Loss of Mechanical Ankle Function Is Not Compensated by the Distal Foot Joints in Patients with Ankle Osteoarthritis

BACKGROUND

Patients with isolated ankle osteoarthritis (OA) often demonstrate disturbed ankle biomechanics during walking. Clinicians often believe that this triggers the distal foot joints to compensate these altered ankle biomechanics and that these foot joints are consequently subjected to degenerative joint diseases due to overuse.

QUESTIONS/PURPOSES

Do patients with isolated ankle OA differ from those without ankle OA in terms of (1) ankle and foot joint kinematics and (2) ankle and foot joint kinetics as measured using three-dimensional (3-D) gait analysis? (3) Do these patients demonstrate compensatory strategies in their Chopart, Lisfranc, or first metatarsophalangeal joints in terms of increased joint kinematic and kinetic outputs?

METHODS

Between 2015 and 2018, we treated 110 patients with unilateral ankle OA, and invited all of them to participate in the gait analysis laboratory. Of those, 47% (52) of patients did so, and of these, 16 patients met the inclusion criteria for this study, which were (1) diagnosis of unilateral ankle OA; (2) absence of radiographical signs of OA in the contralateral foot or lower limbs; (3) ability to walk at least 100 m without rest; and (4) being older than 18 years of age. A control group (n = 25) was recruited through intranet advertisements at the University Hospitals of Leuven. Participants were included if their age matched the age-range of the patient group and if they had no history of OA in any of the lower limb joints. Patients were slightly older (55.9 ± 11.2 years), with a slightly higher BMI (28 ± 6 kg/m2) than the control group participants (47.2 ± 4.4 years; p = 0.01 and 25 ± 3 kg/m2; p = 0.05). All participants underwent a 3-D gait analysis, during which a multisegment foot model was used to quantify the kinematic parameters (joint angles and ROM) and the kinetic parameters (rotational forces or moments), as well as power generation and absorption in the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during the stance phase of walking. Peak values were the maximum and minimum values of waveforms and the latter were time-normalized to 100% of the stance phase.

RESULTS

Regarding joint kinematics, patients demonstrated a sagittal plane ankle, Chopart, Lisfranc, and first metatarsophalangeal joint ROM of 11.4 ± 3.1°, 9.7 ± 2.7°, 8.6 ± 2.3° and 34.6 ± 8.1°, respectively, compared with 18.0 ± 2.7° (p < 0.001), 13.9 ± 3.2° (p < 0.001), 7.1 ± 2.0° (p = 0.046) and 38.1 ± 6.5° (p = 0.15), respectively, in the control group during the stance phase of walking. With regard to joint kinetics in the patient group, we found a mean decrease of 1.3 W/kg (95% CI confidence interval 1.0 to 1.6) (control group mean: 2.4 ± 0.4 W/kg, patient group mean: 1.1 ± 0.5 W/kg) and 0.8 W/kg (95% CI 0.4 to 1.0) (control group mean: 1.5 ± 0.3 W/kg, patient group mean: 0.7 ± 0.5 W/kg) of ankle (p < 0.001) and Chopart (p < 0.001) joint peak power generation. No changes in kinetic parameters (joint moment or power) were observed in any of the distal foot joints.

CONCLUSION

The findings of this study showed a decrease in ankle kinematics and kinetics of patients with isolated ankle OA during walking, whereas no change in kinematic or kinetic functions were observed in the distal foot joints, demonstrating that these do not compensate for the mechanical dysfunction of the ankle.

CLINICAL RELEVANCE

The current findings suggest that future experimental laboratory studies should look at whether tibiotalar joint fusion or total ankle replacement influence the biomechanical functioning of these distal joints.

Intrinsic Fixation of the Tibial Sesamoid in First Metatarsophalangeal Joint Arthrodesis: A Cadaveric Study

Nonunion rate of first metatarsophalangeal joint (MTP) joint arthrodesis is reportedly less than 6%, regardless of fixation type. Robust modern plating constructs aim to decrease incidence of nonunion while also allowing early postoperative weight-bearing. Quicker transition to weight-bearing postoperatively increases patient adherence, decreases adjacent joint stiffness, and reduces risk of deep vein thrombosis in the postoperative period. The purpose of this study was to investigate the effect tibial sesamoid fixation has on first MTP joint arthrodesis.

Reliability of a new dynamic ultrasound test for quantifying first-ray mobility

BACKGROUND

First-ray hypermobility (FRHM) is a documented abnormality whose pathogenic role is controversial. FRHM has been suggested to participate in many common disorders such as paediatric hallux valgus and recurrence after hallux valgus surgery. The controversy is due to lack of functional data on the first tarso-metatarsal joint (TMT1) in real-life situations, to its major anatomical variability, and to the absence of simple investigation methods. The objective of this study was to assess the feasibility and the inter- and intra-observer reproducibility of a new dynamic ultrasound test that quantifies TMT1 mobility and is simple to use provided a good-quality ultrasound machine is available.

HYPOTHESIS

The new ultrasound TMT1 mobility test is reproducible.

MATERIAL AND METHODS

The 32 feet of 16 consecutive patients whose first ray was considered normal were included. Ultrasonography was performed at rest and during a stress test consisting in causing TMT1 gaping by applying a distal dorsal drawer movement to the first metatarsal. The two plantar bony prominences on either side of the TMT1 were identified, and the distance between them was measured at rest and during the stress test. The stress/rest ratio was computed. Each foot was tested twice by two different examiners, for a total of 128 tests.

RESULTS

Mean TMT1 gaping distance was 1.38mm (range, 1.01-2.02mm) at rest and 1.67mm (range, 1.12-2.95mm). The mean stress/rest ratio was 1.21 (range, 1.02-1.62). Both inter- and intra-observer reliability was strong for all measured parameters.

DISCUSSION

A simple and reproducible ultrasound test for measuring TMT1 mobility is described for the first time. The good reproducibility confirms the working hypothesis. This preliminary study was designed to validate the new test. The measured values need to be assessed in various disorders including FRHM, for which the test was designed. Should the results prove conclusive, the TMT1 gaping test may become a pivotal diagnostic tool.

LEVEL OF EVIDENCE

IV, diagnostic study.

Centre of pressure characteristics during walking in individuals with and without first metatarsophalangeal joint osteoarthritis

OBJECTIVE

The objective of this study was to compare centre of pressure characteristics during walking in individuals with and without first metatarsophalangeal joint osteoarthritis (1st MTPJ OA), in order to provide insights into alterations in foot function associated with this condition.

METHODS

Twenty people with 1st MTPJ OA and 20 asymptomatic controls matched for age, sex and body mass index underwent gait analysis using the emed^®-x400 plantar pressure system (Novel GmbH, Germany). Average and maximum centre of pressure velocity and lateral-medial force index during loading, midstance, terminal stance and preswing were compared between the groups.

RESULTS

During the preswing phase of gait, maximum centre of pressure velocity was significantly slower in individuals with 1st MTPJ OA (0.78 ± 0.19 vs 1.13 ± 0.36 m/sec; p = 0.003), and both average and maximum lateral-medial force indices were significantly higher in individuals with 1st MTPJ OA (0.98 ± 0.14 vs 0.82 ± 0.13; p < 0.001 and 1.37 ± 0.29 vs 1.15 ± 0.15; p = 0.008, respectively). Non-weightbearing 1st MTPJ dorsiflexion range of motion was significantly associated with maximum centre of pressure velocity (r = 0.54, p < 0.001) and average lateral-medial force index (r = -0.44, p = 0.004) during preswing.

