Development of the meniscus of the knee joint in human fetuses.

Discoid meniscus of the knee joint occurs at a higher incidence in the lateral than in the medial menisci. Although its developmental origin has been suggested, it remains unclear. To verify the developmental etiology, we examined the meniscus of the knee joint in 41 human fetuses (from 14 to 30 weeks of gestation) and 14 adults (from 56 to 91 years of age) comparatively. The articular surfaces of the tibia and meniscus of the left knees in 40 fetuses and 14 adults were photographed and each area was measured by Scion Image (Scion; http://www.scioncorp.com). Morphometric analyses revealed that the proportion of the area of meniscus to that of the plateau was continuously higher in the lateral side than in the medial side. The right knee joints of seven fetuses were histologically observed, and the layered structure of fibers developed earlier in the lateral meniscus than in the medial in fetuses. The observed differential development of lateral and medial sides of the meniscus may be involved in the etiology of discoid meniscus.

Arthroscopic assessment for intra-articular disorders in residual ankle disability after sprain.

BACKGROUND: After ankle sprain, there can be many causes of disability, the origins of which cannot be determined using standard diagnostic tools. HYPOTHESIS: Ankle arthroscopy is a useful tool in identifying intra-articular disorders of the talocrural joint in cases of residual ankle disability after sprain. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: The authors gathered the independent diagnostic results of physical examination, standard mortise and lateral radiography, stress radiography of the talocrural joint, and magnetic resonance imaging for 72 patients with residual ankle disability lasting more than 2 months after injury (mean, 7 months after injury). They performed arthroscopic procedures and compared the double-blind results. RESULTS: In all cases, the arthroscopic results matched those of other means of diagnosis. In 14 cases, the arthroscopic approach exceeded the capabilities of the other methods. Including duplications, 39 patients (54.2%) had anterior talofibular ligament injuries, 17 patients (23.6%) had distal tibiofibular ligament injuries, 29 patients (40.3%) had osteochondral lesions, 13 patients (18%) had symptomatic os subfibulare, 3 patients (4.2%) had anterior impingement exostosis, and 3 patients (4.2%) had impingement due to abnormally fibrous bands. There were only 2 cases in which the cause of symptoms could not be detected by ankle arthroscopy, compared with 16 cases in which the cause of disability could not be detected using standard methods. In 3 cases (17.6%) of distal tibiofibular ligament injuries, 8 cases (27.6%) of osteochondral lesions, and all 3 cases (100%) of impingement of an abnormal fibrous band, ankle arthroscopy was the only method capable of diagnosing the cause of residual ankle pain after a sprain. CONCLUSION: The present results suggest that arthroscopy can be used to diagnose the cause of residual pain after an ankle sprain in most cases that are otherwise undiagnosable by clinical examination and imaging study.

Diagnosis and treatment of combined intra-articular disorders in acute distal fibular fractures.

BACKGROUND: Some patients have residual ankle pain and disability after the treatment of an ankle fracture, despite the fracture site being well aligned. We identified intra-articular disorders in distal fibular fractures and sought to clarify the results of their operative treatment. METHODS: This is a prospective, randomized study. Seventy-two patients with Weber type B distal fibular fractures were randomly treated with arthroscopy-assisted open reduction and internal fixation (AORIF) or with open reduction and internal fixation without arthroscopy (ORIF). In the AORIF group, the patients were followed for a mean duration of 3 years 4 months (range, 2 years 4 months-4 years 5 months). There were 27 male patients and 14 female patients. The mean age of the patients at the time of surgery was 36 years (range, 20-64 years). In the ORIF group, the patients were followed for a mean duration of 3 years 5 months (range, 2 years 7 months-4 years 5 months). There were 21 male patients and 10 female patients. The mean age of the patients at the time of surgery was 38 years (range, 20-58 years). We described intra-articular disorders in the AORIF group using ankle arthroscopy and compared their operative results with those of the ORIF group. RESULTS: Including duplication, the arthroscopic findings showed 30 cases with osteochondral lesions of the talar dome (73.2%) and 33 cases with tibiofibular syndesmosis disruptions (80.5%). Six cases (14.6%) had no combined disorders. The mean AOFAS score was 91.0 +/- 3.5 (range, 85-100) in the AORIF group, in contrast to 87.6 +/- 5.5 (range, 77-97) in the ORIF group (p = 0.0106). CONCLUSION: In the treatment of distal fibular fractures, precisely diagnosing and treating the combined intra-articular disorders is important for gaining satisfactory clinical results.