Hans-Michael Klinger

Autologous Chondrocyte Transplantation for Treating Cartilage Defects of the Talus

BACKGROUND Despite its highly specialized nature, articular cartilage has a poor reparative capability. Treatment of symptomatic osteochondral defects of the talus has been especially difficult until now. METHODS We performed autologous chondrocyte transplantation in twelve patients with a focal deep cartilage lesion of the talus. There were seven female and five male patients with a mean age of 29.7 years. The mean size of the lesion was 2.3 cm(2). All patients were studied prospectively. Evaluation was performed with use of the Hannover ankle rating score, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, a visual analogue scale for pain, and magnetic resonance imaging. RESULTS All patients were available for follow-up at a mean of sixty-three months. There was a significant improvement in the Hannover score, from 40.4 points preoperatively to 85.5 points at the follow-up examination, with seven excellent results, four good results, and one satisfactory result. The AOFAS mean score was 88.4 points compared with 43.5 points preoperatively. Magnetic resonance imaging showed a nearly congruent joint surface in seven patients, discrete irregularities in four, and an incongruent surface in one. The patients who had been involved in competitive sports were able to return to their full activity level. CONCLUSIONS The promising clinical results of this study suggest that autologous chondrocyte transplantation is an effective and safe way to treat symptomatic osteochondral defects of the talus in appropriately selected patients.

Arthrodesis of the knee after failed infected total knee arthroplasty

Infection after total knee arthroplasty (TKA) can be a challenging and difficult problem to treat. In selected patients, knee arthrodesis is a well-recognized salvage procedure after infected TKA. The authors retrospectively reviewed their experience with this treatment option, presenting 20 patients (8 women, 12 men), performed between 1990 and 2002. The average age was 67 years (range: 47–81 years) and the mean number of previous surgical procedures was 6 (range: 4–11 procedures). There were multiple indications for knee arthrodesis, including extensive bone or soft tissue loss, poor bone stock, and recurring infections. One-stage fusion was done in 7 knees while, on the other 13, arthrodesis was performed as two-stage fusions. The average clinical follow-up was 4.5 years (range: 2–11 years). 18 of the 20 patients were interviewed and graded using the Visual Analogue Scale (VAS) for pain, the Short Form-36 Health Survey (SF-36), and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire that has knee-related quality of life items. According to the VAS, the mean intensity was 3.4 points. 6 (33%) of the patients had no difficulty with the knee and 9 (50%) of them had mild or moderate difficulty. The SF-36 scores were similar to those for normative data for patients after TKA, with only the social functioning, role emotional, and physical functioning scores being lower and the role physical and social functioning scores being higher. Three of 20 fusions failed, whereas two knees became non-infected non-unions. In one, the knee infection persisted and required above-knee amputation. The two-stage arthrodesis gave the most predictable rate of fusion. Persistent infection and extensive bone stock losses led to failure even under the best circumstances. In our opinion, arthrodesis of the knee is a satisfactory salvage procedure following a failed TKA, and can provide reliable expectation for a stable, painless extremity for high-functioning patients who are able to walk.

Anatomy of the anterior cruciate ligament double bundle structure: a macroscopic evaluation

Introduction: Traditional anterior cruciate ligament (ACL) surgery has demonstrated good results, but there is still a subset of unsatisfactory outcomes. Trends in reconstruction technique have changed from bone–patella–tendon–bone to hamstring refixation, and the next step appears to be the double bundle concept.

The double-bundle technique for anterior cruciate ligament reconstruction: a systematic overview

In traditional anterior cruciate ligament reconstruction, there is a subset of patients complaining of knee instability, especially rotational instability, and athletes not able to return to their preinjury level of sports activity. Currently, controversy exists over the usefulness of the double bundle technique (DBT) in addressing these problems. In order to evaluate the DBT, we completed a literature review from 1969 to February 2006 focusing on anatomy, magnetic resonance imaging, graft incorporation, biomechanics, kinematics, surgical techniques, complications and outcome. The DBT is not a standardized technique, which makes it difficult to compare results. Cadaver studies have proven biomechanical advantages with respect to ap‐stability, but assessing the rotational stability remains difficult. There is a lack of available outcome studies with sufficient follow‐up to demonstrate the potential advantages of DBT. The theoretical advantages of DBT require careful evaluation with outcome, biomechanical and kinematic studies. In addition, studies are needed to address issues such as graft incorporation and complications. An advantage offered by DBT is the possibility to identify rupture patterns that can lead to surgical preservation of an intact and augmentation of an injured bundle. The approach of augmentating a single bundle technique reconstruction with adequate anterior–posterior but poor rotational stability is promising.

The surgical technique of autologous chondrocyte transplantation of the talus with use of a periosteal graft. Surgical technique.

