Antti O. T. Mustonen

Acute knee trauma: analysis of multidetector computed tomography findings and comparison with conventional radiography.

Purpose: To evaluate the multidetector computed tomography (MDCT) findings of acute knee trauma and to compare radiography with MDCT in patients referred to a level 1 trauma center. Material and Methods: During a 5-year period, a total of 415 MDCT examinations were performed on 409 patients with acute knee trauma to reveal complex fracture anatomy or rule out a fracture. MDCT and primary radiographs were re-evaluated with respect to fracture location and trauma mechanism. Tibial plateau fractures were further analyzed depending on anatomical location: anterior-medial, anterior-lateral, posterior-lateral, and posterior-medial regions. Maximal depression of the tibial articular surface was measured. Findings on the primary knee radiographs were compared with MDCT findings. Results: Of the 409 patients, 356 (87%) had a knee fracture. A total of 451 fractures were found in all anatomic regions: distal femur (n = 49), proximal tibia (n = 307), patella (n = 23), and proximal fibula (n = 72). Primary radiographs were available in 316 (76%) cases. Of these, 225 (71%) had MDCT in order to reveal the fracture anatomy better, and 91 (29%) had a subsequent MDCT after negative plain radiographs. Overall sensitivity of radiography was 83%, while negative predictive value was 49%. On radiography, tibial plateau articular depression was underestimated in all regions except when the fracture consisted of the whole half of the anterior or posterior plateau. The three main injury mechanisms were traffic accident, a simple fall, and sport. In 49 cases (15%), primary radiographs were suboptimal due to positioning. Conclusion: In severely injured patients, diagnostically sufficient radiographs are difficult to obtain, and therefore a negative radiograph is not reliable in ruling out a fracture. In these patients, MDCT is a fast and accurate examination and is also recommended in patients with tibial plateau fractures or complex knee injuries in order to evaluate the fracture adequately.

MRI of Acute Meniscal Injury Associated with Tibial Plateau Fractures: Prevalence, Type, and Location

OBJECTIVE The purpose of this study was to evaluate the prevalence, type, and location of meniscal injuries, particularly to assess the prevalence of unstable meniscal tears in acute knee trauma with tibial plateau fractures. MATERIALS AND METHODS A total of 78 menisci were evaluated in 39 patients who had undergone knee MDCT and MRI. Meniscal tears were classified as horizontal, vertical (subdivided into longitudinal and radial), flap, bucket-handle, or complex. The presence of meniscal contusion was documented. The anterior horn, body, and posterior horn were assessed separately for both menisci. Knee arthroscopy was performed on 28 patients. RESULTS Of the 39 patients in the study, 24 had detectable abnormal menisci, for a total of 33 abnormal menisci (42%). Among the 33 meniscal abnormalities were 11 longitudinal tears (33%), 17 contusions (52%), four flap tears (12%), six horizontal tears (18%), and six radial tears (18%). Among the 16 patients with meniscal tears (41% of the 39), 14 patients had an unstable tear. No significant correlation was found between degree of articular depression and site or morphologic features of the meniscal injury. Correspondingly, no statistical correlation was evident between normal menisci and degree of articular depression, nor was a significant correlation found between differing fracture groups and meniscal findings. CONCLUSION A high percentage of patients (36%) with a tibial plateau fracture had an unstable meniscal tear. If a meniscal tear is detected preoperatively, meniscal surgery can be combined with fracture fixation, and reoperation can be avoided. A large number of meniscal contusions were found. Awareness of this abnormality can help radiologists increase specificity by avoiding false-positive findings of meniscal tear.

Factors predicting the development of early osteoarthritis following lateral tibial plateau fractures: mid-term clinical and radiographic outcomes of 73 operatively treated patients.

Background and Aims: The indications for operative treatment of lateral tibial plateau fractures are still controversial. The objective of this study was to determine whether residual articular surface depression and valgus malalignment of plated lateral tibial plateau fractures at medium-term follow-up affect the clinical and radiographic outcomes. Material and Methods: A chart review of patients with operatively treated (AO type B3.1) tibial plateau fractures that were admitted to our level I trauma center between 2002 and 2008 was performed. Out of 123 patients, 73 were available to participate in a clinical and radiographic follow-up examination. The mean follow-up time was 54 months. Patients were clinically assessed and completed the Lysholm knee score and Western Ontario and McMaster Universities Osteoarthritis Index. Maximal articular surface depression, radiological mechanical axis, and degree of posttraumatic osteoarthritis were evaluated from standing radiographs. Results: Patients with valgus malalignment of 5° or greater at follow-up developed more advanced osteoarthritis (Kellgren–Lawrence grade 3–4) than patients with a normal mechanical axis (p = 0.006). Similarly, patients with articular depression greater than 2 mm at follow-up also developed more advanced osteoarthritis compared to patients with a depression of 2 mm or less (p = 0.001). The degree of valgus malalignment or articular depression had no effect on the Western Ontario and McMaster Universities Osteoarthritis Index or Lysholm scores. Conclusions: The postoperative articular congruity and normal mechanical axis of the lower leg after plate fixation in lateral tibial plateau fractures seem to have a role in prevention of posttraumatic osteoarthritis but does not appear to predict clinical outcome at medium-term follow-up. The role of initial dislocation and associated cartilage damage in the development of osteoarthritis following these fractures is still unknown.

