Objectives Acute Achilles tendon ruptures are common among highly active people. Recently published studies have provided increasing evidence to support non-surgical treatment. This study aimed to assess the incidence trends of surgically treated, acute Achilles tendon ruptures. Our hypothesis, based on the recent literature showing no difference in functional results between surgical and non-surgical treatment, was that the incidence of surgery would be declining.
Methods We conducted a nationwide hospital register-based study. All patients 18 years of age or older with a diagnosis of acute Achilles tendon injury, and treated with Achilles tendon repair from 1987 to 2011 in Finland were included in the study.
Results During the 25-year study period in Finland, a total of 15 252 patients received surgical treatment for an acute Achilles tendon rupture. The incidence of surgical treatment of acute Achilles tendon rupture in men was 11.1/100 000 person-years in 1987 and 20.5/100 000 person-years in 2011. The corresponding figures in women were 2.5/100 000 person-years in 1987 and 4.2/100 000 person-years in 2011. The highest rates occurred in 2008 in men and 2007 in women, and since then the decrease has been 42% in men and 55% in women.
Conclusions During the past few years, the rate of surgically treated acute Achilles tendon ruptures has declined remarkably. The findings of the present study indicate that orthopaedic surgeons have chosen more often non-surgical treatment option for acute Achilles ruptures. This can be considered as an example, how high-quality scientific evidence can lead to a rapid change in clinical practice.
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The incidence of acute Achilles tendon rupture varies between 7 and 40/100 000 person-years, depending on the study setting and age of the population.1–3 The incidence of Achilles tendon rupture has suggested to be slightly increasing, possibly because more aging adults are continuing to participate in high-demand sports.4 ,5 Incidence studies are based on hospital discharge registers, including only surgically treated Achilles tendon ruptures.1–3 Because of the non-surgical treatment option can be provided in the outpatient setting, it may not be shown on discharge registers. Thus, the exact incidence of Achilles tendon ruptures is not known.
Until the past few years, surgical repair of Achilles tendon ruptures has been favoured, mainly because of the reported higher risk of rerupture following non-surgical treatment.2 ,6 ,7 Randomised controlled trials and meta-analysis that have used cast immobilisation without early range of motion and weight-bearing show increased risk for rerupture.5 ,7–10 In 2004, a Cochrane review concluded that surgical treatment reduces the rerupture rate, but increases the rate of infection.11 In their meta-analysis,6 Khan et al concluded that surgical treatment is associated with significantly higher risk of other complications as well. These complications may be reduced by performing surgery with percutaneous surgical techniques.11
Functional ankle brace instead of a rigid cast is a relatively new treatment method that has shown to reduce the overall complication rate and seems to decrease the rate of rerupture in non-surgically treated patients.6 Therefore, recent high-quality randomised studies8 ,12–14 support the finding that application of a non-surgical protocol involving early weight-bearing and controlled range of movement instead of a rigid cast results in an outcome similar to that of surgical treatment with regard to the rate of rerupture, and avoids complications related to surgical management.
On the basis of recent increasing evidence supporting good results of non-surgical treatment of Achilles tendon ruptures, we conducted a nationwide hospital discharge register-based study to assess whether the incidence of surgically treated acute Achilles tendon ruptures has changed from January 1987 to December 2011.
Materials and methods
To determine trends in the surgical treatment of acute Achilles tendon rupture, the Finnish National Hospital Discharge Register (NHDR) was reviewed between 1987 and 2011. All patients 18 years of age or older admitted to hospitals were included. The Finnish NHDR, founded in 1967, provides an excellent database for epidemiological studies as it contains data on age, sex, domicile of the subject, length of hospital stay, primary and secondary diagnosis and operations performed during the hospital stay. The data collected by the NHDR is mandatory for all hospitals to provide, including private, public and other institutions, both inpatient and outpatient settings. The validity of the NHDR has been found to be excellent regarding both the coverage and the accuracy of the database.15–17
The main outcome variable for the study was the number of surgically treated patients with acute Achilles tendon rupture as primary or secondary diagnosis (ICD-9 codes 8450C in 1987–1995, and ICD-10 code S86.0 in 1996–2011).18 The ICD-9 procedural coding was used in Finland from 1987 to 1997 and during this period the surgical treatment codes were 9478 tendorrhaphy/reconstruction and 9505 suturation/refixation. In 1998, the coding system was changed to ICD-10 and the included operative treatment code in ICD-10 was NHL10 suturation. The data for the whole study period from 1987 to 2011 were pooled for analysis. In Finland, the approval of the institutional Review Board is not required for register studies.
To compute the incidence rates of acute Achilles tendon rupture repairs, the annual mid-population was obtained from the Official Statistics of Finland, an electronic national population register.16 The incidence of surgically treated acute Achilles tendon ruptures (per 100 000 persons) were based on the results of the entire adult population of Finland rather than cohort-based estimates, and thus, 95% CIs were not calculated. Statistical analysis was performed using PASW19.0.
During the 25-year study period in Finland, a total of 15 252 patients with acute Achilles tendon rupture were surgically treated by suturation. Acute Achilles tendon rupture surgery was more commonly performed in men than in women (figure 1). The women were older than the men (median age 41, range 18–90 in men and median age 45, range 18–91 in women). Median length of hospital stay was 1 day (range 1–36) in men and 2 days in women (range 1–35).
The incidence trends of surgical treatment for acute Achilles tendon rupture are shown in figure 1. The incidence of surgical treatment for acute Achilles tendon rupture in men was 11.1/100 000 person-years in 1987 and 20.5/100 000 person-years in 2011. The corresponding figures in women were 2.5/100 000 person-years in 1987 and 4.2/100 000 person-years in 2011. The highest rates occurred in 2008 in men (35.5/100 000 person-years) and 2007 in women (9.4/100 000 person-years). Since then the decline has occurred: the incidence figures in 2011 are 42% lower in men and 55% lower in women (figures 1 and 2) than in 2008 and 2007.
