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The Journal of Bone and Joint Surgery (American). 2008;90:928-942. doi:10.2106/JBJS.G.01289 © 2008 The Journal of Bone and Joint Surgery, Inc. What's New in Foot and Ankle Surgery
1 Department of Orthopedics, University of Miami, P.O. Box 016960 (D-27), Miami, FL 33101
Specialty Update has been developed in collaboration with the Council of Musculoskeletal Specialty Societies (COMSS) of the American Academy of Orthopaedic Surgeons.
This update summarizes recent research pertaining to the subspecialty of orthopaedic foot and ankle surgery that was published or presented between August 2006 and July 2007. The sources of these studies include The Journal of Bone and Joint Surgery (American and British Volumes), Foot and Ankle International, and the proceedings of Specialty Day at the annual meeting of the American Academy of Orthopaedic Surgeons (AAOS), held on February 17, 2007, in San Diego, California; and the summer meeting of the American Orthopaedic Foot and Ankle Society (AOFAS), held on July 13, 14, and 15, 2007, in Toronto, Ontario, Canada.
Supination-external rotation is the most common mechanism of injury producing ankle fractures. Operative intervention after a lateral malleolar fracture is guided by the integrity of the medial ankle structures (the medial malleolus or the deltoid ligament). In a prospective study, Gill et al. compared manual and gravity stress radiographs for the detection of deltoid ligament injury after isolated supination-external rotation-type fibular fractures1. Twenty-five patients (including thirteen with supination-external rotation type-II fractures and twelve with supination-external rotation type-IV fractures) were enrolled in the study. In each patient, measurements of talar shift and medial clear space produced by both stress techniques were found to be equivalent for each variable. Significant differences were noted in medial clear space measurements between the supination-external rotation type-II and type-IV fracture groups, showing that both manual and gravity stress radiographs were able to effectively demonstrate deltoid ligament incompetence. Furthermore, for the supination-external rotation type-IV fractures, both stress radiograph techniques demonstrated a mean medial clear space of >5 mm and a mean talar shift of >2 mm. Pinzur et al. reported comparable results in a similar study of twenty-nine patients with isolated supination-external rotation-type fibular fractures2. In addition to assessing medial ligament integrity, the authors recorded the visual analog score for pain after each stress examination. A significant difference in pain was noted between manual and gravity stress examinations, confirming that patients perceive less pain with gravity stress testing. The study suggests that gravity stress examination may replace manual testing as a screening tool for the diagnosis of unstable supination-external rotation-type ankle fractures because of its high sensitivity and relative patient comfort. Moore et al. performed a prospective surgeon-randomized study that compared the clinical results associated with the use of three and four cortices of screw fixation for the treatment of syndesmotic ankle disruptions3. One hundred and twenty-seven patients with Orthopaedic Trauma Association (OTA) type 44-C fibular fractures with fluoroscopically confirmed tibiofibular instability received one 3.5-mm fully threaded cortical syndesmotic screw placed through a one-third tubular plate with either three or four cortices of purchase. With the relatively limited numbers available in the study, statistical analysis showed no significant difference between three and four cortices of fixation with regard to loss of reduction, screw breakage, or the need for hardware removal. A trend toward greater loss of reduction was noted in the group with three cortices of fixation, but all patients with loss of reduction were noncompliant with postoperative weight-bearing restrictions. Radiolucency around the syndesmotic screw was found in 53% and 59% of the patients in the three and four-cortex fixation subgroups, respectively. Retention of syndesmotic implants despite fixation failure did not appear to be clinically problematic, and the authors advised against the routine removal of syndesmotic screws. Siegel and Tornetta reported on their technique and outcomes with extraperiosteal plating of stage-III pronation-abduction ankle fractures4. This mechanism of injury is characterized by a comminuted lateral fibular cortex, which may compromise the fibular endosteal blood supply. Previous series have demonstrated the need to augment these defects with bone graft as well as high rates of nonunion in cases in which bone graft was not used. In contrast to the standard technique of open fracture reduction with some degree of periosteal splitting, the authors' technique leaves the surrounding soft-tissue sleeve intact. A precontoured nonlocking, one-third tubular plate was placed superficial to the periosteum and was used in a manner similar to that of a bridge-plate that spans the comminuted lateral fibular cortex. The plate also functioned as an indirect reduction tool, with the periosteum and soft-tissue envelope being used to assist in reduction of the fibular fracture fragments and for restoration of fibular length. Syndesmosis screws were placed through the plate, and