Hinged Knee Replacement

When knee discomfort becomes severe and begins to disrupt your daily activities, or if it’s accompanied by swelling, tenderness, or redness, it’s crucial to seek medical attention.

At Complete Orthopedics, our team of specialized orthopedic knee physicians focuses on treating knee pain, offering both non-surgical and surgical solutions. We’re here to evaluate your symptoms, diagnose the issue, and recommend the most suitable treatment plan, including surgical intervention if necessary.

With locations in New York City and Long Island, and privileges in six hospitals, we’re fully equipped to deliver advanced knee surgery and comprehensive orthopedic care. To schedule an appointment with one of our orthopedic surgeons, you can conveniently book online or contact us by phone today.

Explore the common causes and treatment options for knee pain, and discover when surgical intervention becomes the optimal choice.


Imagine the intricate machinery of your knee joint—ligaments, cartilage, bones—working seamlessly to allow you to walk, run, and move freely. But what happens when this intricate system breaks down due to injury, arthritis, or other medical conditions? This is where knee replacement surgery comes into play, offering hope for improved mobility and quality of life.

One type of knee replacement surgery, known as hinged knee replacement, is designed to address more complex knee issues. In this guide, we’ll delve into the basics of hinged knee replacement surgery, exploring what it involves, who it’s for, its benefits, and potential risks.



A person who might need a hinged knee replacement typically experiences significant knee pain and mobility issues due to severe knee arthritis, injury, or other conditions affecting the knee joint. Here are some symptoms that may indicate the need for a hinged knee replacement:

Chronic Knee Pain: Persistent and severe knee pain, especially during weight-bearing activities such as walking, climbing stairs, or standing for long periods.

Decreased Range of Motion: Difficulty in fully extending or bending the knee joint, resulting in limited movement and flexibility.

Swelling and Inflammation: Swelling around the knee joint that doesn’t improve with rest, ice, or elevation. Chronic inflammation can indicate underlying joint damage.

Stiffness: Feeling stiffness in the knee joint, especially after prolonged periods of inactivity, such as sitting or sleeping.

Instability: Sensation of the knee giving way or feeling unstable during movement, which can increase the risk of falls.

Difficulty Walking: Persistent difficulty walking due to pain and limited mobility, which may require the use of assistive devices like canes or walkers.

Pain at Rest: Experience of knee pain even while at rest, which can disrupt sleep and daily activities.

Previous Failed Treatments: Inadequate relief from conservative treatments such as physical therapy, medications, corticosteroid injections, or arthroscopic surgery.

X-ray Findings: Radiographic evidence of advanced joint degeneration, bone-on-bone contact, or other structural abnormalities in the knee joint.

Functional Impairment: Significant impairment in performing activities of daily living, recreational activities, or work-related tasks due to knee pain and limitations in movement.


Hinged Knee Replacement

The implants used in a total knee replacement come in different shapes and sizes. The choice of implant used in a total knee replacement depends upon the amount of the bone, quality of the bone, the soft tissue around the knee, any prior surgeries, and also on the medical history of the patient. A hinged knee replacement is a complex knee replacement that requires a special implant with either a hinge or a rotating platform.

During a knee replacement surgery, the surgeon removed the diseased ends of the lower end of the thigh bone and the upper part of the shin bone. The prosthetic replacement of the removed parts recreates the natural knee joint without any disease.

The prosthetic parts are made of metal and high-grade plastic. The femoral and the tibial component are made up of metal while the insert or the spacer is made up of high-grade plastic. The plastic spacer helps in the smooth gliding of the opposing metal surfaces.

Revision knee replacement showing use of semi-constrained components.

Revision knee replacement showing use of semi-constrained components.

A natural knee has motion in the forward and the backward direction as well as a small amount of rotation and side-to-side motion. The thigh bone also slides back on the upper part of the shin bone during bending of the knee which is known as femoral rollback.

Constrain is the ability of the implant to provide stability in forward-backward and side-to-side motion. The constrained implants are needed in the face of bone loss or labor of the ligaments. Implants may be non-constrained, semi-constrained, or fully constrained depending upon the amount of stability they provide.


During a primary knee replacement for arthritis, only the bony ends are diseased and may be associated with mild to moderate deformity. The surgeon removes only the diseased ends and may stretch or release ligaments to correct the deformity.

