The aim of this study was investigate the relationship between version and torsional abnormalities of the acetabulum, femur and tibia in patients with symptomatic FAI.
A systematic review was performed according to PRISMA guidelines using the EMBASE, MEDLINE, PubMed and Cochrane databases. Original research articles evaluating the described version and torsional parameters in FAI were included. The MINORS criteria were used to appraise study quality and risk of bias. Mean version and torsion values were displayed using forest plots and the estimated proportion of hips displaying abnormalities in version/torsion were calculated.
A total of 1206 articles were identified from the initial search, with 43 articles, involving 8861 hips, meeting the inclusion criteria. All studies evaluating femoral or acetabular version in FAI reported ‘normal’ mean version values (10–25 °). However, distribution analysis revealed that an estimated 31% and 51% of patients with FAI displayed abnormal central acetabular and femoral version, respectively.
Up to 51% of patients presenting with symptomatic FAI show an abnormal femoral version, whilst up to 31% demonstrate abnormal acetabular version. This high percentage of version abnormalities highlights the importance of evaluating these parameters routinely during assessment of patients with FAI, to guide clinical decision-making.
Level of evidence
Femoroacetabular impingement (FAI) is characterised by an abnormal contact between the acetabulum and the femur, limiting range of motion and leading to hip pain and disability. Ganz et al. proposed that FAI may lead to the development of osteoarthritis of the hip joint . FAI can be classified into three categories according to the specific pathomorphology involved. Cam type FAI represents asphericity of the femoral head due to abnormal morphology at the head neck junction . Pincer-type FAI on the other hand, occurs due to over-coverage of the femoral head by the acetabulum and premature contact between the acetabulum and femoral neck . Some patients may present with both of these abnormalities, known as mixed-typed FAI .
Increasingly, there is an interest in the role of acetabular and femoral version and tibial torsion in FAI. Ng et al. reported a significantly higher mean femoral version in those with symptomatic cam FAI as compared with healthy controls . A study of 200 hips by Shin et al. demonstrated a significant correlation between combined index of acetabular and femoral version with both internal and external rotation of the hip . Lerch et al. found that 68% of 538 hips presenting with FAI or dysplasia showed abnormal femoral and/or acetabular version . A more recent study by Lerch et al. also found abnormal tibial torsion in 42% of patients with FAI and dysplasia .
Version abnormalities have gained interest because they may potentially influence the outcome following arthroscopic intervention for FAI . Therefore, it is important to understand these abnormalities to ensure optimal decision-making. To the best of our knowledge, there are currently no systematic reviews characterising version and torsional deformities of the acetabulum, femur and tibia in FAI. The aim of this study, therefore, was to perform a systematic review investigating the relationship between version and torsional abnormalities of the acetabulum, femur and tibia in patients with primary FAI. Our hypothesis was that patients with symptomatic FAI displayed significant version abnormalities of the acetabulum or femur and tibial torsion.
Materials and methods
A systematic electronic search was performed by two reviewers independently using PubMed, OVID MEDLINE(R) (1946 to December 2020), Cochrane Library databases and OVID EMBASE (1974 to December 2020). Manual reference list checking of retrieved review articles was also conducted. Relevant terms such as ‘hip’, ‘pain’, ‘disorder’, ‘femoral version’, ‘femoral torsion’, ‘acetabular version’ and 'tibial torsion' were combined with Boolean operators (‘and’, ‘or’) to produce final searches. The systematic review title was registered in the Open Science Framework. All aspects of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed whilst performing the systematic review . The individual study inclusion and exclusion criteria were established a priori. Original research studies (observational, cohort, randomised control trials) evaluating femoral version, acetabular version or tibial torsion in Human patients with FAI were included. No specific control group was required for inclusion. Abstracts, review articles, commentaries and case reports were excluded. No language or date of publication criteria were imposed.
Studies were imported into the Mendeley reference management software (© Mendeley Ltd, London, UK) to aid screening and selection.
Two reviewers independently (MZA and HDM) performed a two-stage title/abstract and full-text screening to identify eligible studies. Differences in opinion at any stage were resolved by discussion. A third, senior reviewer (VK) was consulted if there was a discrepancy and when no consensus was reached.
