Multi-vendor multi-site quantitative MRI analysis of cartilage degeneration 10 Years after anterior cruciate ligament reconstruction: MOON-MRI protocol and preliminary results.

OBJECTIVE: To describe the protocol of a multi-vendor, multi-site quantitative MRI study for knee post-traumatic osteoarthritis (PTOA), and to present preliminary results of cartilage degeneration using MR T1ρ and T2 imaging 10 years after anterior cruciate ligament reconstruction (ACLR). DESIGN: This study involves three sites and two MR platforms. The patients are from a nested cohort (termed as Onsite cohort) within the Multicenter Orthopaedic Outcomes Network (MOON) cohort 10 years after ACLR. Phantoms and controls were scanned for evaluating reproducibility. Cartilage was automatically segmented, and T1ρ and T2 were compared between operated, contralateral, and control knees. RESULTS: Sixty-eight ACL-reconstructed patients and 20 healthy controls were included. In phantoms, the intra-site coefficients of variation (CVs) of repeated scans ranged 1.8-2.1% for T1ρ and 1.3-1.7% for T2. The inter-site CVs ranged 1.6-2.1% for T1ρ and 1.1-1.4% for T2. In human subjects, the intra-site scan/rescan CVs ranged 2.2-3.5% for T1ρ and 2.6-4.9% for T2 for the six major compartments. In patients, operated knees showed significantly higher T1ρ and T2 values mainly in medial femoral condyle, medial tibia and trochlear cartilage compared with contralateral knees, and showed significantly higer T1ρ and T2 values in all six compartments compared to healthy control knees. The patient contralateral knees showed higher T1ρ and T2 values mainly in the lateral femoral condyle, lateral tibia, trochlear, and patellar cartilage compared to healthy control knees. CONCLUSION: A platform and workflow with rigorous quality control has been established for a multi-vendor multi-site quantitative MRI study in evaluating PTOA 10 years after ACLR. Our preliminary report suggests significant cartilage matrix changes in both operated and contralateral knees compared with healthy control knees.

32nd International Austrian Winter Symposium : Zell am See, the Netherlands. 20-23 January 2016.

