Glass microbeads in coastal sediments as a proxy for traffic-related particulate contamination.

Retroreflective glass microbeads used in road markings have been characterised and subsequently identified in urban coastal sediments. Clear or translucent silica beads range in diameter from about 30 to 700 µm and readily break from the matrix of detached or damaged markings on abrasion. At an urban location close to the city centre of Plymouth, southwest England, and in an estuary below a large road bridge, microbeads were detected in nearly all intertidal sediments analysed (n = 18) and at concentrations up to about 550 kg-1 dw. At a location not immediately impacted by major roads, beads were entirely absent from sediments (n = 9). With a size range and density similar to silt-sand, glass beads appear to accumulate in sediment subject to road runoff and act as persistent proxies for traffic-related contamination. Although beads are unlikely to be inherently toxic, they may serve as indicators of more harmful chemicals in road dust.

Microplastics in coastal urban sediments: Discrepancies in concentration and character revealed by different approaches to sample processing.

Intertidal, silty sediment samples have been collected from three coastal locations with different uses and anthropogenic signatures in the vicinity of Plymouth, southwest England, and analysed for microplastics (MPs) by two independent means. Firstly, MPs were counted and characterised directly on unprocessed dried sediment under a stereo microscope, and secondly MPs were isolated from sediment by flotation in ZnCl2 solution and filtration before analysis. Direct counting resulted in average (± one standard deviation) numbers of MPs per g of dry sediment of 0.77 ± 0.16 at a marina-harbour, 0.58 ± 0.30 under a busy road bridge and 0.79 ± 0.43 adjacent to country parkland. After flotation and filtration, concentrations were reduced to 0.24 ± 0.11, 0.18 ± 0.06 and 0.48 ± 0.38 MP g-1, respectively. Observations were attributed to hetero-aggregation of small fibres with settling sediment during flotation, and the presence of MPs (including paints) that were too dense to float or that had aggregated or agglomerated with denser sediment and construction material in situ. The findings have implications for the efficacy of flotation procedures, accurate estimations of MP concentrations in sediment and the representativeness of MPs by type, and inter-site comparisons of MPs that are widely reported in the literature.

Does the Use of Psychotropic Medication Adversely Affect the Outcomes of Hip Arthroscopy?

BACKGROUND: Over the past decade, the use of psychotropic medications (PTMs) in the United States has doubled, and currently 20% of adults are taking 1 or more of these antidepressant, antianxiety, antipsychotic, or mood-altering medications. To date, however, the incidence of PTM use in patients undergoing hip arthroscopy and the results of hip arthroscopy in these patients have not been reported. PURPOSE: To determine the prevalence of PTM use in patients undergoing hip arthroscopy and to compare the outcomes of patients taking PTMs versus those of patients not taking PTMs. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Medical records of 880 consecutive patients who underwent hip arthroscopy performed by the senior author were reviewed and data were collected, including the number and types of PTMs that these patients were taking at the time of their hip arthroscopy. All hips were assessed with the Byrd modified Harris Hip Score (mHHS) preoperatively; 709 patients (81%) had scores obtained at 12 months and 669 patients (76%) at 24 months after surgery. Demographic data and mHHS of patients taking psychotropic medications (PTM group) were compared with those of patients not taking PTMs (NPTM group). RESULTS: Four hundred twenty-two (48%) of the 880 patients studied were taking PTMs at the time of their hip arthroscopy; significant differences between the PTM and NPTM groups were average age (48 vs 35 years, respectively), and the high percentage of females (53%) and low percentage of males (38%) in the PTM group. Preoperative scores for the PTM and NPTM groups were similar (41 vs 42 points, respectively), but postoperative scores of the PTM group were significantly lower at 6 months (72 vs 89 points), 12 months (77 vs 91 points), and 24 months (79 vs 88 points) after surgery ( P = .01). In contrast, the scores of the subgroups of PTM and NPTM adolescents obtained at 3 months (92.5 vs 88.9 points), 6 months (92.1 vs 90.3 points), 12 months (89.5 vs 92.1 points), and 24 months (90.3 vs 90.1 points) after surgery did not significantly differ. CONCLUSION: The incidence of PTM use in this series of patients with hip arthroscopy was triple that reported for US adults (48% vs 17%, respectively) and adolescents (23% vs 6.3%), and the PTM group had significantly lower 12- and 24-month mHHS results than the NPTM group. These results suggest that (1) patients undergoing hip arthroscopy who are taking PTMs are at significantly higher risk for poor outcomes and (2) their use of PTMs should be identified and addressed before proceeding with hip arthroscopy.

