Orthopedics Hyperguide Review | Dr Hutaif General Ortho -...

A significant incidence of cervical spine disease exists among patients with rheumatoid arthritis. Surgeons should consider obtaining cervical spine flexion-extension views to evaluate for potential instability prior to the patient undergoing anesthesia

Although neurologiCdysfunction, soft tissue laxity, and loosening due to implant failure or infection contribute to THA instability, component malposition is the leading cause of dislocation from surgical technique

Malposition leads to limited range of motion, impingement, and increased bearing and fretting wear. Fibrous ingrowth is most commonly a consequence of inadequate fixation and excessive micromotion

Excessive anteversion leads to anterior dislocation due to posterior component impingement. This most commonly occurs through extension and external rotation of the lower extremity. Excessive anteversion has little or no direct effect on medialization of the cup, leg length disparity, or premature osteolysis

With adequate exposure, compensation for soft tissue variance is accomplished. Fracture is uncommon, as is gross motion between implant and bone. Provided the guide is used correctly, there is no appreciable motion between it and the implant. Changes in pelviCand patient position, however, will render the mechanical guide inaccurate

Edge loading, superior dislocation or subluxation, linear polyethylene wear and resultant premature osteolysis may all result from an excessively abducted cup. Superior cup migration is most commonly a consequence of a cup with low abduction

Although implant failure, infection, and fracture occur with extended lifetime of hip implants, polyethylene wear debris and eventual aseptiCloosening are the most commonly recognized limitation in the survival of total hip arthroplasty. Limited range of motion is a less common presentation for implant failure in the hip

Metal ions generated, although of unknown consequence, are not considered an advantage. Metal-on-metal bearings have not been shown to demonstrate a lower infection rate or lower cost, nor do they have increased wetability (commonly associated with ceramiCbearings). The metal-on-metal implants allow larger head and cup diameter, thus providing improved range of motion with lower risk for dislocation

All of the above variables can be modified during the planning and placement of hip resurfacing with the exception of leg length. Due to the anatomiCreproduction of the cup center and femoral head anatomy, modifications on leg length cannot be performed with hip resurfacing

Among outcome studies, the most common failure mechanism for hip resurfacing is femoral neck fracture. Dislocation, infection, and loosening have been reported at lower rates

Excessive cyst formation in the femoral head, documented osteoporosis, severe developmental hip dysplasia, and advanced osteonecrosis are contraindications to hip resurfacing. Previous femoral neck fracture, however, if healed, does not provide a risk for femoral neck fracture

Initial stem design of cementless stems included patch porous coating. This design feature resulted in wear particle migration distally, causing inevitable aseptiCloosening. The remaining options were not instrumental in cementless stem loosening

Of the choices listed, only radiolucency provides evidence of acetabular loosening. CystiClesions, known as osteolysis, may exist without the presence of loosening

Bone scan studies are sensitive, but poorly specific. The differential includes recent implantation (up to 1 year), osteolysis, loosening, fracture, and infection. Mature heterotopiCossification is generally cold on bone scan

Studies have shown CT scans to be the most thorough means of assessing bone loss in the presence of osteolysis in the pelvis

Ideal values of micromotion that stimulate bone ingrowth are 28 microns to 150 microns. Values greater than 150 microns are associated with fibrous ingrowth

Osteolysis, osteopenia, and aggressive cortical reaming have been reported as potential risk factors for the development of a postoperative periprosthetiCfracture

The radial nerve is the most frequently injured nerve at the time of a periprosthetiCfracture. There continues to be debate as to whether the presence of a radial nerve injury constitutes a reason for revision surgery

In a study by Kumar and colleagues, the mean time to healing among patients who underwent surgery was 278 days (range, 135 to 558 days)

According to the classification, a type A fracture is one at the tip of the prosthesis and extends proximally. Type B fractures occur at the prosthesis tip without extension or with a minimal amount of proximal extension and a variable amount of distal extension. Type Cfractures are distal to the tip of prosthesis

In patients with a type CperiprosthetiCfracture (distal to the tip of the prosthesis) and a well-fixed humeral component, the injury can be treated similar to a closed humerus fracture

The axillary nerve is located approximately 5 cm from the lateral border of the acromion. Correct Answer: 5 cm

The musculocutaneous nerve enters the coracobrachialis muscle 4 cm to 8 cm distal to the tip of the coracoid process. Correct Answer: Musculocutaneous nerve

The anteromedial approach involves taking the deltoid down off the clavicle and anterior acromion. Correct Answer: Anteromedial approach

The origin of the deltoid on the clavicle is J-shaped and extends from the midline on the superior aspect of the clavicle around the front of the clavicle to the inferior portion of the anterior aspect of the clavicle. Full-thickness fascial flaps must be obtained when the deltoid is released from the clavicle.

