Children's Bone & Spine Surgery

Pathologic characteristics of the torn human meniscus.

Department of Orthopaedic Surgery, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.

BACKGROUND: Acellular meniscus tissue is at a high risk for degeneration and retear. Information that would help surgeons predict, preoperatively, or intraoperatively which torn menisci had few viable cells could be useful in deciding which patients might be at increased risk for retear and failure of surgical repair. HYPOTHESIS: Patient age, length of time since injury, and tear type are predictors of the cellularity of meniscus tissue. STUDY DESIGN: Descriptive laboratory study. METHODS: Gross and histologic evaluation of torn meniscus tissue from 44 patients and 10 control menisci was performed. RESULTS: The patient factors of age, time since injury, and tear type all had significant effects on the pathologic characteristics of the torn meniscus. Patients older than 40 years had lower cellularity in the torn menisci than did patients younger than 40 years (P < .01). As time since injury increased, so did the rates of DNA fragmentation in the midsubstance of the meniscus and rates of Outerbridge II changes in the adjacent cartilage. Worse meniscal histologic scores were found in menisci with degenerative and radial tear types. CONCLUSION: Patient age had a significant effect on the cellularity of the torn meniscus, with patients older than 40 years having significantly fewer meniscus cells than did those younger than 40 years. Further studies are needed to define the relative importance of the individual histologic findings in the clinical setting of meniscus tear and repair. CLINICAL RELEVANCE: In light of their decreased cellularity, menisci from patients older than 40 years may be more vulnerable to degeneration and retear after repair than are menisci of younger patients.

PMID: 17092929 [PubMed - indexed for MEDLINE]

Correlation of interosseous membrane tears to the level of the fibular fracture.

Nielson JH, Sallis JG, Potter HG, Helfet DL, Lorich DG.

Department of Orthopaedic Surgery, Albert Einstein College of Medicine, Hospital for Special Surgery, New York, NY 10021, USA.

OBJECTIVES: To correlate interosseous membrane (IOM) tears of the ankle to the height of fibular fractures in operative ankle fractures. DESIGN: Prospective clinical trial. SETTING: University Level 1 trauma center. PATIENTS: All patients admitted with a closed operative ankle fracture were included. Of 93 patients originally evaluated, 73 patients had adequate MRI for evaluation. INTERVENTION: Open reduction and internal fixation of each ankle fracture was performed after preoperative MRI evaluation of the IOM. Transsyndesmotic screw fixation was performed when evidence of syndesmotic instability was shown by intraoperative stress testing. MAIN OUTCOME MEASUREMENTS: Radiographs were analyzed for fracture classification and prediction of ligamentous injuries about the ankle. MRI evaluated the IOM integrity, correlating it to the height of the fibular fracture. RESULTS: Of the 73 ankle fractures with adequate MRI evaluation, 30 had identifiable complete IOM tears on MRI. Ten of the 30 IOM tears did not correlate with the level of the fractured fibula. Seven cases had IOM tears proximal to the fibular fracture as detected by MRI. Five of these cases were Weber B type fractures, and two were Weber C type fracture patterns. Conversely, three cases of Weber C type fractures had IOM tears that remained distal to the level of the fibular fracture. CONCLUSIONS: The level of the fibular fracture does not correlate reliably with the integrity or extent of the interosseous membrane tears identified on MRI in operative ankle fractures. One cannot consistently estimate the integrity of the IOM and subsequent need for transsyndesmotic fixation based solely on the level of the fibular fracture. An intraoperative syndesmotic stress test is recommended to establish the presence or absence of syndesmotic instability.

PMID: 14743024 [PubMed - indexed for MEDLINE]

Radiographic measurements do not predict syndesmotic injury in ankle fractures: an MRI study.

Department of Orthopaedic Surgery, Jacobi Medical Center, New York, NY 10021, USA.

Several radiographic measurements have been described and are used to determine ligamentous injury in ankle fractures, particularly of the deltoid and syndesmosis complex. Because the accuracy of these radiographic measurements has been questioned, we sought to evaluate their accuracy using magnetic resonance imaging as an indicator for injury. Seventy patients with closed ankle fractures were entered prospectively into the study, and all had standard plain radiographic evaluations before reduction (anteroposterior, lateral, and mortise) and magnetic resonance imaging. Four radiographic measurements were made on initial ankle injury films: tibiofibular clear space on the anteroposterior view, tibiofibular overlap on the anteroposterior and mortise views, and medial clear space on the mortise view. These radiographic measurements and their association with magnetic resonance imaging findings then were analyzed. A medial clear space measurement greater than 4 mm correlated with disruption of the deltoid and the tibiofibular ligaments. We found no association between the tibiofibular clear space and overlap measurements on radiographs with syndesmotic injury on magnetic resonance imaging scans. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

PMID: 15995444 [PubMed - indexed for MEDLINE]