TABLE OF CONTENTS: A1 68Ga-PSMA PET/CT in staging and restaging of Prostate Cancer Patients: comparative study with 18F-Choline PET/CTW Langsteger, A Rezaee, W Loidl, HS Geinitz, F Fitz, M Steinmair, G Broinger, L Pallwien-Prettner, M BeheshtiA2 F18 Choline PET - CT: an accurate diagnostic tool for the detection of parathyroid adenoma?L Imamovic, M Beheshti, G Rendl, D Hackl, O Tsybrovsky, M Steinmair, K Emmanuel, F Moinfar, C Pirich, W LangstegerA3 [18F]Fluoro-DOPA-PET/CT in the primary diagnosis of medullary thyroid carcinomaA Bytyqi, G Karanikas, M Mayerhöfer, O Koperek, B Niederle, M HartenbachA4 Variations of clinical PET/MR operations: An international survey on the clinical utilization of PET/MRIT Beyer, K Herrmann, J CzerninA5 Standard Dixon-based attenuation correction in combined PET/MRI: Reproducibility and the possibility of Lean body mass estimationI Rausch, P Rust, MD DiFranco, M Lassen, A Stadlbauer, ME Mayerhöfer, M Hartenbach, M Hacker, T BeyerA6 High resolution digital FDG PET/MRI imaging for assessment of ACL graft viabilityK Binzel, R Magnussen, W Wei, MU Knopp, DC Flanigan, C Kaeding, MV KnoppA7 Using pre-existing hematotoxicity as predictor for severe side effects and number of treatment cycles of Xofigo therapyA Leisser, M Nejabat, M Hartenbach, G Kramer, M Krainer, M Hacker, A HaugA8 QDOSE - comprehensive software solution for internal dose assessmentWencke Lehnert, Karl Schmidt, Sharok Kimiaei, Marcus Bronzel, Andreas KlugeA9 Clinical impact of Time-of-Flight on next-generation digital PET imaging of Yttrium-90 radioactivity following liver radioembolizationCL Wright, K Binzel, J Zhang, Evan Wuthrick, Piotr Maniawski, MV KnoppA10 Snakes in patients! Lessons learned from programming active contours for automated organ segmentationM Blaickner, E Rados, A Huber, M Dulovits, H Kulkarni, S Wiessalla, C Schuchardt, RP Baum, B Knäusl, D GeorgA11 Influence of a genetic polymorphism on brain uptake of the dual ABCB1/ABCG2 substrate [11C]tariquidarM Bauer, B Wulkersdorfer, W Wadsak, C Philippe, H Haslacher, M Zeitlinger, O LangerA12 Outcome prediction of temporal lobe epilepsy surgery from P-glycoprotein activity. Pooled analysis of (R)-[11C]-verapamil PET data from two European centresM Bauer, M Feldmann, R Karch, W Wadsak, M Zeitlinger, MJ Koepp, M-C Asselin, E Pataraia, O LangerA13 In-vitro and in-vivo characterization of [18F]FE@SNAP and derivatives for the visualization of the melanin concentrating hormone receptor 1M Zeilinger, C Philippe, M Dumanic, F Pichler, J Pilz, M Hacker, W Wadsak, M MitterhauserA14 Reducing time in quality control leads to higher specific radioactivity of short-lived radiotracersL Nics, B Steiner, M Hacker, M Mitterhauser, W WadsakA15 In vitro 11C-erlotinib binding experiments in cancer cell lines with epidermal growth factor receptor mutationsA Traxl, Thomas Wanek, Kushtrim Kryeziu, Severin Mairinger, Johann Stanek, Walter Berger, Claudia Kuntner, Oliver LangerA16 7-[11C]methyl-6-bromopurine, a PET tracer to measure brain Mrp1 function: radiosynthesis and first PET evaluation in miceS Mairinger, T Wanek, A Traxl, M Krohn, J Stanek, T Filip, M Sauberer, C Kuntner, J Pahnke, O LangerA17 18F labeled azidoglucose derivatives as "click" agents for pretargeted PET imagingD Svatunek, C Denk, M Wilkovitsch, T Wanek, T Filip, C Kuntner-Hannes, J Fröhlich, H MikulaA18 Bioorthogonal tools for PET imaging: development of radiolabeled 1,2,4,5-TetrazinesC Denk, D Svatunek, T Wanek, S Mairinger, J Stanek, T Filip, J Fröhlich, H Mikula, C Kuntner-HannesA19 Preclinical evaluation of [18F]FE@SUPPY- a new PET-tracer for oncologyT Balber, J Singer, J Fazekas, C Rami-Mark, N Berroterán-Infante, E Jensen-Jarolim, W Wadsak, M Hacker, H Viernstein, M MitterhauserA20 Investigation of Small [18F]-Fluoroalkylazides for Rapid Radiolabeling and In Vivo Click ChemistryC Denk, D Svatunek, B Sohr, H Mikula, J Fröhlich, T Wanek, C Kuntner-Hannes, T FilipA21 Microfluidic 68Ga-radiolabeling of PSMA-HBED-CC using a flow-through reactorS Pfaff, C Philippe, M Mitterhauser, M Hartenbach, M Hacker, W WadsakA22 Influence of 24-nor-ursodeoxycholic acid on hepatic disposition of [18F]ciprofloxacin measured with positron emission tomographyT Wanek, E Halilbasic, M Visentin, S Mairinger, B Stieger, C Kuntner, M Trauner, O LangerA23 Automated 18F-flumazenil production using chemically resistant disposable cassettesP Lam, M Aistleitner, R Eichinger, C ArtnerA24 Similarities and differences in the synthesis and quality control of 177Lu-DOTA-TATE, 177Lu -HA-DOTA-TATE and 177Lu-DOTA-PSMA (PSMA-617)H Eidherr, C Vraka, A Haug, M Mitterhauser, L Nics, M Hartenbach, M Hacker, W WadsakA25 68Ga- and 177Lu-labelling of PSMA-617H Kvaternik, R Müller, D Hausberger, C Zink, RM AignerA26 Radiolabelling of liposomes with 67Ga and biodistribution studies after administration by an aerosol inhalation systemU Cossío, M Asensio, A Montes, S Akhtar, Y te Welscher, R van Nostrum, V Gómez-Vallejo, J LlopA27 Fully automated quantification of DaTscan SPECT: Integration of age and gender differencesF VandeVyver, T Barclay, N Lippens, M TrochA28 Lesion-to-background ratio in co-registered 18F-FET PET/MR imaging - is it a valuable tool to differentiate between low grade and high grade brain tumor?L Hehenwarter, B Egger, J Holzmannhofer, M Rodrigues-Radischat, C PirichA29 [11C]-methionine PET in gliomas - a retrospective data analysis of 166 patientsN Pötsch, I Rausch, D Wilhelm, M Weber, J Furtner, G Karanikas, A Wöhrer, M Mitterhauser, M Hacker, T Traub-WeidingerA30 18F-Fluorocholine versus 18F-Fluorodeoxyglucose for PET/CT imaging in patients with relapsed or progressive multiple myeloma: a pilot studyT Cassou-Mounat, S Balogova, V Nataf, M Calzada, V Huchet, K Kerrou, J-Y Devaux, M Mohty, L Garderet, J-N TalbotA31 Prognostic benefit of additional SPECT/CT in sentinel lymph node mapping of breast cancer patientsS Stanzel, G Pregartner, T Schwarz, V Bjelic-Radisic, B Liegl-Atzwanger, R AignerA32 Evaluation of diagnostic value of TOF-18F-FDG PET/CT in patients with suspected pancreatic cancerS Stanzel, F Quehenberger, RM AignerA33 New quantification method for diagnosis of primary hyperpatahyroidism lesions and differential diagnosis vs thyropid nodular disease in dynamic scintigraphyA Koljevic Markovic, Milica Jankovic, V Miler Jerkovic, M Paskas, G Pupic, R Dzodic, D PopovicA34 A rare case of diffuse pancreatic involvement in patient with merkel cell carcinoma detected by 18F-FDGMC Fornito, D FamiliariA35 TSH-stimulated 18F-FDG PET/CT in the diagnosis of recurrent/metastatic radioiodine-negative differentiated thyroid carcinomas in patients with various thyroglobuline levelsP Koranda, H Polzerová, I Metelková, L Henzlová, R Formánek, E Buriánková, M KamínekA36 Breast Dose from lactation following I131 treatmentWH Thomson, C LewisA37 A new concept for performing SeHCAT studies with the gamma cameraWH Thomson, J O'Brien, G James, A NotghiA38 Whole body F-18-FDG-PET and tuberculosis: sensitivity compared to x-ray-CTH Huber, I Stelzmüller, R Wunn, M Mandl, F Fellner, B Lamprecht, M GabrielA39 Emerging role 18F-FDG PET-CT in the diagnosis and follow-up of the infection in heartware ventricular assist system (HVAD)MC Fornito, G LeonardiA40 Validation of Poisson resampling softwareWH Thomson, J O'Brien, G JamesA41 Protection of PET nuclear medicine personnel: problems in satisfying dose limit requirementsJ Hudzietzová, J Sabol, M Fülöp.

