Arthroscopic osteochondral autograft transplantation in anterior cruciate ligament reconstruction: a preliminary clinical study

Autologous Osteochondral Grafts for Knee Osteochondral Diseases Result in Good Patient-Reported Outcomes in Patients Older Than 60 Years

Purpose

This study aims to examine the clinical autologous osteochondral grafts (AOG) outcomes for knee osteochondral diseases at operative ages >60 years, and to determine whether patients are able to sit straight in Japanese style after AOG.

Methods

All patients who underwent AOG for knee osteochondral diseases between November 2001 and April 2018 were retrospectively identified. The inclusion criteria were AOG only without osteotomy, operative ages between 60 and 79 years, >2 years of follow-up, and involved femorotibial angle between 169° and 179° (normal alignment). Patients who underwent osteotomy to improve knee alignment and patients with inflammatory diseases such as rheumatoid arthritis were excluded. The patients' knee symptoms and their clinical outcome were evaluated according to the criteria of the knee scoring system of the Japanese Orthopedic Association (JOA), International Knee Documentation Committee (IKDC) subjective score, and the ability of straight sitting in Japanese style.

Results

This study enrolled 57 cases and 60 knee joints during the study period. The follow-up ratio was 85.1%. Moreover, 14 men and 43 women and 29 right and 31 left knee joints were included in this study. The mean operative age and mean follow-up period were 67.8 years (range 60-76 years) and 81.1 months (range 24-167 months), respectively. In addition, the study involved 30 cases and 32 knee joints (60s group), and 27 cases and 28 knee joints (70s group). Moreover, 34 cases and 36 knee joints had osteonecrosis (ON group), and 23 cases and 24 knee joints had cartilage injury (CI group). The IKDC subjective and JOA scores in both the 60s and 70s groups showed significant differences: 2 years after AOG ＞at the follow-up period, ＞at the preoperative period. The scores in both the CI and ON groups showed similar significant differences. Furthermore, 8.3% and 53.5% of the patients could sit straight in Japanese style at the preoperative period and 2 years after AOG, respectively.

Conclusion

Even if the patient's operative age was >60 years, the AOG only for their knee osteochondral diseases had good clinical outcomes, including the ability to sit straight in Japanese style.

Level of Evidence

IV, Therapeutic case series Key words: autologous osteochondral grafts, aged patients, clinical outcome, knee joint, straight sitting in Japanese style.

Comparison of Knee Articular Cartilage Defect Size Between Measurements Obtained on Preoperative MRI Versus During Arthrotomy

Background

Treatment decisions for cartilage defects are often based on lesion size. Magnetic resonance imaging (MRI) is widely used to diagnose cartilage defects noninvasively; however, their size estimated from MRI may differ from defect sizes measured during arthrotomy, especially after debridement to healthy cartilage if undergoing autologous chondrocyte implantation.

Purpose/Hypothesis

The purpose of this study was to evaluate the reliability of 2 methods to assess knee cartilage defect size on preoperative MRI and determine their accuracy in predicting postdebridement defect sizes recorded during arthrotomy. It was hypothesized that defect size would be predicted more accurately by the total area of abnormal articular cartilage rather than the area of full-thickness cartilage loss as identified on MRI.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

This study included 64 patients (mean age, 41.8 ± 9.6 years) who underwent autologous cell therapy. Each patient received a 3-T MRI at 6.1 ± 3.0 weeks before cell implantation. Three raters, a radiologist, a surgeon, and a scientist, measured (1) the full-thickness cartilage defect area and (2) the total predicted abnormal cartilage area, identified by an abnormal signal on MRI. Interrater reliability was assessed using the intraclass correlation coefficient (ICC). Actual pre- and postdebridement defect sizes were obtained from intraoperative surgical notes. Postdebridement surgical measurements were considered the clinical reference standard and were compared with the radiologist's MRI measurements.

Results

Eighty-seven defects were assessed, located on the lateral (n = 8) and medial (n = 26) femoral condyle, trochlea (n = 17), and patella (n = 36). The interrater reliability of the cartilage defect measurements on MRI was good to excellent for the full-thickness cartilage defect area (ICC = 0.74) and the total predicted abnormal cartilage area (ICC = 0.78). The median full-thickness cartilage defect area on MRI underestimated the median postdebridement defect area by 78.3%, whereas the total predicted abnormal cartilage area measurement underestimated the postdebridement defect area by 14.3%.

Conclusion

Measuring the full-thickness cartilage defect area on MRI underestimated the area to treat, whereas measuring the total abnormal area provided a better estimate of the actual defect size for treatment.

Osteochondritis dissecans of the metacarpal head in a soldier treated with osteochondral autograft transplantation surgery: A case report

RATIONALE

Osteochondral autograft transplantation surgery (OATS) was introduced as a treatment for hand osteochondritis dissecans (OCD), and successful results were reported. However, the cartilage height of the donor plug has not yet been established compared with that of other joints. We present a case using OATS for OCD of the 3rd metacarpal (MCP) head that occurred in a soldier and the findings of magnetic resonance imaging (MRI) images taken at 12 weeks after surgery.

PATIENT CONCERNS

A 21-year-old male presented with a painful, swollen 3rd MCP joint in the right hand. He was a soldier and right-handed; in addition, he did not recall any traumatic events, nor had he taken any corticosteroid medications before. The patient was excluded from military training and underwent conservative treatment with medication and a brace in a military hospital for 3 months.

DIAGNOSIS

The patient was diagnosed with OCD due to avascular necrosis of the 3rd MCP head of the right hand through X-ray and MRI.

INTERVENTIONS

OATS was planned as a surgical treatment. Surgery uncovered a 10 × 10 mm2, isolated cartilage defect of the 3rd MCP head that had an irregular margin and a loose body. Using Arthrex OATS, a 10-mm diameter, 10-mm depth hole was made at the articular defect site, and an 11-mm diameter, 12-length plug was harvested from the left lateral femoral condyle. The donor plug was inserted into the prepared defect site with press-fit fixation.

OUTCOMES

At the last follow-up, the height of the articular cartilage had subsided with union on MRI 12 weeks after the surgery. However, the patient was asymptomatic with a normal range of motion of the right hand, and he returned to military training.

LESSONS

Although the joints of the hand are small and non-weight bearing, the level of articular cartilage of the donor plug was subsided in a follow-up MRI in our case. We suggest that the difference in cartilage thickness between the donor and the recipient might have been the cause of subsidence of the articular cartilage, and therefore, it may be helpful to transplant donors with similar thicknesses of articular cartilage.

Implant system for large osteochondral defects

Issues with current treatments for osteochondral defects such as mosaicplasty and autologous chondrocyte implantation (ACI) are lack of donor material, problems associated with donor sites, necessity of second surgical intervention and cell expansion, difficult site preparation and implant fitting to match the surrounding tissue. This study presents the development of a patient specific implant system for focal osteochondral defects that addresses these issues. Using computer aided design and manufacturing techniques, computed tomography scans are utilized to design the implant and templates that facilitate site preparation to allow for precise and easy implantation of the designed perfectly fitting tissue replacement. Functionality of the system and accurate restoration of a defect is demonstrated by digital before/after comparison and with a prototype. With the presented implantation system larger defects in curved joint surfaces can be restored to an optimal shape in an easier procedure than for instance mosaicplasty. The proposed system potentially allows for later replacement of worn implants.

Characteristics and Trends of the Most Cited Knee Surgery, Sports Traumatology, Arthroscopy Articles

Purpose

To compile and analyze the top 50 most frequently cited articles published in the Knee Surgery, Sports Traumatology, Arthroscopy journal.

Methods

Guidelines set by the Preferred Reporting Items for Systematic Reviews were used as the foundation for data collection and analysis. Scopus database was used to acquire the metric analyzed in the study. Once collected, the data was exported to an excel sheet in order to be organized, sorted, and analyzed in accordance with the metrics of interest.

Results

The United States was the most contributory nation with 14 publications, followed by Sweden with13 publications and Germany with eight publications. The most contributory institution was Umeå University in Vasterbottens, Sweden (8) followed by National Institute for Working Life in Stockholm, Sweden (7) and The University of Pittsburgh (5). Most publications were either Level II (19) or Level III (19) in terms of Level of Evidence. There was only one publication that was classified as a Level I paper.

Conclusion

The Journal of Knee Surgery, Sports Traumatology, and Arthroscopy has published very influential research papers as noted by the number of citations amassed by its most popular articles. KSSTA's top cited publications hail largely from major European and United States institutions and are composed of high-quality reports of mostly Level 2 and Level 3 evidence classifications.

Level of Evidence

3.