An extraction spreadsheet containing the following headings was created in Microsoft Excel: (1) Author (2) Year of Publication (3) Title (4) Country of Origin (5) Aims (6) Participants including key demographics (7) Key findings (including mean acetabular and femoral version or tibial torsion). This spreadsheet was used by two authors (MZA and HDM) independently, to extract information from the first 10 studies. Discussion then took place to ascertain the suitability of the spreadsheet, following which it was decided to use the same spreadsheet to extract information from the remaining studies.
Results of the search and screening processes are displayed in the PRISMA flow diagram (Fig. 1) . Mean version values in the included studies, along with standard deviations are displayed in forest plots generated using R 4.0.0 software (R Foundation for Statistical Computing, Vienna, Austria). Acetabular version may be measured at a number of different axial planes along the cranio-caudal axis of the acetabulum . Central acetabular version was defined as the angle between a line connecting the anterior and posterior acetabular rim at the level of the centre of the femoral head and a sagittal line . Cranial acetabular version was defined as the measurement obtained when using any axial slice superior to the centre of the femoral head. Authors use a number of different positions when referring to cranial acetabular version and these are outlined (results, cranial version).
The normal range for femoral and central acetabular version of 10–25 ° originally proposed by Tönnis was used . Missing standard deviation values were imputed using the guidelines outlined by Weir et al. and where study data was reported across two or more groups, these were combined following the methodology of Higgins and Green [22, 61]. The percentage of patients with version < 10 ° and > 25 ° was calculated. This is based on the assumption that version values are normally distributed, which has been demonstrated in previous studies [30, 31]. A qualitative synthesis of studies not included in meta-analysis or forest plots is provided.
Risk of bias and quality of evidence
The Methodological Index for Non Randomized Studies (MINORS) criteria was used to assess the risk of bias and quality of all included studies . The MINORS criteria consists of a 12 item checklist, each item given a score of 0 (not reported), 1 (inadequately reported) or 2 (adequately reported) . The studies were scored against a maximum of 16 points for non-comparative studies and 24 points for comparative studies .
A total of 1206 studies were identified on the initial search and of these 43 articles involving 8861 hips finally met the inclusion criteria (Fig. 1). Results for the MINORS criteria are shown below (Table 1).
A total of 35 studies reported mean femoral version values in patients with various types of FAI. A forest plot displaying mean femoral version and 95% confidence intervals in these pathologies is displayed (Fig. 2). Majority (26/35, 74.2%) of the studies reported a mean femoral version value between 10 and 25 0.
Central acetabular version
A total of 23 included studies reported mean central acetabular version values in different subtypes of FAI. A forest plot displaying mean central acetabular version and 95% confidence intervals in these pathologies is displayed in Fig. 3. All but one study (22/23, 95.7%) reported a mean acetabular version values in the normal range between 10 and 25 0.
Cranial acetabular version
Cranial acetabular version in FAI was reported by a total of seven studies (Fig. 4). Techniques used to measure cranial version varied in the included studies (using an axial slice 5 mm distal to acetabular roof, measurement at 1 o’clock position or 1:30 o’clock position) [4, 21, 25, 30, 48, 49, 52]. Due to this heterogeneity, no further distribution analysis was performed using these values. Figure 4 shows a forest plot displaying mean cranial acetabular version and 95% confidence intervals in various types of FAI. A total of six studies reported mean cranial acetabular version values less than 10 ° but did not specify the FAI subtype.
Studies not included in forest plots
Some studies were not included in forest plots due to paucity of data from similar studies and hence a summary of the findings is given Table 4.
51% of hips in patients with symptomatic FAI displayed abnormal femoral version, whilst 31% showed an abnormal acetabular version are the main findings of our study. These figures are similar to those demonstrated by Lerch et al., which found an abnormal femoral version in 52% of patients with FAI or dysplasia and abnormal acetabular version in 30% of patients . The quality of studies included in this review is mixed, with the MINORS criteria revealing a number of studies show flaws in methodological rigour. Specifically, studies either fail to describe or do not use a consecutive enrolment design (question 5, Table 1). Furthermore, very few studies describe blinded evaluation of version parameters (question 8, Table 1). A significant proportion of included studies did not contain any control or comparison group. As such, it was not possible to evaluate questions 9–12 of the MINORS criteria.
