Short cephalomedullary nail toggle: a closer examination.

Area of Science:

• Orthopedic surgery
• Trauma surgery
• Biomechanical engineering

Background:

• Undersized short nails in wide femoral canals can lead to instability and loss of reduction.
• Nail toggle, pivoting around the distal screw, is a potential complication.
• Varus collapse is a concerning outcome following intertrochanteric fracture fixation.

Purpose of the Study:

• Identify risk factors for nail toggle in short cephalomedullary nails (CMN).
• Determine the association between nail toggle and subsequent varus collapse in intertrochanteric fractures.

Main Methods:

• Retrospective cohort study of 71 patients with intertrochanteric fractures treated with short CMNs.
• Radiographic analysis of nail toggle and varus collapse.
• Evaluation of risk factors including demographics, fracture type, reduction quality, Dorr type, nail/canal ratio, lag screw engagement, and tip-apex distance (TAD).

Main Results:

• Shorter TAD and smaller nail/canal ratio were significant risk factors for increased nail toggle.
• Patients with >4 degrees of nail toggle exhibited smaller nail/canal ratios, more Dorr C fractures, less lateral cortex lag screw engagement, shorter TAD, and greater varus collapse.
• A significant association was found between increased nail toggle and increased varus collapse.

Conclusions:

• A lower nail fill percentage and shorter TAD are identified as key risk factors for nail toggle with short CMNs.
• Increased nail toggle is directly associated with a higher incidence of varus collapse.
• These findings highlight the importance of optimal nail selection and placement for stable fixation.