Are Patient Reported Outcome Measurement Information System scales responsive in patients attending physical therapy with foot and ankle diagnoses?

BACKGROUND

Patient-reported outcomes (PROs) have been used to provide insight into the patient experience while uncovering an opportunity to improve patient care. Current studies document responsiveness of outcomes using the Patient Reported Outcome Measurement Information System (PROMIS) for a variety of orthopedic problems but are not specific to a physical therapy interval of care.

PURPOSE

The main purpose of this study was to examine responsiveness of the PROMIS Physical Function (PF) and Pain Interference (PI) scales across an interval of care for physical therapy in patients with foot and ankle conditions.

METHODS

Adult records (299 records, averaged 45.1 ± 15.4 years; 61% female) were assessed. Comparisons between pre- and post-physical therapy intervals of care were evaluated using a repeated-measures ANOVA, and the effect size was reported using Cohen's d.

RESULTS

PROMIS PF scores significantly improved from 38.5 ± 8.8 to 45.2 ± 9.1 (6.6; p < .001; Cohen's d = 1.0). PROMIS PI scores significantly improved from 56.8 ± 8.8 to 53.0 ± 9.8 (-3.8; p < .001; Cohen's d = 0.52).

CONCLUSIONS

The person-centered PROMIS PF and PI outcome measures were responsive to change following an interval of care in physical therapy for a large sample of orthopedic patients with foot and ankle diagnoses. The magnitude of change was dependent on starting score and diagnosis.

Do clinical criteria based on PROMIS outcomes identify acceptable symptoms and function for patients with musculoskeletal problems

BACKGROUND

Understanding how symptoms influence patient judgements of their health informs providers where to direct care. Patient reported physical outcomes (physical function, pain interference) and self-efficacy of symptom management (SEsm)) predict a patient's health state (i.e. patient acceptable symptom state (PASS)). However, it's unclear if therapist should consider a psychological outcome like SEsm separately or combine this outcome with other physical outcomes for clinical decisions.

OBJECTIVE

To determine if patient reported outcome information system (PROMIS) SEsm scale when combined with PROMIS physical function or pain interference is able to accurately predict a patient's health state defined by PASS.

METHODS

One hundred ninety-six patients (initial sample (n = 94) and separate sample (n = 102)) were surveyed by phone after care for a musculoskeletal problem. Patients completed PASS, PROMIS physical function, pain interference and SEsm outcomes. Logistic regression was used to estimate odds ratios (OR) for determining PASS in the initial sample. Criteria for determining PASS developed from the regression analysis were applied to a separate sample to assess accuracy. Accuracy for PASS status were also assessed at 1-7 days and 45-60 days.

RESULTS

Three combinations including SEsm/pain interference and SEsm/physical function showed significant OR's (<0.1) and varied from 2.5 to 4.2 for predicting PASS status. Criteria to predict PASS in the separate sample at 1-7 days and 45-60 days showed accuracies from 74.5% to 83.6%.

CONCLUSION

This study demonstrates that utilizing SEsm in combination with common physical outcomes used to assess patients with musculoskeletal diagnoses improves prediction of a patient's acceptable level of symptoms and activity.

Improving Interpretation of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Scale for Specific Tasks in Community-Dwelling Older Adults

BACKGROUND AND PURPOSE

New generic patient-reported outcomes like the Patient-Reported Outcomes Measurement Information System (PROMIS) are available to physical therapists to assess physical function. However, the interpretation of the PROMIS Physical Function (PF) T-score is abstract because it references the United States average and not specific tasks. The purposes of this study were to (1) determine convergent validity of the PROMIS PF scale with physical performance tests; (2) compare predicted performance test values to normative data; and (3) identify sets of PROMIS PF items similar to performance tests that also scale in increasing difficulty and align with normative data.

METHODS

Community-dwelling older adults (n = 45; age = 77.1 ± 4.6 years) were recruited for this cross-sectional analysis of PROMIS PF and physical performance tests. The modified Physical Performance Test (mPPT), a multicomponent test of mostly timed items, was completed during the same session as the PROMIS PF scale. Regression analysis examined the relationship of mPPT total and component scores (walking velocity, stair ascent, and 5 times sit to stand) with the PROMIS PF scale T-scores. Normative data were compared with regression-predicted mPPT timed performance across PROMIS PF T-scores. The PROMIS PF items most similar to walking, stair ascent, or sit to stand were identified and then PROMIS PF model parameter-calibrated T-scores for these items were compared alongside normative data.

RESULTS AND DISCUSSION

There were statistically significant correlations (r = 0.32-0.64) between PROMIS PF T-score and mPPT total and component scores. Regression-predicted times for walking, stair ascent, and sit-to-stand tasks (based on T-scores) aligned with published normative values for older adults. Selected PF items for stair ascent and walking scaled well to discriminate increasing difficulty; however, sit-to-stand items discriminated only lower levels of functioning.

CONCLUSIONS

The PROMIS PF T-scores showed convergent validity with physical performance and aligned with published normative data. While the findings are not predictive of individual performance, they improve clinical interpretation by estimating a range of expected performance for walking, stair ascent, and sit to stand. These findings support application of T-scores in physical therapy testing, goal setting, and wellness plans of care for community-dwelling older adults.

Role of Patient-Reported Outcome Measures on Predicting Outcome of Bunion Surgery

BACKGROUND

Prior studies have suggested preoperative patient-reported outcome scores could predict patients who would achieve a clinically meaningful improvement with hallux valgus surgery. Our goal was to determine bunionectomy-specific thresholds using Patient-Reported Outcomes Measurement Information System (PROMIS) values to predict patients who would or would not benefit from bunion surgery.

METHODS

PROMIS physical function (PF), pain interference (PI), and depression assessments were prospectively collected. Forty-two patients were included in the study. Using preoperative and final follow-up visit scores, minimally clinically important differences (MCID), receiver operating characteristic (ROC) curves, and area under the curve (AUC) analyses were performed to determine if preoperative PROMIS scores predicted achieving MCID with 95% specificity or failing to achieve an MCID with 95% sensitivity.

RESULTS

PROMIS PF demonstrated a significant AUC and likelihood ratio. The preoperative threshold score for failing to achieve MCID for PF was 49.6 with 95% sensitivity. The likelihood ratio was 0.14 (confidence interval, 0.02-0.94). The posttest probability of failure to achieve an MCID for PF was 94.1%. PI and depression AUCs were not significant, and thus thresholds were not determined.

CONCLUSION

We identified a PF threshold of 49.6, which was nearly 1 standard deviation higher than previously published. If a patient is hoping to improve PF, a patient with a preoperative t score >49.6 may not benefit from surgery. This study also suggests the need for additional research to delineate procedure-specific thresholds.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Prevalence of Patellar Tendinopathy and Patellar Tendon Abnormality in Male Collegiate Basketball Players: A Cross-Sectional Study

CONTEXT

Patellar tendinopathy (PT) is a degenerative condition known to affect athletes who participate in sports such as basketball and volleyball. Patellar tendinopathy is a challenging condition to treat and may cause an athlete to prematurely retire from sport. The prevalence of PT in male collegiate basketball players is unknown.

OBJECTIVE

To determine the prevalence of PT and patellar tendon abnormality (PTA) in a population of male collegiate basketball players.

DESIGN

Cross-sectional study.

SETTING

National Collegiate Athletic Association Divisions II and III, National Association of Intercollegiate Athletics, and Northwest Athletic Conference male collegiate basketball teams were assessed in a university laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Ninety-five male collegiate basketball players (age = 20.0 ± 1.7 years).

MAIN OUTCOME MEASURE(S)

A diagnostic ultrasound image of an athlete's patellar tendon was obtained from each knee. Patellar tendinopathy was identified based on a player's symptoms (pain with palpation) and the presence of a hypoechoic region on an ultrasonographic image.

RESULTS

A majority of participants, 53 of 95 (55.8%), did not present with pain during palpation or ultrasonographic evidence of PTA. Thirty-two basketball players (33.7%) displayed ultrasonographic evidence of PTA in at least 1 knee; 20 of those athletes (21.1%) had PT (pain and tendon abnormality). Nonstarters were 3.5 times more likely to present with PTA (odds ratio = 3.5, 95% confidence interval = 1.3, 9.6; P = .017) and 4 times more likely to present with PT (odds ratio = 4.0, 95% confidence interval = 1.1, 14.8; P = .038) at the start of the season.

CONCLUSIONS

One in 3 male collegiate basketball players presented with either PT or PTA. Sports medicine professionals should evaluate basketball athletes for PT and PTA as part of a preseason screening protocol.

Do Patient Reported Outcome Measurement Information System (PROMIS) Scales Demonstrate Responsiveness as Well as Disease-Specific Scales in Patients Undergoing Knee Arthroscopy?

BACKGROUND

The Patient Reported Outcomes Information System (PROMIS) is an efficient metric able to detect changes in global health.

PURPOSE

To assess the responsiveness, convergent validity, and clinically important difference (CID) of PROMIS compared with disease-specific scales after knee arthroscopy.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

A prospective institutional review board-approved study collected PROMIS Physical Function (PF), PROMIS Pain Interference (PI), International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) results in patients undergoing knee arthroscopy. The change from preoperative to longest follow-up was used in analyses performed to determine responsiveness, convergent validity, and minimal and moderate CID using the IKDC scale as the anchor.

RESULTS

Of the 100 patients enrolled, 76 were included. Values of the effect size index (ESI) ranged from near 0 to 1.69 across time points and were comparable across scales. Correlations of the change in KOOS and PROMIS with IKDC ranged from r values of 0.61 to 0.79. The minimal CID for KOOS varied from 12.5 to 17.5. PROMIS PF and PI minimal CID were 3.3 and -3.2. KOOS moderate CID varied from 14.3 to 18.8. PROMIS PF and PI moderate CID were 5.0 and -5.8.

CONCLUSION

The PROMIS PF and PI showed similar responsiveness and CID compared with disease-specific scales in patients after knee arthroscopy. PROMIS PI, PROMIS PF, and KOOS correlations with IKDC demonstrate that these scales are measuring a similar construct. The ESIs of PROMIS PF and PI were similar to those of KOOS and IKDC, suggesting similar responsiveness at 6 months or longer (ESI >1.0). Minimum and moderate CID values calculated for PROMIS PF and PI using IKDC as an anchor were sufficiently low to suggest clinical usefulness.

CLINICAL RELEVANCE

PROMIS PF and PI can be accurately used to determine improvement or lack thereof with clinically important changes after knee arthroscopy.

