W. Schultz

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.

Cartilage repair techniques of the talus: An update.

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients. Although their pathomechanism is well understood, it is well known that different aetiologic factors play a role in their origin. Additionally, it is well recognised that the talar articular cartilage strongly differs from that in the knee. Despite this fact, many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee. Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans. However, depending on the size of the lesions, surgical approaches are necessary to treat many of these defects. Bone marrow stimulation techniques may achieve good results in small lesions. Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation. Autologous chondrocyte transplantation, as a restorative procedure, is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor. The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.

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.

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.

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.

Implant detectibility of intervertebral disc spacers in post fusion MRI: evaluation of the MRI scan quality by using a scoring system—an in vitro study

IntroductionIntervertebral spacers for anterior spine fusion are made of different materials, such as titanium and cobalt chromium alloys and carbon fiber-reinforced polymers. Implant-related susceptibility artifacts can decrease the quality of MRI scans. The aim of this cadaveric study was to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of determined regions of interest (ROIs).MethodsIn six cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, cobalt-chromium and carbon spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into ROIs to characterize the spinal canal as well as the intervertebral disc space. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists the artifact-affected image quality of the median MRI slice was rated on a score of 0–3. A maximum score of 18 points (100%) for the determined ROIs was possible.ResultsTurbo spin echo sequences produced the best scores for all spacers and the control. Only the control achieved a score of 100%. For the determined ROI maximum scores for the cobalt-chromium, titanium and carbon spacers were 24%, 32% and 84%, respectively.ConclusionBy using favored T1 TSE sequences the carbon spacer showed a clear advantage in postfusion spinal imaging. Independent of artifact dimensions, the scoring system used allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.

Collagen IX in weight-bearing areas of human articular cartilage in late stages of osteoarthritis.

AimTo determine if the amounts of collagen IX mRNA and protein are higher in osteoarthritic cartilage from weight-bearing areas of the knee joint compared to non-weight bearing areas in patients with stage IV osteoarthritis (OA).MethodsNormal and OA cartilage samples were obtained from 15 patients undergoing total knee replacement or necropsies. mRNA was measured by real time RT-PCR and proteins were detected by Western blot and localized at the light and ultrastructural level.ResultsCollagen IX was found throughout all cartilage layers in healthy and OA tissue. Cells deposited collagen IX in the pericellular and interterritorial matrix and a 66% higher amount of collagen IX was detected in the pericellular matrix of the weight-bearing areas adjacent to the main defect in comparison to the macroscopically intact areas. This is in line with a 3.72 times higher amount of the respective mRNA.ConclusionThe increased levels of collagen IX protein and its mRNAs found in the weight-bearing areas adjacent to the main cartilage defect might reflect an attempt on the part of the diseased cartilage tissue to stabilize and protect the remaining matrix of late-stage osteoarthritic cartilage from further destruction.