What is arthroscopy?

Arthroscopy is a surgical technique that allows orthopedic surgeons to diagnose and treat different disorders that may occur in a body joint (knee, shoulder, ankle,…). The joint is accessed through small incisions in the skin, and using an instrument the size of a pencil called an arthroscope, which gives us a clear view of the interior of these joints.

This arthroscope contains optical fibers that transmit the image to a small camera, which is connected to a TV monitor. The image in this monitor allows the surgeon to examine in detail the inside of the joint currently being worked on, and determine, in most cases, the source of the problem. During this procedure the surgeon can also insert, through one or more incisions, other instruments within the joint, to therefore treat the pathology. Consequently, arthroscopy is a technique that, as well as allowing the diagnosis, also allows the treatment of joint problems.

Compared to traditional open surgery, which involves a larger incision in the skin, the surgical technique of arthroscopy is less painful, involves less risk of infection, and allows patients to recover more quickly.

Modern arthroscopy began in the early 1960s, and the knee was the first joint where an arthroscopy was performed.

With the technological improvements in arthroscopes and with the arrival of high-resolution cameras, procedures have become increasingly more effective, so today arthroscopy is one of the most common surgical procedures in orthopedic surgery.


The knee is a joint formed by three bones: the bottom of the femur, the top of the tibia and the patella. The articular surfaces of these bones are covered by a layer of tissue softer than bone, but with a marbling appearance, called CARTILAGE, over which these surfaces slide to give the flexion and extension movements of the knee (the bend and stretch movements).

To match the articular surfaces of the femur (spherical surface) and tibia (flat surface) there are two MENISCI: the medial meniscus and lateral meniscus.

To stabilize the knee joint there are four LIGAMENTS:

  • 2 collateral: medial and lateral, located on both sides of the knee.
  • 2 cruciate: anterior and posterior, located in the centre of the knee.

Preparation for an Arthroscopy

Before the intervention, the surgeon and/or anesthetist will have reviewed the pre-operative tests (blood test, chest X-ray and EKG) to rule out any alteration that leads to an added risk to the anesthetic and surgical procedure.
The patient should fast (no food or drink) for about 6 hours before surgery, and he or she will be admitted to the hospital 2-3 hours before surgery.

The Arthroscopy

In knee arthroscopies, the type of anesthesia used most often is spinal anesthesia (injection into the lower back), which allows the legs to be asleep during the procedure, while the patient remains awake. If you wish, you can follow the procedure on the TV monitor, while the surgeon explains everything that he or she is doing in that precise moment.

Through a small initial incision, we insert a cannula into the joint, and fill this with serum. Through a small second incision, we insert the device called an arthroscope, and began the visualization of the joint.

The Knee Pathologies that can be treated by Arthroscopy are:

1- Menisci Tear: The menisci are structures of cartilaginous consistency, they are two in number, and they are located between the tibia and the femur on both sides of the knee. The menisci are crescent-shaped, and the most frequent location of the tear is at its posterior part. When there is a tear, the joint stops working properly due to the broken meniscus fragment, so by means of arthroscopy and with appropriate instruments, this fragment is cut, leaving the rest of the healthy meniscus in place.
Sometimes the meniscal tear is very close to its insertion zone, so in these cases we perform a repair of the injury, using a suture technique.

2- Cruciate Ligament Tears: By far the most common tear is the anterior cruciate ligament tear. This occurs with a movement in which the foot remains fixed and the body rotates on the axis of the knee. This movement is very common in sports like skiing, soccer and basketball.

A tear of the anterior cruciate ligament means that the knee starts to present symptoms of instability, i.e. an abnormal, spontaneous movement that the patient notices as problematic. Once it is broken, the anterior cruciate ligament is not capable of self-repair (healing), so if the injury is not repaired, this abnormal movement ends up affecting the meniscus (which eventually breaks). Later it affects the cartilage, which starts a process of degeneration, at which point the lesions are no longer repairable.

Therefore, today it is widely proven that to avoid the onset of this degenerative process, anterior cruciate ligament injuries must be repaired. It should be replaced by a structure that is in the same position and fulfills the same function as the injured anterior cruciate ligament. That is why the so-called PLASTIES are used. Basically we get them from the patient itself, and mainly from 2 locations: the patellar tendon in the knee (Bone-Tendon-Bone type plasty) or the tendons of the semitendinosus and internal rectus muscle (Hamstring type plasty), located at the back of the thigh. The use of either plasty depends on the surgeon’s preference and the demands of the patient (e.g. the sport the patient plays).

The plasty is placed through an arthroscopy in the same anatomical position of the original anterior cruciate ligament, and is attached at the femur and tibia level with so-called fastening systems, which are different depending on the type of plasty used. These fastening systems are positioned inside the bone, and will not have to be removed later, as they will not cause any discomfort.

