High prevalence of missed information related on bone health in orthogeriatric patients with fragility fractures of the pelvis-an institutional register-based analysis.

This is the first study that highlighted the amount of missed information related on bone health in orthogeriatric patients suffering fragility fractures of the pelvis and also evaluated its prevalence and differing etiology in the assessed patients, regarding osteoporosis and/or osteomalacia, based on laboratory and instrumental measurements. This evaluation should become a standardized procedure in the treatment of orthogeriatric patients presenting with a FFP. INTRODUCTION: Fragility fractures of the pelvis (FFP) are common in orthogeriatric patients. Secondary fracture prevention regarding evaluation and treatment of an underlying osteoporosis or osteomalacia is still often neglected. The purpose of this study was to evaluate the amount of missed information related on bone health in older adult FFP patients, the prevalence of vitamin D deficiency in assessed patients, and if fracture type-dependent distribution patterns could be observed. METHODS: A retrospective analysis of prospectively collected data of an institutional register was performed. Patients aged 80 years and older (n = 456) admitted with a FFP from 01/2003 until 12/2019 to a level I trauma center were included. RESULTS: In 456 patients, FFP type II were leading (66.7%). Diagnostics were conducted in 37.1% of the patients regarding measurement of vitamin D levels and 21.7% regarding DXA measurements; vitamin D deficiency was observed in 62.7%, indicators for an underlying osteomalacia in 45.8%, and an osteoporosis in 46.5% of the assessed patients. CONCLUSION: Although FFP are common and will increase, there is still a lack of secondary fracture prevention, starting with information related on bone health. In the assessed patients, a high prevalence of vitamin D deficiency was present, but no significant correlation between vitamin D level and type of fracture was observed. Ongoing education for varying etiology and specific treatment of these fractures is necessary, as surgical treatment was unified, but drug therapy remains different.

[Treatment of patients with fragility fractures]. / Versorgung von Patienten mit Fragilitätsfrakturen.

BACKGROUND: Fragility fractures are fractures in multimorbid, geriatric patients. Currently, their number is already high and is likely to increase in the future. OBJECTIVE: This article gives an overview of the principles in the management of patients with fragility fractures. MATERIAL AND METHODS: A selective literature review was performed to describe the epidemiology and relevance of fragility fractures. In addition, the principles of the perioperative management and surgical treatment of patients with fragility fractures are shown. RESULTS: Due to the significant number of comorbidities, the treatment of patients with fragility fractures represents an interdisciplinary challenge. Ideally, treatment should be carried out in an interdisciplinary team under the leadership of orthopedic surgeons and geriatricians. Treatment should be based on consensus guidelines, which have been adapted to the local circumstances. Attention should be paid to some special aspects of the surgical treatment in this vulnerable patient cohort. Important are optimal soft tissue management, cement augmentation procedures and joint replacement in cases of periarticular fractures. CONCLUSION: There is evidence that with optimal care the treatment of patients with fragility fractures can be significantly improved.

[Osteoporosis-epidemiology and quality of care]. / Osteoporose ­ Epidemiologie und Versorgungsqualität.

The present review gives a summary of recent epidemiological data on osteoporosis and the state of the quality of care especially regarding older adults. The results show that three quarters of all patients with vertebral and peripheral fractures are older than 65 years. Regarding hip fractures three out of four patients are older than 70 years. The association between age and fractures results as a direct consequence of the practically invariably present underlying osteoporosis and frequent falls in older adults.In Germany the prevalence of osteoporosis among women aged over 50 years is given as 24% and among men as 6%. In contrast to men where the incidence continues to rise, there is a small decrease of the incidence of hip fractures among women. Despite this decrease an enormous increase in both sexes is expected caused by the ongoing demographic changes with substantial socioeconomic consequences.Despite this development, the treatment rates of patients with osteoporosis or fragility fractures have remained low for many years. In contrast, national and international studies have shown that the rate of subsequent fractures could be reduced by up to 50% by using various measures to improve osteoporosis care, such as a fracture liaison service, providing adherence is maintained by the patients.

[Differential diagnoses of osteoporosis]. / Differenzialdiagnosen der Osteoporose.

