History and Physical Examination

Tendinopathy of the peroneal tendons often coexists with a lateral ankle sprain, and the diagnosis of peroneal tendon pathology in a patient with lateral ankle pain can be difficult.¹⁵ The anterior drawer test and varus stress test are applied routinely to detect laxity of the ankle ligaments. In acute cases, the detailed history should include reconstruction of the trauma mechanism. The presence of associated conditions such as rheumatoid arthritis, psoriasis, hyperparathyroidism, diabetic neuropathy, calcaneal fracture, fluoroquinolone use, and local steroid injections is important, because they can increase the degree of peroneal tendon dysfunction.¹⁶ The differential diagnosis includes fatigue fractures or fractures of the fibula, posterior impingement of the ankle, and lesions of the lateral ligament complex. Post-traumatic or postoperative adhesions and irregularities of the posterior aspect of the fibula (i.e., peroneal groove) also can be responsible for symptoms in this region.

Patients with tendinopathy have crepitus and recognizable tenderness over the tendons on palpation. Swelling, tendon dislocation, and signs of tenosynovitis can be found at the lateral aspect of the posterior ankle.

Patients with peroneal tendon dislocation typically complain of lateral instability, giving way, and sometimes a popping or snapping sensation over the lateral aspect of their ankle. On physical examination, the tendons can be subluxated by active dorsiflexion and eversion, which provokes the pain.¹⁷

Diagnostic Imaging

If the Ottowa ankle rules do not indicate abnormalities, applying diagnostics in the acute phase after an inversion trauma should be questioned. However, when peroneal tendon pathology is suspected, additional diagnostics should be applied, and when posterolateral ankle pain persists after the initial trauma, diagnostic imaging should be considered. Routine weight-bearing radiographs in the anteroposterior and lateral directions are advised in these cases to rule out avulsion fractures, spurs, calcifications, or ossicles.

Peroneal tendon dislocation is a clinical diagnosis, and it is frequently accompanied by a tendon rupture. Additional investigations such as magnetic resonance imaging (MRI) and ultrasonography may be helpful in diagnosing partial tears of the tendon of peroneus brevis or longus.¹⁸ Both modalities are considerably accurate and precise, although ultrasonography is more cost effective.¹⁹

Conservative Management

Conservative management should be attempted first. This includes activity modification, footwear changes, temporary immobilization, and corticosteroid injections. Lateral heel wedges can take the strain off the peroneal tendons, which may allow healing.¹⁶

Surgical Technique

The patient is placed in the lateral decubitus position. Alternatively, the patient can be placed in the supine position with the foot in endorotation. A support can be placed under the leg, allowing the ankle to be moved freely. Before anesthesia is administered, the patient is asked to evert the foot so that the peroneal tendons can be visualized clearly. Their course is drawn on the skin, and the locations of the portals are marked (Fig. 16-1). The surgery can be performed under local, regional, epidural, or general anesthesia. After exsanguination, a tourniquet is inflated around the thigh of the affected leg.

FIGURE 16-1 The patient is placed in the lateral decubitus position. Alternatively, the patient can be placed in the supine position with the foot in endorotation. A support can be placed under the leg, allowing the ankle to move freely. The patient is asked to evert the foot, which usually allows the peroneal tendons to be visualized clearly. Its course is drawn on the skin (white line), and the location of the portals is marked (black areas).

A distal portal is made 2 to 2.5 cm distal to the posterior edge of the lateral malleolus. An incision is made through the skin, and the tendon sheath is penetrated with an arthroscopic shaft with a blunt trocar. A 2.7-mm, 30-degree arthroscope is then introduced.

The inspection starts approximately 6 cm proximal to the posterior tip of the fibula, where a thin membrane splits the tendon compartment into two separate tendon chambers. More distally, the tendons lie in one compartment. A second portal is made 2 to 2.5 cm proximal to the posterior edge of the lateral malleolus under direct vision by placing a spinal needle directly over the tendons (Fig. 16-2). Through the distal portal, a complete overview of both tendons can be obtained.

