Subclinical neuropathy in diabetic patients: a risk factor for bilateral lower limb neurological deficit following spinal anesthesia?

Total knee arthroplasty performed under spinal or general anesthesia is a common successful orthopedic procedure. Nonetheless, in patients with diabetes mellitus this procedure can present unique challenges to orthopedic surgeon and anesthesiologist alike. We describe a case of an elderly male diabetic patient who developed bilaterally symmetrical lower limb neurological deficit following an uneventful total knee arthroplasty performed under spinal anesthesia. Postoperative nerve conduction study with electromyography confirmed symmetrical extensive denervation of lower limb muscles, including low-voltage fibrillation potentials and positive sharp waves. These findings were consistent with a preexisting neuropathy, thereby suggesting a subclinical neuropathy as a potential risk factor for this neurological complication. Our case highlights the fact that patients with longstanding comorbidities, namely peripheral vascular disease and diabetes mellitus, may be at an increased risk of neurological injury following regional anesthesia. Hence, we believe that preoperative evaluation of diabetic patients should include neurophysiological studies to identify subclinical neuropathy and minimize the risk of neurological injury.

Lower limb elevation: useful and effective technique of exsanguination prior to knee arthroscopy.

The use of a Rhys-Davies (R-D) mechanical exsanguinator prior to the application of tourniquet is routine clinical practice in knee arthroscopy. However, this technique has been reported to cause injuries and is contraindicated in conditions like malignancy and latex allergy. Lower limb elevation alone has also been described as a technique of exsanguination. We conducted a prospective audit of two groups of patients (25 each) undergoing routine knee arthroscopy comparing the practice of mechanical exsanguination (R-D) with lower limb elevation technique. Average total operative times of the two groups were similar (R-D exsanguinator-23 min, limb elevation-21 min, n.s). Time interval between tourniquet inflation and skin incision was significantly lower in limb elevation technique (R-D exsanguinator-5 min, limb elevation-0.2 min, P < 0.001). Limb elevation technique of exsanguination helps avoid the risks associated with mechanical exsanguination and may potentially reduce the non-operative tourniquet application time.

Tibialis posterior tendon and deltoid and spring ligament injuries in the elite athlete.

The tibialis posterior tendon and the spring and deltoid ligament complexes combine to provide dynamic and passive stabilization on the medial side of the ankle and hindfoot. Some of the injuries will involve acute injury to previous healthy structures, but many will develop insidiously. The clinician must be aware of new treatment strategies and the level of accompanying scientific evidence regarding injuries sustained by athletes in these areas, while acknowledging that more traditional management applied to nonathletic patients is still likely to be appropriate in the setting of treatment for elite athletes.