Research Article: Atraumatic femoral neck fracture during bisphosphonate treatment: case report and review of the literature

Date Published: October 27, 2017

Publisher: Springer International Publishing

Author(s): Robert Wilk, Damian Kusz, Hanna Grygiel, Magdalena Grosiak, Jakub Kamiński, Marcin Kusz.

http://doi.org/10.1007/s40520-017-0846-0

Abstract

Partial Text

Postmenopausal osteoporosis is a metabolic bone disease that affects a significant part of the population. Preventing fractures of the femoral neck is one of the most pressing issues in the treatment of osteoporosis. Bisphosphonates (BPs) are highly recommended in people suffering from osteoporosis. They are proven to inhibit bone resorption and also proven to have anti-fracture efficiency. However, treatment using BPs does not completely eliminate the risk of fractures. In this article we present a female patient with a non-traumatic fracture of the femoral neck who regularly ingested oral BPs for 3 years as a preventative
treatment.

A 57-year-old woman was admitted to the Department of Orthopaedics and Traumatology because of severe pain localised on the lateral side of the right thigh and the right groin. The patient complained of pain a month prior to admission. There was no known history of injury due to falling. Despite the pain, the patient was able to walk unassisted. Then after 1 week the patient lifted minor weights which caused a slight hip sprain during flexion of the spine, the patient’s condition rapidly deteriorated. Initially, lumbar radiculopathy was misdiagnosed. The patient was treated with nonsteroidal anti-inflammatory drugs, specifically dexketoprofen, naproxen and ketoprofen, first orally and secondly intramuscular. The treatment was ineffective and the pain increased; subsequently the patient was taken to the Accident and Emergency Department. During initial clinical examination shortening and external rotation of the right lower limb was revealed. Lasègue test was negative. Due to intense pain the patient’s mobility was limited and she was unable to bear any weight; crutches were given to assist with walking. Her past medical history revealed osteoporosis, no other complication was indicated. Due to an ankle sprain 3 years prior a dual-energy X-ray absorptiometry (DEXA) was performed by a general practitioner which revealed low bone density. The patient had a T score of − 2.7 and Z score of − 1.7 at the lumbar spine. The patient was treated with an oral BP (ibandronic acid 150 mg monthly), plus an oral supplementation of vitamin D3 (1250 U daily) or vitamin D3 plus calcium (1000 U and 500 mg daily, respectively) for 3 years, alternately. The patient’s occupation was a caretaker at a nursery school for 28 years. She describes her job as ‘slightly physical’. She reached menopause 8 years ago, no hormone replacement therapy was used. There was no known history of smoking or alcohol abuse. Her physical activity was normal and she did not reveal any eating disorders. Her mother also suffered from osteoporosis. Analysis of the blood prior to the surgery revealed low levels of sodium chloride and creatinine, and a high platelet count. All other laboratory tests were within normal range (Table 1). According to the standard protocol the levels of Vitamin D and parathormone serum were not checked. She did not present any clinical symptoms of hyperparathyroidism. The patient’s height was 159 cm, weight was 56 kg, and Body Mass Index (BMI) was 22.15. Radiographs taken prior to admission revealed a basicervical fracture of the proximal right femur with slight displacement (vertical, smooth-looking fracture line). There were no other pathological signs (Fig. 1). The neck-shaft angle on the contralateral proximal femur was 130°. The chest x-ray did not reveal any pathology besides slight atherosclerosis of the aorta and degenerative changes of the thoracic spine. She underwent surgery for closed reduction and internal fixation of fracture using titanium trochanteric nail (130°/10 × 180 mm) (Fig. 2). Post-surgical treatment included physical therapy and the patient continued pre-fractural osteoporosis treatment which included Ibandronic acid. Ibandronic acid was not converted into other drugs such as Teriparatide. Normal fracture healing was observed 3 months post-surgery (Fig. 3). A subsequent follow-up was conducted 8 months post-surgery which revealed the patient walked without crutches. However, the patient limped and complained of slight pain at the right hip.

Nowadays, BPs are the first-line treatment for osteoporosis worldwide [1]. However, they have some possible side effects, such as atypical fractures [2, 3]. There are a wide variety of fractures reported at rare locations such as the distal fibula, ulna, tibia, metatarsus, pubis, ilium; however, fractures of the femur (subtrochanteric or diaphyseal) are the most common [4–10]. Our patient presented a basicervical fracture which is new and at a very unexpected location. Several cases of such fractures were reported to date. Previous reports described patients treated with different BPs—alendronic acid (three patients), cyclical etidronate (one patient) and one with ibandronic acid similar to the patient in this study [11–14]. Although treatment with BPs is highly recommended and commonly prescribed for osteoporosis to reduce the risk of hip fracture, preceding case reports show that it may also provoke femoral neck fracture.

 

Source:

http://doi.org/10.1007/s40520-017-0846-0

 

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