Magnetic resonance imaging (MRI) and ultrasound are comparable in efficacy and helpful in diagnosis although both have a false positive rate of 15 - 20%. MRI can reliably detect most full-thickness tears although very small pinpoint tears may be missed. In such situations, an MRI combined with an injection of contrast material, an MR-arthrogram, may help to confirm the diagnosis. It should be realized that a normal MRI cannot fully rule out a small tear (a false negative) while partial-thickness tears are not as reliably detected. While MRI is sensitive in identifying tendon degeneration (tendinopathy), it may not reliably distinguish between a degenerative tendon and a partially torn tendon. Again, magnetic resonance arthrography can improve the differentiation. An overall sensitivity of 91% (9% false negative rate) has been reported indicating that magnetic resonance arthrography is reliable in the detection of partial-thickness rotator cuff tears. However, its routine use is not advised, since it involves entering the joint with a needle with potential risk of infection. Consequently, the test is reserved for cases in which the diagnosis remains unclear.

X-ray images (normally during weightbearing) can be obtained to rule out other conditions or to see if the patient also has osteoarthritis. The menisci themselves cannot be visualised with plain radiographs. If the diagnosis is not clear from the history and examination, the menisci can be imaged with magnetic resonance imaging (an MRI scan). This technique has replaced previous arthrography, which involved injecting contrast medium into the joint space. In straightforward cases, knee arthroscopy allows quick diagnosis and simultaneous treatment. Recent clinical data shows that MRI and clinical testing are comparable in sensitivity and specificity when looking for a meniscal tear.

Musculoskeletal ultrasound has been advocated by experienced practitioners, avoiding the radiation of X-ray and the expense of MRI while demonstrating comparable accuracy to MRI for identifying and measuring the size of full-thickness and partial-thickness rotator cuff tears. This modality can also reveal the presence of other conditions that may mimic rotator cuff tear at clinical examination, including tendinosis, calcific tendinitis, subacromial subdeltoid bursitis, greater tuberosity fracture, and adhesive capsulitis. However, MRI provides more information about adjacent structures in the shoulder such as the capsule, glenoid labrum muscles and bone and these factors should be considered in each case when selecting the appropriate study.

The decisions involved in the repair of the Hill–Sachs lesion are complex. First, it is not repaired simply because of its existence, but because of its association with continuing symptoms and instability. This may be of greatest importance in the under-25-year-old and in the athlete involved in throwing activities. The Hill-Sachs role in continuing symptoms, in turn, may be related to its size and large lesions, particularly if involving greater than 20% of the articular surface, may impinge on the glenoid fossa (engage), promoting further episodes of instability or even dislocation. Also, it is a fracture, and associated bony lesions or fractures may coexist in the glenoid, such as the so-called bony Bankart lesion. Consequently, its operative treatment may include some form of bony augmentation, such as the Latarjet or similar procedure. Finally, there is no guarantee that associated non-bony lesions, such as a Bankart lesion, SLAP tear, or biceps tendon injury, may not be present and require intervention.

Imaging diagnosis conventionally begins with plain film radiography. Generally, AP radiographs of the shoulder with the arm in internal rotation offer the best yield while axillary views and AP radiographs with external rotation tend to obscure the defect. However, pain and tenderness in the injured joint make appropriate positioning difficult and in a recent study of plain film x-ray for Hill–Sachs lesions, the sensitivity was only about 20%. i.e. the finding was not visible on plain film x-ray about 80% of the time.

By contrast, studies have shown the value of ultrasonography in diagnosing Hill–Sachs lesions. In a population with recurrent dislocation using findings at surgery as the gold standard, a sensitivity of 96% was demonstrated. In a second study of patients with continuing shoulder instability after trauma, and using double contrast CT as a gold standard, a sensitivity of over 95% was demonstrated for ultrasound. It should be borne in mind that in both those studies, patients were having continuing problems after initial injury, and therefore the presence of a Hill–Sachs lesion was more likely. Nevertheless, ultrasonography, which is noninvasive and free from radiation, offers important advantages.

MRI has also been shown to be highly reliable for the diagnosis of Hill-Sachs (and Bankart) lesions. One study used challenging methodology. First of all, it applied to those patients with a single, or first time, dislocation. Such lesions were likely to be smaller and therefore more difficult to detect. Second, two radiologists, who were blinded to the surgical outcome, reviewed the MRI findings, while two orthopedic surgeons, who were blinded to the MRI findings, reviewed videotapes of the arthroscopic procedures. Coefficiency of agreement was then calculated for the MRI and arthroscopic findings and there was total agreement ( kappa = 1.0) for Hill-Sachs and Bankart lesions.

