Replace and Repair Synovial Joints

In Chapter 9 we learn the objective of describing the structural features of a synovial joint, and the function of additional structures associated with synovial joints. In this report, I will be discussing the risk factors when synovial joints like hip joints are damaged and how to repair them with Total Hip Arthroplasty. I have also created a hip joint replacement completely out of cake, as shown in the images above.

Synovial joints are the most common type of joint in the body (Betts, 2022). They differ from fibrous or cartilaginous joints by having a joint cavity. The joint cavity is the site at which the articulating surfaces of the bones contact each other. The articulating surfaces at a synovial joint are not directly connected with fibrous connective tissue or cartilage. This gives the bones of a synovial joint the ability to move smoothly against each other, allowing for increased joint mobility. 

The type of synovial joint with the greatest range of motion is the ball-and-socket joint. The rounded head of one bone (the ball) fits into the concave articulation (the socket) of the adjacent bone. Some examples of ball-and-socket joints are the hip joint and the shoulder joint. At the hip joint, the head of the femur articulates with the acetabulum of the hip bone. Because hip joints have such a range of motion this leads to wear and tear, or diseases like osteoarthritis.

Osteoarthritis is the most common type of arthritis caused by numerous risk factors, like old age, injury to a joint, jobs that involve physical labor, sports with running, twisting or throwing actions, and being overweight. When you fracture your hip or have diseases like arthritis, osteoarthritis, rheumatoid arthritis, or osteonecrosis you may need hip replacement surgery. Hip replacement surgery, or total hip arthroplasty (THA) is a surgical procedure in which an orthopedic surgeon removes the diseased parts of the hip joint and replaces them with new, artificial parts (US DHSS, 2023). Multiple types of THA surgeries have improved the quality of life in many patients and have become one of the most reliable surgical interventions (Rajiv, 2023). 

The top three approaches for THA are the Direct Anterior Approach (DAA), Posterior Approach (PA), and Lateral Approach (LA). The operative approach can affect the efficacy and safety of THA (JAMA Network Open, 2023). All surgeries carry a percentage of risk. The main difference between these three procedures is where you surgically enter to replace the hip joint. DAA enters more towards the front of the hip joint, PA enters more towards the back of your hip joint and LA enters directly into the hip to reach the hip joint. All of these procedures replace the hip joint to give back a full range of motion, pain relief, and overall increase long-term mobility. There are some aftermath risk factors associated with THA, like infection, soreness, blood clots, dislocation or loosening, and nerve damage. All of these are worth getting back the chance to walk, run, sit, etc. 

Overall, synovial joints while being the most common and offering the most mobility are inevitable to start to diminish. Whether it’s by old age or disease, you have the option to regain full function with different approaches to surgery. 


Betts, G. & Desiaz, P. (2022). Anatomy & Physiology (2nd Ed). OpenStax. Free Anatomy And Physiology 2e Textbook for Download – OpenStax

JAMA Network Open. (2023). Evaluation of comparative efficacy and safety of surgical approaches for total hip arthroplasty. 

Supra, R., Agrawal, D. K., & Supra, R. (2023, March 15). Surgical approaches in total hip arthroplasty. Journal of Orthopaedics and Sports Medicine. 

U.S. Department of Health and Human Services. (2023, August 30). NIAMS health information on hip replacement. National Institute of Arthritis and Musculoskeletal and Skin Diseases.