What is Manipulation Under Anesthesia (MUA) shoulder surgery?

What is Manipulation Under Anesthesia (MUA) for Shoulder?

MUA for shoulder is a non-surgical procedure where a physician forcefully moves a stiff shoulder joint through its full range of motion while the patient is under general or regional anesthesia, primarily used to treat frozen shoulder (adhesive capsulitis) by breaking up adhesions and restoring mobility.

Definition and Mechanism

• MUA involves manually manipulating the glenohumeral joint while the patient is anesthetized to break up adhesions and scar tissue that restrict shoulder movement 1
• The procedure specifically targets the ball-and-socket shoulder joint, which normally allows flexion, extension, adduction, abduction, and rotation but becomes severely restricted in frozen shoulder 2
• Modern techniques utilize Codman's paradox to manipulate the shoulder, which avoids rotational torque on the humerus and reduces the risk of complications like fractures 1

Primary Indication

• MUA is specifically indicated for idiopathic frozen shoulder (adhesive capsulitis) that has failed conservative management 1, 3
• The procedure is typically considered when patients have stage 2 frozen shoulder with lessening pain compared to stage 1, external rotation less than 50% of the contralateral shoulder, symptoms lasting at least 3 months, and failure to respond to intra-articular corticosteroid injection 3

Clinical Outcomes

• Immediate results are dramatic: ROM improves significantly as early as 3 weeks post-procedure, with forward elevation improving from 91° to 154°, abduction from 69° to 150°, and external rotation from 10° to 46° 1
• Pain scores improve substantially, with visual analog scale scores improving from 4.4/15 to 9.6/15 at 3 weeks 1
• Long-term durability is excellent: Motion and pain relief persist for decades, with one study showing maintained improvement at 23 years follow-up, though ROM may deteriorate by 8° to 23° over time while still equaling the contralateral shoulder 4
• Patient satisfaction rates reach approximately 85% 3

Re-intervention Considerations

• Approximately 17.8% of patients require a repeat MUA for persistent or recurrent symptoms 5
• Repeat MUA is highly effective: Patients with recurrent frozen shoulder after initial MUA show similar improvement (mean Oxford Shoulder Score improvement of 14 points) regardless of the outcome of the initial procedure or timing of recurrence 5
• Patients with type 1 diabetes have a 38% risk of requiring repeat MUA compared to 18% in the general population 5

Safety Profile

• The overall complication rate is remarkably low at 0.4% when proper technique is used 3
• Using Codman's paradox technique specifically avoids rotational torque and minimizes fracture risk 1
• The procedure can even be performed under local anesthesia (suprascapular nerve block with intra-articular injection) as a minimally invasive alternative to general anesthesia 6

Important Distinction from Shoulder Arthroplasty

• MUA is not a surgical procedure and does not involve implants, incisions, or joint replacement 1, 6
• This contrasts with shoulder arthroplasty procedures (total shoulder replacement or reverse shoulder replacement), which are surgical interventions for different conditions like rotator cuff tear arthropathy or severe glenohumeral osteoarthritis 7, 8

Common Pitfall to Avoid

• Do not confuse MUA with shoulder arthroplasty—they are entirely different interventions for different pathologies. MUA treats frozen shoulder through manual manipulation, while arthroplasty surgically replaces the joint for degenerative conditions 7, 1