Introduction

Bisphosphonates have shown promising results in the management of Avascular necrosis/Osteonecrosis (AVN) of the femoral head

Aim

To evaluate the response of bisphosphonates in the non-surgical management of the early stages of AVNOFH

Patient Profile

Patients diagnosed with AVNOFH and treated with the combination of oral alendronate and I.V zoledronic acid (ZA)

Methods

• N=20 patients with AVNOFH
• Mean follow-up was 35.3 months

• Visual analogue scale (VAS) was used to assess the intensity of pain and was recorded on a verbal response scale of 0–10 (0 for no pain, 10 for the most severe pain).
• Radiological assessment was done with magnetic resonance imaging (MRI) and plain radiographs in anteroposterior and lateral views

Treatment

• Patients received a single injection of I.V ZA (5mg) at first visit followed by oral alendronate 70mg weekly (in divided doses) for 1 year
• All patients received oral daily supplements of calcium 500mg and 400 IU of vitamin D

Results

Clinical Assessment

Mean VAS pain score reduced from 7.72 at the start of therapy to 3.12 in a mean duration of 4.3 weeks

Figure 1: Reduction in VAS pain score after the start of therapy

 

• A 50% reduction in mean analgesic requirement was achieved in the first 6 weeks and it remained significantly lower as compared to baseline till the last follow-up
• Clinical outcome in terms of range of movement of the corresponding joint also improved significantly in all patients and returned back to the normal limits within 1 year.

  Radiological assessments

• MRI showed complete resolution of BME in 13 patients at 6 months and in 17 patients (94.4%) at 1 year.

  Table 1: MRI assessment of the patients till last follow-up

  MRI	Baseline	6 months	1 year	Last follow-up
  Edema present	18 (100%)	5 (27.8%)	1 (5.6%)	1 (5.6%)
  Edema absent	0 (0%)	13 (72.2%)	17 (94.4%)	17 (94.4%)

• Radiological collapse was seen in 6 out of 18 patients at a mean follow-up of 35.3 months.
• Only one out of 18 patients enrolled required surgery

Table 2: Stage-wise proportion of cases that underwent radiological progression, collapse, and surgery

Stage at the commencement of treatment	Number of affected joints at presentation	Number of joints had radiological progression	Number of joints had radiological collapse	Number of joints underwent surgery
I	7	4/7 (57.1%)	1/7 (14.3%)	0/7
II	11	5/11 (44.5%)	5/11 (44.5%)	1/11 (9.1%)
Total	18	9/18 (50%)	6/18 (33.3%)	1/18 (5.6%)

 

Safety

• No major side effects noted necessitating cessation of the therapy in any of the patients.
• Two patients reported mild gastric upset with the first dose of oral alendronate which subsequently settled down without any intervention and the other doses did not give any symptoms.

Conclusion

• The study showed that combination of yearly IV zoledronic acid and oral alendronate was well-tolerated and provided a pragmatic solution in the management of AVN other than femoral head.
• Treatment was associated with not only pain relief but also prevented long-term radiological progression, thus avoiding the need for surgery

Reference

J. Orthop. Surg. Res. 2019; 14:112