Meniscus TransplantsKevin R. Stone, MD

Ann W. Walgenbach, RNNP Wendy S. Adelson, MS

Jonathan R. Pelsis, MHS

Stone Research FoundationSan Francisco

The Aging Knee

Pediatric Normal Adult OA Adult

The Knee Joint

Meniscus

• Key shock absorber in the knee

• Torn 1.5M times annually US

• Minimal healing– No spontaneous

regeneration template

• Loss of meniscus cartilage leads to:• Increased forces across the knee joint• Increased risk of articular cartilage damage• Pain and arthritis in many cases

• Painful arthritic joints:• Rough surfaces• Harsh, degradative environment

The Problem

• Reduce pain and improve function

• Preserve the biology of the knee

• Restore a biomechanically favorable environment

• Provide a buffer to prevent bone-on-bone contact and pain

The Goal

Meniscus Transplantation: Indications

Traditional thought: Meniscus Transplantation does not work in arthritic knees (Noyes & Barber-Westin 1995, Stollsteimer 2000, Rath 2001)

Current thought: Meniscus Transplantation does work in arthritic knees if damaged articular cartilage is treated as well (van Arkel 2002, Noyes 2004, Verdonk 2005, Cole 2006, Stone 2006, Farr 2007, Rue 2008)

Supporting Studies: Sizing

• 148 heights and weights compared to MRI meniscus size

Pearson’s Correlations (r):

Height vs Total Tibial Plateau (TTP) r = 0.7194

Weight vs TTP r = 0.5470

TTP vs Medial and Lateral Meniscal Width r = 0.7386, r = 0.7209

TTP vs Medial and Lateral Meniscal Length r = 0.7040, r = 0.7209

Stone KR, Freyer A, Turek T, Walgenbach AW, Wadhwa S, Crues J. Meniscal sizing based on gender, height, and weight. Arthroscopy 2007;23-5:503-8

Meniscal Sizing Based on Gender, Height, and Weight

The Three-Tunnel TechniqueReplacing the Meniscus

Stone KR, Walgenbach AW. “Meniscal Allografting: the Three-Tunnel Technique.” Arthroscopy – The Journal of Arthroscopic and Related Surgery. 2003, 19(4):426-30.

Articular Cartilage Paste Graft Procedure

Step 1

Step 5Step 4

Step 3Step 2

Meniscus Transplantation

• 225 performed since 1997

• Clinical Exam + Patient Reported Subjective Outcome (1, 2, 3, 5, 7, 10, 15+ yrs)

• IKDC

• WOMAC

• TEGNER

Current Study:

Long-Term Survival of Concurrent Meniscus Allograft Transplantation

and Articular Cartilage Repair: A Prospective 12-Year Follow-Up Evaluation

Pre-Allograft Transplant in placeTransplantation

OB IV

Study Design

Study Inclusion

• Irreparable injury of the meniscus

Or

• Loss of the meniscus

– More than 50%

• OB III/IV

• ROM ≥ 90°

Study Exclusion

• Rheumatoid Arthritis

• Tri-compartment arthritis

• Total loss of joint space

• Simultaneous med/lat meniscus allograft transplantation

Patient Selection

• Young patients with cartilage loss and pain

• Older patients with cartilage loss and focal pain who want to remain athletic and delay or avoid a knee arthroplasty.

• “Doc, isn’t there a shock absorber you can put in my knee?”

Surgical Technique• Medial Meniscus Allograft

Transplantation: Performed utilizing periosteum, but not bone blocks, at the meniscus horns.

• Lateral Meniscus Allograft Transplantation: Preformed by preserving the bony block between the horns and inserting it into a bone trough.

• 119 Meniscus Allograft Transplant Cases

• Mean age = 46.9 years (14.1 – 73.2 yrs)

• Mean follow-up = 5.8 years (2.1 mo – 12.3 yrs)

• 118 patients ≥ 3 months from injury to time of surgery (Mean = 14.2 years)

Patient Population of Study

Patient Population (N = 119)

Neutral / Varus / Valgus

Moderate ( 5 – 7°) / Severe ( > 7°)

Grade III / Grade IV

Medial / Lateral

Male / Female

None / Mild–Moderate / Severe

(Kellgren-Lawrence)

Results

• Procedure failure: Removal of allograft without revision (N = 7), or progression to knee arthroplasty [N = 18 (TKA or UNI)].

