Alloplastic Reconstruction of the Extensor Mechanism after Resection of Tibial Sarcoma

Reconstruction of the extensor mechanism is essential for good extremity function after endoprosthetic knee replacement following tumor resection. Only a few biological methods have been able to reliably restore a functional extensor mechanism, but they are often associated with significant complication rates. Reattachment of the patellar tendon to the prosthesis using an alloplastic patellar ligament (Trevira cord) can be an appropriate alternative. In vivo and in vitro studies have already shown that complete fibrous ingrowth in polyethylene chords can be seen after a period of six months. However, until now, no biomechanical study has shown the efficacy of an alloplastic cord and its fixation device in providing sufficient stability and endurance in daily life-activity until newly formed scar tissue can take over this function. In a special test bench developed for this study, different loading regimes were applied to simulate loads during everyday life. Failure loads and failure modes were evaluated. The properties of the cord were compared before and after physiological conditioning. It was shown that rubbing was the mode of failure under dynamic loading. Tensile forces up to 2558 N did not result in material failure. Thus, using an artificial cord together with this fixation device, temporary sufficient stable fixation can be expected

Cefazolin Irreversibly Inhibits Proliferation and Migration of Human Mesenchymal Stromal Cells

Drugs may have a significant effect on postoperative bone healing by reducing the function of human mesenchymal stromal cells (hMSC) or mature osteoblasts. Although cefazolin is one of the most commonly used antibiotic drugs in arthroplasty to prevent infection worldwide, there is a lack of information regarding how cefazolin affects hMSC and therefore may have an effect on early bone healing. We studied the proliferation and migration capacity of primary hMSC during cefazolin treatment at various doses for up to 3 days, as well as the reversibility of the effects during the subsequent 3 days of culture without the drug. We found a timeand dose-dependent reduction of the proliferation rate and the migratory potential. Tests of whether these effects were reversible revealed that doses ≥250 g/mL or treatments longer than 24 h irreversibly affected the cells. We are the first to show that application of cefazolin irreversibly inhibits the potential of hMSC for migration to the trauma site and local proliferation. Cefazolin should be administered only at the required dosage and time to prevent periprosthetic infection. If long-term administration is required and delayed bone healing is present, cefazolin application must be considered as a cause of delayed bone healing

A novel technique to treat Grisel's syndrome: Results of a simplified, therapeutical algorithm

PURPOSE: Grisel’s syndrome is a rare entity and usually develops in paediatric patients after otolaryngologic surgery or infection. It is defined as a fixed torticollis combined with a rotatory atlanto-axial subluxation. The success rate of physiotherapy is low. Conventional therapy concepts imply stage-related recommendations based on the Fielding classification (type I–IV). This classification was introduced in 1977 to assess the degree of subluxation between atlas (C1) and axis (C2). Thus, instability increases from type I to IV. Higher stages may require surgical intervention. The purpose of this study was to evaluate the value of an alternative, less invasive treatment protocol in Grisel’s syndrome. METHODS: Irrespective of the underlying Fielding type we treated five children (Fielding type I–III) by manual repositioning under general anaesthesia. Consecutively, the cervical spine was immobilized with a Minerva cast for four to eight weeks. Additional surgical treatment or immobilization in a Halo-Fixateur was not necessary. RESULTS: Overall period of treatment was reduced, even in patients with delayed diagnosis. No case of recurrence was observed within a follow-up of six months. CONCLUSIONS: Current conventional recommendations suggest invasive treatment with Halo-Fixateur in patients with higher degrees of subluxation (e.g., Fielding type III) or after delayed diagnosis. Even in those patients, this novel therapy concept enables us to achieve excellent clinical results without surgical intervention

Cefazolin Irreversibly Inhibits Proliferation and Migration of Human Mesenchymal Stromal Cells