KOOS pain as a marker for significant knee pain two and six years after primary ACL reconstruction: a Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort study.

OBJECTIVE: The prevalence of radiographic osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) approaches 50%, yet the prevalence of significant knee pain is unknown. We applied three different models of Knee injury and Osteoarthritis Outcome Score (KOOS) thresholds for significant knee pain to an ACLR cohort to identify prevalence and risk factors. DESIGN: Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort patients with a unilateral primary ACLR and normal contralateral knee were assessed at 2 and 6 years. Independent variables included patient demographics, validated Patient Reported Outcomes (PRO; Marx activity score, KOOS), and surgical characteristics. Models included: (1) KOOS criteria for a painful knee = quality of life subscale <87.5 and ≥2 of: KOOSpain <86.1, KOOSsymptoms <85.7, KOOSADL <86.8, or KOOSsports/rec <85.0; (2) KOOSpain subscale score ≤72 (≥2 standard deviations below population mean); (3) 10-point KOOSpain drop from 2 to 6 years. Proportional odds models (alpha ≤ 0.05) were used. RESULTS: 1761 patients of median age 23 years, median body mass index (BMI) 24.8 kg/m(2) and 56% male met inclusion, with 87% (1530/1761) and 86% (1506/1761) follow-up at 2 and 6 years, respectively. At 6 years, n = 592 (39%), n = 131 (9%) and n = 169 (12%) met criteria for models #1 through #3, respectively. The most consistent and strongest independent risk factor at both time-points was subsequent ipsilateral knee surgery. Low 2-year Marx activity score increased the odds of a painful knee at 6 years. CONCLUSIONS: Significant knee pain is prevalent after ACLR; with those who undergo subsequent ipsilateral surgery at greatest risk. The relationship between pain and structural OA warrants further study.

