Diagnosis and Management of Intraoperative Periprosthetic Fractures in Primary Total Knee Arthroplasty.

Intraoperative periprosthetic fracture is an uncommon but notable complication that can occur during primary total knee arthroplasty. These fractures may occur at various stages during the procedure, including surgical exposure, implant preparation, implant trialing, and final implantation. Management of femoral and tibial fractures necessitates intraoperative recognition, including attentiveness of preoperative patient and surgical risk factors. This comprehensive review article focuses on the patient and surgical risk factors, diagnosis, management, and outcomes related to intraoperative fractures during primary total knee arthroplasty.

Incidence and Risk Factors for Fracture-Related Infection After Peri-Prosthetic Femoral Fractures: A Multicenter Retrospective Study (TRON Group Study).

Background: Fracture-related infection (FRI) sometimes occurs with peri-prosthetic femoral fracture (PPF) treatment. Fracture-related infection often leads to multiple re-operations, possible non-union, a decreased clinical function, and long-term antibiotic treatment. In this multicenter study, we aimed to clarify the incidence of FRI, the causative organisms of wound infection, and the risk factors associated with post-operative infection for PPF. Patients and Methods: Among 197 patients diagnosed with peri-prosthetic femoral fracture who received surgical treatment in 11 institutions (named the TRON group) from 2010 to 2019, 163 patients were included as subjects. Thirty-four patients were excluded because of insufficient follow-up (less than six months) or data loss. We extracted the following risk factors for FRI: gender, body mass index, smoking history, diabetes mellitus, chronic hepatitis, rheumatoid arthritis, dialysis, history of osteoporosis treatment, injury mechanism (high- or low-energy), Vancouver type, and operative information (waiting period for surgery, operation time, amount of blood loss, and surgical procedure). We conducted a logistic regression analysis to investigate the risk factors for FRI using these extracted items as explanatory variables and the presence or absence of FRI as the response variable. Results: Fracture-related infection occurred after surgery for PPF in 12 of 163 patients (7.3%). The most common causative organism was Staphylococcus aureus (n = 7). The univariable analysis showed differences for dialysis (p = 0.001), Vancouver type (p = 0.036), blood loss during surgery (p = 0.001), and operative time (p = 0.001). The multivariable logistic-regression analysis revealed that the patient background factor of dialysis (odds ratio [OR], 22.9; p = 0.0005), and the operative factor of Vancouver type A fracture (OR, 0.039-1.18; p = 0.018-0.19) were risk factors for FRI. Conclusions: The rate of post-operative wound infection in patients with a PPF was 7.3%. Staphylococcus was the most frequent causative organism. The surgeon should pay attention to infection after surgery for patients with Vancouver type A fractures and those undergoing dialysis.

How Advancement in Bone Science Should Inform the Examination and Treatment of Femoral Shaft Bone Stress Injuries in Running Athletes.

Stress fractures likely have a 1-2% incidence in athletes in general. In runners, a more vulnerable population, incidence rates likely range between 3.2 and 21% with female runners having greater susceptibility. The incidence of femoral shaft stress fractures is less well known. New basic and translational science research may impact the way clinicians diagnose and treat femoral stress fractures. By using a fictitious case study, this paper applies bone science to suggest new approaches to evaluating and treating femoral shaft stress fractures in the running population.

Arthroscopically assisted reduction and internal fixation of a femoral anterior cruciate ligament osteochondral avulsion fracture in an 11-year-old girl: A case report.

