Introduction
Non-operative treatment is generally prescribed for individuals with symptomatic rotator cuff tears (RCT) and is successful for approximately 50-75% of individuals [1-4]. Reasons for failure of non-operative treatment may include the lack of a structured and individualized treatment approach, inability to improve glenohumeral kinematics, and increases in RCT size. The objectives of the study were to evaluate the effectiveness of a 12-week structured and individualized exercise therapy approach for non-operative treatment of RCTs in respect to joint function, patient reported outcomes (PROs), and tear size.
Methods
109 individuals (60.9 ± 9.9 years of age, BMI 28.7 ± 5.0 kg/m2) with symptomatic isolated supraspinatus tears were recruited for this prospective study and provided IRB-approved written consent. Participants underwent a 12-week structured and individualized exercise therapy program and assessments of passive glenohumeral ROM (abduction, flexion, IR/ER at 90° of humerothoracic abduction), isometric rotator cuff muscle strength (IR/ER at 0° of humerothoracic abduction, ER and scapular plane abduction at 90° humerothoracic abduction), and ultrasonography to measure AP tear size. Glenohumeral kinematics during scapular plane abduction were measured using biplane radiography [5]. The total distance traveled by the contact center of the humerus on the glenoid (determined using bone-to-bone distances) was also quantified as the contact path length. PROs including the American Shoulder and Elbow Surgeons Score (ASES) and Western Ontario Rotator Cuff Index (WORC) were also collected. Paired-t tests or Wilcoxon Signed Rank tests were used to determine changes in variables from pre- to post-exercise therapy. Significance was set at p < 0.05.
Results
101 individuals successfully completed the exercise therapy program. Three individuals failed during the course of the 12-week exercise therapy program and five individuals were either lost to follow-up/withdrew from the study. Significant improvements were found for all passive glenohumeral ROM and isometric rotator cuff strength measurements (p<0.012 for all), and the ASES and WORC (p=0.001), without increases in AP tear size post-exercise therapy (p=0.313). Maximum glenohumeral elevation significantly increased by 4.5° (p=0.001) and glenohumeral contact path length decreased by 6.5% glenoid size post-exercise therapy (p=0.001).
Discussion
A structured and individualized exercise therapy program for individuals with a symptomatic isolated supraspinatus tear resulted in improved glenohumeral joint function and patient reported outcomes without increasing tear size at 12-week follow-up. Improvements in passive ROM, isometric muscle strength and PROs are consistent with previous literature [4,6,7]. Decreases in contact path length may imply more joint stability with better control of the humeral head on the glenoid and was likely due to improved muscle strength. Increased glenohumeral abduction was likely due to improved passive ROM and decreases in pain via improved PROs. Furthermore, no overall changes in AP tear size occurred post-exercise therapy and only 5 individuals experienced increases in tear size of >=5.0mm. This novel finding has important clinical implications where risk of tear propagation post-exercise therapy may be minimal. Based on the results of the current study, a 12-week structured and individualized exercise therapy program is a viable treatment option for individuals with a symptomatic isolated supraspinatus tear.
REFERENCES: [1] Itoi E J Orthop Sci. 2013, [2] Itoi E, Tabata S, Clinical Orthopaedics and Related Research 1992, [3] Kuhn JE et al. JSES 2009, [4] Kuhn JE et al. JSES 2013, [5] Bey MJ et al. J Biomech Eng. 2006, [6] Miller RM et al. JSES 2016, [7] Baumer TG et al. OJSM 2016