Biomedical subjects

B Hintermann

Publications and source records attributed to B Hintermann.

At least 55 records · Page 3Linked to original sources

PubMed1996

The first metatarsal rise sign: a simple, sensitive sign of tibialis posterior tendon dysfunction.

Although foot deformation starts in the early stage of tibialis posterior (TP) tendon dysfunction, this condition is often overlooked or misdiagnosed. We observed consistently a clinical sign of TP tendon dysfunction that, to our knowledge, has not yet been described. Patients were tested while they were standing and fully weight-bearing with both feet. When the shank of the affected foot was taken with one hand and externally rotated, or when the heel of the affected foot was taken with one hand and brought passively into a varus position, the head of the first metatarsal raised in the case of TP dysfunction and remained on the ground in normal TP function. The purpose of this prospective study was to validate this clinical finding by surgical exploration, and to compare its sensitivity with other common clinical signs. Our series included 21 consecutive feet with TP tendon dysfunction (19 patients). The deformity was supple in 12 feet and fixed in 9 feet. Radiographs and magnetic resonance imaging were found to be unreliable in diagnosing dysfunction of the TP tendon. While other clinical signs (too many toes, the single-heel rise, and the double-heel rise) were noted to be negative in 20% to 35%, we found our first metatarsal rise sign to be positive in all cases of TP tendon dysfunction. This simple clinical test enables us to recognize and treat a dysfunction of the TP tendon at an early stage, when the foot is still supple. As the foot deformation progresses, early treatment may be the most effective measure in preventing long-term functional impairment.

Adolescent↗

PubMed1995

Total hip replacement with solid autologous femoral head graft for hip dysplasia.

Acetabuloplasty with solid autologous femoral head graft for the treatment of hip dysplasia is an established method which creates the contained cavity needed to accommodate the artificial cup. In order to evaluate the medium- and long-term results of this method using a cementless hemispheric cup, 34 patients (39 hips) operated on between 1979 and 1986 were clinically and radiologically reviewed. The minimal follow-up was 5 years (average 7.6 years). The Harris hip score increased from 36 points preoperatively to 89 points 1 year postoperatively and to 85.1 at the last follow-up. On roentgenographic evaluation, all grafts had been incorporated and appeared to have tolerated the mechanical loading well. Partial resorption of the graft occurred in 22 of the 39 hips, mainly in the lateral non-loaded zone. Twenty-nine of the 39 acetabular components showed migration, on average 4.2 mm cranially and 1.8 mm medially; 92% occurred during the first 2 years, and thereafter it was not progressive. Smaller cups migrated consistently more than larger cups. A significant correlation was found between cup migration and the degree of bone coverage of the cup, and extensive migration occurred in most cases with cup coverage by the host bone of less than 40%-50% of the weight-bearing surface of the cup. Only one acetabular component was altered significantly, and another appears to have become loose. The use of the normal-sized cups and cementless fixation medially in the primary acetabulum are thought to have contributed to our favorable mid- to long-term results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

In vitro kinematics of the axially loaded ankle complex in response to dorsiflexion and plantarflexion.

The rotational movements of the tibia and calcaneus that occur with dorsiflexion-plantarflexion and axial loading were studied in cadaver foot-leg specimens using an unconstrained testing apparatus. Independent of the foot flexion position, significant internal rotation of the tibia and eversion of the calcaneus were noted after the ankle complex was axially loaded. Independent of loading, 10 degrees of dorsiflexion resulted in 0.1 degrees of eversion and 2.1 degrees of internal rotation of the tibia. Conversely, 10 degrees of plantarflexion resulted in 1.6 degrees of inversion and 1.3 degrees of external rotation of the tibia. The induced rotational movements of the tibia and the calcaneus differed significantly between the specimens. These results suggest that the foot "axes" did not change by axially loading the ankle complex and they support previous reports that the ankle complex uses different axes for dorsiflexion and plantarflexion.

Aged↗

PubMed1995

Influence of ligament transection on tibial and calcaneal rotation with loading and dorsi-plantarflexion.

The purpose of this study was to quantify the effect of sequential ligament transection (anterior talofibular, calcaneofibular, posterior talofibular, deltoid, and subtalar interosseous ligaments) on the rotational movement of the tibia and the calcaneus as associated with axial loading and dorsi-plantarflexing the foot. Eight cadaver foot-leg specimens were investigated using a unconstrained testing apparatus. As the ankle complex was axially loaded, almost the same internal rotation of the tibia and the same calcaneus eversion was found with and without the various degrees of lateral and medial ligament release; additional sectioning of the subtalar interosseous ligament tremendously increased the resulting tibial and calcaneal rotation. While tibial and calcaneal rotation from foot dorsi-plantarflexing did not alter significantly with transection of the lateral ligaments, almost no tibial and calcaneal rotation occurred after additional sectioning of the deltoid and subtalar interosseous ligament. These results indicate that, after release of the lateral ligaments, the foot becomes partially mechanically disconnected from the tibia by additional transection of the medial ligaments and even further disconnected after transection of the subtalar interosseous ligament.

