Personal Finance Primer for the Future Orthopaedic Surgeon: A Starting Point.

The level of financial literacy varies among orthopaedic trainees. Personal finance ideally should be taught before accepting student loans; however, when this has not happened, it is imperative that trainees start taking their personal finances seriously. Many trainees are faced with large amounts of student debt and struggle with how to manage a large salary increase in their first job. This can lead to poor financial decisions including insufficient savings. The authors provide a comprehensive viewpoint on personal finance for the orthopaedic trainee. In this article, we provide future orthopaedic surgeons with a framework for personal financial management as a starting point to understanding the financial concepts of budgeting, investment, debt management, mortgage, disability insurance, and life insurance.

Does the Symmetry of Patellar Morphology Matter When Matching Osteochondral Allografts for Osteochondral Defects Involving the Central Ridge of the Patella?

OBJECTIVE: The purpose of this study was to determine if differences in Wiberg classification play a role in the ability of donor patellar osteochondral allografts to match the native patellar surface when treating osteochondral defects of the patellar apex. DESIGN: Twenty (10 Wiberg I and 10 Wiberg II/III) human patellae were designated as the recipient. Each recipient was size-matched to both a Wiberg I and a Wiberg II/III patellar donor. A 16-mm circular osteochondral "defect" was created on the central ridge of the recipient patella. The randomly ordered donor Wiberg I or Wiberg II/III plug was harvested from a homologous location and transplanted into the recipient. The recipient was then nano-CT (computed tomography) scanned, digitally reconstructed, registered to the initial nano-CT scan of the recipient patella, and processed to determine root mean squared circumferential step-off heights as well as surface height deviation. The process was then repeated for the other allograft plug. RESULTS: There was no significant difference in mean step-off height between matched and unmatched Wiberg plugs; however, there was a statistically significant difference in surface height deviation over the whole surface (0.50 mm and 0.64 mm respectively, P = 0.03). This difference of 0.14 mm is not felt to be clinically significant. Tibial width was correlated to patellar width (r = 0.82) and patellar height (r = 0.68). CONCLUSIONS: For osteochondral allograft sizes up to 16 mm there appears to be no advantage to match donor and recipient patellar morphology. Further study is warranted to evaluate defects requiring larger graft sizes.

Local and Systemic Effects of Blood Flow Restriction Therapy in an Animal Model.

BACKGROUND: Blood flow restriction therapy (BFRT) has been increasingly applied to improve athletic performance and injury recovery. Validation of BFRT has lagged behind commercialization, and currently the mechanism by which this therapy acts is unknown. BFRT is one type of ischemic therapy, which involves exercising with blood flow restriction. Repetitive restriction of muscle blood flow (RRMBF) is another ischemic therapy type, which does not include exercise. HYPOTHESIS/PURPOSE: The purpose was to develop a rat model of ischemic therapy, characterize changes to muscle contractility, and evaluate local and systemic biochemical and histologic responses of 2 ischemic therapy types. We hypothesized that ischemic therapy would improve muscle mass and strength as compared with the control group. STUDY DESIGN: Controlled laboratory study. METHODS: Four groups of 10 Sprague-Dawley rats were established: control, stimulation, RRMBF, and BFRT. One hindlimb of each subject underwent 8 treatment sessions over 4 weeks. To simulate exercise, the stimulation group underwent peroneal nerve stimulation for 2 minutes. The RRMBF group used a pneumatic cuff inflated to 100 mm Hg with a 48-minute protocol. The BFRT group involved 100-mm Hg pneumatic cuff inflation and peroneal nerve stimulation for a 5-minute protocol. Four methods of evaluation were performed: in vivo contractility testing, histology, immunohistochemistry, and ELISA. Analysis of variance with post hoc Tukey test and linear mixed effects modeling were used to compare the treatment groups. RESULTS: There was no difference in muscle mass among groups (P = .40) or between hindlimbs (P = .73). In vivo contractility testing showed no difference in maximum contractile force among groups (P = .64) or between hindlimbs (P = .30). On histology, myocyte cross-sectional area was not different among groups (P = .55) or between hindlimbs (P = .44). Pax7 immunohistochemistry demonstrated no difference in muscle satellite cell density among groups (P = .06) or between hindlimbs (P = .046). ELISA demonstrated the RRMBF group as eliciting elevated GH levels as compared with the other groups (P < .001). CONCLUSION: Ischemic therapy did not induce gains in muscle mass, contractility strength, fiber cross-sectional area, or satellite cell density locally or systemically in this model, although the RRMBF group did have elevated GH levels on ELISA. CLINICAL RELEVANCE: This animal model does not support ischemic therapy as a method to improve muscle mass, function, or satellite cell density.

