Vascular safe zones in hip arthroscopy

Femoral Head Vascularity After Arthroscopic Femoral Osteochondroplasty: An In Vivo Dynamic Contrast-Enhanced MRI Study

Background

A serious concern with surgical procedures around the hip joint is iatrogenic injury of the arterial supply to the femoral head (FH) and consequent development of FH osteonecrosis. Cam-type morphology can extend to the posterosuperior area. Understanding the limit of the posterior superior extension of the femoral osteochondroplasty is paramount to avoid underresection and residual impingement while maintaining FH vascularity.

Purpose/Hypothesis

The aim of this study was to quantify the impact of arthroscopic femoral osteochondroplasty on the FH vascular supply. It was hypothesized that keeping the superior extension of the resection zone anterior to the 12-o'clock position would maintain FH vascularity.

Study Design

Case series; Level of evidence, 4.

Methods

Ten adult patients undergoing arthroscopic femoroacetabular impingement (FAI) surgery were included in the study. Computed tomography (CT) scans were obtained before and after arthroscopic osteochondroplasty to define the extension of resection margins. To quantify FH vascularity, postoperative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was obtained at 2 time points: immediately after surgery and at the 3-month follow-up. Custom MRI analysis software was used to quantify perfusion.

Results

CT scan analysis demonstrated that the superior resection margin was maintained anterior to the 12-o'clock position in half of the patients. The remining 5 patients had a mean posterior extension of 11.4° ± 7.5°. The immediate postoperative DCE-MRI revealed diminished venous outflow in the operative side but no difference in overall FH perfusion. At the 3-month follow-up DCE-MRI, there was no perfusion difference between the operative and nonoperative FHs.

Conclusion

This study provides previously unreported quantitative MRI data on in vivo perfusion of the FH after the commonly performed arthroscopic femoral osteochondroplasty for the treatment of cam-type FAI. Maintaining resection margins anterior to the 12-o'clock position, or even 10° posteriorly, was not observed to impair perfusion to the FH.

Postoperative Musculoskeletal Imaging and Interventions Following Hip Preservation Surgery, Deformity Correction, and Hip Arthroplasty

Total hip arthroplasty and hip preservation surgeries have substantially increased over the past few decades. Musculoskeletal imaging and interventions are cornerstones of comprehensive postoperative care and surveillance in patients undergoing established and more recently introduced hip surgeries. Hence the radiologist's role continues to evolve and expand. A strong understanding of hip joint anatomy and biomechanics, surgical procedures, expected normal postoperative imaging appearances, and postoperative complications ensures accurate imaging interpretation, intervention, and optimal patient care. This article presents surgical principles and procedural details pertinent to postoperative imaging evaluation strategies after common hip surgeries, such as radiography, ultrasonography, computed tomography, and magnetic resonance imaging. We review and illustrate the expected postoperative imaging appearances and complications following chondrolabral repair, acetabuloplasty, osteochondroplasty, periacetabular osteotomy, realigning and derotational femoral osteotomies, and hip arthroplasty.

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.

Posterior Femoral Cam Decompression Through an Arthroscopic Anterior Approach With Pre-Bent Hip Burrs

Hip arthroscopy has been increasingly used to treat labral tears and cam and pincer lesions found in femoroacetabular impingement. Although the classic impingement with cam deformity at the proximal femoral anterolateral quadrant is most common, there has been evidence of cam impingement extension to the anteromedial and posterior quadrants of the proximal femur. Posterior cam decompression carries a theoretical risk of vascular insult and subsequent osteonecrosis, which have led investigators to approach these posterior lesions through an open surgical correction. Recent improvements have led to the development of pre-bent burs that allow for bonier resection flexibility. Here, we report on an arthroscopic posterior cam decompression using the traditional anterior portals and curved hip burs via a figure-of-four positioning technique.

Hip arthroscopy for lateral cam morphology: how important are the vessels?

