In osteosarcoma, treatment guidelines recommend standard chemotherapy regardless of severity of disease. Treatment individualization will minimize risk of failure and adverse effects, specially in patients who have good prognosis. Therefore, there is a pressing clinical need to develop a risk adapted strategies and to adjust chemotherapy to prognostic factors. Aim: to asses usefulness of Classification and
Controversy persists over whether cemented or uncemented fixation is more effective in reducing revision and mortality risks following primary total hip arthroplasty (THA). Despite a shift towards uncemented THA in Europe, Australia, and the US, no consensus exists on superior outcomes. This ambiguity in evidence from randomized controlled trials (RCTs) and observational studies necessitates advanced research methodologies to derive more definitive conclusions. This study investigates the causal impact of THA fixation type on 2-year and 5-year revision rates, along with 90-day mortality, utilizing a regression discontinuity (RD) design in scenarios where fixation choice is guided by patient age. Employing data from the Dutch Arthroplasty Register, we conducted a cohort study on primary THAs for osteoarthritis from 2007 to 2019. A “fuzzy” RD design was executed to compute the Local Average Treatment Effect for subjects around the age-based selection threshold for fixation type. The main outcome of interest was the revision rate at 2 years post-operation. Analysis for the 2-year revision endpoint, covering any cause, included 2,344 females and 1,671 males across 5 hospitals each, with no significant variation in revision rates observed. For the 5-year mark, 1,058 females in 3 hospitals and 214 males in 1 hospital were examined, similarly showing no significant differences. Mortality within 90 days post-operation was also investigated in 5 female and 7 male cohorts, with 2,180 and 2,145 surgeries respectively, yielding no substantial disparities. In conclusion, the RD analysis revealed no notable differences in revision rates at 2 and 5 years or in early mortality based on the fixation method used in THA. These outcomes suggest that the age-based preference for THA fixation may not influence the revision or mortality risk, underscoring the value of RD design in deriving causal insights from observational data.
Thigh-calf contact force is the force acting on posterior side of the thigh and calf during deep knee flexion. It has been reported the force is important to analyze the kinetics of a lower limb and a knee joint. Some previous researches reported the measured thigh-calf contact force, however, the values varied among the reports. Furthermore, the reports indicated that there were large variations even in a single report. One of the reports tried to find the relationship between the magnitude of thigh-calf contact force and anthropometric measurement as height, weight or perimeter of the lower limb, however, there could not found clear correlations. We considered that the cause of the variations might be the difference of the posture. At heel-rise squatting posture, we can bend or stand upright the upper body. Therefore we tried to create the equation to estimate the thigh-calf contact force by multiple regression analysis, using the anthropometric and posture parameters as explanatory variables. We performed the experiment to measure thigh-calf contact force, joint angles and anthropometric information. Test subjects were 10 healthy male. First we measured their height, weight, perimeter of the thigh and muscle mass of the legs and whole body. Muscle mass was measured by body composition meter (BC-118E, Tanita Co., Japan). Then, test subjects were asked to squat with their heels lifted and with putting the pressure distribution sensor between thigh and calf. And they bent their upper body forward and backward. The pressure sensor to be used was ConfroMat System (Nitta Co., Japan). After that, we measured the joint angles of the hip, knee and ankle, and the angle between the floor and upper body using the videos taken during the experiment. Then, we created the equation to estimate the thigh-calf contact force by linear combination of the anthropometric values and joint angles. The coefficients were settled as to minimize the average error between measured and estimated values. Results are shown in Fig.1. Forces were normalized by the body weight of the test subjects. Because the horizontal axes show the measured and vertical axis show the estimated values, the estimation is accurate when the plots are near the 45-degree line. Average error was 0.11BW by using only physical values, 0.15BW by angles and 0.06BW using both values. And the maximum error was 0.69BW, 0.43BW and 0.32BW respectively. Thus we could estimate the thigh-calf contact force by multiple regressions, using both physical parameters and angles to indicate the posture. Using the equation, we would be able to analyze the kinetics of a lower limb by physical and motion measurement. Our future work might be increasing the number of subjects to consider the appropriateness, because the test subjects of this study were very limited.
