Efficacy and Safety of a Patient Selection Tool for Predicted Discharge at an Ambulatory Surgical Center: A Pilot Study.

Background: There is a paucity of validated risk stratification tools to assess which patients can safely and predictably undergo outpatient total hip (THA) or knee arthroplasty (TKA) in an ambulatory surgery center (ASC). Methods: Our novel patient selection tool was prospectively applied to 190 consecutive primary THA and TKA performed by a single surgeon at a single ASC. We identified the proportion of patients discharged home the same day, those requiring a one-night stay, or those with failed discharge within 23 hours. A retrospective chart review was performed to determine if any demographic parameters were risk factors for an overnight stay. Results: Overall, 190 (100%) patients selected for outpatient THA and TKA were discharged home within 23 hours. One hundred and four patients (55%) were discharged the same day of surgery, whereas 86 (45%) required overnight stay and were discharged on postoperative day 1. Female sex (odds ratio [OR]: 4.1, 95% confidence interval [CI]: 2.0-8.2, P < .001), THA (OR: 2.5, 95% CI: 1.1-5.5, P = .022), and heavier body mass index (OR: 1.0, 95% CI: 1.0-1.2, P = .022) were identified as independent risk factors for staying overnight in the ASC. Conclusions: In this pilot study, we found that 100% of outpatient THA and TKA-eligible patients were able to be discharged home by postoperative day 1. Additionally, we found that this selection tool is safe and effective at predicting short-stay discharge in an ASC.

One Size Does Not Fit All: Women Experience More Pain Than Men After Total Knee Arthroplasty.

INTRODUCTION: Multimodal pain regimens are universally applied to all patients, despite known differences in pain and responses to medication between patients of different sexes, ethnicities, and races. The purpose of this study was to understand the influence of patient sex on postoperative total knee arthroplasty (TKA) pain perception as well as the efficacy of perioperative pregabalin for pain control. METHODS: Visual Analog Scores (VAS) and Knee Injury and Osteoarthritis Outcome Junior (KOOS Jr.) scores were prospectively collected for 150 patients (64 men and 86 women). Mean pain scores, delta pain scores, time to achieve minimal clinically important differences (MCID), influence of pregabalin, and opioid consumption were recorded at baseline, day of surgery, 24 hours, 48 hours, and 72 hours post-operatively, as well as post-operatively weeks 1, 2, 6, 12, and 26, and compared between women and men cohorts. This study was registered on ClinicalTrials.gov (NCT04471233). RESULTS: The VAS pain scores for women were higher than for men at all study time points (P < 0.05). The change in VAS walking and mean KOOS Jr. scores from baseline to final follow-up at 26 weeks were not significantly different between cohorts. Both cohorts achieved VAS MCID by 2 weeks postoperatively. No significant differences in opioid consumption between men and women were noted during the study time periods. Women were also noted to have significantly higher raw KOOS Jr. scores than men at all time points, except for at 26 weeks post-operatively. Interim analysis revealed no significant influence of pregabalin on VAS scores, so this arm of the study was discontinued. CONCLUSION: Patient sex plays a role in perceived postoperative TKA pain, as women reported higher pain scores than men. We recommend not overly relying on standardized protocols, but rather instituting patient-specific pain management strategies.

A Novel Patient Selection Tool Is Highly Efficacious at Identifying Candidates for Outpatient Surgery When Applied to a Nonselected Cohort of Patients in a Community Hospital.

BACKGROUND: There is a paucity of validated selection tools to assess which patients can safely and predictably undergo same-day or 23-hour discharge in a community hospital. The purpose of this study was to assess the ability of our patient selection too to identify patients who are candidates for outpatient total joint arthroplasty (TJA) in a community hospital. METHODS: A retrospective review of 223 consecutive (unselected) primary TJAs was performed. The patient selection tool was retrospectively applied to this cohort to determine eligibility for outpatient arthroplasty. Utilizing length of stay and discharge disposition, we identified the proportion of patients discharged home within 23 hours. RESULTS: We found that 179 (80.1%) patients met eligibility criteria for short-stay TJA. Of the 223 patients in this study, 215 (96.4%) patients were discharged home; 17 (7.9%) were on the day of surgery, and 190 (88.3%) within 23 hours. Of the 179 eligible patients for short-stay discharge, 155 (86.6%) patients were discharged home within 23 hours. Overall, the sensitivity of the patient selection tool was 79%, the specificity was 92%, the positive predictive value was 87% and the negative predictive value was 96%. CONCLUSION: In this study, we found that more than 80% of patients undergoing TJA in a community hospital are eligible for short-stay arthroplasty with this selection tool. We found that this selection tool is safe and effective at predicting short-stay discharge. Further studies are needed to better ascertain the direct effects of these specific demographic traits on their effects on short-stay protocols.

