Hip Dysplasia in the Young Adult

Gala, Luca MD1; Clohisy, John C. MD2; Beaulé, Paul E. MD, FRCSC1,a

Journal of Bone & Joint Surgery - American Volume:
doi: 10.2106/JBJS.O.00109
Current Concepts Review

➤ Hip dysplasia is a leading precursor of osteoarthritis and is seen in 20% to 40% of patients with osteoarthritis of the hip.

➤ An increase in mechanical stress on the cartilage matrix with failure of the acetabular labrum represents the major pathomechanism of degeneration.

➤ Because the prevalence of associated femoral deformities is high (>50%), the structural anatomy of the dysplastic hip must be assessed in multiple planes using radiographs and, if needed, advanced imaging modalities.

➤ Acetabular osteotomy (periacetabular and/or rotational) is the most commonly used procedure for the treatment of the majority of dysplastic hips in adults.

➤ Modern total hip replacement remains an excellent option for the more arthritic joints. Difficulties can arise from anatomical abnormalities and previous operations.

Author Information

1Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada.

2Washington University Orthopedics—BJC Institute of Health, St. Louis, Missouri

E-mail address for P.E. Beaulé: pbeaule@ottawahospital.on.ca

Article Outline
Back to Top | Article Outline

Descriptive Epidemiology

Refinements in understanding the etiology of secondary osteoarthritis have highlighted developmental dysplasia of the hip (DDH) and femoroacetabular impingement as leading precursors1,2. According to some estimates, DDH is involved in 20% to 40% of patients with osteoarthritis of the hip3-5. Despite the widespread screening for hip dysplasia at birth and during infancy, a substantial number of cases are not diagnosed until adulthood, with an estimated prevalence of 0.1% of the U.S. adult population6,7. Female sex, primiparity, breech position, and family history are known risk factors for hip dysplasia8-10. The lack of early intervention resulting from delayed diagnosis can lead to early onset of hip osteoarthritis and subsequent total hip replacement, although mild acetabular dysplasia has a variable and mostly benign natural history11-14.

According to a study of 3620 subjects conducted by Gosvig et al.15, the prevalence of dysplasia was 4.3% (fifty-eight of 1332) in men and 3.6% (eighty-two of 2288) in women. Jacobsen and Sonne-Holm16, in a cross-sectional survey of 2232 women and 1336 men, found a prevalence that ranged from 5.4% to 12.8%, depending on the radiographic index applied. In both of these studies, the patients were asymptomatic.

It is generally acknowledged that if DDH is recognized early, surgical correction of the abnormal anatomy diminishes the risk of osteoarthritis12,13.

Back to Top | Article Outline

Pathomechanism and Natural History

In patients with hip dysplasia, the typically shallow acetabulum leads to an increase in mechanical stress on the cartilage matrix, which can be beyond the physiologic level of tolerance14. Dysplastic acetabuli are not only deficient in a single plane or dimension but also are globally deficient both in shape and orientation, with the width remaining comparable with that of the nondysplastic acetabulum but with increased length and decreased depth. This leads not only to the classic anterior insufficiency but also, potentially, to lateral, posterior, or global deficiency17. Even with mild hip dysplasia, the poor coverage of the femoral head, the relative lateralization of the hip center of rotation, and the smaller contact area between the femoral head and the dysplastic acetabulum can produce an asymmetric concentration of force across the hip joint and secondary articular cartilage and labral damage18-20. The acetabular anomaly is usually accompanied by abnormalities of the proximal part of the femur, in which the femoral head is usually small and often aspherical with increased anteversion and neck-shaft angle (valgus)21. In a recent study, Henak et al.22 demonstrated that, in patients with a dysplastic hip, the acetabular labrum plays a greater role as a load-bearing structure and the labrum supported substantially more load than in normal hips.

The natural history of DDH has been well evaluated in the literature11-14,23-25 and has been noted to lead to the development of radiographic osteoarthritis in 25% to 50% of patients by a mean age of 50.3 years. More specifically, Wiberg14, in his study about congenital subluxation of the hip, noted that all of his patients with definite subluxation showed evidence of osteoarthritis by the age of fifty to sixty years. Murphy et al.11 followed the contralateral hip in 286 patients who had had a total hip arthroplasty for osteoarthritis secondary to dysplasia and observed that no patient in whom the hip survived into the seventh decade of life had a lateral center-edge angle of <16°, an acetabular index of >15°, or uncovering of the femoral head of >31%. Cooperman et al.26 followed thirty-two hips with a Wiberg angle of ≤20° for twenty-two years, and almost all patients had osteoarthritis at the time of the final follow-up when they were a mean of sixty-five years old. Moreover, early osteoarthritis appears to be more highly associated with anterior acetabular coverage deficiency than it is with lateral acetabular deficiency27. Most recently, acetabular retroversion has also been observed in patients with DDH28. Mast et al.29 studied the radiographs of 153 patients with DDH who were seen because of hip pain, to determine the usual version of the socket. Retroversion of the hip socket was noted in one in three hips. The same finding was highlighted by Li and Ganz30, with a lower prevalence of one in six hips (Fig. 1). It is important to mention that classic acetabular dysplasia and acetabular retroversion represent two distinct acetabular pathomorphologies. Retroversion in DDH is now mostly considered to represent posterior insufficiency and differs from a nondysplastic retroverted acetabulum that may be associated with impingement31,32.

Clohisy et al. showed that proximal femoral deformities were present in 92.6% of the 108 hips treated for symptomatic acetabular dysplasia, with 48% of the hips having coxa valga (44%) or coxa vara (4%)21. They also found that femoral head asphericity was present in 72% of the hips and reduced head-neck offset in 75%. They concluded that identifying and treating these proximal femoral abnormalities may optimize joint congruency and therefore minimize secondary impingement after reorientation of the acetabulum.

In dysplastic sockets, the acetabular labrum is often hypertrophic, probably in response to the increased load experienced by the front of the acetabulum to improve femoral head coverage and maintain joint lubrication33. This hypertrophic labrum can be remarkably effective at maintaining the mechanical equilibrium and preventing symptoms until adulthood34. The damaged labrum may also act as a valve leading to the development of ganglion cysts, in a similar process to that which causes subchondral cysts. A stress rim fracture may also develop at the periphery of the acetabulum, producing a so-called os acetabuli34. True os acetabuli (calcification of a detached labrum) is morphologically similar, but the orientation of the cartilaginous growth plate is more parallel to the joint surface caused by the failure of the ring apophysis to fuse because of the increased stress on the rim35.

