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The Journal of Bone and Joint Surgery (American). 2009;91:1023-1031. doi:10.2106/JBJS.I.00078 © 2009 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 2007 and July 2008. 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 March 8, 2008, in San Francisco, California, and the summer meeting of the American Orthopaedic Foot and Ankle Society (AOFAS), held on June 25 through 28, 2008, in Denver, Colorado.
Urgent reduction of ankle fracture-dislocations is imperative to restore vascularity to the foot, to reduce pressure on the skin, to minimize articular injury, and to relieve patient discomfort. In a prospective randomized clinical trial, White et al. compared two methods of analgesia that are commonly used for the reduction of ankle fracture-dislocations1. Twenty-one patients were randomized to receive 12 mL of 1% lidocaine, delivered as a sterile intra-articular injection, and twenty-one patients were randomized to receive intravenous conscious sedation. The medications administered for conscious sedation were a combination of a benzodiazepine and narcotic, with the specific type and amount of drug being left to the discretion of the emergency room physician administering the sedation. Visual analog pain scales were completed by the patient to estimate pain before, during, and after the reduction procedure, and the treating residents rated the difficulty of obtaining the reduction. Both the block and the sedation reduced pain to a similar degree, and the average difficulty-of-reduction ratings were equivalent. While no complications occurred as a result of either mode of analgesia, the block group required a higher number of repeat reductions, although the difference failed to reach significance. Because of the small sample size of that study, additional investigation may be required to determine the effect of the type of analgesia used and the quality of reduction achieved. The application of a spanning external fixator is a reliable form of temporary stabilization for two-staged treatment of pilon and ankle fractures. Forefoot pin placement, in particular, can augment the fixation that is needed to maintain fracture alignment as well as to prevent the formation of an equinus contracture. Barrett et al. investigated the threat to the deep plantar branch of the dorsalis pedis artery during transmetatarsal pin placement2. With use of fluoroscopy, a 4.0-mm Schanz pin was directed medial to lateral across the first intermetatarsal space in ten cadaveric feet, in a manner identical to the typical intraoperative technique of external fixation as described in the literature. The specimens were then dissected to evaluate damage to arterial structures. In five of the ten specimens the fixator pin lacerated the deep plantar artery, in another four specimens the pin contacted but did not damage the artery, and in one specimen the pin passed only 4 mm away from the artery. On the basis of the results of that study, transmetatarsal pinning from medial to lateral should be avoided in favor of locations with lower risk to adjacent anatomic structures.
Operative fixation of closed displaced calcaneal fractures is a technically challenging procedure that may be complicated by postoperative deep infection and subtalar arthritis. Poeze et al. performed a systematic review of the literature investigating the relationship between the volume of closed calcaneal fractures that are treated operatively at an institution and the rates of deep infection and subtalar arthritis3. Their meta-analysis included twenty-one studies representing 1656 calcaneal fractures from both retrospective and prospective studies. Statistical analysis showed a significant inverse relationship between institutional fracture load and the rates of infection requiring operative intervention and subtalar arthritis resulting in subsequent subtalar arthrodesis. The findings of that study suggest that a substantial learning curve exists in the operative treatment of calcaneal fractures, which affects clinical outcomes. The authors concluded that an institutional fracture load of less than one fracture per month per center would jeopardize the outcome of operatively treated displaced intra-articular calcaneal fractures. The fixation used for the repair of avulsion fractures of the posterior calcaneal tuberosity must neutralize the Achilles tendon force to prevent late displacement. Khazen et al. used a cadaver model to simulate posterior calcaneal avulsion fractures in order to compare the fixation strength of two 4.0-mm lag screws alone and in conjunction with two suture anchors4. Biomechanical testing demonstrated a significantly greater load to failure with the addition of the two suture anchors to the fixation construct. While that study supports the augmentation of lag screw fixation with suture anchors, the authors cautioned that the more extensive exposure needed for suture anchor placement may increase the risk of iatrogenic Achilles tendon rupture and skin breakdown.
Kaar et al. used a cadaver model to define which disrupted ligaments produce transverse and longitudinal Lisfranc joint injury patterns5. The first cuneiform-second metatarsal (Lisfranc) ligament was sectioned in each of ten cadavera. Additional sectioning of the plantar ligament between the first cuneiform and the second and third metatarsals produced the transverse instability pattern. The longitudinal instability pattern required disruption of the Lisfranc ligament and the interosseous ligament between the first and second cuneiforms. The authors then compared the effectiveness of weight-bearing, abduction, and adduction stress radiographs in the diagnosis of each injury pattern. Weight-bearing radiographs demonstrated enough diastasis to diagnose instability in only one of five feet for both instability patterns. Abduction stress radiographs were most sensitive for the transverse Lisfranc instability pattern in that they correctly demonstrated diastasis of >2 mm between the first cuneiform-second metatarsal and the second cuneiform-second metatarsal joints in five of five specimens. Adduction stress radiographs were most accurate for detecting the longitudinal Lisfranc instability pattern in that they correctly demonstrated diastasis between the first and second cuneiforms in four of five specimens. The results of that study suggest that injury-specific stress radiographs should be made with fluoroscopy to more accurately determine the presence and the pattern of instability.
