The Evolution of Anterior Total Hip Arthroplasty The Past, Present, and Future.

The anterior approach has become a widely used and accepted approach for total hip arthroplasty (THA). This approach offers a number of advantages including supine positioning, improved soft tissue management, and avoidance of taking down posterior structures. The approach has evolved significantly from its introduction in the late 19th Century due to advancements in technology. Specifically, developments in the table used for the approach, safer instrumentation, and fluoroscopic guidance with overlay technologies have helped the anterior approach gain popularity. This article reviews the evolution of the usage of the anterior approach, including the use of current and emerging technologies as well as the learning curve associated with switching to the anterior THA and the future of outpatient anterior THA.

Open Surgical Management of Chronic Exertional Compartment Syndrome of the Leg.

PURPOSE: The purpose of this study is to present one institution's experience managing chronic exertional compartment syndrome (CECS) and to identify patient and surgical characteristics associated with better outcomes following open surgical management of CECS with specific emphasis on return to sports. METHODS: Fifteen patients (10 male, 5 female) who underwent open fasciotomy for CECS with a minimum of 1-year follow-up were included. Chart review was performed to obtain patient demographics, medical and surgical history, presenting symptomatology, and surgical details of fasciotomy. Outcomes were assessed using follow-up questionnaires that consisted of Tegner Activity Scale, EuroQol-5D (EQ5D) index score, EQ-5D rating scale, symptom resolution, patient satisfaction, and return to sports. RESULTS: The mean patient age at the time of surgery was 28.1 years (range: 17 to 49 years). At mean follow-up of 2.7 years (range: 1.0 to 5.1 years), five patients reported complete resolution of symptoms, eight reported improvement (but not resolution) of symptoms, one reported no change in symptoms, and one reported worsening of symptoms. The mean Tegner Activity Score was 6.7 (range: 1 to 9) prior to injury and 4.7 (range: 1 to 9) postoperatively. Patients with any preoperative symptoms at rest had significantly lower Tegner before score (4.0 vs. 7.1, p = 0.036) and EQ5D rating (50.0 vs. 83.5, p = 0.04) compared to those that only experienced symptoms with activity. Patients that had prior surgery, including fasciotomy, had significantly lower EQ-5D rating than patients with no history of prior lower extremity surgery (56.7 vs. 84.6, p = 0.045). Although 10 (66%) patients were able to return to sports, only four (27%) of them were able to return to their prior level of sport. The overall satisfaction rate was 87%. CONCLUSION: Although open surgical fasciotomy for treatment of chronic exertional compartment syndrome leads to high rates of symptom improvement or resolution, fewer patients are able to return to their prior level of sports. Presence of symptoms at rest, presence of bilateral symptoms, and history of prior lower extremity surgery all portend worse outcomes.

Correlation Between Synovial Fluid Biomarkers and Leg-Fat Area Ratios in Patients Undergoing ACL Reconstruction With or Without an Associated Meniscectomy.

PURPOSE: This study attempts to establish whether local adiposity of the knee at the level of the joint line is associated with alterations in synovial fluid biomarker concentrations in patients undergoing ACL reconstruction with or without an associated meniscectomy. METHODS: Patients undergoing ACL reconstruction were prospectively enrolled at the time of surgery from July 2011 to January 2015. Synovial fluid samples were collected just prior to incision and the concentrations of 10 biomarkers of interest were determined using a multiplex magnetic bead immunoassay. Knee adiposity was assessed via measures of leg fat area using magnetic resonance axial T2 images at the level of the joint line. Measurement was determined by subtracting the sum of the joint area, consisting of bony and muscle areas, from the total leg area with six different ratios assessed. Groups were evaluated by injury type (isolated ACL, ACL + meniscal injury, and total cohort). The correlation between synovial fluid biomarker levels and leg fat area ratios was evaluated using Spearman's correlation. RESULTS: There were 22 females and 26 males, with a mean age of 33.8 years (± 10.5) and a mean BMI of 25.3 (± 4.0). In the setting of isolated ACL injury, there was a statistically significant correlation between leg fat ratios and interleukin- 6, vascular endothelial growth factor, and interleukin-1 receptor antagonist. In patients with concomitant meniscal tears, there was an inverse correlation between leg fat ratios and monocyte chemoattractant protein-1. CONCLUSION: The leg fat to total leg volume ratio and leg fat to joint space volume ratio were the most consistent measures for alterations in post-injury synovial fluid biomarker concentrations. Analysis of synovial fluid at the time of ACL reconstruction demonstrated significant correlations between specific leg-fat area ratios and synovial fluid biomarker concentrations. Local adiposity around the knee joint appears to modulate the biochemical environment of the joint and can clinically help guide prognostic discussions with the patient.

