Novel radiologic indices for stem type decision in total hip arthroplasty in patients with metaphyseo-diaphyseal mismatched Dorr A proximal femur.

BACKGROUND: In metaphyseo-diaphyseal (M-D) mismatched Dorr A femurs, it is difficult to achieve proper fixation with a type 1 stem. Proper interpretation of the geometry of the femur is integral at the preoperative stage in an M-D mismatched femur, but there has been a scarcity of studies on the radiologic indices. Therefore, we analyze the previous radiologic indices and suggest the novel ones for M-D mismatched femurs. METHODS: Our study was a retrospective review of preoperative radiographs of patients who underwent total hip arthroplasty with the smallest type 1 stem or with type 3 C stem at a single institution from July 2014 to March 2022. A Type 3 C stem was used when the smallest type 1 stem failed to achieve metaphyseal fixation. One hundred twenty-six patients were categorized into two main groups. Canal-flare index, canal-calcar ratio, modified morphological cortical index, and two novel indices (lesser trochanter-to-distal ratio-α and -ß [LDR-α and -ß]) were assessed on preoperative pelvic radiographs. RESULTS: Multivariate and ROC analysis demonstrated that high LDR-ß (Exp[B]: 485.51, CI: 36.67-6427.97, p < 0.001) was associated with a more mismatched tendency group and had clinically acceptable discriminatory power (AUC: 0.765, CI: 0.675-0.855, p < 0.001) between the two cohorts. CONCLUSION: Correct assessment of preoperative femoral morphology would be fundamental in the selection of a suitable stem. The ratio based on 3 cm below the lesser trochanter of the femur seemed crucial. We recommend evaluating the newly described radiological index preoperatively in M-D mismatched Dorr A femur for planning precisely and selecting a proper stem.

Computed Tomography Evaluation of Alumina Ceramic-on-Ceramic Total Hip Arthroplasty With More Than 20 years of Follow-Up: Is a Follow-Up Computed Tomography Scan Necessary?

BACKGROUND: Ceramic-on-ceramic (CoC) bearings have been increasingly used in total hip arthroplasty (THA) because of their superior wear resistance and biocompatibility. However, there is a scarcity of reports on the computed tomography (CT) evaluation of CoC bearings with more than 10 years. The aim of this study was to evaluate the long-term CT results of THA using CoC bearings for more than 20 years of follow-up. We hypothesized that there would be no wear, osteolysis, or ceramic fracture. METHODS: Between November 1997 and June 2003, 956 hips underwent THA using alumina-on-alumina bearings at a tertiary referral hospital. Among them, 107 hips were assessed, all of which underwent a CT examination more than 20 years after the index surgery. The mean age at the time of surgery was 41 years, and a CT scan was performed at an average of 22.0 years postoperatively (range, 20.0 to 25.1). The CT scans were thoroughly assessed for osteolysis, stem notching, and ceramic component fracture. RESULTS: No loosening was observed in the acetabular cup or femoral stem. Stem notching was observed in 3 hips (2.8%). In the CT scan taken after a minimum of 20 years of follow-up, 1 case (0.9%) of osteolysis around the cup and 2 cases (1.9%) of osteolysis around the femoral stem were noted. Suspected chip fractures of the ceramic insert were discovered in 4 cases (3.7%). Despite these findings, the patients remained asymptomatic, and no subsequent surgical intervention was needed after close follow-up. CONCLUSIONS: Routine CT examinations for patients who underwent THA using CoC bearings over 20 years ago revealed unexpected findings, such as osteolysis and suspected chip fractures of the ceramic liner. However, routine CT scans may not be universally necessary. The CT evaluation in this cohort should be selectively performed for patients who have relevant clinical symptoms. LEVEL OF EVIDENCE: Level III, Therapeutic study.

Outcome and complication rate of total hip arthroplasty in patients younger than twenty years: which bearing surface should be used?