Drugs may have a significant effect on postoperative bone healing by reducing the function of human mesenchymal stromal cells (hMSC) or mature osteoblasts. Although cefazolin is one of the most commonly used antibiotic drugs in arthroplasty to prevent infection worldwide, there is a lack of information regarding how cefazolin affects hMSC and therefore may have an effect on early bone healing. We studied the proliferation and migration capacity of primary hMSC during cefazolin treatment at various doses for up to 3 days, as well as the reversibility of the effects during the subsequent 3 days of culture without the drug. We found a time- and dose-dependent reduction of the proliferation rate and the migratory potential. Tests of whether these effects were reversible revealed that doses ≥250 μg/mL or treatments longer than 24 h irreversibly affected the cells. We are the first to show that application of cefazolin irreversibly inhibits the potential of hMSC for migration to the trauma site and local proliferation. Cefazolin should be administered only at the required dosage and time to prevent periprosthetic infection. If long-term administration is required and delayed bone healing is present, cefazolin application must be considered as a cause of delayed bone healing

Alloplastic Reconstruction of the Extensor Mechanism after Resection of Tibial Sarcoma [Research Article]

Reconstruction of the extensor mechanism is essential for good extremity function after endoprosthetic knee replacement following tumor resection. Only a few biological methods have been able to reliably restore a functional extensor mechanism, but they are often associated with significant complication rates. Reattachment of the patellar tendon to the prosthesis using an alloplastic patellar ligament (Trevira cord) can be an appropriate alternative. In vivo and in vitro studies have already shown that complete fibrous ingrowth in polyethylene chords can be seen after a period of six months. However, until now, no biomechanical study has shown the efficacy of an alloplastic cord and its fixation device in providing sufficient stability and endurance in daily life-activity until newly formed scar tissue can take over this function. In a special test bench developed for this study, different loading regimes were applied to simulate loads during everyday life. Failure loads and failuremodes were evaluated. The properties of the cord were compared before and after physiological conditioning. It was shown that rubbing was the mode of failure under dynamic loading. Tensile forces up to 2558N did not result in material failure. Thus, using an artificial cord together with this fixation device, temporary sufficient stable fixation can be expected

Blood supply in the bicipital groove: A histological analysis

The vascular anatomy in the closed bicipital groove with the long head of the biceps brachii muscle tendon (LHBT), its mesotenon and the transverse ligament intact has not been analyzed on a histological level yet. An anatomic dissection and histologic study was conducted by using 24 cadaveric formaldehyde fixated shoulders. The bicipital groove including the LHBT and its intact sheath was cut en-bloc, fixated, sliced in 7 μm sections, Azan stained and the vascular anatomy analyzed under light microscopy. Each sideward branch deriving from the main ascending branches of the anterior humeral circumflex artery (ACHA) in the mesotenon of the LHBT was identified and followed through multiple sections to identify its direction and area of supply. Per specimen, a mean of 2.71±1.85 branches could be identified running through the soft tissue of the mesotenon towards the osseous walls of the groove. Of the total 65 arterial branches in all specimens, 22 (33.8%) were running into the medial wall of the groove and 40 (61.5%) into the lateral wall (P<0.01). The results indicate that branches of the ACHA in the mesotenon of the LHBT provide blood supply not only to the tendon but to the osseous bicipital groove as well and here significantly more to the lateral than to the medial osseous wall. In addition, Pacini-like mechanoreceptors could be identified in the mesotenon in 9 (37.5%) of the specimens which has not been described up to now

Bone marrow aspirate concentrate in combination with intravenous iloprost increases bone healing in patients with avascular necrosis of the femoral head: a matched pair analysis

