Faculty Bibliography

INTRODUCTION/BACKGROUND:The direct anterior approach (DAA) has become increasingly more popular for total hip arthroplasty (THA). Critics of the DAA maintain that a higher complication rate exists; however, data collection is prone to bias as the outcome is collected by the surgeons performing either an anterior or posterior approach (PA). This study aims to compare the short-term outcomes, including complication rates, in a Medicare population between THAs performed via DAA and PA. MATERIALS AND METHODS/METHODS:Baseline patient data was obtained from our institution's database for bundled payments, an unbiased collection source. A retrospective chart review was conducted on 492 Medicare patients who underwent primary THA between October 2016 and September 2017 to separate patients into DAA and PA cohorts. Descriptive patient characteristics along with surgical and clinical data were collected. Statistical tests for significance were based on either t-tests or chi-squared. To control for demographic variables, a multivariable regression analysis was conducted. RESULTS:Two hundred forty-one patients were included in the DAA cohort while 251 were included in the PA cohort. Surgical time (74.39 vs. 103.03 minutes; p < 0.001) and length-of-stay (1.29 vs. 2.74 days; p < 0.001) in patients who underwent the DAA was revealed to be statistically lower compared to the PA cohort. Patients in the DAA cohort were statistically more likely to be discharged to home health agencies (HHA) or self-care compared to those in the PA cohort (93.4% vs.74.5%; p < 0.001). There were no statistical differences in 90-day readmission rates or morphine milligram equivalents per day between both cohorts. CONCLUSION/CONCLUSIONS:The DAA to THA resulted in shorter surgical time, length-of-stay, and increased likelihood of discharge to HHA or self-care when compared with the PA. There were no differences in opioid consumption and complications leading to 90-day readmission.

BACKGROUND:Concerns have been voiced regarding how surgical approach impacts risk of dislocation after total hip arthroplasty (THA). This study investigated how surgical approach impacts rate, direction, and timing of dislocations following THA. METHODS:We conducted a retrospective review of 13,335 primary THAs from 2011 to 2020 and identified 118 patients with prosthetic hip dislocation. Patients were stratified into cohorts by surgical approach used during primary THA. Patient demographics, index THA acetabular cup positioning, number, direction, timing of dislocations, and subsequent revisions were collected. RESULTS:Dislocation rate differed significantly between posterior approach (PA), direct anterior approach (DAA), and laterally-based approach (LA) (1.1 versus 0.7% versus 0.5%, P = .026). Rate of hips dislocating anteriorly was lowest in the PA group (19.2%) compared to LA (50.0%) and DAA groups (38.2%, P = .044). There was no difference in rate of hips dislocating posteriorly (P = .159) or multidirectional (P = .508) instability; notably 58.8% of dislocations in the DAA cohort occurred posteriorly. There were no differences in dislocation timing or revision rate. Acetabular anteversion was highest in the PA cohort compared to DAA and LA (21.5 versus 19.2 versus 11.7 degrees, P = .049). CONCLUSION:After THA, patients in the PA group had a slightly higher dislocation rate compared to the DAA and LA groups. The PA group had a lower rate of anterior dislocation and nearly 60% of DAA dislocations occurred posteriorly. However, with no differences in other parameters including revision rates or timing, our data suggests surgical approach may impact dislocation characteristics to a lesser degree than previous studies have suggested.

BACKGROUND:The impact of morbid obesity (MO) on outcomes following total knee arthroplasty (TKA) when performed by high-volume (HV) surgeons has not been investigated. This study aimed to assess complication rates and implant survivorship in MO patients operated on by HV surgeons. METHODS:Patients undergoing primary, elective TKA between June 2011 and May 2022 with a HV surgeon (top 25% surgeons by the number of primary TKAs per year) were retrospectively reviewed. Patients were stratified by body mass index (BMI) into 3 groups: BMI ≥40 (MO), 30≤ BMI <40 (non-morbidly obese), and BMI <30 (nonobese) and 1:1:1 propensity matched based on baseline characteristics. Of the 12,132 patients evaluated, 1,158 were included in final matched analyses (386 per group). The HV surgeons performed a median of 104 TKAs annually (range, 90-173). RESULTS:The MO patients had significantly longer surgery duration (P = .006) and hospital lengths of stay (P < .001). The 90-day postoperative complications (P = .38) and readmission rates (P = .39) were comparable between groups. Rates of all-cause, septic and aseptic revision were similar between groups at two-year (P = .30, P = .15, and P = .26, respectively) and the latest follow-up (P = .36, P = .52, and P = .38, respectively). Improvement in Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) scores at 6 months (P = .049) and one year (P = .015) was significantly higher in MO patients. CONCLUSION/CONCLUSIONS:Clinical outcomes and complication rates following TKA by HV surgeons are comparable regardless of obesity status. The MO patients may benefit from referral to experienced surgeons to minimize procedural risks and improve outcomes. LEVEL OF EVIDENCE/METHODS:III.

