Groin Injuries









Introduction



Bruce Charles Twaddle, BHB, MBChB, FRACS
Kristian Thorborg, PT, MSportsphty, PhD

Introduction


The anatomy of the pubic symphysis region makes it a diagnostic challenge because of the confluence of numerous musculoskeletal attachments, a variety of potential weaknesses in the abdominal wall and its close proximity to both the symphysis pubis and the hip joint.


Groin pain and injury are terms used to describe problems that present with pain in this general region. The complex nature of the anatomy of this region and the close proximity of many anatomical structures that could be the source of pain in this area, make isolating the exact source of pain felt in the lower abdominal or groin region very difficult. The often insidious nature of the onset of pain with a minor initiating injury and the referral or associated pain into the symphysis, the groin or adductor region and towards the hip makes pain and symptoms in this region a diagnostic dilemma. Consequently such terms as abdominal strain, Athletic pubalgia, sportsman’s hernia, Gilmore’s groin, hockey goalie syndrome, and osteitis pubis can all be attributed to the same or different injuries in this region. As a result “groin pain” has been a curse for athletic trainers, physiotherapists, sports physicians, orthopedic surgeons and musculoskeletal radiologists alike with individual biases and experiences. This has led to varying schools of thought as to the true origin of pain of the same presenting characteristics and inevitably varying beliefs in “successful” treatment. As is often the case where such a diagnostic dilemma and variation in treatment exists, this suggests that either all treatments have some success reflective in part of the self-limiting nature of the condition or none of the treatments are particularly successful. Groin pain in itself can be a very frustrating condition to treat supporting the difficulties with diagnosis and as a consequence the difficulties in tailoring treatment.


Epidemiology





  • The incidence of groin injuries appears to be growing in frequency and is now recognized as a significant contributor to time off the field in several professional sports, in particular in various football codes and ice hockey.



  • Athletes, particularly those involved in high level competition, can often play through minor symptoms and so the prevalence is likely to be much higher than previous reports of injuries causing time off the field.



Age





  • Groin injury occurs more common in athletes who have been competing at an elite level for a number of seasons.



  • They were uncommonly seen in rookies in a study of NFL footballers with 95% of players with this injury having played in the NFL for 5 years or longer.



  • Average age in the majority studies for patients presenting with this injury is in the late twenties.



Sex





  • Groin injury is almost exclusively reportedly as an injury of the male athletic population, most likely because of the sports it has been studied in such as NFL football, soccer, and ice hockey.



  • The statistics and reasons for the different incidence between males and females have not been specifically studied.



Sport





  • Certain sports, namely ice hockey and soccer, report the highest amount of groin injuries, with an incidence of 0.8 to 1.3 injuries per 1000 hours of athletic activity, and strains, accounting for up to 43% of all muscle strains in elite Finnish ice hockey players and 10% of all injuries in a study of elite Swedish Ice hockey players.



  • The incidence of groin strains in a single National Hockey League (NHL) team was 3.2 strains per 1000 player-game exposures.



  • Only limited information exists on acute groin injuries. The only study looking exclusively at acute groin injuries in soccer reports a groin injury incidence of 0.8 injuries per 1000 hours play. In male soccer a prospective study of the elite teams hip/groin injuries accounted for 12% to 16% of all injuries per season. The total injury incidence was 1.1/1000 hours with 3.5/1000 match hours and 0.6/1000 training hours. Adductor-related and iliopsoas-related groin injuries were the most common injuries and 15% of the injuries were re-injuries.



  • In the National Football League (NFL) (American football) the most common muscle-tendonous injuries related to the groin were rectus femoris strain and adductor strains.



Position





  • The effect of position seems to be far less important than the type of sport. In a review of NFL data, the problem appears to predominantly affect linesmen whereas most playing positions in soccer and ice hockey (the two most common sports for this injury) position has not been highlighted as playing such an important role. Recently, however, it has been shown that hip and groin injuries account for one third of the injuries in goalkeepers in soccer.



  • The incidence of hip and groin injuries is higher in goalkeepers than in field players. This highlights that sporting actions such as kicking, stretching out in an abnormal position or rapid change of direction may be of particular importance, and responsible for the development of these injuries.



Pathophysiology


The Pathophysiology of injuries to the groin region is complex and complicated. Anatomically it is a confluence of a number of structures, and a number of structures have been implicated as the “primary” source of groin pain with little supporting robust scientific evidence. The latest example of this is the finding of reduced range of motion and radiological signs of femoro-acetabular-impingement (FAI) in hips of athletes who also get adductor localized groin pain. There have however been no studies that show treating the hip problem makes a difference to the risk or recovery from groin problems in these athletes whereas the response to a well-structured rehabilitation regime has shown significant improvement in well-constructed studies.


Intrinsic Factors


The tendons of the rectus abdominis and the adductor longus effectively form a continuous structure, termed by some authors as the “common adductor-rectus abdominis origin” ( Figure 25-1 ). Biomechanically this acts as a dynamic stabilizer of the pubic symphysis such that any dysfunction of either tendon unit predisposes the other to failure as a result of increased load. Secondary loss or dysfunction of the stabilizers of the symphysis can lead to increased load on this joint as well and as a result symptoms and signs in the region can be distributed over a wide area. Injury to the attachment of the posterior wall of the inguinal canal as part of the anterior rectus sheath can result in hernia-like formation and symptoms as part of the spectrum of injuries in this region.