The bone quantity and the soft tissue support is however adequate to provide stability to the prosthetic joint. Therefore the commonly used knee replacement implants in primary surgery are non-constrained.

Intraoperative image showing modular knee replacement implants.

Intraoperative image showing modular knee replacement implants.

All prosthetic implants are limited by their self-life as they wear down over the years. The life of a usual knee implant may be well over more than 20 years and for patients over 60 years of age, they may last their lifetime.

Owing to the success of the surgery, knee replacement is increasingly being performed in the younger age groups. In younger age groups after many years, the implants may need revision surgery. Additionally, revision surgery may be needed in patients with complications of primary surgery such as infection, aseptic loosening, fracture, instability, etc.

During revision surgery, at times there may be an excessive bone loss that may warrant a modular constrained implant. Similarly, in patients with excessive ligament laxity, a constrained implant may be necessary to provide stability. Patients suffering from some kinds of tumors of the bone may require removal of the stabilizing structures of the joint along with the bone tumor. These patients may also require constrained implants.

The constrained implants come in different designs. The originally used hinged constrained implant has been largely superseded by a rotating constrained implant. In a hinged knee replacement implant, there is a connecting rod in between the femoral and tibial components.

The connecting rod has a hinge mechanism to prevent overextension of the joint. This design only allows forward and backward motion and prevents any side to side and rotating motion.

The loss of side to side and rotating motion puts additional stress at the bone-implant interface and may lead to implant loosening or periprosthetic fracture. The rotating constrained implant additionally allows rotating motion about the prosthetic hinge. The hinge is located near the femoral component and a rotating platform is attached to the tibial plate.

The rotating action helps to distribute the stresses more evenly during motion while maintaining stability in the face of bone loss or ligament laxity. The hinged implants are primarily used in revision surgeries and in complex primary knee replacement surgery involving severe deformity or tumors, or salvage surgeries, etc.

The hinged knee replacement implants are also modular that allows the addition of metal wedges or triangles to compensate for bone loss. The stem modularity also allows the addition of long stems to provide stability.

The constrained implants wear out earlier compared to non-constrained but provide excellent stability in difficult cases. The results of constrained hinged knee replacement are better when performed by a surgeon with expertise in performing complex knee replacement surgeries.


Recovery and Rehabilitation:

Recovery from hinged knee replacement surgery typically involves a period of rehabilitation to help restore strength, flexibility, and function to the knee. Physical therapy exercises, pain management strategies, and assistive devices such as walkers or crutches may be recommended to aid in recovery.

It’s essential to follow your surgeon’s instructions carefully during the recovery process to ensure the best possible outcome. This may include attending follow-up appointments, adhering to activity restrictions, and practicing proper wound care.



Hinged knee replacement surgery is a valuable option for individuals with complex knee problems that cannot be effectively treated with conservative measures or traditional knee replacement surgery. By incorporating a specialized hinge mechanism, this procedure offers enhanced stability, improved range of motion, and pain relief for eligible candidates.

If you’re experiencing significant knee pain, stiffness, or instability, it’s essential to consult with a qualified orthopedic surgeon to explore your treatment options. With advances in surgical techniques and implant technology, hinged knee replacement offers hope for improved mobility and quality of life for those in need.



Do you have more questions? 

How long does hinged knee replacement surgery typically take?

Hinged knee replacement surgery usually takes around two to three hours, depending on the complexity of the case and any additional procedures required.

What type of anesthesia is used for hinged knee replacement surgery?

Most hinged knee replacement surgeries are performed under general anesthesia, although regional anesthesia such as a spinal or epidural may also be used in some cases.

How soon after surgery can I expect to be able to walk?

Patients typically begin walking with the assistance of a physical therapist and a walker or crutches within the first day or two after surgery. Full weight-bearing may take several weeks to achieve.

Are there any dietary restrictions following hinged knee replacement surgery?

While there are no specific dietary restrictions, maintaining a balanced diet rich in nutrients can support the healing process and overall recovery.

What activities should I avoid after hinged knee replacement surgery?

Initially, you should avoid high-impact activities such as running or jumping. Your surgeon will provide guidance on gradually reintroducing activities based on your individual progress.

