A Single Dose of the Anti-Resorptive Peptide Human Calcitonin Paradoxically Augments Particle- and Endotoxin-Mediated Pro-Inflammatory Cytokine Production In Vitro.

The peptide hormone calcitonin (CT) is known to inhibit bone resorption and has previously been shown also to prevent particle-induced osteolysis, the leading cause of revision arthroplasty. In the present study, the influence of human CT on the initial inflammatory response to particulate wear debris or bacterial endotoxins, ultimately leading to osteoclast-mediated bone resorption, was analysed in human THP-1 macrophage-like cells. The cells were activated with either ultra-high molecular weight polyethylene (UHMWPE) particles or bacterial lipopolysaccharides (LPS) in order to simulate an osteolysis-associated inflammatory response. The cells were simultaneously treated with human CT (10(-9) M). Cytokine production of tumour necrosis factor (TNF)-α was quantified on both RNA and protein levels while interleukins (IL)-1ß and IL-6 were measured as secreted protein only. Stimulation of the cells with either particles or LPS led to a dose- and time-dependent increase of TNF-α mRNA production and protein secretion of TNF-α, IL-1ß, and IL-6. Application of CT mostly enhanced cytokine production as elicited by UHMWPE particles while a pronounced transient inhibitory effect on LPS-induced inflammation became evident at 24 h of incubation. Human CT displayed ambivalent effects on the wear- and LPS-induced production of pro-inflammatory cytokines. Thereby, the peptide primarily upregulated particle-induced inflammation while LPS-induced cytokine secretion was temporarily attenuated in a distinct manner. It needs to be evaluated whether the pro- or anti-inflammatory action of CT contributes to its known anti-resorptive effects. Thus, the therapeutic potential of the peptide in the treatment of either particle- or endotoxin-mediated bone resorption could be determined.

Cervical biomechanics and neck pain of "head-spinning" breakdancers.

The cervical spine of breakdancers is at great risk due to reversed body loading during headspin manoeuvers. This study focused on the cervical biomechanics of breakdancers and a correlation with neck pain. A standardized interview and biomechanical testing of the cervical spine of 25 participants with "headspin" ability ages 16-34 years and an age-matched cohort of 25 participants without any cervical spine problems was conducted. Neck pain history, Neck Disability Index (NDI), cervical range of motion (CROM) and cervical torque were recorded. The "headspin" group reported significantly better subjective fitness, more cervical complaints, higher pain intensity, a longer history of neck pain and a worse NDI compared to the "normal" collective. The "headspin" group showed a 2-2.5 times higher rate of neck pain than the normal population, with increased cervical flexion (p<0.05) and increased cervical torque in all planes (p<0.001). The CROM showed a negative moderate to strong correlation with NDI, pain intensity and history of neck pain. Sports medicine practitioners should be aware of headspin maneuver accidents that pose the risk of fractures, dislocations and spinal cord injuries of breakdancers.

[Stingray injury--a harmless injury for surfers?]. / Der Stachelrochenstich--eine harmlose Wellenreitverletzung?

BACKGROUND: Stingray injuries with potentially lethal outcomes have been described in the medical literature, but a stingray injury to a surfer does not belong to the injuries treated daily in Germany. PATIENTS: We report on a stingray injury to a 31-year-old female with an uncommon course. RESULTS: Diagnostics of and therapy for stingray injuries are described. CONCLUSION: Stingray stings are painful injuries. In addition to the pain-relieving heat deactivation of the stingray toxin, the wound has to be cleaned to avoid secondary infection. Non-radiopaque foreign bodies should be ruled out by MRI. Stingray bites can cause severe injuries to water sportsmen and women with the need for surgical intervention.

Positive modulation of the α9α10 nicotinic cholinergic receptor by ascorbic acid.

