Biomedical subjects

M H Hessmann

Publications and source records attributed to M H Hessmann.

13 recordsLinked to original sources

PubMed2005

The influence of bone allograft processing on osteoblast attachment and function.

In order to assess the influence of eight different sterilisation and disinfection methods for bone allografts on adhesion, proliferation, and differentiation of human bone marrow stromal cells (BMSC), cells were grown in culture and then plated onto pieces of human bone allografts. Following processing methods were tested: autoclavation (AUT), low-temperature-plasma sterilisation of demineralised allografts (D-LTP), ethylene oxide sterilisation (EtO), fresh frozen bone (FFB), 80 degrees C-thermodisinfection (80 degrees C), gamma-irradiation (Gamma), chemical solvent disinfection (CSD), and Barrycidal-disinfection (BAR). The seeding efficiency was determined after one hour to detect the number of attached cells before mitosis started. The cell viability was determined after 3, 7, and 21 days. Tests to confirm the osteoblastic differentiation included histochemical alkaline phosphatase staining and RT-PCR for osteocalcin. Human BMSC showed greatest attachment affinities for D-LTP-, 80 degrees C-, and CSD-allografts, whereas less cells were found attached to AUT-, EtO-, FFB-, Gamma-, and BAR-probes. Cell viability assays at day 3 revealed highest proliferation rates within the FFB- and 80 degrees C-groups, whereas after 21 days most viable cells were found in D-LTP-, 80 degrees C-, CSD-, and Gamma-groups. BAR-treatment showed a considerably toxic effect and therefore was excluded from all further experiments. Highest AP-activity and gene expression of osteocalcin were detected in the D-LTP-group in comparison with all other groups. In summary, our results demonstrate that cell adhesion, final population, and function of BMSC are influenced by different disinfection and sterilisation methods. Therefore, processing-related alterations of BMSC-function may be important for the success of bone grafting. The experimental setup used in the present work may be useful for further optimisation of bone allograft processing.

Alkaline Phosphatase↗

PubMed2005

[Internal fixation of proximal humerus fractures].

BACKGROUND: Intramedullary nails and angle-fixed plates have recently been used in proximal humerus fractures. Rigid implants might be associated with an increased risk of failure in osteoporotic conditions. METHODS: Unstable fractures of the surgical neck were created in 24 pairs of human humeri. The biomechanical properties of four implants were analysed. These were a nail with conventional interlocking (PHN-K), a nail with spiral blade interlocking (PHN-S), the T-plate, and an internal fixator with elastic screw properties (reference). The specimens were subjected to axial loading and torque. Stiffness, plastic deformity, and load to failure were assessed. RESULTS: The PHN-S was stiffer than the internal fixator. The PHN-K and T-plate were stiffer only during torque. Less subsidence was observed for the PHN-S. This implant failed at higher loads than the other implants. CONCLUSIONS: The PHN-S offers biomechanical advantages in unstable fractures of the surgical neck of the humerus. Elastic implant properties, however, are disadvantageous.

Aged↗

PubMed2005

[Complex pelvic trauma caused by an accidental side split].

Complex pelvic ring fractures are defined as injuries of the pelvic ring in association with lesions of the pelvic organs or the pelvic soft tissues. These injuries are typically caused by high-energy accidents. In contrast to the typical mechanism of injury a case is described in which a low energy trauma led to a complex pelvic ring trauma. An obese woman suffered an open-book injury of the pelvis with severe open urogenital soft-tissue damage by accidentally doing forced splits. Primary stabilization of the pelvic ring with external fixation and secondary internal fixation with a double-plate osteosynthesis of the symphysis led to a good clinical outcome concerning the osseous lesion. The urogenital injuries with rupture of the bladder, the urethra and the vagina led despite immediate urological management to an incontinence, which finally required definitive urine drainage via an ileum conduit.

Accidental Falls↗

PubMed2004

[Intramedullary osteosynthesis of the ulna in revision surgery].

