Comparison of the outcomes of navigation-assisted revision of unicompartmental knee arthroplasty to total knee arthroplasty versus navigation-assisted primary TKA

How to manage and avoid revision after unicompartmental knee arthroplasty?

The article by Zhao et al presents a retrospective case series on the reasons for initial revision after unicompartmental knee arthroplasty (UKA). Clarifying the reasons that may cause UKA revision can further reduce the rate of revision UKA, focusing on gasket dislocation, osteophytes, intra-articular loose bodies, and tibial prosthesis loosening. This article provides valuable insights, not only by detailing the revision status of 13 patients who underwent revision after initial UKA but also by providing a comprehensive analysis of the incidence of revision after initial UKA. By reviewing and analyzing the causes, they established references for the early detection of risk factors for revision in clinical practice and for formulating surgical strategies and rehabilitation programmes. This commentary emphasizes the need for a meticulous understanding and an analysis of the revision rate following initial UKA and related management strategies. The implant rates, regional variation, and benefits of uncemented Oxford UKA have been explored, particularly in terms of bone preservation, appropriate surgical techniques, and weight management to control complications and improve patient prognosis.

Robotic-arm-assisted conversion of unicompartmental knee arthroplasty to total knee arthroplasty

Introduction

The purpose of this study was to describe a novel robotic-arm-assisted UKA to TKA conversion technique and evaluate the patient reported and clinical outcomes in these patients.

Methods

A retrospective review between 2017 and 2022 was conducted of patients that underwent robotic-arm-assisted UKA to TKA conversion. Charts were reviewed for patient demographics, indications for conversion from UKA to TKA, operative technique, implants used, postoperative complications, and patient-reported outcome measures (PROMs). The surgical technique resembles that of primary TKA, with the major exception of registering the robotic arm with retained UKA implants and removing the implants only when verification is complete. There were 44 robotic-arm-assisted UKAs in 41 patients were included in the study. Indications for UKA conversion to TKA included: 33 patients who had osteoarthritis progression (75%), 7 aseptic loosening (16%), 2 unspecified pain (4.5%), 1 polyethylene wear (2.3%), and 1 prosthetic joint infection (2.3%). Uncemented cruciate-retaining (CR) implants were used in 38 of the 44 robotic-arm-assisted TKAs (86.5%). The other six utilized cemented implants: four CR femurs (9.1%), six tibial baseplates (13.6%), four tibial stems (9.1%), and four medial tibial augments (9.1%).

Results

The PROMs significantly improved at 1-year follow-up, with the average KOOS JR score increasing from 48.1 to 68.7 (P < 0.001), and the r-WOMAC score decreasing from 25.7 to 10.6 (P = 0.003). Two patients developed prosthetic joint infections (4.5%), one developed aseptic loosening of the femoral component (2.3%), and one developed a superficial surgical site infection requiring superficial irrigation and debridement (2.3%). Overall survivorship was 93.18% at 1.8 years, and aseptic survivorship was 97.73%.

Conclusion

Robotic-arm-assisted UKA to TKA conversion exhibited improved patient-reported outcomes and low revision and complication rates. Improved implant placement achieved with robotic-arm-assistance may improve the functional and clinical outcomes following these surgeries.

Total Knee Arthroplasty after Previous Ipsilateral Hip Arthroplasty Showed Lower Clinical Outcomes and Higher Leg Length Discrepancy Perception

The purpose of this study is to compare perception of leg length discrepancy (LLD) and clinical results of total knee arthroplasties (TKA) in patients with or without previous ipsilateral hip arthroplasty. Between 2008 and 2015, navigation-assisted TKA was performed in 43 patients with previous hip arthroplasty after hip fracture. After 1:3 propensity score matching was performed, 108 patients of primary navigation-assisted TKA (group 1) and 36 patients with hip arthroplasty (group 2) were included. Knee Society (KS) scores, Western Ontario and McMaster Universities Index (WOMAC) scores, and patients' satisfaction including perception of LLD were evaluated. Radiographic evaluation included mechanical axis, component position, and LLD. Logistic regression analysis was performed to find the factors that affect the clinical outcomes. No significant differences in radiologic and clinical evaluations, except for KS function score, patient's satisfaction and LLD (p< 0.001), were detected between the groups. LLD and its perception were significantly higher in group 2 (1.8 ± 3.4 mm in group 1 and 9.7 ± 4.1 mm in group 2, p = 0.000). Risk factors for the low KS function score were found as LLD (odds ratio [OR]: 1.403, p = 0.008) and previous hip arthroplasty itself (OR: 15.755, p = 0.002), but much higher OR was found in previous hip arthroplasty. Although the outcomes of TKA in patients with ipsilateral hip arthroplasty are comparable to those of primary TKA, LLD was high and patient's satisfaction and functional outcomes were low in patients with previous ipsilateral hip arthroplasty. Care should be taken when considering TKA in patients with previous hip arthroplasty. This is a Level III, case control study.

