Nanosilver/DCOIT-containing surface coating effectively and constantly reduces microbial load in emergency room surfaces

BACKGROUND

Colonization of near-patient surfaces in hospitals plays an important role as a source of healthcare-associated infections. Routine disinfection methods only result in short-term elimination of pathogens.

AIM

To investigate the efficiency of a newly developed antimicrobial coating containing nanosilver in long-term reduction of bacterial burden in hospital surfaces to close the gap between routine disinfection cycles.

METHODS

In this prospective, double-blinded trial, frequently touched surfaces of a routinely used treatment room in an emergency unit of a level-I hospital were treated with a surface coating (nanosilver/DCOIT-coated surface, NCS) containing nanosilver particles and another organic biocidal agent (4,5-dichloro-2-octyl-4-isothiazolin-3-one, DCOIT), whereas surfaces of another room were treated with a coating missing both the nanosilver- and DCOIT-containing ingredient and served as control. Bacterial contamination of the surfaces was examined using contact plates and liquid-based swabs daily for a total trial duration of 90 days. After incubation, total microbial counts and species were assessed.

FINDINGS

In a total of 2880 antimicrobial samples, a significant reduction of the overall bacterial load was observed in the NCS room (median: 0.31 cfu/cm²; interquartile range: 0.00-1.13) compared with the control coated surfaces (0.69 cfu/cm²; 0.06-2.00; P < 0.001). The nanosilver- and DCOIT-containing surface coating reduced the relative risk of a critical bacterial load (defined as >5 cfu/cm²) by 60% (odds ratio 0.38, P < 0.001). No significant difference in species distribution was detected between NCS and control group.

CONCLUSION

Nanosilver-/DCOIT-containing surface coating has shown efficiency for sustainable reduction of bacterial load of frequently touched surfaces in a clinical setting.

Transepidermal oxygen flux measurement - First clinical application for postoperative wound monitoring

BACKGROUND

Measurement of skin oxygen is of great interest in diverse fields of medicine. Different pathologies, e.g. infection, ischemia cancer or chronic wounds show a characteristic oxygen distribution and skin oxygen tension. Additionally diverse operative procedures require a reliable postoperative monitoring in order to ensure success of the therapy.

OBJECTIVE

Aim of this study was to assess transepidermal oxygen flux for postoperative wound monitoring after operative treatment of fractures close to the hip.

METHODS

22 patients underwent transepidermal oxygen flux measurement at the first postoperative day. Transepidermal oxygen flux measurement was performed using ratiometric luminescence imaging. Examination was conducted in close proximity to the operation wound. The corresponding area at the contralateral side served as reference.

RESULTS

Oxygen flux in the operation area was higher (0.084±0.021) than the contralateral side (0.071±0.029).

CONCLUSIONS

Transepidermal oxygen flux imaging by ratiometric luminescence imaging seems to be a reliable tool to assess postoperative wound healing. However further investigations in greater populations and under pathologic conditions have to be performed to prove these first results.

Timing of anterior cruciate ligament reconstruction within the first year after trauma and its influence on treatment of cartilage and meniscus pathology

PURPOSE

Anterior cruciate ligament (ACL) ruptures are often associated with primary meniscal and cartilage lesions. Late reconstruction of ACL-deficient knees may increase the risk of developing secondary meniscal and cartilage lesions; hence, the timing of ACL repair is of the utmost importance. Because meniscus outcome is also a potential predictor for osteoarthritis (OA), this study compared ACL repair within the first 6 months after injury to that of surgery conducted 7-12 months after injury with regard to the incidence of meniscal and cartilage lesions.

METHODS

This prospective cross-sectional study included all complete isolated primary ACL ruptures treated in our institution within 1 year after trauma over a 12-month period. Exclusion criteria were revision ACL, complex ligament injuries, previous knee surgery, and missing injury data. Cartilage lesions were classified according to the score established by the International Cartilage Repair Society (ICRS score) and meniscal tears according to their treatment options.

RESULTS

Two hundred and thirty-three of 730 patients (162 men, 71 women) with ACL repair met the inclusion criteria. 86.3 % of surgical interventions were conducted within 6 months and 13.7 % after 6 months of trauma. Severe cartilage lesions grade III-IV did not significantly differ between the different time points of ACL repair (<6 months 39.9 %; >6 months 31.3 %; p = n.s.). Medial meniscus lesions received significantly higher meniscal repair in early compared to delayed ACL repair. Significantly higher rate of meniscal repair of the medial meniscus was seen in cases of early ACL repair compared to delayed (<6 months 77.2 %, >6 months 46.7; p = 0.022). The rate of medial meniscal repair in early ACL repair was significantly higher for women (89.5-0 %; p = 0.002), however, not for men (73.3-53.8 %; p = n.s.). No differences were found for lateral meniscal lesions, with regard to neither the different time points (p = n.s.) nor the sex (p = n.s.).

CONCLUSIONS

Because of the significantly higher rate of prognostically advantageous meniscal repair, the recommendation for an ACL reconstruction within 6 months after trauma was made to preserve the meniscus and reduce the risk of developing OA.

LEVEL OF EVIDENCE

Prospective cross-sectional cohort study, Level II.

[School re-integration after child brain dislocation : The trauma surgeon's role]

Concussion injury of the brain is still a frequently underestimated injury, which can be associated with long-lasting consequences. Compared to adults, the recovery phase is often prolonged in childhood. Primary treatment consists of symptom-dependent physical and mental activities. Re-integration into daily life is crucial. In childhood, the primary focus is therefore on returning to school. New symptoms, or an increased presence of symptoms must be detected, to avoid prolonged recovery courses. School restrictions have to be minimized. Corresponding concepts are already implemented in North America. Comparable concepts are not established in Germany. In addition to well-known standard return-to-play protocols for sport re-integration, it is urgently recommended to integrate gradual return-to-learn protocols.Thus, academic adaptations and support must be established as well as symptom-oriented organizational and teaching modules.

