With rising cases of knee osteoarthritis, there is a need for awareness and education to understand the underlying causes, management and treatment options for patients. Dr. Ashwani Maichand, a renowned orthopaedic surgeon in India explains how knee osteoarthritis often begins in the medial compartment.
Knee osteoarthritis often begins on the inner side of the knee, known as the medial compartment. Dr. Ashwani Maichand elaborates that this is not coincidental but a result of how the human body carries weight and maintains balance.
“In most individuals with knee osteoarthritis, we see that the medial compartment has little to no joint space left, while the lateral compartment still shows preserved space,” says Dr. Maichand. “This asymmetry tells us exactly where the damage starts and why.”
Why the Medial Compartment Gets Impacted
Pain and arthritis impacting the medial compartment is far more common because this is the area of the body that bears more weight disproportionately compared to the lateral compartments. This is because the human body’s center of gravity passes through the medial compartment of the knee. As a result, a significant portion of body weight is transmitted through this area during standing, walking, and everyday movement. Over time, this constant load accelerates cartilage wear in the medial compartment. Adding to this stress is muscle imbalance, particularly involving the hamstrings.
“The hamstrings play a crucial role in controlling knee movement,” Dr. Maichand explains. “When the hamstrings become tight, they alter pelvic alignment, leading to a pelvic tilt. This shifts forces even further into the medial compartment, causing full compression where the joint is already vulnerable.”
Importance of Compression and Joint Space
In healthy knees, joint space allows cartilage to cushion movement. In osteoarthritis, the medial compartment often loses this protective space entirely. With every step, bone-on-bone compression occurs, intensifying pain, stiffness, and progressive damage, while the lateral compartment may remain relatively unaffected.
Integrity of the ACL
Dr. Maichand emphasizes that treatment decisions hinge on one crucial factor: the integrity of the anterior cruciate ligament (ACL).
“If the ACL is intact, cartilage restoration or joint-preserving procedures may be possible,” he says. “However, if the ACL is compromised, joint replacement becomes the more reliable option.”
This distinction is key for patients seeking to delay or avoid knee replacement surgery. Early diagnosis, proper imaging, and biomechanical assessment can help determine whether the knee can still be saved.
A Call for Early Intervention
Dr. Maichand stresses that understanding why osteoarthritis starts in the medial compartment empowers patients to seek timely treatment. “Knee osteoarthritis doesn’t happen overnight,” he notes. “When addressed early before complete joint collapse, we have more options to preserve the natural knee.”
Understanding why osteoarthritis targets the medial compartment first allows clinicians to intervene earlier, through alignment correction, muscle balancing, and joint-preserving strategies, before irreversible damage sets in.
