Jan Willem K. Louwerens

Stress Radiography of the Talocrural and Subtalar Joints

The object of this investigation was to determine a possible subtalar component in a group of 33 patients with chronic ankle instability. A group of 10 subjects without ankle/foot symptoms acted as controls. A standardized radiographic assessment of talar and simultaneous subtalar tilt was made. A hinge device to stress the joints and a specific subtalar stress view (Brodén view) were used under fluoroscopic control. Radiographs were made with the feet: (1) in neutral position, (2) after inversion with moderate force until the point of fair restraint (step 1), and (3) after inverting with more force as far as the conditions would allow (step 2). An increase of talar tilt between step 1 and step 2 was only found in feet that were symptomatic. This suggests that this increase is only possible when lateral ligaments are damaged. Further research is necessary to determine whether this finding can serve as a parameter to discriminate between physiological and abnormal talar tilt. A wide range of subtalar motion was found in both symptomatic and asymptomatic feet. With the present method, practically all subtalar joints showed some loss of congruity and medial shift of the calcaneus in relation to the talus. This could not be correlated with ankle instability at the talocrural joint. The consequence of the use of different subtalar stress methods has so far received little attention and is discussed.

Peroneus longus and tibialis anterior muscle activity in the stance phase A quantified electromyographic study of 10 controls and 25 patients with chronic ankle instability

The electromyographic activity of the peroneus longus and anterior tibial muscles of 25 patients with chronic ankle instability (18 patients with bilateral symptoms and 7 patients with unilateral complaints) and 10 controls was registered during the stance phase under different walking conditions. With balance secured by external support, there was a variable amount of peroneal activity, most of which was found in the third quarter of stance. A high increase in peroneus longus activity starting after foot-flat was found when subjects had to maintain balance in a natural way. No difference in peroneal activity was found in relation to instability complaints. It is thought that the peroneus longus serves to maintain balance, that this function decreases with increase of speed and that one cannot rely on this muscle to prevent an inversion injury during normal walking. The anterior tibial muscle was predominantly active in the first quarter after heel contact. An increase in activity in the second quarter as an effect of loss of secured balance suggests that this muscle plays some part in balance control, but this is not its main function. A significant increase in tibialis anterior activity was found in patients with bilateral instability. No significant difference was found between the symptomatic and asymptomatic leg of patients with unilateral instability under the same walking conditions. These findings suggest changes in central control.

Stress Radiography and Stress Examination of the Talocrural and Subtalar Joint on Helical Computed Tomography

The main objective of this study was to compare subtalar inversion stress views using the Brodén view with inversion stress views on helical computed tomography (CT). One of the drawbacks of routine radiography is the imaging of three-dimensional structures in a two-dimensional plane. We investigated whether the use of helical CT would lead to a more objective and clearer measurable method to determine the amount of tilt in the subtalar joint. A group of 15 patients with unilateral chronic instability complaints and clinically suspected subtalar instability was examined. The contralateral asymptomatic foot was used as control. A variable amount of subtalar tilt (range, 4° to 18°) was demonstrated in all cases on stress radiographs, without finding significant difference between the symptomatic and asymptomatic feet. However, contrary to the findings at the talocrural level, subtalar tilt was found in none of the patients using helical CT. Thus, we now doubt that the tilt seen during stress examination using the Brodén view is the true amount of tilt. It may be that the lateral opening, seen on these radiographs, largely results from imaging two planes that have made a translatory and rotatory movement relative to each other in an oblique direction. It is concluded that the Brodén stress examination might not be useful for screening patients with subtalar instability. Associated anomalies not visible on the radiographs were detected by helical CT. In four cases, narrowing of the articular cartilage and irregular and hypertrophic bone formation at the middle facet joint of the subtalar joints were found. It is likely that these changes cause disturbance of function of this joint and it is suggested that the subjective complaint of instability with “giving way” is not only caused by hypermobility, but can be caused by other disturbances of normal motion.

Posterior Tibial Tendon Transfer: Results of Fixation to the Dorsiflexors Proximal to the Ankle Joint

