Imaging of the Patello-Femoral Jointmedia-ns.mghcpd.org.s3.amazonaws.com/sports2018/2018...Patella...
Transcript of Imaging of the Patello-Femoral Jointmedia-ns.mghcpd.org.s3.amazonaws.com/sports2018/2018...Patella...
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Radiographic Evaluation of the Patellofemoral Joint
R O B E RT N A S C I M E N TO , M D, M S
C H I E F O F S P O RT S M E D I C I N E & S H O U L D E R S U RG E RY
N E W TO N - W E L L ES L E Y H O S P I TA L
M E D I C A L D I R EC TO R & H EA D T EA M P H YS I C I A N , B O STO N C O L L EG E AT H L E T I C S
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Disclosures
Depuy Mitek Sports Medicine – Speaker / Education
Smith & Nephew - Consultant
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Patello-Femoral Disorders
Interlay of history, exam, and imaging studies to make a correct diagnosis
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
RadiographsFull Series◦Bilateral AP weight-
bearing
◦Bilateral PA flexion weight-bearing
◦ Lateral at 30 deg flexion
◦ 30, 60, 90 axial views
AP Detects highly abnormal patella
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Merchant View Radiographic Angles
Sulcus angle◦Abnl >140
◦Measure of trochleardepth
Congruence angle◦Normal -8 to +14
◦Measure of patellar subluxation
Normal
Bisects sulcus Intersects patella apex
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Abnormal Congruence Angle
Opens Lateral Not Medial(+ rather than – degrees)
Normal congruence angle
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Merchant View Radiographic Angles
Lateral PF angle◦Normal opens lateral and
> 8 deg
◦Abnl parallel or open medial
◦Measure of patellar tilt
Consider Laurin View◦Axial at 20 deg before
engagementNormal Abnormal
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
More patellar tilt
PF Index: measure of thickness of joint space Medial/Lateral◦ Normal value is 1.6 or less◦ Abnl > 1.6
Patellar tilt angle ◦ Relationship of lateral facet
to posterior condyles is more consistent
◦ Normal is always > 7 degrees and > 12 degrees @ 20-30 degrees of flexion
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Tilt also evaluated via MRI
Normal is 10 degrees from posterior condylar line
87% sensitivity, 88% specificity, PPV 81%, NPV 92%◦ This was matched to
patients physical exam findings
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Lateral Xray
Possibly the most useful xray
Always measure patellar height
30 degree flexed view assumes engagement into the trochlea and stabilization of the patella
Measurement of Patella alta, lateral tilt, and trochlear dysplasia from this view lateral at 30
degrees
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Patella Alta
Caton-Deschamps and Blackburne-Peele more accurate in determining height
Insall-Salvati and Grelsamer-Meadows also potential methods but may not be as accurate due to patella morphology
Patella Alta
Caton - Deschamps IndexBlackburn – Peele Index
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Normal radiographic anatomy
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Trochlear Dysplasia: Mild
Type ACrossing sign
Minimal trochlear depth
Type BRecentering beak with
flat trochlea
Abnl sulcus angle
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Trochlear Dysplasia: Severe
Type C:Hypoplasia of medial
trochlea
Double contour
Type DMost severe
Recentering beak
Double contour
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Trochelar dysplasia
Abnormal – Crossing Sign Abnormal – Double Contour Sign
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Trochelar dysplasia
Normal Abnormal
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Patella Tilt
Normal – Lateral facet Anterior to median ridge
Abnormal – Lateral facet superimposed on median ridge
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
MRI of Acute InjuryVerify dislocation
Detect osteochondral defects◦ Up to 30-40% are missed on
standard axial views◦ Rate of osteochondral fracture in
first time patellar dislocation is 24%
Locate possible loose bodies
Assess for concomitant injuries
Measure TT-TG distance◦ Schoettle showed an 86%
intermethod reliability of TT-TG measurement between CT and MRI
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
CT
Indicated in all patients undergoing patellar stabilization surgery??
Assess trochlear morphology
Assess congruence and tilt through a range of motion◦ 10 degree increments: 0-60
Accurately measure TT-TG distance
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
TT –TG distance: CT/MRI measurement of tubercle malalignment
Jones et al.2-9 mm normal10-19 abnormal> 20 mm highly abnl.
Schepsis et al.Normal up to 12Abnormal greater
than 1515-20: mild>20: significant
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Pearls to accurate measurement of TT-TG
Reference line must be perpendicular to the posterior condylar line
Use the center of the trochlea in axial views closest to the notch (distal where patellar engagement starts)
Use the center of the distal tendon attachment on the tibial tuberosity
TT-TG = 26mm
TTTG
TG
EVALUATION & TREATMENT OF THE INJURED ATHLETEADVANCED TOPICS IN SURGERY AND REHABILITATION
Thank you!!
Questions??