Clinical Relevance of Sensory Nerve Coaptation in DIEP Flap Breast Reconstruction Evaluated Using the BREAST-Q.

BACKGROUND: Sensory nerve coaptation in autologous breast reconstruction positively affects sensory recovery in the reconstructed breast. However, patient-reported outcomes are lacking and no conclusions on the clinical relevance of nerve coaptation could be drawn. The aim of this study was to evaluate the clinical relevance of nerve coaptation in deep inferior epigastric perforator (DIEP) flap breast reconstruction. METHODS: A prospective cohort study was conducted of patients undergoing innervated or noninnervated DIEP flap breast reconstruction between August of 2016 and August of 2018. Patients completed a BREAST-Q questionnaire at a minimum of 12 months' follow-up in combination with either a preoperative questionnaire or a questionnaire at 6 months' follow-up. The physical well-being of the chest domain was the primary outcome and patients answered additional sensation-specific questions. Sensation was measured using Semmes-Weinstein monofilaments. RESULTS: In total, 120 patients were included (65 innervated and 55 noninnervated reconstructions). A clinically relevant difference was found in BREAST-Q scores in favor of patients with innervated reconstructions in general and for delayed reconstructions specifically. Patients with sensate breast reconstruction more often reported better and pleasant sensation. CONCLUSIONS: This study demonstrated that nerve coaptation in DIEP flap breast reconstruction, specifically in delayed reconstruction, resulted in clinically relevant improved patient-reported outcomes on the physical well-being of the chest domain of the BREAST-Q and that better sensation was perceived. However, the BREAST-Q does not address sensation adequately, and the introduction and validation of new scales is required to confirm the clinical relevance of nerve coaptation reliably. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Innervation of the Female Breast and Nipple: A Systematic Review and Meta-Analysis of Anatomical Dissection Studies.

BACKGROUND: Primary cadaveric studies were reviewed to give a contemporary overview of what is known about innervation of the female breast and nipple/nipple-areola complex. METHODS: The authors performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review and meta-analysis. The authors searched four electronic databases for studies investigating which nerve branches supply the female breast and nipple/nipple-areola complex or describing the trajectory and other anatomical features of these nerves. Inclusion criteria for meta-analysis were at least five studies of known sample size and with numerical observed values. Pooled prevalence estimates of nerve branches supplying the nipple/nipple-areola complex were calculated using random-effects meta-analyses; the remaining results were structured using qualitative synthesis. Risk of bias within individual studies was assessed with the Anatomical Quality Assurance checklist. RESULTS: Of 3653 studies identified, 19 were eligible for qualitative synthesis and seven for meta-analysis. The breast skin is innervated by anterior cutaneous branches and lateral cutaneous branches of the second through sixth and the nipple/nipple-areola complex primarily by anterior cutaneous branches and lateral cutaneous branches of the third through fifth intercostal nerves. The anterior cutaneous branch and lateral cutaneous branch of the fourth intercostal nerve supply the largest surface area of the breast skin and nipple/nipple-areola complex. The lateral cutaneous branch of the fourth intercostal nerve is the most consistent contributory nerve to the nipple/nipple-areola complex (pooled prevalence, 89.0 percent; 95 percent CI, 0.80 to 0.94). CONCLUSIONS: The anterior cutaneous branch and lateral cutaneous branch of the fourth intercostal nerve are the most important nerves to spare or repair during reconstructive and cosmetic breast surgery. Future studies are required to elicit the course of dominant nerves through the breast tissue.

A morphometric analysis of pathological alterations in hemorrhoidal disease versus normal controls: a controlled trial

Objective: Until today, the true pathophysiology of hemorrhoidal disease (HD) has not yet been unraveled. More and more evidence guides us towards the hypothesis that reduced connective tissue stability is associated with a higher incidence of hemorrhoids. The present study aimed to compare the quantity and quality of collagen, and vessel morphometrics, in patients with symptomatic HD compared with normal controls. Methods: Twenty-two samples of grade III and grade IV HD tissue from patients undergoing a hemorrhoidectomy between January 2004 and June 2015 were included in the study group. Samples of 15 individuals without symptomatic HD who donated their body to science and died a natural death served as controls. The quantity and quality of anal collagen, and anal vessel morphometrics were objectified. The quality of collagen was subdivided in young (immature) and old (mature) collagen. Results: Patients with HD had an increased percentage of total anal collagen (62.1 ± 13.8 versus 18.7 ± 14.5%; p = 0.0001), a decreased percentage of young collagen (0.00009 ± 0.00008 versus 0.0008 ± 0.0008%; p = 0.001), and a smaller surface area of the anal vessels (795.1 ± 1215.9 micrometre2 versus 1219.0 ± 1976.1; p = 0.003) compared with controls. The percentage of old collagen did not differ between the control and study groups (0.588 ± 0.286% versus 0.389 ± 0.242%; p = 0.06). Conclusion: The outcomes of the present study suggest that alterations in anal collagen composition may play a role in the formation of hemorrhoids. (AU)