Standard Approaches to the Acetabulum Part 3: Intrapelvic Approach

Introduction The intrapelvic approach was originally described by Hirvensalo et al. from Finland in the early 90ies (8) and a further comparable description was published shortly thereafter by Cole et al. (5). Since then, various modifications have been described. Whereas the ilioinguinal approach was used until then to treat acetabular fractures with relevant anterior column involvement from an extrapelvic view, the intrapelvic approach was developed to address the often accompanied central hip dislocation in these fracture types with relevant fractures of the quadrilateral surface. With this approach a complete different view to the antero-medial acetabular pathology was possible. The view from more medial allows a better direct access to joint structures "below" the pelvic brim in the true pelvis (intrapelvic) in contrast to the extrapelvic access with the ilioinguibnal approach. Meanwhile, the surgical technique has been described in detail and some modifications and tricks have been published (5, 8, 10, 13, 19). The intrapelvic approach offers several advantages compared to the ilioinguinal approach: • lower invasiveness without substantial muscle detachment, • direct view of the superior pubic rami from superior and medial, the inferior anterior column and the quadrilateral surface up to the posterior border of the posterior column at the greater sciatic notch, • reduction and fixation of the anterior column and the quadrilateral surface under direct visualization, • reduction of antero-superior marginal impactions under direct visualization, • low risk of heterotopic ossification, • low risk of lesions to the lateral cutaneous femoral nerve. The aim of the third part of "standard approaches of the acetabulum" is to report on the special topics indication, positioning, exposure, incision, dissection, the anatomical basis of osteosynthesis and present results using the via the intrapelvic approach.

Standard Approaches to the Acetabulum Part 2: Ilioinguinal Approach

The ilioinguinal approach is one of the standard approaches in the treatment of displaced acetabular fractures used during the last decades (9). The meta-analysis of Giannoudis et al. showed that 21.9% of acetabular fractures were historically treated using this approach (3). One of the disadvantages of this study was, that studies focussing especially on posterior wall stabilization and studies dealing with more complex fracture types treated by extended approaches were integrated. Thus, these fracture types were overrepresented. Re-analysis excluding these data lead to an increase of the rate of anterior approaches to 25.9%. More recent data (years 2005-2007) from the German multicenter study showed that presently in almost 45% of the cases the single ilioinguinal approach was used and only 38% of patients were stabilized via the KocherLangenbeck approach (11). Historically, the Smith-Peterson approach (15, 17) and the iliofemoral approach were used to treat acetabular fractures. In the 60ies, based on the work by Letournel and Judet, the ilioinguinal approach was developed for acetabular fracture fixation (9). It is an extrapelvic approach resulting in an indirect reconstruction concept of the acetabulum without direct visualization of the articular acetabulum. The ilioinguinal approach was the standard anterior approach during the last 30-40 years. An important advantage is the reduced soft tissue detachment of periarticular muscles with only a small risk of developing heterotopic bone formation. The aim of the second part of "Standard approaches to the acetabulum" is to report on the special topics indication, positioning, exposure, incision, dissection, the anatomical basis of osteosynthesis and present results using ilioinguinal approach.

Standard Approaches to the Acetabulum Part 1: Kocher-Langenbeck Approach

Historically, standard approaches for surgical treatment of displaced acetabular fractures were the KocherLangenbeck approach, the ilioinguinal approach and the extended iliofemoral approach (12). Presently, several modifications of these approaches are accepted alternatives, especially anterior modifications based on the intrapelvic approach described by Hirvensalo (8). Single access approaches allowing visualization of one acetabular column are the posterior Kocher-Langenbeck approach and the anterior ilioinguinal approach (12) and the use of a single approach is favoured (9, 24). For more complex situations, in the 80s and 90s extended approaches (extended iliofemoral approach according to Letournel (12), its modification to Reinert (19) (Baltimore approach), and the Triradiate approach according to Mears (14)) were introduced. These approaches are presently rarely choosen due to the extensive soft tissue dissection and higher complication rates (28). Alternatively, the combination of an anterior and posterior standard approach was recommended (7, 21, 22) having the disadvantage of longer operating time and blood loss and showed no superior results compared to a single approach. The meta-analysis by Giannoudis et al. stated that 48,7% of patients were treated using the Kocher-Langenbeck approach, followed by 21,9% ilioinguinal approaches and 12,4% extended approaches (6). More recent data from the years 2005-2007, showed that anterior approaches are now predominantly used according to a higher number of acetabular fractures with anterior column involvement. Overall, more than 40% of all patients with acetabular fractures are still approached via the Kocher-Langenbeck approach (18). Therefore, the Kocher-Langenbeck approach is still a "working horse" in approaching displaced acetabular fractures. The Kocher-Langenbeck approach consists of two parts. In 1874 von Langenbeck described a longitudinal incision starting from above the greater sciatic notch to the greater trochanter, dissecting the gluteal muscles for treating hip joint infections (11). Theodor Kocher in 1911 described a curved incision starting from the posterior-inferior corner of the greater trochanter, running across the postero-superior tip of the greater trochanter passing oblique in line with the fibres of the gluteus maximus muscle in direction to the posterior superior iliac spine (10). The aim of the present analysis is the detailed anatomi - cal analysis of this standard approach, focusing on fracture indication, positioning of the patient, exposure, dissection, reduction techniques of special fracture types, approach modifications/extensions, complications and approach-specific results.

Scaffold-cell bone engineering in a validated preclinical animal model: precursors vs differentiated cell source

The properties of osteoblasts (OBs) isolated from the axial skeleton (tOBs) differ from OBs of the orofacial skeleton (mOBs) due to the different embryological origins of the bones. The aim of the study was to assess and compare the regenerative potential of allogenic bone marrow-derived mesenchymal progenitor cells with allogenic tOBs and allogenic mOBs in combination with a mPCL-TCP scaffold in critical-sized segmental bone defects in sheep tibiae. After 6 months, the tibiae were explanted and underwent biomechanical testing, micro-computed tomography (microCT) and histological and immunohistochemical analyses. Allogenic MPCs demonstrated a trend towards a better outcome in biomechanical testing and the mean values of newly formed bone. Biomechanical, microCT and histological analysis showed no significant differences in the bone regeneration potential of tOBs and mOBs in our in vitro study, as well as in the bone regeneration potential of different cell types in vivo. Copyright © 2015 John Wiley & Sons, Ltd.

