[Thrombosis of the subclavian vein after conservative treatment of a clavicular fracture: A rare complication]

We report the case of a 16-year-old male patient who presented with a clavicular fracture that was conservatively treated with a redressment bandage. After a few days the patient developed deep vein thrombosis of the subclavian, axillary and brachial veins, which was successfully treated with nadroparin. Conservative treatment of clavicular fractures is a common procedure in modern traumatology. Continuous, close monitoring and knowledge of rare but severe complications are necessary to avoid further complications.

Fixation of acetabular fractures via the ilioinguinal versus pararectus approach

This study compared the quality of reduction and complication rate when using a standard ilioinguinal approach and the new pararectus approach when treating acetabular fractures surgically. All acetabular fractures that underwent fixation using either approach between February 2005 and September 2014 were retrospectively reviewed and the demographics of the patients, the surgical details and complications were recorded.

A total of 100 patients (69 men, 31 women; mean age 57 years, 18 to 93) who were consecutively treated were included for analysis. The quality of reduction was assessed using standardised measurement of the gaps and steps in the articular surface on pre- and post-operative CT-scans.

There were no significant differences in the demographics of the patients, the surgical details or the complications between the two approaches. A significantly better reduction of the gap, however, was achieved with the pararectus approach (axial: p = 0.025, coronal: p = 0.013, sagittal: p = 0.001).

These data suggest that the pararectus approach is at least equal to, or in the case of reduction of the articular gap, superior to the ilioinguinal approach.

This approach allows direct buttressing of the dome of the acetabulum and the quadrilateral plate, which is particularly favourable in geriatric fracture patterns.

Cite this article: Bone Joint J 2015;97-B:1271-8.

Functional and radiological outcome of periprosthetic fractures of the ankle

The incidence of periprosthetic fractures of the ankle is increasing. However, little is known about the outcome of treatment and their management remains controversial. The aim of this study was to assess the impact of periprosthetic fractures on the functional and radiological outcome of patients with a total ankle arthroplasty (TAA).

A total of 505 TAAs (488 patients) who underwent TAA were retrospectively evaluated for periprosthetic ankle fracture: these were then classified according to a recent classification which is orientated towards treatment. The outcome was evaluated clinically using the American Orthopedic Foot and Ankle Society (AOFAS) score and a visual analogue scale for pain, and radiologically.

A total of 21 patients with a periprosthetic fracture of the ankle were identified. There were 13 women and eight men. The mean age of the patients was 63 years (48 to 74). Thus, the incidence of fracture was 4.17%.

There were 11 intra-operative and ten post-operative fractures, of which eight were stress fractures and two were traumatic. The prosthesis was stable in all patients. Five stress fractures were treated conservatively and the remaining three were treated operatively.

A total of 17 patients (81%) were examined clinically and radiologically at a mean follow-up of 53.5 months (12 to 112). The mean AOFAS score at follow-up was 79.5 (21 to 100). The mean AOFAS score in those with an intra-operative fracture was 87.6 (80 to 100) and for those with a stress fracture, which were mainly because of varus malpositioning, was 67.3 (21 to 93). Periprosthetic fractures of the ankle do not necessarily adversely affect the clinical outcome, provided that a treatment algorithm is implemented with the help of a new classification system.

Cite this article: Bone Joint J 2015;97-B:950–6.

Skeletal metastatic disease of the femur: results by management with intramedullary nailing

PURPOSE OF THE STUDY This study aimed to analyse the outcome following intramedullary nailing for metastases of the femur in a large cohort with special regard to mechanical, implant associated complications and patient survival. Furthermore, we aimed to identify factors influencing the overall survival. MATERIAL AND METHODS All patients (n = 74) that underwent intramedullary nailing for metastatic disease of the femur between 2004 and 2008 and were retrospectively reviewed. Data were recorded from the patients' medical record and the outpatients' clinics files. Details about the tumour biology, the surgery performed as well as the postoperative care were documented. Survival data were extracted from patient records or obtained via communication with outpatient oncologists or the community registration office. RESULTS 74 (28 (37.8%) male, 46 (62.2%) female; p = 0.048) patients with a mean age of 64.4 ± 11.7 years were included. Breast (25, 33.8%), lung (18, 24.3%), bone marrow (7, 9.5%) and kidney (6, 8.1%) were the primary tumours in more than 75% of all patients. The mean overall survival was 17.5 (95% CI: 9.6 - 25.5) months. Patients with osseous metastases had a significant longer survival than patients with visceral and/or cerebral metastases (p = 0.025 and p = 0.032). CONCLUSION Intramedullary nailing represents a valuable fixation method for pathologic fractures or impending fractures of the femur in patients with an advanced stage of metastatic disease. It provides adequate stability to outlast the patient s remaining life-span. However, the balance must be found between therapeutic resignation and surgical overtreatment since operative treatment may be accompanied with serious complications. Key words: bone metastases, intramedullary nailing, metastatic disease, cement augmentation, osteolytic defect.

[CT-based classification aid for acetabular fractures: evaluation and clinical testing]

BACKGROUND

The basis for the classification of acetabular fractures depends on accurate radiological diagnostics. The use of conventional X-rays alone implicates a low intrapersonal reproducibility and interpersonal reliability. By applying computed tomography (CT) at an early stage in the emergency room, the typical diagonal X-rays of ala and obturator, on which the classification is based, are no longer recommended. The aim of this study was to develop a new reliable classification system based on standardized CT slices according to the system of Judet and Letournel without using diagonal X-rays.

MATERIALS AND METHODS

In this study 12 select cases with acetabular fractures were peer reviewed. In each case eight characteristic CT slices (five axial, two coronal and one sagittal) were selected as well as the conventional anteroposterior X-ray of the pelvis. All cases were peer reviewed by 14 members of the "AG Becken" (working group pelvis). The classification of the acetabular fractures was based on Judet and Letournel and the results were compared with the reference classification. The results were scaled according to differences to the original classification and the relevance to the approach as well as the medical qualification of the member.

RESULTS

A total of 167 out of 168 possible classifications were conducted, 90 cases (54 %) were in accordance with the reference classification. In 69 cases (41 %) the outcome was different, which would have had no influence on the choice of the surgical approach. A wrong classification was present eight times (5 %). According to the medical qualification status the senior physicians were right in 54%, the residents in 53 %. Within the group of senior physicians 7.5 % of the classifications were completely wrong and 93 % of the participating members would have preferred to have more CT slices.

CONCLUSION

The CT-based classification developed represents an adaption to the current standard of diagnostics of acetabular fractures and represents a step towards simplification of the classification. It is suitable to estimate the correct surgical approach and the behavior of the fracture. For an accurate classification and the association to one of the fracture types in the system of Judet and Letournel more slices and 3D reconstructions (MPR) are necessary.

[Solitary spinal metastases. Is aggressive surgical management justified?]

