Analysis of Mechanoreceptors and Free Nerve Endings of the Transverse Carpal Ligament.

Background: The treatment of carpal tunnel syndrome (CTS) by sectioning the transverse carpal ligament (TCL) is not exempt from complications. Some nerve branches may be damaged by the incision. The aim of this study is to identify and map the TCL nerve endings, serving as a guide for sectioning this structure in a zone with less nerve ending density. Methods: Ten TCLs were obtained from fresh frozen cadavers. The TCLs were measured, divided into 3 equal bands (radial, central, and ulnar), and submitted to cryostat sectioning. The sections were subjected to immunofluorescence with the protein gene product (PGP) 9.5 and confocal microscopy analysis. Results: All the specimens contained type I and type IV mechanoreceptors. Neural elements occupied 0.695 ± 0.056% of the ligament area. The density of the neural elements was greater in the radial, followed by the ulnar and central bands, with 0.730 ± 0.083%, 0.686 ± 0.009%, and 0.669 ± 0.031%, respectively. Conclusion: The present findings suggest that the region with the least potential for neural element injury during TCL release is the central third near the transition with the ulnar third. When performed distally to proximally with a slight inclination from the radial to the ulnar, this release compromises the lowest nerve element density. Topographically, the proximal limit of the release is the distal wrist crease, while the distal limit is the intersection of Kaplan cardinal line and the axis of the third webspace.

Surgical outcome following rotator cuff tear repair in a low-income population. Impact of obesity and smoking.

BACKGROUND: Comorbidities and socioeconomic issues impact outcome of rotator cuff tear (RCT) repair. There are no data on RCT repair outcome from developing regions. We determined the impact of obesity and smoking following RCT repair in a low-income population. METHODS: This is a retrospective case series. Forty-seven shoulders of 42 patients subjected to open or arthroscopic repair of a RCT with a minimum of 2 years follow-up were cross-sectionally evaluated. Patients were seen in the Orthopaedic Service of the Hospital Geral de Fortaleza-CE, Brazil between March and September 2018. RCT were classified as partial or full-thickness lesions. Fatty infiltration (Goutallier) and tendon retraction (Patte) were recorded as well as obesity (BMI > 30), literacy [>/≤ 8 school years (SY)] and smoking status 6 months prior to surgery (present/absent). Outcomes included pain (visual analogue scale; VAS, 0-10 cm), range of motion [active forward flexion and external rotation (ER)], UCLA and ASES scoring. RESULTS: Patients were 59.9 ± 7.4 years-old, 35(74.4%) female with 19 (17.1-30.2 IQR) median of months from diagnosis to surgery and 25 median months of follow-up (26.9-34.0 IQR); over 90% declared < 900.00 US$ monthly family income and two-thirds had ≤8 SY. Forty patients (85.1%) had full-thickness tears, 7 (14.9%) had Goutallier ≥3 and over 80% had < Patte III stage. Outcomes were similar regardless of fatty infiltration or tendon retraction staging. There were 17 (36.1%) smokers and 13 (27.6%) obese patients. Outcome was similar when comparing obese vs non-obese patients. Smokers had more pain (P = 0.043) and less ER (P = 0.029) with a trend towards worse UCLA and ASES scores as compared to non-smokers though differences did not achieve minimal clinically important difference (MCID) proposed for surgical RCT treatment. After adjusting for obesity, VAS and ER values in smokers were no longer significant (P = 0.2474 and 0.4872, respectively). CONCLUSIONS: Our data document outcomes following RCT repair in a low-income population. Smoking status but not obesity impacted RCT repair outcome though not reaching MCID for surgical treatment.

The characteristics of the mechanoreceptors of the hip with arthrosis.

Mechanoreceptors have been extensively studied in different joints and distinct signals that convey proprioceptive information to the cortex. Several clinical reports have established a link between the number of mechanoreceptors and a deficient proprioceptive system; however, little or no literature suggest concentration of mechanoreceptors might be affected by hip arthrosis. The purpose of this study is first to determine the existence of mechanoreceptors and free nerve endings in the hip joint and to distinguish between their conditions: those with arthrosis and without arthrosis. Samples of 45 male hips were analyzed: 30 taken from patients with arthrosis that were submitted to total arthroplasty and 15 taken from male cadavers without arthrosis. The patients' ages ranged from 38 to75 years (average 56.5) and the cadavers' ages ranged from 21 to 50 years (average 35.5). The capsule, labrum, and femoral head ligament tissues were obtained during the arthroplasty procedure from 30 patients with arthrosis and from 15 male cadavers. The tissue was cut into fragments of around 3 mm. Each fragment was then immediately stained with gold chloride 1% solution and divided into sections of 6 µm thickness. The Mann-Whitney test was used for two groups and the ANOVA, Friedman and Kruskal-Wallis tests for more than two groups. Results show the mechanoreceptors (Pacini, Ruffini and Golgi corpuscles) and free nerve endings are present in the capsule, femoral head ligament, and labrum of the hip joint. When all the densities of the nerve endings were examined with regard to those with arthrosis and those without arthrosis, the mechanoreceptors of cadavers without arthrosis were found to be more pronounced and an increase in free nerve endings could be observed (p = 0.0082). Further studies, especially electrophysiological studies, need to be carried out to clarify the functions of the mechanoreceptors in the joints.

Effect of imiquimod on partial-thickness burns.

BACKGROUND: Burns can result in substantial morbidity through fibroblast proliferation and contracture. Imiquimod (IMQ), an immune response modifier and upregulator of endogenous cytokine expression, has been shown to suppress fibroblast proliferation. It is widely used in the treatment of viral, neoplastic and non-neoplastic skin conditions and has recently been tested in the reduction of hypertrophic scarring and keloids. To our knowledge, no other study has so far evaluated the effect of IMQ on cutaneous burns. METHODS: Partial-thickness burns were produced on the dorsum of 32 Wistar rats. Right-sided wounds received saline and left-sided wounds received 5% IMQ cream three times/week following injury. Photographs taken on post-burn days (PBD) 4, 7, 14 and 21 were evaluated for wound appearance using a clinical assessment scale and a visual analog scale. Scars were measured by digital planimetry. Samples stained with hematoxylin-eosin were submitted to conventional histological analysis. Samples stained with Sirius Red were analyzed under polarized light for collagen morphometry. RESULTS: Visual scores were higher in the saline group on PBD 21 (p<0.05). Wound edge migration rates were lower (p<0.05) and conventional histology showed accentuated inflammation and delayed reepithelialization in the IMQ group. Type-I and type-III collagen deposition increased in the saline group and decreased in the IMQ group. Conversely, the proportion between type-I and type-III collagen differed significantly between treatments on PBD 4 and 21 (p<0.05 in both cases). CONCLUSIONS: Short-term topical imiquimod treatment of partial-thickness burns in rats did not improve clinical appearance and scarring but rather decreased fibrosis. Significant differences in collagen deposition were observed between the treatments.