Search PubMed⌕ Search

Biomedical subjects

A N Witt

Publications and source records attributed to A N Witt.

At least 19 recordsLinked to original sources
PubMed1979

[Solitary bone cysts of the ulna (author's transl)].

The solitary bone cysts occurs most frequently in the upper humerus and femur in 75% of the cases, and it is very seldom located in the ulna, in 0.5--1.5%. This report deals with the treatment results of two children, five and six years old, suffering from solitary bone cysts of the lower end of the ulna. In one case a subtotal resection of the cyst was carried out and the defect was bridged with an autologous iliac bone graft. In the other case the patient was treated by curettage, and the defect was filled in with an autologous bone graft and cancellous bone out of the tibia. In both cases complete cure of the tumorlike lesion was obtained and no loss of function or deformity of the forearm was observed 12 and 16 years after operation. In the X-ray picture at that time there was no alteration on the length, form or structure of the bone.

Bone Cysts↗
PubMed1979

Unhooking of GSB total knee during dislocation of the patella.

This is a case report of a special and undoubtedly rare complication occurring in a hinge joint with a moving instant center such as the GSB total knee joint. The preoperative situation, the history of the incident and the operative report are being described as well as a radiological follow-up. The mechanism of unhooking of the tibial shaft from its junction with the femoral stem during dislocation of the patella is being reconstructed.

Aged↗
PubMed1979

[Problems of alloplastic joint replacement (author's transl)].

Nowadays artificial joint substitution can be assessed as a definite part of orthopedic surgery. The good primary results must not obscure the fact that in spite of great progress in the field of endoprosthesis, numerous problems must still be considered unsolved. Most important are the problems associated with anchoring the implant into living bone tissue. New ways of cement-free anchorage are being sought. The presentation of possible alternatives and their indicative limitation to alloplastic joint substitution shows that there are possibilities which can be carried out before a possible artificial joint substitution or instead of it. Since joint substitution is still in a phase of development, further advances may be expected in the future.

Arthrodesis↗
PubMed1979

[Intra-articular or extra-articular substitution of cruciate ligament--a critical study (author's transl)].

Intra- and extra-articular methods of cruciate ligament substitution are available for treating old anteromedial knee-joint instability. Twelve patients with intra-articular cruciate ligament substitution (median third of the patellar ligaments as free transplant) and 24 patients with extra-articular cruicate ligament substitution (operation according to Nciholas) were examined with particular reference to improved stability as follow-up examinations, the results being subjected to comparative evaluation. Intra-artricular cruciate ligament substitution reduces or eliminates the pre-operative instability of the joint which is due to insufficiency of the cruciate liagment, whereas the extra-articular cruciate ligament substitution produces a significantly more frequent reduction of elimination of the instability of the valgus position and of the anteromedial instability. The combination of both methods to remove anteromedial instability of the knee joint may seem a very useful solution of the problem, but it should be limited to a restricted group of patients because it involves also contain disadvantages which make it unsuitable for indiscriminate application.

Aftercare↗
PubMed1978

[An implantable femur distractor for operative leg lengthening (author's transl)].

A new femur distractor has been developed, lengthening the leg. This instrument is electronically controllable and can be implanted totally. It is possible to regulate transcutaneously by radio control the operation "forward motion", "stop" and "backward motion". After testing this instrument in sheep, the lengthening of human femur by this system can be introduced.

Bone Lengthening↗
PubMed1977

[Osteosynthesis with hinge joints and methylmethacrylate (author's transl)].

Six cases have been described where an osteosynthesis was performed using the stem of a hinge knee joint in combination with methylmethacrylate and other osteosynthetic devices (screws, wires). Need for an osteosynthesis existed because of pseudarthrosis after supracondylar and high tibial osteotomies, intraoperative fracture for implantation of a total knee, reimplantation after deep infection, and fatigue fracture after a total knee. The advantage of the procedure lies in early mobilisation and weight bearing. We do not believe in reimplantation after an infected prosthesis. Instead, we recommend fusion after implant removal.