Advances in oncological and surgical therapies have led to a significant increase in life expectancy of cancer patients and also prolonged survival of patients with isolated or multiple metastases. Among the skeletal manifestations the spine is the most often affected site. Using novel imaging techniques with higher resolution and use of metabolic signatures, the screening of cancer patients has improved considerably. Consequently, the diagnosis of metastases is becoming increasingly more sensitive. Therefore, but also due to more effective polychemotherapy protocols, singular or solitary metastases are more frequently observed either in the early stages or as a result of a controlled malignant tumor entity (stable disease). The questions whether a solitary metastasis really exists (illusion or reality?) and its radical oncological and surgical treatment as a circumscribed singular tumor manifestation, is really relevant for the overall prognosis, remains controversial. However, it seems evident that a biologically favorable underlying tumor biology, radical treatment of the primary tumor and a long metastasis-free interval are valid predictors of a good oncological outcome. In the presence of a solitary metastasis under these circumstances (typical example: solitary metastasis of renal cell carcinoma many years after radical tumor nephrectomy) a radical surgical procedure (en bloc spondylectomy) can significantly improve the long-term prognosis of this patient group in combination with adjuvant chemotherapy and/or radiotherapy. However, a thorough evaluation of the overall survival prognosis, a detailed and complete staging followed by a treatment consensus in the interdisciplinary tumor board has to precede any therapeutical decisions.

Experimentelle Spondylodese der Schafshalswirbelsäule Teil 1: Der Effekt des Cage-Designs auf die intervertebrale Fusion

INTRODUCTION

There has been a rapid increase in the use of interbody fusion cages as an adjunct to spondylodesis, although experimental data are lacking. A sheep cervical spine interbody fusion model was used to determine the effect of different cage design parameters (endplate-implant contact area, maximum contiguous pore) on interbody fusion.

MATERIAL AND METHOD

IN VITRO EVALUATION: 24 sheep cadaver specimens (C2-C5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Four different groups were examined: (1) control group (intact) ( n=24), (2) autologous tricortical iliac crest bone graft ( n=8), (3) Harms cage ( n=8), and (4) SynCage-C ( n=8). IN VIVO EVALUATION: 24 sheep underwent C3/4 discectomy and fusion: group 1: autologous tricortical iliac crest bone graft ( n=8), group 2: Harms cage filled with autologous cancellous iliac crest bone grafts ( n=8), and group 3: SynCage-C filled with autologous cancellous iliac crest bone grafts ( n=8). Radiographic scans were performed pre- and postoperatively and after 1, 2, 4, 8, and 12 weeks, respectively. At the same time points, disc space height (DSH), height index (HI), intervertebral angle (IVA), and endplate angle (EA) were measured. After 12 weeks the animals were killed and fusion sites were evaluated using biomechanical testing in flexion, extension, axial rotation, and lateral bending. Additionally, histomorphological and histomorphometrical analyses were performed.

RESULTS

Over a 12-week period the cage groups showed significantly higher values for DSH, HI, IVA, and EA compared to the bone graft. In vivo stiffness was significantly higher for the tricortical iliac crest bone graft and Harms cage than in vitro stiffness. However, there was no difference between in vitro and in vivo stiffness of the SynCage-C. Histomorphometrical evaluation showed a more progressed bone matrix formation in the Harms cage group than in both other groups.

CONCLUSION

The parameter endplate-implant contact area was not able to determine subsidence of cages. In contrast, the maximum contiguous pore of a cage significantly correlates with interbody bone matrix formation inside the cage. Additionally, there was no correlation between in vitro and in vivo stiffness of interbody fusion cages. Therefore, biomechanical in vitro studies are not able to determine in vivo outcome of fusion cages. Animal experimental evaluations of interbody fusion cages are essential prior to clinical use.

Requirement for a structured algorithm in cardiac arrest following major trauma: epidemiology, management errors, and preventability of traumatic deaths in Berlin

BACKGROUND

Despite continuous innovation in trauma care, fatal trauma remains a significant medical and socioeconomic problem. Traumatic cardiac arrest (tCA) is still considered a hopeless situation, whereas management errors and preventability of death are neglected. We analyzed clinical and autopsy data from tCA patients in an emergency-physician-based rescue system in order to reveal epidemiologic data and current problems in the successful treatment of tCA.

MATERIAL AND METHODS

Epidemiological and autopsy data of all unsuccessful tCPR cases in a one-year-period in Berlin, Germany (n=101, Group I) and clinical data of all cases of tCPR in a level 1 trauma centre in an 6-year period (n=52, Group II) were evaluated. Preventability of traumatic deaths in autopsy cases (n=22) and trauma-management failures were prospectively assessed.

RESULTS

In 2010, 23% of all traumatic deaths in Berlin received tCPR. Death after tCPR occurred predominantly prehospital (PH;74%) and only 26% of these patients were hospitalized. Of 52 patients (Group II), 46% required tCPR already PH and 81% in the emergency department (ED). In 79% ROSC was established PH and 53% in the ED. The survival rate after tCPR was 29% with 27% good neurological outcome. Management errors occurred in 73% PH; 4 cases were judged as potentially or definitive preventable death.

CONCLUSION

Trauma CPR is beyond routine with the need for a tCPR-algorithm, including chest/pericardial decompression, external pelvic stabilization and external bleeding control. The prehospital trauma management has the highest potential to improve tCPR and survival. Therefore, we suggested a pilot prehospital tCPR-algorithm.

[Multisegmental en bloc spondylectomy. Indications, staging and surgical technique]

OBJECTIVE

Description of the surgical technique including approaches and spinal reconstruction principles for patients scheduled for multilevel en bloc excision of vertebral tumors (multisegmental total en bloc spondylectomy) with the aim to attain tumor-free margins and minimize the risk of local and systemic tumor recurrence. Restoration of biomechanically sufficient spinal stability. Functional preservation and/or regaining of adequate neurological function.

INDICATIONS

Primary malignant and benign, aggressive spinal tumors. Solitary metastatic tumors of biologically and prognostically favorable primary tumor (good prognostic scores). Extracompartmental, multisegmental vertebral tumor manifestations according to Tomita type 6.

CONTRAINDICATIONS

Diffuse spinal/vertebral tumor spread according to Tomita type 7 (disseminated spinal metastatic disease). Detection of distant metastases in the staging investigation. Biologically unfavorable tumor entities or primary systemic malignant tumors/diffuse disseminated malignoma (Tomita score < 4-5 points, Tokuhashi score < 12 points).

SURGICAL TECHNIQUE

Depending on tumor growth, sequential performance of the anterior and posterior approach for local tumor release and preparation/replacement of encased large vessels. Posterior approach via dorsomedial incision and exposure of the posterior vertebral elements. Costotransversectomy, resection of the facets, resection of paravertebral rib segments. Laminectomy in the tumor-free lamina segment, resection of the ligamentum flavum and paradural ligation of affected nerve roots, bilateral ligation of the segmental arteries. Digital extrapleural palpation and dissection to the anterior vertebral body parts. Insertion of S-shaped spatulas ventral to the anterior aspect of the spine, and dissection of the disc spaces and the posterior longitudinal ligament. Instrumentation of pedicle screws and unilateral rod fixation, mobilization and careful, manual turning out/rotation of the affected vertebral segments around the longitudinal axis of the spinal cord. Interpositioning of a carbon-composite cage from posterior filled with autologous bone. Completion of the posterior stabilization, soft tissue closure, Goretex patch fixation if required in cases of chest wall resections.

POSTOPERATIVE MANAGEMENT

Intensive care monitoring with balanced volume replacement/transfusion. Postoperative adjuvant radiotherapy or chemotherapy, depending on the protocol and resection margins.

