Table 1.
Description of the included studies in the systematic review investigating balance and risk of falls in TKR patients
| Sample | Outcome measures | Timeline | Study findings | Clinically relevant findings to balance and falls | |
|---|---|---|---|---|---|
| Cho and Hwang [12] | N = 11 (11F) No CG Age: 61.7±7.3 Inclusion: Radiographic varus deformity& medial compartment OA degeneration undergoing TKR | VAS; WOMAC; varus angle; SLSB in horizontal plane force platform maximum isometric peak torque of quadriceps | Pre-TKR and 11-day post-TKR | Improvements (~60%) in SLSB in patients with varus OA knees 11-day post-TKR | Improvement in SLSB post-TKR |
| Poor pre-TKR SLSB associated with better SLSB post-TKR. | |||||
| Gage et al. [15] | EG: n= 8(2 M,6F) Age: 62.9±6.0 CG: n=9(5 M,4F) Age: 62.1±5.6 Inclusion: post-TKR patients, first right TKR, at least 6 months after surgery | EMG and kinematic responses with rotational sagittal plane perturbation platform | At least 6 months post-TKR | Dynamic balance not impaired in EG vs CG in sagittal plane | No difference between groups in dynamic balance in sagittal plane |
| Whole body COM displacement not different between groups vs joint angle displacement and EMG => different strategy to maintain balance from CG. | |||||
| EMG and kinematic responses in EG are bilateral despite unilateral joint disease | |||||
| Gage et al. [16] | EG: n = 8(6F) Age: 62.9±6.0. CG: n=9(4F) Age: 62.1±5.6 Inclusion: post-TKR patients, first right TKR, at least 6 months after surgery | EMG and kinematic responses with rotational frontal plane perturbation platform | At least 6-month post-TKR | Dynamic balance control impaired in EG vs CG in frontal plane | Impaired dynamic balance of EG vs CG in frontal plane |
| Increased COM displacement in EG vs CG | |||||
| Differences in joint angle displacement and EMG of EG vs CG => different strategy to maintain balance from CG. | |||||
| EMG and kinematic responses amongst patients are bilateral despite unilateral joint disease | |||||
| Levinger et al. [29] | EG: n = 35 (16F) Age: 67±7. CG: n=27 (14F) Age: 65±11 Inclusion: patients with knee OA who could walk independently for 45 m undergoing TKR | QoL; WOMAC; Incidental and Planned Activity Questionnaire (IPAQ), Falls Efficacy Scale (FES-I), Physiological Profile Assessment (PPA) for falls risk | Pre-TKR & 4-month post-TKR | No significant difference in falls risk between groups post-TKR | Increased risk of falls in EG compared to CG. |
| No significant difference in postural sway between groups | Impaired SLSB of EG vs CG | ||||
| QoL: significant reduced post-surgery. | |||||
| Significant improvement in WOMAC post-TKR | |||||
| Less strength and poorer proprioception for the EG post-TKR compared with the CG | |||||
| Mandeville et al. [32] | EG: n= 19(14F) Age: 64.0±7.74. CG: n=21(13F) Age: 63.1±4.26 Inclusion: end-stage OA undergoing TKR | VAS; WOMAC; obstacle overcoming; kinematic displacement on force platform during gait | Within 2 pre-TKR weeks and 6-month post-TKR | Improvement in WOMAC post-surgery | Impaired dynamic balance in EG vs controls |
| Poorer gait stability in EG (smaller displacement COM/COG) than CG | |||||
| EG and CG cross obstacles similarly | |||||
| Mauer et al. [33] | EG: n=29(19F) Age 72, 6±5,4, bilateral (BL) TKR. CG: n=27(17F) Age 70, 6±5,5. Inclusion: knee OA who could climb stairs, rise form a chair, have 20/40 vision or better undergoing TKR | Balance (SLSB for 30 s); Obstacle avoidance success rate | EG tested post-TKR: 2,75±1,29 (range: 1–5 years) | EG SLSB duration was 67% less than the CG | Impaired SLSB in EG vs CG. |
