Timothy Hresko

Spondylolisthesis, Pelvic Incidence, and Spinopelvic Balance : A Correlation Study

Study Design. A retrospective study of the sagittal alignment in developmental spondylolisthesis. Objectives. To investigate the role of pelvic anatomy and its effect on the global balance of the trunk in developmental spondylolisthesis. Summary of Background Data. Pelvic incidence (PI) is a fundamental anatomic parameter that is specific and constant for each individual, and independent of the three-dimensional orientation of the pelvis. Recent studies have suggested an association between a high PI and patients with isthmic spondylolisthesis. Methods. The lateral standing radiographs of the spine and pelvis of 214 subjects with developmental L5–S1 spondylolisthesis were analyzed with a dedicated software allowing the calculation of the following parameters: pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and grade of spondylolisthesis. All measurements were done by the same individual and compared to those of a cohort of 160 normal subjects. Student’s tests were used to compare the parameters between the curve types and Pearson’s correlation coefficients were used to investigate the association between all parameters (&agr; = 0.01). Results. PI, SS, PT, and LL are significantly greater (P < 0.01) in subjects with spondylolisthesis, while TK is significantly decreased. PI has a direct linear correlation (0.41–0.65) with SS, PT, and LL. Furthermore, the differences between the two populations increase in a direct linear fashion as the severity of the spondylolisthesis increases. Conclusions. Since PI is a constant anatomic pelvic variable specific to each individual and strongly determines SS, PT, and LL, which are position-dependent variables, this study suggests that pelvic anatomy has a direct influence on the development of a spondylolisthesis. Study participants with an increased pelvic incidence appear to be at higher risk of presenting a spondylolisthesis, and an increased PI may be an important factor predisposing to progression in developmental spondylolisthesis.

Results and technique of unstable pediatric femoral fractures treated with submuscular bridge plating.

Abstract: Twenty-seven patients underwent submuscular bridge plating for unstable pediatric femoral fractures with contraindications to fixation with flexible intramedullary nails. This report discusses the technique and results. A precontoured plate was tunneled proximally through a small distal incision in the subvastus plane to bridge the fracture. The plate was secured to the femur, with screws placed percutaneously proximal and distal to the fracture to reduce and stabilize the fracture. A retrospective review of radiographs and clinical follow-up was analyzed for postoperative alignment, any change in alignment or instrumentation failure, bony union, clinical exam, and complications. There were no intraoperative or postoperative complications. There has been no instrumentation failure or loss of reduction. Early callus was seen by 6 to 8 weeks and stable bony union by 12 weeks in all patients. Submuscular plating is a reasonable option for operative stabilization of comminuted and unstable pediatric femoral fractures.

Spino-pelvic alignment after surgical correction for developmental spondylolisthesis

This study is a retrospective multi-centre analysis of changes in spino-pelvic sagittal alignment after surgical correction of L5–S1 developmental spondylolisthesis. The purpose of this study was to determine how sagittal spino-pelvic alignment is affected by surgery, with the hypothesis that surgical correction at the lumbo-sacral level is associated with an improvement in the shape of the spine and in the orientation of the pelvis. Whether L5–S1 high grade spondylolisthesis should or should not be reduced remains a controversial subject. A popular method of treatment has been in situ fusion, but studies have reported a high rate of pseudarthrosis, slip progression and persistent cosmetic deformity. Spinal instrumentation with pedicle screws has generated a renewed interest for reduction, but the indications for this treatment and its effect on spino-pelvic alignment remain poorly defined. Recent evidence indicates that reduction might be indicated for subjects with an unbalanced (retroverted or vertical) pelvis. This is a retrospective multi-centre analysis of 73 subjects (mean age 18 ± 3 years) with developmental spondylolisthesis and an average follow-up of 1.9 years after reduction and posterior fusion with spinal instrumentation or cast immobilisation. Spinal and pelvic alignment were measured on standing lateral digitised X-rays using a computer software allowing a very high inter and intra observer reliability. Pelvic incidence was unaffected by surgery. The most important changes were noted for grade, L5 Incidence, lumbo-sacral-angle, and lumbar lordosis, which all decreased significantly towards normal adult values. At first evaluation, pelvic tilt, sacral slope and thoracic kyphosis appeared minimally affected by surgery. However, after classifying subjects into balanced and unbalanced pelvis, significant improvements were noted in pelvic alignment in both the sub-groups, with 40% of cases switching groups, the majority from an unbalanced to a balanced pelvis alignment. The direction and magnitude of these changes were significantly different by sub-group: sacral slope decreased in the balanced pelvis group but increased in the unbalanced group, while pelvic tilt values did the opposite. While pelvic shape is unaffected by attempts at surgical reduction, proper repositioning of L5 over S1 significantly improves pelvic balance and lumbar shape by decreasing the abnormally high lumbar lordosis and abnormal pelvic retroversion. These results emphasise the importance of sub-dividing subjects with high grade developmental spondylolisthesis into unbalanced and balanced pelvis groups, and further support the contention that reduction techniques might be considered for the unbalanced retroverted pelvis sub-group.

