Practicability of a Virtual Consultation to Evaluate the Shoulder Joint. / Durchführbarkeit einer digitalen Sprechstunde zur Untersuchung des Schultergelenkes.

OBJECTIVE: In the course of the corona pandemic, resource conservation and the protection of further infections have made it necessary to break new ground in the organisation of orthopaedic and trauma surgery consultations. One solution is consistent digitisation and the offer of video consultation hours. In this study, non-contact examination of patients with shoulder disorders is described and critically examined. METHODS: Thirty patients who presented with pathologies of the shoulder joint in a university outpatient clinic were subjected to a physical examination in a conventional and contactless manner. The data obtained on mobility, function and provocation test of both examinations were compared to draw conclusions about the virtual feasibility. RESULTS: 46% of the patients suffered from a traumatic shoulder lesion, and 54% showed degenerative lesions. The assessment of mobility showed a high correlation of 70 - 90% between the two examinations. Common tests to evaluate the supraspinatus, infraspinatus, subscapularis and the long head of the biceps could be adequately performed in a contactless version by more than three quarters of the patients, but with low-to-moderate performance values. CONCLUSION: Contact-less examination is particularly disadvantageous when evaluating stability criteria. For the medical history and functional test, there were no significant differences between the classic consultation and contactless consultation. Although virtual consultation is a widespread and valuable addition in pandemic times, it cannot replace a safe assessment and indication by personal examination.

A Feasibility Pilot Study on the Use of Telemedicine for the Examination of the Knee Joint. / Eine Pilotuntersuchung zur Machbarkeit der Videosprechstunde bei muskuloskelettalen Beschwerden des Kniegelenks.

BACKGROUND: In times of a pandemic threat, such as COVID-19, and the need for reduced direct doctor-patient contact, internet-based telemedicine has attracted more and more attention as a surrogate service. Suspending the diagnosis and treatment of non-virus related diseases for longer periods of time is not a viable option since this would only exacerbate problems on the patient and national level. The need for alternative treatment modalities increased rather quickly. So far, telemedical applications have mainly focused on teleradiological diagnosis, follow-up and monitoring of psychiatric and internal diseases, as well as geriatric patient care. As far as these authors are aware, orthopaedic physical examination of the knee joint, including trauma work-up, has not been the subject of any studies to date. This feasibility study explores how video consultation can be designed and implemented in the context of history taking and physical examination in knee joint complaints. MATERIAL AND METHOD: 21 patient actors (PA) with simulated complaints of the knee joint were examined individually for each diagnosis, first via video consultation and then directly by a specialist (SP). One PA group has a medical background, the other was made up of laypersons. The time was measured for both types of consultation. The physician documented the detected symptoms, the quality of implementation of the self-examination steps, and the derived diagnosis on an assessment form. After completion of both consultation sessions, the PAs were handed a questionnaire on the respective examination modality. RESULTS: With the video consultation the examination lasted 8.63 (± 2.5) minutes on average and with the regular consultation in person 5.63 (± 1.7) minutes (p < 0.001). For the group with medical background the examination lasted 7.67 (± 1.4) minutes on average, while for the lay group the video consultation took 9.7 (± 3.1) minutes (p = 0.049). With increased age, the video consultation was prolonged (p = 0.032; r = 0.47). The mean value for self-examination of leg axis, gait pattern and degrees of freedom was 9.32 (± 0.4) of 10 points. The following functional tests resulted in lower mean values (points): Payr 7.2 (± 2.3), Merke 5.9 (± 2.8), no-touch Lachmann 6.4 (± 2.7), gravity sign-recurvatum 6.7 (± 2.4). The mean grade by the PAs for the feasibility of self-examination was 2.43 (± 0.98) out of 5 points. CONCLUSION: The video consultation for musculoskeletal complaints of the knee joint allows exploratory remote examination and helps to minimise the number of patients in hospitals and practices. It takes longer for the physician to perform and does not permit functional testing for ligament injuries of the knee joint. In its present form, telemedical examination is not able to fully replace personal consultation.

