Total hip arthroplasty with monobloc press-fit acetabular components and large-diameter bearings for atypical acetabula is safe: a consecutive case series of 125 hips with mean follow-up of 9 years.

BACKGROUND: Large-diameter head (LDH) total hip arthroplasty (THA) with a monobloc acetabular component improves hip stability. However, obtaining initial press-fit stability is quite challenging in atypical acetabula. The purpose of this study was to assess primary and secondary fixation of monobloc cups in atypical acetabula. METHODS: In this consecutive case series, the local arthroplasty database was used to retrospectively identify patients with secondary osteoarthritis who underwent primary hip replacement with press-fit only LDH monobloc acetabular components between 2005 and 2018 and who had a minimum of 2 years of follow-up. Radiographic evaluation was performed at last follow-up, and patient-reported outcome measures (PROMs) were assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Forgotten Joint Score (FJS), and the Patient's Joint Perception (PJP) question. RESULTS: One hundred and six LDH THAs and 19 hip resurfacings were included in the study. Preoperative diagnoses included hip dysplasia (36.8%), Legg-Calve-Perthes disease (32.0%), osteoarthritis with acetabular deficiency (17.6%), periacetabular osteotomy (8.0%), arthrodesis (4.0%), and osteopetrosis (1.6%). After a mean follow-up of 9.2 years, no aseptic loosening of the acetabular component was recorded nor observed on radiologic review. There were 13 (10.4%) revisions unrelated to the acetabular component fixation. The mean WOMAC and FJS scores were 9.2 and 80.9, respectively. In response to the PJP question, 49.4% of the patients perceived their hip as natural, 19.1% as an artificial joint with no restriction, 31.5% as an artificial joint with restriction, and none as a non-functional joint. CONCLUSION: Primary press-fit fixation of monobloc acetabular components with LDH implanted in atypical acetabula led to secondary fixation in all cases with low revision and complication rates and great functional outcomes. With careful surgical technique and experience, systematic use of supplemental screw fixation is not essential in THA with atypical acetabula.

Primary total knee arthroplasty in hemophilic arthropathy.

Advanced hemophilic knee arthropathy is a frequent and devastating manifestation of severe hemophilia with significant implications for activities of daily living. Hemophilic arthropathy is caused by repeated bleeding, resulting in joint degeneration, pain, deformity and disability. In patients with hemophilia and advanced disease, total knee arthroplasty (TKA) has proven to be the most successful intervention, improves physical function and reduces knee pain. Hemophilic patients carry additional risks for complications and required specific pre/postoperative considerations. Expert treatment center should be used to improve patient outcome. Hemophilic patients present significant surgical challenges such as joint destruction, bone loss, severe ankylosis and oligoarticular involvement. The surgeon performing the arthroplasty must be experienced to manage such problems.

Monobloc press-fit cups with large-diameter bearings are safe in revision total hip arthroplasty.

BACKGROUND: Instability is a major cause of failure of revision total hip arthroplasty (THA) which can be avoided with the use of monobloc press-fit cups with large diameter heads (LDH). OBJECTIVE: This consecutive case series analyses whether LDH monobloc components are a safe and clinically beneficial option for revision THA. METHODS: This consecutive case series includes 47 revision THA with LDH monobloc acetabular cup. Acetabular bone defects were Paprosky type I (42), type IIA (2) and type IIC (3). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Forgotten Joint Score (FJS) and the Patient's Joint Perception (PJP) scores were analysed and a radiographic evaluation for signs of implant dysfunction was performed. RESULTS: After a mean follow-up of 4.5 years, there were 5 (10.6%) acetabular cup re-revisions: 2 loss of primary fixation and 3 instabilities. Implant survivorship at 4-years was 89.4% (95% CI: 89.3 to 89.5). Recurrent hip dislocation was reported in 1 patient (2.1%) and remains under conservative treatment. The mean WOMAC and FJS were 19.5 (16.8; 0.0 to 58.3) and 57.3 (28.9; 6.3 to 100.0), respectively. Regarding the PJP, 3 (8.8%) patients perceived their hip as natural, 8 (23.5%) as an artificial joint with no restriction, 14 (41.2%) with minor restriction and 9 (26.5%) with major restriction. CONCLUSION: In cases of revision THA with limited bone loss, press-fit primary fixation with LDH monobloc acetabular components are valuable options that offer excellent mid-term out-comes with low re-revision and joint instability rates.

