The meniscus is a crescent-shaped piece of cartilage that acts as a shock absorber between the femur and tibia in the knee joint. When this tissue is torn, surgery is often performed to alleviate pain, remove mechanical blocks, and restore joint function. The timeline for safely bending the knee after this procedure is highly variable and depends almost entirely on the specific surgical technique used to address the tear.
How the Type of Surgery Dictates Bending Timelines
The most significant factor influencing the bending timeline is whether the surgeon performs a meniscectomy or a meniscus repair. A partial meniscectomy involves trimming away the torn, damaged portion of the cartilage, leaving the stable tissue intact. Since no tissue healing is required, bending the knee can often begin immediately or within the first few days following the operation, limited mainly by the patient’s pain and swelling. The goal after a meniscectomy is to achieve full range of motion as quickly as possible, often within the first two weeks, allowing for a rapid return to daily activities.
In contrast, a meniscus repair involves suturing the torn edges of the cartilage back together to encourage biological healing. This procedure requires strict limitation on knee movement to prevent tension from pulling the sutures apart and disrupting the healing process. For most meniscal repairs, the knee is restricted to a limited range of motion, typically between 0 and 90 degrees of flexion, for the first four to six weeks post-surgery. Bending the knee beyond 90 degrees places stress on the repair site, making this restriction necessary for long-term success.
Immediate Post-Operative Restrictions and Bracing
In the immediate post-operative period, safety measures are put in place to protect the knee regardless of the specific procedure. A hinged knee brace is commonly used, particularly after a meniscal repair, as a protective barrier against accidental over-bending or twisting. This brace is often locked in full extension (0 degrees of flexion) when the patient is walking or bearing weight, preventing movement that could compromise the repair. The brace settings may be adjusted to allow for a controlled, limited range of motion during non-weight-bearing exercises, such as the 90 degrees of flexion allowed for a repair.
The patient’s weight-bearing status is closely linked to the safety of bending the knee in the early stages. After a meniscal repair, patients are restricted to toe-touch or partial weight-bearing for several weeks, as loading the leg while the knee is bent increases stress across the repair site. Even after a meniscectomy, where bending is allowed, initial post-operative swelling and pain naturally limit the achievable range of motion. These physical restrictions and external devices are temporary tools designed to protect the healing joint until structured recovery begins.
Physical Therapy and Structured Range of Motion Progression
The transition from restricted movement to full, functional bending is a structured process overseen by a physical therapist. The therapist manages the progression, advancing range of motion goals based on specific criteria and the knee’s response to exercises, rather than following a rigid calendar timeline. For a meniscal repair, the therapist guides the knee past the initial 90-degree barrier, often progressing to 120 degrees or more after the four-to-six-week healing phase is complete. This progression ensures the newly healed tissue is not overloaded too soon, preventing re-injury.
The recovery program utilizes both passive and active range of motion exercises to regain full bending ability.
Passive Range of Motion
Passive range of motion is achieved through an external force, such as using the non-operative leg or a strap to assist the operated leg in bending (e.g., heel slides).
Active Range of Motion
Active range of motion, which follows later, involves the patient using their own muscles to bend the knee without assistance. A common milestone exercise is the use of a stationary bicycle, introduced once the knee can comfortably bend to at least 90 degrees. Patients must avoid pushing through any sharp, sudden pain, as this sensation warns that the joint is being stressed beyond its current healing capacity.