PURPOSE: Total hip arthroplasty (THA) in younger patients remains controversial due to concerns regarding long-term implant survival and potential complications. This study aimed to evaluate long-term clinical outcomes, complications, differences in complication and revision rates by bearing surfaces, and Kaplan-Meier survival curves for THA in patients under 20 years old. METHODS: A retrospective review was conducted for 65 patients (78 hips) who underwent THA between 1991 and 2018. Their mean age was 18.9 years. Their clinical outcomes were assessed using the Harris Hip Score (HHS). Radiological outcomes were evaluated based on the presence of loosening, osteolysis, and heterotopic ossification. Complications such as dislocation, periprosthetic fractures, and infections were assessed. The mean follow-up period was 13.2 years (range, 5.0-31.2 years). RESULTS: The mean HHS improved from 44.6 to 90.1. There were two cases of dislocation. However, no periprosthetic fracture, deep infection, or ceramic component fracture was noted. There were 19 revisions of implants. Eighteen of 19 hips were operated with hard-on-soft bearings in the index surgery (p < 0.01). The 23-year survivorship was 97.8% for THA using ceramic-on-ceramic bearings, while the 31-year survivorship was 36.7% using hard-on-soft bearings. CONCLUSION: THA in patients under 20 years old yielded promising clinical and radiological outcomes, although polyethylene-bearing-related concerns persisted. Previously operated patients with hard-on-soft bearing should be meticulously examined during the follow-up. As ceramic-on-ceramic bearing showed excellent survivorship in this particular cohort, we recommend the use of this articulation as the bearing of choice.

Ipsilateral pubic ramus fracture during total hip arthroplasty is not rare: does it matter?

INTRODUCTION: Periprosthetic fractures in total hip arthroplasty (THA) have been well described and studied. However, there is a lack of reports on ipsilateral pubic ramus fractures during THA due to the rare occurrence of such fractures and ambiguity of symptoms. With the use of postoperative computed tomography (CT) examinations, we have identified that asymptomatic ipsilateral pubic ramus fractures occur frequently during THA. This study aims to evaluate the incidence, location, clinical outcomes, and risk factors of ipsilateral pubic ramus fractures during THA. METHODS: From May 2022 to March 2023, a single surgeon performed 203 THAs in 183 patients at a single institution. All patients underwent postoperative CT scans three days after THA. The patients with ipsilateral pubic ramus fractures were followed up for a minimum of six months. Basic demographics, osteoporosis, general conditions of the operations, and outcomes of THA were investigated in all patients. RESULTS: Twenty-two cases (10.8%) of ipsilateral pubic ramus fractures were identified on postoperative CT scans. All fractures were located near the origin of the superior or inferior pubic ramus. Five fractures were detected on simple postoperative radiographs. The fractures did not cause any further complications at a minimum of six-month postoperative follow-up. Univariate and multivariate analyses did not identify any risk factors associated with these fractures. CONCLUSIONS: Although the incidence of ipsilateral pubic ramus fractures during THA is high, treatment is not required as they do not cause any significant clinical symptoms or affect the prognosis of THA. However, the possibility of occurrence of these fractures must be explained to the patients before surgery.

Minimal pre-operative leg length discrepancy as a risk factor of post-operative leg length discrepancy after total hip arthroplasty: a retrospective study of patients with non-traumatic osteonecrosis of the femoral head.

BACKGROUND: Leg length discrepancy (LLD) is one of the troublesome complications of total hip arthroplasty (THA). Previously, several risk factors have been suggested, but they were subjected to their inherent limitations. By controlling confounding variables, we hypothesized that known risk factors be re-evaluated and novel ones be discovered. This study aimed to analyze the independent risk factors for LLD after primary THA in patients with non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: We retrospectively reviewed patients with non-traumatic ONFH who underwent unilateral THA between 2014 and 2021. All patients were operated by one senior surgeon using a single implant. Demographic data, surgical parameters, and radiological findings (pre-operative LLD, Dorr classification, and femoral neck resection) were analyzed to identify the risk factors of ≥ 5 mm post-operative LLD based on radiological measurement and to calculate odds ratios by logistic regression analysis. Post hoc power analysis demonstrated that the number of analyzed patients was sufficient with 80% power. RESULTS: One hundred and eighty-six patients were analyzed, including 96 females, with a mean age of 58.8 years at the time of initial THA. The average post-operative LLD was 1.2 ± 2.9 mm in the control group and 9.7 ± 3.2 mm in the LLD group, respectively. The LLD group tended to have minimal pre-operative LLD than the control group (-3.2 ± 5.1 mm vs. -7.9 ± 5.8 mm p = 2.38 × 10- 8). No significant difference was found between the groups in age, gender, body mass index, femoral cortical index, and implant size. CONCLUSION: Mild pre-operative LLD is associated with an increased risk of post-operative LLD after primary THA in patients with ONFH. Thus, surgeons should recognize pre-operative LLD to achieve an optimal outcome and must inform patients about the risk of developing LLD.

