There seems to be a "law of diminishing returns" with repeated lengthenings of dual growing rods. Repeated lengthenings still result in a net T1-S1 increase; however, this gain tends to decrease with each subsequent lengthening and over time. This phenomenon may be due to autofusion of the spine from prolonged immobilization by a rigid device.
When performing a medial opening wedge proximal tibial osteotomy, the surgeon should consider the negative effects of increased patellofemoral peak pressure.
This novel intramedullary AC ligament reconstruction may be considered when seeking to improve horizontal stability in an anatomical CC ligament reconstruction.
Arthroscopy of the knee is a widely used surgical procedure for addressing intra-articular pathology. In assessing the intra-articular structures, visualization is of paramount importance. The medial tibiofemoral compartment is often difficult to fully visualize in tight knees in which limited access can compromise surgical efficacy. Poor visualization can increase the possibility of a residual meniscal tear after attempted partial meniscectomy, as well as the possibility of iatrogenic chondral injury from arthroscopic instruments. We describe a technique that allows improved medial tibiofemoral visualization with release of the deep medial collateral ligament. We use standard arthroscopic portals, without the need for further incisions or stab holes and with minimal additional patient morbidity. This procedure allows easier exposure of the medial knee chondral surfaces and meniscus and easier use of arthroscopic instrumentation in the medial compartment.
BackgroundSeveral different surgical techniques have been described to address the coracoclavicular (CC) ligaments in acromioclavicular (AC) joint injuries. However, very few techniques focus on reconstructing the AC ligaments, despite its importance in providing stability. The purpose of our study was to compare the biomechanical properties of two free-tissue graft techniques that reconstruct both the AC and CC ligaments in cadaveric shoulders, one with an extramedullary AC reconstruction and the other with an intramedullary AC reconstruction. We hypothesized intramedullary AC reconstruction will provide greater anteroposterior translational stability and improved load to failure characteristics than an extramedullary technique.MethodsSix matched cadaveric shoulders underwent translational testing at 10 N and 15 N in the anteroposterior and superoinferior directions, under AC joint compression loads of 10 N, 20 N, and 30 N. After the AC and CC ligaments were transected, one of the specimens was randomly assigned the intramedullary free-tissue graft reconstruction while its matched pair received the extramedullary graft reconstruction. Both reconstructed specimens then underwent repeat translational testing, followed by load to failure testing, via superior clavicle distraction, at a rate of 50 mm/min.ResultsIntramedullary reconstruction provided significantly greater translational stability in the anteroposterior direction than the extramedullary technique for four of six loading conditions (p < 0.05). There were no significant differences in translational stability in the superoinferior direction for any loading condition. The intramedullary reconstructed specimens demonstrated improved load to failure characteristics with the intramedullary reconstruction having a lower deformation at yield and a higher ultimate load than the extramedullary reconstruction (p < 0.05).ConclusionsIntramedullary reconstruction of the AC joint provides greater stability in the anteroposterior direction and improved load to failure characteristics than an extramedullary technique. Reconstruction of the injured AC joint with an intramedullary free tissue graft may provide greater strength and stability than other currently used techniques, allowing patients to have improved clinical outcomes.
This study sought to determine the following: (1) Does the external fixator compromise quality of imaging obtained? (2) How do findings from the evaluation under anesthesia at the time of external fixator removal compare with the initial magnetic resonance imaging (MRI) findings? This was a retrospective study of a consecutive patient series at an academic level 1 trauma center. There were 19 consecutive patients with traumatic knee dislocations and spanning external fixator applied. Each patient had a knee MRI with the external fixator in place and examination at the time of external fixator removal. A review of knee stability at the time of external fixator removal with physical examination and stress fluoroscopy were performed. Our study revealed only minor incidence of poorly visualized structures. Clinical stability was present after fixator removal in only 11 of 14 medial collateral ligament tears, 4 of 16 lateral collateral ligament tears, 1 of 19 anterior cruciate ligament tears and 3 of 19 posterior cruciate ligament tears. MRI is a useful imaging modality in the setting of knee dislocations placed in spanning external fixators. Patients' knees largely remain unstable after external fixator removal.
The authors report a case of progressive congenital kyphoscoliosis in which the patient, a boy, originally underwent combined anterior and instrumented posterior spinal fusion at the age of 7 years and 3 months. Early proximal junctional kyphosis and implant failure mandated proximal extension of implants with 2 new rods connected to the old caudad short rods. At the 3-year follow-up, clinical and CT assessment revealed a thoracolumbar pseudarthrosis for which the patient underwent a 2-stage procedure without complication. Recordings of somatosensory evoked potentials intraoperatively were normal. Twelve hours after surgery, his neurological status started to progressively deteriorate. The patient was brought to the operating room, and the initially achieved correction was reversed by an apex-only exposure of the 4-rod system. After surgery the patient started to show progressive improvement in his neurological function. A final myelography was performed and showed free passage of the dye without evidence of obstruction. Clinically, the patient continued to improve and at his 3-month follow-up had near-complete resolution of his neurological deficits. Findings on his physical examination were normal at the final 12-year follow-up.
Despite normal findings on intraoperative neuromonitoring, a delayed neurological deficit can occur after complex spine reconstruction. Preoperative risk assessment, surgical approach, and instrumentation deserve careful attention. Advantages of a 4-rod construct are discussed in this case.
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