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

BACKGROUND: Iliopsoas (IP) muscle atrophy is a known consequence of open IP tenotomy, but the severity of IP muscle atrophy that occurs after arthroscopic labral-level IP tenotomies has not been documented. PURPOSE: To document the severity of muscle atrophy that occurs in the iliacus, psoas, and adjacent hip musculature after arthroscopic labral-level IP tenotomy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-eight patients who had magnetic resonance arthrograms (MRAs) obtained prior to and 3 months to 5 years after arthroscopic labral-level IP tenotomies are the basis of this report. The pre- and postoperative MRAs of each patient were examined in consensus by 2 musculoskeletal radiologists who graded the postoperative muscle atrophy from 0 (no fatty infiltration) to 4 (>75% fatty infiltration) and noted any compensatory muscle hypertrophy or abnormal IP tendon morphology. Patients also were assessed with the Byrd 100-point modified Harris Hip Scoring system (MHHS) preoperatively and at the time of their postoperative MRA. RESULTS: Postoperative MRAs were obtained on average 1.7 years (range, 3 months to 5 years) after hip arthroscopy. None of the patients had muscle atrophy on their preoperative MRAs. In contrast, 89% of patients had iliacus and psoas muscle atrophy on their postoperative MRAs, but only 2 (7%) developed grade 4 atrophy, and the majority (64%) had either grade 1 (n = 15) or no atrophy (n = 3). In addition, there were no significant differences in the MHHS of the patients with mild (grades 0-1), moderate (grades 2-3), or severe (grade 4) postoperative atrophy. Postoperative MRAs also demonstrated low-grade atrophy (grades 1-2) in the quadratus femoris (n = 5) and rectus femoris (n = 1) muscles, and 16 patients (57%) had distortion of the tendon, but none had a gap in their tendon. CONCLUSION: A majority of patients (89%) developed IP muscle atrophy after arthroscopic labral-level IP tenotomies, and although this percentage was similar (89% vs 90%) to that reported with lesser trochanteric IP tenotomies, the patients did not (1) develop atrophy of the gluteus maximus and vastus lateralis muscles, (2) have chronic IP tendon disruption, or (3) develop the severity of IP atrophy (55% grade 4 vs 7% grade 4) that has been reported after arthroscopic lesser trochanteric IP tenotomies.

Treatment of ischiofemoral impingement: results of diagnostic injections and arthroscopic resection of the lesser trochanter.

Ischiofemoral impingement (IFI) is an often unrecognized cause of hip pain caused by abnormal contact between the lesser trochanter and the ischium. To date, surgical treatment for those whose pain is not relieved by activity modification and steroid injections has not been defined. This study describes our imaging protocol and reports the results of arthroscopic, lesser trochanteric resections that were performed to treat this condition. Seven patients with symptomatic, MRI-documented IFI had ultrasound injections of ropivicaine and steroid into their ischiofemoral space. The injections provided complete but only transient relief of their groin and buttock pain and thus, all seven ultimately had an arthroscopic resection of their lesser trochanter. All hips were evaluated preoperatively and at 3, 6 and 12 months postoperatively with Byrd's modified Harris hip scoring system. Average age of the seven patients was 46 years and there were five females and one male. Preoperative scores averaged 43 points. After surgery, all patients used crutches for 4-6 weeks, and had 6-week scores that averaged 58 points. The patients and their scores continued to improve and at 6 and 12 months, their scores averaged 86 and 91 points, and none had chronic hip flexor weakness or recurrence of their hip pain or snapping. Arthroscopic iliopsoas tenotomies in combination with a resection of the lesser trochanter will provide complete relief of the painful snapping, groin and buttock pain caused by ischiofemoral impingement.

Correlation Between Hip Arthroscopy Outcomes and Preoperative Anesthetic Hip Joint Injections, MR Arthrogram Imaging Findings, and Patient Demographic Characteristics.

