Risks of Keyhole Meniscus Surgery: A Study of 700,000 Procedures
Key points
- This study analysed around 700,000 keyhole meniscus operations (arthroscopic partial meniscectomy) across England over 20 years – the largest safety study of its kind.
- Overall the operation is low-risk: serious complications occurred in about 1 in 315 cases (0.32%).
- The risk of complications rose with age and with other health conditions.
- Rates of death, heart attack and stroke were lower than in the general population, but blood clots on the lung and joint infection were higher – and did not fall over the 20-year period.
- The findings support careful, informed discussion about whether meniscus surgery is worthwhile, especially where the expected benefit is uncertain.
What Was This Study About?
Arthroscopic partial meniscectomy – a keyhole operation to trim a torn meniscus (cartilage) in the knee – is one of the most common orthopaedic procedures worldwide. In this study, I set out to provide the most comprehensive picture yet of the serious risks associated with this operation, using NHS hospital data covering the whole of England over a 20-year period.
We analysed approximately 700,000 isolated arthroscopic partial meniscectomy procedures performed between 1997 and 2017, using the national Hospital Episode Statistics database linked to mortality records. This is the largest study of its kind ever reported for this specific operation.
What Did We Find?
Overall, arthroscopic partial meniscectomy is a low-risk procedure. Serious complications – including heart attack, stroke, blood clot in the lung, infection requiring further surgery; occurred in approximately 1 in 315 cases (0.32%).
Looking at individual complications within 90 days of surgery:
- Infection requiring further surgery occurred in roughly 1 in 740 cases
- Blood clot in the lung (pulmonary embolism) occurred in roughly 1 in 1,280 cases
- Death from any cause occurred in roughly 1 in 3,225 cases (less often than in the general population)
- Heart attack occurred in roughly 1 in 2,500 cases
- Stroke occurred in roughly 1 in 3,365 cases
We found that the risk of complications increased with age and with other health conditions. Patients aged 80 or over had a complication rate roughly six times higher than those aged 40–59. Patients with significant existing health problems also faced substantially higher risks.
An important finding was how the risks compared to the general population. The rates of death, heart attack, and stroke were actually lower in patients who had the operation than in the general population of the same age – likely because surgeons tend to select relatively healthy patients for this procedure. However, the risks of blood clots in the lung and knee joint infection were significantly higher than in the general population, and these elevated risks did not diminish over the 20-year study period despite improvements in preventive care.
Why Does This Matter for Patients?
This study provides important information for anyone considering meniscus surgery. It shows that while the operation is generally safe, it is not without risk – and those risks are higher for older patients and those with other health conditions.
The findings are particularly relevant given ongoing debate about when meniscus surgery is worthwhile. Several clinical trials have questioned the effectiveness of this operation for some types of meniscal tears, particularly degenerative tears in middle-aged and older patients. When the expected benefit of a procedure is uncertain, the potential for rare but serious complications becomes an important part of the conversation.
These data have been widely used to support better-informed consent discussions, and have contributed to national guidelines on when meniscus surgery should and should not be offered.
Frequently asked questions
Is keyhole meniscus surgery safe?
Generally yes. In this study of around 700,000 procedures, serious complications occurred in about 1 in 315 cases (0.32%), so arthroscopic partial meniscectomy is a low-risk operation for most people. The risk is higher for older patients and those with other health conditions.
What are the main risks of arthroscopic meniscus surgery?
Within 90 days of surgery the study found, approximately: infection requiring further surgery in about 1 in 740 cases; a blood clot on the lung in about 1 in 1,280; heart attack in about 1 in 2,500; death from any cause in about 1 in 3,225; and stroke in about 1 in 3,365.
Who is most at risk of complications after meniscus surgery?
Older patients and those with existing health problems. Patients aged 80 or over had a complication rate roughly six times higher than those aged 40 to 59.
How do the risks compare with the general population?
The rates of death, heart attack and stroke were actually lower than in the general population of the same age, probably because surgeons tend to select relatively healthy patients. However, the risks of a blood clot on the lung and knee joint infection were higher than in the general population, and did not fall over the 20-year study period.
Should I have surgery for a meniscal tear?
It depends on your symptoms and the type of tear. Where the expected benefit is uncertain, as is often the case with degenerative tears in middle-aged and older patients, the small but real risks of surgery become an important part of the decision. This is best discussed individually with your surgeon.
Read the Full Paper
This paper is published open access in The Lancet under a Creative Commons licence. You can read the full text below, or on the Lancet website or PubMed Central.
Full citation: Abram SGF, Judge A, Beard DJ, Price AJ. Adverse outcomes after arthroscopic partial meniscectomy: a study of 700,000 procedures in the national Hospital Episode Statistics database for England. The Lancet. 2018;392(10160):2194–2202. doi:10.1016/S0140-6736(18)31771-9
This summary is written for general information and explains the research in patient-friendly terms. It does not replace individual medical advice. If you have questions about your knee or a meniscal tear, please get in touch to arrange a consultation.
