Recovery of the posterior tibial muscle after late reconstruction following tendon rupture

Histologic grading correlates with inflammatory biomarkers in tibialis posterior tendon dysfunction

BACKGROUND

It has been theorized that tibialis posterior tendon dysfunction (TPTD) is a degenerative process unrelated to inflammation. The purpose of this study was to determine if inflammatory cytokines, matrix metalloproteases (MMPs), and glutamate were elevated in diseased tibialis posterior tendons (TPTs).

METHODS

Matched diseased TPT, TPT insertion, and flexor digitorum longus (FDL) samples were collected from 21 patients. The samples were individually incubated in media, which was analyzed for inflammatory cytokines, MMPs, and glutamate. Histology and statistical analyses were performed.

RESULTS

Diseased TPT and TPT insertion were significantly elevated compared to transferred FDL in eight inflammatory markers (p < 0.005). Only the diseased TPT was significantly elevated compared to the transferred FDL tendons for glutamate (p < 0.01). Histologic grading correlated with inflammatory cytokine levels.

CONCLUSION

Diseased TPT and TPT insertion demonstrated significantly elevated levels of inflammatory markers compared to the transferred tendons used as controls, suggesting a role for inflammation in the disease process. The amount of inflammation correlated with increased tendon degradation.

LEVEL OF EVIDENCE

Level III.

Surgical Management of Musculotendinous Balance in the Progressive Collapsing Foot Deformity: The Role of Peroneal and Gastrocnemius Contracture

Surgical treatment of progressive collapsing foot deformity (PCFD) relies on understanding the dynamic and deforming musculotendinous structures that contribute to hindfoot valgus, forefoot abduction, forefoot varus, and collapse or hypermobility of the medial column. Equinus commonly is seen in PCFD and consideration should be given to isolated gastrocnemius or Achilles lengthening. Although transfer of the flexor digitorum longus tendon is performed in PCFD attributed to dysfunction and pathology of the posterior tibialis tendon (PTT), retention of PTT is an area for further research. The peroneus brevis, which contributes to hindfoot imbalance in chronic cases, is a possible component of tendon rebalancing.

Functional limitations after lateral column lengthening osteotomy of the calcaneus are associated with lower quality of life

PURPOSE

The purpose of this study was to quantify limitations in sagittal ankle range of motion (ROM) at least two years after lateral column lengthening osteotomy of the calcaneus (LLC) and their implications regarding quality of life.

METHODS

Fifteen patients with a mean follow-up of 80 ± 27 months after LLC and 15 age-matched healthy persons participated in this study. Ankle joint complex ROM in plantarflexion and dorsiflexion was measured bilaterally using a goniometer and fluoroscopy (patients only). Quality of life was assessed using the short-form health questionnaire (SF36). Differences in ROM parameters (for the tibiotalar and subtalar joint) between sides (affected vs. unaffected) and between groups (patient vs. controls) and the relationship between ROM parameters and quality of life scores were assessed.

RESULTS

ROM of the ankle joint complex on the affected side in patients was smaller than on the contralateral side (goniometer and fluoroscopy) and in healthy persons (goniometer; all P < .05). Among patients, SF36 total and pain scores, respectively, correlated with ROM of the subtalar joint (fluoroscopy; R = 0.379, P = 0.039 and R = 0.537, P = 0.001). Among patients and healthy persons, those with smaller dorsiflexion (goniometer) had lower quality of life scores.

CONCLUSIONS

The smaller sagittal ROM of the affected ankle joint complex compared with the contralateral foot and healthy controls was mainly explained by limitations in the tibiotalar joint. Because of its association with quality of life, ROM should be considered in the treatment and rehabilitation planning in patients who are candidates for LLC.

Surgical Management of Stage 2 Adult and Pediatric Acquired Flatfoot Without Tendon Transfer or Arthrodesis: A Retrospective Study

Posterior tibial tendon dysfunction (PTTD) is a common pathology of the foot and ankle. Numerous techniques are available to reconstruct the flatfoot. Fusions and tendon transfers are popular methods; however, a wide range of complications have been associated with these procedures. The objective of the present study was to demonstrate the outcomes of reconstructive surgery for flatfoot correction without tendon transfer or arthrodesis. We performed a retrospective study of 43 patients and 56 feet who had undergone flatfoot reconstructive surgery from November 2011 to June 2016, with a mean follow-up period of 60 weeks (range 12 to 60 months). Each patient demonstrated a stage 2 flatfoot deformity classified using the Johnson and Strom classification. Depending on the patient's deformity, the procedures consisted of different variations of gastrocnemius recession, medial displacement calcaneal osteotomy, Evans osteotomy, and Cotton osteotomy. Six different preoperative and postoperative angles were radiographically measured on each foot studied. In all cases, the differences in the preoperative versus postoperative measurements were statistically significant (p < .003). We believe the foot and ankle surgeon can correct flatfoot deformity with the use of extraarticular procedures and create a plantigrade functional foot without fusion or tendon transfer.

