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Abstract
Introduction Athletic groin pain requiring surgery remains a diagnostic and therapeutic challenge. This systematic review aims to identify the most common causes of groin pain in athletes requiring surgery. Additionally, it aims to further characterise their susceptible athlete profiles, common physical examination and imaging techniques, and surgical procedures performed. This will enable the orthopaedic sports medicine clinician/surgeon to best treat these patients.
Materials and methods The electronic databases MEDLINE, PubMed and EMBASE were searched from database inception to 13 August 2014 for studies in the English language that addressed athletic groin pain necessitating surgery. The search was updated on 4 August 2015 to find any articles published after the original search. The studies were systematically screened and data were abstracted in duplicate, with descriptive data presented.
Results A total of 73 articles were included within our study, with data from 4655 patients abstracted. Overall, intra-articular and extra-articular causes of groin pain in athletes requiring surgery were equal. The top five causes for pain were: femoroacetabular impingement (FAI) (32%), athletic pubalgia (24%), adductor-related pathology (12%), inguinal pathology (10%) and labral pathology (5%), with 35% of this labral pathology specifically attributed to FAI.
Conclusions Given the complex anatomy, equal intra-articular and extra-articular contribution, and potential for overlap of clinical entities causing groin pain leading to surgery in athletes, further studies are required to ascertain the finer details regarding specific exam manoeuvres, imaging views and surgical outcomes to best treat this patient population.
- Groin
- Hip
- Surgery
- Review
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Introduction
Accurate clinical diagnosis and appropriate management of groin pain among athletes remain a significant challenge.1 This difficulty is often attributed to the complex anatomy of the hip/groin region, as well as to the extensive and occasionally overlapping extra-articular and intra-articular possible differential diagnoses.2 ,3 Whether acute or chronic in nature, athletic groin pain can be multifactorial (approximately 27% of cases).1 ,4 ,5 It is often triggered and/or exacerbated by sporting activities with substantial lower-body involvement—specifically, those requiring rapid accelerations/decelerations or frequent changes in direction—and presents along a spectrum from mild symptomatology causing training absences to career-altering disability.2 ,3
The prevalence of hip/groin injuries among athletes is dependent in part on the sport, age group and level of competition, among other factors. For example, 5–9% of hip/groin injuries are found in high school athletes,6 ,7 3–11% in those competing at an Olympic level,8 and as high as 10–18% attributable to those participating in elite soccer alone.9 The incidence of hip/groin injuries among elite soccer players is 1.1 groin injuries/1000 h of athletic activity.10 Hölmich et al11 reported that greater than 50% of groin pain in athletes originated from the adductors, iliopsoas or abdominal musculature.
Within orthopaedic sports medicine, a solid understanding of surgical aetiologies, injury rates, at-risk sports and patient populations as well as an approach to diagnosing and treating hip/groin pain in athletes is evolving. As such, this systematic review aims to elucidate this information to better identify groin pain in athletes requiring surgery while defining clinical markers that may highlight the need for surgical intervention.
Materials and methods
Search strategy
The search terms ‘athlete’, ‘groin’, ‘hip’, ‘pain’ and ‘surgery’ were entered into EMBASE, MEDLINE and PubMed databases using various combinations on 13 August 2014, and repeated on 4 August 2015 to find any additional articles published in the previous year to identify literature related to the surgical treatment of groin pain in athletes. A table outlining the search strategy is presented in online supplementary appendix 1. The research question and individual study inclusion and exclusion criteria, determined a priori, were used to include studies that: (1) were at all levels of evidence; (2) involved human participants of all ages; (3) were in English; (4) involved active patients and/or athletes at all levels of competition from recreational to professional; (5) had hip and/or groin pain due to sports/activity; and (6) underwent operative intervention for sport-related groin pain.