FIGURE 16-2 A, Peroneal tendoscopic image shows a left ankle with the arthroscope in the distal portal, and both tendons are clearly visualized. Peroneus longus tendon (1), peroneus brevis tendon (2), tendon sheath (3). B, Peroneus longus tendon (1), peroneus brevis tendon (2), tendon sheath (3), the location of the proximal portal is determined under direct vision with a spinal needle (4). C, Peroneus longus tendon (1), peroneus brevis tendon (2), tendon sheath (3), the definite portal is created with a retrograde knife directly over the tendons (5).

By rotating the arthroscope over and between both tendons, the entire compartment can be inspected (Fig. 16-3). When a total synovectomy of the tendon sheath has to be performed, it is advisable to make a third portal more distal or more proximal than the portals described previously. When a rupture of one of the tendons is seen, endoscopic synovectomy is performed, and the rupture is repaired through a mini-open approach.

FIGURE 16-3 A 28-year-old woman with persistent pain over the peroneal tendons behind the lateral malleolus of the left ankle did not respond to conservative treatment. Magnetic resonance imaging did not show a partial-length rupture of the tendons. Excessive fluid was present in the tendon sheath. Immunohistopathologic examination of the loose body showed giant cell proliferation. A, The tendoscopic image shows the peroneal tendon. Inside the tendon sheath, a calcified deposit recognized (1, peroneal tendon; 2, semi-loose body; 3, tendon sheath). B, By changing the visualization angle, the loose body is more clearly visualized. It has partially been detached from the tendon sheath (1, peroneal tendon; 2, semi-loose body; 3, tendon sheath; 4, probe).

In patients with recurrent dislocation of the peroneal tendon, endoscopic fibular groove deepening can be performed through this tendoscopic approach. It is a time-consuming procedure because of the limited working area. Groove deepening is performed from within the tendon sheath, with the risk of iatrogenic damage to the tendons. We therefore prefer an approach based on the two-portal hindfoot technique, with an additional portal located 4 cm proximal to the posterolateral portal.²⁰

At the end of the procedure, the portals are sutured to prevent sinus formation, and a compressive dressing is applied. Antibiotics are not routinely given.

History and Physical Examination

In the early stage of dysfunction, patients complain of persistent ankle pain medially along the course of the tendon, fatigue, and aching on the medial plantar aspect of the ankle. Tenosynovitis commonly is associated with swelling.^23,25 A typical observation is abnormal wear of the medial sides of the shoes. Walking increases pain, and participation in sports activities becomes difficult.

Careful clinical examination is important, and both feet should be examined. Valgus angulation of the hindfoot is frequently seen with accompanying abduction of the forefoot (i.e., too many toes sign).²³ The sign is positive when inspecting the patient’s foot from behind; in the case of significant forefoot abduction, three or more toes are visible lateral to the calcaneus, whereas normally, only one or two toes are seen. With the patient seated, the strength of the tendon and location of pain are evaluated by asking the patient to invert the foot against resistance (Fig. 16-4).

FIGURE 16-4 Before anesthesia is administered, the patient is asked to actively invert the affected foot so the tendon can be palpated. Its location is drawn onto the skin for preparing the location of the portals.

Intra-articular lesions such as a posteromedial impingement syndrome, subtalar pathology, calcifications in the dorsal capsule of the ankle joint, loose bodies, or osteochondral defects should be excluded. Entrapment of the posterior tibial nerve in the tarsal canal is commonly known as a tarsal tunnel syndrome. Clinical examination is normally sufficient to adequately differentiate these disorders from an isolated posterior tibial tendon disorder.