Passive engineering mechanism enhancement of a flexor digitorum longus tendon transfer procedure

Standard treatments of adult acquired flatfoot deformity (AAFD) fail to correct associated dysfunction of the posterior tibial tendon (PTT). This study aimed to determine if a novel passive engineering mechanism (PEM) enhanced flexor digitorum longus (FDL) tendon transfer procedure would better restore physiologic PTT function to improve AAFD gait parameters compared to standard treatment. We evaluated the kinetic, pedobarographic, and kinematic effects of a pulley-based PEM-enhancement system utilizing a cadaveric flatfoot model and robotic gait simulator. FDL tendon force, FDL tendon excursion, regional peak plantar pressures, center of pressure, and foot bone/joint motions were quantified. Throughout the stance phase of gait, PEM-enhancement significantly increased FDL tendon forces, resulting in gait cycle medial column unloading, lateral column loading, forefoot adduction, hindfoot inversion, and increased plantar flexion (p < 0.05). This proof-of-concept study demonstrated that an innovative PEM-enhanced FDL tendon transfer procedure better restored physiologic PTT function, resulting in improved correction of the distinctive AAFD gait characteristics-medial column collapse, hindfoot eversion, and forefoot abduction. Clinical significance: Novel PEM-enhancement of a FDL tendon transfer procedure holds promise as a method for improved treatment of AAFD. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3033-3042, 2018.

Posterior tibial tendon dysfunction: Clinical and magnetic resonance imaging findings having histology as reference standard

OBJECTIVE

To investigate the correlation between MRI, clinical tests, histopathologic features of posterior tibial tendon (PTT) dysfunction in patients with acquired adult flatfoot deformity surgically treated with medializing calcaneal osteotomy and flexor digitorum longus tendon transposition.

MATERIALS AND METHODS

Nineteen patients (11 females; age: 46 ± 15 year, range 18-75) were pre-operatively evaluated using the single heel rise (HR) and the first metatarsal rise (FMR) sign tests. Two reviewers graded the PTT tears on a I-III scale and measured the hindfoot valgus angle on the pre-operative MRI of the ankle. The specimens of the removed portion of PTT were histologically analysed by two pathologists using the Bonar and Movin score. Linear regression, Spearman's rank-order, and intraclass correlation coefficient (ICC) statistics were used.

RESULTS

ICC for MRI was excellent (0.952). Correlation between FMR and HR tests was at limit of significance (r = 0.454; P = 0.051). The HR and FMR tests were significantly correlated to the Movin score (r = 0.581; P = 0.009 and r = 0.538; P = 0.018, respectively) and were not significantly correlated to the Bonar score (both with a r = 0.424; P = 0.070). PTT tendinopathy grading at MRI was significantly correlated to the FMR test (p = 0.041) but not to the hindfoot valgus angle (p = 0.496), the HR test (p = 0.943), the Bonar score (p = 0.937), and the Movin score (p = 0.436). The hindfoot angle was not correlated to any of the other variables (p > 0.264).

CONCLUSION

For PTT dysfunction, there is high correlation between HR and FMR test and histology evaluated using the Movin score, while no correlation was seen for the Bonar score. Semiquantitative grading of PTT dysfunction at MRI only correlates to the FMR and not to histology. The hindfoot valgus angle is not correlated to any of the considered variables.

Reported selection criteria for adult acquired flatfoot deformity and posterior tibial tendon dysfunction: Are they one and the same? A systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) and adult acquired flatfoot deformity (AAFD) are used interchangeably, although both suggest quite different pathological processes.

OBJECTIVE

To investigate key differences in selection criteria used for inclusion into research studies.

METHODS

An electronic database search was performed from inception to June 2016. All primary research articles with clear inclusion/diagnostic criteria for PTTD or AAFD were included in the review. All criteria were extracted and synthesised into one aggregate list. Frequencies of recurring criteria were calculated and reported for each stage of the conditions.

