The James A. Rand Young Investigator's Award: Keeping It Simple: Are all Musculoskeletal Infection Society Tests Useful to Diagnose Periprosthetic Joint Infection?

BACKGROUND: Current data evaluating the clinical value and cost-effectiveness of advanced diagnostic tests for periprosthetic joint infection (PJI) diagnosis, including alpha-defensin and synovial C-reactive protein (CRP), is conflicting. This study aimed to evaluate the adequacy of preoperative and intraoperative PJI workups without utilizing these tests. METHODS: This retrospective analysis identified all patients who underwent revision total knee or hip arthroplasty (rTKA and rTHA, respectively) for suspected PJI between 2018 and 2020 and had a minimum follow-up of 2 years. Perioperative data and lab results were collected, and cases were dichotomized based on whether they met the 2018 Musculoskeletal Infection Society (MSIS) criteria for PJI. In total, 204 rTKA and 158 rTHA cases suspected of PJI were reviewed. RESULTS: Nearly 100% of the cases were categorized as "infected" for meeting the 2018 MSIS criteria without utilization of alpha-defensin or synovial CRP (rTKA: n = 193, 94.6%; rTHA: n = 156, 98.7%). Most cases were classified as PJI preoperatively by meeting either the major MSIS or the combinational minor MSIS criteria of traditional lab tests (rTKA: n = 177, 86.8%; rTHA: n = 143, 90.5%). A subset of cases was classified as PJI by meeting combinational preoperative and intraoperative MSIS criteria (rTKA: 16, 7.8%; rTHA: 13, 8.2%). Only 3.6% of all cases were considered "inconclusive" using preoperative and intraoperative data. CONCLUSIONS: Given the high rate of cases satisfying PJI criteria during preoperative workup using our available tests, the synovial alpha-defensin and synovial CRP tests may not be necessary in the routine diagnostic workup of PJI. We suggest that the primary PJI workup process should be based on a stepwise algorithmic approach with the most economical testing necessary to determine a diagnosis first. The use of advanced, commercialized, and costly biomarkers should be utilized only when traditional testing is indeterminate.

Indications, Clinical Outcomes, and Re-Revisions Following Revision Total Hip Arthroplasty - Does Age Matter?

BACKGROUND: Younger age is associated with increased revision incidence following primary total hip arthroplasty, though the association between age and repeat revision following revision total hip arthroplasty (rTHA) has not been described. This study aimed to describe the incidences and indications for subsequent revision (re-revision) following rTHA based on age. METHODS: Patients undergoing aseptic rTHA from 2011 to 2021 with minimum 1-year follow-up were retrospectively reviewed. Patients were stratified into 3 groups based on age at the time of index rTHA (ie, <55 years, 55 to 74 years, and >74 years). Perioperative characteristics, complications, and re-revisions were compared between groups. RESULTS: Of 694 included rTHAs, those in the >74 age group were more likely to undergo rTHA for periprosthetic fracture (P < .001) while those in the <55 age group were more likely to undergo rTHA for metallosis/taper corrosion (P = .028). Readmissions (P = .759) and emergency department visits (P = .498) within 90 days were comparable across ages. Rates of re-revision were comparable at 90 days (P = .495), 1 year (P = .443), and 2 years (P = .204). Kaplan-Meier analysis of all-cause re-revision at latest follow-up showed a nonstatistically significant trend toward increasing re-revisions in the <55 and 55 to 74 age groups. Using logistic regressions, smoking and index rTHA for instability were independently associated with re-revision, while age at index surgery was not. CONCLUSIONS: While indications for rTHA differ across age groups, rates of 2-year re-revision are statistically comparable between groups. Further studies are warranted to understand the association between age, activity, and re-revision rates after 5 years postoperatively.

Temporal, Seasonal, and Monthly Effects on Total Knee Arthroplasty Surgical Site Infection Rates.

