Clinician interest in clinical decision support for PSA-based prostate cancer screening.

OBJECTIVE: To evaluate the interest of primary care clinicians in utilizing CDS for PSA screening. Evidence suggests that electronic clinical decision support (CDS) may decrease low-value prostate-specific antigen (PSA) testing. However, physician attitudes towards CDS for PSA screening are largely unknown. METHODS: A survey was sent to 201 primary care clinicians, including both physicians and Advanced Practice Providers (APP), within a large academic health system. Eligible clinicians cared for male patients aged 40 to 80 years and ordered ≥5 PSA tests in the past year. Respondents were stratified into 3 groups, appropriate screeners, low-value screeners, or rare-screeners, based on responses to survey questions assessing PSA screening practices. The degree of interest in electronic CDS was determined via a composite Likert score comprising relevant survey items. RESULTS: Survey response rate was 29% (59/201) consisting of 85% MD/DO and 15% APP respondents. All clinicians surveyed were interested in CDS (P < 0.001) without significant difference between screener groups. Clinicians agreed most uniformly that CDS be evidence-based. Clinicians disagreed on whether CDS would decrease professional discretion over patient decisions. CONCLUSIONS: Primary care clinicians are interested in CDS for PSA screening regardless of their current screening practices. Prioritizing CDS features that clinicians value, such as ensuring CDS recommendations are evidence-based, may increase the likelihood of successful implementation, whereas perceived threat to autonomy may be a hinderance to utilization.

Addressing ethical and laboratory challenges for initiation of a rapid whole genome sequencing program.

Rapid whole genome sequencing (rapid WGS) is a powerful diagnostic tool that is becoming increasingly practical for widespread clinical use. However, protocols for its use are challenging to implement. A significant obstacle to clinical adoption is that laboratory certification requires an initial research development phase, which is constrained by regulations from returning results. Regulations preventing return of results have ethical implications in cases which might impact patient outcomes. Here, we describe our experience with the development of a rapid WGS research protocol, that balanced the requirements for laboratory-validated test development with the ethical needs of clinically relevant return of results.

Pathogenic Germline DNA Repair Gene and HOXB13 Mutations in Men With Metastatic Prostate Cancer.

PURPOSE: Germline mutations in DNA repair (DR) genes and susceptibility genes CDKN2A and HOXB13 have previously been associated with prostate cancer (PC) incidence and/or progression. However, the role and prevalence of this class of mutations in metastatic PC (mPC) are not fully understood. PATIENTS AND METHODS: To evaluate the frequency of pathogenic/likely pathogenic germline variants (PVs/LPVs) in men with mPC, this study sequenced 38 DR genes, CDKN2A, and HOXB13 in a predominantly white cohort of 317 patients with mPC. A PC registry at the University of Utah was used for patient sample acquisition and retrospective clinical data collection. Deep target sequencing allowed for germline and copy number variant analyses. Validated PVs/LPVs were integrated with clinical and demographic data for statistical correlation analyses. RESULTS: All pathogenic variants were found in men self-reported as white, with a carrier frequency of 8.5% (DR genes, 7.3%; CDKN2A/HOXB13, 1.2%). Consistent with previous reports, mutations were most frequently identified in the breast cancer susceptibility gene BRCA2. It was also found that 50% of identified PVs/LPVs were categorized as founder mutations with European origins. Correlation analyses did not support a trend toward more advanced or earlier-onset disease in comparisons between carriers and noncarriers of deleterious DR or HOXB13 G84E mutations. CONCLUSION: These findings demonstrate a lower prevalence of germline PVs/LPVs in an unselected, predominantly white mPC cohort than previously reported, which may have implications for the design of clinical trials testing targeted therapies. Larger studies in broad and diverse populations are needed to more accurately define the prevalence of germline mutations in men with mPC.

Risk of Prostate Cancer Associated With Familial and Hereditary Cancer Syndromes.

