[Relevance of meniscus loss for the progression of osteoarthritis and treatment options for early arthritis]. / Relevanz des Meniskusverlustes für die Arthroseprogression und Therapieoption bei bereits bestehender Früharthrose.

Meniscal tears are still one of the most frequent lesions in the knee joint. The relevance of meniscus loss for the development of osteoarthritis is undisputed. Meniscus repair, replacement and transplantation play an important role in the treatment of early arthritis, especially when they are a part of a master plan including alignment correction, stabilization and cartilage surgery, if needed. Scientific data show evidence concerning the protection of osteoarthritis, even though a lack of studies including comparison groups has to be admitted.

Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: A guideline by the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU).

BACKGROUND: Autologous chondrocyte implantation (ACI) is an established and well-accepted procedure for the treatment of localised full-thickness cartilage defects of the knee. METHODS: The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning therapeutic consequences of primary cartilage lesions and the suitable indication for ACI. RESULTS: Based on best available scientific evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than three to four square centimetres; in the case of young and active sports patients at 2.5cm(2), while advanced degenerative joint disease needs to be considered as the most important contraindication. CONCLUSION: The present review gives a concise overview on important scientific background and the results of clinical studies and discusses the advantages and disadvantages of ACI. LEVEL OF EVIDENCE: Non-systematic Review.

[Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: a guideline by the working group "Tissue Regeneration" of the German Society of Orthopaedic Surgery and Traumatology (DGOU)]. / Stellenwert der autologen Chondrozytentransplantation (ACT) in der Behandlung von Knorpelschäden des Kniegelenks - Empfehlungen der AG Klinische Geweberegeneration der DGOU.

Autologous chondrocyte transplantation/implantation (ACT/ACI) is an established and recognised procedure for the treatment of localised full-thickness cartilage defects of the knee. The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning potential consequences of primary cartilage lesions and the suitable indication for ACI. Based on current evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than 3-4 cm2; in the case of young and active sports patients at 2.5 cm2. Advanced degenerative joint disease is the single most important contraindication. The review gives a concise overview on important scientific background, the results of clinical studies and discusses advantages and disadvantages of ACI.

Hypoxia reduces the inhibitory effect of IL-1beta on chondrogenic differentiation of FCS-free expanded MSC.

OBJECTIVE: Mesenchymal stromal cells (MSC) are a promising tool for tissue engineering of the intervertebral disc (ID). The IDs are characterized by hypoxia and, after degeneration, by an inflammatory environment as well. We therefore investigated the effects of inflammation induced with interleukin (IL)-1beta and of hypoxia (2% O(2)) on the chondrogenic differentiation of MSC. METHODS: Bone-marrow-derived MSC (bmMSC) were cultured in a fetal-calf-serum-free medium and characterized according to the minimal criteria for multipotent MSC. Chondrogenic differentiation of MSC was induced following standard protocols, under hypoxic conditions, with or without IL-1beta supplementation. After 28 days of differentiation, micromasses were analyzed by histochemical staining and immunohistochemistry and by determining the mRNA level of chondrogenic marker genes utilizing quantitative RT-PCR. RESULTS: Micromasses differentiated under IL-1beta supplementation are smaller and express less extracellular matrix (ECM) protein. Micromasses differentiated under hypoxia appear larger in size, display a denser ECM and express marker genes comparable to controls. The combination of hypoxia and IL-1beta supplementation improved chondrogenesis compared to IL-1beta supplementation alone. Micromasses differentiated under standard conditions served as controls. CONCLUSION: Inflammatory processes inhibit the chondrogenic differentiation of MSC. This may lessen the regenerative potential of MSC in situ. Thus, for the cell therapy of IDs using MSC to be effective it will be necessary to manage the inflammatory conditions in situ. In contrast, hypoxic conditions exert beneficial effects on chondrogenesis and phenotype stability of transplanted MSC, and may improve the quality of the generated ECM.

3-Dimensional ultrasound imaging for meniscal lesions.

