Hip impingement: beyond femoroacetabular

Groin Pain Syndrome Italian Consensus Conference update 2023

Groin pain syndrome (GPS) is a controversial topic in Sports Medicine. The GPS Italian Consensus Conference on terminology, clinical evaluation and imaging assessment of groin pain in athletes was organized by the Italian Society of Arthroscopy in Milan, on 5 February 2016. In this Consensus Conference (CC) GPS etiology was divided into 11 different categories for a total of 63 pathologies. The GPS Italian Consensus Conference update 2023 is an update of the 2016 CC. The CC was based on a sequential, two-round online Delphi survey, followed by a final CC in the presence of all panelists. The panel was composed of 55 experts from different scientific and clinical backgrounds. Each expert discussed 6 different documents, one of which regarded the clinical and imaging definition of sports hernias, and the other 5 dealt with 5 new clinical situations thought to result in GPS. The panelists came to an agreement on the definition of a sports hernia. Furthermore, an agreement was reached, recognizing 4 of the 5 possible proposed pathologies as causes to GPS. On the contrary, the sixth pathology discussed did not find consensus given the insufficient evidence in the available scientific literature. The final document includes a new clinical and imaging definition of sports hernia. Furthermore, the etiology of GPS was updated compared to the previous CC of 2016. The new taxonomic classification includes 12 categories (versus 11 in the previous CC) and 67 pathologies (versus 63 in the previous CC).

One case of wrist cyst rupture with nerve and blood vessel compression

Introduction and importance

Tendon sheath cysts are mostly located around the joint capsule and tendon sheath, which often occur in the wrist, ankle, and wrist back (O'Valle et al., 2014; Nguyen et al., 2004 [1, 2]). The palmar side of the wrist is relatively rare, which is often associated with the wrist. Ultrasound and MRI can detect and diagnose early.

Case presentation

In this case report, we discussed an elderly woman with palmar carpal tendon sheath cyst and ruptured. She communicated with the outside world through the skin sinus, and at the same time pressed the radial artery and the median nerve to produce obvious clinical symptoms.

Clinical discussion

Because of its deep position and close relationship with the surrounding important nerves and vessels, the operation was relatively difficult. In particular, in this case, tendon sheath cyst ruptured to form sinus, so there were some difficulties.

Conclusion

Pathological diagnosis was tendon sheath cyst. The analysis of the relationship between the tumor and the surrounding tissue by preoperative MRI and other imaging examinations has important guiding significance for surgery.

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This case underwent surgical treatment due to cyst rupture with nerve and vascular compression symptoms.

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Analysis of the relationship between tumor and surrounding tissue by preoperative MRI and other imaging examinations.

Morscher's femoral neck lengthening osteotomy through surgical hip dislocation approach for preservation of Perthes and Perthes-like deformities

Background

Typical sequelae of Perthes disease and Perthes-like deformities comprise a short femoral neck, aspherical femoral head, and greater trochanteric overgrowth. Morscher's osteotomy aims at restoring the normal extra-articular anatomy, but incapable of restoring a normal head-neck contour with residual impingement. Femoral neck lengthening osteotomy combined with osteochondroplasty through surgical hip dislocation approach was not previously described in the literature. We hypothesized that this technique is capable of near-normal restoration of the proximal femoral anatomy, increasing limb length, restoring abductor power, and simultaneous management of intra-articular chondro-labral disease.

Methods

A prospective series of 21 consecutive patients with sequelae of Perthes disease and Perthes-like deformity (Stulberg II and III) were treated by Morscher's osteotomy through surgical hip dislocation approach. The mean age was 14.9 years (9-30 years) and the mean follow-up was 4.5 years (2-8 years).

Results

The mean Harris hip score improved significantly from 66.5 to 89.5 points (p < 0.001), and the mean limb length discrepancy improved from 2.5 to 0.6 cm (p < 0.001). The mean alpha angle improved from 81.8° to 49.5°, the mean neck-shaft angle increased from 117.8° to 129.8°, and the articulo-trochanteric distance has improved from -6.7 to 20.8 mm. Six out of 21 patients required staged periacetabular osteotomy for residual acetabular dysplasia. No cases of chondrolysis or osteonecrosis were identified.