[Coincidence of traumatic tracheal rupture accompanied by ARDS. Illustrated by the example of a 17-year-old patient with multiple injuries]

Treatment and diagnosis of a traumatic tracheal rupture is a challenge. Due to the rarity of such injuries and the subtle and delayed clinical presentation it is difficult to diagnose. We present for the first time the successful management of a 17-year-old multiply injured patient with coincidental tracheal rupture and ARDS (acute respiratory distress syndrome) after a fall. Besides the case report and pathogenesis the essential diagnostic and therapeutic measures are mentioned and discussed. The circumstances surrounding the accident have to be balanced with the severity of the trauma to also exclude rare injuries with certainty. Finally level 1 trauma centers specialized in ARDS provide the best clinical setting for successful treatment of these life-threatening injuries.

Surgical management of recurrent thoracolumbar spinal sarcoma with 4-level total en bloc spondylectomy: description of technique and report of two cases

INTRODUCTION

The descriptions of total spondylectomy and further development of the technique for the treatment of vertebral sarcomas offered for the first time the opportunity to achieve oncologically sufficient resection margins, thereby improving local tumor control and overall survival. Today, single level en bloc spondylectomies are routinely performed and discussed in the literature while only few data are available for multi-level resections. However, due to the topographic vicinity of the spinal cord and large vessels, the multisegmental resections are technically demanding, represent major surgery and only few case reports are available. Surgical options are even more limited in cases of revision surgery and local recurrences when en bloc spondylectomy was considered to be not feasible due to high risk of vital complications in expanding resection margins. Deranged anatomy, implants in situ and extensive intra-/paraspinal scar tissue formation resulting from previously performed approaches and/or radiation are considered the principal complicating factors that usually hold back spine surgeons to perform revision for resection leaving the patient to palliative treatment.

METHODS

We present two patient cases with previously performed piecemeal vertebrectomy in the thoracic spine due to a solitary high-grade spinal sarcoma. After extensive re-staging, both patients underwent a multi (4)-level en bloc spondylectomy in our department (one patient with combined en bloc lung resection). Except a local wound disturbance, there was no severe intra- or postoperative complication.

RESULTS

After multilevel en bloc spondylectomy both patients showed a good functional outcome without neurological deficits, except those resulting from oncologically scheduled resection of thoracic nerve roots. After a median follow-up of 13 months, there was no local recurrence or distant metastasis. The reconstruction using a posterior screw rod system that is interconnected to an anterior vertebral body replacement with a carbon composite cage showed no implant failure or loosening. In summary, the approach of a multilevel en bloc surgery for revision and oncologically sufficient resection in cases of spinal sarcoma recurrences seems possible. However, interdisciplinary decision making in a tumor board, realistic evaluation of surgical resectability to attain tumor free margins, advanced experiences in spinal reconstructions and involvement of vascular, visceral and thoracic surgical expertise are essential preconditions for acceptable oncological and functional outcome.

[Locking plates for osteosyntheses of corrective osteotomies in paediatric orthopaedic and neuroorthopaedic patients]

BACKGROUND

Modern locking plates are widely used for the treatment of adult orthopaedic and trauma patients. Sporadic descriptions of their advantages now exist for paediatric trauma patients. Publications concerning their implantation in paediatric orthopaedic and neuroorthopaedic patients are still scarce even though it is well known that the compliance of children and adolescents is limited and that rapid mobilisation is essential for patients with disorders of neurological origin or bone metabolism to avoid developmental setbacks and perioperative fractures.

PATIENTS AND METHODS

The principle of the locking plate system also described as internal fixateur is based on the thread bolting of the screwheads within the plate. This results in high initial stability and thus high initial loading capacity. Furthermore, it is possible to preserve soft tissue and periosteum which leads to less impaired biological bone healing. Between February 2008 and March 2010 locking plates were used for osteosynthesis in our department in 16 paediatric patients with 20 corrective osteotomies. All patients suffered from either neurological disorders or diseases with alteration of the bone metabolism. The outcome was analysed concerning safety, complications, practicability, mobilisation, consolidation of the osteotomy, loss of correction, as well as complications with the removal of the implants.

RESULTS

Seven of the treated patients suffered from neurological disorders such as cerebral palsy or spina bifida, 9 patients had diseases with local or systemic alteration of their bone metabolism such as vitamin D deficiency and phosphate diabetes. The average age of the patients at the time of surgery was 11.18 (5-18) years. Implant-associated complications were not seen in this patient group, especially no implant failures. Mobilisation was achieved without cast treatment with at least partial weight-bearing within the first postoperative week in most cases. Loss of correction or problems with implant removal did not occur. 18 of the 20 osteotomy sites were completely healed at the 12 week follow-up.

CONCLUSION

Locking plates are a safe and effective treatment device not only for adult trauma patients but also for the treatment of children and adolescents. When stabilisation of corrective osteotomies is performed with locking plates especially young patients benefit from this technique since mobilisation can be started earlier as compared to the use of non-angle stable plates or wires and cast immobilisation becomes unneccessary. The surgeon needs to know the range of products to pick the best implant regarding the growing skeleton's special anatomy. When choosing implants for patients with reduced bone density or impaired motor abilities as in cerebral palsy, spina bifida, and other systemic disorders, locking plates have to be taken into account to facilitate mobilisation and to avoid setbacks in motor development as well as pressure ulcers from casts. Clinical studies have to evaluate if early mobilisation combined with shorter inpatient treatment and less time and cost consuming postoperative physiotherapy or rehabilitation justify the use of the more expensive locking plates for the treatment of otherwise healthy patients.

[Clinical research in partnership: musculoskeletal surgery]

As a result of the demographic development of industrial nations the number of musculoskeletal diseases and injuries rises continuously. This challenges health care as well as clinical research and demands additional endeavours. The United Nations have recognised this issue at an early stage. With their in 2000 declared Bone and Joint Decade they have significantly contributed to a sustainable support of research activities. The German government has also perceived the need and, with their roadmap programme, encourages research of musculoskeletal disease.Today, surgical and orthopaedic clinics increasingly support the exchange between research and clinic and run their own research departments. The Berlin Center for Musculoskeletal Surgery (CMSC) and its research institute Julius Wolff Institut show the potential for surgical research. It shows that based on a clinical understanding of the problem, basic research needs to be complemented in a network with partners from other disciplines. However, interdisciplinary cooperation demands new and individual ways of communication and education. The example in Berlin also illustrates that the research on prevention not only completes the network but more over opens unexpected possibilities in understanding basic research and translation.

[Development of trauma surgery in the next 20 years]

During the last century trauma surgery became established as an independent and academically accepted surgical specialty and significant progress was achieved. A high international reputation was also gained. Nowadays health care in Germany is under increased economical pressure mostly caused by a loss of resources as a sign of decreased public appreciation of excellent trauma care. Thus it becomes more and more necessary to find new structures for delivery of trauma care as well as for development of staff, especially in times of feminization in medicine. It is beyond any doubt that the demand for musculoskeletal surgery will rise during the next 20 years especially for the elder generation but it is uncertain how excellent trauma care should be delivered without massive spending and financing of health care including research and innovative forms of trauma treatment.

