Surgical Planning for Flexor Digitorum Longus Tendon Transfers: An Anatomic Study.

Posterior tibial tendon dysfunction is often coupled with various degrees of hindfoot valgus and equinus. Preoperative planning is essential to appropriate procedure choice and surgical efficiency. The purpose of the present study was to assess the anatomy at the harvest site for flexor digitorum longus tendon transfer, specifically at the master knot of Henry. Thirty fresh-frozen below-the-knee cadavers were used for dissection. A standard anatomic approach was performed for posterior tibial tendon debridement and flexor digitorum longus tendon transfer. The flexor digitorum longus tendon was harvested and measured at the master knot of Henry. The present anatomic study evaluated the tendon width of the flexor digitorum longus tendon at a common harvest site. Of the 30 specimens, 20 (67%) measured 5 mm and 10 (33%) measured 4 mm. A 5.0-mm interference screw would be acceptable in each specimen and therefore would be the safest choice. A 4.0-mm interference screw would be acceptable in only 33% of the specimens. Males have a slightly more robust flexor digitorum longus tendon than females at the harvest site. This information will assist surgeons in preoperative planning during stage II flatfoot correction for posterior tibial tendon dysfunction.

Anterior Approach Total Ankle Arthroplasty: Superficial Peroneal Nerve Branches at Risk.

In ankle arthroplasty, little attention has been given to intraoperative nerve injury and its postoperative sequelae. The aim of the present anatomic study was to determine the relationship of the superficial peroneal nerve to the standard anterior approach for total ankle arthroplasty. The superficial peroneal nerve was dissected in 10 below-the-knee cadaver specimens. The medial and intermediate dorsal cutaneous branches were identified. A needle was placed at the ankle joint. The following measurements were recorded: bifurcation into the medial and intermediate dorsal cutaneous branches, reference needle to the branches of the medial and intermediate superficial peroneal nerve, and the crossing branches of the medial dorsal cutaneous nerve. Two specimens (20%) had a medial dorsal cutaneous branch cross from medially to laterally. Eight specimens (80%) had a crossing branch of the medial dorsal cutaneous branch within 5 cm of the incision. No intermediate dorsal cutaneous branches were within the incision. The results from the present cadaver study suggest that during an anterior ankle approach, aberrant branches of the superficial peroneal nerve could require transection in 20% of patients at the joint level and ≤80% of patients with distal extension >35 mm from the ankle joint. The risk of injury to branches of the superficial peroneal nerve is substantial. The risk of nerve injury can be decreased with meticulous operative technique, smaller incisions, and the avoidance of aggressive retraction.

Assessment of Bone Marrow Aspiration Site Pain in Foot and Ankle Surgery.

UNLABELLED: Bone marrow aspiration (BMA) is a validated technique to harvest progenitor cells. BMA has many uses in foot and ankle surgery; however, donor site morbidity is a concern. The purpose of this study was to compare the Visual Analog Scale (VAS) pain scores after BMA at 3 different sites (iliac crest, distal tibia, and calcaneus) over a 12-week postoperative recovery period. This was an institutional review board-approved prospective study of 40 patients who underwent BMA as an adjunct to their primary foot and ankle procedure. Each patient had BMA harvested from the ipsilateral anterior iliac crest, distal tibia, and lateral calcaneus at the time of surgery. Patient follow-up questionnaire forms were filled out at 2, 4, 8, and 12 weeks, with the primary outcome measure being VAS pain scores. Mean VAS scores averaged over the 12-week follow-up period were significantly higher in the calcaneus (20.8 ± 28.6) compared with the distal tibia (7.7 ± 17.6) and the iliac crest (4.2 ± 12.4; P < .05). No significant difference was found between the distal tibia and the iliac crest sites. At 12 weeks, all sites were about equal and without appreciable pain. Our data suggested that donor site selection for BMA affects postoperative pain levels, with BMA from the calcaneus resulting in significantly higher pain scores when compared with the iliac crest or distal tibia. The VAS pain score for the calcaneus was likely confounded by the high number of hindfoot/ankle surgeries performed in the ipsilateral foot. LEVELS OF EVIDENCE: Therapeutic, Level II: Prospective, comparative trial.

Injury to the Posterior Tibial Tendon After Open Reduction Internal Fixation of the Medial Malleolus.

UNLABELLED: The management of ankle fractures with open reduction and internal fixation (ORIF) has been a proven method to help prevent deformity and posttraumatic arthritis. The incidence of continued ankle pain due to retained hardware after ORIF of ankle fractures has been documented. The goal of this study was to determine if the starting point for medial malleolus screw placement is associated with posterior tibial tendon (PTT) damage when performing ORIF of the medial malleolus. Patients that had ORIF of the medial malleolus and subsequent repair of the PTT with medial malleolar hardware removal were identified. Zones were established and labeled 1 through 3 as described in the literature. This template was used as an overlay on lateral ankle radiographs to analyze the position and assign zones to the medial malleolus screws. Fifteen patients met the inclusion criteria. Three screws were found in zone 1, 11 in zone 2, and 1 in zone 3. The middle and posterior zones (zones 2 and 3) contained 80% of the screws, which may potentially cause risk to the PTT. We conclude that there is an increased probability that medial malleolar hardware in zones 2 and 3 can compromise the PTT. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case series.

