The numerous publications on osteochondral lesions of the talar dome (LODT) have created confusion about the etiology of such damage.
It is essential to distinguish from the outset:
- The fracture lesions which are always found with certainty notion traumatic (new or old)
- Chronic lesions with onset of osteonecrosis subchondral more or less extensive, described in the literature under different terminologies (osteochondrosis, osteochondritis, osteonecrosis).
This distinction seems to us essential because etiology, radiographic appearance, treatment and prognosis of such lesions are sometimes totally different.

etiology CLASSIFICATION

In 1922 Kappis about a case of osteochondral talar lesion takes the term osteochondritis dissecans described by Koenig at the medial femoral condyle.

Classification and BERNDT HARTY (1959)

From a biomechanical experiment (occurrence of fragmented fracture of the talus in the wake of forced movements of the ankle amputated limbs) and BERNDT HARTY conclude a traumatic of all osteochondral lesions of the talar dome in their first description concern in that external locations of the talar plays:

- Stage I: Simple packing trabecular subchondral
- Stage II: incomplete osteochondral lesion with cartilage cracked open
- Stage III: Complete lesion with osteochondral fragment completely detached but up in its "niche"
- Stage IV: Complete osteochondral lesion with migration or reversal of the fragment.


Classification BERNDT HARTY


This "historical" classification remains unattractive in practice; many radiological images do not find their place. The existence of family forms, diffuse or bilateral atraumatic must also mention other diagnostic hypotheses.

FOG Classification (GOLD / ROSSET 1995)

In France, in 1995, during a multicenter study of West Orthopaedic Society (series of 169 cases), and ROSSET DORE offer a new radiological classification, closer to reality, regardless of etiology, based on the appearance of the lesion (receiver, geodes, frame fragment) and its relationship with the body of the talus (location in relation to the joint surface, condensation around the fragment). They thus distinguish three types of osteochondral lesions of the talus:

- FORM F (such as fracture). This is a fragment without changing the underlying bone structure, without condensation or geode. This form can be recent or old (with in this case, sometimes discreetly lytic appearance). These forms F serve predominantly on the anterolateral side of the slope with a history of trauma constantly found and correspond to stage II and BERNDT HARTY. In their series, this represents almost 20% of cases.

- FORM O (as osteonecrosis). The lesion presents as a receiver with a bone structure in condensed underlying associated micro geodes. This type of lesion is mostly at the posterior-medial region of the talar dome, with no notion traumatic found 3 times 4. In their series, this represents 75% of cases.



necrotic form

- FORM G (as geode). The lesion is characterized by the absence of free osteochondral fragment or receivership; there is actually a radiolucent picture more or less suggestive of a cystic lesion whose etiology can be varied (such as rheumatic synovitis villonodulolaire, synovial cyst intra osseous ischemia by repetitive strain, localized hypertension favored by a varus deviation the back foot). This is a rare entity (7% of cases) bring cystic lesions described by KOUVALCHOUK
.
geodic form


other Classifications

The above classifications do not always reflect the cartilaginous state which nevertheless determines the treatment and prognosis.

Ferkel (1991) proposed a classification based on the results of CT arthrography allows a detailed analysis of the cartilaginous and subchondral extension:

- Stage I: intact articular surface. Subchondral cysts
- Stage II: Open cartilage, subchondral geode
- Stage II b: open cartilage fragment unmoved
- Stage III: Open cartilage, non-displaced fragment, geode subchondral
- Stage IV: displaced fragment.

CHRISTEL (1998), during the review of records of the SFA (312 usable folders) provides in chronic lesions a classification based on arthroscopic findings, which only confirms the lesions analyzed and used to initiate arthrography the treatment of the relevant injury.

- Cartilage closed bounded by a groove, cartilage more or less edematous and malacique.
- Open cartilage fragment in place
- Free Escrow
- Necrosis and geodes talar.
-

DIAGNOSTIC APPROACH

Post traumatic painful aftermath of the ankle are common, proven by clinical symptoms more or less rich and varied during sports or exercise in daily life.
It is the clinical examination that will guide the investigations, in order to give the full lesion diagnosis but especially responsible for the symptomatology injury.
additional tests can be multiplied: Standard radios still needed to analyze musculoskeletal reports or static ankle and foot, ultrasound analysis capsuloligamentous plans and tendons, arthrography for the analysis of articular surfaces , single scanner to locate bony avulsions, foreign bodies or osteochondral lesions.
In fact, now, after the completion of standard clichés and possibly stress, arthrography provides a comprehensive overview in one examination, associated with achieving at the same time an infiltration test cortisone derivative (pending the development and validation of MR arthrography) because it allows a better analysis of chondral lesions, osteochondral, the precise location of foreign body, often a visualization of tendons by leakage of contrast into the capsuloligamentous breaches, with the positive treatment effect or not infiltration test on a secondary reaction synovitis sometimes solely responsible for the clinical symptoms.

FUNCTIONAL SIGNS

The average time to diagnosis of osteochondral lesion between the initial trauma and the discovery of the lesion varies from 0 to several months or years.

