Prediction of post-interventional physical function in diabetic foot ulcer patients using patient reported outcome measurement information system (PROMIS)

BACKGROUND

Infected diabetic foot ulcer (DFU) patients present with an impaired baseline physical function (PF) that can be further compromised by surgical intervention to treat the infection. The impact of surgical interventions on Patient Reported Outcomes Measurement Information System (PROMIS) PF within the DFU population has not been investigated. We hypothesize that preoperative PROMIS scores (PF, Pain Interference (PI), Depression) in combination with relevant clinical factors can be utilized to predict postoperative PF in DFU patients.

METHODS

DFU patients from a single academic physician's practice between February 2015 and November 2018 were identified (n = 240). Ninety-two patients met inclusion criteria with complete follow-up and PROMIS computer adaptive testing records. Demographic and clinical factors, procedure performed, and wound healing status were collected. Spearman's rank correlation coefficient, Chi-Squared tests and multidimensional modelling were applied to all variables' pre- and postoperative values to assess patients' postoperative PF.

RESULTS

The mean age was 60.5 (33-96) years and mean follow-up was 4.7 (3-12) months. Over 70 % of the patients' initial PF were 2-3 standard deviations below the US population (n = 49; 28). Preoperative PF (p <  0.01), PI (p < 0.01), Depression (p <  0.01), CRF (p <  0.02) and amputation level (p <  0.04) showed significant univariate correlation with postoperative PF. Multivariate model (r = 0.55) showed that the initial PF (p =  0.004), amputation level (p =  0.008), and wound healing status (p =  0.001) predicted postoperative PF.

CONCLUSIONS

Majority of DFU patients present with poor baseline PF. Preoperative PROMIS scores (PF, PI, Depression) are predictive of postoperative PROMIS PF in DFU patients. Postoperative patient's physical function can be assessed by PF_{postoperative} = 29.42 + 0.34 (PF_initial) - 5.87 (Not Healed) - 2.63 (Amputation Category). This algorithm can serve as a valuable tool for predicting post-operative physical function and setting expectations.

Overall Health and the Influence of Physical Therapy on Physical Function Following Total Ankle Arthroplasty

BACKGROUND

The overall health and the importance of physical therapy for people following total ankle arthroplasty (TAA) have been understudied. Our purpose was to characterize the overall health of patients following TAA, and explore the frequency, influence, and patient-perceived value of physical therapy.

METHODS

People who received a TAA participated in this retrospective cohort online survey study. The survey included medical history questions and items from the Patient-Reported Outcomes Measurement Information System (PROMIS) Short Forms. Seven PROMIS domains, reflecting the biopsychosocial model of care (physical, mental, social), were included to examine participant overall health status in comparison to the general population. Items regarding physical therapy participation (yes/no), number of visits, and perceived value (scale 0-10; 10 = extremely helpful) were also included. Descriptive statistics were generated for participant characteristics, PROMIS domain T scores, and physical therapy questions. The influence of participant characteristics or physical therapy visits on PROMIS domain T scores that scored below the population mean were examined with multiple linear regression or ordinal regression.

RESULTS

The response rate was 61% (n=95). Average postoperative time was approximately 3 years (mean [SD]: 40.0 [35.3] months). Physical function and ability to participate in social roles and activities domain T scores were at least 1 SD below the population mean. Most patients received physical therapy (86%; 17.1 [11.0] visits) and found it helpful (7.2 [3.0]). Participant characteristics were minimally predictive of physical function and social participation T scores. Number of physical therapy visits predicted physical function T scores (P = .03).

CONCLUSIONS

Most health domain scores approached the population mean. Physical therapy was perceived to have a high value, and greater visits were related to greater physical function. However, lower physical function and social participation scores suggest that postoperative care directed toward these domains could improve the value of TAA and promote overall health.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Operative Intervention Does Not Change Pain Perception in Patients With Diabetic Foot Ulcers

Researchers investigated pain perception in patients with diabetic foot ulcers (DFUs) by analyzing pre- and postoperative physical function (PF), pain interference (PI), and depression domains of the Patient-Reported Outcome Measurement Information System (PROMIS). They hypothesized that 1) because of painful diabetic peripheral neuropathy (DPN), a majority of patients with DFUs would have high PROMIS PI scores unchanged by operative intervention, and 2) the initially assessed PI, PF, and depression levels would be correlated with final outcomes. Seventy-five percent of patients with DFUs reported pain, most likely because of painful DPN. Those who reported high PI and low PF were likely to report depression. PF, PI, and depression levels were unchanged after operative intervention or healing of DFUs.

Preoperative PROMIS Scores Predict Postoperative PROMIS Score Improvement for Patients Undergoing Hand Surgery

Background: Patient-Reported Outcomes Measurement Information System (PROMIS) can be used alongside preoperative patient characteristics to set postsurgery expectations. This study aimed to analyze whether preoperative scores can predict significant postoperative PROMIS score improvement. Methods: Patients undergoing hand and wrist surgery with initial and greater than 6-month follow-up PROMIS scores were assigned to derivation or validation cohorts, separating trauma and nontrauma conditions. Receiver operating characteristic curves were calculated for the derivation cohort to determine whether preoperative PROMIS scores could predict postoperative PROMIS score improvement utilizing minimal clinically important difference principles. Results: In the nontrauma sample, patients with baseline Physical Function (PF) scores below 31.0 and Pain Interference (PI) and Depression scores above 68.2 and 62.2, respectively, improved their postoperative PROMIS scores with 95%, 96%, and 94% specificity. Patients with baseline PF scores above 52.1 and PI and Depression scores below 49.5 and 39.5, respectively, did not substantially improve their postoperative PROMIS scores with 94%, 93%, and 96% sensitivity. In the trauma sample, patients with baseline PF scores below 34.8 and PI and Depression scores above 69.2 and 62.2, respectively, each improved their postoperative PROMIS scores with 95% specificity. Patients with baseline PF scores above 52.1 and PI and Depression scores below 46.6 and 44.0, respectively, did not substantially improve their postoperative scores with 95%, 94%, and 95% sensitivity. Conclusions: Preoperative PROMIS PF, PI, and Depression scores can predict postoperative PROMIS score improvement for a select group of patients, which may help in setting expectations. Future work can help determine the level of true clinical improvement these findings represent.

A Comparison of PROMIS UE Versus PF: Correlation to PROMIS PI and Depression, Ceiling and Floor Effects, and Time to Completion

PURPOSE

This study aimed to (1) determine the correlation of Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) with PROMIS Upper Extremity (UE) and compare the correlations of PF and UE with PROMIS Pain Interference (PI) and PROMIS Depression; (2) compare the ability of PF and UE to capture health outcomes across the spectrum in patients seeking hand care; and (3) compare the time to completion for PROMIS PF to that for PROMIS UE.

METHODS

Patients presenting to a hand clinic between October, 2015 and October, 2017 were asked to complete PROMIS PF, UE, PI, and Depression computerized adaptive tests. Spearman correlation coefficients (ρ) were calculated between the domains. Ceiling and floor effects and time to completion of each domain were compared.

RESULTS

A total of 20,489 unique visits representing 10,344 patients met inclusion criteria. On average, PROMIS UE demonstrated more functional disability than did PROMIS PF (PF: 43.9 [95% confidence interval (CI), 43.7-44.0] vs UE: 38.5 [95% CI, 38.4-38.7]). PROMIS PF and UE were positively correlated (ρ = 0.79) and both were inversely correlated with PROMIS PI (PF: ρ = -0.72; UE: ρ = -0.72). PROMIS PF and UE were both inversely correlated with PROMIS Depression (PF: ρ = -0.44; UE: ρ = -0.44). PROMIS PF demonstrated better ceiling (0.6% vs 7.5%) and floor effects (0.07% vs 0.4%). The PROMIS UE CAT was completed in about the same time as the PROMIS PF CAT (UE: 59.8 seconds [95% CI, 59.3-60.3 seconds] vs PF: 54.1 seconds [95% CI, 53.8-54.5 seconds]).

