The aim of this study was to explore the pre-operative predictors of the function component of the WOMAC one year after total knee arthroplasty (TKA) using a hierarchical regression model.

The pre-operative and one year post-operative results of 71 patients with knee osteoarthritis who underwent TKA were analysed. First the correlation between the post-operative function component of the WOMAC and a range of pre-operative measures were calculated to determine the independent variables for the hierarchical regression model. Independent pre-operative measures which showed a significant correlation with post-operative function were then entered in the model. Pre-operative measures were divided into three types according to International Classification of Health: (i) Personal characteristics, (ii) body structures and function and (iii) Psychosocial variables.

The following pre-operative measures were correlated with post-operative function: Knee flexion (r=-0.254), extensor strength (r=-0.338), flexor strength (r=-0.257), mental health component of the SF36 (r=-0.304), Tampa scale (fear of movement), (r=0.261), the sense of helplessness due to pain (r=0.264) and Stanford arthritis Self-Efficacy Pain Scale (r=-0.343). This scale is a measure of the person's belief in their capability to cope with their arthritis pain. The higher the score the better the person's self-efficacy.

Only independent pre-operative measures were entered in the models. In step 0, we controlled for age and Body Mass Index (BMI), in step 1 we entered knee flexion and extensor strength (model 1) and in step 2 Self-Efficacy was entered in the model (model2). In model1 extensor strength was a significant predictor of post-operative function (beta =-0.242, p=0.028). In the final model (model3) pre-operative extensor strength (beta =-0.242, p=0.07) and Self-Efficacy (beta -0.266, p=0.046) were the strongest predictors of post-operative function.

This study aimed to answer the following two questions. Firstly, which activities do people waiting for a total knee arthroplasty rate as important? Secondly, does their self-rated performance of these activities improve after surgery?

High flexion designs are intended to provide a greater range of knee flexion and possibly improve flexion in stiff knees. This study assessed the effects of two implant designs. A posterior stabilised high flexion mobile bearing (MB) design vs a cruciate retaining standard fixed bearing (FB) design.

The aim of this study was to assess whether implant design has an effect on the functional outcome one year after total knee arthroplasty (TKA).

The aim of this study was to investigate the pre-operative factors predicting the knee range of motion during stair ascending and descending a year after total knee arthroplasty.

The pre-operative and one year post-operative results of fifty six patients with osteoarthritis were analysed. Range of knee motion during stair ascent and descent was recorded using electrogoniometry. Pre-operative measures were grouped in three different domains; the Demographic Domain with age and Body Mass Index (BMI), the Body Function Domain with knee range of motion in long sitting (ROMsit), Knee extensor moment, Pain on a Visual Analogue Scale and the stiffness component of the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and thirdly the Psychosocial Domain with the Tampa scale for ‘fear of movement’ (TSK) and the sense of helplessness due to pain. Hierarchical Multiple Regression was used to analyse the relative importance of measures grouped into the three domain blocks on range of motion of the operated knee during stair ascent and descent. Model 1 contained domain block 1, model 2 included domain blocks 1 and 2 and model 3 included domain blocks 1,2 and 3.

Learned helplessness was a significant predicting factor for stair descent (beta; −0.538, p=0.025) while for stair ascent, age (beta 0.375, p=0.005) and ROMsit (beta 0.365, p=0.021) were significant predicting variables.

These results show that postoperative stair ascent and descent are predicted by different pre-operative factors. For stair ascent the demographic factors age and function factor ROM are important, while for stair descent, only the addition of the psychosocial factors in model 3 resulted in a significant change. These results indicate that treatment of patients with end-stage osteoarthritis should not only be aimed at improving range of motion of the knee but should also take into account psychosocial variables such as a sense of helplessness due to pain.

The primary aim of this study was to investigate whether objective daily physical activity, measured using an activity monitor one year after Total Knee Arthroplasty was different from that measured before surgery.

An activity monitor (activPAL) which records the number of steps in addition to the time spent sitting or lying, standing and ‘stepping’ was used to quantify physical activity. Forty-five patients with osteoarthritis (average 69.8 years old) were assessed an average of 38 days before and 368 days after total knee arthroplasty-before. A group of 40 age matched controls were also recruited. In addition to objective daily physical activity, knee range of motion, pain using the visual analogue score and the Western Ontario McMaster University Osteoarthritis Index (WOMAC 3.1) were also recorded before and after surgery.

Patients reported a significant decrease in pain (54%, p< 0.001) and increase in function (62% p< 0.001) after surgery. However, measures of physical activity showed much smaller improvements which were mostly statistically non-significant. The number of steps taken on one day increased by 19% (from 6438 to 7634 steps, p=0.119) and time spent stepping increased from 7.9% to 8.7% (p=0.27). Only average cadence and estimated energy expenditure were statistically significantly higher after surgery, 8% improvement, p=0.003 and 8% improvement, p=0.026 respectively. Stepwise regression analysis showed that only 11.4% of the improvement in physical activity was due to the decrease in pain.

One year after TKA levels of physical activity were still significantly (p< 0.05) lower than those of a group of age matched controls. In conclusion, other factors not measured in this study are to a large part determining the amount of physical activity in patients after knee surgery. Future studies aiming to identify those factors are warranted.

The aim of this study was to investigate the effects of implant design and gender on the outcome of Total Knee Arthroplasty (TKA) in patients with osteoarthritis (OA).