Aged↗
PubMed1977

[Results of animal experiments with an implantable femur distractor for operative leg lengthening (author's transl)].

A new femur distractor for operative leg lengthening has been developed. The new instrument consists of an electronically controllable distractor set including a power unit and a two-part guide rail. The whole system can be implanted totally and gives rigid fixation throughout the period of distraction. The operations "forward motion", "stop" and "backward motion" can be regulated transcutaneously by radio control. A prototype especially developed for animal experiments has been tested successfully in sheep.

Animals↗
PubMed1977

[Osteosarcoma].

Explore the source record for details and available documents.

Angiography↗
PubMed1977

[The unstable knee joint--aspects in basic research, diagnosis and therapy (author's transl)].

The increase of knee lesions within the last years has provoked a generally more intensive discussion about the functional anatomy, the biomechanics and the pathophysiology of the capsule and ligaments of the knee joint. Several authors have stressed the importance of the active and passive factors, stabilizing the knee joint. The injury to a single element leads to different instabilities, as proven by meticulous clinical and radiological diagnostic procedures. The progress in the treatment of fresh and old injuries of knee ligaments is connected with the names of O'Domoghue, Slocum, Larson, Hughston, Nicholas and Trillat. For a fresh completely ruptured ligament surgery is recommended. Torn menisci are reattached whenever possible. An initial graft can be necessary for ruptures of the anterior cruciate ligament. Complex injuries, which are found most frequently, have to be dealt with completely. Old injuries of capsule and ligaments may require a plastic reconstruction. For the reconstruction of the anterior cruciate ligament it has been proven useful to take distally attached tendons of the pes anserinus group as well as the free graft from the central 1/3 of the patellar ligament. Rotational instabilities have to be dealt with according to the type of instability. The techniques of Slocum and Larson and the "five in one" reconstruction by Nicholas have to be emphasized as treatment of the anteromedial rotational instabilities. McIntosh has shown a procedure which seems to be successful for anterolateral rotational instabilities. Several techniques have been compared with our own experiences and late results studied. The point is stressed that further progress has to be made for the treatment of injuries to ligaments of the knee.

Adult↗
PubMed1977

[Muscular absorption of low frequency resonance in animal experiments (author's transl)].

For the further clarification of helicopter pilot's spinal troubles caused by vibration the muscular absorption was examined with the help of animal experiments. On a swinging-table acceleration values were measured in Pirbright cavies; at first this was done under a defence reaction of the muscles, and in second experiment under maximum muscular relaxation. In the tense animal the resonance occurring at 5 Hz was almost completely absorbed, whereas in the relaxed animal a clear resonance--curve could be developed at 5 Hz. On the other hand vibration at a higher frequency up to 15 Hz were to an increasing extent better absorbed in the relaxed animal than in animal with a muscular defence reaction. For this reason the protective function of a not fatigued musculature for the defence of especially badly tolerated resonance vibrations is being discussed.

Animals↗
PubMed1976

[Biomechanical and clinical studies of the transnaviculo-lunar resection arthroplasty (Steinhäuser operation) (author's transl)].

In advanced injuries of the proximal carpal row there is a therapeutic alternative to other methods of treatment--the Transnaviculo-Lunar Resection Arthroplasty of J. Steinhäuser. This operation gives the possibility to form a new joint by removing the os lumatum and the proximal two thirds of the os naviculare. The result is a painless new wrist which has a good range of motion. Since 1968 six Steinhäuser operations have been performed by attending orthopaedic surgeons of the "Orthopädische Klinik München Harlaching" follow-up study reports this clinical and radiographic results as well as the biomechanical fundamentales of the new wrist. The objective clinical and radiographic criterions, the subjective satisfaction of our patients and the biomechanical stability of the new wrist have shown, that there is a good prognosis of the Steinhäuser operation.

Adult↗