Orthopaedic hip complaints in football

Rien Heijboer,

orthopaedic department

Erasmus MC Rotterdam

growth of the proximal femur

Struijs et al, Acta Orthopaedica 2011; 82 (3): 507

the apophyseal-epiphyseal coalescence

evolution of pelvis and hip joint

“Coxa recta is an aspherical femoral head, which may be seen in

running and jumping mammals, in human terms a CAM hip…”

Tom Hogervorst, Bone & Joint 2012

coxa recta

coxa rotunda

coxa recta

19 yrs old

“FAI may lead to early degenerative changes if left untreated”

Femoroacetabular Impingement, A Cause for Osteoarthritis of the Hip

Reinhold Ganz et al

CLIN.ORTH. AND REL. RES. 417, pp. 112–120, 2003

a new diagnosis

cam impingement

Abnormal contact femur-acetabulum

Damage labrum / cartilage[1]

Pain

Loss of function

OA

[1]Nepple, J.J.,et al., Clinical and Radiographic Predictors of Intra-articular Hip Disease in Arthroscopy. Am J Sports Med.

cam avoidance gait: symphysis/SI pain

21 yrs, 200m athlete

SPECT-CT

Large CAM = early THP

Pincer “protects “ against OA

Hips with both an alpha angle >83° and decreased internal rotation ≤20°

had a 53% risk of developing end-stage OA within 5 years

Agricola R et al: Cam impingement causes osteoarthritis of the hip:

A nationwide prospective cohort study (CHECK).

Ann Rheum Dis 2012; Jun 23

causes of impingement

CAM impingement

Pincer impingement

normal

etiology cam

Etiology unknown

Frequent finding (Hack et al. JBJS 2010)

female: 0-15% male :15-25% (Leunig et al. OA&C 2013, Arth Care Res 2010)

Visible from the age of 13 (Agricola et al. AJSM 2012)

Strongly associated with high impact sports

(Agricola et al. Nature rev rheum 2013, Siebenrock et al. CORR 2011)

No longitudinal studies

the risk of high impact sports

“Recent evidence also suggests that cam deformities

are more common in adolescents who participate in high-impact

sports and, thus, may be acquired during skeletal maturation”

Kapron et al: Radiographic prevalence of femoroacetabular

impingement in collegiate football players: AAOS Exhibit

Selection. J Bone Joint Surg Am 2011; 93(19):e111(1-1

Siebenrock KA et al: The cam-type deformity of the proximal

femur arises in childhood in response to vigorous sporting activity.

Clin Orthop Relat Res 2011;469(11):3229-3240.

deformity caused by sport ?

JBJS 53 B, 1971 More tilt deformity in sporting adolescents

Hypothesis

Growth + Sport = Tilt deformity

Tilt deformity + Sport = CAM impingement

CAM impingement + Sport = OA

normaal tilt cam

Feyenoord study (Rintje Agricola)

Baseline: 89 soccer players Follow-up: 63 soccer players (71%)

12-19 years at baseline; mean follow-up time 2.44 years

Three X-rays (AP pelvis & frog-leg lateral)

Quantification cam deformity:

alpha angle, visual scores

Radiographic parameters:

neck shaft angle, growth plate extension

Clinical parameter

Internal hip rotation

α-hoek (Notzli et al. JBJS 2012)

α-angle = 45° α-angle = 89°

visual score system

1. Normal 2. Flattening 3. Prominence

Increase in prevalence and size cam

Prominence

7.1% to

22.2%

P<0.001

Flattening

13.6% to

50.0%

P=0.002

Prominence

6.2% to

27.1%

P=0.19

Prominence

14.7% to

35.3%

P=0.074

Prominence

2.1% to

17.7%

P=0.002

Prominence

23.3% to

36.7%

P=0.19

Additional and predicting parameters

Besides the cam deformity (AA>60°)

↓ NSA (129.1° vs 133.6°, p=0.001)

↑ Epiphysis coalescence (1.54 vs 1.43, p=0.001)

Correlation with alpha angle r=0.81

↓ Internal rotation (20.6° vs 26.1°, p=0.009)

Predictor of cam (AA>60°)

Of 80 hips in 15 appeared a cam

Restricted internal rotation (OR=0.90, p=0.009)

Smaller NSA (OR=0.82, p=0.015)

finite element analysis

FE model of the proximal femur: open vs closed growth disc

Analysis of bone growth:

Pressure delays growth, tension accelerates growth

(Hueter-Volkmann’s law)

Dependant on biologic and mechanic components

Peak force 1200 N (250% BW)

Measured during walking, in internal and external rotation and flexion

walking int rotation ext rotation flexion

is flexion/external rotation the movement at risk?

Bone adaptation during growth

14 year 12 year

resorption

apposition

baseline 2 years later

differential diagnosis FAI

acetabular retroversion, focal overcoverage

prof soccer, 19 yrs: restricted internal rotation and abduction right hip

Audenaert, E et al Am J Sports Med 2012

The overall risk for early abutment between the femur and acetabulum

depends on both local (cam morphology) and general anatomical

conditions (femoral anteversion and acetabular coverage).

best definition

pre-operative imaging

Clinical Graphics

3D print

MRI-arthro

CT

Take home

A CAM deformity is a developmental deformity caused by alterations

of the growth plate by high impact loading

Painful and restricted internal rotation is an alarming physical finding.

Impingement is not always caused by the CAM deformity but there

may be a contribution of the femoral anteversion and/or acetabulum

overcoverage

The short term results of impingement surgery are good, but there is

no evidence yet that it can prevent OA.

There is no indication for preventive surgery (syst review,AJSM 2013)

thank you for your attention