Assessment of patient-reported outcomes (PROs): treatment satisfaction, medication adherence, and quality of life (QoL) and the associated factors in postmenopausal osteoporosis (PMO) patients in Korea.

Patient-reported outcomes (PROs) provide practical guides for treatment; however, studies that have evaluated PROs of women in Korea with postmenopausal osteoporosis (PMO) are lacking. This cross-sectional, multi-center (29 nationwide hospitals) study, performed from March 2013 to July 2014, aimed to assess PROs related to treatment satisfaction, medication adherence, and quality of life (QoL) in Korean PMO women using osteoporosis medication for prevention/treatment. Patient demographics, clinical characteristics, treatment patterns, PROs, and experience using medication were collected. The 14-item Treatment Satisfaction Questionnaire for Medication (TSQM) (score-range, 0-100; domains: effectiveness, side effects, convenience, global satisfaction), Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS) (score-range, 0-8), and EuroQol-5 dimensions questionnaire (index score range, - 0.22 to 1.0; EuroQol visual analog scale score range, 0-100) were used. To investigate factors associated with PROs, linear (treatment satisfaction/QoL) or logistic (medication adherence) regression analyses were conducted. A total of 1804 patients (age, 62 years) were investigated; 60.1% used bisphosphonate, with the majority (67.2%) using weekly medication, 27.8% used daily hormone replacement therapy, and 12.1% used daily selective estrogen receptor modulator. Several patients reported gastrointestinal (GI) events (31.6%) and dental visits due to problems (24.1%) while using medication. Factors associated with the highest OS-MMAS domain scores were convenience and global satisfaction. GI events were associated with non-adherence. TSQM scores for effectiveness, side effects, and GI risk factors were significantly associated with QoL. Our study elaborately assessed the factors associated with PROs of Korean PMO women. Based on our findings, appropriate treatment-related adjustments such as frequency/choice of medications and GI risk management may improve PROs.

Periprosthetic femoral fracture as cause of early revision after short stem hip arthroplasty-a multicentric analysis.

BACKGROUND: The objective of this study was to analyze the prevalence and causes of early re-operation after hip replacement surgery using short bone-preserving stems in a large multicentre series. Specifically, we evaluated the clinical features of periprosthetic fractures occurring around short stems. METHODS: A total of 897 patients (1089 hips) who underwent primary total hip arthroplasty or bipolar hemiarthroplasty from January 2011 to February 2015 using short bone-preserving femoral stems were recruited. Mean patient age was 57.4 years (range, 18-97 years), with a male ratio of 49.7% (541/1089). Re-operation for any reason within two years was used as an endpoint. The incidence and clinical characteristics of the periprosthetic femoral fractures were also recorded. Mean follow-up period was 5.1 years (range, 2-7.9 years). RESULTS: Early re-operation for any reason was identified in 16 (1.5%) of 1089 hips. The main reason for re-operation was periprosthetic femoral fracture, which accounted for eight (50%) of the 16 re-operations. The overall incidence of periprosthetic femoral fracture at two years was 1.1% (12/1089). According to the Vancouver classification, two fractures were AG type and the other ten were B1 type. Advanced age, higher American Society of Anesthesiologist grade, femur morphology of Dorr type C, and the use of a calcar-loading stem increased the risk for periprosthetic femoral fracture. CONCLUSION: Periprosthetic femoral fracture was the major reason for re-operation after hip replacement surgery using short bone-preserving stems accounting for 50% (8/16) of re-operations two years post-operatively, but did not seem to deteriorate survivorship of implanted prostheses.

Venous Thromboembolism Following Hip and Knee Replacement Arthroplasty in Korea: A Nationwide Study Based on Claims Registry.