Currently, there is no agreement on the ‘normal’ reference range values for femoral version, acetabular version and tibial torsion in patients with FAI. Thresholds for determining increased femoral version range from > 15 o to > 25 ° and decreased femoral version ranging from < 10 ° to < 0 ° [10, 12, 14, 26, 30, 59]. Similarly, authors have proposed various ranges for normal acetabular version including 10–25 ° and 13–20 o [30, 42]. Therefore, for the purpose of this review, the normal range for femoral and central acetabular version of 10–25 ° originally proposed by Tönnis was used .
Although the majority of included studies reported mean version values within ‘normal’ limits (Figs. 2 and 3), distribution analysis revealed that 31% of patients with FAI may have abnormal acetabular version < 10 ° or > 25 ° (Table 3) and up to 51% demonstrated abnormal femoral version < 10 ° or > 25 o (Table 2). More specifically, 42% had an excessive femoral retroversion < 10 °, whilst 19% had an abnormal acetabular version of < 10 °.
It remains to be seen whether these abnormalities represent a modifiable variable which may influence arthroscopic outcomes. Fabricant et al. found that although patients with femoral retroversion < 5 ° saw clinically important improvements in outcome following arthroscopic surgery, the outcomes were inferior to those with normal or increased femoral version . On the other hand, Ferro et al., Lall et al., and Jackson et al., demonstrate no significant difference in outcomes in relation to femoral version [14, 23, 27]. Buller et al. reported that a complementary relationship existed between femoral and acetabular version whereby excessive acetabular retroversion may be compensated for by an increase in femoral anteversion, increasing impingement free range of motion . Therefore, potentially in the above three studies, the influence of femoral version on outcomes may have been blunted by a compensatory acetabular version which was not specifically looked at. Furthermore, the study by Shin et al. found that the effect of a combined index of femoral and acetabular version was greater than that of femoral version alone . Chaharbakshi et al. found patients with excessive femoral anteversion and borderline dysplasia showed inferior arthroscopic outcomes when compared to a matched control group .
Assessment of femoral version and tibial torsion is possible by clinical examination but not for acetabular version. It is therefore crucial that pre-operative imaging, such as a CT scan, is performed for patients with FAI, to gain a better understanding of the underlying deformities. Correction of any version abnormalities identified, through periacetabular or femoral osteotomy, together with cam or pincer excision, may potentially yield better outcomes in these patients. In addition, potentially some patients with significant version abnormality may require only correction of version abnormalities, without the need for arthroscopic intervention. Lerch et al. described abnormal femoral version (< 10 °, > 25 °) in over 74% of patients with clinical symptoms, but without any radiographic features of FAI . Therefore, version abnormalities may indeed be the cause of hip pain in those presenting to the young adult hip clinic.
Studies have suggested specific differences in version may play a role in different subtypes of FAI [17, 30]. For example, a significantly lower femoral version of 15 ° has been demonstrated in patients with symptomatic Cam-FAI compared to asymptomatic controls (22°) . Cam deformities have also been found in a considerable proportion of asymptomatic individuals [18, 57]. Furthermore, Gramamtopoulos et al. suggested that acetabular version may be one factor leading to the development of symptoms in patients with a cam deformity, showing a significantly higher acetabular version of 17 ° in symptomatic cam patients, compared to 11 ° in asymptomatic cam controls .
Our systematic review included studies which used both CT and MRI based measurement methods in the analysis. Although these two techniques have been found to show similar agreement compared to consecutive CT or MRI measurements, differences in version values gained using these techniques exist and there is a possibility that may be exacerbated when summarising studies . Another factor to be noted is the failure of a number of studies to separate femoral/acetabular version measurements according to the FAI subtype. This meant we were unable to qualify the type of FAI where the version abnormality was noted.
It is important to note that even those studies identifying significant differences in version between patients with FAI and controls or between different types of FAI, reported mean version values in the patients within a normal range [17, 30, 38]. In such situation, there is a need to evaluate whether there are other potential causes for FAI such as extra-articular impingement or spinopelvic parameters [17, 34, 45]. Clinicians should take a more holistic approach and guide their treatment approach by considering how these measured parameters may collectively play a role in a patient’s symptoms. One way in which this has been done recently, is to combine femoral and acetabular version with the femoral neck-shaft angle, alpha angle and LCEA into a single value known as the ‘omega zone’. Bouma et al. found a significantly smaller omega zone in patients with cam-type FAI compared to controls . We would, however, suggest that, although the use of such combined parameters can help quantify the rotational interaction between the femur and acetabulum, combining parameters may prevent clinicians from recognising and correcting important differences in individual parameters.
