[Ankle arthrodesis - clinical, radiological and biomechanical aspects with special regard to the adjacent joints]

BACKGROUND

Arthrodesis as well as total arthroplasty are well established but controversially discussed treatment options for end-stage osteoarthritis of the ankle joint. For guidance concerning the significance of both surgical procedures we have correlated our clinical, radiological and biomechanical data with an up-to-date literature review.

MATERIAL AND METHODS

15 patients after arthrodesis because of an isolated end-stage osteoarthritis of the ankle joint were followed clinically and radiologically 4 (1.9-8.8) years after surgery. To evaluate the outcome, different scores (AOFAS, Kellgren and Lawrence) were used. In the second part of the study a dynamic foot model was implemented to simulate a foot strike in vitro utilising a cadaver foot. By controlling 6 extrinsic tendons via steel cables, a hydraulic force application and a moving ground plate, a foot strike was simulated. Intraarticular compression load was measured in the talonavicular and calcaneocuboid joints with pressure-sensitive foils.

RESULTS

The mean AOFAS score for the subcategory pain was 28 ± 12 points. In the subcategory function the patients had a mean score of 38 ± 9 points summing up to a mean total AOFAS score of 66 ± 18 points. Six patients showed radiological evidence of degeneration of the talonavicular joint. For these patients the Kellgren and Lawrence score was 2.3 (1-4) points higher than for the opposite side. Concerning the subtalar joint in 6 patients the Kellgren and Lawrence score was 1.6 (1-3) points higher compared to the non-surgery side. In contrast we noted only one case with degeneration of the calcaneocuboid joint. The native trial utilising the foot model revealed a continuous rise of load transmission in both parts of the Chopart joint. After performing an arthrodesis, load transmission rose significantly in the second half of the foot strike concerning the talonavicular joint whereas the calcaneocuboid joint showed a decreased transmission of load.

CONCLUSION

Referring to published data complication rates after ankle arthrodesis are lower compared to total ankle arthroplasty whilst adjacent joint degeneration of the subtalar and talonavicular joints is more common.

[Osteochondrosis dissecans and osteochondral lesions of the talus: clinical and biochemical aspects]

BACKGROUND

The natural course of osteochondral lesions of the talus are varied and the disease pattern is not clearly defined. There is an ongoing discussion among clinicians concerning the aethiopathology and the correct treatment.

METHODS

In this article all relevant studies are analysed with regard to aetiology, long-term outcome and the different established treatment options. Against the background of the current biomechanical understanding, an approach is made to this controversially discussed disease pattern utilising our own biomechanical laboratory results.

RESULTS

The available literature deals with longitudinal analyses regarding the natural history of the disease, conservative treatment, surgical options like debridement and anterograde drilling, retrograde drilling, osteochondral transplantation and autologous chondrocyte transplantation (ACT). Biomechanical trials describe high loads in the anterolateral parts of the joint. In most of the published studies the average age of the patients is around 28 years, younger patients have more favourable outcomes compared to older ones. In children the highest rate of spontaneous and advantageous course of the disease can be expected. Around 75% of the published outcomes relating to surgical therapy are satisfactory while 10% of the patients will suffer from osteoarthritis in the long term.

CONCLUSION

While the aetiopathology of the disease remains unclear, histopathological studies reveal subcortical bone necrosis. In 90% of the cases there is an ankle sprain in the past medical history although a direct correlation with trauma as exclusive trigger is not obvious. A possible approach is an osteochondral fracture in combination with an already existing osteonecrosis. A staged treatment regime is advised. In asymptomatic cases conservative treatment is advocated independent of the stage. Symptomatic patients with Hepple stages I, II and V and intact cartilage surface should undergo retrograde drilling in combination with a subchondral filling with cancelleous bone. If a cartilage defect is present (Hepple stages III, IV, V), an osteochondral transplantation is reasonable. Only if the defect zone is >2.5 cm2 should a debridement combined with a transplantation of cancellous bone and an ACT be considered. The sole anterograde drilling in our opinion should only be performed as an exception.

[Loading of the tibiotalar joint and Chopart's joint following subtalar arthrodesis: dynamic cadaver study of 5 specimens]

AIM

Little has been known until now about biomechanical intra-articular changes in the condition of adjacent joints following subtalar arthrodeses.

METHOD

We tested 5 cadaver specimens in a dynamic axially loaded foot model under computer-regulated load application on 9 extrinsic tendons of the foot regarding changes in load under native conditions and following an anatomically fixed subtalar arthrodesis.