Nonbiologic Injections in Sports Medicine.

Nonbiologic medications (local anesthetics, corticosteroids, and nonsteroidal anti-inflammatory drugs) are commonly administered to athletes for analgesia after injury. However, the risks of nonbiologic injections often are overlooked simply because of their long-term market availability. A thorough understanding of the mechanism of action, the reported benefits, and the potential risks of nonbiologic medications is crucial prior to their use, especially in the treatment of young athletes. Sports medicine physicians and surgeons must be aware of the systemic and local effects of these medications to ensure an appropriate drug choice that minimizes side effects and avoids recently reported toxicity to myocytes, tenocytes, and chondrocytes.

Applying Systems Engineering to Increase Operating Room Efficiency.

Systems engineering is an interdisciplinary approach to creating, evaluating, and managing a complex process in order to increase reliability, cost-effectiveness, and quality. The operating room is a complex environment that requires human-human interaction, human-device interaction, planning, and coordination of scarce resources for the purpose of providing surgery to patients in a safe and efficient manner. The operating room is an important revenue generator, but it can also be responsible for unsustainable costs if not managed effectively. Reducing costs and increasing the efficiency of surgical cases is important for generating health care value. Efficiency efforts that aim for standardization of surgical protocols must be balanced by flexibility in the unpredictable operating room environment. This paper reviews systems engineering efforts to improve efficiency in the operating room including operating room scheduling, personnel factors, resource management, orthopedicspecific initiatives, and future innovations.

Vault perforation after eccentric glenoid reaming for deformity correction in anatomic total shoulder arthroplasty.

BACKGROUND: The management of glenoid deformity during anatomic total shoulder arthroplasty remains controversial. In this study, we evaluate variable correction of glenoid deformity by eccentric reaming. We hypothesize that partial correction of modified Walch B/C-type glenoid deformities can achieve 75% bone-implant contact area (BICA) with a reduced vault perforation risk compared with complete correction. METHODS: Fifty shoulder computed tomographic scans with glenohumeral osteoarthritis were retrospectively evaluated. The Tornier BluePrint v2.1.5 software simulated 3 eccentric reaming scenarios including no, partial, and complete deformity correction. Each scenario was evaluated at 4 BICAs and using 3 implant fixation types. Three-dimensional surface representations were used to evaluate medialization and vault perforation. RESULTS: The patients had mean glenoid retroversion and inclination of 18.5° and 8.8°, respectively, and mean posterior humeral head subluxation of 76%. With 75% BICA, the 3 fixation types had glenoid vault perforation in 6%-26% and 26%-54% of cases for partial and complete glenoid deformity correction, respectively. The central and posterior-inferior implant components were most likely to perforate across all scenarios. DISCUSSION: Eccentric reaming for glenoid deformity correction increases the risk of vault perforation. Severe glenoid deformity required increased medialization to achieve 75% BICA. Pegged implants have increased chances of perforation compared with a keeled design; the central and posterior-inferior components were most likely to perforate during deformity correction. CONCLUSION: Partial deformity correction of modified Walch B/C-type glenoid deformities can achieve 75% BICA while reducing the risk of vault perforation compared with complete correction at the time of anatomic total shoulder arthroplasty.

Ischemic Therapy in Musculoskeletal Medicine.