Delayed discharge after total hip arthroplasty is associated with an increased risk of complications.

BACKGROUND: The purpose of this study was to evaluate the influence of discharge timing on 30-day complication rates following total hip arthroplasty. METHODS: We identified patients who underwent total hip arthroplasty between 2011 and 2017 from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Using propensity score matching, we matched patients who were discharged from the hospital on the day of surgery to those discharged on postoperative days 1, 2, 3 and 4, respectively. We used multivariable logistic regression to determine if the rates of complications and readmission differed depending on length of stay. RESULTS: We identified 141 594 patients who underwent total hip arthroplasty (average age 64.7 [standard deviation (SD) 11.4] yr) from the NSQIP database. The average length of stay was 2.3 days and decreased from 2.8 (SD 0.7) days in 2011 to 1.9 (0.9) days in 2017. The adjusted odds of a major complication increased by 1.33 (1.09-1.61) and 1.41 (1.05-2.21) for patients discharged on postoperative day 3 and 4, respectively, compared with patients discharged on postoperative day 2. Similarly, the adjusted odds of a minor complication increased by 1.22 (1.03-1.43) and 1.58 (1.11-2.26) for patients discharged on postoperative days 3 and 4, respectively, compared with those discharged on postoperative day 2. We found no difference in the risk of major or minor complications between patients discharged on the day of surgery or postoperative day 1 compared with patients discharged on postoperative day 2. We also found that a length of stay of 3 or 4 days increased the risk of readmission (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.03-1.29, and OR 1.18, 95% CI 1.08-1.85, respectively) compared with a length of stay of 2 days. CONCLUSION: Our data suggest that discharge on postoperative days 0-2 is associated with the lowest risk of 30-day complications following total hip arthroplasty. These findings support early discharge after total hip arthroplasty; however, more prospective clinical data are required to determine the optimal length of stay following total hip arthroplasty.

Prolonged surgical time increases the odds of complications following total knee arthroplasty.

Background: The aim of this study was to evaluate the influence of operating time on complications and readmission within 30 days of total knee arthroplasty (TKA) and to determine if there were specific time intervals associated with worse outcomes. Methods: The American College of Surgeons' National Surgical Quality Improvement Program database was used to identify patients 18 years of age and older who underwent TKA between 2006 and 2017, using procedural codes. Patient demographic characteristics, operation length and 30-day major and minor complication and readmission rates were captured. We used multivariable regression to determine if the rates of complications and readmission differed depending on the length of the operation, while adjusting for relevant covariables. Results: A total of 263 174 patients who underwent TKA were identified from the database. Their mean age was 66.8 (standard deviation 9.7) years. Within 30 days of the index procedure, 5700 patients (2.2%) experienced a major complication, 5185 (2.0%) experienced a minor complication and 7730 (3.1% of 249 746 patients from 2011 to 2017) were readmitted. Mean operation length was 91.7 minutes (range 30­240 min). After adjustment for relevant covariables, an operating time of 90 minutes or more was a significant predictor of major and minor complications as well as readmission. There was no difference in the odds of complications or readmission for operations lasting 30­49, 50­69 or 70­89 minutes (p > 0.05). Conclusion: Our data suggest that operating times of 90 minutes or more may be associated with an increase in the 30-day odds of complications and readmission following TKA. Further studies are needed to confirm our findings and determine the influence of surgical time on outcomes when there is increased case complexity.

