Hip Deformity Research Articles

Etiology of Femoroacetabular Impingement in Athletes: A Review of Recent Findings.

The relationship between hip deformities and osteoarthritis has recently received a lot of attention. In particular, it has been shown that both osteoarthritis and its precursors, such as the hip deformities that lead to femoroacetabular impingement (FAI), are more prevalent in elite athletes compared with the general population. However, the etiology of the above-mentioned types of hip deformity is not currently well understood. Many recent studies have attempted to shed light on the etiology of this disease. In this article, the main clinical, radiological, mechanobiological, and biomechanical findings of relevance to understanding the etiology of hip deformities leading to FAI are reviewed. Based on these findings, a consistent biomechanical theory explaining the development of hip deformities in athletes is then presented. According to the presented theory, the repetitive, impact-like musculoskeletal loads that athletes experience, particularly when they undertake extreme ranges of hip motion, cause the development of hip deformities. According to this theory, these musculoskeletal loads trigger abnormal growth patterns during the years of skeletal development and cause the formation of hip deformities. A number of hypotheses based on the proposed theory are then formulated that could be tested in future studies to ascertain whether the proposed theory could sufficiently describe the development of hip deformities in athletes.

The Prevalence of Radiographic Findings of Structural Hip Deformities in Female Collegiate Athletes

Background: Structural deformities of the hip, including femoroacetabular impingement (FAI) and acetabular dysplasia, often limit athletic activity. Previous studies have reported an increased prevalence of radiographic cam FAI in male athletes, but data on the prevalence of structural hip deformities in female athletes are lacking. Purpose: (1) To quantify the prevalence of radiographic FAI deformities and acetabular dysplasia in female collegiate athletes from 3 sports: volleyball, soccer, and track and field. (2) To identify possible relationships between radiographic measures of hip morphologic characteristics and physical examination findings. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Anteroposterior (AP) pelvis and frog-leg lateral radiographs were obtained from 63 female athletes participating in Division I collegiate volleyball, soccer, and track and field. Lateral center edge angle (LCEA) and acetabular index were measured on AP films. Alpha angle and head-neck offset were measured on frog-leg lateral films. Pain during the supine impingement examination and hip rotation at 90° of flexion were recorded. Random-effects linear regression was used for group comparisons and correlation analyses to account for the lack of independence of observations made on left and right hips. Results: Radiographic cam deformity (alpha angle >50° and/or head-neck offset <8 mm) was found in 48% (61/126) of hips. Radiographic pincer deformity (LCEA >40°) was noted in only 1% (1/126) of hips. No hips had radiographic mixed FAI (at least 1 of the 2 cam criteria and LCEA >40°). Twenty-one percent (26/126) of hips had an LCEA <20°, indicative of acetabular dysplasia, and an additional 46% (58/126) of hips had borderline dysplasia (LCEA ≥20° and ≤25°). Track and field athletes had significantly increased alpha angles (48.2° ± 7.1°) compared with the soccer players (40.0° ± 6.8°; P < .001) and volleyball players (39.1° ± 5.9°; P < .001). There was no significant difference in the LCEA (all P > .914) or the prevalence of dysplasia (LCEA <20°) between teams (all P > .551). There were no significant correlations between the radiographic measures and internal rotation (all P > .077). There were no significant differences (all P > .089) in radiographic measures between hips that were painful (n = 26) during the impingement examination and those that were not. Conclusion: These female athletes had a lower prevalence of radiographic FAI deformities compared with previously reported values for male athletes and a higher prevalence of acetabular dysplasia than reported for women in previous studies.

Predictive genetic markers of coagulation, inflammation and apoptosis in Perthes disease—Serbian experience.

Perthes disease is one of the most common forms of pediatric femoral head osteonecrosis with an unknown etiology. Coagulation factors were the first genetic factors suspected to have a role in the pathogenesis of this disease, but studies showed inconsistent results. It is described that inflammation is present during early stages of Perthes disease, but its genetic aspect has not been studied extensively. Little is known regarding the status of apoptotic factors during the repair process that leads to the occurrence of hip deformity in patients. Therefore, the aim of this study was to analyze major mediators involved in coagulation, inflammation, and apoptotic processes as possible causative factors of Perthes disease. The study cohort consisted of 37 patients. Gene variants of TNF-α, FV, FII, and MTHFR genes were determined by PCR-RFLP, while IL-3 and PAI-1 were genotyped by direct sequencing. The expression level of Bax, Bcl-2, Bcl2L12, Fas and FasL was analyzed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) technique. Our results showed a significantly increased level of expression of pro-apoptotic factor Bax along with significantly higher Bax/Bcl-2 ratio in the patient group. The results presented indicate that apoptosis could be one of the factors contributing to the lack of balanced bone remodeling process in Perthes patients.

