Anterior Cruciate Ligament Reconstruction Alone Versus With Lateral Extra-articular Tenodesis With Minimum 2-Year Follow-up: A Meta-analysis and Systematic Review of Randomized Controlled Trials.

BACKGROUND: Lateral extra-articular tenodesis (LEAT) aims to improve anterolateral stability of the injured knee during anterior cruciate ligament reconstruction (ACLR) surgery. Inconclusive evidence surrounding the efficacy and safety of LEAT has propelled clinical interest and ongoing discussions. PURPOSE: To establish level 1 evidence by assessing randomized controlled trials (RCTs) with minimum 2-year follow-up that directly compared ACLR with LEAT (LEAT group) and ACLR alone (non-LEAT group) in terms of clinical outcomes and complications. STUDY DESIGN: Meta-analysis and systematic review; Level of evidence, 1. METHODS: Meta-analysis was performed with a multidatabase search (Cochrane, EMBASE, OVID Medline, PubMed, and Web of Science) according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines on September 9, 2020. Data from published RCTs meeting inclusion criteria were extracted and analyzed with an inverse variance statistical model. RESULTS: A total of 7 RCTs were included, consisting of 517 LEAT and 589 non-LEAT patients. Only autografts were used for ACLR and LEAT. A variety of LEAT techniques and autograft fixation methods were used. We found improved stability (residual positive pivot shift: risk ratio [RR], 0.59; 95% CI, 0.39-0.88; P = .01) and better clinical outcomes (International Knee Documentation Committee [IKDC] score: mean difference [MD], 2.31; 95% CI, 0.54-4.09; P = .01; and Lysholm score: MD, 2.71; 95% CI, 0.68-4.75; P = .009) in the LEAT than non-LEAT group. Graft rerupture rate was 3 times less likely (RR, 0.31; 95% CI, 0.17-0.58; P < .001) in the LEAT group than the non-LEAT group. CONCLUSION: Good-quality evidence is available to support the efficacy of LEAT in improving anterolateral knee stability and reducing graft reruptures in primary ACLR. LEAT should be considered in patients with high risk factors. Although Lysholm and IKDC scores were statistically better in the LEAT group, these are unlikely to be clinically significant. Future studies should aim to identify patient populations that would best benefit from LEAT with ACLR.

Broadband fiber-based entangled photon-pair source at telecom O-band.

In this Letter, we report a polarization-entangled photon-pair source based on type-II spontaneous parametric downconversion at telecom O-band in periodically poled silica fiber (PPSF). The photon-pair source exhibits more than 130 nm (∼24THz) emission bandwidth centered at 1306.6 nm. The broad emission spectrum results in a short biphoton correlation time, and we experimentally demonstrate a Hong-Ou-Mandel interference dip with a full width of 26.6 fs at half-maximum. Owing to the low birefringence of the PPSF, the biphotons generated from type-II SPDC are polarization-entangled over the entire emission bandwidth, with a measured fidelity to a maximally entangled state greater than 95.4%. The biphoton source provides the broadest bandwidth entangled biphotons at O-band to our knowledge.

Dispersion measurement assisted by a stimulated parametric process.

Dispersion plays a major role in the behavior of light inside photonic devices. Current state-of-the-art dispersion measurement techniques utilize linear interferometers that can be applied to devices with small dispersion-length products. However, linear interferometry often requires beam alignment and phase stabilization. Recently, common-path nonlinear interferometers in the spontaneous regime have been used to demonstrate alignment-free and phase-stable dispersion measurements. However, they require single-photon detectors, resulting in high system cost and long integration times. We overcome these issues by utilizing a nonlinear interferometer in the stimulated regime and demonstrate the ability to measure the dispersion of a device with a dispersion-length product as small as 0.009 ps/nm at a precision of 0.0002 ps/nm. Moreover, this regime allows us to measure dispersion with shorter integration times (in comparison to the spontaneous regime) and conventional optical components and detectors.

Alignment-free dispersion measurement with interfering biphotons.

