Difficulty in bending and stretching after joint replacement surgery, why?

After knee replacement surgery, Mrs. Mai (55 years old, in Ho Chi Minh City) thought she would soon be able to walk again. However, 3 months later, her knee still had difficulty bending and stretching. The feeling of stiffness made every step difficult.

3 months after surgery, knee joint is difficult to bend and extend

Ms. Mai's case is not uncommon. Specialist Doctor Truong Cong Dung, member of the Executive Committee of the Ho Chi Minh City Musculoskeletal Endoscopy Association, Director of Sports Medic Clinic, said that knee replacement surgery is an important step forward in the field of orthopedic trauma, helping to reduce pain and restore motor function for patients with severe knee osteoarthritis. However, in some cases, even though the artificial joint still functions well, the patient may experience a stiff knee joint and limited flexion and extension.

The cause is often due to ankylosing spondylitis - a condition in which scar tissue grows excessively around or in the joint, causing the structures around the joint to stick together and hinder movement. "Simply put, instead of healing smoothly, the tissues around the joint 'contract' and 'stiffen', causing the joint to almost freeze and significantly reduce the range of motion," Dr. Dung explained. Some studies show that this complication occurs in about 3-10% of patients undergoing knee replacement surgery.

Joint fibrosis is often the result of a combination of factors - from the body's healing response, surgical technique, to the rehabilitation process. Some people are prone to fibrous tissue formation; others are afraid to move early due to pain and swelling, causing the joint capsule to contract. "Even if the joint replacement surgery is technically successful, if the patient does not receive proper rehabilitation, joint fibrosis can still occur," said Dr. Dung.

Surgeon operating on patient

Photo: BSCC

Flexion range below 80 degrees despite rehabilitation exercises

The most recent case is Ms. D.TKD (60 years old, in An Lac ward, Ho Chi Minh City). Ms. D. had her left knee replaced in February 2023 and her right knee in September 2024. After the right knee surgery, although the artificial joint worked well mechanically, due to the progressive fibrosis, her joint was almost completely stiff, with a flexion range of less than 80 degrees despite rehabilitation exercises (normally the knee joint can flex about 130-150 degrees). After examination, Dr. Dung decided to perform arthroscopic surgery to debride and release the patient's right knee.

The surgery went well. Ms. D. then underwent continuous physical therapy and rehabilitation for 2 months. Upon re-examination, her right knee was straight and flexed well, and she could walk and move normally.

Dr. Dung recommends that, to limit the risk of fibrosis after joint replacement surgery, patients need to start exercising early, practice the correct techniques under the guidance of doctors and physical therapists - rehabilitation technicians, and control pain and swelling well in the early stages. In addition, regular check-ups are also very important to detect early signs of limited mobility.

If after surgery, the joint cannot be fully extended or flexed, pain increases when moving or the range of motion is significantly reduced despite rehabilitation exercises, the patient should see a doctor soon. Because when fibrosis progresses without treatment, the artificial joint - although still mechanically good - can lose its motor function, making walking and daily activities as difficult as before surgery. Moreover, if the intervention is too late, arthroscopic surgery to remove adhesions will be less effective because the scar tissue thickens and becomes fibrotic, making it difficult to release the joint. According to recommendations, it should be performed within 3-6 months after joint replacement surgery to achieve optimal recovery results.

Source: https://thanhnien.vn/kho-gap-duoi-sau-phau-thuat-thay-khop-vi-sao-18525102717174277.htm