Patellofemoral Pain Syndrome / How can a Sesamoid Bone Anterior Pain / Runners’ Knee cause So Many Problems? _ n Most common cause of Patellofemoral Pain and Patella Instability n Most common symptom presenting to SM n Diagnostic challenge n Treatment controversies n Lack of evidence to support Sarah Kerslake BPHTY Ax and Rx

PFPS Patellofemoral Anatomy n Multifactorial Etiology n Considering the PF joint is one of the most n Non-operative treatment is successful highly loaded joints in the human body, the prevalence of AKP is not surprising. n Strong evidence supports treatment with multimodal therapy n Anatomy: n Sesamoid bone in extensor apparatus n Routine clinical Ax of muscle strength in athletes may not detect deficits n Acts as pulley/cam in extensor mechanism n Protects the tibiofemoral joint n More challenging functional tests required n Anchored by Active and Passive elements

PFPS Anatomy PFPS Anatomy n Active (Dynamic) restraints n Passive (Static) restraints n Quadriceps muscle n Bony anatomy (Facets <=> Trochlea)

n Vastus Lateralis Obliquus/Longus n Quadriceps Fascia + Patellar Tendon n Rectus Femoris + Vastus Intermedius n Lateral Peripatellar Retinaculum

n Vastus Medialis Obliquus/Longus n Medial Peripatellar Retinaculum, particularly n Patella Tendon the medial patellofemoral ligament n Iliotibial band n Balance between structures is v. important

1 PFPS Symptoms PFPS Pathology n Symptoms include pain, swelling, n Patellar Tracking weakness, instability, mechanical n Patellar symptoms & functional impairment n n Pain results from loading the PF n Osgood-Schlatter joint, i.e. climbing up/down stairs, n Sinding-Larsen-Johansson squatting, kneeling, and prolonged n flexion of the knee joint n Plica Syndrome n Intrapatellar Fat Pad Syndrome

PFPS Pathology Patient History n Chondral Cartilage Pathology n Pain vs Instability, or Both? n Osteochondritis Dessicans n Onset - trauma or insidious onset, +/- dislocation or instability, or overuse n Stress Fractures n Location n Trauma n Character - ache, burn, crepitus / click, sharp, n Bipartite Patella throb intermittent / prolonged n Patellar Instability n Aggravating factors - stairs, “movie theatre” n Neuromuscular Dysfunction n Swelling - none, local, or global

Patellofemoral Evaluation Patellofemoral Evaluation n “A comprehensive knee, hip, n Functional testing of athletes with AKP has and lower extremity demonstrated decreased performance on evaluation including vertical jumping, anteromedial lunge, step- assessment of alignment, down, single-leg press, and balance and range of motion, lower limb reach tests. and core strength, and n Research has not definitively concluded if functional movement patterns this lower functional strength capacity is a should be completed” risk factor for, or result of, the condition.

2 Patellofemoral Screening Ax Patellofemoral Functional Ax

n Knee Extensor Strength n Single Leg Squat n Hip Abductor/IR/ER Strength n Controlled n Quadriceps Muscle Length n Well- aligned n Assess depth of squat, dynamic valgus, side flexion of trunk, and pain

Patellofemoral Functional Ax Patellofemoral Functional Ax n Hop Down / Single Leg Landing n Balance n Patient stands on one leg and then n On BOSU ball or foam hops off ≥20cm step and lands block, patient balances 15+cm in front of step for up to 30secs n Assess quality of movement, and n Compare movement evidence of dynamic valgus, hip quality, ROM outside drop, or rotation due to poor gluteal BOS, dynamic valgus, hip and/or core strength, lateral flexion drop or rotation, lateral of trunk, etc trunk flexion, etc.

Patellofemoral Functional Ax Patellofemoral Treatment

n Active Hip Extension n Relative Rest / Envelope of Function

n Patient instructed to lift leg 5–10 cm off bed n Loss of homeostasis of tissues about the knee while lying prone. Palpate gluteal and n Control Inflammation hamstring muscle activation; ideally gluteals n Cryotherapy ✔ should fire first. n Anti-inflammatories / Analgesics (Topical NSAID✔, n Assess for excessive motion, lumbar lordosis or short-course of medication)

to achieve lift, altered timing of hamstrings n Platelet rich plasma / Hyaluronic acid and gluteal firing, and hip or trunk flexion n Acupuncture ✔ / Dry Needling

n US/TENS/Laser

3 Patellofemoral Treatment Patellofemoral Treatment n Improve Lower Extremity Biomechanics n The treatments for AKP are numerous but

n Patellar Taping (✔ for pain management) lack evidence for their use, owing to

n Patellofemoral Bracing insufficient research quality

n Foot Orthotics n It must be borne in mind that a lack of

n Stretching ✔ quality evidence for specific treatments is

n Strengthening ✔ not proof that these treatments are

n Daily exercise program: 2 - 4 sets of 10+ ineffective repetitions over ≤ 6 weeks

Patellofemoral Treatment Patellofemoral Instability n Each patient will present with unique n 5.8/100,000 but 30/100,000 under 19 symptoms and predisposing factors years (Fithian 2004) n With improving evidence, it will become n Up to 77/100,000 in military recruits (Hsaio increasingly more straightforward to tailor 2010, Sillanpaa 2008) treatments unique to each athlete n >50% of first time dislocations è recurrent n Until such times, the use of best clinical n ≈75% of patients suffer ongoing knee pain judgment and application of available EBM n ≈90% of patients suffer chondral damage