RESULTS

We saw an averaged native force transmission in the talonavicular joint of 87 N, increasing post-arthrodesis to 92 N. In the calcaneocuboid joint we measured an increase from 72 N to 74 N. For peak pressure, the increase was from native 3152 kPa to 3286 kPa in the talonavicular joint and in the calcaneocuboid joint we recorded a reduction from 3282 kPa to 3277 kPa. The effects are not striking from a statistical viewpoint. However, we observed a reduction in force from native 103 N to 90 N and in peak pressure from 4778 kPa to 4261 kPa in the ankle. When the ankle was divided into discrete zones in the sagittal and frontal planes there was no evidence of load displacement.

CONCLUSION

Our measurements show that anatomically fixed arthrodeses of the talocalcanear joint do not lead to any striking increase in loads on adjacent joints. Any adjacent segment degeneration following subtalar arthrodeses may be the result of changes in joint kinematics or non-anatomically reconstructed hindfoot positions.

Chopart's joint load during gait. In vitro study of 10 cadaver specimen in a dynamic model

BACKGROUND

Chopart's joint is fundamental to foot function. Until today, intra-articular force and peak pressure has not been investigated under dynamic conditions.

METHODS

The study used a cadaver model to measure intra-articular force and peak pressure with electronic sensors. Force was applied to extrinsic tendons via cables attached to computer-regulated hydraulic cylinders. A ground reaction force of 350 N was simulated in a tilting angle- and force-controlled translation stage.

RESULTS

We observed a characteristic rising curve with a peak during push-off for intra-articular force and peak pressure. The increase of intra-articular force at the talonavicular and calcaneocuboid joint from a low level at heel-on varies up to a maximum of 174 N/149 N and a peak pressure of 3877 kPa/3396 kPa, respectively, at push-off. We observed highest loading at the dorsal aspect of the talonavicular joint and the plantar aspect of calcaneocuboid joint.

CONCLUSION

The highest loading on Chopart's joint is attained during push-off. We observe higher force and peak pressure on the medial column of the foot compared to the lateral column. The higher load of the dorsal aspect of talonavicular joint and plantar aspect of calcaneocuboid joint confirms the theory of a previous described locking mechanism for forceful push-off.

[Minimally invasive fixed-angle plate osteosynthesis for complex humeral fracture]

Two cases of complex humeral fractures are presented that were stabilised by a minimally invasive approach using a long fixed-angle humerus plate. Postoperative treatment and bone healing were uneventful. Followed by careful preparation of a proximal deltoid split access and a subtle dissection of the m. brachialis the plate can be placed epiperiosteally and the screws can be applied using the"moving window" principle. Fixed-angle fixation with the internal fixator principle allows treating the radial nerve in the direct neighbourhood of the plate with circumspect without full contact between the bone and the plate. The technique can be recommended for complex combined meta- and diaphyseal fractures of the upper two-thirds of the humerus.

Changes in Chopart joint load following tibiotalar arthrodesis: in vitro analysis of 8 cadaver specimens in a dynamic model

Background

In the current discussion of surgical treatment of arthroses in the ankle joint, arthrodesis is in competition with artificial joint replacement. Up until now, no valid biomechanical findings have existed on the changes in intraarticular loads following arthrodesis. One argument against tibiotalar arthrodesis is the frequently associated, long-term degeneration of the talonavicular joint, which can be attributed to changes in biomechanical stresses.

Methods

We used a dynamic model to determine the changes in intraarticular forces and peak-pressure in the talonavicular joint and in the calcaneocuboid joint on 8 cadaver feet under stress in a simulated stance phase following tibiotalar arthrodesis.

Results

The change seen after arthrodesis was a tendency of relocation of average force and maximum pressure from the lateral onto the medial column of the foot. The average force increased from native 92 N to 100 N upon arthrodesis in the talonavicular joint and decreased in the calcaneocuboid joint from 54 N to 48 N. The peak pressure increased from native 3.9 MPa to 4.4 MPa in the talonavicular joint and in the calcaneocuboid joint from 3.3 MPa to 3.4 MPa. The increase of force and peak pressure on the talonavicular joint and decrease of force on the calcaneocuboid joint is statistically significant.

Conclusion

The increase in imparted force and peak pressure on the medial column of the foot following tibiotalar arthrodesis, as was demonstrated in a dynamic model, biomechanically explains the clinically observed phenomenon of cartilage degeneration on the medial dorsum of the foot in the long term. As a clinical conclusion from the measurements, it would be desirable to reduce the force imparted on the medial column with displacement onto the lateral forefoot, say by suitable shoe adjustment, in order to achieve a more favourable long-term clinical result.