BACKGROUND: Deep surgical site infections (dSSI) following total knee arthroplasty (TKA) are associated with morbidity and poor outcomes. Although numerous patient and non-patient factors have been correlated with dSSI development, the temporal and seasonal variability of dSSI is unclear. The purpose of this study was to investigate the monthly and seasonal variability of dSSI rates following TKA. METHODS: The dSSI database at a single large, urban, academic medical center was reviewed for TKAs performed between January 2009 and August 2018. The monthly and seasonal variability of dSSI was evaluated using a Poisson regression. Additionally, the change in dSSI rate was calculated over the entire study period. RESULTS: We reviewed 15,230 consecutive TKAs. The average dSSI rate following TKA was 1.11% (SD: 0.91). The rate of dSSI decreased over the study period (r = 0.94, 95% CI: 0.85-1.05) but did not reach statistical significance. With summer as the reference season, there were no significant differences in the dSSI rate in fall, winter, or spring. With July as the reference season, there were no differences in the dSSI rate in any other months of the year. CONCLUSION: Although non-significant, this analysis found a decreasing rate of dSSI after TKA over a nearly 10-year period. Interestingly, there was no difference in the dSSI rate following TKA in July as compared to other months or in summer as compared to other seasons. This conflicts with previous reports that have found an increased incidence of dSSI and other complications in July when the graduate medical education calendar begins.

Outcomes of medicaid patients undergoing TJA with previous positive urine toxicology screens.

INTRODUCTION: Previous studies have demonstrated that patients with positive preoperative urine toxicology (utox) screens prior to total joint arthroplasty (TJA) have higher readmission rates, greater complication rates, and longer hospital stays compared to patients with negative screens. The aim of this study was to investigate the effect of postponing surgery for patients with positive preoperative utox in the Medicaid population. METHODS: This retrospective, observational study reviewed the Medicaid ambulatory database at a large, academic orthopedic specialty hospital for patients with a utox screen prior to TJA from 2012 to 2020. Patients were categorized into three groups: (1) controls with negative preoperative utox or a utox consistent with prescription medications (Utox-) with TJA completed as scheduled; (2) positive preoperative utox with TJA rescheduled and surgery completed on a later date (R-utox+); (3) positive preoperative utox inconsistent with prescription medications with TJA completed as scheduled (S-utox+). Primary outcomes included mortality, 90-day readmission rate, complication rate, and length of stay. RESULTS: Of the 300 records reviewed, 185 did not meet inclusion criteria. The remaining 115 patients included 80 (69.6%) Utox-, 5 (6.3%) R-utox+, and 30 (37.5%) S-utox+. Mean follow-up time was 49.6 months. Hospital stays trended longer in the Utox- group (3.7 ± 2.0 days vs. 3.1 ± 1.6 S-utox+ vs.2.5 ± 0.4 R-utox+, p = 0.20). Compared to the R-utox+group, the S-utox+ group trended toward lower home discharge rates (p = 0.20), higher in-hospital complication rates (p = 0.85), and more all-cause 90-day emergency department visits (p = 0.57). There were no differences in postoperative opioid utilization between groups (p = 0.319). Duration of postoperative narcotic use trended toward being longer in the Utox- patients (820.7 ± 1073.8 days vs. 684.6 ± 1491.8 S-utox+ vs. 585.1 ± 948.3 R-utox+, p = 0.585). Surgical time (p = 0.045) and revision rates (p = 0.72) trended toward being higher in the S-utox+ group. CONCLUSIONS: Medicaid patients with positive preoperative utox who had surgeries postponed trended towards shorter hospital stays and greater home discharge rates. Larger studies should be conducted to analyze the implications of a positive preoperative utox on risk profiles and outcomes following TJA in the Medicaid population. Study design Retrospective cohort study.

Impact of time to revision total knee arthroplasty on outcomes following aseptic failure.

