Incidence Of Periprosthetic Fractures Research Articles

Callus formation after total hip arthroplasty using a short tapered-wedge stem.

The incidence of periprosthetic fractures after total hip arthroplasty using a short tapered-wedge stem is high. Callus formation preceding this fracture, which indicates postoperative stress fracture around the stem, has been reported. However, previous studies on postoperative callus are limited. Hence, the current study aimed to evaluate the prevalence and risk factors of postoperative callus after total hip arthroplasty with a short tapered-wedge stem. This retrospective study included 127 patients who underwent total hip arthroplasty using a cementless short tapered-wedge stem. The depth of stem insertion was measured as the distance from the lateral corner of the stem to the most medial point of the lesser trochanter along the body axis. Postoperative callus was defined as a bridging callus on the lateral femoral cortex at the distal end of the porous coating of the stem. Plain radiography was performed before surgery and immediately and at 1, 3, and 6months after surgery to assess postoperative callus. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for PC. In total, 60 (47.2%) of 127 patients presented with postoperative callus. Multivariate logistic regression analysis with postoperative callus as the dependent variable revealed that the stem depth at 1month after total hip arthroplasty (odds ratio, 1.14; 95% confidence interval, 1.04-1.24, p = 0.002) was a significant and independent risk factor of postoperative callus. Deep insertion of a short tapered-wedge stem is a risk factor for postoperative callus.

Periprosthetic Fractures: A Rising Tide of Hip Arthroplasty Failure Noted in the American Joint Replacement Registry and the Preventative Role of Cemented Stems

BackgroundThis investigation examined cemented femoral component use in total hip arthroplasty (THA) and its impact on the incidence of periprosthetic fractures (PPFx), a common failure mode in THA. The study leverages data from the American Joint Replacement Registry (AJRR) to assess trends in cemented femoral component usage over time, its association with PPFx rates, and compares the survivorship and 90-day complication rates between cemented and cementless femoral component THAs. MethodsPrimary THAs, captured in the AJRR, in patients aged 65 years and older from 2012 to 2021 were analyzed. Variables considered included age, sex, race, region, teaching status, year, Charlson comorbidity index, and institution bed size. Analysis compared fixation types for THA on all-cause linked revision and PPFx. Logistic regression models analyzed the odds ratios for all-cause linked revision and PPFx for any follow-up time as well as for 90-day revision. The models were adjusted for the listed variables. ResultsDuring the study period, the rate of cement utilization as a percentage of primary THAs performed and reported to the AJRR increased from 4.4 to 8.3%. The rate of THA failure from PPFx increased from 11.4 to 33.3%. When both fixation groups were compared in the univariate analysis, there was a statistically significant difference in all demographic variables (P < .001). To account for this, multivariable logistic regression models were applied. In our models, cemented stems showed a 54.4% (odds ratio: 0.456; 95% confidence interval: 0.347 to 0.599; P < .0001) and 65.8% (odds ratio: 0.342; 95% confidence interval: 0.237 to 0.493; P < .0001) lower risk of PPFx linked and PPFx early linked revision, respectively. ConclusionsPeriprosthetic fractures are becoming a leading failure mode for THAs in the AJRR. Given cemented fixation’s relative resistance to this failure mode compared to cementless fixation, we should consider increasing the utilization of this technique.

Comparison of Outcomes in Dual-Mobility Versus Fixed-Bearing Implants in Primary Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

Total hip arthroplasty (THA) is often regarded as one of the most successful surgical techniques developed in the twenty-first century. However, it is associated with complications such as prosthetic instability, dislocations, or infections. Dual-mobility (DM) implants have been developed with the goal of reducing the incidence of dislocations by increasing the femoral head-neck ratio, maximising hip stability, and improving the range of motion (ROM) before impingement and dislocation. This systematic review aims to comprehensively compare the safety and efficacy of DM versus fixed-bearing (FB) implants in primary THA patients. A comprehensive search strategy of PubMed, Embase, Scopus, and Web of Science Core Collection databases was executed to identify pertinent literature comparing DM and FB implants in THAs. Eligible studies underwent independent screening, and data were systematically extracted. The analysis employed pooled risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous variables, each accompanied by their respective 95% confidence intervals (CI). Our systematic review and meta-analysis included nine studies encompassing 22,277 patients. The DM group had a significantly reduced incidence of dislocations compared to the FB group (RR 0.25, 95%CI [0.13, 0.47]; p-value <0.0001) and a significantly shorter length of stay (MD -9.92, 95%CI [-15.53, -4.32]; p-value = 0.0005). The FB group, however, had a significantly shorter operative time compared to the DM group (MD 10.41, 95%CI [7.64, 13.17]; p-value < 0.00001). We did not identify any significant statistical differences between the DM and FB groups regarding patient-reported outcome measures, the incidence of all-cause readmissions, the incidence of peri-prosthetic fractures, the incidence of infections, or the incidence of groyne pain.

