Return to sport after criteria-based rehabilitation of acute adductor injuries in male athletes: a prospective cohort study

Key points

1. 01MRI grade 0-2 injuries: median 13 days to pain-free, 18 days to full team training
2. 02MRI grade 3 (complete tear/avulsion): median 55 days to pain-free, 78 days to full team training
3. 03Overall 1-year reinjury rate was 8% - lower than published epidemiological rates of 18-27%
4. 04Athletes who met the clinically pain-free criteria had a significantly lower reinjury rate (5% vs 21% at 12 months)
5. 0575% of athletes reached the pain-free milestone and 93% eventually returned to full team training

How it was conducted

Design

Prospective single-center cohort study, level of evidence 2

Participants

81 male adult athletes (ages 18-40) with acute adductor injury presenting within 7 days of onset; 58% soccer, 22% futsal

Setting

Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; 4 sports seasons (August 2013 to June 2017)

Intervention

Supervised criteria-based exercise rehabilitation program with 9 groin exercises, progressive running and change-of-direction drills, and controlled sports training phase

Injury grading

MRI graded 0 (no acute finding) to 3 (complete tear/avulsion); grade 0: n=14, grade 1: n=20, grade 2: n=30, grade 3: n=17

Primary outcomes

Days to 3 RTS milestones: (1) clinically pain-free, (2) completion of controlled sports training, (3) return to full team training; reinjury rate at 2, 6, and 12 months

What they found

• MRI grade 0-2 injuries: median 13 days (IQR 11-21) to pain-free, 17 days (IQR 15-27) to controlled sports training, 18 days (IQR 14-27) to full team training
• MRI grade 3 injuries: median 55 days (IQR 31-75) to pain-free, 68 days (IQR 51-84) to controlled sports training, 78 days (IQR 68-98) to full team training
• Grade 3 vs grade 0-2 differences were statistically significant at all milestones (P < .001), with large standardized effect sizes of 0.674, 0.715, and 0.698 respectively
• No statistically significant differences in RTS duration between grade 0, 1, and 2 injuries at any milestone (all P > .05)
• Overall 1-year reinjury rate: 8% (6 of 72 athletes)
• Reinjury rate at 12 months: 5% in clinically pain-free group vs 21% in not pain-free group (phi = -0.233, P = .048)
• Reinjury rate at 0-2 months: 3% in pain-free group vs 21% in not pain-free group (phi = -0.282, P = .015)
• Completion of controlled sports training (milestone 2) was not significantly associated with lower reinjury rate at 12 months (6% vs 13%, phi = -0.107, P = .366)
• Rehabilitation attendance for athletes completing the protocol: 89% (IQR 76%-100%)
• At protocol completion, mean limb symmetry indices for strength and ROM were approximately 97-101%, except supine eccentric adduction in grade 3 injuries (80% +/- 17%)
• HAGOS subscale scores at completion of controlled sports training were high across all domains (median 96-100 out of 100)

Limitations

• No control group, so it is uncertain whether the specific exercise program influenced RTS duration compared with other approaches
• Small sample size, particularly limiting the reliability of reinjury rate estimates
• Subsequent injuries were registered via telephone calls without standardized clinical or imaging examination
• All athletes were male and 80% participated in football codes (soccer and futsal), limiting generalizability to other sports, competition levels, and female athletes

Why it matters

For patients

Athletes with a groin adductor strain can expect to return to team training in about 2-3 weeks for most injuries, or up to 3 months for a complete tear, when following a structured criteria-based program.

For clinicians

Using specific clinical criteria (pain-free on palpation, resistance, stretch, and sprint before clearing for return) appears to reduce reinjury risk significantly compared to returning athletes who have not met those criteria.

For readers

This study provides the first criteria-based RTS timeline benchmarks for acute adductor injuries and supports the use of formal pain-free criteria as a gating requirement before sport resumption.