Preoperative Magnetic Resonance Imaging Accurately Detects the Arthroscopic Comma Sign in Subscapularis Tears.

PURPOSE: To assess the accuracy and reliability of routine preoperative magnetic resonance imaging (MRI) in the detection of the comma sign compared with the gold standard of arthroscopic findings. METHODS AND MATERIALS: Preoperative MRI exams in consecutive patients undergoing arthroscopic subscapularis tendon repair, over a 5-year time frame, were retrospectively reviewed for full-thickness tears of the subscapularis and supraspinatus tendons, fatty atrophy of the subscapularis and supraspinatus muscles, and status of the long head of the biceps tendon. Each case was also evaluated for presence or absence of a comma sign on MRI. Surgical findings served as the diagnostic standard of reference in determination of a comma sign. RESULTS: The study cohort included 45 male and 10 female patients (mean age, 56; range, 32-80 years). A comma sign was present at arthroscopy in 19 patients (34.5%). Interclass and intrarater correlation showed 100% agreement in preoperative assessment of a comma sign on MRI. MRI showed an overall accuracy of 83.6% in diagnosis of a comma sign (sensitivity, 63.2%; specificity, 94.4%; positive predictive value, 85.7%; negative predictive value, 82.9%; positive likelihood ratio, 11.37; negative likelihood ratio, 0.39). No statistically significant association was observed between an arthroscopic comma sign and patient demographics or MRI findings of full-thickness rotator cuff tears, muscle fatty atrophy, or long head of the biceps tendon pathology. CONCLUSIONS: MR imaging illustrates excellent reliability and good specificity and accuracy in detection of the arthroscopic comma sign in the setting of subscapularis tendon tearing. Detection of a comma sign on MRI may be important preoperative planning information in the arthroscopic management of patients with subscapularis tendon tears. LEVEL OF EVIDENCE: Level IV, retrospective diagnostic study.

Mechanical stimulation enhances integration in an in vitro model of cartilage repair.

PURPOSE: (1) To characterize the effects of mechanical stimulation on the integration of a tissue-engineered construct in terms of histology, biochemistry and biomechanical properties; (2) to identify whether cells of the implant or host tissue were critical to implant integration; and (3) to study cells believed to be involved in lateral integration of tissue-engineered cartilage to host cartilage. We hypothesized that mechanical stimulation would enhance the integration of the repair implant with host cartilage in an in vitro integration model. METHODS: Articular cartilage was harvested from 6- to 9-month-old bovine metacarpal-phalangeal joints. Constructs composed of tissue-engineered cartilage implanted into host cartilage were placed in spinner bioreactors and maintained on a magnetic stir plate at either 0 (static control) or 90 (experimental) rotations per minute (RPM). The constructs from both the static and spinner bioreactors were harvested after either 2 or 4 weeks of culture and evaluated histologically, biochemically, biomechanically and for gene expression. RESULTS: The extent and strength of integration between tissue-engineered cartilage and native cartilage improved significantly with both time and mechanical stimulation. Integration did not occur if the implant was not viable. The presence of stimulation led to a significant increase in collagen content in the integration zone between host and implant at 2 weeks. The gene profile of cells in the integration zone differs from host cartilage demonstrating an increase in the expression of membrane type 1 matrix metalloproteinase (MT1-MMP), aggrecan and type II collagen. CONCLUSIONS: This study shows that the integration of in vitro tissue-engineered implants with host tissue improves with mechanical stimulation. The findings of this study suggests that consideration should be given to implementing early loading (mechanical stimulation) into future in vivo studies investigating the long-term viability and integration of tissue-engineered cartilage for the treatment of cartilage injuries. This could simply be done through the use of continuous passive motion (CPM) in the post-operative period or through a more complex and structured rehabilitation program with a gradual increase in forces across the joint over time.

Maximum load to failure and tensile displacement of an all-suture glenoid anchor compared with a screw-in glenoid anchor.

