Histological and ultrastructural degenerative findings in the gluteus medius tendon after hip arthroplasty

Mustafa Ibrahim,Ninni Sernert,Urban Hedlundh,Tomas Movin,Lars Haag,Jüri-Toomas Kartus,Khaled Meknas,Nikos Papadogiannakis

doi:10.1186/s13018-021-02434-1

Abstract

BackgroundDespite gluteus medius (GMED) tendinosis being relatively common, its presence in association with hip osteoarthritis (OA) or total hip arthroplasty (THA) is not well studied. It was hypothesized that more tendon degeneration would be found in patients with OA of the hip and in those that had undergone THA than that in a control group.MethodsOne hundred patients were included between 2016 and 2019 and were included into 4 groups; the patients were undergoing revision surgery in two groups and primary THA in the other two groups; 22 patients had previously undergone primary THA through a direct lateral approach (involving sectioning of the GMED tendon), 24 patients had previously undergone primary THA through a posterior approach (leaving the GMED tendon intact), 29 patients had primary hip OA, and 25 patients who suffered a femoral neck fracture served as controls. Biopsies from the GMED tendon were obtained at the time of the primary THA or the hip revision surgery. The tendon biopsies were examined ultrastructurally and histologically.ResultsUltrastructurally, the direct lateral and posterior revision groups had statistically significantly more collagen fibrils with smaller diameters compared with the fracture and primary THA groups. Moreover, the direct lateral revision group had more collagen fibrils with smaller diameters compared with the posterior revision group.Histologically, the direct lateral revision group had a higher total degeneration score (TDS) compared with the primary hip OA group.ConclusionsThe GMED tendon shows more ultrastructural degeneration in patients who undergo hip revision arthroplasty than in patients with primary OA of the hip and control patients, who had suffered a femoral neck fracture. Furthermore, patients who had previously undergone primary THA through a direct lateral approach revealed more histological GMED tendon degeneration than patients who suffer primary hip OA.

Highlights

Despite gluteus medius (GMED) tendinosis being relatively common, its presence in association with hip osteoarthritis (OA) or total hip arthroplasty (THA) is not well studied
These patients were included in one of four groups; the direct lateral revision group included patients who were scheduled for hip revision arthroplasty and had previously undergone primary THA through a direct lateral approach; the posterior revision group included patients who were scheduled for hip revision arthroplasty and had previously undergone primary THA through a posterior approach; the primary OA group included patients who were scheduled for primary THA due to OA of the hip, and lastly, the fracture group included patients who were scheduled for primary THA due to femoral neck fracture (Table 1)
The direct lateral revision group had a statistically significantly smaller mean fibril diameter compared with the posterior revision group (p < 0.0001) (Table 3, Figs. 1 and 2a–d)

Summary

Introduction

Despite gluteus medius (GMED) tendinosis being relatively common, its presence in association with hip osteoarthritis (OA) or total hip arthroplasty (THA) is not well studied. Even if the beneficial effects of total hip arthroplasty (THA) for treatment of osteoarthritis (OA) have been documented, more than one in ten patients are not entirely satisfied [1]. Limping is associated with abductor muscle insufficiency, a symptom of OA, and a pronounced dissatisfaction outcome measure after hip arthroplasty. The two most commonly used approaches have been the direct lateral and the posterior [3]. The GMED tendon is spared in the posterior approach. This approach has been shown to involve an increased risk of postoperative dislocations [5,6,7]

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