Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

Quantitative Relaxometry Metrics for Brain Metastases Compared to Normal Tissues: A Pilot MR Fingerprinting Study

The purpose of the present pilot study was to estimate T1 and T2 metric values derived simultaneously from a new, rapid Magnetic Resonance Fingerprinting (MRF) technique, as well as to assess their ability to characterize-brain metastases (BM) and normal-appearing brain tissues. Fourteen patients with BM underwent MRI, including prototype MRF, on a 3T scanner. In total, 108 measurements were analyzed: 42 from solid parts of BM's (21 each on T1 and T2 maps) and 66 from normal-appearing brain tissue (11 ROIs each on T1 and T2 maps for gray matter [GM], white matter [WM], and cerebrospinal fluid [CSF]). The BM's mean T1 and T2 values differed significantly from normal-appearing WM (p < 0.05). The mean T1 values from normal-appearing GM, WM, and CSF regions were 1205 ms, 840 ms, and 4233 ms, respectively. The mean T2 values were 108 ms, 78 ms, and 442 ms, respectively. The mean T1 and T2 values for untreated BM (n = 4) were 2035 ms and 168 ms, respectively. For treated BM (n = 17) the T1 and T2 values were 2163 ms and 141 ms, respectively. MRF technique appears to be a promising and rapid quantitative method for the characterization of free water content and tumor morphology in BMs.

Maturation process of regenerated tissues after single-stage simultaneous autologous particulated cartilage implantation and open wedge high tibial osteotomy for articular cartilage defects with medial osteoarthritis of bilateral knees: a case report

Background

Open wedge high tibial osteotomy (OWHTO) is an effective treatment option for young and middle-aged active patients with medial unicompartmental knee osteoarthritis (OA). In addition, particulated cartilage implantation has been developed as a simple procedure for cartilage regeneration. Thus, to improve the OWHTO outcomes, a single-stage, simultaneous bilateral knee arthroscopic particulated cartilage implantation with OWHTO was performed.

Case presentation

A 60-year-old male patient presented with severe bilateral knee pain, with grade 2 varus knee OA of the Kellgren–Lawrence classification. Primary arthroscopic evaluations based on the International Cartilage Repair Society grading system showed grade 3c articular cartilage defects of 1.5 cm in diameter at the center of the bilateral medial femoral condyles. Following bilateral OWHTO, the healthy cartilage tissue was harvested from the lateral wall of the unilateral femoral intercondylar notch and minced with the cartilage processor. Then, subchondral drillings and cartilage fragment implantations into the bilateral defects were performed arthroscopically. One year postsurgery, second-look arthroscopy findings revealed that the defects were filled with cartilage-like tissues. The maturation process of the regenerated tissues was confirmed with T2 mapping magnetic resonance imaging during the 3-year follow-up period. The patient could walk without a cane, and all Knee Injury and Osteoarthritis Outcome Score parameters were improved without any correction loss in 3 years.

Conclusions

This is the first report to evaluate the maturation process of the implanted particulated cartilage tissue with T2 mapping magnetic resonance imaging for 3 years. The effect of chondral resurfacing procedure with OWHTO remains unclear; however, the implantation of arthroscopic particulated cartilage fragments is a single-stage and less-invasive procedure. This treatment could regenerate cartilage-like tissue in the present case. Therefore, this additional procedure could potentially improve the long-term outcomes of OWHTO.

Magnetic Resonance Imaging Evaluation of Cartilage Repair and Iron Particle Kinetics After Magnetic Delivery of Stem Cells

IMPACT STATEMENT

This study is very important as a preclinical study of magnetic resonance imaging (MRI) assessment after magnetic targeting of mesenchymal stem cells. The findings of this study show that MRI is useful for evaluating the regenerative process of cartilage with magnetic targeting and kinetics of iron particles, and is less invasive without any complications.

Effect of Bisphosphonate Pretreatment on Fresh Osteochondral Allografts: Analysis of In Vitro Graft Structure and In Vivo Osseous Incorporation

Fresh allograft transplantation of osteochondral defects restores functional articular cartilage and subchondral bone; however, rapid loss of chondrocyte viability during storage and osteoclast-mediated bone resorption at the graft-host interface after transplantation negatively impact outcomes. The authors present a pilot study evaluating the in vitro and in vivo impact of augmenting storage media with bisphosphonates. Forty cylindrical osteochondral cores were harvested from femoral condyles of human cadaveric specimens and immersed in either standard storage media or storage media supplemented with nitrogenated or non-nitrogenated bisphosphonates. Maintenance of graft structure and chondrocyte viability were assessed at 3 time points. A miniature swine trochlear defect model was used to evaluate the influence of bisphosphonate-augmented storage media on in vivo incorporation of fresh osteochondral tissue, which was quantified via μCT and decalcified histology. In the in vitro study, Safranin-O/Fast Green staining showed that both low- and high-dose nitrogenated-treated grafts retained chondrocyte viability and cartilage matrix for up to 43 days of storage. Allografts stored in nitrogenated-augmented storage media showed both μCT and histologic evidence of enhanced in vivo bony and cartilaginous incorporation in the miniature swine trochlear defect model. Several preclinical studies have shown the potential for enhanced storage of fresh osteochondral allografts via additions of relatively common drugs and biomolecules. This study showed that supplementing standard storage media with nitrogenated bisphosphonates may improve maintenance of chondrocyte viability and graft structure during cold storage as well as enhance in vivo osseous and cartilaginous incorporation of the graft. [Orthopedics: 2018; 41(3):e376-e382.].

