Diaryltriazolium Photoswitch: Reaching a Millisecond Cycloreversion with High Stability and NIR Absorption

The exceptional thermal stability of diarylethene closed isomers enabled many applications but also prevented utilization in photochromic systems that require rapid thermal reversibility. Herein, we report the diaryltriazolium (DAT+ ) photoswitch undergoing thermal cycloreversion within a few milliseconds and absorption of the closed form in the near-infrared region above 900 nm. Click chemistry followed by alkylation offers modular and fast access to the electron-deficient DAT+ scaffold. In addition to excellent fatigue resistance, the introduced charge increases water solubility, rendering this photoswitch an ideal candidate for exploring biological applications.

DiI-CT-A bimodal neural tracer for X-ray and fluorescence imaging

Here, we present an X-ray-visible neural tracer, referred to as DiI-CT, which is based on the well-established lipophilic indocarbocyanine dye DiI, to which we conjugated two iodine atoms. The tracer is visible with microfocus computed tomography (microCT) imaging and shares the excellent fluorescent tracing properties of DiI. We document the discovery potential of DiI-CT by analyzing the vibrissa follicle-sinus complex, a structure where visual access is poor and 3D tissue structure matters and reveal innervation patterns of the intact follicle in unprecedented detail. In the brain, DiI-CT tracing holds promise for verification evaluation of indirect connectivity measures, such as diffusion tensor imaging. We conclude that the bimodal dye DiI-CT opens new avenues for neuroanatomy.

[Operative access for treatment of pilon fractures]

BACKGROUND

Under optimal conditions, fractures of the tibial pilon can be definitively managed operatively within 6 h after the trauma. Under suboptimal conditions, preoperative antiphlogistic treatment, possibly after approximate correction and external fixation of the alignment, is a reasonable option. Osteosynthesis implies reconstruction of good joint congruency in anatomical orientation. The soft tissue coverage of the distal lower leg is relatively poorly constructed and there is a high risk of devascularization, necrosis and ensuing infection.

THERAPY

Several local accesses with complete visual control of the joint surface enable a strain-free soft tissue handling and thus reduction of the incidence of complications. Besides a specific access to the fibula fracture, two anterior and two posterior accesses are proposed based on normal vascularization. These accesses can be simultaneously combined. Using a bone distractor facilitates control of the joint surface.

CONCLUSION

Open reduction and stabilization of pilon fractures enables rapid restoration of joint mobility. After having analyzed the fracture and setting the priorities, the treatment strategy should include a well-thought out selection of possible accesses.

Should one consider primary surgical reconstruction in charcot arthropathy of the feet?

Charcot neuroosteoarthropathy of the feet can induce severe instability and deformity with subsequent plantar ulceration leading to substantial disability or even amputation. Traditionally, nonoperative treatment is regarded as the primary option of treatment while surgery is restricted to treating complications or failure of nonoperative treatment. Failed nonoperative treatment essentially prolongs treatment period. We retrospectively reviewed 22 patients (26 feet) with midfoot (n = 9) or hindfoot (n = 17) neuropathy who underwent primary surgical reconstruction and reorientation arthrodesis due to manifest instability, nonplantigrade foot position, and deformity with overt (n = 8) or what we judged was impending ulceration (n = 9). The minimum followup was 0.5 years (mean, 2.7 years; range 0.5-7 years). All eight ulcers healed without recurrence of ulceration or manifestation of new ulcers during the followup period. We observed complications leading to further surgery in nine patients: five with perioperative hematoma and four with instability. AOFAS scores rose from a preoperative mean of 39 to 70 points (hindfoot cases) and from 51 points to 84 (midfoot cases). Early surgical reconstruction in high-risk patients can provide timely restoration of a plantigrade and stable foot and improved quality of life of the patient at complication rates comparable to those after secondary surgery following failed nonoperative treatment; however we emphasize we had no control group in this small case series for which we could compare nonoperative treatment.

LEVEL OF EVIDENCE

Level IV, therapeutic study (case series). See Guidelines for Authors for a complete description of levels of evidence.

