Purpose

Transfusion rates after primary total hip has been reported up to 39.2%. The purpose of our study was to evaluate the efficacy of TXA in minimizing risk of allogeneic blood transfusion after primary total hip and hip resurfacing arthroplasty.

Purpose: The upward migration index (UMI) is a useful radiographic parameter for assessment of disorders of the rotator cuff. Utility of the UMI as a prognostic indicator for outcome following cuff repair has not been previously studied. The objective of this study was to determine if an association exists between the pre-operative UMI and the improvement in clinical and quality of life outcome scores following arthroscopic rotator cuff repair.

Method: Patients with a full thickness tear of the rotator cuff who underwent an arthroscopic repair of the cuff were selected for review. Eighty-four patients were included in the series. Mean patient age was 55 (range 25–78). The UMI was measured by MRI, and patients were divided into three groups: < 1.25 (GROUP A), 1.25–1.35 (GROUP B) and > 1.35 (GROUP C). Outcome variables were the non-weighted Constant-Murley score, ASES and the WORC assessed at baseline, 6 month and 12 months post-operatively. The paired t-test was used to carry out comparisons in follow up and one-way ANOVA was used to carry out comparisons between groups.

Results: There were 9 patients in group A, 33 in group B and 42 in group C. The improvement in scores from baseline to 1 year were as follows: ASES; 21.1 (A), 32.6 (B), and 38.4 (C); Constant 21.4 (A) 19.8 (B), and 24.2 (C) and WORC 31.9 (A), 42.7 (B), and 44 (C). Statistically significant improvements were observed in all groups in all outcome measures from baseline to 6 months and from 6 months to 1 year. Although the differences were not statistically significant (p> 0.05), a trend toward greater improvement in outcomes was observed with higher upward migration indices.

Conclusion: A lower UMI was associated with less improvement in functional and quality of life outcomes following arthroscopic rotator cuff repair, although these differences were not statistically significant. Patients with a low UMI demonstrated a significant improvement in functional and quality of life scores following surgery. In isolation, a low UMI should not represent a significant contraindication to treatment by arthroscopic rotator cuff repair.

Purpose: The mechanical behavior of human scapholunate ligaments is not described well in the literature regarding torsion. Presently, intact scapholunate specimens were mechanically tested in torsion to determine if any tensile forces were generated as a result.

Method: Scapholunate specimens (n=19) were harvested and inspected visually. Scaphoid and lunate bones were potted in square chambers using epoxy cement. The interposing ligaments remained exposed. Specimens were mounted in a specially designed test jig and remained at a fixed axial length during testing. Using angular displacement control, ligaments were subjected to a torsional motion regime that included cyclic preconditioning (25 cycles, 1 Hz, triangular wave, 5 deg max), ramp-up to 15 deg at 180 deg/min, stress relaxation for 120 sec duration, ramp-down to 0 angulation at 180 deg/min, rest period for 5–10 minutes, and torsion-to-failure at 180 deg/min. Torque and axial tension were monitored simultaneously.

Results: Tests showed a coupled linear relationship between applied torsion and the resultant tensile forces generated for the ligament during ramp-up (Torsion/Tension Ratio = 38.86 +/− 29.00 mm, Linearity Coefficient R-squared = 0.89 +/− 0.15, n=19), stress relaxation (Ratio = 23.43 +/− 15.84 mm, R-squared = 0.90 +/− 0.09, n=16), and failure tests (Ratio = 38.81 +/− 26.39 mm, R-squared = 0.77 +/− 0.20, n=16). No statistically significant differences were detected between the Torsion/Tension ratios (p=0.13) or between the linearity (R-squared) of the best-fit lines (p> 0.085).

Conclusion: A strong linear relationship between applied torsion and resulting tensile forces for the ligament was exhibited during all testing phases. This may suggest that there is interplay between torsion and tension in both the stabilization of the scapholunate ligament during normal physiological motion and during resistance to injury processes. This is the first report in the literature of the coupling of torsion with tension for the scapholunate ligament.