Meniscus treatment and age associated with narrower radiographic joint space width 2-3 years after ACL reconstruction: data from the MOON onsite cohort.

OBJECTIVE: To identify risk factors for radiographic signs of post-traumatic osteoarthritis (OA) 2-3 years after anterior cruciate ligament (ACL) reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort. METHODS: A nested cohort within the Multicenter Orthopaedic Outcomes Network (MOON) cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors. RESULTS: Unexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96-5.15 mm) vs 4.71 mm (95% CI 4.62-4.80 mm), P < 0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38-0.90 mm) (P < 0.001). Age (P < 0.001) and meniscus repair (P = 0.001) were also significantly associated with mJSW difference. CONCLUSION: Semi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2-3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study.

Running injuries about the knee.

Evaluation and treatment recommendations for a painful knee in a runner can be accomplished with a good knowledge of knee pathology, careful physical exam, and appropriate use of imaging tests. Most knee problems in a runner fall into one of the entities listed above. Fortunately, almost all can expect significant improvement with appropriate treatment.

Neuromuscular differences between male and female athletes.

Female athletes who participate in jumping and cutting-type sports have a four- to six-fold higher incidence of serious knee injuries compared with male athletes in the same sports. Many of these injuries involve the anterior cruciate ligament, and occur by non-contact mechanisms. The susceptibility of the female athlete's knee to injury is likely multifactorial, although neuromuscular factors seem to have an important role. Recent studies have identified neuromuscular differences between male and female athletes. Specifically, female athletes have decreased stiffness and decreased potential for dynamic stabilization of the knee joint. Proprioception deficits involving the knee and side-to-side strength and coordination imbalances are more frequent in female athletes. Also, female athletes more commonly demonstrate imbalances in strength, timing of activation, and recruitment patterns of the lower extremity muscles. Based on these findings, neuromuscular training programs have been studied in an effort to correct lower extremity neuromuscular imbalances. Preliminary results from these programs have been encouraging in reducing peak landing imact forces in the knee, correcting strength and proprioception deficits, and ultimately in decreasing the incidence of serious knee injuries in female athletes.

Upper extremity stress fractures in athletes: clinical features of 44 cases.

PURPOSE: To review the clinical features of a large series of active patients with a stress fracture in a non-weight-bearing location of the upper extremity or ribs. DESIGN: Multicenter cross-sectional study. SETTING: Multiple academic medical centers. PARTICIPANTS: 44 patients with a diagnosis of upper extremity or rib stress fracture. MAIN OUTCOME MEASURES: Clinical features according to anatomic location, primary sport, and subdivided according to the nature of the sport-specific skills involved. RESULTS: A diagnosis of stress fracture was made in 44 patients based on history and physical examination, and confirmed by radiography, scintigraphy, magnetic resonance imaging (MRI), computed tomography (CT), or a combination of imaging techniques. Patients were subjectively divided into four categories based on the predominant type of upper extremity activity required for participation in their sport: 1) weight lifter (e.g., football, weight lifting, wrestling); 2) upper extremity weight bearer (e.g., gymnastics, diving, cheerleading); 3) thrower (e.g., pitcher, soccer goalie, javelin); or 4) swinger (e.g., golf, tennis). We noted that all fractures in the weight bearers occurred distal to the elbow, whereas in the throwers most fractures affected the shoulder girdle. Lower rib stress fractures predominated in the swingers group, whereas weight lifters had fractures located throughout the upper extremity. CONCLUSION: Stress fracture should be considered in the differential diagnosis of athletes presenting with upper extremity or rib pain of bony origin that is of insidious onset. Further study of the sport-specific patterns of injury described here may improve our ability to treat and prevent these injuries.

