MR imaging of rectus femoris origin injuries

Quadriceps injuries

Injuries to the quadriceps muscle group are common in athletes performing high-speed running and kicking sports. The complex anatomy of the rectus femoris puts it at greatest risk of injury. There is variability in prognosis in the literature, with reinjury rates as high as 67% in the severe graded proximal tear. Studies have highlighted that athletes can reinjure after nonoperative management, and some benefit may be derived from surgical repair to restore function and return to sport (RTS). This injury is potentially career-threatening in the elite-level athlete, and we aim to highlight the key recent literature on interventions to restore strength and function to allow early RTS while reducing the risk of injury recurrence. This article reviews the optimal diagnostic strategies and classification of quadriceps injuries. We highlight the unique anatomy of each injury on MRI and the outcomes of both nonoperative and operative treatment, providing an evidence-based management framework for athletes.

Measuring direct and indirect tendon parameters to characterize the proximal tendinous complex of the rectus femoris in football and futsal players

Objective: To present unprecedented radiological parameters that characterize the angle between the direct and indirect tendons of the proximal rectus femoris (RF) and its inclinations and to evaluate the population variability according to demographic variables. Materials and methods: From September 2019 to July 2021, using MRI multiplanar reconstructions of the proximal thigh/hip, two blinded radiologists measured the direct and indirect tendon angle and the inclination of each tendon in different planes. The intra- and inter-observer agreements were assessed with Bland-Altman analysis and intraclass correlation coefficient (ICC). The correlations between radiological parameters and demographic variables were evaluated using linear regression, Student's t-test, and analysis of variance. Results: We performed 112 thigh/hip MRI scans on 91 football players of different age, gender, and disciplines (football and futsal). For observer 1 (the reference), the mean direct and indirect tendon angle was 56.74° ± 9.37, the mean indirect tendon slope was -7.90° ± 7.49, and the mean direct tendon slope was 22.16° ± 5.88. The three measurements showed inter- and intra-observer agreement (mean differences ∼0). No correlation was observed between age and the parameters. Likewise, no statistically significant differences were found for gender, dominant limb, examined limb, and sport. Conclusion: There is an inter- and intra-observer agreement in the measurements of the direct and indirect tendon angle and the inclination of each tendon. There is population variability in the proximal tendinous complex unrelated to demographic factors. These results allow further detection of morphological patterns that represent a risk factor for lesions in the RF in professional football and futsal players and other sports.

US and MRI of Pelvic Tendon Anatomy and Pathologic Conditions

The bony pelvis serves as the attachment site for a large number of powerful muscles and tendons that drive lower extremity movement. Organizing the pelvic tendons into groups that share a common function and anatomic location helps the radiologist systematically evaluate these structures for injury, which can be caused by repetitive stress, acute trauma, or failure of degenerated tissues. Tears of the anteromedial adductors around the pubic symphysis and anterior flexors traversing anterior to the hip principally affect younger male athletes. Tears of the lateral abductors and posterior extensors are more common in older individuals with senescent tendinosis. The deep external rotators are protected and rarely injured, although they can be impinged. Imaging of the pelvic tendons relies primarily on US and MRI; both provide high spatial and contrast resolution for soft tissues. US offers affordable point-of-care service and dynamic assessment, while MRI allows simultaneous osseous and articular evaluation and is less operator dependent. While the imaging findings of pelvic tendon injury mirror those at appendicular body sites, radiologists may be less familiar with tendon anatomy and pathologic conditions at the pelvis. The authors review pertinent anatomy and imaging considerations and illustrate common injuries affecting the pelvic tendons. Online supplemental material is available for this article. ^©RSNA, 2022.

The capsular head of the proximal rectus femoris muscle: a review of the imaging anatomy of proximal muscle injury in professional athletes – early experience

The detailed anatomy of the rectus femoris and corresponding injury appearances were first described in 1995. Since then, there has been little published to change our understanding of this complex anatomical area. More recent anatomical dissection work in 2004 and 2006 alluded to the presence of an altered configuration of the proximal tendon anatomy. Whilst widely accepted that the proximal rectus femoris muscle has two distinct tendon slips, the authors in 2006 described a third separate tendon slip arising from the anterior femoral capsule and this has been widely termed the ‘capsular head’. We provide evidence that imaging features corroborate this revised anatomical concept. Whilst the clinical relevance of these findings is yet to be established, it remains important that our understanding of the radiological anatomy in this area advances with the forward growth of imaging clarity. In this review, we revisit anatomical concepts and present atypical injury cases that may be explained by the presence of a separate capsular head.

Association Between Injury Mechanisms and Magnetic Resonance Imaging Findings in Rectus Femoris Injuries in 105 Professional Football Players

OBJECTIVE

To describe the injury mechanism and its association with magnetic resonance imaging (MRI) injury findings in acute rectus femoris injuries.

DESIGN

Combined retrospective and prospective descriptive injury study. Retrospective cohort from January 2010 to October 2013 and prospective cohort from October 2013 to January 2019.

SETTING

Specialized sports medicine hospital.

PARTICIPANTS

Male professional football players older than 18 years playing in a national football league, referred for injury assessment within 7 days after an acute rectus femoris injury, with a positive finding on MRI.

INDEPENDENT VARIABLES

Rectus femoris muscle injury MRI findings in relation to injury mechanism in male football players.

MAIN OUTCOME MEASURES

Rectus femoris injury mechanism (kicking, sprinting, and others), MRI injury location, and grade.

RESULTS

There were 105 injuries in total, with 60 (57.1%) and 45 (42.8%) injuries from the retrospective and prospective cohorts, respectively. Kicking was the injury mechanism in 57 (54.3%) of all acute rectus femoris injuries, sprinting represented 32 (30.4%), and 16 (15.2%) were classified as others. There were 20 (19.05%) free tendon, 67 (63.8%) myotendinous junction and/or intramuscular tendon, and 18 (17.1%) peripheral myofascial located injuries. All free tendon injuries were related to kicking and graded as a complete tear of at least one of the tendons in 15/20 (75.0%) cases.

