Outcomes After Fresh Osteochondral Allograft Transplantation for Medium to Large Chondral Defects of the Knee

Cell-free biomimetic osteochondral scaffold for the treatment of knee articular surface lesions: Clinical outcomes differ based on patient and lesion characteristics

PURPOSE

A cell-free biomimetic osteochondral scaffold was developed to treat cartilage knee lesions, with positive clinical results documented in small case series. However, clear evidence on patient and lesion characteristics that might affect the outcome is still lacking. The aim of this study is to analyse a large cohort of patients treated with this scaffold to investigate factors that could influence the clinical outcome.

METHODS

Two hundred and three patients (mean age 30.7 ± 10.9 years) treated with this scaffold were prospectively evaluated at baseline, 6-, 12- and 24-month follow-up. The clinical outcome was analysed using the International Knee Documentation Committee (IKDC) score, and the activity level was assessed with the Tegner score. The influence of patient and lesion characteristics on clinical outcomes was analysed.

RESULTS

Mild and severe adverse reactions were found in 39.0% and 1.5% of patients, respectively. The failure rate was 2.0%, increasing to 12.3% when including also clinical failures. The IKDC subjective score increased from 43.3 ± 15.9 to 61.0 ± 16.2 at 6 months, 68.3 ± 18.5 at 12 months and 73.8 ± 18.3 at 24 months (p < 0.0005). The Tegner improved from 2.5 ± 1.7 to 4.2 ± 1.7 at 24 months (p < 0.0005), without reaching the pre-injury level (6.0 ± 2.2) (p < 0.0005). The IKDC objective score changed from 68.5% normal and nearly normal knees before the treatment to 90.1% at 24 months. At 24 months, age showed a correlation with the IKDC subjective score (ρ = -0.247; p < 0.0005), women had a lower score (p < 0.0005), as well as patients with patellar lesions (p = 0.002). Previous surgery correlated with lower results (p = 0.003), while better results were found in osteochondritis dissecans (OCD) compared to degenerative lesions (p = 0.001).

CONCLUSION

This cell-free biomimetic scaffold is a safe and effective treatment for cartilage knee lesions, offering positive clinical results at 2 years with a low failure rate. Better outcomes were observed in younger patients, in lesions of the femoral condyles and in OCD, while joints affected by patellar lesions, patients who underwent previous knee surgery, and women may expect lower results.

LEVEL OF EVIDENCE

III, Cohort study.

Fresh osteochondral allograft transplantation for knee full-thickness articular cartilage lesions using femoral head of living donors: short-term results

BACKGROUND

Fresh osteochondral allograft transplantation is a good treatment option of cartilage defects. However, this treatment option is not available in all countries due to limited graft availability and tissue banks limitations. The purpose of this study is to assess the short term functional and imaging outcomes of fresh osteochondral allograft transplantation in the knee using the femoral head of living donors.

HYPOTHESIS

Fresh osteochondral allografts from the femoral heads of living donors is a valid graft source for management of distal Femur cartilage defects. This technique can improve functional knee scores with good radiological outcomes.

STUDY DESIGN

Prospective case series.

METHODS

Fifteen patients with full thickness cartilage defects of the distal femur underwent osteochondral allograft transplantation from the femoral heads of living donors. Grafts were transplanted by both shell and multiple dowels techniques. The average follow up duration was 18.3 months (range, 12-25 months). Patients were evaluated by Lysholm and International Knee Documentation Committee (IKDC) scores, radiography and MR imaging using Osteochondral Allograft MRI Scoring System (OCAMRISS).

RESULTS

There was a statistically significant improvement (P < 0.001) in both Lysholm and IKDC average scores at 6 months and 12 months postoperative. Postoperative MRI was done at an average 6.8 months (range, 5-11 months) postoperative. The mean total OCAMRISS score was 3.4 (range, 1-7). A second look arthroscopy was done in four patients and showed intact articular cartilage in all three patients.

CONCLUSION

Femoral head of living donors is a valid new source for fresh osteochondral allograft transplantation of knee osteochondral lesions. Short term results showed improvement in clinical assessment scores. Follow up imaging showed graft incorporation and good MRI scores.

Osteochondral Allograft Transplantation in the Knee

Osteochondral injuries of the knee can be a frequent source of debilitating pain and dysfunction. Significant chondral (>1.5-2 cm2) lesions of the femoral condyles can be especially difficult to manage with nonsurgical measures. Fresh osteochondral allograft (OCA) transplantation has been shown to be a reliable surgical procedure to manage a wide array of high-grade focal chondral lesions, with or without subchondral bone involvement. OCA transplantation affords the transfer of a size-matched allograft of mature hyaline cartilage with its associated subchondral bony scaffold. Indications include primary or secondary management of large, high-grade chondral or osteochondral defects secondary to trauma, developmental malformation, osteonecrosis, or other focal degenerative disease. Contraindications include end-stage osteoarthritis, uncorrected malalignment, ligament or meniscus deficiency, and inflammatory joint disease. Improvements in surgical technique, allograft storage, and tissue availability have created more reproducible clinical results and increased chondrocyte viability. Long-term (>10 year) graft survival rates have been shown to be between 70% and 91%, and the procedure has been shown to be cost-effective based on cost per quality-adjusted life year. Finally, OCA transplantation has been shown to provide excellent return to play rate for athletes with medium-to-large cartilage lesions. OCA transplantation is therefore an important option in the treatment algorithm of articular cartilage injuries.

