HIP CONDITIONS
FAI
Overview
Femoroacetabular impingement (FAI) refers to abnormal contact between the femoral head and the acetabulum, which can result in labral injury, cartilage damage, and gradually worsening hip pain.
Diagnosis is primarily radiographic, with imaging showing either an aspherical femoral head-neck junction (cam type), excessive anterosuperior acetabular coverage (pincer type), or a combination of both.
Management may be conservative or surgical, depending on factors such as duration of symptoms, patient age, activity level, and the presence of associated joint damage (e.g., labral tears or secondary osteoarthritis).
Clinical presentation
Femoroacetabular impingement (FAI) is commonly seen in active young and middle-aged individuals, with cam-type morphology more frequent in young men and pincer-type in middle-aged women. It results from abnormal contact between the proximal femur and acetabulum during hip motion—particularly flexion—leading to progressive damage within the joint.
Clinically, patients present with activity-related hip or groin pain that worsens with flexion, internal rotation, and adduction, often accompanied by stiffness, difficulty sitting, and sometimes pain radiating to the buttock, back, or thigh. Mechanical symptoms such as clicking, popping, catching, or locking may occur, and some individuals develop gluteal or trochanteric pain due to altered gait mechanics. On examination, hip range of motion is typically restricted (flexion <90°, internal rotation <5°), and the FADIR (flexion, adduction, internal rotation) test reproduces pain, although it is sensitive but not specific; an externally rotated limb may also be observed, especially in cases related to prior slipped capital femoral epiphysis (SCFE).
From a pathophysiological standpoint, FAI arises when the proximal femur abuts the acetabulum during motion. In cam impingement, a femoral-sided abnormality—commonly seen in young athletic males—results from an aspherical femoral head or decreased head–neck offset (e.g., broad anterolateral femoral neck, retroversion), causing shear forces at the chondrolabral junction that lead to cartilage delamination and labral separation. In pincer impingement, an acetabular-sided abnormality—more typical in active middle-aged women—occurs due to excessive acetabular coverage (e.g., acetabular retroversion, coxa profunda, protrusio), leading to repetitive impaction of the femoral neck against the labrum, resulting in labral degeneration and intrasubstance tearing, as well as a “contrecoup” cartilage injury in the posteroinferior acetabulum.
Many patients have a combined cam and pincer morphology (up to 80%), producing mixed patterns of impingement, and deformities such as SCFE can further contribute to abnormal joint mechanics. Over time, these processes are associated with labral degeneration and tears, cartilage injury including flap formation, and eventual development of secondary hip osteoarthritis.
Imaging
Initial imaging evaluation should include plain pelvic radiographs, along with additional femoral neck views such as Dunn, cross-table lateral, frog-leg lateral, or Meyer lateral to better assess the femoral head–neck junction. Cross-sectional imaging (CT or MRI) is often recommended for more detailed characterization, identification of labral and chondral injuries, and preoperative planning.
On AP pelvis radiographs, proper positioning (neutral tilt and rotation) is essential, as malposition can lead to misleading findings. These images are evaluated for signs of cam and pincer morphology, including measurements like the lateral center-edge angle and acetabular index (to assess overcoverage), as well as features such as coxa profunda or protrusio (ilioischial line), crossover and ischial spine signs (acetabular retroversion), posterior wall sign, and pistol grip deformity (cam lesion). Additional lateral views help assess parameters like the anterior center-edge angle and femoral head–neck offset.
CT imaging provides a more precise evaluation of bony morphology in multiple planes, including radial reconstructions along the femoral neck, and is particularly useful for surgical planning with 3D reconstructions. Typical findings include an anterosuperior bony prominence at the femoral head–neck junction (cam lesion), sometimes with associated cysts or herniation pits, while features such as increased acetabular depth or retroversion suggest pincer morphology. Quantitative measures include an increased alpha angle (>55–60°) and reduced femoral head–neck offset (<6–7 mm), as well as abnormal acetabular version.
MRI similarly allows assessment of both cam and pincer morphology, often using 3D sequences for detailed multiplanar evaluation. In addition, it is particularly valuable for detecting associated soft tissue pathology such as labral tears, chondrolabral separation, cartilage damage, and paralabral cysts.
MR or CT arthrography further improves diagnostic accuracy, especially for labral and cartilage lesions. Direct MR arthrography enhances visualization of labral tears and chondral defects, while CT arthrography is considered highly accurate for detecting labral pathology.
Treatment
Non-operative treatment
Nonoperative management consists of activity modification, physical therapy, and NSAID use. It is indicated in patients with minimal symptoms and no mechanical complaints.
Treatment typically involves an initial period of rest or reduced activity, followed by a structured physical therapy program aimed at correcting kinetic chain abnormalities, along with NSAIDs for symptom relief.
Operative treatment
Operative management is considered for patients with persistent symptoms or structural abnormalities and includes several surgical options based on the underlying pathology.
Arthroscopic osteoplasty is indicated in symptomatic patients with mechanical symptoms who have failed conservative treatment and do not have significant arthritis. Outcomes are comparable to open surgery, with the advantage of faster recovery; however, results are less favorable in patients with early osteoarthritis (Tönnis grade ≥1) or subchondral edema on MRI.
