Hombro
LuxaciĆ³n
Medio
Lateral
Osteocondritis disecante: aspecto caudal de la cabeza humeral
Tenosinovitis del bĆceps
Inestabilidad glenohumeral medial
TendinopatĆa del supraespinoso
Contractura del mĆŗsculo infraespinoso
Fractura
LuxaciĆ³n
Medio
Lateral
Osteocondritis disecante
FiliaciĆ³n
Razas - Perros de razas grandes y gigantes
GƩnero: los hombres estƔn predispuestos, pero las mujeres tambiƩn se ven afectadas.
Edad: generalmente se observa entre los 4 y los 9 meses de edad.
EtiologĆa: la osificaciĆ³n endocondral anormal de las capas profundas del cartĆlago articular da como resultado Ć”reas focales de cartĆlago engrosado que son propensas a lesionarse. En ausencia de estrĆ©s excesivo, la lesiĆ³n puede curar. Sin embargo, una mayor tensiĆ³n en el cartĆlago puede resultar en un colgajo de cartĆlago. Esta afecciĆ³n se denomina osteocondritis disecante (TOC).
Historia
Cojera leve a moderada, disminuciĆ³n de la actividad.
Hallazgos clĆnicos
Leve cojera, un trofeo de los mĆŗsculos de las extremidades anteriores a moderada, p ain puede ser obtenido con la extensiĆ³n del hombro
DiagnĆ³sticos
Generalmente el diagnĆ³stico se sospecha en el examen ortopĆ©dico y se confirma con una radiografĆa lateral de la articulaciĆ³n del hombro.
Opciones de tratamiento
ExtracciĆ³n del colgajo de cartĆlago con artrotomĆa o artroscopia, legrado del hueso subcondral, cambio de dieta a una dieta de crecimiento de razas grandes, medicaciĆ³n antiinflamatoria no esterodal, rehabilitaciĆ³n
Tenosinovitis del bĆceps
FiliaciĆ³n
Razas: generalmente perros de razas grandes
GĆ©nero: sin predilecciĆ³n por gĆ©nero
Edad: se observa con frecuencia en perros de mediana a mayor edad.
EtiologĆa: proceso degenerativo del tendĆ³n y la vaina del tendĆ³n del mĆŗsculo bĆceps braquial.
Historia
Cojera por soporte de peso variable, a menudo tiene cojera inicial, mejora y luego empeora nuevamente
Hallazgos clĆnicos
Cojera de carga variable. La flexiĆ³n de la articulaciĆ³n del hombro con la extensiĆ³n simultĆ”nea de la articulaciĆ³n del codo aumenta la tensiĆ³n en el tendĆ³n del bĆceps cuando cruza el surco bicipital, lo que produce malestar. AdemĆ”s, puede haber dolor a la palpaciĆ³n directa del surco bicipital de la cara proximomedial del hĆŗmero.
DiagnĆ³sticos
Las radiografĆas pueden demostrar mineralizaciĆ³n del tendĆ³n bicipital, entesiofitos en el surco intertubercular u otros cambios degenerativos. El diagnĆ³stico puede ser difĆcil y, a veces, se realiza mediante ecografĆa de diagnĆ³stico, resonancia magnĆ©tica u observaciĆ³n durante la artroscopia.
Opciones de tratamiento
El tratamiento conservador implica reposo e inyecciĆ³n de terapias biolĆ³gicas, como plasma rico en plaquetas o cĆ©lulas madre, en la articulaciĆ³n del hombro que se comunica con la vaina del tendĆ³n del bĆceps. TambiĆ©n se han realizado inyecciones de corticosteroides. El ultrasonido terapĆ©utico de modo pulsado y el lĆ”ser terapĆ©utico tambiĆ©n se pueden usar sobre el tendĆ³n. TambiĆ©n se prescriben medicamentos antiinflamatorios no esteroideos (AINE) orales y crioterapia.
En los casos que no responden a las medidas conservadoras, se realiza la liberaciĆ³n quirĆŗrgica del tendĆ³n del bĆceps sola o la liberaciĆ³n quirĆŗrgica y la reinserciĆ³n del hĆŗmero proximal.