Measuring the dispersion of photonic devices with small dispersion-length products is challenging due to the phase-sensitive and alignment-intensive nature of conventional methods. In this Letter, we demonstrate a quantum technique to extract the second- and third-order chromatic dispersion of a short single-mode fiber using a fiber-based quantum nonlinear interferometer. The interferometer consists of two cascaded fiber-based biphoton sources, with each source acting as a nonlinear beam splitter. A fiber under test is placed between these two sources and introduces a frequency-dependent phase that is imprinted on the biphoton spectrum (interferogram) at the output of the interferometer. This interferogram contains the dispersion properties of the test fiber. Our technique has three novel features: (1) the broadband nature of the biphoton sources used in our setup allows accurate dispersion measurements on test devices with small dispersion-length products; (2) our all-fiber common-path interferometer requires no beam alignment or phase stabilization; and (3) multiple phase-matching processes supported in our biphoton sources enable dispersion measurements at different wavelengths, which yields the third-order dispersion achieved for the first time, to the best of our knowledge, using a quantum optical technique.

Compensation-free broadband entangled photon pair sources.

Quantum sources that provide broadband biphotons entangled in both polarization and time-energy degrees of freedom are a rich quantum resource that finds many applications in quantum communication, sensing, and metrology. Creating such a source while maintaining high entanglement quality over a broad spectral range is a challenge, which conventionally requires various compensation steps to erase temporal, spectral, or spatial distinguishabilities. Here, we point out that in fact compensation is not always necessary. The key to generate broadband polarization-entangled biphotons via type-II spontaneous parametric downcoversion (SPDC) without compensation is to use nonlinear materials with sufficiently low group birefringence that the biphoton bandwidth becomes dispersion-limited. Most nonlinear crystals or waveguides cannot meet this condition, but it is easily met in fiber-based systems. We reveal the interplay of group birefringence and dispersion on SPDC bandwidth and polarization entanglement quality. We show that periodically poled silica fiber (PPSF) is an ideal medium to generate high-concurrence (>0.977) polarization-entangled photons over a broad spectral range (>77nm), directly and without compensation. This is the highest polarization-entanglement concurrence reported that is maintained over a broad spectral range from a compensation-free source.

Subtalar fusion for pes valgus in cerebral palsy: results of a modified technique in the setting of single event multilevel surgery.

BACKGROUND: We studied the use of cortico-cancellous circular allograft combined with cannulated screw fixation for the correction of dorsolateral peritalar subluxation in a series of children with bilateral spastic cerebral palsy undergoing single event multilevel surgery. METHODS: Forty-six children who underwent bilateral subtalar fusion between January 1999 and December 2004 were retrospectively reviewed. Gait laboratory records, Gross Motor Function Classification System (GMFCS) levels, Functional Mobility Scale (FMS) scores, and radiographs were reviewed. The surgical technique used an Ollier type incision with a precut cortico-cancellous allograft press-fit into the prepared sinus tarsi. One or two 7.3 mm fully threaded cancellous screws were used to fix the subtalar joint. Radiographic analysis included preoperative and postoperative standing lateral radiographs measuring the lateral talocalcaneal angle, lateral talo-first metatarsal angle, and navicular cuboid overlap. Fusion rate was assessed with radiographs >12 months after surgery. RESULTS: The mean patient age was 12.9 years (range, 7.8 to 18.4 y) with an average follow-up of 55 months. Statistically significant improvement postoperatively was found for all 3 radiographic indices: lateral talocalcaneal angle, mean improvement 20 degrees (95% CI, 17.5-22.1; P<0.001); lateral talo-first metatarsal angle, mean improvement 21 degrees (95% CI, 19.2-23.4; P<0.001); and navicular cuboid overlap, mean improvement 29% (95% CI, 25.7%-32.6%; P<0.001). FMS improved across all patients, with Gross Motor Function Classification System III children experiencing a 70% improvement across all 3 FMS distances (5, 50, and 500 m). All 3 radiographic measures improved significantly (P<0.001). Fusion was achieved in 45 patients and there were no wound complications. CONCLUSIONS: With this study, we demonstrate significant improvement in radiographic segmental alignment and overall function outcome with this modified subtalar fusion technique. We conclude that this technique is an effective complement for children with dorsolateral peritalar subluxation undergoing single event multilevel surgery. LEVEL OF EVIDENCE: Level IV.

