Serum and Wound Vancomycin Levels After Intrawound Administration in Primary Total Joint Arthroplasty.

BACKGROUND: Periprosthetic joint infection is the most common cause of readmissions after total joint arthroplasty (TJA). Intrawound vancomycin powder (VP) has reduced infection rates in spine surgery; however, there are no data regarding VP in primary TJA. METHODS: Thirty-four TJA patients received 2 g of VP intraoperatively to investigate VP's pharmacokinetics. Serum and wound concentrations were measured at multiple intervals over 24 hours after closure. RESULTS: All serum concentrations were subtherapeutic (<15µg/mL) and peaked 12 hours after closure (4.7µg/mL; standard deviation [SD], 3.2). Wound concentrations were 922 µg/mL (SD, 523) 3 hours after closure and 207 µg/mL (SD, 317) at 24 hours. VP had a half-life of 7.2 hours (95% confidence interval, 7.0-9.3) in TJA wounds. CONCLUSIONS: VP produced highly therapeutic intrawound concentrations while yielding low systemic levels in TJA. VP may serve as a safe adjunct in the prevention of periprosthetic joint infection.

Identification of a Novel Mycoplasma Species in a Patient With Septic Arthritis of the Hip and Seal Finger.

An Alaska Native hunter developed fever, swollen finger, and septic hips after harvesting seals. Evaluation of hip tissue by 16S rRNA gene polymerase chain reaction and sequencing revealed a putative novel mycoplasma species. We report the identification of this organism and describe the first known case of disseminated seal finger mycoplasmosis.

Do Lordotic Cages Provide Better Segmental Lordosis Versus Nonlordotic Cages in Lateral Lumbar Interbody Fusion (LLIF)?

STUDY DESIGN: A retrospective comparative radiographic review. OBJECTIVE: To evaluate the radiographic changes brought about by lordotic and nonlordotic cages on segmental and regional lumbar sagittal alignment and disk height in lateral lumbar interbody fusion (LLIF). SUMMARY OF BACKGROUND DATA: The effects of cage design on operative level segmental lordosis in posterior interbody fusion procedures have been reported. However, there are no studies comparing the effect of sagittal implant geometry in LLIF. METHODS: This is a comparative radiographic analysis of consecutive LLIF procedures performed with use of lordotic and nonlordotic interbody cages. Forty patients (61 levels) underwent LLIF. Average age was 57 years (range, 30-83 y). Ten-degree lordotic PEEK cages were used at 31 lumbar interbody levels, and nonlordotic cages were used at 30 levels. The following parameters were measured on preoperative and postoperative radiographs: segmental lordosis; anterior and posterior disk heights at operative level; segmental lordosis at supra-level and subjacent level; and overall lumbar (L1-S1) lordosis. Measurement changes for each cage group were compared using paired t test analysis. RESULTS: The use of lordotic cages in LLIF resulted in a significant increase in lordosis at operative levels (2.8 degrees; P=0.01), whereas nonlordotic cages did not (0.6 degrees; P=0.71) when compared with preoperative segmental lordosis. Anterior and posterior disk heights were significantly increased in both groups (P<0.01). Neither cage group showed significant change in overall lumbar lordosis (lordotic P=0.86 vs. nonlordotic P=0.25). CONCLUSIONS: Lordotic cages provided significant increase in operative level segmental lordosis compared with nonlordotic cages although overall lumbar lordosis remained unchanged. Anterior and posterior disk heights were significantly increased by both cages, providing basis for indirect spinal decompression.

Radiographic Comparison of Lateral Lumbar Interbody Fusion Versus Traditional Fusion Approaches: Analysis of Sagittal Contour Change.

BACKGROUND: Lateral approach to lumbar fusion has been gaining popularity in recent years. With increasing awareness of the significance of sagittal balance restoration in spinal surgery, it is important to investigate the potential of this relatively new approach in correcting sagittal deformities in comparison to conventional approaches. The aim of this study was to evaluate sagittal contour changes seen in lateral lumbar interbody fusion and compare them with radiographic changes in traditional approaches to lumbar fusion. METHODS: Lumbar fusion procedures from January 2008 to December 2009 were reviewed. Four approaches were compared: anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), transforaminal interbody fusion (TLIF) and posterior spinal fusion (PSF). Standing pre-operative and 6-week post-operative radiographs were measured in terms of operative level, suprajacent and subjacent level, and regional lumbar lordosis (L1-S1) as well as operative level anterior (ADH) and posterior disc heights (PDH). T-test was used to analyze differences between and within different approaches (α=0.05). RESULTS: A total of 147 patients underwent lumbar fusion at 212 levels. Mean operative level segmental lordosis change after each procedure is as follows: ALIF 3.8 ± 6.6° (p < 0.01); LLIF 3.2 ± 3.6° (p<0.01); TLIF 1.9 ± 3.9° (p<0.01); and PSF 0.7 ± 2.9° (p =0.13). Overall lumbar lordosis change after each procedure is as follows: ALIF 4.2 ± 5.8° (p < 0.01); LLIF 2.5 ± 4.1° (p<0.01); TLIF 2.1 ± 6.0 (p = 0.02); PSF -0.5 ± 6.2° (p = 0.66). There were no significant changes in the supradjcent and subjacent level lordosis in all approaches except in ALIF where a significant decrease in supradjecent level lordosis was seen. Mean ADH and PDH significantly increased for all approaches except in PSF where PDH decreased post-operatively. CONCLUSION: LLIF has the ability to improve sagittal contour as well as other interbody approaches and is superior to posterioronly approach in disc height restoration. However, ALIF provides the greatest amount of segmental and overall lumbar lordosis correction. LEVEL OF EVIDENCE: This is a Level III study. CLINICAL RELEVANCE: Regional lordosis correction may be effectively achieved with LLIF. This approach is a good addition to a surgeon's armamentarium in maintenance or restoration of normal lumbar sagittal alignment.