Browsing by Author "Department of Orthopaedic Surgery, IU School of Medicine"

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    Cellular senescence in aging and osteoarthritis
    (Taylor & Francis, 2016) Toh, Wei Seong; Brittberg, Mats; Farr, Jack; Foldager, Casper Bindzus; Gomoll, Andreas H.; Hui, James Hoi Po; Richardson, James B.; Roberts, Sally; Spector, Myron; Department of Orthopaedic Surgery, IU School of Medicine
    It is well accepted that age is an important contributing factor to poor cartilage repair following injury, and to the development of osteoarthritis. Cellular senescence, the loss of the ability of cells to divide, has been noted as the major factor contributing to age-related changes in cartilage homeostasis, function, and response to injury. The underlying mechanisms of cellular senescence, while not fully understood, have been associated with telomere erosion, DNA damage, oxidative stress, and inflammation. In this review, we discuss the causes and consequences of cellular senescence, and the associated biological challenges in cartilage repair. In addition, we present novel strategies for modulation of cellular senescence that may help to improve cartilage regeneration in an aging population.
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    A comparison of the shock-absorbing properties of cervical disc prosthesis bearing materials
    (Elsevier, 2011) Dahl, Michael C.; Jacobsen, Stephen; Metcalf, Newton; Sasso, Rick; Ching, Randal P.; Department of Orthopaedic Surgery, IU School of Medicine
    BACKGROUND DATA: Cervical arthroplasty offers theoretical advantages over traditional spinal fusion, including elimination of adjacent segment disease and elimination of the risk of pseudoarthrosis formation. Initial studies of cervical arthroplasty have shown promising results, however, the ideal design characteristics for disc replacement constructs have not been determined. The current study seeks to quantify the differences in the shock absorption characteristics of three commonly used materials in cervical disc arthroplasty. METHODS: Three different nucleus materials, polyurethane (PU), polyethylene (PE) and a titanium-alloy (Ti) were tested in a humidity- and temperature-controlled chamber. Ten of each nucleus type underwent three separate mechanical testing protocols to measure 1) dynamic stiffness, 2) quasi-static stiffness, 3) energy absorption, and 4) energy dissipation. The results were compared using analysis of variance. RESULTS: PU had the lowest mean dynamic stiffness (435 ± 13 N/mm, P < .0001) and highest energy absorption (19.4 ± 0.1 N/mm, P < .0001) of all three nucleus materials tested. PU was found to have significantly higher energy dissipation (viscous damping ratio 0.017 ± 0,001, P < .0001) than the PE or TI nuclei. PU had the lowest quasi-static stiffness (598 ± 23 N/mm, P < .0001) of the nucleus materials tested. A biphasic response curve was observed for all of the PU nuclei tests. CONCLUSIONS: Polyurethane absorbs and dissipates more energy and is less stiff than either polyethylene or titanium. LEVEL OF EVIDENCE: Basic Science/Biomechanical Study. CLINICAL RELEVANCE: This study characterizes important differences in biomechanical properties of materials that are currently being used for different cervical disc prostheses.
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    The demographics of developmental hip dysplasia in the Midwestern United States (Indiana)
    (Springer Berlin Heidelberg, 2015-02) Loder, Randall T.; Shafer, Cody; Department of Orthopaedic Surgery, IU School of Medicine
    Background Today’s society is much more mobile than in the past. This increased mobility has resulted in different marriage/parenting groups. We wished to study the de- mographics of developmental dysplasia of the hip (DDH) in our area and compare/contrast our findings with those in the literature and specifically look for new findings com- pared to previous studies. Methods A retrospective review of all children with DDH from 2003 through 2012 was performed. The age at first visit, gestational age, pregnancy number, gender, race, and family history of DDH was collected. Statistical sig- nificance was a p -value < 0.05. Results There were 424 children (363 girls, 61 boys). Ethnicity was White in 80.8 %, Hispanic in 13.8 %, Black in 4.0 %, and Indo-Malay and Indo-Mediterranean in 0.7 % each; 66.8 % were unilateral; 14.2 % had a positive family history. The average gestational age was 38.1 weeks; 94.4 % were full term. The child was vertex presentation in 67.6 % and breech in 32.4 %; 52.8 % were delivered vaginally and 47.2 % by Cesarean section. The child was the first-born in 48.3 %. When compared to the birth statistics of our state, there was a higher proportion of Whites and Hispanics with DDH, and a lower, but not inconsequential, proportion of Blacks ( p = 0.0018). Conclusion Mixing of gene pools and infant carrying methods (lack of swaddling or marked abduction) occurring with societal change likely explains the higher than expected proportion of DDH amongst those of His- panic ethnicity and a lower than expected, but not rare, proportion in those of African ancestry. Level of evidence Level IV—retrospective case series.