Radicular lower extremity pain as the first symptom of primary hyperparathyroidism

Clinical symptoms of hyperparathyroidism are generally nausea, vomiting, fatigue, constipation, and hypotonicity of the muscles and ligaments; bone pain and tenderness are also seen but are more common in secondary hyperparathyroidism. We report a histologically confirmed case of a 28-year-old man whose sole symptom of primary hyperparathyroidism was lower extremity radicular pain due to a vertebral brown tumor. Magnetic resonance imaging demonstrated brown tumor to be hyperintense on T2-weighted and slightly hypointense on T1-weighted sequences; it showed intense contrast enhancement with gadolinium. Because brown tumors usually contain hemosiderin a short T2 should have been expected, but this was not seen in our case. Healing resulted in decreasing contrast enhancement on T1-weighted sequences and increasingly short T2. To our knowledge, this is the first report of a lumbar vertebral brown tumor associated with primary hyperparathyroidism.

Multidetector Computed Tomography in Acute Joint Fractures

Conventional radiography plays an essential diagnostic role in the primary evaluation of acute joint trauma. In complex fractures, however, computed tomography (CT) is an imaging modality often used second to radiography. As a result of technical breakthroughs in the field, multidetector CT (MDCT) allows faster imaging and better temporal, spatial, and contrast resolution compared with conventional single-slice spiral CT. MDCT with multiplanar reformation is helpful in disclosing fracture patterns, particularly in complex joint fractures, where they reveal occult fractures and show the exact number of fracture components and their degree of displacement.

Multidetector computed tomography in acute knee injuries: assessment of cruciate ligaments with magnetic resonance imaging correlation.

Purpose: To evaluate whether non-contrast multidetector computed tomography (MDCT) for suspected acute knee fractures can also be used to evaluate cruciate ligament pathology. Material and Methods: A total of 42 patients (17–65 years) underwent four-section MDCT. The images were independently evaluated at clinical workstations by four radiologists. They assessed the integrity (normal or torn) and the best slice direction (axial, sagittal, or coronal) for visualization of the cruciate ligaments. Magnetic resonance imaging (MRI), performed within 4 weeks (mean 6 days) in relation to MDCT, was considered the gold standard. Results: Ligament integrity at MDCT: the mean interobserver proportion of agreement for a normal anterior cruciate ligament (ACL) was 0.73, for a torn ACL 0.41, for a normal posterior cruciate ligament (PCL) 0.96, and for a torn PCL 0.54. Interobserver variation for ACL was significant (P = 0.0136–0.0260), but insignificant for PCL (P = 0.3389–0.7212). Intra-observer variation was insignificant. Visualization was best in the axial and sagittal direction for ACL and PCL, respectively. At MRI, 29 normal, one partially, and 12 completely torn ACLs, and 37 normal, four partially and one completely torn PCL were found. Conclusion: MDCT can detect an intact ACL and PCL with good specificity, accuracy, and negative predictive value. The assessment of torn ligaments is unreliable.

MRI of menisci repaired with bioabsorbable arrows

ObjectiveTo analyze with conventional magnetic resonance imaging (MRI) the signal appearance of menisci repaired with bioabsorbable arrows.Design and patientsForty-four patients with 47 meniscal tears treated with bioabsorbable arrows underwent follow-up conventional MRI examination. The time interval between the surgery and MRI varied from 5 to 67 months (mean 26 months). Twenty-six patients also had concurrent repair of torn anterior cruciate ligament. The following grades were used to classify meniscal signal intensity: (a) G0; low signal intensity on all sequences and regular configuration in every plane, (b) G1; increased signal intensity within the meniscus, not extending to the meniscal surface, (c) G2; increased signal intensity linear in shape, which may or may not communicate with the capsular margin of the meniscus, without extending to the meniscal surface, and (d) G3; increased signal intensity extending to the meniscal surface.ResultsThirteen menisci (27.5%) had normal signal intensity, 13 menisci (27.5%) Grade 1 signal intensity, 9 menisci (19%) Grade 2 signal intensity and 12 menisci (26%) Grade 3 signal intensity. The time difference between operation and MRI was statistically significant between the G0 (36 months) and G3 groups (14 months; P=0.0288). There was no statistical significance in different grades between medial and lateral meniscus or between patients with operated or intact ACL. On physical examination sixteen patients reported slight symptoms, seen evenly in each group.ConclusionNo difference was seen in different grades between patients with operated or intact ACL. The highest incidence of menisci with a Grade 3 signal was seen in patients where surgery was within the last 18 months.