CONCLUSIONS

PROMIS PF captures functional outcomes similar to those of the UE domain with better performance (ie, ceiling and floor effects) in patients with hand pathologies.

CLINICAL RELEVANCE

Hand surgeons should consider the trade-off of using PROMIS PF instead of PROMIS UE or vice versa when selecting a domain for patient care. Although PROMIS PF may capture slight variations in function at the extremes better than the current PROMIS UE, this may not be as clinically important as capturing large changes in upper-extremity function more specifically, which PROMIS UE accomplishes.

Asymmetries Identified in Sit-to-Stand Task Explain Physical Function After Hip Fracture

BACKGROUND

Several known demographic and functional characteristics combine to predict physical function after hip fracture. Long-term weight-bearing asymmetries, evident during functional movements after hip fracture, contribute to limited mobility and large asymmetries in muscle function are linked to a high rate of injurious falls. Although postfracture mobility is commonly measured as whole body movement, a force-plate imbedded chair can identify individual limb contributions to an important task like moving from a sitting to standing position. The modified Physical Performance Test (mPPT) and stair climb test (SCT) are reliable, valid measures of function that predict independence after hip fracture. The purpose of this study was to determine to what extent asymmetry during a sit-to-stand task (STST) predicts function (mPPT, 12-step SCT), above and beyond other known predictors.

METHODS

Thirty-one independent community-dwelling older adults, recently discharged from usual care physical therapy (mean [standard deviation], 77.7 [10.5] years, 10 male), within 2 to 8 months postfracture, volunteered for this study. Participants performed an STST on a force-plate-imbedded chair designed to identify individual limb contributions during an STST. Asymmetry magnitude during the STST was determined for each individual. In addition, mPPT and SCT were assessed and regression analyses were performed to determine the contribution of asymmetry to the variance in these physical function scores beyond other factors predicting function.

RESULTS

Demographic factors (sex, time since fracture, repair type, and body mass index) were not significantly related to function in this sample. Age, gait speed, knee extension strength, balance confidence, and functional self-report were each significantly related to both mPPT (r = 0.43-0.86) and SCT (r = 0.40-0.83), and were retained in the regression model. Included variables accounted for 83.4% of the variance in mPPT score, and asymmetry during the STST did not significantly contribute to explaining variability in mPPT (P = .23). Variables in the regression model accounted for 78.0% of the variance in SCT score, and STST asymmetry explained 7.1% (P < .005) of the variance in SCT score.

DISCUSSION

In this small sample, asymmetry contributed significantly to explaining the variability in SCT performance, but not mPPT score. The SCT requires greater unilateral strength and control than the battery of items that comprise the mPPT. This contributes to the disproportionate number of falls occurring during stair ambulation (>10% of all fall-related deaths), relative to the minimal time typically involved in stair negotiation. Our results indicate potential benefit to identifying injured limb asymmetries as they predict function in challenging, high-risk functional tasks after hip fracture.

CONCLUSION

Although gait speed is the best explanator of physical function in older adults after hip fracture, lower extremity asymmetry during an STST provides a unique contribution to explaining high-level ambulatory performance after hip fracture. Efforts to reduce weight-bearing asymmetry during rehabilitation following hip fracture may improve function and recovery.

Minimal Clinically Important Differences for PROMIS Physical Function, Upper Extremity, and Pain Interference in Carpal Tunnel Release Using Region- and Condition-Specific PROM Tools

PURPOSE

Uncertainty exists about what change in Patient-Reported Outcomes Measurement Information System (PROMIS) scores represents a clinically relevant improvement (minimal clinically important difference [MCID]) in hand surgery care. Using a region-specific patient-reported outcome measure (PROM) (Michigan Hand Question [MHQ]) and a condition-specific PROM (Boston Carpal Tunnel Questionnaire [BCTQ]), MCID values were determined for PROMIS Physical Function (PF), Upper Extremity (UE), and Pain Interference (PI) computerized adaptive testing among patients undergoing carpal tunnel release (CTR).

METHODS

Patients undergoing CTR with a single surgeon from November 2014 to April 2017 were asked to complete the BCTQ, MHQ, and PROMIS PF, UE, and PI at each visit. Patients who had completed questionnaires both at a preoperative and either a 6-week or a 3-month postoperative visit were included. The PROMIS PF, UE, and PI MCID values were calculated using previously determined MCID estimates in the literature with both region- (ie, MHQ) and condition-specific (ie, BCTQ) PROM anchors. The PROMIS domain MCID estimates were also determined using the distribution-based method.

RESULTS

A total of 70 patients fit our inclusion criteria. Using MHQ Function and Pain, PROMIS UE, PF, and PI MCIDs were 6.3, 1.8, and -8.9, respectively. Using the average of the 2 BCTQ domains, PROMIS UE, PF, and PI MCIDs were 8.0, 2.8, and -9.7, respectively. Using the distribution-based method, PROMIS UE, PF, and PI MCIDs were 4.2, 2.7, and -4.1, respectively.

CONCLUSIONS

Using region- and condition-specific PROMs, we were able to provide MCID estimates of PROMIS UE, PF, and PI for patients undergoing CTR.

CLINICAL RELEVANCE

Estimating PROMIS UE, PF, and PI MCIDs in CTR using validated region- and condition-specific PROMs provides hand surgeons a way to evaluate CTR outcomes not previously described in the literature. Surgeons should understand that these values are only estimates and future work is needed to verify whether they reflect clinical improvement.

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

BACKGROUND

A recent publication reported preoperative Patient-Reported Outcomes Measurement Instrumentation System (PROMIS) scores to be highly predictive in identifying patients who would and would not benefit from foot and ankle surgery. Their applicability to other patient populations is unknown. The aim of this study was to assess the validation and generalizability of previously published preoperative PROMIS physical function (PF) and pain interference (PI) threshold t scores as predictors of postoperative clinically meaningful improvement in foot and ankle patients from a geographically unique patient population.

METHODS

Prospective PROMIS PF and PI scores of consecutive patient visits to a tertiary foot and ankle clinic were obtained between January 2014 and November 2016. Patients undergoing elective foot and ankle surgery were identified and PROMIS values obtained at initial and follow-up visits (average, 7.9 months). Analysis of variance was used to assess differences in PROMIS scores before and after surgery. The distributive method was used to estimate a minimal clinically important difference (MCID). Receiver operating characteristic curve analysis was used to determine thresholds for achieving and failing to achieve MCID. To assess the validity and generalizability of these threshold values, they were compared with previously published threshold values for accuracy using likelihood ratios and pre- and posttest probabilities, and the percentages of patients identified as achieving and failing to achieve MCID were evaluated using χ² analysis.

RESULTS

There were significant improvements in PF ( P < .001) and PI ( P < .001) after surgery. The area under the curve for PF (0.77) was significant ( P < .01), and the thresholds for achieving MCID and not achieving MCID were similar to those in the prior study. A significant proportion of patients (88.9%) identified as not likely to achieve MCID failed to achieve MCID ( P = .03). A significant proportion of patients (84.2%) identified as likely to achieve MCID did achieve MCID ( P < .01). The area under the curve for PROMIS PI was not significant.

CONCLUSIONS

PROMIS PF threshold scores from published data were successful in classifying patients from a different patient and geographic population who would improve with surgery. If functional improvement is the goal, these thresholds could be used to help identify patients who will benefit from surgery and, most important, those who will not, adding value to foot and ankle health care.

LEVEL OF EVIDENCE

Level II, Prospective Comparative Study.

Muscle Quality Improves with Extended High-Intensity Resistance Training after Hip Fracture

BACKGROUND

Muscle mass deficits endure after hip fracture. Strategies to improve muscle quality may improve mobility and physical function. It is unknown whether training after usual care yields muscle quality gains after hip fracture.