FIGURE 25-1


Schematic representation of the confluent but apposing muculotendinous units of the rectus abdominis and adductor longus muscles.

(Courtesy of Prof. Adam C. Zoga, Department of Radiology, Thomas Jefferson University, Philadelphia, PA.)


Injury to the structures around the groin is intrinsically related to repeated loading of this complex of muscles and the joints they support. It can be seen that specific muscles are activated during the different phases of kicking a football and the maximal activation of the adductors as the leg is reversed from a fully extended position approaching impact with the ball. This places this musculotendinous structure of the adductors at risk of injury. Musculotendinous structures of the adductors are at greatest risk when at their maximal length, which is also the part of the kicking phase (the initial swing phase) where there is peak adductor longus activation, predisposing this region to injury. Also, the specific action of skating on the ice and the necessity for rapid and often unplanned changes of direction, again especially stressing the adductors and the abdominals places repeated maximal loads on the groin region. It is possible that the nature of the walking gait as man has become bipedal also changes the muscle dynamic of the adductor region. Rather than going through phases of rapid stretch and forceful muscle activation, this muscle is seldom stressed in this way in regular walking so activities that require sports-specific movements such as kicking and skating could be seen as atypical for this muscle group ( Figure 25-2 ).




FIGURE 25-2


Timing of the swing phase.

(From Charnock BL, Lewis CL, Garrett WE Jr, Queen RM. Adductor longus mechanics during the maximal effort soccer kick. Sports Biomech 8(3):223-224, 2009.)


Extrinsic Factors


The unique nature of skating on ice including the rapid acceleration/deceleration and changing direction on skates clearly demonstrates how increasing forces can play a role in this injury. Similarly, injuries to the rectus abdominis insertion have been described in tennis players because of the unique repeated loading of this muscle in this sport. The role of the introduction of artificial turf into the frequency of groin-related injuries has been discussed with American Football injuries, but no good study has been able to correlate an increasing reported incidence of this injury with changes to the playing surface as a significant dependent variable.


Traumatic Factors


Acute muscle tear or strain: Injuries that are the result of a direct blow or rapid stretching/twisting movement can potentially injure a number of structures in the groin region. Characteristically, the patients describe planting and twisting or getting twisted or rapidly bringing the leg from a neutral to an abducted position. Once this region has been injured, it is often the case that repeated minor trauma can continue to aggravate the symptoms and cause ongoing recalcitrant pain, restriction and avoidance of provocative maneuvers whenever possible.


Classic Pathological Findings


Adductor/Abdominal Muscle-Tendinous Injury


Pain arising from adductor tendon damage can be very difficult to localize. The tendon of insertion of the rectus and origin of the adductor have been shown to be very close anatomically and their function is antagonistic in stabilizing the pelvis and the symphysis in a variety of activities. Pain in this region can therefore be classically referred into both areas as well as towards the symphysis and almost impossible to separate out. Such diagnoses fall under the classification of most tendon strains or chronic injuries and can be grouped as the treating physician prefers and finds useful. This can include clinical grading such as that described by Blazina ( Box 25-1 ) in association with the degree of damage defined by imaging studies. Less severe injuries may just have an awareness of pain aggravated by intense loading of the muscles concerned, more symptomatic examples may have pain or discomfort at rest that is initially eased by activity only to return and with increased intensity once the activity has ceased.



Box 25-1

Blazina Grading of Tendinopathy


















Grade 1 Pain after activity with no functional impairment
Grade 2 Pain at the beginning of activity, disappearing after warm up, reappearing after activity
Grade 3 Pain during and after activity with functional impairment
Grade 4 Complete tendon rupture



Muscular or tendinous injury in this region is far more common in males than females and so making the diagnosis in the female should always make the examiner check for other “pelvic”-related problems as a potential source. Relationship of the pain to the frequency or intensity of activity should allow the examiner to lean towards a tendon or muscle strain or tendinopathy. Aggravation of symptoms by palpation and resisted isometric testing of the affected muscle, either during adductor contraction or abdominal “crunch” type activity, brought on by repeated use or testing can help attribute the symptoms to either one or the other but often testing of both muscles can bring on the symptoms. Use of local anesthetic injection may help localize the pathology but in more severe examples, which have been going on for some time and chronicity, where the pain can be over a wide area and reference zone, makes localizing of the cause of the pain more difficult.


Iliopsoas Muscle-Tendinous Injury


The iliopsoas muscle can also be acutely strained or injured through repetitive overuse. This usually happens as a consequence of specific of repetitive forceful hip flexion during running, skating, jumping, or kicking. It can also be injured during an eccentric contraction, as when the thigh is suddenly forced into extension and the iliopsoas will try to decelerate the movement by an instantaneous eccentric muscle action. The overused iliopsoas tendon will sometimes appear with a spindle shape, near the insertion point on the trochanter minor, which can be visualized by ultrasound examination. Again the use of use of local anesthetic injection may also help localize the pathology from other structures, as iliopsoas symptoms can often coexist with other pathologies, such as adductor related injuries and intraarticular hip problems.


