Do nonagenarians have more complications and unplanned readmissions than octogenarians following primary THA? A retrospective cohort study.

INTRODUCTION: The performance of total hip arthroplasty in elderly patients, especially nonagenarians, is challenging due to higher patient frailty and medical comorbidities. We compared 90-day postoperative complications and unplanned readmissions between nonagenarians and octogenarians undergoing elective THA. METHODS: One hundred and eleven patients undergoing elective, unilateral THA were retrospectively analyzed. Forty-four patients were nonagenarians (Group A), and 67 patients were octogenarians (Group B). Demographic data included age, gender, body mass index (BMI), ASA score and Charlson Comorbidity Index (CCI). Frailty was defined according to the Rockwood Frailty Index. All patients underwent a thorough preoperative assessment through a specific institutional clinical pathway created for this matter. Postoperative adverse events were grouped into major or minor. A regression model was used to evaluate independent risk factors for the development of complications. RESULTS: There were no differences in the ASA score (65.9% vs. 53.7% ASA III-IV), prevalence of frailty (1% vs. 9%) and comorbidities between both groups (p > .05). The CCI was higher in nonagenarians (p = 0.007). Nonagenarians had more in-hospital complications, although most were minor (p = 0.002), none of which resulted in mortality. Ninety-day unplanned readmissions were similar between groups, with 4 (9.1%) and 6 (9%) in groups A and B, respectively (p = 1). Although age was a factor associated with the development of postoperative complications in the univariate regression model (OR 3.81, 95% CI 1.31 to 11.11, p = 0.014), it lost significance after performing the multivariate analysis (OR 2.48, 95% CI 0.78 to 7.90, p = 0.125). CONCLUSION: The age of 90 years old was not a barrier to perform elective THA safely. Nonagenarians had higher in-hospital minor complications when compared to the younger cohort. However, age over 90 years was not an independent risk factor for unplanned readmissions or mortality. Multimodal protocols of perioperative care are paramount for improving outcomes after THA in very old patients.

Feasibility of total hip arthroplasty in cerebral palsy patients: a systematic review on clinical outcomes and complications.

PURPOSE: Total hip arthroplasty (THA) is a successful treatment for hip osteoarthritis secondary to hip dysplasia. However, the reported rate of complications following THA in the settings of neuromuscular diseases is high. This systematic review aimed to analyze the indications, functional outcomes and surgical failures of primary THA in cerebral palsy (CP) patients. METHODS: MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews were searched, and all clinical studies focusing on THA in patients with CP from inception through March 2020 were included. The methodological quality was assessed with Guo et al.'s quality appraisal checklist for case series and case-control studies, while cohort and prospective studies were evaluated with a modified version of the Downs and Black's quality assessment checklist. RESULTS: The initial search returned 69 studies out of which 15, including 2732 THAs, met the inclusion criteria. The most frequent indication for THA was dislocated painful hip for which previous non-operative treatment had failed. Complications presented in 10 to 45% of cases. The most frequently reported complication was dislocation (1-20%), followed by component loosening (0.74-20%). Aseptic component loosening was the most frequent cause of revision surgery, followed by dislocation and periprosthetic fracture. Mean implant survival at ten years was 84% (range 81-86%). CONCLUSION: The available literature suggests that although THA is a beneficial procedure in CP patients, it has a higher rate of complications and worse implant survival than the general population.

Preliminary outcomes of the cementless UNITED hip system for primary total hip arthroplasty at a minimum 2-year follow-up.

