Kneeling function following total knee arthroplasty

Abstract

The ability to kneel is an important function of the knee joint, as it is required for many daily activities, including religious practices, professional occupations and recreational pursuits. The inability to kneel following total knee arthroplasty (TKA) is frequently a source of disappointment. This work investigates patients’ understanding of the term ‘kneeling’ and what proportion of patients can kneel before and after TKA, as well as identifying the factors that can affect the ability to kneel following TKA. The underlying hypothesis tested was: “There are no differences between kneeling ability before and after TKA”. Kneeling ability after TKA may be affected by many factors, including patient-specific factors, the extent of wear on RPC (Retro patellar Cartilage), postoperative AKP (Anterior Knee Pain) and post-operative ROM (Range of Motion). Thus a consecutive series of TKA patients were assessed to test the afore-mentioned hypothesis. In particular, the thesis has examined: • Interpretation of kneeling and perceptions of kneeling ability after TKA. • The extent of wear on Retro Patellar Cartilage (RPC) and its correlation to kneeling ability. • Sensory changes in the knee after TKA. • Preoperative and Postoperative Anterior Knee Pain (AKP) assessment. • The reality of kneeling ability before and after TKA. • Postoperative ROM of the knee and its correlation to kneeling function. The advice offered by healthcare professionals may contribute to a low postoperative rate of kneeling. The patellofemoral joint plays an essential role in knee function and a person’s kneeling ability, may be greatly affected by the performance of this joint. Firstly, this study analysed the responses of two samples of participants drawn from diverse cultural backgrounds (Christian and Muslim), it examined their primary interpretation of what kneeling constitutes, along with a subjective assessment of the importance of kneeling in their everyday lives. Secondly, it explored patients’ perceptions of their kneeling ability after TKA, with a comparative analysis of their responses to the kneeling questionnaire specifically constructed by the author and also the question in relation to kneeling in the Oxford Knee Score (OKS). The third component investigated retro-patellar cartilage (RPC) morphology using intraoperative examination and standardised photography. Fourthly, a cohort of patients listed for TKAs was followed prospectively, in order to assess their kneeling ability prior to and following treatment, along with identifying the factors that could affect this function, i.e. knee pain, range of motion, sensory changes and sensitivity to pain on the anterior aspect of the knee as assessed with dolorimetry. Differences were detected in the subjective interpretation of the kneeling function, as well as its importance, for the two diverse cultures involved in this study. Pain, as opposed to poor range of movement, was identified as the main reason which led to kneeling difficulties. The majority of respondents reported that it was either extremely difficult or impossible to kneel on the operated knee. The high flexed position (required for prayer in certain cultures) was the most difficult position to achieve for most of the patients. Prior to surgery, 30 patients were seen during this period, 15 (50%) out of 30 consecutive patients were unable to kneel in any position whatsoever. Of those who could kneel to some degree, the most common posture that they could achieve was the upright kneeling position. Considerable variations were found to occur in patients’ understanding of the term ‘kneeling’. Consequently, this has significant implications for the design and interpretation of questions in relation to kneeling for diverse cultures, which are characterised by distinct lifestyles. The current patient-based selfV administered questionnaires, such as the OKS, although useful as a simple measure of overall knee function, were found to have limitations as an effective assessment tool in the measurement of kneeling function either before or after TKA and indicate that there is a need for a culturally appropriate questionnaire to assess kneeling function. Retro-patellar cartilage lesions were very prevalent in patients undergoing TKA. However, no significant correlation existed between the total amount of retro-patellar cartilage wear and the ability to kneel. Patients were more likely to be able to kneel if the cartilage of the superior facets of the patella were disease free (P=0.02). At the six months post-surgery stage, of the 14 consecutive patients, who could kneel pre-operatively 6 were able to kneel post-operatively. Of the 13 consecutive patients who were unable to kneel pre-operatively, all were unable to kneel post-operatively. Knee pain was the main reason attributed to this difficulty. However, no link was found to occur between sensory changes and kneeling function in the patients who participated in the study, after TKA performed via an anterior midline incision.