[Reliability of the FFP classification in pelvic fractures]. / Anwendungsverlässlichkeit der FFP-Klassifikation bei Beckenfrakturen.

BACKGROUND: Pelvic fractures are typical for frail geriatric patients. They are characterized by increasing pain and loss of mobility. As geriatric pelvic fractures differ from the typical high velocity injuries, Rommens and Hofmann recommended a new classification for fragility fractures of the pelvis (FFP) in 2013. In addition to the location of the fracture they also assessed the degree of dislocation. OBJECTIVE: Compared to known fracture classifications of the pelvis, the FFP classification appears complex. Therefore, this study was designed to investigate the interobserver reliability of the FFP classification. MATERIAL AND METHODS: The members of the Section of Geriatric Traumatology (DGOU) were presented with 10 DICOM data sets with fractures of the pelvis for classification. As a reference the classification of P.M. Rommens, the author of the FFP, was established. RESULTS: In this study 24 consultants (47%) and 27 (53%) residents took part. Also, six radiologists were invited to participate. A total of 493 assessments were made. In 184 (37%) cases there was agreement with the reference, in 183 (37%) computed tomography images the fractures were classified lower, in 26 (26%) higher than the reference. This initially resulted in a Cohens κ coefficient of 0.36. This corresponds to a sufficient agreement (fair) according to Garbuz. With the reduction of the classification to four main groups, the Cohens κ coefficient increased to a satisfactory value. CONCLUSION: The reasons for the partly low agreement could be the participants' lack of experience and an inaccurate description of the classification levels. In the end, however, the FFP classification is the only one that meaningfully represents pelvic fractures of geriatric and frail patients. By simplifying to the four main groups, a better interobserver reliability is achieved. For a successful treatment, however, attention to the individual patient and the "fracture personality" is essential.

Spine Examination during COVID-19 Pandemic via Video Consultation. / Telemedizinische Wirbelsäulenuntersuchung während der COVID-19-Pandemie.

INTRODUCTION: During the current COVID-19 pandemic video consultations are increasingly common in order to minimize the risk of infection for staff and patients. The aim of this study was to evaluate the feasibility of a spine examination via video. METHODS: A total of 43 patients were recruited. Each participant underwent a video-based (VB) and a conventional face-to-face (FTF) spine examination. Pain intensity, active range of motion, inspection, a neurophysiologic basic exam and provocations tests were evaluated using video-based and face-to-face methods. RESULTS: The intra-rater reliability (IRR) was measured between both examinations. Good to very good IRR values were obtained in inspection (Kappa between 0,752 und 0,944), active range of motion and basic neurophysiological examination (Kappa between 0,659 und 0,969). Only moderate matches were found in specific provocation tests (Kappa between 0,407 und 0,938). A video-based spine examination is a reliable tool for measuring pain intensity, active range of motion and a basic neurophysiologic exam. CONCLUSION: A basic spine examination during a video consultation is possible. A good agreement of the test results between video-based and face-to-face examination could be found.

Thermic effect on metal body piercing by electrosurgery: An ex vivo study on pig skin and bovine liver.

BACKGROUND: Piercings are placed at different body sites often invisible to medical staff. They may cause additional injuries in trauma and emergency surgery by electro-cautery. OBJECTIVE: To clarify whether electrosurgery will have a direct damaging effect to the skin around a pierced skin area. METHODS: Metallic piercings were fixed at defined distances from the neutral and active electrode on abdominal pig skin. The distance of the active electrode was reduced by 5 mm increments to 0. The respective increases in temperature were determined with a thermal camera. A macroscopic and histological analysis of the area around the piercing to detect thermal damage was carried out. RESULTS: Significant increases in temperature and visible changes in the tissue around the piercing only occurred when the active electrode was in direct contact with the piercing (increase of 47.3∘C). Electro-cautery in distance of 5 to 10 mm to the piercing showed only temperature increases of less than 5∘C. CONCLUSIONS: If metallic piercings are not directly touched by the active electrode and the distance is more than 5-10 mm, no clinically relevant effect is created on the tissue in direct proximity to the piercings by electro-cautery. In an emergency surgery situation, a piercing not fixed in direct proximity to the surgical field may likely be ignored.