The innervation of the cervical facet joints-an anatomical and histological approach.

Cervical facet joint pain syndrome accounts for a great amount of cervical pain worldwide. This study aims to provide updated knowledge of cervical facet joint innervation with new anatomical findings. Twenty-seven cervical facet joints and their innervating structures were dissected from five halves of three human neck specimens. Histologic staining was used to confirm that the samples were nervous tissues, and all samples were documented with photography. Histology: Thirty-six assumed facet joint branch samples were obtained and stained. Twenty-two of these were confirmed to be nervous tissue. Therefore, 61% of the samples were identified as facet joint branches. Of all samples, 28% were not nerves. Dissection: At least one medial branch was clearly identified at each dissected cervical level. At some cervical levels, more than one medial branch was found. Anatomical differences, such as a plexus-like innervation in the high cervical region, were observed. Direct facet joint branches were also discovered. These branches originate directly from the dorsal root of the spinal nerve and were independent from medial branches during their direct pathway toward the facet joint. Direct cervical facet joint branches were identified and a more diverse innervation pattern than previously described of the cervical facet joints was found.

Nerve Coaptation Improves the Sensory Recovery of the Breast in DIEP Flap Breast Reconstruction.

BACKGROUND: Restoring the sensation of the reconstructed breast has increasingly become a goal of autologous breast reconstruction. The aim of this study was to analyze the sensory recovery of the breast and donor site of innervated compared to noninnervated deep inferior epigastric perforator (DIEP) flap breast reconstructions, to assess associated factors, and to compare the differences between preoperative and postoperative sensation. METHODS: A prospective cohort study was conducted, including patients who underwent innervated or noninnervated DIEP flap breast reconstruction between August of 2016 and August of 2018. Nerve coaptation was performed to the anterior cutaneous branch of the third intercostal nerve. Preoperative and postoperative sensory testing of the breast and donor site was performed with Semmes-Weinstein monofilaments. RESULTS: A total of 67 patients with 94 innervated DIEP flaps and 58 patients with 80 noninnervated DIEP flaps were included. Nerve coaptation was significantly associated with lower mean monofilament values for the breast (-0.48; p < 0.001), whereas no significant differences were found for the donor site (-0.16; p = 0.161) of innervated compared to noninnervated DIEP flaps. Factors positively or negatively associated with sensory recovery of the breast and donor site were identified. Preoperative versus postoperative comparison demonstrated significantly superior sensory recovery of the breast in innervated flaps (adjusted difference, -0.48; p = 0.017). CONCLUSIONS: This study demonstrated that nerve coaptation in DIEP flap breast reconstruction significantly improved the sensory recovery of the breast compared to noninnervated flaps. The sensory recovery of the donor site was not compromised in innervated reconstructions. The results support the role of nerve coaptation in autologous breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Mechanoreceptors observed in a ligamentous structure between the posterior horn of the lateral meniscus and the anterior cruciate ligament.

PURPOSE: A histological study of a structure between the posterior horn of the lateral meniscus and the anterior cruciate ligament. METHODS: Bilateral fresh-frozen cadaveric knees of two male donors (age 71 and 76 years) with no history of prior knee injury were examined. All dissections were performed by one experienced orthopaedic surgeon. Haematoxylin and Eosin staining was used to reveal tissue morphology. Goldner trichrome staining was used to evaluate the connective tissue. S100 and PGP 9.5 labelling were used for immunohistochemical analysis. RESULTS: In all cadaveric knees, a structure between the posterior horn of the lateral meniscus and the anterior cruciate ligament was identified. Histological analysis confirmed the ligamentous nature of this structure. Furthermore, Golgi tendon organs were observed within the ligamentous structure. CONCLUSION: This is the first study showing the presence of mechanoreceptors within the ligamentous structure between the posterior horn of the lateral meniscus and the anterior cruciate ligament. The ligamentous structure could contribute to stability of the knee by providing proprioceptive input, while preservation of the ligamentous structure might ensure a better functional outcome after surgery.