RATIONALE: The anterior cruciate ligament (ACL) is relatively rarely injured in children and adolescents, accounting for just 0.5% of all ACL rips that occur. Avulsion fractures are more common in youngsters because their ligamentous structures are known to be stronger than their physical insertion sites. Tibial eminences have been reported to be the sites of most ACL avulsions, and both cartilaginous and osteochondral avulsion fractures have been observed, whereas the latter occurs more commonly. On the other hand, femoral osteochondral avulsion fractures of the ACL in children are uncommon, as only a few studies describe their occurrence in immature patients. PATIENT CONCERNS: In this case report, we present an 11-year-old girl who suffered an ACL femoral attachment avulsion fracture after pivoting her knee during riding. A comprehensive formal evaluation of the knee was impractical due to the persistence of pain and tight haemarthrosis. DIAGNOSES: Femoral anterior cruciate ligament osteochondral avulsion fracture. INTERVENTIONS: We used Two No.2Ethibond sutures to pick up the osteochondral fragment and passed across the lateral femoral condyle to come out laterally and fixed with a tie proximally, and we recommended the patient perform reasonable functional exercises postoperatively. OUTCOMES: The patient had no pain, instability, or activity limitations after 24 months of surgery. Physical examination of the patient revealed full and symmetric ROM, and normal Lachman and pivot shift test performance. LESSONS: ACL avulsion fractures can be accurately treated with arthroscopic reduction and sutures via an inside-out technique, which can reduce the risk of persistent ligamentous laxity and reduce open surgery-related morbidity.

[Mortality in patients with proximal femur fractures undergoing conservative and surgical treatment]. / Letal'nost' u patsientov s perelomami proksimal'nogo otdela bedrennoi kosti pri konservativnom i operativnom lechenii.

OBJECTIVE: To study the incidence of proximal femur fractures (PFF) in St. Petersburg and survival rate depending on treatment strategy. MATERIAL AND METHODS: Considering the data of long-term monitoring of traumatology and orthopedic service in St. Petersburg, we assessed the incidence of PFF in adults and various treatment options. Moreover, we have studied all patients admitted to 2 large hospitals in St. Petersburg between December 2017 and December 2018 for at least 14 months. There were 914 requests for medical care for PFF from 903 patients. RESULTS: Mean incidence of PFF in St. Petersburg is 0.88 per 1000. The discharged patients without surgical care make up 20%. About 37.5% and 42.4% of patients require hip arthroplasty or osteosynthesis, respectively. Postoperative mortality was 3.5%, in-hospital mortality after therapeutic management - 9.1% (p=0.016). Two-year mortality after osteosynthesis was 27.2%, after hip arthroplasty - 19.3%, after conservative treatment - 43.9% (p<0.001).

Minimally invasive plate osteosynthesis for complex comminuted bone fractures in the Fraser's type II floating knee: a case report.

OBJECTIVE: Floating knee type IIC, according to Fraser's classification, is an uncommon severe injury that typically occurs in polytrauma. In such cases, intra-articular fracture and the high degree of comminution and deformity of the mid-distal femur make fixation challenging. The purpose of this study was to demonstrate that minimally invasive plate osteosynthesis (MIPO) technology can simplify these complex problems and improve patient prognosis. CASE PRESENTATION: A 38-year-old man injured his left leg in a car accident, causing pain, swelling, deformity, and limited mobility on his left knee and thigh, and two small open wounds were noted mainly of the anterior aspect of the mid-distal thigh. Physical examination and computed tomography angiography of the lower limb confirmed that there was no damage to the neurovascular system. The clinical diagnosis was closed intra-articular fracture of the proximal tibia, open intra-articular fracture of the distal femur with extension to the diaphysis, and a patellar fracture on the ipsilateral knee. The treatment strategy involved a locking plate system applying MIPO technology. Postoperative evaluation of the patient was satisfactory, with immediate functional exercise, full weight-bearing after three months, and return to daily activity without pain. Final follow-up taken 3 years after surgery showed good lower limb alignment and complete plasticity of the bone structure, by which time the patient showed good limb function. CONCLUSIONS: Minimally invasive techniques can provide a simple and effective treatment for some complex fractures.

Predictors of Mortality and Refracture in Patients Older Than 65 Years With a Proximal Femur Fracture.

