Joshua M. Pahys

Major complications in revision adult deformity surgery: Risk factors and clinical outcomes with 2- to 7-year follow-up

Study Design. Retrospective cohort comparative study. Objective. To determine the prevalence of major complications, identify risk factors, and assess long-term clinical benefit after revision adult spinal deformity surgery. Summary of Background Data. No study has analyzed risk factors for major complications in long revision fusion surgery and whether or not occurrence of a major complication affects ultimate clinical outcome. Methods. Analysis of consecutive adult patients who underwent multilevel revision surgery for spinal deformity with a minimum 2-year follow-up was performed. All complications were classified as either major or minor. Outcome analysis was conducted with the Scoliosis Research Society and Oswestry Disability Index scores. Results. A total of 166 patients (mean age = 53.8 years) were identified with a mean follow-up of 3.5 years (range: 2–7). Primary diagnoses included idiopathic/de novo scoliosis (107), degenerative (35), trauma (7), neuromuscular scoliosis (6), congenital deformity (5), ankylosing spondylitis (2), tumor (2), Scheuermann kyphosis (1), and rheumatoid arthritis (1). Most common secondary diagnoses that necessitated revision surgery were adjacent segment disease, fixed sagittal imbalance, and pseudarthrosis. Overall, 34.3% of patients developed major complications (19.3% perioperative; 18.7% follow-up). Associated risk factors for perioperative complications were patient- (age > 60 years, medical comorbidities, obesity) and surgery-related (pedicle subtraction osteotomy). Performance of a 3-column osteotomy and postoperative radiographic changes that suggested progressive loss of sagittal correction were recognized as risk factors for follow-up complications. Equivalent outcome scores were reported by patients preoperatively, but those experiencing follow-up complications reported lower scores at the final follow-up. Conclusion. Overall, 34.4% of patients experienced major complications after long revision fusion surgery. Different risk factors were identified for perioperative versus follow-up complications. The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.

Methods to decrease postoperative infections following posterior cervical spine surgery.

BACKGROUND To decrease surgical site infections, we initiated a protocol of preliminary preparation of the skin and surrounding plastic drapes with alcohol foam, and the placement of a suprafascial drain in addition to a subfascial drain in obese patients in 2004. In 2008, we additionally placed 500 mg of vancomycin powder into the wound prior to closure. The purpose of this study was to analyze the infection rates for three groups: Group C (control that received standard perioperative intravenous antibiotics alone), Group AD (alcohol foam and drain), and Group VAD (vancomycin with alcohol foam and drain). METHODS A consecutive series of 1001 all-posterior cervical spine surgical procedures performed at one institution by the senior author from 1995 to 2010 was retrospectively reviewed. These surgical procedures included foraminotomy, laminectomy, laminoplasty, arthrodesis, instrumentation, and/or osteotomies. There were 483 patients in Group C, 323 in Group AD, and 195 in Group VAD. RESULTS In Group C, nine (1.86%) of the 483 patients had an acute postoperative deep infection, in which methicillin-resistant Staphylococcus aureus was the most common pathogen. A significantly higher rate of infection was found in patients with an active smoking history (p = 0.008; odds ratio = 2.6 [95% confidence interval, 1.0 to 7.1]), rheumatoid arthritis (p = 0.005; odds ratio = 4.0 [95% confidence interval, 1.4 to 7.9]), and a body mass index of ≥30 kg/m2 (p = 0.005; odds ratio = 4.1 [95% confidence interval, 1.5 to 7.7]). Group AD (n = 323) had one infection, a significant decrease compared with Group C (p = 0.047). In Group VAD, none of the 195 patients had infections, which was also a significant decrease compared with Group C (p = 0.048). CONCLUSIONS In this study, preliminary preparation with alcohol foam and the placement of suprafascial drains for deep wounds resulted in one postoperative deep infection in 323 surgical procedures. The addition of intrawound vancomycin powder in 195 consecutive posterior cervical spine surgical procedures resulted in no infections and no adverse effects. To our knowledge, this is the first description of a technique for significantly decreasing postoperative cervical spine infections.