PURPOSE: The purpose of this study was to evaluate the biomechanical behavior of an all-suture glenoid anchor in comparison with a more conventional screw-in glenoid anchor, with regard to maximum load to failure and tensile displacement. METHODS: All mechanical testing was performed using an Instron ElectroPuls E1000 mechanical machine, with a 10 N pre-load and displacement rate of 10 mm/min. Force-displacement curves were generated, with calculation of maximum load, maximum displacement, displacement at 50 N and stiffness. Pretesting of handset Y-Knots in bone analog models revealed low force displacement below 60 N of force. Subsequently, three groups of anchors were tested for pull out strength in bovine bone and cadaver glenoid bone: a bioabsorbable screw-in anchor (Bio Mini-Revo, ConMed Linvatec), a handset all-suture anchor (Y-Knot, ConMed Linvatec) and a 60 N pre-tensioned all-suture anchor (Y-Knot). A total of 8 anchors from each group was tested in proximal tibia of bovine bone and human glenoids (age range 50-90). RESULTS: In bovine bone, the Bio Mini-Revo displayed greater maximum load to failure (206 ± 77 N) than both the handset (140 ± 51 N; P = 0.01) and the pre-tensioned Y-Knot (135 ± 46 N; P = 0.001); no significant difference was seen between the three anchor groups in glenoid bone. Compared to the screw-in anchors, the handset all-suture anchor displayed inferior fixation, early displacement and greater laxity in the bovine bone and cadaveric bone (P < 0.05). Pre-tensioning the all-suture anchor to 60 N eliminated this behavior in all bone models. CONCLUSIONS: Handset Y-Knots display low force anchor displacement, which is likely due to slippage in the pilot hole. Pre-tensioning the Y-Knot to 60 N eliminates this behavior. LEVEL OF EVIDENCE: I.

Trans-subscapularis portal versus low-anterior portal for low anchor placement on the inferior glenoid fossa: a cadaveric shoulder study with computed tomographic analysis.

PURPOSE: The purpose of this study was to evaluate the accuracy of inserting a glenoid anchor at the 5:30 clockface position using a trans-subscapularis (TSS) portal versus a low anterior (LA) portal. METHODS: Five surgeons (T.D., J.C., C.V., D.J.O-H., J.S.T.) placed a single anchor in 20 fresh-frozen cadaveric shoulders. In each of 2 shoulders, surgeons used an LA portal to insert the anchor, whereas in 2 shoulders a TSS portal was used. Surgeons were directed to place the anchor at the 5:30 position at an angle 45° to the glenoid surface (axial plane) and passing perpendicular to the glenoid rim in the coronal plane. Shoulders were then dissected and computed tomographic (CT) scans obtained. Anchor position relative to the clockface was documented by 2 blinded assessors, as was the angle of insertion in the axial and coronal planes. Statistical significance was calculated with a Student t test for paired samples (confidence interval [CI], 95%; significance, P < .05). RESULTS: The average deviation from the 5:30 position was 48 minutes (standard deviation [SD], 31 minutes) for the LA portal (average position, 4:42 o'clock) versus 28.5 minutes (SD, 19 minutes) for the TSS group (average position, 5:02 o'clock) (P = .15). The average angle of anchor insertion in the axial plane was 67.2° (SD, 19°) for the LA portal versus 62.8° (SD, 14°) for the TSS portal (P = .49), whereas the average angle of insertion in the coronal plane was 31.3° (SD, 14°) of inferior angulation in the LA group and 14.3° (SD, 8°) of inferior angulation in the TSS group (P = .009). Of the anchors inserted, 9 of 20 (45%) showed evidence of far-cortical perforation. No difference in cortical perforation was seen between the 2 portals, with perforation more likely with anchors inserted greater than 45° in the axial plane (8 of 20) than with those inserted less than 45° (1 of 20) (P = .02). CONCLUSIONS: The use of a TSS portal improves the angle of approach to the inferior glenoid rim in comparison with an LA portal, reducing the acuity of the angle of insertion in the coronal plane. CLINICAL RELEVANCE: The TSS portal is an option for surgeons performing arthroscopic Bankart repair using anchors low on the glenoid rim.

The sizing of hamstring grafts for anterior cruciate reconstruction: intra- and inter-observer reliability.