INTRODUCTION/BACKGROUND:Cement burns following arthroplasty pro-cedures are a rare but serious complication. To the authors' knowledge, this report is the first of its kind in total knee arthroplasty. CASE/METHODS:A 61-year-old female underwent an otherwise rou-tine left total knee arthroplasty. On postoperative day one, a 3 cm by 3 cm cement burn was noted on the distal aspect of the popliteal fossa of the operative leg. The burn was noted to be a full-thickness (third degree) burn that required plastic surgery burn service management and limited the patient's postoperative recovery and function. CONCLUSIONS:Cement burns of the skin following total joint arthroplasty are rare, though when they do occur, they can cause significant pain and distress. Recognizing the depth of the skin involvement is important to determine the burn classification, treatment, and ultimately the prognosis to optimize outcomes.

BACKGROUND/UNASSIGNED:. Of the 38 patients, 1 (2.6%) experienced a postoperative dislocation that was subsequently treated with closed reduction without further dislocation. This surgical technique represents a favorable surgical option for patients with acetabular bone loss who are at risk for hip instability. In the example case described in the present video article, the patients had a history of dislocations, lumbar fusion, and evidence of Paprosky 3B acetabular defect; as such, the decision was made to revise to a porous shell and cement a monoblock dual-mobility implant. DESCRIPTION/UNASSIGNED:With use of the surgeon's preferred approach, the soft tissue is dissected and the hip is aspirated. The hip is dislocated and a subgluteal pocket is made with use of electrocautery to mobilize the trunnion of the femoral stem to aid in acetabular exposure. The femoral component is assessed to ensure appropriate positioning with adequate anteversion. The acetabular component and any acetabular screws are removed. A "ream to fit" technique is performed in the acetabulum until bleeding bone is encountered, with minimal reaming performed in healthy bone from the posterior column. A trial prosthesis is placed within the acetabulum to evaluate if there is satisfactory fixation and if any augment is necessary. Care must be taken during reaming to ensure that enough bone is reamed to accommodate a porous shell that can fit the monoblock dual-mobility implant with a 2-mm cement mantle. Smaller porous shells measuring 56 mm are available for smaller defects but are often not utilized in cases of substantial acetabular bone loss. Fresh-frozen cancellous allograft is utilized to fill any contained defects. The revision porous shell with circumferential screw holes is utilized to allow for screw fixation posterosuperior and anterior toward the pubis. The implants are dried prior to placement of the cement. The cement is applied to the shell and the monoblock dual-mobility implant to ensure adequate coverage. Antibiotic-loaded cement can be utilized according to surgeon preference. Excess cement is removed under direct visualization while the cement is drying, and the position of the dual-mobility implant is adjusted in approximately 20° anteversion and 40° inclination. Stability is assessed after the cement cures, and intraoperative radiography can be performed to confirm cup positioning prior to closure. Any remaining capsule is closed, followed by closure of the remaining soft tissue in a layered fashion. ALTERNATIVES/UNASSIGNED:A fully porous multi-hole jumbo cup with conventional polyethylene liner and femoral head can be utilized to increase the jump distance of the femoral head. Constrained, lipped, or offset polyethylene liners can be utilized if the shell is well fixed and a dual-mobility implant cannot be inserted. A cemented dual-mobility implant can be utilized in a well-fixed acetabular shell without evidence of loosening or osteolysis. RATIONALE/UNASSIGNED:. Moreover, acetabular cup survival was excellent, with 100% survival at 1 year and 96.2% at 2 years. EXPECTED OUTCOMES/UNASSIGNED:. IMPORTANT TIPS/UNASSIGNED:In order to allow for circumferential coverage for fixation and ingrowth potential in cases with acetabular defects, the shell is typically impacted slightly vertical (45° to 50° of inclination) and in neutral version (0° to 5° of anteversion). Positioning can be adjusted to improve osseous contact and ingrowth as determined by the size and shape of the defect.The use of a drill guide for the locking screws allows limited degrees of variable screw angulation. In the revision setting, longer screws may be placed posterosuperior toward the sciatic notch or anteroinferior into the pubis. Surgeons should be aware of the anatomy and should predrill holes to reduce the risk of injury to surrounding neurovascular structures such as the obturator artery anteriorly.Any screw holes that are not filled should be covered with plastic hole covers in order to prevent cement from migrating behind the cup. Implants should be dried prior to the placement of the cement, and the cement should be applied to the shell and the dual-mobility implant to ensure adequate coverage.Utilize a monoblock dual-mobility implant that is designed for cementation in order to avoid implant dissociation from the acetabular shell.Remove all fibrous tissue that may hinder bony integration.Assess for pelvis discontinuity; pelvis discontinuity and acetabular bone loss are risk factors in the setting of any revision and should be properly assessed preoperatively and intraoperatively and managed accordingly.Avoid over-reaming and damage of the posterior column.Utilize a reamer or trial to assess defect size and need for augments.Place a compression screw where the cup is in contact with the bone in order to avoid tilting.Cover unused screw holes. ACRONYMS AND ABBREVIATIONS/UNASSIGNED:THA = total hip arthroplastyS/P = status postTKA = total knee arthroplastyCT = computed tomographyKM = Kaplan MeierDMC = dual-mobility cupPE = polyethylene.

