Faculty Bibliography

OBJECTIVE: The purpose of this study was to assess the performance of a near-isotropic 3D turbo spin-echo sequence in comparison with a standard 2D protocol and with arthroscopy in direct 1.5-T MR arthrography of the shoulder. SUBJECTS AND METHODS: Dilute gadolinium was injected into three cadaver shoulders, and 3D turbo spin-echo and 2D sequences were evaluated with respect to the signal-to-noise and contrast-to-noise ratios of key tissues. In a prospective study, the 3D intermediate-weighted fat-suppressed sequence (reformatted in three planes) was added to shoulder MR arthrography of 43 consecutively registered patients, 13 of whom later underwent arthroscopy. Two radiologists independently graded the 3D and 2D images in separate sessions to visualize normal anatomic features and to detect pathologic changes in the labrum, cartilage, cuff, and glenohumeral ligaments, assigning confidence levels to their readings. One reader repeated the readings of images of 10 patients. Reports of subsequent arthroscopy were available for 13 patients. RESULTS: The sequences performed comparably with respect to signal-to-noise and contrast-to-noise ratios in the cadavers. The 3D images suffered from mildly increased blurring, but the readers were significantly more confident in assessing the proximal biceps tendon and curved portions of the labrum and in their findings of partial tears of the articular side of the supraspinatus tendon and posterior labral tears on the 3D images. A larger number of partial-thickness cartilage defects were found on 2D images. CONCLUSION: The 3D turbo spin-echo sequence is a promising technique that can be used in shoulder arthrography with image quality and results comparable to those of traditional 2D techniques. Use of the 3D technique may result in greater anatomic detail in evaluating small obliquely oriented structures, including the curved portions of the labrum and the intraarticular portion of the biceps tendon.

Purpose: To review the potential etiologies of neurogenic pelvic pain and to describe diagnostic features with a particular emphasis on lesions detected by cross sectional imaging. Materials and Methods: A retrospective review of cases presenting with pelvic neurogenic pain during the past 3 years was performed at our institution using our hospital data search engine. All patients had undergone cross sectional imaging, including dedicated pelvic MR neurography. The study group was classified according to location of involvement including: 1) obturator neuropathy, 2) femoral neuropathy, 3) pudendal neuropathy, 4) superior gluteal neuropathy and 5) piriformis syndrome. The presence of associated denervation muscle changes was recorded. Cases were further characterized by etiology into: 1) Space occupying lesions, 2) Iatrogenic and 3) Post traumatic. A review of the literature was performed and the findings are presented in a pictorial fashion with case by case illustration. Results: Twenty-four cases were collected. Of these, 6 patients had symptoms of pelvic neurogenic pain with no apparent imaging findings. Eight patients had radiological evidence of possible obturator nerve compression, 1 patient had findings suggestive of obturator nerve injury, 2 patients had radiological evidence of piriformis syndrome, and 2 patients each had radiological evidence of pudendal and femoral nerve involvement. Two patients had multiple sites of involvement. A wide variety of space occupying lesions were found including neurogenic lesions, perineural cysts, ganglion cysts, malignant tumors, and fluid distended bursae. Impingement related to post surgical changes following hip arthroplasty and related to prior pelvic fracture was also identfied. Denervation muscle changes were noted in several patients, including in patients with no radiologically detectable lesion. Conclusion: There are multiple potential etiologies for neurogenic pelvic pain. Clinical localization of symptoms as well as knowledge of the pelvic neural anatomy is of critical importance in the search for an underlying etiology. Muscle denervation changes are a very useful secondary sign of pelvic neuropathy particularly in the absence of a detectable compressive etiology on MR imaging

Improvement in both hardware and software has opened up new opportunities in magnetic resonance (MR) imaging of the shoulder. MR imaging at 3-T has become a reality, with the prospect of 7-T imaging on the horizon. The art of MR arthrography continues to improve, aided by the use of novel imaging positions. New techniques for three-dimensional imaging, the reduction of metal artifact, and biochemical imaging of cartilage hold great promise.

Incidental bone tumors are, by definition, asymptomatic lesions that are discovered through routine radiographs obtained for other reasons. Generally, these lesions are benign and latent, requiring no further intervention except observation. However, occasionally these radiographs will detect benign aggressive processes or even malignant lesions that do require further treatment and referral to a tumor specialist. Oftentimes, there are characteristic findings on radiographs that are pathognomonic. Knowledge of these findings can simplify the treatment algorithm for a practicing general orthopaedist. This article will describe radiographic characteristics of benign and malignant bone lesions and their typical presentations. It will then focus on the types of bone lesions that are often found incidentally by routine radiography. Specific recommendations, including recommendation for referrals to orthopaedic tumor specialists, will be noted for lesions described. Most malignant lesions will present with pain and a constellation of history and physical exam findings that will signal the patient to seek medical care; although they will be mentioned for the sake of comparison and completeness, they will not be the focus of this review.