Aged↗

PubMed1995

Influence of arthrodeses on kinematics of the axially loaded ankle complex during dorsiflexion/plantarflexion.

The purpose of this study was to quantify the effect of selective arthrodesis (stabilization) of the ankle, subtalar, and talonavicular joints on the rotational movement of the tibia and the calcaneus occurring with dorsiflexion/plantarflexion. Six cadaver foot-leg specimens were investigated using an unconstrained testing apparatus. Simulated ankle joint arthrodesis caused a large increase in tibial rotation and calcaneal eversion-inversion. Subtalar and talonavicular stabilization did not cause as large a rotation.

Aged↗

PubMed1995

Skier's thumb. Treatment, prevention and recommendations.

Skier's thumb is an injury to the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint (MCPJ) which has a serious risk of disabling chronic instability if not treated adequately. The lesion most often occurs in skiers when the ski pole forces the thumb to deviate radially. Strapless poles do not decrease the incidence of skier's thumb, but if skiers are trained to discard the pole during a fall the risk might be reduced. Clinical and anatomical findings and the understanding of the injury mechanism show that stability testing (performed with the joint in full flexion) and additional standard radiographs remain the keystones in decision making in all MCPJ sprains. Protective splinting is advocated in stable, undisplaced avulsion fractures and incomplete ligamentous lesions of the UCL. However, surgery should not be delayed where there are displaced bony avulsion fractures, and where a complete ligamentous rupture is suspected because of a more than 30 degrees stressed radial deviation and more than 20 degrees difference compared with the uninjured side. Controlled active range of motion exercises can usually be started 3 to 4 weeks after the injury or open surgical repair, respectively. Protective splinting is continued until the sixth week and unrestricted use allowed 12 weeks following injury.

Athletic Injuries↗

PubMed1995

[Biomechanical aspects of muscle-tendon functions].

Moment arms of muscle forces with respect to joints are useful parameters in muscle-function analysis. In general, moments are defined with respect to a (functional) axis, but in the case of a complex motion, as in the case of foot and hand motion, they can be defined with respect to the instantaneous (clinical) rotation axis of this motion. Since in this case the exact rotation axis is not known, the moment arm cannot be determined by measuring the distance between the rotation axis and action line of the muscle. The purpose of this work is to show how the moment arm can be determined with respect to an unknown clinical rotation axis. As is the case for the triceps surae, the moment arm about the rotational axis is not constant thorough the whole range of motion. Muscle function also markedly depends on the insertion pattern of its tendon. The tibialis posterior, for instance, has five major insertions to the medial foot, and its main function is therefore more a stabilizing function than a rotator function of the foot.

Biomechanical Phenomena↗

PubMed1995

[Dysfunction of the posterior tibial muscle due to tendon insufficiency].

The mechanical integrity of the arch of the foot depends on static and dynamic factors. The posterior tibial tendon in particular is situated to provide dynamic support along the medioplantar aspect of the foot and arch. Tibialis posterior dysfunction is a progressive condition leading to a painful flatfoot deformity. To understand changes that occur in the pathological state, a clear analysis of the normal function of the tibialis posterior is necessary. Early diagnosis of posterior tibialis dysfunction is crucial for preventing a progressive deformity. For diagnosis, clinical findings are predominant. When passive correction of the foot deformity is still possible, a reconstruction of the tendon should be attempted. As retraction of the tendon ends or degeneration prevents primary repair, tendon transfer may substitute for the posterior tibial tendon. When a fixed flatfoot has developed, realignment by arthrodesis is advised. Triple arthrodesis may be appropriate to correct hindfoot valgus as well as forefoot abduction.

Adolescent↗

PubMed1994

Theo van Rens Prize. Arthroscopic assessment of the unstable shoulder.

The purpose of this study was to evaluate prospectively the findings during shoulder arthroscopy in patients with recurrent anterior instability of the glenohumeral joint. One hundred and seventy-eight patients who fulfilled the criteria of having had at least one documented shoulder dislocation were included in the study. The pathological findings most frequently noted at arthroscopy were: anterior glenoid labral tears (85%), ventral capsule insufficiency (80%), Hill-Sachs compression fractures (67%), glenohumeral ligament insufficiency (55%), rotator cuff tears (20%), posterior glenoid labral tears (8%), and SLAP lesions (5%). Abnormalities were noted more frequently than expected, and there were significant differences between preoperative and postoperative diagnoses. Our study has taught us that a multiplicity of morphological changes are associated with instability of the glenohumeral joint, and that there is no single cause. The labrum and rim of the anterior inferior glenoid, for instance, showed typical abnormalities corresponding to different entities of anterior instability. In practice, this is very important, as the abnormalities visualized by imaging methods determine the surgical treatment.