Failure of attempted implant retention in spinal deformity delayed surgical site infections.

Study Design. A retrospective case series. Objective. To determine if implant retention is possible in spinal deformity cases which present as a delayed (greater than 3 months) surgical site infection. Summary of Background Data. The retention of spinal implants in deformity surgery is possible with an acute surgical site infection. Currently, the decision whether or not to retain implants in a delayed surgical site infection is unclear. Methods. A retrospective review of 26 cases of delayed surgical site infections after spinal deformity surgery. Data and information was recorded regarding the initial management of the surgical site infection, the number of operations performed related to the infection, and whether or not the infection could be cleared with implant retention. The number of operations, hospital days, and charges related to the treatment of the infection were recorded. Results. In this series, no patient was able to clear their infection without spinal implant removal. The number of operations required to clear the infection, length of hospitalization, and financial charges were proportionate to the timing of implant removal. Conclusion. Delayed surgical site infections after spinal instrumentation for deformity need to be treated with implant removal to clear the surgical site infection. Patients may require to undergo repeat instrumentation and fusion at a later date if they develop progressive deformity or symptomatic pseudarthrosis after implant removal.

Locking plate fixation for pediatric femur fractures.

Background: The use of locking plates for pediatric femur fractures has not been studied. Locking plate applications for fractures associated with comminution, osteopenia, or minimal bone available for purchase have been well studied in the adult trauma population. Methods: We conducted a retrospective review of children at our institution treated with a locking plate for a femur fracture. We identified 32 patients treated at an average age of 11 years (6-15 years of age). Locking plates were chosen for comminution in 13 patients, nonmalignant pathologic fracture in 9 patients, fracture location in 7 patients, and osteopenia in 3 patients. All patients were treated with a locking plate and followed up until definitive radiologic union. Results: There were no intraoperative complications related to this technology. All patients were healed with near-anatomic alignment with the exception of 1 patient who had valgus malalignment of 12 degrees, which was of no clinical concern and required no intervention. Seven patients had the plates removed with no noted complications. Conclusions: Locking plates are a safe and effective treatment for children and adolescents with femur fractures that may not be amenable to other current means of stabilization. Level of Evidence: Level IV.

Modern Cervical Spine Instrumentation in Children

Study Design. A retrospective case series. Objective. To determine the safety, efficacy, and feasibility of using modern segmental cervical spine instrumentation in children. Summary of Background Data. With the exception of transarticular screws, there are currently no series in the literature looking at the use of modern cervical spine implants in children. In the adult population, these implants have been shown to be biomechanically superior to traditional wiring methods. These constructs may also decrease the need for postoperative halo immobilization, while at the same time improving arthrodesis rates. Methods. A retrospective review of 25 pediatric patients greater than 6 years of age treated at our institution with modern segmental instrumentation of the cervical spine. Computed tomography scans were evaluated to determine containment of screws. Radiographic and chart review was done to determine the clinical outcome with respect to fusion and any complications related to surgery. Results. There were no implant related complications in this series. All screws (n = 112) evaluated by computed tomography scan were fully contained. All patients obtained union and there were no reoperations related to the spinal implants. Complications included: 1 deep infection, 1 superficial infection, and 1 transient radiculopathy. Conclusion. Modern cervical spine instrumentation is safe and feasible to use in children older than 6 years of age. The clinical union rate in our series was 100% with no implant related complications.

