Posterior spinal fusion for adolescent idiopathic scoliosis using a convex pedicle screw technique: a novel concept of deformity correction.

AIMS: We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique. PATIENTS AND METHODS: We reviewed 191 patients with a mean age at surgery of 15 years (11 to 23.3). Pedicle screws were placed at the convexity of each curve. Concave screws were inserted at one or two cephalad levels and two caudal levels. The mean operating time was 183 minutes (132 to 276) and the mean blood loss 0.22% of the total blood volume (0.08% to 0.4%). Multimodal monitoring remained stable throughout the operation. The mean hospital stay was 6.8 days (5 to 15). RESULTS: The mean post-operative follow-up was 5.8 years (2.5 to 9.5). There were no neurological complications, deep wound infection, obvious nonunion or need for revision surgery. Upper thoracic scoliosis was corrected by a mean 68.2% (38% to 48%, p < 0.001). Main thoracic scoliosis was corrected by a mean 71% (43.5% to 8.9%, p < 0.001). Lumbar scoliosis was corrected by a mean 72.3% (41% to 90%, p < 0.001). No patient lost more than 3° of correction at follow-up. The thoracic kyphosis improved by 13.1° (-21° to 49°, p < 0.001); the lumbar lordosis remained unchanged (p = 0.58). Coronal imbalance was corrected by a mean 98% (0% to 100%, p < 0.001). Sagittal imbalance was corrected by a mean 96% (20% to 100%, p < 0.001). The Scoliosis Research Society Outcomes Questionnaire score improved from a mean 3.6 to 4.6 (2.4 to 4, p < 0.001); patient satisfaction was a mean 4.9 (4.8 to 5). CONCLUSIONS: This technique carries low neurological and vascular risks because the screws are placed in the pedicles of the convex side of the curve, away from the spinal cord, cauda equina and the aorta. A low implant density (pedicle screw density 1.2, when a density of 2 represents placement of pedicle screws bilaterally at every instrumented segment) achieved satisfactory correction of the scoliosis, an improved thoracic kyphosis and normal global sagittal balance. Both patient satisfaction and functional outcomes were excellent. Cite this article: Bone Joint J 2017;99-B:1080-7.

Treatment of post-operative infections following proximal femoral fractures: our institutional experience.

Proximal femoral fractures (PFFs) are a major health concern in the elderly population. Improvements made in implants and surgical techniques resulted in faster rehabilitation and shorter length of hospital stay. Despite this, the reduced physiological reserve, associated co-morbidities and polypharmacy intake of the elderly population put them at high risk of postoperative complications particularly of infectious origin. Out of 10061 patients with proximal femoral fractures 105 (1.05%) developed surgical site infection; 76 (72%) infections occurred in patients who had sustained intracapsular (IC) fractures with the remaining 29 (28%) infections occurring in patients with extracapsular (EC) neck of femur fractures. The median number of additional surgical debridements was 2 (range 1-7). MRSA was isolated in 49 (47%) of the cases; 38 patients (36%) ultimately underwent a Girdlestone's excisional arthroplasty. Mortality at 30 days and 3 months was 10% and 31%, respectively. It was noted that post-operative hip infection predisposed to a prolonged length of stay in the acute unit and subsequently to a more dependent destination after discharge.

Femoral neck fractures secondary to renal osteodystrophy. Literature review and treatment algorithm.

Pathological fractures after minor trauma in osteopenic patients are not uncommon, but fractures due to hypocalcemic convulsions in patients with renal insufficiency are relatively rare. Though similar cases have been reported in the literature, this type of fracture is still an unusual condition. The complex underlying pathophysiological mechanisms and the poor bone mineral density signify the employment of specific hardware and a different treatment approach, especially in young adults, where the salvage of the femoral head is of utmost importance. The aim of this review is to examine the specific features of the femoral neck fractures in young individuals who suffer from renal osteodystrophy and the treatment algorithm should be followed. The patient's age, the uremic condition, the skeletal maturity and the bone properties in renal osteodystrophy are examined in relation to the priorities in osteosynthesis methods. A conclusive treatment algorithm is proposed where all the relevant parameters are incorporated.

Sensory innervation of the subregions of the scapholunate interosseous ligament in relation to their structural composition.

PURPOSE: To investigate the different types of innervation and the presence of mechanoreceptors in relation to the structural composition of the scapholunate interosseous ligament and to correlate the findings with the known mechanical properties of the ligament subregions. METHODS: Six fresh cadaveric scapholunate interosseous ligaments were divided into their 3 subregions: dorsal, palmar, and proximal. The microscopic features were investigated with use of a standard hematoxylin-eosin stain and immunostains for S-100, neurofilaments, neuron-specific enolase, protein gene product 9.5, CD31, and smooth muscle actin. The connective tissue structural composition and the presence of blood vessels and neural structures (myelinated and unmyelinated nerve fibers and mechanoreceptors) were investigated. The macroscopic anatomic details were also noted. RESULTS: The palmar subregion consists of structured, densely collagenized tissue at the core, surrounded by looser connective tissue. Myelinated nerve fibers forming fascicles accompany the interspersed blood vessels inside the ligament substance. Their concentration is greater in the proximal part of the palmar subregion, reaching a distance of approximately 150 mum from the ligament free surface. The dorsal subregion has similar structure to the palmar one, but the fibrous tissue ratio and density are higher. The proximal subregion consists of chondroid matrix and of loose connective tissue at its core. The radio-scapholunate ligament insertion is noted at the palmar aspect of the proximal subregion. Pacinian and other sensory corpuscles were found mostly at the palmar and proximal subregions. CONCLUSIONS: The scapholunate interosseous ligament is a richly innervated ligament that contributes to carpal proprioception, a fundamental element of dynamic wrist stability. The palmar subregion, apart from its major mechanical role, contains the greatest amount of the neural structures and mechanoreceptors. The dorsal subregion, with densely packed collagen fibers and limited innervation, functions mainly to constrain the scaphoid-lunate relative motion.