Unterschenkel-Muskelatrophie bei Arthrose des oberen Sprunggelenks und deren Rehabilitation nach Implantation einer Sprunggelenksprothese

The aim of this orthopaedic-biomechanical study was to evaluate lower leg muscle function in ankle osteoarthritis (OA) patients and muscle rehabilitation after the implantation of a total ankle replacement (TAR). Patients with a severe unilateral ankle OA were assessed with an orthopaedic and biomechanical examination before and one year after TAR surgery. Visual analogue pain score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle score, ankle range of motion for dorsi- and plantar flexion (ROM DF/PF), and calf circumference difference between affected and contralateral healthy leg were measured. Isometric maximal voluntary torque for ankle dorsiflexion and plantar flexion were measured simultaneously with surface electromyography (EMG; mean frequency and intensity) of the anterior tibial, medial gastrocnemius, soleus, and peroneus longus muscle. Data were compared to a group of age- and gender-matched normal subjects. The mean calf circumference difference between legs did not significantly decrease from preoperative to one year follow-up. The mean dorsiflexion torque and plantar flexion torque of the affected ankle increased significantly. The atrophic muscles were characterized by a reduction of the mean EMG intensity and mean EMG frequency. In the rehabilitation process, the mean EMG intensity recovered and was not significantly different for all muscles, however, not for EMG frequency, which remained low and unchanged. This study reports for the first time in the literature the clinical and biomechanical facts of lower leg muscle atrophy in ankle OA as well as the amount of the muscle rehabilitation after a total ankle replacement. Patients with a symptomatic ankle OA achieve better function with a total ankle replacement; however, one year after the operation neuromuscular and biomechanical deficits may still be present.     

Is there clinical evidence to support autologous matrix-induced chondrogenesis (AMIC) for chondral defects in the talus? A systematic review and meta-analysis

BackgroundThe aim of this study is to systematically review the literature on clinical outcomes of patients who have undergone autologous matrix-induced chondrogenesis (AMIC) for treatment of osteochondral lesions of the talus (OCL) and compare the studies’ outcomes.MethodsPubmed and Embase were searched in January 2020 for articles concerning OCL surgery. Studies were included if they had a minimum 1-year follow-up and the primary measures were functional outcomes. The meta-analysis compared the Visual Analogic Score (VAS), the American Orthopedic Foot and Ankle Score (AOFAS), and the Foot Function Index (FFI) between baseline and follow-up of 1?2 years, and 3?5 years. A random effects model was used to evaluate outcome changes.ResultsThe search returned 15 studies, with a total of 492 patients. The VAS improved 4.45 and 4.6 points from baseline to the 1?2 year and 3?5 year follow-up, respectively (p < 0.001). AOFAS improved 31.59 and 32.47 points from baseline to the 1?2 year and 3?5 year follow-up, respectively (p < 0.001). The FFI showed a significant improvement of 30.93 points from baseline to year 3?5 (p < 0.001). A total of 6 patients with revision surgeries have been reported within the follow up period. It was not possible to correlate clinical features like lesion size, surgical approach, and bone marrow stimulation technique to the reported outcome.ConclusionSurgical treatment of OCL via the AMIC procedure provided significant improvement in the functional outcome and pain scores when compared to the pre-operative values. Improvements were observed up to 5 years post-operatively.     

Knöchelosteotomie – Die Osteotomie als Zugang

Both arthroscopic and open surgical techniques may be used for treatment of osteochondral lesions of the ankle joint. Osteotomy around the ankle joint is a well established technique to extend the approach in cases where the osteochondral lesions are located more posteriorly. Medial, oblique, monoplanar malleolar osteotomy should be used in patients with lesions of the medial talus shoulder. The posterolateral ostechondral lesions are less frequent and in such cases distal fibular osteotomy is recommended. In this study the indications for different forms of osteotomy are discussed and the surgical techniques are described.     

