An Evidence-Based Approach to the Differentiation of Compressive Neuropathy from Polysensory Neuropathy in the Upper Extremity

Controllable forces for reproducible chronic constriction injury mimicking compressive neuropathy in rat sciatic nerve

BACKGROUND

Compressive neuropathy is a recurring and challenging disease for patients, regardless of medical or surgical treatment. Neuropathological severity is associated with the force of mechanical compression. Available animal models do not address mechanical issues with reproducible outcomes. We used a chronic constriction injury model to analyze tension-controlled compressive neuropathy and achieve reproducible functional outcomes.

NEW METHOD

We refined a modified animal model for chronic constriction nerve injury under controllable compressive tensile strength to target the unilateral sciatic nerve of adult rats. Sensory outcomes were evaluated using the Von Frey test. Muscle atrophy and nerve degeneration were analyzed, including markers of neural degeneration, neuroinflammation, and neuropathic pain in the affected nerve.

RESULTS

The compressive force significantly affected the neuropathological severity of sensory dysfunction and muscle atrophy. Greater mechanical forces (i.e., tight-knot) contributed to muscle atrophy and hypoesthesia. Low forces (i.e., loose-knot) induced mechanical allodynia with better residual muscle weight. Well-controlled loose knotting can avoid myelin degradation while lessening neuroinflammation and macrophage infiltration. Neuropathic pain was enhanced with increased nociceptive pain markers expression within the affected nerve. Comparison with Existing Method(s): Our chronic constriction injury model, unlike previous models, controls the ligation forces applied for different levels of injury.

CONCLUSION

The functional influences of different compressive forces recapitulate the diverse clinical symptoms involved in clinical compressive neuropathy. This controllable and reproducible model of compressive neuropathy revealed the underlying molecular mechanisms of neural degeneration and inflammation. It will lead to the future development of translational therapeutics for neuropathic pain and nerve regeneration.

Comparison of Wrist Arthroscopy, Small Incision Surgery, and Conventional Surgery for the Treatment of Carpal Tunnel Syndrome: A Retrospective Study at a Single Center

Background

This study aimed to compare the efficacy and safety of wrist arthroscopy, small incision surgery, and conventional open carpal tunnel release surgery for the treatment of carpal tunnel syndrome.

Material/Methods

Patients with carpal tunnel syndrome (n=111) were treated with wrist arthroscopy (n=33), small incision surgery (n=40), and conventional open carpal tunnel release surgery (n=38). Incision length, duration of surgery, degree of intraoperative bleeding, recovery time, and findings at postoperative follow-up at one month, three months, and six months after surgery were recorded. Assessment included the two-point discrimination test, the grip and pinch strength test, the visual analog scale (VAS) score for pain, the Levine questionnaire, and Kelly’s therapeutic evaluation.

Results

Incision length, duration of surgery, intraoperative bleeding, and recovery time were significantly reduced in the wrist arthroscopy group and the small incision surgery group compared with the conventional surgery group (p<0.05). There were no significant differences in the two-point discrimination or grip and pinch strength test (p>0.05). Postoperatively, at one month, the VAS score, Levine score, and Kelly’s therapeutic evaluation in the wrist arthroscopy group and the small incision surgery group were significantly lower compared with the conventional surgery group (p<0.05). Scar length and scar tenderness in the conventional surgery group were significantly increased compared with the wrist arthroscopy group and the small incision surgery group (p<0.05).

Conclusions

Wrist arthroscopy, small incision surgery, and conventional open carpal tunnel release surgery were effective for the treatment of carpal tunnel syndrome, but conventional surgery resulted in more postoperative complications.