John E. Tis

Analysis of sagittal alignment in thoracic and thoracolumbar curves in adolescent idiopathic scoliosis: how do these two curve types differ?

Study Design. Retrospective chart review and radiographic analysis. Objective. To determine if differences exist in the sagittal alignment of adolescent idiopathic scoliosis (AIS) patients with thoracic versus thoracolumbar curve patterns. Summary of Background Data. Relative anterior overgrowth has been suggested as the possible pathomechanism behind thoracic scoliosis. Given the proposed importance of the sagittal alignment on the development of AIS and the known association between pelvic parameters and sagittal alignment, the authors postulate that pelvic incidence may influence the location of vertebral column collapse associated with different AIS curve types. Methods. A multicenter surgical database was used to compare preoperative radiographic measurements between patients with primary thoracic curves (Lenke 1A, B), primary thoracolumbar curves (Lenke 5), and normal adolescents. Results. Pelvic incidence was significantly greater in both groups of AIS patients compared with normal adolescents. Patients in the primary thoracic curve group were found to have a significantly increased sacral slope and a decreased thoracic kyphosis relative to the control group. Patients in the primary thoracolumbar curve group had a significantly increased pelvic tilt; however, a relatively normal thoracic kyphosis, lumbar lordosis, and sacral slope compared with the respective control values. Conclusion. An increased pelvic incidence, associated with both thoracic and thoracolumbar curves when compared with the normal adolescent population, does not appear to be the potential determinant of the development of thoracic versus thoracolumbar scoliosis, but may be a risk factor for the development of adolescent idiopathic scoliosis. The theory of anterior overgrowth may be supported by the identification of thoracic hypokyphosis, despite an increased pelvic incidence and lumbar lordosis, in patients with thoracic scoliosis. The association between sagittal measurements and the etiology of thoracolumbar curve formation is less clear; however, regional anterior overgrowth in the lumbar spine may also be responsible for the deformity.

Fatal rhabdomyolysis with bilateral gluteal, thigh, and leg compartment syndrome after the Army Physical Fitness Test. A case report.

Acute exertional rhabdomyolysis is a clinically variable syndrome resulting from the lysis of skeletal muscle cells and the release of myoglobin and other cellular components into the circulation. The classic description by Knochel is that of a patient who has confusion, pallor, and hyperthermia, followed by renal failure, hyperkalemia, and disseminated intravascular coagulation. Relatively recent reports suggest that this entity may be more common than previously appreciated, and that it is not always accompanied by hyperthermia and renal failure. In addition, rhabdomyolysis may be associated with severe metabolic disturbances and compartment syndrome. Multiple causes of rhabdomyolysis have been identified, including crush injury and direct compression. Compartment syndrome of the thigh after exercise is considered an extremely rare condition. The first case of exercise-induced acute compartment syndrome of the thigh was reported by Kahan et al. in 1994. Gluteal compartment syndrome is even less common, and to our knowledge, exercise-induced gluteal compartment syndrome has not been previously described in the literature. This report illustrates a fatal case of acute exertional rhabdomyolysis complicated by multisystem organ failure, and bilateral leg, thigh, and gluteal compartment syndromes.

Adolescent Idiopathic Scoliosis Treated With Open Instrumented Anterior Spinal Fusion: Five-Year Follow-up

Study Design. A multicenter prospective database was queried for patients who underwent open instrumented anterior spinal fusion (OASF) for treatment of primary thoracic (Lenke 1) adolescent idiopathic scoliosis (AIS). Objectives. To present the intermediate radiographic and pulmonary function testing (PFT) data from patients who underwent OASF using modern, rigid instrumentation. Summary of Background Data. Anterior spinal fusion is an excellent method to correct the 3-dimensional deformity produced by AIS. Modern instrumentation consisting of stronger metals, unthreaded rods, and dual rod systems should theoretically decrease the incidence of rod breakage, pseudarthrosis, and loss of correction seen in earlier OASF studies. The paucity of intermediate and long-term data prevents surgeons and patients from making an informed decision regarding the true incidence of these complications. Methods. Of 101 potential patients who underwent OASF with a minimum 5-year follow-up, 85 (85%) were studied. Standing radiographs were analyzed before surgery and at first standing erect, 2-year, and 5-year follow-up. PFT data were collected before surgery and at 5 years after surgery. Results. Complete 5-year follow-up was obtained in 85 patients. Five years after surgery, the mean coronal correction was 26° (51%; P < 0.05) and the thoracolumbar/lumbar curve improved 16° (51%). There was a 9-degree (P < 0.001) increase in kyphosis, and there were 9 patients (11%) in whom the C7 plumb line translated >2 cm. There was a 6.7% decrease in predicted FEV1 over the 5-year period, from 75.5% ± 13% before surgery to 68.8% ± 2% at 5-year follow-up (P = 0.007); however, there was no significant change in FVC. There were 3 significant adverse events: 1 implant breakage requiring reoperation and 2 cases of progression of the main thoracic curve requiring reoperation. Conclusion. OASF is a reproducible and safe method to treat thoracic AIS. It provides good coronal and sagittal correction of the main thoracic and compensatory thoracolumbar/lumbar curves that is maintained with intermediate term follow-up. In skeletally immature children, this technique can cause an increase in kyphosis beyond normal values, and less correction of kyphosis should be considered during instrumentation. As with any procedure that employs a thoracotomy, pulmonary function is mildly decreased at final follow-up.

A biomechanical comparison of different types of lumbopelvic fixation.

