SANTA CLARA, Calif. — San Francisco 49ers running back Christian McCaffrey likely suffered a partial tear of his posterior cruciate ligament (PCL) when he came down hard on his right knee at the end of a long run in the second quarter of Sunday’s loss to the Buffalo Bills.
Dr. Paul Rothenberg, Director of Sports Medicine and Shoulder Surgery at Optum Orthopedic Institute in New Jersey, said the injury was “almost out of a textbook.”
“We call (PCL injuries) dashboard injuries because they’re common in car crashes,” Rothenberg said. “Someone’s sitting in the car with their knees bent 90 degrees and the knees hit the dashboard.”
McCaffrey’s right leg was in that sort of angle after he was tripped by Bills safety Taylor Rapp following an 18-yard gain. As Kyle Shanahan noted afterward, McCaffrey was inches away from breaking a long run and possibly scoring his first touchdown of the season.
Instead, the impact of McCaffrey’s knee hitting the surface likely pushed the shin bone back and created a tear in the PCL, which stabilizes the joint and is meant to prevent posterior translation. Rothenberg said PCL injuries are often linked with other knee ligament tears.
“The way that he tore his is one of the ways you can get an isolated tear of the PCL,” he said.
CMC likely injured his PCL on impact on this play. “We call (PCL injuries) dashboard injuries because they’re common in car crashes,” an orthopedist said. “Someone’s sitting in the car with their knees bent 90 degrees and the knees hit the dashboard.” More on the injury, his prognosis, etc. later..
— Matt Barrows (@mattbarrows.bsky.social) December 4, 2024 at 8:04 AM
After the play, McCaffrey went to the sideline, which is common for a tailback following a long run. After two more snaps, he was back on the field, took a handoff and then dropped to the ground before limping off and going into the locker room.
Rothenberg said he wasn’t sure why there would be a delayed reaction like that.
“I don’t know if it was adrenaline kicking in or if he thought it was just a sprain or something less severe until he really tried to put it to use,” he said. “That would be my best guess.”
That Shanahan said the 49ers don’t think McCaffrey needs surgery suggests that it’s a partial, not a complete, tear of the PCL. If he were treating someone with a similar injury, Rothenberg said he’d put that patient in a special brace immediately.
“And I would get him started in physical therapy right away to work on range of motion and strengthening, particularly of the quadriceps tendon and muscle,” he said. “And just monitor him very closely.”
Shanahan suggested that McCaffrey, who was placed on injured reserve Tuesday, would be out for six weeks. That means he’d miss the rest of the regular season but might be available should the 49ers make the playoffs.
Rothenberg noted that six weeks was on the early end of the range. He said a football player with a PCL sprain might be able to start doing football-like activities after four weeks. But as far as returning for a game?
“I would put more of a spectrum on it and call it six to 10 (weeks),” he said. “Because it depends on so many variables.”
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Rothenberg said there shouldn’t be any long-term issues with the injury. McCaffrey should be fine when the 49ers’ offseason program begins in the spring.
Because No. 2 running back Jordan Mason also is expected to go on IR this week with a high ankle sprain, the 49ers’ top tailback is now rookie Isaac Guerendo, who is averaging nearly 5.9 yards per carry this season.
The 49ers also plan to elevate Patrick Taylor Jr. from the practice squad and re-sign Ke’Shawn Vaughn to the practice squad. On Tuesday, they claimed former New York Jets runner Israel Abanikanda off waivers. Though Abanikanda, 22, played in a similar system in New York, it’s unclear how quickly he’ll be worked into the mix.
McCaffrey, meanwhile, missed the first half of the season while recovering from bilateral Achilles tendonitis, which plagued him in the summer. He seemed to be just reaching his stride Sunday when the injury occurred.
When Shanahan spoke to the media Monday, he had not yet met with McCaffrey, who had been busy getting an MRI.
“I just feel for him,” Shanahan said. “It was a real frustrating year for him. He worked his butt off to get back to this point. I think he was really feeling good and about to take off and just had that real unfortunate injury last night. So I know he’s as crushed as anyone, but he’ll get through this. He’s a hell of a player, hell of a person and an unbelievable 49er and he’ll be back stronger than ever next year to help us.”
(Photo: Timothy T Ludwig / Getty Images)
