Identifying patients with axial spondyloarthritis in primary care: how useful are items indicative of inflammatory back pain?

Background

The value of clinical items defining inflammatory back pain to identify patients with axial spondyloarthritis (SpA) in primary care is unclear.

Objective

To identify predictive clinical parameters for a diagnosis of axial SpA in patients with chronic back pain presenting in primary care.

Methods

Consecutive patients aged <45 years (n=950) with back pain for >2 months who presented to orthopaedic surgeons (n=143) were randomised based on four key questions for referral to rheumatologists (n=36) for diagnosis.

Results

The rheumatologists saw 322 representative patients (mean age 36 years, 50% female, median duration of back pain 30 months). 113 patients (35%) were diagnosed as axial SpA (62% HLA B27+), 47 (15%) as ankylosing spondylitis (AS) and 66 (21%) as axial non-radiographic SpA (nrSpA). Age at onset ≤35 years, improvement by exercise, improvement with non-steroidal anti-inflammatory drugs, waking up in the second half of the night and alternating buttock pain were identified as most relevant for diagnosing axial SpA by multiple regression analysis. Differences between AS and nrSpA were detected. No single item was predictive, but ≥3 items proved useful for good sensitivity and specificity by receiver operating characteristic modelling.

Conclusion

This study shows that a preselection in primary care of patients with back pain based on a combination of clinical items is useful to facilitate the diagnosis of axial SpA.

The neuropeptide calcitonin gene-related peptide affects allergic airway inflammation by modulating dendritic cell function

BACKGROUND

The neuropeptide calcitonin gene-related peptide (CGRP) is released in the lung by sensory nerves during allergic airway responses. Pulmonary dendritic cells (DC) orchestrating the allergic inflammation could be affected by CGRP.

OBJECTIVE

To determine the immunomodulatory effects of CGRP on DC function and its impact on the induction of allergic airway inflammation.

METHODS

CGRP receptor expression on lung DC was determined by RT-PCR and immunofluorescence staining. The functional consequences of CGRP receptor triggering were evaluated in vitro using bone marrow-derived DC. DC maturation and the induction of ovalbumin (OVA)-specific T cell responses were analysed by flow cytometry. The in vivo relevance of the observed DC modulation was assessed in a DC-transfer model of experimental asthma. Mice were sensitized by an intrapharyngeal transfer of OVA-pulsed DC and challenged with OVA aerosol. The impact of CGRP pretreatment of DC on airway inflammation was characterized by analysing differential cell counts and cytokines in bronchoalveolar lavage fluid (BALF), lung histology and cytokine responses in mediastinal lymph nodes.

RESULTS

RT-PCR, immunofluorescence and cAMP assay demonstrated the expression of functionally active CGRP receptors in lung DC. RT-PCR revealed a transcriptional CGRP receptor down-regulation during airway inflammation. CGRP specifically inhibited the maturation of in vitro generated DC. Maturation was restored by blocking with the specific antagonist CGRP(8-37) . Consequently, CGRP-pretreated DC reduced the activation and proliferation of antigen-specific T cells and induced increased the numbers of T regulatory cells. The transfer of CGRP-pretreated DC diminished allergic airway inflammation in vivo, shown by reduced eosinophil numbers and increased levels of IL-10 in BALF.

CONCLUSIONS AND CLINICAL RELEVANCE

CGRP inhibits DC maturation and allergen-specific T cell responses, which affects the outcome of the allergic airway inflammation in vivo. This suggests an additional mechanism by which nerve-derived mediators interfere with local immune responses. Thus, CGRP as an anti-inflammatory mediator could represent a new therapeutic tool in asthma therapy.

