Changes of Supraspinatus Muscle Volume and Fat Fraction After Successful or Failed Arthroscopic Rotator Cuff Repair

Background: Muscle atrophy and fatty infiltration are limiting factors for successful rotator cuff (RC) repair. Quantitative data regarding these hallmarks of degenerative muscle changes after RC repair in humans are scarce. By utilizing a new application of the 6-point Dixon magnetic resonance imaging technology, 3-dimensional volume and fat fraction analysis of the whole RC muscle have become possible. Purpose: Quantitative analysis of atrophy and fatty infiltration of the supraspinatus muscle after healed and failed RC tendon-to-bone repair. Study Design: Cohort study; Level of evidence, 3. Methods: Muscle volume and fat fraction were measured preoperatively and at 3 and 12 months postoperatively in 19 failed and 21 healed arthroscopic supraspinatus tendon repairs, with full muscle volume segmentation and magnetic resonance Dixon sequences. Results: In both groups, the muscle volume initially decreased 3 months after RC repair by –3% in intact ( P = .140) and –10% in failed repair ( P = .004) but recovered between 3 and 12 months to 103% ( P = .274) in intact and 92% ( P = .040) in failed repairs when compared with the preoperative volume (difference of change between groups, preoperative to 12 month: P = .013). The supraspinatus muscle’s fat fraction did not significantly change after successful repair (6.5% preoperative, 6.6% after 3 months, and 6.7% after 12 months; all nonsignificant). There was, however, a significant increase from 7.8% to 10.8% at 3 months ( P = .014) and 11.4% at 12 months ( P = .020) after failed repair (difference between groups at 3- and 12-month follow-up: P = .018 and P = .001, respectively). Conclusion: After successful arthroscopic repair, RC tendon tear–induced fatty infiltration can be almost stopped, and muscle atrophy can even be slightly reversed. In case of a failed repair, however, these changes are further pronounced during the first 3 postoperative months but seem to stabilize thereafter.

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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

Arthroscopy The Journal of Arthroscopic and Related Surgery ◽

10.1016/j.arthro.2012.10.006 ◽

2013 ◽

Vol 29 (3) ◽

pp. 449-458 ◽

Cited By ~ 35

Author(s):

Chris Hyunchul Jo ◽

Ji Sun Shin

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Rotator Cuff ◽

Muscle Atrophy ◽

Rotator Cuff Repair ◽

Fatty Infiltration ◽

Resonance Imaging ◽

Time Zero ◽

Cuff Repair ◽

New Time

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The influence of fatty infiltration and muscle atrophy of the rotator cuff muscles on midterm functional outcomes in total shoulder resurfacing at six years’ follow-up

Shoulder & Elbow ◽

10.1177/1758573218811655 ◽

2018 ◽

Vol 12 (2) ◽

pp. 91-98

Author(s):

Gray AD Edwards ◽

Philip A McCann ◽

Michael R Whitehouse ◽

Charles J Wakeley ◽

Partha P Sarangi

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Rotator Cuff ◽

Muscle Atrophy ◽

Functional Outcomes ◽

Fatty Infiltration ◽

Resonance Imaging ◽

Shoulder Replacement ◽

Total Shoulder Replacement

Background We report functional outcomes at six years in patients with varying degrees of fatty infiltration and atrophy of the rotator cuff muscles who have undergone anatomic total shoulder replacement. Methods A retrospective analysis of case notes and magnetic resonance imaging scans of patients undergoing total shoulder replacement for primary glenohumeral arthritis was performed. Patients were grouped based upon their pre-operative magnetic resonance imaging findings for fatty infiltration, muscle area and tendinopathy. Post-operative functional outcomes were assessed using the Oxford Shoulder Score and Quick Disabilities of the Arm, Shoulder and Hand score. Post-operative measurements were made for active shoulder movements. Results Thirty-two patients were reviewed at a mean of 67 months following surgery. All patients demonstrated fatty infiltration on their pre-operative magnetic resonance imaging scan. Muscle atrophy was shown in 22 patients and 12 had tendinopathy. Multiple regression analysis showed no correlation between the Oxford Shoulder Score (p = 0.443), the Quick Disabilities of the Arm, Shoulder and Hand score (p = 0.419), forward flexion (p = 0.170), external rotation (p = 0.755) and any of the pre-operative independent variables. Discussion The degree of fatty infiltration, muscle atrophy and tendinopathy of the rotator cuff muscle on pre-operative magnetic resonance imaging scanning is not associated with functional outcome score or functional movement at medium-term follow-up following total shoulder replacement. Level of evidence IV

