Revision Total Knee Arthroplasty - Wheeless' Textbook of Orthopaedics

- Assistance provided by Michael Berend MD.

- PreOperative Considerations and Implant Selection:
- work up of the painful TKR:

- Exposure for Revision Arthroplasty:
- surgical approach for primary TKR;
- intraoperative gram stain, frozen section, and culture

- Component Removal:
- prior to component removal, take the knee thru a ROM and evaluate patellar tracking and evaluate knee stability in extension, mid-flexion, and full flexion;
- it is important to consider patellar tracking, since this will affect final rotation of the femoral component;
- if their is optimal patellar tracking, then the surgeon should accept the orientation of the pre-existing femoral bone cuts;
- it is important to know the status of pre-existing flexion and extension gaps before the components are removed, since this will have a
bearing on anterior-posterior translation of the femoral medullary stem (and component);

- Tibial Preparation:

- Femoral Preparation:

- Revision of the Patellar component:

- Cement Considerations:
- before cement is mixed, clearly note areas of minor bone defects (between trial components and bone), and plan to add additional cement to these areas;
- before the cement is mixed, ensure that all components are laid out on the table;
- cementing technique:
- apply cement to only condylar surfaces if press-fit stems are being used;
- cement is applied to cut medullary surfaces, but in most cases cement is not placed into the medullary canal;
- if stems are being cemented, consider use of a cement plug and an injection gun;
- addition of antibiotics to cement
- in some patients, consideration the addition of antibiotics to cement:
- indicated if there are additional risk factors for infection;
- generally, either 600mg tobramycin or 500mg vancomycin is added per 40g bag of cement;
- ref: Stem fixation in revision total knee arthroplasty: a comparative analysis.

- Complications:
- infection:
- may occur in 4% of patients (which is roughly 10 time higher than should occur in primary knees);
- early failure:
- component survivorship is roughly 80 % at 8 years;
- good to excellent results occur 50-80% of the time with complications occurring 15-30%;
- wound comlications should be handled aggressively with skin graft, gastrocnemius flap or free flap;

- Postoperative Rehabilitation:
- quadriceps snip can be rehabilitated routinely
- quadriceps turndown or tubercle osteotomy requires no ROM for 2 weeks and no active extension for 2-6 weeks;