How long does it take to fully recover from hinged knee replacement surgery?

Recovery time can vary depending on factors such as age, overall health, and adherence to rehabilitation protocols. Most patients experience significant improvement within three to six months post-surgery, with continued gains over the following year.

Will I need physical therapy after hinged knee replacement surgery?

Yes, physical therapy is an essential component of recovery after hinged knee replacement surgery. It helps improve strength, flexibility, and function in the knee joint.

Can I drive after hinged knee replacement surgery?

You should avoid driving until you have regained sufficient strength, mobility, and reflexes, which typically takes about four to six weeks.

Will I need to use assistive devices like walkers or crutches after surgery?

Yes, you may need to use assistive devices such as walkers or crutches initially to support your weight and facilitate walking. Your physical therapist will guide you on their proper use.

How long will the implants used in hinged knee replacement surgery last?

The longevity of knee replacement implants varies depending on factors such as implant design, patient activity level, and overall health. However, modern implants are designed to last 15-20 years or more in many cases.

Can hinged knee replacement surgery be performed on both knees simultaneously?

In some cases, bilateral hinged knee replacement surgery may be considered, but it depends on factors such as the patient’s overall health and the complexity of the procedure. This decision is made on a case-by-case basis.

Will I be able to bend my knee normally after hinged knee replacement surgery?

Yes, the goal of hinged knee replacement surgery is to restore as much normal function and range of motion to the knee as possible. However, it may take time and diligent rehabilitation to achieve optimal flexibility.

What are the potential complications of hinged knee replacement surgery?

Complications can include infection, blood clots, implant wear or loosening, stiffness, and nerve or blood vessel injury. Your surgeon will discuss these risks with you before surgery.

How soon can I return to work after hinged knee replacement surgery?

The timing of your return to work depends on factors such as the physical demands of your job, your overall health, and the progress of your recovery. Desk-based jobs may allow for a quicker return, while physically demanding jobs may require more time off.

Will I need to take pain medication after hinged knee replacement surgery?

Pain medication is often prescribed following surgery to manage discomfort during the initial recovery period. Your surgeon will provide guidance on the appropriate use of pain medication.

Can I participate in sports or exercise after hinged knee replacement surgery?

While low-impact activities such as swimming, cycling, and walking are generally encouraged after hinged knee replacement surgery, high-impact sports or activities that involve twisting or pivoting may need to be avoided to protect the implant.

What can I do to prepare for hinged knee replacement surgery?

Preparing for hinged knee replacement surgery may include attending pre-operative appointments, completing any necessary tests or screenings, arranging for help at home during recovery, and following any pre-operative instructions provided by your surgeon.

How long will I need to stay in the hospital after hinged knee replacement surgery?

Hospital stays after hinged knee replacement surgery typically range from one to three days, depending on individual factors such as overall health and progress of recovery.

Will I need to wear a brace after hinged knee replacement surgery?

A brace may be prescribed for a short period after surgery to provide additional support and stability to the knee as it heals. Your surgeon will advise you on its use.

Are there any alternatives to hinged knee replacement surgery?

Depending on your specific condition, alternatives to hinged knee replacement surgery may include traditional knee replacement, partial knee replacement, or conservative treatments such as medication, physical therapy, and injections.

How often will I need to follow up with my surgeon after hinged knee replacement surgery?

Follow-up appointments with your surgeon are typically scheduled at regular intervals after surgery to monitor your progress, address any concerns, and assess the function of the knee implant.

Will I need to make any modifications to my home after hinged knee replacement surgery?

Depending on your mobility and accessibility needs, you may need to make temporary modifications to your home, such as installing handrails or raised toilet seats, to facilitate your recovery.

Can hinged knee replacement surgery be performed on older adults?

Age alone is not a determining factor for candidacy for hinged knee replacement surgery. As long as the patient is healthy enough to undergo surgery and has realistic expectations for the outcome, age is not a barrier to treatment.


My name is Dr. Suhirad Khokhar, and am an orthopaedic surgeon. I completed my MBBS (Bachelor of Medicine & Bachelor of Surgery) at Govt. Medical College, Patiala, India.

I specialize in musculoskeletal disorders and their management, and have personally approved of and written this content.

My profile page has all of my educational information, work experience, and all the pages on this site that I've contributed to.