Lumbosacral Plexus

Lumbosacral Plexus

The lumbosacral plexus is easier than the brachial plexus. The sciatic nerve is the key nerve of the lumbosacral plexus. The sciatic nerve has two branches: the common peroneal nerve and the tibial nerve. It arises from the spinal nerves of L4, L5, S1, S2, and S3. The sciatic nerve is the cornerstone of the lumbosacral plexus. Knowledge of the lumbosacral plexus starts with knowledge about the sciatic nerve and its branches because it is the most important nerve. The lumbosacral plexus is predominantly the sciatic nerve, in addition to a small nerve root called S4. The superior gluteal nerve is predominantly L5. The inferior gluteal nerve is predominantly S1. L5 radiculopathy can give you Trendelenburg Gait. The superior gluteal nerve innervates the gluteus medius, gluteus minimus, and the tensor fascia lata muscles. The inferior gluteal nerve innervates the gluteus maximus muscle. When you add S4 to the sciatic nerve, that becomes the lumbosacral plexus (six nerve roots). Each branch will come from three nerve roots, and if you put them in order, the branches from the lumbosacral plexus will have a unique arrangement where the following nerve root will start with the lower numbered nerve root than the previous one.

Pectoralis Major Tear

Pectoralis Major Tear

The pectoralis major insertion is just lateral to the long head of the biceps tendon. The pectoralis major insertion is just lateral to the long head of the biceps tendon. Insertion of the tendons in the proximal part of the humerus: medial to the long head of the biceps is the latissimus dorsi tendon insertion and medial to the latissimus dorsi is the teres major muscle insertion. Pectoralis Major Tear EditedThe subscapularis tendon inserts superiorly on the lesser tuberosity, medial to the biceps tendon. Pectoralis major tear usually occurs in young, male weight lifters during bench pressing from eccentric contraction or lengthening of the muscle. Usually there is pain around the shoulder area, and the patient will feel a “pop” in the shoulder area while performing the bench press. There will be discoloration and burning over the pectoralis into the axilla. There will be swelling, ecchymosis and a palpable defect. The patient will have loss of contour of the axillary fold. MRI will confirm the diagnosis, will localize the site of the tear, and will also differentiate between partial and complete tear. Tendon avulsion is the most common type of injury to the pectoralis major muscle, and the tear is usually a complete tear. Hemorrhage and edema at the level of the proximal humeral shaft indicates a pectoralis major tendon rupture. To treat, reinsert the involved tendon into the humeral shaft, lateral to the biceps tuberosity. Chronic tears will need tendon graft, which is a more complicated surgery. The tendon is usually retracted, and the outcome is not as good as in case of acute repair.

Felon

Felon

A felon is an abscess of the volar bulb of the finger tip that can cause pain and swelling. FelonIt occurs from penetrating trauma such as needles or splinters. The bulb has multiple, small compartments of subcutaneous fat, separated by septi between the dorsal phalanx (bone) and the dermis. The volar distal pulp is septated (multiple septum’s and multiple compartments). When pus occurs, there will be swelling, and the pressure that is built inside of the compartment will lead to multiple, little compartment syndromes. This will lead to vascular compromise and necrosis of the tissue. It also may lead to osteomyelitis of the bone or flexor tenosynovitis. Staphylococcus aureus is the most common organism. It can be treated with incision and drainage. Do not violate the flexor tendon sheath or the DIP joint. Try to break up the septi to decompress the infection. If there is no foreign body in the finger, you will do the midaxial incision or the “J shaped” incision, and you will leave the wound open. If there is a foreign body present, such as a splinter or a thorn, you will do the volar longitudinal incision. Try to avoid doing the “fish mouth” incision, it will lead to unstable finger pulp. Try to avoid doing the double longitudinal incision, it may lead to injury of the neurovascular bundle.

Paronychia

Paronychia

Paronychia can be acute or chronic. It is an infection of the nail fold. It is a common hand infection, usually affecting a single digit. The nail fold will be tender, red, and swollen. ParonychiaIt will sometimes be fluctuant with pus. It can happen from injury or trauma in the paronychia fold, such as a hangnail, nail pitting, manicuring, or due to thumb sucking. Staphylococcus aureus is the most common organism. If the condition occurs early, do warm soaks. You can give the patient antibiotics such as clindamycin or Augmentin. For abscesses, you will do surgery. Do incision and debridement (I&D) with partial or total nail removal, plus antibiotics. Chronic paronychia is different from acute paronychia. It is a fungal infection of the nail fold. Candida albicans is the most common one. Infection occurs more in diabetics. Multiple fingers can be involved. It does not respond to antibiotics. The infection is rare, but can be recurrent. There is no pus. The nail fold is swollen, inflamed, red, tender, and there is no abscess. Chronic paronychia occurs in people who work with a water environment and chemical irritants such as dish washers, bartenders, gardeners, house keepers, or in dealing with laundry. Risk factors include diabetics, patients who take steroids, and patients who take retroviral drugs such as Indinavir, which causes paronychia in HIV positive patients (the condition resolves when they stop taking the medication). To treat chronic paronychia, avoid water, use topical antifungal agents such as miconozole and topical steroids, and surgery at a last resort. Marsupialization is done in severe resistant cases.