INTRODUCTION: Prior studies have demonstrated an association between time to revision total knee arthroplasty (rTKA) and indication; however, the impact of early versus late revision on post-operative outcomes has not been reported. MATERIALS AND METHODS: A retrospective, observational study examined patients who underwent unilateral, aseptic rTKA at an academic orthopedic hospital between 6/2011 and 4/2020 with > 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary TKA (pTKA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared. RESULTS: 470 rTKA were included (199 early, 271 late). Early rTKA patients were younger by 2.5 years (p = 0.002). The predominant indications for early rTKA were instability (28.6%) and arthrofibrosis/stiffness (26.6%), and the predominant indications for late rTKA were aseptic loosening (45.8%) and instability (26.2%; p < 0.001). Late rTKA had longer operative times (119.20 ± 51.94 vs. 103.93 ± 44.66 min; p < 0.001). There were no differences in rTKA type, disposition, hospital length of stay, all-cause 90-day emergency department visits and readmissions, reoperations, and number of re-revisions. CONCLUSIONS: Aseptic rTKA performed before 2 years had different indications but demonstrated similar outcomes to those performed later. Early revisions had shorter surgical times, which could be attributed to differences in rTKA indication. LEVEL OF EVIDENCE: III, retrospective observational analysis.

Multiply revised TKAs have worse outcomes compared to index revision TKAs.

Aims: Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised. Methods: This retrospective, observational study reviewed patients who underwent unilateral, aseptic rTKA at an academic orthopaedic speciality hospital between June 2011 and April 2020 with > one-year of follow-up. Patients were dichotomized based on whether this was their first revision procedure or not. Patient demographics, surgical factors, postoperative outcomes, and re-revision rates were compared between the groups. Results: A total of 663 cases were identified (486 index rTKAs and 177 multiply revised TKAs). There were no differences in demographics, rTKA type, or indication for revision. Multiply revised patients had significantly longer rTKA operative times (p < 0.001), and were more likely to be discharged to an acute rehabilitation centre (6.2% vs 4.5%) or skilled nursing facility (29.9% vs 17.5%; p = 0.003). Patients who had been multiply revised were also significantly more likely to have subsequent reoperation (18.1% vs 9.5%; p = 0.004) and re-revision (27.1% vs 18.1%; p = 0.013). The number of previous revisions did not correlate with the number of subsequent reoperations (r = 0.038; p = 0.670) or re-revisions (r = -0.102; p = 0.251). Conclusion: Multiply revised TKA had worse outcomes, with higher rates of facility discharge, longer operative times, and greater reoperation and re-revision rates compared to index rTKA.

Impact of revision TKA indications on resource utilization.

BACKGROUND: Indications for surgery may impact resource utilization in aseptic revision total knee arthroplasty (rTKA), and understanding these relationships would facilitate risk-stratification preoperatively. The purpose of this study was to investigate the impact of rTKA indications on readmission, reoperation, length of stay (LOS), and cost. METHODS: We reviewed all 962 patients who underwent aseptic rTKA at an academic orthopedic specialty hospital between June 2011-April 2020 with at least 90 days of follow-up. Patients were categorized based on their indication for aseptic rTKA as listed in the operative report. Demographics, surgical factors, LOS, readmission, reoperation and cost were compared between cohorts. RESULTS: There were significant differences in operative time among cohorts (p < 0.001), highest among the periprosthetic fracture group (164.2 ± 59.8 min). Reoperation rate was greatest in the extensor mechanism disruption cohort (50.0 %, p = 0.009). Total cost differed significantly among groups (p < 0.001), which was highest among the implant failure cohort (134.6 % of mean) and lowest for component malpositioning cohort (90.2 % of mean). Similarly, there were significant differences in direct cost (p < 0.001) which was highest in the periprosthetic fracture cohort (138.5 % of mean), and lowest in the implant failure cohort (90.5 % of mean). There were no differences in discharge disposition, or number of re-revisions among all groups. CONCLUSIONS: Operative time, components revised, LOS, readmissions, reoperation rate, total cost and direct cost following aseptic rTKA varied significantly between different revision indications. These differences should be noted for preoperative planning, resource allocation, scheduling, and risk-stratification. LEVEL OF EVIDENCE: III, retrospective observational analysis.

Outcomes of isolated head-liner exchange versus full acetabular component revision in aseptic revision total hip arthroplasty.