There is potentially a relationship between tibial torsion and femoral version; however, only one of the included studies reported tibial torsion values in patients with FAI . Future research into FAI should evaluate tibial torsion in patients with FAI, to elucidate any potential role that this parameter may play in the management of FAI.
This systematic review was conducted in the rigorous manner outlined by PRISMA. However certain limitations must also be acknowledged. First, when estimating the percentage of patients showing abnormalities in femoral and acetabular version, every cohort was assumed to show a normal distribution of these values. Although large studies have previously shown a normal distribution, this may not be true for all study cohorts, particularly those of smaller size [30, 31]. Furthermore, different measurement methods, including CT and MRI were used in included studies. Although studies have shown a high degree of consistency between these measurement methods, differences may still exist [20, 32]. Unfortunately, it was not possible to perform a meta-analysis investigating differences in femoral/acetabular version between FAI subtypes due to the inherently large degree of heterogeneity.
Up to 51% of patients presenting with symptomatic FAI show an abnormal femoral version, whilst up to 31% demonstrate abnormal acetabular version. These abnormalities may represent a modifiable variable with an influence on arthroscopic outcomes. As such, consideration of these morphological parameters in the assessment and management of patients with FAI is a crucial step in the development of a holistic arthroscopic approach, taking into account both pathomorphology and patho-alignment.
Audenaert EA, Peeters I, Vigneron L, Baelde N, Pattyn C (2012) Hip morphological characteristics and range of internal rotation in femoroacetabular impingement. Am J Sports Med 40:1329–1336
Bedi A, Dolan M, Hetsroni I, Magennis E, Lipman J, Buly R, Kelly BT (2011) Surgical treatment of femoroacetabular impingement improves hip kinematics: a computer-assisted model. Am J Sports Med 39(Suppl):43S-S49
Bedi A, Dolan M, Magennis E, Lipman J, Buly R, Kelly BT (2012) Computer-assisted modeling of osseous impingement and resection in femoroacetabular impingement. Arthroscopy 28:204–210
Bedi A, Thompson M, Uliana C, Magennis E, Kelly BT (2013) Assessment of range of motion and contact zones with commonly performed physical exam manoeuvers for femoroacetabular impingement (FAI): what do these tests mean? Hip Int 23:S27–S34
Bouma HW, Hogervorst T, Audenaert E, Krekel P, van Kampen PM (2015) Can combining femoral and acetabular morphology parameters improve the characterization of femoroacetabular impingement? Clin Orthop Relat Res 473:1396–1403
Buller LT, Rosneck J, Monaco FM, Butler R, Smith T, Barsoum WK (2012) Relationship between proximal femoral and acetabular alignment in normal hip joints using 3-dimensional computed tomography. Am J Sports Med 40:367–375
Chaharbakhshi EO, Hartigan DE, Perets I, Domb BG (2019) Is Hip arthroscopy effective in patients with combined excessive femoral anteversion and borderline dysplasia? A match-controlled study. Am J Sports Med 47:123–130
Cobb J, Logishetty K, Davda K, Iranpour F (2010) Cams and pincer impingement are distinct, not mixed: the acetabular pathomorphology of femoroacetabular impingement. Clin Orthop Relat Res 468:2143–2151
Dandachli W, Islam SU, Liu M, Richards R, Hall-Craggs M, Witt J (2009) Three-dimensional CT analysis to determine acetabular retroversion and the implications for the management of femoro-acetabular impingement. J Bone Joint Surg Br 91:1031–1036
Dolan MM, Heyworth BE, Bedi A, Duke G, Kelly BT (2011) CT reveals a high incidence of osseous abnormalities in hips with labral tears. Clin Orthop Relat Res 469:831–838
