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

Abstract

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.

Summary Box.

1. Background

Damage to the musculo-tendinous junction of the quadriceps is frequent, but injuries to the proximal rectus femoris remain rare, accounting for less than 1% of hip injuries occurring during sports activity.¹ Proximally, the muscle originates from two landmarks-the direct head of the muscle originates from the anterior inferior iliac spine (AIIS) and the reflected or indirect head arises from the superior acetabular ridge with some fibres inserting onto the hip capsule.^2,3 Traumatic avulsions of the reflected head could be associated with concomitant injury to labrum, capsule, and acetabular cartilage, as these structures are in close proximity with the origin of the reflected head.

The rectus femoris muscle is particularly important in specific sports, such as soccer and American football, as it is mainly involved in movements, such as sprinting and kicking the ball. They generally affect top-level athletes because of sudden eccentric contraction in the position of muscle elongation (hip extension, knee flexion) such as kicking the ball against resistance or landing from a jump.⁴ It is often initially misdiagnosed, leading to a delay in treatment.^5,6

Clinical Presentation and Diagnosis- Patient generally present with a typical history of sudden pain during hip extension or forceful flexion while sprinting or kicking the ball, together with weakness and pain during hip flexion.⁷ The primary diagnosis is made using MRI of the pelvis, which is the main diagnostic tool for PRF injuries. Historically, most of these injuries have been treated non-operatively.⁸However, there is no therapeutic consensus clearly established for proximal rupture of the rectus femoris tendon based on the type of avulsion and patient population. Sport-specific outcomes have not been well studied with regards to conservative and surgical management and there is paucity of data on the incidence of complications like lateral femoral nerve palsy, re-rupture rate, persistent pain or functional restrictions.

The purpose of this systematic review and meta-analysis was to analyse all studies reporting outcomes, return rates and times to sport and complications following treatment for PRFAs, in order to provide clarification on the optimal treatment methods for this injury, to provide prognostic information on return to sport following this condition and to give support in the decision making process regarding treatment options for such injuries. Our hypothesis was that surgical treatment allowed a better and earlier functional recovery with resumption of the same sports and professional activities at the pre-injury level.

2. Methods

2.1. Protocol and registration

The authors followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines to design the review.⁹ The protocol was registered in the international prospective register of systematic reviews, PROSPERO, and met all the criteria for protocol registration.

2.2. Literature search

A systematic review was carried out in July 2020 from the following databases: Cochrane Collaboration Database, Medline (PubMed), Scopus and SPORTDiscus. This was to locate all articles, in peer-reviewed journals, published in English language, reporting on outcomes, return rates and times to sports and complications following treatment for PRFAs. No distinction was made regarding the nature of avulsion nor type or level of sports activity performed. The search strategy combined the following terms, along with the Boolean operators(OR; AND): ‘proximal’, ‘rectus’, ‘femoris’, avulsion’, ‘injury’, ’non-operative’, ’conservative’, ’operative’, ‘outcomes’, ‘return to sport’. No limits were set regarding the year of publication.

All three authors (S.D., R.K., and A.C.), to establish its suitability for inclusion within the review, independently reviewed the abstract of each publication. Fig. 1 shows the flowchart of selection of articles for inclusion in the review in accordance with the PRISMA guidelines. Inclusion criteria for studies was as follows:

• •PRFAs (Grade 4-Munich consensus statement¹⁰)
• •Elite or recreational athletes
• •Outcomes and/or return rate to sporting reported
• •Case studies (4 or more patients)
• •Peer reviewed journals
• •English language

Fig. 1.

Flowchart of selection of articles for inclusion in the review in accordance with the PRISMA guidelines.

Studies excluded from the review included case reports, abstracts, expert opinions, technical notes, and animal or cadaver studies, or in which sporting outcome data was not reported. Full texts were studied to confirm eligibility if authors were not able to exclude a study from the abstract alone. Reference lists of relevant articles were also reviewed to identify additional studies that could be suitable for inclusion. Any discrepancies regarding the include studies were resolved by consensus discussion: however, there were no major disagreements regarding the articles to include.

