John J. Block

Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

PURPOSE To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. METHODS We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. RESULTS At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. CONCLUSIONS Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Diagnostic abilities of magnetic resonance imaging in traumatic injury to the posterior ligamentous complex: the effect of years in training

BACKGROUND CONTEXT The integrity of the posterior ligamentous complex (PLC) has been proposed to be an integral aspect in the treatment algorithm for spinal trauma. Magnetic resonance imaging (MRI) has been reported as the ideal tool to determine the integrity of the PLC. The ability to assess disruption of the PLC by reviewers of differing levels of training has not been described. In addition, the MRI sequence most suggestive of injury for each component of the PLC has not been clearly determined. PURPOSE This study was designed to determine the ability of reviewers with differing levels of training (fellowship-trained spine surgeon, fellowship-trained musculoskeletal radiologist, senior orthopedic surgery resident, and junior orthopedic surgery resident) to accurately interpret the results of MRI. The secondary purpose was to evaluate the MRI sequence that was most indicative of injury to the components of the PLC. STUDY DESIGN This is a prospective radiological study comparing reviewers of MRI to determine integrity of the PLC components using intraoperative notation as the gold standard for integrity. PATIENT SAMPLE Forty-five consecutive spinal trauma patients who underwent operative fixation after obtaining MRI. OUTCOME MEASURES No patient outcome measures were used. METHODS The sensitivity, specificity, and accuracy for each MRI reviewer in regard to MRI integrity were compared with the gold standard of intraoperative observation. In addition, the MRI sequence most suggestive of integrity of the PLC was noted by each reviewer for each component of the PLC. RESULTS Forty-five patients (29 men and 16 women) with traumatic spine injuries were enrolled in the study. The sensitivity and accuracy of the surgeon were 0.83 (0.66, 0.92) and 0.81 (0.70, 0.88), respectively. The sensitivity and accuracy of the attending spine surgeon were not statistically significantly different from the other reviewers (p value=.2317 and .2582). However, the specificity of the surgeon was statistically significantly higher than that of the other reviewers (p=.0043). In the cervical, thoracic, and lumbar spine, the reviewers reached a 93% agreement that the sagittal short-tau inversion recovery (STIR) sequences were most helpful in visualizing injury to the supraspinous ligament (SSL), interspinous ligament (ISL), ligamentum flavum (LF), and the cervical facet capsules. The reviewers attained a 95% agreement that visualization of injury to the lumbar facet capsules is most optimal in the T2 axial sequences. CONCLUSIONS The interpretation of traumatic MRI is very sensitive and accurate regardless of years of training of the observer. The attending-level spine surgeon was statistically more specific in the evaluation of injury MRIs. The fluid-weighted STIR sagittal sequences are most useful in determining injury to the SSL, ISL, LF, and cervical facets capsules. Lumbar facet capsules are best evaluated with axial T2 MRI. The evaluation of the PLC on MRI can be accurately and efficiently interpreted by physicians at multiple levels of training, thus providing a key imaging modality in determining stability and need for stabilization.

A decade in banking Ewing sarcoma: a report from the children’s oncology group

Outcomes for patients with metastatic and recurrent Ewing sarcoma remain poor and a better understanding of the biology of this malignancy is critical to the development of prognostic biomarkers and novel therapies. Therefore, the Children’s Oncology Group (COG) has created tissue banking protocols designed to collect high quality, clinically annotated, tumor specimens that can be distributed to researchers to perform basic science and correlative investigation. Data from the COG Ewing sarcoma tissue banking protocols AEWS02B1 and its successor study AEWS07B1 were reviewed in this study. Six-hundred and thirty five patients were enrolled on AEWS02B1 and 396 patients have had tissue submitted to AEWS07B1. The average age of participation was 13.2 years. About 86% were less than 19 years old and only 6% were greater than 21 years of age at diagnosis. When compared to SEER data, approximately 18% of all cases and only 8% of all patients >20 years old diagnosed with Ewing sarcoma annually in the United States have had tumor banked. The majority of participants submitted formalin fixed, paraffin embedded, primary tumor and blood samples. In total, fresh frozen tissue was submitted for only 29% of cases. Only seven metastatic tumor samples have been collected. Although the COG has been successful in collecting tumor samples from patients newly diagnosed with Ewing sarcoma, fresh frozen tumor specimens from primary and metastatic disease are critically needed, especially from young adult patients, in order to conduct high quality basic science and translational research investigation with a goal of developing better treatments.

