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The Legg–Calve–Perthes disease (LCPD) is a rare pathology with an incidence of 4–32 cases per 100 000 but represents one of the most common causes of permanent femoral head deformity in childhood [1]. Almost 30–50% of the affected patients will develop progressive osteoarthritis (OA) in adulthood [2]. Early conservative surgery aims to minimize the femoral head deformity and, in case, the acetabular orientation, to try to reduce the risk of secondary OA [1]. The indications for an effective containment surgery are still being debated, with uncertain predicting factors for the outcomes. In recent times, the ability to safely perform a surgical dislocation of the hip (SHD) has revolutionized the potential of the treatment of LCPD sequelae [2]. Different algorithms to approach the functional analysis of the hip deformities and eventually select the appropriate surgical treatment, especially for young patients, have been described [2, 3]. The intracapital osteotomy is the ultimate limit of conservative hip surgery and consists of an intracapsular osteotomy of the femoral head intending to restore its spherical shape [4, 5]. The most significant expected risk of such surgery is certainly avascular necrosis (AVN). Few cases have been described in literature [5–9]. A case of a young lady treated with an intracapital osteotomy and concomitant periacetabular osteotomy (PAO) for severe and incapacitating sequelae of Perthes Disease and tensor fasciae latae aplasia is presented. Unfortunately, this case ended in progressive hip OA requiring a total hip replacement.

BACKGROUND: The Bernese periacetabular osteotomy (PAO) is a widely used technique for the management of acetabular dysplasia and other hip deformities in adolescents and young adults. Originally, the approach was described with a release of both origins of the rectus femoris muscle(1). In the more recently described rectus-sparing approach, both heads remain attached(2,3). It has been proposed that this modification may decrease pain, ease postoperative rehabilitation, and avoid heterotopic ossifications, without limitations of the surgical overview. DESCRIPTION: Both the original and the rectus-sparing approach are modifications of the Smith-Petersen approach. The skin incision and further dissection remain identical in both approaches for the protection of the lateral femoral cutaneous nerve, the osteotomy of the anterior superior iliac spine (or takedown of the inguinal ligament), the exposure of the iliac fossa, and the medial retraction of the abdominal and iliopsoas muscles. In both variants, the further dissection traverses the iliopectineal bursa. In contrast to the original approach, in which the rectus muscle becomes part of the medial flap after releasing both heads, the rectus-sparing approach involves the undetached rectus muscle becoming part of the lateral flap while the medial flap includes the sartorius and iliacus-iliocapsularis muscles. The anterior capsule and deep structures can be accessed through the interval between the rectus femoris and iliopsoas muscles or lateral to the rectus muscle. The remaining surgical steps are again similar in both techniques. According to preference, the surgeon starts with the pubic osteotomy or with the ischial cut first, the latter avoiding additional bleeding from the pubic osteotomy. For the ischial osteotomy, the bone is accessed by making an anteroposterior tunnel between the medial capsule and the iliopsoas tendon anteriorly and between the medial capsule and the obturator externus muscle posteriorly. While the ischial osteotomy is an incomplete separation, the pubic osteotomy is a complete separation. It sections the superior pubic ramus medial to the iliopectineal eminence, in a somewhat oblique fashion. The third and fourth cuts are made in the iliac bone in such a way as to keep the posterior column intact. By connecting the posterior iliac and ischial cuts as the last osteotomy step, the acetabulum is freed and repositioned as needed. The aim of our cadaver dissection is primarily to describe part of the rectus-sparing approach and to test this modification for eventual disadvantages over the classic approach. The remaining steps of the procedure correspond to the approach as described earlier(1,4), appreciating that several modifications of the procedure are in use. ALTERNATIVES: Nonsurgical treatment may be an alternative in borderline dysplasia; however, it needs to be reconsidered and eventually changed to surgical treatment when symptoms persist or come back. Other current techniques for surgical treatment of adolescent and adult hip dysplasia include triple and rotational or spherical osteotomies(5-7). RATIONALE: The Bernese PAO is performed through a single incision. All cuts are performed from the inner side of the pelvis, avoiding interference with the vascularity of the acetabular and periacetabular bone, which mainly comes from the outside of the pelvis(8). The procedure needs minimal hardware for fixation, and partial weight-bearing can be allowed. The PAO provides a wide range of acetabular reorientation options. Wide capsulotomy and intra-articular procedures are possible, as well as additional femoral corrections. Childbirth via natural delivery is possible even after bilateral PAO(9). Nerve injuries can be guarded against with careful surgical execution of the osteotomies(4).

AimsFemoroacetabular impingement (FAI) describes abnormal bony contact of the proximal femur against the acetabulum. The term was first coined in 1999; however what is often overlooked is that descriptions of the morphology have existed in the literature for centuries. The aim of this paper is to delineate its origins and provide further clarity on FAI to shape future research.MethodsA non-systematic search on PubMed was performed using keywords such as “impingement” or “tilt deformity” to find early anatomical descriptions of FAI. Relevant references from these primary studies were then followed up.ResultsAlthough FAI has existed for almost 5,000 years, the anatomical study by Henle in 1855 was the first to describe it in the literature. The relevance of the deformity was not appreciated at the time but this triggered the development of further anatomical studies. Parallel to this, Poland performed the first surgical correction of FAI in 1898 and subsequently, descriptions of similar procedures followed. In 1965, Murray outlined radiological evidence of idiopathic cam-type deformities and highlighted its significance. This led to a renewed focus on FAI and eventually, Ganz et al released their seminal paper that has become the foundation of our current understanding of FAI. Since then, there has been an exponential rise in published literature but finding a consensus, especially in the diagnosis of FAI, has proven to be difficult.ConclusionCurrent research on FAI heavily focuses on new data, but old evidence does exist and studying it could be equally as important in clarifying the aetiology and classification of FAI. Cite this article: Bone Joint Res 2020;9(9):572–577.

Using an extended retinacular flap containing the blood supply for the femoral head, proximal femur osteotomies can be performed at the neck level increasing the potential of correction of complex morphologies. The aim of this study was to analyze the safety, clinical, and radiographic results of this intra-articular surgical technique performed in skeletally mature patients with a minimum follow-up of three years. Fourteen symptomatic adult patients (16 hips) with a mean age of 26 years underwent FNO using surgical hip dislocation and an extended soft tissue flap. Radiographs and radial magnetic resonance imaging (MRI) were obtained before and after surgery to evaluate articular congruency, cartilage damage, and morphologic parameters. Clinical functional evaluation was done using the Nonarthritic Hip Score (NAHS), the Hip Outcome Score (HOS), and the modified Harris Hip Score (mHHS). After surgery, no avascular necrosis was observed, and all the osteotomies healed without complication. The initial neck/shaft angle (range 120 to 150°) improved in all cases to a mean value of 130° ± 4.6 (p < 0.001). In eight of nine valgus hips, the high-positioned fovea capitis changed to a normal position after surgery. The NAHS score improved from a mean of 36.5 ± 14.9 to 82.9 ± 13.9 points after surgery (p < 0.001). After surgery, the mean HOS was 87.1 ± 17.6 points, and the mean mHHS was 78.6 ± 17 points. In this series, femoral neck osteotomy in the adult, although technically more demanding compared with other classic osteotomies, can be considered a safe procedure with considerable potential to correct hip deformities.