Effect of the Distal Femoral Joint Line on Ligament Tensions in Flexion with Cruciate-Retaining Total Knee Prostheses.

Proper ligament tension in knee flexion within cruciate-retaining (CR) total knee arthroplasty has long been associated with clinical success; however, traditional balancing principles have assumed that the distal femoral joint line (DFJL) affects only extension. The purpose of this study was to determine the effect DFJL may have on ligament strains and tibiofemoral kinematics of CR knee designs in flexion. A computational analysis was performed using a musculoskeletal modeling system for two different knee implants, the high-flex CR (HFCR) and guided-motion CR (GMCR). Tibiofemoral kinematics and ligament strain were measured at 90-degree knee flexion while the implants' DFJL was incrementally shifted proximally. Femoral implant position and kinematics were used to determine the femur's anteroposterior position relative to the tibia. The change in the femoral medial condyle position relative to the tibia was 0.33 mm and 0.53 mm more anterior per each 1-mm elevation of the DFJL for HFCR and GMCR, respectively. The change in the lateral condyle position was 0.20 mm more anterior and 0.06 mm more posterior for HFCR and GMCR, respectively. The strain in the lateral and medial collateral ligaments changed minimally with elevation of the DFJL. In both implants, strain increased in the anterior lateral and posterior medial bundles of the posterior collateral ligament with elevation of the DFJL, whereas strain decreased in the iliotibial band and iliotibial patellar band. Our findings suggest that DFJL affects ligament tension at 90-degree knee flexion and therefore flexion balance for CR implants. Elevating the DFJL to address tight extension space in a CR knee while flexion space is well balanced could result in increased flexion tension especially when the flexion-extension mismatch is large. To achieve balanced flexion and extension, the amount of DFJL elevation may need to be reduced.

Cytotoxicity evaluation of chlorhexidine gluconate on human fibroblasts, myoblasts, and osteoblasts.

Introduction: Chlorhexidine gluconate (CHX) is widely used as a preoperative surgical skin-preparation solution and intra-wound irrigation agent, with excellent efficacy against wide variety of bacteria. The cytotoxic effect of CHX on local proliferating cells following orthopaedic procedures is largely undescribed. Our aim was to investigate the in vitro effects of CHX on primary fibroblasts, myoblasts, and osteoblasts. Methods: Cells were exposed to CHX dilutions (0%, 0.002%, 0.02%, 0.2%, and 2%) for either a 1, 2, or 3-minute duration. Cell survival was measured using a cytotoxicity assay (Cell Counting Kit-8). Cell migration was measured using a scratch assay: a "scratch" was made in a cell monolayer following CHX exposure, and time to closure of the scratch was measured. Results: All cells exposed to CHX dilutions of ≥ 0.02% for any exposure duration had cell survival rates of less than 6% relative to untreated controls (p < 0.001). Cells exposed to CHX dilution of 0.002% all had significantly lower survival rates relative to control (p < 0.01) with the exception of 1-minute exposure to fibroblasts, which showed 96.4% cell survival (p = 0.78). Scratch defect closure was seen in < 24 hours in all control conditions. However, cells exposed to CHX dilutions ≥ 0.02% had scratch defects that remained open indefinitely. Conclusions: The clinically used concentration of CHX (2%) permanently halts cell migration and significantly reduces survival of in vitro fibroblasts, myoblasts, and osteoblasts. Further in vivo studies are required to examine and optimize CHX safety and efficacy when applied near open incisions or intra-wound application.