BACKGROUND AND PURPOSE: The activation of α9α10 nicotinic cholinergic receptors (nAChRs) present at the synapse between efferent olivocochlear fibres and cochlear hair cells can prevent acoustic trauma. Hence, pharmacological potentiators of these receptors could be useful therapeutically. In this work, we characterize ascorbic acid as a positive modulator of recombinant α9α10 nAChRs. EXPERIMENTAL APPROACH: ACh-evoked responses were analysed under two-electrode voltage-clamp recordings in Xenopus laevis oocytes injected with α9 and α10 cRNAs. KEY RESULTS: Ascorbic acid potentiated ACh responses in X. laevis oocytes expressing α9α10 (but not α4ß2 or α7) nAChRs, in a concentration-dependent manner, with an effective concentration range of 1-30 mM. The compound did not affect the receptor's current-voltage profile nor its apparent affinity for ACh, but it significantly enhanced the maximal evoked currents (percentage of ACh maximal response, 240 ± 20%). This effect was specific for the L form of reduced ascorbic acid. Substitution of the extracellular cysteine residues present in loop C of the ACh binding site did not affect the potentiation. Ascorbic acid turned into a partial agonist of α9α10 nAChRs bearing a point mutation at the pore domain of the channel (TM2 V13'T mutant). A positive allosteric mechanism of action rather than an antioxidant effect of ascorbic acid is proposed. CONCLUSIONS AND IMPLICATIONS: The present work describes one of the few agents that activates or potentiates α9α10 nAChRs and leads to new avenues for designing drugs with potential therapeutic use in inner ear disorders.

[Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics]. / Distale Radiusschaftfraktur beim Cyr Wheel-Turnen - eine ungewöhnliche Rhönradverletzung.

The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate.

[The "wheel gymnast's elbow" - first description of a common overuse syndrome]. / "Der Rhönradellenbogen" - Erstbeschreibung eines häufigen Überlastungssyndroms.

BACKGROUND: Overuse syndromes of the elbow due to wheel gymnastics are unknown in medical literature. This study describes a common overuse syndrome of the elbow in wheel gymnastics. METHODS: We conducted internet research and interviewed 260 wheel gymnasts, who trained the "hip roll" element. RESULTS: 60.4 % of the gymnasts reported changes of the elbow region. The intensity of pain during training was 1.51 out of 10 points. Lacerations were reported in 33.1 %, hematomas were reported in 68.7 %, and a loss of hair at the elbow region was reported in 11.7 %. 11.5 % of the gymnasts described a bump and 5.8 % described a depression of the proximal ulnar region that was not found before wheel gymnastics. Gymnasts using protective gear reported significantly higher levels of pain compared to gymnasts without protective gear. DISCUSSION: The "wheel gymnast's elbow" is a common overuse syndrome of the proximal ulnar due to direct contact and friction of the proximal ulnar to the giant wheel bars. The "wheel gymnast's elbow" describes a combination of lacerations, hematoma, hair loss, bumps, and depression of the proximal ulnar region with only slight pain. CONCLUSION: An early preventive use of protective gear during "hip roll" training can possibly reduce the "wheel gymnast's elbow" syndrome.

[Therapy-resistant, atrophic and septic femoral pseudarthrosis]. / Therapieresistente, Atrophe und Infizierte Femorale Pseudarthrose.

Non-union is a common and serious complication in orthopaedic surgery with high socioeconomic importance. In addition to conventional methods for the treatment of non-unions bone morphogenetic protein (BMP)-7 for the induction of bone tissue is available. The case report demonstrates successful treatment of a septic and atrophic femoral non-union by combination therapy with BMP-7 and autologous spongiosa graft after multiple revision surgeries.

[Breakdancer's "Headspin Hole" - first description of a common overuse syndrome]. / Das "Headspin Hole" bei Breakdancern - medizinische Erstbeschreibung eines häufigen Uberlastungsschadens.