OBJECTIVES

To determine whether muscle quality improves after hip fracture with high-intensity resistance training and protein supplementation.

DESIGN

Case series.

SETTING

University of Utah Skeletal Muscle Exercise Research Facility.

PARTICIPANTS

17 community-dwelling older adults, 3.6+/-1.1 months post-hip fracture, recently discharged from usual-care physical therapy (mean age 77.0+/-12.0 years, 12 female), enrolled.

INTERVENTION

Participants underwent 12 weeks (3x/week) of unilaterally-biased resistance training.

METHODS/MATERIALS

Participants were measured via a 3.0 Tesla whole-body MR imager for muscle lean and intramuscular adipose tissue (IMAT) of the quadriceps before and after resistance training. Peak isometric knee extension force output was measured with an isokinetic dynamometer. Muscle quality was calculated by dividing peak isometric knee extension force (N) by quadriceps lean muscle mass (cm2). In addition, common physical function variables were measured before and after training.

RESULTS

Surgical and nonsurgical lean quadriceps muscle mass improved among participants (mean change: 2.9 cm2+/-1.4 cm2, and 2.7 cm2+/-1.3 cm2, respectively), while IMAT remained unchanged. Peak force improved in the surgical limb by 43.1+/-23N, with no significant change in the nonsurgical limb. Significant gains in physical function were evident after training.

CONCLUSION

Participants recovering from hip fracture demonstrated improvements in muscle mass, muscle strength, and muscle quality in the surgical limb after hip fracture. These were in addition to gains made in the first months after fracture with traditional care. Future studies should determine the impact that muscle quality has on long-term functional recovery in this population.

High-Intensity Multimodal Resistance Training Improves Muscle Function, Symmetry during a Sit-to-Stand Task, and Physical Function Following Hip Fracture

OBJECTIVES

Post rehabilitation, older adults with hip fracture display low vertical ground reaction force (vGRF) on the involved lower extremity during a sit-to-stand task and low physical function. The purpose of this study was to test whether muscle performance, involved side vGRF during a sit-to-stand task, and physical function improved following multimodal high-intensity resistance training, when initiated after usual care (2 to 6 months after hip fracture).

DESIGN

Case series study, 12 weeks extended high-intensity strength training intervention following hip fracture.

SETTING

University hospital outpatient facility.

PARTICIPANTS

Twenty-four community-dwelling older adults (mean age 78.4 years (SD 10.4), 16 female/8 male), 3.6 (SD 1.2) months post-hip fracture and discharged from physical therapy participated. Intervention/Measurement: All participants performed sit-to-stand tasks, muscle performance tests, and modified physical performance test (mPPT) before and after 12 weeks (3x/wk) of training. Variables were compared using paired t-tests.

RESULTS

The vGRF rate of force development (RFD) and magnitude of discrepancy between limb loading during rising phase of sit-to-stand task (AREA) variables improved post-training (RFD ratio = Pre: 0.78 - Post: 0.82, AREA ratio = Pre: 0.79 - Post: 0.86). Surgical leg extension power gains were large (~65%) while strength gains were moderate (~34%); yielding improved symmetry in both strength (Pre: 0.74 - Post: 0.88) and power (Pre: 0.75 - Post: 0.82). Physical function improved pre-training 25 (SD 5.2) to post training 30 (SD 4.3), (p < 0.001).

CONCLUSION

Unique to this study, participants recovering from hip fracture demonstrated improved symmetry in sit-to-stand vGRFs, muscle function, and physical function after training. However, a high percentage of patients continued to experience persistently low vGRF of the involved side compared to previous studies of healthy elderly controls. Developing alternative strategies to improve involved side vGRF may be warranted.

Preoperative PROMIS Scores Predict Postoperative Success in Foot and Ankle Patients

BACKGROUND

The use of patient-reported outcomes continues to expand beyond the scope of clinical research to involve standard of care assessments across orthopedic practices. It is currently unclear how to interpret and apply this information in the daily care of patients in a foot and ankle clinic. We prospectively examined the relationship between preoperative patient-reported outcomes (PROMIS Physical Function, Pain Interference and Depression scores), determined minimal clinical important differences for these values, and assessed if these preoperative values were predictors of improvement after operative intervention.

METHODS

Prospective collection of all consecutive patient visits to a multisurgeon tertiary foot and ankle clinic was obtained between February 2015 and April 2016. This consisted of 16 023 unique visits across 7996 patients, with 3611 new patients. Patients undergoing elective operative intervention were identified by ICD-9 and CPT code. PROMIS physical function, pain interference, and depression scores were assessed at initial and follow-up visits. Minimum clinically important differences (MCIDs) were calculated using a distribution-based method. Receiver operating characteristic (ROC) curves were calculated to determine whether preoperative PROMIS scores were predictive of achieving MCID. Cutoff values for PROMIS scores that would predict achieving MCID and not achieving MCID with 95% specificity were determined. Prognostic pre- and posttest probabilities based off these cutoffs were calculated. Patients with a minimum of 7-month follow-up (mean 9.9) who completed all PROMIS domains were included, resulting in 61 patients.

RESULTS

ROC curves demonstrated that preoperative physical function scores were predictive of postoperative improvement in physical function (area under the curve [AUC] 0.83). Similarly, preoperative pain interference scores were predictive of postoperative pain improvement (AUC 0.73) and preoperative depression scores were also predictive of postoperative depression improvement (AUC 0.74). Patients with preoperative physical function T score below 29.7 had an 83% probability of achieving a clinically meaningful improvement in function as defined by MCID. Patients with preoperative physical function T score above 42 had a 94% probability of failing to achieve MCID. Patients with preoperative pain above 67.2 had a 66% probability of achieving MCID, whereas patients with preoperative pain below 55 had a 95% probability of failing to achieve MCID. Patients with preoperative depression below 41.5 had a 90% probability of failing to achieve MCID.

CONCLUSION

Patient-reported outcomes (PROMIS) scores obtained preoperatively predicted improvement in foot and ankle surgery. Threshold levels in physical function, pain interference, and depression can be shared with patients as they decide whether surgery is a good option and helps place a numerical value on patient expectations. Physical function scores below 29.7 were likely to improve with surgery, whereas those patients with scores above 42 were unlikely to make gains in function. Patients with pain scores less than 55 were similarly unlikely to improve, whereas those with scores above 67 had clinically significant pain reduction postoperatively. Reported prognostic cutoff values help to provide guidance to both the surgeon and the patient and can aid in shared decision making for treatment.

LEVEL OF EVIDENCE

Level II, prognostic study.

2016 J. Leonard Goldner Award - Can Initial PROMIS Scores Predict Outcome for Foot and Ankle Patients?

Category:

Other

Introduction/Purpose:

The use of patient reported outcomes continues to expand beyond the scope of clinical research to involve standard of care assessments across orthopaedic practices. It is currently unclear how to interpret and apply this information in the daily care of patients. We examined the relationship between patient reported outcomes (PROMIS Physical Function, Pain Interference and Depression scores) obtained at initial visit as a predictor of outcome at a minimum of 7 month follow up.

Methods:

Prospective collection of all consecutive patient visits to the University of Rochester Orthopaedic foot and ankle clinic was initiated on April 2015. Data through December 2015 was classified as new or follow up and operative or non-operative based on ICD-9 and CPT codes. 17,019 patient visits were collected on 7,265 patients, of which 4,213 were new patients. PROMIS physical function, pain interference, and depression scores were assessed at initial and follow up visits. Only patients with a minimum of 7 months (mean 8.2) follow up who completed all PROMIS domains were included, resulting in 262 patients (69 operative, 193 non-operative). PROMIS scores are normalized to a US population with an average score of 50 and a standard deviation of 10. Statistical analysis using student t-tests and linear regression were performed to determine if the initial PROMIS scores were predictive of patient reported outcomes at final follow up.

