Portal Placement for Hip Arthroscopy

Abstract 

Hip arthroscopy is a well-established technique that has become a mainstay in the repair of bony and ligamentous injuries when conservative methods fail to return adequate joint mobility and function. The technique has both diagnostic and therapeutic utility and its use as a minimally invasive orthopedic surgery continues to advance. Several studies have suggested that arthroscopic surgical management has more favorable outcomes in certain circumstances when compared to hip-specific conservative measures. The approach to establishing adequate sites for portal placement is dependent upon recognizing the pertinent anatomy of the surgical site.  At the same time, the operator must be mindful of the desired views once access to the joint space has been obtained. Proper visualization of the desired joint region is critical to reducing the conversion of THAs into inherently riskier total joint procedures. Additionally, the neurovascular landscape of the groin presents technical challenges with the procedural approach, which requires significant skill to avoid vital structures in the area. Acetabular labral tears are frequently repaired with this type of operative management as techniques and approaches become more refined. Here, we present the case of a 24-year-old woman who is undergoing an arthroscopic anterior labral repair, highlighting both the anatomical landmarks and the access points for portal placement used in the procedure.

Keywords 

Orthopedics; portal placement; arthroscopy; joint diseases; groin; cartilage, articular.

Case Overview

Background

The evolution of hip arthroscopy and its utility has coincided with the rapid advancements in technology and user competency. Specialized equipment and a more thorough comprehension of hip pathology assisted the transition from a diagnostic procedure to a viable therapeutic modality.¹ Injury to the hip can cause a variety of intra-articular pathology; however, labral tears and degeneration in the context of femoroacetabular impingement (FAI), dysplasia, or trauma have become the mainstay of hip arthroscopy procedures.²  Labral tears are prevalent in patients with FAI, occurring commonly in active adults of all age groups with the anterosuperior labrum being frequently involved.^1, 3

This patient is a 24-year-old female who is undergoing reconstruction of an anterior labral tear. As techniques have improved, hip arthroscopy has become one of the preferred modalities to repair labral injury as it is minimally invasive and effectively relieves pain symptoms in comparison to non-operative management.⁴ Understanding proper portal placement is paramount in successfully establishing both safe and adequate access to the central and peripheral compartments required for surgery. In this case, three portals were used to establish adequate repair; however, upwards of 11 portal locations can safely be established without damaging vital structures.⁵ Most notably in this case, the structure most at risk for damage with portal placement is the lateral femoral cutaneous nerve (LFCN). The LFCN passes under the inguinal ligament and then bifurcates into two branches as it crosses over the sartorius muscle, leaving it in a vulnerable position for iatrogenic complications.⁶ The surgeon must also exercise caution with the incisions used for portal placement, not proceeding deeper than the subcutaneous fat given that the LFCN runs rather superficially.⁷ Therefore, identifying the anterior superior iliac spine, marking directly inferior, and proceeding lateral to this newly created plane will minimize risk of injury to the major nervous structures in the area.⁵

In the sequence of portal placement for this case, the anterolateral portal is established first. To identify this access point, the surgeon palpates the top of the greater trochanter, then proceeds slightly superior to the trochanter in the cross-sectional plane where an area devoid of bone can be appreciated. The posterolateral portal placement follows a similar path but is located inferior to the trochanter. A guidewire inserted into the joint space at the anterolateral portal is visualized under fluoroscopy and confirmed with the arthroscope once the portal is established. The anterior portal access is marked 1 cm lateral and below the intersection of the ASIS sagittal plane and the cross-sectional plane of the greater trochanter. In contrast to the anterolateral portal, the anterior portal enters the inner capsule of the joint via a blind stick from the outside while being directly visualized from the joint space with the established anterolateral arthroscope. Following these anatomical boundaries creates a systematic approach to portal placement while ensuring that vital neurovascular structures remain unharmed.

