A simple foot pedal device in a horizontal bore imaging facility replicates weightbearing outcomes for Hallux Valgus patients.

BACKGROUND: Weightbearing images are important to the diagnosis of foot pathologies as are the three dimensional views available from CT and MRI. Standard three-dimensional imaging hardware, however, does not have a simple tool to obtain weightbearing images. The current research aimed to design, build and test a simple device to apply load in a horizontal bore imaging facility. METHODS: With the immediate need in hallux valgus studies, hallux valgus subjects were imaged using the new loading device, which could be easily transported and had no additional electronics. RESULTS: Testing showed that the usual angular measures of the foot (intermetatarsal and hallux valgus) replicated the results from the standard of care standing plain film results. With application of load, HV angle changed from 29.9° non-weightbearing to 32.2° weightbearing, while IM angle changed from nonweightbearing 15.8° to weightbearing 16.5°. CONCLUSION: The pedal-like device can provide weightbearing images in a horizontal bore MRI facility.

Weight-bearing recommendations after first metatarsophalangeal joint arthrodesis fixation: a biomechanical comparison.

BACKGROUND: This study sought to determine whether several metatarsophalangeal (MTP) fusion techniques require complete immobilization or if some level of weight-bearing could be recommended after surgery. A comparison of synthetic composite to actual bone was included in order to examine the validity of the testing conditions. METHODS: Four MTP fusion modalities were tested in synthetic composite bone models: unlocked plating, locked plating, crossed lag screws, and an unlocked plate with a single lag screw. Stiffness was calculated and then used to find the two most rigid constructs; the load to failure was recorded. Stiffness and load to failure testing for the two more rigid constructs in paired cadaveric bones were followed. RESULTS: The unlocked plate plus screw and crossed screw constructs were stiffest (p < 0.008). Loads to failure of the unlocked plate plus screw and crossed screws in synthetic bone were 131 and 101 N, respectively and in cadaveric bone were 154 and 94 N, respectively, which are less than the estimated 25% body weight required at the MTP joint. The plate plus screws were statistically more stiff than crossed screws (p = 0.008), but there was no statistical difference between synthetic and cadaveric bone in load to failure (p = 0.296). CONCLUSIONS: The plate plus screw offered the greatest stiffness; the failure test showed that no construct could withstand weight-bearing as tolerated; and, synthetic composite models of the MTP joint did not provide the consistent results in stiffness and failure.

[The AGILITY ankle: mid- and long-term results]. / Die AGILITY-sprunggelenkprothese: mittel- und langfristige erfahrungen.

The AGILITY ankle has been clinically used for over 20 years and between the two authors, a total of 1,075 AGILITY ankles have been inserted. Beside concept and design of this unique ankle prosthesis, specific follow-up data will be presented on 775 implants performed by the first author (FGA). The AGILITY Ankle System can give reliable and predictable results if the surgeon is aware of the complexity of this operation and the need for careful postoperative monitoring. Many of the failures that have occurred in the Agility System can be prevented by early detection (i.e., syndesmotic nonunion, hindfoot valgus, fractures, etc.) and if the problem is corrected, the implant can be maintained. The new LP System will also add another dimension to the overall adaptability of the prosthesis for an additional broader base of patients.

Midfoot osteotomies.

Midfoot osteotomies are primarily used for reconstructive procedures for congenital or acquired deformities. Although used more in a younger population, they can used in most any patient population. With restoration of a more normal architecture, patients' symptoms resolve and prevention of long-term sequella can be avoided. Careful evaluation is necessary, but with proper use, midfoot osteotomies are useful procedures in the foot and ankle surgeons' repertoire.

Complications of total ankle replacement.