The cost-effectiveness of osteoporosis medications for preventing periprosthetic fractures following femoral neck fracture indicated hip arthroplasty: a break-even analysis.

Osteoporosis treatment following arthroplasty for femoral neck fracture (FNF) is associated with lower rates of periprosthetic fracture (PPF). Although cost-effective in reducing the rate of secondary fragility fracture, the economic viability of osteoporosis treatment in preventing PPF has not been evaluated. Therefore, the purpose of this study is to use a break-even analysis to determine whether and which current osteoporosis medications are cost-effective in preventing PPF following arthroplasty for FNFs. Three-year average cost of osteoporosis medication (oral bisphosphonates, estrogen hormonal therapy, intravenous (IV) bisphosphonates, denosumab, teriparatide, and abaloparatide), costs of PPF care, and PPF rates in patients who underwent hip arthroplasty for FNFs without osteoporosis treatment were used to perform a break-even analysis. The absolute risk reduction (ARR) related to osteoporosis treatment and sensitivity analyses were used to evaluate the cost-effectiveness of this intervention and break-even PPF rates. Oral bisphosphonate therapy following arthroplasty for hip fractures would be economically justified if it prevents one out of 56 PPFs (ARR, 1.8%). Given the current cost and incidence of PPF, overall treatment can only be economically viable for PPF prophylaxis if the 3-year costs of these agents are less than $1500. The utilization of lower cost osteoporosis medications such as oral bisphosphonates and estrogen hormonal therapy as PPF prophylaxis in this patient population would be economically viable if they reduce the PPF rate by 1.8% and 1.5%, respectively. For IV bisphosphonates and newer agents to be economically viable as PPF prophylaxis in the USA, their costs need to be significantly reduced.

Does Size Really Matter? Incidence of Periprosthetic Fractures After Femoral Osteotomy in Patients With Cerebral Palsy.

Of children, 30% to 35% with cerebral palsy (CP) develop hip subluxation or dislocation and often require reconstructive hip surgery, including varus derotation osteotomy (VDRO). A recent literature review identified postoperative fractures as the most common complication (9.4%) of VDROs. This study aimed to assess risk factors for periprosthetic fracture after VDRO in children with CP. A total of 347 patients (644 hips, 526 bilateral hips) with CP and hip subluxation or dislocation (129 females; mean age at index VDRO: 8.6 y, SD 3.4, range: 1.5 to 17.7; 2 Gross Motor Function Classification System (GMFCS) I, 35 GMFCS II, 39 GMFCS III, 119 GMFCS IV, 133 GMFCS V, 21 unavailable) were included in this retrospective, single-group intervention (VDRO) study at a tertiary referral center. Imaging and clinical documentation for patients age 18 years or younger at index surgery, treated with VDRO were reviewed to determine demographic data, GMFCS level, surgeon, type of hardware implanted, use of anticonvulsants and steroids, type of postoperative immobilization, presence of periprosthetic fractures, fracture location and mechanism, and time from surgery to fracture. Potential determinants of periprosthetic fractures were assessed using mixed effects logistic regression. Of 644 hips, 14 (2.2%, 95% CI: 1.3%, 3.6%) sustained a periprosthetic fracture, at a median of 2.1 years postoperatively (interquartile range: 4.6 y, range: 1.2 mo to 7.8 y). Patients with a fracture had a median age at index surgery of 7.3 years (interquartile range: 4.3, range: 2.8 to 17.8; 1 GMFCS II, 6 GMFCS IV, 7 GMFCS V). Periprosthetic fractures were not significantly related to age at index surgery ( P = 0.18), sex ( P = 0.30), body mass index percentile ( P = 0.87), surgery side ( P = 0.16), anticonvulsant use ( P = 0.35), type of postoperative immobilization ( P = 0.40), GMFCS level ( P = 0.31), or blade plate size ( P = 0.17). Only surgeon volume significantly related to periprosthetic fracture (odds ratio = 5.03, 95% CI: 1.53, 16.56, P = 0.008), with the highest-volume surgeon also using smaller blade plates ( P < 0.01). Periprosthetic fractures after VDRO surgery in children with CP are uncommon, and routine hardware removal appears unnecessary. The data suggest that the common dogma of putting in the largest blade plate possible to maximize fixation may increase the risk of periprosthetic fracture. Due to the overall low fracture rate, especially when contextualized relative to the risk of hardware removal, a reactive approach to hardware removal appears warranted. Level III-retrospective study (targeting varus derotational osteotomies in children with cerebral palsy).