2.3. Data extraction

Patient demographics, mechanism of injury, pre-operative radiological investigations, type of avulsion, operative and non-operative management techniques, rehabilitation protocol, clinical and functional outcomes, return rates to sport, return times to sports and complications encountered in the treatment modality used were include in the review database.

The primary outcome measures were clinical outcomes of the conservative or surgical treatment employed for the injury. The secondary outcomes were return rates to sport, return times to pre-injury level of sport, and associated complications encountered in the follow-up. Return time to sport was defined as the time from starting non-operative treatment modalities to returning to sports for conservatively managed patients and the time from primary surgery to returning to sports for surgically managed patients.

2.4. Quality assessment

The modified Coleman Methodology Score (CMS) was used to assess the quality of methodology of the included articles.¹¹ It is a validated scoring system consisting of 10-point criteria, which has been previously used in multiple similar systematic reviews.^12,13 The scoring methodology utilized is that presented by Del Buono et al.¹¹ The final score ranges from zero to 100, with a score below 50 indicating low quality of study. If the score is between 50 and 69, the study is designated as moderate, between 70 and 84 good and excellent if the score is greater than 85.¹⁴ Moreover, all included studies were evaluated according to the level of evidence as defined by the Oxford Centre for Evidence Based Medicine.¹⁵

2.5. Statistics

The data was analysed using Excel Version 14.3.9, IBM SPSS software version 17 and Review manager version 5.4. Descriptive statistics and frequency-weighted means were used to report patient demographics and study characteristics. A p-value of <0.05 was considered significant. Meta-analyses were performed to calculate the overall pooled rate of clinical outcome, complications, and return to sports. This was plotted using the random effects model and Forest plot. Heterogeneity was assessed using the method of Higgins et al. and expressed as I,² which can range from 0% expressing complete consistency to 100% expressing complete inconsistency of the data.¹⁶

3. Results

3.1. Study characteristic and quality assessment

Out of 352 articles identified through the initial search and 3 additional records detected through reference lists, nine studies met the inclusion criteria^7,8,.17, 18, 19, 20, 21, 22, 23 The flow diagram according to PRISMA guidelines summarizes the selection protocol (Fig. 1). Patient demographics and study characteristics are as shown in Table 1. The mean CMS for all studies was 45.6(range 31–65) (Table 1). The methodology quality of included studies was therefore low to moderate. For the studies reporting on conservative management, the mean CMS was 33.3 (range 31–36). For the studies reporting on surgical management, the mean CMS was 51.8(range 41–65). All studies were case series with level IV evidence. There were no prospective or retrospective cohort studies. There were no randomised controlled trials (RCTs).

Table 1.

Proximal Rectus Femoris Avulsions-All studies with follow-up data included.

Author(year)	n	Male/female	Level of evidence	Treatment	Sporting activity	Coleman score	Mean follow-up months(range)
Irmola (2007)	5	5/0	CS(IV)	Surgical	Soccer-4,Hurdler-1	53	26 months(9–45)
Gamradt (2009)	11	11/0	CS(IV)	Conservative	American Football	33	37 months (12–132)
Garcia (2011)	10	10/0	CS(IV)	Surgical	Soccer	48	30.3 months(13–63)
Foote (2013)	9	5/4	CS(IV)	Conservative	Soccer, skating	36	15 months(8–18)
Uzun (2014)	9	9/0	CS(IV)	Conservative	Soccer-8,athletics-1	31	26 months(12–48)
Ueblacker (2014)	4	4/0	CS(IV)	Surgical	Soccer	54	35 months
Sonnery-Cottet (2017)	5	N/A	CS(IV)	Surgical	Soccer	65	18.2 months(9–32)
Sinikumpu (2017)	11	N/A	CS(IV)	Surgical	Different sports	41	Not mentioned
Lempainen (2018)	18	18/0	CS(IV)	Surgical	Soccer	50	34 months(12–132)
Summary	82	63/4	CS(IV)	Conservative-3 Surgical-6		45.6	28.9 months

3.2. Patient characteristics

A total of 82 patients were enrolled in this meta-analysis. One patient had bilateral avulsions. Of the 83 avulsions, 63 (75.9%) occurred in male patients, 4(4.8%) in female patients and 16(19.2%) failed to specify gender. The mean age at the time of injury ranged from 14^{19, 20}–31.8 years,²² with a mean age across all studies of 22.2 years. The sporting activities commonly practised were soccer and American football. The mean follow-up ranged from 15 months to 37 months, with a combined mean follow-up of 28.9 months.

