Prevalence and Risk Factors for Lateral Femoral Cutaneous Nerve Palsy in the Beach Chair Position.

PURPOSE: To report on the prevalence of lateral femoral cutaneous nerve (LFCN) palsy in patients who had undergone shoulder surgery in the beach chair position and to identify patient and surgical risk factors for its development. METHODS: We retrospectively reviewed the medical records of 397 consecutive patients who underwent either open or arthroscopic shoulder surgery in the beach chair position by a single surgeon. Patient demographic and surgical data including age, gender, weight, body mass index (BMI), diabetes, procedure duration, and anesthesia type (general, regional, regional/general) were recorded. LFCN palsy symptoms were recorded prospectively at the initial postoperative visit and identified clinically by focal pain, numbness, and/or tingling over the anterolateral thigh. RESULTS: The median patient age was 59.0 years and consisted of 158 males (40%) and 239 (60%) females. Five cases of LFCN palsy were identified for a prevalence of 1.3%. These patients had a higher median weight (108.9 kg vs 80.7 kg, P = .005) and BMI (39.6 vs 29.4, P = .005) than the patients who did not develop LFCN palsy. Median age, gender, diabetes, and surgical time were not significantly different between the groups. All cases resolved completely within 6 months. CONCLUSIONS: LFCN palsy after shoulder surgery in the beach chair position in our study has a prevalence of 1.3%, making it an uncommon complication. Patients with elevated BMI should be counseled about its possible occurrence after shoulder surgery in the beach chair position. LEVEL OF EVIDENCE: Level IV, prognostic.

The Science of Quality Improvement.

The manufacturing industry has supplied many quality-improvement methodologies that have been successfully utilized in health-care delivery, such as Plan-Do-Study-Act (PDSA) cycles, Total Quality Management, Six Sigma, and Lean. Many tools of quality improvement, such as PDSA cycles and DMAIC (Design-Measure-Analyze-Improve-Control) of the Six Sigma method, are similar to the scientific method that is familiar to clinicians. Correct identification of the sources and types of process variation within a system is paramount for process improvement. Reduction in process variation via standardization and reinforcement of process protocols leads to improved process outcomes. Quality-improvement projects should define a clear governance structure to maintain project timeliness and completion.

Nonsurgical Treatment of Aseptic Periprosthetic Gout Flare of the Knee: A Report of 2 Cases.

CASE: Gout is a rarely reported cause of a painful knee following total knee arthroplasty, but it can mimic infection in its symptomatology and workup. Two individuals who had previously undergone a knee replacement and had a history of gout had symptoms of infection. These patients presented with knee warmth and effusion, and they had elevated inflammatory markers and synovial cell counts. In both cases, there was a good response to medication, and surgery was avoided. CONCLUSION: Although simultaneous infection can occur, aseptic periprosthetic gout should be considered in individuals with a known history of gout, in those with a good response to anti-gout medication, and when there is an otherwise negative workup for infection.

Plantar forces in flexor hallucis longus versus flexor digitorum longus transfer in adult acquired flatfoot deformity.

BACKGROUND: Flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon transfers are frequently used to restore the function of a deficient tibialis posterior tendon in stage II adult acquired flatfoot deformity (AAFD). Either transfer causes some loss in toe flexion force, although the decision to tenodese the cut tendon to restore associated function remains controversial. This study quantified changes in plantar force before and after tendon transfer and with or without distal tenodesis in a cadaveric model. METHODS: The plantar force distribution of 10 matched pairs of statically loaded cadaveric lower extremities was investigated. Each foot was tested when it was intact, after FDL/FHL tendon transfer, and after tendon transfer + tenodesis. RESULTS: Transfer of either FHL or FDL showed a statistically significant decrease in flexion force of the great toe (P < .01) and lesser toes (P < .001), respectively. Subsequent tenodesis in either tendon demonstrated an ability to restore flexion force in the great (P < .05) and lesser (P < .01) toes, respectively, with the FHL transfer + tenodesis restoring great toe loading to near pretransfer levels. Following either transfer, plantar force increased in the medial forefoot; this was sustained with FDL transfer + tenodesis but reduced under FHL transfer + tenodesis. Lateral forefoot force increased modestly (8%) with FHL transfer (P < .05) but returned to near intact levels with tenodesis. FDL transfer + tenodesis resulted in increased medial midfoot and heel loading. DISCUSSION: FHL or FDL transfer notably reduces associated toe flexion force. This loss can be restored to near normal levels with tenodesis for FHL transfer. As increased lateral forefoot loading is commonly associated with AAFD corrective procedures, FHL tenodesis may mitigate the unintended increases caused by the tendon transfer. The medial midfoot and heel loading with FDL transfer + tenodesis underscores that tendon transfers alone do not reestablish the passive architecture of the foot but augment deficient subtalar inversion force. CLINICAL RELEVANCE: This cadaveric study shows that the FHL is more biomechanically suitable for tibialis posterior tendon insufficiency than the FDL, which may be a basis for a study to investigate whether it is superior in a clinical situation.

Best practices for use of the HEMOX analyzer in the clinical laboratory: quality control determination and choice of anticoagulant.

The HEMOX Analyzer (TCS Scientific) has been used to measure the full oxygen-dissociation curve (ODC) and to calculate P(50) and the Hill coefficient. The effects of different anticoagulants on sample stability and P(50) values have not been evaluated extensively for this instrument. We characterized an artificial hemoglobin (Equil QC463) for quality control (QC) and compared P(50) values for blood samples drawn into 3 different anticoagulants (acid citrate dextrose [ACD], heparin, and EDTA). P(50) values were not stable in ACD but were stable in heparin and EDTA anticoagulants for up to 4 days. Tests with Equil QC463 showed that P(50) values were quite sensitive to small variations in buffer pH. Use of the correct anticoagulant and strict control of buffer pH are 2 parameters that need to be accounted for in best-practices use of this hemoximeter and before determining P(50).