Shetty Ajoy Prasad, Suresh Subramani, Aiyer Siddharth N, Kanna Rishi, Rajasekaran Shanmuganathan
Department of Spine Surgery, Ganga Hospital, Coimbatore, India.
J Spine Surg. 2017 Dec;3(4):541-547. doi: 10.21037/jss.2017.09.04.
Lenke 5 C curves are frequently associated with clinically and radiological coronal imbalance. Appropriate selection of proximal and distal levels of fusion is essential to ensure good coronal balance (CB). We aimed to evaluate radiological factors associated with (I) global CB in the early post-operative period; (II) late decompensation of CB; and (III) favourable spontaneous correction of CB on long term follow up.
Twenty-three Lenke type 5C scoliosis cases treated with selective posterior lumbar instrumentation were retrospectively evaluated. Pre-operative, early post-operative and late post-operative (>2 years) whole length radiographs were analysed. Cobb's angle, lumbar lordosis, coronal imbalance, lower instrumented vertebra (LIV) tilt and translation and upper instrumented vertebra (UIV) tilt and translation were measured. The proximal and distal fusion levels were noted and correlated with post-operative CB.
There were 21 females and 2 males with a mean follow up of 36 months. The mean pre-operative cobb angle was 55°±13.26°, which corrected to 14.7°±8.84° and was maintained on follow up. Eight patients had early post-operative coronal imbalance with spontaneous resolution seen in six cases on long term follow-up. At final follow-up, four cases had coronal imbalance (persistent imbalance since early post-operative period =2; late decompensation =2). In cases with early imbalance 5/8 cases had a pre-operative LIV tilt of ≥25°. All four patients with coronal imbalance at final follow-up had pre-operative LIV tilt ≥25°. Radiographic parameters which correlated with post-operative coronal imbalance were pre-operative LIV tilt (r=0.64, P=0.001), pre-operative LIV translation (r=0.696, P<0.001), pre-operative UIV translation (r=0.44, P=0.030), post-operative LIV tilt (r=0.804, P<0.001), and post-operative UIV tilt (r=0.62, P=0.001).
In Lenke 5C scoliosis, a pre-operative LIV tilt ≥25° significantly correlates with post-operative global coronal imbalance. Increasing UIV tilt may be a factor that accounts for improvement of CB in late follow-up period.
Lenke 5 C型曲线常与临床及影像学冠状面失衡相关。恰当选择近端和远端融合节段对于确保良好的冠状面平衡（CB）至关重要。我们旨在评估与以下方面相关的影像学因素：（I）术后早期的整体CB；（II）CB的晚期失代偿；（III）长期随访中CB的良好自发矫正。
对23例接受选择性后路腰椎内固定治疗的Lenke 5C型脊柱侧弯病例进行回顾性评估。分析术前、术后早期及术后晚期（>2年）的全长X线片。测量Cobb角、腰椎前凸、冠状面失衡、下位固定椎（LIV）倾斜度及平移、上位固定椎（UIV）倾斜度及平移。记录近端和远端融合节段，并与术后CB进行相关性分析。
共21例女性和2例男性，平均随访36个月。术前平均Cobb角为55°±13.26°，术后矫正至14.7°±8.84°，并在随访中维持。8例患者术后早期出现冠状面失衡，6例在长期随访中自发缓解。末次随访时，4例存在冠状面失衡（术后早期持续失衡=2例；晚期失代偿=2例）。早期失衡的病例中，5/8例术前LIV倾斜度≥25°。末次随访时所有4例冠状面失衡患者术前LIV倾斜度均≥25°。与术后冠状面失衡相关的影像学参数有术前LIV倾斜度（r=0.64，P=0.001）、术前LIV平移（r=0.696，P<0.001）、术前UIV平移（r=0.44，P=0.030）、术后LIV倾斜度（r=0.804，P<0.001）及术后UIV倾斜度（r=0.62，P=0.001）。
在Lenke 5C型脊柱侧弯中，术前LIV倾斜度≥25°与术后整体冠状面失衡显著相关。UIV倾斜度增加可能是晚期随访中CB改善的一个因素。
