Return to Sport After Revision ACL Reconstruction: A Comparative Cohort Study of Outcomes After Single- Versus Multiple-Revision Surgeries.

Background: The return-to-sport rate at 2 years after multiple-revision anterior cruciate ligament (ACL) reconstructions has not been evaluated. Hypothesis: It was hypothesized that patients who undergo multiple-revision ACL reconstructions would have a lower return-to-sport rate at 2 years after surgery than those who undergo a single-revision reconstruction. Furthermore, it was hypothesized that the multiple-revision group would have lower functional scores. Study Design: Cohort study; Level of evidence, 3. Methods: A single-center cohort study in patients who underwent revision ACL reconstruction was begun in 2012. This study included 2 groups: Patients who underwent a single revision, and those who underwent multiple revisions. The main evaluation criterion was the return to sport at the 2-year follow-up. The secondary criteria were the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, and ACL-Return to Sport after Injury (ACL-RSI) functional knee scores at the 1- and 2-year follow-ups. Results: A total of 322 patients (single-revision group: n = 302; multiple-revision group: n = 20) were included. A significant difference in the percentage of patients who stopped all sports activity was found between the 2 groups at 2 years (single-revision group: 19.4%; multiple-revision group: 50%). The return-to-sport rate at the same or lower level of performance was higher in the single-revision group as well (17% vs 14.3% for return at the same level; 45.6% vs 14.3% for return at a lower level; P = .03). At the 2-year follow-up, the functional scores of the single-revision group were significantly higher those than in the multiple-revision group: IKDC (77.7 ± 13.82 vs 64.79 ± 15.22; P < .001), KOOS (72.66 ± 17.63 vs 52.5 ± 15.64; P < .001), Lysholm (84.05 ± 11.88 vs 72.5 ± 13.49; P < .001), and ACL-RSI (52.34 ± 21.83 vs 46.43 ± 14.8; P = .0036). Conclusion: Only a small percentage of patients returned to the same level of sport after single- revision and multiple-revision ACL reconstruction, yet significantly more in the former. More patients who underwent multiple revisions gave up their sport. Functional scores were higher for single-revision than multiple-revision surgeries.

A primer on skeletal dysplasias.

Skeletal dysplasia encompasses a heterogeneous group of over 400 genetic disorders. They are individually rare, but collectively rather common with an approximate incidence of 1/5000. Thus, radiologists occasionally encounter skeletal dysplasias in their daily practices, and the topic is commonly brought up in radiology board examinations across the world. However, many radiologists and trainees struggle with this issue because of the lack of proper resources. The radiological diagnosis of skeletal dysplasias primarily rests on pattern recognition-a method that is often called the "Aunt Minnie" approach. Most skeletal dysplasias have an identifiable pattern of skeletal changes composed of unique findings and even pathognomonic findings. Thus, skeletal dysplasias are the best example to which the Aunt Minnie approach is readily applicable.

Influence of Physical Activity Level on Composite Indices of Femoral Neck Strength in a Group of Young Overweight Men.

The aim of the present study was to explore the influence of physical activity level on composite indices of femoral neck strength (compression strength index [CSI], bending strength index, and impact strength index) in a group of young overweight men. To do so, we compared composite indices of femoral neck strength in active overweight men and insufficiently active overweight men. They were divided into 2 groups based on their physical activity level: 70 active overweight men (engaging in more than 150 minutes of physical activity per week; 8.7 ± 4.8 h/wk) and 26 insufficiently active overweight men (engaging in less than 150 minutes of physical activity per week; 1.2 ± 0.7 h/wk). Height (m) and weight (kg) were measured, and body mass index (kg/m2) was calculated. Bone mineral density was measured by dual-energy X-ray absorptiometry at whole body, lumbar spine, total hip, and femoral neck. Body weight, lean mass, fat mass, and body mass index were not significantly different between the 2 groups. CSI, bending strength index, and impact strength index were significantly higher in active overweight men compared to insufficiently active overweight men. After adjustment for age, physical activity (h/wk) and lean mass, only CSI remained higher in active overweight men compared to insufficiently active overweight men. This study suggests that, in young overweight men, being active (engaging in more than 150 minutes of physical activity per week) is associated with greater composite indices of femoral neck strength. To our knowledge, this is the first study that finds a significant difference regarding composite indices of femoral neck strength between 2 groups of young overweight men with different levels of physical activity.

