Comparison of the Amount of Iliopsoas Tendon Lengthening That Occurs after ArthroscopicLabral-Level and Lesser Trochanteric Tenotomies

OBJECTIVES: The success of arthroscopic iliopsoas tenotomies (AIT’s) performed at the level of the lesser trochanter for treatment of a painful snapping tendon is well documented. Currently, iliopsoas labral-level tenotomies have been advocated for treatment of this problem. However, a recent study reported a high incidence (∼50%) of recurrent snapping after iliopsoas tendon (IT) releases at this level (1). The purpose of this study was to determine if there is a difference in the amount of tendon separation/lengthening following AIT’s at the labral and lesser trochanteric levels. To date, the amount of tendon separation that occurs after releases at these two sites has not been reported. METHODS: From the senior author’s data base of 900 hip arthroscopies, 80 patients who had arthroscopic iliopsoas tenotomies performed:1) at the level of the labrum (40 patients); or 2) at the lesse rtrochanter (40 patients) were identified. The amount of tendon separation/lengthening in these 80 patients was determined either from direct intra-operative measurements (40 patients) or from measurements made off of the intra-operative photographs. Image magnification on the intra-operative photographs was controlled for by basing the measurements of tendon separation on the known dimensions of the radiofrequency probe or 5 mm cannula that was present in each iliopsoas release picture (Figure 1). Two sample t tests were used for data analysis with p = <0.05 defined as significant. RESULTS: Average age of the 40 patients with labral-level (LL) tenotomies was 36 years (range 16-58 years), and there were 9 males and 31 females and 19 left and 21 right hips in this group. Average age of the 40 patients with lesser trochanteric (LT) tenotomies was 32 years (range 17-55 years), and there were 8 males and 32 females, and 11 left and 29 right hips in this group. In the LL tenotomy group, the average tendon separation was 8.3 ± 2.04 mm. In the LT tenotomy group, the average tendon separation was 13.3 ± 3.01 mm. The 0.5 cm difference in the amount of tendon separation between the two groups was statistically significant at the p<0.001 level. CONCLUSION: An arthroscopic, lesser trochanteric iliopsoas tenotomy produces significantly greater (0.5 cm) tendon separation than tenotomies performed at the level of the labrum. The difference in the amount of tendon separation that occurs at these two sites may explain the high rates of recurrent snapping (∼50%) that have been reported with arthroscopic and open labral-level releases.