Biomechanische Evaluation des Gleitnagels in der Versorgung pertrochantärer Frakturen

AIM

The purpose of the present study is to evaluate wether the gliding nail with it's double-t-shaped geometry is appropriate in the stabilization of unstable trochanteric fractures or not and if this evaluation can be performed with a static finite element simulation.

METHODS

Surface-Reconstruction with CT database of a proximal femur and reconstruction with CT based density data was done. After modelling of geometry, isotropic material behaviour and load application during one leg standing in slow walking was done with a limited dataset of relevant muscles. Two relevant fractures are modelled.

RESULTS

FE-simulation shows a movement of the femoral head distally, medially and posteriorly. Maximum bending strain is in the femoral diaphysis medial compression and lateral tension strain. In the proximal part we find a nearly homogeneous strain distribution. The clinical effect of lateralization of the proximal main fragment is also result of the simulation. In the area of the modelled fractures there is much more compressive stress than shear stress.

CONCLUSION

Elastomechanical behaviour of the gliding nail is demonstrated with correlation of clinical observed effects. In both simulated fracture areas there is a bone union supporting compressive stress. This means in the FE-simulation the gliding nail is appropriate in the stabilization in unstable trochanteric fractures.

Die rotationsstabile intramedulläre Osteosynthese von proximalen extraartikulären Femurfrakturen

AIM

The proximal femur nail (PFN) and the gliding nail (GLN) are two modern procedures available for intramedullary osteosynthesis of proximal extra-articular femur fractures; they allow a rotationally stable fixation of the proximal fragment. In a comparative analysis of complications, both methods should be evaluated.

METHODS

A comparative analysis of both procedures is presented in a prospective clinical study design. The treatment of 240 consecutive patients (124 PFN/116 GLN) with an average follow-up term of 10.2 months is analysed.

RESULTS

Both PFN and GLN give rise to head perforations (4.8% and 2.6%), dislocations of material (0.8% and 0%), intraoperative femoral shaft fractures (0.8% and 2.6%), pseudarthrosis (0% and 0.9%) and fractures of material (0.8% and 0%) in the way of complications as well as wound-healing impairments (9.7 % and 5.2 %) and iatrogenic complications such as false placement of the osteosynthesis material and errors in reposition (0.8% and 4.3%).

CONCLUSION

The gliding nail osteosynthesis yields a more favourable complication profile with regard to specific osteosynthesis-caused complications (6.0%) and wound-healing impairments (5.2%) in comparison with the PFN osteosynthesis (7.3% and 9.7%, respectively). Especially the cut-out rate of the GLN (2.6%) is lower than that of the PFN (4.8%).

Der Golfsport mit Hüft- und Knietotalendoprothesen

Playing golf after THR and TKR is discussed controversially by orthopedic surgeons and Data of 16 patients receiving 22 THR (18 m/4f, 12 r/10 l) and of 11 patients receiving 12 TKR (9 m/3f, 6 r/6 l) were analysed using a questionnaire. The mean age of THR-/TKR-sportsmen was 65,7 (58 - 78)/67,8 (61-76) years. In THR-/TKR-patients surgery was done 59 (12-226)/39 (12-105) month ago. The best handicap (hcp) in their carrier/one year before/one year after surgery was in THR 15,7 (2-36)/18,5 (6-36)/17,7 (4-36), in TKR 18,4 (6-24)/22,1 (8-34)/20,3 (8-28). 11/7 sportsmen with THR/TKR could preserve the level of hcp following surgery, in 7/0 hcp became worse and in 4/5 hcp was even better. Patients with 21 THR and 12 TKR had less pain while playing golf in the operated joint one year after compared to one year before surgery, 1 patient with THR suffered more pain. During follow-up 13 THR/10 TKR reported of no problems playing golf, 7 THR/2 TKR had moderate pain, 2 THR/0 TKR had severe pain, no patients was unable playing golf following the joint replacement. Golf can be recommended as sporting activity after successful THR and TKR.