OBJECTIVE: The purpose of this study is to determine whether the preoperative response to intraarticular hip anesthetic injection correlates with the outcome of hip arthroscopy. A secondary aim is to determine whether the outcome of arthroscopy correlates with intraarticular pathologic findings or patient demographic characteristics. MATERIALS AND METHODS: Ninety-three patients who underwent MR arthrography (MRA), preoperative injections of anesthetic into the hip joint (with pain scores documented), and subsequent hip arthroscopy (with a modified Harris Hip Score [mHHS] determined at 1 year after arthroscopy) were included in the study. MRA images and surgery reports were retrospectively reviewed to identify information about labral tear type and size and cartilage damage grade. The correlation between the response to hip anesthetic injection (defined as poor [0-30% improvement], moderate [31-60% improvement], or good [61-100% improvement]) and the surgical outcome (poor, fair, or good, as determined on the basis of the mHHS or the need for repeat surgery) was evaluated using the Fisher exact test. Univariate analysis (performed using the Fisher exact test) and multivariate analysis (performed using ANOVA) of correlations with age, sex, body mass index (BMI [weight in kilograms divided by the square of height in meters]), the interval between injection and surgery, labral tear type and size, and cartilage damage grade were also performed. RESULTS: Comparison of the response to preoperative hip anesthetic injection with the outcome of arthroscopy at 1 year indicated no statistically significant association (p = 0.59). The BMI of the patient, however, was statistically significantly associated with surgical outcome (p = 0.03), with a BMI of less than 25 denoting a higher likelihood of a good surgical outcome. No statistically significant correlations were noted in analyses of surgical outcomes and patient age (p = 0.31) and sex (p = 0.83); the interval between injection and surgery (p = 0.28); labral tear type, as determined by MRA (p = 0.34) and arthroscopy (p = 0.47); labral tear size, as determined by MRA (p = 0.34); and cartilage grade, as determined by MRA (p = 0.58) and arthroscopy (p = 0.26). CONCLUSION: No positive or negative correlation was noted between the response to preoperative hip anesthetic injection and the outcome at 1 year after hip arthroscopy. Only BMI was shown to correlate with the surgical outcome.

Analysis of the Current Indications for Microfracture of Chondral Lesions in the Hip Joint.

BACKGROUND: Data on the efficacy of microfracture for treatment of chondral defects in the hip are currently limited, and the recommended criteria for its use (minimal osteoarthritis; a focal, contained lesion <4 cm2 in size) have been taken from those that were established for the knee. PURPOSE: To determine if the current microfracture (ie, knee) criteria are appropriate for chondral lesions in the hip. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Seventy patients who had hip arthroscopy and 2 years of follow-up after treatment of labral tears and cam and pincer bony deformities, as well as microfracture of full-thickness chondral defects, are the basis of this study. The size and location of the chondral defects were recorded on each patient's "hip sheet" and operative note at the time of hip arthroscopy and were confirmed from intraoperative photographs. The chondral defects were debrided and microfractured regardless of their size. All hips were assessed with the 100-point modified Harris Hip Score (mHHS) before arthroscopy and at 3, 6, 12, and 24 months after surgery. Patients who had a total hip arthroplasty or repeat arthroscopy during their 2-year follow-up period were assigned poor results. RESULTS: The average age of the 70 patients was 41 years, and the average size of the lesions microfractured was 143 mm2. Outcomes, based on patients' 2-year mHHS or being assigned a poor result for revision surgery, were as follows: 32 excellent, 11 good, 6 fair, and 21 poor; overall, 43 patients (61%) had good and excellent results, and 27 (39%) had fair and poor results. The revision surgery rate was 24%. Seven of the 70 patients had chondral lesions greater than the recommended size for microfracture in the hip (>400 mm) and ranged from 430 to 750 mm2. Their 2-year outcomes included 3 excellent, 1 good, 1 fair, and 1 poor result; the outcomes were the same as for the 8 patients with medium (200-400 mm2) and the 55 patients with smaller (<200 mm2) lesions (P = .25). There also was no difference in the 2-year outcomes of the older patients (age ≥50 years; P = .91). CONCLUSION: Microfracture in the hip should not be limited to the criteria of knee lesions (<400 mm2) or to younger patients (age <50 years). However, the results also indicate that patients with full-thickness cartilage defects can anticipate a high rate of conversion to total hip arthroplasty within 2 years of their microfracture surgery and that only 60% of them will have good/excellent results over that time period.

Correlation of ultrasound-guided corticosteroid injection of the quadratus femoris with MRI findings of ischiofemoral impingement.

