Autologous chondrocyte implantation to repair knee cartilage injury: ultrastructural evaluation at 2 years and long-term follow-up including muscle strength measurements

Autologous chondrocyte implantation (ACI) usually results in improvement in clinical scores. However, long-term isokinetic muscle strength measurements have not been reported. Biopsies from the repair tissue have shown variable proportions of hyaline-like cartilage. In this study, 21 consecutive patients were treated with autologous cartilage implantations in the knee. Mean size of the lesions was 5.5 cm². Follow-up arthroscopy with biopsy was performed at 2 years in 19 patients. The biopsies were examined with both light microscopy and transmission electron microscopy (TEM) techniques including immunogold analysis of collagen type 1. Patient function was evaluated with modified 10-point scales of the Cincinnati knee rating system obtained preoperatively and at 1 and 8.1 years. Isokinetic quadriceps and hamstrings muscle strength testing was performed at 1, 2 and 7.4 years. Light microscopy and TEM both showed predominately fibrous cartilage. The immunogold analysis showed a high percentage of collagen type I. At 7.4 years, the total work deficits when compared with the contra-lateral leg for isokinetic extension were 19.1 and 11.4%, and for isokinetic flexion 11.8 and 8.5% for 60 and 240o/s, respectively. Mean pain score improved from 4.3 preoperatively to 6.3 at 1 year (p = 0.031) and 6.6 at 8.1 years (p = 0.013). Overall health condition score improved from 4.1 preoperatively to 6.1 at 1 year (p = 0.004) and 6.5 at 8.1 years (p = 0.008). Three patients later went through revision surgery with other resurfacing techniques and are considered failures. In summary, the formation of fibrous cartilage following ACI was confirmed by TEM with immunogold histochemistry. Although the functional scores were generally good, strength measurements demonstrated that the surgically treated leg remained significantly weaker.     

Hydrogel implant is as effective as osteochondral autologous transplantation for treating focal cartilage knee injury in 24 months

Purpose

The treatment approach for a patient with knee joint focal cartilage lesion is a difficult decision. To date, there has been no randomized clinical trial involving Hydrogel (Cartiva?). This study evaluated and compared the results of a hydrogel implant (Cartiva?) with autologous osteochondral transplantation (AOT) for treating knee joint focal cartilage lesions.

Methods

Thirty-eight symptomatic patients, with a focal cartilage lesion of Outerbridge grades III or IV, were randomized into one of two groups according to the inclusion and exclusion criteria. Group I underwent AOT, and Group II was treated with a Hydrogel implant. Patients were evaluated preoperatively and again postoperatively at 6, 12, and 24 months using the subjective International Knee Documentation Committee (IKDC) scores, Visual Analog Scale for Pain (VAS Pain), Activities of Daily Living Scale (ADLS) and Lysholm score.

Results

Both groups showed significant improvements from baseline (pre-surgery) to post-surgery (6, 12, and 24 months; p?<?0.05), but there was no difference between the groups. Regarding complications, prolonged pain was observed in four patients (10.5%), two from each group, with a regression of symptoms within 1 year.

Conclusion

The Hydrogel implant showed similar efficiency as the autologous osteochondral graft for treating knee joint focal cartilage lesions. Both techniques showed satisfactory results compared to preoperative status. The Hydrogel implant was safe and effective, and it provided good stability and joint function at 2-year follow-up.

Level of evidence

I.

     

Assessing PreCR™ repair enzymes for restoration of STR profiles from artificially degraded DNA for human identification

