Trunnion fracture of femoral prosthesis following a large metal-on-metal uncemented total hip arthroplasty: a case report

Long-term outcomes of arthroscopic synovectomy and core decompression through multiple small bone holes for early-stage avascular necrosis of the femoral head

OBJECTIVE

This study described a minimally invasive approach for the management of early-stage avascular necrosis of the femoral head, which integrated arthroscopic intra-articular decompression and core decompression by drilling multiple small holes.

METHOD

A total of 126 patients with 185 hip avascular necrosis were included between March 2005 and January 2008, and the hips were classified, based on the Association Research Circulation Osseous staging system, into stage I (n = 43), stage II (n = 114), and stage III (n = 28). Arthroscopic intra-articular inspection and debridement, along with drilling of multiple small holes for core decompression, were performed. The Modified Harris hip score system and radiographs were used to assess the pre- and post-surgery outcomes.

RESULTS

One hundred and three patients (involving 153 hips) were followed up successfully for an average of 10.7 ± 3.4 years (range: 9-12 years). After surgery, the overall survival rate was 51.6% (79 hips), and the clinical survival rates were 79%, 72%, 52%, 32%, and 10% for patients with stage I, IIa, IIb, IIc, and III, respectively. The outcomes of patients with Association Research Circulation Osseous Stages I or IIA were better than those of other stages, while hips with a large necrotic area had poor results. This approach preserved the original biomechanical strength of the femoral head after core decompression and eliminated arthritis factors in the hip joint.

CONCLUSION

The core decompression with multiple small-size holes is an effective method for treating early-stage avascular necrosis of the femoral head, particularly in those with pathological changes in the hip joint.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Unusual Case of a Trunnion Fracture Following a Revision Hip Arthroplasty Surgery: A Brief Review of the Literature and Discussion About Causes of Failure

Trunnion fracture is an incredibly rare complication of total hip arthroplasty. Of the few reported cases, all involve implants with faulty designs, a small neck taper, or an extended neck length or offset. Most also report corrosion and an adverse soft-tissue reaction. We present a review of the literature and report on the first case, to our knowledge, of trunnion fracture in a well-fixed, cemented cobalt-chromium femoral component with a standard neck length and offset with no evidence of corrosion. This failure was likely related to scratching of the metal during previous procedures which led to crack propagation and catastrophic failure. The patient was treated with revision hip arthroplasty to an uncemented, distal-fit femoral component and insertion of new bearing surfaces.

A New Type of Periprosthetic Fracture: Is It the Time to Update the Unified Classification System?

INTRODUCTION

Increased number of primary and revision arthroplasties performed globally has led to a surge in the numbers of periprosthetic fractures. The Unified Classification System (UCS) advocated a rational approach towards the classification of periprosthetic fractures. We present here an update to the UCS with addition of new fracture pattern encountered in orthopedic practice.

METHODS

A retrospective study was conducted to review the service arthroplasty register for the cases with unique fracture pattern where the periprosthetic fracture around total hip arthroplasty was also associated with fracture of the prosthetic component. The details were retrieved from the medical record and the patients were called for a review. The radiological assessment was done with X-rays and clinical assessment with Harris Hip Scores at the latest follow-up.

RESULTS

Between 2012 and 2019, 11 patients (7 males and 4 females) were operated for peri-prosthetic fracture with a unique pattern where the fracture of femur was associated with fracture of the femoral stem as well. The mean age of the patient at the time of fracture was 56.8 years (range 42-71 years). All patients were managed with revision hip surgery. One patient died due to malignancy after 7 years of revision surgery. All the surviving patients are doing well with a mean Harris Hip Score of 86.8 at the latest follow-up of 2-9 years (mean 5.0 years).

CONCLUSION

With emergence of this new fracture pattern, it is recognition as a separate entity would help in better understanding and augmentation of the existing classification system of periprosthetic fractures.