Why does the Patella Dislocate? Anatomy of the MPFL

n Patella

n Superior half of the n “There exists no evidence that any amount medial border of the of malalignment will cause dislocation patella unless the passive stabilizers are n Femur damaged.” Davis and Fithian 2002 n Inserts in the saddle between the adductor tubercle and the medial epicondyle

4 Biomechanics of the MPFL Factors Associated with PI

n Acts as a passive leash to lateral n Anatomic translation of the patella n Femur / tibia rotational abnormalities n Valgus alignment n Functions in the first 30 degrees of flexion n High Q angle n Anisometric n Multiple n Passively ‘longest’ or ‘tightest’ at 30 degrees n Patella alta n Trochlear dysplasia n Loosens with flexion n Torn/stretched MPFL n Immature physes

Factors Associated with PI What do we need to know??

n Neuromuscular n Injury mechanism n Chronic VMO insufficiency/weakness n Degree of instability n Altered timing of quadriceps activation n Anatomic predisposition n Transient inadequate neuromuscular control n Positive J-sign n Tissue quality n Neuromuscular control, core strength n Alignment issues n Bony anatomy n Is arthrosis a big issue?

Defining the Patient Population WARPS

n Strong n Weak n Weak n Traumatic n Atraumatic n Atraumatic n Anatomy Normal n Risky Anatomy n Risky Anatomy n Instability n Pain n Pain n Dislocation n Subluxation n Subluxation

5 STAID Neuromuscular Control n Strong n Alignment n One – Legged n Traumatic Squat n Anatomy Normal n Hip and Core Strength n Instability n Balance n Dislocation

Tissue Quality Q-Angle n Multiple n Q Angle ASIS to centre Ligamentous Laxity patella to tibial tubercle n Beighton Score n Range 8-17 degrees n Number of n Leg at 0, 30, 90°? Dislocations n Quads relaxed or n Degree of lateral contracted? Laxity n Lateral moment acting on patella

Q-Angle “J” Sign n Intra-rater Reliability (7 studies) n Knee fully extended n ICC ranges from 0.22-1.0 n Patient actively flexes knee n Inter-rater Reliability n Examiner observes for n ICC ranges from 0.17-0.83 exaggerated lateral to medial n Criterion Validity translation of the patella into n Disagreement the trochlear groove n Critical Appraisal n ?Tight lateral / weak medial n Poor quality studies (Smith 2008) structures or ?anatomy

6 Single Leg Squat Diagnostic Imaging n Poor neuromuscular control n AP n Abnormal bony anatomy n Weight bearing PA views (30 degrees) n Dynamic J-sign n Skyline views n Multifactorial n True lateral at 30 degrees

n Patellar height n Trochlear Dysplasia

n Patellar tilt n Arthritis

Imaging – Trochlear Dysplasia Imaging n Crossing Sign (DuJour) n CT/MRI

n TT-TG >20mm n Osirix n MRI n Newer sequences improving assessment of cartilage

n Osteochondral defects, bone bruises, torn MPFL

Imaging Degree of Pain and/or Instability n Good Intra-Observer Reliability (>0.70) n Predominant presenting symptom instability

n tibial tubercle-trochlear groove (TT-TG) or pain (or both) n the sulcus angle n Chronic instability or degenerative disease n patellotrochlear index; Insall and Salvati methods n Subluxation or Dislocation n the congruence angle n Constant or Occasional n lateral patellar displacement n n patellar morphology Controlled by Bracing n Laxity testing – at 0 and 30 degrees

7 Physical Exam Physical Exam

n Rotational Alignment n Translation

n Hip Internal/External Rotation n 0 degrees - endpoint n Apparent torsion n 30 degrees - laxity n Palpation for tenderness n Apprehension n Check Ligaments n Jumpers n Physiologic n Patella Alta n “Don’t touch me” n Tilt

Prehabilitation Prehabilitation n Goal = ↑ strength ↓ symptoms n Home Program n EMS = adaptation of muscle fibers n Electrical Muscle Stimulation n PT treatment – often is either not specific or n Phase 1 - knee-centric

too challenging for the patient’s strength n Phase 2 - hip-centric n EMS Research: greater strength and muscle n Daily mass recovery at 3/12 post-op; improved n At least 6 weeks knee extension strength, improved function (Hasegawa et al 2011, Avramidis et al 2010)

Rehabilitation Rehabilitation

n Same for MPFL-I and n Protocol Phases MPFL-R n 1. Early Post-Operative (1-4 wks) n Therapist guided n 2. Quads activation and Core stability n EMS (4-12 wks) n Phases based on n 3. Strength and Control (6-26 wks) goals not time n 4. Sport readiness (3–9 months) n Patients are very variable

8 Resources

n www.banffsportmed.ca

n Prehabilitation and Rehabilitation Protocols available under “Your Injury” then Knee, Shoulder or Osteoarthritis headings

n Patient education videos available under Osteoarthritis section and Knee: anterior cruciate ligament.

n Information about clinics, booking appointments and referral information also available.

9