Essentials of Orthopedic Surgery, third edition / 14-Answers to Questions

546 S.C. Scherping, Jr.

Radiographic and Laboratory Evaluation

Plain radiographs of the knee demonstrated no bony lesions, only an effusion. A bone scan was remarkable for intense uptake in the medial condyle of the femur on all images including the delayed-phase bony images. The reminder of the skeleton was normal on all phases of the bone scan. A magnetic resonance imaging (MRI) scan of the knee showed no evidence of any intraarticular pathology. It did, however, demonstrate an area of hypointensity on T1-weighted images and hyperintensity on T2-weighted images in the medial condyle of the femur. No area of frank cortical disruption or soft tissue involvement was detected. (See Figs. 1 through 6.)

Laboratory studies were notable for a normal white blood cell count but a markedly elevated erythrocyte sedimentation rate (ESR) of 83.

Treatment

Upon presentation to the office, an arthrocentesis was performed to rule out the possibility of septic arthritis. The joint fluid was consistent with an aseptic effusion, and follow-up cultures were unremarkable. After evaluation of the bone scan and MRI of the knee, a presumptive diagnosis of

FIGURE 1. Anteroposterior (AP) radiograph of the knee.

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FIGURE 2. Lateral radiograph of the knee. An effusion is evident.

FIGURE 3. Delayed-phase bone scan demonstrating intense uptake in the medial condyle of the femur.

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FIGURE 4. T1-weighted coronal of the left knee. Hypointense signal is evident in the medial condyle.

FIGURES 5. T2-weighted images demonstrate hyperintensity in the medial condyle consistent with edema.

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FIGURES 6. Axial T1-weighted MRI demonstrating signal change in the medial femoral condyle.

osteomyelitis was made. Blood cultures were obtained and noted to be unremarkable. The patient was then taken to the operating room where, through a limited medical incision, a small cortical window was made into the medial femoral condyle and several specimens obtained for pathologic and microbiologic evaluation. Intraoperative findings included a small area of inflammatory change and patchy necrosis consistent with osteomyelitis. No areas of frank purulence were encountered. Intraoperative cultures grew Staphylococcus aureus. The patient was started on a 6-week course of intravenous antibiotics with resolution of all clinical symptoms and normalization of all laboratory data with presumptive cure of osteomyelitis.

Discussion

Osteomyelitis arises from one of two pathways: hematogenous spread or direct inoculation. A common source of direct inoculation is an open fracture, particularly one with gross contamination or inappropriate initial management. In this case, the development of the osteomyelitis was

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undoubtedly from transient bacteria related to the superficial foot infection. If found early, before the development of an abscess or a bony sequestrum, osteomyelitis is generally be successfully treated with appropriate antibiotic therapy alone, which is why the timely diagnosis of a bone infection plays a critical role in minimizing the morbidity of treatment. In some instances, however, surgical treatment, or at a minimum a biopsy, will be necessary to precisely define the bacteriologic origin and thereby allow a specific course of antibiotic therapy. In this case, as the presumed osteomyelitis was of uncertain origin, the biopsy and limited debridement were performed to refine the selection and course of antibiotic therapy. In most instances of a confirmed osteomyelitis, a minimum of 6 to 8 weeks of treatment is necessary.

Hip Osteoarthritis

BRIAN G. EVANS

History

This patient is a 65-year-old woman who has had a long-standing history of pain in the right groin. The pain has been gradually getting more severe, resulting in the patient limping when she walks for more than 10 to 15 minutes. The pain began approximately 6 to 7 years ago. Initially, she thought the pain was caused by a groin pull. She tried treating it on her own with nonsteroidal antiinflammatory medications such as ibuprofen, which provided good symptomatic relief. Over the past 1 to 2 years, however, the pain has become much more pronounced. She has pain at night when she turns over and significant pain and stiffness in the morning when she first gets up out of bed. Also, with prolonged sitting, such as during a car ride or if she goes out to dinner, after approximately 30 to 40 minutes, she has significant pain in the hip that requires her to get up and move about to alleviate the pain. If she has been sitting for more than 10 to 15 minutes, when she arises from the sitting position she also has a significant degree of stiffness when she first starts walking. Initially, this pain was well treated with ibuprofen; however, currently she is having a significant degree of pain and discomfort, even when taking 600 to 800 mg ibuprofen three times a day. She has also had increasing difficulty putting on her socks and tying shoes. She has been unable to clip her toenails for several years, particularly on the right side. She has a history of some mild hypertension, but otherwise she is in good health and feels quite limited by her right-sided groin pain. She denies any numbness, tingling, or weakness in the leg. She has not had any buckling. The pain does not worsen with coughing or sneezing, and she has no pain in the buttock or posterior thigh.

