Is a Failed Spinal Attempt Associated with a Worse Clinical Course Following Primary Total Hip and Knee Arthroplasty?

INTRODUCTION: Spinal anesthesia (SA) is the preferred anesthesia modality for total joint arthroplasty (TJA). However, studies establishing SA as preferential may be subject to selection bias given that general anesthesia (GA) is often selectively utilized on more difficult, higher-risk operations. The optimal comparison group, therefore, is the patient converted to GA due to a failed attempt at SA. The purpose of this study was to determine risk factors and outcomes following failed SA with conversion to GA during primary total hip (THA) or knee arthroplasty (TKA). METHODS: A consecutive cohort of 4,483 patients who underwent primary TJA at our institution was identified (2,004 THA and 2,479 TKA). Of these patients, 3,307 underwent GA (73.8%), 1,056 underwent SA (23.3%), and 130 patients failed SA with conversion to GA (2.90%). Primary outcomes included rescue analgesia requirement in the post-anesthesia care unit (PACU), time to ambulation, pain scores in the PACU, estimated blood loss (EBL), and 90-day complications. RESULTS: Risk factors for SA failure included older age and a higher comorbidity burden. Failure of SA was associated with increased EBL, rescue intravenous (IV) opioid use, and time to ambulation when compared to the successful SA group in both THA and TKA patients (P < 0.001). The anesthesia modality was not associated with significant differences in PACU pain scores. The 90-day complication rate was similar between the failed SA and GA groups. There was a higher incidence of post-operative pain prompting unplanned visits and thromboembolism when comparing failed SA to successful SA in both THA and TKA patients (P < 0.05). CONCLUSION: In our series, patients who had failed SA demonstrated inferior outcomes to patients receiving successful SA and similar outcomes to patients receiving GA who did not have an SA attempt. This emphasizes the importance of success in the initial attempt at SA for optimizing outcomes following TJA.

Can ChatGPT Answer Patient Questions Regarding Total Knee Arthroplasty?

The internet has introduced many resources frequently accessed by patients prior to orthopaedic visits. Recently, Chat Generative Pre-Trained Transformer, an artificial intelligence-based chat application, has become publicly and freely available. The interface uses deep learning technology to mimic human interaction and provide convincing answers to questions posed by users. With its rapidly expanding usership, it is reasonable to assume that patients will soon use this technology for preoperative education. Therefore, we sought to determine the accuracy of answers to frequently asked questions (FAQs) pertaining to total knee arthroplasty (TKA).Ten FAQs were posed to the chatbot during a single online interaction with no follow-up questions or repetition. All 10 FAQs were analyzed for accuracy using an evidence-based approach. Answers were then rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification."Of the 10 answers given by the chatbot, none received an "unsatisfactory" rating with the majority either requiring minimal (5) or moderate (4) clarification. While many answers required nuanced clarification, overall, answers tended to be unbiased and evidence-based, even when presented with controversial subjects.The chatbot does an excellent job of providing basic, evidence-based answers to patient FAQs prior to TKA. These data were presented in a manner that will be easily comprehendible by most patients and may serve as a useful clinical adjunct in the future.

Central Sensitization: The Missing Link Between Psychological Distress and Poor Outcome Following Primary Total Knee Arthroplasty.

BACKGROUND: While preoperative psychological distress is known to predict risk for worse total knee arthroplasty (TKA) outcomes, distress may be too broad and nonspecific a predictor in isolation. We tested whether there are distinct preoperative TKA patient types based jointly on psychological status and measures of altered pain processing that predict adverse clinical outcomes. METHODS: In 112 TKA patients, we preoperatively assessed psychological status (depression, anxiety, and catastrophizing) and altered pain processing via a simple quantitative sensory testing protocol capturing peripheral and central pain sensitization. Outcomes (pain, function, opioid use) were prospectively evaluated at 6 weeks and 6 months after TKA. Cluster analyses were used to empirically identify TKA patient subgroups. RESULTS: There were 3 distinct preoperative TKA patient subgroups identified from the cluster analysis. A low-risk (LR) group was characterized by low psychological distress and low peripheral and central sensitization. In addition, 2 subgroups with similarly elevated preoperative psychological distress were identified, differing by pain processing alterations observed: high-risk centralized pain and high-risk peripheral pain. Relative to LR patients, high-risk centralized pain patients displayed significantly worse function and greater opioid use at 6 months after TKA (P values <.05). The LR and high-risk peripheral pain patient subgroups had similar 6-month outcomes (P values >.05). CONCLUSIONS: Among patients who have psychological comorbidity, only patients who have central sensitization were at elevated risk for poor functional outcomes and increased opioid use. Central sensitization may be the missing link between psychological comorbidity and poor TKA clinical outcomes. Preoperative testing for central sensitization may have clinical utility for improving risk stratification in TKA patients who have psychosocial risk factors.

