Background

Renal osteodystrophy (RO) secondary to chronic kidney disease (CKD) is an established cause of pathological femur neck fractures [1]. The incidence of hip fracture in patients undergoing haemodialysis (HD) is significantly higher than that in the general population. The incidence of hip fracture in dialysis patients is 4.4 times higher than that of the general population [2], and its incidence is 29.3 / 1000 people / year [3]. However, simultaneous bilateral femoral neck fractures (SBFNFs) in patients on dialysis are extremely uncommon [4]. We report a rare case of SBFNFs in a middle-aged patient on dialysis and review SBFNFs in patients with CKD.

Case presentation

The patient was a 47-year-old female with no history of trauma who developed bilateral hip pain 1 day prior to admission. She had a history of haemodialysis due to polycystic kidney disease. Upon physical examination, she demonstrated inability to move the hip joints and bilateral inguinal tenderness. Laboratory studies showed anaemia (haemogram 8.5 g/dL), a low normal albumin value (3.1 g/dL), a high parathyroid hormone level (907 pg/ml), hypocalcaemia (5.1 mg/dL), hyperphosphatemia (2.3 mmol/L), and elevated alkaline phosphatase activity (1228 U/dL). Hip X-ray (Fig. 1a) and CT (Fig. 1b, Fig. 1c) examinations showed bilateral femoral displaced fractures. Bone mineral density testing revealed osteoporosis (T = 3.0). She also had a history of hyperparathyroidism secondary to CKD and parathyroidectomy.

Fig. 1
figure 1

a: Hip X-ray showing bilateral femoral displaced fractures with low bone density. b: CT scan showing the femoral displaced fracture on the left side. c: CT scan showing the femoral displaced fracture on the right side. d: Bilateral femoral displaced fractures treated with bilateral hip hemiarthroplasty

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We promptly performed a multidisciplinary team consultation to make preoperative preparations and performed the surgery 4 days after admission. Considering her mobility and life expectancy, we performed concurrent bilateral hip hemiarthroplasty with cement prostheses (Fig. 1d). The operative findings included severe osteoporosis and displaced femoral neck fractures. Anti-osteoporosis medication was administered after surgery. Meanwhile, the patient continued maintenance haemodialysis. Three days after the operation, she could ambulate with a walker. The follow-up appointments at 3 and 6 months revealed that the woman had gradually regained her previous ability to walk.

Discussion and conclusions

SBFNFs in patients on dialysis are relatively rare. To the best of our knowledge, only 10 cases have been reported previously, making our case the 11th (Table 1) [1, 5,6,7,8,9,10,11,12,13,14]. SBFNFs are usually secondary to seizure disorders [15], trauma [16], electric shock injuries [17], hypovitaminosis D [18], osteoporosis [19], and metabolic diseases. Stress fractures of the bilateral femoral neck occasionally occur in young patients [20]. It has been reported that the incidence of hip fractures in the general population has decreased significantly [21]. In the contrary, the incidence of hip fractures among haemodialysis patients is increasing [22, 23]. However, in Japan, compared to the general population, in Japanese dialysis patients, the incidence of hip fractures decreased among women but did not change among men between 2008 and 2013 [24]. Although the incidence of hip fractures appears to have decreased slightly, it remains a challenging problem in dialysis patients for both orthopaedic surgeons and nephrologists [25].

Table 1 Summary of all studies in the English literature reporting bilateral pathological neck femur fractures in chronic renal disease
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Among end-stage renal disease (ESRD) patients, HD is associated with a 61% higher risk of hip fracture than peritoneal dialysis (PD) [26]. Nevertheless, PD, HD, and kidney transplantation (KT) patients and HD and KT patients had the highest and lowest risk of hip fractures, respectively [27]. One study found that an advanced age, low body weight, low serum albumin level, and high alkaline phosphatase (ALP) and parathyroid hormone levels were associated with a low bone mass in HD patients [28]. The patient in our case had a parathyroid hormone level of more than 5000 pg/ml until undergoing parathyroidectomy. Thus, we suggest thatmaintaining an adequate body weight and serum albumin level, regular monitoring of the femoral neck bone mineral density, and undertaking an exercise programme are important to improve bone health in patients on HD.

Guidelines recommend that surgery for hip fracture should be performed within 48 h after the event. Delayed surgery for more than 48 h in elderly patients with hip fractures increased the risk of postoperative complications. However, in dialysis patients, a delayed operation did not contribute significantly to the mortality rate compared to that in the non-dialysis cohort [29]. The current study found that delaying surgery for a period of time did not negatively impact the incidence of postoperative complications [30].

Hip fractures are a common problem in the ageing population and are associated with significant mortality and morbidity rates. The mortality rate within 1 year after hip fracture is as high as 36% despite aggressive management, including surgery and rehabilitation [31]. Unfortunately, the incidence, mortality, and medical costs of fractures in patients with kidney disease are much higher than those of ordinary fractures [32, 33]. Patients with CKD often have a longer hospital stay after a fracture, and the chance of going to a skilled nursing facility after discharge is higher than that of patients without CKD. According to reports, more than 80% of fracture patients with CKD need skilled nursing facility after discharge form the hospital, which is much higher than other complications of CKD [34].

Femoral neck fractures are often treated with either internal fixation or artificial hip replacement. In the general population, treatment is performed according to age, bone quality, and fracture classification. In our case, we performed hemiarthroplasty according to the poor bone quality and life expectancy of less than 10 years. In the patient dependent on dialysis, the outcomes of arthroplasty are well described in the recent literature. Compared to non-dialysis-dependent patients, dialysis patients undergoing arthroplasty have suboptimal results with significantly higher incidence rates of deep venous thrombosis, surgical site infection, need for blood transfusions, wound complications, intensive care unit care, and attentive postoperative rehabilitation, as well as a 10–20 times greater risk of inpatient mortality [35, 36]. Some authors have suggested that arthroplasty should be approached with caution and preferably be delayed until after KT [37, 38]. In our case, blood transfusions were performed, and a seizure occurred 2 weeks after surgery. There are two possible factors may contribute to the high mortality in dialysis patients with hip fracture. The first is the higher prevalence of comorbidities and the second is the higher occurrences of postoperative complications. A personized surgical treatment based on specific clinical situations should be planned and carried out using a necessary risk assessment before surgery [39]. It should be noted that biological and mechanical failure can occur in the patients with RO and osteoporosis after hip fracture surgery [40]. Thus, a team approach involving expert nephrologists, geriatricians and orthopaedic surgeons is highly significant to reduce early complications and mortality. Dialysis patients with hip fracture require multidisciplinary assessment and intervention for the prevention of subsequent osteoporotic fractures. It can be difficult for dialysis patients to participate in rehabilitation while undergoing dialysis. Therefore, clinicians should highly pay attention to their standard rehabilitation.

In conclusion, hip fractures in HD patients pose serious challenges for surgeons. Clinicians should pay more attention to comprehensive treatment methods, which can reduce the morbidity and mortality rates of hip fractures in HD patients. A multidisciplinary team consultation for perioperative management is necessary and effective. Early diagnosis with prompt surgical treatment could lead to favourable recovery.