when comparing the tangent sign to a Goutallier's classification of 2 or greater with a correlation of R = .92 and R = .94 for the 2 physicians. The lowest correlation was found between the Goutallier sign and tear grade from both physicians. All of these findings were statistically significant (P < .05).

CONCLUSION

The tangent sign shows good interobserver reliability and is easily performed to measure rotator cuff atrophy and a positive tangent sign shows an excellent correlation with the size of the rotator cuff tear and may be predictive of the ability of the cuff to be primarily repaired.

Reverse shoulder arthroplasty combined with a latissimus dorsi and teres major transfer for a deficit of both active elevation and external rotation. Results of 15 cases with a minimum of 2-year follow-up

PURPOSE

Our aim was to assess the clinical and radiological outcomes of reverse shoulder replacements performed in association with a latissimus dorsi and teres major tendon transfer in cases of irreparable posterosuperior cuff tears including the teres minor tendon. Our hypothesis was that the tendon transfers would improve the clinical results of arthroplasty by restoring active external rotation.

METHODS

Fifteen procedures in 14 patients were performed through a single deltopectoral approach. Both tendons were fixed to the proximal anterolateral aspect of the humeral metaphysis. Mean age at the time of surgery was 67.5 years (range 53 to 82 years). All had severe cuff tear arthropathy (Hamada stage 3 or 4) and severe atrophy or fatty infiltration of the infraspinatus and teres minor on preoperative MRI or CT-scan (Goutallier stage 3 or 4). Preoperative and postoperative functions were assessed by Constant score. Satisfaction was assessed by the Simple Shoulder Test (SST). At follow up, radiographs were examined for radiolucent lines, osteolysis and scapular notching.

RESULTS

The average follow-up after surgery was 33.2 months (range 24 to 60 months). The mean absolute Constant score improved significantly (P=10(-5)) from 23.7±11.5 preoperatively to 61.1±11.9 postoperatively. Forward flexion and external rotation with the arm at the side improved significantly, respectively from 64.7±35.6° preoperatively to 126±34.4° postoperatively (P<10(-5)) and from -8.7±21.3° to 27.3±12.2° (P<0.0005). Internal rotation was not affected. The mean SST improved from 1.9±1.6 points preoperatively to 7.6±1.8 points postoperatively (P<0.0005). Twelve patients were very satisfied or satisfied (including one with a bilateral procedure) and 2 were unsatisfied with the final result. At final follow-up, radiographs showed no radiolucent lines around the implants nor scapular notching.

CONCLUSION

The combined procedure helped restoration of active elevation and external rotation in cases of massive cuff tear including the teres minor tendon.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Changes in appearance of fatty infiltration and muscle atrophy of rotator cuff muscles on magnetic resonance imaging after rotator cuff repair: establishing new time-zero traits

PURPOSE

To investigate whether and how arthroscopic rotator cuff repair changes the appearance of fatty infiltration and muscle atrophy as shown on magnetic resonance imaging (MRI) by comparing measurements taken before and immediately after surgery.

METHODS

The first study determined appropriate measurements of fatty infiltration and muscle atrophy, and the second study assessed immediate postoperative changes caused by surgery per se. Forty-two patients who underwent arthroscopic shoulder surgery for reasons other than rotator cuff repair were included in the first study, and 101 patients who underwent arthroscopic rotator cuff repair were included in the second study. MRI was undertaken preoperatively and 3 days after surgery. Fatty infiltration was evaluated with the Goutallier grade and by measuring signal intensities of rotator cuff muscles, and muscle atrophy was assessed with the tangent sign, occupation ratio, and cross-sectional areas of muscles.

RESULTS

In the first study, only the cross-sectional area of the subscapularis significantly changed after surgery and was excluded in the second study. In the second study, fatty infiltration seemingly improved by at least 1 grade in 50.0%, 75.0%, and 95.8% of patients with Goutallier grade 2, 3, and 4, respectively, in the supraspinatus (P < .001) and in 28.6%, 57.1%, and 66.7%, respectively, in the infraspinatus (P < .001). Muscle atrophy of the supraspinatus changed by at least 1 grade in 93.6% of patients with a grade 2 tangent sign and 100.0% with a grade 3 tangent sign, as well as 84.0% of patients with a grade 3 occupation ratio; cross-sectional areas of the supraspinatus and infraspinatus significantly increased by 21.6% and 7.0%, respectively (all P < .001).

CONCLUSIONS

This study showed that arthroscopic rotator cuff repair changed the appearance of both fatty infiltration and muscle atrophy of the supraspinatus and infraspinatus on MRI. We suggest that these changes be considered when one is assessing rotator cuff muscle changes by comparing the appearance on MRI before surgery with that at a certain time after surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic repair of subscapularis tears: preliminary data from a prospective multicentre study

BACKGROUND

Until the introduction of arthroscopic-assisted surgery for rotator cuff repair, the frequency of subscapularis tears was underestimated. These tears remain challenging to treat even with arthroscopy. The absence of a specific classification system has hampered communication about the treatment and outcomes of the various types of subscapularis tears. The objective of this prospective multicentre study was to validate the relevance of arthroscopic subscapularis tendon repair based on an assessment of short-term outcomes according to the initial extent of the anatomic lesions.

METHODS

A prospective multicentre study sponsored by the French Society for Arthroscopy was conducted from March 2010 to January 2011 in 208 patients with subscapularis lesions that were either isolated or associated with limited anterosuperior tears. The Constant and UCLA scores were used to assess clinical outcomes. Anatomic and prognostic results were evaluated based on the physical examination, preoperative and postoperative imaging study findings, and anatomic lesions. Clinical data were available for 103 patients after at least 1 year of follow-up and radiological data for 129 patients after at least 6 months.

RESULTS

The preliminary clinical results in 103 patients with at least 1 year of follow-up showed overall statistically significant improvements in the Constant and UCLA scores, with resolution of the clinical manifestations. The degree of improvement seemed to increase over time. The clinical results varied significantly across patient groups based on a classification system distinguishing four lesion types. Postoperative imaging studies to assess the anatomic results in all patients with at least 6 months of follow-up (n=129) showed tendon healing in 92% of cases but also indicated muscle wasting of the upper subscapularis muscle in 18.6% of cases and increased fatty degeneration of the muscle belly.

DISCUSSION

Our study confirms the good clinical and radiological results reported in the literature. Our classification system distinguishing four lesion patterns was applicable during the imaging workup. The main finding from this classification system was the difference in results between Type 2 and Type 3 lesions. The trend towards improvements over time requires confirmation by longer-term studies, which will also have to establish that the increased wasting of the upper subscapularis muscle and fatty degeneration of the muscle belly have no adverse effects.

Non-contrast magnetic resonance imaging for diagnosing shoulder injuries

PURPOSE

To compare preoperative non-contrast magnetic resonance imaging (MRI) with arthroscopy findings in diagnosing labral and rotator cuff tears.

METHODS

86 men and 60 women aged 21 to 70 (mean, 52) years underwent non-contrast MRI before arthroscopic operations on the glenohumeral joint. Slices were made in a transverse, parasagittal, and paracoronar orientation. The sequences used were T2- and proton-weighted for paracoronar imaging, T1- and T2-weighted for transverse and parasagittal imaging, and T2-weigthed sequences with fat suppression and short tau inversion recovery sequences. MRI was evaluated with the surgeon to eliminate interobserver bias. Arthroscopic surgery was performed by a single surgeon. If a labral or rotator cuff tear was found, surgery was performed using corkscrew anchors.

RESULTS

For full thickness rotator cuff tears, MRI and arthroscopy detected them in 76 and 82 patients, respectively. One such tear found by MRI could not be confirmed by arthroscopy. MRI missed 4 subscapularis and 3 supraspinatus tears. The sensitivity and specificity of MRI in diagnosing full thickness rotator cuff tears were 0.90 and 0.91, respectively. For labral tears, MRI and arthroscopy detected them in 16 and 31 patients, respectively. One anterior labral tear detected by MRI could not be verified by arthroscopy. All 16 labral tears detected by MRI were Bankart type-I tears (of the anterior glenoid) except for one superior labral tear from anterior to posterior (SLAP tear). All 13 SLAP tears (10 type 2 and 3 type 3) except for one could be found by arthroscopy only. The sensitivity and specificity of MRI in diagnosing labral tears were 0.52 and 0.89, respectively.

CONCLUSION

Non-contrast MRI is reliable only for diagnosing full thickness rotator cuff tears and anterior labral tears. Direct or indirect contrast enhancement is recommended for more differentiation. Special scan orientation is necessary for SLAP tears.