The purpose of this narrative review is to identify the anatomy and relevant blood supply to the femoral head as it pertains to hip arthroscopy and lateral cam morphology. The primary blood supply to the femoral head is the lateral ascending superior retinacular vessels, which are terminal branches of the medial femoral circumflex artery. These vessels penetrate the femoral head at the posterolateral head–neck junction. Surgeons performing posterolateral femoral osteoplasty must respect this vasculature to avoid iatrogenic avascular necrosis (AVN). Avoidance of excessive traction, avoidance of distal posterolateral capsulotomy and avoidance of disruption of the superior retinacular vessels should keep the risk for AVN low. Hip extension, internal rotation and distraction are useful in hip arthroscopy to better visualize lateral/posterolateral cam morphology to facilitate an accurate comprehensive cam correction and avoid vascular disruption.

Vascular Supply to the Femoral Head in Patients With Healed Slipped Capital Femoral Epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is one of the most common hip disorders. The vascularity of the lateral epiphyseal vessels supplying the femoral head in patients with healed SCFE has not been well defined. The purpose of this study was to characterize the location and number of lateral epiphyseal vessels in young adults with healed SCFE.

METHODS

This was a retrospective study of 17 patients (18 hips) with a diagnosis of SCFE and a matched control group of 17 patients (17 hips) with developmental dysplasia of the hip. All patients underwent high-resolution contrast-enhanced magnetic resonance imaging to visualize the path of the medial femoral circumflex artery and the lateral epiphyseal arterial branches supplying the femoral head.

RESULTS

There were 5 unstable SCFEs and 13 stable SCFEs with an average slip angle of 31 degrees. (All patients had been treated with in situ pinning and screw removal). Average age at time of magnetic resonance imaging was 24.5 years (range, 15 to 34 y). The lateral epiphyseal vessels reliably inserted on the posterior-superior aspect of the femoral neck from the superior-anterior to the superior-posterior position in both the SCFE and control groups. An average of 2 (±0.8) retinacular vessels were identified in the SCFE group compared with 5.2 (±0.7) retinacular vessels in the control group (P<0.001).

CONCLUSIONS

In healed SCFE, the lateral epiphyseal vessels reliably insert in the same anatomic region as patients with hip dysplasia; however, the overall number of vessels is significantly lower.

Vascular supply of the femoral head in sheep-Implications for the ovine femoroacetabular impingement model

Sheep hips have a natural non-spherical head similar to a cam-type deformity in human beings. By performing an intertrochanteric varus osteotomy, cam-type femoroacetabular impingement can be induced experimentally. In sheep, the aspherical portion is located superiorly-exactly matching the region where the superior retinacular vessels enter the femoral head-neck junction in human beings. In order to fully exploit the potential of this experimental FAI model, a safe osteochondroplasty of the superior asphericity would need to be done without the risk of avascular necrosis. The aim of this study was to describe the vascular anatomy of the femoral head in sheep from the aorta to the retinacular vessels in order to perform safe femoral osteochondroplasty of the superior femoral asphericity in sheep. Sixty-two ovine hips were analyzed using CT angiography (30 hips), post mortem intravascular latex injection (6 hips), vascular corrosion casting (6 hips), and analysis of the distribution of vascular foramina around the femoral head-neck junction in macerated ovine femora (20 hips). The ovine femoral head receives its blood supply from anterior retinacular arteries from the lateral femoral circumflex artery, and from posterior retinacular arteries from the medial femoral circumflex artery. The superior aspherical portion is free of vessels. Detailed knowledge about vascular anatomy of sheep hips is of clinical significance since it allows to perform osteochondroplasty of the superior aspherical portion in the experimental ovine FAI model safely without the risk of osteonecrosis. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2340-2348, 2018.

Anatomic implications of lesser trochanterplasty

Objective

The aim of this study was to measure the area of iliopsoas tendon attachment and the distance of sciatic nerve, medial circumflex femoral artery (MCFA) and quadratus muscle to lesser trochanter tip, before and after 5, 10, 15 mm depth excision of lesser trochanter.

