International Journal of Orthopaedic Surgery

CASE REPORT
Year
: 2021  |  Volume : 29  |  Issue : 1  |  Page : 21--25

Management of fibrous dysplasia of the femur neck in a child by PHILOS Stabilization, curettage, and bone grafting: A case report


Alok Chandra Agrawal, Ranjeet Choudary, Venishetty Nagaraju, Harshal Sakale 
 Department of Orthopaedics, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India

Correspondence Address:
Venishetty Nagaraju
Department of Orthopaedics, All India Institute of Medical Sciences, Raipur, Chhattisgarh.
India

Abstract

Fibrous dysplasia has a considerable risk of pathological fractures particularly in proximal femur in younger age group. These are challenging to treat, especially in pediatric population. Several treatment modalities have been proposed, each having its own pros and cons. Attention should be given in pediatric population in choosing technique and selection of implants to preserve growth of the limb and to prevent implant prominence and soft tissue irritation. We are reporting a case of pathological neck of femur fracture secondary to fibrous dysplasia, in an 11-year-old obese boy, managed with curettage, iliac crest bone grafting and osteosynthesis with PHILOS plate (a plate routinely used in adults for humerus neck fractures). At 6 months follow-up, he shows a good consolidation of iliac crest graft at fracture site with stable implant and an excellent functional outcome in terms of pain and range of motion, without any radiological sign of recurrence.



How to cite this article:
Agrawal AC, Choudary R, Nagaraju V, Sakale H. Management of fibrous dysplasia of the femur neck in a child by PHILOS Stabilization, curettage, and bone grafting: A case report.Int J Orthop Surg 2021;29:21-25


How to cite this URL:
Agrawal AC, Choudary R, Nagaraju V, Sakale H. Management of fibrous dysplasia of the femur neck in a child by PHILOS Stabilization, curettage, and bone grafting: A case report. Int J Orthop Surg [serial online] 2021 [cited 2021 Oct 27 ];29:21-25
Available from: https://www.ijos.in/text.asp?2021/29/1/21/324274


Full Text



 Introduction



Fibrous dysplasia (FD) is a non-heritable condition in which normal bone is destroyed and replaced with fibrous fibro-osseous tissue. It accounts for 5–7% of all benign bone tumors. Depending on the number of lesions and bone involvement, it might be monostotic or polyostotic. Polyostotic FD is less frequent and might be associated with endocrine problems, skin pigmentation abnormalities (McCune–Albright syndrome), or muscular myxomas (Mazabraud syndrome). Monostotic lesions have a lower rate of progression, but they are associated with a considerable risk of pathological fracture in up to 50% of cases, particularly in the proximal femur.

Pathological femur neck fractures are challenging for surgeons to fix because of the significant mechanical stresses operating at the hip joint. These fractures in children require specific attention to avoid sequelae such as growth issues and femoral head avascular necrosis.[1] Several treatment techniques, including casting, internal fixation with or without bone grafting, and osteotomy, have been proposed, each with advantages and disadvantages. We present a case of a pathological neck of femur fracture in an 11-year-old adolescent, treated with bone grafting and osteosynthesis using a PHILOS plate in this report.

 Case Report



An 11-year-old obese male child presented to the department of orthopedics with complaints of pain in his left hip and unable to bear weight following a fall from a bicycle. He had a history of dull aching pain in his left hip and limping when walking for the previous 2 years, for which he had not been evaluated or treated. On examination, the left hip was tender to touch, the straight leg test could not be performed, and hip movements were painful and limited in all planes. The ipsilateral knee, spine, and contralateral hip evaluations were all normal, with no neurovascular abnormalities. On a plain radiograph of the pelvis with both hips, there was a well-defined lytic lesion and ground-glass appearance with a pathological fracture across the femur neck area, with the balance of the femur normal [Figure 1]. Magnetic resonance imaging (MRI) revealed no soft tissue involvement and a benign cystic lesion [Figure 2]. Positron emission tomography-computed tomography revealed medium-sized, oval, expansile lytic lesion with internal septa and sclerotic rim involving left femoral neck with oblique pathological fracture. A core needle biopsy revealed irregular bone trabeculae devoid of osteoblastic component and surrounded by fibrous stroma, indicating FD. We planned curettage and bone grafting with internal fixation. Under anesthesia and aseptic settings, a lateral approach is used to make a 10 cm incision from the tip of the greater trochanter continuing distally. Soft tissue is dissected to reveal the proximal femoral neck. The lesion was curetted, and the fracture was reduced and held by 2 mm k-wires. Cancellous iliac crest bone graft from the same side was harvested and placed in the void. A three-holed proximal humerus interlocking system (PHILOS) plate was positioned laterally contour matching over the trochanteric region and fixed with transphyseal cortical and cancellous screws to ensure robust fixation in view of the significant void and resorption of femoral neck. Postoperatively, institutional standard antibiotic treatment followed. Histopathological evaluation of an intraoperative curettage sample reconfirmed the diagnosis of FD. Postoperatively, oral Ibandronic acid 150 mg tablet was advised every month. Weight-bearing deferred till radiological signs of union at three months. Now, after 6 months of follow-up, the patient has a painless stable hip and performing typical day-to-day activities [Figure 3], with Harris hip score of 90.60 and the radiograph shows good consolidation of iliac crest graft with stable implant [Figure 4].{Figure 1} {Figure 2} {Figure 3} {Figure 4}

