JOINT AND BONE PRESERVING SURGERY OF THE HIP

1. JOINT AND BONE PRESERVING SURGERY OF THE HIP B. Deheshi, M.D. P. Kim, M.D. Montreal, Quebec June 19, 20 SYNOPSIS

2. Berne: Etiology of Hip Arthritis • Femoro-Acetabular Impingement • Mechanism for OA in non-dysplastic hip • Cartilage and labral lesions at acetabular rim • Due to abnormalities of prox femur, acetabulum, or supra-physiologic ROM • Early surgical intervention may decelerate degenerative process • Anterior femoral neck “cheilectomy” • Repair labral lesions acetabulum • Bernese peri-acetabular osteotomy

3. Femoro-Acetabular Impingement • Physical • ROM: Decreased IR • Impingement test • Flex, Adduct, IR (anterior rim) • Hyperextend, abduct, ER (posterior rim) • Radiographic • Herniation pit on femoral neck • Lateral and distal to former growth plate • Possible rim # (antero-superior acetabulum) • MRI • Labral tears • Contre-coup (postero-medial) joint narrowing and bony edema w possible posterior shift of head

4. FAI

5. Dysplastic Hip Evaluation • Physical • ROM: Increased IR before arthritic changes • Excessive anteversion of femoral neck • Decreased IR indicated degenerative changes • Impingement test • Apprehension test • Supine, hip extended, adducted, ER • Discomfort if anterior uncovering of femoral head • Anteversion femoral neck, retroversion acetabulum

6. Dysplastic Hip Evaluation • Radiographic • Shenton’s line discontinuity • Acetabular rim fracture • Joint space narrowing • Center-edge angle of Wiberg N>25o • Acetabular Version – Crossover sign • Abduction view • Coverage, Adequate joint space, Congruency essential pre-requisies for rotational osteotomy

7. Cross-over Sign

8. MRI in Hip Pain • Labral tears, Joint line narrowing, AVN changes • Indirect findings of pathology • Effusion, paralabral cysts, subchondral cysts • Gadolinium arthrography and MRI • More sensitive: 8% false negative rate • 20% False positive • May inject bupivicane (clinical improvement indicated intra-articular pathology)

9. Labral Tear, FAI

10. Intracapsular #s of Prox Femur • Dr. Schemitsch’s Approach • Based on physiological age (ie.activity level, cognitive level etc.) • <65 y.o. ORIF • 65-75 y.o. Grey Zone Depends on Displacement, Functional level • >75 y.o. Garden I/II – ORIF Garden III/IV - Arthroplasty

11. Intracapsular #s of Prox Femur • Literature • Cemented hemiarthroplasty better than uncemented • Lo (CORR, 1994), Khan (Injury, 2002) • Unipolar vs Bipolar: No difference • Ong (Trauma, 2002) • AVN risk after ORIF of displaced fem neck #s • 11% @ 2 yrs, 22% @ 8 yrs • Asnis (JBJS, 1994) • Early vs Delayed Reduction of Displaced fem neck #s • No Difference • Jain (JBJS, 2002)

12. Outcome of Post Wall #s • High percentage of long term good-excellent results • Radiographic results do not correlate with clinical outcome • Risk factors for poor outcome • Gap Width > 10mm • Superior and Posterior Gaps • Delay >12 h to reduction (increased AVN risk) • Age > 55 • Extensive comminution • Complete return to pre-injury functional level uncommon

13. Hip Pain-Medical Management • Non-pharmacologic Rx • Pharmacologic Rx • Tylenol 1st • NSAIDS, short term only • Cox-2 Inhibitors • Opioids – chronic pain, consult specialist • Others: Glucosamine, Chondroitin-Sulfate, Nitric Oxide inhibitors • Jury still out

14. Viscosupplementation • Prospective case series of 25 joints • NS lavage @ 1 wk, Hylan @ wks 2,3,4 • Outcome: AAOS lower limb score, Pain score • Conclusion: success rate 84 % • Negative prognostic factors • Severe O.A., Femoral head edema!, <3/5 hip flexor • Plan for multi-center trial (also prospective cohort) • My bias: • Low numbers • No control group • Reported cases of accelerated O.A., Gout, severe inflammatory reaction post-injection

