Page 28 - ISAKOS 2018 Winter Newsletter

CURRENT CONCEPTS
Talar Osteoperiosteal Grafting From the Iliac Crest (TOPIC): A Novel Surgical Technique for Large Primary and Secondary Osteochondral Defects of the Talus
01A Step 3: Microdrilling the Subchondral Bone
01D
Next, a medial malleolar osteotomy is performed through a curved incision (approximately 7 cm) over the medial malleolus (Fig. 1-A).
Once the large saphenous vein has been identified and protected, the anteromedial joint capsule is opened and the surgeon makes a dorsal incision of the posterior tibial tendon retinaculum, after which the tendon is inspected and retracted.
In order to allow the medial malleolar osteotomy site to be closed with 3.5-mm stainless steel cortical screws, two 2.5-mm holes are drilled and tapped in the medial malleolus. An osteotomy is then performed perpendicular to the cortex with use of an oscillating saw (Fig. 1-B). Then, the medial malleolus is held plantarly by means of a K-wire, thereby exposing the talar surface and talar osteochondral defect.
Step 2: Excision of the Diseased Osteochondral
Talar Fragment
The talar osteochondral lesion is exposed to facilitate the incision. The cartilage is incised in a rectangular fashion in order to preserve as much healthy cartilage as possible. All necrotic and cystic bone is excised in toto with use of an oscillating saw and a chisel/osteotome with thin blades (Fig. 1-C). The end result should be a cube-shaped hole in the talus, deep enough so healthy bone can be seen (Fig. 1-D).
01B 01C
The host site can be prepared with a 2-mm drill so that a bone-marrow-stimulation process will take place. This particular step of the procedure subsequently results in the disruption of intraosseous vessels, which introduces bone marrow cells into the empty defect (Figs. 2-A and 2-B).
02A 02B
Step 4: Harvesting the Graft from the Iliac Crest
Once Step 3 has been finalized, harvesting of the graft can be initiated. After microdrilling, and just before the actual harvesting, the surgeon measures the size of the excised block with use of a ruler so that a precise excision of an autograft of the correct size can be performed.
Along the palpable iliac crest, a horizontal incision of approximately 5 cm is made, after which the bone is exposed with use of 2 retractors. The surgeon then uses an oscillating saw to harvest a cortical osteoperiosteal autograft from the iliac crest. The graft is then excised and transported to a sterile table in the operating room for further adjustments in size and shape (Fig. 3-A).
Step 5: Adjusting the Size and Shape of the Harvested Graft to the Diseased Fragment
Adjusting the size and shape of the harvested graft is an important step that can impact the clinical success of the TOPIC procedure. First, the harvested graft is compared with the excised talar osteochondral fragment (Fig. 3-B).
26 ISAKOS NEWSLETTER 2018: VOLUME I