Diego Villacis
University of Southern California
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Journal of Bone and Joint Surgery, American Volume | 2011
Hany El-Rashidy; Diego Villacis; Imran M. Omar; Armen S. Kelikian
BACKGROUND Osteochondral lesions of the talar dome can cause substantial functional impairment and present a difficult treatment dilemma. Interest has recently focused on fresh osteochondral allografts as a promising treatment alternative. The purpose of this study was to evaluate the clinical outcome of osteochondral lesions of the talus treated with a fresh osteochondral allograft. METHODS We performed a transfer of fresh osteochondral allograft in forty-two patients with a symptomatic, refractory osteochondral lesion of the talus. Complete postoperative follow-up was achieved for thirty-eight patients with an average age of 44.2 years. Clinical evaluation was performed with use of the American Orthopaedic Foot & Ankle Society ankle-hindfoot score and a visual analog pain scale. All scores were obtained from either a retrospective chart review or a direct patient interview. All patients were also asked about their subjective satisfaction with the procedure. Magnetic resonance images were acquired for fifteen patients, to assess graft incorporation, subsidence, articular cartilage congruity, osteoarthritis, and stability with use of the De Smet criteria. RESULTS The average duration of follow-up after osteochondral allograft transplantation was 37.7 months. Graft failure occurred in four patients. With the inclusion of scores before revision for those with graft failure, the mean visual analog pain scale score improved from 8.2 to 3.3 points, and the mean American Orthopaedic Foot & Ankle Society ankle-hindfoot score improved from 52 to 79 points. Patient satisfaction with the outcome was rated as excellent, very good, or good by twenty-eight of the thirty-eight patients and as fair or poor by ten patients. Of the fifteen magnetic resonance imaging scans, most showed minimal graft subsidence, reasonable graft stability, and persistent articular congruence. CONCLUSIONS In our experience, transplantation of fresh osteochondral allograft is a viable and effective method for the treatment of osteochondral lesions of the talus as evidenced by improvements in pain and function.
Journal of Bone and Joint Surgery, American Volume | 2014
Diego Villacis; Jarrad Merriman; Raj Yalamanchili; Reza Omid; John M. Itamura; George F. Rick Hatch
BACKGROUND Infection after shoulder arthroplasty can be a devastating complication, and subacute and chronic low-grade infections have proven difficult to diagnose. Serum marker analyses commonly used to diagnose periprosthetic infection are often inconclusive. The purpose of this study was to evaluate the effectiveness of serum interleukin-6 (IL-6) as a marker of periprosthetic shoulder infection. METHODS A prospective cohort study of thirty-four patients who had previously undergone shoulder arthroplasty and required revision surgery was conducted. The serum levels of IL-6 and C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and the white blood-cell count (WBC) were measured. The definitive diagnosis of an infection was determined by growth of bacteria on culture of intraoperative specimens. Two-sample Wilcoxon rank-sum (Mann-Whitney) tests were used to determine the presence of a significant difference in the ESR and WBC between patients with and those without infection, while the Fisher exact test was used to assess differences in IL-6 and CRP levels between those groups. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each marker were also calculated. RESULTS There was no significant difference in the IL-6 level, WBC, ESR, or CRP level between patients with and those without infection. With a normal serum IL-6 level defined as <10 pg/mL, this test had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 0.14, 0.95, 0.67, 0.61, and 0.62, respectively. CONCLUSIONS IL-6 analysis may have utility as a confirmatory test but is not an effective screening tool for periprosthetic shoulder infection. This finding is in contrast to the observation, in previous studies, that IL-6 is more sensitive than traditional serum markers for periprosthetic infection.