Conclusion

Femoral neck lengthening osteotomy through surgical hip dislocation appraoch has proven to be safe and effective for preservation of symptomatic hips with Perthes and Perthes-like deformities and mild to moderate femoral head deformities (Stulberg II and III). A staged periacetabular osteotomy may be required in those patients with significant acetabular dysplasia.

Level of evidence

Level IV.

Combined Imhauser osteotomy and osteochondroplasty in slipped capital femoral epiphysis through surgical hip dislocation approach

PURPOSE

Treatment of moderate to severe stable slipped capital femoral epiphysis (SCFE) remains a challenging problem. Open reduction by modified Dunn procedure carries a considerable risk of osteonecrosis (ON). Imhauser osteotomy is capable of realigning the deformity without the risk of ON, but the remaining metaphyseal bump is implicated with significant chondro-labral lesions and accelerated osteoarthritis. We conducted this study to evaluate the efficacy and safety of Imhauser osteotomy combined with osteochondroplasty (OCP) through the surgical hip dislocation (SHD) approach.

METHODS

A prospective series of 23 patients with moderate-severe stable SCFE underwent Imhauser osteotomy and OCP through SHD. The mean age was 14.4 years (13 to 20) and the mean follow-up period was 45 months (24 to 66). The outcome measures included clinical and radiological parameters and Harris hip score (HHS) was used as a functional score.

RESULTS

The mean HHS improved significantly from 65.39 to 93.3. The limb length discrepancy improved by a mean of 1.72 cm. The mean flexion and abduction arcs showed a significant improvement (mean increase of 37.5° and 18.5°, respectively). The mean internal rotation demonstrated the most significant improvement (mean increase of 38.5°). All the radiographic parameters improved significantly; including anterior and lateral slip angles (mean improvement 37.52° and 44.37°, respectively). The mean alpha angle decreased by 39.19°. The articulo-trochanteric distance significantly increased to a mean of 23.26 mm. No cases of ON or chondrolysis were identified.

CONCLUSION

Combined Imhauser osteotomy and OCP through the surgical dislocation approach provide a comprehensive and safe management of moderate to severe stable SCFE.

LEVEL OF EVIDENCE

IV.

Incidence of a stem sitting proud of a proximally coated cementless tapered wedge stem

BACKGROUND/OBJECTIVE

A stem sitting proud (SP) or that above the final rasp position remains in some patients who undergo hip replacement using proximally coated tapered wedge stems. Surgeons may face challenges providing the best fit because of unpredictable SP of proximally coated tapered wedge stems. Zimmer Inc. introduced a new rasp to solve this issue but the clinical results of this rasp have not yet been published. Therefore, our aim was to address the following: (1) What is the stem SP incidence using a proximally coated cementless tapered wedge stem? (2) Does the new rasp system (0-mm rasp) improve seating height? and (3) What are the risk factors of stem SP?

METHODS

We performed a retrospective study with 338 hips, in which Tri-Lock Bone Preservation Stem (BPS) was used in 181 hips and M/L Taper stem was used in 157 hips (82 hips before and 75 hips after 0-mm rasp use). A positive stem SP was defined as a stem proud height of >2 mm. We analysed and compared SP incidence in two stems and M/L Taper stems before and after the 0-mm rasp use.

RESULTS

An incidence of stem SP was 13% in the Tri-Lock BPS and 15% in the M/L Taper stem before the 0-mm rasp use. Stem SP incidence in the M/L Taper stem substantially decreased after the 0-mm rasp use (4%). The significant risk factor for stem SP was use of the high offset option in Tri-Lock BPS.