Clinical Presentation


History


These patients will often give a history of one precipitating event or action but may on more detailed questioning admit to having had some aching discomfort in the groin region before this. These minor symptoms are so common in the sports such as soccer and ice hockey that players almost accept it as the “norm.” It is only with sudden worsening of intensity to the point where performance begins to be affected do they bring it to the treating clinicians attention. Characteristically these patients have a central aching discomfort in the groin region on one side or the other, aggravated by activity and localizing tenderness to clinical examination made worse by bracing maneuvers or single leg stance loading. The pain will often linger long after exercise has finished and may create sleep disturbance and early morning symptoms. This pain is characteristically brought on by resisted adduction of the leg, typically worsened when performed in an abducted position.


Muscular or tendinous injury in this region is far more common in males than females and so making the diagnosis in the female should always make the examiner check for other “pelvic”-related problems as a potential source. Relationship of the pain to the frequency or intensity of activity should allow the examiner to lean towards a tendon or muscle strain or tendinopathy. Relationship of the pain to bracing or “crunching” activities but not so obvious with resisted adduction should make the clinician consider a hernia or “sports hernia” as part of the differential diagnosis.


A number of risk factors ( Table 25-1 ) have been identified and should be looked for in the history and examination of these patients to alert the examiner to possible cause(s) of the pain. Previous injury, increasing age, weak adductors, and low levels of off-season sports-specific activities have been shown to be significant risk factors for sustaining a groin injury. In Australian Rules Football (AFL) young players reporting a previous hip or groin injury at the draft medical assessment demonstrated a rate of hip/groin injury in the AFL more than six times higher than players without a pre-AFL hip or groin injury history.



Table 25-1

Multivariate Analysis of Potential Risk Factors for Adductor Injury
































































Risk Factors Adjusted OR 95% CI p Value
Player-Dependent Factors
Age 1.10 0.74–1.63 .65
Counter-movement jump test 1.01 0.89–1.14 .92
Leg-Dependent Factors
Previous acute groin injury (yes/no) 2.60 1.10–6.11 .03
GrOS total score 1.04 0.78–1.41 .77
Clinical Examination
External rotation in the hip joint (painful or not) 2.90 0.55–15.2 .21
Functional testing of rectal abdominal muscles (painful or not) 0.89 0.28–2.79 .84
Strength of adductor muscles (weak or not weak) 4.28 1.31–14.0 .02
Strength of iliopsoas muscles (weak or not weak) 2.23 0.39–12.7 .36

From Engebretsen AE, Myklebust G, Holme E, et al: Intrinsic risk factors for groin injuries among male soccer players: A prospective cohort study. Am J Sports Med 38:2051–2057, 2010.


Table 25-2 highlights the range of clinical entities that can contribute alone or in combination when taking a history and examining these types of patients.



Table 25-2

Primary, Secondary, and Tertiary Clinical Entities in Soccer Players with Groin Pain















































































Clinical Entity Primary, n (%) Secondary, n (%) Tertiary, n (%)
Adductor-related pain 94 (686.) 4 (2.9)
Iliopsoas-related pain 35 (25.5) 31 (22.6) 6 (4.4)
Sports hernia 2 (1.5) 1 (0.7)
Snapping Iliopsoas 1 (0.7)
Pelvic floor-related pain 1 (0.7)
Rectus abdominus-related pain 1 (0.7) 11 (8) 3 (2.2)
Sacrotuberal ligament pain 1 (0.7) 4 (2.9) 1 (0.7)
Sacroiliac joint dysfunction 1 (0.7)
Hip arthrosis 1 (0.7) 1 (0.7)
Pain of thorocolumbar origin 1 (0.7)
Hernia 1 (0.7)
Piriformis-related pain 1 (0.7) 1 (0.7)
Stress fracture 1 (0.7)
Total 137 (100) 52 (38) 11 (8)

From Hölmich P. Long-standing groin pain in sportspeople falls into three primary patterns, a “clinical entity” approach: a prospective study of 207 patients. Br J Sports Med 2007 Apr;41(4):247-52; discussion 252, 2007.


Physical Examination


Examination of these patients must be comprehensive and cover a large number of potential entities that can contribute to the problem and as can be seen from the previous table, more than one entity can appear to be contributing to the symptoms.


Assessment of gait and leg length is mandatory, as well as signs of bruising for evidence of acute muscle/tendon injury which is usually an obvious sign (see Figure 25-3 ). In less obvious cases, local tenderness at the origin of the adductor tendons is helpful but localizing tenderness for other of the differential diagnoses is difficult to elicit and the pain can often be in a broad region making localizing the source difficult. Any swellings or signs of true hernias should be checked for and recurrence of symptoms more proximally in the region, with abdominal “crunching” testing may be more indicative of a “sports hernia” as a potential source of the pain. This, however, is usually a diagnosis of exclusion, often after surgical treatment of other conditions has failed ( Figure 25-3 ).




FIGURE 25-3


Bruising associated with acute adductor longus rupture injury.


Hip range of motion is often reduced and has led to the theory, unsupported by scientific evidence so far, that hip impingement may be a contributing factor.