INTRODUCTION: Several typical injuries due to breakdancing have been described in medical literature, but until now the "headspin hole" has not been mentioned. METHODS: We conducted internet research and interviewed 106 breakdancers. RESULTS: 60.4 % of the breakdancers suffered from overuse of the scalp due to the headspin. Loss of hair was found in 31.1 % and painless lumps on the head in 23.6 %. Inflammation of the scalp was reported in 36.8 %. DISCUSSION: The "Headspin Hole" is a common overuse syndrome of the scalp specific to headspins causing hair loss, inflammation and lumps on the skull.

[Arthroscopic refixation of traumatic 1B-lesions of the TFCC--a retrospective study]. / Arthroskopische Refixation von traumatischen 1B-Läsionen des Discus ulnocarpalis--eine retrospektive Studie.

AIM: The aim of the study was to investigate the postoperative outcome of the arthroscopic sutures of traumatic 1B-lesions of triangular fibrocartilage complex (TFCC) tears. METHODS: Thirty-six patients who underwent an arthroscopic repair of traumatic 1B-lesions of the TFCC without a dislocation of the ulnar styloid process were included in this study. The average age of the 18 male and 18 female patients was 43.8 (range: 22-70) years. In 16 cases, we operated the left and in 20 cases the right TFCC. On average, the follow-up examination was performed after 7.9 years (range: 3.2-14.3) years. Patients with revision operations or neurovascular pathology were excluded. The Mayo modified wrist score and the disability of arm, shoulder and hand (DASH) score were used to identify the outcome. RESULTS: The Mayo modified wrist score was preoperatively 49.74+/-20.99 and postoperatively 82.43+/-15.89 (p<0.001). The DASH score was preoperatively 48.68+/-21.47 and postoperatively 24.1+/-19.81 (p<0.001). Only five patients demonstrated an isolated 1B-lesion of the TFCC and showed, likewise, significant improvements both regarding the DASH score and the Mayo modified wrist score (p<0.05). However, there was no significant difference to the patients with further wrist injuries (p>0.05). CONCLUSION: The results of the current study suggest that 1B-lesions of the TFCC can be successfully repaired by arthroscopically assisted suture techniques. An isolated 1B-lesion of the TFCC is rather unusual.

Polyethylene particle-induced bone resorption in substance P-deficient mice.

Aseptic loosening is the major cause of total joint replacement failure. Substance P (SP) is a neurotransmitter richly distributed in sensory nerve fibers, bone, and bone-related tissue. The purpose of this study was to investigate the potential impact of SP on bone metabolism in polyethylene particle-induced osteolysis. We utilized the murine calvarial osteolysis model based on ultrahigh molecular weight polyethylene (UHMWPE) particles in 14 wild-type mice (C57BL/J6) and 14 SP-deficient mice. Group 1 (C57BL/J 6) and group 3 (SP-knockout) received sham surgery, and group 2 (C57BL/J6) and group 4 (SP-knockout) were treated with polyethylene particles. Analytical methods included three-dimensional micro-computed tomographic (micro-CT) analysis and histomorphometry. Bone resorption was measured within the midline suture. The number of osteoclasts was determined by counting the tartrate-resistant acid phosphatase-positive cells. UHMWPE-particle treated SP-deficient mice showed significantly reduced osteolysis compared to wild-type mice, as confirmed by histomorphometry (P < 0.001) and micro-CT (P = 0.035). Osteoclast numbers were significantly reduced in groups 3 and 4 compared to groups 1 and 2 (P < 0.001). Unexpectedly, SP-deficient mice (group 3) showed a significantly increased absolute bone mass compared to wild-type mice (group 1) (P = 0.02). The findings of our murine calvaria model lead to the assumption that SP is a promoter in particle-induced osteolysis. The pathophysiology of aseptic loosening is complex, and neuropeptides are not solely responsible for the progress of implant loosening; however, we conclude that there could be coherence between neurotransmitters and particle-induced osteolysis in patients with aseptic loosening.

[Endosteal reaction in the region surrounding the stem of a cement-free prosthesis. An early radiological sign of imminent fracture of the femoral shaft?]. / Endostale Reaktion im Schaftbereich einer zementfreien Prothese. Ein radiologisches Frühzeichen einer drohenden Femurschaftfraktur?