Methods

A total 15 hips of 8 adult male cadavers were evaluated. Distances between lesser trochanter tip, sciatic nerve, the lower edge of quadratus muscle and MCFA; length and width of quadratus muscle insertion; area of iliopsoas muscle and quadratus muscle insertion was measured before and after sequential 5,10 and 15 mm depth trochanterplasties using 5 mm wide burr parallel to the posterior cortex.

Results

Each incremental 5 mm depth bone removal led to significant decrease of tendon area (p=0.001) at each stage. Mean decreases of iliopsoas tendon attachment area with incremental 5 mm burring were 22%±10 with 5 mm, 50%±13 with 10 mm, and 76% ±13 with 15 mm of burring.

Conclusion

Up to 15 mm lesser trochanter removal did not result in complete detachment of the iliopsoas tendon. Lesser trochanter tip was detected at least 20 mm away from important anatomic structures including quadratus tendon, sciatic nerve, and the medial circumflex femoral artery.

Quantitative Assessment of Femoral Head Perfusion Following Arthroscopic Femoral Osteochondroplasty: A Cadaveric Study

BACKGROUND

Disruption of the arterial supply to the femoral head, and subsequent development of femoral head osteonecrosis, is of serious concern with intracapsular hip procedures. However, the effect of arthroscopic femoral osteochondroplasty on femoral head perfusion is unknown. We aimed to quantify the effects of both standard and posterosuperior extension of arthroscopic femoral osteochondroplasty on femoral head vascularity. We hypothesized that extension of the superior resection zone posteriorly would negatively affect femoral head perfusion.

METHODS

In 12 cadaveric pelvic specimens, we cannulated the medial femoral circumflex artery (MFCA). One hip per pelvis was randomly selected to be in 1 of 2 experimental groups based on the superior extent of the osteochondroplasty: standard resection (resection anterior to the 12 o'clock [0° of 360°] position) or extended resection (resection extended posterior to the 12 o'clock position). Computed tomography (CT) scans were obtained prior to and following arthroscopic resection to delineate the resection margins. Gadolinium enhancement on magnetic resonance imaging (MRI) was quantified in the femoral head by volumetric analysis using custom software. A polyurethane compound was injected and gross dissection of the vasculature was performed.

RESULTS

Extension of the osteochondroplasty posteriorly (the extended-resection group), to a mean of 41.3° (range, 34° to 47°) posterior to the 12 o'clock position, decreased femoral head perfusion by a mean of 28% (range, 18% to 38%). The standard-resection group demonstrated a mean decrease in femoral head perfusion of 7% (range, 4% to 11%). Correlation analysis demonstrated a significant negative correlation (correlation coefficient, -0.877; p < 0.001; R = 0.747). For every 1° that the superior resection margin extended posteriorly, a corresponding 0.88% decrease in femoral head perfusion was found.

CONCLUSIONS

Femoral head perfusion is almost fully maintained with arthroscopic osteochondroplasty when the superior resection margin is anterior to the 12 o'clock position. Perfusion is also well maintained if the superior resection margin is extended no more than 10° posterior to 12 o'clock. Further posterior extension correlated with greater decreases in femoral head perfusion.

CLINICAL RELEVANCE

Our study provides previously unreported quantitative MRI data on femoral head perfusion following arthroscopic femoral osteochondroplasty for the treatment of cam-type femoroacetabular impingement.

Basic Hip Arthroscopy: Diagnostic Hip Arthroscopy

Hip arthroscopy is increasing in popularity for the diagnosis and management of hip preservation. The basics of hip arthroscopy positioning, fluoroscopic assessment, and portal establishment are reviewed in the first 2 parts of this series. This article is the third installment in which we describe a systematic approach to performing a diagnostic hip arthroscopy. A mastery of diagnostic arthroscopy is necessary for surgeons treating hip disorders.

