Faculty Bibliography

BACKGROUND: Bisphosphonate therapy for osteoporosis has been associated with atypical femoral fractures. To date, there have been few reports in the literature regarding the preoperative and postoperative courses of patients who have sustained bisphosphonate-associated complete atypical femur fractures. OBJECTIVES/PURPOSES: The purposes of this study were to (1) characterize the preoperative course of patients who eventually presented with bisphosphonate-associated complete atypical femur fractures (duration of bisphosphonate treatment, pain history, risk of converting a nondisplaced fracture to a complete fracture); (2) evaluate the percentage of patients who achieved radiographic union of those fractures after treatment; and (3) determine the patients' recovery of function using the Short Musculoskeletal Functional Assessment. METHODS: Thirty-three patients with 41 atypical, low-energy femur fractures associated with >/= 5 years of bisphosphonate use were treated with intramedullary nailing between 2004 and 2011 at one center. The main outcome measurements were Short Musculoskeletal Functional Assessment for function and radiographic evaluation for fracture healing. Patients had been treated with bisphosphonates for an average of 8.8 years (range, 5-20 years) before presentation. RESULTS: Patients reported a mean of 6 months of pain before presentation (range, 1-8 months). Sixty-six percent of patients with surgically treated complete fractures became pain-free and 98% were radiographically healed by 12 months. Sixty-four percent of patients who underwent intramedullary nailing reported a functional return to baseline within 1 year. Patients who reported major functional limitations at latest followup listed pain and apprehension as the major causes of their limitation. CONCLUSIONS: Patients with surgically treated bisphosphonate-associated complete femur fractures achieved generally reliable although delayed fracture healing if malaligned, and nearly two-thirds of patients returned to self-reported baseline function within 1 year. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

In March 2012, an algorithm for the treatment of intertrochanteric fractures of the hip was introduced in our academic department of Orthopaedic Surgery. It included the use of specified implants for particular patterns of fracture. In this cohort study, 102 consecutive patients presenting with an intertrochanteric fracture were followed prospectively (post-algorithm group). Another 117 consecutive patients who had been treated immediately prior to the implementation of the algorithm were identified retrospectively as a control group (pre-algorithm group). The total cost of the implants prior to implementation of the algorithm was $357 457 (mean: $3055 (1947 to 4133)); compared with $255 120 (mean: $2501 (1052 to 4133)) after its implementation. There was a trend toward fewer complications in patients who were treated using the algorithm (33% pre- versus 22.5% post-algorithm; p = 0.088). Application of the algorithm to the pre-algorithm group revealed a potential overall cost saving of $70 295. The implementation of an evidence-based algorithm for the treatment of intertrochanteric fractures reduced costs while maintaining quality of care with a lower rate of complications and re-admissions. Cite this article: Bone Joint J 2014;96-B:1192-7.

INTRODUCTION: Elderly patients are at risk of fracture nonunion, given the potential setting of osteopenia, poorer fracture biology, and comorbid medical conditions. Risk factors predicting fracture nonunion may compromise the success of fracture nonunion surgery. The purpose of this study was to investigate the effect of patient age on clinical and functional outcome following long bone fracture nonunion surgery. MATERIALS AND METHODS: A retrospective analysis of prospectively collected data identified 288 patients (aged 18-91) who were indicated for long bone nonunion surgery. Two-hundred and seventy-two patients satisfied study inclusion criteria and analyses were performed comparing elderly patients aged >/=65 years (n = 48) with patients <65 years (n = 224) for postoperative wound complications, Short Musculoskeletal Functional Assessment (SMFA) functional status, healing, and surgical revision. Regression analyses were performed to look for associations between age, smoking status, and history of previous nonunion surgery with healing and functional outcome. Twelve-month follow-up was obtained on 91.5% (249 of 272) of patients. RESULTS: Despite demographic differences in the aged population, including a predominance of medical comorbidities (P < .01) and osteopenia (P = .02), there was no statistical differences in the healing rate of elderly patients (95.8% vs 95.1%, P = .6) or time to union (6.2 +/- 4.1 months vs. 7.2 +/- 6.6, P = .3). Rates of postoperative wound complications and surgical revision did not statistically differ. Elderly patients reported similar levels of function up to 12 months after surgery. Regression analyses failed to show any significant association between age and final union or time to union. There was a strong positive association between smoking and history of previous nonunion surgery with time to union. Age was associated (positively) with 12-month SMFA activity score. CONCLUSIONS: Smoking and failure of previous surgical intervention were associated with nonunion surgery outcomes. Patient's age at the time of surgery was not associated with achieving union. Advanced age was generally not associated with poorer nonunion surgery outcomes.