Sportsmen's groin. Definition, differential diagnostics and therapy

Groin pain in athletes is a common problem and can have extensive consequences for professional athletes. The anatomical and functional complexity of the groin as well as radiating pain from remote anatomical regions can make the differential diagnostic a challenge and requires special attention. As there are a wide variety of possible causes for groin pain, a multidisciplinary approach is required. The treating orthopedic surgeon needs to pay special attention to prearthritic hip deformities to avoid irreversible damage of the hip joint. By a meticulous patient history and identification of the pain character, followed by clinical, sonographic and radiographic investigations, a differential diagnosis can usually be achieved. Besides typical orthopedic causes pathological findings particularly in the area of the groin need to be considered, clarified and adequately treated; therefore, a clear terminology of the different diseases is necessary. Sportsmen's groin is not a hernia but should be perceived as a separate entity due to its typical pain character and detection of a measurable protrusion of the posterior wall of the inguinal canal by ultrasound.

Does surgical hip dislocation and periacetabular osteotomy improve pain in patients with Perthes-like deformities and acetabular dysplasia?

Patients with symptomatic residual Perthes-like deformities may present with a combination of structural abnormalities including a large aspheric femoral head, short and wide femoral neck, high greater trochanter, and acetabular dysplasia. Sometimes, the hip is further compromised by concurrent symptomatic femoroacetabular impingement (FAI) (proximal femoral deformities) and structural instability (acetabular dysplasia). We therefore sought to characterize (1) the intraoperative findings; (2) radiographic correction; and (3) early patient-reported outcomes, complications, and failures of treating complex Perthes-like hip deformities with combined surgical dislocation and periacetabular osteotomy (PAO). We performed 694 hip preservation procedures between November 2006 and August 2010. Of these, 46 had residual Perthes-like hip deformities, defined as proximal deformity consistent with residual Perthes and a history of Perthes disease or treatment of pediatric hip dysplasia. Of these, we report on 16 patients (16 hips) with residual Perthes-like hip deformities and associated acetabular dysplasia (structural instability, defined as radiographic evidence of acetabular dysplasia with intraoperative confirmation of instability). These 16 patients were treated with a combined surgical hip dislocation to comprehensively address intraarticular and extraarticular sources of FAI and PAO to address structural instability and were analyzed at a minimum 24-month followup (median, 40 months; range, 24-78 months). No patients in this series were lost to followup. Ten patients' hips had previous surgical treatment, including six with previous osteotomy. Operative findings were extracted from standardized prospectively collected intraoperative data collection forms. Radiographic correction was evaluated with established methods (lateral center-edge angle, anterior center-edge angle, acetabular inclination, center-to-trochanter distance) and clinical outcomes were measured with the modified Harris hip score (mHHS) as well as by prospectively recorded data on patient complications and followup. Acetabular labrochondral abnormalities included labral hypertrophy in all hips and labral and/or articular cartilage lesions requiring treatment in 13 hips. Radiographic analysis demonstrated consistent radiographic correction. The median preoperative mHHS improved from 64 to 92 at a median followup of 40 months (p < 0.001). Fourteen patients (14 hips) had a good or excellent clinical result. Two patients (two hips) were classified as failures based on mHHS less than 70 (n = 1) or conversion to total hip arthroplasty (n = 1). Combined surgical hip dislocation and PAO provides major deformity correction in Perthes-like hip deformities with associated acetabular dysplasia. Early clinical results suggest this technique is safe and effective. Long-term studies are needed to determine if improved long-term outcomes are associated with comprehensive deformity correction.

Biomechanics of foetal movement.