[While Others are Sleeping - Performance of Major Trauma Care at Night]

Introduction: The literature indicates that medical staff suffer from a decline in cognitive and physical performance at night. This study evaluates the process quality and outcomes of emergency care during night-time and daytime. Method: Out of 1,226 prospectively registered patients, 420 were included into this study (observation period: 76 months). Inclusion criteria were an ISS ≥ 16 and admission to trauma room during "DAY" (8 am to 4 : 49 pm) or "NIGHT" (9 pm to 5 : 59 am). The fundamental part was the 130 items of the TraumaRegister DGU. The additional 350 items contain data about prehospital treatment, trauma room management and intensive care. Data were collected by a research assistant over a 24-h period. Results: The study sample contained 268 DAY-patients and 152 NIGHT-patients. Patients admitted during night were injured more severely: ISS 34.9 (± 16.4) vs. 31.1 (± 14.2), p = 0.015 and younger: 33.3 (± 16.6) vs. 43.6 (± 22.3) years old, p < 0.001. However, this had no impact on outcome prediction scores like RISC, RISC2 or TRISS, p ≥ 0.775. Furthermore, no difference in process quality was observed like the time to gain an arterial access: NIGHT 4.5 (± 3.7) vs. DAY 5.0 (± 3.7) min, p = 0.116, time for splinting 3.8 (± 3.7) vs. 3.4 (± 3.1) min, p = 0.922, or other parameters, like time to CT: 26.9 (± 11.2) vs. 26.6 (± 14.5) min, p = 0.520. Nor was there any difference in outcome: 17.8 % of the NIGHT-patients (RISC-prognosis: 23.8 %, SMR 0.74) died in hospital, and 18.3 % of the DAY-patients (RISC-prognosis: 24.0 %, SMR 0.77), p = 0.894. As well the comparison of the Glasgow Outcome Scale revealed no difference: NIGHT 3.8 (± 1.5) vs. DAY 3.8 (± 1.6), p = 0.491. Discussion: Although evidence suggests a drop of performance by medical staff at night, this effect could not be demonstrated. Considering this, the level of process quality and outcome - regardless of the time of arrival - remained constant on a high level. These results might be attributable to the quality management and the standardisation of the treatment.

[The relevant axial deviation: Diagnostics and therapy for correction osteotomies of the femur]

Intraoperative assessment of the femoral axis, length and torsion can be difficult. A postoperative torsional discrepancy is a common but rarely diagnosed condition. A clinical evaluation of femoral torsion is limited, especially in the early postoperative period. Conventional radiographs are a reliable diagnostic tool for evaluation of discrepancies of leg length and axis. Computed tomography remains the gold standard for assessment of torsional discrepancies. Because of the wide variability of the physiological femoral torsion, the clinical impact of a torsional discrepancy in individual cases remains unclear. There is a general recommendation for revision in cases of intraindividual deviations of more than 15°; however, most patients with deviations even greater than 15° are asymptomatic. Therefore, the indications for correction should be carefully considered in each individual case. The patient level of activity is a crucial point in decision-making for correction osteotomy. Before correction osteotomy, the surgeon has to make a detailed biomechanical analysis of the leg. Early correction is recommended in most cases. Detailed knowledge of the patient medical history is needed for preoperative planning. Prior surgeries can have a significant impact on the choice of the surgical approach and stabilization technique.

Dynamic hydrostatic pressure enhances differentially the chondrogenesis of meniscal cells from the inner and outer zone

This study analyses the influence of dynamic hydrostatic pressure on chondrogenesis of human meniscus-derived fibrochondrocytes and explores the differences in chondrogenic differentiation under loading conditions between cells derived from the avascular inner zone and vascularized outer region of the meniscus. Aggregates of human fibrochondrocytes with cell origin from the inner region or with cell origin from the outer region were generated. From the two groups of either cell origin, aggregates were treated with dynamic hydrostatic pressure (1Hz for 4h; 0.55-5.03MPa, cyclic sinusoidal) from day 1 to day 7. The other aggregates served as unloaded controls. At day 0, 7, 14 and 21 aggregates were harvested for evaluation including histology, immunostaining and ELISA analysis for glycosaminoglycan (GAG) and collagen II. Loaded aggregates were found to be macroscopically larger and revealed immunohistochemically enhanced chondrogenesis compared to the corresponding controls. Loaded or non-loaded meniscal cells from the outer zone showed a higher potential and earlier onset of chondrogenesis compared to the cells from the inner part of the meniscus. This study suggests that intrinsic factors like cell properties in the different areas of the meniscus and their reaction on mechanical load might play important roles in designing Tissue Engineering strategies for meniscal repair in vivo.

Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation

Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

Posterolateral fusion in acute traumatic thoracolumbar fractures: a comparison of demineralized bone matrix and autologous bone graft

INTRODUCTION Alternative fusion expanders are in clinical use for instrumented posterolateral fusion (PLF) to avoid donor site morbidity in autologous bone graft (ABG) harvesting. Purpose of this study was to evaluate demineralized bone matrix (DBM) in PLF as alternative to the gold standard of ABG in acute traumatic vertebral body fractures of the thoracolumbar spine. MATERIAL AND METHODS We retrospectively identified 101 patients with acute traumatic vertebral body fractures of the thoracic and lumbar spine who were treated with instrumented PLF in our level one trauma center between 2005 and 2011. Patients with a primary paraplegia, osteodepriving disease or loss to follow-up had been excluded. Until August 2008, autologous bone graft harvested from the posterior iliac crest was used in PLF (control group n = 46). Starting September 2008, DBM was used as fusion expander in PLF (study group n = 16). Clinical and radiological evaluation was performed with a minimum followup of 18 months to assess the clinical and radiological outcome. RESULTS We found a fusion rate of 94% in patients undergoing PLF with the use of DBM and 100% with the use of ABG. There was one major complication of deep infection in the DBM group and two cases of superficial wound infection in the ABG group. We discovered a trend of reduced operating time with the use of DBM. CONCLUSIONS DBM leads to a similar fusion rate as the use of ABG in patients undergoing PLF for acute traumatic vertebral body fractures of the thoracic and lumbar spine. DBM is associated with reduced operating time.

LEVEL OF EVIDENCE III

case-control study Key words: demineralized bone matrix instrumented posterolateral fusion, acute traumatic vertebral body fracture, thoracolumbar spine, autologous bone graft.

[Detection of intrinsic ligament and TFCC lesions of the wrist. Direct versus indirect MRI arthrography]

BACKGROUND

The purpose of this study was to validate the diagnostic value of direct magnetic resonance imaging (dMRI) arthrography and indirect MRI (iMRI) arthrography concerning intrinsic ligament injuries and tears of the triangular fibrocartilage complex (TFCC).

