Proximal fibular partial excision delays medial joint space narrowing of the medial tibiofemoral joint.

backgroundProximal fibular partial excision (PFPE) is a novel treatment for medial compartment knee osteoarthritis (KOA), but its benefits, especially radiological benefits, are still controversial. This retrospective cohort study aims to investigate the osteoarthritic progression in medial tibiofemoral congruence and joint space width (JSW) following PFPE.

methodsThe patients with medial compartment KOA who accepted PFPE or nonsurgical treatment were retrospectively enrolled. Preoperative/baseline, postoperative, and 5-years follow-up X-ray radiographs were collected. A novel self-designed curve-fitting algorithm was created and the medial tibiofemoral congruence and JSW were calculated and compiled semi-automatically. A total of 77 patients were initially enrolled in this study, and those who completed follow-up after PFPE were selected for 1:1 propensity score matching (PSM) with control patients. Variables adjusted in PSM included preoperative/baseline age, gender, BMI, side, medial tibiofemoral congruence, and JSW (including mean, maximum, and minimum values), resulting in 30 patients in each group. Comparisons between the PFPE group and control group were performed both before and after PSM.

resultsA total of 77 PFPE knees and 112 control knees were identified from a comprehensive 5-years retrospective study. In the PFPE knees, the postoperative mean and minimum JSW significantly increased compared with the preoperative values (mean: 4.634 vs. 4.457, p = 0.031; minimum: 4.012 vs. 3.836, p = 0.031, respectively). Thirty-three PFPE knees completed a 5-years follow-up, and no statistical difference in the congruence and JSW was observed between preoperative and follow-up outcomes (all p > 0.05). In the 112 control knees, the JSW significantly decreased at the 5-years follow-up compared to the baseline conditions (all p < 0.01). After PSM, 30 knees in each group were selected, and significantly higher JSW was observed in the PFPE group at the 5-years follow-up (mean: 4.350 vs. 3.650, p = 0.007; maximum: 5.740 vs. 5.095, p = 0.046; minimum: 3.739 vs. 2.963, p = 0.003, respectively).

conclusionsPFPE delays the medial joint space narrowing of the medial tibiofemoral joint at a 5-years follow-up, providing new evidence for the long-term radiological benefits of PFPE. Future prospective and large sample studies are still needed to objectively evaluate the advantages and disadvantages of PFPE. LEVEL OF EVIDENCE: Level III, therapeutic study.