A sensible approach to the management of patellofemoral OA

1. A sensible approach to the management of patellofemoral OA

2. Weariness about PFJ Seemingly intractable problems Variable outcome of Rx

3. Many paradoxes Quad strengthening, bike riding & swimming compress patella yet relieve PFOA symptoms Patellectomy removes source of problem yet does not relieve PFOA symptoms. Patellofemoral OA

4. No universal success story with any Rx ?PFOA a heterogeneous condition 2. PFOA + multicompartment OA 3. Isolated PFOA 1. PFOA + generalised OA

5. Isolated PFOA 1. Prevalence in knee x-rays (Davies et al. 2002) • 13.6% women, 15.4% men >60 yrs 2. Prevalence in knee pain (McAlindon et al. 1992) • 8% women, 2% men >55yrs • frequently assos with disability

6. Degenerative condition • protracted history • progressive

7. Radiological criteria (Felson et al. 1997) • Osteophytes (best correlate with knee pain -Lanyon et al. 1998) • Narrow joint space (correlates with cartilage thinning -Cicuttini et al. 2003) • Subchondral sclerosis & cysts

8. Visual criteria (arthroscopy or arthrotomy) • Exposed subchondral bone • Severe fibrillation • Surface cracks • Erbunation (?size not important for symptoms)

9. Current approaches to management • Several options • Few specific or comparative studies • Low prevalence of PFOA (McAlindon et al. 1992) • Treatments adapted from elsewhere • Treatment rationale - perceived aetiology • 2 schools: mechanical, biological

10. Abnormal loading (↑/↓ PFJ contact forces/stresses) Physicochemical damage to articular cartilage – extrinsic phenomenon Aim of treatment: Decompress joint (tibial tubercle elevation) Re-establish ‘normal’ kinematics (tibial tubercle transfer) Mechanical approach(Wiberg 1941, Outerbridge 1961, Maquet 1979)

11. Tibial tubercle elevation • Anteriorisation(Maquet 1976) • Anteromedialisation (Fulkerson et al. 1990) • ↑ patellar tendon lever arm • ↓ PFJ reaction force by 50%

12. How much elevation? • 1cm (Nakamura et al. 1985) • 2cm (Guillamon et al. 1977) Results • Variable – 30-90% (Ferguson 1982) • Overloading elsewhere (Burke & Ahmed 1980)

13. Tibial tubercle transfer • Medialisation (Trillat et al. 1964) • Distalisation (Hauser 1938) • Correction of mal-alignment • Redistribution of PFJ forces

14. lateral patello-femoral OA global patello-femoral OA medial patello-femoral OA How much transfer? • medial • inferior Results • Variable (Fulkerson et al. 1990) • Patellar baja, medial overloading (Kuroda et al. 2001)

15. Tibial tubercle surgery does not directly address the arthritis problem

16. Molecular degradation of articular cartilage (age, weight, heredity, trauma) Failure of collagen framework – intrinsic phenomenon Aim of treatment: Resurfacing (mesenchymal regeneration, cartilage grafting) Arthroplasty (PFJR v TKR debate – Laskin & van Steijn 1999) Biological approach(Chrisman, Shoji & Granda 1974)

17. Mesenchymal regeneration • Spongialisation • Drilling (Pridie 1959) • Microfracture (Stedman et al. 1997) • Neo-chondrogenesis Results • Fibrocartilage not hyaline • Variable α extent/severity

18. Cartilage grafting • Chondrocytes (Brittberg et al. 1994) • Mosaicplasty (Hangody et al. 1998) • Periosteum (O’Driscoll et al. 1988) • Articular restoration Results • Anecdotes suggest poor • Circumscribed lesions only

19. Arthroplasty • Hemiarthroplasty (McKeever 1955) • PFJR – dozen or so types on the market • Prosthetic replacement Results • Good results by enthusiasts • Limited experience • Low failure/loosening rates but tibiofemoral OA

20. Leicester prosthesis component alignment

22. Satisfaction survey Satisfied: 78.3% Not satisfied: 21.7% Patellar alignment Pre-op. Post-op. 0.3mm (+4.2) 6.4mm (+7.1) shift 0.7o (+4.4) 9.4o (+7.5) tilt Results

23. Summary of procedures • Re-align (Maquet, Fulkerson, Elmslie-Trillat) • Re-surface (chondrocyte transplantation, mosaicplasty) • Replace (unicompartmental v total)

24. α manifestations of PFOA Knee pain problems with stair climbing, kneeling & squatting Mobility & walking usually not affected 1st line Rx pain relief Non operative Arthroscopic lavage (+ lateral release – Aderinto & Cobb 2002) 2nd line Rx disability relief Tibial tubercle surgery Arthroplasty – biological v prosthetic No ‘gold’ standard – your choice

25. Minimal disability Circumscribed lesion: drilling + lateral release lavage +lateral release mosaicplasty 50 years Extensive lesion: tibial tubercle transfer PFJR or TKR Significant disability

26. Prognostic indicators for arthroscopy • Role for arthroscopy? • Controversial • Derided as placebo • Reality? • Pain relief in at least 60% for several months or years

27. Lateral release • Decompression • Impingement relief • Vastus lateralis inhibition

28. HA GAG • Nutraceuticals • 1.Glucosamine = amino sugar • (Reginster et al. 2001) • Stimulates synthesis of cartilage building proteins • Anti-inflammatory • Inhibits production of cartilage destroying enzymes • 2. Chondroitin = carbohydrate • Promotes water retention and elasticity • Anti-inflammatory • Inhibits production of cartilage destroying enzymes Gene therapy ( joint is producer of own medication eg IL-IRa, TGFβ gene) Synoviocytes Gene modification (Frisbie et al. 2002) Growth factor gene + vector (Evans & Robbins1999)