Complications of various surgical treatments
Surgical management may involve either preserving the native joint or replacing it. Each approach has characteristic late complications.
With osteosynthesis (internal fixation with metal implants), physicians most commonly encounter the following problems:
- Failure of bone fragments to unite (non-union).
- Development of a deep infection in the surgical site.
- Mechanical failure of the implanted device.
- Avascular necrosis of the femoral head, which manifests between two and four years after surgery.
In cases of arthroplasty (joint replacement), the complication profile changes:
- Dislocation of artificial joint components.
- Aseptic or septic loosening of the endoprosthesis due to normal wear and tear.
- Bone fractures around the implanted prosthesis (periprosthetic fractures).
When late complications of arthroplasty occur, patients generally require complex revision arthroplasty, the decision for which is made taking into account the patient's somatic condition.
Impact of muscle pull on post-injury deformity
The femur is surrounded by a powerful muscle mass. When bone integrity is compromised, muscles continue to contract, causing typical fragment displacement patterns:
- Anterior fascial compartment: the quadriceps femoris muscle (m. quadriceps femoris) pulls fragments axially, leading to marked limb shortening.
- Posterior fascial compartment (hamstrings): the biceps femoris, semimembranosus, and semitendinosus muscles also promote longitudinal femoral shortening.
- Medial fascial compartment: adductor muscles not only shorten the leg but also cause varus deformity (bowing).
- Hip joint muscles: act on the proximal fragment. Abductors pull it outward via the greater trochanter, flexors pull it forward via the lesser trochanter, and external rotators rotate the fragment outward.
- Gastrocnemius muscle (m. gastrocnemius): in diaphyseal fractures, it causes hyperextension of the distal fragment, forming an angular deformity with an anterior apex.
Prevention and features of geriatric trauma
In elderly patients, fractures occur against the background of frailty (frailty), sarcopenia, and osteoporosis with minimal trauma, such as a fall from standing height. The most formidable prognostic factor is a prior history of a low-energy fracture (e.g., of the radius or spine).
The FRAX calculator is used to assess risks. Pharmacological prevention with bisphosphonates is effective only with decreased bone mineral density. In individuals with normal bone density, these drugs do not work, and their prolonged use in osteoporosis can cause an atypical fracture in the subtrochanteric region.
In addition to bone pathology, home environment modification is of critical importance: eliminating slippery floors, poor lighting, and old rugs. The risk of falls increases significantly in patients with neurological deficits, visual impairments (the presence of cataracts triples the risk of fracture), and those taking sedative medications (polypharmacy).
Specific fractures and diagnostic challenges
Certain femoral injuries are difficult to diagnose using standard methods.
- Ipsilateral femoral neck fracture: accompanies one in ten diaphyseal fractures. Due to attention being diverted to the primary injury, it is missed in 20–50% of cases. Delayed diagnosis leads to displacement and a high risk of necrosis. CT or radiography with internal rotation is required.
- Hoffa fracture: injury to the posterior part of the femoral condyle. The fracture line runs in the coronal plane, so the injury is not visible on standard anteroposterior radiographs—performing a CT scan is mandatory for diagnosis.
- Avulsion fractures of the trochanters: isolated injuries of the greater or lesser trochanter occur due to sudden muscle contraction. They are treated predominantly conservatively.
Briefly: answers to topical questions
What types of metal implants are used for the osteosynthesis of femoral neck fractures?
Specialized fixators are used for the osteosynthesis of nondisplaced or minimally stable displaced femoral neck fractures.
- Parallel screws or pins (parallel screws or pins) are rigidly fixed in the femoral head, but have the ability to slide, providing compression of bone fragments under axial load.
What classifications are used to evaluate femoral neck fractures in traumatology?
The following classifications are used in traumatology to evaluate femoral neck fractures:
- Pauwels classification (Pauwels) assesses the direction of the fracture line relative to the horizontal plane.
- Garden classification (Garden) assesses the degree and pattern of displacement of bone fragments.
- AO/OTA classification (AO/OTA) — intracapsular femoral neck fractures are coded 31B and are subdivided into subcapital, transcervical, and basicervical fractures.
What is the pathogenesis of fat embolism syndrome in long bone fractures?
The pathogenesis of fat embolism syndrome in long bone fractures includes mechanical and biochemical factors.
- Mechanical factor — fat from the medullary cavity exposed during the fracture enters the bloodstream and migrates to the lungs.
- Biochemical factor — post-traumatic elevation of blood lipase levels contributes to the development of alveolar-interstitial edema.
- Cerebral form of fat embolism — lung tissue ischemia leads to the opening of veno-arterial shunts, through which emboli penetrate the brain.
For the comprehensive management of elderly patients with hip fractures, the APGAR SCORE checklist is used: A — Alimentation (nutrition, albumin and vitamin D monitoring); P — Polypharmacy (combating polypharmacy); G — Gait (gait assessment and physical therapy); A — Advance Care Planning (care planning); R — Reversible Cognitive Impairment (delirium prevention); S — Social Support (social support); C — Cataracts (vision screening); O — Osteoporosis (densitometry and therapy); R — Referrals (continuity of care); E — Environmental Safety (home safety).
Class and exam questions
Are bisphosphonates effective for fracture prevention in all elderly people?
No, the drugs reduce the risk of hip fractures only in individuals with confirmed osteoporosis. With normal bone mineral density, they do not prevent injuries.
What are the risks of high-energy femoral shaft fractures?
In addition to massive blood loss and the risk of multi-organ failure, the exposed medullary cavity can become a source of fat embolism, causing pulmonary dysfunction and hypoxia.
Why is a thorough examination of the hip joint necessary in diaphyseal fractures?
In 10% of cases, diaphyseal trauma is accompanied by a femoral neck fracture on the same side. If missed, fragment displacement will occur, sharply increasing the risk of avascular necrosis of the head.
What else to study on this topic
- Fat embolism syndrome: pathogenesis and clinical features
- Principles of intramedullary and plate osteosynthesis
- Radiological diagnosis of intra-articular fractures
- Atypical femoral fractures: mechanism of development
- Dual-energy X-ray absorptiometry (DEXA)
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