Summary

Femoral and tibial derotation osteotomies are effective interventions in management of relevant hip and knee symptoms resulting from rotational deformities.

Abstract

Introduction.
Rotational profile of femur and tibia significantly contribute to the kinematics of hip and knee joints. Femoral version abnormalities lead to impingement syndromes, hip articular damage and periarticular muscle imbalance, gait disturbances, as well as dysfunction of patello-femoral joint (PFJ). Although the role of tibial torsion derangements in PFJ dysfunction is evident, their contribution to hip symptoms, especially with certain activities, is less well understood. The treatment of femoral and tibial rotational deformities includes Proximal Femoral Derotation Osteotomy (PFDO) and Distal Tibial Derotation Osteotomy (DTDO), respectively. We aimed to determine the clinical effectiveness of these interventions in improving patients’ hip and knee symptoms.

Materials.
We performed a retrospective review of prospectively collected data in patients that underwent PFDO and DTDO between 2018-2020. PFDO was routinely stabilised using intramedullary nail (Metatan, S&N) and DTDO with tibial plate (EVOS, S&N). Pre-operative and interval post-operative functional outcomes were analysed and correlated. Functional outcomes included international hip outcome tool (iHOT12), hip and knee outcome score activities of daily living scale (HOS ADLS and KOS ADLS, respectively) and sport scale (HOS SS and KOS SS, respectively), non-arthritic hip score (NAHS) and anterior knee pain or Kujala score (AKP). HOS and KOS scores included additional graphical scores.

Results.
We identified 22 patients that underwent PFDO (13 females) and 30 – DTDO (27 females). Average age was 24 years (17-38) and 26 years (18-44) in PFDO and DTDO cohorts, respectively. Average follow-up was 18 months (2-35). Statistical difference between pre-operative and post-operative scores was achieved at 18 and 12 months for PFDO and DTDO, respectively.
To date, there were two non-unions in PFDO group, one treated with Exogen ultrasound device and one with exchange nailing. Three further PFDO required nail dynamization. There were no other significant post-operative complications.
Pre-operative vs 18 months post-operative scores for PFDO were 33 vs 88 for iHOT 12; 55 vs 91 for HOS ADLS and 46 vs 92 for HOS ADLS graphical; 44 vs 86 for HOS SS and 39 vs 80 for HOS SS graphical; and 57 vs 89 for NAHS. Pre-operative vs 12 months post-operative scores for DTDO were 38 vs 97 for iHOT 12; 58 vs 94 for KOS ADLS and 61 vs 95 for KOS ADLS graphical; 52 vs 96 for KOS SS and 40 vs 96 for KOS SS graphical; and 58 vs 94 for AKP.

Conclusions.
Femoral and tibial rotational deformities are important to be recognised as contributing factors to hip and knee pain. Derotation osteotomies are effective interventions in management of relevant symptoms resulting from rotational deformities. Recovery is more rapid following tibial osteotomy, although the initial level of pre-operative function is higher in patients with tibial torsional abnormalities. Nevertheless, both osteotomies can lead to a functional recovery to near normal level at the maximum of 18 months.