Faculty Bibliography

PURPOSE/OBJECTIVE:Navigated total knee arthroplasty (TKA) improves implant alignment by providing feedback on resection parameters based on femoral and tibial cutting guide positions. However, saw blade thickness, deflection, and cutting guide motion may lead to final bone cuts differing from planned resections, potentially contributing to suboptimal component alignment. We used an imageless navigation device to intraoperatively quantify the magnitude of error between planned and actual resections, hypothesizing final bone cuts will differ from planned alignment. MATERIALS AND METHODS/METHODS:A retrospective study including 60 consecutive patients undergoing primary TKA using a novel imageless navigation device was conducted. Device measurements of resection parameters were obtained via attachment of optical trackers to femoral and tibial cutting guides prior to resection. Following resection, optical trackers were placed directly on the bone cut surface and measurements were recorded. Cutting guide and bone resection measurements of both femoral and tibial varus/valgus, femoral flexion, tibial slope angles, and both femoral and tibial medial and lateral resection depths were compared using a Student's t-test. RESULTS:Femoral cutting guide position differed from the actual cut by an average 0.6 ± 0.5° (p = 0.85) in the varus/valgus angle and 1.0 ± 1.0° (p = 0.003) in the flexion/extension angle. The difference between planned and actual cut measurements for medial and lateral femoral resection depth was 1.1 ± 1.1 mm (p = 0.32) and 1.2 ± 1.0 mm (p = 0.067), respectively. Planned cut measurements based on tibial guide position differed from the actual cut by an average of 0.9 ± 0.8° (p = 0.63) in the varus/valgus angle and 1.1 ± 1.0° (p = 0.95) in slope angle. Measurement of medial and lateral tibial resection depth differed by an average of 0.1 ± 1.8 mm (p = 0.78) and 0.2 ± 2.1 mm (p = 0.85), respectively. CONCLUSIONS:Significant discrepancies between planned and actual femoral bone resection were demonstrated for flexion/extension angle, likely the result of cutting error. Our data highlights the importance of cut verification postresection to confirm planned resections are achieved, and suggests imageless navigation may be a source of feedback that would allow surgeons to intraoperatively adjust resections to achieve optimal implant alignment.

AIMS/OBJECTIVE:As our population ages, the number of octogenarians who will require a total hip arthroplasty (THA) rises. In a value-based system where operative outcomes are linked to hospital payments, it is necessary to assess the outcomes in this population. The purpose of this study was to compare outcomes of elective, primary THA in patients ≥ 80 years old to those aged < 80. METHODS:A retrospective review of 10,251 consecutive THA cases from 2011 to 2019 was conducted. Patient-reported outcome (PRO) scores (Hip disability and Osteoarthritis Outcome Score (HOOS)), as well as demographic, readmission, and complication data, were collected. RESULTS:= 0.57; p = 0.048). There were no observed differences in 12-week (p = 0.518) or one-year (p = 0.511) HOOS scores. CONCLUSION/CONCLUSIONS: 2021;2(7):535-539.

BACKGROUND:Intraoperative tourniquet use in total knee arthroplasty (TKA) is a common practice which may improve visualization of the surgical field and reduce blood loss. However, the safety and efficacy associated with tourniquet use continues to be a subject of debate among orthopedic surgeons. The primary purpose of this study is to evaluate the effects of tourniquet use on pain and opioid consumption after TKA. METHODS:This is a multicenter randomized controlled trial among patients undergoing TKA. Patients were preoperatively randomized to undergo TKA with or without the use of an intraoperative tourniquet. Frequency distributions, means, and standard deviations were used to describe baseline patient demographics (age, gender, race, body mass index, smoking status), length of stay, surgical factors, visual analog scale pain scores, and opioid consumption in morphine milligram equivalents. RESULTS:A total of 327 patients were included in this study, with 166 patients undergoing TKA without a tourniquet and 161 patients with a tourniquet. A statistically significant difference was found in surgical time (97.87 vs 92.98 minutes; P = .05), whereas none was found for length of stay (1.73 vs 1.70 days; P = .87), postop visual analog scale pain scores (1.73 vs 1.70; P = .87), inpatient opioid consumption (19.84 vs 19.27 morphine milligram equivalents; P = .74), or outpatient opioid consumption between the tourniquet-less and tourniquet cohorts, respectively. There were no readmissions in either cohort during the 90-day episode of care. CONCLUSION/CONCLUSIONS:Utilization of a tourniquet during TKA has minimal impact on postoperative pain scores and opioid consumption when compared with patients who underwent TKA without a tourniquet.