A systematic review on the potential value of synovial fluid biomarkers to predict clinical outcomes in cartilage repair treatments

OBJECTIVE

Multiple biochemical biomarkers have been previously investigated for the diagnosis, prognosis and response to treatment of articular cartilage damage, including osteoarthritis (OA). Synovial fluid (SF) biomarker measurement is a potential method to predict treatment response and effectiveness. However, the significance of different biomarkers and their correlation to clinical outcomes remains unclear. This systematic review evaluated current SF biomarkers used in investigation of cartilage degeneration or regeneration in the knee joint and correlated these biomarkers with clinical outcomes following cartilage repair or regeneration interventions.

METHOD

PubMed, Institute of Science Index, Scopus, Cochrane Central Register of Controlled Trials, and Embase databases were searched. Studies evaluating SF biomarkers and clinical outcomes following cartilage repair intervention were included. Two researchers independently performed data extraction and Quality Assessment of Diagnostic Accuracy Score 2 (QUADAS-2) analysis. Biomarker inclusion, change following intervention and correlation with clinical outcome was compared.

RESULTS

9 studies were included. Study heterogeneity precluded meta-analysis. There was significant variation in sampling and analysis. 33 biomarkers were evaluated in addition to microRNA and catabolic/anabolic ratios. Five studies reported on correlation of biomarkers with six biomarkers significantly correlated with clinical outcomes following intervention. However, correlation was only demonstrated in isolated studies.

CONCLUSION

This review demonstrates significant difficulties in drawing conclusions regarding the importance of SF biomarkers based on the available literature. Improved standardisation for collection and analysis of SF samples is required. Future publications should also focus on clinical outcome scores and seek to correlate biomarkers with progression to further understand the significance of identified markers in a clinical context.

REGISTRATION NUMBER

PROSPERO CRD42022304298. Study protocol available on PROSPERO website.

The 50 most-cited clinical articles in cartilage surgery research: a bibliometric analysis

PURPOSE

Articular cartilage lesions remain a challenge for orthopedic surgeons. The identification of the most important articles can help identifying the most influential techniques of the past, the current prevalent focus, and emerging strategies. The aim of this study was to identify milestones and trends in cartilage research.

METHODS

This study is a bibliometric analysis based on published articles. All citation count data included in the "Scopus database" were used to identify eligible studies up to December 2020. The 50 most-cited articles on cartilage surgery were ranked based on the citation count and analyzed regarding citation density and quality (Coleman score and RoB 2.0 tool). A further search was performed to identify the most promising clinical studies among the latest publications on cartilage surgery.

RESULTS

Different kinds of cartilage treatments were investigated in the 50 most-cited clinical articles. Regenerative techniques with chondrocytes were the most reported with a total of 23 articles, followed by microfracture technique in 17 articles and mosaicplasty or osteochondral autograft transplantation (OAT) in 11. Forty-five articles focused on the knee. A higher citation density was found in the most recent articles (p = 0.004). The study of the most promising landmarks of the most recent articles showed new cell-free or tissue engineering-based procedures and an overall increasing quality of the published studies.

CONCLUSION

This bibliometric analysis documented an increasing interest in cartilage surgery, with efforts toward high-quality studies. Over the years, the focus switched from reconstructive toward regenerative techniques, with emerging options including cell-free and tissue-engineering strategies to restore the cartilage surface.

LEVEL OF EVIDENCE

IV.

Autologous Osteochondral Grafts Result in Improved Clinical Outcomes in Patients With Early Knee Osteoarthritis

Purpose

To determine whether autologous osteochondral grafts improve clinical outcomes in early knee osteoarthritis (EKOA) and whether the grafts prevent progression of radiographic joint degeneration.

Methods

In this study, we identified patients older than 40 years with EKOA having no traumatic events, with grade 0, 1, or 2 on the Kellgren-Lawrence (KL) classification and more than grade 3 of cartilage degeneration according to the International Cartilage Repair Society scale. Recipient sites were as follows: 14 patellofemoral (PF3) joint, 18 medial femoral condyle (M1), and 6 lateral femoral condyle (L2). Japanese Orthopedic Association (JOA) score and International Knee Documentation (IKDC) subjective score (SUB) were examined as clinical outcomes.

Results

The study included 31 knees in 31 patients who underwent autologous osteochondral grafts for EKOA and more than two years follow-up. The sample included 15 men and 16 women. The mean operative age was 56.0 years, and the mean follow-up period was 76 months (range, 24-170 months). In the preoperative period, JOA and SUB were 73.9 and 49.5, respectively. At follow-up, the JOA and SUB scores were 93.7 and 84.5, respectively. The differences were statistically significant. Progression of KL classification occurred in 0% of the PF3 group, 17% of the L2 group, and 33% of the M1 group. The outcomes of the M1 group significantly became worse (P = .0381) than those of the L2 and the PF3 groups, and the PF3 group significantly maintained good clinical outcomes (P = .0334).

Conclusion

Autologous osteochondral grafts for degenerated cartilage improved clinical outcomes of EKOA even if the recipient had cartilage degeneration, and not trauma. The PF3 group maintained significantly good clinical outcomes, and the M1 group became significantly worse.

Midterm Outcomes of Autologous Osteochondral Graft Transplantation Only in the Femoral Condyle without Treating the Tibial Plateau with Subchondral Bone Exposed

OBJECTIVE

This study aimed to examine the midterm clinical outcomes of autologous osteochondral grafts (AOG) that were performed in the femoral condyle without treating the tibial plateau with subchondral bone exposed, and to compare these outcomes with those of AOG used in patients with osteoarthritis (lateral type or medial type) or osteonecrosis.

DESIGN

The study included 6 men and 16 women and 11 right knees and 11 left knees. The mean operative age was 56.0 years (range, 21-76 years), and the mean follow-up period was 98.4 months (range, 60-164 months). Six patients had lateral type osteoarthritis (OAL), 7 had medial type osteoarthritis (OAM), and 9 had osteonecrosis (ON). The patients' knee symptoms as their clinical outcome were evaluated using the knee scoring system of the Japanese Orthopedic Association (JOA), and the International Knee Documentation Committee (IKDC) subjective score.

RESULTS

The postoperative clinical outcomes of the OAL and ON group were significantly better than their preoperative clinical scores and remained the same until the final follow-up. However, the clinical outcomes of OAM improved 2 years after AOG, but eventually decreased thereafter. The number of worse cases in the OAM group was significantly larger than those in the OAL and ON groups.

CONCLUSION

In these procedures, the postoperative clinical outcomes of the OAL and ON groups were significantly better than their preoperative clinical scores and were maintained for about 8 years. However, the clinical outcomes of OAM improved until 2 years after AOG, but eventually decreased thereafter.

The Top 50 Most-Cited Knee Arthroscopy Studies

Purpose

To objectively identify the 50 most influential studies in knee arthroscopy and provide an analysis of their key characteristics.

Methods

The Clarivate Analytics Web of Knowledge database was used to gather data and metrics of knee arthroscopy research. The search list was sorted by the number of citations, and articles were included or excluded based on relevance to knee arthroscopy. The information extracted for each article included author name, publication year, country of origin, journal name, article type, and the level of evidence.

Results

For these 50 studies, the total number of citations was calculated to be 12,168, with an average of 243.4 citations per paper. The most-cited article was cited 1,220 times. The 50 studies included in this analysis were published between 1972 and 2013. All 50 articles were published in English and came from 10 different orthopaedic journals. The United States was responsible for the majority of articles (n = 26); however, many other countries were represented. The most prevalent study designs were case series (n = 20).

Conclusions

The 50 most influential articles in knee arthroscopy were cited a total of 12,168 times. The study designs most commonly used were case series and cohort studies. This article serves as a reference to direct orthopaedic practitioners to the 50 most influential studies in knee arthroscopy. We hope that these 50 studies and the analysis we provide help health care professionals efficiently assess consensus, trends, and needs within the field.

Clinical Relevance

This analysis of the 50 most influential studies in knee arthroscopy will provide medical students, residents, fellows, and attending physicians with a comprehensive inventory and citation analysis of the most impactful academic contributions to one of the most important fields within orthopaedic surgery.

The Top 100 Most-Cited Articles on Arthroscopy: Most Popular Topic Is Rotator Cuff Rather Than Cartilage in the Last 5 Years

PURPOSE

To highlight the characteristics of the 100 most-cited articles on arthroscopy and provide the variation trend of citation rate among the top 25 articles in the past 9 years. We further analyzed the topics of interest in the past or currently.

METHODS

The Thomson ISI Web of Science database was used to identify arthroscopy-related articles that were published from 1950 to March 31, 2020. The 100 most-cited articles were selected for further analysis. In addition, author key words of the articles that published in the recent 5 years were further analyzed.