CONCLUSIONS

Individuals with 1st MTPJ OA exhibit significant differences in centre of pressure characteristics during propulsion, possibly due to decreased range of available 1st MTPJ dorsiflexion.

Surgical correction of hallux valgus deformity in children with cerebral palsy

Objective

This study aimed to present a treatment algorithm for the correction of the hallux valgus deformity in Cerebral Palsy (CP) patients and to discuss the outcomes based on our clinical and radiological results.

Methods

29 patients (45 feet) were included in the study. The mean age of the patients at the time of the surgery was 14 (range 6–22) years. The mean follow-up was 33 (range 22–59) months. A reconstructive procedure was performed on 19 patients (27 feet); a soft tissue surgery and exostectomy of the bunion in six patients (11 feet); and MTP joint arthrodesis in four patients (7 feet). The hallux valgus angle (HVA) and the anteroposterior intermetatarsal angle (IMA) were used for radiologic evaluation and the DuPont Bunion Rating Score was used for clinical evaluation.

Results

The follow-up period was 36 (range 22–59) months in reconstructive group, 27 (range 24–29) months in soft tissue group, and 29 (range 23–41) months in MTP arthrodesis group. Significant improvements were detected in hallux valgus angle in three groups postoperatively but in soft tissue group correction loss was observed during follow up. Best results were achieved in arthrodesis group and worse in soft tissue group in terms of clinical evaluation.

Conclusion

According to our results isolated soft tissue procedures are ineffective in CP patients. Soft tissue procedure combined with metatarsal osteotomy has satisfactory results.

Level of evidence

Level IV, therapeutic study.

Clinical and Radiologic Outcomes of Metatarsophalangeal Hemiarthroplasty: A Review of 12 Consecutive Cases

This study examined function, pain, satisfaction, and radiologic outcomes among patients treated with first metatarsophalangeal hemiarthroplasty. Patients were invited to participate in an outcome study conducted with questionnaires on subjective and objective outcomes and clinical and radiographic follow-up. A total of 12 patients (12 feet; mean patient age, 58.8±12.3 years) agreed to participate. Mean follow-up was 22.3±19.8 months. Of these patients, 7 were satisfied with the postoperative result. The mean visual analog scale pain score decreased significantly from 7.0±2.3 preoperatively to 3.5±3.3 postoperatively (P=.024). Mean passive range of motion of the first metatarsophalangeal joint was 32°±10° preoperatively, 93°±18° intraoperatively after implantation of the prosthesis and closure of the joint capsule, and 38°±19° at final follow-up (P=.26). Mean American Orthopaedic Foot and Ankle Society forefoot score increased significantly from 47.3±14.7 preoperatively to 71.8±15.2 at last follow-up (P=.033). During the follow-up period, 6 patients underwent additional procedures: 5 therapeutic joint infiltrations and 1 arthrodesis. No patients had radiologic loosening of the implant at final follow-up. Osseous dysplastic changes at the base of the proximal phalanx were noted among 6 of 11 patients (12 total cases) at final follow-up. Although first metatarsophalangeal hemiarthroplasty provided significant pain reduction at mean follow-up of 22.3 months, range of motion of the first metatarsophalangeal joint was not restored to anticipated levels and there were high rates of patient dissatisfaction and secondary interventions. [Orthopedics. 2018; 41(1):e64-e69.].

Understanding Frontal Plane Correction in Hallux Valgus Repair

Hallux-abducto-valgus or "bunion" surgery is one of the most common surgical procedures for the foot and ankle specialist. As our understanding of the hallux-abducto-valgus deformity has grown, it is becoming clear that the anatomic CORA of the deformity may lie at the tarsometatarsal joint. There is also the component of the 3-dimensional nature of the deformity that may be best addressed at this CORA. With these issues in mind, it was necessary to address the shortcomings of the traditional Lapidus procedure and progress toward more consistent, instrumented steps that could address the 3-dimensional nature of the deformity.

Arthrodesis of the first metatarsophalangeal joint-A biomechanical comparison of four fixation techniques

BACKGROUND

Arthrodesis of the first metatarsophalangeal joint is a commonly performed orthopaedic procedure. The optimum method of fixation and joint surface preparation has yet to be determined.

METHODS

This study compared four fixation techniques: Biomechanical grade sawbones were used. The dorsal plate used was a titanium, anatomically contoured locked plate. Testing was performed using an Instron machine applying force from the plantar aspect of the fused joint. Each fused sample was tested to failure. Stiffness, as calculated from the force-displacement curve, and ultimate load tolerated were recorded for each sample. The method of failure of each sample was also documented.

RESULTS

Constructs arthrodesed using dorsal plate with separate screw groups, regardless of method of joint preparation, were the stiffest (p<0.001). The weakest construct was dorsal plate alone without interfragmenary screw. There was no difference in stiffness between planar and cup-cone joint preparation (p=0.99). Maximum load tolerated was similar when comparing Crossed Screws with dorsal plate with screw with either cup-cone or planar reaming (p=0.93, p=0.89 respectively). Dorsal plating alone tolerated a significantly lower maximum load than Plate with Screw Groups or Crossed Screws (p<0.001).

CONCLUSION

This study confirms that an IFS combined with a dorsally positioned locked-plate is the ideal construct, with the joint preparation technique of little consequence.

Shoe-stiffening inserts for first metatarsophalangeal joint osteoarthritis (the SIMPLE trial): study protocol for a randomised controlled trial

BACKGROUND

This article describes the design of a parallel-group, participant- and assessor-blinded randomised controlled trial comparing the effectiveness of shoe-stiffening inserts versus sham shoe insert(s) for reducing pain associated with first metatarsophalangeal joint (MTPJ) osteoarthritis (OA).

METHODS

Ninety participants with first MTPJ OA will be randomised to receive full-length shoe-stiffening insert(s) (Carbon Fibre Spring Plate, Paris Orthotics, Vancouver, BC, Canada) plus rehabilitation therapy or sham shoe insert(s) plus rehabilitation therapy. Outcome measures will be obtained at baseline, 4, 12, 24 and 52 weeks; the primary endpoint for assessing effectiveness being 12 weeks. The primary outcome measure will be the foot pain domain of the Foot Health Status Questionnaire (FHSQ). Secondary outcome measures will include the function domain of the FHSQ, severity of first MTPJ pain (using a 100-mm Visual Analogue Scale), global change in symptoms (using a 15-point Likert scale), health status (using the Short-Form-12® Version 2.0 and EuroQol (EQ-5D-5L™) questionnaires), use of rescue medication and co-interventions, self-reported adverse events and physical activity levels (using the Incidental and Planned Activity Questionnaire). Data will be analysed using the intention-to-treat principle. Economic analysis (cost-effectiveness and cost-utility) will also be performed. In addition, the kinematic effects of the interventions will be examined at 1 week using a three-dimensional motion analysis system and multisegment foot model.

DISCUSSION

This study will determine whether shoe-stiffening inserts are a cost-effective intervention for relieving pain associated with first MTPJ OA. The biomechanical analysis will provide useful insights into the mechanism of action of the shoe-stiffening inserts.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, identifier: ACTRN12616000552482 . Registered on 28 April 2016.