Diagnostic Imaging

After initial history taking and physical examination, the diagnosis can be confirmed or rejected using radiography. Conventional radiographs may show abnormal alignment such as flattening of the plantar arch or bony changes such as irregularity and hypertrophic change at the navicular attachment, providing an important clue to long-standing problems with the posterior tibial tendon.²⁶ However, pathology of this soft tissue structure is easier to identify using ultrasound or MRI. Ultrasound imaging is a cost-effective and accurate method for evaluating disorders of the posterior tibial tendon.²⁷ Thickening of the tendon or peritendinous soft tissue, hypoechoic texture, ill-definition of the fibrillar pattern, associated hypervascularity on color Doppler, thinning, splitting, and rupture may be useful clues.²⁶ In our practice, MRI is the method of choice because the images can be interpreted by the orthopedist, in contrast to ultrasound images, and it is therefore more helpful for preoperative planning. It is also considered the gold standard for assessing tibialis posterior dysfunction and related soft tissue injuries.²⁶ A major advantage is the ability to detect bony edema. Findings may include fluid or synovitis around the tendon, hypertrophy of the tendon, intrasubstance tears showing increased signal intensity, longitudinal tears, and complete tendon tears.²⁶

Conservative Management

Initially, conservative management is indicated, with rest combined with nonsteroidal anti-inflammatory drugs (NSAIDs), immobilization using a plaster cast or tape, or orthotic shoe modifications. There is no consensus about whether to use corticosteroid injections, and cases of tendon rupture after corticosteroid injections have been described.²⁸

Surgery is indicated if conservative management for 3 to 6 months does not resolve the complaints.²⁹ It can be performed by an open or endoscopic procedure. An open synovectomy is performed by sharp dissection of the inflamed synovium while preserving the blood supply to the tendon. Postoperative management consists of plaster cast immobilization for 3 weeks, with the possible disadvantage of formation of new adhesions, followed by wearing a functional brace with controlled ankle movement for another 3 weeks and physical therapy.

Endoscopic synovectomy is indicated when access allows radical removal of inflamed synovium.³⁰ Several published studies have described successful endoscopic synovectomy and the advantages related to minimally invasive surgery.^9,31,32

Surgical Technique

The procedure can be performed on an outpatient basis under local, regional, or general anesthesia. The patient is placed in the supine position. A tourniquet is placed around the upper leg. Before anesthesia, the patient is asked to actively invert the foot, so that the posterior tibial tendon can be palpated and the portals can be marked. Access to the tendon can be obtained anywhere along its course.

We prefer to make the two main portals directly over the tendon: 2 to 3 cm distal and 2 to 3 cm proximal to the posterior edge of the medial malleolus (Fig. 16-5). The distal portal is made first; the incision is made through the skin, and the tendon sheath is penetrated by the arthroscopic shaft with a blunt trocar. A 2.7-mm, 30-degree arthroscope is introduced, and the tendon sheath is filled with saline. Irrigation is performed using gravity flow.

FIGURE 16-5 The patient is in the supine position. The two main portals (black areas) are made directly over the posterior tibial tendon (white lines) 2 to 3 cm distal and 2 to 3 cm proximal to the posterior edge of the medial malleolus.

Under direct vision, the proximal portal is made by introducing a spinal needle, and an incision is made into the tendon sheath. Instruments such as a retrograde knife, a shaver system, blunt probes, and scissors can be used. For synovectomy in patients with rheumatoid arthritis, a 3.5-mm shaver can be used. The complete tendon sheath can be inspected by rotating the arthroscope around the tendon. Synovectomy can be performed with a complete overview of the tendon from the distal portal over the insertion of the navicular bone to approximately 6 cm above the tip of the medial malleolus.

While inspecting the tendon sheath, special attention should be given to the posterior aspect of the medial malleolar surface and the posterior ankle joint capsule. The tendon sheath between the posterior tibial tendon and the flexor digitorum longus is relatively thin, and inspection of the correct tendon should always be checked. This can be accomplished by passively flexing and extending the toes; if the tendon sheath of the flexor digitorum longus tendon is entered, the tendon will move up and down.

When remaining in the posterior tibial tendon sheath, the neurovascular bundle is not in danger. When a rupture of the posterior tibial tendon is seen, endoscopic synovectomy is performed (Fig. 16-6),and the rupture is repaired through a mini-open approach. Magnifying the tendon endoscopically enhances localization and extent of the rupture, and it minimizes the incision required for repair. At the end of the procedure, the portals are sutured to prevent sinus formation.