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    Do Medial Pivot Kinematics Correlate With Patient-Reported Outcomes After Total Knee Arthroplasty?
    (Elsevier, 2017) Warth, Lucian C.; Ishmael, Marshall K.; Deckard, Evan R.; Ziemba-Davis, Mary; Meneghini, R. Michael; Department of Orthopaedic Surgery, IU School of Medicine
    Background Many total knee arthroplasty (TKA) implants are designed to facilitate a medial pivot kinematic pattern. The purpose of this study was to determine whether intraoperative medial pivot kinematic patterns are associated with improved patient outcomes. Methods A retrospective review of consecutive primary TKAs was performed. Sensor-embedded tibial trials determined kinematic patterns intraoperatively. The center of rotation (COR) was identified from 0° to 90° and from 0° to terminal flexion, and designated medial-pivot or non-medial pivot based on accepted criteria. Patient-reported outcomes were measured preoperatively and at minimum one-year follow-up. Results The analysis cohort consisted of 141 TKAs. Mean age and median BMI were 63.7 years and 33.8 kg/m2, respectively. Forty-percent of TKAs demonstrated a medial pivot kinematic pattern intraoperatively. A medial pivot pattern was more common with posterior cruciate-retaining (CR) and posterior cruciate-substituting/anterior lipped (CS) implants when compared to posterior stabilized (PS) TKAs (P ≤.0150). Regardless of bearing type, minimum one-year Knee Society scores and UCLA activity level did not significantly differ based on medial vs non-medial pivot patterns (P ≥.292). For patients with posterior cruciate-sacrificing implants, there were trends for greater median improvement in Knee Society objective (46 vs 31.5 points, P =.057) and satisfaction (23 vs 14 points, P =.067) scores in medial pivot knees. Conclusion A medial pivot pattern may not significantly govern clinical success after TKA based on intraoperative kinematics and modern outcome measures. Further research is warranted to determine if a particular kinematic pattern promotes optimal clinical outcomes.
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    Do Surgical Margins Affect Local Recurrence and Survival in Extremity, Nonmetastatic, High-grade Osteosarcoma?
    (Springer, 2016-03) Bertrand, Todd E.; Cruz, Alex; Binitie, Odion; Cheong, David; Letson, G. Douglas; Department of Orthopaedic Surgery, IU School of Medicine
    BACKGROUND: Long-term survival for all patients with osteosarcoma using current aggressive adjuvant chemotherapy and surgical resection is between 60% and 70%. In patients who present with nonmetastatic, high-grade extremity osteosarcoma of bone, limb salvage surgery is favored, when appropriate, over amputation to preserve the limb, because limb salvage may lead to a superior quality of life compared with amputation. However, concern remains that in the attempt to preserve the limb, close or microscopically positive surgical margins may have an adverse effect on event-free survival. QUESTIONS/PURPOSES: (1) Does a positive or close surgical margin increase the likelihood of a local recurrence? (2) Does a positive or close surgical margin adversely affect the development of metastatic disease? (3) What is the relationship of surgical margin on overall survival? METHODS: With institutional review board approval, we retrospectively evaluated 241 patients treated at our institution between 1999 and 2011. Exclusion criteria included nonextremity locations, metastatic disease at initial presentation, low- or intermediate-grade osteosarcoma, treatment regimens that did not follow National Comprehensive Cancer Network (NCCN) guidelines, incomplete medical records, and any part of treatment performed outside of Moffitt Cancer Center or All Children's Hospital. Fifty-one patients were included in the final analysis, of whom 31 (61%) had followup data at a minimum of 2 years or whose clinical status was known but had died before 2 years of followup. Margin status was defined as (1) microscopically positive; (2) negative ≤ 1 mm; and (3) negative > 1 mm. Margin status, histologic response (tumor percent necrosis), type of osteosarcoma, type of surgery, presence of local recurrence, metastatic disease, and overall survival were recorded for each patient. The mean age was 22 years (range, 12-74 years) and the mean followup was 3 years (range, 0.1-14 years). Margin status was positive in 10% (five of 51), negative ≤ 1 mm 26% (13 of 51), and negative > 1 mm 65% (33 of 51). RESULTS: Local recurrence was noted to be 14% (seven of 51) at 3.4 years. After controlling for relevant confounding variables, the presence of a positive margin compared with a negative margin > 1 mm was the only independent predictor of local recurrence (hazard ratio [HR], 8.006; 95% confidence interval [CI], 1.314-48.781; p = 0.0241). At a mean of 3.4 years, 29% (15 of 51) of the patients developed metastatic disease with no difference with the numbers available in the probability of developing metastatic disease among the three margin groups (p = 0.614). Overall survival at 3.8 years was 75% (38 of 51). After controlling for relevant confounding variables, we found that patients with positive margins were more likely to die from disease than those with negative margins (HR, 6.26; 95% CI, 1.50-26.14; p = 0.0119); no other independent predictors of survival were identified. CONCLUSIONS: With the numbers of patients we had, we observed that patients with extremity, nonmetastatic, high-grade osteosarcoma who had positive margins showed a higher probability of local recurrence in comparison to those with negative surgical margins. Given that positive margins appear to be associated with poorer survival in patients with high-grade osteosarcoma of the extremities, surgeons should strive to achieve negative margins, but larger studies are needed to confirm these findings. LEVEL OF EVIDENCE: Level III, therapeutic study.