The differential diagnoses of osteoporosis in geriatric and trauma patients are very important as they may induce different therapies. On average approximately 20% of women and 50% of men have secondary causes of osteoporosis. The foundation of the diagnostics is a basic osteological laboratory investigation with which the most important secondary causes can be identified. From a geriatric and traumatological point of view vitamin D deficiency with secondary hyperparathyroidism, primary hyperparathyroidism, male hypogonadism, multiple myeloma and monoclonal gammopathy of unclear significance (MGUS) are of particular importance.

[Peri-implant femoral fracture following hip arthrodesis in adolescence]. / Periimplantäre Femurfraktur nach Hüftarthrodese im Jugendalter.

This article presents the case of an 83-year-old woman with a peri-implant femoral fracture after hip arthrodesis in adolescence. Due to the rarity of such operations, there is no standardized approach for these cases. In order to secure the treatment goal of rapid pain-adapted full weight bearing despite reduced bone quality, it was decided to perform a new osteosynthesis with a retrograde femoral nail after removal of some fixation screws of the existing arthrodesis plate. Due to this type of treatment, the preservation of activity and independence of an older trauma patient could be sustainably secured despite operative challenges. Taking an extended osteoporosis treatment into consideration, a bony fracture consolidation and complete convalescence of activity and autonomy were ultimately achieved.

[Interdisciplinary management in geriatric trauma surgery : Results of a survey in Austria]. / Interdisziplinäres Management in der Alterstraumatologie : Ergebnisse einer österreichweiten Umfrage.

BACKGROUND: The treatment of geriatric patients in the field of trauma surgery is increasingly gaining importance. To provide optimized treatment to these mostly multimorbid patients, interdisciplinary treatment concepts between trauma surgeons and geriatricians have been designed and implemented successfully. OBJECTIVES: The aim of this survey was to evaluate the current state of interdisciplinary management in the treatment of geriatric patients on trauma surgery wards throughout Austria. MATERIAL AND METHODS: The directors of 64 Austrian trauma surgery wards were surveyed using an online-questionnaire regarding the current interdisciplinary treatment of geriatric patients. RESULTS: A total of 39 (61 %) questionnaires were analyzed. Of the participating wards, 20 % distinguished between geriatric and non-geriatric patients. There were various criteria to classify the patients. The average percentage of patients older than 70 years was 43 %. Of the participating wards, 26 % had established a periodical cooperation between trauma surgeons and geriatricians and 8 % of the participants stated that there is no interdisciplinary cooperation. The establishment of an interdisciplinary treatment concept in the near future was planned in 28 %. The most commonly mentioned obstacle that prevented trauma surgery wards from establishing an interdisciplinary management model was the lack of personnel resources (59 %) - especially the lack of geriatricians (62 %). CONCLUSION: The survey's results underline the geriatric trauma surgery's great importance especially regarding the high percentage of geriatric patients, as well as the fact that the significance of the interdisciplinary cooperation between trauma surgeons and geriatricians is not yet perceived by the majority of Austrian trauma surgery wards.

[Omission of osteoporosis diagnostics and therapy after fractures in the elderly : an avoidable treatment error?]. / Unterlassene Osteoporosediagnostik und -therapie nach Fraktur im Alter : Ein vermeidbarer Behandlungsfehler?

Through a more consistent diagnostics and treatment of osteoporosis, subsequent fractures and associated complications could be reduced in aged patients. Whereas anticoagulants are now standard in the treatment of fractures of the lower extremities to prevent thromboembolic complications in orthopedic surgery and an omission of anticoagulation can be regarded as medical malpractice, the management of osteoporosis following such fractures is very frequently disregarded. Although guidelines for osteoporosis, such as those from the governing body on osteology (Dachverband Osteologie, DVO) from 2014 are not legally binding as such, the breach of this standard of care can constitute a breach of medical obligation by the physician. The omission of osteoporosis diagnostics and initiation of treatment despite appropriate findings after fractures in aged patients, could represent a diagnostic assessment error and severe malpractice in the legal sense. In this case, evidence of a serious malpractice could be associated with civil, criminal and professional claims which could be linked with relevant legal consequences. Regardless of the legal consequences for omission of osteoporosis management following multiple fractures in aged patients, the management of osteoporosis should be an integral component in the treatment of these patients in the future.