CONCLUSIONS

Kicking seems to be an important mechanism related to complete ruptures and injuries occurring at the proximal free tendon. Sprinting was the other most common mechanism but was never associated with injury to the proximal free tendon.

Soccer players show the highest seasonal groin pain prevalence and the longest time loss from sport among 500 athletes from major team sports

PURPOSE

Groin pain is a widely recognized medical issue among athletes. Groin pain can affect both player and team performance and sometimes can be a career-ending injury. The aim of this study was to assess seasonal groin pain prevalence and the average seasonal time loss from sport for each injury in different team sport athletes. The hip and groin functionality at the beginning of the following season was also investigated.

METHODS

A cross-sectional study was undertaken on 600 team sport athletes (soccer, futsal, basketball, volleyball, and water polo players). The seasonal prevalence of groin pain, level of competition (professional and non-professional), time loss, and concomitant injuries in addition to groin pain were reported and analyzed. The Copenhagen Hip and Groin Outcome Score (HAGOS) was used to assess hip and groin pain and function related to sport and activity.

RESULTS

Among the 506 (84%) players included, 123 players (24.3%) reported groin pain. Overall, soccer players reported the highest groin pain prevalence (32.5%) followed by futsal (25.5%), basketball (25.2%), water polo (17.6%) and volleyball players (13.6%). Professional soccer, futsal and basketball athletes showed higher groin pain prevalence in comparison with non-professional athletes (p = 0.02, p = 0.005 and p = 0.004, respectively). The mean time loss from sport due to groin pain was 60.3 ± 66 days in soccer, 41.1 ± 16.6 days in futsal, 31.5 ± 18 days in water polo, 37.2 ± 14.2 days in basketball and 50.8 ± 24.6 days in volleyball. Significantly lower HAGOS values were found in athletes with groin pain for all sports evaluated compared to athletes with no groin pain history (p =  0.0001). Longer time loss from sport was correlated with lower HAGOS values in soccer (p = 0.002) and futsal (p = 0.002) players with groin pain. Concomitant injuries were correlated with lower HAGOS values in water polo players (p = 0.03).

CONCLUSIONS

Seasonal groin pain occurs in as many as one in four team sport athletes. Soccer players show the highest groin pain prevalence and the longest time loss from sport. Professional athletes report higher prevalence of groin pain in comparison with non-professional athletes. HAGOS appears to be a valid outcome instrument to measure groin pain, correlating with both time loss from sport and concomitant injuries in athletes.

LEVEL OF EVIDENCE

Level IV.

A newly discovered membrane at the origin of the proximal tendinous complex of the rectus femoris

PURPOSE

The rectus femoris (RF) forms the anterior portion of the quadriceps muscle group. It has a proximal tendinous complex (PTC) which is constituted by a direct tendon (DT), an indirect tendon (IT), and a variable third head. Direct and indirect tendons finally converge into a common tendon (CT). All the PTC shows a medially sloping in its proximal insertion.We investigated several anatomical specimens and discovered a new component: a membrane connecting the CT with the anterior superior iliac spine. Such membrane constitutes a new origin of the PTC. The aim of this study was to clarify whether this membrane was an anatomical variation of the PTC or a constant structure and to describe its morphology and trajectory.

MATERIAL AND METHODS

We dissected 42 cadaveric lower limbs and examined the architecture of the PTC. We paid special attention to the morphology and interaction patterns between the tendons and the membrane.

RESULTS

We demonstrated that the membrane is a constant component of the PTC. It has a lateral to medial trajectory and is in relation to the common tendon, the DT, and IT, which present a medial slope. This suggests that the membrane has an stabilizer role for the PTC, acting as a corrector of the inclined vector of the complex.

CONCLUSION

The RF injuries are frequent in football. The newly discovered membrane is a constant component of the PTC and its integrity should be included in the algorithm to diagnose injuries.

Avulsion injuries: an update on radiologic findings

Avulsion injuries result from the application of a tensile force to a musculoskeletal unit or ligament. Although injuries tend to occur more commonly in skeletally immature populations due to the weakness of their apophysis, adults may also be subject to avulsion fractures, particularly those with osteoporotic bones. The most common sites of avulsion injuries in adolescents and children are apophyses of the pelvis and knee. In adults, avulsion injuries commonly occur within the tendon due to underlying degeneration or tendinosis. However, any location can be involved in avulsion injuries. Radiography is the first imaging modality to diagnose avulsion injury, although advanced imaging modalities are occasionally required to identify subtle lesions or to fully delineate the extent of the injury. Ultrasonography has a high spatial resolution with a dynamic assessment potential and allows the comparison of a bone avulsion with the opposite side. Computed tomography is more sensitive for depicting a tiny osseous fragment located adjacent to the expected attachment site of a ligament, tendon, or capsule. Moreover, magnetic resonance imaging is the best imaging modality for the evaluation of soft tissue abnormalities, especially the affected muscles, tendons, and ligaments. Acute avulsion injuries usually manifest as avulsed bone fragments. In contrast, chronic injuries can easily mimic other disease processes, such as infections or neoplasms. Therefore, recognizing the vulnerable sites and characteristic imaging features of avulsion fractures would be helpful in ensuring accurate diagnosis and appropriate patient management. To this end, familiarity with musculoskeletal anatomy and mechanism of injury is necessary.

Avulsion Injuries and Ruptures of the Proximal Rectus Femoris in Skeletally Mature, High-Level Athletes: A Critical Analysis Review

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Injuries to the proximal rectus femoris remain rare, occurring primarily in soccer and American football athletes during kicking and sprinting because of its unique biarthrodial nature.

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The appropriate diagnosis is dependent on careful physical examination and imaging interpretation.