FIGURE 16-6 A 48-year-old woman had persistent pain over the posterior tibial tendon of the left foot. She sustained direct trauma to the posterior tibial tendon 1 year earlier. Physical examination revealed a normal range of motion, no signs of tendon insufficiency, but pain and swelling over the posterior tibial tendon just behind the medial malleolus. A, The tendoscopic image shows the arthroscope in the anterolateral portal looking proximally (1, posterior tibial tendon; 2, tendon sheath; 3, arthroscopic probe; 4, tear in posterior tibial tendon). B, The image shows a partial-length rupture (4) of the posterior tibial tendon (1). Repair of the rupture was performed through a mini-open repair (2, tendon sheath; 3, arthroscopic probe).

History and Physical Examination

Patients typically complain of pain located at the posteromedial aspect of the ankle that worsens with ankle motion and hallux dorsiflexion and that diminishes at rest. The tendon can be palpated behind the medial malleolus at the level of the subtalar joint. Asking the patient to repetitively flex the big toe with the ankle in 10 to 20 degrees of plantar flexion increases the ability to palpate the tendon in its gliding channel. This maneuver also differentiates the FHL from posterior tibial tendon pathology. The FHL tendon glides up and down under the palpating finger of the examiner. In the case of stenosing tendinitis or chronic inflammation, crepitus and recognizable tenderness can be provoked. In some patients, a nodule can be palpated moving up and down with active movement of the great toe.

In patients with associated posterolateral ankle pain, a posterior impingement syndrome must be ruled out by means of a hyper-plantar flexion test (Fig. 16-7). The forced passive hyper-plantar flexion test result is positive when the patient experiences recognizable posterior ankle pain. A negative test result rules out a posterior ankle impingement syndrome. A positive test result is followed by a diagnostic infiltration of lidocaine in the posterior ankle compartment. Disappearance of pain after infiltration confirms the diagnosis.

FIGURE 16-7 The forced hyper-plantar flexion test is performed with the patient sitting with the knee flexed in 90 degrees. The test is performed with repetitive, quick, passive hyper-plantar flexion movements. The test can be repeated in slight external rotation or slight internal rotation of the foot relative to the tibia. The investigator can apply this rotational movement on the point of maximal plantar flexion (arrow), thereby “grinding” the (enlarged) posterior talar process or os trigonum in between tibia and calcaneus.

Diagnostic Imaging

After performing a thorough history and physical examination, the diagnosis can be confirmed or rejected by the use of available imaging techniques. If the history and physical examination do not reveal abnormalities, additional diagnostics can be used to search for or to rule out pathology (i.e., for medicolegal reasons). Close consultation between the orthopedic surgeon and the radiologist is necessary to decide on optimal radiographic diagnostics.⁴⁸

In patients without a history of trauma but with isolated, recognizable posteromedial ankle pain during flexion of the great toe while palpating the tendon at the level of the gliding channel, no additional diagnostic tests are needed. If conservative treatment options fail, intervention demands a release regardless of the pathology. MRI can be valuable to rule out tendon ruptures.

For patients with posteromedial ankle pain associated with a positive hyper-planter flexion test result, standard weight-bearing radiographs must be obtained with anteroposterior and lateral views. If differentiation of hypertrophy of the posterior talar process from an os trigonum is difficult, a lateral hindfoot radiograph with the foot in 25 degrees of exorotation in relation to the standard lateral ankle is advised (Fig. 16-8).⁴⁹ For ballet dancers, a lateral radiograph with the foot in maximal plantar flexion can be useful to determine whether a bony posterior ankle impingement is present. In post-traumatic cases, spiral computed tomography (CT) can help to ascertain the extent of the injury or location of the osteochondral defect and the exact location of calcifications or fragments.