Isolated Acetabuloplasty and Labral Repair for Combined-Type Femoroacetabular Impingement: Are We Doing Too Much?

PURPOSE

To evaluate patient outcomes after isolated arthroscopic volumetric acetabular osteoplasty and labral repair for the treatment of patients with combined femoroacetabular impingement (FAI) lesions.

METHODS

A review of a prospectively collected registry identified 86 patients (106 hips) with an average age of 38.1 years (range, 17-59 years) with combined-type FAI that underwent isolated acetabular osteoplasty and labral repair. Preoperative α-angle, degree of radiographic degenerative changes, and presence of a crossover sign were recorded. Clinical outcomes were assessed with the modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHOT-12), Hip Outcome Score Sport-Specific Subscale (HOS-SSS), and patient satisfaction score (out of 10) at a minimum 2-year follow-up.

RESULTS

Clinical follow-up was obtained at a mean follow-up of 37.2 months (range, 27.9-79.2 months). Patients with Tönnis grade 0 and I findings had significantly higher mHHS (83.5 vs 71.5, P = .01), HOS-SSS (81.3 vs 59.9, P = .02), and iHOT-12 scores (71.1 vs 58.8, P = .04) compared to patients with Tonnis grade II changes. However, patient satisfaction scores (8.0 vs 7.2, P = .45) were no different. No significant difference was noted between unilateral and bilateral hip patient outcome scores. Patient age and preoperative α-angles did not correlate with any outcome scores (all R² <0.05). There were no cases of revision surgery or progression to arthroplasty.

CONCLUSIONS

Isolated acetabular decompression may adequately address the underlying impingement in combined-type FAI while avoiding the risks associated with femoral-sided decompression. Good to excellent patient-reported outcomes and satisfaction scores were noted with significantly higher scores in patients with minimal arthritic change. Patient age and preoperative α-angle had less effect on postoperative outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Hip arthroscopy complications regarding surgery and early postoperative care: retrospective study and review of literature

PURPOSE

The purpose is to describe the rate of complications in a series of hip arthroscopies performed at our center, as well as perform a systematic review of the current literature in order to compare our outcomes.

METHODS

Two hundred and fifty-eight patients affected of femoroacetabular impingement and treated with hip arthroscopy have been studied. All minor and major complications were studied during the first postsurgery year. Furthermore, a systematic review was performed comparing major and minor complications with our series. Two attending orthopedic surgeons selected the different studies with the same inclusion and exclusion criteria, remaining with 48 studies that have been reviewed and included in the present study.

RESULTS

Mean age was 36.6 years old (SD 17.45), and the ratio men:women was 137:121. The mean complication rate observed was 14.34% (37/258) of global complications. Only three patients showed major complications: femoral neck fracture, septic arthritis and avascular necrosis of the femoral head. Any of these patients had permanent side effects.

CONCLUSIONS

Hip arthroscopy has a low rate of major complications, but a higher number of minor complications that could be avoided with certain preventive measures.

Endoscopic release of internal snapping hip: a review of literature

BACKGROUND

Internal snapping hip is a common clinical condition, characterized by an audible or palpable snap of the medial compartment of the hip. In most cases it is asymptomatic, while in a few patients, mostly in athletes who participate in activities requiring extremes of hip range of motion, the snap may become painful (internal snapping hip syndrome - ISHS).

MATERIALS AND METHODS

This is a review of current literature, focused on the pathogenesis, diagnosis and treatment of ISHS.

CONCLUSION

The pathogenesis of ISHS is multifactorial, and it is traditionally believed to be caused by the tendon snapping over the anterior femoral head or the iliopectineal ridge. Most cases of ISHS resolve with conservative treatment, which includes avoidance of aggravating activities, stretching, and NSAIDs. In recalcitrant cases, surgery may be indicated. Better results have been reported with endoscopic iliopsoas tendon release compared with open techniques, which may be related to the treatment of concomitant intra-articular pathologies. Furthermore, endoscopic treatment showed fewer complications, decreased failure rate and postop erative pain. It is important to remember that in most cases, a multiple iliopsoas tendon may exist, and that the incomplete release of the iliopsoas tendon can be a reason for refractory pain and poor results. Then, even if of not clinical relevance at long term follow-up, patients should be told about the inevitable loss of flexion strength after iliopsoas tenotomy.