Calcaneus, calcaneal tendon and retrocalcaneal bursa. Historical overview and plea for an accurate terminology

Diseases and injuries of several specific structures in the heel region have been an enduring focus of medicine: The anatomical terminology of many of these structures has not been established until recently. The aim of the study was a historical analysis of the advances of anatomical terminology of three selected morphological units in the heel region--the Achilles tendon, calcaneus and retrocalcaneal bursa. It starts with a critical evaluation of the mythological eposes, the Illiad and Odyssey, describing the exploits of heroes in the Trojan war, followed by a review of relevant terms used for the designation of selected heel structures in the Middle Ages as well as in the 18" and 19" centuries. Principal versions of Latin anatomical terms used for the denotation of the mentioned structures are discussed. Recently applicable Latin terms and their recommended English synonyms, according to the latest version of Terminologia Anatomica (1998) are summed up. It surveys examples of "not very appropriate" terms, which are frequently used in clinical literature. The authors consider the use of official anatomical terms (both Latin and English) as an important step for the improvement of the clinical expressions and formulations.

Die reorientierende subtalare Arthrodese

The subtalar joint is part of what may be called the "lower ankle joint" and can be considered as the weight-bearing part of it. In the case of articular problems such as post-traumatic malunions or congenital abnormalities, a joint fusion limited to the subtalar joint can be indicated. Resection of the joint surfaces for accommodating the bones to achieve sound union results in a loss of height which must be considered and avoided. Fractures of the os calcis also often cause a loss of height of the hindfoot, together with a maloriented heel which is incompatible with functional and stable gait. The technique of fusion in those cases implements full liberation of the calcaneus from the talus for complete tridimensional reorientation which most often results in an equivalent empty space. It is then necessary to stabilize the reorientation achieved, most efficiently by an autologous tricortical bone block taken from the posterior iliac crest at the sacroiliac joint level. The optimal surgical approach is from posterolateral as described by Gallie.

Die posttraumatische Arthrose am Rückfuß

Posttraumatic arthritis of the joint components of the hind foot is typically linked with hind foot deformity and involvement of the neighbouring joint. The principal goals of any hind foot reconstruction are to achieve a quasi-anatomical reconstruction of the geometry and a stable and plantigrade foot position as a prerequisite for acceptable gait function, and an overall satisfactory result for the patient. Profound knowledge of the functions of the ankle-hind foot complex is the basis for the development of a valid therapeutic strategy. Any surgical reconstruction has to consider previous interventions, local soft tissue conditions, neurovascular status, and the components of deformity and degree of arthritic destruction at the corresponding joint levels. In general, an arthrodesis of any hind foot joint, as a key element in hind foot reconstruction, will be successful if correction of the underlying deformity is also adequately addressed.

Swiss adolescents' and adults' perceptions of cannabis use: a qualitative study

Few studies have attempted to investigate the nature of adolescents' and adults' conceptions and perceptions of cannabis use. Our objectives were to explore adolescent and adult perception of use and misuse of cannabis, and their opinions and beliefs about the current legal context and preventive strategies. We used focus group discussions with four categories of stakeholders: younger (12-15 year old) adolescents, older (16-19 year old) adolescents, parents of teenagers and professionals working with young people. In some areas (legal framework, role of the media, importance of early preventive interventions), we found consensual attitudes and beliefs across the four groups of participants. In all four groups, participants did not have any consensual vision of the risks of cannabis use or the definition of misuse. In the area of the prevention of cannabis use/misuse, while parents focused on the potential role of professionals and the media, thus minimizing their own educational and preventive role, professionals stressed the importance of parental control and education. Within the Swiss context, we conclude there exists an urgent need for information and clarification of the issues linked with cannabis use and misuse directed at parents and professionals.

