Hip arthroscopy can be fraught with complications if preoperative planning and indications are taken lightly. The accurate diagnosis of pathology around the hip can be both challenging and crucial to the success of arthroscopic hip procedures. Because abdominal, neurological, urological, extraarticular, and intraarticular pathology can all present with referred pain to the hip, the clinician must carefully correlate the patient’s history, physical examination, and diagnostic findings to correctly identify hip pathology treatable by arthroscopic means. A deliberate and algorithmic approach to the individual patient’s pathology is required to optimize outcomes and minimize complications. Using hip arthroscopy to treat global hip pain without focusing on identifiable patient- specific pathology will inevitably lead to postoperative complications.
When evaluating a patient with a chief complaint of “hip pain,” it is imperative that a detailed history be taken to establish a correct diagnosis of hip pathology because multiple etiologies of pain may concomitantly exist. Remember that not all pathology is amenable to hip arthroscopy. This is especially crucial in those cases where there is discordance between physical examination and radiological findings because an incorrect diagnosis may preclude successful surgical management. Intraarticular hip pain is commonly described as a deep pain located anteriorly in the groin or deep within the buttocks with specific activities. A prolonged history of intraarticular hip pain may indicate advanced degenerative changes not amenable to arthroscopic intervention. A clear history and physical examination consistent with femoroacetabular impingement (FAI) and that correlates with advanced imaging must be ascertained before arthroscopic management of FAI. A failure to establish this diagnosis will likely lead to treatment failure and possible worsening of symptoms. Similarly, correction of a pincer-type lesion in the setting of a calcified or functionally incompetent labrum with symptomatic microinstability or laxity may induce gross instability and persistent disability. A history of childhood dysplasia or acetabular version abnormalities may be better served with a periacetabular osteotomy (PAO) with or without femoroplasty of the proximal femur because arthroscopic anterior rim trim/acetabuloplasty may lead to iatrogenic symptomatic instability. Pain that localizes to the posterior hip or buttocks may be more indicative of lumbar spine pathology, sacroiliac joint pathology, or piriformis-related pathology. Furthermore, in those patients with equivocal examination findings, a previous history of abdominal, urological, or reproductive pathology may help clarify the patient’s etiology of groin pain unrelated to true hip pathology.
Appropriately assessing preoperative patient characteristics may help predict outcomes following hip arthroscopy. Smoking, female sex, a history of psychiatric disorders, higher body mass index (BMI), having worker’s compensation, longer duration of symptoms, and older age have all been associated with worse patient-reported outcomes (PROs) following hip arthroscopy. , This assessment is made strongly apparent by recent studies evaluating patient characteristics, PROs, and intraarticular pathology that found that smoking, preoperative activity level, sex, and a high Veterans RAND 12 Mental Component Score were more predictive of pre- and postoperative pain and function than the intraarticular findings at the time of arthroscopy. , In particular, smoking has been shown to result in lower PROs at 5 years postarthroscopy and to be an independent predictor of inferior clinical outcomes at 2 years following hip arthroscopy. , Studies looking specifically at workers, compensation have shown that PROs are consistently worse in this population preoperatively and postoperatively; however, a clinically important response is still seen after hip arthroscopy. , , Mental health factors, anxiety, and depression have been shown to strongly correlate with the magnitude of preoperative hip pain symptoms and to have a negative impact on PROs following hip arthroscopy. , A patient’s BMI should also be optimized to before undergoing hip arthroscopy, as it has repeatedly been shown to be independently predictive of a worse outcome following hip arthroscopy for FAI treatment. ,
Because of the extent of overlap in provocative testing around the hip, examination of the pelvis, lower extremity, abdomen, and lumbar spine should be conducted on a routine basis and correlated with associated imaging. Gait abnormalities because of abductor weakness is seen in up to 75% of cases and can be confirmed with a concomitant Trendelenburg sign in patients with FAI. , This can be further exacerbated by a decrease in femoral offset that is often seen in this population. Range of motion (ROM) restrictions with hip flexion and internal rotation are most commonly seen with symptomatic FAI because of associated femoral or acetabular abnormalities. Furthermore, side-to-side differences of femoral version should be noted, as this may decrease the effective hip ROM prior without sphericity problems on the femoral head-neck junction or acetabular overcoverage.