INTRODUCTION: Isolated head and liner exchange in aseptic revision total hip arthroplasty (rTHA) is an appealing option rather than full acetabular component revision; however, early outcome reports suggest high rates of complications requiring re-revision. This study seeks to compare the outcomes of these procedures. METHODS: This retrospective study assessed 124 head and liner exchanges and 59 full acetabular cup revisions conducted at a single center between 2011 and 2019 with at least 2 years of follow-up. Baseline demographics did not vary by group. Mean follow-up was 3.7 (range 2.0-8.6) years. RESULTS: In the head and liner exchange group, re-revision-free survivorship at 2 years was 79% for all-causes and 84% for aseptic reasons. In the full acetabular revision group, it was 80% for all causes (p > 0.99) and 83% for aseptic reasons (p > 0.99). The 2-year survivorship of head and liner exchange was non-inferior to that of full acetabular revision, correcting for surgical indication and history of prior revision (adj-OR 0.1.39, 95% CI, 0.62-3.28, p = 0.99). A best-fit multivariable model found that revision for instability (adj-OR=3.03, 95% CI 1.40-6.66, p = 0.005), prior revision (adj-OR 2.15; 95% CI, 0.87-5.32; p = 0.10), current smoking (adj-OR 2.07; 95% CI, 0.94-4.57; p = 0.07), and obesity (adj-OR 0.58; 95% CI, 0.24-1.36; p = 0.22) were associated with failure within 2 years. CONCLUSIONS: In this analysis, 2-year outcomes for isolated head and liner exchange were non-inferior to full acetabular component revision. A future randomised prospective study should be conducted to better assess the optimal approach to revision in an aseptic failed hip arthroplasty.

The accuracy of component positioning during revision total hip arthroplasty using 3D optical computer-assisted navigation.

INTRODUCTION: Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA. METHODS: A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position. RESULTS: Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0 mm vs 9.13 ± 7.9 mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p = 0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84 mm vs 7.14 ± 4.8 mm, p = 0.68). CONCLUSION: Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4 mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

Lack of Seasonal and Temporal Variability in Total Hip Arthroplasty Surgical Site Infections.

BACKGROUND: Surgical site infections (SSIs) are a signifi- cant cause of morbidity and mortality following total joint arthroplasty (TJA). While many risk factors are known, the seasonal and temporal associations of SSI are less under- stood. Understanding the associations can help reduce SSI rates. METHODS: We tracked rates of deep surgical site infec- tions (dSSIs) following total hip arthroplasty (THA) at a single large urban academic medical center from January 2009 through August 2018. Using a Poisson regression, we determined the monthly and seasonal variability of dSSIs. We also calculated the change in dSSI rate over the entire 9.67-year study period. RESULTS: In total, 15,703 THA cases between January 2009 and August 2018 were analyzed. There was no signifi- cant difference in the dSSI rate following THA in fall, winter, or spring as compared to summer. Similarly, there was no significant difference in dSSIs in July as compared to other months of the year. The average rate of dSSIs following THA was 1.04 (SD, 0.90) per 100 patients. The dSSI rate following THA decreased over the study period (r = 0.93, 95% CI: 0.84-1.03) but did not reach statistical significance. CONCLUSION: This study demonstrated a non-significant, albeit decreasing, rate of dSSIs following THA over the study period. Contrary to previous reports, there was no difference in the dSSI rate in the summer months as compared to other seasons. The month of the year also does not appear to be a significant risk factor for SSIs, calling into question previous reports arguing for the importance of the "July effect."

Minimum 2-Year Outcomes of a Novel 3D-printed Fully Porous Titanium Acetabular Shell in Revision Total Hip Arthroplasty.

Background: Fully porous acetabular shells are an appealing choice for patients with extensive acetabular defects undergoing revision total hip arthroplasty (rTHA). This study reports on the early outcomes of a novel 3-D printed fully porous titanium acetabular shell in revision acetabular reconstruction. Methods: A multicenter retrospective study of patients who received a fully porous titanium acetabular shell for rTHA with a minimum of 2 years of follow-up was conducted. The primary outcome was rate of acetabular revision. Results: The final study cohort comprised 68 patients with a mean age of 67.6 years (standard deviation 10.4) and body mass index of 29.5 kg/m2 (standard deviation 5.9). Ninety-four percent had a preoperative Paprosky defect grade of 2A or higher. The average follow-up duration was 3.0 years (range 2.0-5.1). Revision-free survivorship at 2 years was 81% for all causes, 88% for acetabular revisions, and 90% for acetabular revision for aseptic acetabular shell failure. Eight shells were explanted within 2 years (12%): 3 for failure of osseointegration/aseptic loosening (4%) after 15, 17, and 20 months; 3 for infection (4%) after 1, 3, and 6 months; and 2 for instability (3%). At the latest postoperative follow-up, all unrevised shells showed radiographic signs of osseointegration, and none had migrated. Conclusions: This novel 3-D printed fully porous titanium shell in rTHA demonstrated good survivorship and osseointegration when used in complex acetabular reconstruction at a minimum of 2 years. Level of evidence: IV, case series.