Background The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12–61). There were 235 females (47%) and 268 males (53%) with a 6 % rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6–10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95% confidence interval [CI] = 0.80–0.93; P = .001] and smaller graft size (OR = 0.36; 95% CI = 0.18–0.70; P = .003) were significantly predictive of re-tear. Female sex was correlated with re-tear but was not significant (OR = 1.8; 95% CI = 0.84–3.97; P = .13). Multivariate analysis with all 3 variables in the model showed similar significant results. Graft size < 8 mm (OR = 2.95; 95% CI = 1.33–6.53; P = .008) and age < 25 (OR = 7.01; 95% CI = 2.40–20.53; P = .001) were significantly predictive of re-tear. Entire model was statistically significant (Omnibus test P = .001; Hosmer-Lemeshow statistic P = .68; Receiver Operating Curve [ROC] = 0.8). Surgeons should counsel their patients who are female, younger than 25 and with a graft size less than 8 mm accordingly and consider modifying their surgical or rehabilitation techniques to mitigate these re-tear risks.
A case of advanced retroperitoneal leiomyosarcoma is reported in a patient, who experienced a complete regression of her fatal illness. A 66-year old woman presented with a 1-year history of intermittent lower abdominal pain. An ultrasonogram (USG) and computed tomography (CT-scan) revealedmultiple soft tissue masses particularly in the lower retroperitoneal space and also 3 liver nodules. USG-guided biopsy was done and histologically confirmed poorly differentiated leiomyosarcoma. The patient underwent successful macroscopically complete en bloc resection of all tumor masses with the exception of 12 liver metastases which had been resected 6 weeks after the initial surgery. 11 months later USG showed disease progression with diffuse inoperable liver metastases, intraperitoneal and retroperitoneal tumor nodules. We introduced salvage chemotherapy (ChT), using intravenous infusion of ifosfamide 1.8 g/m2 on days 1–3 with mesna, and intravenous bolus injection of doxorubicin 60 mg/m2 on day 1. After 4 courses of treatment USG showed partial regression of metastatic disease. When the patient received the 8th, i.e. the last cycle of ChT, USG confirmed further disease regression with only 2 residual metastases in liver. 6 months later USG showed further regression of liver metastases. Another follow-up USG at 9 months and 12 months did not reveal evidence of residual metastases. Almost 2 years after the end of ChT the patient is asymptomatic, well and has no evidence of disease at 41 months after the diagnosis. The “spontaneous” further regression of metastatic leiomyosarcoma after the end of salvage ChT in our patient would be exceptional phenomena. Although we cannot exclude the remote possibility of “delayed” further response to ChT, generally poor response rate to ChT in leiomyosarcoma would make it very unlikely.
Not all patients receive enhanced mobility and return to comfortable, independent living after Total Hip Arthroplasty (THA). It would be beneficial to both surgeons and patients to be able to predict short term outcomes for THA. The purpose of this study was to investigate factors affecting the short term outcome of primary THA and develop a multivariate regression model that can predict such outcomes. This was a prospective study of 101 patients, who underwent primary THA. All patients were followed for a minimum of 1 year. 12 independent variables, including age, gender, diagnosis, presence of preoperative comorbidities, BMI, preoperative WOMAC physical component (PC) score, type of anesthesia, type of fixation, surgical time, estimated blood loss, use of a postoperative drain, and length of stay were analyzed using correlation and multivariate regression analyses. Multivariate regression models were validated using an independent cohort. Correlation analyses showed three variables significantly influence short term THA outcome. These include preoperative WOMAC PC score (PC) (p<
0.01), gender (G) (p= 0.01) and the presence of preoperative comorbidities (CMB) (p= 0.02). By multivariate regression analysis, the following regression model was obtained: Outcome = PC*0.45 −G*9 + CMB*8 + 62. This model exhibited positive correlation (R2=.25) when compared to a separate cohort of 27 patients undergoing THA not included in the original equation derivation. Our multivariate regression analysis has yielded statistical, multivariate confirmation or non-confirmation of common, predictive THA factors that have previously been reported in the literature. This study provides a concrete, statistically significant measure indicating that preoperative WOMAC PC score, gender, and the presence of preoperative comorbidities are predictive factors for short term primary THA outcome. Finally, our multivariate regression equation can be used to predict the general short term patient outcome following primary THA.
