eMedicine Specialties > Orthopedic Surgery > Foot & Ankle

Osteochondral Lesions of the Talus: Treatment

Author: Gregory C Berlet, MD, FRCS(C), Clinical Assistant Professor of Orthopedics, Chief of Foot and Ankle Surgery, Department of Orthopedic Surgery, Ohio State University College of Medicine and Public Health
Coauthor(s): Christopher F Hyer, DPM, FACFAS, Foot and Ankle Surgeon, Director, Advanced Foot and Ankle Surgery Fellowship, Orthopedic Foot and Ankle Center; Robert D Santrock, MD, Consulting Surgeon, Orthopedic Associates of Meadville, PC
Contributor Information and Disclosures

Updated: Feb 26, 2009

Treatment

Medical Therapy

Conservative management of osteochondral lesions of the talus (OLTs) should be attempted first. Symptomatic patients with negative findings on plain radiographs should undergo an initial period of immobilization, followed by physical therapy. Studies have shown that a trial of conservative therapy does not adversely affect surgery performed after conservative therapy has failed.^4,13 Patients whose plain images indicate OLTs and those who remain symptomatic after 6 weeks should undergo additional evaluation with MRI.

Surgical Therapy

Surgical treatment depends on a variety of factors, including patient characteristics (eg, activity level, age, degenerative changes) and lesions (eg, location, size, chronicity). However, surgical treatment adheres to 1 of the following 3 principles:

• Loose-body removal with or without stimulation of fibrocartilage growth (microfracture, curettage, abrasion, or transarticular drilling)
• Securing OLTs to the talar dome through retrograde drilling, bone grafting, or internal fixation
• Stimulating the development of hyaline cartilage through osteochondral autografts (osteochondral autograft transfer system [OATS], mosaicplasty), allografts, or cell culture (Carticel, Genzyme Biosurgery, Cambridge, Mass)

Preoperative Details

Radiographic imaging is essential to assess alignment and grade the osteochondral lesion of the talus (OLT). A marked distortion of normal mechanical alignment must be corrected at the same operative setting as the surgery to address the OLT. Grading the OLT allows for proper prognostication and influences whether the lesion can be approached with an antegrade or retrograde technique.

Intraoperative Details

Surgical exposure

When anterolateral osteochondral lesions of the talus (OLTs) are treated, open surgical exposure is accomplished via an anterolateral approach to the ankle joint. Plantarflexion aids in exposing the lesion; however, this approach requires caution to avoid damaging the branches of the superficial peroneal nerve.

The open approach is also challenging when treating posteromedial OLTs. An osteotomy cut that enters the joint too far laterally can endanger the weight-bearing plafond, and a cut that enters the joint too far distally on the medial malleolus limits exposure. Screw holes must be predrilled before osteotomy. In addition, care must be taken to avoid injury to the allograft nerve and vein, anterior tibial tendon, posterior tibial tendon, flexor digitorum longus (FDL), posterior tibial artery, and tibial nerve.

An apex proximal chevron bone cut provides excellent visualization, and Cohen et al had no nonunions or malunions when using a chevron medial malleolar osteotomy in 19 patients.^6,31

Posteromedial OLTs have also been treated by using a combined anterior and posterior arthrotomy exposure. This approach allows access to 80% of the talar dome while it avoids the medial malleolar osteotomy in most cases.³²

Arthroscopic treatment of OLTs can be accomplished using wide-angle 2.7-mm arthroscopes, which provide more maneuverability than traditional 4- and 5-mm arthroscopes. Noninvasive joint distraction techniques enable easier visualization of the entire talar dome.^33,34,35,36

Treatment of a completely detached lesion

For a completely detached lesion believed to be inappropriate for internal fixation, removal of the loose body and debridement of the bony bed are indicated. The base of the bed should be debrided back to bleeding bone, and the edges should be trimmed back to viable cartilage. Instruments available for use in this procedure include blunt-tipped probes, pituitary graspers, gouges, Kirschner wires, awls, full-radius shavers, ring curettes, and high-speed burrs. Studies have shown that excision and nonoperative treatment yield poor results, and that excision, curettage, and drilling provide the best outcome.³⁷