Orthopedics | 2013
Marty E Reed; Diego Villacis; George F. Rick Hatch; Wendy S. Burke; Patrick M. Colletti; Steven J. Narvy; Raffy Mirzayan; C. Thomas Vangsness
The purpose of this study was to evaluate the ability of 3.0-Tesla magnetic resonance imaging (MRI) to accurately assess knee articular cartilage lesions. Sixteen patients who had knee 3.0-T MRI and underwent knee arthroscopy for partial meniscectomy were included. Three fellowship-trained sports medicine orthopedic surgeons reviewed all images. Articular lesions on MRI were graded from I to IV and compared with arthroscopic grading using the Outerbridge and the International Cartilage Repair Society (ICRS) classifications. The articular surface was divided into 6 regions. Based on MRI findings, of the 288 articular surface evaluations, 113 (39%) surface evaluations were classified as disease-positive (grade 2 to 4). Kappa interrater reliability scores for MRI evaluation, Outerbridge classification, and ICRS classification were 0.13, 0.54, and 0.41, respectively. Using the Outerbridge classification as a reference standard, the sensitivity, specificity, and accuracy were 57%, 71%, and 63%, respectively. Using the ICRS classification, sensitivity, specificity, and accuracy were 59%, 71%, and 69%, respectively. When isolating the articular grading to the senior author on MRI evaluation vs Outerbridge classification, the sensitivity, specificity, and accuracy were 54%, 92%, and 75%, respectively. Based on the current findings, 3.0-T MRI is as an invaluable noninvasive tool with good diagnostic value for assessing articular cartilage lesions of the knee, although it may not be as sensitive and accurate as previously reported.
Arthroscopy techniques | 2013
Diego Villacis; Jarrad Merriman; Karlton Wong; George F. Rick Hatch
Latissimus dorsi transfer is a well-established method for the treatment of posterosuperior massive irreparable rotator cuff tears. We propose using an arthroscopically assisted technique that avoids insult to the deltoid. With the patient in the lateral decubitus position, an L-shaped incision is made along the anterior belly of the latissimus muscle and then along the posterior axillary line. The latissimus and teres major are identified and separated. The tendon insertion of the latissimus is isolated, and a FiberWire traction suture (Arthrex, Naples, FL) is placed, facilitating dissection of the muscle to the thoracodorsal neurovascular pedicle and subsequent mobilization. The interval deep to the deltoid and superficial to the teres minor is developed into a subdeltoid tunnel for arthroscopic tendon transfer. The latissimus tendon is then transferred and stabilized arthroscopically to the lateral aspect of the infraspinatus and supraspinatus footprints by multiple suture anchors.
Sports Health: A Multidisciplinary Approach | 2014
Diego Villacis; Anthony Yi; Ryan Jahn; Curtis J. Kephart; Timothy P. Charlton; Seth C. Gamradt; Russ Romano; James E. Tibone; George F. Rick Hatch
Background: Up to 1 billion people have insufficient or deficient vitamin D levels. Despite the well-documented, widespread prevalence of low vitamin D levels and the importance of vitamin D for athletes, there is a paucity of research investigating the prevalence of vitamin D deficiency in athletes. Hypothesis: We investigated the prevalence of abnormal vitamin D levels in National Collegiate Athletic Association (NCAA) Division I college athletes at a single institution. We hypothesized that vitamin D insufficiency is prevalent among our cohort. Study Design: Cohort study. Level of Evidence: Level 1. Methods: We measured serum 25-hydroxyvitamin D (25(OH)D) levels of 223 NCAA Division I athletes between June 2012 and August 2012. The prevalence of normal (≥32 ng/mL), insufficient (20 to <32 ng/mL), and deficient (<20 ng/mL) vitamin D levels was determined. Logistic regression was utilized to analyze risk factors for abnormal vitamin D levels. Results: The mean serum 25(OH)D level for the 223 members of this study was 40.1 ± 14.9 ng/mL. Overall, 148 (66.4%) participants had sufficient 25(OH)D levels, and 75 (33.6%) had abnormal levels. Univariate analysis revealed the following significant predictors of abnormal vitamin D levels: male sex (odds ratio [OR] = 2.83; P = 0.0006), Hispanic race (OR = 6.07; P = 0.0063), black race (OR = 19.1; P < 0.0001), and dark skin tone (OR = 15.2; P < 0.0001). Only dark skin tone remained a significant predictor of abnormal vitamin D levels after multivariate analysis (adjusted OR = 15.2; P < 0.0001). Conclusion: In a large cohort of NCAA athletes, more than one third had abnormal vitamin D levels. Races with dark skin tones are at much higher risk than white athletes. Male athletes are more likely than female athletes to be vitamin D deficient. Our study demonstrates a high prevalence of vitamin D deficiency among healthy NCAA athletes. Clinical Relevance: Many studies indicate a significant prevalence of vitamin-D insufficiency across various populations. Recent studies have demonstrated a direct relationship between serum 25(OH)D levels and muscle power, force, velocity, and optimal bone mass. In fact, studies examining muscle biopsies from patients with low vitamin D levels have demonstrated atrophic changes in type II muscle fibers, which are crucial to most athletes. Furthermore, insufficient 25(OH)D levels can result in secondary hyperparathyroidism, increased bone turnover, bone loss, and increased risk of low trauma fractures and muscle injuries. Despite this well-documented relationship between vitamin D and athletic performance, the prevalence of vitamin D deficiency in NCAA athletes has not been well studied.
