Failures in bipolar fresh osteochondral allograft for the treatment of end-stage knee osteoarthritis

Subchondral bone: An emerging target for the treatment of articular surface lesions of the knee

Purpose

When dealing with the health status of the knee articular surface, the entire osteochondral unit has gained increasing attention, and in particular the subchondral bone, which plays a key role in the integrity of the osteochondral unit. The aim of this article was to discuss the current evidence on the role of the subchondral bone.

Methods

Experts from different geographical regions were involved in performing a review on highly discussed topics about the subchondral bone, ranging from its etiopathogenetic role in joint degeneration processes to its prognostic role in chondral and osteochondral defects, up to treatment strategies to address both the subchondral bone and the articular surface.

Discussion

Subchondral bone has a central role both from an aetiologic point of view and as a diagnostic tool, and its status was found to be relevant also as a prognostic factor in the follow-up of chondral treatment. Finally, the recognition of its importance in the natural history of these lesions led to consider subchondral bone as a treatment target, with the development of osteochondral scaffolds and procedures to specifically address osteochondral lesions.

Conclusion

Subchondral bone plays a central role in articular surface lesions from different points of view. Several aspects still need to be understood, but a growing interest in subchondral bone is to be expected in the upcoming future towards the optimization of joint preservation strategies.

Level of Evidence

Level V, expert opinion.

Knee Joint Preservation in Tactical Athletes: A Comprehensive Approach Based upon Lesion Location and Restoration of the Osteochondral Unit

The unique physical demands of tactical athletes put immense stress on the knee joint, making these individuals susceptible to injury. In order to ensure operational readiness, management options must restore and preserve the native architecture and minimize downtime, while optimizing functionality. Osteochondral lesions (OCL) of the knee have long been acknowledged as significant sources of knee pain and functional deficits. The management of OCL is predicated on certain injury characteristics, including lesion location and the extent of subchondral disease. Techniques such as marrow stimulation, allograft and autologous chondrocyte implantation are examined in detail, with a focus on their application and suitability in tactical athlete populations. Moreover, the restoration of the osteochondral unit (OCU) is highlighted as a central aspect of knee joint preservation. The discussion encompasses the biomechanical considerations and outcomes associated with various cartilage restoration techniques. Factors influencing procedure selection, including lesion size, location, and patient-specific variables, are thoroughly examined. Additionally, the review underscores the critical role of post-operative rehabilitation and conditioning programs in optimizing outcomes. Strengthening the surrounding musculature, enhancing joint stability, and refining movement patterns are paramount in facilitating the successful integration of preservation procedures. This narrative review aims to provide a comprehensive resource for surgeons, engineers, and sports medicine practitioners engaged in the care of tactical athletes and the field of cartilage restoration. The integration of advanced preservation techniques and tailored rehabilitation protocols offers a promising avenue for sustaining knee joint health and function in this demanding population.

Engaging Patients and Caregivers to Develop a Patient-Centered Agenda for Comparative Effectiveness Research Focused on the Treatment of Complex Knee Problems

Complex articular cartilage loss in the knee is being diagnosed more frequently and earlier in life, and patients are faced with major decisions regarding invasive surgical interventions at increasingly younger ages. There is a critical unmet need to provide patient-centered comparative effectiveness research for the hundreds of thousands of patients faced with these treatment decisions each year. Toward filling the need, we developed the Patient AdvisoR Team iN Orthopaedic ReSearch (PARTNORS) program. We recruited a diverse group of patients and caregivers with lived experiences in dealing with complex knee problems to define patient-centered research priorities for comparative biological and artificial knee surgery research for middle-aged adults. Adapting the Stakeholder Engagement in Question Development and Prioritization Method, PARTNORS defined a 20-question list of patient-centered research questions of factors influencing a patients' choice between biological and artificial knee surgeries. The highest prioritized research question related to functional level postsurgery as it relates to daily activities and recreational activities. The second highest prioritized research questions related to insurance coverage and financial costs. Other prioritized research areas included caregiving needs, implant longevity, recovery and rehabilitation time, patient satisfaction and success rates, individual characteristics, and risks. By engaging a group of patients and caregivers and including them as members of a multidisciplinary research team, comparative effectiveness research that includes patient-centered factors that go beyond typical clinical success indicators for knee surgery can be designed to allow physicians and patients to work together toward evidence-based shared decisions. This shared decision-making process helps to align patients' and health care team's goals and expectations to improve outcomes.

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.

