Introduction: Meta-analyses are an important instrument in orthopaedic surgery, not only to create clinical guidelines, but also because their findings are included in public health and health policy decision-making. Generally, meta-analyses of randomised controlled trials are considered as the highest level of evidence. However, with increasing numbers of meta-analyses, discordance and frank conflicts in results have been seen, which might lead to grave complications considering the aforementioned facts. The purpose of this study was to search for conflicting meta-analyses in orthopaedic surgery, i.e. such arriving at different conclusions despite following the same research question; to identify potential reasons for, and to assess the actual amount and significance of such differences.

Methods: We searched the online databases PubMed, EMBASE and the Cochrane Controlled Trial Register for orthopaedic meta-analyses and cross-referenced results within and across databases to identify meta-analyses focusing on the same subject. Meta-analyses were defined as conflicting if they arrived at different results despite studying the same populations.

To assess the significance of such difference we used Cochrane’s Q-test. To test the amount, thus clinical meaning, of differences we calculated the I2-index, the amount of difference beyond random chance. Since both these parameters depend on study size, we also calculated the “uncertainty interval” (UI), which, in accordance to the 95% confidence interval contains the true I2-index of the whole population.

Results: We were able to identify conflicting meta-analyses on graft choice in ACL reconstruction (n=7), the use of hyaluronic acid (n=5) and pulsed electromagnetic fields in osteoarthritis (n=2). Significant differences could only be shown among meta-analyses on hyaluronic acid (p< 0.001). The uncertainty intervals were 38.6% to 78.6% for hyaluronic acid, 0% to 41.1% for ACL and 0% to 99% for electromagnetic fields in osteoarthritis.

Discussion: There are conflicting meta-analyses in orthopaedic research, posing a threat to evidence-based treatments. It seems, however, that a considerable amount of conflict derives from differences in the interpretation of pooled results rather than from the results themselves. In summary, findings and interpretations of meta-analyses should be as critically scrutinized as in any other type of study and subjected to re-assessment if deemed necessary.

Introduction: Minimally invasive surgery (MIS) in total joint replacement is a heavily if not fiercely discussed issue in orthopaedic surgery. Proponents of such techniques report faster healing and mobilization and strikingly satisfied patients, whilst critics warn of devastating complications. Although a large number of randomised, controlled trials and other studies have been published, the field is still characterized by inconsistent results. This study asked whether there is, in the entirety of the published literature, evidence in favor of or against the use of MIS techniques in total joint replacement.

Methods: We conducted a systematic review of ran-domised, controlled trials in the online databases PubMed, EMBASE, and the Cochrane Controlled Trial Register, as well as by hand-searching relevant publications. Subsequently, we pooled data for the effect of minimally invasive surgery (MIS) separately in individual meta-analyses per joint. 95% confidence intervals (CI) were constructed for the pooled estimates of the endpoints duration of procedure, estimated blood loss, perioperative complication rate, outliers in component placement, postoperative scores, hospital stay, and incision length. For these endpoints, the 95%CIs, which include the true population effect with 95% confidence, were compared for areas of overlap among different joints, which would indicate a common, independent effect of MIS techniques. The distance from zero and the spread of these overlaps are used to infer statistical significance.

Results: Data on 1161 patients in 12 trials were available. We found common effects for all endpoints, with average overlap of 62.4% and 50.5%, respectively. The common effects for component position, blood loss, postoperative scores, and incision length were significantly different from zero. Their absolute values were rather small at 20 mL to 70 mL less blood loss and a difference in effect size of 0.03 to 0.35 on clinical scores. There was no indication of a difference in complication rates.

Discussion: We could show that there is evidence that MIS total joint replacement is an effective alternative to other treatments. There is no evidence of higher complication rates among 1161 operations. Those results that were significantly better in the MIS group, however, had only small absolute values, suggesting MIS as an alternative but not substitute for classical methods. The question remains if these values are clinically significant or could be increased to sufficient numbers even techniques are developed further. For none of the endpoints we could see better result in the standard technique than with MIS.