Simvastatin locally applied from a biodegradable coating of osteosynthetic implants improves fracture healing comparable to BMP-2 application

Many clinical and experimental investigations address the influence of statins on bone formation and fracture healing. Simvastatin was shown to increase the expression of Bone morphogenetic protein (BMP-2), which is one of the most potent growth factors targeting bone formation. In this study, the effect of simvastatin locally applied from a bioactive polymer coating of implants on fracture healing was investigated. A closed fracture of the right tibia of 5-month-old Sprague-Dawley rats was performed. Intramedullary stabilization was achieved with uncoated vs. polymer-only coated vs. polymer plus drug coated titanium Kirschner wires. Test substances (either simvastatin low- or high dosed or BMP-2) were incorporated into a biodegradable layer of poly(d,l-lactide). Tibiae were harvested after 28 or 42 days, respectively and underwent biomechanical testing (torsional stiffness and maximum load) and histomorphometric analysis. Radiographic results demonstrated progressed callus consolidation in the BMP-2- and simvastatin-treated groups compared to the uncoated group at both timepoints. The simvastatin-high-dosed group revealed an increased torsional stiffness and significantly elevated maximum load (d 28) compared to control group as well as a significant increase in both parameters at d 42. BMP-2-treated animals showed significantly elevated maximum load and stiffness at the early timepoint and elevated torsional stiffness after d 42. The histomorphometric analysis revealed a significantly decreased cartilage area for BMP-2 treated animals at d 28. Even though an increase of mineralized areas among periosteal callus was found at d 42 for simvastatin-high as well as BMP-2 treated animals, no significant difference could be detected at both timepoints compared to the uncoated group. However, simvastatin-high treated animals revealed significantly reduced cartilage areas within the periosteal callus at d 42. The present study revealed a dose-dependent effect and improved fracture healing under local application of simvastatin. Biomechanical, radiographic and histomorphometric properties showed comparable results to BMP-2- treated animals in this study.

[Best matching. Experimental comparison of different matching procedures for use in computer navigation]

INTRODUCTION

Computer navigation systems are increasingly becoming an integral part of the surgical routine in orthopedic and trauma surgery due to improvements in intraoperative visualization procedures. The matching, i.e. data alignment between virtual and therapeutic objects, is however still a persisting problem. In recent years various matching procedures have been developed to attempt to solve the problem. In this study we compared three matching procedures using the VectorVision navigation system.

MATERIAL AND METHODS

For each matching procedure three artificial models of the lumbar spine (TH10-Os sacrum, Synbone, Malans CH) were used with the VectorVision system as navigation system (BrainLAB, Feldkirchen/Siemens, Erlangen, Germany). The experimental setup was standardized for the different navigational methods. First a CT scan of the models was acquired and based on this data set a master planning for all pedicle drillings was performed. A total of 48 drillings with pairpoint, region or CT fluoromatching were accomplished and evaluated. The time periods needed for the matching procedures were documented and compared with each other. The precision of the drillings was evaluated within the postinterventional CT. Altogether 144 drillings for pedicle screws were performed on artificial models based on an identical planning for all test series.

RESULTS

Within the experimental study of 144 drillings, only 2 perforations (1.3%) of the lateral cortical wall were detected. The time needed for the matching procedure was the shortest for region matching, followed by the pairpoint matching. The CT fluoromatching was the longest procedure. Variations in the distance of the individual drilling to the cortical wall were comparably large in all test series (on average 1.3 mm). Significant differences concerning the precision of the different matching procedures could only be shown for pairpoint matching.

CONCLUSION

In our study pairpoint matching was the only procedure without misplacement and on average had the largest safety margin for drillings. Thus this method was the most precise procedure. The region matching procedure offers the advantage of the fastest matching with comparable precision.

[Fast track in casualty surgery]

The concept of "fast track" has not yet been established in orthopaedic trauma surgery. Principles such as those used in the "fast track" procedure for abdominal surgery have been employed in orthopaedic surgery for a long time. The best results can be achieved by early operative treatment, stable osteosynthesis and, if the soft tissues allow, an early initiation of mobilization under optimal pain management. Based on new techniques in osteosynthesis, in particular locked-screw techniques, "fast track" is also applicable for fragility fractures (osteoporosis), complex shattered bone and bone defect situations.

Humeral head necrosis rate at mid-term follow-up after open reduction and angular stable plate fixation for proximal humeral fractures

INTRODUCTION

Short-term follow-up of angular stable fixation for proximal humeral fractures has been well documented in the literature. Longer follow-up series are difficult to find. However, especially regarding the risk of avascular humeral head necrosis longer follow-up series are high of clinical relevance.

METHODS

Forty-eight patients with a mean age of 66 years and treated with open reduction and angular stable internal fixation for proximal humeral fractures were followed up for a mean of 45 months. The clinical and radiographic follow-up (Constant Score (CS), age and gender related Constant Score (agCS), Constant Score in comparison to the contralateral side (%CS) and shoulder anterior-posterior and lateral view and axial view X-rays) was performed postoperatively.

RESULTS

Clinical results after 45 months showed a mean CS of 66.2+/-15.4 points with a mean agCS of 90.0+/-23.1%. Evaluation of the %CS showed 77.7+/-17.8%. %CS results showed no significant differences after 45 months in comparison to those obtained after 12 months. However, incidence of avascular necrosis of the humeral head doubled over the follow-up period from 4 cases at 12 months follow-up to 9 cases at final follow-up.

CONCLUSION

Results of open reduction and internal fixation with angular stable implants for proximal humeral fractures are reliable, however long-term complications such as avascular necrosis of the humeral head need to be evaluated further on since its incidence increases over the time.

Biomechanical comparison of two different concepts for stand alone anterior lumbar interbody fusion

Segmental instability in degenerative disc disease is often treated with anterior lumbar interbody fusion (ALIF). Current techniques require an additional posterior approach to achieve sufficient stability. The test device is an implant which consists of a PEEK-body and an integrated anterior titanium plate hosting four diverging locking screws. The test device avoids posterior fixation by enhancing stability via the locking screws. The test device was compared to an already established stand alone interbody implant in a human cadaveric three-dimensional stiffness test. In the biomechanical test, the L4/5 motion segment of 16 human cadaveric lumbar spines were isolated and divided into two test groups. Tests were performed in flexion, extension, right and left lateral bending, right and left axial rotation. Each specimen was tested in native state first, then a discectomy was performed and either of the test implants was applied. Finite element analysis (FE) was also performed to investigate load and stress distribution within the implant in several loading conditions. The FE models simulated two load cases. These were flexion and extension with a moment of 5 Nm. The biomechanical testing revealed a greater stiffness in lateral bending for the SynFix-LR compared to the established implant. Both implants showed a significantly higher stiffness in all loading directions compared to the native segment. In flexion loading, the PEEK component takes on most of the load, whereas the majority of the extension load is put on the screws and the screw-plate junction. Clinical investigation of the test device seems reasonable based on the good results reported here.

[Postoperative manifestation of acute compartment syndrome by previously unknown heterozygote sickle cell anemia. A clinical case report]

Patients suffering from sickle cell disease show an increased ischemic intolerance due to continuous pro-inflammatory activation and dysfunction of the endothelium by recurrent vaso-occlusive episodes. The presented case shows the manifestation of a postoperative compartment syndrome of the lower leg following the intraoperative use of blood arrest in a patient with previously unknown sickle cell disease. Preexisting vulnerability for tissue hypoxia in patients at risk should be a major concern for intraoperative use of blood arrest during surgery of the extremities.

Outcome after open reduction and angular stable internal fixation for supra-intercondylar fractures of the distal humerus: preliminary results with the LCP distal humerus system

INTRODUCTION

Fractures of the distal humerus are complex injuries that can be effectively treated with open reduction and internal fixation (ORIF). The new LCP distal humerus system allows angular stable fixation of these complex fractures with anatomically preshaped plates. The aim of the study was to evaluate operative reposition, fracture healing, and pain, function and patient satisfaction after open reduction with an angular stable fixation.

