Kenneth D. Illingworth

A Simple Evaluation of Anterior Cruciate Ligament Femoral Tunnel Position: The Inclination Angle and Femoral Tunnel Angle

Background: Postoperative determination of tunnel position after anterior cruciate ligament (ACL) reconstruction can be challenging. Hypothesis: The femoral tunnel angle and inclination angle are reliable methods for evaluating tunnel position after ACL reconstruction while aiding in determining whether an ACL reconstruction falls outside an anatomic range as defined on 3-dimensional (3D) computed tomography (CT). Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Fifty patients were included who received single-bundle ACL reconstructions with postoperative flexion weightbearing radiographs, magnetic resonance imaging (MRI), and CT scans. Femoral tunnel angles were determined from posterior-to-anterior postoperative radiographs, and inclination angles were determined from sagittal MRI. The ACL reconstructions were grouped by surgical technique, transtibial (TT) or tibial tunnel independent (TTI), and as either falling inside or outside an anatomic range on 3D CT. Results: Patients with tunnel positions within an anatomic range, as previously defined, had a larger femoral tunnel angle (39.3° ± 4.2°) and smaller inclination angle (49.5° ± 2.7°) than patients who fell outside an anatomic range (17.2° ± 12.5° and 62.3° ± 7.8°, respectively) (P < .001). Patients in the TTI group had a larger femoral tunnel angle (37.6° ± 9.30°) and smaller inclination angle (51.8° ± 6.5°) than those in the TT group (14.2° ± 9.3° and 63.5° ± 7.2°, respectively) (P < .001). Posterior-to-anterior femoral tunnel position was negatively correlated with femoral tunnel angle (P < .001, r = .78) and positively correlated with inclination angle (P < .001, r = .74). Based on a receiver operating characteristic (ROC) curve, a femoral tunnel angle of 32.7° (100% sensitivity and 85% specificity) and inclination angle of 55° (100% sensitivity and 87.5% specificity) were determined to distinguish ACL reconstructions that fell either within or outside an anatomic range on 3D CT. Conclusion: Femoral tunnel angle and inclination angle can be reliably determined from both posterior-to-anterior radiographs and sagittal MRI and provide a useful metric for characterizing femoral tunnel position.

How to Minimize Infection and Thereby Maximize Patient Outcomes in Total Joint Arthroplasty: A Multicenter Approach

Total joint arthroplasty is one of the most common and most successful orthopaedic procedures. Infection after total joint arthroplasty is a devastating problem that expends patient, surgeon, and hospital resources, and it substantially decreases the chances of a successful patient outcome. Postoperative infection affects approximately 1% to 7% of all total joint arthroplasties, at a cost of approximately

Medial Portal Drilling: Effects on the Femoral Tunnel Aperture Morphology During Anterior Cruciate Ligament Reconstruction

50,000 per infection. Decreasing postoperative periprosthetic joint infection is of the utmost importance for the total joint arthroplasty surgeon. Preoperative, perioperative, intraoperative, and postoperative measures to minimize infection and optimize patient outcomes in total joint arthroplasty are discussed. Preoperative measures include management of patients colonized by Staphylococcus aureus, nutritional optimization, and management of medical comorbidities. Perioperative measures include skin preparation and prophylactic antibiotics. Intraoperative measures include body exhaust suits, laminar flow, ultraviolet light, operating-room traffic control, surgical suite enclosures, anesthesia-related considerations, and antibiotic-loaded bone cement. Postoperative measures include continued antibiotic prophylaxis, blood transfusions, hematoma formation and wound drainage, duration of hospital stay, and antibiotic prophylaxis for future invasive procedures.

Review of periprosthetic osteolysis in total joint arthroplasty: An emphasis on host factors and future directions

