Mapping of cartilage depth in the knee and elbow for use in osteochondral autograft procedures.

BACKGROUND: Osteochondritis dissecans (OCD) of the elbow is a problematic condition that affects a fair number of young athletes. One treatment option is the use of osteochondral autografts, which are commonly taken from donor sites on the less weightbearing surfaces of the knee. PURPOSE: To use magnetic resonance imaging (MRI) to assess the cartilage depths of sites in the knee and elbow that are commonly used as donor and recipient sites to optimize depth matching for osteochondral autograft procedures. STUDY DESIGN: Descriptive laboratory study. METHODS: All knee and elbow MRI scans acquired from 3-T machines in patients aged 16 to 25 years within a single hospital system were reviewed. Studies were excluded if there had been previous surgery on the joint or if there were significant chondral defects in the areas to be measured. All cartilage depth measurements were independently performed by 3 different physicians to the nearest 0.01 mm. At the elbow, 6 locations on the capitellum and 2 on the trochlea were chosen. At the knee, 4 locations along the anterior-lateral femoral condyle, 5 surrounding the intercondylar notch, and 1 on both the medial- and lateral-posterior femoral condyles were chosen. RESULTS: There were 111 knee MRI (74 male, 37 female) and 94 elbow MRI (85 male, 9 female) scans that met all inclusion criteria. The average cartilage depths from each investigator were then averaged to provide an overall mean depth at each location. All average cartilage depths within the knee were thicker than those in the elbow, where the averaged mean thickness of all the 8 measured sites was 1.27 mm (range, 0.78-1.63 mm). Within the knee, the thinnest areas of cartilage, and therefore closest matches, were discovered at the posterior pole of the medial femoral condyle (mean ± SD, 1.95 ± 0.46 mm) and at the distal-most anterior-lateral femoral condyle (1.85 ± 0.46 mm). The average variance between the mean cartilage depths measured by each investigator for each location was 0.12 mm in the elbow and 0.22 mm in the knee. CONCLUSION: Average cartilage depths in the knee were thicker than those in the elbow at all sites measured. The thinnest areas in the knee were the posterior aspect of the medial femoral condyle and the distal-most aspect of the anterior-lateral femoral condyle. CLINICAL RELEVANCE: This study provides the surgeon with meaningful data on average cartilage depths at common donor sites in the knee and recipient sites in the elbow.

Accuracy of 3-Tesla magnetic resonance imaging for the diagnosis of intra-articular knee injuries in children and teenagers.

BACKGROUND: Magnetic resonance imaging (MRI) is a commonly used tool for the diagnosis of intra-articular knee pathologies. Although many studies have reported the accuracy of MRI in the adult population, fewer studies have investigated these tests in younger patients. Furthermore, these studies have shown a higher variability in both the sensitivity and the specificity of MRI for these knee injuries in this age group. Advancements in MRI technology, such as the 3-Tesla (3T) MRI magnet, have shown promising results for musculoskeletal injury diagnosis in adults. This study aims to evaluate 3 T MRI for the diagnosis of intra-articular knee pathologies in a pediatric and adolescent patient population. METHODS: The records of 116 patients (119 knees) under the age of 20 years who underwent 3 T MRI studies of the knee and subsequent knee arthroscopy were reviewed retrospectively. The MRI report from the musculoskeletal radiology staff, the interpretation from the staff orthopedic surgeon, and the operative note dictations were compared, with a focus on meniscus and anterior cruciate ligament (ACL) pathologies. Seventeen orthopedic staff reads were not obtainable. Arthroscopy was used as the gold standard for diagnosis. RESULTS: The average age at MRI exam was 16.0 years and at surgery was 16.2 years. Using the musculoskeletal radiologist interpretation, the sensitivity and the specificity of 3 T MRI were 81.0% and 90.9% for medial meniscus injuries, 68.8% and 93% for lateral meniscus injuries, and 97.9% and 98.6% for ACL injuries, respectively. The orthopedic surgeon's interpretation of 3 T MRI had a sensitivity and specificity of 75.7% and 92.4% for medial meniscus injuries, 69.8% and 98.3% for lateral meniscus injuries, and 100% and 98.6% for ACL injuries, respectively. Posterior horn tears had the greatest discrepancies. CONCLUSIONS: When performed on pediatric and adolescent patients, newer 3 T MRI studies have excellent accuracy for diagnosing ACL tears. These studies also show a higher accuracy for the diagnosis of medial meniscal tears than lateral meniscal tears. LEVEL OF EVIDENCE: Diagnostic study--Level 2.

Long-term outcomes of postoperative septic arthritis after anterior cruciate ligament reconstruction.

BACKGROUND: Septic arthritis is a rare but potentially devastating complication of anterior cruciate ligament (ACL) reconstruction surgery. Several studies, including one by this group, have reported short- and medium-term outcomes, but to our knowledge there are no long-term follow-up studies. HYPOTHESIS: Postoperative septic arthritis after ACL reconstruction surgery will lead to diminished long-term outcomes compared with surgery without infectious complications, likely related to the development of arthritis. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Four of 831 consecutive patients undergoing arthroscopically guided ACL reconstruction surgeries performed by 1 surgeon were previously reported on by this group at an average follow-up of 36 months. These same patients were contacted and reevaluated. Each patient underwent a physical examination, functional testing, and subjective evaluations with the SF-36, Lysholm, International Knee Documentation Committee (IKDC), and Tegner activity scale scores. Plain film radiographs and magnetic resonance imaging (MRI) scans were analyzed by 2 musculoskeletal radiologists. RESULTS: Average follow-up time for this study was 17.9 years, and average age was 44.3 years. No other injuries or surgeries had occurred from the time of the previous study. Each patient had a decline in SF-36, Lysholm, and IKDC score, and the average Tegner score was unchanged. Average vertical hop test performance and Biodex dynamometry were both improved. The average side-to-side displacement measured via the KT-1000 arthrometer was increased. Radiographic and MRI studies revealed progression of arthritis in all patients and ACL graft rupture in 1 patient. CONCLUSION: Patients who develop septic arthritis as a complication of ACL reconstruction surgery have diminished long-term subjective, functional, and radiographic outcomes compared with historical reports of uncomplicated cases, likely related to pain from advanced arthritis. As compared with their own earlier follow-up, these patients had declines in pain-related subjective measures but remained stable or improved in both functional testing and activity-related subjective scales.