RESULTS

Of the potentially eligible papers, 148 (65%) did not specify inclusion/selection criteria for PTTD or AAFD and were excluded. Eligibility criteria were reported 82 times in the 80 included papers, with 69 descriptions for PTTD and 13 for AAFD. After synthesis of criteria from all papers, there were 18 key signs and symptoms. Signs and symptoms were considered to be those relating to tendon pathology and those relating to structural deformity. The total number of individual inclusion/diagnostic criteria ranged from 2 to 9. The majority of articles required signs of both tendon dysfunction and structural deformity (84% for AAFD and 81% for PTTD). Across both groups, the most frequently reported criteria were abduction of the forefoot (11.5% of total criteria used), the presence of a flexible deformity (10.2%) and difficulty performing a single leg heel raise (10.0%). This was largely the case for the PTTD articles, whereas the AAFD articles were more focused on postural issues such as forefoot abduction, medial arch collapse, and hindfoot valgus (each 16.7%).

CONCLUSION

As well as synthesising the available literature and providing reporting recommendations, this review has identified that many papers investigating PTTD/AAFD do not state condition-specific selection criteria and that this limits their clinical applicability. Key signs and symptoms of PTTD and AAFD appear similar, except in early PTTD where no structural deformity is present. We recommend that PTTD is the preferred terminology for the condition associated with signs of local tendon dysfunction with pain and/or swelling along the tendon and difficulty with inversion and/or single leg heel raise characterising stage I and difficulty with single leg heel raise and a flexible flatfoot deformity characterizing stage II PTTD. While AAFD may be useful as an umbrella term for acquired flatfoot deformities, the specific associated aetiology should be reported in studies to aid consolidation and implementation of research into practice.

TRIAL REGISTRATION

Prospero ID: 42016046943.

[Degeneration of the posterior tibial tendon : Established and new concepts]

BACKGROUND

The most common cause of degeneration of the posterior tibial tendon is a congenital valgus deformity of the calcaneus. Other associated pathologies are forefoot supination, forefoot abduction and shortening of the gastrocnemius muscle.

DIAGNOSTICS

Loaded x‑rays of the foot in three planes as well as the hindfoot alignment view enable evaluation of the axis of the foot under static loading conditions. The posterior tibial tendon can be imaged with ultrasound and magnetic resonance imaging (MRI). The fatty degeneration of the posterior tibial muscle can be identified in MRI.

CONSERVATIVE THERAPY

Unloading of the posterior tibial tendon can be achieved by orthotics with medial support or braces.

SURGICAL THERAPY

The surgical therapy of the posterior tibial tendon alone has not been proven to be successful. The key element is the correction of the hindfoot valgus by medializing calcaneal osteotomy. Depending on the deformity, an additional lateral lengthening osteotomy of the calcaneus, as well as a dorsal open wedge osteotomy of the medial cuneiform bone (Cotton osteotomy) can additionally be indicated. The transposition of the tendon of the flexor digitorum longus muscle to the navicular bone is used to augment the posterior tibial tendon. Ruptures of the plantar calcaneonavicular ligament are sutured, in addition a sinus tarsi spacer can be implanted to protect medial soft tissues. A shortening of the gastrocnemius muscle is addressed by release of the aponeurosis. First results are published on use of biologically active substances, such as platelet rich plasma.

RESULTS

The correction of the hindfoot deformity as well as the subsequent treatment of the different components of the pathology lead to a significant improvement in foot function. Pre-existing degenerative alterations are limiting factors.

Addressing stage II posterior tibial tendon dysfunction: biomechanically repairing the osseous structures without the need of performing the flexor digitorum longus transfer

The clinical presentation of adult flatfoot can range from a flexible deformity with normal joint integrity to a rigid, arthritic flat foot. Debate still exists regarding the surgical management of stage II deformities, especially in the presence of medial column instability. This article reviews and discusses various surgical options for the correction of stage II flatfoot reconstructive procedures. The authors discuss their opinion that is not always necessary to transfer the flexor digitorum longus tendon to provide relief and stability in this patient population. The anatomy, diagnosis, and current treatments of flexible flatfoot deformity are discussed.

Surgical technique, fusion rates, and planovalgus foot deformity correction with naviculocuneiform fusion

BACKGROUND

Arthrodesis of the naviculocuneiform (NC) joints is not a common procedure, as it is perceived by many to be less reliable or less predictable than arthrodesis of proximal or distal joints in the medial column. There is a subset of patients with planovalgus feet, cavovarus feet, and degenerative arthritis who also have an apex of deformity at the NC joints in whom fusion is indicated. The surgical technique, fusion rates, and deformity correction data for NC fusion in planovalgus feet are evaluated in this report.