Surgical Treatment of Focal Chondral Lesions of the Knee in the Military Population: Current and Future Therapies

INTRODUCTION

Chondral and osteochondral defects of the knee are common injuries in the military population that have a significant impact on readiness. Definitive treatment of these injuries is challenging since cartilage has a limited capacity for self-repair and regeneration. Management is particularly challenging in military patients who maintain a higher level of activity similar to athletes. Existing surgical techniques have variable results and often long recovery times, sparking the development of several new innovative technologies to return service members back to duty more quickly and effectively after cartilage injury. The purpose of this article is to review the current and future surgical treatments for chondral and osteochondral knee lesions and their relevance in managing these injuries in the military.

METHODS

In this review article, we describe the current treatments for chondral and osteochondral defects of the knee, reporting on outcomes in military populations. We explore emerging treatment modalities for cartilage defects, reporting innovations, stage of research, and current data. Published results of each treatment option in military populations are reviewed throughout the article.

RESULTS

This review includes 12 treatments for chondral lesions. Of these therapies, four are considered synthetic and the remaining are considered regenerative solutions. Regenerative therapies tend to perform better in younger, healthier populations with robust healing capacity. Success of treatment depends on lesions and patient characteristics. Nearly all modalities currently available in the USA were successful in improving patients from presurgical function in the short (<6 months) term, but the long-term efficacy is still challenged. Upcoming technologies show promising results in clinical and animal studies that may provide alternative options desirable for the military population.

CONCLUSIONS

The current treatment options for cartilage lesions are not entirely satisfactory, usually with long recovery times and mixed results. An ideal therapy would be a single procedure that possesses the ability to enable a quick return to activity and duty, alleviate pain, provide long-term durability, and disrupt the progression of osteoarthritis. Evolving technologies for cartilage lesions are expanding beyond currently available techniques that may revolutionize the future of cartilage repair.

Timing of Outcomes and Expectations After Knee Surgery in the US Military: A Systematic Review

CONTEXT

Knee injury and subsequent surgery are widespread in the military setting. Associations between knee surgery and expected outcomes over time have not been consolidated and characterized systematically by procedure type across the body of literature, and the temporal expectations of these outcomes remain unclear.

OBJECTIVE

To summarize common postoperative follow-up times and associated outcomes that determine clinical or surgical failure in US service members after elective knee surgery.

DATA SOURCES

A systematic search was conducted with 3 bibliographic databases of published research reports from 2010 through 2021.

STUDY SELECTION

Studies in US military service members undergoing elective knee surgery, with a minimum of 1-year follow-up, and reporting on a functional/occupational outcome were included. Three reviewers screened all abstracts and full-text articles to determine eligibility.

STUDY DESIGN

Systematic review of longitudinal cohort studies.

LEVEL OF EVIDENCE

Level 2a.

DATA EXTRACTION

Extracted data included military demographics, surgical procedure variables, surveillance period, and outcome measures. The Newcastle-Ottawa Scale and the Grading of Recommendations Assessment, Development, and Evaluation approach were used to determine study quality and risk of bias.

RESULTS

A total of 22 studies (mean follow-up time of 40.7 months) met the inclusion criteria. For cruciate ligament repair, approximately one-third of patients required a second surgery or were medically separated from military service by 2 years from surgery; 100% were reinjured by 4 years, and 85% sustained a new injury within 5 years of surgery. For meniscal repair, nearly one-third of patients were medically separated, and half were placed on activity restrictions within 3 years of surgery. For articular cartilage repair, within 5 years, 39% of patients required a second surgery, 30% were placed on activity restrictions, and 36% were medically separated. For patellar repair, 37% of patients were medically separated and over half were placed on activity restrictions within 5 years.

CONCLUSION

Common knee surgeries can have long-term implications for military careers that may not become apparent with shorter follow-up periods (<2 years). When longer surveillance periods are used (eg, up to 5 years), additional surgical procedures are more common and the likelihood of being injured or medically separated from military service is higher.

Young Age and Concomitant or Prior Bony Realignment Procedures are Associated with Decreased Risk of Failure of Osteochondral Allograft Transplantation in the Knee: A Nationwide Database Study

OBJECTIVE

Osteochondral allograft (OCA) transplantation is a restorative surgical option for large, full-thickness chondral or osteochondral defects in the knee. Variability in outcomes reporting has led to a broad range of graft survival rates. Using rate of salvage surgery following OCA as a failure metric, the purpose of this study was to analyze the incidence and risk factors for failure in a nationwide cohort.