RESULTS

Mean of citations was 433.59 ± 400.73. The publication year ranged from 1980 to 2013. Most articles were focused on cartilage lesions and treatments (26%). A large proportion of articles were published in the 2000s (61%). Arthroscopy-the Journal of Arthroscopic and Related Surgery (23%) was the most popular journal. One half of the articles originated from the United States. The most prolific institution and first author were the Steadman Philippon Research Institute (5%) and Marc J. Philippon (4%), respectively. Most of the articles were Level IV evidence (33%). The citation rate increased by 131% from the previous top 25 articles published in 2011. A growth trend can be seen in the citation density over time. "Shoulder" (occurrences = 535) was the most used joint key word and "rotator cuff" (342) was the most used key word of research objective in the last 5 years, whereas "cartilage" only occurred 262 times.

CONCLUSIONS

Based on bibliometric analysis of the 100 most-cited articles on arthroscopy combined with network analysis of the whole articles that published in the recent 5 years, the topic of most interest in the recent 5 years was rotator cuff rather than cartilage. The number of citations among the 25 most-cited articles is growing rapidly and has at least doubled in size on average in the past 9 years. Citation density among the 100 most-cited articles on arthroscopy has seen a growth trend.

CLINICAL RELEVANCE

This article clarifies the characteristics of the 100 most-cited papers and provides guidance on the topics of interest in the past or currently as a roadmap for future research on arthroscopy.

Bilateral osteochondral defects of the patellae in an 11-year-old girl

Osteochondral defect or osteochondritis dissecans (OCD) of the knee usually affects young, active populations. It is a challenging diagnosis as patients typically present with poorly localised activity-related pain, which is non-specific and covers many differentials. We present an active 11-year-old girl with bilateral osteochondral defects of the patellae: a rare clinical disorder which was affecting her sporting activities. She had a 12-month history of bilateral anterior knee pain before the diagnosis was achieved with appropriate imaging. Her pain significantly improved with activity modification and physiotherapy. Follow-up will require outpatient clinic assessment and imaging to determine if non-operative management continues to be successful or surgery may be required. This case report emphasises the importance of appropriate high index of suspicion when managing patients with non-specific knee pain. It also demonstrates the importance of judicious use of imaging to avoid a missed or delayed diagnosis.

Articular Cartilage Repair in the Knee: Postoperative Imaging

Diagnostic and therapeutic advancements have improved clinical outcomes for patients with focal chondral injuries of the knee. An increased number and complexity of surgical treatment options have, in turn, resulted in a commensurate proliferation of patients requiring postoperative evaluation and management. In addition to patient-reported clinical outcomes, magnetic resonance imaging (MRI) offers clinicians with noninvasive, objective data to assist with postoperative clinical decision making. However, successful MRI interpretation in this setting is clinically challenging; it relies upon an understanding of the evolving and procedure-specific nature of normal postoperative imaging. Moreover, further research is required to better elucidate the correlation between MRI findings and long-term clinical outcomes. This article focuses on how specific morphologic features identified on MRI can be utilized to evaluate patients following the most commonly performed cartilage repair surgeries of the knee.

Effects of the material properties of a focal knee articular prosthetic on the human knee joint using computational simulation

BACKGROUND

Localized cartilage defects are related to joint pain and reduced function to the development of osteoarthritis. The mechanical properties of the implant for treatment do influence its longevity. Therefore, we aimed to evaluate the effect of material properties' variations of anatomically shaped focal knee implants in the knee joint using numerical finite element analysis.

METHODS

Computational simulations were performed for different cases including an intact knee, a knee with a focal cartilage defect, and a knee fitted with a focal articular prosthetic having three distinct mechanical properties: cobalt-chromium, pyrolytic carbon, and polyethylene. Femoral cartilage, tibial cartilage, and menisci contact pressures were evaluated under the load. In addition, bone stress was evaluated to investigate the stress shielding effect.

RESULTS

Compared with the intact model, the contact stress of the focal implant model was increased; on the femoral lateral cartilage by 14%, on medial and lateral tibial cartilages by nine percent and 10%, on medial and lateral menisci by 23% and 20%. In contrast, the focal implant model had no effect on the menisci but contact stress on the tibial cartilage increased compared with the intact model. The BioPoly model showed the lowest contact stress on femoral and tibial cartilages. Additionally, the cobalt-chromium model showed the lowest bone stress that improved the load-sharing effect.

CONCLUSIONS

The results suggested that implant material properties are an important parameter in the design of a focal implant. The polyethylene model potentially restored the intact knee contact mechanics and it reduced the risk of physiological damage to the articular cartilage.

Biological responses to individualized small titanium implants for the treatment of focal full-thickness knee cartilage defects in a sheep model

BACKGROUND

The present study aimed to evaluate the functional, radiological and histological outcome of a customized focal implant for the treatment of focal full-thickness cartilage defects in sheep.

METHODS

The study used magnetic resonance imaging data as the basis for construction of the titanium implant using a three-dimensional printing technique. This was then placed on the medial condyle of the knee joint in eight sheep and left in place in vivo over a period of six months. Following euthanasia, the local biological response was analyzed using micro-computed tomography, light microscopy and histological evaluation (International Cartilage Repair Society (ICRS) score). The variables were analyzed using a generalized linear mixed model. Odds ratios were given with 95% confidence intervals.

RESULTS

The osseointegration rate was 62.1% (SD 3.9%). All implants were prone to the neighboring cartilage bed (4.4-1096.1 μm). Using the IRCS score, the elements 'surface', 'matrix', 'cell distribution' and 'cell population' all showed pathological changes on the operated side, although these did not correlate with implant elevation. On average, a difference of 0.7 mm (±2 mm) was found between the digitally planned implant and the real implant.

CONCLUSIONS

As a result of imprecise segmentation and difficult preparation conditions at the prosthesis bed, as well as changes at the surface of the implant over the operational lifetime of the prosthesis, it must be stated that the approach implemented here of using a customized implant for the treatment of focal full-thickness cartilage defects at the knee did not meet our expectations.

Clinical outcome after mosaicplasty of knee articular cartilage defects of patellofemoral joint versus tibiofemoral joint

Background

The purpose was to investigate survival of cartilage repair in the knee joint by osteochondral autograft transfer stratified by location of the lesion; patellofemoral joint (N = 26) versus the medial or lateral femoral condyles (N = 58).

Methods

For survival analyses, “failure” was defined as the event of a patient reporting a poor Lysholm score (below 65 points) or undergoing a knee replacement procedure.

Results

The survival distribution was not significantly different between the patellofemoral joint and the tibiofemoral joint groups.

Conclusions

The current study suggest that similar long-term outcome can be expected after OAT procedures for the patellofemoral or tibiofemoral joint.

Level of evidence

Therapeutic study, Level III.

The Effect of Articular Cartilage Focal Defect Size and Location in Whole Knee Biomechanics Models

Articular cartilage focal defects are common soft tissue injuries potentially linked to osteoarthritis (OA) development. Although several defect characteristics likely contribute to osteoarthritis, their relationship to local tissue deformation remains unclear. Using finite element models with various femoral cartilage geometries, we explore how defects change cartilage deformation and joint kinematics assuming loading representative of the maximum joint compression during the stance phase of gait. We show how defects, in combination with location-dependent cartilage mechanics, alter deformation in affected and opposing cartilages, as well as joint kinematics. Small and average sized defects increased maximum compressive strains by approximately 50% and 100%, respectively, compared to healthy cartilage. Shifts in the spatial locations of maximum compressive strains of defect containing models were also observed, resulting in loading of cartilage regions with reduced initial stiffnesses supporting the new, elevated loading environments. Simulated osteoarthritis (modeled as a global reduction in mean cartilage stiffness) did not significantly alter joint kinematics, but exacerbated tissue deformation. Femoral defects were also found to affect healthy tibial cartilage deformations. Lateral femoral defects increased tibial cartilage maximum compressive strains by 25%, while small and average sized medial defects exhibited decreases of 6% and 15%, respectively, compared to healthy cartilage. Femoral defects also affected the spatial distributions of deformation across the articular surfaces. These deviations are especially meaningful in the context of cartilage with location-dependent mechanics, leading to increases in peak contact stresses supported by the cartilage of between 11% and 34% over healthy cartilage.

Osteochondral Tissue Regeneration Using a Tyramine-Modified Bilayered PLGA Scaffold Combined with Articular Chondrocytes in a Porcine Model

Repairing damaged articular cartilage is challenging due to the limited regenerative capacity of hyaline cartilage. In this study, we fabricated a bilayered poly (lactic-co-glycolic acid) (PLGA) scaffold with small (200–300 μm) and large (200–500 μm) pores by salt leaching to stimulate chondrocyte differentiation, cartilage formation, and endochondral ossification. The scaffold surface was treated with tyramine to promote scaffold integration into native tissue. Porcine chondrocytes retained a round shape during differentiation when grown on the small pore size scaffold, and had a fibroblast-like morphology during transdifferentiation in the large pore size scaffold after five days of culture. Tyramine-treated scaffolds with mixed pore sizes seeded with chondrocytes were pressed into three-mm porcine osteochondral defects; tyramine treatment enhanced the adhesion of the small pore size scaffold to osteochondral tissue and increased glycosaminoglycan and collagen type II (Col II) contents, while reducing collagen type X (Col X) production in the cartilage layer. Col X content was higher for scaffolds with a large pore size, which was accompanied by the enhanced generation of subchondral bone. Thus, chondrocytes seeded in tyramine-treated bilayered scaffolds with small and large pores in the upper and lower parts, respectively, can promote osteochondral regeneration and integration for articular cartilage repair.