Bronchoconstriction in nonhuman primates: a species comparison

Bronchoconstriction is a characteristic symptom of various chronic obstructive respiratory diseases such as chronic obstructive pulmonary disease and asthma. Precision-cut lung slices (PCLS) are a suitable ex vivo model to study physiological mechanisms of bronchoconstriction in different species. In the present study, we established an ex vivo model of bronchoconstriction in nonhuman primates (NHPs). PCLS prepared from common marmosets, cynomolgus macaques, rhesus macaques, and anubis baboons were stimulated with increasing concentrations of representative bronchoconstrictors: methacholine, histamine, serotonin, leukotriene D₄ (LTD₄), U46619, and endothelin-1. Alterations in the airway caliber were measured and compared with previously published data from rodents, guinea pigs, and humans. Methacholine induced maximal airway constriction, varying between 74 and 88% in all NHP species, whereas serotonin was ineffective. Histamine induced maximal bronchoconstriction of 77 to 90% in rhesus macaques, cynomolgus macaques, and baboons and a lesser constriction of 53% in marmosets. LTD₄ was ineffective in marmosets and rhesus macaques but induced a maximum constriction of 44 to 49% in cynomolgus macaques and baboons. U46619 and endothelin-1 caused airway constriction in all NHP species, with maximum constrictions of 65 to 91% and 70 to 81%, respectively. In conclusion, PCLS from NHPs represent a valuable ex vivo model for studying bronchoconstriction. All NHPs respond to mediators relevant to human airway disorders such as methacholine, histamine, U46619, and endothelin-1 and are insensitive to the rodent mast cell product serotonin. Only PCLS from cynomolgus macaques and baboons, however, responded also to leukotrienes, suggesting that among all compared species, these two NHPs resemble the human airway mechanisms best.

The NKT cell ligand αgalactosylceramide suppresses allergic airway inflammation by induction of a Th1 response

One experimental approach for the treatment of allergic reactions is the stimulation of immunoregulatory NKT cells with the synthetic glycolipid αgalactosylceramide. For a first evaluation of the immunomodulatory potential of αGalCerMPEG a human in vitro allergy model was exploited. Acting as an adjuvant, the glycolipid induced an enhanced Th1-biased allergen-specific immune response of autologous lymphocytes. In a mouse model of allergic airway inflammation, αGalCerMPEG-activated NKT cells promoted a cytokine environment in the spleen, leading to priming of Th1 cells. The shift towards a Th1-dominated allergen-specific immune response thus might mediate the abrogation of allergic airway inflammation and thereby might provide a valid option for therapeutic intervention.

A Study on Oxidized Glassy Carbon sheets for Bipolar Supercapacitor Electrodes

Electrochemical Double Layer Capacitors (EDLC) for high energy and power density applications, based on glassy carbon (GO) electrodes, are being developed in our laboratory. In the context of this project, GC sheets were oxidized and investigated with Small Angle X-ray Scattering (SAXS), Electrochemical Impedance Spectroscopy (EIS) and Nitrogen Gas Adsorption (BET). During oxidation an active film with open pores is built on the surface of the GC. Upon oxidation, the internal volumetric surface area of the active film decreases, whereas the volumetric electrochemical double layer capacitance increases. We show that this effect is correlated with the opening, the growth and the coalescence of the pores.

[Innervation of the airways in asthma bronchiale and chronic obstructive pulmonary disease (COPD)]

Airway nerves have the capacity to control airway functions via neuronal reflexes and through neuromediators and neuropeptides. Neuronal mechanisms are known to play a key role in the initiation and modulation of airway hyperresponsiveness and inflammation. Therefore, the nerve fibres may contribute to airway narrowing in asthma and COPD. In addition to the traditional transmitters such as norepinephrine in postganglionic sympathetic nerve fibres and acetylcholine in parasympathetic nerve fibres, a large number of neuropeptides have been identified to have different pharmacological effects on the muscle tone of the vessels and bronchi, mucus secretion and immune cells. Meanwhile, a broad range of stimuli including capsaicin, bradykinin, hyperosmolar saline, tobacco smoke, allergens, ozone, inflammatory mediators and even cold, dry air have been shown to activate sensory nerve fibres to release neuropeptides such as the tachykinins substance P (SP) and neurokinin A (NKA) to mediate neurogenic inflammation. Different aspects of the neurogenic inflammation have been well studied in animal models of chronic airway inflammation and anticholinergic agents such as ipratropium bromide (Atrovent (®)) and tiotropium bromide (Spiriva (®)) have been proved to be important when used as bronchodilators for the treatment of obstructive airway diseases such as COPD. However, little is known about the role of neurogenic airway inflammation in human diseases. In this review, we address the current knowledge of the airway sensory nerves in human asthma and COPD.

Abstract P6-14-09: Acute-Phase Reactions Following Treatment with Zoledronic Acid or Denosumab: Results from a Randomized, Controlled Phase 3 Study in Patients with Breast Cancer and Bone Metastases

Background: Intravenous (IV) bisphosphonates (BP) are currently used to treat bone metastases and prevent skeletal-related events (SRE) in patients with advanced breast cancer. In a phase 3 study, denosumab, a fully human monoclonal antibody against RANKL, was shown to be superior to zoledronic acid (ZA) in delaying or preventing SREs in patients with breast cancer and bone metastases. This prespecified analysis compares ZA and denosumab for the incidence of acute-phase reactions (flu-like syndrome including pyrexia, chills, flushing, bone pain, arthralgias, and myalgias) during the first 3 days after initial treatment in that study.

