Hip dysplasia in the young adult

Transcription

1 Washington University School of Meicine Digital Open Access Publications 2016 Hip ysplasia in the young ault Luca Gala John C. Clohisy Paul E. Beaulé Follow this an aitional works at: This Open Access Publication is brought to you for free an open access by Digital It has been accepte for inclusion in Open Access Publications by an authorize aministrator of Digital For more information, please contact

2 63 COPYRIGHT Ó 2016 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED Current Concepts Review Hip Dysplasia in the Young Ault Luca Gala, MD, John C. Clohisy, MD, an Paul E. Beaulé, MD, FRCSC Investigation performe at the Division of Orthopaeic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canaa ä Hip ysplasia is a leaing precursor of osteoarthritis an is seen in 20% to 40% of patients with osteoarthritis of the hip. ä An increase in mechanical stress on the cartilage matrix with failure of the acetabular labrum represents the major pathomechanism of egeneration. ä Because the prevalence of associate femoral eformities is high (>50%), the structural anatomy of the ysplastic hip must be assesse in multiple planes using raiographs an, if neee, avance imaging moalities. ä Acetabular osteotomy (periacetabular an/or rotational) is the most commonly use proceure for the treatment of the majority of ysplastic hips in aults. ä Moern total hip replacement remains an excellent option for the more arthritic joints. Difficulties can arise from anatomical abnormalities an previous operations. Peer Review: This article was reviewe by the Eitor-in-Chief an one Deputy Eitor, an it unerwent bline review by two or more outsie experts. The Deputy Eitor reviewe each revision of the article, an it unerwent a final review by the Eitor-in-Chief prior to publication. Final corrections an clarifications occurre uring one or more exchanges between the author(s) an copyeitors. Descriptive Epiemiology Refinements in unerstaning the etiology of seconary osteoarthritis have highlighte evelopmental ysplasia of the hip (DDH) an femoroacetabular impingement as leaing precursors 1,2. Accoring to some estimates, DDH is involve in 20% to 40% of patients with osteoarthritis of the hip 3-5. Despite the wiesprea screening for hip ysplasia at birth an uring infancy, a substantial number of cases are not iagnose until aulthoo, with an estimate prevalence of 0.1% of the U.S. ault population 6,7. Female sex, primiparity, breech position, an family history are known risk factors for hip ysplasia The lack of early intervention resulting from elaye iagnosis can lea to early onset of hip osteoarthritis an subsequent total hip replacement, although mil acetabular ysplasia has a variable an mostly benign natural history Accoring to a stuy of 3620 subjects conucte by Gosvig et al. 15, the prevalence of ysplasia was 4.3% (fifty-eight of 1332) in men an 3.6% (eighty-two of 2288) in women. Jacobsen an Sonne-Holm 16, in a cross-sectional survey of 2232 women an 1336 men, foun a prevalence that range from 5.4% to 12.8%, epening on the raiographic inex applie. In both of these stuies, the patients were asymptomatic. It is generally acknowlege that if DDH is recognize early, surgical correction of the abnormal anatomy iminishes the risk of osteoarthritis 12,13. Pathomechanism an Natural History In patients with hip ysplasia, the typically shallow acetabulum leas to an increase in mechanical stress on the cartilage matrix, which can be beyon the physiologic level of tolerance 14. Dysplastic acetabuli are not only eficient in a single plane or imension but also are globally eficient both in shape an orientation, with the with remaining comparable with that of the nonysplastic acetabulum but with increase length an Disclosure: None of the authors receive payments or services, either irectly or inirectly (i.e., via his or her institution), from a thir party in support of any aspect of this work. One or more of the authors, or his or her institution, has ha a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomeical arena that coul be perceive to influence or have the potential to influence what is written in this work. Also, no author has ha any other relationships, or has engage in any other activities, that coul be perceive to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitte by authors are always provie with the online version of the article. J Bone Joint Surg Am. 2016;98:

3 64 ecrease epth. This leas not only to the classic anterior insufficiency but also, potentially, to lateral, posterior, or global eficiency 17. Even with mil hip ysplasia, the poor coverage of the femoral hea, the relative lateralization of the hip center of rotation, an the smaller contact area between the femoral hea an the ysplastic acetabulum can prouce an asymmetric concentration of force across the hip joint an seconary articular cartilage an labral amage The acetabular anomaly is usually accompanie by abnormalities of the proximal part of the femur, in which the femoral hea is usually small an often aspherical with increase anteversion an neck-shaft angle (valgus) 21. In a recent stuy, Henak et al. 22 emonstrate that, in patients with a ysplastic hip, the acetabular labrum plays a greater role as a loa-bearing structure an the labrum supporte substantially more loa than in normal hips. The natural history of DDH has been well evaluate in the literature 11-14,23-25 an has been note to lea to the evelopment of raiographic osteoarthritis in 25% to 50% of patients by a mean age of 50.3 years. More specifically, Wiberg 14, in his stuy about congenital subluxation of the hip, note that all of his patients with efinite subluxation showe evience of osteoarthritis by the age of fifty to sixty years. Murphy et al. 11 followe the contralateral hip in 286 patients who ha ha a total hip arthroplasty for osteoarthritis seconary to ysplasia an observe that no patient in whom the hip survive into the seventh ecae of life ha a lateral center-ege angle of <16, anacetabular inex of >15, or uncovering of the femoral hea of >31%. Cooperman et al. 26 followe thirty-two hips with a Wiberg angle of 20 for twenty-two years, an almost all patients ha osteoarthritis at the time of the final follow-up when they were a mean of sixty-five years ol. Moreover, early osteoarthritis appears to be more highly associate with anterior acetabular coverage eficiency than it is with lateral acetabular eficiency 27. Most recently, acetabular retroversion has also been observe in patients with DDH 28.Mastetal. 29 stuie the raiographs of 153 patients with DDH who were seen because of hip pain, to etermine the usual version of the socket. Retroversion of the hip socket was note in one in three hips. The same fining was highlighte by Li an Ganz 30, with a lower prevalence of one in six hips (Fig. 1). It is important to mention that classic acetabular ysplasia an acetabular retroversion represent two istinct acetabular pathomorphologies. Retroversion in DDH is now mostly consiere to represent posterior insufficiency an iffers from a nonysplastic retroverte acetabulum that may be associate with impingement 31,32. Clohisy et al. showe that proximal femoral eformities were present in 92.6% of the 108 hips treate for symptomatic acetabular ysplasia, with 48% of the hips having coxa valga (44%) or coxa vara (4%) 21. They also foun that femoral hea asphericity was present in 72% of the hips an reuce heaneck offset in 75%. They conclue that ientifying an treating these proximal femoral abnormalities may optimize joint congruency an therefore minimize seconary impingement after reorientation of the acetabulum. In ysplastic sockets, the acetabular labrum is often hypertrophic, probably in response to the increase loa experience by Fig. 1 Anteroposterior pelvic raiograph (left image) of a twenty-three-year-ol woman with three years of persistent pain in the right hip. The lateral center-ege angle was 21. Measurement of the femoral hea extrusion inex is shown on the left hip. The inverte (right) image shows the crossover sign.