PURPOSE: Recently developed clinical guidelines suggest that men in families with specific cancer syndromes, such as hereditary breast and ovarian cancer (HBOC), consider genetic testing, especially in the setting of aggressive disease. However, although a family history (FH) of the same disease among close relatives is an established risk factor for prostate cancer (PC), a direct comparison of PC risk for men with each syndrome in a single population is needed. METHODS: The Utah Population Database was used to identify 619,630 men, age ≥ 40 years, who were members of a pedigree that included at least 3 consecutive generations. Each man was evaluated for FH of hereditary PC (HPC), HBOC, and Lynch syndrome (LS) and for his own PC status. PC occurrences (N = 36,360) were classified into one or more subtypes: early onset (EO), lethal, and/or clinically significant. Relative risks (RRs) associated with each subtype, adjusted for important covariables, were calculated in STATA using a modified Poisson regression with robust error variances to obtain corresponding RR CIs for each FH definition. RESULTS: An FH of HPC conveyed the greatest relative risk for all PC subtypes combined (RR, 2.30; 95% CI, 2.22 to 2.40), followed by HBOC and LS (both with 1 < RR < 2 and statistically significant). The strongest risks associated with FH were observed for EO disease in all pedigree types, consistent with the contribution of genetic factors to disease occurrence. CONCLUSION: In this large, population-based, family database, the risk of PC varied by cancer FH and was most strongly associated with EO disease. These results are critically valuable in understanding and targeting high-risk populations that would benefit from genetic screening and enhanced surveillance.

Isolated focal cartilage and labral defects in patients with femoroacetabular impingement syndrome may represent new, unique injury patterns.

PURPOSE: Develop a framework to quantify the size, location and severity of femoral and acetabular-sided cartilage and labral damage observed in patients undergoing hip arthroscopy, and generate a database of individual defect parameters to facilitate future research and treatment efforts. METHODS: The size, location, and severity of cartilage and labral damage were prospectively collected using a custom, standardized post-operative template for 100 consecutive patients with femoroacetabular impingement syndrome. Chondrolabral junction damage, isolated intrasubstance labral damage, isolated acetabular cartilage damage and femoral cartilage damage were quantified and recorded using a combination of Beck and ICRS criteria. Radiographic measurements including alpha angle, head-neck offset, lateral centre edge angle and acetabular index were calculated and compared to the aforementioned chondral data using a multivariable logistic regression model and adjusted odd's ratio. Reliability among measurements were assessed using the kappa statistic and intraclass coefficients were used to evaluate continuous variables. RESULTS: Damage to the acetabular cartilage originating at the chondrolabral junction was the most common finding in 97 hips (97%) and was usually accompanied by labral damage in 65 hips (65%). The width (p = 0.003) and clock-face length (p = 0.016) of the damaged region both increased alpha angle on anteroposterior films. 10% of hips had femoral cartilage damage while only 2 (2%) of hips had isolated defects to either the acetabular cartilage or labrum. The adjusted odds of severe cartilage (p = 0.022) and labral damage (p = 0.046) increased with radiographic cam deformity but was not related to radiographic measures of acetabular coverage. CONCLUSIONS: Damage at the chondrolabral junction was very common in this hip arthroscopy cohort, while isolated defects to the acetabular cartilage or labrum were rare. These data demonstrate that the severity of cam morphology, quantified through radiographic measurements, is a primary predictor of location and severity of chondral and labral damage and focal chondral defects may represent a unique subset of patients that deserve further study. LEVEL OF EVIDENCE: IV.

Patient-Specific Parameters Associated With Traction in Primary and Revision Hip Arthroscopic Surgery.