A lower canal fill rate and unreestablished vertical femoral offset may increase the risk of the postoperative periprosthetic fractures after cementless bipolar hemiarthroplasty for femoral neck fractures in elderly patients.

Periprosthetic fractures (PPFs) is one of the major causes of failure of hip arthroplasty with cementless stem; however, studies on the incidence and risk factors of PPFs after cementless hemiarthroplasty for femoral neck fractures (FNFs) are lacking. This retrospective study included patients who underwent cementless bipolar hemiarthroplasty for displaced intracapsular FNFs. The demographic data were reviewed, Dorr classification was used to describe morphology of the femur, radiological parameters were measured including stem-shaft angle, canal fill ratio (CFR), canal flare index (CFI), morphologic cortical index (MCI), canal calcar ratio (CCR), and vertical and horizontal femoral offset. The sample comprised 10 men and 46 women (affected hip: left, 38; right, 18). The mean patient age was 82.82±10.61 (range, 69-93) years, and the mean hemiarthroplasty to PPFs time was 26.28±14.04 (range, 6.54-47.77) months. Seven (12.28%) patients had PPFs. A significant relationship was found between the incidence of PPF and CFR (p = 0.012), patients had a significantly smaller femoral stem CFR (0.76%±0.11%) than controls (0.85%±0.09%). The PPFs group had a significant shorter and unreestablished vertical femoral offset (p = 0.048). A smaller femoral stem CFR associated with a potentially unacceptably high PPFs risk in uncemented hemiarthroplasty for displaced FNFs may result from mismatched prosthesis and bone dimensions in the elderly population, especially when accompanied by a poorly reestablished vertical femoral offset. With increasing evidence of the benefits of cemented fixation, a cemented stem for the treatment of displaced intracapsular FNFs is recommended for such a elderly frail population.

Periprosthetic Fracture around a Cemented Stem in Total Hip Arthroplasty.

The increase in the number of primary total hip arthroplasties that will be performed over the next several decades will lead to an increase in the incidence of periprosthetic fractures around the femoral stem. A search of targeted articles was conducted using on-line databases of PubMed (National Library of Medicine) and articles were obtained from January 2008 to November 2021. Reliable prediction of treatment can be achieved using the Vancouver classification; internal fixation is indicated in fractures involving a stable implant and revision arthroplasty is indicated in those with unstable prostheses. To the best of our knowledge, relatively fewer studies regarding periprosthetic proximal femur fractures of cemented stems have been reported. The focus of this review is on the risk factors and strategies for treatment of these fractures for periprosthetic femoral fractures around a cemented hip arthroplasty.

Metal and composite bone plates for B1 periprosthetic femoral fracture in healthy and osteoporotic condition: A comparative biomechanical study.