The role of total ankle arthroplasty as a viable surgical alternative to arthrodesis continues to be a controversial topic in the treatment of ankle arthritis. In their observational study, SooHoo et al. compared patient demographic characteristics and population-based rates of complications following ankle replacement and fusion in California from 1995 through 20046. Patients managed with an arthroplasty had a significantly higher rate of major revision at ninety days and five years postoperatively and had a significantly higher rate of readmission for the treatment of infection related to an implanted device at ninety days. The subtalar arthrodesis rate was 2.8% in the ankle fusion group and 0.7% in the arthroplasty group; this difference reached significance. Interestingly, the patients managed with arthrodesis were significantly more likely to have complicated diabetes and to be black or of Hispanic ethnicity. Patients undergoing ankle arthroplasty had a significantly higher median income and were less likely to have safety-net health insurance as represented by Medicaid. Piriou et al. used gait analysis to compare the results of ankle arthrodesis with those of arthroplasty with use of the Salto Talaris Anatomic Ankle (Tornier, Saint-Ismier, France) at six months and one year7. Although no difference was found in stride cadence between the groups, the analysis demonstrated a faster gait speed, a longer step length, and a greater relative asymmetry of step length for the arthrodesis group. The arthroplasty group had greater ankle motion, a more symmetric gait pattern, and a ground reaction force that more closely resembled that of the control group. Although that study was one of the first to directly compare arthrodesis and arthroplasty of the ankle with use of gait analysis, additional studies are necessary to fully understand the effects of these procedures on gait. Salvage of the failed total ankle arthroplasty presents a tremendous surgical challenge because of the extensive bone loss that is commonly encountered in addition to a typically poor soft-tissue envelope. Culpan et al. evaluated the results for sixteen patients who had a failed total ankle arthroplasty that was subsequently revised to arthrodesis8. Their fusion technique employed harvesting of a tricortical iliac crest autograft and impaction of the graft into the joint space void following removal of the implants and débridement. Fixation was achieved with 4.5-mm cortical screws, with the addition of a bridging plate in some cases to augment fixation. Revision arthrodesis was successful by three months in the cases of all patients except one, who had rheumatoid arthritis and required intramedullary nail placement before fusion was achieved. The mean American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score improved from 31 preoperatively to 70 at an average of more than three years of follow-up. Mobile-bearing (three-component) total ankle arthroplasty implants have yet to be approved by the United States Food and Drug Administration (FDA) for general use in the United States. However, successful results associated with the three-component Scandinavian Total Ankle Replacement (STAR; Waldemar Link, Hamburg, Germany) have been well described in the European literature. With an FDA investigational device exemption for use of the STAR prosthesis in the United States, DeOrio et al. reported on the intermediate-term clinical and radiographic results for ninety-one uncemented implants that were followed for as long as ten years9. The mean AOFAS score improved from 32.4 preoperatively to 87.3 postoperatively, whereas the mean visual analog scale pain score decreased from 74.45 to 10.96. Ankle dorsiflexion and plantar flexion improved by 4° and 8°, respectively. Thirteen percent of the patients required reoperation for various reasons, including aseptic loosening (one patient), component malpositioning (two), talar component oversizing (one), removal of implants for infection (one), conversion to arthrodesis (one), and revision to an alternative total ankle arthroplasty (one). The investigators concluded that the STAR prosthesis demonstrated good clinical and radiographic results at the time of intermediate-term follow-up.
In a retrospective review, Easley et al. evaluated the results of revision tibiotalar arthrodesis, with an emphasis on the use of ring external fixation10. The average AOFAS hindfoot score improved from 31 points preoperatively to 65.8 points at a mean of fifty months of follow-up, with an overall successful union rate of 88.9%. Fusion was achieved in nineteen (86%) of twenty-two patients who underwent revision tibiotalar arthrodesis with the ring external fixator, in three of four patients who underwent repeat revision tibiotalar arthrodesis with the ring external fixator, in eight (73%) of eleven patients who underwent revision tibiotalar arthrodesis with internal fixation with use of 7.3-mm cannulated screws, and in nine (75%) of twelve patients who underwent tibiotalocalcaneal fixation with use of a retrograde nail or the lateral blade-plate technique. In spite of the encouraging fusion rates demonstrated in the ring external fixator subgroup, eleven (58%) of the nineteen major complications and twenty-seven (82%) of the thirty-three minor complications occurred following its use, which is consistent with rates reported in previous studies. The authors concluded that, regardless of the treatment method employed, revision ankle arthrodesis is a challenging but viable alternative to amputation. Ring external fixators can be confidently used in the majority of revision cases; however, a consensus on the ideal indications for their use has yet to be defined. Ring external fixators are particularly valuable in cases of a previous infection at the site of a nonunion, in which the placement of implants across the infected area is contraindicated, as well as