PATIENTS AND METHODS

A randomized prospective trial was conducted with patients who presented with wrist pain potentially due to carpal lesions and 10 patients aged 19-60 years (3 female and 7 male) were included. Between the clinical examination and the diagnostic and therapeutic arthroscopy, dMRI and iMRI arthrography were performed for the diagnostics of injuries of the intrinsic ligaments or the TFCC. The results of dMRI and iMRI arthrography were evaluated by two radiologists blinded to the injuries of the patients and a consensus was reached. The results were compared with the findings obtained by arthroscopy.

RESULTS

In the arthroscopy five lesions of the scapholunate ligament (SL), one of the lunotriquetral ligament (LT) and seven of the TFCC were identified. The sensitivity of iMRI and dMRI for carpal ligament lesions (SL and LT) was low (50 %) whereas the specificity was high (93 %). For injuries of the TFCC the sensitivity (up to 100 %) and the specificity (100 %) were both excellent. The area under the curve (AUC) in the receiver operating characteristics (ROC) analysis was high for TFCC lesions in both dMRI and iMRI arthrography.

CONCLUSION

Indirect MRI arthrography is a suitable method for detection of injuries of the TFCC and intrinsic ligaments of the wrist with good sensitivity and specificity. Despite the low number of patients the results of this study showed that there were no essential differences between dMRI and iMRI arthrography with respect to the diagnostic value for carpal injuries of the wrist.

Indications for bullet removal: overview of the literature, and clinical practice guidelines for European trauma surgeons

PURPOSE

The incidence of gunshot wounds from civilian firearms is increasing. Despite this fact, guidelines on indications for bullet removal are scarce. In this analysis, we combine an overview of the available literature in these rare entities with our experiences in our own clinical practices.

METHODS

We conducted a systematic literature search of computerized bibliographic databases (Medline, EMBASE, and the Cochrane Central Register). The local experience of the authors was reviewed in light of the available literature.

RESULTS

145 full-text articles were suitable for further evaluation. Only six retrospective studies were available, and no prospective study could be retrieved. Most of the articles were case reports. In the South African co-author's own clinical practice, approximately 800 patients are treated per year with gunshot wounds.

CONCLUSIONS

In summary, there are only a few clear indications for bullet removal. These include bullets found in joints, CSF, or the globe of the eye. Fragments leading to impingement on a nerve or a nerve root, and bullets lying within the lumen of a vessel, resulting in a risk of ischemia or embolization, should be removed. Rare indications are lead poisoning caused by a fragment, and removal that is required for a medico-legal examination. In all other cases the indication should be critically reviewed.

Resazurin dye as a reliable tool for determination of cell number and viability in mesenchymal stem cell culture

Human mesenchymal stem cells are a valuable cell source for tissue engineering. Determination of cell number and viability is crucial. However, this can be tested only at the end of cell culture. This study shows that Resazurin dye staining is a reliable tool for evaluation of cell number and viability in culture without cell perturbation.

[Quality circle in a trauma network of the German Association for Trauma Surgery. Upgrading patient care]

In industry, especially in the automobile industry, improvements in efficiency could be demonstrated by quality management and quality circles. There is no doubt that in medicine, major trauma is also a very complex challenge.The German Association for Trauma Surgery published the White Paper on the Management of the Seriously Injured in 2006. The White Paper specifies the demand for quality of care, sets the level of structural requirements for trauma care and postulates the cooperation of regional hospitals within a network of dedicated trauma centres. The Trauma Network Eastern Bavaria (TNO) was the first certified trauma network in Germany. One of the reasons for this success is the fact that cooperation between trauma surgeons has already had a long tradition in this geographic area. The key factor is communication which is supported by all technical and organisational means. The formal installation of quality circles on each level of trauma care, e.g. within and across institutions, was accepted by all partners within the network. The goal is the improvement of patient care in trauma above and beyond the guidelines of the White Paper. This paper shows the instruments used to enhance the quality of trauma care within a network.

Tibial pilon fractures

Tibial pilon fractures are severe injuries to the distal articular surface of the tibia. Such injuries frequently result from high-energy axial impact and are often associated with extended soft tissue injury. Various treatment methods are available, depending not only on the fracture type but mostly on the extent of the soft tissue injury; one of the most frequent procedures is a two-stage surgery: the initial closed reduction of the fracture via primary placement of an ankle joint-spanning external fixator, if possible in conjunction with open reduction and internal fixation of the fractured fibula followed by a secondary procedure after soft tissue recovery by open reduction and internal fixation of the tibial plafond. By now, new types of low-profile and locking plates are available for internal fixation allowing the anatomical reconstruction of the fractured articular surface while sparing the soft tissue. Nonetheless, the treatment of tibial pilon fractures is technically demanding because of their potential for severe complications.

[Sports and activities after achilles tendon injury of the recreational athlete]

BACKGROUND

There is abundant literature on the treatment of Achilles tendon rupture; however data on sports and recreational activities after this injury is scarce.

PATIENTS AND METHODS

71 patients were assessed in a prospective cross-sectional study after an average of 3 years after Achilles tendon rupture. 44 patients were treated non-operatively, using a functional algorithm, and 23 patients were treated operatively. Outcome parameters were the AOFAS-Score and the SF-36 Score. The strength of plantar-flexion was measured using the Isomed 2000 system, the structural integrity of the tendon was assessed sonografically.

RESULTS

Patients treated operatively had a higher complication rate than patients treated non-operatively (p = 0.05). Re-rupture rate was identically in both groups. No difference was noted between the two groups for the AOFAS score (92 vs. 90). Moreover the SF-36 score did not show any significant difference between the groups. However, if compared to the age-adjusted normative population significant lower scores were achieved. A significant reduction in practicing sports was detected, as well as a reduction of plantar flexion of the affected foot (p = 0.04).

CONCLUSION

Except for complication rate no significant difference could be detected between the groups. Thus operative treatment in the recreational athlete should only be considered, if no adaptation of the ends of the tendon is diagnosed during the initial or repeated ultrasound. Regardless of the therapeutic intervention chosen an Achilles tendon rupture leads to marked changes in sports- and recreational activities.