4 65 TABLE I Summary of the Raiographic Measurements in the Assessment of Dysplasia* Anteroposterior Raiograph False-Profile Raiograph Lateral Raiograph Normal DDH LCEA of 25-35, Tönnis angle of 0-10, femoral neck-shaft angle of , an extrusion inex of <10% LCEA of <20, Tönnis angle of >10, valgus femoral neck-shaft angle of >135, varus femoral neck-shaft angle of <120, extrusion inex of >25%, fovea alta, an broken Shenton line ACEA of ACEA of <20 Spherical femoral hea (a angle of <50 ) 126 NA *LCEA = lateral center-ege angle (Wiberg), ACEA = anterior center-ege angle (Lequesne), an NA = not applicable. the front of the acetabulum to improve femoral hea coverage an maintain joint lubrication 33. This hypertrophic labrum can be remarkably effective at maintaining the mechanical equilibrium an preventing symptoms until aulthoo 34.Theamagelabrummay also act as a valve leaing to the evelopment of ganglion cysts, in a similar process to that which causes subchonral cysts. A stress rim fracture may also evelop at the periphery of the acetabulum, proucing a so-calle os acetabuli 34. True os acetabuli (calcification of a etache labrum) is morphologically similar, but the orientation of the cartilaginous growth plate is more parallel to the joint surface cause by the failure of the ring apophysis to fuse because of the increase stress on the rim 35. Clinical an Raiographic Evaluation Clinical Evaluation The clinical presentation of acetabular ysplasia can vary, but the most common symptom is groin pain 34. Nunley et al. 36 ocumente the onset of symptoms as insiious in 97% of patients, an 77% of the patients walke with a emonstrable limp, in which the pelvis roppe towar the unaffecte sie when weight-bearing on the affecte limb (the Trenelenburg gait pattern). In other patients, the trunk lurche towar the affecte sie (abuctor lurch) when the affecte limb was in the stance phase of gait. On examination, range-of-motion testing is generally normal, although the involve hip may be stiff in abuction an extension because of tight auctor an hip flexor muscles or if there is severe subluxation of the hip. Nakahara et al. 37, in a comparison of the range of motion an compute tomography (CT) scans of fifty-two ysplastic hips an seventy-two normal hips, foun that with maximum flexion an external rotation, extra-articular impingement was more frequently seen in the group with ysplasia. The authors postulate that the shallower acetabulum an greater femoral neck anteversion contribute to the increase maximum range of motion in DDH, preisposing to extra-articular posterior impingement. Imaging The structural anatomy of the ysplastic hip must be assesse in multiple planes using raiographs an, if neee, avance imaging moalities because of the high prevalence (>50%) of associate femoral eformities. The iagnosis of hip ysplasia can be mae on a well-centere anteroposterior raiograph of the pelvis by measuring the lateral center-ege angle (LCEA) of Wiberg 14 (Fig. 1). Currently, there is little isagreement that an LCEA of 25 is consiere normal, values of <20 are consistent with ysplasia, an those between 20 an 25 are juge by some authors as being transitional 14. Femoral hea coverage can also be measure with the acetabular inex of epth to with, i.e., the extrusion inex, escribe by Heyman an Hernon 38. A vertical center-anterior margin angle, also known as anterior center-ege angle of Lequesne an e Seze 39, quantifies anterior coverage of the femoral hea by the acetabulum. The anterior center-ege angle (ACEA) is measure on a lateral or so-calle false-profile raiograph (Fig. 2). An ACEA of >25 is consiere a normal anterior acetabular coverage. An ACEA measuring <20 is consiere iagnostic of ysplasia The normal femoral neck-shaft angle in aults Fig. 2 False-profile raiograph showing a vertical center-ege angle of 15. The lower inset is a Dunn lateral raiograph of the right hip showing a goo femoral hea-neck offset.

5 66 TABLE II Summary of Mi-Term to Long-Term Outcome of Intertrochanteric Surgery Stuy No. of Hips Proceure* Results* Mean Follow-up (Range) (yr) Level of Evience Ito et al. 60 (2005) 55 Varus ITO Satisfactory for 42% 17 (6-28) Therapeutic Level II Zweifel et al. 127 (2011) 52 Varus ITO Total hip arthroplasty elaye 17.8 (15-31) Therapeutic Level II >10 yr in 42% of patients Zaoussis et al. 128 (1984) 70 Rotational ITO Satisfactory for 75% 8 (6-15) Therapeutic Level III Tönnis 44 (1990) 136 Rotational an varus ITO Satisfactory for 90% after rotational ITO an for 16% after rotational an varus ITO *ITO = intertrochanteric osteotomy. As it was a multicenter stuy, the ata were not available (NA). NA Therapeutic Level IV has been reporte to range from 120 to The weightbearing acetabular inex (the Tönnis angle), or horizontal toit externe angle, quantifies the slope of the weight-bearing surface of the acetabulum or sourcil 44. This angle is forme between a horizontal an a tangential line extening from the meial to lateral eges of the sourcil; values of >10 are consistent with DDH (Table I). Nötzli et al. 45 escribe the abnormal superior position of the fovea capitis femoris on magnetic resonance imaging (MRI), also referre to as fovea alta, in the ault ysplastic hip. The angle (calle elta) forme between a line rawn from the center of the femoral hea to the meial ege of the sourcil an to the superior ege of the fovea capitis femoris shoul be 10. In surgical planning, joint congruity an subluxation are two aitional important raiographic factors. The Shenton line (an arc rawn from the meial aspect of the femoral neck through the superior margin of the obturator foramen) is a reliable an accurate raiographic marker to etect superior femoral hea subluxation 46. For joint congruity, Yasunaga et al. 47 evelope a classification system with four graes: excellent, inicating the subchonral plates of the acetabulum an the femoral hea are parallel an the joint space is uniformly maintaine; goo, the subchonral plates of the acetabulum an the femoral hea are not parallel, but the joint space is maintaine; fair, partial narrowing of the joint space; an poor, partial loss of the joint space. More recently, the three-imensional reconstruction capabilities of CT scans have enable a more precise evaluation of the severity of acetabular ysplasia 48-52, an they can contribute to preoperative planning 50. The aition of arthrography to CT was emonstrate to be a sensitive an reproucible metho for assessing substantial articular cartilage loss in patients with DDH 53, although CT-base assessment of hip ysplasia has the isavantages of raiation exposure of the patient an relative insensitivity to early changes of cartilage amage. Reporte MRI finings of labral isease in hip ysplasia inclue morphologic alterations, such as labral hypertrophy an tear, labral intrasubstance signal change, an labral chonral junction isruption 54. The position of the fovea capitis femoris can be easily etermine using the elta angle measurement on MRI 55. Avance biochemical MRI techniques, such as elaye gaolinium-enhance MRI of cartilage (GEMRIC), T2 mapping, an T1 rho, can reveal biochemical changes of the articular cartilage (loss of proteoglycan content an collagen amage) in the hip an therefore have the potential to etect early chonral injury in ysplastic hips before raiographically noticeable osteoarthritis 56. Of these imaging techniques, GEMRIC has been the most extensively stuie in regar to hip ysplasia an has been shown to be highly sensitive to arthritic changes as well as to symptoms 57. Also, a correlation has been foun between the GEMRIC value an the severity of ysplasia as measure with the LCEA 57 an a preictor of failure after periacetabular osteotomy 58. Surgical Management an Inications Femoral Osteotomy The rationale for the use of realigning varus an/or valgus osteotomies is to reuce stress throughout the cartilage surfaces in a hip that is compromise mechanically 59.Itoetal. 