Osteonecrosis and fractures following renal transplantation

Various musculoskeletal manifestations of chronic renal insufficiency

Musculoskeletal manifestations in chronic renal insufficiency are caused by complex bone metabolism alterations, now described under the umbrella term of chronic kidney disease mineral- and bone-related disorder (CKD-MBD), as well as iatrogenic processes related to renal replacement treatment. Radiological imaging remains the mainstay of disease assessment. This review aims to illustrate the radiological features of CKD-MBD, such as secondary hyperparathyroidism, osteomalacia, adynamic bone disease, soft-tissue calcifications; as well as features associated with renal replacement therapy, such as aluminium toxicity, secondary amyloidosis, destructive spondyloarthropathy, haemodialysis-related erosive arthropathy, tendon rupture, osteonecrosis, and infection.

CKD-mineral and bone disorder management in kidney transplant recipients

Kidney transplantation, the most effective treatment for the metabolic abnormalities of chronic kidney disease (CKD), only partially corrects CKD-mineral and bone disorders. Posttransplantation bone disease, one of the major complications of kidney transplantation, is characterized by accelerated loss of bone mineral density and increased risk of fractures and osteonecrosis. The pathogenesis of posttransplantation bone disease is multifactorial and includes the persistent manifestations of pretransplantation CKD-mineral and bone disorder, peritransplantation changes in the fibroblast growth factor 23-parathyroid hormone-vitamin D axis, metabolic perturbations such as persistent hypophosphatemia and hypercalcemia, and the effects of immunosuppressive therapies. Posttransplantation fractures occur more commonly at peripheral than central sites. Although there is significant loss of bone density after transplantation, the evidence linking posttransplantation bone loss and subsequent fracture risk is circumstantial. Presently, there are no prospective clinical trials that define the optimal therapy for posttransplantation bone disease. Combined pharmacologic therapy that targets multiple components of the disordered pathways has been used. Although bisphosphonate or calcitriol therapy can preserve bone mineral density after transplantation, there is no evidence that these agents decrease fracture risk. Moreover, bisphosphonates pose potential risks for adynamic bone disease.

Bone disease after kidney transplantation

Advances in immunosuppressive therapy have allowed for enhanced allograft survival in kidney transplantation. With this increasing success of transplantation, however, has come a greater appreciation of subsequent complications, such as bone and mineral disease. In patients with chronic kidney disease who are awaiting transplantation, disorders in mineral metabolism and renal osteodystrophy are an essentially universal finding, and several different pathophysiologic mechanisms are believed to contribute to the development of these disorders.

Bone disease after kidney transplantation

Kidney transplantation is the optimal form of renal replacement therapy for many with end-stage kidney disease. However, kidney transplantation comes with a unique set of medical complications, important among them is bone disease. Posttransplant bone disorders are manifestations of pathologic processes occurring posttransplant that are superimposed on preexisting disorders of bone and mineral metabolism secondary to kidney failure and/or diabetes mellitus. As a consequence of early rapid bone loss, which is seen commonly within the first 3 to 6 months of transplant, the fracture risk posttransplant increases and has been reported as high as 5% to 44%. Posttransplant fractures occur more commonly at peripheral than central sites. Patients with a history of diabetes mellitus are at particular risk for fracture. Parathyroid hormone (PTH) and osteocalcin levels generally decrease after transplantation. Alkaline phosphatase and urinary collagen cross-links are unpredictable. Bone histology varies. No single biomarker unequivocally distinguishes between the various bone disorders found on biopsy examination. Immunosuppression is a major cause of posttransplant bone disorders. Glucocorticoids lead to decreased bone formation whereas the calcineurin inhibitors appear to cause increased bone turnover. Evaluating and managing posttransplant bone disease is an integral part of posttransplant medical care.

Arthroscopic treatment of bilateral humeral head osteonecrosis

A 37-year-old woman with a renal transplant was treated by arthroscopic debridement for bilateral steroid-induced humeral head osteonecrosis. Radiologically, the right shoulder had been categorized as stage III and the left as stage IV according to Arlet and Ficat. Relief of pain and improved range of motion were obtained especially on the right shoulder. Arthroscopy is an efficient procedure for treatment of humeral head osteonecrosis in the renal transplant recipient including radiological stages III with episodes of locking.