The Temporality of Deep Surgical Site Infection Rates Following Spinal Laminectomy and Fusion.

BACKGROUND: Deep surgical site infections (dSSI) following spinal laminectomy and fusion are serious complications associated with poor patient outcomes. The objective of this study is to investigate the monthly and seasonal variability of dSSI rates following common spinal surgeries to investigate the "July effect," which refers to the alleged increase in adverse health outcomes due to new hospital trainees at the beginning of the academic year. METHODS: We performed a retrospective analysis of patients who had a dSSI following laminectomy (without fusion) or spinal fusion (with or without laminectomy) at a single large urban academic medical center between January 2009 and August 2018. The change in dSSI rate over the entire study period was calculated. The monthly and seasonal variability of dSSI were assessed using a Poisson regression model to assess for the presence of the July effect. RESULTS: A total of 7931 laminectomies and 14,637 spinal fusions were reviewed. The average dSSI rates following laminectomy and spinal fusion were 0.46 (SD, 0.47) and 1.26 (SD, 0.86) per 100 patients, respectively. The rate of dSSI following spinal fusion significantly decreased over the study period (rate ratio [RR] = 0.89, 95% CI 0.84-0.94, P < 0.01). With summer as the reference season, there were significantly lower dSSI rates following spinal fusions performed in the fall (RR = 0.62, 95% CI 0.39-0.98, P = 0.04 ). With July as the reference month, there was a significantly higher dSSI rate in April following spinal fusions. CONCLUSION: The overall decrease in dSSI rate over the study period is consistent with previous reports. The monthly analysis revealed no significant differences in either procedure, calling into question the July effect. CLINICAL RELEVANCE: This study is relevant to practicing spinal surgeons and can inform surgeons about seasonal data regarding dSSIs.

Prior Instability is Strongly Associated With Dislocation After Isolated Head and Liner Exchange.

BACKGROUND: Isolated head and liner exchange is an appealing alternative to a more extensive revision total hip arthroplasty in patients who have well-fixed components. Despite efforts to increase femoral offset and restore soft tissue tensioning, limited component revision may be associated with higher rates of postoperative instability. METHODS: This retrospective analysis assessed 209 patients who had a head and liner exchange conducted at a large academic medical center between 2011 and 2019 and had >2 years of follow-up. Functional cup positioning within the Lewinnek safe zone was assessed on postoperative weight-bearing radiographs. Included patients were 56% women, had a mean age of 64 years (range, 24-89) and a mean body mass index of 28.8 kg/m2 (range, 18.2-46.7). The most common indications for surgery included acetabular liner wear in 86 hips (41%), instability in 40 hips (19%), and infection in 36 hips (17%). RESULTS: Twenty-eight hips (13%) had a dislocation within 2 years after surgery. The best-fit model predicting postoperative dislocation included a history of dislocation (adjusted-odds ratio [adj-OR] 5.67, 95% CI 2.39-14.09, P < .001), age (adj-OR 1.04 per 1-year increase, 95% CI 0.99-1.08, P = .10), and body mass index (adj-OR 0.90 per 1-kg/m2 increase, 95% CI 0.80-0.99, P = .046). CONCLUSION: In a large cohort of patients who had isolated head and liner exchange, patients who had prior instability had 7-fold elevated odds of postoperative dislocation. This risk remains significant after controlling for cup positioning outside the Lewinnek safe zone, liner type, head size, neck length, soft tissue compromise, neuromuscular disease, and dual mobility constructs. LEVEL OF EVIDENCE: III, retrospective cohort study.

Are there avoidable causes of early revision total knee arthroplasty?

