Medical History and Physical Examination

Question

Reason

What was the original indication for surgery?

Postoperative pain may be due to another underlying pathology, e.g., RA, Paget’s disease

Was navigation used?

Pin insertion sites may give rise to stress fracture and pain [3, 4]

Was the patella resurfaced?

Identifies potentially treatable cause of pain

Was the knee replacement cemented or uncemented?

Higher incidence of pain in uncemented

Were the implants stemmed or unstemmed?

Higher incidence of pain with stemmed implant

The primary aim of the first patient consultation is to define what the most prominent problem of the patient is. The main clinical symptoms are pain, swelling, stiffness, and instability.

Before a detailed history concerning these clinical symptoms, the following issues have to be clarified (Tables 25.1 and 25.2):

Table 25.2

Summary of diagnostic steps (history and physical examination)

History	Infection, aspiration, antibiotics, surgery and reports, trauma, allergies, symptoms, previous conservative therapy, social background
Type of pain	Rest or night, walking on even ground, stair climbing, rising from a chair, location, other promoting factors, localized or diffuse
Psychological	Signs of depression and anxiety, psychological and psychopharmacological therapy
Physical examination	Gait, chair and stair tests, skin, circulation, muscular atrophy, ROM (active and passive), patella tracking, stability at 0–30–60–90°, evaluation of other joints, laxity, alignment at 0–30–90°

All available information regarding the primary TKR and/or other previous surgery should be obtained. In particular, it is important to gather all information on the type of TKR implanted (e.g., primary versus revision TKR, size of TKR, cruciate retaining versus cruciate substituting, nonconstrained versus semi-constrained versus hinged TKR, CR versus PS, cemented versus uncemented, fixed versus mobile bearing, company’s name and TKR type). The operative records should be reviewed in detail. It might be of interest whether measured resection technique or ligament balancing technique or femur- or tibia-first techniques have been used. Information about any early complications (e.g., persistent wound drainage, hematoma, infection, stiff knee) and the course of rehabilitation after surgery will be of help.

A number of systemic diseases may influence the functional outcome following TKR and/or increase the risk of certain vascular or infectious complications. Comorbidities including diabetes mellitus, obesity, neurologic conditions such as multiple sclerosis or Parkinson’s disease, and rheumatologic disorders should be identified.

Pathologies associated with an adjacent joint (hip, ankle) or the spine can cause pain and/or functional limitation that the patient may relate to the knee joint. Osteoarthritis limiting the motion of the ipsilateral hip can have a particularly negative influence on function following TKR that may be greatly improved following an intervention on the hip. Spinal stenosis or high lumbar disc pathology may present with hip and anterior knee pain. Knee pain is also commonly caused by ipsilateral hip arthritis or vascular disease. Severe plano-valgus foot deformity may lead to pain and valgus instability of the knee secondary to medial collateral ligament attenuation.

The presence of a contralateral TKR should be noted. An unsatisfactory result in the opposite leg resulting from malalignment or a flexion contracture may affect gait pattern and limit the outcome of the index knee.

The expectations of the patient and his or her motivation for undergoing TKR greatly affect the patient’s perception of the outcome after TKR [1]. The patient’s expectation may be very different from that of the surgeon. Scott Dye [2] highlighted several years ago the importance of matching patient expectations with the possible result after knee surgery. A recent study showed that while 85 % of patients expect a completely painless knee following TKR, only 43 % actually achieve it [3]. Among the activities that patients expect to be able to perform after TKR, the most common are gardening and kneeling. Return to sporting activities is only reported by about 10 % of patients over 75 years of age. Sporting activities typically include golf, cross-country skiing, or other aerobic activities such as biking or brisk walking. Patients should be aware of the limitations of TKR and develop reasonable expectations of outcome after TKR.

Certain patient factors may predispose to a higher risk of having unexplained pain after TKR. These factors include female sex, young age, a low degree of osteoarthritis preoperatively, and a history of depression or other psychological conditions. Patients need to be specifically questioned and screened.

The patient’s social situation can influence functional outcomes in a similar way. One must ascertain whether the patient is still physically active and identify the demands of his or her job and daily activities. One must not ignore factors related to work injuries and potential legal implications.

A detailed medication history should gather information on all medications used by the patient.

25.1 Key Symptom “Pain”

A thorough history is required to identify the main problem, which may be pain, stiffness, instability, or swelling. Pain is the most frequent and troublesome symptom for the patient [2]. Those patients with accompanying symptoms such as stiffness and instability are more likely to have an intrinsic cause.

It is essential to establish the characteristics of the pain including the onset, day- or nighttime, duration, nature, severity, location, radiation, aggravating or relieving factors, and association with rest or activity (Table 25.3). Pain that is unchanged following surgery is likely to have an extrinsic cause, including hip pathology, radiculopathy, or peripheral vascular disease. It is important to clarify whether the pain began early or late postoperatively. Early onset of pain is commonly caused by acute infection, instability secondary to poor soft tissue balancing, component malalignment, and soft tissue impingement. Late-onset pain is more commonly caused by component loosening, polyethylene wear, hematogenous infection, ligamentous instability, or stress fracture.

