Objective
To evaluate the capsular stiffness of the gleno-humeral joint by measuring the slope of pressure- volume curves generated during intra-articular hydraulic distension (IHD) and analyze its correlation with clinical variables and outcomes in terms of limitation of range of motion (LOM) and severity of pain. Method: IHD with real-time intra-articular pressure mo-nitoring was performed for 53 patients with adhesive capsulitis and the capsular stiffness was measured from pressure-volume curves by calculating the slope of elastic deformation region. LOM, measured by LOM score and sum of ROMs (range of motion), and degree of pain, measured by visual analog scale (VAS), were evaluated before and after IHD: three days (3D) and one month (1M) after IHD. Results: In patients with stiffer capsules, LOM and pain were severe before IHD (Pearson's correlation coefficient (r)= 0.291, -0.348, 0.381 and p=0.065, 0.026, 0.014 for LOM score, sum of ROMs and VAS, respectively. By this order, henceforth). On 3D follow up, the correlation between the stiffness and LOM or pain was maintained (r=0.291, -0.348, 0.381 and p=0.065, 0.026, 0.014). The improvement of LOM score on 3D follow up was less as the capsules were stiffer (r=-0.368, p=0.023). On 1M follow up, LOM remained severer in stiffer capsules whereas pain did not (r=0.372, -0.402, 0.183 and p=0.039, 0.025, 0.342). Conclusion: The stiffness of the glenohumeral joint capsule, measured from the slope of pressure-volume curves during IHD, showed significant correlation with the severity of LOM and pain in patients with adhesive capsulitis of shoulder. (J Korean Acad Rehab Med 2009; 33: 205-214)
