Higher Accuracy of Arthroscopy Compared to MRI in the Diagnosis of Chondral Lesions in Acute Ankle Fractures: A Prospective Study.

Even after successful surgery for acute ankle fractures, many patients continue having complaints. A possible explanation is the presence of concomitant chondral lesions. The aim of this study is to investigate the accuracy of MRI compared to that of arthroscopy in the assessment of chondral lesions in acute ankle fractures. In this prospective single-center study, patients presenting with acute ankle fractures over a period of three years were identified. A preoperative MRI was performed within a maximum of 10 days after trauma. During surgery, ankle arthroscopy was also performed. The International Cartilage Repair Society (ICRS) cartilage lesion classification was used to grade the detected chondral lesions. To localize the chondral lesions, the talar dome was divided into eight zones and the tibial/fibular articular surfaces into three zones. In total, 65 patients (28 females) with a mean age of 41.1 ± 15 years were included. In the MRI scans, 70 chondral lesions were detected (69.2% of patients) affecting mostly the tibial plafond (30%) and mostly graded as ICRS 3. The mean lesion area measured was 20.8 mm2. In the arthroscopy, 85 chondral lesions were detected (70.8% of patients) affecting mostly the medial surface of the talar dome (25.9%) and mostly graded ICRS 3. The mean lesion area measured was 43.4 mm2. The highest agreement between the two methods was observed in the size estimation of the chondral lesions. The present study shows the reduced accuracy of MRI when compared to arthroscopy in the assessment of traumatic chondral lesions in the setting of acute ankle fractures especially regarding lesion size. MRI remains an essential instrument in the evaluation of such lesions; however, surgeons should take this discrepancy into consideration, particularly the underestimation of chondral lesions' size in the preoperative planning of surgical treatment and operative technique.

Save the subchondral bone plate: Debridement versus bone marrow stimulation in acetabular cartilage defects over 60 months of follow-up.

PURPOSE: Bone marrow stimulation is a common treatment for full-thickness cartilage defects in the hip joint. However, common procedures may result in poor fibrous repair tissue and changes to the subchondral anatomy. This study investigated the clinical outcome of a cohort of International Cartilage Repair Society (ICRS) grades 3 and 4 cartilage defects treated with bone marrow stimulation compared to those who received simple debridement/chondroplasty. METHODS: In this retrospective registry study, 236 patients with uni-focal acetabular chondral lesions of the hip up to 400 mm² (mean 177.4 ± 113.4 mm²) and of ICRS grade ≥3 with follow-up of at least 12 months (mean 33.2 ± 15.3 months) were included. Eighty-one patients underwent bone marrow stimulation (microfracture: n = 44, abrasion: n = 37) besides treatment of the underlying pathology, 155 patients underwent defect debridement/chondroplasty. The patient-reported outcome was measured using the International Hip Outcome Tool 33 (iHOT33) score and the Visual Analogue Scale (VAS) for pain. RESULTS: iHOT33 and VAS both improved highly statistically significantly (p < 0.001) in the debridement group after 6, 12, 24, 36 and 60 months compared to the preoperative scores, whereas iHOT33 and VAS after microfracture or abrasion did not show statistically significant changes over time. Twenty-four and sixty months postsurgery the debridement group revealed significant higher scores in the iHOT33 compared to the bone marrow stimulation groups. CONCLUSION: Patients with chondral lesions of the hip ≤400 mm2 sustainably benefit from arthroscopic debridement under preservation of the subchondral bone plate in terms of functional outcome and pain in contrast to patients treated with bone marrow stimulation. These findings discourage the currently recommended use of microfracture in the hip joint. LEVEL OF EVIDENCE: Level III.

Patients with Small Acetabular Cartilage Defects Caused by Femoroacetabular Impingement Do Not Benefit from Microfracture.

OBJECTIVE: According to current recommendations, large cartilage defects of the hip over 2 cm2 are suggested to undergo autologous chondrocyte transplantation (ACT), while small defects should be treated with microfracture. We investigated if patients with small chondral defects of the hip joint (≤100 mm2) actually benefit from microfracture. DESIGN: In this retrospective multicenter cohort study 40 patients with focal acetabular cartilage defects smaller than 100 mm2 and of ICRS grade ≥2 caused by femoroacetabular impingement were included. Twenty-six unrandomized patients underwent microfracture besides treatment of the underlying pathology; in 14 patients cartilage lesions were left untreated during arthroscopy. Over a mean follow-up of 28.8 months patient-reported outcome was determined using the iHOT33 (international hip outcome tool) and the VAS (visual analog scale) for pain. RESULTS: The untreated group showed a statistically significant improvement of the iHOT33 after 12 (p = 0.005), 24 (p = 0.019), and 36 months (p = 0.002) compared to the preoperative score, whereas iHOT33 in the microfracture group did not reveal statistically significant changes over time. There was no significant difference between both groups on any time point. Regarding pain both groups did not show a significant improvement over time in the VAS. CONCLUSION: The subjective outcome of patients with small cartilage defects of the hip (≤100 mm2) improves 12 months after arthroscopic FAIS surgery without any cartilage treatment. However, no improvement could be seen after microfracture. Therefore, a reserved surgical treatment for small cartilage defects of the hip under preservation of the subchondral bone is recommended especially if a simultaneous impingement correction is performed.