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

Knee articular cartilage defects can result in significant pain and loss of function in active patients. Osteochondral allograft (OCA) transplantation offers a single-stage solution to address large chondral and osteochondral defects by resurfacing focal cartilage defects with mature hyaline cartilage. To date, OCA transplantation of the knee has demonstrated excellent clinical outcomes and long-term survivorship. However, significant variability still exists among clinicians with regard to parameters for graft acceptance, surgical technique, and rehabilitation. Technologies to optimize graft viability during storage, improve osseous integration of the allograft, and shorten recovery timelines after surgery continue to evolve. The purpose of this review is to examine the latest evidence on treatment indications, graft storage and surgical technique, patient outcomes and survivorship, and rehabilitation after surgery.

Fresh Osteochondral Allograft Transplantation in Osteochondritis Dissecans in the Knee Joint

Osteochondritis dissecans (OCD) is a chronic and painful joint condition that can occur from childhood through to adult life. Microtrauma, vascular insufficiency, or abnormal endochondral ossification are the most common causes of OCD. Reconstructive techniques for OCD of the knee are typically necessary when either non-operative or reparative/regenerative operative treatments fail, or when the OCD is irreversible. To analyze the clinical outcomes and failure rates of fresh osteochondral allograft transplantation (FOCA) used as a reconstructive strategy in OCD patients, an in-depth search was carried out on the PubMed, Scopus, and Web of Science databases concerning the existing evidence related to the use of FOCA for OCD patients in the knee joint. A total of 646 studies were found through the search and 2 studies were added after a cross-referenced examination of the articles within the bibliography. Six studies with a total of 303 OCD lesions treated with FOCA, with a mean follow-up of 6.3 years, were included. Although a limited number of low-level evidence studies on this topic are available in previous research, satisfactory clinical results and survival rates of the reconstruction are reported. However, to better define the real advantages of FOCA in the healing process of OCD lesions, comparative studies with different techniques are needed.

Multiple Lesion Matrix-Induced Chondrocyte Implantation Procedure in a Collegiate Football Athlete: A Case Report

CASE

A 21-year-old male division I collegiate athlete presented for right knee pain, effusion, and mechanical symptoms. The patient was found to have 2.4 × 2-cm medial patellar facet, 1 × 0.8-cm central trochlea, and 2.5 × 3-cm lateral femoral condyle articular cartilage defects on arthroscopy. The patient was treated with a matrix-induced autologous chondrocyte implantation (MACI) procedure for all 3 lesions. At 9 months postoperatively, the patient returned to full American football activities and remains asymptomatic 16 months postoperatively.

CONCLUSION

Multiple lesions and lesions involving the patellofemoral joint can be treated with a MACI procedure with short-term promising results in high-demand athletes.

Cartilage Restoration for Tibiofemoral Bipolar Lesions Results in Promising Failure Rates: A Systematic Review

Purpose

The purpose of the present study is to systematically review the available literature for management of bipolar lesions within the tibiofemoral joint and determine whether tibiofemoral cartilage restoration is an effective treatment modality.

Methods

PubMed and MEDLINE databases were queried between 2000 and 2020 using the following keywords: “osteochondral” and “knee” and “microfracture,” “autologous chondrocyte implantation (ACI),” or “transplantation." Articles were reviewed for the presence of a bipolar or “kissing” tibiofemoral lesion and reported lesion size, concomitant procedures, failure rates, and time to failure.

Results

After screening 1,295 articles, there were 4 articles available for analysis and a total of 152 knees involving the management of bipolar tibiofemoral lesions. Age ranged from 14 to 60 years, and mean follow-up was between 12 and 240 months. There was 1 retrospective cohort study (36 knees) and 3 case series (mean, 38.7 ± 17.5 knees). There were 58 knees treated with bipolar osteochondral allograft (OCA) transplantation, 58 knees treated with bipolar ACI, 20 knees treated with femoral OCA and tibial debridement, and 16 knees treated with femoral OCA and tibial microfracture. There were 37 failures (24.3%): 16 patients (10.5%) were converted to unicompartmental or total knee arthroplasty, 4 restorative procedures (2.6%) were revised, and 8 patients (1.6%) had unsatisfactory outcomes only. The remaining 15 failures (9.9%) had an unspecified combination of objective failure. The mean rate of failure ranged between 0% and 44.1% (I² = 83.2%). The mean time to failure ranged between 2.7 and 4.1 years (I² = 79.1%).