[Augmentation techniques on the proximal femur]. / Augmentationstechnik am proximalen Femur.

BACKGROUND: Due to the demographic change fractures of the proximal femur are an increasing major healthcare problem and are associated with the highest mortality among frailty fractures. OBJECTIVES: These mainly osteoporosis-associated fractures of the hip often represent a surgical challenge and the outcome has a decisive influence on the preservation of function and independency of orthogeriatric patients. Augmentation techniques could improve the stability of osteosynthesis in proximal femoral fractures. METHODS: Cement augmentation of proximal femoral nailing (PFNA) for the treatment of pertrochanteric femoral fractures is the most commonly used and standardized method of augmentation for these fractures by which a safer condition for immediate full weight bearing and mobilization can be achieved. RESULTS: In biomechanical and clinical studies good fracture healing was shown and there was no evidence of cement-associated complications in augmented PFNA nailing. In the majority of patients the mobility level prior to trauma could be achieved. CONCLUSION: In addition to the optimal surgical treatment, secondary prevention such as osteoporosis management to avoid further fractures is crucial in the treatment of these patients. This article is based on the current literature and provides an overview of the possible applications of cement augmentation for the treatment of proximal femoral fractures. In addition the surgical approach as well as previous scientific data on an established osteosynthesis using cement-augmented PFNA for the treatment of pertrochanteric frailty fractures are presented.

[Identification, diagnostics and guideline conform therapy of osteoporosis (DVO) in trauma patients : a treatment algorithm]. / Identifikation, Diagnostik und leitliniengerechte Osteoporosetherapie (DVO) unfallchirurgischer Patienten : Ein Behandlungsalgorithmus.

Osteoporosis-associated fractures are of increasing importance in trauma surgery. The implementation of systematic diagnostics and treatment of osteoporosis during hospitalization, however, remains insufficient; therefore, a specific algorithm for the diagnosis and treatment of osteoporosis in trauma surgery patients was developed based on the German Osteology Society (Dachverband Osteologie, DVO) guidelines for osteoporosis from 2014. In a first step, the individual patient age and risk profile for osteoporosis are identified considering specific fractures indicative of osteoporosis. For these patients a questionnaire is completed which detects specific risk factors. In addition, the physical activity, risk of falls, dietary habits and the individual medication are collated as these can have a decisive influence on the subsequent therapy decisions. Prior to a specific treatment, laboratory osteoporosis tests, bone densitometry by dual energy X-ray absorptiometry (DXA) and if needed X-rays of the spine are carried out. For proximal femoral fractures the treatment of osteoporosis could already be indicated. With pre-existing glucocorticoid therapy, a history of previous fractures or other risk factors according to the risk questionnaire, the threshold of treatment has to be adjusted according to the table of T-scores detected by DXA. The treatment algorithm for diagnostics and treatment of osteoporosis in hospitalized trauma surgery patients can systematically and efficiently improve the identification of patients at risk. Thus, further fractures associated with osteoporosis or failure of internal fixation could be reduced in future. A prospective validation of the algorithm has already be initiated.

[New strategies for exercise training in osteoporosis]. / Innovatives Bewegungstraining bei Osteoporose.

In the prevention and treatment of osteoporosis, movement with muscle strengthening and proprioceptive training plays a major role. This was taken into consideration in the guidelines by the governing body on osteoporosis (Dachverband Osteoporose, DVO) from 2014 on prophylaxis, diagnosis and treatment of osteoporosis and in the DVO guidelines from 2008 on physiotherapy and exercise therapy for osteoporosis. Increases in lumbar bone density of between 0.5 % and 2.5 % can be achieved in women by strengthening exercises with high resistance. With this combination and strengthening of the quadriceps muscle a reduction of falls and hence the fracture risk could also be achieved. In traumatology, training for muscle strengthening is not always possible, especially for elderly patients. Practically relevant alternatives are regular walking and aquatraining, which may also lead to a significant increase in bone mineral density. Furthermore, large effects can be achieved with alternating side whole-body vibration (WBV) training with whole body vibration plates with only 3 days of training per week and with short training periods (15-20 min). Rates of increase in leg strength between 20 % and almost 40 % and in bone density between 0.5 % and 4 % in 6 months have been described. Whether and with what intensity whole body vibration therapy could be used for e.g. more rapid healing of fractures, is currently unclear. Initial positive results have been described in animal models.

