Treatment of Intertrochanteric Femur Fractures with Long versus Short Cephalomedullary Nails.

CONTEXT: Prior studies regarding indications for long vs short cephalomedullary nails in the treatment of intertrochanteric fractures had limited sample sizes and follow-up, suggesting a need for further investigation. OBJECTIVE: To evaluate the association between cephalomedullary nail length and outcomes for the treatment of intertrochanteric femur fractures. DESIGN: Cohort study using Kaiser Permanente's Hip Fracture Registry. A total of 5526 patients who underwent surgical treatment with cephalomedullary nails for an intertrochanteric femur fracture (2009-2014) were identified: 3108 (56.2%) with long nails and 2418 (43.8%) with short nails. Cox proportional hazards model regression was used to evaluate risks of all-cause revision and revision for periprosthetic fracture. Linear regression was used to evaluate operative time, estimated blood loss, and length of stay. Propensity score weights were used in all models to balance nail groups on patient and device characteristics. MAIN OUTCOME MEASURES: All-cause revision surgery. RESULTS: No association was found in risk of all-cause revision (hazard ratio = 0.75, 95% confidence interval [CI] = 0.48-1.15) or revision for periprosthetic fracture (hazard ratio = 0.59, 95% CI = 0.23-1.48) for long nails compared with short nails. Use of longer nails resulted in 18.80 more minutes of operative time (95% CI = 17.33-20.27 minutes), 41.10 mL more of estimated blood loss (95% CI = 31.71-50.48 mL), and a longer hospitalization (8.4 hours; ß = 0.35, 95% CI = 0.12-0.58 hours). CONCLUSION: These findings suggest that routine use of short cephalomedullary nails is safe and effective in the treatment of intertrochanteric fractures.

Models of hemorrhagic shock: differences in the physiological and inflammatory response.

INTRODUCTION: The hemorrhagic shock (HS) model is commonly used to initiate a systemic post-traumatic inflammatory response. Numerous experimental protocols exist and it is unclear how differences in these models affect the immune response making it difficult to compare results between studies. The aim of this study was to compare the inflammatory response of different established protocols for volume-controlled shock in a murine model. METHODS: Male C57/BL6 mice 6-10 weeks and weighing 20-25 g were subjected to volume-controlled or pressure-controlled hemorrhagic shock. In the volume-controlled group 300 µl, 500 µl, or 700 µl blood was collected over 15 min and mean arterial pressure was continuously monitored during the period of shock. In the pressure-controlled hemorrhagic shock group, blood volume was depleted with a goal mean arterial pressure of 35 mmHg for 90 min. Following hemorrhage, mice from all groups were resuscitated with the extracted blood and an equal volume of lactated ringer solution. Six hours from the initiation of hemorrhagic shock, serum IL-6, KC, MCP-1 and MPO activity within the lung and liver tissue were assessed. RESULTS: In the volume-controlled group, the mice were able to compensate the initial blood loss within 30 min. Approximately 800 µl of blood volume was removed to achieve a MAP of 35 mmHg (p<0.001). No difference in the pro-inflammatory cytokine (IL-6 and KC) profile was measured between the volume-controlled groups (300 µl, 500 µl, or 700 µl). The pressure-controlled group demonstrated significantly higher cytokine levels (IL-6 and KC) than all volume-controlled groups. Pulmonary MPO activity increased with the severity of the HS (p<0.05). This relationship could not be observed in the liver. CONCLUSION: Volume-controlled hemorrhagic shock performed following current literature recommendations may be insufficient to produce a profound post-traumatic inflammatory response. A decrease in the MAP following blood withdrawal (300 µl, 500 µl or 700 µl) was usually compensated within 30 min. Pressure-controlled hemorrhagic shock is a more reliable for induction of a systemic inflammatory response.

Analysis of migration of press-fit porous-coated acetabular components with medial lucencies using Ein-Bild-Roentegen-Analyse.

A total of 136 patients who underwent total hip arthroplasty (154 hips) with press-fit acetabular components were evaluated for the presence of medial radiographic lucencies. Thirty patients (22.1%) demonstrated radiolucencies greater than 1 mm in zone 2 on initial postoperative films. Ein-Bild-Roentegen-Analyse (EBRA) was used to evaluate component migration over a 5-year follow-up period. Migration, measured by EBRA, was not observed during the first 6 months when the radiolucencies were noted to disappear. After 2 years, the mean total migration was 0.8 mm, and at 5 years, it was 1.6 mm. Our results indicate that disappearance of a medial radiolucency seen on early postoperative radiographs is not associated with component migration, which supports the concept that the medial radiolucency fills in with bone or represents bony remodeling around a stable implant.