Introduction: There is a general trend and even demand of using evidence-based methods in the practice of medicine. Especially in orthopedic surgery, which is a specialty traditionally employing treatments with obvious effectiveness, evidence-based clinical decision-making has become a strong trend. Yet all evidence-based decisions are only as sound as the evidence they are based on. In other studies, we could show that only 1 in 3 controlled orthopaedic trial accounts for confounding, and that there is even conflict in the results of meta-analyses, which are supposed to produce the highest level of evidence. This study asked how high the quality of evidence in orthopaedic research really is, and, thus, whether it would be applicable in “evidence”-based orthopaedics.

Method: All 2006 controlled trials from orthopedic journals with high impact-factor are analyzed in a cross-sectional study. A score based on the CONSORT statement was used to assess study quality. This score assesses power analyses, prospectiveness, randomization, allocation concealment and observer blinding, intention-to-treat, and how losses during follow-up were addressed. We also assessed whether there was an association between the test score and variables such as area of research and participation of a researcher with methodological training. Finally we tested the inter-observer reliability of our test between an investigator with postgraduate training in biostatistics and epidemiology and an orthopaedic resident with no specific methodological training beyond medical school.

Results: The overall quality of 126 studies was moderate to high, with an average score of 3.4 ± 1.7. The most neglected parameters were power analysis, intention-to-treat, and concealment. There were significant differences in results by area of research (p=0.022). The highest values were seen in oncology (4.6 ± 1.4) and osteoarthritis (4.4 ± 1.8), the lowest in traumatology (2.9 ± 1.3). The participation of a methodologically trained investigator increases study quality significantly (p=0.002). There is no difference in study quality whether there is statistically significant result or not (p=0.497). There was a 81.2% agreement, suggesting that study quality can be judged regardless of “specific training”.

Conclusion: We found good to high values for orthopaedic evidence on our scale, suggest high validity and applciability. We also saw that this instrument can be used without methodological training. However, there seems to be neglect of some important study features like power analyses, intention-to-treat, and concealment. Heightened awareness of this problem will help to increase the quality of orthopaedic evidence, and thus the clinical applicability of evidence-based orthopaedics.

Introduction: Transplantation of autologous chondrocites offers promising results. A new technique is now gaining ground which uses a “scaffolding” of hyaluronic acid (Hyalograft C©, Fidia, Italy).

Materials and methods: Thirty-five patients have been treated with Hyalograft C© since 2000. 31 were operated on for a knee and 4 for an ankle. Clinical progression was documented both preoperatively and postoperatively by means of a clinical protocol (VAS-Scale, Lysholm, ICRS, IKDC; AOFAS, Cincinnati). Twenty-one patients with knee lesions (11 had particular circumscribed defects, 7 had complex lesions and/or related lesions, 3 patients were given this indication as a last resort in an effort to avoid the use of a prosthesis) and 4 with ankle lesions were followed up for over 6 months postop.

Results: Assessment by means of the VAS-Scale showed a reduction in pain. In addition, it was possible to show an improvement in function ranging from 51 points pre-op to 75 points post-op on the Lysholm Score. In patients with particular lesions an improvement of 57 to 97 points was achieved. All of the 3 patients where the indication was used as a last resort received a prosthesis. In ankles, the improvement ranged between 2,5 to 6.3 points on the modified Cincinnati-Score.

Conclusions: In the case of the classical indication for isolated femoral defects, the results obtained with Hyalograft C© show similar results to I.C.A. In complex lesions, results were considerably worse. Osteoarthritis has shown itself not to be an indication for this technique. On the other hand, the use of Hyalograft C© makes it possible to perform transplants with a smaller surgical incision as well as to fill defects without resorting to sutures.