Supplementary appendix 1
Exclusion criteria were: (1) any non-surgical treatment studies (eg, conservative treatment, technique articles, cadaver studies, review articles, etc); (2) patients with unrelated diagnoses and/or groin/hip pain not due to sports such as foreign body, tumour, septic joint, etc; (3) case reports; and (4) studies that used the same patient population in order to avoid duplication of patients in the data analysis. In these cases, the study with the larger patient population was included. If a follow-up study of the same patient population was identified, the more recent study was included.
Study screening
The titles, abstracts, and full texts of all retrieved studies were screened independently and in duplicate by two reviewers (MJP and SH). Throughout this process, if at any point one reviewer believed an article should proceed to the next stage, it was included to ensure thoroughness. Any disagreements at the full text stage were discussed between the two reviewers, and a third reviewer (DdS) resolved any conflicts. The references of those studies satisfying all inclusion criteria were additionally screened to capture any studies that may have evaded the initial search strategy or screening process.
Data abstraction
Two reviewers (MJP and SH) independently and in duplicate abstracted all relevant study data from the studies meeting all inclusion criteria, and recorded this in Microsoft Excel (2013). Demographic information included author, year of publication, sample size, study design, level of evidence and patient demographics (ie, sex, age, affected hip, etc). In addition, we abstracted the top five most common data on: (1) aetiology of hip/groin pain; (2) type of surgery performed for each respective aetiology; (3) sports causing hip/groin pain in athletes; (4) physical examination manoeuvres used to diagnose hip/groin pain; and (5) imaging modalities (and views) used to identify hip/groin pain-causing pathology. Efforts were made to individually abstract specific aetiologies of groin pain within each study for an accurate analysis. For example, for inguinal-related groin pain, we separated incipient/Sportman's hernia/athletic pubalgia from traditional hernias (ie, protrusion of an organ through defective connective tissue). If possible, pathologies were characterised according to the Doha Consensus on terminology for groin pain in athletes.12 Individual conditions, such as femoroacetabular impingement (FAI) or labral injuries, were included as their own group rather than use of the broad term used in the Doha agreement to describe both of these as ‘hip related groin pain’.12 Despite the Doha agreement suggesting against the use of the terms ‘Sportsman's hernia/athletic pubalgia’, we included this category due to the frequent use of these terms within the literature included in our review.12
Statistical analysis
A weighted κ was calculated for each stage of article screening in order to evaluate inter-reviewer agreement.13 Agreement was categorised a priori as follows: κ>0.61 to indicate substantial agreement, 0.21<κ<0.60 to indicate moderate agreement, and κ<0.20 to indicate slight agreement.13 All studies were assessed using the GRADE assessment, which classified studies as very low, low, moderate or high quality evidence.14 Additionally, study quality was assessed using the Cochrane risk of bias assessment tool for RCTs, and the MINORS assessment for non-randomised investigations.15 ,16 Descriptive statistics such as means, ranges and measures of variance (eg, SDs, 95% CIs), where appropriate, were presented.
Results
Systematic search
On removing 211 duplicate studies from the initial 3500 studies found from our electronic database search, 3289 proceeded to systematic screening, with 66 studies eventually included. Two additional studies were provided by a content expert (figure 1). The search was updated on 4 August 2015 to include additional articles that had been published since the original search. A total of five studies were added as a result of the updated search. The data in each of the 73 studies were not reported in a consistent manner and there were no direct prospectively collected comparison data between multiple studies; therefore, a meta-analysis was not feasible. There was variability between studies regarding surgical technique and reporting of outcomes, among other variables. Of the 73 studies included, there was one randomised controlled trial (RCT), 14 cohort studies, one case–control study and 57 case series.3 ,17–88 Relevant data were available from studies conducted in North America, Europe, Asia and Australia (see online supplementary appendix 2). The reviewers had excellent agreement on the title, abstract and full-text screening stages with κ values (and 95% CI) of 0.89 (0.86 to 0.91), 0.83 (0.76 to 0.91) and 0.86 (0.81 to 0.92), respectively. The quality of evidence for the included studies was typically low, with 11 studies classified as very low quality, 48 classified as low, 13 as moderate and 1 as high. MINORS score results for non-randomised studies revealed a generally low quality of evidence with respect to the included investigations, while the one included RCT had a moderate risk of bias with respect to the Cochrane RoB assessment (see online supplementary appendix 3).