Contexte: Cette étude avait pour but d'évaluer l'influence de la durée opératoire sur les taux de complications et de réadmission dans les 30 jours suivant une arthroplastie totale du genou (ATG) et de déterminer si certaines durées étaient associées à des issues défavorables. Méthodes: Nous avons interrogé la base de données du National Surgical Quality Improvement Program de l'American College of Surgeons pour repérer, à l'aide de codes d'acte, les patients de 18 ans et plus ayant subi une ATG entre 2006 et 2017. Les caractéristiques démographiques des patients, la durée opératoire et les taux de complications mineures et majeures et de réadmission dans les 30 jours suivant l'intervention ont été relevés. Nous nous sommes servis d'une régression logistique multivariée pour déterminer si les taux de complications et de réadmission variaient selon la durée opératoire, tout en tenant compte des covariables pertinentes. Résultats: Au total, 263 174 patients ayant subi une ATG ont été repérés dans la base de données. L'âge moyen était de 66,8 ans (écart type : 9,7 ans). Dans les 30 jours suivant l'intervention de référence, 5700 patients (2,2 %) ont présenté une complication majeure et 5185 (2,0 %), une complication mineure; 7730 patients (3,1 % des 249 746 patients ayant subi une ATG entre 2011 et 2017) ont été réhospitalisés. La durée opératoire moyenne était de 91,7 minutes (plage 30­240 minutes). Après la prise en compte des covariables pertinentes, une durée opératoire de 90 minutes ou plus était un facteur prédictif significatif de complications mineures ou majeures et de réadmission. Aucune différence n'a été constatée quant à la probabilité de complications ou de réadmission pour les chirurgies durant de 30­49 minutes, de 50­69 minutes et de 70­89 minutes (p > 0,05). Conclusion: Ces données laissent croire qu'une durée opératoire de 90 minutes ou plus peut être associée à une hausse des taux de complications et de réadmission dans les 30 jours suivant une ATG. D'autres études sont nécessaires pour confirmer ces résultats et déterminer l'influence de la durée opératoire sur les issues des patients au cas complexe.

The economic impact of periprosthetic infection in total knee arthroplasty.

Background: Currently, the gold standard treatment for periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is 2-stage revision, but few studies have looked at the economic impact of PJI on the health care system. The objective of this study was to obtain an accurate estimate of the institutional cost associated with the management of PJI in TKA and to assess the economic impact of PJI after TKA compared to uncomplicated primary TKA. Methods: We identified consecutive patients in our institutional database who had undergone 2-stage revision TKA for PJI between 2010 and 2014 and matched them on age and body mass index with patients who had undergone uncomplicated primary TKA over the same period. We calculated all costs associated with the 2 procedures and compared mean costs, length of stay, clinical visits and readmission rates between the 2 groups. Results: There were 73 patients (mean age 68.8 [range 48-91] yr) in the revision TKA cohort and 73 patients (mean age 65.9 [range 50-86] yr) in the primary TKA cohort. Two-stage revision surgery was associated with a significantly longer hospital stay (mean 22.7 d v. 3.84 d, p < 0.001), more outpatient clinic visits (mean 8 v. 3, p < 0.001), more readmissions (29 v. 0, p < 0.001) and higher overall cost (mean $35 429.97 v. $6809.94, p < 0.001) than primary TKA. Conclusion: Treatment for PJI after TKA has an enormous economic impact on the health care system. Our data suggest a fivefold increase in expenditure in the management of this complication compared to uncomplicated primary TKA.

