Compensatory mechanisms for proximal & distal joint alignment & gait in varus knee osteoarthritis treated with high tibial osteotomy: A systematic review

Background

Varus deformity is common in medial compartment knee osteoarthritis (OA). This coronal plane malalignment is compensated for by static and dynamic adjustments in the position of the adjacent joints, principally in the hindfoot & ankle. Varus knee OA can be treated in selected patients with high tibial osteotomy (HTO) and stabilised with a fixed angle plate or circular frame, which may reverse these compensatory adjustments. The aim of this systematic review is to determine the evidence available for static and dynamic compensations with the main objectives being to improve deformity planning and optimise patient outcomes.

Method

A systematic review with meta-analysis was designed using the PRISMA template to meet the research aims & objectives.

Results

A total of 1006 patients (1020 knees) with acombined mean age of 54.5 years, female:male ratio of 0.9:1 were extracted from 19 included studies. The methodologies of the majority of studies were at high risk of bias according to the Newcastle-Ottawa Scale demonstrating significant heterogeneity. The combined mean change in the HKA axis was 7.7°; MPTA 7.4°; TT, 0.21°; TI 4.56° & AJLO 4° valgus. Preoperative hindfoot valgus compensation reverts towards neutral post-HTO. There is limited evidence available for a direct relationship between static alignment and dynamic gait parameters.

Conclusions

An inverse relationship between ankle and hindfoot alignment in varus deformity of the knee forms the basis of this compensation theory. In cases with a stiff hindfoot which may not revert postoperatively, the reconstructive orthopaedic surgeon may consider angulation with translation HTO, in order to optimise joint alignment and minimise transference of symptoms to the foot and ankle.

Lateralizing calcaneal osteotomy performed with a percutaneous burr results in a significantly lower increase in tarsal tunnel pressure

PURPOSE

Tarsal tunnel syndrome is well documented following lateralizing calcaneal osteotomy to manage varus hindfoot deformity. Traditionally, calcaneal osteotomy is performed with an oscillating saw. No studies have investigated the effect of alternative surgical techniques on postoperative tarsal tunnel pressure. The purpose of this study was to investigate the difference in tarsal tunnel pressures following lateralizing calcaneal osteotomy performed using a high-torque, low-speed "minimally invasive surgery" (MIS) Shannon burr versus an oscillating saw.

METHODS

Lateralizing calcaneal osteotomy was performed on 10 below-knee cadaveric specimens. This was conducted on 5 specimens each using an oscillating saw (Saw group) or MIS burr (Burr group). The calcaneal tuberosity was translated 1 cm laterally and transfixed using 2 Kirschner wires. Tarsal tunnel pressure was measured before and after osteotomy via ultrasound-guided percutaneous needle barometer. Mean pre/post-osteotomy pressures were compared between groups. Differences were analyzed using Student's t test.

RESULTS

The mean pre-procedure tarsal tunnel pressure was 25.8 ± 5.1 mm Hg in the Saw group and 26.4 ± 4.3 mm Hg in the Burr group (p = 0.85). The mean post-procedure pressure was 63.4 ± 5.1 in the Saw group and 47.8 ± 4.3 in the Burr group (p = 0.01). Change in tarsal tunnel pressure was significantly lower in the Burr group (21.4 ± 4.5) compared to the Saw group (37.6 ± 12.5) (p = 0.03). The increase in tarsal tunnel pressure was 43% lower in the Burr group.

CONCLUSION

In this cadaveric study, tarsal tunnel pressure increase after lateralizing calcaneal osteotomy was significantly lower when using a burr versus a saw. This is likely because the increased width ("kerf") of the 3 mm MIS burr, compared to the submillimeter saw blade width, causes calcaneal shortening. Given the smaller increase in tarsal tunnel pressure, using the MIS burr for lateralizing calcaneal osteotomy may decrease the risk of postoperative tarsal tunnel syndrome. Future research in vivo should explore this.

