Thomas H. McCoy

Stem Fixation in Revision Total Knee Arthroplasty: A Comparative Analysis

Methods of stem fixation are a controversial aspect of revision TKA. We sought to determine which technique was superior by reviewing 475 revision TKAs done between 1986 and 2000. Of these 475 revisions, 286 major component revisions were done using 484 extended stems for fixation. Patients who died, patients who had less than 2 years followupm, or patients who had diaphyseal engaging stems were excluded from the study. The final data set included 113 revision TKAs with 202 metaphyseal engaging stems. Of the 202 stems, 107 were cemented whereas 95 were press-fit metaphyseal engaging stems. One hundred one of these were femoral stems and 101 were tibial stems. Using a modified Knee Society radiographic scoring system, 100 (93%) of the 107 implants with cemented stems were considered stable, seven (7%) were categorized as possibly loose requiring close followup, and none were loose. Of the 95 implants placed with cementless stems, only 67 (71%) were categorized as stable. Eighteen (19%) were possibly loose requiring close followup and 10 (10%) were loose (two tibial and eight femoral implants). We currently would urge caution in using cementless metaphyseal engaging stems for fixation in revision TKA.

Polyethylene exchange only for prosthetic knee instability.

From 1987 to 1996, 47 revision total knee arthroplasties were done for tibiofemoral instability. Sixteen of these patients had polyethylene exchange only to treat their instability. Fourteen of these patients were available for review. The mean followup was 56 months. The mean Hospital for Special Surgery Knee Score increased from 50 points preoperatively to 73 points at the most recent followup. Clinically, stable knees were produced in 71% of patients (10 of 14). The results of the current study suggest that polyethylene exchange can be an effective, low morbidity procedure to treat certain types of prosthetic knee instability. A failure rate of 29% (four of 14) however, is concerning. Alternative methods of stabilization should be used, if there is any question concerning the stability of a construct where a polyethylene exchange only is used.

Does Humeral Lengthening With a Monolateral Frame Improve Function

BackgroundHumeral lengthening by distraction osteogenesis historically has relied on bulky circular external fixators. Advances in fixator technology have allowed for the use of monolateral frames. However, it is unclear whether and to what degree function is improved after humeral lengthening.Questions/PurposesWe asked: (1) Does humeral lengthening performed with monolateral fixators improve function? (2) Does monolateral external fixation produce comparable restoration of length and complication rate when compared with historical results, using circular external fixation for humeral lengthening?MethodsWe retrospectively reviewed 11 patients who underwent 15 humeral lengthenings with monolateral external fixation. Clinical and radiographic data were collected, including preoperative and postoperative DASH scores as a metric of functional status. The minimum postremoval followup was 14 months (average, 38 months; range, 14–84 months).ResultsFifteen humeri were lengthened an average of 7 cm (range, 4–9 cm), for a mean lengthening of 41% (range, 23%–52%). Lengthening required an average of 7 months (range, 5–8 months) of fixation, resulting in an external fixation index of 32 days/cm (range, 23–45 days/cm). The major complication rate (three of 15) and postoperative ROM (unchanged at the elbow and improved in seven of 15 shoulders) were comparable to those in previous studies using circular frames. In nine of 15 humeri for which DASH scores were available, the mean preoperative score improved from 14 to 9 after 1 year. The monolateral frame allowed the patient to keep their arm by the side without abducting the shoulder and without impinging the device into the chest wall.ConclusionsHumeral lengthening with monolateral external fixation is well tolerated by patients and an effective means of improving patient function with a complication rate similar to that for traditional circular frames.Level of EvidenceLevel III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Circular External Fixator-Assisted Ankle Arthrodesis Following Failed Total Ankle Arthroplasty

Background: Failed total ankle arthroplasty (TAA) often results in significant bone loss and requires salvage arthrodesis. This study quantified the bone loss following failed TAA and reports the outcome of seven arthrodesis reconstructions using the Ilizarov method. Methods: A retrospective review of ankle fusions was performed for failed TAA to collect the mode of implant failure, presenting limb length discrepancy (LLD), total bone defect, postarthrodesis LLD, and treatment type (shoe lift versus distraction osteogenesis) and amount (shoe lift or lengthening). Results: Four mechanical failures and three infections were found. Four of seven cases had prior revision TAAs. Four of seven patients were treated with tibiotalar arthrodesis; three of the seven patients required talar resection and tibiocalcaneal arthrodesis. The mean presenting LLD was 2.2 (range, 1.2 to 3.5) cm. The mean time in frame was 197 (range, 146 to 229) days. With a mean postexplantation total bone defect of 5.1 (range, 3.7 to 8.5) cm, four of seven patients elected tibial lengthening following fusion [mean lengthening 4.6 (range, 2.5 to 8.0) cm; external fixation index (EFI) 42.6 (range, 16.5 to 55.6) days/cm)]. Three of seven patients were treated with a shoe lift [mean lift height 2.9 (range 2.5 to 3.2) cm]. There was no failure of fixation, refracture, or infection. All patients had a stable plantigrade foot and walked with minimal limp. Association for the Study and Application of the Method of Ilizarov (ASAMI) functional scores were six good and one fair. ASAMI bone scores were four excellent and three good. Conclusions: Ankle arthrodesis following failed TAA results in large LLDs secondary to bone loss during implant failure and subsequent explantation. External fixation can produce an excellent fusion rate in complex, possibly infected, failed TAAs. Limb length equalization (by either distraction osteogenesis or shoe lift) provides a means of obtaining good functional outcomes following failed TAA. Level of Evidence: IV, Retrospective Case Series