COMPARISON OF NON-CONTACT AND CONTACT TIME-LOSS LOWER QUADRANT INJURY RATES IN MALE COLLEGIATE BASKETBALL PLAYERS: A PRELIMINARY REPORT

BACKGROUND

Male collegiate basketball (BB) players are at risk for musculoskeletal injury. The rate of time-loss injury in men's collegiate BB, for all levels of National Collegiate Athletic Association (NCAA) competition, ranges from 2.8 to 4.3 per 1000 athletic exposures (AE) during practices and 4.56 to 9.9 per 1000 AE during games. The aforementioned injury rates provide valuable information for sports medicine professionals and coaching staffs. However, many of the aforementioned studies do not provide injury rates based on injury mechanism, region of the body, or player demographics.

HYPOTHESIS/ PURPOSE

The purpose of this study is two-fold. The first purpose of this study was to report lower quadrant (LQ = lower extremities and low back region) injury rates, per contact and non-contact mechanism of injury, for a cohort of male collegiate basketball (BB) players. The second purpose was to report injury risk based on prior history of injury, player position, and starter status.

STUDY DESIGN

Prospective, descriptive, observational cohort.

METHODS

A total of 95 male collegiate BB players (mean age 20.02 ± 1.68 years) from 7 teams (NCAA Division II = 14, NCAA Division III = 43, NAIA = 21, community college = 17) from the Portland, Oregon region were recruited during the 2016-2017 season to participate in this study. Each athlete was asked to complete an injury history questionnaire. The primary investigator collected the following information each week from each team's athletic trainer: athletic exposures (AE; 1 AE = game or practice) and injury updates.

RESULTS

Thirty-three time-loss LQ injuries occurred during the study period. The overall time-loss injury rate was 3.4 per 1000 AE. Division III BB players had the highest rates of injury. There was no difference in injury rates between those with or without prior injury history. Guards had a significantly greater rate of non-contact time-loss injuries (p = 0.04).

CONCLUSIONS

Guards experienced a greater rate of LQ injury than their forward/center counterparts. Starters and athletes with a prior history of injury were no more likely to experience a non-contact time-loss injury than nonstarters or those without a prior history of injury. These preliminary results are a novel presentation of injury rates and risk for this population and warrant continued investigation.

LEVEL OF EVIDENCE

2.

Can Women Live with More Symptoms than Men?

Category:

Other

Introduction/Purpose:

Over the last few years an increasing focus has been directed to define cut-off points for important health improvement. Minimal clinically important difference (MCID) values have traditionally been used to determine if a statistical change translates to a clinical improvement to the patient. Although MCID is helpful, it may be even more important to identify if the current treatment is adequate or that the patient has achieved an acceptable symptom state (symptoms minimal enough to live with). The purpose of this study was to determine if gender influenced patient reported outcomes (patient acceptable symptom state (PASS) and PROMIS Physical Function, Pain Interference and Depression) in patients with foot and ankle problems.

Methods:

Prospectively collected PROMIS and PASS were identified for 450 surgical patients (Males=126, Females=324). The CPT codes, gender %, age and follow up were recorded (Table 1). To assure the overall recovery experienced by females and males was similar, aggregate PROMIS scores were compared using ANOVA analysis. The average PROMIS t-scores were comparable and without clinically meaningful differences between gender groups. The ability of each PROMIS scale to predict PASS status was determined using receiver operator curves (ROC). The area under the curve (AUC) and thresholds approximating 95% sensitivity/specificity for males and females were assessed for each PROMIS domain. AUC values below 0.7 are not considered clinically useful. Differences AUC or approximating 95% sensitivity/specificity thresholds by gender would support the hypothesis that PASS status is influenced by gender.

Results:

There were significant differences in the AUC for gender suggesting PROMIS scores are better predictors of PASS for females than males however there were only minor differences in near 95% sensitivity/specificity PROMIS threshold values by gender. The AUC values for females were higher than for males for each PROMIS scale (Figure 1). The thresholds PROMIS PF, PI and Dep for males and females are in Table 1. The thresholds for PROMIS PF to determine PASS yes was lower for females compared to males; while the thresholds for PROMIS PI to determine PASS yes were similar between males and females. This suggests that women accept lower function as an acceptable status than men. Men and women accept similar pain thresholds as PASS yes.

Conclusion:

PROMIS domains more accurately predict PASS status in females based on the AUC. Females are more likely to judge their physical abilities as acceptable at a lower PROMIS PF threshold value compared to males. Despite these gender differences, males and females both identify a PROMIS threshold (PF and PI) that was near the average of the US population (t-score 50). The lower AUC for males may indicate that males judge any symptoms as unacceptable and use a broader frame of reference than isolatedly perceived physical function and pain interference when judging whether their physical abilities and symptoms are acceptable.

Subtle Cavus Deformities

Category:

Sports

Introduction/Purpose:

Lateral ankle ligament injuries are common conditions accounting for 25% of musculoskeletal injuries. Prior reports have found increased risk of failed lateral ankle reconstruction in those with a subtle cavus deformity, and therefore, correcting the deformity is often advocated. However, other studies have been unable to identify subtle cavus deformity as a clear risk factor for recurrent injury. The purpose of this study was to 1) compare PROMIS physical function (PF), pain interference (PI), and depression scores in patients with subtle cavus deformities to those without deformity who underwent lateral ankle ligament reconstruction, 2) compare PROMIS scores in allograft and modified Brostrom-Gould (BG) reconstructions in those with subtle cavus, and 3) to evaluate for any post-operative complications in those with subtle cavus.

Methods:

PROMIS CAT scores were prospectively obtained from patients evaluated in a specialty foot and ankle clinic between February 2015 and December 2017. Using CPT codes, 145 patients who underwent lateral ankle ligament reconstruction were identified. Exclusion criteria consisted of less than three-month follow-up, incomplete PROMIS scores, or multiple surgeries unrelated to the reconstruction during the follow-up period. A total of 78 patients were included in the study. Pre- and post-operative PROMIS PF, PI, and depression were collected. Patients were then divided into two groups: subtle cavus foot (n=23) and non-cavus foot (n=55). A foot was considered cavus based on physical exam and previously published radiographic parameters. The cavus group was further subdivided into allograft reconstruction and BG reconstruction. Post-operative complications were also recorded. Student t-tests were used to evaluate for differences in PF, PI, and depression t-scores in cavus vs. non-cavus groups as well as allograft vs. BG.

Results:

The average follow-up was 28.59+/-13.27 weeks in the cavus and 29.77+/-16.15 weeks in the non-cavus group (p=0.76). There were no differences in pre-operative PF, PI, or depression t-scores between the two groups (p>0.05). The cavus group had significantly better post-operative PF compared to the non-cavus group (49.24+/-8.14 vs. 43.17+/-6.64, p=0.001). PI was also better in the cavus group (51.12+/-8.33) compared to the non-cavus group (55.09+/-9.45), however not statistically significant (p=0.08). There were no differences in post-operative depression (p=0.58). When subdividing the cavus group, allograft reconstruction (49.49+/-7.48) had better post-operative PI t-scores compared to BG (57.17+/-8.16, p=0.04). In the cavus group, there were no instances of recurrent instability; one patient required a repeat ankle arthroscopy for debridement. One patient in the non-cavus group developed recurrent instability.

Conclusion:

Patients with subtle cavus deformity undergoing lateral ankle ligament reconstruction had significantly higher post-operative PROMIS PF t-scores compared to those without deformity and a trend towards improved pain post-operatively. When subdividing the subtle cavus group, allograft reconstruction demonstrated better PI scores post-operatively, and thus may be a more favorable technique in patients who have a subtle cavus deformity. Though longer follow-up is needed, our study suggests that patients with subtle cavus deformities may not require a more complex reconstruction with osteotomies to correct their deformity in order to achieve clinically meaningful improved outcomes.

Midfoot power during walking and stair ascent in healthy adults

Category:

Midfoot/Forefoot

Introduction/Purpose:

Intrinsic foot muscles have the capacity to attenuate and reverse arch deformation under loaded conditions. This function is proposed to be an important component in generating the midfoot power and stability requisite for gastroc-soleus muscle action at the ankle during forward propulsion. Synergistic activation of intrinsic foot muscles is proposed to function as a ‘foot core’ during weightbearing activity that is analogous to the function of the smaller muscles at the spine. If this theory were sound, midfoot power would be expected to increase, potentially in proportion to ankle power, as the muscular demand of a task increases. The purpose of this study was to explore the nature and behavior of midfoot and ankle power during walking and stair ascent in healthy adults.

Methods:

Twelve healthy adults [Mean (SD): Age 31.3 (4.9) years; BMI 25.2 (3.4) Kg/m2; 50% female] walked, ascended a standard step, and ascended a high step. An electromagnetic sensor motion capture system and force plate were used to record multi-segment foot motion and ground reaction force data. Subject-specific three segment foot models (tibia, rearfoot, forefoot) were derived. Inverse dynamic calculations were performed to obtain ankle and midfoot positive total power. Positive total power, calculated as the sum of positive power (joint torque x segmental velocity) after heel off, reflects the entire amount of ankle or midfoot push-off power generated for a given task. The proportion of midfoot to ankle positive total power was also calculated. Multiple one-way repeated measures ANOVAs were conducted to evaluate differences in power variables across tasks. Bonferroni adjusted pairwise comparisons were made to assess differences in main effects. Effect sizes between conditions were also examined (Cohen’s d).

Results:

Significant main effects were found for both ankle and midfoot positive total power [ankle F = 29.8 (p < 0.01); midfoot F = 63.1 (p < 0.01)]. Pairwise comparisons revealed that total power significantly increased across each activity at both the ankle (d range: 0.09 - 2.3) and midfoot (d range: 1.4 - 2.9) [all p < 0.05]. Interestingly, a main effect was not observed in the proportion of midfoot to ankle total power across activity [F = 1.2 (p = 0.33)] (Figure 1).

Conclusion:

The findings of this study provide preliminary support for the idea of a midfoot ‘foot core’ system. While increased ankle and midfoot power is required as the muscular demand of activity increases from walking to standard step and high step ascent, the proportion of midfoot to ankle total power remains the same. Study findings may assist practitioner understanding in addressing regional foot muscle imbalances and advancing patients to higher-level functional activities.

Can Patient Reported Outcomes Guide Therapy Needs in Foot and Ankle Patients?