[Talus fractures--fractures of the most important tarsal bone]

The talus is the key bone of the foot due to its location between the ankle and the subtalar joints. Through the flexion and extension of the ankle joint, the talus is the "propulsive bone" situated at the root of the first ray and the hallux. Through the subtalar and talo-navicular joints, the talus allows the foot to be "suspended" using a fancy spring mechanism involving ligaments and tendons. The talus thus transmits forces through two important joints without any direct muscular constraint. The talo-calcaneo-navicular joint may be called the "coxa pedis" due to the anatomical and functional similitudes with the coxofemoral joint ("coxa pelvis"). Fractures of the talus are rare. Talus fractures can be classified in "central" and "peripheral" fractures. Central fractures occur through a strong axial blow provided that the ankle and coxa pedis are locked by extrinsic muscular contraction. Peripheral fractures instead occur in an extreme position of the ankle or the coxa pedis, with a subluxation or complete dislocation of one or more of those joints. Central fractures produce a bony solution of continuity in between at least two of the ankle, subtalar and talo-navicular joints. Peripheral fractures mostly do implement joint surfaces which are sheared off. Aim of treating talus fractures is precise and stable reduction of the fragments because most often, the fractures cross the articular layers. The surgical approaches are critical, especially in displaced central fractures, because the reduction may require visual control all around the bone. There are three approaches which might be used as single approaches or combined simultaneously: the anteromedial approach along the subtalar joint from the navicular to the retro-malleolar region, the anterolateral approach centered on the sinus tarsi (Ollier) and the postero-lateral approach (Gallie). In many cases, a joint distraction device may help visualization of the different joint spaces as well as assist reduction of dislocations. Early joint mobilization, without weight bearing may be very profitable for good functional results. Aseptic necrosis (AVN) of the talus do not need special care if asymptomatic. On the long run, open operative arthrolysis might be added to the eventual removal of implants to considerably improve the results.

Hallux valgus – ein Atavismus?

Als Atavismus versteht man ein rückschlägiges Entwicklungsphenomen, das phenotypisch auftritt. Die Phylogenie lehrt uns heute, dass der erste Strahl in sub-humanen Spezies immer sehr stabil angelegt war. Der prähensile Ur-Fuß erfuhr dann in seinem lateralen Anteil eine progressive Adduktion, Pronation und Extension, zusammen mit einer Valgisation des Kalkaneus mit einer festeren Verankerung an den Talus. Homo sapiens erhielt an der oberen Extremität eine Hand, die sehr beweglich, aber wenig belastbar, an der unteren Extremität hingegen einen Fuß, mit weniger Beweglichkeit aber mehr Belastbarkeit. Trotzdem verblieb am ersten Strahl die Entwicklung einer Bandstruktur, zum zweiten metatarsus aus. Stabilität des ersten Strahls ist somit besonders durch die Muskulatur gewährleistet. Es wurde eine Relation zwischen instabilem, oder hypermobilem erstem Strahl und symptomatischem Hallux valgus gefunden. Zusätzliche Faktoren, die zum schmerzhaften Hallux valgus führen, sind der ägyptische Morphotyp und der funktionelle Spitzfuß. Die Klinik zeigt oft ausgedehnte Vorfußprobleme mit Metatarsus primus varus, Metatarsalgien und Hammerzehen. Die logische Behandlung von der relevanten Hallux valgus Deformität ist die tarso-metatarsale Reorientierungsarthrodese mit oder ohne intermetatarsaler 1–2 Komponente. Osteotomien sind in schweren Fällen unsicherer, besonders langfristig. Atavismus kann man bei der Hallux valgus Deformität verneinen, da die Klinik nicht mit dem archaischen prähensilen Fuß und dessen Entwicklung übereinstimmt. Beim Hallux valgus handelt es sich um eine Deformität an einer schwachen Stelle eines entwicklungsmäßig jungen, hochspezialisierten Organs.

[Medial flexor digitorum longus tendon augmentation and lateral foot column lengthening or reorienting triple arthrodesis as surgical therapy of posterior tibial tendon dysfunction]

QUESTION

The purpose of this study was to evaluate the alignment and functional outcome after surgical augmentation of the tibialis posterior by tendon transfer and lateral column lengthening by osteotomy of the os calcis, calcaneo-cuboidal arthrodesis or reorientating triple arthrodesis.

