Table II.

Results and complications

Study Authors (year)	Results and conclusions	Recurrence/complications
Ilizaliturri et al. [2005] [14]	No snapping symptoms were present in any patient after surgery of at last follow up.	None
Flanum et al. [2007] [15]	None of the patients experienced recurrence of their snapping or pain	At 1-year follow-up 2 patients noted occasional slight pain in their hips.
Anderson and Keene [2008] [16]	All patients had resolution of snapping and all returned to sport on average 9 months after surgery	Six patients still experienced pain
Ilizaliturri et al. [2009] [17]	No differences were found between the 2 groups	None
Contreras et al. [2010] [18]	All patients returned to original or better level of function shortly after operation. All had maximum strength of hip flexion, extension, abduction, and adduction	Two patients had no improvement in pain despite resolution of the snapping. No patient had any post-operative complications.
Fabricant et al. [2012] [20]	The purpose of this study was to identify the functional outcomes of high version compared to low/normal version.	Patients with increased femoral anteversion may be at greater risk for inferior clinical outcomes after arthroscopic lengthening. No intraoperative or perioperative complications.
Hain et al. [2013] [21]	The majority of post-operative symptomatic patients have atrophy of the iliacus and psoas muscles and distortion and disruption of the iliopsoas tendon.
Garala et al. [2014] [22]	Ten patients reported pain relief after their tenotomy and 5 patients reported no change in pain. For those patients with only temporary relief from injection, psoas tenotomy can provide good long-term pain relief.	In both groups of patients, exercise was the most affected category identified. Symptoms that patients complained of at 49 months after the tenotomy included pain (26%), stiffness (13%), instability (20%), decreased range of motion (20%) and snapping sensation (33%).
Ilizaliturri et al. [2014] [23]	Every patient in both groups had an improvement in WOMAC score.	One patient in group 2 presented with recurrence of snapping that required surgical intervention.
El Bitar et al. [2014] [24]	Statistically significant improvement in all PROs 81.8% good/excellent satisfaction and 81.8% resolution of painful snapping.	Revision surgery (n = 8; labral retear [n = 6], stiffness [n = 1], heterotopic ossification [n =1]), superficial wound infection (n = 1), perigenital numbness (n = 1)
Nelson and Keene [2014] [12]	An arthroscopic release of the iliopsoas tendon at the level of the labrum was effective for alleviating hip pain from labral lesions caused by impingement of the tendon in 23 of 30 patients (77%).	Recurrent snapping (n = 3) requiring iliopsoas bursa injections.Development of avascular necrosis (n = 1)Progression of degenerative joint disease (n = 1)Chronic greater trochanteric bursitis (n = 2)
Hwang et al. [2015] [5]	Snapping sound disappeared in 24 out of 25. Improvement in Harris Hip Score Values	Revision surgery (n = 1) for painful snapping
Brandenburg et al. [2016] [26]	In the release group, the iliopsoas muscle of the surgical limb was significantly smaller and weaker in the seated position (both P<001) than the contralateral limb	Iliopsoas atrophy with 25% volume loss and a 19% reduction in seated hip flexion strength in (25.3% of IFL group)
Mardones et al. [2016] [27]	Statistically significant improvement in patients functional scores (mHHS and Vail Sport Test)	Recurrence of pain 1-year post-operatively (n = 2)
Walczak et al. [2017] [9]	A majority of patients (89%) developed iliopsoas (IP) muscle atrophy after labral level IP tenotomies. The lesser trochanteric IP tenotomies did not develop atrophy of the gluteus maxims (n = 1) and vastus lateralis muscles, have chronic IP tendon disruption (n = 2), or develop the severity of IP atrophy (n = 3).	Iliopsoas tendon tear (n = 2), gluteal tendon tear (n = 1), lateral femoral cutaneous nerve injury (n = 1)
Hartigan et al. [2018] [28]	Patients with an LCEA of less than 25 and associated painful iliopsoas snapping can be treated by central-compartment IFL and have high satisfaction, improvement in PROs, and improved pain scores without significant progression of osteoarthritis.	Revision (n = 4) for traumatic labral retear, no complications
Perets et al. [2018] [6]	All PRO scores demonstrated significant improvements at latest follow-up (P < 0.001). Mean satisfaction was 7.9. No patients converted to arthroplasty. Painful snapping was resolved in 55 athletes (91.7%)	Temporary numbness (n = 1)
Maldonado et al. [2018] [8]	The IFL group showed comparable results to the control group with respect to PRO improvement.	Revision surgery (n = 17 in IFL group) and (n = 11 in non-IFL group); conversion to THA (n = 4 in IFL group) and (n = 7 in non-IFL group)
Perets et al. [2019] [7]	IFL as part of hip arthroscopy for treatment of FAI and labral tears demonstrated similar favorable improvement, complication rates, and secondary surgeries when compared with a control group that did not undergo IFL	Ten hips (17.5%) required secondary arthroscopy. Three hips (5.3%) required total hip arthroplasty. One case (1.8%) had minor post-operative complications
Meghpara et al. [2020] [4]	Both groups experienced significant improvements from pre-surgery to latest follow-up for all recorded PROs. The IFL group compared favorably with the control group for mHHS (86.0 versus 86.1; P = 0.53), NAHS (83.0 versus 84.7; P = 0.40), and HOSSSS (78.1 versus 76.5; P = 0.87). Additionally, iHOT-12, VAS, patient satisfaction, and rates of achieving the minimal clinically important difference for mHHS, NAHS, and HOS-SSS were similar between groups at the latest follow-up.	Study group (IFL): one hip required revision arthroscopy for labral tear and 2 hips converted to THA. 13 hips will persistent PISControl group (non-IFL) 1 hip required revision arthroscopy because of residual FAI
Maldonado et al. [2021] [8]	All patients in the study group demonstrated statistically significant improvement from pre-operative to latest follow-up in mHHS, NAHS, HOS-SSS, and VAS scores. Fifty-seven (78.1%) patients achieved or exceeded the minimal clinical important difference (MCID) for mHHS. For HOS-SSS 68.1% met or surpassed the MCID.	Study group 2 secondary arthroscopy and 1 total hip arthroplastyControl group 1 secondary arthroscopy and 1 total hip arthroplasty
Matsuda et al. [2021] [10]	Co-afflicted patients treated without tenotomy have similar successful outcomes to patients with primary FAI.	Co-afflicted patients with iliopsoas pathology treated with tenotomy had poorer outcomes compared with controls with FAI without iliopsoas pathology
Jimenez et al. [2022] [5]	89.5% of athletes who attempted to return to sport in IFL were successful. 76.0% of athletes who attempted to return in the non-IFL were successful. e main finding of the present study was that at minimum 5-year follow-up, competitive athletes who underwent primary hip arthroscopy for FAIS and IFL for painful internal snapping hip demonstrated significant improvement in all recorded PROs.	The IFL group underwent 2 revision arthroscopiesThe control group underwent 3 revision arthroscopiesControl group had higher rates of undergoing femorplasties when compared to the IFL group.