Report on a large animal study with Göttingen Minipigs where regenerates and controls for articular cartilage were created in a large number. Focus on the conditions of the operated stifle joints and suggestions for standardized procedures.

The characterization of regenerated articular cartilage (AC) can be based on various methods, as there is an unambiguous accepted criterion neither for the natural cartilage tissue nor for regenerates. Biomechanical aspects should be considered as well, leading to the need for more equivalent samples. The aim of the study was to describe a large animal model where 8 specimens of regenerated AC can be created in one animal plus the impact of two surgeries on the welfare of the animals. The usefulness of the inclusion of a group of untreated animals (NAT) was to analyzed. Based on the histological results the conditions of the regenerates were to be described and the impact on knee joints were to be explored in terms of degenerative changes of the cartilage. The usefulness of the statistical term "effect size" (ES) will be explained with histological results. We analyzed an animal model where 8 AC regenerates were obtained from one Göttingen Minipig, on both sides of the trochleae. 60 animals were divided into 6 groups of 10 each, where the partial thickness defects in the trochlea were filled with matrices made of Collagen I with or without autologous chondrocytes or left empty over the healing periods of 24 and 48 weeks. One additional control group consisting of 10 untreated animals was used to provide untouched "external" cartilage. We harvested 560 samples of regenerated tissue and "external" controls, besides that, twice the number of further samples from other parts of the joints referred to as "internal" controls were also harvested. The animals recovered faster after the 1st operation when the defects were set compared to the 2nd operation when the defects were treated. 9% of all animals were lost. Other complications were for example superficial infections, seroma, diarrhea, febrile state and an injury of a claw. The histological results of the treatments proved the robustness of the study design where we included an "external" control group (NAT) in which the animals were not operated. Comparable significant differences between treated groups and the NAT group were detected both after ½ year and after 1 year. Spontaneous regenerated AC as control revealed differences after an observation time of nearly 1 year. The impact of the treatment on cartilage adjacent to the defect as well as the remaining knee joint was low. The ES was helpful for planning the study as it is shown that the power of a statistical comparison seems to be more influenced by the ES than by the sample size. The ranking of the ES was done exemplarily, listing the results according to their magnitude, thus making the results comparable. We were able to follow the 3 R requirements also in terms of a numerical reduction of animals due to the introduction of a group of untreated animals. This makes the model cost effective. The presented study may contribute as an improvement of the standardization of large animal models for research and regulatory requirements for regenerative therapies of AC.

[Influence of Synovial Fluid on Lubrication of Articular Cartilage in Vitro - A Review]. / Einfluss der Synovialflüssigkeit auf die Schmiereigenschaften von Gelenkknorpel in vitro.

Articular cartilage possesses unique tribological properties that are essential to reduce friction and wear. Especially under boundary lubrication conditions, synovial fluid as a whole, and its components ("biolubricants"), are important in assuring near frictionless/contactless lubrication of the joint surfaces. Therefore, several in vitro tribological models have been developed in recent years to investigate possible interdependencies. The aim of this article is to give a cursory overview of the influence of synovial fluid and its components on boundary lubrication of articular cartilage surfaces in vitro.

Feasibility of arthroscopic autologous chondrocyte implantation in the hip using an injectable hydrogel.

INTRODUCTION: In the long term the treatment of articular cartilage defects of the hip has the most direct impact on the postoperative outcome and should diminish degenerative changes caused by different pathologies. The purpose of this prospective feasibility study is to describe technical aspects of arthroscopic, injectable autologous chondrocyte implantation in the hip and to report the short-term outcome. METHODS: Full-thickness cartilage defects of 13 patients were treated arthroscopically with an injectable autologous chondrocyte transplantation product (Novocart Inject, Tetec) in a 2-step surgical procedure. Patient-related outcome was assessed with iHOT 33, EQ-5D and Non Arthritic Hip Score at baseline (day before transplantation), after 6 weeks and 3, 6 and 12 months. RESULTS: 13 out of 13 patients (all men) with a mean age of 32.7 ± 6.9 years and an average defect size of 1.9 ± 1.0 cm2 were available for follow-up after a mean of 12 months (range 6-24 months). All defects were located on the acetabulum and 11 were associated with a labral lesion of 2.9 hours size. Femoroacetabular impingement (10 cam, 2 combined, 1 pincer) was the cause of all defects. An overall statistically significant improvement was observed for all assessment scores. CONCLUSIONS: In this study we present the feasibility and short-term data of an arthroscopic injectable autologous chondrocyte transplant as a treatment option for full-thickness cartilage defects of the hip. All patient-administered assessment scores demonstrated an increase in activity level, improvement in quality of life and reduction of pain after a 12-month follow-up. Further randomised controlled trails with long-term follow-up and additional morphological assessment are needed.