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While no universal treatment algorithm has been adopted for high-level athletes, recent investigations support operative repair using suture anchors to restore strength and function in order to allow an effective return to competition while minimizing the risk of injury recurrence.

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Complications following surgical management include injury to the lateral femoral cutaneous nerve and hematoma formation, and there are reports of residual pain and weakness with chronic injuries that fail the initial nonoperative treatment.

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Current investigations examining outcomes following treatment remain limited, warranting additional studies that examine patient-reported results, return-to-play rates, and the role of orthobiologics and accelerated rehabilitation protocols following injury to further improve athlete health and safety.

[Proximal avulsion of the rectus femoris muscle]

BACKGROUND

Injuries of the thigh muscles are among the most frequent sports injuries. For example, in soccer they represent nearly 30% of all injuries. The rectus femoris muscle is particularly exposed to injury due to its anatomical features. While distal ruptures involve the quadriceps tendon and are among the more frequent injuries not only in sports, proximal ruptures represent a rarity. Because of the mostly indifferent clinical signs, the diagnosis is often delayed. In the literature various versions of classifications on the grading of muscle injuries have been described.

OBJECTIVE

With respect to the rectus femoris muscle, there is no classification system from which a treatment decision or an algorithm can be derived. The problem is not only the unclear classification of the injury but also the variability of treatment options resulting from this.

MATERIAL AND METHODS

A selective search of the literature was carried out to construct a review article.

RESULTS

No standardized follow-up treatment after surgical interventions or an established procedure for conservative treatment is currently available.

CONCLUSION

The comparison of the individual studies is made difficult due to the low case numbers and nonuniform classification systems. A valid treatment algorithm can only be derived with difficulty based on the currently available data.

Bicortical Titanium Tenodesis Button With Double-Row Fixation for the Treatment of Proximal Rectus Femoris Avulsion: Review of Literature and Surgical Technique

In adult populations, rectus femoris avulsions are reported in professional soccer and football players but are noted to be exceptionally rare. No gold standard or recommendations exist for this injury; however, in cases of avulsion at the anterior inferior iliac spine, positive outcomes appear to result from rest, immobilization, and rehabilitation. Surgery is typically reserved for cases with large retractions of bone fragments or unsuccessful nonoperative treatment. Surgical treatment methods vary from direct suture repair to single- and double-row bone suture placement and even muscle-muscle repair. We present our technique using a bicortical tenodesis button with double-row fixation for the treatment of a severely retracted rectus femoris tendon avulsion in a high-level athlete.

Outcomes of Surgical Repair Versus Primary Tenodesis for Proximal Rectus Femoris Avulsion Injuries in Professional Athletes

BACKGROUND

Surgical repair of proximal rectus femoris avulsion injuries is associated with prolonged periods of rehabilitation and highly variable risk of injury recurrence. Surgical tenodesis of these injuries is often reserved for recurrent injuries or revision surgery. To our knowledge, the outcomes of proximal rectus femoris avulsion injuries treated with surgical repair versus primary tenodesis have not been previously reported.

HYPOTHESIS

Primary tenodesis of proximal rectus femoris avulsion injuries is associated with reduced risk of injury recurrence as compared with surgical repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study included 25 patients (22 male and 3 female) who underwent surgical repair versus 30 patients (26 male and 4 female) who received primary tenodesis for proximal rectus femoris avulsion injuries. Predefined outcomes were recorded at regular intervals after surgery. Mean follow-up time was 27.9 months (range, 24.0-31.7 months) from date of surgery.

RESULTS

All patients returned to their preinjury levels of sporting activity. Primary tenodesis was associated with earlier return to preinjury level of sporting function as compared with surgical repair (mean ± SD, 12.4 ± 1.6 vs 15.8 ± 2.2 weeks; P < .001) and reduced risk of recurrence (0% vs 16%; P < .001). At 1-year follow-up, there was no difference in surgical repair versus primary tenodesis relating to patient satisfaction scores (12 very satisfied and 13 satisfied vs 16 very satisfied and 14 satisfied; P = .70), isometric quadriceps strength (95.6% ± 2.8% vs 95.2% ± 6.3%; P = .31), Tegner scores (median [interquartile range], 9 [8-9] vs 9 [8-9]; P = .54), and lower extremity functional scores (73 [72-76] vs 74 [72-75]; P = .41). High patient satisfaction, quadriceps muscle strength, and functional outcome scores were maintained and remained comparable between treatment groups at 2-year follow-up.

CONCLUSION

Primary tenodesis was associated with reduced time for return to preinjury level of sporting function and decreased risk of injury recurrence when compared with surgical repair for proximal rectus femoris avulsion injuries. There were no differences in patient satisfaction, functional outcome scores, and quadriceps muscle strength between the treatment groups at 1- and 2-year follow-up.

Operative versus conservative treatment of proximal rectus femoris avulsions: A systematic review with meta-analysis of clinical outcomes, complications and return to sports

PROSPERO REGISTRATION NUMBER

CRD42020198333.

OBJECTIVE

To compare the surgical and conservative treatment of proximal rectus femoris avulsions regarding clinical outcomes, rate of return to sports and incidence of complications.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane, Medline, Scopus and SPORTDiscus.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting on outcomes of PRFAs or return to sports were included.

RESULTS

Nine studies consisting of a total eighty-two patients met the inclusion criteria. The mean age was 22.2 years and 75.9% of patients were male. Mean follow-up was 28.9 months and 65% avulsions were managed surgically. The overall outcomes were similar in surgical and conservative treatment group (p = 0.72) with similar incidence of complications (14%). The rate of return to sports was 95% in surgical and 92.7% in the conservative management groups (p = 0.93). Overall, the quality of the methodology of included studies was low, with a mean CMS of 45.6.

CONCLUSION

Both conservative and operative treatment provide excellent outcomes in proximal rectus femoris avulsions, with similar rates of return to sports and incidence of complications. More prospective and good quality studies are needed to compare surgical techniques and time to return to sports. Avulsions with retraction of more than 20 mm and high demand patients may benefit from surgical treatment. Patients should be counselled accordingly.