Does the induced membrane have antibacterial properties? An experimental rat model of a chronic infected nonunion.

INTRODUCTION: The Masquelet procedure proved its efficiency in treating infected nonunion filling bony gaps up to 25 cm. Yet the use of local antibiotics is still questionable in the daily practice with lack of evidence regarding its usefulness in controlling infection. An experimental rat model is put in place to study the antibacterial properties of the induced membrane produced during the first stage of Masquelet. METHOD: Twenty-three-month-old wistar male rats are inoculated with a 0.5 mL solution of 10^8 CFU/mL MRSA over a critical fracture done on the right femur. Six weeks later, remaining 11 rats exhibiting signs of a chronic infection with a sinus tract and oozing pus along with radiological nonunion are used for a first stage Masquelet procedure. They are randomly divided into two groups with six rats having no local antibiotic in the cement mixture and five rats having 3 g of vancomycin mixed with gentamycin loaded cement. Six weeks later (twelve weeks from baseline), all eleven rats are euthanized and blood samples for C-reactive protein are withdrawn. The induced membrane is identified and resected along with bone fragments and sent for cultures and pathology. RESULTS: MRSA is isolated in the cultures of all six rats in the first group where no local antibiotic was added. Altered polymorphonuclears with abscess and pus are noted on four of six pathology samples. However in the second group where local antibiotics were added, three out of five rats exhibited eradication of MRSA (p = 0.034) and all samples did not exhibit clear infection signs on pathology. A pyo-epithelioid over a foreign body reaction is seen predominantly in this group demonstrating a regenerative process. DISCUSSION: The induced membrane does not have antimicrobial properties capable of overcoming an infected nonunion on its own. When local antibiotics were added during the first stage of the Masquelet procedure, new bone formation occurred indicating the need to control an infection in order for bone union to occur. CONCLUSION: Local antibiotics use in adjunction to extensive debridement is advisable during the first stage of a Masquelet procedure for an infected nonunion.

Physical Performance Variables and Bone Mineral Density in a Group of Young Overweight and Obese Men.

The aim of this study was to explore the relationships between performances obtained in different physical tests and bone parameters (bone mineral density [BMD], bone mineral content, hip geometry indices, and trabecular bone score [TBS]) in a group of young Lebanese overweight and obese adult men. Fifty-two overweight and/or obese (body mass index > 25 kg/m2) young men whose ages range from 18 to 35 yr participated in this study. Weight and height were measured, and body mass index was calculated. Body composition, BMD, cross-sectional area and section modulus (Z) of the femoral neck (FN), and TBS were measured by dual-energy X-ray absorptiometry. Maximum oxygen consumption (VO2 max, in liter per minute) was determined by direct measurement while exercising on a medical treadmill. One-repetition-maximum half-squat and maximum power (P max) of the lower limbs were measured using validated exercises. Lean mass was a positive determinant of whole-body bone mineral content (r = 0.71, p < 0.001), FN cross-sectional area (r = 0.51, p < 0.001), and FN Z (r = 0.58, p < 0.001). VO2 max (in liter per minute) was a positive determinant of whole-body BMD (r = 0.47, p < 0.001), total hip BMD (r = 0.43, p < 0.01), and FN BMD (r = 0.42, p < 0.01). VO2 max (in milliliter per minute per kilogram) was a positive determinant of TBS (r = 0.30, p < 0.05). One repetition maximum was a positive determinant of L1-L4 BMD (r = 0.33, p < 0.05). This study suggests that VO2 max (in liter per minute) is a positive determinant of BMD, and VO2 max (in milliliter per minute per kilogram) is a positive determinant of TBS in overweight and obese men.

