Little People, Big World focused on a potentially giant problem this week.

The latest episode of this popular TLC reality show followed up on thhe previous installment, which found Zach and Tori Roloff both worried about the health concerns of their children.

Both four-year old son Jackson and 18-month old daughter Lilah were both born with achondroplasia.

This is most common form of dwarfism ... and also the same type that afflicts their dad and paternal grandparents.

On Tuesday's episode, the parents were force to talk about their options for Jackson after learning from a doctor that the bowing in his legs will require an operation at some point.

It's no longer a question of if, but when.

"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 explained on air.

"I hope his legs don't need major surgery, so I'm very curious to know where we're at on this."

Zach's dad, Matt, can only really walk with the help of crutches these days.

Due to his physical ailments, he's undegone 15 surgeries over the years.

On this latest episode, meanwhile, Zach proceeded to call his wife a status update from the doctor's office.

From there, Jackson told 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!"

Tori then provided a more specific, and unfortunate, update.

"[The doctor] definitely said yes, there's bowing," she told Zach.

"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 told 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."

At least it's one that Zach himself knows well, having had two procedures himself when he was a chilld.

"Hearing that Jackson's going to need surgery, that was heavy and that's going to be scary when that day is here," Tori said.

"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."

Tori continued:

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

Viewers of Little People, Big World often learn a lot by watching this program.

For example?

Zach detailed on this installment just what growth plate scraping is.

"Scraping the growth plate is one of the procedures I had done," he said.

"The growth plate is some tissue at the top of the bone, by scraping it, you're slowing future bone growth."

Any procedure for anyone can be frightening, but...

"It's still a big surgery but there's no breaking of bones," Tori said on air, adding that the second option ("actually breaking the bone and, like, making the bones straight) would requiresda 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 concluded.

Little People, Big World airs Tuesdays at 9/8c on TLC.