Category:

Other

Introduction/Purpose:

The patient acceptable symptom state (PASS) is a validated question establishing if patients activity and symptoms are at a satisfactory low level for pain and function. Surprisingly, ~20% of foot and ankle patients at their initial visit present for care with an acceptable symptom state (i.e. PASS yes). These patients are important to identify to prevent over treatment and avoid excessive cost. It is also unclear what health domains (Pain Interference (PI), Physical Function (PF), or Depression (Dep)) influence a patients judgement of their PASS state (i.e. why they are seeking treatment). The purpose of this analysis is to document the prevalance of PASS state and determine the health domains that discriminate PASS patients and predict PASS state at the initiation of rehabilitation.

Methods:

Patient reported outcomes measurement information system (PROMIS) computer adaptive test (CAT) scales PF, pain PIand Dep and PASS ratings starting in summer 2017 were routinely collected for patient care. Of 746 unique patients in this data set, 114 patients had ICD-10 codes that were specific to the foot and ankle. Average age was 51years (±18) and 54.4% were female. Patients were seen an average of 19.8(±15.9) days from their referral and were billed as low (51.7%), moderate (44.7%) and high complexity (2.7%) evaluations per current procedural code (CPT) visits. ANOVA models were used to evaluate differences in PROMIS scales by PASS state (Yes/No). The area under receiver operator curve (AUC) was used to determine the predictive ability of each PROMIS scale to determine a PASS state. Thresholds for near 95% specificity were also calculated for a PASS Yes state for each PROMIS scale.

Results:

The prevalance of PASS Yes patients was 13.2% (15/114). Pass Yes patients were significantly better by an average of 7.2 to 8.0 points across all PROMIS health domains compared to PASS No patients (Table 1). ROC analysis suggested that Dep (AUC=0.73(0.07) p=0.005) was the highest predictor of PASS status followed by PI (AUC=0.70(0.08) p=0.012) and PF (AUC=0.69(0.07) p=0.18). The threshold PROMIS t-score values for determining PASS Yes with nearest 95% specificity were PF = 51.9, PI = 50.6, and Dep = 34.

Conclusion:

Surprising, yet consistent with previous data, 13.2% of patients at their initial physical therapy consultation rated themselves at an acceptable level of activity and symptoms. Health domains of physical function, pain interference, and depression were better in these patients and showed moderate ability (AUC~0.7) to identify these patients. The PROMIS thresholds suggest patients are identified by pain and physical function equal to the average of the US population (PROMIS T-Score ~50) and extremely low depression scores (34). Clinically it is important to recognize these patients and purposefully provide treatments that reinforce their self efficacy and prevent unnecessary costly treatments.

Can Foot Exercises and Going Barefoot Improve Function, Muscle Size, Foot Pressure During Walking and Qualitative Reports of Function in People with Flat Foot?

Category:

Midfoot/Forefoot

Introduction/Purpose:

Specific exercises to train foot muscles for barefoot running (i.e. doming seated[DS] and standing[DSt]) and post foot and ankle injury (i.e. seated plantar flexion and inversion[SPFI]) are common. Exercise programs specifically for the foot claim improvement in foot posture (foot posture index [FPI]) and foot strength. However, rigorous assessment of foot function as a result of exercise is lacking (i.e. foot posture, strength, and plantar pressure). Further, no studies specifically address patients with flat foot. The purpose of this case series study was to assess the immediate effects of an 8-week foot exercise and barefoot weight bearing program on clinical and biomechanical measures of foot function.

Methods:

Thirty three participants, 23 with a severe flatfoot (SFF), measured by FPI (> 6/12, average = 9.4±1.5, age=28.9 ±11.0) and 10 age/gender matched controls (AMC) with a normal foot (FPI average=4.6±1.5, age = 29.8±7.8) participated. The SFF group completed 4 foot exercises (DS, DSt, SPFI, and toe spreading) and spent 2 hours/day barefoot weight bearing 5 days/week for 8 weeks. The SFF group was tested pre- and post exercise and the AMC group once. Testing included plantar pressure during walking (cadence 120 bpm), abductor halluces cross sectional area(CSA) using diagnostic ultrasound, paper pull test (PPT) quantified 1st metatarsophalangeal joint(MTP) flexion strength using a force plate, and heel raises (repetitions and heel height). ANOVA models and T-tests were used to assess the effects of pre- to post exercise and make comparisons between the SFF group and the AMC group. Post exercise interviews were transcribed and subjected to word count analysis.

Results:

Although no calf training was included, heel rise repetition (Right: Pre=28.0 to Post 35.0, Left: Pre=30.6 Post= 38.2) and heel height (Increased Right: 1.7 cm, Left: 1.8 cm) improved (Figure 1). The PPT test indicated increased 1st MTP flexion force post exercise bilaterally (Right p=0.002, Left p=0.007). Consistent with increased force of the PPT, abductor halluces muscle CSA increased bilaterally (Right & Left = 0.3 cm2 or 12.5%). However, plantar pressures were not different post exercise (p>0.05). Post exercise the SFF group and AMC group were similar across variables(p>0.05). Compliance logs indicated 87.7% completion of prescribed exercises and 111% of time targeted barefoot weight bearing. The top 6 words mentioned in post exercise interviews were: exercise, time, stronger, standing, hard, and easy.

Conclusion:

This is the first data to demonstrate that foot only exercises have a significant influence on ankle plantar flexion function (i.e. increased heel rise repetition and height) and patient qualitative assessments of their foot. The argument that this increase in ankle function derives from the training effects within the foot is supported by significantly higher 1st MTP force (increased PPT test) and increased cross sectional area of the abductor halluces muscle. Despite having significant flat foot deformity participants enhanced their foot and ankle function. This suggests that other foot problems with similar deformity may also benefit from exercise.

Can Understanding Provider Expectations Improve Provider Adoption of Patient Reported Outcomes?

Category:

Other

Introduction/Purpose:

New instruments like the Patient Reported Outcome Information System (PROMIS) minimize the burden to patients and providers addressing significant barriers to adoption. Despite these advances provider adoption remains lackluster. Models of technology adoption suggest adoption is more likely to occur when PRO’s directly improve patient care (performance expectancy) and it’s easy to implement (effort expectancy). Problems with effort expectancy are dealt with by training and improving logistics (i.e. eHR presentation, alerts), where performance expectancy is addressed through research (i.e. validation of thresholds). The purposes of this study were to: 1) evaluate the proportion of orthopedic rehabilitation providers who use PRO’s and how they use them; And, 2) to determine if performance expectancy, effort expectancy or provider burnout are related to provider use.

Methods:

Fifty rehabilitation providers (physical therapist and athletic trainers) anonymously completed the electronic PRO Adoption Survey. Participants were 23.4±5.8 years old and 54% were female. The purpose of the PRO Adoption Survey is to track adoption across health systems. The first section of the PRO Adoption survey includes whether providers use PRO’s and asks them to detail how they use them (Table 1). A factor analysis supported the use of sets of questions to determine performance expectancy and effort expectancy (Table 1). Performance expectancy captures the health benefits the provider expects to experience. Effort expectancy captures the provider’s expectations of how easy it will be to implement PRO tools. The validated Maslach-2 burnout scale (BO) was included as another a factor that may influence adoption. Proportions and chi square tests were used to describe provider use of PRO’s and its relationship with performance expectancy, effort expectancy, and burnout.

Results:

The profile of PRO use by rehabilitation professionals is that a majority know about PRO’s (86%) however only 34% utilize PRO’s during clinic visits (Table 1). The most common PRO used is PROMIS (83%), followed by generic measures (41%) and disease specific (29%) measures. Type of use indicated the most common use was to make clinical decisions (71%) with relatively few using it for research (12%). Interestingly, 47% of PRO users review data with patients. The average responses for performance expectancy were 3.9 ± 0.1. The average responses for effort expectancy were 3.2 ± 0.2 or “neutral”. The average BO score was 4.6 ± 1.0. Chi square analysis suggested performance expectancy, effort expectancy, and burn out were not significantly associated with provider use.

Conclusion:

PROMIS scales are currently available in the electronic medical record(eMR) leading to high use (86%) by current PRO users (34%). High performance expectancy scores (~4/5) and low BO suggest providers can be motivated to use PRO’s. However, providers are neutral (~3/5) on how easy PRO’s would be to implement. Also, lower scores for performance expectancy associated with “aggregate” PRO data (only 54% marked “Agree” for this item) suggests training on specific uses of aggregate data are also indicated. These data detail the real issues providers need addressed to effectively capitalize on the benefits of PRO’s to improve clinical care.

Identifying Foot and Ankle Patients at Risk to Fall Based on Patient Reported Outcomes Assessments

Category:

Other

Introduction/Purpose:

Each year approximately 30-40% of people over the age of 65 fall. Approximately one half of these falls result in an injury with the estimated annual direct medical costs of $30 billion. Pain, mobility issues, neuropathy and post-operative weight bearing limitations make foot and ankle patients particularly vulnerable to falls. Current approaches to determine at risk patients are cumbersome and time consuming requiring performance testing and “hands on” clinical assessment. The efficiency of obtaining PRO, such as PROMIS, in the clinical arena has been well documented. The purpose of this study is determine if patient reported outcomes (PROMIS) can identify orthopaedic and specifically foot and ankle patients at risk to fall.

Methods:

Prospective patient reported outcomes (PROMIS CAT physical function, pain interference and depression and CMS fall risk assessment questions) and patient demographics were collected for all patients at each clinic visit from an academic orthopaedic multi-specialty practice between January 2015 and November 2017. Standardized yes/no validated self-reported fall risk questions include: “Have you fallen in the last year?” and “Do you feel you are at risk of falling?” Histograms, t-tests, confidence intervals and effect size were used to determine the fall risk “YES” patients were different than the “NO” for ALL orthopaedic patients and specifically foot and ankle patients. Logistic Regression was used to determine if age, gender, height, weight, and PROMIS scales predicted self-reported falls risk.

Results:

94,761 orthopaedic patients comprising 315,273 visits (44% male, mean age 53.7+/-17 years) and 13,720 foot/ankle patients comprising 33,480 visits (37% male, mean age 52.7+/-16.1 years) had complete data for analysis. Table 1 provides the means/SD/p-values/effect sizes for patient self-identifying at risk to fall stratified by PROMIS PF/ PI/Dep t-scores. Although all PROMIS scores demonstrated significant impairment between patients at risk designation (yes/no), PROMIS PF had the largest effect size for ALL Ortho and FOOT AND ANKLE patients (0.8 and 0.7 respectively). Patients who are at risk to fall have PROMIS PF t-scores >1.5 lower than the United States normative population while the patients not at risk are less <1 SD. In the adjusted regression models gender and PROMIS PF had the largest coefficients.

