What is a meniscus?
The meniscal cartilages of the knee are C-shaped shaped structures that help reduce the pressure between the bones and also absorb shock during weight-bearing.
There are two meniscal cartilages in the knee:
The medial meniscus is on the inner aspect of the knee closest to the midline.
The lateral meniscus is on the outer aspect of the knee away from the midline.
Is a meniscus the same as a cartilage?
Yes the meniscus is one form of cartilage, known as fibrocartilage. This is made up primarily of type 1 collagen.
There are however other forms of cartilage too. In the knee the shiny cling film like cartilage lining all the bone surfaces is called hyaline cartilage, made up primarily of type 2 collagen.
The menisci should therefore be distinguished from the hyaline cartilage which is the clingfilm like shiny cartilage that lines and wraps the surfaces of the bones in order to reduce friction when the bones move against each other.
Meniscal tears: what is a meniscus tear?
A meniscus tear is a rip or breech in the normal collagen structure of the meniscus, which affects its normal function.
How do you tear a meniscus?
Meniscal tears can occur for two reasons:
significant Injury to the knee, which often involves twisting and impact and can be associated with injuries to other structures such as the cruciate ligaments.
A general weakening and thinning of the meniscus which can occur with with age or can be associated with chronic diseases such as diabetes or hypothyroidism. This weakening can then result in a small progressive tear to the meniscus which is not necessarily noticed at the time that it occurs.
In younger patients most meniscal tears involve significant injuries and are noticed at the time of injury.
How do I know if I have a meniscus tear?
The classic symptoms of meniscus tear are pain on twisting or deep kneeling
In the case of a single of injury, there may be a pain or pop at the time of injury. The knee can swell up either at the time of injury, or a few hours later.
There may be a period of recovery but then pain may occur when doing impact or twisting activities or deep kneeling.
Other symptoms can include:
Catching of the knee when doing strenuous activities such as twisting,
Locking of the knee which means that it freezes in one position and is difficult to fully straighten.
Persistent swelling.
Stiffness or reduction in straightening or bending of the knee.
How do you diagnose meniscus tears?
Most tears are diagnosed based on the patient’s story as well as the examination of the knee.
Do you need an MRI to diagnose a meniscus tear?
Although the story and examination may indicate meniscus tear, the most reliable way of confirming and diagnosing a tear is with an MRI scan.
Can you diagnose a meniscus tear on Xray?
No, Xray only shows bone and meniscus is a soft tissue made of collagen, not bone.
What are the different types of meniscus tear?
What is a longitudinal tear of the meniscus?
What is a radial tear of the meniscus?
What is a bucket handle tear of the meniscus?
What is a flap tear of the meniscus?
The different patterns of tear have different names and are shown in the diagram.
How do you treat a meniscus tear?
Treatment of meniscus tears ranges from:
Rest and physiotherapy and wait for the tear to scar up or heel.
Early surgery.
Late surgery for tears that are not healing or persistently symptomatic and painful.
Should I have surgery for my meniscus tear?
The decision to whether to operate early, do physiotherapy and which operation to perform depends on many factors:
Age, health and activity level of the patient.
How long symptoms have been present.
Whether physiotherapy has already been tried and failed.
The type of tear and whether it has moved out of position (displaced or dislocated or “bucket handle tear”).
Are there high risks of surgical complications? eg severe heart disease, history of blood clots, severe immune deficiency, severe chest disease or blood vessel disease in the leg.
If there is moderate or severe arthritis already in the knee. In these cases surgery for a meniscus tear is unlikely to help symptoms and may accelerate the progression of wear in the knee. So in most such cases surgery is not recommended unless there’s a significant loose bone in the knee.
At surgery, the meniscus tear is assessed for how healthy the meniscus is, the location of the tear and the pattern of the tear.
Are there guidelines for whether surgery will help with meniscus tear?