Background: Most techniques for posterior tibial tendon transfer attach the posterior tibial tendon somewhere at the dorsum of the foot. Inadequate tendon length and difficulties in securing the tendon to bone or tendon can complicate these procedures. Performing the tenodesis proximal to the ankle joint can prevent these problems. The present study is the first to describe the results of posterior tibial tendon transfer through the interosseous membrane attaching only the posterior tibial tendon to the extensor tendons proximal to the ankle joint. Methods: We examined 13 feet in 12 patients with a foot-drop, equinovarus deformity, or both. The median (range) followup was 3.7 years (9 to 81 months) and the median age at surgery as 30 (13 to 59) years. Evaluation included recording patient satisfaction, use of ankle-foot orthoses (AFO), video-assisted gait analysis, physical examination, the Stanmore system, modified Ninković method, and complications. Results: At followup, patient satisfaction was excellent to good in nine feet. Ten of the 11 feet that needed an AFO preoperatively did not need one after surgery. Gait analysis demonstrated a good to fair gait in 10 patients. Median dorsiflexion was 0 (−25 to 12) degrees, with dorsiflexion to a neutral position or beyond in nine feet. The Stanmore system and modified Ninković method showed excellent to good results in 10 feet. Three complications were recorded including one failed tendon transfer. Conclusions: Attachment of a split posterior tibial tendon to the extensor tendons proximal to the ankle joint provides results equivalent to other procedures and can be considered a viable operative alternative because it is less difficult and more straightforward than other techniques.

Comparison of the Short-Term Results of the First and Last 50 Scandinavian Total Ankle Replacements Assessment of the Learning Curve in a Consecutive Series

Background: Total ankle replacement (TAR) is presently considered to be an acceptable alternative to ankle fusion for patients with debilitating conditions of the ankle. The placing of a total ankle prosthesis is a technically demanding procedure. We hypothesized that the challenging conditions could cause a longer learning curve (>30 cases), and therefore the short-term results of the first and the last 50 cases in a consecutive series of 134 cases were compared. Methods: The first and last consecutive 50 cases by a single surgeon in a series of 134 Scandinavian Total Ankle Replacements (STAR; Waldemar Link, Hamburg, Germany), inserted between May 1999 and May 2008, were evaluated. Operation characteristics, clinical outcome (Foot Function Index [FFI], Kofoed score), complications, and the component alignment on X-rays were assessed. The outcome measures for both groups were compared using independent Student t tests, chi-square tests, and nonparametric alternatives (P < .05). Results: Surgery time decreased from a median of 125 (83-160) to 100 (65-170) minutes (P < .001), and fewer perioperative complications were observed (12 vs 4, P = .04). The sagittal alignment of the tibial component was closer to normal in the last series (P < .001). The clinical outcome did not differ between the 2 series (median FFI: 32 [0-74] vs 25 [0-75], Kofoed score: median 71 [21-96] vs 80.5 [23-100]). The major underlying pathology did change from rheumatoid arthritis (60%) to osteoarthritis (44%; P = .002). No differences in type and number of complications were reported. Conclusion: The surgery time did decrease, there were fewer perioperative fractures, and the tibial component orientation improved, suggesting the presence of a learning curve. Operative experience and a shift in major underlying pathology did not influence clinical outcome. In view of this learning curve we suggest more restrictive patient selection for at least the first 50 TARs. Level of Evidence: Level III, comparative series.

Foot Function After Fusion of the First Metatarsophalangeal Joint

Background: We measured with a validated score the operative outcome in patients without concomitant foot surgery who underwent fusion of the first metatarsophalangeal (MTP) joint for hallux rigidus (HR) and hallux valgus (HV). We also examined whether there is a correlation between foot function and hallux position to try to formulate an optimum fusion angle. Materials and Methods: Between 2002 and 2005, a consecutive series of 62 patients underwent crossed screw fusion of the first MTP joint (27 HR and 35 HV) without concomitant surgery of the same or contralateral foot or had previous surgery of the same foot. Foot function was measured by the Dutch Foot Function Index (FFI) pre- and postoperatively. Hallux valgus and dorsiflexion angles were measured on standing radiographs before operation and at followup. Results: Postoperatively the median hallux valgus angle was 14 (range, −2 to 33) degrees and the median dorsiflexion angle was 23 (range, 7 to 45) degrees. The median FFI score improved from 38 (range, 0 to 80) to 8 (range, 0 to 59) (p < 0.001). The FFI score was not different between the HV and HR groups. There was no correlation between postoperative foot function, dorsiflexion angles and hallux valgus angles. Conclusion: Fusion of the first MTP joint in HR and HV results in improved function according to the validated FFI. There was no significant correlation between foot function and hallux position. This could be due to the fact that the desired position of the hallux was most often achieved. Level of Evidence: II, Prospective Comparative Study

Definitions of hammer toe and claw toe: an evaluation of the literature.