Sports Health: A Multidisciplinary Approach | 2015
Anthony Yi; Diego Villacis; Raj Yalamanchili; George F. Rick Hatch
Context: Despite the significant attention directed toward optimizing arthroscopic rotator cuff repair, there has been less focus on rehabilitation after rotator cuff repair surgery. Objective: To determine the effect of different rehabilitation protocols on clinical outcomes by comparing early versus late mobilization approaches and continuous passive mobilization (CPM) versus manual therapy after arthroscopic rotator cuff repair. Data Sources: PubMed was searched for relevant articles using the keywords rotator cuff, rotator, cuff, tears, lacerations, and rehabilitation to identify articles published from January 1980 to March 2014. Study Selection: Inclusion criteria consisted of articles of level 1 or 2 evidence, written in the English language, and with reported outcomes for early versus late mobilization or rehabilitation with CPM versus manual therapy after primary arthroscopic rotator cuff repair. Exclusion criteria consisted of articles of level 3, 4, or 5 evidence, non-English language, and those with significantly different demographic variables between study groups. Included studies were evaluated with the Consolidated Standards of Reporting Trials criteria. Study Design: Systematic review. Level of Evidence: Level 2. Data Extraction: Level of evidence, study type, number of patients enrolled, number of patients at final follow-up, length of follow-up, age, sex, rotator cuff tear size, surgical technique, and concomitant operative procedures were extracted from included articles. Postoperative data included clinical outcome scores, visual analog score for pain, shoulder range of motion, strength, and rotator cuff retear rates. Results: A total of 7 studies met all criteria and were included in the final analysis. Five studies compared early and late mobilization. Two studies compared CPM and manual therapy. Conclusion: In general, current data do not definitively demonstrate a significant difference between postoperative rotator cuff rehabilitation protocols that stress different timing of mobilization and use of CPM.
Orthopedics | 2013
Jarrad Merriman; Diego Villacis; Curtis J. Kephart; George F. Rick Hatch
The authors present a rare technique of tension band plating of the anterior tibia in the setting of a nonunion stress fracture. Surgical management with an intramedullary nail is a viable and proven option for treating such injuries. However, in treating elite athletes, legitimate concerns exist regarding the surgical disruption of the extensor mechanism and the risk of anterior knee pain associated with intramedullary nail use. The described surgical technique demonstrates the use of tension band plating as an effective treatment of delayed union and nonunion anterior tibial stress fractures in athletes without the potential risks of intramedullary nail insertion.
Orthopaedic Journal of Sports Medicine | 2015
Anthony Yi; Dhanur Damodar; Michael Dacey; Diego Villacis; George F. Rick Hatch
Objectives: Although dislocation of the knee is rare, the high-energy nature of most injuries often results in high morbidity and sometimes limb-threatening injury. Literature regarding knee dislocations tends to focus upon management. There is a lack of research investigating quality of life for patients having undergone multi-ligament knee reconstruction. The purpose of our study was to review quality of life and functional outcomes as well as examine preoperative variables that may affect these outcomes for patients having undergone multi-ligament knee reconstruction. Methods: Retrospectively, we identified a total of 31 patients who underwent a standardized method of surgical reconstruction for multi-ligament knee injuries since 2006 at a single institution. A single surgeon performed all operations. A total of 28 knees (26 patients) were included in the final analysis. We contacted patients at a minimum of 12 months postoperatively (mean: 40.5 months; range: 12-111 months) and administered the Multi-ligament Quality of Life Questionnaire (ML-QOL), 2000 International Knee Documentation Committee Subjective Knee Form (IKDC), and Lysholm Knee Scoring Scale. We performed independent two-sample t-tests to examine the difference in quality of life and functional measures for the following factors: age (≤ 40 vs. > 40), sex, mechanism of injury, time to surgery ( 3 weeks), vascular injury, nerve injury, concomitant fracture, other injuries, Schenk classification for knee dislocation, manipulation, surgical release, previous knee ligament surgery, and subsequent revision. We then performed age-adjusted multivariable linear regression analysis, including factors that we found to be statistically significant in univariate analysis. A p-value of 0.05 was used for statistical significance