[Our Experience with the Total Replacement of the First Metatarsophalangeal Joint by Medin PH-flex]

The first metatarsophalangeal (MTP) joint replacement ranks among the treatment methods of patients with hallux rigidus. The paper aims to evaluate the short-term to mid-term outcomes and to present clinical experience with our Medin PH-flex implant. MATERIAL AND METHODS In the period from January 2011 to 2016 we performed total replacement of the first MTP joint in 31 patients, in 4 cases bilaterally. In total, 35 implants were evaluated. The mean age of the patient at the time of surgery was 57.7 years (39-72 years). The surgery was conducted in 29 women and 2 men. The patients were evaluated using the AOFAS score (American Orthopaedic Foot and Ankle Society score), the radiographs were assessed as to the potential occurrence of radiolucent lines, with major stress put on the assessment of the mobility in MTP joint and its position. The pain was assessed based on the VAS score. RESULTS Prior to the joint replacement surgery, the mean AOFAS score in patients was 55.6 (35-65). Postoperatively, the mean AOFAS score was 80.8 (65-95). The pain suffered by patients was evaluated with the use of the Pain Visual Analogue Scale (VAS score). The preoperative mean VAS score was 5 (2-8), whereas the postoperative score improved to mean VAS 2 (0-4). The range of motion was clinically assessed with a goniometer. The mean range of motion of plantar flexion and dorsiflexion was 16.00° (5-35°) and 28.60° (10-55°), respectively. The mean range of motion was 36° (15-60°). No intraoperative complications were observed. In all the patients, the surgical wound healed per primam. In 2 female - (5.7 %) of the whole group of patients who underwent surgery a deep infection occurred, namely 10 and 21 months following the implantation. In both the female patients their condition was managed by joint revision operation and by a simple removal of the implant. DISCUSSION Joint replacement related matters were repeatedly discussed in professional literature. There are many papers published in the literature on this topic. A whole range of the first MTP joint implants of different shapes have been developed, with extremely different clinical results. CONCLUSIONS An appropriately chosen type of the implant, a fitting indication and a correctly applied implantation technique can lead to the desired good outcome. The first MTP joint replacement should be indicated after careful consideration since the management of a potential joint replacement failure can often be very technically challenging and quite mutilating for the patient. The mid-term outcomes of the Medin a.s. first MTP implant seem to be promising. It will, however, be necessary to wait for long-term outcomes in order to evaluate the final benefits of this type of implant in patients with hallux rigidus. Key words: hallux rigidus, arthroplasty of the MTP joint, hemiarthroplasty, silicone implant.

Quality of Life in Patients With Untreated and Symptomatic Hallux Valgus

BACKGROUND

The purposes of this study were to compare the quality of life (QOL) of subjects who had untreated symptomatic hallux valgus with the QOL of the general population and to investigate factors associated with the QOL of the subjects.

METHODS

One hundred sixteen subjects with previously untreated and symptomatic hallux valgus were surveyed. QOL was assessed using the 36-item Short Form Health Survey (SF-36). Additionally, clinical evaluations (the visual analog scale for pain, Japanese Society for Surgery of the Foot Scale, lesser toe pain, and pain in other parts of the body) and radiographic evaluations (hallux valgus angle, intermetatarsal angle between the first and second metatarsals, and dislocation of the second metatarsophalangeal joint) were performed. Differences in the SF-36 between the subjects and the general population were tested using independent t tests. Correlations between the QOL measurements, clinical evaluations, and radiographic evaluations were assessed using Spearman rank correlation coefficient.

RESULTS

All SF-36 subscales and physical component summary scores for the subjects were significantly lower than those of the general population. Notably, the standardized physical function subscale (38.2 ± 15.8, P < .001) and physical component summary scores (38.9 ± 14.5, P < .001) were more than 10 points lower than those of the general population. Most QOL and clinical evaluation parameters were not correlated or were negligibly correlated with radiographic evaluations. Similarly, lesser toe pain or pain in other parts of the body was not correlated with QOL or clinical evaluations.

CONCLUSION

The QOL of untreated and symptomatic hallux valgus subjects was lower than that of the general population. All QOL and clinical evaluation parameters were not significantly or negligibly correlated with the severity of toe deformities. Surgical decision making should not be based on the severity of the deformity alone, but rather patient QOL should also be carefully assessed.

LEVEL OF EVIDENCE

Level III, comparative series.

Comparison of Hallux Interphalangeal Joint Arthrodesis Fixation Techniques: A Retrospective Multicenter Study

Few studies have investigated the complications that occur after hallux interphalangeal joint arthrodesis. The present study evaluated complications in 152 patients aged 18 to 80 years from 2005 to 2012 from 4 different academic institutions after hallux interphalangeal joint arthrodesis. Overall, 65.8% of the patients had ≥1 complication. Infections occurred in 16.5%, dehiscence in 12.5%, and reoperations in 27.0%. The clinical nonunion rate was ≥17.8%, and the radiographic nonunion rate was ≥13.8%. After logistic regression analysis, only the study site and peripheral neuropathy were associated with having ≥1 complication (p < .01 and p < .05, respectively). Single screw fixation compared with other fixation did not have a statistically significant influence on the postoperative complications. However, when fixation was expanded to 4 categories, single screw fixation had lower infection and reoperation rates than either crossed Kirschner wires or other fixation category but not compared with crossed screws on multivariate logistic regression analysis. Although additional studies are warranted, the findings from the present study might aid in both the prognosis of complications and the support of the use of a single screw over crossed Kirchner wire fixation in hallux interphalangeal joint arthrodesis.

A modified Austin/chevron osteotomy for treatment of hallux valgus and hallux rigidus

Abstract

The purpose of this brief paper is to present the preliminary results of a modified Austin/chevron osteotomy for treatment of hallux valgus and hallux rigidus. In this procedure, the dorsal arm of the osteotomy is performed orthogonal to the horizontal plane of the first metatarsal, the main advantage being that this allows much easier and more accurate multiplanar correction of first metatarsal deformities. From 2010 to 2013, 184 consecutive patients with symptomatic hallux valgus and 48 patients with hallux rigidus without severe metatarsophalangeal joint degeneration underwent such modified chevron osteotomy. Mean patient age was 54.9 (range 21–70) years, and mean follow-up duration was 41.7 (range 24–56) months. Ninety-three percent of patients were satisfied with the surgery. Mean American Orthopaedic Foot and Ankle Society (AOFAS) score improved from 56.6 preoperatively to 90.6 at last follow-up, and mean visual analog scale (VAS) pain score decreased from 5.7 preoperatively to 1.6 at final follow-up (p < 0.05). In patients treated for hallux valgus, mean hallux valgus angle decreased from 34.1° preoperatively to 6.2° at final follow-up, and mean intermetatarsal angle decreased from 18.5° preoperatively to 4.1° at final follow-up (p < 0.05). One patient developed postoperative transfer metatarsalgia, treated successfully with second-time percutaneous osteotomy of the minor metatarsals, whilst one patient had wound infection that resolved with systemic antibiotics.

Level of evidence

Level IV.

Destructive pseudo-neuroarthropathy associated with calcium pyrophosphate deposition

BACKGROUND

Calcium pyrophosphate deposition (CPPD) disease is a metabolic disorder characterized by soft tissue calcific deposits formed primarily in articular cartilage. What can result is a crystal-induced arthropathy often referred to as pseudogout, which is variable in both presentation and severity. A particularly destructive and deforming arthritis is an uncommon but well-recognized subtype of this disease. Radiologically resembling the neuroarthropathy described by Charcot, a pattern of joint fragmentation and structural collapse occurs in the absence of peripheral neuropathy. This pseudo-neuroarthropathy is rarely reported in the foot and ankle.

METHODS

A total of 15 cases of pseudo-neuroarthropathy involving some previously unreported joints within the foot and ankle are described in this case series of 9 patients.

