Clinical and objective gait outcomes remained stable seven years after total knee arthroplasty: A prospective longitudinal study of 28 patients

Gait kinematics and knee stability 10-years following posterior-stabilised total knee arthroplasty comparable to healthy adults >55

PURPOSE

The purpose of this study was to compare the long-term objective biomechanical and functional parameters of a high-flexion total knee arthroplasty (TKA) design against healthy older adults to determine whether knee biomechanics are comparable in both populations.

METHODS

One cohort of patients with a primary TKA, and a cohort of healthy adults over 55 years old with no musculoskeletal deficits or arthritis participated. Bilateral knee range of motion (RoM) was assessed with a goniometer, and gait patterns were analysed with a three-dimensional-motion capture system. An arthrometer quantified the anterior-posterior laxity of each knee. Statistical analyses were performed in SPSS software (α = 0.05).

RESULTS

Twenty-three knees were replaced in 20 patients. At 9.8 ± 3.1 years postoperatively, patients' knees had a statistically significantly poorer RoM than healthy controls' knees (n = 23) due to limited flexion; p < 0.0001. Patients also failed to achieve the same degree of knee flexion as controls during downhill gait. No kinematic differences were observed during mid-flexion in level nor downhill gait; a state that has been associated with instability (p = 0.614; not significant [n.s]). There were no differences between groups in knee laxity (n.s).

CONCLUSION

Patients in this study had similar gait patterns to healthy older adults during mid-flexion and were no more likely than the healthy controls to exhibit anterior-posterior translation of the knee > 7 mm; a known risk factor of instability. However, the knee flexion range was poorer. This likely led to bilateral pathological knee flexion patterns during downhill gait.

LEVEL OF EVIDENCE

Level III.

Alignment strategy for different types of varus knee with generic instruments: Mechanical alignment or kinematic alignment?

OBJECTIVE

A thorough examination of the available approaches is crucial to comprehensively understand the variance among the alignment strategies employed in total knee arthroplasty (TKA). In this study, we assessed the functional outcomes during the perioperative and postoperative periods of TKA in patients using generic instruments with varus knee to compare the mechanical alignment (MA) and kinematic alignment (KA) procedures.

METHODS

A total of 127 patients from the First Affiliated Hospital of Wannan Medical College who had undergone unilateral TKA between November 2019 and April 2021 were included. The patients with varus knee deformity were categorized into two groups [type I (n = 64) and type IV (n = 63)] based on the modified coronal plane alignment of the knee (mCPAK) classification. The type I and IV groups were further subdivided into MA (n = 30 and n = 32) and KA subgroups (n = 34 and n = 21), respectively. The clinical information collected included sex, surgical side, age, body mass index, and perioperative data [including operation time, intraoperative blood loss, length of hospital stay, and the American Society of Anesthesiologists (ASA) classification]. All patients were monitored for 12 months post-surgery to evaluate the recovery of knee joint function. During this period, the Knee Disability and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and the active range of motion (AROM) and visual analog scale (VAS) pain scores were compared at different time points, i.e., before the operation and 6 weeks, 6 months, and 12 months post-operation. Additionally, the patients' subjective experiences were assessed at 6 and 12 months post-surgery using Forgotten Joint Score Knee (FJS-12 Knee), while complications were recorded throughout the monitoring period.

RESULTS

No significant variances were observed in ASA classification, operation duration, blood loss volume during surgery, and hospital stay length between the patients who underwent KA TKA and those who received MA TKA (P > 0.05). During the initial 6 weeks post-operation, the KA group exhibited a significantly reduced average VAS pain score (P < 0.05), with no such differences at 6 months and 1 year after the surgery (P > 0.05). Furthermore, the KA group had significantly higher scores on the KOOS JR at 6 weeks, 6 months, and 1 year following the surgery (P < 0.05). Moreover, the AROM score of the KA group significantly improved only at 6 weeks after the surgery (P < 0.05); however, no prominent differences were found at 6 months and 1 year after the operation (P > 0.05). The KA cohort also exhibited a significant increase in FJS-12 Knee at 1 year following the operation (P < 0.05), whereas no such difference was detected at 6 months following the surgery (P > 0.05). Thus, compared to the MA method, the KA procedure provided pain relief and improved active motion range within 6 weeks after the surgery in patients undergoing TKA. Further, the KOOS JR exhibited significant increases at 6 weeks, 6 months, and 1 year while the FJS-12 Knee demonstrated a significant increase at 1 year after the KA TKA procedure.

CONCLUSION

Therefore, our study results suggest that the KA approach can be considered in patients using generic instruments with varus alignment of the knee, particularly those with mCPAK type I and IV varus knees, to help improve patient satisfaction.

The impact of Parkinson's disease on results of primary total knee arthroplasty

Parkinson’s disease (PD) is a common neurodegenerative disorder.

When patients with PD undergo total knee arthroplasty (TKA) for knee osteoarthritis, poorer knee function and poorer quality of life are obtained than in matched cohorts (MCs). However, the degree of patient satisfaction is usually high.

The mean length of stay is 6.5% longer in patients with PD than in MCs.

Compared with MCs, patients with PD undergoing TKA have a 44% higher risk of complications.

In patients with PD, the overall complication rate is 26.3% compared with 10.5% in MCs; the periprosthetic joint infection rate is 6.5% in patients with PD vs 1.7% in MCs; and the periprosthetic fracture rate is 2.1% in patients with PD vs 1.7% in MCs.

The 90-day readmission rate is 16.29% in patients with PD vs 12.66% in MCs. More flexion contractures occur in patients with PD.

The rate of medical complications is 4.21% in patients with PD vs 1.24% in MCs, and the rate of implant-related complications is 5.09% in patients with PD vs 3.15% in MCs. At 5.3 years’ mean follow-up, the need for revision surgery is 23.6%.

The 10-year implant survival, taking revision of any of the components as an endpoint, is 89.7% in patients with PD vs 98.3% in MCs.