Sliding valgus osteotomy for bilateral neglected femoral neck fractures in young patient with renal osteodystrophy: A case report

Abstract

BACKGROUND

Bilateral femoral neck fractures in a young patient are uncommon, and they might occur in patients with bone metabolism disturbances such as renal osteodystrophy associated with end-stage renal disease. Furthermore, the condition becomes more challenging if the patient is presented late with a neglected fracture.

CASE SUMMARY

We describe a case of a 15-year-old male with end-stage renal disease on regular hemodialysis who presented with bilateral femoral neck fractures 6 weeks after experiencing a simple fall. The patient was successfully treated with staged bilateral sliding subtrochanteric valgus osteotomies and fixation with a 135° dynamic hip screw. His radiological and functional outcomes at 18 months postoperatively showed complete union of the fractures and the osteotomy sites with excellent hip function per the Children’s Hospital Oakland Hip Evaluation Scale.

CONCLUSION

This case underscores the importance of individualized surgical strategies in managing such fractures in this specific patient population, considering the medical comorbidities to achieve fracture union and to restore hip function.

Key Words: Femoral neck fracture; Renal disease; Subtrochanteric valgus osteotomy; Pediatric; Neglected; Case report

Core Tip: Neglected femoral neck fracture in the pediatric population is challenging to treat; moreover, it is more challenging in neglected cases. In the current report we presented a case of bilateral neglected femoral neck fracture in a pediatric patient suffering from end-stage renal disease. The management aim was to achieve fracture union in an acceptable anatomical position and overcome the obstacle of poor bone quality. These goals were achieved by performing staged bilateral sliding subtrochanteric valgus osteotomies. By the last follow-up at 18 months, fracture union was achieved with acceptable functional outcomes. Performing a sliding subtrochanteric valgus osteotomy was appropriate for correcting the fracture biomechanics and achieving early stability and fracture union.

INTRODUCTION

Pediatric femoral neck fractures (PFNFs) constitute about 0.5%-1.0% of all fractures in the pediatric population; furthermore, simultaneous bilateral fractures are rarely seen, and if present they might indicate significant trauma[1-3]. Apart from severe traumatic events leading to bilateral femoral neck fracture in a pediatric or adolescent patient, it might occur as a consequence of certain metabolic bone diseases, such as vitamin D deficiency, or renal osteodystrophy[3-6]. The management algorithm of PFNF is well reported in the literature when presented early. However, for late presentation or neglected cases (presented 30 days after the index trauma)[7,8], the decision is individualized for each patient. The underlying disease, fracture classification, need for a subtrochanteric valgus osteotomy, and bone graft necessity are considered[6,8-11]. The current report aimed to present the management and outcomes of a rare case of neglected bilateral femoral neck fracture in a pediatric patient suffering from end-stage renal disease.

CASE PRESENTATION

Chief complaints

A 15-year-old male was referred from the Department of Pediatric Nephrology for assessment of bilateral hip pain.

History of present illness

The patient experienced a simple fall 6 weeks prior to presentation and was unable to walk after the incident.

History of past illness

The patient was diagnosed with end-stage renal disease due to obstructive uropathy. He was treated with regular hemodialysis.

Personal and family history

The patient had no relevant personal or family medical history.

Physical examination

On examination both lower limbs were externally rotated, and both hips were tender with a limited range of motion. Other musculoskeletal evaluations were unremarkable.

Laboratory examinations

Laboratory investigations showed the following: Hypocalcemia (total calcium 7.8 mg/dL; reference 8.8-10.8 mg/dL); hyperphosphatemia (phosphorus 6.6 mg/dL; reference 3.0-5.5 mg/dL); severe 25-hydroxyvitamin D deficiency (8 ng/mL; sufficiency ≥ 30 ng/mL); elevated intact parathyroid hormone (169 pg/mL; reference 15-65 pg/mL); and increased bone-specific alkaline phosphatase (187 μg/L; reference 15-90 μg/L). These findings were suggestive of renal osteodystrophy with secondary hyperparathyroidism.

Imaging examinations

Plain radiograph in the form of an anteroposterior view of the pelvis revealed bilateral displaced transcervical femoral neck fractures classified as Delbet type II with rounding of the bone ends indicating chronicity. Both femoral heads appeared intact with no signs of collapse or avascular necrosis (Figure 1A).