The major concern after total hip arthroplasty (THA) is the incidence of periprosthetic fracture in the weaker bone, which can lead to subsequent revision surgery. Achieving the suitable fixation without affecting the stability of the well-fixed prosthesis remains controversial. Most of the studies examined the behavior of the Periprosthetic Fracture (PF) fixation (Vancouver "B1" type) through computational and experimentation on healthy bone condition with metal plates. The aim of the present study is to analyze the influences of the metal and composite bone plate PF fixation on the axial and shear movement at the fracture site. The PF fixation constructs were modeled with medical graded stainless-steel plate (construct A), titanium plate (construct B) and carbon/epoxy composite bone plate (construct C) with 12 holes and a 4 mm fracture gap. Analysis was carried out for all the stages (stage 1-Normal bone, stage 2-THA, stage 3-Immediate Post-Operative (IPO), stage 4-Post-Operative (PO) and, stage 5-Healed Bone (HB)) under various loadings for intact and osteoporosis conditions. The results showed higher stress in cortical bone for stage 3, whereas in all the other stages lower stresses were experienced in the cortical and cancelous bone under peak load in construct C for osteoporosis model compared with other constructs. The present study suggested the construct C may be suitable for osteoporosis bone conditions.

Current Incidence and Future Projection of Periprosthetic Fractures in South Korea: A Study Based on National Claim Database.

ObjectiveTo evaluate the current incidence and economic cost and to estimate the future burden of periprosthetic fracture (PF) after joint arthroplasties in South Korea.MethodsThis study was a retrospective registry‐based study of patients who were diagnosed as periprosthetic fractures (PFs) in South Korea. Cases of PF from 2010 to 2017 in South Korea using Health Insurance and Review and Assessment (HIRA) database, which contains all medical claims for all South Korean patients, were identified. The operational definitions of PFs were identified from the Electronic Data Interchange (EDI) code of the Korean National Health Insurance Program (KHNIP). The annual incidence and medical costs during the period were calculated and the future increase of PF and its cost were projected through 2030 using generalized linear model with quasi‐poisson link.ResultsDuring the 8‐year period, 14,456 patients were treated due to PFs. The annual number of patients with PF remarkably increased from 1,322 in 2010 to 2,636 in 2017. The increment was prominent in age groups of 70–79 and ≧80. Total number of patients with PF were 9752 in women and 4704 in men during the study period. Mean personal costs were 1,155.4 USD in women and 1,185.5 USD in men. The total cost of PFs increased from 779,533 USD in 2010 to 3,888,402 USD in 2017. The personal cost of PFs also increased from 589.7 USD in 2010 to 1,475.1 USD in 2017. In 2017, the number of PF patients exponentially increased after 50 years of age especially in women. Estimated with our projection model, the number of PFs will increase by 2.5 times and the cost will increase by 10 times in the next 10 years.ConclusionThe incidence and cost of PFs are rising and will represent a serious socioeconomic burden in South Korea.

Biomechanics of periprosthetic femur fractures and early weightbearing.

The incidence of periprosthetic fractures is expected to rise increase by 4.6% every 10years between 2015 and 2060. There are few large series examining optimal fixation constructs or the influence of early ambulation on outcome. The purpose of this narrative review is to investigate the published biomechanical considerations for periprosthetic fracture fixation, with specific consideration of early postoperative weightbearing. A literature review was performed to identify fracture incidences, etiology, and current trends in weightbearing after fixation. Benefits of early weightbearing, current constructs, and biomechanics are reviewed. The limited data available support medical benefits and increased union rates with early mobilization. Optimal fixation constructs are not agreed upon, but mechanical studies suggest that dual implant constructs can support physiologic weightbearing loads. Further clinical trials are required to investigate fracture union and hardware complications in dual implant construct.

The challenge of total knee arthroplasty periprosthetic fracture: a comprehensive review

Total knee arthroplasty (TKA) is a common procedure in orthopeadic surgery. It has been estimated that the incidence of periprosthetic fractures after TKA ranged between 0.3 to 2.5%, but increases to 38% when considering revision TKA.Patient-related risk factors for TKA periprosthetic fracture (TKAPF) include osteoporosis, age, female gender, revision arthroplasty and osteolysis. The choice of the most appropriate fixation device of TKAPF is a matter of debate, considering that locking plates and retrograde intramedullary are both associated with good outcomes in terms of fracture union and joint function.In case of prosthetic component instability, severe comminution or metaphyseal extension of the fracture that precludes fixation, failure of previous treatments, and severe malalignment of the TKA, revision TKA (RTKA) should be considered. Severe bone loss is another issue of concern, that might be addressed using both megaprosthesis or allograft-prosthesis composite. Considering the variability of the clinical scenario of TKAPF, a comprehensive approach based on both fracture fixation and/or revision arthroplashty is needed.