The aim of this study was to examine the incidence and trends of clinically relevant venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) after hip and knee replacement arthroplasty (HKRA) in Korea. Between January 1 and December 31, 2010, 22,127 hip replacement arthroplasty (HRA) patients and 52,882 knee replacement arthroplasty (KRA) patients were enrolled in the analysis using the administrative claims database of the Health Insurance Review and Assessment Service (HIRA). All available parameters including procedure history and clinically relevant VTE during the 90 days after HKRA were identified based on diagnostic and electronic data interchange (EDI) codes. The overall incidence of VTE, DVT, and PE during the 90 days was 3.9% (n=853), 2.7% (n=597), and 1.5% (n=327) after HRA, while the incidence was 3.8% (n=1,990), 3.2% (n=1,699), and 0.7% (n=355) after KRA. The incidence of VTE after HKRA was significantly higher in patients who had previous VTE history (odds ratio [OR], 10.8 after HRA, OR, 8.5 after KRA), chronic heart failure (2.1, 1.3), arrhythmia (1.8, 1.7), and atrial fibrillation (3.4, 2.1) than in patients who did not. The VTE incidence in patients with chemoprophylaxis was higher than that in patients without chemoprophylaxis. The incidence of VTEs revealed in this retrospective review was not low compared with the results of the studies targeting other Asian or Caucasian populations. It may warrant routine prevention including employment of chemoprophylaxis. However, the limitation of the reviewed data mandates large scale prospective investigation to affirm this observation.

Bearing Change to Metal-On-Polyethylene for Ceramic Bearing Fracture in Total Hip Arthroplasty; Does It Work?

We evaluated the short-term to midterm results of reoperation with bearing change to metal-on-polyethylene (MoP) after ceramic bearing fracture in ceramic-on-ceramic total hip arthroplasty. Nine third-generation ceramic bearing fractures (6 heads and 3 liners) were treated with bearing change to MoP. Mean age at reoperation was 52.7 years. Mean follow-up was 4.3 years. During follow-up, 2 of 3 liner-fractured hips and 1 of 6 head-fractured hips showed radiologic signs of metallosis and elevated serum chromium levels. Re-reoperation with bearing rechange to a ceramic head was performed for the hips with metallosis. One liner-fractured hip had periprosthetic joint infection. Dislocation occurred in 3 hips. From our experience, bearing change to MoP is not a recommended treatment option for ceramic bearing fracture in total hip arthroplasty.

Alumina-alumina total hip arthroplasty for the sequelae of Legg-Calve-Perthes disease: A comparative study with adult-onset osteonecrosis.

BACKGROUND: Total hip arthroplasty (THA) for sequelae of Legg-Calve-Perthes disease (LCPD) involves specific concerns for deformity, leg length discrepancy (LLD), and relatively young age. Excellent long-term outcome has been proven after Alumina-Alumina (Al-Al) THA for relatively young patients, however, there was no study for Al-Al THA for LCPD sequelae. The aim of this study is to evaluate the results of Al-Al THA for LCPD sequelae and to compare the results with those for adult-onset ONFH, in which THA is necessitated in relatively young age and excellent long term outcome has been proven after Al-Al THA. METHODS: Between 1997 and 2007, 41 Al-Al THA were performed in 37 patients with LCPD sequelae and followed-up for mean 10.4 years. Mean age at THA was 43.6 years. Using the propensity score matching, 41 THAs in 37 patients were identified from 339 hips in 256 patients with ONFH. The medical record and radiographic data was retrospectively reviewed. RESULTS: During follow-up, no revision was performed in both group. Harris Hip Score increased from 66.7 ± 17.4 points to 96.8 ± 6.8 points in LCPD group and from 47.9 ± 18.4 to 96.6 ± 4.6 in ONFH group. LLD decreased significantly from 2.0 ± 1.2 cm to 0.2 ± 0.9 cm in LCPD group and from 0.5 cm to 0.1 cm in ONFH group. Postoperative LLD showed no difference in both groups. As for complication, rate of intraoperative femoral fracture was significantly higher in LCPD group than in ONFH group. Other postoperative complication showed no difference. CONCLUSIONS: Despite the higher rate of intraoperative femoral crack, outcomes of Al-Al THA for LCPD were comparable to those for ONFH. Similar to ONFH, Al-Al THA may be a reliable treatment option for LCPD.

Total hip arthroplasty performed in patients with residual poliomyelitis: does it work?