Injection therapies for lateral epicondylalgia: a systematic review and Bayesian network meta-analysis.

BACKGROUND: There are many injection therapies for lateral epicondylalgia but there has been no previous comprehensive comparison, based on the Bayesian method. METHODS: The MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for appropriate literature. The outcome measurement was the pain score. Direct comparisons were performed using the pairwise meta-analysis, and network meta-analysis, based on a Bayesian model, was used to calculate the results of all of the potentially possible comparisons and rank probabilities. A sensitivity analysis was performed by excluding low-quality studies. The inconsistency of the model was assessed by means of the node-splitting method. Metaregression was used to assess the relationship between the sample size and the treatment effect. RESULTS: All of the injection treatments showed a trend towards better effects than placebo. Additionally, the peppering technique did not add additional benefits when combined with other treatments. No significant changes were observed by excluding low-quality studies in the sensitivity analysis. No significant inconsistencies were found according to the inconsistency analysis, and metaregression revealed that the sample size was not associated with the treatment effects. CONCLUSIONS: Some commonly used injection therapies can be considered treatment candidates for lateral epicondylalgia, such as botulinum toxin, platelet-rich plasma and autologous blood injection, but corticosteroid is not recommended. Hyaluronate injection and prolotherapy might be more effective, but their superiority must be confirmed by more research. The peppering technique is not helpful in injection therapies.

Malnutrition in geriatric trauma patients: Screening methods in comparison.

BACKGROUND: Malnutrition in geriatric patients is very common and an important outcome factor when treating injuries and fractures. There is actually no clear definition of the term malnutrition or recommendation for a screening method. OBJECTIVE: The purpose of this study was to determine the nutritional status of geriatric trauma patients using different screening procedures. We tested whether the body mass index (BMI) gives indication for malnutrition or if there is a correlation with more specific test procedures. METHODS: The BMI and the data of three specific screening procedures, Subjective Global Assessment (SGA), Nutritional Risk Screening (NRS) and Mini Nutritional Assessment (MNA) were calculated; clinical parameters were registered. RESULTS: There was proof of correlation (p< 0.001) between BMI and SGA; also between BMI and NRS was a significant correlation (p= 0.0004). There was less significant correlation between BMI and MNA (p= 0.05). All three screening methods correlated (p< 0.01). CONCLUSIONS: BMI and subjective statements provide first important information. The SGA not only correlates well with the BMI, but also complements the overall picture with individual information regarding medical history and clinical findings. Other more extensive methods, such as the NRS and the MNA, also show correlation and complement the overall picture with individual information.

Treatments for shoulder impingement syndrome: a PRISMA systematic review and network meta-analysis.

Many treatments for shoulder impingement syndrome (SIS) are available in clinical practice; some of which have already been compared with other treatments by various investigators. However, a comprehensive treatment comparison is lacking. Several widely used electronic databases were searched for eligible studies. The outcome measurements were the pain score and the Constant-Murley score (CMS). Direct comparisons were performed using the conventional pair-wise meta-analysis method, while a network meta-analysis based on the Bayesian model was used to calculate the results of all potentially possible comparisons and rank probabilities. Included in the meta-analysis procedure were 33 randomized controlled trials involving 2300 patients. Good agreement was demonstrated between the results of the pair-wise meta-analyses and the network meta-analyses. Regarding nonoperative treatments, with respect to the pain score, combined treatments composed of exercise and other therapies tended to yield better effects than single-intervention therapies. Localized drug injections that were combined with exercise showed better treatment effects than any other treatments, whereas worse effects were observed when such injections were used alone. Regarding the CMS, most combined treatments based on exercise also demonstrated better effects than exercise alone. Regarding surgical treatments, according to the pain score and the CMS, arthroscopic subacromial decompression (ASD) together with treatments derived from it, such as ASD combined with radiofrequency and arthroscopic bursectomy, showed better effects than open subacromial decompression (OSD) and OSD combined with the injection of platelet-leukocyte gel. Exercise therapy also demonstrated good performance. Results for inconsistency, sensitivity analysis, and meta-regression all supported the robustness and reliability of these network meta-analyses. Exercise and other exercise-based therapies, such as kinesio taping, specific exercises, and acupuncture, are ideal treatments for patients at an early stage of SIS. However, low-level laser therapy and the localized injection of nonsteroidal anti-inflammatory drugs are not recommended. For patients who have a long-term disease course, operative treatments may be considered, with standard ASD surgery preferred over arthroscopic bursectomy and the open surgical technique for subacromial decompression. Notwithstanding, the choice of surgery should be made cautiously because similar outcomes may also be achieved by the implementation of exercise therapy.