Objectives The purpose of this study was to report (1) a different but specific pattern of impingement in hips involved with valgus slipped capital femoral epiphysis (valgus SCFE) and (2) the results of surgical treatment using intracapsular realignment techniques. Design Case series. Setting Multiple academic centers. Patients Six patients with 8 involved hips referred for valgus alignment of proximal femoral epiphysis (valgus SCFE). Intervention Intracapsular realignment osteotomy combined with periacetabular osteotomy if needed. Main outcome measurement The clinical and radiographical results and pathophysiology of motion. Results Eight hips in 6 patients were treated with subcapital (5 hips) or femoral neck (3 hips) osteotomy for realignment. The medially prominent metaphysis created an inclusive impingement at the anterior acetabular wall, whereas the high coxa valga favored impacting impingement at the posterior head-neck junction. The mean preoperative epiphyseal-shaft angle of 110.5 (range 90-125 degrees) was reduced to 62 degrees (range 55-70 degrees) postoperatively. At the last follow-up, all but 1 hip were pain-free and impingement-free, with normal range of motion. One hip was replaced after repeated attempts of correction. The overall hip functional result using modified Merle d'Aubigne scoring system was excellent in 5 hips (18-16 points), good in 2 hips (16-15 points), and poor in 1 hip (6 points). Conclusions Impingement in valgus SCFE deformity is specific and complex. Anatomical realignment can lead to favorable results by the restoration of normal morphology and impingement-free range of motion. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

New pathophysiological insights Based on improved knowledge of the vascular supply of the proximal femur, a safe surgical dislocation of the hip joint was established allowing direct insights to the pathomorphological malfunctioning of the joint. One insight was that slipped capital femoral epiphysis (SCFE) impingement leads to substantial damage of the chondrolabral rim area, even in the presence of minor slips. A further surgical development was the extended retinacular flap allowing for correction of the deformity with calculable risk for iatrogenic necrosis. Consecutive surgical concept In 20 years of experience, a treatment concept for SCFE could be established which replaces classic pinning in situ and indirect correction of the deformity with subcapital re-alignment when the physis is still open, with true femoral neck osteotomy for hips with closed physis. Pinning in situ still has a place in minor slips but should be combined with open or arthroscopic recreation of an anterior metaphyseal waisting. Unexpected complication Loss of joint stability is a rare complication of anatomic re-alignment. It can be disease-related when the impingement has induced severe destruction of acetabular cartilage. It can be related to the surgical procedure, especially when the neck was excessively shortened and refixation of the trochanter was not advanced. Finally, in cases with severe and long-lasting deformity, the acetabulum may undergo adaptive flattening, being the cause of joint destabilisation with the correction of the deformity. Advancement of the greater trochanter and/or peri-acetabular osteotomy may be discussed to restabilise the joint.

The goal of femoroacetabular impingement (FAI) treatment is restoration of normal hip function by removing pathomechanic deformities. The efficacy of surgical treatment has been demonstrated for both arthroscopic and open surgery. While isolated insufficient waist of the head–neck junction ± localized acetabular overcover is the domain of arthroscopy, open surgery with hip dislocation is indicated in more global deformities, as well as when additional axial corrections and/or trochanteric advancement are necessary. Surgical dislocation of the hip is a safe approach with low risk of avascular necrosis and little morbidity; it provides complete visualization of the acetabular cavity and of the femoral head surface. When needed, it can be extended to the proximal femur. When additional periacetabular osteotomy is indicated, the first ischial cut can be executed through the approach.

Background Redislocation of the native hip is rare. An anterior fulcrum between the proximal part of the femur and the pelvis must be present for a posterior dislocation to occur. The purpose of this study is to describe the cases of 9 patients with posterior redislocation or recurrent subluxation of the native hip that was treated with hip preservation surgery. Methods We retrospectively identified the cases of 9 patients, from 2 institutions, who had undergone hip preservation surgery for the management of posterior redislocation or recurrent subluxation of the native hip after a dislocation. The mean number of dislocations prior to surgery was 3.2 (range, 1 to 7). Pelvic radiographs were used to classify the acetabular morphology, sufficiency of acetabular containment, and structural anatomy of the proximal part of the femur. Radiographic identification of impinging structures was used to guide surgical treatment, which involved either femoral correction alone or the combination of femoral correction and an anteverting periacetabular osteotomy. Results At a mean follow-up of 73.8 months (range, 10 to 192 months), there had been no subsequent episodes of dislocation or subluxation in any of the hips treated with correction of the anatomic pivot point. An algorithmic approach is presented. Conclusions In patients who have episodes of redislocation or recurrent subluxation of the native hip, the identification of anatomic abnormalities that create a fulcrum between the proximal part of the femur and the pelvis is critical for making appropriate treatment decisions. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Zusammenfassung: Das femoroazetabuläre Impingement (FAI) ist häufig, die geschätzte Prävalenz liegt bei 10-15%. Unsere bisher 10-jährige Erfahrung bestätigt das FAI als eine wesentliche, wenn auch nicht einzige Ursache der Koxarthrose. Isolierte azetabuläre oder femorale Fehlformen sind selten, obwohl bei Frauen die azetabuläre und bei Männern die femorale Pathomorphologie dominiert. Normalbefunde im Standardröntgen schließen ein FAI nicht aus. Symptome treten umso früher auf, je größer die Deformität und je intensiver hohe Bewegungsanforderungen gestellt werden. Die überwiegende Mehrzahl der Patienten ist

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, even metal ring or cage in association showed poor long-term outcome. To promote allograft bone consolidation and acetabular stability, we have ass

Missed torsional femur deformities may contribute to reasons for failure after open and more likely arthroscopic hip preservation surgery. A number of surgical approaches have been described for addressing torsion abnormalities. This report describes a subtrochanteric osteotomy technique in a consecutive series of patients with complex hip pathologies, for which intertrochanteric osteotomy is not suitable and precise derotation is required. Subtrochanteric derotation was performed, always in combination with a surgical hip dislocation, in accordance with the authors’ preferred technique. Before osteotomy, a localized decortication was executed. Application of a 4.5-mm broad or narrow plate was undertaken with dynamic compression of the osteotomy. Twenty-eight consecutive subtrochanteric derotational osteotomies were performed in 26 patients. Twenty-one females and five males were treated at an average age of 21.4 years (range, 12–43). Underlying diagnoses included dysplasia, arthrogryposis, cerebral palsy, Down’s syndrome, instability and impingement. The decision to perform derotation was for antetorsion over 20 � or less than 0 � (retrotorsion). Patients were followed clinically and radiographically till final follow-up. All patients went on to successful osteotomy union. There were two initial failures: one delayed union prompting revision fixation in a chronic smoker and one plate failure due to self-accelerated weight-bearing in a patient status post successful contralateral derotational osteotomy. Rotational deformity of the femur must be considered in the patient undergoing hip preservation surgery. This technique of subtrochanteric derotational osteotomy, with adjunctive surgical hip dislocation, is applicable and reproducible in the setting of complex hip pathologies. Level of evidence: IV, case series.

Case: An eighteen-year-old woman was referred to our center because of left groin pain and was diagnosed with acetabular dysplasia. The proposed treatment was a Bernese periacetabular osteotomy (PAO). The patient had undergone two renal transplants due to polycystic kidney disease; the current, functional kidney was at the lateral inguinal fossa on the left side. The patient was on chronic immunosuppressants and antihypertensive therapy. Conclusion: The present case shows that PAO can be a safe procedure with good outcomes even in patients who have undergone renal transplantation.

Case: We present the case of a fourteen-year-old male athlete with a slipped capital femoral epiphysis who was managed with a unilateral Dunn procedure and contralateral prophylactic screw fixation. Even though the cartilaginous epiphyseal growth plate was removed on one side, cam deformities subsequently developed on both sides in the postoperative period. Conclusion: This case suggests that structures other than the growth plate are also capable of inducing cam deformity of the hip.