in the case of poor bone quality, in which internal fixation would potentially fail. Newer generations of retrograde intramedullary tibiotalocalcaneal arthrodesis nails have added angle-stable threaded locking holes and options to allow compression. In the biomechanical study by Mückley et al., the new second-generation angle-stable and compressed angle-stable nails were compared with the first-generation statically locked nails11. Synthetic and cadaveric bone models were used to evaluate the two different types of nails and a total of three different locking modes: (1) an angle-stable locking nail in compression mode (T2 Ankle Arthrodesis Nail [AAN]; Stryker Osteosynthesis, Schönkirchen, Germany), (2) an angle-stable locking nail not in compression mode (T2 Ankle Arthrodesis Nail [AAN]; Stryker Osteosynthesis), and (3) a static locking nail (Biomet Ankle Arthrodesis Nail; Biomet, Berlin, Germany). The newer-generation nails with locking and compression features were found to be significantly superior in both bone models for all tested parameters, both initially and after cyclic loading. That study demonstrated the superior biomechanical stability of the newer intramedullary nails with locking options; however, improved outcomes have not been tested in clinical studies. Two related biomechanical cadaveric studies were performed to define the role of locking plate technology in tibiotalocalcaneal arthrodesis. In the study by Chodos et al., the use of a stainless steel 4.5-mm 90° six-hole cannulated LC-angled blade plate with a 40-mm blade (Synthes, Paoli, Pennsylvania) was compared with the use of a stainless steel five-hole 3.5-mm LCP proximal humeral locking plate (Synthes) for tibiotalocalcaneal arthrodesis12. The locking plate group had higher initial stiffness, higher dorsiflexion and torsional load to failure, and lower construct deformation than the blade plate group did. In the study by O'Neill et al., a ten-hole locking plate (Synthes) with a 6.5-mm augmentation screw placed from the calcaneus into the anteromedial aspect of the distal part of the tibia was compared with a 12 x 150-mm intramedullary nail (Biomet, Warsaw, Indiana), also with a 6.5-mm augmentation screw13. No significant biomechanical differences were found, except for higher final rigidity in association with the locking plate construct. Those studies suggest that locking plate technology has biomechanical properties that are equivalent to or greater than those of methods currently used to achieve tibiotalocalcaneal fusion. Ahmad et al. were the first to report on the use of locking plate technology for fixation in patients undergoing tibiotalocalcaneal arthrodesis14. Proximal Humerus Internal Locking System (PHILOS) plates (Synthes) were used for eighteen tibiotalocalcaneal arthrodeses in seventeen patients who were followed for a mean of 20.6 months. Successful tibiotalocalcaneal fusion occurred in seventeen (94.4%) of the eighteen ankles, and the average AOFAS score increased from 14.6 of 100 preoperatively to 76.7 of 86 at the time of the latest follow-up. The biomechanical advantages of locking plate technology and reports of encouraging early outcomes make locking plates an appealing option for tibiotalocalcaneal fusion.
Conventional treatment of Eichenholtz stage-I Charcot foot arthropathy involves the use of a non-weight-bearing total contact cast. The rationale for enforcing a strict non-weight-bearing status is to minimize mechanical forces on the foot while inflammation and swelling subside, thereby allowing the foot to stabilize in a position of minimum deformity. In a nonrandomized prospective study, de Souza challenged this accepted treatment15. Total contact casts were used to treat thirty-four feet in twenty-seven patients with Eichenholtz stage-I or early stage-II Charcot arthropathy, and patients were instructed to bear weight as tolerated with use of a rocker-bottom cast boot. After an average duration of follow-up of 5.5 years, thirty-three of the thirty-four feet demonstrated no additional anatomic changes or osteoligamentous disruption that had not already been present before the initiation of treatment. Additionally, no patient had development of an ulcer while wearing the total contact cast, despite the lack of weight-bearing restrictions. The author concluded that weight-bearing in a total contact cast is a safe method of treatment with minimum risk for the progression of deformity in patients with Eichenholtz stage-I Charcot arthropathy. Pinzur reported on his experience with the treatment of advanced nonplantigrade Charcot midfoot deformity in a population of patients who were at high risk for surgery-related complications16. Patients with Eichenholtz stage-II or III deformity and multiple comorbidities were prospectively selected for treatment with a neutral ring fixator to minimize the risk of deep infection. A total of twenty-six patients received a neutral ring fixator following the removal of a triplanar wedge of bone at the apex of the deformity to correct alignment. Four of these patients had development of new ulcers and needed additional surgery in the form of an exostectomy. After a minimum duration of follow-up of one year, twenty-four of twenty-six patients achieved a "favorable outcome," which was defined as remaining free of ulceration and infection and being able to walk in the community with use of commercially available depth-inlay shoes and a custom accommodative foot orthosis. No infections developed at the osteotomy site, but several complications occurred. A transtibial amputation was required for an unresolved, pre-existing osteomyelitis, and two patients had development of tibial stress fractures after removal of the external fixator. These results indicate that correction can be achieved and maintained in high-risk patients with a severe nonplantigrade Charcot midfoot deformity with use of a neutral external ring fixator.