Fractures of the ankle joint: investigation and treatment options.

BACKGROUND: Ankle fractures are common, with an incidence of up to 174 cases per 100 000 adults per year. Their correct classification and treatment are of decisive importance for clinical outcome. METHOD: Selective review of the literature. RESULTS: Ankle fractures are initially evaluated by physical examination and then by x-ray. They can be classified according to either the AO Foundation (Association for the Study of Internal Fixation) or the Weber classification. Dislocated fractures need emergency treatment with immediate reduction; this is crucial for the prevention of hypoperfusion and nerve damage. Weber A fractures can usually be treated conservatively, while Weber B and C fractures are usually treated with surgery. An evaluation of the stability of the syndesmosis is important for anatomical reconstruction of the joint. Wound hematoma and wound-edge necrosis are the most common complications, and the postoperative infection rate is 2%. Up to 10% of patients develop ankle arthrosis over the intermediate or long term. CONCLUSION: With properly chosen treatment, a good clinical outcome can be achieved. The long-term objective is to prevent post-traumatic ankle arthrosis. The evidence level for optimal treatment strategies is low.

Extracellular micronutrient levels and pro-/antioxidant status in trauma patients with wound healing disorders: results of a cross-sectional study.

BACKGROUND: Disorders in wound healing (DWH) are common in trauma patients, the reasons being not completely understood. Inadequate nutritional status may favor DWH, partly by means of oxidative stress. Reliable data, however, are lacking. This study should investigate the status of extracellular micronutrients in patients with DWH within routine setting. METHODS: Within a cross-sectional study, the plasma/serum status of several micronutrients (retinol, ascorbic acid, 25-hydroxycholecalciferol, α-tocopherol, ß-carotene, selenium, and zinc) were determined in 44 trauma patients with DWH in addition to selected proteins (albumin, prealbumin, and C-reactive protein; CRP) and markers of pro-/antioxidant balance (antioxidant capacity, peroxides, and malondialdehyde). Values were compared to reference values to calculate the prevalence for biochemical deficiency. Correlations between CRP, albumin and prealbumin, and selected micronutrients were analyzed by Pearson's test. Statistical significance was set at P < 0.05. RESULTS: Mean concentrations of ascorbic acid (23.1 ± 15.9 µmol/L), 25-hydroxycholecalciferol (46.2±30.6 nmol/L), ß-carotene (0.6 ± 0.4 µmol/L), selenium (0.79±0.19 µmol/L), and prealbumin (24.8 ± 8.2 mg/dL) were relatively low. Most patients showed levels of ascorbic acid (<28 µmol/L; 64%), 25-hydroxycholecalciferol (<50 µmol/L; 59%), selenium (≤ 94 µmol/L; 71%) and ß-carotene (<0.9 µmol/L; 86%) below the reference range. Albumin and prealbumin were in the lower normal range and CRP was mostly above the reference range. Plasma antioxidant capacity was decreased, whereas peroxides and malondialdehyde were increased compared to normal values. Inverse correlations were found between CRP and albumin (P < 0.05) and between CRP and prealbumin (P < 0.01). Retinol (P < 0.001), ascorbic acid (P < 0.01), zinc (P < 0.001), and selenium (P < 0.001) were negatively correlated with CRP. CONCLUSIONS: Trauma patients with DWH frequently suffer from protein malnutrition and reduced plasma concentrations of several micronutrients probably due to inflammation, increased requirement, and oxidative burden. Thus, adequate nutritional measures are strongly recommended to trauma patients.