The integration of statistical shape models (SSMs) for generating a patient-specific model from sparse data is widely spread. The SSM needs to be initially registered to the coordinate-system in which the data is acquired and then be instantiated based on the point data using some regressing techniques such as principal component analysis (PCR). Besides PCR, partial least squares regression (PLSR) could also be used to predict a patient-specific model. PLSR combines properties of PCR and multiple linear regression and could be used for shape prediction based on morphological parameters. Both methods were compared on the basis of two SSMs, each of them constructed from 30 surface models of the proximal femur and the pelvis, respectively. Thirty leave-one-out trials were performed, in which one surface was consecutively left out and further used as ground truth surface model. Landmark data were randomly derived from the surface models and used together with the remaining 29 surface models to predict the left-out surface model based on PCR and PLSR, respectively. The prediction accuracy was analysed by comparing the ground truth model with the corresponding predicted model and expressed in terms of mean surface distance error. According to their obtained minimum error, PCR (1.62 mm) and PLSR (1. 63 mm) gave similar results for a set of 50 randomly chosen landmarks. However PLSR seems to be more susceptible to a wrong selection of number of latent vectors, as it has a more variation in the error. Although both regression methods gave similar results, decision needs to be done, how to select the optimal number of regressors, which is a delicate task. In order to predict a surface model based on morphological parameters using PLSR, the choice of the parameters and their optimal number needs to be carefully selected.
Introduction. The increased prevalence of osteoporosis in the patient population undergoing reverse shoulder arthroplasty (RSA) results in significantly increased complication rates. Mainly demographic and clinical predictors are currently taken into the preoperative assessment for risk stratification without quantification of preoperative computed tomography (CT) data (e.g. bone density). It was hypothesized that preoperative CT bone density measures would provide objective quantification with subsequent classification of the patients’ humeral bone quality. Methods. Thirteen bone density parameters from 345 preoperative CT scans of a clinical RSA cohort represented the data set in this study. The data set was divided into testing (30%) and training data (70%), latter included an 8-fold cross validation. Variable selection was performed by choosing the variables with the highest descriptive value for each correlation clustered variables. Machine learning models were used to improve the clustering (Hierarchical Ward) and classification (Support Vector Machine (SVM)) of bone densities at risk for complications and were compared to a conventional statistical model (Logistic
Aims. The aim of this study was to identify factors associated with poor outcome following coccygectomy on patients with chronic coccydynia and instability of the coccyx. Methods. From the Danish National Spine Registry, DaneSpine, 134 consecutive patients were identified from a single centre who had coccygectomy from 2011 to 2019. Patient demographic data and patient-reported outcomes, including pain measured on a visual analogue scale (VAS), Oswestry Disability Index (ODI), EuroQol five-dimension five-level questionnaire, and 36-Item Short-Form Health Survey questionnaire (SF-36) were obtained at baseline and at one-year follow-up. Patient satisfaction was obtained at follow-up.
Aims. To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Methods. Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included “brace treatment” or “bracing,” “idiopathic scoliosis,” and “curve regression” or “curve reduction.” Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication. Results. After abstract and full-text screening, 205 out of 216 articles were excluded. The 11 included studies all reported occurrence of curve regression among AIS patients who were braced.
Aims. Pain is the most frequent complaint associated with osteonecrosis of the femoral head (ONFH), but the factors contributing to such pain are poorly understood. This study explored diverse demographic, clinical, radiological, psychological, and neurophysiological factors for their potential contribution to pain in patients with ONFH. Methods. This cross-sectional study was carried out according to the “STrengthening the Reporting of OBservational studies in Epidemiology” statement. Data on 19 variables were collected at a single timepoint from 250 patients with ONFH who were treated at our medical centre between July and December 2023 using validated instruments or, in the case of hip pain, a numerical rating scale. Factors associated with pain severity were identified using hierarchical multifactor linear regression. Results.
The ability to calculate quality-adjusted life-years (QALYs) for degenerative cervical myelopathy (DCM) would enhance treatment decision making and facilitate economic analysis. QALYs are calculated using utilities, or health-related quality-of-life (HRQoL) weights. An instrument designed for cervical myelopathy disease would increase the sensitivity and specificity of HRQoL assessments. The objective of this study is to develop a multi-attribute utility function for the modified Japanese Orthopedic Association (mJOA) Score. We recruited a sample of 760 adults from a market research panel. Using an online discrete choice experiment (DCE), participants rated 8 choice sets based on mJOA health states. A multi-attribute utility function was estimated using a mixed multinomial-logit regression model (MIXL). The sample was partitioned into a training set used for model fitting and validation set used for model evaluation. The regression model demonstrated good predictive performance on the validation set with an AUC of 0.81 (95% CI: 0.80-0.82)). The regression model was used to develop a utility scoring rubric for the mJOA.