To the best of our knowledge, the concept of femoroacetabular impingement (FAI) as a cause of hip pain in young adults was introduced in the last decade1. Since then, abnormal osseous morphology has been increasingly recognized as a cause of early primary hip arthrosis2. Approximately 90% of all patients with hip pain and labral pathology have underlying osseous abnormalities3,4. The prevalence of asymptomatic FAI morphology in young men, however, is approximately 25%5. Thus, other causes of hip pain should be considered, particularly when atypical features are present during the evaluation of a young patient with symptoms around the hip. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. An eighteen-year-old patient presented with steadily worsening right groin pain over the course of a year. Symptoms increased when he participated in sports and, progressively, occurred at night. Most pain medications, including nonsteroidal anti-inflammatories, had little effect. Prior to referral to our clinic, the patient had a standard anteroposterior pelvic radiograph, a pelvic magnetic resonance image (MRI), and an MR arthrogram, ostensibly demonstrating a decreased anterior femoral head-neck offset. Bone marrow edema in the femoral neck seen on the pelvic MRI was interpreted as reactive (Fig. 1). He was given the probable diagnosis of FAI and referred to our clinic for additional evaluation. Fig. 1 Pelvic MRI (coronal view) demonstrating bone marrow edema in the right femoral neck (arrowhead). On examination, the patient demonstrated a mild start-up limp that resolved quickly. Hip flexion, adduction, and internal rotation produced pain, as did palpation of the rectus femoris origin. Hip internal rotation was limited to 0° in 90° of flexion, as compared with 30° of internal rotation on the contralateral side. In all other planes, hip motion …

Proximal femoral fracture and coxarthrosis are the most common orthopaedic problems of osteopetrosis. Fracture fixation is difficult and one-third fail, with total hip replacement as the final solution. There is little reported experience about how to deal with this particular type of bone and what has been published to date is surprisingly non-specific. Corrective osteotomies are mainly undertaken in children for non-union of a fractured femoral neck and/or for coxa vara. However, any information about technical problems and solutions is scarce and barely instructive. Osteotomy experience for osteopetrosis in youngsters and young adults has not been reported. Osteopetrosis bone is characterized by a small tolerance for displacement and by the high friction experienced when penetrating instruments and implants are used. This article describes the risks of hip surgery in the presence of osteopetrosis and also discusses osteotomies around the hip and how to limit any related complications. Four patients, who underwent different types of hip preservation procedure, have been used to illustrate the difficulties that can be encountered. The article also suggests ways to make osteotomies feasible in osteopetrosis bone, even in adults.

Traditionally arthrotomy has rarely been performed during surgery for slipped capital femoral epiphysis (SCFE). As a result, most pathophysiological information about the articular surfaces was derived clinically and radiographically. Novel insights regarding deformity-induced damage and epiphyseal perfusion became available with surgical hip dislocation.We (1) determined the influence of chronicity of prodromal symptoms and severity of SCFE deformity on severity of cartilage damage. (2) In surgically confirmed disconnected epiphyses, we determined the influence of injury and time to surgery on epiphyseal perfusion; and (3) the frequency of new bone at the posterior neck potentially reducing perfusion during epimetaphyseal reduction.We reviewed 116 patients with 119 SCFE and available records treated between 1996 and 2011. Acetabular cartilage damage was graded as +/++/+++ in 109 of the 119 hips. Epiphyseal perfusion was determined with laser-Doppler flowmetry at capsulotomy and after reduction. Information about bone at the posterior neck was retrieved from operative reports.Ninety-seven of 109 hips (89%) had documented cartilage damage; severity was not associated with higher slip angle or chronicity; disconnected epiphyses had less damage. Temporary or definitive cessation of perfusion in disconnected epiphyses increased with time to surgery; posterior bone resection improved the perfusion. In one necrosis, the retinaculum was ruptured; two were in the group with the longest time interval. Posterior bone formation is frequent in disconnected epiphyses, even without prodromal periods.Addressing the cause of cartilage damage (cam impingement) should become an integral part of SCFE surgery. Early surgery for disconnected epiphyses appears to reduce the risk of necrosis. Slip reduction without resection of posterior bone apposition may jeopardize epiphyseal perfusion.Level IV, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.

The analysis and treatment of hips with healed Legg-Calvé-Perthes disease (LCPD) differs substantially from the treatment in the acute phase of the disease. More specifically, the treating orthopaedic surgeon is often faced with a complex three-dimensional pathomorphology of the hip that is difficult to understand and correct. To date, none of the current classification systems provide a useful decision-making algorithm with regards to the type of surgical intervention necessary to improve hip function in patients with sequelae of LCPD. The conceptual recognition of the femoroacetabular impingement (FAI) and the ability to safely dislocate the hip have revolutionised our diagnostic and therapeutic algorithm for joint-preserving surgery of hips with structural residuals of LCPD. We present a systematic approach to analyse femoral and acetabular pathomorphologic features. The resulting pathomechanisms and the surgical treatment options are presented.

Introduction With excessive acetabular coverage, such as coxa profunda or protrusio, contact between the femoral neck and acetabular rim cause direct damage to the labrochondral junction, and indirect edge loading from a levering effect which may result in hip arthrosis. Arthrosis may be delayed or avoided by addressing the overcoverage and restoring mechanical function of the labrum. We describe four cases of adjunctive complete acetabular labral replacement for circumferential, irreparable labral injury using fresh frozen semitendinous allografts through surgical hip dislocation. Materials and Methods Over a two-year period four patients (age range: 20 to 47 years) underwent surgical hip dislocation to address femoroacetabular impingement with rim trimming, femoral osteochondroplasty, and labral reconstruction. Pre- and postoperative patient reported outcomes were assessed by Oxford Hip Score (OHS), Hip Outcome Score (HOS), and Global Treatment Outcome (GTO) score. Disease progression was graded using AP pelvic radiographs and arthroMR. Results The average LCE correction was 18° (range 7-25°), achieving an average LCE of 33° (range 32-35) postoperatively. Using protected weight bearing all trochanteric osteotomies healed within six weeks after surgery. OA did not progress in any hips. Mean OHS and HOS scores improved 6.3 and 19.8 at one-year follow up. All four patients reported good results according to the GTO. There were two adverse events that resolved and did not affect outcome. Summary and Conclusions Despite complex deformities and preexisting cartilage and labrum wear in this young cohort, three of four patients reported significant functional improvement after treatment of this rare condition. Preliminary experience with circumferential labral reconstruction using hamstring allografts is promising, although long-term data needs to be established.

BACKGROUND Traumatic posterior hip dislocation in adults is generally understood to be the result of a high-energy trauma. Aside from reduced femoral antetorsion, morphologic risk factors for dislocation are unknown. We previously noticed that some hips with traumatic posterior dislocations had evidence of morphologic features of femoroacetabular impingement (FAI), therefore, we sought to evaluate that possibility more formally. QUESTIONS/PURPOSES We asked whether hips with a traumatic posterior hip dislocation present with (1) a cam-type deformity and/or (2) a retroverted acetabulum. METHODS We retrospectively compared the morphologic features of 53 consecutive hips (53 patients) after traumatic posterior hip dislocation with 85 normal hips (44 patients) based on AP pelvic and crosstable axial radiographs. We measured the axial and the lateral alpha angle for detection of a cam deformity and the crossover sign, ischial spine sign, posterior wall sign, retroversion index, and ratio of anterior to posterior acetabular coverage to describe the acetabular orientation. RESULTS Hips with traumatic posterior traumatic dislocation were more likely to have cam deformities than were normal hips, in that the hips with dislocation had increased axial and lateral alpha angles. Hips with posterior dislocation also were more likely to be retroverted; dislocated hips had a higher prevalence of a positive crossover sign, ischial spine sign, and posterior wall sign, and they had a higher retroversion index and increased ratio of anterior to posterior acetabular coverage. CONCLUSIONS Hips with posterior traumatic dislocation typically present with morphologic features of anterior FAI, including a cam-type deformity and retroverted acetabulum. An explanation for these findings could be that the early interaction between the aspherical femoral head and the prominent acetabular rim acts as a fulcrum, perhaps making these hips more susceptible to traumatic dislocation.

