Orthopedic Coding Alert

Expert: “The best approach is the one your surgeon is the most familiar with.”

When a patient reports to their practitioner complaining of joint pain, orthopedic surgery may be in their near future. Coding choices for orthopedic surgical procedures can quickly overwhelm even a veteran coder.

For those who attended AAPC’s HEALTHCON 2026, they received vital information regarding some of these procedures from Nate Felt, MS, ATC, PTA, CPC. During his session, “Dissecting Orthopedic Surgeries,” Felt discussed the importance of understanding surgical approaches, types of prostheses, and the intricacies of knee, hip, and shoulder procedures, just to name a few. 

Consider this primer a resource to help you better understand the surgical methods used in hip repairs and the injuries or conditions that lead to them. You can also try your hand at a confounding coding example to aid your surgeons in submitting claims aimed at helping patients lead lives with less pain.

Research the Reasons for a Hip Replacement

A total hip replacement, also known as arthroplasty, is a surgical procedure to alleviate intense hip pain and improve mobility when joint damage makes everyday tasks difficult or painful. This surgery entails substituting the impaired bone and cartilage with synthetic prosthetic parts.

Common reasons patients may need a total hip replacement include:

• Congenital hip conditions: Structural irregularities like hip dysplasia, which is a condition where the hip doesn’t properly develop during childhood, can result in accelerated joint wear and tear.
• Hip fractures: Severe trauma or a fracture from a fall or accident that damages the hip joint beyond the ability to heal properly might require an arthroplasty.
• Osteonecrosis (avascular necrosis): This is a disorder in which the blood flow to the ball portion of the hip joint is interrupted, leading to the death and subsequent collapse of the bone.
• Osteoarthritis: The primary cause, often referred to as “degenerative arthritis,” occurs when the protective cartilage at the bone end gradually erodes, leading to discomfort due to bone-on-bone contact.
• Posttraumatic arthritis: This condition involves long-term joint damage, stiffness, and pain that develops years after a severe hip injury or fracture.
• Rheumatoid arthritis: This is a condition triggered by the body’s immune system that results in persistent inflammation of the joint’s lining, which in turn leads to the depletion of both cartilage and the bone beneath.

Understand the Anatomical Approaches for Hip Replacement

“It’s really important as a coder to know your anatomy,” Felt said. There are five main approaches when a surgeon performs hip replacement surgery. Understanding anatomy and anatomical directions will help when reading these in your practitioner’s notes:

• Medial approach: This is a less common approach where the surgeon accesses the hip joint from the inner thigh. It’s typically used for pediatric patients or specific hip conditions.
• Anterior approach: In this approach, the surgeon makes an incision at the front of the hip. It allows the surgeon to work between the muscles without detaching them from the hip or thighbones, keeping them intact.
• Anterolateral approach: This approach involves an incision on the side of the hip. The surgeon works between the top of the thigh bone and the outer rim of the pelvis. It provides good visibility of the hip joint and less risk of dislocation compared to the posterior approach.
• Direct lateral approach: Sometimes called the Hardinge approach, it involves the surgeon making an incision at the side of the hip. Less muscle damage occurs using this method.
• Posterior approach: This is the traditional approach where the surgeon makes an incision at the back of the hip. It provides a good view of the hip joint but has a higher risk of hip dislocation after surgery due to the amount of soft tissue disturbed during the procedure.

Felt stated, however, “The best approach is the one your surgeon is the most familiar with.”

Code This Tricky Total Hip Arthroplasty Case

Scenario: A patient presents following an infection of a total hip arthroplasty. The previously placed articulating antibiotic spacer is removed with placement of a new total hip arthroplasty (both components).

Answer: Felt explained that the correct answer here is 27132 (Conversion of previous hip surgery to total hip arthroplasty, with or without autograft or allograft). This may seem counterintuitive to most coders. Felt explained to the audience that in the above example, “They are taking out the antibiotic spacer, and then putting in the new prosthesis, so you need to use the ‘conversion to a total hip’ code.”

Another option Felt discussed with the audience for the above coding example was 27134 (Revision of total hip arthroplasty; both components, with or without autograft or allograft). He explained this option was incorrect for this scenario because per CPT^® Assistant guidelines, “Code 27134 is reported only when removal and replacement of the hip arthroplasty component(s) occur during the same operative session.” Felt then went on to say, “Most physicians ask, ‘Why am I not billing a revision code on this? I’m removing something and putting something new in.’ Because on stage 1, you did, too. On stage 1, you removed the prosthetic and you put in a spacer.”

Lindsey Bush, BA, MA, CPC, Production Editor, AAPC