Results:

There were no differences between operative and non-operative treatment groups in initial PROMIS scores or change in scores at follow up (p>0.40). Patients with higher baseline pain were likely to experience less pain over time (r=0.63, p < 0.01). Similarly, patients with higher baseline depression were likely to experience decreased depression over time (r =0.52, p < 0.01). Patients with lower baseline physical function were likely to improve over time whereas patients with higher baseline physical function were likely to worsen over time (r=0.68, p< 0.01). Specifically, all patients with baseline physical function score less than 28 improved over time, while all patients with a score greater than 52 worsened (Figure 1).

Conclusion:

Physical function, pain, and depression trends did not vary between operative and non-operative patients at 8.2 month follow up. Patients with high initial pain and depression were likely to have improvements in pain and depression over time. Similarly, patients with low initial physical function were likely to have improved physical function. However, despite treatment, patients with above average initial physical function did not experience improvement in physical function, suggesting these patients are more challenging to treat. This information demonstrates that baseline patient reported outcomes are predictive of improvement in outcomes over time, and could assist in the treatment decision process.

Utility of Ultrasound for Imaging Osteophytes in Patients With Insertional Achilles Tendinopathy

OBJECTIVES

To examine (1) the validity of ultrasound imaging to measure osteophytes and (2) the association between osteophytes and insertional Achilles tendinopathy (IAT).

DESIGN

Case-control study.

SETTING

Academic medical center.

PARTICIPANTS

Persons with chronic unilateral IAT (n=20; mean age, 58.7±8.3y; 10 [50%] women) and age- and sex-matched controls (n=20; mean age, 57.4±9.8y; 10 [50%] women) participated in this case-control study (N=40).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Symptom severity was assessed using the Foot and Ankle Ability Measure, the Victorian Institute of Sport Assessment-Achilles questionnaire, and the numerical rating scale. Length of osteophytes was measured bilaterally in both groups using ultrasound imaging, as well as on the symptomatic side of the IAT group using radiography. The intraclass correlation coefficient was used to examine the agreement between ultrasound and radiograph measures. McNemar, Wilcoxon signed-rank, and Fisher exact tests were used to compare the frequency and length of osteophytes between sides and groups. Pearson correlation was used to examine the association between osteophyte length and symptom severity.

RESULTS

There was good agreement (intraclass correlation coefficient, ≥.75) between ultrasound and radiograph osteophyte measures. There were no statistically significant differences (P>.05) in the frequency of osteophytes between sides or groups. Osteophytes were larger on the symptomatic side of the IAT group than on the asymptomatic side (P=.01) and on the left side of controls (P=.03). There was no association between osteophyte length and symptom severity.

CONCLUSIONS

Ultrasound imaging is a valid measure of osteophyte length, which is associated with IAT. Although a larger osteophyte indicates tendinopathy, it does not indicate more severe IAT symptoms.

Weight-bearing asymmetry in individuals post-hip fracture during the sit to stand task

BACKGROUND

Individuals post hip fracture decrease force on the involved limb during sit to stand tasks, creating an asymmetry in vertical ground reaction force. Joint specific differences that underlie asymmetry of the vertical ground reaction force are unknown. The purpose of this study was to compare differences in vertical ground reaction force variables and joint kinetics at the hip and knee in participants post-hip fracture, who were recently discharged from homecare physical therapy to controls.

METHODS

Forty-four community-dwelling older adults, 29 who had a hip fracture and 15 elderly control participant's completed the sit to stand task on an instrumented chair with 3 force plates. T-tests were used to compare clinical tests (Berg Balance Scale, activity balance confidence and gait speed, isokinetic knee strength) and vertical ground reaction force variables. Two-way analyses of variance compared vertical ground reaction force variables and kinetics at the hip and knee between hip fracture and elderly control groups. Pearson correlation coefficients were used to determine correlations between clinical and vertical ground reaction force variables.

FINDINGS

Vertical ground reaction force variables were significantly lower on the involved side for the hip fracture group compared to the uninvolved side and controls. Lower involved side hip and knee moments and power contributed to lower involved side vertical ground reaction force. Vertical ground reaction force variables and strength had moderate to high correlations with clinical measures.

INTERPRETATION

Uninvolved side knee moments and powers were the largest contributors to asymmetrical vertical ground reaction force in participants post-hip fracture. The association of vertical ground reaction force variables and clinical measures of function suggesting reducing vertical ground reaction force asymmetry may contribute to higher levels of function post-hip fracture. Functional and strength training should target the involved knee to reduce vertical ground reaction force asymmetry.

Pre- and postoperative gait analysis following conversion of tibiotalocalcaneal fusion to total ankle arthroplasty

Level of Evidence: V, Expert Opinion

Deep posterior compartment strength and foot kinematics in subjects with stage II posterior tibial tendon dysfunction

BACKGROUND

Tibialis posterior muscle weakness has been documented in subjects with Stage II posterior tibial tendon dysfunction (PTTD) but the effect of weakness on foot structure remains unclear. The association between strength and flatfoot kinematics may guide treatment such as the use of strengthening programs targeting the tibialis posterior muscle.

MATERIALS AND METHODS

Thirty Stage II PTTD subjects (age; 58.1 +/- 10.5 years, BMI 30.6 +/- 5.4) and 15 matched controls (age; 56.5 +/- 7.7 years, BMI 30.6 +/- 3.6) volunteered for this study. Deep Posterior Compartment strength was measured from both legs of each subject and the strength ratio was used to compare each subject's involved side to their uninvolved side. A 20% deficit was defined, a priori, to define two groups of subjects with PTTD. The strength ratio for each group averaged; 1.06 +/- 0.1 (range 0.87 to 1.36) for controls, 1.06 +/- 0.1 (range, 0.89 to 1.25), for the PTTD strong group, and 0.64 +/- 0.2 (range 0.42 to 0.76) for the PTTD weak group. Across four phases of stance, kinematic measures of flatfoot were compared between the three groups using a two-way mixed effect ANOVA model repeated for each kinematic variable.

RESULTS

Subjects with PTTD regardless of group demonstrated significantly greater hindfoot eversion compared to controls. Subjects with PTTD who were weak demonstrated greater hindfoot eversion compared to subjects with PTTD who were strong. For forefoot abduction and MLA angles the differences between groups depended on the phase of stance with significant differences between each group observed at the pre-swing phase of stance.

CONCLUSION

Strength was associated with the degree of flatfoot deformity observed during walking, however, flatfoot deformity may also occur without strength deficits.

CLINICAL RELEVANCE

Strengthening programs may only partially correct flatfoot kinematics while other clinical interventions such as bracing or surgery may also be indicated.

Patient factors in the selection of operative versus nonoperative treatment for posterior tibial tendon dysfunction

BACKGROUND

The influence of demographic, medical history, and treatment variables on the maintenance of nonoperative care or progression to operative intervention in Posterior Tibial Tendon Dysfunction (PTTD) was explored. This retrospective study compared demographic, medical history and treatment variables between operative and nonoperative care in subjects with PTTD.

MATERIALS AND METHODS

Charts with the ICD-9 codes (726.72, 726.90) and brace distribution records for 2005 and 2006 were used to identify subjects. From these, 166 of 606 charts included documentation of PTTD. Variables were grouped into three categories including demographics (Age, body mass index, gender and working status), medical (stage, symptom duration, pain at initial evaluation, and past treatments) and treatment (initial brace, length of care episode, and brace change). Statistical comparisons between subjects treated nonoperatively and operatively were made. Significant variables were entered into a logistic regression analysis. Accuracy (sensitivity/specificity) was assessed by examining the success of predicting which subjects were treated operatively or nonoperatively.