Pain on palpation and aggravation of symptoms by resisted isometric testing of the affected muscle, either during adductor contraction or abdominal “crunch” type activity, brought on by repeated use or resistance testing can help attribute the symptoms to either one or the other but often testing of both the adductors and the abdominal rectus can bring on the symptoms. Use of local anesthetic injection may help localize the pathology but in more severe examples, which have been going on for some time and chronicity, the pain can be over a wide area and reference zone, making localizing of the cause of the pain more difficult.


Quantifying adductor strength will often make obvious more subtle differences in adductor related problems and highlight the need for a strengthening program as an essential part of overall treatment. Use of a hand-held dynamometer to do this has been shown to be accurate and reproducible and is most sensitive when performed at the ankle with the leg in 0° of hip flexion ( Figure 25-4 ).




FIGURE 25-4


Use of a hand-held dynamometer to measure adductor strength.

(From Thorborg et al. Clinical assessment of hip muscle strength is reliable. SJMSS 20:493-501, 2010, with permission.)


One of the challenges with these patients is that the examination findings may be almost entirely normal or very difficult to isolate a single cause for the patient’s symptoms. Use of imaging to support the clinical suspicions and exclude such pathologies as stress fractures can be diagnostic. At times “abnormal findings” on imaging will not correlate with your clinical findings and imaging studies should not replace clinical assessment and examination findings.


Imaging





  • X-rays of the hip and pelvis are mandatory and a loaded view of the pubic symphysis (the flamingo view) may show evidence of subtle symphyseal instability. Views to look for FAI are considered mandatory for some clinicians and certainly indicated where hip range of motion is markedly reduced.



  • CT scanning can further investigate associated hip abnormalities, early osteoarthritis of the hip or changes in the symphysis pubis. Stress fractures of the femoral neck or pubic ramus may also be better seen on CT.



  • Ultrasound is useful in acute injuries in particular and if any swellings are visible at examination.



  • MRI scanning is usually an inevitable investigation in these patients and many will bring such imaging with them that has been interpreted in a variety of ways by a variety of physicians they have seen previously. Positive findings on MRI scan that correlate with clinical findings are definitely supportive information for the clinician and patient, however, abnormal reported findings that do not have a close clinical correlate should be treated with caution. Features such as edema in the parasymphyseal region of the pubic symphysis may warrant reexamination of the patient, taking these findings into consideration. The diffuse nature of the pain on presentation can make localization of the pathology and diagnosis difficult, so having a structured examination system and correlating findings with MRI changes is likely to produce the highest clinical accuracy.



  • A bone scan can be useful in isolating problems to the symphysis or revealing a stress fracture around the groin such as pubic rami or femoral neck. A CT scan to show the detail of the bony injury is then indicated ( Table 25-3 and Box 25-2 ).



    Table 25-3

    Checklist for MRI Evaluation of Adductor Injury





































    Muscle and Tendon Sign/Symptom
    Adductor longus – tendinous (superficial) and muscular (deep) origin on anterior pubic bone (bone without perisoteum)
    – avulsion usually associated with bone fragment
    Adductor brevis – muscular origin posterior to adductus longus
    Adductor tendon injury – myotendinous injury—proximal (or distal)
    Pectineus – origin lateral public symphysis and superior pubic crest
    Obturator externus – origin postero-lateral pubic systems
    Gracilis – origin anteroinferior pubic symphysis and superior pubic arch
    Grading of Injury
    Adductor muscle strain
    Acute – increased T2 signal
    Chronic – Hypertrophic
    – Atrophic


    Box 25-2

    MRI and Radiology of Groin Injury Associated Pathologies


    Rectus Abdominis





    • Attachment to superior pubic ramus



    • Medial and lateral heads



    Rectus Abdominis/Adductor Aponeurosis





    • Attachment to antero-inferior pubic bone



    Rectus Abdominis/Adductor Aponeurosis Injury





    • Ipsilateral rectus abdominis distal detachment + adductor aponeurosis partial or complete detachment



    • Unilateral rectus abdominis atrophy



    • Unilateral or bilateral adductor aponeurosis injury



    Rectus Abdominis/Adductor Aponeurosis Plate Disruption





    • Secondary Cleft Sign



    • Antero-inferior pubic bone curvilinear increased T2 signal



    Symphysis Pubis


    Bone marrow edema


    Location:




    • Superior = rectus abdominis



    • Antero-inferior = RA/AA



    • Lateral = pectineus



    • Postero-lateral = obturator externus



    Unilateral or bilateral


    Degenerative change




    • Subchondral cystic change



    • Subchondral sclerosis



    • Erosions



    Acquired Inguinal Wall Deficiency


    Frequent coexistent adductor tendon injury


    Anterior inguinal ring insufficiency


    Tear medial aspect external oblique, resulting in patulous external inguinal ring


    Proposed that pain is caused by entrapment of cutaneous branches of the ilioinguinal nerve and genital branch of genitofemoral nerve


    Clinical diagnosis


    Rare to have findings on MR or US


    MR—may see hyperintensity of external inguinal ring


    Posterior Inguinal Wall Insufficiency


    Conjoint tendon or transversalis fascia attachment tear or weakness


    Use of imaging debated for diagnosis


    US Posterior inguinal wall bulging—not sensitive or specific sign, as can be present in asymptomatic population