Rectus femoris intrasubstance tear in a collegiate football kicker and its mechanism

Rectus femoris muscle belly tears have not been reported in the literature to our knowledge. This is a case of an isolated rectus femoris intrasubstance tear in a healthy college football kicker possibly caused by the eccentric and concentric load cycles associated with kicking activities. Dynamic ultrasound was crucial in establishing a diagnosis and investigating the mechanism behind this rare injury.

Post-traumatic ossifications of the rectus femoris: Arthroscopic treatment and clinical outcome after 2 years

Injuries of the rectus femoris tendon origin could result in a chronic tendinopathy, leading to groin pain and loss of function. Conservative treatment with analgesics and physical therapy is the gold standard, but in some cases excessive bone formation after avulsion injuries, can lead to a post-traumatic heterotopic ossification (PHO) and may benefit from surgical removal.

METHODS

Outcome was evaluated in 16 top soccer players (age 24-43 years) affected by calcification of the proximal rectus who underwent arthroscopic excision (6-12 and 24 months). X-ray and 3D CT was collected for all patients. Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, Modified Harris Hip Score, together with visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were used to evaluate clinical outcome. TECHNICAL PROCEDURE: after central compartment examination and treatment was accomplished, attention was focused to the ossification of the rectus femoris. A complete exposure of the ossification was achieved; when possible attention was taken in detaching the minimum amount of fibers of the direct head of the rectus femoris from its insertion site. During the entire procedure, both dynamic direct visualization and fluoroscopic evaluation of the amount of resection were performed.

RESULTS

Clinical outcome was excellent; the percentage of return to pre-injury level sport was 68.75 % (11 athletes), with significant statistical improvement of MHHS, OHS and all 3 VAS subscales in all patients at 2 years follow-up.

CONCLUSION

Arthroscopic removal using conventional hip arthroscopic portals represent both effective and safe procedure to adequately treat post-traumatic ossification of the rectus femoris.

US Assessment of Sports-related Hip Injuries

Traumatic and overuse hip injuries occur frequently in amateur and professional athletes. After clinical assessment, imaging plays an important role in diagnosis and in defining care management of these injuries. Ultrasonography (US) is being increasingly used in assessment of hip injuries because of the wide availability of US machines, the lower cost, and the unique real-time imaging capability, which allows both static and dynamic evaluation as well as guidance of point-of-care interventions such as fluid aspiration and steroid injection. Accurate diagnosis of hip injuries is often challenging, given the complex soft-tissue anatomy of the hip and the wide spectrum of injuries that can occur. To conduct a skillful US evaluation of hip injuries, physicians must have pertinent knowledge of the normal anatomy and should make judicious use of surface anatomy landmarks while using a compartmentalized diagnostic approach. In this article, common sports-related injuries of the anterior, lateral, and posterior hip compartments are discussed. This review includes assessment of joint effusion, acetabular labral tear, acute and chronic tendon injuries including tendinopathy, partial and full-thickness tears, snapping hip syndromes, relevant US-guided procedures, and some other conditions such as Morel-Lavallée lesion and perineal nodular induration. Principles of care management and current knowledge on imaging findings that may affect return to activity are also presented. Using an oriented US examination technique and having knowledge of the normal hip anatomy will help physicians characterize US findings of common sports-related hip injuries and make accurate diagnoses. Online supplemental material is available for this article. ^©RSNA, 2018.

Changes in rectus femoris architecture induced by the reverse nordic hamstring exercises

BACKGROUND

Injuries and mechanical stimuli alter the muscle architecture and, therefore, its function. The changes in the architecture of the rectus femoris (RF) induced by an eccentric training protocol with reverse nordic hamstring exercises (RNHE) have never been studied. Therefore, the aim of the present study was to determine the architectural adaptations of the RF after an eccentric training with RNHE, followed by a subsequent detraining period.

METHODS

Twenty-six subjects performed a first week of control, 8 weeks of eccentric training, concluding with a 4-week period of detraining. The architectural characteristics of the RF were evaluated using 2D ultrasound at rest (pretest: week 1), after the training (post-test: week 9), and at the end of the detraining period (retest: week 13).

RESULTS

At the end of the training period, a significant increase in the muscle fascicle length (FL) (t=-8.96, d=2.22, P<0.001), muscle thickness (MT) (t=-8.76, d=2.219, P<0.001), pennation angle (PA) (t=-9.83, d=2.49, P<0.05) and cross-sectional area (CSA) (t=-13.06, d=3.06, P<0.001) was observed. After the detraining period FL, MT, PA and CSA showed a significant decrease.

CONCLUSIONS

The eccentric training with RNHE may cause changes in the architectural conditions of RF, which, in addition, are also reversible after a 4-week detraining period. The adaptations produced by RNHE may have practical implications for injury prevention and rehabilitation programs, which include the changes in muscle architecture variables.

Nonoperative Management of a Severe Proximal Rectus Femoris Musculotendinous Injury in a Recreational Athlete: A Case Report

This report describes a severe injury to the proximal rectus femoris (RF) muscle in a 37-year-old recreational athlete. This injury is a relatively rare occurrence in both the general and elite athletic populations. Acute and long-term imaging and functional outcomes are described. This athlete was able to return to full activity without surgical intervention. Follow-up imaging demonstrated gross healing of both complete (or near complete) muscle and tendon tears. LEVEL OF EVIDENCE: V.

Sonographic Overview of Usual and Unusual Disorders of the Rectus Femoris Tendon Origins

Rectus femoris muscle proximal injuries are not rare conditions. The proximal rectus femoris tendinous anatomy is complex and may be affected by traumatic, microtraumatic, or nontraumatic disorders. A good knowledge of the proximal rectus femoris anatomy allows a better understanding of injury and disorder patterns. A new sonographic lateral approach was recently described to assess the indirect head of the proximal rectus femoris, hence allowing for a complete sonographic assessment of the proximal rectus femoris tendons. This article will review sonographic features of direct, indirect, and conjoined rectus femoris tendon disorders.