Risk and Resilience Factors Associated with Resident Burnout

ObjectiveWe investigated hypothesized risk and resilience factors and their association with burnout in first year medicine and psychiatry residents at an urban teaching hospital in order to help guide the development of interventions targeted at reducing burnout.MethodsWe administered the Maslach Burnout Inventory (MBI), Perceived Stress Scale-10, Functional Assessment of Chronic Illness Therapy–Fatigue Scale, Penn State Worry Questionnaire, Patient Health Questionnaire-9 (depression symptoms), Revised Life Orientation Test (optimism), Self-Efficacy Questionnaire, Cognitive and Affective Mindfulness Scale, Interpersonal Reactivity Index Perspective-Taking Scale (empathy), and Measure of Current Status-Part A to first year medicine and psychiatry residents prior to initiation of clinical rotations in June.ResultsThe response rate was 91 % (68 of 75 residents). Nineteen respondents (28 %) met criteria for burnout as measured by the MBI. Residents with burnout scored higher on self-report measures assessing perceived stress (Cohen’s d = 0.97; p = 0.004), fatigue (d = 0.79; p = 0.018), worry (d = 0.88; p = 0.0009), and depression symptoms (d = 0.84; p = 0.035) and scored lower on questionnaires assessing mindfulness (d = −0.63; p = 0.029) and coping ability (d = −0.79; p = 0.003).ConclusionsIn a cross-sectional assessment using self-report measures, we found that nearly a third of first year residents prior to starting their internships experience burnout. They exhibit lower levels of mindfulness and coping skills and higher levels of depression symptoms, fatigue, worry, and stress. These preliminary findings should encourage programs to initiate and study curricula that combine mindfulness and self-awareness coping strategies to enhance or protect against burnout as well as cognitive behavioral coaching strategies to offset symptoms of burnout when present.

Predicting early psychiatric readmission with natural language processing of narrative discharge summaries.

The ability to predict psychiatric readmission would facilitate the development of interventions to reduce this risk, a major driver of psychiatric health-care costs. The symptoms or characteristics of illness course necessary to develop reliable predictors are not available in coded billing data, but may be present in narrative electronic health record (EHR) discharge summaries. We identified a cohort of individuals admitted to a psychiatric inpatient unit between 1994 and 2012 with a principal diagnosis of major depressive disorder, and extracted inpatient psychiatric discharge narrative notes. Using these data, we trained a 75-topic Latent Dirichlet Allocation (LDA) model, a form of natural language processing, which identifies groups of words associated with topics discussed in a document collection. The cohort was randomly split to derive a training (70%) and testing (30%) data set, and we trained separate support vector machine models for baseline clinical features alone, baseline features plus common individual words and the above plus topics identified from the 75-topic LDA model. Of 4687 patients with inpatient discharge summaries, 470 were readmitted within 30 days. The 75-topic LDA model included topics linked to psychiatric symptoms (suicide, severe depression, anxiety, trauma, eating/weight and panic) and major depressive disorder comorbidities (infection, postpartum, brain tumor, diarrhea and pulmonary disease). By including LDA topics, prediction of readmission, as measured by area under receiver-operating characteristic curves in the testing data set, was improved from baseline (area under the curve 0.618) to baseline+1000 words (0.682) to baseline+75 topics (0.784). Inclusion of topics derived from narrative notes allows more accurate discrimination of individuals at high risk for psychiatric readmission in this cohort. Topic modeling and related approaches offer the potential to improve prediction using EHRs, if generalizability can be established in other clinical cohorts.

Bone tumor reconstruction with the Ilizarov method

Patients with musculoskeletal tumors can face large bone deficiency, deformity, and nonunion. Distraction osteogenesis via the Ilizarov method may be useful for reconstruction of these deficiencies allowing limb preservation and optimizing function.

Stratifying Risk for Renal Insufficiency Among Lithium-Treated Patients: An Electronic Health Record Study.