METHODS

Twenty-eight patients (33 feet) who underwent surgery between October 2008 and November 2012 were identified who had NC fusion as their only arthrodesis procedure. Medical records and radiographs were reviewed, and time to union was calculated. Twenty patients from that group underwent NC fusion for symptomatic planovalgus feet, and their preoperative and last postoperative weight-bearing radiographs were reviewed and compared for deformity correction. All patients were operated on by the senior author or a senior foot and ankle trainee during fellowship using the same surgical technique, and all patients followed a standardized postoperative rehabilitation protocol.

RESULTS

Mean time to union for all 33 NC fusions was 21.7 ± 2 weeks (mean ± SEM). One patient underwent revision for nonunion, resulting in an arthrodesis rate of 97%. For NC fusions in those with planovalgus feet, an improvement in mean lateral talus-first metatarsal angle (Meary's line) from 12.3 ± 1.3 degrees to 5.2 ± 1.2 degrees (P < .05) was found. There was also a mean improvement in talonavicular coverage angle from 14.1 ± 1.8 degrees to 7.4 ± 1.3 degrees (P < .05). There were 2 superficial wound infections that were successfully treated with oral antibiotics, there were no cases of deep vein thrombosis or pulmonary embolism, and all patients came out of cast at 6 weeks into a fixed angle boot to commence weight bearing. Patients were happy with 32 of the 33 procedures and required no further treatment for their condition.

CONCLUSIONS

NC fusion was a safe and predictable procedure for any of its indications, with a fusion rate similar to that of other joints in the foot albeit with a longer time to union. For patients with symptomatic and flexible planovalgus feet, NC fusion resulted in deformity correction in multiple planes and good symptomatic relief.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Long-term outcomes of muscle volume and Achilles tendon length after Achilles tendon ruptures

PURPOSE

The best treatment for Achilles tendon (AT) ruptures remains controversial. Long-term follow-up with radiological and clinical measurements is needed.

METHODS

In this retrospective multicentre cohort study, patients (n = 52) were assessed at a mean of 91 months follow-up after unilateral AT rupture treated by open, percutaneous or conservative (non-surgical) treatment. Demographic parameters, time off work, maximum calf circumference and clinical scores (ATRS, Hannover, AOFAS) were evaluated. Muscle volume and cross-sectional area of the calf and AT length were measured on MR images and were compared between groups and to each patient's healthy contralateral leg.

RESULTS

Reduced muscle volume was found across all groups with a higher muscle volume in the conservative (729.9 ± 130.3 cm(3)) compared to the percutaneous group (675.9 ± 207.4 cm(3), p = 0.04). AT length was longer in the affected leg (198.4 ± 24.1 vs. 180.6 ± 25.0 mm, p < 0.0001) without difference in subgroup analysis. Clinically measured ankle dorsiflexion showed poor correlation with AT length (R (2) = 0.07, p = 0.008). Muscle volume strongly correlated with the cross-sectional area (R (2) = 0.6, p < 0.0001) but showed a weak correlation with the Hannover score (R (2) = 0.08, p = 0.048). Maximum calf circumference correlated with muscle volume (R (2) = 0.42, p < 0.0001).

CONCLUSIONS

No significant difference between the treatment groups was found in muscle volume, AT length, clinical measures or days off work. Cross-sectional area and maximum calf circumference are cost-effective measurements and a good approximation of muscle volume and can thus be used in a clinical setting while clinical dorsiflexion should not be used.

Physiological Achilles tendon length and its relation to tibia length

OBJECTIVE

The optimal intraoperative Achilles tendon length (ATL) adjustment is crucial for the physiological functioning of the musculotendinous unit. To date, the resting ATL and its relation to tibia length (TL) have never been defined in healthy subjects. We thus performed metric measurements of the ATL and TL.

DESIGN

Case series.

SETTING

Clinical and radiological measurements.

PARTICIPANTS

Fifty-two subjects placed in a 3-T magnetic resonance imaging with the ankle in neutral position.

MAIN OUTCOME MEASURES

Unilateral ATL measured from the calcaneal insertion to the beginning of the medial gastrocnemius muscle, TL measured from the intercondylar eminence to the center of the ankle, and qualitative tendon parameters in T2 sequences and human parameters were noted; results were correlated with age, gender, body height, weight, body mass index (BMI), and side of the AT and TL.