Periprosthetic fractures are familiar complications after total hip arthroplasty and have often been reported in the literature. The most frequent localization of such fractures is the middle third of the shaft. In the case described here a minor trauma resulted in a periprosthetic fracture with fracture of the femur and of the femoral component of a Lord prosthesis. A radiograph taken prior to trauma showed an endosteal reaction at the level at which the fracture later occurred. This might have been an indication that the stem of the prosthesis was already broken; had this radiological sign been correctly interpreted, it is possible that the fracture could have been avoided.

[Structural femoral head allografts in revision surgery of loosened acetabular cups]. / Strukturelle Femurkopfallografts in der Revisionschirugie von gelockerten Hüftendoprothesenpfannen.

BACKGROUND: Treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). Many methods of acetabular reconstruction have been described. The purpose of this study was to evaluate the midterm results of structural femoral head allografts for acetabular reconstruction. METHODS: Thirty-six patients (33 females and 3 males) with acetabular defects ranging from type 2C to type 3B according to Paprosky's classification were included in the study. In all cases acetabular defects were closed using allografts from femoral heads. In 13 cases an uncemented press-fit cup, in 17 cases a cemented polyethylene socket, and in 6 cases a Burch-Schneider antiprotrusion cage was implanted. The mean follow-up period was 84.2 months (range: 5-147). RESULTS: Four acetabular components failed. All 36 grafts were osseointegrated radiographically and formed a mechanically stable construction. The mean Harris Hip Score at the most recent follow-up was 79.8 points. The distance from the obturator line to the prosthesis head center was 3.73 cm (1.17-5.80 cm) preoperatively and 2.79 cm (0.85-4.8 cm) postoperatively (p<0.05). The distance from the teardrop figure to the prosthesis head center was 3.02 cm (1.0-5.8 cm) preoperatively and 3.25 cm (1.6-4.8 cm) postoperatively (p<0.001). CONCLUSIONS: Closure of acetabular defects of types 2C to 3B according to Paprosky's classification can be satisfactorily accomplished using femoral head allografts. These allografts may facilitate future revision surgery. Femoral heads are readily available due to widespread primary total hip replacement surgery. However, the use of structural femoral head allografts for acetabular reconstruction is cost intensive. Individual patient-related aspects, such as the function of revision arthroplasty, have to be considered when planning revision arthroplasty using femoral head allografts.

Reinforcement of deficient femur with inlay strut grafts in revision hip arthroplasty: a small series.

Failure of the femoral component due to severe loss of femoral bone is an important long-term complication of total hip arthroplasty. We treated four patients with a type IV femoral defect (Paprosky classification) because of aseptic and septic loosening. To enhance bone stock and create a stable prosthetic reconstruction we used femoral allografts as inlay strut grafts alone or combined with onlay strut grafts and impaction grafting. At a mean follow-up of 11 years all four patients presented good or excellent results with Harris Hip Score between 86 and 95 points. Radiologically, no migration of the stems were found and the struts showed signs of incorporation. Inlay strut grafts are a reliable method for bone reconstruction of deficient femoral bone stock in failed total hip replacement.

[A comparison of the antiresorptive effects of bisphosphonates and statins on polyethylene particle-induced osteolysis]. / Ein Vergleich der antiresorptiven Effekte von Bisphosphonaten und Statinen auf Polyethylenpartikel-induzierte Osteolysen.