Patient-Specific Venous Thromboembolic Event Prophylaxis in Total Joint Arthroplasty - Literature-Supported Guidelines.

Following total joint arthroplasty (TJA), venous thromboembolic events (VTE) are a known complication that may result in increased hospitalization cost as well as morbidity. Numerous investigations have documented patient-specific factors that place an individual at increased risk of VTE after TJA. Potential risk factors for VTE include genetic predisposition, history of a prior VTE event, revision surgery and patient comorbidity factors. The American Academy of Orthopedic Surgeons and The American College of Chest Physicians have both provided recommendations for VTE prophylaxis after orthopedic surgery. However, among orthopedic surgeons, there remains a lack of consensus regarding the appropriate agent and time course for prophylactic anticoagulation after TJA. In this study, we review the evidence-supported patient-specific factors that confer an increased risk of VTE in the TJA postoperative period. Furthermore, we describe the VTE prophylaxis regimen used at our home institution after TJA for low- and high-risk patients as well as a recommendation for cessation or continuation of anticoagulation regimens that patients were on preoperatively for comorbid conditions.

Understanding Patient Perspectives Regarding Remote Monitoring Devices Following Total Joint Replacement.

Background: Advances in smart technology have expanded into the field of orthopedic surgery to deliver enhanced patient care. Smart technology has also raised important issues regarding protected patient information. The purpose of this study is to determine patient preferences regarding smart technology in their postarthroplasty care. Methods: Patient surveys were administered in the office setting of 2 adult reconstructive orthopedic surgeons during a 4-week period. Surveys queried patient demographics, twelve yes/no questions, five continuous agree/disagree statements, and a single free-text question. Logistic regression and statistical significance testing were performed. Results: Of the study patients, 83.6% were willing to wear a device. Women were more likely to consent to a monitoring device and have activity data collected than men (P < .05). Younger patients were more likely to consent to a device and have data collected than octogenarians. Nearly 90% of respondents indicated peace of mind with data being constantly tracked. However, 64% of respondents had hesitations about a surgically implanted device that was independent of a previous arthroplasty surgery (P < .05). Conclusions: Patients are comfortable with smart technology being involved in their postoperative care, especially younger patients and women. Older individuals, possibly with less experience using smart technology in their lives, were not as willing to wear smart devices or have their data collected. Nearly two-thirds of patients had hesitations about surgically implanted smart devices. Further investigation is needed to understand hesitations concerning smart implants as the orthopedic community enters an era of commercially available smart implants in total joint arthroplasty.

Does Time Spent in the Post-Anesthesia Care Unit Affect Hospital Lengths of Stay following Primary Total Knee Arthroplasty?

Given the current healthcare economic environment, substantial efforts have been made to help streamline the in-hospital care for total knee arthroplasty (TKA) patients. While potential cost-reducing factors have been identified in the literature, analyses specifically considering post-anesthesia care unit (PACU) lengths of stay (LOS) are lacking. Therefore, the purpose of this study was to identify factors associated with (1) longer PACU LOS as well as (2) longer Hospital LOS. Prospectively collected TKA data from seven participating hospitals within a large health system were evaluated for patient demographics, body mass indices, Charlson Comorbidity Indices (CCI), surgeon volumes/training, admission types, anesthesia types, PACU LOS, and overall hospital LOS. Complete data was available for 1,690 patients (1,082 females, mean age: 67 years). Univariate and multivariate analytical models were constructed to identify which factors were predictive of longer PACU and overall hospital LOS. Same-day admissions, higher volume surgeons (≥ 100 cases per year), fellowship-trained arthroplasty surgeons, and longer operative times were associated with longer PACU LOS (p < 0.05). Multivariate analyses found age more than or equal to 65 years (ß= 0.124) and CCI more than or equal to 3 (ß= 0.088) to be associated with longer hospital LOS (p < 0.001). Operative times, PACU LOS, and procedure times (operative time plus PACU LOS) were not associated with longer hospital LOS (p > 0.05). These data identify associative factors for PACU LOS, as well as the influence of time spent in the PACU on overall hospital LOS. Interestingly, this analysis revealed that patients of arthroplasty fellowship-trained and higher-volume surgeons had longer PACU LOS; however, this could be explained by the observation that these particular surgeons tend to perform more complex deformity cases. Also of importance, increased PACU LOS, meaning the patient spent more time in a high-monitored setting immediately after surgery, did not necessarily confer a longer overall hospital LOS. Based on these data, it may be more beneficial to identify alternate sources than time spent in the operating room or PACU to potentially help reduce overall hospital LOS. LEVEL OF EVIDENCE: II, prospective cohort.