Forensic scientists have used several approaches to obtain short tandem repeat (STR) profiles from compromised DNA samples, including supplementing the polymerase chain reaction (PCR) with enhancers and using procedures yielding reduced-length amplicons. For degraded DNA, the peak intensities of the alleles separated by electrophoresis generally decrease as the length of the allele increases. When the intensities of the alleles decrease below an established threshold, they are described as drop-outs, thus contributing to a partial STR profile. This work assesses the use of repair enzymes to improve the STR profiles from artificially degraded DNA. The commercial PreCR™ repair kit of DNA repair enzymes was tested on both purified DNA and native DNA in body fluids exposed to oxidizing agents, hydrolytic conditions, ultraviolet (UV) and ionizing radiation, and desiccation. The strategy was to restrict the level of DNA damage to that which yields partial STR profiles in order to test for allele restoration as opposed to simple allele enhancement. Two protocols were investigated for allele restoration: a sequential protocol using the manufacturer's repair procedure and a modified protocol reportedly designed for optimal STR analysis of forensic samples. Allele restoration was obtained with both protocols, but the peak height appeared to be higher for the modified protocol (determined by Mann–Kendall Trend Test). The success of the approach using the PreCR™ repair enzymes was sporadic; it led to allele restoration as well as allele drop-out. Additionally, allele restoration with the PreCR™ enzymes was compared with restoration by alternative, but commonly implemented approaches using Restorase™, PCRBoost™, bovine serum albumin (BSA) and the Minifiler™ STR system. The alternative methods were also successful in improving the STR profile, but their success also depended on the quality of the template encountered. Our results indicate the PreCR™ repair kit may be useful for restoring STR profiles from damaged DNA, but further work is required to develop a generalized approach.     

Cell-free collagen type I matrix for repair of cartilage defects—clinical and magnetic resonance imaging results

Purpose

Several well-described techniques are available for the treatment of chondral and osteochondral defects. The aim of the study was to assess the efficacy of a single-stage procedure incorporating a new cell-free collagen type I gel for the treatment of small chondral and osteochondral defects in the knee evaluated at 2-year follow-up.

Methods

Fifteen patients were treated with a cell-free collagen type I gel matrix of 11?mm diameter. The grafts were implanted in the debrided cartilage defect and fixed by press-fit only. The clinical outcome was assessed preoperatively and at 6?weeks, and 6, 12 and 24?months after surgery using the International Knee Documentation Committee (IKDC) score, Tegner activity scale and visual analogue scale (VAS). Graft attachment rate was assessed 6?weeks postoperatively using magnetic resonance imaging (MRI). Cartilage regeneration was evaluated using the Magnetic Observation of Cartilage Repair Tissue (MOCART) score at 6, 12 and 24?months after implantation. Clinical results were correlated with MRI findings.

Results

Six male and nine female patients were included in this study, with a mean age of 26 (range: 19–40). No complications were reported. The mean VAS values after 6?weeks and the mean IKDC patient values after 6?months were significantly improved from the preoperative values (P?=?0.005 and P?=?0.009, respectively). This improvement remained up to the latest follow-up. There were no significant differences between the median preoperative and postoperative Tegner values (n.s.). Significant improvement of the mean MOCART score was observed after 12?months and remained by 24?months (P?Conclusions The present study reveals that the new method produces both good clinical and magnetic resonance imaging results. Use of press-fit only implanted grafts of a smaller diameter leads to a high attachment rate at 24-month follow-up.

Level of evidence

IV.     

T(1ρ) and T(2) quantitative magnetic resonance imaging analysis of cartilage regeneration following microfracture and mosaicplasty cartilage resurfacing procedures

Purpose

To examine T_1ρ (T1rho) and T₂ quantitative magnetic resonance imaging (MRI) in evaluating cartilage regeneration following microfracture (MFx) and mosaicplasty (MOS) cartilage resurfacing procedures.

Materials and Methods

Eighteen patients underwent MFx and eight patients underwent MOS to treat symptomatic focal cartilage defects. Quantitative T_1ρ and T₂ maps were acquired at 3–6 months and 1 year after surgery. The area of resurfacing was identified, and T_1ρ and T₂ values for the regenerated tissue (RT) and normal cartilage (NC) were acquired. RT/NC ratios were calculated to standardize absolute T_1ρ and T₂ values. Data were prospective, cross‐sectional, and nonrandomized.