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    A Dual-Pivot Pattern Simulating Native Knee Kinematics Optimizes Functional Outcomes After Total Knee Arthroplasty
    (Elsevier, 2017) Meneghini, R. Michael; Deckard, Evan R.; Ishmael, Marshall K.; Ziemba-Davis, Mary; Department of Orthopaedic Surgery, IU School of Medicine
    Background Kinematics after total knee arthroplasty (TKA) have been studied for decades; however, few studies have correlated kinematic patterns to patient reported outcomes. The purpose of this study was to determine if a pattern of lateral pivot motion in early flexion and medial pivot motion in high flexion, simulating native knee kinematics, produces superior clinical outcomes. A second study objective was to determine if a specific kinematic pattern throughout the various ranges of flexion produces superior function and patient satisfaction. Methods 120 consecutive TKAs were performed using sensor embedded tibial trials to record intraoperative knee kinematics through the full range of motion. Established criteria were used to identify lateral (L) or medial (M) pivot kinematic patterns based on the center of rotation within three flexion zones -- 0 to 45° (early flexion), 45 to 90° (mid flexion) and 90° to terminal flexion (late flexion). Knee Society Scores, pain scores, and patient satisfaction were analysed in relationship to kinematic patterns. Results Knee Society function scores were significantly higher in TKAs with early lateral pivot/late medial pivot intraoperative kinematics compared to all other kinematic patterns (p = 0.018) at minimum one-year follow-up. There was a greater decrease in the proportion of patients with early lateral/late medial pivot kinematics who reported that their knee never feels normal (p = 0.011). Higher mean function scores at minimum one-year follow-up (p < 0.001) and improvement from preoperative baseline (p = 0.008) were observed in patients with the most ideal “LLM” kinematic pattern (lateral pivot 0 to 45o and 45 to 90o; medial pivot beyond 90o) compared to those with the least ideal “MLL” kinematic pattern. All patients with the optimal “LLM” kinematic pattern compared to none of those with the “MLL” kinematic pattern reported that they were very satisfied with their TKA (p = 0.003). Conclusion Patients who exhibited an early flexion lateral pivot kinematic pattern accompanied by medial pivot motion in later flexion, as measured intraoperatively, reported higher functional outcome scores along with higher overall patient satisfaction. Replicating the dual-pivot kinematic pattern observed in native knees may improve function and satisfaction after TKA. Further study is warranted to explore a correlation with in-vivo kinematic patterns.
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    Embedded piezoelectrics for sensing and energy harvesting in total knee replacement units
    (SPIE, 2015-04) Wilson, Brooke E.; Meneghini, R. Michael; Anton, Steven R.; Department of Orthopaedic Surgery, IU School of Medicine
    The knee replacement is the second most common orthopedic surgical intervention in the United States, but currently only 1 in 5 knee replacement patients are satisfied with their level of pain reduction one year after surgery. It is imperative to make the process of knee replacement surgery more objective by developing a data driven approach to ligamentous balance, which increases implant life. In this work, piezoelectric materials are considered for both sensing and energy harvesting applications in total knee replacement implants. This work aims to embed piezoelectric material in the polyethylene bearing of a knee replacement unit to act as self-powered sensors that will aid in the alignment and balance of the knee replacement by providing intraoperative feedback to the surgeon. Postoperatively, the piezoelectric sensors can monitor the structural health of the implant in order to perceive potential problems before they become bothersome to the patient. Specifically, this work will present on the use of finite element modeling coupled with uniaxial compression testing to prove that piezoelectric stacks can be utilized to harvest sufficient energy to power sensors needed for this application. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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    Evaluation of Joint Space Width and Narrowing After Isolated Partial Medial Meniscectomy for Degenerative Medial Meniscus Tears
    (SAGE Publications, 2013-10) Shelbourne, K. Donald; Barnes, Adam F.; Urch, Scott E.; Gray, Tinker; Department of Orthopaedic Surgery, IU School of Medicine