Nonoperative treatment of chronic noninsertional Achilles tendinopathy is now being extensively studied. As a follow-up to their 2004 randomized, double-blind, placebo-controlled clinical trial, Paoloni and Murrell sought to determine if the significantly decreased Achilles tendon pain and tenderness that they observed in association with topical glyceryl trinitrate treatment at twenty-four weeks would endure at three years17. The comparison group that initially received a placebo patch instead of the glyceryl trinitrate patch was not controlled during the follow-up period. As a result, ten (36%) of the twenty-eight patients had used other treatment modalities, including topical glyceryl trinitrate, extracorporeal shock wave therapy, a walking boot, topical herbal medication, acupuncture, and Achilles tendon débridement. Although the intervening treatments in the placebo group make a comparison with placebo at three years difficult, the results for the patients in the original glyceryl trinitrate patch group remain encouraging. The treatment benefits from the original glyceryl trinitrate patch group continued at three years as 88% of the patients in that group reported being completely asymptomatic, as compared with 67% of those in the comparison group. The mechanism for the beneficial effect of topical glyceryl trinitrate remains unknown. The results of shock wave therapy on insertional and noninsertional Achilles tendinopathy have been promising in pilot studies, and this modality has been found to be effective for the treatment of lateral elbow tendinopathy and plantar fasciitis. The low-energy shock waves are thought to stimulate soft-tissue healing, to enhance angiogenesis, and to inhibit pain receptors. Rompe et al. performed a randomized controlled trial in which repetitive low-energy shock wave therapy was compared with eccentric training exercises for the treatment of chronic insertional Achilles tendinopathy18. At the four-month follow-up, both groups showed significantly improved Victorian Institute of Sport Assessment-Achilles (VISA-A) scores; however, only 28% of the patients in the eccentric training group (as compared with 64% of those in the shock wave therapy group) reported being completely recovered or much improved. Outcomes related to pain, the pain threshold, and palpable tenderness were improved in both treatment groups, although the shock wave therapy group had significantly more favorable results. That study lends support to the treatment of chronic insertional Achilles tendinopathy with low-energy extracorporeal shock wave therapy.
The chevron osteotomy is a commonly performed V-shaped distal metatarsal osteotomy that is used for the correction of mild to moderate hallux valgus. The osteotomy cuts place the metatarsal head fragment at risk for osteonecrosis, the prevalence of which has been reported to range from 0% to 20%. Malal et al. performed a cadaver study to review the vascularity of the first metatarsal head and to establish the relationship of the chevron osteotomy to the vascular network supplying the first metatarsal capital fragment19. Specimens were injected with an India ink-latex mixture, and then a standard medial bunionectomy and chevron osteotomy were performed. Dissection revealed that the first metatarsal head was supplied by branches from the first dorsal metatarsal, first plantar metatarsal, and superficial medial plantar arteries, with the first dorsal metatarsal artery acting as the dominant vessel in the majority of the specimens. All three vessels anastomose along the plantar lateral aspect of the metatarsal neck, just proximal to the capsular attachment, and several branches from this plexus then supply the metatarsal head. The finding of a plantar lateral vascular plexus supplying the metatarsal head differs from previous descriptions of the vascular supply penetrating the dorsal and lateral aspects of the joint capsule. The plantar limb of the chevron osteotomy was found to emerge through this plantar lateral vascular plexus in all of the specimens. On the basis of their findings, the authors recommended completing a chevron osteotomy with a long plantar limb exiting proximal to the capsule in order to decrease the risk of injury to the vessels and therefore lessen the rate of osteonecrosis. Okuda et al. performed a retrospective review analyzing the relationship between the shape of the first metatarsal and hallux valgus deformity20. Dorsoplantar weight-bearing radiographs of sixty normal feet (the control group) and sixty feet with hallux valgus were reviewed. The shape of the lateral edge of the first metatarsal head was classified radiographically as either round (type R), angular (type A), or intermediate (type I). Operative correction in the hallux valgus group consisted of a distal soft-tissue release and medial capsulorrhaphy, medial bunionectomy, and proximal crescentic metatarsal osteotomy. Radiographic classification of the feet in the hallux valgus group was performed preoperatively, at the time of early follow-up (mean, 3.4 months), and at the time of the most recent follow-up (mean, forty-eight months). A significantly greater prevalence of the type-R-shaped first metatarsal head was found in the hallux valgus group preoperatively. At the time of the early follow-up, fewer patients demonstrated the type-R shape. In addition, feet with a round-type-appearing metatarsal head at the time of the early follow-up had a greater risk of having a recurrence of the hallux valgus deformity at the time of the most recent follow-up. According to the authors' supposition, the round