Management

 

Microfracture Awl HolesChondral Defect Post MosaicplastyAMICOCA

 

Options

 

Marrow stimulation - microfracture / microdrilling

 

Cartilage restoration

- Matrix autologous cartilage implantation (MACI)

- Autologous membrane induced chondrogenesis (AMIC)

- Autologous minced cartilage implantation (AutoCart)

- Allogenic minced juvenile cartilage implantation (DeNovo)

- Osteochondral autograft (Mosaicplasty / OAT)

- Osteochondral allograft (OCA)

 

Concept

 

Microfracture

- has traditionally been the gold standard but

- best for smaller lesions < 2 cm2

- not indicated for osteochondral lesions

- not as effective in the patellofemoral joint

- results tend to deteriorate over time

 

Cartilage restoration procedures

- indicated for

- larger lesions / osteochondral lesions / failed microfracture / young patients / athletes

- it is not clear which is the best procedure

- depends on cost / availability

 

Results

 

Long term function

 

Mithoefer et al AJSM 2009

- systematic review of microfracture

- improved knee function in 67 - 86% of patients at 6 - 7 years

 

Angele et al Cartilage 2022

- systematic review of 6 RCT with minimum 5 year follow up

- better long term outcomes with osteochondral autograft  / ACI than microfracture

 

Return to sport

 

Krych et al KSSTA 2017

- return to sport after surgical management cartilage lesions in knee

- microfracture 58%

- ACI 82%

- osteochondral allograft / OCA 88%

- osteochondral autograft / OAT 93%

 

Indications for surgery

 

Grade 3 or 4 ICRS lesions

Symptomatic

 

Knee Osteotomy

 

Indicated for any malalignment depending on knee compartment affected

 

Dhillon et al Orthop J Sports Med 2023

- systematic review of cartilage repair +/- osteotomy of the knee

- 5 studies and 1700 patients

- improved outcomes and lower reoperation rates with osteotomy patients

 

www.boneschool.com/knee/osteotomy

 

PFJ chondral lesions

 

www.boneschool.com/knee/chondromalaciapatella

 

Results

 

van Tuijn et al Cartilage 2023

- systematic review of microfracture

- worse outcomes in PFJ than in knee condyles

 

Hinckel et al AJSM 2020

- systematic review of PFJ cartilage lesions in 2000 patients

- clinical patient improvement of various restoration procedures

- MACI 83%

- OAT 78%

- OCA 71%

- AMIC 64%

- OCA had highest failure rate

 

Tibial tuberosity osteotomy (TTO)

 

Trinh et al Arthroscopy 2013

- systematic review of patients with PFJ chondral lesions

- compare isolated ACI versus combined ACI and TTO

- better outcomes with ACI / TTO

 

Marrow stimulation / Microfracture / Microdrilling

 

Microfracture Chondral Defect InitiallyMicrofracture Post PreparationMicrofracture Awl Holes

 

Principles

 

Pluripotent marrow cells produce fibrocartilage to varying degree

- low stiffness and poor wear characteristics over time

- may be more beneficial to combine with realignment procedure

 

Indications

- young patient < 40

- < 2 cm2

- chondral defect - not osteochondral defect

- contained defect - cartilage on each side of defect

- BMI < 30

 

Chondral Defet Uncontained

Uncontained lesion on intercondylar notch

 

Advantage

- simple

- able to perform in setting of unexpected cartilage lesion i.e. ACL reconstruction

 

Issue

- produces fibrocartilage

- results tend to deteriorate over time

 

Microf

Fibrocartilage response to microfracture

 

Technique

 

Debride all unstable cartilage to stable edge

- removed calcified cartilage layer with curette, protect subchondral bone

- create a perpendicular edge which helps to hold the clot

 

Microfracture Currette BaseMicrofracture Arthroscopic Awl

 

Arthroscopic microfracture awl / 1.6 mm drill

- typically 3-4 mm apart

- depth until see fat globules

 

Microfracture Awl Holes Pre SuctionMicrofracture Awl Holes Bleeding

Post arthroscopic drilling with K wire

 

Results

 

van Tuijn et al Cartilage 2023

- systematic review of microfracture

- worse outcomes with larger lesions / PFJ lesions / bipolar lesions

Kraeutler et al Orthop J Sports Med 2020

- systematic review of basic science studies

- microfracture versus microdrilling

- improved biology with microdrilling due to increased depth

- reduced damage to subchondral bone with microdrilling

 

Autologous Cartilage Implantation (ACI, MACI)

 

MACIACI

 

Principle

 

Transplant living viable cells

- capable of synthesizing and maintaining a cartilaginous matrix

- makes a substance physically and histologically similar to hyaline cartilage

 

First generation ACI - harvest periosteum to secure cells in place

Third generation M-ACI - cells presented on a matrix / membrane for implant

 

Issues

- 2 stage procedure

- significant costs

 

Technique

 

Vumedi MACI video

 

Harvest mature chondrocytes

- biopsy taken from non weight bearing area in notch or lateral edge of femoral cartilage

- cells isolated and washed

- expanded in cell culture

- attached to membrane

- process takes about six weeks

 

