Wearing a Surgical Vest With a Sterile Surgical Helmet System Decreases Contamination of the Surgical Field.

BACKGROUND: Sterile surgical helmet systems are frequently utilized in total knee arthroplasty procedures to protect the surgeon while maintaining a comfortable working environment. However, common helmet systems pressurize the space between the surgical gown and the surgeon's skin. In gowns with a back seam, this may allow contaminated skin particles to escape into the surgical field. By measuring bacterial colony-forming units (CFUs), this study sought to determine if occlusion of the open back seam reduced the risk of potential contamination. METHODS: First, qualitative analysis depicting airflow variations between gown configurations was performed using the Schlieren Spherical Mirror imaging system. Each gown configuration consisted of a sterile surgical helmet and one of 3 gown configurations: a standard gown with rear-tied closure, a standard gown with a surgical vest, and a zippered Toga-style gown. Next, a surgeon then performed simulated surgical activities for 60 minutes within a 1.4 m3 isolation chamber with work surfaces and controllable filtered air exchanges. During each procedure, contaminated particles were collected on sets of agar settle plates positioned directly behind the surgeon. Upon completion, the agar plates were incubated in a biolab, and the number of bacterial and fungal CFUs was counted. The experimental procedure was repeated 12 times for each gown configuration, with sterilization of the chamber between runs. Contamination rates were expressed as CFUs/m2/h. RESULTS: The mean contamination rate measured with the standard gown was 331.7 ± 52.0 CFU/m2/h. After the addition of a surgical vest, this rate decreased by 45% to 182.2 ± 30.8 CFU/m2/h (P = .02). Similarly, with the Toga-style gown, contamination rates dropped by 49% to 170.5 ± 41.9 CFU/m2/h (P = .01). CONCLUSIONS: When used in conjunction with surgical helmet systems, conventional surgical gowns do not prevent potential contamination of the surgical field. We recommend that staff within the surgical field cover the back seam of standard gowns with a vest or don a zippered Toga-style gown.

Pelvic tilt affects superolateral coverage, but not superomedial coverage of the femoral head following periacetabular osteotomy.

BACKGROUND: Pelvic tilt is an important sagittal parameter that varies greatly among individuals. The objective of this study was to quantify the effect of pelvic tilt on femoral head coverage and range of motion in a dysplastic population following periacetabular osteotomy. METHODS: Twenty-three dysplastic hips from 19 patients (17 female, 2 male) were included in this study. Three-dimensional models were reconstructed using pre-operative CT images, and patient-specific neutral pelvic tilt was obtained on an anteroposterior X-ray. Following a simulated periacetabular osteotomy, the pelvic tilt was changed from -15° to +15°, and the effects on femoral head coverage and hip range of motion was quantified using a customized MATLAB program. FINDINGS: Pelvic tilt did not significantly affect total femoral head coverage (P > 0.2). However, a 15° anterior tilt from neutral resulted in a 17.72 ± 9.45% increase in anterolateral coverage and a 23.96 ± 7.48% decrease in posterolateral coverage (P < 0.0001), as well as an 18.2 ± 8.4° loss of internal rotation at 90° of hip flexion. Contrarily, posterior pelvic tilt led to a 26.79 ± 9.04% reduction in anterolateral coverage (P < 0.0001) and an 18.02 ± 9.57% increase in posterolateral coverage (P < 0.0001), and the maximum internal rotation increased 11.8 ± 3.7°. INTERPRETATION: While pelvic tilt did not affect total femoral head coverage, it had a significant impact on the distribution of coverage within the superolateral region of the femoral head. Anterior pelvic tilt led to increased anterolateral coverage, but also had a negative impact on hip range of motion. An optimal surgical plan should achieve adequate coverage while not significantly limiting the patient's mobility.

Variations in Trochlear Morphology of Contemporary and Legacy Total Knee Arthroplasty Prostheses: A Review of 22 Designs.

BACKGROUND: The morphology of the trochlear compartment of total knee arthroplasty (TKA) prostheses is a major determinant of postoperative patello-femoral kinematics, particularly with unresurfaced patellae. The objective of this study was to quantify and compare the trochlear morphology of a large series of contemporary and legacy TKA designs. METHODS: The 3-dimensional surface models of 22 femoral components (13 contemporary and 9 legacy) were created using high-resolution laser scanning. The trochlear profile of each component was analyzed from proximal to distal in 15° increments around the trochlear axis. In each profile, the following variables were measured: sulcus angle, medio-lateral deviation of the sulcus, the height and width of the facets, and the trochlear groove orientation. RESULTS: In the contemporary group, the sulcus angle decreased progressively along the trochlear arc to varying degrees, except for 2 symmetrical designs, whereas the sulcus angle of the legacy designs showed considerable variability. The height of the medial facet was very strongly correlated with that of the lateral facet in the contemporary group (R2 = 0.89), whereas the correlation was weak for the legacy designs (R2 = 0.36). Moreover, the trochlear sulcus deviated laterally from distal to proximal in 10 contemporary designs and 7 legacy designs, resulting in a trochlear groove orientation of 4.2 to 11.1° and 4.3 to 10.5°, respectively. In the remaining 5 designs (3 contemporary and 2 legacy), the sulcus was vertical. CONCLUSIONS: There is more consistency in trochlear morphology of contemporary TKA designs compared to that of legacy designs, yet there are still large variations between different designs.

