RAPID Score for Acetabular Chondrolabral Disruption

Why did you develop the RAPID Score (Hip)? Was there a particular clinical experience or patient encounter that inspired you to create this tool for clinicians?

Our development of the RAPID Score was based on being able to provide in-clinic patient counseling and was born and statistically possible using the high volume hip arthroscopy practice at Mayo Clinic. We believe that pre-operative assessment of cartilage lesions is critical to surgical planning and decision making, however, accurate determination of acetabular cartilage damage has remained elusive for modern imaging modalities, including expensive and time consuming studies such as magnetic resonance imaging (MRI).  

The development of the RAPID Score was focused on providing benefit as a readily employable, in-clinic system for predicting high-grade cartilage damage which can be calculated and utilized on the order of seconds, using just radiographs, before the time patient may be sent (and return) from MRI and further workup. This allows us to initiate surgical discussions and the potential for various intra-operative findings both at the time of initial consultation, when some patients have yet to have an MRI, as well as at subsequent pre-operative listing appointments in light of further diagnostic workup. This information can help clinicians and patients in a variety of practices plan for high-grade damage and identify potential targets for cartilage treatment.

What pearls, pitfalls and/or tips do you have for users of the RAPID Score (Hip)? Do you know of cases when it has been applied, interpreted, or used inappropriately?

The RAPID Score has added another item to our clinical and pre-operative planning toolbox for patients undergoing evaluation for hip arthroscopy. However, we would like to highlight the continuing key role of clinical history and examination as well as additional data such as MRI in evaluating, counseling, and treating these patients. The score was developed using a general hip arthroscopy population collected over the course of 10 years of clinical practice and subsequently evaluated and validated in a previously blinded and prospective manner. However, we would like to highlight that the score was developed using patients undergoing primary hip arthroscopy, and therefore, we would caution use in complex revision cases, which fall outside of the clinical population from which this score was developed and should be interpreted.

What recommendations do you have for doctors once they have applied the RAPID Score (Hip)? Are there any adjustments or updates you would make to the score based on new data or practice changes?

Once the RAPID Score has been calculated, we recommend applying it in conjunction with clinical history, examination, and [future] intra-operative decision-making. In patients with higher RAPID Scores (4-5), we recommend surgeons have their preferred tools for managing ALAD grade 3-4 lesions (e.g. microfracture awls, cell-based therapies) listed and available at the time of surgery give the high likelihood of intra-operatively visualized delamination. Additionally, as RAPID Score increases, patients should be pre-operatively counseled on preferred high-grade lesion treatment and its potential influence on rehabilitation components, e.g. continuous passive motion (CPM) machines and time course.

In terms of updates and adjustments, we put a concentrated effort towards prospectively collecting a well-powered cohort obtained over the span of 10 years for RAPID Score generation and subsequently validating the score based on a separate, blinded and prospectively collected cohort to evaluate and demonstrate predictive value as well as provide Level I evidence in the validation group. Given this, while we do continue to evaluate our practice and the accuracy of scores, we feel that the RAPID Score is quite robust and have no current adjustments or updates.

How do you use the RAPID Score (Hip) in your own clinical practice? Can you give an example of a scenario in which you use it?

We calculate the RAPID Score on a standard basis as an additional tool for evaluating and discussing management options and shared decision making for patients presenting with labral tears and other pathology being evaluated for hip arthroscopy and preservation. While MRI continues to play a valuable role in our practice in evaluating the articular and peri-articular structures, the RAPID Score can be quickly calculated in any patient presenting with plain radiographs, prior to subsequent advanced imaging. This allows us to initiate discussion of hip preservation candidacy early on and directly involve the patients as we discuss the individual risk factors (sex, Tonnis grade, cam morphology) and show the patients how this is calculated and informs prognostication on-screen with the MDCalc website and/or mobile application. 

Special situations in which we have found the RAPID Score to be particularly helpful is prior to obtaining advanced imaging, as described above, and in patients with indeterminate MRI findings or artifacts such as those left by motion or nearby metal implants. In this case, the RAPID Score can serve to better inform nonspecific data, especially given the previously demonstrated limitations of MRI in the femoroacetabular joint and RAPID Score discriminatory values which compare favorably with previous MRI and MRA studies.

Any other research in the pipeline that you’re particularly excited about?

We have a variety of exciting projects in the pipeline, especially in our fields of focus, hip and knee arthroscopy and cartilage/joint preservation. Our RAPID and RIP scores are particular interests and have been hosted for ready graphical in-clinic use through MDCalc. We have ongoing efforts to further prospectively validate, investigate, and improve prognostication for these scores and are additionally looking into complex preservation projects including [hip] periacetabular osteotomy (PAO), and combined knee cartilage and osteotomy work.

Mario Hevesi, MD, is an orthopedic surgery resident at Mayo Clinic in Rochester, Minnesota. He is the recipient of many awards including the John Charnley award from the Hip Society, the Chitranjan S. Ranawat MD award from the Knee Society, and the Patellofemoral Anatomy and Research award from the Arthroscopy Association of North America. Dr. Hevesi’s primary research is focused on hip and cartilage preservation and regeneration.