Contralateral Allografts

Why a lateral condyle can be considered for a medial defect

The radius of curvature (ROC) is an important variable related to potential cartilage incongruities in the transplantation of a large femoral osteochondral allograft.

• It was determined that the implantation of a lateral femoral condyle donor allograft into a medial femoral condyle defect is supported.
• Looking at ROC, 20-mm defects had a 100% chance of being matched. Defects of 25 and 30 mm had a 91% and 64% chance of being matched, respectively.

LINK TO STUDY:

Differences in the Radius of Curvature Between Femoral Condyles: Implications for Osteochondral Allograft Matching. Du, Peter Z. MD; Markolf, Keith L. PhD; Levine, Benjamin D. MD; McAllister, David R. MD; Jones, Kristofer J. MD. Journal of Bone & Joint Surgery - American Volume. 100(15):1326-1331, August 1, 2018.

Condyle-specific matching may not be necessary

Rates did not differ significantly between groups when comparing the clinical outcomes of patients treated with non-orthotopic OCA with those treated with traditional orthotopic OCA.

LINK TO STUDY:

Condyle-Specific Matching Does Not Improve Midterm Clinical Outcomes of Osteochondral Allograft Transplantation in the Knee

Conventional OCA matching often prohibits timely transplantation

These matching criteria may increase the number of available matches, reduce wait times for patients, and reduce the number of wasted grafts.

LINK TO STUDY:

Osteochondral allograft donor-host matching by the femoral condyle radius of curvature. Bernstein DT, O’Neill CA, Kim RS, et al. Am J Sports Med. 2017;45(2):403-409.

Supported by the consensus of the MOCA Group

Consensus was taken among MOCA surgeons where they unanimously supported the statement: A contralateral OCA can be utilized for a single-plug restoration up to 25mm in diameter.

LINK TO STUDY:

Metrics of OsteoChondral Allografts (MOCA) Group Consensus Statements on the Use of Viable Osteochondral Allograft

Surface contour mapping of contralateral lateral femoral condyle (LFC) versus ipsilateral MFC OCAs.

There were no significant differences in subchondral bone circumferential step-off or surface deviation between ipsilateral MFC and contralateral LFC oval-shaped OCAs for 17 mm × 36 mm defects of the MFC.

LINK TO STUDY:

Subchondral Bone Alignment in Osteochondral Allograft Transplants for Large Oval Defects of the Medial Femoral Condyle: Comparison of Lateral versus Medial Femoral Condyle Donors. Kelly M.R. Taylor, Conor S. Locke, Timothy S. Mologne, William D. Bugbee, and John A. Grant. OnlineFirst. January 29, 2024.

Topography studies indicate that a lateral condyle can be used for a medial defect

OCA surface match suggests that nonorthotopic lateral femoral condyle OCAs are acceptable graft options for medial femoral condyle defects.

• Micro–computed tomography (mCT) images of the medial femoral condyle were acquired and analyzed to compare the topography of the original recipient site with the medial femoral condyle and lateral femoral condyle repaired sites. Both types of OCA— medial femoral condyle and lateral femoral condyle —matched well.

LINK TO STUDY:

Osteochondral Allograft Transplant to the Medial Femoral Condyle Using a Medial or Lateral Femoral Condyle Allograft: Is There a Difference in Graft Sources?

Analysis of topography of the opposite condyle to treat focal defects

OCAs from opposite condyles yield similar topographic matching to OCAs from the same condyles, suggesting that opposite condyles can be utilized.

LINK TO STUDY:

Topographic analysis of the distal femoral condyle articular cartilage surface: adequacy of the graft from opposite condyles of the same or different size for the osteochondral allograft transplantation. Yanke AB, Urita A, Shin JJ, et al. Cartilage. 2019;10(2):205-213.

Topographic Matching Yielded Similar Results

Ipsilateral and contralateral lateral femoral condyles provided similar articular cartilage surface and resulting subchondral bone surface matching with that of medial femoral condyles, suggesting that lateral femoral condyle allografts could be a potential source of OCA for the treatment of medial femoral condyle lesions.

LINK TO STUDY:

Topographic Matching of Osteochondral Allograft Transplantation Using Lateral Femoral Condyle for the Treatment of Medial Femoral Condyle Lesions: A Computer-Simulated Model Study. Urita A, Cvetanovich GL, Madden BT, Verma NN, Nozomu I, Cole BJ, Yanke AB. Arthroscopy. 2018;34(11):3033-3042.

No significant difference found in the mean absolute AP mismatch

Analyzing the topography of the opposite condyle to treat focal femoral condyle articular defects yields similar topographic matching to OCAs from the same condyles, suggesting that opposite condyles can be utilized.

• When evaluating the association between femoral condyle graft–recipient AP mismatch and clinical outcomes of OCA, there was no significant difference found in the mean absolute AP mismatch; thus, graft-recipient AP mismatch was not associated with midterm OCA failure rates or patient-reported outcome scores.

LINK TO STUDY:

Graft-Recipient Anteroposterior Mismatch Does Not Affect the Midterm Clinical Outcomes of Osteochondral Allograft Transplantation of the Femoral Condyle. Dean Wang, Francesca R Coxe, George C Balazs, Brenda Chang, Kristofer J Jones, Scott A Rodeo, Riley J Williams 3rd. Am J Sports Med. 2018 Aug;46(10):2441-2448. doi: 10.1177/0363546518782939. Epub 2018 Jul 9.

Contralateral OCA’s Provide Acceptable Surface Match for OCD Lesions

This paper suggests that lateral allografts can be as effective in replicating the native contour as medial allografts. The findings showed that there were no differences in cartilage step-off height or surface height between medial and lateral allografts.

• This research contributes to the growing body of knowledge that using a lateral femoral condyle is an acceptable option.

LINK TO STUDY:

Contralateral Lateral Femoral Condyle Allografts Provide an Acceptable Surface Match for OCD Lesions.

Size-matched contralateral nonorthotopic lateral condyles are acceptable for medial defects

Oblong ipsilateral medial femoral condyle OCAs and oblong contralateral nonorthotopic lateral femoral condyle OCAs produced a significantly better surface contour match to the native medial femoral condyle than overlapping circle grafts for oblong defects 17 × 36 mm in size.

LINK TO STUDY:

Osteochondral Allografts for Large Oval Defects of the Medial Femoral Condyle: A Comparison of Single Lateral Versus Medial Femoral Condyle Oval Grafts Versus 2 Overlapping Circular Grafts

Topographic Analysis of OCA’s for Oblong Lesions

Oblong medial OCA’s provide acceptable topographic matching for large oval medial femoral condyle lesions when condylar width differences are minimized. However, concern exists in using oblong lateral femoral condyle allografts for medial femoral condyle defects, as this can result in increased peripheral step-off and surface mismatch.

LINK TO STUDY:

Topographic Analysis of Lateral Versus Medial Femoral Condyle Donor Sites for Oblong Medial Femoral Condyle Lesions. Urita A, Redondo ML, Christian DR, Inoue N, Cole, BJ, Yanke AB.. Arthroscopy. 2020;36(11):2900-2908.