OBJECTIVE: MRI findings of ischiofemoral impingement (IFI) have been described, but there is little evidence for treatment with ultrasound-guided corticosteroid injection. The purpose of this study was to evaluate the effectiveness of ultrasound-guided corticosteroid injection of the quadratus femoris muscle as a treatment of IFI syndrome and to correlate the MRI findings with injection outcome. MATERIALS AND METHODS: The medical records of 61 consecutively registered subjects who underwent bony pelvis MRI in which either IFI or quadratus femoris edema was described in the radiology report were retrospectively reviewed. Subjects with MRI findings of IFI and clinical confirmation of pain that could be attributed to IFI were included and divided into injection and control groups based on clinical management. Control subjects had MRI findings and clinical symptoms suggestive of IFI but underwent conservative therapy rather than injection. The control patients had adequate follow-up and clinical documentation to determine their response to treatment. Quadratus femoris muscle edema, fat atrophy, and hamstring tendinopathy were graded from none to severe (grades 0-3). The ischiofemoral and quadratus femoris spaces were also measured. Clinical presentation was classified as typical, somewhat typical, or not typical of IFI. Injection effectiveness was determined by reported pain reduction assessed before, immediately after, and 2 weeks after the procedure with a standard 10-cm visual analog scale. Response to treatment was classified as good (reduction in pain level > 2), mild or partial (reduced by 1 or 2), or no improvement. For patients who did not return their 2-week postinjection pain surveys, injection effectiveness was determined by qualitative assessments found in their clinical notes. A Kruskal-Wallis rank sum test was used to compare effectiveness of injection between groups (p < 0.05). The Fisher exact test was used to evaluate for associations between each MRI finding and injection outcome. RESULTS: Of the 61 patients, 20 patients had both MRI findings and clinical confirmation of pain related to IFI. These 20 patients were included in the study. Fifteen ultrasound-guided injections were performed in seven patients, and these seven patients were included in the injection group (mean age, 47 years; range, 15-66 years); 13 patients were included in the control group (mean age, 42 years; range, 16-62 years). All seven patients in the injection group and 12 of the 13 patients in the control group were women. In the injection group, the mean width of the ischiofemoral space was 12 mm (range, 7-22 mm), and the mean width of the quadratus femoris space was 9 mm (range, 5-16 mm). The mean edema grade was 1.4 (range, 0-3); mean atrophy grade, 1.4 (range, 0-3); and mean hamstring tendinopathy grade, 1 (range, 0-2). In the control group, the mean width of the ischiofemoral space was 9 mm (range, 6-17 mm); mean quadratus femoris space width, 7 mm (range, 3-15 mm); mean edema grade, 1.9 (range, 1-3); mean atrophy grade, 1.2 (range, 0-3); and mean hamstring tendinopathy grade, 1.2 (range, 0-3). No statistical difference was seen between the two groups before treatment. Pain reduction after injection over the 2-week period was statistically significant with a mean reduction of 1.7 (range, 1-2) for the injection group and 0.8 (range, 0-2) for the control group (p < 0.01). Eleven of 15 (73%) of the injections provided good relief, and four of 15 (27%) provided mild relief. None of the 15 injections provided no relief. In the control group, four of 14 (29%) subjects had good relief, three of 14 (21%) had mild relief, and seven of 14 (50%) had no relief (p < 0.01). CONCLUSION: Ultrasound-guided corticosteroid injection of the quadratus femoris muscle shows promise as an effective treatment of IFI syndrome. However, larger longitudinal studies are needed to help establish the role of ultrasound-guided injection in the workup and care of patients presenting with both MRI findings and clinical findings of IFI.

Results of labral-level arthroscopic iliopsoas tenotomies for the treatment of labral impingement.