Preoperative Predictors of Prolonged Opioid Use in the 6 Months After Total Knee Arthroplasty.

OBJECTIVES: Prolonged postoperative opioid use increases the risk for new postsurgical opioid use disorder. We evaluated preoperative phenotypic factors predicting prolonged postoperative opioid use. METHODS: We performed a secondary analysis of a prospective observational cohort (n=108) undergoing total knee arthroplasty (TKA) for osteoarthritis with 6-week and 6-month follow-up. Current opioid use and psychosocial, pain, and opioid-related characteristics were assessed at preoperative baseline. Primary outcomes were days/week of opioid use at follow-up. RESULTS: At 6 weeks, preoperative opioid use and greater cumulative opioid exposure, depression, catastrophizing, anxiety, pain interference, sleep disturbance, and central sensitization were significantly associated with more days/week of opioid use after controlling for contemporaneous pain intensity. Prior euphoric response to opioids were also significant predictors at 6 months. All 6-week predictors except anxiety remained significant after controlling for preoperative opioid use; at 6 months, cumulative opioid exposure, catastrophizing, pain interference, and sleep disturbance remained significant after this adjustment ( P <0.05). In multivariable models, a psychosocial factor reflecting negative affect, sleep, and pain accurately predicted 6-week opioid use (area under the curve=0.84). A combined model incorporating psychosocial factor scores, opioid-related factor scores, and preoperative opioid use showed near-perfect predictive accuracy at 6 months (area under the curve=0.97). DISCUSSION: Overall, preoperative psychosocial, pain-related, and opioid-related phenotypic characteristics predicted prolonged opioid use after total knee arthroplasty.

Assessing ChatGPT Responses to Common Patient Questions Regarding Total Hip Arthroplasty.

BACKGROUND: The contemporary patient has access to numerous resources on common orthopaedic procedures before ever presenting for a clinical evaluation. Recently, artificial intelligence (AI)-driven chatbots have become mainstream, allowing patients to engage with interfaces that supply convincing, human-like responses to prompts. ChatGPT (OpenAI), a recently developed AI-based chat technology, is one such application that has garnered rapid growth in popularity. Given the likelihood that patients may soon call on this technology for preoperative education, we sought to determine whether ChatGPT could appropriately answer frequently asked questions regarding total hip arthroplasty (THA). METHODS: Ten frequently asked questions regarding total hip arthroplasty were posed to the chatbot during a conversation thread, with no follow-up questions or repetition. Each response was analyzed for accuracy with use of an evidence-based approach. Responses were rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," "satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification." RESULTS: Of the responses given by the chatbot, only 1 received an "unsatisfactory" rating; 2 did not require any correction, and the majority required either minimal (4 of 10) or moderate (3 of 10) clarification. Although several responses required nuanced clarification, the chatbot's responses were generally unbiased and evidence-based, even for controversial topics. CONCLUSIONS: The chatbot effectively provided evidence-based responses to questions commonly asked by patients prior to THA. The chatbot presented information in a way that most patients would be able to understand. This resource may serve as a valuable clinical tool for patient education and understanding prior to orthopaedic consultation in the future.

2022 American Association of Hip and Knee Surgeons Symposium: Periprosthetic Joint Infection.

Periprosthetic joint infection (PJI) is the leading cause of failure in patients undergoing total joint arthroplasty. This article is a brief summary of a symposium on PJI that was presented at the annual AAHKS meeting. It will provide an overview of current technqiues in the prevention, diagnosis, and management of PJI. It will also highlight emerging technologies in this setting.