FIGURE 16-8 A 27-year-old man presented with posterior left ankle pain during plantar-flexed movements of the foot. The hyper-plantar flexion test result was positive. A, The standard lateral radiograph shows a possible prominent posterior talar process (arrow). B, The lateral radiograph with the foot in 25 degrees exorotation allows an os trigonum to be more easily recognized (arrow).

Conservative Management

Nonoperative treatment options include rest, activity modification, ice therapy, NSAIDs, and physical therapy, such as stretching exercises.^35,36 Infiltration of a corticosteroid around the tendon at the level of the tunnel can be performed as a next step. Avoid iatrogenic neurovascular bundle and tendon lesions.

Conservative treatment options often do not completely resolve the complaints. An active professional ballet dancer with a competitive attitude is not likely to remain inactive for several months, and in these cases, release of the tendon and resection of the posteriorly located bony or soft tissue impediment is indicted.

Posterior Ankle Arthroscopy

The procedure is carried out as outpatient surgery under general anesthesia or spinal anesthesia. The patient is placed in a prone position. The involved leg is marked with an arrow to avoid surgery on the wrong side. A tourniquet is inflated around the thigh for hemostasis. A small support is placed under the lower leg, making it possible to move the ankle freely (Fig. 16-9). We use a soft tissue distraction device when indicated.⁵⁰

FIGURE 16-9 For posterior ankle arthroscopy, the patient is placed in a prone position. A tourniquet is applied around the upper leg (2), and a small support is placed under the lower leg (1), making it possible to move the ankle freely. A support is placed at the ipsilateral side of the pelvis to safely rotate the operating table slightly when needed (3).

Normal saline or lactated Ringer’s solution is used. A 4.0-mm arthroscope with an inclination angle of 30 degrees is routinely used for posterior ankle arthroscopy.

The anatomic landmarks on the ankle are the lateral malleolus, medial and lateral border of the Achilles tendon, and the foot’s sole. The ankle is kept in a neutral, 90-degree position. An endoscopic probe can be used to determine the exact location of the posterolateral portal. The hook is secured under the tip of the lateral malleolus. The hook is placed parallel to the foot’s sole (with the foot in a 90-degree position). A straight line is drawn from the tip of the lateral malleolus to the Achilles tendon, parallel to the sole.

The posterolateral portal is made just above the line from the tip of the lateral malleolus and 1 cm anterior to the Achilles tendon (Fig. 16-10). After making a vertical stab incision, the subcutaneous layer is split by a mosquito clamp. The mosquito clamp is directed anteriorly, pointing toward the interdigital web space between the first and second toes. When the tip of the clamp touches the bone, it is exchanged for a 4.5-mm arthroscopic shaft, with the blunt trocar pointing in the same direction. By palpating the bone in the sagittal plane, the level of the ankle joint and subtalar joint can often be distinguished, because the prominent posterior talar process or os trigonum can be felt as a posterior prominence in between the two joints. The trocar is situated extra-articularly at the level of the ankle joint. The trocar is exchanged for the 4-mm arthroscope with the direction of view 30 degrees to the lateral side.

FIGURE 16-10 For marking the anatomic landmarks that are needed for portal placement, the ankle is kept in a neutral, 90-degree position. An endoscopic probe can be used to determine the exact location of the posterolateral portal. The hook is secured under the tip of the lateral malleolus. The hook is placed parallel to the foot sole, with the foot in a 90-degree position. A straight line is drawn from the tip of the lateral malleolus to the Achilles tendon, parallel to the foot’s sole. The posterolateral portal (arrow) is made just above the line from the tip of the lateral malleolus and 1 cm anterior to the Achilles tendon.

The posteromedial portal is made at the same level, just above the line of the tip of the lateral malleolus but just anterior to the medial aspect of the Achilles tendon (Fig. 16-11). After making a vertical stab incision, a mosquito clamp is introduced and directed toward the arthroscope shaft in a 90-degree angle. When the mosquito clamp touches the shaft of the arthroscope, the shaft is used as a guide to “travel” anteriorly in the direction of the ankle joint, all the way down while contacting the arthroscope shaft until it reaches the bone. The arthroscope is pulled slightly backward, sliding over the mosquito clamp until the tip of the mosquito clamp comes into view. The clamp is used to spread the extra-articular soft tissue in front of the tip of the lens. When scar tissue or adhesions are present, the mosquito clamp is exchanged for a 5-mm bone-cutter shaver. The tip of the shaver is directed in a lateral and slightly plantar direction toward the lateral aspect of the subtalar joint.

