What Is Knee Osteoarthritis and Why Does It Keep Getting Worse Over Time?
The Joint Condition That Millions of Pakistanis Live With — Often Without Understanding It
Knee pain is one of the most common complaints among adults across Lahore and Pakistan. It affects people in their forties, fifties, and beyond, gradually limiting their ability to walk comfortably, climb stairs, sit cross-legged for prayer, or simply move through daily life without discomfort. Most people attribute it to age, excess weight, or years of physical work — and while these factors are relevant, they do not fully explain what is actually happening inside the joint or why the condition tends to worsen steadily over time despite rest and medication.
The most common underlying cause of this progressive knee pain is osteoarthritis — a degenerative joint condition that affects the cartilage, bone, and surrounding tissues of the knee. Understanding what osteoarthritis actually is, what happens inside the joint as it progresses, and why it follows the trajectory it does gives patients the knowledge they need to seek timely diagnosis and make informed decisions about their care.
At Alnoor Diagnostic Centre in Shadman, Lahore, we provide advanced musculoskeletal imaging that helps diagnose knee osteoarthritis accurately, assess its severity, and support the treatment decisions that can slow its progression and protect quality of life.
What Is Knee Osteoarthritis?
Osteoarthritis is a degenerative disease of the joints. In the knee, it primarily involves the progressive breakdown of articular cartilage — the smooth, firm tissue that covers the ends of the bones forming the knee joint. This cartilage acts as a shock absorber and allows the joint surfaces to glide against each other with minimal friction during every movement.
In a healthy knee, this cartilage is several millimetres thick, resilient, and continuously maintained by specialised cells called chondrocytes. In osteoarthritis, the balance between cartilage breakdown and repair is disrupted. The cartilage gradually loses its structure, becomes thinner and rougher, develops cracks and fissures, and eventually wears away in the most severely affected areas — exposing the underlying bone.
As cartilage is lost, the joint space between the femur and tibia — the thigh bone and shin bone — narrows visibly on X-ray. Bone begins rubbing on bone in advanced cases, causing severe pain, stiffness, and significant functional limitation. The entire joint — including the bone, synovial membrane, joint capsule, and surrounding ligaments — becomes involved as the disease progresses.
Why Does Knee Osteoarthritis Develop?
Osteoarthritis is not a single-cause disease. It develops when multiple factors combine to overwhelm the knee joint’s natural capacity for repair and adaptation.
Age is the most significant risk factor. Cartilage becomes less resilient with age, chondrocyte function declines, and the joint’s ability to heal microscopic damage decreases. This is why osteoarthritis becomes dramatically more prevalent after the age of 45 and affects the majority of people over 65 to some degree.
Excess body weight places disproportionate load on the knee joint. The knee bears approximately three to five times body weight during normal walking, and even greater forces during stair climbing and squatting. Every additional kilogram of body weight multiplies the mechanical stress on the cartilage significantly. This is why obesity is one of the strongest modifiable risk factors for knee osteoarthritis.
Previous joint injury — including ligament tears, meniscus damage, and fractures involving the knee — alters the mechanics of the joint and accelerates cartilage breakdown. Many patients who suffered a significant knee injury in their twenties or thirties develop osteoarthritis in the same knee decades later. Repeated occupational stress — years of heavy physical work, prolonged squatting, or kneeling — also accelerates wear.
Genetic factors influence cartilage quality and joint geometry. Some individuals inherit a predisposition to cartilage degeneration that makes them susceptible to osteoarthritis regardless of mechanical loading. Hormonal factors — particularly the decline in oestrogen after menopause — contribute to the significantly higher prevalence of knee osteoarthritis in women compared to men.
Why Does It Keep Getting Worse?
This is the aspect of osteoarthritis that patients find most frustrating. Unlike an infection that resolves with treatment or a fracture that heals, osteoarthritis tends to progress — slowly in some patients, more rapidly in others — despite rest, pain medication, and lifestyle modifications. Understanding the biological mechanisms behind this progression explains why early intervention matters so much.
Cartilage has no blood supply and extremely limited capacity for self-repair. When cartilage is damaged, the chondrocytes that maintain it cannot replicate adequately to restore lost tissue. Small areas of damage therefore persist and enlarge rather than healing. Over time, mechanical stress concentrates at the damaged areas, accelerating further breakdown in a self-perpetuating cycle.
As cartilage breaks down, fragments enter the joint fluid, triggering an inflammatory response in the synovial membrane — the lining of the joint. This inflammation causes swelling, warmth, and pain, but it also releases enzymes and inflammatory molecules that directly damage remaining cartilage. Inflammation that was initially a response to cartilage damage becomes itself a cause of further cartilage loss.
As the joint space narrows and the mechanical alignment of the knee changes, abnormal loading patterns develop. Areas of cartilage that were previously protected begin bearing loads they are not designed for, and they degenerate faster. The bone beneath the cartilage responds to altered loading by thickening and developing osteophytes — bony spurs at the joint margins. While osteophytes represent the body’s attempt to stabilise the joint by increasing surface area, they also restrict movement, cause pain, and contribute to further mechanical dysfunction.
The muscles around the knee — particularly the quadriceps — weaken as pain reduces activity. Reduced muscle support places even greater stress on the joint surfaces. Pain causes the patient to move less, which reduces both muscle strength and cartilage nutrition — because cartilage receives its nutrients through the compression and decompression of normal joint movement. Reduced activity therefore accelerates the very degeneration it is trying to avoid.
How Is Knee Osteoarthritis Diagnosed and Assessed?
Accurate diagnosis and proper staging of knee osteoarthritis is essential for appropriate management. At Alnoor Diagnostic Centre in Shadman, Lahore, we provide weight-bearing X-rays of the knee that show joint space narrowing, osteophyte formation, and bone changes — the standard imaging for osteoarthritis assessment. MRI provides detailed evaluation of cartilage thickness and quality, meniscal damage, bone marrow changes, and synovial inflammation in patients where more comprehensive assessment is clinically indicated.
Accurate imaging establishes the severity of the condition, identifies which compartments of the knee are most affected, and supports treatment planning — from physiotherapy and weight management in early stages to injections, bracing, and joint replacement surgery in advanced cases.