Search

Purpose: Determining whether to fuse a Lenke 5 curve to L3 or to L4 is often a difficult decision. The purpose of this study was to determine preoperative variables predictive of an "ideal" or "less than ideal" outcome for Lenke 5 curves instrumented to L3., Methods: A multicentre registry of adolescent idiopathic scoliosis patients was queried for surgically treated Lenke 5 curves with a lowest instrumented vertebra (LIV) of L3 and minimum 2 years of follow-up. Five seasoned surgeons qualitatively rated the 2-year postoperative images as "ideal" or "less than ideal" with respect to correction and alignment. Preoperative and postoperative radiographic variables were compared between the two groups. Multivariate regression analysis was performed to determine variables most predictive of a "less than ideal" outcome., Results: One hundred and thirty-nine patients met criteria. Twenty-three were considered "less than ideal" by ≥ 3 surgeons; 81 were unanimously "ideal". Preoperatively, the "less than ideal" group had significantly stiffer curves, greater apical translation, and greater LIV angulation and translation. Multivariate regression found that preoperative L3 translation (p = 0.009) was the single most important predictor of a "less than ideal" outcome: < 3.5 cm consistently resulted in an "ideal" outcome, while > 3.5 cm risked a "less than ideal" result., Conclusion: While multiple variables are important in achieving an "ideal" outcome in Lenke 5 curves, this study found preoperative L3 translation was the most important predictor of success with an L3 translation < 3.5 cm being a potential threshold for selecting L3 as the LIV. These slides can be retrieved under Electronic Supplementary Material.

Purpose: Previous research has shown that with certain idiopathic scoliosis curve types, performing a selective thoracic fusion (STF) is associated with an increased risk of coronal decompensation post-operatively. The purpose of the current study was to determine the influence of curve correction and fusion level on post-operative balance in STF for adolescent idiopathic scoliosis patients with pre-operative coronal decompensation., Methods: A multicenter database was queried for subjects with right Lenke 1-4C curves, pre-operative left coronal imbalance, and 2-year follow-up who underwent STF (caudal fusion level of L1 or proximal). Rates of decompensation were compared between groups with different levels of fusion. Thoracic and lumbar curve correction as well as Scoliosis Research Society-22 outcome scores were compared between groups that were post-operatively balanced or persistently decompensated., Results: 121 patients were identified with average thoracic and lumbar curves of 53° and 41°. Mean pre- and post-operative decompensations were 2.4 ± 1.0 and 1.8 ± 1.1 cm, respectively. Eighteen patients were fused short, 62 to, and 41 were fused past the stable vertebra. Ten patients were fused short, 32 to, and 78 were fused past the neutral vertebra. Incidence of post-operative decompensation was 41%. No differences in post-operative decompensation relative to the stable or neutral vertebra were noted (p = 0.66, p = 0.74). Post-operatively, those patients who were balanced had similar thoracic curve correction (58%) to those decompensated (54%, p = 0.11); however, patients balanced post-operatively had greater SLCC (45 vs 40%, p = 0.04). No differences in SRS-22 outcome scores were noted between groups (p > 0.05)., Conclusions: There was a high rate of post-operative decompensation in patients with pre-operative coronal decompensation undergoing STF. Fusion to or past the stable or neutral vertebra did not affect the risk of persistent decompensation. Attempts to improve SLCC could reduce post-operative decompensation.

Study Design: A retrospective review of prospective data OBJECTIVE:: The purpose of this study was to compare operative and nonoperative patients with similar curve magnitudes to determine motivating factors associated with surgical correction in "smaller" curves., Summary of Background Data: Despite traditional treatment recommendations on major curve angle measurements, many patients with thoracolumbar/lumbar (TH/L) curves of smaller magnitudes are unhappy and desire correction., Methods: A prospectively enrolled multicenter adolescent idiopathic scoliosis database was queried. Patients with major TH/L curves <50 degrees and low risk of progression (Risser 3, 4, and 5) were identified and grouped based on their treatment (operative vs. nonoperative). Preoperative demographic, radiographic, Scoliosis Research Society (SRS) outcome scores, and trunk shape values were compared., Results: A total of 126 patients undergoing surgical intervention and 17 patients pursuing nonoperative treatment were analyzed. The average lumbar curve of the operative group was 43 degrees (range, 35 to 49 degrees) and for the nonoperative group was 39 degrees (range, 26 to 49 degrees). The operative group was significantly younger, had larger lumbar major curve angles, lower thoracic to lumbar curve ratio, increased TH/L apical translation, and greater trunk shift (P<0.05). Only lumbar curve (P=0.018, OR=1.19) and trunk shift (P=0.01, OR=3.22) remained significant predictors of surgery in a multivariate regression analysis. SRS scores were significantly lower in the operative group for pain, self-image, function, mental health, and total (P<0.05). When SRS total score was entered into the regression, it was the only significant predictor of surgical intervention (P=0.004, OR=0.03)., Conclusions: Many patients with smaller lumbar curves have clinical deformities that are more consistent with larger curves. These smaller curves can produce similar coronal imbalance and trunk shift, with lower SRS domains that may drive patients to seek surgical treatment. What is unclear is the reason for this greater degree of imbalance in this select group of patients and whether the natural history is different for a more balanced TH/L curve., Level of Evidence: Level II-Prognostic.

