Technical Errors May Affect Accuracy of Torque Limiter in Locking Plate Osteosynthesis.

In locking plate osteosynthesis, proper surgical technique is crucial in reducing potential pitfalls, and use of a torque limiter makes it possible to control insertion torque. We conducted a study of the ways in which different techniques can alter the accuracy of torque limiters. We tested 22 torque limiters (1.5 Nm) for accuracy using hand and power tools under different rotational scenarios: hand power at low and high velocity and drill power at low and high velocity. We recorded the maximum torque reached after each torque-limiting event. Use of torque limiters under hand power at low velocity and high velocity resulted in significantly (P < .0001) different mean (SD) measurements: 1.49 (0.15) Nm and 3.73 (0.79) Nm. Use under drill power at controlled low velocity and at high velocity also resulted in significantly (P < .0001) different mean (SD) measurements: 1.47 (0.14) Nm and 5.37 (0.90) Nm. Maximum single measurement obtained was 9.0 Nm using drill power at high velocity. Locking screw insertion with improper technique may result in higher than expected torque and subsequent complications. For torque limiters, the most reliable technique involves hand power at slow velocity or drill power with careful control of insertion speed until 1 torque-limiting event occurs.

Long-Term Results of Total Hip Arthroplasty with 28-Millimeter Cobalt-Chromium Femoral Heads on Highly Cross-Linked Polyethylene in Patients 50 Years and Less.

Highly cross-linked polyethylene (HXLPE) is the most commonly used bearing surface in total hip arthroplasty (THA) because of its superior wear properties, but long-term results in young patients are limited. We report on the clinical outcome, radiographic wear patterns and survivorship of 72 patients ≤50 years old who had a 28-millimeter cobalt-chromium femoral head on HXLPE acetabular liner. Mean and median true linear wear rates at average ten-year follow-up were 0.0104 and 0.01 mm per year ± 0.07 mm. Mean and median two-dimensional volumetric wear rates were 12.79 mm(3) and 5.834 mm(3) per year ± 26.1mm(3) as determined by Martell analysis. As a result of the minimal wear profile, there was no evidence of radiographic osteolysis and no wear-related revisions.

Perioperative differences in conventional and computer-assisted surgery in bilateral total knee arthroplasty.

Performing bilateral total knee arthroplasties (bTKAs), sequential or staged, is a topic of debate among surgeons. To our knowledge, no studies have compared computer-assisted surgery (CAS) and conventional (CON) procedures for sequential bTKAs. We retrospectively reviewed 124 (62 CAS, 62 CON) sequential bTKAs. CAS-bTKAs required significantly fewer blood transfusions (P = .001) and had significantly better postoperative day 1 (POD-1) hemoglobin (Hgb) levels (P = .001) and POD-2 Hgb levels (P = .01). Mean total blood transfusion units were 0.9 for the CAS group and 1.7 for the CON group. Postoperative range of motion, tourniquet time, length of stay, number of readmissions, and number of reoperations were not significantly different (P > .05). The statistically significant differences between the groups may have resulted from violation of the femoral intramedullary canal during the CON technique.