Thickness of the Rotator Cuff Tendons at the Articular Margin: An Anatomic Cadaveric Study.

BACKGROUND: With a substantial portion of the population experiencing rotator cuff pathology, the importance of understanding mechanisms of rotator cuff disease remains critical. Current research aimed at understanding relationships between shoulder movement and cuff injuries has been hindered by our limited knowledge of the thickness of soft tissue structures within the shoulder. Therefore, the purpose of this study is to measure the thicknesses of all four rotator cuff tendons at the articular margin. METHODS: An anatomic study of 21 cadaveric shoulders was conducted. The thicknesses of the four rotator cuff tendon insertions were measured by caliper at the articular margin. RESULTS: The mean thickness of the supraspinatus at the articular margin was 4.9 mm ± 2.1 (median: 4.2 mm, range: 2.9-12.7 mm). The mean thickness of the infraspinatus tendon was 4.9 mm ± 1.3 (median: 4.8 mm, range: 3.0-7.2 mm). The mean thickness of the teres minor tendon was 3.20 mm ± 1.14 (median: 2.9 mm, range: 1.7-5.7 mm). Finally, the mean thickness of the subscapularis tendon at the articular margin was 5.5 mm ± 1.3 (median: 5.5 mm, range: 3.5-9.3 mm). CONCLUSIONS: This current study provides needed objective data about the thickness of the rotator cuff tendons at the articular margin. Data regarding the infraspinatus, teres minor and teres major, which have been largely understudied, are particularly important. In addition, the current study demonstrates that rotator cuff thicknesses can vary substantially between individuals. There are likely natural age related changes as well as changes from etiologies that are not yet elucidated. Clinical Relevance: Data from this study will allow for improved modelling accuracy of soft tissue structures specific to the shoulder. Eventually knowledge gained through study of shoulder mechanics can be used to pursue prevention of rotator cuff tears and improve targeted treatment planning.

Anterior Cruciate Ligament Injuries in Professional Hockey Players.

BACKGROUND: Performance outcomes and return-to-play data have been reported after anterior cruciate ligament (ACL) injuries in professional football and basketball, but they have rarely been reported in professional hockey. HYPOTHESIS: The hypothesis was that performance after ACL reconstruction would be comparable to prior levels of play in a series of National Hockey League (NHL) players. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The NHL Injury Surveillance System (ISS) was utilized to identify all players with an ACL injury between 2006 and 2010. Medical staff members for all NHL teams were surveyed regarding these injuries. The medical staff completed a questionnaire for each injury, and statistics were analyzed using multiple analyses of variance to compare outcomes, performance, and the complication rate. A control group was identified and matched based on performance, career length before injury, age, height, and weight. RESULTS: There were 47 players identified by the NHL ISS. There were 3 goalies, 8 defensemen, and 36 wings or centers. The average age of these players was 27.69 years. The average length of time played after the injury was 2.8 years, which was less than that of the control group (4.4 years) (P = .004). The presence of a meniscal injury was associated with a decreased length of career compared with the control group (P = .012) and with patients with an isolated ACL injury (P = .002). For wings and centers, the number of games played decreased from 71.2 to 58.2 in the first full season after the injury (P = .05) and to 59.29 in the second season (P = .03). In the first season after the injury, for forwards and wings, assists and total points decreased from 20.3 and 35.2 to 13.8 (P = .005) and 25.9 (P = .018), respectively. In the second season after the injury, assists and goals decreased to 10.0 (P = .002) and 10.0 (P = .013), respectively. Compared with controls, the per-season averages of goals (P = .001), assists (P = .010), and total points (P = .004) decreased. Four players (8.5%) had subsequent failure of reconstruction, and there was a total reoperation rate of 20%. Five players (10.6%) did not return to play, and 4 (8.5%) were unable to return to play for a full season. CONCLUSION: Most players are able to return to play in the NHL after an ACL injury. However, career length and performance may be significantly decreased compared with controls. This may represent a more severe initial injury, and more focused return-to-play pathways may identify barriers to return to play.

Changes in involved and uninvolved limb function during rehabilitation after anterior cruciate ligament reconstruction: implications for Limb Symmetry Index measures.

BACKGROUND: Functional testing is used to assess anterior cruciate ligament (ACL) reconstruction rehabilitation, with the goal of symmetric ability. The pattern of change in the uninvolved limb's function during rehabilitation is not established. HYPOTHESES: (1) Involved and uninvolved limb ability increases during rehabilitation, but the uninvolved limb ability increases to a lesser degree. (2) Hop tests will show larger initial asymmetry and will improve the most with rehabilitation. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a retrospective case series of 122 patients who underwent ACL reconstruction at our ambulatory surgery center and received multiple postoperative Standard Functional Tests (SFTs) between October 2009 and October 2013. Ten of the 12 individual tests within the SFT battery were analyzed. The patients' earliest and latest SFTs were compared for changes in Limb Symmetry Index (LSI) and absolute function in each limb. We also analyzed the subgroup with SFTs (n = 38) at both 4 and 6 months postoperatively. RESULTS: In all patients with multiple SFTs, involved limb performance increased in all tests except eyes-closed stork. Uninvolved limb performance increased in 4 SFT component tests and decreased in none. LSI significantly improved in 6 tests, all of which also showed involved limb improvement that was significant. Of these 6 tests, 5 showed initial LSI below 90%: single-leg squat, retro step-up, single-leg hop, crossover triple hop, and timed hop. Retro step-up and single-leg hop showed LSI improvements greater than 10 percentage points. In patients with 4- and 6-month data, involved limb performance increased in all tests except single-leg triple hop. Uninvolved limb performance increased in 5 SFT component tests and decreased in none. LSI significantly improved in 4 tests, all of which had initial LSI below 90%, and showed involved limb improvement that was significant. Retro step-up, single-leg hop, and crossover triple hop showed LSI improvements greater than 10 percentage points. CONCLUSION: During ACL reconstruction rehabilitation, LSI improvements indicated absolute increases in involved limb ability and were not attributable to uninvolved limb deterioration. The single-leg squat, retro step-up, single-leg hop, crossover triple hop, and timed hop are suggested as highly useful tests, since all showed initial LSI below 90%, with significant LSI improvement after rehabilitation.