Treatment of intact lesions

Drilling of the subchondral bone creates channels to enable revascularization of the fragment. Drilling can be accomplished using existing arthroscopic portals, a curved meniscus-repair needle guide, and transmalleolar drill holes.^22,38

Sinus tarsi approaches to posteromedial lesions, also known as retrograde drilling or transtalar drilling, do not disrupt the articular surface. Retrograde drilling can facilitate bone grafting, which is ideal for large subchondral cystic lesions with intact articular cartilage. The COLT (Interpore Cross, Irvine, Calif) provides for accurate positioning of the drill hole and a cannula for bone graft delivery. Studies have shown good clinical and radiographic results using transarticular/transmalleolar drilling and retrograde/transtalar drilling.^39,40

Internal fixation

The use of traditional bone screws passed in an antegrade fashion is discouraged because irreparable damage to the intact articular cartilage results. Screw fixation typically is used for anterolateral lesions only because of the difficulty in gaining good exposure for posteromedial lesions. Kirschner wires can be inserted retrograde through a nonarticular portion of the talus. Bioabsorbable pins can be advanced immediately below the articular surface, then cut off at the skin.

Bone grafting

The authors have reported successful fixation after autogenous osteochondral grafting of an osteochondritis dissecans of the knee.⁴¹ Another report described treating 27 large (8 mm × 8 mm and larger) ankle lesions with a cortical bone peg technique.⁴² The pegs, which were 2-3 mm wide and 15-20 mm long, were harvested from the distal tibia and passed through the articular surface. They reported good clinical results in 89% of their patients at an average of 7 years of follow-up.

Another study, with an 11-year mean follow-up, reported 9 cases of fresh osteochondral allografting.⁴³ Of 9 grafts, 6 remained in situ, and 3 patients required ankle arthrodesis because of resorption and fragmentation of the graft. These authors discourage the use of allografting in OLTs. A high rate of complications have been reported in patients who underwent tibiotalar osteochondral allografting.⁴⁴

Autologous osteochondral grafting (OATS, mosaicplasty)

These techniques involve grafting a plug from the femoral trochlea or condyle into the OLT on the talar dome.⁴⁵ The OATS procedure transplants a single plug into the OLT, and mosaicplasty is used to harvest and transplant multiple plugs.⁴⁶ Single-plug grafts result in reduced ingrowth of the fibrocartilage, although donor-site morbidity may be greater because of harvesting a single, larger plug. The mosaicplasty procedure is said to provide a better match to the talar dome contour and surface area of the defect, although 20-40% of the defect is filled with fibrocartilage.⁴⁷

Several groups have reported good results using both procedures. Eleven patients who underwent mosaicplasty had good-to-excellent results at 24 months.⁴⁸ The lesions averaged 18 mm × 10 mm, and there were no adverse effects on the knee. Another study reported that 94% of 36 patients undergoing mosaicplasty had good-to-excellent results, with follow-up ranging from 2-7 years.⁴⁹ Previous surgical procedures had failed in 29 of the patients.

In another study, plugs were harvested from the ipsilateral medial or lateral articular facet of the talus in 12 patients. Significant improvement in American Orthopaedic Foot and Ankle Society (AOFAS) scores was reported, and no structural failures occurred in the graft or donor site.⁵⁰

Autologous chondrocyte transplantation

Two reports described good early results with autologous chondrocyte transplantation (ACT). Koulalis et al reported the results of ACT in 8 patients, with an average follow-up of 17.6 months.⁵¹ Patients first underwent diagnostic arthroscopy, cartilage biopsy, chondrocyte extraction, and culture. An average of 2.5 weeks later, arthrotomy, malleolar osteotomy, bone debridement, and chondrocyte transplantation were performed. Patients were kept on non–weightbearing status for 6-7 weeks. Routine arthroscopic examination performed 6 months after the transplant showed cartilagelike tissue completely covering the OLTs. (Histologic examination of 1 biopsy sample did not show hyaline cartilage.)