The anteromedial approach facilitates shoulder arthroplasty in patients with severe scarring, distortion of anatomy, as well as patients with frail bone and soft tissue.

Corrective osteotomy is an option for surgeons who must treat a patient with a proximal humerus malunion. This option may best be considered in a young, active patient who has no radiographiCevidence of degenerative changes in the glenohumeral joint. In an older, less active patient who has evidence of degenerative joint disease, a shoulder arthroplasty may be a more suitable and definitive procedure.
Patients with proximal humerus malunions often present with complaints of pain as well as loss of function. Frequently, patients have impingement-type pain due to a malunion of the greater tuberosity with an associated decrease in the subacromial space. Some of the contraindications to a corrective osteotomy include a massive irreparable rotator cuff tear, significant degenerative changes of the articular surfaces, avascular necrosis, active infection, or nerve injury.

Boileau and colleagues reported that the most significant factor affecting results of shoulder arthroplasty for malunion was the need for greater tuberosity osteotomy.

ArthroscopiCacromioplasty has been reported by Beredjiklian and colleagues. The procedure essentially increases the available subacromial space to improve impingement of the greater tuberosity against the acromion.

Antuna and colleagues reported that 10 of 24 shoulders that had a greater tuberosity osteotomy had a complication related to tuberosity nonunion, malunion, or resorption.

Implantation of the humeral component in slight varus or valgus to accommodate the tuberosity malunion was not associated with an increased incidence of humeral component loosening. In addition, humeral components with a modified curvature in the stem have been used with success.

A lesser tuberosity osteotomy allows bone-to-bone healing as well as facilitates glenoid exposure. Moreover, disruption of the anterior repair is immediately evident on postoperative radiographs with the appearance of a displaced lesser tuberosity.

An MRI allows a surgeon to gain a greater understanding of the size of the rotator cuff tear, the specifiClocation of the tear, and the degree of fat infiltration within the tendon.

Many patients with a rotator cuff tear following shoulder arthroplasty may develop anterior-superior escape. Once this pattern develops, it may be difficult to restore stability with attempted rotator cuff repair alone. In this setting, one may consider the use of a reverse arthroplasty, particularly if the patient is older than 70 years of age.

The reported frequency of postoperative rotator cuff tears following shoulder arthroplasty is 3% to 4%. Correct Answer: 3% to 4%

ArthroscopiCacromioplasty has been used for the treatment of impingement following shoulder arthroplasty. It has the potential benefits of less tissue disruption, more rapid recovery, as well as increased ability to address intra-articular pathology compared to an open procedure.

Methotrexate has been identified as a risk for development of a nerve injury after shoulder arthroplasty. Correct Answer: Methotrexate

The most common reason for a nerve deficit following shoulder arthroplasty is a temporary neuropraxia due to stretch. Correct Answer: Temporary neuropraxia due to stretch

The deltopectoral approach has been identified as a risk for development of a nerve injury after shoulder arthroplasty. Correct Answer: Deltopectoral

The most common nerve that has been found to have a deficit after shoulder arthroplasty is the axillary nerve. Correct Answer: Axillary nerve

The reported incidence of nerve injuries following shoulder arthroplasty is 4.3%. Correct Answer: Between 4% and 5%

Painful glenoid arthritis represents the most common reason for revision surgery for hemiarthroplasties. Correct Answer: Glenoid arthritis

Among patients who have undergone prior instability surgery, it is important to review prior operative reports to determine the specifiCinstability procedure performed. This will facilitate safe and effective soft tissue releases and balancing at the time of shoulder arthroplasty.

Overall, the survival rate for shoulder arthroplasty after prior instability surgery was only 61% at 10 years. Correct Answer: Less than 65%

Research has shown that shoulder arthroplasty for postcapsulorraphy arthritis has inferior results and a higher revision rate compared to shoulder arthroplasty for osteoarthritis.

Shoulder arthroplasty for postcapsulorraphy arthritis provides pain relief and improved motion. However, shoulder arthroplasty in these young patients is associated with a high rate of unsatisfactory results and revision surgery due to glenoid arthritis, component failure, or instability.

Zumstein and colleagues identified a wide lateral extension of the acromion as a risk factor for developing a recurrent rotator cuff tear.

Ultrasound has become increasingly popular as a tool to evaluate rotator cuff tears. Some of the advantages of ultrasound include the fact that it is easily portable and less expensive than MRI. Additionally, unlike a computed tomography arthrogram, no injection is required. Another interesting aspect of ultrasound is that it allows dynamiCevaluation of the rotator cuff. Several research studies have shown the promise of using ultrasound to follow the status of rotator cuff after repair.