1. 0.045-Inch K-wire is the optimum size for fixation of digital procedures. Although podiatrists commonly use 0.045-inch K-wires in digital surgery, the orthopedic community favors larger sizes such as 0.054 and 0.062 inches. Perhaps this is inherent to the “bigger is better” mentality commonly demonstrated with fixation of fractures and osteotomies throughout the body.
We often utilize a 0.054-inch device when treating male patients who have a larger bone diameter. This is particularly the case when we are fixating an end-to-end arthrodesis that lacks inherent stability seen with dowel fusion techniques. Also, when you’re treating patients who have compliance issues, a 0.054-inch device (or in rare instances a 0.062-inch device) provides peace of mind while enhancing outcome. Using larger K-wires minimizes micro-motion at the arthrodesis interface and decreases stress fatigue.
2. You must perform osseous work to correct a mallet toe deformity. Performing a simple flexor tenotomy and capsulotomy provides adequate correction for geriatric patients who have flexible to semi-rigid contracture at the distal interphalangeal joint. This technique coupled with appropriate splinting allows the digit to heal in a rectus position. Typically, this requires four weeks for stability. Be aware there may be decreased distal toe purchase postoperatively, which may be of concern in older patients with proprioceptive deficiencies. However, you should be able to determine this in the preoperative evaluation.
3. Fixation of end-to-end proximal interphalangeal arthrodesis for four weeks is sufficient. It is important to retain K-wire fixation for at least six weeks following an end-to-end arthrodesis. Failure to do so may result in pseudoarthrosis or nonunion of the middle and proximal phalanges. Removing fixation prematurely may place patients at risk for recurrence of their digital deformity as the fibrous union is often not sufficient to resist deforming forces of the tendinous structures crossing the joint. We have found fixation for six weeks generally results in stable osseous union in a higher percentage of patients, if you employ the correct technique in joint preparation.
4. Pallor following digital surgery is self-limiting and need not be treated. Digital arthrodesis in severe hammertoe deformities results in significant tension placed on neurovascular structures. Pay particular attention to longstanding rheumatoid forefoot deformities and severe extensor substitution hammertoes seen in the cavus foot type. Vessels which have contracted over a period of time are at risk for arterial spasm. This will lead to a white/gray hue in the digit. This should be distinguished from venous congestion, which presents as a bluish discoloration of the toe. Venous congestion is self-limiting and need not be treated.
Digits often fail to “pink-up” in the recovery room. It is important to have a logical treatment sequence to rectify the problem. Often, simply loosening a restrictive dressing will allow circulation to return to the digit. Warm blankets and dependency are also viable first-line conservative treatments. If these treatments fail to yield results, you should rotate the K-wire within the toe to decrease tension on the soft tissue structures surrounding the phalanges. You may use a calcium channel blocker, such as nifedipine, to decrease vasospastic tendencies in the digital arteries.
Should the digit fail to respond to conservative measures, remove the K-wire. Pending a lack of response, bring the patient back to the operating room for suture removal and wound exploration.
5. Never use epinephrine in digits. A popular misconception is it is unsafe to use local anesthetic with epinephrine for digital blocks during surgery. In theory, epinephrine will cause arterial vasospasm, leading to a shutdown of circulation in the digit. Yet recent allopathic literature confirms past podiatric experience regarding the safety of epinephrine when you use it appropriately.13
Proper patient selection is very important. In elderly patients with poor circulation, avoid epinephrine. Consider systemic diseases such as Raynaud’s or Beurger’s disease that often affect the young, seemingly healthy patient. Be sure to obtain a comprehensive medical history prior to considering its use. Also be aware that epinephrine potentially poses a significant systemic threat to hypertensive patients.
We routinely use local anesthetic with dilute epinephrine for digital anesthesia. For healthy patients who have uncompromised circulation, this has proven to be an effective means of hemostasis. Using epinephrine has allowed patients to undergo procedures under local anesthesia without the discomfort of a pneumatic ankle tourniquet. When following these guidelines, epinephrine is a safe, useful agent that facilitates hemostasis. The combined experience of our staff surgeons includes several thousand digital surgeries using epinephrine without a single circulatory failure.