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What Is the Appropriate Reference for Evaluating the Recovery of Supraspinatus Muscle Atrophy After Arthroscopic Rotator Cuff Repair? The Occupation Ratio of the Supraspinatus May Change After Rotator Cuff Repair Without Volumetric Improvement

The American Journal of Sports Medicine ◽

10.1177/0363546518758313 ◽

2018 ◽

Vol 46 (6) ◽

pp. 1416-1423 ◽

Cited By ~ 4

Author(s):

Tsuyoshi Sasaki ◽

Hitoshi Shitara ◽

Atsushi Yamamoto ◽

Noritaka Hamano ◽

Tsuyoshi Ichinose ◽

...

Keyword(s):

Rotator Cuff ◽

Muscle Atrophy ◽

Rotator Cuff Repair ◽

Transverse Direction ◽

Muscle Volume ◽

Arthroscopic Rotator Cuff Repair ◽

3 Dimensional ◽

Supraspinatus Muscle ◽

Arthroscopic Rotator Cuff ◽

Cuff Repair

Background: Supraspinatus muscle atrophy is typically assessed by the occupation ratio of the cross-sectional area of the muscle belly to the supraspinatus fossa at the medial border of the coracoid process in a slice along the oblique-sagittal plane on MRI. Previous studies have shown that the occupation ratio of the supraspinatus changed soon after rotator cuff repair compared with before surgery. However, no studies have examined the perioperative change in the muscle volume assessed with 3-dimensional measurement. Purpose: To compare the volume of the supraspinatus muscle before and soon after surgery by using 3-dimensional imaging and to elucidate whether the changes in the occupation ratio represent corresponding changes in the muscle volume. Study Design: Cohort study; Level of evidence, 3. Methods: Thirty shoulders of patients who underwent arthroscopic rotator cuff repair were evaluated. T2-weighted images were obtained before surgery and 2 weeks after surgery. After the muscle and its tendon borders were plotted, the supraspinatus and its tendon were segmented with interactive thresholding in all slices. The 3-dimensional images were then reconstructed and the volumes calculated. Changes in the muscle volume and the occupation ratio were evaluated via 3-dimensional and 2-dimensional image assessments. The 3-dimensional and 2-dimensional findings before and after surgery were compared by use of paired t tests. Results: The mean muscle volume did not change significantly at a time point soon after surgery in any group. In patients with little medial retraction (n = 7) or isolated detachment at the superior facet (n = 17), no significant differences were noted in the occupation ratio after surgery compared with before surgery. In contrast, in patients with moderate medial retraction (n = 23) or extended tearing in the transverse direction (n = 13), the occupation ratio increased significantly. Conclusion: Although the muscle volume did not change soon after surgery compared with the preoperative values, in patients with moderate medial retraction or extended tearing in the transverse direction, the occupation ratio increased, probably due to lateral traction of the supraspinatus muscle. We recommend that MRI findings obtained soon after surgery be used as the time-zero reference for evaluating the postoperative changes in the supraspinatus.