3.3. Type of avulsion

Seven studies reported on tendon avulsions while two studies reported on bony avulsions. Five studies mentioned additional retraction of the tendon, however only two studies mentioned about the amount of retraction.^21,23 One study did MRA to diagnose associated intra-articular pathology.¹⁹

Sixty-two avulsions involved a single tendon (either direct or reflected head) and 21 avulsions involved both the tendon heads.

Of the 83 total avulsions, 29 were managed conservatively and 54 were managed surgically.

3.4. Preceding history

All of the studies reported on the mechanism of injury and duration and nature of the symptoms following the injury. The mean duration from onset of symptoms until diagnosis ranged from one day⁷ to 90 days.²⁰ The most common reported symptom was pain during hip flexion.

3.5. Choice of radiological imaging

All the studies reported the modality of radiological imaging used to diagnose the injury. MRI was used in seven studies whereas Ultrasound as an adjunct investigation was used in two studies.^17,18 X-ray was mentioned in one study.²³ In study, MRA was performed for 7 out of 9 patients.¹⁹

3.6. Management

3.6.1. Conservative management

There were 29 patients managed conservatively^{8, 19, 20}. There is no fixed management protocol; however, in general treatment consisted of ice, NSAIDs analgesia and supervised physiotherapy as per the individual’s pain and symptoms. Gamradt et al. mentioned about the rehabilitation protocol in one of his players in his series of nine NFL players treated conservatively.⁸This consisted of 1 week of protected weight bearing with crutches, active range of motion and isometric exercises from week 2 and resistance strengthening exercises from week 4. In the second player, light jogging was started at 9th day post injury and the player return to practice at 2 week and returned to play at 3 weeks.

3.6.2. Surgical management

There were 54 avulsions managed surgically.^7,17,18,21, 22, 23 The mean time to surgery ranged from 9.1 days to 60 days for acute injuries (n = 46) and from 77.5 days to 191 days (n = 8) for chronic injuries. Chronic injuries included those, which were treated conservatively initially until recurrent injuries occurred or pain and weakness prevented training and return to play.

The reported techniques were repair using suture anchors (n = 39,72.2%),^{7,17,18,21,23} resection of the torn tendon or bony fragment and suturing of muscle (n = 7, 12.9%),^22,23 end to end repair (n = 3, 5.6%),¹⁸ mobilisation of muscle belly and suturing proximally for tears >4 cm distal to insertion (n = 3, 5.6%)¹⁸ and suturing the torn tendon or bony fragment through bone tunnels (n = 2, 3.7%).²³ Garcia et al. also reported using platelet rich growth factor (PRGF) to improve recovery, using Anitua technique.²⁴

Four studies mentioned about the approach used for surgery. Three of them performed through the anterior approach,^7,18,22 while one used the anterolateral approach.¹⁷

Post-operative rehabilitation following the surgical treatment was as follows in general: Patient was non-weight bearing for 1 week post-operatively and hip was kept flexed at 45° using a pillow^7,17 or brace.¹⁸ Thereafter, partial weight bearing using crutches was allowed for 2 weeks, followed by full weight bearing within pain limits. Hip extension, cycling and aqua training was allowed after 4 weeks. Eccentric exercises were started at 6 weeks, running and sport-specific training at 8 weeks and return to play at 3 months. Sonnery-Cottett et al. whose technique involved resection of the tendon heads and suturing of the muscle, immediately mobilised using crutches for 2 weeks, followed by progressive range of motion from 2 to 6 weeks.²² Strengthening exercises were commenced at 6 weeks followed by sport-specific training at 8 weeks. Ueblacker et al. performed MRI and US at 6 and 12 weeks to assess the healing of the repair.²¹Sonnery-Cottett et al. and Lempainem et al. assessed clinical strength by isokinetic testing at 3 months before the athlete is allowed to return to play.^7,22