Conclusion:

Falls are a major threat to quality of life and independence yet prevention/treatment strategies are difficult to implement across a health system. There is also a tremendous societal cost with orthopaedic surgeons often the recipient of these debilitated patients. PROMIS assessments are part of the AOFAS OFAR initiative to track patient recovery with treatment and can additional be used to fulfill a quality indicator requirement by CMS. This study demonstrates these assessments (PROMIS threshold values) can also be linked to self-report falls risk (yes/no) and may identify patients at risk with no face to face time required from the provider.

Does Identifying Provider Expectations Improve Adoption of Patient Reported Outcomes?

Category:

Other

Introduction/Purpose:

New instruments like the Patient Reported Outcome Information System (PROMIS) minimize the burden to patients and providers addressing significant barriers to adoption. Despite these advances provider adoption remains lackluster. Models of technology adoption suggest adoption is more likely to occur when PRO’s directly improve patient care (performance expectancy) and it’s easy to implement (effort expectancy). Problems with effort expectancy are dealt with by training and improving logistics (i.e. eHR presentation, alerts), where performance expectancy is addressed through research (i.e. validation of thresholds). The purposes of this study were to: 1) evaluate the proportion of orthopedic rehabilitation providers who use PRO’s and how they use them; And, 2) to determine if performance expectancy, effort expectancy or provider burnout are related to provider use.

Methods:

Fifty rehabilitation providers (physical therapist and athletic trainers) anonymously completed the electronic PRO Adoption Survey. Participants were 23.4±5.8 years old and 54% were female. The purpose of the PRO Adoption Survey is to track adoption across health systems. The first section of the PRO Adoption survey includes whether providers use PRO’s and asks them to detail how they use them (Table 1). A factor analysis supported the use of sets of questions to determine performance expectancy and effort expectancy (Table 1). Performance expectancy captures the health benefits the provider expects to experience. Effort expectancy captures the provider’s expectations of how easy it will be to implement PRO tools. The validated Maslach-2 burnout scale (BO) was included as another a factor that may influence adoption. Proportions and chi square tests were used to describe provider use of PRO’s and its relationship with performance expectancy, effort expectancy, and burnout.

Results:

The profile of PRO use by rehabilitation professionals is that a majority know about PRO’s (86%) however only 34% utilize PRO’s during clinic visits (Table 1). The most common PRO used is PROMIS (83%), followed by generic measures (41%) and disease specific (29%) measures. Type of use indicated the most common use was to make clinical decisions (71%) with relatively few using it for research (12%). Interestingly, 47% of PRO users review data with patients. The average responses for performance expectancy were 3.9 ± 0.1. The average responses for effort expectancy were 3.2 ± 0.2 or “neutral”. The average Maslach BO score was 4.6 ± 1.0. Chi square analysis suggested performance expectancy, effort expectancy, and burn out were not significantly associated with provider use.

Conclusion:

PROMIS scales are currently available in the electronic medical record leading to high use (83%) by PRO users(34%). High performance expectancy scores (~4/5) and low BO suggest providers can be motivated to use PRO’s. The survey also suggests that providers are neutral(~3/5) on how easy PRO’s would be to implement. Lower scores for performance expectancy associated with “aggregate” PRO data (only 54% marked “Agree” for this item) suggests training on specific uses of aggregate data are also indicated. These data detail the real issues providers need addressed to effectively capitalize on the benefits of PRO’s to improve clinical care.

Validity of Visual Assessment of Sit to Stand After Hip Fracture

BACKGROUND AND PURPOSE

When treating older adults post-hip fracture, physical therapists routinely assess the sit-to-stand (STS) task using observational analysis. Studies have demonstrated that significant movement asymmetries in ground reaction force production of the fractured lower limb persist during STS, even though individuals may rise independently. To date, the validity of therapist judgments of lower limb force during STS has not been addressed. The purpose of this observational cohort study was to determine the accuracy of physical therapists' observational assessments of STS for detecting the involved limb and its ground reaction force contribution in older adults post-hip fracture.

METHODS

Eighteen home health physical therapists assessed 10 videotapes of older adults post-hip fracture rising from sitting and judged the side of involvement and the amount of ground reaction force generated by the fractured lower limb. Each videotape was synchronized with its respective force data. A wide spectrum of asymmetry in rising was represented in the test videos. Before making these judgments, the therapists viewed a separate set of training videos and received instructions in the use of specific visual cues to assist with subsequent judgments.

RESULTS AND DISCUSSION

Therapists judged the involved side correctly 74% of the time. Mean accuracy in judging ground reaction force output was 39% across all therapists. Force symmetry did not significantly influence accuracy of force judgments. Inaccurate judgments of force may limit therapeutic intensity and minimize the potential for developing motor strategies that favor force production of the involved limb. Augmenting observational analysis of STS with quantitative data could assist in optimizing restorative function.

CONCLUSION

Judgments of lower limb ground reaction force output during STS based on observation alone are not valid and may need to be supplemented with quantitative data.

Generalizability and Validation of PROMIS Scores to Predict Surgical Success in Foot and Ankle Patients

Category:

Patient Reported Outcomes

Introduction/Purpose:

Patient-reported outcomes are advancing clinical care by improving patient satisfaction and engagement. A recent publication reported preoperative PROMIS scores to be highly predictive in selecting patients who would and would not benefit from foot and ankle (F/A) surgery. Although this publication used the data from 5 fellowship trained foot and ankle surgeons at one institution, the generalizability to other patient populations and geographic areas is unknown. This validation study assesses the pre-operative PROMIS physical function (PF) and pain interference (PI) t-scores as a predictor of post-operative success from a separate geographic area.

Methods:

Prospective consecutive patient visits to a multi-surgeon tertiary F/A clinic were obtained between 1/2014-11/2016 resulting in 18,565 unique visits and 1,408 new patients. Patients undergoing elective operative intervention for F/A were identified by ICD-9/10; CPT code. PROMIS PF and PI were assessed at initial and follow-up visits (minimum 6 months, mean 7.8 months). Two-way ANOVA was used to determine differences in PROMIS PF and PI from pre to post surgery with age and gender as co- variates. The distributive method of estimating a minimal clinical important difference (MCID) was used. Receiver operator curve (ROC) analysis was used to determine cut offs for achieving and failing to achieve MCID. To determine the validity of previously published cut offs, 1) they were compared to cut offs for this data set and 2) the percentage of patients achieving and failing to achieve MCID based on previous cut offs were evaluated using a chi-square analysis.

Results:

There were significant improvements in PROMIS PF scores (mean=6.0; sd=11.6; p<0.01) and PI scores (mean=-7.0; sd=8.4; p<0.01). The AUC for PROMIS PF (0.77) was significant (p < 0.01) and the cut offs for achieving MCID (current data = <23.8 versus previous study= <29.7) and failing to achieve MCID (current data=>41.1 versus previous study=>42) were comparable (Figure 1). Of the patients identified as unlikely to achieve MCID, a significant proportion (88.9%) failed to achieve an MCID ((Chi square=4.7; p=0.03). Of the patients identified as likely to achieve MCID, a significant proportion (84.2%) achieved MCID ((Chi square=17.8; p<0.01). This validates the prior preoperative PROMIS PF thresholds for patients undergoing F/A surgery who will and will not demonstrate MCID improvement in PROMIS PF. The AUC for PROMIS PI was not significant.

Conclusion:

PROMIS PF cut offs from published data were successful in classifying patients who would improve in PF with surgery from a different geographic area and academic institution with a broad unique array of surgical procedures, diagnoses, and a diverse patient population. This study provides validation evidence to support using the PROMIS PF as a potential tool for surgical selection to help identify patients who would benefit from surgery as well as those who would not. This can allow for appropriate utilization of healthcare dollars and manpower resources to benefit our patients.

Reading the Future

Category:

Bunion, Midfoot/Forefoot

Introduction/Purpose:

Hallux valgus is a common condition of the foot with 4.4 million patients seeking care yearly for this condition. A previous study suggested specific pre-operative cut-off scores based on Patient Reported Outcomes Measurement Information System (PROMIS) physical function (PF), pain interference (PI), and depression (D) values could predict post-operative outcomes in foot and ankle surgery. Though hallux valgus correction, among other procedures, were identified as one of the most common surgeries in the previous study, specific conditions were not considered separately. The purpose of this study was to evaluate the validity of applying a published comprehensive pre-surgical PROMIS profile of PF, PI and D to patients undergoing bunionectomy surgery.

Methods:

PROMIS scores were prospectively obtained from patients evaluated in a specialty foot and ankle clinic between February 2015 and November 2016. Using ICD-9/10 and CPT codes, a total of 65 patients with hallux valgus who underwent a bunionectomy by a single surgeon were identified. Those with less than two-month follow-up, multiple procedures during the follow-up period, and incomplete PROMIS assessment scores were excluded, resulting in 42 patients. Using pre-operative scores and scores at the last follow-up visit, minimally clinically important differences (MCID), receiver operating characteristic (ROC) curves, and area under the curve (AUC) were obtained to determine if pre-operative PROMIS scores predicted achieving MCID with 95% specificity or failing to achieve a MCID with 95% sensitivity. New cut-off values were then compared to the previous study.

Results:

The AUC for PF (p=0.01) and Mood (p=0.03) were significant. However, PI AUC was not significant (p=0.14). The PF cut off for 95% specificity of exceeding MCID was 39.6 and 50.2 for 95% sensitivity for failing to achieve MCID. The D cut off for 95% specificity of exceeding MCID was 39.4 and 58.1 for 95% sensitivity for failing to achieve MCID. Patients below the 50.2 threshold (n=27) had significantly greater improvements on PF (2.3 95% CI 0.5 to 4.3) and PI (-3.8 95% CI -6.9 to -0.7) but not D. Patients above the 50.2 cut off (n=15) were significantly worse on PF (-7.3 95% CI -12.0 to -2.7) at this short follow up and were statistically unchanged on PI and D.

Conclusion:

This data confirms that pre-surgical PROMIS PF and Depression scores are significant post-surgical predictors. However, cut-off scores for 95% sensitivity/specificity were one standard deviation higher for PROMIS PF (>50.2 versus previous study >42) and similar for Depression (<39.4 versus previous study <41.5) as compared to all foot and ankle surgeries. Patients meeting the new cut-off (>50.2) experienced significantly better outcomes on all PROMIS scales and patients not meeting the cut- off (~30%) were significantly worse. Although longer term follow-up is desirable, this short term follow up suggests a significant clinical impact of using PROMIS scores for pre-surgical decisions.

