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Aims The management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. The correct antibiotic management remains elusive due to differences in epidemiology and resistance between countries, and reports in the literature. Before the efficacy of surgical treatment is investigated, it is crucial to analyze the bacterial strains causing PJI, especially for patients in whom no organisms are grown. Methods A review of all revision TKAs which were undertaken between 2006 and 2018 in a tertiary referral centre was performed, including all those meeting the consensus criteria for PJI, in which organisms were identified. Using a cluster analysis, three chronological time periods were created. We then evaluated the antibiotic resistance of the identified bacteria between these three clusters and the effectiveness of our antibiotic regime. Results We identified 129 PJIs with 161 culture identified bacteria in 97 patients. Coagulase-negative staphylococci (CNS) were identified in 46.6% cultures, followed by Staphylococcus aureus in 19.8%. The overall resistance to antibiotics did not increase significantly during the study period (p = 0.454). However, CNS resistance to teicoplanin (p < 0.001), fosfomycin (p = 0.016), and tetracycline (p = 0.014) increased significantly. Vancomycin had an 84.4% overall sensitivity and 100% CNS sensitivity and was the most effective agent. Conclusion Although we were unable to show an overall increase in antibiotic resistance in organisms that cause PJI after TKA during the study period, this was not true for CNS. It is concerning that resistance of CNS to new antibiotics, but not vancomycin, has increased in a little more than a decade. Our findings suggest that referral centres should continuously monitor their bacteriological analyses, as these have significant implications for prophylactic treatment in both primary arthroplasty and revision arthroplasty for PJI. Cite this article: Bone Joint J 2021;103-B(6 Supple A):171–176.

Parents whose children are affected by systemic diseases, anomalies, deformities, or further orthopedic defective positions use the Internet to increase their knowledge. However, there have been few studies that focus, as this one does, on Internet enquiries done before the parents contact the pediatric orthopedic surgeon. This study analyzed data gathered through a standardized questionnaire on general habits of Internet use, parents' hardware, age, and educational background of the parents. A total of 521 questionnaires were completed for a response rate of 96%. One-quarter of parents (n = 127) attended the consultation because of a gait anomaly or foot deformity, followed by children with DDH (20%, n = 99), clubfoot (9%, n = 47), and scoliosis (6%, n = 29). Parents of children with clubfoot were especially likely to look for health information online (84%, n = 38), followed by parents of children with scoliosis (69%, n = 20), with DDH (67%, n = 66), and with foot deformity/gait anomaly (49%, n = 62). Most people (97%, n = 295) using the Internet for health research purposes made use of a search engine. Concerning use of social media, respondents with clubfoot children were the most numerous (38%, n = 18). There were 35 parents who intended to discuss the results of their Internet research with the pediatric orthopedic surgeon. Most (84%, n = 254) of the respondents who used the Internet for health research planned to do so again.Conclusion: This study documented that the Internet is an important and popular source of information for parents or caregivers in the field of pediatric orthopedics.Level of evidence: Level II; prospective study What is known: •Parents and caregivers often search the Internet for information, particularly before an upcoming operation in the field of orthopedic disorders. What is new: •This study provides recent data on parental Internet research in a large study population.

Femoral component malrotation in total knee arthroplasty (TKA) is clinically proven to cause dissatisfaction and impaired function. This study is an attempt to characterize the tibiofemoral kinematics following femoral malrotation in posterior stabilized (PS) TKA. It was hypothesized that internal malrotation would introduce the most pronounced changes. Six fresh-frozen cadaver specimens were mounted in a kinematic rig. Three motion patterns were applied with the native knee and following PS TKA (passive motion, open chain extension, and squatting) while infrared cameras recorded the trajectories of markers attached to femur and tibia. Three different femoral implants were tested: a conventional posterior stabilized component, and adapted components of the same implant with 5° of intrinsic external and internal rotation, respectively. The implantation of the PS TKA resulted in less tibial internal rotation (squat 33–70°, p

Fixed-bearing unicompartmental knee arthroplasty (UKA) closely replicates native knee kinematics. As few studies have assessed kinematics following mobile-bearing (MB) UKA, the current study aimed to investigate whether MB UKA preserves natural knee kinematics. Seven fresh-frozen full-leg cadaver specimens were prepared and mounted in a kinematic rig that allowed all degrees of freedom at the knee. Three motion patterns, passive flexion–extension (0°–110° flexion), open-chain extension (5°–70° flexion) and squatting (30°–100° flexion), were performed pre- and post-implantation of a medial MB UKA and compared in terms of rotational and translational knee joint kinematics in the different anatomical planes, respectively. In terms of frontal plane rotational kinematics, MB UKA specimens were in a more valgus orientation for all motion patterns. In the axial plane, internal rotation of the tibia before and after UKA was consistent, regardless of motion task, with no significant differences. In terms of frontal plane, i.e., inferior–superior, translations, the FMCC was significantly higher in UKA knees in all flexion angles and motor tasks, except in early flexion during passive motion. In terms of axial plane, i.e., anteroposterior (AP), translations, during open-chain activities, the femoral medial condyle center (FMCC) tended to be more posterior following UKA relative to the native knee in mid-flexion and above. AP excursions of the FMCC were small in all tested motions, however. There was substantial AP translation of the femoral lateral condyle center during passive motion before and after UKA, which was significantly different for flexion angles > 38°. Our study data demonstrate that the kinematics of the unloaded knee following MB UKA closely resemble those of the native knee while relative medial overstuffing with UKA will result in the joint being more valgus. However, replacing the conforming and rigidly fixed medial meniscus with a mobile inlay may successfully prevent aberrant posterior translation of the medial femoral compartment during passive motion and squatting motion.

The recently reintroduced bicruciate-retaining Total Knee Arthroplasty (BCR TKA) is an interesting approach in the quest for close replication of knee joint biomechanics and kinematics closer to the native knee. Therefore, this study aimed at providing a detailed biomechanical view on the functional resemblance of BCR TKA to the native knee joint. Seven fresh-frozen full leg cadaver specimens (76 ± 10 year) were mounted in a 6 degrees-of-freedom kinematic rig that applied a dynamic squatting motion knee flexion. Two motion patterns were performed pre- and post-implantation of a fixed bearing BCR TKA: passive flexion–extension and squatting while an infrared camera system tracked the location of reflective markers attached to the tibia and femur. Additionally, specimen laxity was assessed using Lachman tests and varus/valgus stress tests in triplicate. Overall, differences in tibiofemoral kinematics between native knee and BCR TKA were small. Some minor differences appeared under the load of a squat: less internal tibial rotation and some minor paradoxical anterior translation of the medial femoral condyle during mid-flexion. BCR TKA may slightly elevate the joint line. Knee laxity as measured by the Lachman and varus/valgus tests was not significantly influenced by BCR TKA implantation. As both cruciate ligaments are preserved with BCR TKA the unloaded knee closely resembles native knee kinematics including preserving the rollback mechanism. The loss of the conforming anatomy of menisci and tibial cartilage and replacement via a relatively flat polyethylene inlay may account for the loss of tibial internal rotation and the slight paradoxical AP motion of the medial femoral condyle with BCR TKA. This phenomenon reproduces findings made earlier with fixed bearing unicondylar knee arthroplasty.