CONCLUSION

The proximally coated tapered wedge stems present potential problems related to stem SP. The new rasp of the M/L Taper stem showed significant improvement in initial seating height.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

This study was conducted to understand "stem sitting proud" in proximally coated tapered wedge stem as one of the most popular designs nowadays in adult hip joint arthroplasty field. In this study, we aimed to address the incidence of stem proud, investigated the risk factor and introduced the effect of new rasp system which improve stem seating height.

Current trends in sport and exercise hip conditions: Intra-articular and extra-articular hip pain, with detailed focus on femoroacetabular impingement (FAI) syndrome

Musculoskeletal conditions, such as hip pain are leading causes of pain and disability. Hip pain is the second most common cause of lower limb musculoskeletal pain, and is commonly seen in active individuals. Hip and groin pain may have intra-articular and extra-articular causes. Femoroacetabular impingement (FAI) syndrome and the associated pathologies are common intra-articular causes of hip and groin pain in active individuals. There are also a number of extra-articular causes of pain, which include musculotendinous conditions, extra-articular impingements and the clinical entities of groin pain described in the Doha agreement. This chapter will describe these, with a detailed focus on FAI syndrome. Specifically, it addresses: 1. What is and what causes FAI syndrome; 2. How do I diagnose FAI syndrome; and 3. What is the evidence-based approach to managing FAI syndrome?

Hip Joint Torsional Loading Before and After Cam Femoroacetabular Impingement Surgery

BACKGROUND

Surgical management of cam femoroacetabular impingement (FAI) aims to preserve the native hip and restore joint function, although it is unclear how the capsulotomy, cam deformity, and capsular repair influence joint mechanics to balance functional mobility.

PURPOSE

To examine the contributions of the capsule and cam deformity to hip joint mechanics. Using in vitro, cadaveric methods, we examined the individual effects of the surgical capsulotomy, cam resection, and capsular repair on passive range of motion and resistance of applied torque.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve cadaveric hips with cam deformities were skeletonized to the capsule and mounted onto a robotic testing platform. The robot positioned each intact hip in multiple testing positions: (1) extension, (2) neutral 0°, (3) flexion 30°, (4) flexion 90°, (5) flexion-adduction and internal rotation (FADIR), and (6) flexion-abduction and external rotation. Then the robot performed applicable internal and external rotations, recording the neutral path of motion until a 5-N·m of torque was reached in each rotational direction. Each hip then underwent a series of surgical stages (T-capsulotomy, cam resection, capsular repair) and was retested to reach 5 N·m of internal and external torque again after each stage. During the capsulotomy and cam resection stages, the initial intact hip's recorded path of motion was replayed to measure changes in resisted torque.

RESULTS

Regarding changes in motion, external rotation increased substantially after capsulotomies, but internal rotation only further increased at flexion 90° (change +32%, P = .001, d = 0.58) and FADIR (change +33%, P < .001, d = 0.51) after cam resections. Capsular repair provided marginal restraint for internal rotation but restrained the external rotation compared with the capsulotomy stage. Regarding changes in torque, both internal and external torque resistance decreased after capsulotomy. Compared with the capsulotomy stage, cam resection further reduced internal torque resistance during flexion 90° (change -45%, P < .001, d = 0.98) and FADIR (change -37%, P = .003, d = 1.0), where the cam deformity accounted for 21% of the intact hip's torsional resistance in flexion 90° and 27% in FADIR.

CONCLUSION

Although the capsule played a predominant role in joint constraint, the cam deformity provided 21% to 27% of the intact hip's resistance to torsional load in flexion and internal rotation. Resecting the cam deformity would remove this loading on the chondrolabral junction.

CLINICAL RELEVANCE

These findings are the first to quantify the contribution of the cam deformity to resisting hip joint torsional loads and thus quantify the reduced loading on the chondrolabral complex that can be achieved after cam resection.