INTRODUCTION: This study aimed to report the initial results of the cementless UNITED hip system in primary total hip arthroplasty (THA) with a minimum follow-up of 2 years. METHODS: We retrospectively studied a consecutive series of 203 cementless THAs in 180 patients operated between 2015-2017. We included 89 female and 91 male patients with a mean age of 67 (28 to 89) years. The mean follow-up was 40 (29 to 62) months. Clinical outcome scores and radiographs were measured. Survival was calculated defining failure as the need for any further femoral or acetabular revision, irrespective of the reason. RESULTS: No femoral component loosening was detected. One patient had a Vancouver-B1 intraoperative periprosthetic femoral fracture treated with implant retention and cerclage wires. Two acetabular components were revised for aseptic loosening. Three patients suffered an acute infection treated with debridement, antibiotics, and implant retention. The mean Merle d'Aubigné et Postel scores improved from 13 (4 to 16) points preoperatively to 17 (12 to 18) points at the latest follow-up (p < 0.001). At a mean time of 40 months of follow-up, the survival was 99% and 100% for the acetabular and the femoral components, respectively. CONCLUSION: This cementless design showed excellent preliminary outcomes in terms of fixation and patient satisfaction, comparable to that of other well-known similar systems.

Editorial Commentary: Reach Over the Top and Preserve the Hip Labrum.

There is increasing interest in fine tuning of hip arthroscopy to improve the long-term outcomes of femoroacetabular impingement (FAI) surgery. Recently, some advocated for rim trimming and labral refixation without taking down the labrum, using a so-called over-the-top technique. Although some studies have already reported on the outcomes of this procedure, very few have focused on how maintaining an unharmed chondrolabral junction may decrease cartilage wear over time. Preserving labral attachment should be the standard of care in the treatment of FAI, to keep the suction seal working normally.

Hip Joint Preservation Surgery: What Every Orthopaedic Provider Needs to Know.

The understanding of the native hip's mechanics, physiology, and pathology has dramatically improved over the recent 2 decades. This was facilitated by the introduction of open and arthroscopic procedures to the native hip aimed at improving the joint's function and longevity. Associations between abnormal hip mechanics and further development of osteoarthritis are now clear. As the knowledge of hip joint mechanics has improved, other conditions around the hip have become evident, which may lead to pain but not necessarily osteoarthritis. It is important for the orthopaedic surgeon to be up to date on how the hip preservation field has evolved and the steps to consider when a painful hip presents in clinic.

A Repeat Dose of Perioperative Dexamethasone Can Effectively Reduce Pain, Opioid Requirement, Time to Ambulation, and In-Hospital Stay After Total Hip Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: The ideal dose of intravenous glucocorticoids to control pain in total hip arthroplasty (THA) remains unclear. This randomized controlled trial compared postoperative pain and tramadol requirement in patients undergoing unilateral primary THA who received one versus two perioperative doses of dexamethasone. METHODS: Patients consented to undergo blinded, simple randomization to either one (at anesthetic induction [1D-group]: 54 patients) or two (with an additional dose 8 hours after surgery [2D-group]: 61 patients) perioperative doses of 8-mg intravenous dexamethasone. Pain was evaluated with visual analog scale at 8, 16, and 24 hours postoperatively and with tramadol requirement. The secondary outcomes included postoperative nausea and vomiting, time to ambulation, and length of stay. RESULTS: Age (mean, 66 ± 13 years), body mass index (mean, 29 ± 5), gender (60% female), and history of diabetes were similar between groups (P >.05). Pain was higher at 16 (4 [interquartile range {IQR} 3-5] vs 2 [IQR 1-3]; P <.001) and 24 (2.5 [IQR 2-3] vs 1 [IQR 0-1] P <.001) hours postoperatively in the 1D-group patients. 1D-group patients had significantly more tramadol consumption (50 [IQR 50-100] vs 0 [IQR 0-50]; P = .01), as well as postoperative nausea and vomiting (18 [33.3%] vs 5 [8.2%]; P = .001). Fifty-five (90%) patients in the 2D-group and 32 (59%) in the 1D-group ambulated on postoperative day 0 (P = .0002). Fifty-eight (95%) patients in the 2D-group and 37 (68%) in the 1D-group were discharged on postoperative day 1 (P = .0002). CONCLUSION: An additional dose of dexamethasone at 8 hours postoperatively significantly reduced pain, tramadol consumption, time to ambulation, and length of stay after primary THA.

