Phlegmon of the foot

Phlegmon of the foot is a purulent process, purulent inflammation of the tissues of the fingers is traditionally called an abscess.

ICD-10 code

L.03.0. Phlegmon of the foot

What causes foot phlegmon?

The entry gates of infection are defects of the skin, which usually occur after various mechanical damages to the skin. These can be pricks and cuts, abrasions (long-term traumatic impact of tight shoes in combination with increased humidity from sweat), as well as damage to the epidermis in the deep folds between the toes, caused by a fungal infection. Further development and spread of the infection depends on the pathogenicity of the microflora, the body's resistance and the anatomical features of the damaged area.

Most often, foot phlegmon is caused by staphylococci, much less often by streptococci, pseudomonas and Escherichia coli, and Proteus. Mixed microflora is detected in 15% of observations. The pathomorphology and pathophysiology of the process are directly related to the anatomy of the area and the pattern of infection spread to adjacent anatomical zones.

Anatomy

Anatomically, the foot is divided into three sections: the tarsus, metatarsus, and phalanges of the toes. In clinical practice, it is also conventionally divided into three sections: the front, middle, and back.

The anterior section unites the phalanges of the fingers and the metatarsal bones; the middle section unites the navicular, cuboid and cuneiform bones; the posterior section unites the talus and calcaneus bones.

The bones of the middle section participate in the formation of three functionally important joints: the talocalcaneonavicular, the calcaneocuboid, and the scapho-cuneiform. The articular lines of the talocalcaneonavicular and calcaneocuboid joints have the appearance of a horizontally inverted figure eight. The cavities of these joints are completely isolated, but in surgery, during disarticulation operations, they are conventionally taken for one joint and are called Chopart's. The key to the Chopart joint is a powerful bifurcation ligament located between its two components.

Slightly distal, the navicular bone together with the three cuneiform bones forms a joint communicating with the cuneocuboid and tarsometatarsal joints. The border between the anterior and middle sections is the tarsometatarsal or Lisfranc joint. The key of the Lisfranc joint is a strong ligament located between the medial cuneiform and the second metatarsal bones. The intersection of the key ligaments is the determining moment of the disarticulation operations.

The dorsal fascia is located under the skin of the dorsal side. It continues the fascia of the leg and is attached to the first and fifth metatarsal bones. The deep fascia covers the metatarsal bones and the dorsal interosseous muscles. Between the dorsal and deep fascia is the fascial space of the dorsum, which contains the tendons of the extensor muscles, vessels and nerves. The tendons of the extensor muscles have their own tendon sheaths covered by the upper and lower retinaculum of the extensor muscles. The fascial space of the dorsum communicates with the anterior fibrous bone sheath of the leg.

Under the skin of the plantar region from the calcaneal tuberosity to the heads of the metatarsal bones lies the plantar aponeurosis, which has commissural openings in the distal sections. Through them, the subcutaneous tissue of the sole and toes communicates with the median fascial space. From the aponeurosis, aponeurotic septa are directed deep. Two septa and the interosseous fascia divide the entire subaponeurotic space into three sections.

The medial fascial space of the sole, containing the short muscles of the big toe. It is delimited externally by the medial intermuscular aponeurotic septum (attached to the calcaneus, navicular, first cuneiform and first metatarsal bones), and in the proximal direction it ends blindly, without communicating with the fascial spaces of the leg.

Lateral fascial space of the sole containing the muscles of the fifth toe. On the inner side it is delimited by the lateral intermuscular aponeurotic septum (attached to the fifth metatarsal bone and the tendon sheath of the long peroneus muscle). In the proximal direction, as well as the medial direction, it ends blindly.

The medial fascial space of the sole, containing the short flexor and long flexor tendons of the fingers, as well as vessels and nerves. On the inner and outer sides it is delimited by the medial and lateral intermuscular septa, respectively; on the sole side - by the plantar aponeurosis and in the depth - by the interosseous muscles and the deep fascia covering them. In the proximal direction it communicates with the deep fascial space of the leg through three channels: plantar, calcaneal and malleolar.

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Routes of infection spread

When choosing the correct surgical approach, it is important to clearly understand the possible routes of infection spread from the primary focus to adjacent anatomical areas.

Phlegmon of the foot can spread:

• in the distal direction - to the fingers and fascial spaces of the plantar region;
• in the proximal direction - to the anterior fibrous bone sheath of the leg.

The medial fascial space of the sole (the most common localization of infection) communicates with several adjacent anatomical areas.

In the distal direction: through the commissural openings - with the subcutaneous tissue of the sole; along the canals of the lumbrical muscles - with the interosseous and fascial spaces of the back.

