Best Practice Guidelines for Hip Arthroscopy in Femoroacetabular Impingement

Results of a Delphi Process

T. Sean Lynch, MD; Anas Minkara, MD; Stephen Aoki, MD; Asheesh Bedi, MD; Srino Bharam, MD; John Clohisy, MD; Joshua Harris, MD; Christopher Larson, MD; Jeffrey Nepple, MD; Shane Nho, MD, MS; Marc Philippon, MD; James Rosneck, MD; Marc Safran, MD; Allston J. Stubbs, MBA, MD; Robert Westermann, MD; J.W. Thomas Byrd, MD


J Am Acad Orthop Surg. 2020;28(2):81-89. 

In This Article


This Delphi process represents the first formally derived consensus-based guidelines for hip arthroscopy in FAI, with a total of 15 hip arthroscopists from 14 institutions in North America. Consensus was reached for the creation of BPG consisting of 27 preoperative recommendations, 15 intraoperative practices, and 10 postoperative protocols. The consensus initiative was prompted by the lack of standardization in the management of FAI including preoperative, intraoperative, and postoperative practices. This inconsistency between institutions and surgeons is largely due to the absence of high-level evidence; therefore, because of the paucity in the literature, expert consensus should be considered to provide provisional recommendations.

The approach to conservative care, such as activity modification, NSAIDs, and intraarticular steroid injections, is poorly described.[40] The groundwork for this process was laid out by the Warwick Agreement on FAI syndrome by Griffin et al, which consisted of 22 panel members and reached an international multidisciplinary agreement on the general diagnosis and management of FAI syndrome. The Warwick consensus did not delve into the specifics of surgical management, with the depth of published findings extending to the following: "Surgery, either open or arthroscopic, aims to improve the hip morphology and repair damaged tissue…. An arthroscopic approach may be preferable in many patients to allow a potentially more rapid recovery, but some of these procedures will require an open approach."[36] As such, this initiative builds on the foundation previously established by the Warwick Agreement.

The creation of these consensus-based recommendations is of critical importance because the use of hip arthroscopy, rather than mini-open or surgical dislocation for the surgical management of FAI, is becoming increasingly popular.[20] Our systematic review and meta-analysis demonstrated an exceedingly low clinical complication rate of 1.7% and revision surgery rate of 5.5%,[24] which is superior to traditional approaches.[15,41] A notable improvement was also demonstrated in all patient-reported outcomes (PROs).[24] Similarly, prospective multicenter studies by the Academic Network of Conservational Hip Outcomes Research (ANCHOR) group demonstrated a major complication rate (complications require invasive surgical or radiologic intervention, associated with long-term morbidity, or are life threatening) of 0.5% in hip arthroscopy compared with 7% in periacetabular osteotomy.[42] Accordingly, the consensus of our working group is that hip arthroscopy should be the standard of care for the surgical management of arthroscopically accessible or classic FAI (Table 6, Supplemental Digital Content, with 100% agreement.

Regarding preoperative recommendations, 100% consensus was obtained for the avoidance of opioid prescription. Menendez et al[43] demonstrated that preoperative opioid misuse is associated with increased morbidity and mortality after elective procedures in orthopaedic surgery. Total hip and knee arthroplasty literature has shown that patients taking opioids before surgery continue to use opioids postoperatively.[44] Moreover, presurgical opioid use in shoulder arthroplasty resulted in markedly lower shoulder function scores,[45] akin to adverse postoperative self-reported outcomes in spine surgery.[46]

Preoperative radiographic measures have also been demonstrated to affect postoperative outcomes. Philippon et al[47] showed that patients with a joint space <2 mm, or >50% joint space narrowing, had markedly lower postoperative PROs and a high failure rate (82%) at the last follow-up, including conversion to total hip arthroplasty. Functional and satisfaction scores have also been shown to differ markedly between patients with and without osteoarthritis at the 1-year follow-up.[48] In addition, patients with a higher preoperative Tönnis grade are at a markedly increased risk for subsequent total hip arthroplasty (P = 0.03).[49] Accordingly, among the contraindications to the arthroscopic management of FAI which reached consensus by the group are (1) joint space narrowing ≤2 mm along the lateral/medial sourcil (80%), (2) osteoarthritis (80%), (3) Tönnis grade ≥2 (87%), and (4) obesity to where access cannot be obtained (Table 6, Supplemental Digital Content, Saltzman et al[50] showed lower satisfaction scores for obese patients compared with normal body mass index patients and less improvement in PROs. Finally, obese patients are at markedly higher risk for conversion to total hip arthroplasty (odds ratio 2.2) and revision arthroscopy (odds ratio 4.6).[51]

