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Physicians utilize P-values to interpret clinical trial data and guide patient-care decisions. Fragility analysis assesses the stability of statistical findings in relation to outcome event reversals. This study assessed the statistical fragility of recent randomized controlled trials (RCTs) investigating tourniquet use in total knee arthroplasty (TKA).We queried PubMed, EMBASE, and MEDLINE for RCTs comparing outcomes in TKA based on tourniquet use. Fragility index (FI) and reverse fragility index (reverse FI) were calculated - for significant and nonsignificant outcomes, respectively - as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) was calculated by dividing the FI or reverse FI by the sample size. Median overall FI and FQ were calculated for all included outcomes, and sub-analyses were performed by reported significance. The literature search yielded 23 studies reporting 91 total dichotomous outcomes.Overall median FI was 4 with an interquartile range (IQR) of 3 to 6. Overall median FQ was 0.0476 (IQR 0.0291 to 0.0867). A total of 11 outcomes were statistically significant with a median FI and FQ of 2 (IQR 1.5 to 5) and 0.0200 (IQR 0.0148 to 0.0484), respectively. There were 80 outcomes that were nonsignificant with a median reverse FI of 4 (IQR 3 to 6). Loss to follow-up was greater than the median FI in 17.6% of outcomes.Altering a small number of outcomes is often sufficient to reverse findings in RCTs evaluating tourniquet use in TKA. We recommend including fragility analyses to increase reliability in the interpretation of study conclusions.

Prosthetic joint infection (PJI) following unicompartmental knee arthroplasty (UKA) is a rare but challenging complication. A paucity of literature exists regarding the management of PJI in UKA. This systematic review aims to assess current treatment patterns in UKA PJI and analyze the failure rates associated with treatment.PubMed, Scopus, and EMBASE were systematically searched for studies that presented cases of PJI following UKA. Data regarding study design, country of publication, index procedure type, diagnosis of PJI, number and incidence of PJI, timing of PJI (acute versus chronic), treatment, and outcomes were recorded. Failure rates in acute and chronic PJI as well as total failure rates were analyzed.Sixteen articles were identified that met inclusion criteria. These included 97 PJI cases (37 acute, 58 chronic, 2 unknown timing); incidence across all studies of 0.80%. The most common treatment for all PJI cases was debridement, antibiotics, and implant retention (DAIR) (40.2%), followed by two-stage conversion to total knee arthroplasty (TKA) (33.0%), one-stage conversion to TKA (23.7%), and one-stage exchange UKA (3.1%). There were no significant differences in failure rates across procedures for acute, chronic or overall PJI management (p 0.05 for all).This systematic review found relatively few studies reporting on PJI after UKA compared to the available TKA evidence. Further research is warranted to better elucidate the most appropriate treatment of PJI after UKA in both the acute and chronic setting along with risk factors for failure.

Despite the extensive literature on racial disparities in care and outcomes after total knee arthroplasty (TKA), data on manipulation under anesthesia (MUA) is lacking. We aimed to determine (1) the relationship between race and rate of (and time to) MUA after TKA, and (2) annual trends in racial differences in MUA from 2013 to 2018.This retrospective cohort study (using 2013-2018 Medicare Limited Data Set claims data) included 836,054 primary TKA patients. The primary outcome was MUA1 year after TKA; time from TKA to MUA in days was also recorded. A mixed-effects multivariable model measured the association between race (White, Black, Other) and odds of MUA. Odds ratios (OR) and 95% confidence intervals (CI) were reported. A Cochran Armitage Trend test was conducted to assess MUA trends over time, stratified by race.MUA after TKA occurred in 1.7%, 3.2% and 2.1% of White, Black, and Other race categories, respectively (SMD = 0.07). After adjustment for covariates, (Black vs White) patients had increased odds of requiring an MUA after TKA: odds ratio (OR) 1.97, 95% confidence intervals (CI) 1.86-2.10, P.0001. Moreover, White (compared to Black) patients had significantly shorter time to MUA after TKA: 60 days (interquartile range [IQR] 46-88) versus 64 days (interquartile range [IQR] 47-96); P.0001. These disparities persisted from 2013 through 2018.Continued racial differences exist for rates and timing of MUA following TKA signifying the continued need for efforts aimed toward understanding and eliminating inequalities that exist in total joint arthroplasty (TJA) care.

