Jockey Stathi Katsidis is expected to be sidelined for up to three months after breaking his leg in a track mishap.

Katsidis is due to be released from Redlands Hospital on Brisbane's bayside on Thursday following surgery to have a rod and plate inserted to mend a compound fracture of his left femur.

Katsidis suffered the injury when he was dislodged from a horse at Pinnacle Park near Beaudesert, south of Brisbane, last Friday.

The dual premiership-winning jockey has been working as a breaker at Pinnacle Park for the past six months after stewards withdrew his licence for nine months following a positive test to ecstasy.

"I was really excited about returning to the track and I had completed all the courses to get back to riding," Katsidis said.

"Everything was in place for my return when a horse reared up and I lost my balance.

"All of a sudden I was on my back but the pain wasn't too bad at first.

"It was a compound fracture of the femur and the doctors have inserted a rod and plate.

"At first I thought it would mean two or three years out and I was in a bit of shock.

"I'm on crutches now but the doctors are happy with my progress."

Katsidis' mishap followed another track accident at Doomben last week when former jockey Les Harris broke his leg when he was dislodged from the Brian Wakefield-trained Frosty during trackwork.

Katsidis has vowed not to let his latest setback disrupt plans to return to the saddle.

"The doctors think it will be about three months before I'll be back but I'm hoping it'll only be two," he said.

"I've been working hard for the last six months breaking in horses and I'm no longer on the drink.

"I've been off the grog now for six weeks. I've never touched drugs without first having a few drinks so if I stay sober I won't go near drugs again."

Meanwhile, last year's leading Brisbane jockey Jim Byrne will also be sidelined for the next few weeks after deciding to have corrective surgery to an old injury.