60 state that intertrochanteric osteotomy is worthwhile in hips with Tönnis grae-0, 1, or 2 osteoarthritis with a spherical femoral hea an mil ysplasia (Table II). Despite the excellent results of this proceure, a recent survey by Haverkamp et al. 61 showe that, even among experts, the use of intertrochanteric osteotomy in isolation for the treatment of hip ysplasia is eclining. The ecision for an ae proximal femoral osteotomy after periacetabular osteotomy is often one in surgery in orer to optimize joint congruency an/or range of motion. It is important to consier that ecrease femoral anteversion has a greater effect on hip motion than ecrease acetabular anteversion an is occasionally foun in patients with hip ysplasia 62. This le to the so-calle periacetabular osteotomy-first principle that ictate the sequence of early combine proceures, especially those without femoral obstacles to acetabular correction (extra-articular impingement) 63. Trousale et al. 64, who reporte a combine surgery rate of nearly 30% among hips with an osteoarthritis grae of >1, note that survivorship ecrease with increasingly egenerative changes. However, they i not specifically assess the subgroup with aitional intertrochanteric osteotomy. Clohisy et al. 63 emonstrate that combine proceures for complex eformities with lower clinical scores provie outcomes similar

6 67 Fig. 3 Illustration of the various pelvic osteotomies use to treat hip ysplasia. to those after isolate periacetabular osteotomy for simpler eformities. Pelvic Osteotomy There is a long history of reconstructive pelvic osteotomies in the treatment of acetabular ysplasia, which inclues the Salter innominate osteotomy 65, ouble innominate (e.g., Sutherlan 66 ), triple innominate (e.g., Steel 67 or Tönnis 44 ), spherical (e.g., Wagner 68 ), pericapsular (e.g., Pemberton 69 ), rotational acetabular osteotomies 70, an Bernese periacetabular osteotomy 71.Shelf proceures an the Chiari osteotomy 72 are salvage operations that improve coverage of the femoral hea by forming a new surface evoi of articular cartilage to support the femoral hea an create a capsular arthroplasty, using iliac crest bone grafts or an osteotomize fragment of ilium, respectively (Figs. 3 an 4). The Salter osteotomy, which was first escribe in , is not recommene in skeletally mature iniviuals as it consists of a shift of the acetabular roof anteriorly an laterally, leaing to acetabular retroversion. In oler teenagers, the triple osteotomy (for example, the one escribe by Steel 67 in 1973) provies an effective correction of acetabular ysplasia; however, because the posterior column is osteotomize, the mobilization of the patient is restricte in the first four to six weeks. In a large, single-center series, eighteen (55%) of thirtythree patients without a total hip replacement showe signs of osteoarthritis at twenty-five years of follow-up 73. In 1990, Tönnis 44 escribe a moification of the triple pelvic osteotomy, in which the ischial osteotomy was mae closer to the acetabulum. This permitte greater acetabular coverage of the femoral hea an, in particular, the translational movement in three planes. Long-term results showe measurements between 82% an 93% of normal an slightly pathologic values. Complete relief of pain was seen in 60.6% of patients. The rotational acetabular osteotomy has a long-staning history in Asia an was originally escribe by Ninomiya an Tagawa 74 as a spherical osteotomy proviing a large surface area for healing an leaving the pelvic ring intact. Takatori et al. 75 reporte the long-term results at a minimum of ten years after rotational acetabular osteotomy in thirteen severely ysplastic hips with subluxation in eleven women who were twenty to thirty-five-years ol; all patients ha minimal or no pain, an twelve of the thirteen hips showe no osteoarthritis. Ganz et al. 71,76 evelope a periacetabular osteotomy with orthogonal cuts, leaving the posterior column intact an not altering the shape of the true pelvis, which was first performe in Because this osteotomy is triplanar, it requires careful

7 68 Fig. 4 Anteroposterior pelvic raiograph after a periacetabular osteotomy was one on the right hip with correction of acetabular retroversion. three-imensional planning an is technically more ifficult; however, it also allows large corrections. Because of its capacity for large corrections, acetabular version nees to be carefully manage to avoi retroversion, which is alreay present in one in six patients with ysplasia 30,77. At ten an twenty years of follow-up, this proceure showe goo to excellent results in 73% an 60%, respectively, of the hips 78,79. However, if hips with preoperative osteoarthritis were exclue, the results improve to 88% an 75%, respectively 78. Factors associate with poor outcome inclue an oler age, the severity of osteoarthritis, an evience of labral pathology an poor acetabular inex postoperatively. These finings of poor joint congruity an the egree of arthritisaspreictorsoftheshorttomi-termoutcomeafterperiacetabular osteotomy have been reprouce by other groups 64, More recent reports on the results of periacetabular osteotomy from inepenent centers have focuse on etermining what clinical factors affect not only joint survivorship but also patient function 64,79,84-91 (Table III). Inepenent, poor prognostic factors inclue an age of more than thirty-five years at the time of the periacetabular osteotomy an poor preoperative joint congruity. Garbuz et al. 92 investigate the quality of life in patients more than forty years ol who unerwent periacetabular osteotomy (twenty-eight subjects) or total hip arthroplasty (thirty-three subjects). Although the results of total hip arthroplasty were superior, the overall success of the periacetabular osteotomy suggests that this proceure still has a role in patients oler than forty years. Similarly, Millis et al. 93, in a stuy of the results of periacetabular osteotomy in seventy patients (eighty-seven hips) with an average age of 43.6 years at the time of surgery, foun that 24% (twenty-one hips) ha unergone total hip arthroplasty within 5.2 years. The risk of total hip arthroplasty at five years after periacetabular osteotomy was 12% in hips with a preoperative Tönnis grae of 0 or 1 an 27% in hips with a Tönnis grae of 2. In a more recent stuy of the preictors of clinical outcome after periacetabular osteotomy, Beaulé etal. 94 foun that a higher preoperative alpha angle was significantly associate with a lower functional score postoperatively, potentially inicating more severe articular amage persisting after surgical correction.

