We hypothesized that ROM restriction could be predicted based on the AR thickness. This study aimed to investigate the correlation between ROM and AR thickness in FS patients.
The subjects were 35 patients diagnosed with FS at our hospital’s orthopedic outpatient clinic between 2020 and 2023, who underwent shoulder joint manipulation under transmission anesthesia. The mean age was 56.7 ± 10.1 years, the mean disease duration was 6.6 ± 4 months, and 12 patients were women. An orthopedic specialist administered transmission anesthesia and a physical therapist measured the ROM of forward flexion (FF), abduction (AD), and external rotation (ER) before and after transmission anesthesia. Image evaluation was performed using T2 oblique coronal MRI of the shoulder joint at the first visit, and AR thickness (mm) was measured by a radiologist. The correlation between ROM and AR thickness before and after anesthesia was investigated.
The ROM (°) was FF: 93.2 ± 17, AD: 69.3 ± 20, ER: 11.2 ± 16 before anesthesia, and FF: 114.4 ± 25, AD: 99.9 ± 34, ER: 24 ± 12 after anesthesia. The AR thickness measured by MRI was 4.8 ± 1.6 mm. There was no significant correlation between ROM before anesthesia and AR thickness. A moderate negative correlation was observed between ROM after anesthesia and AR thickness (FF: r = -0.45, P = 0.007; AD: r = -0.51, P = 0.002; ER: r = -0.44, P = 0.009).
AR thickness can be used to evaluate contracture and to indicate the severity of ROM restriction in FS.
The assessment of ROM in FS may be inaccurate because of pain and muscle contraction. AR thickness correlates with ROM after anesthesia and may be clinically useful in indicating true joint contracture.
Axillary recess thickness
Range of motion
