A comparison of utilization and short-term complications of technology-assisted versus conventional total knee arthroplasty

Effect of joint-line obliquity on long-term survivorship of total knee arthroplasty: A postoperative phenotype analysis

PURPOSE

Whether the longevity of total knee arthroplasty (TKA) differs between postoperative phenotypes has not been investigated. This study aims to examine which phenotype has a worse long-term survival rate than the reference phenotype (neutral alignment-parallel joint line), and whether joint-line obliquity (JLO) affects the survivorship of TKA.

METHODS

A total of 945 knees that underwent primary TKAs for primary osteoarthritis from January 2000 to January 2009 were included. These were classified into nine postoperative phenotypes based on the combined assessment of the hip-knee-ankle (HKA) angle and JLO, measured on standing radiographs. The 5-, 10- and 15-year survival rates were analysed using Kaplan-Meier methods and log-rank tests. The long-term survival rates of each phenotype were compared with the reference phenotype.

RESULTS

There were 55 aseptic mechanical failures within a period of 10.4 ± 5.0 years. The most frequently observed phenotypes were the reference phenotype (n = 527), neutral alignment-lateral joint-line inclination (n = 162), varus alignment-lateral joint-line inclination (n = 104) and varus alignment-parallel joint line (n = 101). The overall failure rate for each phenotype was 3.6%, 3.7%, 18.3% and 7.9%, respectively. Only the 10- and 15-year survival rates of the varus alignment-lateral joint-line inclination phenotype were significantly different from those of the reference phenotype (97%-93% vs. 90%-69%; p = 0.017, <0.001).

CONCLUSION

The lateral joint-line inclination phenotype had an inferior long-term survival rate after varus-aligned TKA. This suggested that alignment and JLO affected the long-term survival rate of patients who underwent TKA.

LEVEL OF EVIDENCE

Level III, Retrospective cohort study.

Preoperative phenotype has no significant impact on the clinical outcomes and long-term survival of mechanically aligned total knee arthroplasty in Asian patients with osteoarthritis

Aims

The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral.

Methods

The study involved 945 TKAs, which were performed in 641 patients with primary OA, between January 2000 and January 2009. These were classified into 12 phenotypes based on the combined assessment of four categories of the arithmetic hip-knee-ankle angle and three categories of actual joint line obliquity. The rates of survival were analyzed using Kaplan-Meier methods and the log-rank test. The Hospital for Special Surgery score and survival of each phenotype were compared with those of the reference phenotype with neutral alignment and a parallel joint line. We also compared long-term survival between the unchanged phenotype group and the corrected to neutral alignment-parallel joint line group in patients with Type IV-b (mild to moderate varus alignment-parallel joint line) phenotype.

Results

The most common phenotype was Type I-b (mild to moderate varus alignment-medial joint line; 27.1% (n = 256)), followed by Type IV-b (23.2%; n = 219). There was no significant difference in the clinical outcomes and long-term survival between the groups. In Type IV-b phenotypes, the neutrally corrected group showed higher 15-year survival compared with the unchanged-phenotype group (94.9% (95% confidence interval (CI) 92.0 to 97.8) vs 74.2% (95% CI 98.0 to 100); p = 0.020).

Conclusion

Constitutional varus was confirmed in more than half of these patients. Mechanically aligned TKA can achieve consistent clinical outcomes and long-term survival, regardless of the patient's phenotype. The neutrally corrected group had better long-term survival compared with the unchanged phenotype group.

Robotics and Navigation Do Not Affect the Risk of Periprosthetic Joint Infection Following Primary Total Hip Arthroplasty: A Propensity Score-Matched Cohort Analysis

BACKGROUND

The use of computer navigation or robotic assistance during primary total hip arthroplasty (THA) has yielded numerous benefits due to more accurate component positioning. The utilization of these tools is generally associated with longer operative times and also necessitates additional surgical equipment and personnel in the operating room. Thus, the aim of this study was to evaluate the impact of technology assistance on periprosthetic joint infection (PJI) after primary THA.

METHODS

We retrospectively reviewed the records for 12,726 patients who had undergone primary THA at a single high-volume institution between 2018 and 2021. Patients were stratified by surgical technique (conventional THA, computer-navigated THA [CN-THA], or robotic-assisted THA [RA-THA]) and were matched 1:1 with use of propensity score matching. Univariate and logistic regression analyses were performed to compare the rates of PJI within 90 days postoperatively between the cohorts.

RESULTS

After propensity score matching, there were 4,006 patients in the THA versus RA-THA analysis (2,003 in each group) and 5,288 patients in the THA versus CN-THA analysis (2,644 in each group). CN-THA (p < 0.001) and RA-THA (p < 0.001) were associated with longer operative times compared with conventional THA by 3 and 11 minutes, respectively. The rates of PJI after conventional THA (0.2% to 0.4%) were similar to those after CN-THA (0.4%) and RA-THA (0.4%). On the basis of logistic regression, the development of PJI was not associated with the use of computer navigation (odds ratio [OR], 1.8 [95% confidence interval (CI), 0.7 to 5.3]; p = 0.232) or robotic assistance (OR, 0.9 [95% CI, 0.3 to 2.3]; p = 0.808).