Contexte: À l'heure actuelle, le traitement par excellence d'une infection de prothèse articulaire (IPA) survenant après une arthroplastie totale du genou (ATG) est l'arthroplastie de révision en 2 étapes. Toutefois, peu d'études se sont penchées sur les répercussions économiques de l'IPA sur le système de santé. La présente étude visait donc à estimer de façon précise le coût de prise en charge de l'IPA par les établissements, ainsi qu'à évaluer les répercussions économiques de l'IPA après une ATG, comparativement à celles d'une ATG primaire sans complications. Méthodes: Nous avons recensé, dans la base de données de notre établissement, tous les patients consécutifs ayant subi une ATG de révision en 2 étapes pour une IPA entre 2010 et 2014, puis les avons jumelés en fonction de l'âge et de l'indice de masse corporelle avec des patients ayant subi une ATG primaire sans complications durant la même période. Nous avons calculé tous les coûts associés aux 2 interventions, et avons comparé la moyenne des coûts, de la durée d'hospitalisation, des visites cliniques et des réadmissions entre les 2 groupes. Résultats: On comptait 73 patients (âge moyen 68,8 ans [plage 48­91 ans]) dans la cohorte d'ATG de révision, et 73 patients (âge moyen 65,9 ans [plage 50­86 ans]) dans la cohorte d'ATG primaire. L'ATG de révision en 2 étapes, comparativement à l'ATG primaire, a été associée à une durée d'hospitalisation significativement plus longue (moyenne 22,7 j c. 3,84 j; p < 0,001), à un plus grand nombre de visites en clinique externe (moyenne 8 visites c. 3 visites; p < 0,001), à un taux plus élevé de réadmission (29 réadmissions c. 0 réadmission; p < 0,001) et à des coûts globaux plus élevés (moyenne 35 429,97 $ c. 6809,94 $; p < 0,001). Conclusion: Le traitement de l'IPA après une ATG a d'énormes répercussions économiques sur le système de santé. Selon nos données, les dépenses liées à la prise en charge de cette complication pourraient être 5 fois plus élevées que celles liées à une ATG primaire sans complications.

Outcomes of Stemmed versus Un-Stemmed Varus-Valgus Constrained Components in Primary Total Knee Arthroplasty.

PURPOSE: The necessity of stemmed components when performing a varus-valgus constrained (VVC) primary total knee arthroplasty (TKA) is unclear. The purpose of this study is to compare the outcomes of primary VVC TKA with and without stems at a minimum of two years. METHODS: Patients in our prospectively collected database with primary VVC TKAs were identified. Patient demographics, prosthesis data, time in vivo, characteristics of revision, and radiographs and PROMs were compared between the stemmed and un-stemmed cohorts. RESULTS: Sixty-five patients with 69 primary VVC TKAs were identified; 17 were implanted with stems and 52 without stems. Five of the stemmed TKAs (5/17) required revision at 15.1 years, while only one of the un-stemmed TKA (1/52) required a revision at 21.6 years (p=0.003) for aseptic loosening. Of the 5 stemmed TKAs requiring revision, 3 were for aseptic loosening and 2 were for PPJI. The un-stemmed cohort had a significantly higher final total KSS (p=0.048). CONCLUSION: There was no increase in aseptic loosening or revision surgery in patients with non-stemmed primary VVC TKA compared to those with stemmed VVC TKA at mid-term follow-up. Utilizing non-stemmed TKA with VVC in appropriate cases is safe and may reduce cost, shorten operative time, and preserve bone-stock.

Direct anterior approach for femoral component revision: Surgical technique for extended trochanteric osteotomy and anterior cortical window.

OBJECTIVE: Direct anterior approach (DAA) is becoming a popular option for both primary and revision total hip arthroplasty (THA). Adequate exposure is crucial in the setting of revision THA. The purpose of this article is to describe two different techniques for expanded femoral exposure through the DAA, the anterior extended trochanteric osteotomy and anterior cortical window. METHODS: Extensile exposure were carried out in cadavers, using the contralateral hip as a control. The exposure and technical viability were assessed. RESULTS: It was demonstrated that both extensile techniques can be carried out safely. CONCLUSIONS: Extensile exposures including femoral osteotomies can be safely carried out for revision THA via DAA.

Correlation between hip osteoarthritis and the level of physical activity as measured by wearable technology and patient-reported questionnaires.

