Overview
A revision total knee replacement is an operation in which part or all of a previously implanted knee replacement is removed and replaced. The reasons to revise a knee replacement are specific — the joint is painful, loose, infected, unstable, or the polyethylene spacer has worn — and not every ache in a replaced knee is a revision candidate. The workup is careful, and honest triage happens on the phone.
If you have a knee replacement — from here or from elsewhere — and are experiencing new pain, instability, swelling, or stiffness that is not settling, call our office before booking a clinic visit. Our team can usually tell on the phone whether the case fits our practice or whether you would be better served at a revision-specialty center. We would rather save you the trip than see you for something we would have to refer out.
Who is a Candidate
Most painful replaced knees are not revision candidates at first pass — the workup exists to separate component problems from soft-tissue, neurologic, or referred causes. Revision is considered when:
Polyethylene wear
X-ray, exam, and sometimes aspiration suggest that the plastic spacer has worn through or failed, with asymmetric joint-space collapse and mechanical symptoms. An isolated polyethylene exchange — where only the spacer is swapped and the metal components are retained — is often feasible.
Aseptic loosening
One or both components have lost their bond to bone. Imaging shows progressive radiolucent lines, component subsidence, or a shift in alignment compared to early postoperative films.
Instability
The knee buckles, gives way, or has a feeling of looseness that does not settle with bracing or therapy. Workup distinguishes collateral laxity, flexion-extension gap imbalance, and component malposition.
Infection
Periprosthetic joint infection is its own category. Superficial wound issues are different from deep infection around the components. Deep infection, especially with a chronic or draining sinus, usually requires a staged revision approach at a dedicated revision-specialty center rather than single-stage revision here.
Periprosthetic fracture
A fracture of the femur or tibia around the implant. Management depends on fracture pattern, component stability, and bone quality — some fixed with plating or nailing, some requiring revision of the implant.
How the Decision Is Made
The decision begins on the phone. Our scheduling team will ask when the replacement was done, where, the nature of the new symptoms, and whether there has been fever, drainage, or a recent procedure elsewhere. That conversation triages into three rough buckets:
Straightforward workup in our clinic
New knee pain without systemic signs, no draining wound, no recent invasive procedure elsewhere. Seen in clinic, imaged, and — if revision is indicated — planned here. Polyethylene exchange, single-component revision, and many full revisions fall in this bucket.
Evaluated here, planned for referral
Cases with massive bone loss requiring structural allograft or megaprostheses, suspected deep infection requiring staged reimplantation, or multi-component revisions with constraint escalation that are more appropriately handled at a dedicated revision-specialty center. We work up the case, make the diagnosis, and help the patient land in the right hands.
Referred directly
Acute infection with a draining sinus, hemodynamic instability, or a fracture pattern that needs specialty equipment we do not stock. The phone triage catches these and routes them immediately.
A typical in-clinic workup includes weight-bearing and lateral knee X-rays, inflammatory markers (ESR, CRP) if infection is on the differential, and often an intra-articular aspiration for cell count, crystals, and culture. Implant records are obtained when available — the component make and model informs whether an isolated polyethylene exchange is feasible.
What Revision Involves
Revision total knee replacement covers a spectrum, from a short operation that swaps only the plastic spacer to a reconstructive case that removes and replaces both metal components, addresses bone loss, and restores soft-tissue balance. The common threads are listed below — what is actually done in any given case depends on the findings at the time of surgery.
Exposure and implant assessment
The prior incision is usually reused. The knee is exposed, the polyethylene is removed, and each metal component is tested for stability. A component that is well-fixed to bone may be retained; a loose component comes out.
Component removal
If a component must be removed, it is done with instruments designed to preserve bone — thin osteotomes and oscillating saws at the bone-cement interface. The goal is to remove the implant without taking extra bone, because every millimeter of bone stock matters for the revision implant that goes back in.
Assessment of bone stock
After removal, the femoral and tibial surfaces are evaluated for contained and uncontained defects. Small defects are filled with bone cement or small metal augments; larger defects may need structural augmentation. Cases that require massive allograft or cone-and-sleeve reconstruction of very large defects are generally better served at a revision-specialty center.
Stems, augments, and constraint
Revision components differ from primary components in that they often rely on stems — extensions that engage the diaphysis of the femur or tibia — to unload the weaker metaphyseal bone. Augments are metal blocks that fill small defects. Constraint — how tightly the components are coupled to each other — is increased when collateral ligaments are deficient. The level of constraint chosen (from a more-constrained condylar-style insert up to a hinged design) is dictated by ligament integrity found at surgery.
Soft-tissue balance and alignment
As with a primary knee replacement, gap balancing and limb alignment determine how the knee feels and wears. In a revision the soft tissues are scarred and the landmarks are less forgiving, which is why revision cases take longer than primaries even when the hardware question looks simple.
Closure
The joint is irrigated, a drain is placed selectively, and the tissues are closed in layers. Intraoperative cultures are often sent even when infection was not the indication, because occult infection occasionally declares itself on the back end.
Recovery
Recovery after a revision total knee replacement is handled in qualitative phases, and the arc is generally slower than after a primary replacement because the soft tissues have already been operated on once and the bone stock is less forgiving.
Early recovery
Weight-bearing status depends on what was done — an isolated polyethylene exchange allows immediate weight-bearing, while a case with a structural augment or a periprosthetic fracture fixation may be protected. Assistive devices (walker, then cane) are used until the gait is secure. Physical therapy starts early, focused on motion and quadriceps reactivation.
Return to activity
Progression is gradual and guided by exam findings at each follow-up — swelling, range of motion, quadriceps strength, and gait — rather than a fixed calendar. Driving, return to desk work, return to physical work, and return to recreation each have their own criteria and are cleared one at a time.
Long-term surveillance
Revision knees are followed on a longer schedule than first-time replacements — periodic exam and X-rays to watch for polyethylene wear, component migration, and alignment change. Patients are asked to call early for new pain, drainage, or fever.
What Revision Treats
Physicians Who Perform Revision Total Knee Replacement
Providers Who Surgically Assist with Revision Total Knee Replacement
What to Expect from Our Practice
The posture at OSI New Braunfels is call-first screening, honest scope of practice, and continuity of care. If your case is one Dr. Vrana handles here, you will be seen in clinic, worked up, and — if revision is indicated — operated on by the same surgeon who saw you. If your case is better served at a dedicated revision-specialty center, our team will say so on the phone and help you find the right place. We would rather save you the trip than see you for something we would have to refer out.
Every operation carries risk. The risks we discuss with patients before revision arthroplasty include:
- bleeding and infection (including rare deep periprosthetic infection)
- anesthesia risk
- blood clot (DVT/PE) — mitigated by perioperative prophylaxis
- stiffness that sometimes requires manipulation under anesthesia
- continued pain when the source is not fully addressed by the revision
- periprosthetic fracture
- injury to the extensor mechanism
- wound-healing complications in a previously operated knee
- rare neurovascular injury around the popliteal space
- repeat revision over time if bone stock or soft-tissue integrity fail
Further Reading
External patient-education references and related OSI pages for additional background: