Faculty Bibliography

AIM: To review and report functional outcomes, complications, and survivorship associated with total knee arthroplasty (TKA) in the treatment of post-traumatic arthritis (PTA). METHODS: We conducted a systematic review according to the PRISMA guidelines. We searched PubMed, Cochrane Library, and SCOPUS in December 2015 for English-language clinical research studies, both prospective and retrospective, examining the use of TKA for the treatment of PTA. All relevant articles were accessed in full. The manual search included references of retrieved articles. We extracted data on patients' demographics and clinical outcomes, including preoperative diagnosis and pre- and post-operative functional scores. We summarized the data and reported the results in tables and text. RESULTS: Sixteen studies, four prospective and ten retrospective, examined patients who underwent TKA for PTA due to fractures of the proximal tibia, patella, and/or distal femur. Eleven studies utilized the Knee Society Scores criteria to assess functional outcomes. All studies utilizing these criteria reported an improvement in functional and knee scores of patients following TKA. Further, studies reported an increased range of motion (ROM) and reduction of pain following surgery. The most commonly reported complications with TKA included infection, stiffness, wound complications, intraoperative rupture of tendons, and osteolysis/polyethylene wear. The overwhelming majority of these complications occurred within the first two years following surgery. Six studies examined the survivorship of TKA with subsequent revision for any reason as an endpoint. Compared to patients with osteoarthritis, patients with PTA required more revisions, the majority for polyethylene wear. CONCLUSION: Although associated with higher complication rates, TKA is an effective treatment for PTA, as it improves ROM, pain and functional outcomes.

Total hip arthroplasty (THA) is an increasingly common procedure among elderly individuals. Although conversion THA is currently bundled in a diagnosis related group (DRG) with primary THA, no study has identified whether conversion THA better resembles a primary or revision THA. The American College of Surgeons National Surgical Quality Improvement Project database was queried to identify 2009 conversion THA, 67,854 primary THA, and 5,089 revision THA procedures between 2009 and 2014. Univariate analysis was used to compare fifty-three preoperative, intraoperative, and postoperative variables. Seventeen variables demonstrated a statistical difference between conversion and primary THA without a corresponding difference between conversion and revision THA. Only one variable demonstrated a difference between conversion and revision THA without a similar difference between conversion and primary THA. This imbalance suggests that conversion THA better resembles revision THA characteristics, and that these procedures should be reclassified in the same DRG as revision THA instead of primary THA.

BACKGROUND: Despite the alleviation of osteoarthritis (OA) symptoms that total knee arthroplasty (TKA) provides for patients with end-stage knee OA, recent studies have suggested that TKA may not increase physical activity levels. In this study, we compare the physical activity levels of patients with OA treated nonoperatively (non-TKA) with both patients who had received TKA (post-TKA) and patients who received TKA within 3 years of data collection (pre-TKA). METHODS: Utilizing the Osteoarthritis Initiative database, accelerometry data were collected from non-TKA, pre-TKA, and post-TKA patients. Accelerometry data were subdivided by physical activity intensity levels, yielding daily minutes of each level of activity. Physical activity levels were then compared between non-TKA and pre-TKA/post-TKA patients. Physical activity levels for each patient were also compared to the Department of Health and Human Services (DHHS) guidelines for physical activity. RESULTS: There was no difference in physical activity between non-TKA and pre-TKA patients, with the exception of non-TKA patients achieving more daily minutes of vigorous activity (P < .001). There was no difference in physical activity between non-TKA and post-TKA patients. Although 11.6% of non-TKA patients met DHHS guidelines, only 4.8% of pre-TKA and 5.3% of post-TKA patients met guidelines. CONCLUSION: Despite the improvements in patient-reported outcome measures following TKA, we found that TKA alone does not improve physical activity levels beyond those seen in the average patient with OA. In our study, the vast majority of patients with OA, treated nonoperatively or operatively, did not meet current DHHS guidelines for physical activity.

Introduction/objectives: Individuals co-infected with both HCV) and HIV represent a unique and growing population of patients undergoing orthopaedic surgical procedures. Data regarding complications for HCV monoinfection or HIV monoinfection is robust, but there exists a paucity of data regarding coinfected individuals. Methods: State-wide database was used to identify patients undergoing THA between 2010-2014. Patients were stratified into 4 groups based upon HCV/HIV status: healthy controls without disease, HCV monoinfection, HIV monoinfection, and co-infection. Differences regarding hospital LOS (days), total charges ($USD), discharge disposition, in-hospital complications, in-hospital mortality, and hospital readmission were calculated. Results: 80,722 patients underwent THA between 2010-2014. 98.55% had neither HCV nor HIV, 0.66% had HCV, 0.66% HIV and 0.13% were coinfected with both HCV and HIV. Co-infected patients were more likely to be younger, male, insured by Medicaid, history of AVN and be homeless. Additionally, co-infected patients had the highest rates of alcohol abuse, drug abuse, tobacco, and high rates of psychiatric disorders, including depression. HCV and HIV co-infection was an independent risk factor for increased LOS (p<0.001), total hospital charges in the 90th percentile (p<0.001), having 2 or more in-hospital complications (p<0.001), and 90-day readmission rates (p<0.001). Conclusions: As the prevalence of HCV and HIV co-infectivity continues to increase, surgeons will encounter a greater number of these patients. Awareness of the demographic and socioeconomic factors leading to increased complications after THA will allow physicians to consider interventions to improve patient health status in order to optimize outcomes and reduce costs

Introduction/objectives: Spinal deformity has a known deleterious effect upon the outcomes of THA and acetabular component positioning. This study sought to evaluate the relationship between severity of spinal deformity parameters and acetabular cup position, rate of dislocation, and rate of revision among patients with THAs and concomitant spinal deformity. Methods: A prospectively database of patients with spinal deformity was reviewed and patients with THA were identified. The full standing stereoradiographic images (EOS) were reviewed. Spinal deformity parameters and acetabular cup anteversion and inclination were measured. A chart review was performed to determine dislocation and revision arthroplasty events. Statistical analysis was performed to determine correlation of deformity with acetabular cup position. Subgroup analysis was performed for spinal fusion, dislocation events, and revision THA. Results: 142 patients were identified with THA and spinal deformity, with 152 hips. The rate of dislocation was 5.7%, with a revision rate of 3.6% for instability. Only 42.1% met the radiographic "safe zone" criteria. 7 (77.8%) of the 9 dislocations occurred in patients with acetabular cups outside the safe zone (p = 0.304). Patients with dislocations had significantly higher inclination than those patients who did not dislocate (p = 0.016), but had no difference in anteversion (p = 0.646). Conclusions: In this cohort, patients with THA and concomitant spinal deformity have a high dislocation rate and a high percentage of acetabular cups which lie outside the safe zone in the standing position. Known spinal deformity parameters and the presence of spinal fusion do not correlate strongly with cup position or dislocation rates

Introduction/objectives: Adult spinal deformity correction results in changes in acetabular anteversion. Spinopelvic fusion reduces the protective motion of the pelvis between sitting and standing to prevent THA dislocation. Our hypothesis is that spinal deformity correction may result in dislocation of previously stable THA due to changes in acetabular orientation and fixation to the pelvis. Methods: Patients with previously implanted THA were identified from a prospective database of spinal realignment patients if they had a THA in situ prior to spinal surgery. Only patients with at least 6 months postoperative follow-up and visible THA prostheses were included. All postoperative imaging was reviewed. A chart review was performed to determine the indication for revision THA. Acetabular orientation and global/regional spinopelvic parameter were measured pre-and post-SSD correction. Results: 42 patients met criteria. 27 of these patients underwent a 3-column osteotomy. Four patients (7.2% of patients-5.7% hips) required revision THA after spinal realignment procedure: all revisions were for recurrent dislocations. All had stable THAs prior to spinal realignment. All acetabular components were within Lewinnek's 'safe zone' after ASD correction. There was no difference between the revised and non-revised group in mean anteversion or inclination. All hips requiring revision were fused to the pelvis as part of their SSD correction. Conclusions: Dislocation of a previously stable THA is a potential complication after ASD correction. Instability may be a result of a combination of change in alignment of the acetabular prosthesis, as well as reduced spinopelvic motion from spinopelvic fusion

Introduction/objectives: Lumbar fusion is known to reduce the variation in pelvic tilt between standing and sitting by reducing flexibility of the lumbar spine. Flexibility of the lumbo-pelvic segment theoretically improves stability of a hip replacement during sitting by increasing anterior clearance and acetabular anteversion, thus preventing prosthetic impingement. The effect of lumbar fusion on stability of THA has not been previously investigated. Methods: Medicare database was searched from 2005 to 2012 for patients who underwent THA and spinal fusion. PearlDiver software was used to query the database by ICD-9 procedural code for primary THA and lumbar spinal fusion. The lumbar fusion and THA patients were then divided into three groups-1-2 levels fused, 3-7 levels, and 8 + levels. THA dislocation rates were searched within each group. Patients undergoing THA but no spinal fusion were used as the control group. Statistical significant difference between groups was tested with chi-squared test, and significance at p<0.05. Results: 2912 patients were identified to have THA after lumbar spinal fusion (2420 1-2 level, 476 3-7 level) and 2-year follow-up. The control group of THA patients with no history of spinal fusion consisted of 839,004 patients. The dislocation rate in the control group was 1.55%. Higher dislocation rates were found in patients with spinal fusion of 1-2 levels (2.73%, p<0.0001), 3-7 levels (4.62%, p<0.0001). Patients with 3-7 levels fused had higher dislocation rates than patients with 1-2 levels fused (p<0.0001). Conclusions: Patients with a previous history of lumbar spinal fusion have significantly higher rates of dislocation of their THA than patients without lumbar spinal fusions, and longer fusion segments also had higher dislocation rates

Introduction/objectives: Peri-prosthetic joint infections (PJI) are a continued concern in arthroplasty surgery. The rate of PJIs for total hip arthroplasty (THA) procedures varies from 0.3% to 2.9%. Irrigation & debridement (I&D) with a head and liner exchange is often performed to treat this complication. Early management of PJI is cited to offer a higher success rate. The purpose of this study is to evaluate the efficacy and timing of I&D for PJI in THA. Methods: We reviewed the records of 39 patients that underwent a THA between January 5th, 2009 and October 30th, 2014 who subsequently had an I&D with a head and liner exchange to treat a PJI. Date of THA and date of I&D with ahead and liner exchange were recorded. Success was measured by the need for any additional procedure due to persistent infection. Results: The average time between THA and I&D with a head and liner exchange was 48 days. Successful I&Ds took place an average of 46.8 days after the initial THA while unsuccessful I&Ds were performed 51.6 days after the initial THA. The difference, however, was not statistically significant. Conclusions: Our results demonstrate the average time to I&D with a head and liner exchange was shorter for those who had a successful outcome but the difference between the two groups was not significant. A short time interval between arthroplasty and I&D is recommended by most authors but our results did not support this view