CIRCUMFERENTIAL WIRING OF PATELLA MADE EASY

V Lenin Babu and K Baskaran

Background

Circumferential wiring of patella can sometimes be difficult, especially when it comes to threading the Stainless Steel (SS) wire through the soft tissues. The authors have experienced problems using instruments like a wire passer, wide bore white needle and a long spinal needle owing to their size and diameter. We describe the use of PVC wound drain (used in redivac sets) as a simple, fast and safe alternative for threading SS wires through soft tissues while doing the above procedure.

Method

A 4.8 mm diameter round PVC wound drain is used (Figure 1).

Figure 1 PVC wound drain

The SS wire is threaded into the plastic tube before the needle is passed through the soft tissues (Figure 2).

Figure 2 SS wire threaded into the plastic tube

Owing to its larger size and greater length, the direction of the needle can be better controlled and threaded through the soft tissues, so that the sharp end of the needle exits at a site where the next suture is desired (Figure 3).

Figure 3 Needle, with the SS wire inside the plastic tube, threaded through the soft tissues all around the patella.

Tighten the cerclage wire at the conclusion of threading and bury the knot (Figure 4).

Figure 4 Conclusion of threading with the knot buried.

Discussion

There has been little discussion in the literature about the type of instruments used to thread the SS wire through soft tissues while doing a circumferential wiring of the patella. A wire passer, a wide bore white needle (large intracath) or a long spinal needle can be used for threading through the soft tissues [1,2], but the length and diameter of the above instruments can make the situation difficult especially while trying to thread a stiff wire of size 16G or 18G through the sharp end of the needle. Controlling the direction is another problem owing to the small size of the needle. There is also a possibility of the long spinal needle being bent when introducing it through thick muscle bellies and strong tendons. Attempts to thread the wire through the sharp end of the needle can be quite dangerous.

We have found the 4.8 mm diameter round PVC wound drain, which comes as part of the redivac sets (size 14 or 16) quite useful in such situations. The introducer is sharp enough to pierce through any thick muscle bellies/tendons and the length and thickness of the needle allows you to thread it over long distances to the site where the next suture is desired. Even the largest diameter SS wires can be easily threaded all around the patella midway between the anterior and posterior surfaces to keep the fracture lines from opening anteriorly or posteriorly when the cerclage wire is tightened. Since the wire is threaded only through the plastic end of the needle, the chances of needle stick injury are almost negligible. The tube can also be used as a suction drain at the end of the procedure.

References

1) Crenshaw A.H. Campbell's Operative Orthopaedics. 8th edition, Mosby Year Book, 1992; pages 841-847
2) Michael J. Weber, Chet J. Janecki, Paul McLeod, Carl L. Nelson, James A. Thompson. Efficacy of Various Forms of Fixation of Transverse Fractures of the Patella. Journal of Bone and Joint Surgery 1980; 62-A: 215-220