Quantifying Patient Expectations for Total Knee Arthroplasty: Expectations for Improvement Are Greater Than Minimal Clinically Important Difference.

BACKGROUND: Achieving a minimal clinically important difference (MCID) in patient-reported outcomes following total knee arthroplasty (TKA) is common, yet up to 20% patient dissatisfaction persists. Unmet expectations may explain post-TKA dissatisfaction. No prior studies have quantified patient expectations using the same patient-reported outcome metric as used for MCID to allow direct comparison. METHODS: This was a prospective study of patients undergoing TKA with 5 fellowship-trained arthroplasty surgeons at one academic center. Baseline Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) domains were assessed. Expected PROMIS scores were determined by asking patients to indicate the outcomes they were expecting at 12 months postoperatively. Predicted scores were generated from a predictive model validated in the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR) dataset. T-tests were used to compare baseline, expected, and predicted PROMIS scores. Expected scores were compared to PROMIS MCID values obtained from the literature. Regression models were used to identify patient characteristics associated with high expectations. RESULTS: There were 93 patients included. Mean age was 67 years (range, 30 to 85) and 55% were women. Mean baseline PROMIS PF and PI was 34.4 ± 6.7 and 62.2 ± 6.4, respectively. Patients expected significant improvement for PF of 1.9 times the MCID (MCID = 11.3; mean expected improvement = 21.6, 95% confidence interval [CI] 19.6 to 23.5, P < .001) and for PI of 2.3 times the MCID (MCID = 8.9; mean expected improvement = 20.6, 95% CI 19.1-22.2, P < .001). Predicted scores were significantly lower than expected scores (mean difference = 9.5, 95% CI 7.7 to 11.3, P < .001). No unique patient characteristics were associated with high expectations (P > .05). CONCLUSIONS: To our knowledge, this study is the first to quantify preoperative patient expectations using the same metric as MCID to allow for direct comparison. Patient expectations for improvement following TKA are ∼2× greater than MCID and are significantly greater than predicted outcome scores. This discrepancy challenges currently accepted standards of success after TKA and indicates a need for improved expectation setting prior to surgery.

Imageless robotic total knee arthroplasty determines similar coronal plane alignment of the knee (CPAK) parameters to long leg radiographs.

BACKGROUND: The coronal plane alignment of the knee (CPAK) classification was first developed using long leg radiographs (LLR) and has since been reported using image-based and imageless robotic total knee arthroplasty (TKA) systems. However, the correspondence between imageless robotics and LLR-derived CPAK parameters has yet to be investigated. This study therefore examined the differences in CPAK parameters determined with LLR and imageless robotic navigation using either generic or optimized cartilage wear assumptions. METHODS: Medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA) were determined from the intraoperative registration data of 61 imageless robotic TKAs using either a generic 2 mm literature-based wear assumption (Navlit) or an optimized wear assumption (Navopt) found using an error minimization algorithm. MPTA and LDFA were also measured from preoperative LLR by two observers and intraclass correlation coefficients (ICCs) were calculated. MPTA, LDFA, joint line obliquity (JLO), and arithmetic hip-knee-ankle angle (aHKA) were compared between the robotic and the average LLR measurements over the two observers. RESULTS: ICCs between observers for LLR were over 0.95 for MPTA, LDFA, JLO, and aHKA, indicating excellent agreement. Mean CPAK differences were not significant between LLR and Navlit (all differences within 0.6°, P > 0.1) or Navopt (all within 0.1°, P > 0.83). Mean absolute errors (MAE) between LLR and Navlit were: LDFA = 1.4°, MPTA = 2.0°, JLO = 2.1°, and aHKA = 2.7°. Compared to LLR, the generic wear classified 88% and the optimized wear classified 94% of knees within one CPAK group. Bland-Altman comparisons reported good agreement for LLR vs. Navlit and Navopt, with > 95% and > 91.8% of measurements within the limits of agreement across all CPAK parameters, respectively. CONCLUSIONS: Imageless robotic navigation data can be used to calculate CPAK parameters for arthritic knees undergoing TKA with good agreement to LLR. Generic wear assumptions determined MPTA and LDFA with MAE within 2° and optimizing wear assumptions showed negligible improvement.

Racial and Ethnic Minorities Underrepresented in Pain Management Guidelines for Total Joint Arthroplasty: A Meta-analysis.