Methods: Eligible patients were randomized in a double-blind, double-dummy fashion to receive IV ZA 4 mg (adjusted for creatinine clearance as specified by the Zometa label) or subcutaneous denosumab 120 mg every 4 weeks. Most patients (99%) were women; mean (SD) age was 57 (12) years, and baseline characteristics were balanced between groups. Safety analyses were conducted in patients who received ≥1 dose of denosumab (N=1020) or ZA (N=1013). Patient records were searched for adverse events (AEs) and serious AEs that occurred during the first 3 days after the first administration of study drug, using 37 prespecified MedDRA 12.0 preferred terms potentially indicating acute-phase reactions. Per study protocol, AEs were considered serious if they were fatal, life-threatening, required or prolonged in-patient hospitalization, resulted in a persistent or significant disability, or were considered to present a significant medical hazard.

Results: AEs associated with acute-phase reactions in the first 3 days after treatment occurred in fewer patients in the denosumab group (10.4%) than in the ZA group (27.3%; P&lt;0.0001), and no events were attributed to denosumab. The most common acute-phase reaction AEs included pyrexia (0.9% denosumab, 11.5% ZA), fatigue (2.4% denosumab, 4.0% ZA), bone pain (1.3% denosumab, 3.6% ZA), chills (0.3% denosumab, 3.6% ZA), and arthralgia (1.5% denosumab, 3.2% ZA). No patients (0%) in the denosumab group and 10 patients (1%) in the ZA group reported serious AEs associated with acute-phase reactions during the first 3 days. These events included pyrexia (n=7); bone pain (n=2); and asthenia, back pain, chest pain, chills, headache, and malaise (n=1 each). For 6 of the 10 patients, events of pyrexia, chest pain, chills, and bone pain were resolved within 4 days. Three patients with serious acute-phase reaction AEs discontinued ZA treatment after the first dose. Conclusion: Patients treated with denosumab experienced no serious AEs of acute-phase reaction and significantly fewer overall AEs of acute-phase reaction than patients receiving ZA.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-14-09.

Abstract P1-13-05: The Effect of Treatment with Denosumab or Zoledronic Acid on Health-Related Quality of Life in Patients with Metastatic Breast Cancer

Background: Patients with breast cancer and bone metastases often experience skeletal-related events (SREs) and pain, which may impact health-related quality of life (HRQoL). Denosumab is a fully human monoclonal antibody against RANKL shown to be superior in delaying/preventing SREs and more effective in delaying moderate or severe pain in patients with advanced breast cancer compared with zoledronic acid (ZA). Previously reported results from this study population showed that both denosumab and ZA patients showed improvement or maintenance in HRQoL relative to baseline (BL), and a greater proportion of denosumab-treated patients had a clinically meaningful improvement in HRQoL. We now describe the effect of denosumab and ZA treatment on HRQoL among patients with varying degrees of pain at BL.

Methods: Enrolled patients received subcutaneous (SC) denosumab 120 mg or intravenous (IV) ZA 4 mg every 4 weeks in a double-blind, double-dummy fashion. Pain was evaluated using the Brief Pain Inventory — Short Form (BPI). Patients were divided into 2 subgroups based on the level of pain reported at BL: no/mild pain or moderate/severe pain. Patients completed the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire at BL, day 8, and before each monthly visit to assess overall HRQoL. Higher scores (range 0 to 108) represent better HRQoL. Improvement, maintenance, and worsening of HRQoL were assessed through month 18, when 30% of patients had dropped out due to death, disease progression, or withdrawal of consent. A change of ≥5 points (increase or decrease) in the FACT-G total score was considered a meaningful improvement.

Results: Among patients who reported no/mild pain at baseline, more denosumab-treated patients had a ≥5-point increase in their FACT-G score from month 4 onwards. Over the 18 month period, an average of 4.1% more (range: −0.6% to 9.3%) denosumab-treated patients experienced meaningful improvement in HRQoL than ZA-treated patients. There were also fewer denosumab-treated patients experiencing ≥5-point decrease in HRQoL over 18 months (average of 2.4% fewer [range:-4.4% to 6.3% fewer]). Similar patterns were also noted for patients with moderate/severe pain at baseline. An average of 3.0% more (range:-1.7% to 7.9%) denosumab-treated patients had ≥5-point increase in FACT-G scores compared with ZA-treated patients over 18 months. A lower proportion of denosumab-treated patients (3.5% fewer [range: −1.1% to 11.5% fewer]) than ZA-treated patients had a decrease ≥5-points in their FACT-G score over 18 months.