PURPOSE: Nonunions of the upper and lower extremity have been associated with pain and functional deficits. Recent studies have demonstrated that healing of these nonunions is associated with pain relief and both subjective and objective functional improvement. The purpose of this study was to determine which patient and surgical factors correlated with successful healing of a nonunion following surgical intervention. METHODS: Between September 2004 and February 2008, all patients with a "long bone nonunion" presenting to our academic trauma service were enrolled in a prospective data base. Baseline functional, demographic and pain status was obtained. Follow-up was obtained at 3, 6, and 12 months following surgical intervention, with longer follow-up as possible. One hundred and thirty-four patients with a variety of fracture nonunions were operated on by four different fellowship trained trauma surgeons with experience ranging from 2 to 15 years and variable nonunion surgery loads. Patients were stratified into one of three groups: 1. Patients who healed following one surgical intervention, 2. those who healed following multiple surgical intervention, and 3. those who failed to heal (remain ununited or underwent amputation). Healing was determined radiographically and clinically. Complications were recorded. Logistic regression analysis was performed to assess the cor-relation between specific baseline and surgical characteristics and healing. RESULTS: A minimum of 1 year follow-up was available for all 134 patients. One hundred and one patients (76%) with a mean age of 50 years healed at a mean of 6 months (range, 3 to 16) after one surgery. Twenty-two patients (16%) with a mean age of 47 years, who required more than one intervention, healed their nonunions at a mean of 11 months (range, 4 to 23). Eleven patients (8%) with a mean age of 50 years failed to heal at an average of 12 months follow-up. Complication rates were 11%, 68%, and 100% respectively for those who healed following one procedure, multiple procedures, and those who never healed. Higher surgeon volume (greater than 10 cases per year) was associated with 85% increased healing rates (OR = 0.15, 0.05-0.47 CI). The presence of a postoperative complication was associated with a 9 times lower likelihood of successful union as well (OR = 9.0, 2.6-31.7 CI). Patient age, sex, BMI, initial injury mechanism, tobacco use, and initial injury characteristics did not correlate with failure to heal. CONCLUSION: Our data is similar to other studies assessing outcomes following other complex reconstructive procedures. It appears that more experienced (higher volume) reconstructive surgeons and the development of fewer postoperative complications is associated with greater success following repair of a long bone nonunion. Infection at any point during treatment is associated with failure to achieve successful union.

OBJECTIVE: To evaluate the relationships between both quantitative and semiquantitative assessments of the degree of knee synovitis on 3T magnetic resonance imaging (MRI) and the severity of knee osteoarthritis (OA) on radiography. METHODS: Fifty-eight patients with knee OA underwent nonfluoroscopic fixed-flexion knee radiography. In addition, dynamic contrast-enhanced 3T MRI of the knees was performed, before and after gadolinium administration, to quantify synovial membrane volume (SV) as a measure of synovial proliferation (expressed as the quantitative SV), and semiquantitative measures of synovitis were also applied using both contrast-enhanced and unenhanced images. Two radiologists scored the knee radiographs using the Osteoarthritis Research Society International atlas; interreader agreement was assessed using kappa statistics and concordance correlation coefficients. Multiple linear and logistic regression analyses were used to assess associations among variables, while controlling for the effects of age, body mass index, sex, and meniscal extrusion. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for measures of disease activity. RESULTS: The Kellgren/Lawrence (K/L) grade of radiographic knee OA severity (beta = 0.78), the diseased compartment joint space width (dcJSW) (beta = -0.22), and the diseased compartment joint space narrowing (dcJSN) score (beta = 0.53) were each significantly associated with the quantitative SV (P = 0.0001, P = 0.0003, and P = 0.0001, respectively). Furthermore, the quantitative SV strongly correlated with the total volume of subchondral bone marrow lesions (BMLs) (beta = 0.22, P = 0.0003). The K/L grade, dcJSW, and dcJSN score were each significantly associated with the semiquantitative Boston Leeds Osteoarthritis Knee Score (BLOKS) for the extent of infrapatellar synovitis (OR 9.05 [95% CI 1.94, 42.3] for K/L grade; OR 0.75 [95% CI 0.54, 1.03] for dcJSW; and OR 2.22 [95% CI 1.15, 4.31] for dcJSN score) and extent of joint effusion (OR 5.75 [95% CI 1.23, 26.8] for K/L grade; OR 0.70 [95% CI 0.50, 0.98] for dcJSW; and OR 1.96 [95% CI 1.02, 3.74] for dcJSN score). In addition, the semiquantitative synovitis grade on contrast-enhanced MRI was significantly associated with the K/L grade (beta = 0.036, P = 0.0040) and dcJSN score (beta = 0.015, P = 0.0266), and also significantly associated with the BLOKS synovitis score. CONCLUSION: Synovitis is a characteristic feature of advancing knee OA and is significantly associated with the K/L grade, JSW, JSN score, and total volume of BMLs on radiographs. Furthermore, BLOKS scoring of synovitis on unenhanced MRI is associated with measurements of synovitis on contrast-enhanced MRI