Impingement of the prominent anterior inferior iliac spine (AIIS) against the femoral neck has recently been described as another type of impingement. The purpose of this study is to provide a distribution of AIIS types using the classification proposed by Hetsroni and thus report on the prevalence of prominent types. A total of 400 patients were included in the study with an average age 27.3 ± 6.9 years (range 18–40). All patients received a whole-body polytrauma computer tomography (CT) scan in the emergency room (ER) upon arrival. The classification of AIIS proposed by Hetsroni et al., which describes three morphological types, was used. Type II and III were grouped as prominent types. The measurements were performed in all three planes by two examiners. Male to female ratio was 71:29. Type I was observed in 367 (91.7%) patients. Type II was observed in 31 (7.8%) patients and type III was observed in 2 (0.5%) patients, unilaterally. Prominent types were much more prevalent in men (10.5%) than in women (2.6%). The CT assessment demonstrated excellent intra- and interreliability (overall: 0.926, I/II: 0.906, III: 1.000). A young population demonstrates a prevalence of a prominent AIIS of 11.5%. Prominent AIIS is more common in men than in women.

Background Elevated serum levels of chromium and cobalt ions in metal-on-metal (MoM) bearing surfaces is a well-known phenomenon in THA. However, few studies have addressed this issue in complex primary and revision knee arthroplasty using a MoM hinged mechanism, and no study, to our knowledge, has investigated knees with MoM hinges in patients without megaprostheses (tumor prostheses). Questions/purposes We analyzed a series of patients who received MoM hinged revision knee prostheses and asked: (1) What are the serum metal ion levels at short-term followup? (2) Is there any correlation between metal ion levels and the Knee Society Score (KSS) at this followup? Methods Between 2013 and 2017, we performed 198 revision knee arthroplasties, of which 32 (17.7%) were performed with a latest-generation MoM hinge knee design. In addition, three complex primary TKAs utilizing the same design were included in this study. The device features a metal-on-polyethylene bearing with a MoM hinge. During that period, our general indications for using a hinge were single-stage and two-stage revision surgeries, revisions with large bone defects, and primary TKA with > 20° mechanical malalignment or collateral ligament insufficiency. Of the 35 patients who received this device, 23 patients (65% of the overall group who received this implant; 11 males, 12 females) were available for followup at a median of 28 months (range, 13-61 months), and the remaining 12 (35%) patients were lost to followup. Our rationale for reporting before the more typical 2-year minimum was the finding of elevated serum ion levels with unclear clinical significance. Median age at the time of surgery was 68 years (range, 52-84 years). None of the patients included in the study had other implants with MoM bearings. Serum ion levels of chromium (III) and cobalt were assessed using mass spectrometry. Ion levels > 5 ppb were considered elevated. Clinical outcome was assessed using the original KSS. Results Median chromium serum level was 6.3 ppb (range, 0.6-31.9 ppb) and median cobalt serum level was 10.5 (range, 1.0-47.5 ppb). Of the 23 patients, 16 had elevated serum ion levels. There was a moderate correlation between KSS and both chromium (p = 0.029, r = 0.445) and cobalt (p = 0.012, r = 0.502) levels. Conclusions Elevated metal ion levels and radiolucent lines are common after surgery with this MoM hinge design at short-term followup, and we believe this finding is of great concern. Although no patient has yet been revised, these patients will be closely monitored. We recommend that serum ion analysis become a routine part of followup after any hinge TKA in an attempt to better understand the potential consequences of this phenomenon. Level of evidence Level IV, therapeutic study.

Balancing mobile-bearing (MB) unicondylar knee arthroplasty (UKA) is challenging. If performed improperly, potential complications include pain, implant loosening, or progression of osteoarthritis in the preserved compartment. The purpose of this study was to document effects of improper balancing on knee kinematics and joint contact stress. It was hypothesized that over-stuffing would lead to more valgus and higher lateral contact force. Seven fresh-frozen cadaver legs were mounted in a kinematic rig that applied three motion patterns to the specimens: passive flexion–extension, open chain extension, and squatting. During testing, an infrared camera system recorded the trajectories of markers rigidly attached to femur and tibia, while a pressure sensor measured contact pressure in the lateral compartment. Prior computer tomography scans allowed identification of coordinate frames of the bones and calculations of anatomical rotations and translations. Collateral ligament strains were calculated, and quadriceps forces recorded. Following testing on the native knee, a medial MB UKA was implanted in each specimen and all motion trials were repeated. Three inlay thicknesses were tested to simulate optimal balancing as well as under- (1 mm thinner) and over-stuffing (1 mm thicker) of the medial compartment relative to the optimal thickness. Under-stuffing of the medial compartment leads to kinematics closest to the native knee. Subjectively balanced and over-stuffed MB UKA knees were in more valgus. Lateral peak contact stress was higher from mid- to deep flexion following UKA in all three tested states; however, these results were not significant. Peak strain in the superficial medial collateral ligament (sMCL) was significantly higher in MB UKA, regardless of the inlay thickness mainly in mid-flexion. Inlay thickness had no significant impact on measured quadriceps force during squatting. The results underline the importance of optimal balancing. Over-stuffing should be avoided as it results in the largest kinematic changes relative to the native condition and induces higher strains in the sMCL. Based on the kinematic findings, it is advisable to use thinner inlays, as long as this is not compromising stability or risking inlay luxation.

Treatment of implant-associated osteomyelitis regularly involves the use of systemic antibiotics in addition to surgical intervention. However, it remains unclear if perioperative systemic application of bactericide substances can improve overall outcome in models of severe intramedullary infection. The present study investigated the use of systemic gentamicin in addition to a controlled local release from a highly lipophilic gentamicinpalmitate compound while the previous study showed efficacy of sole antibiotic implant-coating. Forty male Sprague–Dawley rats were divided into two groups receiving an intramedullary femoral injection of 102 CFU of a common methicillin susceptible Staphylococcus aureus strain (MSSA Rosenbach). Group I received an uncoated implant whereas group II received a coated implant. All animals received a single shot intraperitoneal application of gentamicinsulfate directly after wound closure while the historical control group III (n = 20) had no antibiotic treatment at all. Animals were observed for 28 and 42 days. Serum haptoglobin and relative weight gain were assessed as well as roll over cultures of explanted femur nails and histological scores of periprosthetic infection in dissected femora. Systemic application of gentamicin combined with antibiotic-coated implant did not further reduce bacterial growth significantly compared with systemic or local antibiotic application alone. Combined local and systemic therapy reduced serum haptoglobin significantly after day 7, 28 and 42 whereas systemic application alone did not compare to controls. Systemic perioperative and implant-associated application of antibiotics were both comparably effective to treat implant-associated infections whereas the combined antibiotic therapy further reduced systemic signs of infection time dependent.