    MR dynamic imaging


    Asymmetrical focal protrusion of the posterior inguinal wall without a hernia




Differential Diagnosis





  • Hip joint pathology



  • Stress fractures (inferior rami and femoral neck)



  • Internal or external snapping hip



  • Avulsion fractures (sartorius and rectus femoris)



  • Bursitis (traumatic or inflammatory)



  • Nerve entrapment (obturator, ilioinguinal, and genitofemoral nerve branches)



  • Gynecological or urological disorders



  • Neoplasms (osteosarcomas, chondrosarcomas, other tumors)



Treatment


Nonoperative Management


Groin injuries can be difficult to treat and are often ignored by athletes and trainers, thus developing into a chronic stage before being recognized as affecting a player’s or patient’s performance and function. The primary treatment of choice for both acute and longstanding conditions in musculoskeletal groin injuries is an active treatment approach consisting of mobilization and exercise. Treatment is based on a systematic examination and an exact identification of the painful structure(s). This examination is based upon thorough history-taking and identification of the specific injury by palpation and isometric contractions where specific structures are isolated and specific pain responses are elicited. Diagnostic imaging can be relevant to exclude differential diagnoses, and in determining severe structural injury, such as complete and partial ruptures, but it is not advisable to be to obsessed with discrete imaging findings in isolation, as the exact understanding of such findings is not established. Therefore, treatments should primarily be based on clinical findings and their related dysfunctions, instead.


Guidelines for Choosing Among Nonoperative Treatments


The use of adjuvant modalities such as cortisone and more recently platelet enriched plasma injections has little support with scientific study and should be used with caution. Use of cortisone injections carries the same issues as other tendon injuries treated this way. It has a role in allowing short-term improvement but often the symptoms recur unless the “window” of reduced symptoms is used with rigorous rehabilitation to restore strength. An intraarticular anesthetic injection under radiological guidance can be helpful in determining the role any intraarticular hip pathology may be playing in the source of the patient’s symptoms. Similarly, injection into the pubic symphysis can provide relief of symptoms where this joint is the main source of pain but repeated injections can lead to significant joint damage and increased symptoms.


The likelihood of a sustained improvement from any passive adjuvant modality is directly related to the regaining of strength and function.




  • Acute muscle-tendinous groin injuries




    • The acute treatment includes the Rest, Ice, Compression and Elevation protocol, then introducing gentle mobilization. Increasing range of motion can be commenced after the acute phase. Progression to isometric and then increasing resistance exercises can follow in a graduated regime. Sports-specific drills can be progressively commenced when isometric and eccentric strength is nearly normalized. Return to sport (competition) can be commenced as recovery improves and normal weekly training loads needs to be tolerated before return to competition is advisable.




  • Longstanding muscle-tendinous groin injury




    • For adductor-related groin pain, controlled static and dynamic exercises with focus on neuromuscular activation of the adductors, followed by increasing load and special emphasis on lengthening contractions, as well as challenging balance and co-ordination exercises has been shown to be very effective. These protocols are outlined in more detail in subsequent chapters




  • Iliopsoas-related groin pain/injury




    • The same principles are applied as with the adductor injuries. Systematic strengthening—including isometric, concentric and eccentric contractions—combined with a series of pelvic stabilization and balance exercises are included in the treatment of the longstanding iliopsoas related groin pain. Stretching, massage, and trigger point stimulation for symptomatic relief might also be helpful, but is not the primary treatment. These injuries will have a similar favorable response as highlighted in the adductor related rehabilitation guidelines to a period of initial rest in acute injuries and then a structured strengthening program to allow full functional recovery and reduce the risk of re-injury.




  • Rectus abdominis related groin discomfort




    • Injuries that appear to involve the rectus insertion have restoration of strength after control of pain related symptoms as the ideal goal of treatment. Use of specific rectus abdominis strengthening exercises is an integral part of such a program.




  • Sports hernia




    • As the sportsman’s hernia is an incipient hernia, rehabilitation should always be initiated first. A training program focusing on strength and coordination of the involved muscles provides an opportunity for the abdominal wall-lesion to heal. Using some of the exercises from the adductor-related program is of relevance as abdominal related injuries are often found in combination with adductor related injuries.




  • Stress fractures




    • A period of rest for 6 weeks and reintroduction of activity over a graduated 6-week period is a standard guideline for most stress fractures in the “adductor region” including compression sided fractures of the femoral neck and fractures of the pubic symphysis. Addressing all the contributing factors in these athletes including the diet, menstrual cycle irregularities and volume of exercise in the female athlete play an important role in this. Investigations of markers of bone metabolism including vitamin D levels are mandatory.




Preventing Groin Injury and Reinjury


Sport-specific prevention strategies to reduce the risk of groin injury in sport should include a specific focus on athletes with previous injury, and early identification of hip strength deficits. Total workload should also be specifically addressed and reduced in periods where athletes show clinical signs of hip and groin pain. In the off-season it is important for athletes to continue sports-specific activities and include strength-training exercises to stimulate muscle-tendinous health and repair.