Adult↗

PubMed1994

[Movement transfer between foot and calf in vitro].

The mechanical coupling of leg and foot which may be related to the aetiology of knee injuries is still not well understood. The goal of this study was to determine in vitro the movement transfer from calcaneal eversion-inversion to tibial rotation and vice versa occurring in the ankle joint complex. A lower leg holding and loading device with 6 degrees of freedom was used for investigation of 14 fresh-frozen, foot-leg specimens. Movement transfer between calcaneus and tibia was not the same for different input modes and different from calcaneus to tibia compared to movement transfer from tibia to calcaneus. Vertical loading of the tibia and foot flexion position had a major influence on this transfer of movement. The results implicate that excessive pronation, in running for instance, is only critical for high knee loading when coupled with a high movement transfer in the ankle joint complex.

Ankle Joint↗

PubMed1994

Foot movement and tendon excursion: an in vitro study.

The purpose of this study was to determine tendon excursions resulting from selected foot movement and to derive moment arms with respect to the eversion-inversion and flexion-extension axes of the foot. A lower leg-holding device with 6 degrees of freedom was used for the in vitro investigation of 15 fresh foot-leg specimens. Although high variation among the subjects existed, there was a pronounced uniformity of tendon excursion throughout a given foot eversion-inversion or flexion-extension range of motion. With reference to the tibialis posterior (1.00), average invertor moment arms with respect to the foot eversion-inversion axis were found to be as follows: flexor digitorum longus, 0.75; flexor hallucis longus, 0.62; tibialis anterior, 0.59; soleus, 0.24; extensor hallucis longus, 0.22; extensor digitorum longus, -0.26; peroneus longus, -0.82; and peroneus brevis, -0.85. A trend toward decreasing evertor/invertor moment arms was observed during the ranges of foot eversion, as well as when the foot was in flexion. Flexor and extensor moment arms were found to be substantially dependent on foot flexion-extension angle. Increasing flexor moment arms were observed when rotating the foot throughout the range from extension to flexion. The obtained results may have significant implications in foot surgery, muscle function analysis, and general considerations of foot function.

Aged↗

PubMed1993

[Skier's thumb--osseous injury and rupture of the ulnar collateral ligament].

Injuries to the ulnar collateral ligament of the thumb are common in down hill-skiing, and are thus called "skier's thumb". In complete disruption of the ligament, surgical treatment is mandatory to restore stability. The management gets more difficult if a bony lesion is present: does a non-displaced fragment represent a non-displaced bony avulsion of the ulnar collateral ligament, thus allowing conservative treatment? We reviewed sixty-three consecutive patients with an acute skier's thumb injury in order to determine the anatomical nature of injuries in thumbs that were treated surgically either for fracture or for instability. Of all 63 thumbs, twenty-five (40%) had a fracture. Surgical exploration showed two types of fractures: a fragment attached to the ulnar collateral ligament, and a fragment not attached to the ulnar collateral ligament. The first type, corresponding to a true avulsion fracture of the ulnar collateral ligament, was found in eight cases. The same fracture type was seen in other seven cases with an additional isolated fragment not attached to the ligament. Such an isolated fragment was observed in ten other cases where the ulnar collateral ligament was completely disrupted. This type of bone fragmentation cannot be differentiated from a bony avulsion of the ulnar collateral ligament on routine films. Therefore, it is mandatory to stress test the injured thumb even when a bony avulsion fracture with no or minimal displacement is suspected on X-ray. The fracture may not represent a bony avulsion, but a fragmentation of the ulnar volar aspect of the proximal phalanx associated with a complete disruption of the ulnar collateral ligament.

Adolescent↗

PubMed1993

[Overuse damage in modern cross-country skiing].

The skating technique in cross-country skiing has changed the demands on the human body. The purpose of this study was to determine the stress on the locomotor system of young cross-country skiers, and whether overuse injuries result from this sport activity. 51 young cross-country skiers of the Swiss national team were interviewed and examined for problems and overuse injuries of the skeleton. The investigations were repeated yearly during a follow-up time of 3 years. Most of the painful irritations and most overuse injuries were localized in the femoropatellar joint and in the distal Achilles tendon. Orthotics were made in 36 cases (71%). Individual adaptations of training programs, as well as special physical exercises were proposed. The frequency of pain limiting the sport activity was reduced from 62.7% to 21.9% within 3 years. The amount of overuse injuries had also decreased from 66.7% to 32.0%. This may signalize the reversibility of overuse injuries following normalization of loading stress although sport activity continues. In particular, no relation was observed between the frequency of overuse injuries and the new skating technique. However, it was shown that skating and jogging may stress the same structures and thus lead to excessive pronation.

