Biomedical subjects
K Klaue
Publications and source records attributed to K Klaue.
Planovalgus and cavovarus deformity of the hind foot. A functional approach to management.
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"Healing of a segmental defect in the rat femur with use of an extract from a cultured human osteosarcoma cell-line (Saos-2). A preliminary report".
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Radiographic assessment of the second metatarsal: measure of first ray hypermobility.
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Determination of acetabular coverage of the femoral head with use of a single anteroposterior radiograph.
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Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity.
Today, bunion surgery is still controversial. Considering that a bunion deformity in fact may be a result of multiple causes, the rationale of the currently applied techniques of surgical treatment has not been conclusively demonstrated. In view of the known hypermobility syndrome of the first ray that results in insufficient weightbearing beneath the first metatarsal head, the relationship between this syndrome and hallux valgus deformity has been investigated. The results suggest a direct relationship between painful hallux valgus deformity and hypermobility in extension of the first tarsometatarsal joint. A pathological mechanism of symptomatic hallux valgus is proposed that relates this pathology with primary weightbearing disturbances in the forefoot where angulation of the first metatarsophalangeal joint is one of the consequences. The alignment of the metatarsal heads within the sagittal plane seems to be a main concern in many hallux valgus deformities. As a consequence, treatment includes reestablishing stable sagittal alignment in addition to the horizontal reposition of the metatarsal over the sesamoid complex. As an example, first tarsometatarsal reorientation arthrodesis regulates the elasticity of the multiarticular first ray within the sagittal plane and may be the treatment of choice in many hallux valgus deformities.
Extra-articular augmentation for residual hip dysplasia. Radiological assessment after Chiari osteotomies and shelf procedures.
The Chiari osteotomy and various shelf procedures are used to augment the weight-bearing area in dysplastic acetabula. The new articular surface derives by metaplasia from the acetabular rim and joint capsule, and is therefore of poorer quality than congruous hyaline cartilage. We reviewed 32 patients after augmentation procedures, using conventional radiographs and three-dimensional reconstruction from CT scans. We showed that Chiari osteotomy and shelf procedures generally achieve less than complete cover, especially over the posterolateral quadrant of the femoral head. Our results suggest that alternative methods which reorientate the whole of the acetabulum are the treatment of choice. Augmentation procedures remain as a salvage option when reorientation is inappropriate or the original hyaline cartilage surface is absent, as in subluxed joints with a secondary acetabulum. Computerised assessment is recommended before operation to assess existing cover and the possible extent of provision of new cover.
Internal fixation with a self-compressing plate and lag screw: improvements of the plate hole and screw design. 1. Mechanical investigation.
For a number of years, self-compressing plates, with oval holes and using special drill guides, have been in use. Recently, the advantages offered by lag screw interfragmentary compression inserted through the plate have gained prominence. Often such screws are inserted in an inclined position toward the fracture plane for better efficiency. It has also become evident that inclined screws placed into oval holes undergo a displacement toward the fracture. Efforts to improve the effect of this technique have led to a new plate and screw interaction that is described herein. The result is versatility and efficiency of the fracture fixation.
Internal fixation with a self-compressing plate and lag screw: improvements of the plate hole and screw design. 2. In vivo investigations.
A mechanically improved design of bone plate and screw was compared in vivo with conventional plate fixation. This method was investigated biologically in a standardized osteotomy model on sheep tibiae. It was found that maintenance of reduction of an osteotomy was facilitated and there was no adverse effect of this fracture fixation system on bone remodeling. The modified implant permits the reduced surgical approach to the bone through one plane and optimal fixation of the fracture or osteotomy.
The acetabular rim syndrome. A clinical presentation of dysplasia of the hip.
The acetabular rim syndrome is a pathological entity which we illustrate by reference to 29 cases. The syndrome is a precursor of osteoarthritis of the hip secondary to acetabular dysplasia. The symptoms are pain and impaired function. All our cases were treated by operation which consisted in most instances of re-orientation of the acetabulum by peri-acetabular osteotomy and arthrotomy of the hip. In all cases, the limbus was found to be detached from the bony rim of the acetabulum. In several instances there was a separated bone fragment, or 'os acetabuli' as well. In acetabular dysplasia, the acetabular rim is subject to abnormal stress which may cause the limbus to rupture, and a fragment of bone to separate from the adjacent bone margin. Dysplastic acetabuli may be classified into two radiological types. In type I there is an incongruent shallow acetabulum. In type II the acetabulum is congruent but the coverage of the femoral head is deficient.
[Post-traumatic hindfoot reconstruction--principles and selected examples].
Besides rheumatoid diseases, fractures are the most frequent cause of painful static problems about the hindfoot. Even when the ankle, the subtalar or the midtarsal joints are not involved directly in the fracture, they likely degenerate secondarily because of the malalignment. The aim is to restore normal morphology of the foot with reorienting arthrodeses using stable internal fixation by screws and cortico-cancellous autologous bone grafts which allow early partial weight bearing. There are three surgical approaches which can be used alone or in combination: antero-medial along the medial column, lateral (Ollier), and postero-lateral along the heel cord.
[Soft tissue preservation and reconstruction in non-supporting foot parts].