Altered Walking and Muscle Patterns Reduce Hip Contact Forces in Individuals With Symptomatic Cam Femoroacetabular Impingement

BACKGROUND

Cam-type femoroacetabular impingement (FAI) is a causative factor for hip pain and early hip osteoarthritis. Although cam FAI can alter hip joint biomechanics, it is unclear what role muscle forces play and how they affect the hip joint loading. Purpose/Hypothesis: The purpose was to examine the muscle contributions and hip contact forces in individuals with symptomatic cam FAI during level walking. Patients with symptomatic cam FAI would demonstrate different muscle and hip contact forces during gait.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eighteen patients with symptomatic cam FAI were matched for age and body mass index with 18 control participants. Each participant's walking kinematics and kinetics were recorded throughout a gait cycle (ipsilateral foot-strike to ipsilateral foot-off) by use of a motion capture system and force plates. Muscle and hip contact forces were subsequently computed by use of a musculoskeletal modeling program and static optimization methods.

RESULTS

The FAI group walked slower and with shorter steps, demonstrating reduced joint motions and moments during contralateral foot-strike, compared with the control group. The FAI group showed reduced psoas major (median, 1.1 newtons per bodyweight [N/BW]; interquartile range [IQR], 1.0-1.5 N/BW) and iliacus forces (median, 1.2 N/BW; IQR, 1.0-1.6 N/BW), during contralateral foot-strike, compared with the control group (median, 1.6 N/BW; IQR, 1.3-1.6 N/BW, P = .004; and median, 1.5 N/BW; IQR, 1.3-1.6 N/BW, P = .03, respectively), which resulted in lower hip contact forces in the anterior ( P = .026), superior ( P = .02), and medial directions ( P = .038). The 3 vectors produced a resultant peak force at the anterosuperior aspect of the acetabulum for both groups, with the FAI group demonstrating a substantially lower magnitude.

CONCLUSION

FAI participants altered their walking kinematics and kinetics, especially during contralateral foot-strike, as a protective mechanism, which resulted in reduced psoas major and iliacus muscle force and anterosuperior hip contact force estimations.

CLINICAL RELEVANCE

Limited hip mobility not only is attributed to bone-on-bone impingement, caused by cam morphology, but could be attributed to musculature as well. Not only would the psoas major and iliacus be able to protect the hip joint during flexion-extension, athletic conditioning could further strengthen core muscles for improved hip mobility and pelvic balance.

Current Concepts Review: Evaluation and Management of Posterior Hip Pain

Understanding the etiology of and evolving research on intra- and extra-articular hip complaints requires comprehensive diagnosis and management of the spectrum of posterior hip diseases. Interest in posterior hip disorders has increased in recent years as new studies and theories have emerged regarding the disease process. Although most of the differential diagnoses around the posterior hip have traditionally been considered uncommon, recent reports suggest that these complaints have instead been commonly overlooked. Failure to identify the cause of posterior hip pain in a timely manner can increase pain perception, deteriorate the patient's hope, and consequently affect quality of life. Posterior hip pain could be differentiated as intrapelvic and extrapelvic, and differential diagnosis is made based on a comprehensive history, physical examination, and imaging studies. Plain radiography, CT, MRI, 3T MRI, and imaging-guided injection tests are usually necessary for accurate diagnosis. Surgical intervention, whether endoscopic or open, is required for patients with long-standing symptoms for whom nonsurgical treatment has been unsuccessful and who have experienced temporary relief of their symptoms after injection. Orthopedic surgeons are uniquely trained in understanding the anatomy, biomechanics, clinical evaluation and treatment of all five layers of the hip.

Articular and peri-articular hip lesions in soccer players. The importance of imaging in deciding which lesions will need surgery and which can be treated conservatively?

