Complications Associated With Epiphysiodesis for Management of Leg Length Discrepancy.

BACKGROUND: Epiphysiodesis is well-established surgical treatment for the management of leg length discrepancy (LLD) in children; however, a variety of complications may occur. This study evaluates the nature, rate, and potential risk factors of complications associated with epiphysiodesis in a large patient population treated in 1 institution. METHODS: We evaluated the medical and radiographic records of 863 children who had lower extremity epiphysiodesis to manage LLD between 1980 and 2011. RESULTS: Sixty patients (7.0%) incurred complications of some type. Twenty-three patients (2.7%) had perioperative complications unrelated to physeal growth; all resolved without surgical treatment. These included 2 patients with transient intraoperative complications (laryngospasm and allergic rash), 7 with transient neurological symptoms (5 cutaneous nerve dysesthesia or numbness and 2 peroneal nerve neuropathies), and 14 with postoperative knee stiffness which resolved with therapy. Thirty-seven patients (4.3%) developed physeal growth-related complications, including 6 patients who developed overcorrection of leg length inequality (3 had contralateral epiphysiodesis to prevent overcorrection, while 3 declined), and 31 patients who developed angular deformity and/or continued growth of the physis. Of these 31 patients, 15 had reexploration of the epiphysiodesis site, 6 underwent corrective osteotomy, while in 10, no treatment was undertaken. Compared with patients who did not develop angular deformity, these 31 patients had significantly greater LLD (5.6 vs. 3.7 cm, respectively, P<0.01), were younger (10.7 vs. 11.7 in girls; 12.4 vs. 13.5 in boys; P<0.01), and were more likely to have a congenital etiology for their LLD (P<0.01). CONCLUSIONS: Epiphysiodesis is a safe and effective procedure for the correction of leg length inequality. The rate of complications in this study was 7.0%, the most prevalent being the development of angular deformity. Congenital etiology, younger age, and larger limb length inequalities were risk factors for the development of angular deformity. Both surgeons and families should be aware of nature and rate of complications associated with epiphysiodesis. LEVEL OF EVIDENCE: Level IV.

Three-dimensional True Spine Length: A Novel Technique for Assessing the Outcomes of Scoliosis Surgery.

BACKGROUND: Current assessment of spine growth for patients undergoing growth friendly surgical treatment for early-onset scoliosis (EOS) is the use of serial, 1-dimensional standard-of-care coronal vertical spine height (SoCVH) measurements. Any growth of the spine out of the coronal plane is missed by the SoCVH, which may underestimate the actual growth of the spine. This study set to validate the novel 3-dimensional true spine length (3DTSL) radiographic measurement technique for measuring growth of EOS patients. METHODS: 3DTSL measurement accuracy, reliability, and repeatability was assessed using 10 physical model configurations. In addition, interrater and intrarater reliabilities (IRRs) were assessed using interclass coefficient (ICC) analyses of 23 retrospective EOS patient clinical radiographs. 3DTSL measurements were compared with SoCVH measurements. RESULTS: The model assessment showed excellent accuracy with a mean error of 1.2 mm (SD=0.9; range, 0.0 to 3.0) and mean ICC of 0.999.IRR ICCs of the clinical radiographs averaged 0.952 for the 3DTSL and 0.975 for the vertical height whereas IRRs averaged 0.944 and 0.965, respectively (all P<0.001).Mean clinical 3DTSL curve lengths were 193.9 mm (SD=30.0; range, 142.8 to 276.8), whereas the SoCVH averaged 156.1 mm (SD=29.7; range, 74.7 to 207.3). The mean difference between the matched 3DTSL and SoCVH measurements was 37.8 mm (SD=21.4; range, 1.3 to 95.4) and was statistically significant (P<0.0001). On average, the 3DTSL of the measured spines was 124.2% of the measured SoCVH, with a progressive difference as the Cobb or kyphosis angles increased. CONCLUSIONS: The novel 3DTSL measurement is accurate, repeatable, and complements the current growth assessments for EOS treatments. LEVEL OF EVIDENCE: Level II-diagnostic study-development of a diagnostic criteria on basis of consecutive patients, with gold standard.

Distraction-based surgeries increase thoracic sagittal spine length after ten lengthening surgeries for patients with idiopathic early-onset scoliosis.