DESIGN

The M151Ortho PearlDiver database was queried for patients aged 20 to 59 who underwent primary OCA between 2010 and 2020. Patients with prior cartilage procedures or arthroplasty were excluded. Kaplan-Meier survival analysis was performed to characterize cumulative rate of salvage surgery, defined as any patient subsequently undergoing revision OCA, autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), unicompartmental knee arthroplasty (UKA), or total knee arthroplasty (TKA). Multivariable logistic regression was used to determine the effect of several variables on odds of salvage surgery.

RESULTS

Around 6,391 patients met inclusion criteria. Cumulative 5-year salvage rate was 1.71%, with 68.8% in the first 2 years. Age 20 to 29 and concomitant or prior bony realignment procedures were associated with significantly decreased rate of salvage surgery (age-adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI], 0.24-0.99, P = 0.046; realignment-aOR = 0.24, 95% CI, 0.04-0.75, P = 0.046).

CONCLUSIONS

In the largest OCA cohort studied to date, less than 2% of patients required salvage surgery. Young age and bony realignment were protective. These findings suggest that OCA in the knee is a durable cartilage-restoration procedure, especially in young patients with corrected alignment.

Knee Cartilage Lesion Management-Current Trends in Clinical Practice

Many patients, particularly those aged above 40, experience knee joint pain, which hampers both sports activities and daily living. Treating isolated chondral and osteochondral defects in the knee poses a significant clinical challenge, particularly in younger patients who are not typically recommended partial or total knee arthroplasty as alternatives. Several surgical approaches have been developed to address focal cartilage defects. The treatment strategies are characterized as palliation (e.g., chondroplasty and debridement), repair (e.g., drilling and microfracture), or restoration (e.g., autologous chondrocyte implantation, osteochondral autograft, and osteochondral allograft). This review offers an overview of the commonly employed clinical methods for treating articular cartilage defects, with a specific focus on the clinical trials conducted in the last decade. Our study reveals that, currently, no single technology fully meets the essential requirements for effective cartilage healing while remaining easily applicable during surgical procedures. Nevertheless, numerous methods are available, and the choice of treatment should consider factors such as the location and size of the cartilage lesion, patient preferences, and whether it is chondral or osteochondral in nature. Promising directions for the future include tissue engineering, stem cell therapies, and the development of pre-formed scaffolds from hyaline cartilage, offering hope for improved outcomes.

Predicting Postoperative Injury and Military Discharge Status After Knee Surgery in the US Army

BACKGROUND

Researchers have assessed postoperative injury or disability predictors in the military setting but typically focused on 1 type of surgical procedure at a time, used relatively small sample sizes, or investigated mixed cohorts with civilian populations.

PURPOSE

To identify the relationship between baseline variables and injury incidence or military discharge status in US Army soldiers after knee surgery.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from a repository containing personnel, performance, and medical records for all active-duty US Army soldiers. Multivariate logistic regressions were used to estimate the effects of numerous variables on postoperative injury or on medical discharge. Variable selection and model validation were conducted using the k-fold method.

RESULTS

A total of 7567 soldiers underwent knee surgery between 2017 and 2019. Meniscal procedures were the most common type of surgery (39%), and approximately 71% of the cohort had a postoperative injury. Significant predictors for sustaining a postoperative injury included having a previous nonknee injury (odds ratio [OR], 1.5), female sex (OR, 1.3), and Black race (OR, 1.2). Within 4 years after surgery, 17% of soldiers were discharged from the military because of knee-related disability. Significant predictors for discharge from duty included enlisted rank (OR, 2.3), recent fitness test failure (OR, 1.9), number of previous knee surgeries (OR, 1.7), and having a previous nonknee injury (OR, 1.6).

CONCLUSION

After knee surgery, nearly three-fourths of the soldiers in this cohort sustained a postoperative injury and almost one-fifth of soldiers were medically discharged from the military within 4 years. This study identified variables that indicate statistically increased risk for these postoperative outcomes and highlighted potentially modifiable factors.

Characteristics and Clinical Outcomes After Osteochondral Allograft Transplantation for Treating Articular Cartilage Defects: Systematic Review and Single-Arm Meta-analysis of Studies From 2001 to 2020

Background

Osteochondral allograft transplantation (OCA) treats symptomatic focal cartilage defects with satisfactory clinical results.

Purpose

To comprehensively analyze the characteristics and clinical outcomes of OCA for treating articular cartilage defects.

Study Design

Systematic review; Level of evidence, 4.