Study Design: A retrospective analysis of a prospectively collected multicenter database., Objective: To identify the radiographical and clinical outcomes in Lenke 3 curves fused selectively (S) versus nonselectively (NS)., Summary of Background Data: Surgical treatment options for Lenke 3 curves include fusion of both curves (NS) or selective thoracic curve fusion (S). Selective fusion of the thoracic curve spares lumbar motion segments; however, it may result in marked residual deformity., Methods: A prospectively collected multicenter database was retrospectively reviewed for adolescent idiopathic scoliosis Lenke 3 curves treated with posterior spinal fusion with a minimum of 2 years of follow-up. Patients were divided into 2 groups: NS (nonselective fusion) and S (selective thoracic fusion). Radiographical and clinical data were compared between the groups using the unpaired Student t test and analysis of variance., Results: A total of 74 patients met our inclusion criteria, with 49 (66.2%) in the NS group and 25 (33.8%) in the S group. Overall, both groups were similar preoperatively except for lumbar Cobb (NS = 56.3°, S = 47.2°, P < 0.001), lumbar lordosis (NS = 56.9°, S = 67.2°, P = 0.001), lumbar rotational prominence (NS = 11.2°, S = 8.2°, P < 0.05), and lumbar apical translation (NS = 3.2 cm, S = 1.9 cm, P < 0.05). Postoperatively, NS fusion demonstrated significantly less coronal imbalance of 2 cm or less (NS = 10.2%, S = 56.0%, P < 0.001), better lumbar curve correction (NS = 68.2%, S = 51.9%, P < 0.001), better lumbar apical translation correction (NS = 1.2 cm, S = 2.1 cm, P < 0.01), and better percent correction of the lumbar prominence (NS = 66.5%, S = 40.4%, P < 0.05). Scoliosis Research Society Questionnaire 22 scores at 2 years were similar between the groups., Conclusion: Despite preoperatively smaller lumbar curves with less apical translation and lumbar prominence, most patients with selective fusions were out of balance postoperatively and had inferior radiographical outcomes as compared with their nonselective comparison cohort with similar patient-reported outcomes. Long-term follow-up is required to determine whether the trade-off of sparing motion segments at the expense of somewhat lessened radiographical outcomes is worthwhile.

Study Design: Retrospective review., Objective: To determine the association of patient characteristics and spinal curve parameters with Lenke curve types., Summary of Background Data: The Lenke curve classification may be used for surgical planning and clinical research., Methods: We retrospectively reviewed the records of 1912 patients with adolescent idiopathic scoliosis who underwent initial surgery at 21 years of age or younger; collected data on patient's age, patient's sex, primary curve magnitude (<50°, 50°-75°, and .75°), and Scoliosis Research Society (SRS) outcomes questionnaire (SRS-22) score; and compared that data by Lenke curve type. Analysis of variance and χ tests were used as appropriate (significance level, P ≤ 0.005). RESULTS.: Lenke types vary by sex: male patients had more major thoracic (types 1-4) than major thoracolumbar/lumbar (types 5 and 6) curves, fewer lumbar C-modifiers (32% vs. 44%), and less apical lumbar translation (1.1 vs. 1.7 cm). Lenke types vary by frequency: the most common type was 1 (50%); the least common, 4 (4%). Lenke types vary by magnitude: type 4 had the greatest percentage of large curves (52% of curves .75°), most smaller curves were types 1 and 5, and type 4 had the largest mean magnitude (78° ± 17°). Lenke types vary by patient age: type 5 curves occurred in the oldest patients (average age at surgery: 15.4 ± 2.2 vs. 14.3 ± 14.6 years for all others) despite having the lowest mean magnitude (P = 0.001); curve size was negatively correlated with age at surgery (r = -0.16, P = 0.001). Lenke types vary by patient self-image: patients with type 4 curves had lower preoperative SRS outcome scores for self-image than did patients with type 1 curves (P = 0.005)., Conclusion: Lenke types vary by sex, frequency magnitude, patient age, and patient self-image, which should be considered in designing studies.