Acetabular retroversion following acetabular osteotomy in hips with dysplasia can negatively effect the outcome. Total retroversion, where the entire anterior rim is lateral to the posterior rim, is rare and can easily be missed on pelvic radiographs due to the lack of a crossover sign. We evaluated the clinical and radiographic presentation, the surgical management, and the outcome of hips with total acetabular retroversion. We retrospectively reviewed 26 patients (26 hips) with total retroversion following 15 periacetabular osteotomies (PAO) (1), 10 triple type, and one Salter osteotomy (2). We obtained range of motion (ROM), anterior impingement test, Drehmann's sign, Merle d'Aubigné-Postel score, and Tönnis score for osteoarthrosis. Corrective surgery included 19 revision PAOs and seven total hip arthroplasties (THA). The mean follow-up was 4.7 ± 4.2 (range 0.5-13.8) years. Patients presented with a restricted ROM (flexion and internal rotation), a positive anterior impingement test, a positive Drehmann's sign, and a decreased Merle d'Aubigné-Postel score due to pain. Corrective surgery was performed after mean of 7 ± 5 (1-15) years. Complications for revision PAO and THA occurred in 37% and 29%, respectively. At follow-up, the Merle d'Aubigné-Postel score improved for both revision PAOs and THAs. The prevalence of a positive anterior impingement test and Drehmann's sign decreased for revision PAOs. There was a tendency for progression of OA in hips with revision PAO. Iatrogenic total acetabular retroversion following reorientation is a disabling condition for the patients. Corrective surgery including revision PAO and THA results in improved clinical outcome. However, these procedures are technically challenging and associated with high complication rates.

Aims Several studies have reported the safety and efficacy of subcapital re-alignment for patients with slipped capital femoral epiphysis (SCFE) using surgical dislocation of the hip and an extended retinacular flap. Instability of the hip and dislocation as a consequence of this surgery has only recently gained attention. We discuss this problem with some illustrative cases. Materials and Methods We explored the literature on the possible pathophysiological causes and surgical steps associated with the risk of post-operative instability and articular damage. In addition, we describe supplementary steps that could be used to avoid these problems. Results The causes of instability may be divided into three main groups: the first includes causes directly related to SCFE (acetabular labral damage, severe abrasion of the acetabular cartilage, flattening of the acetabular roof and a bell-shaped deformity of the epiphysis); the second, causes not related to the SCFE (acetabular orientation and poor quality of the soft tissues); the third, causes directly related to the surgery (capsulotomy, division of the ligamentum teres, shortening of the femoral neck, pelvi-trochanteric impingement, previous proximal femoral osteotomy and post-operative positioning of the leg). Conclusion We present examples drawn from our clinical practice, as well as possible ways of reducing the risks of these complications, and of correcting them if they happen. Cite this article: Bone Joint J 2017;99-B:16–21.

A 16-year-old boy sustained a traumatic posterior dislocation of the right hip. After initial closed reduction, the hip spontaneously redislocated within 2 days. Four days after the initial dislocation, the patient was transferred to the authors' institution, where a radiographic workup showed a severe capsular and labral disruption from the posterior aspect of the acetabulum. Subsequently, the patient underwent operative treatment using the technique of surgical hip dislocation through a digastric osteotomy as described by Ganz. Using this approach, the avulsed capsulolabral complex as well as the pathological head-neck junction, which is suspected to be a lever for the femoral head, could be fully addressed. The authors recommend further radiographic studies to evaluate the underlying pathology in traumatic dislocation of the hip as well as the described surgical approach, which leads to successful treatment of the entire pathology.

Controversies exist regarding the best treatment for slipped capital femoral epiphysis (SCFE). Subcapital anatomical reorientation of the epiphysis by surgical dislocation and a retinacular soft tissue flap has been described recently as an effective approach. We evaluated the clinical and radiographic efficacy of this technique and compared these to published results. A series of 20 SCFE (18 stable, 2 unstable) treated by subcapital re-orientation through surgical hip dislocation and an extended retinacular soft tissue flap was reviewed retrospectively. Preoperatively and at most recent follow-up, patients were clinically examined with regard to pain and function according to the Harris hip score and to the Western Ontario and McMaster universities (WOMAC) score. Radiological examination included measurement of preoperative and postoperative anteroposterior (AP) and lateral (L) Southwick angles; and at follow-up the alpha angle was measured. The average follow-up time was 24 months. The mean WOMAC score was 2.80 post-operatively. The mean pre-operative slip angle was 40.2 degrees on the AP view and 50.65 degrees on the lateral view. Post-operatively, the mean values were 7,20 degrees on the AP view and 9,45 degrees on the lateral view. The mean post-operative average alpha angle was 43,11 degrees. No cases of avascular necrosis were seen. Our short term clinical and radiographic results are similar to outcomes published in the recent literature. The small number of technical complications appears favourable considering the surgical complexity of the procedure, and our technique offers clear advantages in treating these complex deformities.

Purpose To study the arthroscopic appearance and treatment of impingement cysts and to propose their potential intraoperative value for correct femoral osteochondroplasty in femoroacetabular impingement (FAI). Methods We performed a single-surgeon, retrospective study of 152 consecutive hip arthroscopies in 141 patients treated for FAI due to cam, localized pincer, or mixed FAI. Radiographic (conventional radiographs and magnetic resonance arthrography) cyst sizes and locations as well as the arthroscopic appearance were recorded. Results On the preoperative radiographs, impingement cysts were radiographically visible in 18% of treated FAI patients (26 of 141); 15% of these patients (4 of 26) had more than 1 cyst. Age was the only independent predictor of cysts, with a 7-year shift to a mean age of 42 years. The majority of cysts were located in the anterosuperior quadrant of the femoral head-neck junction (93%), the mean diameter of cysts was 7.0 mm, with a range from 3.7 to 15.1 mm. During surgery, only a few were arthroscopically identifiable, with a pit-like (3 of 26) or crater-like appearance (3 of 26) (i.e., surface alterations) for the larger cysts. The majority of cysts (20 of 26) became evident, however, after unroofing of the area of cam FAI. Cysts were associated with labral (25 of 26) and/or chondral lesions (23 of 26). Small cysts were completely removed during femoral osteochondroplasty, whereas larger cysts were only resected until impingement-free range of motion was reached. No neck fractures occurred in this series. Conclusions Impingement cysts were present on 1 in 6 radiographs in patients undergoing hip arthroscopy for FAI and were found most commonly in older patients. The cysts predictably occur within the epicenter of the femoral-induced impingement. Whereas surface alterations are rare (6 of 26), the content and base of the unroofed cyst are consistent. Most cysts are completely excised as part of the femoral impingement correction and may be used as a confirmation that arthroscopic cam resection has been performed at the correct site. Level of Evidence Level IV, therapeutic case series.