Outcomes following tibiotalocalcaneal arthrodesis using a solid posterior offset intramedullary nail in 44 patients with a minimum 30-month follow-up

BACKGROUND

Tibiotalocalcaneal arthrodesis is frequently performed by foot and ankle surgeons in the management of complex ankle and hindfoot pathology. In this study, the authors describe the clinical and radiological outcomes of tibiotalocalcaneal arthrodesis using a solid posterior offset hindfoot arthrodesis nail.

METHODS

Forty-four consecutive patients underwent tibiotalocalcaneal arthrodesis by a single surgeon operating in two centers. Clinical and radiological outcomes were assessed preoperatively and at 6-month, 12-month and final follow-up (mean 47 months). Clinical outcomes were assessed with VAS, AOFAS and MOXFQ scores. Serial radiographs were used to assess union at each follow-up visit.

RESULTS

Forty-four patients attended 12-month and final follow-up (mean 47 months). A total of 44 (100%) ankle joints and 44 (100%) subtalar joints were completely united at 12-month follow-up. The VAS score improved significantly from a mean of 6.5 preoperatively to a mean of 0.98 at final follow-up (P = <0.0001). AOFAS score improved significantly from a mean of 36.4 preoperatively to a mean of 73 at final follow-up (P = <0.0001). MOXFQ score improved significantly from a mean of 44.5 preoperatively to a mean of 12.7 at final follow-up (P = <0.0001). The mean change in frontal plane alignment was 5.7 degrees (P = 0.005). A total of 6 patients (13.6%) had an adverse event during the course of the study.

CONCLUSIONS

Tibiotalocalcaneal arthrodesis with a solid posterior offset hindfoot arthrodesis nail is a safe and effective surgical option for patients with severe ankle and hindfoot pathology. It has a high union rate, low complication rate and significantly improves clinical outcomes.

Surgical management of Charcot foot - The advancements over the past decade

Charcot neuroarthropathy is a progressive, destructive condition leading to deformity, dysfunction and, in some cases, amputation. Much evolution has occurred over the last couple of decades in the management of Charcot foot with a focus on developing limb salvage and reconstructive techniques. The aim has been to achieve a stable plantigrade foot that remains pain and ulcer-free whilst reducing amputation rates. Soft tissue and bony reconstructions have been explored, and various modalities of fixation, including internal, external, and combined techniques, have been described and their outcomes published. Currently, no strong evidence exists which supports a particular modality of treatment, nor have there been any randomised studies to this effect, but the results are nevertheless promising. Recent studies have reported on minimally invasive techniques, the use of super construct fixation, computer-navigated deformity correction, the efficacy of techniques such as subtalar arthrodesis or tendon balancing procedures and staged deformity corrections. There is a need for more controlled and comparative studies with consistent reporting of intended outcomes to create a stronger portfolio of evidence on the surgical management of Charcot foot.

"Foot peak pressures are comparable to normal foot after flexor hallucis longus transfer for chronic retracted tendo-achilles tear: A pedobarographic analysis of normal foot versus affected foot"

INTRODUCTION

Foot pressure changes and morbidity after flexor hallucis longus (FHL) transfer in chronic retracted tendoachilles (TA) tears have not been documented. The primary aim of our study is to analyze the peak pressure changes in various zones of the foot at each successive follow-up in the affected foot versus normal foot. The secondary aim is to determine FHL tendon healing and muscle hypertrophy.

METHODS

This is a prospective study of 46 patients who underwent FHL augmentation for chronic retracted TA tears (between 2019 and 2022). Included TA tear > 6 weeks duration and retraction > 2.5 cm. Excluded open TA tear, < 6 weeks and retraction < 2.5 cm. Depending on the amount of retraction, FHL augmentation combined with TA repair/VY plasty/turn-down-plasty. Functional outcome was analyzed with AOFAS hallux metatarsophalangeal scale. Pedobarographic analysis was done pre-operatively and at 3, 6, 9 months, 1 year and at the final follow-up. Parameters studied included forefoot peak pressure (FFPP), hindfoot peak pressure (HFPP), great toe peak pressure (GTPP), first Mmeta-tarso phalangeal peak pressure (MTPP), area under the pedobarograph and maximum force. At final follow-up MRI was done to assess FHL healing and hypertrophy. Statistical analysis was done for these parameters using appropriate tests.

