Introduction

Avascular necrosis of femoral head occurs due to impaired blood supply to the head of femur. It can be caused by fractures, dislocations, chronic steroid use, chronic alcohol use, coagulopathy, congenital causes and many other factors. But most common cause is Idiopathic. (1-4) The use of a non-vascularized bone graft is more attractive in treating the early stages of avascular necrosis of femoral head than vascularized graft because, it is significantly less technically demanding. (5,6)

Non-vascularized autologous bone grafting has several theoretical advantages. this method leads to the decompression of the avascular lesion and the elimination of the necrotic bone, breaking the cycle of ischemia and intraosseous hypertension in addition to providing growth factors from the graft [7].

The regenerative properties due to the presence of osteoblasts in the trabecular bone and the ability to procure a large amount of graft make the iliac crest the gold standard site of cancellous bone graft harvesting. [8,9]

core decompression can be considered an effective treatment modality in the early stages (up to stage 2b) of AVN of the femoral head [10]. Therefore, this study was conceptualized to study the effect of core decompression along with cancellous bone grafting on cases of AVN of the femoral head.

Material and method

This prospective, interventional study was conducted in Global hospital, Ujjain from jan-2022 to march-2023. We studied 20 hips having early AVN of the femoral head treated by core decompression and autologous cancellous bone grafting with a graft taken from the iliac crest.

AVN of femoral head (up to grade 2b of Ficat and Arlet classification) who met the inclusion and exclusion criteria are included in this study.

Inclusion criteria was patients with avascular necrocis of the femoral head up to stage 2b (Ficat and Arlet), patients aged between 18 and 60 years and patients giving consent for the surgical procedure and participation in the study.

Exclusion criteria was patients with previous infection of the hip Joint, neuromuscular disorder of the hip joint and severe osteoporosis

AVN stage was confirmed preoperatively using an X-ray of the pelvis with both hip joints and an MRI of both hips. A preoperative workup was done. After taking written and informed consent, patients were taken for the operation theatre.

Patients were placed on a traction table in a supine position. Sterile painting and draping were done. Subsequently, a 2-3 cm mid- lateral longitudinal incision was made over the subtrochanteric region.

There was a male predominance, with 17 out of 20 patients being male. All patients became symptomatic within the last year (range = 2-12 months). Of 20 patients, 11 presented to us within three months of developing symptoms (Table 1). Out of 20 patients, 10 were able to sit cross-legged, squat, and climb stairs without any significant problems. Four patients were not able to sit cross-legged or squat, while five patients were not able to climb stairs.

Life style modification was advised to all patients. Five patients who were alcoholics were advised to stop taking alcohol. Seven patients had a history of steroid use due to COVID-19 infection. No specific aetiology was identified in eight patients

Table 1: Age distribution, sex distribution and duration of pain (in months)

Table 2: Risk factor/ Etiology

Table 3: The mean HHS was 69.45 preoperatively and 83.55 at six months postoperatively (p ≤ 0.0003)

Table 4: Visual Analog Scale score preoperatively and at six months postoperatively. The mean VAS score was 6.3 preoperatively and 3.8 at six months postoperatively (p ≤ 0.0001)

Table 5: Complications

Overall, 30% of patients developed secondary arthritis after six months and progressed to Ficat and Arlet stage 3/4. In total, 17 patients had pain at the donor site immediately after surgery.

Figure 5: X-ray at three months of follow-up.

Figure 6: X-ray at the final follow-up.

Discussion

The blood supply of the femoral head is so tenuous that even a slight vascular injury can predispose to AVN. Hence, AVN is commonly seen in the femoral head. Studies have shown that core decompression can arrest or even reverse the process of AVN and can avoid femoral head collapse and its sequelae. Core decompression can preserve the femoral head at an early stage of the pathology [4,5].

Steinberg et al. reported that 92% of patients who underwent non-operative management had femoral head collapse at the end of two years. They found that patients with early- stage AVN who had undergone core decompression and cancellous bone graft had about a 70% success rate [11]. Core biopsies were performed in the early sixties in a small number of patients with AVN of the femoral head to examine the pathological changes. The increased intraosseous pressure was relieved by core decompression, thereby providing pain relief to the patient.

According to Steinberg, treating early AVN of the femoral head with core decompression and cancellous bone grafting is a safe and efficient method [12]. We studied 20 hips having AVN of the femoral head treated by core decompression and autologous cancellous bone grafting with a graft taken from the iliac crest. In a study, Babhulkar [13 ] treated 32 patients with AVN of the femoral head by core decompression and iliac crest grafting and reported pain relief in all patients. Similar results were found in our studies as well.

Conclusion

Our study suggests that core decompression with autologous cancellous bone grafting might not reverse AVN progression but can delay the progression of AVN, avoid collapse, reduce pain, and provide improvement in functional outcomes at least in the short term. The study had a relatively shorter follow-up period of six months. Probably, a longer follow-up is needed for evaluating long-term functional outcomes. A shorter follow-up period was because of time constraints. Another limitation was the small sample size as overestimation of treatment effect is more likely in a small sample compared to a large sample.

Patient compliance was also a limitation of our study. The limitation of the surgical method was that it could only be done in the early stage of the disease (Ficat and Arlet stages I and II) and did not have any significant outcomes, if done in the advanced stages of the disease (Ficat and Arlet stages III and IV). Other surgical treatments such as muscle pedicle bone grafting and vascular grafting were not done due to time, technical, and financial constraints. Core decompression with cancellous bone grafting is a promising procedure in stages 1 and 2 as it reduces the symptoms in the majority of cases and provides improvement in functional outcomes.

References