INTRODUCTION/BACKGROUND:There is debate regarding whether the use of computer-assisted technology, such as navigation and robotics, has any benefit on outcomes or patient-reported outcome measures (PROMs) following total knee arthroplasty (TKA). This study aims to report on the association between intraoperative use of technology and outcomes in patients who underwent primary TKA. METHODS:We retrospectively reviewed 7096 patients who underwent primary TKA from 2016-2020. Patients were stratified depending on the technology utilized: navigation, robotics, or no technology. Patient demographics, clinical data, Forgotten Joint Score-12 (FJS), and Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) were collected at various time points up to 1-year follow-up. Demographic differences were assessed with chi-square and ANOVA. Clinical data and PROMs were compared using univariate ANCOVA, controlling for demographic differences. RESULTS:A total of 287(4%) navigation, 367(5%) robotics, and 6442(91%) manual cases were included. Surgical-time significantly differed between the three groups (113.33 vs 117.44 vs 102.11; P < .001). Discharge disposition significantly differed between the three groups (P < .001), with more manual TKA patients discharged to a skilled nursing facility (12% vs 8% vs 15%; P < .001) than those who had technology utilized. FJS scores did not statistically differ at three-months (P = .067) and one-year (P = .221). We found significant statistical differences in three-month KOOS, JR scores (59.48 vs 60.10 vs 63.64; P = .001); however, one-year scores did not statistically differ between all groups (P = .320). CONCLUSION/CONCLUSIONS:This study demonstrates shorter operative-time in cases with no utilization of technology and clinically similar PROMs associated with TKAs performed between all modalities. While the use of technology may aid surgeons, it has not currently translated to better short-term outcomes. LEVEL III EVIDENCE/UNASSIGNED:Retrospective Cohort.

INTRODUCTION/BACKGROUND:Longevity and success of total hip arthroplasty (THA) is largely dependent on component positioning. While use of robotic platforms can improve this positioning, published evidence on its clinical benefits is limited. Therefore, the aim of this study was to assess the clinical outcomes of THA with robotic surgical assistance. MATERIALS AND METHODS/METHODS:We conducted an analysis of robotic arm-assisted primary THAs performed by a single surgeon utilizing a posterior approach. A total of 99 patients (107 cases) who had a minimum two-year follow up were identified. Their mean age was 61 years (range, 33 to 84 years), and their mean body mass index was 30.5 kg/m2 (range, 18.5 to 49.1 kg/m2). There were 56% female patients and primary osteoarthritis was the principal hip diagnosis in 88.8%. Operative times, lengths of hospital stay, and discharge dispositions were recorded, along with any complications. Modified Harris Hip Scores (HHS) were calculated to quantify clinical outcomes. RESULTS:Mean postoperative increases in HHS at 2- to 5.7-year follow up was 33 points (range, 6 to 77 points). There were no complications attributable to the use of robotic assistance. Surgical-site complications were rare; one case underwent a revision for prosthetic joint infection (0.93%) but there were no dislocations, periprosthetic fractures, or cases of mechanical implant loosening. There was no evidence of progressive radiolucencies or radiographic failure. DISCUSSION/CONCLUSIONS:Robotic arm-assisted THA resulted in low complication rates at minimum two-year follow up, with clinical outcomes comparable to those reported with manual surgery.1-4 The haptically-guided acetabular bone preparation enabled reliable cementless acetabular fixation and there were no adverse events related to the use of the robot. Dislocations were avoided in this case series. Randomized controlled clinical trials are needed to compare manual to robotic surgery and to investigate whether the precision found with this functional planning will reliably reduce the incidence of dislocations.