Sterile stockinette in orthopaedic surgery: a possible pathway for infection.

BACKGROUND: The prevention of infection in joint replacement surgery is important. Preparing and draping the patient is fundamental to maintaining sterility of the operative field. One method of draping for total knee replacement (TKR) surgery involves cleaning the operative leg with antiseptic wash then covering the un-prepped foot with a sterile stockinette to sequester the foot from the sterile field. There are two main methods for applying this stockinette. This randomized, blinded control trial simulates stockinette application to assess if it prevents proximal microbial migration into the sterile field. METHOD: To simulate microbial presence, ultraviolet fluorescent powder Glitterbug Powder™ (Arrow Scientific Pty Ltd, Lane Cove, NSW, Australia) was applied to volunteers' feet to the level where antiseptic wash would routinely stop during preparation. The stockinette was applied. Two methods of application (above and below knee) and two surgeons were used. These were randomized for each application. The drapes were removed and a blinded assistant measured the distance of proximal spread of Glitterbug Powder™. RESULTS: Both methods of application were associated with considerable proximal spread of Glitterbug Powder™. For the below knee method, mean proximal spread distance of 49.19%; for the above knee, mean of 71.8% proximal spread (P = 0.038). Multivariate linear regression analysis demonstrated that method and location of the contamination were predictive of the area of contamination and the percentage of the leg contaminated. No other factors (surgeon, gender, hirsute score) were predictive of either area or percentage contamination. CONCLUSION: The surgical field for TKRs may be contaminated by significant proximal microbial spread from the unprepared foot with the use of a sterile stockinette drape.

Single-level/single-stage debridement and posterior instrumented fusion in the treatment of spontaneous pyogenic osteomyelitis/discitis: long-term functional outcome and health-related quality of life.

STUDY DESIGN: Retrospective study. OBJECTIVE: To support single-level posterior debridement and instrumented interbody fusion as a single-stage procedure for spontaneous pyogenic osteomyelitis/discitis. SUMMARY OF BACKGROUND DATA: The best surgical technique for patients with bacterial spinal infections is still a matter of debate. Recent publications suggest that titanium implants can be used safely in the infectious sites in combination with debridement and antibiotic therapy. METHODS: We retrospectively review patients with spontaneous pyogenic osteomyelitis/discitis in whom medical therapy failed, and they consequently underwent posterior decompression and instrumented fusion. Data was collected regarding demographics, clinical presentation, images and laboratory studies, antibiotic treatment, duration of hospitalization, time to achieve radiologic evidence of fusion, postoperative complications, and neurologic function pre- and postoperatively. Quality of life was measured using the EQ5D questionnaire and level of disability with the Oswestry Disability Index. RESULTS: Nine patients, ranging in age from 41 to79 years, with a Frankel score of D in 7 cases and of E in 2 cases, underwent a single-level/single-stage debridement and posterior instrumented fusion with pedicle screws and an interbody and posterolateral autogenous bone graft. Preoperative neurologic deficits improved in all the cases and solid bone fusion was achieved in all 9 patients at 12 months. The mean follow-up period was 67 months. The infection healed after surgery in all the patients and they did not require a second operation to remove the metal implants. Quality of life assessed with the EQ5D questionnaire showed scores ranging between 0.70 and 1. The median Oswestry Disability Index was 15.5%. CONCLUSIONS: These findings support that debridement and posterior instrumented fusion can be performed as a single-stage procedure with no increase in the recurrence rate or morbidity. The outcome has been satisfactory in our patients in terms of the rate of fusion and quality of life.