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Biomedical subjects

H Tscherne

Publications and source records attributed to H Tscherne.

At least 271 records · Page 15Linked to original sources
PubMed1990

[Arthrolysis of the hip joint in para-articular calcification and ankylosis].

Para-articular ossification of the hip joint represents a severe complication after hip surgery for joint replacement or various forms of trauma. It is always accompanied by tremendous loss of function and is therefore disabling for the patient. The results of past years have drastically reduced this complication in high-risk groups-recurrent joint replacement, acetabular fractures, severe head injuries-by means of hip irradiation and non-steroidal anti-inflammatory medication. In cases, in which significant functional disability results from heterotopic bone formation, it is possible to restore function of the hip joint through surgery. The diagnostics, preoperative planning, surgical therapy, and postoperative treatment protocol are presented.

Ankylosis↗
PubMed1990

[Current status of the treatment of distal radius fracture].

The problems encountered in the treatment of fractures of the distal radius lie in the frequent redislocation even after correct reduction. The ASIF classification should be used for a fracture-oriented therapeutic approach. Therefore, only fractures that are not dislocated should be treated conservatively. The majority of fractures require closed or open reduction followed by internal fixation. Articular fractures, in particular, require precise reduction of the articular surface. Following the reduction the fractures should be stabilized, usually with Kirschner wires. The more severe fractures--especially those falling in C1-C3 according to the ASIF classification--can be adequately treated by open reduction with a dorsal or volar approach and subsequent stabilization with the T plate, most often combined with other methods of internal fixation. Open fractures and complex traumas of the upper extremity should be treated by means of a fixateur externe for 2-4 weeks, followed by a change of treatment; the basic decision is usually between internal fixation with plates and further conservative treatment alone. The relatively poor long-term results obtained with treatment of distal radial fractures require that therapeutic guidelines be elaborated for the treatment of these fractures.

Bone Plates↗
PubMed1990

[Pathophysiology of open fractures and principles of their treatment. Review].

Authors have worked out in detail the problems of fractures associated with the injury of soft tissues. They use their own classification dividing these fractures into two major groups, and namely open and closed fractures. In each group they distinguish 4 degrees of severity of the injury of soft tissues. Of decisive importance for both the final result and the course of the treatment is the method of treatment which starts already on the scene of the injury. The whole therapeutical management up to the actual operation has several successive phases. The way of osteosynthesis can be decided upon only after the primary treatment of the wound which makes it possible to evaluate properly the condition of soft tissues and the contamination of the wound. Of vital importance is the radicalism of the primary treatment and the removal of all necrotic tissues. Potential defects can be temporarily covered with artificial skin and permanently with skin grafts or muscular, myocutaneous or fasciocutaneous flaps.

Arm Injuries↗
PubMed1990

[Functional therapy in treatment of fractures and joint injuries].

Full and timely restoration of the function of an injured segment of the locomotor system is the treatment goal for all fractures and joint injuries. Functional aspects therefore have to be considered, when operative or conservative forms of treatment are chosen for a particular injury. We define a treatment as purely functional if the involved limb is either not immobilized at all or whenever the immobilization is incomplete and for a limited time only. At least partial function of the involved segment is therefore restored during the treatment. Purely functional treatment ist most applicable for stable fractures. Stable can be defined as the property of biological tissues to withstand physiological loads. Many joint injuries such as AC separation, ankle ligament rupture, Achilles tendon rupture, and isolated rupture of the medial collateral ligaments of the knee can also be treated functionally.

Braces↗
PubMed1990

[Stabilization of open tibial fracture by an external fixator. Advantages through supplemental screw osteosynthesis].

One hundred thirty-two open tibial shaft fractures were treated by unilateral external fixation. In order to evaluate the usefulness of supplemental lag screw fixation, we compared forty-four reexamined fractures in which only external fixation was utilized with fifty-five reexamined fractures, stabilized with supplemental lag screws and external fixation. We did not find significant differences in time to full-weight bearing (17.1 vs. 15.6 weeks), time to union (18.7 vs 18.0 weeks), incidence of delayed union [as defined by time to union over 32 weeks (10.9% vs. 11.4%)], incidence of osteomyelitis (5.4% vs. 4.5%), or incidence of malunion [axial malalignment greater than 5 degrees (12.7% vs. 11.4%)]. Clinically significant differences were found demonstrating a twofold increase in refracture rate in the group with supplemental lag screws (10.9% vs. 4.5%) and requiring twice as many bone grafting procedures to achieve union (65.5% vs. 29.5) than did the group treated by external fixation alone. Therefore we do not recommend the routine use of supplemental lag screw fixation.

Adolescent↗
PubMed1990

[Synovectomy in knee infection. Late results].