Inestabilidad glenohumeral medial
FiliaciĆ³n
Razas: cualquier raza es susceptible
GĆ©nero: sin predilecciĆ³n por gĆ©nero
Edad: cualquier edad, mĆ”s comĆŗn en perros de mediana edad.
EtiologĆa: cada vez mĆ”s reconocido como una fuente de cojera en las extremidades anteriores, quizĆ”s como resultado de la creciente apariciĆ³n de actividades deportivas que requieren giros y saltos rĆ”pidos, y tambiĆ©n por el cambio de peso a las extremidades anteriores como resultado de las condiciones de las extremidades pĆ©lvicas. Puede ocurrir daƱo del ligamento glenohumeral medial, tendĆ³n subescapular y cĆ”psula articular .
Historia
Los perros pueden tener cojera de leve a severa, que puede ser aguda con un trauma repentino. Alternativamente, los perros pueden mostrar cojera que varĆa en severidad a medida que la condiciĆ³n se vuelve mĆ”s comĆŗn. Los perros de trabajo y deportivos que ejercen una tensiĆ³n de torsiĆ³n en la articulaciĆ³n del hombro pueden estar predispuestos, asĆ como los perros con afecciones bilaterales de las extremidades pĆ©lvicas que provocan el desplazamiento de las fuerzas de soporte de peso a las extremidades anteriores.
Hallazgos clĆnicos
Cojera y abducciĆ³n excesiva de la articulaciĆ³n del hombro mientras el hombro estĆ” completamente extendido. El dolor tambiĆ©n estĆ” presente al final de la abducciĆ³n.
DiagnĆ³sticos
La resonancia magnĆ©tica puede revelar daƱo al ligamento glenohumeral medial o al tendĆ³n subescapular, pero con frecuencia se subestima la gravedad de la lesiĆ³n. Aunque se ha utilizado el ultrasonido, muchos artefactos como resultado de la dificultad para colocar la sonda en forma perpendicular hacen que la interpretaciĆ³n sea sospechosa. La evaluaciĆ³n artroscĆ³pica es el estĆ”ndar de oro para evaluar el tipo y la gravedad de la lesiĆ³n.
Opciones de tratamiento
Los casos leves pueden tratarse con tratamiento de ondas de choque extracorpĆ³reas, cojeos para evitar la abducciĆ³n y reposo durante 4-8 semanas. En casos graves o que no responden, el hombro se puede estabilizar con un procedimiento de cuerda floja o con anclajes de tejido y sutura, seguido de cojeos colocados durante 4 semanas. La rehabilitaciĆ³n comienza lentamente, con caminatas con correa y ejercicios suaves de rango de movimiento. Los ejercicios de fortalecimiento de los mĆŗsculos de soporte del hombro pueden iniciarse de 6 a 8 semanas despuĆ©s de la cirugĆa.
TendinopatĆa del supraespinoso
FiliaciĆ³n
Razas: perros de razas medianas y grandes
GĆ©nero: sin predilecciĆ³n por gĆ©nero
Edad: generalmente de mediana edad a mayor
EtiologĆa: a menudo se asocia con actividades laborales o deportivas con tensiones de torsiĆ³n en la articulaciĆ³n del hombro que provocan daƱos en el tendĆ³n.
Historia
Cojera leve a moderada, que a veces aumenta y disminuye en la naturaleza. A veces, los perros tienen una apariciĆ³n repentina de cojera.
Hallazgos clĆnicos
Cojera leve a moderada. Dolor en la inserciĆ³n del tendĆ³n del supraespinoso en el tubĆ©rculo mayor del hĆŗmero, especialmente cuando el hombro se flexiona y se gira internamente para aumentar las fuerzas de tracciĆ³n sobre el tendĆ³n.
DiagnĆ³sticos
La ecografĆa es la prueba de diagnĆ³stico generalmente mĆ”s beneficiosa. Las radiografĆas, especialmente una vista del horizonte de la inserciĆ³n del tendĆ³n, pueden mostrar mineralizaciĆ³n del tendĆ³n.
