I was a member of the Australian Commission on Safety and Quality in Healthcare’s recent Knee Expert Advisory Group, looking at knee arthroscopy and OA. The group included members from orthopaedics, rheumatology, sports medicine, radiology, general practice, nursing, physiotherapy, and consumer representatives.
Over a year we examined the research regarding arthroscopies, other interventions for knee OA, lead body position statements and more.
Background
Knee arthroscopies are commonly performed in Australia for knee pain in older patients.
Most patients have degenerative knee disease (i.e. osteoarthritis). High quality RCT data has been emerging for many years suggesting that knee arthroscopies are no better than placebo in improving function and pain beyond six months.
It has been shown that knee arthroscopies are no better than placebo for:
- OA,
- OA with degenerative (the vast proportion of) meniscal tears,
- Degenerative meniscal tears without OA, and more recently,
- OA and meniscal tears with mechanical symptoms.
This fourth point was first examined just last year and came as quite a surprise to many, challenging the assumption that mechanical symptoms was a ‘no brainer’ indication for referral for arthroscopy, as catching or locking was believed to result from a mechanical blocking mechanism in the knee.
Trial evidence
Looking at mechanical symptoms, Sihvonen (2016) and his Osteoarthritis Research Society International (OARSI) colleagues studied patients from one public hospital referral centre during 2007-2011 with non-traumatic onset of symptoms and having OA and a meniscal tear. 328 of 932 patients had mechanical symptoms pre-surgery. Mechanical symptoms were assessed using the self-reported Lysholm knee score: (1) no locking or catching, (2) catching sensations but no locking, (3) occasional locking, (4) frequent locking, or (5) locked at present. Those reporting no mechanical symptoms (response 1) were compared to those reporting mechanical symptoms (scores 2-5).
The proportion of patients satisfied with their knee 12 months after arthroscopy was significantly lower among those with preoperative mechanical symptoms (61%) than among those without (75%), and similarly improvement was also lower in the mechanical group. There was no difference found in quality of life or pain. Of those with preoperative mechanical symptoms, 47% reported persistent symptoms at 12 months postoperatively.
So does anyone with a degenerative knee benefit from arthroscopy? Maybe a smaller subset of more significant mechanical symptoms? Well, perhaps, but there has been no research studying only locking or severe catching, or some other subset of mechanical symptoms. And if there are indeed some patients who benefit from arthroscopic debridement, we have no way of knowing preoperatively who they are.
Therefore, don’t think of arthroscopy as first line management, and imaging is mostly not required.
So what instead?
There is good evidence for the efficacy of weight loss, aerobic exercise, strength exercises, and adjuncts such as NSAIDs, appropriate analgesics, cortisone injections for short term relief and hyaluronic acid injection for medium term relief. Knee replacement surgery is indicated when conservative measures fail. Patient-centred individualised care should be offered, acknowledging that comorbidities are often present.
References available on request.
Questions? Contact the editor.
Author competing interests: nil relevant disclosures.
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