BACKGROUND: Total joint arthroplasty aims to improve quality of life and functional outcomes for all patients, primarily by reducing their pain. This goal requires clinical practice guidelines (CPGs) that equitably represent and enroll patients from all racial/ethnic groups. To our knowledge, there has been no formal evaluation of the racial/ethnic composition of the patient population in the studies that informed the leading CPGs on the topic of pain management after arthroplasty surgery. QUESTIONS/PURPOSES: Using papers included in the 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines and comparing them with US National census data, we asked: (1) What is the representation of racial/ethnic groups in randomized controlled trials compared with their representation in the US national population? (2) Is there a relationship between the reporting of racial/ethnic groups and year of data collection/publication, location of study, funding source, or guideline section? METHODS: Participant demographic data (study year published, study type, guideline section, year of data collection, study site, study funding, study size, gender, age, and race/ethnicity) were collected from articles cited by this guideline. Studies were included if they were full text, were primary research articles conducted primarily within the United States, and if they reported racial and ethnic characteristics of the participants. The exclusion criteria included duplicate articles, articles that included the same participant population (only the latest dated article was included), and the following article types: systematic reviews, nonsystematic reviews, terminology reports, professional guidelines, expert opinions, population-based studies, surgical trials, retrospective cohort observational studies, prospective cohort observational studies, cost-effectiveness studies, and meta-analyses. Eighty-two percent (223 of 271) of articles met inclusion criteria. Our original literature search yielded 27 papers reporting the race/ethnicity of participants, including 24 US-based studies and three studies conducted in other countries; only US-based studies were utilized as the focus of this study. We defined race/ethnicity reporting as the listing of participants' race or ethnicity in the body, tables, figures, or supplemental data of a study. National census information from 2000 to 2019 was then used to generate a representation quotient (RQ), which compared the representation of racial/ethnic groups within study populations to their respective demographic representation in the national population. An RQ value greater than 1 indicates an overrepresented group and an RQ value less than 1 indicates an underrepresented group, relative to the US population. Primary outcome measures of RQ value versus time of publication for each racial/ethnic group were evaluated with linear regression analysis, and race reporting and manuscript parameters were analyzed with chi-square analyses. RESULTS: Two US-based studies reported race and ethnicity independently. Among the 24 US-based studies reporting race/ethnicity, the overall RQ was 0.70 for Black participants, 0.09 for Hispanic participants, 0.1 for American Indian/Alaska Natives, 0 for Native Hawaiian/Pacific Islanders, 0.08 for Asian participants, and 1.37 for White participants, meaning White participants were overrepresented by 37%, Black participants were underrepresented by 30%, Hispanic participants were underrepresented by 91%, Asian participants were underrepresented by 92%, American Indian/Alaska Natives were 90% underrepresented, and Native Hawaiian Pacific Islanders were virtually not represented compared with the US national population. On chi-square analysis, there were differences between race/ethnicity reporting among studies with academic, industry, and dual-supported funding sources (χ2 = 7.449; p = 0.02). Differences were also found between race/ethnicity reporting among US-based and non-US-based studies (χ2 = 36.506; p < 0.001), with 93% (25 of 27) of US-based studies reporting race as opposed to only 7% (2 of 27) of non-US-based studies. Finally, there was no relationship between race/ethnicity reporting and the year of data collection or guideline section referenced. CONCLUSION: The 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines provide evidence-based recommendations that reflect the current standards in orthopaedic surgery, but the studies upon which they are based overwhelmingly underenroll and underreport racial/ethnic minorities relative to their proportions in the US population. As these factors impact analgesic administration, their continued neglect may perpetuate inequities in outcomes after TJA. CLINICAL RELEVANCE: Our study demonstrates that all non-White racial/ethnic groups were underrepresented relative to their proportion of the US population in the 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines, underscoring a weakness in the orthopaedic surgery evidence base and questioning the overall external validity and generalizability of these combined CPGs. An effort should be made to equitably enroll and report outcomes for all racial/ethnic groups in any updated CPGs.

Peptidoglycan in osteoarthritis synovial tissue is associated with joint inflammation.

OBJECTIVES: Peptidoglycan (PG) is an arthritogenic bacterial cell wall component whose role in human osteoarthritis is poorly understood. The purpose of this study was to determine if PG is present in synovial tissue of osteoarthritis patients at the time of primary total knee arthroplasty (TKA), and if its presence is associated with inflammation and patient reported outcomes. METHODS: Intraoperative synovial tissue and synovial fluid samples were obtained from 56 patients undergoing primary TKA, none of whom had history of infection. PG in synovial tissue was detected by immunohistochemistry (IHC) and immunofluorescence microscopy (IFM). Synovial tissue inflammation and fibrosis were assessed by histopathology and synovial fluid cytokine quantification. Primary human fibroblasts isolated from arthritis synovial tissue were stimulated with PG to determine inflammatory cytokine response. RESULTS: A total of 33/56 (59%) of primary TKA synovial tissue samples were positive for PG by IHC, and PG staining colocalized with markers of synovial macrophages and fibroblasts by IFM. Synovial tissue inflammation and elevated IL-6 in synovial fluid positively correlated with PG positivity. Primary human fibroblasts stimulated with PG secreted high levels of IL-6, consistent with ex vivo findings. Interestingly, we observed a significant inverse correlation between PG and age at time of TKA, indicating younger age at time of TKA was associated with higher PG levels. CONCLUSION: Peptidoglycan is commonly found in synovial tissue from patients undergoing TKA. Our data indicate that PG may play an important role in inflammatory synovitis, particularly in patients who undergo TKA at a relatively younger age.

The Role of the Gut Microbiome in Orthopedic Surgery-a Narrative Review.