Background and objectives While tranexamic acid (TXA) is an excellent mechanism to reduce blood loss in arthroplasty, its safety in cancer patients-who could potentially benefit the most from blood conservation-is unknown. Methods A multicenter, retrospective review of current or former cancer patients undergoing hip/knee arthroplasty from 2014 to 2019 was performed. The use of intravenous TXA, indication (oncologic/degenerative), cancer state, cancer type, surgical factors, demographics, and comorbidities were collected. The association between TXA use and 90-day/1-year complications was analyzed with multivariable logistic regressions. Results We identified 282 patients with current (87.9%) or former (12.1%) malignancies undergoing arthroplasty (73.0% oncologic/27.0% degenerative). About 74 (26.2%) patients received TXA (52.7% had oncologic indications, 74.3% had active cancer). In adjusted analysis, TXA was not associated with increased risk of venous thromboembolism within 90-days (odds ratio [OR] 0.59; 95% confidence interval [CI] 0.16-2.16, p = 0.43) or 1-year (OR 0.47; 95%CI 0.15-1.44, p = 0.19), with a trend towards lower risk. Similar results were seen for mortality and wound complications, and when stratifying by indication. Conclusion TXA was not associated with increased complications in current or former cancer patients undergoing arthroplasty. Future randomized studies of TXA in arthroplasty should include cancer patients; in the interim, clinicians should weigh the theoretical risks of TXA with the known benefits of reduced blood loss in oncology patients.

The primary purpose of this study was to study and compare rates of two salvage operations for patients with chronically infected total knee arthroplasties: (1) knee arthrodesis and (2) above knee amputation (AKA). An analysis was performed comparing the inpatient hospital characteristics and complications between the two procedures. Secondarily, we presented rates of all surgically treated periprosthetic total knee infections over a 6-year period. Using the Nationwide Inpatient Sample, we identified all patients with a periprosthetic infection (International Classification of Diseases, Ninth Revision [ICD-9] 996.66) from 2009 to 2014. Subsequently, we identified surgically treated total knee infections through the following ICD-9 codes: 00.80 (all component revision), 00.84 (liner exchange), 80.06 (removal of prosthesis), 84.17 (AKA), and 81.22 (knee fusion). From 2009 to 2014, the annual incidence of surgically treated total knee periprosthetic infections increased by 34.9% nationally, while the annual incidence of primary total knees increased by only 13.9%. Salvage operations (AKA and knee fusion) represented 5.8% of all surgically treated infections. The rate of knee fusions decreased from 1.9% of surgically treated infections in 2009 to 1.4% in 2014 (p

Background: The superior approach for total hip arthroplasty (THA) is a minimally invasive, tissue-sparing technique that may have clinical and economic benefits. The purpose of this study was to compare early outcomes between the posterior approach and the superior approach in primary THA. Our hypothesis was that the superior approach would have a noninferior length of stay (LOS), discharge destination, and blood loss compared with the posterior approach. Methods: All primary THAs performed by a single surgeon at one institution were retrospectively reviewed over a 2-year period (2015-2017). There were 676 patients, 40.4% of whom underwent a posterior approach and 59.6% underwent a superior approach. LOS, discharge destination, blood loss, and operating room time were analyzed. Gender, body mass index, and American Society of Anesthesiologists status were recorded and controlled. Results: The posterior approach was independently associated with an almost threefold higher risk of prolonged LOS (>2 days, P < .001) (odds ratio: 2.90, 95% confidence interval: 1.87-4.49; P < .001). The mean LOS for the superior approach was 1.71 days vs 2.17 days for the posterior group (P < .001). Fewer patients in the superior approach cohort were discharged to a rehabilitation facility (8.9% vs 17.9%, P < .001). The mean operative time was shorter in the superior group (91.8 vs 95.8, P = .001). There was no statistically significant difference in acute postoperative blood loss. There were no dislocations or reoperations in either group. Conclusions: The superior approach to THA was associated with a significantly shorter length of hospital stay and lower rate of discharge to rehab than the posterior approach. This approach can be used as a safe, minimally invasive, and tissue-sparing variation of a standard posterior approach for THA and has promising early outcomes.