OBJECTIVES: To evaluate potential predictors of subsequent fracture and increased mortality in a population 65 years or older who suffered a proximal femur fragility fracture. METHODS: This was a longitudinal study that included patients with a proximal femur fragility fracture, referred from the Orthopedics Inpatient Department to the Rheumatology Department's Fracture Liaison Service, from March 2015 to March 2017. RESULTS: Five hundred twenty-two patients were included, with a median age (IQR) of 84 years (interquartile range [IQR], 11 years), 79.7% (n = 416) female. Nine percent (n = 47) suffered a new fracture, with a median time to event of 298 days (IQR, 331 days). Cumulative probability without refracture at 12 months was 93% (95% confidence interval [CI], 90.2%-95.0%); 22.8% (n = 119) patients died, with median time to death of 126 days (IQR, 336 days). Cumulative survival probability at 12 months was 81.7 (95% CI, 77.9-84.8). Neurologic disease (hazard ratio [HR], 2.30; 95% CI, 0.97-5.50; p = 0.06) and chronic obstructive pulmonary disease (HR, 3.61; 95% CI, 1.20-10.9; p = 0.022) were both predictors of refracture. Age older than 80 years (HR, 1.54; 95% CI, 0.99-2.38; p = 0.052), higher degree of dependence (HR, 1.24;95% CI, 1.09-1.42; p = 0.001), male sex (HR, 1.55; 95% CI, 1.03-2.33; p = 0.034), femoral neck fracture (HR, 0.45; 95% CI, 0.24-0.88; p = 0.018), Charlson score (HR, 2.08; 95% CI, 1.17-3.69; p = 0.012), heart failure (HR, 2.44; 95% CI, 1.06-5.63; p = 0.037), hip bone mass density (HR, 3.99; 95% CI, 1.19-13.4; p = 0.025), hip T score (HR, 0.64; 95% CI, 0.44-0.93; p = 0.021), and ß-crosslaps (HR, 1.98; 95% CI, 1.02-3.84; p = 0.042) all predicted a higher mortality. CONCLUSIONS: Neurologic disease and chronic obstructive pulmonary disease may increase the risk of subsequent fracture after a hip fracture. Male sex, age, autonomy degree, femur bone mass density/T score, fracture type, Charlson score, diabetes mellitus, heart failure, and ß-crosslaps had significant impact on survival. The authors highlight ß-crosslaps as a potential serological marker of increased mortality in clinical practice.

Use of Lesser Trochanter Profile as a Rotational Alignment Guide in Intramedullary Nailing for Femoral Shaft Fracture.

BACKGROUND: Malrotation after nailing of femoral shaft fractures occurs in about 25% of cases. It can cause substantial functional problems. The lesser trochanter (LT) profile has been used to assess rotational alignment. However, the extent to which the LT profile is symmetrical between limbs, whether the LT profile varies as a function of age or sex, and the efficacy of the LT profile technique remain unknown. The purpose of this study was to determine if there was a significant side-to-side length difference in the LT profile (LTD) according to age and sex. METHODS: We attempted to determine the amount of medial prominence of the lesser trochanter relative to the medial cortex of the femoral shaft (the LT profile) using 3-dimensional computed tomography (3D-CT) images of normal femora obtained bilaterally (366 subjects) in anatomic positions. We also compared the left and right sides to determine the amount of natural asymmetry by age and sex. In addition, we compared the side-to-side difference in the LT version with the LTD to determine whether the LTD represented the difference in femoral rotation. RESULTS: The LTD was <4 mm (meaning an LT version difference of <10°) in 83% of the subjects, but was ≥4 mm (an LT version difference of ≥10°) in 17%. Subset analysis demonstrated that the differences were greatest in women >70 years of age. The largest LTD (both sexes) was observed in individuals over 70 years of age (2.62 ± 1.37 mm, compared with <55 years: 1.55 ± 1.36 mm and 55 to 70 years: 2.27 ± 1.70 mm). There was no significant difference between sexes in the under-70 age groups. However, the LTD was significantly greater in women over 70 years than in men over 70 years (3.10 ± 1.42 versus 2.41 ± 1.30 mm). CONCLUSIONS: Since the LTD demonstrated side-to-side symmetry within 4 mm, or 10° of rotation, in 83% of all subjects, we consider the LT profile to be useful as a guide to assess rotational reduction clinically. However, surgeons should recognize that, in 17% of cases, using this technique could result in malrotation of ≥10°. The rate of malrotation may be even higher in women over 70, for whom supplemental techniques to ensure correct rotation may be appropriate.