In the proximal direction: through the plantar, calcaneal and ankle canals - with the deep fascial space of the leg.

In the medial direction: along the course of the tendon of the long flexor of the big toe - with the medial fascial space of the sole.

In the lateral direction: along the course of the flexor tendon - with the lateral fascial space of the sole.

How does foot phlegmon and finger abscesses manifest?

Finger abscesses are accompanied by local hyperemia and swelling and are usually easily diagnosed. Distal finger abscesses do not tend to spread proximally.

Phlegmon of the dorsal side of the foot

The infection can penetrate directly through the damaged skin in this area or spread from the sole through the canals of the worm-like muscles or directly through the intermetatarsal spaces (difference from phlegmon of the hand). Phlegmon of the foot is characterized by bright hyperemia of the skin with clear edges, very similar to erysipelas. The skin acquires a characteristic shine, the edema increases and spreads beyond the hyperemia zone. It is possible for the process to spread to the anterior fascial space of the shin.

Subcutaneous (epifascial) phlegmon of the foot

Superficial phlegmon of the foot (abscess) of the sole, as a rule, has traces of skin damage and minor local swelling and pain. Usually there are no difficulties with recognition and differential diagnostics with other phlegmons. Spontaneous pain in epifascial purulent processes occurs only when lymphangitis or thrombophlebitis joins. Hyperemia of the skin in all plantar phlegmons is not expressed due to the thickness of the epidermal layer. As a rule, there is no tendency to spread to other anatomical zones.

Phlegmon of the foot of the medial cellular space

Such isolated phlegmon of the foot is rarely recognized, only in the earliest stages of its development. Later, through openings in the medial intermuscular aponeurotic septum along the tendons that pierce it or when it melts, pus can spread into the median cellular space and very rarely - in the proximal direction.

Phlegmon of the foot of the medial cellular space, unlike other subaponeurotic phlegmons of the sole, is characterized by the occurrence of swelling (in this part the aponeurosis is the thinnest), but hyperemia of the skin is not expressed. Pain on palpation at any point of the sole is a sign of the spread of the process into the median cellular space.

Phlegmon of the foot of the lateral cellular space

Such phlegmon, in its primary nature, as well as medial, can be detected only at fairly early stages of development. Phlegmon of the foot quickly spreads to the median cellular space.

Differentiating foot phlegmon from other types of the same area is extremely difficult due to its scanty symptoms. There is no swelling, hyperemia or fluctuation. Pain on palpation with a button probe in the lateral area of the sole may be the only symptom of the disease.

Phlegmon of the foot of the median cellular space is the most common of all phlegmons of the plantar region. It is characterized by rapid melting of the intermuscular aponeurotic septum. It most often occurs due to the spread of phlegmon of the medial and lateral fascial spaces to the median. Pulsating pain is characteristic, sharply increasing upon palpation of any part of the sole. The skin of the sole, as a rule, is not changed in color, there is no edema and fluctuation. The scanty symptoms of the inflammatory process are explained by the presence of a powerful plantar aponeurosis and the large thickness of the skin in this area. Changes can be detected only by careful comparison of the diseased and healthy feet. The general condition is severe, with a high temperature. Significant edema and hyperemia of the dorsum are characteristic (the inflammation spreads between the bases of the first and second metatarsal bones). Spread through the malleolar canal to the deep fascial space of the shin is typical. In this case, hyperemia, swelling and sharp pain upon palpation appear in the space between the Achilles tendon and the medial malleolus (the ankle canal area), and later swelling of the lower leg develops in combination with sharp pain.

Combined phlegmon of the foot

The most common variant of the course of phlegmon. Phlegmon of the foot of the medial and lateral spaces of the sole is most often combined with phlegmon of the median space (due to communication between the spaces), which tends to spread to the back.

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Tendonitis

Acute purulent tendovaginitis of the back is rare, it occurs with direct damage if the wound is located along the tendons of the extensor muscles. Usually the process is not limited to the tendon sheaths and affects the entire interfascial space; phlegmon of the foot is formed. The infection can spread to the anterior fascial space of the shin.

Tendonitis of the flexor tendons in the plantar region occurs most often. The cause is direct damage to the tendon sheaths, which are located close to the skin of the plantar surface of the toes and are most accessible to infection. At the site of injury, the toe becomes sharply swollen and hyperemic. Acute pulsating pain is characteristic, increasing with palpation with a button probe localized along the course of the corresponding flexor muscles. Tendonitis of the flexor of the big toe is of particular importance, since the purulent process quickly destroys the proximal end of the sheath and penetrates into the medial cellular space, and from there into the median cellular space with the development of combined subaponeurotic phlegmon of the sole.