A large body of research on native hip fractures has resulted in several evidence-based guidelines aimed at improving postsurgical care for these patients. In contrast, there is a paucity of data on pathologic hip fractures, and whether native hip fracture protocols are generalizable to this population is unknown. The purpose of this study was to compare mortality rates and complication profiles between patients with pathologic and native hip fractures.Using the American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) database, we identified patients who underwent surgical treatment for pathologic and native hip fractures from 2007 to 2017 and 2601 matched pairs were identified using propensity scoring. Baseline covariates were controlled for, and rates of 30-day postoperative complications and mortality were compared using McNemar's test.Pathologic hip fracture patients experienced significantly higher rates of death (6.3% vs 4.3%, P .001), serious adverse events (17.3% vs 13.5%, P.001), minor complications (34.3% vs 29.1%, P .001), extended postoperative lengths of stay (30.2% vs 25.9%, P.001), readmissions (11.9% vs 8.4%, P .001), thromboembolic complications (3.0% vs 1.6%, P.001), and perioperative transfusions (31.5% vs 26.4%, P .001) compared to native hip fracture patients.Pathologic hip fractures result in significantly higher complication rates than native hip fractures after surgical treatment, suggesting that guidelines for native hip fractures may not be generalizable for pathologic hip fractures. Orthopedic surgeons should closely monitor these patients for deep vein thrombosis, utilize blood sparing techniques, and employ a multidisciplinary approach to help manage and prevent a more heterogenous profile of postsurgical complications.

Poor preoperative mental health has been associated with worse outcomes after total hip (THA) and total knee arthroplasty (TKA). To fully understand these relationships, we assessed post-THA and post-TKA improvements in patient-reported mental and joint health by preoperative mental health groups.Elective cases (367 THA, 462 TKA) were subgrouped by low (25th percentile), middle (25th-74th), and high (≥75th) preoperative mental health, using Veterans RAND 12-Item Health Survey Mental Component Summary (MCS) scores. In each subgroup, we assessed the relationship between preoperative MCS and 1-year postoperative change in mental and joint health. Pairwise comparisons and multivariable regression models were applied for THA and TKA separately.Median postoperative mental health change was +14.0 points for the low-MCS THA group, +11.1 low-TKA, +2.0 middle-THA and TKA, -4.0 high-THA, and -4.9 high-TKA (between-group differences P .001). All MCS groups had improved median joint health scores, without significant between-group differences. Preoperative mental health was negatively associated with mental health improvements in all groups (B = -0.94 - -0.68, P.001-P = .01) but with improvements in joint health only in the low-THA group (B = -0.74, P = .02). Improvements in mental and joint health were positively associated for low and middle (B = 0.61-0.87, P.001), but not for high-MCS groups, with this relationship differing for the low versus high group.Patients who have low preoperative mental health experienced greater postoperative mental health improvement and similar joint health improvement compared to patients who have high preoperative mental health. Findings can guide subgroup-targeted surgical decision-making and preoperative counseling.

After the suspension of elective surgeries was lifted in June 2020 in New York State, challenges remained regarding coordination of total joint arthroplasty (TJA) cases. Using the experience from a high-volume health system in New York City, we aimed to describe patterns of care after resumption of elective TJA.We retrospectively assessed 7,699 TJAs performed before and during the COVID-19 pandemic. Perioperative characteristics and clinical outcomes were compared between TJAs based on time period of performance: 1) pre-pandemic (PP, June 8th-December 8th, 2019), 2) initial period post-resumption of elective surgeries (IR, June 8th-September 8th, 2020), and 3) later period post-resumption (LR, September 9th-December 8th, 2020).LOS 2 days (83%, 67%, 70% for PP, IR, LR periods respectively) and discharge rates to post-acute care (PAC) facilities were lower during the pandemic periods (ORDespite decreased LOS and discharge to PAC for TJAs performed during the pandemic, 30-day readmissions did not increase. Given the increased costs and lack of superior functional outcomes associated with discharge to PAC, these findings suggest that discharge to PAC facilities need not return to pre-pandemic levels.

