Histological scoring systems for tissue-engineered, ex vivo and degenerative meniscus

Purpose

Because its function is strictly related to the quality of meniscal tissue, one of the most important outcome measures for the evaluation of meniscal repair effectiveness is the assessment of histological features. Data on the validation and application of the histological scoring systems in research settings and specific fields of meniscal disorders are lacking. The available histological scoring systems to assess meniscal tissue were systematically evaluated.

Methods

Histological scoring systems for the analysis of degenerative meniscal changes, ex vivo and tissue-engineered meniscal repair were reviewed. Furthermore, the validity and applicability of the scoring systems were assessed.

Results

The Copenhaver classification and Mankin score have been modified to classify the degeneration of collagen bundles in the meniscal structure. The Pauli score seems to be a comprehensive and simple scoring system for the evaluation of both macroscopic and histologic meniscal changes related to ageing and osteoarthritic degeneration. The Zhang score may be used for ex vivo gene therapy in meniscus healing. The Ishida score seems to be the most adequate for the evaluation of tissue-engineered meniscal repair.

Conclusion

Although several histological scoring systems are available to assess meniscal structure, only few of them have been validated for specific application in research settings. Validated scores are required to provide a standardized data collection to allow the comparison of results of different research groups. Further experimental and clinical studies are needed to find a comprehensive and validated histological scoring system in the field of meniscus repair.

Level of evidence

Systematic review of Level III studies, Level III.     

The burden of hard atherosclerotic plaques does not promote endoleak development after endovascular aortic aneurysm repair: a risk stratification

Purpose  

To objectify the influence of the atherosclerotic burden in the proximal landing zone on the development of endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) or thoracic endovascular aneurysm repair (TEVAR) using objective aortic calcium scoring (ACS).     

Is Embolization of the Pancreas Safe? Pancreatic Histological Changes after Selective Transcatheter Arterial Embolization with N-Butyl Cyanoacrylate in a Swine Model

Purpose  

This study was designed to evaluate the safety of selective transcatheter arterial embolization (TAE) with N-butyl cyanoacrylate (NBCA) in a swine model in terms of histological changes in the pancreas.     

Detection of Type II Endoleak After Endovascular Aortic Repair: Comparison Between Magnetic Resonance Angiography and Blood-Pool Contrast Agent and Dual-Phase Computed Tomography Angiography

Purpose  

This prospective study was designed to assess the diagnostic value of magnetic resonance angiography (MRA) with blood-pool contrast agent (gadofosveset) in the detection of type-II endoleak after endovascular aortic repair (EVAR).     

Intraoperative Sac Pressure Measurement During Endovascular Abdominal Aortic Aneurysm Repair

Purpose  

Intraoperative sac pressure was measured during endovascular abdominal aortic aneurysm repair (EVAR) to evaluate the clinical significance of sac pressure measurement.     

Endovascular Treatment of Delayed Type 1 and 3 Endoleaks

Purpose  

Endovascular aortic aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysms. Type I and III endoleaks require prompt, definitive repair or explantation. We review a single center experience of endovascular treatment of type I and III endoleaks.     

Biomechanical evaluation of four different transosseous-equivalent/suture bridge rotator cuff repairs

Purpose  

Evaluate the biomechanical behavior of four variants of the transosseous-equivalent/suture bridge (TOE/SB) repair.     

Failed cartilage repair for early osteoarthritis defects: a biochemical, histological and immunohistochemical analysis of the repair tissue after treatment with marrow-stimulation techniques

Purpose

To examine the entire repair tissue resulting from marrow-stimulation techniques in patients with early osteoarthritis.

Methods

The repair tissue and adjacent articular cartilage after failed marrow-stimulation techniques (microfracture and Pridie drilling) of 5 patients (47–65 years old) with cartilage defects and radiographic early osteoarthritis (Kellgren–Lawrence grading 1 and 2) was removed during total joint arthroplasty (mean time until analysis: 8.8 months), analysed by histology, polarized light microscopy, immunohistochemistry, biochemistry and by histological score systems.

Results

Macroscopic cartilage repair assessment revealed ICRS grades of II (nearly normal) and III (abnormal). Cartilage defects were mostly completely filled with a fibrocartilaginous tissue that had small and large fissures. Cartilage-specific stains of the repair tissue were more intense than the surrounding native cartilage but reduced compared with normal articular cartilage. The subchondral bone was incompletely restored. A new tidemark was absent. The repair tissue always showed positive immunoreactivity for types II and X collagen, and was sometimes positive for type I collagen. Proteoglycan contents of the repair tissue were generally higher than of the surrounding cartilage. The repair tissue was always more cellular than the adjacent articular cartilage. Histological scoring of the repair tissue revealed a mean Sellers score of 17.6 ± 3.0 and an ICRS grading of 7–9.

Conclusion

Failed marrow stimulation of articular cartilage defects in patients with early osteoarthritis is characterized by fibrocartilaginous repair. The balance of cell number to extracellular matrix is shifted towards an increased cell number in this tissue. Articular cartilage repair did not reach the quality of normal hyaline articular cartilage.

Level of evidence

IV.     

