Sham surgery (or placebo surgery) is a faked surgical intervention that omits the step thought to be therapeutically necessary.
In clinical trials of surgical interventions, sham surgery is an important scientific control. This is because it isolates the specific effects of the treatment as opposed to the incidental effects caused by anesthesia, the incisional trauma, pre- and postoperative care, and the patient's perception of having had a regular operation. Thus sham surgery serves an analogous purpose to placebo drugs, neutralizing biases such as the placebo effect.
A number of studies done under Institutional Review Board-approved settings have delivered important and surprising results. With the progress in minimally invasive surgery, sham procedures can be more easily performed as the sham incision can be kept small similarly to the incision in the studied procedure.
A review of studies with sham surgery found 53 such studies: in 39 there was improvement with the sham operation and in 27 the sham procedure was as good as the real operation. [1] Sham-controlled interventions have therefore identified interventions that are useless but had been believed by the medical community to be helpful based on studies without the use of sham surgery. [2] [3] [4] [5] [6]
In 1939 Fieschi introduced internal mammary ligation as a procedure to improve blood flow to the heart. Not until a controlled study was done two decades later could it be demonstrated that the procedure was only as effective as the sham surgery. [2] [3]
In neurosurgery, cell-transplant surgical interventions were offered in many centers in the world for patients with Parkinson disease until sham-controlled experiments involving the drilling of burr holes into the skull demonstrated such interventions to be ineffective and possibly harmful. [4] Subsequently, over 90% of surveyed investigators believed that future neurosurgical interventions (e.g. gene transfer therapies) should be evaluated by sham-controlled studies as these are superior to open-control designs, and have found it unethical to conduct an open-control study because the design is not strong enough to protect against the placebo effect and bias. [4] Kim et al. point out that sham procedures can differ significantly in invasiveness, for instance in neurosurgical experiments the investigator may drill a burr hole to the dura mater only or enter the brain. [4] In March 2013 a sham surgical study of a popular but biologically inexplicable venous balloon angioplasty procedure for multiple sclerosis showed the surgery was no better than placebo.
Moseley and coworkers studied the effect of arthroscopic surgery for osteoarthritis of the knee establishing two treatment groups and a sham-operated control group. [5] They found that patients in the treatment group did no better than those in the control group. The fact that all three groups improved equally points to the placebo effect in surgical interventions.
In a 2016 study it was found that arthroscopic partial meniscectomy does not offer any benefit over sham surgery in relieving symptoms of knee locking or catching in patients with degenerative meniscal tears. [6]
A randomised controlled trial was carried out to investigate the effectiveness of shoulder surgery to remove an acromial spur (bony protuberance on x-ray) in patients with shoulder pain. This found that improvement after sham surgery was as great as with real surgery. [7]
A systematic review has identified a number of studies comparing orthopedic surgery to sham surgery. This demonstrates that it is possible to undertake such studies and that the findings are important. [8]
Sham surgery has been widely used in surgical animal models. Historically, studies in animals also allowed the removal or alteration of an organ; using sham-operated animals as control, deductions could be made about the function of the organ. Sham interventions can also be performed as controls when new surgical procedures are developed.[ citation needed ]
For instance, a study documenting the effect of ONS (Optical Nerve Section) on Guinea pigs detailed its sham surgery as: [9] "In the case of optic nerve section, a small incision was then made in the dural sheath of the optic nerve to access the nerve fibers, which were teased free and cut. The same procedure was followed for animals undergoing sham surgery, except that the optic nerve was left intact after visualization."[ citation needed ]
Idiopathic intracranial hypertension (IIH), previously known as pseudotumor cerebri and benign intracranial hypertension, is a condition characterized by increased intracranial pressure without a detectable cause. The main symptoms are headache, vision problems, ringing in the ears, and shoulder pain. Complications may include vision loss.
Laparoscopy is an operation performed in the abdomen or pelvis using small incisions with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.
Arthroscopy is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the joint through a small incision. Arthroscopic procedures can be performed during ACL reconstruction.
The rotator cuff is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are:
In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expectations, observer's effect on the participants, observer bias, confirmation bias, and other sources. A blind can be imposed on any participant of an experiment, including subjects, researchers, technicians, data analysts, and evaluators. In some cases, while blinding would be useful, it is impossible or unethical. For example, it is not possible to blind a patient to their treatment in a physical therapy intervention. A good clinical protocol ensures that blinding is as effective as possible within ethical and practical constraints.
Minimally invasive procedures encompass surgical techniques that limit the size of incisions needed, thereby reducing wound healing time, associated pain, and risk of infection. Surgery by definition is invasive and many operations requiring incisions of some size are referred to as open surgery. Incisions made during open surgery can sometimes leave large wounds that may be painful and take a long time to heal. Advancements in medical technologies have enabled the development and regular use of minimally invasive procedures. For example, endovascular aneurysm repair, a minimally invasive surgery, has become the most common method of repairing abdominal aortic aneurysms in the US as of 2003. The procedure involves much smaller incisions than the corresponding open surgery procedure of open aortic surgery.
