Much research and development has been performed regarding the utilization of existing and new technology for hip arthroscopy. Intraoperative navigation systems have been developed to aid surgeons in determining the adequacy of bony resection. Traditionally, adequacy of bony resection was determined through traditional intraoperative fluoroscopy. These new intraoperative systems not only provide intraoperative feedback, but allow for the generation of post-operative reports, which can be given to patients. These systems use a combination of intra-operative images to generate a virtual three-dimensional representation of the femoral head, and calculates a live alpha angle for perfect resection.
The mainstay of treatment of femoroaceatabular impingement is correction of any underlying bony abnormality. Currently, this is performed through hip arthroscopy. A combination of burrs and shavers are used to remove excess bone and restore, as best as possible, normal anatomy. Careful attention must be paid to the labrum as well. Successful hip arthroscopy is dependent on correction of underlying CAM and pincer deformities, in addition to repair or reconstruction of labral pathology. Traditionally, proper correction of underlying bony abnormality was determined through the use of intraoperative fluoroscopy. This method, however, is quite subjective, and incomplete resection of bony pathology has been found to be a major predictor of poor outcomes following hip arthroscopy.
Femoroacetabular Impingement (FAI)
Femoroacetabular impingement (FAI) is a common cause of hip pain in young and middle-aged individuals. It is caused by an underlying anatomical abnormality which alters the normal biomechanics of the hip joint. FAI can arise from abnormalities on both the femoral and/or acetabular side of the hip joint.
On the acetabular side, an overgrowth or protrusion of the acetabular rim produces what is known as a pincer deformity. On the femoral side, excess bone on at the femoral head/neck junction procedures what is a known as a CAM deformity. These deformities can be quantified through radiography by calculating the alpha angle for CAM-type and lateral center edge angle for pincer-type. The presence of these underlying anatomical variants, when combined with repetitive squatting or internal rotation about the hip, can expose the hip labrum to abnormal stress, thus predisposing the individual to labral tears.
In addition, it has been shown that the presence of CAM FAI can lead to earlier development of osteoarthritis. 70% of the time FAI presents as a combination of pincer and CAM deformities. It is most commonly seen in sports where athletes put their hips into forced flexion and internal rotation. Prevalence and incidence in large-scale populations are not well-known yet.
The Stryker Hip Check™ is the first-ever intraoperative navigation system for hip arthroscopy performed for correction of underlying CAM-type FAI. Hip Check™ utilizes intraoperative fluoroscopy to generate side-by-side comparisons of pre and post-resection images to validate the adequacy of resection.
The images can be saved and printed and provided to patients to demonstrate just how much correction was performed. No longer do surgeons need to guess and doubt just how adequate their resection was. With Stryker Hip Check™, under or overcorrection of CAM-type deformities can become a thing of the past.