Variability in Acetabular Component Position in Patients Undergoing Direct Anterior Approach Total Hip Arthroplasty Who Have Concomitant Spine Pathology.

BACKGROUND: Hip instability following total hip arthroplasty (THA) can be a major cause of revision surgery. Physiological patient position impacts acetabular anteversion and abduction, and influences the functional component positioning. Osteoarthritis of the spine leads to abnormal spinopelvic biomechanics and motion, but there is no consensus on the degree of component variability for THAs performed by anterior approach. Therefore, we sought to present guidelines for changes in acetabular component positioning between supine and standing positions for patients undergoing primary THA by a uniform anterior approach. METHODS: Perioperative patient radiographs of the pelvis and lumbar spine were collected. Images were used to determine acetabular component positioning and degree of coexisting spinal pathology, categorized as a Lane Grade (LG). Final analysis of variance was performed on a sample size of 643 anterior primary THAs. RESULTS: From supine to standing position, as the severity of lumbar pathology increased the change in anteversion also increased (LG:0 = -0.11° ± 4.65°, LG:1 = 2.02° ± 4.09°, LG:2-3 = 5.78° ± 5.72°, P < .001). The mean supine anteversion in patients with absent lumbar pathology was 19.72° ± 5.05° and was lower in patients with worsening lumbar pathology (LG:1 = 18.25° ± 4.81°, LG:2-3 = 16.73° ± 5.28°, P < .001). CONCLUSION: Patients undergoing primary THA by anterior approach with worsening spinal pathology have larger increases in component anteversion when transitioning from supine to standing positions. Consideration should be given to this expected variability when placing the patient's acetabular component.

Does Intermittent Catheterization Compared to Indwelling Catheterization Decrease the Risk of Periprosthetic Joint Infection Following Total Knee Arthroplasty?

BACKGROUND: Catheterization for the prophylaxis against or treatment for urinary retention commonly occurs after total knee arthroplasty (TKA). Recent studies have questioned the use of the indwelling catheterization, especially in its potential role as a nidus for infection. We are still unsure of its downstream effects on periprosthetic joint infections (PJIs). Therefore, this study aimed to compare the risks of postoperative PJI following intermittent vs indwelling catheterization after TKA. METHODS: Between 2017 and 2019, 15 hospitals in a large health system collected data on patients undergoing TKA. Patient treatments with indwelling catheter only, intermittent straight catheter only, and both indwelling and intermittent straight catheterizations were recorded. Patient demographics, comorbidities, body mass indices, and PJIs were collected from time of surgery to time of data collection at mean 14 months of follow-up. Univariate and multivariate analyses were performed with independent t-tests and multiple linear regression models to compare catheterization treatment types. RESULTS: A total of 9123 TKAs were performed, with patients receiving indwelling catheter only (62%, n = 734), intermittent straight catheter only (25%, n = 299), or both indwelling and intermittent catheterizations (13%, n = 160). Univariate analyses showed that PJIs occurred in 1.1% of no-catheter patients and 2.3% of patients treated with bladder catheterization (P = .002). Using multivariate analyses, indwelling catheter use (odds ratio [OR] 2.647, P < .001), diabetes (OR 1.837, P = .005), and peripheral vascular disease (OR 2.372, P = .046) were found to have a statistically significant increased risk for PJIs. The use of intermittent straight catheterization (OR 1.249, P = .668) or both indwelling and intermittent (OR 1.171, P = .828) did not increase the risk for PJIs. CONCLUSION: Urinary bladder catheterization is commonly required for prophylaxis against or treatment for urinary retention following TKA. The use of a urinary catheter can provide a potential nidus for infection in these patients. This study found that indwelling catheterization, but not intermittent catheterization, was associated with an increased risk for PJI. Surgeons should therefore limit the duration of catheterization in an effort to decrease the risk for PJI.

The Effect of Bladder Catheterization Technique on Postoperative Urinary Tract Infections After Primary Total Hip Arthroplasty.