Arthrodese des MTP-I-Gelenks

Arthrodesis of the first metatarsophalangeal joint is a useful technique for the surgical treatment of hallux rigidus, complicated hallux valgus and rheumatoid forefoot deformity, and for revisions following resection arthroplasty or explantation of a prosthesis combined with interposition of a tricortical bone graft. In primary operations, good or excellent results can be achieved in 80-90% of patients. The articular surface and any exostoses or osteophytes are first resected aiming for a 15-30 degrees extension of the metatarsophalangeal angle and a 5-15 degrees valgus angle. Pseudarthroses occur in 10-13% of arthrodeses stabilized with screws or k-wires. When using a plate for fixation, the rate of pseudarthroses is below 6%. Only a small number of pseudarthroses require revision surgery. Up to 15% of patients develop mostly asymptomatic degeneration of the interphalangeal joint of the hallux.

[Metatarsal osteotomies for hallux valgus]

In the surgical treatment of hallux valgus, proximal, diaphyseal, and distal osteotomies of the first metatarsal bone are commonly used. In an overview article different procedures are described as well as our own stage-adapted concept. Deformities with congruent articulation of the metatarsophalangeal joint are successfully treated with a distal chevron osteotomy. In an incongruent joint a distal soft tissue procedure is required for reduction of the joint. The metatarsus varus displacement is corrected with a proximal osteotomy of the first metatarsal bone. The indications and details of the surgical techniques are described as well as postoperative treatment, results, and possible complications.

[Complication rate in the treatment of inter- and subtrochanteric femur fractures with two intramedullary osteosyntheses. Comparison of a conventional nailing system and a rotation stable fixation of the head-neck-fragment, gammanail and glidingnail]

Aim of the study was to evaluate typical complications in osteosynthesis of inter- and subtrochanteric femur fractures with intramedullary nailing systems. In the literature screw perforation of the femoral head into the acetabulum, postoperative fracture of the femur shaft, intraoperative shaft fracture, problems in placing of distal locking screws and deep infections are mostly described. In a retrospective study the complication rate of 100 consecutive gammanail osteosyntheses (GAN) and 96 glidingnail osteosyntheses (GLN) was analysed. 93 % of GAN and 89.3 % of GLN were followed up. Cutting out rate of GAN/GLN was 7.0 %/3.1 %, postoperative shaft fractures occurred in 1.0 %/0 %, intraoperative shaft fractures in 1.0 %/2.1 %, problems with distal locking in 2.0 %/1.0 % and deep infections in 3.0 %/1.0 %. In an analysis of internationally published data on 2 241 GAN and 365 GLN the cut-out rate was 2.3 %/0.5 %, postoperative shaft fracture 2.2 %/1.4 %, intraoperative shaft fracture 1.2 %/0.3 % and deep infection 1.2 %/2.2 %. GLN shows lower complication rates with regard to femoral head perforation and late shaft fracture than GAN.

[Sports medicine analysis of golf "swing" and lesions occurring during golf practice]

Health problems as seen in golf from the viewpoint of sports medicine and orthopedics are described. For better understanding important phases of the swing are analysed in correlation with possible lesions. Golfers mostly suffer from lumbal spine, elbows, hands and wrists, as well as from shoulder and knee disorders. We must differentiate between problems of the acute injuries and chronic disorders, whereas degenerative problems may interfere with specific golfing movements and are thus aggravated. The most likely causes of muscle joint and bone disorders are overuse, inadequately trained muscles and poor technique.

Different prevalence of asymptomatic atherosclerotic lesions in males and females

The detection of atherosclerotic lesions in asymptomatic healthy subjects is possible using ultrasound. Populations can be investigated in order to detect differences in early and asymptomatic atherosclerosis due to gender and risk factors. This study investigated 2605 male (21-69 years) and 1601 female (20-70 years) employees and civil servants of the city of Düsseldorf, Germany. The ultrasound investigations were performed with an ATL device, type Ultramark 4 plus, and a 7.5-MHz linear transducer on the carotid and proximal femoral arteries. An atherosclerotic lesion was defined as visibly different from the intima by its echogenicity and by being larger than 1 mm. A thickening of the intima media complex was not considered to be atherosclerosis. The prevalence of atherosclerotic lesions in male subjects was higher than those in female subjects regardless of age. In male subjects it was 5.3% (30-39 years), 19.8% (40-49 years), 36.7% (50-59 years) and 47.7% (60-70 years). The female subjects had a prevalence of 2.1%, 8.4%, 17.5% and 37.7% in the corresponding age groups. Risk factors such as smoking, hypertension and hypercholesterolemia were higher in men than in women. The increase of atherosclerotic lesions from one decade to another was highest in women between 50 and 59 years and 60 and 70 years. This large increase could not be explained by a similar increase in risk factors. It was therefore concluded that male subjects had a higher prevalence of atherosclerosis at earlier ages than females, but female subjects showed a postmenopausal rise in prevalence.