Radiographic Parameters of Adult Hip Dysplasia.

As knowledge about the origin and morphologic characteristics of hip pain in the young adult has evolved, so too has the clinician's ability to assess for various pathologies of the hip on radiographs, magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA), and computed tomography (CT). Because there is no algorithm at this time directly indicating what to do in more subtle hip morphologies, such as microinstability and borderline hip dysplasia (BHD), a skilled hip preservation specialist must use multiple imaging sources and know how to interpret them correctly. Imaging parameters used in the workup for hip dysplasia and BHD include the lateral center-edge angle, Tönnis angle, iliofemoral line, and presence of an upsloping lateral sourcil or everted labrum, among many others. The purpose of this narrative review was to detail various established criteria and parameters on anteroposterior pelvis plain radiographs, MRI/MRA, and CT that assist in defining the nature and severity of instability present in a dysplastic hip, thereby aiding in the development of patient-specific surgical treatment plans.

Correlation of Delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) Value With Hip Arthroscopy Intraoperative Findings and Midterm Periacetabular Osteotomy Outcomes.

Background: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is an advanced imaging technique that is purported to quantify cartilage damage in acute and chronic joint disease and predict periacetabular osteotomy (PAO) outcomes. There is a paucity of literature relating dGEMRIC values to arthroscopic findings before PAO and postoperative outcomes after PAO. Purpose: To assess the utility and validity of dGEMRIC as a preoperative and prognostic assessment tool of cartilage status and integrity as it relates to intraoperative findings and midterm postoperative outcomes after PAO. Study Design: Case series; Level of evidence, 4. Methods: We analyzed a cohort of 58 patients (70 hips) with a median age of 30.1 years (range, 15-50) with hip dysplasia who underwent hip arthroscopy, followed by a PAO with preoperative dGEMRIC. The primary outcome measures were intraoperative assessment and correlation with cartilage damage (presence of cartilage flap, Outerbridge grade of the acetabulum and femoral head). Secondary outcome measures were postoperative patient-reported outcome (PRO) scores, including the International Hip Outcome Tool and Non-arthritic Hip Score. Correlation analyses were performed to determine the relationship between dGEMRIC values and (1) PROs and (2) intraoperative assessment of cartilage damage. Results: There were significant negative linear relationships between dGEMRIC values and the primary outcome measures: presence of a cartilage flap (coronal, P = .004; sagittal, P < .001), Outerbridge grade of acetabular articular cartilage lesion (coronal, P = .002; sagittal, P = .003), and Outerbridge grade of femoral head articular cartilage lesion (coronal, P = .001; sagittal, P < .001). Despite significant overall improvement in all patients, there was no significant correlation between preoperative dGEMRIC values and improvement in PROs from presurgery to latest postoperative follow-up (median, 2.2 years; range, 1.0-5.0 years). Conclusion: Although dGEMRIC values (sagittal and coronal) were significant predictors of the intraoperative presence of cartilage flaps and overall cartilage integrity, they were not associated with midterm outcomes after PAO.

The Everted Acetabular Labrum: Patho-anatomy, Magnetic Resonance Imaging and Arthroscopic Findings of a Native Variant.

PURPOSE: The purpose of this study was to introduce a native labral variant, the everted acetabular labrum, and to describe the patho-anatomy, magnetic resonance imaging and magnetic resonance arthrogram (MRI/MRA) characteristics and the arthroscopic findings in this condition. METHODS: All primary hip arthroscopy procedures performed by the senior author between June 2013 and January 2020 were reviewed retrospectively. An everted acetabular labrum was identified as a segment of labrum that lacked apposition to the femoral head with the hip off traction. All everted labra were treated with labral advancement and repair with or without augmentation or reconstruction. The labrum-to-femoral head distance was measured in 3T MRI/MRA at the 1-2 o'clock position. A random selection of 38 hips without an everted labrum served as controls to compare radiographic parameters. RESULTS: A total of 68 hips were identified as having an everted labrum during the study period (mean age, 29.1 years), and 55 hips had advanced imaging available for review. MRI/MRA scans revealed the everted labrum to have a triangular shape in 17 hips (31%) and a blunted/round shape in 38 hips (69%), which differed significantly from controls (triangular 25/38 [66%], blunted 13/38 [34%], P < 0.001). The average labrum-to-femoral head distance was 1.4 mm for everted labra versus 0.0 mm for controls (P < 0.0001) and the mean labral lengths and widths were significantly shorter than those of controls (both P < 0.01). Of the hips, 8 underwent labral reconstruction or augmentation, and 61 underwent labral advancement/repair. CONCLUSION: The everted acetabular labrum is a native variant that is identifiable during hip arthroscopy by assessing the labral seal off traction. Preoperative MRI/MRA findings can be highly predictive of an everted labrum. Surgical treatment includes labral advancement and repair or reconstruction to restore contact between the labrum and the femoral head. LEVEL OF EVIDENCE: III, retrospective comparative study.