Is There a Role for Preclosure Dilute Betadine Irrigation in the Prevention of Postoperative Infection Following Total Joint Arthroplasty?

BACKGROUND: Conflicting evidence exists surrounding the use of preclosure irrigation solutions in primary total joint arthroplasty (TJA). We aimed to determine the role of dilute betadine lavage in preventing early infection after primary TJA. METHODS: We retrospectively reviewed primary TJAs between 2010 and 2018. Dilute betadine lavage was introduced to our practice in November 2014. We included 3513 total hip arthroplasties, 3932 total knee arthroplasties, and 1033 hip resurfacings (HRs). In group 1 (n = 5588), surgical wounds were irrigated with saline; group 2 used dilute betadine solution (n = 2890). Subanalyses using propensity matching based on known risk factors of infection-age, body mass index, American Society of Anesthesiologists grade, diabetes, and procedure-were completed. RESULTS: There were 48 acute infections in group 1 (0.9%) and 23 in group 2 (0.8%) (P = .762). HR without betadine had the highest acute infection prevalence (P = .028). When groups in the whole cohort were propensity score-matched, group 1 had more acute infections than group 2 (P = .033). The effect of betadine was isolated to HR patients. After excluding HR cases, betadine continued to reduce the acute infection rate when compared with the no betadine group, but this was not statistically significant (0.4% vs 0.8%; P = .101). Likewise, we did not find a significant difference in total hip arthroplasty and total knee arthroplasty patients (P = .796). CONCLUSION: There was a decreased infection rate in the betadine group overall when groups were propensity-matched. Because the reduction in the acute infection rate was clinically significant, we feel this practice is an effective means to prevent infections.

Prolonged social lockdown during COVID-19 pandemic and hip fracture epidemiology.

PURPOSE: To analyse the impact of prolonged mandatory lockdown due to COVID-19 on hip fracture epidemiology. METHODS: Retrospective case-control study of 160 hip fractures operated upon between December 2019 and May 2020. Based on the date of declaration of national lockdown, the cohort was separated into two groups: 'pre-COVID time' (PCT), including 86 patients, and 'COVID time' (CT), consisting of 74 patients. All CT patients tested negative for SARS-CoV-2. Patients were stratified based on demographic characteristics. Outcome measures were 30-day complications, readmissions and mortality. A logistic regression model was run to evaluate factors associated with mortality. RESULTS: Age, female/male ratio, body mass index and American Society of Anaesthesia score were similar between both groups (p > 0.05). CT patients had a higher percentage of Charlson ≥ 5 and Rockwood Frailty Index ≥ 5 scores (p < 0.05) as well as lower UCLA and Instrumental Activities of Daily Living scores (p < 0.05). This translated into a higher hemiarthroplasty/total hip arthroplasty ratio during CT (p = 0.04). Thromboembolic disease was higher during CT (p = 0.02). Readmissions (all negative for SARS-CoV-2) were similar between both groups (p = 0.34). Eight (10.8%) casualties were detected in the CT group, whereas no deaths were seen in the control group. Logistic regression showed that frailer (p = 0.006, OR 10.46, 95%CI 8.95-16.1), less active (p = 0.018, OR 2.45, 95%CI 1.45-2.72) and those with a thromboembolic event (p = 0.005, OR 30, 95%CI 11-42) had a higher risk of mortality. CONCLUSION: Despite testing negative for SARS-CoV-2, CT patients were less active and frailer than PCT patients, depicting an epidemiological shift that was associated with higher mortality rate.

Re-admissions treble the risk of late mortality after primary total hip arthroplasty.

