Faculty Bibliography

Background: Current literature does not provide conclusive evidence on whether routine pathologic examination of femoral heads from total hip arthroplasty is indicated or cost-effective. As a result, there is substantial variation in opinion among surgeons related to this issue. Our study aim was to determine factors that impact surgeon propensity to order pathologic examination of femoral heads. Methods: A 12-question survey was created to evaluate surgeon practices, indications, and patient care implications surrounding routine pathologic examination of femoral heads. The email survey was distributed to all members of the American Association of Hip and Knee Surgeons (n = 2598). Results: There were 572 survey respondents. Out of all respondents, 28.4% always send femoral heads to pathology, and 27.6% reported an institutional requirement to do so. Of the 572 surgeons, 73.6% report femoral head pathology has never resulted in a change in patient disease course. Factors that increase the likelihood of surgeons ordering femoral head pathologic examination include institutional requirements, medicolegal concern, and prior experience with femoral head pathologic examination changing patients' disease course (P <.001). Cost concern decreases the likelihood of surgeons ordering femoral head pathologic examination (P =.0012). Conclusions: A minority of surgeons routinely send femoral heads from total hip arthroplasty for pathologic examination, mostly because of institutional requirement. The majority of surgeons feel that femoral head pathologic examination never changes patient management, although others have infrequently detected malignancy and infection. Institutional policy, concern for litigation, and prior experience with discordant pathologic diagnoses increase femoral head pathologic examinations, while cost concern decreases them.

Mucopolysaccharidosis encompasses multiple lysosomal storage disorders that are relevant to the orthopedic surgeon as they lead to disruption in bone and cartilage development. These patients may present with early-onset joint pain, including end-stage hip arthritis warranting total hip replacement. The altered hip anatomy in this disorder is of specific importance to the arthroplasty surgeon as it presents challenges when reconstructing the proximal femur and acetabulum and informs implant choice. We present a 17-year-old patient with end-stage bilateral hip arthritis who underwent staged bilateral total hip arthroplasty. We discuss technical considerations in surgical technique and the consequences of acetabular and femoral deformity on implant selection.

INTRODUCTION/BACKGROUND:Removal of primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA) from the inpatient-only (IPO) list has financial implications for both patients and institutions. The aim of this study was to evaluate and compare financial parameters between patients designated for inpatient versus outpatient total joint arthroplasty (TJA) surgery. METHODS:We reviewed all patients who underwent TKA or THA after these procedures were removed from the IPO list. Patients were stratified into cohorts based on inpatient or outpatient status, procedure type, and insurance type. This included 5,284 patients, of which 4,279 were designated inpatient while 1,005 were designated outpatient. Patient demographic, perioperative, and financial data including per patient revenues, total and direct costs, and contribution margins (CMs) were collected. Data were compared using t-tests and Chi-square tests. RESULTS:Among Medicare patients receiving THA, CM was 89.1% lower for the inpatient cohort when compared to outpatient (p<0.001), though there was no significant difference between cohorts for TKA (p=0.501). Among patients covered by Medicaid or Government-managed plans, CM was 120.8% higher for inpatients receiving THA (p<0.001) when compared to outpatients and 136.3% higher for inpatients receiving TKA (p<0.001). CONCLUSION/CONCLUSIONS:Our analyses showed that recent costs associated with inpatient stay inconsistently match or outpace additional revenue, causing CM to vary drastically depending on insurance and procedure type. For Medicare patients receiving THA, inpatient surgery is financially disincentivized leaving this vulnerable patient population at risk of losing access to care.

AIM/OBJECTIVE:Posterior stabilized (PS) and varus valgus constrained (VVC) knee polyethylene liners have been shown to confer excellent long-term functional results following revision total knee arthroplasty (rTKA). The purpose of this study was to compare outcomes of patients who underwent rTKA using either a PS or VVC liner. METHODS:A retrospective comparative study of 314 rTKA with either PS or VVC liner and a minimum follow-up time of two years was conducted. Patient demographics, complications, readmissions, and re-revision etiology and rates were compared between groups. Kaplan-Meier survivorship analysis was performed to estimate freedom from all-cause revision. RESULTS:Hospital LOS (3.41 ± 2.49 vs. 3.34 ± 1.93 days, p = 0.793) and discharge disposition (p = 0.418) did not significantly differ between groups. At a mean follow-up of 3.55 ± 1.60 years, the proportion of patients undergoing re-revision did not significantly differ (19.1% vs. 18.7%, p = 0.929). In subgroup analysis of re-revision causes, the VVC cohort had superior survival from re-revision due to instability compared to the PS cohort (97.8% vs. 89.4%, p = 0.003). Freedom from re-revision due to aseptic loosening did not significantly differ between groups (85.2% vs. 78.8%, p = 0.436). Improvements in range of motion (ROM) from preoperative to latest follow-up were similar as well. CONCLUSIONS:PS and VVC liners confer similar survivorship, complication rates, and overall knee ROM in rTKA. VVC liners were not associated with increased postoperative aseptic loosening and demonstrated superior freedom from re-revision due to instability. Future studies with longer follow-up are warranted to better determine significant differences in clinical outcomes between the two bearing options. LEVEL III EVIDENCE/METHODS:Retrospective Cohort Study.