3.6.3. Functional assessment

The outcomes were quantified as excellent (full return to preinjury level of sports without any symptoms), good (full return to preinjury level of sport with some residual symptoms), moderate (return to lower level of sports with some residual symptoms which did not interfere with activities of daily living) or poor (pain and/restrictions in activities of daily life). One study used mean WOMAC score for functional assessment post-intervention.²⁰ One study used Marx activity rating Lower Extremity Functional Scale (LEFS) post-intervention for all patients.²² The rate of excellent outcome was not significantly different (p = 0.72) in patients receiving surgical treatment with 91% (95% CI, 0.82 to 0.96) as compared to those receiving conservative treatment with 92.7% (95% CI, 0.76 to 0.99). The random effect model showing patients having excellent outcome at follow-up with forest plots for surgical and conservative group are as shown in Fig. 2 and Fig. 3 respectively.

Fig. 2.

Random effect model displaying the patients (percentage) with excellent outcome at follow-up with forest plots for surgical group. The diamond delineates the weighted pool with confidence intervals. The horizontal lines correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 0%, p = 0.67.

Fig. 3.

Random effect model displaying the patients (percentage) with excellent outcome at follow-up with forest plots for conservative group. The diamond delineates the weighted pool with confidence intervals. The horizontal lines correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 46.55%, p = 0.154.

3.6.4. Return rates to sports

Eighty-two patients were evaluated regarding return to sports at the preinjury level. The rate of return to sports of all patients (combined) by meta-analysis according to the random effects model was 94% (95% CI, 0.88 to 0.98). 95% of surgical and 92.7% of conservatively treated patients (p = 0 0.93) returned to pre-injury level of sports at follow-up (Fig. 4 and Fig. 5). Six studies (5 from the surgical group and 1 from the conservative group) (n = 46) have reported the mean time to return to play. For, patients operated for acute PRFAs (n = 32) by surgical management, the combined mean time to return to play was 112.6 days (range from 80.5 to 240 days). For patients operated for chronic injuries, five patients were not reported. The mean time to return to play for the remaining three patients was 204.6 days (range 134–270 days). For patients treated conservatively (n = 11), the mean time to return to play was 69.2 days (range 21–208 days).

Fig. 4.

Random effect model displaying the patients (percentage) who returned to their preinjury activity-level in surgical group. The diamond delineates the weighted pool with confidence intervals. The horizontal lines correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 0.00%, p = 0.56.

Fig. 5.

Random effect model displaying the patients (percentage) who returned to their preinjury activity-level in conservative group. The diamond delineates the weighted pool with confidence intervals. The horizontal lines correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 43.8%, p = 0.16.

3.6.5. Complications

Complications were assessed in 72 patients (14%) and eight studies. One study did not report the complication rate in the patients treated for PRFAs.²³ The overall complication rate according to the random effects model was 14% (95% CI, 0.06 to 0.24) (Fig. 6 and Fig. 7). There was no statistical difference (p = 0.74) between the individual complication rate in conservative (14.3%) and surgical group (14.7%).

Fig. 6.

Random effect model displaying the percentage of complications in surgical group. The horizontal lines extending out of the squares correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 26.2%, p = 0.24.

Fig. 7.

Random effect model displaying the percentage of complications in conservative group. The horizontal lines extending out of the squares correspond to the 95% CI surrounding the best estimate. Heterogeneity I² = 32.5%, p = 0.22.

In the conservative group, four patients complained of persistent hip pain, two of whom were treated with hip arthroscopy to manage associated labral tears, one was treated with cortisone injection and one was managed conservatively. In the surgical group, four patients had lateral femoral cutaneous nerve loss of sensation, which remained permanent in two patients but did not interfere with function, whereas resolved spontaneously in two patients in 18-months.1 hematoma occurred in the post-operative course in one patient, and one patient had delayed wound healing.

