Bilateral discoid medial menisci.

SUMMARY: This article adds 2 more cases of bilateral discoid medial menisci to the previously reported 9 cases. The radiographs of the first case revealed bilateral cupping of the medial tibial plateaus and a small lytic lesion of the left distal medial femoral metaphysis. Beside the posteriorly unstable incomplete type discoid medial meniscus, the left knee had several associated arthroscopic findings: depression of the medial tibial plateau with exposed subchondral bone, anomalous insertion of the anterior horn of the discoid meniscus to the anterior cruciate ligament, a pathological medial plica, and longitudinal deep fissures in the trochlea. The second case was a complete type with peripheral horizontal cleavage tears. Following arthroscopic surgery, magnetic resonance imaging (MRI) scans of the contralateral knees were obtained in both cases to search for bilaterality. MRI revealed discoid medial menisci in the unoperated knees as well. The short-term results of arthroscopic meniscectomy may not be as satisfactory as those reported for normal menisci.

The distal fascicle of the anterior inferior tibio-fibular ligament as a cause of anterolateral ankle impingement: results of arthroscopic resection.

We arthroscopically resected the impinged distal fascicle of the anterior inferior tibiofibular ligament (AIT-FL) in 21 patients (mean age 31 (11-68) years, 14 women) with chronic ankle pain after an ankle sprain. Clinical tests revealed moderate laxity in 2 and severe laxity in another 2, the remaining 17 ankles showing only mild laxity. During arthroscopy, an impinging distal fascicle of the AITFL was found in all cases. Following anterolateral synovectomy, the fascicle was excised. At the follow-up after mean 3 (2-4) years, good-to-excellent results were obtained in 17 patients. 19 patients were satisfied with the procedure and 17 patients returned to their previous level of activity. 2 patients who had mild laxity were graded as poor because of neuromas of the terminal branches of the superficial peroneal nerve. These patients became asymptomatic after an injection of steroids.

Dislocating anterior horn of the medial meniscus.

Dislocating anterior horn of the medial meniscus was found in 15 knees of 13 patients during arthroscopic examinations done between 1992 and 1995. All of them were available for follow-up evaluation (4 by telephone). There were 11 men and 2 women (average age, 28 years; range, 17 to 49 years). Nine knees had a history of trauma. Only 1 knee had had trauma in two bilateral cases. Duration of symptoms was an average of 3.3 years (range, 3 months to 10 years). The knees were stable clinically. Arthroscopy revealed associated lesions in 13 knees; hypertrophic medial plicae, meniscal, chondral and anterior cruciate ligament (ACL) lesions predominated. Three knees had unusually hypertrophic ligamentum mucosum. Eleven of 13 knees had more than one associated lesions. Only 2 knees (2 patients) had isolated dislocating anterior horn of the medial meniscus. Only the associated lesions were treated (except for ACL lesions) and dislocating anterior horns of the medial menisci were left alone. Follow-up averaged 21 months (7 to 40 months). At follow-up, 11 knees were graded as excellent, 3 as good, and 1 as fair according to the Lysholm scale. Eight knees had minor symptoms and 6 were asymptomatic; no improvement was noted in 1 knee. Overall, 12 patients (14 knees) were satisfied with their treatment. Dislocating anterior horn of the medial meniscus is a normal anatomic variant with little or no clinical significance. When seen during arthroscopy, a significant lesion should be looked for. It is an incidental finding and should be left alone.

Bone bruises detected by magnetic resonance imaging following lateral ankle sprains.

Although bone bruises have been well described in the knee joint, little is known about their presence in the ankle joint. The present study attempted to document the association of bone bruises with lateral ankle sprains. Magnetic resonance (MR) images were obtained from 60 consecutive patients with lateral ankle sprains between April 1994 and June 1995. There were 29 men and 31 women, aged on average 25 years (range 12-68 years). All of the patients presented within 3 weeks of the sprain. MRI examinations were done within 3 weeks of the injury in 15, after 3-6 weeks in 21, and after 6-8 weeks in 24 cases. There were 28 first-time sprains, while 32 patients had suffered one or more sprains before the most recent one. Plain radiographs showed no evidence of osseous abnormality. Following the conventional MRI examination, magnetic resonance arthrography (MRA) was done by injecting 2 mM of gadolinium diethylene triamine penta-acetic acid (DTPA) into the joint under fluoroscopic control, and the same images were obtained again to search for ligamentous lesions. A total of 11 bone bruises were detected in 10 ankles. In this group of patients, there were 5 men and 5 women aged on average 27 years (range 12-50 years). Four MRI examinations were done within 3 weeks, while six were done 3-6 weeks after the injury. One ankle which had suffered one previous sprain and complete ruptures of anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) had two lesions (talus and navicula). In another recurrent case with complete ATFL and CFL ruptures, the lesion was found in the calcaneus. The remaining eight lesions were in the talus in eight ankles. The ligamentous lesions in these ankles included three complete ATFL and CFL ruptures, and four isolated ATFL ruptures; in one ankle there were no ligamentous lesions. The location of talar bruises was medial in six and lateral in three ankles. The incidence of bone bruises associated with isolated ATFL lesions was 16% (4/25). With combined ATFL and CFL lesions the incidence was 50% (5/10). The incidence of ankles with bone bruises and first-time and recurrent sprains was 7% (2/28) and 25% (8/32), respectively. The occurrence of bone bruises should be kept in mind following ankle sprains. Their clinical significance in the long term remains to be determined.