Non-English-speaking patients face increased communication barriers when undergoing total joint arthroplasty (TJA). Surgeons may learn or have proficiency in languages spoken among their patients to improve communication. This study investigated the effect of surgeon-patient language concordance on outcomes after TJA. We conducted a single-institution, retrospective review of patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) whose preferred language was not English. Patients were stratified based on whether their surgeon spoke their preferred language (language concordant [LC]) or not (language discordant [LD]). Baseline characteristics, length of stay, discharge disposition, revision rate, readmission rate, and patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score for Joint Replacement [KOOS, JR], Hip disability and Osteoarthritis Outcome Score for Joint Replacement [HOOS, JR], and Patient-Reported Outcomes Measurement Information System [PROMIS]) were compared. A total of 3390 patients met inclusion criteria, with 855 receiving THA and 2535 receiving TKA. Among patients receiving THA, 440 (51.5%) saw a LC provider and 415 (48.5%) saw a LD provider. Those in the LC group had higher HOOS, JR scores at 1 year postoperatively (67.4 vs 49.3, P=.003) and were more likely to be discharged home (77.5% vs 69.9%, P=.013). Among patients receiving TKA, 1051 (41.5%) received LC care, whereas 1484 (58.5%) received LD care. There were no differences in outcome between the LC and LD TKA groups. Patients receiving THA with surgeons who spoke their language had improved patient-reported outcomes and were more commonly discharged home after surgery. Language concordance did not change outcomes in TKA. Optimizing language concordance for patients receiving TJA may improve postoperative outcomes. [Orthopedics. 2023;46(6):334-339.].

PURPOSE/OBJECTIVE:Soft tissue balancing is an important step in a total knee procedure, carried out manually, or using an indicator. The purpose of this study was to evaluate our design of 3D printed Balancer, and demonstrate how it could be used at surgery. PROCEDURES/METHODS:When inserted between the femur and tibia, the Balancer displayed the forces acting across the lateral and medial compartments, indicated by pointers at the end of the handle. A loading rig was used to measure the pointer deflections for different forces applied at different locations on the condyle surfaces. Repeatability and reproducibilty were evaluated. The Balancer was tested in six fresh knee specimens using a surgical simulation rig. MAIN FINDINGS/RESULTS:Pointer deflections of up to 12 millimeters occurred for less than 1 mm displacements at the condyle surfaces. Reproducibility tests showed a standard deviation of 14% at lower loads, reducing to only 4% at higher loads. Mean pointer deflections were within 8% for forces applied at ±10 mm AP, and +5/-3 mm in an ML direction, relative to the neutral contact point. In specimens, most lateral to medial force differences could be corrected by a 2° change in frontal plane angle of the tibial resection. Effects of ligament releases were also demonstrated. PRINCIPAL CONCLUSIONS/CONCLUSIONS:The 3D printed Balancer was easy to use, and provided the surgeon with lateral and medial force data over a full range of flexion, enabling possible corrective procedures to be specified.