Total ankle arthroplasty is emerging as a viable treatment for patients with symptomatic tibiotalar arthritis who have not responded to nonoperative treatment. First generation ankle replacement prostheses had significant complications, leading many orthopaedic surgeons to abandon their use. Second generation designs have attempted to address some of these problems with innovative new designs. Ankle arthritis differs from other forms of degenerative arthritis in that the majority is posttraumatic in origin, and occurs in a younger age group. Correction of alignment is complicated by deformity of the foot distal to the ankle. Published results of second generation ankle replacement systems are limited, and the understanding of them is necessarily anecdotal. In the current study, complications of current second generation total ankle arthroplasty are divided into preoperative or patient selection problems, complications related to prosthetic design, intraoperative, and postoperative complications. Solutions, or the controversies surrounding those complications that have no obvious solution, will be discussed when appropriate. Total ankle arthroplasty with these second generation prostheses is gaining increasing popularity. The surgeon contemplating total ankle arthroplasty should have an understanding of anatomy and lower extremity biomechanics, and a thorough knowledge of the total ankle system he or she decided to use.

Wound-healing risk factors after open reduction and internal fixation of calcaneal fractures: does correction of Bohler's angle alter outcomes?

The study reviewed in this article evaluated a group of patients who underwent surgical therapy for calcaneal fractures at a Level I trauma center. One group of patients was treated after outpatient referral to the center, whereas the other group was admitted to, and underwent surgery at, the center. This study attempted to determine which patient risk factors or injury characteristics might lead to an increased rate of wound-healing complications. Bohler's angle is a classic radiographic method of determining the severity of calcaneal injury in this group of patients. The question posed by the authors of this study was: Does a drastic correction in Bohler's angle lead to an increased incidence of wound-healing complications? The authors do not recommend undercorrection of Bohler's angle but urge avoidance of overcorrection and stress the importance of early surgical fixation after lateral skin wrinkling is found.

Ankle arthrodesis: indications and techniques.

Patients with ankle arthritis and deformity can experience severe pain and functional disability. Those patients who do not respond to nonoperative treatment modalities are candidates for ankle arthrodesis, provided pathologic changes in the subtalar region can be ruled out. Several techniques are available for performing the procedure; the most successful combine an open approach with compression and internal fixation. The foot must be positioned with regard to overall limb alignment and in the optimal position for function. A nonunion rate as high as 40% has been reported. Osteonecrosis of the talus and smoking are known risk factors for nonunion. When good surgical technique is used in carefully selected patients, ankle arthrodesis can be a reliable procedure for the relief of functionally disabling ankle arthritis, deformity, and pain.

Retrograde drilling of osteochondral lesions of the medial talar dome.

Sixteen patients (16 ankles) with symptomatic osteochondral lesions of the medial talar dome were treated arthroscopically with percutaneous retrograde drilling through the sinus tarsi. The surgical technique allows preservation of intact articular cartilage, in contrast to traditional methods. All patients treated with this technique during a 24-month period were included in the study. Patient age ranged from 16 to 44 years (mean, 33 years). Follow-up ranged from 19 to 38 months (mean, 24 months). A staging system based on magnetic resonance imaging examination was used to grade the lesions preoperatively. Outcome was evaluated using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. Preoperative scores ranged from 35 to 75 points, with a mean of 53.9 points. Postoperative American Orthopaedic Foot and Ankle Society scores ranged from 48 to 100 points, with a mean of 82.6 points. Mean improvement was 25 points. There were no surgical complications. Short-term results were comparable to results reported with other available techniques.

Clinical outcome after subtalar arthroscopy.

We investigated the clinical outcomes of patients with specific symptoms and physical findings of subtalar pathology with nonspecific radiographic findings after subtalar arthroscopy. Preoperative workup included plain radiographs in all of the patients, magnetic resonance imaging in seven patients, and bone scan in six patients. Based on these studies, no patient had significant subtalar arthrosis. Twelve patients underwent subtalar arthroscopy. Clinical outcome was rated with the American Orthopaedic Foot and Ankle Society Hindfoot Score. Preoperatively, the score ranged from 54 to 75, with a mean of 60. Postoperative scores ranged from 53 to 85, with a mean of 71. The follow-up averaged 17.5 months. Preoperative magnetic resonance imaging and bone scan uniformly underestimated the degree of articular damage. There were no operative complications. Three patients improved their scores by 10 points or greater. Two of these patients had debridement of a cartilage flap to a stable base performed. The third patient had an arthroscopically assisted removal of a loose body. Three of the four patients whose scores decreased have progressed to subtalar arthrodesis. We conclude from this small series of patients that arthroscopy is the most accurate method of diagnosing subtalar articular cartilage damage, but that it has limited therapeutic benefit in the treatment of early degenerative joint disease.

