Bilateral fibular osteotomy shows seven-year symptom relief in knee osteoarthritis cohort

A single-centre retrospective cohort study reports that simultaneous bilateral proximal fibular osteotomy (SBPFO), a surgical procedure for patients with bilateral medial compartment knee osteoarthritis, was associated with sustained pain relief and functional improvement over a mean follow-up of roughly seven years. The study, published in BMC Surgery, followed 59 patients operated on between 2018 and 2020 and found that 55 retained both native knees at final follow-up, with only one knee converted to total knee arthroplasty during the observation period.

Their mean follow-up was 7.03 ± 0.57 years, with a range of 6.0 to 8.5 years.

On the safety side, the results were favourable. Primary wound healing was achieved in all 59 treated patients, and one patient experienced transient toe numbness that resolved spontaneously within three months. Only one patient required unilateral conversion to total knee arthroplasty, at 58 months after the index operation, and this was counted as a treatment failure. Kaplan–Meier survivorship free from any conversion to knee arthroplasty was 98.3 percent (95 percent confidence interval, 88.6 to 99.8 percent) at seven years at the patient level.

Radiographic measurements showed modest but statistically significant improvements in lower-limb alignment. The hip–knee–ankle angle increased from 175.97 ± 0.80 degrees to 177.20 ± 1.26 degrees, moving closer to neutral alignment, while the femorotibial angle decreased from 177.68 ± 1.61 degrees to 175.98 ± 2.02 degrees. The joint line convergence angle fell from 5.31 ± 0.81 degrees to 4.10 ± 1.07 degrees, and the settlement value, a measure of medial plateau depression, decreased from 5.27 ± 1.19 mm to 4.41 ± 1.35 mm, all with P < 0.001. Notably, the weight-bearing line ratio did not change significantly after Bonferroni correction, indicating that the overall coronal load axis was not substantially shifted.

Small changes were observed in ankle-related parameters: the talar tilt angle decreased from 5.55 ± 1.06 degrees to 4.72 ± 1.49 degrees and tibial plafond inclination decreased from 6.17 ± 0.80 degrees to 5.54 ± 1.16 degrees, both P < 0.001. Fibular height increased from 19.02 ± 1.37 mm to 23.72 ± 2.27 mm, consistent with distal migration of the fibular head, and lateral plateau widening decreased from 5.13 ± 0.44 mm to 3.93 ± 0.85 mm. No significant changes were detected in patellofemoral or hip-joint parameters, including the posterior tibial slope, tibial tubercle prominence, Blackburne–Peel and Caton–Deschamps indices, hip abduction angle, acetabular index, or Sharp angle.

Clinical outcome scores improved substantially. The Visual Analogue Scale pain score fell from 6.36 ± 0.60 to 3.88 ± 0.92, the Western Ontario and McMaster Universities Osteoarthritis Index dropped from 63.55 ± 4.40 to 37.89 ± 7.88, and the Hospital for Special Surgery knee score rose from 43.40 ± 7.41 to 65.06 ± 7.91, all with P < 0.001. Range of motion did not change significantly. The authors note that despite these gains, residual symptoms persisted.

The conclusion drawn by the research team is carefully bounded. In this single-arm cohort with a mean follow-up of approximately seven years, SBPFO was associated with symptom relief and functional improvement in carefully selected patients with bilateral medial compartment knee osteoarthritis who retained their native knees through final follow-up. The radiographic analysis showed modest improvements in lower-limb alignment, small changes in ankle-related parameters, distal migration of the fibular head, and reduced lateral plateau widening. The authors explicitly state that controlled studies are needed to confirm these findings.

That caveat matters for interpretation. The survivorship estimate, while high, carries a wide confidence interval reflecting the small cohort size. For patients and clinicians, the study offers mid-term evidence that the procedure can be performed with low complication rates and durable symptom improvement in selected individuals, but it does not establish superiority over non-operative management or over established realignment procedures such as high tibial osteotomy.

Subject of Research: Mid-term clinical and radiographic outcomes of simultaneous bilateral proximal fibular osteotomy for bilateral medial compartment knee osteoarthritis

Article Title: Assessment of mid-term clinical outcomes and radiographic analysis of simultaneous bilateral proximal fibular osteotomy for bilateral medial compartment Knee osteoarthritis: a single-arm retrospective cohort study with 7-year follow-up

Article References: Jiang, Y., Cui, D., Li, H., Wang, W., Zhang, L., Wang, T., Zhao, X., Zhang, Y., Yu, N., Chen, J., & Xu, K. (2026). Assessment of mid-term clinical outcomes and radiographic analysis of simultaneous bilateral proximal fibular osteotomy for bilateral medial compartment Knee osteoarthritis: a single-arm retrospective cohort study with 7-year follow-up. BMC Surgery. https://doi.org/10.1186/s12893-026-04302-3

Image Credits: AI Generated

DOI: 10.1186/s12893-026-04302-3

Keywords: knee osteoarthritis, proximal fibular osteotomy, medial compartment, retrospective cohort study, lower-limb alignment, radiographic outcomes, joint preservation, survivorship analysis, BMC Surgery, orthopaedic surgery, varus deformity, seven-year follow-up