Conclusion: In patients with breast cancer and bone metastases, a greater proportion treated with denosumab than ZA had a meaningful improvement in HRQoL regardless of their pain level at BL.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-13-05.

Abstract P1-13-01: Comparing the Effects of Denosumab and Zoledronic Acid on Pain Interference with Daily Functioning in a Randomized Phase 3 Trial of Patients with Breast Cancer and Bone Metastases

In a recently completed trial of breast cancer patients with bone metastases, denosumab, a fully human monoclonal anti-RANKL antibody, was superior to zoledronic acid (ZA) in delaying/preventing skeletal-related events. Between-treatment differences in patient-reported pain interference with daily functioning were assessed.

Eligible breast cancer patients received monthly subcutaneous denosumab 120 mg or intravenous ZA 4 mg (double-bind, double-dummy design). Patients completed the Brief Pain Inventory (BPI) to assess pain severity and interference with daily functioning (range 0 [does not interfere]-10 [interferes completely]) at baseline (BL), day 8, and before each monthly visit through end of study. The BPI interference scale generated a total interference score as well as an activity subscale (interference with walking, general activity, and work) and an affective subscale (interference with relations with others, enjoyment of life, and mood). Analyses were conducted on all randomized patients with ≥1 PRO assessment and were performed through week 73, when 30% of patients had dropped out due to death, disease progression, or consent withdrawal. Subgroups included patients with no/mild and moderate/severe worst pain at BL. Analyses included time to improvement (≥2-point decrease) or worsening (≥2-point increase) in pain interference, mean change from baseline, and proportion of patients with improving or worsening pain interference scores. Time to improvement in pain interference with activity (PIWA) tended to occur more quickly with denosumab compared with ZA (N=1124; median: 70 days denosumab v 86 days ZA; P=0.09), and time to worsening PIWA tended to be longer with denosumab compared with ZA (N=1676; median: 394 days denosumab v 310 days ZA; P=0.13). In patients with no/mild pain at BL, denosumab also demonstrated a trend for shorter time to improvement in PIWA (N=388; 93 days denosumab v 120 days ZA; P=0.06) and longer time to worsening PIWA (N=755; 369 days denosumab v 232 days ZA; P=0.12). Overall, a greater proportion of patients on denosumab had improvement in PIWA on study than ZA (Figure). Findings were similar with the total interference score and affective subscale.

Figure Proportion of Patients With Improvement in Pain Interference With Activity (≥2-point decrease from BL)*

Daily functioning (total interference and interference with activity and affect) tended to be less disrupted by pain in patients on denosumab compared with ZA. Decreased pain interference showed a trend to occur more quickly with denosumab. Overall, a greater proportion of denosumab patients reported decreased pain interference than ZA patients.

Pituitary adenylate cyclase-activating peptide receptor 1 mediates anti-inflammatory effects in allergic airway inflammation in mice

BACKGROUND

Bronchial asthma is characterized by airway inflammation and reversible obstruction. Since the gold standard of therapy, a combination of anti-inflammatory corticosteroids and bronchodilatory β(2) agonists, has recently been discussed to be related to an increased mortality, there is a need for novel therapeutic pathways.

OBJECTIVE

A new experimental concept that encompasses the vasoactive intestinal peptide/pituitary adenylate cyclase activating peptide (PACAP) family of receptors by demonstrating the anti-inflammatory effects of the PACAP receptor 1 (PAC1R) in a murine model of allergic asthma is described.

METHODS

PAC1R expression was investigated in lung tissue and isolated dendritic cells (DCs) via real-time PCR. Ovalbumin (OVA)-induced asthma models were used in PAC1R-deficient mice and BALB/c mice treated with PAC1R agonist maxadilan (MAX). Bronchoalveolar lavages have been performed and investigated at the cellular and cytokine levels. Fluorescence staining of a frozen lung section has been performed to detect eosinophil granulocytes in lung tissue. Plasma IgE levels have been quantified via the ELISA technique. Lung function was determined using head-out body plethysmography or whole-body plethysmography.