Methods

We searched Embase, PubMed, Cochrane Database, and Web of Science for studies published between January 1, 2001, and December 31, 2020, on OCA for treating articular cartilage defects. Publication information, patient data, osteochondral allograft storage details, and clinical outcomes were extracted to conduct a comprehensive summative analysis.

Results

In total, 105 studies involving 5952 patients were included. The annual reported number of patients treated with OCA increased from 69 in 2001 to 1065 in 2020, peaking at 1504 cases in 2018. Most studies (90.1%) were performed in the United States. The mean age at surgery was 34.2 years, and 60.8% of patients were male and had a mean body mass index of 26.7 kg/m2. The mean lesion area was 5.05 cm2, the mean follow-up duration was 54.39 months, the mean graft size was 6.85 cm2, and the number of grafts per patient was 54.7. The failure rate after OCA was 18.8%, and 83.1% of patients reported satisfactory results. Allograft survival rates at 2, 5, 10, 15, 20, and 25 years were 94%, 87.9%, 80%, 73%, 55%, and 59.4%, respectively. OCA was mainly performed on the knee (88.9%). The most common diagnosis in the knee was osteochondritis dissecans (37.9%), and the most common defect location was the medial femoral condyle (52%). The most common concomitant procedures were high tibial osteotomy (28.4%) and meniscal allograft transplantation (24.7%). After OCA failure, 54.7% of patients underwent revision with primary total knee arthroplasty.

Conclusion

The annual reported number of patients who underwent OCA showed a significant upward trend, especially from 2016 to 2020. Patients receiving OCA were predominantly young male adults with a high body mass index. OCA was more established for knee cartilage than an injury at other sites, and its best indication was osteochondritis dissecans. This analysis demonstrated satisfactory long-term postoperative outcomes.

The Large Focal Isolated Chondral Lesion

Focal chondral defects (FCDs) of the knee can be a debilitating condition that can clinically translate into pain and dysfunction in young patients with high activity demands. Both the understanding of the etiology of FCDs and the surgical management of these chondral defects has exponentially grown in recent years. This is reflected by the number of surgical procedures performed for FCDs, which is now approximately 200,000 annually. This fact is also apparent in the wide variety of available surgical approaches to FCDs. Although simple arthroscopic debridement or microfracture are usually the first line of treatment for smaller lesions, chondral lesions that involve a larger area or depth require restorative procedures such as osteochondral allograft transplantation or other cell-based techniques. Given the prevalence of FCDs and the increased attention on treating these lesions, a comprehensive understanding of management from diagnosis to rehabilitation is imperative for the treating surgeon. This narrative review aims to describe current concepts in the treatment of large FCDs through providing an algorithmic approach to selecting interventions to address these lesions as well as the reported outcomes in the literature.

Inconsistent Reporting of Preauthorization Medical Criteria for Osteochondral Allograft Transplantation Surgery

BACKGROUND

Although osteochondral allograft (OCA) transplantation has been a standard treatment for patients with osteochondral lesions, there is a disagreement in commercial payers' medical criteria regarding the definition of medical suitability and thus authorization for OCA transplantation. The primary goal of this study was to understand where consensus between a committee of experienced cartilage restoration surgeon scientists and payer policies existed and where there was significant disagreement.

METHODS

U.S. private payers were identified by reviewing health insurance market research literature. Medical criteria were then obtained from publicly available payer medical polices. A literature review was conducted to identify supporting evidence for consensus statements based on private payer medical criteria. The MOCA (Metrics of Osteochondral Allograft) Committee, 30 experienced surgeons and subject-matter experts in OCA transplantation, used a Likert scale of 1 (strongly disagree) to 5 (strongly agree) to rank each statement. The extent of agreement and disagreement among participants was measured for each statement. Consensus was defined as agreement or disagreement of >75%.

RESULTS

Fifty-seven statements regarding relevant medical criteria for OCA transplantation were included in the survey. All 30 MOCA Committee members completed the survey (100% response rate). Over half of the statements (52.6%) did not reach consensus. Of the remaining 27 statements that reached consensus, respondents agreed or strongly agreed with 16 statements, and disagreed or strongly disagreed with 11 statements. Inconsistent voting was observed for statements related to osteoarthritis, inflammation, and degenerative changes.

CONCLUSIONS

Commercial payers are not consistent in the medical criteria used to define patient eligibility for authorization of OCA transplantation. In contrast, an expert panel of cartilage surgeons reached a consensus that OCA transplantation was clearly suitable for a variety of specific indications. This study demonstrates the need to standardize medical criteria for cartilage restoration based on the most current literature, as well as in conjunction with experienced cartilage restoration experts.

LEVEL OF EVIDENCE

Therapeutic Level V . See Instructions for Authors for a complete description of levels of evidence.

Algorithm for Treatment of Focal Cartilage Defects of the Knee: Classic and New Procedures

OBJECTIVE

To create a treatment algorithm for focal grade 3 or 4 cartilage defects of the knee using both classic and novel cartilage restoration techniques.

