Presence of subchondral bone marrow edema at the time of treatment represents a negative prognostic factor for early outcome after autologous chondrocyte implantation

MR imaging after patellar MACI and MPFL reconstruction: a comparison of isolated versus combined procedures

OBJECTIVE

To qualitatively and quantitatively evaluate the 2.5-year MRI outcome after Matrix-associated autologous chondrocyte implantation (MACI) at the patella, reconstruction of the medial patellofemoral ligament (MPFL), and combined procedures.

METHODS

In 66 consecutive patients (age 22.8 ± 6.4years) with MACI at the patella (n = 16), MPFL reconstruction (MPFL; n = 31), or combined procedures (n = 19) 3T MRI was performed 2.5 years after surgery. For morphological MRI evaluation WORMS and MOCART scores were obtained. In addition quantitative cartilage T2 and T1rho relaxation times were acquired. Several clinical scores were obtained. Statistical analyses included descriptive statistics, Mann-Whitney-U-tests and Pearson correlations.

RESULTS

WORMS scores at follow-up (FU) were significantly worse after combined procedures (8.7 ± 4.9) than after isolated MACI (4.3 ± 3.6, P = 0.005) and after isolated MPFL reconstruction (5.3 ± 5.7, P = 0.004). Bone marrow edema at the patella in the combined group was the only (non-significantly) worsening WORMS parameter from pre- to postoperatively. MOCART scores were significantly worse in the combined group than in the isolated MACI group (57 ± 3 vs 88 ± 9, P < 0.001). Perfect defect filling was achieved in 26% and 69% of cases in the combined and MACI group, respectively (P = 0.031). Global and patellar T2 values were higher in the combined group (Global T2: 34.0 ± 2.8ms) and MACI group (35.5 ± 3.1ms) as compared to the MPFL group (31.1 ± 3.2ms, P < 0.05). T2 values correlated significantly with clinical scores (P < 0.005). Clinical Cincinnati scores were significantly worse in the combined group (P < 0.05).

CONCLUSION

After combined surgery with patellar MACI and MPFL reconstruction inferior MRI outcomes were observed than after isolated procedures. Therefore, patients with need for combined surgery may be at particular risk for osteoarthritis.

The AMADEUS score is not a sufficient predictor for functional outcome after autologous chondrocyte implantation (ACI) of the knee: data from the German Cartilage Registry (KnorpelRegister DGOU)

INTRODUCTION

The AMADEUS (Area Measurement And DEpth and Underlying Structures) score has advanced to a commonly used tool for MRI-based chondral defect severity grading prior to cartilage knee surgery. It was the intention of this study to assess the AMADEUS for a potential correlation with clinical data by patient-reported outcome measures (PROMs).

METHODS

A total of 51 patients undergoing ACI (autologous chondrocyte implantation) between 2016 and 2022 were found eligible and retrospectively analyzed. All patients were registered in the German Cartilage Registry prior to surgery and follow-up data were collected using the Knee Osteoarthritis Outcome score (KOOS), the International Knee Documentation Committee (IKDC) Form and the numeric rating scale (NRS). Pre-operative MRI images were scored by three raters using the AMADEUS classification system, and an overall AMADEUS score was calculated which was subsequently correlated with pre- and post-operative PROMs.

RESULTS

Mean patient age was 32.67 ± 8.37 years and mean defect size area 343.04 mm2 ± 139.45 mm2. No correlative capacity of the pre- and postoperative IKDC, KOOS or NRS scores was found with the AMADEUS final score or any of its subscores. From the pre- to postoperative visit, a significant improvement of the PROMs (IKDC: 45.53 ± 21.00 vs. 59.83 ± 17.93, p = 0.04; KOOS Pain: 58.00 ± 16.70 vs. 76.06 ± 19.20, p = 0.03; KOOS ADL: 64.17 ± 18.76 vs. 82.11 ± 16.68, p < 0.01; KOOS Sports: 26.11 ± 18.52 vs. 50.56 ± 23.94, p = 0.01; KOOS QOL: 25.50 ± 14.26 ± 45.28 ± 19.03, p = 0.00) was found. Intraclass correlation coefficients showed an overall good interrater agreement for the AMADEUS total score (ICC = 0.75).

CONCLUSIONS

Study results suggest no correlative capacity of the AMADEUS with routinely used PROMs in patients undergoing ACI. Therefore, radiographically assessed cartilage defect characteristics poorly translate to pre- and postoperative patient-reported outcome data.

Preoperative Bone Marrow Edema Negatively Impacts 10-Year Outcomes After Unicompartmental Knee Arthroplasty

BACKGROUND

The purpose of this study was to investigate the association between the extent of subchondral bone marrow edema (BME), as classified by magnetic resonance imaging, and intermediate to long-term outcomes after unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis.

METHODS

We enrolled 150 knees (144 patients) that underwent fixed-bearing UKA between April 2003 and December 2014 with a minimum follow-up of 5 years; the mean overall follow-up duration was 10 years (range, 5-18 years). We divided the patients into 2 groups based on the presence or absence of preoperative BME. Patients were also subdivided into 4 groups according to their BME scores determined by the magnetic resonance imaging Osteoarthritis Knee Score method. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Forgotten Joint Score. Furthermore, survival rates and relevant risk factors that affect joint survivorship were analyzed.

RESULTS

The groups with BME demonstrated significantly worse postoperative WOMAC pain and Forgotten Joint Scores at the final follow-up than the group without BME (all P < .05). We also found significant differences among the scores of groups with different BME grades (all P < .05). Post hoc analysis demonstrated differences between groups 1 and 2, 1 and 3, 1 and 4, and 2 and 4 (all P < .05) with a significant correlation between postoperative clinical outcomes and the extent of BME (r = 0.430 [WOMAC pain], r = -0.342 [Forgotten Joint Score]; P < .05). The survival rate was 95.4% for a mean period of 10 years for the UKAs, and the UKA survival was not associated with the presence of BME (P = .232; log-rank test).

CONCLUSION

At a mean of 10 years, preoperative BME negatively impacted the clinical outcomes, especially pain, after UKA. However, UKA contributed to excellent survival rates for the same duration of follow-up, regardless of BME severity. Although this study does not provide any evidence that preoperative BME should be identified as a contraindication, evaluation of BME can provide crucial information about the expected outcomes.

The AMADEUS score is not a sufficient predictor for functional outcome after high tibial osteotomy

PURPOSE

The Area Measurement And Depth Underlying Structures (AMADEUS) classification system has been proposed as a valuable tool for magnetic resonance (MR)-based grading of preoperatively encountered chondral defects of the knee joint. However, the potential relationship of this novel score with clinical data was yet to determine. It was the primary intention of this study to assess the correlative relationship of the AMADEUS with patient reported outcome scores in patients undergoing medial open-wedge high tibial valgus osteotomy (HTO). Furthermore, the arthroscopic ICRS (International Cartilage Repair Society) grade evaluation was tested for correlation with the AMADEUS classification system.

METHODS

This retrospective, monocentric study found a total of 70 individuals that were indicated for HTO due to degenerative chondral defects of the medial compartment between 2008 and 2019. A preoperative MR image as well as a pre-osteotomy diagnostic arthroscopy for ICRS grade evaluation was mandatory for all patients. The Knee Osteoarthritis Outcome Score (KOOS) including its five subscale scores (KOOS-ADL, KOOS-QOL, KOOS-Sports, KOOS-Pain, KOOS-Symptoms) was obtained preoperatively and at a mean follow-up of 41.2 ± 26.3 months. Preoperative chondral defects were evaluated using the AMADEUS classification system and the final AMADEUS scores were correlated with the pre- and postoperative KOOS subscale sores. Furthermore, arthroscopic ICRS defect severity was correlated with the AMADEUS classification system.