PURPOSE OF REVIEW: The importance of the gut microbiome has received increasing attention in recent years. New literature has revealed significant associations between gut health and various orthopedic disorders, as well as the potential for interventions targeting the gut microbiome to prevent disease and improve musculoskeletal outcomes. We provide a broad overview of available literature discussing the links between the gut microbiome and pathogenesis and management of orthopedic disorders. RECENT FINDINGS: Human and animal models have characterized the associations between gut microbiome dysregulation and diseases of the joints, spine, nerves, and muscle, as well as the physiology of bone formation and fracture healing. Interventions such as probiotic supplementation and fecal transplant have shown some promise in ameliorating the symptoms or slowing the progression of these disorders. We aim to aid discussions regarding optimization of patient outcomes in the field of orthopedic surgery by providing a narrative review of the available evidence-based literature involving gut microbiome dysregulation and its effects on orthopedic disease. In general, we believe that the gut microbiome is a viable target for interventions that can augment current management models and lead to significantly improved outcomes for patients under the care of orthopedic surgeons.

Hemiarthroplasty Versus Total Hip Arthroplasty for Femoral Neck Fracture in Elderly Patients: Twelve-Month Risk of Revision and Dislocation in an Instrumental Variable Analysis of Medicare Data.

BACKGROUND: There is practice variation in the selection of a total hip arthroplasty (THA) or a hemiarthroplasty (HA) for the treatment of displaced femoral neck fractures in elderly patients. Large data sets are needed to compare the rates of rare complications following these procedures. We sought to examine the relationship between surgery type and secondary hip surgery (revision or conversion arthroplasty) at 12 months following the index arthroplasty, and that between surgery type and dislocation at 12 months, among elderly Medicare beneficiaries who underwent THA or HA for a femoral neck fracture, taking into account the potential for selection bias. METHODS: We performed a population-based, retrospective study of elderly (>65 years of age) Medicare beneficiaries who underwent THA or HA following a femoral neck fracture. Two-stage, instrumental variable regression models were applied to nationally representative Medicare medical claims data from 2017 to 2019. RESULTS: Of the 61,695 elderly patients who met the inclusion criteria, of whom 74.1% were female and 92.2% were non-Hispanic White, 10,268 patients (16.6%) underwent THA and 51,427 (83.4%) underwent HA. The findings from the multivariable, instrumental variable analyses indicated that treatment of displaced femoral neck fractures with THA was associated with a significantly higher risk of dislocation at 12 months compared with treatment with HA (2.9% for the THA group versus 1.9% for the HA group; p = 0.001). There was no significant difference in the likelihood of 12-month revision/conversion between THA and HA. CONCLUSIONS: The use of THA to treat femoral neck fractures in elderly patients is associated with a significantly higher risk of 12-month dislocation, as compared with the use of HA, although the difference may not be clinically important. A low overall rate of dislocation was found in both groups. The risk of revision/conversion at 12 months did not differ between the groups. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The Impact of Femoral Component Cementation on Fracture and Mortality Risk in Elective Total Hip Arthroplasty: Analysis from a National Medicare Sample.

BACKGROUND: Complications following elective total hip arthroplasty (THA) are rare but potentially devastating. The impact of femoral component cementation on the risk of periprosthetic femoral fractures and early perioperative death has not been studied in a nationally representative population in the United States. METHODS: Elective primary THAs performed with or without cement among elderly patients were identified from Medicare claims from 2017 to 2018. We performed separate nested case-control analyses matched 1:2 on age, sex, race/ethnicity, comorbidities, payment model, census division of facility, and exposure time and compared fixation mode between (1) groups with and without 90-day periprosthetic femoral fracture and (2) groups with and without 30-day mortality. RESULTS: A total of 118,675 THAs were included. The 90-day periprosthetic femoral fracture rate was 2.0%, and the 30-day mortality rate was 0.18%. Cases were successfully matched. The risk of periprosthetic femoral fracture was significantly lower among female patients with cement fixation compared with matched controls with cementless fixation (OR = 0.83; 95% CI, 0.69 to 1.00; p = 0.05); this finding was not evident among male patients (p = 0.94). In contrast, the 30-day mortality risk was higher among male patients with cement fixation compared with matched controls with cementless fixation (OR = 2.09; 95% CI, 1.12 to 3.87; p = 0.02). The association between cement usage and mortality among female patients almost reached significance (OR = 1.74; 95% CI, 0.98 to 3.11; p = 0.06). CONCLUSIONS: In elderly patients managed with THA, cemented stems were associated with lower rates of periprosthetic femoral fracture among female patients but not male patients. The association between cemented stems and higher rates of 30-day mortality was significant for male patients and almost reached significance for female patients, although the absolute rates of mortality were very low. For surgeons who can competently perform THA with cement, our data support the use of a cemented stem to avoid periprosthetic femoral fracture in elderly female patients. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Knee Arthrofibrosis following Tibial Plateau Fracture Treated with Arthroscopic Lysis of Adhesions with Manipulation.

