Abstract :
[en] Introduction
Apophyseal avulsion fractures of the pelvis are common among teenage football player. Usually, they are the result of a sudden forceful concentric or eccentric contraction of the muscle attached to the apophysis. Indeed, before ossification, the apophyseal growth cartilage is the weakest point in the musculotendinous unit, making the apophysis vulnerable to injure. Athletes most commonly affected are soccer players when they tackle or shot powerful at goal and gymnasts during floor exercises which imposed sudden and excessive lengthening. Management of these fractures remains unclear. There are no guidelines between conservative and surgical approach even if most publications recommend a surgery if the diastasis exceeds 2cm and a conservative approach on the other hand.
Case report
A sixteen-year-old high-level player presented at the consultation with right ischial pain. Three months earlier, while he was sprinting, he had felt acute pain opposite the ischial tuberosity which compelled him to stop the training. He had already consulted another physician, who prescribed an X-ray which revealed an avulsion fracture of the ischial tuberosity with a maximal diastasis of 1.9 cm (Fig 1.a.). According to most publications (1,3), surgery is advisable from 2 cm of diastasis. 1.9 cm was within the range between a surgical and a conservative approach, and the conservative one was applied. An isokinetic assessment was planned. It highlighted hamstring strength imbalances with bilateral difference of 31% in concentric strength and 28% in eccentric strength in comparison with the healthy side. The mixed ratio of the hamstrings in eccentric mode at 30°/s to quadriceps in concentric mode at 240°/s was decreased to 0.8, while the lower limit in our clinical practice corresponded to 0.9. The patient was not allowed to resume competition and a rehabilitation by specific and progressive strengthening in both modes of contraction was initiated; in particular the eccentric training was initially submaximal and progressively intensified. Six weeks later, isokinetic assessment was repeated and showed significant improvement of right hamstring strength, particularly for eccentric contraction. The greatest improvement was the mixed Hecc/Qconc ratio wich had increased from 0.8 to 1.44. In regard to radiology, we observed no change since the previous X-Ray (Fig 1.b.). Intensified training on the field was allowed in order to resume competition. Less than one year after the injury, the patient restarted competition successfully with performance levels which were almost the same as before the injury.
Discussion
Many publications have discussed the surgical versus the conservative approach to treating ischiatic avulsion. Most of the published literature advocate the relevance of surgery when the diastasis exceeds 2 cm because widely displaced fractures may lead to chronic symptomatology if the treatment remains conservative. Different criteria, such as pain relief, ability to perform in sport, gross strength, activity score, X-Rays, are used by authors to demonstrate the recovery after treatment. No study accurately measured the hamstring strength before and after treatment. However, strength imbalance, especially as regards the H/Q mixed ratio, significantly increases the risk of sustaining hamstring injury in soccer player (2). For our patient, the rehabilitation enabled him to re-establish hamstring strength in six weeks with substantial improvement of eccentric assessment. The mixed Hecc/Qconc ratio increased from 0.8 to 1.44. This improvement significantly decreased the risk of recurrence of hamstring injury. Regarding X-Ray imagery, there was no evidence of healing. We advocate that radiological assessment should not be the main recovery criterion and that specific strengthening should be started even when avulsion persists on the X-Ray. Furthermore, hamstring strength should be measured accurately and objectively, e.g. by isokinetism, to be one of the main return to play criterion in association with clinical data.