Foetal movements commence at seven weeks of gestation, with the foetal movement repertoire including twitches, whole body movements, stretches, isolated limb movements, breathing movements, head and neck movements, jaw movements (including yawning, sucking and swallowing) and hiccups by ten weeks of gestational age. There are two key biomechanical aspects to gross foetal movements; the first being that the foetus moves in a dynamically changing constrained physical environment in which the freedom to move becomes increasingly restricted with increasing foetal size and decreasing amniotic fluid. Therefore, the mechanical environment experienced by the foetus affects its ability to move freely. Secondly, the mechanical forces induced by foetal movements are crucial for normal skeletal development, as evidenced by a number of conditions and syndromes for which reduced or abnormal foetal movements are implicated, such as developmental dysplasia of the hip, arthrogryposis and foetal akinesia deformation sequence. This review examines both the biomechanical effects of the physical environment on foetal movements through discussion of intrauterine factors, such as space, foetal positioning and volume of amniotic fluid, and the biomechanical role of gross foetal movements in human skeletal development through investigation of the effects of abnormal movement on the bones and joints. This review also highlights computational simulations of foetal movements that attempt to determine the mechanical forces acting on the foetus as it moves. Finally, avenues for future research into foetal movement biomechanics are highlighted, which have potential impact for a diverse range of fields including foetal medicine, musculoskeletal disorders and tissue engineering.

Idiopathic chondrolysis of hip: a case report

Idiopathic chondrolysis of the hip is a rare condition occurring mainly in adolescents and is characterised by a rapidly progressive destruction of the articular cartilage. A male patient aged 18 years presented to us with pain in his left hip, restriction of movements, and limping due to pelvic obliquity. On examination patient had severe tenderness over left hip, fixed flexion and abduction deformity were present and all movements were painful. Radiographic imaging showed narrowing of joint space, irregular blurring of subchondral sclerotic lines and femoral neck widening. MRI scan depicts marrow changes earlier than any other imaging method. Biological markers for inflammation and infections have been studied, which was normal. To achieve mobile hip, for this patient we planned for Total hip replacement after confirming our diagnosis. Idiopathic chondrolysis of the hip is a rare clinical entity where, unfortunately, there is often a delay in diagnosis. There are characteristic clinical and radiological features but no effective therapy to arrest the disease. Until today no evidence concerning the aetiology of ICH has been presented. Therefore the treatment is mainly symptomatic. Conservative treatment focuses on pain control and preservation of joint mobility. Physiotherapy seems to be important to preserve a good range of motion. In addition most authors agree to unload the affected hip joint by means of bed rest and skin traction. Published results of surgical treatment are not conclusive and arthroplasty in young patients is controversial. There is no consensus on the treatment algorithm. Recommended surgical treatments include corrective osteotomy, bony fusion or joint arthroplasty. Awareness of the existence of this disease will lead to earlier diagnosis and management.

“Syndrome of Contractures and Deformities” According to Prof. Hans Mau as the Primary Cause of Hip, Neck, Shank and Spine Deformities in Babies, Youth and Adults

“Syndrome of Contractures and Deformities” According to Prof. Hans Mau as the Primary Cause of Hip, Neck, Shank and Spine Deformities in Babies, Youth and Adults

Mosaicplasty for the treatment of osteochondritis dissecans following Legg-Calvé-Perthes' disease. A case report and literature review

Legg-Calvé-Perthes disease leads to hip joint deformity. Osteochondritis dissecans following Perthes disease (OCDP) is a less common entity. Treatment options of OCDP are limited. Osteochondral autologous transfer (OATS) is an established method of treatment of full thickness cartilage defects in different locations. This paper presents the case of a 42-year-old patient diagnosed with symptomatic OCDP and treated with lesion fixation using autologous osteochondral grafts via surgical hip dislocation. At the most recent follow-up, 5.5 years after the surgery, the patient did not complain of any pain during rest or activity. He had painless motion with persisting abduction and internal rotation reduction. Harris hip score (HHS) improved from preoperative 62 to 92 points at most recent follow-up. Treatment protocol was discussed in relation to the literature regarding this clinical topic.

A relationship between degree of windswept hip deformity and difficulty assisting in diaper change.

A relationship between degree of windswept hip deformity and difficulty assisting in diaper change.

Clinical evaluation of the Asian proximal femur intramedullary nail antirotation system (PFNA-II) for treatment of intertrochanteric fractures.