DESIGN

A comprehensive review of the literature was performed highlighting classic as well as novel cartilage restoration techniques supported by clinical and/or basic science research and currently being employed by orthopedic surgeons.

RESULTS

There is a high level of evidence to support the treatment of small to medium size lesions (<2-4 cm2) without subchondral bone involvement with traditional techniques such as marrow stimulation, osteochondral autograft transplant (OAT), or osteochondral allograft transplant (OCA). Newer techniques such as autologous matrix-induced chondrogenesis and bone marrow aspirate concentrate implantation have also been shown to be effective in select studies. If subchondral bone loss is present OAT or OCA should be performed. For large lesions (>4 cm2), OCA or matrix autologous chondrocyte implantation (MACI) may be performed. OCA is preferred over MACI in the setting of subchondral bone involvement while cell-based modalities such as MACI or particulated juvenile allograft cartilage are preferred in the patellofemoral joint.

CONCLUSIONS

Numerous techniques exist for the orthopedic surgeon treating focal cartilage defects of the knee. Treatment strategies should be based on lesion size, lesion location, subchondral bone involvement, and the level of evidence supporting each technique in the literature.

Comparison of Autologous Chondrocyte Implantation and Osteochondral Allograft Transplantation of the Knee in a Large Insurance Database: Reoperation Rate, Complications, and Cost Analysis

OBJECTIVE

To compare (1) the reoperation rates, (2) risk factors for reoperation, (3) 30-day complication rates, and (4) cost differences between autologous chondrocyte implantation (ACI) and osteochondral allograft transplantation (OCA) of the knee in a large insurance database.

DESIGN

Subjects who underwent knee ACI (Current Procedural Terminology [CPT] code 27412) or OCA (CPT code 27415) with minimum 2-year follow-up were queried from a national insurance database. Reoperation was defined by ipsilateral knee procedure after index surgery. Multivariate logistic regression models were built to determine the effect of independent variables (age, sex, tobacco use, obesity, diabetes, and concomitant osteotomy) on reoperation rates. The 30-day complication rates were assessed using ICD-9-CM codes. The cost of the procedures per patient was calculated. Statistical comparisons were made. All P values were reported with significance set at P < 0.05.

RESULTS

A total of 909 subjects (315 ACI and 594 OCA) were included (mean follow-up 39.2 months). There was a significantly higher reoperation rate after index ACI compared with OCA (67.6% vs. 40.4%, P < 0.0001). Concomitant osteotomy at the time of index procedure significantly reduced the risk for reoperation in both groups (odds ratio [OR] 0.2, P < 0.0001 and OR 0.2, P = 0.009). The complication rates were similar between ACI (1.6%) and OCA (1.2%) groups (P = 0.24). Day of surgery payments were significantly higher after ACI compared with OCA (P = 0.013).

CONCLUSIONS

Autologous chondrocyte implantation had significantly higher reoperation rates and cost with similar complication rates compared with OCA. Concomitant osteotomy significantly reduced the risk for reoperation in both groups.

Outcomes of Bulk Fresh Osteochondral Allografts for Cartilage Restoration in the Knee

BACKGROUND

Symptomatic osteochondral defects of the knee in young patients can cause substantial disability and predispose to osteoarthritis. Fresh osteochondral allografts (FOCAs) are a treatment option for such defects. With our institution having one of the longest-running FOCA programs, we investigated the long-term outcomes of bulk FOCA in the knee, focusing on graft survivorship, function, complications, and reoperation.

METHODS

A total of 244 patients underwent bulk FOCA in the knee from 1972 to 2018, with a mean age of 37.8 years (range, 10 to 75 years) and a mean follow-up of 9.0 years (range, 1.0 to 29.8 years). Cartilage defects were very large and uncontained, such that they were not amenable to plug transplantation. Survivorship according to Kaplan-Meier analysis was the primary outcome, and failure was defined as conversion to total knee arthroplasty, repeat allograft, graft removal, knee arthrodesis, or amputation. Functional outcome was evaluated with use of the modified Hospital for Special Surgery (mHSS) score, and radiographic evidence of osteoarthritis was classified with use of the Kellgren-Lawrence grading scale.

RESULTS

Graft survivorship was 86.6% at 5 years, 73.3% at 10 years, 58.1% at 15 years, 43.7% at 20 years, 31.9% at 25 years, and 22.6% at 30 years. The most common complications were pain (14.8%), malalignment (13.9%), and stiffness (5.8%). A total of 93 grafts (38.1%) failed at a mean of 11.0 years (range, 0.5 to 34.0 years). The mean mHSS score improved significantly, from 68.7 (range, 19 to 91) preoperatively to 80.3 (range, 52 to 100) at the time of the latest follow-up (p < 0.001). Preoperative mHSS score had a negative correlation with Kellgren-Lawrence grade at the time of the latest follow-up. Multivariate analysis revealed that graft location (i.e., medial-sided or multiple grafts) and increased age were significantly negatively associated with survival. Ten-year survival was >80% in patients below 50 years old, but <40% in patients >60 years old.