Yes the British Knee Society (BASK), has reviewed all the evidence to determine when surgery should be considered for meniscus tear. Mr Gupte is an executive member of BASK and was involved in devising these guidelines.
BASK British knee society meniscus tear guidelines. Full document can be accessed at https://static1.squarespace.com/static/611a3595eac3df3d2715f385/t/61717dedd0a7aa241aa94dda/1634827757425/BASK-Meniscal-Surgery-Guideline-2018.pdf
Which tears can be stitched back and which tears need trimming?
There are certain locations of tear which can be stitched back to together to in order to save the meniscus.
Otherwise the torn meniscus portion may require removal. The decision to stitch or trim the tear again depends on:
How long the tear has been present?
The location of the tear:
(Tears in the red zone, which have a good blood supply and are in a line are generally more likely to heal and therefore amenable to being stitched.)
The pattern of the tear and the state of the meniscal tissue at the time of surgery.
(For surgical treatment, Mr Gupte will use knee arthroscopy to either repair the meniscus or trim the torn portion if it cannot be repaired.)
The quality of the collagen tissue of the meniscus and tear.
The age and general health of the patient: tears are less likely to heal in smokers or where there is a very high load going through the knee after the operation eg in obesity.
Types of tears that can be stitched (in black) and those that may require trimming/removal (In red)
The decision to repair (stitch) or resect (trim) is a complex one
What is keyhole surgery for meniscus tear?
Is keyhole surgery the same as knee arthroscopy ?
Keyhole surgery, also known as arthroscopic surgery, is a minimally invasive procedure used to diagnose and treat issues within the knee joint, including tears in the meniscus. This surgery is performed under general anaesthesia, ensuring that our patients experience no discomfort during the procedure.
Does knee arthroscopy involve a general anaesthetic?
Yes. To begin, patients are placed under general anaesthesia, ensuring a pain-free experience throughout the surgery.
What are the stages of doing a knee arthroscopy?
Portal Placement
What does a meniscus repair look like?
Here is an instructional video that Mr Gupte made with his research team. This is a step-by-step guide on how to teach and perform meniscus repair of a bucket handle meniscus tear. A version of this video was published in one of the highest ranking sports medicine journals in 2020. Please only view if you are over 18 and not overly squeamish.
Small incisions, or portals, are made around the knee. Through these portals, our surgeons insert a camera and specialized instruments to view and repair the damaged meniscus.
Inspection of the whole of the inside of the knee including meniscus cartilages
A thorough inspection of the meniscus using the arthroscopic camera. This allows Mr Gupte to assess the extent of the tear and the condition of the surrounding knee structures.
Decision to trim or stitch the tear.
Based on the size, location of the tear, and the blood supply to the area, as well as the state of the meniscus collagen tissue, our team will decide on the best course of action. This could be either to trim the damaged tissue or to stitch the tear back into place.
When do you trim a meniscus tear?
If the tear is in a meniscus with poor collagen quality or in an area with poor blood supply or the tissue is significantly damaged, trimming the tear might be the best option.
When do you stitch a meniscus tear?
For tears located in areas with good blood supply or if the meniscus tissue is in a healthy state, stitching the tear may promote natural healing and recovery.
How long does knee arthroscopy take?
The duration of the keyhole surgery can vary depending on the complexity of the meniscus tear but typically takes between 15 to 45 minutes. Our goal is to perform a thorough and effective procedure in the shortest time possible, ensuring a quick recovery for our patients.
What does a knee arthroscopy scar look like?
Usually there are 2 (sometimes 3) scars, less than 4 mm in length.
What does knee arthroscopy recovery involve?
Post-surgery, patients will receive detailed aftercare instructions tailored to their specific procedure. Recovery times can vary, but our team is committed to supporting our patients every step of the way, from the initial consultation through to full recovery.
At our clinic, we are dedicated to employing the latest surgical techniques and providing the highest standard of care. Our team of experts is here to guide you through the decision-making process, ensuring that you receive the most appropriate treatment for your meniscus tear.