Horse-related injury patterns: a single center report.

BACKGROUND: For ages, humankind and horses have been closely related to occupational and recreational activities. The dangers of engaging with horses have been previously reported. Among sporting activities, horse riding is well-known for its risks. Despite multiple recommendations to wear protective gear, horse-related activities still comprise the risk of severe injuries. This study aimed to examine: (1) if specific mechanisms are correlated to particular injury patterns and (2) if injury types are related to patient demographics. METHODS: From one level I trauma center, between July 2019 and July 2022 (3 years) all emergency reports and discharge letters were retrospectively reviewed by full-text search regarding horse-related injuries. Patient demographics, body mass index, trauma mechanism, injury types, and initiated treatment were extracted from medical records and analyzed. RESULTS: During the study period, 95 patients with 99 horse-related injuries were included. The overwhelming majority of the patients was female (93.7%). Age averaged 35.3 years (range 6 to 71). BMI was 23.6 kg/m2. Inpatient treatment was required in 60.6%. Length of hospital stay averaged 10 days. Surgical treatment was performed in 55 patients (55.6%). Open reduction and internal fixation was the most common procedure (74.5%). Trauma mechanism was fall from a horse followed by being hit by a horse (60.6% and 23.2%, respectively). Injured upper extremities counted up for 52.5% followed by spinal and pelvic injuries (23.2%). Spinal and pelvic injuries were related to fall from a horse (p < 0.001). Injuries to the lower extremities were predominantly caused by a kick of the horse when the rider was unmounted (p = 0.001) and negatively related to a fall from a horse (p = 0.002). Ten patients got their fingers tangled while holding the reins and suffered from injuries to the upper extremity (p < 0.001). Three of them required an amputation (30%). CONCLUSION: Despite the fact that patients are young and healthy, horse related injuries must not be underestimated. In our study, almost two-thirds of the patients required inpatient treatment and 50% underwent surgery. We could show that patient age was related to injury severity according to the Abbreviated Injury Scale (AIS). Spinal and pelvic injuries were significantly related to a fall from a horse with a significantly greater trauma impact according to the AIS. Therefore, these severe entities need to be ruled out in such events. Accidents caused by holding the reins, may result in serious injuries to the hand with 30% requiring an amputation. Doctors need to be aware of possible horse-related injury patterns to reduce morbidity.

[Precise sacroiliac joint screw insertion without computed tomography, digital volume tomography or navigation systems]. / Sichere Verschraubung des Iliosakralgelenks ohne intraoperative Computertomographie, digitale Volumentomographie oder Navigationssystem.

OBJECTIVE: Improvement of sacroiliac positioning of screws by detailed preoperative planning with a DICOM (Digital Imaging and Communications in Medicine-the international standard to store and process medical imaging information) workstation in the absence of advanced technical facilities like intraoperative computer tomography (CT), digital volume tomography (DVT) or a navigation system. INDICATIONS: Mono- or bilateral non- or minor displaced, longitudinal sacral fractures type Denis I and II and pelvic ring fractures (Orthopedic Trauma Association) OTA type B possibly in combination with a ventral procedure. CONTRAINDICATIONS: Displaced sacral fractures type Denis II and III, fractures with central comminution and circulatory unstable patients to be stabilized in the context of emergency care. SURGICAL TECHNIQUE: Preoperative calculation of virtual conventional standard view X­rays with the CT dataset using common DICOM software (e.g., Siemens via® or Sectra®). Typical landmarks such as screw entry point and end point are projected into the virtual X­rays. Intraoperative navigation is performed by comparing the virtual standard views with fluoroscopic images of the C­arm, thereby, simplifying the operative procedure. POSTOPERATIVE MANAGEMENT: Postoperative CT scan, pain adapted partial weight bearing and X­rays of the pelvic ring after 6 and 12 weeks. RESULTS: Over a 13 month period, an orthopedic surgeon inserted 26 sacroiliac screws in 19 patients utilizing the described method. Postoperative CT scans revealed that all except three screws were precisely positioned without any bone perforation. Of these three screws one had a grade one perforation and two had a grade two perforation according to Smith. No revision was necessary and no neurological deficits were detected. The operating time was on average 33 min and duration of radiation 3.8 min.

[Acute exacerbation of chronic CLL with multiple pathological fractures : A rarity]. / Akute Exazerbation einer chronischen CLL mit multiplen pathologischen Frakturen : Eine Seltenheit.