Diagnostic value of MR arthrography in detection of intrinsic carpal ligament lesions: use of cine-MR arthrography as a new approach.

Twenty-five patients with chronic wrist pain and a preliminary diagnosis of carpal instability were examined with conventional MR imaging and MR arthrography with single compartment intra-articular injection. A new cine-MR arthrography technique, with image acquisition at every 5 s during intra-articular injection, was performed in 17 subjects. The purpose of this study was to determine the diagnostic value of MR arthrography in ligamentous lesions of the wrist and to assess the value of cine-MR arthrography in comparison with arthroscopy and/or surgery. Magnetic resonance arthrography, a semi-invasive technique, increased the diagnostic accuracy of intrinsic carpal ligament injuries. Cine-MR arthrography can be considered as a promising technique especially for the evaluation of lunatotriquetral and scapholunate ligament injuries of the wrist.

Traumatic prepatellar neuroma: an unusual cause of anterior knee pain.

Although the patellar (infrapatellar) branch of the saphenous nerve is vulnerable to direct trauma, traumatic prepatellar neuroma has rarely been reported in the literature. It should be considered in the differential diagnosis of disorders causing anterior knee pain. Point tenderness, a palpable fusiform nodule and a positive Tinel's sign are the diagnostic features. Simple excision is curative.

Intraarticular fibroma of the tendon sheath of the knee.

Fibroma of the tendon sheath is an uncommon soft-tissue tumor. Intraarticular localization has not been previously reported. The patient presented with unexplained recurrent swelling of the knee not associated with recent trauma. The soft-tissue tumor was identified by magnetic resonance imaging. Arthroscopy confirmed the diagnosis. Arthrotomy was performed because of the large size of the lesion.

Kinematic and dynamic axial computerized tomography of the normal patellofemoral joint.

Fourteen normal volunteers with no history suggesting previous or current knee pathology underwent axial computed tomographic examination of the patellofemoral joint. There were 11 men and 3 women, whose ages ranged from 10 to 46 years (average 25 years). Axial images were obtained at 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, and 60 degrees flexion both with and without contraction of the thigh muscles. Thus, 12 images were obtained for each individual. The CT scanner was focused at the midpatellar level prior to each image. Three measurements were made on 24 knees for each individual: congruence angle (CA), patellar tilt angle (PTA), and sulcus angle (SA). PTA increased slightly from 0 degrees to 20 degrees, and decreased slightly with more flexion (not significant, NS). The lower limit of PTA was usually 9 degrees-10 degrees; it was not lower than 7 degrees in any knee position. Muscle contraction increased PTA slightly at each degree of flexion (NS). Mean CA was +18.3 degrees (SD 20.8 degrees) at 0 degrees, which means that normal individuals may have CAs as high as +39 degrees at full extension. There was a gradual decrease in CAs with knee flexion. The mean values became negative between 20 degrees and 60 degrees flexion. Contraction of the thigh muscles caused lateralisation of the patella except at 30 degrees and 40 degrees flexion. This lateral pull was statistically significant at full extension (P < 0.01) and at 10 degrees flexion (P < 0.05). The SA decreased gradually as the flexion of the knee increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinematic and dynamic axial computed tomography of the patello-femoral joint in patients with anterior knee pain.

Thirty-eight knees of 26 patients with anterior knee pain (12 bilateral) were included in the study. There were 22 women and 4 men, and their average age was 29 years. Axial computed tomography (CT) examination of both knees were done at 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees and 60 degrees of flexion with and without muscle contraction. Images were always taken at the mid-patellar level. Patellar tilt angle (PTA), congruence angle (CA) and sulcus angle (SA) were measured at each knee position. Normal values were also obtained from 14 healthy volunteers (28 knees). Thus, the types of patello-femoral incongruence were determined at each knee position: 1, tilt + lateralisation (TL: 12 knees); 2, lateralisation (L: 4 knees); 3, medialisation (M: 5 knees); 4, lateral to medial instability (LM: 1 knee); 5, tilt (T: 1 knee). Fifteen knees were classified as normal. When the groups were analysed separately, in the TL group the T or L component would have been missed in nine cases if the images were taken only at 30 degrees or only in the first 30 degrees of flexion. In the L group two patellae were reduced at 30 degrees. In three knees in the M group, medialisation began at 10 degrees, 20 degrees and 30 degrees. One patella was reduced at 40 degrees. In the LM case, the patella was lateralised at 0 degrees, 10 degrees, 20 degrees and medialised at 30 degrees and 40 degrees. In the T case, the patella was tilted only at 20 degrees, 40 degrees and 60 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)