Vancouver type-b1 periprosthetic fracture managed with locked compression plate: A case report

The incidence of periprosthetic fractures around the femoral stem is increasing. These are very challenging fractures and need adequate surgical expertise. There is no clear consensus regarding the management of these fractures, especially Vancouver type-B fractures. We report a case of Vancouver type-B1 fracture managed only with locked compression plate in a 70-year-old man. Fracture united at 3 months and at one year the patient had excellent functional and radiological outcome.

Finite Element Modeling Application in Forensic Practice: A Periprosthetic Femoral Fracture Case Study.

The incidence of periprosthetic fractures has rapidly increased in the last two decades and has been the cause of a large number of revision surgeries and permanent physical disability for many patients, as well as a significant socioeconomic burden for many nations. This research deals with a periprosthetic femur fracture real event, occurred following a total hip arthroplasty and treated with one of the most widespread internal fixation methods: the implant of a periprosthetic femur plate system. A Finite Element analysis was performed to investigate the implanted femur plate break after a short follow-up and to understand the plate break causes. Such events are currently object of forensic debate as more and more often hospitals, surgeons, and medical device manufacturers are denounced by patients to whom similar events occur. In this work, different load situations acting on the femur during daily and incidental activities were simulated, in order to validate the correct behavior of the plate, according to the intended use recommended by the manufacturer. The analysis demonstrates that the plate failure can occur in situations of unconventional loading such as that caused by stumbling and in presence of incomplete bone healing.

Periprosthetic fractures of the hip

The incidence of periprosthetic fractures around the hip is on the rise. Older patients have poor bone stock and treating these fractures is increasingly challenging. They most commonly affect the femur around a hip arthroplasty implant. Although uncemented implants have been implicated more than cemented implants, the contribution of implant fixation or geometry is poorly investigated. We revisit the Unified Classification System (UCS) and summarize the evidence on how to manage these fractures including the choice of implants available.

Periprosthetic fractures of the proximal femur within first year of the index hip prosthesis.

Introduction:Periprosthetic fractures are a serious complication of implants prosthetic. The aim of this review is to analyze incidence and predisposing factors of periprosthetic fractures of the proximal femur within first year of the index hip prosthesis.Materials and methods:Between 1998 and 2017 we have performed 4240 hip replacements (F 2661, M 1579): 2877 total hip arthroplasties (67,9%) and 1363 hemiartrhoplasties (32,1%). Hip replacements with cemented stem were 2173 (51,2%), while cementless ones were 2067 (48,8%). In the same period we admitted 121 hip periprosthetic fractures, 26 of which (0,6%) within the first year of the index surgery. We examined the medical and radiographic records of this last cohort of patients (F 19, M 7) following the Vancouver System, Dorr Classification and Stem Size Index.Results:The cause was a low-energy trauma in 25 cases (96.1%); the primary diagnosis was hip fracture in 20 patients (76.9%); 8 patients were taking chronic osteoporosis medication (30.7%); 14 patients were affected by neuropsychiatric disease (53.8%); cementless stems were found in 18 cases, 12 of which were oversized (SSI < 0,8). According to Vancouver System, fractures were classified as follows: 10 type B1, 14 type B2 and 2 type C. As far as the proximal femoral shape, 2 cases were Dorr type A, 7 Dorr type B and 17 Dorr type C.Conclusions:The incidence of periprosthetic fractures in the aftermath of stem implant is twice as high with uncemented stems. The Vancouver type B1/B2 is the most common. Predisposing factors are: female sex, hip fracture, chronic osteoporosis medication, neuropsychiatric disease and oversized uncemented stem (SSI < 0.8).The evidence level is IV. (www.actabiomedica.it)

Vancouver B3 Fractures: Treatment Options and Tips.

