Last Updated on May 19, 2025
Arthrodesis refers to the surgical fusion of a joint, intentionally performed to eliminate movement and stabilize the limb. It differs from ankylosis, which is joint fusion resulting from disease. In essence, arthrodesis is a surgically induced ankylosis.
Syndesis or artificial ankylosis are other names given to arthrodesis.
Arthrodesis aims to block the movement of the joint.
Basis of Arthrodesis
This procedure is typically reserved for painful joints unresponsive to other treatments. It is also considered in flail, unstable, or deformed joints, such as those seen in post-polio sequelae, to improve limb mechanics.
Arthrodesis was commonly performed in the past on major joints such as the shoulder, hip, elbow, and knee. With improvement in orthopedic treatments and the advent of arthroplasty, arthrodesis is rarely performed on large joints now, except in cases where arthroplasty has failed or cannot be done.
In modern times, it is used in hand, ankle, and foot joints. [1] Arthrodesis is a standard part of many stabilization procedures of the spine. [2]
Indications for Arthrodesis
- Painful diseased joints
- Infection
- Osteoarthritis
- Inflammatory arthritis
- Posttraumatic arthritis or instability
- Tumor Surgery including Joint
- Bone excision could be followed by arthrodesis
- Spinal fusion as a part of surgery in spinal fixation
- Failed arthroplasties
Arthrodesis versus Arthroplasty [1]
Before arthroplasty was available, every diseased joint was considered for joint fusion, including the major joints, like the hip or knee joints.
However, the advent of arthroplasty has significantly changed joint management. Joint mobility can be retained by choosing arthroplasty over arthrodesis in most cases of large joints. Thus, indications to fuse large joints like the hip, knee, shoulder, elbow, wrist, and ankle have reduced drastically.
The evolution of custom-made prostheses has led to increased use of prostheses in tumor surgery, too.
However, arthroplasty is avoided in the presence of infection.
Small joints of the foot and, to a lesser extent, hand and wrist can still be well managed by arthrodesis.
The main disadvantage of joint fusion is that it sacrifices the movement of the joint, leading to compromised joint and limb function. For example, in the lower limb, fusion of the hip or knee leads to a drastic increase in energy requirements for ambulation.
Therefore, the fusion is contemplated only in patients in whom the advantages outweigh the disadvantages.
Arthrodesis is also used as the procedure of last resort in some failed arthroplasties.
Types of Arthrodesis
- Intraarticular– The joint surfaces are exposed, and then the procedure is carried out by denuding the joint cartilage and fusing the bone surfaces. This permits greater correction of deformity
- Extraarticular– The joint surfaces are not directly exposed. Instead, fusion is achieved by bridging the joint with bone grafts or blocks. This technique is especially useful in children or in infections like tuberculosis, where joint preservation is important. [3]
- Combined intraarticular and extraarticular.
The Procedure of Arthrodesis
The surgical steps vary depending on the joint. Below is a general outline of the intraarticular arthrodesis technique.
- The involved joint is opened with a suitable approach, and the articular surfaces are exposed.
- The cartilage is removed from the joint surfaces along with any necrotic bone to reveal oozing bone surfaces
- Both ends are shaped for maximum compression at the arthrodesis site.
- The surfaces are apposed together and then fixed with suitable implants.
- Bone grafting is done in most cases to facilitate bone union
- Allograft may be used in large joints, as the quantity of the graft needed is greater
- Different joints are kept in different positions depending on the function of the joint and the energy consumption for the activity.
- Patient demands/profession could be a factor in the position of limbs or digits.
The basic idea is to induce the fusion of the joint in a desirable position and hold the bones in a desirable position till the fusion is strong enough to hold without an internal or external implant.
Complications of Arthrodesis
Joint fusion surgery carries the risk of all complications associated with the surgical procedure. These are
- Infection
- Wound healing issues
- Nonunion of the fused bones
- Awkward gait in the lower limb procedure
- Implant failure
- Stress on adjacent joints
Long-term complications may also include accelerated wear and degeneration in adjacent joints due to altered biomechanics and compensatory stress.
Arthrodesis of Different Joints
Hip Arthrodesis
Fusion of the hip joint is most commonly done in a select group of patients that include failed total hip arthroplasty, young laborers with a unilateral painful hip, etc. As hip arthroplasty advances are made, it is done less and less commonly.
It is not done when bilateral hips are involved, limb length discrepancy is greater than 2.0 cm or there is the presence of degenerative changes in adjacent joints.
The optimum hip fusion position is
- 20-35 degrees of flexion
- 0-5 degrees of adduction
- 5-10 degrees of external rotation
Hip fusion surgery can provide pain relief. Adjacent joint degeneration is a common complication.
Read more details on Hip Arthrodesis.
Knee Arthrodesis
Knee joint fusion surgery is done in cases of failed arthroplasty or complete loss of the extensor mechanism.
Painful ankylosis after infection or trauma, knee joint neuropathic arthropathy, and tumor resection are other indications.