RESULTS

All patients presented with disease involving multiple joints. Clinical deformity was apparent in each case, and extensive joint destruction was seen on plain radiographs. In 6 patients, histopathological CPPD disease was confirmed on tissue biopsy of the affected joints. In the remaining 3 patients a clinical diagnosis was made on the basis of the classic appearance of pseudo-neuroarthropathy in the foot, with additional recognized features of CPPD. Operative management with deformity correction using joint arthrodesis produced satisfactory clinical and radiological results.

CONCLUSIONS

In the absence of peripheral neuropathy and systemic disease, the pseudo-neuroarthropathy of CPPD should be considered when a progressively deforming and destructive arthritis is seen in the foot and ankle.

LEVEL OF EVIDENCE

Level IV, case series.

[The design of plantar pressure distribution monitoring system and preliminary clinical application]

Plantar pressure distribution can reflect the force of several key points on foot while standing and walking. A comprehensive understanding of the plantar pressure distribution makes great sense in the following aspects: the understanding of the normal foot biomechanics and function, clinical diagnosis, measurement of disease extent, postoperative efficacy evaluation, and rehabilitation research. A simple plantar pressure measurement device was designed in this study. This paper uses FlexiForce flexible sensor to pickup plantar pressure signal and USB A/D board to do data acquisition. The data are transferred into a laptop and processed by a VB-based software which can display, remember and replay the data. We chose patients with hallux valgus and normal people to measure the pressure distribution and make contrast analysis of plantar pressure with this device. It can be concluded that people with hallux valgus have higher pressure on the second metatarsophalangeal joint and the distribution move outward. The plantar pressure of patients postoperative could be greatly improved compared to the preoperative. The function of this device has been confirmed.

Arthritides of the foot

Arthritis of the foot can be a difficult problem. It is initially managed with antiinflammatory medications and footwear modifications or bracing. However, a significant percentage of people with arthritis of the foot go on to require surgical intervention, which is most commonly arthrodesis.

Hallux valgus

Hallux valgus is a common foot problem whose cause and progression is multifactorial, complex, and poorly known. Hallux valgus shows a predilection toward women. It is a progressive disorder with no treatment known to slow or stop progression. Surgery is indicated in healthy individuals when nonoperative measures fail. Adverse effects of surgery include infection and recurrence. Many procedures have been described, including soft tissue and bony reconstruction of the first ray. The procedure that is indicated depends on the severity of the deformity.

Metatarsalgia, lesser toe deformities, and associated disorders of the forefoot

Forefoot pain in the adult often alters mobility and has a negative impact on quality of life. Metatarsalgia describes pain localized to the forefoot. Forefoot pain may be caused by conditions of the lesser toes themselves (eg, hammertoes, mallet toes, claw toes). The pathophysiology of lesser toe deformities is complex and is affected by the function of intrinsic and extrinsic muscle units. In addition to lesser toe and metatarsal abnormality, forefoot pain can be attributed to interdigital neuritis, disorders of the plantar skin, and gastrocsoleus contracture. Treatment of these conditions may include shoe modifications, appliances, therapeutic exercises, and surgical repair.

The biomechanics of the first metatarsal bone in hallux valgus: a preliminary study utilizing a weight bearing extremity CT

BACKGROUND

Hallux valgus is a common but aetiologically not perfectly understood condition. Imaging in hallux valgus is based on weight bearing plain radiographs or in exceptional cases on non-weight bearing computerized tomography (CT)-studies.

METHODS

A portable extremity CT was used to study the forefoot with focus on first metatarsal bone in ten hallux valgus patients and five asymptomatic controls at rest and at weight bearing. Two-dimensional (2D) or three-dimensional (3D) hallux valgus angles, intermetatarsal angles and various other parameters were measured on CT data and the measurements between study groups were compared. The measured angles were also compared to angles measured on plain radiographs.

RESULTS

2D or 3D angles from CT data sets can be used to evaluate hallux valgus. In hallux valgus, when compared with normal asymptomatic foot, the first metatarsal bone is medially deviated (intermetatarsal angle is wider), the width of the forefoot is increased and the proximal phalanx pronates. Between the study groups there was a statistically significant difference of the measured 3D hallux valgus angles at weight bearing but not at rest suggesting the importance of weight bearing CT studies when evaluating hallux valgus.

CONCLUSIONS

To our knowledge, this is the first time weight bearing CT data is presented when evaluating hallux valgus, offering a true alternative to plain radiographs. The relationships of bones of the forefoot, including rotational changes, can be reliably measured using this imaging method.

First metatarsophalangeal joint replacement with modular three-component press-fit implant. Preliminary report

PURPOSE OF THE STUDY

The aim of this retrospective study was to assess functional and radiographic results of the first metatarsophalangeal joint replacement with use of unconstrained, modular, three components, porous titanium and hydroxyapatite coated, press-fit METIS® prosthesis. According to author's knowledge, results of that type of prosthesis have never been published before.

MATERIAL AND METHODS

25 prosthesis were implanted in 24 patients between February 2009 and May 2011. American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal scoring system (AOFAS-HMI) was used to assess functional results. Patients were also asked if they would undergo procedure again or recommend it to other people. Weight bearing radiographs ware made at final follow up and analyzed for presence of osteolysis and radiolucencies. In 8 patients total joint replacement was introduced as a salvage after failure of previous surgery like Keller resection arthroplasty, failed arthrodesis, avascular necrosis and postoperative arthritis. In 11 patients the reason for prosthetic replacement were hallux rigidus, in 4 cases rheumatoid arthritis and gout in one patient. In two patients additional procedures like Akin phalangeal osteotomy and in one case fifth metatarsal osteotomy, was performed. There were 20 females and 4 males in presented group. The mean age at the operation was 56 years. The average follow up period was 18 months (from 12 to 36 months).

RESULTS

The median postoperative value of AOFAS-HMI scores was 88 points (from 75 to 95 points). First metatarsophalangeal joint motion (dorsiflexion plus plantarflexion) was classified according to AOFAS-HMI ranges as: moderately restricted (between 30 to 70 degrees) in 19 patients 80% (20 prosthesis) and severely restricted (less then 30 degrees) in 5 patients (20%). 15 (64%) patients were completely satisfied, 5 (20%) reported moderate satisfaction and (16%) 4 were totally disappointed and would not undergo this procedure again. A limited hallux dorsiflexion was the main dissatisfaction reason. Partial radiolucent line was seen in one patient (4%). Authors noticed two serious complications. In one patient, with rheumatoid arthritis, deep infection occurred 12 months after prosthesis implantation. In second case phalangeal implant was revised due to misalignment.

CONCLUSIONS

METIS® metatarsophalangeal joint replacement allows alleviate of pain relating to hallux rigidus and partial restoration of joint movement, even in patients after failures of primary metatarsophalangeal joint surgery. AOFAS-HMI results are better than previously reported in the literature in assessment of the first metatarsophalangeal joint replacement. Radiographic results imply satisfactory bone ingrowth into the cementless implants.

Pull-out technique for plantar plate repair of the metatarsophalangeal joint

Plantar plate rupture is a common cause of forefoot pain, multiplanar malalignment, subluxation, or dislocation of the metatarsophalangeal joint (MTPJ). The treatments that have been described for MTPJ instability of lesser toes include amputation, lengthening and/or tendon transfer, periarticular soft-tissue release (capsule, collateral ligaments, and plantar plate), colateral ligament reconstruction, metatarsal shortening osteotomy, and suture of plantar plate lesion. This article outlines the anatomy, pathogenesis, and diagnosis of plantar plate rupture, and describes a new technique that combines joint decompression by Weil osteotomy with a plantar plate repair using a pull-out technique.