Dexamethasone Is Associated With a Statistically Significant Increase in Postoperative Blood Glucose Levels Following Primary Total Knee Arthroplasty.

Background: Dexamethasone has the potential to cause a transient increase in blood glucose levels. Recent evidence has suggested the potential for a linearly increased risk of periprosthetic joint infection beginning at blood glucose levels of ≥115 mg/dL and an optimal cutoff of 137 mg/dL. We designed the following study to determine (1) what percentage of our patients had postoperative day 1 (POD1) glucose levels above 137 mg/dL and (2) if the administration of dexamethasone further increased this risk. Methods: All primary total knee arthroplasties performed from 1998 to 2021 at our institution were identified and retrospectively reviewed. Patient demographics, dexamethasone administration, and perioperative glucose levels were recorded. Outcomes included POD1 glucose levels, infection rate, and all-cause reoperations and revisions. Results: The average POD1 glucose level for the entire cohort (n = 5353) was 138.7 mg/dL. The percentage of patients with a glucose level of 137 mg/dL or higher was significantly greater in patients that received dexamethasone (55.2% vs 37.7%; P < .0001). Significantly higher glucose levels were seen with dexamethasone administration in both diabetic (187.7 vs 173.4 mg/dL; P < .0001) and nondiabetic patients (137.7 vs 128.0 mg/dL; P < .0001). Dexamethasone use was associated with a nonstatistically significant increase in infection rates (1.7% vs 1.0%; P = .177). Conclusions: Administration of dexamethasone is associated with a statistically significant increase in POD1 glucose levels, regardless of diabetic status. Dexamethasone use should continue to be closely monitored given the potential risks of elevated postoperative glucose levels and the potential for periprosthetic infection.

Is cement mantle thickness a primary cause of aseptic tibial loosening following primary total knee arthroplasty?

BACKGROUND: Aseptic tibial loosening following primary total knee replacement is one of the leading causes of long-term failure. Cement mantle thickness has been implicated as a source of aseptic tibial loosening. Therefore, the following study was designed to determine (1) what is the cement mantle thickness in patients that develop aseptic tibial loosening, and (2) is there a difference in cement mantle thickness based on the interface of failure? METHOD: This retrospective cohort included 216 patients revised for aseptic tibial loosening. Patient demographics, operative data, and clinical outcomes were recorded. A preoperative radiographic assessment was performed to determine the interface of failure and the thickness of the cement mantle using the Knee Society Radiographic Evaluation System zones. RESULTS: The average patient age was 65 years and body mass index was 33.7 kg/m2. 203 patients demonstrated radiographic failure at the implant-cement interface and 13 patients demonstrated failure at the cement-bone interface. The average cement mantle thickness of each radiographic zone for the entire cohort on the AP and lateral views was 4.4 and 4.5 mm, respectively. The average cement mantle thickness of patients that developed failure at the implant-cement interface was significantly greater than patients that failed at the cement-bone interface in each radiographic zone (p < 0.001). CONCLUSIONS: Patients that develop implant loosening at the cement-bone interface were noted to have a significantly decreased cement mantle compared to patients that failed at the implant-cement interface. Methods for decreasing tibial implant loosening should likely focus on improving the fixation at the implant-cement interface.

Trends in Total Knee Arthroplasty Cementing Technique Among Arthroplasty Surgeons-A Survey of the American Association of Hip and Knee Surgeons Members.