medial malleolar fixation was performed as the fracture pattern dictated. Thirty-one patients with stage-III pronation-abduction ankle fractures were managed with this operative technique. All fibular fractures healed without displacement by ten weeks, and no bone-grafting was performed. The average AOFAS score was 82, with a mean ankle dorsiflexion of 13° and a mean plantar flexion of 31°. The authors recommended this technique for the treatment of comminuted pronation-abduction ankle fractures. Operative stabilization of the medial malleolus is commonly used for the treatment of displaced medial malleolar and unstable bimalleolar and trimalleolar fractures. Femino et al. performed a cadaver experiment to guide the placement of screws into the medial malleolus without disturbing the adjacent anatomy5. Using a triple guide, the authors placed three parallel Kirschner wires into the anterior colliculus (zone 1), the intercollicular groove (zone 2), and the posterior colliculus (zone 3). The wires were then overdrilled, and 4.0-mm partially threaded screws were inserted. The proximity of the screws and of the screw abutment to the nearby posterior tibial tendon and damage to the tendon were assessed after dissection. Zone 1 was deemed to be the safe zone because no screw in this area damaged or abutted tendon. Screws in zone 2 were located an average of 2 mm from tendon, and four of ten screws abutted the posterior tibial tendon. All screws placed in zone 3 contacted the posterior tibial tendon, and half of the specimens displayed tendon damage. There are currently no accepted methods for the evaluation of fibular torsional deformities after fixation of ankle fractures associated with syndesmotic disruption. Several studies have shown that postoperative plain radiographs lack the sensitivity to accurately detect subtle fibular subluxations or torsional malreductions. To compare torsional symmetry, Vasarhelyi et al. evaluated postoperative computed tomography scans of both ankles of sixty-one patients after fixation of ankle fractures that were associated with syndesmotic disruption6. The investigators found two valid and reproducible methods for evaluating fibular torsional deformity and correlated asymmetry of >10° with AOFAS scores. Applying these two methods, the authors reported fibular torsional asymmetry of >10° in thirty-five patients and asymmetry of >15° in eight patients. Functional outcome, as determined with the AOFAS score, was related to the degree of fibular torsion as measured with both computed tomography analyzing methods. The poorest clinical function was reported for patients with asymmetry of >15°. Tejwani et al. compared the epidemiologic characteristics and functional outcomes after the surgical treatment of the two types of supination-external rotation type-IV injuries: (1) distal fibular fractures with deltoid ligament rupture and (2) bimalleolar fractures7. Two hundred and thirteen patients were followed for at least one year postoperatively and were evaluated clinically and radiographically. Function was assessed with the Short Musculoskeletal Function Assessment (SMFA) score and the AOFAS score. Among the significant findings, bimalleolar fractures occurred most commonly in women, in patients older than sixty years, and in patients with the greatest number of comorbidities. Functionally, the bimalleolar fractures fared statistically worse at one year, but no significant difference in pain status was found between fracture subgroups. The authors concluded that the supination-external rotation type-IV variant with medial malleolar fracture is a more serious injury than its ligamentous counterpart and that it occurs more frequently in women and older patients.
Calcaneal stress injuries have been poorly characterized since the advent of magnetic resonance imaging as a primary diagnostic tool. Using this imaging modality, Sormaala et al. reported on the incidence, demographics, and anatomic distribution of calcaneal stress injuries in a large population of military recruits8. Their results revealed an incidence of 2.6 calcaneal stress injuries per 10,000 person-years and no differences in the demographic variables of recruits with and without calcaneal stress injuries. All areas of the calcaneus were affected, but injury occurred most frequently in the posterior one-third and superior one-half. Only 15% of the injuries that were confirmed with magnetic resonance imaging were originally found or suspected on plain radiographs. The high sensitivity of magnetic resonance imaging allowed detection not only of lower-grade calcaneal injuries that manifested as bone marrow edema but also of stress injuries of adjacent bones, most commonly the talus, navicular, and cuboid. The authors recommended acquiring a magnetic resonance imaging scan when a calcaneal stress injury is suspected despite a benign radiographic appearance. Anatomic reduction and fixation of Sanders type-II displaced intra-articular calcaneal fractures can improve outcomes by restoring function and lowering the risk of posttraumatic subtalar arthritis. In the study by Rammelt et al., the results of percutaneous reduction and screw fixation were compared with those of open reduction and internal fixation with a lateral plate through an extensile lateral approach9. Percutaneous reduction was performed under fluoroscopic and subtalar arthroscopic visualization, and fixation