Analysis of the results by age and sex revealed that the highest incidence of surgical treatment in men occurred among 40–59-year-olds, followed by 18–39-year-olds. Interestingly, in men over 60 years of age, the incidence of surgery increased fourfold during the study period. Trends in the incidence, however, were similar in all age groups, showing an increase until 2008, followed by a decrease (figure 1).
The main finding of the present study was that the incidence of surgical treatment for acute Achilles tendon rupture declined markedly towards the end of the study period. During recent few years, it has been suggested that the clinical results are similar for surgical and non-surgical treatment of acute Achilles tendon ruptures. Based on the findings of the present study, orthopaedic surgeons in Finland seem to have changed their protocols to treat acute Achilles ruptures from surgical treatment to non-surgical treatment based on evidence from high quality randomised controlled trials. This can be considered as an example, how high-quality scientific evidence can lead to a rapid change in clinical practice, as our extensive nationwide register-based analysis proved.
As early as 2004, a Cochrane-review showed a similar functional outcome between surgical and non-surgical treatment.11 They also concluded that the rerupture rate is higher in patients treated non-surgically, while complications other than rerupture occur significantly more often in surgically treated groups.11 After the studies included in the Cochrane review, however, non-surgical treatment methods have improved and now typically consists early weight-bearing with a protected range of motion instead of a rigid cast immobilisation.19 The latest high-quality randomised controlled trials especially by Metz et al10 2008, Nilsson-Helander et al13 in 2010, Willits et al12 in 2010 and Wallace et al14 in 2011, showed that with non-surgical treatment, including functional brace and early range of motion, the rerupture rate can be decreased almost to the level of surgically treated patients, with no significant differences in clinical outcome. A recent meta-analysis confirmed previous findings that functional non-surgical treatment yields similar functional outcome and rerupture rate than surgical treatment, with a significantly lower complication rate.8 In our study, the decline in operative treatment started in 2007, a few years after the publication of the Cochrane review but before the latest high-quality randomised controlled trials. It could be assumed that implementing the new treatment policies in modern clinical practice takes few years.
Most of the published randomised controlled trials regarding acute Achilles tendon ruptures include patients under the age of 60 or 65.10 ,12 ,13 The present study, however, suggests that the surgery of the acute achilles tendon rupture is common also in persons over 60 years of age. There is not yet enough evidence to fully abandon surgical treatment of acute Achilles tendon rupture, but it has been suggested that only young athletes may benefit from surgical intervention.20 It would be interesting to know if the complication rate is related to patient age, but to our knowledge, there are no randomised controlled trials assessing functional outcome and complications in persons over 60 years. Patients over 60 years of age, however, quite often have comorbidities, which may further increase the risks of surgical treatment. Despite of the active lifestyle the patients over 60 years may have, the evidence suggestions that the non-surgical treatment should be preferred, could probably be more strictly followed in clinical practice.
Strength of the present study is that a true nationwide data was used, since medical treatment in Finland is equally available to everyone and the study population comprised the entire Finnish adult population. Therefore, the results are not limited to dedicated sports medicine centres or scientifically active hospitals. With coverage of a whole country including public, private and other hospitals, the changes in the trends of a treatment method obviously represent general opinion of all actively practicing surgeons in Finland. During the study period, no such change in diagnostics, ICD-coding or in hospital registry have occurred which could explain the trend seen. Although some Achilles tendon operations are performed as an out-patient surgery, the in-hospitalisation time is coded as 1 day up until the first 24 h, which skews the time for hospitalisation. Strength of the present study is also that in previous investigations, the coverage and accuracy of the NHDR injury codes were found to be over 90%17 covering all hospitals. A limitation of our study is that the actual incidence of all acute Achilles tendon ruptures cannot be assessed using the NHDR data alone because some of the ruptures are treated non-surgically on an outpatient basis. In addition, we do not know whether the incidence of acute Achilles tendon rupture has decreased during the study period, and had an impact on decline in the operative treatment. A recent Finnish study showed that incidence of achilles tendon ruptures may be increasing21 but to our knowledge no nationwide data exists and thus studies assessing the true incidence rates of acute Achilles tendon ruptures are needed.
In conclusion, the incidence of surgical treatment for acute Achilles tendon rupture has declined markedly in Finland during the recent years. A plausible reason for this decline could be that recent high-quality evidence suggesting similar results for surgical and non-surgical treatment for acute Achilles tendon rupture, has affected treatment policies. We expect a further decline in the incidence of surgical treatment for acute Achilles tendon rupture, based on the rapidly changing trend towards non-surgical treatment seen in this study.
What are the new findings?
In the past few years, randomised trials have provided increasing evidence to support non-surgical treatment for acute Achilles tendon ruptures. However, it is not know whether this evidence has had an effect on the incidence of surgery. On the basis of our results, the rate of surgically treated acute Achilles tendon ruptures has declined markedly. A plausible explanation is that the new evidence has indeed changed the orthopaedic praxis towards non-surgical treatment approach for treating acute Achilles ruptures.
How might it impact on clinical practice in the near future?
Although the rate of surgically treated acute Achilles tendon ruptures has declined markedly, a significant proportion of these injuries are still treated surgically. We expect a further decline in the incidence of surgical treatment for acute Achilles tendon rupture, based on the rapidly changing trend towards non-surgical treatment seen in this study.
Contributors VM has planned, conducted and reported this research with TH. AM and HPA guided them through this process. HHP and PSA took part in writing and statistical analysis. All authors have written the manuscript together and submitted the final version for publication.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
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