The Future of Artificial Intelligence in Sports Medicine and Return to Play.

Artificial intelligence (AI) has shown tremendous growth over the last decade, with the more recent development of clinical applications in health care. The ability of AI to synthesize large amounts of complex data automatically allows health care providers to access previously unavailable metrics and thus enhance and personalize patient care. These innovations include AI-assisted diagnostic tools, prediction models for each treatment pathway, and various tools for workflow optimization. The extension of AI into sports medicine is still early, but numerous AI-driven algorithms, devices, and research initiatives have delved into predicting and preventing athlete injury, aiding in injury assessment, optimizing recovery plans, monitoring rehabilitation progress, and predicting return to play.

Return to Play in the Professional Athlete.

The management of any injury in elite athletes poses unique challenges distinct from the general population because the goal is rapid recovery and return to play (RTP) while simultaneously managing residual symptoms and minimizing risk of reinjury. The time required for treatment, recovery, and return to peak performance can have consequences for both the athlete and his or her team: financial implications, psychological stressors, team dynamics, and future performance. RTP after an injury in the professional athlete requires a complex decision-making process with many stakeholders. Several factors influence this decision, not the least of which is the type and mechanism of injury. This article provides an overview of the RTP process including nonmedical factors that may influence this decision, common injuries seen in professional athletes, injury patterns particular to certain popular sports, and imaging guidelines for such injuries.

Pediatric Shoulder Girdle.

The pediatric shoulder girdle is a complex anatomical structure uniting the upper extremity and trunk. The osseous structures, their articulations, and the surrounding soft tissue support structures (muscles, tendons, and ligaments) allow for a wide range of motion at the shoulder. Growth and maturation of the components at the shoulder girdle vary, particularly the osseous structures. This characteristic renders interpretation of imaging of the pediatric shoulder girdle more challenging because normal or variant anatomy can be confused for pathology. We review the physiologic growth and maturation of the shoulder girdle with special emphasis on the development of the bones and their articulations. The role of various imaging modalities and the common osseous and soft tissue variants in the pediatric shoulder are also discussed.

Presence of subchondral fracture in cases diagnosed as transient osteoporosis of the hip: a retrospective independent reader-based study.

OBJECTIVE: Transient osteoporosis of the hip (TOH) is an uncommon, typically self-limited diagnosis of uncertain etiology. We hypothesize that TOH represents an underlying subchondral fracture, and a discrete fracture line can often be detected on high-resolution MRI. MATERIALS AND METHODS: A retrospective PACS query identified patients meeting imaging criteria for TOH with intense bone marrow edema (BME) in the femoral head on MRI. Those with poor quality studies, other underlying pathologies, or antecedent trauma were excluded. Three musculoskeletal radiologists independently reviewed each case for presence of a definite subchondral fracture line on small field of view (FOV) MR images of the affected hip. Extent of BME, reciprocal acetabular BME, and joint effusion size were also recorded. Binomial logistic regression was performed to determine statistically significant predictors of subchondral fracture. RESULTS: Fifty patients met inclusion criteria (29 females, 0 pregnant). Mean age was 62±12 years (range 35-84). Average duration of symptoms before MRI was 102±135 days. Ten patients had bone densitometry within 2 years of MRI, six demonstrating osteopenia or osteoporosis. Subchondral fractures were unanimously identified in 44/50 (88%). Interclass correlation coefficient with absolute agreement was 0.73, 95% CI (0.57-0.84), indicating near-excellent agreement. Most cases demonstrated a large joint effusion (23/50, 46%) and acetabular BME (31/50, 62%). Increasing size of joint effusion was a statistically significant predictor of subchondral fracture (p=0.05), with 6.9 higher odds. There was a strong correlation with osteopenia/osteoporosis and fracture (p<0.001). CONCLUSION: Discrete subchondral fractures were identified unanimously on small FOV imaging in the majority of TOH cases.

Bone bruise vs. non-displaced fracture on MRI: a novel grading system for predicting return-to-play.