Posttraumatic arthrofibrosis is a common problem encountered in the orthopaedic setting for which there is no agreement on the optimal management strategy. The literature does not optimally describe the efficacy of arthroscopic lysis of adhesions for arthrofibrosis following tibial plateau fracture. The purpose of this study is to quantify the efficacy of arthroscopic lysis of adhesions with manipulation for the treatment of arthrofibrosis of the knee in patients who previously underwent surgical management of tibial plateau fracture. All patients who underwent arthroscopic lysis of adhesions from a single surgeon since 1999 were retrospectively reviewed. Clinical outcomes were evaluated by flexion, extension, and range of motion (ROM) preoperatively, intraoperatively, and postoperatively at intervals of 1, 4, 8, and 12 weeks, and any additional long-term follow-up. A total of 28 patients who had developed arthrofibrosis following surgical management of a tibial plateau fracture and failed nonsurgical management of knee stiffness were included in this study. There were significant improvements in total ROM following intervention at all time points compared with preoperative values (p < 0.001), with mean improvements of 59.3 degrees intraoperatively, 32.9 degrees (1 week), 37.1 degrees (4 weeks), 41.5 degrees (8 weeks), and 47.6 degrees (12 weeks). There were significant improvements in degrees of knee flexion following intervention at all time points compared with preoperative values (p < 0.001), with mean improvements of 50.8 degrees intraoperatively, 27.3 degrees (1 week), 36.0 degrees (4 weeks), 38.3 degrees (8 weeks), and 43.9 degrees (12 weeks). There were significant increases in degrees of knee extension intraoperatively (8.5 degrees) and at 1 week postoperatively (5.9 degrees) compared with preoperative values (p <0.01). At 12 weeks postoperatively, those who had previously undergone external fixation had significantly greater increases in ROM (p = 0.048). Arthroscopic lysis of adhesions for knee arthrofibrosis following surgical management of tibial plateau fracture significantly improves knee ROM.

Association Between Nonsurgical Weight Loss From Body Mass Index >40 to Body Mass Index <40 and Complications and Readmissions Following Total Hip Arthroplasty.

BACKGROUND: Elevated body mass index (BMI) is a risk factor for adverse outcomes following total hip arthroplasty (THA). It is unknown if preoperative weight loss to a BMI <40 kg/m2 is associated with reduced risk of adverse outcomes. METHODS: We retrospectively reviewed elective, primary THA performed at an academic center from 2015 to 2019. Patients were split into groups based on their BMI trajectory prior to THA: BMI consistently <40 ("BMI <40"); BMI >40 at the time of surgery ("BMI >40"); and BMI >40 within 2 years preoperatively, but <40 at the time of surgery ("Weight Loss"). Length of stay (LOS), 30-day readmissions, and complications as defined by Centers for Medicare and Medicaid Services were compared between groups using parsimonious regression models and Fisher's exact testing. Adjusted analyses controlled for sex, age, and American Society of Anesthesiologists class. RESULTS: In total, 1589 patients were included (BMI <40: 1387, BMI >40: 96, Weight Loss: 106). The rate of complications in each group was 3.5%, 6.3%, and 8.5% and the rate of 30-day readmissions was 3.0%, 4.2%, and 7.5%, respectively. Compared to the BMI <40 group, the weight loss group had a significantly higher risk of 30-day readmission (odds ratio [OR] 2.70, 95% confidence interval [CI] 1.19-6.17, P = .02), higher risk of any complication (OR 2.47, 95% CI 1.09-5.59, P = .03), higher risk of mechanical complications (OR 3.07, 95% CI 1.14-8.25, P = .03), and longer median LOS (16% increase, P = .002). The BMI >40 group had increased median LOS (10% increase, P = .03), but no difference in readmission or complications (P > .05) compared to BMI <40. CONCLUSION: Weight loss from BMI >40 to BMI <40 prior to THA was associated with increased risk of readmission and complications compared to BMI <40, whereas BMI >40 was not. LEVEL OF EVIDENCE: Level III - Retrospective Cohort Study.

What Mid-term Patient-reported Outcome Measure Scores, Reoperations, and Complications Are Associated with Concurrent Hip Arthroscopy and Periacetabular Osteotomy to Treat Dysplasia with Associated Intraarticular Abnormalities?

