Department of Orthopaedics, Dr. Sampurnanand Medical College, Jodhpur, Rajasthan, India.
Department of Orthopaedics, Choudhary Bhupendra Hospital, Bhinmal, Rajasthan, Jalore, India.
Int Orthop. 2022 Jul;46(7):1501-1506. doi: 10.1007/s00264-022-05364-7. Epub 2022 Mar 15.
To analyze the effect of implant position measured in terms of offset on patient reported outcomes (PRO) following hip arthroplasty (THA).
A total of 243 patients of the total hip replacement who had a one year follow-up were included in the study. Standard both hips radiograph was used to asses post-surgery implant position in terms of horizontal offset and vertical offset, and correlated with functional outcome which was evaluated as change in PRO. i.e., Harris hip score (HHS) post-op. With center of hip rotation as reference, horizontal offset was calculated as sum of distance, of centre, from proximal femoral shaft axis and a vertical line through ipsilateral teardrop, and vertical offset as limb length discrepancy. Post-op patients were classified into three groups depending on the measurement of horizontal offset of the operated hip. The patients having operated hip horizontal offset within 5 mm of the normal hip were grouped as restored offset (RO); those having shorter or higher offset by more than 5 mm compared to normal hip were labeled as decreased (DO) or increased offset (IO) group respectively. The groups were further subdivided into suboptimal and optimal function groups based on HHS, and among these groups, limb length discrepancy was evaluated.
Post follow-up mean HHS (78.23 ± 9.96) improved significantly in all three groups (p < 0.0001). The difference in post-operative HHS among DO, RO, and IO groups was significant, with their averages being 72.5 ± 4.7, 82.1 ± 6.5, and 75.2 ± 4.8 respectively (p = .01). Limb length discrepancy was significantly more common in patients with suboptimal functional scores in all three groups.
This study concluded that both horizontal offset and vertical offset should be reconstructed in patients operated with unilateral THR due to hip pathology, since both factor demonstrated a comparable additive effect on clinical outcome.
分析髋关节置换术后以偏移量衡量的种植体位置对患者报告结局（PRO）的影响。
本研究共纳入 243 例接受全髋关节置换术且随访 1 年的患者。采用标准双侧髋关节正位片评估术后种植体位置的水平偏移和垂直偏移，并与功能结局相关联，即术后 PRO 变化，即 Harris 髋关节评分（HHS）。以髋关节旋转中心为参照，水平偏移量计算为股骨近端干骺端轴线与同侧泪滴的垂直线之间距离的总和，垂直偏移量为肢体长度差异。术后患者根据手术侧髋关节水平偏移量的测量值分为三组。将手术侧髋关节水平偏移量与正常髋关节相差 5mm 的患者归入恢复偏移量（RO）组；与正常髋关节相比，水平偏移量较小或较大超过 5mm 的患者分别归入减少（DO）或增加（IO）偏移量组。这些组根据 HHS 进一步分为功能不佳和功能良好组，并在这些组中评估肢体长度差异。
所有三组患者在随访后平均 HHS（78.23±9.96）均显著提高（p<0.0001）。DO、RO 和 IO 组之间术后 HHS 的差异具有统计学意义，其平均值分别为 72.5±4.7、82.1±6.5 和 75.2±4.8（p=0.01）。在所有三组中，功能评分不佳的患者肢体长度差异更为常见。
本研究表明，由于髋关节病变，单侧 THR 术后应重建水平和垂直偏移量，因为这两个因素对临床结局均有类似的附加影响。