Bearing failure in a mobile bearing unicompartmental knee arthroplasty: an uncommon presentation of an implant-specific complication

BACKGROUND

We present two cases of unicompartmental knee arthroplasty (UKA) bearing failure in this report-one case of bearing dislocation and one case of bearing fracture. The causes of failure in both cases are evaluated in depth and recommendations are provided regarding intraoperative technique to reduce risk of bearing failure in mobile bearing UKAs.

CASE PRESENTATION

In the first case, intraoperative evidence of metallosis and chronic pain preceding the traumatic event may indicate that the patient had attenuation of her collateral ligaments that precipitated the instability event. In the second case, the relatively atraumatic nature of the bearing fracture-dislocation and intraoperative evidence of extensive poly wear suggest that the bearing fracture was likely due to a 3-mm bearing selection in the initial surgery.

CONCLUSIONS

This case report shows that late bearing in mobile bearing unicompartmental knee arthroplasty can often be a multifactorial event and treatment must address all the risk factors that led to bearing dislocation. Bearing fracture is a very rare complication associated with mobile bearing UKA and patients with thin polyethylene inserts are at risk for bearing fracture even in the absence of poly wear.

Does anxiety influence the prognosis of percutaneous transforaminal endoscopic discectomy in the treatment of lumbar disc herniation? A preliminary propensity score matching analysis

PURPOSE

Previous reports revealed a correlation between psychological problems and spinal surgery. There is a lack of knowledge on the effect of anxiety on the percutaneous transforaminal endoscopic discectomy (PTED) outcome at the two year follow-up. The purpose of this study is to investigate changes in anxiety after PTED among patients with lumbar disc herniation (LDH), to compare the effect of anxiety on the prognosis using propensity score matching analysis, and to identify the related parameters of anxiety.

METHODS

A total of 145 patients with LDH requiring PTED surgery were included. Twenty-six LDH patients with anxiety were matched with 26 control patients utilizing propensity score matching analysis. The demographic and peri-operative data were collected and analyzed. A correlation analysis was utilized.

RESULTS

Both groups achieved significant improvements in visual analogue scale (VAS) scores for pain, Japanese Orthopedic Association (JOA) scores for neurological deficit, and 36-item Short-Form Health Survey (SF-36) scores and Oswestry Disability Index (ODI) scores for quality of life. A statistical difference was detected between the pre-operative and the post-operative Zung Self-Rating Anxiety Scale scores in the anxiety cohort. However, the difference between the anxiety group and the control group was statistically significant in the aforementioned parameters. The VAS, JOA, ODI and the SF-36 scores, and the disease duration were associated with pre-operative anxiety.

CONCLUSION

PTED may provide significant improvements in clinical outcomes and symptoms of anxiety. A negative impact on the patient's prognosis may be caused by the presence of anxiety. Pain severity, neurological deficit, disease duration, and quality of life were associated with anxiety.

Conventional versus computer-assisted surgery in total knee arthroplasty: comparison at ten years follow-up

PURPOSE

Computer-assisted systems (CAS) for total knee arthroplasty (TKA) were expected to result in more accurate prosthesis implantation, better patient outcomes, and longer implant survival when compared to conventional instrumentation (CI). The aim of this study was to compare two groups of patients operated using CAS or CI at ten years follow-up.

METHODS

One hundred twenty TKA patients, 60 using CAS and 60 using CI, were contacted after a decade for follow-up. Eligible patients received radiological examination to assess the lower-limb mechanical axis. They were also clinically assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Knee Society Score for Knee (KSS-K) and Function (KSS-F) Scoring. Kaplan-Meier survival analysis was performed to assess revisions, not for post-traumatic reasons.

RESULTS

In CAS and CI groups, the lower-limb mechanical axis was 1.7° ± 2.4° and 1.5° ± 2.8°, respectively; corresponding KOOS values were 82.3 ± 14.3 and 78.6 ± 14.4; KSS-K values were 85.9 ± 11.1 and 85.0 ± 9.7; KSS-F values were 82.2 ± 19.3 and 83.8 ± 18. For these assessments, the differences between the two groups were not statistically significant (p > 0.05). Two CAS (3.8%) and three CI patients (5.7%) were revised. The Kaplan-Meier analysis showed no significant differences between the two groups.

CONCLUSIONS

No significant differences were found at long-term follow-up in terms of radiographical-clinical outcomes and of implant survival between TKA operated using CAS or CI.