Chronic lymphatic leukaemia (CLL) is one of the most common leukaemic diseases in middle Europe. Pathological fractures are rare findings in patients with CLL. The diagnosis of CLL is in most cases an incidental finding as it often stays asymptomatic for years. This article presents an interesting case of a 65-year-old male patient with known asymptomatic CLL for 5 years and fractures of the proximal femur and proximal radius after trauma. During the hospital stay the patient suffered multiple pathological fractures with histological findings of bony infiltration of the CLL and an acute phase, which was treated by combination chemotherapy.

[Lumbopelvic stabilization for bilateral lumbosacral instabilities: indications and techniques]. / Lumbopelvine Stabilisierung bei bilateraler lumbosakraler Instabilität: Indikationen und Technik.

BACKGROUND: Bilateral lumbopelvic instabilities are rare; for the affected patients, however, they mean a severe reduction in quality of life. Optimal results can only be achieved with a well-adapted therapy algorithm that balances surgery and non-surgical procedures. OBJECTIVES: The present article addresses the indications, strategy, and techniques of bilateral lumbopelvic fixation in the operative treatment of bilateral lumbopelvic injuries and review of the literature and personal experience. RESULTS: The overall incidence of lumbosacral instabilities is low and mainly caused by high energy trauma, osteoporotic insuffiencies (e.g., primarily or secondary after long segment lumbar instrumentation), and tumors. Dramatic soft tissue injuries can occur in addition to hidden neurological impairments, and therefore it is important to diagnose and evaluate all concomitant comorbidities. The keys to success are gaining stability in the lumbosacral junction possibly combined with neuronal decompression and meaningful coordination of all disciplines, certainly challenged by finding the correct moment for surgery which is between 2 days and 2 weeks. Based on the superficial anatomy of the bony structures in the lumbosacral junction, the surgical approach has to match the pathology and should be tissue saving. CONCLUSIONS: Treatment of bilateral lumbopelvic instabilities requires an accurate examination, sophisticated therapy protocol, and a multidisciplinary approach. Surgery with a bilateral lumbopelvic fixation combined with neuronal decompression is an adequate treatment that creates early bony stability, thus, promising functional weight-bearing mobilization.

[The pressure-sensitive swelling in the knee as a sign for a monoclonal gammopathy of undetermined specificity (MGUS)]. / Die druckdolente Schwellung in der Kniekehle als Wegweiser einer monoklonalen Gammopathie unklarer Spezifität (MGUS).

AL amyloidosis (AL-A) is seen in about 6-15 % of patients with multiple myeloma. In contrast, the sporadic occurrence of AL-A is a rarity. The presence of amyloid is often found in the respiratory tract followed by the lung, the eyelids, the skin and the lower urinary tract, while the presence in soft tissues or bone is rather uncommon. We here describe a 71-year-old woman who presented with a pressure-sensitive swelling in the left knee at our hospital. The clinical examination on admission showed a tumourous alteration of the popliteal soft tissues without any signs of neurological deficits. However, the range of motion (ROM) of the left knee was restricted with 0-0-100 degrees for extension and flexion. A dialysis-dependent renal insufficiency, heart insufficiency with the necessity of permanent anticoagulation and glaucoma were noted as pre-existing illnesses. Further diagnostic examinations including ultrasound and magnetic resonance imaging (MRI) of the left knee revealed a solid tumourous structure with a radiological suspicion of pigmented villonodular synovitis. A complete surgical extirpation of the tumourous structure was performed. The further performed diagnostic examinations including histological and immunohistochemical analyses showed evidence of an AL-A tumour. A monocloncal gammopathy of unknown specificity (MGUS) was detected as an origin for the AL-A. This case underscores the necessity of complete extirpation and histological and immunohistochemical analyses of any soft tissue tumour. Possible previously existing rare malignant diseases can be detected only in this way.

Characteristics and differences in necrotizing fasciitis and gas forming myonecrosis: a series of 36 patients.