RESULTS

The mean ATL was 180.6 ± 25.0 mm and the mean TL was 371.9 ± 25.4 mm with an ATL:TL ratio of 49 ± 5%. Achilles tendon length correlated significantly with body height (R = 38%, P < 0.0001) and with TL (R = 41%, P < 0.0001) but did not correlate with age, BMI, and side of the AT. Tibia length correlated with body height (R = 83%, P < 0.0001) and in multivariate linear regression, TL was the only independent predictor of ATL following the algorithm, ATL (mm) = 0.6 × TL (mm) - 53 (R = 41%).

CONCLUSIONS

We defined a new way to measure the ATL in a consistent way in healthy subjects and showed correlations between ATL, TL and body height and defined an algorithm of ATL based on TL. The ATL and the ATL-algorithm might be important in patients with impaired tendons such as AT ruptures.

Young's procedure for the treatment of valgus flatfoot deformity caused by a posterior tibial tendon dysfunction, stage II

Young’s procedure contains an action mechanism that works better than other techniques on the pathophysiology of FFD. It respects the anatomy and biomechanics of the foot to reach the necessary muscular balance. The benefits of this technique include that the ATT is not detached, so its function mechanism is still active; the new trajectory of the ATT provides a powerful sling function at the level of the navicular; and the horizontal trajectory of the ATT and the osteoperiosteal flaps constitute a powerful inner capsular–tendinous–ligamentous support. What is more, an insufficiency of the ATT is created, which results in a predominance of the peroneus lateral longus, that descends and prones the forefoot. Additional procedures, such as medial displacement calcaneal osteotomy, should be considered to correct the entire deformity. The combination of these techniques do not sacrifice the joint mobility.

Validity of the posterior tibial edema sign in posterior tibial tendon dysfunction

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a common malady leading to acquired flatfoot, which frequently causes foot and ankle pain and swelling. We hypothesized that patients with PTTD and pitting edema along the course of the posterior tibial tendon (PTT) would have evidence of fluid within the tendon sheath on MRI. We introduce and validate a novel, yet simple physical examination finding, the posterior tibial edema (PTE) sign, to help distinguish PTTD from other causes of foot and ankle pain and swelling.

PATIENTS AND METHODS

To determine an association between the PTE sign and changes to the PTT evident on MRI, we reviewed the medical records of patients with PTTD who underwent magnetic resonance imaging (MRI).

RESULTS

Of 186 patients identified with PTTD, 49 underwent MRI, and 42 (86%) demonstrated imaging characteristics consistent with tendonitis, tendinosis, or tenosynovitis. Presence or absence of increased posterior malleolar pitting edema agreed with presence or absence of these MRI findings in 43 patients (88%), making the clinical examination finding significantly predictive of MRI results (p= 0.01). The sensitivity of the test for PTE was 86%, with specificity of 100%.

CONCLUSION

The PTE sign refers to pitting edema along the course of the PTT, not associated with acute trauma and not accompanied by other areas of edema. Physical examination signs that are highly sensitive and specific to the condition may help lower the cost of diagnosis by eliminating the need for expensive tests that are not always necessary.

Tibialis posterior in health and disease: a review of structure and function with specific reference to electromyographic studies

Tibialis posterior has a vital role during gait as the primary dynamic stabiliser of the medial longitudinal arch; however, the muscle and tendon are prone to dysfunction with several conditions. We present an overview of tibialis posterior muscle and tendon anatomy with images from cadaveric work on fresh frozen limbs and a review of current evidence that define normal and abnormal tibialis posterior muscle activation during gait. A video is available that demonstrates ultrasound guided intra-muscular insertion techniques for tibialis posterior electromyography.Current electromyography literature indicates tibialis posterior intensity and timing during walking is variable in healthy adults and has a disease-specific activation profile among different pathologies. Flat-arched foot posture and tibialis posterior tendon dysfunction are associated with greater tibialis posterior muscle activity during stance phase, compared to normal or healthy participants, respectively. Cerebral palsy is associated with four potentially abnormal profiles during the entire gait cycle; however it is unclear how these profiles are defined as these studies lack control groups that characterise electromyographic activity from developmentally normal children. Intervention studies show antipronation taping to significantly decrease tibialis posterior muscle activation during walking compared to barefoot, although this research is based on only four participants. However, other interventions such as foot orthoses and footwear do not appear to systematically effect muscle activation during walking or running, respectively. This review highlights deficits in current evidence and provides suggestions for the future research agenda.