This study evaluates physical activity in patients with advanced hip OA using Fitbit and whether a correlation exists between the number of steps taken per day (SPD) and the reported outcome. METHODS: 122 patients were prospective enrolled. Patient-reported outcomes were collected. Patients were asked to wear a Fitbit for 24 h a day on seven consecutive days. RESULT: The mean number of SPD was 5721 ± 3920. The UCLA, HHS and SF-12 PCS demonstrated a statistically significant positive correlation with the SPD. CONCLUSION: Wearable technology is reliable in objectively measuring the level of physical activity in hip OA and correlates with reported outcomes.

The economic impact of periprosthetic infection in total hip arthroplasty

Background: Periprosthetic joint infection (PJI) is the third leading cause of total hip arthroplasty (THA) failure. Although controversial, 2-stage revision remains the gold standard treatment for PJI in most situations. To date, there have been few studies describing the economic impact of PJI in today's health care environment. The purpose of the current study was to obtain an accurate estimate of the institutional cost associated with the management of PJI in THA and to assess the economic burden of PJI compared with primary uncomplicated THA. Methods: We conducted a review of primary THA cases and 2-stage revision THA for PJI at our institution. Patients were matched for age and body mass index. All costs associated with each procedure were recorded. Descriptive statistics were used to summarize the collected data. Mean costs, length of stay, clinic visits and readmission rates associated with the 2 cohorts were compared. Results: Fifty consecutive cases of revision THA were matched with 50 cases of uncomplicated primary THA between 2006 and 2014. Compared with the primary THA cohort, PJI was associated with a significant increase in mean length of hospital stay (26.5 v. 2.0 d, p < 0.001), mean number of clinic visits (9.2 v. 3.8, p < 0.001), number of readmissions (12 v. 1, p < 0.001) and average overall cost (Can$38 107 v. Can$6764, t = 8.3, p < 0.001). Conclusion: Treatment of PJI is a tremendous economic burden. Our data suggest a 5-fold increase in hospital expenditure in the management of PJI compared with primary uncomplicated THA.

Contexte: L'infection articulaire périprothétique (IAP) arrive au troisième rang des principales causes d'échec de l'arthroplastie (ou prothèse) totale de la hanche (PTH). Même si elle est controversée, la révision en 2 étapes demeure le traitement standard pour l'IAP dans la plupart des cas. À ce jour, peu d'études ont décrit l'impact économique de l'IAP dans l'environnement actuel des soins de santé. Le but de la présente étude était d'obtenir une estimation précise des coûts institutionnels associés à la prise en charge de l'IAP dans la PTH et d'évaluer le fardeau économique de l'IAP comparativement à une PTH primaire non compliquée. Méthodes: Nous avons passé en revue les cas de PTH primaire et de révision de PTH en 2 étapes pour cause d'IAP dans notre établissement. Les patients ont été assortis selon l'âge et l'indice de masse corporelle. Tous les coûts associés à chaque intervention ont été consignés. Des statistiques descriptives ont servi à résumer les données recueillies. Nous avons comparé les coûts moyens, la durée des séjours, les visites à la clinique et les taux de réadmission associés aux 2 cohortes. Résultats: Cinquante cas consécutifs de révision de PTH ont été assortis à 50 cas de PTH primaire non compliquée entre 2006 et 2014. Comparativement à la cohorte de PTH primaire, les cas d'IAP ont été associés à une augmentation significative de la durée moyenne du séjour hospitalier (26,5 j c. 2,0 j, p < 0,001), du nombre moyen de visites à la clinique (9,2 c. 3,8, p < 0,001), du nombre des réadmissions (12 c. 1, p < 0,001) et du coût global moyen (38 107 $ CA c. 6764 $ CA, t = 8,3, p < 0,001). Conclusion: Le traitement de l'IAP représente un énorme fardeau économique. Selon nos données, les dépenses hospitalières associées à sa prise en charge sont 5 fois plus grandes que pour la PTH primaire non compliquée.

Reproducing the Native Posterior Tibial Slope in Cruciate-Retaining Total Knee Arthroplasty: Technique and Clinical Implications.