Conclusions

Cartilage restoration, through both ACI and OCA, had failure rates between 0% and 44% in patients with bipolar lesions of the tibiofemoral compartment. Although a higher level of evidence is required to prove efficacy, the current study demonstrates midterm survivorship rates between 55% and 100%, which may delay the need for secondary arthroplasty.

Level of Evidence

Level IV, systematic review of Level IV studies.

Cartilage Restoration of Bipolar Lesions Within the Patellofemoral Joint Delays Need for Arthroplasty: A Systematic Review of Rates of Failure

Purpose

The purpose of the present review is to systematically review the available literature for failure rates and complications of cartilage restoration of bipolar chondral defects in the patellofemoral (PF) joint to assess the ability to treat these lesions without arthroplasty.

Methods

PubMed and MEDLINE databases were queried between 2000 to 2020 using the keywords "osteochondral" and "knee" and "microfracture," "autologous chondrocyte implantation (ACI)," or "transplantation." Patient selection included patients with bipolar chondral lesions of the patellofemoral joint that were treated with cartilage restoration procedures. Treatment of PF joints were reviewed for surgical indications/technique, rates of failure, defect characteristics, and time to failure. For the purposes of this study, failure was defined by each individual author on their respective studies.

Results

After screening 1,295 articles, there were 8 publications analyzed quantitatively and 10 articles analyzed both quantitatively and qualitatively. A total of 249 knees involved bipolar lesions of the patellofemoral joint. The weighted average age was 36.5 ± 10.4 years, and weighted average follow-up was 89.0 ± 31.7 months. There were failures in 0% to 50% of cases, revision procedures in 0% to 10% of cases, conversion to arthroplasty in in 0% to 50% of cases, and unsatisfactory outcome without revision in 0% to 8.3% of cases. The range in average failure rate was 0% to 50.0% (I² = 68.0%), whereas the range in average time to failure was 2.9 to 6.8 years (I² = 79.0%).

Conclusion

From the available data, established cartilage restoration procedures may provide favorable patient-reported function, avoidance of secondary surgery, and joint preservation in at least 80% of patients at short- to mid-term follow-up.

Level of Evidence

Level IV, systematic review of Level IV studies.

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.

Fresh Osteochondral Allograft Transplants in the Knee: Bipolar and Beyond

Knee patients who have sustained chondral and osteochondral lesions suffer from debilitating pain, which can ultimately lead to posttraumatic osteoarthritis and whole-joint disease. Older, nonactive patients are traditionally steered toward total knee arthroplasty (TKA), but younger, active patients are not good candidates for TKA based on implant longevity, complications, morbidity, and risk for revision, such that treatment strategies at restoring missing hyaline cartilage and bone are highly desired for this patient population. Over the past four decades, fresh osteochondral allograft (OCA) transplantation has been developed as a treatment method for large (> 2.5 cm²) focal full-thickness articular cartilage lesions. This article documents our own institutional OCA journey since 2016 through enhanced graft preservation techniques (the Missouri Osteochondral Preservation System, or MOPS), technical improvements in surgical techniques, use of bone marrow aspirate concentrate, bioabsorbable pins and nails, and prescribed and monitored patient-specific rehabilitation protocols. Further follow-up with documentation of long-term outcomes will provide insight for continued optimization for future applications for OCA transplantation, potentially including a broader spectrum of patients appropriate for this treatment. Ongoing translational research is necessary to blaze the trail in further optimizing this treatment option for patients.

Bipolar Osteochondral Allograft Transplantation of the Patella and Trochlea

OBJECTIVE

To evaluate clinical, functional, and radiographic outcomes of patients who underwent bipolar osteochondral allograft transplantation (OCAT) of the patellofemoral joint (PFJ).

DESIGN

Prospectively collected data on 18 knees who underwent fresh osteochondral allograft transplantation of the patella and trochlea by a single surgeon were reviewed. Inclusion criteria were: high-grade chondral lesions of PFJ (5 knees), or recurrent patella dislocations with trochlear dysplasia and chondral injury to the patella and/or trochlea (13 knees). Functional scores were obtained preoperatively and at follow-up appointments included Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), Oxford, Cincinnati, Tenger-Lysholm, visual analogue scale (VAS)-pain, and Single Assessment Numeric Evaluation (SANE). Grafts were also evaluated using Osteochondral Allograft MRI Scoring System (OCAMRISS).