Prediction of Long Bone Fractures in Multiple Myeloma Patients in an Advanced Imaging World.

BACKGROUND: Multiple myeloma (MM) affects the long bones in 25% of patients. The advent of positron-emission tomography/computed tomography (PET/CT) scanners offers the possibility of both metabolic and radiographic information and may help determine fracture risk. To the best of our knowledge, no published study correlates these two factors with long bone fractures. OBJECTIVES: To evaluate the impact of PET/CT on fracture risk assessment in multiple myeloma patients. METHODS: We identified all bone marrow biopsy proven multiple myeloma patients from 1 January 2010 to 31 January 2015 at a single institution. We prospectively followed patients with long bone lesions using PET/CT scan images. RESULTS: We identified 119 patients (59 males/60 females) with 256 long bone lesions. Mean age at diagnosis was 58 years. The majority of lesions were in the femur (n=150, 59%) and humerus (n=84, 33%); 13 lesions in 10 patients (8%) required surgery for impending (n=4) or actual fracture (n=9). Higher median SUVmax was measured for those with cortical involvement (8.05, range 0-50.8) vs. no involvement (5.0, range 2.1-18.1). SUVmax was found to be a predictor of cortical involvement (odds ratio = 1.17, P = 0.026). No significant correlation was found between SUVmax and pain or fracture (P = 0.43). CONCLUSIONS: Improved medical treatment resulted improvement in 8% of patients with an actual or impending fracture. The orthopedic surgeons commonly use the Mirels classification for long bone fracture prediction. Adding PET/CT imaging to study in myeloma long bone lesions did not predict fracture risk directly but suggested it indirectly by cortical erosion.

Correlation between lag screw route and the ideal insertion point of the intramedullary nail.

Understanding the morphology of the superior aspect of the proximal femur is critical for treating femoral fracture. We assessed the correlation among the ideal insertion point of the femoral nail, femur head-neck axis, and native anteversion. One hundred patients with normal femurs were included in this study. Computed tomography (CT) images of the proximal femur superior aspect and amount of native anteversion were acquired. Generalised Procrustes analysis showed the morphological characteristics of the superior proximal femur according to native anteversion amount. Morphological characteristics were represented by 4 parameters; the correlation between parameters and native anteversion was investigated using CT data. The passing point of the line from the proximal femoral canal parallel to the native anteversion at the greater trochanter was located more posteriorly (mean 35.6%); the passing point of native anteversion was posterior in the femoral neck and head, although the line of the head-neck centre passed more anteriorly at the greater trochanter (mean 67.5%). This posterior translation was significantly associated with native anteversion amount. Morphometric geometric analysis showed that the lag screw could not pass head-neck centre from the nail inserted into proximal femoral canal. Anterior insertion of the nail was needed for positioning the lag screw centre.

Dual-construct fixation is recommended in ipsilateral femoral neck fractures with infra-isthmus shaft fracture: A STROBE compliant study.

ABSTRACT: The aim of this study was to evaluate the risk factors related to osteosynthesis failure in patients with concomitant ipsilateral femoral neck and shaft fractures, including old age; smoking habit; comminuted fragments; infra-isthmus fracture; angular malreduction; unsatisfactory reduction (fracture gap >5 mm); and treatment with single construct.Patients over the age of 20 with concomitant ipsilateral femoral neck and shaft fractures diagnosed at a level one medical center between 2003 and 2019 were included. Treatment modalities included single construct with/without an antirotational screw for the neck and dual constructs. Radiographic outcomes were assessed from anteroposterior and lateral hip radiographs at follow-up. Fisher exact test was used to analyze categorical variables. The presence of avascular necrosis of the femoral head, delayed union, atrophic or hypertrophic nonunion of the femoral shaft fracture, and loss of reduction were identified as factors related to treatment failure.A total of 22 patients were included in this study. The average age was 58.5 years, and the majority was male (68.2%). The minimum radiographic follow-up duration was 12 months, and the median follow-up time was 12 (interquartile range 12-24) months.Femoral neck osteosynthesis failed in 3 patients, whereas femoral shaft osteosynthesis failed in 12 patients. Fisher exact test demonstrated the failure of femoral shaft osteosynthesis was significantly more frequent in the single-construct cohort in 16 infra-isthmus femoral fracture cases (P = .034).In ipsilateral femoral neck and infra-isthmus shaft fractures, it is better to treat the neck and shaft fractures with separate implants (dual constructs).In a dual-construct cohort, separate plate fixation of the femoral shaft achieved a better result in terms of bone union than retrograde nailing of the shaft (bone union rate: 4/8 vs 0/2).