15. New Millenium DVT Prophylaxis • Dr. Rodger’s recommendations • LMWH at least 2 wks post-op • Lowest published rates of DVT, PE compared to coumadin, Aspirin • Hot Topic • Surgeon #1 concern: Post-op Hematoma • Hematologist #1 concern: DVT prevention • Coumadin more popular South of the border • Certain surgeons do NOT use anticoagulation • Parts of Britain use Aspirin only • No demonstrable reduction in DVT by venography in literature w Aspirin

16. BMP • BMP in Arthroplasty • Enhances bone ingrowth of cementless acetabular components • Enhances fusion of strut allograft to cortical bone (Actual x-ray demonstration!) • Treatment of osteolytic defects • BMP in AVN • AAA bone graft • Antigen extracted, autolyzed, allograft • Useds as graft after core decompression

17. THR Survival in Young Patients • Durability of THR less in younger patients • <60 y.o. • 15-20 y. revision rates range from 10-50% in various studies • M-M resurfacing risk factors for loosening: • Poor bone quality, cysts • Greater AVN involvement • Lighter weight • Prior surgery • Smaller Head size • Activity level was NOT a risk factor

18. Meeting Patient Expectations • Patient original expectations change after arthroplasty • Pre op and 1 yr post op questionnaires revealed different expectations • Important to clarify reasons for THA pre-op • Understand patient’s expectations • Explain possible outcomes and limitations Bottom Line Patient must understand that THA improves function, relieves most of pain, but is NOT the same as Native hip.

19. Imaging Labral Tears • Intra-artic Gad MRI • 90% sensitivie for labral lesions • 30% sensitivity witout Gad • Labral tears and associated findings • Oblique tears • Broad bucket handle tears • Complex tears (intra-substance contrast uptake) • Para-labral cyst formation • Abnormal femoreal neck-acetabular offset • Synovial herniation pit anterior femoral neck (FAI)

20. Imaging Cartilage Lesions • More challenging • Less sensitive • Higher false positive rate w surface irregularity / narrowing • Location • Antero-superior most common • Poster-superior 2nd • Delamination from subchondral bone • AbN Gad signal deep to low intenity cartilage layer • Most commonly anterosuperior (extension of labral tear) • “inverted oreo cookie” • Best seen on Sag or coronal

21. Hip Arthroscopy • Most common Dx • Labral pathology • Debride damage tissue, create stable transition zone • No efficacy of repair • Chondral damage • Excision/chondroplasty • Microfracture (PWB 10 wks post-op) • Lig teres disruption • Debride damaged portion only • Loose bodies • Remove or debride

22. Hip Arthroscopy • Most common Dx • Impinging osteophytes • Rarely benefit from excision in degenerative setting • Excise in acute setting causing early impingement • Synovial disease • RA, synovial chondromatosis, PVNS • Focal – localized to pulvinar, neural “fat pad” of hip • Diffuse – synovial lining of capsule • Rx - synovectomy

23. Labral Tear: Arthroscopic vs Open • Excellent results of both arthroscopy and arthrotomy • Arthrotomy advantage • Adequate excision and smoothing of associated articular cartilage flap

24. Dx and Outcome in Hip Arthroscopy • Good results • Labral pathology • Late sequelae of Legg-Calve-Perthes • Loose bodies • Poor result predictors • Severe pain • Degnerative joint disease • No mechanical symptoms

25. Bernese Peri-acetabular Osteotomy

26. Bernese Peri-acetabular Osteotomy • Pre-requisites • Congruent hip joint • No femoral head deformity • No proximal femoral angular deformity • May require prox femoral osteotomy • Adequate coverage w abduction

27. Proximal Femoral Osteotomies

28. Proximal Femoral Osteotomies • Adult sequelae of DDH • Varus, possible shortening, de-rotation osteotomy • AVN • Varus/Valgus osteotomy depending on lesion site • Flexion component with anterior involvement • Low success rate with >50% head involvement • Abduction hinge impingement from Perthes • Valgus osteotomy to prevent impingement of sup femoral osteophye w lateral margin of acetabulum • Non-union femoral neck fractures • Valgus intertrochanteric osteotomy

29. Surgical Dislocation: Boston experience • Indications (relative) • Femoral head fracture • Acetabular fracture • Osteonecrosis • Legg-Calve-Perthes disease • SCFE • Femoro-acetabular impingement • Femoral head tumors (eg. chondroblastoma) • Multiple hereditary exostoses