Soccer is one of the most popular sports worldwide engaging millions of participants each year. During play, injuries occur rather frequently and most of them involve the hip joint and the surrounding structure. In professional athletes, injuries are often complex scenarios and in the case of misdiagnosis, patients' return to play is delayed or it may progress to a more serious injury with consequent damage for their career and for the soccer team. The most frequent articular pathologies are Femoro-acetabular impingement and labral tears. Stress fracture, avulsion, ischiofemoral impingement, subspine impingement, athletic pubalgia, muscle injuries and Morel-Levallèe lesion are the most frequent hip peri-articular pathologies whereas snapping hip may be both intra- or extra-articular pathology. With an increasing number of football players, the radiologist plays a crucial role in the detection and characterization of the extent of the injuries. This article reviews the current imaging concepts frequently seen in injuries around the hips of professional football players focusing in particular on the most suitable therapeutic approaches, whether surgical or conservative.

Can a Brief Training Session Prepare Physician Sonographers of Differing Experience to Measure the Ischiofemoral Space? A Reliability Study

OBJECTIVE

The primary aim of this study was to determine the inter- and intrarater reliability of ultrasound (US) measurements of the ischiofemoral space (IFS) following a brief training session. A secondary aim was to determine if reliability correlated with sonographer experience.

DESIGN

Prospective cohort study.

SETTING

Physical medicine and rehabilitation department within a tertiary care institution.

PARTICIPANTS

Seven male and 3 female individuals were recruited to serve as models. Nine physician sonographers (3 postgraduate year [PGY]-2 residents, 3 PGY-4 residents, 3 physicians) were recruited to serve as sonographers.

METHODS OR INTERVENTIONS

Sonographers received a 15-minute educational session on identifying the IFS with US, followed by 20 minutes of practice. Models were then placed in a prone position and secured to prevent hip movement. All operators measured bilateral IFSs in each model twice with a washout period between measurements. Operators were blinded to all measurements.

MAIN OUTCOME MEASURES

Primary outcomes were inter- and intrarater reliability interclass coefficients (ICCs) of IFS measurements among the groups with different levels of US experience. Secondary outcomes included comparisons of inter- and intrarater reliability ICCs of IFS measurements between groups, and the difference of mean IFS measurements between groups.

RESULTS

Intrarater reliability ICCs were 0.829, 0.680, and 0.596 for physician, PGY-4, and PGY-2 groups, respectively. Interrater reliability ICCs were 0.722, 0.427, and 0.558 for physician, PGY-4, and PGY-2 groups, respectively. No statistically significant differences in reliability were identified between groups. Mean IFS measurements were 31.2, 33.4, and 34.0 mm for physician, PGY-4, and PGY-2 groups, respectively. Physician measurements were significantly smaller than the PGY-4 and PGY-2 measurements (P < .049 and P < .01).

CONCLUSIONS

Following a brief training session, experienced sonographers demonstrated excellent IFS measurement intrarater reliability, whereas PGY-4 and PGY-2 sonographers demonstrated fair intrarater reliability. All sonographers demonstrated fair interrater reliability.

LEVEL OF EVIDENCE

II.

Anatomic Predictors of Sagittal Hip and Pelvic Motions in Patients With a Cam Deformity

BACKGROUND

As there is a high prevalence of patients with cam deformities and no ongoing hip dysfunction, understanding the biomechanical factors predicting the onset of symptoms and degenerative changes is critical. One such variable is how the spinopelvic parameters may influence hip and pelvic sagittal mobility. Hypothesis/Purpose: Pelvic incidence may predict sagittal hip and pelvic motions during walking and squatting. The purpose was to determine which anatomic characteristics were associated with symptoms and how they influenced functional hip and pelvic ranges of motion (ROMs) during walking and squatting.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fifty-seven participants underwent computed tomography and were designated either symptomatic (n = 19, cam deformity with pain), asymptomatic (n = 19, cam deformity with no pain), or control (n = 19, no cam deformity or pain). Multiple femoral (cam deformity, neck angle, torsion), acetabular (version, coverage), and spinopelvic (pelvic tilt, sacral slope, pelvic incidence) parameters were measured from each participant's imaging data, and sagittal hip and pelvic ROMs during walking and squatting were recorded using a motion capture system.