Correlation of pull-out strength of cement-augmented pedicle screws with CT-volumetric measurement of cement.

BACKGROUND: Cement augmentation of pedicle screws increases fixation strength in an osteoporotic spine. This study was designed to determine the cement distribution and the correlation between the pull-out strength of the augmented screw and the cement volume within polyurethane (PU) foam. METHODS: Twenty-eight cannulated pedicle screws (6×45 mm) (Peter Brehm, Erlangen, Germany) with four holes at the distal end of the screw were augmented with the acrylic Stabilit ER Bone Cement Vertebral Augmentation System (DFine Inc., San Jose, CA, USA) and implanted into open-cell rigid PU foam (Pacific Research Laboratories, Vashon Island, WA, USA) with a density of 0.12 g/cm3, resembling severe osteoporosis. Volumetric measurement of the cement with consideration of the distribution around the screws was done with multislice computed tomography scan (Somatom Definition, Siemens, Erlangen, Germany). Pull-out strength was tested with a servohydraulic system (MTS System Corporation, Eden Prairie, MN, USA), and nonaugmented screws served as control. Pearson's correlation coefficient with significance level α=0.05 and one-way analysis of variance test were used. RESULTS: We found a high (r=0.88) and significant (p<0.01) correlation between the cement volume and the pull-out strength, which increased by more than 5-fold with a volume of 3 ml. The correlation appeared linear at least up to 4 ml cement volume and failure always occurred at the cement-bone interface. The cement distribution was symmetric and circular around the most proximal hole, with a distance of 14 mm from the tip, and nearly 90% of the cement was found 6 mm distal and cranial to it. The 95% confidence interval for the relative amount of cement was 37%-41% within 2 mm of the most proximal hole. CONCLUSION: Compared with the control, a cement volume between 2.0 and 3.0 ml increased the pull-out strength significantly and is relevant for clinical purposes, whereas a volume of 0.5 ml did not. A cement volume beyond 3.0 ml should further increase the pull-out strength because the correlation was linear at least up to 4.0 ml, but the possibility of in vivo cement leakage with increasing volume has to be considered. Pressure-controlled cement application might be a tool to avoid this complication. The cement almost completely penetrated the most proximal perforation.

Image and diagnosis quality of X-ray image transmission via cell phone camera: a project study evaluating quality and reliability.

INTRODUCTION: Developments in telemedicine have not produced any relevant benefits for orthopedics and trauma surgery to date. For the present project study, several parameters were examined during assessment of x-ray images, which had been photographed and transmitted via cell phone. MATERIALS AND METHODS: A total of 100 x-ray images of various body regions were photographed with a Nokia cell phone and transmitted via email or MMS. Next, the transmitted photographs were reviewed on a laptop computer by five medical specialists and assessed regarding quality and diagnosis. RESULTS: Due to their poor quality, the transmitted MMS images could not be evaluated and this path of transmission was therefore excluded. Mean size of transmitted x-ray email images was 394 kB (range: 265-590 kB, SD ± 59), average transmission time was 3.29 min ± 8 (CI 95%: 1.7-4.9). Applying a score from 1-10 (very poor - excellent), mean image quality was 5.8. In 83.2 ± 4% (mean value ± SD) of cases (median 82; 80-89%), there was agreement between final diagnosis and assessment by the five medical experts who had received the images. However, there was a markedly low concurrence ratio in the thoracic area and in pediatric injuries. DISCUSSION: While the rate of accurate diagnosis and indication for surgery was high with a concurrence ratio of 83%, considerable differences existed between the assessed regions, with lowest values for thoracic images. Teleradiology is a cost-effective, rapid method which can be applied wherever wireless cell phone reception is available. In our opinion, this method is in principle suitable for clinical use, enabling the physician on duty to agree on appropriate measures with colleagues located elsewhere via x-ray image transmission on a cell phone.