The value of intercondylar notch visualization of the posteromedial and posterolateral compartments during knee arthroscopy.

The intercondylar notch views allow for visualization of the posteromedial and posterolateral compartments of the knee without the use of accessory portals. The purpose of this study was to prospectively evaluate whether these views are useful either diagnostically or therapeutically in the performance of knee arthroscopy. Two surgeons at one institution performed 150 consecutive knee arthroscopies. After arthroscopic examination of the knee using standard portals, a diagnosis and treatment decisions were made. Thereafter, visualization of the posteromedial and posterolateral compartments through the intercondylar notch was undertaken. Each view was performed initially with a 30 degrees arthroscope and 3 questions were asked: (1) Did the view change the diagnosis or add additional information? (2) Did it change the surgical treatment? (3) Was it useful during performance of the procedure? The 70 degrees arthroscope was then used and the same three questions were addressed. In 20.6% of the cases, the intercondylar notch views made a diagnostic and/or therapeutic difference, and the surgical procedure was changed in 11.3% based solely on this information. The views were 3 times as likely to make a difference in anterior cruciate ligament (ACL) reconstructions when compared with arthroscopy without ACL reconstruction (P <.01). The 70 degrees arthroscope added nominal additional information. There were no significant complications. We advocate visualization of the posteromedial and posterolateral compartments through the intercondylar notch as a valuable part of routine knee arthroscopy.

The plantar fasciotomy: MR imaging findings in asymptomatic volunteers.

OBJECTIVE: To determine the postoperative appearance of the plantar fascia on MR imaging after a fasciotomy has been performed, and to compare the postsurgical appearance of the fascia after an open and endoscopic procedure. DESIGN AND PATIENTS: Fifteen asymptomatic volunteers (12 women, 3 men; age range 22-49 years, mean age 33 years) with prior fasciotomies for treatment of longstanding plantar fasciitis were studied. Fourteen volunteers had a unilateral release and one volunteer had bilateral releases, allowing for assessment of 16 ankles. Eight fasciotomies were performed through an open incision and eight were performed endoscopically. The average time between surgery and imaging was 24 months (range 11-46 months). The site of surgery was established from the operative reports. Proton density (PD)-weighted and T2-weighted images in three orthogonal planes were obtained on a 1.5-T magnet. In eight studies, T1-weighted sagittal and STIR sagittal images were included. The fascia in each ankle was assessed for morphology and signal intensity. Perifascial soft tissues and bone marrow were assessed for edema. Preoperative MR studies were available in five volunteers. RESULTS: There was no apparent difference in the postoperative appearance of the ankle after an open or endoscopic procedure except for scar formation in the subcutaneous fat which was common after an open procedure (P<0.05). Three ankles had a gap in the fascia (one open, two endoscopic). The plantar fascia measured a mean of 7.0 mm (range 5-10 mm) at the fasciotomy, and 8.3 mm (range 6-12 mm) at the enthesis. At the fasciotomy, 11 of 13 ankles had an indistinct deep contour and 9 of 13 had an indistinct superficial contour. At the enthesis, 13 of 16 ankles had an indistinct deep contour and 6 of 16 had an indistinct superficial contour. Compared with preoperative MR studies there was an average reduction in the fascial thickness at the enthesis of 14% (range 9-20%), but the thickness at the fasciotomy nearly doubled. No edema was evident in the fascia, perifascial tissues, deep plantar muscles, or calcaneal bone marrow. CONCLUSIONS: The average thickness of the plantar fascia in asymptomatic volunteers after surgery is nearly 2-3 times that of normal. While there is increased thickness at the site of surgery, the changes in morphology and signal intensity were most prominent at the enthesis. The key observation was absence of edema in the fascia and perifascial soft tissues. This baseline information may be of value when assessing MR studies of symptomatic patients.

A comparison of ketorolac tromethamine/oxycodone versus patient-controlled analgesia with morphine in anterior cruciate ligament reconstruction patients.

