What is PennHIP and How Does it Work?

PennHIP is a hip evaluation system developed by Dr. Leighton G. Condron at the University of Pennsylvania. It's a radiographic assessment that measures the hip joint's laxity and provides a more accurate prediction of hip joint health than traditional hip evaluation methods.

PennHIP uses a unique radiographic technique to take X-rays of a dog's hip joint at different angles, allowing for a more comprehensive assessment of the joint's structure and function. This results in a more accurate prediction of hip joint health and a better understanding of the potential for hip dysplasia.

The PennHIP method is based on the concept of hip joint laxity, which refers to the looseness of the joint. By measuring the laxity of the hip joint, PennHIP provides a more accurate prediction of the potential for hip dysplasia and other joint-related problems.

Intriguing read: Hip Score

PennHIP is a unique radiographic assessment that focuses on quantifying hip joint laxity to determine a dog's susceptibility to developing arthritis from hip dysplasia.

It's a set of measurements developed by the University of Pennsylvania Hip Improvement Program, which allows us to gauge the likelihood of a dog developing osteoarthritis from hip dysplasia in the future.

By catching the issue early, PennHIP screening can lead to better management and possibly some preventive measures to decrease the severity of arthritis that can develop.

The PennHIP method has its roots in a research institution. Gail Smith developed the PennHIP method at the University of Pennsylvania in 1983.

The current radiographic submission system was established in 1993. This marked a significant milestone in the evolution of PennHIP.

In the 1990s, the Penn Center for Innovation (PCI) played a crucial role in licensing PennHIP to a corporation. Smith later regained control of PennHIP in 2002.

A change in ownership occurred when PCI facilitated the sale of PennHIP to Antech Imaging Services (Antech Diagnostics, Inc.). Today, it is known as AIS PennHIP.

PennHIP is a service provided by a network of over 2000 certified veterinarians from 24 countries. It's a worldwide effort to reduce the frequency and severity of hip dysplasia in all breeds of dogs.

The PennHIP method involves taking three separate radiographs: the distraction view, the compression view, and the hip-extended view. These views are used to assess hip joint status in a unique way.

A diagnostic radiographic technique is the core of the PennHIP method, consisting of these three radiographs. It's a different approach to evaluating hip health.

Here's a breakdown of the PennHIP method's three major components:

PennHIP focuses on quantifying hip joint laxity, which allows veterinarians to determine a dog's susceptibility to developing arthritis from hip dysplasia.

The PennHIP procedure requires dogs to be under heavy sedation or anesthetized in a dorsal recumbency position to eliminate muscle tension.

Three radiographic exposures are made of the coxofemoral joint to evaluate hip quality and measure joint laxity. These exposures are made to obtain precise measurements on laxity and joint congruence.

The distraction radiograph, compression radiograph, and ventrodorsal hip-extended radiograph are the three types of radiographs used in the PennHIP procedure. The distraction device is placed between the legs in neutral position and the hips are distracted to take the radiographs.

The distraction index (DI) is a quantitative measure calculated by dividing the distance between the geometric centre of the femoral head and the geometric centre of the acetabulum by the radius of the femoral head.

PennHIP uses a unique combination of radiographs to assess hip joint health in dogs. This approach was developed by Dr. Gail Smith in the 1980s.

The diagnostic method involves three distinct types of radiographs: Hip-Extended View, Compression View, and Distraction View. These views are designed to evaluate different aspects of the hip joint.

The Hip-Extended View checks for any existing hip joint abnormalities or signs of arthritis, similar to traditional evaluations. This view helps identify any potential issues that may be present.

The Compression View evaluates how well the ball fits into the socket, known as joint congruity. This is done by pushing the dog's hip joints together during the radiograph.

The Distraction View measures the laxity of the hip joint by gently pulling the hips apart. This helps determine how loose the joint is.

The PennHIP procedure involves a series of radiographic exposures to evaluate the hip joint and detect potential issues with canine hip dysplasia. The dog must be under heavy sedation or anesthetized to eliminate muscle tension, allowing for accurate measurements.

Three radiographic exposures are made of the coxofemoral joint: distraction, compression, and ventrodorsal hip-extended radiographs. The distraction device is placed between the dog's legs in a neutral position to evaluate joint laxity.

The distraction index (DI) is a quantitative measure that calculates the maximal femoral head displacement from the acetabulum. It's calculated by dividing the distance between the geometric centre of the femoral head and the geometric centre of the acetabulum by the radius of the femoral head.

A distraction index of 0 is the tightest possible reading, while a value of 1 represents a fully luxated hip. Dogs with a distraction index of >0.4 are at an increased risk of developing hip dysplasia.

To perform PennHIP radiographs, the veterinarian and veterinary technician must complete a training program, although this is currently free. The patient must be fully anesthetized to obtain these radiographs, and three separate radiographic views are required for interpretation.

Here's a summary of the PennHIP radiographic views:

PennHIP offers several benefits for dog owners and breeders. It's accurate in puppies as young as 16 weeks, allowing for early detection and intervention.

One of the advantages of PennHIP is its predictive value. With a focus on laxity and not just existing pathology, PennHIP can help predict the likelihood of future issues.

The PennHIP technique provides quantifiable data in the form of a DI score, which offers a tangible, easy-to-interpret value that can guide treatment protocols and breeding decisions.

However, there are some drawbacks to consider. The technique can only be performed by a certified veterinarian or vet technician, who must take certain training courses and submit trial radiographs to get their certificate approved.

The cost of PennHIP is higher compared to alternatives, ranging between $200-400. Additionally, the procedure requires anesthesia.

Here's a comparison of PennHIP and OFA hip radiographs:

A 2010 study found that many dogs judged as clinically normal on OFA radiographs demonstrate laxity on PennHIP radiographs, including 52% of dogs with hips that were ranked “excellent” on OFA radiographs.