BackgroundThe preferred treatment of intertrochanteric fractures in aged patients is controversial. The purpose of the present study was to evaluate the outcomes of the Asian proximal femur intramedullary nail antirotation system (PFNA-II) for stabilization of such fractures.MethodsThe PFNA-II was used to treat intertrochanteric fractures in 163 elderly patients from March 2010 to March 2013. The patients comprised 69 men and 94 women with a mean age of 74.7 ± 13.0 years. All fractures were classified by the Orthopaedic Trauma Association classification system; 53, 83, and 27 fractures were classified as 31A1, 31A2, and 31A3, respectively. We statistically evaluated the intraoperative blood loss, operation time, incision length, X-ray exposure time, and postoperative outcomes. Patients were followed up for a mean of 15.2 months (range, 10–24 months). Functional outcomes were assessed according to the Harris hip scoring system.ResultsStatistical analysis revealed an average operation time of 45.7 min (range, 35–110 min), average intraoperative blood loss of 115.2 mL (range, 65–430 mL), X-ray exposure time of 2.7 ± 1.4 s (range, 2–6 s), and total incision length of 6.5 ± 2.2 cm (range, 5.5–13.0 cm). Patients were followed up for a mean of 14.5 months (range, 10–24 months). The neck shaft angle was 134° ±15° (range, 115°–150°), and the fracture healing time was 14.0 ± 2.5 weeks (range, 11–19 weeks). The Harris hip score was 85.6 ± 17.5 points (range, 65–100 points) and included 41 excellent cases (25.15%), 92 good cases (56.44%), 26 moderate cases (15.95%), and 4 poor cases (2.45%) for a positive outcome rate of 81.60%. There were no varus hip deformities, screw cutouts, or femoral shaft fractures. Fourteen patients had thigh pain (9.82%), and five had inner thigh pain (3.07%); seven had more severe pain that was improved by physical therapy.ConclusionPFNA-II has the advantages of a simple operation, few complications, and clinical efficacy for the treatment of intertrochanteric fractures. However, evaluation of its long-term efficacy and risk of other complications requires a large-sample, multicenter observational study.

Outcomes of dual-mobility acetabular cup for instability in primary and revision total hip arthroplasty.

BackgroundThe concept of a dual-mobility hip socket involves the standard femoral head component encased in a larger polyethylene liner, which in turn articulates inside a metal shell implanted in the native acetabulum. The aim of this study was to assess outcomes from using a Serf Novae® Dual Mobility Acetabular cup (Orthodynamics Ltd, Gloucestershire, UK) to address the problem of instability in primary and revision total hip arthroplasty (THA).Materials and methodsA retrospective review was carried out of all hip arthroplasties performed in a District General Hospital utilising the dual-mobility socket from January 2007 to December 2012. Clinical and radiological outcomes were analysed for 44 hips in 41 patients, comprising 20 primary and 24 revision THA. The average age of the study group was 70.8 years (range 56–84 years) for primary and 76.4 years (range 56–89 years) for revision arthroplasty. Among the primary THA, always performed for hip osteoarthritis or in presence of osteoarthritic changes, the reasons to choose a dual mobility cup were central nervous system problems such as Parkinson’s disease, stroke, dementia (10), hip fracture (5), failed hip fracture fixation (2), severe fixed hip deformity (2) and diffuse peripheral neuropathy (1). The indications for revisions were recurrent dislocation (17), aseptic loosening with abductor deficiency (4), failed hemiarthroplasty with abductor deficiency (2) and neglected dislocation (1).ResultsAt a mean follow-up of 22 months (range 6–63 months), none of the hips had any dislocation, instability or infection and no further surgical intervention was required. Radiological assessment showed that one uncemented socket in a revision arthroplasty performed for recurrent dislocation had changed position, but was stable in the new position. The patient did not have complications from this and did not need any surgical intervention.ConclusionsEven though postoperative hip stability depends on several factors other than design-related ones, our study shows promising early results for reducing the risk of instability in this challenging group of patients undergoing primary and revision hip arthroplasty.Level of evidenceIV.