OBJECTIVE: To devise an MRI grading scheme for osseous contusion patterns in elite hockey players for predicting return-to-play (RTP). METHODS: A retrospective review was performed to identify traumatic lower extremity osseous injuries in professional hockey players. A total of 28 injuries (17 players) were identified over a 10-year period. All had MRIs acquired at ≥ 1.5 T within a mean interval of 2 days from initial injury. MRIs were retrospectively reviewed by 3 musculoskeletal radiologists for osseous contusion pattern, classified as grade 1 (mild), 2 (moderate), or 3 (severe). Grade 3 contusions were further subdivided by the presence or absence of fracture, defined as discrete cortical disruption on MRI or follow-up CT. RTP was calculated from date of injury to next game played based on game log data. Statistical analysis was performed using ANOVA and post hoc unpaired t test. RESULTS: Mean RTP for grade 1, 2, and 3 injuries was 2.8, 4.5, and 20.3 days, respectively. Grade 3 injuries without and with cortical fractures had mean RTP of 18.3 and 21.4 days, respectively. ANOVA analysis between groups achieved statistical significance (p < 0.001). Post hoc t test demonstrated statistically significant differences between grade 3 and grades 1 (p < 0.001) and 2 (p < 0.001) injuries. There was no statistical difference in RTP between grade 3 subgroups without and with fracture (p = 0.327). CONCLUSION: We propose a novel MRI grading system for assessing severity of osseous contusions and predicting RTP. Clinically, there was no statistically significant difference in RTP between severe osseous contusions and nondisplaced fractures in elite hockey players.

Extensor mechanism tendinopathy in patients with lateral patellar maltracking.

OBJECTIVE: Patellar maltracking is an important subset of patellofemoral pain syndrome. We hypothesize that maltracking patients have an increased incidence of extensor mechanism dysfunction due to repetitive attempts at stabilization of the patella. Our purpose is to delineate imaging features to identify maltracking patients at risk for extensor mechanism tendinopathy. MATERIALS AND METHODS: Retrospective review of knee MRIs performed for anterior knee pain over a year was conducted to identify 218 studies with imaging findings of maltracking. The cases were evaluated for the presence and degree of patellar and quadriceps tendinopathy, tibial tuberosity-trochlear groove distance (TT-TG) and the distribution and grade of patellofemoral chondrosis. Cases were compared to 100 healthy, age-matched control knee MRIs. RESULTS: The mean age of maltracking patients with either patellar or quadriceps tendinosis was 41.2 years versus 48.2 years in the control population (p = 0.037). The TT-TG was significantly higher in maltracking patients with either patellar or quadriceps tendinosis at 16.49 mm versus 14.99 mm (p = 0.006). Maltrackers with isolated lateral patellofemoral chondrosis had a higher mean TT-TG at 17.4 mm versus 15.4 mm (p = 0.007). Extensor mechanism tendinosis was increased in the maltracking population compared to the controls at 57.8% versus 27.3% (p = 0.004). CONCLUSION: Extensor mechanism tendinosis is more common in the maltracking population and occurs at a younger age. TT-TG distance is significantly increased in patients with extensor mechanism dysfunction and in patients with isolated lateral patellofemoral chondrosis. TT-TG measurement can be used independently to identifying maltrackers who may be at risk for future complications.

Prevalence of lateral patellofemoral maltracking and associated complications in patients with Osgood Schlatter disease.