Focused History of the Patient

Patients with labral tears will generally present complaining of impingement-like symptoms including pain, clicking, catching, or decreased range of motion, particularly in flexion and abduction. Two primary lesions contribute to the pain syndrome of FAI. Cam, pincer, and mixed types of impingements are caused by irregularities of the interface between the femoral head and acetabulum. Cam type lesions are bony protrusions at the anterolateral head-neck junction, leading to an erosive disruption of the chondrolabral junction. Pincer lesions are caused by an over-coverage of the femoral head within the acetabulum with a resulting breakdown of the labrum and cartilage involved in the shear forces between the proximal fever; mixed type deformities are a combination of cam and pincer deformities, respectively. ^{2, 5, 8, 9} These symptoms can be the result of chronic, repeated compressive forces, athletics, old age, or can be of an acute nature as that found in traumatic events such as a motor vehicle accident or fall.¹ A particularly interesting finding in the history and physical exam is that some patients—particularly women—may find that their labral dysfunction has negatively impacted various aspects of their lives, including sexual intercourse.³ In many cases, there may not be a specific etiology of a patient’s hip pain, but the history correlated with physical exam findings are generally adequate enough to establish a clinical diagnosis prior to confirmatory imaging.¹⁰ 

Physical Exam

The pain associated with labral tears and impingement syndromes usually develops in a gradual manner, occurring at night and being provoked by prolonged sitting, running or pivoting.⁸ Patients with FAI and labral tears do not usually have significant deficits with simple movements such as walking, but it does significantly reduce range of motion of the hip, especially flexion. This can be provoked from maneuvers such as deep squatting or performing the FABER test during physical exam.¹ Various evaluation techniques, including anterior impingement, subspine impingement, lateral impingement, and posterior impingement maneuvers may be used to reproduce the pain and symptoms responsible for the patient’s chief complaint.¹⁰ Positive physical exam findings from these provocative tests are frequently sufficient to diagnose an impingement syndrome with confirmatory imaging to follow.

Imaging

Imaging studies in the context of hip pathology are especially useful in assessing the structural abnormalities leading to positive physical exam findings. The two most utilized modalities are an AP pelvis X-ray and magnetic resonance imaging (MRI). AP pelvis radiographs allow visualization of any dysplasia and evaluation of the pathognomonic “crossover sign” seen in FAI.^8, 10 This finding is then corroborated with a soft-tissue focused imaging modality such as MRI, which focuses on the chondral lesions created by the bony pathology assessed in the preliminary pelvis radiograph.

MRI has a relatively high efficacy in diagnosing labral pathology, having a sensitivity between 66–87% and specificity 64–79% when a direct MRI or conventional MRI is used.¹¹ Once a diagnosis has been established from the clinical picture created by the patient’s history, physical exam, and imaging, the decision must be made if conservative, non-operative management or surgical intervention should take place.

Options for Treatment

Hip arthroscopy is considered a second-line treatment in the initial management of labral pathology. Currently, the standard of practice is aimed at first utilizing non-invasive measures, including rest, stretches, strengthening, and targeted physiotherapy at the abnormal movement patterns that tend to be present in patients with FAI.⁴ Symptoms or continued loss of function persisting after an extended, multiple-month course of non-operative measures, surgical intervention is indicated.¹⁰

Rationale for Treatment

Arthroscopic management revolves around two main objectives: labral debridement or repair. Debridement is amenable to those patients who have failed to improve with nonoperative modalities and are also not candidates for repair.¹⁰ This technique is accomplished through removal of loose bodies or other obstructions within the capsule of the hip joint, thereby eliminating the impingement and improving range of motion. However, outcomes utilizing only debridement have been shown to be inferior to repair and reconstruction.¹⁰ One proposed mechanism highlights that debridement alone has a tendency to compromise the negative pressure interaction between the labrum and acetabulum, thereby reducing the inherent stability of the ball and socket joint.⁸ Recent literature supports a superior treatment response in patients receiving labral repair and reconstruction over simple debridement.^10, 12 Indications for labral repair also include symptoms that have failed with non-operative measures but contain a full-thickness tear at the labral-chondral junction. Labral repair and reconstruction maintain the integrity of the labral-acetabular junction while eliminating the impeding agent. Thus, debridement is less recommended for many conditions as repair proves to be better in the long-term. 

