Do clinical factors predict the return to pre-morbid function following surgical repair of ruptured Achilles tendons?

Introduction: The Achilles tendon is the most frequently ruptured tendon in the body. Various regimens for the treatment of Achilles tendon ruptures (ATR) exist with respect to operative versus conservative management and various post-operative protocols. Previous studies have compared the different post operative protocols using impairment measures; however there has been no research into the relationships between impairment measures and return to premorbid sporting activities following surgically repaired ATR. The aim of this study was to determine whether commonly used impairment measures predict patients’ ability to return to pre-morbid sports following surgically repaired ATR. Methodology: Twenty participants with surgically repaired ATR took part in a physical assessment and interview. The timing of assessments ranged from 7–40 months post surgery. Tendon length, ankle range of motion, calf circumference and calf strength were all tested using measurement techniques that are easily reproducible in a clinical setting. Interviews were conducted to determine whether return to pre-morbid levels of sport were achieved and the associated reasons. Logistic regression was used to determine which impairment variables best predicted return to pre-morbid levels of sport. Results: Eight of the 20 participants had returned to pre-morbid levels of sport, three returning to a recreational level and five returning to a competitive level of sport. Return to pre-morbid levels of sport was predicted by time since surgery and the difference in heel heights between the un-injured and injured legs when performing a double leg raise, the logistic regression equation correctly predicted the return to pre-morbid level of sport 90% of participants. For participants who had returned or had not returned to sport, the mean time since surgery was 115.3wks (SD 30.1) and 61.2wks (SD 25.1) respectively, and the mean difference in heel height between the un-injured and injured legs was 2.1 cm (SD 6.4) and 1.4 cm (SD 7.0) respectively. There was a moderate correlation (r= 0.62) between tendon length difference and calf strength difference between injured and un-injured legs, however there was no significant differences of tendon length between those who had and had not returned to sport (p= 0.4). Of the 12 participants who had not returned to sport, 83% cited fear of rupturing the tendon again as one reason for not returning. Conclusion: In the sample of patients studied return to sport following surgically repaired ATR could be predicted using clinically relevant impairment measures of time since surgery and heel height difference.