{"id":11246,"date":"2024-08-12T06:00:11","date_gmt":"2024-08-12T05:00:11","guid":{"rendered":"https:\/\/blogs.bmj.com\/bjsm\/?p=11246"},"modified":"2024-08-06T14:36:06","modified_gmt":"2024-08-06T13:36:06","slug":"the-msk-playbook-femoral-acetabular-impingement-syndrome","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bjsm\/2024\/08\/12\/the-msk-playbook-femoral-acetabular-impingement-syndrome\/","title":{"rendered":"The MSK Playbook – Femoral Acetabular Impingement Syndrome"},"content":{"rendered":"

Unpicking hip pain in young athletes; pincers & bump: FAI syndrome or just an athletic hip?<\/span><\/p>\n

Introduction<\/b><\/p>\n

Young athletes often complain of groin pain. When pain originates from the hip joint, clinicians refer to it as hip-joint related groin pain. Hip-joint related groin pain can cause significant time loss at a key stage of development and training in young athletes. Recent consensus statements have helped to define a framework for assessing hip-related groin pain in athletes and help sports medicine clinicians to work up, image and manage patients with \u2018Femoroacetabular Impingement (FAI) Syndrome\u2019 – one of the conditions causing hip-related groin pain. We discuss current concepts around the management of patients with FAI syndrome, and if this is just a normal bump, symptomatic pathology, and the early opportunity to detect impingement in order to prevent osteoarthritis (OA) developing in later life.\u00a0<\/span><\/p>\n

A consensus on the athlete\u2019s hip<\/b><\/p>\n

In 2016, the first international consensus statement (Warwick) was designed to help create a definition of FAI syndrome in athletes. It described the key triad of: symptoms, clinical signs and imaging findings found in athletes that are exposed to extreme repetitive physiological stresses of the hip (ball and socket joint) and soft tissues. Since then further consensus statements (Oxford, involving a much larger and more diverse expert panel), refined the Warwick consensus terminology and helped to define areas for future research in the young athletic hip. The ESSKA 2024 consensus on Hip and Groin Pain (1) built on several recent\u00a0<\/span>consensus studies (including four Zurich Consensus papers and two Oxford Consensus papers\u00a0<\/span>\u2013 see below) to cement the standard use of the term FAI syndrome, categorising it as a type of hip-joint related groin pain. There is a significant overlap between patients with changes in the shape of the hip with no pain and those that are symptomatic and need intervention. This spectrum of presentations highlights the importance of referring to the \u2018morphology\u2019 of the hip in cam\/pincer impingement, and not \u2018abnormalities\u2019 or \u2018lesions\u2019.<\/span><\/p>\n\n\n\n\n\n\n
Subtypes<\/b><\/td>\nWhat does that look like?<\/b><\/td>\nPrevalence<\/b><\/td>\n<\/tr>\n
Cam Morphology<\/b><\/p>\n

A bony bump at the junction between the ball and neck in the ball and socket joint (aspheric femoral head).<\/span><\/td>\n

\"\"<\/td>\nSome studies report cam morphology may be present in around 66% of athletes (2).<\/span><\/p>\n

Most common in young, athletic males (3), although more research is required in female athletes.<\/span><\/td>\n<\/tr>\n

Pincer Morphology<\/b><\/p>\n

A deep socket in the ball and socket joint (deep acetabulum).<\/span><\/td>\n

\"\"<\/td>\nSome studies report pincer morphology may be present in around 51% of athletes (2).<\/span><\/p>\n

Most common in middle-aged females (3).<\/span><\/td>\n<\/tr>\n

Mixed Morphology<\/b><\/p>\n

A combination of the ball and socket morphology as described above.<\/span><\/td>\n

\"\"<\/td>\nMixed morphology is reported to be present in around 57% of athletes in some studies (2).<\/span><\/p>\n

Often thought to be the most common subtype (4).<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Table 1: Subtypes of FAIS (Image source (5))<\/b><\/p>\n

\"\"<\/p>\n

Figure 1: Cam morphology compared to the contour of a pistol\u2019s grip, in reference to the now outdated term \u2018pistol grip deformity\u2019 (6).\u00a0<\/b><\/p>\n

FAI syndrome and sports participation<\/b><\/p>\n

Although our understanding of the exact relationship between hip morphology and sports participation is still developing, many studies have shown that athletes have a higher prevalence of primary cam morphology (and likely pincer morphology too) compared to the general population.<\/span><\/p>\n\n\n\n\n\n
General Population<\/b><\/td>\nCam Morphology Incidence<\/b><\/td>\nPincer Morphology Incidence<\/b><\/td>\nMixed Cam\/Pincer Morphology Incidence<\/b><\/td>\n<\/tr>\n
Symptomatic<\/span><\/td>\n17%<\/span><\/td>\n18%<\/span><\/td>\n65%<\/span><\/td>\n<\/tr>\n
Asymptomatic<\/span><\/td>\n37%<\/span><\/td>\n67%<\/span><\/td>\n36%<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Table 2: Incidence rates of FAIS subtypes in the general population (7-9)<\/b><\/p>\n

The risk of primary cam morphology (and FAI syndrome) varies by sports with higher cumulative stresses on the hip particularly during adolescent years seen as a key risk factor. Primary cam morphology is usually only seen (on x-rays, and earlier on MRI) after the age of 13 in boys (and likely earlier in girls), when closure of the growth plates starts to commence (10). Participation in academy or professional sport increases the incidence of cam morphology and symptoms (2-3x) compared to controls (11). Understanding the risk factors contributing to FAI syndrome and an awareness of how these may develop in a sportsmen\/women therefore becomes essential to the clinicians responsible for delivering education, symptomatic care and management especially in the younger population of active individuals.<\/span><\/p>\n

Sport-related factors contributing to FAI syndrome:<\/span><\/p>\n