LEVEL OF EVIDENCE

II.

Femoral Head Avascular Necrosis Is Not Caused by Arthroscopic Posterolateral Femoroplasty

This study was conducted to identify the risk of avascular necrosis of the femoral head after arthroscopic femoroplasty extending to the posterolateral femoral neck, the source of the primary blood supply to the femoral head. Cam lesions of femoroacetabular impingement are typically anterior along the junction of the femoral head and neck. However, anatomic variations can involve the posterolateral vascular region of the femoral head and neck. Femoroplasty involving this vascular region can lead to injury to the blood supply to the femoral head, with subsequent avascular necrosis. If the posterolateral portion of the cam lesion is preserved, persistent femoroacetabular impingement may occur. A retrospective review identified 112 patients who underwent arthroscopic femoroplasty for femoroacetabular impingement over a 2-year period. Of these patients, 14 had femoroplasty that extended to the posterolateral femoral head. Of this group, 5 had undergone magnetic resonance imaging (MRI) after femoroplasty and the other 9 were contacted to undergo MRI of the hip to evaluate for avascular necrosis. A radiologist and the senior author evaluated all MRI scans specifically for avascular necrosis of the femoral head. All procedures were performed by the senior author. Mean age of the 14 patients (8 women and 6 men) with femoroplasty that extended into the posterolateral vascular region of the femoral head was 44 years (range, 23-69 years). All 14 patients underwent MRI evaluation of the affected hip a mean of 25 months (range, 7-44 months) after femoroplasty. No MRI scans showed evidence of avascular necrosis of the femoral head. Femoroplasty of the posterolateral vascular region of the femoral head is not associated with avascular necrosis. Patients with femoroacetabular impingement and a cam lesion extending to the posterolateral femoral head can undergo femoroplasty of this region without the development of avascular necrosis. [Orthopedics. 2016; 39(3):177-180.].

Capsular Management in Hip Arthroscopy: An Anatomic, Biomechanical, and Technical Review

Hip arthroscopy has become an increasingly utilized surgical technique for the treatment of the young, active patients with hip pain. The clinical outcomes of hip arthroscopy in this patient population have been largely successful; however, there is increasing interest in the contribution of hip capsule in postoperative clinical and functional outcomes. The structure and function of the normal hip capsule will be reviewed. Capsular contributions to hip stability will be discussed in the setting of hip arthroscopy with an emphasis on diagnosis-based considerations. Lastly, clinical outcomes following hip arthroscopy will be discussed as they relate to capsular management.

Arthroscopic Treatment of Symptomatic Internal Snapping Hip with Combined Pathologies

Background

Arthroscopic iliopsoas tendon release was introduced in 2000. The purpose of this study was to evaluate clinical outcomes of arthroscopic iliopsoas tendon release for painful internal snapping hip with concomitant hip pathologies.

Methods

Between January 2009 and December 2011, we performed arthroscopic iliopsoas tendon release and related surgeries in 25 patients (20 men and 5 women; mean age, 32 years; range, 17 to 53 years) with combined intraarticular hip pathologies. The patients were followed for a minimum of 2 years postoperatively. Clinical and radiological evaluations were performed.

Results

Snapping sounds had disappeared by the 2-year follow-up in 24 of the 25 patients. All patients who had presented with loss of flexion strength postoperatively showed recovery at postoperative week 6 to 10. Harris hip score improved from 65 points (range, 46 to 86 points) preoperatively to 84 points (range, 67 to 98 points) postoperatively (p < 0.001). Seven hips (28%) had an excellent score, 15 hips (60%) a good score, 2 hips (8%) a fair score, and one hip (4%) a poor score (p < 0.001). The Tonnis grade of osteoarthritis did not change in any of the patients at the last follow-up.