Musculoskeletal Approach to Pelvic Pain

Visceral and somatic causes of pelvic pain are often inter-related, and a musculoskeletal examination should always be considered for the successful diagnosis and treatment of pelvic pain. For the diverse etiologies of hip pain, there are many unique considerations for the diagnosis and treatment of these various disorders. Pelvic pain is often multidimensional due to the overlap between lumbo-hip-pelvic diagnoses and may require a multidisciplinary approach to evaluation and management.

Apophyseal injuries in children's and youth sports

INTRODUCTION

The authors reviewed the current English literature regarding apophyseal injuries affecting young athletes, to highlight the frequency and characteristics of these injuries, to clarify risk factors and specific prevention measures, and to identify future research objectives.

SOURCES OF DATA

The authors performed a comprehensive search of the medical literature, using the Medline database, including all English articles. Various combinations of the Keywords 'injury', 'sports', 'athletic injuries', 'avulsion fractures', 'physeal', 'physis', 'apophysis', 'apophysitis', 'growth plate' were used.

AREAS OF AGREEMENT

Growth benefits from a moderate physical activity.

AREAS OF CONTROVERSY

Growth deficit may occur in young athletes involved in intensive practice of sport following apophysitis.

GROWING POINTS

Apophyseal injuries occurring during sport are less common than overall rate of injuries affecting the adolescent population. Growth disturbance occurs only rarely after an apophyseal injury.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies should consider analytical as well as descriptive components of apophyseal injuries, to allow the identification of new possible risk factors and preventive measures and to help early detection and proper treatment as well.

Imaging of rectus femoris proximal tendinopathies

The rectus femoris is the most commonly injured muscle of the anterior thigh among athletes, especially soccer players. Although the injury pattern of the muscle belly is well documented, less is known about the anatomy and specific lesions of the proximal tendons. For each head, three distinctive patterns may be encountered according to the location of the injury, which can be at the enthesis, within the tendon, or at the musculotendinous junction. In children, injuries correspond most commonly to avulsion of the anteroinferior iliac spine from the direct head and can lead to subspine impingement. Calcific tendinitis and traumatic tears may be encountered in adults. Recent studies have shown that traumatic injuries of the indirect head may be underdiagnosed and that injuries of both heads may have a surgical issue. Finally, in the case of tears, functional outcome and treatment may vary if the rupture involves one or both tendons and if the tear is partial or complete. Thus, it is mandatory for the radiologist to know the different ultrasound and magnetic resonance imaging (MRI) patterns of these lesions in order to provide accurate diagnosis and treatment. The purpose of this article is to recall the anatomy of the two heads of rectus femoris, describe a reliable method of assessment with ultrasound and MRI and know the main injury patterns, through our own experience and literature review.

Suture anchor repair of proximal rectus femoris avulsions in elite football players

PURPOSE

To report the results of suture anchor repair of proximal rectus femoris avulsions in elite football players.

METHODS

Four professional football players (first-team regulars of European first division football clubs) underwent suture anchor repair of complete proximal rectus femoris avulsions with significant tendon retraction. The following parameters were analysed: demographic data, mechanism of injury, type of injury, classification according to the Munich consensus statement, time between injury and surgery, time between surgery and full participation in training and availability for match and/or competition selection (return to play/RTP), and time between surgery and the comeback to the first official league match (return to competition/RTC). Radiographic evaluation was performed by magnetic resonance imaging (MRI) obtained pre-operatively and at 6 and 12 weeks post-operatively. All players were followed for at least 24 months after return to play to exclude recurrence.

RESULTS

Mean age at surgery was 30 ± 2 years. All injuries occurred while kicking a ball, with the dominant leg affected in all patients. The injury was considered acute in three cases and chronic in one case. According to the Munich classification, all injures were type 4. Mean time to surgery was 60 ± 88 days (range, 8-191), mean time to RTP was 111 ± 15 days (range, 100-134), and mean time to RTC was 140 ± 23 days (range, 114-166). Follow-up MRIs demonstrated anatomically reinserted tendons with decreasing signal intensity over time in all cases. After a mean follow-up of 35 ± 6 months, all players were still competing at the same level as before the injury without re-injury.

CONCLUSION

Suture anchor repair of proximal rectus femoris avulsions allows unrestricted return to play in professional elite football players. Return to play can be expected at approximately 16 weeks post-operatively.

An anatomical study of the indirect tendon of the rectus femoris using ultrasonography

The aim of this study was to demonstrate that ultrasound can allow a precise assessment of the indirect tendon of the rectus femoris using a new lateral approach.

METHODS AND MATERIALS

Four hips were dissected for the anatomical study of the proximal rectus femoris insertions. Under ultrasonographic guidance, spinal needles piercing the direct tendon were placed in the indirect tendon, following by dissection. Then, high-resolution ultrasound was performed in 20 volunteers with assessment of the indirect tendon of the rectus femoris.

RESULTS

At dissection, the spinal needles were located in or immediately adjacent to the indirect tendon, thus confirming that it was correctly depicted by ultrasound. The indirect tendon could be identified in each cadaver and each volunteer with ultrasound. The optimal position of the probe to allow assessment of the indirect tendon could be defined. No significant changes in the appearance or thickness of the tendon could be observed.

CONCLUSION

The results of our study showed that the indirect tendon of the rectus femoris muscle can be clearly depicted by sonography in healthy adult subjects. The potential applications of this new use of sonography must now be confirmed by clinical studies.

KEY POINTS

• The anatomy of the proximal rectus femoris is reviewed • Until now, sonography was limited for assessing direct and conjoined tendons • The indirect tendon can be clearly depicted by sonography • A new lateral approach for studying the indirect tendon is described.

