Ultrasound-Guided Adductor Canal Block Versus Intraoperative Transarticular Saphenous Nerve Block: A Retrospective Analysis.

BACKGROUND: The ultrasound-guided adductor canal block (High-ACB) is an effective option for pain control in total knee arthroplasty (TKA), but its use can add substantial cost and preparatory time to a TKA procedure. An intraoperative adductor canal block (Low-ACB) performed by the operative surgeon has been described as an alternative. The hypothesis of this study is that the Low-ACB would achieve noninferior pain control and opioid utilization postoperatively when compared to the High-ACB. METHODS: This is a retrospective study of a prospectively maintained database comparing the High-ACB vs the Low-ACB. The primary outcome measure was morphine milligram equivalents consumed. Secondary outcome measures included Visual Analog Scale pain scores, postoperative outcomes (Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, knee range of motion), length of stay, postoperative speed of mobilization, and complications related to the type of block. RESULTS: There were 139 patients in the study. There was lower opioid use in the first 24 hours in the Low-ACB compared to the High-ACB group respectively (26.3 vs 30, P = .29) but this did not reach statistical significance. There was a statistically significant difference in Visual Analog Scale score on postoperative day 1 in the Low-ACB vs High-ACB groups respectively (4.6 vs 3.7, P = .02) but this did not reach the level of clinical significance. There was no statistical difference in the Patient-Reported Outcome Measurement Information System, Knee Injury and Osteoarthritis Outcome Score, or postoperative range of motion. There were no block-related complications in either group. CONCLUSION: The Low-ACB is a safe, effective, and cost-saving alternative to the traditional High-ACB for pain control in TKA.

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

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.

Effect of Tibial Slope on Coronal Alignment in Total Knee Arthroplasty.

Malalignment of total knee arthroplasty (TKA) components affects function and survivorship. Common practice is to set coronal alignment prior to adjusting slope. With improper jig placement, adjustment of the slope may alter coronal alignment. The purpose of this study was to quantify the change in coronal alignment with increasing posterior tibial slope while comparing two methods of jig fixation. A prospective consecutive series of 100 patients underwent TKA using computer navigation. Fifty patients had the extramedullary cutting jig secured proximally with one pin and 50 patients had the jig secured proximally with two pins. Coronal alignment (CA) was recorded with each increasing degree of posterior slope (PS) from 0 to 7 degrees. Mean CA and change in CA were compared between cohorts. Utilizing one pin, osteotomies drifted into varus with an average change in CA of 0.34 degrees per degree PS. At 4 degrees PS, patients started to have >3 degrees of varus with 12.0% having >3 degrees of varus at 7 degrees PS. Utilizing two pins, osteotomies drifted into valgus with an average change of 0.04 degrees in CA per degree PS. No patients in the two-pin cohort fell outside 3 degrees varus/valgus CA. CA was significantly different at all degrees of PS between the cohorts. Changes in PS influenced CA making verification of tibial cut intraoperative critical. Use of >1 pin and computer navigation were beneficial to prevent coronal plane malalignment. This relationship may explain why computer navigation has been shown to improve alignment as well as survivorship and outcomes in some patients, especially those <65 years.

Documented Penicillin Allergies Should Not Preclude Use of Preoperative Cefazolin in Hip and Knee Arthroplasty.

INTRODUCTION: Perioperative cefazolin administration for total joint arthroplasty is a first-line antibiotic recommended by the American Academy of Orthopaedic Surgeons (AAOS) guidelines for the prevention of periprosthetic joint infections (PJIs). We aim to analyze the clinical viability of giving patients with a documented penicillin allergy (PA) a perioperative full-strength cefazolin "test dose" under anesthesia. METHODS: This is a retrospective chart review of 2,451 total joint arthroplasties from a high-volume arthroplasty orthopaedic surgeon over a 5-year period from January 2013 through December 2017. This surgeon routinely gave patients with a documented PA a full-strength cefazolin test dose while under anesthesia instead of administrating a second-line antibiotic. The primary outcomes examined were allergic reaction and postoperative infection. RESULTS: Cefazolin was given to 87.1% of all patients (1,990) and 46.0% of patients with a PA (143). The total rate of allergic reactions among all patients was 0.5% (11). Only one patient with a documented PA who received cefazolin had an allergic reaction. The reaction was not severe and did not require any additional treatment. In patients who had no reported allergies and received cefazolin, 0.3% (6) had an allergic reaction. There was no statistically significant difference in the rate of allergic reaction when comparing patients with and without a PA (P = 0.95). Patients receiving cefazolin had an overall PJI rate of 2.9% (57) versus those patients receiving antibiotics other than cefazolin who sustained a 5.5% PJI rate (16), which was statistically significant (P = 0.02). CONCLUSION: This study found that utilization of a full-strength test dose of cefazolin in patients with a documented PA is a feasible, safe, and effective way of increasing the rate of cefazolin administration and thus mitigating the risk of PJIs.

