The effect of gender, age, BMI and Kellgren-Lawrence grade on functional outcome after Physica ZUK medial unicompartmental knee replacement

Are relative contraindications for unicompartmental knee replacements in medial compartment osteoarthritis really contraindications?

Background

Medial unicompartment knee replacement (UKR) is performed for isolated medial compartment osteoarthritis. Understanding the factors influencing functional outcomes helps patient selection and outcomes. We will review the association between pre-operative BMI and patellofemoral articular wear on post operative Oxford Knee Scores at >2 and > 5 years.

Methods

A retrospective review of a prospectively collected database was performed. Inclusion criteria were medial UKR for medial compartment OA. The exclusion criteria were age <16, revision procedures and lateral UKR's. Data was collected between 26/6/2014 and 25/8/2022. Statistical analysis was performed using SPSS. Significance was given to variables that reached p < 0.05.

Results

159 UKR procedures were identified in 155 patients. 116 procedures carried out on 111 patients had follow up at > 2 years. At 5 years there were 14 patients had OKS recorded. There was no statistical difference in the ICRS grade I&II vs III&IV groups for >2 year or >5 year OKS with p = 0.408 and p = 0.876. For BMI there was a moderately negative correlation on spearman's rank p(df) = -0.339 (CI 95 % -0.538, -0.104) at >2 years, which was statistically significant with p = 0.004. >5 year data didn't reach significance with p = 0.828.

Conclusion

BMI maybe an important patient factor in predicting post operative OKS at 2-5 years. This is beneficial to surgeons for patient selection in medial UKR. Patellofemoral wear doesn't appear to impact on post operative functional outcomes. This supports the theory that patient who suffer from patellofemoral wear, as well as medial compartment wear can benefit from UKR, expanding the current indications.

Autologous microfragmented adipose tissue and leukocyte-poor platelet-rich plasma combined with hyaluronic acid show comparable clinical outcomes for symptomatic early knee osteoarthritis over a two-year follow-up period: a prospective randomized clinical trial

PURPOSE

The purpose of this prospective randomized clinical trial is to compare the clinical outcomes of three injections of leucocyte-poor platelet-rich plasma (LP-PRP) and hyaluronic acid (HA) to a single dose of autologous microfragmented adipose tissue (AMAT) in patients with mild osteoarthritis at a two-year follow-up.

METHODS

Eighty symptomatic knees in fifty patients (mean age: 62.38 ± 11.88 years) with Kellgren-Lawrence grade 0 to 2 osteoarthritis were non blinded, randomly allocated into two equal groups. Group 1 consisted of 40 knees that received autologous LP-PRP + HA; Group 2 consisted of 40 knees treated with a single dose of AMAT injection. The outcomes were measured by Tegner, Marx, Visual Analogue Scale (VAS) for pain, International Knee Documentation Committee, and Knee Injury and Osteoarthritis Outcome Score (KOOS) at 6 (T1), 12 (T2), and 24 (T3) months. Adverse events were recorded at each follow-up timepoint. To assess score differences among subjects of the same gender and age, a subgroup analysis was performed.

RESULTS

Both groups had significant clinical and functional improvement at 6, 12, and 24 months (p < 0.05). Comparing the two groups, the AMAT groups showed significantly higher pre-operative Marx score (3.35 ± 4.91 vs. 1.78 ± 3.91) and VAS score (5.03 ± 2.02 vs. 3.85 ± 1.68) (p < 0.05), higher VAS (3.89 ± 2.51 vs. 2.64 ± 2.00) at T2 and KOOS-ADL (79.60 ± 20.20 vs. 65.68 ± 23.62), and lower KOOS-Sports (50.30 ± 30.15 vs. 68.35 ± 30.39) at T3 (p < 0.05). No patient from either group had experienced major adverse effects. In the LP-PRP group 12 (30%) patients presented swelling, redness, and mild pain for one day after injection and two patients had synovitis for two days and required paracetamol and local ice. In AMAT group 5 (12.5%) patients had ecchymosis and bruising at the fat aspiration site for three days.

CONCLUSION

AMAT did not show significant superior clinical improvement compared with three LP-PRP combined with HA injections in terms of functional improvement at different follow-up points. Both procedures were safe with no major complications reporting good results at mid-term follow-up, improving knee function, pain, and quality of live regardless of age and gender.

LEVEL OF EVIDENCE

Level I-Prospective Randomized Clinical Trial.