Life-changing joint surgery gives patients freedom of movement
Around 18,000 New Zealanders get new joints, mainly hips and knees, each year, with demand heading ever upwards. Warren Gamble talks to an orthopaedic surgeon about advances in the life-changing surgery, and the patients who benefit.
No-one moves very quickly in Richard Peterson's waiting room.
Some are on crutches. Others need a hand to get up from the chairs. The walk to his orthopaedic surgery office down a short corridor is a study in uncertain gaits – from a serious hobble to a slightly awkward or cautious stride.
Most are in their 60s and many have put up with pain and loss of function in their joints for years, until they decide or are told that something has to be done.
Typically, it's just the wear and tear of life that takes its toll on the protective cartilage that allows weight-bearing joints like hips and knees to move smoothly.
When the cartilage wears away, osteoarthritis sets in, damaging the underlying bone, causing pain and restricting movement. As the spring in the step winds down it has far-reaching limitations on people's enjoyment of life - everything from job performance to gardening, to playing with the grandkids.
When patients walk gingerly into Richard Peterson's office, it's usually after a referral from a GP and X-rays that confirm replacement surgery as the best option.
"Historically people were told to go away and come back when they are completely incapacitated. That's not the approach now," he says.
"I tell patients the risks and benefits of surgery. If they feel they are ready to proceed, then I'll do the surgery. I try to do what's in the patient's best interests."
Peterson, who operates in the public system and privately, says there is no question that demand is rising as the baby boomer generation hits the prime joint replacement age.
He carries out between 130 to 150 joint replacements each year. For the first time last year he performed more knee than hip operations, reflecting a nationwide trend.
He says the impact of the obesity crisis has not been felt as keenly in Nelson as in other centres. Latest figures in the national joint registry show the mean body mass index measurements for knee replacements is 31.2, considered obese; and for hips 28.1, considered overweight.
The good news for patients is that if and when you get through the barriers to access for replacement joint surgery, improved surgical approaches and techniques, technological advances and better recovery programmes are giving people improved outcomes.
In Nelson the journey starts before the operation. Peterson encourages patients to get on an exercycle to strengthen the muscles surrounding the joints before surgery. Overweight patients are encouraged to lose excess kilos. An upcoming trial at Nelson Hospital will see patients keep a diary, ticking off exercise and other goals, and getting professional help from dieticians before their operations.
Peterson says the approach to the surgery itself has also changed, geared now toward getting patients mobile as soon as possible.
In the past hip and knee replacements typically involved a blood transfusion, complete bed rest for the first week and a hospital stay of two weeks.
The average hospital stay in many centres is now around three days and patients are encouraged to stand and start walking within hours of surgery, helping speed their recovery and lessening the risk of blood clots and other complications.
In an audit of the last two years of practice, he has not performed a blood transfusion after joint replacement surgery.
Medication, including powerful morphine-like drugs, are minimised to decrease side effects like nausea, which also allows patients to get moving earlier. In hip and knee replacements, most patients will be given a spinal, not general anaesthetic.
Implant technology has also developed through it's a tricky business to assess the effectiveness of differing combinations of metals and plastics over a 20 to 30-year period.
Metal-on-metal hip replacements had supportive results in the laboratory but performed poorly in patients, damaging tissue and requiring revision surgery. The failure rates of metal-on-metal implants saw worldwide recalls in 2012 and 2013.
Peterson saw the warning signs of metal-on-metal hips while training in Canada eight years ago and has not used them in his Nelson practice.
However, other implants using hard metals like titanium and tantalum in combination with ceramic or plastic components are showing good results, with joint registry data showing approximately 95 per cent of patients have their original implants after 10 years. The New Zealand registry has not got to 20 years yet but overseas studies show between 80 per cent and 90 per cent retention after 20 years.
Peterson is also the orthopaedic lead surgeon in the enhanced recovery after surgery (ERAS) initiative in the top of the south, a Ministry of Health programme to boost rehabilitation.
Nelson already has the fastest discharge rates and the least readmissions for complications from joint replacement surgery in the country, so the focus here is on improving patient education and exercise programmes.
Quite apart from the professional rewards, Peterson relishes the interaction with patients and their "fantastic personalities". They include the West Coast farmer fascinated by the mechanical side of the operation, likening the bone-cutting saw to "a Makita", or the card he got from Nelson barber and hip replacement patient Shawn Storman which had a montage supportive comments from scores of his friends thankful for his successful surgery.
He appreciates the relief of patients who feel the difference from years of nagging pain, even a day after their operation.
"My two joint replacements the other day, they are looking at me saying, Richard this is fantastic and they are bending their legs up and saying 'I've got less pain today than I had yesterday' and it's day one after their operation.".
"You enjoy that, you enjoy the people and you enjoy seeing the difference you make."
He sees that difference in a small post-operation rite of passage that takes place in the same corridor where patients stepped warily a month before. "Invariably, they will lift their crutches up and hold them in the air and show how much improvement they've had. So that's pretty cool."
BY THE NUMBERS
Primary hip replacements
Primary knee replacements
Source: New Zealand Joint Registry