Survivorship and Clinical Outcomes of Primary Total Knee Arthroplasty Performed in Patients 35 Years of Age and Younger

Patterns of Meniscal Injuries in Adults Aged 35 and Older: A Retrospective Analysis of Surgical Cases

Background and Objectives: Knee joint injuries incur substantial healthcare and socioeconomic burdens worldwide. The connection between various demographic and clinical factors and meniscal injury patterns in patients undergoing surgery for meniscal rupture remains underexplored, especially in Eastern European cohorts. This study aimed to determine the influence of age, sex, and history of previous meniscal rupture on the patterns and types of knee joint injuries in adults aged 35 years and older undergoing surgery. Materials and Methods: A single-site exploratory retrospective analysis was conducted on 420 Romanian patients. The age of 35 years was selected as a cut-off for recruiting patients, as it marks the typical age at which early degenerative changes in the musculoskeletal system begin to emerge. Nonparametric/frequency analysis was applied to datasets stratified based on injury type-medial meniscal damage (MMD), lateral meniscal damage (LMD), and any patellar damage (APD). Logistic regression was used to determine influential predictors, including age, sex, and history of meniscal rupture. Results: Surgery was performed at a significantly younger age in patients with previous meniscus rupture (p < 0.001), but at a significantly older age in patients with co-occurring patellar lesions (p = 0.048). Men tended to be younger at the time of first surgery or any reoperations (p = 0.054) and displayed LMD significantly more often than MMD (p = 0.023). Significant differences existed in the distribution of different tear types in LMD (p < 0.001) and MMD (p < 0.001), with bucket handle tears and parrot beak tears being the most common. Male sex was associated with significantly higher odds of LMD (p = 0.046). Patients with previous meniscal rupture had a significantly and approximately threefold higher likelihood of presenting with MMD (p = 0.003). Conclusions: Age, sex, and history of meniscal rupture significantly influence the patterns and prevalence of knee injuries in adults aged 35 years and older. These findings reveal a dynamic interplay between demographic factors and knee joint pathologies, providing a foundation for targeted prevention and treatment strategies. Future studies should expand to larger, diverse populations to refine these insights.

Revision Total Knee Arthroplasty for Juvenile Idiopathic Arthritis: Implant Survivorship and Clinical Outcomes the Second Time Around

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a rare disease that oftentimes requires treatment with total knee arthroplasty (TKA). Although studies have examined the outcomes of primary TKA for this cohort, the literature on 10- and 20-year revision TKA implant survivorship and clinical outcomes is limited.

METHODS

A multicenter retrospective review identified 63 patients who underwent 70 revision TKAs between June 1, 1987, and September 30, 2020. The primary and secondary outcomes of interest were long-term implant survivorship and clinical outcomes, respectively. Patient-reported outcomes were assessed between April 1, 2020, and December 31, 2022. The average age was 47 years (range, 21 to 75). The mean follow-up was 12 years (range, 1.2 to 32.8) for both implant survivorship and patient-reported outcomes.

RESULTS

Implant survivorship for revision TKA in JIA patients was 86% (95% confidence interval (CI): 77 to 94) at 5 years, 75% (95% CI: 65 to 86) at 10 years, and 70% (95% CI: 59 to 81) at 20 years. The mean Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score was 72.8 ± 16.1 points, with 53% (18 of 34 patients, 21 of 38 TKAs) reaching the KOOS JR patient acceptable symptom state threshold. Risk factors for rerevision included the use of constrained prostheses (hazards ratio: 6.0, 95% CI [1.3 to 28.6], P = 0.025). The most common reasons for rerevision were implant loosening/instability (eight TKAs, 40%), pain/synovitis (eight TKAs, 40%), and infection (four TKAs, 20%).

CONCLUSIONS

Revision TKA implant survivorship for JIA patients is modest at 10 and 20 years after surgery. Patient-reported outcomes were similar to those previously reported for revision TKA. Rerevision risk increased with higher levels of constraint. Surgeons should be aware of these outcomes and risk factors when counseling and treating these patients the second time around.