BACKGROUND: Following a total hip arthroplasty (THA), early hospital re-admission rates of 3-11% are considered as 'acceptable' in terms of medical care cost policies. Surprisingly, the impact of re-admissions on mortality has not been priorly portrayed. Therefore, we sought to determine the mortality rate after 90-day re-admissions following a THA in a series of patients from a captive medical care program. PATIENTS AND METHODS: We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated upon between 2010 and 2014 whose medical care was the one offered by our institution. We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazards model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with early and late mortality. RESULTS: We found 37 (4.53%) re-admissions at a median time of 40.44 days (IQR 17.46-60.69). Factors associated with re-admission were hospital stay (p = 0.00); surgical time (p = 0.01); chronic renal insufficiency (p = 0.03); ASA class 4 (p = 0.00); morbid obesity (p = 0.006); diabetes (p = 0.04) and a high Charlson index (p = 0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5 days (IQR 297.58-1170.65). One-third (11/37) of the re-admitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day re-admissions remained associated with mortality with an adjusted HR of 3.14 (CI95% 1.05-9.36, p = 0.04). CONCLUSIONS: Unplanned re-admissions were an independent risk factor for future mortality, increasing three times the risk of mortality.

What Happens to the Articular Surface After Curettage for Epiphyseal Chondroblastoma? A Report on Functional Results, Arthritis, and Arthroplasty.

BACKGROUND: Chondroblastoma is an uncommon, benign, but locally aggressive bone tumor that occurs in the apophyses or epiphyses of long bones, primarily in young patients. Although some are treated with large resections, aggressive curettage and bone grafting are more commonly performed to preserve the involved joint. Such intralesional resection may result in damage to the growth plate and articular cartilage, which can result in painful arthritis. Prior studies have focused primarily on oncologic outcomes rather than long-term joint status and functional outcomes. QUESTIONS/PURPOSES: (1) What local complications can be expected after aggressive intralesional curettage of epiphyseal chondroblastoma? (2) What is the joint survival of a joint treated in this way for chondroblastoma? (3) What additional procedures are used in treating symptomatic joint osteoarthritis after treatment of the chondroblastoma? (4) What are the functional outcomes in this group of patients? METHODS: A retrospective study of our prospectively collected database between 1975 and 2013 was done. We found 64 patients with a diagnosis of chondroblastoma of bone. After applying our selection criteria, 53 patients were involved in this study. We excluded seven patients with tumors initially treated with en bloc resection (five located in the extremities and two in the axial skeleton) and two patients with apophyseal tumors. One patient who underwent nonsurgical treatment and one patient lost to followup were also excluded. The mean age was 18 years (range, 11-39 years); the minimum followup was 2 years with a mean followup 77 months (range, 24-213 months). We analyzed all patients with a diagnosis of epiphyseal chondroblastoma of the limb treated with aggressive curettage and joint preservation surgery. During the period in question, our general indications for curettage were patients with active, painful tumors and those with more aggressive ones that remained intracompartmental, whereas initial wide en bloc resection was indicated in patients who had tumors with an extracompartmental extension breaching the adjacent joint cartilage and massive articular destruction. The tumor location was the distal femur in 14 patients, proximal tibia in 11, proximal humerus in 10, proximal femur in eight, the talus in seven, and elsewhere in the lower extremity in three. Local complications including joint degeneration and tumor recurrence were evaluated. Based on radiographic analysis, secondary osteoarthritis was classified by using the Kellgren-Lawrence grading system from Grade 0 to Grade IV. Patients who underwent joint replacement resulting from advanced symptomatic osteoarthritis were considered to have had joint failure for purposes of survivorship analysis, which was estimated using the Kaplan-Meier method. Functional results were evaluated with the Musculoskeletal Tumor Society functional score by the treating surgeon, who transcribed the results on the digital records every 6 months of followup. RESULTS: Twenty-two patients (42%) developed 26 local complications. The most common local complication was osteoarthritis in 20 patients (77% [20 of 26 complications]); tumor recurrence was observed in four patients; an intraarticular fracture and superficial infection treated with surgical débridement and antibiotics developed in one patient each. Joint survival was 90% at 5 years (95% confidence interval [CI], 76%-100%) and 74% at 10 years (95% CI, 48%-100%). Proximal femoral tumor location was associated with lower survivorship of the joint than other locations showing a 5-year survival rate of 44% (95% CI, 0%-88%; p = 0.000). Of the 20 patients with osteoarthritis, four were symptomatic enough to undergo joint replacement, all of which were for tumors in the proximal femur. The mean Musculoskeletal Tumor Society functional score was 28 of 30 points (93%). CONCLUSIONS: Osteoarthritis was a frequent complication of aggressive curettage of epiphyseal chondroblastoma, and tumors located in the proximal femur appeared to be at particular risk of secondary osteoarthritis and prosthetic replacement. Because chondroblastoma is a tumor that disproportionately affects younger patients, the patient and surgeon should be aware that arthroplasty at a young age is a potential outcome for treatment of proximal femoral chondroblastomas. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Massive Osteochondral Lesion of the Talus in a Skeletally Immature Patient Associated With a Tarsal Coalition and Valgus Hindfoot.