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.

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.

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.

Identifying Reasons for Failed Same-Day Discharge Following Primary Total Hip Arthroplasty.

BACKGROUND: As total hip arthroplasty (THA) gains popularity in ambulatory surgery centers, it is important to understand the causes of failed same-day discharge (SDD). The purpose of this study is to (1) identify reasons for an overnight stay among patients selected as candidates for SDD following THA and (2) determine what pre-operative factors are more common among patients who fail SDD. METHODS: This is a prospective cohort study of patients undergoing THA who were identified as candidates for SDD (<75 years, ambulate without walker, American Society of Anesthesiologists score 1-3, body mass index <40 kg/m2, and agreed to SDD pre-operatively). The primary outcome was the reason for not discharging home on the same day of surgery. Secondary outcomes included the proportion of patients who failed SDD and any pre-operative patient characteristics that could be linked to failed SDD. RESULTS: Seventy-eight of 106 (74%) patients pre-selected for SDD were successfully discharged per protocol. Of the 28 (26%) patients who failed SDD, the most common reasons for failure were patient preference (12), dizziness or hypotension (8), failure to clear physical therapy (5), urinary retention (2), and pain management (1). There was a higher percentage of patients in the failed SDD group who reported multiple allergies (P = .02), anxiety/depression (P = .24), obstructive sleep apnea (P = .38), and rheumatoid arthritis (P = .02). CONCLUSION: SDD is a viable option for surgeons interested in rapid recovery THA. In a pool of patients selected for SDD, the main cause of SDD failure was a change in patient preference post-operatively, despite having agreed to SDD pre-operatively and meeting all discharge criteria.

Risk factors for conversion surgery to total hip arthroplasty of a hemiarthroplasty performed for a femoral neck fracture.

INTRODUCTION: The purpose of this study was to determine risk factors for conversion to total hip arthroplasty (THA) in patients originally treated with hemiarthroplasty (HA) for displaced femoral neck fractures. METHODS: In this case-controlled study, we identified 54 patients who were treated with HA for femoral neck fracture (FNF) who subsequently underwent conversion to THA at our institution between 2003 and 2013. We randomly selected 142 control patients who underwent HA for a displaced FNF without conversion surgery during the same time period. We compared demographic data, implant parameters, and radiographic data between the groups to identify risk factors for conversion surgery. RESULTS: In the univariate analysis, younger age at index surgery (mean 75 vs. 80 years, p = 0.006), higher body mass index (26.1 vs. 23.7, p = 0.031), bipolar prosthesis (20% vs. 36%, p = 0.024), absence of dementia (6% vs. 23%, p = 0.01), increased leg length compared to contralateral limb (6.5 mm vs. 0.2 mm, p<0.001), and increased HA femoral head size compared to the contralateral femoral head (2.7 mm vs. 1.5 mm, p = 0.02) were associated with a significantly increased risk of conversion surgery. In the multivariate logistic regression, decreased age at index surgery, no dementia, use of a bipolar head, and increased leg length discrepancy (LLD) were associated with risk of conversion. CONCLUSIONS: Patient characteristics, including younger age, increased BMI, and absence of dementia can lead to increased risk for conversion of HA to THA. Intraoperative considerations of head size and increase in ipsilateral LLD may increase the risk of conversion surgery. These factors should be considered by surgeons who employ HA for displaced FNFs.

Tranexamic acid increases early perioperative functional outcomes after total knee arthroplasty.