BACKGROUND The internet has become one of the most important sources to obtain medical and health information. Parents, whose children are affected by systemic diseases, anomalies, deformities or further orthopaedic defective positions, use the internet to increase their knowledge. OBJECTIVE There is a lack of studies with focus of parental enquiries in the internet before contacting the pediatric orthopaedic surgeon. This study shows current trends and also allows a follow up. METHODS Parental internet search was evaluated using a standardized questionnaire. General habits of internet use, local hardware equipment, age and educational background of the parents were analyzed. In particular, parental use of general medical websites, use of search machines like Google or Yahoo or the use of homepages from support groups was asked. RESULTS A total of 521 questionnaires were completed, this corresponds to a response rate of 96%. One quarter of parents attended the consultation because of a gait anomaly or foot deformity, followed by children with DDH (20%), club foot (9%) and scoliosis (6%). 87% of parents use a Smartphone to get internet access, 68% a Laptop, 55% a Tablet and 45% a Laptop. Especially parents with children with clubfoot looked for health information online (80%), followed by scoliosis 69% (n=20), DDH 67% (n=66), foot deformity / gait anomaly 49% (n= 62). 98% of those using the internet for health medical purpose made use of a search engine, 99% (n=291) of internet users searched through Google, with 44% (n=129) of them describing their research helpful. Concerning use of social media responders of clubfoot children were again the most numerous in number (38%, n=18). 10 of them stated to have exchanged with other social media users and 60% of them evaluated social media as helpful. There were 35 parents who intended to discuss the results with their pediatric orthopedic surgeon. 84% of the responders who used the internet for health research would return to the internet. CONCLUSIONS This study documents that the internet is an important source of information for parents or caregivers in the field of pediatric orthopedics and that the meaning goes even further. Treating physicians will increasingly be confronted with the results of internet research. In particular, parents whose children suffer from club feet frequently research the Internet. CLINICALTRIAL The study was conducted in accordance with the principles laid down in the Declaration of Helsinki. Prior to the investigations, an approval was secured by the local board of ethics on 8 of September 2017 (AZ 107/17).

Posterior-stabilized (PS) and cruciate-retaining (CR) total knee arthroplasties (TKA) are both successfully used for treatment of end-stage osteoarthritis. The choice of constraint depends on knee deformity and stability as well as most importantly surgeon preference. The aim of this study was to compare the amount of blood loss and required transfusions following TKA with the two different designs. In a retrospective approach, 473 patients undergoing TKA were included (240 CR and 233 PS from a single manufacturer). Demographics at base line were comparable between both groups. Blood loss [red blood cell (RBC) loss] was calculated after documentation of pre- and postoperative hematocrit levels at discharge. Transfusion requirements were recorded. Statistical analysis was done using Mann–Whitney U test. The calculated blood loss (RBC loss) at discharge was 548 ± 216 ml in the PS group compared with 502 ± 186 ml in the CR group (p = 0.032). There were no differences in the transfusion requirements between both groups (PS 0.41 vs. CR 0.37, p = 0.39). The blood loss was significantly higher in the PS group. This may be due to the box preparation that exposes more cancellous femoral bone, which may add to postoperative bleeding. The differences remain, however, small, as they did not lead to a significantly higher transfusion rate with PS TKA.

Background aims The discovery of regenerative and immunosuppressive capacities of mesenchymal stromal cells (MSCs) raises hope for patients with tissue-damaging or severe, treatment-refractory autoimmune disorders. We previously presented a method to expand human MSCs in a bioreactor under standardized Good Manufacturing Practice conditions. Now we characterized the impact of critical treatment conditions on MSCs with respect to immunosuppressive capabilities and proliferation. Methods MSC proliferation and survival after γ irradiation were determined by 5-carboxyfluorescein diacetate N-succinimidyl ester and annexinV/4′,6-diamidino-2-phenylindole (DAPI) staining, respectively. T-cell proliferation assays were used to assess the effect of γ irradiation, passaging, cryopreservation, post-thaw equilibration time and hypoxia on T-cell suppressive capacities of MSCs. Quantitative polymerase chain reaction and β-galactosidase staining served as tools to investigate differences between immunosuppressive and non-immunosuppressive MSCs. Results γ irradiation of MSCs abrogated their proliferation while vitality and T-cell inhibitory capacity were preserved. Passaging and long cryopreservation time decreased the T-cell suppressive function of MSCs, and postthaw equilibration time of 5 days restored this capability. Hypoxic culture markedly increased MSC proliferation without affecting their T-cell-suppressive capacity and phenotype. Furthermore, T-cell suppressive MSCs showed higher CXCL12 expression and less β-galactosidase staining than non-suppressive MSCs. Discussion We demonstrate that γ irradiation is an effective strategy to abrogate MSC proliferation without impairing the cells' immunosuppressive function. Hypoxia significantly enhanced MSC expansion, allowing for transplantation of MSCs with low passage number. In summary, our optimized MSC expansion protocol successfully addressed the issues of safety and preservation of immunosuppressive MSC function after ex vivo expansion for therapeutic purposes.

Implant-associated osteomyelitis still represents a demanding challenge due to unfavourable biological conditions, bacterial properties and incremental resistance to antibiotic treatment. Therefore different bactericide or bacteriostatic implant coatings have been developed recently to control local intramedullary infections. Controlled local release of gentamicin base from a highly lipophilic gentamicin palmitate compound achieves extended intramedullary retention times and thus may improve its bactericide effect. Forty male Sprague-Dawley rats were divided into two groups receiving an intramedullary femoral injection of 102 colony-forming units (CFU) of a common methicillin susceptible Staphylococcus aureus strain (MSSA Rosenbach) and either an uncoated femur nail (Group I) or a nail coated with gentamicin palmitate (Group II). Animals were observed for 28 and 42 days. Serum haptoglobin and relative weight gain were assessed as well as rollover cultures of explanted femur nails and histological scores of periprosthetic infection in dissected femurs. Implants coated with gentamicin palmitate significantly reduced periprosthetic bacterial growth as well as signs of systemic inflammation compared with uncoated implants. Gentamicin palmitate appears to be a viable coating for the prevention of implant-associated infections. These findings will have to be confirmed in larger animal models as well as in clinical trials.

It is assumed that unicondylar knee arthroplasty (UKA) features kinematics close to the natural knee. Clinical studies have also shown functional benefits for UKA. There is to date only little biomechanical data to support or explain these findings. The purpose of this study was to investigate whether UKA is able to preserve natural knee kinematics or not. Six fresh frozen full leg cadaver specimens were prepared to be mounted in a kinematic rig with six degrees of freedom for the knee joint. Three motion patterns were applied before and after medial UKA: passive flexion–extension, open chain extension, and squatting. During the loaded motions, quadriceps and hamstrings muscle forces were applied. Infrared cameras continuously recorded the trajectories of marker frames rigidly attached to femur, tibia, and patella. Prior computer tomography allowed identification of coordinate frames of the bones and calculations of anatomical rotations and translations. Native kinematics was reproduced after UKA in all the specimens. In the unloaded knee and during open chain extension, femoral rollback patterns after UKA were very close to those in the native knee. During squatting, the medial femoral condyle after UKA tended to be more posterior and superior with flexion and there was less tibial internal rotation. The tibia was found to be more in valgus after UKA during all motion patterns. As ligaments, lateral compartment and patellofemoral anatomy are preserved with UKA; the unloaded knee closely resembles native kinematics. The slight kinematic changes that were found under load are probably due to loss of the conforming medial meniscus and to the mismatch in geometry and stiffness introduced by UKA. These patterns resemble those found in knees with significant loss of function of the medial meniscus.

