Comparison of an All-Inside Suture Technique With Traditional Pull-Out Suture and Suture Anchor Repair Techniques for Flexor Digitorum Profundus Attachment to Bone

PurposeOne goal in repairing zone 1 flexor digitorum profundus (FDP) injuries is to create a tendon-bone construct strong enough to allow early rehabilitation while minimizing morbidity. This study compares an all-inside suture repair technique biomechanically with pull-out suture and double-suture anchor repairs.MethodsRepairs were performed on 30 cadaver fingers. In all-inside suture repairs (n = 8), the FDP tendon was attached to bone with two 3-0 Ethibond sutures and tied over the dorsal aspect of distal phalanx. Pull-out suture repairs (n = 8) were performed with 2-0 Prolene suture and tied over a dorsal button. There were 2 suture anchor repair groups: Arthrex Micro Corkscrew anchors preloaded with 2-0 FiberWire suture (n = 7) and Depuy Micro Mitek anchors preloaded with 3-0 Orthocord suture (n = 7). Repair constructs were tested using a servohydraulic materials testing system and loaded until the repair lost 75% of its strength.ResultsThere were no statistically significant differences in tensile stiffness, ultimate load, or work to failure between the repairs. Failure mode was suture stretch and gap formation greater than 2 mm at the repair site for all pull-out suture repairs and for 7 of 8 all-inside suture repairs. Two of the Arthrex Micro Corkscrew repairs and 5 of the Depuy Micro Mitek repairs failed by anchor pull-out.ConclusionsThis cadaveric biomechanical study showed no difference in tensile stiffness, ultimate load, and work to failures between an all-inside suture repair technique for zone 1 FDP repairs and previously described pull-out suture and suture anchor repair techniques. The all-inside suture technique also has the advantages of avoiding an external button and the cost of anchors. Therefore, it should be considered as an alternative to other techniques.Clinical relevanceThis study introduces a new FDP reattachment technique that avoids some of the shortcomings of current techniques.