Results

T_1ρ and T₂ showed good reanalysis reproducibility for RT and NC. Significant differences between RT and NC were present following MFx at 3–6 months for T_1ρ and T₂ values as well as following MOS at 3–6 months and 1 year for T_1ρ values. Following MFx, the T₂ RT/NC ratio was significantly different between 3–6 months and 1 year (P = 0.02), while the T_1ρ RT/NC ratio approached significance (P = 0.07). Following MOS, the T_1ρ and T₂ RT/NC ratios were not significantly different between the two timepoints.

Conclusion

T_1ρ and T₂ MRI are complementary and reproducible methods for quantitatively and noninvasively monitoring regeneration of RT following MFx and MOS. J. Magn. Reson. Imaging 2010;32:914–923. © 2010 Wiley‐Liss, Inc.     

Human cartilage fragments in a composite scaffold for single-stage cartilage repair: an in vitro study of the chondrocyte migration and the influence of TGF-β1 and G-CSF

Purpose

Minced chondral fragments are becoming popular as a source of cells for cartilage repair, as a growing interest is developing towards one-stage procedures to treat cartilage lesions. The purpose of this study is to (A) compare cell outgrowth from cartilage fragments of adult and young donors using two different types of scaffolds and (B) evaluate the influence of transforming-growth-factor-β1 (TGF-β1) and granulocyte colony-stimulating factor (G-CSF) on chondrocyte behaviour.

Methods

In part (A) cartilage fragments from adult and young donors were either loaded onto an HA-derivative injectable paste scaffold or onto an HA-derivative membrane scaffold. Construct sections were then examined for cell counting after 1, 2 and 3 months. In part (B) only membrane scaffolds were prepared using cartilage fragments from young donors. Constructs were cultured either in standard growth medium or in the presence of specific growth factors, such as TGF-β1 or G-CSF or TGF-β1 + G-CSF. After 1 month, construct sections were examined for cell counting. Expression of chondrocyte markers (SOX9, CD151, CD49c) and proliferative markers (β-catenin, PCNA) was assessed using immunofluorescence techniques, both in unstimulated construct sections and in cells from unstimulated and stimulated construct cultures.

Results

Part (A): histological analysis showed age-dependent and time-dependent chondrocyte migration. A significant difference (p < 0.05) was observed between young and older donors at the same time point. No difference was detected between the two types of scaffolds within the same group at the same time point. Part (B): after 1 month, the number of migrating cells/area significantly increased due to exposure to TGF-β1 and/or G-CSF (p < 0.05). Immunofluorescence revealed that outgrowing cells from unstimulated scaffold sections were positive for SOX9, CD151, CD49c and G-CSF receptor. Immunofluorescence of cells from construct cultures showed an increase in β-catenin in all stimulated groups and an increased PCNA expression in G-CSF-exposed cultures (p < 0.05).

Conclusion

Outgrowing cells may represent a subset of chondrocytes undergoing a phenotypic shift towards a proliferative state. TGF-β1, and to a greater extent G-CSF, may accelerate this outgrowth. The clinical relevance of this study may involve a potential future clinical application of scaffolds preloaded with growth factors as an additional coating for chondral fragments. Indeed, a controlled delivery of G-CSF, widely employed in various clinical settings, might improve the repair process driven by minced human cartilage fragments during one-stage cartilage repair.     

Evaluation of the Precision ID Identity Panel for the Ion Torrent™ PGM™ sequencer

In cases where only a partial or incomplete STR profile is obtained from a sample, information contained in single nucleotide polymorphisms (SNPs) can prove informative for human identification. Thermo Fisher Scientific, which developed the high throughput Ion Torrent^™ PGM^™ sequencer, released the Precision ID Identity Panel, a multiplex SNP panel for human identity. We evaluated the reproducibility and sensitivity of this multiplex, which contains primers for the amplification of 90 autosomal SNPs and 34 Y-clade SNPs. The manufacturer’s protocol was tested using five commercially available pure native DNAs and six forensic type samples at a range of DNA input amounts (0.2–1.0 ng; n, 90). In addition to analyzing the data using the manufacturer’s software, HID SNP Genotyper (v4.3.1), we also used CLC Genomics Workbench (Qiagen). Although library yields and templating of ion sphere particles (ISPs) were low, downstream sequencing was still successful. Across all samples, only 1.5% of all possible quality control (QC) flags were raised by both the plugin QC filter and CLC; 85% of those flags were raised as the SNP had a major allele frequency outside the thresholds specified by the manufacturer. For the remaining SNPs, coverage of >1500 X and >780 X was obtained for autosomal and Y-clade SNPs respectively, and 100% congruence among genotype calls from both analysis programs was observed. Our results demonstrate that it is possible to obtain reliable and reproducible genotypes using the Precision ID Identity Panel, when using low quantities (≥0.2 ng) of either pure native DNA or forensic type DNA samples.     