Objective Femoroacetabular impingement may be a risk factor for hip osteoarthritis in men. An underlying hip deformity of the cam type is common in asymptomatic men with nondysplastic hips. This study was undertaken to examine whether hip deformities of the cam type are associated with signs of hip abnormality, including labral lesions and articular cartilage damage, detectable on magnetic resonance imaging (MRI). Methods In this cross-sectional, population-based study in asymptomatic young men, 1,080 subjects underwent clinical examination and completed a self-report questionnaire. Of these subjects, 244 asymptomatic men with a mean age of 19.9 years underwent MRI. All MRIs were read for cam-type deformities, labral lesions, cartilage thickness, and impingement pits. The relationship between cam-type deformities and signs of joint damage were examined using logistic regression models adjusted for age and body mass index. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined. Results Sixty-seven definite cam-type deformities were detected. These deformities were associated with labral lesions (adjusted OR 2.77 [95% CI 1.31, 5.87]), impingement pits (adjusted OR 2.9 [95% CI 1.43, 5.93]), and labral deformities (adjusted OR 2.45 [95% CI 1.06, 5.66]). The adjusted mean difference in combined anterosuperior femoral and acetabular cartilage thickness was −0.19 mm (95% CI −0.41, 0.02) lower in those with cam-type deformities compared to those without. Conclusion Our findings indicate that the presence of a cam-type deformity is associated with MRI-detected hip damage in asymptomatic young men.

Background: Hips with coxa profunda can develop a pincer-type impingement with linear impact between the proximal part of the femur and the acetabulum, leading to bone apposition on the acetabular rim. Methods: Twenty hips with radiographic features of rim ossification were isolated from a pilot cohort of 220 patients for histologic assessment of the acetabular rim and the labrum. In the second part of the study, the prevalence of radiographic signs of bone apposition in a cohort of 148 hips treated for femoroacetabular impingement was assessed. Results: Histologic analysis confirmed that the labrum may become displaced and replaced by the appositional bone formation. The double-line sign and the recess sign are suggestive of an ongoing process of this bone formation, and the described phenotypes of bone apposition indicate the site of the impingement problem. Morphological anomalies of the proximal part of the femur, such as a low neck-shaft angle or a short femoral neck, may further contribute to the mechanism of pincer impingement. Conclusions: In later stages, this bone formation cannot be distinguished from the native bone and the labrum may appear to be nearly absent on imaging studies. While the bone apposition on the rim is first reactive to chronic impingement, the impingement then increases and may lead to further bone apposition.

Successful treatment of femoroacetabular impingement requires thorough knowledge of the impingement spectrum and precision in diagnosis. Substantial information may escape when not routinely using high-quality arthro-MRI including radial sequences. Early recognition of FAI is essential. It has to be followed by behavioral modification and even surgical treatment to eventually reduce or postpone osteoarthritis due to impingement. Physical therapy or pharmaceutical medication cannot influence the pathomechanical process or the adverse influence on the hip joint. Surgical treatment should be technically feasible and the benefit for the patient foreseeable. Open and arthroscopic techniques are not competitive; they should be applied according to the pathology rather than the surgeon’s preference.We describe here the indication and techniques of open surgery for impingement hips with rather complex pathology, the workhorse for most procedures being surgical dislocation and the extended retinacular soft tissue flap.

Background: Poliomyelitis results in a flaccid paralysis of muscles that can lead to hip instability. The objective of this study was to determine the results of the Bernese periacetabular osteotomy in patients with paralytic hips secondary to poliomyelitis. Methods: Nine patients who had a Bernese periacetabular osteotomy were identified as having paralytic hip dysplasia secondary to poliomyelitis. All patients had hip pain and instability at the time of presentation. Clinical records and radiographs were reviewed. One patient did not return for physical examination at last follow-up. Results: The mean length of follow-up was 103 months. All patients had a decrease in the severity of pain but less improvement in function, as hip abductor muscle strength was improved in only two of the eight patients examined. The average postoperative Harris hip score was 80.2. All patients had an improvement in the extrusion index, the acetabular index, and the lateral center-edge angle. According to the Tonnis radiographic classification, three patients progressed from Grade 0 to Grade 1 and one patient progressed from Grade 1 to 2. Conclusions: The correction obtained with use of the Bernese periacetabular osteotomy provides containment of the hip joint in patients with hip dysplasia secondary to poliomyelitis. The patients had a decrease in the severity of pain and less improvement in function. The results have been long-lasting and may have slowed the progression of osteoarthritis of the hip. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

We present a case of epiphyseal reperfusion in a 12-year-old boy following subcapital realignment of a unstable slipped capital femoral epiphysis. The case demonstrates that even if delayed, anatomical surgical realignment of the femoral head can be successful in preserving or reestablishing blood flow to the femoral epiphysis.

OBJECTIVE: To determine the performance of a newly developed examination chair as compared with the clinical standard of assessing internal rotation (IR) of the flexed hip with a goniometer. METHODS: The examination chair allowed measurement of IR in a sitting position simultaneously in both hips, with hips and knees flexed 90 degrees, lower legs hanging unsupported and a standardized load of 5 kg applied to both ankles using a bilateral pulley system. Clinical assessment of IR was performed in supine position with hips and knees flexed 90 degrees using a goniometer. Within the framework of a population-based inception cohort study, we calculated inter-observer agreement in two samples of 84 and 64 consecutive, unselected young asymptomatic males using intra-class correlation coefficients (ICC) and determined the correlation between IR assessed with examination chair and clinical assessment. RESULTS: Inter-observer agreement was excellent for the examination chair (ICC right hip, 0.92, 95% confidence interval [CI] 0.89-0.95; ICC left hip, 0.90, 95% CI 0.86-0.94), and considerably higher than that seen with clinical assessment (ICC right hip, 0.65, 95% CI 0.49-0.77; ICC left hip, 0.69, 95% CI 0.54-0.80, P for difference in ICC between examination chair and clinical assessment

Protrusio acetabuli is identified on anteroposterior (AP) radiographs of the pelvis with an acetabular line projecting medial to the ilioischial line. We documented this radiographic sign and additional radiographic parameters in 19 patients (29 hips) with protrusio and compared the parameters to those of 29 older patients (29 hips) with advanced primary osteoarthritis (OA) but no protrusio and 12 younger patients (22 hips) with protrusio but no advanced OA. A negative acetabular roof angle and particularly large acetabular fossa were more apparent in younger patients; these hips suggest the destruction of a protrusio hip begins less in the medial joint area and more in the posteroinferior joint, and the mechanism is driven less by excessive medially directed forces but by a pincer impingement. While the indication for joint-preserving surgery currently consists primarily of a valgus femoral osteotomy based on AP radiographs and patient age, modern decision making also relies on cartilage evaluation and requires advanced surgical techniques. We conclude joint-preservation surgery must be tailored to the individual hip morphology.