The Influence of Computerized Tomography Imaging on Treatment of Periprosthetic Proximal Femur Fractures.

Introduction Periprosthetic femur fractures (PPFF) are increasing in incidence and management of such injuries requires a specialized skill set combined with detailed knowledge of component design. To assist with planning, computed tomography (CT) can be used pre-operatively to give a surgeon more information. No study to date has shown the utility of obtaining preoperative CT. The goal of this study is to show that CT is a useful diagnostic adjunct and report any differences in how subspecialties such as orthopedic traumatologists and arthroplasty surgeons use it. Methods Seventeen PPFF cases met our inclusion criteria. They were shown to six faculty, three trauma and three arthroplasty surgeons. They viewed the plain radiographs and then CTs. After each they filled out the same questionnaire that included their assessment of diagnosis and proposed treatment plan both before and after access to CT imaging. Fleiss and Cohen kappa were used to compare inter- and intra-observer reliability. Results The interobserver kappa values (k) in diagnosis were 0.348 pre- and 0.371 post-CT, while trauma and arthroplasty were 0.328 to 0.260 and 0.821 to 0.881 respectively. The interobserver reliability in treatment was 0.336 pre- and 0.254 post-CT, while trauma and arthroplasty were 0.323 to 0.288 and 0.688 to 0.519. For intraobserver the average k for diagnosis and treatment were 0.818 and 0.671. Broken down by subspecialty they were 0.874 and 0.831 and 0.762 and 0.510 for trauma and arthroplasty. There were 11 diagnostic and 24 treatment changes. Conclusion CT provides diagnostic changes 10% and treatment changes 24% of the time. However, it does not lead to greater agreement among the surgeons on either. Arthroplasty uses CT more to guide both their treatment and the diagnosis, and they agree more than trauma surgeons. Most of the treatment changes come from adding or removing a plate, and the most common diagnostic change was shared by A to B1 and B2 to B3. This suggests fracture extension and bone stock are better evaluated by CT.

The Stability of Fixation of Vancouver B2 Periprosthetic Femoral Fractures: Effect of Implantation Technique.

BACKGROUND: Due to increasing volume of total hip arthroplasties, periprosthetic femoral fractures have become a common complication with increased revision burden and perioperative morbidity. The objective of this study was to evaluate the fixation stability of Vancouver B2 fractures treated with 2 techniques. METHODS: A common B2 fracture was created by reviewing 30 type B2 cases. The fracture was then reproduced in 7 pairs of cadaveric femora. The specimens were divided into 2 groups. In Group I ("reduce-first"), the fragments were reduced first, followed by implantation of a tapered fluted stem. In Group II ("ream-first"), the stem was implanted in the distal femur first, followed by fragment reduction and fixation. Each specimen was loaded in a multiaxial testing frame with 70% of peak load during walking. A motion capture system was used to track the motion of the stem and fragments. RESULTS: The average stem diameter in Group II was 16.1 ± 0.4 mm, versus 15.4 ± 0.5 mm in Group I. The fixation stability was not significantly different in the 2 groups. After the testing, the average stem subsidence was 0.36 ± 0.31 mm and 0.19 ± 0.14 mm (P = .17) and the average rotation was 1.67 ± 1.30° and 0.91 ± 1.11° (P = .16) in Groups I and II, respectively. Compared to the stem, there was less motion of the fragments and there was no difference between the 2 groups (P > .05). CONCLUSIONS: When tapered fluted stems were used in combination with cerclage cables for treatment of Vancouver type B2 periprosthetic femoral fractures, both the "reduce-first" and "ream-first" techniques showed adequate stem and fracture stability.

The Length of Diaphyseal Contact of Tapered Fluted Stems is Highly Dependent on Canal Morphology.

BACKGROUND: Diaphyseal fixation remains the mainstay of revision THA. The stability of diaphyseal fixation can be quantified by the extent of contact between the stem and the endosteal cortex. This is highly affected by the morphology of the proximal femur. The purpose of this study was to examine factors affecting diaphyseal contact in the revision THA and to identify preoperative predictors of adequate fixation. METHODS: Three-dimensional femur models were created from CT scans of 33 Dorr B and C femora. The proximal 120 mm of the femur was omitted to mimic proximal bone deficiency. A tapered fluted stem (3 degrees, 150 mm) model was virtually implanted after reaming of the medullary canal. The contact length between stem and endosteal cortex was measured, in addition to other variables. The relationship between variables was evaluated using Spearman's correlation, and logistic regression analysis was used to identify predictors of the contact length (P < .05). RESULTS: The contact length varied widely between specimens (66.5 ± 16.6 mm, range: 21-98 mm). Contact increased with the depth of the isthmus below the lesser trochanter (range: 55-155 mm; r2 = 0.473, P = .005) and the distance between the isthmus and the distal edge of the damage zone (range: -9 to 96 mm; r2 = 0.508, P = .002). Stepwise regression identified the reaming length, distance between fracture and the isthmus, and isthmus diameter as independent predictors of contact length (r = 0.643). CONCLUSIONS: Contact is limited in specimens where the isthmus is more proximally located. In these cases, supplementary fixation using plating and/or longer, curved prosthesis may be considered.