Continuing conservative care versus crossover to radiofrequency kyphoplasty: a comparative effectiveness study on the treatment of vertebral body fractures.

BACKGROUND: There is controversy about how to treat vertebral fractures. Conservative care is the default approach. Radiofrequency kyphoplasty uses ultrahigh viscosity cement to restore spinal posture and stabilize the fracture. The aims of this study were to compare radiofrequency kyphoplasty to conservative care and assess the usual algorithm of starting all patients on conservative care for 6 weeks before offering surgery. METHODS: Elderly patients with painful osteoporotic vertebral compression fractures were all treated with 6 weeks of conservative care (analgesics, bracing, and physiotherapy). They were then offered the choice of continuing conservative care or crossing over to radiofrequency kyphoplasty, at 6 and 12 weeks. Clinical success was defined as: (1) VAS pain improvement ≥2, (2) final VAS pain ≤5, (3) no functional worsening on ODI. RESULTS: After the initial 6 weeks of conservative care, only 1 of 65 patients met the criteria for clinical success, and median VAS improvement was 0. After 12 weeks of conservative care, only 5 of 38 patients met the criteria for clinical success, and median VAS improvement was 1. At the 6-week follow-up after radiofrequency kyphoplasty, 31 of 33 surgery patients met the criteria for clinical success, and median VAS improvement was 5. CONCLUSION: For the vast majority of patients with a VAS ≥5, conservative care did not provide meaningful clinical improvement. In contrast, nearly all patients who underwent radiofrequency kyphoplasty had rapid substantial improvement. Surgery was clearly much more effective than conservative care and should be offered to patients much sooner.

Time to wound closure in trauma patients with disorders in wound healing is shortened by supplements containing antioxidant micronutrients and glutamine: a PRCT.

BACKGROUND & AIMS: : We hypothesize that wound closure in trauma patients with disorders in wound healing is accelerated by supplementation of antioxidant micronutrients and glutamine. METHODS: In a randomized, double-blind, placebo-controlled trial, 20 trauma patients with disorders in wound healing were orally supplemented with antioxidant micronutrients (ascorbic acid, α-tocopherol, ß-carotene, zinc, selenium) and glutamine (verum) or they received isoenergetic amounts of maltodextrine (placebo) for 14 days. Plasma/serum levels of micronutrients, glutamine, and vascular endothelial growth factor-A (VEGF-A) were determined before and after supplementation. In the wound, several parameters of microcirculation were measured. Time from study entry to wound closure was recorded. RESULTS: Micronutrients in plasma/serum did not change except for selenium which increased in the verum group (1.1 ± 0.2 vs. 1.4 ± 0.2 µmol/l; P = 0.009). Glutamine decreased only in the placebo group (562 ± 68 vs. 526 ± 55 µmol/l; P = 0.047). The prevalence of hypovitaminoses and the concentration of VEGF-A did not change. Considering microcirculation, only O(2)-saturation decreased in the placebo group (56.7 ± 23.4 vs. 44.0 ± 24.0 [arbitrary units]; P = 0.043). Wound closure occurred more rapidly in the verum than in the placebo group (35 ± 22 vs. 70 ± 35 d; P = 0.01). CONCLUSIONS: Time to wound closure can be shortened by oral antioxidant and glutamine containing supplements in trauma patients with disorders in wound healing.

Health status as an important outcome factor after hemiarthroplasty.