Sensory Recovery of the Breast following Innervated and Noninnervated Lateral Thigh Perforator Flap Breast Reconstruction.

BACKGROUND: The lateral thigh perforator flap, based on the tissue of the upper lateral thigh, is an excellent option for autologous breast reconstruction. The aim of this study was to introduce the technique to perform a nerve coaptation in lateral thigh perforator flap breast reconstruction and to analyze the results by comparing the sensory recovery of the reconstructed breast and donor site between innervated and noninnervated lateral thigh perforator flaps. METHODS: A prospective cohort study was conducted of patients who underwent an innervated or noninnervated lateral thigh perforator flap breast reconstruction between December of 2014 and August of 2018. Direct nerve coaptation was performed between a branch of the lateral femoral cutaneous nerve and the anterior cutaneous branch of the intercostal nerve. Sensory testing was performed with Semmes-Weinstein monofilaments to assess the sensation of the native skin, flap skin, and donor site during follow-up. RESULTS: In total, 24 patients with 37 innervated lateral thigh perforator flaps and 18 patients with 26 noninnervated lateral thigh perforator flaps were analyzed (median follow-up, 17 and 15 months, respectively). Significantly lower mean monofilament values were found for the native skin (adjusted difference, -0.83; p = 0.011) and flap skin (adjusted difference, -1.11; p < 0.001) of the reconstructed breast in innervated compared to noninnervated flaps. For the donor site, no statistically significant differences were found between both groups. CONCLUSIONS: Nerve coaptation in lateral thigh perforator flap breast reconstruction resulted in a significantly better sensory recovery of the reconstructed breast compared to noninnervated flaps. The data also suggest that harvesting a sensory nerve branch does not compromise the sensory recovery of the upper lateral thigh.

Breast sensibility in bilateral autologous breast reconstruction with unilateral sensory nerve coaptation.

BACKGROUND: Patient satisfaction after breast reconstruction is dependent on both esthetics and functional outcomes. In an attempt to improve breast sensibility, a sensory nerve coaptation can be performed. The aim of this study was to objectify the sensory recovery in patients who, by chance, underwent bilateral autologous breast reconstruction with one innervated and one non-innervated flap. It must be emphasized that the intention was to coaptate the sensory nerves on both sides. METHODS: The cohort study was carried out in the Maastricht University Medical Center between August 2016 and August 2018. Patients were eligible if they underwent bilateral non-complex, autologous breast reconstruction with unilateral sensory nerve coaptation and underwent sensory measurements using Semmes-Weinstein monofilaments at 12 months of follow-up. Sensory outcomes were compared using t tests. RESULTS: A total of 15 patients were included, all contributing one innervated and one non-innervated flap. All patients had a follow-up of at least 12 months, but were measured at different follow-up points with a mean follow-up of 19 months. Sensory nerve coaptation was significantly associated with better sensation in the innervated breasts and showed better sensory recovery over time, compared to non-innervated breasts. Moreover, the protective sensation of the skin can be restored by sensory nerve coaptation. CONCLUSIONS: The study demonstrated that sensory nerve coaptation leads to better sensation in the autologous reconstructed breast in patients who underwent bilateral breast reconstruction and, by chance, received unilateral sensory nerve coaptation.

Design of the ocular coil, a new device for non-invasive drug delivery.

Eye drops and ointments are the most prescribed methods for ocular drug delivery. However, due to low drug bioavailability, rapid drug elimination, and low patient compliance there is a need for improved ophthalmic drug delivery systems. This study provides insights into the design of a new drug delivery device that consists of an ocular coil filled with ketorolac loaded PMMA microspheres. Nine different ocular coils were created, ranging in wire diameter and coiled outer diameter. Based on its microsphere holding capacity and flexibility, one type of ocular coil was selected and used for further experiments. No escape of microspheres was observed after bending the ocular coil at curvature which reflect the in vivo situation in human upon positioning in the lower conjunctival sac. Shape behavior and tissue contact were investigated by computed tomography imaging after inserting the ocular coil in the lower conjunctival fornix of a human cadaver. Thanks to its high flexibility, the ocular coil bends along the circumference of the eye. Because of its location deep in the fornix, it appears unlikely that in vivo, the ocular coil will interfere with eye movements. In vitro drug release experiments demonstrate the potential of the ocular coil as sustained drug delivery device for the eye. We developed PMMA microspheres with a 26.5 ± 0.3 wt% ketorolac encapsulation efficiency. After 28 days, 69.9% ± 5.6% of the loaded ketorolac was released from the ocular coil when tested in an in vitro lacrimal system. In the first three days high released dose (48.7% ± 5.4%) was observed, followed by a more gradually release of ketorolac. Hence, the ocular coil seems a promising carrier for ophthalmic drugs delivery in the early postoperative time period.