Ankle and foot kinematics associated with stage II PTTD during stance

BACKGROUND

Subjects with stage II posterior tibial tendon dysfunction (PTTD) exhibit abnormal foot kinematics; however, how individual segment kinematics (hindfoot (HF) or first metatarsal (first MET) segments) influence global foot kinematics is unclear. The purpose of this study was to compare foot and ankle kinematics and sagittal plane HF and first MET segment kinematics between stage II PTTD and controls.

MATERIALS AND METHODS

Thirty patients with stage II PTTD and 15 healthy controls were evaluated. Kinematic data from the tibia, calcaneus, and first MET were collected during walking using three dimensional motion analysis techniques. A three-segment foot model (HF, calcaneus; first MET, first metatarsal, and tibia) was used to calculate relative angles (ankle, HF relative to tibia; midfoot, first MET relative to HF) and segment angles (HF and first MET relative to the global). A mixed effect ANOVA model was utilized to compare angles between groups for each variable.

RESULTS

Patients with PTTD showed greater ankle plantarflexion (p = 0.02) by 6.8 degrees to 8.4 degrees prior to or at 74% of stance; greater HF eversion (p < 0.01) across stance (mean difference = 4.5 degrees); and greater first MET dorsiflexion (p < 0.01) across stance (mean difference = 8.8 degrees). HF and first MET segment angles revealed greater HF dorsiflexion (p = 0.01) during early stance and greater first MET dorsiflexion (p = 0.001) across stance.

CONCLUSION

Abnormal HF and first MET segment kinematics separately influence both ankle and midfoot movement during walking in subjects with stage II PTTD.

CLINICAL RELEVANCE

These abnormal kinematics may serve as another measure of response to clinical treatment and/or guide for clinical strategies (exercise, orthotics, and surgery) seeking to improve foot kinematics.

Intramedullary screw fixation in proximal fifth-metatarsal fractures in sports: clinical and biomechanical analysis

INTRODUCTION AND PURPOSE

Intramedullary screw fixation (ISF) of proximal fifth-metatarsal fractures is known as first treatment option in young, sports active patients. No study analyzed functional and biomechanical outcome before. Hypothetically ISF leads to (1) a high bony union rate within 12 weeks, (2) normal hindfoot eversion strength, and (3) normal gait and plantar pressure distribution.

METHODS

Fourteen out of 22 patients were available for follow-up with an average follow-up of 42 months; clinical and radiological follow-up, and biomechanical evaluation by isometric muscular strength measurement (inversion, eversion strength) and dynamic pedobarography, comparing to the non-affected contralateral foot. Level of significance: 0.05.

RESULTS

Subjective result: Excellent or good result in 14 patients, none fair or poor. AOFAS midfoot score: 100 points in 13 patients and 87 points in 1 patient. The same sports activity level (0-4) was reached in 13 out of 14 patients. Radiologic examination: consolidation after 6 weeks in 9 patients and after 12 weeks in another 4 patients, one partial union. Average maximal eversion strength 59 N (ratio to the contralateral foot: 0.92, not significant). Dynamic pedobarography showed ratios of 0.99-1.01 to the contralateral side for ground reaction force, ground peak time, peak pressure and contact area (not significant).

INTERPRETATION

A very-high patient-satisfaction, a fast bony healing and complete return to sports were documented. Muscular strength measurement and dynamic pedobarography showed complete functional rehabilitation. Therefore, ISF in proximal fifth-metatarsal fractures can be recommended as a secure procedure.

The effect of Stage II posterior tibial tendon dysfunction on deep compartment muscle strength: a new strength test

BACKGROUND

The purpose of this study was to compare isometric subtalar inversion and forefoot adduction strength in subjects with Stage II posterior tibial tendon dysfunction (PTTD) to controls.

MATERIALS AND METHODS

Twenty four subjects with Stage II PTTD and fifteen matched controls volunteered for this study. A force transducer (Model SML-200, Interface, Scottsdale, AZ) was connected with a resistance plate and oscilloscope (TDS 410A, Tektronix, Beaverton, OR) to the foot. Via the oscilloscope, subjects were given feedback on the amount of force produced and muscle activation of the anterior tibialis (AT) muscle. Subjects were instructed to maintain a plantar flexion force while performing a maximal voluntary subtalar inversion and forefoot adduction effort. A two-way ANOVA model with the factors including, side (involved/uninvolved) and group (control/PTTD) was used.

RESULTS

The PTTD group on the involved side showed significantly decreased subtalar inversion and foot adduction strength (0.70 +/- 0.24 N/Kg) compared to the uninvolved side (0.94 +/- 0.24 N/Kg) and controls (involved side = 0.99 +/- 0.24 N/Kg, uninvolved side = 0.97 +/- 0.21 N/Kg). The average AT activation was between 11% to 17% for both groups, however, considerable variability in subjects with PTTD.