BACKGROUND AND AIMS: Necrotizing fasciitis (NF) and gas forming myonecrosis (GFM), both being subtypes of necrotizing soft tissue infection (NSTI), are life threatening conditions sharing certain similarities. Despite the necessity of early and radical surgical debridement in necrotizing infections, the distinction between these entities is of clinical relevance since gas forming myonecrosis in a number of cases results from an underlying abdominal cause and the focus of infection can be missed. This study was to evaluate the incidence and risk factors as well as the mortality rate in patients with NSTI and GFM. MATERIAL AND METHODS: All patients with NSTI treated in the authors' hospital between January 2005 and Decem-ber 2009 were enrolled in the study. Medical records, histological slides, microbiological and laboratory parameters as well as Computerized Tomography (CT) and magnetic resonance imaging (MRI) scans were reviewed for all patients. Differences between NF and GFM regarding hospital stay, number of surgical interventions and pre-existing comorbidities as well as mortality rate were analyzed. The laboratory risk factor for necrotizing fasciitis (LRINEC) score was calculated in all patients on admission. RESULTS AND CONCLUSIONS: Thirty patients (17 female, 13 male) with necrotizing fasciitis with a mean age of 55 years (SD 15.5) were included in the study. There was no statistically significant difference between survivors and deceased patients comparing the LRINEC score (n.s.). Patients with necrotizing fasciitis secondarily involving the trunk had a significantly higher mortality rate (OR 11.2; 95% CI=1.7-72.3). In the majority of cases (12 cases), minor skin lesions were identified as the site of origin. Amongst all necrotizing soft tissue infections six patients (female n=3; male n=3) with a mean age of 61.5 years (SD 12.2) with non-clostridial gas forming myonecrosis were identified. Three patients had a history of malignancy and in three patients the infection was secondary to major surgery. The mean LRINEC score was 8.5 (SD 1). Three patients (50%) died due to GFM. Early diagnosis and appropriate intervention is critical to provide accurate treatment decisions. Eradicating the differing primary sources of infection in GFM and NF will have a positive impact on outcome.

[Underdiagnosed disco-ligamentous lesion in the cervical spine of a paraglider]. / Übersehene disko-ligamentäre Zerreißung an der HWS bei einem Gleitschirmflieger.

INTRODUCTION: Paragliding is an increasingly popular airborne sport with numerous associated injuries. We here describe the case of an experienced paraglider who, after a fall from 15 meters, presented with an initially underdiagnosed disco-ligamentous lesion of the cervical spine. PATIENT AND METHOD: We report on a 51-year-old male paraglider, who was referred to our hospital four days after a fall from 15 meters. Initial treatment was performed in a regional hospital. The performed clinical and radiological examinations including computerized tomography showed, besides a fracture of the radius, no further abnormalities. RESULTS: The patient was discharged home four days after injury. Due to persistent pain in the cervical spine and parasthesia, the patient was referred to the practicing orthopaedic surgeon. The performed MRI and CT including the sagittal and coronal planes showed a disco-ligamentous lesion of the cervical spine. The patient was transferred immediately to our hospital for surgical treatment. The initial existing neurological symptoms resolved postoperatively and the patient was discharged home in a well condition. DISCUSSION: Injuries of the cervical are extremely rare in paragliders. Nevertheless, this case underscores the importance of adequate clinical and radiological examinations. We report the case of our patient to increase awareness among physicians and training staff working in emergency rooms.

[Paraplegia after isolated rupture of the spinal cord - a rare injury]. / Querschnittslähmung nach isolierter Rückenmarksruptur - eine seltene Verletzung.

INTRODUCTION: Complex vertebral fractures can lead to injury of the spinal cord with resulting paraplegia. High-speed accidents are common causes, especially in younger patients. Malignant or inflammatory processes play an important role in the elderly. Less common reasons for a spinal cord injury are congenital malformations. We here report about a 17-year-old patient who suffered from paraplegia after an isolated rupture of the spinal cord without an injury of the vertebral bodies, intervertebral disc or ligamentous structures. This type of injury has not been reported in the literature before. PATIENT AND METHOD: We report about a 17-year-old patient, referred to our hospital, presenting with lumbal paraplegia after a high-speed accident 8 days prior to admission. After initial stabilisation of the polytraumatised patient, he was referred to our hospital for further treatment. RESULTS AND CONCLUSION: The radiological examination showed a bilateral acetabular fracture, a right anterior pelvic ring fracture and shaft fractures of the left humerus and right femur. Furthermore, the spinal cord at thoracic level 10/11 was ruptured. Interestingly, there was no injury of the vertebral bodies, intervertebral disc or ligamentous structures. A tethered cord as a possible anatomic variation could be excluded in this case by MRI. However, anatomic variations could be the reason for this injury and should be kept in mind.