8 69 TABLE III Summary of Mi-Term to Long-Term Outcome After Periacetabular Osteotomy* No. Demographic Data Mean Age (yr) Sex (F/M) Mean Follow-up (yr) Survivorship Preictors of Failure Level of Evience Garras et al. 89 (2007) Matheney et al. 79 (2009) Troelsen et al. 90 (2009) Steppacher et al. 78 (2008) Albers et al. 91 (2013) 52 patients (58 hips) 109 patients (135 hips) 96 patients (116 hips) / No survivorship ata provie; 7.7% conversion rate to total hip replacement at 3 yr / % at 5 yr an 84% at 10 yr / % at 5 yr an 81.6% at 9.2 yr 58 hips / % at 5 yr, 87.6% at 10 yr, an 60.0% at 20 yr 147 patients (165 hips) in 2 groups, with 43 hips in Group I (optimal orientation) an 122 hips in Group II (impingement: retroversion an/or aspherical hea) 29 in Group I an 28 in Group II 69%/31% of hips in Group I an 78%/22% in Group II % an 90.5% at 5 yr an 10 yr, respectively, for Group I, an 86.8% an 78.6% at 5 yr an 10 yr for Group II None ientifie Age of >35 yr at time of surgery an poor or fair preop. congruency; probability of failure was 14% if no preictor present, 36% if one present, an 95% if both present CE angle of <0, postop. sourcil with of <2.5 cm, presence of os acetabuli, an postop. istance to ilioischial line of 2.0 cm Age of 30 yr preop., Merle Aubigné score of <14, Tönnis grae of 2, an postop. extrusion inex of 20% Age of >30 yr preop., Merle Aubigné-Postel score of <15 points, preop. positive Trenelenburg sign, nonspherical hea, preop. OA grae of 1, Severin grae of >3, excessive acetabular anteversion, acetabular retroversion, LCE angle of >22 (unercoverage), an no offset correction in a nonspherical femoral hea Therapeutic Level II Prognostic Level II Prognostic Level II Prognostic Level III Therapeutic Level III *Reprouce, with moification, from: Beaulé PE, Dowing C, Parker G, Ryu JJ. What factors preict improvements in outcomes scores an reoperations after the Bernese periacetabular osteotomy? Clin Orthop Relat Res Feb;473(2): Reprouce with permission from Springer Science1Business Meia. CE = center-ege, OA = osteoarthritis, an LCE = lateral center-ege.

9 70 TABLE IV Hartofilakiis Classification* Dysplasia (Type A) Low islocation (Type B) High islocation (Type C) Femoral hea within acetabulum espite some subluxation, segmental eficiency of the superior wall, an inaequate epth of true acetabulum. Femoral hea creates a false acetabulum superior to the true acetabulum; there is complete absence of the superior wall an inaequate epth of the true acetabulum. Femoral hea is completely uncovere by the true acetabulum an has migrate superoposteriorly; there is a complete eficiency of the acetabulum an excessive anteversion of the true acetabulum. *Data are from Hartofilakiis et al The shelf proceure was first escribe by König 95 in 1891 an is base on the construction of a shelf of bone over a reuce femoral hea. Usually it is performe in chilren an aolescents. Fawzy et al. 96, in a stuy of seventy-six consecutive hips followe for a mean of eleven years after a shelf proceure, reporte a survivorship of 86% an 46% at five an ten years, respectively. The Chiari pelvic osteotomy is consiere a salvage proceure for ysplastic hips an works as a capsular interposition arthroplasty that shoul be consiere when other preserving proceures cannot be performe 72.Themain ifference, compare with the shelf proceure, is that the Chiari osteotomy allows the surgeon to achieve hip abuction. In a review of sixty-two Chiari osteotomies in aults, with a mean follow-up of 17.1 years, the survival rate (an stanar eviation) was 84.4% ± 4.8% at ten years an 68.6% ± 7.1% at twenty years, with avance raiographic osteoarthritis as the en point 97. Compare with the shelf osteotomy, which ha a survival rate of 37% at twenty years with joint replacement as the en point, the Chiari osteotomy appears to have a better survival rate of 68% at eighteen years in aults with DDH 98. We cannot overemphasize that pelvic osteotomies such as the periacetabular osteotomy are emaning proceures with a substantial learning curve an risk of major complications Hip Arthroscopy Poor short-term outcomes, incluing persistent pain an iatrogenic instability after labral ebriement or capsulotomy, have been emonstrate in several stuies in which patients with unerlying DDH were treate with hip arthroscopy alone (rather than as an ajunct to open surgery) Byran Jones 105 reporte on forty-eight ysplastic or borerline ysplastic hips (an LCEA of 20 to 25 ) in patients with a mean age of thirty-four years (range, fourteen to sixty-four years) at the time of arthroscopy. Although they ha an improvement in functional scores at one year, the scores ha ecrease at the two-year mark. Aitionally, acetabular chonral an labral lesions, mainly locate in the anterosuperior region, are common arthroscopic finings in up to 77.8% of hips with ysplasia 106,107. Consequently, the role of hip arthroscopy as an ajunct to a pelvic osteotomy 108,109 continues to evolve until it will allow concomitant treatment of chonral an/or labral lesions, potentially improving the postoperative clinical function. Recently, Domb et al. 110 escribe an arthroscopic approach for patients with mil ysplasia that inclues labral repair augmente by capsular plication with inferior shift. They reporte favorable results at the two-year follow-up for twenty-six patients with borerline ysplasia who were less than forty years ol. Total Hip Arthroplasty A useful classification system for surgical planning is the one escribe by Hartofilakiis et al. 111,112, which encompasses three types of eformity in the ault hip, i.e., ysplasia, low islocation, an high islocation (Table IV). Difficulties can arise TABLE V Graes of Recommenations for the Diagnosis an Treatment of Hip Dysplasia* Recommenation Diagnosis Hip ysplasia is a common cause of hip pain in young aults. Intra-articular amage is common, with labral pathology frequently evient. Hip ysplasia can present with a spectrum of osseous abnormality, incluing acetabular retroversion an proximal femoral eformities such as femoral hea asphericity. Treatment Osteotomies of the acetabulum are the most commonly use corrective proceures, with hip arthroscopy having an increasing role as an ajunct. In patients more than thirty-five years ol, total hip arthroplasty is an excellent treatment with a short recovery time. Grae A A A B B *Grae A inicates consistent, goo (Level-I) evience for or against the recommenation, an Grae B inicates consistent, fair (Level-II or III) evience for or against the recommenation, accoring to Wright et al. 129.