Back to Top | Article Outline

Clinical and Radiographic Evaluation

Clinical Evaluation

The clinical presentation of acetabular dysplasia can vary, but the most common symptom is groin pain34. Nunley et al.36 documented the onset of symptoms as insidious in 97% of patients, and 77% of the patients walked with a demonstrable limp, in which the pelvis dropped toward the unaffected side when weight-bearing on the affected limb (the Trendelenburg gait pattern). In other patients, the trunk lurched toward the affected side (abductor lurch) when the affected limb was in the stance phase of gait. On examination, range-of-motion testing is generally normal, although the involved hip may be stiff in abduction and extension because of tight adductor and hip flexor muscles or if there is severe subluxation of the hip.

Nakahara et al.37, in a comparison of the range of motion and computed tomography (CT) scans of fifty-two dysplastic hips and seventy-two normal hips, found that with maximum flexion and external rotation, extra-articular impingement was more frequently seen in the group with dysplasia. The authors postulated that the shallower acetabulum and greater femoral neck anteversion contributed to the increased maximum range of motion in DDH, predisposing to extra-articular posterior impingement.

Back to Top | Article Outline

The structural anatomy of the dysplastic hip must be assessed in multiple planes using radiographs and, if needed, advanced imaging modalities because of the high prevalence (>50%) of associated femoral deformities. The diagnosis of hip dysplasia can be made on a well-centered anteroposterior radiograph of the pelvis by measuring the lateral center-edge angle (LCEA) of Wiberg14 (Fig. 1). Currently, there is little disagreement that an LCEA of ≥25° is considered normal, values of <20° are consistent with dysplasia, and those between 20° and 25° are judged by some authors as being transitional14. Femoral head coverage can also be measured with the acetabular index of depth to width, i.e., the extrusion index, described by Heyman and Herndon38. A vertical center-anterior margin angle, also known as anterior center-edge angle of Lequesne and de Seze39, quantifies anterior coverage of the femoral head by the acetabulum. The anterior center-edge angle (ACEA) is measured on a lateral or so-called false-profile radiograph (Fig. 2). An ACEA of >25° is considered a normal anterior acetabular coverage. An ACEA measuring <20° is considered diagnostic of dysplasia40-42. The normal femoral neck-shaft angle in adults has been reported to range from 120° to 135°43. The weight-bearing acetabular index (the Tönnis angle), or horizontal “toit externe” angle, quantifies the slope of the weight-bearing surface of the acetabulum or sourcil44. This angle is formed between a horizontal and a tangential line extending from the medial to lateral edges of the sourcil; values of >10° are consistent with DDH (Table I).

Nötzli et al.45 described the abnormal superior position of the fovea capitis femoris on magnetic resonance imaging (MRI), also referred to as fovea alta, in the adult dysplastic hip. The angle (called delta) formed between a line drawn from the center of the femoral head to the medial edge of the sourcil and to the superior edge of the fovea capitis femoris should be ≤10°. In surgical planning, joint congruity and subluxation are two additional important radiographic factors. The Shenton line (an arc drawn from the medial aspect of the femoral neck through the superior margin of the obturator foramen) is a reliable and accurate radiographic marker to detect superior femoral head subluxation46. For joint congruity, Yasunaga et al.47 developed a classification system with four grades: excellent, indicating the subchondral plates of the acetabulum and the femoral head are parallel and the joint space is uniformly maintained; good, the subchondral plates of the acetabulum and the femoral head are not parallel, but the joint space is maintained; fair, partial narrowing of the joint space; and poor, partial loss of the joint space.

More recently, the three-dimensional reconstruction capabilities of CT scans have enabled a more precise evaluation of the severity of acetabular dysplasia48-52, and they can contribute to preoperative planning50. The addition of arthrography to CT was demonstrated to be a sensitive and reproducible method for assessing substantial articular cartilage loss in patients with DDH53, although CT-based assessment of hip dysplasia has the disadvantages of radiation exposure of the patient and relative insensitivity to early changes of cartilage damage. Reported MRI findings of labral disease in hip dysplasia include morphologic alterations, such as labral hypertrophy and tear, labral intrasubstance signal change, and labral chondral junction disruption54. The position of the fovea capitis femoris can be easily determined using the delta angle measurement on MRI55. Advanced biochemical MRI techniques, such as delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T2 mapping, and T1 rho, can reveal biochemical changes of the articular cartilage (loss of proteoglycan content and collagen damage) in the hip and therefore have the potential to detect early chondral injury in dysplastic hips before radiographically noticeable osteoarthritis56. Of these imaging techniques, dGEMRIC has been the most extensively studied in regard to hip dysplasia and has been shown to be highly sensitive to arthritic changes as well as to symptoms57. Also, a correlation has been found between the dGEMRIC value and the severity of dysplasia as measured with the LCEA57 and a predictor of failure after periacetabular osteotomy58.

Back to Top | Article Outline

Surgical Management and Indications

Femoral Osteotomy

The rationale for the use of realigning varus and/or valgus osteotomies is to reduce stress throughout the cartilage surfaces in a hip that is compromised mechanically59. Ito et al.60 stated that intertrochanteric osteotomy is worthwhile in hips with Tönnis grade-0, 1, or 2 osteoarthritis with a spherical femoral head and mild dysplasia (Table II). Despite the excellent results of this procedure, a recent survey by Haverkamp et al.61 showed that, even among experts, the use of intertrochanteric osteotomy in isolation for the treatment of hip dysplasia is declining. The decision for an added proximal femoral osteotomy after periacetabular osteotomy is often done in surgery in order to optimize joint congruency and/or range of motion. It is important to consider that decreased femoral anteversion has a greater effect on hip motion than decreased acetabular anteversion and is occasionally found in patients with hip dysplasia62. This led to the so-called periacetabular osteotomy-first principle that dictated the sequence of early combined procedures, especially those without femoral obstacles to acetabular correction (extra-articular impingement)63. Trousdale et al.64, who reported a combined surgery rate of nearly 30% among hips with an osteoarthritis grade of >1, noted that survivorship decreased with increasingly degenerative changes. However, they did not specifically assess the subgroup with additional intertrochanteric osteotomy. Clohisy et al.63 demonstrated that combined procedures for complex deformities with lower clinical scores provide outcomes similar to those after isolated periacetabular osteotomy for simpler deformities.