was achieved with use of 2.5-mm small-fragment screws. Both surgical approaches produced good-to-excellent subjective results, function, and restoration of the Bohler angle. The percutaneous reduction-screw fixation group had no wound complications, an earlier return to rehabilitation, and a significantly better hindfoot range of motion than did the plate fixation group. In the latter group, one patient had development of wound-edge necrosis that healed without complication. Many patients have development of considerable subtalar arthritis despite anatomic reduction and fixation of intra-articular calcaneal fractures. Ball et al. sought to demonstrate that the initial impact of the injury causes articular cartilage chondrocyte necrosis, which affects future subtalar arthritis10. Irreducible osteochondral fragments of calcaneal fractures were obtained intraoperatively for the assessment of chondrocyte viability and were compared with control cartilage obtained from donors who died from unrelated causes. Samples taken from patients with fractures demonstrated an average chondrocyte viability of 73% ± 13%, which was significantly lower than the value of 95% ± 1.5% found in controls. Strong trends that did not reach the level of significance were identified between lower chondrocyte viability and both the time from the injury to surgery and increasing patient age. The authors believed that their results provide a reason for subtalar arthritis despite an anatomic reduction after intra-articular calcaneal fractures. Smith et al., in a study of nineteen patients, reported the results of reimplantation of the extruded talus following pantalar dislocation or an associated talar fracture-dislocation11. The treatment of these injuries included immediate wound irrigation, administration of appropriate intravenous antibiotics, and reduction before the patient was transported to the operating room. When the extruded talus had no soft-tissue connections, it was placed in a bacitracin solution for transport to the operating room and then was washed successively in two or three baths of bacitracin solution prior to reimplantation. Stabilization was achieved with internal fixation, external fixation, or a combination of the two. Contrary to previous reports on the results of talar reimplantation, the infection rate was low, with the development of only one acute infection in a patient who underwent primary tibiocalcaneal arthrodesis; no patient had had a delayed amputation at the time of the latest follow-up. Because of the limited number of patients, no significant associations could be made. However, all cases involving an extruded talus in conjunction with a talar neck or body fracture subsequently were associated with the development of radiographic evidence of collapse, osteonecrosis, or arthritis. Reflecting the severity of the injuries, the average musculoskeletal functional assessment score was 29.8 (compared with the normal population value of 9.3), demonstrating permanent disability. The findings of this study suggest that the talus may be safely reimplanted, thereby preserving limb height and bone stock, joint mechanics, and the possibility of future reconstructive surgery.
In a cadaver study, Sides et al. compared the biomechanical properties of 6.5-mm partially threaded cancellous screws with those of 4 to 5-mm tapered variable pitch compression screws when used for the fixation of fifth metatarsal metaphyseal-diaphyseal junction (Jones-type) fractures12. Their goal was to determine differences between the two screws in terms of bending stiffness and pullout strength. While no differences in bending stiffness were identified, the 6.5-mm lag screw provided significantly higher resistance to thread pullout.
The complex anatomy and biomechanical properties of the distal tibiofibular ligaments are still being defined. Hoefnagels et al. were the first investigators to isolate and directly quantify the strength and stiffness of the interosseous tibiofibular ligament of the ankle, further elucidating its role in syndesmotic stability13. The interosseous ligament was found to be stronger and stiffer than the anterior inferior tibiofibular ligament, both in this study and in other investigations, underscoring the importance of the interosseous ligament in ankle syndesmotic stability. Chronic tibiofibular syndesmotic injuries present challenging diagnostic and treatment problems. The etiology of the associated ankle pain is incompletely understood but may be explained by one of two theories. The first theory equates pain with instability, whereas the second attributes the pain to impingement of hypertrophic soft tissue within the distal tibiofibular joint. In a prospective randomized study, Han et al. used a new magnetic resonance imaging technique known as contrast-enhanced, fat-suppressed, three-dimensional, fast gradient-recalled (CE 3D-FSPGR) acquisition in the steady state with radiofrequency spoiling to evaluate twenty patients with an arthroscopically diagnosed syndesmotic ankle injury for the presence of hypertrophic soft tissue in the syndesmosis14. All patients received arthroscopic marginal resection of hypertrophic tissue and then were randomized to receive transcortical syndesmotic screw fixation or marginal resection alone. Interestingly, two provocative tests of diagnostic value in acute syndesmotic injury—the external rotation stress test and the