BACKGROUND: Aseptic loosening persists as one of the leading causes of failure following cemented primary total knee arthroplasty (TKA). Cement technique may impact implant fixation. We hypothesized that there is variability in TKA cement technique among arthroplasty surgeons. METHODS: A 28-question survey regarding variables in surgeons' preferred TKA cementation technique was distributed to 2,791 current American Association of Hip and Knee Surgeons (AAHKS) members with a response rate of 30.8% (903 respondents). Patterns of responses were analyzed by grouping respondents by their answers to certain questions including cementing technique, tibial cement location, and femoral cement location. RESULTS: A total of 73.5% reported performing at least 7 of 8 of the highest consensus techniques, including vacuum mixing (79.9%), using two bags (76.1%), tibial implant first (95.2%), single-stage cementing (96.9%), compression of the implants in extension (91.7%), and use of a tourniquet (84.3%). Medium and high viscosity cement was most commonly used (37.9 and 37.8%, respectively). Finger pressurization was most common (76.1%) compared to a gun (29.8%). There were 26.5% of respondents performing 6 or fewer of the most common majority techniques and seemed to perform other less common techniques (eg, use of a single bag of cement, trialing or closure prior to cement curing, and heating to accelerate cement curing). Cement was most commonly applied to the entire bone and implant surface on both the tibia (46.4%) and femur (47.7%), leaving much variation in the remaining cement application location responses. DISCUSSION: There appears to be variability in cemented TKA technique among arthroplasty surgeons. There were 26.5% of respondents performing less of the majority techniques and also performed other additional low-response rate techniques. Further studies that look at the impacts of variation in techniques on outcomes may be warranted. Our study demonstrates the need for defining best practices for cement technique given the substantial variability identified.

Location of Initial Closed Reduction Attempt Significantly Increases Cost and Length of Stay in Total Hip Arthroplasty.

Background: Prosthetic hip dislocation remains one of the most frequent complications following total hip replacement. Dislocations are predominantly managed by a closed reduction in the emergency department (ED) or the operating room (OR). This study aimed to evaluate how the location of an initial closed reduction attempt impacts a patient's course of care including length of stay (LOS) and cost of care. Material and methods: A retrospective chart review was performed on all patients presenting to a single ED with a unilateral prosthetic hip dislocation from 2009 to 2019. A total of 108 patients were identified. Data collected included patient demographics, ED/hospital course, and hospital charges. Results: Seventy-four patients (69%) had initial reduction attempted in the ED (65/74, 88% were successful), while 34 patients (31%) went directly to OR (100% successful with closed reduction). Failed closed reduction in ED or direct to OR resulted in a greater LOS and rate of placement to a skilled nursing facility following discharge. Median hospital charges for successful ED reduction were $6,837, while failed ED closed reduction or direct to OR resulted in median charges of $27,317 and $20,481, respectively. Conclusion: Many patients successfully underwent closed reduction in the ED, and there was no difference in complications, independent of where the reduction was first performed. Patients undergoing reduction in the OR had greater LOS and cost of care, independent of whether a reduction attempt was performed and failed in the ED, than those successfully reduced in the ED.

Cruciate Substituting Implants in Primary Total Knee Arthroplasty.

The use of cruciate substituting (CS) total knee replacement has been increasing in popularity. There are numerous factors that have likely contributed to this expansion. The CS philosophy incorporates the ease of use commonly cited by advocates of the posterior stabilized (PS) total knee design with the bone preservation associated with a cruciate retaining (CR) design. The ultra-congruent highly cross-linked polyethylene liner increases stability without an appreciable change in wear. Furthermore, balancing the flexion and extension gaps does not require "titrating" the posterior cruciate ligament, improving the user-friendliness. This paper reviews the nuances of this implant design compared to PS and CR designs as well as provides surgical technique recommendations/considerations.

Total Joint Arthroplasty in Patients With Achondroplasia: Comparison of 90-Day Adverse Events and 5-Year Implant Survival.