Comparing Intra-articular Injections of Leukocyte-Poor Platelet-Rich Plasma Versus Low-Molecular Weight Hyaluronic Acid for the Treatment of Symptomatic Osteoarthritis of the Hip: A Double-Blind, Randomized Pilot Study.

BACKGROUND: Hyaluronic acid (HA) and leukocyte-poor platelet-rich plasma (LP-PRP) are 2 nonoperative treatment options that have been studied in patients with hip osteoarthritis (OA). PURPOSE: To compare the efficacy of intra-articular injections of low-molecular weight (LMW) HA and LP-PRP in patients with hip OA. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 34 patients (36 hips) presenting with signs of hip OA were randomized to receive 3 blinded, weekly intra-articular injections of either LP-PRP or LMW-HA. Patients were prospectively evaluated before injections and at 6 weeks and then at 3, 6, 12, and 24 months. The primary outcome, conversion to total hip arthroplasty (THA) or a hip resurfacing procedure, was analyzed along with secondary outcomes including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and hip range of motion. RESULTS: The final analysis included 33 hips (mean Kellgren-Lawrence grade, 2.73) (LMW-HA: n = 14; LP-PRP: n = 19) in 31 patients (18 male; mean age, 53.8 years). Significantly more patients converted to THA or a hip resurfacing procedure in the LMW-HA group (7/14; 50.0%) (mean, 1.3 years after first injection) than the LP-PRP group (3/19; 15.8%) (mean, 0.73 years after first injection) (P = .035). There was no significant improvement or decline in any outcome scores within the LMW-HA group from before injections to 6 weeks or 3, 6, and 12 months. For the LP-PRP group, WOMAC overall (P = .032), joint (P = .030), and function scores (P = .025) significantly improved from before injections to 6 weeks, and WOMAC joint scores significantly improved from before injections to 6 months (P = .036). When comparing the difference between groups in internal rotation at 90° of hip flexion from before injections to 6 months, the LP-PRP group demonstrated a mean 5.0° improvement, while the LMW-HA group showed a mean 1.5° decrease (P = .028). CONCLUSION: Intra-articular hip injections of LP-PRP in patients with hip OA resulted in an improvement in WOMAC scores and hip internal rotation at 6 months and delayed the need for THA or a hip resurfacing procedure compared with treatment with LMW-HA. A longer follow-up is necessary to further compare the effects of LP-PRP and LMW-HA injections in patients with hip OA. REGISTRATION: NCT01920152 (ClinicalTrials.gov identifier).

Pain Scores and Activity Tolerance in the Early Postoperative Period After Hip Arthroscopy.

BACKGROUND: Despite the rapid growth in the use of hip arthroscopy, standardized data on postoperative pain scores and activity level are lacking. PURPOSE: To quantify narcotic consumption and use of the stationary bicycle in the early postoperative period after hip arthroscopy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: In this prospective case series, patients undergoing a primary hip arthroscopy procedure by a single surgeon were asked to fill out a daily survey for 9 days postoperatively. Patients were asked to report their pain level each day on a visual analog scale from 1 to 10, along with the amount of narcotic pain pills they used during those postoperative days (PODs). Narcotic usage was converted to a morphine-equivalent dosage (MED) for each patient. Patients were also instructed to cycle daily starting on the night of surgery for a minimum of 3 minutes twice per day and were asked to rate their pain as a percentage of their preoperative pain level and the number of minutes spent cycling on a stationary bicycle per day. RESULTS: A total of 212 patients were enrolled in this study. Pain levels (POD1, 5.5; POD4, 3.8; POD9, 2.9; P < .0001) and the percentage of preoperative pain (POD1, 51.6%; POD4, 31.8%; POD9, 29.5%; P < .01) significantly decreased over the study period. The amount of narcotics used per day (reported in MED) also significantly decreased (POD1, 27.3; POD4, 22.3; POD9, 8.5; P < .0001). By POD4, 41% of patients had discontinued all narcotics, and by POD9, 65% of patients were completely off narcotic medication. Patients were able to significantly increase the number of minutes spent cycling each day (POD1, 7.6 minutes; POD4, 13.8 minutes; POD9, 19.0 minutes; P < .0001). Patients who received a preoperative narcotic prescription for the affected hip were significantly more likely to require an additional postoperative narcotic prescription (P < .001). CONCLUSION: Patients can expect a rapid decrease in narcotic consumption along with a high degree of activity tolerance in the early postoperative period after hip arthroscopy.