Segond fracture combined with tibial plateau fracture.

OBJECTIVE The objective of our study was to examine the coexistence of Segond fracture in tibial plateau fractures and to assess the prevalence of anterior cruciate ligament (ACL) rupture and meniscal tear when those fractures coexist. MATERIALS AND METHODS This retrospective study was conducted at a level 1 trauma center. A total of 1203 emergency department knee trauma MDCT examinations were evaluated. Surgical findings served as the reference standard for intraarticular injuries. RESULTS A total of 33 patients with a Segond fracture were found. Of these patients, 10 had isolated Segond fractures (surgery, n = 7) and 23 patients (surgery, n = 20) had a Segond fracture associated with a tibial plateau fracture. Patients with both fractures had significantly fewer anterior cruciate ligament (ACL) ruptures (20% vs 71%, p = 0.023) and more avulsion fractures of the ACL (50% vs 0%, p = 0.026) than patients with isolated Segond fractures. For meniscal injuries, the corresponding numbers were 25% and 57% (p = 0.175), respectively. In approximately one of every 32 tibial plateau fractures, a Segond fracture also coexists. CONCLUSION Patients with a Segond fracture combined with a tibial plateau fracture have a high risk of avulsion fracture of the ACL.

Postoperative MDCT of tibial plateau fractures.

OBJECTIVE The purposes of this retrospective study were to elaborate our experience in postoperative MDCT of tibial plateau fractures, to establish the frequency of these fractures and the indications for MDCT, and to assess the common findings and their clinical importance. MATERIALS AND METHODS A total of 782 knee injuries were imaged with MDCT at a level 1 trauma center over 86 months. A total of 592 knees had a tibial plateau fracture; 381 of these fractures were managed surgically, and postoperative MDCT was performed on 36 of these knees (9%). At postoperative image analysis, an orthopedic surgeon evaluated reduction as good or suboptimal using the first postoperative radiographs. Fracture healing was determined as complete ossification, partial ossification, or nonunion on MDCT images acquired later in follow-up. The MDCT findings were compared with the radiographic findings to assess the usefulness and clinical importance of MDCT. RESULTS The main indications for MDCT were assessment and follow-up of the joint articular surface and evaluation of fracture healing. Orthopedic hardware caused no diagnostic problems at MDCT. Postoperative MDCT revealed additional clinically important information on 29 patients (81%), and 14 patients (39%) underwent reoperation. CONCLUSION Postoperative MDCT of tibial plateau fractures is performed infrequently, even in a large trauma center. When it is performed, however, because of suspicion of increasing articular step-off or fracture nonunion, postoperative MDCT reveals clinically significant information in most cases.

Treatment of compound tibial fracture with free osteomuscular latissimus dorsi scapula flap.

BACKGROUND Compound tibial fractures with extensive comminution and soft tissue defects are limb-threatening reconstructive challenges. The purpose of this study was to assess the long-term outcomes and the reliability of the latissimus dorsi scapula flap for this indication. METHODS The hospital records of 26 compound tibial fracture patients treated with the latissimus dorsi scapula flap were reviewed. An overall assessment was performed in several steps based on a preinformation and two function-related questionnaires together with radiographs, clinical overviews, and functional tests. RESULTS In 85% of the cases, the fractures had resulted from high-energy trauma and had extensive zone of injury. The mean follow-up time was 6.2 years. Nine patients required reconstruction because of prolonged sequelae after infection, nonunion, or tissue deficiency. One flap loss occurred leading to amputation. Six patients required an additional operation to enhance bony union. Full weight-bearing was allowed in 3 months and the mean time to bony union was 10 months. Overall, 90% returned to their pretrauma occupation. Overall 11 patients were lost to follow-up. A total of 14 patients answered the questionnaires whereas 12 outpatients attended the clinical assessment. The main finding after evaluating the results of the functional tests and reviewing the questionnaires was the limitation in ankle movement while the donor site performed well. CONCLUSION This study confirms that osteomuscular latissimus dorsi scapula flap reconstruction is a suitable alternative for compound and comminuted tibia fractures especially in the case of extensive soft tissue injury with bony loss or significant comminution and with high probability of amputation.