tibiofibular squeeze test—were positive in only two and three of the twenty patients, respectively. However, eighteen of the twenty patients experienced dull tenderness anteriorly over the syndesmosis on palpation. The magnetic resonance imaging technique showed a sensitivity of 90%, a specificity of 94.8%, and an accuracy of 93.4%. Patients who received syndesmotic screw fixation demonstrated improvement in AOFAS scores that was nearly equivalent to that of patients who received arthroscopic marginal resection alone. The authors concluded that the CE 3D-FSPGR magnetic resonance imaging technique may be helpful for diagnosing chronic distal tibiofibular syndesmosis injury and that pain could be related to impingement of hypertrophic soft tissue. Superficial peroneal nerve injury can cause residual morbidity following inversion ankle sprains. O'Neill et al. quantified the potential excursion and strain sustained by the superficial peroneal nerve during an inversion ankle sprain15. In a cadaver inversion ankle sprain model, they successively loaded the ankle before and after sectioning of the anterior talofibular ligament and after an impact force while measuring superficial peroneal nerve excursion and strain. They found significantly higher excursion and strain for all weights and after an impact force with the anterior talofibular ligament sectioned. The magnitude of strain recorded in the superficial peroneal nerve with the impact force was consistent with values demonstrated in other investigations to structurally alter peripheral nerves and may explain superficial peroneal nerve injury during inversion ankle sprains. Two related cadaver studies were performed to define the ligamentous attachments of the lateral talar process and to challenge the arbitrary value of 1 cm as the size of lateral talar process fractures causing ankle or subtalar joint instability. DiGiovanni et al. dissected cadaver ankles and measured the proximity of ligamentous attachments to the apex of the lateral talar process16. The results showed that only the lateral talocalcaneal, anterior talofibular, and posterior talofibular ligaments attach to the lateral talar process, contrary to the findings of some previous reports. Langer et al. excised a 1-cm3 fragment of the lateral talar process and then stressed the ankle and subtalar joints to measure radiographic signs of instability17. None of the measurements reached the value of standard accepted radiographic criteria for ankle or subtalar instability. This finding suggests that excision of lateral talar fracture fragments of 1 cm3 may not destabilize the ankle or subtalar joint nor require open reduction and internal fixation to confer stability.
Talar osteochondral lesions are commonly described as being located either anterolaterally or posteromedially on the talar dome. Raikin et al. developed an original nine-zone talar grid system by assigning three rows and three columns to the talus in an attempt to localize osteochondral lesions more accurately18. In that study, 428 lesions that had been identified with magnetic resonance imaging were reviewed, measured, and then relocalized by applying the authors' nine-zone grid system. Zone 4 (medial talar dome/middle row) was the most frequently involved location (53%), and zone 6 (lateral and middle) was the second most frequently involved location (26%). The traditional anterolateral and posteromedial locations only accounted for a combined 9% of lesions with use of the grid system. Finally, the results demonstrated that medial talar dome lesions are significantly larger and deeper than lateral lesions are. The authors proposed using their grid system as a more reproducible and accurate means of characterizing talar osteochondral lesions. Osteochondral lesions of the talus that remain symptomatic following arthroscopic débridement pose a particular therapeutic challenge. Savva et al. describe the results of repeat arthroscopic débridement alone, performed by the same surgeon applying the same technique, for twelve patients with persistent symptoms after the index procedure19. The average AOFAS score improved from 42 after the index procedure to 81 after repeat débridement, with two patients returning to professional sports. The pathologic findings at the time of repeat arthroscopy were areas of fibrocartilage that were of poor quality, partially loose, and incompletely healed. In cases of large talar osteochondral lesions, the extensive avascularity of the bone often prohibits successful transfer of autologous chondrocytes and bone plugs. Tanaka et al. reported satisfactory results for four patients with medial talar osteochondral defects (mean volume, 4.31 cm3) who were managed with a local vascularized bone graft20. Bone was harvested from the medial aspect of the calcaneus, with the calcaneal branch of the posterior tibial artery being used as the vascular pedicle. Most of the lesions required supplemental bone graft from the iliac crest to fill the void. The described technique also requires that there is residual cartilage overlying the lesion; no articular substitute is transferred into the lesion. Postoperative radiographs revealed sclerosis with no joint narrowing in all patients, and follow-up magnetic resonance imaging and computed tomography scans showed no osteonecrosis or recurrence of cysts. Finally, mean AOFAS scores improved from 60 to 83 after the procedure.
