Magnetic Resonance Imaging Appearance of the Hip Musculature After Arthroscopic Labral-Level Iliopsoas Tenotomies

Assessment of function and muscle strength after endoscopic iliopsoas tenotomy to treat iliopsoas impingement after total hip arthroplasty

PURPOSE

The objective of this study was to evaluate the functional outcome during follow-up (FU) after endoscopic tenotomy for iliopsoas (IP)-cup impingement and to quantitatively analyze the hip flexion strength.

METHODS

This was a monocentric, retrospective cohort study of a single surgeon series. Functional assessment was based on the modified Harris score, the Oxford score and the visual analog scale score. Strength was measured with a handheld dynamometer in the sitting and lying position.

RESULTS

Thirty-six IP tenotomies for cup impingement were performed between May 2013 and November 2021. Seven (19%) patients were lost to FU. At the time of tenotomy, the mean (standard deviation) age was 62,6 (12,2) and BMI was 26,5 (4,1). The mean FU time after tenotomy to the last FU was 3,6 (0,8) years. All three outcome scores improved from preoperatively to six months postoperatively (p < 0.001). There were no significant change from six months to last FU. The minimal clinically important difference (MCID) of the modified Harris score was set at 25. 20 (69%) patients had values that exceeded the threshold at one month and six months and neutral 19 (65.5%) had values that exceeded the threshold at the last FU. The limp symmetry index concerning hip flexion strength was 63% at 90° and 40% at 30° at the last FU.

CONCLUSION

Most patients significantly improved their outcome scores after endoscopic iliopsoas tenotomy, with results remaining consistently stable over time. Despite a significant loss in hip flexion strength, the majority of patients did not report any impairment of their quality of life.

STUDY DESIGN

Level III, Retrospective cohort study.

The Iliopsoas: Anatomy, Clinical Evaluation, and Its Role in Hip Pain in the Athlete: A Scoping Review

Disability due to iliopsoas (IP) pain and dysfunction is underdiagnosed in the athletic population. The IP unit consists of the psoas major and iliacus muscles converging to form the IP tendon and is responsible primarily for hip flexion strength but has a number of secondary contributions such as femoral movement, trunk rotation, core stabilization, and dynamic anterior stability to the hip joint. As the IP passes in front of the anterior acetabulum and labrum, the diagnosis of IP pain may be confused with labral tearing seen on magnetic resonance imaging. This is in addition to the low sensitivity of magnetic resonance imaging to detect IP tendinitis and bursitis. Resisted seated hip flexion as well as direct palpation of the IP tendon and muscle belly are useful to assess function and help determine whether the IP may be the source of pain, which is common in athletes. Both biomechanical and clinical investigations have demonstrated the role of IP as an anterior hip stabilizer. Patients with signs of hip microinstability, developmental dysplasia of the hip, and increased femoral anteversion are at risk of IP pain and poor outcomes after IP lengthening, highlighting the importance of the IP in providing dynamic anterior hip stability.

The role of iliopsoas fractional lengthening in hip arthroscopy: a systematic review

Arthroscopic iliopsoas fractional lengthening (IFL) is a surgical option for the treatment of internal snapping hip syndrome (ISHS) after failing conservative management. Systematic review. A search of PubMed central, National Library of Medicine (MEDLINE) and Scopus databases were performed by two individuals from the date of inception to April 2023. Inclusion criteria were ISHS treated with arthroscopy. Sample size, patient-reported outcomes and complications were recorded for 24 selected papers. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and registered on PROSPERO database for systematic reviews (CRD42023427466). Thirteen retrospective case series, ten retrospective comparative studies, and one randomized control trial from 2005 to 2022 were reported on 1021 patients who received an iliopsoas fractional lengthening. The extracted data included patient satisfaction, visual analogue scale, the modified Harris hip score and additional outcome measures. All 24 papers reported statistically significant improvements in post-operative patient-reported outcome measures after primary hip arthroscopy and iliopsoas fractional lengthening. However, none of the comparative studies found a statistical benefit in performing IFL. Existing studies lack conclusive evidence on the benefits of Iliopsoas Fractional Lengthening (IFL), especially for competitive athletes, individuals with Femoroacetabular Impingement (FAI), and borderline hip dysplasia. Some research suggests IFL may be a safe addition to hip arthroscopy for Internal Snapping Hip Syndrome, but more comprehensive investigations are needed. Future studies should distinguish between concurrent procedures and develop methods to determine if the psoas muscle is the source of pain, instead of solely attributing it to the joint.

