Department of Orthopaedic Surgery Works

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Improved Tissue Repair in Articular Cartilage Defects in Vivo by rAAV-Mediated Overexpression of Human Fibroblast Growth Factor 2
(Elsevier, 2005-08-01) Cucchiarini, Magali; Madry, Henning; Ma, Chunyan; Thurn, Tanja; Zurakowski, David; Menger, Michael D.; Kohn, Dieter; Trippel, Stephen B.; Terwilliger, Ernest F.; Orthopaedic Surgery, School of Medicine
Therapeutic gene transfer into articular cartilage is a potential means to stimulate reparative activities in tissue lesions. We previously demonstrated that direct application of recombinant adeno-associated virus (rAAV) vectors to articular chondrocytes in their native matrix in situ as well as sites of tissue damage allowed for efficient and sustained reporter gene expression. Here we test the hypothesis that rAAV-mediated overexpression of fibroblast growth factor 2 (FGF-2), one candidate for enhancing the repair of cartilage lesions, would lead to the production of a biologically active factor that would facilitate the healing of articular cartilage defects. In vitro, FGF-2 production from an rAAV-delivered transgene was sufficient to stimulate chondrocyte proliferation over a prolonged period of time. In vivo, application of the therapeutic vector significantly improved the overall repair, filling, architecture, and cell morphology of osteochondral defects in rabbit knee joints. Differences in matrix synthesis were also observed, although not to the point of statistical significance. This process may further benefit from cosupplementation with other factors. These results provide a basis for rAAV application to sites of articular cartilage damage to deliver agents that promote tissue repair.
Lumbar extraforaminal decompression: A technical note and retrospective study looking at potential complications as an outpatient procedure
(Elsevier, 2011) Miller, Justin W.; Sasso, Rick C.; Department of Orthopaedic Surgery, IU School of Medicine
BACKGROUND: Lumbar disc herniation and stenosis that results in compression of a nerve root lateral to the foramen is defined as extraforaminal. In recent years the recognition of such pathology has increased with technology and greater awareness. Various approaches and techniques have been developed for extraforaminal decompression in the lumbar region. The purpose of this study was two fold: 1) Determine the safety of treating patients operatively via a paramedian muscle splitting approach on an outpatient basis, and 2) Highlight the technical aspects of the approach to the extraforaminal region. METHODS: One hundred consecutive extraforaminal decompressions were performed from 1992 to 2007 by a single surgeon. A retrospective review was performed consisting of chart reviews. Summary statistics and the Pierson Chi-square test were used to analyze the data. The primary outcome measure was the need for hospital admission or readmission following surgical decompression. RESULTS: Seven of 100 patients (7%) were required to remain in the hospital for twenty-three hour observation due to Medicare requirements. Five (5%) of the patients originally scheduled for an outpatient procedure were converted to inpatient status due to postoperative pain. All were released within 2 days (average 1.25 days). Only one (1%) patient was readmitted for urinary retention that resolved without incident. There was no significant difference (P = 0.137) in complication rate between our control and those that underwent extraforaminal decompression. CONCLUSIONS: Extraforaminal lumbar decompression as an outpatient procedure can be done safely without the need for hospital admission.
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.
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.
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.
High Survivorship With a Titanium-encased Alumina Ceramic Bearing for Total Hip Arthroplasty
(Springer US, 2014-02) D’Antonio, James A.; Capello, William N.; Naughton, Marybeth; Department of Orthopaedic Surgery, IU School of Medicine
Background Although ceramic-on-ceramic bearings for total hip arthroplasty (THA) show promising results in terms of bearing-surface wear, fracture of the bearing, insertional chips, and squeaking remain a concern. Questions/purposes Our primary objective of this report was to determine overall survivorship of a titanium- encased ceramic-on-ceramic bearing couple. Our secondary objectives were to evaluate for ceramic fracture, insertional chips, osteolysis, and device squeaking. Methods Six surgeons at six institutions implanted 194 patients (209 hips) with an average age of 52 years with cementless hips and alumina ceramic bearings. One hun- dred thirty-seven patients (146 hips) have 10-year followup (70%). We determined Kaplan-Meier survivorship of the bearing surface and implant system and collected radio- graphic and clinical data to evaluate for osteolysis and squeaking. Results Survivorship using revision for any reason as the end point was 97% at 10 years and survivorship end point bearing surface failure or aseptic loosening of 99%. There was one ceramic insert fracture (0.5%), there were no insertional chips, there was no visible osteolysis on AP and lateral radiographs, and there was a 1% patient- self-reported incidence of squeaking at the last clinical followup. Six hips underwent revision (3.7%). Conclusions Ceramic bearings for THA with a titanium- encased insert have high survivorship at 10 years followup and a fracture risk of 0.5%. We found at last followup on routine radiographs no evidence of osteolysis, and no patient has been revised for squeaking or has reported dissatisfaction with the clinical result because of noise. Level of Evidence Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