Lumbar facet joint degeneration is a source of chronic low back pain, with an incidence of 15% to 45% among patients with low back pain. Various therapeutic techniques in the treatment of facet-related pain have been described in the literature, including intraarticular lumbar facet joint steroid injections and radiofrequency denervation. In this study, we compared the effectiveness of intraarticular facet joint steroid injections and radiofrequency denervation.Our randomized, double-blind, controlled study included patients who received intraarticular steroid infiltrations in the lumbar facet joints (L3/L4-L5/S1) and patients who underwent radiofrequency denervation of L3/L4-L5/S1 segments. The inclusion criteria were based first on magnetic resonance imaging findings showing hypertrophy of the facet joints L3/L4-L5/S1 and a positive response to an intraarticular test infiltration of the facet joints L3/L4-L5/S1 with local anesthetics. The primary end point was the Roland-Morris Questionnaire. Secondary end points were the visual analog scale and the Oswestry Disability Index. All outcome assessments were performed at baseline and at 6 months.Fifty-six patients were randomized; 24 of 29 patients in the steroid injection group and 26 of 27 patients in the denervation group completed the 6-month follow-up. Pain relief and functional improvement were observed in both groups. There were no significant differences between the 2 groups for the primary end point (95% confidence interval [CI], -3 to 4) and for both secondary end points (95% CI for visual analog scale, -2 to 1; 95% CI for Oswestry Disability Index, -18 to 0).Intraarticular steroid infiltration or radiofrequency denervation appear to be a managing option for chronic function-limiting low back pain of facet origin with favorable short- and midterm results in terms of pain relief and function improvement, but improvements were similar in both groups.

In an earlier paper, it was shown that tailored magnetic resonance imaging (MRI) allows for reproducible analysis of the preserved knee joint structures after patellofemoral replacement (PFR).This pilot study investigates to what degree MRI could produce reliable assessment of the implant-bone interface of femoral and patellar components and rotational alignment following PFR.MRI tailored for reduction of metallic artefacts was performed in seven patients who had undergone PFR. Two independent investigators evaluated the implant-bone interface at femoral and patellar components and the rotational alignment of the femoral component. They also assessed their degree of confidence in evaluation using a five-point scale. The inter-observer reliability was determined.Implant-induced MRI artefact was barely observed and there was no interference with component-bone interface evaluation. There was excellent inter-observer reliability, inter-observer agreement, and confidence for the implant-bone interface at femoral and patellar components and for rotational alignment. The applied score for the interface was found to be reliable.Tailored MRI allows reproducible analysis of the implant-bone interface and of rotational alignment of the femoral component in patients who have had PFR. It might prove helpful in the assessment of painful PFR.

Purpose The aim of this study was to assess the reproducibility of using magnetic resonance imaging (MRI) to analyze the preserved anatomic knee compartments following unicondylar knee arthroplasty (UKA) with zirconium femoral components. It was hypothesized that evaluation of the cartilage, ligaments, meniscus, and tendons would result in a high rate of inter-observer reliability. Scope Ten patients underwent MRI of the knee tailored to reduce metallic artifact following medial UKA with zirconium femoral implants. Cartilage, external meniscus, collateral and cruciate ligaments, the quadriceps and patellar tendons, and the presence of joint effusion were evaluated by two independent investigators. The reviewers provided degrees of confidence with their evaluation of each parameter through the use of a five-point scale. Inter-observer agreement was calculated and inter-observer reliability was determined by use of Cohen's Kappa. Artifacts originating from the implants were rarely observed. There was excellent inter-observer reliability (i.e., high Cohen's Kappa) for all assessed structures, and a high level of observer confidence for the evaluation of the cartilage, meniscus, tendons, ligaments, and joint effusion. Conclusion In this study tailored MRI allows for reproducible analysis of the preserved knee joint compartment after UKA for zirconium implants. This technique might prove helpful in the assessment of painful knee joints after UKA with other metallic materials as new MRI software programs, which suppress metal artifacts, are developed.

Dank der Fortschritte in der Behandlung von Patienten und Patientinnen mit neuromuskularen Erkrankungen verlangert sich die Lebenserwartung der Betroffenen. Als Konsequenz konnen die Erkrankten altersbedingte degenerative Veranderungen der Gelenke entwickeln, die eine endoprothetische Versorgung erfordern.

Introduction No evidence-based guidelines are available to determine the appropriate stem length, and whether or not to cement stems in revision total knee arthroplasty (TKA). Therefore, the objective of this study was to compare stresses and relative movement of cemented and uncemented stems of different lengths using a finite element analysis. Materials and methods A finite element model was created for a synthetic tibia. Two stem lengths (95 and 160 mm) and two types of fixation (cemented or press fit) of a hinged TKA were examined. The average compressive stress distribution in different regions of interest, as well as implant micromotions, was determined and compared during lunge and squat motor tasks. Results Both long and short stems in revision TKA lead to high stresses, primarily in the region around the stem tip. The presence of cement reduces the stresses in the bone in every region along the stem. Short stem configurations are less affected by the presence of cement than the long stem configuration. Press-fit stems showed higher micromotions compared to cemented stems. Conclusions Lowest stresses and micromotion were found for long cemented stems. Cementless stems showed more micromotion and increased stress levels especially at the level of the stem tip, which may explain the clinical phenomenon of stem-end pain following revision knee arthroplasty. These findings will help the surgeon with optimal individual implant choice. ispartof: Archives of Orthopaedic and Trauma Surgery vol:136 issue:12 pages:1741-1752 ispartof: location:Germany status: published

Ultrasonography of the hip has gained wide acceptance as reliable method for diagnosing developmental hip dysplasia in infants. This blinded study was conducted to investigate the influence of two linear probes with different frequency on diagnostic accuracy and reproducibility. In 206 consecutive newborns, the bony roof angle (α-angle) and cartilage roof angle (β-angle) were assessed by three investigators according to Graf. The hips were measured twice both with a 7.5 MHz and a 12 MHz linear transducer (Sonoline G60S ® ultrasound system; Siemens, Erlangen, Germany). Each investigator evaluated his sonograms 6 weeks later. Depending on the mean values for α-angle and β-angle, the hips were classified. Reproducibility of the Graf classification was not found to be influenced. In two of three investigators, we observed significant improvement concerning variation of the β-angle with the 12 MHz probe. The use of high-resolution transmitters may improve diagnostic accuracy in ultrasonography of the newborn’s hip.

Aim Two different measurement techniques of ultrasonograms of the infant hip were evaluated with respect to reproducibility of the Graf classification and variation of α- and β-angles. Material and methods In a cross-sectional, blinded study, the hips of 207 consecutive newborn babies (101 male; 106 female) were sonographically screened at an average of 2.64 days after birth. Each hip was measured twice by three investigators with different levels of experience - a paediatric orthopaedic surgeon, a senior surgeon and a trained medical student. A mobile ultrasound system (SONOLINE G60S®, Siemens, Erlangen, Germany), equipped with a 7.5 MHz linear transducer, was used. Both hip joints were measured twice by all three investigators. The measurement was performed 6-8 weeks later in a blinded manner. The sonograms were initially printed out on high-quality paper strips and measured by pencil, ruler and goniometer. Finally, each investigator evaluated the same sonograms computer-assisted, using the trackball and dashboard of the ultrasound system. Results Concerning intraobserver reliability, we observed a significant reduction of variation both for α- and β-angles in favour of the classic measurement on printed strips (p 0.05). Conclusions This study demonstrated considerable advantages for the classic measurement of paediatric hip ultrasonograms with pencil and goniometer on printed paper strips compared to computer-aided measurement concerning variation of α- and β-angles.

Several operative techniques have been described for recurrent patellar dislocation. Clinical results vary depending on the procedure and indication. The present study aimed to evaluate the clinical outcome of Insall’s proximal realignment for recurrent patellar dislocation at mid-term follow-up. Forty-five patients were reviewed with a mean follow-up period of 49 months after having undergone Insall’s procedure. Outcome measures included reports of redislocations, complications, patient-reported outcome scores (Kujala, Tegner activity scale) and subjective assessment. No statistically significant improvements (p < 0.05) in patient-reported outcome measures were noted. Sixteen patients (35%) had poor to fair results using the Kujala score. Subjective assessment revealed that 12 patients (27%) were dissatisfied with the outcome of their surgery and would not undergo the same procedure. Ten patients (22%) had suffered from redislocation at the latest follow-up. In 4 cases (9%), intra-articular knee hematoma occurred which required arthroscopic intervention. The overall mid-term outcome of the present study shows low patient satisfaction. Non-anatomic realignment for recurrent patellar dislocation does not adequately prevent redislocation.