BACKGROUND: The competitive environment of athletics has promoted the exploration of any technology application that may offer an edge with performance and recovery from injury. Ischemic therapy is one such technology that has rapidly been incorporated into training rooms and physical therapy clinics worldwide. This therapy modality is reported to increase an athlete's ability to improve muscle mass, strength, and endurance. PURPOSE: To provide the sports medicine physician with an understanding of the current state of ischemic therapy technology, including treatment specifications, known physiological effects, hypothesized mechanisms, biochemical effects, athletic applications, medical applications, animal models, and future research recommendations. STUDY DESIGN: Literature review. METHODS: A computer-based search of the PubMed database was used to perform a comprehensive literature review on musculoskeletal ischemic therapy. RESULTS: The current research on ischemic therapy is largely composed of case series with varying equipment, methods, and therapy specifications. The publication of case series has value in identifying this technology for future research, but the results of these studies should not be justification for application to athletes without validation of safety and effectiveness. CONCLUSION: To date, ischemic therapy remains unvalidated, and the mechanism by which it improves muscle performance is not clear.

Is the incidence of paediatric stress fractures on the rise? Trends in New York State from 2000 to 2015.

The purpose of this study is to analyze trends in the epidemiology of paediatric stress fractures. The New York Statewide Planning and Research Cooperative System database was queried for stress fractures in children between the ages of 6 and 18 years. After checking for monotonicity of the data, Spearman's correlation coefficient was calculated. Multivariate regressions were used to test for associations between demographic variables and risk of stress fracture. Analysis of 11 475 386 outpatient visits between 2000 and 2015 showed that the annual incidence of paediatric stress fractures increased from 1.37 cases per 100 000 outpatient visits in 2006 to 5.32 per 100 000 visits in 2015 (ρ = 0.876, P < 0.01). The mean age at the time of injury was 14.4 ± 2.8 years. Children younger than 14 years accounted for 33.6% of the cohort. Age, male sex, white ethnicity, and private insurance were statistically significant predictors of stress fractures in a multivariate model. This study is the first to document an increase in the annual incidence of paediatric stress fractures.

Surgical Versus Nonsurgical Management of Rotator Cuff Tears: A Matched-Pair Analysis.

BACKGROUND: Rotator cuff disease is a major medical and economic burden due to a growing aging population, but management of rotator cuff tears remains controversial. We hypothesized that there is no difference in outcomes between patients who undergo rotator cuff repair and matched patients treated nonoperatively. METHODS: After institutional review board approval, a prospective cohort of patients over 18 years of age who had a full-thickness rotator cuff tear seen on magnetic resonance imaging (MRI) were retrospectively evaluated. After clinical evaluation, each patient elected to undergo either rotator cuff repair or nonsurgical treatment. Demographic information was collected at enrollment, and self-reported outcome measures (the Normalized Western Ontario Rotator Cuff Index [WORCnorm], American Shoulder and Elbow Surgeons score [ASES], Single Assessment Numerical Evaluation [SANE], and pain score on a visual analog scale [VAS]) were collected at baseline and at 6, 12, and >24 months. The Functional Comorbidity Index (FCI) was used to assess health status at enrollment. The size and degree of atrophy of the rotator cuff tear were classified on MRI. Propensity score analysis was used to create rotator cuff repair and nonsurgical groups matched by age, sex, symptom duration, FCI, tear size, injury mechanism, and atrophy. The Student t test, chi-square test, and regression analysis were used to compare the treatment groups. RESULTS: One hundred and seven patients in each group were available for analysis after propensity score matching. There were no differences between the groups with regard to demographics or rotator cuff tear characteristics. For all outcome measures at the time of final follow-up, the rotator cuff repair group had significantly better outcomes than the nonsurgical treatment group (p < 0.001). At the time of final follow-up, the mean outcome scores (and 95% confidence interval) for the surgical repair and nonsurgical treatment groups were, respectively, 81.4 (76.9, 85.9) and 68.8 (63.7, 74.0) for the WORCnorm, 86.1 (82.4, 90.3) and 76.2 (72.4, 80.9) for the ASES, 77.5 (70.6, 82.5) and 66.9 (61.0, 72.2) for the SANE, and 14.4 (10.2, 20.2) and 27.8 (22.5, 33.5) for the pain VAS. In the longitudinal regression analysis, better outcomes were independently associated with younger age, shorter symptom duration, and rotator cuff repair. CONCLUSIONS: Patients with a full-thickness rotator cuff tear reported improvement in pain and functional outcome scores with nonoperative treatment or surgical repair. However, patients who were offered and chose rotator cuff repair reported greater improvement in outcome scores and reduced pain compared with those who chose nonoperative treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Arm Fasciotomy Through Lateral Approach.