Association between acromial index and outcomes following arthroscopic repair of full-thickness rotator cuff tears

BACKGROUND

The purposes of this study were to evaluate the association between the acromial index and full-thickness rotator cuffs and to determine if the size of the acromial index was associated with outcomes in a cohort of patients who had had arthroscopic repair of full-thickness rotator cuff tears.

METHODS

The acromial index was calculated for three groups by individual researchers: 115 patients (120 shoulders) who had arthroscopically repaired full-thickness rotator cuff tears without osteoarthritis (Group I); sixty-four patients (sixty-eight shoulders) who had intact rotator cuffs with osteoarthritis (Group II); and twenty-one patients (twenty-one shoulders) who had intact rotator cuffs, without osteoarthritis, and were managed for other pathology (Group III). The acromial index is the distance between the glenoid plane and the lateral border of the acromion divided by the distance between the glenoid plane and the lateral aspect of the humeral head. Ninety-two patients (ninety-three shoulders) from Group I met inclusion criteria for subjective follow-up. Minimum two-year subjective data were obtained on 86% (seventy-nine patients [eighty shoulders]) of these ninety-two patients to determine the association of the acromial index on surgical outcomes. Surgical factors were also analyzed. Significance was set at p < 0.05.

RESULTS

The acromial index demonstrated high intraobserver agreement (kappa, 0.960; 95% confidence interval, 0.940 to 0.984) and high interobserver agreement (kappa, 0.960; 95% confidence interval, 0.922 to 0.979). The mean acromial index (and standard deviation) was 0.687 ± 0.08 for Group I, 0.685 ± 0.11 for Group II, and 0.694 ± 0.07 for Group III. No significant differences were found. At an average duration of follow-up of 3.0 years (range, 2.0 to 5.4 years), the mean American Shoulder and Elbow Surgeons scores improved from 59 to 93 points (p = 0.001) in the seventy-nine patients from Group I who had minimum two-year duration of subjective follow-up. The mean postoperative scores were 10.4 points (range, 0 to 54.5 points) for the Quick Disabilities of the Arm, Shoulder and Hand Outcome Measure and 9.2 points (on a scale of 1 to 10 points) for patient satisfaction. When the patients with a large acromial index (>0.682) were compared with those with a small acromial index (≤ 0.682), the patients in the former group had a greater likelihood of having a tear involving two or more rotator cuff tendons (p = 0.017), required more anchors to achieve repair (p = 0.007), had slightly lower patient satisfaction scores (mean, 8.9 compared with 9.5 points; p = 0.055) and Short Form-12 Physical Component Summary scores (mean, 49.1 compared with 55.2 points; p = 0.04), and had higher Quick Disabilities of the Arm, Shoulder and Hand scores (mean, 12.9 compared with 7.4 points; p = 0.042).

CONCLUSIONS

An association between the size of the acromial index and that of full-thickness rotator cuff tears was not confirmed; however, a larger acromial index was associated with an increased number of tendons torn and anchors used for repair. In addition, patients with a larger acromial index had more disability as recorded by the Quick Disabilities of the Arm, Shoulder and Hand Outcome Measure and poorer physical health as measured by the Short Form-12 Physical Component Summary score.

Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft

PURPOSE

This study presents a retrospective case series of the clinical and structural outcomes (1.5 T MRI) of arthroscopic rotator cuff repair with acellular human dermal graft reinforcement performed by a single surgeon in patients with large, massive, and previously repaired rotator cuff tears.

MATERIALS AND METHODS

Fourteen patients with mean anterior to posterior tear size 3.87 ± 0.99 cm (median 4 cm, range 2.5-6 cm) were enrolled in the study and were evaluated for structural integrity using a high-field (1.5 T) MRI at an average of 16.8 months after surgery. The Constant-Murley scores, the Flexilevel Scale of Shoulder Function (Flex SF), scapular plane abduction, and strength were analyzed.

RESULTS

MRI results showed that the rotator cuff repair was intact in 85.7% (12/14) of the patients studied. Two patients had a Sugaya Type IV recurrent tear (2 of 14; 14.3%), which were both less than 1 cm. The Constant score increased from a preoperative mean of 49.72 (range 13-74) to a postoperative mean of 81.07 (range 45-92) (P value = 0.009). Flexilevel Scale of Shoulder Function (Flex SF) Score normalized to a 100-point scale improved from a preoperative mean of 53.69 to a postoperative mean of 79.71 (P value = 0.003). The Pain Score improved from a preoperative mean of 7.73 to a postoperative mean of 13.57 (P value = 0.008). Scapular plane abduction improved from a preoperative mean of 113.64° to a postoperative mean of 166.43° (P value = 0.010). The strength subset score improved from a preoperative mean of 1.73 kg to a postoperative mean of 7.52 kg (P value = 0.006).

CONCLUSIONS

This study presents a safe and effective technique that may help improve the healing rates of large, massive, and revision rotator cuff tears with the use of an acellular human dermal allograft. This technique demonstrated favorable structural healing rates and statistically improved functional outcomes in the near term.

LEVEL OF EVIDENCE

4. Retrospective case series.

Preoperative agreement on the geometric classification and 2-dimensional measurement of rotator cuff tears based on magnetic resonance arthrography

PURPOSE

To determine the intraobserver and interobserver agreement on the geometric classification and 2-dimensional measurements of rotator cuff tears based on magnetic resonance arthrography.

METHODS

We retrospectively reviewed preoperative magnetic resonance arthrograms of 73 consecutive patients who were surgically treated for their full-thickness rotator cuff tears. The images were blinded and evaluated by 2 orthopaedic shoulder surgeons and 2 musculoskeletal radiologists using the geometric classification of rotator cuff tears (type 1, crescent-shaped tear; type 2, longitudinal U- or L-shaped tear; type 3a, massive tear measuring between 20 and 30 mm; and type 3b, massive contracted tear measuring >30 mm) and measuring the sagittal/coronal dimensions of the tear. Review was performed twice with an interval of at least 8 weeks. Agreement was calculated using the linear weighted κ coefficient and the intraclass correlation coefficient (ICC).

RESULTS

The intraobserver agreement was excellent for both the geometric classification and the sagittal/coronal dimension measurement (κ, 0.81 to 0.92; ICC, 0.84 to 0.98). The ICC for the interobserver agreement was excellent for all sagittal and coronal dimension measurements (ICC, 0.95 to 0.97). The interobserver agreement for the geometric classification was good for the orthopaedic surgeons (κ, 0.75 for round 1 and 0.73 for round 2). The interobserver agreement for the radiologists was excellent in observation round 1 (κ, 0.82) and good in observation round 2 (κ, 0.71). The interobserver agreement between orthopaedic surgeons and radiologists was found to be moderate to good (κ, 0.52 to 0.66). The Fleiss κ was 0.66 for round 1 and 0.62 for round 2.

CONCLUSIONS

The geometric classification and the 2-dimensional measurement of rotator cuff tears using magnetic resonance arthrography have good to excellent intraobserver agreement and moderate to good interobserver agreement among experienced observers.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients without consistently applied gold standard.

Does open repair of anterosuperior rotator cuff tear prevent muscular atrophy and fatty infiltration?

BACKGROUND

Repair of cuff tears involving rotator interval reportedly improves function. However, it is unclear whether successful repair prevents shoulder degenerative changes.

QUESTIONS/PURPOSES

Therefore, we (1) documented the minimal 4-year function of patients who underwent open surgical repair for rotator interval tears; (2) evaluated repaired tendon healing with postoperative MRI; and (3) sought to determine the influence of tendon healing on muscular and glenohumeral joint changes.

METHODS

We retrospectively analyzed 22 patients (23 shoulders) treated by open transosseous reinsertion of supraspinatus and subscapularis tendons. The mean age of the patients was 53 years (range, 37-64 years). The tear was traumatic in four cases. Repair healing and muscular changes were assessed using MRI. The minimum followup was 46 months (mean, 75 months; range, 46-103 months).

RESULTS

We observed an improvement in the absolute Constant-Murley score from 63 points preoperatively to 76 points postoperatively. With the last followup MRI, the supraspinatus tendon repair had failed in two of the 23 shoulders, whereas the subscapularis tendon repair had healed in all cases. Once healing of the repaired tendon occurred, supraspinatus muscle atrophy never worsened. However, on MRI fatty infiltration of the rotator cuff muscles increased despite successful tendon repair. Glenohumeral arthritis remained stable. Postoperative abduction and internal rotation strengths were better when the standardized supraspinatus muscle area was greater than 0.5 at the final evaluation.

CONCLUSION

Durable functional improvement and limited degenerative articular and muscular changes can be expected in most patients 4 to 10 years after open repair of anterosuperior cuff tears provided that healing of the cuff is obtained.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Retraction of supraspinatus muscle and tendon as predictors of success of rotator cuff repair

BACKGROUND

The structural failure rate of rotator cuff repair can exceed 50%. Important predictors for repair failure are preoperative fatty muscle infiltration and myotendinous retraction.

