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January 15, 2020
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Failed hip arthroscopy is manageable with nonoperative care, arthroplasty

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Hip arthroscopy is a unique and novel specialty within the field of joint preservation. One of the most common indications for it, femoroacetabular impingement, was first coined in 1999. Initially, femoroacetabular impingement was commonly addressed with open surgical hip dislocation, a procedure described by Reinhold Ganz, MD, and colleagues in 2001, which was considered the gold standard for surgical treatment of femoroacetabular impingement for much of the following decade. Only in the last decade did hip arthroscopy become more commonly performed for this indication. However, the anatomic complexity of the hip joint, including the proximity of neurovascular structures and the relative inelasticity of the surrounding ligaments, yielded a significant learning curve. Inevitably, surgeons undertaking hip arthroscopies face a subset of patients with continued complaints, sometimes referred to as failed hip arthroscopy syndrome. The growing popularity of hip arthroscopy has necessitated the development of specialized referral centers, which must act as a resource to the surgeon facing a patient complaining of continued pain after primary hip arthroscopy.

As challenging as primary hip arthroscopy can be, managing a patient with persistent pain following hip arthroscopy is more tangled. This challenge stems from the following factors:

  • the possible differential diagnosis is broad in the context of failed hip arthroscopy and identifying the etiology may require an extensive work-up with a multidisciplinary approach; and
  • procedures that are often performed during a revision hip arthroscopy are less commonly required during a primary procedure and demand a specific skill set.

This complexity has produced a funneling of patients with continued pain after hip arthroscopy to a handful of tertiary hip preservation centers that are equipped to manage failed hip arthroscopy syndrome. Such referrals reflect the challenges related to decision-making and technical aspects of the surgery, as well as the profound responsibility referring clinicians feel toward their patients. In turn, it is the responsibility of the tertiary center to serve as a resource to referring doctors and to collaborate to address these challenging cases. This article aims to provide a framework for managing patients with persistent pain after hip arthroscopy.

Major etiologies

The major etiologies for persistent pain after hip arthroscopy fall into the following five major categories: femoroacetabular impingement (FAI); instability; arthritis; other intra-articular pathologies; and extra-articular factors.

Impingement between the femur and acetabulum may damage the chondrolabral junction and disrupt the fluid suction seal required for normal function of the hip joint. Although residual cam is a common indication for a revision arthroscopy, it is important to acknowledge the existence of an over-resected cam lesion. Over-resection is more challenging to address than a residual cam and has led to worsened outcomes after revision procedures.

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Instability of the hip joint may be caused by both ligamentous laxity and bony abnormalities. General ligamentous laxity is evaluated using the Beighton score. It is generally agreed upon that a score higher than 4 indicates general ligamentous laxity. Instability due to bony abnormalities can be caused by either native or iatrogenic dysplasia.

It is especially important to evaluate the state of the cartilage within the hip joint. In current literature, the degree of arthritis has been repeatedly demonstrated to be directly related to poor outcomes following hip arthroscopy.

Other intra-articular etiologies include avascular necrosis (AVN), occult fractures and chondral defects.

Extra-articular factors may include pathology of the gluteal muscles and the peritrochanteric region, the iliotibial band, the iliopsoas tendon and the core musculature, as well as more distant locations, such as the lumbar spine. Unidentified femoral malrotation may also lead to persistent pain following a primary hip arthroscopy.

When it is uncertain whether the source of pain is intra- or extra-articular, intra-articular diagnostic injections may be administered. If these provide only partial pain relief, both intra- and extra-articular factors may be contributing to the pain.

Evaluation via imaging

A thorough radiographic evaluation is integral to the work-up for persistent pain after hip arthroscopy. Having a low-quality radiograph or an incorrect view that fails to demonstrate the patient’s pathology may lead to an incorrect diagnosis. The imaging work-up should maintain the same paradigm with the five possible categories: FAI; instability; arthritis; other intra-articular pathologies; and extra-articular factors (Table). Impingement can be evaluated using plain radiographs. However, if a more detailed imaging modality is required, CT with 3D reconstructions can be used. An associated re-tear of the labrum can be confirmed with a magnetic resonance arthrogram (MRA).

Radiographic indices, such as anterior center edge angle, lateral center edge angle and acetabular index, are widely used to characterize acetabular depth. It is important to distinguish between borderline dysplasia and frank dysplasia because an isolated arthroscopy in the presence of frank dysplasia may aggravate the instability and lead to exacerbation of the symptoms.