OBJECTIVE: To evaluate adults with history of Osgood Schlatter disease (OSD) for imaging features of lateral patellofemoral maltracking. METHODS: In a span of four years, 10,181 unique non-contrast knee MRIs were performed on patients aged 20-50. Patients with acute trauma, prior surgery, and synovial pathologies were excluded. 171 exams had imaging findings of OSD, and an age-matched control group of 342 patients without OSD was randomly selected. Two radiologists retrospectively reviewed MRIs for features of lateral patellofemoral maltracking. Maltracking was defined as edema in superolateral Hoffa's fat or a tibial tuberosity-trochlear groove (TT-TG) distance ≥20 mm with either patellar tilt/translation. Binomial logistic regression identified predictors of maltracking in OSD. Optimal TT-TG distance to indicate maltracking was determined by receiver operating characteristic curve. RESULTS: 59% (101/171) of the knees with OSD showed findings of maltracking, with patella alta, trochlear dysplasia, and quadriceps tendinosis as significant predictors of maltracking (p < 0.001). Patellofemoral chondrosis was present in 63% (107/171), with maltracking contributing to higher grade chondrosis more so than increasing age (OR 8.4 versus 1.07). 13 mm was the optimal cut-off TT-TG distance to indicate maltracking (sensitivity 83%, specificity 80%). The prevalence of maltracking in the control group was 15% (p < 0.001 compared with the OSD group). CONCLUSION: Adults with sequelae of OSD are at high risk of maltracking and are likely to develop patellofemoral chondrosis. A lower threshold for identifying maltracking patients, including a lower cut-off TT-TG distance can help identify those at risk. Radiologists should maintain a high index of suspicion for maltracking in adults with OSD to guide clinical intervention.

Comparable clinical outcomes using knotless and knot-tying anchors for arthroscopic capsulolabral repair in recurrent anterior glenohumeral instability at mean 5-year follow-up.

PURPOSE: To compare rates of recurrent instability, revision surgery and functional outcomes following arthroscopic anterior capsulolabral repair for recurrent anterior instability using knot-tying versus knotless suture anchor techniques. METHODS:  Patients who had undergone arthroscopic anterior labrum and capsular repair for recurrent anterior glenohumeral instability using knotless anchors were identified. Those with minimum 2-year follow-up were matched (1:2) to knot-tying anchor repair patients. Rates of failure and recurrent instability were compared, as well as Visual Analog Scale (VAS), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), University of California Los Angeles (UCLA) and Rowe scores. RESULTS: One hundred and two patients (89 males, 13 females) with a mean age of 24.3 ± 9.6 were included. Repair was performed with knotless anchors in 34 and knot-tying anchors in 68 shoulders. At mean follow-up of 4.8 ± 2.5 years, re-dislocation rates between groups were not significantly different (knotless anchor: 9% versus knot-tying group: 15%, n.s.), but the knot-tying group showed a higher re-subluxation rate (p = 0.039). 12 (18%) revisions were performed in the knot-tying group at a mean 2.9 years after surgery and 1 (3%) revision in the knotless anchors group at 1.4 years (n.s.). There was no difference in mean VAS with use (1.3 ± 1.9 versus 0.8 ± 1.5, n.s.), SANE scores (91.8 ± 12.7 versus 92.0 ± 11.0, n.s.), QuickDASH scores (4.1 ± 5.5 versus 3.0 ± 6.5, n.s.), UCLA Shoulder Score (32.5 ± 3.6 versus 33.2 ± 3.1, n.s.), or Rowe scores (90.5 ± 18.5 versus 92.2 ± 16.6, n.s.) between knotless and knot-tying groups, respectively. VAS at rest was higher in the knotless group (0.7 ± 1.5 vs 0.1 ± 0.4, p = 0.021). CONCLUSIONS: Knotless anchors demonstrated similar rates of re-dislocation and revision surgery, and lower rates of recurrent subluxation, compared to knot-tying anchors. Patients achieved good-to-excellent functional outcomes. This supports the efficacy of knotless anchors as an alternative to knot-tying anchors for arthroscopic anterior labral repair of recurrent anterior shoulder dislocation. LEVEL OF EVIDENCE: III.

Talus Partitus: a review of five cases diagnosed by MRI.

Talus partitus is a rare skeletal developmental abnormality characterized by a split of the posterior talar bone in the coronal plane. Patients with talus partitus typically present with posterior ankle pain and instability, often displaying varying degrees of chondrosis and secondary degenerative change on imaging. To date, only few case reports describing the imaging appearance of talus partitus have been published. The majority of these publications are limited to radiographic and computed tomography (CT) imaging findings, despite the ubiquity of magnetic resonance imaging (MRI). To the authors' knowledge, there is little description of typical MRI findings of the symptomatic talus partitus in the radiologic literature. We present a series of five cases of talus partitus identified on MRI and examine pitfalls in diagnosis, differential considerations, pathophysiology, and treatment options.