Provider-run "joint classes" educate total joint arthroplasty (TJA) patients on how to best prepare for surgery and maximize recovery. There is no research on potential healthcare inequities in the context of joint classes or on the impact of the recent shift toward telehealth due to coronavirus disease 2019 (COVID-19). Using data from a large metropolitan health system, we aimed to (1) identify demographic patterns in prepandemic joint class attendance and (2) understand the impact of telehealth on attendance.We included data on 3,090 TJA patients from three centers, each with a separately operated joint class. Attendance patterns were assessed prepandemic and after the resumption of elective surgeries when classes transitioned to telehealth. Statistical testing included standardized differences (SD0.1 indicates significance) and a multivariate linear regression.The in-person and telehealth attendance rates were 69.9% and 69.2%, respectively. Joint class attendance was significantly higher for non-White, Hispanic, non-English primary language, Medicaid, and Medicare patients (all SD0.1). Age was a determinant of attendance for telehealth (SD0.1) but not for in-person (SD = 0.04). Contrastingly, physical distance from hospital was significant for in-person (SD0.1) but not for telehealth (SD = 0.06). On a multivariate analysis, distance from hospital (P.05) and telehealth (P.0001) were predictors of failed class attendance.This work highlights the relative importance of joint classes in specific subgroups of patients. Although telehealth attendance was lower, telehealth alleviated barriers to access related to physical distance but increased barriers for older patients. These results can guide providers on preoperative education and the implementation of telehealth.

As oncology patients have increasing life expectancies, total hip arthroplasty (THA) may become an important treatment option for pathologic proximal femur fractures (PPFFs). Although THA and hemiarthroplasty (HA) have been compared for native hip fracture treatment, no data on short-term morbidity and mortality are available in the pathologic setting. The purpose of this study is to compare short-term morbidity and mortality of HA vs THA for PPFFs.The National Surgical Quality Improvement Program database was queried from 2007 to 2017 for patients with PPFFs treated with HA or THA. Propensity-adjusted logistic regressions were implemented to compare 30-day morbidity and mortality between procedures. Backwards stepwise regression was then used to determine independent predictors of treatment with HA compared to THA.In adjusted analysis, THA was associated with longer operative times (120.3 ± 5.6 vs 98.7 ± 4.9 minutes, P.001); however, there were no differences between THA and HA with regard to 30-day rates of major complications (P = .3), minor complications (P = .77), reoperations (P = .99), readmissions (P = .35), or deaths (P = .63). Older age (P.001), dependent functional status (P = .02), and the presence of disseminated cancer (P = .049) were predictive of undergoing HA compared to THA.As patients with metastatic cancer continue to live longer with their disease, the durability of surgical reconstruction to treat PPFFs is becoming increasingly important. This study demonstrated no significant differences in 30-day complications between PPFF patients treated with THA or HA after controlling for underlying confounders. These results suggest that THA can be utilized to treat certain patients with PPFFs, and future work is warranted to examine long-term functional outcomes.

FDG-PET scan imaging for sarcoma patients serves several important purposes including (1) the identification of high-grade sarcomas, which may present initially as histologically low or intermediate-grade tumors; (2) the pre-resection assessment and demonstration of tumor response following neoadjuvant systemic therapy, by serial PET imaging, in addition to concurrent, serial MRI; and (3) the assessment of metastasis or local tumor recurrence on subsequent patient restaging during the course of treatment or follow-up.

Despite an increasing prevalence of patients sustaining pathologic fractures of neoplastic origin, few studies have investigated 30-day postoperative complication profiles after surgical treatment of pathologic humerus fractures. The purposes of this study were to use a large nationally representative database to determine short-term complication profiles after surgical treatment of pathologic humerus fractures and assess how these complications compared with more commonly studied native humerus fractures.Using the National Surgical Quality Improvement Program database, we identified 30,866 patients who underwent surgical treatment for either pathologic (n = 449) or native humerus fractures (n = 30,417) from 2007 to 2017. Thirty-day postoperative complication profiles were ascertained and compared between the 2 groups using χPatients with pathologic humerus fractures experienced significantly higher rates of death (6.0% vs. 0.3%, P.001), serious adverse events (12.2% vs. 3.7%, P.001), minor complications (15.8% vs. 4.8%, P.001), extended postoperative lengths of stay (42.3% vs. 21.3%, P.001), discharge to facilities (22.3% vs. 13.5%, P.001), and readmissions (14.8% vs. 3.4%, P.001) compared with patients with native humerus fractures. With respect to specific complications, patients with pathologic fractures were at significantly higher risk of pulmonary complications (1.3% vs. 0.3%, P.001), renal complications (0.7% vs. 0.2%, P = .007), thromboembolic complications (1.6% vs. 0.6%, P = .01), and transfusions (15.1% vs. 4.1%, P.001).After surgical treatment, patients with pathologic humerus fractures had significantly higher complication rates compared with native humerus fractures, suggesting that guidelines and treatment algorithms for native humerus fractures may not be generalizable for those of pathologic origin. These findings have significant implications for preoperative patient counseling and may be used to negotiate higher reimbursement rates for these patients given a significantly higher morbidity and mortality than was previously described in literature. Postoperatively, orthopedic surgeons should closely monitor patients with pathologic humerus fractures for deep vein thrombosis, renal complications, and pulmonary complications, use blood-sparing techniques, and employ a multidisciplinary approach to help manage and prevent a more heterogeneous profile of postsurgical complications.

