Reverse shoulder arthroplasty glenoid fixation: is there a benefit in using four instead of two screws?

BACKGROUND: To allow osseous integration to occur and thus provide long-term stability, initial glenoid baseplate fixation must be sufficiently rigid. A major contributing factor to initial rigid fixation is baseplate screw fixation. Current baseplate designs use a 4-screw fixation construct. However, recent literature suggests adequate fixation can be achieved with fewer than 4 screws. The purpose of the present study was to determine whether a 4-screw construct provides more baseplate stability than a 2-screw construct. METHODS: A flat-backed glenoid baseplate with 4 screw hole options was implanted into 6 matched pairs of cadaver scapulas using standard surgical technique. Within each pair, 2 screws or 4 screws were implanted in a randomized fashion. A glenosphere was attached allowing cyclic loading in an inferior-to-superior direction and in an anterior-to-posterior direction. Baseplate motion was measured using 4 linear voltage displacement transducers evenly spaced around the glenosphere. RESULTS: There was no statistical difference in the average peak central displacements between fixation with 2 or 4 screws (P = .338). Statistical increases in average peak central displacement with increasing load (P < .001) and with repetitive loading (P < .002) were found. CONCLUSION: This study demonstrates no statistical difference in baseplate motion between 2-screw and 4-screw constructs. Therefore, using fewer screws could potentially lead to a reduction in operative time, cost, and risk, with no significant negative effect on overall implant baseplate motion.

Trends of snowboarding-related fractures that presented to emergency departments in the United States, 2010 to 2016.

BACKGROUND: Since it was introduced as an Olympic sport in 1998, snowboarding has drawn the participation of individuals of all ages. Despite the growing popularity of this sport, individuals can suffer from a number of musculoskeletal injuries. The specific goals of the study were to: (I) compare the number of injuries and trends of snowboarding injuries; (II) identify the injury occurrences, trends, and incidence of snowboarding-related fractures; and (III) identify the injury occurrences and trends of snowboarding-related fractures by body part. METHODS: The National Electronic Injury Surveillance System (NEISS) database was queried for snowboarding injuries and snowboarding-related fractures treated in US emergency departments (EDs) from 2010-2016. The weighted estimate of the number of injuries were obtained by using the NEISS statistical weight calculations that were provided in the data. An estimated total of 248,388 patients (mean age =20 years) experienced a snowboarding-related injury. Linear regression analysis was used to analyze annual trends of snowboarding-related fractures and the snowboarding-related fractures by body part; reported as the correlation coefficient (r) and the coefficient of determination (R2). RESULTS: The estimated annual number of injuries decreased from 56,223 injuries in 2010 to 17,667 injuries in 2016 (r=-0.967, R2=0.936, P<0.001). The most common types of injuries were fractures (31.7%), strains/sprains (25.2%), contusions (10.9%), concussions (10.0%), internal injuries (7.2%), and dislocations (4.0%). From 2010 to 2016, the estimated annual number of fractures decreased from 18,757 in 2010 to 4,539 in 2016 (r=-0.978, R2=0.957, P<0.001), and the annual incidence of snowboarding-related fractures decreased by 23.1%. The most common location of snowboarding-related fractures was the upper extremity, more specifically the wrist (32.3%). There was a decrease in the estimated annual number of fractures of the wrist (r=-0.965, R2=0.932, P<0.001), forearm (r=-0.821, R2=0.861, P=0.023), shoulder (r=-0.872, R2=0.760, P=0.011), elbow (r=-0.901, R2=0.813, P=0.006), and lower leg (r=-0.929, R2=0.864, P=0.002). CONCLUSIONS: With the growing popularity of snowboarding in the US, it is important to know the common types of injuries that occur. This study found that fractures were the most common injuries, especially of the upper extremity.

Knee dislocation with popliteal artery disruption: A nationwide analysis from 2005 to 2013.

OBJECTIVE: Few have compared short-term outcomes following knee dislocations with or without concomitant popliteal artery disruption (PAD). METHODS: The Nationwide Inpatient Sample was used to identify 2175 patients admitted for knee dislocation from 2005 to 2013 (concomitant PAD: n = 210/9.7%; without: n = 1965/90.3%). RESULTS: Patients with PAD were younger, more often male, Black and Hispanic, and with Medicaid (all p ≤ 0.013). PADs were associated with 11.0-times higher odds of increased LOS (95%CI, 6.6-18.4) and 2.8-times higher odds of experiencing any complication (95%CI, 2.03-3.92). Female sex was a protective factor against increased LOS, (OR = 0.65; 95%CI, 0.48-0.88). CONCLUSION: High suspicion index should be maintained for concomitant vascular injuries following knee dislocations.

Epidemiology and Trends of Weightlifting-Related Sprains and Strains that Presented to Emergency Departments in the United States.

Despite potential health benefits of weightlifting and physical activity, individuals can suffer from a number of musculoskeletal injuries. This study aimed to: (i) compare incidence and annual trends of different weightlifting injury types presenting to emergency departments in the United States and (ii) identify frequency and annual trends of weightlifting-related sprains and strains to each body part. The National Electronic Injury Surveillance System was queried to identify all weightlifting-related injuries from 2010-2016. Incidence and annual trends of various types of weightlifting-related injuries were compared during the study period. Furthermore, frequency and annual trends of weightlifting-related sprains and strains to different body parts were assessed. The weighted estimated annual incidence of weightlifting-related injuries significantly increased from 86,910 in 2010 to 109,961 in 2016 (R2 = 3.382; p = 0.01). The most common weightlifting-related sprains and strains involved the lower trunk (29.4%), shoulder (22.6%), upper trunk (17.3%), neck (6.5%), upper arm (5.6%), wrist (4.8%), knee (3.4%), and elbow (2.6%). There was a significant increase in the frequency and trends of sprains and strains that involved the lower trunk (R2 = 0.631; p = 0.033). Weightlifting-related injuries have increased, of which sprains and strains were the most common. Additionally, the most commonly affected body part was the lower trunk. Further studies are needed to determine the etiologies of weightlifting-related lower trunk sprains/strains. This study may be beneficial to weightlifters, highlighting common injury types, thereby allowing them to take preventative measures.