RESULTS

Of the 166 subjects, 125 (75.4%) received nonoperative care and 41 (24.6%) operative care. Nine variables distinguished the operative from the nonoperative group (p<0.05): including BMI, work status, stage, symptom duration, prior orthotic use, prior injection, custom brace, brace changes, and length of care episode. The logistic regression model identified BMI, symptom duration, prior cortisone injections, and prior orthotic use as significant and resulted in a specificity of 95.4% and sensitivity of 38.2%.

CONCLUSION

This retrospective analysis provides a patient profile of factors in the success of nonoperative care in PTTD.

Ankle and foot kinematics associated with stage II PTTD during stance

BACKGROUND

Subjects with stage II posterior tibial tendon dysfunction (PTTD) exhibit abnormal foot kinematics; however, how individual segment kinematics (hindfoot (HF) or first metatarsal (first MET) segments) influence global foot kinematics is unclear. The purpose of this study was to compare foot and ankle kinematics and sagittal plane HF and first MET segment kinematics between stage II PTTD and controls.

MATERIALS AND METHODS

Thirty patients with stage II PTTD and 15 healthy controls were evaluated. Kinematic data from the tibia, calcaneus, and first MET were collected during walking using three dimensional motion analysis techniques. A three-segment foot model (HF, calcaneus; first MET, first metatarsal, and tibia) was used to calculate relative angles (ankle, HF relative to tibia; midfoot, first MET relative to HF) and segment angles (HF and first MET relative to the global). A mixed effect ANOVA model was utilized to compare angles between groups for each variable.

RESULTS

Patients with PTTD showed greater ankle plantarflexion (p = 0.02) by 6.8 degrees to 8.4 degrees prior to or at 74% of stance; greater HF eversion (p < 0.01) across stance (mean difference = 4.5 degrees); and greater first MET dorsiflexion (p < 0.01) across stance (mean difference = 8.8 degrees). HF and first MET segment angles revealed greater HF dorsiflexion (p = 0.01) during early stance and greater first MET dorsiflexion (p = 0.001) across stance.

CONCLUSION

Abnormal HF and first MET segment kinematics separately influence both ankle and midfoot movement during walking in subjects with stage II PTTD.

CLINICAL RELEVANCE

These abnormal kinematics may serve as another measure of response to clinical treatment and/or guide for clinical strategies (exercise, orthotics, and surgery) seeking to improve foot kinematics.

The effect of Stage II posterior tibial tendon dysfunction on deep compartment muscle strength: a new strength test

BACKGROUND

The purpose of this study was to compare isometric subtalar inversion and forefoot adduction strength in subjects with Stage II posterior tibial tendon dysfunction (PTTD) to controls.

MATERIALS AND METHODS

Twenty four subjects with Stage II PTTD and fifteen matched controls volunteered for this study. A force transducer (Model SML-200, Interface, Scottsdale, AZ) was connected with a resistance plate and oscilloscope (TDS 410A, Tektronix, Beaverton, OR) to the foot. Via the oscilloscope, subjects were given feedback on the amount of force produced and muscle activation of the anterior tibialis (AT) muscle. Subjects were instructed to maintain a plantar flexion force while performing a maximal voluntary subtalar inversion and forefoot adduction effort. A two-way ANOVA model with the factors including, side (involved/uninvolved) and group (control/PTTD) was used.

RESULTS

The PTTD group on the involved side showed significantly decreased subtalar inversion and foot adduction strength (0.70 +/- 0.24 N/Kg) compared to the uninvolved side (0.94 +/- 0.24 N/Kg) and controls (involved side = 0.99 +/- 0.24 N/Kg, uninvolved side = 0.97 +/- 0.21 N/Kg). The average AT activation was between 11% to 17% for both groups, however, considerable variability in subjects with PTTD.

CONCLUSION

These data confirm a subtalar inversion and forefoot adduction strength deficit by 20% to 30% in subjects with Stage II PTTD. Although isolating the PT muscle is difficult, a test specific to subtalar inversion and forefoot adduction demonstrated the weakness in this population.

Subtalar neutral position as an offset for a kinematic model of the foot during walking

The lack of a common reference position when defining foot postures may underestimate the ability to differentiate foot function in subjects with pathology. The effect of using the subtalar neutral (STN) position as an offset for both rearfoot and forefoot through comparison of the kinematic walking patterns of subjects classified as normal (n=7) and abnormally pronated (n=14) foot postures was completed. An Optotrak Motion Analysis System (Northern Digital, Inc.) integrated with Motion Monitor Software (Innovative Sports, Inc.) was used to track three-dimensional movement of the leg, rearfoot and first metatarsal segments. Intrarater reliability of positioning the foot into STN using clinical guidelines was determined for a single rater for 21 subjects. Walking data were subsequently compared before and after an offset was applied to the rearfoot and first metatarsal segments. Repeated measures of foot positioning found the STN position to be highly repeatable (intraclass correlation coefficients>0.9), with peak errors ranging from 1.9 degrees to 4.3 degrees . Utilizing STN as the offset resulted in a significant increase in rearfoot eversion (p=0.019) during early stance, and greater first metatarsal dorsiflexion (p<0.007) across stance in the pronated foot groups that was not observed prior to applying the offset. When applied to subjects with differing foot postures, the selection of a common reference position that is both clinically appropriate and reliable may distinguish kinematic patterns during walking that are consistent with theories of abnormal pronation.

The development of a protoplanetary disk from its natal envelope

Class 0 protostars, the youngest type of young stellar objects, show many signs of rapid development from their initial, spheroidal configurations, and therefore are studied intensively for details of the formation of protoplanetary disks within protostellar envelopes. At millimetre wavelengths, kinematic signatures of collapse have been observed in several such protostars, through observations of molecular lines that probe their outer envelopes. It has been suggested that one or more components of the proto-multiple system NGC 1333-IRAS 4 (refs 1, 2) may display signs of an embedded region that is warmer and denser than the bulk of the envelope. Here we report observations that reveal details of the core on Solar System dimensions. We detect in NGC 1333-IRAS 4B a rich emission spectrum of H2O, at wavelengths 20-37 microm, which indicates an origin in extremely dense, warm gas. We can model the emission as infall from a protostellar envelope onto the surface of a deeply embedded, dense disk, and therefore see the development of a protoplanetary disk. This is the only example of mid-infrared water emission from a sample of 30 class 0 objects, perhaps arising from a favourable orientation; alternatively, this may be an early and short-lived stage in the evolution of a protoplanetary disk.

Analysis of EMG patterns of control subjects and subjects with ACL deficiency during an unanticipated walking cut task

PURPOSE

The purpose of this study was to describe the muscle activation patterns of the vastus lateralis (VL), medial hamstrings (MH) and lateral hamstrings (LH) associated with subjects that were anterior cruciate ligament (ACL) deficient and controls.

METHODS

A total of 54 subjects participated in this study including 25 ACL deficient subjects subdivided into copers (n=9) and non-copers (n=16) using clinical criteria. Muscle activation patterns were recorded at 1000 Hz during an unanticipated side step cut task. The root mean square processed data (time constant 11 ms) were ensemble averaged from 20% of stance before heel strike to toe off. Using the first five harmonics of the Fourier Coefficients as features, muscle activation patterns were divided using a cluster analysis algorithm.

RESULTS

A majority (76-93%) of control subjects used three muscle activation patterns for each muscle. The coper group preferentially used a particular VL and MH activation pattern >2 times more frequently than controls. The non-coper group also preferentially used a MH activation pattern >2 times more frequently than controls and utilized a unique MH and LH activation pattern, distinct from the copers and controls.

CONCLUSIONS

Specific muscle activation patterns distinguish subsets of subjects that are healthy and injured, suggesting possible patterns of muscle activation that contribute to coping status.

Influence of anticipation on movement patterns in subjects with ACL deficiency classified as noncopers

STUDY DESIGN

Two-factor, mixed experimental design.

