Hip and knee replacements have been around for several decades, in fact, the first recorded attempt for a total hip replacement dates all the way back to 1891 when they created a femoral head replacement out of ivory. Hip and knee replacement procedures and implants have evolved since then of course, and today the implants are made of metal, plastic, or ceramic material.

The most common reasons that patients need a hip or knee replacement are as follows: osteoarthritis, rheumatoid arthritis, fractures, instability, osteonecrosis, avascular necrosis, childhood hip diseases and other pathologies. The extent of the damage that the above conditions have had on the hip and knee joints will be one of the determining factors in whether a partial or a total hip or knee replacement is performed.

Hip and knee replacements have similar recovery times. Most patient stay 1-3 days in the hospital and start physical therapy immediately following surgery. They even start walking on replaced joint the same day in most cases. Most patients can get back to their pre-surgery activities by 4-6 weeks, and enjoy their normal, everyday activities with a full recovery within 12 weeks.  

Understanding the affected joint’s anatomy will be important while reviewing the operative reports. The knee for example, is divided into three major compartments: medial, lateral, and patellofemoral compartments. Paying close attention to which compartments are treated is crucial in selecting the correct replacement code. A partial would include the condyle and plateau, plus either the medial or lateral compartments. A total knee replacement would again include the condyle and plateau, and both the medial and lateral compartments.

Hip and knee revisions and removals are necessary when the previously inserted prosthesis breaks, loosens or becomes infected. Revisions and removals are inherently more complicated than the original replacement procedure because they must remove the cement and other materials from the last surgery. Therefore, hip and knee revisions and removal procedures typically take longer than the original replacement procedures. It may also be necessary for the removal and replacement surgery to be a two-step process if an infection is present because the patient may have to be treated with a course of antibiotics after the prosthesis is removed and ensure the infection has cleared before the new implant can be replaced.

Overall, hip and knee removal and revision procedures have a similar recovery time to the replacement procedures as noted above. Although, the recovery time may be extended depending on it takes to replace the old implant with a new one, especially in cases where there is an infection present.

In conclusion, the necessary details to properly code for a hip or knee replacement, revision or removal will be in the operative note. Pay close attention to specificity and anatomy described to select the correct diagnosis and procedure.

Written by Cori Bowmer, CPC, CFPC, CPMA, CPPM, CRC