Avulsion fracture of the lesser trochanter in a skeletally immature freestyle footballer

Isolated Avulsion Fracture of the Lesser Trochanter in an Adolescent: A Case Report and Review of the Literature

Avulsion fractures of the lesser or greater trochanter or the iliac crest are uncommon injuries in adolescents. The anterior superior iliac spine, ischium, and anterior inferior iliac spine are the most frequently affected sites. We report a rare case of a 14-year-old boy who sustained an avulsion fracture of the lesser trochanter while playing soccer. No malignancy or associated metabolic bone disease was detected. Conservative treatment was suggested, consisting of a non-weight-bearing period and analgesics. Routine follow-up was performed at one, three, and six months after the injury. Radiographs were utilized to confirm fracture healing. Full recovery and return to a pre-injury functional level were observed at six months. Within this timeframe, a thorough literature review is performed.

Isolated Avulsion Fracture of the Lesser Trochanter in Adults

BACKGROUND/AIM

Isolated fractures of the lesser trochanter (LT) of adults are rare and most of them are pathologic fractures due to an underlying malignancy. The aim of our study was to provide comprehensive information on the epidemiology, etiology, diagnostic approach, and treatment algorithm of adult LT fractures.

PATIENTS AND METHODS

We present the cases of six patients who were treated for isolated LT fractures between November 2010 and May 2019. A literature review was performed to identify adult LT fracture cases in previous studies.

RESULTS

In two patients, the LT fracture was the first manifestation of the underlying tumors. Through a literature review, we identified 32 adults with isolated LT fractures. Among these, 27 were pathologic fractures. In 11 pathologic fractures, LT avulsion was the first manifestation of malignancy.

CONCLUSION

Metastasis and the first manifestation of an underlying malignancy should be suspected in adult patients with isolated LT fracture. A stepwise approach can prevent misdiagnosis and offer rational treatment modality.

Biomechanical Comparison of Anterograde and Retrograde Lesser Trochanter Avulsion Repair

Background:

Lesser trochanter avulsions are rare injuries in adolescents. Severe cases with relevant fragment displacement can be treated surgically. However, no standard approach is available in the literature. Operative techniques are presently limited to anterograde fixations. A new retrograde approach to reduce operative difficulty and postoperative morbidity has been proposed. So far, no biomechanical comparison of these techniques is available.

Hypothesis:

Retrograde repair of the lesser trochanter with a titanium cortical button will produce superior stability under load to failure and similar displacement under cyclic loading compared with anterograde fixation with titanium suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Sixteen paired hemipelvic cadaveric specimens (mean age, 62.5 ± 10.7 years) were dissected to isolate the lesser trochanter and iliopsoas muscle. After repair of a simulated lesser trochanter avulsion, specimens were tested under cyclic loading between 10 and 125 N at 1 Hz for 1500 cycles before finally being loaded to failure at a rate of 120 mm/min in a material testing machine. Motion tracking was used to assess displacement at the superior and inferior aspects of the iliopsoas tendon under cyclic loading.

Results:

Load to failure was significantly greater for the retrograde repair compared with the anterograde repair (1075.24 ± 179.39 vs 321.85 ± 62.45 N; P = .012). Mean displacement at the superior repair aspect (retrograde vs anterograde: 3.29 ± 1.84 vs 4.39 ± 4.50 mm; P = .779) and mean displacement at the inferior aspect (3.54 ± 2.13 vs 4.22 ± 4.48 mm; P = .779) of the iliopsoas tendon did not significantly differ by the type of repair. Mode of failure was tendon tearing by the sutures for each retrograde repair and anchor pullout for each anterograde repair.

Conclusion:

Surgical repair of lesser trochanter avulsion fractures with retrograde fixation using a titanium cortical button demonstrated superior load to failure and similar displacement under cyclic loading compared with anterograde fixation using suture anchors.

Clinical Relevance:

The retrograde approach provides a biomechanically validated alternative to other surgical techniques for this injury.

Arthroscopic Reduction and Fixation of a Lesser Trochanter Avulsion Nonunion

Identifying and treating avulsion fractures of the pelvis and proximal femur in adolescent athletes has become increasingly more important as the rate of competitive sports participation has grown. The majority of these fractures can be treated conservatively, with most returning to full activity. Surgical treatment of these injuries has been traditionally indicated for >2 cm displacement, painful nonunion, symptomatic exostosis formation, or persistent pain and symptoms. Lesser trochanter avulsion injuries are extremely rare and literature outlining their surgical treatment lacking. We present our method of arthroscopic reduction and fixation of lesser trochanter avulsion nonunions.

Osteoid Osteoma at the Lesser Trochanter: A Lesson in Mimicry

A 16-year-old female soccer player presented with an eight-month-old, insidious right-hip pain. The imaging workup demonstrated a cortically based lytic lesion at the level of the lesser trochanter with surrounding sclerosis, adjacent periosteal reaction, and a small soft-tissue mass. A biopsy revealed findings related to an osteoid-forming lesion with features of nuclear atypia. The patient's pathology referral returned a diagnosis of osteoid osteoma, and she was treated with CT-guided cryoablation. She had an excellent response and returned to full activities through nearly two years of surveillance. In similar patients approaching skeletal maturity, the differential diagnosis for bone lesions involving the lesser trochanter ranges from post-traumatic to primary oncologic processes. Given the implications of a missed malignancy, vigilance is required when treating young and active patients.

[Isolated fracture of the lesser trochanter-What age-related differences are important?]

Isolated fractures of the lesser trochanter are very rare injuries. This case report describes the age-related differences based on two cases. A 13-year-old girl suffered an avulsion fracture of the lesser trochanter while sprinting. The patient received conservative treatment with pain-adapted partial weight bearing as tolerated using crutches with the goal of full weight bearing after 6 weeks. After 3 months she could return to the preinjury functional level without impairments. A 55-year-old woman also suffered an isolated fracture of the lesser trochanter, which was a pathological fracture due to a breast cancer metastasis. The cause of an isolated fracture of the lesser trochanter in adults is assumed to be the sign of an underlying malignant disease, until this has been disproven.

Avulsion fracture of the lesser trochanter in adolescents

INTRODUCTION

Avulsion fractures of the lesser trochanter in adolescents are rare. They are a result of a sudden and forceful contraction of the iliopsoas muscle. Functional results in the medium term after non-operative treatment are unknown. Therefore we aimed to report these in the present study.

MATERIALS AND METHODS

A retrospective two-center study was performed in a case series treated between 2011 and 2017. All adolescents with an acute avulsion fracture of the lesser trochanter were included. Age, gender, mechanism of injury, fracture side, amount of displacement, and therapy were analyzed. In the follow-up, the Harris Hip Score (HHS), the sports level, the power of flexion in the hip, and signs of an ischio-femoral impingement (IFI) were investigated.

RESULTS

An avulsion fracture of the lesser trochanter was diagnosed in 4 boys and 1 girl. The mean age of the patients was 13.8 years (range: 13-15 years). We observed 2 type II and 3 type III fractures. The patients received similar non-operative treatment. Follow-up was performed at a mean of 4.9 years (range: 3.5-6.2 years) after injury. All patients returned to competitive sports. The Harris Hip Score (HHS) was 100 out of 100 points. History and provocation test concerning an IFI were negative in all patients.

CONCLUSION

Our study shows excellent results with non-operative treatment in acute avulsion fractures of the lesser trochanter in a case series of five adolescents. All patients returned to competitive sports. In our opinion, acute avulsion fractures of the lesser trochanter should be treated non-operatively.