The exact and adequate management of diaphyesal fractures of the forearm is necessary to ensure forearm motion. Unsatisfactory treatment can lead to loss of function and disability of forearm and hand movement, resulting in severe patient morbidity. Since the rotational and angulatory stresses at the fracture site are the superior factors which influence the outcome of the forearm fracture healing after surgical treatment, the implants must fulfill some general prerequisites including high biomechanical stability, less invasive surgical approach and adequate biological features. However, less clinical studies are known for cases of complicated ulnar fractures when additional revision surgery is necessary to restore form and function. Thus, the choice of implant in such difficult situations requires a profound knowledge and experience. In a series of seven clinical cases we report about the successful use of the ForeSight-nail in revision surgery of complicated ulnar fractures. The series include cases with refractures after plate removal, in-situ plate brokerage and a critical size bone non-union which were treated with interlocking intramedullary osteosynthesis technique.

Adult↗

PubMed2004

[Are angle-fixed implants with elastic properties advantageous for the internal fixation of proximal humerus fractures?].

There is a recent interest for the use of angle-fixed plates in the management of proximal humerus fractures. Rigid implants might be associated with an increased risk of cutting-out. In order to analyse the potential beneficial effects of the implant elasticity on fracture fixation, the biomechanical properties of a rigid and an elastic angle-fixed plating system were assessed in an experimental study. An unstable fracture of the surgical neck was created in 8 pairs of human humeri. Specimens were subjected to axial loading and torque. Stiffness, subsidence and load to failure were assessed. The implant with elastic properties was characterized by a lower torsional stiffness and a higher subsidence during axial loading and torque. This implant failed at lower loads than the rigid implant did. Elastic implant properties of angle-fixed plates have shown not to be advantageous for the management of fractures of the proximal humerus.

Bone Plates↗

PubMed2003

[Mortality, morbidity and functional outcome after open book and lateral compression lesions of the pelvic ring. A retrospective analysis of 100 type B pelvic ring lesions according to Tile's classification].

A retrospective study was made of 100 Tile type B and 122 type C pelvic ring lesions. Type B1-open book lesions occurred in 52 patients while 48 had lateral compression lesions of type B2 or B3. Only 13.1% of the patients showed no associated lesions. The frequency of associated neurological lesions in the B1 group with 21% was higher than in the B2/B3 group with 12%. The frequency of urologic lesions in group B1 was 9.6% but in B2/B3 patients it was only 2.1%. A total of 66% of B-lesion patients were stabilized with an external fixator. The frequency of secondary operative procedures was 23% in B1-patients and 6.25% in the B2/B3 group. Overall mortality was 10.4%: 5% in the B-group and 14.8% in the C-group. Outcome for patients with B2/B3 lesions was, with 92% excellent and good end results,much better than in patients with B1 lesions (74%). The inverse was true for radiologic results: 93% of the B1- but only 75% of the B2/B3-patients had an anatomical reduction. Open book lesions, lateral compression lesions and combined vertical stable lesions should be differentiated. We suggest that lateral compression lesions be characterized as B1 and open book lesions as B2 type injuries in the classification system of AO.

Adolescent↗

PubMed2003

Limb trauma with arterial injury: long-term performance of venous interposition grafts.

BACKGROUND: In contrast to arterial occlusive disease, data on long-term outcomes after vein grafts in limb trauma with arterial injury are sparse. PATIENTS: From 1991 through 2001, 22 trauma victims received 23 interposition vein grafts performed by an interdisciplinary team of trauma and vascular surgeons. Indications included both blunt and penetrating injuries with critical limb ischemia in the majority of cases. RESULTS: Operative treatment of the injured vessels (brachial n = 5, radial/ulnar n = 7, popliteal n = 6, tibial n = 3, pedal n = 2) encompassed venous interposition graft of either saphenous (n = 15) or cephalic vein (n = 8). All patients survived the operative procedure. 4 graft occlusions were noted and 3 major amputations had to be performed (one despite patent graft). 13 patients (76%) were available for duplex ultrasound examination after a mean follow-up of 59 months where patent grafts could be detected in all cases. CONCLUSION: A multidisciplinary approach ensures optimal treatment strategy of arterial injury in extremity trauma. Interposition vein grafts provide durable long-term results and should be attempted even in single-vessel injuries of forearm and lower leg.

Adolescent↗

PubMed2002

[Acetabular fractures in the elderly. Results of a sophisticated treatment concept].