Physical Examination

The patient walks with a significant coxalgic gait consisting of a reduced stance phase and a Trendelenburg lurch. When she stands, she stands with the right knee slightly flexed with her weight on the left side. She does have

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stiffness and a limp when she moves from a chair in the examination room to sit on the examination table.

When examining the lower extremities, she has 5/5 motor strength in the extensor hallucis longus, tibialis anterior, gastrocnemius-soleus, and quadriceps muscles. She has no decrease in sensation to light touch over both lower extremities. With the patient supine, both legs have equal limb lengths. On assessing range of motion, on the right side she has flexion to approximately 85 degrees, extension to the table, internal rotation to 0 degrees, and external rotation of approximately 45 degrees, and adduction of 5 degrees and abduction of approximately 30 degrees. All range of motion is limited to pain. On assessing for flexion contracture with the Thomas test, she has a 15 degree flexion contracture on the right hip and none on the left. On the left side she has flexion to 105 degrees, full extension, internal rotation of 15, external rotation of 70, and adduction of 20 and abduction of 45 degrees. She has no pain with range of motion of her knees or ankles. She has no exacerbation of her pain with extension or flexion or lateral bending of the lumbar spine.

Radiographs

Figure 1 is an anteroposterior (AP) radiograph of the pelvis showing both hips that demonstrates a normal left hip with a well-maintained articular space and no osteophyte formation. The right hip, however, has extensive osteoarthritic changes. There is no articular space, extensive osteophyte

FIGURE 1. Anteroposterior (AP) radiograph of the pelvis showing both hips.

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FIGURE 2. Lateral radiograph of the right hip demonstrates extensive osteoarthritis of the hip, with no articular space, subchondral sclerosis, and osteophyte formation.

formation is noted, and sclerosis or increased density in the bone is noted both in the femoral head as well as on the acetabular side. Figure 2, a lateral radiograph of the right hip, again demonstrates extensive osteoarthritis of the hip, with no articular space, subchondral sclerosis, and osteophyte formation.

Diagnosis

A patient with substantial osteoarthritis of the right hip, which is significant clinically in terms of pain and reduction in function and radiographically in terms of marked changes on the plain radiographs.

Treatment

The treatment alternatives for this patient are either to continue with current medications, with stronger antiinflammatories, and with reduction in activities or use of a cane. The other treatment alternative would be a total hip arthroplasty. The benefit of total hip arthroplasty would be relief

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of pain and restoration of ambulatory function and ability. The risks of the surgery, as indicated in Chapter 11, are the risks of bleeding, thromboembolic disease, dislocation, and loosening of the components. These possibilities were reviewed with the patient in detail, and the patient elected to proceed with total hip arthroplasty.

Figure 3 shows the patient after having had a right hybrid total hip replacement. This replacement consists of a cemented femoral stem with a noncemented acetabular component. The components appear to be well

fixed and well aligned. There is good interdigitation of the bone cement into the femoral cortex, and the overall limb alignment and anatomy have been restored.

The patient did well subsequent to the surgery. She returned to the office at 2 weeks postoperatively, able to ambulate with only the use of a cane with no pain, taking no pain medications. She returned again 6 weeks after the surgery and was ambulating freely without the use of a cane, crutch, or walker. She was able to ambulate for 40 to 60 minutes with no difficulty whatsoever and had no limp in her gait and no pain with routine activities. She was also able to put a sock on her right foot, clip her right toenails, and tie a shoe on her right foot without difficulty.

This patient has done well after a total hip arthroplasty. She should enjoy continued success with the arthroplasty for approximately 15 to 20 years.

Discussion

The treatment of osteoarthritis of the hip is based upon exploring nonoperative management as long as possible. Nonoperative management includes NSAIDs, physical therapy, the use of a cane, and, if appropriate, weight loss. In the end, however, the arthritis becomes increasingly symptomatic. As the pain and limitation of mobility become more severe, the next step in treatment is total hip replacement, done after nonoperative management fails. The timing for total hip replacement is elective; it is based solely upon the patient’s pain and the impact of the pain upon their life and activities.

Total hip replacement is an excellent surgical option. It has an extremely high success rate, and after recovery the patient moves and ambulates completely normally, which allows a near-complete return to normal activities. However, the patients should not participate in running or cutting activity such as jogging and racquet sports after total hip replacement as these activities may result in early loosening and wear of the implanted devices. They are encouraged to keep aerobically fit with nonimpact aerobic activities such as cycling and swimming.

Total hip replacement commonly results in excellent functional return. Some patients, years after surgery, may have to stop and think which hip they had replaced. That is the definition of a good result.

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FIGURE 3. Right hybrid total hip replacement consists of a cemented femoral stem with a noncemented acetabular component.