The pathogenesis of osteonecrosis and the relationships to corticosteroids

One of the challenging issues faced by allergists is a risk-benefit analysis on the use of corticosteroids. An uncommon, but serious complication of corticosteroids is the development of avascular necrosis (osteonecrosis). In this review we present the differential diagnosis and pathophysiology of osteonecrosis, with particular emphasis on steroids. Osteonecrosis of the femoral head is a common disorder that may be either naturally occurring or iatrogenic. With the exception of those cases labeled as idiopathic, the majority are the result of some insult to the vascular integrity of the affected hip. The reason for this disruption is manifold and can range from direct trauma to the more subtle or indirect compromise associated with fatty emboli or often an intravascular event such as that seen in sickle cell anemia. Although they are not totally understood, corticosteroids present a special problem because of susceptibility factors that may make some patients more likely to get osteonecrosis than others. The problem may be more complex, in that the association between corticosteroid use and osteonecrosis may be disease-dependent. In any case, any patient receiving long-term corticosteroids should be warned of this potentially debilitating complication.

Avascular necrosis of bilateral knees secondary to corticosteroid enemas

Avascular necrosis (AVN) is a devastating adverse effect of corticosteroid therapy rarely reported in the setting of inflammatory bowel disease. We describe a 48-year-old woman with 6 weeks of progressive bilateral knee pain resulting in the inability to ambulate. Her symptoms developed suddenly, 9 months after treatment with hydrocortisone enemas for ulcerative proctitis. On physical examination, the patient had knee tenderness, decreased range of motion, and flexion contractures. Magnetic resonance imaging showed multiple bony infarcts in bilateral distal femora and proximal tibias, consistent with advanced AVN. Initial therapy included pain management, serial casting, gentle flexibility and strengthening, and limited mobility training. The rehabilitation efforts led to functional improvement. Ultimately, bilateral total knee arthroplasties were recommended to treat her advanced AVN. This is the first reported case of AVN secondary to hydrocortisone enemas. We review the literature and discuss the pathophysiology and management of corticosteroid-induced AVN.

Guidelines for surgical procedures after liver transplantation

OBJECTIVE

The first purpose of this study is to identify the types and incidences of surgical procedures in patients who have previously undergone liver transplantation, with particular focus on the complication rates and the lengths of hospital stay. The second purpose is to present the management guidelines for patients with liver transplants at the preoperative, intraoperative, and postoperative stages of surgical procedure.

SUMMARY BACKGROUND DATA

The surgical literature on this issue is scant, and with the growing liver transplant patient population it is not unlikey for any surgery specialist to have to operate on a patient who has undergone liver transplantation.

METHODS

A sample of 409 patients with available hospital records, with a minimum of a 2-year follow-up, and with telephone access for interviews was chosen. Type of surgery, time from the liver transplant, hospital stay, immunosuppressive regimen, and complications were recorded.

RESULTS

A large proportion of patients (24.2%) underwent some type of surgical procedure 2 to 10 years after liver transplantation. The authors demonstrate that most of the elective procedures can be safely carried out without an increased incidence of complication and without longer hospital stay than the general population. Conversely, emergent procedures are plagued by a greater incidence of complications that not only affect the function of the liver graft but may risk the life of the patient.

Osteonecrosis: current perspectives on pathogenesis and treatment

Nontraumatic osteonecrosis results from impairment of circulation to the affected bone. The femoral head is affected most frequently. The underlying cause for the circulatory defect in osteonecrosis varies and may involve both local and systemic changes. Steroid use, alcohol consumption, pancreatitis, and lipid disorders appear to lead to bone death either by development of fat emboli in the microcirculature surrounding the affected bone or by fatty infiltration of the marrow. Decompression syndrome results from the presence of gaseous emboli in the microcirculature. In Legg-Calvé-Perthes disease other associated features are present such as short stature, suboptimal growth velocity, and/or hormonal imbalances, and it is likely that osteonecrosis may be secondary to systemic abnormalities, although specific factors have not been identified. Other frequently suggested pathogenic factors that play a role in the development of osteonecrosis include increased intraosseous pressures, the presence of cytotoxic cellular factors, intravascular coagulation, venous stasis, and the hyperviscosity syndrome. Some investigators have attempted, without success, to find a common etiology for all cases of osteonecrosis. In addition, patients have developed osteonecrosis without any known risk factors; this syndrome has been coined idiopathic avascular necrosis. In advanced stages of femoral head osteonecrosis, total hip arthroplasty appears to be the best therapeutic modality, particularly in older individuals.