Surgical treatment of neuroarthropathic foot deformity.

Twenty-seven feet with neuroarthropathic fracture resulting in significant deformity were treated with surgical reconstruction. The average age of the patients was 57 years with 21 patients having diabetes mellitus an average of 24 years. Five patterns of midfoot collapse were identified. The most common patterns involved abduction and dorsal displacement of the forefoot with equinus of the hindfoot. Preoperative evaluation included a medical assessment, adequate control of blood sugar, and a comprehensive vascular evaluation. Five patients presented for surgical consultation with open plantar ulcers. Four were healed with total contact casting alone whereas one patient required an exostectomy to heal the ulcer before surgery. After reconstruction, all feet had improvement in their weightbearing posture. For feet with midfoot involvement, the average anteroposterior talo-first metatarsal angle increased 5 degrees, and the average lateral talo-first metatarsal angle decreased 6.5 degrees. There was no significant loss of correction at long term follow-up. The average time in a cast postoperatively was 5.7 months, and the time to unrestricted weightbearing was 7 months. All patients were able to wear over-the-counter footwear postoperatively. Significant complications included six nonunions and two feet with extension of the neuroarthropathic process. One nonunion required revision surgery, and the feet with extension of their neuroarthropathic fractures required conversion of a triple arthrodesis to a pantalar fusion and the addition of a triple arthrodesis after a successful midfoot fusion. No infections or amputations occurred as a result of the surgery. Function increased and pain decreased as a result of successful arthrodesis. Surgical reconstruction of midfoot, hindfoot, and ankle neuroarthropathic deformity is a viable alternative to amputation for patients who fail nonoperative care. Proper preoperative evaluation and assessment will result in a rate of complications comparable to foot surgery in nondiabetic patients.

Wound-healing risk factors after open reduction and internal fixation of calcaneal fractures.

This retrospective study investigated outcomes of wound healing in a series of 63 consecutive patients with 64 fractures of the calcaneus who underwent open reduction and internal fixation done by two surgeons experienced in this fracture during a 3-year period. Thirty-nine patients were managed preoperatively as outpatient referrals before surgery. Twenty-four patients were admitted directly to the trauma service and were managed as inpatients preoperatively. Minimum patient follow-up was 6 months, with an average follow-up of 18 months. A trend correlating the time between injury and operative intervention with the incidence of complications in wounds was noted; the incidence rose in patients who underwent surgery >5 days after their injury. Two-layered closures had a lower incidence of dehiscence compared to single-layered tension-relieving sutures. Patients with a higher body-mass index (BMI) (kg/ m2) took longer to heal their wounds. Strong trends were noted to link BMI and severity of fractures. In the outpatient group, a history of active smoking preoperatively correlated with increased time to wound healing. In 43 patients, there were no wound-healing complications. In 21 feet, there were varying degrees of wound dehiscence. Average wound healing took 47 days. Risk factors for complications in the wound after calcaneal open reduction and internal fixation include single layered closure, high BMI, extended time between injury and surgery, and smoking. Age, type of immobilization, medical illness (including diabetes), type of bone graft, or use of a Hemovac did not influence wound healing.

Anterolateral soft-tissue impingement in the ankle: diagnosis using MR imaging.