PURPOSE: To document the clinical results of arthroscopic iliopsoas tenotomies performed at the level of the labrum to treat labral injuries caused by iliopsoas impingement. METHODS: From a review of the database of the senior author (J.S.K.) of 300 hip arthroscopies that were performed between September 2009 and May 2011, 30 patients who had an arthroscopic release of the iliopsoas tendon at the level of the labrum and at least 2 years' follow-up were identified. In all cases the release was performed to treat a tight psoas tendon that was found at arthroscopy to be impinging on a torn or inflamed labrum. The results of hip arthroscopy in these patients were assessed with Byrd's 100-point modified Harris Hip Score system before arthroscopy and at 3, 6, 12, and 24 months after surgery. RESULTS: The mean age of the 30 patients was 35 years, and their preoperative scores averaged 43 points. After surgery, the patients had 6-month scores that averaged 73 points and 12-month scores that averaged 84 points (range, 40 to 100 points). Over the first postoperative year, in 3 of the 5 patients whose preoperative ultrasound imaging showed snapping of the tendon, recurrent painful snapping developed in the hip. All 3 had iliopsoas bursa injections and had immediate relief of their hip pain. In 2 patients the relief was temporary and an arthroscopic release of the tendon at the lesser trochanter was performed. The 2-year scores of the remaining 28 patients who did not have a second iliopsoas tenotomy averaged 88 points, and 23 of these patients had good or excellent results (scores ≥80 points). CONCLUSIONS: An arthroscopic release of the iliopsoas tendon at the level of the labrum was effective for alleviating hip pain from labral lesions caused by impingement of the tendon in 23 of 30 patients (77%). The remaining 7 patients had persistent hip pain and hip scores lower than 80 points because of recurrent snapping of the tendon (3), development of avascular necrosis (1), progression of degenerative joint disease (1), or chronic greater trochanteric bursitis (2). LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Ultrasound-guided corticosteroid injections for treatment of greater trochanteric pain syndrome: greater trochanter bursa versus subgluteus medius bursa.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of corticosteroid injections into the greater trochanteric bursa as opposed to the subgluteus medius bursa in patients with greater trochanteric pain syndrome. MATERIALS AND METHODS: We retrospectively reviewed 183 injections (149 performed in women, 34 performed in men; age range 23-90 years; median, 53 years) performed for treatment of greater trochanteric pain syndrome. A 10-cm visual analog scale survey was used to assess pain level before the procedure and 14 days after the procedure. A 3-mL corticosteroid solution was injected into either the greater trochanteric bursa or the subgluteus medius bursa under direct ultrasound guidance. Procedure images were retrospectively reviewed to determine the site of injection. Diagnostic images obtained at the time of the procedure were also reviewed for findings of tendinopathy, bursitis, and enthesopathy. Statistical analysis of differences in pain reduction was performed, as was analysis for association between pain relief and demographic variables of age, sex, previous injections, and ultrasound findings. RESULTS: Sixty-five injections met the inclusion criteria; 56 performed in women and nine performed in men (age range, 30-82 years; median, 53 years). Forty-one injections were into the greater trochanteric bursa and 24 into the subgluteus medius bursa. There was a statistically significant difference in pain reduction between greater trochanteric bursa and subgluteus medius bursa injections with a median pain reduction of 3 as opposed to 0 (p < 0.01). There was no statistically significant association between pain relief and demographic variables or ultrasound findings. CONCLUSION: Corticosteroid injections into the greater trochanteric bursa may be more effective than injections into the subgluteus medius bursa for treatment of greater trochanteric pain syndrome.

The analgesic impact of preoperative lumbar plexus blocks for hip arthroscopy. A retrospective review.

This study aimed to examine the impact of preoperative lumbar plexus blockade on perioperative analgesia and opioid consumption following hip arthroscopy. The records of patients (n = 236) who underwent hip arthroscopy between July 27, 2004 and November 15, 2009 were reviewed (118 patients with preoperative lumbar plexus block and 118 procedure matched patients without a preoperative block). Baseline patient characteristics were similar between groups. Immediate post-anaesthesia care unit (PACU) pain scores, peak PACU pain scores, perioperative opioid administration, and PACU antiemetic administration favoured preoperative block placement. Postoperative modified Harris Hip scores and postoperative day one pain scores were similar between groups. Total hospital time following the surgical procedure was longer in the block group. While preoperative lumbar plexus blockade may be helpful for analgesia following hip arthroscopy, more research needs to be done to determine the ideal analgesic regimen for these patients.

MR Appearance and Clinical Significance of Changes in the Hip Muscles and Iliopsoas Tendon After Arthroscopic Iliopsoas Tenotomy in Symptomatic Patients.