METHODS

Fourteen patients with a mean age of 55.2 years (21-83) were treated with open reduction and angular stable internal fixation. Two patients were lost to follow up (1 died, one refused to be reevaluated). AO classification showed 12 C-fractures (1 x C 1.1; 1 x C 1.3; 4 x C 2.2; 4 x C 3.2; 2 x C 3.3) and 2 B-fracture (B 2.3 and B 3.3). 5 fractures were open fractures (4 x II degrees , 1 x I degrees ). The clinical and radiographic follow up (Mayo elbow performance score (MEPS), Dash Score, elbow anterior-posterior and lateral view X-rays, and flexion and extension force as % of contralateral side at 90 degrees flexion) were performed postoperatively. Mean follow up was 10 months.

RESULTS

Radiographically, complete union was achieved in all patients. There were no cases of primary malposition or secondary dislocation. Complications were: (1) delayed union after olecranon osteotomy, (2) transient ulnar nerve irritation. Clinical MEPS results were good to excellent with a mean of 91 +/- 11.7 points. The mean DASH Score was 18.5 +/- 11.5 points. Mean flexion was 121 +/- 20.9, mean extension deficit was 17.9 degrees +/- 10.3. Mean flexion force was 75.3% +/- 26.7 and mean extension force was 70.7 % +/- 24.9.

CONCLUSION

Treatment of supra-intercondylar fractures of the distal humerus is challenging. Anatomically preshaped angular stable implants facilitate operative reduction and stabilization of the fracture and may allow early postoperative rehabilitation. Clinical and radiological results are promising, with good range of motion and flexion and extension force.

[Ventral stabilization of the lumbar spine of a 2-year-old boy with an expandable cage : 7-year course]

This case report describes the first implantation of an expandable cage into the lumbar spine of a 2-year-old boy. Due to incomplete remission of a teratoma, it was necessary to replace the second lumbar vertebral body with an expandable cage implantation and subsequent dorsoventral stabilization. During the follow-up period with annual x-ray examinations, a loss of correction without increased pain or neurological deficits could be shown in the now 9-year-old boy.

[Developments in polytrauma management. Priority-based strategy]

The acute and early phase of polytrauma management is decisive for determining and implementing priority-based operative strategy. The patient's general condition and pattern of injury have to be considered. The highest priorities in the acute phase of operative treatment are control of mass bleeding and the release of body cavities (life-saving surgery). In the primary phase of surgical management (day 1 surgery), selected injuries are treated in the order of their urgency. Conceptual damage control surgery is distinguished from early total care. Damage control surgery should be performed only in patients meeting certain instability and risk criteria to avoid additionally burdening their condition.

[Local vertebral body destruction after migration of a nucleus replacement]

We present the case report of a 32-year-old female suffering from severe low back pain because of local vertebral body destruction at L3/4 after migration of PDN-SOLO nucleus replacement. Removal of the dislocated implant via a posterior transforaminal approach was not possible. After posterior stabilisation the implant could be salvaged from the anterior direction, but stabilisation with a vertebral body replacement was necessary.

Quantification of various growth factors in different demineralized bone matrix preparations

Besides autografts, allografts, and synthetic materials, demineralized bone matrix (DBM) is used for bone defect filling and treatment of non-unions. Different DBM formulations are introduced in clinic since years. However, little is known about the presents and quantities of growth factors in DBM. Aim of the present study was the quantification of eight growth factors important for bone healing in three different "off the shelf" DBM formulations, which are already in human use: DBX putty, Grafton DBM putty, and AlloMatrix putty. All three DBM formulations are produced from human donor tissue but they differ in the substitutes added. From each of the three products 10 different lots were analyzed. Protein was extracted from the samples with Guanidine HCL/EDTA method and human ELISA kits were used for growth factor quantification. Differences between the three different products were seen in total protein contend and the absolute growth factor values but also a large variability between the different lots was found. The order of the growth factors, however, is almost comparable between the materials. In the three investigated materials FGF basic and BMP-4 were not detectable in any analyzed sample. BMP-2 revealed the highest concentration extractable from the samples with approximately 3.6 microg/g tissue without a significant difference between the three DBM formulations. In DBX putty significantly more TGF-beta1 and FGFa were measurable compared to the two other DBMs. IGF-I revealed the significantly highest value in the AlloMatrix and PDGF in Grafton. No differences were accessed for VEGF. Due to the differences in the growth factor concentration between the individual samples, independently from the product formulation, further analyzes are required to optimize the clinical outcome of the used demineralized bone matrix.

Chirurgisches Management von Wirbelsäulenmetastasen

The spine is the most frequent site of skeletal metastases. Among all spinal malignancies metastatic disease is most frequent and indicative of disseminating tumor disease. Depending on primary tumor entity, estimated survival time, general health status of the patient, presence of spinal instability and neurological deficits an oncological useful and patient-specific therapeutic intervention should be performed. New anterior approaches, resections and reconstruction techniques are making surgery a preferred method over radiation therapy. For differential indication of the multiple surgical treatment modalities prognostic scores are available to assist individual decision making. Indications for surgery include survival prognosis of minimum 3 months, intractable pain, progress of myelon compression and/or neurological deficits under radiochemotherapy, spinal instability and necessity for histological diagnosis. Resulting quality of life depends on efficient decompression of the spinal cord and restoration of spinal stability. To achieve these ultimate goals there are different anterior and posterior approaches, instrumentations and vertebral body replacement implants available. Preoperative embolization should be performed in hypervascular tumors, e.g., renal cell cancer. Vertebro-/Kyphoplasty as a percutaneous intervention should be considered for painful multisegmental disease and symptomatic osteolysis without epidural tumor compression to reach analgesia and stability. A multidisciplinary approach in patient selection, decision making and management is an essential precondition for complication avoidance and acceptable quality of life.

Quantitative assessment of growth factors in reaming aspirate, iliac crest, and platelet preparation

Large bony defects and non-unions are still a complication in trauma and orthopedic surgery. Treatment strategies include the use of autogenous materials (iliac crest), allogenic bone, bone substitutes, and currently stimulation with growth factors such as BMP-2, BMP-7 or the growth factors containing platelet-rich plasma (PRP). Another source of bone graft material might be the cuttings produced during intramedullary reaming. The aim of this study was to compare the quantity of various growth factors found within iliac crest, bony reaming debris, reaming irrigation fluid, and platelet-rich plasma. Iliac crest and reaming debris and irrigation samples were harvested during surgery. PRP was prepared from blood. The growth factors in the bony materials (iliac crest or reaming debris) and of the liquid materials (platelet-poor plasma (PPP), platelet-rich plasma (PRP) or reaming irrigation) were compared. Elevated levels of FGFa, PDGF, IGF-I, TGF-beta1 and BMP-2 were measured in the reaming debris as compared to iliac crest curettings. However, VEGF and FGFb were significantly lower in the reaming debris than from iliac crest samples. In comparing PRP and PPP all detectable growth factors, except IGF-I, were enhanced in the platelet-rich plasma. In the reaming irrigation FGFa (no measurable value in the PRP) and FGFb were higher, but VEGF, PDGF, IGF-I, TGF-beta1 and BMP-2 were lower compared to PRP. BMP-4 was not measurable in any sample. The bony reaming debris is a rich source of growth factors with a content comparable to that from iliac crest. The irrigation fluid from the reaming also contains growth factors.