Transarticular spread of Ewing sarcoma mimicking septic arthritis

Transarticular spread of tumor is rare; it has only been reported in the sacroiliac joint, intervertebral disk spaces, and facet joints. The anatomic and kinetic characteristics of the sacroiliac joint, as well as the changes the joint undergoes during a lifetime, make it particularly vulnerable to transarticular tumor invasion. Although extremely rare, Ewing sarcoma can extend through the sacroiliac joint and be virtually indistinguishable radiologically from septic arthritis. Furthermore, the clinical presentation of a child with Ewing sarcoma can be similar to that of a child with osteomyelitis. Laboratory values are quite nonspecific and are not always helpful in differentiating between the entities. Therefore, the possibility of sacroiliac joint transarticular Ewing sarcoma should be considered in a child presenting with hip pain, despite clinical, radiological and laboratory findings suggesting an infectious process.

Unusual stress fracture in an adolescent baseball pitcher affecting the trochlear groove of the olecranon

Stress fractures of the proximal ulna are known to occur in throwing athletes. Most cases extend to involve the olecranon, and cases limited to the trochlear groove are rare. In this report we present a 17-year-old elite baseball pitcher with a stress fracture of the trochlear groove of the proximal ulna. Diagnosis was made by demonstration of characteristic signal changes on MRI of the elbow. The fracture occurred at the cortical notch, also known as the pseudodefect of the trochlear groove. This case suggests that the cortical notch serves as an area of weakness predisposing pitchers to development of a stress fracture.

Operative Fixation of Chondral Loose Bodies in Osteochondritis Dissecans in the Knee A Report of 5 Cases

Background: Osteochondritis dissecans (OCD) can progress to loose body formation, with or without subchondral bone attachment to the lesion. The efficacy of internal fixation of chondral loose bodies has not been determined. Hypothesis: Operative fixation of cartilaginous loose bodies would result in (1) healed OCD at second-look arthroscopy, (2) restored cartilage appearance on magnetic resonance imaging (MRI), and (3) nearly normal knee function, as determined by patient-reported outcome scores. Study Design: Retrospective case series; Level of evidence, 4. Methods: Five patients who underwent cartilaginous loose body fixation were identified. Lesions were located on the lateral trochlea (n = 2) and medial femoral condyle (n = 3) (mean size, 2.5 cm2). Loose bodies were reattached with compression screws through mini-arthrotomy or arthroscopy. Patients were nonweightbearing for 12 weeks postoperatively. After 12 weeks, screws were removed arthroscopically, and OCD stability was evaluated. Three patients underwent MRI to determine articular cartilage status. Images were evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) score. Patients were interviewed and completed the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Results: Four patients had stable lesions at 12 weeks after surgery. One patient had slight motion to one-third of the lesion and stability to the remaining two-thirds. Three patients underwent an MRI. The mean time from surgery to MRI was 3.1 years. Mean MOCART score was 72.0 ± 10.4. One patient required repeat arthroscopy 1 year after initial fixation for debridement and arthroscopic drilling of an incompletely healed area of the lesion. Four patients completed the KOOS questionnaire. The mean time to KOOS completion was 4.6 years. Mean KOOS subscales for knee pain (91.0 ± 8.9), knee symptoms (83.0 ± 7.9), and function in activities of daily living (91.9 ± 10.6) were similar to published age-matched controls; however, scores for sports and recreation function (70.0 ± 17.8) and knee-related quality of life (67.2 ± 12.9) were lower. Conclusion: Operative fixation of chondral loose bodies, without macroscopically visible subchondral bone attachment, resulted in lesion stability at second-look arthroscopy. At final follow-up, patients had no substantial pain and normal function in activities of daily life compared with controls; however, knee-related quality of life and sport and recreation function were reduced, and 1 patient required reoperation for an unhealed portion of the lesion.