PURPOSE: The objective of this study was to establish the intra- and inter-observer reliability of hamstring graft measurement using cylindrical sizing tubes. METHODS: Hamstring tendons (gracilis and semitendinosus) were harvested from ten cadavers by a single surgeon and whip stitched together to create ten 4-strand hamstring grafts. Ten sports medicine surgeons and fellows sized each graft independently using either hollow cylindrical sizers or block sizers in 0.5-mm increments­the sizing technique used was applied consistently to each graft. Surgeons moved sequentially from graft to graft and measured each hamstring graft twice. Surgeons were asked to state the measured proximal (femoral) and distal (tibial) diameter of each graft, as well as the diameter of the tibial and femoral tunnels that they would drill if performing an anterior cruciate ligament (ACL) reconstruction using that graft. Reliability was established using intra-class correlation coefficients. RESULTS: Overall, both the inter-observer and intra-observer agreement were >0.9, demonstrating excellent reliability. The inter-observer reliability for drill sizes was also excellent (>0.9). Excellent correlation was seen between cylindrical sizing, and drill sizes (>0.9). CONCLUSIONS: Sizing of hamstring grafts by multiple surgeons demonstrated excellent intra-observer and intra-observer reliability, potentially validating clinical studies exploring ACL reconstruction outcomes by hamstring graft diameter when standard techniques are used. LEVEL OF EVIDENCE: III.

Repair of full-thickness rotator cuff tears in patients aged younger than 55 years.

PURPOSE: The purpose of this study was to conduct a systematic review of the available evidence regarding clinical outcomes after open or arthroscopic repair of full-thickness rotator cuff tears in young patients. METHODS: Medline, PubMed, and Embase were reviewed to find all studies examining full-thickness rotator cuff repairs in patients aged younger than 55 years and with a minimum of 1 year of follow-up. RESULTS: We found 7 studies that met the inclusion criteria. The mean patient age was 41.7 years (range, 16.2 to 54 years), and the mean time from injury was 66.1 months. Eighty-one percent of the included patients had a traumatic tear. The rotator cuff repair was supplemented by acromioplasty in 96.6% of patients, distal clavicle resection in 34.6%, and biceps tenodesis in 16.1%. Postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment was the most commonly reported outcome score, with a mean postoperative score of 82.0 (4 studies). Improvement was shown in all studies that reported on postoperative strength. All studies that assessed pain showed an improvement in the postoperative setting. Overall, 82% of the shoulders had satisfactory results. CONCLUSIONS: Full-thickness rotator cuff tears in patients aged younger than 55 years are mostly traumatic in origin and respond well to open and arthroscopic rotator cuff repair, as shown by good patient-reported outcomes, significant pain relief, improvement in strength, and high satisfaction postoperatively. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Supplementation with platelet-rich plasma improves the in vitro formation of tissue-engineered cartilage with enhanced mechanical properties.