The incidence of periprosthetic fracture around hip arthroplasty has increased with the rise of total hip arthroplasty. These fractures are challenging to treat and often require revision of the femoral prosthesis. Vancouver B3 fractures are particularly difficult to treat because of extensive bone loss and limited options. A revised stable femoral component requires distal femoral fixation. Most cases can be performed with a tapered component or a long-stem fully coated prosthesis. Femoral allograft composite and proximal femoral replacement has been recommended for Vancouver B3 fractures with extremely poor bone stock but is rarely performed today. We present our surgical technique, as well as pearls and pitfalls in treating Vancouver B3 fractures with a loose prosthesis and proximal bone loss.

Periprosthetic Fractures after Total Knee Arthroplasty: the Influence of Pre-Operative Mechanical Factors versus Intraoperative Factors.

Introduction: Periprosthetic fractures are a devastating complication following total knee arthroplasty. Little is known about the effect of mechanical factors on the incidence of periprosthetic fractures. The aim of this study was to examine the correlation between pre-operative mechanical factors, like side of surgery, coronal alignment and pre-operative range of motion and intra-operative factors, and the incidence of a periprosthetic fracture, following primary total knee arthroplasty (TKA).Materials and Methods: Forty-two patients with periprosthetic fractures (PPF) after primary TKA were identified from our hospital arthroplasty registry. These patients were matched two-to-one for gender and age at primary knee arthroplasty to 84 patients without PPF. The incidence of periprosthetic fracture with regards to laterality, coronal alignment and pre-operative range of motion was analysed. Intra-operative factors like implant type, patellar resurfacing and notching were also analysed using logistic regression.Results: Coronal alignment, pre-operative range of motion and patella resurfacing were not significant predictors of periprosthetic fractures. Anterior femoral notching was found to be significantly higher in the fracture group with an odds ratio of 17. Left sided surgery was also significantly higher in the periprosthetic fracture group.Conclusion: Periprosthetic fractures are 17 times more likely to occur in a knee with anterior femoral notching. Preoperative factors like coronal alignment and poor preoperative range of motion do not seem to increase the risk of periprosthetic fractures after TKA.

Analysis of prosthesis survival after primary hip arthroplasty in elderly patients with Parkinson's syndrome

To explore the effect of Parkinson's syndrome on the survival of prosthesis after primary hip arthroplasty in elderly patients with femoral neck fracture. Methods: A total of 81 elderly patients (81 hips) with femoral neck fracture and primary hip replacement surgery, who came from the Department of Orthopaedics, Central Hospital of Xiangtan City from January 1, 2009 to December 30, 2010, were retrospectively analyzed, including 36 males and 45 females. Sixteen patients with Parkinson's syndrome were selected as a Parkinson's syndrome group, and the other 65 patients were served as a control group. The survival status of the prosthesis was followed up to December 30, 2017 and it was compared between the 2 groups (average follow-up was 7.5 years). Results: During the follow-up period, 5 patients in the Parkinson's group underwent revision of the hip joint, and the reasons for revision were periprosthetic fracture in 4 patients and aseptic loosening in 1 patient, but there was no dislocation or infection. There were 7 cases of revision in the control group, including 1 case of infection, 4 cases of aseptic loosening, 1 case of periprosthetic fracture, and 1 case of dislocation. In the follow-up period, the revision rate was 31.2% in the Parkinson's group and 10.8% in the control group (P<0.05). Parkinsonism was a risk factor for hip revision (OR=3.77, 95% CI 1.12 to 3.15). The incidence of periprosthetic fractures in the Parkinson's group was significantly higher than that in the control group (P<0.05). There was no statistical difference in the revision of the hip joint because of aseptic loosening, infection, and dislocation between the 2 groups (P>0.05). Conclusion: During an average of 7.5 years of follow-up, the older patients in the Parkinson's syndrome group have higher prosthetic failure rates after primary hip arthroplasty than those in the control group. The periprosthetic fractures are the most common causes. The development of individualized surgical procedures, the implementation of step-by-step rehabilitative exercises, and the suitable protective measures, and the enhancement of drug management and anti-osteoporosis treatment for Parkinson's syndrome may have positive implications for improving the survival of prosthesis in such patients.