Hip joint arthritis should be routinely assessed using one of the various existing radiographic classifications. The clinical correlation, the intraobserver and interobserver reliability for each classification, are well documented in the literature. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a specific MRI sequence that demonstrates the integrity of the articular cartilage and can be used for assessing the level of osteoarthritis. Low indices suggest arthritic changes that may precede the radiographic presentation and could tip the scales towards hip arthroplasty.

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The imaging work-up for other pathologies is wide and should be directed toward the suspected etiology. Suspected AVN, occult fracture and other extra-articular soft tissue pathologies (eg, tendinopathy and nerve impingement) may be confirmed with MRI. Assessment of the bony architecture, including the femoral anteversion, may be better visualized with CT. Other important sources of information are the preoperative and postoperative reports on the course of the index procedure, as well as the notes and photos taken intraoperatively.

Conservative treatment

The first line of treatment for persistent pain after hip arthroscopy is conservative. For arthritic conditions of the hip, the American Academy of Orthopaedic Surgeons guidelines for conservative management strongly support NSAIDs, intra-articular corticosteroid injections and physical therapy. Conservative treatment for FAI includes activity modification, NSAIDs and physical therapy focused on improving strength and stability. Excessive stretching and range of motion are generally discouraged in the setting of FAI as these might aggravate symptoms. A large, multicenter randomized control study by Damian R. Griffin, MPhil, and his colleagues compared outcomes of patients undergoing hip arthroscopy and patients undergoing conservative treatment for FAI. Both patient populations showed improvement in quality of life; however, at latest follow-up, patients who underwent hip arthroscopy improved significantly more compared to patients who underwent conservative treatment. Evidence for conservative treatment in revision hip arthroscopy is scarce. Nevertheless, due to the mechanical nature of the pathology, this treatment modality usually fails to manage the symptoms.

Surgical treatment

For persistent pain after hip arthroscopy that is refractory to non-surgical measures, the major fork in the road is the decision between secondary hip preservation and conversion to arthroplasty, which depends largely on the degree of deterioration of the cartilage and subchondral bone. The decision-making algorithm for treating patients after failed hip arthroscopy utilizes the five categories of FAI, instability, arthritis, other intra-articular pathologies and extra-articular factors (Figure 1).

1. Shown is the treatment algorithm for femora over-resection and under-resection.

FAI management

After failure of conservative treatment in patients without significant OA, hip preservation may be divided into its sub-procedures. Resection of the femoral-head junction should be planned according to the type of asphericity. With the case of an under-resected cam deformity, the residual convexity should be managed with traditional femoroplasty that aims to achieve a perfect spherical femoral head. When managing over-resected cam lesions, the challenge is to create a sphere out of a concave lesion. Hence, a “salvage femoroplasty” should be carefully planned to restore the suction seal between the labrum and the femoral head. If the suction seal cannot be restored with osteoplasty, a reconstructive procedure may be considered. Depending on other factors, such as the age of the patient, level of arthritis and concurrent conditions, either osteoarticular allograft or total hip replacement may be the treatment of choice.

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Capsular complex

The capsuloligamentous complex of the hip joint works in synchrony with the other intra-articular structures to maintain the proper function of the hip joint. In patients with either soft tissue or bony instability, the integrity of the capsule is crucial because the other static stabilizers are compromised. Thus, capsular plication should be performed with any suspected form of instability. Most other cases could be managed with capsular repair (Figure 2). Capsular release should be reserved for cases in which tightness is the predominant symptom.

2. Capsular plication is shown. 3. Circumferential labral reconstruction is shown. 4. Periacetabular osteotomy is shown in anteroposterior (a) and obturator (b) radiographic views.

Labral tear

The primary goal in treatment of labral tears in the revision setting is to restore the suction seal. In revision cases, the native labrum is often degenerated or calcified. A previously repaired or debrided labrum is seldom amenable to secondary repair. Therefore, labral reconstruction is often indicated (Figure 3). It is important to assess the entire circumference of the labrum for findings that may compromise the suction seal, including re-tears, intrasubstance fraying and calcifications. Labral reconstruction may be performed segmentally, circumferentially or by augmenting the existing native labrum, a decision that should be made after careful assessment of the entire labrum. Selective labral debridement may occasionally have a role, if this can be done with maintenance of the suction seal.

Instability

Soft tissue sources of instability may include genetic ligamentous laxity, capsular attenuation, ligamentum teres tears and previous capsular resection. These may be treated with soft tissue solutions including capsular plication, capsular reconstruction with dermal allograft and ligamentum teres reconstruction.