BACKGROUND: Distraction of the hip joint is a necessary step during hip arthroscopic surgery. The force of traction needed to distract the hip is not routinely measured, and little is known about which patient factors may influence this force. PURPOSE: To quantify the force of traction required for adequate distraction of the hip during arthroscopic surgery and explore the relationship between hip joint stiffness and patient-specific demographics, flexibility, and anatomy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 101 patients (61 female) undergoing primary hip arthroscopic surgery were prospectively enrolled. A load cell attached to the traction boot continuously measured traction force. Fluoroscopic images were obtained before and after traction to measure joint displacement. The stiffness coefficient was calculated as the force of traction divided by joint displacement. Relationships between the stiffness coefficient and patient demographics and clinical parameters were investigated using a univariable regression model. The regression analysis was repeated separately by patient sex. Variables significant at P < .05 were included in a multivariable regression model. RESULTS: The instantaneous peak force averaged 80 ± 18 kilogram-force (kgf), after which the force required to maintain distraction decreased to 57 ± 13 kgf. In univariable regression analysis, patient sex, alpha angle, hamstring flexibility, and Beighton hypermobility score were each correlated to stiffness. However, patient sex was the only significant variable in the multivariable regression model. Intrasex analysis demonstrated that increased hamstring flexibility correlated with decreased final holding stiffness in male patients and that higher Beighton scores correlated with decreased maximal stiffness in female patients. CONCLUSION: Male patients undergoing primary arthroscopic surgery have greater stiffness to hip distraction during arthroscopic surgery compared with female patients. In male patients, stiffness increased with decreasing hamstring flexibility. In female patients, increased Beighton scores corresponded to decreased stiffness. The presence of a labral tear was not correlated with stiffness to distraction. These data may be used to identify patients in whom a specific focus on capsular repair and/or plication may be warranted.

Germline mutations in PPFIBP2 are associated with lethal prostate cancer.

BACKGROUND: Few genes have germline mutations which predispose men to more aggressive prostate cancer (PCa). This study evaluated the contribution of germline loss of function (LOF) variants in PPFIBP2 to risk of lethal PCa. METHODS: A case-case study of 1414 PCa patients with lethal PCa and low-risk localized PCa was performed. Germline DNA samples from these patients were sequenced for PPFIBP2. Mutation carrier rates and association with lethal PCa were analyzed using the Fisher exact test, logistic regression, and Kaplan-Meier survival analysis. RESULTS: In the entire study population, eight patients, all of European ancestry, were identified as carrying PPFIBP2 pathogenic or likely pathogenic mutations. Seven (1.52%) of 462 lethal PCa patients were carriers compared with only one (0.12%) carrier in 810 low-risk PCa patients, P = 0.0029. The estimated Odds Ratio (OR) of carrying PPFIBP2 mutation for lethal PCa was 13.8 in European American population. The PPFIBP2 loss-of-function mutation carrier rate in lethal PCa cases was also higher than in 33 370 non-Finnish European individuals from the Exome Aggregation Consortium (ExAC) (carrier rate of 0.17%, P = 1.92 × 10-5 ) and in 498 men with localized PCa from The Cancer Genome Atlas cohort (TCGA) cohort (carrier rate of 0%, P = 0.0058). Survival analysis in European American lethal cases revealed PPFIBP2 mutation status as an independent predictor of shorter survival after adjusting for age at diagnosis, PSA at diagnosis, and genetic background (hazard ratio = 2.62, P = 0.034). CONCLUSIONS: While larger studies are needed, germline mutations in a novel gene, PPFIBP2, differentiated risk for lethal PCa from low-risk cases and were associated with shorter survival times after diagnosis.

Germline genetic variants in men with prostate cancer and one or more additional cancers.

BACKGROUND: Prostate cancer has a significant heritable component, and rare deleterious germline variants in certain genes can increase the risk of the disease. The aim of the current study was to describe the prevalence of pathogenic germline variants in cancer-predisposing genes in men with prostate cancer and at least 1 additional primary cancer. METHODS: Using a multigene panel, the authors sequenced germline DNA from 102 men with prostate cancer and at least 1 additional primary cancer who also met ≥1 of the following criteria: 1) age ≤55 years at the time of diagnosis of the first malignancy; 2) rare tumor type or atypical presentation of a common tumor; and/or 3) ≥3 primary malignancies. Cancer family history and clinicopathologic data were independently reviewed by a clinical genetic counselor to determine whether the patient met established criteria for testing for a hereditary cancer syndrome. RESULTS: Sequencing identified approximately 3500 variants. Nine protein-truncating deleterious mutations were found across 6 genes, including BRCA2, ataxia telangiectasia mutated (ATM), mutL homolog 1 (MLH1), BRCA1 interacting protein C-terminal helicase 1 (BRIP1), partner and localizer of BRCA2 (PALB2), and fibroblast growth factor receptor 3 (FGFR3). Likely pathogenic missense variants were identified in checkpoint kinase 2 (CHEK2) and homeobox protein Hox-B13 (HOXB13). In total, 11 of 102 patients (10.8%) were found to have pathogenic or likely pathogenic mutations in cancer-predisposing genes. The majority of these men (64%) did not meet current clinical criteria for germline testing. CONCLUSIONS: Men with prostate cancer and at least 1 additional primary cancer are enriched for harboring a germline deleterious mutation in a cancer-predisposing gene that may impact cancer prognosis and treatment, but the majority do not meet current criteria for clinical genetic testing. Cancer 2017;123:3925-32. © 2017 American Cancer Society.

