Heterotopic ossification in primary total hip arthroplasty: risk factor analysis

Abstract

Background Aim is to identify if age, sex, type of posterolateral approach (mini vs standard), surgical time and time from surgery to drainage removal were independent risk factors for heterotopic ossifications after total hip arthroplasty. Materials and methods Patients who underwent a THA with posterolateral approach during a 15 years period were included. The exclusion criteria were absence of X-rays follow-up or HO prophylaxis protocol adoption. The following data were collected: age, sex, type of approach (classical/minimal-invasive), surgical time, time from surgery to drainage removal. Two orthopedic surgeons independently reviewed the 2 years follow-up X-rays and classified the HO according to Brooker classification. Severe HO was defined if HO were classified as major than grade 2. Correlation between severe HO and risk factor has been tested with multivariable analysis. Results About 1225 patients were included: mean age of 63.8 years, 504 were men. HO were found in 67.6%. Men showed higher severe HO rate than woman (44.1% vs 29.1%, p = 0.001). Patients older than 65 years showed higher severe HO rate (30.3% vs 39.9%, p = 0.002). Standard posterolateral approach was performed in 75.4% and severe HO rate was 32.8% versus 27.1% in those treated with the minimally invasive approach (p = 0.067). In 75.6% of cases surgery lasted less than 90 min and this group showed a severe HO rate in 29.1%, while patient with longer surgical time showed a rate of 35.7% (p = 0.033). In 47.4% of patients, the drainage was removed in the first post-operative day, in this group severe HO rate was significantly lower than the others: 24.8 versus 36.2% (p = 0.001). Discussion Male sex, age older than 65 years, surgical time longer than 90 min and delayed drainage removal are risk factors for severe HO. Patients with one or more of those risk factors should be identified as good candidates for HO prophylaxis.

Role of aspirin in the prevention of heterotopic ossification following total hip replacement: a systematic review and meta‐analysis

“…According to prior studies, potential risk factors for HO formation after THA include male gender, increased age, ethnicity, underlying osteoporosis, cemented prosthesis, bilateral THA procedures, ankylosing spondylitis, hip ankyloses and previous history of HO. 2,4,26,30 No existing treatment modalities will halt the progression of HO once it has begun to form. 31 Existence of post-arthroplasty pain and limited functional improvement increases with the degree of HO.…”

Heterotopic Ossification After Modern Total Hip Arthroplasty: Predisposing Factors, Prophylaxis, and Surgical Treatment

“…It is generally accepted that the prevalence and extent of HO can be reduced with perioperative prophylaxis. 16 The two types of prophylaxis are oral nonsteroidal anti-inflammatory drugs (NSAIDs) and local irradiation of the hip. 1,5,6,16 One study recommended that pharmacologic prophylaxis for HO should be started within the first 48 hours and no later than five days postoperatively.…”

“…Any heterotopic bone formation with the posterolateral approach has been reported from 22% to 32%, at followup times of 6 to 24 months postoperatively. 5,[14][15][16] With the direct anterior approach (DAA), the prevalence has been reported from 24% to 42% at follow-up times of 6 to 24 months postoperatively. 2,15,17 With the different socalled anterior-based muscle sparing approaches, one study reported a prevalence of 36% with a minimum follow-up of 9 months.…”

“…5,6,19 In another study, a patient older than 65 years, male sex, duration of surgery longer than 90 minutes, and prolonged wound drainage were reported as specific risk factors. 16 There is indirect evidence that pharmacologic prophylaxis (with warfarin or low-molecular-weight heparin) compared with aspirin prophylaxis for venous thromboembolism may be associated with a greater frequency and severity of HO, and this was assumed related to excessive bleeding in the hip muscles and capsule. [20][21][22] Patients having THA for the diagnosis of ankylosing spondylitis or bilateral hypertrophic osteoarthritis have historically been reported to have an increased risk of HO.…”

“…16 The two types of prophylaxis are oral nonsteroidal anti-inflammatory drugs (NSAIDs) and local irradiation of the hip. 1,5,6,16 One study recommended that pharmacologic prophylaxis for HO should be started within the first 48 hours and no later than five days postoperatively. 32 The NSAIDs used for prophylaxis are either selective or nonselective inhibitors of the cyclo-oxygenase enzyme.…”