Arthritis, the inflammation of one or more joints, can occur secondary to the result of trauma, infection, or age-related degeneration. Arthritis is the single most common cause of disability among older adults, with 40% of those over the age of 65 having symptomatic hip or knee arthritis.¹ No matter the cause, pain secondary to arthritis is usually progressive and can lead to a significant decrease in one’s ability to engage in daily activities and therefore in one’s overall quality of life. Although less common in patients under the age of 45, the incidence of osteoarthritis increases with each decade of life as shown in the incidence rates of hip and knee arthritis (Table 5-1). Treatments aim to reduce pain, improve quality of life, and prevent further joint damage. First-line treatments for patients with arthritis include nonsteroidal anti-inflammatory drugs (NSAIDs; Table 5-2), physical therapy, and weight loss for patients with BMI ≥ 25.²,³ Although the evidence on bracing for patients with knee arthritis is inconclusive, some patients may benefit from a valgus bracing for isolated medial compartment osteoarthritis to reduce pressure on the medial compartment of the knee.⁴ In patients that have continued pain despite these treatments, intra-articular glucocorticoid and/or hyaluronic acid injections are recommended. These injections reach their maximum effect at 2 weeks and can relieve pain for up to 6 months.⁵ Injections can be repeated every 3 months; however, even with continued administration, benefits may plateau after 2 years of therapy.

If these nonoperative treatments fail to control the pain and disability of arthritis, arthroplasty, surgical replacement of the articular surface of a joint with an artificial prosthesis, is indicated. Particularly due to people living active lives for longer periods of time, such joint replacements have become the most common orthopaedic procedures performed in the United States.⁶ However,
arthroplasty procedures should only be performed when the patient and physician feel that the pain in the affected joint is debilitating and that no other treatment will provide satisfactory relief.

The most common arthroplasty procedure is the total knee replacement (Figure 5-1), with over 700,000 operations performed yearly in the United States making it the third most performed operation.⁶ The knee joint comprises three compartments—lateral, medial, and patellofemoral. Damage to the cartilage lining in any of these compartments can cause severe pain with weight bearing that is often aggravated by climbing stairs or simply going from sitting to standing. As the damage continues, patients may develop bowing deformities or complain of instability. The cause of this damage to the cartilage lining is usually secondary to changes associated with osteoarthritis, but may also be seen in rheumatoid arthritis, avascular necrosis, or at the end stage of some congenital deformities. The majority of knee replacements performed are total knee replacements in that they involve resurfacing all three compartments of the joint: the lateral, medial, and patellofemoral compartments. However, in the case of isolated lateral or medial compartment disease, a unicompartmental
arthroplasty may be performed. Possible complications with total knee replacements include patellofemoral maltracking, component loosening, and infection.

Another common arthroplasty procedure is the hip replacement (Figure 5-2A and B), with over 450,000 hip replacements performed yearly in the United States making it the fourth most performed operation.⁶ The hip joint is composed of the articulation between the acetabulum of the pelvis and the femoral head. It is when the cartilage lining this articular surface is disrupted that patients
complain of discomfort. Patients with arthritis of the hip may complain of pain in the groin, outer thigh, knee, and/or buttock. They often complain of pain with walking distances and may even have a limp. Although osteoarthritis is the most common cause for hip arthroplasty, other causes include rheumatoid arthritis, avascular necrosis, developmental dysplasia of the hip (DDH), post-traumatic arthritis, and fracture. There are two types of hip arthroplasty: in total hip arthroplasty, both the femoral head and acetabular lining are replaced (Figure 5-2A); in hemiarthroplasty, only the femoral head is replaced keeping the native acetabulum (Figure 5-2B). Although hip replacements are very well-tolerated procedures, possible complications include hip dislocation, periprosthetic joint infection, thromboembolic disease, and periprosthetic fracture (Figure 5-3). Although newer surgical approaches may decrease the number of patients sustaining hip dislocation, the incidence of such
complications is cited at 1% to 3%, with 70% of those dislocations occurring within the first month.⁷ Two of the more significant causes of dislocation are hardware loosening and infection.

Orthopaedic surgeons as well as hand specialists see patients with conditions and trauma related to the fingers, hand, and wrist. The anatomy of this area of the human body is complex, with 27 bones in the hand and 8 carpal bones in the wrist plus connective tendons and supportive nerves, all of which allow people to normally engage
in a wide range of precise motion. It also creates the opportunity for many different injuries.