CONCLUSIONS

Bulk FOCA provided promising long-term graft survival and functional improvement in patients <50 years old. It can delay or prevent the need for total knee arthroplasty in young patients. Older patients and patients with a medial-sided graft, or multiple grafts within the same knee, had a less favorable prognosis.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cell-Free Biomimetic Osteochondral Scaffold for the Treatment of Knee Lesions: Clinical and Imaging Results at 10-Year Follow-up

BACKGROUND

Cell-free devices have been introduced to restore osteochondral defects, avoiding the limitations of cell-based procedures. Among these, an osteochondral scaffold made of type I collagen and hydroxyapatite has been investigated with promising results up to medium-term follow-up. However, the clinical and imaging results over time still need to be documented.

PURPOSE

To evaluate the clinical outcome and tissue maturation at long-term follow-up after the implantation of the osteochondral scaffold.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 24 patients (7 women, 17 men; age, 36 ± 9.5 years) underwent surgical implantation of the osteochondral scaffold and were prospectively evaluated before surgery, at 2-, 5-, and 10-year follow-up. The mean defect size was 2.9 ± 1.4 cm². Patients were evaluated using the International Knee Documentation Committee (IKDC) subjective and objective scores, and the activity level was documented with the Tegner score. Magnetic resonance imaging (MRI) evaluation involved the use of the magnetic resonance observation of cartilage repair tissue score combined with 5 more variables focused on the bone layer.

RESULTS

A statistically significant improvement of all clinical scores was documented from the baseline to the final evaluation. The IKDC subjective score improved from the preoperative level to 2 years (41 ± 13.2 and 77.1 ± 14.6, respectively) (P < .0005), with stable results up to 10 years (77.4 ± 19.4). The IKDC objective score changed from 52% of normal and nearly normal knees before the treatment to 84% at 10 years (P < .0005). Tegner sports activity at the final evaluation (3.8 ± 1.7) was higher compared with the preoperative level (1.6 ± 1.1; P < .05), but it remained significantly lower compared with the preinjury level (5.5 ± 2.6; P < .05). Treatment failed in 1 patient. Persisting graft alterations were observed on MRI scans, although without correlating with the clinical outcome.

CONCLUSION

The regenerative potential of this scaffold is limited, as demonstrated by the signal alterations persisting over time on MRI scans. On the other hand, the clinical improvement was significant and stable over time both in terms of subjective and objective outcomes, including activity level, with overall good results.

Rehabilitation and Return-to-Play Criteria After Fresh Osteochondral Allograft Transplantation: A Systematic Review

Background:

Fresh osteochondral allograft (OCA) is a treatment option that allows for the transfer of size-matched allograft cartilage and subchondral bone into articular defects of the knee. Although long-term studies show good functional improvement with OCA, there continues to be wide variability and a lack of consensus in terms of postoperative rehabilitation protocols and return to sport.

Purpose:

To systematically review the literature and evaluate the reported rehabilitation protocols after OCA of the knee, including weightbearing and range of motion (ROM) restrictions as well as return-to-play criteria.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

PubMed, EMBASE, Cumulative Index of Nursing Allied Health Literature, SPORTDiscus, and Cochrane databases were searched according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies on knee OCA. Studies were included if they reported return-to-play data or postsurgical rehabilitation protocols.

Results:

A total of 62 studies met the inclusion criteria, with a total of 3451 knees in 3355 patients. Concomitant procedures were included in 30 of these studies (48.4%). The most commonly cited rehabilitation protocols included weightbearing restrictions and ROM guidelines in 100% and 90% of studies, respectively. ROM was most commonly initiated within the first postoperative week, with approximately half of studies utilizing continuous passive motion. Progression to weightbearing as tolerated was reported in 60 studies, most commonly at 6 weeks (range, immediately postoperatively to up to 1 year). Of the 62 studies, 37 (59.7%) included an expected timeline for either return to play or return to full activity, most commonly at 6 months (range, 4 months to 1 year). Overall, 13 studies (21.0%) included either objective or subjective criteria to determine return to activity within their rehabilitation protocol.

Conclusion:

There is significant heterogeneity for postoperative rehabilitation guidelines and the return-to-play protocol after OCA of the knee in the literature, as nearly half of the included studies reported use of concomitant procedures. However, current protocols appear to be predominantly time-based without objective criteria or functional assessment. Therefore, the authors recommend the development of objective criteria for patient rehabilitation and return-to-play protocols after OCA of the knee.