Avulsion fractures involving the straight and reflected heads of the rectus femoris

Tumours and sport injuries can both affect active, young patients, and the symptoms of the two often overlap. Neglected avulsion injuries sometimes cause a mass to develop which can mimic a tumour. We discuss the diagnosis, treatment, and results following nine anterior inferior iliac spine (AISS) avulsion fractures.

Rectus Femoris Tendon Calcification: Arthroscopic Excision in 6 Top Amateur Athletes

Background:

Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach.

Purpose:

To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment.

Study Design:

Case series; Level of evidence, 4.

Methods:

Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used.

Results:

One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05).

Conclusion:

Arthroscopic excision of rectus femoris tendon calcification yields satisfying results with few risks to the patient as well as rapid recovery.

Clinical Relevance:

The recent improvements in hip arthroscopy give the opportunity to address an increasing number of hip conditions effectively and safely, with rapid recovery for the patient. Arthroscopic excision of rectus femoris tendon calcification can be considered a feasible option, with few risks to the patient, rapid recovery, and satisfying outcomes.

A Unique Rectus Femoris Injury in an Adolescent Professional Soccer Player: A Case Report

CASE

A sixteen-year-old professional soccer player presented with persistent pain in the right thigh of two years' duration and the inability to return to play. Evaluation revealed a chronic rupture of the rectus femoris muscle. Because physiotherapy and rehabilitation failed to help, a surgical repair was performed. He returned to his previous activity level within nine months after surgery.

CONCLUSION

Rupture of the proximal part of the rectus femoris should be acknowledged in the differential diagnosis, especially when presenting with persistent pain in the anterior aspect of the thigh lasting more than one year. Delayed repair might be recognized as a reasonable option for chronic rupture of the proximal part of the rectus femoris.

Avulsion fracture of the anterior inferior iliac spine mimicking a bone tumor: a case report

This is a case of a 17-year-old boy who was admitted to the clinic suffering from right hip-inguinal region pain which began after a soccer match. He had an avulsion fracture in the anterior inferior iliac spine and CT/MR images showed similarities to a bone tumor. These fractures are especially seen in the apophyses which are within the ossification process. The radiological appearance of these fractures during the healing period may be involved with bone tumors. In the control MRI of the patient after one year, the fracture was almost healed completely. Treatment is generally conservative. Good results have been reported with rest, analgesic and anti-inflammatory drugs. Familiarity with radiological findings of these avulsion fractures in this region not only protects the patient from invasive procedures but also avoids the involvement of the practitioner in legal consequences resulting from a misdiagnosis of sarcoma.

The recognition and evaluation of patterns of compensatory injury in patients with mechanical hip pain

Context:

In active individuals with femoroacetabular impingement (FAI), the resultant reduction in functional range of motion leads to high impaction loads at terminal ranges. These increased forces result in compensatory effects on bony and soft tissue structures within the hip joint and hemipelvis. An algorithm is useful in evaluating athletes with pre-arthritic, mechanical hip pain and associated compensatory disorders.

Evidence Acquisition:

A literature search was performed by a review of PubMed articles published from 1976 to 2013.

Level of Evidence:

Level 4.

Results:

Increased stresses across the bony hemipelvis result when athletes with FAI attempt to achieve supraphysiologic, terminal ranges of motion (ROM) through the hip joint required for athletic competition. This can manifest as pain within the pubic joint (osteitis pubis), sacroiliac joint, and lumbosacral spine. Subclinical posterior hip instability may result when attempts to increase hip flexion and internal rotation are not compensated for by increased motion through the hemipelvis. Prominence of the anterior inferior iliac spine (AIIS) at the level of the acetabular rim can result in impingement of the anterior hip joint capsule or iliocapsularis muscle origin against the femoral head-neck junction, resulting in a distinct form of mechanical hip impingement (AIIS subspine impingement). Iliopsoas impingement (IPI) has also been described as an etiology for anterior hip pain. IPI results in a typical 3-o’clock labral tear as well as an inflamed capsule in close proximity to the overlying iliopsoas tendon. Injury in athletic pubalgia occurs during high-energy twisting activities in which abnormal hip ROM and resultant pelvic motion lead to shearing across the pubic symphysis.

Conclusion:

Failure to recognize and address concomitant compensatory injury patterns associated with intra-articular hip pathology can result in significant disability and persistent symptoms in athletes with pre-arthritic, mechanical hip pain.

Strength-of-Recommendation Taxonomy (SORT):

B

The association between avulsions of the reflected head of the rectus femoris and labral tears: a retrospective study

BACKGROUND

The aim of this study was to investigate if an association existed between the reflected head of rectus femoris avulsion injuries and labral tears in pediatric patients referred for magnetic resonance arthrography (MRA) or magnetic resonance imaging (MRI) evaluation.

METHODS

Electronic medical records of the patients between the ages of 12 and 18 who were treated at the hospitals affiliated by McMaster University between June 2000 and November 2010 with a diagnosis of rectus femoris avulsion injuries were retrospectively identified and analyzed. Patients were included if they had magnetic resonance imaging or MRA images of their hip.

RESULTS

Nine patients with avulsion injuries of the rectus femoris muscle were identified. The patient population consisted of 4 females and 5 males (range, 8 to 17 y, mean age 14 y). All injuries occurred during sports activity, which included running and kicking during soccer, skating in hockey, and a squatting exercise. MRA examination of 7 of these patients demonstrated associated labral tears. All patients were initially treated conservatively. Five patients continued to sustain from residual pain in the 9 months after the initial injury. Two of these patients with significant refractory pain were subsequently treated with hip arthroscopy. Intraoperatively, 1 small labral tear and 1 labral avulsion were identified and treated.

CONCLUSIONS

This study suggests that there may be an association between avulsion of the reflected head of rectus femoris and labral injuries and that there may be an underlying spectrum of traction injuries. Patients with rectus femoris avulsion injuries with persistent symptoms may be at risk for concurrent traumatic labral tears.