[New DVO guideline for osteoporosis management 2014 and its importance for trauma surgeons]. / Neue Osteoporose-Leitlinie DVO 2014 und ihre Bedeutung für den Unfallchirurgen.

Osteoporosis-associated fractures represent a growing challenge in the treatment of orthopedic patients. In November 2014 a new revision of the guidelines on osteoporosis by the German Osteology Society (Dachverband Osteologie DVO) was adopted, in which additional risk factors for fractures and further treatment options have been included. On the one hand the existing model used to diagnose osteoporosis and estimate a high fracture risk as a guidance for the use of specific anti-osteoporotic therapy in patients without a fragility fracture was maintained and further refined. On the other hand the guideline includes the option to initiate a specific osteoporosis therapy without a prior bone densitometry in patients with typical radiographs of a proximal femur fracture and higher grade vertebral fractures, suspicious for osteoporosis, depending on the overall clinical context. This may reduce the treatment gap of osteoporosis in Germany. In this paper the changes in the DVO guidelines 2014 on osteoporosis are summarized, focusing on the most important changes with practical relevance for orthopedic surgeons.

[Osteological interdisciplinary management : exemplified by a bilateral proximal humeral fracture]. / Osteologisch-interdisziplinäres Management : Am Beispiel einer bilateralen proximalen Humerusfraktur.

Following locking plate osteosynthesis of a proximal humeral fracture, a 62-year-old male patient suffered mild secondary dislocation. Subsequent bone densitometry identified an osteoporosis. Laboratory testing and sonography revealed an underlying primary hyperparathyroidism. In the short term, the patient suffered a similar proximal humeral fracture of the contralateral side. Given the knowledge about the underlying osteoporosis a cement-augmented locking plate osteosynthesis was carried out to treat the fracture. Parathyroidectomy was performed shortly thereafter and laboratory parameters returned to normal. Secondary fractures did not arise. Treatment of this patient in a certified osteoporosis center with a multimodal management led to systematic interdisciplinary diagnostics, a specific surgical therapy and ended in an excellent result.

Survivorship of second-generation metal-on-metal primary total hip replacement.

BACKGROUND: Second generation metal-on-metal total hip replacements (THR) were introduced in the late 1980s and various studies reported conflicting data on their outcome. METHODS: Implant survival of 1,270 second-generation 28 mm metal-on-metal primary THR in 1,121 patients followed prospectively at a mean of 6.8 years postoperatively was evaluated retrospectively. The probability of survival at 10 years was estimated using the method of Kaplan and Meier, and relative risk factors including age, gender, BMI, type of implant fixation and component size were calculated using the Cox proportional-hazards model. RESULTS: Sixty-three (5%) THRs were revised, these being 28 hips for aseptic loosening and 35 for reasons other than aseptic loosening. The probability of survival at 10 years, with revision for any reason as the endpoint, was 0.90 (95% confidence interval (CI) 0.86-0.94) for the THR as a whole, 0.91 (95% CI 0.87-0.95) for the cup, and 0.96 (95% CI 0.94-0.98) for the stem. No demographic factors or covariates were found to significantly affect the implant survivorship. DISCUSSION: As there was no superior probability of survival, and there have been concerns on putative local and systemic toxicity of metal debris, the use of second-generation metal-on-metal articulations for primary THR remains moot.

Intraoperative torsion control using the cortical step sign and diameter difference in tibial mid-shaft fractures.