Editorial Commentary: Treating Hip Impingement Without a Computed Tomography Scan? You Might as Well Operate With a Blindfold.

Hip impingement is defined as a bony conflict between the femur and acetabulum occurring throughout normal or supraphysiological range of motion. Traditionally, the cause was attributed to reduced femoral head-neck offset and/or excessive acetabular coverage, giving rise to cam, pincer, and mixed impingement. However, recent outcome studies showing less favorable results of hip arthroscopy in patients with femoral and acetabular version abnormalities have sparked renewed interest in the pathomechanics of hip impingement. We now have a greater appreciation for the 3-dimensional scope of the problem through specialized computed tomography sequencing allowing assessment of the entire limb and pelvis. Consequently, we have learned that rotational hip range of motion is more strongly correlated with combined femoral and acetabular version than with the sphericity of the femoral head, allowing us to counsel patients accordingly. We also recognize that impingement can occur with little to no femoral asphericity if the combined femoral and acetabular version does not permit adequate clearance for unimpeded motion. This improved understanding can be applied to diagnose subtle and uncommon cases of impingement and will ultimately enable a more complete bony resection.

A Contemporary Look at the Evaluation and Treatment of Adult Borderline and Frank Hip Dysplasia.

BACKGROUND: Adult hip dysplasia is often diagnosed according to the lateral center-edge angle (LCEA). Patients with frank hip dysplasia (LCEA <20°) traditionally require treatment with bony realignment through a periacetabular osteotomy (PAO) and/or derotational femoral osteotomy, while patients with borderline hip dysplasia (BHD) present a challenging treatment dilemma, as it remains unknown when they should be treated with hip arthroscopy and/or a PAO. PURPOSE: To perform a narrative review to report the differences in hip morphology and clinical outcomes between adult patients with frank hip dysplasia and BHD. STUDY DESIGN: Narrative review. METHODS: A systematic search of the literature was conducted through the Medline, EMBASE, and Cochrane databases with the search phrase borderline hip dysplasia. RESULTS: The search identified 305 articles, of which 48 were considered relevant to this study after screening of titles and abstracts. Four articles discussed new radiographic means of evaluating adult hip dysplasia, 16 articles analyzed morphology of dysplastic hips, and 28 articles described the clinical outcomes of patients with frank hip dysplasia or BHD treated with hip arthroscopy and/or PAO. Because the level of evidence obtained from this search was not adequate for systematic review or meta-analysis, a current concepts review on the diagnosis, hip morphology, and clinical outcomes of patients with frank hip dysplasia or BHD is presented. CONCLUSION: Adult hip dysplasia is most commonly diagnosed based on the LCEA; however, the LCEA is an unreliable sole marker for dysplasia, and additional radiographic parameters should be utilized. Furthermore, specific pathology identified on imaging and/or during hip arthroscopy can provide clues to a surgeon when the diagnosis is inconclusive according to history and physical examination alone. While the data support that patients with frank dysplasia are best treated with PAO, there is no such preferred treatment for patients with BHD, who have a wide spectrum of instability. Selective use of arthroscopic labral and capsular treatment alone may provide good results in carefully chosen patients with BHD, while some may end up requiring a bony realignment procedure.

Longitudinal versus transverse hip arthroscopy portal cosmesis: a case-control trial of simultaneous bilateral cases.