Background: Capsular and pericapsular vessels are believed to contribute to acetabular and femoral head perfusion, but, to our knowledge, there is no anatomic study to support this theory. The purpose of this study was to describe the vascular anatomy of the hip with particular reference to the contributions of the capsular and pericapsular vessels. Methods: Twenty fresh cadavers were dissected twenty-four hours after intra-arterial injection of colored silicone. The arteries supplying the hip were followed by careful dissection from their origins outside the pelvis to their terminal branches. Particular attention was paid to the vessels traveling between the acetabulum and the capsule and the femoral head. Results: In all twenty specimens, the hip capsule received blood supply from the superior and inferior gluteal arteries proximally and from the medial and lateral femoral circumflex arteries distally. The contributory vessels entered the capsule peripherally and superficially. The circumflex arteries supplied the anterior capsule. The gluteal arteries supplied the posterior and posterosuperior aspect of the hip capsule, augmented by contributions from the circumflex arteries. Variable anastomoses were found between the gluteal and femoral systems on the capsular surface beneath the gluteus minimus and short hip external rotators. The medial femoral circumflex artery provided the dominant blood supply to the femoral head in eighteen specimens, and the inferior gluteal artery provided the dominant supply in two specimens. Conclusions: Capsular and pericapsular vessels that contribute to the blood supply of the acetabulum run on the posterior and posterolateral surface of the capsule. The dominant blood supply to the femoral head comes from vessels that approach the joint posteriorly and penetrate the joint near the femoral attachment of the capsule. Clinical Relevance: Surgical approaches to the hip that separate the gluteus minimus and short hip external rotators from the capsule may interfere with the blood supply of the acetabulum and femoral head. Certain arthroscopic approaches may also place these vascular structures at risk.

As a distinct entity, femoroacetabular impingement has been suggested to be a preosteoarthritic mechanism. The condition occurs when the proximal femur repeatedly comes into contact with the native acetabular rim during normal hip range of motion. Early diagnosis and surgical management are imperative to delay degenerative changes associated with these conditions. Femoroacetabular impingement is most prevalent in young, active patients. Physical examination should include evaluation of gait and foot progression angle, as well as leg length measurement, hip range of motion, and abductor strength. Imaging studies, including plain radiographs and magnetic resonance arthrography, aid in accurate diagnosis. Surgical treatment options include surgical hip dislocation, periacetabular osteotomy, and hip arthroscopy.

SummaryObjectiveEvaluation of the internal construct validity of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index adapted for use in patients with femoro-acetabular impingement (FAI) and osteoarthritis (OA) of the hip.MethodsDistribution of a German version of WOMAC to patients upon first consultation. Patients with FAI [n=100, mean age 31.7 years, standard deviation (SD) 9.7] and OA (n=57, mean age 60.3 years, SD 11.7) and without comorbidities or prior hip surgery were included and compared to age- and gender-matched control population to FAI (n=200, mean age 32.6 years, SD 5.6). WOMAC data of 157 questionnaires were evaluated by Rasch analysis using RUMM2020 software.ResultsSummation of total WOMAC shows misfit to the Rasch model as well as multidimensionality. While the pain subset shows adequate fit and is unidimensional, item reduction is required to fit a unidimensional subset of functional items to the Rasch model. Summating the two fitting subsets yields again slight model misfit and multidimensionality requiring further item reduction. Finally, a 12-item version of the total WOMAC shows good model fit and unidimensionality, i.e., internal construct validity, for assessment of patients with FAI and OA without differential item functioning (DIF). A person separation index (PSI)=0.93 indicates a high internal consistency reliability for the 12-item subscale. Scores for FAI are significantly higher than control (P

63 slipped capital femoral epiphysis were treated either by a femoral neck osteotomy or by an intertrochanteric osteotomy. In almost all cases a normal anatomical relationship of the proximal capital femoral epiphysis to the neck of the femur was achieved. At an average follow-up of 10 years (2 to 19 years) 90% were rated good to excellent clinically. In 33 hips with a follow-up period of more than 10 years mild degenerative arthritis was present in 36%. Slipping of 60 degrees or less is best treated by an intertrochanteric osteotomy to avoid the higher complication rate in the femoral neck osteotomy.

Femoroacetabular impingement may occur in patients with so-called acetabular retroversion, which is seen as the crossover sign on standard radiographs. We noticed when a crossover sign was present the ischial spine commonly projected into the pelvic cavity on an anteroposterior pelvic radiograph. To confirm this finding, we reviewed the anteroposterior pelvic radiographs of 1010 patients. Nonstandardized radiographs were excluded, leaving 149 radiographs (298 hips) for analysis. The crossover sign and the prominence of the ischial spine into the pelvis were recorded and measured. Interobserver and intraobserver variabilities were assessed. The presence of a prominent ischial spine projecting into the pelvis as diagnostic of acetabular retroversion had a sensitivity of 91% (95% confidence interval, 0.85%–0.95%), a specificity of 98% (0.94%–1.00%), a positive predictive value of 98% (0.94%–1.00%), and a negative predictive value of 92% (0.87%–0.96%). Greater prominence of the ischial spine was associated with a longer acetabular roof to crossover sign distance. The high correlation between the prominence of the ischial spine and the crossover sign shows retroversion is not just a periacetabular phenomenon. The affected inferior hemipelvis is retroverted entirely. Retroversion is not caused by a hypoplastic posterior wall or a prominence of the anterior wall only and this finding may influence management of acetabular disorders. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

The use of fresh osteochondral allografts is a popular approach to treat articular cartilage lesions. Immunological reactions of the recipient elicited by the allograft's osseous portion, however, frequently result in their deterioration. So far, little emphasis has been put on describing morphology and biological activity in fresh allografts and paralleling these to the immunological processes triggered in the host. Therefore, in the present study murine neonatal femora, serving as osteochondral grafts, were transplanted as fresh isografts (controls) or allografts (the latter in non- or presensitized mice) and retrieved after 2, 5, 10, and 20 days. It was shown that (1) in isografts active bone cells (osteoblasts, osteoclasts) were present, the bone marrow was repopulated with hematopoietic cells, the diaphysis increased in length, and no specific immunological reaction by the recipient was evoked. (2) Allografts transplanted into nonsensitized hosts initially appeared similar as isografts, but activated T lymphocytes at the transplantation site preceded loss of active bone cells within the graft and development of fibrosis within the marrow cavity. (3) In allografts transplanted into presensitized recipients, severe deterioration of the graft was observed with very few active bone cells, accompanied by an invasion of T lymphocytes and fibrosis in the marrow cavity already in early stages. Similar to vital organ transplantation, the function of cells within osteochondral allografts is severely impaired after being recognized by the immune system. Therefore, emphasis has to be placed on the development of procedures preserving cartilage biology while reducing the antigenicity of the allograft's osseous portion.

Behandlungsziel einer Epiphyseolysis capitis femoris ist die anatomisch ausgerichtete und normal durchblutete Epiphyse. Die subkapitale Reorientierung oder Schenkelhalskeilosteotomie ermoglicht ein solches Ergebnis. Mit den bisherigen Vorgehensweisen ist die Gefahr einer avaskularen Nekrose nicht unter optimaler Kontrolle. Akute Epiphyseolysen. Chronische Epiphyseolysen, bei denen die Abtragung des metaphysaren Uberstands bis zur impingementfreien Flexion-Innenrotation weniger als zwei Drittel des Schenkelhalsdurchmessers hinterlassen wurde. Ausgepragte Ankylose des Huftgelenks. Zerstorung des Huftkopfs. Mit der chirurgischen Huftluxation und einem Weichteillappen, der subperiostal aus Retinakulum und Ausenrotatoren entwickelt wird, kann die Gefasversorgung der Epiphyse aus der Arteria circumflexa femoris medialis erhalten werden. Dieser Weichteillappen erlaubt eine Losung der Epiphyse sowie eine vollstandige Kallusresektion vom Schenkelhals ohne Spannung des Retinakulums. Die Luxation des Huftkopfs dient dessen manueller Sicherung wahrend der Kurettage der Wachstumsfuge und schlieslich der anatomischen Reposition unter visueller Kontrolle des Retinakulums. Mit luxiertem Kopf wird eine unerwunschte Manipulation am Bein die Integritat des Retinakulums weniger gefahrden, als dies bei in der Pfanne verbliebenem Kopf der Fall ware. 30 Huften wurden zwischen 1996 und 2005 bei der Diagnose einer Epiphyseolysis capitis femoris mit der beschriebenen Technik behandelt. Die mittlere Nachuntersuchungszeit lag bei 55 Monaten (24–96 Monate). Es traten keine Huftkopfnekrosen auf. Es bestand eine ausgeglichene Geschlechtsverteilung. Die Madchen waren zur Operation im Durchschnitt 12 Jahre, die Jungen 14 Jahre alt. Der dorsale Abrutsch wurde zwischen 30° und 70° bemessen. Bei sechs Huften bestand ein sog. „acute on chronic“ Abrutsch. Zwei Huften mussten wegen Schraubenbruchen revidiert werden, eine Problematik, die mit Verwendung von Vollgewindedrahten entscharft wurde. Eine Hufte wurde wegen Verbiegung des Vollgewindedrahts revidiert. Alle drei Huften wiesen eine Verkurzung von maximal 1 cm auf. Bei einem Patienten mit ektoper Ossifikation am ventral-distalen Schenkelhals ist die Innenrotation in Beugung auf die Halfte reduziert.