RESULTS

Symptomatic participants had large cam deformities, smaller femoral neck-shaft angles, and larger pelvic incidence angles compared with the asymptomatic and control participants. Discriminant function analyses confirmed that radial 1:30 alpha angle (λ₁ = 0.386), femoral neck-shaft angle (λ₂ = 0.262), and pelvic incidence (λ₃ = 0.213) ( P < .001) were the best anatomic parameters to classify participants with their groups. Entering these 3 parameters into a hierarchical linear regression, significant regressions were achieved for hip ROM only when pelvic incidence was included for walking ( R² = 0.20, P = .01) and squatting ( R² = 0.14, P = .04). A higher pelvic incidence decreased walking hip ROM ( r = -0.402, P = .004). Although symptomatic participants indicated a trend of reduced squatting hip and pelvic ROMs, there were no significant regressions with the anatomic parameters.

CONCLUSION

A cam deformity alone may not indicate early clinical signs or decreased ROM. Not only was pelvic incidence a significant parameter to classify the participants, but it was also an important parameter to predict functional ROM. Symptomatic patients with a higher pelvic incidence may experience limited sagittal hip mobility.

CLINICAL RELEVANCE

Patients with symptomatic femoroacetabular impingement showed a higher pelvic incidence and, combined with a cam deformity and varus neck, can perhaps alter the musculature of their iliopsoas, contributing to a reduced sagittal ROM. With an early and accurate clinical diagnosis, athletes could benefit from a muscle training strategy to protect their hips.

[Surgical therapy of ischiofemoral impingement by lateralizing intertrochanteric osteotomy]

OBJECTIVE

Lateralizing, derotating intertrochanteric varus osteotomy to increase the ischiofemoral space to counter painful impingement of the lesser trochanter and the os ischium with resulting entrapment of quadratus femoris muscle.

INDICATIONS

Symptomatic ischiofemoral impingement (IFI) caused by Coxa valga et antetorta, Coxa valga or Coxa antetorta, or a short femoral neck.

CONTRAINDICATIONS

Anatomic configuration suggestive of IFI in asymptomatic patients. Symptomatic IFI caused by another underlying pathology. Valgus deformity of the knee.

SURGICAL TECHNIQUE

Measurement of femoral antetorsion. Planning of the osteotomy, lateralization, varus angle for correction, rotation and offset correction, leg length change, and osteosynthesis plate. General or spinal anesthesia in supine or lateral position. Skin incision (15 cm) beginning lateral of the greater trochanter tip, distally along the axis of the femur. Preparation onto the femur by L‑shaped dissection of the vastus lateralis from the bone. A Kirschner(K-)wire is then positioned along the anterior femoral neck to designate the femoral neck antetorsion. A triangle set on the lateral femoral cortexis is used to determine the osteotomy angle. In the thus determined angle, a second K‑wire is shot centrally along the femoral neck axis just inferior to its cranial cortex. About 5 mm distal to the second wire, the entry for the blade is prepared using a drill. Using the blade setting instrument, the blade is introduced into the femoral neck, then slightly pulled back. The rotation is then marked on the anterior femoral cortex proximal and distal to the planned osteotomy and the osteotomy is performed. A blade plate without displacement is impacted. The osteotomy is then reduced, the distal fragment pulled laterally onto the plate, and the screws inserted after compression of the osteotomy with a tension device.

POSTOPERATIVE MANAGEMENT

Touch-toe bearing for 6 weeks, then radiological assessment of osteotomy healing before an increase in weight bearing (15 kg/week). Hip flexion limited to 90° for 6 weeks. Elective implant removal after 12-18 months.

RESULTS

Studies of this lateralizing varus osteotomy have not been published. The 25-year results of the conventional derotating intertrochanteric varus osteotomy technique show good functional results and low complication rates, with non-union being the most common. Arthroscopic resection of the lesser trochanter has been reported as a surgical alternative in the treatment of IFI in case reports and small series. Advantages of the osteotomy are the restoration of biomechanics and preservation of iliopsoas tendon insertion.

