Comparative study of the joint and functional efficacy of the Equimolar Oxygen-Nitrous Oxide Mixture (MEOPA) in the rehabilitation of adhesive capsulitis of the shoulder

INTERVENTION: Trade Name: kalinox Product Name: Kalinox Pharmaceutical Form: Inhalation gas Pharmaceutical form of the placebo: Inhalation gas Route of administration of the placebo: Inhalation use CONDITION: Adhesive capsulitis of the shoulder INCLUSION CRITERIA: Male or female over 18 years of age, presenting with adhesive capsulitis of the shoulder for more than 3 months, with a limitation of range of motion of more than 50% in at least two directions with constant discomfort in daily activities. Are the trial subjects under 18? No. Number of subjects for this age range: F.1.2 Adults (18–64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range PRIMARY OUTCOME: Main Objective: To demonstrate the superiority of a conventional rehabilitation protocol under analgesia with an equimolar Oxygen-Nitrous Oxide mixture for adhesive capsulitis of the shoulder by measuring the gain on the Constant score, including the study of joint ranges of motion in the glenohumeral joint in the three planes of space (Abduction, Flexion, External Rotation with elbow at the side). Primary end point(s): Main criterion; The aim of this study is to demonstrate that, under controlled rehabilitation conditions, the comfort of a rehabilitation session (less pain and discomfort) influences joint recovery and therefore functional prognosis. Since natural progression allows for recovery within 2 years, it seems appropriate to measure the improvement over time on the Constant score, a validated joint and functional reference test available in English and French, following a standard intensive rehabilitation protocol with or without nitrous oxide/oxygen mixture (MEOPA). This conservative treatment would then be a preferred option for this chronic and difficult-to-treat condition. The primary endpoint is the improvement in the Constant score under MEOPA compared to the placebo group at day 15. Secondary endpoint(s): Secondary endpoints include overall range of motion, functional scores, quality of life, treatment satisfaction, and analgesic consumption. The overall passive range of motion improvement in the three principal directions of abduction and external rotation with the elbow at the side is also considered. Shoulder range of motion gain (overall assessment: glenohumeral and scapulothoracic) in active and passive movements: lateral elevation; anterior elevation; elevation in the scapular plane; external rotation of the arm, arm at 90° of lateral elevation; internal rotation combined with abduction; lateral elevation measured by the Thumb-C7 distance in active and passive movements (Assessment at days 7, 15, 45, and 180).; Limitation of the physiotherapist's activity due to pain, assessed on a 6-point Likert scale: (none to extremely significant) (Assessment of each session from days 1 to 15).; Patient's assessment of the session using a VAS (Visual Analogue Scale): session interrupted by pain = 10 to session proceeding under excellent conditions = 0 (Assessment of each session from days 1 to 15). Functional gain as assessed by the DASH self-assessment questionnaire (evaluation at days 7, 15, 45, and 180); Changes in the Constant algo-functional score outside of the assessment at day 15 (evaluation at days 7, 45, and 180); Changes in the SF-36 score over time (evaluation at days 15, 45, and 180); Medication intake will be standardized (same type of analgesics for all included patients) and recorded in the protocol log. Secondary Objective: To study the evolution of active and passive glenohumeral and overall joint ranges of motion, functional recovery (DASH), and quality of life (SF-36); To study the difference in VAS scores during rehabilitation sessions and throughout the rehabilitation stay (kinetics); Influence on analgesic consumption.