Imaging changes following surgery for ischiofemoral impingement

Partial resection of the lesser trochanter (LT plasty) has been increasingly recommended to treat ischiofemoral impingement. However, there is a lack of studies on the imaging findings following LT plasty. The purpose of this study was to assess magnetic resonance imaging (MRI) changes on the lesser trochanter and surrounding musculotendinous structures following LT plasty to treat ischiofemoral impingement. Twenty-one patients (21 hips) were studied. The LT length and cross-sectional area of the iliopsoas muscle were measured on MRI before and after surgery. The MRIs were performed on average 11 months (range, 3 to 25 months) after surgery. The mean ±  standard deviation amount of LT resected (difference between pre- and postoperative LT length) was 7.3 mm ±  2.5 mm. The iliopsoas cross-sectional area decreased after the LT plasty in 95% of the hips (20/21) by an average of 35% ± 16%. The reduction in iliopsoas size had no significant correlation with improvement on the modified Harris Hip Score at a mean follow-up of 17 months after surgery (r = -0.13, P = 0.58). The iliopsoas muscle size decreased on average 35% following endoscopic LT plasty. The decrease was not correlated with midterm functional outcomes.

Multiple iliopsoas tendons: a cadaveric study and treatment implications for internal snapping hip syndrome

PURPOSE

This cadaveric study aimed at describing the anatomical variations of the iliopsoas complex.

METHODS

The iliopsoas complex was dissected unilaterally in 28 formalin-embalmed cadavers-13 males and 15 females with a mean age of 85.6 years. The number, courses and widths of the iliacus and psoas major tendons were determined. Patients with previous hip surgery were excluded. The following measurements were taken from the mid-inguinal point: the distance to the point of union of the psoas major and iliacus tendon; and the distance to the most distal insertion of iliopsoas.

RESULTS

The presence of single, double and triple tendon insertions of iliopsoas were found in 12, 12 and 4 of the 28 specimens, respectively. When present, double and triple tendons inserted separately onto the lesser trochanter. The average length of the iliopsoas tendon from the mid-inguinal point to the most distal attachment at the lesser trochanter was 122.3 ± 13.0 mm. The iliacus muscle bulk merged with psoas major at an average distance of 24.9 ± 17.9 mm proximal to the mid-inguinal point. In all cases, the lateral-most fibres of iliacus yielded a non-tendinous, muscular insertion on to the anterior surface of the lesser trochanter and the femoral shaft, rather than joining onto the main iliopsoas tendon(s). The average total width of the psoas major tendon decreased with an increasing number of tendons: 14.6 ± 2.2 mm (single tendon), 8.2 ± 3.0 mm (2 tendons present) and 5.9 ± 1.1 mm (3 tendons present) (P < 0.001).

CONCLUSIONS

The results of this study suggest that multiple tendinous insertions of iliopsoas are present as an anatomical variant in more than 50% of the population. The non-tendinous muscular insertion of the iliopsoas on to the anterior surface of the lesser trochanter and femoral shaft found represents a novel anatomical variant not previously described.

LEVEL OF EVIDENCE

Level V.

Arthroscopic iliopsoas tenotomies: a systematic review of surgical technique and outcomes

PURPOSE

To evaluate the technique, results and complications of arthroscopic iliopsoas tenotomies either on native hips or total hip arthroplasty (THA).

METHODS

A systematic review was performed using 3 databases: PubMed, EMBASE and the Cochrane library from January 2000 to December 2018 in accordance with the PRISMA procedure. The literature search, data extraction and quality assessment were conducted by 2 independent reviewers. Surgical technique, clinical outcomes, recurrences and complication rate were evaluated.

RESULTS

Out of 115 articles reviewed, 20 articles concerned native hips and 8 articles THA. 3 levels of release were described. For native hips, the recurrence rate was higher for central compartment than peripheral or lesser trochanter releases. Complication rates were similar for hip arthroscopy but remained low in all series. Loss of strength was evaluated mainly using the MRC muscle scale. Most studies noted strength recovery. MRI analysis of muscle atrophy was greater for lesser trochanter than for central compartment release but unrelated to loss of strength. The complication rate was low for tenotomy after THA, heterotopic ossification being the most common complication.

CONCLUSIONS

Central compartment releases lead to the highest rate of recurrence due to incomplete release. Peripheral releases have a potential risk of vascular injury. The lesser trochanteric approach has the disadvantage of not having direct access to the joint. The main difficulty with THA lies in the diagnosis of cup/iliopsoas impingement. Diagnostic tests with infiltration should be made before iliopsoas release to prevent its failure. Cup protrusion of over 8mm is a potential indication for acetabular revision.