[Realization and implementation of a trauma network of the German Association of Trauma Surgery (DGU) exemplified by the Trauma Network of eastern Bavaria]

The quality of care of seriously injured persons in Germany is nationally and internationally recognized to be at a high level. However, there are local discrepancies. In 2006 the German Association of Trauma Surgery published the White Paper for the Management of the Seriously Injured. The goal of the paper is a further increase in the quality of care of seriously injured persons. A crucial point of the publication is the call to establish regional trauma networks in Germany. Work on this project has been carried out in eastern Bavaria since spring 2007. The first meeting of the Trauma Network of eastern Bavaria took place in July 2007. On 3rd September 2008 the university hospital of Regensburg was the first clinic audited in Germany. To date nearly 75% of all hospitals in the trauma network of eastern Bavaria have been audited. The establishment of a regional trauma network is a multifactorial event. Essential factors in the development of the trauma network were found to be the communication between the head physicians and the nomination of an appointee of the regional trauma network. For the head physicians the 9 meetings of the trauma network since July 2007 functioned as the communication platform. These exchanges of the head physicians are necessary to animate a trauma network. The appointee of the regional trauma network--most suitably a member of staff of the speaker of the trauma network--is essential to guarantee communication between meetings and to manage prompt responses to questions from the network. This article describes the experiences gained during the implementation of the trauma network in eastern Bavaria.

[Treatment of lower limb osteomyelitis by a local bone substitute supplemented with antibiotics]

A seriously injured tsunami victim with complicated osteomyelitis is presented. The patient was treated with a new resorbable bone substitute, which can be loaded with different antibiotics. The successful treatment is illustrated by the clinical, radiological and histological features. Bilateral open fractures of the lower leg with open elbow fracture led to a bilateral amputation of the lower legs and the right arm because of a beginning sepsis. The following intramedullary osteitis with multiresistant Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecium was treated with the bone substitute PerOssal combined with systemic and local application of vancomycin and systemic application of ceftazidime and meropenem. This case report illustrates the concept of an additional local antibiotic treatment of osteomyelitis by a bone substitute also functioning as a drug delivery system.

Evaluation of microcirculation of free flaps of the lower leg by contrast harmonic imaging (CHI) with time intensity curve (TIC) analysis

PURPOSE

The aim of the prospective study was to evaluate the macro- and microcirculation in the center and periphery of free flaps with high resolution vascular ultrasound.

MATERIAL

Fifteen patients with free parascapular flaps after lower limb trauma were examined six months postoperative. All ultrasound investigations were performed by one experienced examiner with a multi-frequency linear transducer (5-9 MHz, Logiq 9, GE). Flow evaluation was angle-optimized using digital image technology with the color coded Doppler sonography (CCDS) with measurement of the peak systolic, peak diastolic flow velocities and the resistance index (RI). Contrast harmonic imaging (CHI) with time intensity curve (TIC) analysis was used for quantitative evaluation of the tissue perfusion. Through a peripheral cubital cannula, a first bolus injection was made of 2.4 ml Sonovue to evaluate the perfusion near the flap center and the distal part of the flap.

RESULTS

The combined analysis of all 15 patients showed in the center and in the periphery of the flap a significant increase (p<0.01; Wilcoxon signed rank test) of the perfusion (relative units = RUs) in the period of 90-120 s after contrast medium application (center: baseline perfusion 2.23+/-0.31 RUs to 5.25+/-0.90 RUs after contrast medium; periphery: baseline perfusion 3.07+/-0.44 RUs to 5.80+/-0.57 RUs after contrast medium). The separate analysis of the non-bypass group (n=9) and bypass group (n=6) showed a clearly higher central flap perfusion after contrast medium application for the bypass group. The combined analysis of all patients showed RI-values amounting to 0.79+/-0.03. The RI-values of the bypass group were significantly higher than RI-values of the non-bypass group (p<0.05; t-test; p<0.05; Mann-Whitney rank sum test).

CONCLUSION

The high-resolution ultrasound represents an ideal method for detection of the flow and patency of the bypass and the small vessels of the free flap. The patency of microvascular anastomosis as well as the perfusion and microcirculation in different flap territories and tissue layers can be investigated using dynamic contrast-enhanced ultrasound with subtraction modalities.

Osteo-fasciocutaneous parascapular flap transfer for reconstruction of the first ray of the foot

BACKGROUND

Severe bone and soft tissue defects of the first metatarsal bone after trauma, tumor resection or osteomyelitis are challenging to treat. Partial amputation of the foot may be the consequence. However, due to its significance for gait, salvage of the first ray should be considered, whenever possible. One option for bone and soft tissue reconstruction, therefore, might be an osteo-fasciocutaneous parascapular flap transfer.

METHODS

Five patients with bone and soft tissue defects of the first ray of the foot but intact MTP joint were treated with osteo- fasciocutaneous parascapular flap transfer, two after tumor resection, and three after severe bone and soft tissue trauma. Patients were followed for 12-36 months clinically and radiologically.

RESULTS

All flaps survived. One revision was necessary because of venous thrombosis, which was treated successfully by thrombectomy and patch plastic. All osteosyntheses united and the scapular bone transplant adapted nicely to the new loading conditions. All patients were content with the result and would agree to have the operation again. Two patients were able to stand tiptoe and go jogging, one patient still had limitations of ADLs due to the concomitant injuries.

CONCLUSION

The osteo- fasciocutaneous flap proved to be very versatile and safe for foot reconstruction due to its favorable vascular anatomy. In all patients (partial), amputation of the foot could be avoided.

A safe and simple technique using the distal pedicled reversed upper arm flap to cover large elbow defects

The reconstruction of large soft-tissue defects at the elbow is hard to achieve by conventional techniques and is complicated by the difficulty of transferring sufficient tissue with adequate elasticity and sensate skin. Surgical treatment should permit early mobilisation to avoid permanent functional impairment. Clinical experience with the distal pedicled reversed upper arm flap in 10 patients suffering from large elbow defects is presented (seven male, three female; age 40-70 years). The patient sample included six patients with chronic ulcer, two with tissue defects due to excision of a histiocytoma, and one patient with burn contracture. In the two cases of histiocytoma, defect closure of the elbow's ulnar area was achieved by using a recurrent medial upper arm flap. In the eight other patients we used a flap from the lateral upper arm with a flap rotation of 180 degrees. Average wound size ranged from 4 to 10 cm, average wound area from 30 to 80 cm(2). Flap dimensions ranged from 15 x 8 cm for the lateral upper arm flap to 29 x 8 cm for the medial upper arm flap. The inferior posterior radial and ulnar collateral arteries are the major nutrient vessels of the reversed lateral and medial upper arm flaps. Perforating vessels are identified preoperatively using colour Doppler ultrasonography. Flap failure did not occur. Secondary wound closure became necessary due to initial wound healing difficulties in one patient. Mean operation time was 1.5 h and mean follow-up period 12 months. Good defect coverage with tension-free wound closure was achieved in all cases. Stable defect coverage led to long-term wound stability without any restriction of elbow movement. The lateral and medial upper arm flaps represent a safe and reliable surgical treatment option for large elbow defects. The surgical technique is comparatively simple and quick.

