ABSTRACT

CORRESPONDING AUTHOR:
Dr. Patnala Ashok Kumar,
Associate Professor,
Department of Orthopaedics,
King George Hospital,
Visakhapatnam-530002.
E-mail: ashok_ortho59@rediffmail.com

ABSTRACT: We here with present a case of bilateral spontaneous femoral neck fracture in a middle aged male patient suffering from undiagnosed renal osteodystrophy. He undergone bilateral uncemented hemiarthroplasty and is receiving treatment for renal osteodystrophy and other deficiencies caused by chronic renal disease. Our aim is to present a rare case of bilateral fracture of the neck of femur secondary to renal osteodystrophy with an atypical presentation, simulating bilateral osteoarthritis of the hip. We also want to stress upon the importance of evaluation of serum Calcium, Phosphorous, Vitamin D, Parathyroid hormone and Alkaline Phosphatase levels in patients with chronic renal disease, even though the patient is not in the End stage renal disease.

KEYWORDS: Bilateral Femoral Neck fracture, Renal Osteodystrophy, Simultaneous Fractures.

INTRODUCTION: Spontaneous simultaneous femoral neck fractures are very rare. We present herein a case of non-traumatic spontaneous simultaneous bilateral femoral neck fracture in a 32 year old male patient, secondary to renal osteodystrophy. Our aim is to present a rare case that we came across. Patient was informed in the language he understands that the data concerning his case would be submitted for publication and he gave his consent.

CASE REPORT: A 32yr old male patient attended orthopedic OPD in our hospital with chief complaints of pain in both groins of one year duration. The pain started 1yr ago, insidious in onset and was dull aching type without any radiation. It was not preceded by trauma or fever and was aggravated by activities and relieved by rest and analgesic medications. The pain gradually progressed to its present severity where it is unbearable and uncontrollable and is not relieved even with high doses of analgesics and is affecting his daily activities like squatting, sitting cross legged, standing for more than 5min and walking for more than 10steps. There is no loss of weight and appetite or other constitutional symptoms at the time of presentation. In the past, the patient had episodes of severe muscle weakness for which he was given oral potassium chloride but was unaware of the previous diagnosis.

The patient was moderately built and nourished and was pale on inspection. He had a waddling gait. On inspection of both hips, there were no significant findings. There was no apparent discrepancy in limb length or obvious deformities. There was bilateral anterior joint line tenderness and pain on passive range of movement of both hips. The movements of both hips were restricted, particularly the rotations. Trendelenberg test could not be done as the patient was not able to stand even for few minutes and telescopy was absent both sides. His spine and both sacroiliac joints were clinically normal. With the given history and clinical findings, we arrived at a provisional diagnosis of bilateral secondary osteoarthritis of hips most probably due to bilateral avascular necrosis of femoral head. Hence, we admitted the case for further evaluation.

Once we admitted the case we started the baseline investigations. We completed the routine blood work and a plain radiograph of pelvis including both hips was taken. The blood tests included Hemoglobin (8.4 mg/dl), Blood urea (24mg/dl), Serum creatinine (2.0mg/dl), and Random blood sugar (82mg/dl). Radiographs of pelvis with both hips showed bilateral Garden’s type 3 femoral neck fractures. Now considering the previous history of muscle weakness(for which he has been using potassium chloride), his blood urea, serum creatinine values and the features of osteoporosis (which is usually secondary in this age group) in the radiographs, we felt that further evaluation of the patient was necessary to rule out chronic renal disease.

For renal evaluation we referred the patient to the Nephrology department, who conducted various investigations including Complete Urine examination [Urine Potassium 28.4 mEq (<15 mEq)], Complete Blood Series, Serum Electrolytes (Serum potassium 2.8 mEq/litre), Arterial blood gas analysis and Ultrasound abdomen. After they examined the reports thoroughly and calculated the Glomerular Filtration Rate [(140-age) x Body weight/ (Serum creatinine x 72)], they affirmed that the patient has Grade 2 Renal Failure (according to GFRs)

It was then that we proceeded with collecting the Vitamin D 11.5ng/dl (normal range 25-75ng/dl), Calcium 6.9 mg/dl(8.5-10.5 mg/dl), Phosphorous 8.6 mg/dl (2.8-5 mg/dl), Alkaline phosphatase 769 U/litre (30-135 U/litre) and Parathyroid Hormone 46.2 pg/ml (8.8-76.6 pg/ml) levels and finally arrived at the conclusion that the patient was a case of Renal Osteodystrophy (low turnover type).

FIG. 1 : PLAIN X-RAY SHOWING BILATERAL FEMORAL NECK

FIG. 2: 3 D CT SHOWING BILATERAL FEMORAL NECK FRACTURE

FIG. 3: CT AXIAL CUTS SHOWING BILATERAL FEMORAL NECK

Fig. 4: Coronal cuts MRI showing bilateral femoral neck fracture

with noevidence of avascular necrosis

Apart from fractures the radiographs also show areas of osteoporosis. Biochemical serum studies showed that Vitamin D was 11.5 ng/dl(normal 25- 75 ng/ml), Calcium was 6.9 mg/dl(8.5-10.5mg/dl), Phosphorous 8.6 mg/dl (2.8-5 mg/dl) , Alkaline phosphatase 769 U/lt (30-135 IU/lt) and Parathyroid Hormone 46.2 pg/ml(8.8-76.6 pg/ml), Urine Potassium 28.4 mEq (normal <15 mEq). MRI of the Pelvis including both the hips was done to confirm that there was no evidence of Avascular necrosis of the head of the femur on either side.

