Hyperparathyroidism is a condition that can be categorized as primary, secondary, or tertiary and is characterized by elevated calcium levels, decreased phosphate levels, and high levels of parathyroid hormone (PTH). Primary hyperparathyroidism can lead to significant bone resorption, resulting in bone pain and pathological fractures. It is the third most common endocrine disorder, after diabetes and thyroid disease. While not frequently documented, there have been instances of pathological fractures uncovering primary hyperparathyroidism. The major cause of primary hyperparathyroidism is parathyroid adenoma followed by follicular hyperplasia followed by parathyroid carcinoma ^[1]. Parathyroid adenoma is a progression of proliferative pathogenesis impacting the parathyroid gland, beginning with hyperplasia of parathyroid follicles and potentially leading to parathyroid carcinoma ^[2]. A majority of patients exhibit non-specific symptoms, such as fatigue, loss of appetite, polyuria, and polydipsia. Loss of appetite, bloating, and nausea are common intestinal symptoms, while musculoskeletal symptoms include osteoporosis, myalgia, and bone pain ^[3]. Confirmation of the diagnosis typically involves biochemical screening to detect increased levels of serum calcium, decreased levels of phosphate, and elevated levels of serum parathyroid ^[4]. As a result of the non-specific symptoms, it is unlikely for a parathyroid adenoma to be diagnosed solely based on the occurrence of an isolated fracture. This scenario can lead to mismanagement of the condition. The case presented involves a fracture of the bilateral femur whose cause was later identified as a parathyroid adenoma, leading to the exploration of the neck.

A 44-year-old female with insignificant past medical or surgical history presented to our outpatient department (OPD) with bilateral thigh pain after a trivial fall at home. Upon clinical examination, she was having pain and swelling over both thighs. Tenderness could be elicited over a proximal aspect of both thighs. The distal pulses and neurological examination were normal. The radiographs taken of the pelvis displayed a subtrochanteric fracture of the bilateral femur that was deemed pathological.(Fig. 1 & 2) As the fall was deemed insignificant, biochemical investigations were conducted to eliminate any likelihood of a metabolic disorder.

The patient’s biochemical reports indicated severe hypercalcemia (12.6 mg/dL, with normal levels ranging from 8.6 to 10.3 mg/dL), hypophosphatemia (2.3 mg/dL, with normal levels ranging from 2.8 to 4.5 mg/dL), elevated levels of serum PTH (907.7 pg/mL, with normal levels ranging from 11 to 51 pg/mL), hypercalciuria (234 nmoL/L, with normal levels ranging from 3 to 8 nmoL/L), and an increased alkaline phosphatase level (1550 IU/L, with normal levels ranging from 30 to 300 IU/L). Based on the biochemical findings, the patient was diagnosed with hyperparathyroidism. The bone densitometry results indicated values below −2.5 standard deviation, which suggested the presence of severe osteoporosis.

To rule out parathyroid disorder, ultrasonography (USG) of the neck was done which was suggestive of a hypoechoic lesion posterior to the thyroid (10 × 6 mm).(Fig. 3)To gather more information, we conducted a 4D computed tomography (CT) scan of the neck which showed a × 1.1 × 0.6 cm lesion in the posterior aspect of the left hemithyroid suggestive of parathyroid After consultation with the endocrinology and the surgery department,the patient underwent right and left inferior parathyroidectomy. Following the removal of the mass, there was a significant decrease in the patient’s PTH levels. By the 1^st post-operative day, PTH levels fell down to 65.4 pg/mL. To prevent hypocalcemia, the patient was given oral calcium and Vitamin D supplements after the operation. Subsequently, the removed mass was sent for histopathological examination (HPE), which indicated the presence of a parathyroid adenoma. The patient then underwent cephalomedullary nail fixation for bilateral subtrochanteric femur fracture in the same setting.