Intercostal nerve block of the anterior cutaneous branches and the sensibility of the female breast.

INTRODUCTION: Better sensation in the reconstructed breast improves the quality of life. Sensory nerve coaptation is a valuable addition to autologous breast reconstruction. There are few publications concerning the sensory nerves of the breast and the nipple-areola complex and reports are contradictory, so it is unknown which nerve is best suited as a recipient for coaptation. The current study serves as a proof of concept. MATERIALS AND METHODS: The areas innervated by the anterior cutaneous branches (ACBs) of the intercostal nerves (ICNs) were studied on two separate occasions in two healthy women. First, the ACBs of ICNs 2-5 were individually blocked using ultrasound. Next, the ACBs of all levels were blocked simultaneously. Sensation was measured using Semmes-Weinstein monofilaments. The numbed areas corresponding to the ICNs were drawn in a raster of 2 × 2 cm. RESULTS: The largest area was supplied by the ACB of the 4th ICN, located in the upper (UIQ) and the lower (LIQ) inner quadrants of the breast. The 2nd-largest area was supplied by the ACB of the 3rd ICN. Blockage of ACBs 2-5 affected sensation in the nipple and the areola. CONCLUSIONS: Blockage of all levels 2-5 partially affected sensation in the nipple-areola complex, suggesting innervation by a nerve plexus consisting of both ACBs and lateral cutaneous branches (LCBs). ACB4 supplied the largest area of the breast in the UIQ and LIQ and could be best suited for sensory nerve coaptation to optimize sensation in the autologously reconstructed breast.

Sensory Recovery of the Breast following Innervated and Noninnervated DIEP Flap Breast Reconstruction.

BACKGROUND: The sensory recovery of the breast remains an undervalued aspect of autologous breast reconstruction. The aim of this study was to evaluate the effect of nerve coaptation on the sensory recovery of the breast following DIEP flap breast reconstruction and to assess the associations of length of follow-up and timing of the reconstruction. METHODS: A prospective comparative study was conducted of all patients who underwent either innervated or noninnervated DIEP flap breast reconstruction and returned for follow-up between September of 2015 and July of 2017. Nerve coaptation was performed to the anterior cutaneous branch of the third intercostal nerve. Semmes-Weinstein monofilaments were used for sensory testing of the native skin and flap skin. RESULTS: A total of 48 innervated DIEP flaps in 36 patients and 61 noninnervated DIEP flaps in 45 patients were tested at different follow-up time points. Nerve coaptation was significantly associated with lower monofilament values in all areas of the reconstructed breast (adjusted difference, -1.2; p < 0.001), which indicated that sensory recovery of the breast was significantly better in innervated compared with noninnervated DIEP flaps. For every month of follow-up, the mean monofilament value decreased by 0.083 in innervated flaps (p < 0.001) and 0.012 in noninnervated flaps (p < 0.001). Nerve coaptation significantly improved sensation in both immediate and delayed reconstructions. CONCLUSIONS: This study demonstrated that nerve coaptation in DIEP flap breast reconstruction is associated with a significantly better sensory recovery in all areas of the reconstructed breast compared with noninnervated flaps. The length of follow-up was significantly associated with the sensory recovery.

Optical signature of nerve tissue-Exploratory ex vivo study comparing optical, histological, and molecular characteristics of different adipose and nerve tissues.

