Advances in recent decades are making hip and knee joint replacement a more attractive option for many patients. If you know someone who underwent joint replacement decades ago, your experience is likely to be quite different.1
“When a patient’s quality of life and activities are severely curtailed by hip or knee arthritis, then hip and knee joint replacement may be the right options to restore function, provide pain relief and allow patients to return to the activities they enjoy,” said Dr. J. Conner Ryan, an orthopedic surgeon on the medical staff at Texas Health Center for Diagnostics and Surgery (THCDS). 
Reasons for Joint Replacement Surgery
Joint replacement is typically prescribed for patients with debilitating arthritis, an injury or other issue that causes pain or disability.2
“The most common underlying reason that leads to joint replacement surgery is osteoarthritis or other inflammatory conditions such as rheumatoid or psoriatic arthritis,” said Dr. Ryan. “In some cases, osteonecrosis (or “bone death”) due to a damaged blood supply to the bone can cause a painful joint. Some patients may have a history of fracture or trauma to a joint which can lead to joint replacement surgery as well.”
First, understand what joint replacement is – and isn’t.
Joints are parts of the body that connect two or more bones and allow for mobility. Joint replacement involves replacing a worn-out joint with metal and highly durable plastic components to resurface the damaged area. Both procedures may be performed to treat osteoarthritis, rheumatoid arthritis or post-traumatic arthritis related to a hip or knee injury.3
Anatomy of a knee. The knee joint connects two long leg bones, held together by muscles, ligaments, and tendons. Each bone end is covered with a layer of cartilage that absorbs shock and protects the knee. Two groups of muscles are also involved in the knee: quadriceps (front of the thighs), which straighten the legs, and the hamstrings, (back of the thighs) which bend the leg at the knee. Parts of the knee also include the tibia, the shin bone or larger bone of the lower leg; femur, the thighbone; and the patella, or kneecap.4
In knee replacement (also called knee arthroplasty or total knee replacement), the surgeon resurfaces parts of the joint damaged by arthritis. Metal and plastic parts are used to cap the ends of the bones that form the knee joint, along with the kneecap.5
But the term “joint replacement” can be a bit confusing.
“One common misconception related to total knee replacement is that the surgeon removes entire portions of the femur,” said Dr. Ryan. “In reality, we attempt to conserve as much bone as possible; what we’re actually doing is resurfacing the knee joint.”
Hip replacement. In a total hip replacement (also called total hip arthroplasty), the damaged bone and cartilage are removed and replaced with prosthetic components made with metal, ceramic and very wear-resistant plastic.6 This artificial joint (prosthesis) helps reduce pain and improve function. Hip replacement surgery may be an option if hip pain interferes with daily activities and non-surgical treatments haven't helped or are no longer effective. As with knee replacement, arthritis damage is the most common reason that leads to hip replacement.7
The Joint Replacement Journey
The process leading to joint replacement surgery begins with a thorough workup and evaluation. Surgeons typically do not advise patients to proceed with surgery unless more conservative measures to treat the symptoms have been tried and failed.
“Generally, joint replacement is recommended only after patients have tried non-surgical treatments such as topical agents, nonsteroidal anti-inflammatory drugs (NSAIDs), injections, bracing, and walking aids without achieving lasting relief,” said Dr. Ryan.
Prior to surgery, patients may also undergo evaluation with a cardiologist or other specialist to make sure they are medically fit for anesthesia and surgery.
“In some cases, back pain can also overlap with these issues, so it is important to do a thorough patient history and workup to decipher what is going on with the patient,” said Dr. Ryan. Before surgery, patients typically undergo a patient history, physical examination and imaging studies (CT, MRI, x-ray) as needed.”
After the Procedure
Most patients who undergo joint replacement surgery at THCDS are admitted to the hospital overnight and return home the next day. Physical therapy usually begins soon after. The majority of patients will feel as though they have made good progress with pain control and function between six weeks and three months after surgery. However, overall recovery time will depend on the patient’s functional and medical status prior to the surgery; some patients may take as long as a year to fully recover.8
As with any surgery, this procedure poses risks of complications, which may include bleeding, infection, blood clots, or a loosening, instability, or wearing out of the prosthesis. The replacement knee joint may need to be revised or replaced in the future. There may be other risks depending on the patient’s individual medical condition. While these complications are typically manageable, and infrequent, it’s important for patient to understand the potential for risk and discuss any concerns with the doctor prior to the procedure.9
Frequently Asked Questions
How long does it take to recover from joint replacement?
Barring any complications, many patients are able to return to most normal activities and walk without the need of assistive devices between two to six weeks after surgery. Recovery from hip replacement surgery tends to take less time than knee replacement surgery; some patients may need up to a year to recover from knee replacement surgery.10
Does joint replacement stop arthritis?
For most patients, total joint replacement surgery can be a lifelong solution for arthritis of the hip or knee. Total joint replacement should be considered as a possible treatment option only
after a reasonable attempt at non-surgical management has been determined to be unsuccessful.11
For more information about knee replacement, visit the THCDS Knee Replacement Services page and meet the THCDS joint replacement medical team here.
Learn more about what to expect with knee replacement surgery and follow the THCDS knee replacement blog here.
Sources:
1 Rehabil Assist Technol Eng. 2021 Jan-Dec. Trends and developments in hip and knee arthroplasty technology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7874345/
2 American Academy of Orthopaedic Surgeons, Total Joint Replacement, OrthoInfo. https://orthoinfo.aaos.org/en/treatment/total-joint-replacement/
3 Understand Your Joint Surgery Options, Arthritis Foundation. https://www.arthritis.org/health-wellness/treatment/joint-surgery/safety-and-risks/understand-your-joint-surgery-options
4 Knee Replacement Surgery. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/knee-replacement-surgery-procedure
5 Interview with Dr. Ryan
6 Hip Replacement. American Association of Orthopaedic Surgeons. https://orthoinfo.aaos.org/en/treatment/total-hip-replacement
7 Hip Replacement, Mayo Clinic. https://www.mayoclinic.org/tests-procedures/hip-replacement/about/pac-20385042
8 Source: Email interview with Dr. Ryan.
9 Risks of hip and knee replacement. Medline Plus. https://medlineplus.gov/ency/patientinstructions/000375.htm
10 Source: interview with Dr. Ryan plus https://www.ctortho.com/2022/05/13/how-long-does-it-take-to-recover-from-a-knee-replacement/
11 Joint Replacement Surgery, American College of Rheumatology. rheumatology.org https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Treatments/Joint-Replacement-Surgery