Contrast harmonic ultrasound and indocyanine-green fluorescence video angiography for evaluation of dermal and subdermal microcirculation in free parascapular flaps

PURPOSE

Contrast harmonic ultrasound (CHI) with a linear transducer is a new diagnostic approach that allows dynamic and quantitative flow detection of tissue perfusion in microsurgery. The aim of the study was the evaluation of perfusion of the dermal and subdermal layers of microvascular tissue transplants with CHI in comparison to ICG-fluorescence angiography.

MATERIAL AND METHOD

In a prospective clinical study indocyanine-green fluorescence video angiography and contrast enhanced high resolution ultrasound (5-10 MHz; linear transducer; Logiq 9; GE) were used for evaluation of the microcirculation in 10 transplanted free parascapular flaps. Two regions were analysed, the centre of the flap and the region of the anastomosis. The perfusion patterns of both methods were compared.

RESULTS

The perfusion indexes measured by ICG-fluorescence angiography correlated very precisely in all patients with the quantitative perfusion curves of contrast-enhanced US with CHI. Two flaps with slow filling and low dye intensity showed low contrast enhancement in CHI with modified perfusion curves with slow increase. In two cases a reduced perfusion and filling were found. There were no statistical differences between the two diagnostic methods (p>0.01).

CONCLUSION

CHI improves US detections of dermal and subdermal microcirculation in comparison to ICG fluorescence angiography. CHI is a new diagnostic method for postoperative monitoring of free flaps.

Transcutaneous pO2 measurement during tourniquet-induced venous occlusion using dynamic phosphorescence imaging

A sufficient oxygen supply in skin grafts requires a functioning microcirculation. Venous occlusion impairs the microcirculation and is therefore a major threat of healing. Luminescence life time imaging (LLI) enables the non-invasive and two-dimensional assessment of the transcutaneous oxygen partial pressure (p(tc)O2). In the current trial this new device was applied for monitoring of venous congestion. A tourniquet on the upper arm was inflated up to 40-50 mmHg and released after 10 min in eight healthy volunteers. The p(tc)O2 was measured at the lower arm every minute prior to, during and up to 10 min after cuff occlusion (40 degrees C applied skin temperature) using LLI of platinum(II)-octaethyl-porphyrin immobilized in a polystyrene matrix. For validation the polarographic Clark electrode technique was applied in close proximity and measurement was performed simultaneously. p(tc)O2 measurements prior to (Clark: 50.68+/-5.69 mmHg vs. LLI: 50.89+/-4.96 mmHg) and at the end of the venous congestion (Clark: 16.41+/-4.54 mmHg vs. LLI: 23.82+/-3.23 mmHg) did not differ significantly using the Clark electrode vs. LLI. At the initial congestion respectively reperfusion phase the Clark electrode measured faster decreases respectively increase of p(tc)O2 due to oxygen consumption of this method. This experimental trial demonstrates the applicability of LLI to quantify the p(tc)O2 under changing venous blood flow. The use of planar transparent sensors allows the non-invasive generation of two-dimensional maps of surface pO2 what makes this method particular suitable for monitoring of skin grafts.

Contrast harmonic ultrasound and indocyanine-green fluorescence video angiography for evaluation of dermal and subdermal microcirculation in free parascapular flaps

PURPOSE

Contrast harmonic ultrasound (CHI) with a linear transducer is a new diagnostic approach that allows dynamic and quantitative flow detection of tissue perfusion in microsurgery. The aim of the study was the evaluation of perfusion of the dermal and subdermal layers of microvascular tissue transplants with CHI in comparison to ICG-fluorescence angiography.

MATERIAL AND METHOD

In a prospective clinical study Indocyanine-Green Fluorescence Video Angiography and Contrast Enhanced High Resolution Ultrasound (5-10 MHz; linear transducer; Logiq 9; GE) were used for evaluation of the microcirculation in 10 transplanted free parascapular flaps. Two regions were analysed, the centre of the flap and the region of the anastomosis. The perfusion patterns of both methods were compared.

RESULTS

The perfusion indexes measured by ICG-fluorescence angiography correlated very precisely in all patients with the quantitative perfusion curves of contrast-enhanced US with CHI. Two flaps with slow filling and low dye intensity showed low contrast enhancement in CHI with modified perfusion curves with slow increase. In two cases a reduced perfusion and filling were found. There were no statistical differences between the two diagnostic methods (p>0.01).

CONCLUSION

CHI improves US detections of dermal and subdermal microcirculation in comparison to ICG fluorescence angiography. CHI is a new diagnostic method for postoperative monitoring of free flaps.

Evaluation of the vascular integrity of free flaps based on microcirculation imaging techniques

BACKGROUND

A free-flap graft refers to the free transfer of tissue to cover tissue defects caused by trauma or malperfusion in plastic surgery. The basic principle, which makes a free flap working is an adequate blood flow. We applied new techniques which are able to detect the blood flow of the anastomosis and of dermal and subdermal tissue layers in a reliable way.

METHODS

To this end we applied innovative Ultrasound-techniques (contrast enhanced high resolution Ultrasound (US), color coded Doppler sonography (CCDS), Cross Beamtrade mark, Power Doppler, Tissue Harmonic Imagingtrade mark (THI), Speckle Reduction Imagingtrade mark (SRI)), as well as the Indocyanine Green (ICG) fluorescence angiography to evaluate the vascular integrity of 15 parascapular flaps implanted to the fore foot over a period of four years. The age of the subjects ranged from 16 to 60 years. The US machine (GE Logiq 9) was equipped with a Logiq 9L transducer (6-9 MHz) and the modalities of CHI (Contrast Harmonic Imaging) and True Agent Detection (dual view of B-Mode and contrast mode).

RESULTS

The borders of the investigated flaps could be best detected using Cross Beamtrade mark Technology with SRItrade mark and THItrade mark. Power Doppler was able to detect anastomotic vessels even if they were twisted or elongated. Reduced perfusion curves were seen in cases with low anastomotic flow in CCDS. The CHItrade mark allowed dynamic flow detection of the microcirculation of the tissue graft over a depth of up to 3 cm including quantitative perfusion curves of tissue microcirculation by using TICtrade mark analysis. There is a strong correlation between the perfusion indices measured by ICG fluorescence angiography and CHItrade mark. Furthermore the ICG showed a remarkable enhancement of fluorescence in the flap borders, which need to be explored in future investigations.