[Operative treatment of cartilage lesions]

Cartilage damage is often associated with pain, reduced quality of life and decreased physical performance. In addition, even small cartilage lesions can lead to osteoarthritis. Since young active people are particularly affected, the correct treatment of cartilage damage plays an important role. Operative treatment includes bone marrow-stimulating procedures with or without a matrix, cell-based procedures and osteochondral graft transplantation. The choice of the best procedure depends on the localization, the size and the extent of the cartilage damage. In addition, especially in the treatment of cartilage damage to the lower limbs, the leg axis and loading relationships should be taken into account and possibly treated as well as additional joint instabilities. The following article gives an overview of the available surgical treatment possibilities as well as the correct indications and implementation. It also gives a brief projection of possible further treatment options associated with stem cells.

Influence of Meniscal and Chondral Lesions on Patient-Reported Outcomes After Primary Anterior Cruciate Ligament Reconstruction at 2-Year Follow-up

Background:

Meniscal and chondral lesions are commonly associated with anterior cruciate ligament (ACL) tears, and these lesions may play a role in patient outcomes after ACL reconstruction.

Purpose:

To determine the effects of the presence and location of meniscal and chondral lesions at the time of ACL reconstruction on patient-reported outcomes at a minimum 2-year follow-up.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with no prior knee surgery who underwent primary ACL reconstruction by a single surgeon between 2010 and 2014 were included in this study. Those meeting inclusion criteria were divided into the following groups based on the arthroscopic diagnosis: patients without concomitant meniscal or chondral lesions, patients with isolated meniscal lesions, patients with isolated chondral lesions, and patients with both chondral and meniscal lesions. Patient-reported outcomes (Short Form–12 [SF-12] physical component summary [PCS] and mental component summary [MCS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Lysholm scale) were assessed at a minimum of 2 years from the index surgery.

Results:

A total of 151 patients met the inclusion criteria and were included in the study. The mean age at the time of surgery was 36.2 years (range, 14-73 years), and the mean follow-up was 3.2 years (range, 2.0-5.6 years). At the time of surgery, 33 (22%) patients had no concomitant lesions and served as the control group, 63 (42%) patients had isolated meniscal lesions, 21 (14%) patients had isolated chondral lesions, and 34 (22%) patients had both chondral and meniscal lesions. There was significant improvement in all outcome scores postoperatively for the 3 groups (P < .05 for all outcome scores). The presence of a meniscal tear and laterality of the meniscal lesion did not have a negative effect on any postoperative outcome scores. Patients with isolated chondral lesions had significantly lower postoperative WOMAC scores compared with patients without chondral lesions (P < .05). No significant differences were found for all other scores. Patients with patellofemoral chondral lesions had significantly lower postoperative SF-12 PCS and Lysholm scores than patients with tibiofemoral chondral lesions (P < .05).

Conclusion:

Patients with ACL tears achieved improved functional scores at a mean 3.2 years after ACL reconstruction. While meniscal lesions did not affect postoperative outcomes in the short term, chondral lesions were identified as a predictor for worse outcomes.

Biomaterials for articular cartilage tissue engineering: Learning from biology

Articular cartilage is commonly described as a tissue that is made of up to 80% water, is devoid of blood vessels, nerves, and lymphatics, and is populated by only one cell type, the chondrocyte. At first glance, an easy tissue for clinicians to repair and for scientists to reproduce in a laboratory. Yet, chondral and osteochondral defects currently remain an open challenge in orthopedics and tissue engineering of the musculoskeletal system, without considering osteoarthritis. Why do we fail in repairing and regenerating articular cartilage? Behind its simple and homogenous appearance, articular cartilage hides a heterogeneous composition, a high level of organisation and specific biomechanical properties that, taken together, make articular cartilage a unique material that we are not yet able to repair or reproduce with high fidelity. This review highlights the available therapies for cartilage repair and retraces the research on different biomaterials developed for tissue engineering strategies. Their potential to recreate the structure, including composition and organisation, as well as the function of articular cartilage, intended as cell microenvironment and mechanically competent replacement, is described. A perspective of the limitations of the current research is given in the light of the emerging technologies supporting tissue engineering of articular cartilage.

STATEMENT OF SIGNIFICANCE

The mechanical properties of articular tissue reflect its functionally organised composition and the recreation of its structure challenges the success of in vitro and in vivo reproduction of the native cartilage. Tissue engineering and biomaterials science have revolutionised the way scientists approach the challenge of articular cartilage repair and regeneration by introducing the concept of the interdisciplinary approach. The clinical translation of the current approaches are not yet fully successful, but promising results are expected from the emerging and developing new generation technologies.

Advances for Treatment of Knee OC Defects

Osteochondral (OC) defects are prevalent among young adults and are notorious for being unable to heal. Although they are traumatic in nature, they often develop silently. Detection of many OC defects is challenging, despite the criticality of early care. Current repair approaches face limitations and cannot provide regenerative or long-standing solution. Clinicians and researchers are working together in order to develop approaches that can regenerate the damaged tissues and protect the joint from developing osteoarthritis. The current concepts of tissue engineering and regenerative medicine, which have brought many promising applications to OC management, are overviewed herein. We will also review the types of stem cells that aim to provide sustainable cell sources overcoming the limitation of autologous chondrocyte-based applications. The various scaffolding materials that can be used as extracellular matrix mimetic and having functional properties similar to the OC unit are also discussed.

Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched-Group Analysis With Minimum 2-Year Follow-Up

PURPOSE

To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up.

METHODS

After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm² in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure.

RESULTS

A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups.

CONCLUSIONS

OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Clinical Outcomes of Donor Sites After Osteochondral Graft Harvest From Healthy Knees

Background:

The use of autologous osteochondral grafts has become popular in the treatment of small, isolated, well-contained articular cartilage defects. However, donor site morbidity is a problem, and few reports are available of donor site morbidity after mosaicplasty.

Purpose:

To examine the clinical outcomes of donor sites after osteochondral grafts from healthy knees.

Study Design:

Case series; Level of evidence, 4.

Methods:

Between September 1997 and September 2011, there were 40 patients (40 knees; 32 men, 8 women; 31 right knees, 9 left knees) with asymptomatic osteochondral graft donor sites used for autologous transfer; all had a follow-up period of >2 years. The mean patient age at surgery was 21.0 years (range, 12-58 years). The recipient sites included the elbow (n = 28), contralateral knee (n = 5), and ankle (n = 7). The mean diameter of the grafted plugs was 7.5 mm (range, 4.5-9 mm), and the mean number of grafted plugs was 2.2 (range, 1-3). At a mean follow-up of 43.1 months (range, 24-177 months), knee symptoms, return to sport, ability to sit straight in Japanese style, and radiological changes of the patellofemoral joint were evaluated. Whether operative age, follow-up period, and diameter or number of the grafted plugs were risk factors was analyzed statistically. Significance was defined as P < .05.

Results:

Thirty-four patients had no knee symptoms, and 4 patients had occasional mild knee pain. Two patients underwent reoperation for arthrofibrosis and not for cartilage defect. Twenty-seven patients had complete return to sports, and 32 patients could sit straight; donor site morbidity was not the cause of failure to return to sports or inability to sit straight. The radiological changes became worse in 3 patients, and the risk factor for degenerative change was older operative age.

Conclusion:

When osteochondral plugs were obtained from healthy knees, 34 patients (85%) were asymptomatic at follow-up. No donor site defects required surgical intervention due to persistent symptoms.

Functional outcomes after patellar autologous osteochondral transplantation

PURPOSE

The aim of the present study was to assess clinical evaluation of patients who underwent autologous osteochondral transplantation of the patella.

METHODS

This prospective study assessed outcomes of 20 patients who underwent patellar autologous osteochondral transplantation at four time-points: preoperatively, 3 days, 6 months, and 2 years after surgery. The following outcomes were assessed at each time-point: pain (VAS), gait, swelling, trophic status, muscle strength, patellar mobility, and range of motion. The Tegner scale was also applied for each time-point.