Saltzman et al. used validated outcome instruments to assess the degree of physical impairment associated with ankle osteoarthritis and the influence of systemic and unrelated musculoskeletal comorbidities on the perception of ankle pain and function21. Patients with primary and posttraumatic ankle osteoarthritis completed the Short Form-36 Physical Component Summary and Mental Component Summary questionnaire as well as Ankle Osteoarthritis Scale forms for comparison with matched controls. The results revealed that ankle osteoarthritis produced physical impairment equivalent to that reported for patients with severe medical problems such as end-stage renal disease, congestive heart failure, or cervical spine pain and radiculopathy. Patients with posttraumatic osteoarthritis had impairment similar to that of patients with primary ankle osteoarthritis but were an average of ten years younger. The number of concomitant unrelated musculoskeletal comorbidities was linked in a nearly linear fashion to the patient's perception of ankle pain and impairment. The authors suggested the need for future studies, using these outcome measures adjusted for unrelated musculoskeletal comorbidities, in order to discern the true impact of the disease being evaluated. The disability associated with end-stage ankle arthritis was compared with that associated with end-stage hip arthritis in a prospective study by Glazebrook et al.22. Two large cohorts of patients waiting for surgery for the treatment of either ankle or hip osteoarthritis were evaluated with the Short Form-36 questionnaire. All symptom-related and functional scores for both cohorts were significantly below normal population values. The ankle group was significantly worse in terms of mental component scores, physical limitation with work and daily activities, and general health. These results further underscored the severe disability of ankle osteoarthritis despite higher resource allocation for the treatment of hip osteoarthritis.
Interest in total ankle arthroplasty has increased as the search for viable alternatives to ankle arthrodesis continues and as newer generations of prostheses aim to improve on the failures of earlier models. Coetzee evaluated the three-year results associated with the Agility total ankle replacement (DePuy, Warsaw, Indiana)23. For the sixty-four ankles with complete data, the average AOFAS score improved from 44 preoperatively to 79 at the time of the three-year follow-up, the average total musculoskeletal functional assessment injury and arthritis survey scores improved from 38 to 18, and visual analog pain scores improved from 8 to 2. Ankle range of motion improved on average by 5°, and 95% of the patients reported satisfaction with the procedure. However, the overall complication rate was 24%, and more than half of the complications were considered to be serious and required a second major operation. The most common complication was nonunion of the syndesmosis, but some patients required revision or fusion. In the group of forty-six patients who had incomplete data at three years, six additional complications occurred, including the necessity for amputation. These data suggest that, in properly selected patients, the Agility total ankle replacement can relieve pain and improve function at the time of the three-year follow-up, but the complication rate is high. The results of 200 total ankle arthroplasties with use of the Scandinavian total ankle replacement (STAR; Waldemar Link, Hamburg, Germany) were reported by Prem and Wood24. The average age of the patients was sixty-one years, 119 subjects had rheumatoid arthritis, and eighty-one subjects had osteoarthritis. The rate of implant survival was 93% at five years and 79% at ten years. Twenty-four ankles required revision because of failure resulting from infection, fracture of the medial malleolus, polyethylene fracture, aseptic loosening, or progressive malalignment. The average AOFAS pain score improved from 0 to 35, the average function score improved from 31 to 40, and survivorship was comparable with that reported for the Agility total ankle prosthesis. Brodsky et al. prospectively analyzed the gait pattern of forty-nine patients before and after total ankle arthroplasty with use of the STAR25. Three-dimensional gait analyses were performed preoperatively and then annually for up to six years. Significant increases were found in velocity, ankle range of motion during gait, and peak sagittal ankle joint power at push-off. The study demonstrated objective improvement in gait function when compared with the preoperative condition and demonstrated superior results in comparison with those in previous studies of gait analysis following ankle arthrodesis. Schneiderbauer et al. reported a 3.1% infection rate after primary ankle replacement in a study of 386 ankles26. Infection was diagnosed on culture of tissue specimens that had been collected during revision surgery. Four of the twelve infected ankles had a history of infection or open fracture. The most common infecting organism was Staphylococcus aureus, followed by coagulase-negative staphylococci and anaerobes. The median time from primary implantation to infection was nine months. Treatment consisted of surgical débridement and either liner or component exchange in addition to six weeks of antibiotics. Three patients required flap coverage. The reported 3.1% infection rate was higher than rates reported in the literature for primary knee and hip arthroplasty.