RESULTS

Study involved 29 male and 17 female patients, mean age 49.5 years (33-65 years) and mean follow-up 26.8 months (14-38.4months). Mean hallux MTP-AOFAS score increased from 46.04 ± 7.31 preoperatively to 96.17 ± 3.22 at the final follow-up (P < 0.01). There was gradual improvement noted in FFPP, GTPP, MTPP Peak pressures at subsequent follow-ups, and by the end of 1-year foot pressures were comparable to normal side FFPP (8.02 ± 3.8 N/cm2 to 31.35 ± 3 N/cm2), GTPP(30.78 ± 13.01 N/cm2 to23.17 ± 7.5 N/cm2), MTPP(5.22 ± 2.64 N/cm2 to 23.3 ± 9.6 N/cm2). Initial high HFPP showed decline in subsequent follow-up and restored back to normal HFPP (36.91 ± 5.7 N/cm2 to 25.09 ± 3.7 N/cm2). Changes in pressures were statistically significant (< 0.001). Six patients had superficial wound infections healed with antibiotics. 23 patients who underwent a post-operative MRI showed a mean of 27 mm muscle thickness and 7.1 mm tendon thickness with complete incorporation of the FHL.

CONCLUSION

Foot peak pressures though initially deranged, are restored and comparable to normal foot after FHL transfer for chronic retracted TA tear. FHL hypertrophy is observed at the muscle thickness and at the distal tendon and provides adequate strength to repair and restore foot pressures.

LEVEL OF EVIDENCE III

Prospective comparative study (normal versus operated foot).

Imaging of osteoarthritis from the ankle through the midfoot

Ankle, hindfoot, and midfoot osteoarthritis (OA) is most commonly posttraumatic and tends to become symptomatic in younger patients. It often results from instability due to insufficiency of supportive soft tissue structures, such as ligaments and tendons. Diagnostic imaging can be helpful to detect and characterize the distribution of OA, and to assess the integrity of these supportive structures, which helps determine prognosis and guide treatment. However, the imaging findings associated with OA and instability may be subtle and unrecognized until the process is advanced, which may ultimately limit therapeutic options to salvage procedures. It is important to understand the abilities and limitations of various imaging modalities used to assess ankle, hindfoot, and midfoot OA, and to be familiar with the imaging findings of OA and instability patterns.

Pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee

BACKGROUND

In recent years, the involvement of the compensation ability of the subtalar joint in lower extremity alignment has been reported. We previously showed that hindfoot alignment angle (HAA) is an indicator of compensation ability of the subtalar joint. The abnormal compensation ability of the subtalar joint was defined by the mobility of the subtalar joint, and evaluation of the mobility of the subtalar joint may help to further clarify the pathophysiology of abnormal compensation ability of the subtalar joint. This study was performed to evaluate the mobility of the subtalar joint and clarify the pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee.

METHODS

Seventy-two knees of 72 patients aged ≥40 years with varus knee were included in this study. Preoperative radiographs were used for measurement of this study parameters. Based on our previous study, we defined HAA of ≥15.9°as abnormal compensation ability of the subtalar joint. The patients were divided into an abnormal group (A-group) and normal group (N-group). All measurement parameters were compared between the groups, and correlations between the HAA and each measurement parameter were analyzed.

RESULTS

The weight-bearing hindfoot angle (WBHA) (p < 0.001) and non-weight-bearing hindfoot angle (non-WBHA) (p = 0.003), were significantly greater in the A-group than in the N-group. Conversely, the ratio of change in hindfoot alignment (p = 0.006), were significantly smaller in the A-group than in the N-group. The HAA was positively correlated with WBHA (r = 0.66) and non-WBHA (r = 0.43) and negatively correlated with the ratio of change in hindfoot alignment (r = -0.32).

