One of the common risk factors for knee pain or injury is misalignment of the lower extremities, also known as “knock knees” or “bow legged.” This is most often due to congenital deformity, but can also be the result of injury. Although many people may have some degree of malalignment, many will not have any symptoms and can lead a life without knee pain.
Proper alignment is important for balance and normal function of the knee joint. In a properly aligned and balanced knee, the body’s weight is transferred through the center of the joint.
When there is misalignment of the knee joint, either from a congenital deformity, injury, or meniscus deficiency, this weight is distributed unequally to either the medial (inside) or lateral (outside) side of the knee. Over time, this can result in osteoarthritis, ligament injuries, meniscus tears, and cartilage or chondral defects.
The two conditions are known as varus and valgus.
- Varus (bow legged)- the majority of the body’s weight passes through the medial portion of the knee. This can put stress on the lateral collateral ligament (LCL). This can be worsen by overuse and obesity
- Valgus (knock knee)- the majority of the body’s weight passes through the lateral portion of the knee, putting stress on the medial collateral ligament (MCL).
Varus and Valgus conditions are usually visible when a patient is standing or walking. Lower extremity alignment is highly variable. Some experience no symptoms, while others may experience pain within or around the knee joint. If the misalignment is significant, other injuries such as ligament, meniscus, or cartilage injuries may occur causing pain, stiffness, or swelling.
Diagnosis is made based upon a thorough history and physical examination to determine the extent of knee malalignment. In most cases, full length standing X Rays are done to help determine the degree of varus or valgus. They are also helpful in determining appropriate treatment options. MRIs may be necessary to evaluate any soft tissue injury to the ligaments or cartilage of the knee joint.
Treatment is generally only necessary if you experience symptoms associated with knee malalignment or if the condition has resulted in a knee injury. Many cases can be treated with nonsurgical options such as activity modification, unloader bracing, physical therapy, and anti inflammatory medications.
Surgical treatment may be necessary if conservative treatment options fail or if an injury is associated with improper knee alignment. There are a number of surgical options that can address knee misalignment and associated injuries. These include unicompartmental or partial knee replacement, total knee replacement, and osteotomy. Often an osteotomy is combined with another procedure to treat the injury associated with the improper knee alignment.
An osteotomy involves making a small cut in the bone to allow the alignment to be corrected. Once the alignment is corrected, screws are placed to hold the proper alignment and allow for healing.
Surgical options for treating knee malalignment will depend on the patient’s age, activity level, and any other underlying conditions such as osteoarthritis. If surgery is recommended you and your physician will decide the most appropriate treatment option based on these factors.