Sarcomatous change in the Pagetoid tibiae

Cure rate of infections is not an argument for spacer in two-stage revision arthroplasty of the hip

INTRODUCTION

 A devastating complication after total hip arthroplasty (THA) is chronic periprosthetic joint infection (PJI). Most frequently spacers (Sp) with or without antibiotics are implanted in a two-stage procedure even though not always indicated due to unknown pathogen, femoral and acetabular defects or muscular insufficiency.

MATERIALS AND METHODS

 A retrospective analysis of a prospectively collected database was conducted, analyzing the treatment of 44 consecutive cases with chronic PJI undergoing two-stage revision using a Girdlestone situation (GS) in the interim period between 01/2015 and 12/2018. Diagnostics included intraoperative microbiological cultures, histological analysis, sonication of the initial implant, analysis of hip aspiration, as well as laboratory diagnostics and blood cultures. We analyzed the general and age-group-specific success rate of treatment using GS. Furthermore, we compared our data with the current literature on spacer implantation regarding common complications.

RESULTS

In total, 21 female and 23 male patients at a mean age of 59.3 ± 9.6 years were included. Age groups were divided into young, mid-age, and elderly. In most patients, microbiology revealed Staphylococcus epidermidis in 39.1% of cases, following Staphylococcus lugdunensis and Staphylococcus aureus in 10.9% after THA explantation. For histology, Krenn and Morawietz type 2 (infectious type) was diagnosed in 40.9%, type 3 (infectious and abrade-induced type) in 25.0%. With GS, the total cure rate was 84.1% compared to 90.1% (range 61-100%) using Sp as described in the literature. Among age-groups, cure rate varied between 77.8 and 100%. Other complications, which only occurred in the mid-age and elderly group, included the necessity of transfusion in 31.1%, and in total, one periprosthetic fracture was identified (2.3%).

CONCLUSION

GS shows an acceptable cure rate at a minimum of 2 years when compared to the cure rate reported in the literature for Sp without major complications. For patients with increased risks for treatment failure using spacer, GS seems to be an alternative for chronic PJI when looking at the success rate of treatment.

LEVEL OF EVIDENCE

III, Retrospective trial.

Current options for the treatment of Paget's disease of the bone

Paget’s disease of bone (PDB) is a chronic bone remodelling disorder characterized by increased osteoclast-mediated bone resorption, with subsequent compensatory increases in new bone formation, resulting in a disorganized mosaic of woven and lamellar bone at affected skeletal sites. This disease is most often asymptomatic but can be associated with bone pain or deformity, fractures, secondary arthritis, neurological complications, deafness, contributing to substantial morbidity and reduced quality of life. Neoplastic degeneration of pagetic bone is a relatively rare event, occurring with an incidence of less than 1%, but has a grave prognosis. Specific therapy for PDB is aimed at decreasing the abnormal bone turnover and bisphosphonates are currently considered the treatment of choice. These treatments are associated with a reduction in plasma alkaline phosphatase (ALP) activity and an improvement in radiological and scintigraphic appearance and with a reduction in bone pain and bone deformity, Recently, the availability of newer, more potent nitrogen-containing bisphosphonates has improved treatment outcomes, allowing a more effective and convenient management of this debilitating disorder.

Pathogenesis and management of Paget's disease of bone

Paget's disease of bone is a common disease characterised by focal areas of increased bone turnover, affecting one or several bones throughout the skeleton. Paget's disease is often asymptomatic but can be associated with bone pain and other complications such as osteoarthritis, pathological fracture, bone deformity, deafness, and nerve compression syndromes. Genetic factors have an important role in this disease, and mutations have been identified in four genes that cause Paget's disease and related syndromes. The most important of these is Sequestosome 1 (SQSTM1), which is a scaffold protein in the nuclear factor kappaB (NFkappaB) signalling pathway. Patients with SQSTM1 mutations have severe Paget's disease of bone and a high degree of penetrance with increasing age. Environmental factors also contribute. Most research has focused on paramyxovirus infection as a possible trigger, but evidence for this notion is conflicting. Other potential triggers include deficiency of dietary calcium and repetitive mechanical loading of the skeleton. Medical management of Paget's disease of bone is based on giving inhibitors of osteoclastic bone resorption, and bisphosphonates are the treatment of first choice. Bisphosphonate therapy is primarily indicated for patients who have bone pain arising from increased metabolic activity in affected bones. Bisphosphonate therapy is highly effective at reducing bone turnover, and it has been shown to heal radiological lesions and restore normal histology; however, the long-term effects of bisphosphonates on disease progression have not been adequately studied. No firm evidence as yet exists to show that bisphosphonates can prevent the development of complications of Paget's disease of bone, and further work is needed to address the effects of treatment on long-term clinical outcome.