| EG 30% less obstacle avoidance success rate than the CG | Increased risk of falls in EG vs CG | ||||
| McChesney and Woolacot [11] | N=22 Age:≥70 Groups: knee OA, ankle OA, patients undergoing TKR | TJPS; EMG and kinematic responses with force platform | Not stated | Ankle & knee groups with lower TJPS showed increased COP variance. | No difference on SLSB or dynamic between groups |
| Post-TKR patients showed no reductions in any aspect of postural control. | |||||
| Quagliarella et al. [43] | N=240(142F). EG1: n=81 THR Age range: 40–80/42–82 years EG2: n=100 TKR Age range: 48–80/48–79 years CG: N=59 Age 67.4±5,9. Patients able to stand without support for 120 s. | Posturography on force plate | Pre-op; 6 months &12 months post-TKR | No statistically significant improvement in posturographic parameters in EG1 & EG2 vs CG group at follow-ups post-TKR | Standing balance did not show a clear trend towards improvement in TKR patients post-TKR |
| Statistically significant improvement in pain and function of EG1 & EG2 post-TKR | |||||
| Posturography not recommended as a method to evaluate balance in TKR patients | |||||
| Schwartz et al. [45] | n=62(52F) mAge: 73 (r: 57–83). Inclusion: Knee OA patients able to walk & follow simple instructions undergoing TKR | Dynamic & static Balance with force platform; TUG; SF-36 | Pre-TKR & 12-month post-TKR | improved knee function& QoL | Significant improvement in dynamic and functional balance; NS for static balance |
| improved dynamic balance | |||||
| Improvements in static balance measures did not reach statistical significance. | |||||
| Improved weight-bearing during squat | |||||
| Swinkels et al. [54] | n= 99(63F) Age 73.4±4.9 Inclusion: primary TKR | falls number; WOMAC; ABC-UK; GDS | Pre-TKR and 12-month post-TKR | ~45% patients fall again in the first year post-TKR | Significant switch of pre-TKR fallers becoming non-fallers post-TKR |
| Improved balance confidence, WOMAC and GDS post-TKR | |||||
| Swinkels and Allain [53] | n=22 (16F/ Age: 74,8 ± 5,2y) Inclusion: primary TKR. | falls number; WOMAC, ABC, GDS; BBS; TUG | 2–50 day pre-TKR (mean: 23) 143–218 day post-TKR (mean: 183) | 41% of patients exceeded MDC for BBS post-surgery | Functional balance improved post-TKR in 54% of patients |
| 50 % of patients exceeded MDC for TUG post-surgery | |||||
| Findings on fallers are restricted by the small sample size | |||||
| Viton et al. [57] | 20 patients EG1: N=8(3F) Age: 67 (46–77) CG N=12(6F) Inclusion: Unilateral TKR | VAS; kinetics/kinematics in side step on force platform | 15-day pre -and 12-month post-TKR | Improved VAS | SLSB improved in operated limb during tasks |
| Presented with more symmetrical posturomotor strategies | |||||
| Evidence of persisting posturomotor impairments of EG vs CG | |||||
| Increased SLSB in operated limb in EG | |||||
| Yakhdani et al. [60] | EG1: n = 14(10F) Age 61.6±10. CG: n=12(7F) Age 62.0±12.6 Inclusion: Unilateral knee ΟΑ undergoing TKR, sufficient physical condition | Dynamic balance; falls; gait variability | pre-TKR, at 6 weeks, at 6- and 12-month post-TKR | EG1: increased maximum gait speed post-TKR | Reduced risk of falls. |
| Decreased gait variability of EG post-TKR in relevance to CG | Recovery of dynamic balance | ||||
| Increased stability post-TKR |
CG control group, EG experimental group, TKR total knee replacement, mCTSIB modified clinical test for sensory interaction and balance, TJPS threshold of passive joint position sense, ABC-UK activity balance confidence scale, GDS geriatric depression scale, BBS berg balance scale, MDC minimal detectable change, COP centre of pressure, COG centre of gravity, TUG timed up and go test, NS non significant