Guidelines for Instrumentation for Total Knee Replacement Based on Frontal Plane Radiographs.

OBJECTIVE: The objective of this study was to measure the dimensions and the angulations of the femur and tibia for arthritic knees that were scheduled for total knee surgery. The purpose was to provide information for the design of surgical instruments such as cutting guides. Instruments made using three-dimensional printing were a particular consideration because of the variations in sizing that are possible. MATERIALS AND METHODS: Sixty-six frontal plane EOS radiographs were obtained of patients with osteoarthritis who were under consideration for total knee arthroplasty. The images were imported into computer-assisted design software. The anatomic and mechanical axes and the joint lines were constructed for the femur and tibia. The angles between the axes and lines and key dimensions including the femoral canal diameters were measured. RESULTS: The angle between the anatomic and mechanical axes was 5.5° ± 1.4°, the femoral joint line sloped 2.2°, and the tibial joint line 4.3° to the mechanical axes. The values were similar to non-arthritic knees except for a higher tibial slope. The femoral canal diameter at 150 mm from distal was 19 ± 5 mm. CONCLUSIONS: In a total knee replacement procedure, aligning perpendicular to the mechanical axis results on average about 2° more valgus and 2° to 3° tilt of the joint line. Instruments could be calibrated for individual patients, but the maximum variations based on long-term follow-up should be recognized. A multi-diameter system is needed for the femoral intramedullary rod to limit errors to 1° or less.

Povidone-iodine Solutions Inhibit Cell Migration and Survival of Osteoblasts, Fibroblasts, and Myoblasts.

STUDY DESIGN: In vitro laboratory study. OBJECTIVE: The purpose of this study was to identify the effect of dilute povidone-iodine (PVI) solutions on human osteoblast, fibroblast and myoblast cells in vitro. SUMMARY OF BACKGROUND DATA: Dilute PVI wound lavage has been used successfully in spine and joint arthroplasty procedures to prevent postoperative surgical site infection, but their biologic effect on host cells is largely unknown. METHODS: Human primary osteoblasts, fibroblasts, and myoblasts were expanded in cell culture and subjected to various concentrations of PVI (0%, 0.001%, 0.01%, 0.1%, 0.35%, 1%) for 3 minutes. To assess the effect of PVI on cell migration, a scratch assay was performed, in which a "scratch" was made by a standard pipette tip in a cell monolayer following PVI exposure, and time to closure of the scratch was evaluated. Cell survival and proliferation was measured 48 hours post-PVI exposure using a cell viability and cytotoxicity assay. RESULTS: Closure of the scratch defect in all cell monolayers was achieved in <24 hours in untreated controls and following exposure to PVI concentrations <0.1%. The scratch defect remained open indefinitely following exposure to PVI concentrations of ≥0.1%. PVI concentrations <0.1% did not have significant effect on survival rates compared with control for all cell types. Cells exposed to PVI ≥ 0.1% had cell survival rates of less than 6% (P < 0.05). CONCLUSIONS: Clinically used concentration of PVI (0.35%) exerts a pronounced cytotoxic effect on osteoblasts, fibroblast, and myoblasts in vitro. Further investigation is required to systematically study the effect of PVI on tissue healing in vivo and also determine a safe and clinically potent concentration for PVI lavage. LEVEL OF EVIDENCE: N/A.

An epidermal inclusion cyst mimicking chronic prepatellar bursitis: a case report.

Soft tissue lesions are common to the prepatellar region, often due to acute or chronic trauma, and most frequently include prepatellar bursitis, lipomas, and ganglion cysts. We report a case of a posttraumatic prepatellar epidermal inclusion cyst to highlight the diagnostic complexities that can arise with soft tissue lesions in this location. On the basis of our case report, treating orthopaedic surgeons should consider the possibility of an epidermal inclusion cyst in patients who present with atypical anterior soft tissue masses with a history of trauma to the anterior knee.