Potsdam 1 Morning Workshop
Session Type
Morning Workshop
Date
15.04.2022
Time
07:30 - 08:15
Room
Potsdam 1
Moderators
  • S. Nehrer (Krems, AT)
  • T. Minas (West Palm Beach, US)
Session Description
Experts of cartilage repair discuss various algorithms of treatment in principal and in case presentations. Different approaches of surgical treatment with pros and cons are presented.
Session Learning Objective
  1. Participants are involved in the discussion of various cases, create solutions and discuss the options with the experts in different joints and locations. Although aspects of rehabilitation and back to sports are involved.
CME Evaluation (becomes available 5 minutes after the end of the session)
Extended Abstract (for invited Faculty only) Platelet Rich Plasma and Growth factors

21.2.1 - Case Presentation 1 - Bipolar Focal Cartilage Damage to the Patellofemoral (PF) Joint

Presentation Topic
Platelet Rich Plasma and Growth factors
Date
15.04.2022
Lecture Time
07:30 - 07:45
Room
Potsdam 1
Session Type
Morning Workshop
Speaker
  • M. Steinwachs (Zürich, CH)
Authors
  • M. Steinwachs (Zürich, CH)

Abstract

Introduction

Focal cartilage damage to the patellofemoral (PF) joint often results in pain and disability. Due to the anatomical complexity of this joint, the therapeutic success after cartilage repair is often less than in other areas of the knee joint. The current case shows a patient with cartilage damage in the trochlea and on the opposite patella surface, a so-called "kissing lesion" and describes the chosen therapeutic approach.

Content

CASE HISTORY The 31-year-old patient hit his left kneecap in a bicycle fall and suffered PF cartilage damage. Intensive physiotherapy for 8 months and intra-articular corticosteroid injections failed to alleviate the pain. In addition, joint blockages and a tendency to swelling persisted. Due to severe impairment at work and sport, the patient decided to have surgery. On clinical examination he showed a slightly swollen knee with a normal range of motion, stable cruciate and collateral ligaments and symmetrical muscles and a normal leg axis in both legs.

PRE-OPERATIVE IMAGING: X-ray showed a straight leg axis. MRI showed a kissing lesion in the medial PF joint with a larger, full-thickness trochlear defect and a smaller grade II patellar defect. A modified AMIC® technique was chosen as therapy due to the patient's age, size and localization of the cartilage lesion. This included a) the recruitment of stem cells by microdrilling of the subchondral bone and the addition of platelet-rich fibrin (PRF) and b) an increase in the number of differentiated cells (chondrocytes) in the defect by loading the membrane with cartilage chips ("minced cartilage").

SURGICAL STEPS

Taking blood to obtain PRF: 60 ml of sterile venous blood was taken and centrifuged for about 30 min. The PRF was then pipetted off.

Defect preparation and cartilage harvest: A ring curette was used to remove loose and damaged cartilage tissue in the trochlear defect down to the subchondral bone plate. In order to obtain a vertical and stable defect shoulder, a small amount of cartilage was removed from the edge of the defect with a scalpel and used for the subsequent preparation of cartilage chips.

Microdrilling for recruitment of stem cells: The sclerotic bone was removed with a high-speed milling machine under water cooling and then the subchondral bone was perforated at a distance of 3 mm with a 1.6 mm K-wire to a depth of 1–1.5 cm. The opposite defect on the patella was prepared in the same way.

On arthroscopic examination, the patellar defect was larger than shown on the MRI and was therefore also treated. Cruciate ligaments, menisci, and cartilages of the tibiofemoral compartments were intact.

Prepare the Chondro-Gide® membrane: The defect shape and size was determined using an aluminum template and the membrane was cut to size when dry. A 10-15% increase in size when wet was taken into account. The membrane was then hydrated with the calcium-activated PRF.

Loading of the membrane with cartilage chips: The cartilage fragments taken from the defect edge were chopped up with a scalpel into approx. 1 mm3 large pieces and loaded onto the porous side of the hydrated membrane and fixed with fibrin glue. The loaded membrane was then soaked again with PRF.