METHODS

From 1991 to 1999 41 patients with the clinical and radiological diagnosis of dysfunction of the tibialis posterior tendon underwent surgical exploration and repair. These 41 patients (22 women, 19 men) had an average age of 44.3 years (range, 19-69 years) and had been symptomatic for an average of 2.3 years (range, 6 months to 6 years). All patients had the symptoms of a painful flatfoot deformity without dynamic support along the medioplantar aspect. Flexor digitorum longus (FDL) tendon transfer as reconstruction of the tibialis posterior tendon was performed in the cases without major deformity (n = 77). Patients underwent FDL transfer and lengthening osteotomy (n = 15) of the os calcis or calcaneocuboidal (c-c) arthrodesis (n = 12) if passive correction of the foot deformity was still possible and reorientating triple arthrodesis (n = 7) when a fixed flatfoot deformity had developed. AOFAS score and radiological examination were used preoperatively and in the follow-up.

RESULTS

The AOFAS score improved for stage 1 patients after a mean follow-up of 43 months with FDL transfer from a preoperative mean of 54 to 84 points, for stage II patients with FDL transfer and lengthening osteotomy (mean follow-up 36 m) from 47 to 92 points, with c-c arthrodesis (follow-up 66 m) from 48 to 86 points, and for stage III patients with triple arthrodesis from 42 to 72 points. In two patients, the deformity failed to improve (stage I) necessitating a revision surgery with a calceneo-cuboidal lengthening arthrodesis for relapsing deformity.

CONCLUSION

In order to correct deformity and provide substantial relief of foot pain and dysfunction, we recommend the transfer of the FDL tendon in flexible flat foot deformity together with lengthening osteotomy. This treatment will provide optimal restoration of a dynamic support along the medioplantar aspect of the foot and is functionally superior to a c-c arthrodesis. Reorientating triple arthrodesis showed fair functional results and is recommended--for fixed flatfoot deformity.

Development and testing of a new self-locking intramedullary nail system: testing of handling aspects and mechanical properties

A distal interlocking system has been developed which is easy to use, carries out an aligning effect on the distal fracture fragment, reduces the exposure to radiation for the surgeon and the patient, and allows for a decrease in operating time. The goal of this study was to develop and test the handling and mechanical properties of two prototype nails in comparison to a conventional interlocking nail concept (Unreamed Femoral Nail system). It was shown that the prototype designs represent an improvement over this system. Both designs were easy to use. The prototype with the asymmetrically offset interlocking bolts exhibited an exemplary aligning effect on the distal fracture fragment. Both designs showed mechanical stability comparable or superior to that of the standard contralateral control in four-point-bending and axial compression. Given the handling advantages afforded by the new self-locking intramedullary implant system, it would be expected that use of this system would reduce exposure to radiation for the surgeon as well as the patient and allow for a decrease in operating time. This new development may be of particular interest for clinics without access to fluoroscopes in the operating theatre (e.g. in the Third World).

Functional load of plates in fracture fixation in vivo and its correlate in bone healing

In clinical practice efforts are made to apply a fixation plate on the side opposite the strongest muscle pull. This achieves an optimal distribution of compression between the fragment ends (principle of tension band plating). This is however frequently impossible for anatomical or surgical reasons. In an 'in vivo' study lasting 8 weeks a standardized oblique osteotomy was performed on the tibia of 16 sheep in four different models of tension band plating (a contoured and an overbent plate with or without an interfragmentary lag screw) were assessed. Tension on the plate surface was recorded by strain gauges for different gait speeds on the treadmill. These measurements were performed throughout the experiment. Radiographs were taken at regular intervals in order to assess stability and polychrome sequential labelling and microradiographs served to investigate the healing process. Possible relationships and/or interactions between plate tension and bone healing were investigated. Implant loading under bending strain was reduced the most for the combination of plate overbending with a lag screw. The insertion of a lag screw reduces the surface strain on the plate whether it is contoured or overbent. The bending and torsional forces are greatest if a straight plate is used alone and the principle of tension band plating is not applied. Direct bone healing was only observed in the group with contoured plate and lag screw. Overbending combined with a lag screw provided only a relatively unstable fixation. A residual gap immediately beneath the plate permits "dynamic compression" since the screws slide towards the osteotomy when loaded producing bone resorption under the plate and signs of screw loosening. The models with contoured and overbent plates without a lag screw were histologically assessed as very unstable with signs of secondary fragment displacement, obvious callus formation, resorption at the fragment ends and under the plate, delayed and diminished Haversian remodelling and corrosion sites at the screw heads and at the adjacent site on the plate hole. In all groups, stripping of the periosteum under the plate was associated with porosis of the corresponding cortex as a sign of temporarily impaired blood supply. A relationship between implant loading and/or unloading (stress shielding) could not be demonstrated. Callus formation, measured quantitatively on the radiographs, is directly related to the strain on the plate. Direct bone healing is rapid and is seen histologically three weeks postoperatively, particularly for fixations with contoured plate and lag screw. The early appearance of fixation callus in the presence of an intact blood supply indicates a primary instability of the osteosynthesis. Later, it may be an indication of secondary instability. The time at which osteons appear, their number and location provides information on the stability of the osteosynthesis. At a time when indirect fracture reduction and stabilization using minimally invasive techniques and implants is being propagated, additional ways and means must be sought to assess clinically the load on the implants and the risk of implant failure.

