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

Heterotopic ossification following hip arthroplasty: a comparative radiographic study about its development with the use of three different kinds of implants

Background

Our purpose was to record the incidence of heterotopic ossification (HO) following hip replacement by different variables to identify patient groups that are likely to develop HO in the absence of a prophylactic protocol.

Methods

Radiographically, we studied 651 patients having undergone hip joint replacement, evaluating three kinds of implants: ceramic-ceramic-coupled total hip replacement (THR), TriboFit^® with polycarbonate urethane-ceramic coupling and endoprosthesis. Each patient was analysed for HO development by age, gender, diagnosis, presence of previous ossifications, surgical approach and kind of implant. Within the population that developed HO, data were assessed for correlation with severity of ossification graded according to Brooker classification.

Results

The overall incidence of HOs was 59.91 %. The factors increasing their incidence in the univariate analysis were as follows: lower age of the patients with HO (mean 77.6 years, p = 0.0018) than those subjects who did not develop HO (mean 80.2 years); male gender (64.4 %, p = 0.1011); diagnosis of coxarthrosis (72.7 %, p = 0.0001) compared to femur neck fracture (55.9 %, p = 0.0001); presence of previous HO (76.2 %, p = 0.0260); lateral approach (65.5 %) as opposed to anterior-lateral approach (55.6 %, p = 0.0163); and ceramic-ceramic THR (68.1 %) and TriboFit^® (67.0 %) compared to endoprosthesis (51.3 %, p = 0.0001).

During multivariate analysis, the presence of HO after previous hip surgery (p = 0.0324) and the kind of implant (p = 0.0004) showed to be independent risk factors for the development of HO. Analysing the population that developed HO, we found that the severity of ossification by Brooker classification was influenced by gender (p = 0.0478) and kind of implant (p = 0.0093).

Conclusions

In agreement with the literature, our radiographic study confirms the following risk factors of HO development in absence of any prophylactic treatment: male gender, diagnosis of coxarthrosis compared to femur neck fracture, previous HO, surgical approach and kind of implant. In particular, Hardinge-Bauer and Watson-Jones surgical approaches, characterized by a wide exposure of the coxofemoral joint, and ceramic-ceramic THR and TriboFit^® implants significantly increase the development of HO.

Prophylaxis of heterotopic ossification - an updated review

Heterotopic ossification (HO) is defined as the process by which trabecular bone forms outside of the skeletal structure, occupying space in soft tissue where it does not normally exist. The current popular prophylactic treatment modalities include non-steroidal anti-inflammatory drugs (NSAIDs) and radiation therapy, although the literature remains inconclusive as to which is superior. Additionally, both treatments can lead to adverse effects to the patient. Recently there have been several studies attempting to identify new aspects of the etiology of heterotopic bone formation and introduce new prophylactic modalities with increased efficacy and fewer side effects. For this review, we selectively retrieved articles from Medline published from 1958–2008 on the prophylaxis of HO with the aim of assisting readers in quickly grasping the current status of research and clinical aspects of HO prophylaxis.

Electromagnetic field and osteogenesis

<zakljucak> Poslednjih 50 godina postignuti su odlicni rezultati primenom elektrobioloske stimulacije osteogeneze. Precizno objasnjenje mehanizma dejstva EMP jos uvek nije dato, sto je jedan od razloga razlicitih pristupa i rezultata lecenja prema iskustvima klinicara i eksperimentnih studija. Uzimajuci u obzir studije sa dobrim bioloskim protokolom, preciznom dozimetrijom i definisanim eksperimentnim uslovima, stimulacija osteogeneze EMP ostace aktuelna i u buducnosti.