The tear of the posterior cruciate ligament is much better tolerated with a correct pattern of recovery (there is usually no feeling of problems by the patient). We will only choose surgical treatment if there is the presence of problems, and the same procedure to that of the anterior cruciate ligament will be performed: replacement of the original ligament for a plasty.

3- Presence Of Articular Loose Bodies: They come from cartilage, and their presence may be due to trauma (osteochondral fracture) or degenerative processes.

4- Certain types of Fractures: In fractures of the tibial surfaces we can make use of arthroscopy to put in place the fracture fragments, and secure them with osteosynthesis screws.

The RISKS of Knee Arthroscopy are:

  • Anesthetic Risks: There may be allergic reactions to drugs used during anesthesia, respiratory problems, and cardiovascular problems. To avoid much of this type of complication some preoperative tests are requested before the intervention (as discussed above).
  • Circulatory Problems: phlebitis, thrombosis. To avoid this, a few days after the arthroscopy subcutaneous medication is administered (heparin of low molecular weight), which has the effect of clarifying the blood to a small degree, so the risk of suffering this kind of complications greatly decreases, but does not disappear completely.
  • Presence of Joint Stiffness: After the arthroscopy, the knee can react causing the swelling and hardening of internal tissues which rapidly decrease joint mobility. With current techniques the mobility of the knee is almost immediate after the procedure, which means that the presence of joint stiffness is increasingly rare.
  • Joint Infection: Incidence of infection is less common than in open surgery. It appears 7-10 days after surgery, and requires surgical cleaning in the knee combined with an intravenous antibiotic treatment.
  • No complete disappearance of symptoms, especially in arthroscopies performed in degenerative knees i.e. that have signs of wear.


For less complex surgeries (meniscal tears, cartilage pathologies) we begin the mobilization of the knee 6 hours after surgery, and the patient can start walking (without any restraint, only a simple bandage to protect wounds), although in some cases it may require the help of a crutch to reduce pain. The patient is discharged from hospital in the first 24 hours after surgery, and can start an almost normal life a few days later (except to practice any sport; for that the patient must wait 2 to 4 weeks depending on the type of pathology).

In more complex procedures (cruciate ligament tear) it is not until 36-48 hours after the procedure that we start to flex and extend the knee, and 2 days after the operation the patient is discharged from the hospital on foot, aided by two crutches and supporting the operated leg on the floor, but without ANY KIND OF IMMOBILIZATION on the knee. At 4 weeks the patient already walks normally (without crutches), fully flexing and extending the knee, and 3 months after the surgery the pattern of recovery ends and the patient can start certain sports (continuous running, cycling and swimming). It is not until 6 months after the surgery that the patient will be able to practice any sport (soccer, basketball, skiing, tennis…).


The concept is the same as we have explained for knee arthroscopy: it involves inserting the arthroscope in the shoulder joint, so we can visualize its interior through a TV monitor, making possible the diagnosis and treatment of different pathologies.

In the shoulder joint we can perform an arthroscopy in two locations:

  • Glenohumeral: It is exactly the joint where the shoulder movement is performed.
  • Sub acromial: It is a space that is immediately above the glenohumeral joint, and through which the tendons pass allowing the raising of the arm.

Preparation for the intervention is the same as for knee arthroscopy: application and review of preoperative tests, fasting for 6 hours before surgery, and admission to hospital 2-3 hours before surgery.


General anesthesia is usually used, reinforced with a type of regional anesthesia called interscalene block: the anaesthetist, prior to the general anesthetic, numbs the shoulder area, and this anesthesia lasts for 12-18 hours, so that after the surgery the patient has less pain. In patients in whom general anesthesia is contraindicated, only this type of regional anesthesia may be executed, but it requires a very high level of cooperation from the patient during surgery.

The pathologies that can be treated with arthroscopy are divided by anatomical location where the arthroscopy is performed:


  • Recurrent Shoulder Dislocation: When the joint is dislocated multiple times, the ligaments that normally hold the joint in place are detached from the place where they are attached to the bone (glenoid): this is called a Bankart lesion. What we do is reattach these ligaments to their original place, using two or three implants (material which sets these ligaments, and that remains inserted into the bone).

    The fact that the ligaments that hold the shoulder’s stability go back to their anatomical location restores the original stability to that articulation.