Back to Top | Article Outline
Pelvic Osteotomy

There is a long history of reconstructive pelvic osteotomies in the treatment of acetabular dysplasia, which includes the Salter innominate osteotomy65, double innominate (e.g., Sutherland66), triple innominate (e.g., Steel67 or Tönnis44), spherical (e.g., Wagner68), pericapsular (e.g., Pemberton69), rotational acetabular osteotomies70, and Bernese periacetabular osteotomy71. Shelf procedures and the Chiari osteotomy72 are salvage operations that improve coverage of the femoral head by forming a new surface devoid of articular cartilage to support the femoral head and create a capsular arthroplasty, using iliac crest bone grafts or an osteotomized fragment of ilium, respectively (Figs. 3 and 4).

The Salter osteotomy, which was first described in 196165, is not recommended in skeletally mature individuals as it consists of a shift of the acetabular roof anteriorly and laterally, leading to acetabular retroversion. In older teenagers, the triple osteotomy (for example, the one described by Steel67 in 1973) provides an effective correction of acetabular dysplasia; however, because the posterior column is osteotomized, the mobilization of the patient is restricted in the first four to six weeks. In a large, single-center series, eighteen (55%) of thirty-three patients without a total hip replacement showed signs of osteoarthritis at twenty-five years of follow-up73. In 1990, Tönnis44 described a modification of the triple pelvic osteotomy, in which the ischial osteotomy was made closer to the acetabulum. This permitted greater acetabular coverage of the femoral head and, in particular, the translational movement in three planes. Long-term results showed measurements between 82% and 93% of normal and slightly pathologic values. Complete relief of pain was seen in 60.6% of patients.

The rotational acetabular osteotomy has a long-standing history in Asia and was originally described by Ninomiya and Tagawa74 as a spherical osteotomy providing a large surface area for healing and leaving the pelvic ring intact. Takatori et al.75 reported the long-term results at a minimum of ten years after rotational acetabular osteotomy in thirteen severely dysplastic hips with subluxation in eleven women who were twenty to thirty-five-years old; all patients had minimal or no pain, and twelve of the thirteen hips showed no osteoarthritis.

Ganz et al.71,76 developed a periacetabular osteotomy with orthogonal cuts, leaving the posterior column intact and not altering the shape of the true pelvis, which was first performed in 1982. Because this osteotomy is triplanar, it requires careful three-dimensional planning and is technically more difficult; however, it also allows large corrections. Because of its capacity for large corrections, acetabular version needs to be carefully managed to avoid retroversion, which is already present in one in six patients with dysplasia30,77.

At ten and twenty years of follow-up, this procedure showed good to excellent results in 73% and 60%, respectively, of the hips78,79. However, if hips with preoperative osteoarthritis were excluded, the results improved to 88% and 75%, respectively78. Factors associated with poor outcome included an older age, the severity of osteoarthritis, and evidence of labral pathology and poor acetabular index postoperatively.

These findings of poor joint congruity and the degree of arthritis as predictors of the short to mid-term outcome after periacetabular osteotomy have been reproduced by other groups64,80-83.

More recent reports on the results of periacetabular osteotomy from independent centers have focused on determining what clinical factors affect not only joint survivorship but also patient function64,79,84-91 (Table III). Independent, poor prognostic factors included an age of more than thirty-five years at the time of the periacetabular osteotomy and poor preoperative joint congruity. Garbuz et al.92 investigated the quality of life in patients more than forty years old who underwent 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 procedure still has a role in patients older than forty years. Similarly, Millis et al.93, in a study 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, found that 24% (twenty-one hips) had undergone 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 grade of 0 or 1 and 27% in hips with a Tönnis grade of 2. In a more recent study of the predictors of clinical outcome after periacetabular osteotomy, Beaulé et al.94 found that a higher preoperative alpha angle was significantly associated with a lower functional score postoperatively, potentially indicating more severe articular damage persisting after surgical correction.

The shelf procedure was first described by König95 in 1891 and is based on the construction of a shelf of bone over a reduced femoral head. Usually it is performed in children and adolescents. Fawzy et al.96, in a study of seventy-six consecutive hips followed for a mean of eleven years after a shelf procedure, reported a survivorship of 86% and 46% at five and ten years, respectively. The Chiari pelvic osteotomy is considered a salvage procedure for dysplastic hips and works as a capsular interposition arthroplasty that should be considered when other preserving procedures cannot be performed72. The main difference, compared with the shelf procedure, is that the Chiari osteotomy allows the surgeon to achieve hip abduction. In a review of sixty-two Chiari osteotomies in adults, with a mean follow-up of 17.1 years, the survival rate (and standard deviation) was 84.4% ± 4.8% at ten years and 68.6% ± 7.1% at twenty years, with advanced radiographic osteoarthritis as the end point97. Compared with the shelf osteotomy, which had a survival rate of 37% at twenty years with joint replacement as the end point, the Chiari osteotomy appears to have a better survival rate of 68% at eighteen years in adults with DDH98.

We cannot overemphasize that pelvic osteotomies such as the periacetabular osteotomy are demanding procedures with a substantial learning curve and risk of major complications99-101.

Back to Top | Article Outline
Hip Arthroscopy

Poor short-term outcomes, including persistent pain and iatrogenic instability after labral debridement or capsulotomy, have been demonstrated in several studies in which patients with underlying DDH were treated with hip arthroscopy alone (rather than as an adjunct to open surgery)102-104. Byrd and Jones105 reported on forty-eight dysplastic or borderline dysplastic 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 had an improvement in functional scores at one year, the scores had decreased at the two-year mark. Additionally, acetabular chondral and labral lesions, mainly located in the anterosuperior region, are common arthroscopic findings in up to 77.8% of hips with dysplasia106,107. Consequently, the role of hip arthroscopy as an adjunct to a pelvic osteotomy108,109 continues to evolve until it will allow concomitant treatment of chondral and/or labral lesions, potentially improving the postoperative clinical function.