Because previous groin injury is one of the best established risk factors, athletes displaying this risk-profile may benefit from specific attention by incorporating a specific exercise program focusing on the structures involved in their previous injury, and other related deficits, such as decreased eccentric strength, and possible lack of pelvic stability and coordination. The strength ratio between adductors and abductors seems to be important for injury prevention, as preseason strength training of the adductor muscles in ice hockey players ensuring an adductor/abductor strength ratio of 80% or more could decrease the number of adductor related groin injuries. A randomized treatment study including specific training of the adductor muscles (isometric, concentric, and eccentric), as well as exercises for the muscles related to the pelvis and torso, including 1022 male soccer players found that groin injuries were 31% less in the intervention group, compared with the control group. This difference was, however, not statistically significant, as the statistical power was too low to detect such a difference. As a possible groin injury reduction of 31% in a cohort of soccer players seems to be clinically meaningful, this program may be worthwhile to introduce in soccer teams where groin injuries constitute a significant problem.


Surgical Indications


The surgical management of groin injury depends primarily on accurately identifying the source of the pain. It cannot be emphasized too frequently that detailed clinical examination is the mainstay of making the correct diagnosis and supported by imaging studies. A subgroup of these patients have potentially multiple contributing pathologies and whether taking care of what seems the primary pathology will allow the others to recover or dealing with all apparent recalcitrant causes of pain and restriction is much argued about and seldom agreed on. For those patients with conditions identified that can be helped with nonoperative strategies outlined above, particularly adductor, rectus and psoas related problems, all patients should have undergone a supervised, rigorous, and appropriate rehabilitation schedule, as outlined in detail in following chapters, before surgery should be considered. Similarly the importance of a well-supervised, graduated, detailed progression of strengthening and proprioceptive retraining cannot be under emphasized as the key to a successful outcome. All treatment strategies, be they surgical or nonsurgical have the alleviation of pain to allow the restoration of strength as the primary goal.


Aspects of Clinical Decision Making When Surgery Is Indicated





  • Direct or indirect hernias




    • Thorough clinical examination will usually reveal a true direct or indirect hernia as the main contributing factor in a patient’s symptoms. Referral for surgical treatment to an experienced laparoscopic surgeon is indicated and this condition can usually be managed around the competitive requirements of the athlete.




  • Fractures




    • Stress fractures on the tension (superior) side of the femoral neck require surgical management with compression fixation but are rare. Recalcitrant stress fractures of the femoral neck compression side or pubic ramus may require fixation usually with compression and rarely with bone grafting if sclerotic fracture ends are obvious on imaging. Again the key to identifying these diagnoses is an accurate history and physical examination and a screening bone scan if there is high index of suspicion but no obvious fracture on routine radiographs is probably the most sensitive and reliable imaging study.




  • Acute adductor tendon injury




    • As noted previously, repair of adductor tendon injuries are probably not indicated and it is often a difficult tendon to get a robust repair. Protecting your repair is also difficult as only sustained bed rest is likely to remove tension on the repair while it heals. Unless avulsed with a surgically repairable piece of bone, surgery to repair adductor tears has been associated with significantly longer return to sport and greater risk of complications. There has been no evidence of greater strength loss without repair and as long as the structured program outlined in this section is followed, patients who have had tears treated nonoperatively can achieve a similar outcome.




  • Adductor tendinopathy




    • A small subgroup of patients who have had adductor tendon pathology identified as their primary source of groin pain on history, pertinent physical exami­nation findings and supportive imaging studies will continue to have restrictive symptoms despite attempting an appropriate rehabilitation and strengthening program. Surgical intervention in this group of patients provides a frequently rewarding relief of symptoms to allow them to successfully complete a rehabilitation program and regain strength and function. Temporary relief of symptoms with local anesthetic or cortisone, possibly injected under ultrasound control, is a helpful diagnostic adjuvant to support surgical treatment for both the clinician and the patient. It is relatively easily performed under direct vision and having the patient exercise immediately after use of any local and measuring improvement in a documented weakness in adductor strength is very helpful clinical information. Surgical release of the tendinous origin under direct visualization and possibly decompression of the obturator nerve have been associated with significant benefit in patients but long-term follow-up or randomized studies are not available in the literature.




Outcome Evaluation


Reliable, valid, and responsive outcome measures are important in the evaluation of patients with groin injury. The Copenhagen Hip And Groin Outcome Score (HAGOS) is developed specifically for younger patients with hip and groin pain. HAGOS is a patient-reported outcome measure employing five-item Likert scales. HAGOS consists of six subscales: pain, other Symptoms, physical function in daily living (ADL), Function in sport and recreation (Sport/Rec), participation in physical activities (PA), and hip-related quality of life (QOL). HAGOS can be used to assess groups and to monitor individuals, it is patient-administered and the format is user-friendly, and takes about 10 minutes to fill out. HAGOS is self-explanatory and can be administered in the waiting room or used as a mailed survey. HAGOS was found reliable, valid, and responsive in younger patients with hip and groin pain.