Acute compartment syndrome represents one of the few true orthopaedic emergencies. Timely management is essential to prevent permanent sequelae. This video describes a case of acute compartment syndrome of the arm. Relevant patient history, physical examination, and laboratory findings are discussed, and a presentation of the operative technique for arm fasciotomy through a lateral approach is highlighted. Diagnostic criteria for acute compartment syndrome and indications for fasciotomy are reviewed, with a discussion of published outcomes after fasciotomy.

A Novel MRI Tool for Evaluating Cortical Bone Thickness of the Proximal Femur.

BACKGROUND: Osteoporotic hip fractures heavily cost the health care system. Clinicians and patients can benefit from improved tools to assess bone health. Herein, we aim to develop a three-dimensional magnetic resonance imaging (MRI) method to assess cortical bone thickness and assess the ability of the method to detect regional changes in the proximal femur. METHODS: Eighty-nine patients underwent hip magnetic resonance imaging. FireVoxel and 3DSlicer were used to generate three-dimensional proximal femur models. ParaView was used to define five regions: head, neck, greater trochanter, intertrochanteric region, and subtrochanteric region. Custom software was used to calculate the cortical bone thickness and generate a color map of the proximal femur. Mean cortical thickness values for each region were calculated. Statistical t-tests were performed to evaluate differences in cortical thickness based on proximal femur region. Measurement reliability was evaluated using coefficient of variation, intraclass correlation coefficients, and overlap metrics. RESULTS: Three-dimensional regional cortical thickness maps for all subjects were generated. The subtrochanteric region was found to have the thickest cortical bone and the femoral head had the thinnest cortical bone. There were statistically significant differences between regions (p < 0.01) for all possible comparisons. CONCLUSIONS: Cortical bone is an important contributor to bone strength, and its thinning results in increased hip fracture risk. We describe the development and measurement reproducibility of an MRI tool permitting assessment of proximal femur cortical thickness. This study represents an important step toward longitudinal clinical trials interested in monitoring the effectiveness of drug therapy on proximal femur cortical thickness.

Age-related inflammation triggers skeletal stem/progenitor cell dysfunction.

Aging is associated with impaired tissue regeneration. Stem cell number and function have been identified as potential culprits. We first demonstrate a direct correlation between stem cell number and time to bone fracture union in a human patient cohort. We then devised an animal model recapitulating this age-associated decline in bone healing and identified increased cellular senescence caused by a systemic and local proinflammatory environment as the major contributor to the decline in skeletal stem/progenitor cell (SSPC) number and function. Decoupling age-associated systemic inflammation from chronological aging by using transgenic Nfkb1KO mice, we determined that the elevated inflammatory environment, and not chronological age, was responsible for the decrease in SSPC number and function. By using a pharmacological approach inhibiting NF-κB activation, we demonstrate a functional rejuvenation of aged SSPCs with decreased senescence, increased SSPC number, and increased osteogenic function. Unbiased, whole-genome RNA sequencing confirmed the reversal of the aging phenotype. Finally, in an ectopic model of bone healing, we demonstrate a functional restoration of regenerative potential in aged SSPCs. These data identify aging-associated inflammation as the cause of SSPC dysfunction and provide mechanistic insights into its reversal.

Scaphoid Nonunions.

Scaphoid nonunions are challenging injuries to manage and the optimal treatment algorithm continues to be debated. Most scaphoid fractures heal when appropriately treated; however, when nonunions occur, they require acute treatment to prevent future complications like scaphoid nonunion advanced collapse. Acute nonunion treatment technique depends on nonunion location, vascular status of the proximal pole, fracture malalignment, and pre-existing evidence of arthrosis. Bone grafting and vascular grafts are common in nonunion management. Chronic nonunions that have progressed to scaphoid nonunion advanced collapse often require a salvage procedure such as four corner fusions, proximal row carpectomy, or wrist fusion. Herein, we review the current literature regarding scaphoid nonunions with regards to their anatomy, natural history, classification, diagnostic imaging, surgical management, and clinical outcomes.