PURPOSE: This study aimed to determine the effects of platelet-rich plasma (PRP) on the histologic, biochemical, and biomechanical properties of tissue-engineered cartilage. METHODS: Chondrocytes isolated from bovine metacarpal-phalangeal articular cartilage were seeded on top of a porous ceramic substrate (calcium polyphosphate [CPP]). Cultures were supplemented with fetal bovine serum (FBS), PRP, or platelet-poor plasma (PPP) at 5%. On day 5, the concentration was increased to 20%. PRP and PPP were obtained through centrifugation of whole blood withdrawn from a mature cow. After 2 weeks, samples (n = 8) were analyzed histologically, biochemically, and biomechanically. Data were analyzed using the Wilcoxon test (significance, P < .05). RESULTS: Chondrocytes cultured in 20% PRP formed thicker cartilage tissue (1.6 ± 0.2 mm) than did cells grown in 20% FBS (0.7 ± 0.008 mm; P = .002) and 20% PPP (0.8 ± 0.2 mm; P = .03). Cartilage tissue generated in the presence of 20% PRP had a greater equilibrium modulus of 38.1 ± 3.6 kPa versus 15.6 ± 1.5 kPa (P = .0002) for 20% PPP and 20.4 ± 3.5 kPa (P = .007) for 20% FBS. Glycosaminoglycan (GAG) content was increased in tissues formed in 20% PRP (176 ± 18.8 µg GAG/mg) compared with those grown in 20% FBS (112 ± 10.6 µg GAG/mg; P = .01) or 20% PPP (131.5 ± 14.8 µg GAG/mg; P = .11). Hydroxyproline content was similar whether the media was supplemented with 20% PRP (8.7 ± 0.9 µg/mg), 20% FBS (7.6 ± 0.9 µg/mg; P = .37), or 20% PPP (6.4 ± 1 µg/mg; P = .28). DNA content was similar in all tissues whether formed in 20% PRP (11.9 ± 3.5 µg/mg), 20% FBS (9.3 ± 2.5 µg/mg; P = .99), or 20% PPP (7.2 ± 1.3 µg/mg; P = .78). Immunostained samples showed prevalence of type II collagen in tissues formed in the presence of 20% PRP. CONCLUSIONS: The presence of PRP in the culture media enhances the in vitro formation of cartilage, with increased GAG content and greater compressive mechanical properties, while maintaining characteristics of hyaline phenotype. CLINICAL RELEVANCE: Understanding the in vitro effects of PRP on tissue-engineered cartilage may lead to the creation of engineered cartilage tissue with enhanced properties suitable for cartilage repair.

Correlation of preoperative MRI and MRA with arthroscopically proven articular cartilage lesions of the elbow.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of magnetic resonance imaging (MRI) in detecting elbow articular cartilage injuries through comparison of preoperative MRI and magnetic resonance arthrography (MRA) with arthroscopic findings. DESIGN: Retrospective case analysis. SETTING: Tertiary care orthopedic private practice. PATIENTS: Consecutive series of 31 patients presenting with elbow pain and diagnosed at arthroscopy with articular cartilage defects of the elbow. All patients had a preoperative MRI or MRA using a 1.5 T magnet. INTERVENTIONS: Each patient had a systematic elbow arthroscopy, with careful inspection and recording of chondral injuries in 4 anatomical regions: capitellum, radius, trochlea, and ulna. Each MRI/MRA was then independently reviewed by 2 radiologists blinded to the arthroscopic findings. MAIN OUTCOME MEASURES: The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated for MRI and MRI compared with arthroscopy as the gold standard, for each of the anatomical regions. RESULTS: The accuracy of MRI was 45% for chondral injuries of the radius, 65% for the capitellum, 20% for the ulna, and 30% for the trochlea. The accuracy of MRA was 45% for chondral injuries of the radius, 64% for the capitellum, 18% for the ulna, and 27% for the trochlea. CONCLUSION: We conclude that the ability of MRI and MRA using a 1.5 T magnet to detect articular cartilage lesions is limited. Neither MRI nor MRA demonstrates the intraarticular surface as accurately as direct visualization with the arthroscopy. This may be improved with the use of 3 T MRI. CLINICAL RELEVANCE: This study demonstrates that MRI and MRA with a 1.5 T magnet, as used in community practice, have limited ability to detect cartilage lesions of the elbow.

Characterization of Migratory Cells From Bioengineered Bovine Cartilage in a 3D Co-culture Model.

