Operative treatment is indicated in those patients with symptomatic OLTs that have failed initial conservative treatment efforts and those with acute, displaced fragments. Reparative methods focus on bone marrow stimulation (microfracture), tissue transplantation with autograft or allograft transfer system, autologous chondrocyte implantation, hyaline cartilage grafts, and biologic augmentation.

Bone marrow stimulation techniques include debridement, microfracture, antegrade drilling, or retrograde drilling. These techniques are often considered first-line treatment for primary osteochondral lesions up to 15 mm in diameter [17–24]. This treatment is primarily performed arthroscopically and involves excision of the OLT to a stable cartilage border. Multiple drill holes in the subchondral bone spaced 3–4 mm apart then allow mesenchymal stem cells and growth factors to form a fibrocartilage cap comprised primarily of type I collagen [25, 26]. Native hyaline cartilage , however, is primarily comprised of type II collagen, while type I collagen contains different mechanical and biological properties that have been shown to degenerate over time [27]. This can be one of the primary reasons for a patient to have a failure of a primary microfracture procedure.

Outcomes of marrow stimulation techniques have been reported, with good to excellent results, in 65–90% of patients [15, 18, 22, 28–34]. Many clinical factors have been described to be predictive of patient outcome. These factors include size of lesion, patient age, bony edema on MRI, and cystic nature of lesion [35]. Size of talar lesions less than 15 mm in diameter has shown to have superior clinical outcomes. Patient aged less than 18 years old also has shown better outcomes than older patients with microfracture and drilling. Lastly, improved clinical symptoms postoperatively correlate when patients exhibit a lower intensity of bony edema on MRI.

Osteochondral autologous or allograft transplantation systems (OATS) are indicated in large primary lesions or failed secondary lesions [17, 36–39]. In the OATS procedure , the OLT is replaced with a single osteochondral plug or multiple plugs (mosaicplasty) with an intact hyaline cartilage surface. The graft can be harvested from the ipsilateral knee or from a fresh allograft talus. The advantages of this system include replacing the defect with hyaline cartilage rather than the formation of fibrocartilage with microfracture. Disadvantages, though, include an increase in donor site morbidity from an ipsilateral knee, healing of the host to graft interface, and the need for a malleolar osteotomy.

Favorable outcomes have also been reported with OATS, although most reports are retrospective studies. Hangody et al. reported a large case series of 1097 patients who received autologous osteochondral mosaicplasty , with 98 receiving the procedure in the talus [40]. Ninety-three percent of patients had good to excellent clinical results in the talus at a mean follow-up of 7 years.

Autologous chondrocyte implantation (ACI) is a two-stage procedure involving the transplantation of cultured chondrocytes into a defect and sealed with a periosteal patch. The first procedure harvests hyaline cartilage cells from the talus or the knee, while the second procedure involves injection of the cell suspension under a sutured periosteal flap harvested from the distal end of the tibia [41]. Recent advances to the technique include a procedure using matrix-induced ACI (MACI). This utilizes a porcine collagen membrane carrier for chondrocytes, which is injected into a defect and secured with fibrin glue. Reduced operative times, elimination of a periosteal patch, and an even distribution of cells are potential advantages of the MACI technique , although this is not available in the United States [42].

Particulated juvenile articular cartilage graft (DeNovo® NT Natural Tissue Graft, Zimmer, Warsaw, IN) is a new technique that was first published which is used in the patella in 2007 [43]. This novel product uses scaffold-free allogenic juvenile cartilage that can be implanted into a lesion with a fibrin sealant. The cartilage graft has shown the ability to migrate, multiply, and form new hyaline-like cartilage tissue matrix that integrates with the surrounding host tissue [44]. The largest study to date for use in the foot and ankle was published by Coetzee et al. and demonstrated 78% of patients with good to excellent functional results with an average postoperative AOFAS scores of 85 at mean follow-up of 16.2 months in patients with lesions greater than 125 mm² [45].

Osteochondral autograft and allograft procedures raise concern over the viability of the transplanted cartilage and the ability to incorporate a large graft-host bone interface. A considerable risk of graft collapse, graft resorption, and joint space narrowing exists when performing these procedures. If this procedure fails, chronic pain and debilitation leave both the surgeon and patient with few options for salvage. Surgical reconstruction options for an osteochondral autograft or allograft failure include conversion to a total ankle replacement, ankle arthrodesis, or bipolar total ankle allograft.