Ejnisman L, Philippon MJ, Lertwanich P, Pennock AT, Herzog MM, Briggs KK, Ho CP (2013) Relationship between femoral anteversion and findings in hips with femoroacetabular impingement. Orthopedics 36:e293-300
Fabricant PD, Bedi A, De La Torre K, Kelly BT (2012) Clinical outcomes after arthroscopic psoas lengthening: the effect of femoral version. Arthroscopy 28:965–971
Fabricant PD, Fields KG, Taylor SA, Magennis E, Bedi A, Kelly BT (2015) The effect of femoral and acetabular version on clinical outcomes after arthroscopic femoroacetabular impingement surgery. J Bone Joint Surg Am 7:537–543
Ferro FP, Ho CP, Briggs KK, Philippon MJ (2015) Patient-centered outcomes after hip arthroscopy for femoroacetabular impingement and labral tears are not different in patients with normal, high, or low femoral version. Arthroscopy 31:454–459
Fritz B, Bensler S, Leunig M, Zingg PO, Pfirrmann CWA, Sutter R (2018) Mri assessment of supra- and infratrochanteric femoral torsion: Association with femoroacetabular impingement and hip dysplasia. Am J Roentgenol 211:155–161
Ganz R, Parvizi J, Beck M, Leunig M, Nötzli H, Siebenrock KA (2003) Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res 417:112–120
Grammatopoulos G, Speirs AD, Ng KCG, Riviere C, Rakhra KS, Lamontagne M, Beaule PE (2018) Acetabular and spino-pelvic morphologies are different in subjects with symptomatic cam femoro-acetabular impingement. J Orthop Res 36:1840–1848
Han J, Won S-H, Kim J-T, Hahn M-H, Won Y-Y (2018) Prevalence of cam deformity with associated femoroacetabular impingement syndrome in hip joint computed tomography of asymptomatic adults. Hip Pelvis 30:5–11
Hellman MD, Haughom BD, Brown NM, Fillingham YA, Philippon MJ, Nho SJ (2017) Femoroacetabular impingement and pelvic incidence: radiographic comparison to an asymptomatic control. Arthroscopy 33:545–550
Hesham K, Carry PM, Freese K, Kestel L, Stewart JR, Delavan JA, Novais EN (2017) Measurement of femoral version by MRI is as reliable and reproducible as CT in children and adolescents with hip disorders. J Pediatr Orthop 37:557–562
Hetsroni I, Dela Torre K, Duke G, Lyman S, Kelly BT (2013) Sex differences of hip morphology in young adults with hip pain and labral tears. Arthroscopy 29:54–63
Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (2011) Cochrane handbook for systematic reviews of interventions. Wiley, Chichester
Jackson TJ, Lindner D, El-Bitar YF, Domb BG (2015) Effect of femoral anteversion on clinical outcomes after hip arthroscopy. Arthroscopy 31:35–41
Kelly BT, Bedi A, Robertson CM, Dela Torre K, Giveans MR, Larson CM (2012) Alterations in internal rotation and alpha angles are associated with arthroscopic cam decompression in the hip. Am J Sports Med 40:1107–1112
Klingenstein GG, Zbeda RM, Bedi A, Magennis E, Kelly BT (2013) Prevalence and preoperative demographic and radiographic predictors of bilateral femoroacetabular impingement. Am J Sports Med 41:762–768
Koerner JD, Patel NM, Yoon RS, Sirkin MS, Reilly MC, Liporace FA (2013) Femoral version of the general population. J Orthop Trauma 6:308–311
Lall AC, Battaglia MR, Maldonado DR, Perets I, Laseter JR, Go CC, Domb BG (2019) Does femoral retroversion adversely affect outcomes after hip arthroscopy for femoroacetabular impingement syndrome? A midterm analysis. Arthroscopy 35:3035–3046
Lerch TD, Boschung A, Todorski IAS, Steppacher SD, Schmaranzer F, Zheng G, Ryan MK, Siebenrock KA, Tannast M (2019) Femoroacetabular impingement patients with decreased femoral version have different impingement locations and intra- and extraarticular anterior subspine FAI on 3D-CT-based impingement simulation: implications for hip arthroscopy. Am J Sports Med 47:3120–3132
Lerch TD, Liechti EF, Todorski IAS, Schmaranzer F, Steppacher SD, Siebenrock KA, Tannast M, Klenke FM (2020) Prevalence of combined abnormalities of tibial and femoral torsion in patients with symptomatic hip dysplasia and femoroacetabular impingement. J Bone Joint Surg Br 102-B:1636–1645