BACKGROUND: Urinary bladder catheters are potential sources of infection after total hip arthroplasty (THA). Therefore, the goal of this study was to determine if intermittent catheterization provides a decreased risk of postoperative urinary tract infections (UTIs) compared with indwelling catheterization in THA patients. METHODS: Patients undergoing THA at 15 hospitals within a large health system were prospectively collected between 2017 and 2019 and then stratified based on catheterization technique: no-catheter; indwelling catheter-only; intermittent catheter-only; and both intermittent and indwelling catheter. Patient demographics, medical comorbidities, anesthesia types, and postoperative UTIs were assessed. Independent Student t-tests were used to perform univariate analyses for the catheterization groups. Multiple linear regression models were used to compare the different groups while controlling for confounding variables. RESULTS: There were a total of 7306 THA patients recorded with 5513 (75%) no-catheter, 1181 (16%) indwelling catheter-only, 285 (3.9%) intermittent catheter-only, and 327 (4.5%) indwelling and intermittent catheterization patients. A total of 580 patients experienced postoperative UTI. Urinary bladder catheterization increased the risk of postoperative UTIs (P < .001) in univariate analyses. Multiple linear regression models showed that indwelling catheter-only (OR: 2.178, P < .001), intermittent catheterization (OR: 1.975, P = .003), and both indwelling and intermittent (OR: 2.372, P = .002) were more likely to experience UTIs compared with no catheters. CONCLUSION: This study found that patients treated with indwelling catheterization, with or without preceding intermittent catheterization, were significantly more likely to experience UTIs. Therefore, in an effort to decrease the risk of UTIs, THA patients experiencing postoperative urinary retention should be treated with intermittent catheterization.

The Cumulative Effect of Substance Abuse Disorders and Depression on Postoperative Complications After Primary Total Knee Arthroplasty.

BACKGROUND: Substance abuse disorder (SUD), alcohol abuse disorder (AUD), and depression have been identified as independent risk factors for complications after total knee arthroplasty (TKA). However, these mental health disorders are highly co-associated, and their cumulative effect on postoperative complications have not been investigated. Therefore, this study aimed to determine if patients who have more than one mental health disorder (SUD, AUD, or depression) were at an increased risk for postoperative complications following TKA. METHODS: A total of 11,403 TKA patients were identified from a prospectively collected institutional database between January 1, 2017 and April 1, 2019. Patients who had depression, SUD, and AUD were separated into 7 mental health subgroups including each of these diagnoses alone and their combined permeations. Patient demographics, body mass indices, medical comorbidities, and 15 postoperative complications were collected. Univariate analyses were performed using independent Student's t-tests. Multivariate analyses were then performed to identify odds ratios (ORs) for mental health disorders subgroups associated with complications. RESULTS: We found a total of 2073 (18%) patients diagnosed with either SUD (4%), AUD (0.6%), or depression (12%). Univariate analyses showed that depression was associated with mechanical failures (P < .001). SUD was associated with periprosthetic joint infection (PJI) (P < .001), wound complications (P = .022), and aseptic loosening (P = .007). AUD was associated with PJI (P < .001) and deep vein thromboses (P = .003). Multivariate analyses found that AUD (OR: 19.419, P < .001) and SUD (OR:3.693, P = .010) were independent risk factors for PJI. Compared with SUD alone, patients with depression plus SUD were found to have a 4-fold (OR: 13.639, P < .001) and 2-fold (OR:4.401, P = .021) increased risk for PJI and cellulitis, respectively. CONCLUSIONS: Patients who had depression, SUD, or AUD were at increased risk for postoperative complications following primary TKA. When patients have more than one mental health diagnosis, their risk for complications was amplified. The results of this study can help identify those patients who are at greater risk of postoperative complications to enable improved preoperative optimization and patient education.

The Effect of Bladder Catheterization on Ambulation and Venous Thromboembolism Following Total Knee Arthroplasty: An Institutional Analysis.