RESULTS

Increased PAC1R mRNA expression in lung tissue was present under inflammatory conditions. PAC1R expression was detected on DCs. In OVA-induced asthma models, which were applied to PAC1R-deficient mice (PAC1R(-/-)) and to BALB/c mice treated with the specific PAC1R agonist MAX, PAC1R deficiency resulted in inflammatory effects, while agonistic stimulation resulted in anti-inflammatory effects. No effects on lung function were detected both in the gene-depletion and in the pharmacologic studies. In summary, here, we demonstrate that anti-inflammatory effects can be achieved via PAC1R.

CONCLUSION

PAC1R agonists may represent a promising target for an anti-inflammatory therapy in airway diseases such as bronchial asthma.

Local treatment with BPPcysMPEG reduces allergic airway inflammation in sensitized mice

According to the hygiene hypothesis, triggering the immune system with microbial components during childhood balances the inherent Th2 bias. In contrast, specific immunotherapy involves exposure of the patient to the allergen in order to achieve desensitization to subsequent contact. In a human in vitro allergy model the potential of the TLR2/6 agonist BPPcysMPEG to modulate antigen presenting cells and allergen-specific immune responses was evaluated. Specific immunomodulation via co-administration of the allergen and BPPcysMPEG enhanced expression of co-stimulatory molecules on DC and increased secretion of the proinflammatory cytokine TNF-α. Acting as an adjuvant, BPPcysMPEG elevated allergen-specific immune responses in co-culture with autologous lymphocytes. Although administration of BPPcysMPEG alone enhanced expression of co-stimulatory molecules on DC, proliferation of autologous lymphocytes was not induced. Based on this finding, the potential of BPPcysMPEG to reduce allergic airway inflammation by preventive modulation of the innate immune system via TLR2/6 agonization was investigated in mice. Local administration of BPPcysMPEG altered cellular influx and cell composition in BAL fluid. Furthermore, the Th2-associated cytokines IL-4 and IL-5 were diminished. Allergen-specific restimulation of cells from mediastinal lymph nodes and splenocytes suggested an alteration of immune responses. The treatment with BPPcysMPEG induced a Th1-dominated cytokine milieu in mediastinal lymph nodes, while allergen-specific immune responses in splenocytes were diminished. The co-administration of allergen and BPPcysMPEG reduced cytokine secretion upon restimulation in mediastinal lymph nodes and splenocytes. From these data we conclude that BPPcysMPEG was able to influence the immune system with regard to subsequent allergen contact by TLR2/6 agonization.

Natural innate cytokine response to immunomodulators and adjuvants in human precision-cut lung slices

Prediction of lung innate immune responses is critical for developing new drugs. Well-established immune modulators like lipopolysaccharides (LPS) can elicit a wide range of immunological effects. They are involved in acute lung diseases such as infections or chronic airway diseases such as COPD. LPS has a strong adjuvant activity, but its pyrogenicity has precluded therapeutic use. The bacterial lipopeptide MALP-2 and its synthetic derivative BPPcysMPEG are better tolerated. We have compared the effects of LPS and BPPcysMPEG on the innate immune response in human precision-cut lung slices. Cytokine responses were quantified by ELISA, Luminex, and Meso Scale Discovery technology. The initial response to LPS and BPPcysMPEG was marked by coordinated and significant release of the mediators IL-1β, MIP-1β, and IL-10 in viable PCLS. Stimulation of lung tissue with BPPcysMPEG, however, induced a differential response. While LPS upregulated IFN-γ, BPPcysMPEG did not. This traces back to their signaling pathways via TLR4 and TLR2/6. The calculated exposure doses selected for LPS covered ranges occurring in clinical studies with human beings. Correlation of obtained data with data from human BAL fluid after segmental provocation with endotoxin showed highly comparable effects, resulting in a coefficient of correlation >0.9. Furthermore, we were interested in modulating the response to LPS. Using dexamethasone as an immunosuppressive drug for anti-inflammatory therapy, we found a significant reduction of GM-CSF, IL-1β, and IFN-γ. The PCLS-model offers the unique opportunity to test the efficacy and toxicity of biological agents intended for use by inhalation in a complex setting in humans.