appearance of the lateral edge of the metatarsal on radiographs is likely due to the pronation deformity of the first metatarsal that occurs in patients with hallux valgus, which rotates the convex articular surface of the metatarsal head into view on a dorsoplantar radiograph. The postoperative disappearance of the type-R metatarsal head was likely due to operative supination of the distal fragment. Supination of the capital fragment restores a more anatomic rotation and allows the more angular lateral edge to come into view on a dorsoplantar radiograph while the convex articular surface of the metatarsal swings out of view. That study underscores the three-dimensional deformity of hallux valgus and introduces an intraoperative method to identify feet at higher risk of recurrence through recognition of a type-R metatarsal head on an intraoperative radiograph. The Ludloff osteotomy is an oblique proximal first metatarsal osteotomy that is oriented from dorsal-proximal to distal-plantar and is indicated for the surgical correction of moderate-to-severe hallux valgus deformity. The Ludloff osteotomy may allow for more reliable control of the first metatarsal in the sagittal plane and therefore may decrease the risk of transfer metatarsalgia. Trnka et al. reported the intermediate-term results for 111 feet that underwent hallux valgus correction with use of a modified Ludloff osteotomy21. The mean AOFAS score significantly improved from 53 points preoperatively to 88 points after an average duration of follow-up of thirty-four months. The mean hallux valgus angle decreased significantly from 35° preoperatively to 9° at the time of the latest follow-up, and the mean intermetatarsal angle also decreased significantly from 17° to 8°. No dorsiflexion malunion was noted, and the first metatarsal shortened by a mean of only 2.2 mm. Those findings suggest that the modified Ludloff osteotomy combined with a distal soft-tissue procedure can produce reliable outcomes with a low complication rate, results that are comparable to those associated with more commonly reported osteotomies for the correction of moderate-to- severe hallux valgus. Coughlin and Jones performed a prospectively designed study to investigate the results of proximal crescentic osteotomy and distal soft-tissue reconstruction for the treatment of hallux valgus deformities22. Outcomes were reported for 122 feet after two years of follow-up on the basis of preoperative and postoperative pain and AOFAS scores in addition to objective measurements including ankle range of motion, Harris mat imprints, first ray mobility, and radiographic angles. The mean visual analog scale pain score decreased significantly from 6.5 points preoperatively to 1.1 points following surgery, the mean AOFAS score improved significantly from 57 to 91 points, and 93% of the patients reported a satisfactory result. In addition, no correlation between limited preoperative or postoperative ankle dorsiflexion and the magnitude of hallux valgus deformity was found. Some interesting data regarding hallux valgus and the first metatarsocuneiform joint were also reported. In particular, radiographic evidence of plantar gapping of the first metatarsocuneiform joint did not significantly affect the mobility of the first ray as measured with a validated and calibrated Klaue device. The plantar gapping resolved postoperatively in one-third of the cases, and the preoperative mobility of the first ray was significantly decreased following surgical hallux valgus correction. However, the severity of the hallux valgus deformity was significantly greater for patients with radiographic evidence of plantar gapping of the first metatarsocuneiform joint. No evidence of radiographic progression of degenerative arthritis of any first metatarsocuneiform joint was demonstrated, despite having those joints penetrated by 118 Kirschner wires and fifty-five screws. Overall, the authors concluded that the proximal crescentic osteotomy combined with a distal soft-tissue reconstruction has good results and can significantly diminish mobility of the first ray, possibly avoiding the need for a Lapidus procedure (fusion of the metatarsocuneiform joint) in some cases. A second study focusing on the mobility changes of the first ray following hallux valgus correction was performed by Kim et al.23. The modified Klaue device was used to measure dorsiflexion of the first ray in eighty-two feet, both preoperatively and one year after a proximal metatarsal chevron osteotomy and distal soft-tissue procedure. Satisfactory results were reflected in the significant improvement in the mean AOFAS score from 66.2 points preoperatively to 89.1 points postoperatively. The average dorsiflexion mobility of the first ray decreased from 6.8° preoperatively to 3.2° at one year postoperatively. A group of eighteen patients was identified preoperatively as having hypermobility of the first ray (defined as >9 mm of dorsiflexion mobility) in order to evaluate the results of a subset of patients who may require a Lapidus procedure. The mean reduction ratio in dorsiflexion mobility was 60% in the hypermobile group, compared with 54% in the total patient population. Those results suggest that first metatarsocuneiform joint motion is reduced following a proximal metatarsal chevron osteotomy and distal soft-tissue procedure. Evidence is beginning to indicate that the Lapidus procedure, which is technically challenging and is associated with a relatively high risk of nonunion and a high complication rate, may be an avoidable addition to hallux valgus corrective surgery in some cases.