CONCLUSION

These new applications provide useful and effective methods for improved postoperative monitoring of free flaps in plastic surgery and can lead to substantial reduction in the overall risk of flap failure.

Proximal humerus fractures: a comparative biomechanical analysis of intra and extramedullary implants

INTRODUCTION

The biomechanical stability of a newly developed humerus nail (Sirustrade mark) for the treatment of fractures of the proximal humerus was analyzed in comparison to established systems. In total, three randomized groups were formed (n = 4 pairs) from 12 matched pairs of human cadaver humeri.

MATERIALS AND METHODS

All intact bones were mechanically characterized by five subsequent load cycles under bending and torsional loading. The bending moment at the osteotomy was 7.5 N m the torsional moment was 8.3 N m over the hole specimen length. Loading was consistently initiated at the distal epiphysis and the deformation at the distal epiphysis was continuously recorded. Prior to implant reinforcement, a defect of 5 mm was created to simulate an unstable subcapital humerus fracture. For paired comparison, one humerus of each pair was stabilized with the Sirus proximal humerus nail while the counterpart was stabilized by a reference implant. In detail, the following groups were created: Sirus versus Proximal humerus nail (PHN) with spiral blade (group I); Sirus versus PHILOS plate (group II); Sirus versus 4.5 mm AO T-plate (group III).

RESULTS

The Sirus nail demonstrated significantly higher stiffness values compared to the reference implants for both bending and torsional loading. The following distal epiphyseal displacements were recorded for a bending moment of 7.5 N m at the osteotomy: Sirus I: 8.8 mm, II: 8.4 mm, III: 7.7 mm (range 6.9-10.9), PHN 21.1 mm (range 15.7-25.2) (P = 0.005), PHILOS plate 27.5 mm (range 21.6-35.8) (P < 0.001), 4.5 AO T-plate 26.3 mm (range 24.3-33.9) (P = 0.01). The rotations corresponding to 8.3 N m torsional moment were: Sirus I: 9.1 degrees , II: 9.3 degrees , III: 10.6 degrees (range 7.5-12.2), PHN 13.5 degrees (range 10.3-15.6) (P = 0.158), PHILOS plate 15.6 degrees (range 13.7-20.8) (P = 0.007), 4.5 AO T-Platte 14.1 degrees (range 11.5-19.7) (P = 0.158).

CONCLUSION

The intramedullary load carriers were biomechanically superior when compared to the plating systems in the fracture model presented here. Supplementary, the Sirus Nail showed higher stiffness values than the PHN. However, the latter are gaining in importance due to the possibility of minimal invasive implantation. Whether this will be associated with functional advantages requires further clinical investigation.

Konduktives Knochenersatzmaterial mit variabler Antibiotikaversetzung

BACKGROUND

A new bone substitute, consisting of hydroxylapatite and calcium sulphate, was prepared in two formulations and analysed for its mechanical strength and antibiotic elution.

MATERIAL AND METHODS

The bone substitute PerOssal has osteoconductive and degradable properties. The material has a built-in capillary structure, which results in an immediate fluid uptake. Antibiotics absorbed to the bone substitute resulted in a prolonged release rate. Mechanical strength was investigated by an unconfined compression test up to failure under both wet and dry conditions for both formulations of the bone substitute. Antibiotic release was analysed microbiologically for two antibiotics, vancomycin and gentamicin, over an elution period of 10 days using the agar diffusion method.

RESULTS

The drug release analysis resulted in a prolonged release rate of both antibiotics over 10 days. In vitro the amount of gentamicin and vancomycin eluted at day 10. From one pellet still exceeded the minimal inhibitory concentration of most aetiologically important pathogens. Formulation two of the present bone substitute is significantly harder in both wet and dry conditions when compared to formulation one. Both formulations lose strength in the wet condition relative to their performance in the dry condition. However, formulation two is as hard under wet conditions as formulation one is when dry.

CONCLUSION

PerOssal is a suitable new degradable osteoconductive bone substitute that can be loaded with antibiotic solutions, which are released in effective doses over 10 days. The mechanical strength of PerOssal is sufficient to support cancellous bone defects in non-weight-bearing areas or in combination with osteosynthesis.

Value of high resolution ultrasound and contrast enhanced US pulse inversion imaging for the evaluation of the vascular integrity of free-flap grafts

OBJECTIVE

The aim of this study was to evaluate the clinical value of color coded Doppler sonography (CCDS) and contrast-enhanced harmonic imaging (CHI) for ultrasound (US) monitoring the integrity of free-flap vascular grafts. Patency of microvascular anastomoses and perfusion as well as microcirculation of the transplanted tissue were analysed.

PATIENTS AND METHODS

Fifteen free parascapular flap grafts performed over a period of three years by a single surgeon were examined with CCDS and CHI. The patients (12 male, 3 female) ranged in age from 16 to 60 years (average age 40+/-12). The follow-up period ranged from two weeks to 2.5 years. CCDS were performed with a multifrequency linear transducer (5-10 MHz, Logiq 9, GE) with 3D flow detection. For detection and characterization, B scan of the flap tissue was compared to tissue harmonic imaging (THI) and Cross Beam with Speckle Reduction Imaging (SRI). US Pulse Inversion Harmonic Imaging (PIHI) after bolus injection of 2.5 ml Sonovue was used for contrast enhancement.

RESULTS

Border and tissue structure of the flaps could be detected best in all 15/15 cases using Cross Beam Technology with SRI and THI. Correlations were found for flow parameters of the common femoral artery, popliteal artery and lower leg artery to the anastomotic vessels. 3D imaging with CCDS facilitated flow detection of elongated and small anastomotic vessels in 4/15 cases. Contrast-enhanced US with PIHI allowed dynamic flow detection of the microcirculation of the transplanted tissue over a depth of up to 3 cm with quantitative perfusion curves of the tissue microcirculation. Reduced US contrast enhancement with modified perfusion curves was seen in 2/15 cases with low anastomic flow in CCDS.

CONCLUSION

Assessment of microvascular perfusion with contrast-enhanced ultrasound can provide valuable information on free flap viability. Contrast-enhanced US enables dynamic and quantitative flow detection of free flap tissue.