CONCLUSIONS

Despite longer operative times associated with the use of computer navigation and robotic assistance, the use of these tools was not associated with an increased risk of PJI within 90 days after surgery.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The degree of C-reactive protein elevation after total knee arthroplasty is related to bone and medullary injury rather than soft tissue

First, we want to find out whether computer-assisted surgery (CAS) for total knee arthroplasty (TKA), which does not require opening the femoral medullary canal, results in a lesser C-reactive protein (CRP) level increase postoperatively compared to manual TKA. Second, they seek to examine whether the CRP reduction in CAS TKA and manual TKA follows a similar pattern within the first 2 weeks after surgery. Third, the study aims to compare and analyze the CRP levels in 3 different groups: CRP levels in CAS TKA with surgeons who started TKA surgery by CAS, CRP levels in manual TKA by surgeons with little experience, and CRP levels in skillful manual TKA performed after conducting over 200 cases. The 3 patient groups were as follows. Group 1: Patients who underwent non expertized surgeon CAS TKA (N = 63). Group 2: Patients who underwent manual TKA after surgeon CAS TKA experience (N = 108). Group 3: Patients who underwent manual TKA after surgeon 200 cases or more of either CAS TKA or manual TKA experience (more skillful manual TKA) (N = 66). CRP levels were analyzed using electronic medical records for 3 time points: within 3 months before surgery, 5 days after surgery, and 11 days after surgery. There were no statistically significant differences in pre operative CRP values among the 3 groups. At 5 days after surgery, the CRP level were 48.59 ± 32.75 for CAS TKA, 69.82 ± 42.76 for early manual TKA, and 67.73 ± 44.00 for skillful manual TKA, indicating a statistically significant lower CRP level in the CAS TKA group compared to the manual TKA groups (P = .01). At 11 days after surgery, there were no statistically significant differences in CRP level among the 3 groups, with was 12.12 ± 9.74 for CAS TKA, 14.07 ± 13.18 for early manual TKA, and 11.43 ± 11.45 for skillful manual TKA. The degree of CRP elevation after TKA is related to bone and medullary injury rather than soft tissue.

The development of machine learning algorithms that can predict patients satisfaction using baseline characteristics, and preoperative and operative factors of total knee arthroplasty

BACKGROUND

Patient satisfaction following primary total knee arthroplasty (TKA) is a crucial part to evaluate the success of the procedure. The purpose of this study was to develop to predict patient satisfaction following TKA.

METHODS

Satisfaction outcome data after 435 consecutive conventional TKAs performed between August 2020 and December 2021 were retrospectively collected. The total 26 input data were collected. The most favorable algorithm was first found using logistic regression (LR) and machine learning (ML) algorithms. To evaluate the predictive performance of the models, both area under curve (AUC) and F1-score were used as the primary metrics. The shapley additive explanations (SHAP) feature explanation in XGBoost and LR analysis were performed to interpret the model.

RESULTS

The performance of extreme gradient boosting classifier (XGBoost) was only higher than that of conventional LR in AUC (0.782 vs. 0.689). Comparing the F-1 score, only XGBoost showed better performance than LR (0.857 vs. 0.800). The most predictive feature in XGBoost was Short Form-36 physical and mental component summary scores (SF-36 MCS), followed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, Bone mineral density (BMD). In the LR analysis, lumbar spine disease, WOMAC pain, and BMD were statistically significant.

CONCLUSION

XGboost showed the best performance and was superior to conventional LR in the prediction of patient satisfaction after TKA. The SF-36 MCS was the most important feature in the ML model. WOMAC pain and BMD were meaningful variables and demonstrated a linear relationship with satisfaction in both the LR and ML models.

LEVEL OF EVIDENCE

Retrospective cohort study; Level of evidence 3.

Restoration of the Joint Line Configuration Reproduces Native Mid-Flexion Biomechanics after Total Knee Arthroplasty: A Matched-Pair Cadaveric Study

Background: Recent evidence supports that restoration of the pre-arthritic condition via total knee arthroplasty (TKA) is associated with improved post-TKA performance and patient satisfaction. However, whether the restored pre-arthritic joint line simulates the native mid-flexion biomechanics remains unclear. Objective: We performed a matched-pair cadaveric study to explore whether restoration of the joint line via kinematically aligned (KA) TKA reproduced native knee biomechanics more accurately than the altered joint line associated with mechanically aligned (MA) TKA. Methods: Sixteen fresh-frozen cadaveric knees (eight pairs) were affixed onto a customized knee-squatting simulator for measurement of femoral rollback and medial collateral ligament (MCL) strain during mid-flexion. One knee from each cadaver was randomly designated to the KA TKA group (with the joint line restored to the pre-arthritic condition) and the other to the MA TKA group (with the joint line perpendicular to the mechanical axis). Optical markers were attached to all knees and rollback was analyzed using motion capture cameras. A video extensometer measured real-time variations in MCL strain. The kinematics and MCL strain prior to and following TKA were measured for all specimens. Results: KA TKA was better for restoring the knee kinematics to the native condition than MA TKA. The mid-flexion femoral rollback and axial rotation after KA TKA were consistently comparable to those of the native knee. Meanwhile, those of MA TKA were similar only at ≤40° of flexion. Furthermore, KA TKA better restored the mid-flexion MCL strain to that of the native knee than MA TKA. Over the entire mid-flexion range, the MCL strain of KA TKA and native knees were similar, while the strains of MA TKA knees were more than twice those of native knees at >20° of flexion. Conclusions: The restored joint line after KA TKA effectively reproduced the native mid-flexion rollback and MCL strain, whereas the altered joint line after MA TKA did not. Our findings may explain why patients who undergo KA TKA experience superior outcomes and more natural knee sensations during daily activities than those treated via MA TKA.