RESULTS

There was a statistically significant correlation between the AMADEUS BME (bone marrow edema) subscore and the KOOS Symptoms subscore at the preoperative visit (r = 0.25, p = 0.04). No statistically significant monotonic association between the AMADEUS total score and the AMADEUS grade with pre- and postoperative KOOS subscale scores were found. Intraoperatively obtained ICRS grade did reveal a moderate correlative relation with the AMADEUS total score and the AMADEUS grade (r = 0.28, p = 0.02).

CONCLUSIONS

The novel AMADEUS classification system largely lacks correlative capacity with patient reported outcome measures in patients undergoing HTO. The MR tomographic appearance of bone marrow edema is the only parameter predictive of the clinical outcome at the preoperative visit.

Bone Marrow Lesions on Preoperative Magnetic Resonance Imaging Correlate With Outcomes Following Isolated Osteochondral Allograft Transplantation

PURPOSE

The purpose of this study was to investigate the role of preoperative bone marrow lesion (BML) size and location on (1) postoperative patient reported outcomes and (2) postoperative failure and time to failure after osteochondral allograft (OCA) transplantation.

METHODS

Consecutive patients from 2 senior surgeons who underwent isolated OCA transplantation to the knee from 2009-2018 were identified for the case series. Preoperative magnetic resonance imaging (MRI) was evaluated for BMLs based on 2 classification systems (Welsch et al. and Costa-Paz et al.) by 2 independent graders. BMLs associated with minimum 1-year postoperative outcomes were evaluated, and the effect of BML classification on survivorship was investigated with Kaplan-Meier curves.

RESULTS

The 77 patients who underwent isolated OCA transplantation (mean follow-up: 39.46 ± 22.67 months) and had preoperative MRIs were included. Within this cohort, 82% of patients demonstrated a BML. The preoperative Costa-Paz et al. classification was significantly positively correlated with the postoperative Visual Analog Scale, International Knee Documentation Committee and Veterans RAND 12-Item Health Survey raw scores for both graders (P < 0.05). Failure occurred in 5 of 65 (8%) patients at a mean of 22.86 ± 12.04 months postoperatively. The presence of BML alone did not significantly affect survival (P = 0.780). However, for 1 grader, the Welsch et al. classification was associated with increased risk of graft failure (P = 0.031).

CONCLUSION

Preoperative subchondral BMLs were present in 82% of patients undergoing OCA transplantation. We found that more severe BMLs based on the Costa-Paz classification, with increasing involvement in the juxta-articular surface, were correlated with higher postoperative patient-reported functional outcomes after OCA. BMLs may be associated with an increase in graft failure, but their role in this remains unclear.

LEVEL OF EVIDENCE

IV, Retrospective Case Series.

Quantitative 3-T Magnetic Resonance Imaging After Matrix-Associated Autologous Chondrocyte Implantation With Autologous Bone Grafting of the Knee: The Importance of Subchondral Bone Parameters

BACKGROUND

Matrix-associated autologous chondrocyte implantation (MACI) with autologous bone grafting (ABG) is an effective surgical treatment for osteochondral defects. Quantitative magnetic resonance imaging (MRI) techniques are increasingly applied as noninvasive biomarkers to assess the biochemical composition of cartilage repair tissue.

PURPOSE

To evaluate the association of quantitative MRI parameters of cartilage repair tissue and subchondral bone marrow with magnetic resonance morphologic and clinical outcomes after MACI with ABG of the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Qualitative and quantitative 3 T MRI of the knee was performed in 21 patients (16 male) at 2.5 years after MACI with ABG at the medial (18/21) or lateral (3/21) femoral condyle for the treatment of osteochondral defects. Morphologic MRI sequences were assessed using MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 scores. T2 relaxation time measurements for the assessment of cartilage repair tissue (CRT2) were obtained. Single-voxel magnetic resonance spectroscopy was performed in underlying subchondral bone marrow (BM) and at both central femoral condyles. The presence of pain and Tegner scores were noted. Statistical analyses included Student t tests, correlation analyses, and multivariate regression models.

RESULTS

The mean defect size was 4.9 ± 1.9 cm². At a follow-up of 2.5 ± 0.3 years, 9 of 21 patients were asymptomatic. Perfect defect filling was achieved in 66.7% (14/21) of patients. MOCART 2.0 scores (74.1 ± 18.4) did not indicate pain (68.3 ± 19.0 [pain] vs 81.7 ± 15.4 [no pain]; P = .102). However, knee pain was present in 85.7% (6/7) of patients with deep bony defects (odds ratio, 8.0; P = .078). Relative CRT2 was higher in hypertrophic cartilage repair tissue than in repair tissue with normal filling (1.54 ± 0.42 vs 1.13 ± 0.21, respectively; P = .022). The underlying BM edema-like lesion (BMEL) volume was larger in patients with underfilling compared with patients with perfect defect filling (1.87 ± 1.32 vs 0.31 ± 0.51 cm³, respectively; P = .002). Patients with severe pain showed a higher BMEL volume (1.2 ± 1.3 vs 0.2 ± 0.4 cm³, respectively; P = .046) and had a higher BM water fraction (26.0% ± 12.3% vs 8.6% ± 8.1%, respectively; P = .026) than did patients without pain.

CONCLUSION

Qualitative and quantitative MRI parameters including the presence of subchondral defects, CRT2, BMEL volume, and BM water fraction were correlated with cartilage repair tissue quality and clinical symptoms. Therefore, the integrity of subchondral bone was associated with outcomes after osteochondral transplantation.

Osteo-core Plasty: A Minimally Invasive Approach for Subchondral Bone Marrow Lesions of the Knee

"Bone marrow lesion" (BML) is a common term used to describe the presence of fluid in the bone marrow. Although various pathologies can cause BMLs seen on magnetic resonance imaging, in this Technical Note we focus on treating the lesions associated with osteoarthritis in the knee joint. The role of the subchondral bone in transferring loads within the knee joint, as well as in cartilage homeostasis, is well established. In addition, cartilage and subchondral bone are increasingly considered as an osteochondral unit, rather than as 2 separate structures. Knee osteoarthritis, along with insufficiency fracture, is one of the main indications for the treatment of painful BMLs. Nowadays, there is a growing interest in this field, and new approaches are being developed. Our technique can be defined as a surgical procedure aimed directly at pathology within the subchondral bone and is named "osteo-core plasty." It consists of 2 parts: The first is decompression of bone marrow to decrease intraosseous pressure, and the second is administration of bone marrow aspirate concentrate for better healing potential and bone autograft to deliver supportive tissue. It should be noted that the cause of BMLs must be known before this kind of treatment is performed.

Postoperative Subchondral Bone Marrow Lesion Is Associated With Graft Extrusion After Lateral Meniscal Allograft Transplantation

BACKGROUND

Adverse effects of graft extrusion after meniscal allograft transplantation (MAT) are difficult to assess and can be determined only in the long term using a simple radiograph. Recently, subchondral bone marrow lesions (BMLs) detected on magnetic resonance imaging (MRI) scans have been used to evaluate the outcomes or prognoses of various knee surgeries. However, whether subchondral BMLs on MRI scans reflect the effects of allograft extrusion remains unclear.