Background and aims: This study seeks to determine the effect of spinal anesthesia (SA) on clinical outcomes when compared to general anesthesia (GA) in operatively managed tibial plateau fractures. Methods: Over 8 years, all operative tibial plateau fractures treated by two surgeons were prospectively followed. 113 patients were identified for this study. 30 received SA and 83 received GA. All patients were treated using a similar operative protocol and physiotherapy regimen. Clinical outcomes were compared at 3 months, 6 months and the latest follow-up. These outcomes include Short Musculoskeletal Functional Assessment (SMFA) scores, pain levels, complications and reoperations. Analysis was done using student's t-tests, Chi-squared tests and multivariate linear regression. Results: Using univariate analysis, SMFA scores were improved at 6 months in SA vs. GA patients (beta = -1.14, 95% confidence interval [CI] = -2.06 to -.23, p=0.015), and pain scores were lower in SA vs. GA at 6 months (p =0.004) and at the latest followup (p=0.012). After controlling for group differences, pain scores were found to be lower in SA vs. GA at 3 months (beta = -0.16, 95% CI = -0.24 to 2.02, p=0.048), but not at 6 months or the latest followup. The odds ratio of higher pain scores of a patient who received GAvs SA at 3 months was 3.1 (95% CI, 1.06 to 9.26, p=0.039). Conclusions: In patients who undergo surgical management of a tibial plateau fracture, the use of spinal anesthesia is associated with improved functional scores and decreased pain levels up to 6 months postoperatively

Purpose To determine the feasibility of using finite element analysis applied to 3-T magnetic resonance (MR) images of proximal femur microarchitecture for detection of lower bone strength in subjects with fragility fractures compared with control subjects without fractures. Materials and Methods This prospective study was institutional review board approved and HIPAA compliant. Written informed consent was obtained. Postmenopausal women with (n = 22) and without (n = 22) fragility fractures were matched for age and body mass index. All subjects underwent standard dual-energy x-ray absorptiometry. Images of proximal femur microarchitecture were obtained by using a high-spatial-resolution three-dimensional fast low-angle shot sequence at 3 T. Finite element analysis was applied to compute elastic modulus as a measure of strength in the femoral head and neck, Ward triangle, greater trochanter, and intertrochanteric region. The Mann-Whitney test was used to compare bone mineral density T scores and elastic moduli between the groups. The relationship (R2) between elastic moduli and bone mineral density T scores was assessed. Results Patients with fractures showed lower elastic modulus than did control subjects in all proximal femur regions (femoral head, 8.51-8.73 GPa vs 9.32-9.67 GPa; P = .04; femoral neck, 3.11-3.72 GPa vs 4.39-4.82 GPa; P = .04; Ward triangle, 1.85-2.21 GPa vs 3.98-4.13 GPa; P = .04; intertrochanteric region, 1.62-2.18 GPa vs 3.86-4.47 GPa; P = .006-.007; greater trochanter, 0.65-1.21 GPa vs 1.96-2.62 GPa; P = .01-.02), but no differences in bone mineral density T scores. There were weak relationships between elastic moduli and bone mineral density T scores in patients with fractures (R2 = 0.25-0.31, P = .02-.04), but not in control subjects. Conclusion Finite element analysis applied to high-spatial-resolution 3-T MR images of proximal femur microarchitecture can allow detection of lower elastic modulus, a marker of bone strength, in subjects with fragility fractures compared with control subjects. MR assessment of proximal femur strength may provide information about bone quality that is not provided by dual-energy x-ray absorptiometry. (c) RSNA, 2014.

