Andreas Lahm

Arthroscopic Management of Osteochondral Lesions of the Talus: Results of Drilling and Usefulness of Magnetic Resonance Imaging Before and After Treatment

Since the advent of operative ankle arthroscopy and magnetic resonance imaging (MRI) specific treatment of osteochondritis dissecans of the talus has progressed rapidly. Drilling is still the treatment of choice in early stages of osteochondritis dissecans of the talus. Rear-entry guides and preoperative planning with MRI have led to better results with this kind of treatment. Within 5 years, 42 patients (26 male and 16 female) underwent arthroscopic treatment of osteochondritis dissecans of the talus, 22 underwent percutaneous drilling, 13 cancellous bone grafting, 4 refixation, and 3 curettage. The average age of the patients was 28 years (range, 11 to 53 years). A clinical score system was used in a clinical and MRI follow-up of 19 of the patients with K-wire drilling. Up to 100 points are given in the categories pain, stability/insecurity, efficiency/pain-free walking distance, gait, differences in circumference, range of motion, and power. There was a history of trauma in 31 of the 42 patients. The majority of lesions (24 cases) were localized at the lateral talus, and these patients all had trauma. In 11 of the 18 lesions at the medial talus, there was no evidence of trauma. The 19 patients in the follow-up achieved an average of 87 points. K-wire drilling represents the chief component of early stages with intact or partially fractured cartilage surface, whereas arthroscopically controlled cancellous bone grafts after curettage are used in grade II stages only. Results of K-wire drilling are not worse than those of cancellous bone grafts; this is attributable to a generous perforation of the sclerosis. This has contributed to an improved preoperative diagnosis with MRI.

Mosaicplasty With Autogenous Talar Autograft for Osteochondral Lesions of the Talus After Failed Primary Arthroscopic Management A Prospective Study With a 4-Year Follow-up

Background There have been limited data in the literature reporting the results of osteochondral autografting for osteochondral lesions of the talus that have failed arthroscopic treatment. Hypothesis Osteochondral autografting can produce significant clinical improvement and a high rate of healing of osteochondral defects of the talus that have failed arthroscopic treatment. Study Design Cohort study; Level of evidence, 4. Methods Between 1998 and 2003, 35 patients (18 men, 17 women) with osteochondral talar lesions for which arthroscopic excision, curettage, and drilling had failed, underwent mosaicplasty with an osteochondral graft harvested from the ipsilateral talar articular facet. A malleolar osteotomy or a tibial wedge osteotomy was used for central or posterior lesions that could not otherwise be reached. The mean age of the patients was 30.9 years, and the mean follow-up was 48.9 months. Results The American Orthopaedic Foot and Ankle Society Ankle Hindfoot scale score in patients without osteotomy rose by 39 points (P =. 0001); with malleolar osteotomy, by 30.1 points (P =. 017); with tibial wedge osteotomy, by 34.9 points (P =. 0002); and with the posterolateral approach, by 32 points. The Wilcoxon test revealed a significant difference between patients without and with osteotomy (P =. 027) and between patients with malleolar and tibial wedge osteotomies (P =. 046). There were no patients with nonunion or malunion in the osteotomy groups. The score values corresponded with the subjective patient evaluation. The Spearman coefficient of correlation was. 89. Conclusion Osteochondral autografting with tibial wedge osteotomy is a good alternative to malleolar osteotomy in osteochondral talar lesions that have failed arthroscopic treatment and that cannot be reached in spite of a forced plantar flexion of the ankle. Patients with small osteochondral lesions accessible through an anterior approach without additional osteotomy have the best prognostic factors.

Cell-laden and cell-free biopolymer hydrogel for the treatment of osteochondral defects in a sheep model.

