Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Arthroplasty - Knee
Abstract number: 26228
THE COMMON PERONEAL NERVE - CADAVERIC MAPPING AND INJURY RISK
DURING KNEE SURGERY
Prakash JAYAKUMAR, Saket TIBREWAL, Nikos ANTONAKOPOULOS, Sunil
KUMAR
Queens Hospital Romford, Romford (UNITED KINGDOM)
Introduction: Common peroneal nerve (CPN) injury is reported in association with
tourniquet use and intra-operative techniques during total knee arthroplasty (TKA).
Isolated extensor hallucis longus (EHL) palsy has not been described in this
scenario. In the leg, the deep peroneal nerve (DPN) supplies muscular branches to
tibialis anterior (TA), extensor digitorum longus (EDL), peroneus tertius (PT), EHL
and articular branches to the ankle. The precise divisions, relations to the knee joint
and motor end-points are unknown. We highlight 2 cases of isolated EHL palsy post-
TKA and define a map of the DPN. Methods: Two cases of isolated EHL palsy were
confirmed clinically with electromyography. Case notes were analysed. 26 cadavers
were subsequently dissected to determine the anatomy of the DPN and relations to
skeletal landmarks. Results: The DPN originates at the CPN bifurcation between the
fibula and upper peroneus longus passing infero-medially, deep to EDL, close to the
anterior surface of the interosseous membrane and anterior tibial artery. Multiple
motor end points to TA were observed. The majority of nerves to EDL, PT and EHL
had single motor end points. The nerve to EHL arose as close as 2.7 cm from the tip
of the fibula head (2.7-8.3 cm). Discussion: The nerve to EHL is at potential risk
during intra-operative manoeuvers during TKA. Neuropraxia-type traction injuries are
described. The DPN and proximal branches to TA are also at risk but benefit from
tendinous cover and multiple motor end points respectively.
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