(Fig. 4) Following this, the patient underwent regular clinicoradiological examinations in the OPD, with a 1-month interval between each assessment. Following the excision of the parathyroid, the patient underwent regular clinicoradiological examinations in the OPD, with a 1-month interval between each assessment. The fracture was united by a 3-month follow-up, and repeat biochemical investigations at that time showed normal results. The patient’s follow-up was continued for a total of 6 months, during which there were no indications of recurrence, whether based on clinical or biochemical assessments. Upon completing a 6-month follow-up, the patient displayed a favorable functional outcome with fracture union.(Fig. 5) She reported no pain and was able to walk unassisted.

Hyperparathyroidism is a frequently occurring endocrine ailment that primarily affects postmenopausal women. The condition is usually detected by elevated levels of serum calcium and PTH in the body ^[5].

The initial diagnosis of adenoma generally involves USG and 4D CT scans, followed by confirmation through HPE. Due to the generally asymptomatic nature of parathyroid adenoma, diagnosis can be difficult. Furthermore, the occurrence of an isolated bone fracture in cases of parathyroid adenoma is rare, which can pose an additional challenge for diagnosis. After conducting an extensive search of PubMed, it was found that there are fewer than 10 recorded cases of pathological fractures resulting from parathyroid adenoma. In one such case, Bennett et al. (Table 1)reported a fracture sustained by an adolescent female in the right femoral neck ^[6]. This was managed by closed reduction, internal fixation using pinning, and the application of a hip spica cast. In one case reported by Buisset et al.,(Table 1) a 40-year-old female with a pathological left forearm fracture was managed conservatively using a cast ^[7]. It was later discovered that the patient had a right inferior parathyroid mass, which was treated through en bloc excision. Another similar case was reported by Terro et al.,(Table 1) where a 41-year-old male with a left clavicle fracture was treated conservatively ^[8]. The patient was found to have a giant parathyroid adenoma, which was managed through right lower parathyroidectomy. Upon the diagnosis of a pathological fracture, it is important to investigate metabolic bone diseases such as primary hyperparathyroidism and osteomalacia, along with conditions, such as multiple myeloma and bone metastasis ^[9]. Even mild cases of primary hyperparathyroidism can increase the risk of non-vertebral and vertebral fractures due to a decrease in volumetric densities within both the cortical and trabecular compartments of bones. This increased risk is supported by research findings [10, 11]. To make a conclusive diagnosis, one must consider the patient’s clinical history, radiological examination findings, and biochemical tests. These tests may include measuring serum levels of PTH, alkaline phosphatase, calcium, phosphate, and Vitamin D ^[12]. In cases of pathological fractures or significant cortical involvement, orthopedic interventions should be considered [13, 14]. We report an uncommon case of a pathological fracture resulting in a bilateral subtrochanteric femur fracture in a female patient who was previously asymptomatic. Despite the trivial nature of the fall that resulted in the fracture, a specific protocol for diagnosing parathyroid adenoma was followed in a planned and staged manner. Once the adenoma was excised and the fracture was fixed, normal biochemical markers were observed and the fracture united within 6 months of the follow-up. However, the main limitation of the study is the relatively short 6-month duration of follow-up since adenoma recurrence typically occurs within 2–3 years after excision. Therefore, a longer-term assessment may be necessary to determine the overall outcome.

Given the rarity of parathyroid adenoma, it is critical to maintain a high level of suspicion to diagnose bone fractures that present in an extremely uncommon manner. It is important to keep primary hyperparathyroidism in mind when dealing with bone lesions connected to hypercalcemia since this disorder is typically asymptomatic. The best way to diagnose and treat such conditions is to combine clinicoradiological and biochemical studies with the expertise of specialists in handling pathological fractures. To achieve the best possible outcome for such rare presentations, a multidisciplinary approach is recommended.

A diagnosis of the underlying pathology can be achieved by utilizing a combination of clinicoradiological and biochemical studies. It is important to maintain a high index of suspicion to ensure an accurate diagnosis.