and all analysis was performed using STATA (College Station, TX). Results: For ML-QOL, we found that patients who had undergone previous knee ligament surgery had significantly worse mean scores relative to patients who had not undergo previous knee ligament surgery (122.9 vs. 80.2; p = 0.001) (higher score indicates worse quality of life). All other differences in ML-QOL scores were not statistically significant. IKDC and Lysholm scores did not differ significantly with regards to the studied variables. After stratifying patients by history of previous knee ligament surgery (7 vs. 21), we found that patients with Schenk classifications of III or IV had significantly worse mean ML-QOL scores relative to patients with Schenk classifications of I or II (91.3 vs. 62.1; p = 0.0152). Conclusion: To our knowledge, our study is the first to investigate both quality of life and functional outcome measures for patients undergoing multi-ligament reconstruction after knee dislocation. We found that patients with a previous history of knee ligament surgery had a significantly worse quality of life relative to those with no history of knee ligament surgery. Among patients with no history of knee ligament surgery, higher Schenk classification was associated with worse ML-QOL scores.
Clinics in Orthopedic Surgery | 2016
Reza Omid; Chris Kidd; Anthony Yi; Diego Villacis; Eric A. White
Background Nonoperative management of midshaft clavicle fractures has resulted in widely disparate outcomes and there is growing evidence that clavicle shortening poses the risk of unsatisfactory functional outcomes due to shoulder weakness and nonunion. Unfortunately, the literature does not clearly demonstrate the superiority of one particular method for measuring clavicle shortening. The purpose of this study was to compare the accuracy of clavicle shortening measurements based on plain radiographs with those based on computed tomography (CT) reconstructed images of the clavicle. Methods A total of 51 patients with midshaft clavicle fractures who underwent both a chest CT scan and standardized anteroposterior chest radiography on the day of admission were included in this study. Both an orthopedic surgeon and a musculoskeletal radiologist measured clavicle shortening for all included patients. We then determined the accuracy and intraclass correlation coefficients for the imaging modalities. Bland-Altman plots were created to analyze agreement between the modalities and a paired t-test was used to determine any significant difference between measurements. Results For injured clavicles, radiographic measurements significantly overestimated the clavicular length by a mean of 8.2 mm (standard deviation [SD], ± 10.2; confidence interval [CI], 95%) compared to CT-based measurements (p < 0.001). The intraclass correlation was 0.96 for both plain radiograph- and CT-based measurements (p = 0.17). Conclusions We found that plain radiograph-based measurements of midshaft clavicle shortening are precise, but inaccurate. When clavicle shortening is considered in the decision to pursue operative management, we do not recommend the use of plain radiograph-based measurements.
Indian Journal of Orthopaedics | 2015
Anthony Yi; Ioannis A. Avramis; Evan Argintar; Eric R White; Diego Villacis; George F. Rick Hatch
Background: Rotator cuff pathology occurs commonly and its cause is likely multifocal in origin. The development and progression of rotator cuff injury, especially in relation to extrinsic shoulder compression, remain unclear. Traditionally, certain acromial morphologies have been thought to contribute to rotator cuff injury by physically decreasing the subacromial space. The relationship between subacromial space volume and rotator cuff tears (RCT) has, however, never been experimentally confirmed. In this study, we retrospectively compared a control patient population to patients with partial or complete RCTs in an attempt to quantify the relationship between subacromial volume and tear type. Materials and Methods: We retrospectively identified a total of 46 eligible patients who each had shoulder magnetic resonance imaging (MRI) performed from January to December of 2008. These patients were stratified into control, partial RCT, and full-thickness RCT groups. Subacromial volume was estimated for each patient by averaging five sequential MRI measurements of subacromial cross-sectional areas. These volumes were compared between control and experimental groups using the Students t-test. Results: With the numbers available, there was no statistically significant difference in subacromial volume measured between: the control group and patients diagnosed partial RCT (P > 0.339), the control group and patients with complete RCTs (P > 0.431). Conclusion: We conclude that subacromial volumes cannot be reliably used to predict RCT type.