Popliteal Fossa

Clinical presentation differs according to age. Infants typically have face, trunk, and neck involvement, while older children and adults present with lesions in the antecubital and popliteal fossa and on the hands and face. 

Roussignol X, Bertiaux S, Rahali S, Potage D, Duparc F, Dujardin F (2015) Minimally invasive posterior approach in the popliteal fossa for semitendinosus and gracilis tendon harvesting an anatranic study. Orthop Traumatol Surg Res 101 167-172... 

Franz W, Baumann A (2016) Minimally invasive semitendinosus tendon harvesting from the popliteal fossa versus conventional hamstring tendon harvesting for ACL reconstruction a prospective, randomised controlled trial in 100 patients. Knee 23(1) 106-110... 

Subjective symptoms are always present. Itching, stinging and burning sensations are the usual complaints of many patients, with or without objective signs. In particular, facial complaints are not often accompanied by detectable lesions they correspond to the so-called subjective irritant dermatitis . The eyelids, cheeks, nasal folds and neck are commonly involved. Subjective symptoms may occur on covered parts of the body, mainly in the flexures (axillae, groins, cubital and/or popliteal fossae) but also on the extensor aspects of the limbs or on the trunk. 

For laser EVTA, a 5F sheath is inserted through the entire abnormal segment and into a more central vein. A bare tipped laser fiber is inserted to the end of the sheath, which is then withdrawn exposing the tip of the fiber. The sheath and fiber are then withdrawn to place the tip at the staring point of the ablation. For the GSV this is usually about 1 cm below the SFJ and for the SSV about 2 cm below the SPJ where the SSV turns parallel to the skin just below the popliteal fossa (Fig. 9.2). With the laser, confirmation of the position can be made with localization of the light which comes from the red aiming beam... 

The knee should be palpated and landmarks identified. Swelling may be palpated medial, inferior, or lateral to the patella or in the popliteal fossa. Tenderness detected during palpation may indicate the location of the source of pain, such as over the tibial tuberosity in the case of Os-good-Schlatter disease. 

Tender point lateral and medial attachments of the gastrocnemius muscle In the lower popliteal fossa. 

Nervous system In a retrospective study to analyse the incidence of peripheral neuropathy in 157 patients with continuous sciatic nerve block in the popliteal fossa, three patients with an associated common superficial peroneal and sural nerve injury were identified via clinical and electromyographical studies [21 ]. In 44% percent of the patients US guidance was combined with a nerve stimulator technique. The authors conclude that methodological bias or technical problems (lateral vs posterior approach, US guidance) may account for the higher (1.9%) than average (0-0.5%) rate of peripheral neuropathy. It is of note that anatomically the common superficial peroneal and sural nerves were more affected than the tibial nerve, possibly due to their superficial location. 

The popliteal artery is the direct continuation of the femoral artery. It begins at the adductor hiatus and ends at the inferior edge of the pop-liteus muscle where it divides into the anterior and posterior tibial arteries. In the popliteal fossa. 

Fig. 14.10a-d. Anatomy of the peroneal nerve, a Schematic drawing of a lateral view of the knee illustrates the course of the common peroneal nerve (curved arrows) which branches from the sciatic nerve (black arrow) at the apex of the popliteal fossa and descends posterior to the biceps femoris muscle (Bf) and tendon (asterisk) to turn anteriorly around the fibular head. The nerve then continues down between the lateral side of the neck of the fibula and the peroneus longus muscle (PI). Here the peroneal nerve divides into its two terminal branches, the superficial peroneal nerve (white arrowhead) and the deep peroneal nerve (white arrow), md sends a recurrent articular branch (open arrowhead).b-d Transverse Tl-weighted MR images obtained at the levels indicated in a (horizontal bars) reveal the normal position of the common peroneal nerve (curved arrow) relative to the biceps tendon, the crural fascia (open arrowhead) fibular head (FH). Note the relationships of the main trunk and the superficial (white arrowhead) and deep (white arrow) peroneal nerves with the fibular and neck (FN). Black arrow, tibial nerve... 

The posterior knee is the predominant site for cystic masses (Tschirch et al. 2003). There is some confusion about the correct terminology of popliteal cysts in the radiological and clinical literature. A popliteal cyst can be defined as a cystic lesion located on the posterior aspect of the knee joint, within the popliteal space. In this location, the most common popliteal cysts are Baker cysts. These cysts result from the distension of the semimembranosus-gastrocnemius bursa and are not synonymous with popliteal cysts (Baker 1877). Posterior extra-articular ganglia are rare and may be located anywhere in the popliteal fossa but not at the level of the semimembranosus-gastrocnemius bursa. Differentiation between these two entities is clinically relevant because they have different characteristics, pathogenesis, imaging features and therapeutic implications. 

Fig. 14.87a-c. Fusiform neuroma of the common peroneal nerve in the popliteal fossa. The patient reported sudden onset of nerve deficit a knee sprain, a Longitudinal and b transverse 12-5 MHz US images with c fat-suppresse T2 -weighted MR imaging correlation demonstrate a fusiform hypoechoic swelling of the common peroneal nerve (arrowheads) as a result of a stretching injury in the popliteal fossa. Observe the position of the nerve between the biceps femoris (Bf) and the lateral head of the gastrocnemius (LHG)... 

Fig. 14.88a-c. Complete tear of the common peroneal nerve in a patient with previous knee dislocation, a Long-axis 12-5 MHz US image over the peroneal nerve in the popliteal fossa. The nerve has a wavy course and is characterized by abnormal thickened (arrowheads) and thinned (arrows) segments related to the interruption and laceration of the fascicles, b Transverse oblique 12-5 MHz US image over the lateral knee with c lateral radiographic correlation demonstrates abnormal hypoechoic tissue related to the avulsion of the biceps femoris tendon (arrows) from its insertion (open arrowhead) into the fibular head (FHj.Note the close relationship of the ruptured biceps with the torn nerve (white arrowheads). On the radiograph, a small fleck of bone (curved arrow) appears retracted proximally with the torn biceps tendon... 

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