Effective postoperative analgesia with minimal side effects remains an important goal in enabling increasingly complex surgical procedures to be performed on an outpatient basis. In this study, we examined the efficacy of postoperative analgesia in 90 patients undergoing anterior cruciate ligament reconstruction using a patellar tendon autograft, with a 24-hour hospital stay. Patients were randomized to receive either intramuscular ketorolac supplemented by oral oxycodone, or intravenous morphine via patient-controlled analgesia (PCA) device, for postoperative analgesia. Patients were monitored for 2 hours in the recovery room, then every 4 hours until discharge, for the presence of complications of nausea, vomiting, urinary retention, pruritus, and dizziness. Pain was assessed using a visual analog scale (VAS) on the morning of postoperative day one. All patients were discharged by 24 hours after surgery. Ten (20%) of the patients receiving ketorolac/oxycodone versus 31 (79%) of those receiving PCA morphine experienced postoperative complications (P < .05). Postoperative nausea, vomiting, and urinary retention were each significantly more common in the PCA morphine group (P < .05). The incidence of pruritus and dizziness was low overall. There was no significant difference between groups in the severity of postoperative pain as assessed using a VAS. We conclude that ketorolac/oxycodone may provide comparable analgesia with fewer undesirable side effects than PCA morphine in patients undergoing anterior cruciate ligament reconstruction. Patients receiving ketorolac/oxymorphone may have a better quality recovery and more rapid discharge.

Anti-inflammatory effects of topically applied dimethyl sulfoxide gel on endotoxin-induced synovitis in horses.

OBJECTIVE: To evaluate the effect of topically applied dimethylsulfoxide (DMSO) on lipopolysaccharide (LPS)-induced synovitis in the mid-carpal joint. ANIMALS: 6 sound, healthy, adult horses (12 carpi). PROCEDURE: In a double-blinded, crossover, paired study with a 1-week washout period, mid-carpal joints were allocated to group 1 (DMSO, n = 6) or group 2 (control, n = 6). Each joint was injected with 1.3 ml (0.0125 ng/dl) of LPS to induce synovitis. For group-1 joints, DMSO gel (15 g; 90%) was applied after injection of LPS and at 12-hour intervals for 60 hours. Joints of group 2 received LPS, but not DMSO gel. All horses were evaluated by serial lameness examinations and synovial fluid analyses (total and differential WBC count and total protein concentration) at 12-hour intervals for 60 hours after LPS injection. Plasma and synovial fluid were obtained at baseline and 36 hours to document presence of DMSO. RESULTS: Mean WBC concentration was significantly (P < 0.05) lower in group-1, compared with group-2 joints, at 24 hours and had a trend to be lower at 36 hours. Mean total neutrophil count was significantly lower in group-1, compared with group-2 joints at 24 hours. In group-1 joints, DMSO was detected by use of gas chromatography in the synovial fluid of 5 of 6 joints and in plasma from 1 of 6 horses. CONCLUSION: Topically applied DMSO penetrated into synovial fluid in sufficient quantities to be detected and to decrease joint inflammation.

Musculoskeletal injuries in adolescents.

This article reviews the anatomy of the physis and the most common classification of injuries or fractures through the physis. The common apophyseal injuries of Osgood-Schlatter, Severs disease and iliac apophysitis, are reviewed in addition to a review of the most common osteochondritides, including Panner's disease and Osteochondritis Dessicans of the femur and talus. An understanding of these is key to diagnosis and treatment of adolescent musculoskeletal injuries. This article also reviews slipped capital femoral epiphysis, little leaguer's elbow, anterior cruciate and collateral ligament injuries, patella problems, ankle sprains and several common fractures in children.

Meniscal flounce MR imaging.

PURPOSE: To determine the prevalence of a meniscal flounce, the magnetic resonance (MR) imaging characteristics, and whether the flounce is associated with a meniscal tear. MATERIALS AND METHODS: Knee MR images obtained in 3,159 examinations over 2 years were prospectively evaluated. Ten adult patients (six with true flounces, four with flouncelike folds associated with meniscal tears) with an S-shaped fold in the free edge of a meniscus on sagittal images were included. Five underwent arthroscopic surgery. RESULTS: The prevalence of a flounce was 0.2% (six of 3,159 examinations). Five occurred in the medial meniscus (MM) and one occurred in the lateral meniscus (LM). All appeared truncated in the coronal plane. Four meniscal tears also demonstrated flouncelike folds. Three were confirmed with surgery and one was confirmed with clinical findings. Of the 3,159 MR examinations, 1,151 demonstrated an MM tear, 832 an LM tear, 542 MM degeneration, and 270 LM degeneration. CONCLUSION: A meniscal flounce is a fold that occurs in the absence of a tear, and presence of it does not increase the prevalence of a tear. Because tears may result in a flouncelike fold, a flounce should be considered a normal variant only in the absence of other indications of a meniscal tear.