Endovascular abdominal aortic aneurysm repair: how many patients are eligible for endovascular repair?

PURPOSE: The purpose of this study was to determine how many patients with abdominal aortic aneurysm (AAA) are eligible for endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: We retrospectively reviewed computed tomography (CT) angiograms obtained between January 2002 and June 2003 in 182 patients with suspected AAA. Indication for surgical or endovascular treatment was based on clinical and radiological criteria. The percentage of patients eligible for EVAR was evaluated. RESULTS: Out of a total of 182 patients with suspected AAA studied by CT angiography, after combined radiological-surgical assessment, 130 were considered eligible for surgical or endovascular treatment (71.4%). EVAR was indicated in 51 patients (39.3%, group A) and surgical repair was indicated in 79 patients (60.7%, group B). The reasons for ineligibility for EVAR were the following: unfavourable anatomy of the proximal neck in 41 patients (51.9%), diameter of the aneurysm sac >7 cm in 13 patients (16.4%), markedly tortuous/dilated iliac axis in six patients (7.6%), age <65 years in 17 patients (21.5%) and patient refusal in two cases (2.5%). There were no statistically significant differences in aneurysm diameter (52.7+/-0.8 versus 49.8+/-1.2 mm, p=ns), patients' age (73.2+/-1.2 versus 70.6+/-2.02 years, p=ns) or proximal neck length (2.95+/-1 versus 3.03+/-1.2 cm, p=ns) between groups A and B. CONCLUSIONS: Endovascular repair of abdominal aortic aneurysms through the placement of aortic stent-grafts has now become a viable alternative to open surgery. In recent years, the number of patients treated with EVAR has steadily risen as a result of increased physician experience, availability of new and more versatile devices and improvements in noninvasive imaging techniques. Unfavourable neck anatomy is the primary factor for exclusion from endovascular repair.     

Cell-free repair of small cartilage defects in the Goettinger minipig: which defect size is possible?

Purpose

Cartilage repair of full-thickness chondral defects in the knees of Goettinger minipigs was assessed by treatment with cell-free collagen type-I gel plugs of three different sizes.

Methods

In 6 adult Goettinger minipigs, three full-thickness chondral defects were created in the trochlear groove of one knee of the hind leg. These defects were treated with a cell-free collagen type-I gel plug of 8, 10, or 12 mm diameter. All animals were allowed unlimited weight bearing. After 1 year, the animals were killed. Immediately after recovery, a non-destructive biomechanical testing was performed. The repair tissue quality was evaluated immunohistologically, collagen type-II protein was quantified, and a semiquantitative score (O’Driscoll score) was calculated.

Results

After 1 year, a high number of cells migrated into the initially cell-free collagen gel plugs and a hyaline-like repair tissue had been created. The O’Driscoll scores were: 8 mm, 21.2 (SD, 2.8); 10 mm, 21.5 (SD, 1.6); and 12 mm, 22.3 (SD, 1.0). The determination of the e-modulus, creep and relaxation revealed that mechanical properties of the two smaller defects were closer to unaffected hyaline cartilage.

Conclusions

As cell-free collagen type-I gel plugs of all three different sizes created hyaline-like repair tissue, this system seems suitable for the treatment of even larger defects.     

Uptake of 99mTc-labeled chondroitin sulfate by chondrocytes and cartilage: a promising agent for imaging of cartilage degeneration?

