Lonnie E. Paulos, MD Medical Director The Andrews-Paulos Research & Education Institute

1. Lonnie E. Paulos, MD Medical Director The Andrews-Paulos Research & Education Institute Gulf Breeze, FL

2. Knee Cap

3. The patella articulates with the femur…. It’s a joint Patella Sulcus Femur

4. To function properly any joint must be... Aligned (Straight) Congruent (fits together) Stable (norm ligaments) Side view Sunshine view

5. The patella-femoral joint rarely has all three The most common knee problem seen by doctors

6. The majority of people have a patella-femoral joint that is either... Mal-aligned (not straight) Incongruent (doesn’t fit) Too loose (weak ligaments) Too tight (contracted ligaments) All of the above (miserable mal-alignment) ? Mean

7. Malalignment ?

8. Determined by skeletal alignment. Develops from hip to foot (genetics) Functional alignment which requires normal muscle balance and conditioning during activities Patella-femoral alignment is

9. There is little or no consensus as to what constitutes malalignment or what treatment should be employed for symptomatic patients... The “Maligned” Patella! The result is inconsistent treatment, unpredictable outcomes and occasionallyincreased symptoms

10. Historically, Q angle has been measured with knee in extension Has never demonstrated significance ? Sulcus location (Patella-Sulcus alignment) Anterior iliac spine Lat. Med. Tibial tubercle

11. Is determined by hip, thigh, leg and foot alignment which can be measured by radiographs (CT scans) and estimated by physician examination. Patella-Sulcus Alignment

12. Computerized Axial Tomography (CT Scan) Tubercle/Sulcus Position Full extension May identify abnormalities that reduce with flexion Precise measures Distance between tibial tubercle and trochlear sulcus >9 mm indicates lateralization of tibial tubercle

13. Physical ExaminationSkeletal Alignment Hip rotation Knee valgus or varus Knee ROM Patella-Sulcus angle Foot alignment

14. Axial Alignment Knee valgus or varus Lateral insertion of patella tendon Normal  5° valgus

15. Saggital Alignment Hyper-extension 3° to 5° normal Flexion 140° to 150° normal

16. Tubercle-Sulcus Angle Flexed knee Q angle Perpendicular to transepicondylar axis Patella center to tubercle Knee flexed 90º Normal = 0º, abnl > 10º lat. Kolowich, Paulos et. al 1990 AJSM 18:359-365

17. Rotational Alignment Hip Rotation Ext. rotation  Int. rotation Hip assumes neutral position for gait so toes point forward Diff > 60° no external rotation => Abnormal • Hip Internal • Hip External

18. Rotational Alignment Thigh-foot angle Normal = 15° ext. > 30° - consider surgery

19. Foot Alignment Pronation Assoc. ext. tibial rotation and compensatory valgus

20. Incongruence ? STRUCTURAL & ARTICULAR

21. Patellofemoral Imaging Radiographs – AP, lateral, axial Computed Tomography Magnetic Resonance Imaging Helpful in evaluation, but diagnosis of subluxation or dislocation is clinical, not radiographic

22. Patellofemoral ImagingAxial Views Laurin - 20º Merchant - 45º Joint congruency Trochlear depth Lateral buttress Tilt Subluxation

23. Patellofemoral Joint Congruence Femoral sulcus shape  depth; lateral condylar height Patella shape  facet size; angle Patella height  alta; infera Alignment Growth Congruence Wyberg “Geometric restraints”

24. Articular • Grade 0: healthy cartilage • Grade 1: cartilage soft spot or blisters • Grade 2: minor tears visible in the cartilage • Grade 3: deep crevices (>50% of cartilage layer) • Grade 4: exposed bone “Chondromalacia”

25. Too Loose ?

26. Passive Laxity Determined by Ligament integrity Geometry (Congruence)

27. Patellar Glide 0º Flexion Determines Medial/Lateral Restraint 30º flexion Congruence Patellar Glide Test 3 to 4 quad glide  too loose

28. Passive Patellar Tilt Determines lateral and medial Restraints Female + 5º = +10º Male0°  + 5º  Tilt  too loose

29. Too tight Lateral Patellar Compression Syndrome (LPCS) ? • Lateral retinacular tightness – 0 or negative tilt • Lateral patella pain • Radiographic patella tilt/overhang ± • Arthroscopic lateral tracking with lateral patellofemoral wear ± NOT X-RAY Diagnosis!

30. Primary vs. Secondary LPCS Hypermobile-Lateral Tracker Time Lateral Trackers LPCS

31. All of the above ?

32. Miserable Malalignment!  Internal femoral torsion  External tibial torsion Dysplastic patella shape Dysplastic femur sulcus  T/S angle Lateral tilt  Medial glide Flat feet

34. Treatment? Accurate Evaluation Joint reaction force with congruence

35. Consensus Opinion [patella-femoral maladies] muscle strength + balance = function “envelope of function” Scott Dye

36. Compensated “Envelope of Function Excellent Bad Accident Over-use Functional Capacity Strength and Balance Dis-use Obesity Time Mild Major Limb Malalignment

37. ? Surgery [Malalignment] + [Patholaxity] + [Incongruence] Physical  [Muscle condition] + [Activity modification] Therapy Treatment

38. 1st Choice when treating P/F problems is conservative (non-surgical) treatment Usually Surgery

39. Typical Non-Surgical • Neuromuscular facilitation • Activity modification • Weight loss • Orthotics • Bracing & Taping But . . .

40. Dynamic (compensatory) Alignment Maximum Compensation Minimum Compensation

41. •Patient strides forward, one leg is lifted while full weight is on the other leg. The swing leg is subjected to rotational hip compensation, mechanical alignment, and T/S angle positioning of the tibia tubercle to the femoral sulcus just prior to heel strike. •Much like “lining up a putt” in golf, the patella is aligned with the sulcus. •At heel strike, the femur engages the patella as the hip and femur finish rotating to the mid-point between internal and external hip rotation in order to keep the foot pointed forward during the foot-flat and toe-off phases of gait. •The femoral sulcus is pre-positioned in its relationship to the tibial tubercle and actually engages the more passive patella. If this fails to occur, depending on the static and geometric restraints present, the patella will track lateral and spontaneously subluxate or dislocate during gait just prior to the foot-flat phase.

42. Quadriceps unit (mass action vector) PES anserine group (reduces T/S angle) Hip Abduction/Adduction (rotation) Dynamic Restraints?

43. Patellofemoral Joint Functional Rehabilitation • Isometrics • Straight leg raises • Leg presses (standing) • Cycle • Swim • Low impact jumping • Stretch cords • Progressive step-ups (8” max) • Increase passive hip rotation & strength! Standing Patella Forces Sitting 100° 0° Knee Flexion Angle

44. Indications for Surgery Failure of conservative care Progressive P/F arthritis with pain Recurrent subluxations / dislocations Debilitating symptoms with daily activities ?

45. Amount and type of surgery depends on the patient’s anatomy and severity of problems [malalignment] + [patholaxity] + [incongruence] ?

46. The surgeon should choose the surgical procedure with the least risk and highest chance of success based on patient anatomy Not the easiest!

47. High Risk Proximal + Distal Realignment Proximal Realignment Lateral Release Synovectomy/Chondroplasty Low Risk Procedure selected depends on age, goals, informed consent

48. Synovectomy/Chondroplasty? Pain + crepitation only Short term symptoms No instability

49. + Lateral Release ? ¤ ☼

50. Primary Indication for Isolated Lateral Release • Failed conservative treatment • A negative or neutral passive patellar tilt (LPCS) • NO or minimal instability or malalignment