Introduction

Knee replacement surgery is a well-established and highly effective way to restore mobility and relieve pain for people with severe knee problems. While the surgery replaces parts of the knee joint, the patella—or kneecap—is a key player in how well the knee functions afterwards. Although modern techniques have improved outcomes considerably, patellar complications can still occur after surgery. These issues can be worrying but are generally well understood and manageable with expert care. In this article, we’ll explore the most common problems affecting the patella after knee replacement, drawing on the knowledge of Professor Paul Lee and the skilled team at MSK Doctors.

Why Do Patellar Complications Occur?

The knee is a complex joint, and the patella helps by improving the efficiency of the thigh muscles as you move. After knee replacement, changes in the joint’s anatomy and how the prosthetic parts are positioned can alter the forces acting on the patella. This may increase the chance of complications. Factors like implant alignment, surgical technique, and individual patient characteristics—such as bone quality and activity level—also play a role. That’s why experts like Professor Paul Lee emphasise thorough pre-surgery assessments at MSK Doctors to plan each operation carefully. A recent clinical study stressed that “patellar resurfacing must be performed with a high level of accuracy and precision since it is just as crucial as tibiofemoral replacement.” Another study found that “patellar obliquity alters patellofemoral tracking and regional loading—even without increasing total joint force,” showing how important correct alignment is.

Recognising Common Patellar Complications

After knee replacement, some common issues that may affect the patella include:

• Patellar fractures: breaks in the kneecap bone that can happen during or after surgery.
• Dislocation and subluxation: when the patella partially or fully moves out of its usual position.
• Implant loosening and wear: where parts of the prosthesis wear down or come loose, causing discomfort.
• Erosion and impingement: damage from abnormal friction or contact with nearby tissues.
• Osteonecrosis: loss of blood supply that can cause patella bone tissue to die.

A recent study reviewing patients after knee replacement reported seeing “patellar fracture, patellar maltracking, aseptic loosening, patellar osteonecrosis, polythene wear, and dislocation.” Laboratory research also highlights that “a medial-thick oblique patella consistently elevates central ridge pressures,” which can lead to problems if not managed carefully. Importantly, high-quality evidence shows that “patellar resurfacing reduced anterior knee pain compared with no resurfacing” and also lowered risks of revision surgery and other complications.

Symptoms and When to Seek Help

It’s important to be alert to warning signs of patellar problems. These include unexplained or persistent knee pain, swelling around the kneecap, feelings of instability or the knee giving way, and unusual sensations like clicking or grinding sounds when moving. If you notice any of these symptoms, it’s best to consult an orthopaedic specialist promptly. Early examination and diagnosis can prevent further damage and improve treatment success. The team at MSK Doctors, led by experts such as Professor Paul Lee, provides supportive and personalised care to help patients manage these issues confidently.

Prognosis, Management, and Minimising Risk

How patellar complications are managed depends on the specific problem and its severity. Treatments may range from careful observation and physiotherapy to strengthen surrounding muscles, through to revision surgery or adjustments to prosthetic parts. Patients often ask about returning to normal activities, long-term outlooks, and practical steps to avoid problems. It is essential to stick to rehabilitation programmes, respect weight-bearing and activity advice, and attend regular follow-ups. Research highlights the importance of precision in surgery, noting that “to reduce the danger of additional difficulties, patellar resurfacing must be performed with a high level of accuracy and precision.” Surgeons are also advised to “prioritise symmetric patellar resection” to prevent abnormal tracking and focal overload, which can cause patellofemoral symptoms after knee replacement. Choosing an experienced team, such as Professor Paul Lee and colleagues at MSK Doctors, can greatly improve recovery and reduce complications.

Conclusion

Patellar complications following knee replacement surgery can be challenging, but with timely and expert care, they are manageable. Advances in surgical techniques and comprehensive clinical support offer patients the best chance for a positive recovery. Partnering with knowledgeable professionals, including those at MSK Doctors led by Professor Paul Lee, helps ensure that you regain mobility, minimise discomfort, and enjoy a better quality of life after your knee replacement.

References

• Shaheen, U. U., Janjua, S. N., Iqbal, S., Noman, H. M., Ghouri, Q. M., & Khalid, M. N. (2024). Postoperative Complications of Patellar Resurfacing In Total Knee Replacement. Journal of Rawalpindi Medical College, 28(2). https://doi.org/10.37939/jrmc.v28i2.2410
• Shatrov, J., Boudali, A. M., Abe, K., Parker, D., Clarke, E., & Walter, W. L. (2025). Patellar obliquity causes altered patellofemoral biomechanics in total knee replacement: An in vitro study. Knee Surgery & Arthroscopy. https://doi.org/10.1002/ksa.70201
• Grela, M. E., Barrett, M. C., Kunutsor, S., Blom, A., Whitehouse, M., & Matharu, G. (2022). Clinical effectiveness of patellar resurfacing, no resurfacing and selective resurfacing in primary total knee replacement: systematic review and meta-analysis of interventional and observational evidence. BMC Musculoskeletal Disorders, 23, 1049. https://doi.org/10.1186/s12891-022-05877-7