Long-term effects of plate osteosynthesis: comparison of four different plates

Various phenomena have been observed subsequent to plate osteosynthesis, for example, refracture after plate removal. Experimental research has shown that changes in the cortex occur within the first three months after plating and again several months later. These changes are independent of the fracture and take the form of porosis under the plate and excessive bone growth around the plate. Porosis under the plate was regarded until recently as being due to unloading of the bone by the plate, also known as stress shielding. Investigations of the relationship between bone porosis and the changes in periosteal blood supply due to its compression by the plate, however, have been neglected. In this study, the effect of plate properties such as structural stiffness ('unloading'), implant material, and plate contact surface (altered periosteal blood supply) on bone after osteosynthesis were investigated. This was done by comparative histomorphometry of the altered bone in sheep after application of four plates differing in the above-mentioned properties. After plating the sheep tibia with a trapezoid plate with narrow contact surface, significantly larger bone cross sections were observed one year after the operation and considerable bone growth around the plate. The area of early temporary porosis in the cortex under the plate as observed in the first nine weeks and after one year was not significantly different for any particular plate, all of which were applied subperiosteally. The trapezoid plates were easier to remove, thus causing less damage to the bone lamellae along the sides of the plate. The marked increase in bone cross section after one year and the larger areas of bone growth around the trapezoid plates with smaller contact surface can be attributed to the larger grooves cut along the sides of the plates. Cortical porosis was mainly the result of impaired periosteal blood supply which was of equal size in all groups as a result of careful periosteal stripping and subperiosteal plate insertion. It was assumed that applying the plate onto the periosteum would be associated with effects on periosteal blood supply directly related to the plate and consequently cortical porosis. Plate related stress shielding and the implant material had no significant effect on the extent of cortical porosis.

Retroversion of the acetabulum

We describe a little-known variety of hip dysplasia, termed ‘acetabular retroversion’, in which the alignment of the mouth of the acetabulum does not face the normal anterolateral direction, but inclines more posterolaterally.

The condition may be part of a complex dysplasia or a single entity. Other than its retroversion, the acetabulum is sited normally on the side wall of the pelvis, and its articular surface is of normal extent and configuration. The retroverted orientation may give rise to problems of impingement between the femoral neck and anterior acetabular edge.

We define the clinical and radiological parameters and discuss pathological changes which may occur in the untreated condition. A technique of management is proposed.

Retroversion of the acetabulum. A cause of hip pain

We describe a little-known variety of hip dysplasia, termed 'acetabular retroversion', in which the alignment of the mouth of the acetabulum does not face the normal anterolateral direction, but inclines more posterolaterally. The condition may be part of a complex dysplasia or a single entity. Other than its retroversion, the acetabulum is sited normally on the side wall of the pelvis, and its articular surface is of normal extent and configuration. The retroverted orientation may give rise to problems of impingement between the femoral neck and anterior acetabular edge. We define the clinical and radiological parameters and discuss pathological changes which may occur in the untreated condition. A technique of management is proposed.