It is critical to correlate the physical examination findings and provocative maneuvers with actual patient complaints to ensure that a targeted approach to hip pathology will improve the patient’s presenting symptoms. Anterior impingement testing can be positive in up to 88% of patients experiencing pain because of FAI, elucidating labral pathology or chondral damage by flexing and internally rotating the hip at 90 degrees of flexion at the hip and knee ( Fig. 41.1 ). Loss of internal rotation at 90 degrees with the reproduction of pain symptoms is a hallmark symptom of FAI and has been shown to be inversely related to the severity of a cam lesion. Whereas posterior hip pain with FABER (flexion abduction external rotation) testing may indicate sacroiliac pathology, it has shown a sensitivity of 82% for detecting intraarticular hip pathology when the pain is located anteriorly. , ROM should be noted and compared with the contralateral extremity. Limited rotation may indicate either anterior or posterior pathology because of abnormalities on either the femur or acetabulum. Restricted ROM is common in impingement, whereas excessive external rotation may be indicative of instability because of iliofemoral or capsular deficiency ( Fig. 41.2 ). Ischiofemoral impingement can be assessed by recreating pain in the trailing leg with an exaggerated long step and the ischiofemoral impingement test ( Fig. 41.3 ). Pain with hip flexion only with a prominent anterior inferior iliac spine (AIIS) is potentially indicative of subspine impingement involving contact between the AIIS and the femoral neck and may lead to failure if only the femoral side is treated during a FAI decompression surgery. Iliopsoas impingement is seen when pain is reproduced with a resisted straight leg raise in addition to tenderness over the iliopsoas tendon may also provide useful information when combined with tendon sheath injections, as it may indicate labral pathology secondary to soft tissues rather than osseous impingement alone. ,
Microinstability because of ligamentous laxity or a patulous capsule can be evaluated through various tests and may necessitate more deliberate capsular management during hip arthroscopy. In cases of suspected instability, iliofemoral ligament testing can be performed via the external rotation log-roll test or dial test. In those instances with an incompetent iliofemoral ligament or capsule, the hip will not return to a more neutral station following release of a rotational moment about the foot. , Ligamentum teres testing can be conducted by flexing the hip to 70 degrees with 30 degrees of abduction with maximum internal and external rotation. Anterior apprehension testing can be performed with the patient lying supine at the end of the bed with the hip extended and externally rotated ( Fig. 41.4 ). This can also be accomplished in a prone position with the hip extended and externally rotated. A positive test is represented by a feeling of apprehension, which can be improved with a posteriorly directed force at the anterior hip. ,
A systematic approach to the use of preoperative imaging is critical in helping identify the nuances in hip pathology and correctly guiding treatment when correlated with the patient’s history and physical examination. , The vast majority of hip pathology can be readily identified on standard anteroposterior (AP) pelvis, Dunn lateral, and false profile views, but frequently advanced imaging is necessary.
The AP radiograph should be carefully assessed for evidence of osteoarthritis and joint space narrowing. Patients with joint space less than 2 mm have been shown to have increased complications following hip arthroscopy, including early conversion to total hip arthroplasty. , , Acetabular dysplasia is defined as a lateral center edge angle of less than 20 degrees and borderline dysplasia from 20 to 25 degrees ( Fig. 41.5A ). Overcoverage of the femoral head and acetabular version abnormalities causing pincer-type lesions can be noted by the relation of the acetabular fossa with the ilioischial line and the presence of a crossover sign ( Fig. 41.5B ). Overly anteverted acetabula will display an anterior wall that does not cross the posterior wall before the lateral sourcil, with a posterior wall that extends lateral to the center of the femoral head ( Fig. 41.5C ). Limited to no anterior acetabular resection should be performed in these cases because iatrogenic instability can occur because of anterior escape of the femoral head from the acetabulum postresection. , Global acetabular retroversion with a deficient posterior wall sign and ischial spine sign ( Fig. 41.5D ) should be carefully distinguished from anterior overcoverage, as the version abnormalities may be best treated with a reorientation PAO rather than an aggressive rim trim that may cause the acetabulum to become volume-deficient and is associated with decreased survivorship at ten years (23% vs. 79%). , , This can be challenging, and often requires additional advanced imaging to accurately distinguish these features.