HYPOTHESIS

Subchondral BML in the lateral compartment of the knee joint on postoperative MRI scans would be associated with graft extrusion after lateral MAT.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Overall, 170 patients with lateral MAT between 2008 and 2013 were classified into extrusion (≥3 mm) and nonextrusion (<3 mm) groups based on findings on MRI scans obtained 3 to 6 months postoperatively. Subchondral BMLs in the lateral compartment were evaluated on the latest MRI scans. To exclude any bone marrow signal changes other than those caused by allograft extrusion, the latest MRI scans were compared with those obtained 3 to 6 months postoperatively. Only subchondral BMLs that occurred after that time point were counted. The association between allograft extrusion and subchondral BML was assessed using chi-square analysis. Logistic regression analysis was performed to control other related factors, including age, sex, body mass index, time from previous meniscectomy, alignment, and cartilage status at the time of MAT. Clinical outcomes according to subchondral BML were evaluated using the Lysholm score.

RESULTS

Of the 170 patients, 20 (11.8%) had subchondral BML on the latest MRI scans at a mean 53.6 ± 31.2 months postoperatively, with 14 and 6 patients in the extrusion and nonextrusion groups, respectively. Chi-square analysis showed a significant association between allograft extrusion and subchondral BMLs (P = .025). Logistic regression analysis showed that extrusion and age were significant factors associated with subchondral BML (P = .011 and .004, respectively). However, no differences were observed in the Lysholm scores in accordance with the subchondral BML (P = .248).

CONCLUSION

Subchondral BMLs on postoperative MRI scans were associated with graft extrusion after lateral MAT. However, there was no difference in clinical outcomes according to subchondral BML.

Degree of Preoperative Subchondral Bone Marrow Lesion Is Associated With Postoperative Outcome After Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

In osteoarthritis of the knee, subchondral bone marrow lesion (BML) is known to be significantly associated with the severity of pain. However, little is known about the influence of preoperative BML on postoperative outcomes after medial opening wedge high tibial osteotomy (MOWHTO).

PURPOSE

To compare patient-reported outcomes for those who underwent MOWHTO according to the severity of BML based on magnetic resonance imaging.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 136 patients who underwent MOWHTO between June 2011 and May 2016 with clinical and radiologic assessments before and after surgery were retrospectively enrolled. Patients were divided into 2 groups according to the presence or absence of BMLs. They were then subdivided into 4 or 3 groups based on the sum of BML scores of the medial femoral condyle and tibial plateau according to MRI (magnetic resonance imaging) Osteoarthritis Knee Score or Filardo classification, respectively. Associations between the severity of BML and postoperative 1- and 2-year Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscores were evaluated through linear regression analysis. At postoperative 2 years, the rate of patients having a WOMAC score improvement of 15 points based on minimum clinically important difference and patient satisfaction were compared between groups.

RESULTS

BMLs were present in 96 (70.6%) of 136 cases. There were no significant differences in demographics or radiographic variables between groups according to the presence/absence or severity of BMLs (all P > .05). There was a significant association between preoperative or 1-year postoperative WOMAC pain/function score and the extent or intensity of BMLs (all P < .05). After adjusting for age, body mass index, osteoarthritis grade, and hip-knee-ankle angle, the significance persisted in the association between the extent or intensity of BMLs and WOMAC pain/function score at 1 year after surgery (all P < .05). However, a significant association was not found at postoperative 2 years (all P > .05). All groups showed similar rates of WOMAC score showing 15 points of improvement and satisfaction after MOWHTO (all P > .05). At 2 years after surgery, 82.5% of patients with BMLs were satisfied with their operation, as compared with 84.4% of those without BMLs (P = .801).

CONCLUSION

Although worse clinical outcomes were associated with severe BML during the recovery period, MOWHTO provided a high degree of clinical improvement on patient-reported outcomes regardless of the severity of BML at 2 years postoperatively.

Severe Bone Marrow Edema Among Patients Who Underwent Prior Marrow Stimulation Technique Is a Significant Predictor of Graft Failure After Autologous Chondrocyte Implantation

BACKGROUND

Autologous chondrocyte implantation (ACI) is a well-established cartilage repair procedure; however, numerous studies have shown higher ACI graft failure rates after prior marrow stimulation techniques (MSTs).

PURPOSE

To identify which factors may predict decreased graft survival after ACI among patients who underwent a prior MST. A secondary aim was to investigate the specificity of these predictors.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

In this review of prospectively collected data, the authors analyzed 38 patients who had failed prior MST surgery and subsequently underwent collagen-covered ACI (case group). The case group was divided into graft failure ACI (n = 8, 21%) and successful ACI (n = 30, 79%). Fourteen clinical variables were categorized and analyzed to determine predictors for failure of the ACI graft: age, body mass index, sex, defect characteristics (number, size, location, etiology, type), presence of kissing lesion, intraoperative presence of intralesional osteophyte, time between an MST and ACI, previous surgery, duration of the symptoms, and concomitant surgical procedure. Preoperative magnetic resonance imaging (MRI) was used to evaluate the severity of subchondral bone marrow edema (BME), graded I (absent) to IV (severe), and the presence of subchondral cyst, hypertrophic sclerosis, and intralesional osteophyte. The effects of these MRI findings on the graft survivor were also investigated. Concurrently, a control group without a prior MST was matched to investigate the specificity of the previously determined predictors. These patients were matched individually according to age, sex, body mass index, and outcome of the procedure (failure [n = 8] or successful [n = 30] per the case group).

RESULTS

In the case group, the presence of preoperative severe BME was significantly higher among patients with failed ACI as compared with patients with successful ACI (P < .001). In the control group, the presence of severe BME was not significantly different between the failure and successful groups (P = .747). The ACI graft failure rate among patients with a prior MST and preoperative grade IV BME was 83.7% at 5 years postoperatively, resulting in a significantly lower survival rate as compared with patients with a prior MST and without severe BME (5-year graft failure rate, 6.5%; P < .001). All the other parameters did not differ significantly.

CONCLUSION

After a prior MST, the presence of grade IV BME by MRI was a predictive factor for graft failure among patients who then underwent second-generation ACI.

Articular Cartilage Lesion Characteristic Reporting Is Highly Variable in Clinical Outcomes Studies of the Knee

OBJECTIVE

The purpose of this study was to investigate the degree of standardized evaluation and reporting of cartilage lesion characteristics in high-impact clinical studies for symptomatic lesions of the knee. We hypothesized that there are significant inconsistencies in reporting these metrics across orthopedic literature.

DESIGN

A total of 113 clinical studies on articular cartilage restoration of the knee were identified from 6 high-impact orthopedic journals between 2011 and 2016. Full-text review was used to evaluate sources for details on study methodology and reporting on the following variables: primary procedure, location, size, grade, and morphology of cartilage lesions.

RESULTS

All studies reported on the type of primary cartilage procedure and precise lesion location(s). Approximately 99.1% reported lesion morphology (chondral, osteochondral, mixed). For lesion size, 32.7% of articles did not report how size was measured and 11.5% did not report units. The lesion sizing method was variable, as 27.4% used preoperative magnetic resonance imaging to measure/report lesion size, 31.0% used arthroscopy, and 8.8% used both. The majority of studies (83.2%) used area to report size, and 5.3% used diameter. Formal grading was not reported in 17.7% of studies. Only 54.8% of studies reported depth when sizing osteochondral defects.

CONCLUSIONS

Recent literature on cartilage restoration provides adequate information on surgical technique, lesion location, and morphology. However, there is wide variation and incomplete reporting on lesion size, depth, and grading. Future clinical studies should include these important data in a consistent manner to facilitate comparison among surgical techniques.

