Return to Play and Recurrence After Calf Muscle Strain Injuries in Elite Australian Football Players

Abstract

Background: Calf muscle strain injuries (CMSI) are prevalent in sport, but information about factors associated with time to return to play (RTP) and recurrence is limited. Purpose: To determine whether clinical and magnetic resonance imaging (MRI) data are associated with RTP and recurrence after CMSI. Study Design: Case-control study; Level of evidence, 3. Methods: Data of 149 CMSI reported to the Soft Tissue injury Registry of the Australian Football League were explored to evaluate the impact of clinical data and index injury MRI findings on RTP and recurrence. Clinical data included age, previous injury history, ethnicity, and the mechanism of injury. Results: Irrespective of the anatomical location, players with CMSI with severe aponeurotic disruption (AD) took longer to RTP than players with CMSI with no AD: 31.3 ± 12.6 days vs 19.4 ± 10.8 days (mean ± SD; P = .003). A running-related mechanism of injury was associated with a longer RTP period for CMSI overall (adjusted hazard ratio [AHR], 0.59; P = .02). The presence of AD was associated with a longer RTP period for soleus injuries (AHR, 0.6; P = .025). Early recurrence (ie, ≤2 months of the index injury) was associated with older age (AHR, 1.3; P = .001) and a history of ankle injury (AHR, 3.9; P = .032). Older age (AHR, 1.1; P = .013) and a history of CMSI (AHR, 6.7; P = .002) increased the risk of recurrence within 2 seasons. The index injury MRI findings were not associated with risk of recurrence. Conclusion: A running-related mechanism of injury and the presence of AD on MRI were associated with a longer RTP period. Clinical rather than MRI data best indicate the risk of recurrent CMSI.

The Assessment, Management and Prevention of Calf Muscle Strain Injuries: A Qualitative Study of the Practices and Perspectives of 20 Expert Sports Clinicians

“…Experts did not find simply extending the rehabilitation period to be an effective safeguard to avoid recurrence. In support of this point, a recent study found no association between the precise length of the rehabilitation period and the risk of recurrent CMSI [ 31 ]. Delaying RTP may also increase the risk of a subsequent injury if it compromises exposure to high-load activities [ 52 , 53 ].…”

“…Investigations into muscle strains have focused on the predictive value of clinical and radiological factors on the time taken to RTP and recurrence, showing mixed evidence across the hamstrings [ 60 – 62 ], adductors [ 63 – 65 ] and calf [ 7 , 66 , 67 ]. Baseline clinical and radiological information may together help to estimate recovery after CMSI, whereas clinical factors best inform the risk of recurrence [ 7 , 8 , 31 ]. This information may help guide the rate of functional progression and ensure subsequent injury risk is minimised.…”

“…Delaying RTP may also increase the risk of a subsequent injury if it compromises exposure to high-load activities [ 52 , 53 ]. Other factors such as older age and injury history [ 31 ], deficits in strength and plyometric function, and exposure history, may be more influential on risk of recurrence. In particular, susceptible athletes were perceived to have persisting impairments that reduce tolerance to high-load activities such as running [ 76 ].…”

“…Identifying persisting impairments [ 60 , 78 , 79 ] may be a way to determine ‘at-risk’ athletes and inform immediate decisions relating to readiness to RTP, as well as exercise selection to address these modifiable impairments [ 80 ] or improve structural integrity at locations vulnerable to CMSI [ 81 , 82 ]. Monitoring athlete status rigorously is important because > 50% of recurrent CMSI occur during rehabilitation or soon after RTP [ 7 , 31 ].…”

“…Further investigation is warranted given that failed management (i.e. recurrent CMSI) results in a two-week longer average time to RTP [ 7 ] and the risk of subsequent CMSI is elevated for months [ 8 , 31 ]. The aim of this study was to evaluate current practices and perspectives of a select group of international experts regarding the assessment, management and prevention of CMSI.…”