A new study reveals that repeated foot and ankle injuries, not steroid injections, are the major contributors to osteoarthritis among retired professional footballers, highlighting the lasting toll of elite-level play on joint health.
Study: Injury and local injection and the risk of foot/ankle osteoarthritis: a case–control study in retired UK male professional footballers. Image Credit: Gts / Shutterstock
UK male footballers are prone to foot and ankle injury, but the relationship with future OA is unknown. A recent study published in the journal Rheumatology explored this association.
Introduction
Professional footballers are part of a high-contact sport with a high risk of injury, especially to the foot and ankle. The most common of these are ankle sprains and metatarsal fractures, respectively, for the ankle and foot. Football injuries mostly occur during matches, not during training sessions, because matches are competitive and involve high-speed running, jumping, and swift rotations.
Joint injury may cause trauma to the joint cartilage and surrounding tissues, causing OA of the foot and ankle. In fact, male retired professional footballers are much more likely to develop foot and ankle OA compared to the general population, as shown by the current authors in an earlier study. The odds of developing OA in this group, as well as those participating in high-contact sports, rise with joint injury. Foot and ankle OA are associated with long-term pain and disability, reducing the quality of life.
The underlying mechanisms include loss of joint stability due to acute severe joint injury, resulting in direct cartilage damage and future OA, and repetitive stress injury to the foot and ankle joints.
In footballers, such injuries are frequently treated with corticosteroids, local anesthesia, platelet-rich plasma, and hyaluronic acid. However, these strategies are largely unproven to be safe or effective in the long term. In fact, such injections may worsen the damage to the cartilage by masking it, encouraging the athlete to use the joint before it has healed.
This may promote recurrent microtrauma, chronic joint instability, and altered joint mechanics, all of which lead to OA. Thus, injections could be an additional risk factor for foot or ankle OA, even without injury. However, the authors emphasize that the apparent link may partly reflect “confounding by indication,” since injections are usually given for existing injuries rather than being independent causes of OA. This is of concern given that the current guidelines permit up to four steroid injections per year, but the study shows that retired footballers got a mean of just over four ankle corticosteroid injections per season among cases and about three among controls.
The maximum number of ankle corticosteroid injections in a single season was 22 in cases and 12 in controls. Further study is required to rule out the potential for harm from multiple corticosteroid injections into the same joint.
The authors note that injections may mask underlying damage and, combined with the physical demands of professional football, could accelerate joint deterioration; therefore, their role warrants cautious interpretation.
The current study sought to find whether injury or injection to the foot or ankle was independently associated with a higher risk of foot or ankle OA in male retired professional footballers.
About the study
The study comprised 424 retired male British footballers, of whom 63 had OA of the foot or ankle or underwent surgery after retirement. This group of cases was compared with the remaining members of the cohort who did not have either of these outcomes.
Both groups were analyzed for injury during their playing days. An injury was counted if it caused pain for most days for three months and led to absence from all training and matches during that period. Injection was counted if steroids or other medications were injected into the foot or ankle joints at any time, and the dose counts specifically related to ankle corticosteroid injections.
The adjusted odds ratios and areas under the curve (AUC) were estimated.
Results
The mean age of both cases and controls was approximately 63 years, and both had similar body mass indices (BMI). Cases played more matches than controls over their career. The risk of having had a foot or ankle injury or injection was higher in the OA cohort.
Injuries were reported in 73% of the OA cohort, compared with 42.5% of the controls. Injections had been administered to 75% and 48.4% of OA cases and controls, respectively. In particular, corticosteroid injections into the ankle were used in 57% of cases and 32% of controls, respectively.
Cases were also more likely to have nodal OA (16% vs 5.3%) and current hallux valgus (36% vs 23%), suggesting a broader predisposition to joint degeneration and foot deformity.
The odds of having had a prior injury were more than 4 times higher in the OA cohort than in controls. A history of injection among members of the OA cohort was 2.6-fold more likely than among controls. Although both variables remained in the adjusted model, the authors caution that the association with injection is likely confounded by its close link to injury rather than representing an independent causal effect.
The AUC for injury was 0.69, indicating high discrimination. This was comparable to the 0.74 with injury and injection. The AUC for all risk factors was 0.78, which is not significantly different from the injury and injection AUC. This suggests that most OA risk in professional male footballers is associated with ankle or foot injury. Injection is likely a marker for the presence of such injury rather than a distinct risk factor.
Results were similar in a subgroup restricted to ankle OA alone. A separate sensitivity analysis using GP-diagnosed OA only (excluding surgery) also produced similar estimates. In the radiographic symptomatic OA subset, the association with injection did not reach statistical significance, likely due to the smaller sample size.
Limitations
The authors note that exposures and outcomes were self-reported, which may introduce recall and selection bias. OA diagnosis was based on GP report or surgery rather than uniform imaging, and the radiographic subset was small. Findings apply specifically to male retired UK professionals and may not generalize to other populations.
Conclusions
“Injury was a major risk factor for foot or ankle OA in retired UK male professional footballers.” The same clarity was not obtained for the role of injections because the chief indication for corticosteroid injection is injury. However, professional footballers should explore the routine use of preventive approaches to reduce their risk of future foot or ankle OA.