Treatment of chronic mallet finger with swan neck deformity using a modified Spiral Oblique Retinacular Ligament (SORL) reconstruction procedure: A case series and technical note

INTRODUCTION AND IMPORTANCE: Chronic terminal extensor tendon injury produces mallet deformity and secondary swan neck deformity. It can be found in neglect cases and in a failed cases after conservative treatment or primary surgical repair. Surgery is considered in cases with extensor lag of more than 30° and functional deficit. Reconstruction of the spiral oblique retinacular ligament (SORL) has been reported in literatures to correct swan neck deformity by a dynamic mechanical basis. CASE PRESENTATION: Three cases of chronic mallet finger associated with swan neck deformity were treated by the modified technique of SORL reconstruction. Range of motion (ROM) of distal interphalangeal (DIP) joints and proximal interphalangeal (PIP) joints were measured along with the complications. The clinical outcome was reported using the Crawford's criteria. CLINICAL DISCUSSION: All patients had an average age of 34 years (20–54). Average time to surgery was 16.67 months (2–24) and average of DIP extension lag was 66.67°. All patient gave excellent Crawford criteria at the latest follow up (average 15.3 months). The average PIP joint ROM were −1.6(0) (0(0) to −5(0)) of extension and 110(0) (100(0)−120(0)) of flexion for the PIP joint and −1.6(0) (0(0) to −5(0)) of extension and 83.33(0) (80(0)–85(0)) of flexion for the DIP joint. CONCLUSION: We present our technique to manage chronic mallet injury which only utilized two skin incisions and one button at the distal phalanx to minimize risk of skin necrosis and patient discomfort. This procedure can be considered as one of the options for the treatment of chronic mallet finger deformity associated with swan neck deformity.