To Improve Your Surgical Drilling Skills, Make Use of Your Index Fingers

BACKGROUND: Surgery has greatly benefited from various technologic advancements over the past decades. Surgery remains, however, mostly manual labor performed by well-trained surgeons. Little research has focused on improving osseous drilling techniques. The objective of this study was to compare the accuracy and precision of different orthopaedic drilling techniques involving the use of both index fingers. QUESTIONS/PURPOSES: (1) Does the shooting grip technique and aiming at the contralateral index finger improve accuracy and precision in drilling? (2) Is the effect of drilling technique on accuracy and precision affected by the experience level of the performer? METHODS: This study included 36 participants from two Dutch training hospitals who were subdivided into three groups (N = 12 per group) based on their surgical experience (that is, no experience, residents, and surgeons). The participants had no further experience with drilling outside the hospital nor were there other potential confounding variables that could influence the test outcomes. Participants were instructed to drill toward a target exit point on a synthetic bone model. There were four conditions: (1) clenched grip without aiming; (2) shooting grip without aiming; (3) clenched grip with aiming at the contralateral index finger; and (4) shooting grip aiming at the contralateral index finger. Participants were only used to a clenched grip without aiming in clinical practice. Each participant had to drill five times per technique per test, and the test was repeated after 4 weeks. Accuracy was defined as the systematic error of all measurements and was calculated as the mean of the five distances between the five exit points and the target exit point, whereas precision was defined as the random error of all measurements and calculated as the SD of those five distances. Accuracy and precision were analyzed using mixed-design analyses of variance. RESULTS: Accuracy was highest when using a clenched grip with aiming at the index finger (mean 4.0 mm, SD 1.1) compared with a clenched grip without aiming (mean 5.0 mm, SD 1.2, p = 0.004) and a shooting grip without aiming (mean 4.9 mm, SD 1.4, p = 0.015). The shooting grip with aiming at the index finger (mean 4.1 mm, SD 1.2) was also more accurate than a clenched grip without aiming (p = 0.006) and a shooting grip without aiming (p = 0.014). Shooting grip with aiming at the opposite index finger (median 2.0 mm, interquartile range [IQR] 1.2) showed the best precision and outperformed a clenched grip without aiming (median 2.9 mm, IQR 1.1, p = 0.016), but was not different than the shooting grip without aiming (median 2.2 mm, IQR 1.4) or the clenched grip with aiming (median 2.4 mm, IQR 1.3). The accuracy of surgeons (mean 4.1 mm, SD 1.1) was higher than the inexperienced group (mean 5.0 mm, SD 1.1, p = 0.012). The same applied for precision (median 2.2 mm, IQR 1.0 versus median 2.8 mm, IQR 1.4, p = 0.008). CONCLUSIONS: A shooting grip combined with aiming toward the index finger of the opposite hand had better accuracy and precision compared with a clenched grip alone. Based on this study, experience does matter, because the orthopaedic surgeons outperformed the less experienced participants. Based on our study, we advise surgeons to aim at the index finger of the opposite hand when possible and to align the ipsilateral index finger to the drill bit. LEVEL OF EVIDENCE: Level II, therapeutic study

Early changes in the extracellular matrix of the degenerating intervertebral disc, assessed by Fourier transform infrared imaging.