Relationship Between the Lateral Center-Edge Angle and 3-Dimensional Acetabular Coverage.

BACKGROUND: The lateral center-edge angle (LCEA) is an important measurement in understanding acetabular morphology and has had multiple interpretations. Misunderstanding of the LCEA and its relationship with acetabular 3-dimensional (3D) morphology may result in misdiagnosis and poor outcomes. PURPOSE: To determine the discrepancy between bone-edge and sourcil-edge LCEA measurements on anteroposterior (AP) radiographs and to determine the 3D anatomic location of the sourcil-edge and bone-edge LCEA measurements. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: The LCEA was measured on radiographs to both the sourcil-edge and bone-edge on AP images of 60 symptomatic hips. On computed tomography (CT), coronal slices producing an LCEA matching the magnitude of each AP LCEA were identified. These coronal slices were mapped to a sagittal image of the acetabulum, which was divided into a standard clockface (3 = anterior, 12 = superior). We identified clockface locations corresponding to the AP sourcil-edge and bone-edge LCEA measurements. Paired t tests identified differences in magnitude and location of the bone and sourcil LCEAs. Limits of agreement were calculated for the differences between measures. Intraclass correlation coefficients (ICCs) assessed inter- and intraobserver repeatability. RESULTS: On the AP radiographs, the bone-edge LCEA was a mean 4.7° (95% CI, -4.0° to 13.3°) greater than the sourcil-edge LCEA (P < .001). On CT, the sagittal clockface location of the sourcil-edge LCEA was more anterior compared with the sagittal clockface location of the maximum bone-edge LCEA (1:03 ± 0:42 vs 12:06 ± 0:30, respectively; P < .001). In hips with a difference >5° between sourcil-edge and bone-edge measurements, the coronal CT slice corresponding to the sourcil-edge LCEA was significantly more anterior (1:26 ± 0:35) than the CT slice corresponding to the bone-edge LCEA (11:46 ± 0:29; P < .001). This significant difference was similar in location but less pronounced in hips with a difference ≤5°: the sourcil-edge LCEA occurred at 12:50 ± 0:40, while the bone-edge LCEA occurred at 12:00 ± 0:11 (P < .001). Interobserver repeatability was excellent for all LCEA and clockface location measurements (all ICCs >0.82). CONCLUSION: The sourcil-edge LCEA represents anterosuperior acetabular coverage while the bone-edge LCEA represents superior/lateral coverage. This information can be used in preoperative evaluation of and perioperative planning for hip preservation procedures.

Accuracy and Reliability of Computed Tomography and Magnetic Resonance Imaging Compared With True Anatomic Femoral Version.