Recently, Domb et al.110 described an arthroscopic approach for patients with mild dysplasia that includes labral repair augmented by capsular plication with inferior shift. They reported favorable results at the two-year follow-up for twenty-six patients with borderline dysplasia who were less than forty years old.

Back to Top | Article Outline
Total Hip Arthroplasty

A useful classification system for surgical planning is the one described by Hartofilakidis et al.111,112, which encompasses three types of deformity in the adult hip, i.e., dysplasia, low dislocation, and high dislocation (Table IV). Difficulties can arise from anatomical abnormalities and previous operations. In a recent systematic review of the results of total hip replacement for hip dysplasia, Duncan et al.113 found that a comparison of the groups that had or had not had a previous osteotomy failed to demonstrate any significant differences with respect to complications during the perioperative period. The consequence of previous operations on the outcome of a total hip arthroplasty is unclear113. Boos et al.114, in a comparison of the results of seventy-four total hip arthroplasties performed after a previous osteotomy matched by diagnosis to a control group of seventy-four patients who had primary procedures, found no significant difference in the rate of perioperative complications or the rate of revisions. In a recent study, Migaud et al.115 compared the results of total hip arthroplasty in 159 hips that had had conservative surgery for DDH (sixty-four had had pelvic osteotomy; eighty-one, femoral osteotomy; and fourteen, combined pelvic and femoral osteotomies) and in 271 hips that had not had prior operations. The results were comparable between the groups. Preoperative assessment is always important if the patient had a pelvic osteotomy performed because the position of the best available bone stock is altered. One of the most frequent complications of total hip replacement in patients with hip dysplasia is instability (0.9% to 11% in series ranging from twenty-three to 220 total hip arthroplasties)116-120, and the overall rate of complications has been reported to range from approximately 15% to 40%121-125.

Back to Top | Article Outline


The treatment of hip dysplasia in young adults remains a challenge. With the advent of advanced imaging techniques as well as surgical techniques such as the periacetabular osteotomy, the capacity to preserve the hip and its function for a substantial period is now well established (Table V). Continued refinements in diagnostic tools will better define the role of hip arthroscopy, which at this time remains ill-defined with a potential role as an adjunct to the periacetabular osteotomy. Finally, current techniques of total hip replacement remain an excellent option for hips with advanced changes and may be the preferable option in older patients with hip dysplasia.

Investigation performed at the Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada

Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. One or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.