PURPOSE: The aim of this prospective study was to evaluate preoperative three-dimensional ultrasound scans for the detection of meniscal lesions with a special focus on interobserver reliability. METHODS: Forty one patients with clinical signs of meniscal lesions were preoperatively examined by ultrasound using the 3-D technique (11.7 MHz linear transducer). The 3-D dataset was stored and examined by a second orthopaedic surgeon. The second ultrasound examiner was blinded to the results of the first. Any meniscal pathology was confirmed arthroscopically and documented. RESULTS: At arthroscopy eight lateral meniscal lesions and 57 medial meniscal lesions were detected at different locations. The sensitivity and specificity of the original ultrasound examination was acceptable whereas the results of the second ultrasound session were not as sensitive. CONCLUSION: Three-D-ultrasound with a high resolution transducer, in the hands of an experienced operator, provides acceptable results in the detection of meniscal lesions, however, analysis of the volume dataset from the 3-D ultrasound investigation indicates that it does not offer sufficient accuracy for clinical use.

[Treatment of osteochondritis dissecans of the knee: one-step procedure with bone grafting and matrix-supported autologous chondrocyte transplantation]. / Einzeitige Rekonstruktion osteochondraler Defekte am Kniegelenk bei Osteochondrosis dissecans.

AIM: The aim of this study was to establish and assess a one-step reconstruction procedure of deep osteochondral defects of the knee joint with bone grafting and matrix-supported autologous chondrocyte transplantation in osteochondritis dissecans. METHOD: Between 2004 and 200622 patients with osteochondral defects in the weight-bearing zone of the femoral condyles(ICRS OCD III and IV) were reconstructed simultaneously with bone grafting and matrix-supported autologous chondrocyte transplantation (NOVOCART 3D). All patients were analysed prospectively. RESULTS: 17 Males and 5 females(age 28.3, range: 17-49 years) were surgically treated with the above-mentioned novel method. Before reconstruction osteochondral defects had an average defect area of 4.8 (2.4-9.0) cm2 and a depth of between 4 and 15 mm. For reconstruction an average of 2.6 (1-6) monocortical cancellous bone cylinders (diameter 8mm) was used to fill the osseous defect and to reconstruct the subchondral bone plate with adequate positioning of the monocortical layer of the graft. Then a Matrix-ACT was used to cover the reconstructed subchondral bone plate. The average follow-up was 16 (6-36) months. The average Tegner activity score was 4 (3-7) of 10. The Lysholm-Gillquistscore and the Cincinnati Sports Medicine and Orthopedic Center score were significantly improved postoperatively. The IKDC-2000 questionnaire was also significantly increased by 50%. CONCLUSION: The simultaneous reconstruction of deep osteochondral detects of the knee joint with bone grafting and matrix-supported autologous chondrocyte transplantation in osteochondritis dissecans is a biological, one-step alternative to previously reported methods with encouraging first results.

[Cartilage repair in the knee joint]. / Biologische Knorpelrekonstruktion im Kniegelenk.

Full thickness defects of the articular cartilage in the knee joint have lower regenerative properties compared to chondral lesions of the ankle. In order to avoid early osteoarthritis, symptomatic articular cartilage defects in younger patients should undergo biological reconstruction as early as possible. There are different surgical procedures available to achieve a biological resurfacing of the articular joint line. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to a conservative or delayed operative treatment. This effect refers not only to the defect healing but also to the elimination of changes following secondary osteoarthritis. The different surgical procedures can be differentiated concerning the various indications and the final outcome. Additional malalignment, meniscus tears, and/or ligament instabilities should be treated simultaneously together with the cartilage resurfacing. The mid- and long-term results of the different current techniques are promising, but further modifications and improvements are needed.

[Value of three-dimensional ultrasound and MRI in meniscal lesions]. / Wertigkeit von 3D-Sonographie und MRT des Meniskusschadens.

BACKGROUND: The aim of this prospective study was the evaluation of preoperative three-dimensional ultrasound in detecting meniscal lesions compared to preoperative MRI. METHODS: A total of 34 patients with clinical signs of meniscal lesions were examined preoperatively (11.7 MHz linear transducer) using the 3-D technique. Before ultrasound, MRI was performed, the results of which were unknown to the ultrasound examiner. The basis of the MRI result was the radiologist's written report. Arthroscopically the meniscal situation was noted and taken as reference. RESULTS: At arthroscopy there were 10 lateral meniscal lesions at different locations and 47 medial meniscal lesions at different locations. The sensitivity (0.5-0.78) and specificity (0.75-0.95) of both imaging methods were overall comparable. CONCLUSION: Ultrasound with the three-dimensional technique and high-resolution transducer in the hands of an experienced operator gives results comparable to the MRI interpretation by a general radiologist in detecting meniscal lesions.