Long-Term Clinical and MRI Results of Matrix-Assisted Autologous Chondrocyte Implantation for Articular Cartilage Defects of the Knee

OBJECTIVE

To evaluate the long-term clinical and radiological outcome of matrix-assisted autologous chondrocyte implantation (mACI) for articular cartilage defects in the knee joint.

DESIGN

Clinical evaluation was assessed in 21 patients with full-thickness cartilage defects, International Cartilage Repair Society (ICRS) grade IV. Clinical scoring was performed preoperatively and 12 years after transplantation using the International Knee Documentation Committee (IKDC) score, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Noyes sports activity rating scale. Morphologic evaluation of the repair tissue was assessed by magnetic resonance imaging (MRI) in 14 patients using the Kreuz-Henderson score.

RESULTS

Clinical evaluation revealed significant improvement in the IKDC, the Lysholm, the KOOS, and the Noyes score. Morphological evaluation by MRI showed moderate to complete defect filling in 10 of 14 patients, demonstrating normal to nearly normal values in mean 74.29% of all assessed parameters. Significant correlation of the parameter cartilage signal and clinical outcome was found with the IKDC, Lysholm, and KOOS subscales ADL (activities of daily living) and QoL (quality of life).

CONCLUSIONS

The clinical and radiological outcomes 12 years after transplantation suggest the confirmation of the promising results of the mid-term follow-up. This study therefore provides first indications that the implantation of mACI might be a suitable option for long-term cartilage repair. Future controlled studies need to address the exact parameters influencing the long-term outcome of mACI.

Autologous Chondrocyte Implantation "Segmental-Sandwich" Technique for Deep Osteochondral Defects in the Knee: Clinical Outcomes and Correlation With Magnetic Resonance Imaging Findings

Background

Symptomatic osteochondral defects are difficult to manage, especially in patients with deep (>8-10 mm) empty defects. The restoration of articular congruence is crucial to avoid the progression to osteoarthritis (OA).

Purpose

To describe the autologous chondrocyte implantation (ACI) "segmental-sandwich" technique for restoration of the osteochondral unit and to evaluate midterm outcomes in patients treated with this procedure. Correlations between magnetic resonance imaging (MRI) and radiographic findings with outcomes were assessed.

Study Design

Case series; Level of evidence, 4.

Methods

Outcomes were evaluated for a consecutive cohort of 15 patients with symptomatic deep (>8 mm) osteochondral lesions who underwent autologous bone grafting plus the ACI segmental-sandwich technique performed by a single surgeon between 2003 and 2011. Patients with a minimum 2-year follow-up were included. All patients completed validated clinical outcome scales and a patient satisfaction survey. The Kellgren-Lawrence (K-L) grade was assessed for the progression to OA. The repair site was evaluated with the MOCART (magnetic resonance observation of cartilage repair tissue) score. Filling and tissue characteristics of the bone defect were analyzed with MRI.

Results

All patients (mean age at surgery, 31.0 ± 9.1 years) were available for follow-up (mean follow-up, 7.8 ± 3.0 years; range, 2-15 years). The mean chondral lesion size was 6.0 ± 3.5 cm² (range, 1.5-13.5 cm²), with a mean bone defect area of 1.7 cm² (27%-40% of overall surface area treated by ACI) and depth of 1.0 cm. All patients had successful clinical outcomes, and all functional scores improved significantly (P < .05). Patients reported a very high satisfaction rate (93%). The K-L grade demonstrated no significant progression to OA over a mean follow-up of 4.7 years. For 12 patients with MRI results available, the mean MOCART score at a mean of 3.3 years was 64.2 ± 19.9, with complete or near-complete (≥75% of defect volume) chondral defect filling (83%) and complete integration to adjacent cartilage (83%). Bone defects were completely filled in 83% of patients.

Conclusion

The ACI segmental-sandwich technique provides significant functional improvements at midterm follow-up and excellent survival rates. This unique treatment allows for the resurfacing of cartilage defects and the repair of underlying segmental bone lesions.

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

Background:

Articular cartilage defects of the knee can significantly impair function among young, high-demand patients. There are several techniques for chondral restoration, including osteochondral allograft transplantation (OCA), that may alleviate pain and re-create the native anatomy. However, clinical outcomes among athletic cohorts are limited.

Purpose:

To evaluate the efficacy and functional outcomes of OCA for medium to large osteochondral defects of the knee in physically active United States military servicemembers.

Study Design:

Case series; Level of evidence, 4.

Methods:

A military health care database was queried to identify all OCA procedures performed between January 2009 and March 2013. Inclusion criteria were army personnel with a minimum of 2 years’ follow-up. Exclusion criteria included incomplete follow-up, inaccurate coding, and nonmilitary status. Variables of interest included sex, age, lesion location, grade and size of the lesion, body mass index, tobacco use, preoperative and postoperative visual analog scale (VAS) scores for pain, and presence of perioperative complications. Overall failure was defined as the inability to return to preoperative functional activities because of persistent knee complaints (clinical failure) or a revision cartilage procedure or arthroplasty (surgical failure).

Results:

A total of 61 patients (52 male; mean age, 31.7 years) were identified, with a mean 46.2-month follow-up. The mean VAS pain score improved from 4.10 ± 2.17 preoperatively to 2.68 ± 2.73 postoperatively (P < .0009), and only 6 (9.8%) required a subsequent revision chondral procedure. Overall, 39 patients (63.9%) were able to return to a level of activity that allowed for the completion of military duties. Risk factors for clinical failure were preoperative body mass index, preoperative pain as measured on the VAS, and moderate to severe postoperative pain on the VAS. The risk factor for surgical failure was the presence of a complication. Risk factors for overall failure were the presence of a complication and moderate to severe postoperative pain on the VAS.

Conclusion:

OCA provided moderate success in retaining active-duty army servicemembers. Approximately two-thirds of patients undergoing OCA were able to return to their preinjury occupational activity, while approximately 57% of patients returned to prior levels without a subsequent revision chondral procedure or arthroplasty.

Subchondral Bone and the Osteochondral Unit: Basic Science and Clinical Implications in Sports Medicine

Context:

Articular cartilage injuries and early osteoarthritis are among the most common conditions seen by sports medicine physicians. Nonetheless, treatment options for articular degeneration are limited once the osteoarthritic cascade has started. Intense research is focused on the use of biologics, cartilage regeneration, and transplantation to help maintain and improve cartilage health. An underappreciated component of joint health is the subchondral bone.

Evidence Acquisition:

A comprehensive, nonsystematic review of the published literature was completed via a PubMed/MEDLINE search of the keywords “subchondral” AND “bone” from database inception through December 1, 2016.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Methods:

Articles collected via the database search were assessed for the association of bone marrow lesions and osteoarthritis, cartilage regeneration, and ligamentous and meniscal injury; the clinical disorder known as painful bone marrow edema syndrome; and the subchondral bone as a target for medical and surgical intervention.

Results:

A complex interplay exists between the articular cartilage of the knee and its underlying subchondral bone. The role of subchondral bone in the knee is intimately related to the outcomes from cartilage restoration procedures, ligamentous injury, meniscal pathology, and osteoarthritis. However, subchondral bone is often neglected when it should be viewed as a critical element of the osteochondral unit and a key player in joint health.

Conclusion:

Continued explorations into the intricacies of subchondral bone marrow abnormalities and implications for the advent of procedures such as subchondroplasty will inform further research efforts on how interventions aimed at the subchondral bone may provide durable options for knee joint preservation.