CONCLUSIONS

The pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee is thought to involve a state of increased valgus of hindfoot alignment and an inability to move into normal hindfoot alignment.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective study.

Ankle and subtalar joint axes of rotation and center of rotation during walking and running in healthy individuals measured using dynamic biplane radiography

The goal of this study was to determine how foot type and activity level affect ankle and hindfoot motion. Dynamic biplane radiography and a validated volumetric registration process was used to measure ankle and hindfoot motion of 20 healthy adults during walking and running. The helical axes of motion (HAM) during stance were calculated at the tibiotalar and subtalar joints. The intersection of each HAM and the rotation plane of interest defined the tibiotalar and subtalar centers of rotation (COR). Correlations between foot type and hindfoot kinematics were calculated using Pearson's correlations. The effect of activity, phase of gait, and dominant vs. non-dominant limb on HAM and COR were evaluated using linear mixed effects models. Activity and phase of gait influenced the superior location of the tibiotalar (p < 0.041) and subtalar (p < 0.044) CORs. Activity and gait phase affected tibiotalar (p < 0.049) and subtalar (p < 0.044) HAM direction during gait. Both HAM orientation and COR location changed with activity and phase of gait. These ankle and hindfoot kinematics have implications for total ankle replacement design and musculoskeletal models that estimate force and moment generating capabilities of muscles.

Cone-Beam Weight-Bearing Computed Tomography of Ankle Arthritis and Total Ankle Arthroplasty

Weight-bearing computed tomography has multiple advantages in evaluating the hindfoot and ankle. It can assess hindfoot and ankle alignment, pathology in ankle arthritis, and complications related to total ankle replacements. It is an essential tool in ankle osteoarthritis diagnostic, preoperative planning, and total ankle replacement outcomes. It allows for better accuracy and reproducibility of alignment and implant size. In addition, it has the potential to more assertively detect complications related to weight bearing.

Functional and oncological outcome of patients with benign hindfoot tumors treated by curettage

BACKGROUND

Only 3 % of osseous tumors occur in the foot. The metatarsals are the -most common site whereas the calcaneus and talus are less common sites. Because these tumors are rare, the aim of our study is to assess the functional and the oncological outcome of patients with benign hindfoot tumors managed by curettage.

METHODS

The clinical and radiological data of 41 patients diagnosed with benign hindfoot tumors were retrospectively reviewed. The study included 31 males and 10 females. The average age was 23.68 (range, 5-49) years. The average follow-up period was 92.7 (range, 12-244) months.

RESULTS

At the last follow-up visit, the average Musculoskeletal Tumor Society scoring system (MSTS) score was 28.12 (range, 21-30). MSTS scores were higher in patients with latent tumors (P = .028) and patients managed by simple curettage (P = .018). The recurrence rate in calcaneal tumors was higher than those in the talus. The overall complication rate was 12.2 % (5 of 41 patients). Infection and subtalar arthritis were the most common complications.

CONCLUSION

Curettage of benign bone tumors of talus or calcaneus proved to be an effective method in the management of these patients. Their functional outcome is also excellent. All the complications are manageable without long term morbidity.

LEVEL OF EVIDENCE

Level IV Therapeutic study.

Comparison of the effect of total knee arthroplasty and high tibial osteotomy on coronal pelvic and ankle-hindfoot alignment

BACKGROUND

Total knee arthroplasty (TKA) and high tibial osteotomy (HTO) are different procedures on the continuous spectrum of osteoarthritic knee treatments. TKA aims for neutral alignment and HTO aims for slight valgus.

METHODS

2:2:2:1 propensity score matching yielded 100, 100, 100, and 50 patients with unilateral TKA, bilateral TKA, unilateral HTO, and bilateral HTO, respectively. Radiological evaluations of pelvis, knee, ankle, and hindfoot were performed. The important factors affecting the alignment change of the adjacent joints were identified, and subgroup analyses were performed using the identified parameters. The clinical outcomes were also compared.