30. Surgical Dislocation: Boston experience • Contraindications (relative) • Adequacy of less morbid procedures (eg. arthrostcopy, femoral osteotomy) • Traumatic labral tear w/out assoc bony deformity • Femoral deformity without assoc intra-articular pathology

31. Surgical Dislocation: Boston experience • Surgical complications (49 patients) • 1 Femoral neck non-union • neck osteotomy in mature SCFE • 2 AVN • IT osteotomy and osteoplasty in skeletally immature SCFE • Valgus osteotomy for femoral neck non-union • 1 Wound hematoma

32. Hip Arthrodesis • Indications • <40 y.o • Active male, heavy labor • Non-inflammatory, mono-articular hip arthritis • Post-traumatic, Quiescent septic, AVN • Contraindications • Absolute • Ipsilateral knee, contralateral hip, lumbar arthrosis • Relative • Advanced age, poor condition, marked obesity, poor psyche • Recommended technique • Double plating

33. Cementless Metaphyseal Anchorage Hip • In Europe, Anything Goes!

34. Minimally Invasive THA • Two-incision technique • Fluoroscopic guidance • Contraindications: • Abnormal anatomy eg. DDH • Extensive scar tissue from previous surgery • Osteoporosis necessitating cemented stem

35. Minimally Invasive THA • Results • Discharge time • 80% one day • 10% two days • 10% four days • Complications (51 hips) • 1 proximal femur # • 11 lateral femoral cutaneous n. injuries (incomplete) • 1 revision for loose stem due to fracture

36. AVN: French Approach • Bone Progenitor cells • AVN patients have lower number of bone progenitor cells in uninvolved parts of femoral head than healthy adults • Core decompression alone therefore limited • Bone marrow cells instead of vascularized or cancellous graft (Stage I & II disease) • Method • Harvest from anterior iliac crest • Concentrated in laboratory • Reinjected into necrotic zone during core decompression

37. Free Vascularized Fibular Graft • 80% 10 year success rate • E. Harvey (Montreal) • Contraindications • Sickle cell disease • Continuous use of steroids or alcohol • Age >40 y.o. • Acetabular arthrosis

38. Free Vascularized Fibular Graft

39. Cartilage of Ficat III & IV AVN • Post-collapse cartilage studies in laboratory • Significant degeneration • Poor mechanical properties • No additional weakness compared to osteoarthritic cartilage • No relationship between ON grade or size and mechanical or histological properties

40. Prognostic Factors in AVN • Good prognostic factors for success of non-arthroplasty options • Early stages • Smaller lesions • Young age • Co-morbidities controlled • Poor prognostic factors • Femoral head collapse • Acetabular involvement • Active co-morbidities

41. Europe!

42. Surface Arthroplasty (L.A.)

43. Surface Arthroplasty (L.A.) • 400 hips M-M SA, Mean age 48 (15-77) • Results • Majority returned to high level activity • 4 year survival rate 94.4% • Revisions: • 0.75% femoral neck fractures • 2.25% femoral loosenings • 0.25% acetabular protrusio • 0.25% infection • 0.25% recurrent subluxation

44. Surface Arthroplasty (L.A.) • Loosening risk factors: • Large femoral cyst (>1cm) • Height (tall) • Female gender • Smaller component size • No metallosis • No measurable wear

45. Surface Arthroplasty: Birmingham Experience

46. Surface Arthroplasty: Birmingham Experience • Over 2000 Metal-Metal resurfacings • (D. McMinn, Birmigham) • Results • 97% 7-year survival • Good to excellent reported • Majority back to full activities • Complications • 4 femoral neck fractures • 2 AVN • 3 infections • 1 dislocation • 2 post-operative deaths

47. Birmingham Patients

48. Tribologic Considerations

49. Tribologic Considerations • Heat treatment and wear • Heat treatment used in solution annealing, hot isostatic pressing or sintering of porous material • Leads to increased wear of cast cobalt-based alloys (controversial) in vitro • In vivo correlation not demonstrated yet • Head diameter • Boundary lubrication setting – larger head leads to more wear • Elastohydrodynamic (ehl) lubrication setting – larger head responsible for lubrication film, so less wear

50. Optimal Design for M-M Surface Arthroplasty • Sustaining fluid film lubrication crucial • Polar bearing system • Effective radial clearance = cup radius (larger) minus femoral head radius (smaller) • Ideal setting is high effective radial clearance • Lower wear