Isometric and eccentric strength is also important to evaluate in patients with groin injury. Reliable measures with hand-held dynamometry exist for hip adductors and hip flexors and can be used in the evaluation of when muscle strength is normalized in this region in the clinical setting. Pain during palpation and isometric maximal contraction are also good indicators of improvement in function. Different sports-specific activities, and range of motion measures, are other relevant measures that can be obtained and used for prospective evaluation of the recovery process of these injuries.


Evidence


  • Emery CA, Meeuwisse WH: Risk factors for groin injuries in hockey. Med Sci Sports Exerc 2001; 33: pp. 1423-1433.
  • This was a cohort study aimed at determining the level of off-season sport-specific activity, peak isometric adductor torque, and hip abduction flexibility that are predictive of groin or abdominal strain injury in the National Hockey League (NHL). The subjects were 1292 NHL players assessed during training camp. Estimated relative risks of injury were reported using six different exposures. Players who reported less than 18 sessions sport-specific training in the off-season were at greater than three times the risk of injury than those who did not (relative risk [RR]; 3.38 95% confidence interval [CI], 1.45 to 7.92). Players who reported previous history of this injury were at more than two times the risk of injury than those who did not (RR, 2.88; 95% CI, 1.33 to 6.26). Veterans were at greater than five times the risk of injury than rookies (RR, 5.69; 95% CI, 2.05 to 15.85). Peak isometric adductor torque, total abduction flexibility, and skate blade hollow measurement were not predictive of injury. Low levels of off-season sport-specific training and previous injury were identified as risks for groin injury at an elite level of hockey. (Level III evidence)
  • Engebretsen AE, Myklebust G, Holme E, et. al.: Intrinsic risk factors for groin injuries among male soccer players: A prospective cohort study. Am J Sports Med 2010; 38: pp. 2051-2057.
  • This was a prospective cohort study conducted to determine if risk factors for groin injuries among male soccer players could be identified. A total of 508 players representing 31 amateur teams were tested during the 2004 preseason for potential risk factors for groin injury through a questionnaire on previous injury and function score and a clinical examination of the groin. The total incidence of groin injuries was 0.6 injuries per 1000 playing hours, 0.3 injuries per 1000 training hours, and 1.8 injuries per 1000 match hours. Previous acute groin and weak adductor muscles as determined clinically were significantly associated with increased risk of groin injuries. A multivariate analysis based only on acute time-loss injuries revealed the 40-m sprint test and functional testing of the rectal abdominal muscles as significant risk factors. (Level III evidence)
  • Hölmich P, Larsen K, Krogsgaard K, et. al.: Exercise program for prevention of groin pain in football players: a cluster-randomized trial. Scand J Med Sci Sports 2010; 20: pp. 814-821.
  • A cluster-randomized trial including 55 football clubs representing 1211 players was performed. The clubs were randomized to an exercise program aimed at preventing groin injuries (n = 27) or to a control group training as usual (n = 28). The intervention program consisted of six exercises including strengthening (concentric and eccentric), coordination, and core stability exercises for the muscles related to the pelvis. Physiotherapists assigned to each club registered all groin injuries. Twenty-two clubs in each group completed the study, represented by 977 players. There was no significant effect of the intervention (HR = 0.69, 95% CI 0.40 to 1.19). The risk of a groin injury was reduced by 31%, but this reduction was not significant. (Level I evidence)
  • Hölmich P, Uhrskou P, Ulnits L, et. al.: Effectiveness of active physical training as treatment for longstanding adductor-related groin pain in athletes: randomised trial. Lancet 1999; 353: pp. 439-443.
  • Sixty-eight athletes with long-standing (median 40 weeks) adductor-related groin pain—after examination according to a standardized protocol—were randomly assigned to active treatment (AT) or passive treatment (PT). The treatment period was 8 to 12 weeks. Four months after the end of treatment a standardized examination was done and 23 patients in the AT group and four in the PT group returned to sports without groin pain (odds ratio, multiple-logistic-regression analysis, 12.7 [95% CI 3.4 to 47.2]). AT with a program aimed at improving strength and coordination of the muscles acting on the pelvis, in particular the adductor muscles, is very effective in the treatment of athletes with long-standing adductor-related groin pain. (Level I evidence)
  • Thorborg K, Petersen J, Magnusson SP, et. al.: Clinical assessment of hip strength using a hand-held dynamometer is reliable. Scand J Med Sci Sports 2010; 20: pp. 493-501.
  • This was a normal subject based case control study that examined the absolute test-retest measurement variation concerning standardized strength assessments of hip abduction (ABD), adduction (ADD), external rotation (ER), internal rotation (IR), flexion (FLEX), and extension (EXT) using a hand-held dynamometer. Nine subjects (five males, four females), physically active for at least 2.5 hours a week, were included. Twelve standardized isometric strength tests were performed twice with a 1-week interval in between by the same examiner. When the maximum value of four measurements was used, test-retest measurement variation was below 10% in 11 of the 12 individual hip strength tests and below 5% in 5 of the 12 tests. Standardized strength assessment procedures of hip ABD, ER, IR, FLEX, with test-retest measurement variation below 5%, hip ADD below 6% and hip EXT below 8%, make it possible to determine even small changes in hip strength at the individual level using this method. (Level III evidence)
  • Tyler TF, Nicholas SJ, Campbell RJ, et. al.: The effectiveness of a preseason exercise program to prevent adductor muscle strains in professional ice hockey players. Am J Sports Med 2002; 30: pp. 680-683.
  • This was a prospective risk factor prevention study in 33 of 58 players from the same National Hockey League team who were identified as “at risk” on the basis of preseason hip adductor strength and participated in an intervention program. The program consisted of 6 weeks of exercises aimed at functional strengthening of the adductor muscles. There were 3 adductor strains in the 2 seasons subsequent to the intervention, compared with 11 in the previous 2 seasons (0.71 vs 3.2 per 1000 player-game exposures). A therapeutic intervention of strengthening the adductor muscle group appeared to be an effective method for preventing adductor strains in professional ice hockey players. (Level II evidence)
  • Zoga AC, Kavanagh EC, Omar IM, et. al.: Athletic pubalgia and the “sports hernia”: MR imaging findings. Radiology 2008; 247: pp. 797-807.
  • This study was a retrospective review of MR imaging studies in 141 patients who had been referred because of groin pain were reviewed for findings including hernia, pubic bone marrow edema, secondary cleft sign, and rectus abdominis and adductor tendon injury. MR imaging findings were compared with surgical findings for 102 patients, physical examination findings for all 141 patients, and MR imaging findings in an asymptomatic control group of 25 men of similar age. Compared with surgery, MR imaging had a sensitivity and specificity, respectively, of 68% and 100% for rectus abdominis tendon injury and 86% and 89% for adductor tendon injury. Injury in each of these structures was significantly more common in the patient group than in the control group (p < .001). (Level IV evidence)