FIGURE 16-11 The posteromedial portal (arrow) is located at the same level as the posterolateral portal and just anterior to the Achilles tendon. An imaginary line can be drawn from the level of the posterolateral portal over the Achilles tendon to determine the location of the posteromedial portal.

The joint capsule and fatty tissue overlying the posterolateral aspect of the subtalar joint are removed, and the posterior compartment of the subtalar joint is inspected. At the level of the ankle joint, the posterolateral talar prominence and the PTFL are recognized. Just proximal to the PTFL, the intermalleolar ligament, or tibial slip, is recognized, and more proximal and deeper, the tibiofibular ligament can be assessed. The cranial part of the posterior talar process is freed from scar tissue, and the medial side the FHL tendon is identified.

Removal of a symptomatic os trigonum, a fracture nonunion of the posterior talar process, or a symptomatic, large, posterior talar prominence involves partial detachment of the PTFL, detachment of the talocalcaneal ligament, and a release of the flexor retinaculum. All of these structures attach to the posterior talar prominence or os trigonum. After releasing these structures, the os trigonum can be detached with a chisel or small osteotome and removed with a grasper.

In the case of isolated tendinitis of the FHL tendon, the flexor retinaculum can be released by detaching it from the posterior talar process or os trigonum with an arthroscopic punch. Subsequently, the tendon sheath can be opened distally up to the level of the sustentaculum tali. The tendon sheath can be entered with the scope, allowing accurate tendon inspection and, if necessary, a further release can be performed (Fig. 16-12). Partial-thickness longitudinal tears are débrided. The proximal part of the tendon and the distal part of the muscle belly are inspected and débrided if inflamed, thickened, or if nodules are present. Adhesions and excessive scar tissue are removed.

FIGURE 16-12 A 23-year-old, female ballet dancer presented with posteromedial left ankle pain that occurred during plié and relevé. On active flexion of the great toe, palpation just behind the medial malleolus over the flexor hallucis longus tendon elicited tenderness. A painful nodule could be palpated to move up and down at the level of the flexor retinaculum. Magnetic resonance imaging confirmed flexor hallucis longus tendinitis with local swelling of and fluid around the tendon. A, Endoscopic image displays stenosing flexor hallucis longus tenosynovitis (3). The flexor hallucis longus tendon is located just medial to the posterolateral talar process (1) and is fixed by the flexor retinaculum (2) between the posteromedial and posterolateral talar processes. B, By passive maximal dorsiflexion of the great toe, the muscle belly becomes entrapped behind inside the retinaculum in the tunnel. C, The flexor retinaculum is released by means of a punch. D, The endoscopic image shows complete release of the flexor hallucis longus tendon. E, It is possible to enter the tendon sheath distally with the arthroscope to inspect the tendon up to the level of the sustentaculum tali. Further release of the tendon sheath up to this level can be performed, when indicated.

By applying manual distraction to the calcaneus, the posterior compartment of the ankle opens up, and instruments can be introduced. We prefer to apply a soft tissue distractor at this point.⁵⁰ When indicated, a synovectomy or capsulectomy, or both, can be performed. The talar dome can be inspected over almost its entire surface along with the complete tibial plafond. Osteochondral defects can be débrided, and drilling or microfracture can be performed.

Bleeding is controlled by electrocautery at the end of the procedure. To prevent sinus formation, the skin incisions are closed with 3-0 nylon suture. The incisions and surrounding skin are injected with 10 mL of a 0.5 % bupivacaine/morphine solution. A sterile compressive dressing is applied. Prophylactic antibiotics are not routinely given.