Periprosthetic fractures are fractures that occur in association with an orthopaedic implant, most often used for joint arthroplasty or fracture fixation. They are associated with significant morbidity and increased mortality in some cases. The incidence of periprosthetic fractures appears to be increasing as a result of increasing patient longevity, more demanding activity levels that persist into advanced age for some patients, and as a result of the increasing rate of revision arthroplasty which accompanies increasing patient longevity. Implant, surgeon, and patient factors all contribute to the risk of periprosthetic fracture. In this review, we intend to discuss current trends in periprosthetic fractures and risk factors associated with their development in the joint arthroplasty and fracture patient.

Although nonunions are among the most common complications after long-bone fracture fixation, the definition of fracture nonunion remains controversial and varies widely. The aim of this study was to identify the definitions and diagnostic criteria used in the scientific literature to describe nonunions after long-bone fractures. A comprehensive literature search was performed in PubMed, Cochrane Library, Web of Science, and Embase. Prospective clinical studies, in which adult long-bone fracture nonunions were investigated as main subject, were included in this analysis. Data on nonunion definitions described in each study were extracted and collected in a database. Although 148 studies met the inclusion criteria, only 50% (74/148) provided a definition for their main study subject. Nonunion was defined in these studies based on time-related criteria in 85% (63/74), on radiographic criteria in 62% (46/74), and on clinical criteria in 45% (33/74). A combination of clinical, radiographic and time-related criteria for definition was found in 38% (28/74). The time interval between fracture and the time point when authors defined an unhealed fracture as a nonunion showed considerable heterogeneity, ranging from three to twelve months. In the current orthopaedic literature, we found a lack of consensus with regard to the definition of long-bone nonunions. Without valid and reliable definition criteria for nonunion, standardization of diagnostic and treatment algorithms as well as the comparison of clinical studies remains problematic. The lack of a clear definition emphasizes the need for a consensus-based approach to the diagnosis of fracture nonunion centred on clinical, radiographical and time-related criteria.

The objective of this 3-year retrospective, controlled, cohort study is to characterize an interdisciplinary method of managing geriatric patients with hip fracture. All patients aged 65 years or older admitted to a single academic level I trauma center during a 3-year period with an isolated hip fracture were included as participants for this study. Thirty-one geriatric patients with hip fracture were treated with historical methods of care (cohort 1). The comparison group of 115 similar patients was treated under a newly developed, institutional comanagement hip fracture protocol (cohort 2). There were no differences in age, sex distribution, or comorbidity distribution between the 2 cohorts. Patients requiring intensive care unit (ICU) admission decreased significantly from 48% in cohort 1 to 23% in cohort 2 (P = .0091). Length of ICU stay for patients requiring ICU admission also decreased significantly, from a mean of 8.1 days in cohort 1 to 1.8 days in cohort 2 (P = .024). Total hospital stay decreased significantly, from a mean of 9.9 days in cohort 1 to 7.1 days in cohort 2 (P = .021). Although no decrease in in-hospital mortality rates was noted from cohort 1 to cohort 2, a trend toward decreased 1-year mortality rates was seen after implementation of the hip fracture protocol. Hospital charges decreased significantly, from US$52 323 per patient in cohort 1 to US$38 586 in cohort 2 (P = .0183). Implementation of a comanagement protocol for care of geriatric patients with hip fracture, consisting of admission to a geriatric primary care service, standardized perioperative assessment regimens, expeditious surgical treatment, and continued primary geriatric care postoperatively, resulted in reductions in lengths of stay, ICU admissions, and hospital costs per patient. On an annualized basis, this represented a savings of over US$700 000 for our institution.