Back to Top | Article Outline


1. Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res. 2008 ;466(2):264–72. Epub 2008 Jan 10.
2. Clohisy JC, Beaulé PE, O’Malley A, Safran MR, Schoenecker P. AOA symposium. Hip disease in the young adult: current concepts of etiology and surgical treatment. J Bone Joint Surg Am. 2008 ;90(10):2267–81.
3. Aronson J. Osteoarthritis of the young adult hip: etiology and treatment. Instr Course Lect. 1986;35:119–28.
4. Harris WH. Etiology of osteoarthritis of the hip. Clin Orthop Relat Res. 1986 ;213:20–33.
5. Solomon L. Patterns of osteoarthritis of the hip. J Bone Joint Surg Br. 1976 ;58(2):176–83.
6. Manaster BJ. From the RSNA Refresher Courses. Radiological Society of North America. Adult chronic hip pain: radiographic evaluation. Radiographics. 2000 ;20(Spec No):S3–25.
7. Bracken J, Tran T, Ditchfield M. Developmental dysplasia of the hip: controversies and current concepts. J Paediatr Child Health. 2012 ;48(11):963–72; quiz 972-3.
8. Chan A, McCaul KA, Cundy PJ, Haan EA, Byron-Scott R. Perinatal risk factors for developmental dysplasia of the hip. Arch Dis Child Fetal Neonatal Ed. 1997 ;76(2):F94–100.
9. Cady RB. Developmental dysplasia of the hip: definition, recognition, and prevention of late sequelae. Pediatr Ann. 2006 ;35(2):92–101.
10. Bache CE, Clegg J, Herron M. Risk factors for developmental dysplasia of the hip: ultrasonographic findings in the neonatal period. J Pediatr Orthop B. 2002 ;11(3):212–8.
11. Murphy SB, Ganz R, Müller ME. The prognosis in untreated dysplasia of the hip. A study of radiographic factors that predict the outcome. J Bone Joint Surg Am. 1995 ;77(7):985–9.
12. Wedge JH, Wasylenko MJ. The natural history of congenital dislocation of the hip: a critical review. Clin Orthop Relat Res. 1978 ;137:154–62.
13. Wedge JH, Wasylenko MJ. The natural history of congenital disease of the hip. J Bone Joint Surg Br. 1979 ;61-B(3):334–8.
14. Wiberg G. Studies on dysplastic acetabula and congenital subluxation of the hip joint: with special reference to the complication of osteoarthritis. Acta Chir Scand. 1939;83(suppl)(58):5–135.
15. Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey. J Bone Joint Surg Am. 2010 ;92(5):1162–9.
16. Jacobsen S, Sonne-Holm S. Hip dysplasia: a significant risk factor for the development of hip osteoarthritis. A cross-sectional survey. Rheumatology (Oxford). 2005 ;44(2):211–8. Epub 2004 Oct 12.
17. van Bosse H, Wedge JH, Babyn P. How are dysplastic hips different? A three-dimensional CT study. Clin Orthop Relat Res. 2015 ;473(5):1712–23. Epub 2014 Dec 19.
18. Armand M, Lepistö J, Tallroth K, Elias J, Chao E. Outcome of periacetabular osteotomy: joint contact pressure calculation using standing AP radiographs, 12 patients followed for average 2 years. Acta Orthop. 2005 ;76(3):303–13.
19. Hipp JA, Sugano N, Millis MB, Murphy SB. Planning acetabular redirection osteotomies based on joint contact pressures. Clin Orthop Relat Res. 1999 ;364:134–43.
20. Michaeli DA, Murphy SB, Hipp JA. Comparison of predicted and measured contact pressures in normal and dysplastic hips. Med Eng Phys. 1997 ;19(2):180–6.
21. Clohisy JC, Nunley RM, Carlisle JC, Schoenecker PL. Incidence and characteristics of femoral deformities in the dysplastic hip. Clin Orthop Relat Res. 2009 ;467(1):128–34. Epub 2008 Nov 26.
22. Henak CR, Abraham CL, Anderson AE, Maas SA, Ellis BJ, Peters CL, Weiss JA. Patient-specific analysis of cartilage and labrum mechanics in human hips with acetabular dysplasia. Osteoarthritis Cartilage. 2014 ;22(2):210–7. Epub 2013 Nov 22.
23. Weinstein SL. Natural history of congenital hip dislocation (CDH) and hip dysplasia. Clin Orthop Relat Res. 1987 ;225:62–76.
24. Clohisy JC, Dobson MA, Robison JF, Warth LC, Zheng J, Liu SS, Yehyawi TM, Callaghan JJ. Radiographic structural abnormalities associated with premature, natural hip-joint failure. J Bone Joint Surg Am. 2011 ;93(Suppl 2):3–9.
25. Stulberg SD. Unrecognized childhood hip disease: a major cause of idiopathic osteoarthritis of the hip. In: Cordell LD, Harris WH, Ramsey PL, MacEwen GD, editors. The Hip Proceedings of the Third Open Scientific Meeting of the Hip Society. St. Louis: CV Mosby; 1975. p 212–20.
26. Cooperman DR, Wallensten R, Stulberg SD. Acetabular dysplasia in the adult. Clin Orthop Relat Res. 1983 ;175:79–85.
27. Jessel RH, Zurakowski D, Zilkens C, Burstein D, Gray ML, Kim YJ. Radiographic and patient factors associated with pre-radiographic osteoarthritis in hip dysplasia. J Bone Joint Surg Am. 2009 ;91(5):1120–9.
28. Fujii M, Nakashima Y, Yamamoto T, Mawatari T, Motomura G, Matsushita A, Matsuda S, Jingushi S, Iwamoto Y. Acetabular retroversion in developmental dysplasia of the hip. J Bone Joint Surg Am. 2010 ;92(4):895–903.
29. Mast JW, Brunner RL, Zebrack J. Recognizing acetabular version in the radiographic presentation of hip dysplasia. Clin Orthop Relat Res. 2004 ;418:48–53.
30. Li PL, Ganz R. Morphologic features of congenital acetabular dysplasia: one in six is retroverted. Clin Orthop Relat Res. 2003 ;416:245–53.
31. Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum. A cause of hip pain. J Bone Joint Surg Br. 1999 ;81(2):281–8.
32. Jamali AA, Mladenov K, Meyer DC, Martinez A, Beck M, Ganz R, Leunig M. Anteroposterior pelvic radiographs to assess acetabular retroversion: high validity of the “cross-over-sign”. J Orthop Res. 2007 ;25(6):758–65.
33. Leunig M, Podeszwa D, Beck M, Werlen S, Ganz R. Magnetic resonance arthrography of labral disorders in hips with dysplasia and impingement. Clin Orthop Relat Res. 2004 ;418:74–80.
34. Klaue K, Durnin CW, Ganz R. The acetabular rim syndrome. A clinical presentation of dysplasia of the hip. J Bone Joint Surg Br. 1991 ;73(3):423–9.
