Colts’ GM Chris Ballard dismissed the idea that the os trigonum is the cause of Andrew Luck’s nagging injury Tuesday, as claimed by Colts’ owner Jim Irsay earlier in the week. Ballard said the team thought the os trigonum could be an issue but it was recently ruled out.
Still, many Colts fans were left wondering what exactly the small bone in the ankle is and why it was the potential culprit of their star quarterback’s injury woes.
OrthoIndy’s Dr. Jonathan Shook, an orthopedic surgeon specializing in sports medicine, most commonly sees the os trigonum flaring up in soccer players, though the bone is only present in 5-10% of the population according to multiple medical journals and websites. Shook, who has not examined Luck, says the bone does not always cause pain, but can be aggravated if the ankle area is stepped on or pushed off of in a funny way.
“The thought process behind it is that it is a portion of a bone in the foot that just didn’t ever fuse all the way,” Shook said. “So part of the back of the bone, it doesn’t heal itself in all the way. Because it’s not fused, it can become loose and move around, which causes the aggravation.”
Os trigonum injuries can be difficult to diagnose, especially in sports like football where injuries to the bone are uncommon. Swelling of the os trigonum can be hard to find in an immediate MRI, which would have been the method used with the initial belief that Luck was dealing with a calf strain. The swelling of the bone takes time to develop and can only be found in subsequent MRIs.
The Colts do not believe Luck is dealing with an injury to the os trigonum, but the prospect of recovering from an injury to the bone was enough to worry Irsay when he was asked about Luck’s injury during his interview with Bill Polian.
Had Irsay’s diagnosis been correct, Luck and the Colts would have been faced with two options. The first would have been to rest Luck’s ankle in hopes the irritation in the area would subside.
However, if the os trigonum continues causing problems, surgery becomes the solution. The procedure is minimally invasive and simply removes the bone from its placement behind the Achilles tendon.
Shook estimates the recovery from such a surgery is four to six weeks, with the focus being put on dealing with potential scarring and stiffness. Because the patient does not have to wait for pieces to heal together, as is the case with ACL surgery, she or he is able to play sports and put stress on the ankle once the strength and flexibility is regained.
The Colts are now exploring other explanations for Luck’s absence from the majority of the Colts’ training camp. Ballard told reporters that it would be unlikely for Luck to play in the preseason.
Email sports reporter Tyler Kraft at TKraft@gannett.com. Follow him on Twitter or Facebook @bytylerkraft.
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