Anterior ischemic optic neuropathy (AION) is a medical condition involving loss of vision caused by damage to the optic nerve as a result of insufficient blood supply (ischemia). This form of ischemic optic neuropathy is generally categorized as two types: arteritic AION, in which the loss of vision is the result of an inflammatory disease of arteries in the head called temporal arteritis, and non-arteritic AION, which is due to non-inflammatory disease of small blood vessels.
Morton's neuroma is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces, which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by ceasing to wear footwear with tight toe boxes and high heels. The condition is named after Thomas George Morton, though it was first correctly described by a chiropodist named Durlacher.
A neurectomy, or nerve resection is a neurosurgical procedure in which a peripheral nerve is cut or removed to alleviate neuropathic pain or permanently disable some function of a nerve. The nerve is not intended to grow back. For chronic pain it may be an alternative to a failed nerve decompression when the target nerve has no motor function and numbness is acceptable. Neurectomies have also been used to permanently block autonomic function, and special sensory function not related to pain.
Subacromial bursitis is a condition caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon from the overlying coraco-acromial ligament, acromion, and coracoid and from the deep surface of the deltoid muscle. The subacromial bursa helps the motion of the supraspinatus tendon of the rotator cuff in activities such as overhead work.
Shoulder replacement is a surgical procedure in which all or part of the glenohumeral joint is replaced by a prosthetic implant. Such joint replacement surgery generally is conducted to relieve arthritis pain or fix severe physical joint damage.
Acromioplasty is an arthroscopic surgical procedure of the acromion.
A tear of a meniscus is a rupturing of one or more of the fibrocartilage strips in the knee called menisci. When doctors and patients refer to "torn cartilage" in the knee, they actually may be referring to an injury to a meniscus at the top of one of the tibiae. Menisci can be torn during innocuous activities such as walking or squatting. They can also be torn by traumatic force encountered in sports or other forms of physical exertion. The traumatic action is most often a twisting movement at the knee while the leg is bent. In older adults, the meniscus can be damaged following prolonged 'wear and tear'. Especially acute injuries can lead to displaced tears which can cause mechanical symptoms such as clicking, catching, or locking during motion of the joint. The joint will be in pain when in use, but when there is no load, the pain goes away.
Articular cartilage repair treatment involves the repair of the surface of the articular joint's hyaline cartilage. Over the last few decades, surgeons and researchers have made progress in elaborating surgical cartilage repair interventions. Though these solutions do not perfectly restore the articular cartilage, some of the latest technologies have started to bring very promising results in repairing cartilages from traumatic injuries or chondropathies. These treatments have been shown to be especially beneficial for patients who have articular cartilage damage. They can provide some measure of pain relief, while at the same time slowing down the accumulation of damage, or considerably delaying the need for joint replacement surgery.
Shoulder impingement syndrome is a syndrome involving tendonitis of the rotator cuff muscles as they pass through the subacromial space, the passage beneath the acromion. It is particularly associated with tendonitis of the supraspinatus muscle. This can result in pain, weakness, and loss of movement at the shoulder.
Endoscopic carpal tunnel release (ECTR) refers to a method of performing carpal tunnel surgery using an endoscope or an arthroscopic device to provide visualization of the anatomic structures.
Hip arthroscopy refers to the viewing of the interior of the acetabulofemoral (hip) joint through an arthroscope and the treatment of hip pathology through a minimally invasive approach. This technique is sometimes used to help in the treatment of various joint disorders and has gained popularity because of the small incisions used and shorter recovery times when compared with conventional surgical techniques. Hip arthroscopy was not feasible until recently, new technology in both the tools used and the ability to distract the hip joint has led to a recent surge in the ability to do hip arthroscopy and the popularity of it.
Occipital nerve stimulation (ONS), also called peripheral nerve stimulation (PNS) of the occipital nerves, is used to treat chronic migraine patients who have failed to respond to pharmaceutical treatments.
Carpal tunnel surgery, also called carpal tunnel release (CTR) and carpal tunnel decompression surgery, is a nerve decompression in which the transverse carpal ligament is divided. It is a surgical treatment for carpal tunnel syndrome (CTS) and recommended when there is constant (not just intermittent) numbness, muscle weakness, or atrophy, and when night-splinting no longer controls intermittent symptoms of pain in the carpal tunnel. In general, milder cases can be controlled for months to years, but severe cases are unrelenting symptomatically and are likely to result in surgical treatment. Approximately 500,000 surgical procedures are performed each year, and the economic impact of this condition is estimated to exceed $2 billion annually.
A nerve decompression is a neurosurgical procedure to relieve chronic, direct pressure on a nerve to treat nerve entrapment, a pain syndrome characterized by severe chronic pain and muscle weakness. In this way a nerve decompression targets the underlying pathophysiology of the syndrome and is considered a first-line surgical treatment option for peripheral nerve pain. Despite treating the underlying cause of the disease, the symptoms may not be fully reversible as delays in diagnosis can allow permanent damage to occur to the nerve and surrounding microvasculature. Traditionally only nerves accessible with open surgery have been good candidates, however innovations in laparoscopy and nerve-sparing techniques made nearly all nerves in the body good candidates, as surgical access is no longer a barrier.