Periprosthetic Fractures Around a Cementless Hydroxyapatite-coated Implant: A New Fracture Pattern Is Described
(Springer US, 2014-02) Capello, William N.; D’Antonio, James A.; Naughton, Marybeth; Department of Orthopaedic Surgery, IU School of Medicine
Background Periprosthetic fractures can occur both intraoperatively and postoperatively with implantation of cementless tapered stems. Questions/purposes In a large cohort of patients receiving cementless, proximally hydroxyapatite-coated femoral implants, we answered the following questions: What was the incidence of intraoperative and postoperative fractures associated with the implant? What were the fracture patterns as classified by the Vancouver classification system? Did the Vancouver classification represent the fracture patterns found? How were the fractures treated and what were the treatment outcomes; that is, how many fractures healed and did the stems osseointegrate? Methods We evaluated 1039 hips (932 patients) from three prospective studies. The hips were divided into three groups: no fractures, intraoperative fractures, and postoperative fractures. Demographic differences among the groups were noted. Postoperative fractures were classified using the Vancouver classification system. We judged stem stability using Engh’s criteria and fracture union was determined by the treating surgeon and confirmed by the authors. Results We identified 58 periprosthetic fractures in the 1039 hips (5.6%): 38 intraoperative (3.7%) and 20 postoperative (1.9%). Eleven of the postoperative fractures were classifiable by the original Vancouver classification system and nine were of the newly described “clamshell” variety, not classifiable by this system. No intraoperative fractures extended below the lesser trochanter. Twenty-five of these fractures were treated with a single cable or cerclage wire. The remaining received no specific treatment. Of the 20 postoperative fractures, five were treated nonoperatively. All stems osseointegrated. Conclusions Both intraoperative and postoperative fractures can be managed with success when the stem is stabilized or found to be osseointegrated. An adjustment to the Vancouver classification is suggested to include the clamshell fracture, which has not been previously described. Level of Evidence Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
Multiscale analysis of morphology and mechanics in tail tendon from the ZDSD rat model of type 2 diabetes
(Elsevier, 2014-02-07) Gonzalez, Armando Diaz; Gallant, Maxime A.; Burr, David B.; Wallace, Joseph M.; Department of Orthopaedic Surgery, IU School of Medicine
Type 2 diabetes (T2D) impacts multiple organ systems including the circulatory, renal, nervous and musculoskeletal systems. In collagen-based tissues, one mechanism that may be responsible for detrimental mechanical impacts of T2D is the formation of advanced glycation end products (AGEs) leading to increased collagen stiffness and decreased toughness, resulting in brittle tissue behavior. The purpose of this study was to investigate tendon mechanical properties from normal and diabetic rats at two distinct length scales, testing the hypothesis that increased stiffness and strength and decreased toughness at the fiber level would be associated with alterations in nanoscale morphology and mechanics. Individual fascicles from female Zucker diabetic Sprague-Dawley (ZDSD) rats had no differences in fascicle-level mechanical properties but had increased material-level strength and stiffness versus control rats (CD). At the nanoscale, collagen fibril D-spacing was shifted towards higher spacing values in diabetic ZDSD fibrils. The distribution of nanoscale modulus values was also shifted to higher values. Material-level strength and stiffness from whole fiber tests were increased in ZDSD tails. Correlations between nanoscale and microscale properties indicate a direct positive relationship between the two length scales, most notably in the relationship between nanoscale and microscale modulus. These findings indicate that diabetes-induced changes in material strength and modulus were driven by alterations at the nanoscale.
Arthroscopic dorsal wrist ganglion excision with color-aided visualization of the stalk: minimum 1-year follow-up
(Springer, Part of Springer Science+Business Media, 2014-06) Ahsan, Zahab S.; Yao, Jeffrey; Department of Orthopaedic Surgery, School of Medicine
Background Dorsal wrist ganglia (DWG) are a common, benign soft-tissue mass of the wrist. Excision of DWG is a common procedure performed by hand surgeons and may be performed using either open or arthroscopic techniques. This study aims to evaluate the frequency of stalk visualization with intralesional injection of inert dye in the course of arthroscopic excision along with incidence of recurrence with a minimum of 1-year follow-up. Methods Upon IRB approval, a retrospective chart review was performed identifying 27 patients who had consecutively undergone arthroscopic excision of a DWG with the color-aided technique at our institution with a minimum follow-up duration of 12 months. Intraoperative findings were reviewed. Patients were contacted to investigate for incidence of recurrence. Results Of the 27-patient cohort, the ganglion stalk was identified in 100 % of the color-aided arthroscopic DWG excisions. Ganglion recurrence was identified in one patient, an incidence of 3.7 %. Conclusions The color-aided technique for arthroscopic DWG visualization was found to be a safe and valuable tool for surgeons performing arthroscopic DWG resection. The intraarticular ganglion stalk was identified in 100 % of cases and patients responded well with a low incidence of recurrence.
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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