PURPOSE

To quantitatively assess the prognostic value of preoperative retraction of both the supraspinatus muscle and tendon for the outcome of supraspinatus repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

In 33 shoulders with complete supraspinatus tendon ruptures subjected to arthroscopic repair, magnetic resonance imaging (MRI) scans taken preoperatively and after a mean follow-up of 24 months were studied. The exact position of the lateral extension of the supraspinatus muscle and of the tendon end was evaluated and correlated with the preoperative stage of fatty infiltration (Goutallier) and the failure rate of tendon repair.

RESULTS

The mean lengthening of the muscle and tendon end was -3 mm and 4 mm in the failed repairs (n = 19) and 14 mm and 8 mm in the successful repairs (n = 14). If the supraspinatus had preoperative Goutallier stages 2 to 3 and a tendon length of less than 15 mm, the failure rate was 92%, but if the tendon length was greater than 15 mm, the failure rate was only 33%. With Goutallier stages 0 to 1, the corresponding failure rates were 57% and 25%, respectively.

CONCLUSION

Rotator cuff repair lengthens the tendon, even if the repair fails. The possibility to lengthen the myotendinous unit is related to the preoperative length of the tendon. The combination of Goutallier grading and preoperative tendon length appears to be a more powerful predictor for the reparability of a tendon tear than Goutallier grading alone.

Magnetic resonance imaging identification of rotator cuff retears after repair: interobserver and intraobserver agreement

BACKGROUND

Magnetic resonance imaging (MRI) is the most commonly used imaging modality to assess the rotator cuff. Currently, there are a limited number of studies assessing the interobserver and intraobserver reliability of MRI after rotator cuff repair.

HYPOTHESIS

Fellowship-trained orthopaedic shoulder surgeons will have good inter- and intraobserver agreement with regard to features of the repaired rotator cuff (repair integrity, fat content, muscle volume, number of tendons involved, tear size, and retract) on MRI.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Seven fellowship-trained orthopaedic shoulder surgeons reviewed 31 MRI scans from 31 shoulders from patients who had previous rotator cuff repair. The scans were evaluated for the following characteristics: rotator cuff repair status (full-thickness retear vs intact repair), tear location, tendon thickness, fatty infiltration, atrophy, number of tendons involved in retear, tendon retraction, status of the long head of the biceps tendon, and bone marrow edema in the humeral head. Surgeons were asked to review images at 2 separate time points approximately 9 months apart and complete an evaluation form for each scan at each time point. Multirater kappa (κ) statistics were used to assess inter- and intraobserver reliability.

RESULTS

The interobserver agreement was highest (80%, κ = 0.60) for identifying full-thickness retears, tendon retear retraction (64%, κ = 0.45), and cysts in the greater tuberosity (72%, κ = 0.43). All other variables were found to have fair to poor agreement. The worst interobserver agreement was associated with identifying rotator cuff footprint coverage (47%, κ = -0.21) and tendon signal intensity (29%, κ = -0.01). The mean intraobserver reproducibility was also highest (77%-90%, κ = 0.71) for full-thickness retears, quality of the supraspinatus (47%-83%, κ = 0.52), tears of the long head of the biceps tendon (58%-94%, κ = 0.49), presence of bone marrow edema in the humeral head (63%-87%, κ = 0.48), cysts in the greater tuberosity (70%-83%, κ = 0.47), signal in the long head of the biceps tendon (60%-80%, κ = 0.43), and quality of the infraspinatus (37-90%, κ = 0.43). The worst intraobserver reproducibility was found in identification of the location of bone marrow edema (22%-83%, κ = -0.03).

CONCLUSION

The results of this study indicate that there is substantial variability when evaluating MRI scans after rotator cuff repair. Intact rotator cuff repairs or full-thickness retears can be identified with moderate reliability. These findings indicate that additional imaging modalities may be needed for accurate assessment of the repaired rotator cuff.

Serial structural and functional assessments of rotator cuff repairs: do they differ at 6 and 19 months postoperatively?

BACKGROUND

Some studies have shown that rotator cuff tendon (RCT) retears occur early after surgery and ultimate failure strength is reached at between 3 and 6 months. However, few clinical studies have been reported to support their theory. The purpose of this study was to determine whether the RCT integrity after repair showed any difference at 6 months and at 19 months postoperatively.

METHODS

Thirty-one patients who underwent complete repair for full-thickness RCT tears that were medium-sized tears or larger and had 2 postoperative follow-up magnetic resonance imaging (MRI) scans were included in this study. Retear, fatty degeneration, and muscle atrophy were evaluated during the first and second MRI sessions. Clinical assessment was performed by use of the American Shoulder and Elbow Surgeons score, Constant score, and pain visual analog scale preoperatively and at the time of the first and second MRI scans.

RESULTS

The mean time for the two consecutive MRI scans was 5.9 months (range, 3.1-8.3 months) and 19.7 months (range, 10.1-24.3 months). On the first MRI scans, 24 patients had no retear, 5 had partial retears, and 2 had full-thickness retears. In terms of rotator cuff retears, the 2 sets of MRI scans showed exactly the same statuses. The only statistically significant improvement was a reduction in tendinosis on the second MRI scans. In addition, significant improvements in clinical status were observed between the 2 periods.

CONCLUSION

Our study shows that the structural status of RCTs after arthroscopic repair can be assessed at 6 months after surgery. Furthermore, although functional status improved with time after 6 months, the structural status of repaired cuffs remained unchanged.

Muscular atrophy of the lower leg in unilateral post traumatic osteoarthritis of the ankle joint

PURPOSE

Muscle atrophy is a commonly encountered problem in osteoarthritis (OA). The aim of this study was to estimate the amount of muscle atrophy and fatty degeneration of the lower leg muscles related to ankle OA by magnetic resonance imaging (MRI).

METHODS

Twenty-one patients with unilateral ankle OA were included in this cohort study. Calf circumference of the affected and healthy lower leg was documented. The degree of OA was classified in conventional radiographs. The cross-sectional areas and fatty degeneration of the muscles of the lower leg were measured in bilateral MRI.

RESULTS

We found a significantly reduced calf circumference of the affected vs. healthy leg (p = 0.016). MRI showed a significantly lower cross-sectional area of the entire lower leg musculature in OA (p = 0.013). Sub-analysis of muscle groups revealed that only the M. soleus had a significant cross-sectional area decrease (p < 0.01). All muscles showed a significant fatty degeneration (p < 0.01).

CONCLUSIONS

We conclude that unilateral ankle joint osteoarthritis leads to an overall lower leg muscle atrophy, but significant atrophy of the M. soleus. All muscles of the affected leg undergo a fatty degeneration.

Diagnostic performance and reliability of ultrasonography for fatty degeneration of the rotator cuff muscles

BACKGROUND

Diagnostic evaluation of rotator cuff muscle quality is important to determine indications for potential operative repair. Ultrasonography has developed into an accepted and useful tool for evaluating rotator cuff tendon tears; however, its use for evaluating rotator muscle quality has not been well established. The purpose of this study was to investigate the diagnostic performance and observer reliability of ultrasonography in grading fatty degeneration of the posterior and superior rotator cuff muscles.

METHODS

The supraspinatus, infraspinatus, and teres minor muscles were prospectively evaluated with magnetic resonance imaging (MRI) and ultrasonography in eighty patients with shoulder pain. The degree of fatty degeneration on MRI was graded by four independent raters on the basis of the modified Goutallier grading system. Ultrasonographic evaluation of fatty degeneration was performed by one of three radiologists with use of a three-point scale. The two scoring systems were compared to determine the diagnostic performance of ultrasonography. The interobserver and intraobserver reliability of MRI grading by the four raters were determined. The interobserver reliability of ultrasonography among the three radiologists was determined in a separate group of thirty study subjects. The weighted Cohen kappa, percentage agreement, sensitivity, and specificity were calculated.

RESULTS

The accuracy of ultrasonography for the detection of fatty degeneration, as assessed on the basis of the percentage agreement with MRI, was 92.5% for the supraspinatus and infraspinatus muscles and 87.5% for the teres minor. The sensitivity was 84.6% for the supraspinatus, 95.6% for the infraspinatus, and 87.5% for the teres minor. The specificity was 96.3% for the supraspinatus, 91.2% for the infraspinatus, and 87.5% for the teres minor. The agreement between MRI and ultrasonography was substantial for the supraspinatus and infraspinatus (kappa = 0.78 and 0.71, respectively) and moderate for the teres minor (kappa = 0.47). The interobserver reliability for MRI was substantial for the supraspinatus and infraspinatus (kappa = 0.76 and 0.77, respectively) and moderate for the teres minor (kappa = 0.59). For ultrasonography, the interobserver reliability was substantial for all three muscles (kappa = 0.71 for the supraspinatus, 0.65 for the infraspinatus, and 0.72 for the teres minor).