RESULTS

The coronal alignments of the adjacent joints were corrected to the neutral position after TKA and HTO. The tibiotalar tilt angle (TTTA) was a common factor that affected changes in the ankle and hindfoot alignment. Patients with larger preoperative TTTA showed larger changes in TTTA in both TKA and HTO groups (P < 0.001). Patients with larger preoperative hindfoot alignment angle (HAA) showed larger changes in tibial plafond inclination, talar inclination, and HAA in both TKA and HTO groups (P < 0.001). TKA groups showed negative pelvic tilt values in the horizontal plane, and HTO groups showed a larger weight-bearing line ratio.

CONCLUSION

Even more severe deformities including adjacent joints were observed in TKA patients, both TKA and HTO patients showed improved alignment of the adjacent joints. However, HTO patients showed closer normal alignment than patients who underwent TKA. The preoperative TTTA and HAA were important factors for restoration of ankle and hindfoot alignment after knee surgery.

Definitions and Measurements of Hindfoot Alignment and Their Biomechanical and Clinical Implications

This article presents a critical review of the past and the current state of the art in defining and measuring hindfoot, ankle, and subtalar alignment. It describes the transition occurring at present from two-dimensional to three-dimensional (3D) alignment measurements, which accompany the emergence of new, functional, high-resolution imaging modalities such as the weight-bearing cone-beam computerized tomography (CT) imaging. To ease and enhance the transition and acceptability of 3D alignment measurements, new acceptable standards for different clinical application are highly desirable.

Surgical treatment of a hindfoot plantar leiomyoma: A case study

Leiomyomas within the foot are rare and are difficult to diagnose with only the radiographic and clinical picture. They are benign, slow growing, and very rarely cause pain. We present an unusual case of a dermatology referral patient complaining of callus formation on the plantar aspect of the foot as well as shoe discomfort. The mass was believed to be a lipoma or a fibroma but after surgical excision was found to be a leiomyoma. Our case highlights the rarity of this diagnosis and presents a unique surgical technique utilizing a medial approach to the plantar hindfoot for lesion removal.

Neglected Desmoplastic Fibroma of calcaneum with collapsed hindfoot, restored with allograft transplantation: A rare case report

Desmoplastic fibroma of the calcaneum is a rare, locally aggressive tumour. A 24-year-old female presented with long-standing heel pain, with the collapse of the calcaneum (hindfoot) that was untreated for 7 years. Eradication of this locally aggressive lesion by adjuvant therapy and restoration of calcaneal bony morphology by allograft was an arduous and challenging task. At the final follow-up, the heel was painless, and the patient could walk normally without support.

Conclusion

Restoration of calcaneal height is challenging in young patients, and using structural allograft restores calcaneal and hindfoot morphology. Patient education about the high chances of recurrence despite surgical clearance is essential, and intraoperative adjuvant usage can reduce the recurrence.

The effect of subtalar joint axis location on muscle moment arms

Most dynamic musculoskeletal models define the subtalar joint (STJ) as a one degree of freedom (DOF) hinge with a tri-planar axis. The orientation of this axis of rotation is often determined as a combination of inclination and deviation angles measured from the ground and midline of the foot, respectively. In defining the location of the axis, often the origin is found at the distal aspect of the heel instead of at the articulation of the talus and calcaneus. Key musculoskeletal modeling definitions, such as muscle moment arms, are dependent on the distance and relative location of muscle insertion to the axis of rotation. Since the axis orientation and origin location affect calculations of muscle moment arm and joint dynamics, there is much need for accurate characterization of the STJ axis to understand the STJ's role in dynamic weight-bearing motion. The purpose of this study is to explore how the STJ origin location and axis orientation affect muscle moment arms surrounding the ankle. Datasets from the Grand Knee Challenge, posted on the open-source SimTK website, were modeled using OpenSim. Modifying the location of the STJ axis from the original location closer to the articulation between the talus and calcaneus resulted in significant differences in STJ muscle moment arms and peak STJ moments. The findings of this study conclude that the location of the STJ axis origin needs to be considered and accurately defined, especially if the inclination/deviation angles of the rotational axis will be modified to represent a more subject-specific definition.

