Assessment of chronic postsurgical pain after knee replacement : a systematic review

Objective: Approximately 20% of patients experience chronic pain after total knee replacement (TKR), yet there is no consensus about how best to assess such pain. This systematic review aimed to identify measures used to characterise chronic pain after TKR. Methods: MEDLINE, Embase, PsycINFO, Cochrane Library and CINAHL databases were searched for research articles published in all languages from January 2002- November 2011. Articles were eligible for inclusion if they assessed knee pain at a minimum of 3-months after TKR, yielding a total of 1,164 articles. Data extracted included study design, country, timings of assessments, and outcome measures containing pain items. Outcome measures were compared with domains recommended by IMMPACT for inclusion in assessment of chronic pain related outcomes within clinical trials. Temporal trends were also explored. Results: The review found use of a wide variety of composite and single-item measures, with the American Knee Society Score most common. Many measures used in published studies do not capture the multi-dimensional nature of pain recommended by IMMPACT; of those commonly used, the WOMAC and Oxford Knee Score are most comprehensive. Geographical trends were evident, with nation-specific preferences for particular measures. A recent reduction in use of some clinically-administered tools was accompanied by increased use of patient-reported outcome measures. Conclusion: There was wide variation in methods of pain assessment alongside nation-specific preferences and changing temporal trends in pain assessment after TKR. Standardisation and improvements in assessment is needed to enhance the quality of research and facilitate the establishment of a core outcome set

Standardising the clinical assessment of coronal knee laxity

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements.Non- invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment. Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18Nm. Standardised laxity measurements had small standard deviations (within 1.1°) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3°) being slightly more consistent than varus (means of 4° or 5°).The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour

Retention of the posterior cruciate ligament versus the posterior stabilized design in total knee arthroplasty: a prospective randomized controlled clinical trial

Background: Prosthetic design for the use in primary total knee arthroplasty has evolved into designs that preserve the posterior cruciate ligament (PCL) and those in which the ligament is routinely sacrificed (posterior stabilized). In patients with a functional PCL the decision which design is chosen depends largely on the favour and training of the surgeon. The objective of this study is to determine whether the patient's perceived outcome and speed of recovery differs between a posterior cruciate retaining total knee arthroplasty and a posterior stabilized total knee arthroplasty. Methods/Design: A randomized controlled trial will be conducted. Patients who are admitted for primary unilateral TKA due to primary osteoarthrosis are included when the following inclusion criteria are met: non-fixed fixed varus or valgus deformity less than 10 degrees, age between 55 and 85 years, body mass index less than 35 kg/m(2) and ASA score (American Society of Anaesthesiologists) I or II. Patients are randomized in 2 groups. Patients in the posterior cruciate retaining group will receive a prosthesis with a posterior cut-out for the posterior cruciate ligament and relatively flat topography. In patients allocated to the posterior stabilized group, in which the posterior cruciate ligament is excised, the design may substitute for this function by an intercondylar tibial prominence that articulates with the femur in flexion. Measurements will take place preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. At all measurement points patient's perceived outcome will be assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcome measures are quality of life (SF-36) and physician reported functional status and range of motion as determined with the Knee Society Clinical Rating System (KSS). Discussion: In the current practice both posterior cruciate retaining and posterior stabilized designs for total knee arthroplasty are being used. To date no studies have been performed determining whether there is a difference in patient's perceived outcome between the two designs. Additionally, there is a lack of studies determining the speed of recovery in both designs as most studies only determine the final outcome. This randomised controlled study has been designed to determine whether the patient's perceived outcome and speed of recovery differs between a posterior cruciate retaining total knee arthroplasty and a posterior stabilized total knee arthroplasty

Comments on the article “Clinical and radiological outcomes of fixed- versus mobile-bearing total knee replacement: a meta-analysis”

Diagnosis and treatment of bone and soft tissue tumour

MOBILE and the provision of total joint replacement

Modern joint replacements have been available for 45 years, but we still do not have clear indications for these interventions, and we do not know how to optimize the outcome for patients who agree to have them done. The MOBILE programme has been investigating these issues in relation to primary total hip and knee joint replacements, using mixed methods research

Conversion of patellofemoral arthroplasty to total knee arthroplasty: A matched case-control study of 13 patients

Background and purpose The long-term outcome of patellofemoral arthroplasty is related to progression of femorotibial osteoarthritis with need for conversion to total knee arthroplasty. We investigated whether prior patellofemoral arthroplasty compromises the results of total knee arthroplasty

Cutting errors in total knee replacement: Assessment by computer assisted surgery

The observed errors in the position of the implanted prosthesis can be due to a number of potential causes. One of these is the potential error during execution of the bone cuts. However, there is only minimal information on this in the current literature. The amount of cutting errors in 40 consecutive total knee replacements was reported. All the operations were done by the same surgeon. The amount of cutting error was measured by the use of computer navigation system. It was hypothesized that there was no difference in the amount of error between bone cut through the cutting slot (slotted cutting) and bone cut done on the surface of the cutting guide (open cutting). It was found that the average absolute cutting error was 1° in the coronal plane and 1.4° in the sagittal plane. Significantly more outlier (more than 3°) was observed in the errors in the sagittal plane (P = 0.014, chi square test). Open cutting resulted in less error in the sagittal plane of the tibial cut when compared with slotted cutting (P = 0.031, Mann-Whitney U Test). This was attributed by the use of a thicker saw blade with higher stiffness in the open cutting method. © 2008 Springer-Verlag.postprin

ACL reconstruction with unicondylar replacement in knee with functional instability and osteoarthritis

Severe symptomatic osteoarthritis in young and active patients with pre-existing deficiency of the anterior cruciate ligament and severe functionally instability is a difficult subgroup to manage. There is considerable debate regarding management of young patients with isolated unicompartment osteoarthritis and concomitant ACL deficiency. A retrospective analysis of was done in 9 patients with symptomatic osteoarthritis with ACL deficiencies and functional instability that were treated with unicompartment knee arthroplasty and ACL reconstruction between April 2002 and June 2005. The average arc of flexion was 119° (range 85° to 135°) preoperatively and 125° (range 105° to 140°). There were no signs of instability during the follow up of patients. No patients in this group were reoperated. In this small series we have shown that instability can be corrected and pain relieved by this combined procedure