The examination is of fundamental importance because if the functional gene is significant in 80% of cases causing stopping of sports activity, one can discover the lesion osteochondral on the occasion of "systematic" standard clichés made the waning of recent trauma. It will therefore carefully analyze the imaging features of the lesion because the discovery LODT discovered may not be related to the recent trauma (forensic interest) and we must try to recover the notion of initial trauma can be involved in the occurrence of diagnosed LODT.

Almost constant pain, usually debilitating, is often anterior and posterior, external and internal, but all combinations are possible, with even diffuse pain poorly systematized.

In nearly half of cases, it is accompanied by swelling in the effort; in 10% of cases, the effusion may be the only telltale sign.

ankle blockages can be found, sometimes simple notion of crunches that must try to clarify the onset mechanism.
Sometimes the patient describes instability accidents qualified sprained repeatedly.

EXAMINATION

The full comparative clinical examination does not provide any specific items within the LODT. It fits more in the analysis of relatively common diseases associated with the "foot from the sport" and attached data interrogation, trying to make sense of things in the analysis of the functional gene.

The static and dynamic morphological type of the foot and the back foot is analyzed in charge: gait analysis, hollow foot varus relatively more common in athletes than valgus flat foot.
As part of LODT the anterolateral lesions (often shaped fracture) occur more often on varus morphotypes while the posterior medial lesions (often form osteo-necrosis) are seen more frequently on valgus morphotypes.

Active and passive mobility is measured (relative stiffness in 20% of cases of LODT) both at the tibiotalar than at the subtalar and all of the midfoot and the forefoot.

The clinical assessment of the stability of the ankle is of course appreciated by the classic maneuvers varus and drawer and completed, in case of doubt by comparative radiographic analysis. More than the technique varus and previous drawers made by the radiologist, the balance telos see better self-varus maneuvers performed by the patient in full support on the outer edge of the foot are much more reliable, a significant differential between side healthy and injured side inciting reflect that laxity in treatment, especially as many LODT can manifest clinically by pseudo accidents instability without significant laxity.

The various tendons perished joint ankle and foot will be examined on well by conventional stretching tests and upset contraction (pain, swelling, crepitus, projection etc ...)

RADIOGRAPHS STANDARDS

We must insist on the perfect technical realization of clichés ankle particular face within urgency.
These shots through the line spacing in internal rotation of about 10 °, allowing for a complete articular place including the side edges of the tibiotalar. Only the quality of such images can detect the waning of the traumatic episode the existence of osteochondral fracture particularly in the anterolateral area of ??the tibiotalar. It may be normal or show signs associated lesion, especially in athletes.


CLICHE RADIO "FACE" TRUE FACE OF CLICHE tibiotalar

With no obvious bone injury before an acute ankle injury of sports, it is necessary to apply the RICE protocol with low icing containment and support depending relieved of pain.
A new clinical assessment is then carried out 3/5 days and in the absence of significant improvement, CT arthrography is justified to search for a bone or osteo-cartilaginous lesion on the unknown initial radiographs.

MRI

Pending validation of the data provided by the arthroIRM, simple MRI does not provide much guidance in the chronic stage in the exploration of a LODT.
By cons, in acute, before an "ankle potato" hardly examinable, edematous, more or less haem without radiologically detectable bone lesion on the standard clichés, it can detect bone impaction, the capsular ligament or tendon injuries that helps the therapeutic conduct.



arthrography

At the stage of post-traumatic sequelae of the ankle, it is the reference examination.
He made the diagnosis of osteochondral lesion lé then allowing classification to guide treatment.
Besides the clinical impact, the evidence adduced by arthrography that will guide the choice of therapeutic management are:
- The openness or otherwise of the chondral lesion,
- headquarters,
- The extent of surface and depth,
- The existence of subchondral bone necrosis, more or less marked,
- The existence or not of bone geodes of greater or lesser size.



CARE THERAPEUTIC

FUNCTIONAL MONITORING

The discovery of a LODT the waning of a "systematic review" may lead to discuss drug therapy, particularly since the lesion is limited without bone underlying reaction (necrosis, geode) significant. Synovitis can be controlled by infiltration and, in the absence of recurrence and increase the clinical symptoms, it is certainly excessive to undertake surgical treatment.

ARTHROSCOPIC TREATMENT

The character "minimally invasive" arthroscopy in fact the basic element of the surgical management of LODT.

GENERAL CHARACTER

The waning of an outpatient or inpatient classic 2 4/5 days depending on the actions performed, it is performed under general or locoregional anesthérie.

Given the important nature of the coaptation tibiotalar joint, complete exploration is only possible at the price of a distraction, even when using a small caliber arthroscope (2.7 mm against 4.5 5 mm to arthroscopes "standard) with instrumental gateways and / or not only visual but also deleted later.
This distraction can be achieved by various more or less invasive means:
- Strap device cravatant ankle on a bent knee Installation stuck in a vise to keep tibiotalar mobility with ups ranging from 3 to 10 kg depending on the case.
- More invasive devices require the installation of pins in the tibia and the calcaneus and the talus (temporary external fixation or traction on trans calcaneal fracture table).