Lower limb alignment in patients with primary valgus ankle arthritis: A comparative analysis with patients with varus ankle arthritis and healthy controls

BACKGROUND

While it is commonly acknowledged that the combined effect of lower limb orientation and ankle and hindfoot alignment play a fundamental role in ankle arthritis, supramalleolar/lower limb alignment has received less attention in valgus ankle arthritis. The purpose of this study was to analyze the lower limb alignment of patients with valgus ankle arthritis with primary origin, compared to that of varus ankle arthritis and normal controls. We hypothesized that patients with valgus ankle arthritis would have the opposite pattern of lower limb alignment as those with varus ankle arthritis.

METHODS

A retrospective radiographic analysis was performed on 61 patients (62 ankles, mean age, 59.3 ± 12 years) with primary valgus ankle arthritis. On preoperative radiographs, seven parameters, including talar tilt angle, medial distal tibial angle (MDTA), talar center migration, anterior distal tibial angle, talo-first metatarsal (Meary's) angle, hindfoot moment arm (HMA), and mechanical axis deviation (MAD), were measured and compared to those of primary varus ankle arthritis (n = 55; mean age, 59.7 ± 8.1 years) and control patients (n = 59; mean age, 29.3 ± 7.3 years).

RESULTS

The valgus group had a significantly lower mean MDTA than the control group (p < 0.0001), indicating a varus distal tibial plafond in comparison to the control group. Meary's angle and HMA were significantly lower in the valgus group compared to the varus group (p < 0.05 and p < 0.0001, respectively), indicating a lower medial longitudinal arch and valgus hindfoot alignment. On whole limb radiographs, the valgus group showed a greater MAD than the control group, indicating varus lower limb alignment (p < 0.05). However, the MAD did not differ significantly between the valgus and varus groups (p = 0.7031).

CONCLUSION

Our findings indicate that a significant proportion of ankles with primary valgus arthritis have a varus tibial plafond and a varus lower limb mechanical axis. This study contributes to our understanding of primary valgus ankle arthritis and suggests that lower limb alignment should be analyzed and considered throughout valgus ankle arthritis realignment procedures.

Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy

INTRODUCTION

We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO.

MATERIALS AND METHODS

This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment.

RESULTS

The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees.

CONCLUSION

Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle.

LEVEL OF EVIDENCE

Therapeutic level III, retrospective study.

Modified sinus tarsi approach with a variable-angle locking anterolateral plate for Sanders type II and III calcaneal fractures

BACKGROUND

We compared the effectiveness of the extensile lateral approach (ELA) and modified sinus tarsi approach (MSTA) with a variable-angle locking anterolateral plate in treating Sanders type II and III calcaneal fractures.

METHODS

We reviewed 45 DIACFs treated by a single surgeon from 2017 to 2020. Open reduction using ELA and MSTA was performed in 25 and 20 patients, respectively. Follow-up evaluations included radiological assessments and clinical evaluations.

RESULTS

Pre- and postoperative radiologic parameters for the calcaneus were significantly different. The average American Orthopaedic Foot and Ankle Society scores were 81.24 and 85.00, the mean visual analogue scale scores were 2.28 and 1.65, and the wound-related complication rates were 64.0% and 15.0% in the ELA and MSTA groups, respectively. Bony union was achieved in all cases.

CONCLUSIONS

For Sanders type II and III fractures, MSTA seems to be a safer and more satisfactory method, with fewer postoperative complications.

Predictors of metalwork failure and nonunion after hindfoot Charcot reconstruction

AIMS

Surgical reconstruction of deformed Charcot feet carries a high risk of nonunion, metalwork failure, and deformity recurrence. The primary aim of this study was to identify the factors contributing to these complications following hindfoot Charcot reconstructions.