BACKGROUND: Abnormal torsion of the femur is correlated to lower extremity pathologies. Although computed tomography (CT) scan is the gold standard torsional measurement, magnetic resonance imaging (MRI) is proposed as a viable alternative. Our aim was to determine the accuracy and consistency of MRI and CT femur rotational studies based on 4 described protocols. METHODS: Twelve cadaveric femora were stripped of soft tissue before imaging and physical assessment of torsion. Four advanced imaging series were obtained for each specimen: CT with axial cuts of the femoral neck (CT-axial); CT with oblique cuts of the femoral neck (CT-oblique); MRI with axial cuts of the femoral neck (MR-axial); MRI with oblique cuts of the femoral neck (MR-oblique). Anatomic specimens were placed with the posterior femoral condyles flat on a dissection table for assessment of true torsion with digital images. Three independent reviewers performed all measurements, including true torsion, using imaging software. Bland-Altman analysis was repeated with the data from each reviewer. RESULTS: Interobserver repeatability for all groups was high at 0.95, 0.87, 0.90, 0.97, and 0.92 for CT-axial, CT-oblique, MR-axial, MR-oblique, and true torsion, respectively. CT-axial had the lowest mean difference from clinical imaging for all three observers (all <1 degree) and held the tightest 95% limits of agreement for 2/3 observers. As torsion increases from neutral, MR-oblique linearly overestimates the rotation compared with true torsion. CT-oblique and MR-axial showed slightly greater differences from true torsion compared with CT-axial, but did not reach clinical significance. CONCLUSIONS: CT-axial was both most accurate and reproducible when compared with true torsion of the femur and should be the gold standard imaging modality; however, both MR-axial and CT-oblique were accurate to a level that is likely less than clinical significance. MR-axial images should be used in clinical situations where radiation exposure needs to be limited. MR-oblique images can overestimate true antetorsion and should not be used. CLINIC SIGNIFICANCE: CT-axial followed by MRI-axial is the most accurate and consistent in measuring true torsion of the femur.

The mechanics of focal chondral defects in the hip.

There is a mean incidence of osteoarthritis (OA) of the hip in 8% of the overall population. In the presence of focal chondral defects, defined as localized damage to the articular cartilage, there is an increased risk of symptomatic progression toward OA. This relationship between chondral defects and subsequent development of OA has led to substantial efforts to develop effective procedures for surgical cartilage repair. This study examined the effects of chondral defects and labral delamination on cartilage mechanics in the dysplastic hip during the gait cycle using subject-specific finite element analysis. Models were generated from volumetric CT data and analyzed with simulated chondral defects at the chondrolabral junction on the posterior acetabulum during five distinct points in the gait cycle. Focal chondral defects increased maximum shear stress on the osteochondral surface of the acetabular cartilage, when compared to the intact case. This effect was amplified with labral delamination. Additionally, chondral defects increased the first principal Lagrange strain on the articular surface of the acetabular cartilage and labrum. Labral delamination relieved some of this tensile strain. As defect size was increased, contact stress increased in the medial zone of the acetabulum, while it decreased anteriorly. The results suggest that in the presence of chondral defects and labral delamination the cartilage experiences elevated tensile strains and shear and contact stress, which could lead to further damage of the cartilage, and subsequent arthritic progression. The framework presented here will serve as the procedure for future finite element studies on cartilage mechanics in hips with varying disease states with simulated chondral defects and labral tears.

In Vivo Kinematics of the Tibiotalar and Subtalar Joints in Asymptomatic Subjects: A High-Speed Dual Fluoroscopy Study.

Measurements of joint kinematics are essential to understand the pathomechanics of ankle disease and the effects of treatment. Traditional motion capture techniques do not provide measurements of independent tibiotalar and subtalar joint motion. In this study, high-speed dual fluoroscopy images of ten asymptomatic adults were acquired during treadmill walking at 0.5 m/s and 1.0 m/s and a single-leg, balanced heel-rise. Three-dimensional (3D) CT models of each bone and dual fluoroscopy images were used to quantify in vivo kinematics for the tibiotalar and subtalar joints. Dynamic tibiotalar and subtalar mean joint angles often exhibited opposing trends during captured stance. During both speeds of walking, the tibiotalar joint had significantly greater dorsi/plantarflexion (D/P) angular ROM than the subtalar joint while the subtalar joint demonstrated greater inversion/eversion (In/Ev) and internal/external rotation (IR/ER) than the tibiotalar joint. During balanced heel-rise, only D/P and In/Ev were significantly different between the tibiotalar and subtalar joints. Translational ROM in the anterior/posterior (AP) direction was significantly greater in the subtalar than the tibiotalar joint during walking at 0.5 m/s. Overall, our results support the long-held belief that the tibiotalar joint is primarily responsible for D/P, while the subtalar joint facilitates In/Ev and IR/ER. However, the subtalar joint provided considerable D/P rotation, and the tibiotalar joint rotated about all three axes, which, along with translational motion, suggests that each joint undergoes complex, 3D motion.

Distal Femoral Osteotomy for the Valgus Knee: Medial Closing Wedge Versus Lateral Opening Wedge: A Systematic Review.