Iliopsoas Tenotomy During Hip Arthroscopy: A Systematic Review of Postoperative Outcomes

BACKGROUND

Arthroscopic iliopsoas tendon release is a surgical treatment option for painful snapping hips, although it has been associated with controversy surrounding potential complications including decreased hip flexion strength, iatrogenic hip instability, and iliopsoas atrophy.

PURPOSE

To systematically assess the efficacy and safety of arthroscopic iliopsoas tenotomy during hip arthroscopic surgery as an intervention for painful snapping hips.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A total of 3 online databases (Embase, PubMed, and MEDLINE) were searched from database inception until September 2019 for studies investigating iliopsoas tenotomy during hip arthroscopic surgery. Studies were screened by 2 reviewers independently and in duplicate, and studies investigating arthroscopic iliopsoas tendon release were included. Demographic data as well as data on treatment success, functional outcome scores, and radiological outcomes were recorded. A risk of bias assessment was performed for all included studies.

RESULTS

Overall, 21 studies were identified with a total of 824 patients (875 hips). These patients were 82.5% female (680/824), with a mean age of 28.1 years (range, 12-62 years) and mean follow-up of 32.1 months (range, 3-73 months). Arthroscopic iliopsoas tenotomy was performed at the level of the labrum in 811 hips (92.7%) or the lesser trochanter in 64 hips (7.3%). The overall reported success rate of the procedure in resolving snapping hips was 93.0% (266/286), and all studies reported an improvement in functional outcome scores. Only 6 studies (93 hips) discussed postoperative hip flexion strength, with complete recovery of strength reported in 4 studies (47 hips) and mild decreases reported in the other 2 studies (46 hips). Iliopsoas atrophy was evaluated radiologically (3 studies; 66 hips) and was found postoperatively in 92.4% (61/66) of hips. No major complications were reported.

CONCLUSION

Arthroscopic release of the iliopsoas tendon was effective in alleviating pain and persistent clicking associated with a snapping hip. Although patients demonstrated some early postoperative weakness and iliopsoas atrophy on radiological imaging, the results from studies to date showed satisfactory clinical function and return to sports/activities. High-quality comparative studies are needed to further assess arthroscopic iliopsoas tendon release to determine the optimal technique and location of tendon release.

Microinstability of the hip: a systematic review of the imaging findings

OBJECTIVES

To undertake a systematic review of the morphologic features associated with hip microinstability and determine whether there are suggestive or diagnostic imaging findings.

METHODS

Four electronic databases were searched up to September 2019 to identify original research reporting morphologic features in individuals with either a clinical diagnosis of hip microinstability (instability without overt subluxation/dislocation) or those with symptomatic laxity demonstrated on imaging (increased femoral head translation/distraction or capsular volume). Studies focussing on individuals with pre-existing hip conditions (including definite dysplasia (lateral centre edge angle < 20°), significant trauma, previous dislocation or surgery were excluded. Methodological quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

RESULTS

Twenty-two studies met inclusion criteria (clinical diagnosis of microinstability n = 15 and demonstration of laxity n = 7). Imaging information gathered from the studies includes radiographs (n = 14), MRI (n = 6), MR arthrography (n = 4), CT (n = 1) and intraoperative examination. Most studies exhibited design features associated with an overall high or unclear risk of bias. Some dysplastic features are associated with microinstability or laxity reference measures; however, microinstability is frequently diagnosed in those with a lateral centre edge angle > 25°. Other associated imaging findings reported include impingement morphology, anterior labral tearing, femoral head chondral injury, ligamentum teres tears and capsular attenuation.

CONCLUSIONS

The current literature does not provide strong evidence for imaging features diagnostic of microinstability. In the appropriate clinical context, dysplastic morphology, anterior labral tears and ligamentum teres tears may be suggestive of this condition although further research is needed to confirm this.

PROSPERO REGISTRATION

CRD42019122406.

Iliopsoas Release in Hip Arthroscopy: Assessment of Muscle Atrophy

Iliopsoas release is a common procedure for coxa saltans interna of the hip. The possible sequelae from this surgery have not been well studied. The purpose of this study was to determine postoperative atrophy and morphology of the cut tendon. This retrospective review included patients who underwent arthroscopic iliopsoas release and had magnetic resonance imaging of the ipsilateral hip before and after surgical intervention. Cross-sectional area measurements were obtained of the iliopsoas muscle at the level of the distal anterior inferior iliac spine as well as at the L5 vertebral pedicle in patients who had imaging that included the lower lumbar spine. Patient-reported outcomes included the modified Harris Hip Score (mHHS) and the Hip Outcome Score subscales for activities of daily living (HOS ADL) and sport (HOS Sport). A total of 44 patients met inclusion criteria for this study; 26 patients had additional advanced imaging that included the lumbar spine. The cross-sectional area of the iliopsoas at the level of the anterior inferior iliac spine decreased postoperatively by a mean of 191.4 mm²;, this difference was statistically significant (P<.0001). Mean area at the L5 pedicle was 628.9 mm² on the released side and 1216.2 mm² on the nonoperative side (P<.05). Mean Goutallier-Fuchs score of the released iliopsoas at the L5 pedicle was 1.3 (SD, 0.7). Mean mHHS, HOS ADL, and HOS Sport scores for patients at least 1 year postoperatively were 51, 56, and 42, respectively. [Orthopedics. 2020;43(3):e171-e176.].