Acetabular fractures in elderly patients are rare injuries, but their incidence is increasing. Poor bone quality due to osteoporosis and an increased operative risk due to concomitant disease are factors complicating surgical therapy. Literature does not provide generally accepted treatment protocols. In a 4-year period, 27 patients who were 65 years or older and who had an acute displaced fracture of the acetabulum were admitted to our department. Four minimally displaced and stable fractures were managed conservatively. Internal fixation was performed in 16 cases. According to the Merle d'Aubigné score, in 15 out of 18 surviving patients excellent or good results were found. Treatment strategy should be planned individually for each fracture, taking into account the patients biological age and general condition, fracture type, bone quality and associated injuries. Primary endoprosthetic replacement should only be considered when the acetabular bone stock allows stable cup fixation. Osteosynthesis in combination with early endoprosthetic replacement should be considered in acetabular fractures with associated femoral head or neck fractures or when significant articular steps and/or bone defects remain after open reduction and internal fixation.

Acetabulum↗

PubMed2002

Transverse fracture-dislocation of the sacrum: a diagnostic pitfall and a surgical challenge.

Transverse fracture-dislocations of the sacrum are rare. Associated lesions of the lumbosacral spine as well as neurological injuries are common. Conventional radiographs of the pelvis often fail to clearly visualize the fracture. Delayed diagnosis increases the risk of progressive neurological disfunction. True lateral sacral views and CT-scans with 3-dimensional reconstructions are very helpful in establishing the full extent of the injury. These examinations should be considered in all patients with a history of high energy trauma and clinical signs indicating lumbosacral injury, such as severe low back pain and neurological disturbances of the lower extremities. The management of transverse sacral fracture-dislocations with or without associated neurological damage is controversial. Conservative treatment is associated with a high rate of persistent deformity and residual neurological dysfunction. Surgical management allows for anatomical fracture reduction, stable fixation and revision of the spinal canal and lumbosacral nerve roots. The dorsal approach is preferred. Two patients with transverse sacral fracture-dislocations and neurological disturbances are presented. One patient had an additional fracture-dislocation of the lumbar spine at the L4L5 level with intrusion of the lumbosacral spine into the pelvis. Both lesions in this patient were successfully stabilized using an internal fixator system. The other patient presented with a bilateral transforaminal sacral fracture. The transverse component was not recognized on the initial radiographs, which resulted in loss of reduction and progressive neurological disfunction after sacroiliac screw fixation.

Adult↗

PubMed2002

Staged reconstruction of pelvic ring disruption: differences in morbidity, mortality, radiologic results, and functional outcomes between B1, B2/B3, and C-type lesions.

OBJECTIVE: To analyze injury pattern, surgical therapy, radiologic results, and functional outcome in unstable B-type and C-type pelvic ring fractures. DESIGN: Retrospective study. SETTING: Level I University Trauma Center. PATIENTS: Two-hundred-twenty-two consecutive patients, admitted during a nine-year period with unstable B-type (n = 100) and C-type (n = 122) pelvic ring injuries, of whom 122 (61.3 percent of surviving patients) were eligible for evaluation with a minimum follow-up of one year. INTERVENTIONS: Staged reconstruction dependent upon injury pattern. Emergency external compression of the pelvic ring in case of hemodynamic instability. Management of associated lesions. Secondary open reduction and internal fracture fixation. MAIN OUTCOME MEASURES: Assessment of perioperative and postoperative mortality and morbidity depending on fracture pattern. Fifty-five B-type and sixty-seven C-type lesions were evaluated clinically and radiologically an average of 21.6 months after trauma. RESULTS: Perioperative mortality was 5 percent in B-type and 15 percent in C-type fractures. External fixation was part of the definitive treatment in 52 percent of B-type and in 38 percent of C-type lesions. Planned secondary operative procedures were performed in 15 percent of B-type and in 26.2 percent of C-type fractures. Radiologic results were anatomic in 93.5 percent of B1, 75 percent of B2/B3, and 62.7 percent of C-type lesions. Functional results were excellent or good in 74 percent of the B1, 92 percent of the B2/B3, and in 71 percent of the C-type fractures. CONCLUSIONS: Unstable pelvic ring fractures require a staged approach. Mortality is higher in C-type than in B-type lesions. Functional outcome is worse in C-type than in B-type lesions. Within the B-type group, B1 lesions have a worse functional end result than B2/B3 fractures. These findings are not only related to the stability and symmetry of the pelvic ring, as seen in the radiologic picture, but also depend on the severity and amount of damage to the soft tissues around the pelvis.

Adolescent↗

PubMed2001

[Osteosynthesis techniques in proximal humeral fractures].