The objective of the current study was to determine the suitability of cell-laden and cell-free alginate-gelatin biopolymer hydrogel for osteochondral restoration in a sheep model (n = 12). Four femoral defects per animal were filled with hydrogel (cHG) plus autologous chondrocytes (cHG + C) or periosteal cells (cHG + P) or gel only (cHG) or were left untreated (E). In situ solidification enabled instantaneous implant fixation. Sixteen weeks postoperatively, defect sites were processed for light microscopy and immunofluorescence. A modified Mankin and a semi-quantitative immunoreactivity score were used to evaluate histology and immunofluorescence, respectively. Defects after cHG + C were restored with smooth, hyaline-like neo-cartilage and trabecular subchondral bone. cHG + P and cHG treatments revealed slightly inferior regenerate morphology. Undifferentiated tissue was found in E. The histological score showed significant (p < 0.05) differences between all treatment groups. In conclusion, cHG induces satisfactory defect regeneration. Complete filling of the cavity in one step and subsequent rapid in situ solidification was feasible and facilitated graft fixation. Cell implantation might be beneficial, because cells seem to play a key role in histological outcome. Still, their contribution to the repair process remains unresolved because host cell influx takes place. The combination of alginate and gelatin, however, creates an environment capable of serving implanted and host cells for osteo-chondrogenic tissue regeneration.

Articular cartilage degeneration after acute subchondral bone damage : An experimental study in dogs with histopathological grading

Background Subchondral fracture patterns and bone bruises have been described and some clinical studies have shown alterations in the initially healthy cartilage after such lesions. Methods and results After having performed cadaver studies, we created an animal model to produce pure subchondral damage without affecting the articular cartilage, under MRI control. We used 12 beagle dogs. For quantification of different degrees of staining, we used a grading of the sections by means of the HHGS (Histological-Histochemical Grading System) or Mankin score. Results In all cases, FLASH 3D sequences revealed intact cartilage in MRI after impact. The best detection of subchondral fractures was achieved in fat-suppressed TIRM sequences. Image analysis based on the HHGS showed changes in 10 of 12 samples, with a high degree of significance 6 months after the initial trauma. Correlation analysis showed loss of the physiological distribution of proteoglycans and glycoproteins in the different zones of articular cartilage. Subcategories “Structure”, “Cells” and “Safranin-O Staining” also showed high significance, and the category “Tidemark Integrity” showed a tendency. Interpretation Our findings indicate that acute subchondral fractures are a predictor of degenerative changes within 6 months. Modifications and supplements to rehabilitation might be needed in cases with accompanying subchondral lesions, e.g. in ACL tears.

Articular and osseous lesions in recent ligament tears: arthroscopic changes compared with magnetic resonance imaging findings

The treatment of ligament injuries of the knee has undergone rapid progress, especially with the improvement of arthroscopic reconstruction of the anterior cruciate ligament (ACL). Since the advent of magnetic resonance imaging (MRI) after knee trauma with ligament injuries, interest has focussed on the clinical significance of concomitant articular and osseous lesions. In 48 of 141 MRIs, different types of these lesions were found; in 38 cases an arthroscopy was performed and 34 times the patients could clinically and radiologically be examined after at least 6 months. Bone bruise was found 26 times, in 16 cases associated with ACL-tears. Eleven patients had subchondral fractures, 7 osteochondral fractures, and in 4 patients, stress fractures were found. They were attributed to various mechanisms of trauma, in different percentages associated with ligament tears and in different dimensions visible or progressive on follow-up MRIs. Obviously some of the different lesions of subchondral and spongeous bone can indicate later degenerative arthritis, so that we find hints for a modification of rehabilitation, e.g., open versus closed kinetic chain or orthosis with relief of single compartments.

Autologous chondrocyte implantation (ACI) for the treatment of large and complex cartilage lesions of the knee

BackgroundComplex cartilage lesions of the knee including large cartilage defects, kissing lesions, and osteoarthritis (OA) represent a common problem in orthopaedic surgery and a challenging task for the orthopaedic surgeon. As there is only limited data, we performed a prospective clinical study to investigate the benefit of autologous chondrocyte implantation (ACI) for this demanding patient population.MethodsFifty-one patients displaying at least one of the criteria were included in the present retrospective study: (1.) defect size larger than 10 cm2; (2.) multiple lesions; (3.) kissing lesions, cartilage lesions Outerbridge grade III-IV, and/or (4.) mild/moderate osteoarthritis (OA). For outcome measurements, the International Cartilage Societys International Knee Documentation Committees (IKDC) questionnaire, as well as the Cincinnati, Tegner, Lysholm and Noyes scores were used. Radiographic evaluation for OA was done using the Kellgren score.Results and DiscussionPatients age was 36 years (13-61), defects size 7.25 (3-17.5) cm2, previous surgical procedures 1.94 (0-8), and follow-up 30 (12-63) months. Instruments for outcome measurement indicated significant improvement in activity, working ability, and sports. Mean ICRS grade improved from 3.8 preoperatively to grade 3 postoperatively, Tegner grade 1.4 enhanced to grade 3.39. The Cincinnati score enhanced from 25.65 to 66.33, the Lysholm score from 33.26 to 64.68, the Larson score from 43.59 to 79.31, and Noyes score from 12.5 to 46.67, representing an improvement from Cincinnati grade 3.65 to grade 2.1. Lysholm grade 4 improved to grade 3.33, and Larson grade 3.96 to 2.78 (Table 1), (p < 0.001). Patients with kissing cartilage lesions had similar results as patients with single cartilage lesions.Table 1Mean scores and grades at surgery (Tx) and at follow-upTxFollow-upScoreGradeScoreGradeICRS43Tegner13Noyes1347Cincinnati264662Lysholm334653Larson444793ConclusionOur results suggest that ACI provides mid-term results in patients with complex cartilage lesions of the knee. If long term results will confirm our findings, ACI may be a considered as a valuable tool for the treatment of complex cartilage lesions of the knee.