RESULTS

All parameters improved, except for patellar mobility, which did not show any change. Pain score decreased from 7.1 (SD 2.3) to 2.4 (SD 2.6) at the 2-year assessment; limping decreased from 70 % before surgery to 15 % 2 years later; swelling scores decreased from an average of 1.8 (SD 0.8) 3 days after surgery to 0.5 (SD 0.7) at the 2-year assessment; muscle strength increased from 3.9 (SD 0.8) to 4.7 (SD 0.7) points at final follow-up; and the range of motion increased from 84 (SD 16.2) to 132 (SD 10.7) degrees 2 years later. Tegner score before surgery ranged from 0 to 5, and after 2 years, it ranged from 5 to 9.

CONCLUSION

Autologous osteochondral transplantation for the treatment of patellar chondral lesion was associated with significant improvement in pain, gait, swelling, and range of motion 2 years after surgery, achieving scores similar to uninjured knees. Most of them were able to return to sports activity after 6 months (recreational level) and 2 years (competitive level).

LEVEL OF EVIDENCE

IV.

Anconeus Muscle-Pedicle Bone Graft With Periosteal Coverage for Osteochondritis Dissecans of the Humeral Capitellum

Background:

Treatment of advanced osteochondritis dissecans (OCD) of the capitellum is controversial, especially in moderate-sized lesions.

Purpose:

To establish a treatment algorithm for capitellum OCD, we tried to determine the utility of and problems associated with anconeus muscle-pedicle bone graft with periosteal coverage (ABGP) for the treatment of moderate-sized articular OCD defects of the capitellum.

Study Design:

Case series; Level of evidence, 4.

Methods:

According to our protocol for elbow OCD, 16 patients (15 males, 1 female; age range, 12-17 years; mean age, 14.4 years) with a moderate-sized OCD lesion of the humeral capitellum were treated with ABGP. All patients had a full-thickness, unstable OCD lesion that was 10 to 15 mm in diameter. Clinical results and postoperative images, including radiographs and magnetic resonance imaging (MRI), were evaluated at a mean follow-up of 31 months (range, 24-66 months).

Results:

All but 1 patient had functional improvement after the procedure and returned to previous sporting activities within 6 months. One female patient needed 1 year for functional recovery due to development of postoperative chronic regional pain syndrome (CRPS). Two patients required additional surgery, including shaving of the protruding cartilage, and they returned to their previous level of activity. Mean arc of range of flexion-extension motion was 117° preoperatively and 129° at follow-up (P = .031). Mean elbow function as assessed with the clinical rating system of Timmerman and Andrews was 136 preoperatively and 186 at follow-up (P = .00012). Bony union of the graft as demonstrated by trabecular bone bridging on radiography was obtained within 3 months in all patients. Postoperative MRI was examined for 14 patients at 6 to 12 months after the procedure; the MRIs showed near-normal articular surface integrity in 9 of the 14 patients (64%) and underlying bony structure in 10 of the 14 patients (71%).

Conclusion:

Improvement after ABGP was obtained within 6 months in all except 1 patient, who developed CRPS. Postoperative radiography and MRI revealed near-normal articular surface integrity or underlying bony structure. This procedure is useful as a surgical option for a moderate-sized articular OCD lesion in the elbow.

Surgical treatments of cartilage defects of the knee: Systematic review of randomised controlled trials

BACKGROUND

The aim of this systematic review was to identify high quality randomised controlled trials (RCTs) and to provide an update on the most appropriate surgical treatments for knee cartilage defects.

METHODS

Two reviewers independently searched three databases for RCTs comparing at least two different treatment techniques for knee cartilage defects. The search strategy used terms mapped to relevant subject headings of MeSH terms. Strict inclusion and exclusion criteria were used to identify studies with patients aged between 18 and 55 years with articular cartilage defects sized between one and 15cm². Risk of bias was performed using a Coleman Methodology Score. Data extracted included patient demographics, defect characteristics, clinical outcomes, and failure rates.

RESULTS

Ten articles were included (861 patients). Eight studies compared microfracture to other treatment; four to autologous chondrocyte implantation (ACI) or matrix-induced ACI (MACI); three to osteochondral autologous transplantation (OAT); and one to BST-Cargel. Two studies reported better results with OAT than with microfracture and one reported similar results. Two studies reported superior results with cartilage regenerative techniques than with microfracture, and two reported similar results. At 10years significantly more failures occurred with microfracture compared to OAT and with OAT compared to ACI. Larger lesions (>4.5cm²) treated with cartilage regenerative techniques (ACI/MACI) had better outcomes than with microfracture.

CONCLUSIONS

Based on the evidence from this systematic review no single treatment can be recommended for the treatment of knee cartilage defects. This highlights the need for further RCTs, preferably patient-blinded, using an appropriate reference treatment or a placebo procedure.

Intermediate- to Long-Term Results of Combined Anterior Cruciate Ligament Reconstruction and Autologous Chondrocyte Implantation

BACKGROUND

Cartilage injury associated with anterior cruciate ligament (ACL) ruptures is common; however, relatively few reports exist on concurrent cartilage repair with ACL reconstruction. Autologous chondrocyte implantation (ACI) has been utilized successfully for treatment of moderate to large chondral defects.

HYPOTHESIS

ACL insufficiency with relatively large chondral defects may be effectively managed with concurrent ACL reconstruction and ACI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients undergoing concurrent ACL primary or revision reconstruction with ACI of single or multiple cartilage defects were prospectively evaluated for a minimum 2 years. Pre- and postoperative outcome measures included the modified Cincinnati Rating Scale (MCRS), Western Ontario and McMaster Universities Osteoarthritis Index, visual analog pain scales, and postsurgery satisfaction surveys. ACI graft failure or persistent pain without functional improvement were considered treatment failures.

RESULTS

Twenty-six patients were included, with 13 primary and 13 revision ACL reconstructions performed. Mean defect total surface area was 8.4 cm², with a mean follow-up of 95 months (range, 24-240 months). MCRS improved from 3.62 ± 1.42 to 5.54 ± 2.32, Western Ontario and McMaster Universities Osteoarthritis Index from 45.31 ± 17.27 to 26.54 ± 17.71, and visual analog pain scale from 6.19 ± 1.27 to 3.65 ± 1.77 (all Ps <.001). Eight patients were clinical failures, 69% of patients were improved at final follow-up, and 92% stated they would likely undergo the procedure again. No outcome correlation was found with regard to age, body mass index, sex, defect size/number, follow-up time, or primary versus revision ACL reconstruction. In subanalysis, revision ACL reconstructions had worse preoperative MCRS scores and greater defect surface areas. However, revision MCRS score improvements were greater, resulting in similar final functional scores when compared with primary reconstructions.

CONCLUSION

Challenging cases of ACL tears with large chondral defects treated with concurrent ACL reconstruction and ACI can lead to moderately improved pain and function at long-term follow-up. Factors associated with clinical failure are not clear. When combined with ACI, patients undergoing revision ACL reconstructions have worse function preoperatively compared with those undergoing primary reconstructions but have similar final outcomes.

Good short- to medium-term results after osteochondral autograft transplantation (OAT) in middle-aged patients with focal, non-traumatic osteochondral lesions of the knee

BACKGROUND

Osteochondral autograft transplantation (OAT) offers the opportunity to repair cartilaginous defects by restoring hyaline cartilage anatomy. Encouraging results have been reported in patients suffering from acute knee trauma or osteochondritis dissecans. Patients with focal chronic, non-traumatic osteochondral (FCNO) lesions of the knee, however, have rarely been the subject of investigation. Some authors even consider higher age as contraindications to OAT.

OBJECTIVES

To assess the short- to medium-term outcomes of OAT in middle-aged patients with FCNO lesions of the knee and to identify predictors of clinical outcome.

HYPOTHESIS

Filling FCNO defects with autologous osteochondral grafts should restore the congruency of the middle-aged knee joint and thereby reduce pain and loss of function on the one hand, and increase quality of life on the other hand.

METHODS

One hundred and twelve patients (48.01±1.12yrs) with FCNO of the knee were assessed before OAT and 26.2±0.24 months after surgery. Clinical outcome was measured by WOMAC Index and the Visual Analogue Scale (VAS) for pain.

RESULTS

Pain (pre-OAT VAS vs. post-OAT VAS: 7.14±0.19 vs. 3.74±0.26, P<0.001) was reduced and quality of life (pre-OAT WOMAC vs. post-OAT WOMAC: 134.88±5.84 vs. 65.92±5.34, P<0.001) improved. Retropatellar defects were associated with poor outcome, while overall surface and number of cylinders were not.

DISCUSSION

Middle-aged patients with FCNO of the knee also profit from OAT at a short follow-up.

