Assessment of Hindfoot Alignment Comparing Weightbearing Radiography to Weightbearing Computed Tomography.

BACKGROUND: Hindfoot alignment view (HAV) radiographs are widely utilized for 2-dimensional (2D) radiographic assessment of hindfoot alignment; however, the development of weightbearing computed tomography (WBCT) may provide more accurate methods of quantifying 3-dimensional (3D) hindfoot alignment. The aim of this study was to compare the 2D calcaneal moment arm measurements on HAV radiographs with WBCT. METHODS: This retrospective cohort study included 375 consecutive patients with both HAV radiographs and WBCT imaging. Measurement of the 2D hindfoot alignment moment arm was compared between both imaging modalities. The potential confounding influence of valgus/varus/neutral alignment, presence of hardware, and motion artifact were further analyzed. RESULTS: The intraclass correlation coefficients (ICCs) of interobserver and intraobserver reliability for measurements with both imaging modalities were excellent. Both modalities were highly correlated (Spearman coefficient, 0.930; P < .001). HAV radiographs exhibited a mean calcaneal moment arm difference of 3.9 mm in the varus direction compared with WBCT (95% CI, -4.9 to 12.8). The difference of hindfoot alignment between both modalities was comparable in subgroups with neutral/valgus/varus alignment, presence of hardware, and motion artifact. CONCLUSION: Both HAV radiographs and WBCT are highly reliable and highly correlated imaging methods for assessing hindfoot alignment. Measurements were not influenced by severe malalignment, the presence of hardware, or motion artifact on WBCT. On average, HAV radiographs overestimated 3.9 mm of varus alignment as compared with WBCT. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Comparative assessment of midfoot osteoarthritis diagnostic sensitivity using weightbearing computed tomography vs weightbearing plain radiography.

PURPOSE: Accuracy in diagnosing osteoarthritis in the midfoot using weightbearing plain radiography (WBPR) remains questionable due to the overlapping osseous architecture present, occluding visualization. Weightbearing computed tomography (WBCT), providing clearer bony landmark identification and joint space visualization, can also be used for evaluation. The aim of this project is to perform a standardized retrospective intra-patient analysis identifying the discrepancy of midfoot osteoarthritis diagnosis and osteoarthritis severity grading between WBPR and WBCT. METHODS AND MATERIALS: A cohort of 302 patient feet was acquired from an internal, consecutive patient database using detailed inclusion criteria. The musculoskeletal radiologist interpretation of the WBCT and WBPR of each specimen was then assessed for any direct diagnosis or mention of osteoarthritic signs in specific articulations of 3 midfoot joint groups (Chopart, "central", and tarsometatarsal). WBPR sensitivity and specificity metrics were calculated with WBCT considered the gold standard for comparison. RESULTS: From the WBPR radiologist interpretation, we found diagnostic sensitivity of 72.5 % and specificity of 87.9 % for Chopart joints; 61.5 % sensitivity, and 96.1 % specificity for central joints; and 68.4 % sensitivity, and 92.9 % specificity for tarsometatarsal joints. The severity of degenerative changes was also consistently underestimated when interpreted from WBPR relative to WBCT. CONCLUSIONS: In this series, midfoot osteoarthritis was often undetected on WBPR. WBCT imaging facilitates an earlier, more reliable diagnosis and grading of midfoot osteoarthritis relative to WBPR.

Impact of Torque on Assessment of Syndesmotic Injuries Using Weightbearing Computed Tomography Scans.