Early full weightbearing and functional treatment after surgical repair of acute achilles tendon rupture

We prospectively evaluated the clinical outcomes of 20 patients (mean age, 42.8 years) with early full weightbearing and functional treatment after surgical repair of acute Achilles tendon rupture according to a prospective intra- and postoperative protocol. All patients underwent open repair using a Kessler-type suture and simple apposition sutures. The postoperative regimen included a plantigrade splint for 24 hours and 6 weeks of early full weightbearing in a removable walker. All patients were evaluated with clinical and ultrasound examination and according to a new scoring system at 3, 6, and 12 months after repair. After 3 months, the score averaged 73 of 100 points; after 6 months, 86; and after 1 year, 94. All patients reached the same level of sports activities as preoperatively and demonstrated no significant difference in ankle mobility and isokinetic strength. There were no reruptures. One patient had a deep venous thrombosis 3 weeks after the operation after having prematurely stopped thromboprophylaxis. We believe that early careful ankle mobilization and full weightbearing in a removable walker after primary Achilles tendon repair does not increase the risk of rerupture. An accelerated rehabilitation program improves early foot function with excellent recovery of plantar flexion strength and amplitude.

[Labrum lesions and acetabular dysplasia in adults]

Thirty-seven operatively treated patients with residual acetabular dysplasia without arthritis had a labrum tear in the antero-lateral quadrant. A sensation of hip locking, or of a "dead leg" and episodes of "giving-way" were found to predict the presence of the tear. 95% of patients had an acute onset of pain. We treated the patients with a peri-acetabular osteotomy and in 12 cases the tear was repaired with a transosseous suture. We excised the labrum lesion in 21 cases with an extended avulsion from the bony rim and 4 tears were not severe enough to require attention. Twenty-two patients were available for a 4.5-year follow-up (range 2-8 years): 18 patients had no pain, 3 had mild pain and one had severe pain. Final pain outcome was not influenced by intraarticular treatment of the tear. The labrum tear is responsible for a well-defined clinical presentation of hip dysplasia and precedes secondary arthrosis. Early diagnosis helps to define the time to perform reconstructive surgery. The treatment consists of improving the coverage and stability of the femoral head by means of a multiplanar peri-acetabular osteotomy. The osteotomy unloads the torn fibrocartilage and allows it to heal by moving it out of the weight-bearing area.

Acetabular rim pathology secondary to congenital hip dysplasia in the adult. A radiographic study

Major rim pathology is a precursor of osteoarthritis of the hip secondary to residual acetabular dysplasia. The symptoms are acute pain in the groin and impaired function; the anatomopathologic lesions consist in avulsions of the labrum from the bony rim, and separated bone fragments or "Os acetabuli", as well. A detailed radiographic, comparative inquiry to assess the preoperative morphology of 178 dysplastic hips which underwent a multiplanar periacetabular osteotomy was undertaken. The study showed that the 37 hips with a labral avulsion had a less pronounced anterior and lateral insufficiency of the acetabulum and a less pronounced lateral subluxation than dysplastic hips without these lesions. No specific radiologic features could be found in the 23 hips with bony fragments of the acetabular rim. The instability of the joint exerts abnormal stress on the acetabular rim which tends to tear it. This condition leads to rapid arthrotic degeneration of the hip; early diagnosis increases our ability to preserve the integrity of the joint through reliable reconstructive surgery.

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.

[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.

[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.

[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.

[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.

[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.

Osteochondral fractures of the glenoid fossa of the ulna in children: review of four cases

Osteochondral fractures of the glenoid fossa of the ulna are exceptional injuries in children. These lesions can present diagnostic problems because the fragments are often radiolucent. We followed four children for 3, 6, and 24 months and 12 years, respectively. The elbow was definitely dislocated in two, and was probably dislocated in two other, children. The most reliable paraclinical examination was conventional sagittal tomography. Open revision is mandatory for reduction of the fracture and, when performed early, may lead to excellent functional results.

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.

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.

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.

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.