Hallux rigidus is characterized by pain and limited range of motion of the first metatarsophalangeal joint. The symptoms of hallux rigidus can produce an altered gait and a plantar loading pattern when patients attempt to avoid pain and compensate for motion restriction at the first metatarsophalangeal joint. In a prospectively designed study, Nawoczenski et al. used plantar pressure patterns and three-dimensional joint kinematics to evaluate the effect of cheilectomy on first metatarsophalangeal joint motion and loading characteristics24. The plantar pressures demonstrated a tendency to shift medially following cheilectomy. Significant increases were found in first metatarsophalangeal joint active dorsiflexion and dorsiflexion motion with gait. The authors concluded that although cheilectomy restores some balance to plantar loading and increases first metatarsophalangeal joint motion, the kinematics of gait continue to be altered and may contribute to further degeneration of the joint. Kirane et al. investigated the role of stenosing tenosynovitis of the flexor hallucis longus tendon, as manifested by limited distal excursion, in the etiology of hallux rigidus25. Cadaver specimens were placed in a Robotic Dynamic Activity Simulator to simulate the stance phase of gait. The flexor hallucis longus tendon was held 2, 4, and 6 mm proximal to the midpoint of its normal excursion to simulate progressive stenosis. Measurements were then recorded to derive the in situ forces and moments imparted on the metatarsal and the first metatarsophalangeal joint. With the flexor hallucis longus held in simulated restrictive stenosis, the forces in the flexor hallucis longus tendon, the first metatarsal compressive force, and the first metatarsophalangeal joint-reaction force were significantly greater. The magnitude of the first metatarsophalangeal joint-reaction force also correlated with the tensile force in the flexor hallucis longus tendon. That biomechanical study supported the authors' hypothesis that a tight flexor hallucis longus tendon, as occurs in stenosing tenosynovitis, would alter joint mechanics of the first metatarsophalangeal joint and could contribute to the development of degenerative arthritis. The search for a reliable motion-sparing alternative to arthrodesis in the treatment of advanced hallux rigidus continues, although few comparative studies are available in the literature. In a retrospective case-control study, Raikin et al. compared the intermediate-term outcomes of arthrodesis and metallic hemiarthroplasty (BioPro, Port Huron, Michigan) of the hallux metatarsophalangeal joint26. Twenty-one hemiarthroplasties and twenty-seven arthrodeses were evaluated at a mean of 79.4 months of follow-up. Five (24%) of the hemiarthroplasties failed; one underwent revision hemiarthroplasty, whereas the other four were converted successfully to arthrodesis. For the sixteen hemiarthroplasties that survived, the mean AOFAS score increased from 35.6 of 100 points preoperatively to 71.8 of 100 points postoperatively; however, eight implants demonstrated radiographic evidence of cutout of the distal peg of the implant through the plantar cortex of the proximal phalanx. All thirteen implants available for radiographic examination also demonstrated dorsal subsidence at the time of the latest follow-up. The arthrodesis group had significantly higher postoperative AOFAS scores, with the mean score increasing from 36.1 points to 83.8 points, as well as significantly lower visual analog scale pain scores at the time of the latest follow-up. All patients in the arthrodesis group achieved a successful fusion by three months after surgery. Currently, arthrodesis remains more predictable than metallic hemiarthroplasty is for alleviating symptoms and restoring function in patients with advanced hallux rigidus. Hallux rigidus is one of the most common causes of forefoot pain, yet a formal classification system has yet to be devised. Beeson et al. performed a review of the literature in order to determine if a "gold standard" classification system for hallux rigidus exists27. Eighteen formal hallux rigidus classification systems that were based on radiographic appearance and/or clinical findings were identified; however, different criteria and methods were used in their construction. Additionally, no classification systems had been rigorously tested for reliability or validity, and all were based mainly on clinical experience rather than formal research. That study underscores the need to develop a classification system based on properly constructed prospectively designed studies for a disease as common as hallux rigidus.
The foot and ankle surgeon commonly employs temporary postoperative immobilization of the lower extremity to achieve a successful result. Although many commercial immobilization devices are available in addition to standard fiberglass casts, we are not aware of any studies that have compared their relative stabilities. Kadakia et al. compared the sagittal plane stability of five different types of immobilization devices that are commonly used for foot and ankle surgery28. Lateral radiographs were made with the ankle in maximum dorsiflexion and plantar flexion after healthy volunteers were fitted into fiberglass short-leg casts followed by four different types of off-the-shelf braces. The commercial braces used were the FP Walker (foam pneumatic) (Aircast, Summit, New Jersey), the XP Walker (pneumatic) (Aircast), the SP Walker (Aircast), and the MaxTrax Walker (DonJoy, Vista, California). The cast demonstrated significantly greater sagittal plane motion restriction in comparison with all of the commercial braces. That study reinforces the idea that if maximum restriction of sagittal plane motion is necessary, a fiberglass cast offers more stability than most commercial braces do.
In a prospective, randomized, controlled, single-blind study, Samuel et al. compared the analgesic efficacy of a combined popliteal and ankle block with that of an ankle block alone following forefoot surgery29. Pain scores, as assessed with a visual analog scale, were lower in the combined-block group at all postoperative time periods, with a significant difference noted at six and twenty-four hours postoperatively and at the time of discharge. Ninety-six percent of the patients in the combined-block group were satisfied or very satisfied, compared with 76% of those in the ankle block group. No significant difference was found in terms of the analgesic medication dosing requirement or the mean time to administration of the first analgesic. That study suggests that the addition of a popliteal block to an ankle block reduces the postoperative pain of forefoot surgery beyond the effect of an ankle block alone.