BACKGROUND Lesser toe surgery is among the most conducted interventions in general orthopedic practice. However, the definitions of hammer toe and claw toe are not uniform. The objective of this literature study is to propose clear definitions for these deformities to establish unambiguous communication. METHODS A literature search was performed in the PubMed database (May 2006). Of 81 eligible articles, 42 that stated a clear definition of hammer toe or claw toe were selected. RESULTS In all 35 articles in which hammer toe was clearly defined, flexion in the proximal interphalangeal joint was part of the definition. Seventeen articles (49%) defined hammer toe as a combination of metatarsophalangeal extension and proximal interphalangeal flexion. Thirteen articles showed flexion of the proximal interphalangeal joint as the single criterion. Twenty-three articles with a clear definition of claw toe were selected. Twenty-one articles (91%) showed metatarsophalangeal extension as part of the claw toe deformity. Twelve articles (52%) regarded metatarsophalangeal extension and flexion of the proximal interphalangeal and distal interphalangeal joints as the essential characteristics. Seven articles described a claw toe as metatarsophalangeal extension with flexion in the proximal interphalangeal joint. CONCLUSIONS There are variations in the definitions of lesser toe deformities in the literature. We propose that extension of the metatarsophalangeal joint is the discriminating factor and essential characteristic for claw toe. Claw toe and hammer toe should be characterized by flexion in the proximal interphalangeal joint, which is the single criterion for a hammer toe. The flexibility of these joints could be a basic factor in discriminating between these deformities. The development of these deformities should be regarded as a continuum in the same pathophysiologic process.

Rheumatoid forefoot deformity: pathophysiology, evaluation and operative treatment options

Despite recent advances in pharmacological management of rheumatoid arthritis, forefoot deformity, with its symptoms, remains a common problem, often requiring operative treatment. Typical deformities in these patients comprise hallux valgus and deformity of the lesser metatarsophalangeal (MTP) joints and toes. With regard to the lesser rays the standard operative procedure, advocated for the disabling forefoot pain in these patients, remains metatarsal head resection. It should be considered that with increasing success of pharmacological treatment the degree of forefoot deformity in these patients is becoming less and that resection of the lesser MTP joints is becoming more and more superfluous. This supports a trend towards metatarsal head-preserving surgery. The optimal treatment of the hallux deformity remains unclear. Fusion of the first MTP joint is, generally, recommended. This article will discuss the current surgical options in rheumatoid forefoot pathology.

Plantar pressure with and without custom insoles in patients with common foot complaints.

Background: Although many patients with foot complaints receive customized insoles, the choice for an insole design can vary largely among foot experts. To investigate the variety of insole designs used in daily practice, the insole design and its effect on plantar pressure distribution were investigated in a large group of patients. Materials and Methods: Mean, peak, and pressure-time-integral per sensor for 204 subjects with common foot complaints for walking with and without insoles was measured with the footscan® insole system (RSscan International). Each insole was scanned twice (precision3D), after which the insole height along the longitudinal and transversal cross section was calculated. Subjects were assigned to subgroups based on complaint and medial arch height. Data were analyzed for the total group and for the separate subgroups (forefoot or heel pain group and flat, normal or high medial arch group). Results: The mean pressure significantly decreased under the metatarsal heads II-V and the calcaneus and significantly increased under the metatarsal bones and the lateral foot (p < 0.0045) due to the insoles. However, similar redistribution patterns were found for the different foot complaints and arch heights. There was a slight difference in insole design between the subgroups; the heel cup was significantly higher and the midfoot support lower for the heel pain group compared to the forefoot pain group. The midfoot support was lowest in the flat arch group compared to the high and normal arch group (p < 0.05). Conclusion: Although the insole shape was specific for the kind of foot complaint and arch height, the differences in shape were very small and the plantar pressure redistribution was similar for all groups. Clinical Relevance: This study indicates that it might be sufficient to create basic insoles for particular patient groups.

Opinions on Lesser Toe Deformities Among Dutch Orthopaedic Departments

Background: Wide variations in definitions of lesser toe deformities exist. In addition, a general consensus regarding treatment of lesser toe deformities is lacking. The objective of this study was to evaluate of the definitions, current concepts, and treatment protocols for lesser toe deformities among orthopaedic departments in The Netherlands. Methods: A questionnaire with statements regarding lesser toe deformities was sent to all 101 Dutch departments of orthopaedic surgery. Results: In total 76 (75%) completed forms were analyzed. A wide variation regarding definitions, concepts, and treatment strategies of lesser toe deformities was reported among the Dutch orthopaedic departments. Only half of all responding departments had a protocol or consensus in the treatment. Conclusions: The definitions of lesser toe deformities used in Dutch orthopaedic departments do not coincide. This might explain the variations in indications and the various performed interventions for different deformities. The differences of opinion among the Dutch orthpaedic departments may have important clinical consequences because an indication for surgery depends on the correct diagnosis. To correctly interpret and improve treatment results, a consensus on this topic should be introduced.