This article discusses complications of total knee arthroplasty presented to GPs. Such complications include problems with wound healing, infection, bleeding, deep venous thrombosis, swelling, stiffness and persistent pain.
The rate of complications after total knee replacement is reported in most publications to range from 1.65 to 11.3%.1-2
Wound healing problems
Wound healing problems occur because of the thin soft tissue covering the knee, especially over the anterior aspect.
Healing problems can be associated with haematoma, especially in the elderly, patients on steroids, and rheumatoid arthritis and psoriasis patients.
Wound healing problems require urgent diagnosis and management to avoid more serious complications such as skin loss, infection and possible loss of the prosthesis. An unhealthy looking wound should be referred back to the surgeon as soon as possible.
Infection is a serious complication of total knee arthroplasty. The incidence of infection has been reported to be less than 1-2% with primary arthroplasty, 3-5% of revision knee arthroplasty 3 and as high as 16% with hinged implants. Patients with rheumatoid arthritis, diabetes mellitus, poor nutrition, old age, and obesity are at higher risk of both superficial and deep infection.
Surgical wound infections are often pain free with redness around the wound, discharging fluid, but with no joint effusion, joint stiffness, or restriction of movement.
Early deep infections are often due to relatively virulent pathogens such as Staph aureus and present with an acute onset of symptoms, including joint pain, joint effusion, induration, erythema, wound oozing and fever.
Early orthopaedic referral is paramount for the timely management of possible prosthetic joint infections, rather than immediately starting antibiotics.
Prompt aspiration and tissue culture is essential to start appropriate antibiotics. The treatment for deep infection in a joint includes intravenous antibiotic therapy, debridement, polyethylene liner exchange and revision surgery.
Deep vein thrombosis
DVT is one of the most feared complications of total knee replacement surgery and potentially can be fatal if the thrombosis embolises to the lungs.4 A DVT may be silent, presenting as a pulmonary embolism with shortness of breath, chest pain, and cyanosis, without limb symptoms. Alternatively, it may present with a painful calf or thigh usually 5-7 days postoperatively or earlier. A low threshold for lower limb ultrasound, chest X-rays and spiral CT chest may help to establish early diagnosis. Physical examination may reveal a unilateral swollen calf or thigh, erythema, tenderness, warmth, and a difference in calf diameters.
Prompt diagnosis and initiation of treatment can prevent further clot extension and pulmonary embolism. Anticoagulation therapy is indicated for patients with DVT and prompt referral to the orthopaedic department or A&E should be organised for further investigations.
Peroneal nerve palsy is the most common neurological complication after total knee replacement. It presents with numbness, paraesthesia and foot drop. The surgical dressings should be removed, and the patient should be referred back to the orthopaedic surgeon. Depending upon the symptoms a conservative approach may be followed or the nerve explored.
Restriction of movements
Patients may present with postoperative limitation of motion that results in functional impairment of the joint. Many factors can be responsible including malrotation of the prosthesis and poor preoperative range of movement. Treatment may comprise physiotherapy or manipulation under anesthesia.
Persistent pain and dissatisfaction
Although outcomes after total knee replacement are good, many patients continue to report pain and dissatisfaction.
Clinically significant persistent pain and dissatisfaction has been reported in 20% of patients.5 Night pain is quite common after knee replacement. Possible explanations for such pain include unrealistic expectations, technical flaws of the procedure and pain from other sites. If the pain is persistent without a known cause then referral to the pain management team should be made.
- Mr Waheed is senior knee fellow and Mr Dowd is consultant orthopaedic surgeon at The Royal Free and The Wellington Hospitals, London
1. SooHoo NF, Lieberman JR, Ko CY, Zingmond DS. Factors predicting complication rates following total knee replacement. J Bone Joint Surg Am 2006; 88(3): 480-5.
2. Claus A et al. Risk profiling of postoperative complications in 17, 644 total knee replacements. Unfallchirurg 2006; 109(1): 5-12.
3. Blom AW, Brown J, Taylor AH, Pattison G, Whitehouse S, Bannister GC. Infection after total knee arthroplasty. J Bone Joint Surg Br 2004; 86(5): 688-91.
4. Januel JM, Chen G, Ruffieux C, et al. Symptomatic in-hospital deep vein thrombosis and pulmonary embolism following hip and knee arthroplasty among patients receiving recommended prophylaxis: a systematic review. JAMA 2012; 307:294
5. Beswick AD, Wylde V, Gooberman-Hill R, et al. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open 2012; 2:e000435.