Hip Replacement Problems
Indicative Timeline

Introduction

This site primarily focuses on hip replacement problems where the patient has received a hip implant that is subject to a recall, or where there is an emerging concern about the performance of a particular type of implant, but a recall has not yet taken place.

The point in time after initial surgery at which hip implant failure occurs will be of interest to a patient's orthopaedic surgeon in his assessment and diagnosis of the root cause of a hip replacement problem.

Included on this page is a simple timeline against which the whole range of hip replacement problems and possible outcomes can be considered.

Timeline for Hip Replacement Problems

The timeline diagram below is intended to provide a backdrop and draw the distinction between

  • hip replacement problems that occur at or towards the end of the expected useful life of an implant (time period Z - outside of the scope of this website)
  • compared with hip implant failure that occurs earlier
    • either failure to recover from the initial operation (period X),
    • or, failure during the period in which good performance of the joint could reasonably be expected (period Y)

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Click on the Diagram (above) to view a larger version; then Click on the 'Close' button or the dark area around the expanded image to return to the original page.

Possible Root Causes

When a particular type of hip implant device exhibits higher than expected revision rates at given time intervals following the original surgery, all interested parties will want to understand the root cause as a matter of priority. Some devices that have been recalled in recent years have exhibited failure rates significantly higher than were anticipated when the product was introduced.

For example, hip replacement problems that occur say 5-8 years following the original surgery may suggest that a hip implant device is potentially faulty, but there are a number of equally valid alternative explanations for hip implant failure in that timescale, including for example: the patient's lifestyle, weight or unusually high levels of physical activity.

Classification of Risks

When attempting to understand and assess a problem with hip replacement it is important to keep in mind the full spectrum of risks that are inherent to all hip replacement surgery. For ease of cross referencing within this site, I have grouped these risks below into one of three categories labeled below as P, Q & R.

P - The general risks of hip surgery include:

  • Wound infection
  • Adverse reaction to the anaesthetic
  • Excessive bleeding
  • Heart attack
  • Blood clots

Q - In addition, regardless of the type of hip implant used, there may be adverse events after surgery, including:

  • Device breakage or loosening
  • Difference in leg length
  • Joint infection
  • Hip dislocation
  • Bone fracture
  • Nerve damage resulting in weakness and / or numbness
  • Bone loss

R - There is also the risk that other symptoms might present after surgery that may indicate that a hip implant device is not functioning as intended. These symptoms include:

  • Noise from the hip joint (grinding, clicking, popping, or squeaking)
  • A limp or other deterioration in walking ability
  • Pain in the hip area, leg or groin
  • Swelling at or near the hip area

Relating the Risks of Hip Surgery to Recalled Hip Implant Devices

Hip implant recall notices typically flag a variety of reported adverse symptoms which include:

  • Component loosening
  • Component mis-alignment
  • Dislocation
  • Bone fracture
  • Infection
  • Pain and / or swelling
  • A range of symptoms that may be related to metal sensitivity (cobalt & chromium)

Summary

The brief discussion above highlights the complex nature of replacement hip problems and the need in every case for expert medical assessment, and possibly testing, to allow the orthopedic surgeon to form his opinion on the root cause of the problem.

Post-operative hip replacement problems can be a function of one or more of:

  • The inherent risks of hip surgery (outlined above at P, Q and R)
  • Failure on part of the orthopedic surgeon to implant (fit) the device properly (medical or surgical malpractice) - examples include:
    • Mis-alignment of components
    • Problems with bonding / fixing the implant to the healthy bone (use of the wrong type of cement or grout)
    • Mixing incompatible components from different hip implant systems
    • Selection of a device that is inappropriate for a particular patient (size or design of the device; or material from which the device is made)
  • Patient-specific issues can cause or worsen hip replacement problems such as: higher than recommended activity levels; excess body weight; other lifestyle influences
  • Defective implant - either defective design, or a problem in the manufacturing process