Online Supplemental Material – Case Reports
Case Reports
Patient 10
A 69-year-old woman who had experienced thigh pain for 8 months had seen previously both an orthopaedic surgeon and a neurosurgeon. She had trochanteric and epidural injections without relief. Initial radiographic films showed bilateral subtrochanteric lateral cortical thickening (Fig. 1A). MRI demonstrated marrow edema, periosteal edema, and cortical thickening (Fig. 1B). Lateral subtrochanteric cortical thickening was evident on both femurs on CT scan. She had been on alendronate for 8.5 years. She sustained a left subtrochanteric femur fracture through the previously identified lesion while getting into her car to come to her initial clinic visit with the senior author for a presumed femur tumor (Fig. 1C). The fracture united after open reduction and internal fixation with a dynamic hip screw. The contralateral painful stress fracture responded positively to prophylactic IM reconstruction nail fixation and she now is pain free.
Patient 3
A 74-year-old woman with 4 months of left thigh pain had been evaluated by her local orthopaedic surgeon with an MRI scan that showed evidence of stress fractures in both femurs (Fig. 2A). She then sustained a left femoral displaced fracture, which was treated with an IM nail before referral. She had been on alendronate for at least 3 years. Right femur radiographs demonstrated lateral cortical thickening with a subtle thin black line (Fig. 2B). Bone scan demonstrated increased activity in the right femur and in the postoperative left femur (Fig. 2C). She underwent prophylactic fixation on the right side with an IM reconstruction nail. Her fractures healed and she remained pain free.
Patient 7
A 51-year-old woman was referred to the senior author for a lesion of the right femur associated with 9 months of thigh pain. She had an antalgic gait and full ROM with pain at the limits of motion. Her complete blood count, comprehensive metabolic panel, and sedimentation rate were normal. The patient’s medication history included risedronate for 1 year, followed by alendronate for 4 years. Plain radiographs and a coronal reformatted CT scan revealed a subtrochanteric stress fracture with a transverse stress fracture line of the lateral cortex through the area of cortical thickening (Fig. 3A). Protective weight bearing with crutches was continued and surgical intervention with an IM reconstruction nail was scheduled for 3 days later. Two days after her clinical visit, the patient tripped and fell, sustaining a complete right subtrochanteric fracture (Fig. 3B). An IM reconstruction nail fixation was performed.
Seventeen months postoperatively, the patient reported a new pain in her left hip region and manifested a left-sided antalgic limp. The patient was still on alendronate, now totaling 6.5 years of bisphosphonate medication. Bisphosphonates were discontinued. An MRI revealed a stress fracture in the left subtrochanteric region, almost in the exact same location as the previous stress fracture in the right femur. Prophylactic fixation with an IM reconstruction nail was performed. One month after surgery, both femurs were pain free, but the patient had developed pain in her left lower leg. Radiographs and MRI revealed a stress fracture in the proximal tibia metaphysis. Weight-limiting nonoperative treatment was prescribed and followup continues.
Patient 13
A 72-year-old osteoporotic woman with a remote history of breast cancer complained of right midthigh pain. Lateral cortical thickening was observed in the midshaft of the femur on plain radiographs; a transverse stress fracture line was visible under magnification (Fig. 4A). Her medication history included 4 plus years of alendronate followed by zoledronic acid infusions for 2 years. A bone scan to evaluate for possible metastases revealed increased activity in the area of cortical thickening (Fig. 4B). While getting into her car after her bone scan appointment the patient’s femur fractured through the stress fracture (Fig. 4C), requiring IM reconstruction nail fixation.
Patient 14
A 65-year-old woman presented to her orthopaedic surgeon with left hip and knee pain. NSAIDs were utilized with some relief. She received a series of three injections for presumed trochanteric bursitis with some improvement. An MRI 6 months after presentation was interpreted as normal but in retrospect revealed bilateral subtrochanteric lateral cortical thickening and associated edema (Fig. 5A). Three months later, she fell and began experiencing right hip pain. Six months after the MRI, she sustained a low-energy right subtrochanteric femur fracture with the typical transverse lateral fracture line and associated cortical thickening; she underwent internal fixation with a standard doubly interlocked IM nail, complicated by postoperative pulmonary embolus. She sustained a low-energy left subtrochanteric femur fracture through the previously identified stress fracture 13 months later (25 months after her original presentation). Bisphosphonates were discontinued and the fracture was internally fixed with a reconstruction-type trochanteric femoral nail. Both fractures are uniting slowly in subsequent followup (Fig. 5B).
Legends
Fig. 1A–C (A) This AP radiograph reveals bilateral subtrochanteric lateral cortical thickening. (B) This MRI reveals intraosseous and periosteal edema and cortical thickening in the left subtrochanteric area. (C) This AP radiograph reveals the left subtrochanteric fracture she suffered while getting into her car to come for her initial clinic visit. Note the cortical thickening in the right lateral subtrochanteric proximal femur.
Fig. 2A–C (A) This MRI reveals the cortical thickening and surrounding edema in both lateral femoral cortices. It is more pronounced in the left femur. (B) This AP femoral radiograph reveals the subtle lateral cortical thickening and a subtle thin transverse black stress fracture line. (C) This bone scan reveals the activity in the untreated right stress fracture and the new activity in the left femur reflecting the fracture and femoral nail placement.
Fig. 3A–B (A) This AP radiograph reveals the lateral subtrochanteric cortical thickening and a subtle stress fracture line. (B) This AP radiograph reveals the fracture through the precursor lesion.
Fig. 4A–C (A) This AP radiographs reveals the lateral diaphyseal cortical thickening in a 72-year-old breast cancer survivor who had been on alendronate for 4 years followed by zoledronic acid infusions over a 2 year period. Note the innocuous-appearing lateral cortical thickening and the subtle transverse stress fracture line on this magnification view. (B) This bone scan reveals the increased activity in the femur at the site of the stress fracture. (C) This AP radiographs reveals the fracture she suffered while getting into her car in the hospital parking lot after her bone scan.
Fig. 5A&B (A) This T2-weighted MR image reveals left lateral cortical thickening and pericortical edema. The T1-weighted image (not shown) revealed subtle thickening of the right lateral femoral cortex at the location of the future fracture.(B) This radiograph reveals incomplete union at 29 months followup of the right femur and incomplete union at 16 months followup of the left femur .