The affect of anterior cruciate ligament (ACL) integrity on the early postoperative stability of a collagen type-I gel scaffold was investigated. The value of fibrin glue for graft fixation in ACL deficient porcine knees over a simulated early postoperative period was also studied.Full-thickness articular cartilage defects (11 × 6 mm) were created on the medial femoral condyle of 80 porcine knees. The ACL was left intact or completely transected in each of 40 knees. Gel plugs were tested in each group: press-fitting only in 20 specimens and press-fitting plus fibrin glue in 20 specimens. Each knee underwent 2,000 cycles in a validated ex-vivo continuous passive motion model.Press-fit-only fixation grafts in knee specimens with an intact ACL showed significantly superior stability than that in ACL deficient knees (p = 0.01). In ACL deficient knees, grafts fixed with press-fitting plus fibrin glue showed significantly superior stability than those using press-fit only fixation (p = 0.01). Press-fitting plus fibrin glue fixation showed no significant differences in worn surface area between knee specimens with intact and deficient ACL.ACL deficiency led to early scaffold instability in an ex-vivo porcine knee model. Fibrin glue in ACL deficient knees led to additional graft stability. These findings indicated that cartilage regenerative techniques may give optimum results in ACL intact knees.

Purpose Several well-described techniques are available for the treatment of chondral and osteochondral defects. The aim of the study was to assess the efficacy of a singlestage procedure incorporating a new cell-free collagen type I gel for the treatment of small chondral and osteochondral defects in the knee evaluated at 2-year follow-up. Methods Fifteen patients were treated with a cell-free collagen type I gel matrix of 11 mm diameter. The grafts were implanted in the debrided cartilage defect and fixed by press-fit only. The clinical outcome was assessed preoperatively and at 6 weeks, and 6, 12 and 24 months after surgery using the International Knee Documentation Committee (IKDC) score, Tegner activity scale and visual analogue scale (VAS). Graft attachment rate was assessed 6 weeks postoperatively using magnetic resonance imaging (MRI). Cartilage regeneration was evaluated using the Magnetic Observation of Cartilage Repair Tissue (MOCART) score at 6, 12 and 24 months after implantation. Clinical results were correlated with MRI findings. Results Six male and nine female patients were included in this study, with a mean age of 26 (range: 19‐40). No complications were reported. The mean VAS values after 6 weeks and the mean IKDC patient values after 6 months were significantly improved from the preoperative values (P = 0.005 and P = 0.009, respectively). This improvement remained up to the latest follow-up. There were no significant differences between the median preoperative and postoperative Tegner values (n.s.). Significant improvement of the mean MOCART score was observed after 12 months and remained by 24 months (P \ 0.001). MR images showed that in 14 of the 15 patients, the graft was completely attached by 6 weeks postoperatively. At 24 months after implantation, MRI demonstrated complete filling in all cases with a mainly smooth surface, complete integration of the border zone, homogenous structure of the repaired tissue and nearly normal signal intensity. No correlation between any variables of the MOCART score and the clinical scores was observed. Conclusions The present study reveals that the new method produces both good clinical and magnetic resonance imaging results. Use of press-fit only implanted grafts of a smaller diameter leads to a high attachment rate at 24-month follow-up. Level of evidence IV.

Meniscal loss is associated with an increased risk of developing osteoarthritis. Tissue engineering solutions, which include the development of novel material scaffolds, are being utilised to aid the regeneration of meniscal tissue. The purpose of this study was to monitor the safety profile and the short-term efficacy of a novel polyurethane meniscal scaffold in the treatment of patients with painful knees following partial medial meniscectomy. Ten consecutive patients with segmental tissue loss from the medial meniscus were treated with the arthroscopic implantation of an Actifit® (Orteq Sports Medicine) polyurethane meniscal scaffold. Patients were followed up at 2 and 6 weeks, then again at 6 and 12 months. Primary outcome measures included reporting of complications and patient-reported outcome scores (KOOS, KSS, UCLA Activity scale, VAS pain). Secondary outcome was MRI assessment at 6 and 12 months looking at scaffold morphology, integration and associated joint injury/inflammation. Eight male and 2 female patients were included in the study with a mean age of 29 (range 18–45). No complications were reported. All patients were happy with their surgery. At 6 months, a statistically significant improvement (P

Objective: To evaluate the expression of VEGF by chondrocytes of hyaline cartilage during the course of osteoarthritis (OA). Methods: In 12 white New Zealand rabbits the anterior cruciate ligament (ACL) was resected to create an anterior instability of the knee. In 12 control rabbits only a sham operation without resection of the ACL was done. Four animals of each group were killed at 3, 6, and 12 weeks. The load bearing area was evaluated histologically according to Mankin and by immunostaining for VEGF. Results: In the experimental group, histological grades of OA showed a positive linear correlation with the time after surgery. Immunostaining showed an increased expression of VEGF in the control group after 3 weeks, which dropped to normal after 6 weeks. There was no difference in the progression of OA between control and experimental groups after 3 weeks, but a significant difference was seen after 6 (p=0,01) and 12 (p=0,05) weeks. A significant positive correlation between VEGF expression and the histological grade of OA was found (r = 0.767; p

The theoretical superiority of mobile-bearing total knee arthroplasties (TKAs) has not yet been proven in clinical studies. The aim of the current study was to compare and to analyse in a patient population that had received either a fixed or a mobile TKA differences in gait analysis electromyography and clinical scores.In a prospective, randomized, patient- and observer-blinded clinical study, 33 patients with primary osteoarthritis of the knee were included. All patients received a Genesis II total knee replacement. Sixteen patients received a mobile and 17 a fixed-bearing cruciate retaining Genesis II TKA. Clinical and quality-of-life scores, electromyography and gait analysis were applied preoperatively and postoperatively with a follow-up of 24 months.In both groups, improvements from pre- to postoperative were detected. whereas the results of gait analysis and electromyography did not show any differences. The results from the clinical and the quality-of-life scores improved from pre- to postoperative, while the Knee Society Score showed a superiority of the mobile-bearing group (mean 159 ± 28) over the fixed-bearing group (mean 134 ± 41).No functional advantage of mobile over fixed-bearing TKA was detected, although the mobile-bearing group had better clinical results for which a reason could not be found. These results only apply to cruciate retaining mobile-bearing TKA with a bearing which allows both rotation and anteroposterior translation.