Arthroscopic ankle arthrodesis is typically recommended for ankles with minor deformities, with reported fusion rates of >90%. The results of seventy-eight arthroscopic ankle arthrodeses for both minor (<15°) and major (>15°) varus-valgus deformity were retrospectively reviewed by Gougoulias et al.27. No difference in fusion rates was noted between ankles with (97%) and without (98%) major deformity. All fused ankles were considered to have restoration of normal alignment radiographically. Patients with poor bone quality or posttraumatic deformity may require more rigid fixation to achieve union at the site of an ankle arthrodesis. Tarkin et al. performed biomechanical testing on cadaver ankles with use of a low-profile anterior plate to supplement screw fixation at the site of an arthrodesis28. Less motion occurred at the tibiotalar interface in all tested planes of motion after plate supplementation. Percutaneous posterolateral screw placement is commonly used to augment fixation at the site of an ankle arthrodesis. Keeling and Schon assessed the risk to the sural and tibial nerves in association with percutaneous placement of the posterolateral screw in a study of cadaver ankles29. After the guide-pin had been placed, dissection was carried out to determine its proximity to local neurovascular structures. The guide-pin did not contact either the sural or the tibial nerve in any specimen, but the average distance to these structures was 0.9 and 6.5 mm, respectively. Adjacent tarsal joint degeneration is a long-term sequela of the altered kinematics and load transfer that occurs after tibiotalar arthrodesis. Jung et al. used pressure-sensitive sensors in a cadaver ankle dorsiflexion loading model to measure adjacent-joint contact and peak pressures before and after screw fixation of the tibiotalar joint30. Their results suggested a significant increase in pressure in the talonavicular and calcaneocuboid joints in association with ankle dorsiflexion, corresponding to the late stance phase of gait. Limiting the number of joints that are included in an arthrodesis may preserve more normal foot mechanics and theoretically may decrease the risk of future adjacent-joint degeneration. Sammarco et al. applied this concept by performing a modified double arthrodesis in lieu of a triple arthrodesis31. The calcaneocuboid was excluded from sixteen procedures that were undertaken to correct symptomatic flatfoot, cavovarus deformity, or hindfoot arthritis, in which the calcaneocuboid joint was not involved in the primary disease. AOFAS scores and all radiographic parameters improved significantly. However, after an average duration of follow-up of forty-seven months, five feet demonstrated clinically asymptomatic but radiographically evident progression of degeneration at the calcaneocuboid joint. Glanzmann and Sanhueza-Hernandez performed a prospective study to evaluate the clinical and radiographic results of arthroscopic subtalar fusion with autologous bone-grafting32. The authors used the anterolateral and posterolateral portals for débridement of the posterior, middle, and anterior facets and the interosseous ligament as well as for the insertion of bone graft into the sinus tarsi. The average AOFAS score improved from 53 points preoperatively to 84 of 94 points (accounting for 6 points that were lost because of subtalar fusion) postoperatively. The radiographic fusion rate was 100%, and 96% of the procedures had a good to excellent clinical result. Amendola et al. reported on their early experience with posterior arthroscopic subtalar arthrodesis33. With the patient in a prone position, three posterior portals were established, including in posteromedial and posterolateral sites. Débridement was performed posterior to the interosseous ligament and to the extent of anterior visualization from the posterior portals. Two cannulated 6.5-mm cancellous screws were then placed across the posterior facet for fixation. No complications were reported. The average AOFAS score improved from 36 points preoperatively to 86 points (maximum, 94 points) postoperatively, and ten of eleven joints demonstrated radiographic and clinical union by ten weeks. The results suggested that posterior arthroscopic subtalar arthrodesis is a safe procedure that offers reliable fusion rates and high patient satisfaction.
Total contact casting remains the gold standard treatment with which to offload Wagner grade-1 and 2 diabetic foot ulcers. Frigg et al. reported ulcer recurrence rates of 57% after primary total contact casting treatment at an average of 4.6 months34. The authors found that most recurrences were caused by underlying foot deformities that, when operatively corrected, resulted in a significantly longer ulcer-free interval or prevented ulcer recurrence entirely. Total contact casting was effective for healing primary ulcer recurrences, but new recurrences developed in 50% of those patients. On the basis of their experience, the authors recommended aggressive surgical correction of all existing underlying deformities after the primary ulcers heal. In a study investigating the optimal placement of metatarsal pads on total contact shoe inserts for reducing peak plantar pressure under the middle metatarsal heads, Hastings et al. recorded peak plantar pressure and used computed tomography scans to verify the pads' position35. Metatarsal pads were placed proximal and distal relative to the center of the second metatarsal head. The greatest reduction in peak plantar pressure (57%) was registered when the distal aspect of the pad was 10.6 mm proximal to the center of the second metatarsal head, whereas consistent reduction in pressure occurred if the pad was placed between 6.1 and 10.6 mm proximal to the center of the second metatarsal head. However, the authors found an inherent inaccuracy