[Significance and technique of autologous chondrocyte transplantation]. / Stellenwert und Technik der Autologen Chondrozyten-Transplantation.

The bad risk for an early onset of osteoarthritis in the knee increases with the size of a cartilage defect. A collateral meniscus- or ligament-tear will enforce this hazard in addition. In order to avoid such a development, relevant full-thickness cartilage defects should be reconstructed biologically and attendant meniscus- or ligament-tears as well as varus- or valgus deformities should be treated. A number of studies, including some prospective-randomized trials, have shown that autologous chondrocyte transplantation (ACT) is the most reliable procedure for a surgical treatment of full-thickness cartilage defects larger than 4 cm (2) in adults. One disadvantage of ACT is the extensive approach to the joint and often a hypertrophy of the repair tissue. To solve these problems, some different biomaterials for a matrix-assisted ACT have been developed. The scaffold we use has a covering membrane upside and a collagen-sponge carrying the chondrocytes. By means of special surgical instruments a minimally invasive implantation is possible, reducing the side-effects of an extensive approach. Animal studies showed the regeneration of a hyaline cartilage using our described system. However, results of current clinical studies with the different scaffolds must be awaited before an universal application of matrix-assisted ACT can be recommended.

[Distinctive features of the os naviculare pseudarthrosis vs the os naviculare accessorius]. / Unterscheidungsmerkmale der Os-naviculare-Pseudarthrose gegenüber dem Os naviculare accessorius.

We report on two cases in which the differential diagnosis between an os tibiale externum (os naviculare accessorius) and a post-traumatic pseudarthrosis of the os naviculare was subject to discussion.Both patients had suffered an acute trauma in the region of the middle foot and showed identical clinical symptoms. Conventional X-ray did not allow a definite classification of the diagnosis either.However, this was possible in both cases by virtue of typical signs evidenced by computed tomography and magnetic resonance imaging.

Rupture of the patellar tendon: a review of 68 cases and a retrospective study of 29 ruptures comparing two methods of augmentation.

Rupture of the patellar tendon is a rare injury requiring acute repair to reestablish knee extensor continuity and to allow early motion. Different pathomechanisms have been postulated, and multiple techniques for repair have been described in the literature. Firstly, the current study reviews the epidemiology, pathomechanism, and risk factors. Secondly, we compare the outcome of two augmentation techniques after end-to-end sutures: reinforcement with either a wire cerclage or a PDS cord. In the first part of the study, the medical records of 66 patients with 68 ruptures were reviewed. For the second part, 33 patients were included who had no prior injury to the extensor mechanism of the knee and had suffered an indirect, low-velocity injury followed by immediate repair. Twenty-seven patients with 29 ruptures of the patellar tendon returned for follow-up. Follow-up averaged 8.1 years (range 1-16 years). In the follow-up group, 22 ruptures had augmentation with a wire cerclage (group A), and 7 ruptures had augmentation with a 2-mm PDS cord (group B). Follow-up evaluation consisted of a subjective questionnaire, a physical and radiographic examination, the Hospital for Special Surgery Knee Score, and the Insall-Salvati ratio. Nineteen patients underwent Cybex isokinetic strength testing of the quadriceps. Indirect, low-velocity injuries occurred most often in the 30-40 year age group, whereas complex knee traumas or knee luxations were more evenly distributed. In 10 of 46 patients with an indirect, low-velocity injury, there was a history of prior injury and illness to the extensor mechanism of the knee, compared with 1 of 22 patients with a high-velocity complex knee trauma. In the follow-up group, no patient sustained a rerupture. Two of 22 patients had an extension lag in group A compared with no extension lag in group B. Average flexion in group A was 130 degrees (SD 29 degrees) compared with 137 degrees (SD 12 degrees ) in group B. The average Hospital for Special Surgery Knee Score was 92 (SD 17) in group A and 96 (SD 12) in group B. Three patients were dissatisfied. All had radiographic signs of retropatellar osteoarthritis. In contrast, 9 of 26 patients who were satisfied with their result had radiographic signs of retropatellar osteoarthritis. A postoperative difference in the Insall-Salvati ratio did not correlate with the development of osteoarthritis. Both augmentation techniques are reliable and demostrate good intermediate to long-term results. The outcome did not show significant differences. To avoid reoperation for removal of the cerclage wire, a PDS cord can be used. The infection rate seems to be higher in the PDS group. A larger prospective study group is necessary to determine whether this phenomenon can be reproduced.