[Integrated navigation. Preclinical evaluation and initial clinical experience]

BACKGROUND

Computer navigation systems have increasingly become part of the surgical routine due to the improvements of intraoperative visualization procedures. Because of limited space in the operating room and insufficient workflow, the project of integrated navigation had been started.

METHODS

As the first step, the navigation system VectorVision2 and the second-generation fluoroscopic C-arm system Orbic 3D were integrated into one common trolley. In an experimental study the integrated navigation system was used to drill 160 pedicle screws. Afterwards the system was clinically evaluated in 11 surgical procedures.

RESULTS

During the whole experimental study the system could be used for all 160 drilling procedures without any technical faults, causing a failure rate of 4.2%. For clinical evaluation the integrated navigation system was used in seven patients with navigated dorsal spine instrumentation, in three cases sacroiliac screws were placed, and in one case supra-acetabular screw osteosynthesis was performed for an acetabular fracture. In all cases the positioning of the screws was correct and no system failure occurred.

CONCLUSIONS

The combination of the navigation system and the C-arm system in one common trolley is a major improvement of the surgical workflow. In the experimental study and the clinical trials the system worked extremely reliably and with high precision.

Quantification of growth factors in allogenic bone grafts extracted with three different methods

BACKGROUND

Bony allografts are used for defect filling. A reliable sterilization method is the peracetic acid-ethanol sterilization procedure (PES). Several studies showed the antimicrobiological efficacy of this method. Aim of this study was the quantification of growth factors necessary for bone formation in PES sterilized allografts (n = 9).

METHODS

To extract the growth factors from the tissue three different methods were used: (a) use of collagenase 1 for extraction, (b) incubation of the material in a proteinase inhibitor cocktail (Complete), and (c) extraction with guanidine HCl. The supernatants from the different methods were analyzed for the total protein concentration and different growth factors.

RESULTS

The extraction with guanidine HCl resulted in the highest amount of protein measurable in the supernatants of the samples. For comparison of the individual growth factor values the results were normalized to the protein content. The highest growth factor amount/protein was detectable for BMP-2 using the GndHCL method followed by FGFa, IGF-I, TGF-beta1, VEGF, and PDGF. Comparing the three extraction methods, significant differences were measured for the individual growth factor content.

CONCLUSION

PES sterilized bony allografts contain several growth factors. Depending on the extraction method, the quantity of the analyzed growth factors varies.

Percutaneous balloon kyphoplasty in the treatment of pathological vertebral body fracture and deformity in multiple myeloma: a one-year follow-up

PURPOSE

To evaluate the clinical and radiographic outcomes of balloon kyphoplasty in patients with fractures of the thoracic and lumbar spine caused by multiple myeloma.

MATERIAL AND METHODS

Vertebral fractures due to multiple myeloma were treated by balloon kyphoplasty (20 patients, 48 vertebral bodies). Symptomatic levels were identified by clinical presentation, magnetic resonance imaging (MRI), radiographs, and computed tomography (CT). During the following year, visual analog scale (VAS) and Oswestry disability score were documented. Radiographs were taken pre- and postoperatively at 3, 6, and 12 months. Vertebral height and kyphotic deformity were measured to assess restoration of the sagittal alignment.

RESULTS

The median pain scores (VAS) decreased significantly from pre- to posttreatment, as did the Oswestry disability score (p < 0.05). Clinically asymptomatic cement leakage occurred at 5 fracture levels (10.4%). During 1-year follow-up, this surgical technique demonstrated restoration and stabilization of the height of the vertebral body.

CONCLUSION

Balloon kyphoplasty is an effective minimally invasive procedure for stabilizing pathological vertebral fractures caused by multiple myeloma and leading to a statistically significant reduction of pain status. Balloon kyphoplasty stabilizes the vertebral body height, but is only partially able to prevent further kyphotic deformities.

Stabilisation of periprosthetic fractures with angular stable internal fixation: a report of 13 cases

INTRODUCTION

Periprosthetic fractures of the femur present a challenging surgical problem. The aim of this study was to retrospectively evaluate the outcome of periprosthetic fractures stabilised with an angular stable, less invasive stabilisation system (LISS).

PATIENTS AND METHODS

Thirteen patients (ten total hip-, two total knee-, one total hip- and knee-arthroplasty) with periprosthetic fractures were treated with the LISS internal fixator (in ten cases minimal invasive). Six patients had previous operations due to periprosthetic fractures. The average follow-up period was 20 months, follow-up rate 85%.

RESULTS

All fractures showed radiographic fracture healing without implant loosening. Except one patient, all patients had returned to their pre-operative activity level. No early post-operative complications were seen. There was one implant failure after 4 months and two cases of malunion.

CONCLUSION

The cases showed the internal fixator to be effective for the stabilisation of periprosthetic fractures, even in cases of poor bone quality with good functional outcomes. The internal fixator, with the option of minimal invasive application, is the preferred method of osteosynthesis in periprosthetic fractures.

[Traumatic aneurysm of the superior mesenteric artery associated with a burst- fracture of the second lumbar spine -- unforeseen sequelae of a fall from a ladder!]

Traumatic aneurysms of the superior mesenteric artery, although uncommon, are nevertheless life-threatening because of their high risk of rupture. In this case report the aneurysm was accompanied by a burst fracture of the second lumbar spine nearly at the same height. In a prolonged case the diagnosis of the injury was delayed. The clinical manifestation of repeated episodes of abdominal pain did not recur after resection of the aneurysm and interposition of a venous autograft.

Klinische Erfahrungen mit dem Siremobil Iso-C3D-Bildwandler in der Beckenchirurgie

In pelvic and acetabular surgery intraoperative control of reduction and implant position is sometimes hard to achieve with conventional C-arm technology. The Siemens C-arm Iso-C(3D) imaging system enables axial cuts and two- or three-dimensional reconstructions to be generated. Following the good experience in surgery of the spine and extremities, its clinical applicability in pelvic surgery was evaluated in 30 patients in a prospective clinical trial. In all 20 patients with acetabular fractures reduction quality and implant position could be well assessed. In one postoperative examination an intraarticular screw placement was evident, which intraoperatively was not as clear and was revised. In one procedure an intraarticular fragment was visualized, and was extracted in the same procedure. In one procedure the use of the Iso-C(3D) system enabled the approach to be limited. In all ten pelvic ring injuries the osseous structures in the posterior pelvic ring could be visualized with an adequate image quality. Reduction quality and implant position could be assessed in all open and closed procedures. On two occasions the SI screws were navigated based upon the Iso-C(3D) dataset. Overall the use of the Iso-C(3D) system was successful in all cases. Image quality, which is clearly inferior to that of CT, was sufficient for the assessment of reduction quality and implant position. One revision was indicated, and one avoided. However, in spite of its advantages in pelvic surgery, handling, sterile covering and data transfer need to be improved. For bilateral pelvic injuries the image size is too small.

Angle stable locking reduces interfragmentary movements and promotes healing after unreamed nailing. Study of a displaced osteotomy model in sheep tibiae

BACKGROUND

Large interfragmentary movements may delay bone-healing. The hypothesis of the present study was that a reduction of interfragmentary movements, especially of torsional rotation and bending angles, would support the healing process and lead to improved healing following unreamed tibial nailing. The objective of this study was to investigate healing of an unstable tibial osteotomy site following stabilization with unreamed nailing with a modified tibial device that had angle stable holes for the locking bolts. We compared those findings with healing after stabilization of such sites with standard unreamed tibial nailing. The duration of the study period was nine weeks.