Pressure pain thresholds at the diabetic Charcot-foot: an exploratory study

OBJECTIVE

Painless mechanical trauma is believed to induce neuroosteoarthropathy at the neuropathic foot in diabetes (diabetic Charcot-foot). To investigate pressure nociception at the diabetic foot, we measured the pain perception thresholds for deep pressure (DPPPT, using Algometer II®) and cutaneous pressure (CPPPT, using calibrated monofilaments).

METHODS

In 24 diabetic patients with painless neuropathy (11 with a chronic, inactive Charcot-foot and a history of foot ulcer, and 13 control patients who never had an ulcer), and in 20 healthy subjects, CPPPT (at palmar and plantar digital skinfolds) and DPPPT (over musculus abductor pollicis, musculus hallucis longus, and over metacarpophalangeal and metatarsophalangeal joints) was measured.

RESULTS

At the hands, DPPPT and CPPPT were similar in patients and healthy subjects. At the feet, CPPPT was above the upper safety limit of measurement (512 mN) in 2/20 healthy subjects, and in 11/11 Charcot patients compared to 6/13 neuropathic controls (p=0.005). At the feet, median DPPPT was similar in all groups. In Charcot patients only, DPPPT was higher over metatarsophalangeal joint than over m. hallucis longus (p=0.048).

CONCLUSION

Perception thresholds for cutaneous pressure pain, but not for deep pressure pain, may be extremely elevated at the diabetic neuropathic foot, and particularly at the Charcot-foot.

Etiology and biomechanics of first metatarsophalangeal joint sprains (turf toe) in athletes

Sprains of the first metatarsophalangeal (MTP) joint, referred to colloquially as "turf toe," are a debilitating sports injury because the hallux is pivotal to an athletes' ability to accelerate and cut. Severe sprains may require weeks to full recovery, and injuries requiring surgery may prevent an athlete from full athletic participation for months. Whereas the diagnosis and treatment of turf toe are well documented in the literature, less is known about the biomechanics of this joint and the mechanical properties of the structures that compose it. Nevertheless, this information is vital to those, such as equipment designers, who attempt to develop athletic footwear and surfaces intended to reduce the likelihood of injury. To that end, this review summarizes the literature on the anatomy of the first MTP joint, on biomechanical studies of the first MTP joint, and on the incidence, mechanisms, and treatment of turf toe. Furthermore, gaps in the literature are identified and opportunities for future research are discussed. Only through a thorough synthesis of the anatomic, biomechanical, and clinical knowledge regarding first MTP joint sprains can appropriate countermeasures be designed to reduce the prevalence and severity of these injuries.

Prevalence of hallux valgus among youth population in Lagos, Nigeria

AIMS AND OBJECTIVE

This study was aimed at evaluating the prevalence of Hallux Valgus (HV) and related foot problems among the youth population in Lagos, Nigeria.

SUBJECTS AND METHODS

A structured questionnaire was administered to 1, 200 subjects from 10 secondary schools and undergraduate students of the College of Medicine University of Lagos, Lagos, Nigeria. The participants were requested to provide information on demographic data, severity of HV, and the functional limitation imposed on the participants by HV. Nine hundred and seventy (970) of the 979 returned questionnaires were analyzed using descriptive statistics.

RESULTS

The prevalence of HV in this study was 15.4% of which 43.6% and 56.4% were male and female respectively. 36 (3.7%) out of total number of participants had bilateral HV (both feet), 57 (5.9%) and 56 (5.8%) had HV on left and right foot only respectively. Eighty four (25.2%) of the 333 (34.3%) subjects that complained of pain at the first metatarsophalangeal joint had HV. Inability to stand for long periods due to pain at the first metatarsophalangeal joint was reported by 90 (9.3%) participants, while 136 (14.0%) reported inability to walk long distances.

CONCLUSION

Prevalence of HV among youths in Lagos, Nigeria is low. HV is more common among females and its prevalence increases with age. More attention should be focused on foot pain and deformities. Preventive measures and education on the HV deformity is advocated.

The translating Weil osteotomy in the treatment of an overriding second toe: a report of 25 cases

We present a retrospective study of 25 feet operated for an overriding second toe deformity, whether or not associated with hallux valgus deformity and metatarsalgia. The surgical technique of a medial sliding and decompressive Weil osteotomy is described. All patients, operated between January 2002 and December 2007 for this condition in our institution, were reviewed clinically and radiologically. The mean AOFAS score improved with 47.6 points from 45.9 to 93.5. The theoretical advantages of such a translation Weil osteotomy are discussed trying to clarify the previously described pathologic anatomy of this condition.

Mid-term results of Scarf osteotomy in hallux valgus

We performed a retrospective study on 178 Scarf osteotomies with a mean follow-up of 44.9 months (range 15-83 months). Clinical rating was based on the forefoot score of the American Orthopaedic Foot and Ankle Society (AOFAS). Weight bearing X-rays were used to perform angular measurements and assess the first metatarsophalangeal joint (MTP 1). At follow-up the mean AOFAS score had improved significantly (p < 0.001), but only 55% of the feet showed a perfect realignment of the first ray. Patients with a hallux valgus angle exceeding 30° and pre-existing degenerative changes at the MTP 1 joint displayed inferior clinical results (p < 0.05). Nearly 20% of the patients suffered from pain at the MTP 1 joint. This was clearly attributed to an onset or worsening of distinct radiographic signs of arthritis (p < 0.05) resulting in painfully decreased joint motion. Comparing radiographic appearance three months postoperatively and at follow-up, we found that radiographic criteria (hallux valgus, first intermetatarsal angle, hallux valgus interphalangeus, MTP 1 joint congruency, arthritic lesions at MTP 1) worsened with time.

Rheumatoid forefoot reconstruction

Management of the patient with rheumatoid forefoot deformity requires a multidisciplinary integrated approach for a successful outcome. Despite recent advances in the pharmacological management of rheumatoid arthritis and its impact upon disease progression, forefoot deformity and pain remain common manifestations requiring input from orthopaedic surgeons. The typical deformities encountered include hallux valgus, with subluxation or frank dislocation at the lesser metatarsophalangeal (MTP) joints. Surgical intervention is directed at correcting and decompressing these deformities, with the ultimate goal of a stable, painless, functional plantigrade foot. Although a variety of surgical options exist, fusion of the 1st MTP joint with lesser MTP joint excision arthroplasty remains the gold standard, upon which newer procedures should be judged. This article reviews the pathophysiology of forefoot deformity in rheumatoid arthritis with special emphasis on recent advances in surgical management.

Use of a combined pedicled toe fillet flap

We report the use of a double toe fillet flap combined with reconstruction of the joint capsule of the metatarsal proximal phalanx (MP) in a diabetic patient with a chronic persistent deep plantar ulcer and an avulsed third MP joint. Not only was the soft tissue defect dealt with, but also the stability of the MP joint was increased by the vascularised extensor tendon provided by the pedicled toe fillet flap.

Correction of hallux valgus deformity using the center of rotation of angulation method

BACKGROUND

To correct a hallux valgus (HV) deformity quantitatively and prevent unexpected postoperative deformity, the center of rotation of angulation (CORA) method was applied during HV surgery. To correct a hallux valgus (HV) deformity quantitatively and prevent unexpected postoperative deformity, the center of rotation of angulation (CORA) method was applied during HV surgery.

METHODS

To create a normal foot model, radiographs of 64 normal female feet were measured. Points A and B were defined as the intersection of the intermetatarsal angle and the HV angle. CORA1 and CORA2 were defined as the intersection of the axes of the first metatarsal and the first proximal phalanx in the normal and HV models, respectively. Procedures to correct HV deformity using the CORA method were devised and were applied to HV feet, which underwent a focal dome osteotomy or medial wedge osteotomy.