Arthroscopic labral repair or reconstruction is performed for symptomatic labral tears that do not respond to nonoperative management, often combined with osteoplasty. Viable labral tissue is repaired or refixated, while nonviable tissue requires reconstruction, both of which have shown better pain relief and functional outcomes compared to debridement alone.
Open surgical hip dislocation with osteoplasty was previously the gold standard and is still indicated in select cases with preserved cartilage, correctable deformity, and more complex structural abnormalities such as residual deformities from SCFE or Perthes disease.
Periacetabular osteotomy is used in patients with significant acetabular structural deformities, particularly retroversion.
Hip arthroplasty is reserved for advanced, end-stage degenerative disease, although the choice between hip resurfacing and total hip replacement remains debated.
Differential Diagnosis
osteoarthritis of the hip
osteonecrosis of the hip
Ischiofemoral impingment
adductor strains and athletic pubalgia
lumbar radiculopathy
iliopsoas pathology
transient osteoporosis of the hip
subchondral insufficiency fractures
HIP LABRAL INJURIES
Overview
A hip labral tear is a disruption of the acetabular labrum, often traumatic in nature, and is most commonly associated with conditions such as acetabular dysplasia. It may present with symptoms like internal snapping of the hip or mechanical locking during movement.
Diagnosis typically requires advanced imaging, most accurately achieved with an MR arthrogram of the affected hip joint.
Initial management is conservative, including NSAIDs, rest, and physical therapy. If symptoms worsen or persist despite nonoperative treatment, arthroscopic intervention—either labral debridement or repair—may be indicated.
Clinical presentation
Hip labral tears may be asymptomatic, but when symptomatic they commonly present with mechanical hip pain, snapping, or vague groin discomfort, sometimes accompanied by a sensation of locking or giving way. Symptoms are often exacerbated by weight-bearing activities, hip flexion, and internal rotation, and may include audible clicking or signs of microinstability.
On physical examination, provocative maneuvers can reproduce pain: anterior labral tears are suggested when pain occurs as the hip moves from flexion, abduction, and external rotation into extension, adduction, and internal rotation, while posterior tears are indicated by pain with the reverse motion. There is often a mismatch between clinical symptoms and imaging findings, which can delay diagnosis, and chronic untreated tears may contribute to early development of osteoarthritis.
Imaging
Plain radiographs and CT scans are usually normal in cases of labral tears, although they may reveal underlying structural abnormalities or signs of osteoarthritis in more advanced stages. On ultrasound, labral tears can appear as abnormal labral shape, hypoechoic clefts, or detachment from the acetabular rim, and paralabral cysts may also be identified.
MRI can evaluate labral integrity primarily when joint effusion is present, allowing visualization of fluid extending into the labrum or chondrolabral junction; additional findings may include labral displacement, cartilage injury, paralabral cysts, or capsular stripping. Signal changes within the labrum on T1 or proton density sequences are not necessarily pathologic, while increased T2 signal may indicate mucoid or cystic degeneration.
Direct MR arthrography is the most accurate imaging modality, significantly outperforming standard MRI, and is less invasive than arthroscopy. It involves injection of a diluted gadolinium contrast agent into the joint to distend it, improving visualization on T1 fat-suppressed sequences and helping distinguish true labral tears from intrasubstance changes.
Treatment
Non-operative treatment
Nonoperative management includes rest, NSAIDs, physical therapy, and corticosteroid injections. It is the first-line treatment for all patients with labral tears, although there is limited data regarding long-term outcomes of conservative management.
Operative treatment
Arthroscopic labral debridement is indicated for patients with persistent symptoms despite conservative treatment, particularly when the tear cannot be repaired. The procedure involves excising unstable portions of the labrum and any associated synovitis, while also addressing underlying conditions such as femoroacetabular impingement (FAI); postoperatively, patients follow limited weight-bearing for about 4 weeks with restricted hip flexion and abduction for 4–6 weeks, and approximately 70–85% achieve short-term symptom relief, though long-term outcomes remain unclear.
Arthroscopic labral repair is considered in patients who fail nonoperative management and have full-thickness tears at the labral–chondral junction, although definitive outcome data is still limited.
Labral reconstruction is reserved for cases with irreparable labral damage after failed conservative care, with studies showing similar patient-reported outcomes between autograft and allograft techniques.
Differential Diagnosis
When evaluating small clefts on arthrography, a key consideration is distinguishing true labral tears from labral sulci, which are a normal developmental variant. Labral sulci typically have smooth, well-defined margins, whereas labral tears usually demonstrate irregular, uneven edges.
SNAPPİNG HİP
Overview
Snapping hip syndrome, also known as coxa saltans or dancer’s hip, occurs when an audible snapping sound is produced during hip motion.
3 entities: external snapping hip, internal snapping hip, and intra-articular snapping hip.
External and internal snapping hip are typically diagnosed on clinical grounds using targeted physical examination maneuvers. In contrast, intra-articular snapping hip usually requires advanced imaging for confirmation.