INTRODUCTION/BACKGROUND:The effect of vaping on outcomes after total joint arthroplasty (TJA) and its prevalence in this patient population remain unclear. The purpose of this study was twofold: (1) to investigate the trends of vaping in TJA patients compared with patients who underwent routine physical examination and (2) to examine the influence vaping has on outcomes after TJA. METHODS:Patients were classified as never vaped, former vape users, or whether they reported current vaping (CV). TJA patients were further classified based on whether they had no exposure to tobacco or vaping (NTNV), tobacco only (TO), both tobacco and vaping (BTV), or vaping only (VO). RESULTS:The TJA group exhibited a steady trend of patients with CV status (P = 0.540) while patients in the routine physical examination cohort demonstrated a significant upward trend in CV status (P = 0.015). Subanalysis of TJA patients revealed that those in the VO category had significantly higher mean surgical time (P < 0.001), length of stay (P = 0.01), and rates of readmission (P = 0.001) compared with all other subgroups. CONCLUSION/CONCLUSIONS:We found steady or increasing trends of electronic cigarette exposure in both groups over time. Additional efforts should be made to document electronic cigarette exposure for all patients.

Tourniquet use creates a reduced blood surgical field during total knee arthroplasty (TKA), however, prolonged ischemia may cause postoperative tourniquet complications. To understand the effects of tourniquet-induced ischemia, we performed a prospective observational study using quantitative broadband diffuse optical spectroscopy (DOS) to measure tissue hemodynamics and water and lipid concentrations before, during, and after tourniquet placement in subjects undergoing TKA. Data was collected for 6 months and, of the total subjects analyzed (n = 24), 22 were primary TKAs and 2 were revision TKA cases. We specifically investigated tourniquet-induced hemodynamics based upon subject-specific tissue composition and observed a significant relationship between the linear rate of deoxygenation after tourniquet inflation and water/lipid ratio (W/L, p < 0.0001) and baseline somatic tissue oxygen saturation, StO₂ (p = 0.05). Subjects with a low W/L ratio exhibited a lower tissue metabolic rate of oxygen consumption, (tMRO₂ ) (p = 0.008). Changes in deoxyhemoglobin [HbR] (p = 0.009) and lipid fraction (p = 0.001) were significantly different between high and low W/L subject groups during deoxygenation. No significant differences were observed for hemodynamics during reperfusion and total tourniquet time was neither significantly related to the hemodynamic hyperemic response (p = 0.73) nor the time to max StO₂ after tourniquet release (p = 0.57). In conclusion, we demonstrate that DOS is capable of real-time monitoring of tissue hemodynamics distal to the tourniquet during TKA, and that tissue composition should be considered. DOS may help surgeons stratify hemodynamics based upon tissue composition and eventually aid the preoperative risk assessment of vascular occlusions from tourniquet use during TKA.

INTRODUCTION/BACKGROUND:Bicruciate retaining (BCR) total knee arthroplasty (TKA) was designed to simulate natural knee kinematics and improve proprioception by retaining both the ACL and PCL. While the prospect of the design appears favorable to patients, previous designs have demonstrated modest survivorship rates compared to traditional designs. This study aims to report the early functional outcomes and implant survivorship of a novel BCR design. MATERIALS AND METHODS/METHODS:A multi-center, retrospective study was conducted identifying BCR TKA patients from 2016 to 2017. Patient demographics, quality outcomes, and post-operative complications were collected. A Kaplan-Meier analysis was used to evaluate revision-free survival. RESULTS:), predominantly white (71.4%), and female (69.9%). The device was most often implanted using standard instruments (85.7%) compared to computer-assisted navigation (13.5%). Average length-of-stay was 1.77 ± 0.97 days. Six patients had a reoperation; three (2.5%) full revisions occurred for: infection (n = 1), arthrofibrosis (n = 1), and ACL rupture (n = 1); one (0.8%) tibial revision occurred for: arthrofibrosis; two (1.5%) liner exchanges occurred for: infection (n = 1) and arthrofibrosis (n = 1). Kaplan-Meier survivorship analysis of cumulative failure at 2-year showed a survival rate of 96.2% (95% confidence interval, 91.2-98.4%) for all-cause reoperation, 97.3% (91.6-99.1%) for aseptic revision, and 100% for mechanical failure. CONCLUSION/CONCLUSIONS:Survivorship was 96.2% for all-cause reoperation, 97.3% for aseptic revision, and 100% for mechanical implant failure at 2-years. This novel BCR TKA demonstrated no implant-related complications and excellent survivorship outcomes over 2 years with comparable revision rates to those previously reported in the literature.

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.

Accurate and reproducible acetabular component positioning is among the most important technical factors affecting outcomes of total hip arthroplasty. Although several studies have investigated the influence of pelvic tilt and obliquity on functional acetabular anteversion, the effect of pelvic axial rotation has not yet been established. We analyzed a generic simulated pelvis created using preoperative full-body standing and sitting radiographs. A virtual acetabulum was placed in 144 different scenarios of acetabular anteversion and abduction angles. In each scenario, the effects of pelvic tilt and pelvic axial rotation on different combinations of acetabular orientations were assessed. The change in acetabular anteversion was 0.75° for each 1° of pelvic tilt and was most linear in abduction angles of 40°±45°. The change in acetabular anteversion was 0.8° for each 1° of pelvic axial rotation. Surgeons may consider adjusting acetabular anteversion in fixed axial pelvic deformities when the degree of deformity affects functional acetabular positioning, assessed from preoperative standing and sitting weight-bearing radiographs. [Orthopedics. 2023;46(1):e27-e30.].

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.