10 71 from anatomical abnormalities an previous operations. In a recent systematic review of the results of total hip replacement for hip ysplasia, Duncan et al. 113 foun that a comparison of the groups that ha or ha not ha a previous osteotomy faile to emonstrate any significant ifferences with respect to complications uring the perioperative perio. The consequence of previous operations on the outcome of a total hip arthroplasty is unclear 113. Boos et al. 114, in a comparison of the results of seventy-four total hip arthroplasties performe after a previous osteotomy matche by iagnosis to a control group of seventy-four patients who ha primary proceures, foun no significant ifference in the rate of perioperative complications or the rate of revisions. In a recent stuy, Migau et al. 115 compare the results of total hip arthroplasty in 159 hips that ha ha conservative surgery for DDH (sixty-four ha ha pelvic osteotomy; eighty-one, femoral osteotomy; an fourteen, combine pelvic an femoral osteotomies) an in 271 hips that ha not ha prior operations. The results were comparable between the groups. Preoperative assessment is always important if the patient ha a pelvic osteotomy performe because the position of the best available bone stock is altere. One of the most frequent complications of total hip replacement in patients with hip ysplasia is instability (0.9% to 11% in series ranging from twenty-three to 220 total hip arthroplasties) , an the overall rate of complications has been reporte to range from approximately 15% to 40% Overview The treatment of hip ysplasia in young aults remains a challenge. With the avent of avance imaging techniques as well as surgical techniques such as the periacetabular osteotomy, the capacity to preserve the hip an its function for a substantial perio is now well establishe (Table V). Continue refinements in iagnostic tools will better efine the role of hip arthroscopy, which at this time remains ill-efine with a potential role as an ajunct to the periacetabular osteotomy. Finally, current techniques of total hip replacement remain an excellent option for hips with avance changes an may be the preferable option in oler patients with hip ysplasia. n Luca Gala, MD 1 John C. Clohisy, MD 2 Paul E. Beaulé, MD, FRCSC 1 1 Division of Orthopaeic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canaa. 2 Washington University Orthopeics BJC Institute of Health, St. Louis, Missouri aress for P.E. Beaulé: pbeaule@ottawahospital.on.ca References 1. Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrate mechanical concept. Clin Orthop Relat Res Feb;466 (2): Epub 2008 Jan Clohisy JC, Beaulé PE, O Malley A, Safran MR, Schoenecker P. AOA symposium. Hip isease in the young ault: current concepts of etiology an surgical treatment. J Bone Joint Surg Am Oct;90(10): Aronson J. Osteoarthritis of the young ault hip: etiology an treatment. Instr Course Lect. 1986;35: Harris WH. Etiology of osteoarthritis of the hip. Clin Orthop Relat Res Dec;213: Solomon L. Patterns of osteoarthritis of the hip. J Bone Joint Surg Br May;58(2): Manaster BJ. From the RSNA Refresher Courses. Raiological Society of North America. Ault chronic hip pain: raiographic evaluation. Raiographics Oct;20(Spec No):S Bracken J, Tran T, Ditchfiel M. Developmental ysplasia of the hip: controversies an current concepts. J Paeiatr Chil Health Nov;48(11):963-72; quiz Chan A, McCaul KA, Cuny PJ, Haan EA, Byron-Scott R. Perinatal risk factors for evelopmental ysplasia of the hip. Arch Dis Chil Fetal Neonatal E Mar;76 (2):F Cay RB. Developmental ysplasia of the hip: efinition, recognition, an prevention of late sequelae. Peiatr Ann Feb;35(2): Bache CE, Clegg J, Herron M. Risk factors for evelopmental ysplasia of the hip: ultrasonographic finings in the neonatal perio. J Peiatr Orthop B Jul;11 (3): Murphy SB, Ganz R, Müller ME. The prognosis in untreate ysplasia of the hip. A stuy of raiographic factors that preict the outcome. J Bone Joint Surg Am Jul;77(7): Wege JH, Wasylenko MJ. The natural history of congenital islocation of the hip: a critical review. Clin Orthop Relat Res Nov-Dec;137: Wege JH, Wasylenko MJ. The natural history of congenital isease of the hip. J Bone Joint Surg Br Aug;61-B(3): Wiberg G. Stuies on ysplastic acetabula an congenital subluxation of the hip joint: with special reference to the complication of osteoarthritis. Acta Chir Scan. 1939;83(suppl)(58): Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint an their relationship to sex, groin pain, an risk of osteoarthritis: a population-base survey. J Bone Joint Surg Am May;92 (5): Jacobsen S, Sonne-Holm S. Hip ysplasia: a significant risk factor for the evelopment of hip osteoarthritis. A cross-sectional survey. Rheumatology (Oxfor) Feb;44(2): Epub 2004 Oct van Bosse H, Wege JH, Babyn P. How are ysplastic hips ifferent? A threeimensional CT stuy. Clin Orthop Relat Res May;473(5): Epub 2014 Dec Arman M, Lepistö J, Tallroth K, Elias J, Chao E. Outcome of periacetabular osteotomy: joint contact pressure calculation using staning AP raiographs, 12 patients followe for average 2 years. Acta Orthop Jun;76(3): Hipp JA, Sugano N, Millis MB, Murphy SB. Planning acetabular reirection osteotomies base on joint contact pressures. Clin Orthop Relat Res Jul;364: Michaeli DA, Murphy SB, Hipp JA. Comparison of preicte an measure contact pressures in normal an ysplastic hips. Me Eng Phys Mar;19 (2): Clohisy JC, Nunley RM, Carlisle JC, Schoenecker PL. Incience an characteristics of femoral eformities in the ysplastic hip. Clin Orthop Relat Res Jan;467(1): Epub 2008 Nov Henak CR, Abraham CL, Anerson AE, Maas SA, Ellis BJ, Peters CL, Weiss JA. Patient-specific analysis of cartilage an labrum mechanics in human hips with acetabular ysplasia. Osteoarthritis Cartilage Feb;22(2): Epub 2013 Nov Weinstein SL. Natural history of congenital hip islocation (CDH) an hip ysplasia. Clin Orthop Relat Res Dec;225: Clohisy JC, Dobson MA, Robison JF, Warth LC, Zheng J, Liu SS, Yehyawi TM, Callaghan JJ. Raiographic structural abnormalities associate with premature, natural hip-joint failure. J Bone Joint Surg Am May;93(Suppl 2): Stulberg SD. Unrecognize chilhoo hip isease: a major cause of iiopathic osteoarthritis of the hip. In: Corell LD, Harris WH, Ramsey PL, MacEwen GD, eitors. The Hip Proceeings of the Thir Open Scientific Meeting of the Hip Society. St. Louis: CV Mosby; p Cooperman DR, Wallensten R, Stulberg SD. Acetabular ysplasia in the ault. Clin Orthop Relat Res May;175:79-85.

