Retroverting Periacetabular Osteotomy for Symptomatic Acetabular Anteversion.

BACKGROUND: Acetabular dysplasia has traditionally been defined using the lateral center edge angle and treated with periacetabular osteotomy (PAO). However, the recently described Ottawa classification further quantifies dysplasia in 3-dimensional terms, categorizing Ottawa A as dysplasia due to isolated, excessive acetabular anteversion or anterior acetabular under-coverage. We sought to determine if patients who have Ottawa A dysplasia can expect similar outcomes when undergoing a PAO compared to a traditional dysplasia cohort. METHODS: Patients who had undergone PAO with Ottawa A hip dysplasia were selected and compared to a control group of patients who had lateral acetabular undercoverage. The modified Harris Hip Score and International Hip Outcome Tool-33 were collected preoperatively and at various follow-up points for a final follow-up average of 2.3 years (range, 0.9 to 6.2). RESULTS: The 17 patients (21 hips) who had Ottawa A dysplasia were compared to a control cohort of 69 patients (88 hips). Both groups saw significant improvements in modified Harris Hip Score and International Hip Outcome Tool-33 at final follow-up, P < .001. There were no differences between groups in any of the outcome measures or rates of achieving minimal clinically important difference (MCID) or substantial clinical benefit. Rates of MCID ranged from 82.4 to 100%, and rates of achieving substantial clinical benefit ranged from 47.1 to 52.9%. CONCLUSIONS: In patients undergoing a PAO for Ottawa A hip dysplasia, a significant improvement in patient-reported outcomes can be expected with high rates of MCID achievement. This is not significantly different for patients undergoing PAO for more traditional dysplasia parameters.

Prolonged non-weightbearing treatment decreases femoral head deformity compared to symptomatic treatment in the initial stage of Legg-Calvé-Perthes disease.

The purpose of this study is to investigate the potential benefit of using prolonged non-weightbearing (PNWB) as a treatment option for early-stage Legg-Calvé-Perthes disease (LCPD). An Institutional Review Board (IRB) approved this retrospective study of patients with LCPD and ≥2-year follow-up. Patients 6-12 years of age were included if treatment began in Waldenstrom stage 1 or 2A. PNWB consisted of ≥6 months of non- or toe-touch weightbearing. PNWB was recommended if perfusion MRI demonstrated ≥40% hypoperfusion of the femoral head and parents decided against operative treatment. The control group consisted of symptomatically treated patients. Deformity index and epiphyseal quotient were measured at 2-year follow-up. Stulberg classification and sphericity deviation score (SDS) were determined at skeletal maturity or at a minimum of 5-year follow-up. When treatment was initiated in Waldenstrom stage 1, the PNWB group had significantly less femoral head deformity, including deformity index (0.21 vs. 0.52; P < 0.001), epiphyseal quotient (69% vs. 43%; P < 0.001), SDS (18 vs. 52; P = 0.004), and Stulberg (50% good vs. 0% good; P = 0.044). The PNWB group mean hypoperfusion was 68%, indicating severe hypoperfusion. Duration of recommended non-weight bearing in the PNWB group was 11.5 months (range 7-17 months). Despite severe femoral head hypoperfusion, PNWB begun during the initial stage of LCPD decreased femoral head deformity. PNWB should be considered a treatment option for patients/parents who do not wish to pursue operative intervention in early-stage LCPD with substantial hypoperfusion. Level of Evidence III - retrospective comparative study.

Frontal Crash Injury Metrics Are Below Mandated Limits for a Spica Casted Child Dummy in Currently Available Restraints.

BACKGROUND: There is a paucity of data defining safe transport protocols for children treated with hip spica casting. Although restraint devices for casted children are available, all federally mandated testing uses a noncasted anthropomorphic test device (ATD or crash dummy). The purpose of this study was to evaluate current restraint options in simulated frontal crash testing using a casted pediatric ATD to determine injury risk to the head, cervical spine, chest, and pelvis. METHODS: Using a 3-year-old ATD, dynamic crash sled tests simulating frontal crash were performed in accordance with government safety standards. The ATD was casted in a double-leg spica and the following restraint devices were tested: a seat designed for spica casted children, a restraint vest-harness, a traditional booster seat, and 2 traditional forward-facing car seats. RESULTS: Although the presence of the cast increased many of the injury metrics measured, all seats passed current federal guidelines for the head and chest. No single seat performed best in all metrics. The greatest magnitude of neck loading and second-highest head injury criterion values were observed for the booster seat. The vest-harness produced the highest head injury criterion and the chest compression exceeded proposed federal limits. CONCLUSIONS: The results suggest safe transport in commercially available seats is possible with the child properly restrained in a correctly fitting seat. However, parents should not assume a child restraint system is appropriate for use just based on fit as, for example, seats with harnesses outperformed an easy to fit booster seat. CLINICAL RELEVANCE: Each child and the position of the child's cast are unique and discharge planning involves consideration of safe transportation. Although this study suggests several seats used to transport spica casted children pass the federal head and chest injury prevention requirements, it is important to recognize that some children may still require emergency vehicle transport.