RESULTS

Point A was 2.3 times the length of the second metatarsal proximally from the top of the second metatarsal head, and point B was 0.17 times the length of the first metatarsal proximally from the top of the first metatarsal head. Two methods were used to correct the deformity. With one method, a focal dome osteotomy was performed at the first metatarsal on the circle at the CORA1 and the distal fragment was moved to the standard first metatarsal axis. The first proximal phalanx was then moved around the metatarsal head to the standard axis of the first proximal phalanx at the CORA2. With the other method, a medial wedge osteotomy was performed on or proximal to the CORA2, and the distal fragment was moved to the first standard metatarsal axis.

CONCLUSIONS

We propose a preoperative plan to use the CORA method to correct deformities that prevent translation of the axis or an angulation deformity. HV deformity can be corrected effectively using the CORA method.

An evaluation of the long-term effects of total plantar fasciotomy--a preliminary study

BACKGROUND

Plantar fascia release for chronic plantar fasciitis has given excellent pain relief and rapid return to activities with few reported complications. Cadaveric studies have led to the identification of some potential post-operative problems, commonly weakness of the medial longitudinal arch (MLA) and pain in the lateral midfoot.

METHODS

Eight total plantar fasciotomy patients (five bilateral and three unilateral) were evaluated subjectively and objectively with regards to surgical outcome and biomechanical change. The centre of pressure (COP) and loading of the foot were measured using the F Scan mobile system and COM'nalysis software. In addition, five control subjects were evaluated with the F Scan. The reading for one foot of one of the control subjects was discarded due to a biomechanical abnormality.

RESULTS

The results of this study were that the COP of the foot in post-total plantar fasciotomy subjects was significantly laterally deviated throughout the propulsive phase of gait compared to that of control subjects (p<0.05). There was no significant difference in plantar pressure at the rearfoot or the first metatarsophangeal joint (MTPJt) between the post-operative and control groups (p>0.05). Six of the eight of the post-operative patients (11 feet) considered the procedure to be successful in resolving their symptoms.

CONCLUSION

Total plantar fasciotomy may result in changes to the COP of the foot. It could be extrapolated from this data, in conjunction with subjective visual clinical observations of gait, that supination of the foot could occur post-operatively rather than the pronatory state secondary to a collapsed arch that, collectively, the results of cadaver studies have suggested. The conclusions drawn from this pilot study are to some extent speculative, as the measurements were only made post-operatively and a small number of subjects were studied. Further research is required in this area.

Limited joint mobility and plantar pressure in type 1 diabetic subjects in India

AIM

Limited joint mobility and plantar pressure in the foot has not been assessed in type 1 diabetes. The aim of this study was to investigate the joint mobility and plantar foot pressure in Asian Indian type 1 diabetic subjects and to see its association with duration of diabetes.

MATERIAL AND METHODS

The joint mobility and plantar pressure were measured in 115 consecutive subjects attending the foot clinic. The study groups were: Control- non diabetic controls (n=40) (M:F 19:21) and type 1 diabetic patients (n=75) (M:F 42:33). Joint mobility was assessed using a goniometer at two sites, in the subtalar joint and in the hallux. Plantar pressure was measured using the RS-Scan platform system. Data obtained on the metatarsal heads were used for analysis.

RESULTS

Patients with type 1 diabetes had significantly lesser joint mobility (p < 0.0001) and higher plantar pressure (p < 0.0001) compared with the control group. Duration of diabetes had an inverse association with joint mobility (p < 0.0001). The degree of joint mobility was more restricted in patients with longer duration of diabetes. Plantar pressure increased with increasing duration of diabetes.

CONCLUSION

In conclusion, type 1 diabetic patients in India had limited joint mobility which decreased further with longer duration of diabetes and they had high plantar pressure also.

Reconstruction of Metacarpophalangeal Joint by Free Vascularized Autogenous Metatarsophalangeal Joint Transplant

Six cases of autotransplantation of free vascularized second metatarsophalangeal joint to reconstruct damaged metacarpophalangeal (MP) joints are reported. Anatomical studies in cadaver and clinical cases involving the origin, course, and importance of preserving the articular branch of the metatarsal artery are described. Follow-up of cases from six months to 21/2 years postoperative reveal recovery of thumb function, stability of the transplanted joint, and no obvious degenerative changes.

[Complications of first ray osteotomies: a consecutive series of 475 feet with first metatarsal Scarf osteotomy and first phalanx osteotomy]

PURPOSE OF THE STUDY

Available studies on Scarf osteotomies of the first metatarsal (M1) and first phalange (P1) shortening and varus displacement have reported good results, but have have not focused on complications. We reviewed a consecutive series of 475 feet operated on over a five year period. Our goal was to determine the incidence of complications and to compare our data with reports in the literature. We wanted to know if association with Weil osteotomy on the lateral metatarsals affects the rate of complications.

MATERIAL AND METHODS

We used the following inclusion criteria: hallux valgus>35 degrees, adult subject, with or without impact on the lateral ray, no prior foot surgery, no systemic disease, no other co-morbid condition. We distinguished two groups: group 1 with isolated first ray disease, and group 2 with hallux valgus and lateral metatarsalgia requiring surgery.

RESULTS

We determined the incidence of each complication. Metatarso-phalangeal joint (MTP1) stiffness was the most frequent complication: incidence declined with postoperative time: 41.7% at day 35, 5.7% at day 120. The joint was very stiff with defective pulp weight-bearing in 1.3% of the feet at 12 months. Late wound healing was observed in 5.7% of feet and secondary osteotomy displacement in 1%. Incidence of other complications, including operative site infection, was less than 1%. General complications were: reflex dystrophy (1.3%) and deep vein thrombosis (0.6%). Excepting a longer period of postoperative stiffness, we were unable to identify any change in the rate of postoperative complications in feet with an associated Weil osteotomy of the first ray.

DISCUSSION

Our findings confirm that Scarf M1 osteotomies with varus shortening of P1 generates fewer complications than the techniques used earlier. Certain complications have disappeared: nonunion after M1 and P1 osteotomy, great toe claw, symptomatic iatrogenic hallux valgus. Complications with a very low incidence in all series are: operative site infection, osteonecrosis of the M1 head, fracture of M1 at weight bearing. Notching of the two osteotomy pieces with elevation of the metatarsal head and transfer metatarsalgia has been reported by authors using short diaphyseal osteotomies. A stiff MTP1 remains the most frequent complication. Overtly stiff joints (30% loss of range of motion) were observed in 4.6% of our patients at 12 months; 1.3% had major stiffness (20 degrees extension, 0 degrees plantar flexion). This stiffness has been reported by others using the same technique but the risk factors have not been identified.

CONCLUSION

This prospective work enabled us to establish the rate of secondary complications of first ray surgery for M1 Scarf osteo-tomy and P1 osteotomy. Complications are rare, a further argument favoring use of these osteotomies. This statistical study enables us discuss the risk of complications at the preoperative interview, keeping in mind the specific elements inherent in each particular situation.

Hallux valgus and first ray mobility. A prospective study

BACKGROUND

There have been few prospective studies that have documented the outcome of surgical treatment of hallux valgus deformities. The purpose of this investigation was to evaluate the effect of operative treatment of hallux valgus with use of a proximal crescentic osteotomy and distal soft-tissue repair on the first metatarsophalangeal joint.