RESULTS

Three patients were lost to follow-up, leaving 4 knees in group 1, and 11 knees in group 2. Average age was 28.9 years (range 16-52 years). The average follow-up was 33.2 months (range 12-64 months). There was significant improvement of KOOS (from 38.7 to 83.1), IKDC (from 28.2 to 76.6), Tegner-Lysholm (from 38.3 to 88.3), Oxford (from 22.7 to 42.9), Cincinnati (from 35.1 to 83.6), VAS (from 71 to 17.9.), and SANE (from 43.3 to 83) (P < 0.0001). The OCAMRISS score for patella was 2.23 and for trochlea 4.69. There were no revisions or conversions to arthroplasty.

CONCLUSION

Bipolar OCAT of the patella and trochlea provide significant improvement in functional outcomes, relief from pain, activity level, and prevent recurrent instability.

An Expert Consensus Statement on the Management of Large Chondral and Osteochondral Defects in the Patellofemoral Joint

Background

Cartilage lesions of the patellofemoral joint constitute a frequent abnormality. Patellofemoral conditions are challenging to treat because of complex biomechanics and morphology.

Purpose

To develop a consensus statement on the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint using a modified Delphi technique.

Study Design

Consensus statement.

Methods

A working group of 4 persons generated a list of statements related to the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint to form the basis of an initial survey for rating by a group of experts. The Metrics of Osteochondral Allografts (MOCA) expert group (composed of 28 high-volume cartilage experts) was surveyed on 3 occasions to establish a consensus on the statements. In addition to assessing agreement for each included statement, experts were invited to propose additional statements for inclusion or to suggest modifications of existing statements with each round. Predefined criteria were used to refine statement lists after each survey round. Statements reaching a consensus in round 3 were included within the final consensus document.

Results

A total of 28 experts (100% response rate) completed 3 rounds of surveys. After 3 rounds, 36 statements achieved a consensus, with over 75% agreement and less than 20% disagreement. A consensus was reached in 100.00% of the statements relating to functional anatomy of the patellofemoral joint, 88.24% relating to surgical indications, 100.00% relating to surgical technical aspects, and 100.00% relating to rehabilitation, with an overall consensus of 95.5%.

Conclusion

This study established a strong expert consensus document relating to the functional anatomy, surgical indications, donor graft considerations for osteochondral allografts, surgical technical aspects, and rehabilitation concepts for the management of large chondral and osteochondral defects in the patellofemoral joint. Further research is required to clinically validate the established consensus statements and better understand the precise indications for surgery as well as which techniques and graft processing/preparation methods should be used based on patient- and lesion-specific factors.

Fresh Osteochondral Resurfacing of the Patellofemoral Joint

Large osteochondral lesions of the knee in young patients continue to be a challenge for orthopaedic surgeons and the focus of continual research. This is particularly true if the injury is a consequence of a dysplastic trochlea and involves both articular surfaces of the biomechanically complex patellofemoral joint. To obtain a healthy and congruent patellofemoral joint, the use of a bipolar fresh osteochondral allograft transplantation of the patella and trochlea is one of the few options to biologically treat these injuries. This would achieve a replacement of the entire articular surface of the patellofemoral joint with a high number of viable chondrocytes and respect the unique structural characteristics of the cartilage. The aim of this study was to obtain symptomatic and functional improvements while delaying the timing of prosthetic surgery. We present a reproducible although demanding surgical technique to perform a bipolar fresh osteochondral allograft transplantation of the patella and trochlea.

Clinical Outcomes of Multifocal Osteochondral Allograft Transplantation of the Knee: An Analysis of Overlapping Grafts and Multifocal Lesions

BACKGROUND

There is a paucity of literature regarding the outcomes of adjacent-plug osteochondral allograft transplantation (OCA) for irregular or ovoid lesions and multifocal OCA for multicompartmental, focal lesions.

PURPOSE

To quantify the survival of multiplug OCA for larger, high-grade chondral lesions with the "snowman" technique versus that of multicompartmental or bipolar OCA.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent primary, multiplug OCA for large unicondylar, multicompartmental (eg, bipolar patellofemoral and condylar, bicondylar), or bipolar chondral defects (ie, patellofemoral) with a minimum 2-year follow-up by a single surgeon from April 1, 2003, to April 1, 2015, were analyzed. Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on second-look arthroscopic surgery.