Cementless short-stem total hip arthroplasty in the elderly patient - is it a safe option?: a prospective multicentre observational study

BackgroundDue to its bone preserving philosophy, short-stem total hip arthroplasty (THA) has primarily been recommended for young and active patients. However, there may be benefits for elderly patients given a less invasive operative technique due to the short curved implant design. The purpose of this study was to compare the clinical and radiological outcomes as well as perioperative complications of a calcar-guided short stem between a young (< 60 years) and a geriatric (> 75 years) population.MethodsData were collected in a total of 5 centers, and 400 short-stems were included as part of a prospective multicentre observational study between 2010 and 2014 with a mean follow-up of 49.2 months. Preoperative femur morphology was analysed using the Dorr classification. Clinical and radiological outcomes were assessed in both groups as well as perioperative complications, rates and reasons for stem revision.ResultsNo differences were found for the mean visual analogue scale (VAS) values of rest pain, load pain, and satisfaction, whereas Harris Hip Score (HHS) was slightly better in the young group. Comparing both groups, none of the radiological parameters that were assessed (stress-shielding, cortical hypertrophy, radiolucency, osteolysis) reached differences of statistical significance. While in young patients aseptic loosening is the main cause of implant failure, in the elderly group particularly postoperative periprosthetic fractures due to accidental fall have to be considered to be of high risk. The incidence of periprosthetic fractures was found to be 0% in Dorr type A femurs, whereas in Dorr types B and C fractures occurred in 2.1 and 22.2% respectively.ConclusionsAdvanced age alone is not necessarily to be considered as contra-indications for calcar-guided short-stem THA, although further follow-up is needed. However, markedly reduced bone quality with femur morphology of Dorr type C seems to be associated with increased risk for postoperative periprosthetic fractures, thus indication should be limited to Dorr types A and B.Trial registrationGerman Clinical Trials Register; DRKS00012634, 07.07.2017 (retrospectively registered).

MON-509 Crack in My Bone of Certain Significance: Clinical Vignette and Literature Review

Background: Overall incidence of periprosthetic fractures is <1% to 2.3% while that of postoperative periprosthetic fractures (<90 days) is 2.1%.1 Factors associated with postoperative periprosthetic fractures include uncemented femoral stem, osteoporosis, females sex, higher age, high BMI, anatomical deformities and previous surgery.1 We present an intriguing case of POST-OP periprosthetic fracture in a woman with normal bone mineral density (BMD) and discuss potentially unrecognized risk factors. Case: 77 year old woman, with a history of osteoarthritis, on daily Celecoxib 200 mg for three decades, was seen in Osteoporosis clinic. She underwent elective left total hip replacement. On postoperative day 1 she experienced acute left hip pain. CT showed acute spiral periprosthetic left hip fracture with intact femoral and acetabular components of the arthroplastic joint. Surgical revision with replacement of a longer stem was done. She returned to protected weight-bearing activity with a cane 3 months after surgery, with significant limitation of hip muscle strength and some pain in the involved hip. She continued taking Celecoxib. Bone density scan showed a BMD of 1.514 g/cm2 and a T-score of +2.8 at L1-L4, 0.950 g/cm2 and -0.6 at femoral neck, and 0.885 g/cm2 and -1.0 at hip. Serum calcium, albumin, phosphorous, vitamin D, creatinine and bone alkaline phosphatase were normal. Free kappa light chains were elevated, 4.53 mg/dL (0.33-1.94) and alpha-2 fraction was 14% (8.6-13.1). She had no proteinuria or skeletal lesions and was diagnosed with monoclonal gammopathy of undetermined significance (MGUS). It is unclear whether chronic use of selective COX-2 inhibitors and/or MGUS played a role in development of the periprosthetic fracture in our patient. Discussion: Previous studies show that selective COX-2 inhibitors can affect bone health by increasing BMD, simultaneously decreasing fracture healing.2 Individuals with MGUS have 1.7 fold risk of overall and 6.3 fold of vertebral fractures.3 Our patient was female, elderly and had uncemented stem, however, we speculate that MGUS and long-term COX-2 inhibitor use may have contributed to fracture risk in this patient. Since periprosthetic fractures are associated with significant morbidity, delayed healing and worse outcomes, it may be prudent for physicians to assess for such risk factors prior to surgery in order to identify at risk patients.