Preoperative Tibial Subchondral Bone Marrow Lesion Patterns and Associations With Outcomes After Isolated Meniscus Allograft Transplantation

BACKGROUND

The association between preoperative tibial subchondral bone marrow lesion (BML) patterns and outcomes after isolated meniscus allograft transplantation (MAT) are unknown.

PURPOSE

To determine (1) if a superior classification means exists (ie, high interrater reliability [IRR]) for grading tibial subchondral BML before isolated MAT and (2) whether quality and/or severity of preoperative tibial subchondral BML patterns was associated with clinical outcomes and/or failure rates after isolated MAT.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All patients who underwent isolated MAT with a single surgeon between October 2006 and February 2017 were identified. Three means were evaluated to quantify the degree of subchondral BML in the affected tibial-sided compartment: Welsch et al, based on maximum diameter of the lesion; Costa-Paz et al, based on appearance and location of the lesion; and Filardo et al, based on severity of findings. IRR was generated and compared among the 3 classifications. The preoperative magnetic resonance imaging (MRI) subchondral BML grading scheme with the highest IRR was then used to assess for associations with postoperative outcomes for those patients with >2-year follow-up, per a Spearman correlation matrix with each reviewer's grades.

RESULTS

In total, 60 MRI scans were available for subchondral BML grading. Grader 1 identified the presence of subchondral BML in the tibia of the affected compartment in 40 (66.7%) of the available MRI scans, as compared with 38 (63.3%) for grader 2. The calculated IRRs with the Welsch et al and Costa-Paz et al classifications were rated "strong/almost perfect" agreement. A significant correlation was demonstrated between grader 1 with the Welsch et al grading scheme and outcome measures of KOOS pain (Knee injury and Osteoarthritis Outcome Score; negative correlation, P = .05), WOMAC pain (Western Ontario and McMaster Universities Osteoarthritis Index; positive correlation, P = .026), and Marx Activity Rating Scale (negative correlation, P = .019). A significant correlation was demonstrated between grader 2 with the Costa-Paz et al grading scheme and postoperative satisfaction (positive correlation, P = .018). There were no significant differences in survivorship based on gradings.

CONCLUSION

Nearly two-thirds of patients who undergo isolated MAT have subchondral BML on preoperative MRI. Our findings suggest that increasing BML size (Welsch et al) is correlated with worse postoperative pain measures (KOOS pain, WOMAC pain) and worse activity ratings (Marx Activity Rating Scale). Additionally, increasing disruption or depression of the normal contour of the cortical surface, with or without lesion contiguity with the subjacent articular surface (Costa-Paz et al), is correlated with greater postoperative satisfaction.

Treatment of a Focal Articular Cartilage Defect of the Talus with Polymer-Based Autologous Chondrocyte Implantation: A 12-Year Follow-Up Period

Autologous chondrocyte implantation (ACI) is a first-line treatment option for large articular cartilage defects. Although well-established for cartilage defects in the knee, studies of the long-term outcomes of matrix-assisted ACI to treat cartilage defects in the ankle are rare. In the present report, we describe for the first time the long-term clinical and radiologic results 12 years after polymer-based matrix-assisted ACI treat a full-thickness talar cartilage defect in a 25-year-old male patient. The clinical outcome was assessed using the visual analog scale and Freiburg ankle score, magnetic resonance imaging evaluation using the Henderson-Kreuz scoring system and T2 mapping. Clinical assessment revealed improved visual analog scale and Freiburg ankle scores. The radiologic analysis and T2 relaxation time values indicated the formation of hyaline-like repair tissue. Polymer-based autologous chondrocytes has been shown to be a safe and clinically effective long-term treatment of articular cartilage defects in the talus.

Advancing osteochondral tissue engineering: bone morphogenetic protein, transforming growth factor, and fibroblast growth factor signaling drive ordered differentiation of periosteal cells resulting in stable cartilage and bone formation in vivo

Background

Chondrogenic mesenchymal stem cells (MSCs) have not yet been used to address the clinical demands of large osteochondral joint surface defects. In this study, self-assembling tissue intermediates (TIs) derived from human periosteum-derived stem/progenitor cells (hPDCs) were generated and validated for stable cartilage formation in vivo using two different animal models.

Methods

hPDCs were aggregated and cultured in the presence of a novel growth factor (GF) cocktail comprising of transforming growth factor (TGF)-β1, bone morphogenetic protein (BMP)2, growth differentiation factor (GDF)5, BMP6, and fibroblast growth factor (FGF)2. Quantitative polymerase chain reaction (PCR) and immunohistochemistry were used to study in vitro differentiation. Aggregates were then implanted ectopically in nude mice and orthotopically in critical-size osteochondral defects in nude rats and evaluated by microcomputed tomography (µCT) and immunohistochemistry.

Results

Gene expression analysis after 28 days of in vitro culture revealed the expression of early and late chondrogenic markers and a significant upregulation of NOGGIN as compared to human articular chondrocytes (hACs). Histological examination revealed a bilayered structure comprising of chondrocytes at different stages of maturity. Ectopically, TIs generated both bone and mineralized cartilage at 8 weeks after implantation. Osteochondral defects treated with TIs displayed glycosaminoglycan (GAG) production, type-II collagen, and lubricin expression. Immunostaining for human nuclei protein suggested that hPDCs contributed to both subchondral bone and articular cartilage repair.

Conclusion

Our data indicate that in vitro derived osteochondral-like tissues can be generated from hPDCs, which are capable of producing bone and cartilage ectopically and behave orthotopically as osteochondral units.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0787-3) contains supplementary material, which is available to authorized users.

Patients Scheduled for Chondrocyte Implantation Treatment with MACI Have Larger Defects than Those Enrolled in Clinical Trials

OBJECTIVE

To compare characteristics for patients scheduled for autologous chondrocyte implantation with matrix-assisted chondrocyte implantation (MACI) with those enrolled in clinical trials and to describe differences in patient selection between countries.

DESIGN

Anonymized data from patients scheduled for MACI treatment in the knee in Europe and Australia/Asia were obtained from the Genzyme/Sanofi database. Average age, defect size, and male-female ratio were analyzed and compared by country. Clinical cohort studies and prospective comparative trials using autologous chondrocyte implantation and related treatments were identified and weighted average age, weighted defect size, and male-female ratio were analyzed and compared with data from the database.

RESULTS

From the database 2,690 patients were included with mean age 33.7 years and male-female ratio of 67:33. Mean defect size was 5.64 cm(2) and 70% of the defects were 3 to 10 cm(2). There were significant differences between patients' mean defect sizes between countries. Sixty-nine studies (57 cohorts and 12 prospective comparative trials) with a total of 5,449 patients were identified. The combined weighted mean age was 34.2 years, and the combined weighted mean defect size was 4.89 cm(2). Patients scheduled for MACI had significantly larger defects that those included in clinical trials. There was no significant difference in age. No differences were found between cohorts and prospective comparative trials.

CONCLUSION

The vast majority of patients scheduled for autologous chondrocyte implantation with MACI have chondral defect comparable to that generally recommended, but differences exist between countries. Patients enrolled in clinical trials have significantly smaller defects than those undergoing treatment outside controlled trials.

Bone Marrow Edema in the Knee and Its Influence on Clinical Outcome After Matrix-Based Autologous Chondrocyte Implantation: Results After 3-Year Follow-up

BACKGROUND

Third-generation autologous chondrocyte implantation (ACI) is an established method for treatment of full-thickness cartilage defects in the knee joint. Subchondral bone marrow edema (BME) is frequently observed after ACI, with unknown pathogenesis and clinical relevance.