LEVEL OF EVIDENCE

IV. Mono-centric, prospective clinical series.

Real-Time 3D Visualization and Navigation Using Fiber-Based Endoscopic System for Arthroscopic Surgery

Three-dimensional (3D) navigation using a computer-assisted technique is being increasingly performed in minimally invasive surgical procedures because it can provide stereoscopic information regarding the operating field to the surgeon. In this paper, the development of a real-time arthroscopic system utilizing an endoscopic camera and optical fiber to navigate a normal vector for a reconstructed knee joint surface is described. A specific navigation approach suitable for use in a rendered surface was presented in extenso. A small-sized endoscopic tube was utilized arthroscopically on a cadaveric knee joint to show the potential application of the developed system. Experimental results of underwater navigation on a synthetic knee joint showed that our system allows for a higher accuracy than a freehand technique. The mean angle of navigation for the proposed technique is 9.5circ (range, 5circ to 17circ; SD, 2.86circ) versus 14.8circ (range, 6circ to 26circ; SD, 7.53circ) and 12.6circ (range, 4circ to 17circ; SD, 3.98circ) for two sites using a freehand technique.

Serial Changes of the Cartilage in Recipient Sites and Their Mirror Sites on Second-Look Imaging After Mosaicplasty

BACKGROUND

It has been reported that the short-term results of mosaicplasty are good, but there have been no reports of the serial cartilage changes in the recipient sites and their mirror sites for mosaicplasty.

PURPOSE

To examine the serial changes in cartilage in the recipient sites and their mirror sites using second-look imaging.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 33 patients (37 knees, 40 sites) underwent mosaicplasty and second-look arthroscopy at a single institution over a 7-year period. There were 14 men and 19 women (12 right knees and 25 left knees). The recipient sites were the patella (n = 3), trochlea (n = 7), medial femoral condyle (n = 21), and lateral femoral condyle (n = 9). The mean patient age at surgery was 38.3 years; the mean period from mosaicplasty to second-look arthroscopy was 15.4 months; and the mean follow-up period was 34.9 months (range, 24-65 months). The results of second-look arthroscopy at the recipient site were categorized as cartilage with a smooth surface (group S) and fibrillation or an irregular surface (group I), and results of second-look arthroscopy at the mirror site were categorized as worse (group W), improved (group E), and unchanged (group U).

RESULTS

There were 30 sites in group S, 10 sites in group I, 3 sites in group W, 4 sites in group E, and 33 sites in group U. The age at operation was significantly greater in group S than in group I. There was a significant correlation between group S and groups E and U. The clinical outcome was significantly worse in group W when compared with groups E and U.

CONCLUSION

If a smooth surface was seen in the recipient site during second-look arthroscopy, the cartilage degeneration in its mirror site did not become worse after mosaicplasty.

Gel-type autologous chondrocyte implantation for cartilage repair in patients with prior ACL reconstruction: A retrospective two year follow-up

PURPOSE

To describe the early patient-reported outcomes of articular cartilage repair in patients with pain due to grade III or IV articular cartilage defects after prior anterior cruciate ligament (ACL) reconstruction.

METHODS

Nineteen patients underwent a gel-type autologous chondrocyte implantation (GACI) procedure after ACL reconstruction. Median timeframe between ACL reconstruction and GACI procedure was 52 months (range 16 to 369). The average age at chondrocyte implantation was 35 (standard deviation (SD) eight) years and average cumulative articular cartilage defect size was nine (SD four) square centimeter. Outcome was assessed prior to the GACI procedure and two years after GACI using the International Knee Documentation Committee (IKDC) score and the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Two year post-GACI scores showed a statistically significant improvement of IKDC (13, SD 22, p=.02) and KOOS quality of life (18, SD 27, p=.01) compared to the pre-GACI scores. The other KOOS domains did improve, but not statistically significant. Seven (37%) patients underwent reoperation after the GACI.

CONCLUSION

Patients with prior ACL reconstruction and suffering from ongoing pain associated with cartilage defects can benefit from cartilage repair with GACI.

Effect on Patient-Reported Outcomes of Debridement or Microfracture of Concomitant Full-Thickness Cartilage Lesions in Anterior Cruciate Ligament-Reconstructed Knees: A Nationwide Cohort Study From Norway and Sweden of 357 Patients With 2-Year Follow-up

BACKGROUND

The treatment of concomitant cartilage lesions in anterior cruciate ligament (ACL)-injured knees is debatable.

PURPOSE

To evaluate the effect of debridement or microfracture (MF) compared with no treatment of concomitant full-thickness (International Cartilage Repair Society [ICRS] grades 3-4) cartilage lesions on patient-reported outcomes after ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Six hundred forty-four patients who underwent primary unilateral ACL reconstruction and had a concomitant full-thickness cartilage lesion treated simultaneously by debridement (n = 129) or MF (n = 164), or underwent no treatment (n = 351) of the cartilage lesion, registered in the Norwegian and Swedish National Knee Ligament Registries from 2005 to 2008 were included. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to measure patient-reported outcomes. At a mean follow-up of 2.1 ± 0.2 years after surgery, 357 (55%) patients completed the KOOS. Linear regression analyses were used to evaluate the effect of debridement or MF on the KOOS.

RESULTS

No significant effects of debridement were detected in the unadjusted or adjusted regression analyses on any of the KOOS subscales at 2-year follow-up. The MF treatment of the cartilage lesions had significant negative effects at 2-year follow-up on the KOOS Sport and Recreation (Sport/Rec) (regression coefficient [β] = -8.9; 95% confidence interval [CI], -15.1 to -1.5) and Knee-Related Quality of Life (QoL) (β = -8.1; 95% CI, -14.1 to -2.1) subscales in the unadjusted analyses. When adjusting for confounders, MF had significant negative effects on the same KOOS subscales of Sport/Rec (β = -8.6; 95% CI, -16.4 to -0.7) and QoL (β = -7.2; 95% CI, -13.6 to -0.8). For the remaining KOOS subscales of Pain, Symptoms, and Activities of Daily Living, there were no significant unadjusted or adjusted effects of MF.

CONCLUSION

MF of concomitant full-thickness cartilage lesions showed adverse effects on patient-reported outcomes at 2-year follow-up after ACL reconstruction. Debridement of concomitant full-thickness cartilage lesions showed neither positive nor negative effects on patient-reported outcomes at 2-year follow-up after ACL reconstruction.

Osteochondral autografts

The healing potential for articular cartilage lesions is limited due to many physiological, local and mechanical factors. Spontaneous healing of partial- and full-thickness lesions is slow, and subsequent tissue response is usually not durable. In symptomatic, and high-demand, patients, a definitive treatment modality must be offered which allows for a sustained recovery with minimal debilitation. Injuries, which damage the subchondral bone, heal with the formation of fibrocartilage. This tissue fails long-term survival because of its inability to withstand the variable cyclic loads and compression forces that it is subjected to. While regeneration of the damaged cartilage by an entirely new articular surface is a goal beyond current available techniques, repair of the osteochondral defects with normal hyaline cartilage is possible by various options. Osteochondral defects that are larger then 2 cm are best treated by osteochondral autograft technique. The short-term outcomes of the present series show excellent results.

Zone-specific integrated cartilage repair using a scaffold-free tissue engineered construct derived from allogenic synovial mesenchymal stem cells: Biomechanical and histological assessments

The purpose of the present study was to investigate the zone-specific integration properties of articular cartilage defects treated in vivo with scaffold-free three-dimensional tissue-engineered constructs (TECs) derived from allogenic synovial mesenchymal stem cells (MSCs) in a porcine model. The TEC derived from the synovial MSCs was implanted into chondral defects in the medial femoral condyle of the knee. The integration boundary of repair tissue with the adjacent host cartilage was morphologically and biomechanically evaluated at 6 months post-implantation. Histological assessments showed that the repair tissue in each zone was well integrated with the adjacent host cartilage, with an apparent secure continuity of the extracellular matrix. There were no significant differences in histological scores between the integration boundary and the center of the repair tissue at every zone. Nonetheless, in all the specimens subjected to mechanical testing, failure occurred at the integration boundary. The average tensile strength of the integration boundary vs normal cartilage was 0.6 vs 4.9, 3.0 vs 12.6, and 5.5 vs 12.8MPa at the superficial, middle, and deep layers, respectively. Thus, these results indicate the most fragile point in the repair tissue remained at the integration boundary in spite of the apparent secure tissue continuity and equivalent histological quality with the center of the repair tissue. Such tissue vulnerability at the surface integration boundary could affect the long-term durability of the tissue repair, and thus, special consideration will be needed in the post-operative rehabilitation programming to enhance the longevity of such repair tissues in response to normal knee loading.

Open Versus Arthroscopic Mosaicplasty of the Knee: A Cadaveric Assessment of Accuracy of Graft Placement Using Navigation

PURPOSE

The purpose of this study was to compare an open freehand mosaicplasty technique with an arthroscopic technique for the treatment of osteochondral lesions by measuring the instrument deviation, quantifying this deviation, and providing numerical information on the difference in the outcomes of these techniques.