4. Discussion

Proximal rectus femoris avulsions, being uncommon injuries even in sporting individuals, are challenging injuries to treat. The rectus femoris muscle, being the only muscle within the quadriceps group, which acts across the hip and the knee joint, is more susceptible to injury through overloading. Not surprisingly, injuries most commonly occur at the quadriceps musculotendinous junction level, while proximal avulsion injuries of the rectus femoris are rare ^(2,4,25). Till date, no evidence-based guidelines exist for the ideal treatment method in high-demand patients. The aim of his systematic review with meta-analysis was therefore to encapsulate the existing evidence in the literature.

These injuries are commonly encountered in kicking athletes during a forceful contraction of the quadriceps from the hip-extended/knee-flexed position to the hip-flexed/knee extended position. A block to the kicking motion (e.g., another player’s foot on the ball) can result in rectus femoris avulsion. Gamradt et al. observed this injury in 9 non-kicking athletes as well and proposed that a sudden deceleration during sprinting could be a mechanism of injury in the non-kicking player.⁸

No studies have discussed the gold standard for diagnosis in such injuries, but in general, it is believed that MRI has higher sensitivity than ultrasonography in diagnosing musculotendinous pathologies ^26,27.In our systematic review, most of the studies performed MRI on suspected patients to definitely diagnose the injury. Moreover, it is also recommended by Ueblacker et al. to measure the amount of retraction of the avulsed tendon.²¹ They postulated that partial avulsions or tears of only one of the tendons, with no or minimal retraction may heal without surgery, while conservative treatment for total avulsions with significant retraction(more than 20 mm) most probably will not lead to anatomical healing which may affect the muscle strength and function. Sinikumpu also recommended operating on bony avulsions if displacement was greater than 20mm²³. Foote et al. and Hosalkar et al. recommended that in patients treated conservatively for PRFAs and with persistent hip symptoms, MRA might be beneficial to rule any intra-articular associated injuries like labral tears ^(19,28). Hosalkar et al. also described a new lesion, HALTAR-the Hip Antero-superior Labral Tear with Avulsion of Rectus femoris, the equivalent of SLAP tear lesion in the shoulder. In his study of nine patients treated conservatively for PRFAs, Foote et al. observed that labral tears were found in seven patients, thus indicating high association of intra-articular pathologies along with PRFAs, particularly of the reflected head.¹⁹ Two out of these nine patients eventually had to undergo surgery for significant refractory pain and impingement.

Recapitulating the outcomes of conservative and operative treatment for PRFAs, the main finding of this study was that excellent outcome and successful return to sport is well achieved by both, surgical as well as conservative treatments, with comparable complication rates among both treatment methods. The difference however lies in the mean time to return to play (112.6 days-surgical v/s 69.2 days-conservative), thus indicating that conservative treatment allows for a faster recovery to the same pre-injury level of sporting activity. However, it must be noted that the mean CMS of conservative management studies is 33.3 while that of surgical management studies is 51.8. Hence the conservative management studies (n = 3) are of lower quality with level IV evidence. Moreover, the study done by Gamradt does not mention the amount of retraction in most of the cases, which may be a significant factor to achieve anatomical healing and optimal function of the avulsed tendon.⁸

Regarding the surgical technique, it is not possible to define a reference technique, as there are no studies comparing two different techniques with matched or randomised groups. However, 72.2% utilized suture anchors to repair the avulsed tendon to the site of origin^{7, 17, 18, 21, 23.} Sonnery-Cottet et al., in his series of five professional soccer players who were diagnosed with avulsions of both the heads of rectus femoris, advocated excision of both the tendon heads and suturing the remnant muscle to the surrounding muscle in a side-to-side fashion.²² Garcia is the only author to have proposed a complementary local infiltration of PRP intraoperatively.¹⁸ However, it should be interpreted with caution, as use of PRP in skeletal muscle is controversial.²⁹

An important prognostic factor was the time to diagnosis and surgery, with a benefit to early management. The mean time to return to play for patients operated for acute PRFAs was 112.6 days as compared to 204.6 days for patients operated for chronic avulsions. Although the number of players who returned to the pre-injury level of activity are similar, the difference in time to return to sports is remarkable, highlighting the importance of early management. For conservative treatment, early diagnosis and rehabilitation would limit residual pain and complications in the medium term, promoting a quick recovery, mainly by preventing the development of muscle fibrosis.