BACKGROUND: The purpose of this study was to investigate the influence of tranexamic acid (TXA) on functional outcomes in the immediate postoperative period after total knee arthroplasty (TKA). We hypothesized that the known benefits of TXA would confer measurable clinical improvements in physical therapy (PT) performance, decrease pain, and decrease hospital length of stay (LOS). METHODS: We retrospectively analyzed 560 TKA patients, including 280 consecutive patients whose surgery was performed before the initiation of a standardized TXA protocol and the first 280 patients who received TXA after protocol initiation. Outcome measurements included postoperative changes in hemoglobin and hematocrit, LOS, pain scores, destination of discharge, and steps ambulated with PT over 5 sessions. RESULTS: TXA administration resulted in less overall drops in hemoglobin (P < .001) and hematocrit levels (P < .001). Moreover, patients administered TXA ambulated more than their counterparts during every PT session, which was statistically significant during the second (P = .010), third (P = .011), and fourth (P = .024) sessions. On average, the TXA cohort ambulated 20% more per PT session than patients who did not receive TXA (P < .001). TXA administration did not influence pain levels during PT, hospital LOS, or discharge destination in this investigation. CONCLUSIONS: It is well known that TXA reduces postoperative anemia, but this study also demonstrates that it confers early perioperative functional benefits for TKA patients. Potential mechanisms for this benefit include reduced rates of postoperative anemia and reduced rates of hemarthroses.

Periarticular Ropivacaine Cocktail Is Equivalent to Liposomal Bupivacaine Cocktail in Bilateral Total Knee Arthroplasty.

BACKGROUND: This study compares the effectiveness of 2 commonly used periarticular injection formulations: liposomal bupivacaine and bupivacaine (EXP) and ropivacaine, epinephrine, ketorolac, and clonidine (ROP) in patients undergoing bilateral total knee arthroplasty or unicompartmental knee arthroplasty. METHODS: Twenty-six total knee arthroplasty patients (52 knees) and 3 unicompartmental knee arthroplasty patients (6 knees) undergoing simultaneous, bilateral arthroplasty were randomized to receive periarticular injections in a blinded fashion. Even birth year patients were selected for PAI of EXP in the right knee and ROP in the left knee. This was reversed for odd birth years. Visual analog scale pain scores for each knee and patient perceived difference in knee functional recovery were recorded during physical therapy, throughout the hospitalization. RESULTS: There was no difference in visual analog scale pain scores between the EXP and ROP injected knees at any time point during the first 2 days after surgery. Postoperative pain scores averaged 41.9 mm (range 0-100 mm) for EXP and 43.1 mm (range 0-100 mm) for ROP. Patients were unable to detect a difference in the functional recovery between their knees on postoperative day 0, 1, or 2. No complications as a result of either periarticular injection occurred. CONCLUSION: Periarticular injections of EXP and ROP are equally effective after knee arthroplasty and patients do not appreciate differences between knees as determined by pain score or perceived functional recovery during the first 2 days after bilateral knee arthroplasty. This study demonstrates that a liposomal bupivacaine injection does not add an incremental benefit for pain control compared to a less expensive injection formulation.

Arthroscopic Wrist Debridement and Radial Styloidectomy for Advanced Scapholunate Advanced Collapse Wrist: Long-term Follow-up.

BACKGROUND: Symptomatic stage 2 or 3 scapholunate advanced collapse (SLAC) wrist is aggressively treated with salvage procedures, such as proximal row carpectomy or partial wrist fusion with resultant pain relief but limited motion. We hypothesize that arthroscopic synovectomy, radial styloidectomy, and neurectomy will preserve wrist motion, relieve pain, and delay or avoid salvage procedures. METHODS: We evaluated outcomes in 13 wrists through questionnaires and 11 of these through additional physical examination at a mean follow-up of 5.0 years. Eight wrists were stage 2 and 5 were stage 3. Data at final follow-up included mobility/strength measurements, subjective outcome scores (Disabilities of the Arm, Shoulder, and Hand [DASH] and visual analog scale [VAS] pain), patient satisfaction, and return to work statistics. RESULTS: Patients had an average flexion-extension arc of 88.0° in the treated wrist and an average grip strength that was 95.0% of the contralateral side. No patients required revision surgery at follow-up. The 13 wrists reported an average DASH score of 16.4 and mean VAS pain score at rest and with activity of 17.9 and 31.6, respectively. All patients working prior to the procedure (n = 8) were able to immediately return to work. In all, 84.6% of patients were satisfied. CONCLUSIONS: The procedure studied may have advantages in relieving pain, while preserving wrist motion for SLAC stage 2 or 3 disease. This procedure does not preclude future salvage procedures in those patients with severe disease who prefer to maintain wrist motion for the short term. Patients experience good functional outcomes with the majority experiencing a reduction in pain with the ability to return to work.

