Kümmell's Disease: Clarifying the Mechanisms and Patients' Inclusion Criteria.

The three major causes of vertebral body collapse include infection, malignant neoplasia, and trauma and it may be difficult to distinguish between them, particularly in the presence of severe osteoporosis. In 1891, however, Dr Hermann Kümmell, further added another possibility of vertebral body crush; the delayed posttraumatic collapse. As originally described, this rare clinical entity includes patients, who after a trivial trauma and an asymptomatic clinical course they develop a progressive vertebral body collapse and a painful kyphosis. Although more than a century has passed from its initial description, only few cases have been reported in the literature, whereas the main pathologic eliciting event is still under investigation. As a consequence, great controversy exists regarding the discrete features of the clinical course, its radiographic appearance and the histopathological findings. To explain the time lag between the initial trauma and the occurrence of the vertebral collapse, the hypothesis of ischemic necrosis was advanced. Equation of Kümmell's disease with vertebral osteonecrosis, however, has wrongly led many authors to report cases of Kümmell's disease, even in the absence of history of spinal trauma. On the other hand, high coincidence of vertebral osteonecrosis and the pathognomonic radiographic finding of intravertebral vacuum cleft, has further added to the confusion. In this review we present an overview of the literature on Kümmell's disease, focusing on the different proposed eliciting mechanisms. We also highlight controversial subjects on clinical course, diagnosis and treatment of this entity, in an attempt to further clarify patients' inclusion criteria.

Removal of well-fixed components in femoral revision arthroplasty with controlled segmentation of the proximal femur.

BACKGROUND: The transfemoral and the extended trochanteric osteotomies are the most common osteotomies used in femoral revision, both when proximal or diaphyseal fixation of the new component has been decided. We present an alternative approach to the trochanteric osteotomies, most frequently used with distally fixated stems, to overcome their shortcomings of osteotomy migration and nonunion, but, most of all, the uncontrollable fragmentation of the femur. METHODS: The procedure includes a complete circular femoral osteotomy just below the stem tip to prevent distal fracture propagation and a subsequent preplanned segmentation of the proximal femur for better exposure and fast removal of the old prosthesis. The bone fragments are reattached with cerclage wires to the revision prosthesis, which is safely anchored distally. A modified posterolateral approach is used, as the preservation of the continuity of the abductors, the greater trochanter, and the vastus lateralis is a prerequisite. RESULTS: Between 2006 and 2012, 47 stems (33 women, 14 men, mean age 68 years, range 39-88 years) were revised using this technique. They were 12 (26%) stable and 35 (74%) loose prostheses and were all revised to tapered, fluted, grit-blasted stems. No fracture of the trochanters or the distal femur occurred intraoperatively. Mean follow-up was 28 months (range 6-70 months). No case of trochanteric migration or nonunion of the osteotomies was recorded. Restoration of the preexisting bone defects occurred in 83% of the patients. Three patients required repeat revision due to dislocation and one due to a postoperative periprosthetic fracture. None of the failures was attributed to the procedure itself. CONCLUSIONS: This new osteotomy technique may seem aggressive at first, but, at least in our hands, has effectively increased the speed of the femoral revision, particularly for the most difficult well-fixed components, but not at the expense of safety.

Kümmell's disease: pathophysiology, diagnosis, treatment and the role of nuclear medicine. Rationale according to our experience.

Kümmell's disease (KD) is a rare clinical entity and includes patients, who after a trivial trauma and an asymptomatic period, develop a progressive vertebral body collapse and a painful kyphosis. The main pathologic eliciting event still remains unclear. Vertebral body collapse can be the result of infection, malignant neoplasia or trauma. It may be difficult to distinguish among them, particularly in osteoporosis. To explain the time lag between initial trauma and vertebral collapse, the hypothesis of ischemic necrosis was suggested. Many authors considering KD as a case of mere vertebral osteonecrosis have wrongly reported cases of osteonecrosis without a spinal trauma, as KD. The fact that intravertebral vacuum cleft often coexists with vertebral osteonecrosis further added to confusion. Various imaging modalities including bone scan support the diagnosis of KD. It is described that bone single photon emission tomography (SPET) or SPET/computed tomography scintigraphy using dynamic and static, acquisition can identify the chronicity of the lesions.

Dual-fibular reconstruction of a massive tibial defect after Ewing's sarcoma resection in a pediatric patient with a vascular variation.

BACKGROUND: In the management of malignancies of the extremities, limb salvage procedures have recently taken on greater significance. For those patients under intense adjuvant chemotherapy and with massive bone loss, free vascularized fibular grafting is currently advocated as a reliable reconstructive option, maybe because of the controversial results of bone transport in similar situations. However, when there is a vascular abnormality of either the recipient or donor extremity, microsurgical procedures are not feasible, further limiting potential reconstructive alternatives. METHODS: We present the case of a 13-year-old female patient with Ewing's sarcoma of the right tibia. Preoperative angiography showed that vascularity of the affected side depended totally on a single peroneal artery. The patient was treated initially with multiagent chemotherapy, followed by an excision of 23 cm. The defect was bridged by a gradual medial transportation of the ipsilateral fibula with the Ilizarov technique and strengthened by nonvascularized transfer of the contralateral fibula. RESULTS: Total external fixation time was 162 days. After the removal of the Ilizarov frame a walking cast was applied for another month. At 5 years postoperatively there was no recurrence of the malignancy. The patient had full weight-bearing ability on the affected limb, with preservation of the ankle and knee joints motion and without any limb length discrepancy or axial deformity. The functional outcome that was visible was graded excellent. CONCLUSIONS: Transverse distraction osteogenesis of the ipsilateral fibula performed well under chemotherapy, showing unproblematic callus formation. Supplemented with nonvascularized transfer of the contralateral fibula, provided a reconstructive option with biological affinity, sufficient biomechanical strength and durability, and with a decreased complication rate. This case report presents a viable option, especially in cases in which vascular abnormalities of either the donor or the recipient limb, combined with multiagent chemotherapy, restrict potential reconstructive alternatives. It also highlights why vascularized bone graft should not be regarded as a panacea for all situations in which a fibular graft is required. LEVEL OF EVIDENCE: Level IV, case report.

Kümmell' s disease: A rare spine entity in a young adult.

Over 100 years ago, Dr Hermann Kümmell described a rare clinical entity in which patients, after a trivial trauma and an asymptomatic period, developed a progressive vertebral body collapse and a painful kyphosis. We present the case of a 31years old heavy labourer, fitting Kümmell's criteria. The patient referred to us in an incapacitated state, due to persistent back pain. Radiographic examination revealed a body collapse of L1 vertebra. The patient had no previous medical record, other than a prolonged history of transient back pain episodes, related to heavy-weight lifting. Last attack was 1 year before presentation. Through course of time, he had undergone several clinical and radiological evaluations, by different orthopaedists, on different occasions, including the last episode, with no major findings. After an extensive workup, a percutaneous kyphoplasty of the affected vertebra was performed and a biopsy was obtained. The histologic examination of the specimen revealed vertebral osteonecrosis. A triggering pattern of repetitive spinal loading in hyperflexion is, for the first time, being recognized. We conclude that Kümmell's disease, although a rare condition, should be considered in any patient with refractory back pain symptoms. In such patients, vigorous follow-up turns to be of the essence.