Retinaculum

Figure 9.2 Posterior tibial tendon released from flexor retinaculum with extensive rupture, scarring, and loss of paratenon.

Initial management should include a trial of anti-inflammatory medication, ankle bracing, and physical therapy. Many diagnostic tests are available. Sobel et al. popularized the peroneal tunnel compression test for longitudinal peroneus brevis tendon tears. This maneuver combines dorsiflexion and eversion of the foot and ankle with manual pressure on the peroneal tendons to elicit a painful response." Plain radiographs may demonstrate bony avulsions of the superior retinaculum or fractures. 

The membranes were tested through a lateral parapatellar skin incision 5-7 cm, followed by incisiOTi of the retinaculum and articular capsule, until the exposure of the knee joint. With the limb in extension the patella was displaced by promoting the exposure of the femoral trochlea (Fig. 21.22a) (lamaguti et al. 2008). 

Fig. 21.22 (a) Dislocation of the patella to expose the trochlear groove, (b) deepening of the groove trochlear with the aid of gouge forceps, (c) fixing the biosynthesized cellulose membrane with 6-0 synthetic absorbable sutures, (d) suturing the joint capsule and retinaculum in type of points of suture, with 3-0 monofilament nylon thread, and (e) suture the skin with simple stitches apart... 

Rupture of the superior peroneal retinaculum, which extends from the lateral aspect of the distal fibular to the calcaneus, may result in peroneal tendon subluxation. Sometimes there is an associated avulsion fracture of the lateral aspect of the distal fibula. Typically, the patient will complain of painful clicking of the ankle, particularly on dorsiflexion and eversion of the foot. The diagnosis is often obvious... 

Diaz GC, van Holsbeeck M, Jacobson JA (1998) Longitudinal split of the peroneus longus and peroneus brevis tendons with disruption of the superior peroneal retinaculum. J Ultrasound Med 17 525-529... 

The quadriceps muscle attaches to the patella via the quadriceps tendon and the retinaculum medially and laterally. They are attached to the tibial tuberosity distally via the patella tendon. They are therefore integral to the stability of the patellofemoral joint. 

Carpal T mnel An internal passage in the wrist between the extensor retinaculum and the carpal bones through which the median nerve, finger flexor tendons, and blood vessels pass from the arm to the hand. 

Striking fusiform enlargement of the median nerve at the distal forearm through the palm, characterized hy an increased hulk of hyperechoic adipose tissue in the epineurium that surrounds and is interposed between normal-appearing fascicles (Fig. 4.5a-d) (Murphey et al. 1999 Chen et al. 1996). At the carpal tunnel level, the affected median nerve may become symptomatic earlier than other nerves due to its encroachment by the flexor retinaculum. In these instances, detection of nerve fascicles that appear focally swollen within the adipose mass indicates compression and the need for carpal tunnel release (Fig. 4.5e-g). Debulking of the mass may compromise the intraneural vasculature causing catastrophic motor and sensory deficits or an intense healing response that may further jeopardize function (Marom and Helms 1999). 

Dynamic US of the elbow can be used to help demonstrate abnormal dislocation of the ulnar nerve, with or without snapping triceps syndrome. This finding typically occurs in the cubital tunnel, an osteofibrous tunnel formed by a groove between the olecranon and the medial epicondyle and bridged by the Osborn retinaculum. As described in Chapter 8, dynamic scanning during full elbow flexion can allow continual depiction of the intermittent dislo-... 

After surgical decompression, the US appearance and mobility of the afferted nerves may improve, and it is possible to visualize the altered morphology of the osteofibrous tunnel after release of the retinaculum (Martinoli et al. 2000b E1-Karabaty et al. 2005). 

Wang XT, Rosenberg ZS, Mechlin MB et al (2005) Normal variants and diseases of the peroneal tendons and superior peroneal retinaculum MR imaging features. RadioGraphics 25 587-602... 

The anconeus epitrochlearis is a small accessory muscle (prevalence ranging from 1% to 34%) that forms the roof of the cubital tunnel, replacing the Osborne retinaculum and joins the posterior aspect of the medial epicondyle with the medial aspect of the olecranon.. This muscle is often bilateral and can cause ulnar neuropathy by occupying space within the cubital tunnel and decreasing its free volume during full elbow flexion. Somewhat equivalent to the anconeus epitrochlearis, an anomalous myotendinous junction of the triceps may also be prominent over the posteromedial side of the cubital tunnel (see Sect. 8.5.4.S). 

Fig. 8.64a,b. Snapping triceps syndrome. Schematic drawings of the posterior aspect of the elbow in a extension and b 90° flexion demonstrate the ulnar nerve (arrows) as it passes through the cubital tunnel and a prominent medial head (mh) of the triceps muscle (tin). Note the absence of the Osborne retinaculum when compared with Fig. 8.7c. With elbow flexion, the medial edge of the triceps (arrowheads) and the ulnar nerve move anterior to the tip of the epicondyle. T, distal triceps tendon /c , flexor carpi ulnaris...

The extensor tendons course over the dorsal aspect of the wrist. They run within series of adjacent osteofi-brous tunnels delimited by depressions of the surface of radius and ulna and by the extensor retinaculum, a 2 cm wide thickening of the dorsal fascia attached to the radial styloid laterally and to the pisiform and triquetrum medially. From the deep surface of the retinaculum, vertical fibrous bands insert into the cortical bones, at both sides of the tendons, dividing the extensor tunnel into six compartments numbered from radial (I) to ulnar (VI). In each compartment, a single synovial sheath formed by visceral and parietal layers surrounds one or more tendons (Fig. 10.2). A variable amount of fatty tissue fills the space between... 

Fig. 10.11 a—c. Extensor tendons first compartment, a Short-axis 15-7 MHz US image obtained over the first compartment of the extensor tendons with b diagram correlation demonstrates the abductor poUicis longus (APL) and extensor pollicis brevis (EPB) tendons which appear closely apposed and retained over the radial styloid by the retinaculum (arrowheads). The radial artery (RA) is seen on the lateral aspect of the abductor pollicis longus. c Probe positioning and field-of-view of the US image relative to the dorsal wrist structures... 

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