PURPOSE: (1) To determine the radiographic correction/healing rate, patient-reported outcomes, reoperation rate, and complication rate after distal femoral osteotomy (DFO) for the valgus knee with lateral compartment pathology. (2) To summarize the reported results of medial closing wedge and lateral opening wedge DFO. METHODS: We conducted a systematic review of PubMed, MEDLINE, and CINAHL to identify studies reporting outcomes of DFOs for the valgus knee. Keywords included "distal femoral osteotomy," "chondral," "cartilage," "valgus," "joint restoration," "joint preservation," "arthritis," and "gonarthrosis." Two authors first reviewed the articles; our study exclusion criteria were then applied, and the articles were included on the basis relevance defined by the aforementioned criteria. The Methodological Index for Nonrandomized Studies scale judged the quality of the literature. Sixteen studies were relevant to the research questions out of 191 studies identified by the original search. RESULTS: Sixteen studies were identified reporting on 372 osteotomies with mean follow-up of 45 to 180 months. All studies reported mean radiographic correction to a near neutral mechanical axis, with 3.2% nonunion and 3.8% delayed union rates. There was a 9% complication rate and a 34% reoperation rate, of which 15% were converted to arthroplasty. There were similar results reported for medial closing wedge and lateral opening wedge techniques, with a higher conversion to arthroplasty in the medial closing wedge that was confounded by longer mean follow-up in this group (mean follow-up 100 v 58 months). CONCLUSIONS: DFOs for the valgus knee with lateral compartment disease provide improvements in patient-reported knee health-related quality of life at midterm follow-up but have high rates of reoperation. No evidence exists proving better results of either the lateral opening wedge or medial closing wedge techniques. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

The Functional and Structural Outcomes of Arthroscopic Iliopsoas Release.

BACKGROUND: Arthroscopic release of the iliopsoas tendon may alleviate pain associated with internal snapping hip, but previous reports of physical function, hip strength, and muscle atrophy after surgery are mixed. HYPOTHESIS: The hips of patients who underwent arthroscopic iliopsoas release would demonstrate significantly reduced hip flexion strength and iliopsoas muscle volume when compared with their contralateral hips and the hips of patients who underwent hip arthroscopy without psoas release. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Eighteen patients who underwent hip arthroscopy with iliopsoas release for symptomatic internal snapping hip and concomitant femoroacetabular impingement (FAI) and/or chondrolabral damage (release group) and 18 patients who underwent arthroscopy for FAI and/or chondrolabral damage without iliopsoas release (control group) were evaluated at a mean of 21 months (range, 16-30 months) postoperatively. Magnetic resonance images were performed and segmented to calculate iliopsoas volume. Isometric hip flexion strength was evaluated in the supine and seated positions with a custom testing apparatus. Differences between groups and differences between the operative and nonoperative limbs within groups were compared with unpaired and paired t tests, respectively. RESULTS: In the release group, the iliopsoas muscle of the surgical limb was significantly smaller (288 ± 98 vs 384 ± 113 cm(3), P < .001) and weaker in the seated position (13 ± 4.7 vs 17 ± 5.8 kg, P < .001) than the contralateral limb. Compared with the control group, the release group demonstrated a greater percentage decrease in iliopsoas volume on magnetic resonance imaging (-25% ± 9.1% vs -0.6% ± 4.6%, P < .001) and seated hip flexion strength (-19% ± 16% vs -3.9% ± 20%, P = .018) between the operative and contralateral limbs. There were no significant differences in supine strength between limbs or groups (all P > .168). CONCLUSION: Arthroscopic iliopsoas release results in iliopsoas atrophy with a 25% volume loss and a 19% reduction in seated hip flexion strength.

Failures and Reoperations After Matrix-Assisted Cartilage Repair of the Knee: A Systematic Review.