What Does a PROMIS T-score Mean for Physical Function?

Category:

Basic Sciences/Biologics, Outcomes Measurement

Introduction/Purpose:

The use of patient-reported outcomes (PRO) continues to expand beyond research to involve standard of care assessments. Although the PROMIS physical function (PF) is normalized to a T-score it is unclear how to interpret and apply this information in the daily care of patients. The T-score is abstract and unanchored to patient abilities impairing its clinical utility when shared with the patient. Patient questions are concrete such as “when will I be able to run again after this procedure?” The purpose of this research was to link PROMIS PF T-scores with physical function activities and provide a visual map of this linkage to aid in treatment assessment and address concrete patient education.

Methods:

The 124 items used by the PROMIS PF item response model (ver. 1.0) were obtained. Of the 124 items, 61 items were placed into tasks categories associated with activities of daily living (ADL’s) [hygiene, toileting, bathing, dressing, and transfers], standing, walking (i.e. ambulation), stairs, and running. Other items not included on this lower extremity assessment were specific to the upper extremity, included tasks (i.e. house work) not typically assessed on previous measures, and global questions covering multiple tasks. For each of the 61 items there were 4 item response parameters (Likert scale) used to place patients in 5 categories ranging from low (unable) to high ability (able without difficulty), resulting in 305 possible responses. A one page visual map of the association of the highest PROMIS T- score for each task was produced (Figure 1).

Results:

Patients who report independence in ALL ADL’s score a minimum T-score of 47. Independence (highest ability) for ADL’s results in the following T-scores: hygiene (30), toileting (35), dressing (39), bathing (39), transfers (47), standing (46), walking (52.5), stairs (52.5), and running (72.5). T-scores that ranged from lowest to highest based on the Likert responses were: hygiene (12-30), toileting (14-35), dressing (10-39), bathing (16-39), transfers (15-47), standing (19-46), walking (20-52.5), stairs (21-52.5), and running (35-72.5). Specifically, patients report the inability to transfer, walk, climb stairs, or run with scores of 15, 20, 21, and 35 respectively. Similarly, high scores (no difficulty) for transfers (47), walking (52.5), stairs (52.5), and running (72.5) may be used to set goals in response to treatment or return to work/sports.

Conclusion:

PROs provide real time assessments and a road map to follow patients throughout a treatment course. Understanding the translation of the outcome score (T-score) to patient physical activity allows the patient and physician to have realistic expectations of recovery. Applying this PF and activity linkage data to cohorts of patients with common surgeries will allow patients to gain a better understanding of the recovery duration and return to activity timing. Providing this patient friendly knowledge will help enhance patient engagement and patient satisfaction.

When are the Patients Satisfied with Their Outcome? Correlation of PROMIS Values with Patient Acceptable Symptom State (PASS) Scores in Foot and Ankle Patients

Category:

Outcomes

Introduction/Purpose:

PROMIS values are being adopted due to ease of use and influence on clinical decision making. Studies support the use of PROMIS physical function (PF), pain interference (PI), and Depression (D) for pre-surgical decision making. Patient Acceptable Symptom State (PASS) is a validated outcome measure commonly used in other areas of medicine and surgery that captures when patient’s symptoms reach a daily acceptable level. Knowing what PROMIS scores are associated with a patient’s PASS(Yes)/(No) rating would further enhance the use of PROMIS scales. The purpose of this study: 1) association of PROMIS scales with a PASS rating, 2) threshold values of PROMIS PF, PI, D associated with PASS rating, and 3) whether PROMIS, and patient demographics are predictive of a PASS rating.

Methods:

464 consecutive foot and ankle patients (variety of foot and ankle conditions) over a 4 week interval prospectively completed PROMIS PF, PI and D as well as the PASS question: “Taking into account all of the activities that you do during your daily life, your level of pain, and also your function, do you consider that the current state of your foot and ankle is satisfactory?” PROMIS assessments are used as the standard of care however, the point patients feel they have improved to an acceptable degree (PASS) is not known. The analysis included 1) a two-way ANOVA to compare PROMIS scores (PF, PI, D) between patients grouped as PASS(Yes) and PASS(No); 2) ROC analysis to determine AUC, cut offs, and 95% sensitivity/specificity for PASS(Yes), PASS Ambiguous, and PASS(No); 3) Logistic regression analysis with PROMIS scales, age, gender, and visit type as predictors and PASS(Yes)/(No).

Results:

PROMIS PF was lower (p<0.01) and PI higher (p<0.01), however, PROMIS D (p=0.26) was similar between PASS(Yes/No) groups. The AUC for PROMIS PF(p<0.01) and PI(p<0.01) were significant but not PROMIS D (p=0.21). The cut offs for PASS(Yes) with 95% specificity were 52.0 and 50.7 for PF and PI, respectively. The cut offs for PASS(No) with 95% sensitivity were 23.6 and 69.6 for PF and PI, respectively. PROMIS values between 23.6 and 52 for PF and between 50.7 and 69.6 for PI were PASS ambiguous. Regression analysis showed that gender, visit type, and PROMIS (PI/PF) significantly predicted PASS(Yes)/(No) (75% accuracy).

Conclusion:

PROMIS t-scores of near 50 (average of US population) correspond to PASS(Yes) cut offs for both PF and PI. When feasible a benchmark of 50 on PROMIS T-scores may be a reasonable goal for patient outcome after foot and ankle treatments. For patients that are PASS ambiguous, other factors such as preoperative PROMIS scores (PF and PI), gender, and visit type (new or follow up) may motivate discussions with patients about their expectations of treatment. Longer term follow-up, may result in a higher percentage of PASS YES patients and alter cut off scores.

Trends in PROMIS Scores in the Early Post-operative Period following Various Lateral Ankle Ligament Reconstructive Techniques

Category:

Sports

Introduction/Purpose:

Lateral ankle ligament injuries are common conditions accounting for 25% of musculoskeletal injuries. When conservative management fails and chronic instability ensues, operative treatment is often sought. Though surgical outcomes are generally good following lateral ankle ligament reconstruction, literature suggests current scoring systems for evaluating outcomes and monitoring progression have deficiencies. Patient Reported Outcomes Measurement Information (PROMIS) scores have recently been established as a method of monitoring patient outcomes. The purpose of this study was to evaluate the trends in post-operative PROMIS physical function (PF), pain interference (PI), and depression scores in patients undergoing lateral ankle ligament reconstruction.

Methods:

PROMIS scores were prospectively obtained from all patients evaluated in our foot and ankle clinic between February 2015 and October 2016. Using ICD-9/10 and CPT codes, a total of 111 patients who underwent lateral ankle ligament reconstruction were identified. After meeting exclusion criteria (less than three-month follow-up, incomplete PROMIS scores or multiple surgeries), 55 patients were included. PROMIS PF, PI, and depression were evaluated at each post-operative visit. Changes in scores were calculated as compared to baseline pre-operative scores and compared at each follow-up time point using two-way ANOVA. Differences in reconstruction type in patients undergoing allograft (A), modified Broström-Gould (BG), or modified Broström-Gould augmented with fibertape (BG+FT) were also evaluated.

Results:

The average follow-up was 27.05 weeks (range 12-60.1 weeks). 11 patients had > 9 months follow-up. Changes in PF were significantly different from baseline at all time-points except for 8-12 week follow-up. PF was significantly worse at 2 and 4-6 week follow-up, and significantly better at >12 weeks follow-up (p<0.01). PI significantly improved from baseline beginning at 8-12 week follow-up (p=0.02). Depression was unchanged from baseline at 2 weeks and 4-6 week follow-up, then significantly improved thereafter (p<0.01). Though not significant, when comparing reconstruction types, there was a trend towards slower improvement in PF in those with BG+FT (n=15), compared to A (n=17, p=0.07) and BG (n=21, p=0.051) at 8-12 weeks. Two patients had other types of reconstruction and were not included in this analysis.

Conclusion:

Patients undergoing lateral ankle ligament reconstruction demonstrate significant improvements in PF, PI, and depression PROMIS scores compared to baseline. Patients reached baseline PF at 8-12 weeks follow-up, and significantly improved beyond >12 weeks. PI scores were significantly improved from baseline beginning at 4 weeks follow-up. Depression scores also significantly improved at 8-12 weeks follow-up. BG+FT showed a trend of slower improvement in PF, though not significant. Though longer follow-up is needed, the significant improvements in PF, PI, and depression following lateral ankle ligament reconstruction in our study provides data that can be used for pre-operative counseling and monitoring progression post-operatively.

The Road to Recovery for Bunion Surgery

Category:

Bunion, Midfoot/Forefoot

Introduction/Purpose:

Patient reported outcomes (PROs) can provide information on individual patient’s progress throughout a treatment course and additionally, with common surgeries, powerful numbers can be generated to provide data analytic curves to provide a recovery road map for patients and surgeons. Those who deviate negatively from the predicted path may have a complication and early intervention can be initiated. Those who deviate positively have the potential to need less physical therapy, early return to sports or work. Hallux valgus (HV) is a common condition of the foot with 4.4 million patients seeking care yearly and surgery is equally common. The purpose of this study was to determine if PROMIS PROs can be used to construct data analytic curves for HV surgery.

Methods:

PROMIS scores were prospectively obtained from patients evaluated in a specialty foot and ankle clinic between February 2015 and November 2016. Using ICD-9/10 and CPT codes, a total of 65 patients with hallux valgus who underwent a bunionectomy by a single surgeon were identified. Those with less than two-month follow-up, multiple procedures during the follow-up period, as well as incomplete PROMIS assessment scores at any time point were excluded, resulting in 34 patients. Using a previously described method, bunionectomy-specific pre-operative cut-off values to achieve and fail to achieve minimally clinically important differences (MCID) in PF with 95% specificity and 95% sensitivity were determined. We then stratified patients based on their pre-operative PF T-scores as above or below the MCID cut-off. PF was evaluated using two-way ANOVA at 4 follow-up time periods and pre-operative cut-offs (above or below MCID cut-off) as factors to establish data analytic curves based on pre- operative scores.

Results:

Bunionectomy-specific PF cut-off for 95% specificity of exceeding MCID was 39.6 and 50.2 for 95% sensitivity for failing to achieve MCID. Patients were stratified based on PF T-scores above (n = 13) or below (n = 21) the MCID cut-off of 50.2. Data analytic curves were generated for above the PF cut off and below PF cut off. (Figure 1) Pairwise comparison demonstrated that those starting with a T-score above the bunionectomy specific cut-off had significantly better PF pre-operatively (p < 0.01) and again at 6-12 week follow-up (p = 0.02). There were no differences at 1 week or 3-4 week follow-up time points.