METHODS

The site of a standardized displaced osteotomy (3-mm gap) in twelve ovine tibiae was stabilized with unreamed tibial nailing: six animals were treated with a modified nail that had angle stable holes for the locking bolts, and six were treated with standard unreamed tibial nailing. In vivo gait analysis with optical measurements of interfragmentary movements and simultaneous measurements of ground reaction parameters were performed three days after the operation and once weekly afterward. After the animals were killed at nine weeks, the treated and contralateral tibiae were explanted, the implants were removed, and radiographs were made and evaluated for bridged cortices. Each pair of tibiae was also mechanically tested until torsional failure, after which the whole callus region was subjected to histological and histomorphometric analysis.

RESULTS

Throughout the examination period, the interfragmentary movements in all directions were significantly smaller in the group treated with the angle stable tibial nail than they were in the group treated with standard unreamed tibial nailing. The limbs treated with the angle stable tibial nails returned to almost full weight-bearing during the period of the investigation, whereas those treated with standard nailing did not. Histomorphometric analysis, radiographic data, and mechanical testing showed superior bone-healing following treatment with the angle stable tibial nail.

CONCLUSIONS

Use of an angle stable tibial nail may help to reduce interfragmentary movements in vivo and thus lead to superior bone-healing compared with that following standard unreamed tibial nailing.

Systemic versus local application of gentamicin in prophylaxis of implant-related osteomyelitis in a rat model

Administration of perioperative antibiotic prophylaxis is a routine procedure in orthopedic surgery. Besides systemic prophylaxis, only few techniques are established for local application of antibiotics to reduce infection related to orthopedic implants. The aim of this study was to evaluate the efficacy of locally versus systemically applied gentamicin in a rat model (n = 60). For local application, the antibiotic was delivered from a biodegradable poly(D,L-lactide) (PDLLA) coating of titanium implants. The efficacy of local prophylaxis was compared to a systemic single shot application of gentamicin as well as a combination of both administrations. Half of the animals received a weight-adopted single shot application of gentamicin 30 min prior to surgery. At surgery, the medullary cavities of the tibiae were contaminated with Staphylococcus aureus (10(2) colony forming units /CFU) and titanium Kirschner wires were implanted into the medullary canals. The implants were either uncoated, PDLLA coated, or coated with PDLLA + 10% w/w gentamicin. The animals were followed up for 42 days. X-ray examinations were performed; body weight, temperature, and the clinical condition were determined. After sacrifice, infection was evaluated by histological and microbiological analysis. All animals treated with uncoated or PDLLA-coated Kirschner wires without systemic application of the antibiotic developed osteomyelitis and all cultures of implants were tested positive on S. aureus. Implant-related osteomyelitis could be prevented by prophylaxis of systemically applied gentamicin in 15% of animals. In contrast, local application of gentamicin delivered from a PDLLA coating was more effective. Onset of infection could be prevented in 90% of animals treated with gentamicin coated Kirschner wires, and in 80% of the animals that were treated with a combination of local and systemic application. The local application from PDLLA-coated implants might support systemic antibiotic prophylaxis in preventing implant-associated osteomyelitis.

Determination of muscle loading at the hip joint for use in pre-clinical testing

The stability of joint endoprostheses depends on the loading conditions to which the implant-bone complex is exposed. Due to a lack of appropriate muscle force data, less complex loading conditions tend to be considered in vitro. The goal of this study was to develop a load profile that better simulates the in vivo loading conditions of a "typical" total hip replacement patient and considers the interdependence of muscle and joint forces. The development of the load profile was based on a computer model of the lower extremities that has been validated against in vivo data. This model was simplified by grouping functionally similar hip muscles. Muscle and joint contact forces were computed for an average data set of up to four patients throughout walking and stair climbing. The calculated hip contact forces were compared to the average of the in vivo measured forces. The final derived load profile included the forces of up to four muscles at the instances of maximum in vivo hip joint loading during both walking and stair climbing. The hip contact forces differed by less than 10% from the peak in vivo value for a "typical" patient. The derived load profile presented here is the first that is based on validated musculoskeletal analyses and seems achievable in an in vitro test set-up. It should therefore form the basis for further standardisation of pre-clinical testing by providing a more realistic approximation of physiological loading conditions.

[Shock trauma room diagnosis: initial diagnosis after blunt abdominal trauma. A review of the literature]

OBJECTIVE

Blunt abdominal trauma is most common in the polytraumatized patient and beside neurocranial trauma one major determinant of early death in these patients. Therefore, immediate recognition of an abdominal injury is of life-saving importance.

METHODS

Clinical trials were systematically collected (Medline, Cochrane and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).

RESULTS

Clinical examination is not reliable for evaluation of abdominal injury. Abdominal ultrasound, especially if only focusing on free fluid (FAST) is not sensitive enough. Today, CT-scan of the abdomen is the gold-standard in diagnosing abdominal injury. Diagnostic Peritoneal Lavage (DPL) has a high sensitivity but in our region only is used in exceptional cases. The patient with continuing hemodynamical instability after abdominal trauma and evidence of free intraperitonial fluid has to undergo laparotomy.

CONCLUSION

After blunt abdominal trauma, initially ultrasound investigation should be performed in the emergency room. This should not only focus on free intraabdominal fluid but also on organ lesions. Regardless of the findings from ultrasound or clinical examination, the hemodynamically stable patient should undergo a CT-scan of the abdomen in order to proof or exclude an abdominal injury.

Diagnostische Wertigkeit der MR-tomographischen Knorpelläsionsdarstellung im Vergleich mit der intraoperativen Arthroskopie bei Calcaneusfrakturen

PURPOSE

To determine the diagnostic value of MRI in preoperative analysis and classification of cartilaginous lesions - especially of the posterior facet - in traumatic calcaneal fractures compared with intraoperative arthroscopy.

MATERIALS AND METHODS

Twenty-four consecutive patients with traumatic calcaneal fractures underwent prospective MRI of the subtalar joint surface using T1- and T2-weighted spin echo sequences and fat suppressed 3D gradient echo sequences in semicoronal slice orientation (1.5 T MRI). After randomization, the images were analyzed by two blinded and independent readers experienced in MRI. The results were compared with the intraoperative arthroscopic findings as to location and depth of the defects using the Outerbridge classification.

RESULTS

We examined 12 calcaneal fractures of type 2, 8 of type 3 and 4 of type 4 according to the Sanders classification. With respect to principal detection and exact classification, 67 of 96 (69.8 %) of all arthroscopic verified cartilaginous defects were diagnosed correctly by MRI. Disregarding the degree of the defects, 38 of 44 (86.4 %) chondral lesions were detected (sensitivity: 86.4 %, specificity: 86.5 %, diagnostic accuracy: 86.5 %). Considering the chondral lesions of degrees 3 and 4 together, the sensitivity was 86.0 %, the specificity 86.8 %, and the diagnostic accuracy 86.5 % . Assessing these degrees separately, the sensitivity was only 33.3 % for degree 3 and 58.1 % for degree 4, whereas the specificity was definitely higher with 82.1 % for degree 3 and 89.2 % for degree 4.

CONCLUSION

The MR detection of cartilaginous defects in calcaneal fractures has a sufficient diagnostic accuracy for planning the surgical intervention and assessing the long-term postsurgical prognosis.