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Fatty infiltration in the intact supraspinatus tendon; a normal physiological response with increasing age and female gender

Shoulder & Elbow ◽

10.1177/17585732211024504 ◽

2021 ◽

pp. 175857322110245

Author(s):

Ailsa Wilson ◽

Simon BM MacLean

Keyword(s):

Rotator Cuff ◽

Muscle Atrophy ◽

Surgical Repair ◽

Fatty Infiltration ◽

Female Gender ◽

Supraspinatus Tendon ◽

Rotator Cuff Tears ◽

Supraspinatus Muscle ◽

Cuff Tear ◽

3.0 T

Background Fatty infiltration and muscle atrophy of supraspinatus are used as markers of chronicity in rotator cuff tears and are known to both be independently related to poorer outcomes following surgical repair.1 We hypothesized that supraspinatus muscle atrophy and fatty infiltration increases with age irrespective of whether the rotator cuff is intact and therefore cannot be used as accurate markers for chronicity. Method Retrospective review of 280 patients who underwent 3.0 T shoulder MRI’s with either a normal scan or rotator cuff tear. Two independent observers reviewed the images. Data collected included intact rotator cuff tendons looking specifically at supraspinatus muscle height/length: suprascapular fossa ratio, tangent sign and Goutallier grade for fatty infiltration. Results There were 90 scans with intact rotator cuff tendons. Mean age was 51 years (range 17–86); 52 males, 38 females. On multiple regression analysis, there was a positive correlation of age with fatty infiltration and muscle atrophy on all parameters in the normal intact cuff. Females were significantly more likely than males to have a higher grade of fatty infiltration. Conclusion Age and female gender are risk factors for rotator cuff atrophy and fatty infiltration in patients with normal rotator cuffs. Therefore, these parameters should be used with caution by surgeons when deciding on tear chronicity and the potential to repair the torn rotator cuff.

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Magnetic Resonance Imaging Appearance of the Hip Musculature After Arthroscopic Labral-Level Iliopsoas Tenotomies

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117707498 ◽

2017 ◽

Vol 5 (5) ◽

pp. 232596711770749 ◽

Cited By ~ 8

Author(s):

Brian E. Walczak ◽

Donna G. Blankenbaker ◽

Michael R. Tuite ◽

James S. Keene

Keyword(s):

Magnetic Resonance ◽

Muscle Atrophy ◽

Vastus Lateralis ◽

Fatty Infiltration ◽

Case Series ◽

Psoas Muscle ◽

Gluteus Maximus ◽

Rectus Femoris ◽

Low Grade ◽

Level Of Evidence

Background: Iliopsoas (IP) muscle atrophy is a known consequence of open IP tenotomy, but the severity of IP muscle atrophy that occurs after arthroscopic labral-level IP tenotomies has not been documented. Purpose: To document the severity of muscle atrophy that occurs in the iliacus, psoas, and adjacent hip musculature after arthroscopic labral-level IP tenotomy. Study Design: Case series; Level of evidence, 4. Methods: Twenty-eight patients who had magnetic resonance arthrograms (MRAs) obtained prior to and 3 months to 5 years after arthroscopic labral-level IP tenotomies are the basis of this report. The pre- and postoperative MRAs of each patient were examined in consensus by 2 musculoskeletal radiologists who graded the postoperative muscle atrophy from 0 (no fatty infiltration) to 4 (>75% fatty infiltration) and noted any compensatory muscle hypertrophy or abnormal IP tendon morphology. Patients also were assessed with the Byrd 100-point modified Harris Hip Scoring system (MHHS) preoperatively and at the time of their postoperative MRA. Results: Postoperative MRAs were obtained on average 1.7 years (range, 3 months to 5 years) after hip arthroscopy. None of the patients had muscle atrophy on their preoperative MRAs. In contrast, 89% of patients had iliacus and psoas muscle atrophy on their postoperative MRAs, but only 2 (7%) developed grade 4 atrophy, and the majority (64%) had either grade 1 (n = 15) or no atrophy (n = 3). In addition, there were no significant differences in the MHHS of the patients with mild (grades 0-1), moderate (grades 2-3), or severe (grade 4) postoperative atrophy. Postoperative MRAs also demonstrated low-grade atrophy (grades 1-2) in the quadratus femoris (n = 5) and rectus femoris (n = 1) muscles, and 16 patients (57%) had distortion of the tendon, but none had a gap in their tendon. Conclusion: A majority of patients (89%) developed IP muscle atrophy after arthroscopic labral-level IP tenotomies, and although this percentage was similar (89% vs 90%) to that reported with lesser trochanteric IP tenotomies, the patients did not (1) develop atrophy of the gluteus maximus and vastus lateralis muscles, (2) have chronic IP tendon disruption, or (3) develop the severity of IP atrophy (55% grade 4 vs 7% grade 4) that has been reported after arthroscopic lesser trochanteric IP tenotomies.

