Mini SK™ Linear Distraction / Compression Body
Part Number 307.999

Over the years, IMEX™ has produced a number of prototype
distraction/compression units. Typical requests were for either distraction osteogenesis or acute fracture reduction. The most common application was inclusion in type II fixators for repair of radial growth deformities with need for lengthening in addition to angular deformity correction. Early models were based around the then popular KE device. With the inherent weakness of KE rods, these devices frequently did not have enough strength to provide adequate stability. Use of larger rods solved many stability issues but required custom clamps since KE clamps were incompatible with the newer rods. With the availability of the SK™ ESF System by IMEX™, stronger rods are now a standard as are SK™ clamps that function with these rods. Larger rods have supported a renewed interest in a linear distraction/compression device. Our most recent version is now offered as a standard item in two sizes. It functions in the same fashion as a turnbuckle system and is designed as a modular component of the SK™ external fixator.

The mini distractor/compressor features a single length choice of left and right-hand modified hybrid rods, which are cut to the final desired length to provide a custom fit assembly. The standard mini hybrid rod can also function with the mini assembly. All rod components of the mini unit feature a 0.7mm thread pitch, resulting in 1.4mm of compression or distraction for each turn of the distraction body. A 7mm wrench is used with the mini body and mini SK™ ESF clamps. Overall length of the mini distraction/compression body is 23mm and approximately 6mm of compression or distraction can be obtained without repositioning rods.

In using the assembly as a distraction device, both rods are started near the middle of the body. If compression is the desired use, both rod ends are started closer to their respective body end. Distraction or compression can be achieved by turning the body with an 7mm wrench after fixator clamps and pins have been applied. The body is clearly etched to indicate the turn direction for either compression or distraction (“C” or “D”.) Do not allow the rods to be distracted too near the end of the body or be pushed out of the body when utilizing for distraction. Small windows in the body allow visualization of rod positions.

PART NO.	description
307.999	Mini SK™ Linear Distraction / Compression Body
307.070L	1/8" (3.2mm) Stainless Steel Left-Handed Rod, 70mm
307.090	1/8" (3.2mm) Stainless Steel Right-Handed Rod, 90mm

Threaded portions of the rods are not locked into the holes; therefore, potential for rotational instability exists when used as a unilateral frame. In cases to date, unilateral frame lengthening applications have incorporated an IM rod. Torsional instability does not seem to be an issue with bilateral frames. Uses to date include: femoral and humeral lengthening over nail, radial lengthening with type II or type I-b ESF frame, acute fracture distraction and creative incorporation into circular ESF frames. This device does not provide the control and flexibility of a circular ESF frame but may be useful in less demanding situations.

Potential complications include all linear ESF frame complications plus potential instability, breakage of hybrid rods at threads and all complications typically associated with distraction osteogenesis.