Opciones de tratamiento
El tratamiento mĆ©dico incluye reposo, AINE, crioterapia y ejercicios de rango de movimiento pasivo (PROM). La ecografĆa terapĆ©utica se ha utilizado en humanos para tratar la calcificaciĆ³n y puede ser beneficiosa para los perros. Las terapias biolĆ³gicas que incluyen plasma rico en plaquetas o cĆ©lulas madre inyectadas en tejido enfermo suelen ser Ćŗtiles. En algunos casos, se puede realizar la escisiĆ³n quirĆŗrgica del tejido mineralizado. En casos graves, se puede realizar la reinserciĆ³n del tendĆ³n con anclajes de tejido. DespuĆ©s de la cirugĆa, se puede aplicar un vendaje de flexiĆ³n del carpo durante 2 semanas para evitar el soporte de peso. La actividad estĆ” limitada por 2 a 3 semanas adicionales.
Contractura del mĆŗsculo infraespinoso
FiliaciĆ³n
Razas: generalmente ocurre en perros deportivos y de trabajo.
GĆ©nero: sin predilecciĆ³n por gĆ©nero
Edad: perros maduros
EtiologĆa: se desconoce la etiologĆa exacta, pero puede ser una forma de lesiĆ³n compartimental del mĆŗsculo infraespinoso. Con el tiempo, el mĆŗsculo daƱado es reemplazado por tejido fibroso y da como resultado los cambios fĆsicos y de la marcha caracterĆsticos.
Historia
La cojera puede ocurrir en perros activos despuĆ©s de un perĆodo de actividad intensa. Inicialmente, la cojera puede desaparecer, seguida por los hallazgos caracterĆsticos de la marcha y las extremidades varias semanas despuĆ©s.
Hallazgos clĆnicos
Los perros con contractura infraespinoso mantienen su extremidad distal en abducciĆ³n, con el pie en rotaciĆ³n externa y el codo en rotaciĆ³n hacia el pecho. Los perros tienden a remar la pierna cuando caminan, "voltear" el carpo al final de la fase de balanceo de la marcha y no son capaces de extender por completo la articulaciĆ³n escapulohumeral.
DiagnĆ³sticos
Opciones de tratamiento
Si se identifica muy pronto, la rehabilitaciĆ³n fĆsica posiblemente pueda prevenir una mayor contractura. El tratamiento quirĆŗrgico suele ser necesario e implica la secciĆ³n transversal del tejido fibroso y el tendĆ³n para liberar el tejido afectado. DespuĆ©s de la operaciĆ³n, se debe permitir que el perro soporte todo su peso tan pronto como sea posible y se le deben administrar ejercicios PROM suaves y sin dolor en el hombro, el codo y el carpo varias veces al dĆa para mantener el ROM y promover la alineaciĆ³n normal de los tejidos en curaciĆ³n. Debe evitarse la actividad excesiva durante las primeras semanas para evitar daƱo tisular y la recurrencia del tejido fibroso. Se deben utilizar ejercicios de acondicionamiento general para la extremidad para que los mĆŗsculos vuelvan gradualmente a su tamaƱo y fuerza normales.
Fractura
FiliaciĆ³n
Razas: cualquier raza
GĆ©nero: sin predilecciĆ³n por gĆ©nero
Edad: cualquier edad
EtiologĆa - Traum a. Muchos de los casos o CCur como resultado de un trauma del automĆ³vil. Debido a esto y al hecho de que la extremidad anterior estĆ” afectada, es importante una evaluaciĆ³n cuidadosa de las estructuras torĆ”cicas para detectar arritmias cardĆacas, neumotĆ³rax, edema pulmonar o hernia diafragmĆ”tica.
Historia
A menudo, los propietarios presencian un trauma, como una caĆda, un golpe de automĆ³vil u otro evento traumĆ”tico repentino que resulta en la apariciĆ³n repentina de una cojera severa.
Hallazgos clĆnicos
Las fracturas de la articulaciĆ³n del hombro provocan dolor durante la manipulaciĆ³n y crepitaciĆ³n.