Computed Tomography Evaluation of Rotation Correction in Adolescent Idiopathic Scoliosis : A Comparison of an All Pedicle Screw Construct Versus a Hook-Rod System

Study Design. Retrospective review with historical cohort. Objective. Our study measures axial rotation of the apical vertebral bodies of patients with adolescent idiopathic scoliosis treated with an all pedicle screw (APS) construct versus a hook-rod (HR) construct using computed tomography (CT). Summary of Background Data. Ecker et al (Spine 1988;13:1141–4) observed a 22% derotation of the apical vertebrate of the thoracic spine and 33% of the apical vertebra of the lumbar spine when using an HR system (CD instrumentation). More recently Lee et al (Spine 2004;29:343–9) reported 42.5% derotation of the apical vertebra (both thoracic and lumbar) in a series of APS constructs. Currently, there is no comparison series reported between the 2 types of constructs. Methods. From a database of 193 patients with adolescent idiopathic scoliosis and posterior spinal fusions, 32 patients were identified as having all APS constructs with pre- and postoperative CT scans. This cohort of patients was compared with a historical published cohort of patients treated with HR constructs by Ecker et al (Spine 1988;13:1141–4) Comparison of the groups showed no statistically significant differences for age and preoperative Cobb angle of the main curve (P > 0.05); however, there was a statistically significant difference (P < 0.05) in postoperative correction values. The apical vertebral rotation for the major curve was measured from the pre- and postoperative axial CT using the methods described by Aaro and Dahlborn (Spine 1981;6:460–7). Result. The average preoperative rotation was similar between the 2 groups (thoracic: HR = 22.6, APS = 21.3, P = 0.6; lumbar: HR = 19.4, APS = 20.6, P = 0.7). The postoperative correction had a significant difference (thoracic: HR = 16, APS = 8.5, P = 0.015; lumbar: HR = 13.4, APS = 7.0, P = 0.032). The percent correction of the apical vertebrae showed a significant difference, with 22% correction in the HR group and 60% in APS group (P < 0.001). Conclusion. Our study finds axial rotation correction using APSs and a direct vertebral body derotation technique was significantly greater than that obtained with the HR construct.

Proximal Junctional Kyphosis in Primary Adult Deformity Surgery: Evaluation of 20 Degrees as a Critical Angle

BACKGROUND : Multiple studies have reported on the prevalence of proximal junctional kyphosis (PJK) following spinal deformity surgery; however, none have demonstrated its significance with respect to functional outcome scores or revision surgery. OBJECTIVE : To evaluate if 20° is a possible critical PJK angle in primary adult scoliosis surgery patients as a threshold for worse patient-reported outcomes. METHODS : Clinical and radiographic data of 90 consecutive primary surgical patients at a single institution (2002-2007) with adult idiopathic/degenerative scoliosis and 2-year minimum follow-up were analyzed. Assessment included radiographic measurements, but most notably sagittal Cobb angle of the proximal junctional angle at preoperation, between 1 and 2 months, 2 years, and ultimate follow-up. RESULTS : Prevalence of PJK ≥20° at 3.5 years was 27.8% (n = 25). Those with PJK ≥20° at ultimate follow-up were older (mean 56 vs 46 years), had lower number of levels fused (median 8 vs 11), and were proximally fused to the lower thoracic spine more often than upper thoracic spine (all P < .001). PJK ≥20° was associated with significantly higher body mass index and fusion to the sacrum with iliac screws (P < .016, P < .029, respectively). Scoliosis Research Society outcome score changes were lower for PJK patients, but not significantly different from those in the non-PJK group. CONCLUSION : PJK ≥20° in primary adult idiopathic/degenerative scoliosis does not lead to revision surgery for PJK, but is univariately associated with older age, shorter constructs starting in the lower thoracic spine, obesity, and fusion to the sacrum. The negative results, supported by Scoliosis Research Society outcome data, provide important guidance on the postoperative management of such PJK patients. ABBREVIATIONS : BMI, body mass indexLIV, lowest instrumented vertebraeODI, Oswestry Disability IndexPJ, proximal junctionalPJK, proximal junctional kyphosisSRS, Scoliosis Research SocietyUIV, upper instrumented vertebra.