Enhancement of rotator cuff tendon–bone healing with injectable periosteum progenitor cells-BMP-2 hydrogel in vivo

Purpose  

The fixation and incorporation of ruptured rotator cuff tendon to bone is a major concern in rotator cuff repair surgery. Rotator cuff repair usually fails at the tendon–bone interface, especially in case of large or massive tears. To enhance tendon–bone healing, an injectable hydrogel made with periosteal progenitor cells(PPCs) and poly (ethylene glycol) diacrylate (PEGDA) tethered with bone morphogenic protein-2(BMP-2) was developed to encourage extracellular matrix synthesis for tendon-to-bone healing in rotator cuff repair.     

Anterior labroligamentous periosteal sleeve avulsion lesion in arthroscopic capsulolabral repair for anterior shoulder instability

Purpose  

This study aims to compare the associated lesions, clinical results, and postoperative recurrence rates in patients with ALPSA lesions (ALPSA group) versus those with Bankart lesions or Perthes lesions (Bankart group) in arthroscopic capsulolabral repair for anterior shoulder instability.     

Meniscal repair in anterior cruciate ligament reconstruction: a long-term outcome study

Purpose  

To study the long-term outcome of patients who have undergone inside-out, vertical stacked mattress suture repair of meniscal tears combined with anterior cruciate ligament (ACL) reconstruction.     

The use of the Tegner Activity Scale for articular cartilage repair of the knee: a systematic review

Purpose  

The Tegner Activity Scale (TAS) was developed in 1984 and has been widely used in studies on knee populations. The primary objective of this study was to undertake a systematic review on the use of the TAS for articular cartilage repair (ACR) of the knee.     

Clinical and structural evaluation of arthroscopic double-row suture-bridge rotator cuff repair: early results of a novel technique

Purpose  

Assessment of repair integrity and clinical outcome after arthroscopic repair of rotator cuff tears in double-row suture-bridge technique with the use of a new knotless suture-anchor system.     

Mucoid degeneration of the anterior cruciate ligament: MRI, clinical, intraoperative, and histological findings

Purpose  

To describe the clinical, MRI, intraoperative, and histological features of mucoid degeneration of the anterior cruciate ligament (ACL).     

Surgical repair of the distal biceps brachii tendon: a comparative study of three surgical fixation techniques

Purpose  

Several fixation techniques exist to repair the distal biceps brachii tendon. We aimed to evaluate the clinical and functional outcomes after distal biceps tendon repair using three different fixation techniques.     

Transplanted articular chondrocytes co-overexpressing IGF-I and FGF-2 stimulate cartilage repair in vivo

Purpose

The combination of chondrogenic factors might be necessary to adequately stimulate articular cartilage repair. In previous studies, enhanced repair was observed following transplantation of chondrocytes overexpressing human insulin-like growth factor I (IGF-I) or fibroblast growth factor 2 (FGF-2). Here, the hypothesis that co-overexpression of IGF-I and FGF-2 by transplanted articular chondrocytes enhances the early repair of cartilage defects in vivo and protects the neighbouring cartilage from degeneration was tested.

Methods

Lapine articular chondrocytes were transfected with expression plasmid vectors containing the cDNA for the Escherichia coli lacZ gene or co-transfected with the IGF-I and FGF-2 gene, encapsulated in alginate and transplanted into osteochondral defects in the knee joints of rabbits in vivo.

Results

After 3 weeks, co-overexpression of IGF-I/FGF-2 improved the macroscopic aspect of defects without affecting the synovial membrane. Immunoreactivity to type-I collagen, an indicator of fibrocartilage, was significantly lower in defects receiving IGF-I/FGF-2 implants. Importantly, combined IGF-I/FGF-2 overexpression significantly improved the histological repair score. Most remarkably, such enhanced cartilage repair was correlated with a 2.1-fold higher proteoglycan content of the repair tissue. Finally, there were less degenerative changes in the cartilage adjacent to the defects treated with IGF-I/FGF-2 implants.

Conclusion

The data demonstrate that combined gene delivery of therapeutic growth factors to cartilage defects may have value to promote cartilage repair. The results also suggest a protective effect of IGF-I/FGF-2 co-overexpression on the neighbouring articular cartilage. These findings support the concept of implementing gene transfer strategies for articular cartilage repair in a clinical setting.     

MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis

Objective

To investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation.

Methods

Forty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS, n?=?24) or phosphate buffered saline (PBS, n?=?24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared.

Results

The distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration.

Conclusion

Nerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis.

Key points

? TLR4 activation had additional beneficial effects on neurotmesis beyond surgical repair. ? TLR4 activation had a characteristic time course of T2 values. ? T2 measurements can help detect beneficial effects with TLR4 activation.     

Determination of the safe penetration depth during all-inside meniscal repair of the posterior part of the lateral meniscus using the FasT-Fix suture repair system

Purpose  

The objective of this study was to determine the safe penetration depth of the FasT-Fix meniscal suture repair system during all-inside repair of the posterior part of the lateral meniscus.     

Clinical outcomes of medial patellofemoral ligament repair in recurrent (chronic) lateral patella dislocations

Purpose  

The specific aim of this project was to review a homogenous group of patients who had chosen to undergo medial patellofemoral ligament (MPFL) repair to stabilize their patella after repeat (chronic) patellofemoral dislocations and to record the success of this procedure in stabilizing the patella against further lateral dislocations.     

4D-MR flow analysis in patients after repair for tetralogy of Fallot

Objectives  

Comprehensive analysis of haemodynamics by 3D flow visualisation and retrospective flow quantification in patients after repair of tetralogy of Fallot (TOF).