++
Rheumatic disorders are very common and responsible for considerable pain or discomfort, disability and loss of independence in the elderly.
++
Osteoarthritis is the most common cause and excellent results are now being obtained using total knee replacement in those severely affected.
++
The elderly are particularly prone to crystal-associated joint diseases, including monosodium urate (gout), CPPD (pseudogout) and hydroxyapatite (acute calcific periarthritis).
+++
Chondrocalcinosis of knee (pseudogout)
++
The main target of CPPD is the knee, where it causes chondrocalcinosis. Unlike gout, chondrocalcinosis of the knee is typically a disorder of the elderly with about 50% of the population having evidence of involvement of the knee by the ninth decade.14 Most cases remain asymptomatic but patients (usually aged 60 or older) can present with an acutely hot, red, swollen joint resembling septic arthritis.
++
Investigations include aspiration of the knee to search for CPPD crystals, and X-ray. If positive, consider an associated metabolic disorder such as haemochromatosis, hyperparathyroidism or diabetes mellitus. The treatment is similar to acute gout although colchicine is less effective. Acute episodes respond well to NSAIDs or intra-articular corticosteroid injection.
++
Spontaneous osteonecrosis of the knee (SPONK) is more common after the age of 60, especially in females; it can occur in either the femoral (more commonly) or tibial condyles. The aetiology is unknown. The sudden onset of pain in the knee, with a normal joint X-ray, is diagnostic of osteonecrosis. However, the X-ray (especially later) will demonstrate an area of osteonecrosis. The pain is usually persistent, with swelling and stiffness, and worse at night. It can take three months for the necrotic area to show radiologically although a bone scan or MRI may be positive at an early stage (see FIG. 67.14). The condition may resolve in time with reduction of weight-bearing. Surgery in the form of subchondral drilling may be required for persistent pain in the early stages.
++
+++
Osteochondritis dissecans: adult form
++
The adult form occurs more often in males and may be the result of cysts of osteoarthritis fracturing into the joint. Up to 30% are bilateral. Symptoms depend on whether the osteochondral fragment becomes separated. A loose fragment may produce locking or collapse of the knee.
++
The large knee joint is a ‘haven’ for intra-articular loose bodies, which may be formed from bone, cartilage or osteochondral fragments following injury (‘chip’ fragment), osteochondritis dissecans, osteoarthritis, synovial chondromatosis or other conditions. They may be asymptomatic but usually cause clicking or locking with swelling. Diagnosis is by X-ray and surgical removal is necessary for recurrent problems.
++
This common complaint is usually a result of a pedunculated fibrous lump in the prepatellar bursa, often secondary to trauma, such as falls onto the knee.
++
Medial and lateral meniscal tears are usually caused by abduction and adduction forces causing the meniscus to be compressed between the tibial and femoral condyles and then subjected to a twisting force or a rotatory movement on a semi-flexed weight-bearing knee.
++
The medial meniscus is three times more likely to be torn than the lateral. These injuries are common in contact sports and are often associated with ligamentous injuries. Suspect these injuries when there is a history of injury with a twisting movement with the foot firmly fixed on the ground.
++
However, pain in the knee can present in the patient aged 30–50 years (and beyond 50) as the menisci degenerate, with resultant cleavage tears from the posterior horn of the medial meniscus and ‘parrot-beak’ tears of the mid-section of the lateral meniscus. These problems cause pain because these particular deformities create tension on the joint capsule and stretch the nerve ends. Refer to the provocation tests—Thessaly, McMurray and Apley grind tests. X-rays are not specifically useful, but an MRI scan should confirm diagnosis.
++
++
Arthroscopic partial meniscectomy offers relief. The peripheral meniscus is vascular and can be repaired within 6–12 weeks of injury.16
++
++
Arthroscopic meniscectomy is appropriate treatment, but some do settle with a trial of physiotherapy.
++
TABLE 67.4 is a useful aid in the diagnosis of these injuries. There is a similarity in the clinical signs between the opposite menisci, but the localisation of pain in the medial or lateral joint lines helps to differentiate between the medial and lateral menisci.
++
Note: The diagnosis of a meniscal injury is made if three or more of the five examination findings (‘signs’ in TABLE 67.4) are present.
