Diagnostic Criteria and Treatment of Atypical Ulnar Fractures Associated With Prolonged Bisphosphonate Therapy: Multicenter Case Analysis

Atypical Fracture of the Scapular Spine: A Case Report

Atypical fractures are gaining attention as a severe potential side effect of long-term treatment with bone-modifying agents (e.g., bisphosphonate and denosumab) for osteoporosis. Most atypical fractures occur in weight-bearing bones; the femur is the most frequent site. Atypical fractures occurring in non-weight-bearing bones are extremely rare. We describe an atypical fracture of the scapular spine in a 92-year-old Japanese woman with osteoporosis who had been treated with minodronate for ~7 years. Although the dislocation of the fracture site remained after conservative treatment, there was no obstacle to her daily life.

Non-vascularised corticocancellous (tricortical) iliac bone graft longer than 3 cm for non-union after failed surgical treatment

PURPOSE

We hypothesised that traditional iliac tricortical bone grafts (no vascularised) still have a reasonable role in promoting satisfactory bony healing in non-union defects of certain sizes. Here, we report the clinical/radiological outcomes through a retrospective case series.

METHODS

We screened 74 patients with definitive non-union in the long bones of the upper extremities who visited the outpatient department from 2008 to 2018. Among these patients, 25 who met our inclusion/exclusion criteria were investigated.

RESULTS

The mean age was 51.92 years, and there were 12, 9, 1, and 3 lesions of the radius, ulna, clavicle, and humerus, respectively. The tools for primary fixations were plate and intramedullary nails in 24 and 1 patients, respectively. Six patients presented with atrophic non-union. The mean period from a previous surgery was 6.84 months. The mean defective bone sizes were 1.81 and 3.50 cm pre-debridement and post-debridement, respectively. All devices had locking plates longer than the previous plate, and the graft was concurrently fixed by screws in three patients. At a mean of 15.92 weeks after the revision surgery, all patients experienced union. At the final follow-up, the clinical outcomes were satisfactory. No significant differences in clinical outcomes were found according to the lesion, type of non-union, period from the previous surgery, or harvest length of the iliac bone.

CONCLUSIONS

If the proper indications and some technical aspects are considered, a non-vascularised iliac bone graft longer than 3 cm could still be a reasonable option for treating diaphyseal non-union of the upper extremities.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Atypical fractures of the ulna: Effect of bowing of the ulna on fracture location and occurrence

INTRODUCTION

Ulnar fractures associated with long-term bisphosphonate (BPs) therapy are rare, and the nature and extent of this potential risk remains unknown. Although ulna is generally considered a "straight bone", it actually features a bow anatomically. For this reason, we speculated that ulnar bow may have a role in the development of atypical ulnar fractures (AUFs). Therefore, we compared the location and depth of ulnar bow between AUF patients and patients with atypical fractures other than the ulna. We aimed to answer: (1) whether a correlation exists between the location of the ulna bow and the location of AUFs, (2) whether the degree of ulnar bow affects the occurrence of AUFs.

HYPOTHESIS

Ulnar bowing could play a critical role in the location and occurrence of AUFs.

METHODS

We retrospectively reviewed the radiographs and medical records of 64 patients with atypical fractures admitted to our department between May 2010 to July 2020. The bow of the ulna was measured using anteroposterior (AP) and lateral radiographs. Bone angulation was described as apex of deformity, with apex lateral bow designated as AP plane bowing and apex posterior bow marked as lateral plane bowing.

RESULTS

In all patients with atypical fractures, bow locations were measured at the proximal third level to the index line in 68% of AP plane and 72% of lateral plane. In patients with AUFs, fracture sites occurred in the range of 20% to<40%, except in one patient. Fracture site versus apex lateral bow location and fracture site versus apex posterior bow location showed a statistically significant correlation coefficient of 0.81 (p<0.001) and 0.69 (p=0.003), respectively. In lateral plane, there was a significant difference between AUF patients and patients with atypical fractures other than the ulna in ulnar bow depth (p=0.014). However, no statistically significant differences were found in AP plane (p=0.110).

DISCUSSION

In AUFs, fracture site was highly correlated with ulnar bowing location, and, as the degree of apex posterior bow increased, occurrence of AUFs increased. These findings are helpful in understanding the role of bowing as the ulnar geometry in the development of AUF and early identification of the location of suspicious AUF.

LEVEL OF EVIDENCE

IV.