 Discussion



FD is a benign bone disease characterized by abnormal bone and fibrous tissue developments as a result of progenitor cell accumulation and abnormal differentiation caused by a post-zygotic activating mutation in the GNAS1 gene. There is no age or gender preference for FD. Long bones, cranial bones, the pelvis, and the ribs are common sites of skeletal involvement. The most typically affected region is the proximal femur, and increasing microfractures and incomplete healing may develop “Shepherd’s crook deformity” of the proximal femur.[2] The monostotic type is common, detected during the patient’s growth phase, and usually remains asymptomatic until developed in a pathological fracture. Polyostotic FD is often discovered in infancy and is linked with various endocrinopathies, hyperthyroidism, and phosphaturia. These related comorbidities produce bone weakness and predisposition to pathological fractures.[3]

FD causes bone fragility due to local unwoven bone, endocrine or metabolic consequences, and decreased activity. As a result, extended immobility or non-weight-bearing is avoided. Internal fixation aids in early weight-bearing and should be considered wherever possible. Lower limb fractures in FD are often treated with internal fixation to give strength and to avoid refracture or deformity development. Due to future growth potential, surgical treatment with internal fixation of pediatric fractures, in particular femoral neck fractures, should have a different strategy from adults to prevent potentially injuring the growth plate and vascular insult to femoral head.[3],[4] The new bone formation following fracture is dysplastic and gives the possibility of recurring fractures and deformations. So fixed angled device or intramedullary (IM) devices are preferred to provide stability.[5]

The use of IM devices is strongly suggested for all lower extremity fractures.[4],[6] Standard adult IM devices generally do not fit into the small femoral shaft of growing children, with an open physis. The use of titanium elastic nails has shown good healing without physeal injury, but it will not prevent any deformity progression or subsequent fracture, making their use debatable.[7] Humeral nails and small diameter pediatric interlocking IM devices have been proposed,[7],[8] with limited data in the literature and associated drawbacks such as continuous deformation of the femur and introduction of the nails into the apophysis of the greater trochanter.

An angled blade plate was suggested to overcome these complications. Majoor et al.,[5] in their study, found good results with this device, but 7% of the patients developed fracture postoperatively. A stress riser at the end of the blade plate was implicated as a reason for fracture. The use of dynamic hip screws (DHSs) to stabilize a pathological fracture of the proximal femur has been established in the literature. However, larger lytic lesions in the femoral neck contradict it’s uses due to sever shortening of neck level arm, which can result in lurching. A compression hip screw combined with an allogeneic strut graft is used by Nishida et al.[9] in eight patients with a mean follow-up of 75 months, showing good results. However, use of these devices in the treatment shows a high failure rate compared with angled blade plates and IM nails.[10] Fractures distal to the plate are the main concern with these devices. As mentioned earlier, surgeons can use upper limb devices on a case-to-case basis.

The PHILOS plate may offer several advantages in the pathological fracture of the femoral neck in pediatric patients. First, it has stronger angular stability than traditional implants, allowing it to withstand greater forces in vertical femoral neck fractures. It functions as a locked internal fixator, providing greater screw anchoring and preventing fracture reduction loss. Secondly, FD destroys normal bone matrix and replaces it with fibro-osseous tissue, which lacks anchoring strength. There is a greater chance of implant failure and implant cut-out complication. PHILOS multiple screw fixation in different planes helps to prevent implant failure. Thirdly, PHILOS does not incorporate a dynamic compression mechanism, similar to that of a DHS, allowing it to be utilized in large bone voids filled with bone graft to minimize collapse. Fourth, PHILOS use is linked to decreased soft tissue injuries and periosteal stripping. Fifth, PHILOS plate application avoids trochanteric physis damage caused by IM nail fixation.

Curettage weakens the bone more and may lead to pathological fracture. Cancellable bones grafting of void is commonly used in pathological fracture to promote early union, but their overall effect on FD lesion is controversial. Cancellous grafts are rapidly reabsorbed and replaced by fibrous tissues; however, cortical autologous grafts survive longer than cancellous bone grafts, and allogeneic cortical bone grafts are replaced by a host bone at the slowest rate.[11] Furthermore, Kushare et al.[12] and Guille et al.[13] reported that lesions of FD were not resolved or diminished after curettage and bone grafting. Bone grafts do not halt disease progression or deformity as bone grafts are frequently resorbed.[4]

Oral bisphosphonates (BPs) have been used to treat FD and to inhibit osteoclastic remodulation of osteoid. It reduces the likelihood of a new fracture while simultaneously demonstrating radiological improvement such as progressive ossification of the lesion, cortical thickness, and reduction in lesion size. A pediatric population has been shown to have a beneficial impact in the treatment of FD similar to that of adults.

Early BP treatment obviously does not seem to hamper fracture healing either radiologically or clinically. Furthermore, a meta-analysis stresses the anti-resorption efficacy of BPs soon after surgical repair and should have a beneficial effect on the likelihood of future fractures.[14]

We used a proximal humerus interlocking system to provide proper anatomical contour in the trochanteric region and decrease hardware prominence or discomfort, which has not been recorded in the literature to the best of our knowledge. To improve osteogenic potential and fracture healing, an autologous cancellous bone graft was placed at the defect. Oral BPs are administered postoperatively to strengthen the bone and avoid future fractures. The patient had satisfactory fracture healing and an outstanding functional result at the 2-year follow-up, with no recurrence of lesion or pathological fracture.

 Conclusion



Despite the fact that numerous treatment modalities for pathological fracture neck femur in pediatric FD have been reported in the literature, all efforts should be made by the treating surgeon to minimize complications such as implant failure, hardware problems, recurrence of lesion, and fractures. Based on the success of our case, the PHILOS plate can be employed for internal fixation of a pathological fracture monostotic femoral neck lesion without long-term complications.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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