Fractures of the calcaneal tuberosity treated with suture fixation through bone tunnels.

Fractures of the calcaneal tuberosity, although rare, present a challenge for the treating surgeon. The goal of treatment is restoration of function of the gastrocnemius-soleus complex and the Achilles tendon. These fractures often occur in diabetics and elderly osteoporotic patients and therefore fixation of the displaced fragment is difficult. Displaced fractures, if not recognized and promptly reduced, often result in secondary soft tissue compromise. Often, the fragment is a small shell of osteoporotic bone, which is less than optimal for bony fixation. We present our technique for surgical fixation of calcaneal tuberosity fractures using a suture placed through bone tunnels in the calcaneal body. This technique is used by itself for smaller fragments or supplemented with screw fixation for larger fragments.

Use of circular external fixation to maintain foot position during free tissue transfer to the foot and ankle.

Limb salvage techniques of traumatized extremities using free-tissue transfer and microsurgical techniques have become standard reconstructive methods. To our knowledge there is no published data on the incidence or likelihood of equinus following free tissue transfer about the ankle, although in our experience we have perceived an unacceptable incidence of equinus following free tissue transfers about the ankle and therefore initiated prophylactic ring fixation across the ankle. Fourteen patients were placed in circular external fixation spanning the ankle at the time of free tissue transfer for a mean of 12 weeks (Median 7 weeks, Range 6-28 weeks). The results were evaluated using the degree of active ankle dorsiflexion and return to independent ambulation. Six patients had excellent results with active ankle dorsiflexion beyond neutral, and four patients had good results with neutral ankle alignment that did not require further intervention. All patients saved their limb and returned to independent ambulation. When performing free tissue transfer about the ankle, temporary spanning with a circular fixator is effective in preventing equinus deformity and provides a stable mechanical construct protecting the flap.

Correlation of angulation on initial and healed radiographic views of surgical humerus neck fractures.

This retrospective study evaluated the correlation of the angulation on initial and healed radiographs of displaced surgical humerus neck fractures treated nonoperatively, with emphasis on the initial axillary view. Thirty-six patients with displaced isolated surgical humerus neck fractures were treated nonoperatively to union. Fracture angulation of the injury and healed views were measured. Angulation on the initial axillary view was a poor predictor of angulation at union. Initial axillary radiographs of surgical neck fractures treated nonoperatively overestimated final angulation, with the Y view being more predictive of angulation at union.

Tumor necrosis factor alpha activation of the apoptotic cascade in murine articular chondrocytes is associated with the induction of metalloproteinases and specific pro-resorptive factors.

OBJECTIVE: Tumor necrosis factor alpha (TNFalpha) blockade provides substantive reduction of the symptoms of rheumatoid arthritis (RA). While the biologic actions of TNFalpha have been well characterized in immune and synovial cells, which are known to be major contributors to the progression of cartilage destruction in RA, the current studies were designed to assess the direct effects of TNFalpha on chondrocytes. METHODS: We examined the expression of several groupings of messenger RNA (mRNA) that define key biologic pathways that have previously been associated with either the general actions of TNFalpha or cartilage destruction, in murine articular chondrocytes isolated from wild-type mice and TNFalpha receptor-null (p55/p75(-/-)) mice. RESULTS: TNFalpha induced the expression of multiple mRNA that facilitate apoptosis and lead to apoptosis-induced cell death. The induction of apoptosis was accompanied by the increased expression of several factors involved in the regulation of skeletal tissue proteolysis and resorption. Quantitative increases from 2-fold to >10-fold were seen for inducible nitric oxide synthase, matrix metalloproteinase 3, macrophage colony-stimulating factor, and osteoprotegerin mRNA expression. The dependence of the induction of these mRNA on TNFalpha was confirmed by comparison with the effects of TNFalpha on chondrocytes isolated from receptor-null mice. CONCLUSION: These findings demonstrate that TNFalpha alters the expression of a complex array of genes within murine chondrocytes that contribute to the destruction of joint surfaces, independent of its actions on synovial and immune cells. Further studies are needed to clarify the biologic actions of TNFalpha in human cartilage cells.