Magnitude of Deformity Correction May Influence Recovery of Quadriceps Strength After Total Knee Arthroplasty

Functional characteristics of female patients based on ambulatory ability 1 year after total knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is commonly performed to reduce knee pain and improve physical function. Compared with the values for healthy, age-matched women, previous studies have reported large deficits in functional ability, such as muscle strength and ambulatory ability, in women 1 year post-TKA. Ambulatory ability is to move around, particularly by walking and is clinically assessed by the timed up and go test (TUG).

AIM

This study aimed to clarify the characteristics of knee functions in female patients whose ambulatory ability recovered to a normal level at 1 year after TKA.

METHODS

This cross-sectional study included 151 female patients who underwent TKA. The muscle strength of the lower extremity was measured, and the 2011 Knee Society Scoring (2011 KSS) system was used postoperatively. The TUG was conducted to assess ambulatory ability after TKA; then the patients were classified into the fast and slow ambulation groups based on previously reported gait-speed values of healthy female individuals. Then, we identified significant indicators of ambulatory ability at 1 year after TKA.

RESULTS

Forty-nine percent of patients after TKA achieved the level of ambulatory ability of a healthy female. Logistic regression analysis identified that the non-operative side knee extensor strength and the functional activity score, as assessed by the 2011 KSS, were variables significantly associated with the mid-term ambulatory ability after TKA.

CONCLUSION

Female patients with high non-operative knee extensor strength and a functional activity score at 1 year postoperatively can achieve better ambulatory ability than those of healthy, age-matched females.

Quadriceps muscle group function and after total knee arthroplasty-asystematic narrative update

BACKGROUND

This article systematically summarizes the present evidences, published in the last 20 years, regarding the pre- and post-operative factors, which may influence recovery of the function of the quadriceps muscle group following total knee arthroplasty (TKA). We following the PRISMA methodology, including meta-analyses and high-level evidence studies (prospective trials, and, when unavailable, retrospective studies).

SOURCES OF DATA

Pubmed and Cochrane databases: 582 articles were identified and 54 of them were selected.

AREAS OF AGREEMENT

Tourniquets inflated at high pressure exert a detrimental effect on the quadriceps muscle group. Faster quadriceps recovery takes place using mini-invasive approaches, an eight-week rehabilitation period including balance training and the use of nutraceuticals.

AREAS OF DISAGREEMENT

Pre-habilitation and pre-operative factors, analgesic methods and different TKA implants.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

Telerehabilitation seems a cost-effective tool for rehabilitation after TKA. Patients' optimization protocols before TKA should include standardized nutraceuticals intake.

Effectiveness of ultrasonographic skeletal muscle assessment in patients after total knee arthroplasty

Objectives

This study aimed to characterize the skeletal muscles of patients who underwent total knee arthroplasty (TKA) using ultrasonography in order to investigate the effectiveness of ultrasonographic skeletal muscle assessment after TKA.

Methods

This study included 50 TKA patients (TKA group) and 41 residents with osteoarthritis who have not received TKA (non-TKA group). Ultrasonography was used to assess the characteristics of several different muscles. Various postoperative outcomes were evaluated. Muscle thickness (MT) and echo intensity (EI) results were compared among operated knees in the TKA group, nonoperated knees in the TKA group, and more severely affected knees in the non-TKA group. For the TKA group, multiple regression was conducted to examine the association between skeletal muscle characteristics of operated knees and postoperative outcomes.

Results

The MTs of the vastus medialis, vastus intermedius, and rectus femoris (RF) were significantly smaller and the RF-EI was significantly greater for both operated and nonoperated knees in the TKA group compared with the non-TKA group (P < 0.017). Several parameters of physical function were significantly poorer in the TKA group than in the non-TKA group (P < 0.05). Multiple regression demonstrated that RF-MT was associated with knee range of motion, knee strength, and physical functional performance in the TKA group (P < 0.05).

Conclusions

The quantity and quality of skeletal muscles were lower in the TKA group than in the non-TKA group. Ultrasonography may be useful for assessing skeletal muscles in TKA patients because MT assessed with ultrasonography was associated with various parameters of physical function.

Weight-bearing radiography depends on limb loading

PURPOSE

The mechanical axis of the lower limb has shown to vary between different weight-bearing conditions and change after total knee arthroplasty (TKA). The purpose of this study was to investigate the correlation between mechanical axis alignment in standing long-leg radiographs and limb loading after TKA.

METHODS

Mechanical axis of the lower limb and limb loading have been prospectively evaluated in 115 patients 10 days and 3 months after TKA. By the moment of standing long-leg radiography for analysis of the mechanical leg axis, two digital scales separately captured the load of each limb.

RESULTS

Mechanical axis changed from an initial - 1° ± 2° valgus alignment to a varus axis of + 1° ± 2° (p < 0.01). This change in alignment was associated with an increase of limb loading from 89.9 ± 10.7 to 93.0 ± 7.0% (p < 0.01). The mechanical axis strongly correlated with relative limb loading at the first and second measurements (r = 0.804, p < 0.001, respectively, r = 0.562, p < 0.001). A significant change in the rate of outliers was registered within the observation period. These alterations and distinctions were much more pronounced in patients with postoperative incomplete extension (n = 15).

CONCLUSIONS

The postoperative mechanical axis correlates with limb loading. A clinical relevant change in frontal alignment of the lower limb is associated with increased limb loading after TKA. The actual mechanical axis can only be assessed at physiological limb loading in long-leg radiographs with complete extension at full weight bearing.

LEVEL OF EVIDENCE

Diagnostic study, Level II.

The relationship between lower extremity swelling, quadriceps strength, and functional performance following total knee arthroplasty

BACKGROUND

The relationships between swelling after total knee arthroplasty (TKA) and quadriceps strength and functional performance are poorly understood. Therefore, the aim of this study was to examine the relationships between lower extremity swelling, measured using bioelectrical impedance assessment (SF-BIA), and quadriceps strength and timed up and go (TUG) times following TKA.

METHODS

53 participants (64 ± 9.5 y/o, 43% male) undergoing primary unilateral TKA were recruited for the longitudinal observational study with repeated measures. Quantities of swelling were examined for contribution to two and six-week outcomes of strength and TUG time using hierarchical regression controlling for age, sex, and the baseline value of the dependent variable. Swelling was assessed using bioelectrical impedance assessment and quantified as the peak level of swelling and cumulative swelling (integral) over the post-TKA time window. Maximum isometric quadriceps strength (MVIC) was measured using a electromechanical dynamometer and participant functional performance measured using the TUG.

RESULTS

Neither peak swelling nor cumulative swelling significantly contributed to the variance of two-week quadriceps strength. At six weeks, peak swelling significantly improved the variance in maximal quadriceps strength by an additional four percent (p = 0.05), while cumulative swelling did not significantly contribute. Peak swelling significantly contributed to the variance in two-week (16%) and six-week (five percent) TUG times (p < 0.05), but the cumulative swelling did not.

CONCLUSIONS

Peak swelling represents a value of post-TKA swelling that is associated with strength and function. Reducing the peak level of swelling, occurring early after surgery, may improve patient functional recovery.

LEVEL OF EVIDENCE

Level II - Prospective observational study.