Risk factors for refracture of the femoral shaft in children after removal of external fixation.

BACKGROUND: External fixation is the primary treatment option in children for femoral shaft fractures, such as open femoral or multiple fractures. One complication is refracture, which is the biggest limitation of fixation devices. This study aims to investigate the risk factors associated with refracture after the removal of external fixation devices and decrease the frequency of refracture. MATERIALS AND METHODS: Retrospectively reviewed clinical data of 165 patients treated at our hospital for fresh femoral shaft fractures with external fixation between May 2009 and February 2018 were included in this study. Patients with pathological fractures, fractures of the femoral neck, fractures that were fixed using plates or elastic stable intramedullary nailing, and old fractures, as well as those who underwent postoperative femoral surgery were excluded. Potential risk factors included: patient age, gender, and weight, fracture sides, open or closed fracture, fracture sites, reduction methods, operation time, perioperative bleeding, number and diameter of the screws, and immobilization time. These factors were identified by univariate and logistic regression analyses. RESULTS: Femoral shaft refracture developed in 24 patients. Univariate analysis revealed that refracture was not statistically significantly associated with any of the above factors, except AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) classification type 32-D/4.2 and L2/L3 ratio (L2, length of femur fixed by the two screws farthest from the fracture line; L3, the total length from the greater trochanter to the distal end of femur; P < 0.001 and P = 0.0141, respectively). Multivariate analysis showed that PCCF classification type 32-D/4.2 and L2/L3 ratio were also independent risk factors for femoral refracture. CONCLUSIONS: Femoral shaft refracture is relatively common in children treated with external fixation. Because of the limited number of cases in this study, we cautiously concluded that the PCCF classification type 32-D/4.2 and L2/L3 ratio were independent risk factors for femoral shaft refracture in these patients. LEVEL OF EVIDENCE: IV.

Epidemiology and mortality of pelvic and femur fractures-a nationwide register study of 417,840 fractures in Sweden across 16 years: diverging trends for potentially lethal fractures.

Background and purpose - Fractures of the pelvis and femur are serious and potentially lethal injuries affecting primarily older, but also younger individuals. Long-term trends on incidence rates and mortality might diverge for these fractures, and few studies compare trends within a complete adult population. We investigated and compared incidence and mortality rates of pelvic, hip, femur shaft, and distal femur fractures in the Swedish adult population.Patients and methods - We analyzed data on all adult patients ≥ 18 years in Sweden with a pelvic, hip, femur shaft, or distal femur fracture, through the Swedish National Patient Register. The studied variables were fracture type, age, sex, and 1-year mortality.Results - While incidence rates for hip fracture decreased by 18% (from 280 to 229 per 105 person-years) from 2001 to 2016, incidence rates for pelvic fracture increased by 25% (from 64 to 80 per 105 person-years). Incidence rates for femur shaft and distal femur fracture remained stable at rates of 15 and 13 per 105 person-years respectively. 1-year mortality after hip fracture was 25%, i.e., higher than for pelvic, femur shaft, and distal femur fracture where mortality rates were 20-21%. Females had an almost 30% lower risk of death within 1 year after hip fracture compared with males.Interpretation - Trends on fracture incidence for pelvic and femur fractures diverged considerably in Sweden between 2001 and 2016. While incidence rates for femur fractures (hip, femur shaft, and distal femur) decreased or remained constant during the studied years, pelvic fracture incidence increased. Mortality rates were different between the fractures, with the highest mortality among patients with hip fracture.