Recalcitrant patellar tendinitis. Magnetic resonance imaging, histologic evaluation, and surgical treatment.

Magnetic resonance imaging findings and the results of surgical treatment and histologic evaluation of 11 knees in 9 athletes with recalcitrant patellar tendinitis are reported. All of the athletes had no improvement with traditional nonoperative treatment and all had abnormal magnetic resonance imaging findings consistent with chronic patellar tendinitis. Surgical exploration and debridement were performed on the 11 knees by the same surgeon. With a minimum followup of 1 year, 7 of the 11 knees had excellent results, 3 had good results, and 1 had a poor result. Histologic evaluation of the debrided tissue was consistent with "angiofibroblastic tendinosis," which correlated with the abnormal preoperative magnetic resonance imaging findings in the proximal third of the infrapatellar tendon. This study correlated histologic findings with magnetic resonance imaging findings and shows that in selected patients excellent results can be achieved with surgical treatment of recalcitrant patellar tendinitis or "jumper's knee."

Bilateral acute-on-chronic exertional lateral compartment syndrome of the leg: a case report and review of the literature.

PURPOSE: We report a previously undescribed case of bilateral acute exertional compartment syndrome of the lateral compartment arising from pre-existing chronic exertional compartment syndromes. CASE SUMMARY: A 21-year-old football player had a 1-year history of bilateral chronic exertional compartment syndrome. One day after practice his usual symptoms progressed instead of abated and he presented at 3:00 AM with bilateral acute lateral compartment syndromes. His lateral compartment pressures were > 100 mm Hg. Emergency surgical releases were performed and the patient recovered well with full return to competitive football in 4 weeks. DISCUSSION: No prior case of acute-on-chronic exertional compartment syndrome of the lateral compartment has been reported. In addition, this is a case of bilateral acute exertional compartment syndrome. The literature is reviewed with discussion of differential diagnosis, distribution, pathophysiology, and treatment of exertional compartment syndrome. RELEVANCE: Failure to recognize and emergently treat progression of a chronic to an acute exertional compartment syndrome can be devastating.

Correlation of MR imaging and pathologic findings in athletes undergoing surgery for chronic patellar tendinitis.

OBJECTIVE: Jumper's knee, or chronic patellar tendinitis, can be a source of considerable pain in athletes. The changes that occur with shearing of the tendinous fibers from repeated microtrauma can progress to significant degeneration and increase the risk of tendon rupture. In order to better understand this phenomenon, a correlative study relating the MR imaging and pathologic findings was performed. SUBJECTS AND METHODS: Nine high-performance athletes 18-22 years old (mean age, 20 years) underwent operation of 11 knees for long-standing jumper's knee. The average period of symptoms was 3 years (range, 2 to 6 years). MR knee examinations were performed before surgery in all athletes. The symptoms, MR findings, and pathological findings were correlated. RESULTS: There was focal thickening in the proximal one third of the patellar tendon (range, 9-16 mm; mean, 12 mm) in all 11 knees, involving the medial portion of the tendon in 10 and the center in one. On proton-density-weighted MR images, all knees demonstrated a focus of abnormal signal intensity in the proximal one third of the patellar tendon. On T2-weighted MR images, 10 knees demonstrated abnormal signal intensity; eight were isointense to that seen on proton-density-weighted images, and two were relatively hyperintense. Ten tendons demonstrated a poorly defined posterior margin. Pathologically, the areas of abnormal signal intensity corresponded to tissue containing tenocyte hyperplasia, prominent angiogenesis with endothelial hyperplasia, loss of longitudinal collagenous architecture, and microtears with collagen fiber separation. Hyaline degeneration was present in specimens from every patient. CONCLUSION: In athletes with chronic patellar tendinitis, areas of abnormal signal intensity on MR imaging corresponded to degenerative pathologic changes consistent with angiofibroblastic tendinosis. In nearly all patients, the tendon thickening occurred eccentrically. Disproportionate medial tendon thickening may be related to unequal tensile forces across the knee joint, resulting in greater stress on the medial portion of the extensor mechanism of the knee.