Conclusions

Patients with painful internal snapping hip have combined hip pathologies. Therefore, the surgeon should keep in mind that painful internal snapping hips are frequently combined with concomitant intraarticular pathologies.

An arthroscopic safety zone for the medial compartment of the hip joint

The purpose of this study was to investigate the safety zone without any neurovascular injury to the medial compartment of hip joint through an anatomical method and describe the relationship of the extra-articular anatomic structures from the surface of the hip joint. Thirty-two fresh specimens from 17 adult Korean cadavers (8 males and 9 females, age range 54-79 years at death) were used for this study. For the measurements, the most superolateral point of the pubic symphysis (PS) and prominent point of the anterior superior iliac spine (ASIS) were identified before dissection. The line connecting the PS and ASIS was defined as a reference line and the PS was a starting point for measurements. All 19 variables measured in this study were related to the femoral head, neck, and surrounding neurovascular structures. The variables were measured according to the x- and y-coordinates in relation to the reference line. The femoral head was generally located 39.5-71.0 mm on the x-coordinate and located 33.5-34.6 mm on the y-coordinate. The junction of the femoral neck and body was located at 52.8 mm on the x-coordinate, and 65.3 mm on the y-coordinate. The junction of the femoral head and neck was located at 47.1 mm on the x-coordinate, and 51.4 mm on the y-coordinate. The location of the medial compartment of the hip joint was located from 38.0 to 43.0 % on the x-coordinate and located from 5.1 to 6.5 cm. These results of this study provide detailed anatomy for arthroscopic hip surgeons.

Variability in locations of hip neurovascular structures and their proximity to hip arthroscopic portals

PURPOSE

To measure the distances of pertinent neurovascular structures from bony landmarks used during hip arthroscopy and compare them among different demographic groups.

METHODS

The distances from neurovascular structures to bony landmarks often used during hip arthroscopy were measured on magnetic resonance images of the hip in 100 patients. The structures studied include the lateral femoral cutaneous nerve (LFCN), sciatic nerve, femoral nerve, and femoral artery. These distances were then compared across different demographic groups, and statistical analysis was performed.

RESULTS

The mean anteroposterior (AP) distance from the tip of the greater trochanter to the sciatic nerve was 10.32 mm (range, 0 to 23.8 mm). At the level of the superior tip of the greater trochanter, the mean distances from the anterior superior iliac spine reference line to the LFCN, femoral nerve, and femoral artery were 6.37 mm (range, -9.8 to 35.9 mm) for medial-lateral, 23.24 mm (range, 3.4 to 67.0 mm) for AP, and 26.34 mm (range, 7.3 to 65.5 mm) for AP, respectively. We found significant differences in distances for the LFCN, femoral nerve, and femoral artery for weight (P = .003, P = .041, and P = .004, respectively) and body mass index (P = .003, P = .010, and P = .003, respectively), as well as for the LFCN between whites and Hispanics (P = .032). There were also significant differences for the femoral nerve vector between African Americans and whites (P = .04), as well as between African Americans and Hispanics (P = .04).

CONCLUSIONS

We found the LFCN to be the most at-risk neurovascular structure with hip arthroscopy portal placement. This study also showed that there is wide variability in the locations of pertinent neurovascular structures across different demographic groups, including weight, body mass index, and race or ethnicity.

CLINICAL RELEVANCE

Portal placement during hip arthroscopy carries a risk of neurovascular injury, particularly to the LFCN. The clinician should be aware of the variability in structure location with different patient demographic characteristics.

Hip arthroscopy for challenging deformities: posterior cam decompression

Since the classic description of cam femoroacetabular impingement occurring in the anterolateral quadrant of the proximal femur, there has been growing evidence of cam impingement extending outside of this region. Although anteromedial cam decompression may be performed, posterior cam decompression is at higher theoretic risk of vascular embarrassment with osteonecrosis and/or tensile failure with fracture, leading some investigators to believe that these major deformities require open surgical correction. We present a less invasive method of arthroscopic posterior cam decompression using the modified midanterior portal while avoiding the posterolateral vasculature of the proximal femur.