Progression of Asymptomatic Contralateral Femur in Patients with Complete Atypical Femoral Fracture, According to Initial Radiographic Findings.

BACKGROUND: Atypical femoral fracture (AFF) is associated with high prevalence rates of prodromal symptoms, bilateral involvement, complications, and the need for prophylactic fixation due to a risk of an impending fracture. Although most complete AFF cases have an asymptomatic contralateral femur at the initial presentation, there is lack of clarity on its progression. We evaluated the radiographic progression of asymptomatic contralateral femora in patients with a complete AFF and investigated the characteristics of these patients. METHODS: The medical records of 80 consecutive patients who had been treated for a complete AFF were retrospectively evaluated. We excluded 14 patients who had been lost to follow-up, 10 whose contralateral femur initially had been symptomatic and had been treated simultaneously, and 3 whose contralateral femur had previously been treated surgically. The remaining 53 patients were all women with an average age of 71.8 years. The average duration of bisphosphonate (BP) use was 63.6 months, and the mean follow-up duration was 48.9 months. All of the contralateral femora were asymptomatic and were divided into 2 grades according to the initial radiographic findings. We evaluated the prevalence of radiographic progression according to the grades and compared patient characteristics between the progression and non-progression groups. RESULTS: Radiographic progression was noted in 18 patients (34%) during the follow-up: 3 (12%) of 25 in grade 1 and 15 (53.6%) of 28 in grade 2 (p < 0.001). The mean time to progression for these 18 patients was 25.6 months, which also differed significantly depending on the grade (p = 0.02). Eleven and 9 (61.1% and 25.7%) of the patients received BP postoperatively in the progression and non-progression groups, respectively (p = 0.01). CONCLUSIONS: The prevalence of radiographic progression was relatively high, even though the contralateral femur was initially asymptomatic, and differed significantly according to the initial radiographic grade. The frequency of postoperative BP use was significantly higher in the progression group. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Investigation of femur fracture potential in common pediatric falls using finite element analysis.

A finite element (FE) model of an 11-month-old child's femur was developed to evaluate fracture risk in short-distance feet-first falls and bed falls. Pediatric material properties were applied to the FE model. Femur loading was derived from previously conducted fall experiments using a child surrogate where fall conditions (e.g., fall height, impact surface) were varied. Fracture thresholds based on principal stress and strain were used to examine potential for fracture. Peak stress/strain were significantly greater for feet-first falls from greater heights and onto harder impact surfaces. Feet-first falls exceeded some, but not all fracture thresholds. Bed falls did not exceed any fracture thresholds.

Grade 4 Distal Femur Stress Fracture in a Long-Distance Hiker on the Appalachian Trail.

Although stress injuries are a common occurrence in sports medicine clinics, a distal femur stress fracture is less so. Early detection can result in a favorable prognosis and may prevent the need for surgical intervention. A misdiagnosis resulting in delay of care can result in significant complications. This case report documents a rare distal femur stress fracture in a long-distance hiker. A 35-y-old male presented to an orthopedic clinic in Pennsylvania with left knee pain after completing 1423 km (884 mi) of the Appalachian trail over a 4-mo period. He was attempting a thru-hike, a specialized type of backpacking focused on completing a trail from end-to-end. Thru-hiking of this trail involves backpacking between Georgia and Maine, covering about 3540 km (2200 mi) with approximately 141,580 m (464,500 ft) of gain/loss in elevation. His pain began 2 mo into his hike when he noted medial sided left knee discomfort. Over the following 2 mo he sought treatment at 2 different locations along the trail with etiology undetermined. Upon evaluation in Pennsylvania, history and physical exam were suggestive of a stress fracture. Radiologic studies confirmed a closed nondisplaced nonangulated grade 4 transverse fracture of the shaft of the distal left femur. The patient was instructed to terminate his hike immediately and he was placed on nonweight bearing status. This case illustrates the importance of considering a distal femur stress fracture for the differential diagnosis of persistent knee pain in a long-distance hiker.

