Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Filter by Categories
Arthroscopic Techniques
Case Report
Current Issue
Elbow, Review Article
Foot and Ankle, Review Article
Guest Editorial
Hip, Review Article
Knee, Review Article
Letter to the Editor
Original Article
Regenerative Orthopaedics, Review Article
Review Article
Shoulder, Review Article
Spine, Review Article
Video of Arthroscopic Surgical Procedures
Wrist, Review Article
View/Download PDF

Translate this page into:

Case Report

Autologous chondrocyte implantation for huge patellar cartilage defect

Department of Arthroscopy and Sports Medicine, Manipal Hospital, Bengaluru, Karnataka, India
Corresponding author: Krunal Soni, Department of Arthroscopy and Sports Medicine, Manipal Hospital, Bengaluru, Karnataka, India.
This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, transform, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.

How to cite this article: Soni K, Nayak S. Autologous chondrocyte implantation for huge patellar cartilage defect. J Arthrosc Surg Sports Med doi: 10.25259/JASSM_35_2021


Autologous chondrocyte implantation (ACI) is associated with excellent long-term outcomes for isolated patellar chondral defects. A 24-year-old male with a history of road traffic accident 1 month back presented with locking of the knee. An MRI was done which revealed a full-thickness patellar cartilage defect measuring 1.5 × 2 cm with a loose body measuring the same size. Pre-operative planning and evaluation were done and the patient was posted for a two-stage ACI procedure. Staged post-operative rehabilitation protocol was followed. Annual outcome scale included the short form-36, modified Cincinnati activity score, and Knee Society Score and the patient reported excellent scores in all three outcomes scales at 2 years. Magnetic resonance imaging was done at 2 years for detailed analysis of the cartilage repair using Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. The patient’s MOCART score demonstrated complete fill of the defect, integration to the border, no hypertrophy, and no effusion.


Outerbridge classification
Autologous chondrocyte implantation
Modified Cincinnati activity score
Knee Society Score
Magnetic Resonance Observation of Cartilage Repair Tissue score


Patellar chondral injuries are common in road traffic accidents and high-velocity sports injuries. Chondral defects measuring more than 0.9 cm2 are biomechanically unstable[1] with the tendency to degenerate and onset of early osteoarthritic changes.[2,3]

Cartilage restoration techniques such as microfracture, osteochondral autograft, and autologous chondrocyte implantation (ACI) can be employed for the management of patellar chondral injuries.[3] Microfracture provides good short-term results; however, long-term results are not favorable.[4] Similarly, as emphasized by Bentley et al.,[5] osteochondral autograft is associated with poor outcomes in patellar chondral injuries.

Recently, ACI is demonstrating promising results in patellar chondral injuries,[6-8] especially in isolated patellar cartilage defect Grade 3 or 4[9] as per Outerbridge classification larger than 2 cm2.


History and evaluation

A 24-year-old male athlete presented with complaints of anterior left knee pain for 1 month and a history of the left knee injury due to a road traffic accident 1 month back. On clinical examination, mild left knee effusion presents, occasional locking of knee presents, and ligaments normal. On further evaluation, MRI was suggestive of full-thickness cartilage defect in interfacetal and medial facet patella measuring 1.5 × 2 cm categorized as Grade 3 as per Outerbridge classification [Figure 1a and b].

Figure 1:: (a) MRI sagittal section demonstrating patellar chondral defect (black arrow). (b) MRI axial section demonstrating medial and interfacetal patellar chondral defect (black arrow).

Surgical planning

After thorough clinical and MRI evaluation, the anesthetic assessment was done and the patient was posted for two-stage ACI.


Stage 1 ACI

After spinal anesthesia, the patient was positioned supine with a thigh tourniquet with a side post on the thigh and a post for 90° knee flexion. Standard anterolateral and anteromedial knee portals were made, and initially, a loose body measuring 1.5 × 2 cm [Figure 2a] was found anteriorly in the knee joint which was removed [Figure 2b], a corresponding defect was noted on the patellar articular cartilage in interfacetal and medial facet which was thoroughly debrided to stable and healthy margin and a biopsy taken from lateral femoral condyle [Figure 2c] and send to the laboratory.