• 94/119 allograft cases successful (79%)– Of 25 failures, Mean time-to-failure:

4.65 ± 2.99 years

– Range: 2.1 months – 10.37 years

• Kaplan-Meier estimated mean survival time was 9.93 ± 0.40 years [95%CI: 9.14,10.72]

• 13 patients were lost to follow-up

Complications

• 4 Early Postoperative Infections– 3 Deep (1 Staphphylococcus Aures, 2 negative

serologies)– 1 Superficial (Staphylococcus Epidemis)

• All cases were treated arthroscopically with irrigation and debridement and IV antibiotics.

• All cases resolved, but one deep infection case ultimately failed, with the allograft being removed 12.5 months later.

Subsequent Surgeries

Primary Procedure

Subsequent Surgeries

1st

N = 62

2nd

N = 21

3rd

N = 10

4th

N = 2

Meniscus Allograft Revision 2 4 1 –Meniscus Allograft Repair 12 1 2 –Meniscectomy 22 9 1 –Microfracture /Articular Cartilage Paste Grafting 4 – 1 1

Chondroplasty / Debridement 20 6 4 1Other 2 1 1 –

Kaplan-Meier Survival AnalysisIn Patients OB III/IV

• Time-to-failure analysis with continuous enrollment over 12-yrs

• Takes into account remaining patients (still intact / lost to follow-up (N=13))

Intact/Lost To Follow-Up

94%92% 84% 79% 67%

Cox Proportional Hazards ModelWhat is it?

• A Cox model provides an estimate of a

variable’s effect on survival after

adjustment for other explanatory variables.

• In addition, it allows us to estimate the

hazard (or risk) of procedure failure, given

their prognostic variables.

What factors affect survival?• Cox Proportional Hazards Model was used

to explore the relationship between procedure failure and several covariates.

Age (p = 0.026)

Number of Previous Surgeries (p = 0.006)

Number of Additional Surgeries

Osteotomy performed concomitantly

Number of concomitant procedures

Outerbridge Grade (III or IV)

Medial v. Lateral Allograft

Joint Space Narrowing

Malalignment Severity

Alignment Type

Sex

NOT RELATEDRELATED

Cox Model - Related Hazards

• Independent of actual time-to-failure, increased number of previous surgeries (p = 0.026) and increased age at time of surgery (p = 0.006) increases the risk of meniscus allograft transplantation failure.

Effect of Age• 53 patients over 50 (Mean = 56 yrs)

– KM mean survival = 8.84 years [95% CI: 7.51,10.17]

– 71.7% (38/53) Success Rate1 allograft removed 2 mo. post-op

14 progressed to Joint Arthroplasty @ mean 5.1 years

• 66 patients under 50 (Mean = 39 yrs)– KM mean survival = 10.67 years [95% CI: 9.76,11.58]

– 84.8% (56/66) Success Rate6 allografts removed @ mean 4.0 years

4 Progressed to Joint Arthroplasty @ mean 5.2 years

Medial v. Lateral Transplants

Non Significant Hazard (p = 0.848)

Medial

(N = 85)

KM mean survival: 9.91 ± 0.46 years

Lateral

(N = 34)

KM mean survival:

10.17 ± 0.78 years

Malalignment

• Severity of Mal-Alignment (p = 0.535)

– Severe Malalignment (>7º) (N = 10)

– Moderate Malalignment (5 – 7º) (N = 39)

7 Osteotomies– 71.4% Success Rate (5/7)– 2 UNI

3 NO Osteotomy– 66.7% Success Rate (2/3)– 1 UNI

– 50% Success Rate (4/8)– 2 TKA, 1 UNI, 1 Removed

8 Osteotomies– 80.6% Success Rate (25/31)– 2 TKA, 2 UNI, 2 Removed

31 NO Osteotomy

Patient Example: BK

• 27 year old male• Torn lateral meniscus in high school wrestling 1996• Partial lateral meniscectomy 2/96, 8/04

Pre-Operative X-Rays

BK: Pre-Op MRI

• MRI documents degenerative changes to LTP and loss of lateral meniscus

Patient Example: BK

• Lateral Meniscus Transplantation

Patient Example: BK 8 months post

• Arthroscopy for suprapatellar pouch and anterolateral swelling

• Lateral meniscus allograft transplant had healed

BK MRI 4 Years Post Op

•Lateral meniscus allograft appears normal and well positioned

•Patient reports no pain - “It feels really good”