Minute amounts of intraarticular gas mimicking torn discoid lateral menisci

Presented are two cases of minute amounts of vacuum phenomena within the central portion of the lateral compartments of two knee joints, mimicking torn discoid lateral menisci. In each case, only the gradient echo images were able to correctly characterize the minute quantities of intraarticular gas by demonstrating “blooming” magnetic susceptibility artifact. The signal characteristics of the intraarticular gas were identical to those of fibrocartilage on all of the remaining routine, fast spin echo, “sports protocol” magnetic resonance imaging sequences. J. Magn. Reson. Imaging 2010;31:698–702.

Prevalence and Clinical Manifestations of the Anconeus Epitrochlearis and Cubital Tunnel Syndrome

Background: The true prevalence of the anconeus epitrochlearis (AE) and the natural history of cubital tunnel syndrome associated with this anomalous muscle are unknown. The purpose of this study was to evaluate the prevalence of AE and to characterize the preoperative and postoperative features of cubital tunnel syndrome caused by compression from an AE. Methods: All elbow magnetic resonance imaging (MRI) scans and all patients undergoing cubital tunnel surgery during a 20-year period were identified and retrospectively reviewed for the presence of an AE. All patients with an AE identified intra-operatively were matched to patients with no AE identified at surgery based on age, sex, concomitant procedures, and year of surgery. Preoperative and postoperative physical exam findings, electrodiagnostic study results, time to improvement, and reoperations were compared between the groups. Results: A total of 199 patients had an elbow MRI, and 27 (13.6%) patients were noted to have an AE present. Average time to improvement after surgical release was 23.0 days for patients with an AE and 33.2 days for patients with no AE. Twenty-seven patients with an AE noted improvement at the first postoperative visit (68%) compared to 15 patients without an AE (33%). No patients with an AE underwent reoperation for recurrent symptoms (0%) compared with four patients (10%) without an AE. Conclusions: The prevalence of AE in our study is 13.6%. These patients experience quicker and more reliable symptom improvement after surgical release than those without the anomalous muscle.

Symptomatic Accessory Medial Meniscus Associated With Popliteal Pterygium Syndrome.

Background: Anomalies of the meniscus are uncommon. These anomalous formations have been predominately described in the lateral compartment of the knee. Congenital abnormalities of the medial meniscus are rare. Methods: Chart and radiographic review of a single patient with a symptomatic congenital abnormality of the medial meniscus. Results: The patient was a 5-year-old boy with popliteal pterygium who developed painful snapping in the medial knee after anterior hemiepiphyseodesis to improve his knee extension. The patient had achieved full-knee extension from a preoperative 45-degree flexion contracture. The newly developed snapping was attributed to the hemiepiphyseodesis implants. After implant removal, the snapping persisted and was localized at the medial joint line. Through an arthrotomy, a medial meniscus abnormality was identified and excised with resolution of symptoms. Conclusions: This report describes a symptomatic congenital abnormality of the medial meniscus in a child with popliteal pterygium. The patient was treated with excision of the anomalous structure with complete resolution of the symptoms. This is the first report of an intra-articular knee anomaly associated with popliteal pterygium syndrome.

Inadvertent intraosseous gadolinium injection during pediatric shoulder MR arthrography

A variety of problems can arise while performing MR arthrography of the shoulder. These have been well documented in the literature and range from improper patient selection to errors in technique or in the choice of imaging sequences. We present a rare case of inadvertent, painless intraosseous injection of dilute gadolinium into the proximal humeral epiphysis of a 13-year-old male athlete. The clinical relevance is discussed and technical recommendations are offered.