PURPOSE

To investigate the occurrence and clinical relevance of BME after third-generation ACI in the knee joint during the postoperative course of 36 months.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 38 circumscribed full-thickness cartilage defects in 30 patients were included in this study. All defects were treated with third-generation ACI (Novocart 3D). A standardized MRI examination was carried out after 1.5, 3, 6, 12, 24, and 36 months. Bone marrow edema was observed in 78.9% of defects over the postoperative course, with initial occurrence in the first 12 months. The size of the BMEs were determined according to their maximum diameter and were classified as small (<1 cm), medium (<2 cm), large (<4 cm), and very large (diffuse; >4 cm). Clinical outcomes in patients were analyzed by use of the International Knee Documentation Committee (IKDC) scoring system and a visual analog scale for pain.

RESULTS

There were 5.3% (n=2) small, 28.9% (n=11) medium, 34.2% (n=13) large, and 10.5% (n=4) very large BMEs. In a subgroup analysis, cartilage defects of the medial femoral condyle showed significantly higher frequency of BME than did patellar defects. Clinical scores showed significant improvements throughout the entire study course (P<.05). Clinical patient outcome did not correlate with presence of BME at any time period (P>.05).

CONCLUSION

Midterm clinical results of the matrix-based third-generation ACI showed a substantial amount of BME over a 36-month follow-up, but this did not correlate with worse clinical outcome. Patients with femoral cartilage defects were more often affected than were those with patellar cartilage defects.

Practical execution of defect preparation prior to surgical cartilage intervention: results from a representative meeting survey among experts

During a specialised orthopedic meeting held on ‘the state of the art in cartilage defect repair’, all previously fully-registered participants were requested to participate in an electronic survey by the use of a moderator-presented “Power Point Presentation-based” 9-item questionnaire. The aim of this survey was to assess indication, approach, and treatment execution of cartilage defect debridement prior to planned microfracture (MFX) or autologous chondrocyte implantation (ACI). All participants completed the questionnaire (n = 146) resulting in a return rate of 100 %. An uncertainty exists as to whether the removal of the calcifying layer prior to cartilage repair must be carried out or not. The same was true for the acceptability of subchondral bleeding prior to microfracturing and its handling prior to autologous chondrocyte implantation. There is a degree of unanimity among experts regarding the management of osteophytes and bone marrow edema. In a homogenous society collective of consultants that frequently deal with cartilage defective pathologies, there still remain a significant heterogeneity in selected topics of defect debridement.

Degree of preoperative subchondral bone edema is not associated with pain and graft outcomes after matrix-induced autologous chondrocyte implantation

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) is an established technique for the repair of knee chondral defects. While a number of factors may affect the clinical outcome, little is known about the influence of subchondral bone abnormalities at the time of surgery on pain and graft outcomes after MACI.

PURPOSE

To investigate the association between subchondral bone marrow edema within 3 months before MACI surgery on preoperative and postoperative reported pain and symptoms as well as postoperative graft outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This retrospective study was undertaken in 56 patients undergoing MACI with clinical and radiological assessments before surgery and at 3, 12, 24, and 60 months after surgery. Patients were assessed using the Pain and Symptoms subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS). High-resolution magnetic resonance imaging (MRI) was used to evaluate the severity of preoperative subchondral bone marrow edema, while graft infill and an MRI composite graft score were evaluated after surgery via the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system. Linear regression utilizing generalized estimating equations was used to investigate the association between preoperative subchondral bone marrow edema scores and preoperative and postoperative KOOS subscores as well as postoperative MRI-based scores of graft repair.

RESULTS

The degree of preoperative subchondral bone marrow edema was not significantly associated with postoperative outcomes, whereby there was no evidence of a difference between edema subgroups over all time points for the KOOS-Pain subscore (P = .644), KOOS-Symptoms subscore (P = .475), or MRI composite score (P = .685) after adjustment for potential confounders of age, body mass index, defect size, and defect location.

CONCLUSION

No association was demonstrated between the severity of preoperative subchondral bone marrow edema with postoperative patient-reported knee pain or symptoms or postoperative graft repair assessed via MRI.

Clinical outcomes after cell-seeded autologous chondrocyte implantation of the knee: when can success or failure be predicted?

BACKGROUND

Autologous chondrocyte implantation (ACI) has been associated with satisfying results. Still, it remains unclear when success or failure after ACI can be estimated.

PURPOSE

To evaluate the clinical outcomes of cell-seeded collagen matrix-supported ACI (ACI-Cs) for the treatment of cartilage defects of the knee at 36 months and to determine a time point after ACI-Cs at which success or failure can be estimated.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 80 patients with isolated full-thickness cartilage defects of the knee joint treated with ACI-Cs were prospectively assessed before surgery as well as postoperatively by use of the International Knee Documentation Committee (IKDC) score and Lysholm knee score.

RESULTS

Preoperative IKDC and Lysholm scores increased from 49.6 and 59.5, respectively, to 79.1 and 83.5, respectively, at 36 months. Only half the patients (46.6%) with poor IKDC scores (ie, <70) at 6 months postoperatively showed continued poor or fair scores at 36 months' follow-up. The probability of poor scores at 36 months after surgery further increased to 0.61 and 0.81, respectively, when scores were persistent at 12 and 24 months. All 3 patients (100%) with good IKDC scores (ie, 81-90) at 6 months after surgery showed constant or even improved scores at 36 months' follow-up. Ninety-one percent of patients with good and excellent scores at 12 months and 83% of patients with good and excellent scores at 24 months (a total of 23 and 37 patients, respectively) were able to maintain these scores at 36 months' follow-up. Similar results were obtained for the Lysholm score.

CONCLUSION

With regard to the improvements in functional outcomes after ACI-Cs at 36 months after surgery, the technique described here appears to lead to satisfying and stable clinical results. This study helps the treating physician to predict the likeliness of further clinical improvements or constant unsatisfactory results after ACI. In patients with good/excellent scores shortly after surgery, deterioration of the knee's condition is rarely found. For patients with poor and fair postoperative scores, clinical outcomes are more difficult to predict, especially during the first year after the procedure.

Long-term outcomes after first-generation autologous chondrocyte implantation for cartilage defects of the knee

BACKGROUND

Autologous chondrocyte implantation (ACI) represents an established surgical therapy for large cartilage defects of the knee joint. Although various studies report satisfying midterm results, little is known about long-term outcomes.

PURPOSE

To evaluate long-term clinical and magnetic resonance imaging (MRI) outcomes after ACI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between January 1997 and June 2001, a total of 86 patients were treated with ACI for isolated cartilage defects of the knee. The mean patient age at the time of surgery was 33.3 ± 10.2 years, and the mean defect size was 6.5 ± 4.0 cm(2). Thirty-four defects were located on the medial femoral condyle and 13 on the lateral femoral condyle, while 6 patients were treated for cartilage defects of the trochlear groove and 17 for patellar lesions. At a mean follow-up of 10.9 ± 1.1 years, 70 patients (follow-up rate, 82%) treated for 82 full-thickness cartilage defects of the knee were available for an evaluation of knee function using standard instruments, while 59 of these patients were additionally evaluated by 1.5-T MRI to quantify the magnetic resonance observation of cartilage repair tissue (MOCART) score. Clinical function at follow-up was assessed by means of the Lysholm score, the International Knee Documentation Committee (IKDC) score, and the Knee injury and Osteoarthritis Outcome Score (KOOS). Patient activity was assessed by the Tegner score. In addition, pain on a visual analog scale (VAS) and patient satisfaction were evaluated separately.