in the placement of the pads; for this reason, they recommended that the patient's foot be checked shortly after the orthosis is worn to check for redness, callus, and signs of skin breakdown. Ankle stiffness and limited dorsiflexion range of motion are factors that are thought to contribute to the development of plantar ulcers in patients with diabetes. Rao et al. confirmed this theory with use of the Iowa Ankle Range of Motion Device, which has established validity and interobserver reliability36. In a study that compared twenty-five diabetic patients with sixty-four nondiabetic individuals, the authors demonstrated significantly lower peak dorsiflexion range of motion and higher passive ankle stiffness in the diabetic group. Additionally, they found an association between poor glycemic control, as measured on the basis of HbA1c levels, and the duration of diabetes mellitus with ankle stiffness. Diagnosing osteomyelitis in the feet of diabetic patients presents a major challenge. Most imaging techniques are highly sensitive for detecting inflammation but lack the specificity to differentiate noninfective inflammation from infection. It is thus difficult, if not impossible, to rule out associated neuroarthropathy, healing fracture, diabetic osteopathy, or soft-tissue inflammation from the differential diagnosis. In a prospective study, Dutta et al. combined a technique with 100% sensitivity (99mTc methylene diphosphonate triple-phase bone scanning) with one of high specificity (99mTc-ciprofloxacin scintigraphy) to diagnose osteomyelitis in diabetic feet37. A total of nineteen patients with Wagner class-III diabetic foot ulcers and six control patients with only superficial ulcers received both scans. Osteomyelitis was confirmed by means of bone biopsy and histopathological studies or cultures. Combining these scans was effective for the diagnosis of diabetic foot osteomyelitis, demonstrating a sensitivity of 100% and a specificity of 85.7%. Nonetheless, bone biopsy and histopathology remains an essential diagnostic tool because the combination of these scans was unable to differentiate osteomyelitis from soft-tissue infection.
In the first phase of a prospective randomized study on the treatment of plantar fasciitis, plantar fascia-specific stretching demonstrated superior results to Achilles tendon-stretching at eight weeks of follow-up. Digiovanni et al. reported these two-year outcomes after patients who were initially managed with the Achilles tendon-stretching protocol were switched to the more effective plantar fascia-specific stretching program38. Patients were taught to stretch the plantar fascia by dorsiflexing the metatarsophalangeal joints while palpating the area of maximal tenderness a total of ten times per session, with at least three sessions per day. At the time of the two-year follow-up, all patients showed significant improvement from baseline in terms of the experience of pain with the first steps in the morning and in terms of the severity of heel pain at its worst. Additionally, once patients were switched at eight weeks from Achilles tendon-stretching to plantar fascia-specific stretching, they improved at a faster rate and showed no difference at two years in comparison with those who had been initially started on plantar fascia-specific stretching. Overall, the long-term data indicated that 90% of patients will be satisfied and will experience a reduction in heel pain, that there is a 75% chance of returning to full activity, that no further treatment will be needed, and that the majority of patients will achieve their best results by six months. Plantar fasciitis is commonly treated with an orthotic device, yet few well-designed studies with sufficient power to demonstrate significance have evaluated the short and long-term efficacy of orthotic devices. Landorf et al. conducted a participant-blinded, randomized trial comparing the benefit of prefabricated and customized orthotic devices with that of a sham treatment39. Patients with chronic plantar fasciitis were randomly selected to use one of the three devices while abstaining from other treatments (anti-inflammatory medications or corticosteroid injections). Both the prefabricated and customized orthoses produced short-term benefits. Significant improvement in function was found at three months, while only a trend was noted in terms of pain reduction. These benefits compared with sham treatment were lost by one year. The results support orthotic treatment for short-term relief of plantar fasciitis. Additionally, the customized orthoses had no advantage over lower-cost prefabricated orthotic devices. While extracorporeal shock wave therapy has been approved by the Food and Drug Administration for the treatment of plantar fasciitis, the question of its effectiveness remains. Dorotka et al. evaluated whether the location of the shock waves influences outcomes40. Patients received fluoroscopically guided shock wave therapy either at the location of a heel spur or at the patient-directed area of maximum tenderness. While all patients improved from baseline, the results indicated that the location of therapy had no effect on outcome. Because of the increased exposure to radiation and the longer time necessary for fluoroscopic localization, the authors recommend focusing extracorporeal shock wave therapy at the area of maximum tenderness. Bazaz and Ferkel reported the results of a two-portal endoscopic plantar fascia release41. This technique provided significant improvement in terms of symptoms: the average AOFAS and Maryland Foot scores improved by 22 and 21 points, respectively. Factors associated with inferior outcomes included more severe symptoms, a duration of symptoms of longer than two years prior to endoscopic plantar fascia release, Workers' Compensation, and male gender.