Accessibility of extra-articular pathologies of iliopsoas tendon and bursitis of greater trochanter in hip arthroscopy

PURPOSE

Different pathologies leading to psoas tendon pain and chronic bursitis of the greater trochanter are well known. The purpose of the study was to underline the accessibility of the psoas tendon at lesser trochanter, reproduce the results and measure the distances to anatomical landmarks.

METHODS

Twelve hips of six human cadavers underwent hip arthroscopy. The accessibility of the iliopsoas tendon at the lesser trochanter and the bursa at the greater trochanter was documented with the camera. In addition to the usual access portals, alternative ventral ports were analysed concerning accessibility of the lesser trochanter. Afterwards, arthroscopy needles were placed along the extra-articular portals followed by dissection. The distances of the portals in relation to important anatomical landmarks were analysed.

RESULTS

The accessibility to the iliopsoas tendon at the lesser trochanter and to the bursa at the greater trochanter throughout the conventional portals was reproducible. Sufficient distances to the important anatomical landmarks could be shown. The mean distance of the distal ventro-lateral and the wide distal ventro-lateral portal to the nervous cutaneous femoris lateralis was 26.8 ± 5.4 mm and 32.2 ± 3.9 mm. The mean distance from the more ventral located portals to the nervous arteria and vena femoralis was 28.3 ± 2.1 mm.

CONCLUSION

This is the first study known to us that describes in detail the accessibility of the extra-articular structures underlined by anatomical preparation. In addition, it was demonstrated that a more ventrally located portal had sufficient distance to the important neurovascular structures of the ventral femur and can also be used in addendum if necessary.

Predictors of hip arthroscopy outcomes for labral tears at minimum 2-year follow-up: the influence of age and arthritis

PURPOSE

The purpose of this study was to perform a retrospective case-control outcome analysis at a minimum 2-year follow-up using a validated hip arthroscopy outcome measure to determine whether arthritis or age is predictive of outcomes after hip arthroscopy for labral pathology.

METHODS

We identified 176 consecutive patients undergoing hip arthroscopy for labral tears performed between 2001 and 2009 to complete the Modified Harris Hip Score (MHHS) and Hip Outcome Score questionnaires. Patients who underwent additional surgeries or reported an MHHS of less than 80 were compared with the control group of patients who achieved good to excellent surgical results on the MHHS (>80) to calculate odds ratios with 95% confidence intervals by use of the independent variables of patient age of 40 years or older and age below 40 years and the presence of grade 4 Outerbridge changes found at arthroscopy.

RESULTS

Of 176 patients, 125 (71%) were contacted: 27 patients had undergone additional surgery in the follow-up period, and 98 completed questionnaires. The mean patient age at surgery was 40.9 years (range, 17.3 to 62.8 years) at a mean follow-up of 4.3 years (range, 2 to 10.4 years). Of 98 respondents, 71 (72%) obtained a good to excellent surgical outcome, with 84% reporting satisfaction. The presence of osteoarthritic changes at the time of arthroscopy was predictive of worse outcome scores compared with the nonarthritic cohort (odds ratio, 2.5; 95% confidence interval, 1.2 to 5.3; P = .02). Youth (age <40 years) is predictive of good to excellent results (odds ratio, 7; 95% confidence interval, 2.9 to 16.9; P < .0001).

CONCLUSIONS

Of the 98 patients who completed the questionnaires in this study, 71 (72%) obtained good to excellent outcome scores. Overall satisfaction among patients undergoing hip arthroscopy was high (84%). Patients aged younger than 40 years did better than older patients, and arthroscopically identified arthritis was predictive of worse surgical outcomes.

LEVEL OF EVIDENCE

Level III, case-control study.