Bone contusion progression from traumatic knee injury: association of rate of contusion resolution with injury severity.

BACKGROUND: Bone contusions are frequently encountered in magnetic resonance imaging (MRI) evaluation of knee anterior cruciate ligament (ACL) injuries. Their role as indicators of injury severity remains unclear, primarily due to indeterminate levels of joint injury forces and to a lack of preinjury imaging. PURPOSE: The purpose of this study was to 1) quantify bone contusion pathogenesis following traumatic joint injuries using fixed imaging follow-ups, and 2) assess the feasibility of using longitudinal bone contusion volumes as an indicator of knee injury severity. STUDY DESIGN: Prospective sequential MRI follow-ups of a goat cohort exposed to controlled stifle trauma in vivo were compared to parallel clinical MRI follow-ups of a human ACL tear patient series. METHODS: Reproducible cartilage impact damage of various energy magnitudes was applied in a survival goat model, coupled with partial resection of anterior portions of medial menisci. Both emulate injury patterns to the knee osteochondral structures commonly encountered in human ACL injury imaging as well as instability from resultant ligament laxity. Longitudinal clinical MRI sequences portrayed stifle bone contusion evolution through 6 months after the inciting event. RESULTS: In the first 2 weeks, biological response variability dominated the whole-joint response with no apparent correlation to trauma severity. Control goats subjected to partial meniscectomy alone exhibited minimal bone response. Thereafter, 0.6 J impact bone contusions portrayed a faster rate of resolution than those induced by 1.2 J cartilage impacts. CONCLUSION: Bone contusion sizes combined with time of persistence are likely better measures of joint injury severity than isolated bone contusion volume.

Bone Variables in Active Overweight/Obese Men and Sedentary Overweight/Obese Men.

The aim of this study was to compare bone variables in active overweight/obese men and sedentary overweight/obese men. Thirty-seven active overweight/obese men and 45 sedentary overweight/obese men participated in this study. Weight and height were measured, and body mass index was calculated. Body composition and bone variables (bone mineral content [BMC], bone mineral density [BMD], geometric indices of hip bone strength, and trabecular bone score) were measured by DXA. Physical activity level, daily calcium intake, daily protein intake, and sleep duration were measured by validated questionnaires. Maximum oxygen consumption (VO2 max) was determined by direct measurement while exercising on a medical treadmill. One-repetition-maximum half-squat of the lower limbs was measured using a validated protocol. Body weight and body mass index were higher in sedentary overweight/obese men than in active overweight/obese men. In the whole population (n = 82), VO2 max (in liter per minute), lean mass, and one-repetition-maximum half-squat were positively correlated to BMC, BMD, and geometric indices of hip bone strength (cross-sectional area and section modulus [Z] of the femoral neck [FN]). After adjusting for body weight using a 1-way analysis of covariance, active overweight/obese men displayed higher whole-body BMC, lumbar spine BMD, total hip BMD, FN BMD, FN cross-sectional area, and FN Z values than sedentary overweight/obese men. In conclusion, the current study suggests that physical activity level positively affects bone variables in overweight/obese men. Optimizing lean mass and muscular strength of the lower limbs can help to prevent osteoporosis in overweight and obese men.

Pediatric stress fractures: a pictorial essay.

More children are participating in organized and recreational athletics at a younger age. It has been well documented that increased athletic specialization and year-round activities have resulted in higher incidences of overuse injuries, including stress fractures and stress reactions. Initially, stress fractures can be radiographically occult. Continued stress on the injured bone or cartilage can lead to progressive radiographic changes. Because of the prevalence of these injuries, both orthopedic surgeons and radiologists should be aware of the radiographic and magnetic resonance imaging (MRI) features of common stress fractures in children. This article reviews frequently encountered stress fractures involving various bones in the pediatric population.

