Discussion
reduced hamstring muscle strength, pain
SECONDARY, COMPLICATIONS
The objective of this study was to describe a modified surgical technique, to report clinical and functional outcome and patient satisfaction around 2 to 5 years after acute proximal hamstring muscle repair with modified surgical anchor placement, and to determine the association among these parameters in older patients. Our results confirmed our hypothesis that isokinetic muscle strength and thigh girth in the injured leg are comparable to those in the contralateral uninjured side. Contrary to our secondary hypothesis, clinical scores did not correlate with side-to-side differences in isokinetic muscle strength assessed as LSI of maximum knee flexion torque. Moreover, patient satisfaction was very high, and we observed few complications. These results suggest that the modified surgical anchor placement is a promising technique with good to excellent clinical and functional outcome.The subjective satisfaction rate in our patients was extremely high and comparable to non-modified hamstring refixation (98.8 vs. 97% [The importance of reducing the high incidence of feeling pain while sitting [We observed no measurable difference in maximum passive hip flexion between the operated and the contralateral hip, both with the knee in flexion as well as with the knee in extension. We also did not observe a difference in postoperative isokinetic maximum muscle strength between the operated and contralateral hamstring muscles. We noted two outliers in our measurements. One patient had an LSI of 135.6% corresponding to a 35.6% greater maximum flexor muscle strength on the operated side than on the contralateral side. Interestingly, this patient did not participate in any prescribed physiotherapy sessions but is a physiotherapist by training. We speculate that based on her background she was well aware of the importance of strength exercises and may have completed more rigorous training for a longer period than other patients. However, because we did not record or monitor completed physiotherapy sessions in this retrospective cross-sectional study, this remains speculation. Nonetheless, these results clearly show that hamstring muscle strength after this modified surgery may not only be comparable to but may far exceed the hamstring muscle strength of the contralateral side.The other outlier had an LSI of 71.7%, corresponding to a 28.3% lower maximum flexor muscle strength on the operated side than on the contralateral side. This result was particularly surprising because this patient was still a semi-professional track and field athlete at the time of the follow-up visit. This patient had the highest maximum flexor muscle strength with noticeably weaker hamstring muscles on the operated compared to the contralateral side. This finding was surprising also to the patient because he had not experienced any functional limitations, had fully returned to sport, and was extremely satisfied with the result of the surgery.In contrast to our study, reduced hamstring muscle strength after hamstring repair is still a common outcome. In some studies (all including younger cohorts than ours), patients were asked to subjectively estimate their hamstring muscle strength after a proximal hamstring refixation. The results showed a subjectively estimated residual strength of more or equal to 75% [The very positive outcome of this modified surgical technique is likely linked to the modified positioning of the anchors. Overall, these promising results show that the presented technique is a feasible option for surgical treatment of acute proximal hamstring ruptures in older patients. These results need to be confirmed in clinical trials involving more patients.