The Off-Table Technique Increases Operating Room Efficiency in Direct Anterior Hip Replacement.

Background: When performing a total hip arthroplasty via the direct anterior approach (DAA), many orthopedic surgeons utilize an orthopedic traction table. This technique requires an expensive table, time for positioning, staff to operate the table, and time-consuming transitions when preparing the femur. Some surgeons advocate for an "off-table" technique to avoid these difficulties. In this paper, we compare operating room efficiency between on-table and off-table techniques. Material and methods: We retrospectively reviewed patients undergoing total hip arthroplasty by a single surgeon across the transition from on-table to off-table DAA technique. Three cohorts were defined; the last 40 on-table hips, the first 40 off-table hips, followed by the second 40 hips. Timestamps from the operative record were recorded to calculate setup, surgical, takedown, and total room time. Implant fixation, patient demographic data, comorbidities, and complications were recorded. Results: From cohort 1 to 2, there was a 7-minute (14.44%, P = .0002) improvement in setup time but no change in total room time. From cohort 2 to 3, there was an additional 7-minute (15.47%, P < .0001) improvement in setup time, 32-minute (25.88%, P < .0001) improvement in surgical time, and 40-minute (21.96%, P < .0001) improvement in total room time yielding cumulative changes from cohort 1 to 3 of 15 minutes (27.68%, P < .0001), 28 minutes (23.11%, P < .0001), and 43 minutes (23.37%, P < .0001), respectively. There was no correlation between height, weight, or body mass index and time at any interval. Conclusion: Conversion to an off-table DAA technique offers an improvement in operating room efficiency. This is seen in setup, operative, and total room time. Implementation could allow for an additional case each day.

Staged Total Hip Arthroplasty: A Novel Technique in Managing Native and Periprosthetic Acetabular Insufficiency.

BACKGROUND: There is no consensus on how to best address acetabular insufficiency. Several described techniques have a high rate of loosening and most rely on fixation to intact innominate bones. They also require extensive exposure and expensive implants. We present a novel technique for acetabular insufficiency management including discontinuity and a series with mean 6.5-year follow-up. MATERIAL AND METHODS: After exposure, a femoral neck osteotomy is made, or the femoral component is removed. Bone graft is reverse reamed into the defect, and a porous coated acetabular shell is implanted with screws for supplemental fixation. In 3-6 months, after defect healing, the femoral component is implanted. All staged total hip arthroplasties for pelvic discontinuity from 2010 to 2015 by a single provider with minimum 5-year follow-up were identified. Implant survivorship, Merle d'Aubinge, and visual analog scale scores as well as complications were recorded. RESULTS: Nine patients were identified with mean 80.8-month follow-up (62-129). Merle D'Aubinge scores improved from 5.6 (4-8) to 15.3 (14-18), and Visual analog scale scores improved from 7.2 (6-9) to 0.8 (0-2). All implants were retained, and all patients were ambulatory at the terminal follow-up. There were 2 greater trochanter fractures, one calcar fracture managed with cerclage, and one patient developed heterotopic ossification. CONCLUSION: Staged total hip arthroplasty can be used to address pelvic discontinuity with excellent short- to mid-term outcomes. This technique allows for a more limited exposure and the use of primary hip implants. Fixation is by ingrowth and does not rely on intact pelvic architecture.

Assessing the Weight-Bearing Surface in Dysplastic Acetabulae: The Sourcil Index.

