SA Orthopaedic Journal
versión On-line ISSN 2309-8309
versión impresa ISSN 1681-150X
HASSABALLA, MA; GBEJUADE, HO; PORTEOUS, AJ y MURRAY, JR. The effect of joint line restoration on kneeling ability after primary total knee replacement. SA orthop. j. [online]. 2012, vol.11, n.3, pp.79-83. ISSN 2309-8309.
BACKGROUND: Total knee replacement (TKR) surgery has become one of the commonest orthopaedic procedures undertaken. Pain relief and restoration of function are two major expectations following knee arthroplasty. Kneeling is a knee function required for many types of occupation and activities of daily living, making its restoration following knee arthroplasty essential. Restoration of joint line position is a surgical factor that has been reported to have an important impact on functional outcome after TKR. MATERIALS AND METHODS: We reviewed 100 (43 males and 57 females; with a mean patient age of 71 years) consecutive cemented Kinemax Plus TKRs (Stryker, Newbury, UK) performed in our unit with a minimum follow-up of two years. Joint line measurements were made on the pre-operative and post-operative X-rays. The kneeling ability component of the Oxford Knee Score questionnaire was analysed for all patients. The pre- and post-operative Oxford Knee Scores were prospectively recorded. Patients' ranges of movement (ROM) were measured. RESULTS: The mean pre-operative ROM for the group was 82° (std ± 15). Post-operatively, the mean ROM for the whole group was 109° (std ± 8). A joint line within ± 5 mm of the pre-operative measurement was considered 'restored' and more than 5 mm was considered 'elevated. Seventy-five per cent of patients had the joint line restored within 5 mm of their native joint line post-operatively. The mean ROM for restored and elevated groups was 116° and 108° respectively. This difference was statistically significant (P < 0.01). However, there was no significant difference in the total Oxford Knee Score between the groups. CONCLUSION: Seventy-five per cent of cases in this study showed a restored joint line position. In this group, the ROM was better than in the group with elevated joint line (116° for restored joint line versus 108° for elevated joint line). This study showed that restoring the joint line had a positive impact on the post-operative ROM and kneeling ability. However, kneeling ability can be affected by other factors and further studies are necessary to fully investigate this complex function of the knee joint.
Palabras clave : kneeling; total knee replacement; joint line restoration; range of motion.