Abstract
Background:
Chondral injuries in the knee are commonly discovered during knee arthroscopy procedures. Due to the poor restoration potential and avascular nature of cartilage, large defects are commonly treated with such surgical procedures. Treatment utilizing an osteochondral allograft (OCA) transplant for symptomatic focal cartilage defects in the patellofemoral joint has demonstrated strong, lasting clinical and radiographic outcomes.
Indications:
Active and otherwise healthy patients are indicated for surgery when presenting with significant joint-line pain and a large focal chondral defect verified on advanced imaging after an extensive course of nonoperative management.
Technique Description:
Beginning with diagnostic arthroscopy to confirm the large defect of the medial femoral condyle, we proceeded with OCA transplantation. A small medial peripatellar arthrotomy is performed. The fat pad is removed for visualization and retractors are placed both medially and laterally to appropriately visualize the defect. The defect is then sized according to the appropriate sizing guide. The guide is then placed perpendicular to the defect, and a central guide pin is drilled. A scoring reamer is used to carefully cut the size of the defect followed by a central reamer to prepare the defect. Any debris is removed, and the incision is thoroughly irrigated. The defect is then carefully measured in all four quadrants to match the donor. Any underlying bone is impacted for a stable base. A drill is then used for appropriate marrow venting underneath the defect. The corresponding donor site is selected and reamed with continuous irrigation to prevent thermal necrosis. The plug is removed and carefully measured to match the recipient site. The plug is thoroughly irrigated with pulse lavage to remove marrow elements. The graft is carefully inserted with gentle manual pressure until it is seated perfectly flush with the surrounding cartilage.
Results:
Clinical research has demonstrated good-to-excellent long-term survivorship of OCA transplantation. Long-term return to sport rates for recreational and competitive athletes are upward of 75%.
Discussion/Conclusion:
As surgical techniques continue to develop, surgeons should consider utilizing OCA transplants to treat large chondral defects in the patellofemoral joint.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video transcript
Background
This is a surgical technique video demonstrating how to perform an osteochondral allograft (OCA) transplantation.
There are various challenges in treating cartilage lesions including their avascular nature, concomitant pathology, and treatment efficacy. 1 Management options include both surgical and non-surgical treatment.
In cases of acute onset without functional deficits, conservative treatment may be employed. When non-operative treatment fails or the lesion significantly affects function, operative treatment may be recommended.
Numerous treatment options for cartilage defects exist ranging from simple debridement to repair or restoration through transplantation. A recent study assessing return to sport relative to treatment type found autograph transplantation resulted in the highest return to sport though OCA and autologous chondrocyte implantation showed return rates above 80%. 3
Important factors when considering surgical recommendations include local, regional, and systemic pathology such as defect shape, size and depth, knee stability, and meniscal status, and overall mechanical alignment. 1 In cases of large defects, particularly those with significant subchondral bone involvement, OCA transplantation is typically recommended.
In this case, the patient presented as a 40-year-old female with progressive knee pain and swelling 2 years following an arthroscopic micro fracture of the medial femoral condyle. Pain persisted despite conservative management including therapy and injections.
Physical exam was notable for an intelligent gait with neutral mechanical alignment decreased knee flexion, and medial joint line tenderness. She was otherwise ligamentously stable. Standard knee radiographs showed no joint space narrowing or arthritis and no gross malalignment. Magnetic resonance imaging demonstrated a large focal chondral defect of the central weightbearing portion of the medial femoral condyle with significant underlying subchondral bony edema.
Given her symptomatic presentation and imaging evidence of the chondral defect that was refractory to conservative management, she was indicated for surgical management. A diagnostic knee arthroscopy was planned with anticipated cartilage restoration via OCA transplantation due to the large defect size and underlying bony involvement.
Technique Description
We typically begin with diagnostic arthroscopy to confirm defect size and shape. As this confirmed a large defect of the medial femoral condyle that matched our preoperative workup, we proceeded with OCA transplantation. A small medial peripatellar arthrotomy is performed. Fat pad is removed for visualization and retractors are placed both medially and laterally to appropriately visualize the defect. The defect is then sized according to the appropriate sizing guide. The guide is then placed perpendicular to the defect, and a central guide pin is drilled. A scoring reamer is used to carefully cut the size of the defect followed by a central reamer to prepare the defect. Any debris is removed, and the incision is thoroughly irrigated. The defect is then carefully measured in all 4 quadrants to match the donor. Any underlying bone is impacted for a stable base. A drill is then used for appropriate marrow venting underneath the defect. The corresponding donor site is selected and reamed with continuous irrigation to prevent thermal necrosis. The plug is removed and carefully measured to match the recipient site. The plug is thoroughly irrigated with pulse lavage to remove marrow elements. The graft is carefully inserted with gentle manual pressure until it is seated perfectly flush with the surrounding cartilage.
Results
A standard postoperative OCA transplantation protocol is prescribed as shown. Phase 1 focuses on patellar mobilization, early motion, and adequate protection for healing. Phase 2 builds with increased motion and closed chain strengthening. Phase 3 adds endurance training and advanced strengthening while phase 4 focuses on return to sports training. 6
Clinical research has demonstrated good-to-excellent long-term survivorship of OCA transplantation.1,2 Long-term return to sport rates for recreational and competitive athletes are upward of 75%.4,5
Thank you for watching our technique demonstration for OCA transplantation.
Footnotes
Submitted December 31, 2022; accepted January 10, 2024.
One or more of the authors has declared the following potential conflict of interest or source of funding: J.C. reports support from Arthrex, Inc, CONMED Linvatec, Ossur, and Smith & Nephew; and is a board or committee member for AOSSM, Arthroscopy Association of North America, and International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
