Experimental periprosthetic fractures with collarless polished tapered cemented stems.

PURPOSE: After cemented total hip arthroplasty, the risk of periprosthetic fracture (PPF) of taper-slip stems is higher than that of composite-beam stems. We aimed to assess the conditions resulting in PPFs of taper-slip stems using a falling weight. METHODS: Taper-slip stems were fixed to five types of simulated bone models using bone cement, and the fractures were evaluated by dropping stainless-steel weights from a predetermined height onto the heads. The periprosthetic fracture height in 50% of the bone models (PPFH50) was calculated using the staircase method. RESULTS: For the fixation with 0° of flexion, the values for PPFH50 were 61 ± 11, 60 ± 13, above 110, 108 ± 49, and 78 ± 12 cm for the cobalt-chromium-molybdenum alloy, stainless steel alloy (SUS), titanium alloy (Ti), smooth surface, and thick cement mantle models, respectively; for the fixation with 10° of flexion (considering flexure), the PPFH50 values were 77 ± 5, 85 ± 9, 90 ± 2, 89 ± 5, and 81 ± 11 cm, respectively. The fracture rates of the polished-surface stems were 78.6 and 35.7% at the proximal and distal sites, respectively (p < 0.05); the fracture rates of the smooth-surface stems were 14.2 and 100%, respectively (p < 0.05). CONCLUSION: The impact tests demonstrated that the conditions that were less likely to cause PPFs were use of Ti, a smooth surface, a thick cement mantle, and probably, use of SUS.

Efficacy of the shoelace technique for extremity fasciotomy wounds due to compartment syndrome.

BACKGROUND: The shoelace technique for compartment syndrome allows application of sustained tightening tension to an entire wound and intermittent tightening of the shoelace without requiring its replacement or anesthesia. We retrospectively evaluated the usefulness of the shoelace technique in the management of extremity fasciotomy wounds before and after its introduction in our institution. METHODS: We targeted 25 patients who were diagnosed as having compartment syndrome and underwent extremity fasciotomy at our hospital from April 2012 to December 2021. The N group, comprising 12 patients treated without the shoelace technique, and the S group, comprising 13 patients treated with the shoelace technique, were compared retrospectively for each outcome. RESULTS: There were no significant differences between the two groups in patient background. Compared with the N group patients, all of the S group patients avoided skin grafting (S group: n = 0, 0%; N group: n = 6, 50.0%; p < 0.01). However, there was no significant difference in the number of days to final wound closure (S group: 39.5 [IQR 24.3-58.0] days; N group: 24.0 [IQR 18.5-31.0] days, p = 0.06). CONCLUSIONS: We considered the shoelace technique to be a useful wound closure method for fasciotomy wounds caused by compartment syndrome because it can significantly reduce the need for skin grafting and tends to shorten the wound closure period.

A Possible Protective Effect of the 'Cam Deformity' on Femoral Neck Fracture: The Relationship between Hip Morphology and the Types of Hip Fracture.

We retrospectively evaluated the cases of 169 hip fracture patients, their previous fractures, and the contralateral hip joint's morphology. A history of contralateral hip fracture was present in 23 patients (Contra group). The other patients had a unilateral hip fracture: a trochanteric fracture (Troch group, n=73) or a femoral neck fracture (Neck group, n=73). In the Troch and Neck groups, we used anteroposterior and cross-table axialview radiographs of the contralateral hip to evaluate the proximal femur's anatomy. In the Contra group, the concordance rate between the first and second types of hip fracture was 65.2%, and the second hip fracture's morphology indicated that the trochanteric fracture had a cam deformity in terms of the femoral head-neck ratio. The average alpha angle and femoral head-neck offset in the Troch group were significantly larger than those in the Neck group. In the Neck group, pistol-grip deformities of Arbeitsgemeinschaft für Osteosynthesefragen types B1 (subcapital), B2 (transcervical), and B3 (displaced) were observed in 42.1%, 75%, and 6% of cases, respectively. There was a smaller alpha angle and a larger femoral head-neck offset in the contralateral hip of femoral neck fractures; thus, the "cam deformity" may protect against femoral neck fractures.

A novel fixation method for panfacial fracture using an Ilizarov-type external fixator.

In general, internal plate fixation is mainly performed in order to reduce multiple facial bone fractures and rarely uses an external fixator. Although it would be ideal to successfully achieve or preserve the occlusal relationship of the upper and lower jaws, it is difficult to successfully manage multiple bone fragments in order to use them to achieve internal fixation, especially when treating a severely comminuted facial fracture. In addition, it is also important to prevent the onset of severe infection after sub-periosteal dissection, due to the presence of avascular bony fragments and an internal fixation implant which thus represents a foreign body. In order to treat extensive comminuted fracture without internal plate fixation, we performed external fixation using an Ilizarov-type external fixator. The Ilizarov-type external fixator is characterized by a few circular external structures and threaded rods. This device can be modified for use in the field of orthopedic surgery to correct three-dimensional deformities caused by fragile complicated fractures and bone defects. The advantages of the Ilizarov-type external fixator for treating panfacial fractures include a low invasiveness, utility in various fracture situations, easy adjustment of threaded rods, and a low potential cost. We herein report the first case of a severe panfacial fracture that was successfully treated using an Ilizarov-type external fixator.