The goal of this study was to determine functional results of hemiarthroplasty for 3- and 4-part proximal humeral fractures in elderly patients and to analyze factors affecting the outcome. Thirty-eight consecutive shoulders were treated with hemiarthroplasty after proximal humeral fracture. Two groups of patients with different health status were classified. Group I consisted of patients with 2 or less comorbidities and a maximum of 2 medications at the time of injury. Patients in group II had 3 or more comorbidities with a minimum of 3 medications at the time of injury. The mean of the absolute Constant score in group I was 41, compared to 27 in group II (P < .05). Furthermore, compliance of the patient and regular physiotherapy proved to be important prognostic factors. If primary hemiarthroplasty is not likely to be successful with a low functional score, this surgical procedure should be reconsidered especially in patients with more than three comorbidities.

Malleolus externus plasty for joint reconstruction in fibular aplasia: preliminary report of a new technique.

The instability of the upper and the lower ankle joint represents a serious problem in patients with fibular aplasia. None of the previous techniques demonstrated at least sufficient results. In this report we present a new technique of malleolus externus plasty applied in a 5 1/2-year-old boy with fibular aplasia (type II according to Coventry and Johnson or type Ib according to Achtermann and Kalamchi) with a 6 cm length deficiency of the lower leg and 1 cm of the upper leg. Furthermore, he showed a tibial antecurvation deformity of 20 degrees, a fourth ray foot with adduction deformity of the hindfoot, cutane syndactyly D 2-4, and a hallux varus. This new technique works on the following principle. A triangular iliac crest transplant is implanted with an apophysis and the annexing fascia glutealis, including the osseous part of the transplant, in the lateral distal tibia in a way that the growing apophyseal part lays distally covering the lateral talus. Gluteal fascia annexed to the apophysis was used for the reconstruction of a lateral tendon. Using a ring fixator the transplant is fixed and coincidentally the lower leg lengthened and the axis corrected. The axis deformity and the leg-length deficiency of 7 cm were equalized. The fixator could be removed after 6 months. Radiologically, an entire integration of the iliac crest transplant was found. Magnetic resonance imaging showed it had sufficient circulation. The reexamination 2.5 years later demonstrated a simultaneous growth of the malleolus externus and the distal tibia and stable ankle joints with sufficient mobility and full weight-bearing capability. For support of the foot the boy uses ready-made shoes with curved arch supports. In conclusion, using this new technique an individually adapted lateral malleolus with growth-potential can be constructed that stabilizes the foot and the ankle joints. Thus, reluxations of the foot specifically in relation to lengthening of lower legs can be avoided with concurrent preservation of the range of movement of the ankle joint.

Mechanically induced electrical potentials of articular cartilage.

While there is increasing evidence that chondrocytes are affected by mechanically induced stimuli, endogenous force-related electrical potentials within articular cartilage have been so far observed only in-vitro. Using a porcine ex-vivo model (German Land Race), 8 knee joints were explanted and exposed to mechanical force (up to 800 N) using a special device. Electrodes were inserted into the cartilage matrix. With an amplifier and an A/D transducer the changes of electrical voltage between the electrodes as well as those of the force were recorded online and simultaneously on a computer. Additionally, we located one pair of electrodes on the surface of the cartilage tissue to detect electrical fields outside the cartilage tissue. In relation to the applied force we observed that electrical potentials derived from inside and outside the articular cartilage showed a correspondence. When an alternating force with an amplitude of 360 N and a frequency of about 0.2 Hz was periodically applied, we measured peak amplitudes ranging from 2.1 to 5.5 mV within the cartilage tissue with electrical negativity within the weight bearing area of the cartilage tissue. The measured voltages depended on the applied force, the location of the electrodes, and on anatomical variations. We found an almost linear relation between the magnitude of the applied force and the recorded voltage. With the help of the electrodes located outside and within the cartilage tissue, we were able to show that force dependent fields are generated inside the cartilage. There are several theories explaining the origin of these electrical phenomena, many of them focusing on the negative charges of the proteoglycans in relation to the flow of interstitial fluid and ions under compression. However, the consequences of these phenomena are yet not clear.