A meniscal tear can be classified in various ways: by anatomic location, by proximity to blood supply, etc. Various tear patterns and configurations have been described. These include:

- Radial tears;

- Flap or parrot-beak tears;

- Peripheral, longitudinal tears;

- Bucket-handle tears;

- Horizontal cleavage tears; and

- Complex, degenerative tears.

These tears can then be further classified by their proximity to the meniscus blood supply, namely whether they are located in the “red-red,” “red-white,” or “white-white” zones.

The functional importance of these classifications, however, is to ultimately determine whether a meniscus is repairable. The repairability of a meniscus depends on a number of factors. These include:

- Age/strength

- Activity level

- Tear pattern

- Chronicity of the tear

- Associated injuries (anterior cruciate ligament injury)

- Healing potential

Laximetry is a reliable technique for diagnosing a torn anterior cruciate ligament.

The MRI is perhaps the most used technique for diagnosing the state of the Anterior Cruciate Ligament but it not always the most reliable. In some cases the Anterior Cruciate Ligament can indeed not be seen because of the blood surrounding it.

Although strains are not restricted to athletes and can happen while doing everyday tasks, however, people who play sports are more at risk for developing a strain. It should also be noted that it is common for an injury to develop when there is a sudden increase in duration, intensity, or frequency of an activity.

Diagnosis of tendinitis and bursitis begins with a medical history and physical examination. X rays do not show tendons or the bursae but may be helpful in ruling out bony abnormalities or arthritis. The doctor may remove and test fluid from the inflamed area to rule out infection.

Ultrasound scans are frequently used to confirm a suspected tendinitis or bursitis as well as rule out a tear in the rotator cuff muscles.

Impingement syndrome may be confirmed when injection of a small amount of anesthetic (lidocaine hydrochloride) into the space under the acromion relieves pain.

Pain is perceived on shoulder motion, especially on certain movements. Often a crossover arm test is utilized in diagnosis because this compresses the AC joint, exacerbating the symptoms. X-rays of the shoulder joint may show either arthritic changes of the ac joint or osteolysis.

Following inspection and determination of the extent of injury, the basic labrum repair is as follows.

- The glenoid and labrum are roughened to increase contact surface area and promote re-growth.

- Locations for the bone anchors are selected based on number and severity of tear. A severe tear involving both SLAP and Bankart lesions may require seven anchors. Simple tears may only require one.

- The glenoid is drilled for the anchor implantation.

- Anchors are inserted in the glenoid.

- The suture component of the implant is tied through the labrum and knotted such that the labrum is in tight contact with the glenoid surface.

There is evidence in literature to support both surgical and non-surgical forms of treatment. In some, physical therapy can strengthen the supporting muscles in the shoulder joint to the point of reestablishing stability.

Surgical treatment of SLAP tears has become more common in recent years. The success rate for repairing isolated SLAP tears is reported between 74-94%. While surgery can be performed as a traditional open procedure, an arthroscopic technique is currently favored being less intrusive with low chance of iatrogenic infection.

Associated findings within the shoulder joint are varied, may not be predictable and include:

- SLAP lesion – labrum/glenoid separation at the tendon of the biceps muscle

- Bankart lesion – labrum/glenoid separation at the inferior glenohumeral ligament

- Biceps Tendon - exclusion of pulley injury

- Bone – glenoid, humerus — injury or degenerative change involving joint surface

- Anatomical variants — sublabral foramen, Buford Complex

Although good outcomes with SLAP repair over the age of 40 are reported, both age greater than 40 and Workmen's Compensation status have been noted as independent predictors of surgical complications. This is particularly so if there is an associated rotator cuff injury. In such circumstances, it is suggested that labral debridement and biceps tenotomy is preferred.

SLAP (Superior Labral Tear, Anterior to Posterior)

- "Type 1"

- Fraying of Superior Labrum

- Biceps Anchor Intact

- "Type 2"

- Superior Labrum detached

- Detachment of the Biceps Anchor

- "Type 3"

- Bucket Handle type tear of Superior Labrum

- Biceps Anchor INTACT

- "Type 4"

- Bucket Handle tear of Superior Labrum

- Extension of tear in Biceps Tendon

- Part of Biceps Anchor still INTACT

After an anterior shoulder dislocation, the risk of a future dislocation is about 20%. This risk is greater in males than females.