PURPOSE: To quantify the reported failures and reoperations for the emerging technique of matrix-assisted cartilage repair at short-term and midterm follow-up. METHODS: We conducted a systematic review of 3 databases from March 2004 to February 2014 using keywords important for articular cartilage repair. Two authors reviewed the articles, the study exclusion criteria were applied, and articles were determined to be relevant (or not) to the research question. All studies with a minimum of 2 years' clinical follow-up were reviewed for all reported reoperations. The reasons for reoperations were recorded. RESULTS: We reviewed 66 articles from the 301 articles identified in the original systematic search. There were 60 articles on matrix-assisted cartilage transplantation and 6 articles on matrix-induced chondrogenesis. The matrix-assisted cartilage transplantation studies reported on a total of 1,380 patients at 2 to 5 years' follow-up. Among these, there were 72 reoperations (5%) including 46 treatment failures (3%). These numbers increased to an 11% reoperation rate and 9% treatment failure rate at minimum 5-year follow-up of 961 patients. The most common procedures performed other than revision cartilage surgery or arthroplasty were manipulation under anesthesia for arthrofibrosis (0.7%) and debridement for graft hypertrophy (1.2%). The matrix-induced chondrogenesis studies reported on 163 patients. Among these, there were 15 reoperations (9%) that included 4 treatment failures (2%), 9 manipulations under anesthesia (6%), and 2 debridements for graft hypertrophy (1%). CONCLUSIONS: Treatment failure rates for matrix-assisted cartilage repair increase from short-term to midterm follow-up, with 11% of patients having undergone further surgery at a minimum of 5 years' follow-up. These data can be used to counsel patients on the potential need for further operative intervention after this emerging cartilage repair technique.

Accuracy of Functional and Predictive Methods to Calculate the Hip Joint Center in Young Non-pathologic Asymptomatic Adults with Dual Fluoroscopy as a Reference Standard.

Predictions from biomechanical models of gait may be sensitive to joint center locations. Most often, the hip joint center (HJC) is derived from locations of reflective markers adhered to the skin. Here, predictive techniques use regression equations of pelvic anatomy to estimate the HJC, whereas functional methods track motion of markers placed at the pelvis and femur during a coordinated motion. Skin motion artifact may introduce errors in the estimate of HJC for both techniques. Quantifying the accuracy of these methods is an area of open investigation. In this study, we used dual fluoroscopy (DF) (a dynamic X-ray imaging technique) and three-dimensional reconstructions from computed tomography images, to measure HJC locations in vivo. Using dual fluoroscopy as the reference standard, we then assessed the accuracy of three predictive and two functional methods. Eleven non-pathologic subjects were imaged with DF and reflective skin marker motion capture. Additionally, DF-based solutions generated virtual markers placed on bony landmarks, which were input to the predictive and functional methods to determine if estimates of the HJC improved. Using skin markers, functional methods had better mean agreement with the HJC measured by DF (11.0 ± 3.3 mm) than predictive methods (18.1 ± 9.5 mm); estimates from functional and predictive methods improved when using the DF-based solutions (1.3 ± 0.9 and 17.5 ± 8.6 mm, respectively). The Harrington method was the best predictive technique using both skin markers (13.2 ± 6.5 mm) and DF-based solutions (10.6 ± 2.5 mm). The two functional methods had similar accuracy using skin makers (11.1 ± 3.6 and 10.8 ± 3.2 mm) and DF-based solutions (1.2 ± 0.8 and 1.4 ± 1.0 mm). Overall, functional methods were superior to predictive methods for HJC estimation. However, the improvements observed when using the DF-based solutions suggest that skin motion artifact is a large source of error for the functional methods.

Influence of Ankle Position and Radiographic Projection Angle on Measurement of Supramalleolar Alignment on the Anteroposterior and Hindfoot Alignment Views.

