Could Human Amniotic Membrane Have An Impact In Hallux Limitus Procedures?
- Volume 25 - Issue 7 - July 2012
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Hallux limitus is a decrease in sagittal plane dorsiflexion of the hallux at the first metatarsophalangeal joint (MPJ). Hallux rigidus is a term that clinicians often use interchangeably with hallux limitus but hallux rigidus describes the absence of motion or severely restricted motion of the first MPJ. The normal range of dorsiflexion of the first MPJ should be 65 to 75 degrees to allow for normal propulsion during gait. A limitation of motion at the first MPJ has a variety of potential causes including an elevated first metatarsal, a hypermobile first ray, a long first metatarsal, a square first metatarsal head or trauma.
Regnauld and Drago classified hallux limitus into four stages.1,2 Stage 1 is a functional limitation of motion at the first MPJ when the foot is in a weightbearing or loaded position. There is mild pain but no degenerative joint changes on X-ray. Stage 2 is a mild limitation of motion at the first MPJ with radiographic changes. There is a mild flattening of the metatarsal head and small dorsal exostosis visible on X-ray. In stage 3, patients have a moderate limitation of motion with non-uniform joint space narrowing, dorsal osteophytes, subchondral cysts and sclerosis of the joint on radiographs. In stage 4, patients have an absence of motion to minimal motion at the first MPJ with obliteration of the joint space on X-ray.
Conservative treatment of hallux limitus involves oral anti-inflammatories, physical therapy or steroid injections. An orthotic may be beneficial in plantarflexing the first metatarsal to increase range of motion or restricting the motion in the first MPJ with a Morton’s extension to reduce pain. Stiff soled shoes or rocker bottom shoes will often be beneficial in patients with hallux limitus to assist with propulsion.
For severe arthritis or late-stage hallux limitus, we recommend a joint destructive procedure such as an implant or arthrodesis. For mild cases of hallux limitus, a cheilectomy and/or joint decompression is often indicated. A common complication or development after a joint decompression or cheilectomy is stiffness or adhesions to the first MPJ. Often, patients will need physical therapy to reduce scar tissue and adhesions in the joint. Occasionally, patients may need to return to the operating room for manipulation of the first MPJ under anesthesia to get increased motion in the joint.
Investigating The Potential Of Human Amniotic Membrane
Human amniotic membrane is a new material that can reduce adhesions and scarring in the joint, allowing patients to have better range of motion in the joint sooner. Human amniotic membrane is the innermost lining of the placenta and consists of three layers: a single layer of epithelial cells, a thick basement membrane and an avascular stroma.
Human amniotic membrane has low immunogenicity and research has demonstrated that it has anti-adhesive, anti-inflammatory and antimicrobial properties.3 Amniotic membrane has been in use in wound healing, the management of burns and prevention of adhesions. Physicians have used the membrane often in ocular repair to reduce the scarring and inflammation associated with eye procedures. In foot surgery, adhesions are a common complication of many procedures. They may prevent full recovery and can cause residual pain in some patients. Many studies have evaluated the use of human amniotic membrane on various structures and most have shown the reduction of adhesions in various animal models.3-8