BACKGROUND: Chondrocyte migration in native cartilage is limited and has been implicated as one of the reasons for the poor integration of native implants. Through use of an in vitro integration model, it has previously been shown that cells from bioengineered cartilage can migrate into the native host cartilage during integration. Platelet-rich plasma (PRP) treatment further enhanced integration of bioengineered cartilage to native cartilage in vitro. However, it is not known how PRP treatment of the bioengineered construct promotes this. HYPOTHESIS: PRP supports cell migration from bioengineered cartilage and these migratory cells have the ability to accumulate cartilage-like matrix. STUDY DESIGN: Controlled laboratory study. METHODS: Osteochondral-like constructs were generated by culturing primary bovine chondrocytes on the top surface of a porous bone substitute biomaterial composed of calcium polyphosphate. After 1 week in culture, the constructs were submerged in PRP and placed adjacent, but 2 mm distant, to a native bovine osteochondral plug in a co-culture model for 2 weeks. Cell migration was monitored using phase-contrast imaging. Cell phenotype was determined by evaluating the gene expression of matrix metalloprotease 13 (MMP-13), Ki67, and cartilage matrix molecules using quantitative polymerase chain reaction. When tissue formed, it was assessed by histology, immunohistochemistry, and quantification of matrix content. RESULTS: PRP treatment resulted in the formation of a fiber network connecting the bioengineered cartilage and native osteochondral plug. Cells from both the bioengineered cartilage and the native osteochondral tissue migrated onto the PRP fibers and formed a tissue bridge after 2 weeks of culture. Migratory cells on the tissue bridge expressed higher levels of collagen types II and I (COL2, COL1), Ki67 and MMP-13 mRNA compared with nonmigratory cells in the bioengineered cartilage. Ki67 and MMP-13-positive cells were found on the edges of the tissue bridge. The tissue bridge accumulated COL1 and COL2 and aggrecan and contained comparable collagen and glycosaminoglycan content to the bioengineered cartilage matrix. The tissue bridge did not reliably develop in the absence of cells from the native osteochondral plug. CONCLUSION: Bioengineered cartilage formed by bovine chondrocytes contains cells that can migrate on PRP fibers and form cartilaginous tissue. CLINICAL RELEVANCE: Migratory cells from bioengineered cartilage may promote cartilage integration. Further studies are required to determine the role of migratory cells in integration in vivo.

MR imaging of the postoperative knee.

Advances in orthopedic and arthroscopic surgical procedures of the knee such as, knee replacement, ligamentous reconstruction as well as articular cartilage and meniscus repair techniques have resulted in a significant increase in the number of patients undergoing knee arthroscopy or open surgery. As a consequence postoperative MR imaging examinations increase. Comprehensive knowledge of the normal postoperative MR imaging appearances and abnormal findings in the knee associated with failure or complications of common orthopedic and arthroscopic surgical procedures currently undertaken is crucial. This article reviews the various normal and pathological postoperative MR imaging findings following anterior and posterior cruciate ligament, medial collateral ligament and posterolateral corner reconstruction, meniscus and articular cartilage surgery as well as total knee arthroplasty with emphasis on those surgical procedures which general radiologists will likely be faced in their daily clinical routine.

Integration of tissue-engineered cartilage with host cartilage: an in vitro model.

BACKGROUND: We developed a tissue-engineered biphasic cartilage bone substitute construct which has been shown to integrate with host cartilage and differs from autologous osteochondral transfer in which integration with host cartilage does not occur. QUESTIONS/PURPOSES: (1) Develop a reproducible in vitro model to study the mechanisms regulating tissue-engineered cartilage integration with host cartilage, (2) compare the integrative properties of tissue-engineered cartilage with autologous cartilage and (3) determine if chondrocytes from the in-vitro formed cartilage migrate across the integration site. METHODS: A biphasic construct was placed into host bovine osteochondral explant and cultured for up to 8 weeks (n = 6 at each time point). Autologous osteochondral implants served as controls (n = 6 at each time point). Integration was evaluated histologically, ultrastructurally, biochemically and biomechanically. Chondrocytes used to form cartilage in vitro were labeled with carboxyfluorescein diacetate which allowed evaluation of cell migration into host cartilage. RESULTS: Histologic assessment demonstrated that tissue-engineered cartilage integrated over time, unlike autologous osteochondral implant controls. Biochemically there was an increase in collagen content of the tissue-engineered implant over time but was well below that for native cartilage. Integration strength increased between 4 and 8 weeks as determined by a pushout test. Fluorescent cells were detected in the host cartilage up to 1.5 mm from the interface demonstrating chondrocyte migration. CONCLUSIONS: Tissue-engineered cartilage demonstrated improved integration over time in contrast to autologous osteochondral implants. Integration extent and strength increased with culture duration. There was chondrocyte migration from tissue-engineered cartilage to host cartilage. CLINICAL RELEVANCE: This in vitro integration model will allow study of the mechanism(s) regulating cartilage integration. Understanding this process will facilitate enhancement of cartilage repair strategies for the treatment of chondral injuries.