Total knee arthroplasty (TKA) profoundly influences knee biomechanics. Using an arbitrary (often 3° to 5°) posterior tibial slope (PTS) in all cases seldom will restore native slope. This study examined whether the native PTS could be reproduced in cruciate-retaining TKA and how this would influence clinical outcome. Radiographic and clinical outcomes of 215 consecutive TKAs using the PFC sigma cruciate-retaining implant were evaluated. The tibial bone cut was planned to be made parallel to the native anatomical slope in the sagittal plane. The PTS was measured with reference to the proximal tibial medullary canal (PTS-M) and the proximal tibial anterior cortex (PTS-C) on true lateral radiographs using a picture achieving and communication system. Knee range of motion (ROM), Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form Health Survey (SF-12) were evaluated. Mean preoperative PTS-M was 6.9°±3.3°, and mean postoperative PTS-M was 7.0°±2.4°. Mean preoperative PTS-C was 12.2°±4.2°, and mean postoperative PTS-C was 12.6°±3.4°. Preoperative and postoperative PTS were not significantly different for both techniques (P>.05). An arbitrary 3° as an acceptable range for PTS-M was achieved in 144 knees (67%) (group 1), and 71 knees (33%) had a difference of more than 3° (group 2). Group 1 had a significantly larger gain in ROM (P=.04) as well as improved Knee Society, WOMAC, and SF-12 physical scores compared with group 2 (P<.01). The modified surgical technique reproduced the native tibial slope in cruciate-retaining TKA. Reproduction of the native PTS within 3° resulted in better clinical outcomes manifested by gain in ROM and knee functional outcome scores. [Orthopedics. 2020; 43(1):e21-e26.].

Treatment of Femur Neck Fracture in Children with Osteogenesis Imperfecta: Two Case Reports.

CASE: We present 2 cases of femoral neck fracture (FNF) in patients with osteogenesis imperfecta (OI) with a previously placed intramedullary nail (IMN). Case 1: A 12-year-old girl who sustained a right FNF after spine surgery. Case 2: An 18-year-old boy who sustained a right FNF after IMN of the left side. Both patients underwent our modified surgical technique as described below. Both patients recovered well overall. CONCLUSIONS: FNF in patients with OI poses a significant challenge especially in the presence of an IMN. Here, we describe a surgical technique that provides stable fixation with a less stress riser effect by bypassing the screws and a previously placed nail.

Assessing Preoperative Mobility in Total Hip Arthroplasty: A SAFE T database study.

This study examined whether individuals undergoing total hip arthroplasty who are self-rated as "highly active", demonstrated higher pre-operative activity levels than others. METHODS: 483 patients were retrospectively identified; 241 were "highly active" and 242 were not. They were compared using WOMAC, self-reported activity and 6-Minute Walk Test (6MWT). RESULTS: Self-reported highly active adults demonstrated statistically significant higher WOMAC scores (48.85 vs 43.79), increased mean number of activities performed and mean 6MWT (348.14 m vs 274.64 m). CONCLUSIONS: The positive correlation between subjective and objective measures of mobility increase our confidence in the latter as valid indicator of patient's preoperative activity level.

Predictive Factors for Discharge Destination Following Posterior Lumbar Spinal Fusion: A Canadian Spine Outcome and Research Network (CSORN) Study.