Systematic search of the literature addressing causes of groin pain in athletes requiring surgery.
Supplementary appendix 2
Supplementary appendix 3
Patient demographics
This review examined data across a total of 4655 patients treated surgically for their sports-related groin/hip pain. The athletes in this review were a mean age of 27.4 years (range: 13–48 years) and 20.5% were female. The average follow-up period was 37.3 months (range: 1–492 months).3 ,17–88
Study data
Overall, there was an equal (50%) distribution between intra-articular and extra-articular causes of athlete groin pain requiring surgery. Over 80% (3895/4656) of the causes of groin pain requiring surgery in athletes was attributed to one of five gross aetiologies: FAI (32%), athletic pubalgia (24%), adductor-related pathology (12%), inguinal-related pathology (10%) and labral pathology (5%) (table 1).3 ,17–88 Of note, the remaining 20% of surgical causes of groin pain in the athlete population comprise a variety of aetiologies, most reported as small case series, and all with an incidence less than 2%. None of these aetiologies occurred with enough frequency to warrant its own category. The group of reported aetiologies comprising this 20% included (in no specific order): snapping hip, myositis ossificans, obturator nerve entrapment, intra-articular loose bodies, rectus femoris avulsion, degenerative joint disease, acetabular fracture, femoral neck stress fracture, proximal hamstring tear and traumatic hip dislocation. Athletic pubalgia, sports hernia and incipient hernia were all considered equivalent and grouped under ‘athletic pubalgia’ within this analysis as they are not true hernias. On the other hand, inguinal hernias, being protrusions of organs through defective connective tissue, were considered in the inguinal pathology section. Table 1 further subdivides each gross aetiology by subtypes of tendinitis, strain, avulsion, rupture, etc where appropriate and stated. There were insufficient data to ascertain how many patients presented with concomitant pathologies, though we can report that 76 of 220 with labral pathology had concomitant FAI (table 1). Nerve entrapment, be it femoral, genitourinary, ilioinguinal, obturator, etc, was not found to constitute a significant source of athlete groin pain requiring surgical intervention (0.6%).
Top five surgical causes of groin pain in athletes
Of these top five aetiologies, the majority were reported in young patients in their mid-20s (table 1). Athletic pubalgia, adductor-related pathology and inguinal pathology were almost exclusively reported in male patients, with rates of 98.0%, 99.2% and 96.6%, respectively (table 1). Though seldom reported, where available, there did not seem to be any effect of the athletic level (ie, professional, competitive, recreational, etc) on type or severity of the cause of athlete groin pain (figure 2). Though not always reported across all studies, ice hockey and soccer were the most prevalent cause of groin pain due to FAI (67 athletes each) and labral pathology (31 athletes). Soccer was the most prevalent cause of athletic pubalgia (368 athletes), adductor-related pathology (298 athletes) and inguinal pathology (52 athletes) (table 2).3 ,17–88
Top three sports causing top five surgical causes of groin pain in athletes
Athletic level associations with top five surgical causes of athlete groin pain. FAI, femoroacetabular impingement; professional—players from a professional sporting league; competitive—players described as ‘competitive, collegiate, varsity, high school, high-level, elite, and national’; recreational—players described as ‘recreational, club, casual, and amateur’.