CONCLUSIONS

The diagnostic performance of ultrasonography in identifying and grading fatty degeneration of the rotator cuff muscles was comparable with that of MRI. Ultrasonography can be used as the primary diagnostic imaging modality for fatty changes in rotator cuff muscles.

A comparison of the degree of retraction of full-thickness supraspinatus tears with the Goutallier grading system

BACKGROUND

Tears of the supraspinatus are common and incompletely understood. The degree of fatty infiltration into the muscle is perceived to be a determining factor of successful surgical repair and postoperative function. It is the hypothesis of this study that the degree of central tendon retraction (CTR) as seen on magnetic resonance imaging corresponds to the amount of fatty infiltration classified according to the Goutallier grading system.

MATERIALS AND METHODS

Magnetic resonance imaging scans of the supraspinatus were reviewed in 2 identifiable groups: 143 scans with no tear (NT) and 148 scans with a full-thickness tear (FTT) and CTR. The degree of CTR and the corresponding Goutallier grade were measured. The difference in Goutallier grade between the NT and FTT groups was measured with the Mann-Whitney test. The relationship between Goutallier grade and increasing amount of CTR was described by use of Spearman rank correlation. Studying the difference between the Goutallier grades and CTR was achieved by use of Mann-Whitney tests.

RESULTS

Of NT scans, 100% showed Goutallier grade 0 or 1. Among FTT scans, 2 showed grade 0, 21 showed grade 1, 35 showed grade 2, 14 showed grade 3, and 76 showed grade 4. The difference was statistically significant (P < .001) between the Goutallier grade 3 and 4 scans, and the degree of Goutallier grade increased with increasing CTR (P < .001).

CONCLUSION

Fatty infiltration can be directly linked to CTR and, as such, may help to determine surgical intervention between groups.

Evolution of nonoperatively treated symptomatic isolated full-thickness supraspinatus tears

BACKGROUND

The natural history of small, symptomatic rotator cuff tears is currently unclear. The purpose of the present study was to assess the clinical and structural outcomes for a consecutive series of patients with symptomatic, isolated full-thickness supraspinatus tears who had been offered rotator cuff repair but declined operative treatment.

METHODS

In the study period, twenty-four patients with isolated full-thickness supraspinatus tears that had been diagnosed by means of magnetic resonance arthrography were offered rotator cuff repair and elected nonoperative treatment. The twenty men and four women had an average age of fifty-two years at the time of diagnosis. At a median of forty-two months after the diagnosis, all patients were reexamined clinically according to the Constant and Murley scoring system and all shoulders underwent standard magnetic resonance imaging.

RESULTS

At the time of follow-up, the mean subjective shoulder score was 74% of that for a normal shoulder and the mean Constant score was 75 points (relative Constant score, 86%). The mean rotator cuff tear size did not change significantly over time (95% confidence interval, 0.51 to 1.12). In two shoulders, the tear was no longer detectable on magnetic resonance imaging, in nine shoulders the tear was smaller than it had been at the time of the initial diagnosis, in nine patients the tear had not changed, and in six patients the tear had increased in size. There was a slight but significant progression of fatty muscle infiltration of the supraspinatus, but no patient had fatty infiltration beyond stage 2 at the time of the latest follow-up (95% confidence interval, 0% to 14%).

CONCLUSIONS

In a consecutive series of patients who had been offered repair of an isolated, symptomatic supraspinatus tear, the refusal of operative treatment resulted in surprisingly high clinical patient satisfaction and no increase of the average size of the rotator cuff tear 3.5 years after the recommendation of operative repair. This study confirms that the size of small rotator cuff tears does not invariably increase over a limited period of time. Distinguishing tears that will increase in size from those that will not needs further study.

Does arthroscopic rotator cuff repair actually heal? Anatomic evaluation with magnetic resonance arthrography at minimum 2 years follow-up

PURPOSE

The goal of this series was to evaluate the clinical and anatomical outcomes of all-arthroscopic rotator cuff tears repair at a mid-term follow-up, using MR arthrography in order to assess tendon-to-bone healing.

MATERIALS AND METHODS

This retrospective study included 29 patients (31 shoulders) presenting, according to Cofield classification, a small or moderate-sized supraspinatus full thickness tear with (7/31) or without (24/31) infraspinatus extension. The mean size of the tear was 2.64 ± 1.61 cm. The Constant score was used for pre- and postoperative clinical evaluation. All tendons were repaired under arthroscopic control. A single row technique was used. Biceps tenotomy and subacromial decompression were systematically performed. All patients operated arm were immobilized in a sling for 4 weeks and full activity was allowed at 6 months. At last follow-up, a rotator cuff MR arthrography was performed by an independent radiologist to evaluate the anatomical status of repair.

RESULTS

The mean follow-up was 49.4 ± 17.3 months. Sixteen patients (17 shoulders) had a rotator cuff MR arthrography. Mean Constant score at last follow-up was 82.3 ± 12.4, with a mean improvement of 24%. Eighty-eight percent of repairs (15/17) showed a small or a large leakage at the MR arthrography. There was no significant correlation between the clinical and anatomical outcomes.

CONCLUSION

The interest of this series is to show, at a mid-term follow-up and using an invasive imaging technique, the low rate of tendon-to-bone healing in arthroscopic rotator cuff repair but with a minimal influence on clinical outcome.

Quantitative analysis of muscle and tendon retraction in chronic rotator cuff tears

BACKGROUND

Musculotendinous retraction is a limiting factor for repair of long-standing rotator cuff tears. However, it is currently unknown to what extent the muscle and tendon contribute to the degree of total retraction. Further understanding of this may possibly influence the strategy of musculotendinous reconstruction.

PURPOSE

To analyze the contribution of muscle and tendon to the process of myotendinous retraction.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Magnetic resonance imaging of 130 shoulders with intact (n = 20) or completely torn supraspinatus tendons was analyzed. Fatty infiltration of the supraspinatus muscle was graded according to Goutallier stages. The degree of retraction of the tendon stump and of the musculotendinous junction was assessed.

RESULTS

There were 30 shoulders without evidence of supraspinatus fatty infiltration, 25 with stage 1, 23 with stage 2, 25 with stage 3, and 15 with stage 4 changes. The corresponding tear sizes (distance of tendon end from greater tuberosity) were 4, 21, 27, 37, and 41 mm; the distance of the myotendinous junction from the greater tuberosity was 22, 33, 39, 48, and 48 mm; and the length of the tendons (distance of tendon end to myotendinous junction) was 19, 13, 12, 11, and 8 mm, respectively. In Goutallier stage 3 and above, and in case of a positive tangent sign, the musculotendinous junction was, in 90% of the cases, retracted to or beyond the glenoid.

CONCLUSION

Musculotendinous retraction in chronic rotator cuff tears results mainly from shortening of the muscle fibers but in advanced stages results also from shortening of the tendon tissue itself. The present data demonstrate, for the first time, that the residual tendon stump in a tendon tear does not have the length of the original tendon and is further shortened over time. Therefore, direct anatomic tendon reinsertion will result in lengthening of the supraspinatus muscle greater than what it would have been before the tear.

Rotator cuff tears treated with a modified deltoid flap repair technique

BACKGROUND

Few options exist in the treatment of irreparable rotator cuff tears, especially in younger patients. The purpose of this study was to present our experience with deltoid flap repairs combined with acromion elevation osteotomy increasing the space for the flap.

METHODS

We retrospectively reviewed the outcome of 57 patients with a mean age of 60 years who had undergone the modified anterolateral deltoid flap technique for the treatment of large and massive rotator cuff tears. Follow-up was performed after a mean of 6 years.

RESULTS

At follow-up, 84% of patients considered the condition of their shoulder as better or much better compared with before surgery. The mean Constant score was 88% (range, 45-122). Before surgery, all shoulders were significantly painful. At latest follow-up, 91% of the patients had no or mild pain. Elevation of the arm above 90° was possible in 38 patients before surgery and in 53 patients at latest follow-up. Tears involving 3 tendons were associated with inferior results. Retears of the deltoid flap occurred in 8 patients (14%); 1 of them was successfully treated with a reverse total shoulder replacement, and 6 had a repair of the flap, with only 1 satisfactory outcome.

CONCLUSIONS

The modified deltoid flap yielded reliable pain relief and a high rate of patient satisfaction, as well as satisfactory function in the majority of the patients. Especially in younger patients, this technique might be considered a viable alternative for the treatment of irreparable rotator cuff tears.

