DEFINITION

The term osteochondral lesion of the talus (OLT) refers to any pathology of the talar articular cartilage and corresponding subchondral bone. A variety of names have been given to these lesions, including osteochondritis dissecans, osteochondral fracture, transchondral fracture, and osteochondral defect, but currently, OLT is the preferred nomenclature.

Particulated juvenile cartilage allograft transplantation (PJCAT) is a new technique of transplantation of multiple fresh juvenile cartilage allograft tissue pieces, containing live cells within their native extracellular matrix, with fibrin adhesive securing the tissue pieces firmly inside the OLT.

This technique is in many ways similar to the osteochondral autograft transfer with the following differences: transplantation of particulated cartilage pieces instead of osteochondral plugs, the use of juvenile cartilage instead of adult cartilage, and graft fixation with fibrin adhesive instead of bony press-fit. The advantages of this technique are that it is a surgically simple procedure without the need for graft

press-fitting/contouring (as needed for osteochondral autograft or allograft transplantation), it does not require osteotomy in most cases (as often needed for osteochondral autograft transfer or allograft transplantation), it is a single-stage procedure, there is no donor site morbidity, and there is a minimal chance for immunologic reaction (cartilage is considered immune privileged).

The disadvantages of this technique are the fact that it is a relatively new procedure with limited patient data, there is a limited supply of juvenile donor cartilage, it is a relatively expensive treatment option compared to other techniques, and as with any allograft tissue, disease transmission concerns exist.

Currently, the only graft material available for this procedure is DeNovo NT Natural Tissue Graft (Zimmer, Inc., Warsaw, IN). The cartilage pieces of this product are obtained, in compliance with Good Tissue Practice, from donors ranging in age from newborn to age 13 years; however, it is typically obtained from

neomorts younger than the age of 2 years.1 No stillborn or fetal tissue is used. Standard disease screening is performed on each lot (one lot of tissue comes from a single donor).

 

ANATOMY

 

Tol et al15 reported that 56% of OLTs were located medially and 44% were located laterally. Of the medial lesions, trauma was implicated in only 62%, whereas trauma was implicated in 94% of the laterally located lesions.

 

Elias et al6 reported similar results regarding location in a magnetic resonance imaging (MRI) examination of 424 OLTs. The talar dome was divided into nine equal sizes zones. Sixty-two percent of lesions were located medially, whereas 34% were located laterally. In the sagittal plane, 80% of lesions were located centrally. The medial-central zone was the most common location for lesions (53%). The authors also reported that medial lesions were significantly larger and deeper.

PATHOGENESIS

 

Kappis7 initially described this pathology as osteochondritis dissecans, suggesting spontaneous necrosis of bone as the primary etiology.

 

However, contemporary data support trauma as the cause of most OLTs, with repetitive microtrauma, avascular necrosis, and congenital factors as the remaining etiologies.4

NATURAL HISTORY

 

There is debate as to whether a symptomatic OLT will increase in size or progress to ankle arthritis.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

An OLT should be suspected in anyone presenting after acute traumatic injury to the ankle, chronic ankle sprains, or chronic instability. Patients may complain of pain, stiffness, catching, and swelling of the ankle.11 However, none of these complaints are specific to OLTs.

 

Often, in the acute setting, a detailed examination is limited secondary to pain and swelling.

 

In chronic cases, the ankle should be palpated for areas of tenderness. Specifically, the ankle should be plantarflexed, partially uncovering the talar dome, and deep palpation of the anteromedial and anterolateral corners can elicit pain in the presence of an OLT.

 

Ankle range of motion (ROM) should be recorded and compared to the contralateral extremity. Ankle stability, including the anterior drawer and talar tilt tests should be performed and compared to the contralateral extremity.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Every patient should have weight-bearing anteroposterior (AP), lateral, and mortise radiographic views of the ankle joint.

 

 

A debate exists as to the choice of MRI or computed tomography (CT) following negative plain radiographs in a patient with a suspected OLT. We routinely perform an MRI first, as this modality has been shown to be more accurate2 in

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diagnosing OLTs in the setting of negative plain radiograph and an MRI may identify other bony or soft tissue pathology involved in a painful ankle.

 

Stroud and Marks14 proposed an algorithm regarding OLTs diagnosed on plain radiographs. If the OLT is nondisplaced, an MRI is recommended to evaluate the integrity of the articular cartilage and assess the true stability of the lesion. If the lesion appears displaced on plain radiographs, a CT scan is preferred to accurately assess the lesion size and location.

