Hip Replacement

Indian J Orthop. 2009 Jan;43(1):17-21.

Biophysical stimulation in osteonecrosis of the femoral head.

Leo M, Milena F, Ruggero C, Stefania S, Giancarlo T.


Osteonecrosis of the femoral head is the endpoint of a disease process that results from insufficient blood flow and bone-tissue necrosis, leading to joint instability, collapse of the femoral head, arthritis of the joint, and total hip replacement. Pain is the most frequent clinical symptom. Both bone tissue and cartilage suffer when osteonecrosis of the femoral head develops. Stimulation with pulsed electromagnetic fields (PEMFs) has been shown to be useful for enhancing bone repair and for exerting a chondroprotective effect on articular cartilage. Two Italian studies on the treatment of avascular necrosis of the femoral head with PEMFs were presented in this review. In the first study, 68 patients suffering from avascular necrosis of the femoral head were treated with PEMFs in combination with core decompression and autologous bone grafts. The second one is a retrospective analysis of the results of treatment with PEMFs of 76 hips in 66 patients with osteonecrosis of the femoral head. In both studies clinical information and diagnostic imaging were collected at the beginning of the treatment and at the time of follow up. Statistical analysis was performed using chi-square test. Both authors hypothesize that the short-term effect of PEMF stimulation may be to protect the articular cartilage from the catabolic effect of inflammation and subchondral bone-marrow edema. The long-term effect of PEMF stimulation may be to promote osteogenic activity at the necrotic area and prevent trabecular fracture and subchondral bone collapse. PEMF stimulation represents an important therapeutic opportunity to resolve the Ficat stage-I or II disease or at least to delay the time until joint replacement becomes necessary.

Bioelectromagnetics. 2009 Sep;30(6):423-30.

Effects of pulsed electromagnetic stimulation on patients undergoing hip revision prostheses: a randomized prospective double-blind study.

Dallari D, Fini M, Giavaresi G, Del Piccolo N, Stagni C, Amendola L, Rani N, Gnudi S, Giardino R.

VII Division of Orthopaedic and Traumatology, Rizzoli Orthopaedic Institute, Bologna, Italy.


In this prospective, randomized, double-blind study, the effect of Pulsed Electromagnetic Fields (PEMFs) was investigated in 30 subjects undergoing hip revision using the Wagner SL stem. The subjects were treated for 6 h/day up to 90 days after revision. Study end points were assessed clinically by the functional scale of Merle D’Aubigné and instrumentally by Dual-Energy X-ray Absorptiometry (DXA) at the Gruen zones. Subject improvement according to Merle D’Aubigné scale was higher (P < 0.05) in subjects undergoing active stimulation compared to placebo. In analyzing the DXA findings, we subtracted for each area the postoperative bone mineral density (BMD) values from those measured at 90 days and we considered all results above 3.5% as responders. There were no significant differences in the average BMD values at each Gruen zone between the two groups both postoperatively and at 90 days investigation. In Gruen zones 5 and 6, corresponding to the medial cortex, we observed six responders (40%) in both areas in the control group, while in the stimulated group we observed 14 (93%) and 10 (66%) responders, respectively (both P < 0.05). This study showed that PEMF treatment aids clinical recovery and bone stock restoration.

Vojnosanit Pregl. 2006 Sep;63(9):807-11.

Methods of the physical medicine therapy in prevention of heterotopic ossification after total hip arthroplasty.

[Article in Serbian]

Koci? M, Lazovi? M, Kojovi? Z, Mitkovi? M, Milenkovi? S, Ciri? T.

Klinicki centar Nis, Klinika za fizikalnu medicinu, rehabilitaciju i protetiku, Srbija. lakidika@bankerinter.net


BACKGROUND/AIM: In the prevention of periarticular heterotopic ossification (HO), a common complication after total hip arthroplasty (THA), nonsteroidal antiinflammatory drugs (NSAID) and irradiation are used. Some theories presume that local hypoxia of the soft tissue causes HO. The aim of this study was to investigate if the early use of pulsed electromagnetic fields (PEMF) could prevent this ossification since it accelerates the circulation and oxigenation of soft tissue.

METHODS: The study included three groups of the patients with primary THA. The group C consisted of 66 patients/79 hips who had only kinesitherapy in postoperative rehabilitation. The group B consisted of 117 patients/131 hips who had PEMF and interferential current (IC) which, on average, started on the 14th day after the surgery combined with the standard kinesitherapy. The group A consisted of 117 patients/131 hips who had PEMF from the third postoperative day and IC from, on average, the 14th postoperative day with the standard kinesitherapy. The classification of HO was done on a standard AP roentgenograms of the hips, taken at least one year after the surgery.

RESULTS: The overall HO was seen in 50.63% of the group C patients, in 43.51% of the B group and in 16.67% of the group A. Severe HO (III and IV class according to Brooker) was seen in 26.58% of the group C patients and in 6.10% of the group B, but none in the group A.

CONCLUSION: According to the obtained results an early treatment with PEMF could prevent severe HO and reduce the overall HO.

Clin Rheumatol. 1996 Jul;15(4):325-8.

Therapy with pulsed electromagnetic fields in aseptic loosening of total hip protheses: a prospective study.

Konrad K, Sevcic K, Földes K, Piroska E, Molnár E.

Országos Reumatologiai és Fizioterápiás Intézet, Budapes, Hungary.


Aseptic loosening is the most common problem of hip arthroplasties, limiting its long term success. We report a study of pulsed electromagnetic field (PEMF) treatment in 24 patients with this complication. At the end of treatment, six months and one year later, pain and hip movements improved significantly with the exception of flexion and extension. There was significant improvement in both isotope scans and ultrasonography, but not in plain X-ray. The decreased pain and improved function suggest that PEMF is effective in improving symptoms of patients with loose hip replacement. No improvement, however, can be expected in patients with severe pain due to gross loosening.