METHODS

All adult patients in whom moderate or severe subluxated hallux valgus deformities had been treated with surgical repair between September 1999 and May 2002 were initially enrolled in the study. Those who had a hallux valgus deformity treated with a proximal crescentic osteotomy and distal soft-tissue reconstruction (and optional Akin phalangeal osteotomy) were then invited to return for a follow-up evaluation at a minimum of two years after surgery. Outcomes were assessed by a comparison of preoperative and postoperative pain and American Orthopaedic Foot and Ankle Society scores; objective measurements included ankle range of motion, Harris mat imprints, mobility of the first ray (assessed with use of a validated calibrated device), and radiographic angular measurements.

RESULTS

Of the 108 patients (127 feet), five patients (five feet) were unavailable for follow-up, leaving 103 patients (122 feet) with a diagnosis of moderate or severe primary hallux valgus who returned for the final evaluation. The mean duration of follow-up after the surgical repair was twenty-seven months. The mean pain score improved from 6.5 points preoperatively to 1.1 points following surgery. The mean American Orthopaedic Foot and Ankle Society score improved from 57 points preoperatively to 91 points postoperatively. One hundred and fourteen feet (93%) were rated as having good or excellent results following surgery. Twenty-three feet demonstrated increased mobility of the first ray prior to surgery, and only two feet did so following the bunion surgery. The mean hallux valgus angle diminished from 30 degrees preoperatively to 10 degrees postoperatively, and the mean first-second intermetatarsal angle decreased from 14.5 degrees preoperatively to 5.4 degrees postoperatively. Plantar gapping at the first metatarsocuneiform joint was observed in the preoperative weight-bearing lateral radiographs of twenty-eight (23%) of 122 feet, and it had resolved in one-third (nine) of them after hallux valgus correction. Complications included recurrence in six feet. First ray mobility was not associated with plantar gapping. There was a correlation between preoperative mobility of the first ray and the preoperative hallux valgus (r = 0.178) and the first-second intermetatarsal angles (r = 0.181). No correlation was detected between restricted ankle dorsiflexion and the magnitude of the preoperative hallux valgus deformity, the post-operative hallux valgus deformity, or the magnitude of hallux valgus correction.

CONCLUSIONS

A proximal crescentic osteotomy of the first metatarsal combined with distal soft-tissue realignment should be considered in the surgical management of moderate and severe subluxated hallux valgus deformities. First ray mobility was routinely reduced to a normal level without the need for an arthrodesis of the metatarsocuneiform joint. Plantar gapping is not a reliable radiographic indication of hypermobility of the first ray in the sagittal plane.

Finite Element Modeling of the First Ray of the Foot: A Tool for the Design of Interventions

Disorders of the first ray of the foot (defined as the hard and soft tissues of the first metatarsal, the sesamoids, and the phalanges of the great toe) are common, and therapeutic interventions to address these problems range from alterations in footwear to orthopedic surgery. Experimental verification of these procedures is often lacking, and thus, a computational modeling approach could provide a means to explore different interventional strategies. A three-dimensional finite element model of the first ray was developed for this purpose. A hexahedral mesh was constructed from magnetic resonance images of the right foot of a male subject. The soft tissue was assumed to be incompressible and hyperelastic, and the bones were modeled as rigid. Contact with friction between the foot and the floor or footwear was defined, and forces were applied to the base of the first metatarsal. Vertical force was extracted from experimental data, and a posterior force of 0.18 times the vertical force was assumed to represent loading at peak forefoot force in the late-stance phase of walking. The orientation of the model and joint configuration at that instant were obtained by minimizing the difference between model predicted and experimentally measured barefoot plantar pressures. The model were then oriented in a series of postures representative of push-off, and forces and joint moments were decreased to zero simultaneously. The pressure distribution underneath the first ray was obtained for each posture to illustrate changes under three case studies representing hallux limitus, surgical arthrodesis of the first ray, and a footwear intervention. Hallux limitus simulations showed that restriction of metatarsophalangeal joint dorsiflexion was directly related to increase and early occurrence of hallux pressures with severe immobility increasing the hallux pressures by as much as 223%. Modeling arthrodesis illustrated elevated hallux pressures when compared to barefoot and was dependent on fixation angles. One degree change in dorsiflexion and valgus fixation angles introduced approximate changes in peak hallux pressure by 95 and 22 kPa, respectively. Footwear simulations using flat insoles showed that using the given set of materials, reductions of at least 18% and 43% under metatarsal head and hallux, respectively, were possible.

Prospective gait analysis in patients with first metatarsophalangeal joint arthrodesis for hallux rigidus

BACKGROUND

Arthrodesis of the first metatarsophalangeal (MTP) joint is a common procedure with a proven long-term success rate. However, there is limited scientific information on its functional results. There is little data in the literature about changes in gait parameters after first MTP joint arthrodesis. The purpose of this study was to objectively evaluate the effects of first MTP joint arthrodesis on gait.

METHODS

Twenty-three patients with symptomatic hallux rigidus refractory to nonoperative treatment were treated with first MTP joint arthrodesis. A prospective gait analysis study was performed on all patients at an average of 8.6 days before surgery and then again at least 1 year postoperatively. Preoperative and postoperative data from the patients were compared to determine differences in clinically relevant temporal-spatial, kinematic, and kinetic parameters of gait.

RESULTS

There were three statistically significant changes in gait: increases in maximal ankle push-off power and single-limb support time on the involved extremity, and a decrease in step width.

CONCLUSIONS

First MTP joint arthrodesis produces objective improvement in propulsive power, weightbearing function of the foot, and stability during gait.

Effect of functional foot orthoses on first metatarsophalangeal joint dorsiflexion in stance and gait

Reduction in first metatarsophalangeal joint maximum degree of dorsiflexion with dorsiflexion of the first ray has been proposed to be the predominant cause of hallux abducto valgus and hallux rigidus. We sought to determine whether orthoses made from a cast with the first ray plantarflexed and a 4-mm medial skive could increase the maximum degree of dorsiflexion in patients with functional hallux limitus in stance and gait. Forty-eight feet of 27 subjects were casted for orthoses with the first ray plantarflexed and in the customary neutral rearfoot position with locked midtarsal joint. First metatarsophalangeal joint maximum dorsiflexion was measured with and without orthoses in stance, and subhallux pressure was measured with and without orthoses at heel-off. Changes in mean maximum dorsiflexion in stance and in mean maximum subhallux pressure in gait with orthoses were significant. We investigated the relationship between this increase in dorsiflexion and gender, shoe size, resting calcaneal stance position, and change in resting calcaneal stance position with the use of orthoses. These correlations were not statistically significant. The biomechanical implication of increasing limited first metatarsophalangeal joint dorsiflexion with orthoses is discussed and related to the clinical treatment of deformities, including hallux valgus and hallux rigidus. The use of orthoses to decrease subhallux pressure is also discussed.

Effects of hallux limitus on plantar foot pressure and foot kinematics during walking

The effects of hallux limitus on plantar foot pressure and foot kinematics have received limited attention in the literature. Therefore, a study was conducted to assess the effects of limited first metatarsophalangeal joint mobility on plantar foot pressure. It was equally important to identify detection criteria based on plantar pressures and metatarsophalangeal joint kinematics, enabling differentiation between subjects affected by hallux limitus and people with normal hallux function. To further our understanding of the relation between midtarsal collapse and hallux limitus, kinematic variables relating to midtarsal pronation were also included in the study. Two populations of 19 subjects each, one with hallux limitus and the other free of functional abnormalities, were asked to walk at their preferred speed while plantar foot pressures were recorded along with three-dimensional foot kinematics. The presence of hallux limitus, structural or functional, caused peak plantar pressure under the hallux to build up significantly more and at a faster rate than under the first metatarsal head. Additional discriminators for hallux limitus were peak dorsiflexion of the first metatarsophalangeal joint, time to this peak value, peak pressure ratios of the first metatarsal head and the more lateral metatarsal heads, and time to maximal pressure under the fourth and fifth metatarsal heads. Finally, in approximately 20% of the subjects, with and without hallux limitus, midtarsal pronation occurred after heel lift, validating the claim that retrograde midtarsal pronation does occur.