DiagnĆ³sticos
Las radiografĆas generalmente son diagnĆ³sticas, pero la evaluaciĆ³n por TC puede brindar detalles adicionales.
Opciones de tratamiento
La mayorĆa de las fracturas de la articulaciĆ³n del hombro requieren fijaciĆ³n interna para restaurar la anatomĆa de la articulaciĆ³n y minimizar el desarrollo de artritis.
Luxation
Medial - much more common
Lateral
Signalment
Breeds – Toy and miniature breeds may have congenital shoulder luxation. Any breed may have a shoulder luxation due to trauma, especially larger dogs
Gender – No known gender predilection
Age – Congential shoulder luxation generally first noted from 3 to 9 months of age. Traumatic causes can occur at any age.
Etiology - Congenital causes may be due to abnormal flattening of the head of the humerus and abnormal shape of the glenoid. Occassionally there may be bilateral congenital shoulder luxations. Trauma may result in traumatic shoulder luxation. Patients should also be evaluated for thoracic trauma and other fractures of the forelimb.
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History
Moderate to severe lameness, may hold forelimb in a flexed nonweight-bearing position
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Clinical Findings
Moderate to severe lameness, atrophy of the forelimb muscles, hypertrophy of the pelvic limb muscles, abnormal position of the greater tubercle of the humerus relative to the acromial process of the scapula, with the acromial process located more lateral in cases of medial shoulder luxation.
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Diagnostics
Generally diagnosis suspected on orthopedic exam and confirmed with radiographs of the shoulder joint.
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Lateral view of a medial shoulder luxation. Note the head of the humerus is located proximal to the glenoid.
Cranial caudal view of a medial shoulder luxation. Note the head of the humerus is located medial to the glenoid.
Treatment Options
Some congenital cases have been treated conservatively. These cases generally stabilize by one year of age and dogs are relatively comfortable. However, lameness and atrophy persist. Other options include excision arthroplasty of the humeral head followed by physical rehabilitation, and arthrodesis. Arthrodesis is generally a last option.
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For traumatic shoulder luxation, when the patient is stable, general anesthesia is administered to allow painfree manipulation during reduction. The leg is hung using an IV pole or other means for 10 minutes to fatigue muscles. Distraction is applied, and if the luxation is medial, the humeral head is pushed laterally while distracting. Shoulder luxations are usually relatively easy to reduce. If the luxation is medial, a Velpeau sling is applied. If the luxationis lateral, a Spica splint is applied. Coaptation is applied for 2 weeks, then restricted activity for 4-6 more weeks.
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Velpeau sling
Alternatively, surgical repair of shoulder luxation may be performed. Transposition of the biceps tendon has been used. With this technique, the biceps tendon is transposed to a more medial position so that tension applied by the transposed biceps tendon helps to keep the shoulder from re-luxating. Primary repair of the damaged tissues is difficult because they are often severely damaged and do not hold suture very well. Prosthetic capsule repair with screws, washers and suture have been used.
More recently, a tightrope procedure has been used. With this technique, tunnels are drilled in the proximal humerus and the neck of the scapula. Strong suture is passed through the tunnels, and the suture is anchored on both ends to maintain tension and prevent re-luxation.
Repair of medial shoulder luxation with a tightrope procedure. Note the toggle anchor on the lateral scapular neck and the button on the lateral proximal humerus. Suture is tightened to maintain reduction.
Osteochondritis Dissecans
Signalment
Breeds – Large and giant breed dogs
Gender – Males are predisposed, but females also affected
Age – Generally noted from 4 to 9 months of age
Etiology - Abnormal endochondral ossification of the deep layers of articular cartilage results in focal areas of thickened cartilage that are prone to injury. In the absence of excessive stress, the lesion may heal. However, further stress on the cartilage may result in a cartilage flap. This condition is termed osteochondritis dissecans (OCD).
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History
Mild to moderate lameness, decreased activity
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Clinical Findings
Mild to moderate lameness, atrophy of the forelimb muscles, pain may be elicited with extension of the shoulder
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Diagnostics
Generally diagnosis suspected on orthopedic exam and confirmed with a lateral radiograph of the shoulder joint.