Diagnosis
Almost 90% of the physical examination techniques performed to diagnose surgical groin pain in the athlete comprised two manoeuvres: gross palpation of the groin (76%) and the flexion, adduction, internal rotation test (ie, FADIR or anterior impingement test) (12%).3 ,17–88 The flexion, abduction, external rotation manoeuvre (FABER) accounted for 6% of the physical examination techniques performed. The two most common imaging modalities used to diagnose groin pain in the athlete were: (1) MRI at 40% (1870/4655), with 8% (145/1870) specifically using an arthrogram; and (2) plain radiograph at 33% (1545/4655), with 51% (795/1545) of studies not reporting the specific views used (table 3).3 ,17–88
Top five imaging modalities (and views were applicable) used to diagnose surgical causes of groin pain in athletes
Treatment
Hip arthroscopy for FAI was performed in 97% (1466/1510) of patients, and was also utilised exclusively for any labral pathology—be it in isolation or in association with other entities. Athletic pubalgia was treated with open surgical procedures 70% of the time (786/1122), with 61% (482/786) of those procedures using mesh reinforcement. The majority (70% or 403/570) of adductor-related pathology was surgically treated with complete adductor tenotomy, and less than 1% of patients were treated with adductor reattachment procedures. Overall, 36% (169/473) of all inguinal pathology was treated with open hernia repair and 39% (183/473) with laparoscopic hernia repair (table 4).3 ,17–88
Interventions used to treat surgical causes of groin pain in athletes
Discussion
Key findings
The key finding from this review was the equal contribution of intra-articular and extra-articular causes of groin pain leading to surgery reported in the current literature. Specifically, over 80% of athletic groin pain requiring surgery in the included evidence was attributable to five pathologies: FAI, athletic pubalgia, adductor-related, inguinal-related and labral-related. Two of these categories (adductor-related and inguinal-related) are defined within the Doha agreement, while both FAI and labral-related groin pain would fall under the Doha agreement category of ‘hip-related’. The term athletic pubalgia was suggested as an inappropriate term for classification by the Doha agreement; however, it was included in our review due to its frequent use in the published literature to date.12 The most common physical exam manoeuvres used to diagnose such pathology were gross groin palpation (76%) and the FADIR anterior impingement test (12%), respectively, with MRI (40%) and plain radiograph (33%) constituting the most common diagnostic modalities employed.3 ,17–88 Intra-articular causes (ie, FAI and labral) were almost exclusively treated with arthroscopic procedures, whereas extra-articular causes (ie, athletic pubalgia and adductor-related) were almost exclusively treated with open or miniopen/percutaneous surgical procedures. Inguinal-related pathology was addressed equally between laparoscopic and open surgical approaches.
Strengths
This is the first systematic review that addresses the surgical causes, diagnostics and treatment options of athlete groin pain. The extensive search strategy and duplicate systematic screening approach ensures inclusion of the currently best-available evidence herein. Our large sample size (ie, greater than 4000 patients) and inclusion of studies conducted globally contribute to the generalisability of our findings and limit selection bias.
Limitations
Our major limitations stem from incomplete and/or inadequate reporting across the individual studies included. Though we often aimed to abstract data to further subdivide pathology (table 2), only very limited data were reported on athlete demographics and levels of competition (figure 2),1 views/sequences used in particular imaging modalities (table 3), and specifications of technical procedures performed. For example, though we aimed to characterise any effect on leg dominance in surgical causes, given that in all-comers 68% of athlete groin pain is attributable to the dominant leg,11 this was often not reported or easily ascertained. Similarly, though ‘palpation’ was often reported as a physical exam manoeuvre performed, the included studies did not define exactly and consistently what structures were palpated or their technique. We are also limited by a lack of consistency in the included literature on nomenclature (often resulting in nonspecific and broad terminology) and diagnostic criteria for such pathology.1 For example, ‘athletic pubalgia’ and ‘sport's hernia’, in the current study, were included as the same pathology. However, it is not uncommon in studies to refer to lists of groin pain and include athletic pubalgia and sport's hernia as separate entities (with no definition of these terms). To avoid this limitation in the future, studies on athletic groin pain should adhere to an agreed on set of terminologies for groin pain pathologies, such as the Doha agreement terminology for athletic groin pain.12 An additional limitation of this study stems from the inclusion of mostly case series, which precludes us from drawing inferences to the larger population of athletes with groin pain requiring surgery. From our examination of the data, we did not report return to sport rates as an outcome, as there were too many potential biases in the reporting of these that would not accurately reflect true return to play seen in practice.