BACKGROUND: Periacetabular osteotomy (PAO) is a well-accepted treatment for acetabular dysplasia, but treatment success is not uniform. Concurrent hip arthroscopy has been proposed for select patients to address intraarticular abnormalities. The patient-reported outcomes, complications, and reoperations for concurrent arthroscopy and PAO to treat acetabular dysplasia remain unclear. QUESTIONS/PURPOSES: (1) What are the functional outcome scores among select patients treated with PAO plus concurrent hip arthroscopy at mid-term follow-up? (2) What factors are associated with conversion to THA or persistent symptoms (modified Harris hip score ≤ 70 or WOMAC pain subscore ≥ 10)? (3) What proportion of patients underwent further hip preservation surgery at mid-term follow-up? (4) What are the complications associated with the procedure? METHODS: Between November 2005 and December 2012, 78 patients (81 hips) who presented with symptomatic acetabular dysplasia-defined as a lateral center-edge angle less than 20° with hip pain for more than 3 months that interfered with daily function-had undergone unsuccessful nonsurgical treatment, had associated intraarticular abnormalities on MRI, and underwent combined hip arthroscopy and PAO. Eleven patients did not have minimum 4-year follow-up and were excluded, leaving 67 patients (70 hips) who met our inclusion criteria and had a mean follow-up duration of 6.5 ± 1.6 years. We retrospectively evaluated patient-reported outcomes at final follow-up using the University of California Los Angeles (UCLA) activity score, the modified Harris Hip Score (mHHS), and the WOMAC pain subscore. Conversion to THA or persistent symptoms were considered clinical endpoints. Repeat surgical procedures were drawn from a prospectively maintained database, and major complications were graded according to the validated Clavien-Dindo classification (Grade III or IV). Student t-tests, chi-square tests, and Fisher exact tests identified the association of patient factors, radiographic measures, and surgical details with clinical endpoints. For patients who underwent bilateral procedures, only the first hip was included in our analyses. RESULTS: At final follow-up, the mean mHHS for all patients improved from a mean ± SD of 55 ± 19 points to 85 ± 17 points (p < 0.001), the UCLA activity score improved from 6.5 ± 2.7 points to 7.5 ± 2.2 points (p = 0.01), and the WOMAC pain score improved from 9.1 ± 4.3 points to 3.2 ± 3.9 points (p < 0.001). Three percent (2 of 67) of patients underwent subsequent THA, while 21% (15 of 70) of hips were persistently symptomatic, defined as mHHS less than or equal to 70 or WOMAC pain subscore greater than or equal to 10. Univariate analyses indicated that no patient demographics, preoperative or postoperative radiographic metrics, or intraoperative findings or procedures were associated with subsequent THA or symptomatic hips. Worse baseline mHHS and WOMAC pain scores were associated with subsequent THA or symptomatic hips. Seven percent (5 of 67) of patients underwent repeat hip preservation surgery for recurrent symptoms, and 4% (3 of 67) of patients had major complications (Clavien-Dindo Grade III or IV). CONCLUSION: This study demonstrated that concurrent hip arthroscopy and PAO to treat symptomatic acetabular dysplasia (with intraarticular abnormalities) has good clinical outcomes at mid-term follow-up in many patients; however, persistent symptoms or conversion to THA affected almost a quarter of the sample. We noted an acceptable complication profile. Further study is needed to directly compare this approach to more traditional techniques that do not involve arthroscopy. We do not use isolated hip arthroscopy to treat symptomatic acetabular dysplasia. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The Effect of Implant Design on Sagittal Plane Stability: A Randomized Trial of Medial- versus Posterior-Stabilized Total Knee Arthroplasty.

Up to 20% of total knee arthroplasty (TKA) patients report dissatisfaction with their outcome, especially with weight-bearing in flexion (WBiF) activities. Sagittal plane instability may contribute to dissatisfaction following TKA. We assessed the impact of implant design on TKA sagittal plane stability and clinical satisfaction. We randomized patients to receive one of two TKA implant designs: medial-stabilized (MS) or posterior-stabilized (PS). Sagittal stability was assessed using a KT-1000 arthrometer. Patient-reported outcome measures, including a custom bank of questions targeting patient satisfaction (0-100%) with WBiF activities, were administered to patients 2 years following surgery. The final analysis included 50 patients (25 MS, 25 PS). The MS group had greater sagittal plane stability than the PS group at 30-degree flexion (5.6 ± 1.9 vs. 10.2 ± 2.7 mm; p < 0.0001) but not at 90-degree flexion (4.1 ± 2 vs. 5.3 ± 3 mm; p = 0.14). Range of motion was not different (111.3 ± 10.4 vs. 114.7 ± 10.7 degrees; p = 0.31). There were no differences in the PROMIS (Patient-Reported Outcomes Measurement Information System) score, Oxford Knee Score, Knee Society Score, Forgotten Joint Score, or Veterans Rand. The MS group had no difference in satisfaction for WBiF activities versus non-WBiF activities (80.5 ± 18 vs. 88.3% ± 16.4%; p = 0.13), whereas the PS group had significantly worse satisfaction for WBiF versus non-WBiF activities (71.6 ± 24.6 vs. 87.8% ± 16.6%; p = 0.019). An MS prosthetic design was more stable in the sagittal plane in midflexion compared with a PS design. There was no difference in patient-reported outcomes, although custom survey data suggest improved satisfaction with MS design during WBiF activities.

ANCHOR surgeon views of patient selection and expectations for periacetabular osteotomy.