The direction and nature of incisions can impact the healing and appearance of a surgical scar. This can be attributed mainly due to skin tension and direction of force. The aim of this study was to identify differences in healing rates and scar esthetics between transverse and longitudinal portals used for hip arthroscopy. A total of 75 patients underwent bilateral hip arthroscopy for femoroacetabular impingement. All patients received a portal perpendicular to the long axis of the body on the left side (transverse portal) and parallel with the long axis of the body on the right side (longitudinal portal) for the standard anterolateral viewing portal. Postoperatively, patients were reviewed at 2 weeks, 6 weeks, 3 months and 6 months and the portal scars were assessed, photographed and measured. No patients were lost to follow-up. The transverse scars, although slightly longer, were found to be narrower at 6 weeks (3.8 mm versus 2.7 mm, P < 0.01), 3 months (4.3 mm versus 3.4 mm, P = 0.01) and 6 months postoperatively (6.1 mm versus 4.5 mm, P < 0.01). At 3 months (43 mm2 versus 35 mm2, P = 0.029) and 6 months (49 mm2 versus 43 mm2, P = 0.024), transverse incisions were noted to have significantly reduced total area compared with longitudinal incisions. There were no wound complications in either group. This study demonstrates that transverse portal positions for hip arthroscopy have an advantage over longitudinal portal positions in terms of total scar area and thickness up to 6 months postoperatively.

The "Outside-In" Lesion of Hip Impingement and the "Inside-Out" Lesion of Hip Dysplasia: Two Distinct Patterns of Acetabular Chondral Injury.

BACKGROUND: Femoroacetabular impingement (FAI) and acetabular dysplasia lead to acetabular cartilage damage that commonly results in the chondral flaps seen during hip arthroscopy. PURPOSE: To compare the acetabular chondral flap morphology seen during hip arthroscopy ("outside-in" vs "inside-out") with clinical and radiographic parameters underlying FAI and hip dysplasia. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent hip arthroscopy by the senior author between 2013 and 2017 with a finding of Outerbridge grade IV acetabular chondral flap were included. Each procedure was retrospectively reviewed on video and chondral flaps were categorized as inside-out or outside-in. An inside-out designation was made for flaps exhibiting an intact chondrolabral junction with a detached sleeve of chondrolabral tissue from the central acetabulum, and an outside-in designation was made for centrally anchored flaps exhibiting a break in the chondrolabral junction. Radiographic markers of hip impingement/dysplasia were noted for each patient during assignment into 1 of 2 radiographic groups: group 1, lateral center edge angle (LCEA) >20 with FAI, and group 2, LCEA ≤20 with or without cam FAI. Associations between chondral flap morphology and clinical diagnosis were tested using a chi-square test. RESULTS: Overall, 95 patients (103 hips) were included (group 1, 78 hips; group 2, 25 hips). Among hips in group 2, 24 had concurrent cam FAI. There was a significant relationship between chondral flap type and radiographic diagnosis (P < .001). Among group 1 hips, 78% exhibited outside-in type chondral flaps, 12% exhibited combined outside-in and inside-out flaps, and 10% exhibited inside-out flaps. Group 2 hips showed 72% inside-out type chondral flaps, 16% combined, and 12% outside-in. Hips exhibiting outside-in type flaps were significantly more likely to be in group 1 (positive predictive value [PPV], 91%; negative predictive value [NPV], 69%). Similarly, hips exhibiting inside-out type flaps were significantly more likely to be in group 2 (PPV, 56%; NPV, 95%). Altogether, 90% of group 1 hips exhibited an outside-in lesion and 88% of group 2 hips exhibited an inside-out lesion. CONCLUSION: Acetabular chondral flap type visualized during hip arthroscopy correlates with radiographic markers of hip impingement and hip instability. Outside-in flaps are highly predictive of FAI, whereas inside-out flaps are highly predictive of acetabular dysplasia.

The CU PAO: A Minimally Invasive, 2-Incision, Interlocking Periacetabular Osteotomy: Technique and Early Results.

