Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively.Aims
Methods
Patients with skeletal dysplasia are prone to
developing advanced osteoarthritis of the knee requiring total knee replacement
(TKR) at a younger age than the general population. TKR in this
unique group of patients is a technically demanding procedure owing
to the deformity, flexion contracture, generalised hypotonia and ligamentous
laxity. We retrospectively reviewed the outcome of 11 TKRs performed
in eight patients with skeletal dysplasia at our institution using
the Stanmore Modular Individualised Lower Extremity System (SMILES)
custom-made rotating-hinge TKR. There were three men and five women
with mean age of 57 years (41 to 79). Patients were followed clinically
and radiologically for a mean of seven years (3 to 11.5). The mean
Knee Society clinical and function scores improved from 24 (14 to
36) and 20 (5 to 40) pre-operatively, respectively, to 68 (28 to
80) and 50 (22 to 74), respectively, at final follow-up. Four complications
were recorded, including a patellar fracture following a fall, a
tibial peri-prosthetic fracture, persistent anterior knee pain,
and aseptic loosening of a femoral component requiring revision.
Our results demonstrate that custom primary rotating-hinge TKR in
patients with skeletal dysplasia is effective at relieving pain,
with a satisfactory range of movement and improved function. It compensates
for bony deformity and ligament deficiency and reduces the likelihood
of corrective osteotomy. Patellofemoral joint complications are
frequent and functional outcome is worse than with primary TKR in
the general population.