Risk factors for conversion surgery to total hip arthroplasty of a hemiarthroplasty performed for a femoral neck fracture.

INTRODUCTION: The purpose of this study was to determine risk factors for conversion to total hip arthroplasty (THA) in patients originally treated with hemiarthroplasty (HA) for displaced femoral neck fractures. METHODS: In this case-controlled study, we identified 54 patients who were treated with HA for femoral neck fracture (FNF) who subsequently underwent conversion to THA at our institution between 2003 and 2013. We randomly selected 142 control patients who underwent HA for a displaced FNF without conversion surgery during the same time period. We compared demographic data, implant parameters, and radiographic data between the groups to identify risk factors for conversion surgery. RESULTS: In the univariate analysis, younger age at index surgery (mean 75 vs. 80 years, p = 0.006), higher body mass index (26.1 vs. 23.7, p = 0.031), bipolar prosthesis (20% vs. 36%, p = 0.024), absence of dementia (6% vs. 23%, p = 0.01), increased leg length compared to contralateral limb (6.5 mm vs. 0.2 mm, p<0.001), and increased HA femoral head size compared to the contralateral femoral head (2.7 mm vs. 1.5 mm, p = 0.02) were associated with a significantly increased risk of conversion surgery. In the multivariate logistic regression, decreased age at index surgery, no dementia, use of a bipolar head, and increased leg length discrepancy (LLD) were associated with risk of conversion. CONCLUSIONS: Patient characteristics, including younger age, increased BMI, and absence of dementia can lead to increased risk for conversion of HA to THA. Intraoperative considerations of head size and increase in ipsilateral LLD may increase the risk of conversion surgery. These factors should be considered by surgeons who employ HA for displaced FNFs.

Hemiarthroplasty for Displaced Femoral Neck Fractures in the Elderly Has a Low Conversion Rate.

BACKGROUND: Hemiarthroplasty (HA) has been a mainstay treatment for displaced femoral neck fractures for many years. The purpose of this study was to report the conversion rate of HA to total hip arthroplasty (THA) for displaced femoral neck fractures and compare outcomes between implant constructs (bipolar vs unipolar), fixation options (cemented vs cementless stems), and age groups (<75 years vs ≥75 years). METHODS: We retrospectively reviewed the results of a consecutive cohort of 686 patients who underwent HA for the treatment of femoral neck fractures at our institution between 1999 and 2013 with a minimum of 2-year follow-up. RESULTS: The overall component revision rate, including conversion to THA, revision HA, revision with open reduction internal fixation, and Girdlestone procedure, was 5.6% (39/686). Seventeen patients (2.5%) were converted from HA to THA at an average of 1.9 years after index procedure. A significantly lower conversion rate of 1.4% (7/499 patients) was found in the older patient cohort (≥75 years old) compared to 5.3% (11/187) in the younger cohort. The most common causes for conversion surgery to THA were acetabular wear (5 patients), aseptic loosening (4 patients), and periprosthetic fracture (3 patients). There was a significantly lower rate of periprosthetic fracture (0.4% vs 2.5%, P value .025) in the cemented implant group compared to the cementless group. We observed a higher rate of dislocations in the bipolar vs unipolar group (3.8% vs 1%, P value .02) and no other significant differences between these groups. CONCLUSION: We observed a low reoperation rate for this cohort of patients, relatively higher conversion rates for the younger population, fewer periprosthetic fractures with the use of cemented stems, and no advantage of bipolar over unipolar prostheses.

The Combination of the Tunnel View and Weight-Bearing Anteroposterior Radiographs Improves the Detection of Knee Arthritis.