OBJECTIVES

To compare movement patterns of subjects who are anterior cruciate ligament (ACL) deficient and classified as noncopers to controls during early stance of anticipated and unanticipated straight and cutting tasks.

BACKGROUND

Altered neuromuscular control of subjects that are ACL deficient and noncoper theoretically influences movement patterns during unanticipated tasks.

METHODS AND MEASURES

The study included 16 subjects who are ACL deficient, classified as noncopers, and 20 healthy controls. Data were collected using an Optotrak Motion Analysis System and force plate integrated with Motion Monitor Software to generate knee joint angles, moments, and power. Each testing session included anticipated tasks, straight walking task (ST), and 45 degrees side-step cutting tasks (SSC), followed by a set of unexpected straight walking (STU) and unexpected sidestep cutting (SSCU) tasks in a random order. For all tasks speed was maintained at 2 m/s. Peak knee angle, moment, and power variables during early stance were compared using 2-way mixed-effects ANOVA models.

RESULTS

For both the straight and sidestep tasks, the noncoper group did not show a dependence on whether the task was anticipated or unanticipated (group-by-condition interaction) for the knee angle (straight, P = .067; side-step cutting, P = .103), moment (straight, P = .079; side-step cutting, P = .996), and powers (straight, P = .181; side-step cutting, P = .183) during the loading response phase. However, during both straight and side-step cutting tasks, the subjects in the noncoper group used significantly lower knee flexion angles (straight, P = .002; side-step cutting, P = .019), knee moments (straight, P = .005; side-step cutting, P < .001), and knee powers (straight, P = .013; side-step cutting, P <.001).

CONCLUSIONS

This study suggests subjects that are ACL deficient and classified as noncopers use a common abnormal movement pattern of lower knee extensor loading even during unanticipated tasks.

The NASA Spitzer Space Telescope

The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

Comparison of frontal plane trunk kinematics and hip and knee moments during anticipated and unanticipated walking and side step cutting tasks

BACKGROUND

Frontal plane trunk and lower extremity adjustments during unanticipated tasks are hypothesized to influence hip and knee neuromuscular control, and therefore, contribute to anterior cruciate ligament (ACL) injury risk. The aims of this study were to examine frontal plane trunk/hip kinematics and hip and knee moments (measures of neuromuscular control) during unanticipated straight and side step cut tasks.

METHODS

Kinematic and kinetic variables were collected while subjects performed two anticipated tasks, including walking straight (ST) and side step cutting (SS), and two unanticipated tasks (STU and SSU). Foot placement, thorax-pelvis-hip kinematic variables and hip and knee moments were calculated over the first 30% of stance.

FINDINGS

Hip abduction angles and knee moments were significantly affected by task and anticipation. Hip abduction angles decreased, by 4.0-7.6 degrees , when comparing the SSU task to the ST, STU and SS tasks. The hip abduction angles were associated with foot placement and lateral trunk orientation.

INTERPRETATION

Hip abduction angles and foot placement, not lateral trunk flexion influence trunk orientation. Anticipation influences hip and knee neuromuscular control and therefore may guide the development of ACL prevention strategies.

Knee and hip angle and moment adaptations during cutting tasks in subjects with anterior cruciate ligament deficiency classified as noncopers

STUDY DESIGN

Two-factor mixed-design study, with factors including group (control and noncoper) and task (sidestep, crossover, and straight).

OBJECTIVES

To compare the knee and hip joint angles and moments of control subjects and subjects with an anterior cruciate ligament (ACL) deficient knee classified as noncopers, during a sidestep, crossover, and straight-ahead task.

BACKGROUND

Subjects with ACL deficiency primarily note difficulty with cutting tasks as opposed to straight-ahead tasks. Yet, previous studies have primarily focused on straight-ahead tasks.

METHODS AND MEASURES

Fifteen subjects with ACL deficiency classified as noncopers, based on the number of giving-way episodes (>1) and global question of knee function (<60%), were included in this study. These subjects (10 male, 5 female; age range, 18-49 years) were compared to a healthy control group (7 male, 7 female; age range, 19-47 years). Position data collected at 60 Hz were combined with anthropometric and ground reaction force data collected at 420 Hz to estimate 3-dimensional knee and hip joint angles and moments. All subjects performed 3 tasks including a step and 45 degrees sidestep cut, step and 45 degrees crossover cut, and step and proceed straight. Two-way mixed-model ANOVAs were used to compare peak angle and moment variables between 10% to 30% of stance.

RESULTS

The ACL-deficient noncoper group had 1.8 degrees to 5.7 degrees less knee flexion angle compared to the control group across tasks (P<.043). The ACL-deficient noncoper group used 22% to 27% lower knee extensor moment during weight acceptance compared to the control group (P<.001). The sagittal plane hip extensor moments were 34% to 39% higher in the ACL-deficient noncoper group compared to the control group (P<.025). Hip frontal (P<.037) and transverse plane (P<.04) moments also distinguished the ACL-deficient noncoper from the control group.

CONCLUSIONS

This study suggests that individuals who do not cope well after ACL injury rely on a hip control strategy during cutting tasks.

The use of sequential MR image sets for determining tibiofemoral motion: reliability of coordinate systems and accuracy of motion tracking algorithm

The use of magnetic resonance imaging has been proposed by many investigators for establishment of joint reference systems and kinematic tracking of musculoskeletal joints. In this study, the intraobserver and interobserver reliability of a strategy to establish anatomic reference systems using manually selected fiducial points were quantified for seven sets of MR images of the human knee joint. The standard error of the measurement of the intraobserver and interobserver errors were less than 2.6 degrees, and 1.2 mm for relative tibiofemoral orientation and displacement, respectively. An automated motion tracking algorithm was also validated with a controlled motion experiment in a cadaveric knee joint. The controlled displacements and rotations prescribed in our motion tracking validation were highly correlated to those predicted (Pearson's correlation = 0.99, RMS errors = 0.39 mm, 0.38 degree). Finally, the system for anatomic reference system definition and motion tracking was demonstrated with a set of MR images of in vivo passive flexion in the human knee.

Heteroarotinoids inhibit head and neck cancer cell lines in vitro and in vivo through both RAR and RXR retinoic acid receptors

A class of less toxic retinoids, called heteroarotinoids, was evaluated for their molecular mechanism of growth inhibition of two head and neck squamous cell carcinoma (HNSCC) cell lines SCC-2 and SCC-38. A series of 14 heteroarotinoids were screened for growth inhibition activity in vitro. The two most active compounds, one that contained an oxygen heteroatom (6) and the other a sulfur heteroatom (16), were evaluated in a xenograph model of tumor establishment in nude mice. Five days after subcutaneous injection of 10(7) SCC-38 cells, groups of 5 nu/nu mice were gavaged daily (5 days/week for 4 weeks) with 20 mg/kg/day of all-trans-retinoic acid (t-RA, 1), 10 mg/kg/day of 6, 10 mg/kg/day of 16, or sesame oil. After a few days, the dose of t-RA (1) was decreased to 10 mg/kg/day to alleviate the side effects of eczema and bone fracture. No significant toxic effects were observed in the heteroarotinoid groups. All three retinoids caused a statistically significant reduction in tumor size as determined by the Student t-test (P < 0. 05). Complete tumor regression was noted in 3 of 5 mice treated with t-RA (1), 4 of 5 mice treated with 16, 1 of 5 mice treated with 6, and 1 of 5 mice treated with sesame oil. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to determine that the expression levels of RARalpha, RXRalpha, and RXRbeta were similar in the two cell lines, while RARbeta expression was higher in SCC-2 over SCC-38, and RARgamma expression was higher in SCC-38 over SCC-2. Receptor cotransfection assays in CV-1 cells demonstrated that 16 was a potent activator of both RAR and RXR receptors, while 6 was selective for the RXR receptors. Transient cotransfection assays in CV-1 cells using an AP-1 responsive reporter plasmid demonstrated that t-RA (1), 6, and 16 each inhibited AP-1-driven transcription in this cell line. In conclusion, the growth inhibition activity of the RXR-selective 6 and the more potent growth inhibition activity of the RAR/RXR pan-agonist 16 implicate both RARs and RXRs in the molecular mechanism of retinoid growth inhibition. Moreover, the chemoprevention activity and the lack of toxicity of heteroarotinoids demonstrate their clinical potential in head and neck cancer chemoprevention.