Painful type II os naviculare: introduction of a standardized, reproducible classification system.

OBJECTIVE: To provide a novel MRI classification system for the symptomatic type II os naviculare by creating a standardized grading of associated bone marrow edema (BME) and correlating with patient symptoms. METHODS: BME was classified on an ordinal scale: grade 1, faint signal immediately adjacent to the synchondrosis; grade 2, intermediate signal within the os and navicular tuberosity without extending to the navicular body; grade 3, intense signal extending to the navicular body. BME on 59 MRIs was independently graded by three radiologists. Inter- and intra-observer agreement was analyzed using intraclass correlation coefficient. Univariate and multivariate analyses assessed for patient and imaging characteristics predictive of subjective pain score. A cohort of 82 patients without BME represented a control group. RESULTS: Inter-observer agreement of BME grade was 0.95 (CI 0.93-0.97) and intra-observer was 0.92 (CI 0.87-0.96), indicating excellent agreement. In patients with BME, predictors of more severe pain were longer duration of pain (p = 0.02) and presence of soft tissue edema overlying the os naviculare (p < 0.001). One hundred percent of subjects with BME localized their pain to the medial midfoot (59/59) versus 25.6% (21/82) of controls (p < 0.001). CONCLUSIONS: This novel grading system provides reliable quantification of BME associated with os naviculare, which is a specific cause of medial foot/ankle pain. Early diagnosis is important as pain severity worsens with longer duration of symptoms. Pain severity is correlated with soft tissue edema overlying the os, which may be secondary to extrinsic compression, reactive to biomechanical stress, or reflect direct trauma.

Advanced MRI Techniques for Assessing Marrow Abnormalities of the Spine.

It is important to review the physics of current MRI developments in nontraumatic spinal imaging and their specific applications for assessing the bone marrow. Techniques include chemical shift imaging and its use in differentiating aggressive from benign lesions and in confirming the presence of diffuse red marrow conversion, which may mimic diffuse marrow infiltration in metastatic disease. The principles of dynamic contrast MRI and its uses in multiple myeloma and discriminating between postoperative change/scarring versus recurrence in soft-tissue tumors warrant discussion. The basic physics of diffusion-weighted imaging (DWI) in bone marrow pathologies are distinguished from the principles of DWI as applied to solid organs, and DWI is used in the staging of multiple myeloma and in differentiating between benign versus malignant compressive vertebral fractures. The orthopaedic surgeon should be knowledgeable about whole-body MRI principles and its uses in staging multiple myeloma and sarcoma. Knowledge about PET-MRI principles and its limitations as well as its potential use in assessing the subchondral bone plate and bony remodeling is also important. This technique may play a role in the future for predicting progression to osteoarthritis.

Smoking, unemployment, female sex, obesity, and medication use yield worse outcomes in patellofemoral arthroplasty.

PURPOSE: The purpose of this study was to identify effects of psychosocial and demographic factors on patellofemoral arthroplasty (PFA) outcomes. METHODS: Patients who underwent PFA by a single surgeon between 2002 and 2013 (min. 2 year follow-up) were included. Knee Society scores (KSS), UCLA, and Tegner Scores were prospectively collected in a designated arthroplasty registry. Patient records were retrospectively reviewed and univariate and multivariate statistical analyses were performed to assess the effect of psychosocial factors and demographic variables including patient sex, BMI, smoking and medication use, psychiatric history, and employment status on improvement between pre- and post-operative scores. RESULTS: Seventy-four knees in 55 patients (88% female) with a mean age of 51.8 (SD 8.8) and mean follow-up of 46.5 (SD 26.9) months were included. Patients showed significant improvement in all functional outcomes (p < 0.001). Mean improvement in KSS-F scores and median improvement in Tegner scores was greater in males compared to females (37.8 vs 16.1, p = 0.007; 3.0 vs 2.0, p = 0.07, respectively). Smokers showed less improvement in KSS-P compared to non-smokers (17.2 vs 30.0, p = 0.028). Retired or employed patients had a greater mean improvement in KSS-F and median improvement in Tegner Scores compared to those were unemployed or on work disability (p = 0.022, p = 0.01). Patients who reported using opioids and/or anti-depressants pre-operatively showed less improvement in UCLA scores (p = 0.006). Obese patients showed less improvement in both KSS-F and Tegner score compared to non-obese patients (p = 0.009, p = 0.004). CONCLUSION: Psychosocial factors influence the degree of improvement following PFA. Although patients showed overall improvement compared to their baseline scores, obese patients, smokers, unemployed/work disabled, and pre-operative use of opioids and/or anti-depressants were risk factors for decreased improvement… The consideration of psychosocial variables are clinically important when assessing a patient's candidacy for PFA and improve pre-operative patient selection and counselling. LEVEL OF EVIDENCE: Level IV.