INTRODUCTION: Surgeons can improve their practice by understanding potentially avoidable reasons for early revision total knee arthroplasty (rTKA). The purpose of this study is to describe potentially avoidable indications for rTKA within 5 years of the index procedure. METHODS: This retrospective observational analysis utilized the rTKA database at a large, academic orthopedic specialty hospital to identify 167 consecutive rTKA from 2014 to 2019 performed within 5 years after primary TKA (pTKA). Two fellowship-trained arthroplasty surgeons reviewed the cases to classify them as potentially avoidable or unavoidable. Unavoidable indications for rTKA included infection/wound complication, arthrofibrosis, instability due to underlying collagen disease or significant weight loss, and any traumatic event leading to pTKA failure. Potentially avoidable indications included atraumatic instability, intraoperative fracture, metal allergy, and atraumatic patellar instability or maltracking. Aseptic loosening was considered avoidable if it occurred in the presence of component malpositioning or poor cementation technique. RESULTS: There were 112 (67.1%) unavoidable cases and 55 avoidable cases (32.9%). Of the unavoidable cases, there were 68 rTKA for infection or wound complications (60.7%), 23 for arthrofibrosis (20.5%), 6 for instability (5.4%), 6 for postoperative fracture (5.4%), 6 for aseptic loosening (5.4%), and 3 for extensor mechanism pathology following trauma (2.6%). Of the potentially avoidable rTKA, 24 were for aseptic loosening (43.7%), 23 for atraumatic instability (41.8%), 6 for atraumatic extensor mechanism pathology (10.9%), 1 for nickel allergy (1.8%), and 1 for intraoperative fracture (1.8%). CONCLUSION: These findings indicate that over 30% of early rTKA are potentially avoidable. Interventions should focus on addressing potentially avoidable causes such as short-term aseptic loosening and instability to reduce the need for costly and resource-intensive rTKA. Level of evidence III, retrospective observational analysis.

How Accurate Is ICD-10 Coding for Revision Total Knee Arthroplasty?

BACKGROUND: The International Classification of Diseases-10 (ICD-10) came into effect in October 2015. The new procedural codes (ICD-10-PCS) were designed to specify granular aspects of the procedure, including laterality and revised components. This specificity could improve data collection in institutional databases, large registries, and administrative claims data. Given these possible applications, this study's purpose was to assess the accuracy of ICD-10-PCS coding for revision total knee arthroplasty (rTKA). METHODS: This multicenter retrospective analysis utilized the rTKA databases at four academic medical centers for all aseptic rTKAs between October 1, 2015 and July 3, 2019. Operative reports were reviewed to determine laterality and revised components (tibial, femoral, liner, and patellar component), which were then compared with the ICD-10-PCS codes associated with the billing records. Proper coding required both component removal and replacement codes. The correct series of removal and replacement codes was determined using the American Joint Replacement Registry's guidelines. RESULTS: In total, 1906 rTKAs were examined, and 98.0% had at least one proper ICD-10-PCS code, indicating an rTKA had occurred. Coding for components replaced was correct in 76.3% of cases. When examining both removal and replacement codes, accuracy dropped to 57.0%. CONCLUSION: Nearly 25% of rTKA procedures were incorrectly coded for replaced components, and over 40% were incorrectly coded for removed and replaced components. ICD-10-PCS codes can accurately identify that an rTKA has occurred; however, the inaccuracy in identifying which specific components were revised should prompt further evaluation of the coding process before utilizing ICD-10-PCS codes to report granular rTKA data. LEVEL OF EVIDENCE: III, retrospective observational analysis.

What Are the Rate and Risk Factors for Developing a Complication With the Pavlik Method for the Treatment of Hip Dysplasia?