BACKGROUND: The diagnosis of subtle injuries to the distal tibiofibular syndesmosis remains elusive. Conventional radiographs miss a large subset of injuries that present without frank diastasis. This study evaluated the impact of torque application on the assessment of syndesmotic injuries when using weightbearing computed tomography (CT) scans. METHODS: Seven pairs of male cadavers (tibia plateau to toe-tip) were included. CT scans with axial load application (85 kg) and with (10 Nm) or without torque to the tibia (corresponding to external rotation of the foot and ankle) were taken during 4 test conditions. First, intact ankles (native) were scanned. Second, 1 specimen from each pair underwent anterior inferior tibiofibular ligament (AITFL) transection (condition 1A), while the contralateral underwent deltoid transection (condition 1B). Third, the lesions were reversed on the same specimens and the remaining intact deltoid or AITFL was transected (condition 2). Finally, the distal tibiofibular interosseous membrane (IOM) was transected in all ankles (condition 3). Measurements were performed to assess the integrity of the distal tibiofibular syndesmosis on digitally reconstructed radiographs (DRRs) and on axial CT scans. RESULTS: Torque impacted DRR and axial CT scan measurements in almost all conditions. The ability to diagnose syndesmotic injuries using axial CT measurements improved when torque was applied. No significant syndesmotic morphological change was observed with or without torque for either isolated AITFL or deltoid ligament transection. DISCUSSION: Torque application had a notable impact on two-dimensional (2-D) measurements used to diagnose syndesmotic injuries for both DRRs and axial CT scans. Because weightbearing conditions allow for standardized positioning of the foot while radiographs or CT scans are taken, the combination of axial load and torque application may be desirable. CLINICAL RELEVANCE: Application of torque to the tibia impacts 2-D measurements and may be useful when diagnosing syndesmotic injuries by DRRs or axial CT images.

Association Between Orthopaedic Outpatient Satisfaction and Non-Modifiable Patient Factors.

BACKGROUND: Increasingly, patient satisfaction surveys are being utilized to evaluate hospital and physician performance. Despite this, little is known about factors associated with patient satisfaction. The objective of this study was to determine whether selected non-modifiable patient characteristics are associated with outpatient satisfaction scores. METHODS: We reviewed patient satisfaction scores from 12,177 outpatient clinical encounters at an academic orthopaedic outpatient clinic between December 2010 and October 2013. Any adult patient who completed at least one patient satisfaction survey at any point during the study period was included in this study. Factors including age, sex, employment status, type of health insurance, zip code, and orthopaedic subspecialty were recorded. Patients were divided into more satisfied and less satisfied groups, and generalized estimating equation logistic regression analysis was performed to identify factors predictive of lower patient satisfaction. RESULTS: Age was found to be strongly associated with patient satisfaction, with younger patients reporting less satisfaction; the adjusted odds ratio for the patient age of eighteen to twenty-nine years compared with the patient age of eighty years or older was 2.78 (95% confidence interval, 1.74 to 3.82) (p < 0.001). This relationship was maintained in a predictive model across all age groups, both sexes, all travel distances, and all orthopaedic subspecialties. Travel distance was also associated with patient satisfaction, with patients who live closer reporting less satisfaction compared with patients who live farther away; the adjusted odds ratio for a distance of less than fifty miles compared with a distance of fifty miles or more was 1.18 (95% confidence interval, 1.03 to 1.33) (p = 0.016). CONCLUSIONS: The finding that non-modifiable patient factors such as age and geographic location affect patient satisfaction challenges the utility of comparing patient satisfaction between populations that differ significantly with regard to such characteristics. CLINICAL RELEVANCE: A more complete knowledge of the factors that influence patient satisfaction may enable better insight into the interpretation of current patient satisfaction metrics and may allow physicians and hospitals to improve their delivery of care.

The Orthopaedic Foot and Ankle Outcomes Research (OFAR) network: feasibility of a multicenter network for patient outcomes assessment in foot and ankle.