An ongoing unraveling of the molecular mechanisms in aseptic loosening of hip arthroplasty has opened up novel potential pharmacological interventions. In this study the antiresorptive effects of the bisphosphonate zoledronate and the statin simvastatin on ultra high molecular weighted polyethylene (UHMWPE) particle-induced osteolysis were compared. Two previous studies of our group based on the murine calvarial model of UHWMPE particle-induced osteolysis were pooled to form four study groups. Animals in group I (n=14) underwent sham surgery only. In groups II (n=14), III (n=7) and IV (n=7) UHMWPE particles were implanted on the calvariae. Animals in groups III and IV were additionally treated with zoledronate (single 25 microg/kg s.c. injection) and simvastatin (120 mg/day p.o. for 14 days), respectively. After two weeks, calvaria were processed for undecalcified histomorphometry. Bone resorption was measured using Giemsa staining. Osteoclast numbers were determined using TRAP-staining. UHMWPE particle implantation resulted in a grossly pronounced osteolytic activity with significantly increased values of bone resorption (p < 0.001) and osteoclast numbers (p < 0.001). Additional treatment with zoledronate or simvastatin counteracted the particle-induced effects. A comparison of the two medical treatments revealed no statistically significant differences in bone resorption (p = 0.63) and osteoclast numbers (p = 0.41). A single dose of the bisphosphonate zoledronate decreased UHMWPE particle-induced osteolysis in a murine calvarial model as effectively as a daily treatment with simvastin. Both drug groups may have a preventive and therapeutic role as antiresorptive agents in wear particle-induced bone resorption following total joint replacement.

[Follow-up study after dynamic and static stabilisation of the lumbar spine]. / Follow-up-Studie nach dynamischer und statischer Stabilisierung der lumbalen Wirbelsäule.

INTRODUCTION: The clinical indication for graf's ligamentoplasty and dorsoventral fusion may be described as the "lumbar instability syndrome". A follow-up comparison between Graf's ligamentoplasty and instrumental dorsoventral fusion in a consecutive series of 52 patients was performed. METHODS: 52 patients operated on for low back pain were recalled for a clinical and radiological review (at mean 79 months postoperatively). 26 patients underwent Graf' ligamentoplasty and 26 patients underwent dorsoventral fusion. We evaluated the surgical results and measured an objective outcome using the Oswestry Score, Low Back Outcome Score (LBOS) and Visual Analogue Scale (VAS). For radiological evaluation the Mimura and the Pathria Scores were used. RESULTS: There was no statistically significant difference between the two groups, when measured by the Oswestry Score, LBOS and VAS at the latest follow-up. The difference between the preoperative and actual VAS in each group was statistically significant (p < 0.001). Furthermore, there was no provable preoperative parameter in favour of either one of these therapies. CONCLUSION: Both methods for stabilisation methods of the lumbar spine had a comparable clinical outcome.

Peripeduncular lesion alters expression of c-fos induced in the female rat brain by male mounting.

In order to investigate the role of the peripeduncular nucleus (PP) in the control of lordosis in female rats, activation of neurons after mounts without intromission was investigated by means of FOS immunoreactivity (FOS-IR). Ovariectomized rats were injected with estradiol and progesterone and submitted to approximately 50 mounts by the male. The vaginal area was covered with masking tape to prevent intromission and vaginocervical stimulation. This limited stimulation produced FOS-IR in the ventrolateral division of the ventromedial hypothalamic nucleus (VMHVL), in the lateral periaqueductal grey (LPAG), in the peripeduncular nucleus (PP), and in the posterior intralaminar thalamic nucleus (PIL). No significant differences were found in the anterodorsal or posterodorsal parts of the medial amygdaloid nucleus, in the medial part of the medial preoptic nucleus, in the dorsomedial periaqueductal grey and in the medial division of the posterointermediate part of the bed nucleus of the stria terminalis. The same experiment was performed in rats with unilateral lesion of the PP. Both VMHVL and LPAG activation were significantly reduced in the ipsilateral PP lesion side, leading to the conclusion that those structures are primary targets for the somatic stimuli that trigger lordotic reflexes and which are relayed in the PP. Taking into account what is known about the function of the target structures, it is proposed that afferences relayed in the PP reaching the VMHVL would contribute to control the long range level of sexual receptivity, whereas stimuli reaching the LPAG would serve to control lordotic responses in a moment to moment fashion.