Restoration of length of the femur in patients with consequences of epiphyseal osteomyelitis by means of intramedullary distraction according to Bliskunov

Epiphyseal osteomyelitis leads to such severe orthopaedic pathology as destructive hip dislocation, deformity, shortening, contracture, and osteoarthritis. Traditional method of eliminating unequal limb length is extrafocal ostheosyntesis. Objective: to evaluate outcomes in patients with hip shortening after epiphyseal osteomyelitis using intramedullary distraction. Methods: surgeries were performed in 26 patients, shortening of the femur was (7,0 ± 0,5) cm. Surgical technology of implantation of distraction apparatus' consisted of several phases: mounting of the conductor device, reboring of the medullary canal for the distractor, subtrochanteric osteotomy, implantation of the distraction device and its blocking, implantation of the telescopic actuator and the pelvic node to the wing of ilium. Distraction velocity was (1,0 ± 0,2) mm per day. Results: close-in outcomes were examined in 26 patients, and long-term outcomes in 23 ones. Good results obtained in 22 (95.7 %) patients, and satisfactory results in 1 (4.3 %) one. Any infectious complications were not observed. The devices implanted make it possible to apply methods of rehabilitation treatment on early stages during distraction and fixation. Conclusion: intramedullary distraction is an effective method for surgical correction of anatomic shortening of the hip after epiphyseal osteomyelitis.

Congenital Hip Deformity Morbidity in Children of Russia Based on Official Statistic Data 2011-2013

Congenital hip deformity morbidity in children was studied on the basis of official statistic data in the period 2011-2013. It was detected that total and primary morbidity was characterized by wide ranging values with significant year after year changes, great value discrepancy between urban and rural population. For early diagnosis and treatment of pathology the elaboration and application of screening program for detection of pathologic changes in the hip during first months of life, the standards for treatment of patients with congenital hip deformity and protocols for management of patients depending on severity of pathological changes were proposed.

Congenital Hip Deformity Morbidity in Children of Russia Based on Official Statistic Data 2011-2013

Congenital hip deformity morbidity in children was studied on the basis of official statistic data in the period 2011-2013. It was detected that total and primary morbidity was characterized by wide ranging values with significant year after year changes, great value discrepancy between urban and rural population. For early diagnosis and treatment of pathology the elaboration and application of screening program for detection of pathologic changes in the hip during first months of life, the standards for treatment of patients with congenital hip deformity and protocols for management of patients depending on severity of pathological changes were proposed.

Reliability of indices measured on infant hip MRI at time of spica cast application for dysplasia.

Infants with persistent developmental dysplasia of the hip (DDH) after harness treatment may be treated by operative reduction and spica casting, with post-reduction hip alignment assessed by magnetic resonance imaging (MRI), which can demonstrate three-dimensional hip geometry. This may provide valuable information regarding prognosis and adequacy of management, but such scans are difficult to assess due to limited spatial resolution and artefacts caused by patient motion. This may account for the limited success in correlating MRI findings to clinical outcomes to date. As a first step to improving these results we tested whether MRI indices of hip deformity and quality of femoral head reduction could be reliably measured. We retrospectively studied children with DDH, post-spica-cast MRI, and radiographic follow-up. We measured MRI indices adapted from other reports using computed tomography (CT) and MRI, and added new indices. Inter-observer reliability and inter-index correlations were evaluated and indices adapted during the process. We observed 55 dysplastic hips in 41 infants. Despite difficulties inherent to infant hip MRI, several indices were measured with substantial agreement (kappa up to 0.88, intra-class correlation ICC up to 0.91), with highly significant (p<0.01) correlation with each other (up to r = 0.72). Reliable indices included coronal acetabular angle, pulvinar fat-pad thickness, presence of a barrier to reduction, and grades of subluxation and dysplasia. Indices on MRI scan post hip spica cast placement can be measured reliably, assessing acetabular geometry, degree of hip reduction and barriers to reduction.

Complications of total hip replacement.

To determine the factors causing complications in unilateral total hip replacement. Analytical study. The Aga Khan University Hospital, Karachi, between 2000 and 2010. During the study period, 199 patients underwent elective unilateral total hip replacement at the Aga Khan University Hospital. Patients were divided into two groups on the basis of postoperative complications within 30 days of surgery. Significant factors at 5% significance level on univariate analysis were further analyzed by multivariate logistic regression. Postoperative complications occurred in 39 patients (19.6%); dislocation being most common in 13 patients (6.5%), followed by wound infection in four (2%), all of these patients required intervention. Other minor complications which were managed conservatively included wound infection (2.5%), urinary tract infection (2.5%), dislocation (1%), pleural effusion and pneumonia (2%), deep venous thrombosis (0.5%) and myocardial infarction (0.5%). On univariate analysis, patients with ASA III and IV, peri-operative blood transfusion, pre-operative hip deformity and post-operative bisphosphonate use were significantly associated with complications. On multi-variate analysis, adjusted odd's ratio for perioperative transfusion (3; 95% CI: 1.17-7.7) and hip deformity (3.2, 95% CI: 1.4-3.4) was found statistically significant. Pre-operative hip deformity and perioperative blood transfusion significantly influence the rates of complication after unilateral THR.

