A New Classification for ”Pistol Grip Deformity”-Correlation Between the Severity of the Deformity and the Grade of Osteoarthritis of the Hip

Abstract

Using this model it is possible to differentiate between normal shapes of the head-neck junction and different severities of the pistol grip deformity.

Groin Pain in Athletes

“…Labral lesions are fostered by athletic actions (repetitive microtrauma) or isolated trauma during sports and femoroacetabular impingement arising from a poorly formed junction of the femoral head and acetabulum [40]. In the hip there is a distinction between pincer impingement when the femoral head is covered by a defective overhang of the acetabulum, and cam impingement, when the form-fit of the femoral head/neck juncture is reduced [41][42][43]. Most frequently exhibited (70 %) are combined forms and the antero-superior form of impingement with pain provocation, in particular during hip flexion and forced inner rotation and adduction [40,41].…”

Indications for Total Hip Arthroplasty in Young Adults – Idiopathic Osteoarthritis Seems To Be Overestimated

“…A value of > 1. 16 was considered to be a sign of FAI [37]. According to Murray et al, a head ratio of 1.35 was considered to be a sign of FAI.…”

“…The angle created by these two lines is called the "alpha angle" [14]. Angle values > 51°are considered to be a sign of FAI [37] ( • " Fig. 5 d).…”

“…Murray et al [16] saw the critical point of the head ratio at which a "pistolgrip deformity" should be suspected at a ratio of 1.35. 35 % presented a pathological head-neck ratio when using a value of 1.16 [37] as pathological and 25 % of all patients presented a reduced head-neck offset when using a value of 1.35 [16] as pathological. Therefore, it could be said that cam impingement is one of the main reasons for developing osteoarthritis.…”

“…According to our own findings, we declared a head ratio of > 1. 16 and an alpha angle of 51°as a sign for "pistol-grip deformity" and the resulting cam impingement [37]. Considering our data with 15 % of patients having osteonecrosis of the femoral head, 11 % high-grade dysplasia, 5.7 % Perthes' disease and nearly 60 % having dysplastic changes in the area of the femoral head neck and the acetabulum leading to an FAI, it could be said that idiopathic OA in young adults is a rare diagnosis.…”