[Arthroscopic decompression of extra-articular subspinal hip impingement]

OBJECTIVE

Complete arthroscopic decompression of the impinging subspinal soft tissues and resection of the hypertrophic bone formation between the anterior hip capsule and the anterior inferior iliac spine (AIIS) or decompression of a hypertrophic AIIS.

INDICATIONS

Painful anterior hip impingement and decreased hip flexion following a hypertrophic osseous subspinal deformation.

CONTRAINDICATIONS

No clinical symptoms or decreased anterior hip function despite radiological osseous subspinal hip impingement.

SURGICAL TECHNIQUE

Hip arthroscopy in supine position on an extension table. Treatment of possible intraarticular hip pathologies in the central or peripheral compartment. Arthroscopic visualization of the hypertrophic impinging soft tissues below the AIIS and decompression using a shaver or radiofrequency device. Complete arthroscopic resection of the hypertrophic AIIS parts and the osseous subspinal deformation using a high speed burr under fluoroscopic control.

POSTOPERATIVE MANAGEMENT

Early functional rehabilitation with full weight-bearing and unlimited hip motion; 3 weeks ossification prophylaxis and 8 weeks of limitation for jumping and running sports activities.

RESULTS

There are no comparative studies or medium- and long-term study results in the literature for arthroscopic AIIS decompression. However, currently published case series show an improvement of the determined scores.

Extra-articular hip impingement: a review of the literature

Hip and groin pain is a common clinical problem. Multiple causes can generate hip or groin pain, often sharing clinical and demographic characteristics. Diagnostic imaging tests play an important role in the etiological diagnosis. New forms of extra-articular hip impingement have recently been recognized as a cause of hip pain and limited function especially in young active patients. These conditions include ischiofemoral impingement, anterior inferior iliac spine and subspine impingement, iliopsoas impingement and greater trochanteric-pelvic impingement. In general, they are caused by a mechanical conflict with an abnormal or excessive contact between the proximal femur and pelvis and/or soft tissue between them. In this manuscript we review the physiopathology, clinical presentation, the most common radiologic findings and treatment of these forms of extra-articular hip impingement.

How to address ischiofemoral impingement? Treatment algorithm and review of the literature

Ischiofemoral impingement (IFI) is a rare cause of hip pain defined by a narrowing of the space between the lateral aspect of the os ischium and the lesser trochanter of the femur. Several underlying anatomic, functional and iatrogenic pathologies have been identified for symptomatic IFI in native hip joints and after total hip arthroplasty. Clinical symptoms vary but most commonly consist of pain of the lower buttock and groin including the inner thigh, and a snapping or clunking phenomenon is often reported. Symptoms may be provoked by a combined extension, adduction and external rotation during physical examination and during long-stride walking. Radiographs of the pelvis and an axial or false-profile-view of the hip as well as magnetic resonance imaging (MRI)-scans should be obtained to strengthen the diagnosis. On MRI, the quadratus femoris muscle signal and the space confined by the anatomic structures surrounding the muscle, the quadratus femoris space, are to be assessed. Targeted infiltration of the muscle can be helpful both diagnostically and therapeutically. The literature on differential diagnoses and treatment options for IFI is limited; therapeutic suggestions are offered only in case reports and series. With this work, we aim to give a systematic approach to the non-surgical and surgical treatment options for IFI based upon the current literature and the authors' personal experience.

Arthroscopic Iliopsoas Release at the Level of the Lesser Trochanter Following Total Hip Arthroplasty

Iliopsoas impingement is an uncommon cause of pain after total hip arthroplasty. If pain persists after a trial of conservative treatment, surgical intervention can alleviate the patient's symptoms. Multiple advantages exist to release the iliopsoas tendon at the level of the lesser trochanter. The purpose of this Technical Note is to demonstrate a technique for arthroscopic release of the iliopsoas tendon at the lesser trochanter after total hip arthroplasty.