RESULTS

Twenty-six patients (28 knees) were identified, with 22 patients (24 knees; 50% female; mean age, 31.9 ± 9.1 years) having at least 2-year clinical follow-up (85.7%). Nine patients (9 knees) underwent isolated, condylar OCA with the snowman technique and had a mean follow-up of 7.4 ± 3.6 years (range, 1.38-11.14 years), while 13 additional patients (15 knees) underwent multifocal OCA and had a mean follow-up of 6.4 ± 3.9 years (range, 2.07-12.38 years). Reoperations were common, with 44.4% (n = 4) of the snowman group and 20.0% (n = 3) of the multifocal group undergoing at least 1 reoperation. There were 3 failures (33.3%) in the snowman group at a mean 7.7 ± 5.5 years and 1 failure (6.7%) in the multifocal group at 4.5 ± 0.0 years, with all undergoing secondary total knee arthroplasty. Patients who underwent snowman OCA demonstrated significant postoperative improvement in the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscore and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) overall score ( P < .05 for both). Patients who underwent multifocal OCA demonstrated significant improvement in the International Knee Documentation Committee score; KOOS symptoms, activities of daily living, sport, and quality of life subscores; WOMAC stiffness, function, and overall subscores; and 12-Item Short Form Health Survey physical component summary score ( P < .05 for all).

CONCLUSION

Patients who underwent unicondylar, multiplug OCA using the snowman technique demonstrated inferior clinical outcomes, higher reoperation rates, and greater failure rates than those who underwent isolated single-graft transplantation. By contrast, multifocal OCA may be a viable knee preservation technique for young, active patients with multicompartmental chondral disease, leading to improved clinical outcomes and low reoperation and failure rates at midterm follow-up.

Large Osteochondral Allografts of the Knee: Surgical Technique and Indications

Large osteochondral allograft (OCA) transplant has become a valid alternative to restore articular surface in challenging articular lesions in young and active patients, either in primary or in revision procedures. Several studies support the effectiveness and safety of OCA, but costs and graft availability limit their use. The indications are the treatment of symptomatic full-thickness cartilage lesions greater than 3 cm ² , deep lesions with subchondral damage, or revision procedures when a previous treatment has failed. The goal of the transplant is to restore the articular surface with a biological implant, allow return to daily/sports activities, relieve symptoms, and delay knee arthroplasty. Grafts can be fresh, fresh-frozen, or cryopreserved; these different storage procedures significantly affect cell viability, immunogenicity, and duration of the storage. Dowel and shell technique are the two most commonly used procedures for OCA transplantation. While most cartilage lesions can be treated with the dowel technique, large and/or geometrically irregular lesions should be treated with the shell technique. OCA transplantation for the knee has demonstrated reliable mid- to long-term results in terms of graft survival and patient satisfaction. Best results are reported: in unipolar lesions, in patients younger than 30 years, in traumatic lesions and when the treatment is performed within 12 months from the onset of symptoms.

Myrtol improves post-traumatic knee osteoarthritis by regulation of reactive oxygen species, transforming growth factor β1 and apoptosis in a mouse model

The present study tested whether myrtol improves post-traumatic knee osteoarthritis (PTKO) by regulating the reactive oxygen species (ROS), transforming growth factor β1 (TGF-β1) and apoptosis in a mouse model. PTKO model mice were administered with 150, 300 or 450 mg/kg myrtol for 8 weeks. ELISA analysis was used to measure tumor necrosis factor-α, interleukin-6, malondialdehyde, superoxide dismutase, reactive oxygen species and TGF-β1 levels. Caspase-3 and Bax protein expressions were analyzed using western blot analysis. In the current study, treatment with myrtol improved the tissue damage and osteoarthritis score, while it also reversed the subchondral bone thickness, subchondral bone density, trabecular bone volume/relative trabecular bone volume ratio and trabecular bone spacing in PTKO mice. The activity of tumor necrosis factor α, interleukin-6, TGF-β1, malondialdehyde, superoxide dismutase and ROS were effectively inhibited, and the protein expression of caspase-3 and Bax were clearly suppressed by treatment with myrtol in a mouse model of PTKO. In conclusion, the results demonstrated that myrtol treatment improved PTKO through the suppression of inflammation, oxidative stress, ROS, TGF-β1 and Bax/caspase-3 in mice, and myrtol may be a potential agent for clinical therapy.

High mid-term revision rate after treatment of large, full-thickness cartilage lesions and OA in the patellofemoral joint using a large inlay resurfacing prosthesis: HemiCAP-Wave®

PURPOSE

The HemiCAP-Wave® implant for the patellofemoral resurfacing treatment of large cartilage lesions and osteoarthritis (OA) was introduced in 2009. The outcome of a prospective cohort study of 18 patients with large trochlea lesions or isolated OA treated with the HemiCAP-Wave® implant is presented with up to a 6-year survival rate, and hypothesised short-to mid-term reduced pain and improved function.