35. Martinez AE, Li SM, Ganz R, Beck M. Os acetabuli in femoro-acetabular impingement: stress fracture or unfused secondary ossification centre of the acetabular rim? Hip Int. 2006 ;16(4):281–6.
36. Nunley RM, Prather H, Hunt D, Schoenecker PL, Clohisy JC. Clinical presentation of symptomatic acetabular dysplasia in skeletally mature patients. J Bone Joint Surg Am. 2011 ;93(Suppl 2):17–21.
37. Nakahara I, Takao M, Sakai T, Miki H, Nishii T, Sugano N. Three-dimensional morphology and bony range of movement in hip joints in patients with hip dysplasia. Bone Joint J. 2014 ;96-B(5):580–9.
38. Heyman CH, Herndon CH. Legg-Perthes disease; a method for the measurement of the roentgenographic result. J Bone Joint Surg Am. 1950 ;32(4):767–78.
39. Lequesne M, de Seze. [False profile of the pelvis. A new radiographic incidence for the study of the hip. Its use in dysplasias and different coxopathies]. Rev Rhum Mal Osteoartic. 1961 ;28:643–52.
40. Klaue K, Wallin A, Ganz R. CT evaluation of coverage and congruency of the hip prior to osteotomy. Clin Orthop Relat Res. 1988 ;232:15–25.
41. Fredensborg N. The CE angle of normal hips. Acta Orthop Scand. 1976 ;47(4):403–5.
42. Mandal S, Bhan S. The centre-edge angle of Wiberg in the adult Indian population. J Bone Joint Surg Br. 1996 ;78(2):320–1.
43. Reikerås O, Høiseth A, Reigstad A, Fönstelien E. Femoral neck angles: a specimen study with special regard to bilateral differences. Acta Orthop Scand. 1982 ;53(5):775–9.
44. Tönnis D. Surgical treatment of congenital dislocation of the hip. Clin Orthop Relat Res. 1990 ;258:33–40.
45. Nötzli HP, Müller SM, Ganz R. [The relationship between fovea capitis femoris and weight bearing area in the normal and dysplastic hip in adults: a radiologic study]. Z Orthop Ihre Grenzgeb. 2001 ;139(6):502–6.
46. Rhee PC, Woodcock JA, Clohisy JC, Millis M, Sucato DJ, Beaulé PE, Trousdale RT, Sierra RJ; Academic Network for Conservational Hip Outcomes Research Group. The Shenton line in the diagnosis of acetabular dysplasia in the skeletally mature patient. J Bone Joint Surg Am. 2011 ;93(Suppl 2):35–9.
47. Yasunaga Y, Ochi M, Terayama H, Tanaka R, Yamasaki T, Ishii Y. Rotational acetabular osteotomy for advanced osteoarthritis secondary to dysplasia of the hip. J Bone Joint Surg Am. 2006 ;88(9):1915–9.
48. Haddad FS, Garbuz DS, Duncan CP, Janzen DL, Munk PL. CT evaluation of periacetabular osteotomies. J Bone Joint Surg Br. 2000 ;82(4):526–31.
49. Nakamura S, Yorikawa J, Otsuka K, Takeshita K, Harasawa A, Matsushita T. Evaluation of acetabular dysplasia using a top view of the hip on three-dimensional CT. J Orthop Sci. 2000;5(6):533–9.
50. Ito H, Matsuno T, Hirayama T, Tanino H, Yamanaka Y, Minami A. Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia. Skeletal Radiol. 2009 ;38(2):131–9. Epub 2008 Oct 1.
51. Mechlenburg I, Nyengaard JR, Rømer L, Søballe K. Changes in load-bearing area after Ganz periacetabular osteotomy evaluated by multislice CT scanning and stereology. Acta Orthop Scand. 2004 ;75(2):147–53.
52. Tallroth K, Lepistö J. Computed tomography measurement of acetabular dimensions: normal values for correction of dysplasia. Acta Orthop. 2006 ;77(4):598–602.
53. Nishii T, Tanaka H, Nakanishi K, Sugano N, Miki H, Yoshikawa H. Fat-suppressed 3D spoiled gradient-echo MRI and MDCT arthrography of articular cartilage in patients with hip dysplasia. AJR Am J Roentgenol. 2005 ;185(2):379–85.
54. James S, Miocevic M, Malara F, Pike J, Young D, Connell D. MR imaging findings of acetabular dysplasia in adults. Skeletal Radiol. 2006 ;35(6):378–84. Epub 2006 Mar 29.
55. Beltran LS, Mayo JD, Rosenberg ZS, De Tuesta MD, Martin O, Neto LP Sr, Bencardino JT. Fovea alta on MR images: is it a marker of hip dysplasia in young adults? AJR Am J Roentgenol. 2012 ;199(4):879–83.
56. Beaulé PE, Kim YJ, Rakhra KS, Stelzeneder D, Brown TD. New frontiers in cartilage imaging of the hip. Instr Course Lect. 2012;61:253–62.
57. Kim YJ, Jaramillo D, Millis MB, Gray ML, Burstein D. Assessment of early osteoarthritis in hip dysplasia with delayed gadolinium-enhanced magnetic resonance imaging of cartilage. J Bone Joint Surg Am. 2003 ;85(10):1987–92.
58. Cunningham T, Jessel R, Zurakowski D, Millis MB, Kim YJ. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage to predict early failure of Bernese periacetabular osteotomy for hip dysplasia. J Bone Joint Surg Am. 2006 ;88(7):1540–8.
59. Koulouvaris P, Stafylas K, Aznaoutoglou C, Zacharis K, Xenakis T. Isolated varus intertrochanteric osteotomy for hip dysplasia in 52 patients: long-term results. Int Orthop. 2007 ;31(2):193–8. Epub 2006 Jun 17.
60. Ito H, Matsuno T, Minami A. Intertrochanteric varus osteotomy for osteoarthritis in patients with hip dysplasia: 6 to 28 years followup. Clin Orthop Relat Res. 2005 ;433:124–8.
61. Haverkamp D, Eijer H, Besselaar PP, Marti RK. Awareness and use of intertrochanteric osteotomies in current clinical practice. An international survey. Int Orthop. 2008 ;32(1):19–25. Epub 2007 Apr 13.
62. Tönnis D, Heinecke A. Acetabular and femoral anteversion: relationship with osteoarthritis of the hip. J Bone Joint Surg Am. 1999 ;81(12):1747–70.
63. Clohisy JC, St John LC, Nunley RM, Schutz AL, Schoenecker PL. Combined periacetabular and femoral osteotomies for severe hip deformities. Clin Orthop Relat Res. 2009 ;467(9):2221–7. Epub 2009 Mar 31.
64. Trousdale RT, Ekkernkamp A, Ganz R, Wallrichs SL. Periacetabular and intertrochanteric osteotomy for the treatment of osteoarthrosis in dysplastic hips. J Bone Joint Surg Am. 1995 ;77(1):73–85.
65. Salter RB. The classic. Innominate osteotomy in the treatment of congenital dislocation and subluxation of the hip by Robert B. Salter, J. Bone Joint Surg. (Brit) 43B:3:518, 1961. Clin Orthop Relat Res. 1978 ;137:2–14.
66. Sutherland DH, Greenfield R. Double innominate osteotomy. J Bone Joint Surg Am. 1977 ;59(8):1082–91.