BACKGROUND: Although a variety of standardized measurements have been described to evaluate acetabular dysplasia, no single measurement is without limitations. We describe the Sourcil Index (SI), a novel measure of the weight-bearing surface of the acetabulum on anteroposterior pelvis films. The SI is the angle formed by the medial and lateral margins of the sourcil and the center of rotation of the femoral head. METHODS: Anteroposterior pelvis radiographs of skeletally mature patients from 2015 were reviewed. Studies with fractures or implants were excluded. Films were read by 2 orthopedic surgeons and a radiologist 3 times each, 8 weeks apart. The SI, Sharp's Angle (SA), and lateral center edge angle (LCEA) were recorded. Pearson intraclass correlation coefficients with 95% confidence intervals were calculated. The SI was then compared to the SA and LCEA to preliminarily assess diagnostic accuracy. RESULTS: Five hundred thirty-five hips in 292 patients met inclusion. Intraobserver reliability is as follows: SI = 0.95 (0.93-0.98), LCEA = 0.89 (0.82 -0.96), and SA = 0.90 (0.85-0.96). Interobserver reliability is as follows: SI = 0.90 (0.84-0.94), SA = 0.78 (0.64-0.86), and LCEA = 0.73 (0.56-0.82). There were 51 dysplastic hips within this cohort. CONCLUSION: The SI is a reproducible measurement on plain radiographs. The SI is a two-dimensional representation of the size of the weight-bearing surface of the acetabulum and could provide an estimation of joint contact pressures. Used with existing measures, the SI may provide a more nuanced understanding of acetabular morphology.

Dislocation rates following total hip arthroplasty via the direct anterior approach in a consecutive, non-selective cohort.

AIMS: Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method. METHODS: We retrospectively reviewed all patients undergoing THA via the DAA between 2011 and 2017 at our institution. Primary outcome was dislocation at minimum two-year follow-up. Patients were stratified by demographic details and risk factors for dislocation, and an in-depth analysis of dislocations was performed. RESULTS: A total of 2,831 hips in 2,205 patients were included. Mean age was 64.9 years (24 to 96), mean BMI was 29.2 kg/m2 (15.1 to 53.8), and 1,595 patients (56.3%) were female. There were 11 dislocations within one year (0.38%) and 13 total dislocations at terminal follow-up (0.46%). Five dislocations required revision. The dislocation rate for surgeons who had completed their learning curve was 0.15% compared to 1.14% in those who had not. The cumulative periprosthetic infection and fracture rates were 0.53% and 0.67%, respectively. CONCLUSION: In a non-selective, consecutive cohort of patients undergoing THA via the DAA, the risk of dislocation is low, even among patients with risk factors for instability. Our data further suggest that the DAA can be safely used in all hip arthroplasty patients without an increased risk of wound complications, fracture, infection, or revision. The inclusion of seven surgeons increases the generalizability of these results. Cite this article: Bone Joint J 2021;103-B(7 Supple B):38-45.

Morphology of the Greater Trochanter: An Assessment of Anatomic Variation and Canal Overhang.

BACKGROUND: Varus malposition is a risk of early failure in total hip arthroplasty. The degree to which the tip of the greater trochanter (GT) overhangs the canal can increase this risk. Although we know proximal femoral anatomy is variable, no study has addressed variations in medial overhang of the GT on plain radiographs. METHODS: All low anteroposterior pelvis radiographs more than 1 year were reviewed 3 times by 2 orthopaedic surgeons and one radiologist. The canal width (CW) was measured 10 cm below the lesser trochanter. Canal overhang (CO) was defined by the distance between the lateral medullary canal and a parallel line beginning at the most medial aspect of the GT. The overhang index (OI) is defined as the percentage of the canal overhung by the GT. RESULTS: The mean CW was 13.5 mm, mean CO 16.4 mm, and mean OI 1.22. Hips were then classified as the following: (A) OI < 0.5 (n = 8), (B) OI 0.5-1.0 (n = 78), (C) OI 1.0-1.5 (n = 191), and (D) OI > 1.5 (n = 68). Intraobserver reliability was excellent for all measures: 0.89 (confidence interval: 0.87-0.91) for CW, 0.96 (0.95-0.97) for CO, and 0.97 (0.97-0.98) for OI. Interobserver reliability was good for CW 0.75 (0.70-0.79) and excellent for CO 0.90 (0.88-0.92) and OI 0.95 (0.94-0.96). CONCLUSIONS: Variations in the morphology of the proximal femur can predispose to varus component malposition. The degree to which the GT overhangs the canal can be quantified and classified based on plain films. This can aid in preoperative planning and help guide intraoperative proximal femoral preparation.