Biomedical subjects

B Hintermann

Publications and source records attributed to B Hintermann.

54 records · Page 3Linked to original sources

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↗

PubMed1990

[The treatment of fibular ligament lesions using the Ortho-Rehab shoe].

In a prospective study we examined 46 patients (14-49 years of age) with fresh ruptures of the lateral ligaments of the ankle (talar tilt greater than or equal to 10 degrees). Treatment consisted in six weeks of taping combined with wearing of a special rehabilitation shoe (Ortho Rehab). 28 patients were treated conservatively and 18 had an operative repair of their ruptured ligaments. After 8 weeks every patient was clinically controlled. Until now 35 patients were reevaluated more than one year after injury. Treatment was judged as very comfortable and positive. Working capacity was achieved after an average of 14.8 days and all patients returned to their former sports activity 3 to 8 weeks after the event. Mechanical and functional stability after more than one year are excellent with the exception of 3 cases. The results are discussed and compared with other studies.

Adolescent↗

PubMedDate not supplied

Preoperative arthroscopic assessment of fractures about the shoulder.

Soft tissue lesions in fractures about the shoulder are not completely defined by conventional imaging procedures. The purpose of the present study was to arthroscopically determine the soft-tissue pathology of the labrum, capsuloligamentous, and rotator cuff structures associated with fractures of the proximal humerus and/or scapula and to correlate them to the fracture type. In a series of 80 fractures (52 proximal humeral fractures, 20 fracture-dislocations, 8 glenoid or scapular fractures) arthroscopy was performed through a posterior approach under general anesthesia. Arthroscopy revealed significant numbers of labral, capsuloligamentous, and rotator cuff lesions, as well as cartilage damage not identified by clinical examination or preoperative imaging. Fracture dislocations (Neer type VI) and more benign fractures of the two-part variety are frequently associated with labral lesions (in 56% and 31%, respectively). This data suggest that it is important not to underestimate soft-tissue pathology in fractures that seem radiologically relatively harmless. Arthroscopic assessment in shoulder fractures is shown to be a useful tool in completely understanding the extent of the injury.

Arthroscopy↗

PubMedDate not supplied

[Sub-Achilles bursitis--a biomechanical analysis and clinical study].

Chronic inflammations of the distal Achilles tendon correspond frequently to a mechanical irritation of the subcalcaneal bursa. On grounds of the biomechanical analysis an excessive inward bending of the hindfoot is postulated as the reason. So a conception for the clinical therapy is detected. The first measure will be a statics correction of the foot and a local application of antalgics. In case of unsuccessfulness after 3 months the surgical resection of the calcaneus exostosis is performed. After 3 months of conservative treatment 15 of 24 athletic patients are free of pain. The other 9 patients are free of pain 3 months after the surgical treatment. In either case all patients return to their former sports activity 6 months after the beginning of the treatment.

Achilles Tendon↗

PubMedDate not supplied

Skier's thumb--the significance of bony injuries.

In a retrospective study to determine the anatomic nature of injuries in thumbs that were treated surgically for either fracture or instability, we reviewed 63 consecutive patients with acute skier's thumb injury. Of the 63 thumbs, 25 (40%) had a fracture. Surgical exploration showed 2 fracture types: a fragment that was attached to the ulnar collateral ligament, and a fragment that was not attached to the ulnar collateral ligament. The 1st type, corresponding to true avulsion fracture of the ulnar collaternal ligament, was found in 8 cases; the same fracture type was seen in another 7 cases, with an isolated fragment that was not attached to the ligament. Such an isolated fragment was observed in 10 other cases in which the ulnar collateral ligament was completely disrupted. This type of bony fragmentation cannot be differentiated from a bony avulsion of the ulnar collateral ligament on routine films. Therefore, stress testing the injured thumb is mandatory even when bony avulsion fracture with minimal displacement is suspected from a radiograph, as indeed the fracture may not be a bony avulsion but may be a fragmentation of the ulnar volar aspect of the proximal phalanx associated with a complete disruption of the ulnar collateral ligament.

Bone and Bones↗

PubMedDate not supplied

Arthroscopic findings after shoulder dislocation.

The purpose of this study was to evaluate prospectively the arthroscopic findings of the unstable shoulder, to provide insights into the causes and mechanisms of shoulder instability, and to establish a rationale for using special surgical procedures. Arthroscopic examination was performed on 212 patients who had at least 1 documented shoulder dislocation. Of these 212 patients, 184 (87%) patients had anterior glenoid labral tears, 168 (79%) patients had ventral capsule insufficiency, 144 (68%) patients had Hill-Sachs compression fractures, 116 (55%) patients had glenohumeral ligament insufficiency, 30 (14%) patients had complete rotator cuff tendon tears, 26 (12%) patients had posterior glenoid labral tears, 14 (7%) patients had superior labrum anterior and inferior lesions. As this prospective study shows, multiple morphologic changes are associated with instability of the glenohumeral joint; there is no single cause for an unstable shoulder. Arthroscopic examination of the shoulder before surgery revealed a significant amount of information that would have been undetected without the aid of expensive diagnostic tools. For instance, the labrum and rim of the anteroinferior glenoid showed typical abnormalities corresponding to different entities of anterior instability.

Adult↗