No non-invasive tests are currently able to diagnose articular cartilage damage. Additionally, symptoms vary considerably from person to person. Or as Dr. Karen Hambly stated:

MRI-scans are becoming more valuable in the analysis of articular cartilage but their use is still expensive and time consuming. X-rays show only bone injuries and are therefore not very helpful in diagnosing cartilage damage, especially not in early stages. The best tool for diagnosing articular damage is the use of arthroscopy.

Prompt medical treatment should be sought for suspected dislocation.

Usually, the shoulder is kept in its current position by use of a splint or sling. A pillow between the arm and torso may provide support and increase comfort. Strong analgesics are needed to allay the pain of a dislocation and the distress associated with it.

The ulnar collateral ligament is an important stabilizer of the thumb. Thumb instability resulting from disruption of the UCL profoundly impairs the overall function of the involved hand. Because of this, it is critical that these injuries receive appropriate attention and treatment.

In most cases of a complete tear, the aponeurosis of the adductor pollicis muscle may be interposed between the bones of the MCP joint and the torn ligament. When this condition (referred to as a Stener lesion) occurs, the adequate healing of the tear is prevented altogether. For a Stener lesion to occur, a complete tear of the ulnar collateral ligament must be present. However, the Stener lesion can occur even in the absence of a tear of the accessory collateral ligament or volar plate. The Stener lesion is present in more than 80% of complete ruptures of the UCL of the thumb.

When approaching this type of injury, the physician must first determine whether there is an incomplete rupture (or sprain) of the UCL, or a complete rupture. If the UCL is completely disrupted, the physician must then determine whether there is interposition of the adductor aponeurosis (Stener lesion), or simply a complete rupture of the UCL with anatomic or near-anatomic position. Radiographs are helpful in determining the possible presence of an avulsion fracture of the proximal phalanx insertion site of the ulnar collateral ligament. Stress examination, or one done under fluoroscopic guidance, can help determine the integrity of the ligament.

Most gamekeeper's thumb partial injuries are treated by simply immobilizing the joint in a thumb spica splint or a modified wrist splint and allowing the ligament to heal. However, near total or total tears of the UCL may require surgery to achieve a satisfactory repair, especially if accompanied by a Stener lesion.

The International Cartilage Repair Society has set up an arthroscopic grading system by which cartilage defects can be ranked:

- grade 0: (normal) healthy cartilage

- grade 1: the cartilage has a soft spot, blisters, or superficial wear

- grade 2: minor tears of less than one-half the thickness of the cartilage layer

- grade 3: lesions have deep crevices of more than one-half the thickness of the cartilage layer

- grade 4: the cartilage tear is full thickness and exposes the underlying (subchondral) bone

Doctors will often also measure the size of each defect. Defects smaller than 2 cm, for example, are considered to be small. It is also important to remember that although the amount of damage is an important factor, the location of the defect(s) can also influence the symptoms you are getting in terms of pain and function and their repair options available.

In contrast to popular perception, pain is not a good indicator for determining the extent of articular cartilage damage. One person can have severe pain with a single small defect while another person can have very little pain with several large full thickness defects.

Since articular cartilage does not have a blood supply and chondrocytes (cells in articular cartilage) have limited mobility, the articular cartilage has very limited ability to heal itself. If left untreated, the cartilage lesions will gradually worsen and the grade of the lesion or defect will increase.

Diagnosis is by examination. A Baker's cyst is easier to see from behind with the patient standing with knees fully extended. It is most easily palpated (felt) with the knee partially flexed. Diagnosis is confirmed by ultrasonography, although if needed and there is no suspicion of a popliteal artery aneurysm then aspiration of synovial fluid from the cyst may be undertaken with care. An MRI image can reveal presence of a Baker's cyst.

An infrequent but potentially life-threatening complication, which may need to be excluded by blood tests and ultrasonography, is a deep vein thrombosis (DVT). Quick assessment of the possibility of DVT may be required where a Baker's cyst has compressed vascular structures, causing leg edema, as this sets up conditions for a DVT to develop.

A burst cyst commonly causes calf pain, swelling and redness that may mimic thrombophlebitis.

The first-line treatment for a muscular strain in the acute phase include five steps commonly known as P.R.I.C.E.

- Protection: Apply soft padding to minimize impact with objects.

- Rest: Rest is necessary to accelerate healing and reduce the potential for re-injury.

