Cortisone injections are a common, non-surgical treatment for knee pain, particularly for conditions involving joint inflammation such as osteoarthritis and tendinitis. This procedure involves the injection of a corticosteroid combined with a local anesthetic directly into the joint space. The primary goal is to reduce swelling and irritation, thereby alleviating pain and improving joint function. However, the effectiveness of a cortisone shot is not guaranteed, and for many patients, the expected relief may not materialize or may fade quickly. When this initial, conservative measure does not succeed, it signals the need to re-evaluate the knee condition and explore alternative medical pathways.
Defining a Failed Cortisone Injection
When a cortisone shot is administered, the patient typically experiences a rapid, temporary reduction in pain due to the immediate action of the local anesthetic. This instant relief should not be confused with the long-term effect of the corticosteroid itself. The anti-inflammatory properties of the cortisone usually require time to become fully active, with noticeable improvement setting in within 48 hours to seven days. An injection is considered a failure if there is no measurable improvement in pain or function after this initial seven-day period. Alternatively, failure is defined by relief that is very short-lived, such as less than two months, when the expected duration is often between three and six months.
Potential Reasons the Shot Did Not Provide Relief
The lack of response to a cortisone injection indicates that the underlying pain source is either not primarily inflammatory or has progressed beyond the scope of this treatment. A common reason for failure is misdiagnosis, where the pain is mechanical rather than inflammatory, such as from a ligament tear. Corticosteroids reduce inflammation but do not address structural or biomechanical problems. The severity of existing joint damage is another factor, as advanced, bone-on-bone osteoarthritis may not benefit significantly, providing only minimal symptomatic relief. Technical precision also influences the outcome; if the medication is not accurately delivered, its effectiveness is compromised, and some patients may metabolize the drug rapidly or have reduced biological responsiveness.
Non-Surgical Treatment Pathways
Once a cortisone injection has failed, the focus shifts to non-surgical alternatives that address either the mechanical issues or provide a different form of biological support to the joint.
Physical Therapy and Bracing
Physical therapy (PT) is frequently the next step, involving targeted exercises to strengthen the muscles surrounding the knee, such as the quadriceps and hamstrings, to improve joint stability and function. A physical therapist can also identify and correct faulty movement patterns that contribute to pain. Additionally, the use of custom-fitted knee braces or other assistive devices can help to offload stress from the most damaged parts of the joint, providing external stability and supporting improved mobility during daily activities.
Injection Therapies
Another common non-surgical option is viscosupplementation, which involves injecting a gel-like substance called hyaluronic acid directly into the knee joint. This substance supplements the joint’s natural lubricant, reducing friction and improving shock absorption, particularly in patients with osteoarthritis. Regenerative medicine offers alternative injection therapies that aim to promote tissue healing:
- Platelet-Rich Plasma (PRP) therapy uses a concentrated solution of the patient’s own blood platelets, which contain growth factors that stimulate healing and reduce inflammation.
- Prolotherapy involves injecting a mild irritant solution, such as dextrose, to induce a localized, controlled inflammatory response that encourages the strengthening of weakened ligaments and tendons.
When Surgery Becomes the Next Step
For patients who have exhausted conservative non-surgical treatments without adequate pain relief or functional improvement, surgery is the final option. Criteria for surgical consultation include persistent, unrelenting pain that severely limits daily activities and advanced structural damage confirmed by imaging studies. Structural issues like significant cartilage loss, joint deformation, or ligament/meniscus tears require mechanical intervention. Surgical options vary based on the damage; arthroscopy addresses specific problems like meniscal tears, while a partial or total knee replacement (arthroplasty) is used for end-stage arthritis. This replacement procedure uses metal and plastic components, but a waiting period of three to six months is required after a final cortisone injection to mitigate the risk of post-operative infection.