Influence of Aging on Microvascular Supply of the Gluteus Medius Tendon: A Cadaveric and Histologic Study.

PURPOSE: The purpose of this cadaveric study was to assess the relation between age and microvascular supply of 3 areas of the gluteus medius tendon using a previously validated CD31 immunohistochemistry staining technique. METHODS: Twenty-four fresh-frozen gluteus medius specimens were obtained through a posterolateral approach to the hip. Specimens aged 18 years or older, of either sex, and of any race were considered for this study. The average age of donors was 47.3 years (range, 18-68 years). Each sample was divided into 3 portions: musculotendinous, tendinous, and tendon-bone junction. H&E staining was used for qualitative structural analysis, and then all samples underwent staining with CD31 immunohistochemistry for quantitative assessment of vessels per square millimeter. A comparison of the microvessel density between zones according to age was performed by an analysis of variance. To evaluate the relation between microvessel supply and age, a regression model with curvilinear estimation was used. The data were fitted to a quadratic model. RESULTS: Vascular supply in transversal and longitudinal cuts regardless of the zone was, on average, 53.9 ± 32.1 vessels/mm2 and 51.1 ± 19.3 vessels/mm2, respectively. All the areas of the tendon showed a strength of relation (R) ranging from 0.41 to 0.76 between age and vascular supply. In addition, the proportion of vascular supply change explained by age (R2) was significant in most cases (ranging from 0.17 to 0.56, with P < .05). CONCLUSIONS: There is a chronological relation between aging and microvascular supply of the gluteus medius tendon, in which an initial increase occurs from 18 years of age to 30 to 40 years of age, with a progressive decrease after 50 years of age. CLINICAL RELEVANCE: The findings of our study may have implications for increased vulnerability of the gluteus medius tendon and decreased healing potential.

Iliopsoas tendon insertion footprint with surgical implications in lesser trochanterplasty for treating ischiofemoral impingement: an anatomic study.

The objective of this study was to describe the footprint location of the iliopsoas tendon on the lesser trochanter to clarify the surgical implications of the lesser trochanterplasty for treating ischiofemoral impingement. Ten non-matched, fresh-frozen, cadaveric hemipelvis specimens (average age, 62.4 years; range, 48-84 years; 7 male and 3 female) were included. Registered measures included bony parameters of the lesser trochanter (lesser trochanteric area, distances from the tip to the base in a coordinate system, height and area) and tendinous iliopsoas footprint descriptions (areas and detailed location). The mean height of the lesser trochanter was 13.1 (SD ± 1.8) mm, with female having a smaller lesser trochanter on average (11.3, SD ± 2.0). A double tendinous footprint was found in 7 (70%) specimens. The average area of the single- and double-footprint was 211.2 mm(2) and 187.9 mm(2), respectively. An anterior cortical area with no tendinous insertion on the anterior aspect of lesser trochanter was present in all specimens and measured 4.9 mm (SD ± 0.6) on average. The mean ratio between the bald anterior wall and the lesser trochanter height was 38% (SD ± 0.05). The iliopsoas tendon footprint is double (psoas and iliacus) in most cases and is located on the anteromedial tip of the lesser trochanter. A bald anterior wall on the bottom of the lesser trochanter indicates that a partial or total lesser trochanterplasty for increasing the ischiofemoral space without detaching partially or entirely the iliopsoas tendon is improbable.