Fracture nonunion risk is related to severity of injury and type of treatment, yet fracture healing is not fully explained by these factors alone. We hypothesize that patient demographic factors assessable by the clinician at fracture presentation can predict nonunion. A prospective cohort study design was used to examine ~2.5 million Medicare patients nationwide. Patients making fracture claims in the 5% Medicare Standard Analytic Files in 2011 were analyzed; continuous enrollment for 12months after fracture was required to capture the ICD-9-CM nonunion diagnosis code (733.82) or any procedure codes for nonunion repair. A stepwise regression analysis was used which dropped variables from analysis if they did not contribute sufficient explanatory power. In-sample predictive accuracy was assessed using a receiver operating characteristic (ROC) curve approach, and an out-of-sample comparison was drawn from the 2012 Medicare 5% SAF files. Overall, 47,437 Medicare patients had 56,492 fractures and 2.5% of fractures were nonunion. Patients with healed fracture (age 75.0±12.7SD) were older (p<0.0001) than patients with nonunion (age 69.2±13.4SD). The death rate among all Medicare beneficiaries was 4.8% per year, but fracture patients had an age- and sex-adjusted death rate of 11.0% (p<0.0001). Patients with fracture in 14 of 18 bones were significantly more likely to die within one year of fracture (p<0.0001). Stepwise regression yielded a predictive nonunion model with 26 significant explanatory variables (all, p≤0.003). Strength of this model was assessed using an area under the curve (AUC) calculation, and out-of-sample AUC=0.710. A logistic model predicted nonunion with reasonable accuracy (AUC=0.725). Within the Medicare population, nonunion patients were younger than patients who healed normally. Fracture was associated with increased risk of death within 1year of fracture (p<0.0001) in 14 different bones, confirming that geriatric fracture is a major public health issue. Comorbidities associated with increased risk of nonunion include past or current smoking, alcoholism, obesity or morbid obesity, osteoarthritis, rheumatoid arthritis, type II diabetes, and/or open fracture (all, multivariate p<0.001). Nonunion prediction requires knowledge of 26 patient variables but predictive accuracy is currently comparable to the Framingham cardiovascular risk prediction.

Established fracture nonunions rarely heal without secondary intervention. Revision surgery is the most common intervention, though non-surgical options for nonunion would be useful if they could overcome nonunion risk factors. Our hypothesis is that low-intensity pulsed ultrasound (LIPUS) can enhance heal rate (HR) in fractures that remain nonunion after one year, relative to the expected HR in the absence of treatment, which is expected to be negligible. We collated outcomes from a prospective patient registry required by the U.S. Food & Drug Administration. Patient data were collected over a 4-year period beginning in 1994 and were individually reviewed and validated by a registered nurse. Patients were only included if they had four data points available: date when fracture occurred; date when LIPUS treatment began; date when LIPUS treatment ended; and a dichotomous outcome of healed vs. failed, assessed by clinical and radiological criteria. Data were used to calculate two derived variables: days to treatment (DTT) with LIPUS, and days on treatment (DOT) with LIPUS. Every validated chronic nonunion patient (DTT>365 days) with complete data is reported. Heal rate for chronic nonunion patients (N=767) treated with LIPUS was 86.2%. Heal rate was 82.7% among 98 patients with chronic nonunion ≥5 years duration, and 12 patients healed after chronic nonunion >10 years (HR=63.2%). There was more patient loss to follow-up, non-compliance, and withdrawal, comparing chronic nonunion patients to all other patients (p10 years. LIPUS resulted in successful healing in the majority of nonunions without further surgical intervention.

Patient age is one of many potential risk factors for fracture nonunion. Our hypothesis is that older patients (≥60) with fracture risk factors treated with low-intensity pulsed ultrasound (LIPUS) have similar heal rate (HR) to the population as a whole. We evaluate the impact of age in conjunction with other risk factors on HR in LIPUS-treated patients with fresh fracture (≤90 days old). The Exogen Bone Healing System is a LIPUS device approved in 1994 to accelerate healing of fresh fracture. After approval, the FDA required a Post-Market Registry to assess performance. Patient data collected from October 1994 until October 1998 were individually reviewed and validated by a registered nurse. Four distinct data elements were required to report a patient: date fracture occurred; date treatment began; date treatment ended; and a dichotomous outcome of healed v. failed, by clinical and radiological criteria. Data were used to calculate two derived variables; days to treatment (DTT) and days on treatment (DOT). Every validated fresh fracture patient with DTT, DOT, and outcome is reported. The validated registry had 5,765 patients with fresh fracture; 73% (N = 4,190) are reported, while 13% of patients were lost to follow-up, 11% withdrew or were non-compliant, and 3% died or are missing outcome. Among treatment-compliant patients, HR was 96.2%. Logistic estimates of the odds ratio for healing are equivalent for patients age 30 to 79 years and all age cohorts had a HR > 94%. Open fracture, current smoking, diabetes, vascular insufficiency, osteoporosis, cancer, rheumatoid arthritis, and prescription NSAIDs all reduced HR, but older patients (≥60) had similar HRs to the population as a whole. DTT was significantly shorter for patients who healed (p < 0.0001). Comorbid conditions in conjunction with aging can reduce fracture HR. Patients with fracture who used LIPUS had a 96% HR, whereas the expected HR averages 93%. Time to treatment was significantly shorter among patients who healed (p < 0.0001), suggesting that it is beneficial to begin LIPUS treatment early. Older patients (≥60) with fracture risk factors treated with LIPUS exhibit similar heal rates to the population as a whole.