Inter-rater agreement of the Goutallier, Patte, and Warner classification scores using preoperative magnetic resonance imaging in patients with rotator cuff tears

PURPOSE

The purpose of this study was to determine the interobserver reliability of 3 commonly used classification systems in describing preoperative magnetic resonance imaging (MRI) studies of patients undergoing surgery for full-thickness rotator cuff tears.

METHODS

Thirty-one patients who underwent arthroscopic rotator cuff repair and had preoperative MRI studies available were selected over a 2-year period. Three board-certified shoulder surgeons independently reviewed these images. Each was instructed in the published method for determining the Patte score on the T2 coronal images, supraspinatus and infraspinatus atrophy on the T1 sagittal images as described by Warner et al., and the Goutallier score of fatty infiltration of the supraspinatus on the T1 coronal/sagittal images. Statistical analysis was then performed to determine the interobserver agreement using the κ statistic, with the level of significance set a priori at P < .01.

RESULTS

None of the classification systems studied yielded excellent or high interobserver reliability. The strongest agreement was found with the Patte classification assessing tendon retraction in the frontal plane (κ = 0.58). The Goutallier classification, which grades fatty infiltration of the supraspinatus, showed moderate interobserver agreement (κ = 0.53) when dichotomized into none to mild (grades 0, 1, and 2) and moderate to severe (grades 3 and 4). Muscle atrophy of both the supraspinatus and infraspinatus yielded the worst interobserver reliability, with only 28% agreement.

CONCLUSIONS

The Goutallier, Patte, and Warner MRI classification systems for describing rotator cuff tears did not have high interobserver reliability among 3 experienced orthopaedic surgeons. Fatty infiltration of the supraspinatus and tendon retraction in the frontal planes showed only moderate reliability and moderate to high reliability, respectively. These findings have potential implications in the evaluation of the literature regarding the preoperative classification of rotator cuff tears and subsequent treatment algorithms.

LEVEL OF EVIDENCE

Level III, diagnostic agreement study with nonconsecutive patients.

Will preoperative atrophy and Fatty degeneration of the shoulder muscles improve after rotator cuff repair in patients with massive rotator cuff tears?

Recently, retear rate after repair for massive cuff tear have been improved through devised suture techniques. However, reported retear rate is relevant to preoperative atrophy and fatty degeneration. The purpose of this study was to investigate whether preoperative atrophy and fatty degeneration of rotator cuff muscles improve by successful repair. Twenty-four patients with massive rotator cuff tear were evaluated on the recovery of atrophy and fatty degeneration of supraspinatus and infraspinatus muscle after surgery. Atrophy was classified by the occupation ratio and fatty degeneration by modified Goutallier's classification. Both were assessed on magnetic resonance imaging (MRI) before and after the operation. When the cuff was well repaired, improvement of the atrophy and fatty degeneration were observed in a half and a one-fourth of the cases, respectively. In retear cases, however, atrophy and fatty degeneration became worse. Improvement of atrophy and fatty degeneration of the rotator cuff muscles may be expected in the cases with successful achievement of rotator cuff repair for large and massive tear.

Current imaging of the rotator cuff

Rotator cuff pathology is a common cause of shoulder pain, and imaging plays a major role in the management of shoulder problems. General radiography may be useful as an initial screening test particularly in trauma and arthritis. Musculoskeletal ultrasound and magnetic resonance imaging are the most suitable modalities for the investigation of the rotator cuff, having high sensitivities and specificities for full-thickness tears. Musculoskeletal ultrasound and magnetic resonance imaging are less accurate in the detection of partial-thickness tears with greater observer variability. This article reviews the normal and pathologic imaging features of the rotator cuff and highlights the potential usefulness and limitations of various imaging modalities in the assessment of the tendon and the potential impact of imaging findings on clinical patient care.

The effect of multiple channeling on the structural integrity of repaired rotator cuff

PURPOSE

The purpose of this study was to investigate the effect of adding multiple channeling of the greater tuberosity on the structural integrity of the repaired rotator cuff tendon.

METHODS

Fifty-six consecutive patients who underwent arthroscopic rotator cuff repair and postoperative computed tomography arthrography (CTA) were included in this study; 31 consecutive patients that underwent conventional repair and 25 subsequent patients that underwent conventional repair with multiple channeling. Using CTA, the repaired rotator cuff was evaluated as either intact, incomplete, or complete leakage at the insertion and in the tendon separately. The integrity type and overall integrity was then determined by the combination of the insertion and tendon grade. Factors affecting integrity were also evaluated.

RESULTS

At the insertion, multiple channeling significantly improved integrity; complete leakage in 35.5% in the conventional group and 4.0% in the multiple channeling group (P = 0.017). In the tendon, no significant difference was observed between the two groups. Integrity types were significantly different between the two groups (P = 0.009). For overall integrity, discontinuity was more frequently identified in the conventional group (35.5%) than in the multiple channeling group (16.0%), but it was not statistically significant. With regard to causes of discontinuity, all were due to retears in the conventional group, while 75% were due to new tears in the multiple channeling group (P = 0.009).

CONCLUSION

Multiple channeling is simple and easily performed without any special instrument and might augment the healing of repaired rotator cuff tendons. It could be a useful technique in rotator cuff repair helping healing.

Fat content of hip muscles: an anteroposterior gradient

BACKGROUND

Despite the importance of the hip muscles in protecting against hip fracture and in the outcome of hip arthroplasty, the variability in their fat content has not been previously studied. Our objectives were to evaluate the variability in the fat content of the hip muscles in a population without myopathy or a need for hip surgery with the use of computed tomography (CT), to study the relationship between hip muscle fat content and physical performance, and to identify medical conditions and lifestyle habits associated with an increase in hip muscle fat content.

METHODS

Ten normal subjects without a relevant medical history and ninety-nine consecutive nonsurgical patients without myopathy (age, twenty-one to ninety-four years) underwent a nonenhanced CT scan of the pelvis. Patients were asked to perform physical tests (six-meter walk, repeated chair stands, and Trendelenburg test), and their level of physical activity and medical history were recorded. Evaluation of the fat content of the hip muscles was based on the analysis of four reproducible and representative CT slices with use of custom software.

RESULTS

The fat content varied among the muscles, with an anteroposterior gradient from the hip flexors (mean, 2%) to the hip extensors (mean, 10%). This gradient increased after fifty years of age. Fat content also varied considerably among patients. Higher fat content was associated with poorer performance on physical tests, even after adjustment for the cross-sectional area of the muscle (p < 0.05). Higher fat content was also associated with greater age, higher body-mass index, and lower physical activity (p < 0.001).

CONCLUSIONS

The observed variability in the fat content of individuals without myopathy or a need for hip surgery should be useful for comparison with future studies of specific populations of patients, such as those with muscle weakness secondary to hip fracture or hip surgery. Simple lifestyle changes such as dietary restriction, increased physical activity, and vitamin D supplementation may decrease muscle fat content and improve physical performance in the elderly.

Soft-tissue changes in hip abductor muscles and tendons after total hip replacement: comparison between the direct anterior and the transgluteal approaches

The direct anterior approach in total hip replacement anatomically offers the chance to minimise soft-tissue trauma because an intermuscular and internervous plane is explored. This motivated us to abandon our previously used transgluteal approach and to adopt the direct anterior approach for total hip replacement. Using MRI, we performed a retrospective comparative study of the direct anterior approach with the transgluteal approach. There were 25 patients in each group. At one year post-operatively all the patients underwent MRI of their replaced hips. A radiologist graded the changes in the soft-tissue signals in the abductor muscles. The groups were similar in terms of age, gender, body mass index, complexity of the reconstruction and absence of symptoms. Detachment of the abductor insertion, partial tears and tendonitis of gluteus medius and minimus, the presence of peri-trochanteric bursal fluid and fatty atrophy of gluteus medius and minimus were significantly less pronounced and less frequent when the direct anterior approach was used. There was no significant difference in the findings regarding tensor fascia lata between the two approaches. We conclude that use of the direct anterior approach results in a better soft-tissue response as assessed by MRI after total hip replacement. However, the impact on outcome needs to be evaluated further.

