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Neuritis of the anterior interosseous nerve (AIN) exists, but entrapment of this nerve does not.
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When a nerve is entrapped proximally, its distal part becomes swollen and often compressed by normal structures. The “double crush” by entrapment at two levels is less common.
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Starting motion therapy of the hand within a week after surgery can be replaced with starting motion therapy at 2 or 3 weeks in most patients.
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Short splints will be used more frequently in the future.
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Proximal pole fractures of
10 Hypotheses in Hand Surgery
Section snippets
Key points
Neuritis of the Anterior Interosseous Nerve Exists, but Entrapment Does Not
I put this as the first hypothesis because this topic was recently discussed among several senior surgeons,1, 2, 3, 4 and the consensus was that anterior interosseous nerve (AIN) entrapment may not exist. It is possible that the swollen AIN after neuritis initiates compression by the normal structures that surround it (Fig. 1). Immediate decompression of the AIN may eliminate such compression, and symptoms can disappear immediately; but without surgical decompression, the symptoms may
When a Nerve Is Entrapped Proximally, Distally It Becomes Swollen and Often Compressed by Normal Structures. Mechanical Entrapment at Two Levels Is less Common
There are a lot of uncertainties and disagreements regarding double crush syndrome. This term was first used in 1973, after Upton and McComas5 had assessed a large group of patients with cervical root lesions and upper extremity peripheral entrapment neuropathies—either carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow, or both. They proposed that focal compression often occurs at more than one level along the course of a single nerve fiber.
Upton and McComas5 proposed that under these
Early Surgical Decompression to Forearm Entrapment Neuropathy Is Beneficial to Help Speedy Recovery and Avoid Symptoms and Dysfunction Associated with Lengthy Conservative Treatment
Continuing with the discussion in hypothesis 2, this hypothesis is not about long-term outcome but rather the possible merits of immediate relief of symptoms with surgical intervention.
I have discussed this with a surgeon who operated a lot of patients with median and radial nerve compressions in the proximal forearm. I agree that early surgical release without commonly suggested lengthy conservative treatment (6 months) may have merits. The immediate return of the muscle powers of the fingers
Ruptured Digital Flexor Tendons Can Be Repaired Directly After a Quite Lengthy Delay, and Muscle Elasticity Can Be Restored
Several surgeons have already voice this possibility, but clinical data are insufficient to define exact length of delay and in what circumstances this delayed primary repair is possible and should be attempted. I do not have a large number of the patients who came to me a month after trauma. I found in several of them, however, that I could do primary repairs, even after 3 or 6 months, and they finally recovered digital function without additional surgery. Questions remain regarding how long
Starting Motion Therapy Within a Week after Surgery Can Be Delayed to Week 2 or 3 in Most Patients
In my practice, except for primary flexor tendon repair, I do not start “immediate” early active motion, and this practice has served me well.19 I usually start motion therapy at week 2 to 3 depending on structures repaired or surgeries done (Fig. 3). I have not found any major problems with delaying the initiation of motion therapy. I learnt other surgeons to start early active motion from very first week after surgery and have doubted whether this is necessary or makes much difference from
Short Splints Will Be Used in Many More Patients in the Years to Come
I see the use of a short splint a future trend as we understand more and more about tissue healing and we improve the mechanical strength of surgical repairs. After flexor tendon repair, a short splint (from wrist to fingertip or from forearm to fingertip) is already popular.20, 21, 22 After extensor tendon repair in the fingers or thumb, a shorter splint from distal forearm to the digital tip is fine, because the currently used surgical repair methods are strong, which can tolerate a lot of
Fractures of the Scaphoid Proximal Pole Are Treated Conservatively by Many Surgeons
The proximal pole fracture involves the proximal 20% of the scaphoid and is uncommon (<5% of all scaphoid fractures). Published data on union incidence can lead to different treatment recommendations. The suggestion of using surgical treatment for this fracture is based on reported 20% to 50% (on average 1/3) incidences of nonunion after casting.24,25 This same healing incidence can also be interpreted as two-third of the cases do not need surgery. A more recent study showed that 90% of 52
Compartment Syndrome in the Forearm Is Treated with Multiple Shorter Incisions Without Skin Graft in Most Patients
In decompression of the forearm compartments, classical teaching is a long S-shaped incision, often followed later by a skin graft. This is proper in a severe case of forearm compartment syndrome, which needs extensive debridement of nonviable tissues and thorough decompression of the nerves and vessels. In modern times, such severe involvement is seldom seen, because the patient is diagnosed and treated before tissues necrosis. I hypothesize in the future that multiple shorter incision in the
Small Free or Pedicled Flap Transfers to Fingers Will No Longer Be Used as Artificial Skin Substitutes Become Popular
Many of my colleagues find that they use smaller flaps in the hand less frequently in recent years. Even large free flap transfers are less often necessary because of the use of artificial dermal templates for small defects and vacuum-assisted closure of a large defect, which stimulates formation of granulation tissue and allows epithelialization over the granulation tissue. I use Integra (Integra LifeSciences, Plainsboro, NJ) in patients with defects in dorsal aspect of the finger (including
Elevation of the Operated Hand after Surgery IS UNNECESSARY Unless the Trauma or Surgery Is Extensive or Severe Hand Edema Is Expected
I was brought up in my training and practice to instruct patients to elevate their hands to after major surgery that might cause marked edema of the hand or upper extremity. I encountered colleagues who give postoperative orders to almost all patients to elevate their operated hands, sometimes to the level of the head. I do not see reports that such elevation improves outcomes. It is possible that elevation decreases pain, and indeed sometimes the patient feels more comfortable to elevate the
Summary
I have put together the several topics and labeled them as hypotheses. My preferred approaches and practices are outlined and the rationales or considerations are given. Some are different from those used by others, but I have found no proof whether my methods are better or worse than those used by others. These hypotheses are to stimulate thinking, clinical observation and investigations, and highlight several areas of future research. I hope clarification will improve our understanding of
Clinics care points
Neuritis of the anterior interosseous nerve (AIN) exists, but entrapment of this nerve does not. When a nerve is entrapped proximally, its distal part becomes swollen and often compressed by normal structures. The “double crush” by entrapment at two levels is less common. Starting motion therapy within a week after surgery can be replaced with starting motion therapy at 2 or 3 weeks in most patients. Only the patient with primary flexor tendon repair need initiation of active flexion motion
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proximal pole scaphoid fractures: a computed tomographic assessment of outcomes
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(2016) Proximal median nerve compressions: anterior interosseous nerve compression - a myth
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(2022)Compression to the anterior interosseous nerve is very rare: compression by the normal tissues surrounding it may not exist
J Hand Surg Eur
(2022)My current views on the anterior interosseous nerve syndrome
J Hand Surg Eur
(2022)Two clinical observations: pronator syndrome in violinists and anterior interosseous nerve syndrome with pure motor loss
J Hand Surg Eur
(2022)
Chronic nerve compression model for the double crush hypothesis
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Double crush syndrome
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Double-crush syndrome: a critical analysis
Neurology
Median nerve mononeuropathy in spondylotic cervical myelopathy: Double crush syndrome?
J Neurol
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