BACKGROUND: During several anesthesiological procedures, needles are inserted through the skin of a patient to target nerves. In most cases, the needle traverses several tissues-skin, subcutaneous adipose tissue, muscles, nerves, and blood vessels-to reach the target nerve. A clear identification of the target nerve can improve the success of the nerve block and reduce the rate of complications. This may be accomplished with diffuse reflectance spectroscopy (DRS) which can provide a quantitative measure of the tissue composition. The goal of the current study was to further explore the morphological, biological, chemical, and optical characteristics of the tissues encountered during needle insertion to improve future DRS classification algorithms. METHODS: To compare characteristics of nerve tissue (sciatic nerve) and adipose tissues, the following techniques were used: histology, DRS, absorption spectrophotometry, high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, and solution 2D 13 C-1 H heteronuclear single-quantum coherence spectroscopy. Tissues from five human freshly frozen cadavers were examined. RESULTS: Histology clearly highlights a higher density of cellular nuclei, collagen, and cytoplasm in fascicular nerve tissue (IFAS). IFAS showed lower absorption of light around 1200 nm and 1750 nm, higher absorption around 1500 nm and 2000 nm, and a shift in the peak observed around 1000 nm. DRS measurements showed a higher water percentage and collagen concentration in IFAS and a lower fat percentage compared to all other tissues. The scattering parameter (b) was highest in IFAS. The HR-MAS NMR data showed three extra chemical peak shifts in IFAS tissue. CONCLUSION: Collagen, water, and cellular nuclei concentration are clearly different between nerve fascicular tissue and other adipose tissue and explain some of the differences observed in the optical absorption, DRS, and HR-NMR spectra of these tissues. Some differences observed between fascicular nerve tissue and adipose tissues cannot yet be explained but may be helpful in improving the discriminatory capabilities of DRS in anesthesiology procedures. Lasers Surg. Med. 50:948-960, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

The Lateral Thigh Perforator Flap for Autologous Breast Reconstruction: A Prospective Analysis of 138 Flaps.

BACKGROUND: The septocutaneous tensor fasciae latae or lateral thigh perforator flap was previously introduced by the authors' group as an alternative flap for autologous breast reconstruction when the abdomen is not suitable as a donor site. The authors analyzed their experience with the lateral thigh perforator flap and present the surgical refinements that were introduced. METHODS: A prospective study was conducted of all lateral thigh perforator flap breast reconstructions performed since September of 2012. Patient demographics, operative details, complications, and flap reexplorations were recorded. Preoperative imaging with magnetic resonance angiography was performed in all patients. Surgical refinements introduced during this study included limitation of the flap width and the use of quilting sutures at the donor site. RESULTS: A total of 138 lateral thigh perforator flap breast reconstructions were performed in 86 consecutive patients. Median operative times were 277 minutes (range, 196 to 561 minutes) for unilateral procedures and 451 minutes (range, 335 to 710 minutes) for bilateral. Median flap weight was 348 g (range, 175 to 814 g). Two total flap losses (1.4 percent) were recorded, and 11 flaps (8.0 percent) required reexploration, which resulted in viable flaps. The incidence of donor-site complications was reduced significantly after the surgical refinements were introduced. Wound problems decreased from 40.0 percent to 6.3 percent, seroma decreased from 25.0 percent to 9.5 percent, and infection decreased from 27.5 percent to 9.5 percent. CONCLUSIONS: The lateral thigh perforator flap is an excellent option for autologous breast reconstruction, with minimal recipient-site complications. The surgical refinements resulted in a significant reduction of donor-site complications. Therefore, the lateral thigh perforator flap is currently the authors' second choice after the deep inferior epigastric artery perforator flap. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Comparing the sensation of common donor site regions for autologous breast reconstruction to that of a healthy breast.

INTRODUCTION: Autologous breast reconstruction has become the standard care for breast cancer patients. Although excellent cosmetic results can be achieved, most reconstructed breasts fail to regain normal sensation. Nerve coaptation of the flap has been suggested to improve sensation; the effect of the donor flap native sensory threshold on the degree of sensory restoration is yet to be determined. The aim of this study is to evaluate the differences in sensation between various potential donor site regions in comparison to the sensation of the healthy breast. PATIENTS AND METHODS: A cross-sectional study in healthy women was performed in the Maastricht University Medical Centre. Monofilaments were used to measure sensation in the breast and at different flap donor sites: deep inferior epigastric perforator (DIEP), lateral thigh perforator (LTP), profunda artery perforator (PAP), superior gluteal artery perforator (SGAP) and transverse musculocutaneous gracilis (TMG) flaps. The Wilcoxon signed rank test was used to analyse statistical significance in sensation. RESULTS: Fifty women with a mean age of 49 ± 2.72 years and mean BMI of 26.14 ± 0.89 kg/m2 were included in the study. The median monofilament value of the normal breasts was 2.97(2.56-3.55). The median monofilament value of each donor site and p value when compared to the healthy breast were as follows: DIEP flap, 2.62 (2.36-3.22) p < 0.01; LTP flap, 3.61 (2.83-4.08) p <0.01; PAP flap, 3.09 (2.67-3.5) p = 0.97; SGAP flap, 3.22 (2.64-3.87) p = 0.01; and TMG flap, 3.03 (2.6-3.47) p = 0.69. CONCLUSIONS: There is a significant difference in sensation between the various donor site regions for breast reconstruction and the healthy breast. This may be taken into consideration for donor site selection.