A new point of view for mosaicplasty in the treatment of focal cartilage defects of knee joint: honeycomb pattern

BACKGROUND

A focal full thickness cartilage lesion of knee joint is one of the commonly seen intraarticular pathologies among the joint cartilage problems. Osteochondral autograft transfer mosaicplasty is a method which has satisfactory outcomes among the treatment preferences of cartilage defects. In spite of the favorable clinical results there are some pitfalls of mosaicplasty treatment especially in cases of large defects. One of the major problems of the classical OAT mosaicplasty is the gap spaces between the plugs. The objective of the present study is to report the early clinical and radiological outcomes and to evaluate the clinical application of a new hexagonal osteochondral graft system (HOGS) with the hypothesis of improvement of the OAT mosaicplasty method with the use of hexagonally shaped plugs. The study has intended to answer two questions. (1) Does mosaicplasty with the new HOGS has favorable early clinical outcomes? (2) Is it possible to arrange the osteochondral autografts without leaving gap spaces by using hexagonal pattern in OAT mosaicplasty?

PATIENTS AND METHODS

We designed a retrospective study to report analysis of early outcomes of the initial case series of OAT mosaicplasty by using a new HOGS. Six male individuals with the diagnosis of osteochondral defect and treated with HOGS and reached sixth month follow-up formed the basis of the study. The clinical status of the patients were evaluated with IKDC score. The radiological evaluations were carried out with direct X-rays and magnetic resonance imaging (MRI) studies. The mosaicplasty procedures were carried out via standard surgical method of classical OAT mosaicplasty by using the HOGS following a diagnostic arthroscopy in the same session. The inclusion criteria was a full thickness osteochondral lesion of femoral condyle between 1.5 and 6 cm(2) and completion of 6 month follow-ups. The patients having deformities around the knee or major ligament lesions were excluded. MOCART scoring system was used for the evaluation of follow-up MRI findings. The clinical status of the patients were evaluated with IKDC scores.

RESULTS

The mean age of the patients was 40.8 (±5.2) years and the mean duration of the symptoms on presentation was 16 (±4.3) months. On the initial MRI studies mean defect area was measured 3.7 cm(2) (±0.9) which was compatible with arthroscopic findings. During the surgical procedures it was possible to fill the defect area completely. The mean number of plugs in this series was 4.8 (±1.1). We did not faced with insufficient donor reserve problem in any of the cases. On the sixth month follow-up physical examination there was no limitation of the knee joint range of motion in the cases. All patients were able to bear weight on to their operated extremities without pain. The mean postoperative IKDC score improvement was 70.2 (±3.5) which shows significant improvement compared to preoperative scores. On the control MRI studies the bone integration of the hexagonal plugs were complete the cartilage continuity of the articular surfaces were intact and the grafts were well incorporated in all cases. The mean MOCART score on the 6th month MRI studies was 65.8 (±4.1).

CONCLUSION

The early outcomes of OAT mosaicplasty with HOGS are comparable to studies on the classical mosaicplasty. According to our observations in this study we can say that the gap space left between the cylindrical plugs can be solved by using hexagonal prism shaped plugs.

Variation in haemodynamic monitoring for major surgery in European nations: secondary analysis of the EuSOS dataset

Background

The use of cardiac output monitoring may improve patient outcomes after major surgery. However, little is known about the use of this technology across nations.

Methods

This is a secondary analysis of a previously published observational study. Patients aged 16 years and over undergoing major non-cardiac surgery in a 7-day period in April 2011 were included into this analysis. The objective is to describe prevalence and type of cardiac output monitoring used in major surgery in Europe.

Results

Included in the analysis were 12,170 patients from the surgical services of 426 hospitals in 28 European nations. One thousand four hundred and sixteen patients (11.6 %) were exposed to cardiac output monitoring, and 2343 patients (19.3 %) received a central venous catheter. Patients with higher American Society of Anesthesiologists (ASA) scores were more frequently exposed to cardiac output monitoring (ASA I and II, 643 patients [8.6 %]; ASA III–V, 768 patients [16.2 %]; p < 0.01) and central venous catheter (ASA I and II, 874 patients [11.8 %]; ASA III–V, 1463 patients [30.9 %]; p < 0.01). In elective surgery, 990 patients (10.8 %) were exposed to cardiac output monitoring, in urgent surgery 252 patients (11.7 %) and in emergency surgery 173 patients (19.8 %). A central venous catheter was used in 1514 patients (16.6 %) undergoing elective, in 480 patients (22.2 %) undergoing urgent and in 349 patients (39.9 %) undergoing emergency surgery. Nine hundred sixty patients (7.9 %) were monitored using arterial waveform analysis, 238 patients (2.0 %) using oesophageal Doppler ultrasound, 55 patients (0.5 %) using a pulmonary artery catheter and 44 patients (2.0 %) using other technologies. Across nations, cardiac output monitoring use varied from 0.0 % (0/249 patients) to 27.5 % (19/69 patients), whilst central venous catheter use varied from 5.6 % (7/125 patients) to 43.2 % (16/37 patients).

Conclusions

One in ten patients undergoing major surgery is exposed to cardiac output monitoring whilst one in five receives a central venous catheter. The use of both technologies varies widely across Europe.

Trial registration

ClinicalTrials.gov Identifier: NCT01203605. Date of registration: 15.09.2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13741-015-0018-8) contains supplementary material, which is available to authorized users.