Quantification of Subtalar Posterior Facet Involvement During Intramedullary Guidance of Total Ankle Arthroplasty:A Cadaveric Study.

Total ankle arthroplasty is an evolving treatment of ankle arthritis. One implant uses intramedullary guidance to enhance accuracy by accessing the tibial canal through the inferior aspect of the foot, potentially placing the subtalar joint articulation at risk. The purpose of the present cadaveric anatomic evaluation was to identify posterior subtalar articular facet joint involvement during intramedullary guidance to the tibial canal. Ten below-the-knee cadaveric specimens were used. After drilling into the tibial medullary canal with a 6-mm drill bit and using the standard targeting jig, the specimens were dissected, and the posterior facet was evaluated. We graded posterior facet involvement according to the location of the drill hole and, if within the facet, the percentage of the facet violated by the drill bit, with 100% representing the full circumference of the 6-mm drill bit. Of the 8 specimens in which the drill bit passed through the subtalar posterior articular facet, the encroachment was peripheral in all cases, with no specimen showing circumferential 6-mm drill bit articular penetration (no cases with 100%). Sinus tarsi penetration occurred in 20% of the cases. The dissections with articular involvement included 3 specimens with >50% of the drill bit penetrating and 5 with <50%. The portion of the posterior facet involved among the specimens that were violated was anterocentral in the joint. A risk of damage to the posterior facet of the subtalar joint exists with intramedullary total ankle systems. Our study has demonstrated that the drill bit will involve the anterocentral and anterolateral portions of the posterior facet of the subtalar joint, with <6 mm articular disruption in all cases.

Screw fixation diameter for fifth metatarsal jones fracture: a cadaveric study.

The fifth metatarsal Jones fracture is a well-documented injury occurring at the proximal diaphyseal-metaphyseal junction. Conservative versus surgical intervention has been discussed in published studies for the management of Jones fractures. Solid intramedullary fixation relies on accurate matching of the screw diameter to the intraosseous diameter. The purpose of the present cadaveric study was to determine the average intraosseous diameter of the proximal fifth metatarsal as it relates to screw size selection for Jones fracture stabilization. Twenty fresh-frozen cadaver legs were used for examination. The fifth metatarsal was completely dissected. A transverse osteotomy was performed from laterally to medially along the midline of the metatarsal. A digital caliper was used to measure the diameter of the medullary canal of the fifth metatarsal. The measurement was taken at the narrowest portion of the medullary canal just distal to the proximal metaphysis. The mean dorsal to plantar diameter of the fifth metatarsal was 6.475 ± 1.54 (range 4 to 12) mm and the mean medial to lateral diameter was 4.6 ± 0.85 (range 3 to 6) mm. Intramedullary screw fixation has shown beneficial results in the treatment protocol of fifth metatarsal Jones fractures. Our study has demonstrated that a 4.5-mm cannulated screw is the narrowest diameter screw that can be used in the average fifth metatarsal and still obtain adequate intraosseous purchase. When selecting the appropriate screw, the surgeon must be comfortable selecting the largest screw that will achieve the maximal interface with the dense cortical bone in both the medial to lateral and dorsal to plantar plane.

Safety analysis of cryopreserved amniotic membrane/umbilical cord tissue in foot and ankle surgery: a consecutive case series of 124 patients.

Cryopreserved amnion tissues derived from amniotic membrane/umbilical cord (AM/UC) have been used extensively in ophthalmology for minimizing postoperative inflammation, pain, and adhesion formation following various surgical procedures. There is limited data in the current literature regarding the use of amnion tissue product in foot and ankle surgery. The purpose of this retrospective study is to report the short-term safety profile after in vivo application of cryopreserved AM/UC tissue use in foot and ankle surgery. A retrospective consecutive case series was performed for cases where amnion tissue was used with a minimum follow-up of 120 days between 2011 and 2012. The clinical outcomes of interest were postoperative infections, delayed or nonhealing wounds, adverse surgical site reactions, and repeat surgery for formal irrigation and debridement. One hundred twenty-four patients qualified for inclusion. Cryopreserved AM/UC tissue was introduced into the surgical wound and placed adjacent to the compromised and repaired tendons, most frequently in peroneal and Achilles tendon repairs. In this level IV consecutive case series cohort, there was an overall wound complication rate of 5.64%, with a re-operation rate of 1.6% (2/124). In each of these cases, patients had an irrigation and debridement with ultimate successful wound healing. The results of this study demonstrate that the use of amnion tissue in the foot and ankle setting is safe with a decreasing trend in overall complication rates compared with historically published norms.