CONCLUSION

These data confirm a subtalar inversion and forefoot adduction strength deficit by 20% to 30% in subjects with Stage II PTTD. Although isolating the PT muscle is difficult, a test specific to subtalar inversion and forefoot adduction demonstrated the weakness in this population.

The flexible flatfoot in the adult

The adult acquired flatfoot deformity is characterized by flattening of the medial longitudinal arch with insufficiency of the supporting posteromedial soft tissue structures of the ankle and hindfoot. While the etiology of this deformity can be arthritic or traumatic in nature, it is most commonly associated with posterior tibial tendon dysfunction (PTTD). By one estimate, PTTD affects approximately five million people in the United States. The clinical presentation of adult flatfoot can range from a flexible deformity with normal joint integrity to a rigid, arthritic foot.

The Cobb procedure for treatment of acquired flatfoot deformity associated with stage II insufficiency of the posterior tibial tendon

BACKGROUND

A supple flatfoot deformity caused by posterior tibial tendon (PTT) dysfunction may include a supination deformity of the forefoot that usually is not sufficiently corrected by the commonly suggested treatment options. The use of a partial anterior tibial tendon (ATT) graft that is rerouted through the first cuneiform to the proximal stump of the PTT may restore plantarflexion power of the first ray (Cobb procedure).

METHODS

Twenty-two consecutive patients with stage II PTT dysfunction and a supple supination deformity of the forefoot were included. A clinical examination, a subjective score, and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale were evaluated.

RESULTS

The mean AOFAS score increased from preoperatively 53.2 (range 40 to 68) to 88.5 (range 78 to 94) at a followup of 24 (range 12 to 46) months. The overall clinical results were excellent in nine patients (41.0%), good in 12 (54.5%), fair in one (4.5%), and poor in none. None of the patients had decreased power of the anterior tibial tendon compared to the contralateral foot. Nineteen patients (86%) were able to wear shoes without shoe modifications.

CONCLUSIONS

The Cobb procedure provided satisfactory correction of associated forefoot supination deformity in stage II PTT dysfunction. All patients had improved function because of the increased stability of the first ray. There was no evidence of loss of ATT power. The Cobb procedure may be considered an appropriate alternative to arthrodeses in selected patients with supple supination deformity in flatfeet.

The relationship between ankle, hindfoot, and forefoot position and posterior tibial muscle excursion

BACKGROUND

The purpose of this study was to examine the relationship of forefoot position in the transverse plane (abduction/adduction), hindfoot position in the frontal plane (eversion/inversion), and ankle position in the sagittal plane (plantarflexion/dorsiflexion) with posterior tibialis (PT) muscle excursion using an in vitro cadaver model.

METHODS

Seven fresh-frozen cadaver specimens were potted and mounted on a frame. The PT tendon was dissected 15 cm proximal to the medial malleolus, and a 5-kg weight was sutured to the tendon. A six-camera motion analysis system (Optotrak, Northern Digital, Inc.) was used to track three-dimensional (3-D) motion of the tibia, calcaneus (hindfoot) and first metatarsal (forefoot) using bone pins. The ankle, hindfoot, and forefoot were manually placed in 24 different ankle and foot positions. A stepwise regression analysis was used to examine the relationship among ankle, hindfoot, and forefoot kinematics and PT muscle excursion.

RESULTS

Hindfoot eversion/inversion and forefoot abduction/adduction accounted for 77% of the variance in PT muscle excursion, with small contributions from ankle plantarflexion/dorsiflexion (5.7%) and forefoot plantarflexion/dorsiflexion (1.9%). A combined regression equation applied to individual specimens resulted in average errors of less than 2.5 mm.

CONCLUSIONS

This study supports the hypothesis that PT muscle excursion can be estimated using specific foot and ankle kinematic variables. Further, these data suggest that hindfoot eversion and forefoot abduction account for most of the variance in PT muscle excursion and are theorized to be important to control clinically altering the length of the posterior tibial muscle.

Combined anterior tibial tendon rupture and posterior tibial tendon dysfunction in advanced flatfoot

The combination of spontaneous anterior tibial tendon rupture and posterior tibial tendon dysfunction has rarely been reported in the literature. This is a case report of a 78-year-old patient presenting with a history of longstanding, progressive flatfoot deformity, clinically grade III posterior tibial tendon dysfunction, and dropfoot gait. Radiographic films revealed severe flatfoot, and the clinical examination was consistent with a complete rupture of the anterior tibial tendon and severe posterior tibial tendon degeneration as well as rupture of the spring and deltoid ligaments. Treatment by triple arthrodesis and repair of the anterior tibial tendon affected pain relief and clinical as well as radiographic correction at the 4-month postoperative assessment.