Patient Example: JL

• 35 Year Old Female

Right Knee • 1984 - Lateral

Meniscectomy• 1988 - Lateral release• 2003 - Knee locked, total

meniscectomy• Valgus Alignment

Patient Example: JL

OB III/IV far-posterior aspect LFC, Microfracture LFC

JL: 4 months Post-Op

• Flexion contracture, debridement, closed manipulation, notchplasty

• No evidence of meniscal impingement

• Healed, intact lateral meniscus

JL: 6 years Post-Op

• Lateral Meniscus repair, chondroplasty, debridement, notchplasty

Patient Example: JA

• 37 Year old female

• Meniscectomy at age 20

• R-Lateral Meniscus missing

• OB III chondral defect

• Microfracture, Chondroplasty LFC

Long-Leg AP

JA: Preoperative X-ray

LateralAP

JA: Preoperative MRI

Lateral meniscus:• Absent posterior horn

Articular Cartilage:• Chondral damage

to LFC

JA Operative Images

A B CDeficient Lateral

MeniscusChondral Lesion of

LFCMicrofracture of

Lesion

JA Operative Images

A B CAbsent Meniscus Lateral Meniscus

TransplantTransplant Placement

JA: 5 Months Post-Op

Full Range of Motion with smooth articulation

JA: 2Yr Postoperative X-ray

PA Flexion AP

JA: 2yr Post-operative MRI

• Healed lateral meniscal allograft

JA: 5Yr Postoperative X-Ray

PA Flexion AP

JA: 5Yr Postoperative MRI

• Virtually unchanged meniscal allograft

Patient Example: GC

7o varus L-knee

Medial joint space narrowing

Active 53 y.o. male.

Meniscectomy: 1986, 1996

Medial meniscus-allograft 3/99

Paste Graft MFC & MTP

High medial tibial osteotomy (Bionx wedge and allograft bone)

GC: Preoperative Images

Sagittal MRI

Loss of cartilage MFC

PA Flexion

Medial joint space narrowing

GC: Operative Images

A BBipolar lesions Morselization of MFC & MTP

Loss of medial meniscus

GC: Operative Images

A B CPlacement of medial

meniscal allograftImpaction ofpaste graft

Paste GraftedLesion

GC: Postoperative X-Ray

Long-leg AP

GC: 3yr Postoperative X-ray

APLong-leg

GC: 3Yr Postoperative Images

3 Years post-op L-medial allograft, osteotomy, & paste graft

GC: Comparison of healing

3-Years post-op allograft and paste graft to MFC

Operative 3 yrs Post-op 3 yrs Post-op

Patient Example DB

• 47 YO Male Skier

• R Knee: Chronic Pain

• Moderate to Severe Bilateral Pain

DB: Right Knee

Right Knee:

• 09/91: Medial Meniscectomy, Drilling MFC, Chondroplasty

• 12/97: (triple) Medial Meniscus Allograft, Osteotomy, Art Cart MFC, MFx LFC

• 05/98: Revision Osteotomy, Medial Meniscectomy, Debridement, MFx MTP

• 10/2000: Ilizarov, Meniscectomy, ChondroplastyPre-Op XRAY

DB: Right Knee 10 Yr PostOp MRI

DB: 10 Yr Post Op XRAY

DB: 10 Yr PostOp

63 YO, Tegner = 6, Skis 30+ days/yr, Snow skis 50+ days/yr.

• 47 YO Female

• Beach volleyball injury (11/03)

• Failed debridement (11/03)

• Clinical exam:– Pain at rest = 8/10– Severe swelling – Giving way

• Meniscus Allograft, ACL reconstruction, Chondroplasty (3/05)

Patient Example: RT

RT: Pre-Operative MRI

Torn medial meniscus

MFC chondral lesion

LFC chondral lesion Torn ACL

Patient Example: RT

Medial meniscus Allograft Allograft Insertion

Allograft placement ACL BTB allograft

Patient Example: RT

• Intact meniscus transplant• ACL hardware removal due to prominence of fixation screw

RT: 3 Months Post

Excellent joint space, intact meniscus allograft and ACL, but right knee clicking and catching

RT: 18 Months Post

Intact meniscus allograft and ACL with diffuse thinning of patellofemoral cartilage

RT: 18 Months Post

• Surgery for catching due to chondral flap at patellofemoral joint

• Intact meniscus allograft and ACL

RT: 18 Months Post

Conclusions

• Height and weight can be used to size meniscal allograft tissue.

• Three-tunnel Technique is necessary to fix meniscus allograft to tibial plateau, not the surrounding tissue, to avoid meniscus subluxation

• Improvements are maintained over the course of follow-up (2 – 12 yrs).