Scaling Marker Position Determines the Accuracy of Digital Templating for Total Hip Arthroplasty.

BACKGROUND: Digital templating systems foster patient-specific measurements for preoperative planning. QUESTIONS/PURPOSES: We aim (1) to verify the accuracy of a templating system, (2) to describe the effects of scaling marker position on the accuracy of digital templating of the hip, and (3) to provide a practical guide for scaling marker position using patient body mass index (BMI). METHODS: A scaling sphere was placed in five positions along the anterior-posterior axis of an acetabular implant and pelvis phantom, and x-rays were obtained. Each radiograph was templated for the acetabular component and recorded. A retrospective review identified CT scans of preoperative hip arthroplasty cases. The center of the greater trochanter was calculated from these CT scans as the percent distance from the anterior thigh and recorded with the patient's BMI. RESULTS: By centering the scaling sphere on the acetabular component, an accurate cup size was achieved. A difference of 3.5 cm in sphere placement resulted in a full cup size magnification error. Positioning the scaling sphere at the level of the pubic symphysis resulted in a difference of four cup sizes. This patient population had an average BMI of 28.72 kg/m2 (standard deviation 6.26 kg/m2) and an average position of the center of the greater trochanter of 51% (standard deviation of 6%) from the anterior surface of thigh. CONCLUSIONS: Digital templating relies on scaling marker position to accurately estimate implant size. Based on the findings in this study, scaling markers for hip imaging should be placed laterally, mid-thigh in the anterior-posterior direction for patients with a BMI between 25 and 40 kg/m2. If abnormal hip anatomy or extremes of BMI are discovered, then scaling sphere positioning should be optimized on a case-by-case basis. Digital templating systems for total hip arthroplasty must use precisely placed scaling markers at the level of the hip joint to allow for accurate implant size estimation.

The Effect of Growth Hormone on Chondral Defect Repair.

Objective Focal chondral defects alter joint mechanics and cause pain and debilitation. Microfracture is a surgical technique used to treat such defects. This technique involves penetration of subchondral bone to release progenitor cells and growth factors from the marrow to promote cartilage regeneration. Often this results in fibrocartilage formation rather than structured hyaline cartilage. Some reports have suggested use of growth hormone (GH) with microfracture to augment cartilage regeneration. Our objective was to test whether intra-articular (IA) GH in conjunction with microfracture, improves cartilage repair in a rabbit chondral defect model. We hypothesized that GH would exhibit a dose-dependent improvement in regeneration. Design Sixteen New Zealand white rabbits received bilateral femoral chondral defects and standardized microfracture repair. One group of animals ( n = 8) received low-dose GH by IA injection in the left knee, and the other group ( n = 8) received high-dose GH in the same manner. All animals received IA injection of saline in the contralateral knee as control. Serum assays, macroscopic grading, and histological analyses were used to assess any improvements in cartilage repair. Results Peripheral serum GH was not elevated postoperatively ( P = 0.21). There was no improvement in macroscopic grading scores among either of the GH dosages ( P = 0.83). Scoring of safranin-O-stained sections showed no improvement in cartilage regeneration and some evidence of increased bone formation in the GH-treated knees. Conclusions Treatment with either low- or high-dose IA GH does not appear to enhance short-term repair in a rabbit chondral defect model.

Performance Outcomes After Hook of Hamate Fractures in Major League Baseball Players.