The most common fractures in the hand and wrist are distal radius fractures (Figure 5-4). Such fractures can result from high-energy injuries in the young or lower-energy injuries (such as falls) in the elderly. These fractures are often associated with distal ulna or radioulnar joint injuries. Half of these fractures are intra-articular and may require surgical fixation. Although fractures of the distal radius are the most common, there is a substantial incidence of fractures of other parts of the hand and wrist (as shown in Table 5-3). For patients over the age of 65, carpal bones are other common types of hand/wrist fractures. The most common carpal bone injuries are scaphoid fractures, typically caused by a patient catching
his/her fall with an outstretched hand. Although most of these fractures can be treated nonoperatively, some do require surgery because the tenuous blood supply of the scaphoid bone creates an increased risk of nonunion and avascular necrosis, potentially leading to later arthritis (Figure 5-5).

Nerve injuries of the hand and wrist are also common with compressive neuropathies responsible for most of these injuries. In these conditions, direct mechanical pressure on the nerve results in such symptoms as pain, numbness, and sometimes muscle weakness. These compressive neuropathies can occur in the three major nerves of the upper extremity: median nerve, ulnar nerve, and radial nerve (Figure 5-6). The resulting symptoms depend on the damaged nerve and the location of this injury. Median nerve compression is the most common compressive neuropathy seen in the hand and wrist. Median nerve compression can result in carpal tunnel syndrome (CTS), anterior interosseous syndrome, and pronator syndrome. CTS is the most common of these, with an incidence of approximately 375 per 100,000 person-years.⁸ This is caused by compression of the median nerve, most often as the nerve travels under the transverse carpal ligament in the carpal tunnel of the wrist. These patients will particularly complain of neuropathic symptoms on the palmar side of the three most radial fingers and the radial side of the fourth digit, with symptoms worse at night. Although risk factors for CTS include obesity,
pregnancy, and diabetes, the most common form of CTS in adults is idiopathic. Anterior interosseous syndrome presents as grip and pinch weakness, with patients classically unable to make an “OK” sign due to an inability to flex their thumb and index finger. This results from compression of the anterior interosseous nerve (AIN), the last motor branch of the median nerve, most often under the deep head of the pronator teres. Unlike the other common median nerve neuropathies, patients with this syndrome have no sensory deficits because the AIN has no cutaneous sensory branches. The third median nerve syndrome is pronator syndrome, resulting from compression of the median nerve at the elbow. This results in pain over the volar forearm and neuropathic symptoms on the palmar

side of the three radial fingers and the radial side of the fourth digit. Unlike CTS, these neuropathic sensory changes extend into the palm. Ulnar nerve neuropathies include cubital tunnel syndrome and ulnar tunnel syndrome. Cubital tunnel syndrome is typically caused by compression of the ulnar nerve between the two heads of the flexor carpi ulnaris muscle. Symptoms include paresthesias of the fifth finger, ulnar side of the fourth finger, and ulnar side of the dorsum of the hand exacerbated with elbow flexion in addition to weakness of the intrinsic hand muscles resulting in decreased grip and pinch strength. The second ulnar nerve neuropathy, ulnar tunnel syndrome, results from compression of the ulnar nerve in Guyon’s canal located at the base of the ulnar side of the palm. Symptoms include paresthesias of the palmar aspect of the fifth finger and the ulnar side of the fourth finger; however, patients should not have any symptoms in the dorsum of the hand. Similar to cubital tunnel syndrome, patients may also experience weakness of the intrinsic hand muscles resulting in decreased grip and pinch strength. Radial nerve neuropathies include posterior interosseous nerve (PIN) compression syndrome, radial tunnel syndrome, and Wartenberg’s syndrome. These are much rarer than median nerve and ulnar nerve compressive neuropathies. PIN compression syndrome is due to compression of the PIN that innervates the extensor muscles. Compression most commonly occurs at the proximal edge of the supinator, also known as the Arcade of Frohse. Patients complain of pain in the forearm and wrist and weakness with wrist extension. Radial tunnel syndrome also results from compression of the posterior interosseous nerve; however, patients only complain of aching pain in the dorsoradial forearm. There will be no sensory or motor deficits. Wartenberg’s syndrome results from compression of the superficial sensory radial nerve between the brachioradialis and extensor carpi radialis longus tendons. Patients complain of paresthesias and pain over the dorsoradial hand. Physical examination of these patients will reveal no motor weakness.