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Muscle Degeneration Induced by Sequential Release and Denervation of the Rotator Cuff Tendon in Sheep

Orthopaedic Journal of Sports Medicine ◽

10.1177/23259671211025302 ◽

2021 ◽

Vol 9 (8) ◽

pp. 232596712110253

Author(s):

Karl Wieser ◽

Florian Grubhofer ◽

Anita Hasler ◽

Tobias Götschi ◽

Silvan Beeler ◽

...

Keyword(s):

Rotator Cuff ◽

Muscle Atrophy ◽

Fatty Infiltration ◽

Tendon Repair ◽

Suprascapular Nerve ◽

Muscle Volume ◽

Nerve Lesion ◽

Tendon Tear ◽

Sequential Release ◽

Magnetic Resonance Imaging Mri

Background: In a sheep rotator cuff model, tenotomy predominantly induces fatty infiltration, and denervation induces mostly muscle atrophy. In clinical practice, myotendinous retraction after tendon tear or lateralization after tendon repair tear may lead to traction injury of the nerve. Purpose/Hypothesis: To analyze whether an additional nerve lesion during rotator cuff repair leads to further degeneration of the rotator cuff muscle in the clinical setting. We hypothesized that neurectomy after tendon tear would increase atrophy as well as fatty infiltration and that muscle paralysis after neurectomy would prevent myotendinous retraction after secondary tendon release. Study Design: Controlled laboratory study. Methods: Twelve Swiss alpine sheep were used for this study. For the 6 sheep in the tenotomy/neurectomy (T/N) group, the infraspinatus tendon was released; 8 weeks later, the suprascapular nerve was transected. For the 6 sheep in the neurectomy/tenotomy (N/T) group, neurectomy was performed, and the infraspinatus was tenotomized 8 weeks later. All sheep were sacrificed after 16 weeks. Magnetic resonance imaging (MRI) was performed before the first surgery (baseline) and then after 8 and 16 weeks. The MRI data were used to assess muscle volume, fat fraction, musculotendinous retraction, pennation angle, and muscle fiber length of the infraspinatus muscle. Results: Three sheep (2 in the T/N and 1 in the N/T group) had to be excluded because the neurectomy was incomplete. After 8 weeks, muscle volume decreased significantly less in the T/N group (73% ± 2% of initial volume vs 52% ± 7% in the N/T group; P < .001). After 16 weeks, the mean intramuscular fat increase was higher in the T/N group (36% ± 9%) than in the N/T group (23% ± 6%), without reaching significance ( P = .060). After 16 weeks, the muscle volumes of the N/T (52% ± 8%) and T/N (49% ± 3%) groups were the same ( P = .732). Conclusion: Secondary neurectomy after tenotomy of a musculotendinous unit increases muscle atrophy. Tenotomy of a denervated muscle is associated with substantial myotendinous retraction but not with an increase of fatty infiltration to the level of the tenotomy first group. Clinical Relevance: Substantial retraction, which is associated with hitherto irrecoverable fatty infiltration, should be prevented, and additional neurogenic injury during repair should be avoided to limit the development of further atrophy.

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