Outcomes After Meniscal Root Repair in Patients With and Without Advanced Patellofemoral Chondromalacia: Comparison at 2-Year Follow-up

Background

Meniscal root repair can improve patient outcomes significantly; however, several contraindications exist, including arthritic change to the medial or lateral tibiofemoral compartments.

Purpose/Hypothesis

The purpose of this study was to evaluate the outcomes of meniscal root repair in patients with advanced patellofemoral chondromalacia (PFC). It was hypothesized that the presence of advanced PFC would not significantly affect the postoperative outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective review was conducted of patients who underwent meniscal root repair with at least 2 years of follow-up data. Patients with chondromalacia as determined by arthroscopic visualization (defined as Outerbridge grade 3 or 4) were placed in the PFC group; patients with Outerbridge grade 0 to 2 chondromalacia were placed in the non-PFC group. Outcomes were measured by the Lysholm knee scoring scale and the International Knee Documentation Committee (IKDC) Subjective Knee Form. Clinical outcomes including complications were also recorded. Quantitative data between the groups were analyzed using the 2-tailed independent-samples t test.

Results

Overall, this study included 81 patients (35 in the PFC group, 46 in the non-PFC group). The mean follow-up times were 25.1 months in the PFC group and 24.8 months in the non-PFC group. In both groups, Lysholm and IKDC scores improved significantly with 24-month Lysholm scores averaging 85.86 in the PFC group and 86.61 in the non-PFC group (P = .62) and 24-month IKDC scores averaging 77.66 for the PFC group and 79.59 for the non-PFC group (P = .45). The cohorts demonstrated similar rates of retear, arthrofibrosis, infection, and progression to total knee arthroplasty.

Conclusion

The presence of advanced PFC was not associated with inferior outcomes in patients who underwent posterior meniscal root repair, and rates of recurrent tears, postoperative infection, arthrofibrosis, and conversion to total knee arthroplasty were similar between the study groups. These findings suggest that PFC may not significantly alter the results of meniscal root repair and should not be considered an absolute contraindication for this procedure.

Preoperative Patellofemoral Chondromalacia is Not a Contraindication for Fixed-Bearing Medial Unicompartmental Knee Arthroplasty

BACKGROUND

Patellofemoral chondromalacia (PFCM) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA), but there is limited data assessing PFCM's impact on the results of fixed-bearing UKA. Our objective was to assess the impact of medial patellar and/or medial trochlear PFCM on overall and patellofemoral-specific 2-year outcomes after fixed-bearing medial UKA.

METHODS

Intraoperative notes defined the presence and location of PFCM during fixed bearing medial UKA. Outcome measures included the New Knee Society Score (NKSS), Kneeling Ability Score (KAS) and Forgotten Joint Score (FJS-12). Thirty-one knees with PFCM (PFCM group), and 52 knees without PFCM (N-PFCM group) were included for analysis. Mann-Whitney U tests assessed the statistical significance of observed differences, and a Bonferroni correction was applied, adjusting threshold for significance to P = .005.

RESULTS

At minimum follow-up of 2 years, no statistical differences were detected between the N-PFCM and PFCM groups in the postoperative NKSS (159 vs 157, P = .731), preoperative to postoperative NKSS change (P = .447), FJS-12 (70.5 vs 67.6, P = .471), or KAS (71% vs 65%, P = .217). Patients with isolated patellar chondromalacia (n = 13) demonstrated trends toward worse outcomes according to NKSS (147, P = .198), FJS-12 (58, P = .094), and KAS (46%, P = .018), but were statistically insignificant. No failures occurred in either group.

CONCLUSION

Functional outcomes of fixed-bearing medial UKA are not adversely impacted by the presence of PFCM involving the medial patellar facet and/or medial or central trochlea. Further follow-up is needed to determine longer-term implications of fixed-bearing medial UKA in patients with PFCM.