11 Jessel RH, Zurakowski D, Zilkens C, Burstein D, Gray ML, Kim YJ. Raiographic an patient factors associate with pre-raiographic osteoarthritis in hip ysplasia. J Bone Joint Surg Am May;91(5): Fujii M, Nakashima Y, Yamamoto T, Mawatari T, Motomura G, Matsushita A, Matsua S, Jingushi S, Iwamoto Y. Acetabular retroversion in evelopmental ysplasia of the hip. J Bone Joint Surg Am Apr;92(4): Mast JW, Brunner RL, Zebrack J. Recognizing acetabular version in the raiographic presentation of hip ysplasia. Clin Orthop Relat Res Jan;418: Li PL, Ganz R. Morphologic features of congenital acetabular ysplasia: one in six is retroverte. Clin Orthop Relat Res Nov;416: Reynols D, Lucas J, Klaue K. Retroversion of the acetabulum. A cause of hip pain. J Bone Joint Surg Br Mar;81(2): Jamali AA, Mlaenov K, Meyer DC, Martinez A, Beck M, Ganz R, Leunig M. Anteroposterior pelvic raiographs to assess acetabular retroversion: high valiity of the cross-over-sign. J Orthop Res Jun;25(6): Leunig M, Poeszwa D, Beck M, Werlen S, Ganz R. Magnetic resonance arthrography of labral isorers in hips with ysplasia an impingement. Clin Orthop Relat Res Jan;418: Klaue K, Durnin CW, Ganz R. The acetabular rim synrome. A clinical presentation of ysplasia of the hip. J Bone Joint Surg Br May;73(3): Martinez AE, Li SM, Ganz R, Beck M. Os acetabuli in femoro-acetabular impingement: stress fracture or unfuse seconary ossification centre of the acetabular rim? Hip Int Oct-Dec;16(4): Nunley RM, Prather H, Hunt D, Schoenecker PL, Clohisy JC. Clinical presentation of symptomatic acetabular ysplasia in skeletally mature patients. J Bone Joint Surg Am May;93(Suppl 2): Nakahara I, Takao M, Sakai T, Miki H, Nishii T, Sugano N. Three-imensional morphology an bony range of movement in hip joints in patients with hip ysplasia. Bone Joint J May;96-B(5): Heyman CH, Hernon CH. Legg-Perthes isease; a metho for the measurement of the roentgenographic result. J Bone Joint Surg Am Oct;32(4): Lequesne M, e Seze. [False profile of the pelvis. A new raiographic incience for the stuy of the hip. Its use in ysplasias an ifferent coxopathies]. Rev Rhum Mal Osteoartic Dec;28: Klaue K, Wallin A, Ganz R. CT evaluation of coverage an congruency of the hip prior to osteotomy. Clin Orthop Relat Res Jul;232: Freensborg N. The CE angle of normal hips. Acta Orthop Scan Aug;47 (4): Manal S, Bhan S. The centre-ege angle of Wiberg in the ault Inian population. J Bone Joint Surg Br Mar;78(2): Reikerås O, Høiseth A, Reigsta A, Fönstelien E. Femoral neck angles: a specimen stuy with special regar to bilateral ifferences. Acta Orthop Scan Oct;53(5): Tönnis D. Surgical treatment of congenital islocation of the hip. Clin Orthop Relat Res Sep;258: Nötzli HP, Müller SM, Ganz R. [The relationship between fovea capitis femoris an weight bearing area in the normal an ysplastic hip in aults: a raiologic stuy]. Z Orthop Ihre Grenzgeb Nov-Dec;139(6): Rhee PC, Woocock JA, Clohisy JC, Millis M, Sucato DJ, Beaulé PE, Trousale RT, Sierra RJ; Acaemic Network for Conservational Hip Outcomes Research Group. The Shenton line in the iagnosis of acetabular ysplasia in the skeletally mature patient. J Bone Joint Surg Am May;93(Suppl 2): Yasunaga Y, Ochi M, Terayama H, Tanaka R, Yamasaki T, Ishii Y. Rotational acetabular osteotomy for avance osteoarthritis seconary to ysplasia of the hip. J Bone Joint Surg Am Sep;88(9): Haa FS, Garbuz DS, Duncan CP, Janzen DL, Munk PL. CT evaluation of periacetabular osteotomies. J Bone Joint Surg Br May;82(4): Nakamura S, Yorikawa J, Otsuka K, Takeshita K, Harasawa A, Matsushita T. Evaluation of acetabular ysplasia using a top view of the hip on three-imensional CT. J Orthop Sci. 2000;5(6): Ito H, Matsuno T, Hirayama T, Tanino H, Yamanaka Y, Minami A. Threeimensional compute tomography analysis of non-osteoarthritic ault acetabular ysplasia. Skeletal Raiol Feb;38(2): Epub 2008 Oct Mechlenburg I, Nyengaar JR, Rømer L, Søballe K. Changes in loa-bearing area after Ganz periacetabular osteotomy evaluate by multislice CT scanning an stereology. Acta Orthop Scan Apr;75(2): Tallroth K, Lepistö J. Compute tomography measurement of acetabular imensions: normal values for correction of ysplasia. Acta Orthop Aug;77(4): Nishii T, Tanaka H, Nakanishi K, Sugano N, Miki H, Yoshikawa H. Fatsuppresse 3D spoile graient-echo MRI an MDCT arthrography of articular cartilage in patients with hip ysplasia. AJR Am J Roentgenol Aug;185(2): James S, Miocevic M, Malara F, Pike J, Young D, Connell D. MR imaging finings of acetabular ysplasia in aults. Skeletal Raiol Jun;35(6): Epub 2006 Mar Beltran LS, Mayo JD, Rosenberg ZS, De Tuesta MD, Martin O, Neto LP Sr, Bencarino JT. Fovea alta on MR images: is it a marker of hip ysplasia in young aults? AJR Am J Roentgenol Oct;199(4): Beaulé PE, Kim YJ, Rakhra KS, Stelzeneer D, Brown TD. New frontiers in cartilage imaging of the hip. Instr Course Lect. 2012;61: Kim YJ, Jaramillo D, Millis MB, Gray ML, Burstein D. Assessment of early osteoarthritis in hip ysplasia with elaye gaolinium-enhance magnetic resonance imaging of cartilage. J Bone Joint Surg Am Oct;85(10): Cunningham T, Jessel R, Zurakowski D, Millis MB, Kim YJ. Delaye gaoliniumenhance magnetic resonance imaging of cartilage to preict early failure of Bernese periacetabular osteotomy for hip ysplasia. J Bone Joint Surg Am Jul;88 (7): Koulouvaris P, Stafylas K, Aznaoutoglou C, Zacharis K, Xenakis T. Isolate varus intertrochanteric osteotomy for hip ysplasia in 52 patients: long-term results. Int Orthop Apr;31(2): Epub 2006 Jun Ito H, Matsuno T, Minami A. Intertrochanteric varus osteotomy for osteoarthritis in patients with hip ysplasia: 6 to 28 years followup. Clin Orthop Relat Res Apr;433: Haverkamp D, Eijer H, Besselaar PP, Marti RK. Awareness an use of intertrochanteric osteotomies in current clinical practice. An