PURPOSE: High-resolution imaging of deeper anatomy such as the hip is challenging due to low signal-to-noise ratio (SNR), necessitating long scan times. Multi-element coils can increase SNR and reduce scan time through parallel imaging (PI). We assessed the feasibility of using a 26-element receive coil setup to perform 3 Tesla (T) MRI of proximal femur microarchitecture without and with PI. MATERIALS AND METHODS: This study had institutional review board approval. We scanned 13 subjects on a 3T scanner using 26 receive-elements and a three-dimensional fast low-angle shot (FLASH) sequence without and with PI (acceleration factors [AF] 2, 3, 4). We assessed SNR, depiction of individual trabeculae, PI performance (1/g-factor), and image quality with PI (1 = nonvisualization to 5 = excellent). RESULTS: SNR maps demonstrate higher SNR for the 26-element setup compared with a 12-element setup for hip MRI. Without PI, individual proximal femur trabeculae were well-depicted, including microarchitectural deterioration in osteoporotic subjects. With PI, 1/g values for the 26-element/12-element receive-setup were 0.71/0.45, 0.56/0.25, and 0.44/0.08 at AF2, AF3, and AF4, respectively. Image quality was: AF1, excellent (4.8 +/- 0.4); AF2, good (4.2 +/- 1.0); AF3, average (3.3 +/- 1.0); AF4, nonvisualization (1.4 +/- 0.9). CONCLUSION: A 26-element receive-setup permits 3T MRI of proximal femur microarchitecture with good image quality up to PI AF2. J. Magn. Reson. Imaging 2014;40:229-238. (c) 2013 Wiley Periodicals, Inc.

PURPOSE: To demonstrate the feasibility of performing bone microarchitecture, high-resolution cartilage, and clinical imaging of the hip at 7T. MATERIALS AND METHODS: This study had Institutional Review Board approval. Using an 8-channel coil constructed in-house, we imaged the hips of 15 subjects on a 7T magnetic resonance imaging (MRI) scanner. We applied: 1) a T1-weighted 3D fast low angle shot (3D FLASH) sequence (0.23 x 0.23 x 1-1.5 mm3 ) for bone microarchitecture imaging; 2) T1-weighted 3D FLASH (water excitation) and volumetric interpolated breath-hold examination (VIBE) sequences (0.23 x 0.23 x 1.5 mm3 ) with saturation or inversion recovery-based fat suppression for cartilage imaging; 3) 2D intermediate-weighted fast spin-echo (FSE) sequences without and with fat saturation (0.27 x 0.27 x 2 mm) for clinical imaging. RESULTS: Bone microarchitecture images allowed visualization of individual trabeculae within the proximal femur. Cartilage was well visualized and fat was well suppressed on FLASH and VIBE sequences. FSE sequences allowed visualization of cartilage, the labrum (including cartilage and labral pathology), joint capsule, and tendons. CONCLUSION: This is the first study to demonstrate the feasibility of performing a clinically comprehensive hip MRI protocol at 7T, including high-resolution imaging of bone microarchitecture and cartilage, as well as clinical imaging. J. Magn. Reson. Imaging 2013;. (c) 2013 Wiley Periodicals, Inc.

The benefits of bisphosphonates are well documented, but prolonged use has been associated with atypical femur fractures. Radiographic markers for fracture predisposition could potentially aid in safer medication use. In this case-control designed study, we compared hip radiographic parameters and the demographic characteristics of chronic bisphosphonate users who sustained an atypical femoral fracture with a group of chronic bisphosphonate users who did not sustain an atypical femur fracture and also a group who sustained an intertrochanteric hip fracture. Radiographic parameters included were neck-shaft angle (NSA), hip-axis length (HAL) and center-edge angle (CE). Multivariate regression was used to evaluate the relationship between radiographic measures and femur fracture. Receiver-operating characteristic analysis determined cut-off points for neck-shaft angle and risk of atypical femur fracture. Ultimately, pre-fracture radiographs of 53 bisphosphonate users who developed atypical fracture were compared with 43 asymptomatic chronic bisphosphonate users and 64 intertrochanteric fracture patients. Duration of bisphosphonate use did not statistically differ between users sustaining atypical fracture and those without fracture (7.9 [+/-3.5] vs. 7.7 [+/-3.3] years, p=0.7). Bisphosphonate users who fractured had acute/varus pre-fracture neck-shaft angles (p<0.001), shorter hip-axis length (p<0.01), and narrower center-edge angles (p<0.01). Regression analysis revealed associations between neck-shaft angle (OR=0.89 [95% CI=0.81-0.97; p=0.01), center edge angle (OR=0.89 [95% CI=0.80-0.99]; p=0.03), and BMI (OR=1.15 [95% CI=1.02-1.31; p=0.03) with fracture development. ROC curve analysis (AUC=0.67 [95% CI=0.56-0.79]) determined that a cut-off point for neck-shaft angle <128.3 degrees yielded 69% sensitivity and 63% specificity for development of atypical femoral fracture. Ultimately, an acute/varus angle of the femoral neck, high BMI, and narrow center-edge angle were associated with development of atypical femur fracture in long-term bisphosphonate users. Patients on long-term bisphosphonates should be regularly radiographically evaluated in order to assess for potential risk of atypical fracture.