Preoperative expectations impact shared decision making and patient satisfaction. Surgeon views of patient selection, expected outcomes and patient expectations after periacetabular osteotomy (PAO) for treatment of acetabular dysplasia have not been defined. We assessed surgeon views of patient selection and expected outcomes after PAO. A sample of experienced PAO surgeons participated in semi-structured phone interviews assessing: (i) factors that determine patient candidacy for PAO; (ii) surgeon expectations for PAO outcomes; (iii) surgeon perceptions of patient expectations for PAO outcomes and (iv) surgeon perceptions of discrepancies in surgeon and patient expectations and approaches for reconciling these discrepancies. Twelve surgeons (77% of PAO-performing ANCHOR surgeons) participated. The factors most commonly mentioned in determining patient candidacy for PAO were: symptoms, radiographic findings, absence of arthritis and age. Only one-quarter of the sample mentioned patient expectations as a factor in determining patient candidacy for PAO. The most common surgeon expectations were: pain reduction, joint preservation, function with activities of daily living and return to desired activities. 58% of surgeons felt that surgeon and patient expectations align most of the time. Common expectation discrepancies included return to unrestricted activities and complete pain relief. Detailed discussion was the most commonly employed strategy to resolve expectation discrepancies. PAO surgeons felt that patient expectations of complete pain relief and return to unrestricted activities were misaligned with their own expectations. Development of an expectations survey may facilitate shared decision making.

Complications associated with combined surgical hip dislocation and periacetabular osteotomy for complex hip deformities.

Surgical hip dislocation (SD) and periacetabular osteotomy (PAO) are well-described treatments for femoroacetabular impingement (FAI) and acetabular dysplasia, respectively. Occasionally, complex deformities require a combined SD/PAO; the morbidity of performing both procedures in a single stage has not been fully investigated. We performed a retrospective review of a consecutive group of patients undergoing combined SD/PAO to investigate the incidence and character of perioperative complications. Forty-five patients (46 hips) were identified. Perioperative complications were graded by the modified Clindo-Davien complication scheme. Mean follow-up was 36 months (range 12-128), and no patients were lost to follow-up. Six complications occurred in six hips (13%). Four (8.7%) complications were minor (Grades I or II): one Brooker Grade III heterotopic ossification requiring no treatment, one superior pubic ramus nonunion requiring no treatment and two superficial wound infections requiring antibiotics. Two (4.3%) complications were major (Grades III or IV): one coxa saltans interna and labral tear requiring hip arthroscopy with labral repair and iliopsoas lengthening, and one deep surgical site infection requiring irrigation and debridement followed by development of arthritis requiring conversion to arthroplasty. The average Harris hip score improved from 62 ± 13 preoperatively to 80 ± 19 at final follow-up. Except for the single joint replacement, there were no long-term disabilities. There were no major neurovascular injuries, osteonecrosis, fractures or trochanteric nonunions. Combined SD/PAO for the treatment of complex, concomitant deformities of the proximal femur and acetabulum is associated with an acceptable risk of complications. The vast majority of complications that occurred were managed without permanent disability. Level of Evidence: IV.

Risk Factors for Prolonged Postoperative Opioid Use After Spine Surgery: A Review of Dispensation Trends From a State-run Prescription Monitoring Program.

INTRODUCTION: Opioid abuse and dependence have a detrimental effect on elective orthopaedic surgeries, yet pain control is an important predictor of postoperative satisfaction. We aimed at better defining risk factors for prolonged postoperative opioid requirements and risk factors for patients requiring higher doses of opioids after spine surgery. METHODS: The Illinois Prescription Monitoring Program was queried to analyze opioid dispensation patterns at 3 and 6 months postoperatively for adult patients who had spine surgery at a tertiary care hospital by a single surgeon over a 5-year period. Patients were divided into three groups: group 1 patients had opioid dispensed to them 3 and 6 months preoperatively, group 2 patients had opioid dispensed to them only at 3 months preoperatively, and group 3 patients did not have preoperative opioid prescriptions. Demographic characteristics, psychiatric history, smoking status, alcohol use, body mass index, surgical region, and presence of multiple prescribers were abstracted. Statistical analysis included multivariate modified Poisson regression, linear regression, and chi-squared testing when appropriate. RESULTS: Patients in group 1 were at significantly increased risk of continued opioid usage than those in group 2 (relative risk, 3.934; 95% confidence interval, 1.691 to 9.150; P = 0.0015) and those in group 3 (relative risk, 4.004; 95% confidence interval, 1.712 to 9.365; P = 0.0014) at 6 months postoperatively. Group 1 patients also had larger quantities of opioid dispensed to them relative to patients in group 2 or group 3 (P < 0.0001) at 6 months postoperatively. DISCUSSION: Use of opioid medications at 6 months preoperatively is a risk factor for continued usage and at higher doses 6 months postoperatively. LEVEL OF EVIDENCE: Level III: retrospective cohort study.

Nephrotoxicity After the Treatment of Periprosthetic Joint Infection With Antibiotic-Loaded Cement Spacers.