Boundaries of the thoracic paravertebral space: potential risks and benefits of the thoracic paravertebral block from an anatomical perspective.

PURPOSE: Thoracic paravertebral block (TPVB) may be an alternative to thoracic epidural analgesia. A detailed knowledge of the anatomy of the TPV-space (TPVS), content and adnexa is essential in understanding the clinical consequences of TPVB. The exploration of the posterior TPVS accessibility in this study allows (1) determination of the anatomical boundaries, content and adnexa, (2) description of an ultrasound-guided spread of low and high viscous liquid. METHODS: In two formalin-fixed specimens, stratification of the several layers and the 3D-architecture of the TPVS were dissected, observed and photographed. In a third unembalmed specimen, ultrasound-guided posterolateral injections at several levels of the TPVS were performed with different fluids. RESULTS: TPVS communicated with all surrounding spaces including the segmental dorsal intercostal compartments (SDICs) and the prevertebral space. TPVS transitions to the SDICs were wide, whereas the SDICs showed narrowed transitions to the lateral intercostal spaces at the costal angle. Internal subdivision of the TPVS in a subendothoracic and an extra-pleural compartment by the endothoracic fascia was not observed. Caudally injected fluids spread posteriorly to the costodiaphragmatic recess, showing segmental intercostal and slight prevertebral spread. CONCLUSIONS: Our detailed anatomical study shows that TPVS is a potential space continuous with the SDICs. The separation of the TPVS in a subendothoracic and an extra-pleural compartment by the endothoracic fascia was not observed. Based on the ultrasound-guided liquid spread we conclude that the use of a more lateral approach might increase the probability of intravascular puncture or catheter position.

Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

BACKGROUND: Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. METHODS: Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. RESULTS: No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. CONCLUSIONS: We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

Development and assessment of a digital X-ray software tool to determine vertebral rotation in adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: The amount of vertebral rotation in the axial plane is of key importance in the prognosis and treatment of adolescent idiopathic scoliosis (AIS). Current methods to determine vertebral rotation are either designed for use in analogue plain radiographs and not useful in digital images, or lack measurement precision and are therefore less suitable for the follow-up of rotation in AIS patients. PURPOSE: This study aimed to develop a digital X-ray software tool with high measurement precision to determine vertebral rotation in AIS, and to assess its (concurrent) validity and reliability. STUDY DESIGN/SETTING: In this study a combination of basic science and reliability methodology applied in both laboratory and clinical settings was used. METHODS: Software was developed using the algorithm of the Perdriolle torsion meter for analogue AP plain radiographs of the spine. Software was then assessed for (1) concurrent validity and (2) intra- and interobserver reliability. Plain radiographs of both human cadaver vertebrae and outpatient AIS patients were used. Concurrent validity was measured by two independent observers, both experienced in the assessment of plain radiographs. Reliability-measurements were performed by three independent spine surgeons. RESULTS: Pearson correlation of the software compared with the analogue Perdriolle torsion meter for mid-thoracic vertebrae was 0.98, for low-thoracic vertebrae 0.97 and for lumbar vertebrae 0.97. Measurement exactness of the software was within 5° in 62% of cases and within 10° in 97% of cases. Intraclass correlation coefficient (ICC) for inter-observer reliability was 0.92 (0.91-0.95), ICC for intra-observer reliability was 0.96 (0.94-0.97). CONCLUSIONS: We developed a digital X-ray software tool to determine vertebral rotation in AIS with a substantial concurrent validity and reliability, which may be useful for the follow-up of vertebral rotation in AIS patients.