INTRODUCTION: There is an increasing need for orthopaedic practitioners to measure and collect patient-reported outcomes data. In an effort to better understand outcomes from operative treatment, the American Orthopaedic Foot & Ankle Society (AOFAS) established the Orthopaedic Foot and Ankle Outcomes Research (OFAR) Network, a national consortium of foot and ankle orthopaedic surgeons. We hypothesized that the OFAR Network could successfully collect, aggregate, and report patient-reported outcome (PRO) data using the National Institutes of Health (NIH) Patient Reported Outcomes Measurement Information System (PROMIS). METHODS: Ten sites enrolled consecutive patients undergoing elective surgery for 1 of 6 foot/ankle disorders. Outcome instruments were collected preoperatively and at 6 months postoperatively using the PROMIS online system: Foot and Ankle Ability Measure (FAAM), Foot Function Index (FFI), and PROMIS physical function (PF) and pain computerized adaptive tests (CAT). During the 3-month period, 328 patients were enrolled; 249 (76%) had completed preoperative patient-reported outcomes data and procedure-specific data. Of these, 140 (56%) also completed 6-month postoperative patient- reported outcomes data. RESULTS: Ankle arthritis and flatfoot demonstrated consistently worse preoperative scores. Five of 6 disorders showed significant improvement at 6 months on PF CAT and FAAM, 4 of 6 showed improvement on pain interference CAT, and no disorders showed improvement on FFI. Ankle arthritis and flatfoot demonstrated the greatest magnitude of change on most patient-reported outcomes scales. CONCLUSION: We were able to enroll large numbers of patients in a short enrollment period for this preliminary study. Data were easily aggregated and analyzed. Substantial loss of follow-up data indicates a critical area requiring further effort. The AOFAS OFAR Network is undergoing expansion with goals to ultimately facilitate large, prospective multicenter studies and optimize the quality and interpretation of available outcome instruments for the foot and ankle population. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Computerized Adaptive Testing Using the PROMIS Physical Function Item Bank Reduces Test Burden With Less Ceiling Effects Compared With the Short Musculoskeletal Function Assessment in Orthopaedic Trauma Patients.

PURPOSE: Patient-reported outcomes are important to assess effectiveness of clinical interventions. For orthopaedic trauma patients, the short Musculoskeletal Function Assessment (sMFA) is a commonly used questionnaire. Recently, the Patient-Reported Outcome Measurement Information System (PROMIS) PF Function Computer Adaptive Test (PF CAT) was developed using item response theory to efficiently administer questions from a calibrated bank of 124 PF questions using computerized adaptive testing. In this study, we compared the sMFA versus the PROMIS PF CAT for trauma patients. METHODS: Orthopaedic trauma patients completed the sMFA and the PROMIS PF CAT on a tablet wirelessly connected to the PROMIS Assessment Center. The time for each test administration was recorded. A 1-parameter item response theory model was used to examine the psychometric properties of the instruments, including precision and floor/ceiling effects. RESULTS: One hundred fifty-three orthopaedic trauma patients participated in the study. Mean test administration time for PROMIS PF CAT was 44 seconds versus 599 seconds for sMFA (P < 0.05). Both instruments showed extremely high item reliability (Cronbach alpha = 0.98). In terms of instrument coverage, neither instrument showed any floor effect; however, the sMFA revealed 14.4% ceiling effect, whereas the PROMIS PF CAT had no appreciable ceiling effect. CONCLUSIONS: Administered by electronic means, the PROMIS PF CAT required less than one-tenth the amount of time for patients to complete than the sMFA while achieving equally high reliability and less ceiling effects. The PROMIS PF CAT is a very attractive and innovative method for assessing patient-reported outcomes with minimal burden to patients.

Time for a paradigm shift with computerized adaptive testing of general physical function outcomes measurements.