BACKGROUND Despite its highly specialized nature, articular cartilage has a poor reparative capability. Treatment of symptomatic osteochondral defects of the talus has been especially difficult until now. METHODS We performed autologous chondrocyte transplantation in twelve patients with a focal deep cartilage lesion of the talus. There were seven female and five male patients with a mean age of 29.7 years. The mean size of the lesion was 2.3 cm(2). All patients were studied prospectively. Evaluation was performed with use of the Hannover ankle rating score, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, a visual analog scale for pain, and magnetic resonance imaging. RESULTS All patients were available for follow-up at a mean of sixty-three months. There was a significant improvement in the Hannover score, from 40.4 points preoperatively to 85.5 points at the follow-up examination, with seven excellent results, four good results, and one satisfactory result. The AOFAS mean score was 88.4 points compared with 43.5 points preoperatively. Magnetic resonance imaging showed a nearly congruent joint surface in seven patients, discrete irregularities in four, and an incongruent surface in one. The patients who had been involved in competitive sports were able to return to their full activity level. CONCLUSIONS The promising clinical results of this study suggest that autologous chondrocyte transplantation is an effective and safe way to treat symptomatic osteochondral defects of the talus in appropriately selected patients.

The interobserver-validated relevance of intervertebral spacer materials in MRI artifacting

Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium, carbon or cobalt-chrome, which can affect the post-fusion MRI scans. Implant-related susceptibility artifacts can decrease the quality of MRI scans, thwarting proper evaluation. This cadaver study aimed to demonstrate the extent that implant-related MRI artifacting affects the post-fusion evaluation of intervertebral spacers. In a cadaveric porcine spine, we evaluated the post-implantation MRI scans of three intervertebral spacers that differed in shape, material, surface qualities and implantation technique. A spacer made of human cortical bone was used as a control. The median sagittal MRI slice was divided into 12 regions of interest (ROI). No significant differences were found on 15 different MRI sequences read independently by an interobserver-validated team of specialists (P>0.05). Artifact-affected image quality was rated on a score of 0-1-2. A maximum score of 24 points (100%) was possible. Turbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. The carbon, titanium and cobalt-chrome spacers scored 83.3, 62.5 and 50%, respectively. Our scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the control that was independent of artifact dimensions. The carbon spacer had the lowest percentage of susceptibility artifacts. Even with turbo spin echo sequences, the susceptibility artifacts produced by the metallic spacers showed a high degree of variability. Despite optimum sequencing, implant design and material are relevant factors in MRI artifacting.

Biomechanical and magnetic resonance imaging evaluation of a single- and double-row rotator cuff repair in an in vivo sheep model.

PURPOSE To investigate the biomechanical and magnetic resonance imaging (MRI)-derived morphologic changes between single- and double-row rotator cuff repair at different time points after fixation. METHODS Eighteen mature female sheep were randomly assigned to either a single-row treatment group using arthroscopic Mason-Allen stitches or a double-row treatment group using a combination of arthroscopic Mason-Allen and mattress stitches. Each group was analyzed at 1 of 3 survival points (6 weeks, 12 weeks, and 26 weeks). We evaluated the integrity of the cuff repair using MRI and biomechanical properties using a mechanical testing machine. RESULTS The mean load to failure was significantly higher in the double-row group compared with the single-row group at 6 and 12 weeks (P = .018 and P = .002, respectively). At 26 weeks, the differences were not statistically significant (P = .080). However, the double-row group achieved a mean load to failure similar to that of a healthy infraspinatus tendon, whereas the single-row group reached only 70% of the load of a healthy infraspinatus tendon. No significant morphologic differences were observed based on the MRI results. CONCLUSIONS This study confirms that in an acute repair model, double-row repair may enhance the speed of mechanical recovery of the tendon-bone complex when compared with single-row repair in the early postoperative period. CLINICAL RELEVANCE Double-row rotator cuff repair enables higher mechanical strength that is especially sustained during the early recovery period and may therefore improve clinical outcome.

Knorpelregeneration nach valgisierender Tibiakopfosteotomie. Ergebnisse einer arthroskopischen Studie