BACKGROUND: The aims of this study were to describe a novel minimally invasive, interlocking periacetabular osteotomy (PAO) for the treatment of hip dysplasia that was developed at our institution and to report on its safety, complications, and early clinical outcomes. METHODS: This was a prospective longitudinal study of the first 200 consecutive hips that underwent the CU (University of Colorado) PAO, an interlocking osteotomy combining the benefits of the Birmingham interlocking pelvic osteotomy (BIPO) and the Ganz PAO. The technique provides direct visualization of the sciatic nerve during the ischial osteotomy and allows for immediate weight-bearing postoperatively. Demographic characteristics, intraoperative and perioperative parameters, and functional outcomes were documented. All patients underwent hip arthroscopy 3 to 10 days prior to the PAO to address concomitant intra-articular pathology. Mechanical deep venous thrombosis (DVT) prophylaxis was used for 2 weeks postoperatively. Results were stratified to compare the first 100 and the second 100 cases. RESULTS: A total of 161 patients (200 hips) underwent primary PAO; mean follow-up was 20 months (range, 3 to 33 months). The mean patient age at the time of surgery was 29.4 years (range, 13 to 55 years). Females accounted for 89% of the patients included in this study. The average length of stay was 4 days. A concomitant proximal femoral derotational osteotomy was performed in 19 hips. The lateral center-edge angle (LCEA) improved from a mean of 18.8° preoperatively to 31.5° postoperatively (p < 0.001). The mean Non-Arthritic Hip Score (NAHS) improved from 56.0 preoperatively to 89.4 at the 24-month follow-up (p < 0.0001). Paresthesias in the distribution of the lateral femoral cutaneous nerve were common (65% at 2 weeks postoperatively) but resolved in 85% of the patients within the first 6 months. There were no sciatic nerve-related complications, deep infections, or DVTs. CONCLUSIONS: The CU PAO enables corrective realignment of symptomatic acetabular dysplasia with direct visualization of the sciatic nerve, early weight-bearing, cosmetic incisions, and good short-term outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effects of Hip Arthroscopy Without a Perineal Post on Venous Blood Flow, Muscle Damage, Peripheral Nerve Conduction, and Perineal Injury: A Prospective Study.

BACKGROUND: Prior reports of hip arthroscopy using a perineal post have established the risks of groin soft tissue injury, sexual dysfunction, and altered lower extremity neurovascular function. These parameters have not been investigated for hip arthroscopy without the use of a perineal post. PURPOSE: To evaluate the effects of postless hip arthroscopy on lower extremity venous blood flow, nerve conduction, muscle tissue damage, and perineal injury. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients between the ages of 18 and 50 years undergoing an elective unilateral or simultaneous bilateral hip arthroscopy were enrolled. Creatine phosphokinase (CPK)-MM levels and D-dimer levels were obtained preoperatively, immediately postoperatively, and 7 to 12 days postoperatively. Bilateral Doppler ultrasonography of the common femoral vein (CFV) and popliteal vein were conducted intraoperatively. Somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (TcMEPs) were measured intraoperatively for the lower limbs. Perineal injury was assessed at 7 to 12 days postoperatively. RESULTS: 35 patients underwent a total of 40 hip arthroscopies. No significant differences were found in venous blood flow between the operative and nonoperative legs for either the CFV or popliteal vein. SSEP monitoring of the peroneal nerve showed no significant reduction when traction was applied to the operative leg, 90.8%, compared with final measurement just before it was removed, 72.4% (P = .09). For TcMEPs measured in the muscles outside of the traction boots, no significant changes were seen in the percentage of cases with abnormal measurements throughout the procedure. CPK-MM levels preoperatively, immediately postoperatively, and 7 to 12 days after surgery were on average 112, 190, and 102 IU/L, respectively (normal, <156 IU/L). No significant relationship was found between abnormal venous flow and altered D-dimer levels. No clinical evidence of nerve or vascular injury was encountered, and no groin soft tissue complications were observed during the study period. CONCLUSION: Postless hip arthroscopy is safe, without a notable reduction of venous blood flow or alteration of nerve function in the operative leg. Muscle tissue damage is subclinical, transient, and reduced compared with distraction with a post. No cases of perineal injury were observed during the study period.

Increased Prevalence of Femoroacetabular Impingement in Patients With Proximal Hamstring Tendon Injuries.