LEVEL OF EVIDENCE

Level 4, retrospective case series.

The hip antero-superior labral tear with avulsion of rectus femoris (HALTAR) lesion: does the SLAP equivalent in the hip exist?

BACKGROUND

The purpose of this report is to describe a new lesion, the "Hip Antero-superior Labral Tear with Avulsion of Rectus femoris (HALTAR)". This injury may be seen in both adolescent and skeletally mature athletes and shares several characteristics with the "Superior Labral tear from Anterior to Posterior (SLAP)" lesion in the shoulder.

METHODS

We present a case example, as well as a detailed anatomic description of the pathological condition.

RESULTS

As the rectus femoris crosses two joints it is exposed to substantial forces during muscle contraction. Considering the peri-articular origin of the reflected head at the superior aspect of the acetabular rim, a powerful eccentric contraction of the rectus femoris muscle or traction related to sudden knee flexion may cause an avulsion injury of the rectus femoris as well as a concomitant labral tear.

CONCLUSIONS

A strain injury of the rectus femoris muscle, which is common in young athletic patients, may cause a concomitant tear of the acetabular labrum. Therefore, we recommend further diagnostic work-up in cases with prolonged hip pain and impaired hip function following an AIIS injury in order to identify any associated peri- and intra-articular damage. In our experience these patients seldom need aggressive surgical management.

Arthroscopic excision of heterotopic calcification in a chronic rectus femoris origin injury: a case report

Rectus femoris origin injuries in adult athletes are uncommon. In the acute phase, conservative treatment seems to have a favourable outcome, with surgical repair reserved for unsuccessful cases only. However, a group of patients may develop chronic pain and disability after recovery from the acute phase due to heterotopic calcification occurring at the site of injury. Open and arthroscopic excision of such calcifications has been described in the literature although arthroscopic excision of large calcified lesions in the rectus femoris has not been reported previously. A relevant case is presented and discussed.

Surgical treatment of proximal ruptures of the rectus femoris in professional soccer players

INTRODUCTION

Muscle injuries are very common in athletes. Depending on the type of sport, muscle injuries represent approximately 9-54% of total injuries. The rectus femoris muscle is very important in specific sports, such as soccer and American football, because it is the muscle involved in movements, such as sprinting and kicking the ball. Therefore, we believe that these disabling injuries need special and prompt treatment to enable athletes to return to their sporting activities.

AIM

The aim of our study is to assess the results of surgical treatment of ruptures of the rectus femoris in professional soccer players by reattachment of the tendon. We identified ten proximal rectus femoris ruptures in professional soccer players belonging to the Spanish Football League.

RESULTS

Mean follow-up was 34.8 months (SD + 28.72). The mean age of the players was 27.4 years (SD + 4.14). In six cases (60%), the tendon was repaired by direct suture with non-absorbable sutures. In four cases, where there had been complete avulsion, bone anchoring sutures were used. There is no consensus regarding the optimal treatment for ruptures of the rectus femoris muscle. There are a few reports in the literature based on isolated experiences of different surgeons.

CONCLUSION

Surgical treatment has a lower recurrence rate in our hands; we believe that surgical treatment is indicated in these cases, for a complete functional recovery for professional soccer players.

Chronic tears of the reflected head of the rectus femoris: results of operative treatment

BACKGROUND

While the majority of quadriceps muscle strains can be managed nonoperatively, rare cases remain symptomatic despite nonoperative treatment.

PURPOSE

The purpose of this study is to report on results of surgical treatment of a limited number of cases of persistently symptomatic tears of the reflected head of the rectus femoris.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The records of 5 patients with chronic tears of the rectus femoris treated with excision of the reflected head were reviewed. A telephone interview regarding return to sport and current limitations was completed if patients were available for further follow-up.

RESULTS

A review of 5 cases of surgical treatment of chronic tears of the reflected head of the rectus was completed. Patients included 1 woman and 4 men with an average age of 21 years (range, 18-24 years). Three patients played football (2 kickers) and 2 played soccer at a collegiate level. All 5 reported a significant decrease in pain during sport and activities of daily living and were able to return to collegiate athletics. Two patients had a late recurrence of pain with kicking that resolved with nonoperative treatment, 1 had residual thigh pain with intense play, 1 had no pain but noted decreased kicking accuracy, and 1 patient returned to play without symptoms.

CONCLUSION

Strain injuries to the reflected head of the rectus femoris can benefit from delayed excision in rare cases that fail nonoperative management. High-level kicking athletes are likely to experience significant reduction in pain, but may have some residual or recurrent symptoms that limit competitive level of play postoperatively.

Soft tissue pathology around the hip

Snapping hip syndromes have been treated with open surgery for many years. Recently, endoscopic techniques have been developed for treatment of snapping hip syndromes with results that are at least comparable if not better than those reported for open procedures. The greater trochanteric pain syndrome is well known by orthopedic surgeons. However, deep understanding of the pathologic conditions generating pain in the greater trochanteric region and endoscopic access to it has only recently been described. Although evidence regarding endoscopic techniques for the treatment of the greater trochanteric pain syndrome is mainly anecdotal, early published reports are encouraging.

Enthesitis of the direct tendon of the rectus femoris muscle in a professional volleyball player: A case report

Enthesitis of the direct tendon of the rectus femoris muscle is a rare pathology which mainly affects professional athletes, and it is caused by overuse and repetitive microtrauma. Athletic jumping and kicking exert a great stress on the direct tendon of the rectus femoris muscle, and volleyball and football players are therefore most frequently affected. Enthesitis may occur suddenly causing pain and functional impairment possibly associated with partial or complete tendon injuries, or it may be a chronic condition causing non-specific clinical symptoms.We present the case of a professional volleyball player who felt a sudden pain in the left side of the groin area during a training session although she had suffered no accidental injury. The pain was associated with impaired ipsilateral limb function. Tendon rupture was suspected, and magnetic resonance imaging (MRI) was performed. MRI showed a lesion at the myotendinous junction associated with marked inhomogeneity of the direct tendon. Ultrasound (US) examination confirmed the presence of both lesions and allowed a more detailed study of the pathology.This is a typical case of enthesitis which confirms that MRI should be considered the examination of choice in hip pain, particularly when the patient is a professional athlete, thanks to its panoramic visualization. However, also US is an ideal imaging technique for evaluating tendon injuries thanks to its high spatial resolution, and it can therefore be used effectively as a second line of investigation.