Chronic tendovaginitis is less aggressive, occurs much more often than acute (with repeated injuries), and treatment in most cases is conservative.

Suppurative arthritis

Purulent inflammatory processes in small joints are rare, and in most cases it is difficult to determine the primary nature of the lesion. The literature contains indications of the possibility of developing purulent arthritis as a complication of infectious diseases (gonorrhea, syphilis and brucellosis). Sometimes purulent arthritis of small joints occurs after bruises.

Initially, there is pain in the foot, which increases with static and dynamic loads. After a significant period of time, edema and hyperemia appear, mainly on the back. The radiograph shows pronounced osteoporosis of the tarsal bones and proximal heads of the metatarsal bones, a sharp widening of the joint spaces. The greatest destructive changes are usually determined in the area of the navicular-cuneiform and cuneiform-metatarsal joints.

Osteomyelitis

Osteomyelitis of the bones may develop as a complication of open fractures or as a result of the spread of a purulent process to the bone from the soft tissues. In hematogenous osteomyelitis, mainly large bones are affected - the calcaneus and talus. The disease is characterized by an acute onset, an increase in temperature to 39-40 ° C and local pain during palpation. On the radiograph, changes occur on the 10-14th day: thickening, osteoporosis. Occasionally, sequesters can be detected on radiographs during this period, but the spongy structure of the most frequently affected bones makes their diagnosis difficult.

Classification of purulent-inflammatory diseases

Clinical classification of purulent-inflammatory processes (built in accordance with anatomical principles).

• Finger abscess.
• Phlegmon of the dorsal side of the foot.
• Phlegmon of the plantar side of the foot:
  • subcutaneous (epifascial) phlegmon of the foot;
  • medial, lateral and midline cellular spaces;
  • combined phlegmon of the foot;
• Tendonitis.
• Purulent arthritis.
• Osteomyelitis of bones.

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How is foot phlegmon treated?

Treatment goals for finger abscesses and phlegmon:

• ensure adequate drainage of purulent exudate;
• prevent the spread of infection (using radical necrectomy);
• create favorable conditions for healing with minimal functional and aesthetic disturbances.

Surgical treatment is carried out against the background of antibacterial therapy (taking into account the antibiotic sensitivity of the infectious agents). Anesthesia and detoxification are essential conditions for successful treatment in the early stages. Foot surgeries are performed under conduction anesthesia. The foot is necessarily ischemized by placing a tonometer cuff on the lower third of the leg and quickly pumping air to 150-200 mm Hg. During the acute period, immobilization of the ankle joint is also necessary.

In case of finger abscesses and phlegmons of the back, outpatient treatment is possible. In case of subaponeurotic processes, arthritis and osteomyelitis, urgent hospitalization is necessary due to the threat of spreading the purulent process in the proximal direction and to deeper anatomical structures.

Incisions for finger abscesses are made over the site of greatest pain, revealed by palpation with a button probe. For wide opening of the purulent focus, arcuate or club-shaped incisions are made, allowing for complete excision of necrotic tissue. Treatment is continued in accordance with the general principles of managing purulent wounds. When localizing abscesses on the main phalanges, one should remember about the possibility of infection spreading to the area of the interpalladian spaces and the median fascial space of the sole along the canals of the worm-shaped muscles, therefore, if necessary, the incisions are expanded in the proximal direction. To open the dorsal phlegmon, longitudinal incisions are made away from the dorsal artery. In this case, the skin and dorsal fascia are dissected, pus and necrotic tissue are removed, and the resulting cavity is drained. After adequate necrectomy, the operation can be completed by applying a drainage and irrigation system and primary sutures,

Common subfascial phlegmon of the dorsal plantar fasciitis is treated with an incision along the entire length, and if the tendon sheaths are involved in the process, the cruciate ligament is cut.

If the anterior fascial space of the leg is involved in the purulent process, the incision is made along the anterior surface of its middle third, 2 cm outward from the crest of the tibia. After dissecting the skin, subcutaneous tissue and dense fascia, the perivascular tissue is penetrated through the muscles (between the anterior tibialis muscle and the long extensor of the fingers). In the case of a widespread process, counter-opening incisions are made through the entire muscle mass of this area for complete drainage. During revision of the purulent cavity, the interosseous septum is necessarily examined: if pus penetrates through openings or defects in it, it is necessary to open and drain the posterior fascial space of the leg.

In case of epifascial phlegmon of the sole, it is sufficient to make a small incision over the site of greatest swelling and pain, radically sanitize the abscess and complete the operation by applying a drainage and washing system (the ends of a perforated polyvinyl chloride tube are brought out through punctures in healthy skin) and primary sutures on the skin.