LEVEL OF EVIDENCE

IV.

Drop in survivorship 13 years after AMIC procedures in aligned knees: A long-term follow-up

PURPOSE

Autologous matrix-induced chondrogenesis (AMIC) showed promising short-term results comparable to microfracture. This study aims to assess the 19-year outcomes of AMIC, addressing the lack of long-term data.

METHODS

Retrospective cohort of 34 knees treated with AMIC underwent a 19-year follow-up. The primary outcome was AMIC survival, considering total knee arthroplasty as a failure event. Survival analysis for factors that were associated with longer survival of the AMIC was also performed. Clinical and radiological outcome scores were analysed for the AMIC group.

RESULTS

Twenty-three knees were available for follow-up analysis. Of these, 14 (61%) underwent revision surgery for total knee arthroplasty (TKA). The mean time was 13.3 ± 2.5 years (range: 9-17 years). Secondary outcomes showed that increased age at surgery (hazard ratio [HR]: 1.05; p = 0.021) and larger defect size (HR: 1.95; p = 0.018) were risk factors for failure. Concomitant proximal tibial osteotomy (HR: 0.22; p = 0.019) was associated with longer survival. The remaining nine knees (39%) were analysed as a single group. The mean clinical score at follow-up of 18.6 ± 0.9 SD years was 79.5 ± 19.7 SD for the Lysholm score, 1.8 ± 1.5 SD for the visual analog scale score, 74.2 ± 22.4 SD for the KOOS score and a median of 3 (range: 3-4) for the Tegner activity scale.

CONCLUSIONS

The mean survival time of 13.3 years indicates the durability of AMIC in properly aligned knees. Nonetheless, despite a 61% conversion to TKA, the knees that persisted until the 19-year follow-up remained stable, underscoring the procedure's longevity and consistent clinical outcomes.

LEVEL OF EVIDENCE

Level IV.

Predictors of reoperation and survival experience for primary total knee arthroplasty in young patients with degenerative and inflammatory arthritis

INTRODUCTION

While total knee arthroplasty (TKA) is typically implemented in patients > 65 years old, young patients may need to undergo TKA for pain relief and functional improvement. Current data are limited by older cohorts and short-term survival rates. This study aimed to examine a large sample size of patients with degenerative and inflammatory conditions who underwent primary TKA at a young (≤ 40) age to identify predictors of reoperation, as well 15-year survivorship.

MATERIALS AND METHODS

A retrospective study was performed on 77 patients (92 surgeries) who underwent primary TKA at ≤ 40 years old, between January 1990 and January 2020. Patient charts were reviewed and a multivariable logistic regression model identified independent predictors of reoperation. Kaplan-Meier analysis was employed to build survival curves and log-rank tests analyzed survival between groups.

RESULTS

Of the 77 patients, the median age at the time of surgery was 35.7 years (IQR: 31.2-38.7) and median follow-up time was 6.88 years. Twenty-one (22.8%) primary TKAs underwent 24 reoperations, most commonly due to stiffness (n = 9, 32.1%) and infection (n = 13, 46.4%) more significantly in the OA group (p = 0.049). There were no independent predictors of reoperation in multivariable analysis, and 15-year revision-free survivorship after TKA did not differ by indication (77.3% for OA/PTOA vs. 96.7% for autoimmune, p = 0.09) or between ≤ 30 and 31-40 year age groups (94.7% vs. 83.6%, p = 0.55).

CONCLUSIONS

In this cohort of patients ≤ 40 years old, revision-free survival was comparable to that reported in the literature for older TKA patients with osteoarthritis/autoimmune conditions (81-94% at 15-years). Though nearly a quarter of TKAs required reoperation and causes of secondary surgery differed between degenerative and inflammatory arthritis patients, there were no significant predictors of increased reoperation rate. Very young patients ≤ 30 years old did not have an increased risk of revision compared to those aged 31-40 years.