Comparative analysis of clinical outcome and complications in primary versus revision adult scoliosis surgery

Study Design. A retrospective case comparison study. Objective. We compared clinical outcome and complications in adult patients who underwent primary (P) versus revision (R) scoliosis surgery. Summary of Background Data. There is a paucity of data comparing P versus R adult scoliosis patients with respect to their complication rates and clinical outcome. Methods. Assessment of 250 consecutive adult patients who underwent P versus R surgery for idiopathic or de novo scoliosis between 2002 and 2007, with a minimum 2-year follow-up, was performed. Results. There were 126 patients in the P group and 124 in the R group. Mean age at surgery (P = 51.2 vs. R = 51.6 years, P = 0.79), length of follow-up (P = 3.6 vs. R = 3.6 years, P = 0.94), comorbidities (P = 0.43), and smoking status (P = 0.98) were similar between the 2 groups. Body mass index (P = 25.5 vs. R = 27.4 kg/m2, P = 0.01), number of final instrumented levels (P = 10.5 vs. R 12.1 levels, P = 0.00), fusion to the sacrum (P = 61.0% vs. R = 87.1%, P = 0.00), osteotomy (P = 14.3% vs. R = 54.9%, P = 0.00), length of surgery (P = 6.5 vs. R = 8.2 hours, P = 0.00), and estimated blood loss (P = 1072.1 vs. R = 1401.3 mL, P = 0.05) were different. Primary patients had significantly lower overall complications than revision patients (P = 45.2% vs. R = 58.2%, P = 0.042). Primary patients reported significantly higher preoperative and final clinical outcome measures in function, pain, and subscore SRS domains and ODI compared with revision patients (all P < 0.05). Patients older than 60 years of age, however, reported similar SRS and ODI scores between the 2 groups. The extent of surgical benefit patients received, that is, final minus preoperative score, was similar in all categories between the 2 groups. Conclusion. Adult patients undergoing primary scoliosis surgery had significantly lower overall complications compared with revision patients. Primary patients reported higher preoperative and final clinical outcome measures than revision patients, although this difference disappeared in older patients. The benefit of surgery was similar between the 2 groups.

Knee reconstruction in syndromes with congenital absence of the anterior cruciate ligament.

The authors review their experience with four patients with congenital deficiency of the anterior cruciate ligament (ACL) who underwent surgical treatment of symptomatic knee instability at a mean age of 15.8 years (range 14-17 years). Associated syndromes included fibular hemimelia, congenital short femur, and an unspecified skeletal dysplasia. All patients had undergone multiple previous realignment and leg lengthening procedures and were skeletally mature at the time of the reconstruction. All four patients underwent ACL reconstruction, and one patient underwent concomitant posterolateral corner reconstruction. One patient required an osteochondral autograft transplant procedure in addition to ACL reconstruction. Hypertrophy of the meniscofemoral ligament of Humphrey was a consistent anatomic finding at surgery. The patients were followed for a mean of 38 months (range 26-58 months) after the reconstruction. The mean preoperative Lysholm II score was 38 (range 28-56); the score had improved to a mean of 81 (range 78-93) at the latest follow-up. The authors conclude that reconstructive surgery is a viable option for restoration of knee stability and function in appropriately selected patients with congenital ACL deficiency.

Transforaminal versus anterior lumbar interbody fusion in long deformity constructs: a matched cohort analysis.