 

In some cases in which an OLT is diagnosed on MRI, a CT scan can be beneficial for determining the treatment modality, as estimation of the size and stage of the lesion can be obscured by bone marrow edema on MRI.9 We routinely obtain both an MRI and a CT scan in large or cystic lesions to aid in treatment decision

making.

 

DIFFERENTIAL DIAGNOSIS

 

Occult fracture of the talus

 

Syndesmosis injury

 

 

 

Synovitis Degenerative arthrosis Peroneal tendonitis

 

 

Soft tissue or bony impingement Ankle instability

 

Subtalar arthritis

 

NONOPERATIVE MANAGEMENT

 

The initial treatment for a newly diagnosed OLT should be based on the patient's age, symptoms, chronicity, and stage of the lesion.

 

 

Incidentally found asymptomatic lesions do not need treatment but should be followed with serial radiographs. For symptomatic, nondisplaced lesions, some authors recommend a trial of conservative management for a period of 3 to 6 months.3,10,13

 

Nonoperative modalities include protected weight bearing, physical therapy, and nonsteroidal anti-inflammatory drugs (NSAIDs). Protected weight bearing can range from cast immobilization and non-weight-bearing status to weight bearing as tolerated in a walking boot.

 

SURGICAL MANAGEMENT

Arthrotomy

 

Indications for PJCAT include a primary OLT that is larger than 15 mm in one dimension and/or that has previous failed a marrow stimulation technique with continued symptoms and an OLT as evidenced on MRI. Shoulder and cystic lesions are not excluded.

 

Contraindications to surgical management of OLTs include infection, medical comorbidities that preclude a surgical procedure, diffuse ankle arthritis, or uncorrected ankle malalignment.

 

 

Specific recommended contraindications to PJCAT include large cystic or necrotic bony defects. Small cystic lesions with bony defects can be managed with concomitant bone grafting with PJCAT. In these instances, the authors have performed local bone grafting from the calcaneus, tibia, or iliac crest with application of the PJCAT graft in the same surgical setting.

 

 

PJCAT delivers 1 mm3 of fresh juvenile cartilage, containing live cells in their native extracellular matrix, that are secured into the osteochondral defect with the use of a fibrin adhesive. Because of the particulated nature, perpendicular access to the OLT is not needed. Therefore, an osteotomy is often not necessary. Here, we will discuss the use of an anterior arthrotomy.

 

Arthroscopic

 

Performing all-arthroscopic PJCAT can be challenging.

 

The diagnostic arthroscopy serves to ensure that complete access to the OLT can be obtained.

 

We have a low threshold to move to an extended portal approach or arthrotomy if OLT access or instrument working room is limited.

Preoperative Planning

 

 

Preoperative planning is the same for open or arthroscopic surgery. Confirmation of the location and size of the OLT is absolutely necessary.

 

Determination of the appropriate amount of graft to be preordered is necessary. Per the manufacturer, one pack of DeNovo NT Natural Tissue graft (Zimmer) is recommended to treat each 2.5 cm2 of lesion surface area, with a recommended fill ratio of at least 50% of the lesion size (eg, each pack of tissue graft will cover

1.25 cm2 of surface area). In practice, attempts are made to completely fill the lesion's surface area to the depth of the surrounding healthy cartilage while allowing fibrin adhesive to interpose between cartilage pieces for good tissue fixation.

 

Fibrin glue (5 to 10 mL) will be needed. Typically, this is stored frozen. It has been our experience that rapid thawing alters the workability of the fibrin glue. Therefore, the fibrin glue should be opened at the start of the case and placed in a warm saline bath according to the manufacturer's recommendations.

 

Inspect the PJCAT product for the expiration date prior to starting the procedure.

 

Positioning

Arthrotomy

 

The patient is positioned supine. An ipsilateral proximal thigh bump is used to point the toes to the ceiling.

 

Often, even for the open approach, we perform a diagnostic arthroscopy to confirm the size and location of the lesion. The location of the lesion is assessed while the ankle joint is ranged. This allows a better assessment as to whether the lesion can be approached through an arthrotomy with or without plafondplasty versus a medial or lateral malleolar osteotomy. The technique for standard arthroscopy is beyond the scope of this chapter but is detailed elsewhere.