METHODS

Indication for treatment with the HemiCAP-Wave® implant was a symptomatic, large cartilage lesion in trochlea demonstrated by MRI or arthroscopy, which was ICRS grades 3-4 and larger than 4 cm². Patients were followed for 2 years with American Knee Society Subjective outcome Scores (AKSS), pain scores and radiographic evaluations and for up to 6 years with complications and reoperations.

RESULTS

At the 1- and 2-year follow-up mean AKSS clinical score, the mean AKSS function score and mean pain score improved significantly. Within 6 years, 28 % of the implants were revised to arthroplasty due to the progression of cartilage lesions, osteoarthritis or increased knee pain.

CONCLUSION

The present study demonstrated an improved short- to mid-term clinical outcome and reduced pain but high mid-term revision rate after patellofemoral inlay resurfacing using the HemiCAP-Wave® implant. Patellofemoral resurfacing implantation treatment with a large inlay prosthesis can offer temporary treatment for large isolated patellofemoral cartilage lesions or OA in younger patients with almost healthy cartilage in the other compartments who are not yet eligible for arthroplasty treatment.

LEVEL OF EVIDENCE

IV.

Fresh osteochondral allotransplants: Outcomes, failures and future developments

Osteochondral allografts are used to treat many different conditions as acute traumatic large-sized lesions, degenerative osteoarthritis, osteochondritis dissecans, avascular necrosis or in case of failure of previous procedures particularly in young patients for whom primary prosthesis is not desirable. Fresh allografts present the advantage of having mature viable hyaline cartilage, not causing donor morbidity, allowing the restoration of even large defects in a single surgical session. Conversely, they could account for risks of disease transmission, immunologic reactions, and for limited availability. The present review aimed to analyze published studies of the last decade in which patients received fresh osteochondral allografts by dividing them for knee or ankle regenerative purposes. We wish to report the observed failure rates and particularly to collect any other reported side effect or outcome for identifying major problems and limits linked to the procedure and for delineating possible future researches and approaches. The overall success rates resulted ranging from 5.3% to 48.3% in the ankle at a mean follow up of 3.3 years and from 0% to 85.7% in the knee at a mean follow up of 7.1 years. Among other outcomes, occurrence or progression of arthritis, osteolysis, graft instability, fractures, nonunions, edema and infections were recorded. Overall, the lack of well designed randomized and controlled clinical trials, of immunological determination of the anti-donor antibodies development and of local and systemic biomarkers to detect reaction to the graft seems to be the major drawback. Improvements in these limiting factors might be desirable in order to enhance the clinical scenario of a well-established and successful procedure to give, especially for young patients, a real regeneration of the joint.

Osteochondral allograft

Over the past decade, osteochondral allograft transplantation has soared in popularity. Advances in storage techniques have demonstrated improved chondrocyte viability at longer intervals and allowed for potential of increased graft availability. Recent studies have stratified outcomes according to location and etiology of the chondral or osteochondral defect. Unipolar lesions generally have favorable outcomes with promising 10-year survival rates. Though those undergoing osteochondral allograft transplantation often require reoperation, patient satisfaction remains high.

Regenerative Engineering of Cartilage Using Adipose-Derived Stem Cells

Injury to the articular cartilage occurs commonly in the general population and undergoes minimal spontaneous healing. Traditional methods of cartilage repair provide no long-term cure and are significant causes of morbidity. For this reason, stem cell therapies have recently been investigated for their ability to regenerate cartilage, and the results have been promising. Since the discovery that adipose tissue is a major source of mesenchymal stem cells in 2001, scientists have been studying the use of adipose-derived stem cells (ASCs) for the treatment of various disorders including lesions of the articular cartilage. ASCs hold several advantages over autologous chondrocytes for cartilage repair, including but not limited to their anti-inflammatory effects, their multi-lineage differentiation potential, and their ability to form new cartilage in a defect. Whereas several investigations have been made in in vitro and animal models, there have been surprisingly little clinical studies on the intra-articular use of adipose-derived stem cells, despite their first isolation about a decade and a half ago. The few studies that have been conducted are encouraging. With approval for various stem cell therapies on the horizon, this review seeks to update the clinician and the researcher on the current state-of-the-art use of adipose-derived stem cells for the treatment of cartilage disorders and the regenerative engineering of cartilaginous tissue.