PURPOSE: To determine the prevalence of clinically diagnosed femoroacetabular impingement (FAI) in a consecutive series of patients presenting with proximal hamstring tendon injury and to correlate this with pelvic anatomic factors. METHODS: The prevalence of clinically symptomatic cam-, pincer-, and mixed-type and overall FAI was calculated among a consecutive series of patients presenting to a hip preservation clinic with a confirmed clinical and radiographic diagnosis of proximal hamstring tendon injury between 2012 and 2017. The presence of a cam lesion was determined by an alpha angle > 50° on radiographs and computed tomography radial sequences of the head-neck junction and a femoral head-neck offset ratio < 0.18. Clinical diagnoses of osseous impingement were determined according to accepted pathomorphologic signs and measurements. A diagnosis of FAI was confirmed by imaging findings of acetabular overcoverage for pincer-type FAI and the presence of an anterior or lateral cam lesion for cam-type FAI. RESULTS: Overall, 120 hips in 97 patients (mean age, 45 years) were included in this study. A clinical diagnosis of FAI was noted in 70.8% of hips (pincer-type 9.2%, cam-type 40.8%, mixed-type 20.8%), an approximate 2- to 7-fold increased prevalence in comparison with the general population from prior studies. CONCLUSIONS: The prevalence of FAI is high in patients with symptomatic proximal hamstring tendon pathology. Because FAI results in restriction of hip range of motion and altered pelvic tilt, future studies are warranted to investigate whether the presence of FAI acts as a predisposing factor for injury to the hamstring muscle complex. LEVEL OF EVIDENCE: Level IV, case series.

Editorial Commentary: Which Allograft Is Superior for Hip Capsular Reconstruction? Let's Choose the Right Patient Before We Choose the Right Graft.

The hip is an inherently stable joint. Acetabular depth and version, femoral torsion, and congruency of articulation form the pillars of hip stability, with the labrum and capsule serving as secondary stabilizers. The increasing prevalence of capsular deficiency in the setting of revision hip arthroscopy has led to the development of capsular reconstruction techniques. The first step in hip capsular reconstruction, however, is selecting the right patient for the procedure.

Simultaneous Bilateral Hip Arthroscopy in Adolescent Athletes With Symptomatic Femoroacetabular Impingement.

BACKGROUND: Femoroacetabular impingement represents a common cause of hip pain in adolescents. The purpose of the present study was to evaluate the safety and efficacy of simultaneous bilateral hip arthroscopy for bilateral symptomatic femoroacetabular impingement in adolescent athletes. METHODS: Clinical data were collected in a prospective database on patients who underwent unilateral or simultaneous bilateral hip arthroscopy and included complications, reoperation rate, and return to play time. Differences in International Hip Outcome Tool (iHOT)-12 scores according to hip side and postoperative follow-up time (preoperative, 1.5, 3, 6, 12, and 24 mo) were evaluated using a 2×6 repeated-measures analysis of variance with post hoc repeated-measures 1-way analysis of variance and Bonferroni-corrected paired t tests. RESULTS: In total, 24 patients (36 hips) were studied, of whom 12 underwent simultaneous bilateral hip arthroscopy (24 hips) and a case-matched control group of 12 patients underwent unilateral hip arthroscopy. There were 5 males in each group (41.7%). Average age was 15.7 and 16.5 years in the bilateral and unilateral groups, respectively. No patients were lost to follow-up. In the bilateral group, a significant increase in mean iHOT-12 score was observed between 1.5- and 3-month follow-up (61.8 vs. 82.8, respectively; P=0.003), and 6-, 12-, and 24-month follow-up (91.4, 95.1, and 96.6, respectively, P=0.004). At all follow-up times, there were no significant differences in mean iHOT-12 scores or other outcome measures between bilateral and unilateral cohorts. Time to return to preinjury level of activity was similar between the bilateral and unilateral groups (4.7 vs. 4.9 mo, respectively; P=0.40). One transient lateral femoral cutaneous nerve palsy occurred in each group, though no other complications were documented. No patients required revision surgery by latest follow-up. CONCLUSIONS: Bilateral simultaneous hip arthroscopy is safe and reproducible in adolescent athletes, achieving equivalent outcomes, and similar rehabilitation time when compared with unilateral surgery. LEVEL OF EVIDENCE: Level II-therapeutic study.

Combined Lateral Osseolabral Coverage Is Normal in Hips With Acetabular Dysplasia.