AIM High tibial osteotomy (HTO) has been established as an effective method for the treatment of unicondylar knee osteoarthritis. This study was undertaken to quantify the potential for restoration of cartilage lesions or defects after HTO in relation to different cartilage treatment modalities. Control arthroscopy was undertaken to identify the cartilage lesions within the knee joint 1.5 years after medial opening wedge osteotomy. MATERIAL AND METHOD A total of 135 patients (72 male and 63 female) had undergone medial-opening high tibial osteotomy and arthroscopy. The mean age at operation was 48.8 (36 to 65) years. All HTO were fixed with an angle-stable, mobile spacer-containing plate (HTO-Platte, Königsee, Deutschland). All HTO were combined with a simultaneous arthroscopy. Grade III cartilage lesions had undergone either shaving or temperature-controlled chondroplasty (Paragon ArthroW Austin, TX, USA). In some case these cartilage lesions had remained untreated. Control arthroscopy and removal of the implants was performed 1.5 years after HTO. The cartilage lesions were graded accordingly to the ICRS guidelines (International Cartilage Repair Society). RESULTS The KOOS at HTO was 49.9 (SD 10.6) points. We observed at follow-up a mean increase from 66.1 (SD 28.8, 95 % CI: 61.2-71.1) points. The KOOS at follow-up was 16.1 (SD 29.8) points. There was no delayed union of the HTO space. Before HTO the varus angle was 10.4° (SD 3.9 range 5 to 20°). The correction angle was 13.6° (SD 4.4, 95 % CI: 12.9-14.4°). Finally we determined a valgus angle of -3.2° (SD 1.8 minimum 0° varus, maximum -6° valgus. The clinical outcome (KOOS) significantly (p < 0.001) correlated (R = 0.605) with the extension of valgisation. Patients with a valgus angle of 3° and more had the best outcome. Of the grade III lesions 40.4 % in the medial femoral condyle and 62.3 % in the medial tibial plateau increased to grade II or I lesions. In 13.1 % of the medial femoral condyle and 8.5 % of medial tibial plateau cases we found complete (grade IV) defects at control arthroscopy. The highest rate of regenerations was detected after temperature-controlled chondroplasty. The worst results were produced after mechanical debridement. Microfracturing of complete defects produced regeneration in about ⅔ in the medial femoral condyle and about ⅓ in the medial tibial plateau. No increase was observed within the lateral or patello-femoral compartment. No correlation was seen between cartilage regeneration and outcome. The extension of valgisation did not influence the cartilage regeneration. CONCLUSIONS The main effect of the HTO is the shift of the weight-bearing line from the arthritic compartment to the opposite femorotibial healthy one. In addition, HTO also produces a partial restoration of cartilage lesions. Deep cartilage lesions (grade III) restore in about 60 % of the cases after HTO. The worst restoration is found after mechanical shaving. This method should be avoided in the future. The best restoration was found in deep lesions after thermochondroplasty. Furthermore, in about half of the patients with complete (grade IV) defects, microfracturing caused the formation of fibrocartilaginous regenerates. This procedure should always be performed if possible.

Morbus Teutschländer - a massive soft-tissue calcification of the foot in a patient on long-term hemodialysis.

Abstract. Morbus Teutschländer is a benign metabolic disorder involving soft-tissue masses near large joints and a rarely observed form of extraskeletal calcifications. For example, it is seen in patients with chronic renal failure, but in most cases it remains clinically silent. In a minority of patients, this soft-tissue calcification is responsible for complications. Various locations of calcium deposits have been characterized. Advanced age and increased calcium × phosphate product are some of the underlying reasons, but local factors are involved as well. Prevention should be preferred because the treatment is generally difficult. We describe the case of a morbus Teutschländer in a 58-year-old woman with chronic renal failure on hemodialysis presenting with a massive soft-tissue calcification of the foot with a compression of a cutaneous nerve secondary due to uremic tumoral calcinosis. The tumoral masses was successfully excised, and at the 1-year follow-up, the patient had no discomfort. Clinical and radiological features and treatment are discussed, and a review of soft-tissue calcifications is given.

Cell biological and biomechanical evaluation of two different fixation techniques for rotator cuff repair.

Our objective was to evaluate the cell biology and biomechanical aspects of the healing process after two different techniques in open rotator cuff surgery – double‐loaded bio‐absorbable suture anchors combined with so‐called arthroscopic Mason–Allen stitches (AAMA) and a trans‐osseous suture technique combined with traditional modified Mason–Allen stitches (SMMA). Thirty‐six mature sheep were randomized into two repair groups. After 6, 12, or 26 weeks, evaluation of the reinsertion site of the infraspinatus tendon was performed. The mechanical load‐to‐failure and stiffness results did not indicate a significant difference between the two groups. After 26 weeks, fibrocartilage was sparse in the AAMA group, whereas the SMMA group showed the most pronounced amount of fibrocartilage. We found no ultrastructural differences in collagen fiber organization between the two groups. The relative expression of collagen type II mRNA in the normal group was 1.11. For the AAMA group, 6 weeks after surgery, the relative expression was 55.47, whereas for the SMMA group it was 1.90. This in vivo study showed that the AAMA group exhibited a tendon‐to‐bone healing process more favorable in its cell biology than that of the traditional SMMA technique. Therefore, the AAMA technique might also be more appropriate for arthroscopic repair.