When short-term conventional treatment of pyogenic knee-joint infections does not relieve the symptoms, in most cases the patients can be cured with an synovectomy within a few weeks. In this procedure, the infected site, the synovial membrane, is excised. Immediately after the operation, functional treatment starts to improve joint mobility and cartilage nutrition. Of 17 synovectomies followed up after an average of 9.5 years, 10 were free of pain, 13 patients were able to walk without restriction, 12 could flex their knee more than 120 degrees, and 9 knees showed no radiographic signs of osteoarthritis. This 10-year follow-up shows that early synovectomy and functional treatment can lead to good long-term results. Therefore, this procedure can be recommended.

Adult↗
PubMed1990

[The AIDS problem in accident surgery].

In trauma surgery there is a particularly high proportion of patients in the age group most at risk of infection with AIDS. The result of an epidemiological study in our patients (HIV screening of all patients scheduled for surgery at a trauma center over 18 months) showed a prevalence of 0.1%. Specific therapeutic strategies must be developed to deal with the weakened immunity of HIV-infected patients. Fracture treatment in HIV-infected hemophiliacs is a special problem. Homogenous bone transplantation is described with reference to HIV. The particular danger of injury in trauma surgery is also investigated. The chain of infection is illustrated and used to demonstrate the precautions that can be taken against nosocomial HIV infections. Following infection with fluids containing HIV, specific measures must be taken. The legal aspects of HIV-antibody testing in the Federal Republic of Germany are elucidated. Finally, the problems of general preoperative HIV-antibody testing are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Healing phases in autogenous posterior cruciate ligament replacement. A decision aid for after-care. A biomechanical and histologic study].

In a sheep model for reconstruction of the posterior cruciate ligament using the central one-third of the autogenous patellar tendon and immediate mobilization, the incorporation course was studied biomechanically, histomorphometrically and radiographically at eight different points in time up to 1 year after surgery. Four different phases of autograft healing were demonstrated on the basis of the histological events. The biomechanical data were correlated with the morphological findings. Phase 1--necrosis--was characterized by a maximum of necrotic autograft tissue 2 weeks postoperatively. Initially, graft strength was determined by the surgical fixation strength. During phase 2--revitalization--the autograft showed cellular proliferation and revascularization, starting from the periphery. The autograft was determined to be weakest during this phase. Phase 3--collagen formation--revealed a marked increase in newly formed collagen tissue between weeks 12 and 16. A significant increase in maximum load and stress was measured. In phase 4--remodeling--the longest phase, the collagen tissue appeared more compact and less cellular. The fiber bundles were arranged more longitudinally. However, the biomechanical properties remained clearly below that of a normal posterior cruciate ligament.

Animals↗
PubMed1989

Biological aspects of long-term failure of autografts after cruciate ligament replacement.

The alterations of the ultrastructure of the posterior cruciate ligament autograft of patellar tendon origin were examined in a sheep model 1 year after surgery. The ultrastructure was also compared with that of the normal contralateral posterior cruciate ligament and patellar tendon. The most striking finding was the unimodal distribution of the collagen fibrils, with a predominance of loosely packed thin fibrils in the central portion of the autograft. The results suggested that the remodeled autograft tissue became highly organized but never exhibited the ultrastructural features of a ligament. This could be responsible for the decreased biomechanical properties and the long-term failure of a patellar tendon autograft.

Animals↗
PubMed1989

Healing at graft fixation site under functional conditions in posterior cruciate ligament reconstruction. A morphological study in sheep.

The incorporation course at the fixation sites of a free patellar tendon graft used in posterior cruciate ligament reconstruction was examined in eight adult sheep. After surgery the sheep were functionally treated without any protection of the operated legs. Two, 6, 12, 16, and 26 weeks after surgery the sheep were killed and the character of biological attachment to bone at fixation sites was evaluated using macroradiography, high-resolution radiography, and routine histology. After 6 weeks good osseous incorporation of the bone pegs of free patellar tendon grafts could be demonstrated at the desired position.

Animals↗
PubMed1989

[Surgical treatment of chronic upper ankle joint instability in childhood].

The Department of Traumatology of the Hanover Medical School treated 347 patients having chronic instability or second stage rupture of the fibular ligament system, by surgery, during 1971 through 1986. Children were represented by one-seventh of the total number of patients only (13%; n = 44); however, in children the preoperative and intraoperative findings are different from normal findings and must be treated surgically in a special way. Whereas in adults old osseous/osteochondral ligament tears are apt to be rare (16% of the cases), they can be seen in children in almost every second case (18 of 44). Surgical approach requires a step-by-step procedure to achieve maximum stability and minimum functional loss. First Choice: Direct reconstruction of the ligament in case of ligaments which are present but have not healed correctly from a biomechanical point of view (e.g. pseudoarthroticosseous ligament tear) or in case of second-stage rupture (n = 20). Second Choice: Double periosteal flap plasty in case of necessary replacement of only one ligament (n = 13). Third Choice: Tenodesis of m. peroneus brevis using only half of the tendon chip while sparing the epiphysis if the condition persists for many years, or if ligaments cannot be reconstructed or replaced intraoperatively or if there is a combined instability of the ankle joint and the talo-calcaneonavicular joint (n = 11). In almost 90% of the cases very good to good results were obtained after five years, assessed according to a 100-point schema.