With disease progression, avascular necrosis (AVN) of the femoral head may lead to a collapse of the articular surface. The exact pathophysiology of AVN remains unclear, although several conditions are known that can result in spontaneous cell death, leading to a reduction of trabecular bone and the development of AVN. Hip AVN treatment is stage-dependent in which two main stages of the disease can be distinguished: pre-collapse (ARCO 0-II) and post-collapse stage (ARCO III-IV, crescent sign). In the pre-collapse phase, core decompression (CD), with or without the addition of bone marrow (e.g. bone marrow aspirate concentrate, BMAC) or bone graft, is a common treatment alternative. In the postcollapse phase, THA (total hip arthroplasty) must be performed in most of the patients. In addition to surgical treatment, the intravenous application of Iloprost has been shown to have a curative potential and analgesic effect. From October 2009 to October 2014, 49 patients with AVN (stages I-III) were treated with core decompression at our institution. All patients were divided into group A (CD + BMAC) and group B (CD alone). Of these patients, 20 were included in a matched pair analysis. The patients were matched to age, gender, ARCO-stage, Kerboul combined necrotic angle, the cause of AVN, and whether Iloprost-therapy was performed. The Merle d’Aubigné Score and the Kerboul combined necrotic angle in a-p and lateral radiographs were evaluated pre- and postoperatively. The primary endpoint was a total hip arthroplasty. In group A, two patients needed THA while in group B four patients were treated with THA. In group A, the Merle d’Aubigné Score improved from 13.5 (pre-operatively) to 15.3 (postoperatively). In group B there was no difference between the pre- (14.3) and postoperative (14.1) assessment. The mean of the Kerboul angle showed no difference in both groups compared pre- to postoperatively (group A: pre-op 212°, postop 220°, group B: pre-op 213, postop 222°). Regarding radiographic evaluation, the interobserver variability revealed a moderate agreement between two raters regarding the pre- (ICC 0.594) and postoperative analysis (ICC 0.604).This study demonstrates that CD in combination with the application of autologous bone marrow aspirate concentrate into the femoral head seems to be a safe and efficient treatment alternative in the early stages of AVN of the femoral head when compared to CD alone

Surgical resection and radiation therapy of desmoid tumours of the extremities: results of a supra-regional tumour centre

PURPOSE: Desmoid tumours of the extremity have a high recurrence rate. The purpose of this study was to analyse the outcome after resection of these tumours with special emphasis on recurrent disease and adjuvant therapeutic strategies. METHODS: In this retrospective study we evaluated prognostic factors for recurrence-free survival after surgical treatment of desmoid tumours of the extremity in 27 patients with an average age of 41 years treated from 1997 to 2009. Adjuvant radiotherapy (50–60 Gy) was given in five cases with primary and in nine patients with recurrent disease. The average follow-up was 64 months. RESULTS: The five-year recurrence-free survival in patients with primary disease was 33 %. Patients with negative resection margins tended to have a better outcome than patients with positive resection margins, but the difference between both groups was not significant (56 vs 14 %, p = 0.145). In patients with positive margins, adjuvant radiotherapy did not significantly improve recurrence-free survival (40 vs 14 %, p = 0.523). Patients with local recurrence had a five-year further recurrence-free survival of 47 %. In those patients further recurrence-free survival was significantly better after adjuvant radiation (89 vs 25 %, p = 0.015). Two thirds of all patients suffered moderate or severe complications due to the treatment regimen. CONCLUSIONS: Compared to desmoids of the trunk or the head and neck region, desmoids affecting the limbs show by far the worst outcome in terms of relapse or treatment-related morbidity. The importance of negative resection margins is still not clear. Particularly in recurrent desmoids adjuvant radiotherapy appears to reduce the further recurrence rate. Therefore, a general use of radiation should be considered for this high-risk group

Comparison of hip joint cartilage degeneration assessed by histology and ex vivo optical coherence tomography

The aim of this study is to validate optical coherence tomography (OCT) in assessing human articular cartilage by means of histological analyses. Twenty resected human femoral head specimens were evaluated with OCT and histological analysis. OCT and histological evaluation was performed according to the Bear and the Mankin criteria. OCT grades and Mankin scores (total score and sub-score structure) were correlated and intra-/inter-observer agreement for repeated OCT evaluations was tested by interclass-correlation coefficient (ICC) analysis. OCT grades and Mankin scores were correlated [Spearman correlation = 0.742 (total) and 0.656 (structure), P&lt;0.001], revealing significant differences between the histological scores in various OCT grades of cartilage degeneration (P&lt;0.001). Intra-observer (ICC 0.930) and inter-observer (ICC 0.933) reliability was high (P&lt;0.001). OCT appears to be reliable in the assessment of human articular cartilage. Further studies on intra-operative cartilage evaluation by OCT are necessary to substantiate its applicability in clinical routine