Heterotopic ossification following severe radial head fractures: Clinical outcome and associated factors

Abstract

Objectives: This study aimed to evaluate clinical outcome, prevalence, severity, location, range of motion, and possible risk factors of heterotopic ossification (HO) following severe radial head fractures.

Patients and methods: In this retrospective study, 73 patients (40 males, 33 females; mean age: 51.4±15 years; range, 20 to 82 years) with Mason-Johnston type 3 and 4 radial head fractures were surgically treated with osteosynthesis or radial head arthroplasty (RHA) between September 2014 and February 2021. Fifty-one were examined in person, while 22 participated via questionnaire. The clinical outcome was assessed by the range of motion, the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and the 36-item Short-Form Health Survey (SF-36). Operative and postoperative details and the intake of HO prophylaxis were reviewed. Heterotopic ossification severity and location was evaluated on radiographs.

Results: Heterotopic ossification was present in 52.1%, while in 31.5% of all participants, RHA was needed. Overall, 46.6% received additional ligamental refixation. The mean time to surgery was 8.9±11.9 days, and the mean DASH was 13.7±16.6. In patients treated with osteosynthesis, more HO was observed for Mason-Johnston type 4 injuries compared to Mason-Johnston type 3 injuries (p=0.028). Overall, more HO was present in Mason-Johnston type 4 injuries (63.6%) compared to Mason-Johnston type 3 injuries (42.5%), without reaching significance (p=0.072). No significant association between HO and time to surgery (p=0.716), implantation of RHA (p=0.127), or ligamental refixation (p=0.121) was detected. Regardless of intake of HO prophylaxis, nearly the same amount of HO (51.7% vs. 53.8%) was present. No differences between the HO and non-HO group were detected in the DASH (p=0.553) and the SF-36 (physical component, p=0.728; mental component, p=0.275).

Conclusion: Over 50% surgically treated radial head fractures classified as Mason-Johnston types 3 and 4 developed HO, while more severe injuries led to a higher prevalence of HO. No increased rates of HO were determined for delayed surgery, surgical treatment methods, and use of HO prophylaxis. Therefore, regular HO prophylaxis might not be needed. Additionally, no significant differences in functional scores and quality of life were detected between patients with and without HO.

Figure 1. Flow chart of the cohort from inclusion to the final study population.

Figure 2. Heterotopic ossification classification according to Leyder et al.[20] (a) ulnar HO smaller than the radial head diameter = HO Grade 1u (b) anterior HO bigger than the radial head diameter = HO Grade 2a.: HO: Heterotopic ossification.

Figure 3. (a-d) Box plots of the ROM divided into HO groups according to the classification of Leyder et al.[20]: absent HO, HO severity of 1, and HO severity of 2.: ROM: Range of motion; HO: Heterotopic ossification.