Table 25.3

Suggested etiology according the type of pain

Type of pain	Suggested etiology
Night and rest pain	Infection
Night and rest pain	Joint effusion or referred neurogenic
Pain on descending stairs and chair raising	Flexion gap instability
Pain on descending stairs and chair raising	Femur malrotation
Anterior knee pain	Patella maltracking
Anterior knee pain	Overuse tendinitis or neuroma
Posterior knee pain	Posterior soft tissue tightness
Posterior knee pain	Popliteus tendinitis
Pain on full extension	Anterior soft tissue impingement
Pain on full extension	Posterior tightness
Pain on full flexion	Post impingement (offset/osteophytes)
Pain on full flexion	Patella impingement or tightness
Starting pain	Loose components
Starting pain	Tibia and/or femur forceps pain
Weight-bearing pain	Unspecific
Weight-bearing pain	Mainly mechanical cause

Impingement typically causes a sharp, catching pain, while pain at rest is less likely to be mechanical. A history of rest pain or pain at night should raise suspicion of infection or referred neurological pain. The anatomical location of the pain correlates well with the site of the underlying problem. Pain aggravated by activity is likely to be caused by component loosening, instability, impingement, or tendonitis. Pain or hypersensitivity secondary to light touch suggests chronic regional pain syndrome (CRPS) or a cutaneous neuroma. Systemic features such as fever, chills, and malaise implicate infection, and the history must include an assessment of risk factors including diabetes mellitus, rheumatoid arthritis, psoriasis, and immune compromise. Additional sources of host infection including cuts and grazes, chest, urinary tract, or dental infection should be sought.

The original operation note needs to be examined carefully to determine which type of knee replacement was used. The key questions that need to be asked are summarized below.

The type, intensity, and character of pain should be meticulously evaluated and noted (Table 25.3). The following points have to be checked:

Chronicity

The onset of pain can provide important insight into its etiology. Preexisting pain unchanged by TKR suggests referred pain from another source (hip, spine, neurological). Pain following TKR without a pain-free interval is suggestive of a technical failure such as implant malposition, pathological laxity, or soft tissue impingement versus a postoperative infection. Pain that occurs after a symptom-free interval may be related to hematogenous infection, periprosthetic fracture, osteonecrosis of the patella, and loosening or mechanical failure of the implant. The circumstances surrounding the onset of symptoms can also point to the etiology of the pain. An injury or fall may have resulted in a mechanical complication, while a wound or infection (urinary, dental, or diabetic ulcer to name a few) suggests an infectious etiology.

Location and radiation

Pain that is localized to a specific area in the knee suggests a mechanical etiology, such as soft tissue impingement or implant oversizing. When the pain is more diffusely described, it is sometimes difficult to determine whether the pain is coming from the knee itself or the pain is referred from another location. Anterior knee pain suggests a patellofemoral etiology or patellar tendonitis, while a more posteriorly located pain can be attributed to a popliteal cyst, the presence of osteophytes, or remaining cement particles in the posterior capsule. A sensation of tightness in the knee may be related to an oversized prosthesis or liner, while dysesthesia and pain around the skin incision are rather suggestive of a neuroma.

Pain-provoking factors

Pain after activity is suggestive of a mechanical problem, possibly related to loosening, implant wear, or impingement. Pain when descending stairs or rising from a seated position is common in those with pain of patellofemoral origin as well as those with tibiofemoral joint laxity in flexion. Pain and mechanical symptoms at a specific point when moving from extension to flexion are suggestive of a patellar clunk syndrome caused by anterior scar formation that has been related to specific implant designs. Continuous pain and night pain suggest an infectious, allergic, or neurologic etiology. In this context, factors relieving the pain such as cooling or rest should also be noted.

Intensity

The intensity of the pain is best evaluated through the use of validated pain scales such as the commonly used visual analogue scale. The McGill Pain Questionnaire (MPQ) is a more sophisticated and complex self-administered questionnaire, described by Melzack in 1971 [4]. In the MPQ, specific adjectives used by patients to describe their pain were brought together, categorized, and scaled on a common intensity dimension. It provides a standardized measure of the affective and sensory dimensions of pain. A short form (SF-MPQ) was described and validated by Melzack in 1987 [5]. It consists of 15 adjectives describing sensory, affective, and evaluative aspects of the pain experience. The following are three measures included in the SF-MPQ: (1) the pain rating index (PRI), which rates 15 adjectives that best describe the current pain; (2) a visual analogue scale; and (3) the present pain intensity, which rates the overall intensity of the total pain experienced on a numerical rating scale, from 0 (no pain) to 5 (excruciating pain) [6]. Finally, one should review the patient’s medications including analgesics, anti-inflammatories, antidepressants, and anxiolytics.

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