SINGAPORE – Pre-school teacher Yusmarni Mohammad Hasni was typing on her laptop in bed in May 2025 when she suddenly felt a sharp pain in her shoulder.
She had lived with chronic shoulder instability – a condition where her shoulder joint often slipped out of place – for 12 years after an injury during judo training in secondary school.
“It affected my daily life. For example, when I was holding on to a handle in the bus, my shoulder would just dislocate,” she said.
Over the years, she learnt how to push her shoulder back into the socket. But on that day in 2025, she was unable to do so.
“I tried to sit up, but I couldn’t,” said Yusmarni, now 27. “I was crying. It was my most painful experience yet.”
She sought treatment at Khoo Teck Puat Hospital (KTPH), where the orthopaedic surgery team decided to use a new keyhole surgery technique developed by the hospital to stabilise her shoulder and prevent future dislocations.
Yusmarni became the first patient in Singapore to undergo the surgery in August 2025.
Keyhole surgery is a minimally invasive method where the operation is done through small incisions. The technique uses smaller skin incisions than open surgery, leaving the patient with smaller surgical scars and less pain during recovery. It also allows surgeons to conduct the operation with more precision through better visualisation.
Although keyhole surgery has been used to treat shoulder instability since the 2000s, it is not widely practised due to its complexity, said consultant surgeon Chan Juen Zhik from KTPH’s shoulder, elbow and sports surgery service.
“Even for us, who do arthroscopic surgery almost day in and day out, the learning curve for this kind of procedure is still very steep,” Chan said, adding that he wanted to make it both simpler and safe.
The technique by KTPH involves making three small incisions of around 1cm to 2cm at the front of the shoulder, unlike keyhole operations elsewhere that are typically done through five or six frontal incisions, explained Chan.
Surgeons use an arthroscope – a small tube containing a camera – to better visualise and protect critical nerve areas.
To reduce the number of cuts, the team combined the placement of incisions in previous methods for greater precision, and used arthroscopes with different fields of vision.
During surgery, part of the bone from the shoulder blade is transferred to the damaged socket to address bone loss resulting from repeated dislocations. With the new approach, surgeons can also repair the soft tissue around the shoulder to give it more stability.
Chan, who developed the approach and performed Yusmarni’s surgery, said: “The new procedure makes a technically demanding surgery easier and more predictable while maintaining the benefits of keyhole surgery.”
He added that the technique can also improve the accuracy of the bone graft placement when surgeons are transferring the bone to the socket, reducing the risk of complications such as osteoarthritis.
KTPH’s head of department of orthopaedic surgery Timothy Teo Wei Wen, who is also a senior consultant at the sports, shoulder and elbow surgery division, said: “The main benefit is the improved visualisation.
“Traditionally, we do not repair the soft tissues during open surgery.
“But now, since we can get a view from within the shoulder joint, we can repair it very well. Basically, patients are getting a two-in-one procedure.”
While patients who undergo traditional surgical methods usually take up to six months to recover, Yusmarni bounced back in under three months while attending regular physiotherapy sessions at KTPH.
“After two to three weeks, I no longer needed painkillers,” she said.
Yusmarni is excited to try activities such as rock climbing and kayaking now that her shoulder is treated. The surgery has also given her more confidence at work, especially when she plays with the children.
“(Previously) I felt bad because I had to tell the children to be gentle, but now I get to play with them. I get to hold hands and run together with them, I don’t need to be cautious any more,” she said.
Since Yusmarni’s operation, KTPH’s surgeons have treated five other patients with the new technique, and they hope to shorten the operation time to below two hours. Currently, it takes around 2½ hours, while open shoulder surgery usually takes about 1½ hours.
Chan said KTPH will share its approach with other surgeons through its sports surgery fellowship programme. The innovation was also published in surgical journal Arthroscopy Techniques in May.
“We tried to keep this technique as simple as possible and make it less technically demanding so that more people can do this procedure,” said Chan, who hopes this will encourage more surgeons to offer the treatment to their patients.