Study Design: In vitro cadaveric study., Objective: The purpose of this study was to quantify the relative biomechanical protection resulting from "saving a level" in long spinal fusions., Summary of Background Data: "Saving levels" in spinal deformity surgery is desirable. Constructs with lowest instrumented vertebra (LIV) in the lumbar spine may increase loads on unfused lumbar intervertebral discs, leading to accelerated disc degeneration. No study to date has quantified the relative pressure changes that occur in the unfused caudal discs with progressively longer fusions., Methods: We used a validated in vitro cadaveric long fusion model to assess intradiscal pressures (IDPs) below simulated fusions. Eight fresh frozen T8-S1 specimens were instrumented from T8 to L5. A follower-type loading system and 7.5-N·m moments were applied in flexion and extension. IDP profiles were assessed with a pressure transducer. After acquiring IDP measurements at a given construct length, the rod was cut 1 level higher until LIV = T12. IDP data from each unfused disc were averaged and normalized to the mean value of the disc when immediately subjacent to the LIV., Results: In both flexion and extension, the mean normalized IDP of the unfused discs below the LIV increased with increasing fusion length. For each 1-level increase in construct length, pressure increased by 3.2% ± 4.8% in flexion and 4.3% ± 4.5% in extension for each unfused disc. Although the differences in pressure for a given unfused disc with differing LIV were not significant, there were significant differences between unfused discs at a given LIV. With shorter fusion lengths, pressure in the disc immediately subjacent to the fusion was consistently greater than for the caudal-most discs., Conclusion: Unfused caudal lumbar discs experienced increased IDPs with increasing length of instrumentation, most notably at the subjacent discs closest to the LIV.

Study Design: Retrospective case-control study., Objective: To quantify the athletic performance profiles after lumbar discectomy (LD) in a cohort of National Basketball Association (NBA) players in comparison with a control group of matched NBA players who did not undergo LD during the same study period., Summary of Background Data: LD provides symptomatic relief and improved functional outcomes in the majority of patients as assessed by validated measures such as Oswestry Disability Index, Visual Analog Scale, and Short Form-36 (SF-36). Among professional athletes, however, the goal of lumbar HNP treated by discectomy is not only to improve functional status but also, ultimately, to return the player to preinjury athletic performance levels. No study to date has compared the athletic performance profiles before and after discectomy in professional athletes., Methods: An analysis of NBA games summaries, weekly injury reports, player profiles, and press releases was performed to identify 24 NBA players who underwent LD for symptomatic lumbar HNP between 1991 and 2007. A 1:2 case: control study was performed using players without history of lumbar HNP who were matched for age, position, experience, and body mass index as control subjects (n = 48). Paired t tests were conducted on the following parameters: games played, minutes per game, points per 40 minutes, rebounds per 40 minutes, assists per 40 minutes, steals per 40 minutes, blocks per 40 minutes, and shooting percentage. For each athletic performance outcome, between-group comparisons evaluating preindex to postindex season performance were done (index season = season of surgery)., Results: In the LD group, 18 of 24 players (75%) returned to play again in the NBA, compared with 42 of 48 players (88%, P = 0.31) in the control group. One year after surgery, between-group comparisons revealed statistically significant increase in blocked shots per 40 minutes in the LD (0.18) versus control group (-0.33; P = 0.008) and a smaller decrease in rebounds per 40 minutes in the LD (-0.25) versus control group (-1.42; P = 0.049). No other performance variable was found to be significantly different between the study and control group., Conclusion: Compared with a closely matched control cohort, we found that 75% of surgical patients returned to play again in the NBA, compared with 88% in control subjects who did not undergo surgery. For those players who returned, overall athletic performance was slightly improved or no worse than control subjects.

Study Design: Retrospective review of a multicenter prospectively collected series of adolescent idiopathic scoliosis (AIS) patients., Objective: To compare uninstrumented compensatory curve spontaneous derotation of the rib hump and lumbar prominence after selective lumbar or thoracic fusions in AIS., Summary of Background Data: Coronal correction of the unfused minor curve after selective fusions in AIS has been well-documented previously. However, little has been reported regarding spontaneous correction in the axial plane of the unfused minor curve after selective AIS surgery., Methods: Patients with minimum 2-year follow-up after either a selective thoracic fusion (STF) (lowest instrumented vertebrae L2 or above), or a selective lumbar fusion (upper instrumented vertebrae T9 or below) for AIS, with an initial scoliometer value of >or=5 degrees in the minor curve were analyzed. Prospectively acquired preoperative and 2-year postoperative radiographic and scoliometer measurements of both the fused and unfused curves were compared using repeated measures and univariate analysis of variance. The data were checked for normality and equal variances, and the level of significance was set at P