BACKGROUND: Although intermittent catheters are immediately removed, indwelling catheterization may lead to decreased ambulation and participation in physical therapy, critical components to post-total knee arthroplasty (TKA) management. Therefore, this study aimed to compare the effect of catheterization treatments on (1) postoperative ambulation distances, (2) deep vein thromboses (DVTs), and (3) pulmonary emboli (PEs) following TKA. METHODS: A total of 9123 prospectively collected primary TKA patients were assessed based on postoperative catheter status. Patient demographics, Charlson Comorbidity Indices, body mass indices, DVT prophylaxes, first ambulation distances, DVTs, and PEs were collected at approximately mean 12 months of follow-up. Univariate and multivariate analyses were performed with independent t-tests and multiple linear regression models in order to compare catheterization techniques. RESULTS: There were 1193 patients who had urinary retention and treated with either indwelling only (62%, n = 734), both indwelling and intermittent catheterizations (13%, n = 160), or intermittent only (25%, n = 299). Multivariate analyses found that indwelling catheter-only use had an 11% decrease in ambulation distance (P < .001). Additionally, the indwelling catheterization-only group was found to be at increased risk of DVTs (odds ratio 2.605, P < .001), even after controlling for DVT prophylaxes (odds ratio 2.807, P < .001). CONCLUSION: This study showed that the use of an indwelling catheter for treatment of urinary retention significantly decreased TKA patient ambulation distance and subsequently increased the risk for DVTs. This information is important as we would recommend the treatment with intermittent catheterization rather than indwelling catheters to decrease the risk of immobilization and postoperative DVTs.

Monitoring Surgical Incision Sites in Orthopedic Patients Using an Online Physician-Patient Messaging Platform.

BACKGROUND: Prompt identification and treatment of wound complications is essential after joint arthroplasty, but emergency department and office visits for urgent evaluation of normal incisions are a source of unnecessary cost. The purpose of this study is to evaluate the use of an online image messaging platform for remote monitoring of surgical incision sites. METHODS: We conducted a retrospective review of 1434 hip and knee arthroplasty patients who registered for an online platform in the perioperative period. We reviewed images sent by patients to evaluate potential wound abnormalities. Medical records were reviewed to determine whether assessments based on wound photographs corresponded with subsequent in-person findings and ultimate disposition. RESULTS: Four hundred thirty patients (42%) sent at least one text or image message to their provider. Elimination of redundant images resulted in 104 image encounters, with 76 discrete encounters in 41 patients related to the surgical wound. Most showed normal wound appearance; patients were reassured and urgent visits were avoided. At scheduled in-person follow-up, none of these patients demonstrated unrecognized wound complications. Seventeen image encounters in 7 patients showed possible wound abnormalities. These prompted in-person follow-up on average less than 1 day later for 4 issues deemed urgent (2 patients received surgical treatment) and 5 days later for issues deemed nonurgent. Photos were also used to monitor abnormal wounds over time and to send information unrelated to wounds. CONCLUSION: Utilization of an online physician-patient messaging platform can prevent unnecessary visits for normal appearing wounds, while facilitating rapid in-person treatment of wound complications.

No additional benefit with use of a fibrin sealant to decrease peri-operative blood loss during primary total knee arthroplasty.

Blood loss remains a substantial problem associated TKA. This study evaluated the efficacy of a fibrin sealant on: (1) blood loss; (2) blood transfusions; and (3) length of stay. We evaluated the records of 113 consecutive patients with sealant and 70 without sealant. There was no significant difference in the hemoglobin levels (all 9.5-10 g/dL) on each of three postoperative days. There was also no significant difference in the intraoperative blood loss, postoperative blood loss or the total perioperative blood loss in both groups. The mean requirement in each patient was 2.5 ± 2.4 units in the fibrin sealant group compared to 2.0 ± 0.8 units in the non-fibrin sealant group. We have stopped using fibrin sealant based on this study.

Reproducible fixation with a tapered, fluted, modular, titanium stem in revision hip arthroplasty at 8-15 years follow-up.

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid-term to long-term outcomes of this implant. Seventy-one hips in 70 patients with a mean age of 69 years were followed for an average of 10 years. Preoperative HHS averaged 50 and improved to 87 postoperatively. Seventy-nine percent hips had Paprosky type 3A or more bone-loss. All stems osseointegrated distally (100%). Two hips subsided >5mm but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress-shielding. One stem fractured near its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design.

Excellent results and minimal complications of total hip arthroplasty in sickle cell hemoglobinopathy at mid-term follow-up using cementless prosthetic components.