Although proximal humeral fractures are common injuries, there is no generally accepted strategy as to how unstable and displaced two- to four-part fractures should be managed. Surgical therapy is in a conflicting situation between the requirement for anatomical fracture reduction and stable fixation, on the one hand, and the necessity for minimal intraoperative damage to the soft tissue and arterial vascularization of the humeral head in order to avoid avascular necrosis on the other. Whereas minimally invasive procedures using closed or percutaneous reduction and fixation techniques are advantageous for protection of the arterial blood supply of the proximal humerus, plate fixation provides superior fixation stability. Plate fixation seems to be associated with a reduced risk of avascular necrosis when indirect reduction techniques are used. Poor results in the operative management of humeral head fractures are often seen in association with malunion. There is therefore a tendency towards the use of implants with angular stability in order to reduce the risk for secondary loss of reduction during functional after treatment. Innovative new plates and intramedullary nails that provide superior stability of fixation of the humeral head fragment have been actually introduced into clinical practice. Together with the specific patient and fracture characteristics, the final result of operative management, however, remains mainly related to the knowledge and operative skills of the trauma or orthopaedic surgeon who deals with these proximal humeral fractures.

Bone Plates↗

PubMed1999

[Acetabulum fractures].

Each acetabular fracture means a huge intellectual and a demanding technical challenge for the surgeon on charge. Because the hip joint is situated within a complex three-dimensional structure the diagnostics of its lesions are difficult. Three conventional X-ray views enable the recognition of a specific fracture type, computertomographic cuts give a detailed view on the type and the severity of the cartilage lesions, threedimensional reconstructions make a clear spatial imaging of the fracture configuration possible. These different radiological images are not superfluous, but complementary. Preoperative planning involves the choice of the approach and of the type of osteosynthesis. The Kocher-Langenbeck and the ilioinguinal approach are non-extensile approaches. They enable the internal fixation of the big majority of acute lesions. Each approach has its specific, well defined field of indications. Specific complications of the Kocher-Langenbeck approach are sciatic nerve palsy and periarticular ossifications. Complications of the ilioinguinal approach are damage to the iliac vessels and/or lymph vessels, to the lateral femoral cutaneous nerve and to the femoral nerve. Aseptic necrosis of the femoral head is a common complication of both approaches, but has to be differentiated from wear of the femoral head due to friction. Indications for the extended approaches are limited, their risks and complications are higher than in the non-extensile approaches. An active aftertreatment is only possible after a stable fracture fixation, the characteristics of physiotherapy are dependent on the type of approach. In a personal series of 225 operatively treated acetabular fractures, 128 were stabilized through a Kocher-Langenbeck approach. 103 of these patients could be reviewed after an average time of 25.9 months. 73.8% of them had an excellent or good result in the classification of Merle d'Aubigne. 61 fractures were fixed through an ilioinguinal approach. 48 could be reviewed after a mean time of 23 months. 85.4% obtained an excellent or good result in the functional scale of Merle d'Aubigne. These results are comparable with similar larger studies in the recent literature. The acetabular fracture in the elderly is a specific and rare type of lesion. When operated on quickly, open reduction and internal fixation can also give gratifying results. Alternative methods as primary or secondary total hip arthroplasty are at least as demanding for the patient and are combined with a high percentage of loosening of the acetabular component. The rarity and complexity of acetabular fractures asks for a specific teaching and learning with a experienced acetabular surgeon.

Acetabulum↗

PubMedDate not supplied

The benefit of multislice CT in the emergency room management of polytraumatized patients.

The early treatment of polytraumatized patients needs an effective and standardized approach. Reducing time requirements for the primary diagnostic evaluation is a major concern in the early phase of polytrauma management. Multislice-CT (MSCT) is a quick and reliable method for the initial diagnostic evaluation. Computed tomography provides more detailed and more consistent information than conventional radiography. It has the great advantage of allowing rapid examination of the head, vertebral column, chest, abdomen and pelvis during one single examination. The CT-suite needs to be adequately equipped for resuscitation and reanimation, which is done parallel to the radiological investigations. Since polytrauma management is based on a multidisciplinary approach characterized by a coordinated interaction between trauma surgeons, anaesthesiologists and radiologists, members of all involved disciplines need adequate teaching. Guidelines and algorithms contribute to optimize the early management.

Humans↗