Future directions
Going forward, defining a consistent physical exam approach will be required,89 especially given the equal contribution of intra-articular and extra-articular pathology requiring surgery. Our recommendation is consistent with the Doha agreement meeting on definitions and terminology in athletic groin pain, which states that there is currently no gold standard for history, examination or imaging for diagnosing athletic groin pain.12 This is especially important, given that many studies included in the current review often commented that ‘physical examination was conducted’, but did not note their specific protocol. Though Hölmich et al1 classify the majority of athlete groin pain into adductor-related, iliopsoas-related or rectus-abdominus-related, neither of the last two pathologies were top causes of pain requiring surgery. Rectus-abdominus-related pain was not reported as requiring surgery within any of the included studies. Thus, a more nuanced approach is needed to isolate those who may benefit from surgical intervention. The emphasis on purely gross palpation and the anterior impingement test as the dominant physical examination techniques in this athlete population was somewhat surprising. Across the 73 included studies, other reported, albeit inconsistently, physical examination manoeuvres included: active/passive range of motion, muscle strength testing, ‘squeeze test’, active single-limb pelvic elevation, Thomas test and femoral slump test. Though the FABER and FADIR impingement tests appeared in the top four physical examination tests, other manoeuvres such as the log-roll and trochanteric tenderness were not reported.
Physical exam tests for FAI and/or labral pathology were evaluated by Tijssen et al,90 who concluded that insufficient data exist to reliably confirm or discard FAI and/or labral pathology with the physical examination alone. Thus, further evaluation of these tests is needed to acquire the knowledge and be able to implement them to enhance the diagnostic repertoire of the clinician. For example, though asymptomatic, decreased range of motion is often the first finding associated with radiographic and MRI pathological hip lesions, it is not often documented.91 Moreover, further defining the physical examination is especially important, given that each of these top five surgical causes may mimic each other. Sansone et al92 recommend that every athlete presenting with groin pain be evaluated for hip impingement, given the high association with athletic pubalgia and intra-articular disorders, and the documented inferior outcomes from failing to address intra-articular pathology. Larson et al3 further support this, noting that in circumstances where both intra-articular and extra-articular pathologies exist, surgically addressing only one of either the intra-articular or extra-articular pathology leads to inferior results, whereas in situations where both are addressed, outcomes are significantly improved.
Now that the ‘top’ diagnostic modalities and surgical techniques described within the literature have been determined, further studies should aim to define optimal sequences/views for such modalities, as well as hallmark radiological features for each to help differentiate them. Imaging and clinical examination findings that led to the positive diagnosis of the injury were seldom described, which justifies a need for in-depth investigations regarding the diagnostic indications for these pathologies. Branci et al93 ,94 have shown that MRI has equal limitations in assessing long-standing groin problems in athletes as the aforementioned limitations of the physical examination for athlete groin pain. Future efforts should aim to evaluate the feasibility of the imaging approach to diagnosis. For many of these surgical causes of athletic groin pain, a ‘gold standard’ imaging modality does not yet exist.9 ,95–98 The Doha agreement also indicates a need for standard imaging protocol when assessing athletic groin pain.12 Studies specifically designed to assess the subjective and objective outcomes and complications from surgical intervention would also be invaluable to understanding athletic groin pain. Also, ascertaining clinical outcomes in patients with isolated versus combined pathology (be it intra-articular and/or extra-articular in nature) would prove important. The use of a Patient Reported Outcome Measure (PROM) is recommended for all future clinical studies.99–101 The Doha agreement suggests a number of validated outcomes for young to middle-aged athletes with hip-related groin pain, including Hip and Groin Outcome Score (HAGOS), Hip Outcome Score (HOS), International Hip Outcome Score (IHOT)-12 and IHOT-33, which should be considered in future clinical investigations.12
The most common causes of athlete groin pain leading to surgery reported within the literature occur in athletes in their mid-20s. The significant male predominance of athletic pubalgia, inguinal pathology and adductor-related pathology in these included investigations warrants further attention to make informed inferences with respect to the correlation between age, gender and these pathologies. Such studies may assist with the development of preventative programmes and rehabilitation protocols and limit the burden groin injuries place both on the individual athlete and greater team level where applicable. We know that athletic pubalgia is approximately 10 times more common in men than in women, and not due to the level or type of sport, but more likely attributable to strength differences and anatomical pelvic and force distribution differences between both genders.102–104 This is possible, though unproven, for adductor-related and inguinal-related pathology as well. The difficulties to identify the precise diagnosis treated in the examined 73 papers underlines that the terminology of hip and groin injuries in athletes needs to be more specific. Adherence to international consensus terms would be extremely helpful to move the field forward,12 since the included studies provided inconsistent use of terminology when classifying pathologies associated with athletic groin pain.