Increasing Numbers of Shoulder Corticosteroid Injections Within a Year Preoperatively May Be Associated With a Higher Rate of Subsequent Revision Rotator Cuff Surgery.

PURPOSE: To identify any dose-dependent association between the use of subacromial corticosteroid injections within a year before rotator cuff repair (RCR) and subsequent need for revision rotator cuff surgery. METHODS: Two large administrative databases were queried for patients undergoing arthroscopic RCR. A minimum of 1 year of preoperative database exposure and 2 years of postoperative database follow-up were required for inclusion. Patients were stratified into groups that received 0 (control), 1, 2, or 3 or more ipsilateral corticosteroid shoulder injections within the year prior to RCR. The outcome of interest was ipsilateral revision arthroscopic or open RCR or arthroscopic debridement for a diagnosis of rotator cuff tear within 2 years of the index surgery. Revision rates were compared between groups using a multivariate logistic regression analysis controlling for demographic and comorbidity confounders. RESULTS: A total of 110,567 patients from the Medicare database and 12,892 patients from the private insurance database were included. There was no association between a single injection within the year prior to RCR and revision surgery in either cohort. The use of 2 or more injections was associated with a significant increase in the risk of requiring revision surgery in both the Medicare (odds ratio [OR], 2.76-3.26; P < .0001) and private insurance (OR, 2.53-2.87; P < .0001) populations. CONCLUSIONS: A single shoulder injection within a year prior to arthroscopic RCR was not associated with any increased risk of revision surgery; however, the administration of 2 or more injections was associated with a substantially increased risk of subsequent revision rotator cuff surgery (OR, 2.53-3.26). Although causality cannot be established on the basis of this database review, caution is recommended when considering more than 1 shoulder corticosteroid injection in patients with potentially repairable rotator cuff tears. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Systematic Review of Medial Patellofemoral Ligament Reconstruction Techniques: Comparison of Patellar Bone Socket and Cortical Surface Fixation Techniques.

PURPOSE: To compare patellar bone socket and cortical surface fixation techniques for isolated medial patellofemoral ligament (MPFL) reconstruction and determine whether there was a difference in (1) complication rates, including fracture of the patella; (2) redislocation rates; or (3) patient-reported outcomes. METHODS: A literature search was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We included patients who underwent isolated MPFL reconstruction for recurrent patellar instability. Patients with confirmed concomitant or prior ipsilateral knee procedures, multiligament injury, or less than 3 months of follow-up were excluded. Risk-of-bias assessment was performed using the Methodological Index for Non-randomized Studies (MINORS) system. Studies were classified by surgical technique (patellar bone socket group [group S] vs cortical fixation group [group F]), and complications, redislocations, and patient-reported outcomes were collected. RESULTS: A total of 29 studies yielded 981 patients with MPFL reconstruction for inclusion. Of the patients, 620 underwent a patellar bone socket technique and 361 underwent a cortical fixation technique. Patients ranged in age from 11 to 68 years. Patellar fracture rates ranged from 0% to 17% in group S and were 0% in all group F studies. Mean Kujala scores ranged from 83.5 to 93.6 in group S and from 84.4 to 94.5 in group F. Mean Lysholm scores ranged from 84.6 to 91.7 in group S and from 83.5 to 95 in group F. Redislocation rates ranged from 0% to 21% in group S and from 0% to 13% in group F. Although heterogeneous in nature, complication rates ranged from 0% to 28% in group S and from 0% to 4% in group F. CONCLUSIONS: MPFL reconstruction techniques with patellar bone sockets showed a larger range of complication rates than cortical fixation techniques, although overall, complications remained uncommon. Clinically, the bone socket group had comparable postoperative redislocation rates and patient outcomes to the group treated with cortical fixation techniques. LEVEL OF EVIDENCE: Level IV, systematic review of Level I through IV studies.