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OCD lesion. Note the flattened area on the caudal head of the humerus. The flap has undergone mineralization and is visible, but they often are not visib because cartilage is radiolucent.
Treatment Options
Removal of cartilage flap with an arthrotomy or arthroscopy, curettage of subchondral bone, change diet to a large breed growth diet, nonsterodal anti-inflammatory medication, rehabilitation
Biceps tenosynovitis
Signalment
Breeds – Generally large breed dogs
Gender – No gender predilection
Age – Commonly seen in middle- to older-aged dogs
Etiology – Degenerative process of the tendon and tendon sheath of the biceps brachii muscle.
History
Variable weight bearing lameness, often have initial lameness, improves, then worsens again
Clinical Findings
Variable weight bearing lameness. Flexion of the shoulder joint with simultaneous extension of the elbow joint increases the tension on the biceps tendon as it crosses over the bicipital groove, resulting in discomfort. In addition, there may be pain on direct palpation of the bicipital groove of the proximomedial aspect of the humerus.
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Test for biceps tenosynovitis by simultaneously flexing the shoulder joint and extending the elbow to increase stress on the biceps tendon. Normally the antebrachium should be parallel with the spine. Pain prior to that suggests biceps tendon pain.
Diagnostics
Radiographs may demonstrate mineralization of the bicipital tendon, enthesiophytes in the intertubercular groove, or other degenerative changes. Diagnosis can be difficult and is sometimes made by diagnostic ultrasound, magnetic resonance imaging, or observation during arthroscopy.
Normal biceps tendon
Partially torn biceps tendon
Treatment Options
Conservative management involves rest and injection of biological therapies, such as platelet rich plasma or stem cells, into the shoulder joint which communicates with the biceps tendon sheath. Corticosteroid injections have also been performed. Pulsed mode therapeutic ultrasound and therapeutic laser may also be used over the tendon. Oral non-steroidal anti-inflammatory drugs (NSAIDs) and cryotherapy are also be prescribed.
In cases that fail to respond to conservative measures, surgical release of the biceps tendon alone, or surgical release and re-attachment to the proximal humerus are performed.
Medial glenohumeral instability
Signalment
Breeds – Any breed is susceptible
Gender – No gender predilection
Age – Any age, more common in middle-aged dogs
Etiology – Increasingly recognized as a source of forelimb lameness, perhaps as a result of increasing advent of sporting activities which require rapid turning and jumping, and also from shifting weight to the forelimbs as a result of pelvic limb conditions. Damage of the medial glenohumeral ligament, subscapularis tendon, and joint capsule may occur.
History
Dogs may have mild to severe lameness, which may be acute with sudden trauma. Alternatively, dogs may demonstrate lameness that varies in severity as the condition becomes more common. Working and sporting dogs that place torsional stress on the shoulder joint may be predisposed, as well as dogs with bilateral pelvic limb conditions that result in shifting weight bearing forces to the forelimbs.
Clinical Findings
Lameness and excessive abduction of the shoulder joint while the shoulder is fully extended. Pain is also present at the end of abduction.
Diagnostics
MRI may reveal damage to the medial glenohumeral ligament or subscapularis tendon, but frequently the severity of injury is underestimated. Although ultrasound has been used, many artifacts as a result of difficulty in placing the probe in a perpendicular fashion makes interpretation suspect. Arthroscopic evaluation is the gold standard of assessing the type and severity of injury.
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Testing for medial shoulder instability
It is important to fully extend the shoulder to tighten the medial glenuhumeral structures. Stabilize the scapula, and then abduct the humerus. There should be less than 30 degrees of abduction, and no pain at the end of abduction.
Treatment Options
Mild cases may be treated with extracorporeal shockwave treatment, hobbles to prevent abduction, and rest for 4-8 weeks. In unresponsive or severe cases, the shoulder may be stabilized with a tightrope procedure or tissue anchors and suture, followed by hobbles placed for 4 weeks. Rehabilitation begins slowly, with leash walk and gentle range of motion exercises. Strengthening exercises of the supporting muscles of the shoulder may be initiated 6-8 weeks after surgery.