A dearth of published evidence and a low rate of thromboembolism continue to make thromboprophylaxis following foot and ankle surgery a controversial issue. An e-mail survey was performed by Gadgil and Thomas to determine patterns of thromboembolic prophylaxis among foot and ankle surgeons30. The survey was sent to 455 members of the AOFAS or the British Orthopaedic Foot Surgery Society (BOFSS), and 140 replies were received, for a response rate of 31%. Overall, 19% of the surgeons reported the routine use of thromboprophylaxis for elective or trauma foot and ankle surgery. The most common situations for the utilization of thromboprophylaxis were elective hindfoot surgery, open reduction and internal fixation of the ankle, and nonoperative treatment of trauma. The survey results demonstrated wide variability in the types of treatment employed, with aspirin being the most common method of prophylaxis reported by AOFAS members and low-molecular-weight heparin being the most common method reported by BOFSS members. That study demonstrates the continued lack of consensus and wide treatment variability among foot and ankle surgeons with regard to the prevention of deep venous thrombosis and pulmonary embolism. Krenek et al. used observational, population-based data from all inpatient admissions in California over an eleven-year period to identify the rates and patient-related factors predictive of readmission for the treatment of deep venous thrombosis or pulmonary embolism following the open reduction and internal fixation of ankle fractures31. During the eleven-year time frame, 57,183 open reduction and internal fixation procedures were performed for the treatment of ankle fractures. The overall rates of readmission for the treatment of pulmonary embolism and deep venous thrombosis were low (0.34 % and 0.05%, respectively). The low rates of thrombosis and thromboembolic disease following foot and ankle surgery are consistent with the low rates reported in previous studies. The higher risks associated with anticoagulation treatment do not appear to justify the routine use of thromboprophylaxis following foot and ankle surgery. The role of the calf muscles and the importance of ankle joint motion in improving venous return from the lower extremity are well established, but the venous circulation of the great toe and the first metatarsophalangeal joint has been largely ignored. Elsner et al. performed a sophisticated cadaver dissection with use of digestive enzymes, plastination techniques, vessel infiltration, and tissue maceration to map out the anatomy of the soft tissues and venous anatomy surrounding the first metatarsophalangeal joint32. Dissection revealed a venous network with functional valves oriented in a fashion parallel to the flexor hallucis longus tendon. Interwoven among the venous network was connective tissue, with thick bands connecting the veins to the flexor hallucis longus tendon and the first metatarsophalangeal joint capsule. Additionally, forty patients underwent biphasic Doppler flow studies of the great toe at rest and following passive and active toe motion. Both passive and active motion of the first metatarsophalangeal joint produced a significant increase in venous flow. The authors suggested that the venous anatomy of the great toe and its connections to the flexor hallucis longus tendon and first metatarsophalangeal joint capsule produce a "metatarsophalangeal pump." Extension of the great toe compresses the venous lumen, allowing for an increase in proximal venous blood flow. The formal description of this venous anatomy underscores the importance of toe motion in edema reduction and possible thromboprophylactic therapy following foot and ankle injuries and surgery.
The editorial staff of The Journal reviewed a large number of recently published research studies related to the musculoskeletal system that received a Level of Evidence grade of I or II. Over 100 medical journals were reviewed to identify these articles, which all have high-quality study design. In addition to articles published previously in this journal or cited already in the Update, six additional level-I and II studies were identified that were relevant to foot and ankle surgery. A list of those titles is appended to this review after the standard bibliography. We have provided a brief commentary about each of the articles to help guide your further reading, in an evidence-based fashion, in this subspecialty area.
There are several upcoming courses and events relevant to foot and ankle surgery sponsored or cosponsored by the AAOS, AOFAS, and Arthroscopy Association of North America (AANA).
van Rijn RM, van Os AG, Bernsen RM, Luijsterburg PA, Koes BW, Bierma-Zeinstra SM. What is the clinical course of acute ankle sprains? A systematic literature review. Am J Med. 2008;121:324-31.e6. Acute lateral ankle sprains are one of the most common musculoskeletal injuries, yet their clinical course following conservative treatment remains poorly described and therefore not well understood. This systematic review of the literature sought to shed light on the course of recovery after an acute lateral ankle injury and to evaluate potential factors for nonrecovery and repeat sprains. Thirty-one studies met the methodologic quality criteria for inclusion in the review, of which twenty-four were considered to be of high quality. The review showed a rapid decrease in pain in the first two weeks following an acute lateral ankle injury. Improvement continued at a slower pace following the initial two weeks; however, 5% to 33% of patients still continued to experience pain after one year. At three years of follow-up, residual symptoms remained for some patients, and the factors influencing those persistent complaints remain unknown. A wide variation was noted in the reported symptoms of subjective instability, repeat sprains, and subjective recovery. Although substantial research has been dedicated to understanding this injury, there remains a need for studies of high methodologic quality to investigate the prognostic factors and variables that contribute to incomplete recovery of acute lateral ankle sprains. van Rijn RM, van Os AG, Kleinrensink GJ, Bernsen RM, Verhaar JA, Koes BW, Bierma-Zeinstra SM. Supervised exercises for adults with acute lateral ankle sprain: a randomised controlled trial. Br J Gen Pract. 