BACKGROUND: Iliopsoas tenotomy is a treatment for snapping hip. Does this surgical procedure change the surrounding muscle and tendon anatomy? QUESTIONS/PURPOSES: This study seeks to evaluate the changes in the MR appearance of the hip muscles and iliopsoas tendon in patients following arthroscopic iliopsoas tenotomy. METHODS: One hundred sixty-nine consecutive adults were evaluated after iliopsoas tenotomy at the lesser trochanter. Each MR exam was evaluated independently by three radiologists for muscle edema, atrophy (grade 0-4), compensatory hypertrophy, signal within the iliopsoas tendon (increased on T1 or T2 sequences), and iliopsoas tendon morphology (distorted or disrupted) above, at, and below the iliopectineal eminence. A finding was considered positive if reported by two or three of the radiologists. RESULTS: Twenty subjects met the inclusion criteria. Muscle edema was present in 15% (3/20) of subjects within the iliacus, psoas, and quadratus femoris. Atrophy was observed in the following muscles: iliacus 85% (17/20), psoas 75% (15/20), quadratus femoris 10% (2/20), rectus femoris 5% (1/20), vastus lateralis 5% (1/20), and gluteus maximus 25% (5/20). There was no compensatory hypertrophy. Ninety percent (18/20) had increased T1 and 10% (2/20) had increased T2 signal within the iliopsoas tendon. Thirty-five percent (7/20) of the iliopsoas tendons was disrupted and 85% (17/20) was distorted, most commonly below the iliopectineal eminence. CONCLUSION: The majority of postoperative symptomatic patients has atrophy of the iliacus and psoas muscles and distortion and disruption of the iliopsoas tendon and should be recognized as a normal imaging appearance following iliopsoas tendon release.

Imaging appearance of the normal and partially torn ligamentum teres on hip MR arthrography.

OBJECTIVE: The purpose of this study was to evaluate the MR arthrographic appearance of the normal and partially torn ligament teres and to determine if there are imaging criteria for diagnosing partial tears of the ligamentum teres. MATERIALS AND METHODS: One hundred sixteen patients underwent preoperative MR arthrography and hip arthroscopy. Each MR examination was evaluated independently by two musculoskeletal radiologists for the following: size and width of the ligamentum teres in the proximal, mid, and distal thirds of the ligamentum teres; overall length of the ligamentum; number of bundles (1-3); signal intensity (SI) within the ligamentum teres (low, intermediate, high); ligamentum teres fibers (normal, attenuated, thickened, wavy); ligamentum teres integrity (not torn, degenerated, frayed, partial tear); and femoral head edema at the ligamentum teres origin. Statistical analysis was performed using the Kruskal-Wallis rank sum test and Fisher exact test. RESULTS: Twelve of 116 (10%) subjects had partial ligamentum teres tears. One hundred four subjects had an intact ligamentum teres. The average size and width of the intact ligamentum teres was 12.6 × 4.38, 14.9 × 3.5, and 14.3 × 2.7 mm for proximal, mid, and distal, respectively, with an overall length 27.7 mm. It was most common to visualize two bundles in the proximal portion of the normal ligamentum teres (61 and 64/116). Low, intermediate, and high SI was common on all pulse sequences in normal and partially torn ligamentum teres for both readers (p = 0.33-0.84). For reader 1, there was no statistical difference between ligamentum teres fiber appearance in partial tears (p = 0.20). In contrast, reader 2 found partial tears associated with attenuated and wavy appearance (p = 0.003). Reader 1 diagnosed five of 12 (42%), and reader 2 diagnosed eight of 12 (67%) of the partial ligamentum teres tears (p = 0.47 and p = 0.0004). Edema of the femoral ligamentum teres origin was not associated with partial tears (p = 0.33-0.86). Retrospective review revealed that six partial tears had intra substance linear high SI on T2 images and peripheral irregularity, whereas four other tears had high SI within the ligamentum teres fibers without peripheral irregularity. CONCLUSION: The intact and partially torn ligamentum teres can have similar imaging findings on MR arthrography, making the diagnosis of partial ligamentum teres tears difficult. High SI within the substance of the fibers and irregularity suggest partial tearing; however, further research is warranted.

Labral injuries due to iliopsoas impingement: can they be diagnosed on MR arthrography?