A European survey on biobanks: trends and issues

Biobanks have recently gained great significance for research and personalised medicine, being recognised as a crucial infrastructure. At the same time, the widely varied practices in biobanking may also pose a barrier to cross-border research and collaboration by limiting access to samples and data. Nevertheless, the extent of the actual activities and the impact of the level of networking and harmonisation have not been fully assessed. To address these issues and to obtain missing knowledge on the extent of biobanking in Europe, the Institute for Prospective Technological Studies (IPTS) of the European Commission's Joint Research Centre, in collaboration with the European Science and Technology Observatory (ESTO), conducted a survey among European biobanks. In total, 126 biobanks from 23 countries responded to the survey. Most of them are small or medium-sized public collections set up either for population-based or disease-specific research purposes. The survey indicated a limited networking among the infrastructures. The large majority of them are stand-alone collections and only about half indicated to have a policy for cross-border sharing of samples. Yet, scientific collaborations based on the use of each biobank appear to be prominent. Significant variability was found in terms of consent requirements and related procedures as well as for privacy and data protection issues among the biobanks surveyed. To help promote networking of biobanks and thus maximise public health benefits, at least some degree of harmonisation should be achieved.

A toxicological evaluation of inhaled solid lipid nanoparticles used as a potential drug delivery system for the lung

Inhalation is a non-invasive approach for both local and systemic drug delivery. This study aimed to define the therapeutic window for solid lipid nanoparticles (SLNs) as a drug delivery system by inhalation from a toxicological point of view. To estimate the toxic dose of SLNs in vitro, A549 cells and murine precision-cut lung slices (PCLS) were exposed to increasing concentrations of SLNs. The cytotoxic effect of SLNs on A549 cells was evaluated by MTT and NRU assays. Viability of lung tissue was determined with WST assay and by life/dead staining using calcein AM/EthD-1 for confocal microscopy (CLSM) followed by quantitative analysis with IMARIS. Inflammation was assessed by measuring chemokine KC and TNF-alpha levels. The in vivo effects were determined in a 16-day repeated-dose inhalation toxicity study using female BALB/c mice, which were daily exposed to different concentrations of SLN30 aerosols (1-200 microg deposit dose). Local inflammatory effects in the respiratory tract were evaluated by determination of total protein content, LDH, chemokine KC, IL-6, and differential cell counts, performed on days 4, 8, 12, and 16 in bronchoalveolar lavage fluid. Additionally, a histopathological evaluation of toxicologically relevant organs was accomplished. The in vitro and ex vivo dose finding experiments showed toxic effects beginning at concentrations of about 500 microg/ml. Therefore, we used 1-200 microg deposit doses/animal for the in vivo experiments. Even after 16 days of challenge with a 200-microg deposit dose, SLNs induced no significant signs of inflammation. We observed no consistent increase in LDH release, protein levels, or other signs of inflammation such as chemokine KC, IL-6, or neutrophilia. In contrast, the particle control (carbon black) caused inflammatory and cytotoxic effects at corresponding concentrations. These results confirm that repeated inhalation exposure to SLN30 at concentrations lower than a 200-microg deposit dose is safe in a murine inhalation model.

[Two-year results of a modular short hip stem prosthesis--a prospective study]

AIM

The short-term results of a prospective, consecutive series of 50 cementless modular short hip stem endoprostheses are reported.

METHOD

48 cases were available for clinical and radiological follow-up at an average time of 2.4 years post-op. One patient did not consent to a follow-up investigation, 1 early revision was necessary 4 weeks post-op after a fall precipitating a periprosthetic fracture.

RESULTS

The average age at the time of THA was 54 years and the Harris hip score reached 95 points at the time of follow-up. One implant had aseptic loosening and 1 implant was revised due to a failure of the modular titanium neck adapter. An equal number of patients received modular neck adapters with neutral or 7.5 degrees retroversion. No 140 degrees neck and no anteverted neck adapters were used. Radiological results of the 2/3 porous coated hip stem showed a metaphyseal bone remodelling with hypertrophies in coated Gruen zones 3 (17%) and 6 (46%) and marked spot welds and increased bone density (86%) in the distal area of the coating. Primary implant migration between 2 and 10 mm was present in 7 cases due to a low osteotomy and implant position combined with an implant undersizing and lack of proximal-lateral support. At the time of the last follow-up these cases had no clinical symptoms with an average HHS of 96 points and with full bony integration.

CONCLUSION

Our results support the use of the investigated short hip stem for THA when the femoral bone quality and morphology support the metaphyseal anchoring concept. The surgical technique must avoid a stem position without proximal-lateral cortical contact to the femoral osteotomy, as this reduces primary implant stability. Further follow-up is necessary to validate the long-term success of this procedure.