Lerch TD, Todorski IASS, Steppacher SD, Schmaranzer F, Werlen SF, Siebenrock KA, Tannast M (2018) Prevalence of femoral and acetabular version abnormalities in patients with symptomatic hip disease: a controlled study of 538 hips. Am J Sports Med 46:122–134
Litrenta JM, Domb BG (2018) Normative data on femoral version. J Hip Preserv Surg 5:410–424
Mao C, Liang Y, Ding C, Guo L, Wang Y, Zeng Q, Wang G (2016) The consistency between measurements of the femoral neck anteversion angle in DDH on three-dimensional CT and MRI. Acta radiol 6:716–720
Marostica AD, Pizzolatti ALA, Adam GP, Codonho D, Canella RP, Ganev GG (2019) Is femoral version associated with changes in hip muscle strength in females with symptomatic femoroacetabular impingement? Rev Bras Ortop 54:422–427
Mascarenhas VV, Rego P, Dantas P, Caetano AP, Jans L, Sutter R, Marques RM, Ayeni OR, Consciência JG (2018) Can we discriminate symptomatic hip patients from asymptomatic volunteers based on anatomic predictors? A 3-dimensional magnetic resonance study on cam, pincer, and spinopelvic parameters. Am J Sports Med 46:3097–3110
Masjedi M, Nightingale CL, Azimi DY, Cobb JP (2013) The three-dimensional relationship between acetabular rim morphology and the severity of femoral cam lesions. J Bone Joint Surg Br 95-B:314–319
Milone MT, Bedi A, Poultsides L, Magennis E, Byrd JWT, Larson CM, Kelly BT (2013) Novel CT-based three-dimensional software improves the characterization of cam morphology hip. Clin Orthop Relat Res 471:2484–2491
Moher D, Liberati A, Tetzlaff J, Altman DG, Altman D, Antes G, Atkins D, Barbour V, Barrowman N, Berlin JA, Clark J, Clarke M, Cook D, D’Amico R, Deeks JJ, Devereaux PJ, Dickersin K, Egger M, Ernst E, Gøtzsche PC, Grimshaw J, Guyatt G, Higgins J, Ioannidis JPA, Kleijnen J, Lang T, Magrini N, McNamee D, Moja L, Mulrow C, Napoli M, Oxman A, Pham B, Rennie D, Sampson M, Schulz KF, Shekelle PG, Tovey D, Tugwell P (2009) Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 6:e1000097. https://doi.org/10.1371/journal.pmed.1000097
Ng KCG, Lamontagne M, Adamczyk AP, Rahkra KS, Beaulé PE (2015) Patient-specific anatomical and functional parameters provide new insights into the pathomechanism of cam FAI. Clin Orthop Relat Res 473:1289–1296
Ng KCG, Lamontagne M, Beaule PE (2016) Differences in anatomical parameters between the affected and unaffected hip in patients with bilateral cam-type deformities. Clin Biomech 33:13–19
Ng KCG, Lamontagne M, Jeffers JRT, Grammatopoulos G, Beaulé PE (2018) Anatomic predictors of sagittal hip and pelvic motions in patients with a cam deformity. Am J Sports Med 46:1331–1342
Ng KCG, Lamontagne M, Labrosse MR, Beaulé PE (2018) Comparison of anatomical parameters of cam femoroacetabular impingement to evaluate hip joint models segmented from CT data. Comput Methods Biomech Biomed Eng Imaging Vis 6:293–302
Nitschke A, Petersen B, Lambert JR, Glueck DH, Jesse MK, Strickland C, Mei-Dan O (2016) Validation of neck axis distance as a radiographic measure for acetabular anteversion. J hip Preserv Surg 3:72–78
Perreira AC, Hunter JC, Laird T, Jamali AA (2011) Multilevel measurement of acetabular version using 3-D CT-generated models: implications for hip preservation surgery. Clin Orthop Relat Res 469:552–561
de Pina CF, Figueiredo F, Todorski I, Toledo de Araujo LC, Locks R, Aguiar DP (2020) Femoral torsion evaluation by computed tomography in a young Brazilian population with hip pain and femoroacetabular impingement. J Orthop 18:32–35
Ricciardi BF, Fabricant PD, Fields KG, Poultsides L, Zaltz I, Sink EL (2015) What are the demographic and radiographic characteristics of patients with symptomatic extraarticular femoroacetabular impingement? Clin Orthop Relat Res 473:1299–1308
Ross JR, Bedi A, Stone RM, Sibilsky Enselman E, Kelly BT, Larson CM (2015) Characterization of symptomatic hip impingement in butterfly ice hockey goalies. Arthroscopy 31:635–642