Rarely, osteochondral lesions of the talus occur without a history of trauma. Accurate interpretation of the mechanical load distributions onto the ankle leading to potential atraumatic cartilage damage must always be studied. The published data on the optimal treatment of talar osteochondral lesions in skeletally immature patients are scarce, especially when the lesions are associated with hindfoot malalignment. We describe the case of a pediatric female with an atraumatic osteochondral lesion of the talus associated with a talocalcaneal coalition and a valgus hindfoot, which we consider the first case to be reported. She presented with prolonged bilateral ankle pain and catching during gait of approximately 2 years' duration with a restricted range of motion, with the pain more excruciating in the right ankle. Radiographs revealed a large osteochondral lesion located at the lateral talar dome. The patient underwent partial osteochondral allograft transplantation, together with hindfoot realignment and coalition resection with a fat graft interposition. At the 2-year follow-up examination, the patient was free of pain in her right foot and ankle, with no signs of radiologic failure.

Medium-term outcomes of conventional versus short uncemented femoral stems for primary total hip arthroplasty in patients younger than 55 years.

BACKGROUND: Short stems are designed with a bone preservation philosophy in mind. This study aims to compare the outcomes/complications and survival of a collarless fully hydroxyapatite (HA)-coated conventional tapered stem and a HA-coated partial neck-retaining uncemented short stem in patients ⩽55 years old at medium-term follow-up. METHODS: We retrospectively studied 247 uncemented THAs operated between 2010 and 2014, comparing 146 patients treated with the fully HA-coated collarless stem (Group A) with 101 patients treated with a partial neck preserving, HA-coated short stem (Group B). 87 and 62 males were in groups A and B, respectively (p = 0.11). The mean age of the series was 46 years (17-55) (p =0.16). The mean follow-up of groups A and B were 9.9 (7-12) years and 9.7 (7-12) years, respectively (p =0.21). RESULTS: Mean Harris Hip Score improved from 55 to 92 in group A (p <0.001) and from 54 to 95 in group B (p <0.001), without differences between groups. Mean femoral neck length preservation in groups A and B was 13.6 (0-28) mm and 26 (11-38) mm, respectively (p =0.001). 13 (8.9%) and 1 (1%) patients in groups A and B presented postoperative complications, respectively (p =0.008). The conventional stem group had more aseptic loosening (Group A 3.4% vs. Group B 0%, p =0.06) along with more Symptomatic radiolucent lines (Group A 3.4% vs. Group B 0%, p =0.06). CONCLUSIONS: Both conventional and short stems showed excellent implant survival rates and functional outcomes at a mean follow-up of 9.8 years. However, complications and radiolucent lines were more frequent with a collarless conventional-length stem. Bone preservation of the femoral neck and diaphysis may be preferred in active young patients.

Prediction of 3-Dimensional Coverage Surface Area of the Femoral Head in Hip Dysplasia Through Conventional Computed Tomography.