Background:Individual pelvic tilt and rotation have wide variability that can affect the measurement of cup orientation in anteroposterior (AP) radiographs. The purpose of this study was to analyse the effect of pelvic tilt and rotation on radiographic measurements of cup orientation.Methods:A total of 53 patients (63 hips) were included in this study. The patients underwent a computed tomography study with standing AP pelvis radiographs taken both preoperatively and approximately 3 months postoperatively. We used 2-dimensional/3-dimensional matching to measure the pelvic tilt and rotation, and the non-standardised and standardised cup orientation.Results:There was no difference in the pelvic tilt and rotation between the preoperative and postoperative radiographs. The distribution of the differences between the non-standardised and standardised cup anteversion exhibited a change within 5° in only 34/63 (54%) hips. The pelvic tilt correlated with the difference between the non-standardised and standardised cup anteversion, but the pelvic rotation did not. When all 63 hips were separated into the right and left sides, the pelvic rotation inversely correlated with the pelvic tilt-adjusted difference between the non-standardised and standardised cup anteversion of the right side but directly correlated with that of the left side.Conclusions:The current study demonstrated that the measurement of cup anteversion in standing AP radiographs is significantly affected by both the pelvic tilt and pelvic rotation. An improved understanding of the pelvic orientation may eventually allow for desired cup positioning on a patient-specific basis to potentially reduce complications associated with the malposition of the cup.

Background Hemiarthroplasty (HA) and total hip arthroplasty (THA) have been widely discussed as treatment options for displaced osteoporotic femoral neck fractures. Pathologic femoral neck fractures from primary or metastatic tumors are comparatively rare and poorly investigated. The purpose of this study was to compare outcomes, complications, and perioperative survival for HA and THA in the treatment of pathologic femoral neck fractures of neoplastic etiology. Methods A multicenter retrospective cohort study identified patients with pathologic femoral neck fractures treated with HA or THA from 2005 to 2018. Demographics, American Society of Anesthesiologists classification, Charlson comorbidity index, Dorr classification, histopathologic diagnosis, and surgical data were compared. The primary outcome was reoperation. Secondary outcomes included 90-day mortality, estimated blood loss, length of stay, periprosthetic fracture, periprosthetic joint infection, and Eastern Cooperative Oncology Group performance status. Results There were 116 patients with HA and 48 patients with THA, with no differences between groups with regard to American Society of Anesthesiologists classification, Charlson comorbidity index, or Dorr classification. There were no differences between HA and THA in the primary outcome of reoperation (5.2% vs 4.2%, P = 1.00) or secondary outcomes of perioperative 90-day overall mortality (30.2% vs 25.0%, P = .51), estimated blood loss, transfusion rates, length of stay, discharge location, periprosthetic joint infection, periprosthetic fracture, or preoperative or postoperative Eastern Cooperative Oncology Group performance status. Conclusions Both HA and THA are viable options for the treatment of patients with pathologic femoral neck fractures and demonstrated no differences in reoperations, complications, perioperative 90-day mortality, or functional outcome scores. Level of Evidence Level III.

