Advanced functional biomechanical analysis of medial rotation knee arthroplasty

Gwenllian Fflur Tawy, Philip Rowe, Leela Biant

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)
9 Downloads (Pure)


Background: The Medacta GMK-Sphere total knee arthroplasty (TKA) is designed to mimic the movements and stabilimidty of a natural knee for optimal post-operative function and mobility. This study aimed to quantify the early functional outcome of patients with this implant. Methods: Patients due to undergo TKA to treat end-stage osteoarthritis were recruited into this study. Functional tests of knee range of motion (ROM), strength, and gait kinematics were carried out pre-operatively and one year post-operatively at routine clinics. Motion capture technology and a force transducer were used to collect all data. Normality tests were completed on all data sets to confirm normal distribution of the data, then paired t-tests were used to statistically compare the results. The level of significance was set as α = 0.05. Results: Sixty-three patients underwent pre-operative assessments; of which 30 returned one year post-operatively and consented to have follow-up testing. The operative knee was found to have poorer function than the contralateral knee pre-operatively (p < 0.05). Post-operatively, knee ROM significantly improved on the operative side to a mean of 116.1 ± 19.0. Gait kinematics also improved, especially in the frontal plane, but some abnormal traits remained in the sagittal plane. Knee strength decreased post-operatively. Conclusions: The Medacta GMK-Sphere TKA improves knee range of motion sufficiently within the first postoperative year to allow patients to carry out most activities of daily living (> 110° knee flexion), but continued poor knee strength may limit their abilities to complete tasks which are more biomechanically demanding than walking.

Original languageEnglish
Pages (from-to)854-862
Number of pages9
Issue number3
Early online date7 Feb 2020
Publication statusPublished - 1 Jun 2020


  • total knee arthroplasty
  • functional outcome
  • biomechanics
  • range of motion
  • strength
  • gait


Dive into the research topics of 'Advanced functional biomechanical analysis of medial rotation knee arthroplasty'. Together they form a unique fingerprint.

Cite this