The purpose of this study was to compare the outcomes of cementless primary total hip arthroplasty (THA) in sickle cell patients compared to the remaining cohort of osteonecrosis patients who did not have this disease. Thirty-two sickle cell patients (42 hips) who had a mean age of 37 years and mean follow-up of 7.5 years (range, 5-11 years) were compared to 87 non-sickle cell osteonecrosis patients (102 hips) who had mean age of 43 years and mean follow-up of 7 years (range, 3-10.5 years). Outcomes evaluated included implant survivorship, Harris hip scores, complication rates, radiographic outcomes, and Short Form-(SF-36) health questionnaire. There were no significant differences in aseptic implant survivorship (95 vs. 97%), Harris hip scores (87 vs. 88 points), SF-36 score, or radiographic findings between the two patient cohorts. In light of these findings, we believe that the outcomes of THA improved in sickle cell patients with optimized medical management and the use of cementless prosthetic devices.

Outcomes of primary total hip arthroplasty in systemic lupus erythematosus with a proximally-coated cementless stem.

The purpose of this study was to compare the outcomes of total hip arthroplasty (THA) in systemic lupus erythematosus (SLE) compared to a cohort of osteonecrosis patients who did not have this disease. Between 2001 and 2008, 60 THAs in 44 SLE patients who had a mean age of 42 years (range, 18 to 87 years) and a mean follow-up of 7 years (range, 4 to 11 years) were evaluated. These SLE patients were compared to a cohort of 82 THAs in 70 osteonecrosis patients who did not have this disease. Outcomes evaluated included implant survivorship, Harris hip scores, complications, as well as radiographic results. There was no significant difference in implant survivorship (98% vs. 97.5%), Harris hip score (87 vs. 88 points) and complications (1.7% versus 2.4%) between the SLE and the comparison cohort. The authors believe that SLE does not negatively affect the outcomes of primary total hip arthroplasty at mid-term follow-up.

Management of failed trochanteric fracture fixation with cementless modular hip arthroplasty using a distally fixing stem.

Failure of internal fixation of intertrochanteric fractures is associated with delayed union or malunion resulting in persistent pain and diminished function. We evaluated 15 elderly patients treated with a tapered, fluted, modular, distally fixing cementless stem. At an average follow-up of 2.86 years, mean Harris hip score improved from 35.90 preoperatively to 83.01 (P < .01). Fourteen stems had stable bony on growth, and one stem was loose. Distal fixation with a tapered, fluted, modular cementless stem allows stable fixation with good functional outcome in a reproducible fashion in this challenging cohort of patients.

Patterns of osseointegration and remodeling in femoral revision with bone loss using modular, tapered, fluted, titanium stems.

Radiographic signs of osseointegration with the use of fluted, tapered, modular, titanium stems in revision hip arthroplasty with bone loss have not been previously categorized. Serial radiographs of 64 consecutive hips with mean follow-up of 6.2 years were retrospectively reviewed. Bone loss was classified as per Paprosky classification, osseointegration was assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Seventy-four percent of the hips had type 3 or 4 bone loss. All stems were radiographically osseointegrated. Early minor subsidence was seen in 6.2% of the hips; definite bony regeneration, 73% of the hips; and stress shielding, 26% of the hips. These osseointegration patterns were different from those described for extensively porous-coated cobalt-chromium stems and had a bearing on the evaluation of fixation of these stems.

Annual Nationwide Infection Trends for Revision Total Knee Arthroplasty.

Several recent intraoperative and wound management techniques have been developed and implemented in the United States over the past decade; however, it is unclear what the effects of these newer modalities have on reducing surgical site infection (SSI) rates. Therefore, the purpose of this study was to track the annual rate and trends of (1) overall, (2) deep, and (3) superficial SSIs following revision total knee arthroplasty (TKA). The National Surgical Quality Improvement Program database was queried for all revision TKA cases performed between 2011 and 2016, which yielded 9,887 cases. Cases with superficial and/or deep SSIs were analyzed separately and then combined to evaluate overall SSI rates. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 5 years. Correlation coefficients and chi-square tests were used to determine correlation and statistical significance. No significant correlations between combined, deep, and/or superficial SSI rates and year were noted (p > 0.05). The lowest overall SSI incidence was in 2012 (1.16%), while the greatest incidence was in 2014 (1.76%). The deep SSI incidence over the 6 years was 0.67% (66 out of 9,887 cases). Deep SSI rate decreased by 10% in 2016 compared with 2011 (0.50 vs. 0.56%, p > 0.05). In this 6-year period, 94 cases out of 9,887 were complicated by a superficial SSI, an incidence of 0.95%. The lowest superficial SSI incidence occurred in 2015 (n = 17, 0.77%). Overall, the incidence of SSIs in revision TKA has remained fairly low with some annual variance, indicating room for improvement. These variations likely as revision surgeries can be more complex and have several associated confounding factors influencing outcomes, when compared with primary cases. Further research is needed to identify revision-specific strategies to reduce the risk of surgical site infections.

