# Help w/Distal Femur Replacement w/hinged TKA



## pmogel (Dec 17, 2014)

I really need help with this case because timely filing is an issue with this one.  

The surgeon feels it should be coded:

27487-22
27365-59
76000-26

I don't agree with 27365-59.  At the most, I considered 27360-59.  How would you code this surgery?

PREOPERATIVE DIAGNOSIS(ES):
1.  Periprosthetic left distal femur fracture.
2.  Severe osteoporosis.
POSTOPERATIVE DIAGNOSIS(ES):  Same. PROCEDURE(S):
1.  Radical resection, left distal femur.
2.  Explant left total knee arthroplasty.
3.  Left distal femur replacement with hinged left total knee arthroplasty.
4.  Fluoroscopy, left lower extremity.

INDICATION FOR PROCEDURE(S):  A76-year-old female approximately one week status post primary left total knee arthroplasty done at an outside facility.  She unfortunately fell at home in the days following surgery resulting in a distal periprosthetic  left femur fracture.  She was transferred in to [hospital] campus for orthopedic management given the possibility for potential tumor type of prosthesis.  She was evaluated medically and cleared for surgery. Surgical options were discussed at length with the patient and family including attempts at open reduction and internal fixation versus the above-named procedures.  The risks and benefits of both were outlined.
I did express to them my concerns for our ability to obtain reliable fixation given the type of implants she currently has as well as the extremely osteoporotic nature of her bone.  Risks of surgery were outlined, most notably infection, blood vessel or nerve damage, stiffness, pain, limited ability to ambulate and need for further or additional surgery.  Informed consent was obtained.

DESCRIPTION OF PROCEDURE:  After identifying the left lower extremity as the correct operative site, the patient brought to the operating room where spinal was placed.  She was then anesthetized.  She was situated supine on the operating table.  A timeout was completed and preoperative prophylactic antibiotics given.  The left lower extremity was prepped
and draped in the usual sterile fashion.

Utilizing her previous anterior skin incision, we performed an anterior approach to the knee.  We made a median parapatellar arthrotomy extending this proximally through the quadriceps tendon to gain appropriate exposure to the distal femur.  There was a significant amount of hematoma and soft tissue trauma.  We did culture the joint fluid which was sent for stat Gram stain showing no evidence of microorganisms.   Her quadriceps and patella tendons were intact without evidence of compromise.  Hematoma and soft tissue debris were cleared from the joint so that we could inspect the fracture site.

The fracture was very distal extending down to just below the level of the prosthesis.  The bone was of very poor quality which we thought precluded reliable internal fixation and we elected at that point to proceed with resection of the distal femur, explant of her total knee components and the placement of distal femur prosthesis with hinged total knee.  We carefully freed all soft tissue attachments from the
distal femur including the collateral ligaments and capsule.  The distal femoral prosthesis was removed exposing the fracture site.  A fresh osteotomy was made transversely across the distal femur above the fracture site.  We then turned our attention to the tibial component.

We gently debonded the cement interface between implant and bone utilizing a combination of osteotomes and curettes.  Ultimately, we were successful in explanting the tibial prosthesis with minimal bone loss. The patellar component was left intact.  We irrigated copiously and proceeded then with the reconstructive portion of the case.

The tibial canal was debrided of all cement.  We then reamed the tibia
in anticipation of stemmed components.  An intramedullary reference guide was used to freshen our tibial osteotomy proximally.  The patella tendon was protected while the tibial cut was made.  We then sized the tibia with the Stryker GMRS system.  Rotation of the component was determined and the necessary keel punch performed.  We then turned our attention to the femur.

Again, we reamed the femur sequentially to allow for placement of an appropriate-sized  stemmed component in combination with our distal femur.  Trial components were placed and x-ray brought in to assess component positioning.  We were very satisfied with this.  The trial components were removed.  Cement restrictors were placed both up the
femoral canal and down the tibial canal.  We copiously irrigated all the bony interfaces to prepare for cementing of our components.  Again, the Stryker GMRS system was utilized.

A size SM-1 tibial baseplate was selected with a 40 mm stem extender. This component was cemented in place without difficulty.  Femoral component utilized was a standard distal femoral component for the left knee with a 13 mm stem measuring 127 mm in length.  This was cemented in place ensuring the correct rotation.  A trial bearing was inserted and the knee brought into extension while the cement was allowed to harden. Excess cement was removed.

We then trialed different bearing sizes and elected to use a 16 mm mobile hinged knee bearing.  This was then inserted per manufacturer guidelines.  Patellar tracking was assessed and found to be appropriate. Rotation and length were very satisfactory.  Range of motion was
assessed and found to be very adequate as well.

We copiously irrigated and ensured meticulous hemostasis.  Again, the extensor mechanism was assessed and found to be competent.  A drain was placed in the wound exiting proximally.  Before closure, we placed
1 gram of vancomycin powder into the knee joint and surrounding soft tissues.

We then closed the arthrotomy with a combination of Vicryl suture.  The subcutaneous tissue and skin was closed with Monocryl, staples and interrupted nylon suture.  The superficial layer of tissues was very tenuous given her recent surgical and trauma history.  We then placed a sterile dressing and a knee immobilizer.

She was then awakened, extubated, taken to the recovery room in stable condition.  No complications identified.  She seemed to tolerate the procedure well.



Thank you to anyone who can help 
Patty M., CPC


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