Aims: Collagen implants are used for repair of chondral defects. We investigated the behavior of human chondrocytes of either healthy or osteoarthritic joints and ovine chondrocytes and bone marrow stromal cells seeded in a collagen-GAG copolymer matrix comprising collagen type I, II and III. Methods: Cells were seeded on matrices and cultured for 12 hours, 4 days, 1 week, 2, 3, and 4 weeks. We evaluated morphology and biosynthetic activity of the cells by histological analysis, immunhistochemistry, electron microscopy, biochemical assays for glycosaminoglycans and DNA, and expression of collagens by RT-PCR. Results: From 12 h to 3 weeks the histology showed a increasing number of spherical cells, consistent with chondrocytic morphology except in the osteoarthritic-chondrocyte-seeded scaffolds. GAG analysis showed an increasing amount in all cell-types except osteoarthritic ones. Human chondro-cytes from healthy cartilage increased the amount from 0 μg/mg GAG at 12 hours to 0,9 μg/mg at 2 weeks. Ovine bone marrow stromal cells from 0,5 μg/mg GAG at 12 hours to 2,9 μg/mg at 4 weeks. Conclusions: The collagen trilayer matrix may be of value as a vehicle for chondro-cyte implantation harvested from healthy cartilage. This matrix also supports the expression of chondrocytic proteins in ovine bone marrow stromal cells without use of growth factors. However, chondrocytes from osteoarthritic cartilage revealed low bioactivity and can not be recommended for cell transplantation procedures.

Aims: The technique of microfracture for the arthroscopic treatment of articular cartilage (AC) defects has been shown to result in reparative tissue in the defect, however, retrieved tissues have demonstrated þbrocartilagenous material. The objective of this study was to evaluate the tissue types formed in AC defects in an ovine model treated by microfracture with a collagen- GAG-copolymer trilayer matrix consisting of collagen type I, II and III and autologous cultured cells. Methods: Sixteen adult sheep were used in the study following the protocol accepted by the Animal Care Commitee of the University. Two 4.5-mm diameter defects were produced in the medial condyle of the right knee, all AC was removed without penetrating the subchondral bone. In twelve animals microfracture was performed with a curved pick, in four of them without further treatment, in four the defect was covered by the collagen implant alone, and in four by the cell-seeded implant with cultured autologous chondrocytes from the left knee, 4 defects served as controls. After four months the knees were removed, parafþn sections were stained with H & E, Safranin O/fast green, alcian blue, azan, and antibodies to types I and II collagen. Results: All treatment groups showed better þlling of the defects than untreated knees. Histological analysis revealed the biggest amount of hyaline-like tissue in the cell augmented treatment group. Reparative tissue was predominantly þbrocartilage in the other groups. Conclusions: Collagen implants are able to increase the repair of chondral defects in combination with microfracture.

Introduction and Objectives: Autologous chondrocyte suspension implantation (ACSI) has yielded good to excellent results in the treatment of cartilaginous defects of the knee. Thus far, studies on the ankle, analysing fewer subjects, offer promising results. Use of this technique in the ankle joint requires medial malleolar arthrotomy and osteotomy. Matrix-induced chondrocyte implantation (MICI) is a new technique involving the use of a hyaluronic acid-based matrix containing cultured chondrocytes.

Materials and Methods: Eight patients (4 male, 4 female) with an average age of 31 years (21–43) with defects in the talus were treated using ACSI and MICI. Average defect size was 1.9 cm. All patients had previously undergone surgery, and MRI showed Outerbridge grade IV osteochondral lesions on the talus. After clinical and radiological evaluation, arthroscopic surgery was performed to biopsy the articular cartilage of the talus. Later, a second surgery was performed with a mini-arthrotomy and debridement and cleaning of the defect. In ACSI, the defect is covered by suturing a periosteal graft to the cartilage, and the chondrocyte suspension is injected underneath. In MICI, a sheet of hyaluronic acid matrix with autologous chondrocytes of the same size as the defect is placed on the defect site and attached with fibrin glue. Patients were examined 28 months after implantation and evaluated using the Hannover Scoring system for the ankle.

Results: Follow-up results on the 8 patients verified an improvement of joint function and a reduction of pain in all cases. Hannover Scores increased in all patients. The osteotomy of the malleolus healed in all 8 cases. One patient was able to return to active competition in decathlon events.

Discussion and Conclusions: MICI requires a less complex surgical procedure and allows for a smaller incision. This technique therefore represents a broader application of tissue engineering in the treatment of cartilaginous defects of the ankle.