Da Cunha Rachael J, Kraszewski Andrew P, Hillstrom Howard J, Fragomen Austin T, Rozbruch S Robert
1Limb Lengthening and Complex Reconstruction Service, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
2Kingston Health Sciences Centre, Division of Orthopaedic Surgery, Department of Surgery, Queen's University, 76 Stuart Street, Kingston, ON K7L 2V7 Canada.
HSS J. 2020 Feb;16(1):30-38. doi: 10.1007/s11420-019-09670-6. Epub 2019 Mar 19.
Mechanical axis malalignment contributes to abnormal forces across the knee joint. Genu varum, or increased medial mechanical axis deviation (MAD), increases force transmission and contact pressures to the medial compartment. With increasing MAD and femoral-tibial mechanical axis angle (MAA), contact forces within the medial or lateral compartment of the knee significantly increase with increasing deformity. This may lead to knee pain, further deformity, and medial compartment degenerative joint disease, which can interfere with participation in sports and diminish quality of life.
PURPOSES/QUESTIONS: We sought to evaluate patients with knee pain with bilateral genu varum and determine the effect of bilateral proximal tibial osteotomies on knee biomechanics, deformity correction, and functional outcomes.
This was a single-center, prospective study of eight limbs in four patients. Consecutive patients presenting with knee pain and bilateral genu varum originating from the proximal tibia were included. All patients underwent staged bilateral proximal tibial osteotomies with gradual deformity correction with an external fixator. Subjects underwent a three-dimensional (3D) instrumented motion analysis during level walking. A 3D lower extremity model was built and bilateral knee frontal plane kinematics and kinetics during the stance phase of gait were determined. Radiographic analysis was performed including assessment of MAD, MAA, and medial proximal tibial angle (MPTA). Functional outcomes were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS), the 36-item Short-Form Survey (SF-36), the Lower Limb Questionnaire (LLQ), and a visual analog scale (VAS) for pain.
The average time in the external fixator for a single limb was 97 days. The average follow-up period was 310 days. All biomechanical outcomes significantly improved, including knee adduction angle (7.8° to 1.8°), knee adduction moments (first peak, - 0.450 to - 0.281 nm/kg, and second peak, - 0.381 to - 0.244 nm/kg), and knee adduction moment impulse (- 0.233 to - 0.150 nm s/kg). There was a significant improvement in MAA, MAD, and MPTA. All patients showed qualitative improvement in mean scores on VAS (11.8 to 0.0), LLQ (77 to 93), KOOS (64 to 84), and SF-36 (71 to 88).
These findings suggest that bilateral proximal tibial osteotomy may be effective in improving knee biomechanics during gait and correcting mechanical alignment in patients with bilateral genu varum. Patients also demonstrated improvement in functional outcome scores. This technique should thus be considered in patients with varus knee osteoarthritis in the setting of genu varum to alleviate symptoms and potentially decrease further clinical deterioration.
机械轴对线不良会导致膝关节受力异常。膝内翻，即内侧机械轴偏差（MAD）增加，会增加内侧间室的力传递和接触压力。随着MAD和股胫机械轴角（MAA）的增加，膝关节内侧或外侧间室的接触力会随着畸形程度的增加而显著增加。这可能导致膝关节疼痛、进一步畸形以及内侧间室退行性关节病，进而影响参与体育运动并降低生活质量。
目的/问题：我们旨在评估双侧膝内翻的膝关节疼痛患者，并确定双侧胫骨近端截骨术对膝关节生物力学、畸形矫正及功能结局的影响。
这是一项针对4例患者8个肢体的单中心前瞻性研究。纳入因胫骨近端病变导致膝关节疼痛和双侧膝内翻的连续患者。所有患者均接受分期双侧胫骨近端截骨术，并使用外固定器逐步矫正畸形。受试者在平地上行走时接受三维（3D）仪器化运动分析。构建3D下肢模型，并确定步态站立期双侧膝关节额面运动学和动力学。进行影像学分析，包括评估MAD、MAA和胫骨近端内侧角（MPTA）。使用膝关节损伤和骨关节炎结局评分（KOOS）、36项简明健康调查问卷（SF-36）、下肢问卷（LLQ）以及疼痛视觉模拟量表（VAS）评估功能结局。
单肢在外固定器中的平均时间为97天。平均随访期为310天。所有生物力学指标均显著改善，包括膝关节内收角（从7.8°降至1.8°）、膝关节内收力矩（第一个峰值，从 - 0.450降至 - 0.281nm/kg，第二个峰值，从 - 0.38l降至 - 0.244nm/kg）以及膝关节内收力矩冲量（从 - 0.233降至 - 0.150nm·s/kg）。MAA、MAD和MPTA均有显著改善。所有患者的VAS平均评分（从11.8降至0.0）、LLQ（从77升至93）、KOOS（从64升至84）和SF-36（从71升至88）均有定性改善。
这些发现表明，双侧胫骨近端截骨术可能有效改善步态期间的膝关节生物力学，并矫正双侧膝内翻患者的机械对线。患者的功能结局评分也有所改善。因此，对于伴有膝内翻的膝内翻骨关节炎患者，应考虑采用该技术来缓解症状并可能减少进一步的临床恶化。