Performance physique et densité minérale osseuse chez de jeunes adultes libanais.

Introduction: The aim of this study was to explore the relationships between performances obtained in different physical tests and bone parameters (bone mineral density (BMD) and bone mineral content (BMC)) in a group of young Lebanese adults. Methods: One hundred and six young Lebanese adults (45 women and 61 men) whose ages range from 17 to 34 years participated in this study. Weight and height were measured, and body mass index (BMI) was calculated. Daily calcium intake, daily protein intake and physical activity level (h/week) were evaluated using validated questionnaires. The level of physical performance was measured using several physical tests: vertical-jump test, standing long jump test, 3-jumptest, 5-jump-test and 1-RM half-squat. Body composition, bone mineral content (BMC) and BMD at whole body (WB), lumbar spine (L2-L4), total hip (TH) and femoral neck (FN) were measured by dual-energy X-ray absorptiometry (DXA). Results: In women, height, lean mass, 1- RM half-squat and performances obtained in three physical tests (vertical jump test, 5-jump-test and 1-RM halfsquat) were positively correlated to BMD and BMC. In men, lean mass and 1-RM half-squat were positively correlated to BMD and BMC. Conclusion: This study suggests that lean mass and maximum strength obtained in half-squat are positively correlated to BMD in young adults.

Diagnostic accuracy of 3D color volume-rendered CT images for peroneal tendon dislocation in patients with acute calcaneal fractures.

BACKGROUND: Use of three-dimensional (3D) color volume-rendered (VR) images has been reported to be more time-efficient compared to that of cross-sectional computed tomography (CT) images for the diagnosis of peroneal tendon dislocation. However, the diagnostic performance of this technique has not been studied. PURPOSE: To test diagnostic accuracy of 3D color VR CT images of ankle for peroneal tendon dislocation in patients with acute calcaneal fractures. MATERIAL AND METHODS: The study consisted of 121 ankle CT studies from 105 consecutive patients (85 men, 20 women; mean age, 42 years; age range, 16-75 years) with acute calcaneal fractures. Peroneal tendon dislocation was diagnosed on multiplanar CT images by consensus of two experienced musculoskeletal radiologists, which served as the reference standard. Three other musculoskeletal radiologists independently reviewed 3D images alone on a workstation. The readers determined whether or not there was peroneal tendon dislocation using three degrees of certainty (definite, probable, and possible). Diagnostic performance of 3D images for peroneal tendon dislocation was evaluated by calculating the sensitivities, specificities, and area under the receiver-operating characteristic (ROC) curves. RESULTS: Forty-eight (40%) out of 121 studies showed peroneal tendon dislocation based on the expert readings using multiplanar reformatted images. Sensitivities/specificities of 3D images measured 0.92/0.81, 0.88/0.90, and 0.81/0.92 for three readers, respectively. The area under the proper binormal ROC curve based on all three readers (0.93, 0.94, and 0.92) measured 0.93 with a 95% confidence interval of 0.89-0.98. CONCLUSION: Diagnostic accuracy of 3D images is comparable to, but not as good as that of MPR images for the diagnosis of peroneal tendon dislocation in patients with acute calcaneal fractures.

Masses in the extensor mechanism of the knee: an unusual presentation of gout.

Tophaceous gout presenting as a soft tissue mass in an unusual location can pose a diagnostic challenge for radiologists. Tophi sometimes occur in a variety of unusual anatomic locations making them difficult to distinguish from tumors such as sarcomas. We report two cases of gout in the extensor mechanism of the knee, with imaging findings that were initially concerning for a neoplasm. One mass occurred in the patellar tendon and the other mass involved the quadriceps tendon. Both lesions had enigmatic imaging findings and to arrive at a definitive diagnosis, incisional biopsies were performed.

Clinical role of radiography for thoracic spine fractures in daily practice in the MDCT era: a retrospective review of 255 trauma patients.