Mesenchymal stem cell differentiation of osteoblasts is triggered by a series of signaling processes including integrin and bone morphogenetic protein (BMP), which therefore act in a cooperative manner. The aim of this study was to analyze whether these processes can be remodeled in an artificial poly-(l)-lactide acid (PLLA) based nanofiber scaffold. Matrices composed of PLLA-collagen type I or BMP-2 incorporated PLLA-collagen type I were seeded with human mesenchymal stem cells (hMSC) and cultivated over a period of 22 days, either under growth or osteoinductive conditions. During the course of culture, gene expression of alkaline phosphatase (ALP), osteocalcin (OC) and collagen I (COL-I) as well as Smad5 and focal adhesion kinase (FAK), two signal transduction molecules involved in BMP-2 or integrin signaling were analyzed. Furthermore, calcium and collagen I deposition, as well as cell densities and proliferation, were determined using fluorescence microscopy. The incorporation of BMP-2 into PLLA-collagen type I nanofibers resulted in a decrease in diameter as well as pore sizes of the scaffold. Mesenchymal stem cells showed better adherence and a reduced proliferation on BMP-containing scaffolds. This was accompanied by an increase in gene expression of ALP, OC and COL-I. Furthermore the presence of BMP-2 resulted in an upregulation of FAK, while collagen had an impact on the gene expression of Smad5. Therefore these different strategies can be combined in order to enhance the osteoblast differentiation of hMSC on PLLA based nanofiber scaffold. By doing this, different signal transduction pathways seem to be up regulated.

Nanofibre scaffolds are suitable tools for bone tissue engineering. Mimicking the extracellular matrix, they allow for cell growth and differentiation. However, in large 3D scaffolds, uniform cell colonisation presents an unsolved problem. Our aim was to design and analyse a method of colonising nanofibre scaffolds, combining electrospinning of fibres and electrospraying of cells, to determine its impact on cell survival, growth, and gene expression. The osteoblast-like cell line MG63 was suspended in medium and electrosprayed into growing scaffolds of poly-(l-lactic acid) (PLLA) or PLLA/Col-I blend nanofibres. Fluorescein diacetate (FDA) staining was used to determine survival and growth over a 22 d culture period. Expression of osteocalcin (OC) and type I collagen (Col-I) genes was determined by real time PCR. Fluorescence microscopy was used to analyse Col-I and OC deposition, as well as cell densities. While spraying distance and cell density in the spraying solution influenced survival and cell density, the combination of electrospinning and electrospraying did not negatively influence the maintenance of the osteoblast phenotype. Furthermore, VEGF induction in response to hypoxia was not suppressed, but modulated by polymer composition. Therefore, simultaneous electrospinning and electrospraying is a suitable tool in producing nanofibre based 3D cell seeded scaffolds.

STUDY DESIGN A case report to describe the first case of an acute central canal dilatation after minimally invasive lateral cervical decompression. OBJECTIVE To emphasize the need of being aware of this rare spinal disorder. SUMMARY OF BACKGROUND INFORMATION A holocord syrinx is known as a complication of Chiari malformation. Furthermore, it can occur spontaneously, after trauma or infection. METHODS A 63-year-old patient with a left-sided nerve root stenosis, C3/C4, because of uncovertebral and intervertebral joint osteoarthritis with paresis of the left deltoid muscle, underwent minimally invasive decompression of the C4 nerve root according to the Frykholm approach. RESULTS An immediately postoperative recognizably complete paresis of the right arm was because of hydromyelia from the fourth ventricle down to the thoracic spine. A minimal edema of the spinal cord was present. No abnormality of the spinal cord had been detected on preoperative magnetic resonance imaginary (MRI).At revision surgery high pressure was found within the hydromyelia. Subarachnoid drainage did not improve the neurologic deficits. On account of increasing edema of the spinal cord paraplegia developed, which almost completely resolved after further revision. CONCLUSION The reason for the hydromyelia is unclear. Routinely used MRI is not able to detect a collapsed central canal of the spinal cord. Acute hydromyelia causes permanent neurologic deficits whereas edema might lead to transient disturbances.

Grice-Green extra-articular subtalar arthrodesis is a treatment option for advanced valgus rearfoot deformity of neuromuscular origin in young patients. The purpose of this study was to evaluate long-term results of the procedure in ambulatory cerebral palsy patients. From January 1975 to December 1993, 57 operations were performed in 39 patients (22 males, 17 females) with a mean age of 7.8 ± 2.7 (range 3.9–14.4) years for excessive symptomatic hindfoot valgus. Thirty-five patients (51 feet) were followed for a mean 22.6 ± 4.6 (range 16.0–32.3) years. Preoperative GMFCS score, ambulation, hindfoot position, podoscopic view of the weight-bearing feet, and radiological examinations, along with complications and orthotic use, were compared. Based on a clinical rating scale, 39 results were excellent or good, 8 were fair, and 4 were poor. The poor results were attributed to hindfoot valgus recurrence or varus overcorrection. One case needed revisional surgery owing to slippage of the graft. Overall, the GMFCS score, level of ambulatory distance, and use of foot orthoses improved. Grice-Green subtalar arthrodesis did not result in early degenerative changes at the midterm follow-up. The procedure offers safe and long-lasting correction for severe and symptomatic hindfoot disorders in patients with cerebral palsy. Together with physiotherapy and orthotic use, it can improve ambulation. Whereas a slight hindfoot valgus in patients with cerebral palsy is tolerable without lack of function, overcorrection should be avoided.

Unicompartmental knee arthroplasty (UKA) has been proven to be a viable procedure in case of medial osteoarthritis of the knee joint. Minimally invasive surgery (MIS) techniques have been described to facilitate recovery after surgery. The aim of this study was to rule out major failure mechanisms and to obtain clinical data for comparison between a conventional and the MIS approach.A consecutive series of 163 UKA (160 patients) were retrospectively included (83 conventional and 80 MIS interventions). Patients were invited for a clinical examination including clinical scores (KSS, Lequesne, UCLA, VAS, Feller- and Turba Patella Scores). Seven patients (4.3%) were lost to follow-up.Average follow-up was 4.6 ± 1.3 (1.5-6.8) years. Average age at operation was 67.5 ± 7.9 (45-81) years. Fifteen implants had been converted to TKA (9.2%). There were seven conversions to TKA in the MIS and 8 in the conventional group. Of the applied clinical scores there were better values for the Turba patella score in the MIS group. Differences of the other scores were not statistically significant.Comparable functional results for both UKA procedures could be shown. There were no significant differences in terms of clinical scores or revision rates. The MIS approach in medial UKA did not show any major complications. Its use seems to be safe.

Safety and efficacy of unicompartmental knee arthroplasty (UKA) in unicompartmental osteoarthritis (OA) has been shown in large patient series. It has been matter of discussion whether or not spontaneous osteonecrosis of the knee (SONK) can successfully be treated with UKA. A retrospective approach included 52 cases of UKA for SONK of the femoral condyles. Four implants were revised (7.7%), and seven patients had died. Nine patients were interviewed by telephone, 28 followed the invitation for clinical examination including clinical scores (KSS and WOMAC) and radiographs. Satisfaction of patients was recorded in four categories. Four patients (7.7%) were lost to follow-up. Average follow-up was 10.9 ± 4.8 years (4–25). Average age at operation was 66.6 ± 9.7 years. The KSS score increased from a preoperative 85 ± 30 to 173 ± 27 (p

Background Revision total hip arthroplasty (THA) has gained importance over the past few years. However, in the literature, there are many recommendations for both surgical intervention and postoperative rehabilitation. The purpose of this nationwide German survey was to identify the actual treatment of revision THA and to compare the findings of this study with guidelines in the current literature. Materials and methods All orthopedic and traumatological hospitals listed in the "List of German Hospitals 2006" were invited via e-mail to take part in an anonymous survey. The questionnaire contained general questions such as hospital and department size and particular questions regarding the treatment of revision THA patients of each interviewed department. Results A total of 578 (44.7%) of all invited hospitals took part in this study. Out of these, 463 (78%) hospitals performed revision THA. Mostly, cementless revision stems and cementless press-fit cups were used as revision implants. Differences in proceeding revision THA were found in infection THA and in particular if the infection appeared early (after 6 weeks following implantation). In a high number of cases the patient was sent to inpatient rehabilitation in the early postoperative course with nursing aspects being more important for the elderly and immobile patient at this postoperative point. Discussion and conclusion In many aspects, revision THA is not performed consistently in Germany. In particular, in the postoperative course, a standardized therapeutic pathway was not always identified.