2007;57:793-800. In this randomized controlled trial, conventional treatment alone was compared with conventional treatment combined with a progressive training program supervised by a physiotherapist for the management of acute lateral ankle sprains. The group that received conventional treatment alone received information about early ankle motion and advice on home exercises and early weight-bearing. The group that received conventional treatment along with supervised physical therapy had a mean of 6.1 treatment sessions, within a period of three months, emphasizing balance exercises, walking, running, and jumping. After three months and one year of follow-up, no significant difference was found between the two groups in terms of subjective recovery or the occurrence of repeat sprains. This study does not support supplementing conventional treatment with a supervised physical therapy program for the treatment of acute lateral ankle sprains. Twaddle BC, Poon P. Early motion for Achilles tendon ruptures: is surgery important? A randomized, prospective study. Am J Sports Med. 2007;35:2033-8. Previous studies on acute Achilles tendon ruptures have demonstrated increased strength and lower rerupture rates when surgery combined with controlled early motion has been compared with no surgery and prolonged cast immobilization. The authors of this prospective randomized study extrapolated on research demonstrating the benefits of motion on tendon-healing in order to investigate the influence of controlled early motion on nonoperatively treated Achilles tendon ruptures. Patients in both the operative and nonoperative treatment groups abided by the same rehabilitation protocol, which included ten days of treatment with an equinus cast followed by the use of a below-the-knee orthosis. After removal of the cast, patients were allowed to perform active ankle dorsiflexion and passive plantar flexion. The orthosis was placed in a neutral position by four weeks, weight-bearing was progressed by six weeks, and toe-raises were encouraged at eight weeks. No significant difference was found between the two groups in terms of range of motion, calf circumference, or outcomes scores measured at two, eight, twelve, twenty-six, or fifty-two weeks. No complications occurred in the operative treatment group, and both groups had similarly low rerupture rates. These results suggest that controlled early motion may be the most important part of the treatment of an acutely ruptured Achilles tendon instead of operative repair; however, larger studies with longer follow-up must be performed to corroborate these findings. Rasmussen S, Christensen M, Mathiesen I, Simonson O. Shockwave therapy for chronic Achilles tendinopathy: a double-blind, randomized clinical trial of efficacy. Acta Orthop. 2008;79:249-56. The effect of low-energy extracorporeal shock-wave therapy (ESWT) as a supplement to conservative treatment of chronic Achilles tedinopathy was investigated in this double-blind, randomized clinical trial. Patients received either extracorporeal shock-wave therapy or placebo therapy in which the same machine device was used to deliver a sham dose as a supplement to conservative treatment (stretching and eccentric training). Both groups demonstrated improvement in terms of the mean AOFAS score, but the intervention group demonstrated significantly greater improvement over time than the control group did. Visual analog pain scale scores improved for both groups; however, no difference in improvement was detected between the treatment groups. Extracorporeal shock-wave therapy appears to improve outcomes when used as a supplement to stretching and eccentric training in the treatment of chronic Achilles tendinopathy. Kane TP, Ismail M, Calder JD. Topical glyceryl trinitrate and noninsertional Achilles tendinopathy: a clinical and cellular investigation. Am J Sports Med. 2008;36:1160-3. Topical glyceryl trinitrate has been used with some success for the treatment of chronic extensor and supraspinatus tendinopathies. Glyceryl trinitrate also has been extended to the treatment of noninsertional Achilles tendinopathy, despite limited supporting evidence. This randomized, single-blinded study compared the outcomes of treatment with glyceryl trinitrate and physical therapy with those of treatment with physical therapy alone in patients with noninsertional Achilles tendinopathy. Although improvement was noted in both groups, glyceryl trinitrate did not offer any additional clinical benefit over standard nonoperative treatment. Three patients in the physiotherapy group and four patients in the glyceryl trinitrate plus physiotherapy group had a failure of conservative treatment and underwent surgical débridement of the Achilles tendon. Histologic examination of the diseased tendon following surgery did not demonstrate any detectable neovascularization, fibroblast activity, or collagen synthesis in either group. These results do not support the continued use of glyceryl trinitrate patches for the treatment of noninsertional Achilles tendinopathy. Leese G, Schofield C, McMurray B, Libby G, Golden J, MacAlpine R, Cunningham S, Morris A, Flett M, Griffiths G. Scottish foot ulcer risk score predicts foot ulcer healing in a regional specialist foot clinic. Diabetes Care. 2007;30:2064-9. The authors of this study used the Scottish Care Information-Diabetes Collaboration (SCI-DC) ulcer risk score in a retrospective fashion to determine if the risk score predicted ulcer development and could predict ulcer healing. Overall, 221 ulcers were included in the analysis. Sixty-eight percent of the patients were previously categorized as being at high risk for ulcer formation, and 98% were categorized as being at high or moderate risk. The healing rate was significantly lower in high-risk patients as compared with the low and moderate-risk patients (68% compared with 93%). Factors associated with poor healing were absent pulses, neuropathy, increased patient age, and the presence of deep rather than superficial ulcers. The results of this study suggest that the SCI-DC risk score can be useful for the prediction of ulcer development and healing rates.
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