BACKGROUND: Patients with residual poliomyelitis can have advanced degenerative arthritis of the hip in the paralytic limb or the nonparalytic contralateral limb. Although THA is a treatment option for some of these patients, there are few studies regarding THA in this patient population. QUESTIONS/PURPOSES: We therefore reviewed a group of patients with residual poliomyelitis who underwent cementless THA on either their paralytic limb or nonparalytic limb to assess (1) Harris hip scores, (2) radiographic results, including implant loosening, (3) complications, including dislocation, and (4) limb length discrepancy after recovery from surgery. METHODS: From January 2000 to December 2009, 10 patients with residual poliomyelitis (10 hips, four paralytic limbs and six nonparalytic contralateral limbs) underwent THA using cementless prostheses. Harris hip scores, complications, and leg length discrepancy were determined by chart review, and confirmed by questionnaire and examination; radiographs were reviewed by two observers for this study. Followup was available for all 10 patients at a minimum of 3 years (median, 7 years; range, 3.4-13 years). Surgery was done at the same side of the paralytic limb in four hips and contralateral to the paralytic limb in six. RESULTS: All patients had pain relief and improvement in function; the Harris hip score improved from mean of 68 preoperatively to 92 at last followup (p = 0.043). However, only three patients had complete pain relief. One hip dislocated, which was treated successfully with closed reduction and a hip spica cast for 2 months. There was no loosening or osteolysis in this series. Leg length discrepancy improved after the index operation, but only in the THAs performed in the paralytic limbs. CONCLUSIONS: Cementless THA may be suitable for painful hips in adult patients with residual poliomyelitis. Nonetheless, these patients should be informed of the possibility of mild residual pain and persistent leg length discrepancy, particularly patients whose THA is performed on the limb that was not affected by polio (ie, the nonparalytic contralateral limb). LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Subchondral insufficiency fracture of the femoral head in elderly people.

We evaluated the clinical course of subchondral insufficiency fracture of the femoral head (SIFFH) and its characteristic findings with special regard to joint space narrowing (JSN). Thirty-one cases of SIFFH of mean age 68.9 yr initially underwent limited weight-bearing conservative treatment. During the follow-up period, the patients with intractable pain underwent total hip arthroplasty (THA). For radiographic evaluation, lateral center-edge angle, JSN and femoral head collapse (FHC) were documented, and the extent of FHC was classified as mild (<2 mm), moderate (2-4 mm), and severe (>4 mm). The progression or new development of FHC more than 2 mm was evaluated on sequential plain radiographs. The relationship between radiographic parameters and clinical outcomes were evaluated. THAs were performed in 15 cases (48.4%). There was no significant correlation between clinical outcomes and the extent of initial FHC. However, a significantly larger proportion of patients that underwent THA showed JSN and FHC progression compared to the symptom improvement group. The risk factor significantly associated with failed conservative treatment was JSN (P=0.038; OR, 11.8; 95% CI, 1.15-122.26). Clinical results of conservative treatment for SIFFH in elderly patients are relatively poor. The patients with JSN are at higher risk of failed conservative treatment.

Incidence and risk factors of symptomatic peripartum diastasis of pubic symphysis.

This study was undertaken to determine incidence, associated risk factors, and clinical outcomes of a diastasis of pubic symphysis. Among 4,151 women, who delivered 4,554 babies at the Department of Obstetrics of Seoul National University Bundang hospital from January 2004 to December 2006, eleven women were diagnosed as having a symptomatic diastasis of pubic symphysis. We estimated the incidence of the diastasis and identified the associated risk factors. To evaluate the pain relief and reduction of diastasis we followed up the 11 diastatic patients. The incidence of the diastasis was 1/385. Primiparity (P = 0.010) and twin gestation (P = 0.016) appeared as risk factors for diastasis by univairable analysis; and twin gestation appeared to be the only risk factor (P = 0.006) by logistic analysis. Two patients were operated due to intractable pain; and the remaining nine patients were treated conservatively. The diastatic gap decreased to less than 1.5 cm by 2 to 6 weeks after the diagnosis and then remained stationary. At a mean follow-up of 22.1 months (range, 12 to 47 months), five of 11 patients had persistent symphysis pubis dysfunction. Diastasis is more frequent than generally acknowledged. Pregnant women with multiple gestations should be informed about the potential risk of pubic symphysis diastasis.

Epidemiology of hip replacements in Korea from 2007 to 2011.