 

Arthroscopy

 

The patient is placed supine on the operating room table with the foot at the end of the bed. The operative leg is placed in a leg holder to keep the hip and knee flexed.

 

We recommend using noninvasive destraction to allow working room for graft application.

 

 

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Approach

Arthrotomy

 

The approach is based on the location of the lesion. An anteromedial arthrotomy is used for medial dome lesions, an anterolateral arthrotomy us used for lateral dome lesions, and a direct anterior arthrotomy is used for central lesions.

 

An anterior plafondplasty may be used for more posterior lesions when using an anterior approach. Peters et al,12 using a limited anterior plafondplasty, were able to visualize all but the central 10% of the posterior talar dome.

 

Arthroscopy

 

Standard anteromedial and anterolateral portals are used and routine arthroscopic examination of the ankle joint is performed.

TECHNIQUES

• Anteromedial, Anterolateral, or Direct Anterior Arthrotomy

Exposure

 

 

Make a longitudinal incision centered over the ankle joint and just medial to the tibialis anterior tendon for an anteromedial arthrotomy and just lateral to the peroneus tertius tendon for an anterolateral arthrotomy. Carefully dissect, identify, and protect any branches of the superficial peroneal nerve that may cross the incision for an anterolateral arthrotomy.

 

Incise the extensor retinaculum in line with the skin incision.

 

Retract the tibialis anterior tendon laterally or the peroneus tertius tendon medially to expose the joint capsule.

 

Incise the joint capsule in line with the skin incision and place a deep retractor.

Plafondplasty (Optional)

 

Plantarflex the foot to assess the visibility of the OLT. If the entire lesion is not visible, an anterior tibial plafondplasty is performed, but it is important to remember that perpendicular access is not needed for PJCAT (TECH FIG 1A).

 

Using a curved one quarter-inch osteotome, the superior and medial or lateral aspect of the anterior tibial plafond is removed (TECH FIG 1B).

 

Place a Joker or Freer retractor into the joint space to protect against further damage to the talar cartilage (TECH FIG 1C).

 

 

 

TECH FIG 1 • A. Plantarflexed foot demonstrating anteromedial osteochondral lesion. The back of the lesion cannot be visualized. B. A curved osteotome is used to create the plafondplasty. C. A smooth elevator is placed in the joint space to protect the surrounding talar cartilage from injury during the plafondplasty.

 

 

Careful attention should be made not to remove more than 1 cm of the nonarticular tibia in any dimension. Only the minimal amount of tibia necessary to débride and fill the lesion should be removed. Smaller plafondplasties are generally not repaired.

 

If the plafondplasty approaches 1 cm in any dimension or loss of structural integrity is a concern, consideration should be given to small fragmentary screw or bioabsorbable pin fixation.

Osteochondral Lesion of the Talus Débridement

 

Visualization may be further enhanced with use of a Hintermann style distractor or a lamina spreader secured to the tibia and talus with pins.

 

Débride the lesion until stable margins are achieved on all sides using a combination of a no. 15 blade and small curette (TECH FIG 2A).

 

Careful attention should be paid to the shoulder of the talus. If it is felt that the shoulder is not involved in the OLT, every attempt should be made to leave the medial or lateral cartilage border at the shoulder (TECH FIG 2B). This will help to contain the cartilage/fibrin mixture in the lesion and not have it spill into the medial or lateral gutter.

 

 

There is debate as to the preparation of the base of the lesion with regard to the addition of marrow stimulation (microfracture) by violating the subchondral plate. In all reality, with adequate débridement, the subchondral plate is often penetrated in at least one location. We routinely perform microfracture at the base of the lesion.

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TECH FIG 2 • A. A curette is used to débride the lesion to stable margins. B. The lesion has been débrided. Notice bleeding bone base.

 

 

Irrigate the joint.

 

If, after débridement, the base of the OLT requires bone grafting, the bone from the plafondplasty can be used. Alternatively, trephine obtained bone from the calcaneus, tibia, or iliac crest can be used.

Graft Preparation and Insertion

 

Leave a sponge in the joint while preparing the graft to ensure a dry lesion base.

 

Take the DeNovo NT Graft packet and turn it so that the pointed end of the plastic well faces the ground to allow the cartilage pieces to settle to the bottom.

 

Insert a 21-gauge, 1.5-inch needle connected to a 10-mL syringe through the top of the plastic and

carefully aspirate the medium without removing any of the cartilage pieces (the cartilage pieces are larger than the needle diameter) (TECH FIG 3A,B).