  • Biceps Tendon Pathology: Of the two proximal tendons of the bicep muscle of the arm, there is one that has its origin in the interior of the glenohumeral joint, and when there is an injury at this level is called a SLAP lesion. The repair of this lesion can also be done arthroscopically.
  • Articular Loose Bodies: These usually originate in degenerative joint diseases, where fragments of cartilage in the joint detach themselves.
  • Joint Stiffness: The shoulder is a joint where, when faced with certain injuries, after an intervention or without any apparent reason (idiopathic), the tissue that covers the joint experiences a process of inflammation and shrinks: this is called retractable capsulitis. This means that a major limitation of shoulder mobility progressively appears, accompanied in the early stages by intense pain. At first the treatment is medical with rehabilitation and the possibility of adding an arrangement of infiltrations. But in more advanced stages, where the previous treatments had not been effective, shoulder arthroscopy is performed, and the shrunken tissue is cut, returning mobility to the joint.


  • Pathology of the Tendons of the Rotator Cuff (also called Rotator Cuff): This is the name given to the anatomical structure forming three tendons (supraspinatus tendon, infraspinatus tendon and subscapularis tendon) at shoulder level, immediately above the humeral head, which is where they are attached. These tendons are responsible, together with the deltoid muscle, for most shoulder movements, for example movements to lift and rotate the arm.

    These tendons may suffer different pathologies:
    1- An inflammatory process: We talk about tendinitis, which can be caused by acute trauma, or by a process of repeating movements in a shoulder where a compression phenomenon of the acromion bone over these tendons occurs. This process is called “impingement”.
    The initial treatment of this pathology is conservative: medical treatment with anti-inflammatories, a rehabilitation routine and an arrangement of infiltrations. If all these measures have failed, then we evaluate performing shoulder arthroscopy, to resect the inflammatory tissue surrounding the tendons, and in the case of encountering a phenomenon of “impingement”, perform a resection of the bone spicules to thus increase the space for the passage of the tendon.

    2- Tendon Tear: The location of the break is in the great majority of cases where the tendon is inserted to the humerus bone. These breaks may be small (1-2 cm) and recent, or large (4 cm or more), of long evolution or chronic.
    To repair such tears an implant is inserted in the original zone of the tendon insertion; this implant has some sutures through which we will close the rupture.
    It is important to note that the prognosis for the reparation of large tears (chronic) is worse than that of the small tears, since the torn tendon and the muscles responsible for its action will eventually degenerate. This will produce a retraction and scarring phenomenon, a fact which means that, if we repair the tendon again, this has little chance of healing.

  • Tendon Calcifications: There are cases when calcifications appear within the tendons, mostly within the supraspinatus tendon. These calcifications lead to a process of irritation of the affected tendon, causing significant pain, manifesting clinically as tendinitis. With shoulder arthroscopy the contents of intratendinous calcium can be emptied, thus removing of the pain.
  • Involvement of the Acromioclavicular Joint: This is the joint formed by the clavicle and part of the scapula called the acromion. This joint has a small movement, and if it is affected, for example by an inflammatory or degenerative process, causes significant pain. With shoulder arthroscopy we can act on this joint, partially resecting it, thus eliminating the symptoms.

The RISKS of Shoulder Arthroscopy are:

  • Anesthetic Risks: There may be allergic reactions to drugs used during anesthesia, respiratory problems, and cardiovascular problems. To avoid much of this type of complication some preoperative tests are requested before the intervention (as discussed above).
  • Joint Stiffness: This can range from a minimum degree of limitation of the last degrees of mobility of the shoulder to symptoms of true articular stiffness.
  • Joint Infection: Although the risk is very low, when the action protocol is presented, it is the same as in the case of the knee: surgical cleaning of the joint combined with an intravenous antibiotic treatment.
  • Recurrence of Treated Pathologies: For example, the shoulder treated for relapsing dislocation can re-dislocate (by other trauma), or the supraspinatus tendon that has been sutured can be broken again.


The period spent in the hospital after surgery is usually 24 hours. In the articular pathologies and in small and medium sized tendon tears, the arm is immobilized with a simple sling. By contrast, in large breaks of the rotator cuff, an immobilization that separates the arm from the body at 15º is put in place, in order to leave slack in the suture and reduce the risk of re-breaking.

In all cases, a few days after the operation the pattern of passive mobilization of the shoulder begins: this is moving the arm without any force on the tendons. This can be done with so-called pendulum exercises, and helping to move the affected arm with the contralateral arm, this being the one making the effort.

In cases of treatment of recurrent dislocation and those of tendinitis, at 4 weeks after surgery the affected arm starts the pattern of active mobility: force movements are initiated. In tendon sutures, these movements are not performed until 6-8 weeks after surgery.

After 3 months, patients begin their normal activities, except in cases of tendon suture, where the period is extended to about 4-5 months. It will be from the sixth month onwards that patients can practice any kind of sport, such as contact sports.