A Cadaveric Study of the Distal Biceps Femoris Muscle in relation to the Normal and Variant Course of the Common Peroneal Nerve: A Possible Cause of Common Peroneal Entrapment Neuropathy.

Tae Woo Kim,Taeyeong Kim,Jeong-Hyun Park,Jinseo Yang,Suyeon Park,Jaeho Cho,Battur Tsengel,Kwang-Rak Park,Nikolai E. Lazarov

doi:10.1155/2020/3093874

Abstract

The most frequent mononeuropathy in the lower extremity has been reported as the common peroneal nerve entrapment neuropathy (CPNe) around the head and neck of the fibula, although the mechanism of the neuropathy in this area cannot be fully explained. Therefore, the aim of this cadaveric study was to evaluate the relationship between morphologic variations of the distal biceps femoris muscle (BFM) and the course of the common peroneal nerve (CPN) and to investigate the incidence and morphological characteristics of anatomical variations in the BFM associated with CPNe. The popliteal region and the thigh were dissected in 115 formalin-fixed lower limbs. We evaluated consensus for (1) normal anatomy of the distal BFM, (2) anatomic variations of this muscle, and (3) the relationship of the muscle to the CPN. Measurements of the distal extents of the short and long heads of the BFM from insertion (fibular head) were performed. Two anatomic patterns were seen. First, in 93 knees (80.8%), the CPN ran obliquely along the lateral side of the BFM and then superficial to the lateral head of the gastrocnemius muscle. Second, in 22 cases (19.2%), the CPN coursed within a tunnel between the biceps femoris and lateral head of the gastrocnemius muscle (LGCM). There was a positive correlation between the distal extents of the short heads of the biceps femoris muscle (SHBFM) and the presence of the tunnel. The “popliteal intermuscular tunnel” in which the CPN travels can be produced between the more distal extension variant of the SHBFM and the LGCM. This anatomical variation of BFM may have a clinical significance as an entrapment area of the CPN in the patients in which the mechanism of CPNe around the fibula head and neck is not understood.

Highlights

The common peroneal entrapment neuropathy (CPNe) is the most common lower extremity entrapment neuropathy and accounts for 15% of all peripheral entrapment neuropathies [1, 2]
We reviewed an magnetic resonance imaging (MRI) study about an anatomical variation of the distal biceps femoris muscle (BFM) related to the CPNe with a clinical case illustration [14]
The common peroneal nerve (CPN) arises from the sciatic nerve at the upper level of the popliteal fossa and runs obliquely along the medial side of the BFM and superficial to the lateral head of the gastrocnemius muscle (LGCM) (Figure 2)

Summary

Introduction

The common peroneal entrapment neuropathy (CPNe) is the most common lower extremity entrapment neuropathy and accounts for 15% of all peripheral entrapment neuropathies [1, 2]. The common peroneal nerve (CPN) is an important nerve to consider when performing a complete neurologic evaluation in the lower extremity, because it can BioMed Research International FIbH CPN LGCM Distal LHBFM SHBFM Proximal (a) SHBFM LHBFM. The CPN branches from the sciatic nerve, usually arising at the junction of the upper two-thirds and lower third of the posterior compartment of the thigh. It descends obliquely along the posterolateral side of the popliteal fossa to the head of the fibula. The mechanism by which the CPN is compressed in the fibular tunnel could not be clearly explained by any of the researchers, this anatomic location was believed to cause a significant compression of the CPN [8]

Methods

Results

Discussion

Conclusion