BACKGROUND: The Pavlik method for the treatment of developmental dysplasia of the hip (DDH) has been proven successful for over 85 years. The high success rate and reproducibility have made it the mainstay of treatment. METHODS: We performed a retrospective cohort study of patients with DDH treated with the Pavlik method between September 2016 and August 2018 with at least 24 months of follow up in a single academic center. We excluded patients with neuromuscular conditions, teratologic dislocations, and arthrogryposis. We identified and included a total of 307 patients in the analysis. There were 66 patients with dysplasia, 97 with instability, and 144 with a dislocation. Data collected included age at initiation of the Pavlik method, diagnosis (isolated dysplasia, subluxation, or dislocation), duration of treatment, follow up duration and any complication. At final follow up, anteroposterior radiographs of the pelvis were used to determine the Severin classification. RESULTS: Major complications were proximal femoral growth disturbance (5.8%) and femoral nerve palsy (0.98%). Multivariate analysis showed that an initial diagnosis of a dislocated hip (odds ratio, 2.20; P<0.01), was significantly associated with developing a complication. At final follow up, we found Severin type I or II radiographic findings in 100% of patients with dysplasia, 95% of patients with instability and 54% of patients with dislocation (P=0.001). CONCLUSIONS: Complications are not entirely uncommon when the Pavlik method is used for the treatment of DDH. The overall rate of major complications was 7%. The Pavlik method is safe, and independent risk factors for complications were being over 5 months of age and having a dislocated hip at initial presentation. LEVEL OF EVIDENCE: Level IV-cohort study.

ICD-10 Coding Mismatch in Computer and Robotic Assisted Primary Total Hip Arthroplasty.

BACKGROUND: The International Statistical Classification of Disease, 10th Revision Procedural Coding System (ICD-10-PCS) is a granular procedural classification system with the ability to precisely classify types of technology utilized in total hip arthroplasty (THA). However, coding nuances and the rapidly evolving nature of technology may lead to coding inaccuracies. The purpose of this study is to determine the accuracy of ICD-10-PCS coding in computer-navigated and robotic THA and discuss its implications on clinical data. METHODS: The arthroplasty database at a single institution was retrospectively reviewed for all primary computer and robotic assisted THAs performed between October 2015 to November 2020. The type of technology utilized was determined from the surgical record and compared with the ICD-10-PCS codes applied to each procedure. RESULTS: A total of 3721 technology-assisted THAs were identified and reviewed. 87.5% of technology-assisted THAs were coded with the correct type of technology. The most common error in computer navigated THA was the omission of the technology code, while the most common error in robotic assisted THA was the designation of codes for both computer navigation and robotic assistance. CONCLUSION: The granular nature of ICD-10-PCS allows for precise distinction between types of technology-assisted THA. However, rates of coding inaccuracy bring concern for the integrity of this data. The inaccuracy of ICD-10-PCS data is not insignificant and should bring concern for the validity of collective data sets that use it exclusively for its procedural granularity.

Has There Been a Change in the Age of Presentation of Patients With DDH After the Implementation of a Dedicated Ultrasound-screening Program?

BACKGROUND: We sought to determine if the age of patients presenting to a tertiary subspecialty hospital dedicated to pediatric orthopaedics has changed over the last 21 years and determine if a dedicated ultrasound-screening program implemented in 2006 made any difference. METHODS: We reviewed the hospital charts for 9299 patients diagnosed with developmental dysplasia of the hip (DDH) and determined the age at the time of presentation; this was a consecutive series of all patients presenting between 1998 and 2019. We determined the diagnosis and age from the chart, 8011 were female (86.15%), and 1288 were male (13.85%). The left hip was affected in 4588 cases (49.34%), the right hip in 1824 cases (19.62%), and there were 2887 bilateral cases (31.05%). RESULTS: Over the 21 years, the mean age of presentation was 2.36 years (range, 0.1 to 17 y). In 1998, the mean age was 2.49 years (range, 0.1 to 16 y). In 2006, a dedicated ultrasound-screening clinic was instituted. The mean age decreased to 1.70 years in 2019 (range, 0.1 to 14 y). The mean age at presentation decreased significantly from 2.65 years, between 1998 and 2005, to 2.19 between 2006 and 2019 (P=0.0067). CONCLUSIONS: The implementation of a dedicated ultrasound-screening protocol was significantly correlated with a decrease in the mean age of diagnosis of DDH. The results of treatment of DDH are known to be better the sooner the diagnosis is made. Given that the age of presentation remains a challenge, especially in developing countries, a dedicated ultrasound-screening program is one step to improve our ability to detect DDH in patients at a younger age. LEVEL OF EVIDENCE: Level IV-diagnostic.