 

Peel back the foil (do not discard).

 

Cut the foil lid a strip and bend in the center to create a trough. Alternatively, the plastic packaging can be cut to a point (TECH FIG 3C,D).

 

Use a Freer elevator to scoop the cartilage pieces into the trough and deliver to the joint space (TECH FIG 3E).

 

Next, use an elevator or equivalent instrument to push the cartilage pieces into the bed of the lesion until particulated cartilage completely covers the base.

 

 

 

TECH FIG 3 • A. A needle is introduced through the plastic to remove the support media. B. All of the media has been removed. The cartilage pieces are larger than the needle diameter and will not be aspirated. C. The plastic reservoir is being cut. D. The point of the plastic reservoir will be used to deliver the chips to the lesion. (continued)

 

 

Apply a small amount of fibrin glue over the cartilage pieces (TECH FIG 3F).

 

Additional particulated cartilage pieces are added in layered fashion until the depth of the lesion is completed filled without the construct being proud. An additional amount of fibrin glue is applied to the lesion to complete the particulated cartilage/fibrin glue construct.

 

It is important to have extra fibrin delivery tips available, as they can become clogged in between applications of fibrin glue to the defect.

 

 

Use a Freer elevator to remove any excess pieces and contour the surface of the lesion (TECH FIG 3G). Before the fibrin glue has completely set up, dorsiflex the ankle until the lesion is completely covered.

Apply axial compression to use the contour of the tibial articular surface to mold the superior surface of the talar lesion. Maintain compression for 5 minutes.

 

Plantarflex the ankle and assess the lesion for areas that require additional graft material (TECH FIG 3H).

Closure and Application of the Dressing

 

Have an assistant keep the foot dorsiflexed during the closure and application of the splint. This will keep the lesions covered under the tibia.

 

 

 

Close the capsule, retinaculum, and skin in layered fashion. Apply splint.

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TECH FIG 3 • (continued) E. The chips are evenly delivered to the lesion using an elevator. F. Fibrin glue is applied to the lesion and the cartilage chips are completely covered. G. An elevator is used to contour the lesion and remove and loose chips. H. The final covered lesion after being contoured to the tibial plafond.

• Arthroscopic Technique

Osteochondral Lesion of the Talus Débridement

 

 

Débride the synovium to prevent obstruction of the camera or passage of instruments and graft. Define the lesion with an arthroscopic probe. Measure the lesion to ensure there is adequate graft available (TECH FIG 4A).

 

Use various arthroscopic cup and ring curettes to débride the cartilage back to a circumferential stable margin with vertical walls to contain the graft (TECH FIG 4B). Every attempt is made to leave a peripheral vertical wall for shoulder lesions (TECH FIG 4C).

 

 

 

TECH FIG 4 • A. A probe is used to assess the size of the lesion. B. A curette is used to débride the lesion. C. The lesion is débrided to stable cartilage margins.

 

 

Temporarily shut off the inflow, as graft delivery occurs in this setting. This allows the surgeon to assess for soft tissue invagination at the working portal site that might interfere with graft insertion. Inflow is restored for further soft tissue débridement.

 

If cancellous bone graft is needed at the base of the lesion, it can be applied in the same manner as described for cartilage graft insertion (see the following text). Bone graft can be obtained from the calcaneus using a trephine.

Joint Preparation

 

 

Again, shut off the inflow and evacuate the joint of fluid with the use of a small suction catheter and the arthroscopic shaver (TECH FIG 5A).

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TECH FIG 5 • A. The débrided lesion after the inflow is shut off and the arthroscopic fluid is evacuated.

B. Epinephrine, cotton-tipped applicators, and Weck-Cel sponges used to dry the joint space. C. An epinephrine-soaked cotton-tipped applicator inserted into the joint to provide hemostasis. D. A dry applicator was inserted into the joint to absorb the remaining blood and fluid.

 

 

The lesion bed can be further dried with an epinephrine-soaked Weck-Cel sponge or cotton-tipped applicator to achieve hemostasis followed by a dry cotton-tipped applicator to soak up the excess fluid (TECH FIG 5B-D). Profuse bleeding at the base of the lesion can be addressed using a small amount of fibrin glue.