Chondroitin sulfate (CS) is used in the treatment of human osteoarthritis as a slow-acting symptomatic drug. For this reason, we performed uptake studies with ^99mTcCS using different chondrocyte cultures, as well as cartilage tissue in vitro.For uptake studies, adherent monolayer cultures of human chondrocytes (2.7×10⁴ cells/well) and ^99mTcCS (1 μCi) were used. In parallel, we also performed uptake studies with cell suspensions of human chondrocytes at 1×10⁶ cells/well incubated with ^99mTcCS (5 μCi) under identical conditions. Uptake was studied also in cartilage tissue samples and frozen tissue sections for autoradiography. The uptake was monitored for 10–240 min, every 10–30 min for cell cultures and for cartilage tissue up to 72 h. As the commercially available drug Condrosulf (IBSA, Lugano, Switzerland) contains magnesium (Mg) stearate as additive, we investigated the uptake with and without this additive. The washout of the tracer was assessed after the uptake experiments with PBS buffer for different time intervals (10 min–3 h).Tracer uptake in monolayer±additives with low number of cells was low. With the use of chondrocytes in culture suspensions with higher number of cells, a higher uptake of 5.9±0.65% and 1.0±0.1% (n=6) was found, with and without additive, respectively. The saturation was achieved after 100 min. With the use of human rib cartilage, the uptake of ^99mTcCS was continuously increasing with time and was very high with additive amounting to 101.8±5.2% vs. 53.0±8.3% (n=6) without after 72 h and showing delayed saturation up to 30 h. Thus, not only the resorption of the drug is enhanced by Mg-stearate, but also the uptake. The washout of the tracer from cartilage after 3 h of uptake amounted to 3.75±1.5% with additive vs. 13.1±2.1% without. After 24 h, washout was lower amounting to 1.75±0.15% vs. 3.25±0.25%, respectively. The autoradiographic studies paralleled the results of in vitro cartilage tissue uptake.These data show that ^99mTcCS accumulates in cartilage tissue, either by acting as a substrate for proteoglycan synthesis or by adsorption to cartilage. ^99mTcCS could therefore be a possible agent to target and radioimage osteoarthritis.     

Platelet-rich plasma activation in combination with biphasic osteochondral scaffolds–conditions for maximal growth factor production

Purpose  

The combination of scaffolds and biological factors may enhance articular cartilage repair. Little is known regarding the activation and subsequent growth factor release of platelet-rich plasma (PRP) in contact with biosynthetic scaffolds. The purpose of this study was i) to identify whether the addition of thrombin was required to activate PRP in the presence of a collagen osteochondral scaffold and ii) to compare the activity of PRP when applied to both collagen- and polylactide-based osteochondral scaffolds.     

Autologous whole blood or corticosteroid injections for the treatment of epicondylopathy and plantar fasciopathy? A systematic review and meta-analysis of randomized controlled trials

ObjectivesTo compare the efficacy of autologous whole blood with that of corticosteroid injections on epicondylopathy and plantar fasciopathy.DesignSystematic review and meta-analysis.MethodsThe databases of PubMed, Web of Science, CENTRAL, and Scopus were searched up to 6th May 2015. Randomized trials comparing the effects of autologous whole blood and corticosteroid injections on epicondylopathy or plantar fasciopathy were included. Trials exploring the efficacy of platelet-rich plasma were excluded. The primary outcome was pain relief. The secondary outcome included the assessment of composite outcomes. All outcomes were assessed at 2–6 (short-term) weeks, 8–13 (intermediate-term) weeks and 24–26 (medium-term) weeks. Quality assessment was performed with the Cochrane risk of bias tool.ResultsNine trials were included. For pain relief, there was a statistically significant difference in favour of corticosteroids in the short term (SMD 0.52; 95%CIs 0.18 to 0.86; I² = 53%; p < 0.01). A statistically significant difference in favour of autologous whole blood was indicated in the medium-term assessment of pain relief on epicondylopathy.ConclusionsCorticosteroids were marginally superior to autologous whole blood in relieving pain on plantar fasciopathy at 2–6 weeks. Autologous whole blood provided significant clinical relief on epicondylopathy at 8–24 weeks. Conclusions were limited by the risk of bias.