To evaluate the suggestion that degenerative Achilles tendinopathy may be associated with systemic diseases such as obesity, diabetes, and hypertension, as well as with exposure to steroids, Holmes and Lin performed an epidemiologic study of patients in whom Achilles tendinopathy had been diagnosed clinically and confirmed with magnetic resonance imaging42. Overall, 98% of the patients had hypertension, diabetes, obesity, and steroid or estrogen exposure, which demonstrated an increased aggregate association with symptomatic Achilles tendinopathy. A significant correlation was found between Achilles tendinopathy and hormone replacement therapy, oral contraceptive use, obesity, hypertension in women, and diabetes mellitus in men younger than forty-four years of age. These results suggested a possible end-organ effect causing a decrease in local microvascularity at the Achilles tendon. Wagner et al. reported on seventy-five patients (eighty-one heels) who were managed for insertional Achilles tendinosis43. The Achilles tendon was operatively débrided and the insertion completely detached from the calcaneus if >50% of the tendon was found to be diseased. The tendon was reattached with three four-prong suture anchors with number-2 polyester sutures with use of a modified Krakow technique. A V-Y lengthening of the Achilles tendon was performed through the aponeurosis proximal to the musculotendinous junction to provide length lost from excision of diseased tendon. Detaching the tendon did not significantly affect short or long-term satisfaction rates or any parameter evaluated in the study, and the authors proposed routine detachment of the Achilles tendon with proximal V-Y lengthening in cases of insertional Achilles tendinosis. Two randomized controlled trials were performed by Costa et al. to evaluate the potential benefits of immediate weight-bearing mobilization after surgical repair and nonoperative treatment of the ruptured Achilles tendon44. Patients in each group were managed with non-weight-bearing immobilization in an equinus short leg cast or immobilization with immediate weight-bearing in an orthosis with heel rises. In the operative group, there was a more rapid return to normal walking and stair-climbing with immediate weight-bearing immobilization in an orthosis than with immobilization in a cast. In the nonoperative group, no difference was found between the two treatment groups. The results supported immediate weight-bearing immobilization in an orthosis after surgical repair of the ruptured Achilles tendon. Traditionally, postoperative treatment of the surgically repaired Achilles tendon rupture includes immobilization of the ankle in plantar flexion. This is thought to decrease the tensile stress across the repair site, which relies on the strength of the suture material until healing is adequate. Serial reduction of the equinus position is performed at the time of follow-up until a neutrally positioned foot is achieved. Labib et al. measured the static tension in the Achilles tendon at varying degrees of plantar flexion before and after surgical repair45. The tendon was repaired with number-2 braided polyester sutures with use of the Krakow locking technique reinforced with a running baseball stitch of 4.0 monofilament polypropylene. Static tension in the repaired Achilles tendon group was equal to that of the intact tendon at all positions of plantar flexion. Additionally, the tension in the repaired tendon at the neutral position was only a small percentage of the tension observed at failure of the repair. This study suggested that positioning the ankle in plantar flexion after secure surgical repair of the ruptured Achilles tendon may not be necessary. Several small intestinal submucosa extracellular matrix scaffold products are currently available on the market for the repair of musculotendinous tissues and other applications. Gilbert et al. evaluated the rate of degradation, the fate of the degradation products, and the temporal histologic changes exhibited by these scaffolds when used as an interpositional graft in the canine Achilles tendon46. The results showed that the graft degrades rapidly, losing approximately 60% of its mass by one month, and resorbs completely by three months. Host cells infiltrate the graft, peaking at fourteen days as new host tissue begins ingrowth. By one month, the graft-native tissue interface was difficult to discern and the remodeled extracellular matrix showed signs of organization. By three months, the scaffold was replaced by organized host tissue that appeared histologically similar to that of native Achilles tendon. Degradation products were excreted primarily in urine and were not found in parenchymal organs. The application of these biologic scaffolds holds promise for the repair of Achilles tendons.
The relationship between pes planus and injuries to the lower extremity is unclear. Levy et al. performed a prospective study over forty-six months to evaluate the incidence of lower extremity injuries in association with pes planus in a physically active population47. With use of a standardized objective measure (Harris mat footprints) to define pes planus, the researchers identified significant relationships between the degree of pes planus (large midfoot ratio), larger foot size (total foot area), and the total number of injuries sustained. Left foot pes planus was found to be correlated with left and right midfoot injuries and left knee injuries. Women were found to have significantly smaller feet and lesser degrees of pes planus but sustained more injuries than men did. These results suggest that having larger feet and pes planus may predispose patients to lower extremity injuri |
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Introduction
Ankle Fractures