Effects of rearfoot-controlling orthotic treatment on dorsiflexion of the hallux in feet with abnormal subtalar pronation: a preliminary report

The aim of this study was to determine whether the treatment of abnormal subtalar pronation restores functional (as opposed to structural) limited dorsiflexion of the first metatarsophalangeal joint (functional hallux limitus). We studied 16 feet of eight individuals with abnormal subtalar pronation. Orthoses were made for all of the feet, and hallux dorsiflexion was measured during weightbearing. Each patient was unshod without the orthosis, unshod with the orthosis fitted on the same day, and unshod with the orthosis fitted approximately 5 months later. The results suggest that in functional hallux limitus caused by abnormal subtalar pronation, hallux dorsiflexion will gradually be restored by the use of foot orthoses to control the abnormal subtalar pronation.

Arthrodesis versus Mayo resection

In a prospective randomised study 31 patients were allocated to either arthrodesis or Mayo resection of the first metatarsophalangeal joint as part of a total reconstruction of the rheumatoid forefoot. Of these, 29 were re-examined after a mean of 72 months (57 to 80), the Foot Function Index was scored and any deformity measured. Load distribution was analysed using a Fscan mat in 14 cases, and time and distance were measured in 12 of these patients using a 3D Motion system. We found excellent patient satisfaction and a significant, lasting reduction of the Foot Function Index, with no statistically significant differences between the groups. There were no significant differences in recurrence of the deformity, the need for special shoes, gait velocity, step length, plantar moment, mean pressure or the position of the centre of force under the forefoot. The cadence was higher and the stance phase shorter in the fusion group.

These results suggest that a Mayo resection may be an equally good option for managing the first metatarsophalangeal joint in reconstruction of the rheumatoid forefoot.

Effect of foot posture and inverted foot orthoses on hallux dorsiflexion

A pronated foot posture is considered to be a factor in limitation of dorsiflexion at the first metatarsophalangeal joint during weightbearing. Customized foot orthoses are widely used to increase dorsiflexion at the first metatarsophalangeal joint in people with pronated feet. However, the effect of foot posture and customized foot orthoses on maximum first metatarsophalangeal joint dorsiflexion has not been widely investigated. This study sought to determine 1) the relationship between foot posture and static maximum first metatarsophalangeal joint dorsiflexion and 2) the effect of customized foot orthoses on static maximum first metatarsophalangeal joint dorsiflexion in people with pronated feet. Foot posture was assessed using the Foot Posture Index. Static maximum first metatarsophalangeal joint dorsiflexion of the right foot was determined using a goniometer while participants stood relaxed with and without Blake-style inverted (30 degrees) foot orthoses positioned under their feet. There was a significant negative correlation between Foot Posture Index and static maximum first metatarsophalangeal joint dorsiflexion (r = -0.587). Inverted (30 degrees) foot orthoses increased the magnitude of static maximum first metatarsophalangeal joint dorsiflexion from 83.4 degrees to 85.3 degrees in participants with an excessively pronated foot posture. However, this difference was not statistically significant. People with pronated feet are more likely to exhibit limitation of dorsiflexion at the first metatarsophalangeal joint during gait, and inverted foot orthoses are unlikely to be effective in increasing dorsiflexion at the first metatarsophalangeal joint in these people.

Outcomes after interposition arthroplasty for treatment of hallux rigidus

Interposition arthroplasty reportedly improves outcomes after traditional salvage procedures for advanced hallux rigidus. We hypothesized this procedure can provide pain relief and satisfactory function with few complications. We examined 18 patients with severe articular cartilage loss who received 21 interposition arthroplasties. The patients a mean age was 56 years. They had a mean followup of 38 months. All patients had substantial loss of articular cartilage when examined intraoperatively. Patients were evaluated using the American Orthopaedic Foot and Ankle Society and Short Form-36 scores. All 18 patients had pain relief, and 17 of 18 patients said they would have the procedure again. The mean postoperative increase in range of motion of the first meta-tarsophalangeal joint was 37 degrees . The mean American Orthopaedic Foot and Ankle Society and Short Form-36 scores were 78.4 and 96.3, respectively. The complication rate was 6%. Results of our study indicate that interposition arthroplasty relieves pain and restores motion in patients with advanced hallux rigidus and may offer a reliable option to fusing the joint.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series).

Intrinsic risk factors for inversion ankle sprains in females--a prospective study

Ankle sprains are extremely common. However, very little is known about the variables that predispose individuals to these injuries. The purpose of this study was to examine prospectively intrinsic risk factors for inversion sprains in a young physically active female population. One hundred and fifty-nine female physical education students were evaluated for several possible intrinsic risk factors for inversion sprains at the beginning of their academic study. The evaluated intrinsic risk factors included anthropometrical and physical characteristics, ankle joint position sense, isokinetic ankle muscle strength, lower leg alignment characteristics, postural control and muscle reaction time during a sudden inversion perturbation. All sports injuries were registered during 1-3 years and exposure to sport was recorded (mean: 15.33+/-4.33 h a week). Thirty-two (20%) of the 159 females sprained their ankle. The number of ankle sprains per 1000 h of sports exposure was 0.75. The Cox regression analysis revealed that females with less accurate passive joint inversion position sense [hazard ratio (HR): 1.08, 95% confidence interval (CI): 1.02-1.14 for absolute error at 15 degrees inversion], a higher extension range of motion at the first metatarsophalangeal joint (HR: 1.03, 95% CI: 1.00-1.06) and less coordination of postural control (HR: 0.96, 95% CI: 0.93-1.00 for endpoint excursion; HR: 0.94, 95% CI: 0.89-0.99 for maximal endpoint excursion) are at greater risk of an ankle sprain. The findings of this study suggest that effective prevention and conservative rehabilitation of ankle inversion sprains should include attention to these variables.

The Influence of Two Different Types of Foot Orthoses on First Metatarsophalangeal Joint Kinematics During Gait in a Single Subject

OBJECTIVE

To quantify the effect of two distinct foot orthotic designs on in vivo multisegment foot and leg motion; in particular, the first metatarsal and first metatarsophalangeal (MTP) joint during gait.

METHODS

A 23-year-old man had an excessively pronated foot structure as measured during a clinical orthopedic examination. The Optotrak Motion Analysis System was used to collect three-dimensional position and orientation data from four modeled rigid body segments (hallux, first metatarsal, calcaneus, and tibia) during the stance phase of walking. The subject walked at a self-selected comfortable walking speed, and a minimum of five trials were collected under three different test conditions: no orthosis, semirigid orthosis with a varus post, and a semirigid orthosis with a varus post and a large medial flange. Data were normalized to the stance period, and descriptive statistics were calculated for dependent variables.

RESULTS

Both orthotic interventions equally modified first MTP joint motion when compared with the no orthotic condition. First MTP joint dorsiflexion was decreased (>2 SD) with the orthosis during terminal stance phase. This decrease was associated with a concomitant increase in first metatarsal plantar flexion.

CONCLUSION

A custom-made semirigid orthosis posted medially and made from a neutral position off-weight-bearing plaster cast can alter motion in the forefoot during the propulsive period by increasing first metatarsal plantar flexion and decreasing excessive first MTP joint dorsiflexion.