The purpose of this study is to analyze the effect of pelvic tilt and rotation on radiographic measurement of cup orientation.A total of 68 patients (79 hips) were included in this study. The patients had a computed tomography study and approximately 3 months of postoperative standing anteroposterior pelvic radiographs in both supine and standing positions. We used 2-dimensional (2D)/3-dimensional (3D) matching to measure pelvic tilt and rotation, and cup orientation.There was a wide range of pelvic tilt between individuals in both supine and standing positions. Supine pelvic tilt was different from standing pelvic tilt (P.05). There were differences in cup anteversion before and after 2D/3D matching in both supine and standing positions (P.05). Supine and standing pelvic tilt correlated with differences in cup anteversion before and after 2D/3D matching. When all 79 hips were separated into right and left side, pelvic rotation inversely correlated with the pelvic tilt-adjusted difference in anteversion before and after 2D/3D matching of the right side but directly correlated with that of the left side in both supine and standing positions.This study demonstrated that the measurement of cup anteversion on anteroposterior radiographs is significantly affected by both pelvic tilt and pelvic rotation (depending on the side). Improved understanding of pelvic orientation and improved ability to measure pelvic orientation may eventually allow for desired cup positioning to potentially protect against complications associated with malposition of the cup.

The anterior approach is increasingly practiced throughout the United States. Advocates claim it is minimally invasive, tissue friendly with decreased dislocation rates, decreased hospital stay, and improved outcomes. Recent data however, indicates high complication rates; wound problems, fractures, femoral loosening, and dislocation rates similar to other approaches. The superior approach is modeled after an ideal approach to total hip arthroplasty that is tissue-preserving, inexpensive, and reduces complications of other techniques. Features of the superior approach include simple positioning, no dislocation of the femoral head, preservation of abductors, anterior and posterior capsule, and most, if not all of the external rotators.

Cup malposition is a common cause of impingement, limitation of ROM, acceleration of bearing wear, liner fracture, and instability in THA. Previous studies of the safe zone based on plain radiographs have limitations inherent to measuring angles from two-dimensional projections. The current study uses CT to measure component position in stable and unstable hips to assess the presence of a safe zone for cup position in THA.(1) Does acetabular component orientation, when measured on CT, differ in stable components and those revised for recurrent instability? (2) Do CT data support historic safe zone definitions for component orientation in THA?We identified 34 hips that had undergone revision of the acetabulum for recurrent instability that also had a CT scan of the pelvis between August 2003 and February 2017. We also identified 175 patients with stable hip replacements who also had a CT study for preoperative planning and intraoperative navigation of the contralateral side. For each CT study, one observer analyzed major factors including acetabular orientation, femoral anteversion, combined anteversion (the sum of femoral and anatomic anteversion), pelvic tilt, total offset difference, head diameter, age, sex, and body mass index. These measures were then compared among stable hips, hips with cup revision for anterior instability, and hips with cup revision for posterior instability. We used a clinically relevant measurement of operative anteversion and inclination as opposed to the historic use of radiographic anteversion and inclination. The percentage of unstable hips in the historic Lewinnek safe zone was calculated, and a new safe zone was proposed based on an area with no unstable hips.Anteriorly unstable hips compared with stable hips had higher operative anteversion of the cup (44° ± 12° versus 31° ± 11°, respectively; mean difference, 13°; 95% confidence interval [CI], 5°-21°; p = 0.003), tilt-adjusted operative anteversion of the cup (40° ± 6° versus 26° ± 10°, respectively; mean difference, 14°; 95% CI, 10°-18°; p0.001), and combined tilt-adjusted anteversion of the cup (64° ± 10° versus 54° ± 19°, respectively; mean difference, 10°; 95% CI, 1°-19°; p = 0.028). Posteriorly unstable hips compared with stable hips had lower operative anteversion of the cup (19° ± 15° versus 31° ± 11°, respectively; mean difference, -12°; 95% CI, -5° to -18°; p = 0.001), tilt-adjusted operative anteversion of the cup (19° ± 13° versus 26° ± 10°, respectively; mean difference, -8°; 95% CI, -14° to -2°; p = 0.014), pelvic tilt (0° ± 6° versus 4° ± 6°, respectively; mean difference, -4°; 95% CI, -7° to -1°; p = 0.007), and anatomic cup anteversion (25° ± 18° versus 34° ± 12°, respectively; mean difference, -9°; 95% CI, -1° to -17°; p = 0.033). Thirty-two percent of the unstable hips were located in the Lewinnek safe zone (11 of 34; 10 posterior dislocations, one anterior dislocation). In addition, a safe zone with no unstable hips was identified within 43° ± 12° of operative inclination and 31° ± 8° of tilt-adjusted operative anteversion.The current study supports the notion of a safe zone for acetabular component orientation based on CT. However, the results demonstrate that the historic Lewinnek safe zone is not a reliable predictor of future stability. Analysis of tilt-adjusted operative anteversion and operative inclination demonstrates a new safe zone where no hips were revised for recurrent instability that is narrower for tilt-adjusted operative anteversion than for operative inclination. Tilt-adjusted operative anteversion is significantly different between stable and unstable hips, and surgeons should therefore prioritize assessment of preoperative pelvic tilt and accurate placement in operative anteversion. With improvements in patient-specific cup orientation goals and acetabular component placement, further refinement of a safe zone with CT data may reduce the incidence of cup malposition and its associated complications.Level III, diagnostic study.