BACKGROUND: Achondroplasia is the most common skeletal dysplasia, and total joint arthroplasty of the hip and/or knee in this patient population may present unique challenges. METHODS: All patients undergoing primary total hip or total knee arthroplasty (THA or TKA) for osteoarthritis in the 2010-2019 PearlDiver Mariner administrative database with least 90 days of postoperative follow-up were identified. Those with achondroplasia were matched 1:10 to patients without achondroplasia based on age, sex, and medical comorbidities. Ninety-day adverse events were assessed and compared using multivariate logistic regression. Five-year implant survival was determined and compared with Kaplan-Meier implant survival curves. Significance was set at P < .05. RESULTS: For THA, 150 patients with achondroplasia were matched to 1484 patients without and had significantly higher 90 days odds of surgical site infection (odds ratio [OR] = 3.49, P = .005) and readmission (OR = 2.35, P = .016). For TKA, 285 patients with achondroplasia were matched to 2828 without and had higher odds of aggregated any adverse event (OR = 1.52, P = .006) and transfusion (OR = 2.31, P < .001). Rates of the other studied adverse events were not significant for either set of the analyses. At 5 years, implant survival for those with and without achondroplasia was not different for those undergoing THA (P = .321) or TKA (P = .910). CONCLUSIONS: The present study represents the largest cohort of patients with achondroplasia undergoing total joint arthroplasty to date. Although several short-term adverse events had greater odds for those with achondroplasia, 5-year survival was not different for those with or without achondroplasia after THA or TKA, supporting confidence in longer term implant success.

Albumin and the fibrinogen-to-albumin ratio: Biomarkers for the acute phase response following total knee arthroplasty.

PURPOSE: Complications following total knee arthroplasty (TKA) lead to patient morbidity and cost. While acute phase reactants, such as c-reactive protein (CRP) and fibrinogen, have been used to predict complications following TKA, the extent and duration of changes in albumin levels following TKA are unknown. It is hypothesized that like CRP and fibrinogen, albumin, and the fibrinogen/albumin ratio (FAR) represent useful measures of the acute phase response (APR) following TKA. The purpose of this study was to describe the longitudinal course of albumin and FAR in healthy patients following TKA, relative to established biomarkers, and examine if the variance in albumin or FAR correlates with patient comorbidities. METHODS: This retrospective cohort study of patients undergoing TKA at a tertiary medical center. CRP, fibrinogen, and albumin values were collected pre- and post-operatively. An age-adjusted Charlson comorbidity index (CCI) was utilized as a measure of patient comorbidity status. RESULTS: The median preoperative albumin value was 4.3 g/dL, which dropped to 3.6 g/dL on postoperative day 1 following TKA. The albumin value returned to 93% of the baseline by postoperative week 2. The course of albumin inversely mirrored the course of CRP (r = -0.41). Median preoperative FAR was 0.087 g/L, which rose to 0.130 g/L by postoperative week 2 and returned to baseline by postoperative week 6. While preoperative FAR strongly correlated with postoperative week 2 values (r = 0.74), there was a weak positive correlation between age-adjusted CCI and pre-operative FAR (r = 0.24) in patients undergoing primary TKA. CONCLUSION: Albumin levels follow a predictable postoperative decline that inversely correlates with CRP in healthy patients following TKA. Given the low cost and abundance of laboratories offering albumin levels, direct albumin levels and/or albumin ratios such as FAR may be underutilized biomarkers for monitoring the APR following TKA.

Spinal Anesthetic Type and Independent Risk Factors for Postoperative Urinary Retention Following Total Joint Arthroplasty.

While risk factors for postoperative urinary retention (POUR) after total joint arthroplasty (TJA) have been identified, its association with type of spinal anesthetic has not yet been thoroughly investigated. Patients undergoing primary TJA between 2013-2018 were reviewed. From August 2013 to March 2016 bupivacaine was primarily given and from March 2016 through August 2018, most, although not all, received mepivacaine. Patient demographics as well as intraoperative data were recorded. One-thousand and fifty-four patients were included. POUR rates were not significantly different between groups (5.5% vs 6.1%, p = 0.675). Those who received mepivacaine had a significantly shorter length of stay (LOS) (1 vs. 2 days, p < 0.001). However, spinal anesthetic type was not significantly associated with either POUR or LOS after controlling for between-group differences. Older age (odds ratio [OR] 1.024 [95% confidence interval {CI}:1.000-1.049]; p = 0.049) and a history of benign prostatic hyperplasia or urinary incontinence/retention (OR 2.155 [95% CI:1.114-4.168]; p = 0.023) were confirmed as independent risk factors for POUR. (Journal of Surgical Orthopaedic Advances 29(4):225-229, 2020).