CONTEXT: Major League Baseball (MLB) players are at risk of hook of hamate fractures. There is a paucity of data assessing the effect of a hook of hamate fracture on MLB players' future athletic performance. OBJECTIVE: To determine if MLB players who sustain hook of hamate fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. DESIGN: Retrospective case-control design. SETTING: Retrospective database study. PARTICIPANTS: 18 MLB players who sustained hook of hamate fractures. METHODS: Data for 18 MLB players with hook of hamate fractures incurred over 26 seasons (1989-2014) were obtained from injury reports, press releases, and player profiles ( www.mlb.com and www.baseballreference.com ). Player age, position, number of years in the league, mechanism of injury, and treatment were recorded. Individual season statistics for the 2 seasons immediately prior to injury and the 2 seasons after injury for the main performance variable-Wins Above Replacement-were obtained. Eighteen controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. MAIN OUTCOME MEASURES: Postinjury performance compared with preinjury performance and matched-controls. RESULTS: Mean age at the time of injury was 25.1 years with a mean of 4.4 seasons of MLB experience prior to injury. All injuries were sustained to their nondominant batting hand. All players underwent operative intervention. There was no significant change in Wins Above Replacement or isolated power when preinjury and postinjury performance were compared. When compared with matched-controls, no significant decline in performance in Wins Above Replacement the first season and second season after injury was found. CONCLUSION: MLB players sustaining hook of hamate fractures can reasonably expect to return to their preinjury performance levels following operative treatment.

A Biomechanical Study of Two Distinct Methods of Anterior Cruciate Ligament Rupture, and a Novel Surgical Reconstruction Technique, in a Small Animal Model of Posttraumatic Osteoarthritis.

Small animal models are critical for studies of sports-related knee injury and disease such as posttraumatic osteoarthritis (PTOA) following anterior cruciate ligament (ACL) rupture. In such models, ACL damage can be achieved by surgical transection or, using a more recent innovation, by noninvasive biomechanical means. Whether these approaches differentially alter normal mechanics is unknown. Furthermore, while surgical reconstruction of ruptured ACL can greatly improve joint stability, its effect on PTOA development is also unclear. Our primary purpose was to characterize rodent knee joint mechanics in two models of ACL rupture using a novel quantitative laxity mechanical test. Our secondary aim was to characterize a new reconstruction technique using autograft tail tendon, and to assess its effect on joint mechanics. Our hypothesis was that surgical ACL transection would have a greater effect on joint mechanics. A total of 24 rat knee specimens underwent surgical or biomechanical ACL rupture and were stabilized using a new reconstruction technique using autograft tail tendon. Joint mechanics were assessed three times; preinjury, postinjury, and again after reconstruction, using quantitative joint laxity testing. Primary test readouts were maximum anteroposterior (AP) laxity, loading curve slope, and energy absorption. Student's t-tests were performed to identify intragroup differences. All surgical transections were completed successfully; maximum load in the biomechanical model was 67 ± 7.7 N, with a coefficient of variation of 11.43%. Surgical transection caused increased AP laxity, while biomechanical injury nonsignificantly increased this parameter. In both cases, these changes recovered to baseline by reconstruction. Loading curve slope was reduced in both models and was also returned to baseline by repair. Energy absorption followed the same pattern except it remained significantly different from baseline postreconstruction in the surgical group. This study supports our hypothesis knee joint mechanics is differentially affected by injury mechanism in a small animal model. We also report a novel reconstruction technique in this model, using autograft tail tendon.

Variance in predicted cup size by 2-dimensional vs 3-dimensional computerized tomography-based templating in primary total hip arthroplasty.

BACKGROUND: Preoperative total hip arthroplasty templating can be performed with radiographs using acetate prints, digital viewing software, or with computed tomography (CT) images. Our hypothesis is that 3D templating is more precise and accurate with cup size prediction as compared to 2D templating with acetate prints and digital templating software. METHODS: Data collected from 45 patients undergoing robotic-assisted total hip arthroplasty compared cup sizes templated on acetate prints and OrthoView software to MAKOplasty software that uses CT scan. Kappa analysis determined strength of agreement between each templating modality and the final size used. t tests compared mean cup-size variance from the final size for each templating technique. Interclass correlation coefficient (ICC) determined reliability of digital and acetate planning by comparing predictions of the operating surgeon and a blinded adult reconstructive fellow. RESULTS: The Kappa values for CT-guided, digital, and acetate templating with the final size was 0.974, 0.233, and 0.262, respectively. Both digital and acetate templating significantly overpredicted cup size, compared to CT-guided methods (P < .001). There was no significant difference between digital and acetate templating (P = .117). Interclass correlation coefficient value for digital and acetate templating was 0.928 and 0.931, respectively. CONCLUSIONS: CT-guided planning more accurately predicts hip implant cup size when compared to the significant overpredictions of digital and acetate templating. CT-guided templating may also lead to better outcomes due to bone stock preservation from a smaller and more accurate cup size predicted than that of digital and acetate predictions.