Ross JR, Bedi A, Stone RM, Sibilsky Enselman E, Leunig M, Kelly BT, Larson CM (2014) Intraoperative fluoroscopic imaging to treat cam deformities: correlation with 3-dimensional computed tomography. Am J Sports Med 42:1370–1376
Ross JR, Khan M, Noonan BC, Larson CM, Kelly BT, Bedi A (2018) Characterization and correction of symptomatic hip impingement in American football linemen. HSS J 14:128–133
Ross JR, Nepple JJ, Philippon MJ, Kelly BT, Larson CM, Bedi A (2014) Effect of changes in pelvic tilt on range of motion to impingement and radiographic parameters of acetabular morphologic characteristics. Am J Sports Med 42:2402–2409
Ross JR, Tannenbaum EP, Nepple JJ, Kelly BT, Larson CM, Bedi A (2015) Functional acetabular orientation varies between supine and standing radiographs: implications for treatment of femoroacetabular impingement. Clin Orthop Relat Res 473:1267–1273
Schaeffeler C, Eiber M, Holzapfel K, Gollwitzer H, Rummeny EJ, Woertler K (2012) The epiphyseal torsion angle in MR arthrography of the hip: diagnostic utility in patients with femoroacetabular impingement syndrome. Am J Roentgenol 198:W237-243
Shin J, Adeyemi TF, Hobson T, Peters CL, Maak TG (2020) The bipolar hip: how acetabular and femoral pathomorphology affect hip motion in femoral acetabular impingement syndrome. Arthroscopy 36:1864–1871
Slim K, Nini E, Forestier D, Kwiatkowski F, Panis Y, Chipponi J (2003) Methodological index for non-randomized studies (MINORS): development and validation of a new instrument. ANZ J Surg 73:712–716
Sutter R, Dietrich TJ, Zingg PO, Pfirrmann CWA (2012) Femoral antetorsion: comparing asymptomatic volunteers and patients with femoroacetabular impingement. Radiology 263:475–483
Tannast M, Kubiak-Langer M, Langlotz F, Puls M, Murphy SB, Siebenrock KA (2007) Noninvasive three-dimensional assessment of femoroacetabular impingement. J Orthop Res 25:122–131
Tannast M, Siebenrock KA, Anderson SE (2007) Femoroacetabular impingement: radiographic diagnosis—what the radiologist should know. Am J Roentgenol 188:1540–1552
Thier S, Gerisch D, Weiss C, Fickert S, Brunner A (2017) Prevalence of cam and pincer deformities in the X-rays of asymptomatic individuals. Biomed Res Int 2017:8562329. https://doi.org/10.1155/2017/8562329
Tibor LM, Liebert G, Sutter R, Impellizzeri FM, Leunig M (2013) Two or more impingement and/or instability deformities are often present in patients with hip pain. Clin Orthop Relat Res 471:3762–3773
Tönnis D, Heinecke A (1999) Acetabular and femoral anteversion: relationship with osteoarthritis of the hip. J Bone Joint Surg Am 81:1747–1770
Weinberg DS, Gebhart JJ, Liu RW, Salata MJ (2016) Radiographic signs of femoroacetabular impingement are associated with decreased pelvic incidence. Arthroscopy 32:806–813
Weir CJ, Butcher I, Assi V, Lewis SC, Murray GD, Langhorne P, Brady MC (2018) Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review. BMC Med Res Methodol 18:25. https://doi.org/10.1186/s12874-018-0483-0
Yanke AB, Khair MM, Stanley R, Walton D, Lee S, Bush-Joseph CA, Espinoza Orias A, Inoue N, Nho SJ (2015) Sex Differences in patients with CAM deformities with femoroacetabular impingement: 3-dimensional computed tomographic quantification. Arthroscopy 31:2301–2306
No funding for this project.
Conflict of interest
Mr. Khanduja is the Chair of the ESSKA Hip Arthroscopy Committee and the Educational Consultant to Smith & Nephew and Arthrex.
This article does not contain any studies with human participants or animals performed by any of the authors.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Arshad, Z., Maughan, H.D., Sunil Kumar, K.H. et al. Over one third of patients with symptomatic femoroacetabular impingement display femoral or acetabular version abnormalities. Knee Surg Sports Traumatol Arthrosc (2021). https://doi.org/10.1007/s00167-021-06643-3
- Femoroacetabular impingement
- Femoral version
- Acetabular version
- Tibial torsion