BACKGROUND: Using digitally reconstructed radiographs (DRRs), we determined how changes in the x-ray beam projection angle from the horizon, tibiotalar joint angle, and axial rotation of the foot influenced measurements of the medial distal tibial angle (MDTA) on the anteroposterior (AP) and hindfoot alignment views (HAV). METHODS: Seven cadaver foot-ankle specimens were scanned by computed tomography (CT) at fixed tibiotalar joint positions, ranging from 15 degrees of dorsiflexion to 25 degrees of plantarflexion. DRRs were created from each CT scan to simulate alterations in the horizontal projection angle (0 to 25 degrees) and foot axial rotation (-30 to 30 degrees). The MDTA was measured on each DRR and compared with that quantified on the baseline HAV and AP view. RESULTS: Altering the horizontal projection angle by ≥5 degrees and >10 degrees significantly altered the MDTA for the AP view and the HAV, respectively. Shifting dorsiflexion and plantarflexion caused minor changes in the MDTA that were only statistically significant for the HAV. Axial rotation significantly changed the MDTA on both views, but deviations were more pronounced for the HAV. CONCLUSIONS: Compared with the HAV, the MDTA on the AP view was less sensitive to changes in foot-ankle position. However, increasing the tilt of the x-ray beam from the horizon altered the MDTA on the AP view substantially. CLINICAL RELEVANCE: To avoid misinterpretation of the MDTA, we recommend using the AP view to quantify supramalleolar alignment as it is less sensitive to changes in positioning of the foot-ankle. When acquiring an AP film, the x-ray beam should be directed along the horizon to ensure consistent assessment of the MDTA across patients.

Detection of a traumatic arthrotomy in the pediatric knee using the saline solution load test.

BACKGROUND: The objective of this study was to quantify the load volume needed for a positive diagnosis of a traumatic arthrotomy in the pediatric knee with use of the saline solution load test (SLT). METHODS: From February 2013 to June 2014, eighty-seven pediatric patients who were undergoing elective knee arthroscopy were prospectively enrolled in this study. An SLT was performed in each patient using a 5-mm superolateral portal as the arthrotomy site, with injection of the saline solution into the lateral aspect of the knee. The 50th, 75th, 90th, and 95th percentiles of saline solution load volume required for a positive result were identified. Univariate linear regression was used to identify possible relationships between demographics (age, height, weight, and body mass index [BMI]) and load volume. RESULTS: Forty-one female and forty-six male patients with a mean age (and standard deviation) of 13.4 ± 3.0 years (range, five to eighteen years) and a mean BMI of 21.9 ± 5.0 kg/m(2) (range, 12.9 to 36.2 kg/m(2)) were enrolled. The mean saline solution load volume was 28.9 ± 14.2 mL (range, 7.0 to 78 mL). The 50th, 75th, 90th, and 95th percentiles of saline solution load volume were 27, 37, 47, and 58 mL, respectively. The mean load volume did not differ significantly between male and female patients (28.8 ± 13.9 versus 29.0 ± 14.7 mL, respectively; p = 0.92). Load volume was significantly correlated with age, height, weight, and BMI. CONCLUSIONS: On the basis of our findings, a saline solution load volume of 47 mL is required to detect 90% of superolateral traumatic arthrotomies of 5 mm in the pediatric knee with use of the SLT.

In-vivo hip arthrokinematics during supine clinical exams: Application to the study of femoroacetabular impingement.

Visualization of hip articulation relative to the underlying anatomy (i.e., arthrokinematics) is required to understand hip dysfunction in femoroacetabular (FAI) patients. In this exploratory study, we quantified in-vivo arthrokinematics of a small cohort of asymptomatic volunteers and three symptomatic patients with varying FAI deformities during the passive impingement, FABER, and rotational profile exams using dual fluoroscopy and model-based tracking. Joint angles, joint translations, and relative pelvic angles were calculated. Compared to the 95% confidence interval of the asymptomatic cohort, FAI patients appeared to have decreased adduction and internal rotation during the impingement exam and greater flexion and less abduction/external rotation in the FABER exam. During the rotational profile, only the FAI patient with the most severe deformities demonstrated considerable rotation deficits. In all participants, contact between the labrum and femoral head/neck limited motion during the impingement exam, but not the rotational profile. Substantial pelvic motion was measured during the impingement exam and FABER test in all participants. Femoral translation along any given anatomical direction ranged between 0.69 and 4.1mm. These results suggest that hip articulation during clinical exams is complex in asymptomatic hips and hips with FAI, incorporating pelvic motion and femur translation. Range of motion appears to be governed by femur-labrum contact and other soft tissue constraints, suggesting that current computer simulations that rely on direct bone contact to predict impingement may be unrealistic. Additional research is necessary to confirm these preliminary results. Still, dual fluoroscopy data may serve to validate existing software platforms or create new programs that better-represent hip arthrokinematics.