[Arm wrestling injuries--report on 11 cases with different injuries]. / Verletzungen nach Armdrücken--Bericht über 11 Patienten mit unterschiedlichen Verletzungsmustern.

INTRODUCTION: Arm wrestling may cause severe injuries. Various injuries after arm wrestling have been reported in the literature, whereas the most common injury is the humeral shaft fracture. In this context we report on eleven cases with different injuries during arm wrestling. MATERIAL AND METHODS: All patients were analyzed using a standardized questionnaire. The effect of drugs, pre-existing conditions and injuries as well as sport activities were examined. Furthermore we report about a 24 year old patient who sustained a radial shaft fracture which has not been reported in the literature yet. RESULTS: 8 patients suffered from a fracture. The humerus was the most affected bone in 7 cases. 3 patients had a muscle strain, whereas in all 3 cases the patients were regularly sportive active and warmed-up be for the injury. Ten patients were reintegrated into the previous job after an average time period of 6 weeks. One patient was out of work. CONCLUSIONS: Regular sport activity and the muscle strength are important factors for the injury intensity. Further studies are necessary to confirm this theory.

[The risk of nerve lesions in hip alloarthroplasty]. / Das Risiko der Nervenläsion in der Hüftendoprothetik.

AIM: Repeated luxations, periprosthetic fractures, infections, and nerve palsies are the most frequent complications of hip alloarthroplasty. Paresis acquired during elective implantation entails considerable restrictions in the quality of life. The risk of sustaining a nerve injury depends upon the initial clinical situation, cases of planned leg lengthening in patients with hip dysplasia and high luxations being particularly at risk. METHOD: A Medline search was conducted using the query "nerve palsies during hip prosthesis implantation", yielding 126 publications, of which 18 were used to predict the risk of nerve palsies in cases with simultaneous leg lengthening during total hip arthroplasties according to different preconditions. RESULTS: The risk for an acquired nerve lesion during hip alloarthroplasty in arthritis was 0.5 %. In cases of hip dysplasia (with no or moderate leg lengthening during the procedure), the risk was increased to 2.3 %. An even higher risk of 3.5 % was found in cases of revision surgery. According to the literature, the risk of nerve palsies in cases of continuous leg lengthening before THA is raised to 5.9 % with a linear correlation between the amount of leg lengthening and rate of nerve palsies. CONCLUSION: Neural lesions during single-stage leg lengthening of less than 3 cm in hip alloarthroplasty are uncommon. More extensive lengthening can be achieved with continuous procedures, which should be conducted under clinical monitoring of the peripheral nerves to avert possible nerve injury.

[Augmentive plate fixation in femoral non-unions after intramedullary nailing. Strategy after unsuccessful intramedullary nailing of the femur]. / Die additive Plattenosteosynthese bei Femurpseudarthrosen nach intramedullärer Stabilisierung.

INTRODUCTION: Intramedullary nailing is a standard procedure to treat femoral fractures in patients without polytrauma. Nevertheless, non-union in femoral fractures is a common complication with an incidence of 12.5 percent, mostly arising for mechanical reasons. The aim of this study is to find out whether the increase of stability through an augmentive plate fixation (if necessary with bone grafting) with leaving the nail in situ is adequate to treat the non-union successfully. MATERIALS AND METHODS: Between January 2001 and July 2005 32 patients with femoral non-unions after intramedullary nailing were treated in our hospital. Mean age was 42 years (min 22 and max 75). Distribution of gender was about (2/3) male and (1/3) female. In 17 patients the fractures were localised in the middle of the femur shaft, in 8 patients in the proximal third and in 7 in the distal third. The results were evaluated retrospectively by reviewing the patients' records and X-ray-films. If the success of treatment was not clearly determined through the records the patients were contacted by telephone and, if required, invited for a personal examination. RESULTS: In 29 cases our procedure led primarily to a definite consolidation of the non-union within 5 months on average. The nail was changed eight times, in three patients an additional operation was necessary due to screw breakage. Bone grafting was performed in 27 cases. The overall group included 24 non-smokers and 8 smokers. CONCLUSION: If indicated, the herein demonstrated procedure with an augmentive plate fixation while leaving the nail in situ is simple and safe. Although the intramedullary canal is potentially affected through the initial nailing, the healing of femoral non-unions was observed in the majority of cases in spite of the additional extramedullary approach for plating and bone grafting.