Achilles Tendon↗

PubMed1993

[Pronation from the viewpoint of the transfer of movement between the calcaneus and the tibia].

Excessive foot eversion and abnormal tibial rotation have been associated with knee injuries. Why and whether or not overpronation in athletes leads to overuse injuries at the knee joint, however, is still not understood. It could be that this is related to the mechanical coupling at the ankle joint complex. The purpose of this study was to quantify the movement transferred from calcaneal eversion-inversion into tibial rotation, and vice-versa from tibial rotation into calcaneal eversion-inversion. Fourteen foot-leg specimens were used for investigation. A holding device with six degrees of freedom was constructed which allowed to rotate the calcaneus and to determine the resulting tibial rotation, and vice-versa. The movement transfer between calcaneus and tibia varied substantially, and it was not the same for both input modes. In the case of applied internal tibial rotation no calcaneal eversion was found. Apparently, the movement transfer depends from the individual mechanical coupling at the ankle joint complex. Excessive calcaneal eversion does only result in excessive rotational loading of the knee joint when coupled with a high movement transfer at the ankle joint complex. Finally, the results imply that, during gait, pronation results from ground reaction forces acting on the calcaneus, since internal tibial rotation is not transferred into calcaneal eversion.

Biomechanical Phenomena↗

PubMed1992

[Shoe supports and corrective shoes in performance athletes--a 3-year study in young cross-country skiers].

51 young cross-country skiers, members of the Swiss national team, were interrogated and examined relative to problems of the skeleton. In case of 36 athletes (71%), orthopedic corrections of the foot and leg position were effectuated. The annual controls showed a reduction of pain and decreased impairment of the capacity of sport from 62.7% to 21.9%. The painful inflammations decreased over the same period from 66.7% to 32%. In comparison with other epidemiologic studies without treatment, we can conclude that orthopedic corrections are efficient in the protection of high-performance athletes from overload lesions and probably from definitive lesions.

Adolescent↗

PubMed1992

[Injury pattern of the fibular ligaments. Radiological diagnosis and clinical study].

Injuries to the lateral ligaments of the ankle require accurate diagnosis, especially because most injuries to a single ligament are not treated surgically any more. Various stress devices are in use for objective and standardized assessment of the instability of the ankle joint. In a group of 76 patients with injuries to the lateral ligaments of the ankle, we compared post-traumatic instability by a radiological stress test as done by hand or by using a Telos stress device. In 25 patients treated by surgery an additional intraoperative stress X-ray (talar tilt) was performed. The results of the instability tests done by hand versus those obtained with the Telos stress device correlated poorly (r = 0.786). A similar result was obtained by comparing the Telos stress device views to the intraoperative stress controls done by hand (r = 0.771). Only the pre- and intraoperative measurements by hand were in good correlation (r = 0.958). These results are discussed with reference to a biomechanical model and recommendations for routine diagnosis are proposed.

Adolescent↗

PubMed1990

[Soft tissue infection--osteitis--osteomyelitis].

Statistically the posttraumatic osteitis shows a clear tendency to decrease from 1972-76 in comparison with 1982-86 (AO/ASIF-documentation). The incidence of infection varies considerably according to the different anatomical location of fractures. More recently atypical manifestations became of more importance and ask for differentiated bacteriological examinations. A close postoperative follow-up and exact wound-observations enable an immediate and adequate therapy in case of an infection.

Bacterial Infections↗

PubMed1990

[The radiological functional testing in fibular ligament lesions--a critical analysis and clinical study].

Injuries to the lateral ligaments of the ankle require an accurate diagnosis, especially because most injuries to one ligament are not treated surgically any more. Different stress devices are in use for an objective and standardised assessment of the instability of the ankle joint. In a group of 76 patients with injuries to their lateral ligaments of the ankle we compared posttraumatic instability by radiological stress test as done by hand or by a Telos stress device. In 25 patients treated by surgery an additional intraoperative stress X-ray (talar tilt) was performed. The results of the instability tests done by hand versus those obtained with a Telos stress device showed a poor correlation (r = 0.786). An analogous result was obtained by comparing the Telos device stress views to the intraoperative stress controls done by hand (r = 0.771). Only the pre- and intraoperative measurements by hand showed a good correlation (r = 0.958). The results are discussed with reference to a biomechanical model and recommendations for routine diagnosis are proposed.

Adolescent↗