Study Design. Comparative biomechanical testing in calf spines. Objective. To biomechanically evaluate 4 techniques of lumbosacral fixation. Summary of Background Data. Pelvic fixation is a problematic area, and currently, the preferred method of pelvic fixation is controversial. Clinically, iliac screws have demonstrated decreased rod breakage rates, and better correction of pelvic obliquity than unthreaded rods (Galveston technique), but several modern methods of iliac fixation have not been compared. Methods. A total of 32 male calf spines were tested under axial rotation, flexion/extension, and lateral bending. Following intact testing, specimens were instrumented in the following groups: group 1—Modified Galveston technique with rods connected directly to iliac screws (no S1 fixation); group 2—S1 screws and iliac screws with offset connectors distal to S1; group 3—S1 screws and iliac screws with offset connectors coupled to the longitudinal rod between L6 and S1; and group 4—S1 and S2 screws without iliac fixation. Pedicle screws were placed from L3 to L6. Following nondestructive testing, specimens were fixed at the cephalad aspect of the construct and flexed to failure, with peak failure moment (Nm). Results. Group 1 demonstrated significantly more flexion/extension than groups 2, 3, 4 (P < 0.001). There were no significant differences between groups for lateral bending or axial rotation at L3–S1 or L6–S1. During destructive testing, group 4 showed a significant reduction in peak failure compared to group 1 (P < 0.001), group 2 (P = 0.001), and group 3 (P < 0.001). There was no significant difference between groups 1, 2, and 3 and all specimens failed at the distal fixation. Conclusion. With extension of instrumentation across the lumbosacral junction, our results indicate significant improvement in stability with the use of S1 screws and iliac screw fixation. Furthermore, there does not appear to be any significant difference in the location of the connector for the iliac screw.

Outcome after foot and ankle deformity correction using circular external fixation

Background: External fixation is the method of choice for correction of chronic severe foot and ankle deformities. We report our experience and outcomes of circular external fixation. Methods: Fifty-five patients (60 feet) were treated with circular external fixation. The mean age at surgery was 36 (range 16 to 65) years. The mean followup was 4.4 (range 1 to 10) years. The mean time spent in external fixation was 2.1 (range 1 to 12) months. Results: There were six excellent, 35 good, eight fair, and six poor results, five of which had below knee amputations. All the patients who had an amputation were treated for infected nonunion of the ankle. Conclusion: Circular external fixation was found to be an effective method for treating a variety of complex foot and ankle problems. The complications were more common in patients with infected nonunions.

Low-intensity pulsed ultrasound does not enhance distraction callus in a rabbit model.

Low-intensity pulsed ultrasound has been reported to have a positive effect when applied during the consolidation phase of distraction osteogenesis and bone transportation, but the optimal application time has not been determined. We used a rabbit model to determine whether low-intensity pulsed ultrasound applied during the distraction and early consolidation phases of tibial lengthening would have a positive effect on regenerated bone formation. Radiographic analysis showed no differences in regenerated callus area or in percent of callus mineralization between treated and control tibias immediately after distraction or at 1, 2, or 3 weeks after distraction. Similarly, we observed no differences in structural stiffness or maximal torque to failure at 1.5 or 3 weeks after distraction. We detected no differences in bone mineral appositional rates or percent tissue composition measured histologically between groups. Our data do not support the application of low-intensity pulsed ultrasound to regenerated bone during distraction osteogenesis.

Pigmented villonodular synovitis of the calcaneocuboid joint in an 11-year-old child with subtalar coalition.

Pigmented villonodular synovitis (PVNS) is a locally destructive benign soft-tissue tumor that involves tissue structures with synovial linings, such as joints, tendon sheaths, and bursae. In 1941, Jaffe et al.11 published the first series of PVNS cases. They selected the term pigmented villonodular synovitis to describe the gross appearance of this tumor. PVNS is a fibrohystiocytic proliferation characterized by multiple villous projections from a dense nodular base with a brownish pigmentation secondary to hemosiderin deposits.11 There is controversy in the literature as to whether PVNS is a neoplasm or a reactive proliferation. Regardless, it has no malignant potential, but its proximity to major weightbearing joints can result in severe and rapid joint deterioration, leading to significant impairment. Although considered idiopathic, a recent genetic study, demonstrated a nonrandom association between PVNS and trisomy of chromosome 7.8 PVNS shares many similarities with localized nodular synovitis and giant cell tumor of tendon sheath. Often the latter two are referred to as extraarticular PVNS; however, these two lesions typically affect focal portions of the synovium, while PVNS is a more diffuse process. As a result, simple excision is curative in most cases of extra-articular PVNS, especially those of the foot and ankle.10 The clinical course of intra-articular PVNS, however, is characterized by progressive joint destruction, frequent recurrence, and the need for subtotal or total synovectomy. It is the difference in clinical course that mandates separate diagnosis, treatment, and discussion for these histologically similar entities.

Contralateral Structural Femoral Autograft Use in Treatment of an Open Periarticular Knee Fracture to Perform Knee Arthrodesis

Combat-related blast injuries often cause devastating extremity trauma. We report a case of a 21-year-old male servicemember who sustained massive bilateral lower extremity trauma secondary to a blast injury. His orthopaedic injuries included a near traumatic disarticulation of the right knee and a left open type IIIB periarticular knee fracture with traumatic patellectomy, loss of the extensor mechanism, and segmental loss of the distal 11 cm of his femur. Definitive treatment of his injuries included a contralateral structural cortical femoral autograft which was implanted into the left knee segmental defect to facilitate knee fusion with an intramedullary knee fusion nail and a right transfemoral amputation. Radiographic evidence of solid fusion was obtained 8 months postoperatively. Currently, the patient is a community ambulator with the aid of his right lower extremity prosthetic limb and cane.