Clinical and cellbiological aspects of autologous chondrocytes transplantation

SummaryThe treatment of deep cartilage defects is a challenge for every orthopeadic surgeon. The potention for regeneration of cartilage tissue is minimal and leads to mechanically inferior fibrous tissue. The established techniques induce the growth of fibrous tissue but fail to prevent arthrosis. Autologous chondrocyte transplantation seems to be the most promising therapy concept with clinical relevance to reserves a full thickness cartilage defekt with hyaline-like cartilage. Outcome studies with a follow up from 2–10 years show in up to 90 % good and excellent results for defects on the femoral condyle and 70 % for the patella. Mechanical testing of the regenerated cartilage showed almost simular stiffness as nearly normal hyaline cartilage. The available data justify the acceptance of autologous chondrocyte transplantation as a standard procedure for limited indications and well-trained surgeons. Result of already inaugurated studies will show the potential of chondrocyte transplantation to prevent osteoarthritis.ZusammenfassungGelenkknorpeldefekte gelten als schwer zu therapieren. Die Regenerationspotenz des Knorpelgewebes ist gering und führt zur Bildung von mechanisch minderwertigem Faserknorpel. Die etablierten Behandlungsmethoden können zwar die Bildung von Faserknorpel induzieren, die Entstehung einer Arthrose jedoch nicht verhindern. Die autologe Chondrozytentransplantation (ACT) stellt gegenwärtig das vielversprechendste klinisch einsetzbare neue Verfahren dar, mit welchen ein dem hyalinen Gelenkknorpel sehr ähnliches Regeneratgewebe im Defektbereich gebildet werden kann. Die jetzt vorliegenden wissenschaftlichen Ergebnisse zeigen über einen Nachuntersuchungszeitraum von 2–10 Jahren zu 90 % gute und sehr gute klinische Ergebnisse bei Anwendung an der Femurkondyle und ca. 70 % gute und sehr gute Ergebnisse bei der Behandlung von patellaren Knorpelschäden. Die Festigkeit dieses Regenerats liegt mit Werten von 2,77 N sehr nahe an Werten für gesunden hyalinen Gelenkknorpel (3,08 N). Bei strenger Indikations-stellung rechtfertigen die vorliegenden mittelfristigen Ergebnisse bereits jetzt einen klinischen Einsatz an speziellen Zentren. Ob diese Methode die Entstehung einer Arthrose verhindern kann, müssen die langfristigen Ergebnisse zeigen.

Changes in content and synthesis of collagen types and proteoglycans in osteoarthritis of the knee joint and comparison of quantitative analysis with Photoshop-based image analysis