A systematic review of the use of platelet-rich plasma in sports medicine as a new treatment for tendon and ligament injuries.

OBJECTIVE: To evaluate, through a systematic review of the current literature, the evidence-based outcomes of the use of platelet-rich plasma (PRP) for the treatment of tendon and ligament injuries. DATA SOURCES: A search of English-language articles was performed in PubMed and EMBASE using keywords "PRP," "platelet plasma," and "platelet concentrate" combined with "tendon" and then "ligament" independently. The search was conducted through September 2010. STUDY SELECTION: Search was limited to in vivo studies. Nonhuman studies were excluded. Tissue engineering strategies, which included a combination of PRP with additional cell types (bone marrow), were also excluded. Articles with all levels of evidence were included. Thirteen of 32 retrieved articles respected the inclusion criteria. DATA EXTRACTION: The authors reviewed and tabulated data according to the year of study and journal, study type and level of evidence, patient demographics, method of PRP preparation, site of application, and outcomes. DATA SYNTHESIS: The selected studies focused on the application of PRP in the treatment of patellar and elbow tendinosis, Achilles tendon injuries, rotator cuff repair, and anterior cruciate ligament (ACL) reconstruction. Seven studies demonstrated favorable outcomes in tendinopathies in terms of improved pain and functional scores. In 3 studies on the use of PRP in ACL reconstruction, no statistically significant differences were seen with regard to clinical outcomes, tunnel widening, and graft integration. One study examined the systemic effects after the local PRP application for patellar and elbow tendinosis. CONCLUSIONS: Presently, PRP use in tendon and ligament injuries has several potential advantages, including faster recovery and, possibly, a reduction in recurrence, with no adverse reactions described. However, only 3 randomized clinical trials have been conducted.

Synthetic-echo time postprocessing technique for generating images with variable T2-weighted contrast: diagnosis of meniscal and cartilage abnormalities of the knee.

PURPOSE: To assess the feasibility and accuracy of a synthetic-echo time (TE) magnetic resonance (MR) postprocessing technique for the diagnostic evaluation of abnormalities of menisci and articular cartilage in the knee. MATERIALS AND METHODS: This study was approved by the institutional review board. Twenty-four patients (three women, 21 men; mean age, 44.8 years) gave informed written consent to prospectively undergo evaluation of their knees (10 left and 14 right knees) with standard sagittal intermediate-weighted (repetition time msec/TE msec, 2200/17) and fat-saturated T2-weighted (3600/88) fast spin-echo sequences. In addition, sagittal multiecho fast gradient-echo sequences were performed for the generation of synthetic-TE images with variable T2- or T2(*)-weighted contrast by using a newly developed synthetic-TE analysis tool that was incorporated directly into the picture archiving and communication system. Sensitivity, specificity, and accuracy values for detection of lesions in menisci and articular cartilage were calculated by using findings at surgery as reference standard. RESULTS: The standard intermediate-weighted and fat-suppressed T2-weighted MR sequences had overall sensitivity, specificity, and accuracy values of 100% and 100%, 88% and 93%, and 95% and 95% for the diagnosis of tears of medial and lateral menisci, respectively, as well as sensitivity, specificity, and accuracy values of 82%, 97%, and 95%, respectively, for articular cartilage defects. Corresponding sensitivity, specificity, and accuracy values for multiecho MR imaging with synthetic-TE MR image generation were 92% and 100%, 88% and 87%, and 90% and 90% for the diagnosis of tears of medial and lateral menisci, respectively, as well as sensitivity, specificity, and accuracy values of 70%, 99%, and 95%, respectively, for articular cartilage defects. CONCLUSION: For the evaluation of menisci and articular cartilage, images generated with the synthetic-TE technique are a potentially viable alternative to standard T2-weighted images obtained at different TEs. Furthermore, the synthetic-TE approach allowed assessment of abnormalities of menisci and articular cartilage with high sensitivity and specificity.