PURPOSE: To compare the lateral osseolabral coverage between groups of patients with different degrees of acetabular bony coverage using a magnetic resonance imaging parameter known as the combined lateral center-edge angle (cLCEA). METHODS: The cLCEA was measured among a consecutive series of patients presenting to a dedicated hip preservation surgeon with a magnetic resonance imaging scan. The cLCEA was measured using a coronal T1 or proton density image and was defined as the angle subtended by (1) a line through the center of the femoral head and orthogonal to the transverse line passing through the teardrops of both hips and (2) an oblique line drawn from the center of the femoral head to the free edge of the lateral acetabular labrum. The average difference between the lateral center-edge angle (LCEA) and the cLCEA was calculated and compared between groups based on acetabular bony coverage: dysplasia (LCEA <20°), borderline dysplasia (LCEA 20°-24.9°), normal coverage (LCEA 25°-39.9°), and overcoverage (LCEA ≥40°). RESULTS: In total, 341 patients (386 hips) were included. There were no significant differences in cLCEA between hips with normal acetabular coverage and dysplasia (P = .10) or borderline dysplasia (P = .46). Despite the large difference in mean LCEA between dysplasia (14.8° ± 3.9°) and acetabular overcoverage (43.1° ± 2.8°), the mean cLCEA values exhibited only a modest difference (44.7° ± 4.9° vs 52.7° ± 4.5°, respectively). Concordantly, hips with dysplasia exhibited the largest difference between mean LCEA and cLCEA (delta = 29.9° ± 4.7°) and hips with acetabular overcoverage had the smallest difference between measures (9.6° ± 5.2°). CONCLUSIONS: With decreasing acetabular bony coverage, there is increasing labral size such that the total osseolabral coverage, measured by the combined LCEA, remains equivalent between hips with normal acetabular coverage versus dysplasia. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Efficacy of a non-image-guided diagnostic hip injection in patients with clinical and radiographic evidence of intra-articular hip pathology.

The purpose of this study was to determine the likelihood of pain relief, as a measure of accurate diagnosis of intra-articular hip pathology and correct needle placement, with a non-image-guided intra-articular hip injection performed bedside in the clinic. A retrospective study of prospectively collected data was performed in a consecutive cohort of patients diagnosed with symptomatic intra-articular hip pathology who underwent a non-image-guided intra-articular injection in the clinic. All patients had clinical and radiographic evidence of hip impingement, hip instability, chondrolabral pathology, or other causes of intra-articular hip pain. A previously described technique for a non-image-guided hip injection was performed using 7-10 ml of 1% lidocaine for diagnostic evaluation with some patients receiving 2 ml of Kenalog®-40 if clinically indicated. Ten minutes following each injection, the patient was asked to report the percent improvement in pain (from 0 to 100%) while physical examination and provocative tests were repeated. The final study cohort comprised 142 patients (161 injections). In three cases, patients were either unable to assess or quantify any change in pain level 10 min following the injection. In the remaining 158 hip injections, pain relief was noted in 156 cases (156/158, 98.7%), with at least 70% improvement in pain level noted in 152 cases (152/158, 96.2%). Average pain relief among all 158 injections was 89 ± 16%. A non-image-guided diagnostic intra-articular hip injection yields reliable short-term pain relief, simultaneously endorsing accurate diagnosis of hip pathology and intra-articular needle placement.

Incidence of deep venous thrombosis following periacetabular and derotational femoral osteotomy: a case for mechanical prophylaxis.

There are currently no established guidelines for appropriate antithrombotic prophylaxis following periacetabular osteotomy (PAO) or derotational femoral osteotomy (DFO). The purpose of this study was to determine the incidence of clinical deep venous thrombosis (DVT) following PAO and/or DFO wherein a portable, mechanical device and low-dose aspirin were used postoperatively for DVT prophylaxis. Patients who had undergone staged hip arthroscopy and primary PAO and/or DFO were prospectively reviewed. Following PAO/DFO, patients were prophylactically treated for thromboembolic disease with a portable, mechanical compression device for 3 weeks and low-dose aspirin for 4 weeks. Patients were followed in clinic until 24 months postoperatively. During the study period, 145 hips (124 patients) underwent surgery (PAO: 109, DFO: 24, PAO + DFO: 12). Overall, the incidence of clinically apparent DVT was 0% in the study cohort. Average estimated blood loss during surgery was 601 mL and five cases required blood transfusions of 1 or 2 units. Ten patients were seen in the emergency room 10-20 days after surgery presenting with calf tenderness and DVT was ruled out in all cases with ultrasound. There were no postoperative bleeding or wound complications. A portable, mechanical compression device and low-dose aspirin effectively lessens the risk of DVT following staged hip arthroscopy and PAO/DFO without an increased risk of bleeding complications.