Adolescent↗
PubMed1989

[Distal radius fracture. Fracture stabilization with biodegradable osteosynthesis pins (Biofix). Experimental studies and initial clinical experiences].

K-wire stabilization and casting of unstable or intraarticular fractures of the distal radius has proven to be an effective method of treatment since many years. However the need of implant removal after fracture healing is a disadvantage of this method. For this reason we investigated on the use of biodegradable implants in a fracture model of the distal radius. The biomechanical testing with Polydioxanon-(PDS)-pins (Ethipin) showed too small primary stability for the use in vivo. Osteosyntheses with three Polyglycolacid-(PGA)-rods Biofix compared with three K-wires 1.6 mm on the other hand showed 82% initial stability. From May to September 1988 typical distal radius fractures in 11 patients have been stabilized with Biofix-rods. The result of primary reduction could be obtained in all cases. These first experiences suggested, that stabilization of distal radius fractures with Biofix-rods might alternatively be performed instead of K-wire pinning.

Adult↗
PubMed1989

[Reconstructive foot surgery following complex trauma of the foot].

Compound post-traumatic foot deformity may follow indirect, direct, or combined trauma. This is demonstrated by a number of case reports. Particularly during adolescence, primary injuries to the soft tissue, with neurovascular injury or compartment syndrome, and post-traumatic skin contractures can cause severe growth deformity at the site of the injury and distal to it. Compression screw arthrodesis, using the 6.5-mm cancellous screw with the triple arthrodesis and the 3.5-mm cortical screw with the Lisfranc arthrodesis, has particular significance. It is stable, it allows functional treatment later, and bone union takes place rapidly. The most important surgical principles in post-traumatic foot surgery are: precise reconstruction of the foot axes, the medial and lateral foot length, and the longitudinal and transverse arches, i.e., restitution of the normal foot anatomy.

Adolescent↗
PubMed1989

[Management of femur shaft fracture in the growth age with the fixateur externe].

Non-operative management is still the treatment of choice today for femoral shaft fractures in children. Indications for operative intervention would include: - the child with multiple injuries, particularly with severe head injuries, in those patients with severe soft tissue damage associated with the fracture; in cases where the reduction is difficult to maintain, as in subtrochanteric fractures; and in children who are not suitable for management with traction. Since 1984, 16 children have had their femoral shaft fractures stabilized by external fixation (Monofixateur) here in the Trauma Department of the Hannover Medical School. The mean age of the patients was 10.3 years (seven to sixteen years). All cases were closed fractures with mild or moderate soft tissue damage. Eleven of the patients had a multiple injury, and four had subtrochanteric fractures. The external fixation remained in place for a mean of 63 days in those patients exclusively treated by this method. In four of the earlier cases there was a Schanz's screw infection and three of these required removal of the external fixation and treatment in a hip spica. After modifying the technique of Schanz's screw insertion, no further infections were seen. Fourteen of the sixteen children were reviewed, with a mean follow up of 21.7 months. None of the children who had been completely managed by this fixation had any clinically relevant malalignment. Six cases had leg lengthening of up to two centimetres. Leg length differences were seen more frequently and more severely in those cases where external fixation was delayed.

Adolescent↗
PubMed1989

[Continuing education in a department system (Hannover Medical School)].

Among 100 surgical trainees (1/89; chief residents: n = 24) 34 finished their program (median age: 34.5 Y) after a mean of 6.3 years. During the program the trainees rotated in at least three different clinics and performed the required number of operations. Since 50% of the trainees are in the first 3 years of training 63.8% of all operations are currently performed by chief residents. This allows only three operations/month/trainee. Until 1988 the concept of qualified surgical training in a department was ensured. Due to an increase in trainees (+36%) the training will be prolonged in the near future.

Adult↗
PubMed1989

[Current state of functional therapy. Definition and indications].

Functional treatment can be defined as a form of therapy in which the involved segment of the locomotor system is either not immobilized at all or the immobilization is incomplete and lasts only for a limited time. Function of the involved segment is therefore restored during the treatment. Many fractures, especially those of the upper extremity, stable fractures as well as a number of joint injuries such as AC-joint dislocation, ankle ligament rupture and Achilles tendon rupture can be treated functionally. Functional Treatment is an integral part of regular conservative fracture treatment and also important for the operative management of fractures and joint injuries.

Fracture Fixation↗