Fracture of Contemporary Femoral Stems: Common Trends in This Rare Occurrence.

BACKGROUND: Fracture of contemporary femoral stems is a rare occurrence in total hip arthroplasty. A knowledge gap remains regarding manufacturing, patient, and surgeon factors that may contribute to the increased risk of this complication. METHODS: We analyzed 13 contemporary fractured porous-coated femoral stems of various designs to determine cause and contributing factors of mechanical failure. Cases included 12 men and 1 woman who had an average age at index surgery of 53 years (range, 34 to 76 years). There were 10 of 13 patients who had a body mass index more than 30 (obese); 3 of the 10 had a body mass index more than 40. The mean time to fracture was 7.6 years (range, 7 months to 12 years). RESULTS: There were 4 titanium alloy stems that fractured an average of 3.6 years postrevision surgery for head/cup exchange and had associated iatrogenic mechanical and electrocautery damage to the femoral neck at fracture initiation sites. There were 6 modular stems that failed at the stem-sleeve or stem-neck interfaces with evidence of fretting corrosion. For 2 stem-neck fractures, mismatched head/stem combinations from different manufacturers resulted in untested mechanical offsets and loading. There were 2 proximal neck fractures and 1 mid-shaft fracture of coated cobalt-chromium alloy stems that occurred in 3 obese men. The neck fractures (10 to 12 years) were well-fixed stems. Lack of proximal fixation contributed to the mid-shaft fracture (7 months). CONCLUSION: While rare, femoral stem fractures pose catastrophic outcomes in primary and revision total hip arthroplasty. Manufacturing, patient, and surgical factors contributing to stem failures were identified, including patient obesity, heat-treatment reduction of mechanical properties, iatrogenic implant damage, and mixing of different vendor stems and heads.

Posterior Approach Total Hip Arthroplasty Utilizing a Monoblock Dual-Mobility Construct Without Posterior Hip Precautions: A Series of 580 Hips With One Dislocation.

BACKGROUND: Instability remains a devastating complication following total hip arthroplasty. Here we describe a mini-posterior approach with a monoblock dual-mobility implant without "traditional posterior hip precautions" yielding excellent results. METHODS: There were 580 consecutive hips in 575 patients who underwent total hip arthroplasty utilizing a monoblock dual-mobility implant and a mini-posterior approach. With this technique, the acetabular component positioning does not rely on tradition intra-operative radiographic abduction and anteversion goals but rather uses patient-specific anatomic landmarks (anterior acetabular rim and, when visible, the transverse acetabular ligament) to set cup position; stability is assessed with a significant, dynamic intra-operative test of range of motion. Patients' mean age was 64 years (range, 21 to 94), and 53.7% were women. RESULTS: Mean abduction was 48.4° (range, 29° to 68°) and mean anteversion was 24.7° (range, -1° to 51°). Patient Reported Outcomes Measurement Information System scores improved in every measured domain from preoperative to final postoperative visit. There were seven (1.2%) patients who required reoperation, with mean time to reoperation of 1.3 months (range, one to 176 days). Only one patient (0.2%) who had a preoperative history of spinal cord injury and Charcot arthropathy dislocated. CONCLUSION: A posterior approach hip surgeon may want to consider using a monoblock dual-mobility construct and avoidance of traditional posterior hip precautions to achieve early hip stability with an extremely low dislocation rate and high patient satisfaction scores.

Indirect Cost of Traumatic Brachial Plexus Injuries in the United States.

BACKGROUND: Traumatic brachial plexus injuries (BPIs) disproportionately affect young, able-bodied individuals. Beyond direct costs associated with medical treatment, there are far-reaching indirect costs related to disability and lost productivity. Our objective was to estimate per-patient indirect cost associated with BPI. METHODS: We estimated indirect costs as the sum of (1) short-term wage loss, (2) long-term wage loss, and (3) disability payments. Short-term (6-month) wage loss was the product of missed work days and the average earnings per day. The probability of return to work was derived from a systematic review of the literature, and long-term wage loss and disability payments were estimated. Monte Carlo simulation was used to perform a sensitivity analysis of long-term wage loss by varying age, sex, and return to work simultaneously. Disability benefits were estimated from U.S. Social Security Administration data. All cost estimates are in 2018 U.S. dollars. RESULTS: A systematic review of the literature demonstrated that the patients with BPI had a mean age of 26.4 years, 90.5% were male, and manual labor was the most represented occupation. On the basis on these demographics, our base case was a 26-year-old American man working as a manual laborer prior to BPI, with an annual wage of $36,590. Monte Carlo simulation estimated a short-term wage loss of $22,740, a long-term wage loss of $737,551, and disability benefits of $353,671. The mean total indirect cost of traumatic BPI in the Monte Carlo simulations was $1,113,962 per patient over the post-injury lifetime (median: $801,723, interquartile range: $22,740 to $2,350,979). If the probability of the patient returning to work at a different, lower-paying job was doubled, the per-patient total indirect cost was $867,987. CONCLUSIONS: BPI can have a far-reaching economic impact on both individuals and society. If surgical reconstruction enables patients with a BPI to return to work, the indirect cost of this injury decreases. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.