Musculoskeletal complications after renal transplantation: pathogenesis and treatment

Renal transplantation is associated with several abnormalities of function and structure of the musculoskeletal system. Some of these skeletal problems result from incomplete resolution of abnormalities of bone and mineral metabolism present at the time of transplantation. In this regard, persistent hyperparathyroidism, diabetes mellitus type 1, and accumulation of beta 2-microglobulin may lead to residual skeletal effects despite excellent function of the allograft. Persistent hyperparathyroidism may accelerate bone loss and increase the risk for osteonecrosis, as well as cause hypercalcemia and hypophosphatemia; some patients with severe hyperparathyroidism require parathyroid surgery. Osteonecrosis is the most debilitating skeletal complication after transplantation and frequently requires surgical therapy. Although osteomalacia associated with aluminum overload generally resolves after transplantation, bone complications due to dialysis amyloidosis and diabetes mellitus type 1 often fail to improve. Alternatively, skeletal abnormalities can be acquired after transplantation. Most of the new derangements of bone and mineral metabolism are due to the immunosuppressive medications. Toxic effects of glucocorticoids on bone contribute to the pathogenesis of osteonecrosis, increase the risk for fractures by decreasing cancellous bone mass and synthesis of bone matrix, and dampen the linear growth response in pediatric recipients. Whether cyclosporine independently causes appreciable toxic effects on bone metabolism is not yet clear, but use of this drug increases the prevalence of gout and dental problems. Osteonecrosis, osteopenia, and short stature remain important skeletal complications in recipients of renal allografts. Therapeutic efforts should be directed toward alleviating pretransplant bone disease and attenuating bone loss after transplantation.

Dysbaric disorders: aseptic bone necrosis in tunnel workers and divers

Dysbaric osteonecrosis is a serious complication for those exposed to a hyperbaric environment, with prevalence of 17% amongst compressed air workers and 4.2% amongst divers. Bone lesions are characteristically multiple and bilateral, occurring frequently in the shafts of the femora or tibiae and the heads of the humeri or femora. A proportion of the lesions will lie next to the joint surface, the so called juxta-articular lesion, and these may progress to a structural failure and secondary osteoarthritis. These lesions can be severely disabling, especially in a young adult male. When related to the occupational history the prevalence of bone lesions, both in compressed air workers and divers, increases with age, experience and with greater pressures of air or at greater depths. Moreover, acute attacks of decompression sickness, the bends, are more liable to be associated with subsequent bone lesions. Current decompression schedules certainly reduce the bends rate but, no matter how strictly adhered to, will not prevent the development of dysbaric osteonecrosis. It is possible that bone necrosis could result solely from exposure to a high pressure of air, either from work in compressed air or diving. Those men with positive bone lesions should be advised to seek expert medical opinion and probably advised to discontinue work in compressed air or diving if a juxta-articular lesion is present. Detection of bone necrosis depends on good quality radiographs with reliable interpretation, preferably by double observation, especially in the early stages. Lesions, especially when early or doubtful, can be confirmed by CT or bone scintigraphy. MRI promises to detect osteonecrosis in the very early stages but is not yet readily available. To detect dysbaric osteonecrosis at an early stage it is important to monitor both compressed air workers and divers with regular radiological skeletal surveys or bone scintigraphy. In 1987, the Bone Necrosis Working Group of the Decompression Sickness Panel recommended that all divers should have a radiological survey on completion of their initial diving training and that bone scintigraphy should be used for subsequent surveillance for certain groups, including those diving deeper than 30 metres, where the time at depth exceeds 4 hours, when experimental decompression is used and in other situations.