Management of Partial Ankylosis at a Fracture Site
Surgical intervention is strongly recommended for partial ankylosis at fracture sites, as conservative management carries unacceptably high risks of progression to complete ankylosis, functional impairment, and neurological complications.
Clinical Context and Urgency
Partial ankylosis represents an unstable intermediate state that typically progresses without intervention. The specific management approach depends critically on the anatomical location and underlying pathology:
Temporomandibular Joint (TMJ) Ankylosis
Early surgical intervention with interpositional gap arthroplasty using autogenous materials is the treatment of choice for partial TMJ ankylosis. 1, 2
Timing is critical: Type I fibrous ankylosis typically forms 4-5 months post-trauma with mean interincisal opening of 18.3±5.5mm, and progression to Type II bony ankylosis occurs around 1 year post-trauma, causing an additional 5mm reduction in mouth opening 1
Surgical technique: Release arthroplasty with disc repositioning provides stable joint function and mouth opening of 30-45mm in the vast majority of patients 1
Material selection matters: Autogenous interpositional materials demonstrate significantly lower recurrence rates compared to alloplastic materials (p<0.05) 2
Reconstruction options: For more advanced cases, both interpositional gap arthroplasty with autogenous material and reconstruction arthroplasty using either autogenous grafts or total joint replacement show comparable clinical outcomes 2
Recurrence risk: Gap arthroplasty alone shows higher recurrence rates compared to interpositional techniques (p<0.05), with Type IV ankylosis having the highest recurrence rate at 20% 2, 3
Spinal Ankylosis (Ankylosing Spondylitis Context)
For partial ankylosis with segmental instability at spinal fracture sites in ankylosing spondylitis, fusion procedures are strongly recommended. 4
Surgical indications: Fusion should be considered for segmental instability resulting from spinal pseudarthrosis, Andersson lesions, or cases of instability/intractable pain due to spinal fracture 4
Imaging requirements: CT scans are mandatory for all trauma patients with ankylosing spinal disorders, as nondisplaced fractures are easily missed on conventional X-rays; MRI should be added if neurologic involvement is present or suspected 5
Operative urgency: Nonoperative fracture treatment is not recommended given the mechanical instability and inherently high risk of secondary neurologic deterioration; definitive treatment should occur within 24 hours 5
Cervical spine approach: Combined anterior-posterior instrumentation is recommended for cervical spine fractures in patients with ankylosing spondylitis or DISH 5
Thoracolumbar approach: Posterior instrumentation extending 2-3 levels above and below the fracture level is recommended to maintain adequate reduction and stability until fracture healing 5
Technical considerations: Minimally invasive percutaneous pedicle screws with cement augmentation can minimize surgical trauma and strengthen construct stability in patients with diminished bone quality 5
Hip Ankylosis with Fracture
Total hip arthroplasty is strongly recommended for advanced hip arthritis with ankylosis, even in the presence of intertrochanteric fractures. 6
Surgical approach: For intertrochanteric fractures in ankylosed hips, dynamic hip screws with cannulated screws can achieve good union and independent ambulation 7
Prosthesis selection: In younger patients, cementless prostheses are preferred as later revisions are technically easier 4, 8
Timing: Surgery should be performed at hospitals and by orthopedic surgeons highly experienced in joint replacement in patients with ankylosing conditions 6
Critical Pitfalls to Avoid
Never delay imaging: Conventional radiographs are insufficient; CT is mandatory for suspected ankylosis at fracture sites, particularly in ankylosing spinal disorders 5
Avoid conservative management: Observation of partial ankylosis leads to progression, with documented reduction in function and increased surgical complexity 1, 2
Do not use alloplastic interpositional materials: For TMJ ankylosis, autogenous materials show significantly superior outcomes 2
Never perform spinal manipulation: In patients with spinal fusion or advanced spinal osteoporosis, spinal manipulation with high-velocity thrusts is strongly contraindicated due to risk of fractures, spinal cord injury, and paraplegia 6
Maintain spine precautions: For ankylosing spinal disorders with fractures, spine precautions must be maintained at all times until definitive treatment 5