Musculoskeletal Trauma in Critically Injured Patients: Factors Leading to Delayed Operative Fixation and Multiple Organ Failure.

BACKGROUND: Musculoskeletal injuries are common following trauma and variables that are associated with late femur fracture fixation are important to perioperative management. Furthermore, the association of late fracture fixation and multiple organ failure (MOF) is not well defined. METHODS: We performed a retrospective cohort investigation from 2 academic trauma centers. INCLUSION CRITERIA: age 18-89 years, injury severity score (ISS) >15, femoral shaft fracture requiring operative fixation, and admission to the intensive care unit >2 days. Admission physiology variables and abbreviated injury scale (AIS) scores were obtained. Lactate was collected as a marker of shock and was described as admission lactate (LacAdm) and as 24-hour time-weighted lactate (LacTW24h), which reflects an area under the curve and is considered a marker for the overall depth of shock. The primary aim was to evaluate clinical variables associated with late femur fracture fixation (defined as ≥24 hours after admission). A multivariable logistic regression model tested variables associated with late fixation and is reported by odds ratio (OR) with 95% confidence interval (CI). The secondary aim evaluated the association between late fixation and MOF, defined by the Denver MOF score. The summation of scores (on a scale from 0 to 3) from the cardiac, pulmonary, hepatic, and renal systems was calculated and MOF was confirmed if the total daily sum of the worst scores from each organ system was >3. We assessed the association between late fixation and MOF using a Cox proportional hazards model adjusted for confounding variables by inverse probability weighting (a propensity score method). A P value <.05 was considered statistically significant. RESULTS: One hundred sixty of 279 (57.3%) patients received early fixation and 119 of 279 (42.7%) received late fixation. LacTW24h (OR = 1.66 per 1 mmol/L increase, 95% CI, 1.24-2.21; P < .001) and ISS (OR = 1.07 per 1-point increase, 95% CI, 1.03-1.10; P < .001) were associated with higher odds of late fixation. Late fixation was associated with a 3-fold increase in the odds of MOF (hazard ratio [HR] = 3.21, 95% CI, 1.48-7.00; P < .01). CONCLUSIONS: In a cohort of multisystem trauma patients with femur fractures, greater injury severity and depth of shock, as measured by LacTW24h, were associated with late operative fixation. Late fixation was also associated with MOF. Strategies to reduce the burden of MOF in this population require further investigation.

Atypical femoral fracture associated with delayed union for which the cessation of alendronate and daily administration of teriparatide contributed to fracture healing: histopathological evidence of the enhancement in bone formation parameters.

A female patient with systemic lupus erythematosus developed an atypical femoral fracture of the left femur after 5 years of glucocorticoid and alendronate therapy. We performed intramedullary nailing. However, 1 week later, we performed a revision surgery using a locking plate and an iliac bone graft because of displacement at the fracture site. At this stage, alendronate was discontinued and daily teriparatide was introduced and continued for 24 months. Twenty months after the revision surgery, a re-revision surgery was performed with an iliac bone graft because of breakage of the locking plate and fracture non-union. Fracture healing was eventually obtained 15 months after the re-revision surgery. Biopsies of the ilium before the treatment and 20 months after daily teriparatide treatment were evaluated. The histology revealed that proliferating osteoid and cuboidal osteoblasts were detected around the osteoid tissue after teriparatide treatment. Bone histomorphometry findings showed that bone volume parameters and osteoid parameters prominently increased with the teriparatide treatment, but not bone resorption parameters. Laboratory findings revealed the elevation of bone-specific alkaline phosphatase (24 U/L at 7 months) compared to its pre-teriparatide level (8.1 U/L) and increased bone mineral density of the hip (from -0.2 to 0.0 in T-score). These data indicated that the discontinuation of alendronate and initiation of teriparatide treatment activated bone-forming ability in our patient and may have contributed to fracture healing.