Graft Preparation and Insertion

 

Take the DeNovo NT Graft packet and turn it so that the pointed end of the plastic well faces the ground to allow the cartilage pieces to settle to the bottom.

 

Insert a 21-gauge, 1.5-inch needle connected to a 10-mL syringe through the top of the plastic and carefully aspirate the medium without removing any of the cartilage pieces (the cartilage pieces are larger than the needle diameter).

 

Peel back the foil (do not discard).

 

Load one-half to one-third of the graft material in a retrograde fashion into the tip of a 2.7-mm arthroscopic cannula using a Freer elevator (TECH FIG 6A).

 

 

Do not load all of the pieces at once. We routinely make two or three passes per package of DeNovo NT. Recess the graft pieces into the cannula, using the corresponding trocar, so they are not exposed, as they can become entrapped in soft tissue when introduced into the joint (TECH FIG 6B,C).

 

 

 

TECH FIG 6 • A. A Freer is used to retrograde load the cartilage pieces into a 2.7-mm cannula. B. The trocar is used to recess the cartilage pieces. C. The cannula is inserted into the joint. Notice the cartilage pieces are recessed. (continued)

 

 

Place the cannula, with the bevel down, at the near edge of the lesion and slowly push the pieces into the lesion using the trocar (TECH FIG 6D,E).

 

Remove the cannula and insert a Freer or probe to distribute the graft uniformly throughout the base of the lesion (TECH FIG 6F,G).

 

Insert the fibrin glue tip through the arthroscopic portal and apply a small amount of fibrin. Occasionally, the tip provided with the fibrin glue is too short and an angiocatheter or a needle can be used (TECH FIG 6H).

 

Insert a Freer elevator or probe to mold the pieces uniformly in the lesion while the fibrin becomes more viscous (TECH FIG 6I).

 

Repeat these steps until the lesion is completely filled.

 

Allow the fibrin glue to set for 5 to 10 minutes until opaque (TECH FIG 6J).

Closure and Application of the Dressing

 

Have an assistant keep the foot dorsiflexed during the closure and application of the splint. This will keep the lesions covered under the tibia.

 

 

The arthroscopic portals are closed with nylon, and a wellpadded splint is placed with the ankle in a position to fully contain the lesion under the tibia plafond.

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TECH FIG 6 • (continued) D. The cannula is advanced to the lesion with the bevel side down and the pieces are deployed to the lesion using the trocar. E. The trocar is inserted into the cannula to deploy the cartilage pieces to the lesion. F. The cartilage pieces have been placed into the lesion. G. A Freer elevator is used to arrange the pieces in the lesion. H. Fibrin glue is placed over the cartilage pieces. I. A Freer elevator is used to mold the pieces and fibrin glue. J. The final lesion after the fibrin glue has set.

 

PEARLS AND PITFALLS

Particulated juvenile cartilage allograft transplantation (PJCAT) is indicated for focal osteochondral lesions and not for diffuse degenerative arthritis.

If the osteochondral lesion is associated with a subchondral cyst, the cyst should be curetted and bone grafted prior to performing the PJCAT.

Whether through an arthrotomy or arthroscopically, the PJCAT should be performed with the ankle joint as dry as possible before performing PJCAT.

In PJCAT the transplanted cartilage particles should fill the defect to the level of the native cartilage rim; stacking the particles so that they are proud may lead to shear of the transplanted cells.

An excessive amount of fibrin glue is unnecessary. Glue the extends beyond the defect may adhere or impinge with ankle motion, creating tension on the glue covering in the defect, thereby potentially dislodging the cartilage particles.

 

POSTOPERATIVE CARE

 

The patient is kept in the splint, non-weight bearing for 10 to 14 days. Sutures are removed at that point and the patient is placed in a removable boot. The patient remains non-weight bearing. Gentle ROM exercises are started. ROM exercises are avoided in anterior lesions.

 

At the 6-week postoperative time period, the patient may start progression to full weight bearing over the next 6 weeks.

 

The boot can be removed at 12 weeks and a lace-up ankle brace can be worn.

 

 

Full ROM is allowed provided there is no contraindication based on concomitant performed procedures.

 

Physical therapy, strengthening exercises, stationary bicycle, and water activities may be initiated.

 

Impact activities are not started until 6 months.

 

 

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OUTCOMES

Coetzee et al5 presented a retrospective case series of 23 patients (24 ankles) treated with PJCAT at a mean follow-up of 16.2 months.

