Tendons are dense, fibrous connective tissues that link muscle to bone, transmitting force to allow movement. When these tissues sustain an injury, often called a tear or rupture, the healing process is complex. A torn tendon can heal, but recovery depends heavily on the severity and location of the damage. Recovery is typically a lengthy process involving the generation of new tissue, which requires guided rehabilitation to regain strength and function.
The Biological Reality of Tendon Healing
Tendon tissue faces unique biological challenges during repair, which explains why healing is often slow. Tendons have low cellularity and poor vascularity, meaning they have fewer living cells and a limited blood supply compared to muscle or bone. This restricted blood flow slows the delivery of necessary nutrients and cells required to initiate the repair process.
The native tendon is primarily composed of highly organized Type I collagen fibers, which provide immense tensile strength. When a tear occurs, the body typically forms fibrovascular scar tissue rather than regenerating the original structure. This scar tissue is composed of a less organized mix of collagen, often including Type III collagen, which is mechanically inferior to the original Type I structure.
This process results in a healed tendon that is structurally weaker than the healthy tissue, increasing the risk of re-injury. The maturation and remodeling stage of the repair can last up to a year as the body attempts to organize the new collagen fibers under physical stress. While the resulting scar provides stability, it lacks the original tissue’s mechanical integrity, posing a challenge for full functional recovery.
Classifying the Injury: Partial Tears vs. Full Ruptures
Recovery is largely determined by the extent of the damage, classified as either a partial tear or a full rupture. A partial tear, often called a strain, involves damage to only a portion of the tendon’s fibers while tissue continuity remains intact. These injuries frequently respond well to conservative management because remaining healthy fibers can bear some load while the injured area heals.
Conversely, a full rupture means the tendon has been severed completely, resulting in a loss of continuity between the muscle and bone. The separated ends often retract due to the constant pull of the associated muscle, making it impossible for the tissue to naturally approximate and heal. Full ruptures, particularly in major tendons like the Achilles or rotator cuff, often necessitate surgical intervention to physically reconnect the torn ends.
The specific location of the tear also influences treatment decisions, even for partial injuries. A partial tear involving more than 50% of the tendon’s thickness may be considered for surgical repair, especially in active individuals. Partial tears that fail to improve after three to six months of non-operative treatment may also be escalated to surgery to prevent progression to a full rupture.
Non-Surgical and Surgical Treatment Pathways
Treatment for a torn tendon focuses on creating an optimal environment for the tissue to repair and remodel safely. Non-surgical management, typically the first line of defense for partial tears, begins with rest and immobilization using a brace or casting to protect the injury. Anti-inflammatory medications are used initially to manage pain and swelling, although their long-term effect on the biological healing process is debated.
The most important component of non-surgical recovery is a structured physical therapy (PT) program, which may begin after four to eight weeks. Therapy moves through phases, initially focusing on regaining range of motion and gradually introducing controlled stress to the healing tendon. Techniques like eccentric exercises, which lengthen the muscle while contracted, are used to promote better fiber alignment and increase the tendon’s load-bearing capacity.
For full ruptures, surgery is performed to re-attach the torn tendon ends to the bone or to each other, establishing initial stability. Following surgery, strict immobilization is required for four to six weeks to protect the repair site while healing begins. The post-operative phase transitions into a carefully controlled rehabilitation plan, where the physical therapist guides the patient through passive and then active exercises. The goal of this long-term rehabilitation, which can take six to twelve months, is to remodel the developing scar tissue into a robust structure through the progressive application of mechanical load.