Tori Roloff Says It's 'Scary' Knowing Son Jackson, 4, Will Need Leg Surgery in 'LPBW' Sneak Peek

Zach Roloff and Tori Roloff's 4-year-old son Jackson will need to get surgery on his legs, the couple learns in PEOPLE's exclusive sneak peek at Little People, Big World

Tori Roloff and Zach Roloff are facing the reality that their 4-year-old son Jackson will need leg surgery at some point.

In PEOPLE's exclusive sneak peek at Tuesday's episode of Little People, Big World, the pair, who are also parents to daughter Lilah, 18 months, discuss the options for Jackson after learning from a doctor that the bowing in his legs will require an operation.

"I'm watching Lilah while Tori brings Jackson to his leg appointment, very curious to see is it like severe or not severe, is this normal, not normal," Zach, 31, begins in the clip. "I hope his legs don't need major surgery, so I'm very curious to know where we're at on this."

The dad of two then calls Tori, 30, for a status update from the doctor's office. Jackson tells Zach via video chat that he took "pictures" (x-rays) before adorably showing him a thumbs up and letting him know, "I got it dad!"

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Jackson Roloff. TLC

Tori, meanwhile, updates Zach: "[The doctor] definitely said yes, there's bowing. It's just I think now a matter of do we do it now or do we wait? I'm assuming she's going to bring the x-rays in with her, we're going to go over it."

"The doctor says his legs are an issue but it's not an emergency," Zach later tells the cameras. "It's kind of deep down what I think I expected, it's all about deciding when, where and what the best surgery is. It's the beginning, I think, of a long journey."

"Hearing that Jackson's going to need surgery, that was heavy and that's going to be scary when that day is here," Tori adds. "But it's encouraging because his knee — which is where I believe they broke [Zach's] leg — his knees are pretty straight, it's the ankle that's very rounded on him so that could work in his favor, hopefully they only have to deal with one spot instead of two spots."

Zach and Lilah. tlc

She continues, "From what I understood it sounded like he was a good candidate for scraping the growth plate and hopefully avoiding a major surgery."

Zach, who has had various surgeries himself, explains what growth plate scraping is. "Scraping the growth plate is one of the procedures I had done," he says. "The growth plate is some tissue at the top of the bone, by scraping it, you're slowing future bone growth."

"It's still a big surgery but there's no breaking of bones," Tori notes. The second option — "actually breaking the bone and, like, making the bones straight," she says — requires a longer recovery time. "It's two months, he's in a full on cast, wheelchair situation and then he like basically has to relearn how to walk," Tori explains.

Little People, Big World airs Tuesdays (9 p.m. ET) on TLC.