PURPOSE: To retrospectively assess the diagnostic efficacy of radiography in detecting vertebral body fractures of the thoracic spine compared with MDCT, to assess the confounding factors reducing the diagnostic efficacy, and to investigate the outcomes of radiographically overlooked patients. MATERIALS AND METHODS: Two hundred fifty-five patients suspected of thoracic spine fractures were enrolled. We assessed the diagnostic efficacy of radiography for the patients sub-grouped based on five confounding factors: chest abnormalities, head injuries, cervical spine fractures, upper extremity injuries, and age of 65 years or older. We investigated the outcomes of radiographically overlooked patients. RESULTS: Three hundred fifty-one vertebral body fractures were detected. The per-fracture sensitivities and specificities were 55 % and 94 % for vertebral body fractures and 41 and 99 % for unstable fractures. In patients with upper extremity injuries or aged 65 years or older, radiography was less sensitive in detecting the unstable fractures (P < 0.05). Nineteen patients were overlooked by radiography; two had neurological deficits and needed surgical fixation; 15 with no neurological deficit were conservatively treated with uneventful outcomes. CONCLUSION: Radiography had low sensitivity but high specificity. In daily practice, primary use of MDCT is beneficial for patients with neurological deficit or upper extremity injuries or elderly patients.

SAPHO syndrome--a pictorial assay.

SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome is a distinct clinical entity representing involvement of the musculoskeletal and dermatologic systems. It is well known to rheumatologists because of characteristic skin manifestations and polyarthropathy. However, few reports exist in the orthopaedic literature. It is important to be aware of sAPHO syndrome as it can mimic some of the more common disease entities such as infection, tumor, and other inflammatory arthropathies. Anterior chest wall pain centered at sternoclavicular and sternocostal joints is an important and characteristic clinical finding which can point to its diagnosis. A patient may undergo different diagnostic tests and invasive procedures such as biopsies before a diagnosis is made. Imaging can be helpful by offering a detailed evaluation of the abnormalities. More importantly it helps in revealing subclinical foci of involvement due to the polyostotic nature of the disease. The treatment is mostly nonsurgical. NSAIDS are the first line agents. However multiple new agents are being used for refractory cases. Surgery is reserved to treat complications.

Early spondylodiscitis presenting with single vertebral body involvement: a report of two cases.

Infectious spondylodiscitis is an uncommon disease with increasing incidence that typically presents with abnormalities in two adjacent vertebral bodies and the intervening disk. We describe two cases that initially presented with imaging abnormalities in only a single vertebral body. Both patients had a history of lumbar back pain and elevated inflammatory markers, but the lack of classical spondylodiscitis imaging findings led to diagnostic delay and confusion. It is likely that the incidence of atypical presentations of spondylodiscitis will increase as the disease incidence increases and imaging is performed at an earlier stage. It is important to recognize the disease early because early diagnosis is the key to preventing serious complications like epidural abscess and spinal cord compression.

Conical utility of CT-guided biopsies in orthopaedic oncology.