Worldwide Experience with the Robotic Navigation System in Catheter Ablation of Atrial Fibrillation: Methodology, Efficacy and Safety

Worldwide Survey on Robotic AF Ablation . Introduction: The Hansen Robotic system has been utilized in ablation procedures for atrial fibrillation (AF). However, because of the lack of tactile feedback and the rigidity of the robotic sheath, this approach could result in higher risk of complications. This worldwide survey reports a multicenter experience on the methodology, efficacy, and safety of the Hansen system in AF ablations. Methods and Results: A questionnaire addressing questions on patient's demographics, procedural parameters, ablation success rate and safety information was sent to all centers where more than 50 robotic AF ablation cases have been performed. From June 2007 to December 2009, 1,728 procedures were performed at 12 centers utilizing the Hansen robotic navigation technology. The overall complication rate was 4.7% and the success rate was 67.1% after 18 ± 4 months of follow‐up. In 5 low volume centers there appeared to be a learning curve of about 50 cases (complication rate 11.2% for the first 50 cases vs 3.7% for the 51–100 cases; P = 0.044) and a trend showing a decrease of complication rate with increasing case volume. However, in the remaining 7 centers no learning curve was present and the complication rate was stable over time (3.7% for the first 50 cases vs 3.6% for the 51st case thereafter; P = 0.942). Conclusion: The Hansen robotic system can be used for AF ablation safely. In low volume centers, there appeared to be a learning curve of the first 50 cases after which the complication rate decreased. With a higher case volume, the success rate increased. (J Cardiovasc Electrophysiol, Vol. 23, pp. 820‐826, August 2012)     

Lateral Patellar Facetectomy and Medial Reefing in Patients With Lateral Facet Syndrome After Patellar-Retaining Total Knee Arthroplasty

We analyzed clinical outcomes of partial lateral patellar facetectomy and medial reefing in patients with lateral patellar facet syndrome with painful patellar-retaining total knee arthroplasty. 34 patients were followed for a mean of 40 months. All 34 patients were matched with those having secondary patellar resurfacing without facetectomy. Both groups experienced significant pain relief and range of motion improvement. The facetectomy group had higher Kujala scores than those in patellar resurfacing group. Patients with facetectomy had significantly less pain postoperatively. There were significant differences in postoperative lateral patellar tilt and congruency angle in both groups. The mid-term results for LPF with medial reefing are promising to resolve pain in patients with lateral patellar facet syndrome in patellar-retaining TKA. Therapeutic level III (retrospective comparative study).     

Influence of screw type on obtained contact area and contact force in a cadaveric subtalar arthrodesis model

The purpose of this study was to compare the compression effect of the 7.0-AO screw and the 6.5 mm Ideal Compression Screw (I.CO.S.) screw in an in vitro subtalar arthodesis model. Six fresh-frozen, human cadaver foot specimens were obtained for analysis. The subtalar joint was opened laterally without affecting the articular surfaces. ATekscan 5051 sensor with a maximum pressure of 250 PSI and a sensel-density of 62 sensel/sq-cm was placed into the joint, which allowed for continuous measurement of the contact area and contact forces achieved by one 7.0 AO-screw, and thereafter by one 6.5 I.CO.S.-screw. When tightening the screw, mean contact area increased by 0.21 cm2 for the AO-screw (p<0.05), and by 0.27 cm2 for the I.CO.S.-screw (p>0.05). When comparing the tightened AO-screw and I.CO.S.-screw, mean contact area increased from 1.40 cm2 to 1.97 cm2 (p<0.05). The mean contact force also increased when tightening the screws. This increase was 7.6 N for the AO-screw (p<0.05) and 14.8 N for the I.CO.S.-screw (p>0.05). When comparing the tightened AO-screw and I.CO.S.-screw, mean contact force increased from 54.9 N to 81.7 N (p<0.05). The obtained results have shown that the design of the screw influences the achieved compression force. The superior compression of the I.CO.S.-screw might be explained by the better gripping and additional compression mechanism of its head. The shape of the head of the cannulated AO-screw, in contrast, may be critical to resist against the weak cortical bone of the calcaneus, i.e. it can sink into soft bone resulting in a loss of compression force.