Unicompartmental bipolar osteochondral and meniscal allograft transplantation is effective for treatment of medial compartment gonarthrosis in a canine model

Osteochondral allograft (OCA) transplantation can restore large articular defects in the knee. Bipolar OCA transplantations for partial and whole joint resurfacing often have less favorable results than single-surface transplants. This study was designed to use a large animal model to test the hypothesis that unicompartmental bipolar osteochondral and meniscal allograft transplantation (BioJoint) would be as or more effective for treatment of medial compartment osteoarthritis (OA) compared to standard-of-care nonoperative treatment. OA was induced in one knee of each research hound (n = 8) using a meniscal release model and pretreatment assessments were performed. After 3 months, dogs were randomly assigned to either the control group (n = 4, no surgical intervention, daily nonsteroidal antiinflammatory drugs [NSAIDs]) or the BioJoint group (n = 4). Clinical, radiographic, and arthroscopic assessments were performed longitudinally and histopathology was evaluated at the 6-month endpoint. At study endpoint, functional, pain, and total pressure index measures, as well as radiographic and arthroscopic grading of graft appearance and joint health, demonstrated superior outcomes for BioJoints compared to NSAID controls. Furthermore, histologic assessments showed that osteochondral and meniscal transplants maintain integrity and integrated into host tissues. Clinical significance: The results support the safety and efficacy of unicompartmental bipolar osteochondral and meniscal allograft transplantation in a preclinical model with highly functional outcomes without early OA progression.

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

Background:

Osteochondral allograft (OCA) transplantation has evolved into a first-line treatment for large chondral and osteochondral defects, aided by advancements in storage protocols and a growing body of clinical evidence supporting successful clinical outcomes and long-term survivorship. Despite the body of literature supporting OCAs, there still remains controversy and debate in the surgical application of OCA, especially where high-level evidence is lacking.

Purpose:

To develop consensus among an expert group with extensive clinical and scientific experience in OCA, addressing controversies in the treatment of chondral and osteochondral defects with OCA transplantation.

Study Design:

Consensus statement.

Methods:

A focus group of clinical experts on OCA cartilage restoration participated in a 3-round modified Delphi process to generate a list of statements and establish consensus. Questions and statements were initially developed on specific topics that lack scientific evidence and lead to debate and controversy in the clinical community. In-person discussion occurred where statements were not agreed on after 2 rounds of voting. After final voting, the percentage of agreement and level of consensus were characterized. A systematic literature review was performed, and the level of evidence and grade were established for each statement.

Results:

Seventeen statements spanning surgical technique, graft matching, indications, and rehabilitation reached consensus after the final round of voting. Of the 17 statements that reached consensus, 11 received unanimous (100%) agreement, and 6 received strong (80%-99%) agreement.

Conclusion:

The outcomes of this study led to the establishment of consensus statements that provide guidance on surgical and perioperative management of OCAs. The findings also provided insights on topics requiring more research or high-quality studies to further establish consensus and provide stronger evidence.

Management of Large Focal Chondral and Osteochondral Defects in the Knee

Large, focal articular cartilage defects of the knee (> 4 cm²) can be a source of significant morbidity and often require surgical intervention. Patient- and lesion-specific factors must be identified when evaluating a patient with an articular cartilage defect. In the management of large cartilage defects, the two classically utilized cartilage restoration procedures are osteochondral allograft (OCA) transplantation and cell therapy, or autologous chondrocyte implantation (ACI). Alternative techniques that are available or currently in clinical trials include a hyaluronan-based scaffold plus bone marrow aspirate concentrate, a third-generation autologous chondrocyte implant, and an aragonite-based scaffold. In this review, we will focus on OCA and ACI as the mainstay in management of large chondral and osteochondral defects of the knee. We will discuss the techniques and associated clinical outcomes for each, while including a brief mention of alternative treatments. Overall, cartilage restoration techniques have yielded favorable clinical outcomes and can be successfully employed to treat these challenging large focal lesions.

Use of a Superolateral Portal and 70° Arthroscope to Optimize Visualization of Patellofemoral Tracking and Osteochondral Lesions in Patients With Recurrent Patellar Instability

Surgical treatment of patellofemoral instability and associated cartilaginous lesions can be technically challenging. Visualization of patellar tracking and underlying osteochondral lesions is paramount to operative success. To treat these conditions effectively, a comprehensive arthroscopic assessment of the patellofemoral joint as well as dynamic visualization of patella tracking must be achieved. Visualization of the patellofemoral joint-in particular, the articular cartilage of the patella and trochlea morphology-can be difficult when using traditional anteromedial or anterolateral portals and a 30° arthroscope lens. The technique described here uses an accessory superolateral portal and a 70° arthroscope to achieve significantly improved visualization of the patellofemoral articulation, in particular the chondral surfaces. This vantage point aids the surgeon in effectively evaluating patellar tracking, trochlea morphology, and importantly, osteochondral lesion location to help guide treatment algorithms in the patellofemoral joint.