PRF injection into the subchondral bone: The PRF was injected into the deep subchondral bone zone through the individual microdrilling channels. PRF modulates subchondral bone inflammation and stimulates stem cell migration into the defect. These are chondro-inductive, stimulate the proliferation of local chondrocytes through cell-cell interaction and thus accelerate tissue regeneration.

Implanting the loaded membrane: After applying the fibrin glue in the defect, the membrane was implanted with the loaded side facing the defect. The membrane offers the regenerate the necessary primary stability and supports the formation of new cartilage.

Fixation of the Collagen membrane: Due to the high shear stress at a corresponding PF defect, the collagen membrane was sewn into the two defects with 6-0 sutures. Finally, the edge and the sutures were sealed with fibrin glue. In the PF joint in particular, it is important to prevent the membrane from shearing out.

REHABILITATION: Initial relief on crutches and restriction of knee flexion with an orthosis. Sole contact and passive flexion up to 30° (by CPM/physiotherapist) were allowed in the first 2 weeks. Partial weight bearing and range of motion were then continuously increased and after 6 weeks full weight bearing and free movement of the knee were allowed again.

FOLLOW-UP: After three months, the patient was absolutely pain-free, could fully bear weight on the knee and move it without restriction. He showed good sensorimotor function and no apparent muscle deficit. The final 6-month MRI showed a well-integrated cartilage reconstruction in the trochlea and patella, flush with the adjacent cartilage. The subcortical bone marrow edema of the medial patellar facet had regressed and was still slightly present in the trochlear area. The T2 relaxation time was only slightly increased.

References

Levinson C, et al., Chondrocytes From Device-Minced Articular Cartilage Show Potent Outgrowth Into Fibrin and Collagen Hydrogels. Orthop J Sports Med. 2019 Sep 10;7(9):2325967119867618.

Krüger JP, et al., Human platelet-rich plasma stimulates migration and chondrogenic differentiation of human subchondral progenitor cells. J Orthop Res. 2012 Jun;30(6):845-52.

de Windt TS, et al., Direct Cell-Cell Contact with Chondrocytes Is a Key Mechanism in Multipotent Mesenchymal Stromal Cell-Mediated Chondrogenesis. Tissue Eng Part A. 2015 Oct;21(19-20):2536-47.

Kim M, et al., Extracellular vesicles mediate improved functional outcomes in engineered cartilage produced from MSC/chondrocyte cocultures. Proc Natl Acad Sci U S A. 2019 Jan 29;116(5):1569-1578.

Steinwachs MR, et al., Systematic Review and Meta-Analysis of the Clinical Evidence on the Use of Autologous Matrix-Induced Chondrogenesis in the Knee. Cartilage. 2019 Sep 11:1947603519870846.

Steinwachs MR, et al., Enhanced Cartilage Repair Technique with K-Wire Drilling Plus Subchondral Injected Plasma Rich in Growth Factors – A New Modified Microfracture Technique. J Surg. 2020; 5: 1275

Acknowledgments

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Extended Abstract (for invited Faculty only) Clinical Research

21.2.2 - Case Presentation 2

Presentation Topic
Clinical Research
Date
15.04.2022
Lecture Time
07:45 - 08:00
Room
Potsdam 1
Session Type
Morning Workshop
Speaker
  • T. Minas (West Palm Beach, US)
Authors
  • T. Minas (West Palm Beach, US)
Extended Abstract (for invited Faculty only) Clinical Research

21.2.3 - Case Presentation 3

Presentation Topic
Clinical Research
Date
15.04.2022
Lecture Time
08:00 - 08:15
Room
Potsdam 1
Session Type
Morning Workshop
Speaker
  • C. Erggelet (Zürich, CH)
Authors
  • C. Erggelet (Zürich, CH)
Extended Abstract (for invited Faculty only) Clinical Research

21.2.4 - Case Presentation 4

Presentation Topic
Clinical Research
Date
15.04.2022
Lecture Time
08:15 - 08:30
Room
Potsdam 1
Session Type
Morning Workshop
Speaker
  • S. Nehrer (Krems, AT)
Authors
  • S. Nehrer (Krems, AT)