Contact Analysis of Horizontal Cleavage Tear Treatment.

Horizontal cleavage tears (HCT) commonly occur in the posterior horn of the medial meniscus due to aging and degeneration. The purpose of this study was to investigate the surgical treatment of HCTs and their effect on dynamic tibiofemoral contact mechanics. The tibiofemoral contact mechanics of 10 cadaver knees were investigated using a custom dynamic loading apparatus, pressure sensor, and motion sensing camera. Three loading conditions were analyzed: 500 N compressive load, 500 N compressive load with 100 N posterior shear, and 500 N compressive load with 2.5 Nm of internal torque. Real-time peak contact pressures and contact areas were recorded throughout the full range of motion. After testing the intact meniscal state, a horizontal cleavage tear was created and included 50% of the width of the meniscus. The following procedures were performed, and the loading conditions described above were analyzed: HCT superior flap removal (5 specimens), HCT inferior flap removal (remaining 5 specimens), and both flaps removed (all 10 specimens). Statistical analysis was performed using a mixed linear effects model using the R-statistical package. The mixed linear effects statistical model identified statistically significant differences between independent variables, including the procedure performed, meniscal flap removed, meniscal region, loading condition, and knee flexion angle with respect to contact area and peak contact pressure. Peak contact pressure and contact area were not affected by selective flap removal (superior vs. inferior) or removal of both flaps of the HCT. We recommend that in the treatment of horizontal cleavage tears of the posterior horn of the medial meniscus, the outer 50% of the posterior horn of the medial meniscus should be maintained for load transmission.

Cost-effectiveness of Virtual Bone Strength Testing in Osteoporosis Screening Programs for Postmenopausal Women in the United States.

Purpose To investigate whether assessment of bone strength with quantitative computed tomography (CT) in combination with dual-energy x-ray absorptiometry (DXA) is cost-effective as a screening tool for osteoporosis in postmenopausal women. Materials and Methods A state-transition microsimulation model of osteoporosis for postmenopausal women aged 55 years or older was developed with a lifetime horizon and U.S. societal perspective. All model inputs were derived from published literature. Three strategies were compared: no screening, DXA with T score-dependent rescreening intervals, and a combination of DXA and quantitative CT with different intervals (3, 5, and 10 years) at different screening initiation ages (55-65 years). Oral bisphosphonate therapy was started if DXA hip T scores were less than or equal to -2.5, 10-year risk for hip fracture was greater than 3% (World Health Organization Fracture Risk Assessment Tool score, or FRAX), 10-year risk for major osteoporotic fracture was greater than 20% (FRAX), quantitative CT femur bone strength was less than 3000 N, or occurrence of first fracture (eg, hip, vertebral body, wrist). Outcome measures were incremental cost-effectiveness ratios (ICERs) in 2015 U.S. dollars per quality-adjusted life year (QALY) gained and number of fragility fractures. Probabilistic sensitivity analysis was also performed. Results The most cost-effective strategy was combined DXA and quantitative CT screening starting at age 55 with quantitative CT screening every 5 years (ICER, $2000 per QALY). With this strategy, 12.8% of postmenopausal women sustained hip fractures in their remaining life (no screening, 18.7%; DXA screening, 15.8%). The corresponding percentages of vertebral fractures for DXA and quantitative CT with a 5-year interval, was 7.5%; no screening, 11.1%; DXA screening, 9%; for wrist fractures, 14%, 17.8%, and 16.4%, respectively; for other fractures, 22.6%, 30.8%, and 27.3%, respectively. In probabilistic sensitivity analysis, DXA and quantitative CT at age 55 years with quantitative CT screening every 5 years was the best strategy in more than 90% of all 1000 simulations (for thresholds of $50 000 per QALY and $100 000 per QALY). Conclusion Combined assessment of bone strength and bone mineral density is a cost-effective strategy for osteoporosis screening in postmenopausal women and has the potential to prevent a substantial number of fragility fractures. © RSNA, 2017 Online supplemental material is available for this article.