Although lithium preparations remain first-line treatment for bipolar disorder, risk for development of renal insufficiency may discourage their use. Estimating such risk could allow more informed decisions and facilitate development of prevention strategies. We utilized electronic health records from a large New England health-care system between 2006 and 2013 to identify patients aged 18 years or older with a lithium prescription. Renal insufficiency was identified using the presence of renal failure by ICD9 code or laboratory-confirmed glomerular filtration rate below 60 ml/min. Logistic regression was used to build a predictive model in a random two-thirds of the cohort, which was tested in the remaining one-third. Risks associated with aspects of pharmacotherapy were also examined in the full cohort. We identified 1445 adult lithium-treated patients with renal insufficiency, matched by risk set sampling 1 : 3 with 4306 lithium-exposed patients without renal insufficiency. In regression models, features associated with risk included older age, female sex, history of smoking, history of hypertension, overall burden of medical comorbidity, and diagnosis of schizophrenia or schizoaffective disorder (p<0.01 for all contrasts). The model yielded an area under the ROC curve exceeding 0.81 in an independent testing set, with 74% of renal insufficiency cases among the top two risk quintiles. Use of lithium more than once daily, lithium levels greater than 0.6 mEq/l, and use of first-generation antipsychotics were independently associated with risk. These results suggest the possibility of stratifying risk for renal failure among lithium-treated patients. Once-daily lithium dosing and maintaining lower lithium levels where possible may represent strategies for reducing risk.

Stratification of risk for hospital admissions for injury related to fall: cohort study

Objective To determine whether the ability to stratify an individual patient’s hazard for falling could facilitate development of focused interventions aimed at reducing these adverse outcomes. Design Clinical and sociodemographic data from electronic health records were utilized to derive multiple logistic regression models of hospital readmissions for injuries related to falls. Drugs used at admission were summarized based on reported adverse effect frequencies in published drug labeling. Setting Two large academic medical centers in New England, United States. Participants The model was developed with 25 924 individuals age ≥40 with an initial hospital discharge. The resulting model was then tested in an independent set of 13 032 inpatients drawn from the same hospital and 36 588 individuals discharged from a second large hospital during the same period. Main outcome measure Hospital readmissions for injury related to falls. Results Among 25 924 discharged individuals, 680 (2.6%) were evaluated in the emergency department or admitted to hospital for a fall within 30 days of discharge, 1635 (6.3%) within 180 days of discharge, 2360 (9.1%) within one year, and 3465 (13.4%) within two years. Older age, female sex, white or African-American race, public insurance, greater number of drugs taken on discharge, and score for burden of adverse effects were each independently associated with hazard for fall. For drug burden, presence of a drug with a frequency of adverse effects related to fall of 10% was associated with 3.5% increase in odds of falling over the next two years (odds ratio 1.04, 95% confidence interval 1.02 to 1.05). In an independent testing set, the area under the receiver operating characteristics curve was 0.65 for a fall within two years based on cross sectional data and 0.72 with the addition of prior utilization data including age adjusted Charlson comorbidity index. Portability was promising, with area under the curve of 0.71 for the longitudinal model in a second hospital system. Conclusions It is potentially useful to stratify risk of falls based on clinical features available as artifacts of routine clinical care. A web based tool can be used to calculate and visualize risk associated with drug treatment to facilitate further investigation and application.

A Clinical Perspective on the Relevance of Research Domain Criteria in Electronic Health Records

OBJECTIVE The limitations of the DSM nosology for capturing dimensionality and overlap in psychiatric syndromes, and its poor correspondence to underlying neurobiology, have been well established. The Research Domain Criteria (RDoC), a proposed dimensional model of psychopathology, may offer new insights into psychiatric illness. For psychiatric clinicians, however, because tools for capturing these domains in clinical practice have not yet been established, the relevance and means of transition from the categorical system of DSM-5 to the dimensional models of RDoC remains unclear. The authors explored a method of extracting these dimensions from existing electronic health record (EHR) notes. METHOD The authors used information retrieval and natural language processing methods to extract estimates of the RDoC dimensions in the EHRs of a large health system. They parsed and scored EHR documentation for 2,484 admissions covering 2,010 patients admitted to a psychiatric inpatient unit between 2011 and 2013. These domain scores were compared with DSM-IV-based ICD-9 codes to assess face validity. As a measure of predictive validity, these scores were examined for association with two outcomes: length of hospital stay and time to all-cause hospital readmission. Together, these analyses were intended to address the extent to which RDoC symptom domains might capture clinical features already available in narrative notes but not reflected in DSM diagnoses. RESULTS In mixed-effects models, loadings for the RDoC cognitive and arousal domains were associated with length of hospital stay, while the negative valence and social domains were associated with hazard of all-cause hospital readmission. CONCLUSIONS These findings show that a computationally derived tool based on RDoC workgroup reports identifies symptom distributions in clinician notes beyond those captured by ICD-9 codes, and these domains have significant predictive validity. More generally, they point to the possibility that clinicians already document RDoC-relevant symptoms, albeit not in a quantified form.