Magnetic resonance imaging and magnetic resonance arthrography of the shoulder: dependence on the level of training of the performing radiologist for diagnostic accuracy.

PURPOSE: Discrepancies were identified between magnetic resonance (MR) imaging and clinical findings in patients who had MR imaging examinations evaluated by community-based general radiologists. The purpose of this study was to evaluate the diagnostic performance of MR imaging examinations of the shoulder with regard to the training level of the performing radiologist. METHODS: A review of patient charts identified 238 patients (male/female, 175/63; mean age, 40.4 years) in whom 250 arthroscopies were performed and who underwent MR imaging or direct MR arthrography in either a community-based or hospital-based institution prior to surgery. All MR imaging and surgical reports were reviewed and the diagnostic performance for the detection of labral, rotator cuff, biceps, and Hill-Sachs lesions was determined. Kappa and Student's t test analyses were performed in a subset of cases in which initial community-based MR images were re-evaluated by hospital-based musculoskeletal radiologists, to determine the interobserver agreement and any differences in image interpretation. RESULTS: The diagnostic performance of community-based general radiologists was lower than that of hospital-based sub-specialized musculoskeletal radiologists. A sub-analysis of re-evaluated cases showed that musculoskeletal radiologists performed better. kappa values were 0.208, 0.396, 0.376, and 0.788 for labral, rotator cuff, biceps, and Hill-Sachs lesions (t test statistics: p = <0.001, 0.004, 0.019, and 0.235). CONCLUSIONS: Our results indicate that the diagnostic performance of MR imaging and MR arthrography of the shoulder depends on the training level of the performing radiologist, with sub-specialized musculoskeletal radiologists having a better diagnostic performance than general radiologists.

The use of GPS and inertial devices for player monitoring in team sports: A review of current and future applications.

Player-worn devices, combining global positioning system and inertial monitors, are being used increasingly by professional sports teams. Recent interest focusses on using the data generated to track trainingload and whether this may lead to more effective training prescription with better management of injury risk. The aim of this review is to summarize the development and current use of this technology alongside proposed future applications. PubMed and Medline searches (2000-2017) identified all relevant studies involving use in team sports or comparative studies with other accepted methods. Our review determined that the latest devices are valid and reliably track activity levels. This technology is both accurate and more efficient than previous methods. Furthermore, recent research has shown that measurable changes in trainingload (the acute-to-chronic load ratio) are related to injury risk. However, results remain very sport specific and generalization must be done with caution. Future uses may include injury-prevention strategies and return-to-play judgement.

Inter-surgeon variability in the identification of clock face landmarks when placing suture anchors in arthroscopic Bankart repair.

BACKGROUND: The accuracy of surgeons in utilizing the clock face method for anchor placement has never been investigated. Our hypothesis was that shoulder arthroscopy surgeons would be able to place suture anchors at predetermined positions with accuracy and reliability. METHODS: Ten cadaveric shoulders were used. Five fellowship-trained shoulder arthroscopy surgeons were directed to place a suture anchor at 3:30, 4:30, and 5:30 clock in two shoulders each. The position of the anchors was determined with computed tomography. The accuracy of placement was calculated and data analyzed with one-way analysis of variance. The intraclass correlation coefficients were calculated. RESULTS: The overall accuracy was 57%. The accuracy of anchor placement at the 3:30 position was 40% (average position 2:24 o'clock), it was 50% at the 4:30 position (average position 3:42 o'clock) and 80% at the 5:30 position (average position 5:03 o'clock). No statistical difference in accuracy between the placement of the superior, middle, and inferior anchors (p = 0.145) was seen. The intraclass correlation coefficient for inter-surgeon reliability was 0.4 (fair) while the intraclass correlation coefficient for intra-surgeon reliability was 0.6 (moderate). DISCUSSION: The findings of this study suggest a moderate degree of accuracy and fair to moderate inter- and intra-surgeon reliability when using the clock face system to guide anchor placement.

Short term clinical outcome of a porous tantalum implant for the treatment of advanced osteonecrosis of the femoral head.

