Get the Jump on Joint Replacement

Vol. 16 •Issue 11 • Page 8
CCS Prep!

Get the Jump on Joint Replacement

Total joint replacement (TJR) and, more specifically, total knee or total hip replacement procedures, have become two of the most commonly performed and successful procedures in medicine today. It’s estimated that this year nearly 2 million primary joint replacement procedures will be performed in the U.S., along with 750,000 joint replacement revision procedures. Several factors have contributed to the explosive growth of these services. The overall population is aging, but many of the “senior” members of society are more active and are requesting these procedures at younger ages than their parents’ generation did. Add this to clinical factors related to implant longevity and the need for increased TJR services is clear to see.

To fully understand the codes associated with both the diagnoses and procedures related to TJR, it’s helpful to understand the background and causes. The vast majority of TJR patients suffer from arthritis, which is the second most common chronic disease in the U.S. today. Although most commonly associated with the elderly, 20 percent to 30 percent of people over the age of 70 suffer from osteoarthritis of the hip. The disease also affects 32 million people of all ages throughout the country. Total costs associated with arthritis amount to more than $82 billion, which includes drug and hospital costs, nursing home costs and lost productivity. And while non-operative treatment options are typically attempted before moving to a surgical treatment option, for many people the non-operative solutions are only temporary and do not offer a long-term solution. Non-operative options include activity modification, weight loss, physical therapy, drug injections or other medication regimens. After these options have been exhausted, the patient may be offered a surgical treatment option, which may include a joint preserving procedure (such as arthroscopy, osteotomy or cartilage transplantation) or arthroplasty. The arthroplasty methods include hemi-arthroplasty (partial joint replacement), a resurfacing arthroplasty or the TJR option.

Coding staffs don’t generally have trouble assigning diagnosis codes for patients with arthritis undergoing initial joint replacement. But as younger and more active patients begin having problems over time with their prostheses, the codes describing these joint replacement complications have become much more specific. Causes of TJR failure may be varied and can include:

  • Mechanical loosening
  • Articular bearing surface wear
  • Infection
  • Instability
  • Osteolysis
  • Peri-prosthetic fracture
  • Implant failure

    A small proportion (less than 10 percent) of TJR complications occur within the first 5 years, which is considered an “early” complication. These typically involve dislocation, infection or an implant failure. The majority of TJR complications occurs after the first 5 years and may involve mechanical loosening, peri-prosthetic fracture, osteolysis or wear of the articular bearing surface, which increases over time. When the articular bearing surface wear has progressed to a point where the prosthesis has loosened or the patient experiences significant pain, a revision of the TJR is usually recommended.

    When a fracture of a prosthetic joint is due to trauma, it should be coded to a traumatic fracture code with the appropriate V-code from category V43.6 (Joint replacement status), to indicate the specific joint involved. If a pathologic fracture of a prosthetic joint is documented resulting from an underlying condition (such as osteoporsis or a neoplasm), the cases should be coded as a pathologic fracture, and again, the appropriate code from the V43.6 category should be added as a secondary diagnosis. Infections of a prosthetic joint are assigned to code 996.66 (Infection and inflammatory reaction due to internal joint prosthesis). In some cases, the only complication documented may be pain, which is assigned to code 996.77 (Other complications due to internal joint prosthesis).

    New Diagnosis Codes

    Effective Oct. 1, 2005, new diagnosis codes were developed that provide more specificity in the type of TJR mechanical complication documented. When these codes are assigned, an instructional note indicates: “Use additional code to identify prosthetic joint with mechanical complication (V43.60 – V43.69).” The first of the newly developed codes is the most non-specific. It describes an “unspecified mechanical complication” and should be avoided if possible. If the medical record does not indicate the complication involved, the physician should be queried for more information. This new range of codes is as follows:

    996.40 Unspecified mechanical complication of internal orthopedic device, implant or graft

    996.41 Mechanical loosening of prosthetic joint

    Aseptic loosening

    996.42 Dislocation of prosthetic joint

    Instability of prosthetic joint

    Subluxation of prosthetic joint

    996.43 Prosthetic joint implant failure

    Breakage (fracture) of prosthetic joint

    996.44 Peri-prosthetic fracture around prosthetic joint

    996.45 Peri-prosthetic osteolysis

    996.46 Articular bearing surface wear of prosthetic joint

    996.47 Other mechanical complication of prosthetic joint implant

    996.48 Other mechanical complication of other internal orthopedic device, implant and graft

    Note that there is an EXCLUDES note under code 996.48, indicating that it is not for use when a mechanical complication involves a prosthetic joint implant (the coder is then referenced to range 996.41-996.47).