Implantation

- medial or lateral parapatellar approach

- create sharp stable margins

- curette base

- control bleeding with adrenalin soaked gauze to avoid graft displacement

- size defect with foil - graft cannot be prominent or will displace with ROM

- secure with fibrin glue / Tisseal

- ensure graft stability with knee range of motion

 

Results

 

Dhillon et al Arthroscopy 2022

- systematic review of MACI v microfracture

- five level I and 1 level II studies

- 500 patients

- lower failure rate and better outcomes with MACI

 

Brittberg et al AJSM 2018

- 5 year follow up of RCT of MACI v microfracture

- better outcomes with MACI at 5 years

 

Ebert et al AJSM 2024

- 10 year follow up of MACI

- 11% failure

- better outcomes with tibiofemoral graft than patellofemoral

 

Autologous Membrane Induced Chondrogenesis (AMIC)

 

Principle

 

Addition of a Type I/III collagen membrane to microfracture

 

AMICAMICAMIC

 

Technique

 

ChondrogideChondrogideTisseel

 

Surgical technique video

 

Medial or lateral parapatellar approach

- create sharp stable margins

- curette base / microdrill

- control bleeding with adrenalin soaked gauze to avoid graft displacement

- size defect with foil - graft cannot be prominent or will displace with ROM

 

Chondrogide

- porcine collagen

- bilayer collagen I/III membrane

- secure with fibrin glue / Tisseel

- ensure graft stability with knee range of motion

 

Results

 

AMICAMICAMIC

 

Volz et al Eur J Orthop Surg 2024

- 10 year follow up of RCT AMIC v microfracture

- results of microfracture deteriorated

- results of AMIC stable

 

Autologous Minced Cartilage Implantation (AutoCart)

 

Principle

 

Mechanical fragmentation of viable cartilage

- chondrocyte proliferation

- regeneration of hyaline cartilage

 

Technique

 

Vumedi autologous minced cartilage implantation video

 

Vumedi autologous minced cartilage video

 

Obtain cartilage from edge of lesion or non weight bearing areas

- intercondylar notch / periphery femoral trochlea

- can also use loose bodies / OCD lesions

- cut sharply with scapel to minimize bone death

- particles < 1 mm / have a paste like appearance

- secure with fibrin glue / Tisseel or membrane patch / Chondrogide

 

Results

 

Cole et al AJSM 2011

- RCT of microfracture versus autologous minced cartilage

- 29 patients

- better outcome with autologous minced cartilage at 2 years

 

Allograft minced juvenile cartilage implantation (DeNovo)

 

Principle

 

Donor articular cartilage from patients < 13 years

- juvenile cartilage

- may have more favorable regenerative characteristics

 

Technique

 

Denovo surgical technique PDF

 

Vumedi Denovo surgical video

 

Results

 

Clinicaltrials.gov

 

Osteochondral autograft transplantation / mosaicplasty

 

Pre MosaicplastyChondral Defect Post Mosaicplasty

 

Chondral DefectDefect debridedHarvestMosaicplasty

 

Principle

 

Autologous osteochondral bone plugs implanted in defect

- taken from low weight bearing areas of the knee

- can be associated with donor site morbidity

 

Technique

 

Vumedi mosaicplasty video

 

Debride all tissue from defect

- obtain osteochondral plugs 4.5 mm

- periphery of femoral trochlea / notch

- create cylindrical holes with drill

- insert osteochondral plug

- small gaps between plugs

- ensure slightly recessed

 

Results

 

Pareek et al Arthroscopy 2016

- systematic review of 6 studies comparing microfracture and osteochondral autograft

- better outcome scores and lower failure rates with osteochondral autograft and lesions > 3 cm2

 

Hangody et al Am J Sports Med 2010

- 354 patients followed up for average 9 years

- good results in 91% femur / 86% tibia / 74% PFJ lesions

- 5% of patients had PFJ pain from donor site

 

Gudas et al Arthroscopy 2005

- RCT of OATS v microfracture of 60 young athletes

- 93% OATS and 50% microfracture returned to sport

- results maintained in 10 year follow up study

 

Osteochondral allograft

 

Osteochondral Allograft PreOsteochondral AllograftOsteochondral Allograft Post

 

Principle

 

Indication

- very large, non contained defects

- previous failed cartilage procedures

 

Advantage

- restore anatomic contour

- nil donor site morbidity

- viable chondrocytes on fresh allograft < 30 days

 

Osteochondral Allograft PrePost Osteochondral Allograft

Pre and post OCA with HTO

 

Technique

 

ACT Allograft Technique PDF

 

ConMed ACT Allograft technique video

 

Vumedi surgical technique video

 

Use CT to get appropriate size graft

Match curvature of radius of donor site

Press fit

 

OCAOCAOCA

 

OCAOCA 2OCAOCA

 

Results

 

Wang et al Orthop J Sports Med 2023

- systematic review of OCA in 6000 patients

- mean lesion size 5 cm2

- failure rate 19%

- 83% satisfactory outcome

- survival rates at 5, 10, 15, 20, and 25 years were 94%, 87.9%, 80%, 73%, 55%, and 59.4%

 

Other options

 

Knee Hemicap AP Post OCDKnee Hemicap Lateral

Hemicap