Risk Factors for Failure After Osteochondral Allograft Transplantation of the Knee: A Systematic Review and Exploratory Meta-analysis

Abstract

Background: Graft failure after osteochondral allograft transplantation (OCA) of the knee is a devastating outcome, often necessitating subsequent interventions. A comprehensive understanding of the risk factors for failure after OCA of the knee may provide enhanced prognostic data for the knee surgeon and facilitate more informed shared decision-making discussions before surgery. Purpose: To perform a systematic review and meta-analysis of risk factors associated with graft failure after OCA of the knee. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: The PubMed, Ovid/MEDLINE, and Cochrane databases were queried in April 2021. Data pertaining to study characteristics and risk factors associated with failure after OCA were recorded. DerSimonian-Laird binary random-effects models were constructed to quantitatively evaluate the association between risk factors and graft failure by generating effect estimates in the form of odds ratios (ORs) with 95% CIs, while mean differences (MDs) were calculated for continuous data. Qualitative analysis was performed to describe risk factors that were variably reported. Results: A total of 16 studies consisting of 1401 patients were included. The overall pooled prevalence of failure was 18.9% (range, 10%-46%). There were 44 risk factors identified, of which 9 were explored quantitatively. There was strong evidence to support that the presence of bipolar chondral defects (OR, 4.20 [95% CI, 1.17-15.08]; P = .028) and male sex (OR, 2.04 [95% CI, 1.17-3.55]; P = .012) were significant risk factors for failure after OCA. Older age (MD, 5.06 years [95% CI, 1.44-8.70]; P = .006) and greater body mass index (MD, 1.75 kg/m2 [95% CI, 0.48-3.03]; P = .007) at the time of surgery were also significant risk factors for failure after OCA. There was no statistically significant evidence to incontrovertibly support that concomitant procedures, chondral defect size, and defect location were associated with an increased risk of failure after OCA. Conclusion: Bipolar chondral defects, male sex, older age, and greater body mass index were significantly associated with an increased failure rate after OCA of the knee. No statistically significant evidence presently exists to support that chondral defect size and location or concomitant procedures are associated with an increased graft failure rate after OCA of the knee. Additional studies are needed to evaluate these associations.

Osteochondral Allografts in Knee Surgery: Narrative Review of Evidence to Date

“… 61 A more recent systematic review and meta-analysis of 16 studies totaling 1401 patients by Kunze et al found that bipolar defects of the patellofemoral or tibiofemoral articulating surfaces, male sex, older age, and greater BMI were significantly associated with an increased failure rate after OCA transplantation. 17 Chondral size defect or location, patellar defects, and concomitant procedures were not associated with increased risks of failure, which were in contrast to other studies. 17 , 24 , 61 , 63 In a retrospective study, sex mismatch between donor and recipient was associated with a 3-times greater likelihood to fail at 5 years compared to same-sex transplantation.…”

“…Contraindications for OCA transplantation include uncorrected limb malignment and/or ligamentous instability, body mass index (BMI) >35 kg/m 2 , smoking, alcohol abuse, chronic steroid use, advanced osteoarthritis within any compartment (Kellgren-Lawrence grade >2), and systematic autoimmune or inflammatory joint disease ( Table 1 ). 2 , 17 Bakay et al found in their study that all grafts with unaddressed 10°–15° varus malalignment after OCA transplantation failed in the short-term at a mean follow-up of 19 months. 18 Other groups have similarly reported that uncorrected coronal malalignment is a risk factor for failure that can result in an almost seven times higher failure rate.…”

“… 61 , 62 Rates of failure are influenced by a multitude of factors including gender, age, BMI, defect size and location, and revision cases. 17 , 61 , 63 , 64 Patient-reported outcomes are impacted by a variety of characteristics, including history of prior knee surgeries, baseline physical activity, and preoperative pain levels. 65 , 66 Interestingly, patient-reported outcomes have not been shown to be influenced by factors such as age, gender, or size of the defect.…”

“…Understanding the risk factors associated with failure after OCA transplantation is helpful for surgeons during preoperative counseling and clinical surveillance. 17 Failure of OCA transplantation can have many definitions, including subsequent revision cartilage surgery or arthroplasty, failure to achieve SCB or improvement to the level of MCID on patient-reported outcomes, or evidence of graft failure on postoperative imaging or second-look arthroscopy. In vivo mechanical failure of the transplanted graft typically occurs by osseous collapse or delamination of the articular cartilage surface ( Figure 4 ).…”

Association of Subchondral Changes With Age and Clinical Outcome in Patients With Osteochondral Fractures in the Knee: MRI Analysis at 1 to 10 Years Postoperatively

“… 1 , 7 , 18 While the provided evidence does not allow for a reliable conclusion of parameters influencing the outcome of OCF fixation, studies investigating osteochondral allograft transplantation (OCA) and osteochondral autograft transplantation have consistently reported increasing age as a risk factor for graft failure. 17 , 33 In addition, there is an unmet need for imaging studies evaluating postoperative cartilage quality and progression of disease after the fixation of OCFs.…”