Nonunion after fracture of the hip and pelvis

Anatomy and healing biology of the hip and pelvis

The hip includes the hip socket (acetabulum) and thigh bone (femur) with the femoral neck, head, trochanter region and shaft. The pelvis consists of the ilium, ischium, pubic bone and the pelvic ring with the sacroiliac joint (SIJ) and symphysis. These areas are exposed to high levels of stress; Their blood supply and mechanical stability largely determine bone healing.

• Healing phases: Inflammation (days) – repair/callus formation (weeks) – remodeling (months).
• Essential factors: stable fracture fixation, adequate blood flow, healthy soft tissues, correct axis/rotation.
• Risk zones: femoral neck (endarterial supply, risk of femoral head necrosis), subtrochanteric (strong bending forces), pelvic ring (complex stress).

What is a nonunion?

A pseudoarthrosis (nonunion) occurs when a bone fracture does not heal despite sufficient time. Clinically there is persistent pain and/or instability, radiologically there is no bony structure. The diagnosis is often made after 6-9 months without any signs of healing; the timing depends on the location and course.

• Delayed Union: slow but noticeably progressive consolidation.
• Pseudarthrosis (nonunion): no healing progress; A “false joint formation” may occur with movement in the fracture gap.
• Meaning: Pain, reduced resilience, misalignments, loss of function and increased risk of further complications.

Causes and risk factors

Nonunions occur due to an imbalance between biological regeneration and mechanical stability. Often several factors work together.

• Local: insufficient stability of the osteosynthesis, misalignment (axis/rotation), fracture gap, soft tissue damage, circulatory disorder (e.g. femoral neck), infection.
• Systemic: smoking/nicotine, diabetes mellitus, malnutrition (especially protein), vitamin D deficiency, osteoporosis, thyroid/hormone disorders, anemia.
• Medications/Influences: Corticosteroids, immunosuppressive therapies; The influence of NSAIDs on bone healing is controversial and should be considered individually.
• Fracture-specific: high-energy or multi-fragmentary fractures, open fractures, intertrochanteric/subtrochanteric fractures, pelvic ring injuries.
• Therapy-related: too early full weight bearing, infection after osteosynthesis, inappropriate choice of implant.

Symptoms: How to recognize a nonunion

• Persistent pain related to stress or movement months after the fracture/surgery.
• Sensation of instability, “cracking” or movement in the fracture area.
• Limited leg strength, limping gait.
• Difference in leg length (especially in the femoral neck region).
• Swelling, warm or red skin, impaired wound healing - can indicate an infection.

Diagnostics in practice

We combine history, clinical examination and staged imaging. The aim is to clarify the cause (biomechanics vs. biology vs. infection) in order to plan therapy specifically.

• Medical history: mechanism of the accident, previous operations, stress, pain, previous illnesses (e.g. diabetes), nicotine.
• Clinic: Axis/rotation test, leg length, soft tissues, scar condition, pain location.
• X-ray in two planes; Whole leg or pelvic overview for axis and joint assessment.
• CT for detailed callus and cleft assessment (especially subtrochanteric/acetabulum).
• MRI or special sequences if avascular necrosis of the femoral head is suspected.
• Laboratory: inflammatory parameters (CRP, ESR, blood count). If infection is suspected, puncture/swabbing in the operating room with microbiological diagnostics may be necessary.
• Bone density (DXA) if osteoporosis is suspected.
• Differential diagnoses: necrosis of the femoral head, stress fractures, pelvic instability, osteitis pubis.

Classification and significance for therapy

The classification helps to derive the optimal treatment strategy.

• Vital/hypertrophic: strong but not bridging callus formation – usually stability problem; Therapy: Fixation optimization.
• Oligotrophic: little callus – combines biological and mechanical problem.
• Avital/atrophic: hardly any callus, sclerosed fracture ends – biological deficit; Therapy: Debridement, bone graft plus stable osteosynthesis.
• Infected nonunion: bacterial colonization – requires infection cleansing with debridement and coordinated antibiosis, often in two stages.

Conservative treatment – ​​when does it make sense?

Conservative measures can improve healing conditions, but do not replace necessary surgical correction. They are suitable for delayed healing or selected stable nonunions without misalignment/infection.