In this double blind randomised controlled trial, patients with OA received either a standard posterior stabilised implant (n=28) or high flex version of this implant (n=28). Walking speed, knee flexion under anaesthesia (‘drop test’), knee flexion in sitting and during functional activities as measured by electrogoniometry, daily number of steps, Quality of Life (SF36), the function component of the Knee Society Score, pain (Visual Analogue Score) and extensor strength were measured before and one year after TKA.

Type of implant did not have a significant effect on any of the outcome measures recorded, while gender showed significant effects both before and after surgery. Before surgery, females had a significantly lower knee range of motion, (both passive and functional), lower Knee Score function component, walking speed and strength. After surgery they had a statistically significant lower range of knee motion during functional activities such as walking up and down a slope. Strength was also still significantly lower but post-operative self-reported function were similar for both genders. There was also no difference between male and female participants regarding Quality of life, objective daily physical activity or pain.

The results of this study showed that there is a clinically and statistically significant difference between the function of female and male patients both before and after total knee arthroplasty. Although female patients seem to benefit more from TKA than males, on average they do not achieve the same functional knee motion after surgery. Unlike gender, implant design did not influence the knee motion or function in this group of patients. This has important implications for future research and treatment planning in order to maximise the functional outcome after TKA.

Objective: To evaluate the impact of soft tissue release on range of movement following total knee replacement.

Methods: Sixty four patients underwent PFC sigma total knee replacement through a medial arthrotomy. Range of active movement was measured preoperatively, and maximal flexion was measured after implantation, using the drop test while the patient was under anaesthetic. Soft tissue release was graded from 1 to 5, depending on the structures released.

Range of movement was correlated with extent of soft tissue release, to see if release had any impact on increase in range of movement.

Results: All patients had an improvement in range of movement following surgery. Post operative range of movement correlated strongly with preoperative ROM.

Patients requiring extensive releases tended to have less preoperative ROM, but the gain was independent of medial release. Those requiring extensive posterior release had poorer preoperative movement, and significantly less improvement.

In those requiring an extensive medial release, a posterior release improved gain in ROM.

Conclusion: Postoperative ROM following TKR is independent of extent of medial release. In patients requiring extensive medial release, a posterior release improves gain in movement.

Objective: To evaluate the impact of soft tissue release on range of movement following total knee replacement.

Methods: Sixty four patients underwent next-gen (Zimmer) posterior stabilising total knee replacement through a medial arthrotomy. Range of active movement was measured preoperatively, and maximal flex-ion was measured after implantation, using the drop test while the patient was under anaesthetic. Soft tissue release was graded from 1 to 5, depending on the structures released.

Range of movement (ROM) was correlated with extent of soft tissue release, to see if release had any impact on increase in range of movement.

Results: All patients had an improvement in range of movement following surgery. Post operative range of movement correlated strongly with preoperative ROM. Patients requiring extensive releases tended to have less preoperative ROM, but the gain was independent of medial release. Those requiring extensive posterior release had poorer preoperative movement, and significantly less improvement.

In those requiring an extensive medial release, a posterior release improved gain in ROM.

Conclusion: Postoperative ROM following TKR is independent of extent of medial release. In patients requiring extensive medial release, a posterior release improves gain in movement.

Purpose: This study aims to explore the role of pain, fear of movement and learned helplessness on functional knee range of motion and daily functioning in a patients awaiting total knee arthroplasty (TKA)

Methods and results: Sixty-five patients (mean age 69 years old) with osteoarthritis were assessed an average of 37 days prior to TKA. Dynamic knee angle was measured during 11 functional activities including getting up from a chair and walking up and down a slope and stairs using flexible electrogoniometry. Function was assessed using the function components of the Knee Society Score (KSS) and the Western Ontario & McMaster University Osteoarthritis Index (WOMAC). Other self-report measures included the 8 item Tampa scale for kinesiophobia to assess ‘activity avoidance’ (TSK-AA), and the 5 item Helplessness subscale of the rheumatology attitudes index.

The pain component of the WOMAC was negatively associated with the knee angle during sitting down and getting up from a low chair and stepping in and out of a bath (r=0.40–0.45), but not with the peak knee angle during ascending and descending a slope or walking speed. Higher scores of the activity avoidance and the helplessness scales however, were associated with reduced knee angles during descending a slope and a slower walking speed (r=0.31–0.38). Both psychosocial scales were also associated with function (r=0.39–0.45). Another important finding was that activity avoidance was not associated with pain.

Conclusions: Not only pain but also fear of movement and learned helplessness play a role on specific components of knee function in patients with final stage osteoarthritis of the knee. Further research into the impact of pain and psychosocial variables on functional outcome in ostearthritis is indicated.

Introduction: Transmalleolar axis (TMA) measurements are frequently used as a means of determining tibial torsion.

Material & Methods: The agreement between the prone, Edinburgh footprint and Dundee jig methods of measuring the TMA, and the repeatability of each method were investigated. The left and right limbs of 12 normal subjects (3 male, 9 female age range 21–61 years, mean age 38) were measured using the following three methods. The measurements were repeated for 6 subjects between 5 and 10 days later. All measurements were undertaken by the same assessors. The mean TMA values and repeatability of each method, and the agreement between the measures was as follows:

Results: Negative is external.

Discussion: Clinical methods will always include measurement errors, and a true TMA value may only be obtained from radiological or ultrasound methods. The position of the foot when marking the line for the prone method was very critical. The jig method produced lower values than those found previously. The Edinburgh footprint method proved the most repeatable of all three methods. There was poor agreement between the methods suggesting they should not be used interchangeably.