Revision total hip arthroplasty for ceramic head fracture: a long-term follow-up.

The results of revision total hip arthroplasty (THA) for ceramic head fracture have generally been disappointing, largely due to third body wear after incomplete synovectomy. We have followed 8 patients who sustained ceramic head fractures and were subsequently revised to a metal-on-polyethylene articulation. There were no revisions for osteolysis or aseptic loosening at a mean follow-up of 10.5 years. The yearly wear rates of each of 5 of these THAs after revision were compared with 6 matched metal-on-polyethylene THAs; there were no significant differences in wear rates. Greater than 10-year survivorship with a metal-on-polyethylene bearing couple is possible after revision THA for a ceramic head fracture if a complete and thorough synovectomy can be performed. Our technique of synovectomy will be described.

Two-year to five-year follow-up of femoral defects in femoral revision treated with the link MP modular stem.

Femoral deficiency has been shown to adversely affect the results of revision total hip arthroplasty. Tapered titanium modular stems allow distal fixation of the fluted, conical portion of the implant in the setting of proximal bone loss. One hundred two consecutive hips with proximal bone loss underwent revision femoral reconstruction between 1998 and 2002 at 3 centers using the Link MP modular stem. Forty-three hips had Mallory type 3C femoral deficiency. Ninety-seven hips were observed for an average of 45 months (range, 24-72; median, 36 months). Clinically, mean Harris hip score improved from 36 to 84 (range, 54-99). Radiographically, 93 hips were considered stable, with no circumferential lucencies at the distal fixation surface. Three hips migrated and required revision, along with one periprosthetic fracture. Five other hips had nonprogressive migration of 1 to 2 mm.

Proposed frequencies of a vibrator used for implant retrieval at the time of hip joint revision surgery.

The number and the rate of success of hip implantation surgeries have increased significantly during last thirty years, not only in the USA, but also throughout the world. It has been reported that the failure rates of implanted hip joints are less than 8% after 10 years, and less than 20% after twenty years. Failures occur directly or indirectly due to wear, stress shielding and infection. Revision surgery is needed for those failed implant replacements. In the future, as the elderly population increases, the frequency of this type of revision surgery will also increase. At the time of revision surgery, removal of the existing cemented femoral implant can be a problem for the surgeon. Use of a vibrator for loosening of the existing cement layer between the bone and the implant may be a helpful solution. In this study, we investigated the optimum resonance frequencies of such a vibrator that might be used to loosen the cement layer easily and efficiently. Natural frequencies of different-sized implants and of different materials were determined. For harmonic analysis, CT scan data of a femur was processed in the image processing software MIMICS. Then the outline of the total hip was modeled and was analyzed by the finite element software ANSYS. The required portion of the femoral part was edited, implant and cement layer were introduced in that model, and elements were generated in that FEA software. Then elements of the femoral part, except the cement layer and the implant, were sent to MIMICS software again for assignment of different Youngs modulus of each element, which are proportionate to their densities. Then the elements were brought back to the FEA software. The harmonic analysis was performed for the total model in the FEA software ANSYS. For that particular boundary condition, the first three natural frequencies of the three types of implant sizes and materials varied by a maximum of 7-8%. Results of the numerical harmonic analysis showed that at the bone-cement interface, the resonance frequencies were at the ranges of 4 to 6 Hz, 26 to 29 Hz, and 43 to 49 Hz. The vibration response was similar for three cement-bone interface locations examined. This suggests that a vibrator that will produce a resonance frequency response may cause cracks in the bone-cement mantle and thus may facilitate the removal of the failed femoral component. Retrieval of hip implant may be easier using a vibrator in that band of frequencies with a moderate amplitude. The magnitude of those frequencies may not differ significantly from implant to implant as the natural frequencies of different types of implant, for that particular boundary conditions, are within a close range.