    New Procedure Codes

    Also effective Oct. 1, 2005, new procedure codes were released that will allow more specific identification of varying types of total or partial joint revision procedures. To assign these codes appropriately, it’s absolutely essential that the coder have the operative report available so that each component of the revision procedure may be properly identified. Note that for the initial total or partial joint replacement procedures, codes 81.51, 81.52 and 81.54 are still reported. If there is no specification of the type of joint prosthesis revision that was performed, either code 81.53 (Revision of hip replacement, not otherwise specified) or 81.55 (Revision of knee replacement, not otherwise specified) should be assigned. But if at all possible, the coder should query the physician for the specific type of revision procedure performed.

    Hip Replacement Revision

    Revision hip replacement procedures can involve replacing any or all of the components initially replaced, which include the femoral component, the acetabular component and the bearing surface (the femoral head and acetabular liner). The complexity will vary, depending on factors such as the reason for the prosthesis failure, the type of implants initially used in the primary arthroplasty procedure, the amount and quality of the patient’s remaining bone stock, and the overall health and anatomy of the patient. The different types of procedures are briefly described below:

    00.70 Revision of hip replacement, both acetabular and femoral components: This type of revision is the most complex, most labor and resource intensive and carries the highest complication rate. Both components have failed and the procedure may require extensive surgical exposures, specialized implants and techniques for reconstruction. Patient outcomes for this type of revision procedure are the least predictable of all hip replacement revision services.

    00.71 Revision of hip replacement, acetabular component: Typically, the indications for this type of revision include aseptic loosening (often associated with osteolysis), wear of the modular weight bearing surface, malposition of the component, which can lead to recurrent dislocation, or infection. The procedure involves removal and exchange of the entire acetabular implant, including both the metal shell and the polyethylene, ceramic or metal modular bearing surface. In some cases the reconstruction requires only a reimplantation of a standard hemispherical implant that’s slightly larger than that initially implanted during the first arthroplasty procedure. In other cases there may be a large amount of bone destruction due to osteolysis or component migration and significant amounts of bone grafting may be necessary.

    00.72 Revision of hip replacement, femoral component: Again, the indications for this type of revision include aseptic loosening (often associated with osteolysis), wear of the modular weight-bearing surface, malposition of the component, which can lead to recurrent dislocation, infection or periprosthetic fracture. The procedure requires removal of the implant and removal of the surrounding cement may require specialized techniques, including osteotomizing (cutting) the femur bone to reach the implant, and ultrasound probes may also be used to remove the residual cement. Specialized revision implants are typically required, depending upon the amount of bone loss and the quality of the remaining bone.

    00.73 Revision of hip replacement, acetabular liner and/or femoral head only: One of the most common revision procedures performed, this service involves removal and exchange of the modular femoral head and acetabular liner. The most common indications include wearing of the polyethylene bearing surface or recurrent dislocation of the prosthetic hip. In many cases, this procedure can be accomplished without removing the other components, making its recovery time significantly shorter than those required for the other revision procedures.

    In addition to assigning the codes most appropriate for the revision procedure performed, the coder is also instructed to assign one of three codes to indicate the hip replacement implant bearing surface, if this information is available. These codes may be assigned as secondary codes for hip replacement or revision of hip replacement procedures. The codes are:

    00.74 Hip replacement bearing surface, metal on polyethylene

    00.75 Hip replacement bearing surface, metal-on-metal

    00.76 Hip replacement bearing surface, ceramic-on-ceramic

    Knee Replacement Revision

    Also new for FY 2006, effective Oct.1, 2005, new category 00.8 was developed to classify specific knee replacement revision procedures. Similar in some ways to the hip replacement revision services, knee replacement revisions may involve one, some or all of the components initially implanted. If two components are revised, two codes from this category should be assigned; if all three components are replaced, code 00.80 should be reported. The codes are described below:

    00.80 Revision of knee replacement, total (all components): This is the most common type of revision performed for total knee replacement revisions and is performed much more often than total (all component replacement) of hip implants. One of the major reasons that all components are replaced is that the separate knee replacement implants aren’t compatible across vendors or types of prostheses. In most cases, osteotomization (cutting) of the tibia bone is required to adequately expose the knee joint and implant components. If extensive bone loss is present, significant bone grafting may be necessary to fill bony defects.

    00.81 Revision of knee replacement, tibial component: Most often, tibial component revisions are performed for patients with signs of wearing of the modular bearing surface, aseptic loosening (often associated with osteolysis) or infection. It involves removal and exchange of the entire tibial component, including both the metal base plate and the modular polyethylene bearing surface. Depending on the amount of bone loss and the integrity of the ligaments around the knee, specialized implants, metal augments or bone grafts may be required.