Management of cervical lymph nodes in squamous carcinomas of the head and neck

Due to the overwhelming prognostic significance of regional metastases, proper management of cervical lymph nodes in cases of squamous cell carcinoma of the head and neck is essential for an optimal outcome. Better understanding of the predictability of incidence and patterns of metastases of these tumors in recent years has led us away from the radical neck dissection as the only surgical therapeutic or staging procedure done on the neck. Recent studies suggest that selective removal of lymph node groups at risk in clinically negative necks, or modified neck dissections that save important structures, like the jugular vein, XI nerve, and sternocleidomastoid muscle, in clinically positive necks, are appropriate in many patients. Careful selection of the type of neck dissection and judicious use of postoperative radiation therapy can optimize cure rates as well as functional and cosmetic results.

Accumulation of the p53 tumor-suppressor gene product in oral leukoplakia

OBJECTIVES

(1) To determine whether the protein of the suppressor gene p53 accumulates in leukoplakia of the oral cavity in individuals who use snuff; and (2) to determine whether a correlation exists between the accumulation of p53 protein and the degree of epithelial dysplasia present in oral leukoplakia.

DESIGN

Retrospective analysis of archival tissue specimens.

SETTING

The University Hospital, a tertiary referral hospital affiliated with the Oklahoma University Medical Center, Oklahoma City, Oklahoma.

PATIENTS

In the first part of the study, biopsy specimens of leukoplakia from 12 persons who used snuff were compared with specimens from uninvolved oral mucosa of the same persons and with biopsy specimens from 12 nontobacco-using persons. In the second part of the study, accumulation of p53 protein was determined in 42 archival paraffin-embedded specimens from oral leukoplakia and correlated with the degree of epithelial dysplasia.

METHODS

Accumulation of p53 protein was assessed by immunoperoxidase staining with four different primary antibodies. Positive cells were counted in five consecutive high-power fields.

RESULTS

In part one, the average number of positive cells in the leukoplakia of snuff-users (21.89 +/- 4.33; mean +/- SE) was higher than that of normal-appearing mucosa (4.00 +/- 1.0; p < 0.05) and that of nontobacco-using controls (7.00 +/- 5.04). In part two, the average number of positive cells was higher in the moderately dysplastic (140.36 +/- 30.03) and severely dysplastic lesions (232.86 +/- 26.85) than in the mildly dysplastic lesions (14.53 +/- 3.33; p < 0.05). The correlation between the degree of epithelial dysplasia and the number of cells positive is strong (Spearman's correlation coefficient = 0.853).

CONCLUSIONS

The accumulation of p53 protein in leukoplakia of snuff-users is higher than in normal-appearing oral mucosa from both snuff-users and nontobacco-using controls. A strong correlation exists between the degree of epithelial dysplasia present in oral leukoplakia and the number of cells staining positive for p53. The accumulation of p53 protein holds potential as an intermediate end point in studies of chemoprevention of oral cancer.

Do histocompatibility antigens antigence influence the risk of head and neck carcinoma?

Associations were sought between specific histocompatibility antigens (HLA) of the human major histocompatibility complex and the incidence of head and neck squamous cell carcinoma (SqCC). Seventy sequential patients with SqCC and 217 control subjects from the same geographic region were typed for HLA-A, HLA-B, and HLA-DR loci. These results were compared. Multivariate statistical analysis using stepwise logistic regression revealed significant associations between the incidence of SqCC and HLA-B14, HLA-DR3, and HLA-DR4 as well as smoking and the sex-smoking interaction. The authors concluded that certain host factors, including genetic constitution, and behavioral characteristics (i.e., smoking) as well as tumor biology, can influence the development of SqCC. The mechanism(s) of these associations may involve as yet undefined relationships between HLA region genes and the immune response.

Sudden bilateral profound hearing loss resulting from meningeal carcinomatosis

SBPHL is a rare manifestation of hearing loss. Patients with SBPHL should have a thorough evaluation for meningeal carcinomatosis as the cause, including a complete neurologic evaluation, CT scan, and, probably, MRI. If MC is highly suspected, an LP is necessary. Because the diagnosis of MC can be confirmed only by the presence of malignant cells in the CSF, multiple LPs may be necessary to find them. Although MC should be strongly considered in the differential diagnosis of SBPHL, MC should also be considered with other patterns of eighth cranial nerve involvement, especially in patients with a history of malignancy. These patterns include unilateral hearing loss associated with tinnitus, unilateral hearing loss rapidly progressing to severe bilateral involvement, audiologic and caloric studies that show eighth cranial nerve impairment, and facial nerve palsy associated with hearing loss. The prognosis for MC is poor, although intraventricular chemotherapy and whole brain radiotherapy can provide significant palliation.

HLA class I and class II antigen expression on squamous cell carcinoma of the head and neck

We compared human major histocompatibility (HLA) class I and class II antigen expression on squamous cell carcinoma of the head and neck with that on normal mucosa. Frozen sections of a consecutive series of 30 squamous cell carcinomas were stained with the monoclonal antibodies W6/32 (class I) and anti-DR (class II) using an immunoperoxidase technique. Normal mucosa showed class I and class II expression in the basal layers only. Class I expression on tumors was diffuse in 87%, patchy in 10%, and scattered in 3%. Class II expression on tumors was diffuse in 20%, patchy in 53%, scattered in 20%, and absent in 7%. Patterns of expression did not correlate significantly with clinical parameters, including survival, except that class II diffuse and patchy patterns were found to correlate with more poorly differentiated tumors.

Advanced head and neck cancer: low-dose, split-course radiation therapy and simultaneous infusion of 5-fluorouracil and cisplatin

Twenty-three patients with advanced untreated head and neck cancer, nine patients with recurrent cancer, and six patients with recurrent cancer who underwent surgery and had postoperative persistence of tumor were treated with three 2-week courses of irradiation (1,500 cGy in 10 fractions each) concurrently with cisplatin and a 5-day infusion of 5-fluorouracil. A fourth 2-week course of irradiation (2,000 cGy in 10 fractions) brought the final tumor dose to 6,500 cGy. Twenty patients in the untreated group and three patients in the recurrent group (33%) had a complete response. There were 10 local recurrences in the untreated group (43%), seven in the recurrent group (78%), and three in the persistent group (50%). At 17 months after the start of treatment, the survival rate for the untreated patients was 51%, for the patients in the recurrent group it was 11%, and for the patients in the persistent group it was 20% (P = .03). Most patients experienced toxicity, including nausea, vomiting, weight loss, and mucositis. Clinical trials are necessary to determine whether simultaneous chemotherapy and radiation therapy is an improved method of treatment for advanced head and neck cancer.

Suction-assisted lipectomy in the management of obstructive sleep apnea

Suction-assisted lipectomy is a valuable method of aesthetic recontouring of the neck. We report the successful use of suction-assisted lipectomy as an adjunctive procedure at the time of tracheostomy in the treatment of obese patients with severe obstructive sleep apnea. This functional procedure helps to maintain tracheostomy patency during sleep.