OBJECTIVE: Iliopsoas impingement is a new arthroscopic diagnosis that refers to an anterior labral injury caused by the iliopsoas tendon. Currently, there are no preoperative criteria to establish the diagnosis of iliopsoas impingement. The goal of this study was to determine whether there are imaging criteria that would identify iliopsoas impingement on preoperative MR arthrography. MATERIALS AND METHODS: This study compared the preoperative MR arthrograms of 23 patients who had iliopsoas impingement diagnosed at hip arthroscopy with the arthrograms of 24 patients who did not have iliopsoas impingement found at hip arthroscopy. All of the arthroscopies were performed by a single orthopedic hip surgeon. In all cases of impingement, there was an isolated injury to the labrum at the 3-o'clock position. All were treated by arthroscopic iliopsoas tenotomy performed at the labral level. The MR examinations of the 47 patients were evaluated independently by two musculoskeletal radiologists who were blinded to the diagnosis. The following characteristics of the iliopsoas tendon at the level of the anterior labrum were evaluated: lateral dip, increased signal intensity (SI) between the iliopsoas tendon and labrum, irregularity of the deep margin of the iliopsoas tendon, edema within the iliopsoas tendon or capsule at the 3-o'clock position, presence of a labral tear at the 3-o'clock position, dimensions of the iliopsoas tendon, and location of iliopsoas tendon as it passed the labrum. Statistical analysis was performed using the Kruskal Wallis test, Fisher exact test, and Cohen kappa. Values for p less than 0.05 were considered significant. RESULTS: Nineteen women (mean age, 35 years) and four men (mean age, 36 years) had central iliopsoas impingement. Sixteen women (mean age, 38 years) and eight men (mean age, 35 years) did not have central iliopsoas impingement (p=0.318). For the impingement and nonimpingement groups, lateral dip of the iliopsoas tendon was seen in 15 of 23 (65%) and 17 of 24 (71%) for reader 1 and 18 of 23 (78%) and 11 of 24 (46%) for reader 2, respectively (p=0.76 and 0.036, respectively). There was no difference between the groups for increased SI between the iliopsoas tendon and labrum (p=0.38 and 0.82, respectively), irregular deep margin of the iliopsoas tendon (p=0.61 and 0.35, respectively), thickness of the iliopsoas tendon (p=0.33), or tendon or capsule edema (p=0.37 and 0.77, respectively). Reader 1 found 20 of 23 and reader 2 18 of 23 labral tears at the 3-o'clock position in the iliopsoas impingement group, with 13 of 24 and 10 of 24 in the non-iliopsoas impingement group respectively (p=0.024 and 0.017, respectively). The combined iliopsoas tendon width for both readers was 10.2 mm (range, 8.1-14.3 mm) in women and 11.9 mm (range, 11.1-13.4 mm) in men in the iliopsoas impingement group (p=0.0285), and 11.0 mm (range, 9.0-12.6 mm) for women and 11.8 mm (range, 8.7-15.1 mm) for men in the non-iliopsoas impingement group (p=0.159). The iliopsoas tendon most commonly crossed the labrum at the 3-o'clock position in both groups (p=0.83-0.17). CONCLUSION: An acetabular labral tear at the 3-o'clock position should suggest the diagnosis of iliopsoas impingement.

MR arthrographic appearance of the postoperative acetabular labrum in patients with suspected recurrent labral tears.

OBJECTIVE: The objective of our study was to evaluate the MR arthrographic appearance of the acetabular labrum in patients with a suspected recurrent acetabular labral tear after previous arthroscopic resection of a labral tear. CONCLUSION: The labrum after excision will appear shortened on MR arthrography. A recurrent labral tear can be diagnosed by the identification on MR arthrography of a new line to the labral surface, an enlarged and distorted labrum, or a new paralabral cyst.

MR arthrography of the hip: comparison of IDEAL-SPGR volume sequence to standard MR sequences in the detection and grading of cartilage lesions.