BACKGROUND: Treatment of periprosthetic joint infections commonly involves insertion of an antibiotic-loaded cement spacer (ACS). The risk for acute kidney injury (AKI) related to use of antibiotic spacers has not been well defined. We aimed to identify the incidence of and risk factors for AKI after placement of an ACS. METHODS: We performed a prospective cohort study of patients with an infected primary total hip or knee arthroplasty treated with ACSs with vancomycin, gentamicin, and tobramycin. Serum creatinine and glomerular filtration rate data were collected at baseline and weekly intervals for 8 weeks. Patients were classified into Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) stages to determine incidence of AKI. Risk factors for kidney injury were identified via regression analysis. RESULTS: A total of 37 patients (20 total knee arthroplasty and 17 total hip arthroplasty) were included. During the 8 weeks after ACS placement, 10 patients (27%) fit RIFLE criteria for kidney injury and 2 patients (5%) fit RIFLE criteria for kidney failure. No baseline patient characteristics were associated with development of AKI. CONCLUSION: Patients should be monitored closely for development of AKI after placement of ACSs for the treatment of periprosthetic joint infection. Further research into minimizing risk for AKI is warranted.

Risk Factors for Postoperative Infections After Single-Level Lumbar Fusion Surgery.

STUDY DESIGN: Retrospective multivariate analysis of a prospectively collected, multicenter database. OBJECTIVE: To identify patient characteristics and perioperative risk factors associated with postoperative infectious complications after single-level lumbar fusion (SLLF) surgery. SUMMARY OF BACKGROUND DATA: Postoperative infection is a known complication after lumbar fusion. Risk factors for infectious complications after lumbar fusion have not been investigated using select set of SLLF procedures. METHODS: Patients who underwent SLLF between 2006 and 2011 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Multivariate logistic regression analyses were performed to identify pre- and intraoperative risk factors associated with postoperative infection. RESULTS: A total of 3353 patients were analyzed in this study. Overall, 173 (5.2%) patients experienced a postoperative infection, including 86 (2.6%) surgical site infections (SSIs) and 111 (3.3%) non-SSI infectious complications (pneumonia, urinary tract infection, sepsis/septic shock). Twenty-four (0.7%) patients experienced both SSI and non-SSI infectious complications. Postoperative SSI were associated with obesity (odds ratio [OR], 1.628; 95% confidence interval [CI], 1.042-2.544), American Society of Anesthesiologists class more than 2 (OR, 2.078; 95% CI, 1.309-3.299), and operative time more than 6 hours (OR, 2.573; 95% CI, 1.310-5.056). Risk factors for non-SSI infectious complications included age (60-69 yr; OR, 3.279; 95% CI, 1.541-6.980; and ≥70 yr; OR, 3.348; 95% CI, 1.519-7.378), female sex (OR, 1.791; 95% CI, 1.183-2.711), creatinine more than 1.5 mg/dL (OR, 2.400; 95% CI, 1.138-5.062), American Society of Anesthesiologists class more than 2 (OR, 1.835; 95% CI, 1.177-2.860), and operative time more than 6 hours (OR, 3.563; 95% CI, 2.082-6.097). CONCLUSION: Across a wide study population, we identified that obesity, advanced American Society of Anesthesiologists classification, and longer operative time were predictive of postoperative SSI. We also demonstrated that increased age, female sex, serum creatinine more than 1.5 mg/dL, and prolonged operative duration are associated with non-SSI infectious complications after SLLF. Continued efforts to elucidate and optimize perioperative risk factors are warranted to improve outcomes in patients requiring spinal fusion. LEVEL OF EVIDENCE: 3.

Systemic Absorption of Antibiotics From Antibiotic-Loaded Cement Spacers for the Treatment of Periprosthetic Joint Infection.

BACKGROUND: Two-stage treatment of periprosthetic joint infections involves placement of high-dose antibiotic-loaded cement spacers (ACSs). Reports of ACS-induced nephrotoxicity have raised concern regarding systemic absorption of antibiotics after ACS placement. We sought to characterize the serum concentrations of antibiotics that occur after ACS placement. METHODS: We performed a prospective study of patients with an infected primary total hip (THA) or knee arthroplasty (TKA) treated with standardized ACSs with vancomycin, gentamicin, and tobramycin. Serum antibiotic levels were collected weekly for 8 weeks. RESULTS: Twenty-one patients (10 THA, 11 TKA) were included. Mean serum gentamicin levels ranged between 0.275±0.046 and 0.364±0.163 mg/L; mean serum tobramycin levels ranged from 0.313±0.207 to 0.527±0.424 mg/L; and mean serum vancomycin levels ranged from 5.46±6.6 to 15.34±9.6 mg/L. Serum antibiotic levels were detectable throughout the 8-week duration of ACS treatment. Regression analysis found that diabetes (coefficient 6.73, 95% CI 0.92-12.54, P < .05), blood urea nitrogen (coefficient 0.83, 95% CI 0.45-1.22, P < .001), number of cement doses (coefficient 3.71, 95% CI 0.76-6.66, P < .05), and use of systemic vancomycin (coefficient 6.24, 95% CI 2.72-9.75, P < .001) correlated with serum vancomycin levels. Patient age (coefficient -0.01, 95% CI -0.02 to 0, P < .01) and male sex (coefficient 0.20, 95% CI 0-0.41, P < .05) correlated with serum aminoglycoside level. CONCLUSION: Systemic absorption of antibiotics from high-dose ACS persists for at least 8 weeks. Patients should be monitored closely for complications related to systemic absorption of antibiotics from ACS treatment.