Imaging of impingement syndromes around the hip joint

Impingement syndromes are increasingly recognised as significant causes of hip pain and dysfunction. A broad spectrum of intraarticular and extraarticular conditions has been implicated in their pathophysiology. Physical examination is often inconclusive as clinical findings may be unclear or misleading, often simulating other disorders. With current improvements in imaging techniques and better understanding of hip impingement related pathomechanisms, these entities can be accurately diagnosed. In addition, preoperative imaging has allowed for targeted treatment planning. This article provides an overview of the various types of hip impingement, including femoroacetabular impingement, ischiofemoral impingement, snapping hip syndrome, greater trochanteric-pelvic and subspine impingement. Current literature data regarding their pathogenesis, clinical manifestation and imaging work-up are discussed.

Current concepts in the diagnosis and management of extra-articular hip impingement syndromes

PURPOSE

Extra-articular hip impingement syndromes encompass a group of conditions that have previously been an unrecognised source of pain in the hip and on occasion been associated with intra-articular hip impingement as well. As arthroscopic techniques for the hip continue to evolve, the importance of these conditions has been recognised recently and now form an important part of the differential of an individual presenting with hip pain. The aim of this article, therefore, is to provide the reader with an evidence-based and comprehensive update of these syndromes.

METHODS

By reviewing past literature, the anatomy, pathophysiology, clinical features and the management of the five common extra-articular hip impingement syndromes were described.

RESULTS

The common extra-articular impingement syndromes are: 1) Ischiofemoral impingement: quadratus femoris muscle becomes compressed between the lesser trochanter and the ischial tuberosity. 2) Subspine impingement: mechanical conflict occurs between an enlarged or malorientated anterior inferior iliac spine and the distal anterior femoral neck. 3) Iliopsoas impingement: mechanical conflict occurs between the iliopsoas muscle and the labrum, resulting in distinct anterior labral pathology. 4) Deep gluteal syndrome: pain occurs in the buttock due to the entrapment of the sciatic nerve in the deep gluteal space. 5) Pectineofoveal impingement: pain occurs when the medial synovial fold impinges against overlying soft tissue, primarily the zona orbicularis. Knowledge for these syndromes still remains limited for reasons mostly relating to their low prevalence and their co-existence with typical femoro-acetabular impingement.

CONCLUSIONS

The knowledge of extra-articular hip impingement syndromes is essential and should form a part of the differential diagnoses alongside intra-articular pathology including femoro-acetabular impingement particularly in the younger patient with a non-arthritic hip.

Arthroscopic Decompression of a Type III Subspine Impingement

Extra-articular hip impingement refers to a variety of hip disorders causing pain and limited function in young, non-arthritic patients. Recently, there has been an increased focus on analyzing the degree of anterior inferior iliac spine (AIIS) dysmorphism and its correlation with subspine impingement (SSI), defined as abutment between a prominent distal aspect of the AIIS and the anterior aspect of the femoral head-neck junction. Arthroscopic decompression of the AIIS is recognized as an effective treatment for SSI. However, there may be some inherent risks of performing this procedure arthroscopically that require further investigation.

Medial synovial fold cyst in the hip leading to pectineofoveal impingement

Pectineofoveal impingement is a relatively rare condition, which can cause hip or groin pain along with mechanical symptoms of clicking in the young adult. We present the case of a 13-year-old girl who was referred to us with left hip pain, which had been affecting her for over six months along with mechanical symptoms of clicking. Following appropriate clinical examination and investigations the patient underwent arthroscopic surgery of her hip. At arthroscopy, a cyst was identified on the medial synovial fold, which was abutting against the zona orbicularis leading to pectineofoveal impingement. The cyst was decompressed and the synovial fold excised arthroscopically. Following arthroscopic intervention, the patient did extremely well and remains asymptomatic at the last follow-up (7 months following the procedure). The case highlights the importance of the medial synovial fold pathology as an important cause for pain and mechanical symptoms in the young adult hip.