Bilateral discoid medial menisci with extensive intrasubstance cleavage tears: MRI and arthroscopic correlation.

Although rare, the discoid meniscus can become problematic in active individuals. The arthroscopist is then presented with a challenging treatment problem. Through the current techniques of arthroscopy and MRI, the diagnostic and treatment difficulties are lessened; however, our understanding of the discoid meniscus is incomplete. Currently, the need exists for correlation between arthroscopy and MRI. We present a case of bilateral complete discoid medial menisci with symptomatic extensive intrasubstance horizontal cleavage tears. Both arthroscopy and MRI views of the lesions, pre- and postoperative, are presented. A review and discussion of the literature is included.

Bupivacaine use after knee arthroscopy: pharmacokinetics and pain control study.

Bupivacaine (Marcaine) pharmacokinetics were determined in 11 patients receiving the drug intraarticularly after arthroscopic procedures performed on the knee with patients under general anesthesia. Forty milliliters of 0.25% bupivacaine (100 mg) were given as a bolus into the intraarticular space of the knee of each patient. The thigh tourniquet was released 2-3 min after injection and blood samples were obtained 5, 10, 15, 20, 30, 60, 120, 180, 250, and 300 min after tourniquet release. Pharmacokinetic parameters obtained were (mean +/- SD): Vd beta 206 +/- 88 L; Cle 0.816 +/- 0.378 L/min; t 1/2 beta 189 +/- 84 min; ka 9.92 +/- 6.79 x 10/min; Cpmax 0.48 +/- 0.20 micrograms/ml; and tmax 43.4 +/- 23.1 min. Correlations between higher peak plasma concentrations and longer tourniquet times (p = 0.02) and shorter intervals from injection to tourniquet deflation (p = 0.03) were found using multiple linear regression. Our results indicate that injections of 100 mg of bupivacaine intraarticularly after knee arthroscopy will produce peak blood levels within the 1st h after surgery and that these levels will be well below those noted to produce toxic reactions. Peak levels can be minimized with shorter tourniquet inflation times and with longer injection to tourniquet release intervals. Ninety healthy adult outpatient knee arthroscopy patients also were studied to evaluate the effectiveness of bupivacaine in relieving postoperative knee discomfort when injected immediately postoperatively. The subjects were randomized into four groups: (a) intraarticular injection of saline, (b) intraarticular injection of bupivacaine, (c) subcutaneous injection of bupivacaine at the portal sites, and (d) both intraarticular and subcutaneous injection of bupivacaine.(ABSTRACT TRUNCATED AT 250 WORDS)

The pharmacokinetics of bupivacaine when injected intra-articularly after knee arthroscopy.

Bupivacaine pharmacokinetics were determined in 11 patients receiving the drug intra-articularly after knee arthroscopy performed under general anesthesia. Forty ml 0.25% bupivacaine was given at the end of surgery and the thigh tourniquet was released 2 to 3 minutes after injection. Blood samples were obtained up to 5 hours after tourniquet release and plasma bupivacaine concentrations were determined. Pharmacokinetic parameters determined were (mean +/- SD): volume of distribution (Vd beta) 206 +/- 88 L, clearance (Cl) 0.816 +/- 0.378 L/min, terminal half-life (T1/2) beta 189 +/- 84 minutes, absorption rate constant (ka) 9.92 +/- 6.79/min, estimated peak plasma concentrations (Cpmax) 0.48 +/- 0.20 micrograms/mL, and time to peak concentration (tmax) 43.4 +/- 23.1 minutes. Results indicate that injections of 100 mg bupivacaine intra-articularly after knee arthroscopy produce peak blood concentrations within the first hour after surgery, and that these will be well below concentrations associated with toxic reactions. Peak concentrations can be minimized with shorter tourniquet inflation times and with longer intervals between injection and tourniquet release.