Treatment of human mesenchymal stem cells with pulsed low intensity ultrasound enhances the chondrogenic phenotype in vitro

This study examined the effects of low intensity pulsed ultrasound (LIPUS) on human bone marrow-derived mesenchymal stem cells undergoing chondrogenic differentiation. Aggregates of mesenchymal stem cells and mesenchymal stem cells seeded in three dimensional matrices were cultured in a defined chondrogenic medium and subjected to LIPUS for the first 7 days of culture. At 1, 7, 14 and 21 days, samples were harvested for histology, immunohistochemistry, RT-PCR, and quantitative DNA and matrix macromolecule analysis. Cell aggregates with daily treatment for 20 minutes showed no significant differences for proteoglycan and collagen content during chondrogenic differentiation. However ultrasound application for 40 minutes daily resulted in a statistically significant increase of the proteoglycan and collagen content after 21 days in culture. Aggregates treated for 20 minutes daily showed decreased expression of chondrogenic genes at all time points. In contrast, 40 minutes of daily treatment of aggregates resulted in a significant increase of chondrogenic marker genes after an initial decrease at day 7 with time in culture. Ultrasound treated cell-scaffold constructs showed a significant increase of chondrogenic marker gene expression and extracellular matrix deposition. This study indicates that LIPUS can be used to enhance the chondrogenesis of mesenchymal stem cells in cell aggregates and cell-scaffold constructs. We have found a dependency on the specific treatment parameters. We hypothesize that LIPUS can be used for an improved in vitro preparation of optimized tissue engineering implants for cartilage repair. Furthermore this non-invasive method could also be of potential use in vivo for regenerative therapy of cartilage in the future.

[Training in sports medicine for medical students--Evaluation of a practice-oriented teaching concept]

INTRODUCTION

Education in Sports Medicine is offered heterogeneously in German medical schools. Efficacy and acceptance among medical students are unknown. The self-image of sports has changed from a traditional, competition-oriented way to adventure, entertainment, wellness and health. Therefore changes of our curricula to a practical oriented way of teaching are required. In this regard a new curriculum was developed. The main focus, besides an interdisciplinary class in sports medicine was to offer practical education in sports to the students.

METHODS

Efficacy and acceptance of the class were evaluated using a questionnaire. 90 medical students (58 male, 32 female) were included into the study .

RESULTS

The interdisciplinary topics of the class were graded positively. Most of the presentations were regarded as very useful for the future practice. Empathy and commitment of the professor were keystones to good scores. The "fun-factor" was the key for the success of the practical assignment. Practical training was regarded as fundamental for a sports medicine class.

DISCUSSION

Evaluation of the new concept as well as a discussion of the current practice to teach sports medicine at medical school confirm the need of a more practical oriented education, in order to meet the requirements of sports medicine in a time with changing self image of sports.

[Reduction of the amputation rate in bone and soft tissue sarcoma by interdisciplinary cooperation]

On the basis of three patients with bone and soft tissue sarcoma,we would like to illustrate the necessity of a well working inter-disciplinary cooperation of radiologists, internal oncologists, radiation therapists, orthopaedic surgeons and plastic surgeons. Functional extremity preservation in sarcoma patients can be achieved by a good interdisciplinary management without im-pairing the total prognosis of the patients. Patients with sarcoma should be treated in centres in which all specialised divisions are experienced and well trained in the treatment of tumour patients. Only then can a promising approach be achieved.

[Ambulation training with bilateral limited weight bearing after foot injuries]

AIM

Bilateral foot injuries are not uncommon. Operative treatment usually requires partial weight bearing over several weeks. This is a challenge for physiotherapy especially for ambulation training. We describe a new rehabilitation aid allowing for bilateral limited weight bearing during ambulation.

METHODS

Ambulation training was initiated in the early postoperative period using the Regensburg ambulation aid. A lift system allows for exact limitation of weight bearing on both sides controlled by balances integrated into the floor. Using a rail system a 15 m free walking distance is available. This study included 10 patients with bilateral foot fractures. The functional outcome was assessed using the AOFAS score and quality of life with the SF-36 score. Plain X-rays were used to evaluate loss of correction. The control group consisted of 20 patients where ambulation training was discontinued for at least 6 weeks postoperatively.

RESULTS

The system is very safe, during the entire period no complication was recorded. Acceptance among the patients was extremely high. Worries about unwanted weight bearing could be reduced. Patients mobilized with early ambulation training showed a better compensation of gait if compared to the control group. Secondary problems in the knee, hip or spine, as well as muscular deficiencies had a significantly lower incidence. No loss of correction could be seen in either of the two groups.

CONCLUSION

The presented ambulation aid is a significant contribution to the physiotherapy of bilateral foot injuries.

Mechanobiological conditioning of stem cells for cartilage tissue engineering

Articular cartilage possesses little capacity for endogenous repair after having been damaged by disease or trauma. Various surgical procedures depending on ingrowth of mesenchymal stem cells into the defects showed repair with fibrocartilage which is of minor quality and less resistant against physical forces. New treatment options using Tissue Engineering strategies for cartilage repair showed intriguing results. Human mesenchymal stem cells (MSC) isolated from bone marrow are becoming increasingly recognized for their potential to generate different cell types and thereby function effectively in vitro or in vivo in tissue repair. Incorporation of MSCs in suitable tissue engineering scaffolds and culture in chondrogenic medium can produce cartilage-like tissue. MSCs can be harvested from bone marrow by a small puncture of the iliac crest of patients. In contrast to chondral based repair this small procedure creates no additional harvest defect in the knee joints of the patient. Numerous publications show the beneficial influence of mechanobiological conditioning (e.g. mechanical compression, hydrostatic pressure, osmotic, shear, ultrasound) on the chondrogenic differentiation of dedifferentiated chondrocytes. In contrast to chondrocytes and cartilage explants there are few studies that examine the influence of mechanobiological stress on mesenchymal progenitor cells undergoing chondrogenesis. Using an in vitro aggregate culture system enhanced chondrogenesis of mesenchymal progenitor cells, detected by an increased extracellular matrix deposition of collagen and aggrecan, could be shown under repeated cyclic hydrostatic pressure. Similar results, with an increase in chondrogenic differentiation of mesenchymal progenitor cells could be detected, when the cells were loaded in three-dimensional matrices and subjected to cyclic, compressive load or low-intensity pulsed ultrasound. This review will summarize the current state of knowledge in the field of mechanobiological conditioning of mesenchymal stem cells and its possible clinical application.