ARTHROSCOPY ANKLE: INSTALLATION / DOOR ENTRY


Complications can occur with the waning of these arthroscopic techniques: especially neurological regarding periarticular branches (superficial peroneal essentially), cartilaginous default distraction and therapeutic failure, training arthroscopic ankle being a state of fact lower than that of knee or shoulder.

THE TASKS PERFORMED

It allows direct visualization of all intra-articular structures tibial-talar: articular surfaces, synovial capsule and ligament structures.

Four situations can meet: closed cartilage, opened with cartilage fragment in place, free receiver, necrosis and geode.

If closed cartilage, exploration found a cartilaginous cap with a continuous delineation depression furrow. When the lesion is still small, it can be curetted with milling and denudation of the bone under ground subchondral.


Curettage Micro fractures Arthroscopic view

If open cartilage, cartilage partially or completely open lid is excised with curettage and bone perforations kind Pridie (micro fractures) are performed.

If escrow free bone, it is removed with curettage and freshening micro fracture on the injury bed on the same terms as in the previous case.

In case of bone and / or necrosis geodes, the same method can be used in case of small lesions.
By cons in case of large (greater than 10/15 mm²), excision of necrosis and filling the geode is inconceivable that open surgical technique.

THE SUITES "POST-ARTHROSCOPY"

Landfilling is required in view of the post-operative pain, but its duration is variable depending on the progress gestures. In general, if curettage denudation of LODT, lack Fitness support during the first three postoperative weeks is relayed by a support club under cover canes three weeks, usual time to find a "normal ankle in terms of everyday life. " The resumption of sports is hardly envisaged before the 3rd / 4th postoperative months, depending on the series of 50 to 70% good functional results, especially ground that the injury remains moderate in size with little change sub ground bone.

The healing is done the same way as the knee (appearance of fibro-cartilaginous tissue interposition, with rarely a bone re-habitation).

Rehabilitation following the progress of the ankle over the postoperative weeks: drainage physiotherapy facilitating the mobilization of the ankle during the first three weeks and then re-progressive support, relearning not running to walking, joint break (training bike and elliptical bike) before muscle strengthening and proprioception previous dynamic return on the sports field.

SURGICAL TREATMENT

In case of arthroscopic treatment or failure to form a necrotic and / or large size geodic, the logical treatment can only be conceived by a surgical technique in the open.

THE TECHNIQUES

Only the former seat of surgical lesions are easy to access.
Once the lesion is located at the apex of the talar dome, it is necessary to use a malleolar osteotomy (medial or lateral) according to rigorous technique so as to have a complete exposure of the lesion to be treated.

Osteotomy internal malleolus

The re-location of a osteochondral fragment fracture in pure form after denudation of the bone under ground is still possible (analogy with "osteochondritis dissecans of the knee).

The simple sponge filling with sampling at the metaphyseal tibial epiphyseal area predominantly geodic form can be offered, as reported KOUVALCHOUK in 1985. This spongy filling is however possible if the lesion after curettage retentive rest.



Ascan geodic Form: pre-op and at 6 months follow-up post transplant spongy curettage


The osteochondral grafts mosaic plasty, as reported HANGODY in 2001 are now running part of the surgical armamentarium of necrotic LODT in their shape and / or geodic.
Taking bone and cartilage grafts is performed at the overlying knee, likely to cause local discomfort during the 4 to 6 months of collection.


Mosaic Plasty Ankle: graft fee, per-op appearance, control Ascan M6


SURGICAL SUITES

They remain relatively codified, in response to the consolidation of a malleolar osteotomy and integration of the bone graft: discharge without support for postoperative 6/8 weeks under cover of a removable immobilization so as to ensure early mobilization of tibiotalar joint (bi-valved or equivalent resin orthosis).

The recovery of a "normal in terms of daily life" ankle requires a period of three to four months, the resumption of sporting activities hardly conceivable before the 6th postoperative month with the same broad functional rehabilitation lines, but shifted in time as those used in the aftermath of arthroscopic techniques.

The results show 60 to 80% good results, all the more remarkable that these surgical techniques, even if they appear "heavy in their more" are for the most serious forms of LODT whose functional symptomatology and natural evolution are the worst.

CONCLUSIONS

Arthroscopic techniques have greatly simplified the postoperative surgical treatment of LODT.
We must know the limits and know both do not offer aggressive treatment of an image incidentally discovered the waning of radiographic examination and, in contrast, do not hesitate to propose an open surgical reconstruction Registry of the most pejorative damage (necrosis and geode).



BIBLIOGRAPHY


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Arthroscopic treatment of talar dome lesions
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Osteochondritis dissecans of treatment of the embankment. Use of technical mosaic plasty: a preliminary report
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HANGODY L, G. KISH, Szerb I., L. GASPAR, Diószegi Z., Z. KENDIK
Mosaicoplastia for the treatment of osteochondritis dissecans of the talus: two to seven year results in 36 patients
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HUNT SA SHERMAN O.
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KOUVALCHOUK JF, J. Rodineau
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NAVID DO, MS MVERSON
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