The knee is placed optimal position of the knee during fusion is
- Valgus 5 degrees
- 0-10 degrees of external rotation
- 0-15 degrees of fleion
The procedure is contraindicated in active infection
Absolute contraindications is the presence of active infection.
Knee joint fusion is avoided if the ipsilateral hip or ankle has degenerative changes or bilateral knee fusion is required.
[Know more about knee arthrodesis]
Ankle Arthrodesis
It involves fusion of the tibiotalar joint. It is often done in case of a painful ankle due to infection or trauma, degenerative changes of the ankle causing intractable pain, chronic instability, and avascular necrosis of the talus.
The optimal position for ankle fusion is
- Zero dorsiflexion
- 5-10 degrees of external rotation
- 5 degrees of hindfoot valgus
- 5 mm of posterior translation of the talus
In mild deformities of the ankle, arthroscopic arthrodesis may be done.
[Read more about ankle arthrodesis]
Shoulder Arthrodesis
Shoulder fusion, like hip and knee, is performed less commonly today because arthroplasty has been quite successful in these joints.
The goal of shoulder fusion is to provide a stable base so that hand and elbow functions are optimized.
Shoulder fusion surgery is indicated in paralytic disorders affecting shoulder muscles, tumor removal and reconstruction, and painful shoulder ankylosis following infection.
It is contraindicated in ipsilateral fused elbow and contralateral fused shoulder. It is not done if there is no useful scapulothoracic motion.
The position of the shoulder is optimized so that the person can reach the mouth using the affected limb for feeding purposes.
The position for shoulder fusion is 20-30 degrees of abduction, 20-30 degrees of forward flexion, and 20-30 degrees of internal rotation.
[Read more about shoulder arthrodesis]
Elbow Arthrodesis
It is uncommon and is usually performed as a salvage procedure to provide a stable elbow when arthroplasty has failed. It is also considered in cases of nonunion, segmental bone loss, and severe arthritis.
Optimum position differs for each individual, but as a general guide, 90 degrees of flexion is the most optimum position.
[Read about elbow arthrodesis]
Wrist Arthrodesis
Surgical wrist fusion is a salvage procedure to provide the patient with a pain-free immobile wrist in a maximum functional position. [4]
The procedure is indicated in wrist arthropathy not amenable to conservative treatment.
[Read more about Wrist Arthrodesis]
Arthrodesis of the Foot
Calcaneocuboid, talonavicular, and talocalcaneal joints are mainly fused to correct hindfoot and midfoot issues. [3] Sometimes, all these joints are fused, and the procedure is called triple arthrodesis.
Metatarsophalangeal and phalangeal joints can be fused if the indication arises.
Arthrodesis of Joints of the Hand
The hand is a complex organ, and different joints of the hand are fused in different positions to maximize the functional outcome. The metacarpophalangeal joints and interphalangeal joints are the joints that can be fused. They are discussed in detail in a separate article.
Spine Arthrodesis or Spinal Fusion
In spinal surgery, arthrodesis is commonly referred to as spinal fusion. It is used to stabilize segments of the spine in conditions like degenerative disc disease, deformity (e.g., scoliosis), trauma, infection, and tumor.
Instrumentation (e.g., rods, screws) [2] is used to immobilize the segment while bone grafts promote fusion. In some cases, posterior-only fusion may be used to halt growth on one side of the spine in deformity correction procedures.
It is also done as a standalone procedure to block the growth on one side of the spine [say posterior] to control/contain/ cure deformities using the normal growth potential of the anterior part of the spine, and thus resulting in differential growth of the spine.
In the spine, it is more commonly called spinal fusion.
Prognosis
Arthrodesis means the loss of one joint and thus increasing the energy expenditure of limb function. Apart from that, it also results in the awkwardness of the movement. The patient should be prepared to live with that. Simulation of joint immobilization using a cast or brace prior to surgery can help the patient understand functional limitations and aid in surgical planning.
A well-done fusion results in a pain-free, stable joint at the cost of the motion of joint.
References
- Fischer S, Klug A, Faul P, Hoffmann R, Manegold S, Gramlich Y. Superiority of upper ankle arthrodesis over total ankle replacement in the treatment of end-stage posttraumatic ankle arthrosis. Arch Orthop Trauma Surg. 2022 Mar;142(3):435-442. [PubMed]
- Hanley EN Jr. The indications for lumbar spinal fusion with and without instrumentation. Spine (Phila Pa 1976). 1995 Dec 15;20(24 Suppl):143S-153S. PMID: 8747269.
- Bourelle S, Cottalorda J, Gautheron V, Chavrier Y. Extra-articular subtalar arthrodesis. A long-term follow-up in patients with cerebral palsy. J Bone Joint Surg Br. 2004 Jul;86(5):737-42. [PubMed]
- LoGiudice A, Awan H. Wrist Arthritis and Arthrodesis: Preserving Function, Minimizing Problems. Hand Clin. 2023 Aug;39(3):353-365. [PubMed]