Arthroscopic autologous chondrocyte implantation in the hip for the treatment of full-thickness cartilage defects - A case series of 29 patients and review of the literature.

PURPOSE: Current literature indicates that the appropriate treatment of articular cartilage defects has significant influence on the postoperative outcome after hip arthroscopy. In the hip, arthroscopic treatment of cartilage defects is technically challenging, especially the autologous chondrocyte implantation/matrix-associated autologous chondrocyte implantation (ACI/MACI) procedures. The purpose of this prospective study was to introduce two injectable MACI products with self-adherent properties. Furthermore, we report short-term outcome and review the current literature. METHODS: Full-thickness cartilage defects of 29 patients caused by the femoroacetabular impingement (FAI) were treated arthroscopically with an injectable MACI product in a two-step surgical procedure. The patient-related outcome was assessed with International Hip Outcome Tool (iHOT33), Euro-Quol group score (EQ-5D) and Non-Arthritic-Hip-Score (NAHS) at baseline, six weeks, six, 12 and 24 months. RESULTS: Twenty-nine out of 46 patients (27 male/two female) with a mean age of 30.3 years (range 18-45 years) and an average defect size of 2.21 cm2 were available for follow-up after a mean of 19 months (range 6-24 months). All defects were located on the acetabulum International Cartilage Repair Society (ICRS) grade 3A-3D (nine 3A; eleven 3B; six 3C; three 3D). Twenty-six patients had associated labral pathology (23 repair 1-5 anchors; three partial trimming). Twenty-seven defects were caused by the FAI (20 CAM, six combined, one Pincer), two cases were of traumatic cause. An overall statistically significant improvement was observed for all assessment scores at an average follow-up of 19 months. CONCLUSION: In this study, we present short-term data of new arthroscopic injectable matrix-associated, autologous chondrocyte implants as a treatment option for full-thickness cartilage defects of the hip. All patient-administered assessment scores demonstrated an increase in activity level, quality of life and reduction of pain after a 19-month follow-up. Further randomized controlled trails (RCTs) with comparison of natural history, bone marrow stimulation techniques and MACI of the hip have to approve the results in long-term follow-up.

Prevalence of Cam and Pincer Deformities in the X-Rays of Asymptomatic Individuals.

OBJECTIVE: The presence of radiological signs of femoroacetabular impingement (FAI) is not necessarily associated with symptoms. Hence, the prevalence of cam and pincer deformities in the overall population may be underestimated. The purpose of this study was to screen an unselected cohort of people without hip symptoms for native radiological signs of cam and pincer deformities to determine their actual prevalence. MATERIALS AND METHODS: 110 asymptomatic patients had AP pelvis X-rays and cross-table hip X-rays performed. We evaluated the images for the presence of cross-over signs and measured lateral center edge (LCE) angles, alpha angles (α-angles), and femoral offset ratios. RESULTS: Positive cross-over signs were seen in 34%; LCE angles > 40° in 13%; and femoral offset ratios < 0.18 in 43%. In 41% of the patients, α-angles were >50°. Male patients showed significantly higher α-angles, lower offset ratios, and a higher prevalence of cross-over signs. In contrast, female patients had significantly higher LCE angles. CONCLUSION: According to our data, radiological signs of cam and pincer deformities are common in asymptomatic people. In clinical practice, patients presenting with hip pain and radiological signs of FAI should undergo further diagnostic evaluation. However, in asymptomatic patients, no further evaluation is recommended.

Acellular dermal matrix seeded with autologous fibroblasts improves wound breaking strength in a rodent soft tissue damage model in neoadjuvant settings.

Soft tissue defects following resectional surgery or trauma often result in deadspaces and require free or pedicled flaps. A programmed formation of filling tissue with enhanced biomechanical properties could be helpful. This study examined the effects on wound healing of acellular dermal matrix (ADM) seeded with autologous fibroblasts in a standardized rodent model. As pre- or postoperative radiotherapy is standard in many treatments of malignancies, we also investigated the effects of additional radiotherapy. Fischer rats were randomised and received a standardized unilateral soft tissue defect at the buttock. The defect was filled with ADM+fibroblasts or ADM alone. Controls received no filling. Either no radiation, adjuvant (postoperative) or neoadjuvant (preoperative) radiation was applied to the defect site. Six weeks later the defect volume was measured by MR-tomography. Wound breaking strength was examined by tensiometry according to German Industrial Standards. Filling of the defect side was significantly larger in ADM and ADM+fibroblast treated groups compared to the control group in all settings. Wound breaking strength in the unimodal setting was significantly improved in the ADM+fibroblasts group compared to the ADM group. In the neoadjuvant setting there was no significant difference between control and ADM group. However, the ADM+fibroblasts groups showed a significantly increased wound breaking strength compared to the control and the ADM-alone group. Seeded or unseeded ADM is able to fill deadspace in this rodent model in all settings. Implanting non-irradiated, vital, proliferating autologous fibroblasts on ADM results in significantly increased wound breaking strength.