BACKGROUND: CT-guided biopsy is a minimally invasive diagnostic method of evaluating musculoskeletal lesions. Other options include incisional and excisional biopsy with the possibility of intraoperative frozen section. The clinician's decision to order a CT-guided biopsy requires an understanding of the likelihood that this biopsy will affect treatment This requires an understanding of both diagnostic yield and accuracy. Furthermore, the clinical utility of a biopsy is affected by factors other than the yield and accuracy as the clinical setting may render a technically diagnostic biopsy unhelpful. METHODS: A retrospective review of the electronic record at an orthopedic oncology referral center identified all patients who had undergone CT-guided percutaneous needle biopsy of musculoskeletal lesions after being evaluated by an orthopedic oncologist in clinic over a period of 5 years. 53 CT-guided biopsies of bone lesions and 16 CT-guided biopsies of soft tissue lesions were identified. The diagnostic yield (rate of obtaining tissue from which the pathologist could report a diagnosis) and clinical utility (rate at which biopsy results guided treatment decisions) were calculated and statistically compared. RESULTS: The overall diagnostic yield of CT-guided bone biopsies was 94% (50 of 53 biopsies) and the clinical utility was 70% (37 of 53 biopsies). In the first 2 years of the study the diagnostic yield was 95% (21 of 22 biopsies) and the clinical utility was 86% (19 of 22 biopsies). In the remaining 3 years the diagnostic yield was 91% (28 of 31 biopsies) and the clinical utility was 58% (18 of 31 biopsies). This decrease in clinical utility over time was statistically significant (p = 0.01). Suspicion of metastasis resulted in a diagnostic yield of 100% (11/11) and a clinical utility of 91% (10/11). Suspicion of primary tumor resulted in a diagnostic yield and clinical utility of 93% (39/42) and 67% (28/42), respectively. This difference in clinical utility was statistically significant (p = 0.02). The diagnostic yield of CT-guided soft tissue biopsies was 75% (12 of 16 biopsies) and the clinical utility was 69% (11 of 16 biopsies). The diagnostic yield was significantly lower for soft tissue biopsy than bone biopsy (p = 0.01). There was no relationship between the rate of diagnostic biopsies and the evaluating pathologist or the location of the lesion within the body. CONCLUSIONS: CT-guided biopsy is useful in the diagnosis of musculoskeletal lesions, however, its clinical utility is substantially lower than its diagnostic accuracy and yield due to a significant rate of diagnostic biopsies that fail to guide treatment, particularly when a primary lesion is suspected. The disparity in clinical utility based on preoperative suspicion of metastasis was even greater in our study than previously shown. CT-guided percutaneous needle biopsy is much more likely to guide treatment in the setting of suspected bone metastasis as opposed to biopsies of suspected primary bone lesions and soft tissue lesions.

Lipoma arborescens of the subdeltoid bursa: a case report.

Lipoma arborescens is a benign, diffuse villous proliferation of the synovium characterized by replacement of the subsynovial tissue by mature adipocytes. Its etiology is unknown and fewer than 100 cases have been reported. It resembles other collections of subsynovial fat, the only difference being its large size and villous macroscopic appearance. It typically presents in patients in their fifth through seventh decades of life. It is most commonly monoarticular and most frequently affects the suprapatellar pouch of the knee. There have been reports of involvement of the hip, shoulder, wrist, elbow, ankle, and associated bursae. To our knowledge there have been only three previous cases of lipoma arborescens of the subdeltoid bursa in the literature. We report on a case of unilateral lipoma arborescens of the subdeltoid bursa in an elderly patient presenting as a shoulder mass.

Cervical facet joint septic arthritis: a case report.

Facet joint septic arthritis is a rare but severe infection with the possibility of significant morbidity resulting from local or systemic spread of the infection. Pain is the most common complaint on presentation followed by fever, then neurologic impairment. While the lumbar spine is involved in the vast majority of cases presented in the literature, the case presented here occurred in the cervical spine. The patient presented with a three week history of neck and left shoulder pain and was diagnosed by MRI when his pain did not respond to analgesics and muscle relaxants. The only predisposing factor was a history of diabetes mellitus and the infection most likely resulted from hematogenous spread. MRI is highly sensitive in diagnosing septic arthritis and it is the preferred modality for demonstrating the extent of infection and secondary complications including epidural and paraspinal abscesses as seen in this case. Without familiarity with this entity's predisposing factors, clinical symptoms and appropriate lab/imaging work up, many patients experience a delay in diagnosis. Treatment involves long term parenteral antibiotics or percutaneous drainage. Surgical debridement is reserved for cases with severe neurologic impairment. The incidence of facet joint septic arthritis is increasing likely related to patient factors (increasing number of patients >50 yo, immunosuppressed patients, etc), advancement in imaging technology, availability of MRI, and heightened awareness of this rare infection which is the aim of this case presentation.