The aim of this study was to characterize the influence of functionalization of synthetic poly-(L-lactic acid) (PLLA) nanofibers on mechanical properties such as maximum load, elongation, and Young's modulus. Furthermore, the impact of osteoblast growth on the various nanofiber scaffolds stability was determined. Nanofiber matrices composed of PLLA, PLLA-collagen, or BMP-2–incorporated PLLA were produced from different solvents by electrospinning. Standardized test samples of each nanofiber scaffold were subjected to failure protocol before or after incubation in the presence of osteoblasts over a period of 22 days under osteoinductive conditions. PLLA nanofibers electrospun from hexafluoroisopropanol (HFIP) showed a higher strain and tended to have increased maximum loads and Young's modulus compared to PLLA fibers spun from dichloromethane. In addition, they had a higher resistance during incubation in the presence of cells. Functionalization by incorporation of growth factors increased Young's modulus, independent of the solvent used. However, the incorporation of growth factors using the HFIP system resulted in a loss of strain. Similar results were observed when PLLA was blended with different ratios of collagen. Summarizing the results, this study indicates that different functionalization strategies influence the mechanical stability of PLLA nanofibers. Therefore, an optimization of nanofibers should not only account for the optimization of biological effects on cells, but also has to consider the stability of the scaffold.

Evaluation of gait performance and muscle activity patterns as well as clinical efficacy and safety after intraarticular injections with hyaluronan (Ostenil) compared with triamcinolone (Volon A10) injections in patients with knee osteoarthritis. This was a prospective, randomised, double-blind clinical trial evaluating the influence of five injections of hyaluronan or triamcinolone on gait pattern and muscle activity. For the clinical evaluation visual analogue scale, Lequesne index, and Knee Society Score were used. Quality of life was estimated with the SF-36. The definitive analysis was performed on the population who received all five injections and were examined in the two follow-up visits. Fifteen patients were treated with triamcinolone and 20 with hyaluronan. Significant improvement could be demonstrated for pain scale and clinical scores in both groups. Gait patterns showed significant differences only for Knee Abduction Moment (p=0.007) in the hyaluronan group and for Maximum Vertical Force 1 and 2 between the both groups in the follow up visit (p=0.018) (p=0.019). In both groups there was no significant difference regarding to muscle activity. Quality of life showed no changes in all visits between the groups. Hyaluronan was not superior to triamcinolone. The results suggest that treatment with hyaluronan can reduce pain and improve knee function. A significant short term improvement in gait and muscle activity patterns, however, was not observed, in either hyaluronan or triamcinolone.

The aim of this study was to functionalize the surface of synthetic poly-(l-lactic) (PLLA) nanofibers with RGD peptide, in order to promote growth and osteogenic differentiation of human mesenchymal stem cells (hMSC) in vitro. The cRGD was coupled onto PLLA nanofibers using oxygen plasma combined with EDC/sulfo-NHS activation. Matrices were seeded with hMSC and cultivated over a period of 22 days under growth conditions and analyzed during the course of cultivation. The plasma activation of PLLA nanofibers resulted in a reduction of hydrophobicity as well as a formation of carboxyl groups on the surface of the fibers. Furthermore, maximum load, but not young's modulus was influenced by the treatment with oxygen plasma. When hMSC were cultured onto the cRGD functionalized scaffolds, cells showed no increased proliferation or cell density but an induction of genes associated with the osteoblast lineage. In brief, this study indicates that functional peptides of the extracellular matrix can be coupled onto PLLA nanofibers using plasma treatment in combination with EDC/sulfo-NHS treatment. These groups are accessible for the growing cell and mediate probably some osteoinductive properties of collagen nanofibers.

AIM The aim of the study was to survey the current state of the conservative and operative treatment of anterior shoulder instability and its rehabilitation in German hospitals. METHODS A previously evaluated online questionnaire was sent out to all German hospitals with orthopaedic or trauma surgery departments. The Federal Statistical Office's hospital list was the basis for the selection of hospitals. The questions referred to the year 2007. The survey, including 3 reminders, was conducted over 3 months. The questionnaire consisted of 6 response categories: always (100%), almost always (99-81%), predominantly (80-51%), rarely (50-21%), almost never (20-1%) and never (0%). RESULTS The response rate was 41% and 67% of these had carried out shoulder stabilisations. In total, 99.2% of the 67% were evaluable. The proportion of shoulder surgery was 8.4% of the total number of operations. Shoulder stabilisations represented 10.6% of these operations. A specialised shoulder department existed in 22.9%. Conservative treatment was carried out with an immobilisation of the arm "predominantly", "almost always" and "always" for internal rotation in 70.8% and in 23.4% for external rotation. The shoulders were "predominantly", "almost always" and "always" stabilised in an arthroscopic technique in 68.2% and in an open one in 31.8% of the clinics. With 92.9%, the Bankart repair was the most common operation. Shoulder instability was principally treated with the arthroscopic technique, regardless of the care level and department and is considered the best surgical technique. Physiotherapy was prescribed "always" and "almost always" in 99.3%. The rate of reluxation after conservative treatment was estimated at 35.5%, after operative open anterior shoulder stabilisation at 9.1% and after arthroscopic shoulder stabilization at 10.6%. Nevertheless, 49.4% of respondents expected the best results after arthroscopic treatment. Participants, who mainly applied the arthroscopic technique, expected a lower rate of reluxation in comparison to other techniques (p

PURPOSE Every day several million people are seeking for answers to medical problems via the internet. In particular parents, whose children are affected by systemic diseases, orthopaedic defective positions, anomalies or deformities, use the internet to increase their knowledge. Concerning this situation there is a lack of studies in the current literature. METHODS We investigated parental preparation to the outpatient paediatric orthopaedic consultation at our University Hospital with respect to internet enquiries or further sources of information using a standardised questionnaire. We assessed age and educational background of the parents, local hardware equipment and general habits of internet use. In particular, we retrieved parental use of search machines (e.g., Google.de, Yahoo.de), general medical websites (e.g., netdoktor.de) and websites from self-help groups (e.g., klumpfusskinder.de). RESULTS In total, 288 out of 300 questionnaires (96%) were evaluated. More than half of the parents (57%) were over 35 years of age and 78% were women. 82% of the study population had access to the internet at home and 70% used the internet regularly. More than 80% obtained information about the orthopaedic diseases of their child beforehand. Age and educational background of the parents were not significantly correlated with the extent of enquiries (p > 0.05). 90% of the parents, using the internet as source of information, frequented internet search machines; approximately one third used general medical websites. In particular in clubfeet we observed a highly significant (p < 0.001) tendency of parents to frequent websites from self-help groups. 60% of the study population assessed the internet information as useful; 92% will frequent the internet as source of information again. One third of the respondents is going to discuss the obtained internet information with the physician. CONCLUSIONS The internet is an important source of information for parents in the field of paediatric orthopaedics. Treating physicians will be increasingly confronted with the results of parental internet enquiries.