Furthermore, the group reached consensus for early surgical intervention, that is proceeding with hip arthroscopy before completing the full duration of conservative treatment, in the presence of an alpha angle >65° (100%), which is a measure of asphericity of the femoral head.[52] This recommendation was supported by a systematic review which revealed that an increased baseline alpha angle is associated with progression of labral tearing and osteoarthritis; however, no specific threshold was established.[23]

For intraoperative practices, there was absolute consensus (100%) on whether labral repair or refixation, as opposed to only labral débridement, should be performed. As demonstrated by Krych et al[53] in a randomized controlled trial (RCT) and Larson et al[54,55] in a prospective cohort study, patients undergoing repair exhibited markedly higher PROs at follow-ups up to 3.5 years.

Regarding intraoperative bone resection, 100% agreement was attained for guiding resection in cam impingement by reestablishing the femoral head-neck slope or junction (Table 6, Supplemental Digital Content, Multiple biomechanical studies in cadaveric specimens have shown that once bone resection is initiated, the mean peak load to fracture is sustained up to 30% removal of the femoral head-neck junction.[56,57] However, once 50% resection is reached, the peak load is markedly reduced (P < 0.05).[57]

Further intraoperative practices which reached consensus include performing capsular plication in the setting of a patient with borderline dysplasia, severe ligamentous laxity/hypermobility, or Ehlers-Danlos syndrome (Table 6, Supplemental Digital Content, (80%). Although there is currently insufficient evidence to support the use of capsular plication in FAI, Larson et al[58] reported this procedure as a predictor of improved outcomes after revision arthroscopic surgery for residual FAI.

Regarding postoperative rehabilitation, there remains a notable paucity of literature in this area because of the lack of prospective studies or RCTs. Expert opinion has been predominantly published in this field, and an assessment of protocols reveals four main phases: (1) maximum protection and mobility, (2) controlled stability, (3) strengthening, and (4) return to sport.[59–63] Of relevance, a preoperative physical therapy session (prehabilitation) has become more prevalent in many orthopaedic protocols, with 60% of surgeons in our group recommending prehabilitation. An RCT with patients scheduled for the arthroscopic management of FAI used one preoperative and six postoperative physiotherapy sessions compared with the controls (no rehabilitation) and did not observe any notable between-group differences at postoperative week 24.[64] However, this trial was ceased because of slower than expected recruitment and funding constraints.

The Delphi process resulted in 100% agreement with the recommendation to include a postoperative rehabilitation protocol consisting of the aforementioned phases. Consensus was also reached (87% agreement) to recommend a minimum duration of 3 months for postoperative rehabilitation. Byrd and Jones assessed arthroscopic femoroplasty in the management of cam-type and combined FAI. As part of this study, a structured rehabilitation protocol was continued for 3 months, and patients demonstrated a mean 20-point improvement in the Harris Hip Score, with a total of 83% reporting improvement.[65] Of note, full bony remodeling requires 3 months, which might necessitate precautions for torsional or high-impact forces.[66]

Strength and Limitations

Several limitations must be considered when implementing these BPG. The lack of high-quality studies assessing interventions in the arthroscopic management of FAI necessitates the inclusion of consensus-based expert opinion in addition to evidence-based guidance. By definition, BPG depend on formally derived consensus from experts, which is informed but not completely reliant on the available clinical evidence.

As indicated previously, this Delphi process represents the first national, formally derived, consensus-based guidelines for hip arthroscopy in FAI. This approach was specifically used because it has been extensively used in the peer-reviewed literature. No American Academy of Orthopaedic Surgeons consensus[67] was possible because of the existing lack of evidence in the FAI literature, thus necessitating an expert opinion/consensus statement. As additional evidence becomes available in the literature, these guidelines will be updated accordingly.

A final limitation of this study is the focus on the arthroscopic management of FAI. Certainly, there remains a place for open FAI treatments including complex or nonfocal disease (posterior cam, residual slipped capital femoral epiphysis, and Perthes deformities) and major acetabular and/or femoral version abnormalities. Although the authors recognize the role of open surgery in FAI, the standardization of these interventions is beyond the scope of this study.