J. W.-P. Michael

Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats.

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.

Human Knee Joint Anatomy Revisited: Morphometry in the Light of Sex-Specific Total Knee Arthroplasty

This study investigates differences in the anatomy of male and female knee joints to contribute to the current debate on sex-specific total knee implants. Morphometric data were obtained from 60 human cadaver knees, and sex differences were calculated. All data were corrected for height, and male and female specimens presenting with an identical length of the femur were analyzed as matched pairs. Male linear knee joint dimensions were significantly larger when compared with females. When corrected for differences in height, medial-lateral dimensions of male knees were significantly larger than female; however, matched paired analysis did not prove these differences to be consistent. Although implant design should focus interindividual variations in knee joint anatomy, our data do not support the concept of a female-specific implant design.

Manual stimulation of the orbicularis oculi muscle improves eyelid closure after facial nerve injury in adult rats

We have shown that manual stimulation of rat whisker‐pad muscles following facial–facial‐anastomosis (FFA) restores normal whisking by lowering the proportion of polyinnervated motor endplates. Here we examined whether manual stimulation of the orbicularis oculi muscle (OOM) after FFA would also improve outcome. Blink responses to standardized air puffs were analyzed using video‐based motion analysis. Two months after FFA, blink capacity was impaired, as indicated by a largely increased minimum distance between the eyelids after air‐puff stimulation compared with intact rats (2.7 ± 0.4 vs. 0.2 ± 0.01 mm). Manual stimulation reduced this deficit by a factor of two (1.3 ± 0.5 mm). The functional improvement after manual stimulation was associated with a 2‐fold decrease in the proportion of polyinnervated OOM endplates (21 ± 10% vs. 42 ± 10% without manual stimulation, 0% in intact rats). We conclude that manual stimulation is a noninvasive and simple procedure with immediate potential for clinical rehabilitation of eyelid closure following facial nerve injury. Muscle Nerve, 2008

Treatment delay of bone tumours, compilation of a sociodemographic risk profile: A retrospective study

BackgroundBone tumours are comparatively rare tumours and delays in diagnosis and treatment are common. The purpose of this study was to analyse sociodemographic risk factors for bone tumour patients in order to identify those at risk of prolonged patients delay (time span from first symptoms to consultation), professional delay (from consultation to treatment) or symptom interval (from first symptoms to treatment). Understanding these relationships might enable us to shorten time to diagnosis and therapy.MethodsWe carried out a retrospective analysis of 265 patients with bone tumours documenting sociodemographic factors, patient delay, professional delay and symptom interval. A multivariate explorative Cox model was performed for each delay.ResultsFemale gender was associated with a prolonged patient delay. Age under 30 years and rural living predisposes to a prolonged professional delay and symptom interval.ConclusionEarly diagnosis and prompt treatment are required for successful management of most bone tumour patients. We succeeded in identifying the histology independent risk factors of age under 30 years and rural habitation for treatment delay in bone tumour patients. Knowing about the existence of these risk groups age under 30 years and female gender could help the physician to diagnose bone tumours earlier. The causes for the treatment delays of patients living in a rural area have to be investigated further. If the delay initiates in the lower education of rural general physicians, further training about bone tumours might advance early detection. Hence the outcome of patients with bone tumours could be improved.

Schwann Cells Overexpressing FGF-2 Alone or Combined with Manual Stimulation Do Not Promote Functional Recovery after Facial Nerve Injury

Purpose. To determine whether transplantation of Schwann cells (SCs) overexpressing different isoforms of fibroblast growth factor 2 (FGF-2) combined with manual stimulation (MS) of vibrissal muscles improves recovery after facial nerve transection in adult rat. Procedures. Transected facial nerves were entubulated with collagen alone or collagen plus naïve SCs or transfected SCs. Half of the rats received daily MS. Collateral branching was quantified from motoneuron counts after retrograde labeling from 3 facial nerve branches. Quality assessment of endplate reinnervation was combined with video-based vibrissal function analysis. Results. There was no difference in the extent of collateral axonal branching. The proportion of polyinnervated motor endplates for either naïve SCs or FGF-2 over-expressing SCs was identical. Postoperative MS also failed to improve recovery. Conclusions. Neither FGF-2 isoform changed the extent of collateral branching or polyinnervation of motor endplates; furthermore, this motoneuron response could not be overridden by MS.