++
Tears of varying degrees may occur in the:
++
anterior cruciate ligament
posterior cruciate ligament
medial collateral ligament
lateral collateral ligament
+++
Anterior cruciate ligament rupture
++
This is a very serious and disabling injury that may result in chronic instability. Chronic instability can result in degenerative joint changes if not dealt with adequately. Early diagnosis is essential, but there is a high misdiagnosis rate. Sites of ACL rupture are shown in FIGURE 67.15.
++
++
Sudden change in direction with leg in momentum
Internal tibial rotation on a flexed knee (commonest) (e.g. during pivoting)
Marked valgus force (e.g. a rugby tackle)
May be associated with collateral ligament tears and meniscus injuries. The so-called ‘unhappy triad’ is a ruptured ACL, medial meniscus tear and medial collateral ligament tear.
++
Onset of severe pain after a sporting injury, such as landing from a jump, or a forced valgus rotational strain of the knee when another player falls across the abducted leg
Immediate effusion of blood, usually within 30 minutes
Common sports: contact sports—rugby, football and soccer, basketball, volleyball, skiing
Differential diagnosis is a subluxed or dislocated patella
Subsequent history of pain and ‘giving way’ of the knee
++
Gross effusion
Diffuse joint-line tenderness
Joint may be locked due to effusion, anterior cruciate tag or associated meniscal (usually medial) tear
Ligament tests:
– anterior drawer: negative or positive
– pivot shift test: positive (only if instability)
– Lachman test: lacking an end point
++
Note: It may be necessary to examine the knee under anaesthesia, with or without arthroscopy, to assess the extent of injury.
++
This test is emphasised because it is a sensitive and reliable test for the integrity of the ACL. It is an anterior draw test with the knee at 15–20° of flexion. At 90° of flexion, the draw may be negative but the anterior cruciate torn.
++
Method—Lachman test
The examiner should be positioned on the same side of the examination couch as the knee to be tested.
The knee is held at 15–20° of flexion by placing a hand under the distal thigh and lifting the knee into 15–20° of flexion.
The patient is asked to relax, allowing the knee to ‘fall back’ into the steadying hand and roll slightly into external rotation.
The anterior draw is performed with the second hand grasping the proximal tibia from the medial side (see FIG. 67.16) while the thigh is held steady by the other hand. The examiner’s knee can be used to steady the thigh.
The feel of the end point of the draw is carefully noted. Normally there is an obvious jar felt as the anterior cruciate tightens. In an anterior cruciate deficient knee there is excess movement and no firm end point. The amount of draw is compared with the opposite knee. Movement greater than 5 mm is usually considered abnormal.
++
Functional instability due to anterior cruciate deficiency is best elicited with the pivot shift test. This is more difficult to perform than the Lachman test.
++
This is an important test for anterolateral rotatory instability. It is positive when anterior cruciate injuries are sufficient to produce a functional instability.
++
Method—Pivot shift test
The tibia is held in internal rotation by grasping the ankle firmly, with the knee in full extension.
A valgus force is applied to the knee with the hand placed on the lateral aspect of the knee just below it (this maximises subluxation in the presence of an ACL tear).
The knee is then flexed from 0–90°, listening for a ‘clunk’ of reduction. The test is positive when there is a sudden change of rhythm during flexion that corresponds to relocation of the subluxed knee. This usually occurs between 30° and 45° of flexion.
From this flexed position, the knee is extended, seeking a click into subluxation. This is called a positive jerk test.
++
Management depends on the finding by the surgeon. Surgical repair is reserved for complete ligament tears. This usually involves reconstruction of the ligament using patellar or preferably hamstring tendons. Early reconstruction is appropriate in younger patients who participate in high levels of sporting activity for whom it can be predicted that functional instability will be a problem. In less active people, a conservative approach is appropriate. The ACL may be trimmed. Cruciate reconstruction can then be undertaken if the knee becomes clinically unstable. The presence of an ACL injury with a significant medial ligament injury will necessitate reconstructive surgery, but this is probably best delayed for some weeks as the subsequent incidence of knee stiffness is high.