Periarticular injection and continuous femoral nerve block versus continuous femoral nerve block alone on postoperative opioid consumption and pain control following total knee arthroplasty: Randomized controlled trial.

Continuous femoral nerve block (CFNB) has been used to prevent the breakthrough pain after total knee arthroplasty (TKA). Multimodal drug injection (PMDI) has also been shown to decrease opioid consumption and pain. We investigated whether the use of PMDI further improves analgesic and rehabilitation outcomes when used in conjunction with CFNB. This is a prospective randomized controlled study of 44 patients undergoing primary TKA. The treatment group (n = 23) received a PMDI of combined ropivacaine, epinephrine, ketorolac and morphine, and the controlled group (n = 21) received saline at wound closure. Total opioid consumption, pain scores, knee range of motion (ROM) outcomes, length of stay, and patient satisfaction were measured and compared. The total consumption of morphine is similar between the two groups (52.6 ± 40.6 vs. 41.5 ± 32.9, p = 0.325). The mean morphine consumption of the treatment group was significantly lower than the control at 4 h after surgery (4.2 ± 5.5 vs. 11.3 ± 8.1, p = 0.002) but comparable on POD1, POD2, and POD3. The mean pain scores were significantly higher in the treatment group than the control group at POD2 (at rest: 47.3 ± 29.1 vs. 23.8 ± 20.6, p = 0.004; after PT: 57.7 ± 25.4 vs. 35.2 ± 26.8, p = 0.007) and POD3 (at rest: 30.9 ± 30.3 vs. 14.8 ± 20.9, p = 0.045; after PT: 50.2 ± 30.6 vs. 29.0 ± 32.1, p = 0.035), and not significantly different at 4 h after surgery or at POD1. Mean maximal knee flexion ROM in degrees during active and active assisted mobilization showed no significant difference between the control and the treatment groups on POD2 and POD3. The mean length of stay of the treatment group is significantly longer than the control group (5.1 ± 2.1 vs. 3.8 ± 1.6, p = 0.032). At discharge, no significant difference exists between the two groups for mean patient satisfaction. The addition of PMDI led to a decrease in opioid consumption in the immediate postoperative period but with no significant difference in the total consumption within the first three days postoperatively. This finding provides an opportunity for appropriate preoperative treatment and education for both patients and caregivers.

The effect of operative time on in-hospital length of stay in revision total knee arthroplasty.

BACKGROUND: Revision total knee arthroplasty (TKA) is associated with increased rates of infections, readmissions, longer operative times, and lengths-of-stay (LOS) compared to primary TKA. Additionally, increasing operative times and prolonged postoperative LOS are independent risk factors for these postoperative complications in lower extremity total joint arthroplasty (TJA). This has led to an increased effort to reduce these risk factors in order to improve patient outcomes and reduce cost. However, the relationship between operative time and LOS has not been well assessed in revision arthroplasty. Therefore, the purpose of this study was to: (I) identify predictors of longer operative times; (II) identify predictors of longer LOS; and (III) evaluate the effects of operative time, treated as both a categorical variable and a continuous variable, on LOS after revision TKA. METHODS: The NSQIP database was queried for all revision TKA cases (CPT code 27487) between 2008 and 2016 which yielded 10,604 cases. Mean operative times were compared between patient demographics including age groups, sex, and body mass indexes (BMIs). To determine predictors of LOS, mean LOS were also compared between patient demographics in the same groups. To assess the correlation of operative time on LOS, the mean LOS for 30-minute operative time intervals were compared. Univariate analysis was performed with one-way analysis of variance (ANOVA) and t-tests. A multivariate analysis with a multiple linear regression model was performed to evaluate the association of LOS with operative times after adjusting for patient age, sex, and BMI. RESULTS: The mean LOS for revision TKA was 4 (±3) days. Further analysis showed that young age is associated with increased LOS (P<0.01). An analysis of operative times showed positive correlations with young age, BMI greater than 30 and male sex (P<0.05). The mean LOS of revision TKA patients was found to increase with increasing operative time in 30-minute intervals (P<0.001). Multivariate analysis showed that longer operative times had significant associations with longer LOS even after adjusting for patient factors (ß=0.102, SE =0.001, P<0.001). These results also showed that out of all of the study covariates, operative times had the greatest effect on LOS after revision TKA. CONCLUSIONS: Revision TKA is a complex procedure, often requiring increased operative times compared to primary TKA. This study provides unique insight by correlating operative times to LOS in over 10,000 revision TKAs from a nationwide database. Our results demonstrate that out of all the study covariates (age, sex, and BMI), operative times had the greatest effect on LOS. The results from this study indicate that less time spent in the operating room can lead to shorter LOS for revision TKA patients. This relationship further underscores the need for improved preoperative planning and intra-operative efficiency in an effort to decrease LOS and improve patient outcomes.