With regards to complications, the main risk of surgical treatment was involvement of the lateral femoral cutaneous nerve (7.4%) with 50% of them resolving spontaneously, and the remaining 50% had a permanent loss of sensation in the supplied region, which did not interfere with function. Importantly, none of the patients had re-ruptures or residual pain after the surgery in the mean follow-up from 18.2 months to 34 months. In contrast, conservative management was associated with residual pain in 13.7% patients with 50% of them needing surgery for treatment of the persistent hip pain. A few second-line surgical techniques have been proposed, but primarily MRA should be done to rule out an intra-articular cause as advocated by Foote et al.¹⁹ If there are no intra-articular pathologies, the surgical technique of primary resection of fibrosis and avulsed tendon heads and suturing of remnant muscle, as suggested by Sonnery-Cottet et al., may be a good option to allow faster recovery.²²

In conclusion, after the systematic review of literature, we propose the following management plan for management of PRFAs (Fig. 8).

Fig. 8.

Management plan proposed for Proximal Rectus Femoris Avulsions.

This study has the following limitations. As with all systematic reviews, the quality of the meta-analyses is based on the quality of the studies analysed. All the nine studies included were of Level 4 evidence and had low to moderate methodological quality with varying heterogenity. Although, prospective, randomized trials would be more suitable to assess the outcomes, due to the infrequency of proximal rectus femoris avulsions, the studies are yet limited to retrospective analyses with small sample size.As a result, the outcomes of this study can serve as the basis for weak to moderate recommendations^30,31. However, to our knowledge, this proportional meta-analysis study summarizes the largest number of proximal rectus femoris avulsion injuries ever reported in the literature, and can help surgeons, physicians and health professional in provisional decision making after discussion with the patient.

5. 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.

What is already known?

• •Rectus femoris is an important muscle in certain sports involving kicking and running.
• •It is an uncommon injury with significant consequences if misdiagnosed or untreated, especially in elite athletes.
• •Treatment options can be conservative or operative; it is unclear which treatment strategy is best in terms of outcome and return to sports.

What are the new findings?

• •There is a lack of higher quality studies comparing conservative and operative treatments for PRFAs.
• •Both conservative and operative treatment provide excellent outcomes in proximal rectus femoris avulsions, with similar rates of return to sports and incidence of complications.
• •There is no gold standard technique to repair the avulsed tendon; however, suture anchors are most commonly used.
• •Early diagnosis and management is an important prognostic factor in determining the outcomes and time to return to sport.

Competing interests-None.

Contributorship- SD: study design; data collection and data analysis; quality rating and statistical analysis; writing of the manuscript. RK and AC: study design; supervision of data collection and analysis; reviewing the manuscript.

Funding info

None.

Ethical approval information

Not required.

Data sharing statement

All available data can be obtained by contacting the corresponding author.’

Legends

PRFA

Proximal Rectus Femoris Avulsions

CMS

Coleman Methodology Score

AIIS

Anterior Inferior Iliac Spine

MRI

Magnetic Resonance Imaging

PRF

Proximal Rectus Femoris

PRISMA

Preferred Reporting Items for Systematic Reviews and Meta-analyses

RCT

Randomised Controlled Trial

MRI

Magnetic Resonance Imaging

MRA

Magnetic Resonance Angiography

NSAIDs

Non Steroidal Anti-Inflammatory Drugs

NFL

National Football League

PRGF

Platelet Rich Growth Factor

US

Ultrasound

WOMAC

Western Ontario and McMaster Universities Arthritis Index

LEFS

Lower Extremity Functional Scale

CI

Confidence Interval

HALTAR

Hip Antero-superior Labral Tear with Avulsion of Rectus femoris

SLAP

Superior Labral Tear from Anterior to Posterior

PRP

Platelet Rich Plasma