Does prophylactic decompression of distal nerves following nerve repair improve functional recovery? A systematic review.

BACKGROUND: Peripheral nerve injuries are burdensome on healthcare systems, individuals and society as a whole. The current standard of treatment for neurotmesis is primary neurorrhaphy or nerve grafting. However, several patients do not recover their full function. There has been a suggestion that primary distal neurolysis at common entrapment sites maximises surgical outcomes; however, no guidelines exist on this practice. This scoping review aims to ascertain the existing evidence on prophylactic distal decompression of peripheral nerves following repair. METHODS: A literature search was performed using Ovid Medline, PubMed, Embase and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews for studies published in the past 50 years. Studies were screened using a selection criteria and study quality was assessed using standardised tools. Furthermore, thematic content analysis was performed. RESULTS: Six studies were eligible for inclusion after screening; all studies were retrospective and at most level 3 evidence. No studies were designed specifically to assess the efficacy of distal neurolysis following proximal repair, thus no comparative data with control cohorts are available. All studies that recommended distal decompression of proximally repaired nerves based their conclusions on cases observed by the authors in practice or from theories on nerve regeneration. CONCLUSIONS: This systematic review suggests that the evidence on the role of immediate distal neurolysis in primary neurorrhaphy is inadequate. Recommendations are limited by the lack of large-scale and generalisable data. Further research is needed with definitive objective outcomes and patient-related outcome measures.

T2-weighted MRI defines critical compression in the distal carpal tunnel that is relieved after decompressive surgery.

INTRODUCTION: Despite carpal tunnel syndrome (CTS) being the most common entrapment neuropathy, its pathophysiology remains debated. Sub-synovial connective tissues (SSCT) within the carpal tunnel are thought to play a role but are poorly characterised. MRI analysis offers potentially novel insights into SSCT characteristics. METHODS: A pilot study of T2-weighted MRI was performed in healthy controls (n = 7), and in CTS patients (n = 16) pre- and 6 months post-surgical decompression. Image analysis was performed to quantify SSCT cross-sectional area, SSCT signal intensity ratio, and wrist index (depth/width) at distal, middle, and proximal wrist landmarks. RESULTS: Median SSCT signal intensity was lower in the distal carpal tunnel of CTS patients pre-operatively (0.96) compared to controls (1.13; P = 0.008) and normalised post-operatively (1.13, P = 0.001). Median wrist index was also lower in CTS patients pre-operatively (0.60) than in controls (0.67, P = 0.022), and again normalised post-operatively (0.74, P = 0.001). This was attributed to changes in carpal depth in the anteroposterior axis with decompression surgery. CONCLUSION: This pilot study successfully demonstrated MRI assessment of SSCT in patients with CTS. The decreased SSCT signal intensities suggest predominant changes at the distal tunnel, potentially indicating reduced SSCT perfusion pre-surgery which normalised post-surgery. Our preliminary findings merit further investigation in a larger cohort.

Replication of epidemiological associations of carpal tunnel syndrome in a UK population-based cohort of over 400,000 people.

INTRODUCTION: Several phenotypic factors are associated in the literature with an increased risk of carpal tunnel syndrome (CTS). Along with female sex and older age, certain systemic diseases show an association with CTS, with varying degrees of evidence. METHODS: This study was performed using the UK Biobank resource - a cohort study of over 500,000 participants who have allowed linkage of phenotypic data with their medical records. We calculated the prevalence of CTS and a sex-specific prevalence ratio and compared the body mass index (BMI) between cases and controls. We performed a series of nested case-control studies to compute odds ratios for the association between CTS and three systemic diseases. RESULTS: There were 12,312 CTS cases within the curated UK Biobank dataset of 401,656 (3.1% prevalence), and the female:male ratio was 1.95:1. CTS cases had, on average, a BMI > 2.0 kg/m2 greater than controls. Odds ratios for the association with CTS for three systemic diseases were 2.31 (95% CI 2.17-2.46) for diabetes, 2.70 (95% CI 2.44-2.99) for rheumatoid arthritis, and 1.47 (95% CI 1.38-1.57) for hypothyroidism. Adjusted for BMI, these odds ratios fell to 1.75 (95% CI 1.65-1.86), 2.43 (95% CI 2.20-2.69), and 1.35 (95% CI 1.26-1.43), respectively. DISCUSSION: We harnessed the size and power of UK Biobank to provide robust replication of evidence for the associations between CTS and female sex, raised BMI, and three systemic diseases, which are only mediated in part by raised BMI.

Necrotising fasciitis of the thigh secondary to colonic perforation: the femoral canal as a route for infective spread.

A 57 year-old man with a history of corticosteroid use presented with abdominal pain and diarrhoea. He was initially treated for presumed Clostridium difficile colitis, but later developed a left inguinal mass with spreading erythema. A CT scan showed gas within the retroperitoneal tissues, with surgical emphysema of the left groin. Necrotising fasciitis was diagnosed, and the patient underwent extensive debridement of the left thigh and inguinal region. The femoral vein was covered in infected fascia in the femoral canal, and a laparotomy revealed a posterior perforation of the sigmoid colon. Necrotising fasciitis of the thigh is a rare complication of colonic perforation. Our case highlights the femoral canal as a potential channel for the spread of intra-abdominal infection into the thigh.

Hyperplasia of the parotid gland U.N.S. A stress phenomenon?

The secretory function of the parotid glands, as represented by the salivary secretion rate, has been examined in 10 patients with parotid hyperplasia U.N.S. Different levels of gustatory stimulation were used. The secretion rate was reduced in 8 out of 10 of the patients at a moderately high level of stimulation but normal at submaximum levels in all the 10 patients. The results suggest that the cause of the parotid hyperplasia may be an elevated sympathetic influence, possibly due to stress.