When highly conforming polyethylene inlays were introduced into total knee arthroplasty (TKA), they were characterized as adding anteroposterior stability to the reconstructed knee. The aim of this study was to examine the patellofemoral pressure with the designs of a highly conforming and a posterior stabilized inlay. The patellofemoral pressure depends among other factors on the anteroposterior stability of the knee joint.Eight fresh frozen human knee specimens underwent testing in a kinematic device. Knee motion was driven by a hydraulic cylinder at an extension moment of 31 Nm. The patellofemoral contact pressure was measured using a pressure sensitive film (Tekscan((R)), Inc., Boston, USA). First, this was assessed after implantation of a cruciate retaining (CR) TKA with a highly conforming polyethylene insert before and after resection of the posterior cruciate ligament. After that, the same measurements were performed with a similar posterior stabilized prosthesis.Patellofemoral contact pressures in the CR prosthesis using the highly conforming inlay were not significantly different before and after resection of the posterior cruciate ligament. However, after implantation of a posterior stabilized prosthesis peak pressure was significantly lower [Mean: 6.12, (SD 2.37) MPa] in comparison to the highly conforming type [7.12, (SD 2.53) MPa, P0.01] at a preserved posterior cruciate ligament. Further to that, the mean contact pressure turned out to be lower with the posterior stabilized design (P0.006).The results of this study suggest that a posterior stabilized prosthesis design reduces the patellofemoral peak and mean pressure in comparison with a high conforming design. The better reproducible femoral rollback with a posterior stabilized model at a tibial ventral shift could serve as a possible explanation.

Decreased quadriceps strength and fatigue is suspected to be one of the contributing factors for anterior knee pain and malfunction after total knee arthroplasty (TKA). The purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee isokinetically after TKA in dependence of different prosthesis designs and the state of the posterior cruciate ligament (PCL). Eight fresh frozen human knee specimens underwent testing in a kinematic device simulating an isokinetic knee extension cycle from 120° of flexion to full extension. The quadriceps force was measured after implantation of a cruciate retaining (CR) TKA (Genesis II, Smith&Nephew, Memphis, TN, USA) applying a conventional CR (11 mm) and a highly conforming (deep dished, DD) polyethylene (PE) inlay consecutively before and after resection of the PCL. Finally, tests were repeated with a posterior-stabilized (PS) design. Simulating a physiological knee extension, no significant differences in the average quadriceps force were detected between the cruciate preserving inlays (CR 1,146.57 ± 88.04 N, DD 1,150.19 ± 97.54 N, P = 0.86) as long as the PCL was intact. After resection of the PCL, the required quadriceps force increased significantly for both designs (CR 1,203.17 ± 91.51 N, P

AIM The aim of this study was to evaluate the current situation of rotator cuff repair and follow-up treatment in German hospitals. METHODS An evaluated survey, enquiring about the year 2006, was sent to all 777 German orthopaedic and/or trauma surgery departments. The hospitals were chosen using the official index of hospitals from the German Federal Statistical Office. RESULTS 44 % of the surveys were sent back, whereby 40 % were of use. Within the 309 departments, 26 % of the total number of 59,957 shoulder operations were rotator cuff repairs. Mini-open was the operation method in 49 %, open in 29 % and arthroscopic in 22 % of cases. Regarding the operational methods, there were differences between the departments and level of care. The arthroscopic technique was used sometimes in 48 % of the departments, whereas 52 % never used it. Specialised shoulder departments employed the total arthroscopic procedure more often. A set follow-up treatment occurred in 79 % of departments. CONCLUSION Rotator cuff repair is mainly carried out using the mini-open method, which is nowadays regarded as gold standard.

Ziel der Untersuchung war die Erhebung der diagnostischen Wertigkeit der in der Praxis haufig durchgefuhrten klinischen Funktionstests zur Diagnostik des Impingementsyndroms der Schulter. Es erfolgte eine systematische Literaturanalyse fur den Zeitraum von 1978 bis 2008 uber die PubMed-Datenbank. Nach vollstandiger Erfassung aller fur die Arbeit relevanten Artikel wurde die Qualitat der gefundenen Literatur bewertet und die Daten aus jedem Artikel analysiert. Die Qualitatsbeurteilung erfolgte unter Anwendung des Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS), das zur Einschatzung der internen und externen Validitat der einzelnen Studien diente. Insgesamt wurden elf Artikel aus der Literaturrecherche in die Datenerhebung mit eingeschlossen. Die ausgewahlte Literatur zeigte ein inhomogenes Datenmaterial mit zum Teil geringer Studienqualitat. Eine Vielzahl der klinischen Funktionstests wird fur unterschiedliche Pathologien verwendet. Die ausgewahlten Studien zeigen eine statistische Inhomogenitat, die sich durch verschiedene Kriterien ergibt. Die Einschlusskriterien der Patienten in den Studien sind unterschiedlich definiert, die Auswahlkriterien der Studienpopulation zum Teil unklar und nicht naher erlautert. Auch die Diagnosekritieren des Impingementsyndroms sind zum Teil uneinheitlich oder nicht klar definiert. In der Analyse zeigte sich eine breite Streuung in den angegebenen Werten fur die Sensitivitat und Spezifitat. Nur die haufig untersuchten Neer- und Hawkins-Kennedy-Tests zeigten reliable Ergebnisse. Die Analyse ergab, dass aufgrund der bisherigen Literatur kein Test eine hinreichende diagnostische Sicherheit als Screeningtest fur das Impingementsyndrom besitzt. Eine Kombination der klinischen Funktionstests kann zu einer Verbesserung der klinischen Diagnostik fuhren. Die Kombination verschiedener klinischer Tests dient als richtungweisendes diagnostisches Hilfsmittel. Zusatzliche Datenerhebungen, wie z. B. die Anamnese und die Durchfuhrung bildgebender Diagnostik (Sonographie, Rontgen, Magnetresonanztomographie) sind sinnvoll und empfehlenswert. Weitere prospektive und kontrollierte Studien mit einem einheitlichen Studienaufbau sind zur Evaluierung der klinischen Schultertests erforderlich.

Growth factors like bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF) play an important role in bone remodeling and fracture repair. Therefore, with respect to tissue engineering, an artificial graft should have no negative impact on the expression of these factors. In this context, the aim of this study was to analyze the impact of poly(L-lactic acid) (PLLA) nanofibers on VEGF and BMP-2 gene expression during the time course of human mesenchymal stem cell (hMSC) differentiation towards osteoblasts. PLLA matrices were seeded with hMSCs and cultivated over a period of 22 days under growth and osteoinductive conditions, and analyzed during the course of culture, with respect to gene expression of VEGF and BMP-2. Furthermore, BMP-2–enwoven PLLA nanofibers were used in order to elucidate whether initial down-regulation of growth factor expression could be compensated. Although there was a great interpatient variability with respect to the expression of VEGF and BMP-2, PLLA nanofibers tend to result in a down-regulation in BMP-2 expression during the early phase of cultivation. This effect was diminished in the case of VEGF gene expression. The initial down-regulation was overcome when BMP-2 was directly incorporated into the PLLA nanofibers by electrospinning. Furthermore, the incorporation of BMP-2 into the PLLA nanofibers resulted in an increase in VEGF gene expression. Summarized, the results indicate that the PLLA nanofibers have little effect on growth factor production. An enhancement in gene expression of BMP-2 and VEGF can be achieved by an incorporation of BMP-2 into the PLLA nanofibers.