Background: Assessment of 3-dimensional (3D) femoral head coverage is critical in evaluating, preoperative planning, and treating hip dysplasia. Purpose: To (1) propose a mathematical model to establish 3D femoral head coverage using conventional computed tomography (CT), (2) determine the correlation of 2D parameters with 3D coverage, and (3) characterize the patterns of dysplasia based on 3D morphology. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We identified 30 patients (n = hips) with symptomatic dysplasia and 30 patients (n = hips) without dysplasia. Patients with dysplastic hips were matched with regard to sex, age, and body mass index to those with nondysplastic hips. Preoperative CTs were analyzed using 3D software, and 3D femoral head surface area coverage (FHSAC; in %) was assessed in 4 quadrant zones: anteromedial, anterolateral, posteromedial, and posterolateral. To assess lateral coverage of the femoral head, we introduced the anterolateral femoral head coverage angle (ALFC) and the posterolateral femoral head coverage angle (PLFC). Results: Reduced femoral head coverage was more pronounced in dysplastic versus nondysplastic hips in the anterolateral quadrant (18% vs 40.7%, respectively) and posterolateral quadrant (35.8% vs 56.9%, respectively) (P < .0001 for both). Dysplastic hips had smaller ALFC and PLFC (18.4° vs 38.7°; P < .0001; 47.2° vs 72.3°; P = .0002). Anterolateral and posterolateral FHSAC were strongly correlated with the ALFC (r = 0.88; P < .0001) and the PLFC (r = 0.82; P < .0001) along with the lateral center-edge angle (anterolateral, r = 0.75; P < .0001; posterolateral, r = 0.73; P < .0001). Prediction models established for FHSAC had strong agreement with explanatory CT variables (anterolateral: r = 0.91; P < .0001; posterolateral: r = 0.90; P < .0001). The cutoff values for anterolateral and posterolateral FHSAC were 25% and 41%, respectively. In dysplastic hips, global deficiency was most common (15/30 hips), 9 hips showed an anterolateral deficiency, and 4 hips had a posterolateral deficiency pattern. Conclusion: The ALFC and The PLFC were strongly correlated with 3D lateral FHSAC and were able to predict 3D coverage accurately.

Cerclage wire or positional cortical screw for the treatment of intraoperative calcar fractures during primary total hip arthroplasty? A biomechanical study.

BACKGROUND: During primary total hip arthroplasty, intra-operative calcar fractures have been historically treated with cerclage wires. However, interfragmentary screw fixation technique can possibly achieve the same results with technical advantages. The aim of this biomechanical study was to assess stability of calcar fractures fixed using interfragmentary screw technique compared to a traditional cerclage system specifically in context of total hip arthroplasty. METHODS: Thirty-two periprosthetic fractures were reduced using either a single cerclage cable or an intracortical positional screw perpendicular to the fracture line. Axial and torsional load testing was terminated after experimental model failure. FINDINGS: No significant difference was obtained for all output parameters when comparing cerclage wires versus interfragmentary screw fixation respectively. Load at failure: 8043 ± 712 N vs 7425 ± 854 N (p = 0.115). Load at calcar fracture propagation: 6240 ± 2207 N versus 6220 ± 966 N (p = 0.668). Maximum stiffness before failure: 617 ± 115 N/mm vs 839 ± 175 N/mm (p = 0.100) and stiffness at calcar fracture propagation reached 771 ± 153 Nmm vs 886 ± 129 N/mm (p = 0.197). Torque to failure levels obtained were 59.4 ± 7.1 N*m vs 60.9 ± 12.0 N*m (p = 0.908). Torque to calcar fracture propagation, 51.6 ± 6.1 N*m vs 48.5 ± 9.8 N*m (p = 0.298). Torsional stiffness at failure, 0.38 ± 0.03 N*m\deg. vs 0.43 ± 0.13 N*m\deg. (p = 0.465). Torsional stiffness at calcar fracture propagation were 0.37 ± 0.03 N*m\deg. vs 0.45 ± 0.17 N*m\deg. (p = 0.462). INTERPRETATION: The strength of fixation and stability of the implant were similar for both techniques. In the synthetic bone model tested, using an interfragmentary screw conveyed similar stability to the constructs in the management of an intra-operative medial calcar fractures. Thus, potentially giving surgeons an alternative option for intraoperative fracture fixation during primary total hip arthroplasty.