Robotic-assisted total knee arthroplasty is associated with the use of thinner polyethylene liners compared to navigation-guided and manual techniques

PURPOSE

The purpose of this study was to examine the effects of intraoperative technology use on the rate of using polyethylene liners 15 mm or greater during primary total knee arthroplasty (TKA).

METHODS

There were 103,295 implants from 16,386 primary unilateral TKAs performed on 14,253 patients at a single institution between 1 January 2018, and 30 June 2022, included in the current study. Robotic assistance and navigation guidance were used in 1274 (8%) and 8345 (51%) procedures, respectively. The remaining 6767 TKAs (41%) were performed manually. Polyethylene liners were manually identified and further subcategorised by implant thickness. Patients who underwent robotic-assisted TKA were younger (p < 0.001) and more likely to be male (p < 0.001) compared to patients who underwent navigation-guided or manual TKAs.

RESULTS

Average polyethylene liner thickness was similar between groups (10.5 ± 1.5 mm for robotic-assisted TKAs, 10.9 ± 1.8 mm for navigation-guided TKAs and 10.8 ± 1.8 mm for manual TKAs). The proportions of polyethylene liners 15 mm or greater used were 4.9%, 3.8% and 1.9% for navigation-guided, manual and robotic-assisted procedures, respectively (p < 0.001). Multivariate regression analyses demonstrated that navigation-guided (odds ratio [OR]: 2.6, 95% confidence Interval [CI]: [1.75-4.07], p < 0.001) and manual (OR: 2.0, 95% CI: [1.34-3.20], p = 0.001) procedures were associated with an increased use of polyethylene liners 15 mm or greater.

CONCLUSION

Robotic-assisted TKA was associated with a lower proportion of polyethylene liners 15 mm or greater used compared to navigation-guided and manual TKA. These findings suggest that robotic assistance can reduce human error via a more precise cutting system, limit over-resection of the tibia and flexion-extension gap mismatch and ultimately allow for more appropriately sized implants.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

High and Low Dosage of Vancomycin in Polymethylmethacrylate Cements: Efficacy and Mechanical Properties

INTRODUCTION

Prosthetic joint infections (PJIs) are difficult to treat and represent a significant burden to the healthcare system. Two-stage revision surgery with placement of an antibiotic-loaded cement spacer is currently the gold standard for treatment in the United States for late-onset infections. We evaluate the efficacy of varying doses of vancomycin added to antibiotic-containing acrylic cement spacers and discuss the biomechanical and antimicrobial properties of using high versus low doses of vancomycin in cement spacers in the hip and knee.

MATERIALS AND METHODS

Commercially available Copal cement containing either gentamicin and clindamycin (G + C) or gentamicin and vancomycin (G + V) was prepared with the manual addition of low (2 g) and high (6 g) doses of vancomycin. In vitro mechanical testing was then carried out according to ISO 5833 and DIN 53435, as well as inhibition zone assays against common PJI pathogens. Additionally, inhibition zone assays were conducted on two commercially available prefabricated spacers containing gentamicin: Copal Exchange G and Cemex Spacer-K.

RESULTS

In biomechanical testing, Copal G + V with the addition of 6 g of vancomycin failed to meet the ISO standard. Copal G + C and Copal G + V with low and high dosages of vancomycin were all effective against the tested pathogens and displayed constant efficacy for a duration of 42 days. High doses of vancomycin showed significantly lower mechanical stability. Moreover, Copal Exchange G showed significantly larger inhibition zones across 42 days.

DISCUSSION

While higher concentrations of vancomycin appear to improve the antimicrobial efficacy of cement, they also reduce its mechanical stability. Despite its smoother surface, the Copal Exchange G spacer exhibits large inhibition zones after 1 day and maintains consistently large inhibition zones over 6 weeks. Thus, it may be preferred for use in two-stage revision surgery.

CONCLUSION

Copal Exchange G is more effective than Cemex Spacer K against S. aureus and E. coli. The manual addition of vancomycin to cement containing double antibiotics is very effective. The influence on ISO compression is low, the ISO bending modulus is increased, and ISO bending, DIN bending, and DIN impact, are reduced.