Nonoperative Management of Acetabular Labral Tear in a Skeletally Immature Figure Skater

Acetabular labral tear is an uncommon cause of hip pain in the skeletally immature athlete. Treatment outcomes have mostly been described in the surgical literature. We present a case report of a premenarchal 12-year-old figure skater who was diagnosed with an isolated acetabular labral tear without hip deformity. With nonoperative treatment, she was able to return to pain-free competitive figure skating 4 months after her onset of symptoms. Our findings suggest that acetabular labral tears in the skeletally immature athlete can respond to a trial of nonoperative management.

Open Surgical Treatment of Femoroacetabular Impingement in Adolescent Athletes

The surgical dislocation of the hip (SDH) approach has gained popularity in the treatment of femoroacetabular impingement (FAI) secondary to pediatric hip disorders. However, it has been suggested that SDH may preclude a return to previous levels of function in athletes. The purpose of this study was (1) to determine the level of activity and pain in young athletes before and after open hip surgery through an SDH approach for the treatment of FAI; (2) to investigate how clinical improvement correlates with physical activity; (3) to determine whether articular cartilage injury and the complexity of surgical procedures are associated with improvement in activity level and pain. SDH was utilized in 29 young athletes treated for symptomatic FAI (20 males 9 females, age range 12.7 to 20.7 years (mean age, 17 y)). Evaluation included sport(s) played, University of California Los Angeles (UCLA) physical activity level, and clinical outcome in terms of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-Pain scores. Intraoperative articular cartilage status and anteroposterior pelvic and lateral hip radiographs were assessed. All patients had regularly participated in one or more of 13 distinct sports. The median UCLA score increased with marginal significance (P=0.057) after surgery. Change in the level of pain from preoperatively to postoperatively, as measured by the WOMAC-Pain subscale, was found to be statistically significant (P=0.0024). A statistically significant correlation between changes in UCLA and WOMAC was estimated (ρ=-0.61, P≤0.001). No statistically significant correlation was found between change in UCLA and the addition of a second procedure other than femoral head-neck osteochondroplasty. Finally, no statistically significant correlation was found between severity of cartilage injury and change in UCLA or WOMAC scores. The femoral α-angle improved an average of 22.7 degrees (P<0.001) after surgery. Pain relief and maintenance or improvement in activity level may be achieved with open FAI surgery through an SDH approach in young athletes. Although this approach is more invasive than hip arthroscopy, it should be considered in the management of adolescents with FAI and complex hip deformities associated with pediatric disorders such as slipped capital femoral epiphysis and Perthes disease. Level IV-case series; retrospective.

The T-line as an intraoperative landmark for reproducing the native femoral anteversion during hip arthroplasty

Three-dimensional computed tomographic (CT)-based preoperative planning for total hip arthroplasty (THA) enabled us to evaluate the cut surface of the femoral neck osteotomy. When we planned the stem placement in 20° of anteversion, we noticed that the line connecting the trochanteric fossa and the middle of the medial cortex of the femoral neck (T line) was coincident with the component torsion in many cases. We attempted to evaluate the accuracy of the T line for reproducing the native femoral anteversion during THA comparing it with the midcortical line, the reference guide previously reported by Suh. The institutional review board allowed a retrospective review of CT images of 100 normal hip joints. We performed virtual THA using the non-anatomic straight stem at three different cutting heights of 5, 10, or 15 mm above the lesser trochanter. The anteversion of the stem implanted parallel to the T line or midcortical line was measured. The mean difference of the stem anteversion using the T line and the native femoral anteversion was -0.77º (95 % CI: -1.92º to 0.38º), 0.69º (95 % CI: -0.42º to 1.79º) and 3.38º (95 % CI: 2.29º-4.46º) at cutting heights of 5, 10 and 15 mm, respectively. Using the midcortical line, stems tended to retroversion. Aligning the stem parallel to the T line on the cut surface provides a good reproduction of the femoral anteversion. The T line can be an useful intraoperative reference guide for the anteversion of the femoral component in THA for patients without severe hip deformity.