Knee injuries

A painful knee can be just a sign of too much stress on the knee, or the reason for the knee pain may also be an injury, which requires treatment. Read more about knee injuries from below and book an appointment in Mehiläinen with an orthopedist or a general practitioner to examine a painful knee.

Anterior cruciate ligament (ACL) and a tear in the ACL

The knee’s twisting injuries are very common sport injuries, in occasional workouts as well as in competitive sports. The ACL, a structure supporting the joint from the front to the back, is damaged during an injury unfortunately often. The ACL is also challengingly located in the middle of the joint. With current technology most of the tears in the ACL are able to be treated to be nearly in the same condition as before.

Surely one can live with a torn ACL, but even just a bit more intense sport activities, such as ball games, skiing or orienteering, cause discomfort to the knee when moving as well as symptoms of the knee failing under you. Also,an unstable joint degenerates faster than a healthy one; a need for an artificial joint may occur even ten years earlier than normally.

Treating tears in the ACL

Only just a few decades ago, the significance of the ACL was belittled and repairing it was not considered essential. Today, there is a fairly consistent view amongst the specialists doing knee surgeries about when an ACL needs to be repaired.

In Finland, over 2000 surgeries to repair the ACL are performed yearly. Mehiläinen is an expert in the field with almost 400 surgeries every year.

We have built a commonly accepted treatment standard for treating and rehabilitating ACL injuries, which surgeons and orthopedists are committed to. The treatment standard precisely defines the ways of procedure for the entire treatment chain from the diagnosis to the post-rehabilitation. By standardizing or ”productizing” we aim for constant quality in the treatment results and easing the monitoring of the results. At the same time, we are able to do scientific research.

The reason for tears in the ACL: falling down the most common reason

The diagnose of an ACL injury is usually done clinically, meaning at the doctor’s office without any specific further examinations. The accident is often a fall, in a way that, the knee bends inward or the knee aggressively over bends. Sometimes the strong over extending of the knee may cause a similar injury. The ACL’s ”fighting pair” the PCL, the posterior cruciate ligament has a distinctly stronger structure and therefore gets injured more rarely.

Patients, even game buddies, often tell about hearing a clear crack or a snap at the time of the injury. The tear usually bleeds a lot of blood into the joint of the knee. The knee swells up in a couple of hours and gets even more painful. At first, the pain isn’t always very strong, some even finish their match.

Examining and treating knee injuries

It’s important to remove the liquid from a swollen knee with a puncture. Finding a bloody puncture, indicates to an ACL damage, with a 40% probability on men. With women the probability may be even a little bit higher. Removing the liquid will also help with the pain.

Often already in the first clinical examination a clear looseness of the knee from front to back is revealed. Sometimes the pain at the start and the muscle tension prevent a reliable examination and the severity of the injury is only found out later. A regular X-ray examination is supposed to be done with every knee injury. However, the need for an MRI scan can be considered case by case. Ultrasounds or X-rays with a radio contrast agent of the knee are practically useless.

Now-days, there is no need for an emergency endoscopy of an injured knee, since the diagnosis can be determined for almost a certainty with easier methods.

On the other hand, for example the best time for a reconstruction of an ACL injury is just a few weeks after the injury. An acute blood knee and the related infection reaction has then already calmed down, so the surgery is technically easier. Also, the knee’s range of motion has time to recover back to normal and the patient can even walk pretty well.

Knee surgery

The repair of the ACL is now-days done with an endoscopy technique, meaning arthroscopy, almost every time. The ACL should not be stitched, since it won’t heal reliably, other than just on the youngest patients.

A torn ACL is instead removed and replaced with a tendon graft. In Mehiläinen, hamstring tendons from the thigh are used as the tendon grafts. Another common way is to take the graft from the kneecap’s tendon. The benefits of the hamstring graft are, that the surgery is technically easy and above all the patient won’t feel pain straight after the surgery. Therefore, most of the patients can already go home on the day of the surgery. For the end result, the graft material choice does not have a significance. The graft is attached to bone tunnels with small screws. The tunnels are aimed to be placed precisely at the attachment points of the torn ACL in the femur and tibia bones.

Recovering from a knee injury

The patients can start putting weight on the operated knee immediately after the surgery, according to the pain. Elbow stick are however used as support for a few weeks.