- Ice: Apply ice to induce vasoconstriction, which will reduce blood flow to the site of injury. Never ice for more than 20 minutes at a time.

- Compression: Wrap the strained area with a soft-wrapped bandage to reduce further diapedesis and promote lymphatic drainage.

- Elevation: Keep the strained area as close to the level of the heart as is possible in order to promote venous blood return to the systemic circulation.

Immediate treatment is usually an adjunctive therapy of NSAID's and Cold compression therapy. Controlling the inflammation is critical to the healing process. Cold compression therapy acts to reduce swelling and pain by reducing leukocyte extravasation into the injured area. NSAID's such as Ibuprofen/paracetamol work to reduce the immediate inflammation by inhibiting Cox-1 & Cox-2 enzymes, which are the enzymes responsible for converting arachidonic acid into prostaglandin. However, NSAIDs, including aspirin and ibuprofen, affect platelet function (this is why they are known as "blood thinners") and should not be taken during the period when tissue is bleeding because they will tend to increase blood flow, inhibit clotting, and thereby increase bleeding and swelling. After the bleeding has stopped, NSAIDs can be used with some effectiveness to reduce inflammation and pain.

A new treatment for acute strains is the use of platelet rich plasma (PRP) injections which have been shown to accelerate recovery from non surgical muscular injuries.

It is recommended that the person injured should consult a medical provider if the injury is accompanied by severe pain, if the limb cannot be used, or if there is noticeable tenderness over an isolated spot. These can be signs of a broken or fractured bone, a sprain, or a complete muscle tear.

"Any finger injury that is sustained by a young adolescent (12–16) should be seen by a physician and have x-rays performed. These skeletally immature athletes are very susceptible to developing debilitating joint arthritis later in adulthood."

A study containing 100 consecutive patients with a recent anterior cruciate ligament injury were examined with respect to type of sports activity that caused the injury. Of the 100 consecutive ACL injuries, there were also 53 medial collateral ligament injuries, 12 medial, 35 lateral and 11 bicompartmental meniscal lesions. 59/100 patients were injured during contact sports, 30/100 in downhill skiing and 11/100 in other recreational activities, traffic accidents or at work.

An associated medial collateral ligament tear was more common in skiing (22/30) than during contact sports (23/59), whereas a bicompartmental meniscal lesion was found more frequently in contact sports (9/59) than in skiing (0/30). Weightbearing was reported by 56/59 of the patients with contact sports injuries whereas 8/30 of those with skiing injuries. Non-weightbearing in the injury situation led to the same rate of MCL tears (18/28) as weightbearing (35/72) but significantly more intact menisci (19/28 vs 23/72). Thus, contact sports injuries were more often sustained during weightbearing, with a resultant joint compression of both femuro-tibial compartments as shown by the higher incidence of bicompartmental meniscal lesions. The classic "unhappy triad" was a rare finding (8/100) and Fridén T, Erlandsson T, Zätterström R, Lindstrand A, and Moritz U. suggest that this entity should be replaced by the "unhappy compression injury".

About 25% of people over the age of 50 experience knee pain from degenerative knee diseases.

Knee MRIs should be avoided for knee pain without symptoms or effusion, unless there are non-successful results from a functional rehabilitation program.

Dead arm syndrome starts with repetitive motion and forces on the posterior capsule of the shoulder. The posterior capsule is a band of fibrous tissue that interconnects with tendons of the rotator cuff of the shoulder. Four muscles and their tendons make up the rotator cuff. They cover the outside of the shoulder to hold, protect and move the joint.

Overuse can lead to a buildup of tissue around the posterior capsule called hypertrophy. The next step is tightness of the posterior capsule called posterior capsular contracture. This type of problem reduces the amount the shoulder can rotate inwardly.

Over time, with enough force, a tear may develop in the labrum. The labrum is a rim of cartilage around the shoulder socket to help hold the head of the humerus (upper arm) in the joint. This condition is called a superior labrum anterior posterior (SLAP) lesion. The final outcome in all these steps is the dead arm phenomenon.

The shoulder is unstable and dislocation may come next. Dead arm syndrome will not go away on its own with rest—it must be treated. If there is a SLAP lesion, then surgery is needed to repair the problem. If the injury is caught before a SLAP tear, then physical therapy with stretching and exercise can restore it.

It is common among baseball pitchers as they age, and it can also occur with quarterbacks in football and handball players also as they age.