IntroductionThe different cartilage layers vary in synthesis of proteoglycan and of the distinct types of collagen with the predominant collagen Type II with its associated collagens, e.g. types IX and XI, produced by normal chondrocytes. It was demonstrated that proteoglycan decreases in degenerative tissue and a switch from collagen type II to type I occurs. The aim of this study was to evaluate the correlation of real-time (RT)-PCR and Photoshop-based image analysis in detecting such lesions and find new aspects about their distribution.PatientsWe performed immunohistochemistry and histology with cartilage tissue samples from 20 patients suffering from osteoarthritis compared with 20 healthy biopsies. Furthermore, we quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorimetrically. Using Adobe Photoshop the digitized images of histology and immunohistochemistry stains of collagen type I and II were stored on an external data storage device. The area occupied by any specific colour range can be specified and compared in a relative manner directly from the histogram using the “magic wand tool” in the select similar menu. In the image grow menu gray levels or luminosity (colour) of all pixels within the selected area, including mean, median and standard deviation, etc. are depicted. Statistical Analysis was performed using the t test.MethodWith the help of immunohistochemistry, RT-PCR and quantitative RT- PCR we found that not only collagen type II, but also collagen type I is synthesized by the cells of the diseased cartilage tissue, shown by increasing amounts of collagen type I mRNA especially in the later stages of osteoarthritis.ResultsA decrease of collagen type II is visible especially in the upper fibrillated area of the advanced osteoarthritic samples, which leads to an overall decrease. Analysis of proteoglycan showed a loss of the overall content and a quite uniform staining in the different zones compared to the healthy cartilage with a classical zonal formation. Correlation analysis of the proteoglycan Photoshop measurements with the RT-PCR using Spearman correlation analysis revealed strong correlation for Safranin O and collagen type I, medium for collagen type II and glycoprotein but weak correlation between PCR aggrecan results.ConclusionPhotoshop-based image analysis might become a valuable supplement for well known histopathological grading systems of lesioned articular cartilage.

Semiquantitative analysis of ECM molecules in the different cartilage layers in early and advanced osteoarthritis of the knee joint

The study was conducted to examine the expression of collagen type I and II in the different cartilage layers in relation to other ECM molecules during the progression of early osteoarthritic degeneration in human articular cartilage (AC). Quantitative real-time (RT)-PCR and colorimetrical techniques were used for calibration of Photoshop-based image analysis in detecting such lesions. Immunohistochemistry and histology were performed with 40 cartilage tissue samples showing mild (ICRS grade 1b) respectively moderate/advanced (ICRS grade 3a or 3b) (20 each) osteoarthritis compared with 15 healthy biopsies. Furthermore, we quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorimetrically. The digitized images of histology and immunohistochemistry stains were analyzed with Photoshop software. T-test and Spearman correlation analysis were used for statistical analysis. In the earliest stages of AC deterioration the loss of collagen type II was associated with the appearance of collagen type I, shown by increasing amounts of collagen type I mRNA. During subsequent stages, a progressive loss of structural integrity was associated with increasing deposition of collagen type I as part of a natural healing response. A decrease of collagen type II is visible especially in the upper fibrillated area of the advanced osteoarthritic samples, which then leads to an overall decrease. Analysis of proteoglycan showed losses of the overall content and a loss of the classical zonal formation. Correlation analysis of the proteoglycan Photoshop measurements with the RT-PCR revealed strong correlation for Safranin O and collagen type I, medium for collagen type II, alcian blue and glycoprotein but weak correlation with PCR aggrecan results. Photoshop based image analysis might become a valuable supplement for well known histopathological grading systems of lesioned articular cartilage. The evidence of collagen type I production early in the OA disease process coupled with the ability of chondrocytes to up-regulate collagen type II production suggests that therapeutic agents that suppress collagen type I production and increase collagen type II production may enable chondrocytes to generate a more effective repair response.

Regression and correlation analysis of preoperative versus intraoperative assessment of axes during navigated total knee arthroplasty.

Objective: Modern computer assisted surgery (CAS) systems allow accurate positioning of the implants in navigated Total Knee Arthroplasty (TKA). However, when an operation is performed with a navigation system, it is important to know if the anatomical situation of the knee is reflected equally in both the preoperative image (e.g., CT) and the intraoperative navigation setup. In this study, we compared the preoperative anatomical situation to the virtual intraoperative situation of the navigation setup. Material and Methods: We analyzed 24 navigated operations. Intraoperatively, the condylar twist angle (CTA) was documented with the navigation system by measuring the angle between the transepicondylar axis (TEA) and posterior condyle axis (PCA). This data was compared with the preoperative data from the CT scan. Results: Statistical analysis revealed that there was no correlation between the pre- and intraoperative data (r = 0.095).Conclusions: Statistically, there is no possibility of collecting the same angles and axes when using the two different methods (CT and navigation) on the same knee. It is not possible to copy the preoperative anatomical situation exactly with the virtual intraoperative data. Reasons for this include systematic errors, as well as inter- and intraobserver errors in both methods.