The patient was a 14-year-old multi-sport female athlete (soccer and handball) complaining of sharp pain in the right side of the groin region, after an acute injury during a handball game. The injury caused by a sudden forceful eccentric contraction of the hamstrings, in a split movement, attempting to save a shot at goal. The pain was concentrated at the insertion of the hamstring and adductor magnus muscle, at the ischial tuberosity. Aggravating activities included walking, stair climbing, and prolonged sitting. Past medical history was unremarkable. Her general practitioner (GP) had suggested resting the injury. Due to ongoing pain and lack of functional progression, she consulted a physiotherapist in private practice, two weeks after the initial trauma. At the initial examination, her symptoms were beginning to subside, and daily function was improved, therefore conservative treatment was continued, focussing on strengthening the hip rotators, flexors, and adductors. The conclusion of the physiotherapy examination was a possible trauma to the pubic symphysis, and subsequently referred to a sports physician for further evaluation, and conservative treatment was prescribed.
Almost three months after the initial trauma, she felt a sharp pain at the initial injury site, and her functional capability decreased significantly. After a renewed specialist consultation, she was referred to MRI. The MRI revealed an avulsion fracture of the tuber ischiadicum, and consequently she was referred on to the orthopaedic sports clinic for further evaluation.
Initial examination at the sports clinic revealed that she was unable to do a 20 cm step up, run, cycle, nor walk 1.5 km. Full knee and range of motion (ROM). Distinct palpation pain at the medial side of the right Ischial tubercle. Maximum internal and external hip rotation produced sharp pain at the Ischial tubercle. Isometric knee flexion and extension strength, tested by handheld dynamometer at 60   of knee flexion, exhibiting a 50% decrease in strength, compared to the left leg. The patient's Lower Extremity Functional Scale (LEFS) score was 38/80, with a score of 80 translating to no deficits. X-ray imaging was prescribed, which confirmed the fracture seen on MRI. (Fig. 1)
There remains variability in the definitions of fracture-healing. In the study conducted by Bhandari and colleagues, surgeons felt confident of predicting non-union fractures of the pelvic rami by the fourteenth week. Pain on weight-bearing (more than three months after fracture for a delayed union and more than six months after fracture for a non-union) was endorsed as the most consistent predictor of delayed union and non-union fractures.There is as yet no consensus of the definition of non-union fractures,as several factors need to be considered in defining delayed or non-union fractures, rather than a specific timeline. This avulsion fracture may therefore be classified as a non-union.
An ultrasound-guided steroid injection (1 mL Depomedrol,3 mL Lidocaine) was administered at the insertion of the medial hamstring and adductors to the ischial tuberosity. After ten minutes, the patient could do a step-up and a full squat with no pain, however the effect subsided after two weeks. The rationale for applying the steroid injection being to eliminate the possibility of referred pain.
Nine months after injury a surgical procedure was performed with the patient in general anaesthesia and lying on her left side to induce a strong healing response at the non-union. An ultrasound guided percutaneous fenestration with K-wire 1.6 mm was repeated 6 times at the avulsion fracture. The enthesis was fenestrated 10 times, using a 1.2 mm syringe. Finally, a 5 ml local anaesthetic was injected in the area. The procedure lasted 20 min in total. The novelty of the method being the use of a K-wire in repairing a non-union, as opposed to the percutaneous needle tenotomy, in which percutaneous needle fenestration is performed at the fracture site, inducing a healing response prior to considering operative fixation of the non-union fracture. Other methods of operative interventions may include reconstructive anchor re-fixations, resection procedures of the non-united fragments, resections and osteostimulating donor site drilling and partial hamstring releases for traumatic hamstring syndrome (Fig. 2).
Rehabilitation in the primary sector was adapted by the work of Shoensee and Nilsson. Following the fenestration with K-wire, the patient was placed on crutches and was instructed to remain non-weight bearing and avoid sitting directly on her right buttock for two weeks. The rehabilitation progression was based on proposed healing rates of bone as well as by pain symptoms. Approximately six weeks' post intervention pain ceased when walking slowly. Three months postoperative she reported pain free sitting and walking distance of 500 m. Subsequent rehabilitation focused on functional movement, flexibility and strength training of abdominals, hips and lower extremity. Pain presentation and clinical findings 6 months postoperative was normal ROM and slight palpation tenderness on the ischial tubercle. Pain free squats, lunges, and slight tenderness during kicking and fast cutting movements. 17 months after the trauma, and 8 months postoperative she was cleared for a slow return to football, being pain free in running, cycling and sitting. Lower Extremity Functional Scale had improved to 77/80 as illustrated in Fig. 3.