[Surgical Refixation after Proximal Hamstring Tendon Avulsion Injuries: Does the Time of Surgery Influence Functional Outcomes?].

 Proximal hamstring tendon avulsion injuries are rare. If they do occur, surgical treatment with tendon refixation is regarded as the method of choice. Surgical outcome measurements have been investigated heterogeneously and, therefore, are difficult to compare. Hence, the possibility for correlations between postoperative outcomes and surgical methods or time of surgery is limited.  Using the new, validated and injury-specific Perth Hamstring Assessment Tool (PHAT), we aimed to investigate a population of own patients in order to compare the results in relation to the time of surgery after trauma.  In this retrospective case control study, all patients who had undergone hamstring avulsion surgery between 1/2011 and 3/2016 with a follow-up period of at least six months were asked to document their subjective functional outcome using the PHAT. Depending on the time of surgery after trauma, patients and the results of their questionnaires were assigned either to an acute (< 4 weeks), a delayed (1 - 3 months) or a chronic (> 3 months) group.  In the named period, 64 patients had a hamstring refixation surgery, 57 of them could be included in the study. 39 (68 %) returned the completed PHAT questionnaire. The mean PHAT score (0 - 100 pts.) was 72.4 (SD ± 21.0). There was no significant difference between the acute and the delayed group (77.0 ± 22.0 vs. 63.4 ± 16.2; p: 0.0673), whereas a significant difference was detected between the acute and the chronic group (77.0 ± 22.0 vs. 58.3 ± 20.2; p: 0.0214).  The results of this study show that an early diagnosis and subsequent operation of a hamstring tendon avulsion injury leads to significant better functional outcomes compared with chronic procedures.