  • Multiple-Choice Questions




    • QUESTION 1.

      What epidemiological risk factor has not been shown to have an association with increased risk of adductor related groin injury?



      • A.

        Sex


      • B.

        Type of sport played


      • C.

        Playing at an elite level for greater than 12 months


      • D.

        Previous adductor injury



    • QUESTION 2.

      During which phase of kicking are the musculotendinous structures of the adductors at their greatest risk?



      • A.

        Plant


      • B.

        Swing


      • C.

        Contact


      • D.

        Follow through



    • QUESTION 3.

      What is the greatest associated risk factor on history and examination for sustaining a future groin injury?



      • A.

        Adductor strength


      • B.

        Age


      • C.

        Iliopsoas strength


      • D.

        Previous injury



    • QUESTION 4.

      What is the most relevant clinical indication of improvement from a muscle-tendinous groin injury with a structured rehabilitation program?



      • A.

        Pain-free single leg hop repetitions


      • B.

        Improved tolerance and duration of adductor stretching


      • C.

        Pain-free return to running


      • D.

        Pain-free maximal contraction and regains of muscle strength




    Answer Key







    Nonoperative Rehabilitation of Longstanding Groin Injury



    Kristian Thorborg, PT, MSportsphty, PhD
    Bruce Charles Twaddle, BHB, MBChB, FRACS




    • The tendon of the insertion of the abdominals and origin of the adductors often can be involved in overuse and longstanding conditions that include groin pain as the cardinal symptom.



    • Characteristically this pain is aggravated by loading of the musculotendinous tissues with some pain or discomfort at rest that may be initially eased by activity only to return and with increased intensity once the activity is increased or after the activity has ceased.



    • The iliopsoas muscle can also be injured through repetitive overuse. The overused iliopsoas tendon will sometimes appear with a spindle shape on ultrasound examination, near the insertion point on the lesser trochanter minor.



    • One high-quality clinical randomized trial of longstanding adductor-related groin pain has described a specific exercise program found to be highly effective in the treatment of this condition. The exercise program consists of two phases:




      • The first phase is a period of 2 weeks of careful static and dynamic exercises to teach the patient to reactivate the adductor muscles. In most cases the athlete with adductor-related groin pain has difficulties activating these muscles, probably as a result of pain and disuse.



      • In the second phase, the exercises are gradually more demanding; heavier resistance training as well as challenging balance and co-ordination exercises are added.




    • Nonoperative treatment of longstanding groin injury consists of active exercises performed at least three times a week for 8 to 12 weeks. This regimen can be done alone or in a group of two to four patients exercising according to the instructions and supervision of a physiotherapist. The duration of each individual training session is about 90 minutes. Patients with longstanding groin injury are told to do the exercises from module I on the days in between the treatment days.



    • Patients do not usually receive any other treatment for the groin pain before the final follow-up. No athletic activity is allowed during the treatment period. Patients are allowed to ride a bicycle or swim if it does not cause any pain.



    • The adductor exercise program is performed three times a week and the exercises from module I are done on the days in between the treatment days. The total length of the exercise-training period is between 8 and 12 weeks. Sports activities are not allowed in the treatment period. Riding a bicycle is allowed if it does not cause any pain.



    • After 6 weeks, running is allowed as long as it does not provoke any groin pain.



    • The exercise rehabilitation program is stopped when neither the exercise program nor the jogging causes any pain. The athlete is then allowed to increasingly progress to demanding sports-specific training towards final sports participation.



    Exercise Treatment for Athletes With Longstanding Adductor-Related Groin Pain


    Phase I : Muscle Activation (weeks 0 to 2)



    Apr 5, 2019 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Groin Injuries
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