Athletic activities frequently require extreme hip range of motion, particularly flexion and internal rotation. In patients with an aspherical femoral head or overcoverage of the acetabulum, this motion causes the head–neck junction and acetabular rim to abut, resulting in femoroacetabular impingement (FAI). With time, the repetitive contact of FAI causes activity-related groin pain and structural damage to the hip joint, including cartilage delamination, labral tears, and detachment and eventually the early onset of osteoarthritis. Conservative measures, such as activity modification, are often unsuccessful in ambitious young athletic patients whom wish to compete at a high level. Surgical dislocation of the hip provides a safe means to treat FAI. This approach preserves the blood supply to the femoral head while providing 360° access to perform osteochondroplasty and labral reattachment as needed. By restoring the congruency between the femoral head and the acetabulum, this approach may allow the patient to return to high demand activities without experiencing the symptoms and progressive joint destruction seen with FAI.

Acetabular retroversion has been proposed to contribute to the development of osteoarthritis of the hip. For the diagnosis of this condition, conventional AP pelvic radiographs may represent a reliable, easily available diagnostic modality as they can be obtained with a reproducible technique allowing the anterior and posterior acetabular rims to be visible for assessment. This study was designed to: (i) determine cranial, central, and caudal anatomic acetabular version (AV) from cadaveric specimens; (ii) establish the validity and reliability of the radiographic measurements of central acetabular anteversion; and (iii) determine the validity and reliability of the radiographic "cross-over-sign" to detect acetabular retroversion. Using 43 desiccated pelvises (86 acetabuli) the anatomic AVs were measured at three different transverse planes (cranially, centrally, and caudally). From these pelvises, standardized AP pelvic radiographs were obtained. To directly measure central AV, a modified radiographic method is introduced for the use of AP pelvic radiographs. The validity and reliability of this radiographic method and of the radiographic cross-over-sign to detect cranial acetabular retroversion were determined. The mean central and caudal anatomic AVs were approximately 20 degrees , and the mean cranial AV was 8 degrees . Cranial retroversion (AV < 0 degrees ) was present in 19 of 86 hips (22%). A linear correlation was found between the central and cranial AV. Below 10 degrees of central AV, all acetabuli were cranially retroverted. Between 10 degrees and 20 degrees , 30% of the acetabuli were cranially retroverted, and above 20 degrees , only 1 of 45 acetabuli was cranially retroverted. The radiographic measurement of the central AV (20.3 +/- 6.5 degrees ) correlated strongly with the anatomic AV (20.1 +/- 6.4 degrees ). The sensitivity of the cross-over-sign to detect a cranial acetabular anteversion of less than 4 degrees was 96%, its specificity 95%, and the positive predictive and negative predictive values 90% and 98%, respectively. Both the modified radiographic anteversion measurements and the cross-over-sign demonstrated substantial inter- and intraobserver reliability. Retroversion is almost exclusively a problem of the cranial acetabulum. The cranial AV is on average 12 degrees lower than the central AV, with the latter directly measurable from AP pelvic radiographs. A central AV of less than 10 degrees was associated with cranial retroversion. The presence of a positive cross-over-sign is a highly reliable indicator of cranial AV of

The periacetabular osteotomy is a strategy for the treatment of residual hip dysplasia in young adults with the aim of preventing secondary coxarthrosis. This polygonal, juxta-articular osteotomy respects the vascular blood supply to the acetabular fragment and thus facilitates an extensive acetabular reorientation with improvement of the insufficient coverage of the femoral head, including medial displacement of the fragment. All osteotomies are performed by one approach, the modified Smith-Petersen, which allows an anterior capsulotomy. Inspection of the joint not only provides information on acetabular rim pathologies, but also facilitates the control of impingement-free range of motion after the correction. The posterior column remains partially intact, allowing minimal internal fixation of the acetabular fragment and early mobilization similar to that after an intertrochanteric osteotomy. The dimensions of the true pelvis are unchanged, providing the capacity to have an unimpeded delivery in women. This paper describes the preoperative evaluation, current indications, surgical technique, postoperative care, and the results of this osteotomy.

Femoral head fractures are rare injuries; incongruency and instability are indications for surgical intervention. Anterior, posterior, and transtrochanteric surgical approaches have been proposed, but the exposure is limited with classical approaches. Surgical hip dislocation allows for a 360° view of the head and may facilitate a reduction in selected head fractures, but to our knowledge, few studies have reported on the results with this technique. We therefore report on the (1) quality of fracture reduction; (2) modified Harris hip score at a minimum of 2 years (mean, 6 years, range, 26-122 months); and (3) frequency of complications, including avascular necrosis (AVN), arthritis development, and heterotopic ossification, in a case series of patients with femoral head fractures treated with this approach.The procedure involves digastric trochanteric flip osteotomy and safe dislocation of the femoral head, preserving its vessels. Using this technique we are able to reduce all displaced femoral head fractures under direct view. Definitive fixation is performed through this approach with 2.7-mm nonabsorbable screws. The same technique may be used also for Pipkin IV fractures to fix transverse, T-type, posterior wall, or posterior column acetabular fracture.Between 2004 and 2011, we used this approach to manage all displaced femoral head fractures in patients younger than 55 years old. A total of 17 patients were thus treated; of those three were lost to followup before 2 years, and one was excluded from study because of severe preoperative neurological impairment, leaving 13 for analysis here. Patient demographic, injury, and surgical variables as well as complications were recorded and retrospectively evaluated. Radiographic outcome was scored according to Matta's criteria on postoperative radiographs. Outcomes were evaluated with the modified Harris hip score. Minimum followup was 24 months (mean, 77 months; SD, 32.8 months).Fracture reduction was anatomic in eight hips and imperfect in five. Mean clinical score was 82 points (SD, 7.7). One patient developed symptomatic femoral head AVN and underwent total hip arthroplasty 4 years after the index procedure; no other patient underwent arthroplasty. Besides this patient, signs of arthritis (Grade I according to Tönnis classification) were found in one patient and heterotopic ossification was recorded in two patients, but neither was symptomatic.Our experience with surgical dislocation shows clinical results comparable to previously reported outcomes in femoral head fractures treated with common approaches; we also present a similar rate of AVN and a lower rate of posttraumatic arthritis, but a higher risk of heterotopic ossification. Further case-control studies are necessary to confirm these statements.Level IV, therapeutic study.