Giannini et al reported similar results 24 months posttransplant, showing that hyaline cartilage can be transplanted in the ankle joint and that good function can be expected.⁵²

ACT has been performed more often in the knee. Results of the first 100 patients undergoing this procedure in a multicenter, 5-year study found that 79% showed improvement at 5 years. Compared with a control group undergoing different procedures, such as drilling or abrasionplasty, patients undergoing the transplant procedure had better functional outcomes.⁵³

Coexisting OLT and ligamentous instability

Acute ankle ligament injuries with a large, unstable fragment typically first undergo surgical repair of the talar lesion. The ligament is allowed to heal postoperatively.

Treatment decisions for treating chronic OLTs with chronic ankle instability are less clear. Postoperatively, OLTs require early motion, which is not appropriate for reconstructed ligaments. Options include first repairing the OLT and then repairing the ligamentous injury at another time, or repairing the 2 injuries simultaneously and postponing early ankle motion until the ligament has healed. Thermal capsular shrinkage may also be a possible treatment solution.⁴¹

Postoperative Details

A postoperative rehabilitation program should be tailored to each patient's individual circumstances and goals by a licensed physical therapist. Rehabilitation can generally begin after healing is demonstrated, which may occur after 6-7 weeks of non–weightbearing status if drilling or internal fixation was performed. With the goal of attaining full ankle range of motion, physical rehabilitation includes active and passive range-of-motion exercises and a home program, edema control, and strength and proprioceptive training.

Follow-up

Pain following operative treatment of OLTs is common for up to a year. MRI changes, including edema, are slow to resolve and often match the patient's report of an achy feeling in the joint. After 6 months, a persistent effusion, a catching sensation, or severe pain signifies that healing is not progressing as intended, and further investigation with CT or MRI is appropriate.

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center and Imaging Center. Also, see eMedicine's patient education articles Ankle Arthroscopy, Understanding X-rays, and Magnetic Resonance Imaging (MRI).

Complications

Operative treatment for osteochondral lesions of the talus (OLTs) has inherent risks. Open exposure entails use of a medial malleolar osteotomy or anterior plafond bone block to gain exposure of the tibiotalar joint. The medial malleolar osteotomy typically heals well with low incidence of nonunion, but care must be taken to place the osteotomy correctly and protect the adjacent tendons and neurovascular structures.³¹ An anterior tibial bone-block access window is associated with a lower risk of malunion but may limit access to posterior lesions.⁵⁰

Arthroscopic intervention is associated with less surgical morbidity and joint stiffness, decreased rehabilitation time, and an increased functional outcome.⁵⁴

Schuman reviewed 22 patients who underwent arthroscopy with curettage and drilling at an average follow-up of 4.8 years, with 86% good-to-excellent results.⁵⁵ Complications associated with arthroscopy include hyperesthesia around the portal incision and, occasionally, neuralgia of the superficial peroneal nerves, but these were minor and transient.

Some have advocated the use of allograft implants, but these grafts may become resorbed over time and fragment, necessitating the need for ankle arthrodesis.⁴³ So far, no reports have been made of allograft rejection by the host.

The osteochondral transplantation procedures have the additional risk of a second surgical site, which adds to the risk of possible complications. A 4-year follow-up of 36 mosaicplasty patients reported 6 patients with donor-site complaints during strenuous exercise, but this resolved after the first year.⁴⁹ The osteochondral autograft transfer system (OATS) procedure is thought to have greater donor-site morbidity, since larger plugs are taken than those taken with the mosaicplasty.

Gautier et al evaluated 11 patients at a 24-month follow-up and found 10 of 11 had graft incorporation and were without major complications.⁴⁸ Subjectively, patients may report mild pain or stiffness in the knee or ankle, but this is without objective deficits. Similarly, other authors have found good graft incorporation without serious complications.^5,49 Restoration of articular surface congruity may be very difficult, particularly in talar shoulder lesions.

Autologous chondrocyte transplantation (ACT) is relatively new, and published reports are few but include good results.⁵¹ The procedure does necessitate 2 operations and is difficult technically, but no complications have been reported.

• Search for CME/CE on This Topic »

• Ankle Arthroscopy (Orthopedic Surgery)

• Imaging Center
• Understanding X-rays
• Foot, Ankle, Knee, and Hip Center
• Ankle Arthroscopy Introduction
• Magnetic Resonance Imaging (MRI)