BACKGROUND A goal of anatomic anterior cruciate ligament (ACL) reconstruction should be to create a femoral tunnel aperture that resembles the native attachment site in terms of size and orientation. Aperture morphology varies as a function of the drill-bit diameter, the angle in the horizontal plane at which the drilled tunnel intersects the lateral notch wall (transverse drill angle), and the angle of knee flexion in the vertical plane during drilling. METHODS A literature search was conducted to determine population-based dimensions of the femoral ACL footprint. The tunnel aperture length, width, and area associated with the use of different drill-bit diameters and transverse drill angles were calculated. The effect of the knee flexion angle on the orientation (anteroposterior and proximodistal dimension) and size of the femoral tunnel aperture relative to the native femoral insertion of the ACL were calculated with use of geometric mathematical models. RESULTS The literature search revealed an average femoral insertion site size of 8.9 mm for width, 16.3 mm for length, and 136.0 mm2 for area. The use of a 9-mm drill bit at a transverse drill angle of 40° resulted in a tunnel aperture area of 99.0 mm2 and a tunnel aperture length of 14.0 mm. Decreasing the transverse drill angle from 60° to 20° led to an increase of 152.9% in length and of 153.1% in tunnel aperture area. When a 9-mm drill bit and a transverse drill angle of 40° were used, the aperture seemed to best match the native ACL footprint when drilling was performed at a knee flexion angle of 102°; deviations from this angle in either direction resulted in increasing tunnel area mismatch compared with the baseline aperture. Increasing the knee flexion angle to 130° decreased the proximodistal dimension of the aperture by 2.78 mm and increased the anteroposterior distance by 0.65 mm, creating a mismatched area of 13.5%. CONCLUSIONS The drill-bit diameter, transverse drill angle, and knee flexion angle can all affect femoral tunnel aperture morphology in medial portal drilling during ACL reconstruction. The relationship between drilling orientation and aperture morphology is critical knowledge for surgeons performing ACL reconstruction.

Single walled carbon nanotube composites for bone tissue engineering

Periprosthetic osteolysis is one of the leading causes of total joint revision procedures. If allowed to progress in the absence of radiographic diagnosis and/or proper medical treatment, osteolysis may result in aseptic loosening yielding failure of the implant and the need for complex revision arthroplasty. The purpose of this review was to assess the current understanding of periprosthetic osteolysis with an emphasis on host factors and future directions. A PubMed search was conducted using the following key words; osteolysis, periprosthetic osteolysis, osteolysis imaging. Pertinent articles, as it pertained to the outline of the review, were selected. Periprosthetic osteolysis stems from numerous risk factors. Osteolysis host characteristic risk factors include gender, body weight, and genetics. Current implant designs have reduced the incidence of this disease; however no current design has been able to replicate the in vivo characteristics and therefore development of wear particles continues to be seen. Advanced methods of imaging diagnosis are on the rise, however early imaging diagnosis is currently ineffective. Pharmacologic intervention appears to be a logical avenue for medical intervention, but no approved drug therapy to prevent or inhibit periprosthetic osteolysis is currently available. Although the rate of periprosthetic osteolysis seems to be decreasing with advances in implant design and increased knowledge of the biological process of wear particle induced osteolysis, the rapid increase in the total number of total joint arthroplasties over the next two decades means that better ways of detecting and treating periprosthetic osteolysis are greatly needed.

Effect of social media in health care and orthopedic surgery.

The purpose of this study was to develop single walled carbon nanotubes (SWCNT) and poly lactic‐co‐glycolic acid (PLAGA) composites for orthopedic applications and to evaluate the interaction of human stem cells (hBMSCs) and osteoblasts (MC3T3‐E1 cells) via cell growth, proliferation, gene expression, extracellular matrix production and mineralization. PLAGA and SWCNT/PLAGA composites were fabricated with various amounts of SWCNT (5, 10, 20, 40, and 100 mg), characterized and degradation studies were performed. Cells were seeded and cell adhesion/morphology, growth/survival, proliferation and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated uniform incorporation of SWCNT into the PLAGA matrix and addition of SWCNT did not affect the degradation rate. Imaging studies revealed that MC3T3‐E1 and hBMSCs cells exhibited normal, non‐stressed morphology on the composites and all were biocompatible. Composites with 10 mg SWCNT resulted in highest rate of cell proliferation (p < 0.05) among all composites. Gene expression of alkaline phosphatase, collagen I, osteocalcin, osteopontin, Runx‐2, and Bone Sialoprotein was observed on all composites. In conclusion, SWCNT/PLAGA composites imparted beneficial cellular growth capabilities and gene expression, and mineralization abilities were well established. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration and bone tissue engineering (BTE) and are promising for orthopedic applications.

