Osteochondral Ankle Surgery: Is This What Shin-Soo Choo's 'Torn Ankle Cartilage Surgery' Was All About?

ARLINGTON, TX - AUGUST 12: Shin-Soo Choo #17 of the Texas Rangers hits in the ninth inning against the Tampa Bay Rays at Glob
ARLINGTON, TX - AUGUST 12: Shin-Soo Choo #17 of the Texas Rangers hits in the ninth inning against the Tampa Bay Rays at Globe Life Park in Arlington on August 12, 2014 in Arlington, Texas. (Photo by Rick Yeatts/Getty Images)

What started as a sprained ankle back in April for Texas Ranger Shin-Soo Choo, has now progressed into surgery to repair/remove "torn ankle cartilage." The details regarding the surgery are limited, but as a Manhattan reconstructive foot and ankle surgeon it's my guess is that he had osteochondral lesion repair surgery. Questions have arisen as to why one would wait five months to have surgery after an acute injury, but often with certain cartilage injuries surgery is not the first option.

What is an Ankle Osteochondral Injury
The ankle joint, like all joints, is lined with cartilage, which allows for two or more bone segments to smoothly glide on one another. Cartilage is a cushy substance that is attached to the underlying the bone at the joint level. Injury to the ankle joint could also injure the cartilage which could be in the form of a bruise, tear/split and/or complete separation. The damage can be small or quite large. These cartilage injuries are medically known as osteochondral injuries

Ankle sprains are well known to injure cartilage as the force of an injury may cause the ankle bones to scuff against each other and focally damage the cartilage. Sometimes the force can be large enough to shear off the cartilage along with a small portion of bone as well.

There are predictable injury patterns that occur based on their location with the ankle. Injuries on the inside of the ankle are called medial osteochondral lesions, and those on the outside are called lateral osteochondral lesions. Medial lesions are generally more troublesome as the cartilage damage is usually deeper in the ankle and has more depth, whereas the lateral lesions are more superficial.

How Are Osteochondral Injuries Diagnosed?
Ankle xrays are the first test to evaluate for injury to the bone. Cartilage is not visible on xrays, but sometimes can be identified if the bone is also injured. Longstanding osteochondral injuries may deteriorate underlying bone which could make them visible on xrays. Otherwise, MRI is the best study to evaluate cartilage and therefore osteochondral injuries.

Ankle Osteochondral Surgery
Osteochondral injuries dont always require surgery, and depending on the extent of the injury. Surgery is rarely recommended immediately unless the cartilage damage is unstable which could further damage the remaining joint if the fragment dislodged. Its common for surgeons to wait one to six months to see if the cartilage injury can heal on its own.

Osteochondral ankle surgery is generally performed using ankle joint arthroscopy. This means that surgeons use small tools and cameras surgeons gain access into the ankle joint to remove scar tissue and work on cartilage issues. The method of cartilage repair depends on the overall extent and chronicity of the lesion. Most of the time, the injured segment of cartilage is removed and the underlying bone is roughened up to allow for new replacement cartilage to grow. More advanced techniques may involved cartilage bone plugs or cartilage implantation - but these are generally for larger chronic lesions.

How Will Choo Do?
If Shin-Soo Choo did indeed have an osteochondral injury, the prognosis greatly depends on the severity of the injury. It generally seems responsible to not jump into ankle cartilage surgery, which seems to be the case with Choo. Because he requires surgery 5 months later, does not particularly suggest a worse outcome. His outcome will mainly depend on just how much cartilage damage he had after he sprained it. Osteochondral injuries can progress onto ankle arthritis in the long term but there is no indication at this point that is anywhere on the horizon for Choo.

Dr. Neal Blitz
Reconstructive Foot & Ankle Surgery
New York City

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