To open the medial space, a Delorme incision is most often used in the distal half, corresponding to the projection of the first metatarsal bone. Since the infection of this space tends to spread quickly, when pus enters through defects in the medial intermuscular septum, surgical intervention is supplemented by opening the median cellular space.

When opening the lateral space phlegmon, the Delorme incision is made in the distal half according to the projection of the IV metatarsal bone. After evacuation of pus, necrectomy and sanitation of the wound, the lateral intermuscular septum is examined. If pus enters through defects in it, the median cellular space should be additionally opened.

One median incision on the foot in the projection of the third metatarsal bone may not be enough, since the closure of the edges of the incision of the plantar aponeurosis and muscles leads to a violation of the outflow of pus. For adequate opening and drainage, it is advisable to perform two lateral incisions in the projection of the vertical bone-fascial bridges of the sole, then excise the necrotic areas of the bridges, creating conditions for better outflow of pus, and conduct a drainage tube into the deepest part of the median space.

When purulent leaks are detected in the interdigital spaces, the opening of the abscesses is supplemented by a transverse incision in the distal part of the sole, in the area of the distal heads of the metatarsal bones (Fig. 33-6), and when the process moves to the back - counter-opening incisions on the back, most often between the second and third metatarsal bones.

If pus spreads into the deep fascial space of the leg (along the flexor tendons and the posterior tibial vascular-nerve bundle through the malleolar canal), it must be opened. An obvious and frequent sign of proximal spread of infection is the appearance of pus in the subaponeurotic space of the sole when pressing on the lower third of the leg and the inner (medial) retromalleolar region. In this case, it is necessary to open the deep fascial space of the leg with an incision along the inner surface in its lower third, retreating 1 cm from the inner edge of the tibia. After opening the superficial fascia, the tendon m. soleus is shifted back and to the side, the inner fascia is exposed and dissected, and then the deep phlegmon is opened. Unfortunately, such separate opening of the deep fascial space of the leg and the subgaleolar space can lead to necrosis of the tendons of the flexor muscles of the ankle canal. In these cases, a single incision is preferable, opening access to the subgaleolar space, the internal malleolar canal and the deep fascial space of the leg. The above-described incisions are combined by dissecting the anterior wall of the malleolar canal.

Surgical treatment of combined phlegmon includes elements and features of the technique of interventions on each of its components.

In acute purulent extensor tendovaginitis, surgical treatment, if necessary, consists of opening the fascial space of the back. In case of damage to the flexor tendons, the affected tendon sheath is immediately opened, since in these cases tendon necrosis develops quickly and the purulent process spreads to adjacent anatomical areas.

Surgical treatment of purulent arthritis depends on the localization and degree of soft tissue involvement. Most often, phlegmon of the dorsal foot is opened. Having opened the deep fascia of the dorsum of the foot and provided good access to the joints, the affected bone structures are treated with a Volkman spoon and a flow drainage and washing system is installed with the application of primary sutures to the skin. After 8-12 days, the drains are removed, and immobilization of the foot is maintained for another 10-12 weeks.

In the treatment of acute hematogenous osteomyelitis of bones, priority is currently given to antibacterial therapy. If the de-escalation principle of antibiotic therapy is followed, the body temperature normalizes, pain stops, and the sequestration process is stopped by the 2nd or 3rd day. The presence of sequesters and fistulas is an indication for surgical treatment (radical sequestrectomy) in accordance with the general principles of osteomyelitis treatment. In case of osteomyelitis of the calcaneus, an incision is made from the Achilles tendon to the anterior edge of the bone through the entire thickness of the soft tissues. The bone is trepanned and cleaned from the inside, trying not to damage the cortical layer. Freely lying cortical sequesters are removed by scraping out the residual cavity with a sharp spoon, and the soft tissues are sutured over the drainage placed in the resulting bone defect. In case of osteomyelitis of the talus, anterior or posterior arthrotomy is performed with sanitation of the pathologically altered bone structure. In case of total damage to the talus, an astragalectomy is performed.

Secondary forms of osteomyelitis, unlike hematogenous osteomyelitis, are less acute, develop slowly and are not accompanied by major destruction of bone structures.

In the postoperative period, antibiotic therapy is indicated in combination with painkillers. Immobilization with a plantar plaster splint for 4-5 days is mandatory until acute inflammation in the soft tissues subsides.

What is the prognosis for foot phlegmon?

After opening the purulent foci on the toes, phlegmon of the foot has a favorable prognosis. After operations on the bones for osteomyelitis, an orthopedic consultation is indicated to decide on the advisability of wearing special shoes.