+++
Posterior cruciate ligament rupture
++
Direct blow to the anterior tibia in flexed knee
Severe hyperextension injury
Ligament fatigue plus extra stress on knee
++
Posterior (popliteal) pain, radiating to calf
Usually no or minimal swelling
Minimal disability apart from limitation of running or jumping
Pain running downhill
Recurvatum
Posterior sag or draw
++
+++
Medial collateral ligament rupture
++
++
These depend on the degree of tear (1st, 2nd or 3rd degree):
++
pain on medial knee
aggravated by twisting or valgus stress
localised swelling over medial aspect
pseudo-locking—hamstring strain
± effusion
no end point on valgus stress testing (3rd degree) (see FIG. 67.9a)
++
Note: Check lateral meniscus if MCL tear. Pellegrini–Stieda syndrome—calcification in haematoma at upper (femoral) origin of MCL—may follow.
++
If an isolated event, this common injury responds to conservative treatment with early limited motion bracing to prevent opening of the medial joint line. Six weeks of limited motion brace at 20–70° followed by knee rehabilitation usually returns the athlete to full sporting activity within 12 weeks.
++
Note: The same principles of diagnosis and management apply to the less common rupture of the lateral collateral ligament, which is caused by a direct varus force to the medial side of the knee. However, lateral ligament injuries tend to involve the cruciate ligament and reconstruction of both ligaments is usually necessary.16
+++
Complex regional pain syndrome I
++
A localised complex regional pain syndrome I (also known as reflex sympathetic dystrophy) can follow a direct fall onto the knee. (See CHAPTER 12.)
++
++
The knee is very prone to overuse disorders. The pain develops gradually without swelling, is aggravated by activity and relieved with rest. It can usually be traced back to a change in the sportsperson’s training schedule, footwear or technique, or to related factors. It may also be related to biomechanical abnormalities ranging from hip disorders to feet disorders.
++
Overuse injuries include:
++
patellofemoral pain syndrome (‘jogger’s knee’, ‘runner’s knee’)
patellar tendonopathy (‘jumper’s knee’)
anserinus tendonopathy/bursitis
semimembranous tendonopathy/bursitis
biceps femoris tendonopathy
quadriceps tendonopathy/rupture
popliteus tendonopathy
iliotibial band friction syndrome (‘runner’s knee’)
the hamstrung knee
synovial plica syndrome
infrapatellar fat-pad inflammation
++
It is amazing how often palpation identifies localised areas of inflammation (tendonopathy or bursitis) around the knee, especially from overuse in athletes and in the obese elderly (see FIG. 67.17).
++
+++
Patellofemoral pain syndrome
++
This syndrome, also known as chondromalacia patellae or anterior knee pain syndrome and referred to as ‘jogger’s knee’, ‘runner’s knee’ or ‘cyclist’s knee’, is the most common overuse injury of the knee. There is usually no specific history of trauma. It may be related to biomechanical abnormalities and abnormal position and tracking of the patella (e.g. patella alta). It usually presents in females aged 13–15 years with faulty knee mechanisms or in people aged 50–70 years with osteoarthritis of the patellofemoral joint.18
++
Pain behind or adjacent to the patella or deep in the knee
Pain aggravated during activities that require flexion of the knee under loading:
The ‘movie theatre’ sign: using aisle seat to stretch knee
Crepitus around patella may be present
+++
Signs (chondromalacia patellae)
++
Patellofemoral crepitation during knee flexion and extension is often palpable, and pain may be reproduced by compression of the patella onto the femur as it is pushed from side to side with the knee straight or flexed (Perkins test).
+++
Method for special sign—patella grind test
++
++
Have the patient supine with the knee extended.
Grasp the superior pole of the patella and displace it inferiorly.
Maintain this position and apply patellofemoral compression.
Ask the patient to contract the quadriceps (it is a good idea to get the patient to practise quadriceps contraction before applying the test).
A positive sign is reproduction of the pain under the patella and hesitancy in contracting the muscle.
++
Give reassurance and supportive therapy.
Reduce any aggravating activity.
Refer to a physiotherapist.
Correct any underlying biomechanical abnormalities such as pes planus (flat feet) by use of orthotics and correct footwear.
Employ quadriceps (especially) and hamstring exercises.
Consider course (trial) of NSAIDs.