Conclusion:

This data confirms pre-operative PROMIS PF scores are significant post-operative predictors. While patients with pre-operative scores below the bunionectomy-specific cut-off met MCID changes in PF, their T-scores were significantly lower at 6-12wk follow-up than patients with high pre-operative T-scores. Although longer term follow-up is desirable, this short term follow up suggests a significant clinical impact of using PROMIS scores for pre-surgical decisions as well as provides a road map for recovery for patients and surgeons.

Clinical Utilization of Patient Reported Outcome (PROMIS) Scores for Surgical Reconstruction of Posterior Tibialis Tendon Dysfunction

Category:

Hindfoot

Introduction/Purpose:

Previous studies have demonstrated that preoperative Patient Reported Outcome Instrumentation System (PROMIS) scores effectively predict improvement in foot and ankle surgery. Adult acquired flatfoot deformity (AAFD) and Posterior Tibialis Tendon Dysfunction (PTTD) are a common surgical problem, but it is unclear if the specific thresholds for the physical function (PF), pain interference (PI) and depression published previously for all foot and ankle surgeries apply to a specific diagnosis. Furthermore, the interplay of PROMIS scores and clinical variables has not been evaluated. The purpose of this study was: 1) to investigate the change in PROMIS scales and radiographic measurements from pre- to postoperative follow up in AAFD/PTTD patients, 2) to determine if preoperative PROMIS scales predict post-surgical improvement, 3) to determine if demographic, clinical variables combined with pre-operative PROMIS scales predict post-surgical improvement.

Methods:

Using ICD-9/10 and CPT codes, 60 patients who underwent surgical reconstruction for AAFD/PTTD at a tertiary care center between February 2015 and November 2016 were identified. PROMIS PF, PI and Depression were assessed at initial and follow-up. A total of 35 adult patients with PROMIS scores and radiographs at baseline and greater than 3 months follow-up (mean=10.8 months) were included. For hypothesis #1, two way repeated measures ANOVAs determined pre- to post-operative change in PROMIS scales and radiographic measurements. For hypothesis #2, receiver operator curve (ROC) analysis determined the accuracy and thresholds for pre-operative decision making. For hypothesis #3, the multiple linear regression of demographic (age, gender, BMI), clinical (stage) and radiographic variables with pre-operative PROMIS scales for predicting post-operative change in PROMIS scales were evaluated (Models included: pre-operative PROMIS PF + BMI + stage AND pre-operative PROMIS PF + BMI + delta Meary’s).

Results:

PROMIS scales (PF(4.1), PI(-6.2) and Depression(-6.1)) and radiographic angles (lateral Meary’s (-10.8) and A/P Talo/1st metatarsal angle (-10.9) were significantly improved (p<0.01). Pre-operative PROMIS PF (AUC = 0.80±0.8, p <0.01) and PI (AUC=0.81±0.07, p<0.01) showed significant AUC for predicting Minimal Clinically Important Difference (MCID improvement in PROMIS PI. Pre-operative PROMIS Depression showed a significant AUC (0.85±0.07) for predicting MCID improvement in PROMIS Depression. However, pre-operative PROMIS PF was not predictive of MCID improvement in PROMIS PF (AUC=0.64±0.09, p=0.17). Only pre- to post-operative change in lateral Meary’s angle predicted post-operative MCID improvement for PROMIS PF (AUC of 0.85±0.08, p<0.01). The threshold for a 95% specificity/sensitivity for achieving MCID improvement in PROMIS PF was >12.5 degrees/2.5 degrees, respectively. Models combining clinical, radiographic, and PROMIS variables achieved significance (AUC > 0.81).

Conclusion:

PROMIS scales and radiographic angles improve significantly following surgical reconstruction of PTTD. Unlike previous studies, PROMIS PF was not predictive of improvement in PROMIS PF. However, PROMIS PF and PI were predictive of improvement in PROMIS PI. Radiographic improvement on lateral Meary’s angle was the most strongly predictive of improvement in PROMIS PF. The strongest predictor of postoperative improvement in PROMIS PF was a combination of preoperative PROMIS PF, BMI, and stage an interplay of variables not previously evaluated. Pre-operative PROMIS thresholds are effective across diagnosis, however, diagnosis specific criteria may further enhance pre-operative decisions.

Can Foot Exercises Alter Foot Posture, Strength, and Walking Foot Pressure Patterns in People with Severe Flat Foot?

Category:

Midfoot/Forefoot, Sports

Introduction/Purpose:

Muscle training muscle control for barefoot running (i.e. doming seated[DS] and standing[DSt]) and post foot and ankle injury (i.e. seated plantar flexion and inversion[SPFI]) are common. Although studies demonstrated improvement in foot posture (validated foot posture index [FPI]) immediately following a 4-week exercise program this was not assessed in people with flatfoot. Also, more rigorous assessment of foot function is lacking (i.e. foot posture, strength, and plantar pressure during walking). There is clearly a need for more rigorous clinical data on the effect of foot exercises. The purpose of this pilot study was to assess the immediate effect of a 4-week exercise program on a comprehensive assessment of foot function to evaluate the potential for a more rigorous clinical trial.

Methods:

Eighteen individuals, 8 with a severe flatfoot (SFF), measured by FPI (> 6/12, average=8.4±0.7), age=27.8±6.9, 7 females and 1 male) and 9 age/gender matched controls (AMC) with a normal foot (FPI=0-5, average=2.2±2.0) participated. The SFF group completed 3 foot exercises (DS, DSt, SPFI) 5 days/week twice daily. The SFF group were assessed before and after 4 weeks of exercise (called weekly for exercise progression). The control participants were tested once. Testing sessions included plantar pressure during a controlled walking cadence (110 bpm) (average of 5 steps over 40 feet). Masks were applied (medial/lateral toes and forefoot, heal, midfoot) and specific variables calculated (peak pressure, percent mean pressure) during stance phase. Clinical tests included heel rise repetitions, navicular drop, and paper pull test (peak force). T-tests were used to assess the effects of pre to post in the SFF group and between the SFF group and AMC pre and post exercise.

Results:

Two clinical tests significantly improved from pre to post in the SFF group (heel rises increased on right = 6.1± 3.7, p<0,01, left = 7.9± 6.1, p<0.01, and navicular drop indicated less arch lowering on the right (p=0.4) and left (p=0.06)), however, the paper pull test was not significant. Lateral forefoot mask for percent total mean pressure was lower in the SSF group pre exercise versus AMC (right p=0.02, left p=0.07). However, pre to post exercise the lateral forefoot mask for peak plantar pressure increased (left p=0.014, right p=0.02) and percent of total mean pressure also increased (right p=0.04, left p = 0.07) in the SFF group. Post exercise the SFF group lateral percent total mean pressure was no longer significant compared to controls.

Conclusion:

This data suggests that 4 weeks of foot only exercises (no ankle exercises) improved walking (Figure 1) and increased ankle strength (heel raise ability). Previous studies have not included rigorous assessment of foot function after foot exercises. This pilot data extends previous studies by suggesting foot muscle control may directly influence foot function during walking (i.e. plantar pressure). A power analysis using this data supports the conclusions with a larger sample of approximately 20-30 people. This pilot data supports the pursuit of a more rigorous trial of the positive effect of foot exercises in patients with severe flatfoot.

Tropospheric Emissions: Monitoring of Pollution (TEMPO)

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (H2CO), glyoxal (C2H2O2), bromine monoxide (BrO), IO (iodine monoxide),water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.

Individual metatarsal and forefoot kinematics during walking in people with diabetes mellitus and peripheral neuropathy

The purpose of this study was to compare in-vivo kinematic angular excursions of individual metatarsal segments and a unified forefoot segment in people with Diabetes Mellitus and peripheral neuropathy (DMPN) without deformity or ulceration to a healthy matched control group. Thirty subjects were recruited. A five- segment foot model (1st, 3rd, and 5th metatarsals, calcaneus, tibia) was used to examine relative 3D angular excursions during the terminal stance phase of walking. Student t-tests were used to assess group differences in kinematics. Pearson correlations and cross-correlations were used to assess relationships between the motion of the individual metatarsals and the unified forefoot. Significant reductions of DMPN group sagittal plane angular excursions were detected in all individual metatarsals and the unified forefoot (p < 0.01). Frontal plane 3rd metatarsal excursion was reduced (p = 0.04) in the DMPN group. The 3rd and 5th metatarsal and the unified forefoot excursions were reduced (p ≤ 0.02) in the DMPN group in the transverse plane. In both groups, coupling of individual metatarsal and unified forefoot motion was strongest in the sagittal plane. This study illustrates that multiple individual metatarsals have reduced motion in people with DMPN. Differences in the magnitude and coupling between individual metatarsal motion and unified forefoot motion supports the use of a two segment forefoot modeling approach in future kinematic analyses. Further study is recommended to determine if the observed kinematic profile is related to the development and location of deformity and tissue breakdown in people with DMPN.

Randomized Controlled Trial Comparing Orthosis Augmented by Either Stretching or Stretching and Strengthening for Stage II Tibialis Posterior Tendon Dysfunction

BACKGROUND

The value of strengthening and stretching exercises combined with orthosis treatment in a home-based program has not been evaluated. The purpose of this study was to compare the effects of augmenting orthosis treatment with either stretching or a combination of stretching and strengthening in participants with stage II tibialis posterior tendon dysfunction (TPTD).

METHODS

Participants included 39 patients with stage II TPTD who were recruited from a medical center and then randomly assigned to a strengthening or stretching treatment group. Excluding 3 dropouts, there were 19 participants in the strengthening group and 17 in the stretching group. The stretching treatment consisted of a prefabricated orthosis used in conjunction with stretching exercises. The strengthening treatment consisted of a prefabricated orthosis used in conjunction with the stretching and strengthening exercises. The main outcome measures were self-report (ie, Foot Function Index and Short Musculoskeletal Function Assessment) and isometric deep posterior compartment strength. Two-way analysis of variance was used to test for differences between groups at 6 and 12 weeks after starting the exercise programs.

RESULTS

Both groups significantly improved in pain and function over the 12-week trial period. The self-report measures showed minimal differences between the treatment groups. There were no differences in isometric deep posterior compartment strength.