international survey. Int Orthop Feb;32(1): Epub 2007 Apr Tönnis D, Heinecke A. Acetabular an femoral anteversion: relationship with osteoarthritis of the hip. J Bone Joint Surg Am Dec;81(12): Clohisy JC, St John LC, Nunley RM, Schutz AL, Schoenecker PL. Combine periacetabular an femoral osteotomies for severe hip eformities. Clin Orthop Relat Res Sep;467(9): Epub 2009 Mar Trousale RT, Ekkernkamp A, Ganz R, Wallrichs SL. Periacetabular an intertrochanteric osteotomy for the treatment of osteoarthrosis in ysplastic hips. J Bone Joint Surg Am Jan;77(1): Salter RB. The classic. Innominate osteotomy in the treatment of congenital islocation an subluxation of the hip by Robert B. Salter, J. Bone Joint Surg. (Brit) 43B:3:518, Clin Orthop Relat Res Nov-Dec;137: Sutherlan DH, Greenfiel R. Double innominate osteotomy. J Bone Joint Surg Am Dec;59(8): Steel HH. Triple osteotomy of the innominate bone. J Bone Joint Surg Am Mar;55(2): Wagner H. Osteotomies for congenital hip islocation. In: The hip. Proceeings of the fourth open scientific meeting of the Hip Society. St. Louis: CV Mosby; p Pemberton PA. Pericapsular osteotomy of the ilium for treatment of congenital subluxation an islocation of the hip. J Bone Joint Surg Am Jan;47: Hasegawa Y, Iwase T, Kitamura S, Kawasaki M, Yamaguchi J. Eccentric rotational acetabular osteotomy for acetabular ysplasia an osteoarthritis: follow-up at a mean uration of twenty years. J Bone Joint Surg Am Dec 3;96(23): Ganz R, Klaue K, Vinh TS, Mast JW. A new periacetabular osteotomy for the treatment of hip ysplasias. Technique an preliminary results. Clin Orthop Relat Res Jul;232: Chiari K. Meial isplacement osteotomy of the pelvis. Clin Orthop Relat Res Jan-Feb;98: van Stralen RA, van Hellemont GG, Ramrattan NN, e Visser E, e Kleuver M. Can a triple pelvic osteotomy for ault symptomatic hip ysplasia provie relief of symptoms for 25 years? Clin Orthop Relat Res Feb;471(2): Epub 2012 Nov Ninomiya S, Tagawa H. Rotational acetabular osteotomy for the ysplastic hip. J Bone Joint Surg Am Mar;66(3): Takatori Y, Ninomiya S, Nakamura S, Morimoto S, Sasaki T. Long-term follow-up results of rotational acetabular osteotomy in painful ysplastic hips: efficacy in elaying the onset of osteoarthritis. Am J Orthop Mar;25(3): Siebenrock KA, Leunig M, Ganz R. Periacetabular osteotomy: the Bernese experience. Instr Course Lect. 2001;50: Myers SR, Eijer H, Ganz R. Anterior femoroacetabular impingement after periacetabular osteotomy. Clin Orthop Relat Res Jun;363: Steppacher SD, Tannast M, Ganz R, Siebenrock KA. Mean 20-year followup of Bernese periacetabular osteotomy. Clin Orthop Relat Res Jul;466(7): Epub 2008 May Matheney T, Kim YJ, Zurakowski D, Matero C, Millis M. Intermeiate to longterm results following the Bernese periacetabular osteotomy an preictors of clinical outcome. J Bone Joint Surg Am Sep;91(9): Murphy S, Deshmukh R. Periacetabular osteotomy: preoperative raiographic preictors of outcome. Clin Orthop Relat Res Dec;405: Büchler L, Beck M. Periacetabular osteotomy: a review of Swiss experience. Curr Rev Musculoskelet Me Dec;7(4): Dahl LB, Dengsø K, Bang-Christiansen K, Petersen MM, Stürup J. Clinical an raiological outcome after periacetabular osteotomy: a cross-sectional stuy of 127 hips operate on from Hip Int Jul-Aug;24(4): Epub 2014 Apr 8.

12 Trumble SJ, Mayo KA, Mast JW. The periacetabular osteotomy. Minimum 2 year followup in more than 100 hips. Clin Orthop Relat Res Jun;363: Clohisy JC, Nunley RM, Curry MC, Schoenecker PL. Periacetabular osteotomy for the treatment of acetabular ysplasia associate with major aspherical femoral hea eformities. J Bone Joint Surg Am Jul;89(7): Clohisy JC, Barrett SE, Goron JE, Delgao ED, Schoenecker PL. Periacetabular osteotomy for the treatment of severe acetabular ysplasia. J Bone Joint Surg Am Feb;87(2): Leunig M, Siebenrock KA, Ganz R. Rationale of periacetabular osteotomy an backgroun work. Instr Course Lect. 2001;50: Millis MB, Kim YJ. Rationale of osteotomy an relate proceures for hip preservation: a review. Clin Orthop Relat Res Dec;405: Siebenrock KA, Schöll E, Lottenbach M, Ganz R. Bernese periacetabular osteotomy. Clin Orthop Relat Res Jun;363: Garras DN, Crower TT, Olson SA. Meium-term results of the Bernese periacetabular osteotomy in the treatment of symptomatic evelopmental ysplasia of the hip. J Bone Joint Surg Br Jun;89(6): Troelsen A, Elmengaar B, Søballe K. Meium-term outcome of periacetabular osteotomy an preictors of conversion to total hip replacement. J Bone Joint Surg Am Sep;91(9): Albers CE, Steppacher SD, Ganz R, Tannast M, Siebenrock KA. Impingement aversely affects 10-year survivorship after periacetabular osteotomy for DDH. Clin Orthop Relat Res May;471(5): Epub 2013 Jan Garbuz DS, Awwa MA, Duncan CP. Periacetabular osteotomy an total hip arthroplasty in patients oler than 40 years. J Arthroplasty Oct;23(7): Epub 2008 Mar Millis MB, Kain M, Sierra R, Trousale R, Taunton MJ, Kim YJ, Rosenfel SB, Kamath G, Schoenecker P, Clohisy JC. Periacetabular osteotomy for acetabular ysplasia in patients oler than 40 years: a preliminary stuy. Clin Orthop Relat Res Sep;467(9): Epub 2009 May Beaulé PE, Dowing C, Parker G, Ryu JJ. What factors preict improvements in outcomes scores an reoperations after the Bernese periacetabular osteotomy? Clin Orthop Relat Res Feb;473(2): König. Osteoplastische Behanlung er congenitalen Hüftgelenksluxation (mit Demonstration eines Praparates). Verhanl. Deutschen Gesellsch. Chir. 1891;10: German. 