Mechanical overloading induces a degenerative cell response in the intervertebral disc. However, early changes in the extracellular matrix (ECM) are challenging to assess with conventional techniques. Fourier Transform Infrared (FTIR) imaging allows visualization and quantification of the ECM. We aim to identify markers for disc degeneration and apply these to investigate early degenerative changes due to overloading and katabolic cell activity. Three experiments were conducted; Exp 1.: In vivo, lumbar spines of seven goats were operated: one disc was injected with chondroitinase ABC (mild degeneration) and compared to the adjacent disc (control) after 24 weeks. Exp 2a: Ex vivo, caprine discs received physiological loading (n=10) or overloading (n=10) in a bioreactor. Exp 2b: Cell activity was diminished prior to testing by freeze-thaw cycles, 18 discs were then tested as in Exp 2a. In all experiments, FTIR images (spectral region: 1000-1300 cm ) of mid-sagittal slices were analyzed using multivariate curve resolution. In vivo, FTIR was more sensitive than biochemical and histological analysis in identifying reduced proteoglycan content (p=0.046) and increased collagen content in degenerated discs (p<0.01). Notably, FTIR analysis additionally showed disorganization of the ECM, indicated by increased collagen entropy (p=0.011). Ex vivo, the proteoglycan/collagen ratio decreased due to overloading (p=0.047) and collagen entropy increased (p=0.047). Cell activity affected collagen content only (p=0.044). FTIR imaging allows a more detailed investigation of early disc degeneration than traditional measures. Changes due to mild overloading could be assessed and quantified. Matrix remodeling is the first detectable step towards intervertebral disc degeneration. [Abstract copyright: Copyright © 2018. Published by Elsevier Ltd.

Prognostic factors in the progression of intervertebral disc degeneration:Which patient should be targeted with regenerative therapies?

Objective: Possible regenerative treatments for lumbar intervertebral disc degeneration (DD) are rapidly emerging. There is consensus that the patient that would benefit most has early-stage DD, with a predicted deterioration in the near future. To identify this patient, the aim of this study was to identify prognostic factors for progression of DD. Study design: Systematic review. Methods: A systematic search was performed on studies evaluating one or more prognostic factor(s) in the progression of DD. The criteria for inclusion were (a) patients diagnosed with DD on MRI, (b) progression of DD at follow-up, and (c) reporting of one or more prognostic factor(s) in progression of DD. Two authors independently assessed the methodological quality of the included studies. Due to heterogeneity in DD determinants and outcomes, only a best-evidence synthesis could be conducted. Results: The search generated 3165 references, of which 16 studies met our inclusion criteria, involving 2.423 patients. Within these, a total of 23 clinical and environmental and 12 imaging factors were identified. There was strong evidence that disc herniation at baseline is associated with progression of DD at follow-up. There is limited evidence that IL6 rs1800795 genotype G/C male was associated with no progression of DD. Some clinical or environmental factors such as BMI, occupation and smoking were not associated with progression. Conclusions: Disc herniation is strongly associated with the progression of DD. Surprisingly, there was strong evidence that smoking, occupation, and several other factors were not associated with the progression of DD. Only one genetic variant may have a protective effect on progression, otherwise there was conflicting or only limited evidence for most prognostic factors. Future research into these prognostic factors with conflicting and limited evidence is not only needed to determine which patients should be targeted by regenerative therapies, but will also contribute to spinal phenotyping

Osteoarthritis and intervertebral disc degeneration:Quite different, quite similar

Intervertebral disc degeneration describes the vicious cycle of the deterioration of intervertebral discs and can eventually result in degenerative disc disease (DDD), which is accompanied by low-back pain, the musculoskeletal disorder with the largest socioeconomic impact world-wide. In more severe stages, intervertebral disc degeneration is accompanied by loss of joint space, subchondral sclerosis, and osteophytes, similar to osteoarthritis (OA) in the articular joint. Inspired by this resemblance, we investigated the analogy between human intervertebral discs and articular joints. Although embryonic origin and anatomy suggest substantial differences between the two types of joint, some features of cell physiology and extracellular matrix in the nucleus pulposus and articular cartilage share numerous parallels. Moreover, there are great similarities in the response to mechanical loading and the matrix-degrading factors involved in the cascade of degeneration in both tissues. This suggests that the local environment of the cell is more important to its behavior than embryonic origin. Nevertheless, OA is widely regarded as a true disease, while intervertebral disc degeneration is often regarded as a radiological finding and DDD is undervalued as a cause of chronic low-back pain by clinicians, patients and society. Emphasizing the similarities rather than the differences between the two diseases may create more awareness in the clinic, improve diagnostics in DDD, and provide cross-fertilization of clinicians and scientists involved in both intervertebral disc degeneration and OA