PURPOSE OF THE STUDY: Osteonecrosis of the hip mostly affects young individuals and often progresses to a debilitating disease. Several treatment modalities exist, but none are completely satisfactory. This study evaluates the clinical outcome of patients treated with core decompression and insertion of a porous tantalum implant in the femoral head. This procedure is similar to commonly performed procedures, but has the additional advantages of providing structural support to the necrotic femoral head while having no donor-site morbidity. METHODS: We evaluated 15 patients with 18 osteonecrotic hips with Steinberg stage III (3 hips) and IV (15 hips) disease. The mean age of the patients was 42 years-old (eldest 66), and the mean time for follow-up was 23 months. The outcome measure was hip function, evaluated with the Harris hip score, and the end point was total hip arthroplasty, or referral for this procedure. RESULTS: The success rate at twelve months postoperatively was 77.8%, and the overall success rate was 44.5%. Failures occurred at a mean time of 11.7 months, and one complication, a periprosthetic fracture, occurred 4 months postoperatively. On average, patients who did well improved their Harris hip scores by 21.7 points, and patients who eventually required arthroplasty decreased their scores by 14 points. CONCLUSIONS: Core decompression with porous tantalum implants showed encouraging success rates and early clinical results in patients with advanced stage osteonecrosis, but further larger scale studies are required to identify the population best suited for this procedure.

A Qualitative Investigation of Return to Sport After Arthroscopic Bankart Repair: Beyond Stability.

BACKGROUND: Arthroscopic shoulder stabilization is known to have excellent functional results, but many patients do not return to their preinjury level of sport, with return to play rates reported between 48% and 100% despite good outcome scores. PURPOSE: To understand specific subjective psychosocial factors influencing a patient's decision to return to sport after arthroscopic shoulder stabilization. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Semistructured qualitative interviews were conducted with patients aged 18 to 40 years who had undergone primary arthroscopic shoulder stabilization and had a minimum 2-year follow-up. All patients participated in sport before surgery without any further revision operations or shoulder injuries. Qualitative data analysis was performed in accordance with the Strauss and Corbin theory to derive codes, categories, and themes. Preinjury and current sport participation was defined by type, level of competition, and the Brophy/Marx shoulder activity score. Patient-reported pain and shoulder function were also obtained. RESULTS: A total of 25 patients were interviewed, revealing that fear of reinjury, shifts in priority, mood, social support, and self-motivation were found to greatly influence the decision to return to sport both in patients who had and had not returned to their preinjury level of play. Patients also described fear of sporting incompetence, self-awareness issues, recommendations from physical therapists, and degree of confidence as less common considerations affecting their return to sport. CONCLUSION: In spite of excellent functional outcomes, extrinsic and intrinsic factors such as competing interests, kinesiophobia, age, and internal stressors and motivators can have a major effect on a patient's decision to return to sport after arthroscopic shoulder stabilization. The qualitative methods used in this study provide a unique patient-derived perspective into postoperative recovery and highlight the necessity to recognize and address subjective and psychosocial factors rather than objective functional outcome scores alone as contributing to a patient's decision to return to play.

Neurological Complications Related to Elective Orthopedic Surgery: Part 1: Common Shoulder and Elbow Procedures.

Many anesthesiologists are unfamiliar with the rate of surgical neurological complications of the shoulder and elbow procedures for which they provide local anesthetic-based anesthesia and/or analgesia. Part 1 of this narrative review series on neurological complications of elective orthopedic surgery describes the mechanisms and likelihood of peripheral nerve injury associated with some of the most common shoulder and elbow procedures, including open and arthroscopic shoulder procedures, elbow arthroscopy, and total shoulder and elbow replacement. Despite the many articles available, the overall number of studied patients is relatively low. Large prospective trials are required to establish the true incidence of neurological complications following elective shoulder and elbow surgery. WHAT'S NEW: As the popularity of regional anesthesia increases with the development of ultrasound guidance, anesthesiologists should have a thoughtful understanding of the nerves at risk of surgical injury during elective shoulder and elbow procedures.