Sonography of the quadriceps muscle: Examination technique, normal anatomy, and traumatic lesions

Lesions of the quadriceps muscle (QM) are frequently seen by sonographers, and in most cases they are the result of sports-related trauma. An accurate assessment of the severity of the lesion is essential, particularly when the patient is a professional athlete. In most cases, careful history-taking and a thorough physical examination are sufficient for making the diagnosis and indicating the most suitable imaging studies for each case. Clinical assessment alone, however, may not be sufficient for distinguishing contusions from small, partial tears or for estimating the size of a tear. Therefore, at least in patients who are professional athletes, imaging studies are necessary to plan appropriate therapy that will allow prompt functional recovery. Muscles cannot be visualized with conventional radiography, but it is used routinely in prepubertal patients because it can detect apophyseal detachments, which are the most frequent muscle lesion in this age group. Radiography is also useful when myositis ossificans is suspected. Magnetic resonance imaging, thanks to its excellent tissue contrast, allows simultaneous assessment of muscle, joint, and bone planes. It remains a second-line study due to its high cost and relatively low availability. It is also associated with various contraindications, the most important of which is the presence of a cardiac pacemaker. Ultrasonography has a number of advantages, including widespread availability, absence of contraindications, and low cost. It can also be used for dynamic studies of the muscle during contraction and relaxation, and if doubts arise, scans can easily be obtained of the contralateral muscle for comparison purposes. These qualities make it an excellent tool for follow-up of patients with QM lesions, when follow-up is necessary. This article reviews the anatomy of the QM, the technique used for standard ultrasound examination of this muscle, its normal appearance on ultrasound, and the sonographic characteristics of the most common traumatic lesions that affect it.

Sports injuries in young athletes: long-term outcome and prevention strategies

Physical activity plays a significant role in the physical and emotional well-being of a child. In the past 15 to 20 years, there has been a dramatic increase in sports participation at a young age, which has offered numerous health benefits, including self-esteem, confidence, team play, fitness, agility, and strength. Children are playing sports at younger ages. This article assesses the long-term outcome of sports injuries in young athletes, with suggestions on how to prevent such injuries. There are no definitive epidemiological data on withdraw from sports activities due to injury in young athletes. Disturbed physeal growth as a result of injury can result in length discrepancy, angular deformity, or altered joint mechanics, and may cause significant long-term disability. Sequelae of Osgood-Schlatter lesion include painful ossicle in the distal patellar tendon. Fragmentation or separation of the apophysis appears to be the result of adaptive changes to the increased stress that occurs in overuse activities. The presence of these changes undeniably demonstrates an osseous reaction, although they are not disabling. Promotion of a physically active lifestyle is encouraged worldwide, particularly with regard to the many health benefits. Reduction of only a moderate proportion of all sports injuries is of significance for the young athletes' health and could have a long-term economic impact on health care costs. It is therefore important to convince medical doctors, physical therapists, athletic trainers and coaches, as well as athletes of the necessity to implement active prevention measures in their therapy and training programs, thus decreasing the injury and re-injury rate and enhancing athletic performance.

Injuries and conditions of the extensor mechanism of the pediatric knee

The extensor mechanism of the knee is essential to ambulation and is subject to a number of traumatic, congenital, and inflammatory processes. In the pediatric population, the spectrum of pathologic conditions affecting the extensor mechanism is specific to skeletally immature patients. In addition, certain congenital and developmental disorders may further predispose the knee extensor mechanism to injury. The pathologic processes can be subdivided into categories: conditions of the attachments and insertions of the quadriceps and patellar tendons, conditions of the patella, conditions of the quadriceps muscle group, and avulsions of the superior attachments of the quadriceps. Cases of conditions affecting the extensor mechanism of the pediatric knee were collected at two large trauma centers, and the clinical and radiologic features were reviewed. Initial evaluation of these conditions is performed with radiography, but magnetic resonance imaging has evolved into a useful adjunct for assessing the soft tissues for a more precise evaluation of the true extent of an injury, thereby affecting decisions about surgical intervention and prognosis.

Nonoperative treatment for proximal avulsion of the rectus femoris in professional American football

BACKGROUND

Avulsion of the rectus femoris origin is a rare injury. The only previous report of this injury in professional American football has been limited to the kicking athlete.

PURPOSE

To describe the incidence and treatment of proximal rectus femoris avulsion in the National Football League (NFL).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The NFL Injury Surveillance System (NFLISS) was reviewed for any proximal rectus femoris avulsion injuries from 1986 to 2006, including the type and mechanism of injury, player demographics, method of treatment, and time to return to play. The NFL team physicians and trainers were surveyed as to their experience with these injuries as well.

RESULTS

A total of 11 cases of proximal rectus femoris avulsion were identified starting in 1997. These injuries occurred in athletes in a variety of positions. All of these were treated nonoperatively, and the mean return to play was 69.2 days.

CONCLUSION

Rectus femoris avulsions are uncommon injuries in the NFL, occurring about once a year in the entire league (once magnetic resonance imaging facilitated correct diagnosis of these injuries). Conservative treatment of these injuries usually results in return to play after 6 to 12 weeks.

CLINICAL RELEVANCE

Proximal avulsions of the rectus femoris can be treated nonoperatively with a high degree of predictability for return to full, unrestricted participation in professional American football.