Do Corticosteroids Attenuate the Peri-Operative Acute Phase Response After Total Knee Arthroplasty?

BACKGROUND: Following tissue injury, the acute phase response (APR) functions to survive and then repair injured tissue. An exuberant APR, which can be evoked by total knee arthroplasty (TKA), results in a hyper-inflammatory state, leading to pain, nausea, venous thromboembolism, or potentially life-threatening complications. Here, we observed the effects of peri-operative dexamethasone on the APR following TKA by trending C-reactive protein (CRP, mg/L) and fibrinogen (mg/dL). We hypothesize that the anti-inflammatory effects of dexamethasone can attenuate the APR after TKA and will be associated with decreased post-operative pain and nausea. METHODS: A retrospective case-control study was performed on 188 unilateral TKA procedures. The patients were divided into a group receiving dexamethasone (10 mg intra-operatively and on post-operative day [POD] 1) and a group receiving no corticosteroids. Post-operative CRP, fibrinogen, morphine equivalents, and anti-emetic doses were recorded. RESULTS: Compared to the non-steroid group, patients receiving dexamethasone yielded a significantly decreased CRP on POD0 (5.5 vs 8.3), POD1 (11.8 vs 22.0), and POD2 (85.5 vs 148.9). A significant decrease in fibrinogen in patients receiving dexamethasone was seen on POD2 (460.0 vs 530.2). There was an increase in fibrinogen within the dexamethasone cohort at the 2-week visit (535.4 vs 488.9). Post-operative morphine equivalents administered were significantly decreased in patients receiving dexamethasone, but no difference in anti-emetic use was appreciated. CONCLUSION: These data support the hypothesis that the APR following TKA can be attenuated pharmacologically by corticosteroids. Further studies are needed to determine whether the attenuation of the APR with the use of corticosteroids prevents complications following TKA.

Characterizing the Acute Phase Response in Healthy Patients Following Total Joint Arthroplasty: Predictable and Consistent.

BACKGROUND: During surgery, trauma to musculoskeletal tissue induces a systemic reaction known as the acute phase response (APR). When excessive or prolonged, the APR has been implicated as an underlying cause of surgical complications. The purpose of this study was to determine the typical APR following total joint arthroplasty in a healthy population defined by the Charlson Comorbidity Index (CCI). METHODS: This retrospective study identified 180 healthy patients (CCI < 2) who underwent total joint arthroplasty by a single surgeon for primary osteoarthritis from 2013 to 2015. Serial measurements of C-reactive protein (CRP) and fibrinogen were obtained preoperative, perioperative, and at 2 and 6 weeks postoperative. RESULTS: Postoperative CRP peaked during the inpatient period and returned to baseline by 2 weeks. Fibrinogen peaked after CRP and returned to baseline by 6 weeks. Elevated preoperative CRP correlated with a more robust postoperative APR for both total hip arthroplasty and total knee arthroplasty, suggesting that a patient's preoperative inflammatory state correlates with the magnitude of the postoperative APR. CONCLUSION: Measurement of preoperative acute phase reactants may provide an objective means to predict a patient's risk of postoperative dysregulation of the APR and complications.

Practice Management Strategies Among Current Members of the American Association of Hip and Knee Surgeons.

BACKGROUND: A survey was conducted at the 2015 annual meeting of the American Association of Hip and Knee Surgeons (AAHKS) to determine current practice management patterns among AAHKS members. METHODS: A survey was conducted by the session moderator during the annual AAHKS meeting using an audience response system. A series of practice management issues were reviewed with AAHKS members. The survey contained multiple choice and yes and no questions. The audience responses were collected in a central database and then immediately displayed for the audience to review. RESULTS: The survey responses provided interesting data on a variety of topics including: surgeon demographics, surgical activity, practice status, use of physician extenders, sources of ancillary income, the use of electronic medical records and surgeon satisfaction. Interestingly, 51% of AAHKS members remain in private practice and fee for service remains the most common form of compensation (48%). The vast majority of AAHKS members do not perform hip arthroscopy (86%) or hip preservation procedures (87%). CONCLUSION: Valuable information regarding practice patterns of AAHKS members was obtained from this survey. Future surveys will need to focus on 3 areas of activity: surgeon involvement in bundled payment programs frequency of submission of patient data to a joint registry and the frequency of outpatient total joint arthroplasty.