96. Fawzy E, Manellos G, De Steiger R, McLary-Smith P, Benson MK, Murray D. Is there a place for shelf acetabuloplasty in the management of ault acetabular ysplasia? A survivorship stuy. J Bone Joint Surg Br Sep;87 (9): Ohashi H, Hirohashi K, Yamano Y. Factors influencing the outcome of Chiari pelvic osteotomy: a long-term follow-up. J Bone Joint Surg Br May;82(4): Migau H, Chantelot C, Girau F, Fontaine C, Duquennoy A. Long-term survivorship of hip shelf arthroplasty an Chiari osteotomy in aults. Clin Orthop Relat Res Jan;418: Peters CL, Beaulé PE, Beck M, Tannast M, Jiranek W, Sierra RJ. Report of breakout session: Strategies to improve hip preservation training. Clin Orthop Relat Res Dec;470(12): Peters CL, Erickson JA, Hines JL. Early results of the Bernese periacetabular osteotomy: the learning curve at an acaemic meical center. J Bone Joint Surg Am Sep;88(9): Davey JP, Santore RF. Complications of periacetabular osteotomy. Clin Orthop Relat Res Jun;363: Kain MS, Novais EN, Vallim C, Millis MB, Kim YJ. Periacetabular osteotomy after faile hip arthroscopy for labral tears in patients with acetabular ysplasia. J Bone Joint Surg Am May;93(Suppl 2): Yamamoto Y, Ie T, Nakamura M, Hamaa Y, Usui I. Arthroscopic partial limbectomy in hip joints with acetabular hypoplasia. Arthroscopy May;21 (5): Parvizi J, Bican O, Bener B, Mortazavi SM, Purtill JJ, Erickson J, Peters C. Arthroscopy for labral tears in patients with evelopmental ysplasia of the hip: a cautionary note. J Arthroplasty Sep;24(6)(Suppl): Byr JW, Jones KS. Hip arthroscopy in the presence of ysplasia. Arthroscopy Dec;19(10): Kosuge D, Yamaa N, Azegami S, Achan P, Ramachanran M. Management of evelopmental ysplasia of the hip in young aults: current concepts. Bone Joint J Jun;95-B(6): Fujii M, Nakashima Y, Noguchi Y, Yamamoto T, Mawatari T, Motomura G, Iwamoto Y. Effect of intra-articular lesions on the outcome of periacetabular osteotomy in patients with symptomatic hip ysplasia. J Bone Joint Surg Br Nov;93 (11): Kim KI, Cho YJ, Ramteke AA, Yoo MC. Peri-acetabular rotational osteotomy with concomitant hip arthroscopy for treatment of hip ysplasia. J Bone Joint Surg Br Jun;93(6): Ross JR, Zaltz I, Nepple JJ, Schoenecker PL, Clohisy JC. Arthroscopic isease classification an interventions as an ajunct in the treatment of acetabular ysplasia. Am J Sports Me Jul;39(Suppl):72S-8S Domb BG, Stake CE, Linner D, El-Bitar Y, Jackson TJ. Arthroscopic capsular plication an labral preservation in borerline hip ysplasia: two-year clinical outcomes of a surgical approach to a challenging problem. Am J Sports Me Nov;41(11): Epub 2013 Aug Hartofilakiis G, Stamos K, Karachalios T, Ioanniis TT, Zacharakis N. Congenital hip isease in aults. Classification of acetabular eficiencies an operative treatment with acetabuloplasty combine with total hip arthroplasty. J Bone Joint Surg Am May;78(5): Yiannakopoulos CK, Xenakis T, Karachalios T, Babis GC, Hartofilakiis G. Reliability an valiity of the Hartofilakiis classification system of congenital hip isease in aults. Int Orthop Apr;33(2): Epub 2007 Nov Duncan S, Wingerter S, Keith A, Fowler SA, Clohisy J. Does previous osteotomy compromise total hip arthroplasty? A systematic review. J Arthroplasty Jan;30 (1): Epub 2014 Sep Boos N, Krushell R, Ganz R, Müller ME. Total hip arthroplasty after previous proximal femoral osteotomy. J Bone Joint Surg Br Mar;79(2): Migau H, Putman S, Berton C, Lefèvre C, Huten D, Argenson JN, Gaucher F. Does prior conservative surgery affect survivorship an functional outcome in total hip arthroplasty for congenital islocation of the hip? A case-control stuy in 159 hips. Orthop Traumatol Surg Res Nov;100(7): Epub 2014 Oct Anwar MM, Sugano N, Masuhara K, Kaowaki T, Takaoka K, Ono K. Total hip arthroplasty in the neglecte congenital islocation of the hip. A five- to 14-year follow-up stuy. Clin Orthop Relat Res Oct;(295): Tamegai H, Otani T, Fujii H, Kawaguchi Y, Hayama T, Marumo K. A moifie S-ROM stem in primary total hip arthroplasty for evelopmental ysplasia of the hip. J Arthroplasty Dec;28(10): Epub 2013 May Davlin LB, Amstutz HC, Tooke SM, Dorey FJ, Nasser S. Treatment of osteoarthrosis seconary to congenital islocation of the hip. Primary cemente surface replacement compare with conventional total hip replacement. J Bone Joint Surg Am Aug;72(7): Frein H, Sanzén L, Sigursson B, Unaner-Scharin L. Total hip arthroplasty in high congenital islocation. 21 hips with a minimum five-year follow-up. JBoneJoint Surg Br May;73(3): García-Cimbrelo E, Munuera L. Low-friction arthroplasty in severe acetabular ysplasia. J Arthroplasty Oct;8(5): Eskelinen A, Helenius I, Remes V, Ylinen P, Tallroth K, Paavilainen T. Cementless total hip arthroplasty in patients with high congenital hip islocation. J Bone Joint Surg Am Jan;88(1): Bruce WJ, Rizkallah SM, Kwon YM, Golberg JA, Walsh WR. A new technique of subtrochanteric shortening in total hip arthroplasty: surgical technique an results of 9 cases. J Arthroplasty Aug;15(5): Krych AJ, Howar JL, Trousale RT, Cabanela ME, Berry DJ. Total hip arthroplasty with shortening subtrochanteric osteotomy in Crowe type-iv evelopmental ysplasia. J Bone Joint Surg Am Sep;91(9): Park MS, Kim KH, Jeong WC. Transverse subtrochanteric shortening osteotomy in primary total hip arthroplasty for patients with severe hip evelopmental ysplasia. J Arthroplasty Oct;22(7): Makita H, Inaba Y, Hirakawa K, Saito T. Results on total hip arthroplasties with femoral shortening for Crowe s group IV islocate hips. J Arthroplasty Jan;22 (1): Nötzli HP, Wyss TF, Stoecklin CH, Schmi MR, Treiber K, Holer J. The contour of the femoral hea-neck junction as a preictor for the risk of anterior impingement. J Bone Joint Surg Br May;84(4): Zweifel J, Hönle W, Schuh A. Long-term results of intertrochanteric varus osteotomy for ysplastic osteoarthritis of the hip. Int Orthop Jan;35(1):9-12. Epub 2009 Sep Zaoussis AL, Aamopoulos G, Geraris G, Manolouis M, Galanis I. Osteotomy for osteoarthritis of the hip. A clinical an raiological survey. Int Orthop. 1984;7 (4): Wright JG, Einhorn TA, Heckman JD. Graes of recommenation. J Bone Joint Surg Sep;87(9):