Figure 2:: (a) Arthroscopic view loose body in the left knee joint. (b) Patellar articular cartilage measuring 1.5 ×2 cm. (c) Biopsy from lateral non-weight-bearing surface of lateral femoral condyle.

Stage 2 ACI

Six weeks after Stage 1 ACI, the patient was posted for Stage 2 ACI. After spinal anesthesia, the patient was positioned supine with a thigh tourniquet with a side post on the thigh and a post for 90° knee flexion. Midline incision was taken. Medial parapatellar knee arthrotomy was done and the patella was mobilized and everted for better visualization. Curettage of defect done. Periosteal membrane harvested from distal femur microsutured flush to defect and sealed with Tisseel fibrin glue (TISSEEL [Fibrin Sealant] Pre-filled PRIMA Syringe [Frozen], 2 mL) circumferentially to ensure water tightness. Autologous cultured chondrocytes (CARTIGROW, Cell Processing Center™, Lonavala, Maharashtra, India) were implanted beneath the membrane to fill the defect injected beneath the membrane.

On the closure of arthrotomy, patellar tracking was good and no additional bony or soft-tissue procedure was done. Postoperatively – Standard 3 phase physiotherapy protocol followed.


On final up at 2 years, the patient had an excellent outcome with no pain, full range of motion [Figure 3], and return to sports. Magnetic resonance imaging was performed with a Philips Medical Systems Achieva 1.5 Tesla unit, using a SENSE knee coil (phased array coil with eight elements) at 2 years post-operative. Magnetic Resonance Observation of Cartilage Repair Tissue score was used for the assessment of the ACI which demonstrated complete fill of the defect, integration to the border, no hypertrophy, and no effusion.

Figure 3:: (a-d) Clinically squatting, forward lunging, and knee range of motion.


Autologous chondrocyte implantation (ACI) is a promising treatment modality for young patients with huge patellar chondral defects. ACI has good midterm outcome. However more long term follow up data is required before any strong conclusions can be made.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


  1. , , , . Osteochondral defects in the human knee: Influence of defect size on cartilage rim stress and load redistribution to surrounding cartilage. Am J Sports Med. 2004;32:1451-8.
    [CrossRef] [PubMed] [Google Scholar]
  2. , , , , , . Association of cartilage defects with loss of knee cartilage in healthy, middle-age adults: A prospective study. Arthritis Rheum. 2005;52:2033-9.
    [CrossRef] [PubMed] [Google Scholar]
  3. , , , , , , et al. The natural history of cartilage defects in people with knee osteoarthritis. Osteoarthritis Cartilage. 2008;16:337-42.
    [CrossRef] [PubMed] [Google Scholar]
  4. , , , , , , et al. Results after microfracture of full-thickness chondral defects in different compartments in the knee. Osteoarthritis Cartilage. 2006;14:1119-25.
    [CrossRef] [PubMed] [Google Scholar]
  5. , , , , , , et al. A prospective, randomised comparison of autologous chondrocyte implantation versus mosaicplasty for osteochondral defects in the knee. J Bone Joint Surg Br. 2003;85:223-30.
    [CrossRef] [PubMed] [Google Scholar]
  6. , , , , , , et al. Autologous chondrocyte implantation in the patella: A multicenter experience. Am J Sports Med. 2014;42:1074-81.
    [CrossRef] [PubMed] [Google Scholar]
  7. , , , , , . Fresh osteochondral allograft transplantation for isolated patellar cartilage injury. Am J Sports Med. 2015;43:879-84.
    [CrossRef] [PubMed] [Google Scholar]
  8. , , , , . Long-term results of autologous chondrocyte implantation in the knee for chronic chondral and osteochondral defects. Am J Sports Med. 2014;42:2178-83.
    [CrossRef] [PubMed] [Google Scholar]
  9. . The etiology of chondromalacia patellae. J Bone Joint Surg Br. 1961;43B:752-7.
    [CrossRef] [PubMed] [Google Scholar]
Show Sections