CONCLUSIONS

A moderate-intensity, home-based exercise program was minimally effective in augmenting orthosis wear alone in participants with stage II TPTD.

LEVEL OF EVIDENCE

Level I, prospective randomized study.

Ankle arthroplasty and ankle arthrodesis: gait analysis compared with normal controls

BACKGROUND

This study compared patients with isolated end-stage ankle osteoarthritis, after undergoing either total ankle arthroplasty or arthrodesis, using gait analysis and patient-reported outcome measures to elucidate differences between the two treatment options, as compared with a healthy control group.

METHODS

Gait analyses were performed on patients with isolated ankle arthritis more than one year after undergoing either total ankle arthroplasty or arthrodesis during a ten-year period. Validated outcome questionnaire data were obtained. Seventeen patients undergoing total ankle arthroplasty, seventeen patients undergoing arthrodesis, and ten matched control subjects were included for comparison.

RESULTS

Patients who had undergone arthroplasty, when compared with patients who had undergone arthrodesis, demonstrated greater postoperative total sagittal plane motion (18.1° versus 13.7°; p < 0.05), dorsiflexion (11.9° versus 6.8°; p < 0.05), and range of tibial tilt (23.1° versus 19.1°; p < 0.05). Plantar flexion motion was not equivalent to normal in either group. Ankle moments and power in both treatment groups remained significantly lower compared with the control group (p < 0.05 between each treatment group and the control group for both variables). Gait patterns in both treatment groups were not completely normalized. Improvements in patient-reported Ankle Osteoarthritis Scale and Short Form-36 scores were similar for both treatment groups.

CONCLUSIONS

The gait patterns of patients following three-component, mobile-bearing total ankle arthroplasty more closely resembled normal gait when compared with the gait patterns of patients following arthrodesis. Dorsal motion in the sagittal plane was primarily responsible for the differences. Improvement in self-reported clinical outcome scores was similar for both groups. Further investigation is needed to determine why patients who have undergone total ankle arthroplasty do not use the plantar flexion motion in the terminal-stance phase and to explain the limited increase in power generation at toe-off after arthroplasty. Results obtained from this study may be used for future modifications of ankle prostheses and may add to clinicians' ability to inform patients of predicted functional outcomes prior to the treatment of end-stage ankle osteoarthritis.

Dissecting x-ray-emitting gas around the center of our galaxy

Most supermassive black holes (SMBHs) are accreting at very low levels and are difficult to distinguish from the galaxy centers where they reside. Our own Galaxy's SMBH provides an instructive exception, and we present a close-up view of its quiescent x-ray emission based on 3 megaseconds of Chandra observations. Although the x-ray emission is elongated and aligns well with a surrounding disk of massive stars, we can rule out a concentration of low-mass coronally active stars as the origin of the emission on the basis of the lack of predicted iron (Fe) Kα emission. The extremely weak hydrogen (H)-like Fe Kα line further suggests the presence of an outflow from the accretion flow onto the SMBH. These results provide important constraints for models of the prevalent radiatively inefficient accretion state.

Clinical outcomes and static and dynamic assessment of foot posture after lateral column lengthening procedure

BACKGROUND

Lateral column lengthening (LCL) has been shown to radiographically restore the medial longitudinal arch. However, the impact of LCL on foot function during gait has not been reported using validated clinical outcomes and gait analysis.

METHODS

Thirteen patients with a stage II flatfoot who had undergone unilateral LCL surgery and 13 matched control subjects completed self-reported pain and functional scales as well as a clinical examination. A custom force transducer was used to establish the maximum passive range of motion of first metatarsal dorsiflexion at 40 N of force. Foot kinematic data were collected during gait using 3-dimensional motion analysis techniques.

RESULTS

Radiographic correction of the flatfoot was achieved in all cases. Despite this, most patients continued to report pain and dysfunction postoperatively. Participants post LCL demonstrated similar passive and active movement of the medial column when we compared the operated and the nonoperated sides. However, participants post LCL demonstrated significantly greater first metatarsal passive range of motion and first metatarsal dorsiflexion during gait than did controls (P < .01 for all pairwise comparisons).

CONCLUSION

Patients undergoing LCL for correction of stage II adult-acquired flatfoot deformity experience mixed outcomes and similar foot kinematics as the uninvolved limb despite radiographic correction of deformity. These patients maintain a low arch posture similar to their uninvolved limb. The consequence is that first metatarsal movement operates at the end range of dorsiflexion and patients do not obtain full hindfoot inversion at push-off. Longitudinal data are necessary to make a more valid comparison of the effects of surgical correction measured using radiographs and dynamic foot posture during gait.

LEVEL OF EVIDENCE

Level III, comparative series.

Total and distributed plantar loading in subjects with stage II tibialis posterior tendon dysfunction during terminal stance

BACKGROUND

In subjects with stage II tibialis posterior tendon dysfunction (TPTD), the function of the tibialis posterior muscle is altered and may be associated with a change in total and distributed loading.

METHODS

Thirty subjects with a diagnosis of stage II TPTD and 15 matched control subjects volunteered to participate in a study to examine the total and distributed plantar loading under the foot during the terminal stance phase of gait. Plantar loading, measured as the subject walked barefoot, was assessed using instrumented flexible insoles. A secondary analysis was done to explore the contribution of flatfoot kinematics to plantar loading patterns.

RESULTS

Overall, there was reduced total plantar loading in subjects with stage II TPTD compared with controls. Accounting for differences in total loading, the presence of clinically measured weakness in subjects with TPTD was associated with reduced lateral forefoot loading. Medial longitudinal arch height was significantly correlated with loading patterns but explained only 21% of the variance in observed loading patterns.

CONCLUSION

Subjects with TPTD who are strong exhibited loading patterns similar to controls. Changes in total and distributed loading during terminal stance suggest there are altered ankle mechanics at push-off during the functional task of gait.

CLINICAL RELEVANCE

Strength, in the presence of TPTD, may be important to stabilize the midfoot during gait and might be important in rehabilitation protocols.

Analysis of vertical ground reaction force variables during a Sit to Stand task in participants recovering from a hip fracture

BACKGROUND

A Sit to Stand task following a hip fracture may be achieved through compensations (e.g. bilateral arms and uninvolved lower extremity), not restoration of movement strategies of the involved lower extremity. The primary purpose was to compare upper and lower extremity movement strategies using the vertical ground reaction force during a Sit to Stand task in participants recovering from a hip fracture to control participants. The secondary purpose was to evaluate the correlation between vertical ground reaction force variables and validated functional measures.

METHODS

Twenty eight community dwelling older adults, 14 who had a hip fracture and 14 control participants completed the Sit to Stand task on an instrumented chair designed to measure vertical ground reaction force, performance based tests (Timed up and go, Berg Balance Scale and Gait Speed) and a self report Lower Extremity Measure. A MANOVA was used to compare functional scales and vertical ground reaction force variables between groups. Bivariate correlations were assessed using Pearson Product Moment correlations.

FINDINGS

The vertical ground reaction force variables showed significantly higher bilateral arm force, higher uninvolved side peak force and asymmetry between the involved and uninvolved sides for the participants recovering from a hip fracture (Wilks' Lambda=3.16, P=0.019). Significant correlations existed between the vertical ground reaction force variables and validated functional measures.

INTERPRETATION

Participants recovering from a hip fracture compensated using their arms and the uninvolved side to perform a Sit to Stand. Lower extremity movement strategies captured during a Sit to Stand task were correlated to scales used to assess function, balance and falls risk.

The relationship between ankle, hindfoot, and forefoot position and posterior tibial muscle excursion

BACKGROUND

The purpose of this study was to examine the relationship of forefoot position in the transverse plane (abduction/adduction), hindfoot position in the frontal plane (eversion/inversion), and ankle position in the sagittal plane (plantarflexion/dorsiflexion) with posterior tibialis (PT) muscle excursion using an in vitro cadaver model.

METHODS

Seven fresh-frozen cadaver specimens were potted and mounted on a frame. The PT tendon was dissected 15 cm proximal to the medial malleolus, and a 5-kg weight was sutured to the tendon. A six-camera motion analysis system (Optotrak, Northern Digital, Inc.) was used to track three-dimensional (3-D) motion of the tibia, calcaneus (hindfoot) and first metatarsal (forefoot) using bone pins. The ankle, hindfoot, and forefoot were manually placed in 24 different ankle and foot positions. A stepwise regression analysis was used to examine the relationship among ankle, hindfoot, and forefoot kinematics and PT muscle excursion.

RESULTS

Hindfoot eversion/inversion and forefoot abduction/adduction accounted for 77% of the variance in PT muscle excursion, with small contributions from ankle plantarflexion/dorsiflexion (5.7%) and forefoot plantarflexion/dorsiflexion (1.9%). A combined regression equation applied to individual specimens resulted in average errors of less than 2.5 mm.

CONCLUSIONS

This study supports the hypothesis that PT muscle excursion can be estimated using specific foot and ankle kinematic variables. Further, these data suggest that hindfoot eversion and forefoot abduction account for most of the variance in PT muscle excursion and are theorized to be important to control clinically altering the length of the posterior tibial muscle.

Accelerated fracture healing

Acceleration of the fracture healing process would have far-reaching benefits for both civilians and military personnel. Decreasing the time to return to complete function would reduce medical costs, enhance quality of life by decreasing pain and increasing mobility, accelerate the return of professional athletes to their sport, and decrease the time for military recruits to enter active duty after injuries incurred in basic training. Moreover, augmenting the healing process may prevent the long-term disability caused by fracture nonunion. Currently available pharmaceutical agents may allow us to realize this goal. However, these agents need to be tested in prospective randomized clinical trials.

Comparison of foot kinematics between subjects with posterior tibialis tendon dysfunction and healthy controls

STUDY DESIGN

A 2 x 4 mixed-design ANOVA with a fixed factor of group (posterior tibialis tendon dysfunction [PTTD] and asymptomatic controls), and a repeated factor of phase of stance (loading response, midstance, terminal stance, and preswing).

OBJECTIVE

To compare 3-dimensional stance period kinematics (rearfoot eversion/inversion, medial longitudinal arch [MLA] angle, and forefoot abduction) of subjects with stage II PTTD to asymptomatic controls.

BACKGROUND

Abnormal foot postures in subjects with stage II PTTD are clinical indicators of disease progression, yet dynamic investigations of forefoot, midfoot, and rearfoot kinematic deviations in this population are lacking.