The lateral collateral ligament complex of the elbow: quantitative anatomic analysis of the lateral ulnar collateral, radial collateral, and annular ligaments.

BACKGROUND: Injury to the lateral ulnar collateral ligament (LUCL) complex of the elbow often results in posterolateral rotatory instability. Although surgical reconstruction of the LUCL is often required, gaps in our understanding of the LUCL complex remain. The purpose of this study was to provide a robust and accurate characterization of the lateral elbow ligamentous complex. METHODS: The LUCLs, radial collateral ligaments, and annular ligaments in 10 cadaveric elbows were 3-dimensionally digitized and reconstructed using computed tomography. Surface areas, origin and insertion footprint areas, distances between perceived footprint centers and geometric footprint centroids, distances to key landmarks, and ligament isometry were measured. RESULTS: The mean surface area of the LUCL was 229.3 mm2. The mean origin and insertion footprint areas were 26.0 mm2 and 22.9 mm2, respectively. The mean distance between the apparent centers and the geometric centroids of the footprints was 1 mm. The center of the LUCL origin was 10.7 mm distal to the lateral epicondyle and 8.2 mm from the capitellar articular margin. The center of the LUCL insertion was 3.3 mm distal to the apex of the supinator crest. The LUCL showed anisometric properties as elbow flexion increased (P < .001). CONCLUSIONS: The LUCL origin center was 10.7 mm from the lateral epicondyle, whereas the insertion center was 3.3 mm from the apex of the supinator crest. The visually estimated footprint centers were generally within 1 mm of the geometric centroid. These geometries and distances to key landmarks will be informative for surgeons seeking to perform anatomic ligament reconstruction procedures.

Incidence of posterior shoulder instability and trends in surgical reconstruction: a 22-year population-based study.

BACKGROUND: The incidence of posterior shoulder instability (PSI) in the general population is not well defined. This study aimed to define the population-based incidence of PSI and describe trends in incidence and surgery rates. METHODS: The study population included 143 patients (16 females, 127 males) diagnosed with new-onset PSI between January 1, 1994, and December 31, 2015. Medical records were reviewed to extract patient data. Age- and sex-specific incidence rates were calculated and adjusted to the 2010 United States population. Poisson regression was performed to examine trends by timeline, sex, and age. RESULTS: Age- and sex- adjusted annual incidence of PSI was 4.64 per 100,000 person-years, and posterior dislocation was 1.30 per 100,000 person-years. Peak PSI incidence for males and females was at 14 to 19 years (31.82 and 5.23 per 100,000 person-years). PSI incidence was higher in males than females (8.86 vs. 1.07 per 100,000 person-years, P < .001). The 5-year cumulative risk of surgery for patients with PSI was 53.1% between 1996 and 2002, 59.9% between 2003 and 2008, and 87.5% between 2009 and 2015. Patients with PSI between 2009 and 2015 had a significantly increased rate of surgery (hazard ratio, 2.2; 95% confidence interval, 1.4-3.6; P = .001) compared with those between 1996 and 2002. CONCLUSION: The age- and sex- adjusted incidence of PSI in the general population was 4.64 per 100,000 person-years. There is a significantly greater incidence of PSI in males than females, with both sexes peaking at 14 to 19 years and incidence rates remaining elevated throughout the third and fourth decades of life. The incidence of PSI remained stable over time; however, the rate of surgical intervention increased significantly, from 53.1% of patients between 1996 and 2002 to 87.5% of patients between 2009 and 2015.