Osteochondral Allograft Transplant of the Patella Using Femoral Condylar Allografts: Magnetic Resonance Imaging and Clinical Outcomes at Minimum 2-Year Follow-up

Background:

Fresh osteochondral allograft transplant (OCA) has good outcomes in the knee. However, donor tissue for patellar OCA is limited. Outcomes after nonorthotopic OCA of the patella using more readily available femoral condylar allograft (FCA) tissue have not been previously reported.

Purpose:

To assess short-term magnetic resonance imaging (MRI) and minimum 2-year clinical outcomes of nonorthotopic patellar OCA using an FCA donor.

Study Design:

Case series; Level of evidence, 4.

Methods:

A prospective institutional cartilage registry was reviewed to identify patients treated with patellar OCA using an FCA donor between August 2009 and June 2016. OCA plugs were obtained from the FCA at its trochlear-condylar junction and implanted into the recipient patellar lesion. Early postoperative MRI scans were graded by a blinded musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS). International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), Knee Outcomes Survey–Activities of Daily Living (KOS-ADL), and pain visual analog scale (VAS) scores were collected preoperatively and at minimum 2 years postoperatively, and outcomes were compared using the paired t test.

Results:

A total of 25 patients were included for clinical outcome analysis and 20 patients for MRI analysis. MRI scans obtained at a mean of 11.4 months (range, 6-22 months) postoperatively showed a mean total OCAMRISS score of 9.0 (range, 7-11); mean bone, cartilage, and ancillary subscores were 2.6, 3.7, and 2.6, respectively. At the latest follow-up (mean, 46.5 months; range, 24-85 months), postoperative improvements were noted in IKDC (from 45.0 to 66.2; P = .0002), KOS-ADL (from 64.3 to 80.4; P = .0012), and VAS (from 5.1 to 3.4; P = .001) scores, with IKDC and KOS-ADL scores above the corresponding previously reported minimal clinically important difference.

Conclusion:

In this study, patellar OCA using nonorthotopic FCA led to significant short-term improvements in pain and patient-reported outcomes. The majority of nonorthotopic patellar grafts demonstrated full osseous incorporation and good restoration of the articular surface on MRI at short-term follow-up.

Current solutions for the treatment of chronic articular cartilage defects in the knee

Chondral and osteochondral defects in the knee are common and may lead to degenerative joint disease if treated inappropriately.

Conventional treatments such as microfracture often result in fibrocartilage formation and are associated with inferior results. Additionally, microfracture is generally unsuitable for the treatment of defects larger than 2–4 cm².

The osteochondral autograft transfer system (OATS) has been shown to produce superior clinical outcomes to microfracture but is technically difficult and may be associated with donor-site morbidity. Osteochondral allograft use is limited by graft availability and failure of cartilage incorporation is an issue.

Autologous chondrocyte implantation (ACI) has been shown to result in repair with hyaline-like cartilage but involves a two-stage procedure and is relatively expensive.

Rehabilitation after ACI takes 12 months, which is inconvenient and not feasible for athletic patients.

Newer methods to regenerate cartilage include autologous stem cell transplantation, which may be performed as a single-stage procedure, can have a shorter rehabilitation period and is less expensive than ACI. Longer-term studies of these methods are needed.

Cite this article: EFORT Open Rev 2020;5:156-163. DOI: 10.1302/2058-5241.5.190031

Return to Work Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation

PURPOSE

To assess the timeline of return to work (RTW) following opening-wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) of the medial femoral condyle.

METHODS

Consecutive patients undergoing HTO + OCA due to focal chondral deficiency and varus deformity were retrospectively identified and reviewed at a minimum of 2 years following surgery. Patients completed a subjective work questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire.

RESULTS

Twenty-eight patients (average age: 36.0 ± 7.9 years) were included at 6.7 ± 4.1 years postoperatively. Twenty-six patients were employed before surgery and 25 patients (96.2%) returned to work following HTO + OCA. However, only 88.5% of patients were able to return to the same level of occupational intensity by 3.5 ± 2.9 months postoperatively. The rate of RTW to the same occupational intensity for sedentary, light, medium, and heavy intensity occupations was 100%, 100%, 88.9%, and 80% (P = .8), whereas the duration of RTW was 9.0 ± 7.1 months, 1.7 ± 1.4 months, 2.7 ± 0.9 months, and 4.2 ± 1.9 months (P = .006), respectively. Two patients (7.7%) underwent knee replacement by 5.3 ± 3.1 years postoperatively due to progression of osteoarthritis in the medial compartment.

CONCLUSIONS

In patients with focal chondral deficiency and varus deformity, HTO + OCA provides a high rate of RTW (96.2%) by 3.5 ± 2.9 months postoperatively. However, patients with greater-intensity occupations may take longer to return to work than those with less physically demanding occupations.

LEVEL OF EVIDENCE

IV, Retrospective Case Series.