    00.82 Revision of knee replacement, femoral component: Common indications for femoral component revision includes aseptic loosening (with or without associated osteolysis) or infection. It involves removal and exchange of the metal implant that covers the end of the distal femur. If extensive bone loss is found, specialized implants with stems that extend into the femoral canal and/or metal augments or bone grafts may be required.

    00.83 Revision of knee replacement, patellar component: One of the most common problems related to any knee replacement revision is one involving the patello-femoral joint. In some cases, mal-tracking of the patella in the femoral groove leading to wear and breakage of the implant, fracture of the patella with or without loosening of the patellar implant or rupture of the quadriceps or patellar tendon or infection are present. The procedure involves removal and exchange of the metal-backed polyethylene patellar component.

    00.84 Revision of knee replacement, tibial insert (liner): This type of revision involves removal and exchange of the modular tibial bearing surface. The modular polyethylene bearing surface is removed without removing the femoral, tibial or patellar implants. It’s typically performed for instability (looseness) of the prosthetic knee joint or for wear of the polyethylene bearing surface.

    Note that if any cement or joint spacer is removed at the same operative episode, code 84.57 should be assigned as a secondary procedure.

    The addition of these new and more specific diagnosis and procedure codes will allow clinicians and researchers to track clinical outcomes and complications related to new techniques and technologies more closely and accurately. The type and cause of the joint replacement failure will determine the type of revision joint replacement procedure and the new codes should match. Coding staffs should ensure that if a code for a specific type of TJR failure is present, that the revision procedure matches that diagnosis.

    Information related to joint replacement diagnoses and procedures may be found at the Web site for the National Center for Health Statistics at and in Coding Clinic for ICD-9-CM, 4th Quarter 2005, pp. 91 — 93 and 106 — 117. After review of these documents, test yourself with the following quiz.

    (Note: E-codes are not required for this quiz.)

    1. A 72-year-old male had previously undergone total hip replacement. He now returns with a loosened acetabular component that was causing significant pain. The patient was admitted and taken to the operating room for a procedure that included removal and replacement of the acetabular component only, using a metal-on-polyethylene bearing surface. The appropriate diagnosis and procedure codes are:

    a. 996.4, V43.64, 00.71, 00.74

    b. 996.77, V43.64, 00.71, 00.76

    c. 996.66, V43.64, 00.70, 00.77

    d. 996.41, V43.64, 00.71, 00.74

    2. A 69-year-old woman had a total hip replacement 1 year ago and has had problems with infections of the prosthesis since that time. On this admission she was taken to surgery for revision of the total hip, which utilized combined components, ceramic-on-ceramic implant bearing surface and removal of previously placed cement spacers. The appropriate diagnosis and procedure codes are:

    a. 996.77, V43.65, 00.70, 00.76

    b. 996.66, V43.64, 00.70, 00.76, 84.57

    c. 996.41, V43.64, 00.71, 00.76

    d. 996.41, V43.65, 00.71, 00.76, 84.57

    3. A 67-year-old male patient had a previously placed knee joint prosthesis and now returns with a periprosthetic fracture. No trauma was documented. Surgery included replacement of the femoral and tibial components. The appropriate diagnosis and procedure codes are:

    a. 996.44, V43.65, 00.81, 00.82

    b. 996.43, V43.65, 00.80

    c. 996.44, V43.65, 00.80

    d. 996.47, V43.65, 00.81, 00.82

    This month’s column has been prepared by Cheryl D’Amato, RHIT, CCS, director of HIM, and Melinda Stegman, MBA, CCS, manager of clinical HIM services at HSS, an Ingenix company ( HSS specializes in the development and use of software and e-commerce solutions for managing coding, reimbursement, compliance and denial management in the health care marketplace.

    Coding Clinic is published quarterly by the AHA.

    CPT is a registered trademark of the AMA.

    Answers to CCS PREP!: 1. d. The diagnosis code 996.41 (fifth digit required) indicates a loosening of the prosthetic joint and the V-code indicating hip replacement status also requires a fifth digit. Only the acetabular component was revised (00.71) and the implant bearing surface involved metal-on-polyethylene (00.74); 2. b. The principal diagnosis is infection of the joint prosthesis (996.66), the joint previously replaced and being treated on this admission involved the hip (V43.64), the revision procedure included replacement of both components (00.70), a ceramic-on-ceramic implant bearing surface (00.76) and removal of the cement spacer (84.57); 3. a. Because the problem with the joint prosthesis involved a peri-prosthetic fracture, assign code 996.44 as the principal diagnosis. The V43.65 reflects a knee replacement status and because only the femoral and tibial components were replaced, codes 00.81 and 00.82 are both assigned. All three components would have to be replaced to assign 00.80.