Profound bony instability (ie, frank dysplasia or excessive femoral anteversion) cannot be addressed with soft tissue solutions alone. If not properly managed, the hip joint may deteriorate further following consecutive arthroscopies. Dysplasia has been repeatedly reported as a risk factor for OA over a long term. Thus, a concomitant pelvic osteotomy should be considered to address this acetabular deficiency (Figure 4). For excessive femoral anteversion with or without coxa valga, concomitant femoral osteotomy may be necessary. As hip arthroscopy and osteotomy are technically demanding, a multidisciplinary team may be required for these cases.

Arthritis and hip replacement

Evidence shows poor outcomes and high rates of reoperations following hip arthroscopy in the presence of OA. However, the decision whether to preserve or replace the hip is not always straightforward. In a young patient with persistent pain after hip arthroscopy with residual FAI and a labral tear, the presence of arthritis may tilt the treatment plan toward a hip replacement; however, at the same time, a hip replacement at a young age incurs the risk of multiple revisions during their lifetime. In contrast, in an older patient with persistent pain after hip arthroscopy, hip replacement may sometimes be considered even in the absence of significant arthritis.

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Other intra-articular pathologies

After ruling out impingement, instability and arthritis as the cause for refractory hip pain, treatment should follow a careful assessment. Intra-articular etiologies, including AVN, occult fractures and chondral defects, can sometimes be managed with hip preserving measures. AVN without subchondral collapse may be treated with arthroscopic-assisted core decompression and placement of bone graft within the core. In cases of more global femoral head involvement, the open lightbulb procedure with bone grafting may be indicated. Occult fractures and stress fractures may be managed with supportive hardware. Chondral defects may be managed with restorative techniques including osteoarticular allograft and autologous matrix-induced chondral substitution.

Extra-articular pathologies

Peritrochanteric disorders, such as tears of the gluteus medius and minimus, are common causes of refractory lateral hip pain. These may be treated with endoscopic or open repair, with or without graft augmentation. Iliopsoas impingement or snapping may cause persistent anterior pain. Ultrasound-guided diagnostic and therapeutic injection may be the first line of treatment. Endoscopic fractional lengthening may be used in refractory cases. Secondary tendinopathies associated with an intra-articular derangement can occur as described by Hilton’s law and may improve following successful management of the primary problem, and therefore must be differentiated from primary tendinopathies.

Core muscle injuries (alternatively known as sports hernias or sportsman’s groin) may be treated with repair of the rectus abdominis, adductor longus and/or transversalis. Finally, a rotation femoral profile may indicate femoral rotational osteotomy, either isolated or concomitantly with other procedures (eg, hip arthroscopy, pelvic osteotomy). Common distant sources for referred pain are the sacroiliac joint and the lumbar spine. The scope of this article cannot accommodate the wide treatment options for the above-mentioned conditions. However, these possibilities should always remain part of the decision-making algorithm in patients following a failed hip arthroscopy.

Preservation procedure outcomes

The evaluation, decision-making and technical aspects in secondary hip preservation procedures is enormously complex and current literature demonstrates that the outcomes for secondary procedures are more varied than for primary procedures. Nevertheless, meticulous work-up and patient selection combined with application of the surgical principles discussed here have yielded excellent improvement in patient symptoms and function after secondary procedures.

Arthroplasty after previous arthroscopy comes with specific technical complexities that have negatively affected outcomes of the arthroplasty, based on results of some studies. Specifically, there may be scarring of the soft tissues around the joint, such as the iliopsoas, tensor fascia lata, abductors and capsule. Furthermore, previous bony resections may complicate the arthroplasty procedure. For the above reasons, consideration may be given to performing the arthroplasty in a tertiary center that encompasses all aspects of revision hip preservation and arthroplasty.

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Evaluation of the patient with persistent pain after hip arthroscopy requires consideration of a wide differential diagnosis. To maintain organized workflow, patients with persistent pain following hip arthroscopy should be classified into the five categories discussed earlier A treatment algorithm is presented to clarify the decision-making in this patient population. Once the evaluation has been completed, treatment may be planned according to this flowchart. This complexity, along with the technical demanding nature of secondary procedures, may explain the funneling of patients to a small handful of tertiary hip preservation centers that are equipped to manage failed hip arthroscopy syndrome. It is the responsibility of the tertiary center to work collaboratively with the referring surgeon to assist in these challenging cases.

Disclosures: Domb reports he is a paid consultant and presenter/speaker for and receives IP royalties and research support from Arthrex. Bheem and Shapira report no relevant financial disclosures.