A steroid-induced bilateral avascular necrosis of the femoral head in an underage patient affected by multiple sclerosis

Summary

Patients affected by Multiple Sclerosis are often treated by pulsed intravenous corticosteroids to manage acute relapses with positive outcomes. The intravenous administration is frequently associated to avascular necrosis of several bones, particularly the femur. The present report regards a case of an underage MS patient with a bilateral ANFH secondary to pulsed administrations of steroids, managed by a conservative approach on a hip, and by a novel surgical technique on the contralateral side.

Introduction

Patients affected by Multiple Sclerosis (MS) are often treated by pulsed intravenous corticosteroids to manage acute relapses (1–3). Results are generally positive with early recovery from disabilities (2–4). The intravenous administration is not free from complications (5, 6). Frequently, an avascular necrosis of bones may occur due to several mechanisms not yet cleared (5–7). Femoral heads represent a specific target as reported recently in adult patients even with a bilateral involvement (2, 8). No specific information about the orthopaedic management of these cases of avascular necrosis of the femoral head (ANFH) were reported. ANFH has been treated over the decades by medical and conservative approaches, surgery with scaffolds or grafts, and hip arthroplasty (9, 10). Recently, new techniques of Tissue Engineering have been proposed with encouraging outcomes (11, 12).

The present report regards a case of an underage patient affected by MS with a bilateral ANFH secondary to pulsed administrations of steroids, managed by a conservative approach on the right hip, and by a novel surgical technique on the contralateral side.

Case report

A 17-year-old male patient affected by MS presented at the MS Centre in November 2010 for a clinical relapse. The onset of MS was on March 2009, characterized by sensitive disorders in the right lower limb. The diagnosis of relapsing remitting MS was made in April 2010, following a new relapse characterized by a right facio-brachial hemiparesis with an useless hand. He started an immune modulatory therapy with subcutaneous interferon-β1a (Rebif 22^®, Pfizer) three times/week. He remained stable until October 2010, when he complained paraesthesia and loss of strength at his arms. He underwent an intravenous administration of methylprednisolone followed by an oral corticosteroid treatment without any clinical improvement. He was then treated by intramuscular injections of dexamethasone showing a significant relief from his neurological disorders. In February 2011 he presented a new clinical relapse characterized by motor-sensitive disorders in the right arm and he was treated with intravenous corticosteroids without any results. After the infusion of intravenous immune globulins, he referred a groin pain on both hips irradiated to the anterior and medial aspect of both thighs. A radiographic study of the lumbar spine and pelvis was performed with no signs of bone alterations. A MRI of both hips was then performed. A bilateral ANFH was found: a type 2a and 2b of the right and left hip respectively was found following the classification of Steinberg (Figure 1A) (13). Given the very young age of the patient, accordingly with his parents, a conservative approach was chosen after an adequate informed consent to the treatment and for the follow-up study: restricted weightbearing, continuous use of a wheelchair, weekly administration of oral bisphosphonates and vitamin D (Fosavance^®, Merck Sharp & Dome), 40 applications of magnetotherapy, and oral therapy with Fingolimod (Gilenya^®, Novartis) were recommended. After three months, the patient underwent a new evaluation, revealing an improvement of the symptoms and of the MRI signalling in both femoral heads (Figure 1B). A passive mobilization by an automatic stationary bike was introduced. At the 6-months evaluation, the patient was free from pain, with an acceptable global muscular tone. A new MRI showed an almost complete healing of the necrosis in the right femur, while a persisting zone of necrosis was present in the contralateral hip. The patient was encouraged to begin a protocol of water-based exercises and active hip and knee movements. At the 12-months evaluation, the patient was completely asymptomatic and MRI showed the full healing of the right femur, but an unchanged signalling of the necrosis on the left side (Figure 1C). The parents and the patient decided to delay the proposed surgical procedure. Thus, the use of two crutches with a full weight bearing on the healed leg and without weight bearing on the contralateral side was proposed, combined with physical therapy in water pool and oral bisphosphonates. At two years from the diagnosis of ANFH, given the persistence of the necrosis at the left femur and the poor level of quality of life, the patient and his parents decided to undergo a surgical treatment. After an adequate consent to the surgery, a novel mini-invasive management was proposed, consisting in a forage filled by a biological composite (heterologous bone chips mixed with a concentrate of autologous mesenchymal cells obtained by a centrifugation of bone marrow harvested by the ipsilateral anterior iliac crest) and a new generation resorbable bioceramic as described previously (12). Surgery was conducted in general anaesthesia, and with a preoperative dose of Ceftriaxone 2gr. The day after surgery the patient was discharged with prescription of protected weightbearing by the use of crutches. A clinical and radiologic study was performed to check the evolution of the healing and initial resorption of the bioceramic (Figure 2A). The subject did not refer any pain or other limitations after three months postoperatively. A protocol of physical therapy in water pool was prescribed with a partial weight-bearing. Six-months postoperatively a full weightbearing was allowed. Two years after surgery, the patient is happy and asymptomatic. X-rays show an almost complete resorption of the bioceramic with a non progressive small zone of necrosis (Figure 2B). No recurrence of neurologic relapses have been referred by continuing the neurologic treatment.

Figure 1.

(A) A MRI showing a bilateral ANFH (2a type and 2b type of the right and left side respectively) referring to the classification of Steinberg. (B) A new MRI at three months after the conservative management, showing improvement of the signalling in both femoral heads. (C) A new MRI showing the full healing of the right femur, but a non progressive subchondral crescent necrosis on the left side.

Figure 2.

(A) A radiologic study showing the healing of the initial resorption of the bioceramic substituted by bone. (B) X-rays showing an almost complete resorption of the bioceramic with a full healing of the upper femur.

Discussion

Pulsed corticosteroid doses are generally effective for relapses in MS (1–3): however, they are not free from complications, as ANFH (2, 4, 5, 7–9). As reported in few cases in literature, adult MS patients affected by ANFH after intravenous corticosteroids often require a surgical procedure (6, 8, 9): nonetheless, no specific description of the surgical treatment has been reported. Historically, the failure of a conservative management of an ANFH have conducted surgeons to propose a hip arthroplasty, even in young subjects (9, 10). In the present case, an underage male patient presented an acute bilateral ANFH successfully managed by a conservative treatment in his right hip, and by a mini-invasive surgical procedure in the contralateral side.

MS patients undergoing pulsed corticosteroids therapies should be carefully selected and evaluated for a potential ANFH. Early conservative treatments should be addressed, in order to avoid open surgery in case of failure.