METHODS

Fourteen subjects with stage II PTTD were compared to 10 control subjects with normal arch index values. Subjects were matched for age, gender, and body mass index. A 5-segment, kinematic model of the leg and foot was tracked using an Optotrak Motion Analysis System. The dependent kinematic variables were rearfoot inversion/eversion, forefoot abduction/adduction, and the MLA angle. An ANOVA model was used to compare kinematic variables between groups across 4 phases of stance.

RESULTS

Subjects with PTTD demonstrated significantly greater rearfoot eversion (P = .042), MLA angle (P = .008) and forefoot abduction angles (P < .005) during specific phases of stance. Subjects with PTTD demonstrated significantly greater rearfoot eversion (P<.004) and MLA angles (P < .009) by 6.2 degrees and 8.0 degrees, respectively, during loading response when compared to controls. During preswing, the subjects with PTTD demonstrated a significantly greater MLA angle (P < .002) and a forefoot abduction angle (P<.001) which exceeded that of the controls by 10.0 degrees.

CONCLUSIONS

The abnormal kinematics observed at the rearfoot, midfoot, and forefoot across all phases of stance implicate a failure of compensatory muscle and secondary ligamentous support to control foot kinematics in subjects with stage II PTTD.

Effects of childhood obesity on three-dimensional knee joint biomechanics during walking

Despite the increasing percentages of children who are overweight, few studies have investigated their gait patterns. The purpose of this study was to quantify the three-dimensional knee joint kinematics and kinetics during walking in children of varying body mass and to identify effects associated with obesity. Three-dimensional kinematics and kinetics were collected from children of normal weight and overweight during normal gait using surface-mounted infrared emitting diodes and a force plate. The overweight group walked with a significantly lower peak knee flexion angle during early stance, and no significant differences in peak internal knee extension moments were found between groups. However, the overweight group showed a significantly higher peak internal knee abduction moment during early stance. These data suggest that although overweight children may develop a gait adaptation to maintain a similar knee extensor load, they may not be able to compensate for alterations in the frontal plane, which may lead to increased medial compartment joint loads. Therefore, assuming that the development of varus angular deformities of the knee joint and, in the longer term, medial compartment osteoarthritis are influenced by cumulative stress, this study supports the understanding that childhood obesity may impart a greater risk for the development of these diseases.

Rabbit knee joint biomechanics: motion analysis and modeling of forces during hopping

Although the rabbit hindlimb has been commonly used as an experimental animal model for studies of osteoarthritis, bone growth and fracture healing, the in vivo biomechanics of the rabbit knee joint have not been quantified. The purpose of this study was to investigate the kinematic and kinetic patterns during hopping of the adult rabbit, and to develop a model to estimate the joint contact force distribution between the tibial plateaus. Force platform data and three-dimensional motion analysis using infrared markers mounted on intracortical bone pins were combined to calculate the knee and ankle joint intersegmental forces and moments. A statically determinate model was developed to predict muscle, ligament and tibiofemoral joint contact forces during the stance phase of hopping. Variations in hindlimb kinematics permitted the identification of two landing patterns, that could be distinguished by variations in the magnitude of the external knee abduction moment. During hopping, the prevalence of an external abduction moment led to the prediction of higher joint contact forces passing through the lateral compartment as compared to the medial compartment of the knee joint. These results represent critical data on the in vivo biomechanics of the rabbit knee joint, which allow for comparisons to both other experimental animal models and the human knee, and may provide further insight into the relationships between mechanical loading, osteoarthritis, bone growth, and fracture healing.

Validity and comparisons of tibiofemoral orientations and displacement using a femoral tracking device during early to mid stance of walking

First, this study compares tibiofemoral motion during walking using a new femoral tracking device (FTD) and bone mounted markers in a single subject (n=1). The results suggest errors of <3 degrees in tibiofemoral angles using the FTD method over the first 85% of stance. Second, this study compares tibiofemoral angles and displacement during walking using the FTD method and a modified Helen Hayes method to track the femur in 13 subjects (n=13). The results suggest similar tibiofemoral angles in the sagittal and frontal planes using the two methods (average root mean square (RMS) differences <3.6+/-1.5 degrees ), and a large decrease in the transverse plane angles (average RMS differences=6.5+/-1.9 degrees ) and estimates of tibiofemoral displacement (P<0.05) using the FTD method. The FTD method presents a practical alternative to recording tibiofemoral transverse plane angles and displacement over the first 85% of stance.

Muscle activation patterns of selected lower extremity muscles during stepping and cutting tasks

Lower extremity muscle activations during crossover and side step cut tasks are hypothesized to play an important role in controlling knee motion, and therefore, impact the design of knee injury prevention and rehabilitation programs. However, the contribution of lower extremity muscles to frontal and transverse plane moments during cutting tasks is unclear. The purpose of this study was to compare the muscle activation patterns of selected lower extremity muscles (vastus lateralis, medial/lateral hamstrings and medial/lateral gastrocnemius) of subjects performing a stepping down and side step cut, a stepping down and crossover cut and an equivalent straight ahead task. Ground reaction force was used to determine the cut angle, stance time and compare the lower limb loading during each task. Electromyography data during all tasks were normalized to the average activation during the straight ahead tasks to determine relative changes in muscle activation between the straight ahead and different cut styles (crossover and side step). There were no differences in the pattern of muscle activation of the vastus lateralis, or lateral hamstring muscles when comparing the cutting tasks to the equivalent straight ahead task. However, the crossover cut task resulted in significantly higher muscle activation of the medial hamstrings and lateral gastrocnemius muscles relative to both the side step cut and straight ahead tasks. These results suggest the medial/lateral hamstrings and medial/lateral gastrocnemius play a role in transverse and frontal plane control during cut tasks.

Associations of knee angles, moments and function among subjects that are healthy and anterior cruciate ligament deficient (ACLD) during straight ahead and crossover cutting activities

The objective of this study was to compare knee angles and moments of healthy subjects (n=20) and subjects that were anterior cruciate ligament deficient (ACLD) (n=16) during stepping and crossover cutting activities. Subjects that were ACLD were separated into high (n=7) and low (n=9) functioning groups based on knee functional ratings. Knee angles and moments were estimated using three dimensional motion tracking and force plate data. The results suggest that knee angle and moment data were associated with level of functioning of ACLD subjects. Primarily knee frontal and transverse plane moments distinguished the stepping and crossover cut activities. Only some of the findings for the ACLD group were attributed to increasing knee stability.

Self-reported giving-way episode during a stepping-down task: case report of a subject with an ACL-deficient knee

STUDY DESIGN

Case report.

OBJECTIVE

To describe the knee kinematics and moments of a giving-way trial of a subject with an anterior-cruciate-ligament- (ACL) deficient knee relative to his non-giving-way trials and to healthy subjects during a step-down task.

BACKGROUND

Episodes of giving way are believed to damage joint structures, therefore treatments aim to prevent giving-way episodes, yet few studies document giving-way events.

METHODS

The giving-way trial experienced by a 32-year-old male subject with ACL deficiency during a step-down task was compared to his non-giving-way trials (n = 5) and data from healthy subjects (n = 20). Position data collected at 60 Hz were combined with anthropometric data and ground reaction force data collected at 300 Hz to estimate knee displacement and 3-dimensional angles and net joint moments.

RESULTS

The knee joint displacement was higher during the giving-way trial: from 4% to 32% of stance, reaching 9.0 mm at 18% of stance as compared to 1.6 +/- 0.7 mm for the non-giving-way trials. After 4% of stance, the knee flexion angle of the giving-way trial was 6.6 degrees higher than the non-giving-way trials and was associated with a higher knee extension moment. The knee frontal plane moment was near neutral during early stance of the giving-way trial in contrast to the non-giving way and healthy subjects which demonstrated a knee abduction moment.

CONCLUSIONS

The response of this subject to the giving-way event suggests that higher knee flexion angles may enhance knee stability and, in reaction to the giving-way event, that knee extension moment may increase.

Variations in the relationship between the frequency content of EMG signals and the rate of torque development in voluntary and elicited contractions

Our purpose was to characterize the relationship between EMG mean power frequency (MPF) or median frequency (MF) and rate of torque development in voluntary ballistic and electrically elicited isometric contractions. Twenty-three healthy adults participated in two sets of experiments performed on elbow flexor muscles. For Experiment 1, subjects were asked to generate voluntary ballistic contractions by reaching four different target torque levels (20, 40, 60 and 100% of the maximal voluntary contraction (MVC)) as fast as they could. For Experiment 2, electrical (M-waves) and mechanical (twitches) responses to electrical stimulation of the nerves supplying the biceps brachii and brachioradialis muscles were recorded with the subjects at rest and with a background isometric contraction of 15% MVC. MPF, MF and rate of torque development (% MVC/s) were calculated for both voluntary and elicited contractions. Significant positive correlations were observed between MPF and rate of torque development for the voluntary contractions, whereas significant negative correlations were observed between the two variables for elicited contractions. This suggests that factors other than muscle fiber composition influence the frequency content of EMG signals and/or the rate of torque development, and that the effect of these factors will vary between voluntary and elicited contractions.

Giving way event during a combined stepping and crossover cutting task in an individual with anterior cruciate ligament deficiency

STUDY DESIGN

Case study.

OBJECTIVE

To compare knee kinematics and moments of nongiving way trials to a giving way trial during a combined stepping and crossover cutting activity.

BACKGROUND

The knee kinematics and moments associated with giving way episodes suggest motor control strategies that lead to instability and recovery of stability during movement.

METHODS AND MEASURES

A 27-year-old woman with anterior cruciate ligament deficiency reported giving way while performing a combined stepping and crossover cutting activity. A motion analysis system recorded motion of the pelvis, femur, tibia, and foot using 3 infrared emitting diodes placed on each segment at 60 Hz. Force plate recordings at 300 Hz were combined with limb inertial properties and position data to estimate net knee joint moments. The stance time, foot progression angle, and cutting angle were also included to evaluate performance between trials.

RESULTS

Knee internal rotation during the giving way trial increased 3.2 degrees at 54% of stance relative to the nongiving way trials. Knee flexion during the giving way trial increased to 33.1 degrees at 66% of stance, and the knee moment switched from a nominal flexor moment to a knee extensor moment at 64% of stance. The knee abductor moment and external rotation moment during the giving way trial deviated in early stance.

CONCLUSIONS

The observed response to the giving way event suggests that increasing knee flexion may enhance knee stability for this subject. The transverse and frontal plane moments appear important in contributing to the giving way event. Further research that assists clinicians in understanding how interventions can impact control of movements in these planes is necessary.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.