Countersinking of intramedullary pins is occasionally required in femoral, tibial, and humeral fractures to minimize morbidity due to joint interference or soft tissue impingement, most notably sciatic nerve irritation dorsal to the trochanteric notch. This procedure is traditionally done with a mallet and a pointed countersink, similar to a carpenter’s tool, which is placed against the end of the intramedullary pin. Difficulty visualizing the pin end in soft tissues and oblique or irregular (cut) ends of the intramedullary pin can make this a frustrating exercise. Small diameter pins may be inadvertently bent if struck slightly off-axis, and confirmation of satisfactory depth can be difficult, particularly in the trochanteric fossa of the femur.
An IMEX® drill sleeve and Interface® no-point pin of appropriate size can be used to simplify the process, at least for IM pins of the appropriate diameter:
IM Pin 5/64" | Drill Sleeve Size 2.0mm | Interface® No-Point Pin Size Mini 2.0mm or 5/64"
IM Pin 3/32" | Drill Sleeve Size 2.3mm | Interface® No-Point Pin Size Small 2.4/3.2mm (3/32" / 1/8")
IM Pin 1/8" | Drill Sleeve Size 3.1mm | Interface® No-Point Pin Size Medium 3.2/4.0mm (1/8" / 5/32")
IM Pin 5/32" | Drill Sleeve Size 3.9mm | Interface® No-Point Pin Size Large 4.0/4.8mm (5/32" / 3/16")