+++
Patellar tendonopathy (‘jumper’s knee’)
++
‘Jumper’s knee’, or patellar tendonopathy (see FIG. 67.2, earlier in this chapter), is a common disorder of athletes involved in repetitive jumping sports, such as high jumping, basketball, netball, volleyball and soccer. It probably starts as an inflammatory response around a small tear.
++
Gradual onset of anterior pain
Pain localised to below knee (in patellar tendon)
Pain eased by rest, returns with activity
Pain with jumping
++
The diagnosis is often missed because of the difficulty of localising signs. The condition is best diagnosed by eliciting localised tenderness at the inferior pole of the patella with the patella tilted. There may be localised swelling.
++
Lay the patient supine in a relaxed manner with the head on a pillow, arms by the side and quadriceps relaxed (a must).
The knee should be fully extended.
Tilt the patella by exerting pressure over its superior pole. This lifts the inferior pole.
Now palpate the surface under the inferior pole. This allows palpation of the deeper fibres of the patellar tendon (see FIG. 67.19).
Compare with the normal side.
Very sharp pain is usually produced in the patient with patellar tendonopathy.
++
Early conservative treatment, including rest from the offending stresses, is effective. Referral to a physiotherapist for exercise-based rehabilitation is appropriate. This includes adequate warm-up and warm-down. Training modification includes calf, hamstring and quadriceps muscle stretching. Modified footwear and a patellar tendon strap may be helpful in some cases. The use of NSAIDs and corticosteroid injections is disappointing. Chronic cases may require surgery.
+++
Anserinus tendonopathy/bursitis
++
Localised tenderness is found over the medial tibial condyle where the tendons of the sartorius, gracilis and semitendinosus insert into the bone. It is distal to the joint line. It is a common cause of knee pain in the middle-aged or elderly, especially the overweight woman. Pain is aggravated by resisted knee flexion.
+++
Semimembranous tendonopathy/bursitis
++
This inflamed area is sited either at the tendon insertion or in the bursa between the tendon and the medial head of the gastrocnemius. It is an uncommon problem. The bursa occurs on the medial side of the popliteal fossa between the medial head of the gastrocnemius and the semimembranous tendon. It often communicates with the knee joint and, if so, treat knee joint pathology. If not, one can give an injection of depot triamcinolone or betamethasone.
+++
Biceps femoris tendonopathy/bursitis
++
The tendon and/or the bursa that lies between the tendon insertion and the fibular collateral ligament at the head of the fibula may become inflamed due to overuse. It is usually encountered in sprinters.
+++
Popliteus tendonopathy
++
Tenosynovitis of the popliteus tendon may cause localised pain in the posterior or the posterolateral aspect of the knee. Tenderness to palpation is elicited with the knee flexed to 90°.
+++
Iliotibial band syndrome
++
Inflammation develops over the lateral aspect of the knee where the iliotibial band passes over the lateral femoral condyle. An inflamed bursa can occur deep to the band. The problem, which is caused by friction of the iliotibial band on the bone, is common in long-distance runners, especially when running up and down hills, and in cyclists. It presents with well-localised lateral knee pain of gradual onset. Palpation reveals tenderness over the lateral condyle 1–2 cm above the joint line.
+++
Treatment of tendonopathy and bursitis (small area)
++
Generally (apart from patellar tendonopathy), the treatment is an injection of local anaesthetic and long-acting corticosteroids into and deep to the localised area of tenderness. In addition, it is important to restrict the offending activity and refer for physiotherapy for stretching exercises. Attention to biomechanical factors and footwear is important.
++
If conservative methods fail for iliotibial tract tendonopathy, surgical excision of the affected fibres may cure the problem.
++
Repetitive low-grade direct trauma, such as frequent kneeling, can cause inflammation with swelling of the bursa, which lies between the anterior surface of the patella and the skin. ‘Housemaid’s knee’, or ‘carpet layer’s knee’, can be difficult to treat if rest from the trauma does not allow it to subside. If persistent, drain the fluid with a 23 gauge needle and then introduce 0.5–1 mL of long-acting corticosteroid. The presence of a bursa ‘mouse’ and persistent bursitis usually mean that surgical intervention is required.