STUDY DESIGN: Retrospective, comparative, multicenter. OBJECTIVES: To determine if the choice of proximal anchor affects thoracic sagittal spine length (SSL) for children with idiopathic early-onset scoliosis (EOS). Debate exists as to whether spine growth is maintained during treatment for EOS. As rib- (RB) and spine-based (SB) distraction procedures may be kyphogenic, the traditional measurement of spine growth on coronal radiographs may not identify out-of-plane increase in spine length. A measure of SSL, along the spine's sagittal arc of curvature, has been validated to reliably assess the length of the thoracic spine. METHODS: Patients with idiopathic EOS treated with distraction-based systems (minimum 5-year follow-up, five lengthening surgeries) with radiographic analysis preoperatively, postimplant (L1), and during lengthening periods (L2-L5, L6-L10) were evaluated with primary outcome of T1-T12 SSL. RESULTS: We identified 34 patients (14 RB, 20 SB) with preoperative age 4.9 years (4.2 RB vs. 5.4 SB), scoliosis 72° (60° RB vs. 77° SB; p < 0.05), kyphosis 39° (50° RB vs. 34° SB; p < 0.05), and SSL 17.8 cm (15.5 RB vs. 18.5 SB; p < 0.05). After initial scoliosis correction from implantation, scoliosis remained constant over time. RB patients had greater kyphosis than SB patients: L1, 46° RB vs. 19° SB (p < 0.05); L2-L5, 50° RB vs. 27° SB (p < 0.05); L6-L10, 56° RB vs. 26° SB (p < 0.05). SSL increased for both groups from preoperative to the tenth lengthening (p < 0.05). As compared with RB patients, SB patients had higher SSL preoperatively and maintained this difference to the tenth lengthening (p < 0.05). After ten lengthening surgeries, when normalized to preoperative SSL, relative thoracic growth was greater for RB (27%) than for SB patients (19%) (p < 0.05). CONCLUSION: Regardless of proximal anchor choice, thoracic length continued to increase during the distraction phase of treatment for idiopathic EOS. LEVEL OF EVIDENCE: Level III.

Sagittal Spine Length Measurement: A Novel Technique to Assess Growth of the Spine.

STUDY DESIGN: The accuracy and repeatability of a novel sagittal spine length (SSL) radiographic measurement was examined using photographic and radiographic imaging. OBJECTIVES: To validate the new SSL technique for measuring growth in early-onset scoliosis (EOS) patients. SUMMARY OF BACKGROUND DATA: Current assessment of patient growth undergoing growth-friendly surgical treatment for EOS is the use of serial vertical spine height measurements (VH) on coronal radiographs. Spine-based distraction implants are able to control the coronal plane deformity of scoliosis, but exhibit a "law of diminishing returns" in the impact of each follow-up lengthening surgery. As these treatments are kyphogenic, we hypothesize that the increase in kyphosis is, in fact, growth out of plane, not captured by standard spine height measurements. METHODS: Measurement accuracy was assessed using 6 spine model alignments and clinical radiographs of 23 retrospective EOS patients. Inter- and intrarater reliabilities were assessed using interclass coefficient (ICC) analyses. The discrepancy between the VH and SSL was also investigated. RESULTS: The model assessment showed excellent accuracy, with a 1.54 mm (SD: 1.07, range: 0.03-3.14, p = .226) mean error and mean ICCs of 0.999. As the kyphosis increased, a progressive difference between the phantom VH and SSL was observed. Interrater reliability ICCs of the clinical radiographs averaged 0.981 and 0.804, whereas intrarater reliabilities averaged 0.966 and 0.826, for the coronal and sagittal radiographs, respectively. Mean clinical SSLs were 177.5 mm (SD: 28.5, range: 114.3-250.3), whereas the VH averaged 161.6 mm (SD: 31.8, range: 58.5-243.0), resulting in a 16.0-mm (SD: 16.7, range: 0.3-90.3, p < .0001) difference between the two measurements with a progressive difference as the kyphosis increased. CONCLUSIONS: The novel SSL measurement is accurate, repeatable, and complements the current growth assessments for EOS treatments. Until sagittal spine lengths are taken into consideration, the "law of diminishing returns" should be interpreted with caution. LEVEL OF EVIDENCE: Level II - Prospective Comparative Study.