Leveraging Technology to Improve Radiology Workflow.

Although advancements in the last decade have automated much of the radiology workflow, there are several areas in the complex imaging process where standardization and innovation can be implemented. We discuss multiple tools and integrations that can help improve operational efficiency, quality, and safety.

Arthroscopic Management of SLAP Lesions With Concomitant Spinoglenoid Notch Ganglion Cysts: A Systematic Review Comparing Repair Alone to Repair With Decompression.

PURPOSE: To determine if cyst management is necessary in the setting of SLAP lesions with concomitant paralabral ganglion cysts. METHODS: We performed a systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, including all studies that met inclusion criteria from January 1975 to July 2015. We included patients with a SLAP II-VII lesion and a concomitant paralabral ganglion cyst who underwent arthroscopic labral repair with or without cyst decompression. Patients with follow-up of less than 3 months, a SLAP I lesion, or who underwent concomitant cuff repair were excluded. The Methodological Index for Non-randomized Studies (MINORS) scoring system was used to quantify the potential bias in each study. Outcome measures reported were provided in a table format and a subjective analysis was performed. RESULTS: Nineteen studies were included yielding a total of 160 patients: 66 patients treated with repair alone [R] and 94 patients with additional cyst decompression or excision [R+D]. The VAS, Rowe, and Constant scores were excellent and similar in both groups. The mean VAS was 0.6 in [R] and ranged between 0 and 2 in [R+D] (0.5, 0, 2, 0.2). The mean Rowe scores were 94 and 98 in [R] and 95 in [R+D]. The mean Constant scores were 97 in [R] and ranged between 87 and 98 in [R+D] (98, 87, 92, 94). In total, 5 of 90 patients were unable to return to work and 2 of 45 were unable to return to sport. All 15 patients who had follow-up electromyographies displayed resolution, and in the 115 patients with follow-up MRIs, 12 did not have complete resolution of the cyst. CONCLUSIONS: Despite the lack of high-quality evidence, the studies subjectively analyzed in this review suggest that both groups have excellent results. The results do not show any advantages from performing decompression. LEVEL OF EVIDENCE: Level IV, systematic review of Level II and Level IV studies.

Contrast-enhanced or noncontrast CT for renal colic: utilizing urinalysis and patient history of urolithiasis to decide.

PURPOSE: In the emergency setting, flank pain commonly leads to a noncontrast CT despite a significant percentage of patients having alternative diagnoses, often difficult to characterize without contrast. We investigated the combined utility of urinalysis and history of urolithiasis in identifying patients who are unlikely to have urolithiasis and may benefit from a contrast-enhanced study. METHODS: Retrospective review of 350 patients from May 2013 to May 2016 was performed for patients in the emergency department with renal colic that underwent noncontrast CT and urinalysis testing. RESULTS: Urolithiasis was present in 282 of the 350 patients reviewed (81%), of which 175 (62%) had an obstructing calculus. RBC-positive urinalysis was present in 231 patients with calculi on CT (sensitivity 82%). Patient history of urolithiasis plus urinalysis had a sensitivity of 94% for detecting calculi. Thirty-five patients (10%) had alternative diagnoses, 33 of which were in patients without obstructing calculi. Sixty-seven patients underwent noncontrast CT despite no history of urolithiasis and a negative urinalysis, 10 of which (15%) had alternative diagnoses. Only three cases in this subset (4%) had nonobstructing 1-2-mm calculi, potentially missed with contrast. In this subset, the projected proportion of optimally characterized cases with intravenous contrast is 96%, compared to 85% without contrast (p = .03). DISCUSSION: Given the high combined sensitivity of urinalysis and patient history (94%), this simple analysis can confidently direct clinicians to a contrast-enhanced CT in "rule-out" cases of flank pain in patients with a negative history and negative urinalysis, particularly given that 15% of these patients had alternative diagnoses.