The foot has two skin surfaces which differ on a morphological and functional basis. The plantar skin is a highly specialized organ which has a dash-pot-like effect in weight bearing. The skin which does not participate in weight bearing covers tendons and a very rich syndesmotic complex. The internal soft tissue is segmented in tiny compartments and therefore ist not extensible. The skin and the rather thin subcutaneous layer are not extensible either because of the proximity and the rigidity of the underlying structures. In consequence, trauma to the soft tissue of the foot may cause compartment syndromes and skin defects, or secondary unstable scars which impede function. Compartment syndromes must be recognized early and treated by immediate release. Fresh skin defects need early coverage when tendons and joints are exposed. There is a variety of local flaps which are evenly good for replacement of retracting scars.
[Current surgical therapy of congenital clubfoot].
The operative treatment of congenital club foot deformity in childhood consists of a release of soft tissues which are retracted in fibrous "knots" at the hindfoot and midtarsus. This release is more or less extensive, depending on the importance of the contracture and allows reduction of the triple deformity i.e. varus and equinus of the hindfoot and adduction at the midtarsus. Surgery is performed preferably before walking commences in order to take advantage of the functional self-treatment by bearing weight after removal of the cast. During the last several years, the different operative procedures employed for release have gained in precision and efficiency by addressing the deformity at their precise location. The difficult aim of the surgical procedure is to avoid insufficient release causing pseudo-recurrencies or overcorrection.
[Rupture of the degenerated posterior tibial tendon--symptoms and therapy].
The tibialis posterior muscle is a powerful flexor and supinator of the hind foot. Considering the plantar extension of its distal tendon, it represents a true antagonist of the short peroneal muscle. It works as a dash-pot for foot pronation under load. Actually, dorsal extension of the foot happens in the tibiotarsal joint but this movement can be increased partially by the subtalar and midtarsal joint, together with pronation. The latter is damped by the posterior tibialis muscle. Its tendon may rupture suddenly, through e.g. a sports accident; it can also rupture insidiously, through a long degenerative process. The rupture causes a chronic overload of the ligaments about the mid foot and a progressive deviation of the talus in flexion and adduction ensures. This may induce osteoarthrosis, especially of the subtalar joint. Treatment depends upon the stage of the lesion. Reconstruction may be performed by augmentation with the flexor digitorum longus tendon. Palliative treatment by triple arthrodesis may be performed in more advanced cases.
[Hallux valgus and hypermobility of the first ray--causal treatment using tarso-metatarsal reorientation arthrodesis].
Today, bunion surgery is still very controversial. Considering that a bunion deformity is actually a result of multiple possible causes, the rationale of the currently applied techniques has not been conclusively demonstrated. Multiple techniques are still applied with uncertain outcome, as shown by the not insignificant recurrence rate. The tarsometatarsal reorientation arthrodesis addresses the deficient anteromedial buttress which is due to the most often concomittent hypermobile first ray. This is an important aspect of treating hallux valgus deformity and includes the sagittal alignment besides the horizontal reposition of the metatarsal over the sesamoid complex. Since in hallux valgus, the first metatarsal looses its position also by the insufficiency of the intrinsic musculature and the ligamento-capsular structures, the arthrodesis regulates the elasticity of the multiarticular first ray within the sagittal plane. Recurrences are less likely after this operation, even when performed on the adolescent hallux which is known as very difficult to be treated successfully.
[Treatment possibilities of small toe deformities and its indications].
Acquired lesser toe deformities are frequent and can be very troublesome. Often they are combined with other diseases of the foot. When conservative treatment fails, many operative procedures can be offered, which do not always achieve a satisfactory result.
The limited contact dynamic compression plate (LC-DCP).
To realize the new concept of biological internal fixation the limited contact dynamic compression plate was developed. It minimizes vascular damage to the plated bone segment. It should lead to a more versatile and efficient application of internal fixation using plates.
[Peri-acetabular reorientation osteotomy].
A new technique to plan and perform a reorientation pelvic osteotomy around the hip joint in adolescents and adults is described. Planning is based on 3-dimensional reconstruction of the hip joint. The operation is simulated by computer before surgery to find the correction angles which optimize alignment both quantitatively (amount of femoral head covered) as well as qualitatively (joint congruency). These angles are then utilized at the time of surgery. A Smith-Petersen approach is always used to perform the osteotomy. The pelvic ring is not displaced, but nevertheless the acetabular fragment can be tilted without limitation around all 3 axes. Furthermore, linear displacement permits medialization of a lateralized hip joint. Stability is obtained by simple screw fixation. The posterior column remains mechanically intact, and thus no cast is required. Since 1984, about 200 peri-acetabular osteotomies have been performed. The success of correction was evaluated on plain radiographs using A P and "false profile" views as well as by CT. Conventional radiographs showed fully normalized VCE (Wiberg) and VCA (de Sèze and Lequesne) angles and well-centered joints on the CT-based reconstructions. Four types of complications occurred: there were 2 cases with intra articular extension of the osteotomy; 1 transient femoral neuropraxia; 2 non-unions and 4 cases with ectopic ossifications which limited motion of the joint. The latter problem appear to have been eliminated by the administration of prophylactic indomethacin. Symptomatic fixation screws had to be removed after union in 13 cases.