When autograft and allograft transfer procedures are performed, long-term monitoring of the graft should be employed. Gross et al. reported a case series of nine patients who underwent fresh talar osteochondral allograft transplantation with a mean follow-up of 11 years [57]. Three of the nine grafts demonstrated radiographic evidence of fragmentation and resorption of over 50% of the graft with secondary osteoarthritic changes at an average of 58.3 months postoperatively. The three patients with graft failure required conversion to an ankle arthrodesis.

In 2009, Raikin reported his results on 15 patients who underwent bulk fresh osteochondral allograft transplantation for cystic talar defects [58]. Two of fifteen patients required ankle arthrodesis procedures following graft resorption and joint space narrowing at 32 and 76 months postoperatively.

Additionally, Adams et al. reported midterm results on talar shoulder lesions treated with fresh osteochondral allograft transplantation in eight patients [52]. They observed radiographic lucency at the interface of the allograft and host bone in five of the eight patients at an average follow-up of 2 years. No patients, however, were converted to an ankle arthrodesis, but one required two arthroscopic debridement surgeries. They also concluded that long-term monitoring of the grafts is required, and perhaps the radiographic lucency seen in their patients was due to early resorption.

Lastly, El-Rashidy et al. found graft failure in four of forty-two patients who underwent fresh osteochondral allograft transplantation for chronic talar lesions with an average follow-up of 37.7 months [59]. This resulted in two patients undergoing total ankle replacement, one ankle arthrodesis, and one bipolar total ankle allograft.

Open exposure of the talus requires the use of a medial malleolar osteotomy or anterior plafond bone block. The medial malleolus typically heals well with a low incidence of nonunion; however, care must be taken to place the osteotomy in the correct position with protection of the adjacent neurovascular structures and tendons. Kim et al. revealed decreased patient outcomes on second-look arthroscopy when the tibial plafond at the malleolar osteotomy site was uneven [49]. Alternatively, an anterior access bone block window may be utilized; however, this limits the access to posterior talar lesions [60]. If a malleolar nonunion or malunion is encountered, revision surgery with anatomic alignment and bone grafting is often necessary. In these cases, additional medial anti-glide plate should also be employed for added stability.

Debridement and microfracture of an OLT is a successful procedure; however, intraoperative technique may play a role in obtaining a favorable result. Enhanced arthroscopic equipment and instrumentation allow the talar dome to have increased visualization. At our institution, general inhalation anesthesia with a regional nerve block and a thigh tourniquet is used routinely. Noninvasive ankle distraction is also utilized for easy arthroscopic access to accomplish a proper microfracture technique (Fig. 26.6). Additionally, a cystoscopy thigh holder allows the ankle to be suspended for easy use with distraction (Fig. 26.7). Standard anteromedial and anterolateral portals are utilized with a 2.7- or 4.0-mm diameter and 30° or 70° arthroscope. Plantarflexion aids in exposure of posterior lesions; however, this maneuver requires caution to avoid damaging the branches of the superficial peroneal nerve. In cases with extreme posterior lesions, a posterolateral accessory portal can also be used. For most medial-based talar dome lesions, the arthroscope and inflow enter through the anterolateral portal, while the instrumentation for debridement is through the anteromedial portal. Lateral talar dome lesions are best approached with the arthroscope and camera in the anteromedial portal with instrumentation through the anterolateral portal. Instruments available to debride osteochondral lesions include blunt-tipped probes, pituitary graspers, gouges, full-radius shavers, ring curettes, and high-speed burrs (Fig. 26.8). Appropriate angled microfracture chondral awls or Kirschner wires should be used to ensure a stable drill is performed with the proper depth (Fig. 26.9). The surgeon should also be sure not to skive off the talus and cause damage to healthy cartilage with the chondral awl. Multiple drill holes of the talar lesion should be performed with a minimum of 3- to 4-mm intervals [61]. Additionally, the inflow pump can be reduced in order to visualize fat droplets and blood return out of microfracture holes to ensure adequate depth into the subchondral bone has been reached with the awl (Fig. 26.10).