Effect of helium concentration on experimental upper airway obstruction

This study investigates the effect of helium concentration in inspired gas on resistance to breathing during experimental upper airway obstruction. Obstruction was modeled by use of a series of four polyvinyl endotracheal tubes narrowed progressively in their midportions with C clamps. Percentage ratios of helium-oxygen gas mixtures were 0:100, 40:60, 60:40, and 80:20. Gas flow was provided by two methods: 1) nontidal flow from compressed gas tanks from which resistance was calculated from pressure and flow measurements, and 2) tidal respiratory flow from human volunteers from whom respiratory effort was evaluated by using airway pressure measurements integrated over 90-second trial periods. The results derived from both methods demonstrated that the effect of helium in reducing resistance and pressure in an obstructed airway is linear (p less than .016) and inversely proportional to helium concentration. Reductions in resistance and pressure were larger for the tighter obstructions (p less than .007). As helium was added to the gas mixture (from 0% to 80%), resistance and airway pressure measurements dropped 42% and 58%, respectively. The major conclusions are that 1) even low concentrations of helium may have therapeutic value and 2) helium is effective only for more severe obstructions.

The tooth as a foreign body in soft tissue after head and neck trauma

Thorough evaluation of dentition is important in the management of craniofacial trauma. Avulsed or fractured teeth in the pulmonary and gastrointestinal tracts can lead to serious complications that are well described. However, the penetration of avulsed teeth into soft tissues of the head and neck is unusual and may not be recognized. Two cases in which a tooth became a foreign body in these soft tissues are illustrative. One patient had bronchoscopy for possible aspiration of an avulsed maxillary canine; it was later found embedded in the premaxillary tissues. The other patient had a right mandibular molar propelled into the posterior triangle of the left side of the neck. Physicians must be aware of dental injury resulting from facial trauma and account for all teeth as part of their evaluation, keeping an open mind as to where a missing tooth might be located.

Modulation of human leukocyte antigen class I expression by gamma interferon in head and neck cancer cell lines

One possible mechanism explaining the action of interferon (IFN) on squamous cell carcinoma (SqCC) of the head and neck is the modulation of major histocompatibility antigen expression on tumor cells. We tested the ability of gamma interferon (gamma-IFN) to modulate major histocompatibility class I antigens and beta 2-microglobulin (beta 2-M) on two carcinoma cell lines derived from SqCC of the head and neck. Major histocompatibility class I antigens and beta 2-M were detected using a two-step immunochemical stain; antigen expression was quantified using flow cytometry. gamma-IFN increased constitutive antigen expression by as much as five times on both cell lines. Maximum modulation was seen within 72 hours of exposure to gamma-IFN at clinically attainable doses (10 U/mL to 100 U/mL). The presence of gamma-IFN in cell cultures was necessary for continued modulation of surface antigens. These findings suggest a possible mechanism of action and encourage further clinical trials with gamma-IFN.

Epistaxis: medical versus surgical therapy: a comparison of efficacy, complications, and economic considerations

A retrospective review of 4 years experience with over 32 epistaxis patients requiring hospitalization and using a standard medical or surgical therapy for control is presented. Medical therapy included the use of anterior nasal packing alone or in association with intranasal and nasopharyngeal balloon tamponade. Surgical therapy, for the most part, consisted of ethmoid and/or internal maxillary artery ligations. Most patients were treated initially with packing and balloons. Fifty-two percent of the group failed this therapy and required ligations for control. The patients who did not come to operation had fewer complications, a shorter average hospital stay, and lower average cost of hospitalization without increased risk of future epistaxis. An analysis is made comparing the results, complications, and financial implications of these two approaches.

Further clinical experience with the silicone tracheal cannula in obstructive sleep apnea

We report on the perioperative and postoperative course of 47 patients with severe obstructive sleep apnea, who underwent tracheostomy by use of a silicone tracheal cannula developed by Dr. William Montgomery. Our initial experience with the first 20 of these patients (presented in 1982) was quite favorable because of the ease of insertion and care, a high degree of patient acceptance, and infrequent complications. With our current sample, larger experience, and more prolonged follow-up, we noted that symptomatic granulation tissue formation, with or without wound infection, occurred more frequently than was initially appreciated. In 21% (10 of 47) of the cases, the only way to resolve this problem was to remove this device and replace it permanently with a metal (or other type) tracheostomy tube. Other complications included tracheal narrowing and cannula malpositioning and fragmentation. This full report lists in detail the incidence of complications associated with our use of this cannula and modifications which may lessen these.

Infrared Astronomy After IRAS

The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth-the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.

Early Results from the Infrared Astronomical Satellite

For 10 months the Infrared Astronomical Satellite (IRAS) provided astronomers with what might be termed their first view of the infrared sky on a clear, dark night. Without IRAS, atmospheric absorption and the thermal emission from both the atmosphere and Earthbound telescopes make the task of the infrared astronomer comparable to what an optical astronomer would face if required to work only on cloudy afternoons. IRAS observations are serving astronomers in the same manner as the photographic plates of the Palomar Observatory Sky Survey; just as the optical survey has been used by all astronomers for over three decades, as a source of quantitative information about the sky and as a "roadmap" for future observations, the results of IRAS will be studied for years to come. IRAS has demonstrated the power of infrared astronomy from space. Already, from a brief look at a miniscule fraction of the data available, we have learned much about the solar system, about nearby stars, about the Galaxy as a whole and about distant extragalactic systems. Comets are much dustier than previously thought. Solid particles, presumably the remnants of the star-formation process, orbit around Vega and other stars and may provide the raw material for planetary systems. Emission from cool interstellar material has been traced throughout the Galaxy all the way to the galactic poles. Both the clumpiness and breadth of the distribution of this material were previously unsuspected. The far-infrared sky away from the galactic plane has been found to be dominated by spiral galaxies, some of which emit more than 50 percent and as much as 98 percent of their energy in the infrared-an exciting and surprising revelation. The IRAS mission is clearly the pathfinder for future missions that, to a large extent, will be devoted to the discoveries revealed by IRAS.

Immunomodulatory activity in regional lymph nodes

This study is, to our knowledge, the first attempt to evaluate cellular immune mechanisms in regional lymph nodes of patients with head and neck cancer. Twenty lymph nodes from eight patients with stage III-IV squamous cell carcinoma were evaluated using an in vitro culture system. The T-cell mitogenic (concanavalin A) response of patients' peripheral blood mononuclear cells was modulated by the addition of cells from regional lymph nodes removed at neck dissection. Modulatory activity showing augmentation was significantly correlated with the size of the primary tumor and histopathologic grade of the tumor. Modulatory activity did not correlate with the histologic pattern of lymph node reactivity. Although these relationships suggest that regional immunity may be important in tumor-host interactions, further study is necessary to establish their biologic and prognostic importance.

Jupiter: Its Infrared Spectrum from 16 to 40 Micrometers

Spectral measurements of the thermal radiation from Jupiter in the band from 16 to 40 micrometers are analyzed under the assumption that pressure-broadened molecular hydrogen transitions are responsible for the bulk of the infrared opacity over most of this spectral interval. Both the vertical pressure-temperature profile and the molecular hydrogen mixing ratio are determined. The derived value ofthe molecular hydrogen mixing ratio, 0.89 +/- 0.11, is consistent with the solar value of 0.86.

Black paints for far infrared cryogenic use

A cryogenic paint which remains absorptive throughout the infrared has been developed. The paint exhibits excellent surface stability at liquid helium temperature and is resistant to abrasion and flaking. Measurements in a specially constructed cryogenic integrating sphere indicate that the paint is ~92-100% absorptive in the 70-130-micro range. Additional broadband measurements at 60 micro-130 micro, 18 micro-25micro, and 400 micro-1 mm indicate that the paint is ~95% absorptive.

Far-Infrared Observations of the Night Sky

We have flown a telescope cooled to liquid-helium temperatures and made far-infrared observations of the night sky. A gallium-doped germanium detector, sensitive from 5.2 to 130 micrometers, detected a minimum signal of 10(-9) watt per square centimeter per steradian referred to 100 micrometers. The origin of this signal can be instrumental, atmospheric, interplanetary, or interstellar. We can place a firm upper limit on the color temperature of a dilute cosmic background flux.