Study Design. Prospectively enrolled, retrospectively analyzed matched cohort analysis. Objective. Evaluate the relative merits of transforaminal lumbar interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) when performed in long deformity constructs. Summary of Background Data. Interbody fusion is frequently used at the caudal levels of long-segment spinal deformity instrumentation constructs to protect the sacral implants and enhance fusion rates. However, there is a paucity of literature regarding which technique is more efficacious. Methods. Forty-two patients who underwent TLIF and 42 patients who underwent ALIF were matched with respect to age, sex, comorbidities, curve magnitude, fusion length, and ALIF/TLIF level. Radiographs and clinical outcomes were compared at minimum 2-year follow-up. Results. Age averaged 54.0 years and instrumented vertebrae averaged 13.6. TLIFs had less operative time (481 vs. 595 min, P = 0.0007), but greater blood loss (2011 vs. 1281 mL, P = 0.0002). Overall complications (TLIF, 12/42 vs. ALIF, 15/42) and neurological complications (TLIF, 4/42 vs. ALIF, 3/42) did not differ. One pseudarthrosis occurred at an ALIF level, with none at TLIF levels. Patients who underwent ALIF began with lower SRS scores but showed more improvement (44.4 to 70.7 vs. 58.6 to 70.6, P = 0.0043). ODI scores in both groups improved similarly. Regionally, ALIFs engendered more lordosis than TLIFs at L3–S1 (gain of 6.9° vs. −2.6°, P < 0.0001) but not T12-S1 (gain of 11.5° vs. 7.9°, P = 0.29). Locally, ALIFs created more lordosis at L4–L5 (gain of 5.6° vs. −1.7°, P < 0.0001) and L5–S1 (gain of 2.5° vs. −1.4°, P = 0.022), but not at L3–L4 (gain of 5.3° vs. 4.0°, P = 0.65). Patients who underwent TLIF obtained greater correction of anteroposterior Cobb angles in lumbar (reduction of 22.4° vs. 9.9°, P < 0.0001) and lumbosacral curves (reduction of 10.3° vs. 3.4°, P < 0.0001). Conclusion. Spinal deformity surgery used TLIFs rather than ALIFs resulted in shorter operative time with no difference in complication rates. ALIFs provided more segmental lordosis, whereas TLIFs afforded better correction of scoliotic curves.

Intraspinal anomalies in infantile idiopathic scoliosis: prevalence and role of magnetic resonance imaging.

Study Design. Retrospective case series of magnetic resonance imaging (MRI) findings in patients with presumed infantile idiopathic scoliosis (IIS). Objective. To identify the prevalence of intraspinal anomalies in patients with presumed IIS at a single, large volume institution and further define the role for a screening MRI. Summary of Background Data. Idiopathic scoliosis in patients less than 10 years of age has been shown to carry a higher prevalence of concordant intraspinal anomalies, up to 20%, in juveniles, when compared to the adolescent age group. Few studies exist assessing the prevalence of intraspinal anomalies in the IIS patient population. Dobbs et al (2002) reported a 21.7% prevalence of neural axis abnormalities in 46 patients with presumed IIS across 3 combined spinal deformity clinics and recommended a screening MRI for all IIS patients with a curve >20°. Methods. A retrospective review of the medical records of 54 patients at a single institution with a presumed diagnosis of IIS was performed. All patients satisfied the strict inclusion criteria of: curve ≥20°, age <36 months at diagnosis, normal neurologic examination (i.e., normal tone, motor strength, reflexes, etc.), absence of any concomitant syndromes or congenital anomalies, and an MRI of the spine from skull to coccyx. Results. MRI revealed a neural axis abnormality in 7 (13%) of 54 patients who underwent an MRI. In this subset of 7 patients, 5 (71.4%) required neurosurgical intervention. Tethered cord requiring surgical release was identified in 3 patients, Chiari malformation requiring surgical decompression was found in 2 patients, and a small nonoperative syrinx was found in 2 patients. Conclusion. This study represents the largest evaluation of intraspinal anomalies in IIS to date. Our patient population exhibited a smaller percentage (13%) of neural axis abnormalities than previously reported. On the basis of these findings, the close observation may be a reasonable alternative to an immediate screening MRI in patients presenting with presumed IIS and a curve >20°.