Synovial chondrosarcoma is a rare tumor, seen most commonly arising from antecedent synovial chondromatosis, the more common benign entity. The distinction between the two can be difficult on the basis of clinical, imaging, and histologic criteria. The authors report a case of pathologically proven synovial chondrosarcoma of the hip in a 45-year-old male initially treated for presumed synovial chondromatosis. The case is made more unusual by the fact that no evidence of co-existent synovial chondromatosis was noted at histology. The literature as regards synovial chondrosarcoma, both de novo and secondary cases, is reviewed

OBJECTIVE: The objective of our study was to evaluate the diagnostic utility of conventional radiography for diagnosing bisphosphonate-related atypical subtrochanteric femoral fractures. MATERIALS AND METHODS: Retrospective interpretation of 38 radiographs of complete subtrochanteric and diaphyseal femoral fractures in two patient groups-one group being treated with bisphosphonates (19 fractures in 17 patients) and a second group not being treated with bisphosphonates (19 fractures in 19 patients)-was performed by three radiologists. The readers assessed four imaging criteria: focal lateral cortical thickening, transverse fracture, medial femoral spike, and fracture comminution. The odds ratios and the sensitivity, specificity, and accuracy of each imaging criterion as a predictor of bisphosphonate-related fractures were calculated. Similarly, the interobserver agreement and the sensitivity, specificity, and accuracy of diagnosing bisphosphonate-related fractures (i.e., atypical femoral fractures) were determined for the three readers. RESULTS: Among the candidate predictors of bisphosphonate-related fractures, focal lateral cortical thickening and transverse fracture had the highest odds ratios (76.4 and 10.1, respectively). Medial spike and comminution had odd ratios of 3.8 and 0.63, respectively. Focal lateral cortical thickening and transverse fracture were also the most accurate factors for detecting bisphosphonate-related fractures for all readers. The sensitivity, specificity, and overall accuracy for diagnosing bisphosphonate-related fractures were 94.7%, 100%, and 97.4% for reader 1; 94.7%, 68.4%, and 81.6% for reader 2; and 89.5%, 89.5%, and 89.5% for reader 3, respectively. The interobserver agreement was substantial (kappa > 0.61). CONCLUSION: Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures

'Skiving' is commonly used to refer to the condition when the subchondral plate is disrupted and the overlying cartilage physically displaced without the screw tip entering the joint. In this study we sought to define radiographic parameters of skiving and compare radiographs with computed tomography (CT) for accuracy in determining joint skiving. Cadaveric specimens of the distal radius were implanted with a volar plate and screws. Arthrotomies were performed to definitively assess the positions of the screws. Standard and anatomic tilt radiographs as well as CT were performed. Orthopaedic surgeons and radiologists evaluated the images and reported whether screw penetration or skiving had occurred. For screws which penetrated or skived, measurements were made to record the distances from the screw tips to the subchondral plate. Sensitivity, specificity and percent correct interpretations were 53%, 83%, 60% respectively for radiographs; and 100%, 72%, 69% for CT. Screws penetrating the articular surface protruded an average 2.3 mm (range 2-2.6 mm) from the subchondral plate and those skiving protruded 1.4 mm (range 1-1.8 mm). This study shows that articular skiving can occur with penetration of the subchondral plate of up to 1.8 mm. CT has a greater sensitivity and lower specificity in determining skiving compared to radiographs

This article is the second article in a two-part review on lumbar facet joint pathology. In this review, we discuss the current concepts and controversies regarding the proper diagnosis and management of patients presenting with presumed facet-mediated lower back pain. All efforts were made to include the most relevant literature from the fields of radiology, orthopaedics, physiatry, and pain management. Our focus in this article is on presenting the evidence supporting or refuting the most commonly employed injection-based therapies for facet-mediated lower back pain