The purpose of this study was to investigate whether preoperative opioid use had any effect on clinical outcomes and patient-reported outcome measures (PROMs) before and after primary, elective total hip arthroplasty (THA). The authors retrospectively reviewed 793 patients who underwent primary THA from November 2018 to March 2020 with available PROMs. Patients were stratified into two groups based on whether or not they were taking opioids preoperatively. Demographics, clinical data, and PROMs (Forgotten Joint Score-12 [FJS-12], Hip disability and Osteoarthritis Outcome Score for Joint Replacement [HOOS, JR], and Veterans RAND 12 [VR-12] Physical Component Score [PCS] and Mental Component Score [MCS]) were collected at various time periods. Demographic differences were assessed with chi-square and independent sample t tests. Clinical data and PROMs were compared using multilinear regressions. Seventy-five (10%) patients were preoperative opioid users and 718 (90%) were not. Preoperative opioid users had a longer stay (1.37 vs 1.07 days; P=.030), a longer surgical time (102.44 vs 90.20 minutes; P=.001), and higher all-cause postoperative emergency department visits (6.7% vs 2.1%; P=.033) compared with patients not taking opioids preoperatively. Preoperative HOOS, JR (46.63 vs 51.26; P=.009), VR-12 PCS (27.79 vs 31.53; P<.001), and VR-12 MCS (46.24 vs 49.33; P=.044) were significantly lower for preoperative opioid users, but 3-month and 1-year postoperative scores were not statistically different. At 3 months and 1 year, FJS-12 scores did not differ significantly. Mean improvement preoperatively to 1 year in HOOS, JR values exceeded the minimal clinically important difference, with preoperative opioid users experiencing a greater improvement (36.50 vs 33.11; P=.008). Preoperative opioid users had a longer stay, a longer surgical time, and higher all-cause emergency department visits compared with preoperatively opioid naïve patients. Although preoperative opioid users reported significantly lower preoperative PROMs, they did not statistically differ postoperatively, which indicates a larger delta improvement and similar benefits following THA. [Orthopedics. 2021;44(2):77-84.].

Introduction/UNASSIGNED:Improper cup positioning and leg length discrepancy (LLD) are two of the most common errors following total hip arthroplasty (THA) and are associated with potentially significant consequences. Obesity is associated with increased risk of mechanical complications, including dislocations, which may be secondary to cup malposition and failure to restore leg length and offset. 3D Optical Camera computerassisted navigation (CAN) system may reduce the risk of component malposition and LLD with real time intraoperative feedback. The aim of this study was to investigate whether the use of CAN influences acetabular component placement (CP) accuracy and leg length restoration in obese (body mass index(BMI)≥35kg/m 2 ) patients undergoing primary THA. Methods/UNASSIGNED:A multi-center retrospective review was conducted identifying consecutive THA cases with BMI > 35kg/m 2 using CAN (Intellijoint Hip, Waterloo, CA) from 2015-2019. These patients were then matched with patients undergoing conventional THA (control) at a 1:1 ratio according to BMI, American Society of Anesthesiologists score, and gender. TraumaCad™ software (Brainlab, Chicago, IL) was used to measure cup anteversion, inclination, and change (Δ) in LLD between pre- and postoperative radiographic images. The safety target zones used as reference for precision analysis of CP were 15°-30° for anteversion and 30°-50° for inclination. Results/UNASSIGNED:176 patients were included: 88 CAN and 88 control cases. CAN cases were found to have a lower ΔLLD than controls (3.53±2.12mm vs. 5.00±4.05mm; p=0.003). Additionally, more CAN cases fell within the target safe zone than controls (83% vs.60%, p=0.00083). Conclusion/UNASSIGNED:Our findings suggest that the use of a CAN system may be more precise in component placement, and useful in facilitating the successful restoration of preoperative leg length following THA than conventional methodology.

Introduction/UNASSIGNED:Performing total hip arthroplasty (THA) for femoral neck fracture in the setting of a pre-existing intramedullary nail can be technically challenging, particularly if nail extraction is not feasible. Case Report/UNASSIGNED:A 76-year-old male presented with a with a displaced femoral neck fracture in the setting of a previously placed antegrade intramedullary nail with a healed femoral shaft fracture. After failed nail extraction, a novel technique was used to remove the proximal portion of the nail to allow for hybrid THA with implantation of a cemented femoral stem. Conclusion/UNASSIGNED:This is the first reported surgical technique of using a cortical window technique for partial intramedullary nail resection and cemented stem implantation in the setting of challenging intramedullary femoral nail extraction.