OBJECTIVE: This study was performed to elucidate the MR imaging findings and pitfalls for the diagnosis of anterolateral soft-tissue impingement in the ankle, a cause of chronic ankle pain that can be relieved by arthroscopic resection. MATERIALS AND METHODS: We retrospectively reviewed MR imaging examinations of 18 patients with arthroscopically confirmed anterolateral ankle impingement. The MR images of 18 additional subjects with symptoms that could mimic anterolateral impingement, but who had a surgically confirmed alternate diagnosis (instability, peroneal tendon injury, osteochondral defect, normal arthroscopy) and no evidence of impingement at arthroscopy, served as controls. RESULTS: On the MR imaging studies, nine patients had an ankle effusion, eight of whom showed an abnormal soft-tissue structure in the anterolateral gutter, 2-15 mm in maximal diameter. No soft-tissue mass was seen in the patients without joint fluid. Four control subjects with instability had a similar soft-tissue structure in the anterolateral gutter, but in the control subjects the finding represented a portion of the torn anterior talofibular ligament. CONCLUSION: Anterolateral soft-tissue impingement of the ankle can be suggested by MR imaging when fluid in the lateral gutter outlines an abnormal soft-tissue structure separate from the anterior talofibular ligament.

Plantar pressure measurements during ambulation in weightbearing conventional short leg casts and total contact casts.

Total contact casts have been shown to be effective in healing plantar neuropathic ulcerations. The proposed mechanism of action is reduction of pressure over the ulcer during ambulation. However, there is little information to support this contention. Plantar pressure distribution was studied using standard short leg casts and total contact casts in normal feet. Both types of casts reduced forefoot pressure in study subjects. This occurred because of an increase in plantar surface area exposed to weightbearing forces. While increased force was shifted to the midfoot, there was no increase in pressure due to a corresponding increase in midfoot surface area exposed to this force. No significant difference was noted between standard short leg casts and total contact casts.

Plantar pressure analysis of diabetic rockerbottom deformity in total contact casts.

In a previous study, we examined plantar pressures under normally arched individuals in casts. The investigation described in this article was designed to assess plantar pressure distribution in subjects with Charcot midfoot collapse and rockerbottom deformity in standard short leg casts and total contact casts. Our results show that both types of casts significantly reduced midfoot pressures. No significant differences were noted between the two casting groups.

Results of distal tibial bone grafting in hindfoot arthrodeses.

Distal tibial bone grafting is a safe and effective means of obtaining cancellous bone for hindfoot arthrodesis procedures, providing a sufficient quantity and quality of cancellous bone graft. Fusion rates using this bone graft are no less than those reported in the literature using autologous bone obtained from other sites. The 1% significant complication rate (fracture) of the donor site is low. Relative contraindications to the procedure include concomitant clinically significant peripheral neuropathy and severe osteopenia. Since cortical bone is not available from the distal tibia, procedures requiring corticocancellous strut or block grafts cannot rely solely on distal tibial grafting, although this procedure can be used to supplement iliac crest grafting when necessary.

Tarsal tunnel syndrome caused by an anomalous muscle.

We report the cases of six patients (seven feet) who had tarsal tunnel syndrome in association with an anomalous muscle that was located deep to the flexor retinaculum of the ankle. An accessory flexor digitorum longus muscle was present in six of the ankles and a tibiocalcaneus internus muscle, in one. All of the patients had a release of the tarsal tunnel and a neurolysis of the posterior tibial nerve and its branches in addition to a resection of the anomalous muscle. The duration of follow-up averaged forty-one months (range, twenty-eight to eighty-three months). Although the pain was reduced in four of the six patients, only one patient was completely free of symptoms at the time of the most recent follow-up examination. Four of the six patients were satisfied with the result of the operation.

Anomalous tibial nerve. A case report.

A rare anomaly of a nonterminating tibial nerve is reported. It was found to be associated with tarsal tunnel syndrome. The nerve failed to divide in the tarsal tunnel and in the talocalcaneal canal distally to the Knot of Henry. The branches of the medial and lateral plantar nerves as well as the medial calcaneal nerve, the nerve to the abductor digiti quinti, and motor branches to the abductor hallucis and to the joints, vessels, and skin took origin directly from the tibial nerve. The presence of this nerve anomaly and its relevance to surgery in the posterior ankle region is discussed. Surgeons should be aware of this anomaly to avoid the inadvertent cutting of nerve branches they assume to be of a non-critical nature.