An athlete can often return to the same level they were at before the ACL repair, as examples there are several professional athletes and even olympic winners. However, the recovery process takes time, often the whole season. Jogging is allowed about three months after the surgery, faster running only a couple months later. Returning to sports requiring jumping and swift turns, such as racket sports, volleyball,orienteering etc. is allowed after about a half year after the surgery.

With the current technique, most of the torn ACLs are able to be treated, so, that they are almost the same condition as before. The treatment result however is not a 100%, because the ACL graft will be missing the original ACL’s ’sense of touch’. A real ACL has stretch sensors, which constantly send the nervous system information about the stress circumstances on the knee. An operated knee may feel a little bit strange or slow for the rest of one’s life, but it is supportive and painless. Unfortunately, an ACL graft is not any stronger than the original, so therefore, new tears may happen if the knee twists again. The risk is at its highest about half a year to one and a half years after the surgery when the knee already feels healthy and the athlete has excitedly returned to practicing. After a long break coordination and skills have however become weaker and the risk for a new injury therefore increases. That is why, it is important to have patience to rehabilitate the operated knee thoroughly and also give time for the rest of the body to recover from a long inactive period.

Meniscal injuries

Now-days, all meniscal injuries can be repaired with an endoscopic surgery. Small tears are repaired by removing the torn part of the menisci, saving the healthy parts. Only just about twenty years ago, before the endoscopic procedures became common, it was justified to remove the whole torn menisci by routine. It lead to a quickly developing wear and tear issue, so this process has been understandably abandoned.

Bigger meniscus tears especially with young patients are tried to repair either by stitching or more and more often by shooting so called meniscal darts in the tear. The darts are like small nails, which dissolve by themselves in about a year. The technique is however challenging, and it is not offered in all hospitals. Also, one needs to get to the repair fairly quickly, since if the menisci has been torn for a few months, often the tear isn’t suitable for the repair by the darts anymore.

Cartilage damage

A regional cartilage damage is a precursor of osteoarthritis. If a cavity or an unevenness forms on the sliding surface and the upholding area of cartilage with a twisting injury, it later on leads to the progress of the wear. Small cartilage damages in a way smooth themselves out, but bigger damages should be treated more actively. The state of the cartilage damage can be best found out with a cone beam computed tomography scan.

Jumper’s knee

Jumper's knee symptom is felt at the attachment area of the kneecap and the tendon either at the top, or normally at the bottom of the kneecap. A tissue damage is formed on the attachment of the bone and the tendon due to harsh pulls. In a way the tendon shreds and the damage area repairs its structure with bad scar tissue. If the strain doesn’t recur too often, the damage can fix itself, but with active athletes the problem often becomes chronic. With adolescent athletes a Sinding Larsen Johansson syndrome, which means incomplete ossification of the patella, meaning the bottom of the kneecap can be behind it. With older jumpers a predisposing factor can be the kneecap located unnecessarily high, so, the tendon under the knee cap is a bit unnecessarily long. This so said patella under - faulty position is most common with tall and skinny people, who are the typical jumpers.

The jumper’s knee issue is first treated with inflammatory medication and local cortisone injections. Cortisone cannot however be placed on the tendon tissue, because the tendon can perish and even break from this. Therefore,the injecting technique needs to be good. A big part of the jumper’s knee cases become chronic and won’t react to medication treatment. In these cases, a surgery where the tendon is split and the bad scar tissue is removed is considered. The tendon is then left to scar in peace and if the athlete has patience to not jump for 2 to 3 months, the problem will often be permanently gone.


Chondromalacia, softening of the kneecap’s cartilage is a bit of a vague disease, which is caused maybe partly due to a congenital tendency, partly due to small, reoccurring knee injuries, such as blows from the ”tiger jump” in volleyball. The cartilage in the kneecap usually breaks from a fairly small area and causes crunching and pain especially in the stairs (going down the stairs is usually more painful).Another typical problem caused by chondromalacia is a so called theater symptom, meaning pain and an uncomfortable feeling of pressure when needing to sit down for too long knees bent (in the movies, in the car, in the bus..). Chondromalacia is a benign disease,which calms down by itself with time. Dealing with the knee is easier when the thigh muscles are in good shape. Sometimes difficult symptoms can be eased with ”cleaning” the kneecap’s cartilage surface in an endoscopic surgery.

Osgood-Schlatter’s disease

Osgood-Schlatter’s disease is commonly behind the knee pain for an adolescent girl or a boy, who does a lot of sports. The pain is felt while running and jumping on the front of the knee just below the joint, meaning at the head of fibula.