METHODS

Four cadaveric knees were used. Reference markers were attached to the femur, tibia, and donor/recipient site guides. A total of 10 osteochondral grafts were harvested and inserted into recipient sites arthroscopically and 10 similar grafts were inserted freehand. The angles of graft removal and placement were calculated for each of the surgical groups compared. Ostensibly, a navigation system was used as an aid, to measure the graft placement parameters.

RESULTS

Statistical analysis revealed that there was no statistically significant difference between the arthroscopic method and the freehand method regarding the angle of graft removal at the donor site (P = .162), recipient site plug removal angle (P = .731), and recipient site graft placement angle (P = .630). In the freehand group, the mean angle of graft removal at the donor site was 12°, the mean angle of recipient site plug removal was 10.7°, and the mean angle of recipient site plug placement was 10.6°. Using the arthroscopic technique, the mean angle of graft removal at the donor site was 17.14°, the mean angle of recipient site plug removal was 12.0°, and the mean angle of recipient site graft placement was 10.14°.

CONCLUSIONS

Our study revealed there was no statistically significant difference regarding precision and accuracy during harvesting, recipient site preparation, and plug placement between the 2 techniques.

CLINICAL RELEVANCE

Controversy exists whether an open or arthroscopic osteoarticular transfer system (OATS) technique provides superior accuracy. According to our results, there is no statistically significant difference regarding better visualization, precision, and accuracy between the freehand and arthroscopic techniques. However, larger number of specimens are required for study.

Cartilage lesions of the patella: management after acute patellar dislocation

Articular cartilage injuries to the patella are frequent after patellar dislocation. The management of these acute cartilage injuries in the acute setting can be challenging. It is well documented that acute fixation is the optimal choice for treatment of osteochondral injuries. This article discusses the challenges and potential treatment options for acute chondral/osteochondral injuries to the patella after acute patellar dislocation.

Systematic review of autogenous osteochondral transplant outcomes

PURPOSE

The goal of this systematic review was to present the current best evidence for clinical outcomes of osteochondral autograft transplantation to elucidate the efficacy of this procedure.

METHODS

PubMed, CINAHL, and the Cochrane Central Register of Controlled Trials were searched (key terms "knee," "osteochondral autograft transfer," or "mosaicplasty") to identify relevant literature between 1950 and 2013 in the English language. This evaluation included studies in pediatric and adult patients with grade 3 or 4 articular cartilage injuries; the studies had a minimum of 25 patients and at least 12 months of follow-up and compared osteochondral autograft transfers/mosiacplasty with another treatment modality. Articles were limited to full-text randomized controlled trials or cohort studies. Main outcomes studied were patient-reported and functional outcome, with secondary outcomes including effect of lesion size, return to sport and sport function, radiographic outcomes, and reoperation rates.

RESULTS

There were a total of 9 studies with 607 patients studied in this systematic review. When osteochondral autologous transfer/mosaicplasty (OATM) was compared with microfracture (MF), patients with OATM had better clinical results, with a higher rate of return to sport and maintenance of their sports function from before surgery. Meanwhile, patients who underwent MF trended toward more reoperations, with deterioration around 4 years after surgery. When compared with autologous chondrocyte implantation (ACI), clinical outcome improvement was not conclusive; however, at 10-year follow-up, a greater failure rate was found to be present in the OATM group.

CONCLUSIONS

Current evidence shows improved clinical outcomes with OATM when compared with preoperative conditions. These patients were able to return to sport as early as 6 months after the procedure. It could be suggested from the data that OATM procedures might be more appropriate for lesions that are smaller than 2 cm(2) with the known risk of failure between 2 and 4 years. Further high-quality prospective studies into the management of these articular cartilage injuries are necessary to provide a better framework within which to target intervention.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Use of quantitative MRI for the detection of progressive cartilage degeneration in a mini-pig model of osteoarthritis caused by anterior cruciate ligament transection

BACKGROUND

To investigate the progression of cartilage degeneration using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping in a mini-pig model of osteoarthritis (OA) caused by anterior cruciate ligament transection (ACLT).

METHODS

Twelve mini-pigs underwent ACLT in the left knee and were monitored by dGEMRIC (T1, gadolinium [Gd]) and T2 mapping after 2, 4, or 6 weeks (n = 4 each). No ACLT surgery was performed in four healthy control mini-pigs, which were also monitored by dGEMRIC and T2 mapping. Cartilage samples from the weight-bearing regions of the left medial femoral condyles were collected for macroscopic, histological, immunohistochemical, and biochemical analysis. Correlations between biochemical contents and T1,Gd and T2 values were evaluated using Pearson correlation analysis.

RESULTS

T1,Gd values were gradually reduced and T2 values increased over time. Cartilage surfaces showed roughness at 4 weeks and additional defects at 6 weeks. Glycosaminoglycan (GAG) distribution and content gradually reduced over time (P < 0.05), and collagen distribution and anisotropy were obviously changed at 6 weeks. However, collagen content did not differ significantly among postoperative timepoints. GAG content was positively related to T1,Gd values (r = 0.888; P < 0.001) and negatively related to T2 values (r = -0.865; P < 0.001). Collagen content had no discernible correlation with T1,Gd or T2 values.

CONCLUSION

dGEMRIC and T2 mapping can monitor the progression of cartilage degeneration in a mini-pig model of ACLT-induced OA, permitting early detection of OA.

Autologous resurfacing

BACKGROUND

There is a discrepancy between the interest in joint-reconstructions and the current knowledge about the healing-processes involved. Major reconstructions are performed with osteosynthesized allografts and fresh allografts for cartilage.

OBJECTIVES

The main question to be answered is: what do we know about metaphyseal and epiphyseal cancellous bone healing, contact healing of the subchondral bone and its influence on cartilage healing? Can we achieve healing of all four compartments in contact?

PURPOSE

The purpose is to systematically investigate through animal testing the healing processes of metaphyseal and epiphyseal bone, including the subchondral bone and the healing of cartilage of press-fit-inserted grafts, considering nondemineralized high-resolution histology.

MATERIAL AND METHODS

Primary cancellous-bone healing of osteosynthesized hemi-osteotomies was studied in 13 canine tibial heads, the contact healing was investigated in 7 dogs and 18 giant-rabbits comparing contact-healing of press-fit-inserted autologs cylindrical grafts with empty defects applying the wet-grinding diamond-technology. Bench-experiments on the epiphyseal bones of swine including pullout-tests of cylindrical grafts formed the basis for validation of that press-fit diamond technology.

RESULTS

Primary metaphyseal and epiphyseal contact healing, including hyaline cartilage, was found in all compartments of the meta-and epiphysis in the precisely performed experiments. The press-fit principle, which employs cylindrical grafts and diamond instrumentation featuring a difference of 15/100 mm between graft and recipient bed, achieved high loads between 73.48 and 178.95 N (mean value 118.16 and standard deviation 32.79) in the pullout tests.

CONCLUSION

Autologous press-fit grafting with alignment of the bony baseplate using wet-grinding precision has attained promising histo-morphological results.

Influence of basal support and early loading on bone cartilage healing in press-fitted osteochondral autografts

PURPOSE

The influence of basal graft support combined to early loading following an osteochondral autograft procedure is unclear. It was hypothesized that bottomed grafts may allow for early mobilization by preventing graft subsidence and leading to better healing.

METHODS

Osteochondral autografts were press fitted in the femoral condyles of 24 sheep (one graft per animal). In the unbottomed group (n = 12), a gap of 2 mm was created between graft and recipient bone base. In the bottomed group (n = 12), the graft firmly rested on recipient bone. Animals were allowed immediate postoperative weightbearing. Healing times were 3 and 6 months per group (n = 6 per subgroup). After killing, histological and histomorphometric analyses were performed.

RESULTS

Unbottomed grafts at 3 months showed significantly more graft subsidence (P = 0.024), significantly less mineralized bone (P = 0.028) and significantly worse cartilage and subchondral bone plate healing (P = 0.034) when compared to bottomed grafts. At 6 months, no differences were seen. Compared to the native situation, unbottomed grafts showed significantly more graft subsidence (P = 0.024), whereas bottomed grafts did not. Cystic lesions were seen in both groups. Osteoclasts were closely related to the degree of bone remodelling.

CONCLUSION

In the animal model, in the case of early loading, bottomed osteochondral autografts have less chance of graft subsidence. Evident subsidence negatively influences the histological healing process. In the osteochondral autograft procedure, full graft support should be aimed for. This may allow for early mobilization, diminish graft subsidence and improve long-term integration.

Autologous osteochondral transplantation for treating patellar chondral injuries: evaluation, treatment, and outcomes of a two-year follow-up study

BACKGROUND

The patella is the largest human sesamoid bone and often sustains chondral injury. There is no consensus on how to treat a full-thickness, symptomatic articular cartilage injury of the patella. We analyzed the clinical and functional outcomes of patients with symptomatic full-thickness patellar chondral lesions treated with autologous osteochondral transplantation and evaluated osteochondral autograft bone-plug integration through magnetic resonance imaging.

