Glenohumeral arthrodesis improves elbow flexion in patients with adult brachial plexus injuries.

Restoring elbow flexion is a focus in treating brachial plexus injuries (BPI), aiming for anti-gravity strength (mBMRC grade ≥3). However, patients with flail or subluxated glenohumeral (GH) joints may struggle to achieve adequate strength due to energy lost stabilizing the GH joint. This study evaluates whether glenohumeral arthrodesis (GHA) can improve elbow flexion in BPI patients with prior failed elbow reconstruction and identifies preoperative factors affecting outcomes. A retrospective review of adult BPI patients with prior elbow flexion reconstruction who later underwent GHA was conducted. Inclusion criteria were patients with preoperative mBMRC grade <3. Demographics, BPI level, prior surgeries, motion, and mBMRC grade were collected. Primary outcome was change in elbow flexion strength. Secondary outcomes included changes in elbow motion and total arc of motion. Statistical analyses were performed to assess changes from pre- to postoperative and identify factors affecting outcomes. Sixteen patients (mean age 40 years) were included, with a mean follow-up of 55 weeks. Significant postoperative improvements were noted in elbow flexion motion, total arc of motion, and mBMRC elbow flexion grade. Preoperative elbow flexion strength was inversely correlated with postoperative strength and arc of motion. Four patients did not achieve antigravity strength, with only two failing to improve post-GHA. Increased age was a risk factor for failure to improve elbow flexion. In conclusion, glenohumeral arthrodesis improves elbow flexion strength and range of motion in BPI patients with prior failed elbow reconstruction. GHA should be considered for patients with flail shoulders and inadequate strength following previous elbow surgery.