Acetabular Sector Angles in Asymptomatic and Dysplastic Hips: Defining Dysplasia and Thresholds to Guide Management.

BACKGROUND: Radiographic evaluation plays an important role in detecting and grading hip dysplasia. Acetabular sector angles (ASAs) measure the degree of femoral head coverage provided by the acetabulum on computed tomographic (CT) scans. In this study, we aimed to determine ASA values at different axial levels in a control cohort with asymptomatic, high-functioning hips without underlying hip pathology and a study group with symptomatic, dysplastic hips that underwent periacetabular osteotomy (PAO), thereby defining the ASA thresholds for hip dysplasia. METHODS: This was a cross-sectional study evaluating a control group of 51 patients (102 hips) and a study group of 66 patients (72 hips). The control group was high-functioning and asymptomatic, with an Oxford Hip Score of >43, did not have osteoarthritis (Tönnis grade ≤1), underwent a pelvic CT scan, had a mean age (and standard deviation) of 52.1 ± 5.5 years, and was 52.9% female. The study group had symptomatic hip dysplasia treated with PAO, had a mean age of 29.5 ± 7.3 years, and 83.3% was female. Anterior ASA (AASA) and posterior ASA (PASA) were measured at 3 axial CT levels to determine equatorial, intermediate, and proximal ASA. The thresholds for dysplasia were determined using receiver operating characteristic (ROC) curve analysis, including the area under the curve (AUC). RESULTS: Patients with dysplasia had significantly smaller ASAs compared with the control group; the differences were most pronounced for proximal AASAs and proximal and intermediate PASAs. The control group had a mean proximal PASA of 162° ± 17°, yielding a threshold for dysplasia of 137° (AUC, 0.908). The mean intermediate PASA for the control group was 117° ± 11°, yielding a threshold of 107° (AUC, 0.904). The threshold for anterior dysplasia was 133° for proximal AASA (AUC, 0.859) and 57° for equatorial AASA (AUC, 0.868). The threshold for posterior dysplasia was 102° for intermediate PASA (AUC, 0.933). CONCLUSIONS: Measurement of ASA is a reliable tool to identify focal acetabular deficiency with high accuracy, aiding diagnosis and management. A proximal PASA of <137° or an intermediate PASA of <107° should alert clinicians to the presence of dysplasia. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Acetabular coverage analysis of the proximal femoral head accurately characterizes dysplastic acetabular morphology.

This study aimed to (1) measure acetabular sector angle (ASA) from proximal to distal positions along the axial femoral head axis, (2) identify acetabular deficiency patterns, and (3) correlate ASA at different axial positions with other radiological measurements in acetabular dysplasia. We identified 30 hips with dysplasia (lateral center edge angle [LCEA] <20°) and 30 hips without dysplasia (LCEA >25°) from a retrospective cohort. Anterior and posterior ASA (AASA, PASA) were measured in the axial computed tomography plane through the femoral head center (equatorial) and two axial positions above the equatorial line (intermediate and proximal). Deficiency patterns were identified using ASA cut-off values determined from receiver operating characteristic curves. Pearson's coefficients were used for correlations. Compared to non-dysplastic hips, AASA in dysplastic hips was significantly smaller in all levels: equatorial (46.1 ± 7.3 vs. 54.9 ± 8.5,° p < 0.001), intermediate (62.1 ± 11.2 vs. 69.0 ± 10.6,° p = 0.02), and proximal (102.9 ± 14.2 vs. 128.3 ± 23.0,° p < 0.001). According to proximal ASA (Pro-ASA) cut-off values in dysplastic hips, global deficiency was most prevalent (19/30, 63.3%), followed by anterior (6/30, 20%) and posterior (3/30, 10%) deficiency. There were strong correlations between acetabular anteversion and Eq-AASA (r = -0.74, p < 0.001) and LCEA and pro-PASA (r = 0.82, p < 0.001). Clinical significance: Acetabular sector angle provides insight into acetabular morphology and patterns of deficiency, providing essential information for precise acetabular reorientation.