Normal subscapularis and Medial Glenohumeral Ligament cranial portion
Longitudinal tear of Medial Glenohumeral Ligament cranial portion
Damaged subscapularis muscle with synovitis. Note normal cranial arm of medial glenohumeral ligament at the top of the image.
Lateral radiogaph following tightrope stabilization of medial shoulder instability
Cranial caudal view following tightrope stabilization of medial shoulder instability
Supraspinatus tendinopathy
Signalment
Breeds – Medium and large breed dogs
Gender – No gender predilection
Age – Generally middle aged to older
Etiology – Often associated with working or sporting activities with torsional stresses on the shoulder joint that result in damage to the tendon.
History
Mild to moderate lameness, sometimes waxing and waning in nature. Sometimes dogs have a sudden onset of lameness.
Clinical Findings
Mild to moderate lameness. Pain at the insertion of the supraspinatus tendon on the greater tubercle of the humerus, especially when the shoulder is flexed and internally rotated to increase tensile forces on the tendon.
Diagnostics
Ultrasound is the generally the most beneficial diagnostic test. Radiographs, especially a skyline view of the tendon insertion, may show mineralization of the tendon.
Treatment Options
Medical treatment includes rest, NSAIDs, cryotherapy, and passive range of motion (PROM) exercises. Therapeutic ultrasound has been used in humans to treat calcification, and may be beneficial for dogs. Biologic therapies including platelet rich plasma or stem cells injected into diseased tissue is often useful. Surgical excision of the mineralized tissue may be performed in some cases. Tendon reattachment with tissue anchors may be performed in severe cases. After surgery, a carpal flexion bandage may be applied for 2 weeks to prevent weight bearing. Activity is limited for an additional 2 to 3 weeks.
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Contracture of infraspinatus muscle
Signalment
Breeds – Generally occurs in sporting and working dogs
Gender – No gender predilection
Age – Mature dogs
Etiology – Exact etiology is unknown but it may be a form of compartmental injury to the infraspinatus muscle. Over time, the damaged muscle is replaced by fibrous tissue and results in the characteristic physical and gait changes.
History
Lameness may occur in active dogs after a period of strenuous activity. Initially the lameness may resolve, followed by the characteristic gait and limb findings several weeks later.
Clinical Findings
Dogs with infraspinatus contracture hold their distal extremity in abduction, with the foot externally rotated and the elbow rotated toward the chest. Dogs tend to paddle the leg when they walk, "flipping" the carpus at the end of the swing phase of gait and they are unable to fully extend the scapulohumeral joint.
Diagnostics
Treatment Options
If identified very early, physical rehabilitation may possibly prevent further contracture. Surgical management is usually necessary and involves transecting the fibrous tissue and tendon to release the affected tissue. Postoperatively, the dog should be allowed full weight bearing as soon as possible, and given gentle, pain-free PROM exercises to the shoulder, elbow, and carpus several times daily to maintain ROM and to promote normal alignment of the healing tissues. Excessive activity should be avoided in the first several weeks to avoid tissue damage and recurrence of fibrous tissue. General conditioning exercises for the limb, should be used to gradually return muscles to normal size and strength.
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Characteristic posture of a dog with infraspinatus muscle contracture. Note the internal rotation of the elbow and external rotation of the lower limb.
Fracture
Signalment
Breeds – Any breed
Gender – No gender predilection
Age – Any age
Etiology – Trauma. Many cases occur as a result of automobile trauma. Because of this and the fact that the forelimb is affected, careful evaluation of the thoracic structures is important to detect cardiac arrhythmias, pneumothorax, pulmonary edema, or diaphragmatic hernia.
History
Often owners witness trauma, such as a fall, hit by automobile, or other sudden traumatic event that results in sudden onset of severe lameness.
Clinical Findings
Fractures of the shoulder joint result in pain on manipulation and crepitation.
Diagnostics
Radiographs are generally diagnostic, but CT evaluation may give additional details.
Treatment Options
Most fractures of the shoulder joint require internal fixation to restore joint anatomy and minimize arthritis development.