METHODS

In this prospective study, thirty-three patients with a symptomatic full-thickness patellar chondral injury surgically treated with autologous osteochondral transplantation were evaluated before and after surgical treatment with a minimum two-year follow-up using the Lysholm, Kujala, and Fulkerson questionnaires and the Short Form-36 health survey score. Magnetic resonance images were made at six and twelve months postoperatively and studies were performed to analyze the osteochondral autograft bone-plug integration.

RESULTS

All thirty-three patients showed a significant improvement in functional scores two years after surgery. The average Lysholm scores were 57.27 points preoperatively and 80.76 points at two years postoperatively, the average Kujala scores were 54.76 points preoperatively and 75.18 points at two years postoperatively, and the Fulkerson average scores were 54.24 points preoperatively and 80.42 points at two years postoperatively. The Short Form-36 life quality score improved significantly. Two years after surgery, all magnetic resonance images showed full bone-plug integration into the patella.

CONCLUSIONS

Autologous osteochondral transplantation is a successful technique to surgically treat symptomatic full-thickness patellar articular cartilage injuries smaller than 2.5 cm in diameter. Patients had a significant improvement in clinical scores. Bone-plug integration and surface alignment were demonstrated in all patients two years after surgery.

LEVEL OF EVIDENCE

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

Current concepts of articular cartilage restoration techniques in the knee

Context:

Articular cartilage injuries are common in patients presenting to surgeons with primary complaints of knee pain or mechanical symptoms. Treatment options include comprehensive nonoperative management, palliative surgery, joint preservation operations, and arthroplasty.

Evidence Acquisition:

A MEDLINE search on articular cartilage restoration techniques of the knee was conducted to identify outcome studies published from 1993 to 2013. Special emphasis was given to Level 1 and 2 published studies.

Study Design:

Clinical review.

Level of Evidence:

Level 3.

Results:

Current surgical options with documented outcomes in treating chondral injuries in the knee include the following: microfracture, osteochondral autograft transfer, osteochondral allograft transplant, and autologous chondrocyte transplantation. Generally, results are favorable regarding patient satisfaction and return to sport when proper treatment algorithms and surgical techniques are followed, with 52% to 96% of patients demonstrating good to excellent clinical outcomes and 66% to 91% returning to sport at preinjury levels.

Conclusion:

Clinical, functional, and radiographic outcomes may be improved in the majority of patients with articular cartilage restoration surgery; however, some patients may not fully return to their preinjury activity levels postoperatively. In active and athletic patient populations, biological techniques that restore the articular surface may be options that provide symptom relief and return patients to their prior levels of function.

Cell-laden biphasic scaffolds with anisotropic structure for the regeneration of osteochondral tissue

Sufficient treatment of chondral and osteochondral defects to restore function of the respective tissue remains challenging in regenerative medicine. Biphasic scaffolds that mimic properties of bone and cartilage are appropriate to regenerate both tissues at the same time. The present study describes the development of biphasic, but monolithic scaffolds based on alginate, which are suitable for embedding of living cells in the chondral part. Scaffolds are fabricated under sterile and cell-compatible conditions according to the principle of diffusion-controlled, directed ionotropic gelation, which leads to the formation of channel-like, parallel aligned pores, running through the whole length of the biphasic constructs. The synthesis process leads to an anisotropic structure, as it is found in many natural tissues. The two different layers of the scaffolds are characterized by different microstructure and mechanical properties which provide a suitable environment for cells to form the respective tissue. Human chondrocytes and human mesenchymal stem cells were embedded within the chondral layer of the biphasic scaffolds during hydrogel formation and their chondrogenic (re)differentiation was successfully induced. Whereas viability of non-induced human mesenchymal stem cells decreased during culture, cell viability of human chondrocytes and chondrogenically induced human mesenchymal stem cells remained high within the scaffolds over the whole culture period of 3 weeks, demonstrating successful fabrication of cell-laden centimetre-scaled constructs for potential application in regenerative treatment of osteochondral defects. Copyright © 2014 John Wiley & Sons, Ltd.

Matching articular surfaces of selected donor and recipient sites for cylindrical osteochondral grafts of the femur: quantitative evaluation using a 3-dimensional laser scanner

BACKGROUND

Autogenous osteochondral grafting has been widely performed as a treatment for focal osteochondral defects. In this procedure, it is important to match the shape of the articular surface between the donor site and recipient site to reproduce the original articular surface of the femur.

PURPOSE

To investigate the ideal matching patterns of articular surface profiles of donor and recipient sites for autogenous osteochondral grafting of the femur using a 3-dimensional laser scanning method.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The donor and recipient sites in 11 cadaveric knees were examined, and each of the sites was divided into 12 areas. In the donor sites, the contours of the articular surface of the medial and lateral femoral trochleae were determined. In the recipient sites, the contours of the articular surface of the medial and lateral femoral condyles were assessed. Vertical intervals (VIs) were then calculated as the parameter for the height of the articular surface. The VI was the height difference from the highest and lowest points in the contours of the articular surface within the area of the donor and recipient sites. Finally, assessments were made on whether the articular surface of the donor and recipient sites matched properly for cylindrical osteochondral grafts with diameters of 6, 8, and 10 mm.

RESULTS

For the donor site, the VIs of the middle area of the femoral trochlea were significantly smaller than those of the peripheral area. For the recipient site, the VIs of the anterior area of the femoral condyle were significantly smaller than those of the posterior area.

CONCLUSION

These results indicated in aging specimens that the articular surface profile of the middle area of the donor site matched that of the anterior area of the recipient site. On the other hand, the shape of the articular surface of the peripheral area of the donor site was congruent with that of the posterior area of the recipient site.

CLINICAL RELEVANCE

This study will be useful for improving donor site selection during preoperative planning. The authors recommend selection of the middle area of the femoral trochlea for cartilage defects in the anterior area of the femoral condyle and of the peripheral area of the femoral trochlea for cartilage defects in the posterior area of the femoral condyle.

Articular cartilage repair: procedures versus products

This review discusses the current perspectives and practices regarding the treatment of articular cartilage injury. Specifically, the authors have delineated and examined articular cartilage repair techniques as either surgical procedures or manufactured products. Although both methodologies are used to treat articular cartilage injury, there are obvious advantages and disadvantages to the application of both, with the literature providing few recommendations on the most suitable regimen for the patient and surgeon. In recent times, cell-based tissue engineering products, predominantly autologous chondrocyte implantation, have been the subject of much research and have become clinically popular. Herein, we review the most used procedures and products in cartilage repair, compare and contrast their outcomes, and evaluate the issues that must be overcome in order to improve patient efficacy in the future.

Surgical options for articular defects of the knee

Cartilage and osteochondral defects of the knee can in most cases be treated with total knee replacement in the elderly population. However, these lesions pose a difficult treatment problem in the younger patient. A number of surgical options are available today to address this increasingly common condition and each has its own indications and limitations. This article reviews debridement and microfracture, fixation, metallic spacing devices, autologous chondrocyte implantation, osteochondral autograft transplantation, fresh cadaveric allografts and osteotomies. In addition, possible future developments are discussed.

Results at 10 to 14 years after osteochondral autografting (mosaicplasty) in articular cartilage defects in the knee

PURPOSE

The aim of this study was to evaluate the medium-term (5-9 years) and long-term (10-14 years) outcomes of mosaicplasty in the knee and identify possible risk factors for poor outcome.

METHODS

We included patients 60 years or younger with symptomatic focal full-thickness chondral lesions. Seventy-three patients (87%) with median age of 34 years were available for analyses. Clinical outcome was evaluated by Lysholm score and VAS of pain.

RESULTS

Both the mean Lysholm score and mean VAS pain score improved significantly from baseline, 49 (SD 17) and 58 (SD 23), respectively, to both the mid-term follow-up, 72 (SD18, p<0.001) and 27 (SD 20, p<0.001), respectively, and the long-term follow-up, 72 (SD 21, p<0.001) and 33 (SD 23, p<0.001), respectively. A poor outcome at the long-term follow-up - defined as a Lysholm score of 64 or less or having had a knee replacement - was found in 40%. A poor outcome was more frequent in patients 40 years or older (59%), in women (61%) and in defects with an area of 3 cm(2) or more (57%). Conversely, in a subgroup of male individuals younger than 40 years with defect size less than 3 cm(2) the failure rate was 12.5% and the mean Lysholm score was 82 (SD 16).

CONCLUSION

We conclude that the long-term clinical outcome after mosaicplasty varies greatly depending on age, gender and the size of the lesion.

LEVEL OF EVIDENCE

IV-Retrospective Case Series.