Retrograde Percutaneous Scaphoid Type II Nonunion Screw Fixation in Schernberg Zones 2 to 4

Abstract

Background: Regardless of the treatment used, 25% to 45% of scaphoid fractures do not heal. Open approach surgery compromises vascularization and destabilizes ligamentous attachments. The aim of this retrospective study was to assess the value of retrograde percutaneous screw fixation of Alnot stage IIA and B scaphoid nonunion considering Schernberg zone 2 to 4. Material and Method: This series included 38 patients with a mean age of 31 years old. Following the Alnot classification, there were 16 stage IIA nonunions (12 in zone 3 and 4 in zone 2 according to the Schernberg classification) and 22 stage IIB nonunions (9 in zone 3 and 13 in zone 2). The mean delay time between the initial trauma and the surgical treatment was 10 months. Percutaneous retrograde fixation was performed with a cannulated 2.7 mm compression screw. Results: At 25 months follow-up, 31 nonunions had healed (81.6%), among which 14 were stage IIA (87.5%) and 17 stage IIB (77.3%) at an average 6.3 months. Average pain was 1.6. The average Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) was 17.3/100. Compared with the opposite side, the average range of motion was 84.8% in flexion, 84.7% in extension, 98.9% in pronation, 96.5% in supination, 96.8% in ulnar inclination, and 86.4% in radial inclination, with an average 80.4% grip strength. Seven patients did not heal after screw fixation among which 4 healed after further electromagnetic stimulation and 3 after vascularized bone graft. Discussion: According to our results, stage IIA nonunions can heal with a simple retrograde percutaneous screw fixation. Concerning stage IIB, same procedure could be enough; however, we recommend the addition of a cancellous bone graft under arthroscopy. According to the authors, open surgery procedures are preferred when percutaneous procedure failed.