Restoration of anterior-posterior rotator cuff force balance improves shoulder function in a rat model of chronic massive tears

The rotator cuff musculature imparts dynamic stability to the glenohumeral joint. In particular, the balance between the subscapularis anteriorly and the infraspinatus posteriorly, often referred to as the rotator cuff "force couple," is critical for concavity compression and concentric rotation of the humeral head. Restoration of this anterior-posterior force balance after chronic, massive rotator cuff tears may allow for deltoid compensation, but no in vivo studies have quantitatively demonstrated an improvement in shoulder function. Our goal was to determine if restoring this balance of forces improves shoulder function after two-tendon rotator cuff tears in a rat model. Forty-eight rats underwent detachment of the supraspinatus and infraspinatus. After four weeks, rats were randomly assigned to three groups: no repair, infraspinatus repair, and two-tendon repair. Quantitative ambulatory measures including medial/lateral forces, braking, propulsion, and step width were significantly different between the infraspinatus and no repair group and similar between the infraspinatus and two-tendon repair groups at almost all time points. These results suggest that repairing the infraspinatus back to its insertion site without repair of the supraspinatus can improve shoulder function to a level similar to repairing both the infraspinatus and supraspinatus tendons. Clinically, a partial repair of the posterior cuff after a two-tendon tear may be sufficient to restore adequate function. An in vivo model system for two-tendon repair of massive rotator cuff tears is presented.

Shoulder ultrasound

Ultrasound is used increasingly in the investigation of the rotator cuff. It is as accurate as magnetic resonance imaging in the detection of rotator cuff tears and the assessment of tear size and can demonstrate atrophy and fatty infiltration in the rotator cuff muscles. This article reviews the anatomy and technique of shoulder ultrasound, the ultrasound findings in rotator cuff disease, the accuracy of ultrasound and magnetic resonance imaging in the assessment of rotator cuff tears and the role of interventional ultrasound of the shoulder.

Evaluation of fatty degeneration of the supraspinatus muscle using a new measuring tool and its correlation between multidetector computed tomography and magnetic resonance imaging

BACKGROUND

The assessment of fatty degeneration of rotator cuff muscles with a reliable grading system is very important. However, there is no generally accepted tool to measure it quantitatively.

PURPOSE

This work was undertaken to introduce a new method to evaluate fatty degeneration by calculating the occupation ratio of the supraspinatus, to determine the correlation between this occupation ratio and the degree of Goutallier's fatty degeneration or tear size of rotator cuff muscles and to assess the correlation between multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) using this new measuring tool.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Sixty-one patients with full-thickness rotator cuff tears who had undergone arthroscopic rotator cuff repair were included. The occupation ratio was measured using the magic selection tool in Photoshop on MDCT and both T1- and T2-weighted oblique sagittal magnetic resonance images of Y-view. One-way analysis of variance was used to determine the association between this occupation ratio and the degree of fatty degeneration as assessed by Goutallier's method. The correlation between the occupation ratio and tear size, and the correlation of the occupation ratio between MDCT and MRI, were evaluated using the Pearson correlation coefficient. In addition, the interobserver and intraobserver reliabilities of this measuring tool were assessed on each image by 2 orthopaedic surgeons and analyzed using interclass correlation coefficients.

RESULTS

Comparison of the occupation ratio measured by this new method with the Goutallier grade of fatty degeneration on MDCT and MRI revealed a highly significant correlation, with all P values < .001. Also, comparison of this new occupation ratio and cuff tear size showed a reverse correlation on MDCT, T1-weighted magnetic resonance images, and T2-weighted images, with Pearson correlation coefficients of -.61, -.56, and -.50 (all P < .001) by rater 1, and -.57, -.53, and -.43 (all P < .001) by rater 2. Comparison of the occupation ratio between MDCT and MRI demonstrated significant correlation, with Pearson correlation coefficients of .78 and .87 between MDCT and T1-weighted magnetic resonance images and .73 and .82 between MDCT and T2-weighted images. The interobserver and intraobserver reliabilities of this new measuring tool on MDCT and both T1- and T2-weighted magnetic resonance images were excellent in all images, with interobserver correlation of .89, .92, and .91 and intraobserver correlation of .89 and .96, .90 and .98, and .85 and .97, respectively.

CONCLUSION

This new quantitative measuring tool to evaluate the fatty degeneration of rotator cuff muscles was reliable and correlated well with both the preexisting grade of fatty degeneration and cuff tear size. Also, there was a significant correlation between oblique sagittal images of MDCT and MRI using this method; therefore, MDCT can be another option for imaging modality, comparable with MRI, for the evaluation of fatty degeneration of rotator cuff muscles.

Clinical and structural evaluation of arthroscopic double-row suture-bridge rotator cuff repair: early results of a novel technique

PURPOSE

Assessment of repair integrity and clinical outcome after arthroscopic repair of rotator cuff tears in double-row suture-bridge technique with the use of a new knotless suture-anchor system.

METHODS

The first treated 25 patients with arthroscopic rotator cuff repair in the suture-bridge technique using a novel knotless anchor and chain-link suture system were evaluated. Patients with isolated full-thickness supraspinatus tears were selected. They were followed clinically with functional scores (Constant score, ASES index), visual analog scale (VAS), and instrumentally with Isobex digital strength analyzer preoperatively, at 6 and 14 months postoperatively. The repair integrity was evaluated with MRI at an average of 14 months postoperatively.

RESULTS

Significant improvement of pain, strength, range of motion, and functional scores occurred (P < 0.05). There was a re-tear rate of 20%. The subjective parameters (VAS and ASES Index) showed non-significant (n.s.) differences between the re-tear and intact repair groups, whereas the objective parameters (Constant score, muscle power and active ROM) showed significant differences between both groups (P < 0.05).

CONCLUSION

The functional outcome has improved significantly with this new knotless anchor-chain system and was more superior in shoulders with intact repair, whereas the resulted repair integrity was not better than other types of double-row repair techniques mentioned in the recent literature. However, this early report of the novel technique may show limited power for comparison due to the relatively small sample size.

Using chemical-shift MR imaging to quantify fatty degeneration within supraspinatus muscle due to supraspinatus tendon injuries

The objective of this study was to prospectively quantify the fatty degeneration of supraspinatus (SSP) muscle due to SSP tendon injuries by using chemical-shift magnetic resonance imaging (CS-MRI). Forty-one patients with suspected rotator cuff tear or impingement examined with MR arthrography were included in the study. The following images were obtained after injection of diluted gadolinium chelate into glenohumeral joint: fat-saturated T1-weighted spin echo in the coronal, axial, and sagittal-oblique plane; fat-saturated T2-weighted and intermediate-weighted fast spin-echo in the coronal-oblique plane; and T1-weighted spin echo in the sagittal-oblique plane. CS-MRI was performed in the coronal plane using a double-echo fast low-angle shot (FLASH) sequence. SSP tendon changes were classified as normal, tendinosis, and partial and complete tear according to MR arthrography findings. Fatty degeneration was quantified after measurement of signal intensity values within the region of interest (ROI) placed over SSP muscle. Signal intensity (SI) suppression ratio and SI index were calculated with the values obtained. Degrees of fatty degeneration depicted in normal subjects and subjects with rotator cuff injuries were compared. Median (min:max) was used as descriptive values. SI suppression ratio was -3.5% (-15.5:3.03) in normal subjects, whereas it was -13.5% (-28.55:-6.60), -30.7% (-41.5:-20.35), and -43.75% (-62:-24.90) in tendinosis, partial and complete tears, respectively. SI index was 0.75% (-6:11.5) in normal subjects. It was 10% (4.50:27), 26.5% (19.15:35.5), and 41% (23.9:57) in tendinosis, partial and complete tears, respectively. The increase in degree of fatty degeneration parallels the seriousness of tendon pathology. CS-MRI is a useful method for grading fat accumulation within SSP muscle.

The association between retraction of the torn rotator cuff and increasing expression of hypoxia inducible factor 1α and vascular endothelial growth factor expression: an immunohistological study

Background

Differing levels of tendon retraction are found in full-thickness rotator cuff tears. The pathophysiology of tendon degeneration and retraction is unclear. Neoangiogenesis in tendon parenchyma indicates degeneration. Hypoxia inducible factor 1α (HIF) and vascular endothelial growth factor (VEGF) are important inducers of neoangiogenesis. Rotator cuff tendons rupture leads to fatty muscle infiltration (FI) and muscle atrophy (MA). The aim of this study is to clarify the relationship between HIF and VEGF expression, neoangiogenesis, FI, and MA in tendon retraction found in full-thickness rotator cuff tears.

Methods

Rotator cuff tendon samples of 33 patients with full-thickness medium-sized rotator cuff tears were harvested during reconstructive surgery. The samples were dehydrated and paraffin embedded. For immunohistological determination of VEGF and HIF expression, sample slices were strained with VEGF and HIF antibody dilution. Vessel density and vessel size were determined after Masson-Goldner staining of sample slices. The extent of tendon retraction was determined intraoperatively according to Patte's classification. Patients were assigned to 4 categories based upon Patte tendon retraction grade, including one control group. FI and MA were measured on standardized preoperative shoulder MRI.