Extra-articular hip impingement: clinical presentation, radiographic findings and surgical treatment outcomes

Femoroacetabular impingement syndrome is classically thought of as either a cam or pincer deformity causing abnormal bony contact resulting in labral pathology. However, alternate patterns of hip impingement can occur, but tend to be less commonly recognized or studied. Collectively termed 'extra-articular impingement', four subgroups of impingement can contribute to non-arthritic hip pain and disability: iliopsoas impingement, subspine impingement, ischiofemoral impingement and trochanteric-pelvic impingement. The purpose of this review article is to highlight the pertinent points to aid in proper clinical and radiographic evaluation to allow appropriate diagnosis. Additionally, a review of potential surgical treatment options and resultant outcomes will also be provided.

Does Iliopsoas Lengthening Adversely Affect Clinical Outcomes After Hip Arthroscopy? A Multicenter Comparative Study

BACKGROUND

Iliopsoas fractional lengthening (IFL) continues to be a controversial procedure in hip arthroscopy.

HYPOTHESIS

Patients who underwent arthroscopic surgery for femoroacetabular impingement (FAI) and a labral tear either with or without IFL would experience favorable outcomes, and there would be no difference in postoperative patient-reported outcomes (PROs) between the 2 groups at minimum 2-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from July 2009 and April 2015 were retrospectively reviewed. Patients were eligible if they had hip arthroscopy for both FAI and labral tear treatment with IFL and without IFL. IFL was indicated for painful internal snapping. Minimum postoperative follow-up was set to 2 years. The authors calculated the modified Harris Hip Score, International Hip Outcome Tool-12, Hip Outcome Score-Activity of Daily Living Score, Hip Outcome Score-Sports Specific Subscale, Non-Arthritic Hip Score, visual analog scale for pain, patient satisfaction, minimal clinically important difference (MCID), and the percentage of patients who achieved patient acceptable symptomatic state (PASS). Revision surgeries and conversions to total hip arthroplasty (THA) were documented.

RESULTS

351 hips (307 patients) met the necessary inclusion criteria in the IFL cohort, with a mean ± SD follow-up time of 42.5 ± 18.1 months. For the control cohort, 392 hips (354 patients) were included, with a mean ± SD follow-up time of 43.9 ± 19.6 months. Both groups showed significant postoperative improvement in 2-year follow-up PROs. The group with iliopsoas lengthening showed comparable results to the control group with respect to PRO improvement, MCID, PASS, and rates of revision or THA conversion.

CONCLUSION

This comparative cohort study demonstrated that treatment of painful internal snapping syndrome with arthroscopic IFL, in the setting of FAI and a labral tear, is a safe procedure with good short- to mid-term follow-up results and associated improvement in PROs. Patients who underwent IFL showed similar outcomes compared with a control group treated for FAI and labral tear without IFL. In appropriately selected patients, arthroscopic IFL did not adversely affect clinical outcomes compared with patients who did not need IFL.

Editorial Commentary: Caveat Flexor-To Release or Not to Release the Iliopsoas, That Is the Question

In nonarthritic patients with femoroacetabular impingement syndrome, borderline dysplasia, and symptomatic iliopsoas snapping, arthroscopic iliopsoas fractional lengthening carries a significant risk of postarthroscopic instability. The iliopsoas is a dynamic stabilizer of the anterior hip. Thus, although statistically significant and clinically important improvements in hip function have the potential to be achieved with iliopsoas fractional lengthening, surgeons must be supremely confident in their ability to perform a secure capsular plication, labral preservation (not debridement), comprehensive cam correction, avoidance of intra-abdominal fluid extravasation, release of all iliopsoas tendon bands (if bifid or trifid), and ensure that femoral version is normal or low, neck-shaft angle is not excessively valgus, the dysplasia magnitude is no more than mild, and that there is no excessive soft tissue hypermobility. If these goals can be met, then excellent outcomes can be achieved. If not, then an iliopsoas fractional lengthening should not be performed.