Surgical repair of the supraspinatus: pre- and postoperative architectural changes in the muscle.

Rohit Sachdeva; Cole Beavis; Haron Obaid; Jonathan P Farthing; Soo Y Kim

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Surgical repair of the supraspinatus: pre- and postoperative architectural changes in the muscle.

Author: Rohit SACHDEVA ¹ ; Cole BEAVIS ² ; Haron OBAID ³ ; Jonathan P FARTHING ⁴ ; Soo Y KIM ¹
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1. School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
2. Division of Orthopaedics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
3. Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
4. College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Publication Type:Journal Article
Keywords: fibre bundle length; full-thickness tear; muscle architecture; pennation angle; rotator cuff repair
MeSH: Humans; Rotator Cuff/surgery*; Rotator Cuff Injuries/surgery*; Shoulder/surgery*; Shoulder Joint/surgery*; Tendons
From:Singapore medical journal 2022;63(2):97-104
CountrySingapore
Language:English
Abstract: INTRODUCTION:Shortening of the tendon and muscle is recognised as a strong predictor of surgical failure of supraspinatus tendon tears. Changes in muscle architecture following repair have not been thoroughly investigated. Hence, we aimed to compare the pre- and postoperative architecture of the supraspinatus.
METHODS:We recruited eight participants with full-thickness supraspinatus tears. Images of the supraspinatus were captured preoperatively (pre-op) and postoperatively at one month (post-op1), three months (post-op2) and six months (post-op3) in relaxed and contracted states (0º and 60º glenohumeral abduction). Fibre bundle length (FBL), pennation angle (PA) and muscle thickness were quantified. Self-reported function, and maximal isometric abduction and external rotation strengths were assessed.
RESULTS:The mean FBL increased from pre-op to post-op1 (p = 0.001) in the relaxed state and from pre-op to post-op2 (p = 0.002) in the contracted state. Decrease in FBL was observed from post-op2 to post-op3 in the relaxed state. The mean PA decreased from pre-op to post-op1 (p < 0.001) in the relaxed state, but increased from post-op2 to post-op3 in both relaxed (p = 0.006) and contracted (p = 0.004) states. At post-op3, external rotation (p = 0.009) and abduction (p = 0.005) strengths were greater than at post-op2. Overall function increased by 47.67% from pre-op to post-op3.
CONCLUSION:Lengthening of the supraspinatus occurs with surgery, altering the length-tension relationship of the muscle, which can compromise muscle function and lead to inferior surgical outcomes. These findings may guide clinicians to optimise loads, velocities and shoulder ranges for effective postoperative rehabilitation.