Implant removal after submuscular plating for pediatric femur fractures.

Background Submuscular plating for pediatric femur fracture has become more commonplace for treatment of length unstable fractures. These plates act as an internal fixator and rely on minimally invasive insertion techniques and long plate lengths to achieve the goal of stable fixation and local biologic fracture preservation. Plate removal in children after submuscular plating has not been reported in the literature. Methods We reviewed the records of 22 patients at our institution who were treated with a submuscular plate, which was eventually removed after fracture healing. A review of the radiographs and charts was performed to determine any unique problems or complications that may arise during the removal of these plates given their long lengths and minimally invasive insertion. Results In our series, 7 patients required a more extensive procedure to remove the plate than was required during plate insertion. These patients all required an open procedure at the leading edge of the plate to chisel overgrown bone away from the plate for removal. The timing of removal in our series was not related to difficulties during plate removal, rather it was the presence of bony overgrowth at the plates leading edge. This overgrowth was seen early on radiographically during the healing process in all patients who required increased operative exposure. Conclusions The timing of plate removal after submuscular plating is not critical when trying to determine the potential complications at plate removal. The decisive factor related to difficulties with plate removal is leading plate edge overgrowth. Patients with this bone overgrowth at the leading edge of the plate need to be counseled regarding the need for an increased operative exposure during plate removal. Level of Evidence Case series, level 4.

Recommendations for research studies on treatment of idiopathic scoliosis: Consensus 2014 between SOSORT and SRS non–operative management committee

The two main societies clinically dealing with idiopathic scoliosis are the Scoliosis Research Society (SRS), founded in 1966, and the international Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT), started in 2004. Inside the SRS, the Non-Operative Management Committee (SRS-NOC) has the same clinical interest of SOSORT, that is the Orthopaedic and Rehabilitation (or Non-Operative, or conservative) Management of idiopathic scoliosis patients. The aim of this paper is to present the results of a Consensus among the best experts of non-operative treatment of Idiopathic Scoliosis, as represented by SOSORT and SRS, on the recommendation for research studies on treatment of Idiopathic Scoliosis. The goal of the consensus statement is to establish a framework for research with clearly delineated inclusion criteria, methodologies, and outcome measures so that future meta- analysis or comparative studies could occur. A Delphi method was used to generate a consensus to develop a set of recommendations for clinical studies on treatment of Idiopathic Scoliosis. It included the development of a reference scheme, which was judged during two Delphi Rounds; after this first phase, it was decided to develop the recommendations and 4 other Delphi Rounds followed. The process finished with a Consensus Meeting, that was held during the SOSORT Meeting in Wiesbaden, 8–10 May 2014, moderated by the Presidents of SOSORT (JP O’Brien) and SRS (SD Glassman) and by the Chairs of the involved Committees (SOSORT Consensus Committee: S Negrini; SRS Non-Operative Committee: MT Hresko). The Boards of the SRS and SOSORT formally accepted the final recommendations. The 18 Recommendations focused: Research needs (3), Clinically significant outcomes (4), Radiographic outcomes (3), Other key outcomes (Quality of Life, adherence to treatment) (2), Standardization of methods of non-operative research (6).

Coronal plane alignment in orthotic treatment of adolescent idiopathic scoliosis: evaluation of balance parameters in orthotic outcomes

There are different ways to quantify coronal plane alignment on a radiograph, and there is a need to compare the relationship of these different methods with orthotic outcome. The purpose of this study is to investigate the relationship between methods of measuring spinal alignment and orthotic outcomes for the Boston Brace method of treating adolescent idiopathic scoliosis.