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.

Revision ACL reconstruction outcomes: MOON cohort

Many clinicians believe that the results of revision anterior cruciate ligament (ACL) reconstruction compare unfavorably with primary ACL reconstruction. However, few prospective studies have evaluated revision ACL reconstruction using validated patient-based metrics. This study was performed to evaluate and compare the results of revision ACL reconstruction and primary ACL reconstruction. The Multicenter Orthopaedic Outcomes Network consortium is an NIH-funded, hypothesis-driven, multicenter prospective cohort study of patients undergoing ACL reconstruction. All patients preoperatively complete a series of validated patient-oriented questionnaires. At scheduled 2-year follow-up all patients are given the same series of questionnaires to complete. The study evaluated the results of 2-year follow-up of revision ACL reconstruction performed in 2001. Parameters evaluated included Marx activity level, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores. For this study 446 subjects met inclusion criteria; 2-year follow-up was obtained on 393 (88%). The study group consisted of 55% males with median age of 22 years. There were 33 revision ACL reconstruction cases, for which follow-up was available for 29 (88%). Median baseline Marx (interquartile range) was 12 (8 to 16) and 12 (6 to 16) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.81). At 2 years, median Marx was 9 (4 to 13) and 5 (0 to 10) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.03). Median 2-year IKDC was 75.9 (revision) versus 83.9 (primary) (p=0.003). Median KOOS subscale Knee Related Quality of Life (KRQOL) at 2 years was 62.5 (revision) versus 75 (primary) (p < 0.001), subscale Sports and Recreation was 75 (revision) and 85 (primary) (p = 0.005), subscale Pain was 83.3 (revision) and 91.7 (primary) (p= 0.002). Marx activity score declined at 2-year follow-up in revision ACL reconstruction compared with primary ACL reconstruction. IKDC and KRQOL were significantly decreased in revision ACL reconstruction compared with primary ACL reconstruction at 2-year followup. Revision ACL reconstruction resulted in a significantly worse outcome as measured by these patient-based measures at 2 years.

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.

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.

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.

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)