Anterior Center-Edge Angle Is Less Reliable Than Anterior Wall Index to Predict Anterior Coverage of the Femoral Head.

BACKGROUND: No consensus is available regarding which radiographic measurement most accurately correlates with anterior coverage of the femoral head. PURPOSE: (1) To determine the correlation between 2 measurements of anterior wall coverage: total anterior coverage (TAC) calculated from radiographs and equatorial anterior acetabular sector angle (eAASA) calculated from computed tomography (CT) scans; (2) to define the correlation between anterior center-edge angle (ACEA) and anterior wall index (AWI) with TAC and eAASA; and (3) to investigate what other radiographic metrics may help predict anterior coverage. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: The authors retrospectively reviewed 77 hips (48 patients) for which radiographs and CT scans were obtained for reasons other than hip-related pain. Mean age of the population was 62 ± 22 years; 48 (62%) hips were from female patients. Two observers measured lateral center-edge angle (LCEA), AWI, Tönnis angle, ACEA, CT-based pelvic tilt, and CT-based acetabular version, with all Bland-Altman plots within 95% agreement. Correlation between intermethod measurements was estimated with a Pearson coefficient. Linear regression was used to test the ability of baseline radiographic measurements to predict both TAC and eAASA. RESULTS: Pearson coefficients were r = 0.164 (ACEA vs TAC; P = .155), r = 0.170 (ACEA vs eAASA; P = .140), r = 0.58 (AWI vs TAC; P = .0001), and r = 0.693 (AWI vs eAASA; P < .0001). Multiple linear regression model 1 showed that AWI (ß = 17.8; 95% CI, 5.7 to 29.9; P = .004), CT acetabular version (ß = -0.45; 95% CI, -0.71 to -0.22; P = .001), and LCEA (ß = 0.33; 95% CI, 0.19 to 0.47; P = .001) were useful to predict TAC. Multiple linear regression model 2 revealed that AWI (ß = 25; 95% CI, 15.67 to 34.4; P = .001), CT acetabular version (ß = -0.48; 95% CI, -0.67 to -0.29; P = .001), CT pelvic tilt (ß = 0.26; 95% CI, 0.12 to 0.4; P = .001), and LCEA (ß = 0.21; 95% CI, 0.1 to 0.3; P = .001) accurately predicted eAASA. Model-based estimates and 95% CIs using 2000 bootstrap samples from the original data were 6.16 to 28.6 for AWI in model 1 and 15.1 to 34.26 for AWI in model 2. CONCLUSION: There was a moderate to strong correlation between AWI and both TAC and eAASA, whereas ACEA correlated weakly with the former measurements, thus not being useful to quantify anterior acetabular coverage. Other variables such as LCEA, acetabular version, and pelvic tilt may also help predict anterior coverage in asymptomatic hips.

Successful hip revision surgery following refracture of a modern femoral stem using a cortical window osteotomy technique: A case report and review of literature.

BACKGROUND: The ExeterTM Universal cemented femoral component is widely used for total hip replacement surgery. Although there have been few reports of femoral component fracture, removal of a broken femoral stem can be a challenging procedure. CASE SUMMARY: A 54-year-old man with a Dorr A femur sustained a refracture of a primary ExeterTM stem, two years after receiving a revision using a cement-within-cement technique (CWC) through an extended trochanteric osteotomy (ETO). The technical problems related to the CWC technique and the ETO played a major role in the stem fatigue refracture. We performed revision surgery and removed the distal cement using a cortical femoral window technique, followed by re-implantation with an uncemented, modular, distally-fixed uncemented stem. The patient experienced an uneventful postoperative recovery. CONCLUSION: Re-fracture of a modern femoral ExeterTM stem is a rare event, but technical complications related to revision surgery can lead to this outcome. The cortical window osteotomy technique can facilitate the removal of a broken stem and cement, allowing for prosthetic re-implantation under direct vision and avoiding ETO-related complications.