Comparison of foot kinematics between subjects with posterior tibialis tendon dysfunction and healthy controls

STUDY DESIGN

A 2 x 4 mixed-design ANOVA with a fixed factor of group (posterior tibialis tendon dysfunction [PTTD] and asymptomatic controls), and a repeated factor of phase of stance (loading response, midstance, terminal stance, and preswing).

OBJECTIVE

To compare 3-dimensional stance period kinematics (rearfoot eversion/inversion, medial longitudinal arch [MLA] angle, and forefoot abduction) of subjects with stage II PTTD to asymptomatic controls.

BACKGROUND

Abnormal foot postures in subjects with stage II PTTD are clinical indicators of disease progression, yet dynamic investigations of forefoot, midfoot, and rearfoot kinematic deviations in this population are lacking.

METHODS

Fourteen subjects with stage II PTTD were compared to 10 control subjects with normal arch index values. Subjects were matched for age, gender, and body mass index. A 5-segment, kinematic model of the leg and foot was tracked using an Optotrak Motion Analysis System. The dependent kinematic variables were rearfoot inversion/eversion, forefoot abduction/adduction, and the MLA angle. An ANOVA model was used to compare kinematic variables between groups across 4 phases of stance.

RESULTS

Subjects with PTTD demonstrated significantly greater rearfoot eversion (P = .042), MLA angle (P = .008) and forefoot abduction angles (P < .005) during specific phases of stance. Subjects with PTTD demonstrated significantly greater rearfoot eversion (P<.004) and MLA angles (P < .009) by 6.2 degrees and 8.0 degrees, respectively, during loading response when compared to controls. During preswing, the subjects with PTTD demonstrated a significantly greater MLA angle (P < .002) and a forefoot abduction angle (P<.001) which exceeded that of the controls by 10.0 degrees.

CONCLUSIONS

The abnormal kinematics observed at the rearfoot, midfoot, and forefoot across all phases of stance implicate a failure of compensatory muscle and secondary ligamentous support to control foot kinematics in subjects with stage II PTTD.

The response of the flexor digitorum longus and posterior tibial muscles to tendon transfer and calcaneal osteotomy for stage II posterior tibial tendon dysfunction

BACKGROUND

The purpose of this prospective study was to evaluate the response of the flexor digitorum longus (FDL) and posterior tibial (PT) muscles to FDL tendon transfer and medial displacement calcaneal osteotomy for stage II posterior tibial tendon dysfunction (PTTD).

METHODS

Twelve patients were divided into two groups, depending on whether the PT tendon was excised (Excised Tendon Group) or left intact (Intact Tendon Group). The muscle volumes of the FDL and PT muscles in both legs were measured and compared, using cross-sectional area (CSA) analysis of preoperative and postoperative MRI.

RESULTS

Preoperatively, there was an average 11% reduction in the PT muscle volume and a 17% increase in the FDL muscle volume from the normal contralateral side in both groups. One year after surgery (average 13.4 months) in both groups, the FDL muscle volume had increased by an average of 27% and the PT muscle volume had decreased by 23% compared to the contralateral normal side. The FDL volume increased by 44% in the Excised Tendon Group compared to 11% in the Intact Tendon Group. The PT muscle volumes were not assessed in the Excised Tendon Group because all PT muscle had been replaced by fatty infiltration. The PT volumes in the Intact Tendon Group decreased further from a 6% reduction preoperatively to a 23% reduction postoperatively compared to the normal contralateral side. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scores increased from 50 preoperatively to 88 at 1 year after surgery. There was no difference in the scores between the Excised Tendon (47 to 87) and Intact Tendon (53 to 89) groups.

CONCLUSION

We concluded that the FDL muscle hypertrophies in response to a failing PT muscle. This hypertrophy continues after FDL transfer and medial displacement calcaneal osteotomy. With excision of the PT tendon, the FDL undergoes greater hypertrophy than if the tendon is left attached. The PT muscle continues to atrophy and undergoes complete fatty replacement if the tendon is excised. Transfer of the FDL and medial displacement calcaneal osteotomy produce a satisfactory improvement in hindfoot function; the outcome was the same whether the PT tendon was sacrificed or left intact.