[Long-term results after acetabular fractures with respect to heterotopic ossifications]. / Langzeitergebnisse nach Azetabulumfrakturen unter Berücksichtigung von heterotopen Ossifikationen.

BACKGROUND: Arthrosis, necrosis of the femoral head and heterotopic ossification (HO) tend to decline the outcome of acetabular fractures despite of good fracture reduction. In this study functional outcome and degree of HO were analyzed due to fracture type and surgical approach. The aim of this study is to delineate wether minimization of soft tissue damage increases the functional outcome. PATIENTS AND METHODS: 55 patients with surgically treated acetabular fractures (mean age: 40.4 (20-81) years, male 43, female 12) where retrospectively evaluated with a mean follow-up of 7.7 (4.4-12.3) years. Fractures were classified according to the Orthopaedic Trauma Association (OTA), functional outcome was scored by D'Aubigné-Postel and the degree of HO was defined by Brooker's classification. RESULTS: Following the OTA the distribution of fractures was: A-24 (44 %), B-23 (42 %) and C-8 (15 %). Mean D'Aubigné Index (max. 18 points) was 15.2, distributed to fracture type: A-15.9, B-15.0 and C-13.6. 32 % of all heterotopic ossifications were classified as Brooker 0, 10 % as Brooker 1, 29 % as Brooker 2 and Brooker 3 each, whereas Brooker 4 ossifications were not observed. 2/3 of the severe ossifications were observed using extended approaches or in case of type C fractures. The iliofemoral approach showed the tendency of fewer ossifications compared to extended approaches. CONCLUSION: Decrease of soft tissue damage during acetabular surgery plays an important role to improve outcome. Due to the higher risk of wrong implant position and insufficient reduction using a soft tissue sparing approach, we recommend a CT scan postoperatively to evaluate reduction and osteosynthesis.

[Pelvic stabilization in cases of septic instability. Triangular osteosynthesis in case of infection related vertical pelvic ring instability]. / Beckenstabilisierung bei septischer Instabilität. Vordere und hintere Beckenringarthrodese bei septisch bedingter vertikaler Instabilität.

The combination of transiliac screws and lumbopelvic distraction osteosynthesis is usually an appropriate procedure to treat vertical pelvic ring instabilities under the condition of full weight bearing. In this case, due to the extent of septic destruction of the dorsal portion of the iliac bone, the common triangular fixation method using conventional pedicle screws was not possible. Using the transiliac dorsoventral screw position with special long screws, we achieved high mechanical triangular stability sufficient for pelvic ring fusion despite the large bony defect.

[Complex fractures of the humeral head: which long-term results can be expected?]. / Komplexe Brüche des Oberarmkopfes: Welche Langzeitresultate sind zu erwarten?

BACKGROUND: Although improved techniques of internal fixation and prosthetic replacement were introduced successfully in the field of operative fracture care, treatment of complex fractures of the proximal humerus also involving the humeral head remains to be a challenge to the trauma surgeon. We therefore investigated clinical and radiological long-term results after humeral head preserving procedures. METHODS: 41 patients with a three or four part fracture of the humeral head were evaluated on average 6.6 years (min. 4.4 y; max. 9.0 y) after the trauma. The evaluation was based on the Constant- and HSS score clinically and on the Neer score radiologically. Nine patients were treated conservatively (group A), 13 patients had primarily an operative treatment (group B) and another 19 were operated upon after failure of conservative means. 24 of the patients were female and 17 male, with an average age of 52 years (min. 14.4 y; max. 71.2 y). According to Neers 's fracture classification of humeral head fractures we saw 14 type IV, 25 times a combination of type IV and V and in another 2 cases a type VI fracture. RESULTS: In group A (conservative) the Constant score showed on average 82.0 points for the injured and 95.3 points for the contralateral shoulder, the HSS score revealed 73.6 points and Neer's x-ray score 5.6 points. Group B (operated) showed also good results on average according to a Constant score of 72.1 points (fractured humerus) compared with 98.1 points of the contralateral shoulder. HSS score was 64.7 points. The radiological results reached 4.0 points. Group C (conservatively failed, secondary operation) achieved 68.2 points for the injured side and 95.8 points for the contralateral side according to Constant and 59.5 points according to HSS score. The x-ray evaluation showed 5.3 points. Fracture type did not influence the outcome in any of the groups. There was no humeral head necrosis in group A, one in group B (2.4 %) and four in group C (9.8 %). CONCLUSION: These data show that regarding to clinical and radiological long-term results also complex fractures of the humeral head should be treated by head preserving procedures.

