Periprosthetic joint infection after total hip arthroplasty induces histological degeneration of the gluteus medius tendon.

Aims: A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient's quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach. Methods: A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach. The primary variables of the study were the fibril diameter, as seen in transmission electron microscopy (TEM), and the total degeneration score (TDS), as seen under the light microscope. An analysis of bacteriology, classification of infection, and antibiotic treatment was also performed. Results: Biopsy samples from the GMED from infected patients revealed a larger fibril diameter than control patients, as seen in the TEM (p < 0.001). Uninfected patients were slightly older and had their revisions performed significantly later than the infected patients. Histologically, samples from infected patients revealed significantly more vascularity (p < 0.001), the presence of glycosaminoglycans (p < 0.001), and a higher TDS (p = 0.003) than the control patients. The majority of patients had staphylococcal infections of various species. Conclusion: More histological degeneration in the GMED was found in patients undergoing THA revision surgery due to PJI than in patients undergoing THA revision surgery due to other reasons.

Periprosthetic hip infections in a Swedish regional hospital between 2012 and 2018: is there a relationship between Cutibacterium acnes infections and uncemented prostheses?

The purpose of this study was to evaluate patients requiring in-patient care due to a periprosthetic joint infection (PJI), with respect to bacterial agents, surgical treatment, antibiotics, and outcome. We retrospectively identified all infected total hip arthroplasties (THAs) in a Swedish regional hospital during a 7-year period (2012-2018) and reviewed medical records and microbiological data. A total of 89 infected THAs in 87 patients were identified. Standardized treatment with debridement with retention of the implant and antibiotics (DAIR) was initially performed in 53 cases (60 %), one or two stage revisions in 33 cases (37 %), and an immediate Girdlestone in 3 cases (3 %). Infection eradication was seen in 77 PJIs (87 %) in addition to six patients (7 %) ending up with a permanent but uninfected Girdlestone. All six patients with manifest failures were infected with Staphylococcus aureus, two of which were also polymicrobial. Cutibacterium acnes was found in 18 of 89 patients (16 %) distributed in 15 uncemented implants but only in 3 hybrids and cemented arthroplasties, while remaining pathogens were equally distributed in uncemented THAs ( n = 31 ) and THAs with at least one cemented component ( n = 40 ; p = 0.003 ). Eradication was achieved in all 18 patients when Cutibacterium acnes was the only culture ( n = 14 ) or clearly dominant among positive cultures ( n = 4 ). DAIR was successful in selected postoperative infections up to 6 months after hip replacement. Cutibacterium acnes infections in hip arthroplasty may be underdiagnosed. Cemented components in THAs seem to protect from colonization with Cutibacterium acnes.

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

BACKGROUND: 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. 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. METHODS: One 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. RESULTS: Ultrastructurally, 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. CONCLUSIONS: The 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.

Combining a hip arthroplasty stem with trochanteric reattachment bolt and a polyaxial locking plate in the treatment of a periprosthetic fracture below a well-integrated implant.

Distally anchored uncemented modular tapered porous stems are often the preferred treatment in total hip arthroplasty revisions and failed subtrochanteric fractures. These conditions mainly affect elderly osteoporotic patients, with an increased risk of later fractures below the well-fixated implant. Treatment in secondary fractures with long looking plates is the recommended treatment, where stability is a key to fracture healing. We report a complicated case in which this was achieved by an innovative technique combing the trochanteric attachment bolt of the stem system and a locking plate with polyaxial screws.