RESULTS

At follow-up, 77% reported being "satisfied" or "very satisfied." The mean IKDC score at follow-up was 74.0 ± 17.3. The mean Lysholm score improved from 42.0 ± 22.5 before surgery to 71.0 ± 17.4 at follow-up (P < .01). The mean pain score on the VAS decreased from 7.2 ± 1.9 preoperatively to 2.1 ± 2.1 postoperatively. The mean MOCART score was 44.9 ± 23.6. Defect-associated bone marrow edema was found in 78% of the cases. Nevertheless, no correlation between the MOCART score and clinical outcome (IKDC score) could be found (Pearson coefficient, r = 0.173).

CONCLUSION

First-generation ACI leads to satisfying clinical results in terms of patient satisfaction, reduction of pain, and improvement in knee function. Nevertheless, full restoration of knee function cannot be achieved. Although MRI reveals lesions in the majority of the cases and the overall MOCART score seems moderate, this could not be correlated with long-term clinical outcomes.

Factors predictive of outcome 5 years after matrix-induced autologous chondrocyte implantation in the tibiofemoral joint

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) has become an established technique for the repair of full-thickness chondral defects in the knee. However, little is known about what variables most contribute to postoperative clinical and graft outcomes as well as overall patient satisfaction with the surgery.

PURPOSE

To estimate the improvement in clinical and radiological outcomes and investigate the independent contribution of pertinent preoperative and postoperative patient, chondral defect, injury/surgery history, and rehabilitation factors to clinical and radiological outcomes, as well as patient satisfaction, 5 years after MACI.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study was undertaken in 104 patients of an eligible 115 patients who were recruited with complete clinical and radiological follow-up at 5 years after MACI to the femoral or tibial condyles. After a review of the literature, a range of preoperative and postoperative variables that had demonstrated an association with postoperative clinical and graft outcomes was selected for investigation. These included age, sex, and body mass index; preoperative 36-item Short Form Health Survey (SF-36) mental component score (MCS) and physical component score (PCS); chondral defect size and location; duration of symptoms and prior surgeries; and postoperative time to full weightbearing gait. The sport and recreation (sport/rec) and knee-related quality of life (QOL) subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) were used as the patient-reported clinical evaluation tools at 5 years, while high-resolution magnetic resonance imaging (MRI) was used to evaluate graft assessment. An MRI composite score was calculated based on the magnetic resonance observation of cartilage repair tissue score. A patient satisfaction questionnaire was completed by all patients at 5 years. Regression analysis was used to investigate the contribution of these pertinent variables to 5-year postoperative clinical, radiological, and patient satisfaction outcomes.

RESULTS

Preoperative MCS and PCS and duration of symptoms contributed significantly to the KOOS sport/rec score at 5 years, while no variables, apart from the baseline KOOS QOL score, contributed significantly to the KOOS QOL score at 5 years. Preoperative MCS, duration of symptoms, and graft size were statistically significant predictors of the MRI score at 5 years after surgery. An 8-week postoperative return to full weightbearing (vs 12 weeks) was the only variable significantly associated with an improved level of patient satisfaction at 5 years.

CONCLUSION

This study outlined factors such as preoperative SF-36 scores, duration of knee symptoms, graft size, and postoperative course of weightbearing rehabilitation as pertinent variables involved in 5-year clinical and radiological outcomes and overall satisfaction. This information may allow orthopaedic surgeons to better screen their patients as good candidates for MACI, while allowing treating therapists to better individualize their preoperative preparatory and postoperative rehabilitation regimens for a best possible outcome.

Comparing Responsiveness of Six Common Patient-Reported Outcomes to Changes Following Autologous Chondrocyte Implantation: A Systematic Review and Meta-Analysis of Prospective Studies

OBJECTIVE

To compare the responsiveness of six common patient-reported outcomes (PROs) following autologous chondrocyte implantation (ACI).

DESIGN

A systematic search was conducted to identify reports of PROs following ACI. Study quality was evaluated using the modified Coleman Methodology Score (mCMS). For each outcome score, pre- to postoperative paired Hedge's g effect sizes were calculated with 95% confidence intervals (CIs). Random effects meta-analyses were performed to provide a summary response for each PRO at time points (TP) I (<1 year), II (1 year to <2 years), III (2 years to <4 years), IV (≥4 years), and overall.

RESULTS

The mean mCMS for the 42 articles included was 50.9 ± 9.2. For all evaluated instruments, none of the mean effect size CIs encompassed zero. The International Knee Documentation Committee Subjective Knee Form (IKDC) had increasing responsiveness over time with TP-IV, demonstrating greater mean effect size [confidence interval] (1.78 [1.33, 2.24]) than TP-I (0.88 [0.69, 1.07]). The Knee Injury and Osteoarthritis Outcome Score-Sports and recreation subscale (KOOS-Sports) was more responsive at TP-III (1.76 [0.87, 2.64]) and TP-IV (0.98 [0.81, 1.15]) than TP-I (0.61 [0.44, 0.78]). Overall, the Medical Outcomes Study 36-Item Short Form Health Survey Physical Component Scale (0.60 [0.46, 0.74]) was least responsive. Both the Lysholm Scale (1.42 [1.14, 1.72]) and the IKDC (1.37 [1.13, 1.62]) appear more responsive than the KOOS-Sports (0.90 [0.73, 1.07]). All other KOOS subscales had overall effect sizes ranging from 0.90 (0.74, 1.22) (Symptoms) to 1.15 (0.76, 1.54) (Quality of Life).

CONCLUSIONS

All instruments were responsive to improvements in function following ACI. The Lysholm and IKDC were the most responsive instruments across time. IKDC and KOOS-Sports may be more responsive to long-term outcomes, especially among active individuals.

Early clinical and structural results after autologous chondrocyte transplantation at the glenohumeral joint

BACKGROUND

The purpose of the study was to report early functional and radiographic results of a small series of patients who underwent autologous chondrocyte transplantation-collagen membrane seeding (ACT-Cs) for focal chondral defects of the shoulder.

METHODS

The outcome of 4 consecutive male patients (mean age, 29.3 ± 6.2 years; range, 21-36 years) who underwent ACT-Cs for treatment of large symptomatic glenohumeral cartilage defects was retrospectively evaluated with clinical and radiographic measures at a mean of 41.3 ± 24.9 months (range, 11-71 months) after surgery. The evaluation included a visual analog scale for pain, the Constant score, the American Shoulder and Elbow Surgeons shoulder index, the Rowe score, and a satisfaction scale. Magnetic resonance imaging evaluation was performed according to the Magnetic Resonance Observation of Cartilage Repair Tissue scoring system.

RESULTS

There were 3 humeral full-thickness cartilage defects (each 6.0 cm(2)) and 1 glenoid full-thickness cartilage defect (2.0 cm(2)). The mean postoperative visual analog scale score (0.3 of 10), the mean unweighted Constant score (83.3 ± 9.9), and the mean American Shoulder and Elbow Surgeons index (95.3 ± 8.1) were representative of satisfactory shoulder function. The Magnetic Resonance Observation of Cartilage Repair Tissue score was indicative of satisfactory defect coverage with signs of fibrocartilaginous repair tissue.

CONCLUSIONS

Autologous chondrocyte transplantation at the glenohumeral joint is a remote option for young adults with symptomatic, isolated, large-diameter cartilage lesions. Potential complications as a result of the open approach and 2-step procedure have to be considered carefully. Long-term data, larger patient populations, and randomized studies are required to determine the potential for chondrocyte transplantation techniques to be standard procedure for treatment of symptomatic, large-diameter, full-thickness cartilage defects in the glenohumeral joint.