Contemporary Robotic Systems in Total Knee Arthroplasty: A Review of Accuracy and Outcomes.

The success of total knee arthroplasty (TKA) depends on restoration of the stability and biomechanical efficiency of the native knee. The emergence of robotic surgical technologies has greatly increased the precision and reproducibility. We discuss contemporary robotic TKA systems by reviewing the features of the individual platforms, their accuracy, and the clinical outcomes. While early results suggest significant gains in patient outcomes, long-term evidence is still awaited from multicenter prospective clinical trials. Moreover, advances in this technology are needed to address knee laxity while individualizing the functional performance of each patient's new joint.

Implementation of Preoperative Screening Criteria Lowers Infection and Complication Rates Following Elective Total Hip Arthroplasty and Total Knee Arthroplasty in a Veteran Population.

BACKGROUND: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common procedures with a risk of complications. Attempting to minimize complications, our institution implemented preoperative screening criteria for patients undergoing elective total joint replacement. Our study aimed to determine if screening criteria lowered total complications and/or surgical site infections (SSI). METHODS: Two groups of consecutive patients undergoing TKA and THA at a single Veterans Affairs facility were evaluated prior to and after implementation of screening criteria, 520 and 475 respectively. Screening criteria included hemoglobin A1c ≤7, hemoglobin ≥11, body mass index ≤35, and albumin ≥3.5. Groups were analyzed for demographics, preoperative comorbidities, and postoperative complications. Rates of total complications and SSI were compared. Average follow-up was at least 2 years with minimum of 1 year. RESULTS: Demographics and comorbidities outside the screening criteria were similar. Total complication rate was reduced from 35.4% to 14.8% (P < .01) after implementation of screening criteria. For TKA, total complications were reduced from 33.1% to 15.0% (P < .01) and for THA they were reduced from 42.4% to 14.2% (P < .01). SSI rates for combined TKA and THA were reduced from 4.4% to 1.3% (P < .01). For knees, SSI was reduced from 4.6% to 1.3% (P = .01) and was statistically significant. For THA, SSI decreased from 3.8% to 1.2% (P < .05). CONCLUSION: Our institution saw a statistically significant decrease in both SSI and total complications following implementation of preoperative screening criteria for elective TKA and THA.

Radial Head Ingrowth Anatomic Implant Versus Smooth Stem Monoblock Implant in Acute Terrible Triad Injury: A Prospective Comparative Study.

OBJECTIVE: This study aimed to compare clinical outcomes and radiographic findings between patients who received 2 different implants (smooth-stemmed modular implant or an anatomic press-fit implant) on patients with acute terrible triad injuries. DESIGN: Prospective cohort. SETTING: Level II Trauma center, University hospital. PATIENTS/PARTICIPANTS: Thirty-four patients with an isolated terrible triad injury were divided into 2 study groups (n = 17 each) with different sets of radial head implants and followed for 2 years. A total of 14 patients in each group (n = 28) completed the study. INTERVENTION: Group 1 received a smooth-stemmed round modular monopolar implant. Group 2 received an in-growth modular monopolar press-fit anatomic implant. MAIN OUTCOME MEASUREMENTS: Clinical outcomes were evaluated using the Visual Analog Scale, Mayo Index, and Disabilities of the Arm, Shoulder, and Hand (DASH) survey. Radiographs were evaluated for ectopic bone formation and loosening. RESULTS: No difference in clinical outcome when comparing range of motion and functionally scores between groups. Ectopic bone formation occurred equally with implants. Bone formation at the proximal radius under the implant occurred more in group 1 (85.7%), (P = 0.046). Five press-fit stems had radiolucent lines at 2-year follow-up. Two were removed because of symptomatic loosening. CONCLUSIONS: Short-term outcomes for both implants showed to be equally effective treatment options. The in vitro biomechanical advantages of anatomic implants do not translate into short-term improved outcomes. Symptomatic aseptic loosening in anatomic implants is common. Bone formation at the proximal radial neck was observed more with smooth-stemmed implants; further studies should assess this findings and clinical implication. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

A TRAUMATIC BILATERAL FEMORAL NECK FRACTURES IN A HEALTHY PREMENOPAUSAL FEMALE WITH HYPOVITAMINOSIS D.

Bilateral atraumatic femur neck fractures in young adult are very rare. We report a young premenopausal female with osteormalacia secondary to vitamin D deficiency and spontaneous bilateral femur neck fractures. Patient had no reported risk factors for osteomalacia but hypovitaminosis D was noted upon evaluation. Osteomalacia secondary to low serum levels of vitamin D may lead to stress and fragility fractures. Identification and treatment of such patients may decrease the incidence of stress fractures and- possible complications.