To report the safety and clinical outcomes of placing current magnetic resonance imaging (MRI) components inside and outside the MRI bore during MRIs.Retrospective case series.Four trauma centers (3 Level I and 1 Level II), from January 2005 to January 2015.All patients who had MRIs with external fixators in place either inside or outside the MRI bore.MRI of patients with external fixator in place.Adverse events were defined as catastrophic pullout of the external fixator during the MRI, thermal injury to the skin, severe field distortions precluding the intended imaging, alterations of the magnetic field, or visible structural damage to the magnet casing.Thirty-eight patients with 44 external fixators were identified who had MRI with the fixator inside or outside the MRI bore. Twelve patients with 13 external fixators had MRI with the external fixator inside the MRI bore. Twenty-seven patients with 32 external fixators had MRI with the external fixator outside the MRI bore. There were no adverse events.Although no universal guidelines exist, there are circumstances in which obtaining MRIs of patients with external fixators can be safe. This is the first clinical series with the primary outcome of safety when placing modern external components both inside and outside an MRI bore during a scan.Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Periprosthetic joint infections are a major cause of morbidity and mortality following total joint arthroplasty. Two-stage arthroplasty, with the use of an antibiotic cement spacer, is an effective means of managing periperiprosthetic joint infections. There is a lack of data relating to the management, prognosis, and clinical outcomes associated with multiple peri-prosthetic joint infections. Here, we present a case report of a patient successfully treated for three synchronic peri-prosthetic joint infections of both knees and a single hip.

The scapula is a relatively uncommon site for primary bone sarcomas. Tumors arising from the scapula are often initially contained by the rotator cuff muscles that protect pertinent adjacent muscles as well as the brachial plexus and axillary blood vessels. Limb-sparing resection of a scapula sarcoma is technically complex and requires meticulous dissection and mobilization of the brachial plexus and axillary blood vessels. Several muscles must be capable of being preserved in order to reconstruct the scapula and shoulder girdle with a special customized total scapula replacement. The goal of reconstruction is to restore a stable shoulder girdle to preserve elbow and hand function.In the procedure demonstrated in this video, limb-sparing scapula resection and reconstruction was performed for a patient with a multicentric epithelioid hemangioendothelioma. The steps of the procedure are detailed along with accommodations made for the multicentric nature of the tumor. To allow for optimal postoperative function and maximum soft tissue coverage, a small constrained scapular prosthesis was utilized. The glenohumeral ligaments were reconstructed with a Gore-Tex aortic graft. Multiple muscle rotation flaps were performed to cover and protect the prosthesis as well as restore shoulder girdle stability.Limb-sparing surgery for scapula sarcomas and anatomic reconstruction with a constrained total scapula prosthesis is a reliable and safe technique for resecting selected sarcomas and reconstructing the shoulder girdle. A stable shoulder girdle can be restored for optimal hand and elbow function. A total scapula prosthetic reconstruction is the authors' procedure of choice when the deltoid, trapezius, rhomboid, latissimus, and serratus anterior muscles are capable of being preserved. The functional outcome is superior to a forequarter amputation and a flail (nonreconstructed) shoulder in which the extremity is left hanging by soft tissues (nonanatomic method).

A limb-sparing resection was performed for osteosarcoma of the proximal tibia in a young patient. A special modular segmental proximal tibial endoprosthesis that includes a hinged total knee component was used for reconstruction. A medial gastrocnemius rotational flap was utilized to reconstruct the extensor mechanism of the knee. The muscle flap aids in covering the prosthesis and helps to protect against infection. Limb-sparing resection for tumors arising from the proximal tibia, and reconstruction with a modular segmental proximal tibia tumor prosthesis and gastrocnemius muscle flap, is a safe and reliable method for treating tumors involving this area.