Elevated d-Dimer Is Not Predictive of Symptomatic Deep Venous Thrombosis After Total Joint Arthroplasty.

BACKGROUND: Serum d-dimer is a common screening test for symptomatic deep venous thrombosis (DVT) after total joint arthroplasty. This study characterized the longitudinal resolution of d-dimer measurements after total hip and knee arthroplasty (THA/TKA) over a 6-week period. The authors hypothesized that serum d-dimer would not return to baseline or be below the institutional threshold for a positive test at 6 weeks after uncomplicated total joint arthroplasty, suggesting that quantitative d-dimer has limited clinical utility for postoperative DVT screening. METHODS: An institutional review board-approved retrospective cohort study was conducted with consecutive patients between January 2013 and June 2015. A total of 177 adult patients aged 40-88 years who underwent a primary hip or knee arthroplasty with a Charlson Comorbidity Index <3 were included in the study. Serum d-dimer was measured at preoperative, perioperative, and postoperative 2- and 6-week time points. RESULTS: d-dimer measurements peaked 2 weeks postoperatively for both TKA and THA. At the 6-week time point, the peak serum d-dimer measurement resolved by 54.3% and 76.6% for TKA and THA, respectively. At 6 weeks after operation, 92% of THA patient and 100% of TKA patients had serum d-dimer measurements higher than the institutional threshold (0.40 µg/mL) for a "positive" quantitative test. No symptomatic DVTs were reported for the THA and TKA cohorts during the study period. CONCLUSION: The results suggest that serum d-dimer is an ineffective screening test for the diagnosis of symptomatic DVT in the acute postoperative period. The authors propose that extravascular fibrinolysis, a process essential for wound healing, has a crucial role in the prolonged elevation of serum d-dimer in the postoperative period.

Screening for deep vein thrombosis after periacetabular osteotomy in adult patients: is it necessary?

BACKGROUND: The periacetabular osteotomy has become a common procedure for treating symptomatic acetabular dysplasia. Like other major hip procedures, there is concern regarding the risk of associated venous thromboembolic disease. Nevertheless, there is limited information regarding the need for screening, and optimal prophylactic measures have not been established. QUESTIONS/PURPOSES: We sought to determine the frequency of thromboembolic events (deep vein thrombosis [DVT] and symptomatic pulmonary embolism [PE]) associated with the periacetabular osteotomy in in patients receiving aspirin and mechanical compression prophylaxis. METHODS: We performed a retrospective review of 134 adult patients (149 hips) treated with the periacetabular osteotomy during an 8-year period. During this period, 136 (91%) of the hips treated with a periacetabular osteotomy were screened within 1 week for DVT, whereas 13 (9%) could not be evaluated for various reasons. The mean age of the patients at the time of surgery was 30 years (range, 18-60 years), and no patients were lost to followup during the 4 to 6 months after surgery. The same thromboembolic prophylactic regimen was used for all patients. This consisted of 325 mg aspirin twice a day and compression stockings for 6 weeks and lower extremity pneumatic compression devices while hospitalized. Screening bilateral lower extremity ultrasonography was performed within 1 week (mean, 4 days) of the procedure to detect asymptomatic DVTs. RESULTS: Of the 134 patients, two patients (two hips) with negative postoperative screening ultrasounds presented at 14 and 38 days postoperatively with clinical symptoms of DVT. Repeat ultrasound confirmed this diagnosis in both cases. There were no symptoms of PE. Screening venous ultrasonography did not identify any DVTs during the early postoperative period before discharge. These two patients were treated with 3 to 6 months of warfarin anticoagulation. Neither patient had persistent symptoms related to the DVT. CONCLUSIONS: These data indicate that the risk of symptomatic DVT associated with periacetabular osteotomy is low (1%) with use of aspirin and mechanical compression prophylaxis. Furthermore, routine postoperative screening did not detect any patients with an asymptomatic DVT. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.