What is the management and prognosis of comminuted impacted subcapital femoral neck fractures, including recovery rate and mortality rate?

From the Guidelines

Comminuted impacted subcapital femoral neck fractures should be managed with arthroplasty in elderly patients, as it is recommended over fixation, with a strong recommendation according to the 2022 AAOS clinical practice guideline summary 1. The management of these complex hip injuries involves surgical intervention, with the specific approach depending on patient age, activity level, and fracture characteristics. For younger patients (<60-65 years), preservation of the native femoral head is preferred through internal fixation using cannulated screws or dynamic hip screws to maintain blood supply and joint function. In elderly patients, arthroplasty is often the treatment of choice, with hemiarthroplasty for less active patients and total hip arthroplasty for more active individuals with good bone quality. Some key points to consider in the management of these fractures include:

• Recovery rates vary significantly, with approximately 70-80% of patients regaining functional mobility, though many do not return to pre-injury levels.
• The one-year mortality rate ranges from 20-30% in elderly patients, primarily due to complications such as deep vein thrombosis, pulmonary embolism, pneumonia, and cardiac events, as reported in the 2019 ACR Appropriateness Criteria for acute hip pain-suspected fracture 1.
• Post-operative care includes early mobilization, weight-bearing as tolerated for arthroplasty patients (restricted weight-bearing for fixation patients), anticoagulation (typically low-molecular-weight heparin like enoxaparin 40mg daily or rivaroxaban 10mg daily for 4-6 weeks), pain management, and rehabilitation focusing on gait training and strengthening exercises.
• Complications include avascular necrosis (particularly in displaced fractures), nonunion, malunion, and hardware failure, which occur more frequently with internal fixation approaches. The 2022 AAOS clinical practice guideline summary also emphasizes the importance of surgical timing, recommending surgery within 24 to 48 hours of hospital admission 1. Additionally, the guideline highlights the need for early mobilization and weight-bearing as tolerated to improve outcomes and reduce the risk of complications. Overall, the management of comminuted impacted subcapital femoral neck fractures requires a comprehensive approach that takes into account the patient's age, activity level, and fracture characteristics, as well as the potential risks and benefits of different treatment options.

From the Research

Management of Comminuted Impacted Subcapital Femoral Neck Fractures

• The management of comminuted impacted subcapital femoral neck fractures involves considering several key factors, including age, timing, comorbidities, bone quality, femoral head vascularization, fracture displacement, intrinsic instability, and comminution, as well as surgeon experience 2.
• In the elderly population, hip replacement is often indicated, while in younger patients, fixation is preferred 2.
• The choice of fixation method depends on the fracture pattern, with sliding hip screws (SHS) being preferable to cannulated screws for displaced or unstable fractures, such as Pauwels II-III or posterior comminution 2.

Prognosis and Recovery Rate

• The prognosis for comminuted impacted subcapital femoral neck fractures is generally poor, with a high risk of complications such as avascular necrosis and non-union 3, 4.
• The recovery rate for these fractures is influenced by factors such as the timing of surgery, fracture displacement, and bone quality 3, 4.
• A study found that cannulated screw fixation resulted in a good outcome in 81.1% of patients, with a poor outcome in 18.9% of patients, primarily due to avascular necrosis or non-union 3.

Mortality Rate

• The mortality rate for comminuted impacted subcapital femoral neck fractures is significant, particularly in the elderly population 5.
• A study found that early surgery and stable fixation can help reduce mortality and improve outcomes in these patients 2.
• However, the exact mortality rate for these fractures is not specified in the available studies, and further research is needed to determine the overall mortality rate and identify factors that influence it.

Fixation Methods

• Different fixation methods have been compared in the management of minimally displaced subcapital neck of femoral fractures, with dynamic hip screw (DHS) being found to be a superior method of fixation 6.
• DHS has high rates of union (99%), low rates of avascular necrosis (<1%), and low rates of fixation failure (<1%) 6.
• However, the choice of fixation method may depend on the specific fracture pattern and patient factors, and further research is needed to determine the best method of fixation for comminuted impacted subcapital femoral neck fractures.