STUDY DESIGN: Ambispective cohort study. OBJECTIVE: Patients spend on average 3 to 7 days in hospital after lumbar fusion surgery. Patients who are unable to be discharged home may require a prolonged hospital stay while awaiting a bed at a rehabilitation facility, adding cost and imposing a considerable burden on the health care system. Our objective is to identify patient or procedure related predictors of discharge destination for patients undergoing posterior lumbar fusion. METHODS: Analysis of data from the Canadian Spine Outcomes and Research Network. Patients who underwent lumbar fusion for degenerative pathology between 2008 and 2015 were identified. Multivariable logistic regression analysis was used to identify independent predictors of the discharge destination. RESULTS: A total of 643 patients were identified from the database, 87.1% of the patients (N = 560) were discharged home while 12.9% (N = 83) required discharge to nonhome facilities. Using multivariate logistic regression analysis, the predictors for discharge to a facility rather than home were identified including: increasing age (odds ratio [OR] 1.045, 95% confidence interval [CI] 1.017 -1.075, P < .002), increasing body mass index (BMI) (OR 1.069, 95% CI 1.021 -1.118, P < .004), increasing disability score (OR 1.025, 95% CI 1.004 -1.046, P < .02), living alone preoperatively (OR 1.916, 95% CI 1.004-3.654, P < .05), increasing operating time (OR 1.005, 95% CI 1.003 -1.008, P < .0001), need for blood transfusion (OR 3.32, 95% CI 1.687-6.528, P < .001), and multilevel fusion surgery (OR 1.142, 95% CI 1.007 -1.297, P < .04). CONCLUSIONS: Older age, high BMI, living alone, high disability score, extended surgical time, blood transfusion, and multilevel fusion are significant factors that increase the odds of being discharged to facilities other than home. LEVEL OF EVIDENCE: Level 3.

Effect of Medial Soft Tissue Releases During Posterior-Stabilized Total Knee Arthroplasty on Contact Kinematics and Patient-Reported Outcomes.

BACKGROUND: Minimal to extensive medial soft tissue releases are part of the exposure and achieving adequate varus knee balance in total knee arthroplasty (TKA). However, the effect of these releases on knee kinematics and patient-reported outcomes is unclear. Our objective was to compare the postoperative in vivo tibiofemoral contact kinematics of a posterior-stabilized TKA between patients who received minimal medial soft tissue releases intraoperatively to those who received extensive releases. We also compared these groups using patient-reported outcomes. METHODS: A prospective imaging study was performed in a single-center over a 14-month period. Patients with end-stage osteoarthritis and varus deformity undergoing primary TKA were included. Baseline data were collected 1 month before surgery. The radiostereometric analysis imaging took place at least 1 year postoperatively and composed of weight-bearing radiographic stereo examinations of knee flexion starting in full extension and in 20° increments of flexion to a maximum of 120°. Intraoperative medial soft tissue releases were recorded. Patient-reported outcomes used included Short-Form 12, Western Ontario and McMaster Osteoarthritis Index, and Knee Society Score. RESULTS: Fifty-one patients were included in the statistical analysis. Demographic characteristics were similar between all. Patients were divided into 3 groups depending on the amount of releases they received. No statistically significant differences in tibiofemoral contact positions or excursions on the medial or lateral condyles were found throughout flexion from 0° to 120°. Postoperative patient-reported outcome scores were not different. CONCLUSION: Correcting severe varus deformities with extensive medial soft tissue release largely did not alter knee kinematics or clinical outcome scores compared to those with minimal soft tissue release.

No Difference in Major Complication and Readmission Rates Following Simultaneous Bilateral vs Unilateral Total Hip Arthroplasty.

BACKGROUND: Simultaneous bilateral total hip arthroplasty (THA) is an attractive option for patients with osteoarthritis as it requires a single anesthetic and hospitalization. Nonetheless, serious concerns remain over the perioperative safety and rate of hospital readmission. The purpose of the present study was to compare the rate of 30-day major complications and hospital readmissions between patients undergoing simultaneous bilateral vs unilateral THA using the National Surgical Quality Improvement Program database. METHODS: The National Surgical Quality Improvement Program database was queried from 2011 to 2015 inclusively to identify all cases of elective, primary simultaneous bilateral THA and match them to a control group of unilateral THA cases. A multivariable regression analysis was then used to assess the relationship of simultaneous bilateral vs unilateral THA on major complications and readmissions. RESULTS: A total of 575 bilateral THA patients were matched to 2290 unilateral THA patients using a 4:1 ratio based on age, sex, and American Society of Anesthesiologists scores. Bilateral THA patients were more likely to undergo general anesthesia (77% vs 58.7%, P < .0001), required more postoperative transfusions (29.2% vs 15.9%, P < .0001) and were more often discharged to a rehabilitation facility rather than home (39.4% vs 20.8%, P < .0001). However, the adjusted odds of a major complication (odds ratio = 0.72, 95% confidence interval [0.41-1.24], P = .24) and 30-day readmission (odds ratio = 0.67, 95% confidence interval [0.38-1.19], P = .17) were similar between the 2 groups. CONCLUSION: Although patients who underwent simultaneous bilateral THA were more likely to be discharged to a rehabilitation facility and required significantly more perioperative transfusions compared to those undergoing unilateral THA, the odds of a 30-day major complication and readmission were similar between groups. LEVEL OF EVIDENCE: III.