67. Steel HH. Triple osteotomy of the innominate bone. J Bone Joint Surg Am. 1973 ;55(2):343–50.
68. Wagner H. Osteotomies for congenital hip dislocation. In: The hip. Proceedings of the fourth open scientific meeting of the Hip Society. St. Louis: CV Mosby; 1976. p 45–66.
69. Pemberton PA. Pericapsular osteotomy of the ilium for treatment of congenital subluxation and dislocation of the hip. J Bone Joint Surg Am. 1965 ;47:65–86.
70. Hasegawa Y, Iwase T, Kitamura S, Kawasaki M, Yamaguchi J. Eccentric rotational acetabular osteotomy for acetabular dysplasia and osteoarthritis: follow-up at a mean duration of twenty years. J Bone Joint Surg Am. 2014 ;96(23):1975–82.
71. Ganz R, Klaue K, Vinh TS, Mast JW. A new periacetabular osteotomy for the treatment of hip dysplasias. Technique and preliminary results. Clin Orthop Relat Res. 1988 ;232:26–36.
72. Chiari K. Medial displacement osteotomy of the pelvis. Clin Orthop Relat Res. 1974 ;98:55–71.
73. van Stralen RA, van Hellemondt GG, Ramrattan NN, de Visser E, de Kleuver M. Can a triple pelvic osteotomy for adult symptomatic hip dysplasia provide relief of symptoms for 25 years? Clin Orthop Relat Res. 2013 ;471(2):584–90. Epub 2012 Nov 21.
74. Ninomiya S, Tagawa H. Rotational acetabular osteotomy for the dysplastic hip. J Bone Joint Surg Am. 1984 ;66(3):430–6.
75. Takatori Y, Ninomiya S, Nakamura S, Morimoto S, Sasaki T. Long-term follow-up results of rotational acetabular osteotomy in painful dysplastic hips: efficacy in delaying the onset of osteoarthritis. Am J Orthop. 1996 ;25(3):222–5.
76. Siebenrock KA, Leunig M, Ganz R. Periacetabular osteotomy: the Bernese experience. Instr Course Lect. 2001;50:239–45.
77. Myers SR, Eijer H, Ganz R. Anterior femoroacetabular impingement after periacetabular osteotomy. Clin Orthop Relat Res. 1999 ;363:93–9.
78. Steppacher SD, Tannast M, Ganz R, Siebenrock KA. Mean 20-year followup of Bernese periacetabular osteotomy. Clin Orthop Relat Res. 2008 ;466(7):1633–44. Epub 2008 May 1.
79. Matheney T, Kim YJ, Zurakowski D, Matero C, Millis M. Intermediate to long-term results following the Bernese periacetabular osteotomy and predictors of clinical outcome. J Bone Joint Surg Am. 2009 ;91(9):2113–23.
80. Murphy S, Deshmukh R. Periacetabular osteotomy: preoperative radiographic predictors of outcome. Clin Orthop Relat Res. 2002 ;405:168–74.
81. Büchler L, Beck M. Periacetabular osteotomy: a review of Swiss experience. Curr Rev Musculoskelet Med. 2014 ;7(4):330–6.
82. Dahl LB, Dengsø K, Bang-Christiansen K, Petersen MM, Stürup J. Clinical and radiological outcome after periacetabular osteotomy: a cross-sectional study of 127 hips operated on from 1999-2008. Hip Int. 2014 ;24(4):369–80. Epub 2014 Apr 8.
83. Trumble SJ, Mayo KA, Mast JW. The periacetabular osteotomy. Minimum 2 year followup in more than 100 hips. Clin Orthop Relat Res. 1999 ;363:54–63.
84. Clohisy JC, Nunley RM, Curry MC, Schoenecker PL. Periacetabular osteotomy for the treatment of acetabular dysplasia associated with major aspherical femoral head deformities. J Bone Joint Surg Am. 2007 ;89(7):1417–23.
85. Clohisy JC, Barrett SE, Gordon JE, Delgado ED, Schoenecker PL. Periacetabular osteotomy for the treatment of severe acetabular dysplasia. J Bone Joint Surg Am. 2005 ;87(2):254–9.
86. Leunig M, Siebenrock KA, Ganz R. Rationale of periacetabular osteotomy and background work. Instr Course Lect. 2001;50:229–38.
87. Millis MB, Kim YJ. Rationale of osteotomy and related procedures for hip preservation: a review. Clin Orthop Relat Res. 2002 ;405:108–21.
88. Siebenrock KA, Schöll E, Lottenbach M, Ganz R. Bernese periacetabular osteotomy. Clin Orthop Relat Res. 1999 ;363:9–20.
89. Garras DN, Crowder TT, Olson SA. Medium-term results of the Bernese periacetabular osteotomy in the treatment of symptomatic developmental dysplasia of the hip. J Bone Joint Surg Br. 2007 ;89(6):721–4.
90. Troelsen A, Elmengaard B, Søballe K. Medium-term outcome of periacetabular osteotomy and predictors of conversion to total hip replacement. J Bone Joint Surg Am. 2009 ;91(9):2169–79.
91. Albers CE, Steppacher SD, Ganz R, Tannast M, Siebenrock KA. Impingement adversely affects 10-year survivorship after periacetabular osteotomy for DDH. Clin Orthop Relat Res. 2013 ;471(5):1602–14. Epub 2013 Jan 25.
92. Garbuz DS, Awwad MA, Duncan CP. Periacetabular osteotomy and total hip arthroplasty in patients older than 40 years. J Arthroplasty. 2008 ;23(7):960–3. Epub 2008 Mar 14.
93. Millis MB, Kain M, Sierra R, Trousdale R, Taunton MJ, Kim YJ, Rosenfeld SB, Kamath G, Schoenecker P, Clohisy JC. Periacetabular osteotomy for acetabular dysplasia in patients older than 40 years: a preliminary study. Clin Orthop Relat Res. 2009 ;467(9):2228–34. Epub 2009 May 7.
94. Beaulé PE, Dowding C, Parker G, Ryu JJ. What factors predict improvements in outcomes scores and reoperations after the Bernese periacetabular osteotomy? Clin Orthop Relat Res. 2015 ;473(2):615–22.
95. König. Osteoplastische Behandlung der congenitalen Hüftgelenksluxation (mit Demonstration eines Praparates). Verhandl. Deutschen Gesellsch. Chir. 1891;10:75–80. German.
96. Fawzy E, Mandellos G, De Steiger R, McLardy-Smith P, Benson MK, Murray D. Is there a place for shelf acetabuloplasty in the management of adult acetabular dysplasia? A survivorship study. J Bone Joint Surg Br. 2005 ;87(9):1197–202.
97. Ohashi H, Hirohashi K, Yamano Y. Factors influencing the outcome of Chiari pelvic osteotomy: a long-term follow-up. J Bone Joint Surg Br. 2000 ;82(4):517–25.
98. Migaud H, Chantelot C, Giraud F, Fontaine C, Duquennoy A. Long-term survivorship of hip shelf arthroplasty and Chiari osteotomy in adults. Clin Orthop Relat Res. 2004 ;418:81–6.
99. 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. 2012 ;470(12):3467–9.