The mean lesion surface size was 125 mm2 (range, 50 to 300 mm2) with a mean depth of 7 mm (range, 3 to 20 mm). All lesions had at least one dimension greater than or equal to 10 mm.

The lesions were accessed via an open approach in 12 cases, an arthroscopic approach in 3 cases, and through an extended portal open approach in 9 cases. Bone grafting was performed on lesions deeper than 5 mm.

Postoperative outcome scores were similar to published reports on patients who were treated with bone marrow stimulation, autologous chondrocyte implantation, and matrix-induced autologous chondrocyte implantation.

Kruse et al8 presented one case of arthroscopically performed PJCAT to an OLT in a 30-year-old female with a full-thickness posteromedial lesion that measured 7 × 5 mm. At 2 years following surgery, the patient was found to be pain-free with no activity limitations.

 

COMPLICATIONS

An intraoperative complication specific to this technique is premature dislodging the graft material from the lesion. This is especially important for the arthroscopic technique and the authors caution about using the arthroscopic technique in inexperienced hands. Currently, there are no known differences in outcomes between the open and arthroscopic techniques.

Postoperative complications include inadequate take/fill of the OLT and graft material hypertrophy. Symptomatic inadequate take/fill should be assessed at the time of a secondlook procedure. The lesion should be assessed for revision PJCAT versus another treatment procedure based on the progression of the OLT. Graft hypertrophy can be managed with arthroscopic débridement.

 

REFERENCES

1. Adams SB Jr, Yao JQ, Schon LC. Particulated juvenile articular cartilage allograft transplantation for osteochondral lesions of the talus. Tech Foot Ankle Surg 2011;10(2):92-98.

    

    

2. Anderson IF, Crichton KJ, Grattan-Smith T, et al. Osteochondral fractures of the dome of the talus. J Bone Joint Surg Am 1989;71(8): 1143-1152.

    

    

3. Bauer RS, Ochsner PE. Nosology of osteochondrosis dissecans of the trochlea of the talus [in German]. Z Orthop Ihre Grenzgeb 1987;125(2):194-200.

    

    

4. Campbell CJ, Ranawat CS. Osteochondritis dissecans: the question of etiology. J Trauma 1966;6(2):201-221.

    

    

5. Coetzee JC, Giza E, Schon LC, et al. Treatment of osteochondral lesions of the talus with particulated juvenile cartilage. Foot Ankle Int 2013;34(9):1205-1211.

    

    

6. Elias I, Zoga AC, Morrison WB, et al. Osteochondral lesions of the talus: localization and morphologic data from 424 patients using a novel anatomical grid scheme. Foot Ankle Int 2007;28(2): 154-161.

    

    

7. Kappis M. Weitere beitrage zur traumatisch-mechanischen entstehung der “spontanen” knorpelablosungen (sogen osteohondrisit dessecans). Dtsche Z Chir 1922;171:13-20.

    

    

8. Kruse DL, Ng A, Paden M, et al. Arthroscopic De Novo NT(®) juvenile allograft cartilage implantation in the talus: a case presentation. J Foot Ankle Surg 2012;51(2):218-221.

    

    

9. Lee KB, Bai LB, Park JG, et al. A comparison of arthroscopic and MRI findings in staging of osteochondral lesions of the talus. Knee Surg Sports Traumatol Arthrosc 2008;16(11):1047-1051.

    

    

10. McCullough CJ, Venugopal V. Osteochondritis dissecans of the talus: the natural history. Clin Orthop Relat Res 1979;(144): 264-268.

     

     

11. McGahan PJ, Pinney SJ. Current concept review: osteochondral lesions of the talus. Foot Ankle Int 2010;31(1):90-101.

     

     

12. Peters PG, Parks BG, Schon LC. Anterior distal tibia plafondplasty for exposure of the talar dome. Foot Ankle Int 2012;33(3): 231-235.

     

     

13. Pettine KA, Morrey BF. Osteochondral fractures of the talus. A longterm follow-up. J Bone Joint Surg Br 1987;69(1):89-92.

     

     

14. Stroud CC, Marks RM. Imaging of osteochondral lesions of the talus. Foot Ankle Clin 2000;5(1):119-133.

     

     

15. Tol JL, Struijs PA, Bossuyt PM, et al. Treatment strategies in osteochondral defects of the talar dome: a systematic review. Foot Ankle Int 2000;21(2):119-126.