Rotator cuff integrity and shoulder function after intra-medullary humerus nailing.

Introduction: Antegrade percutaneous intra-medullary nailing (IMN) has a poor reputation in the treatment of humerus fractures. The aim of the present study was to assess rotator cuff integrity and shoulder function after IMN in humerus fracture.
Hypothesis: Third-generation humeral nails (straight, small diameter, with locked screws) conserve rotator cuff tendon integrity and avoid the shoulder stiffness and pain incurred by 1st generation (large diameter, without self-blocking screw) and 2nd generation nails (curved, penetrating the supraspinatus insertion on the greater tuberosity).
Methods: Forty patients (26 female, 14 male; mean age, 60 years (range, 20-89 years)) with displaced humeral fracture (23 proximal humerus, 17 humeral shaft) underwent IMN using a 3rd generation nail (34 Aequalis™ (Tornier-Wright), 6 MultiLoc™ (Depuy-Synthes)). Mean clinical, radiologic and ultrasound follow-up was 8 months (range, 6-18 months); 22 patients agreed to postoperative CT scan.
Results: There were no revision surgeries for rotator cuff repair or secondary bone displacement. Mean Adjusted Constant Score (ACS) was 93±22% and the Subjective Shoulder Value (SSV) 77±18%. Elevation was 140±36°, external rotation 48±22° and internal rotation was to L3. Ultrasound found: 5 supraspinatus tendon lesions (12.5%) (2 full and 3 deep partial tears) without functional impact (ACS) 91% without vs. 107% with tear; (p=0.12); 2 of the deep partial tears involved excessively lateral and high nail positioning. Eight patients (20%) had painful tendinopathy of the long head of the biceps (LHB) tendon associated with significantly impaired functional scores (ACS 65% vs. 100%; p<0.001); and 4 cases of technical error: 3 of anterior LHB screwing in the groove, and 1 of LHB irritation due to an excessively long posterior screw.
Conclusion: Supraspinatus tendon lesions following IMN with a 3 ^rd -generation humeral nail were rare (12.5%) and asymptomatic; prevalence was not higher than in the general population in the literature (16%). LHB tendinopathy was frequent (20%) and symptomatic, and due to technical error in half of the cases.
Level of Evidence: IV, retrospective study.
(Copyright © 2019. Published by Elsevier Masson SAS.)