100. Peters CL, Erickson JA, Hines JL. Early results of the Bernese periacetabular osteotomy: the learning curve at an academic medical center. J Bone Joint Surg Am. 2006 ;88(9):1920–6.
101. Davey JP, Santore RF. Complications of periacetabular osteotomy. Clin Orthop Relat Res. 1999 ;363:33–7.
102. Kain MS, Novais EN, Vallim C, Millis MB, Kim YJ. Periacetabular osteotomy after failed hip arthroscopy for labral tears in patients with acetabular dysplasia. J Bone Joint Surg Am. 2011 ;93(Suppl 2):57–61.
103. Yamamoto Y, Ide T, Nakamura M, Hamada Y, Usui I. Arthroscopic partial limbectomy in hip joints with acetabular hypoplasia. Arthroscopy. 2005 ;21(5):586–91.
104. Parvizi J, Bican O, Bender B, Mortazavi SM, Purtill JJ, Erickson J, Peters C. Arthroscopy for labral tears in patients with developmental dysplasia of the hip: a cautionary note. J Arthroplasty. 2009 ;24(6)(Suppl):110–3.
105. Byrd JW, Jones KS. Hip arthroscopy in the presence of dysplasia. Arthroscopy. 2003 ;19(10):1055–60.
106. Kosuge D, Yamada N, Azegami S, Achan P, Ramachandran M. Management of developmental dysplasia of the hip in young adults: current concepts. Bone Joint J. 2013 ;95-B(6):732–7.
107. 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 dysplasia. J Bone Joint Surg Br. 2011 ;93(11):1449–56.
108. Kim KI, Cho YJ, Ramteke AA, Yoo MC. Peri-acetabular rotational osteotomy with concomitant hip arthroscopy for treatment of hip dysplasia. J Bone Joint Surg Br. 2011 ;93(6):732–7.
109. Ross JR, Zaltz I, Nepple JJ, Schoenecker PL, Clohisy JC. Arthroscopic disease classification and interventions as an adjunct in the treatment of acetabular dysplasia. Am J Sports Med. 2011 ;39(Suppl):72S–8S.
110. Domb BG, Stake CE, Lindner D, El-Bitar Y, Jackson TJ. Arthroscopic capsular plication and labral preservation in borderline hip dysplasia: two-year clinical outcomes of a surgical approach to a challenging problem. Am J Sports Med. 2013 ;41(11):2591–8. Epub 2013 Aug 16.
111. Hartofilakidis G, Stamos K, Karachalios T, Ioannidis TT, Zacharakis N. Congenital hip disease in adults. Classification of acetabular deficiencies and operative treatment with acetabuloplasty combined with total hip arthroplasty. J Bone Joint Surg Am. 1996 ;78(5):683–92.
112. Yiannakopoulos CK, Xenakis T, Karachalios T, Babis GC, Hartofilakidis G. Reliability and validity of the Hartofilakidis classification system of congenital hip disease in adults. Int Orthop. 2009 ;33(2):353–8. Epub 2007 Nov 6.
113. Duncan S, Wingerter S, Keith A, Fowler SA, Clohisy J. Does previous osteotomy compromise total hip arthroplasty? A systematic review. J Arthroplasty. 2015 ;30(1):79–85. Epub 2014 Sep 6.
114. Boos N, Krushell R, Ganz R, Müller ME. Total hip arthroplasty after previous proximal femoral osteotomy. J Bone Joint Surg Br. 1997 ;79(2):247–53.
115. Migaud H, Putman S, Berton C, Lefèvre C, Huten D, Argenson JN, Gaucher F. Does prior conservative surgery affect survivorship and functional outcome in total hip arthroplasty for congenital dislocation of the hip? A case-control study in 159 hips. Orthop Traumatol Surg Res. 2014 ;100(7):733–7. Epub 2014 Oct 3.
116. Anwar MM, Sugano N, Masuhara K, Kadowaki T, Takaoka K, Ono K. Total hip arthroplasty in the neglected congenital dislocation of the hip. A five- to 14-year follow-up study. Clin Orthop Relat Res. 1993 ;(295):127–34.
117. Tamegai H, Otani T, Fujii H, Kawaguchi Y, Hayama T, Marumo K. A modified S-ROM stem in primary total hip arthroplasty for developmental dysplasia of the hip. J Arthroplasty. 2013 ;28(10):1741–5. Epub 2013 May 21.
118. Davlin LB, Amstutz HC, Tooke SM, Dorey FJ, Nasser S. Treatment of osteoarthrosis secondary to congenital dislocation of the hip. Primary cemented surface replacement compared with conventional total hip replacement. J Bone Joint Surg Am. 1990 ;72(7):1035–42.
119. Fredin H, Sanzén L, Sigurdsson B, Unander-Scharin L. Total hip arthroplasty in high congenital dislocation. 21 hips with a minimum five-year follow-up. J Bone Joint Surg Br. 1991 ;73(3):430–3.
120. García-Cimbrelo E, Munuera L. Low-friction arthroplasty in severe acetabular dysplasia. J Arthroplasty. 1993 ;8(5):459–69.
121. Eskelinen A, Helenius I, Remes V, Ylinen P, Tallroth K, Paavilainen T. Cementless total hip arthroplasty in patients with high congenital hip dislocation. J Bone Joint Surg Am. 2006 ;88(1):80–91.
122. Bruce WJ, Rizkallah SM, Kwon YM, Goldberg JA, Walsh WR. A new technique of subtrochanteric shortening in total hip arthroplasty: surgical technique and results of 9 cases. J Arthroplasty. 2000 ;15(5):617–26.
123. Krych AJ, Howard JL, Trousdale RT, Cabanela ME, Berry DJ. Total hip arthroplasty with shortening subtrochanteric osteotomy in Crowe type-IV developmental dysplasia. J Bone Joint Surg Am. 2009 ;91(9):2213–21.
124. Park MS, Kim KH, Jeong WC. Transverse subtrochanteric shortening osteotomy in primary total hip arthroplasty for patients with severe hip developmental dysplasia. J Arthroplasty. 2007 ;22(7):1031–6.
125. Makita H, Inaba Y, Hirakawa K, Saito T. Results on total hip arthroplasties with femoral shortening for Crowe’s group IV dislocated hips. J Arthroplasty. 2007 ;22(1):32–8.
126. Nötzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg Br. 2002 ;84(4):556–60.
127. Zweifel J, Hönle W, Schuh A. Long-term results of intertrochanteric varus osteotomy for dysplastic osteoarthritis of the hip. Int Orthop. 2011 ;35(1):9–12. Epub 2009 Sep 12.
128. Zaoussis AL, Adamopoulos G, Geraris G, Manoloudis M, Galanis I. Osteotomy for osteoarthritis of the hip. A clinical and radiological survey. Int Orthop. 1984;7(4):223–8.
129. Wright JG, Einhorn TA, Heckman JD. Grades of recommendation. J Bone Joint Surg. 2005 ;87(9):1909–10.
Copyright 2016 by The Journal of Bone and Joint Surgery, Incorporated