After complete work up, we planned to do a Two Staged Bilateral Un cemented Hemi arthroplasty, Staged one week apart.

 AFTER STAGE 1                                            AFTER STAGE 2

FIGURE 5 & 6: THE PATIENT UNDERWENT 2-STAGED UNCEMENTED BIPOLAR HEMIARTHROPLASTY STAGED 1 WEEK

He had an uneventful postoperative course with complete pain relief following surgeries. He was started on an intensive rehabilitation program. At the 6 week follow up, the patient recovered completely and could walk without assistance. He was given Vitamin D and Calcium supplements along with Bisphosphonates and Potassium chloride. At the 6 month follow up repeat biochemical serum studies showed values within normal limits.

DISCUSSION: Spontaneous simultaneous bilateral femoral neck fractures are rarely reported. They have been associated with chronic conditions causing osteoporosis such as hyperparathyroidism, vitamin D metabolism defects, multiple myeloma, post organ transplantation; narcotic drug abuse, long term bisphosphonates usage, steroid induced osteoporosis and pregnancy induced transient osteoporosis. Additionally, it is noted that few cases were reported on spontaneous simultaneous bilateral hip fractures associated with osteomalacia in adult patients.

However, there are some differences regarding clinical and biochemical presentation of these cases. David Schnadower¹ et al stressed that pediatric patients should be evaluated for bilateral femoral neck fractures immediately after severe hypocalcemic seizures. Ruben Depasqale² et al found that, though bisphosphonates have a well-established therapeutic role in prevention of osteoporosis, long term use of bisphosphontes showed direct relationship to subtrochanteric and femoral diaphyseal fractures.

S Lidder³ et al reported bilateral femoral neck fractures secondary to transient osteoporosis during pregnancy. Alireza Hootkani⁴ et al attributed bilateral femoral neck fracture to narcotic drug abuse. Raphael Omatayo Ayorinde and Clement Abu Okolo⁵ reported concurrent femoral neck fracture following pelvic irradiation. H.D.W. Powell⁶ published three different cases of bilateral femoral neck fractures with convulsions as common history. Asheesh Sood⁷ et al discovered that in elderly, even in absence of primary and secondary bone disease, bilateral neck of femur fractures can occur after relatively minor trauma. Chirurgische⁸ et al described bilateral femoral neck fractures with Osteogenesis Imperfecta tarda. Pankaj⁹ et al described bilateral femoral neck fractures in post-knee arthroplasty subject. Sivas¹⁰ et al reported simultaneous bilateral femoral neck fractures in young patients with osteomalacia associated with hypermagnesemia secondary to overuse of magnesium containing antacids.

Renal Osteodystrophy is usually a diagnosis of end stage renal disease. However, it can be brought into light with high suspicion in a patient with chronic muscle pain and localized groin discomfort, in spite of not having history of trauma, as in this case. It might also be an incidental finding with chest and pelvis X-ray showing Looser’s zones or spine showing Rugger Jersey spine along with serum studies. It might present as bone pain, joint pain or bone deformation and bone fractures.

Renal Osteodystrophy can be of two types. High turnover renal bone disease and low turnover renal bone disease. High turnover type is associated with raised parathyroid hormone levels. Low turnover type (as seen in this case) with low or normal levels of parathyroid hormone is uncommon. Chronic renal disease results in deficiency of vitamin D and thereby reduces the intestinal absorption of calcium, phosphorous and magnesium. Low levels of calcium leads to secondary hyperparathyroidism with bone resorption. Alternatively, in low turnover state the parathyroid hormone levels are within normal range but pathology is due to excess deposition of aluminum into bones, which again ultimately lead to bone resorption and weakness along with inadequate mineralization.

David Schnadower¹ et al performed open reduction and internal fixation of both femoral heads in his pediatric subject. Ruben Depasquale² et al stopped the subject from taking Alendronate and started him on vitamin D and calcium supplements since their subject had history of multiple fractures and was uneventful. S Lidder³ et al conservatively treated the subject until delivery and then operated on the subject. Alirezia Hootkani⁴ et al treated the subject with bilateral single staged hemiarthroplasty. Raphael Omatayo Ayorinde⁵ and Clement Abu Okolo concluded that African blacks are predisposed to hip fractures following pelvic irradiation and treated with bilateral hemiarthroplasty with uncemented Austin Moore stems at 8 weeks interval.

Asheed Sood⁷ et al treated the elderly with cemented hemiarthroplasty using Thompson stem. Chirurgische⁸ et al implanted a cemented total endoprothesis bilaterally in a single stage operation. Although Mcbryde¹¹ et al recommended single stage procedure in elective surgery; Tsiridis12 et al noticed the need for more blood transfusions in single staged procedures than in staged procedure. Whatsoever is the method, Orthopedic surgeons should concentrate on restoring the normal anatomy apart from therapeutic vitamin D, calcium supplements and bisphosphonates.

CONCLUSION: This case highlights that in chronic renal disease subjects, even though there is an absence of secondary hyperparathyroidism, decreased bone mineralization and excess deposition of aluminium can lead to bilateral femoral neck fractures , in spite of the fact that the patient claiming that he did not sustain a trivial trauma. Consequently the orthopedic surgeon, emergency physician and general practitioner should be aware of this condition and should treat the subject of chronic renal disease with groin discomfort with high index of suspicion, though the subject is not in end stage renal failure and they do not present clinically as a typical fracture.

CONSENT: Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-chief of this Journal.

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