The Flint Lock: A Novel Technique in Total Knee Arthroplasty Closure.

Conventional interrupted sutures are traditionally used in extensor mechanism closure during total knee arthroplasty (TKA). In recent years, barbed suture has been introduced with the proposed benefits of decreased closure time and a watertight seal that is superior to interrupted sutures. Complication rates using barbed sutures and conventional interrupted sutures are similar. We propose a novel closure technique known as the Flint Lock, which is a double continuous interlocking stitch. The Flint Lock provides a quick and efficient closure to the extensor mechanism in TKA. In addition, similar to barbed suture, the Flint Lock should provide a superior watertight seal. It utilizes relatively inexpensive and readily available materials.

Optimizing Hybrid Plate Fixation with a Locked, Oblique End Screw in Osteoporotic Fractures.

BACKGROUND: The end screw in a fracture plate creates the greatest resistance to bending. For osteoporotic fractures treated with plates, there is some question as to the optimal screw insertion technique for the screw farthest from the fracture. A locked, oblique end screw was previously shown to increase resistance to periprosthetic fracture. It is unknown, however, how this end screw configuration would resist pullout when subjected to bending. METHODS: Narrow, low contact 3.5 mm locking compression plates with 6 and 12 holes were anchored to simulated bone material with material properties representing osteoporotic bone. Four configurations were evaluated for the end screw: perpendicular and angulated 30 degrees away from the fracture for both non-locked and locked screws (n=6 per group). The constructs were subjected to 3 point bending until the peak load and finally total construct failure was achieved. RESULTS: Peak force, stiffness, energy to peak load, and the failure mode of each construct were determined. All four 12-hole construct groups failed by gross plastic bending deformation of the plate at the fulcrum past a previously established clinically relevant limit for failure (15°). All 12-hole plate constructs failed at statistically higher loads and energy than any of the 6-hole plate constructs, with the exception of the 6-hole locked, oblique construct. CONCLUSION: The locked, oblique end screw provides equivalent pull out strength for 3.5 mm low contact plates regardless of plate length. Combined with its resistance to periprosthetic fracture, this end screw configuration appears to be the best option for the construct integrity of hybrid plating for osteoporotic fractures. CLINICAL RELEVANCE: Osteoporotic fractures are challenging to treat. The current study and the existing literature show that resistance to both bending loads and refracture at the end of a plate are minimized with a locked screw angled away from the fracture.

Reducing Fracture Risk Adjacent to a Plate With an Angulated Locked End Screw.

OBJECTIVES: Locking screws often are used in the treatment of osteoporotic fractures. Studies show that locking screws can increase bone stresses at the plate end, which increases the possibility of peri-implant fracture. This study evaluates whether the technique used to insert the end screw is related to the fracture tolerance adjacent to the plate. METHODS: Twelve groups of plate constructs were evaluated using a fibular diaphyseal surrogate with mechanical properties similar to osteoporotic bone. All inboard screws were nonlocked with only the end screw fixation differing among groups. The end screws were inserted either perpendicularly to the plate or at an angle of 30 degrees for 6- and 12-hole plates. For both orientations, the end screws were inserted nonlocked, locked, or by a locked overdrilling technique, resulting in 6 groups per plate length. The perpendicular nonlocked screws represented a control group. The constructs were tested to failure in 4-point bending to determine peak load, failure energy, and stiffness. RESULTS: All constructs failed by peri-implant fracture along a plane through the 2 cortical holes of the end screw. Compared with the control group, an angulated locked screw at the plate end significantly increased the peak bending moment and energy required to produce a fracture for both plate lengths (6-hole, P = 0.008, P < 0.001; 12-hole, P = 0.006, P < 0.001). CONCLUSIONS: The use of an angulated locked end screw may enhance the resistance of osteoporotic bone to peri-implant fractures caused by bending forces.