The literature supports the escalation of care to arthroscopy after conservative measures fail to improve symptoms. In comparison to non-operative management, surgical treatment has shown statistically significant improvement in outcomes over a 10 year period.⁴ There is currently a lack of longitudinal follow-up studies examining if these trends continue in the long term, but as technique and technology improve, research into their efficacy for longer time periods will likely follow.

Special Considerations

As previously mentioned, those who experience chronic pain from various hip pathology leading to impingement or pain syndromes involving the hip joint are favorable candidates for hip arthroscopy. These indications must be weighed with other pre-existing conditions that may make operative management more complicated and less likely to succeed. Such contraindications include advanced osteoarthritis, congenital dysplasia due to slipped capital femoral epiphysis or Perthes deformities, and other dysplastic features that indicate a larger structural instability that are not amenable to arthroscopy.² Through careful selection and open discussion with patients about their clinical prognosis, the clinician is able to mitigate complications that may arise during the procedure. Modifying risk factors in the preoperative setting reduces the chance of intraoperatively converting to open hip arthroplasty, which tends to carry worse results.¹³  Most of the complications arising from hip arthroscopy are related to the traction used to create space in the joint, and patients with conditions or ill-suited body habitus that are not amenable to hip traction for long durations would have to undergo special consideration if the procedure may cause more harm than benefit.¹⁴ Proper patient selection continues to be an important predictor for operative success, and the criteria for suitable arthroscopy candidates evolve in parallel with surgical advancements.

Discussion

Hip arthroscopy presents several technical challenges that require great familiarity with the anatomy and equipment for the procedure. Inherent to a rapidly evolving field is the technical acumen that can only be acquired through direct experience and not merely gleaned from observation. As noted in this case, the instruments in hip arthroscopy are generally longer and more flexible than traditional arthroscopic equipment, which can better accommodate the curvature of the ball and socket joint of the hip. The specialized nature of the equipment and joint geometry of this procedure presents a steep learning curve for budding surgeons. To compound the pressure, the poor outcomes associated with surgeon inexperience adds to the emphasis of obtaining numerous training opportunities. Alluded to in this case, a surgeon’s initial attempts at portal placement and operating through arthroscopy is not entirely intuitive, where the angles of visualization do not perfectly correspond to a two-dimensional plane. The instruments used in a common arthroscopic surgical kit are vastly different than that used in a standard orthopeadic surgical kit, and the proper maneuvering of the devices requires extensive repetition to become competent with their use in surgery.

It is evident that to ensure the highest number of positive outcomes, the surgeon must go through numerous procedural repetitions under the guidance of other physicians well-versed in the procedure. It is difficult to quantify the point at which a physician should become proficient with a surgical technique, but there are studies that have investigated the topic. A literature review found that once a surgeon had reached 30 cases of performing hip arthroscopy, there was a significant reduction in operative time and postoperative complications.¹⁵ This number should be considered cautiously as multiple, uncontrollable factors play a role in skill acquisition, but it reiterates the importance of repetition in ones training. With fewer opportunities to operate on live patients without formal training, it can be difficult to find an entry point for a newly-licensed surgeon to learn the necessary skills and nuances of hip arthroscopy and portal placement.  In order to allow a greater exposure to the procedure without the incumbent risks of surgery, simulators and cadaveric models may be utilized in future training endeavors. Several studies have found that these simulations can increase performance and familiarity with arthroscopy while improving the user’s skills without the need for live patients in the initial phase of the learning curve.¹⁶ However, once these obstacles have been overcome and the operator gains a relative acquaintance with the procedure, the benefits of hip arthroscopy outlined in this article can be readily achieved in a safe manner that can afford patients an improved quality of life. 

Equipment

A standard Arthrex hip arthroscopic repair and reconstruction kit with Nitonal guidewire provide the necessary basics to perform hip arthroscopy, but additional supplies may be necessary depending on the patient’s needs and the surgeon’s preferences.

Disclosures

Nothing to disclose.

Statement of Consent

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.