Bone morphogenetic proteins are a necessary component of the fracture healing cascade. Few studies have delineated the efficacy of iliac crest bone graft and recombinant human bone morphogenetic protein 2 (rhBMP-2), especially, in comparison with the gold standard treatment of nonunion, which is autogenous bone graft alone. This study compared the outcome of patients with fracture nonunion treated with autogenous bone graft plus rhBMP-2 adjuvant vs patients treated with autogenous bone graft alone. A total of 118 consecutive patients who were to undergo long bone nonunion surgery with autogenous bone graft (50) or autogenous bone graft plus rhBMP-2 (68) were identified. Surgical intervention included either harvested iliac autogenous bone graft or autogenous bone graft plus 1.5 mg/mL of rhBMP-2 placed in and around the site of nonunion. No differences were found in the distribution of nonunion sites included within each group. Twelve-month follow-up was obtained on 100 of 118 patients (84.7%). Analyses of demographic characteristics (including tobacco), medical comorbidities, previous surgeries, and nonunion type (atrophic vs hypertrophic) did not differ. Postoperative complication rates did not differ. The percentage of patients who progressed to union did not differ. Mean time to union in the autogenous bone graft plus rhBMP-2 group was 6.6 months (+/-3.9) vs 5.4 (+/-2.7) months in the autogenous bone graft-only group (P=.06). Rates of revision (16.2% for rhBMP-2 plus autogenous bone graft vs 8% for autogenous bone graft) did not differ statistically (P=.19), nor did 12-month scores of pain and functional assessment. Although rhBMP-2 is a safe adjuvant, there was no benefit seen when rhBMP-2 was added to autogenous bone graft in the treatment of long bone nonunion. Given its high cost, rhBMP-2 should be reconsidered as an aid to autogenous bone graft in the treatment of nonunion.

BACKGROUND: Prior studies have suggested that Asian patients and women may be more likely to sustain atypical femoral fractures in association with bisphosphonate use. However, they do not account for confounders such as asymptomatic patients who are long-term bisphosphonate users or patients sustaining osteoporotic fractures. QUESTIONS/PURPOSES: The purpose of this study was to determine the differences in sex and racial association with atypical femoral fractures by comparing demographic characteristics of patients who sustained an atypical bisphosphonate-associated fracture with patients on long-term bisphosphonates without fractures and with patients who sustained osteoporotic fractures. METHODS: Three groups from prospective registries were identified: (1) patients with atypical femur fractures associated with long-term bisphosphonate use (BFF) (n = 54); (2) patients on long-term bisphosphonates but with no associated fractures (BNF) (n = 119); and (3) patients with osteoporotic proximal femur fractures not associated with bisphosphonates (PFF) (n = 216). Age, sex, and self-reported race/ethnicity were documented and compared. Multivariate and univariate analyses were done as well as age- and sex-stratified analyses. RESULTS: Age and sex distributions of the BFF and BNF patients were similar. There was a higher percentage of Asian patients in the BFF group (17%) than in the BNF group (3%; p = 0.004) as well as Hispanics (13% versus 3% in BNF; p = 0.011). Patients in the BFF group were younger than those in the PFF group (67.5 versus 78.4 years; p < 0.001) and had fewer males (7% versus 14%; p < 0.001). CONCLUSIONS: These data suggest that Asians are at higher risk for atypical bisphosphonate-associated fractures. We recommend closer followup in Asian patients who are taking bisphosphonates. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.