Imaging used for the evaluation of knee pain has historically included weight-bearing anteroposterior (AP), lateral, and sunrise radiographs. We wished to evaluate the utility of adding the weight-bearing (WB) posteroanterior (PA) view of the knee in flexion. We hypothesize that (1) the WB tunnel view can detect radiographic osteoarthritis (OA) not visualized on the WB AP, (2) the combination of the AP and tunnel view increases the radiographic detection of OA, and (3) this may provide additional information to the clinician evaluating knee pain. We retrospectively reviewed the WB AP and tunnel view radiographs of 100 knees (74 patients) presenting with knee pain and analyzed for evidence of arthritis. The combination of the WB tunnel view and WB AP significantly increased the detection of joint space narrowing in the lateral (p < 0.001) and medial (p = 0.006) compartments over the AP view alone. The combined views significantly improved the identification of medial subchondral cysts (p = 0.022), sclerosis of the lateral tibial plateau (p = 0.041), and moderate-to-large osteophytes in the medial compartment (p = 0.012), intercondylar notch (p < 0.001), and tibial spine (p < 0.001). The WB tunnel view is an effective tool to provide additional information on affected compartments in the painful knee, not provided by the AP image alone.

The Cemented Unipolar Prosthesis for the Management of Displaced Femoral Neck Fractures in the Dependent Osteopenic Elderly.

BACKGROUND: Significant variability exists across orthopedic surgeons in the management of the displaced femoral neck fracture in the elderly patient (>75 years old). These patients tend to be less healthy, have inferior bone quality, and gait instability leading to increased risk of periprosthetic fracture, compromised implant fixation, dislocation, and need for revision. The surgeon's goals should be to restore mobility while eliminating pain and need for reoperation. METHODS: In this review article, we examine the best available evidence in the literature to determine which strategy achieves optimal outcomes. We examine outcome studies comparing use of hemiarthroplasty and total hip arthroplasty, unipolar and bipolar hemiarthroplasty, and cemented vs cementless fixation of femoral stems. RESULTS AND CONCLUSIONS: For the active, healthy, and lucid patient, or one who has preexisting groin pain, who sustains a displaced femoral neck fracture, the literature supports a total hip arthroplasty. Patients sustaining a displaced femoral neck fracture and who are less active, have decreased bone mass, and are at increased risk of falls would benefit most from a device that optimally balances the need for revision surgery, restores ambulation, and eliminates pain. Thus, the current evidence favors cemented, unipolar hemiarthroplasty for the dependent osteopenic elderly patient with a displaced femoral neck fracture.

Tibial baseplate positioning in robotic-assisted and conventional unicompartmental knee arthroplasty.

This study compared tibial baseplate alignment (TBA) between robotic-arm-assisted (RAA) and conventional (CONV) unicompartmental knee arthroplasties (UKAs). We hypothesized that RAA would increase the percentage of implants within a predetermined safe zone (SZ). We identified 177 CONV and 87 RAA UKAs through our center's patient registry. Two individuals reviewed postoperative knee radiographs and determined TBA. Coronal baseplate positioning was more accurate (i.e., within the SZ) for RAA (2.6° ± 1.5° vs. 3.9° ± 2.4°, p < 0. 0001). Conversely, sagittal alignment was more accurate for CONV (4.9° ± 2.8° vs. 2.4° ± 1.6°, p < 0.0001). RAA was more precise in both planes (p < 0.0001). There was no difference in the percentage of implants within the SZ between the two groups (p = 1.0).

Redefining the Acetabular Component Safe Zone for Posterior Approach Total Hip Arthroplasty.

BACKGROUND: Acetabular component orientation influences joint stability in total hip arthroplasty (THA). The purpose of this study was to evaluate the effect of cup orientation and other variables on hip dislocation risk and to define a posterior approach specific safe zone. METHODS: A cohort of 1289 posterior approach primary THA cases was prospectively followed and component position measured radiographically. RESULTS: Cup malposition, with respect to the Lewinnek safe zone, was an independent risk factor for dislocation (OR1.88). Modifying the anteversion safe zone limits to 10-25° strongly predicted increased dislocation risk (OR2.69). No dislocations occurred within a zone defined by a circle centered at 41.4° abduction and 17.1° anteversion, radius 4.3°. CONCLUSION: Utilizing a posterior approach specific safe zone of 10-25° anteversion and 30-50° abduction may minimize THA dislocations. LEVEL OF EVIDENCE: Level III.