• Optimization of risk factors: nicotine avoidance, blood sugar control, protein intake, vitamin D/calcium, treatment of osteoporosis.
• Load control: temporary partial relief with crutches, adapted physiotherapy to stabilize muscles.
• Bone stimulation: low-intensity ultrasound (LIPUS) or pulsed electromagnetic fields (PEMF) – evidence heterogeneous; Use individually.
• pain therapy as needed; NSAIDs and their influence on healing are considered individually.
• Infection control: If there is evidence of infection, conservative therapy alone is usually not sufficient.

Operational options – principles and procedures

If stability or biology are inadequate, surgery is often the best option. Goal: (1) eliminate cause, (2) restore axis/rotation, (3) stable fixation, (4) biological support. We will provide you with comprehensive advice and, if necessary, coordinate the operation in a specialized center.

• Debridement: Removal of scar tissue, fibrous fracture ends and non-vital bone until vital bleeding occurs (“Paprika sign”).
• Stable osteosynthesis: angle-stable plates, locking nails, interchangeable nailing or plate-nail combination; dynamic locking to promote callus.
• Bone grafting: autologous cancellous bone (usually iliac crest), if necessary structural bone chips; If necessary, combination with bone replacement materials.
• Induced membrane (Masquelet technique) for larger defects: two-stage procedure with spacers and later cancellous plastic.
• Callus distraction/segment transport (Ilizarov/Hexapod) for complex defects or misalignments.
• Biological augmentation: Bone marrow concentrates (BMAC) or growth factors are used in individual cases; Benefit depends on indication and evidence.
• Infected nonunion: radical infection cleansing, targeted antibiotics, temporary stabilization; definitive reconstruction after germ control.
• Specifically femoral neck: reconstruction/conversion osteotomy possible in younger people; In the case of advanced osteoarthritis or necrosis, an endoprosthesis may be necessary (indication in the center).

Special locations on the hip and pelvis

• Femoral neck: risk of femoral head necrosis; Therapy depends on blood circulation, age and joint status.
• Inter-/subtrochanteric: strong bending and torsional forces; Frequently changing to a stable angle plate or locking nail with cancellous bone.
• Femoral shaft near hip: biomechanically demanding, if necessary dynamic locking/replacement nail with transplant.
• Acetabulum: Proximity to the joint requires precise reduction; CT planning essential.
• Pelvic ring/symphysis: Pseudarthrosis can cause pain and pelvic instability; Stabilization and, if necessary, bone transplantation.

Aftercare, rehabilitation and everyday life

Structured follow-up treatment is crucial for success – regardless of whether the treatment is conservative or surgical.

• Load build-up according to plan: clear guidelines for partial load, gradual increase based on clinic and X-ray checks.
• Physiotherapy: gait training, muscle building (gluteal muscles, core), mobility, proprioception.
• Thrombosis and pain prophylaxis in coordination with your family doctor/surgeon.
• Regular image checks (X-ray/CT as required).
• Bone health: vitamin D, calcium, adequate protein intake; Osteoporosis diagnosis and therapy.
• Return to work and sport: individually dependent on healing and activity; Obtain approval before full load.

Prevention: What you can do yourself

• Quitting smoking – one of the most important factors that can be influenced.
• Balanced diet with sufficient protein, vitamin D and calcium.
• Consistent treatment of underlying diseases (e.g. diabetes).
• Adherence to therapy: Adhere to protective loads and follow-up care, use physiotherapy.
• Fall prevention: strength and balance training, aids if necessary.
• Early medical check-up if pain persists after fracture/surgery.

When should you urgently see a doctor?

• Increasing pain, new instability or sudden misalignment.
• Redness, overheating, fever, secretion from the scar - suspected infection.
• Numbness, severe swelling, calf pain or shortness of breath - suspected thrombosis/embolism.
• Fall event with subsequent deterioration in resilience.

What we do for you in Hamburg

As an orthopedic specialist practice, we focus on careful diagnostics, conservative therapy optimization and an independent, evidence-based second opinion on the indication for surgery. If necessary, we will promptly coordinate treatment in specialized surgical centers and provide follow-up care close to home.

• Individual treatment planning with realistic goals – no promises of cure.
• Optimization of risk factors (bone health, metabolism, nicotine) and load control.
• Organization of further imaging (CT/MRI) and infectious diagnostics.
• Rehabilitation and follow-up checks in our practice, Dorotheenstraße 48, 22301 Hamburg.