PEAK LOAD RESISTANCE OF THE JUGGERKNOT TM SOFT ANCHOR TECHNIQUE COMPARED WITH OTHER COMMON FIXATION TECHNIQUES FOR LARGE MALLET FINGER FRACTURES Jason Pui Yin Cheung, Boris Fung and Wing Yuk Ip Department of Orthopaedics and Traumatology University of Hong Kong Medical Centre Queen Mary Hospital, Hong Kong Received 30 March 2013; Revised 8 May 2013; Accepted 9 May 2013 ABSTRACT Introduction: To identify the strongest peak load resistance among four mallet finger fracture fixation methods (Kirschner wire, pull-out wire, tension-band wiring and the JuggerKnot TM (Biomet) soft anchor fixation). Methods: Fixation techniques were assigned among 24 specimens from six cadaveric human hands in a randomized block fashion. Peak load resistance was tested at 30  , 45  and 60  of flexion of the distal interphalangeal joint. Results: The mean peak load of tension-band wiring was 67.8 N at 60  of flexion which was most superior. The JuggerKnot TM fixation had mean peak loads of 13.35 N (30  ), 22.51 N (45  ) and 32.96 N (60  ). No complications of implant failure or fragmentation of the dorsal fragment was noted. Conclusions: Tension-band wiring was the strongest fixation method but was most prominent on the skin surface as seen in three specimens. The JuggerKnot TM soft anchor fixation had similar peak load resistance as k-wire fixation and pull-out wiring. Keywords : Biomechanics; Mallet Finger; Peak Load; JuggerKnot TM . INTRODUCTION Mallet finger a is due to rupture of the terminal extensor tendon or avulsion fracture of the distal phalanx and the mechanism of injury is often a forceful and sudden flexion force to the fingertip. 1 This injury leads to extension lag of the distal in- terphalangeal joint. Full-time splinting followed by a period of weaning is effective for most simple closed mallet finger in- juries. Surgery is usually reserved for patients who cannot tolerate splinting, those with large avulsion fractures leading to palmar subluxation of the distal phalanx or those with open injuries. 2 , 3 A previous cadaveric study has shown that palmar subluxation of the distal interphalangeal joint only occurs if the avulsed fragment includes more than 43% of the articular surface. 4 Furthermore, this sequelae was consistently seen if more than 52% of the articular surface was involved. 4 There are many fixation techniques described for mallet injuries including extension block technique, 5–9 compression fixation pins, 10 biodegradable arrows, figure of eight wiring, Correspondence to: Dr. Jason Pui Yin Cheung, Department of Orthopaedics and Traumatology, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong. Tel: (þ852) 9300-6845, Fax: (þ852) 2524-7489, E-mail: jcheung98@hotmail.com a Mallet (Baseball) Finger: rupture of the terminal extensor tendon or avulsion fracture of the distal phalanx. Hand Surgery, Vol. 18, No. 3 (2013) 381–388 © World Scientific Publishing Company DOI: 10.1142/S0218810413500433 381 Hand Surg. 2013.18:381-388. Downloaded from www.worldscientific.com by UNIVERSITY OF HONG KONG on 10/28/13. For personal use only.