Conclusion
Given the complex anatomy, equal intra-articular and extra-articular contribution, and potential for overlap of clinical entities causing groin pain leading to surgery in athletes, a systematic physical examination including palpation and the FADIR impingement test, complemented by MRI and/or plain radiograph, is most commonly used to differentiate pathology within the current literature. Though intra-articular causes are generally treated by arthroscopy and extra-articular causes by open procedures, further studies are required to ascertain the finer details regarding specific exam manoeuvres, imaging views and surgical outcomes to best treat this patient population.
What are the findings?
The top five causes for pain were: femoroacetabular impingement (FAI) (32%), athletic pubalgia (24%), adductor-related pathology (12%), inguinal pathology (10%) and labral pathology (5%).
More than 90% of the physical examination manoeuvres used to achieve a diagnosis included: gross palpation (77%) and the flexion, adduction and internal rotation test (ie, anterior impingement test) (13%).
The two most common imaging modalities used to diagnose groin pain in the athlete were: (1) MRI at 40% (1870/4655), with 8% (145/1870) specifically using an arthrogram; and (2) plain radiograph at 33% (1545/4655).
Intra-articular causes were almost exclusively treated with arthroscopic procedures, whereas extra-articular pathologies were almost exclusively treated with open or mini-open/percutaneous surgical procedures.
Given the complex anatomy, equal intra-articular and extra-articular contribution, and potential for overlap of clinical entities causing groin pain leading to surgery in athletes, a systematic physical exam including palpation and the FADIR impingement test, complemented by MRI and/or plain radiograph, is most commonly used to differentiate pathology.
How might it impact on clinical practice in the future?
Arthroscopy is the predominant treatment method described for intra-articular causes of groin pain within the literature and continues to grow in popularity.
Over 80% of athletic groin pain requiring surgery described in the literature was attributable to five pathologies: FAI, athletic pubalgia, adductor-related, inguinal-related and labral-related.
A consistent physical examination and imaging approach should be determined to diagnose athletic groin pain, which should consist of, but not be limited to, gross palpation, FADIR, FABER, MRI and plain radiograph.
Moving forward, the international consensus on terminology for hip and groin injuries proposed by Weir et al should be adopted, as the studies included in the current review vary greatly in their terminology use.
Given the relatively equal contribution of both intra-articular and extra-articular causes of groin pain in athletes requiring surgery within the literature, a thorough history and physical examination is essential to avoid missing concomitant pathology and decrease the need for revision surgery and its associated potential risks and morbidities.
Acknowledgments
The authors would like to thank Andrew Duong and Zakia Islam for their assistance in formatting and submitting this manuscript.
References
Footnotes
Contributors ORA, NS and DdS planned the study. MJP and SH performed article screening and data abstraction. DdS and MJP developed the manuscript. PH, NS, MJP and ORA reviewed and provided critical feedback for the manuscript. Research efforts were supervised by ORA.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.