INTRODUCTION/UNASSIGNED:With the increasing demand for total knee arthroplasty (TKA) and the burden of revision TKA on the healthcare system, as well as the quality of life implications for patients, it is extremely important for surgeons to be able to anticipate and prevent TKA mechanical complications. Surgeons must be familiar with the different causes and mechanisms of TKA complications so that they can properly treat patients with failed TKAs and better avoid these complications. AREAS COVERED/UNASSIGNED:This review addresses TKA mechanical complications and provides context for the topic. A detailed review of surgical factors, implant factors, and patient factors that contribute to mechanical complications after TKA is provided. All of the literature cited in this review was gathered from the PubMed online database using different keywords based on the section of the manuscript. EXPERT OPINION/UNASSIGNED:As surgeons and engineers solve certain issues in TKA, new challenges will inevitably arise. We must continue to push forward and innovate from both a surgical technique and implant design perspective.

BACKGROUND:Removal of total knee arthroplasty (TKA) from the inpatient only list has led to a greater focus on outpatient (OP) procedures. However, the impact of OP-centered models in at-risk patients is unclear. Therefore, the current analysis investigated the effect of conversion from OP to inpatient (IP) status on postoperative outcomes and determined which factors put patients at risk for status change postoperatively. METHODS:We retrospectively reviewed all patients who underwent a primary TKA at our institution between January 2, 2018, and April 26, 2022. All patients included were originally scheduled for OP surgery and were separated based on conversion to IP status postoperatively. Multiple regression analyses were used to determine the significance of all perioperative variables. Modeling via binary logistic regressions was used to determine factors predictive of status conversion. RESULTS:Of the 2,313 patients originally designated for OP TKA, 627 (27.1%) required a stay of 2 midnights or longer. Patients in the IP group had significantly higher facility discharge rates (P < .001) compared to the OP group. Factors predictive of conversion included age of 65 years and older (P < .001), women (P < .001), arriving at the postanesthesia care unit after 12 pm (P < .001), body mass index greater than 30 (P = .004), and Charlson Comorbidity Index of 4 and higher (P = .004). Being the first case of the day (P < .001) and being married (P < .001) were both protective against conversion. CONCLUSION:Certain intrinsic patient factors may predispose a patient to an IP stay, and an understanding of predisposing factors which could lead to IP conversion may improve perioperative planning moving forward.

BACKGROUND/UNASSIGNED:Total knee arthroplasty (TKA) procedures are expected to grow exponentially in the upcoming years, highlighting the importance of identifying preoperative risk factors that predispose patients to poor outcomes. The present study sought to determine if preoperative healthcare events (PHEs) influenced outcomes following TKA. METHODS/UNASSIGNED:This was a retrospective review of all patients who underwent TKA at a single institution from June 2011 to April 2022. Patients who had a PHE within 90 days of surgery, defined as an emergency department visit or hospital admission, were compared to patients with no history of PHE. Patients who underwent revision, nonelective, and/or bilateral TKA were excluded. Chi-squared analysis and independent sample t-tests were used to determine significant differences between demographic variables. All significant covariates were included in binary logistic regressions used to predict discharge disposition, 90-day readmission, and 1-year revision. RESULTS/UNASSIGNED: = .004) compared to patients without a PHE. CONCLUSIONS/UNASSIGNED:Our results demonstrate that PHEs put patients at significantly greater risk of facility discharge, 90-day readmission, and 1-year revision. Moving forward, consideration of elective surgery scheduling in the context of a recent PHE may lead to improved postoperative outcomes. LEVEL III EVIDENCE/UNASSIGNED:Retrospective Cohort Study.