[Biodegradable cage. Osteointegration in spondylodesis of the sheep cervical spine]

Bioabsorbable implants are commonplace in knee and shoulder surgery. Bioabsorbable poly(l-lactide-co-D,L-lactide) (PLDLLA) cage devices have potential benefits over autologous tricortical iliac crest bone graft and metallic cages for cervical spine interbody fusion. The purpose of this study was to compare interbody fusion of an autologous tricortical iliac crest bone graft with that of a bioabsorbable cage using a sheep cervical spine interbody fusion model. This study was designed to determine differences in (1) the ability to preserve postoperative distraction, (2) biomechanical stability, and (3) histological characteristics of intervertebral bone matrix formation. Sixteen full-grown Merino sheep underwent C3/4 discectomy and fusion. After 12 weeks, there was no significant difference between the results with the bioabsorbable PLDLLA cages and tricortical bone grafts. The cage also did not show advanced interbody fusion but did, however, show large osteolysis, which allows skepticism regarding the value of this bioabsorbable implant.

Differences in the fusion and resorption activity of human osteoclasts after stimulation with different growth factors released from a polylactide carrier

Previous in vivo studies were able to demonstrate the efficacy of locally released growth factors IGF-I, TGF-beta1, and BMP-2 from a poly(D,L-lactide) (PDLLA) implant coating on fracture healing. In vitro studies using human osteoblast-like cells showed an enhanced collagen-1 production due to growth factor application without an effect of the PDLLA on the investigated parameter. Both bone-forming osteoblasts and bone-resorbing osteoclasts are important during bone formation and fracture healing. The aim of this study was to investigate the influence of different growth factors and the polylactide coating into which they were incorporated on isolated osteoclasts. In vitro studies using human osteoclast-like cells derived from peripheral blood mononuclear cells (PBMNCs) were performed. Titanium K-wires coated with the lactide loaded with IGF-I and TGF-beta1 (alone and in combination) or BMP-2 were added to the culture in a non-contact manner and the fusion, resorption activity (pit formation assay), and TRAP 5b synthesis of the cells were analyzed. Differences in the effect of the growth factors were seen depending on the differentiation state of the cells. The fusion of the monocytes to multinuclear osteoclasts was significantly enhanced by the application of TGF-beta1 both alone and in combination with IGF-I. No effect was seen after application of IGF-I alone or BMP-2. The resorption activity of the osteoclasts analyzed on dentine chips was significantly enhanced after application of TGF-beta1 or BMP-2. These results indicate a differentiation-dependent effect of growth factors on osteoclasts. TGF-beta1 affects both the osteoclastogenesis and the activity of osteoclasts, whereas BMP-2 had an effect only on the activity of mature osteoclasts but not on the fusion of the PBMNCs.

[Interdisciplinarity in reconstructive surgery of the extremities]

From the perspective of trauma and orthopedic surgery interdisciplinary reconstructive surgery of the extremities encompasses different indications ranging from IIIB/Copen fractures with major segmental loss of bone and soft tissue, to arterial vessel in-jury necessitating vascular repair and to biological, plastic reconstructions following resections of musculoskeletal tumors. The interdisciplinary treatment concept including trauma-orthopedic surgery combined with vascular, plastic and neuro- as well as microsurgery has significantly decreased amputation rates and functional deficits thereby improving quality of life and long-term oncological outcome The multisdisciplinary management of both complex trauma and malignant bone/ soft tissue sarcoma of the extremity is an integral task of the surgical trauma or tumor center. Close interdisciplinary communication and expierence are the precondition for performance of a priority-adapted therapeutic strategy, low complication rates and improvement of overall prognosis.

[Treatment strategy for talus fractures]

Fractures of the talus are uncommon, but they present difficult treatment challenges. The classifications of fractures are based on conventional X-rays, but the CT scan is necessary for treatment decisions. Open fractures, displaced fracture dislocations, or extrusion of the talus must be reduced and stabilized as an emergency procedure. In all cases of displaced fractures, ORIF is indicated. The use of standardized approaches depends on the type of fracture and the soft tissue lesion. Precise anatomic reduction of all facets and reconstruction of the shape of the talus and stabilization with interfragmentary lag screws is the method of choice in almost all fractures. This procedure allows early mobilization postoperatively. The outcome is related to the degree of fracture displacement and the soft tissue lesion but may be poor due to inadequate treatment. Talus malunion, nonunion, and secondary deformity should be corrected early with preservation of the joints whenever possible. Arthrodeses should be restricted to the affected joints.

[Vertebral body replacement in spine surgery]

Autografts and allogeneous bone grafts as well as cages are used for the reconstruction of the anterior column after corpectomy. Recently, expandable cages for vertebral body replacement have been developed. Based on our own experience, the purpose of this study was to summarize the available biomechanical and clinical data of expandable corpectomy cages and to compare it with established fixation techniques. If used correctly, expandable cages offer several surgical advantages in comparison to non-expandable cages. However there were no significant differences between the biomechanical properties of expandable and non-expandable cages. Additionally, design variations of expandable corpectomy cages did not show any significant impact on the biomechanical stability. Currently available mid-term clinical and radiological data on the treatment of fractures, metastasis and infection of the cervical, thoracic and lumbar spine demonstrated no significant difference between expandable and non-expandable cages. However, the increased stress-shielding effect of expandable cages compared to non-expandable cages might result in a deterioration of the long-term clinical outcome.

Locked internal fixator: sensitivity of screw/plate stability to the correct insertion angle of the screw

OBJECTIVE

Internal fixators with angular stability have been developed to provide high stability without compression of the plate on to the bone. Angular and axial stability of a plate-screw construct can be achieved using a conically threaded screw head undersurface and a corresponding conically threaded plate hole. Furthermore, the insertion angle of the screw must correspond precisely to the axis of the screw hole. This is not always achieved in clinical practice and may result in screw loosening. The objective of this study was to examine the relationship between the stability of the locked screw-plate on the insertion angle of the screw.

METHODS

Locking screws were inserted in an isolated (Point Contact Fixator, PC-Fix) or combined (Locking Compression Plate, LCP 4.5) locking hole with the use of an aiming device. The optimal insertion angle for these plates is perpendicular to the plate surface. The screws were inserted with an axis deviation of 0 degrees (optimal condition), 5 degrees , and 10 degrees respective to the optimal angle (variance +/- 1 degrees ). The samples were tested under shear or axial (push out) loading conditions until failure occurred. An Instron materials testing machine was used.

RESULTS

Locking screws inserted in the isolated locking hole (PC-Fix) showed a significant decrease of failure load if inserted at 5 degrees and 10 degrees angle. Using an optimal insertion angle (0 degrees ), failure load was 1480 +/- 390 N, with 5 degrees axis deviation 780 +/- 160 N, P = 0.0001, and with 10 degrees axis deviation 550 +/- 110 N, P = 0.0001. Screws inserted in the combined locking hole (LCP) also showed a significant decrease of push-out force of 77% (4960 +/- 1000 N versus 1120 +/- 400 N) with 10 degrees axis deviation. Compared to optimal insertion angle (0 degrees ), bending load to failure did decrease up to 69% (1240 +/- 210 N vs. 390 +/- 100 N) with 10 degrees axis deviation.

CONCLUSION

A locking head screw exhibits high stability with a moderate axis deviation in the angle of insertion of up to 5 degrees . However, there is a significant decrease in stability with increasing axis deviation (>5 degrees ). An aiming device is recommended to provide optimal fixation with angular stability.