BACKGROUND: Patient-reported outcomes (PRO) are critical to understanding the value of orthopedic treatments. We hypothesized that use of the computerized adaptive testing from a well-characterized physical function item bank would show superiority in assessing all levels of physical function compared to current standard generic physical function outcomes instruments for foot and ankle patients. METHODS: In a population of 126 foot and ankle patients we compared the psychometric properties for three PROs: the Physical Function subscale of the Medical Outcomes General Health Survey (SF-36 PF) version 2, the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) Computerized Adaptive Test (CAT), and the Lower Extremity (LE) CAT. A Rasch item response theory (IRT) model was applied to assess and compare the fit, dimensionality, reliability, validity, and coverage. RESULTS: The unexplained variance for the PF CAT was 3.9% and the LE CAT was 2.1%, suggesting each instrument explained a single concept. The SF-36 PF had more concerning unexplained variance of 7.6%. We found no floor or ceiling effects for the PF CAT, a minimal floor effect (1.6%) but no ceiling effect for the LE CAT, and an 11.1% floor effect and 9.5% ceiling effect for the SF-36 PF. CONCLUSION: Foot and ankle clinicians and researchers interested in measuring patient perceived functional outcomes with a generic instrument should consider using either the PF CAT or the LE CAT rather than the SF-36 PF. Further studies comparing these CATs to anatomic specific instruments are needed. LEVEL OF EVIDENCE: Level I, diagnostic study.

New paradigm for patient-reported outcomes assessment in foot & ankle research: computerized adaptive testing.

BACKGROUND: Accurately measuring, reporting and comparing outcomes is essential for improving health care delivery. Current challenges with available health status scales include patient fatigue, floor/ceiling effects and validity/reliability. METHODS: This study compared Patient Reported Outcomes Measurement Information System (PROMIS)-based Lower Extremity Physical Function Computerized Adaptive Test (LE CAT) and two legacy scales -the Foot and Function Index (FFI) and the sport module from the Foot and Ankle Ability Measure (spFAAM) -for 287 patients scheduled for elective foot and ankle surgery. We documented the time required by patients to complete the instrument, instrument precision, and the extent to which each instrument covered the full range of physical functioning across the patient sample. RESULTS: Average time of test administration: 66 seconds for LE CAT, 130 seconds for spFAAM and 239 seconds for FFI. All three instruments were fairly precise at intermediate physical functioning levels (i.e., Standard Error of Measurement < 0.35), were relatively less precise at the higher trait levels and the LE CAT maintained precision in the lower range while the spFAAM and FFI's had decreased precision. The LE CAT had less floor/ceiling effects than the FFI and the spFAAM. CONCLUSION: The LE CAT showed considerable advantage compared to legacy scales for measuring patient-reported outcomes in orthopaedic patients with foot and ankle problems. CLINICAL RELEVANCE: A paradigm shift to broader use of PROMIS-based CATs should be considered to improve precision and reduce patient burden with patient-reported outcome measuremen foot and ankle patients.

Posttraumatic osteoarthritis: a first estimate of incidence, prevalence, and burden of disease.

Although posttraumatic osteoarthritis (OA) is a common and important entity in orthopedic practice, no data presently exist regarding its prevalence or its relative burden of disease. A population-based estimate was formulated, based on one large institution's experience in terms of its fraction of patients with OA presenting to lower-extremity adult reconstructive clinics with OA of posttraumatic origin. The relative proportion of these patients undergoing total joint replacement provided a basis for extrapolating institutional experience with posttraumatic OA to a populationwide estimate because the numbers of lower-extremity total joint arthroplasty procedures performed were reliably tabulated both within the institution and populationwide. By this methodology, approximately 12% of the overall prevalence of symptomatic OA is attributable to posttraumatic OA of the hip, knee, or ankle. This corresponds to approximately 5.6 million individuals in the United States being affected by posttraumatic OA sufficiently severe to have caused them to present for care by an orthopedic lower-extremity adult reconstructive surgeon. Further, based on the relative prevalence of OA versus rheumatoid arthritis, and their relative impacts as assessed by the SF-36 (Short-Form 36) lower-extremity physical composite scores, about 85.5% of the societal costs of arthritis are attributable to OA. The corresponding aggregate financial burden specifically of posttraumatic OA is Dollars 3.06 billion annually, or approximately 0.15% of the total U.S. health care direct cost outlay.