Standardizing the Prearthritic Hip Joint Space Width: An Analysis of 994 Hips.

PURPOSE: The purposes of this study were (1) to define a normal prearthritic hip joint space width (JSW) in symptomatic and asymptomatic patients with various degrees of acetabular coverage based on the lateral center edge angle (LCEA) and (2) to determine predictors of JSW using patient-specific variables. METHODS: In a consecutive series of patients presenting to a hip preservation clinic between July 2012 and April 2016, a standard weight-bearing anteroposterior pelvic view was obtained. JSW was defined as the distance between the bony contour of the acetabular rim and femoral head in 2 locations (lateral and medial weight-bearing zone). Hips with severe anatomic deformity, a Tönnis grade >0, or a lateral or medial JSW <2.5 mm were excluded. A linear mixed model analysis was performed in order to determine which variables (age, sex, side, height, weight, symptomatic/asymptomatic, LCEA, and clinical diagnosis) were significantly related to JSW. RESULTS: A total of 994 hips were included. LCEA was found to be a significant predictor of both the lateral and medial JSW, with a decreased JSW associated with increasing degrees of acetabular bony coverage (P < .02). A mean 0.9 mm (20%) difference in medial JSW was found between patients with frank dysplasia (LCEA <20°) compared with those with pincer-type FAI (LCEA ≥40°). There was no difference between symptomatic and asymptomatic hips, either for lateral (asymptomatic: 4.51 ± 0.83 mm; symptomatic: 4.52 ± 0.85 mm; P = .58) or medial JSW (asymptomatic: 4.02 ± 0.96 mm; symptomatic: 3.97 ± 0.84 mm; P = .49). CONCLUSIONS: The LCEA is a significant predictor of hip JSW, with the mean JSW decreasing with increasing degrees of acetabular bony coverage. Joint space is not a major factor in symptomatology in adults with prearthritic hip pain. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Femoral Version Abnormalities Significantly Outweigh Effect of Cam Impingement on Hip Internal Rotation.

BACKGROUND: The purpose of this study was to investigate the effects of femoral version, cam-type femoroacetabular impingement (FAI), and the combination of the 2 on the passive hip range of motion (ROM). METHODS: We prospectively analyzed a consecutive cohort of 220 patients (440 hips) who presented with unilateral or bilateral hip pain. The passive hip ROM was measured bilaterally with the patient in prone, supine, and lateral positions. Femoral version was measured and the presence of cam-type deformity was determined on preoperative computed tomography (CT) scans. Diagnostic findings of cam-type FAI included an alpha angle of >50° on CT radial sequences of the head-neck junction and a femoral head-neck offset ratio of <0.18 on both radiographs and CT. RESULTS: Multivariate linear regression analysis confirmed that femoral version, as compared with the presence of a cam lesion, was a stronger independent predictor of internal rotation ROM. Conversely, the presence of a cam lesion resulted in a significant decrease in the passive hip flexion ROM (p < 0.001) with no additional effects due to the degree of femoral version. The passive hip internal rotation ROM in neutral flexion/extension and with the hip in 90° of flexion were maximized in patients with femoral anteversion and decreased significantly with each incremental decrease in femoral version (p < 0.001). CONCLUSIONS: Abnormalities in femoral version significantly outweigh the effect of cam-type impingement on the passive hip internal rotation ROM. In contrast, the presence of a cam lesion significantly decreases the hip flexion ROM, irrespective of the degree of femoral version. These findings help to inform surgical decision-making for patients with cam-type FAI or femoral version abnormalities. CLINICAL RELEVANCE: It is common clinical practice to ascribe loss of hip internal rotation to the presence of a cam lesion and to assume that arthroscopic femoral osteoplasty will substantially improve internal rotation postoperatively. Our study shows that the cam lesion is more intimately tied to hip flexion than to hip internal rotation. This result directly impacts the clinical assessment of a patient presenting with radiographic findings of FAI.