Partial meniscectomy – a form of arthroscopic surgery for patients with a torn meniscus, a rupture of the fibrocartilage strips in the knee – is ineffective for individuals with mechanical symptoms of degenerative knee.

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Researchers say that arthroscopic surgery does not alleviate mechanical symptoms for patients with a torn meniscus.

This is a conclusion of a new study recently published in The Annals of Internal Medicine, led by Prof. Teppo Järvinen, professor of orthopedics and traumatology at the University of Helsinki in Finland.

A torn meniscus is one of the most common symptoms of degenerative knee – the deterioration of the knee joint with age. It occurs when one of the two menisci in the knee – the C-shaped pieces of cartilage that protect and cushion the thighbone and shinbone – become damaged.

Many people with knee degeneration may experience mechanical symptoms such as joint locking or catching, which are often attributed to a section of the knee joint becoming lodged between the joint surfaces as a result of friction caused by a torn meniscus.

Prof. Järvinen and colleagues note that partial meniscectomy – the surgical removal of the damaged part of a torn meniscus – has become standard practice for patients with mechanical symptoms, despite there being insufficient evidence that it is beneficial.

“Orthopedists are largely unanimous on the benefits of arthroscopic surgery on patients suffering from mechanical symptoms. However, scientific proof of the benefits is scarce, and before our study, entirely based on uncontrolled follow-up studies,” says coauthor Dr. Raine Sihvonen, a specialist in orthopedics at the Hatanpää Hospital in Tampere, Finland.

For their study, the researchers set out to gain a better understanding of the effectiveness of partial meniscectomy for such patients.

The team analyzed the data of 146 patients aged 35-65 who were part of the Finnish Degenerative Meniscal Lesion Study (FIDELITY).

All patients had experienced pain in the inner side of their knee for at least 3 months, which clinical examination and magnetic resonance imaging (MRI) suggested was down to a torn meniscus.

Fast facts about meniscus tears
  • Among younger adults, particularly athletes, a torn meniscus is most commonly caused by a forceful rotation of the knee
  • Older adults are most likely to experience a torn meniscus as a result of knee degeneration
  • Symptoms may include a popping sensation, pain, swelling or stiffness, problems straightening the knee and knee locking.

Learn more about cartilage damage

The patients were free of knee osteoarthritis – a condition commonly associated with degenerative knee – and meniscus damage had not been caused by an isolated trauma.

Each patient’s torn meniscus was confirmed through diagnostic keyhole surgery. The patients were then randomized to receive either a partial meniscectomy or a sham treatment.

Prior to the surgery, 69 patients reported mechanical symptoms, of whom 32 (46%) were in the partial meniscectomy group and 37 (49%) were in the sham treatment group.

From a survey carried out 2, 6 and 12 months after the treatments, the researchers found that 34 (49%) patients in the partial meniscectomy group and 33 (43%) of those in the sham treatment group reported mechanical symptoms at some point during follow-up.

Of the 69 patients who reported mechanical symptoms before treatment, 23 (72%) patients in the partial meniscectomy group and 22 (59%) patients in the sham treatment group continued to experience such symptoms at certain times during follow-up.

Nine (28%) patients from the partial meniscectomy group and 15 (41%) patients from the sham treatment group reported complete alleviation of mechanical symptoms for the entire follow-up duration, according to the team.

Based on their findings, Prof. Järvinen concludes that “the partial removal of a degenerative torn meniscus does not reduce or alleviate mechanical symptoms when compared with sham surgery.”

Additionally, the researchers say their findings suggest that trauma-related meniscal tearing and degenerative meniscal tearing are two separate conditions and should be treated as such.

Dr. Sihvonen adds:

Research indicates that treatment of a torn meniscus, which is obviously traumatic in origin in a patient under 35 years of age, seems to alleviate mechanical symptoms.

In a degenerative knee, seemingly similar symptoms may not even be caused by the meniscal tear – more likely they are a reflection of the overall deterioration of the knee and prone to increase as arthritis develops further.”

Last November, Medical News Today reported on a study suggesting weight loss may slow knee degeneration for obese individuals.