The posterior pedicle screw construct: 5-year results for thoracolumbar and lumbar curves

OBJECT Several studies of the outcomes of patients with adolescent idiopathic scoliosis (AIS) with thoracolumbar and lumbar curves after treatment with posterior pedicle screws have been reported, but most of these studies reported only 2-year follow-up. The authors analyzed the radiographic and clinical outcomes of patients with thoracolumbar and lumbar curves treated with posterior pedicle screws after 5 years of follow-up. METHODS A multicenter database was retrospectively queried to identify patients with AIS who underwent spinal fusion for Lenke 3C, 5C, and 6C curves. Radiographs from the following times were compared: preoperative, first follow-up visit, 1-year follow-up visit, 2-year follow-up visit, and 5-year follow-up visit. Chart review included scoliometer measurements, Scoliosis Research Society (SRS)-22 questionnaires, and complications requiring return to the operating room. RESULTS Among 26 patients with Lenke 3C, 5C, and 6C curves, the mean (± SD) age was 14.6 ± 2.1 years. From the time of the preoperative radiographs to the 5-year follow-up radiographs, there was a statistically significant improvement in the mean coronal lumbar Cobb angles (p < 0.0001), and from the time of the first postoperative radiographs to the 5-year follow-up radiographs, the lumbar curve remained stable (p = 0.14). From the time of the preoperative radiographs to the 5-year follow-up radiographs, there was a statistically significant improvement in the mean coronal thoracic Cobb angles (p < 0.0001), and from the time of the first postoperative radiographs to the 5-year follow-up radiographs, the thoracic curve remained stable (p = 0.10). From the first postoperative visit to the 5-year follow-up visit, the thoracic kyphosis (T5-12) remained stable (p = 0.10), and from the time of the preoperative radiographs to the 5-year follow-up radiographs, the lumbar lordosis (T-12 to top of sacrum) remained stable (p = 0.44). From the preoperative visit to the 5-year follow-up visit, the coronal balance improved significantly (p < 0.05) and remained stable from the first postoperative visit to the 5-year follow-up visit (p = 0.20). The SRS-22 total scores improved significantly from before surgery to 5 years after surgery (p < 0.0001). No patients required reoperation because of complications. CONCLUSIONS Correction of the coronal, sagittal, and axial planes in this cohort of patients was maintained from the first follow-up measurements to 5 years after surgery. In addition, at 5 years after surgery total SRS-22 scores and inclinometer readings were improved from preoperative scores and measurements.

Unplanned return to the operating room in patients with adolescent idiopathic scoliosis: are we doing better with pedicle screws?

Study Design. Prospective, longitudinal cohort. Objective. To evaluate the incidence, timing, and risk factors for reoperation in patients with adolescent idiopathic scoliosis (AIS) treated with pedicle screws (PSs) compared with hybrid (Hb) constructs. Summary of Background Data. Rates of return to the operating room (OR) after definitive fusion for AIS vary, with a paucity of data on PS constructs. Methods. A prospective multicenter database was retrospectively queried to identify consecutive patients with AIS who underwent posterior spinal fusion with either PS or Hb constructs with a minimum 2-year follow-up. All reoperations were stratified into an early group (<60 d) or a late group (>60 d). Univariate and multivariate logistical analyses were performed to identify potential risk factors related to reoperation. Results. A total of 627 patients met the inclusion criteria (PS = 540, Hb = 87). There was a statistically significant difference in the rate of reoperations between the PS (3.5%) and Hb groups (12.6%), P < 0.001. Early return to the OR occurred in 2.0% of the patients with PS compared with 3.4% in the Hb group, P = 0.43. Late returns to the OR occurred in 1.5% of PS group versus 9.2% of the Hb group, P < 0.001. Multivariate analysis revealed longer operating time as an independent risk factor for an unplanned return to the OR in patients treated with PSs (P < 0.05). Conclusion. Our results suggest that patients with AIS treated with PS have decreased rates of unplanned return to the OR when compared with patients with Hb constructs. The majority of returns to the OR were early (<60 d) for the PS group compared with late (>60 d) for the Hb group. Longer operative times increased the risk of unplanned reoperation for the PS group. Level of Evidence: 3