Clinical presentation
Snapping hip syndrome can be divided into three distinct types, each with a different underlying mechanism. The most common is external snapping hip, which occurs when the iliotibial band moves over the greater trochanter.
Internal snapping hip results from the iliopsoas tendon sliding over structures such as the femoral head, a prominent iliopectineal ridge, exostoses of the lesser trochanter, or the iliopsoas bursa. Intra-articular snapping hip is caused by pathology within the joint itself, such as loose bodies, and may be associated with conditions like synovial chondromatosis or labral tears.
Patients typically describe a snapping sensation around the hip that may be either painful or painless and is often reproducible, with symptoms worsening during activity; clicking or locking suggests possible intra-articular pathology. On examination, external snapping hip is usually visible and can be palpated over the greater trochanter during active hip flexion, often stopping with applied pressure, and may be associated with tensor fascia lata tightness on Ober’s test.
In contrast, internal snapping hip is not usually visible but may be audible and can be reproduced by passively moving the hip from a flexed, externally rotated position to an extended, internally rotated position.
Imaging
Radiographic evaluation typically includes AP views of the pelvis or hip, which are usually normal but can help exclude conditions such as synovial chondromatosis.
Ultrasound is a useful dynamic modality that can visualize the snapping structure in both internal and external types and may also guide diagnostic injections into the trochanteric bursa, iliopsoas sheath, or intra-articular space.
MRI is helpful for assessing intra-articular pathology and is often performed as an arthrogram, with possible findings including inflammation of the bursa.
Treatment
Non-operative treatment
Nonoperative management is usually sufficient, as both internal and external snapping hip are often painless and may not require treatment. When symptoms are present, activity modification is recommended, particularly in cases with a recent onset (less than 6 months) of painful snapping.
For patients with persistent and symptomatic snapping that interferes with daily activities, treatment may include physical therapy and corticosteroid injections.
Operative treatment
Surgical management depends on the underlying type of snapping hip and is considered when conservative treatment fails. For external snapping hip, excision of the greater trochanteric bursa combined with Z-plasty of the iliotibial band is indicated in patients with persistent pain or snapping following total hip replacement.
In cases of internal snapping hip, release of the iliopsoas tendon is performed when symptoms remain refractory to nonoperative measures. For intra-articular snapping hip, hip arthroscopy is indicated when imaging confirms pathology such as loose bodies or a labral tear, allowing for removal or repair as needed.
TROCHANTERIC BURSITIS
Overview
Trochanteric bursitis is a frequent cause of lateral hip pain, typically resulting from repetitive friction as the iliotibial band moves over the trochanteric bursa.
Diagnosis is mainly clinical, based on focal tenderness over the greater trochanter.
Management is conservative and includes NSAIDs, stretching exercises, physical therapy, and in some cases corticosteroid injections.
Clinical presentation
Patients commonly report lateral hip pain that may extend down toward the knee, with tenderness on palpation and worsening discomfort during aggravating activities. Pain can also be reproduced on examination, particularly with passive external rotation.
However, these findings are nonspecific and may also indicate other conditions in the area, such as gluteal tendinopathy or thickening of the iliotibial band.
Imaging
Ultrasound
The greater trochanteric bursa is typically distended by anechoic or hypoechoic fluid 4.
MRI: will show increased signal in bursa due to inflammation on T2 sequence
T1: corresponding region of low signal
T2: bursa is enlarged and of high signal
T1 C+ (Gd): peripheral rim enhancement
Treatment
Non-operative treatment
NSAIDS, stretching, PT including modalities, corticosteroid injections are the first line treatment.
Operative treatment
Can be done only after conservative measures fail with open vs arthroscopic trochanteric bursectomy
Differential Diagnosis
Distal gluteus medius or minimus tear (partial or full thickness) or tendinosis
iliotibial band thickening
soft tissue tumor
post-traumatic fluid collection (i.e. hematoma, seroma, lymphocele)
Morel-Lavallée lesion
References
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Griffin DR, Dickenson EJ, O'Donnell J, Agricola R, Awan T, Beck M, Clohisy JC, Dijkstra HP, Falvey E, Gimpel M, Hinman RS, Hölmich P, Kassarjian A, Martin HD, Martin R, Mather RC, Philippon MJ, Reiman MP, Takla A, Thorborg K, Walker S, Weir A, Bennell KL. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement. Br J Sports Med. 2016 Oct;50(19):1169-76. doi: 10.1136/bjsports-2016-096743. PMID: 27629403.
Trigg SD, Schroeder JD, Hulsopple C. Femoroacetabular Impingement Syndrome. Curr Sports Med Rep. 2020 Sep;19(9):360-366. doi: 10.1249/JSR.0000000000000748. PMID: 32925375.
Griffin DR, Dickenson EJ, Wall PDH, Achana F, Donovan JL, Griffin J, Hobson R, Hutchinson CE, Jepson M, Parsons NR, Petrou S, Realpe A, Smith J, Foster NE; FASHIoN Study Group. Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): a multicentre randomised controlled trial. Lancet. 2018 Jun 2;391(10136):2225-2235. doi: 10.1016/S0140-6736(18)31202-9. Epub 2018 Jun 1. PMID: 29893223;