Figure 1 Radiographic series of a case with bilateral Delbet type II femoral neck fractures treated with staged bilateral sliding subtrochanteric valgus osteotomies. A: Initial anteroposterior pelvis plain radiographs showed bilateral Delbet type II displaced femoral neck fractures; B: Early postoperative plain radiograph after staged bilateral sliding subtrochanteric valgus osteotomies fixed using 135° dynamic hip screw and partially threaded antirotation screws, immediately and 6 weeks after operating on the right and left hip; C: Plain radiographs obtained 6 months postoperatively showed acceptable bony union and intact femoral heads; D: Final plain radiographs at 18 months postoperatively showed complete union of both femoral neck fractures and the osteotomy sites.

MULTIDISCIPLINARY EXPERT CONSULTATION

This was carried out by the pediatric nephrology team, who were consulted immediately after the patient’s presentation. In addition to helping establish the correct diagnosis, the team helped optimize dialysis timing, control electrolyte and mineral metabolism, manage anemia and fluid status, ensure peri-anesthetic clearance, and provide structured postoperative follow-up.

FINAL DIAGNOSIS

Neglected bilateral femoral neck fracture in renal osteodystrophy.

TREATMENT

After counseling the patient’s treating pediatrician to prescribe and follow-up on the medical management of the patient, considering the delayed presentation of the fracture and its configuration (Delbet type II and the vertical nature of the fracture), the decision was made to treat the patient surgically by bilateral sliding subtrochanteric valgus osteotomy and fixation using a dynamic hip screw (DHS).

The patient’s parents were counseled regarding the surgical decision and approved the procedure after being fully informed of the risks and possible complications. Based on the anesthesia team’s recommendations, we preferred to perform the surgeries as a staged procedure. The surgical procedures were performed as described in the literature, and fixation was performed using 135° DHS and antirotation partially threaded screws bilaterally; no bone graft was added (Figure 1B)[12-14].

OUTCOME AND FOLLOW-UP

The early postoperative period (first 2 weeks) for both hips went uneventfully, and the sutures were removed. The wound showed no signs of infection. The patient was allowed partial weight-bearing starting in the third postoperative week, progressing to full weight-bearing by the end of the eighth week. Follow-up plain radiographs at 6 months (Figure 1C) and at the last follow-up at 18 months (Figure 1D) showed complete union of the fractures and the osteotomy sites with a final neck shaft angle of 138° and 140° on the right and left hips, respectively, maintained position of the implants, and no signs suggesting avascular necrosis of the femoral heads. The functional outcomes were assessed using the Children’s Hospital Oakland Hip Evaluation Scale[15] at the last follow-up and showed scores of 91 and 92 out of 100 points for the right and left hips, respectively.

DISCUSSION

We described a rare case of bilateral neglected PFNF secondary to renal osteodystrophy. This condition was managed successfully in a staged manner by performing a subtrochanteric valgus osteotomy and fixation using a DHS; no bone graft was required. By the last follow-up, the fracture and the osteotomy sites were fully united, and the patient achieved acceptable functional outcomes.

Long-standing renal failure disturbs calcium homeostasis with adverse effects on bone, causing renal osteodystrophy, which was the leading cause of the fracture in the current case. Furthermore, alterations in normal bone composition can predispose patients to pathological fractures, including femoral neck fractures[16]. It is worth noting that in addition to surgical management of fractures medical treatment is paramount, and the integration of the pediatric team into the management plan is crucial[17].

Bilateral PFNF is relatively rare, and management should aim to achieve fracture fixation and fracture union in an acceptable anatomical position, preserve hip biomechanics, and help the child regain activity as quickly as possible. These goals are easily applied to fresh fractures[1,11]. However, in neglected PFNF, the decision is more challenging and carries a higher risk of complications[5,6,18]. In the current case the fracture was classified as Delbet type II with a nearly vertical fracture line. To avoid failure with just fracture fixation due to high shearing forces, we decided to proceed with a sliding subtrochanteric valgus osteotomy, which showed excellent results in the literature[5,6,10,13].

Apart from the hip preservation nature of the procedure, it provided further advantages: There was no need to remove bone wedges; blood loss was minimized; operative time was reduced; and limb-length discrepancies were kept to a minimum[14]. By adopting such a management strategy, we achieved complete union at the fracture and osteotomy sites, and hip function was excellent bilaterally.

CONCLUSION

Bilateral pediatric femoral neck fractures secondary to renal osteodystrophy in patients with end-stage renal disease pose unique challenges, and cooperation between different medical specialties for management is crucial. Sliding subtrochanteric valgus osteotomy offers a hip-preserving option with acceptable radiological and functional outcomes. This case highlighted its efficacy in achieving good outcomes, emphasizing the need for further research in managing such rare injuries.