The lateral retromalleolar groove; a cadaveric study using 3D imaging modality (Rhinoceros software)

Introduction

Peroneal tendon subluxation & dislocation is a rare phenomenon. It is a commonly misdiagnosed cause of lateral ankle pain and instability.

Aim(s)

Our aim was to establish the morphometric (quantification of components) features of retromalleolar fibular groove in cadavers using 3D technique.

Study points

1. To map the version and inclination based on the 3D techniques

2. To determine the depth of peroneal groove sufficient to prevent subluxation of tendons

Method/materials

We used 12 of embalmed lower extremities. 6 males and 6 females. All were Caucasians (Age: 61–94).

The orientation is calculated using the cartilage boundary of the peroneal groove and using the centroid of the curved surface of the groove.

We used rhinoceros software for data collection and mapping of peroneal grooves using 3D imaging Microscribe Digitiser.

Results

The retromalleolar groove was concave in 8 ankles. Flat in 3 (female 50%) and Convex in 1 (female) ankle. Differences in length/Width/Depth of the retrotrochlear groove are as follows:

1. Male: Length 6.2 cm, width 5.4 mm, depth 2.2 mm

2. Female: Length 5.3 cm, width 4.5 mm, depth 0.1 mm

3. The deepest part of groove was 2.4 cm from tip of fibula (1.3–3.7 cm)

4. The length of deepest part was 1.9 cm (1.4–2.6)

Conclusion

1. •

   Three distinct morphological variations

2. •

   In females; the most frequent is flat variety

3. •

   The deepest part of groove was 2.4 cm from tip of fibula

4. •

   The length of deepest part was 1.9 cm which corresponds with musculo-tendinous junction of peroneus brevis.

Clinical relevance

Knowledge of peroneal groove geometry in operative treatment of peroneal tendon subluxation (PTS) is important for a good functional outcome. Orientation of the peroneal groove component may be critical in the operative success.