Results

HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p < 0.05). HIF and VEGF expression, and vessel density significantly increased with extent of tendon retraction (p < 0.05). A correlation between HIF/VEGF expression and FI and MA could be found (p < 0.05). There was no significant correlation between HIF/VEGF expression and neovascularity (p > 0.05)

Conclusion

Tendon retraction in full-thickness medium-sized rotator cuff tears is characterized by neovascularity, increased VEGF/HIF expression, FI, and MA. VEGF expression and neovascularity may be effective monitoring tools to assess tendon degeneration.

Learning Fourier descriptors for computer-aided diagnosis of the supraspinatus

RATIONALE AND OBJECTIVES

Supraspinatus muscle disorders are frequent and debilitating, resulting in pain and a limited range of shoulder motion. The gold standard for diagnosis involves an invasive surgical procedure. As part of a proposed clinical workflow for noninvasive computer-aided diagnosis (CAD) of the condition of the supraspinatus, we present a method to classify three-dimensional shapes of the muscle into relevant pathology groups, based on magnetic resonance (MR) images.

MATERIALS AND METHODS

We obtained MR images of the shoulder from 72 patients, separated into five pathology groups. The imaging protocol ensures that the supraspinatus is consistently oriented relative to the MR imaging plane for each scan. Next, we compute the Fourier coefficients of two-dimensional contours lying on parallel imaging planes and integrate the corresponding frequency components across all contours. To classify the shapes, we learn the Fourier coefficients that best distinguish the different classes.

RESULTS

We show that our method leads to significant improvement when compared to previous work. We are able to distinguish between normal shapes and shapes that possess a pathology with an accuracy of almost 100%. Moreover, we can differentiate between the different pathology groups with an average accuracy of 86%.

CONCLUSION

We confirm that analyzing the three-dimensional shape of the muscle has potential as a form of diagnosis reinforcement to assess the condition of the supraspinatus. Moreover, our proposed descriptor based on Fourier coefficients is able to distinguish the different pathology groups with accuracies higher than those obtained by previous work, indicating its potential application to support a system for CAD of the supraspinatus.

MRI of symptomatic and asymptomatic full-thickness rotator cuff tears. A comparison of findings in 100 subjects

BACKGROUND AND PURPOSE

Why some full-thickness rotator cuff tears are symptomatic and others are asymptomatic is not understood. By comparing MRI findings in symptomatic and asymptomatic tears, we wanted to identify any tear characteristics that differed between groups.

PATIENTS AND METHODS

50 subjects with asymptomatic and 50 subjects with symptomatic full-thickness tears were examined by MRI. Tear characteristics including tear size, tear location, the condition of the long head of the biceps, atrophy, and fatty degeneration of the muscles were compared between groups.

RESULTS

Single factor logistic regression analysis showed that there were statistically significant associations between symptoms and tear size exceeding 3 cm in the medial-lateral plane, positive tangent sign, and fatty degeneration exceeding grade 1 of the supraspinatus and infraspinatus muscles.

INTERPRETATION

We found associations between the symptomatic status of a rotator cuff tear and MRI-derived tear characteristics. The causal relationships are unclear.

Natural history of fatty infiltration and atrophy of the supraspinatus muscle in rotator cuff tears

BACKGROUND

In some patients nonoperative treatment of a rotator cuff tear is sufficient, while in others it is only the first stage of treatment prior to surgery. Fatty infiltration progresses throughout the nonoperative treatment although it is not known at what point fatty infiltration contributes to poor functional outcomes, absence of healing, or increased rerupture rates.

QUESTIONS/PURPOSES

We therefore identified factors related to the appearance of supraspinatus muscle fatty infiltration, determined the speed of appearance and progression of this phenomenon, and correlated fatty infiltration with muscular atrophy.

METHODS

We retrospectively reviewed 1688 patients with rotator cuff tears and recorded the following: number of tendons torn, etiology of the tear, time between onset of shoulder symptoms and diagnosis of rotator cuff tear. Fatty infiltration of the supraspinatus was graded using either CT or MRI classification. Muscular atrophy was measured indirectly using the tangent sign.

RESULTS

Moderate supraspinatus fatty infiltration appeared an average of 3 years after onset of symptoms and severe fatty infiltration at an average of 5 years after the onset of symptoms. A positive tangent sign appeared at an average of 4.5 years after the onset of symptoms.

CONCLUSIONS

Our results suggest that rotator cuff repair should be performed before the appearance of fatty infiltration (Stage 2) and atrophy (positive tangent sign)-especially when the tear involves multiple tendons.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Reliability of the grading system for fatty degeneration of rotator cuff muscles

Fatty degeneration of the rotator cuff muscles is considered one of the most important factors for the outcomes of cuff repair. However, the reliability of the grading system is not well validated. Two specialists in musculoskeletal radiology and three shoulder fellowship-trained orthopaedic surgeons reviewed the fatty degeneration grades of each cuff muscle of consecutive 75 full-thickness cuff tears. Fatty degeneration grades were assessed according to the systems of Goutallier et al. and Fuchs et al. using preoperative MR and postoperative CT arthrographies. The interclass correlation coefficient was analyzed to assess interobserver and intraobserver reliabilities. For interobserver reliability using the system of Goutallier et al. the interclass correlation coefficient was higher in MR arthrography (0.6-0.72) than in CT arthrography (0.43-0.6) and higher for radiologists (0.58-0.78) than for orthopaedic surgeons (0.32-0.68). There was no difference between the systems of Goutallier et al. and Fuchs et al. Intraobserver reliabilities showed a similar pattern (0.26-0.81), but the level of experience should be considered. Although the system of Goutallier et al. is most widely used in orthopaedics, reported data should be interpreted carefully because of the relatively low reliability.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic supraspinatus tendon repair with suture-bridging technique: functional outcome and magnetic resonance imaging

BACKGROUND

The suture-bridging technique is a new arthroscopic technique to repair rotator cuff tears. Biomechanical advantages compared with double-row fixations have been described.

HYPOTHESIS

The authors hypothesized that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fifty-one consecutive patients, with a median age of 62 years (range, 37-76 years), who had undergone an arthroscopic suture-bridging repair of an isolated supraspinatus tendon tear were evaluated in this prospective study 4, 12, and a median of 24 months postoperatively. Subjective and functional outcome was assessed using the simple shoulder test and Constant score. With magnetic resonance imaging 12 months postoperatively, the tendon integrity and potential predictors of failures were evaluated.

RESULTS

The simple shoulder test scores improved significantly from 9 points (range, 1-12 points) at 4 months, to 12 points (range, 1-12 points) at 12 months, and 12 points (range, 5-12 points) at 24 months postoperatively. The Constant score increased significantly from preoperative 64% (range, 37%-92%) to 82% (range, 36%-100%) at 4 months, 96% (range, 49%-100%) at 12 months, and 96% (range, 64%-100%) at 24 months postoperatively. Magnetic resonance imaging 12 months after surgery showed retears in 28.9%. Two different types of retears could be observed: insufficiently healed and medially retorn supraspinatus tendons. The Constant score did not differ significantly between the groups with retears and intact repairs. A patient age of more than 60 years was found to influence tendon healing significantly.

CONCLUSION

The hypothesis, that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation, could not be confirmed. The functional outcome after the new suture-bridging technique was good and comparable with the reported results after double-row repair from the literature. A structural failure of tendon repair was not identical to clinical failure.

The level of vitamin D in the serum correlates with fatty degeneration of the muscles of the rotator cuff

This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D(3)) were measured. In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman's correlation coefficients were 0.173 (p = 0.001), -0.181 (p = 0.001), and -0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus. The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.

The long-term outcome of recurrent defects after rotator cuff repair

BACKGROUND

Retears of the rotator cuff are not uncommon after arthroscopic and mini-open rotator cuff repairs. In most studies, the clinical results in patients with persistent defects demonstrated significantly less pain and better function and strength compared with their preoperative state at an early follow-up.

HYPOTHESIS

The clinical and structural outcomes of patients with known rotator cuff defects will remain unchanged after a longer period of follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study was performed in 15 patients (18 shoulders) from a previous study who had recurrent rotator cuff defects 3.2 years after repair. Each patient completed the American Shoulder and Elbow Surgeons Scoring Survey, the Simple Shoulder Test, the L'Insalata Scoring Survey, and a visual analog scale for pain. Eleven patients (13 shoulders) were clinically reexamined at an average of 7.9 years for range of motion and strength, with targeted ultrasound.

