Why can't I fully straighten my leg when walking eight months after anterior cruciate ligament surgery?

Anterior cruciate ligament (ACL) reconstruction surgery, commonly referred to as "anterior cruciate surgery," may result in difficulty straightening the leg when walking eight months after the procedure. Possible causes include knee arthritis, chronic synovitis of the knee joint, and hypertrophic scarring. Appropriate management should be based on the specific condition. Detailed analysis is as follows:

1. Knee Arthritis

After surgery, the knee joint is prone to inflammatory reactions such as pain and swelling. Continuous irritation of the injured joint can inhibit quadriceps muscle contraction, affecting normal walking and preventing full leg extension. It is recommended to use treatments such as acupuncture and massage. If necessary, these can be combined with infrared radiation therapy to promote quadriceps contraction and facilitate recovery of joint function.

2. Chronic Synovitis of the Knee Joint

If synovial tissue is damaged during surgery, it may trigger a chronic inflammatory response that restricts patellar mobility. Prolonged immobilization of the patella can impair leg extension. In such cases, patients may consult their physician about physical therapies such as ultrashort wave therapy or infrared polarized light treatment, along with appropriate exercises to improve knee joint mobility.

3. Hypertrophic Scarring

Although postoperative wounds may appear small, they can be deep and prone to forming scar tissue after surgery. If scar tissue becomes hypertrophic, it may occupy space in the anterior knee region and restrict knee joint movement. Treatments such as laser abrasion or microcrystal dermabrasion may be considered. Maintaining wound hygiene after treatment is essential.

In addition, conditions such as meniscal injury, lumbar disc herniation, or avascular necrosis of the femoral head may also contribute. Regular follow-up visits after surgery are recommended to monitor wound healing. Any abnormal symptoms should be promptly evaluated and treated at a hospital.