Chronic Anterior Pelvic Instability: Diagnosis and Management.

Chronic anterior pelvic ring instability can cause pain and disability. Pain typically is localized to the suprapubic area or inner thigh; often is associated with lower back or buttock pain; and may be exacerbated by activity, direct impact, or pelvic ring compression. Known etiologies of chronic anterior pelvic ring instability include pregnancy, parturition, trauma, insufficiency fractures, athletics, prior surgery, and osteitis pubis. Diagnosis often is delayed. Physical examination may reveal an antalgic or waddling gait, tenderness over the pubic bones or symphysis pubis, and pain with provocative maneuvers. AP pelvic radiographs may demonstrate chronic degenerative changes at the pubic symphysis or nonhealing fractures. Standing single leg stance (flamingo view) radiographs can demonstrate pathologic motion at the pubic symphysis. CT may be useful in assessing posterior pelvic ring involvement. The initial management is typically nonsurgical and may include the use of an orthosis, activity modification, medication, and physical therapy. If nonsurgical modalities are unsuccessful, surgery may be warranted, although little evidence exists to guide treatment. Surgical intervention may include internal fixation alone in select patients, the addition of bone graft to fixation, or symphyseal arthrodesis. In some patients, additional stabilization or arthrodesis of the posterior pelvic ring may be indicated.

Intra-Articular Vancomycin Powder Eliminates Methicillin-Resistant S. aureus in a Rat Model of a Contaminated Intra-Articular Implant.

BACKGROUND: Periprosthetic joint infection following hip and knee arthroplasty leads to poor outcomes and exorbitant costs. Topical vancomycin powder has been shown to decrease infection in many procedures such as spine surgery. The role of vancomycin powder in the setting of total joint arthroplasty remains undefined. Our aim was to evaluate the efficacy of intra-articular vancomycin powder in preventing infection in a rat model of a contaminated intra-articular implant. METHODS: Thirty-two female Sprague-Dawley rats underwent knee arthrotomy and implantation of a femoral intramedullary wire with 1 mm of intra-articular communication. The knee joint was also inoculated with 1.5 × 10 colony forming units (CFU)/mL of methicillin-resistant Staphylococcus aureus (MRSA). Four treatment groups were studied: (1) no antibiotics (control), (2) preoperative systemic vancomycin, (3) intra-articular vancomycin powder, and (4) both systemic vancomycin and intra-articular vancomycin powder. The animals were killed on postoperative day 6, and distal femoral bone, joint capsule, and the implanted wire were harvested for bacteriologic analysis. Statistical analyses were performed using Wilcoxon rank sum and Fisher exact tests. RESULTS: There were no postoperative deaths, wound complications, signs of vancomycin-related toxicity, or signs of systemic illness in any of the treatment groups. There were significantly fewer positive cultures in the group that received vancomycin powder in combination with systemic vancomycin compared with the group that received systemic vancomycin alone (bone: 0% versus 75% of 8, p = 0.007; Kirschner wire: 0% versus 63% of 8, p = 0.026; whole animal: 0% versus 88% of 8, p = 0.01). Only animals that received both vancomycin powder and systemic vancomycin showed evidence of complete elimination of bacterial contamination. CONCLUSIONS: In a rat model of a contaminated intra-articular implant, use of intra-articular vancomycin powder in combination with systemic vancomycin completely eliminated MRSA bacterial contamination. Animals treated with systemic vancomycin alone had persistent MRSA contamination. CLINICAL RELEVANCE: This animal study presents data suggesting that the use of intra-articular vancomycin powder for reducing the risk of periprosthetic joint infections should be investigated further in clinical studies.

Osteochondroma With Contiguous Bronchogenic Cyst of the Scapula.

Osteochondroma is a benign bone tumor composed of a bony protrusion with an overlying cartilage cap. Osteochondromas arise in the scapula in 3% to 5% of cases, making them the most common benign bone tumor in this location. Scapular osteochondromas cause various pathologies of the shoulder girdle, including snapping scapula syndrome, chest wall deformity, shoulder impingement, and bursa formation. Bronchogenic cyst is an exceedingly rare finding in the periscapular area. It is a congenital cystic mass lined by tracheobronchial structures and respiratory epithelium. To our knowledge, there are no reports of a contiguous osteochondroma and bronchogenic cyst. A 12-month-old boy presented with an incidentally noted mass on the spine of the scapula, which drained scant, clear fluid through an adjacent pinprick-sized hole. Imaging revealed an exostosis with an adjacent cystic mass. The mass and cyst were excised en bloc, and histopathologic examination confirmed the diagnosis of osteochondroma with contiguous bronchogenic cyst. In this case, we present the report of a novel dual lesion.