    BACKGROUND: Few studies have evaluated the effect of existing articular cartilage damage and sex on joint space measurements after isolated degenerative medial meniscus tears. PURPOSE: To determine what factors affected joint space width and narrowing in patients after removal of isolated degenerative medial meniscus tears. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 62 patients (15 women and 47 men) with all ligaments intact, no previous surgery to either knee, and an isolated degenerative medial meniscus tear removed in 1 knee were examined. The mean age at examination was 58.2 years at a mean follow-up of 9.4 years (range, 4-20 years). Subjective results were obtained with the International Knee Documentation Committee (IKDC) knee survey. Radiographs were taken using 45° weightbearing posteroanterior views. Midpoint and perceived minimum joint space width of the medial and lateral compartments of both knees were measured to the nearest 0.1 mm by 2 observers at different times, and they were blinded as to the previous measurements (Pearson intra- and interclass correlations, >0.93). Joint space narrowing was found by calculating the difference in joint space width between knees. Percentage of normal joint space loss was calculated by dividing joint space narrowing by the joint space width in the contralateral knee. Other factors considered were patient sex and Outerbridge grading of articular cartilage. RESULTS: Women had a mean 1.5 mm less normal joint space width than men in the involved and noninvolved knees (P < .01). Mean joint space narrowing was 0.7 mm for both measurements. The mean ± standard deviation narrowing was 0.4 ± 1.2 mm for patients with grade 0-2 damage and 1.1 ± 1.3 for patients with grade 3-4 damage (P = .04). Five women (33%) and 3 men (6%) had narrowing of >50% of the normal joint space as measured in the noninjured knee (P = .016). The mean IKDC total score was 66.1 points for women, which was statistically significantly lower than the mean of 82.7 points for men (P < .01). CONCLUSION: Patients undergoing partial medial meniscectomy have greater joint space narrowing and lower subjective scores after surgery if they also have existing Outerbridge grade 3-4 damage. Women have less normal joint space than men, and more women than men experience >50% joint space narrowing after surgery.
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    Gartland type III supracondylar humerus fractures: outcome and complications as related to operative timing and pin configuration
    (Springer Berlin Heidelberg, 2014-12) Abbott, Matthew D.; Buchler, Lucas; Loder, Randall T.; Caltoum, Christine B.; Department of Orthopaedic Surgery, IU School of Medicine
    Purpose Supracondylar fractures of the humerus are the most common fracture of theelbow in children. The pur- pose of this study was to evaluate, in terms of outcomes andcomplications, Gartland type III pediatric supracondy- lar humerus fractures treated at apediatric level-one trauma center over a 7-year period, specifically addressing the- impact of time to surgery on the incidence of complications and conversion to openreduction. Methods We retrospectively reviewed 297 pediatric patients that sustained a closedGartland type III supra- condylar humerus fracture treated between December 2004 andDecember 2011. The time to the operating room was calculated from the medical recordsfor each patient. The outcome measures evaluated were operative time, conver- sion toopen procedure, and perioperative and postoperative complications. Results In our study, there were 30 complications in 25 children (8.4%). Conversion to open reduction occurred in 28 children (9.4%). The time from the emergency depart- ment to the operating room was not significantly correlated with increased complications, increased operative time, or conversion to open reduction ( p > 0.05). Crossed pinning resulted in an increased risk of overall complications [odds ratio (OR) = 2.6] and iatrogenic nerve injuries (OR = 9.3). Complications also occurred more commonly in boys (OR = 3.3) and in older patients ( p = 0.0069) Conclusions We found no significant correlation between the time to surgery andcomplications, operative time, or need for open reduction. These findings support thetrend of treating Gartland type III supracondylar humerus fractures in a less urgentmanner. In addition, our study supports the concept that cross pinning leads to morecomplications than lateral pinning, including an 8-fold increase in iatrogenic nerveinjury
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    Generation of the first Autosomal Dominant Osteopetrosis Type II (ADO2) disease models
    (Elsevier B.V., 2014-02) Alam, Imranul; Gray, Amie K.; Chu, Kang; Ichikawa, Shoji; Mohammad, Khalid S.; Capannolo, Marta; Capulli, Mattia; Maurizi, Antonio; Muraca, Maurizio; Teti, Anna; Econs, Michael J.; Del Fattore, Andrea; Department of Orthopaedic Surgery, IU School of Medicine
    Autosomal Dominant Osteopetrosis Type II (ADO2) is a heritable osteosclerotic disorder dependent on osteoclast impairment. In most patients it results from heterozygous missense mutations in the chloride channel 7 (CLCN7) gene, encoding for a 2Cl−/1H+ antiporter. By a knock-in strategy inserting a missense mutation in the Clcn7 gene, our two research groups independently generated mouse models of ADO2 on different genetic backgrounds carrying the homolog of the most frequent heterozygous mutation (p.G213R) in the Clcn7 gene found in humans. Our results demonstrate that the heterozygous model holds true presenting with higher bone mass, increased numbers of poorly resorbing osteoclasts and a lethal phenotype in the homozygous state. Considerable variability is observed in the heterozygous mice according with the mouse background, suggesting that modifier genes could influence the penetrance of the disease gene.