Predictors of Blood Transfusion in Posterior Lumbar Spinal Fusion: A Canadian Spine Outcome and Research Network Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To identify patient or procedure related predictors of postoperative blood transfusions in posterior lumbar fusion (PSF). SUMMARY OF BACKGROUND DATA: The rate of PSF surgery has increased significantly. It remains the most common surgical procedure used to stabilize the spine; however, the impact of blood loss requiring blood transfusions remains a significant concern. METHODS: Analysis of data from the Canadian Spine Outcomes and Research Network. Patients who underwent PSF between 2008 and 2015 were identified. Multivariate analysis was used to identify predictors of blood transfusion from the collected information. RESULTS: Seven hundred seventy two patients have undergone PSF, 18% required blood transfusion, 54.8% were females and the mean age was 60 years. The analysis revealed five significant predictors: American Society of Anesthesiologist class (ASA), operative time, multilevel fusion, sacrum involvement, and open posterior approach. The odds of transfusion for those with ASA >1 were 6 times those with ASA1 (odds ratio [OR] 6.1, 95% confidence interval [CI] 1.4-27.1, P < 0.018). For each 60-minute increase in operative time, the odds of transfusion increased by 4.2% (OR 1.007, 95% CI 1.004-1.009, P < 0.001). The odds of transfusion were 6 times higher for multilevel fusion (OR 5.8, 95% CI 2.6-13.2, P < 0.001). Extending fusion to the sacrum showed 3 times higher odds for blood transfusion (OR 3.2, 95% CI 1.8-5.8, P < 0.001). The odds of transfusion for patients undergoing open approach were 12 times those who had minimal invasive surgery (OR 12.5, 95% CI 1.6-97.4, P < 0.016). Finally, patients receiving transfusions were more likely to have extended hospital stay. CONCLUSION: ASA >1, prolonged operative time, multilevel fusion, sacrum involvement, and open posterior approach were significant predictors of blood transfusion in PSF. LEVEL OF EVIDENCE: 3.

Comprehensive Review of Adipose Stem Cells and Their Implication in Distraction Osteogenesis and Bone Regeneration.

Bone is one of the most dynamic tissues in the human body that can heal following injury without leaving a scar. However, in instances of extensive bone loss, this intrinsic capacity of bone to heal may not be sufficient and external intervention becomes necessary. Several techniques are available to address this problem, including autogenous bone grafts and allografts. However, all these techniques have their own limitations. An alternative method is the technique of distraction osteogenesis, where gradual and controlled distraction of two bony segments after osteotomy leads to induction of new bone formation. Although distraction osteogenesis usually gives satisfactory results, its major limitation is the prolonged duration of time required before the external fixator is removed, which may lead to numerous complications. Numerous methods to accelerate bone formation in the context of distraction osteogenesis have been reported. A viable alternative to autogenous bone grafts for a source of osteogenic cells is mesenchymal stem cells from bone marrow. However, there are certain problems with bone marrow aspirate. Hence, scientists have investigated other sources for mesenchymal stem cells, specifically adipose tissue, which has been shown to be an excellent source of mesenchymal stem cells. In this paper, the potential use of adipose stem cells to stimulate bone formation is discussed.