1、The Athletic KneeShannon M.Wolfe.The Problem Young active patients with articular cartilage defects!Which defects progress to OA?Which defects are symptomatic?How do we most effectively treat these defects?.The Biology Physiologic role of articular cartilage Minimize stresses on the subchondral bone
2、 Reduces friction on the weight bearing surface Critical in proper joint function.Goals of Treatment Restore integrity of load bearing surface Obtain full range of motion Obtain pain free motion Inhibit further degeneration.Treatment Considerations Age of the patient Defect size Knee stability Knee
3、alignment Level of activity.Partial Thickness Defects Articular cartilage lacks the capacity to repair structural damage Progresses when exposed to mechanical wear.Full Thickness Defects Do not heal with hyaline cartilage Healing by subchondral stimulation leads to the formation of fibrocartilage La
4、cks physiological role of hyaline cartilage Poor wear characteristics Progress to osteoarthritis.Non-Surgical Options Activity modification(decrease load)Muscle strengthening(load absorption)Bracing(selective joint unloading)Aspiration(decrease painful joint distention).Non-Surgical Options Pharmaco
5、logical Oral Non-steroidal anti-inflammatory medication Chondrotin sulfate Glucosamine Injectable Corticosteroids-decrease the inflammatory response but have no mechanical benefit Synvisc-may improve the status of the articular surface by improving chondrocyte“health”.Surgical Options Arthroscopic l
6、avage-remove debris Arthroscopic shaving-smooth surface Drilling or microfracture-create fibrocartilage scar Osteotomy-realignment to unload diseased compartment Osteochondral autograft-replace a damaged surface Autologous chondrocyte transplant-replace injured cartilage Allograft osteochondral tran
7、splantation.Arthroscopic Lavage Remove debris and inflammation mediators Temporary relief Not a definitive procedure-not curative Not normally sufficient for athletic or active patients.Arthroscopic Debridement Lavage and chondroplasty No sub-chondral stimulation May lead to improvement for up to 5
8、yrs.10-20%may become worse Debridement does nothing to promote repair Malaligned or unstable knees do poorly.Thermal Chondroplasty New procedure Requires bi-polar or ultrasonic device“Seal”the articular surface with heat Keplan L,M.D.reported no injury to the chondrocytes of the involved or peripher
9、al cartilage.“Radio-frequency energy appears to be safe for use on articular surface.”Arthroscopy,Jan-Feb.2000,pp 2-5.Abrasion Arthroplasty Debridement and stimulation of subchondral bone 1-1.5mm deep results in fibrocartilage repair intracortical rather than cancellous.Results:Abrasion Arthroplasty
10、 Johnson 399 patients 66%with continued pain 99%with activity restriction.Results:Abrasion Arthroplasty Unpredictable May not be better than debridement alone Rand noted 50%of patients who had an abrasion underwent TKR within 3 yrs.Drilling or Microfracture Debride lose cartilage Subchondral bone pe
11、netration drill or pick,3/cm squared Results in fibrocartilage repair Lacks durability Lacks the mechanical properties of hyaline cartilage.Drilling ResultsJoseph Tippet,M.D.62 month follow up 71%Excellent 15%Good 14%Fair/Poor.Results:Richard Steadman,M.D.reported improvement in 364 of 485 patients(
12、75%)at 7 years post-op 90-100%of the defects were healed at 4 wks.with 30%hyaline cartilage 12 mos.42%hyaline cartilage Myron Spector,M.D.demonstrated complete filling of the lesions at 3 months in an animal model.Microfracture Results:Unpublished75%improvement50%returned to sports Steadman/Hawkins.