AIM: Intramedullar nailing of tibial mid-shaft fractures is a common surgical treatment. Fracture reduction, however, remains challenging and maltorsion is a common discrepancy which aggravates functional impairment of gait and stability. The use of radiographic tools such as the cortical step sign (CSS) and the diameter difference sign (DDS) could improve fracture reduction. Therefore, the validity of the CSS and DDS was analyzed to facilitate detection of maltorsion in tibial mid-shaft fractures. METHODS: Tibial mid-shaft fractures were induced in human cadaveric tibiae according to the AO classification type A3. Torsional discrepancies from 0° to 30° in-/external direction were enforced after intramedullary nailing. Fluoroscopic-guided fracture reduction was assessed in two planes via analysis of the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD), anterior cortical thickness (ACT), posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and distal fracture fragment. RESULTS: The TD, LCT and ACT have shown a highly significant correlation to predict tibial maltorsion. While a model combining ACT, LCT, PCT and TD lateral was most suitable model to identify tibial maltorsion, a torsional discrepancy of 15°was most reliably detected with use of the TD and ACT. CONCLUSION: The present study has shown, that maltorsion can be reliably assessed by the CSS and DDS during fluoroscopy. Thus, torsional discrepancies in tibial mid-shaft fractures can be most reliably assessed in the lateral plane by analysis of the LCT and TD.

Outcome after surgical treatment of fragility ankle fractures in a certified orthogeriatric trauma center.

INTRODUCTION: Orthogeriatric ankle fractures seem to play an essential role in terms of quality of life in the elderly. Knowledge of the outcome after orthogeriatric ankle fractures is sparse. The present study investigates the outcome after surgically treated ankle fractures at a certified orthogeriatric trauma center. MATERIAL & METHODS: A retrospective observational study was performed investigating the outcome of surgically treated ankle fractures in orthogeriatric patients between 2015-2017. Outcome parameters included but were not limited to the EQ-5D 3 L, Barthel Index, Karlsson Score and the Charlson Comorbidity Index. Housing situation and mobility were evaluated and potential associations to the fracture pattern and the related treatment strategy were investigated. RESULTS: In total, 58 patients were included (age 77.7 ±â€¯6,2 years). The majority were AO-44 B2 fractures (72%). General outcome was related to the Parker score; a Parker Score of 9 prior surgery was independently associated with an improved outcome according to the EQ-5D 3 L and Barthel Index. Patients under 80 years of age also had better results. Place of residence did not significantly change after surgery. Neither different types of implants nor initial use of an external fixator (e.g. open fractures) did influence outcome. A wound healing impairment was found in 10% of our patients whereas the overall unplanned reoperation rate was 7%. Overall complication rate was 20%, one-year mortality was 10%. CONCLUSIONS: Surgically treated ankle fractures in the elderly which are treated in a certified geriatric fracture center seem to have limited negative effect on their quality of life. We did not observe the otherwise often demonstrated high mortality rates, but still nearly half of the patients demonstrated perioperative complications, which emphasizes the need for optimal perioperative care at an orthogeriatric trauma center. Since there was a reasonable number of patients with wound healing issues this study supports the idea of a staged protocol using external fixation with secondary ORIF.

Trochanteric fragility fractures : Treatment using the cement-augmented proximal femoral nail antirotation.

OBJECTIVE: Use of standardized cement augmentation of the proximal femur nail antirotation (PFNA) for the treatment of trochanteric fragility fractures, which are associated with high morbidity and mortality, to achieve safer conditions for immediate full weight-bearing and mobilization, thus, improving preservation of function and independency of orthogeriatric patients. INDICATIONS: Trochanteric fragility fractures (type 31-A1-3). CONTRAINDICATIONS: Ipsilateral arthritis of the hip, leakage of contrast agent into the hip joint, femoral neck fractures. SURGICAL TECHNIQUE: Reduction of the fracture on a fracture table if possible, or minimally invasive open reduction of the proximal femur, i. e., using collinear forceps if necessary. Positioning of guidewires for adjustment of the PFNA and the spiral blade, respectively. Exclusion of leakage of contrast agent and subsequent injection of TRAUMACEM™ V(+) into the femoral head-neck fragment via a trauma needle kit introduced into the spiral blade. Dynamic or static locking of the PFNA at the diaphyseal level. POSTOPERATIVE MANAGEMENT: Immediate mobilization of the patients with full weight-bearing and secondary prevention, such as osteoporosis management is necessary to avoid further fractures in the treatment of these patients. RESULTS: A total of 110 patients older than 65 years underwent the procedure. Of the 72 patients available for follow-up (average age 85.3 years), all fractures healed after an average of 15.3 months. No complications related with cement augmentation were observed. Approximately 60 % of patients achieved the mobility level prior to trauma.