PURPOSE: To compare the diagnostic performance of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)-spoiled gradient-recalled echo (SPGR) with that of standard magnetic resonance (MR) arthrography sequences for detecting and grading cartilage lesions within the hip joint during MR arthrography. MATERIALS AND METHODS: Following institutional review board approval, 67 consecutive hip MR arthrograms were retrospectively reviewed independently by three musculoskeletal radiologists and one musculoskeletal fellow. IDEAL-SPGR images and the two-dimensional images, the latter from the routine MR arthrography protocol, were evaluated at separate sittings to grade each articular surface of the hip joint. By using arthroscopy as the reference standard, the sensitivity and specificity of the two techniques for detecting and grading cartilage lesions were determined. The McNemar test was used to compare diagnostic performance. Interreader agreement was calculated using Fleiss κ values. RESULTS: For all readers and surfaces combined, the sensitivity and specificity for detecting cartilage lesions was 74% and 77%, respectively, for IDEAL-SPGR and 70% and 84%, respectively, for the routine MR arthrography protocol. IDEAL-SPGR had similar sensitivity (P = .12) to and significantly lower specificity (P < .001) than the routine MR arthrography protocol for depicting cartilage lesions. When analyzing the differences in sensitivity and specificity by reader, the two readers who had experience with IDEAL-SPGR had no significant difference in sensitivity and specificity for detecting cartilage lesions between the two sequences. For all readers and surfaces combined, IDEAL-SPGR had a higher accuracy in correctly grading cartilage lesion (P = .012-.013). Interobserver agreement for detecting cartilage lesions did not differ between the two techniques. CONCLUSION: IDEAL-SPGR had similar sensitivity and significantly lower specificity for detecting cartilage lesions and higher accuracy for grading cartilage lesions than did a routine MR arthrography protocol; the lower specificity of IDEAL-SPGR for detecting cartilage lesions was not seen in experienced readers.

Cross-sectional analysis of iliopsoas muscle-tendon units at the sites of arthroscopic tenotomies: an anatomic study.

BACKGROUND: Arthroscopic iliopsoas tenotomies are performed at the level of the labrum, femoral neck, and lesser trochanter. The composition and percentage of the iliopsoas muscle-tendon unit (MTU) that is released when the tendon is cut at these sites has not been reported to date. HYPOTHESIS: Cutting the iliopsoas tendon at the 3 common sites of arthroscopic tenotomies does not release the entire iliopsoas MTU. STUDY DESIGN: Descriptive laboratory study. METHODS: Forty iliopsoas MTUs from 20 embalmed cadavers were isolated at the level of the hip joint and released from their insertion on the lesser trochanter. Circumferential measurements of the composite MTU and the isolated iliopsoas tendon were then made at (1) the MTU's insertion on the lesser trochanter, (2) the Wettstein et al site of transcapsular release, and (3) the Alpert et al release site at the level of the labrum. Single proportion testing was performed using the Student t test to determine if significant differences existed between the average circumference of the iliopsoas MTUs or the isolated tendons at the 3 levels at which they were measured. RESULTS: The average circumference of the iliopsoas-muscle belly complex at the level of the labrum, the transcapsular release site, and the lesser trochanter was 68, 58, and 46 mm, respectively. The average circumference of the iliopsoas tendon at these same levels was 27, 31, and 27 mm, respectively. Thus, at the level of the labrum, transcapsular release site, and lesser trochanter, the iliopsoas MTU is composed of 40% tendon/60% muscle belly, 53% tendon/47% muscle belly, and 60% tendon/40% muscle belly, respectively. CONCLUSION: Cutting the iliopsoas tendon at the labrum, head-neck junction, or lesser trochanter does not result in a release of the entire iliopsoas MTU. CLINICAL RELEVANCE: The results of this study document that releasing the iliopsoas tendon at the lesser trochanter preserves 40% of the MTU and does not result in a complete detachment of the iliopsoas MTU.

Do iatrogenic punctures of the labrum affect the clinical results of hip arthroscopy?

PURPOSE: To document the effect of iatrogenic labral punctures (ILPs) on the clinical results of hip arthroscopy. METHODS: From a database of 250 consecutive patients who had their hip arthroscopy performed by the senior author, 50 patients with ILPs were identified. Results of hip arthroscopy in these patients were compared with those of a matched group of 50 patients who did not have labral puncture (NLP). All hips were assessed with Byrd's 100-point modified Harris hip scoring system before arthroscopy and at 3, 6, 12, and 24 months after surgery. RESULTS: The mean age of the ILP and NLP patients was 40 and 36 years, respectively, and their preoperative scores averaged 36 points. Mean joint distraction was 13 mm and 15 mm in the ILP and NLP patients, respectively, and a positive "Byrd's sign" was seen in both the ILP (84%) and NLP (42%) patients. After surgery, the ILP and NLP patients had 6-month scores that averaged 85 and 88 points, respectively. At 12 months, their scores averaged 88 and 90 points, respectively, and after 24 months, their scores averaged 88 and 89 points, respectively. At all follow-up intervals, there were no significant differences between the scores of the 2 groups (P > .05). CONCLUSIONS: ILPs did not affect the 1- and 2-year clinical results of patients who sustained these injuries during hip arthroscopy. LEVEL OF EVIDENCE: Level III, case-control study.