We analyzed national data collected by the Health Insurance Review and Assessment Service in Korea from 2007 to 2011; 1) to document procedural numbers and procedural rate of bipolar hemiarthroplasty (BH), primary and revision total hip arthroplasties (THAs), 2) to stratify the prevalence of each procedure by age, gender, and hospital type, and quantified, 3) to estimate the revision burden and evaluate whether the burden is changed over time. Our final study population included 60,230 BHs, 40,760 primary THAs, and 10,341 revision THAs. From 2007 to 2011, both the number and the rate of BHs, primary THAs increased steadily, whereas there was no significant change in revision THAs. Over the 5 yr, the rate of BHs and primary THAs per 100,000 persons significantly increased by 33.2% and 21.4%, respectively. The number of revision THAs was consistent over time. The overall annual revision burden for THA decreased from 22.1% in 2007 to 18.9% in 2011. In contrast to western data, there were no changes in the number and rate of revision THAs, and the rates of primary and revision THAs were higher for men than those for women. Although 5 yr is a short time to determine a change in the revision burden, there have been significant decreases in some age groups.

Trends in Hospital Stay, Complication Rate, and Mortality in Hip Fracture Patients: A Two-Decade Comparison at a National Tertiary Referral Center.

Background: Since the turn of the century, the age-adjusted incidence of proximal femoral fractures has caused a plateau or fall. However, it was anticipated that the number of patients with proximal femoral fractures would rise as life expectancy rose and the population over 80 years old expanded. The aim of this study was to compare the length of hospital stay, complication rate, and mortality in patients with proximal femoral fractures between two different time periods: 20 years ago and the present. Methods: We conducted a retrospective review of medical records of patients aged 65 years and above who underwent surgery for proximal femoral fractures between January 2000 and December 2001 and between January 2020 and December 2021. We collected information on age, gender, fracture type, length of hospital stay, and complication rate. Dates of death were obtained from the Ministry of the Interior and Safety. Results: We included 136 patients who were operated on between 2000 and 2001 and 134 patients between 2020 and 2021. The average age increased significantly from 71.6 years to 79.0 years (p < 0.001). The length of hospital stay decreased dramatically from 15.1 days to 6.0 days (p < 0.001). There was no statistically significant difference in delirium, urinary tract infection, or pneumonia. No difference was found in 30-day or 1-year mortality between the two groups. Conclusions: The complication rate and mortality between the two time periods appeared comparable, although the length of hospital stay decreased substantially. Therefore, we recommend considering expedited discharge from the acute care hospital for elderly hip fracture patients while implementing an individualized approach for better outcomes.

Revision total hip arthroplasty using an alumina-on-alumina bearing surface in patients with osteolysis.

We evaluated the outcomes of 64 consecutive revision total hip arthroplasties with an alumina-on-alumina bearing surface in 61 patients with osteolysis. No implants had been rerevised nor was osteolysis detected at a mean of 9.8 years (range, 7.0-13.1 years) postoperatively. There was 1 case of stem loosening but no cup loosening or alumina bearing fractures. Two surgical procedures were performed for an infection in 1 patient. Three dislocations occurred in 3 hips; all were treated with closed reduction and abduction bracing for 3 months. No further dislocations occurred. With any reoperation or radiographic evidence of osteolysis or loosening as the end point, the 7-year survival rate was 96.9% (95% confidence interval, 90.8%-100%). The alumina-on-alumina bearing surfaces used for revision total hip arthroplasty in patients with osteolysis were found to produce encouraging clinical results and implant survival rates at a minimum of 7 years postoperatively.

Medial placement of the acetabular component in an alumina-on-alumina total hip arthroplasty: a comparative study with propensity score matching.

PURPOSE: In an alumina-on-alumina total hip arthroplasty (THA), recommended with a small inclination angle <45°, the acetabular component (cup) may be positioned more medially to be covered almost completely by host bone. The purpose of this study was to identify the correlating factors and to evaluate the outcomes of medial placement of the cup in patients with alumina-on-alumina THAs. METHODS: Using the propensity score matching with age, gender, body mass index, initial diagnosis, and the length of follow-up as variables, 38 hips with a medialized cup and 38 hips with a non-medialized one were identified from 389 hips in 347 who patients underwent primary alumina-on-alumina THA and followed up for more than 7 years. Clinical and radiological outcomes were compared between the two groups. RESULTS: Preoperative acetabular medial wall thickness and the cup inclination angle were significantly smaller in the medialization group compared to the non-medialization group. Center edge angle, cup size, and coverage by host bone were not significantly different between the two groups. The hip center of rotation was significantly medialized in the medialization group. The Harris hip scores were not significantly different between the two groups. No component loosening or osteolysis was observed and no revision was required in either groups. CONCLUSIONS: Thin acetabular medial wall and a small inclination angle of the cup were the correlating factors of medial placement of the cup in patients who underwent an alumina-on-alumina THA. Medial placement did not lead to differences in the clinical or radiological outcomes.