A Modified Posterolateral Approach for Radiofrequency Denervation of the Medial Branch of the Cervical Segmental Nerve in Cervical Facet Joint Pain Based on Anatomical Considerations.

The cervical facet joints, also called the zygapophyseal joints, are a potential source of neck pain (cervical facet joint pain). The cervical facet joints are innervated by the cervical medial branches (CMBs) of the cervical segmental nerves. Cervical facet joint pain has been shown to respond to multisegmental radiofrequency denervation of the cervical medial branches. This procedure is performed under fluoroscopic guidance. Currently, three approaches are described and used. Those three techniques of radiofrequency treatment of the CMBs, classified on the base of the needle trajectory toward the anatomical planes, are as follows: the posterolateral technique, the posterior technique, and the lateral technique. We describe the three techniques with their advantages and disadvantages. Anatomical studies providing a topographic anatomy of the course of the CMBs are reviewed. We developed a novel approach based on the observed strengths and weaknesses of the three currently used approaches and based on recent anatomical findings. With this fluoroscopic-guided approach, there is always bone (the facet column) in front of the needle, which makes it safer, and the insertion point is easier to determine without the risk of positioning the radiofrequency needle too dorsally.

UHMWPE Sublaminar Wires in Posterior Spinal Instrumentation: Stability and Biocompatibility Assessment in an Ovine Pilot Study.

STUDY DESIGN: An animal study. OBJECTIVE: To explore ultra-high molecular weight polyethylene (UHMWPE) sublaminar wires in spinal surgery and to assess stability and biocompatibility of the UHMWPE instrumentation in an ovine model. SUMMARY OF BACKGROUND DATA: Sublaminar wiring is a well-established technique in segmental scoliosis surgery. However, during introduction and/or removal of the metal sublaminar wires, neurological problems can occur. Abrasion after cutting metal wires for removal can lead to damage to the dural sac. Sublaminar wires have to withhold large forces and breakage of the wires can occur. Different types of sublaminar wires have been developed to address these problems. UHMWPE sublaminar wires can potentially substitute currently used metal sublaminar metal wires. In vivo testing and biocompatibility analysis of UHMWPE wires are recommended before clinical use in spinal surgery. MATERIALS AND METHODS: In 6 immature sheep, pedicle screws were instrumented at lumbar level L4 and attached with titanium rods to 4 thoracolumbar vertebrae using 3- and 5-mm-wide UHMWPE sublaminar wiring constructions in 5 animals. Titanium sublaminar wires were applied in 1 animal to function as a control subject. After a follow-up period of 16 weeks, the animals were sacrificed and the spines were isolated. Radiographs and computed tomography (CT) scans were made to assess stability of the instrumentation. The vertebrae were dissected for macroscopic and histologic evaluation. RESULTS: None of the wires had loosened and the instrumentation remained stable. CT scans and radiographs showed no signs of failure of the instrumentation and no neurological complications occurred. Although several bony bridges were seen on CT, growth was observed at the operated levels. Biocompatibility was assessed by macroscopical and histologic analysis, showing no signs of dural or epidural inflammation. CONCLUSIONS: This pilot animal study shows that UHMWPE sublaminar wiring is a safe technique. The UHMWPE wires are biocompatible and provide sufficient stability in spinal instrumentation. Heterotopic ossification because of periost reactions in the ovine spine led to some restrictions in this study.

The Role of Spectral Tissue Sensing During Lumbar Transforaminal Epidural Injection.

Spectral tissue sensing (STS) exploits the scattering and absorption of light by tissue. The main objective of the present study was to determine whether STS can discriminate between correct and incorrect placement of the needle tip during lumbar transforaminal epidural injection. This was a single-blind prospective observational study in 30 patients with lumbar radicular pain scheduled for lumbar transforaminal epidural injection. Spectral tissue sensing data from the needle tip were acquired along the needle trajectory at 4 predefined measurement points and compared with ultrasound, fluoroscopy, and digital subtraction angiography images. Spectral tissue sensing data contained the full spectra. The lipid and hemoglobin content at the different measurement points was also calculated, and partial least-squares discriminant analysis was used to estimate the sensitivity and specificity of STS. Spectral tissue sensing identified correct needle placement with a sensitivity of 57% and a specificity of 82%, and intraforaminal versus extraforaminal locations were identified with a sensitivity of 80% and a specificity of 71%.