Surgeon training and complications in total ankle arthroplasty.

BACKGROUND: This study assessed the problems with initial use of ankle arthroplasty by surgeons who were trained by observing the surgeon/inventor (group I), who have completed a structured, hands-on surgical training course (group II), or who were trained during a 1-year foot and ankle fellowship (group III). MATERIALS AND METHODS: The perioperative records of the first 10 cases of nine surgeons were reviewed. We evaluated the 6-month-postoperative standing mortise and lateral radiographs for evidence of syndesmosis union and accuracy of tibial component implantation. Three surgeons were each in group I, group II, and group III. Average patient age at time of surgery was similar. Ankle arthritis was classified as rheumatoid arthritis (RA) or osteoarthritis (OA) as follows: group I (7 RA, 23 OA), group II (7 RA, 23 OA), and group III (3 RA, 27 OA). RESULTS: In group I, there were nine intraoperative complications, four postoperative wound dehiscences, and three postoperative deep infections. Radiographic evaluation of the 26 cases with adequate postoperative roentgenograms revealed that 10/26 (38%) had a delayed union of the syndesmosis. In group II, there were six intraoperative complications and two postoperative wound problems: an early anterior wound problem and a delayed lateral wound breakdown. Radiographic evaluation of the 26 cases with adequate postoperative roentgenograms revealed that 13/26 (50%) had a delayed union of the syndesmosis. In group III, there were four intraoperative complications and four postoperative wound problems--all healed with local supportive care with one requiring lateral hardware removal. Radiographic evaluation of the 26 cases with adequate postoperative roentgenograms revealed that 5/30 (17%) had a delayed union of the syndesmosis. The initial series from these three groups are statistically indistinguishable with respect to rates of complications, revisions, or malalignment. CONCLUSION: No identified training method had a statistically demonstrable positive impact on preparing surgeons for performing total ankle replacement. Some of these findings are likely generic for total ankle replacements and not restricted to any class or design of implant. Surgeon initial use of total ankle replacement needs to be done with caution and serious consideration.

Outcome of lower extremity malignancy survivors treated with transfemoral amputation.

OBJECTIVE: To determine outcomes of surviving patients who underwent transfemoral amputation as part of treatment for lower extremity malignancy at a mean 15 years postoperatively, with a minimum 2-year follow-up. DESIGN: Retrospective, case control. SETTING: Tertiary care university medical center. PATIENTS: Thirty-five of 38 consecutively admitted patients free of metastatic disease managed with transfemoral amputation as part of treatment of a lower extremity bone and/or soft tissue malignancy between 1966 and 1997 at 1 institution. The control group included 35 age- and gender-matched subjects recruited from the local driver's license office. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Musculoskeletal Function Assessment (MFA), Short Form-12 General Health Status Survey (SF-12), physical performance battery, cost, and demographic data. RESULTS: Controls showed superior scores as measured by the MFA (P < .0001), the physical component summary of the SF-12 (P = .0002), and the physical performance battery (P < .0001), but had inferior scores on the mental component summary of the SF-12 (P < .0001). With the numbers available, no differences were found between study and control subjects in terms of employment rate (P = .51), education level (P = .66), income level (P =.44), marital status (P = .79), incidence of self-reported health problems (P = .14), and alcohol (P =.42) and tobacco (P = .82) use. Ten patients were included in the cost analysis; the mean cost to obtain and maintain a lower extremity prosthesis was $4225 per year (range, 623 dollars-8517 dollars). CONCLUSIONS: Although the decrease in physical performance was anticipated in the study group, the group differed very little from the control population in terms of employment, education level, income, marital and home status, incidence of self-reported health problems, incidence of self-reported depression, and alcohol and tobacco use. Also, the long-term cost of maintaining a lower extremity prosthesis is noted.