Early radiographic detection of femoroacetabular impingement might prevent initiation and progression of osteoarthritis. The structural abnormality in femoral-induced femoroacetabular impingement (cam type) is frequently asphericity at the anterosuperior head/neck contour. To determine which of six radiographic projections (anteroposterior, Dunn, Dunn/45 degrees flexion, cross-table/15 degrees internal rotation, cross-table/neutral rotation, and cross-table/15 degrees external rotation) best identifies femoral head/neck asphericity, we studied 21 desiccated femurs; 11 with an aspherical femoral head/neck contour and 10 with a spherical femoral head/neck contour. To radiographically quantify femoral head asphericity, we measured the angle where the femoral head/neck leaves sphericity (angle alpha). The aspherical femoral head/neck contours had a greater maximum angle alpha (70 degrees ) compared with the spherical head/neck contours (50 degrees ). The angle alpha varied depending on the radiographic projection: it was greatest in the Dunn view with 45 degrees hip flexion (71 degrees +/- 10 degrees ) and least in the cross-table view in 15 degrees external rotation (51 degrees +/- 7 degrees ). Diagnosis of a pathologic femoral head/neck contour depends on the radiologic projection. The Dunn view in 45 degrees or 90 degrees flexion or a cross-table projection in internal rotation best show femoral head/neck asphericity, whereas anteroposterior or externally rotated cross-table views are likely to miss asphericity. Level of Evidence: Prognostic study, level II-1 (retrospective study).

In this article, we describe our examination protocol and findings using magnetic resonance arthrography (MRA) in the clinical setting of femoroacetabular impingement. All our patients were examined on a 1.5-T Magnetom Vision from Siemens (Erlangen, Germany). Our protocol is designed for patients with femoroacetabular impingement (FAI) but also turned out to be useful for imaging developmental dysplasia of the hip (DDH). In this protocol, axial FLASH and T1W, sagittal and coronal-oblique PDW, and radial double oblique PDW were acquired. The following changes were observed in impingement patients: On the axial thin-slice FLASH-sequence, ante- or retroversion of the acetabulum and presence or absence of acetabular rim cysts was noted. On the axial T1W-sequence, the shape of the anterior femoral head/neck, the presence or absence of impingement cysts, the thickness of the joint capsule, presence or absence of periarticular pathology, and bony appositions of the rim, especially at the postero-inferior lip were found. On the sagittal and coronal-oblique PDW-sequences, the condition of the acetabular and femoral cartilage regarding focal abrasion or cartilage tears, the presence and shape of labral tears and labral changes like mucoid dysplasia, and bony apposition to the anterosuperior and posterosuperior border or intralabral cysts were shown. MRA also allowed us to visualize anterior and/or lateral translation of the femoral head, indicating substantial cartilage deficiency in the area of migration. On the radial PDW-sequence, the site and extent of labral tears and focal cartilage lesions was found. In conclusion, MRA is excellent in the examination of hip disease and our protocol gives additional significant information about the condition of the joint when FAI is present. It allowed us to interpret standard radiographs more precisely and more correctly.

Osteoarthritis of the hip is one of the major causes of pain and disability in the developed world. Resulting therapeutic interventions and socioeconomic expenditures pose a considerable burden on health and social services. Based on experimental and clinical studies, including in situ inspection in consecutive adolescents and young adults undergoing surgical dislocations of the hip, we propose femoroacetabular impingement to cause early osteoarthritis in the nondysplastic hip; morphologic deviations of the acetabulum (regional or global overcoverage) and/or proximal femur with a decreased anterior head-neck offset may lead to repetitive trauma of the peripheral articular cartilage during flexion and internal rotation, particularly in individuals taking regular exercises. Frequently, this becomes symptomatic in the second and third decade of life in patients with an increased sportive activity. Based on predominance of the acetabular or femoral pathology, 2 different types of FAI, the pincer and the cam, are differentiated. Apart from these morphological alterations, a supraphysiological mobility and overuse can contribute to the FAI. The impingement concept has led to a new type of mainly intracapsular hip surgery aimed at improving clearance of the hip to avoid pathological contact.

To retrospectively evaluate if there is an association between juxta-articular fibrocystic changes at the anterosuperior femoral neck and femoroacetabular impingement (FAI).The institutional review board approved this study and did not require informed patient consent. An orthopedic surgeon and a radiologist in consensus retrospectively reviewed the anteroposterior (AP) pelvic radiographs of 117 hips with FAI and compared these images with the AP radiographs of a control group of 132 hips with developmental dysplasia (DD) to determine the prevalence of juxta-articular fibrocystic changes at the anterosuperior femoral neck. Criteria for juxta-articular fibrocystic changes at the anterosuperior femoral neck were location close to the physis and a diameter (of the fibrocystic change) of greater than 3 mm. The sensitivity and specificity of AP pelvic radiography in the detection of these fibrocystic changes were calculated by using an additional 61 hips with FAI and on the basis of findings at magnetic resonance (MR) arthrography, which was routinely performed for assessment of FAI. In 24 patients who underwent joint-preserving surgery for FAI, the fibrocystic changes were localized intraoperatively and the spatial relation of the region of these changes to the area of FAI was identified. Joint-preserving surgery consisted of anterior surgical dislocation of the hip with osteochondroplasty of the proximal femur and/or the acetabular rim to improve the impingement-free range of hip motion. For statistical comparisons, nonparametric tests were performed.Fibrocystic changes were identified on the AP radiographs of 39 (33%) of the 117 FAI-affected hips and on none of the radiographs of the 132 DD-affected hips. According to MR arthrogram findings, the sensitivity, specificity, and positive and negative predictive values of AP pelvic radiography were 64%, 93%, 91%, and 71%, respectively. The mean diameter of the juxta-articular fibrocystic changes was 5 mm (range, 3-15 mm); smaller lesions were more prevalent. Dynamic MR imaging with the hip flexed and intraoperative observations revealed a close spatial relationship between the region of the fibrocystic changes at the anterosuperior femoral neck and the acetabular rim.The high prevalence of juxta-articular fibrocystic changes at the anterosuperior femoral neck and their spatial relation to the impingement site suggest an association and possible causal relationship between these alterations and FAI.

The outcome of 33 total hip arthroplasties using an acetabular reinforcement ring with hook for osteoarthritis associated with developmental dysplasia of the hip was reevaluated after a minimal follow-up of 10 years (average, 10.8 years). Most cases comprised Crowe type II (22 hips) and type III (7 hips) dysplasia. The mean D'Aubigne score increased from 7 to 15 points. Three revisions (9%) were performed for aseptic loosening, 2 of them had a structural autograft. None of the unrevised 30 acetabular reconstructions showed definite radiographic signs of loosening. These results compare favorably with the literature and the acetabular reinforcement ring with hook presents a versatile tool for acetabular bone stock deficiencies.

Objectives: Description of an anatomic condition where a femoroacetabular impingement was identified as the cause for the development of nonunion of the femoral neck. Design: Retrospective analysis. Setting: University hospital. Patients: Three patients, aged 27 to 74 years, in whom, after exclusion of other known factors, a femoroacetabular impingement was identified as the cause for the nonunion of a femoral neck fracture. Intervention: Surgical correction of the femoroacetabular impingement. Main Outcome Measurement: Intraoperative verification of femoroacetabular impingement. Healing of the femoral neck non-union. Results: In all 3 patients, femoroacetabular impingement was confirmed at surgery. After elimination of the cause for impingement, all nonunions went on to uneventful healing. Conclusions: A femoroacetabular impingement mechanism is proposed as a cause for nonunion of femoral neck fractures. Predisposing factors such as bulging at the fracture site or decreased femoral-neck offset should be addressed at the time of initial fracture treatment.