Hospital Length of Stay following Primary Total Knee Arthroplasty: Data from the Nationwide Inpatient Sample Database

With the growth of social media platforms, their potential to affect health care, and orthopedics specifically, continues to expand. We reviewed the literature to obtain all pertinent information on social media in health care and examined its strengths and weaknesses from patient and physician perspectives. Health care professionals have slowly begun to use social media to stay connected with patients. The recent use of networking sites aims to improve education, provide a forum to discuss relevant medical topics, and allow for improved patient care. The use of social media, with the understanding of its limitations, may help promote patient happiness and safety and serve as an educational platform.

Correlation Between Femoral Tunnel Length and Tunnel Position in ACL Reconstruction

Demand and cost of total knee arthroplasty (TKA) has increased significantly over the past decade resulting in decreased hospital length of stay (LOS) to counterbalance increasing cost of health care. The purpose of this study was to determine the factors that influence LOS following primary TKA. Discharge data from the 2009-2011 Nationwide Inpatient Sample were used. Patients included underwent primary TKA and were grouped based on LOS; 3 days or less, and 4 days or more. Majority of patients had a hospital LOS of 3 or less (74.8%). The most significant predictors of increased hospital LOS (≥ 4 days) were age ≥ 80 years, Hispanic race, Medicaid payer status, lower median household income, weekend admission, rural non-teaching hospital, discharge to another facility and any complication.

Inpatient Mortality After Primary Total Hip Arthroplasty: Analysis from the National Inpatient Sample Database

BACKGROUND The position of the femoral tunnel affects the osseous geometry available for drilling during anterior cruciate ligament (ACL) reconstruction. The length of the tunnel changes with changes in the tunnel position and may have implications for femoral fixation. METHODS Forty-seven patients with a single-bundle ACL reconstruction underwent computed tomography (CT) evaluation to generate three-dimensional (3D) CT bone models. With use of a previously described anatomic coordinate system, the center of the femoral tunnel was quantified in the posterior-anterior and proximal-distal dimensions on 3D CT. Tunnel length was defined as the distance between the centers of the intra-articular and extra-articular tunnel apertures. The reconstructed knees were dichotomized by anatomy and technique into anatomic (n = 20) and nonanatomic (n = 27) groups as well as according to whether they had undergone medial portal drilling (n = 20) or transtibial drilling (n = 27) for analysis. In addition, a review of the literature on the relationship between tunnel length and tendon-to-bone healing was performed. RESULTS Femoral tunnels drilled with nonanatomic footprints were longer (mean [and standard deviation], 43.6 ± 8.5 mm; range, 28.2 to 60.7 mm) than tunnels drilled with anatomic footprints (31.0 ± 6.3 mm; 21.2 to 42.5 mm) (p < 0.001). Tunnels drilled transtibially (44.4 ± 7.6 mm; 32.5 to 60.7 mm) were significantly longer than tunnels drilled through the medial portal (29.8 ± 5.0 mm; 21.2 to 40.3 mm) (p < 0.001). There was a strong correlation between tunnel length and posterior-anterior femoral tunnel position (r = 0.78, p < 0.05), with more anterior tunnel positioning associated with greater tunnel length. There was no correlation between posterior-distal femoral tunnel position and tunnel length (r = -0.05; p = 0.74). There was no consensus in the literature regarding adequate tunnel length for biologic fixation. CONCLUSIONS Femoral tunnels drilled with anatomic footprints had sufficient length for adequate femoral fixation. Femoral tunnels positioned anterior to the native insertion of the ACL were longer than those in anatomic position. CLINICAL RELEVANCE The results of this study can help the surgeon to consider the relationship between tunnel position and subsequent tunnel length in ACL reconstruction.

Patient Demographics and Risk Factors in Pediatric Distal Humeral Supracondylar Fractures

Although inpatient mortality rates following total hip arthroplasty are low, understanding factors that influence inpatient mortality rates is important. Discharge data from the 2007-2008 HCUP Nationwide Inpatient Sample database were used in this study. Patients were identified based on whether they were admitted for a primary total hip arthroplasty and grouped based on their mortality status. All hip and acetabular fracture patients were excluded. Discharge data revealed 508,150 primary total hip arthroplasties with an inpatient mortality rate of 0.13%. The most significant pre-operative predictors of inpatient mortality were increasing age, weekend admission, increased Charlson co-mobidity score, Medicare payer status, race and a Southern hospital region. The two most significant complications post-operatively leading to increased mortality were pulmonary and cardiovascular complications.