Value of a coordinated management of osteoporosis via Fracture Liaison Service for the treatment of orthogeriatric patients.

INTRODUCTION: The prevalence of osteoporosis in female patients over 75 years of age is 59.2 %. In Germany ~6.3-7.8 million patients are affected by osteoporosis. In 77 % of german patients osteoporosis is not treated adequately. Even after fragility fractures only 16-21 % of female patients and 3 % of male patients are supplied with a specific osteoporosis therapy. Establishing a Fracture Liaison Services (FLS) is a possible addition to co-management for an efficient treatment of osteoporosis in orthogeriatric patients. MATERIALS AND METHODS: According to a treatment algorithm adapted to the DVO guideline 2014, data of 251 (77 male, 173 female) patients were collected over 3 months. For the assessment specific and standardized questionnaires were used. There was also a basic laboratory testing for osteoporosis done. RESULTS: The average age of female patients was 76.1 years, in male patients 76.6 years. Thirty-seven patients had vertebral fractures, 25 patients proximal humerus fractures, 18 distal radius fractures and a total of 78 proximal femur fractures were recorded. Eighteen percent of the 251 patients have already been treated with a basic and 11 % with a specific osteoporosis medication. Approximately 40 % of the orthogeriatric patients were diagnosed with osteoporosis for the first time in our clinic. Less than 1 % of the patients had a vitamin D level over 40 ng/ml and 32 % had a vitamin D level under 10 ng/ml. Sixty-five percent of the discharged patients received a basic osteoporosis therapy and 25 % an additional specific therapy. DISCUSSION: Due to the demographic development osteoporosis-associated fractures steadily increase. In addition to the surgical treatment of fractures, osteological diagnosis and treatment are essential components of successful treatment and critical to the prevention of further fractures. A combination of orthogeriatric center and fracture liaison service allows a more efficient treatment of osteoporosis by close supervision of orthogeriatric patients by the physicians involved.

[Validity of digital templating in total hip arthroplasty: impact of stem design and planner's experience]. / Validität der computergestützten Hüfttotalendoprothesenplanung: Einfluss von Schaftdesign und Untersuchererfahrung.

INTRODUCTION: Preoperative planning in total hip arthroplasty decreases the risk of implant oversizing and facilitates intraoperative orientation. The size of the acetabular and femural components can be estimated. The aim of the present study was to determine the validitiy of digital templating. Furthermore, we compared the accuracy of three planners with different clinical experience and the effect of two different femoral component designs on planning accuracy. METHODS: On 60 a. p. pelvis radiographs, 60 unilateral, non-cemented total hip arthroplasties using the planning tool "AGFA-Orthopaedic-Tools Version V2.10®" (Fa. Agfa Health Care, Mertsel, Belgium) were repeatedly planned by three orthopaedic surgeons (planner A fifth year, planner B third year, planner C second year of training). All 60 patients received pressfit acetabular components, a straight stem was implanted in 28 (CLS-Spotorno™, Fa. Zimmer) and a short stem (Fitmore™, Fa. Zimmer) in 32 patients. The planned sizes of the components and the offset-variations were compared to the implanted sizes. RESULTS: The percental accuracy and ICC planning for the straight stem were 42.9 %/0.906 for planner A, 39.3 %/0.833 for planner B, and 28.6 %/0.836 for planner C. Planning the short stem, the percental accuracy and ICC were 34.4 %/0,886 for planner A, 21.9 %/0.708 for planner B, and 12.5 %/0.681 for planner C. The accuracy and ICC of templating the acetabular components were 35 %/0.796 for planner A, 30 %/0.725 for planner B, and 26.8 %/0.511 for planner C. Planning the sizes of both femoral components showed significant differences between planner A and C and planner B and C in Wilcoxon's signed-rank test. CONCLUSION: A lower level of experience showed no effect on the planning results of the acetabular components, but there were considerable and significant differences on planning the femoral components. Furthermore, the design of the femoral component had an impact on planning accuracy.

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.