Is Lateral Onset Cross Pin Technique Strong Enough? A Biomechanical Study.

Objectives: It is aimed to compare biomechanically the 3 different pin techniques and the lateral onset cross-pinning (LXP) technique in supracondylar humeral fractures.

Methods: Biomechanical testing was performed on 52 synthetic humeriFour pin configurations techniques were tested: crossed pins (XP), 2 lateral pins (2LP), 3 lateral pins (3LP), and LXP technique. Biomechanical testing was performed on Shimadzu Autograph measuring machine. Each pin configuration was tested in a total of 13 humeri: 4 in varus bending, 4 in valgus bending, and 5 in flexion bending. Displacement (mm), and load (N) data were sampled at 10 Hz during each test.

Results: Varus values were statistically lower in 2 LP group comparing to XP, 3 LP, LXP groups (p=0.01, p=0.02, p=0.012, consequently). Flexion load values statistically lower in 2 LP group comparing to XP, 3 LP, LXP groups (p=0.03, p=0.001, p=0,031, consequently). There was no difference between the groups in terms of valgus values (p>0.05).

Conclusion: LXP technique is biomechanically similar to the traditional XP technique. In situations where orthopedic surgeons choose to use medial pins in addition to lateral pins such as distal humerus fractures with medial-sided defects.