Acute Haematogenous Osteomyelitis (AHO) remains a cause of severe illness among children. Contemporary research aims to identify predictors of acute and chronic complications. Trends in C-reactive protein (CRP) following treatment initiation may predict disease course. We have sought to identify factors associated with acute and chronic complications in the New Zealand population. A retrospective review of all patients <16 years with presumed AHO presenting to a tertiary referral centre between 2008–2018 was performed. Multivariate was analysis used to identify factors associated with an acute or chronic complication. An “acute” complication was defined as need for two or more surgical procedures, hospital stay longer than 14-days, or recurrence despite IV antibiotics. A “chronic” complication was defined as growth or limb length discrepancy, avascular necrosis, chronic osteomyelitis, pathological fracture, frozen joint or dislocation. 151 cases met inclusion criteria. The median age was 8 years (69.5% male). Within this cohort, 53 (34%) experienced an acute complication and 18 (12%) a chronic complication.
Introduction. A common acute orthopaedic presentation is an ulcerated or infected foot secondary to diabetic neuropathy. Surgical debridement or amputation are often required to manage this complication of diabetes. International literature indicates that amputation may lead to further complications and an increased mortality rate. The aim of this study is to investigate the mortality rate associated with different surgical interventions. This will inform surgical management of patients presenting with acute foot complications from diabetes. Methods. This is a retrospective review of patients with diabetic foot infections aged >16 years attending Middlemore Hospital over a 10-year period (2012–2021). Clinical records were examined to determine whether patients were managed with no surgery, surgery but not amputation, or amputation. We recorded relevant baseline characteristics and comorbidities.
Aim. Ankle fracture surgery comes with a risk of fracture-related infection (FRI). Identifying risk factors are important in preoperative planning, in management of patients, and for information to the individual patient about their risk of complications. In addition, modifiable factors can be addressed prior to surgery. The aim of the current paper was to identify risk factors for FRI in patients operated for ankle fractures. Method. A cohort of 1004 patients surgically treated for ankle fractures at Haukeland University hospital in the period of 2015–2019 was studied retrospectively. Patient charts and radiographs were assessed for the diagnosis of FRI. Binary logistic regression was used in analyses of risk factors.
The influence of patient age on functional outcomes after periacetabular osteotomy (PAO) for acetabular dysplasia remains unclear, with previous studies utilising scores developed for older, arthritic patients. The purpose of this study is to assess the influence of patient age on International Hip Outcome Tool (iHOT-12) scores, two years after PAO. Eighty-six patients (72 female, 14 male; mean age 26.9 years) who underwent PAO by a single surgeon and had completed a minimum of two years follow up were identified. Patients were categorised into three groups according to age at the time of surgery: adolescent (11–20 years; n=29), young adult (21–30 years; n=29), and mature (≥31 years; n=28). The three groups were compared with respect to baseline variables and functional outcomes (iHOT-12, EQ-5D quality of life score, University of California Los Angeles (UCLA) activity score, pain visual analogue score (VAS)). Multivariate regression was undertaken to assess for independent predictors of two-year iHOT-12 score. The adolescent group demonstrated a lower BMI (p=0.004) while the mature group had a greater American Society of Anaesthesiology (ASA) score (p=0.049). There were otherwise no significant differences in baseline variables between the three groups (all p>0.05). The three groups demonstrated significant post-operative improvements across all functional outcome measures. There were no significant differences in two-year iHOT-12, EQ-5D, UCLA score or pain VAS between the three groups (all p>0.05).
We aimed to determine the rate of and risk factors for post-traumatic osteoarthritis (PTOA) and total knee arthroplasty (TKA) requirement after operative management of tibial plateau fractures (TPF) in older adults. We conducted a retrospective cohort study of 182 operatively managed TPFs in 180 patients ≥60 years old over a 12-year period with minimum follow up 1 year. Data including patient demographics, clinical frailty scores, mechanism of injury, management, reoperation and mortality were recorded. Radiographs were reviewed for: Schatzker classification; pre-existing knee osteoarthritis (KOA); severe joint depression >15mm; and development of PTOA. Kaplan Meier survival analysis was performed.