To Scope or Not to Scope the Knee

author : AMSSM

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Should you get arthroscopic surgery? Here are several knee problems that arthroscopy can help diagnose and even fix.

By George Pujalte, MD, CAQSM
Member AMSSM

Arthroscopy (or a scope) is a surgical procedure that involves the use of an arthroscope (a tube-like instrument utilizing fiber optics) to diagnose an injury to or disease of a joint or to perform minor surgery on a joint.  When considering the knee specifically, pain can be caused from a variety of problems:

1. a condition within the knee joint itself, such as a meniscal or ligamentous injury or a fracture
2. malalignment or problems with the kneecap
3. loss of, or problems with the cartilage, such as in osteoarthritis
4. inflammation of bursae around the knee
5. tendon problems
6. referred pain from the hip, femur, or spine
7. inflammation of the lining of the knee, such as in synovitis. 

Before the Decision to get Arthroscopic Surgery

In order to identify the cause of knee pain, a sports physician will review the history of the painful knee and determine its origin, duration, and any association with trauma or specific activities. The decision to refer any athlete to an orthopedic surgeon for possible arthroscopy depends on such an evaluation of the patient, and the determination as to whether or not arthroscopy will actually lead to an outcome beneficial to the patient. Furthermore, this decision often is made after treating with conservative measures, such as relative rest, use of modalities, bracing, physical therapy, or NSAID use.

Accuracy of an Arthroscopic Diagnosis

Arthroscopy is the most accurate method of diagnosing the cause of any problem within the knee joint itself. False-positive and false-negative results are rare, which means that it is very difficult to see something that is not there, or not see something that is actually there. This is true except in cases of posterior meniscal tears. Arthroscopy may also be used selectively as a way to support a diagnosis after history and physical examination, or when MRI findings lead to more uncertainty.

What Injuries Benefit from Arthroscopic Surgery?

Patients with unstable cartilage flap tears, meniscal tears, or loose bodies with mechanical symptoms (locking, catching, or giving way) may benefit from procedures done with arthroscopy.   Ligament reconstructions are commonly performed through an arthroscope.  Patients with isolated or multiple cartilage defects may be candidates for cartilage-preserving or restoring techniques, the details of which should be discussed thoroughly with the orthopedic surgeons who will be performing them, as techniques and evidence regarding these arthroscopic procedures are constantly evolving.

Arthroscopic Irrigation

In addition, there are studies that support arthroscopic irrigation in patients with inflammatory symptoms, whose knee pain did not respond to NSAIDs or steroid injections into the knee. These patients may have debris and crystalline material that are removed with irrigation, leading to improved symptoms and function. However, some recent studies suggest the possibility that the benefit of such procedures is due more to a powerful placebo effect of a surgical intervention rather than to any actual effects on the joint.

Immediately Get Scoped If...

The only absolute reason that a patient should be referred for arthroscopy is mechanical disruption of normal knee function, such as a meniscal flap or loose body preventing full knee extension. Referral in these cases should be made as soon as possible after presentation in the clinic to prevent stiffening of the joint.

When not to get Scoped

However, not all patients with knee problems will benefit from an arthroscopy.  A procedure called “lavage and debridement,” for osteoarthritis is controversial.   A study of 180 patients with knee osteoarthritis who were randomly assigned to procedures performed with arthroscopy (debridement and lavage) revealed no improvement in pain or function when compared to a placebo group in which sham incisions were made.

In summary, to scope or not to scope a painful knee would depend first and foremost on the diagnosis reached after a thorough history and physical examination. Upon reaching a diagnosis, usually conservative measures are first employed before a referral for arthroscopy is even considered.  The only exception would be mechanical disruption of normal knee function, in which case such a referral should be considered earlier. 

Bentley G, Minas T. Treating joint damage in young people. BMJ 2000; 320:1585.

Bomberg BC. Acute hemarthrosis of the knee: indications for diagnostic arthroscopy. Arthroscopy 1990; 6:221.

Boyd KT, Myers PT. Meniscus preservation; rationale, repair techniques and results. Knee 2003; 10:1.

Minas T, Nehrer S. Current concepts in the treatment of articular cartilage defects. Orthopedics 1997; 20:525.

Moseley JB, O'Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002; 347:81.

Vahasarja V, Kinnuen P, Serlo W. Arthroscopy of the acute traumatic knee in children. Prospective study of 138 cases. Acta Orthop Scand 1993; 64:580.

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date: December 12, 2009