関: pseudoarthrosis

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/07/22 22:40:21」(JST)

wiki en

Pseudarthrosis (commonly referred to as a nonunion or false joint) is a bone fracture that has no chance of mending without intervention. In pseudarthrosis the body perceives bone fragments as separate bones and does not attempt to unite them. Often this is a the result of inadequate healing after the fracture, though it can also be the result of a developmental failure. In the U.S., FDA guidelines allow a period of 9 months for fracture union, after which intervention is considered to facilitate union.

Etymology

The Greek stem "pseudo-" means false and "arthrosis" means joint. Pseudarthrosis, then, is a false joint. In the case of a "non-union", a fracture that does not heal, this is often evidenced by the obliteration of the medullary cavity of a long bone at the site of the non union. This non union is not a true joint, and has no ligamentous support, but often has motion, and remodels into a rounded end that looks like a true joint.

Causes of Nonunion

Causes related to patient:
1. Age: Common in old age
2. Nutritional status : poor
3. Habits : Nicotine and alcohol consumption
4. Metabolic disturbance : Hyperparathyroidism
Causes related to fracture:
1. Distraction at fracture site
2. Soft tissue interposition
3. Bone loss at the fracture
4. Infection
5. Loss of blood supply
6. Damage of surrounding muscles
Causes related to treatment
1. Inadequate reduction
2. Insufficient immobilization
3. Improperly applied fixation devices.

Types of Nonunion

Judet and Judet, Muller, Weber and Cech, and others classified nonunions into two types according to the viability of the ends of the fragments: Hypervascular nonunions and avascular nonunions.

Hypervascular nonunions are subdivided as:

"Elephant foot" nonunions: These are hypertrophic, rich in callus and are a result of inadequate immobilisation, insecure fixation or premature weight bearing.
"Horse hoof" nonunions: Mildly hypertrophic, poor in callus and is due to unstable fixation.
Oligotrophic nonunions: They are not hypertrophic but vascular, no callus seen and is due to severely displaced fracture or fixation without accurate apposition of fragments.

Avascular nonunions are subdivided as:

Torsion wedge nonunions have an intermediate fragment with decreased or absent blood supply. This fragment has healed to one main fragment but not to the other.
Comminuted nonunions have one or more intermediate fragments that are necrotic.
Defect nonunions has a gap in diaphysis of bone due to a loss of fragment.
Atrophic nonunions usually are the final result when the intermediate fragments are missing and scar tissue that lacks osteogenic potential is left in their place.

Paley classified tibial nonunions based on clinical and roentgenographic characteristics as Type A (Bone loss of less than 1 cm) and Type B (Bone loss of more than 1 cm). Type A is subclassified as Type A:1 Lax type; Lax nonunion have limited mobility and usually some fixed deformity, Type A:2:1 stiff nonunion without deformity and Type A:2:2 stiff nonunion with a deformity. Type B subclassified as Type B:1 bony defect with no shortening, Type B:2 shortening with no gap and Type B:3 there is both gap and shortening.

Treatment

The point of movement can be treated with electrical stimulations that hopefully will trigger the bone cells to form the hydroxyapatite structure that keeps bones from bending too much. More recently, non-unions are treated by bone grafting, internal fixation, and external fixation, including a technique pioneered by Ilizarov, used to compress the bones at the site of the fracture.^[1] Ilizarov originally used bicycle spokes; the modern Taylor Spatial Frame is similar.

Scaphoid pseudarthrosis before and after surgical fixation

Grafting

Donor bone or autologous bone (harvested from the same person undergoing the surgery) is used as a stimulus to bone healing. The presence of the bone is thought to cause stem cells in the circulation and marrow to form cartilage, which then turns to bone, instead of a fibrous scar that forms to heal all other tissues of the body. Bone is the only tissue that can heal without a fibrous scar.

Fixation

Metal plates, pins, screws, and rods, that are screwed or driven into a bone, are used to stabilize the broken bone fragments.

References

^ Niedzielski K, Synder M (2000). "The treatment of pseudarthrosis using the Ilizarov method". Ortop Traumatol Rehabil 2 (3): 46–8. PMID 18034140.

External links

E-radiography
AAOS

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 腰部脊柱管狭窄症：治療および予後 lumbar spinal stenosis treatment and prognosis

English Journal

Immediate fullweightbearing after tarsometatarsal arthrodesis for hallux valgus correction-Does it increase the complication rate?

Gutteck N1, Wohlrab D2, Zeh A2, Radetzki F2, Delank KS2, Lebek S2.
Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons.Foot Ankle Surg.2015 Sep;21(3):198-201. doi: 10.1016/j.fas.2014.11.010. Epub 2014 Dec 29.
BACKGROUND: The arthrodesis of the first tarsometatarsal joint has a high correction potential in the treatment of hallux valgus deformity. Compared to distal correction procedures, a pseudarthrosis rate of 12-20% is quoted, however. In a prospective study the results of two different treatment proc
PMID 26235860

Congenital tibial pseudarthrosis, changes in treatment protocol.

Shabtai L1, Ezra E, Wientroub S, Segev E.
Journal of pediatric orthopedics. Part B.J Pediatr Orthop B.2015 Sep;24(5):444-9. doi: 10.1097/BPB.0000000000000191.
Ten children with congenital pseudarthrosis of the tibia were treated with resection of pathologic bone, bone grafting, intramedullary rodding, compression with circular frame, simultaneous proximal tibia lengthening, and bone morphologic proteins. Thirteen operations were performed to achieve union
PMID 25932825

Complication rates are reduced for revision adult spine deformity surgery among high-volume hospitals and surgeons.

Paul JC1, Lonner BS2, Goz V1, Weinreb J1, Karia R1, Toombs CS1, Errico TJ1.
The spine journal : official journal of the North American Spine Society.Spine J.2015 Sep 1;15(9):1963-72. doi: 10.1016/j.spinee.2015.04.028. Epub 2015 May 1.
BACKGROUND CONTEXT: Revision adult spinal deformity surgery (RASDS) is a particularly high-risk intervention.PURPOSE: The aim was to assess complication rates in RASDS by surgeon and hospital operative volume.STUDY DESIGN/SETTING: This was a retrospective analysis of prospectively collected data.PAT
PMID 25937293