[Primary hemiarthroplasty after complex fracture of the humeral head--functional late results]. / Primäre Hemiprothetik nach komplexem Oberarmkopfbruch--Funktionelle Spätergebnisse.

UNLABELLED: Treatment of complex fractures of the humeral head remains an obviously unsolved problem. Under consideration of the problems of head preserving methods, the development of the last years tended towards the hemiprosthetic replacement. As the discussion about the methods and implants continues to be controversial, long-term results of Neer-II-replacement of humeral head in own trauma cases are presented here. PATIENTS AND METHODS: 46 patients were investigated, in whom a cemented Neer II hemiprosthesis was implanted between 1983 and 1996 due to complex fracture patterns. Median age was 60.2 years, 74 % of patients were female. 59 % had a luxation fracture type Neer VI, 22 % presented a concomitant nerval lesion. Follow up was performed 5 years on average after the operation. 38 patients were investigated clinically according the score of Constant and Murley, 36 had a x- ray control. Additionally an individual questionnaire was completed by 46 patients. RESULTS: Average Constant-score was 66.2 points, whereas in 76.3 % a satisfactory or better result was achieved. In 23.9 % the outcome was poor. In one patient (2.2 %) explantation of the hemiprosthesis and shoulder fusion due to pain was necessary. Conditions for a good result were a patient aged 50 years and younger (75.9 pts. versus 64.2 pts.), an early hemiprosthetic replacement within 4 weeks after the trauma (71.7 pts. versus 55.3 pts.) and a patient without an earlier operation and nerval lesion (76.8 pts. versus 53.9 pts.). No correlation was found between the date of the follow-up and the interval of time since the operation. CONCLUSION: After complex fractures of the humeral head satisfactory long-term results can be obtained by the cemented Neer II hemiprosthesis. Thus, implants of the newer generation can not yet whitness their superiority under consideration of functional aspects. Refixation and reintegration of both the tubercula after trauma still seems to be an unsolved problem and requires further development.

[Eccrine spiradenocarcinoma with unusual histiocytic giant cell components. Case report and review of the literature of a rare sweat gland tumor]. / Ekkrines Spiradenokarzinom mit ungewöhnlicher histiozytärer Riesenzellkomponente. Fallbericht und Literaturübersicht eines seltenen malignen Schweissdrüsentumors.

We report the case of a spiradenocarcinoma (malignant eccrine spiradenoma), a rare variant of a malignant sweat gland tumor, which occurred in the scalp of a 63-year-old woman. Some years before the current tumor occurred, a tumour of unknown histology had been excised from the same localization. The new tumor presented with rapid growth and exulceration. Malignant eccrine spiradenoma is characterized by the coincidence of a benign and a malignant portion within one specimen. We report case example 47 of this entity. The peculiarity of this case is the enormous heterogeneity with foci of atypical histiocytes like an atypical fibroxanthoma and an extensive foreign body reaction with cholesterol needles as in a xanthogranuloma. Static DNA cytophotometric analysis revealed different degrees of aneuploidy in the three tumor portions. The follow-up of 23 months is without recurrent tumor. A review of the literature is given.

Ultrasound and bronchoscopic controlled percutaneous tracheostomy on trauma ICU.

