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Like most things medical, understanding all of the words and terms associated with “joint replacement” is confusing. Reading through medical forums or listening to your doctor can feel like riding a bus in foreign country: you’re only guessing what everyone is talking about. On a vacation nodding along is totally fine, but when it comes to an upcoming hip replacement or knee replacement, it’s critical that you become more involved in the conversation.

In this post, we’ll crack the code on the many short forms, acronyms, abbreviations and tough-to-understand concepts associated with a hip or knee replacement. Getting better acquainted with the basics will give you full access to understanding what your doctor and peers are really talking about, allow you to ask better questions, and let you confidently lend your newfound expertise to other joint replacement newbies.

Read on as we answer questions like: What is the meaning of arthroplasty? Is there a difference between a joint replacement and arthroplasty? What does THR mean? And more.

The Basics: The Different Types of Replacements

Total Knee Replacement (TKR) or Total Knee Arthroplasty (TKA)

First of all, to clear up any confusion, it must be known that a total knee replacement (TKR) and total knee arthroplasty (TKA) are the exact same thing. Basically, “knee arthroplasty” is just the fancy pants version of “knee replacement”. Got it? Okay, good. Now you can confidently use both terms interchangeably. In a total knee replacement all of the damaged bone and cartilage is removed and resurfaced. The healthy bone is left intact to support the new artificial joint. The artificial joint is made up of as many as three different parts. Read about the many different types of artificial knee replacement components now!

Partial Knee Replacement (PKR) or Unicompartmental Knee Arthroplasty (UKA)

Once again, a partial knee replacement (PKR) is just the more common “street name” for unicompartmental knee replacement (UKA). They’re one in the same. As the name suggests, a partial knee replacement (also known as a PKR or UKA) is when one or more parts of the knee joint are replaced. The difference between a total and partial is that in a partial, the healthy parts of the knee joint are left as-is. Only about 10% of joint replacements are partial, with the overall preference to just do the whole kit and kaboodle. Here’s what’s really involved in a total and partial knee replacement.

Minimally Invasive Knee Replacement

With any type of knee replacement, the surgeon will take either a traditional or minimally invasive approach. With a minimally invasive approach, the exact same components are introduced to form the knee replacement. The main difference is the length of tissue (or incision) cut by the surgeon. With a minimally invasive replacement, the incision mark is 4-6 inches along (about half the size of a traditional replacement). The aim of minimally invasive is to cut less tissue and leave the quadricep tendon and muscle intact. Minimally invasive is still a relatively new offering and is not suitable or recommended for all patients. Learn more here.

Total Hip Replacement(THR)

A total hip replacement is sometimes called a traditional hip replacement surgery (hence the THR). The most common approach to a THR is performed in the posterior approach. In a posterior hip replacement, the incision is cut with the patient lying on their side at the upper thigh/buttock area. The incision is generally 10-12 inches in length, but with a “mini” posterior, the incision can be much smaller at just 4 inches in length. Posterior is the original, “catch-all” hip replacement type, used in the majority of cases by most surgeons. Read on about what to expect during hip replacement surgery.

Direct Anterior Hip Replacement (DAA)

The anterior replacement is less common as it is newer and technically difficult to perform with lower visibility for the surgeon. It is sometimes referred to as a minimally invasive hip replacement. The main difference between posterior and anterior is the site of the incision. With anterior, a smaller cut is made to the front of the upper thigh, with the patient lying on his or her back. An anterior approach is sometimes done in a special table called a Hana table. Like a mini-posterior, this approach is more muscle and tissue-saving as the incision is made in a way that better preserves muscle. As a result, it’s suggested that some patients can have a smoother recovery. In saying this, anterior is not recommended for every patient as it can be riskier and is not performed by all surgeons.

Bilateral Hip & Knee Replacement (BTHR, BTKR) or a Double Hip Replacement & Double Knee Replacement

Bilateral means “having or relating to two sides”. As such, a bilateral hip or knee replacement simply means having both the left and right side replaced. With a simultaneous bilateral, both replacements are done on one surgery day, during a single operation. A simultaneous double replacement allows for a single spell of prehab and rehab–which in some cases, for some patients is preferred. With a staged bilateral replacements, two surgeries are performed during two operations that are usually spaced 1-2 months apart. This is generally a better choice for elderly patients and those with a history of heart problems.

Okay, we’ve covered the differences and commonalities between the main terms that you’ll need to know. Now, it’s time to bust out a glossary of some of the other important acronyms you may come across or hear in conversation with other hippies (hip replacement recipients) or knee-anderthals (we coined this one back in 2016).

Abbreviations and Acronyms Debunked

Here are the basic, most important terms. We explained these in greater detail above.

TJRTotal Joint Replacement
TKRTotal Knee Replacement
TKATotal Knee Arthroplasty (same as total knee replacement)
PKRPartial Knee Replacement
UKAUnicompartmental Knee Arthroplasty (same as partial knee replacement)
THRTotal Hip Replacement (same as posterior hip replacement)
DAADirect Anterior Hip replacement (same as minimally invasive hip replacement)
BTHRBilateral Hip Replacement (same as double hip replacement)
BTKRBilateral Knee Replacement (same as a double knee replacement)
RRight Side (e.g. RTKR is a right total knee replacement)
LLeft Side (e.g. LTHR is a left total hip replacement)

Other Key Terms You Outta Know

OSOrthopedic Surgeon
PCPPrimary Care Physician
GPGeneral Practitioner
PAPhysician’s Assistant
OTOccupational therapist
PTPhysical Therapist (or Physical Therapy)
DJDDegenerative Joint Disease
RARheumatoid Arthritis
TTTTibial Tubercle Transfer
LRLateral Release
GAGeneral Anaesthetic
NSAIDsNonsteroidal Anti-inflammatory Drugs
ROMRange of Motion
BMIBody Mass Index
ABDAbduction (moving joint away from the centre line of the body)
ADDAdduction (moving joint towards the centre line of the body)
PreHabActively mentally, physically and environmentally preparing for scheduled surgery.
ReHabActively participating in recovery, after surgery, with a physical therapist or at home.
HEPHome Exercise Program
SNFSkilled Nursing Facility
HHAHome Health Agency
LTACHLong-Term Acute Care Hospital
IRFInpatient Rehab Facility
CJRComprehensive Joint Replacement
CMSCenters for Medicare & Medicaid Services

Okay, now you should be fluent in “hip and knee replacement”. With this knowledge, may the wind be always at your back and may the sun shine warm upon your face. Irish blessings aside, we hope that you can more confidently navigate conversations with your medical and online readings. We also hope that you can impress a few people with your newfound knowledge!

Are you getting a hip or knee replacement? Join PeerWell today and we’ll help you get set-up on our game-changing mobile PreHab app. We think you’ll love it.

Are we missing any acronyms or definitions? If so, comment below! (Rhyme intended).

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