++
Acute bursitis may also be caused by acute infection, or one of the inflammatory arthropathies (e.g. gout, seronegative spondyloarthropathies).
+++
Infrapatellar bursitis
++
‘Clergyman’s knee’ is produced by the same mechanisms as prepatellar bursitis and can be involved with inflammatory disorders or infection. Treatment is also the same.
++
Cross describes this condition in young active sportspeople (second decade)9 as one that causes bilateral knee pain and possibly a limp. It is caused by a failure to warm up properly and stretch the hamstring muscles, which become tender and tight during the growth spurt. A 6-week program of straight leg raising and hamstring stretching will alleviate the pain completely.
+++
Synovial plica syndrome
++
This syndrome results from a synovial fold (an embryological remnant) being caught between the patella and the femur during walking or running. It causes an acute ‘catching’ knee pain of the medial patellofemoral joint (see FIG. 67.2, earlier in this chapter) and sometimes a small effusion. It generally settles without treatment.
+++
Infrapatellar fat-pad inflammation
++
Hoffa fat pad syndrome follows acute compression of the fat-pad, which extends across the lower patella deep to the patellar tendon and into the knee joint (see FIG. 67.2, earlier in this chapter), during a jump or other similar trauma, producing local pain and tenderness similar to the sensation of kneeling on a drawing pin.18
++
The pain usually settles without therapy over a period of days or weeks. There is localised tenderness and it can be confused with patellar tendonopathy.
++
Osteoarthritis is a very common problem of the knee joint. Symptoms usually appear in middle life or later. It is more common in women, obese people, and in those with knee deformities (e.g. genu varum) or previous trauma, especially meniscal tears. The degenerative changes may involve either the lateral or the medial tibiofemoral compartment, the patellofemoral joint or any combination of these sites.
++
Slowly increasing joint pain and stiffness
Aggravated by activities such as twisting, bending, prolonged walking, standing or squatting
Descending stairs is usually more painful than ascending stairs (suggestive of patellofemoral osteoarthritis)
Pain may occur after rest, especially prolonged flexion
Minimal effusion and variable crepitus
Restricted flexion but usually full extension
Often quadriceps wasting and tender over medial joint line
Diagnosis confirmed by X-ray (weight-bearing view)
++
Relative rest
Weight loss
Analgesics and/or judicious use of NSAIDs
Glucosamine: a Cochrane review showed that it is both safe and modestly effective (see CHAPTER 35)
Walking aids and other supports
Physiotherapy (e.g. hydrotherapy, quadriceps exercises, mobilisation and stretching techniques)
Viscosupplementation: intra-articular injection of hylans
Intra-articular injections of corticosteroids are generally not recommended, but a single injection for severe pain can be very effective
Surgery is indicated for severe pain and stiffness and includes arthroscopic debridement and wash out, osteotomy, arthrodesis and total joint replacement (see FIG. 67.20) or hemiarthroplasty, especially for the medial compartment with focal arthritis and varus deformity
++
++
The knee is frequently affected by rheumatoid arthritis (RA), although it rarely presents as monoarticular knee pain. RA shows the typical features of inflammation—pain and stiffness that is worse after resting. Morning stiffness is a feature.
++
Note: The spondyloarthropathies have a similar clinical pattern to RA.
++
Synovectomy is a useful option with persistent boggy thickening of synovial membrane but without destruction of the articular cartilage.2
++
A popliteal cyst (Baker cyst) is a herniation of a chronic knee effusion between the heads of the gastrocnemius muscle and is usually associated with osteoarthritis (most common), rheumatoid arthritis or internal derangement of the knee. It presents as a mass behind the knee and may or may not be tender or painful.
++
It tends to fluctuate in size.
++
A Baker cyst indicates intra-articular pathology and indicates a full assessment of the knee joint.
++
Rupture may result in pain and swelling in the calf, mimicking DVT.
++
Treat underlying knee inflammation (synovitis).
++
Surgical removal of the cyst is advisable for persistent problems.
++
This tends to be more common in the knee than in other joints. Septic (pyogenic) arthritis should be suspected when the patient complains of intense joint pain, malaise and fever. In the presence of acute pyogenic infection, the joint is held rigidly. The differential diagnosis includes gout and pseudogout (chondrocalcinosis).