Tracheostomy is a common surgical procedure performed in long-term ventilated patients in intensive care. Since the role of percutaneous dilatational tracheostomy (PDT) on Intensive Care Unit (ICU) has become steadily more important in the last few years, a prospective study was started to evaluate the economic efficiency and to show the minimization of the complication rate of this procedure. In 72 patients we performed PDT as a bedside procedure. Initially the thyroid gland and the subcutaneous vessels were studied by ultrasound in every patient. The puncture of the trachea, the dilatational procedure and the insertion of the tracheal cannula were executed under bronchoscopic monitoring. Finally, a bronchoscopic control view followed via the new cannula to detect intratracheal complications. Mechanical ventilation was maintained during the procedure and controlled by continuous pulse oximetry. According to prior ultrasound findings the place to puncture the trachea was changed in 24% of the patients, in one case tracheostomy was performed as an open conventional procedure. The following complications could be observed: one case involving perforation of a cartilaginous ring, one case with venous bleeding of a small subcutaneous vein and two cases with punctures of the bronchoscope. There were no cases of miscannulation, penetration of the posterior tracheal wall or major bleeding requiring intervention or conversion. The followup study revealed that there was no sign of further complications in any patient. In addition, cost analysis demonstrated that there was a significant economical advantage of PDT in comparison with open standard tracheostomy. Standardized ultrasonographically and bronchoscopically controlled PDT turns out to be a safe, simple and cost effective bedside procedure on ICU. Because of ultrasound examination performed before the procedure, and bronchoscopic surveillance during the procedure, safety of this procedure can be enhanced, thus minimizing the rate of complications.

[A dynamic shoulder model for biomechanical measurements of shoulder specimen]. / Ein dynamisches Schultermodell für biomechanische Messungen an Schulterpräparaten.

The article discusses a dynamic shoulder model capable of simulating the forces generated by the rotator cuff and the deltoid muscle, and elevation movements of the glenohumeral joint using, a computer-aided servohydraulic unit. In 10 cadaver shoulder specimen, the effects of the loss of function of the supraspinatus muscle on maximum elevation was determined with an ultrasound system. Changes in the so-called impingement pressure below the coracoacromial arch were determined with the aid of capacitive pressure sensors. With the supraspinatus muscle inactive/ absent, the maximum elevation of the humerus showed a decrease of 6% (p < 0.05), which, however, was overcome by an increase in deltoid power of only one-third of the supraspinatus muscle power loss. For a simulated isolated supraspinatus defect, the subacromial pressure below the coracoacromial arch decreased by 8% (p > 0.05). These results confirm clinical investigations showing that isolated lesions affecting the supraspinatus tendon often fail to produce symptoms and thus require no surgical reconstruction.

Coracoacromial pressure recordings in a cadaveric model.

A dynamic shoulder model was used to determine the pressure distribution under the acromion, the coracoacromial ligament, and the coracoid process with simulated active glenohumeral joint motion in cadaveric specimens. Computerized regulation of servo-actuator forces initiated controlled cycles of glenohumeral joint motion. Pressures were recorded by using capacitive sensors. Peak pressures averaged 56.6 N/cm2 and were located at the anterolateral border of the acromion in most specimens. Marked pressures were present under the coracoid process. Lack of force of the supraspinatus muscle resulted in an 8% decrease of mean coracoacromial pressures, lack of force on the subscapularis and infraspinatus/teres minor muscles in a significant 61% increase, and lack of force on all rotator cuff muscles in a significant 35% increase. After anterior acromioplasty was performed, mean coracoacromial pressures decreased 5%.

A dynamic shoulder model: reliability testing and muscle force study.

This study introduces a dynamic shoulder model, where forces were applied to individual muscles in ten cadaveric specimens. The model provided reproducible glenohumeral joint motion and thereby allowed the investigation of active, glenohumeral joint mechanics. Forces were created by servo-actuated hydrodynamic cylinders and applied to the deltoid muscle and to the rotator cuff through wire cables. Computerized regulation initiated precise, time controlled cycles of glenohumeral joint motion. The position of the glenohumeral joint in all spatial orientations was measured and recorded using an ultrasonic sensor device. Reproducibility of glenohumeral joint motion was demonstrated on the basis of five cycles of glenohumeral joint elevation. Repeatability variance of position measurements for five cycles of elevation averaged 0.80 degrees for abduction, 0.75 degrees for anteflexion and 1.36 degrees for internal rotation. Arm weight and force distribution at the shoulder musculature were estimated according to the literature. In comparison to estimated physiologic conditions, a one third increase of arm weight led to a significant (p < 0.05) decrease of elevation of 20%, a one third decrease of arm weight to an average increase of elevation of 18% (p < 0.05). Exclusion of the supraspinatus muscle caused a significant (p < 0.05) 6% decrease of elevation of the glenohumeral joint. Without force applied to the subscapularis and infraspinatus/teres minor muscles, elevation decreased 16% (p < 0.05). A decrease of glenohumeral joint elevation of 25% resulted when force was applied to the deltoid muscle alone (p < 0.05).