13、Osteochondral Grafting Autologous plugs of bone with hyaline cartilage cap Best done for small lesions(2cm.)New technique Limited data at follow-up.Osteochondral Autografting Indications Full thickness(grade IV)lesions in the weight bearing surface of the femoral condyles Well circumscribed lesion-s
14、harp transition zone 2 cm diameter lesion Young patient(55-60 poor results despite other inclusion criteria.Osteochondral Autografting Contraindications Lesions 2cm.(rare)Osteochondritis dessicans Large OCD usually exceed donor area limitations&large bony defects w/no subchondral reference points.Os
15、teochondral Autografting Advantages Potential for physiologic hyaline cartilage Single stage procedure Can be done all arthroscopically.Osteochondral Autografting Disadvantages/Concerns Damage to the subchondral plate Creates bleeding and fibrocartilage Donor site morbidity Incongruence of the plugs
16、/articular surface.Donor Site Morbidity:Osteochondral Autografts Morgan,Carter&Bobic 104 cases-no donor morbidity.Osteochondral AutograftBiopsy Proven Survival:Hyaline Cartilage,Tidemark&Bone Wilson 10 years Outerbridge 9 years Hangody 5 years Bobic 3 years Morgan 1 year.Osteochondral Autografting:R
17、esults Bobic 12 Cases Lesion 1-2.2cm.10/12 excellent results at 2 yrs.Osteochondral Autografting:Results Morgan&Carter 52 Cases IKDC evaluation Pain 65%improved 2 grades 31%improved 1 grade 4%no change(failure).LIMITATIONS OF OATS Potential for DJD at donor site is real No clinical support for repai
18、r of single or multiple plugsProphylactic surgery Difficult to justify the procedure.ALL TEN SITES OF OSTEOCHONDRAL HARVEST Articulated and demonstrated significant contact pressure Rim stress concentration may lead to DJD Osteochondral donor sites do not heal normally.Osteochondral Autograft Post-o
19、p Early motion Immediate active,active assisted,and passive ROM NWB x 2 weeks Thigh muscle strengthening&stretching 3 months Avoidance of sports&running for 3 months.RECOVERY FROM OATS Allow 6 weeks for plug to heal Desk job RTW 1-2 weeks Laborer RTW 3-4 months.Autologous Chondrocyte Implantation Fi
20、rst procedure:biopsy Arthroscopic chondrocyte harvest from upper medial femoral condyle Cultivation of cells 14-21 days Second procedure:implantation Arthrotomy&debridement of lesion Defect covered with periosteal flap Cultured chondrocytes injected into defect.First Surgery-Arthroscopy.Second Surge
21、ry-Arthrotomy.Inject$10,000 worth of cells!.Autologous Chondrocyte Implantation:Indications Age 15-55 Defect location femoral condyle Defect size 1-10cm.Defect type Grade IV Ligament stability Biomechanical alignment.Autologous Chondrocyte Implantation Contraindications Kissing lesions Inflammitory
22、arthritis Total meniscectomy Over 50(psychologic)Unstable knee Generalized degenerative disease Unhealed lesion through subchondral bone.Dedifferentiation/Redifferentiation.Method of Restoration.Autologous Chondrocyte Implantation:Advantages Less donor site morbidity Larger and multiple defects can
23、be addressed Good results with longer follow-up No violation of hosts subchondral plate FDA approved.Autologous Chondrocyte Implantation:Disadvantages Requires 2 procedures Not arthroscopic Expensive No long term results.Autologous Chondrocyte Implantation Post-op CPM Active ROM Toe touch weight bea
24、ring for 6 weeks week 7-12 closed chair exercises Jogging at 6 months Sports at 1 year.Autologous Chondrocyte ImplantationUS Clinical Experience 121 patients 6 month follow-up 42 patients 12 month follow-up 85%improved overall condition 80%improved pain scores at 12 months.Autologous Chondrocyte Imp
25、lantationSwedish Results NESM 1994 23 patients 14-48 Defects 1.6-6.5cm 14/16 Good excellent results with 2 year follow-up Biopsy has appearance of hyaline cartilage.Autologous Chondrocyte ImplantationSwedish Results 1997 100 patients 2-9 year follow-up 90%improvement with femoral condyle lesions 74%
26、with femoral condyle and ACL reconstruction 58%for trochlear lesions 75%for multiple defects.LIMITATIONS OF ACI Little proof that$10,000 worth of cells do anything Cartilage that regrows is not normal Ideal patient is rare Young,isolated lesion,no meniscal tear or instability Difficult to justify pr
27、ocedure.Osteochondral Allograft Transplantation Joint resurfacing with fresh or fresh frozen cadeveric tissue.Allograft Procedure Open procedure Expose the degenerative lesion Remove the defective articular cartilage and a“thin”bony base Utilize allograft tissue to replace and restore the articular
28、surface.Allograft Advantages Replaces articular hyaline cartilage with hyaline cartilage Single procedure.Allograft Disadvantages Cost Risk of disease transmission from fresh allograft tissue.Allograft Results.What to do?.Treatment Recommendations Low demand patients Small focal lesion(2cm)Arthrosco
29、pic chondroplasty 50%relief up to 5 years Autograft Osteochondral or chondrocyte if failed chondroplasty.Treatment Recommendations High demand patient Small focal lesion(2cm)Debridement or microfracture with chondrocyte harvest If persistent pain-osteochondral or chondrocyte transplant.Treatment Rec
30、ommendations High demand patients Large lesion(2cm.)Chondrocyte transplant 1st line treatment yields 90%success.Long HistoryNo Acute SymptomsVarus KneeMarked DJDArthroscopic ResultsUnpredictableLittle Improvement.Conclusions Articular cartilage does not repair itself Numerous treatments with varying
31、 results Most treatments fail in the long term due to articular cartilages inability to produce hyaline cartilage.Conclusions Osteochondral auto grafts and chondrocyte transplants show promising results Osteochondral auto grafts allow transplantation of bone capped with hyaline cartilage Autologous
32、chondrocyte implantation allows near normal hyaline cartilage growth into defects.Meniscal Allograft Indications Patient age-young-20-40 Previous meniscectomy Painful compartment Minimal Arthritic Changes Correct alignment Stable knee.Sterilization Viral contamination risk 1:1.6 million to 1:1.2 billion Radiation 2.5 mrads destroys collagen 2 yr.follow-up 11(16%)failures 70%of patients had subjective improvements with pain.Cryo-Life 5 Year Results Lateral(10)5(5%)intact 4(40%)partial meniscectomy 1(10%)total meniscectomy.