A 6-year trends analysis of infections after revision total hip arthroplasty.

BACKGROUND: Substantial efforts have been made to reduce the risk of infection after total hip arthroplasty (THA), including pre-operative patient optimization, skin preparation with alcohol-based solutions, perioperative antibiotics, and minimizing wound drainage with novel sutures and dressings. While these approaches have been effective in primary THA, their effects on revision THA to improve surgical site infection (SSI) rates are less clear. Therefore, the purpose of this study was to identify the annual rates and trends of: (I) overall; (II) deep; and (III) superficial SSIs following revision THA using the most recent results (2011 to 2016) from a large, nationwide database. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for all revision THA cases (CPT code 27134) between 2011 and 2016, yielding 8,562 cases. A steady increase in the total number of revision THA cases was observed from 2011 to 2016 (750 vs. 1,951, 260%). Cases with reported superficial and/or deep SSI were analyzed separately and then combined to evaluate overall SSI rates. The infection incidence for each year was calculated. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with each of the preceding 5 years. Additionally, percent differences between 2016 and each previous year were calculated to evaluate rate changes. Pearson correlation coefficients and chi-squared tests were used to determine correlation and statistical significance which was maintained at a P value less than 0.05. RESULTS: There were 217 cases out of 8,562 (2.53% of all cases) complicated by any SSI. Overall, there was an inverse correlation between combined SSI rate and year, however, this was not statistically significant (P>0.05). The lowest incidence was in 2016 (n=41, 2.10%), while the highest incidence was in 2014 (n=45, 2.86%). The combined SSI rate in 2016 decreased by 22% when compared to 2015 (2.10% vs. 2.69%, P>0.05). A larger, 27% decrease in rate was found between 2016 and 2014 (2.10% vs. 2.86%, P>0.05). For deep SSI, there was an inverse correlation between rate and year of surgery, however, this was not statistically significant (P>0.05). The deep SSI incidence over the 5 years was 1.38% (118 out of 8,562 cases). There was a 35% decrease in deep SSI rate from 2016 to 2015 (0.92% vs. 1.43%, P>0.05). A larger, 53% decrease, was seen between 2016 and 2014 (0.92% vs. 1.04%, P<0.01). For superficial SSI, there was an inverse correlation between rate and year, however, this was not statistically significant (P>0.05). In this 6-year period, 99 cases out of 8,562 were complicated by a superficial SSI; an incidence of 1.16%. The lowest incidence occurred in 2014 (n=14, 0.89%), while 2012 had the highest incidence (n=17, 1.61%). The rate in 2016 decreased by 6% when compared to 2015 (1.18% vs. 1.07%, P>0.05). A larger, 27% decrease in rate was observed between 2016 and 2012 (1.18% vs. 1.61%, P>0.05). CONCLUSIONS: Revision total hip arthroplasties exhibited a trend towards decreasing overall SSI nationwide between 2011 and 2016. Deep SSI rates had marked improvements, specifically between 2014 and 2016. This trend indicates some benefit from pre- and post-operative infection preventative strategies, but importantly, indicates continued room for improvement. Due to the potentially devastating complications associated with infection in revision THAs, further research is required to identify revision-specific strategies to lower the rates of SSIs.