Case report of isolated lesser trochanter avulsion fracture

INTRODUCTION

Avulsion injuries of the lesser trochanter apophysis are relatively uncommon but predominantly occur in adolescent male athletes. It has been reported in the literature that isolated lesser trochanter avulsion fractures account for less than 1% of sports injuries.¹

Avulsion fractures of the lesser trochanter occur typically during sport due to strong muscle contraction of the iliopsoas on an apophysis with an open growth plate. The cartilaginous growth plate may be at increased risk of trauma compared to the musculotendinous units.² The primary mechanism of acute injury is a sudden forceful eccentric contraction of the iliopsoas in an attempt to accelerate or decelerate the body, typically occurring during athletic activity. An alternative mechanism of injury is a sudden excessive passive muscle stretching.³

CASE REPORT

In this case report, 15-year-old male football player presented with acute onset of pain in right groin area while playing football. He had to immediately stop the play and also difficulty in walking and running. On examination, there was tenderness over the lesser trochanter, hip flexion is restricted.

Xray showed an isolated avulsion fracture of lesser trochanter.

He was taken up for surgical fixation of the fracture on the same day.

Fergusons approach to hip. The patient is typically placed in a supine position with the hip flexed, abducted, and externally rotated. A longitudinal incision is made along the adductor longus muscle, usually 3 cm distal to the pubic tubercle.

The dissection involves separating the adductor longus and gracilis muscles, then working between the adductor brevis and adductor magnus to reach the hip joint capsule and lesser trochanter is identified

The avulsed lesser trochanter is then pulled and fixed with suture anchor and an additional cortical screw with washer along with fibrewire. The fixation and fracture reduction is confirmed under intraoperative c-arm.

Postoperatively, wound site healed well.

The patient is advised no weight bearing for 4 weeks, avoid hip flexion.

After 4 weeks, the boy started restricted weight bearing for 2 weeks, then followed by complete weight bearing. Hip flexion exercises started. Moderate exercises started 8 weeks after surgery and returned to sports activities 12 weeks after surgery. After 16 weeks post surgery he started playing football.

Xray shown fracture healing after 4 weeks of fixation and completely healed after 12 weeks of surgery.

DISCUSSION

Isolated lesser trochanter fracture is not a usual presentation of hip fracture. The first case of lesser trochanter fracture was documented in 1925, the second case reported in 1932.^4,5 It was documented that lesser trochanter fracture has an association with malignancy and suspecting of malignancy increase if the lesser trochanter fracture happens without history of trauma.⁶ Lesser trochanter fracture injury is most likely to occur as a sports-related trauma. Avulsion fractures typically occur during adolescence age.

The treatment for avulsion lesser trochanter fracture is individually tailored from being conservative with observation and follow up to surgical interventions whenever as needed. However, most of the Lesser trochanter fracture managed non-operatively with bed rest for 6-8 weeks, use of crutches, non-steroid anti-inflammatory treatment. Followed by tolerant weight bearing period for 8 weeks to 4 months. Patient can return to sport activity after 6-8 months of the time of injury

We report a case of Lesser trochanter fracture where the patient underwent surgical fixation. After 4 weeks, patient start progressive weight bearing. After 8 weeks of the injury, the patient was walking and running without limitation nor pain. After 12 weeks from the time of injury the x-ray shows complete healing of the fracture with formation of good callus. The patient returned to non-contact sports by 12 weeks and to full sport activities by 16 weeks.

Post operative Xrays taken after 12 weeks showed complete fracture healing.

CONCLUSION

Though isolated lesser trochanter fractures are rare, the management of the fracture remains perplexed. Surgical fixation has an advantage of anatomical reduction, faster healing and early mobilisation and return to sports. However, majority opts for a conservative management which delays return to normal activities especially in sports person. Hence for a high-level athlete, surgical fixation is a better choice than conservative management, as the return to sports after injury is faster in surgical fixation.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

1. 1. Thomas R, Rückauer T, Bludau F, Alexander H, Markus M, Arnold JS, et al. Avulsion fracture of the lesser trochanter in adolescents. Injury. 2018;4(7):1278-81.
2. 2. Fernbach SK, Wilkinson RH. Avulsion injuries of the pelvis and proximal femur. AJR Am J Roentgenol. 1981;137(3):581-4.
3. 3. Metzmaker JN, Pappas AM. Avulsion fractures of the pelvis. Am J Sports Med. 1985;13(5):349-58.
4. 4. Schlueter SA. Avulsion of the lesser trochanter. JBJS. 1926;8(4):766-8.
5. 5. Ynqve K. A case of isolated fracture of the lesser trochanter. Acta Orthopaedica Scandinavica. 1932;2(1-4):160-5.
6. 6. Theologis TN, Epps H, Latz K, Cole WG. Isolated fractures of the lesser trochanter in children. Injury. 1997;28(5-6):363-4.