Experimental studies on the tensile properties of human umbilical cords

When tried in court, mothers accused of neonaticide may claim that the umbilical cord just broke during birth and the newborn child bled to death accordingly. To evaluate the possibility of a breakage of the umbilical cord is the goal of this work. Therefore 25 umbilical cords from neonates of both sexes born at term were stretched using an electrically operated material testing machine and the energy necessary to break them was measured. This experimental set-up equals a static strain, not a dynamic one. The maximum force endured (F max) ranged from 37.24 N to 150.04 N. The average force endured was 79.87 N with a standard deviation of 27.39. The elongation at break varied from 13.24% to a maximum of 119.93%. We found no relationship between the force endured and any of the following parameters: birth weight, pH of the venous umbilical blood, diameter of cord, free length under testing, duration of pregnancy or the mothers age. We performed a literature research and tried to define the circumstances in which a break is more likely to occur, these being malformations, entanglement or disease, e.g. inflammation.

Relationship between human femorotibial joint configuration and the morphometry of the anterior cruciate ligament.

IntroductionIndividual variations in the anatomy of the knee joint have been suggested to affect the ability to functionally compensate for ACL insufficiency or to put an individual at an increased risk of ACL injury. These variations include the posterior tibial slope, the concavity of the medial tibial plateau, the convexity of the lateral tibial plateau, and the configuration of the femoral condyles.MethodThis anatomical study investigates if there is a correlation between the individual surface geometry of the femorotibial joint and the morphometry of the ACL. These data were assumed to provide evidence whether or not the functional stability of an ACL-insufficient knee may be derived from its radiographic surface geometry. Standardised measurement techniques were used to analyse the surface geometry of 68 human cadaver knees. Data were correlated with the cross-sectional area, the area of insertion and position of the footprint of the ACL and its functional bundles.ResultsAnalysis revealed that there was a significant, but weak correlation between the femoral and tibial area of ACL insertion and the depth of the medial and lateral femoral condyle. No correlation was found between the surface geometry of the femorotibial joint and the cross-sectional area of the ACL. The results of this anatomical study suggest that the relationship between the joint surfaces and the morphometry of the ACL primarily is a function of size of the knee joint.ConclusionsBased on our results, there is no evidence that the stability of the knee can be derived from its radiographic surface geometry.

Classification and treatment of patella fractures

Patella fractures are rare and account for approximately 1% of all fractures. They are classified regarding their localization (proximal, distal) and appearance. The aim of any treatment is reconstruction of the extensor mechanism and joint surface. If dislocation and cartilage steps are less than 2 mm, conservative treatment may be indicated. Operative treatment is only necessary if a dislocation is more than 2 mm or when the extensor mechanism is unstable. Depending on the shape of the fracture, tension band wiring, interfragmentary screw fixation and combinations are the main techniques. Because patellectomy has functionally the worst result it should be avoided. Sleeve fractures (children) need exact reconstruction of the joint surface. In elderly patients conservative treatment or surgical patella-enclosing wiring techniques for stabilization are the best options due to low bone quality.

Einteilung und Therapie der Patellafraktur

Patella fractures are rare and account for approximately 1% of all fractures. They are classified regarding their localization (proximal, distal) and appearance. The aim of any treatment is reconstruction of the extensor mechanism and joint surface. If dislocation and cartilage steps are less than 2 mm, conservative treatment may be indicated. Operative treatment is only necessary if a dislocation is more than 2 mm or when the extensor mechanism is unstable. Depending on the shape of the fracture, tension band wiring, interfragmentary screw fixation and combinations are the main techniques. Because patellectomy has functionally the worst result it should be avoided. Sleeve fractures (children) need exact reconstruction of the joint surface. In elderly patients conservative treatment or surgical patella-enclosing wiring techniques for stabilization are the best options due to low bone quality.

Injuries to the upper limbs in competitive wrestlers

Great variety of tackling and defence in wrestling in standing position and on the floor cannot be compared to other kind of sports. High demand to motoric characteristics and tournament specific movability is required. However wrestling in Germany belongs to a fringe sport there is an increase of professionality. This leads to a sufficient and high-demanded supervision. Aim of this retrospective study was to evaluate sport injuries using a questionnaire and to figure out a correlation between kind and frequency of sport injuries of different body regions. 163 questionnaires out of 200 had been evaluated. In the region of the upper limb injuries had been found in 23%. The injury rate was higher in the athletes wrestling in the 2nd league. Wrestling is a technically and tactically ambitious sport. Injuries should be evaluated very careful to minimize the risk changing tactics and training methods.