RESULTS

At the 7.9 year follow-up the average scores were 95 (American Shoulder and Elbow Surgeons), 95 (L'Insalata), 11 (Simple Shoulder Test), and 0 (visual analog for pain), which were not statistically significantly different from the scores at 3.2 years. There was no change in the average range of motion; however, there was a statistically significant reduction in forward flexion strength and external rotation strength, as measured by a dynamometer. The average external rotation strength decreased by a mean of 42% and the mean forward flexion strength decreased by a mean of 45% (P < .001). Furthermore, there was a statistically significant increase in the mean size of the defect, from 273 mm(2) to 467 mm(2) (P < .001). Finally, the size of the defect increased in all patients, and no defects healed structurally.

CONCLUSION

At an average of 7.9 years, patients with recurrent defects after rotator cuff repair still had an improvement in terms of pain, function, and satisfaction. However, the rotator cuff defect significantly increased in size, and there was a progression of strength deficits. These findings suggest that patients with recurrent defects can remain asymptomatic over the long term but will predictably lose strength in the involved extremity. Furthermore, the study demonstrated that defects after rotator cuff repair increase in size but often remain asymptomatic.

Long-term clinical and MRI results of open repair of the supraspinatus tendon

Open repair of full-thickness tears of the rotator cuff generally improves function, although anatomic failures are not uncommon. We asked whether the presence or absence of an anatomic repair influenced outcomes. We retrospectively analyzed 47 patients (49 shoulders) treated by open proximalized reinsertion of the supraspinatus tendon for chronic retracted detachment. The mean age of the patients at the time of surgery was 59 years. At a minimum 60-month followup (mean, 87 months; range, 60-133 months), we observed an improvement in the age- and gender-adjusted Constant-Murley score from 67% preoperatively to 95% postoperatively and in the pain score. With the last followup MRI, the supraspinatus tendon had reruptured in five patients (12%); the presence of a rerupture did not negatively influence the functional result. Once healing of the repaired tendons was achieved, supraspinatus muscle atrophy never worsened. However, on MRI, fatty infiltration of the supraspinatus, infraspinatus, and subscapularis muscles increased postoperatively despite tendon healing. Radiographic centering of the humeral head was preserved and glenohumeral arthritis remained stable. Functional results were better when the standardized supraspinatus muscle area was greater than 0.5 at the final evaluation.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Effects of rotator cuff ruptures on the cellular and intracellular composition of the human supraspinatus muscle

Ruptures of the rotator cuff tendons of the human shoulder are a common incidence and lead to functional impairment of the four muscles connected to the cuff, entailing profound changes of their cellular tissue composition. Most importantly, such tendon tears lead to atrophy, fatty degeneration and fibrosis of the corresponding muscles. The muscle most commonly affected with such changes is the M. supraspinatus. The present study uses biopsy samples from the supraspinatus muscle of 12 elderly patients and 6 controls to examine the rupture-induced muscle change at both the cellular and the intracellular (ultrastructural) levels. Amounts of fatty tissue, connective tissue and muscle were assessed by light microscopy-based morphometry and stereology. Stereology of electron micrographs was employed to determine volume densities of muscle fibre mitochondria, myofibrils and intracellular lipid. Results demonstrate that the supraspinatus muscles of patients with a massive rupture contain significantly higher amounts not only of fatty tissue but also of intracellular lipid than those of control subjects. These patients further exhibit a major decrease in relative amounts of myofibrils, thus confirming that change of intracellular composition is a major component of the observed muscle degeneration. The results contribute to establish the true spectrum of supraspinatus muscle damage in humans induced by tendon rupture.

Outcome of nonoperative treatment of symptomatic rotator cuff tears monitored by magnetic resonance imaging

BACKGROUND

Rotator cuff tears are very common, but little is known about the outcome of nonoperative treatment of symptomatic tears in terms of progression and the need for surgical intervention.

METHODS

Fifty-nine shoulders in fifty-four patients (thirty-three women and a mean age of 58.8 years) with rotator cuff tears on initial magnetic resonance imaging who had been managed nonoperatively were studied retrospectively. All had magnetic resonance imaging scans acquired six months or more after the initial study. The progression of the rotator cuff tears was associated with age, anatomical and associated parameters, follow-up time, and structural and other magnetic resonance imaging findings.

RESULTS

Baseline magnetic resonance imaging scans demonstrated thirty-three full-thickness tears, twenty-six partial-thickness tears, and four combined full-thickness and partial-thickness tears. Fifty-eight of the fifty-nine tears involved the supraspinatus tendon, and ten involved multiple tendons. Progression in tear size occurred more often among the patients who were followed more than eighteen months (thirteen [48%] of twenty-seven shoulders) compared with those who were followed for less than eighteen months (six [19%] of thirty-two shoulders). Five tears (one partial-thickness tear) decreased in size. More than half (52%; seventeen) of the thirty-three full-thickness tears increased in size compared with 8% (two) of the twenty-six partial-thickness tears (p = 0.0005). Only 17% (six) of the thirty-five tears in patients who were sixty years old or less deteriorated compared with 54% (thirteen) of the twenty-four tears in patients who were more than sixty years old (p = 0.007). No shoulder in a patient with a partial-thickness tear demonstrated supraspinatus atrophy, whereas 24% of those with a full-thickness tear demonstrated atrophy (p = 0.007). The proportion with an increase in tear size was significantly larger for shoulders with fatty infiltration than for those without it (p = 0.0089).

CONCLUSIONS

Factors that are associated with progression of a rotator cuff tear are an age of more than sixty years, a full-thickness tear, and fatty infiltration of the rotator cuff muscle(s). In the long-term follow-up of nonoperatively treated rotator cuff tears, magnetic resonance imaging can be used to monitor rotator cuff changes and guide patient management.

Appropriate slice location to assess maximal cross-sectional area of individual rotator cuff muscles in normal adults and athletes

PURPOSE

We investigated appropriate slice locations for magnetic resonance (MR) imaging evaluation of the maximal cross-sectional area (CSA) of individual rotator cuff (RC) muscles in normal adults and athletes.

METHODS

We used a 1.5-tesla MR system with body-array and spine coils to obtain oblique sagittal T(1)-weighted shoulder images of 29 normal adults (16 men, 13 women); 6 national-level competitive swimmers (4 men, 2 women); 10 collegiate-level female badminton players; and 7 collegiate-level male rowers. We calculated the supraspinatus, infraspinatus, teres minor, and subscapularis CSAs at the 0-1 locations on the scapula (dividing scapula width into 11 locations), 0 representing the medial border of the scapula and 1, the glenoid fossa surface. We evaluated the differences in CSAs at relative locations on the scapula for each muscle in normal adults, swimmers, badminton players, and rowers using a one-way analysis of variance followed by the Tukey test (P<0.05).

RESULTS

The supraspinatus CSAs were maximal at 0.7 for all groups. The infraspinatus CSAs were maximal at 0.5 for normal men and women and badminton players, 0.4- and 0.5 locations for swimmers, and 0.4 for rowers. The teres minor CSAs were maximal at 0.9 for all groups except the swimmers (1 location). The subscapularis CSAs were maximal at 0.7 in men, swimmers, and badminton players and 0.6 in women and rowers.

CONCLUSION

The appropriate slice locations for evaluating maximal CSAs are slightly lateral to the center of the scapula for the supraspinatus and subscapularis, at approximately the center of the scapula for the infraspinatus, and near the glenoid fossa for the teres minor. These slice locations should be clinically useful for morphological and/or function-related assessments of shoulder RC muscles.

Fatty infiltration of the supraspinatus: a reliability study

BACKGROUND

The Goutallier classification of rotator cuff fatty infiltration is an accepted standard, yet no recommendations exist for which computed tomography plane is best to identify fatty infiltration of the supraspinatus. Our purpose was to determine the most reliable plane to evaluate supraspinatus fatty infiltration, assess reliability of the tangent sign, and to correlate fatty infiltration and muscle atrophy.

METHODS

Fatty infiltration in 87 computed tomography scans was reviewed by 3 shoulder surgeons using the 5-tiered Goutallier classification and a separate 3-grade scale. The supraspinatus muscle was evaluated in the axial, coronal, and sagittal plane. The tangent sign was used to assess muscle atrophy.

RESULTS

The axial plane produced the highest agreement for both the 5-tiered and 3-tiered systems. An objective radiographic marker was described to reliably determine grade 3 fatty infiltration. The tangent sign produced excellent agreement for the presence of muscle atrophy. A significant relationship between the tangent sign and fatty infiltration was discovered (P < .0001); grades 3 and 4 fatty infiltration correlated statistically with supraspinatus atrophy.

CONCLUSION

The tangent sign is acceptable for determining the presence of muscle atrophy and clinical decision making. A positive tangent sign is an indicator of advanced fatty infiltration. The axial computed tomography plane should be used when evaluating fatty infiltration.

LEVEL OF EVIDENCE

Level 3; Diagnostic study.