Expression of BMP-receptor type 1A correlates with progress of osteoarthritis in human knee joints with focal cartilage lesions

BACKGROUND AIMS

Bone morphogenetic protein-2 (BMP-2) and its receptor type 1A (BMPR-1A) play significant roles in cartilage metabolism. The aim of this study was to evaluate a possible correlation between intra-articular expression of these proteins and the degree of osteoarthritis (OA) in human knees.

METHODS

Biopsies of synovia and debrided cartilage were taken in 15 patients undergoing autologous chondrocyte implantation. Expression of BMP-2 and BMPR-1A was evaluated semi-quantitatively by immunohistologic staining. These data were complemented by grading of cartilage lesions according to International Cartilage Repair Society (ICRS), defect size, duration of complaints, knee osteoarthritis scoring system (KOSS) and Henderson and Kellgren-Lawrence scores. General histologic stainings were used to determine Mankin, Pritzker and Krenn scores.

RESULTS

The expression of BMPR-1A but not of BMP-2 was significantly higher in cartilage biopsies taken in type 3 lesions with intact subchondral layer compared with type 4 defects (P < 0.05). In cartilage areas of bordering sectors, the intensity of immunohistologic staining of BMPR-1A was statistically significantly higher in mature cartilage compared with repair zones (P < 0.05). Expression of BMP-2 and its receptor 1A correlated in the cartilage biopsies (P < 0.02) but not in the synovia. The degree of OA was scored in all biopsies according to Mankin and Pritzker, and these scores correlated statistically significantly with BMPR-1A expression in the synovia (P < 0.05). In patients with an osteochondritis dissecans, the degree of OA was higher compared with other causes of chondromalacia, as evaluated by defect size, ICRS score, duration of complaints, Pritzker score and expression of BMPR-1A in cartilage (P < 0.05).

CONCLUSIONS

These data support the role of BMPR-1A as an indicator of OA progression in human knees with circumscribed cartilage lesions.

Clinical outcome of autologous chondrocyte implantation for failed microfracture treatment of full-thickness cartilage defects of the knee joint

BACKGROUND

Although various factors have been identified that influence outcome after autologous chondrocyte implantation (ACI), the relevance of prior treatment of the cartilage defect and its effect concerning the outcome of second-line ACI have not been evaluated to a full extent.

HYPOTHESIS

Autologous chondrocyte implantation used as a second-line treatment after failed arthroscopic microfracturing is associated with a higher failure rate and inferior clinical results compared with ACI as a first-line treatment.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 28 patients with isolated cartilage defects at the knee joint were treated with ACI after microfracture as a first-line treatment had failed (failure defined as the necessity of reintervention). These patients were assigned to group A and compared with a matched-pair cohort of patients of identical age, defect size, and defect location (group B) in which ACI was used as a first-line treatment. Failure rates in both groups were assessed. Postoperative knee status was evaluated with the International Knee Documentation Committee (IKDC) score and Knee injury and Osteoarthritis Outcome Score (KOOS), and sporting activity was assessed by use of the Activity Rating Scale. Mean follow-up times were 48.0 months (range, 15.1-75.1 months) in group A and 41.4 months (range, 15.4-83.6 months) in group B. Differences between groups A and B were analyzed by Student t test.

RESULTS

Group A had significantly greater failure rates (7 of 28 patients) in comparison with group B (1 of 28 patients; P = .0241). Mean (SD) postoperative IKDC scores revealed 58.4 (22.4) points in group A with a trend toward higher score results (69.0 [19.1] points) for patients in group B (P = .0583). Significantly different results were obtained for KOOS pain and activity of daily living subscales, whereas the remaining KOOS subscales did not show significant differences. Despite the significantly higher failure rate observed in group A, those patients did not participate in fewer activities or perform physical activity less frequently or at a lower intensity.

CONCLUSION

Autologous chondrocyte implantation after failed microfracturing appears to be associated with a significantly higher failure rate and inferior clinical outcome when compared with ACI as a first-line treatment.

Immunohistological localization of BMP-2, BMP-7, and their receptors in knee joints with focal cartilage lesions

Introduction. Although it is well known that BMP-2 and BMP-7 play significant roles in cartilage metabolism, data about intra-articular expression and localization of these proteins and their receptors in humans are rare. Methods. Biopsies of synovia and debrided cartilage were taken in patients undergoing autologous chondrocyte implantation. Expression of BMP-2, BMP-7, and their receptors BMPR-1A, BMPR-1B and BMPR-2 were semiquantitatively evaluated by immunohistological staining. Results. BMP-7 was equally highly expressed in all cartilage and synovial biopsies. Increased levels of BMPR-1A, but not of BMPR-1B, and BMPR-2, were found in all synovial and 47% of all cartilage samples (P = 0.002). BMP-2 was positively scored in 47% of all cartilage and 40% of all synovial specimens. Defect size, KOSS, Henderson or Kellgren-Lawrence score did not statistically significant correlate with the expression of the analyzed proteins or Mankin and Pritzker scores. Duration of symptoms and localization of lesions were associated with KOSS (P < 0.02), but there was no influence of these parameters on protein expression. Conclusions. BMP-2, BMP-7, and BMPR-1A were expressed in cartilage and synovia of knees with focal cartilage lesions. Although defect localization and duration of symptoms decisively influence KOSS, there was no associated alteration of protein expression observed.

Pain perception in knees with circumscribed cartilage lesions is associated with intra-articular IGF-1 expression

BACKGROUND

Circumscribed cartilage defects are considered as prearthritic lesions and lead to differential intra-articular cytokine expression. Mechanisms of associated pain development and influence of smoking behavior are not yet fully understood in humans.

PURPOSE

This study aimed to reveal relations between synovial cytokine levels in knees with circumscribed cartilage defects and pain sensation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

In a clinical trial, knee lavage fluids of 42 patients with circumscribed cartilage lesions treated by either microfracturing (n = 19) or by autologous chondrocyte implantation (n = 23) and fluids of 5 healthy control individuals were prospectively collected. Preoperative knee pain was evaluated according to frequency and strength; subjective knee function was assessed using a visual analog scale and the International Knee Documentation Committee (IKDC) score. Synovial concentrations of aggrecan, insulin-like growth factor (IGF)-I, basic fibroblast growth factor (bFGF), interleukin (IL)-1β, bone morphogenetic protein (BMP)-2, and BMP-7 were determined by enzyme-linked immunosorbent assay.

RESULTS

Pain strength showed a highly significant association with intra-articular IGF-1 levels (ρ = .48, P < .01), but no correlation with synovial concentrations of aggrecan, bFGF, IL-1β, BMP-2, and BMP-7. Although pain strength and frequency demonstrated a statistically significant relationship, no substantial association between pain frequency and any of the examined cytokine levels was found. Intra-articular IGF-1 concentrations significantly correlated with the area of cartilage damage (ρ = .35, P < .02); the other investigated cytokines failed to show this association. Neither of the determined intra-articular mediators demonstrated statistically significant correlations with subjective knee function or IKDC score. Only intra-articular concentrations of IGF-1 and BMP-2 statistically significantly correlated with age; total protein content was negatively associated with body mass index (P < .05). In smokers, synovial expression of total protein content, IGF-1, and bFGF was significantly diminished compared to nonsmokers (P < .05).

CONCLUSION

Insulin-like growth factor-I is present in knees with circumscribed cartilage lesions in a size-dependent manner. IGF-1 levels correlated with indicators of pain perception; smoking negatively influenced synovial cytokine expression related to cartilage metabolism, but pain perception was not altered.