Distal femoral cortical proliferative irregularity with excavation in a 6-year-old girl.

The distal femur is a common site for benign or malignant bone tumors in children or adolescents. Distal femoral cortical irregularities at the posterior aspect of the distal femoral metaphysis must be differentiated from malignant bone tumors because they might be misinterpreted as malignant neoplasm. Plain radiographs of a 6-year-old girl complaining of left knee pain for 4 weeks showed cortical proliferation with excavation on her distal femoral metaphysis. Computed tomography, magnetic resonance imaging and bone scan helped to differentiate the cortical irregularity from malignant lesions. Therefore unnecessary invasive surgery was avoided in this patient.

Factors Affecting the Clinical Course of Subchondral Fatigue Fracture of the Femoral Head.

Background: Subchondral fatigue fracture of the femoral head (SFFFH) is a rare disease, and its disease entity is established in recent decades. Although there are a few studies on SFFFH, most of them are case series involving around 10 cases, and the clinical course of SFFFH is still not well known. This study analyzed the factors affecting the clinical course of SFFFH. Methods: Patients who visited our institution from October 2000 to January 2019 were retrospectively evaluated. Of eligible cases, 89 hips (80 patients) were diagnosed with SFFFH and non-surgical treatment outcomes were analyzed. Radiographs and medical charts were reviewed for following factors: the degree of femoral head collapse, the interval between the onset of hip pain and the first hospital visit, hip dysplasia, osteoarthritic changes, sex, and age. Results: Hip pain decreased in 82 cases (92.1%) through non-surgical treatment, and 7 cases (7.9%) underwent surgery. Patients with good results of non-surgical treatment had improvement 2.9 months on average after the treatment. All cases without a collapsed femoral head (55 cases) had hip pain alleviation through non-surgical treatment. Cases with femoral head collapse of 4 mm or less and non-surgical treatment within 6 months from the onset of hip pain (22 cases) all had hip pain alleviation. Among 8 cases with femoral head collapse of 4 mm or less and non-surgical treatment after 6 months or more from the onset of hip pain, 3 underwent surgery and 1 had persistent hip pain. Those with femoral head collapse of over 4 mm (3 cases) all underwent surgery. The osteoarthritic changes, dysplastic hip, sex, and age were not statistically related to the success of non-surgical treatment. Conclusions: The success of non-surgical treatment for SFFFH can be affected by the degree of femoral head collapse and the timing of non-surgical treatment.

Midterm Results of Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Human Immunodeficiency Virus-Infected Patients in South Korea.

Background: Studies have reported that osteonecrosis of the femoral head (ONFH) is more prevalent in patients with human immunodeficiency virus (HIV). Total hip arthroplasty (THA) is considered reasonable management of ONFH. However, only scarce data exist on the outcomes of THA for HIV-infected patients in South Korea. The purpose of this study was to evaluate the midterm results of HIV-positive patients who underwent THA for ONFH. Methods: We performed a retrospective review of HIV-infected patients with ONFH who underwent THA in our institution from 2005 to 2021. Twenty-two hips in 15 patients underwent THAs with cementless implants. The clinical and radiographic evaluation was performed at each follow-up, and any complication was recorded. Results: The mean follow-up period was 5.2 years (range, 1.0-16.0 years). The mean age of the HIV infected patients with osteonecrosis at the time of surgery was 44.7 ± 11.6 years. ONFH occurred 9.8 ± 3.7 years after the initial diagnosis of HIV infection. The average modified Harris hip score improved from 58.3 ± 14.8 to 95.2 ± 11.3 at the latest follow-up. Surgical complications such as infection, nerve injury, or dislocation were not present. The radiographic evidence of stable fixation by bone ingrowth without migration was seen in all implants. Conclusions: Our data suggest that THA is a safe and valid option of treatment for ONFH in well-controlled HIV-infected patients in Korea. Further large-scale nationwide studies are warranted.