METHODS

We retrospectively analyzed patients who underwent hindfoot Charcot reconstruction with an intramedullary nail between January 2007 and December 2019 in our unit. Patient demographic details, comorbidities, weightbearing status, and postoperative complications were noted. Metalwork breakage, nonunion, deformity recurrence, concurrent midfoot reconstruction, and the measurements related to intramedullary nail were also recorded.

RESULTS

There were 70 patients with mean follow-up of 54 months (SD 26). Overall, 51 patients (72%) and 52 patients (74%) were fully weightbearing at one year postoperatively and at final follow-up, respectively. The overall hindfoot union rate was 83% (58/70 patients). Age, BMI, glycated haemoglobin, and prior revascularization did not affect union. The ratio of nail diameter and isthmus was greater in the united compared to the nonunited group (0.90 (SD 0.06) and 0.86 (SD 0.09), respectively; p = 0.034). In those with a supplementary hindfoot compression screw, there was a 95% union rate (19/20 patients), compared to 78% in those without screws (39/50 patients; p = 0.038). All patients with a miss-a-nail hindfoot compression screw went on to union. Hindfoot metalwork failure was seen in 13 patients (19%). An intact medial malleolus was found more frequently in those with intact metalwork ((77% (44/57 patients) vs 54% (7/13 patients); p = 0.022) and in those with union ((76% (44/58 patients) vs 50% (6/12 patients); p = 0.018). Broken metalwork occurred more frequently in patients with nonunions (69% (9/13 patients) vs 9% (5/57 patients); p < 0.001) and midfoot deformity recurrence (69% (9/13 patients) vs 9% (5/57 patients); p < 0.001).

CONCLUSION

Rates of hindfoot union and intact metalwork were noted in over 80% of patients. Union after hindfoot reconstruction occurs more frequently with an isthmic fit of the intramedullary nail and supplementary hindfoot screws. An intact medial malleolus is protective against nonunion and hindfoot metalwork failure. Cite this article: Bone Joint J 2022;104-B(6):703-708.

Complete avulsion of the heel pad with talar and calcaneal fracture: salvage with multiple K-wire anchorage, internal fixation and free ALT flap

BACKGROUND

Degloving of the sole of the foot is a rare and serious injury because the heel pad cannot be replaced by similar tissue. The management is challenging and only a few cases have been reported with different treatment regimens.

METHODS

Here, we report on a 46-year-old female patient with complex foot trauma consisting of complete avulsion of the heel pad at the hindfoot and a soft tissue defect at the posterior aspect of the heel accompanied by rupture of the anterior tibial tendon and fractures of the talus, calcaneus and midfoot. The sole of the foot was fixed to the calcaneus with multiple temporary Kirschner wires and moist wound dressings. The anterior tibial tendon was sutured. The soft tissue defect at the posterior heel was treated with a free anterolateral thigh flap. The fractures were fixed in staged procedures.

RESULTS

At 2-year follow-up, the patient had a durable soft tissue cover over the heel with full sensation over the sole and a pliable flap over the posterior aspect of the heel. The patient was able to fully bear weight and was pain free during her daily activities in comfortable, custom shoes. All fractures had healed, the talar neck fracture after one revision and bone grafting. The foot was plantigrade and stable with preserved painless but limited range of motion at the ankle, subtalar and mid-tarsal joints.

CONCLUSION

The unique tissue at the sole of the foot can be salvaged even in cases of full degloving at the hindfoot with the simple method of anchorage with multiple temporary K-wires. Traumatic defects of the vulnerable skin at the posterior aspect of the heel requires durable coverage with free flap coverage. With staged treatment of all bone and soft tissue injuries, a favorable result can be obtained even in case of a complex foot trauma.

Knee varus alters three-dimensional ankle alignment in standing- a study with upright computed tomography

Background

For knee osteoarthritis (OA) treatment, it is important to correct the lower limb alignment including the foot. However, in the upright position, lower limb alignment is generally assessed from the body surface or radiographs, and it is a challenge to capture the exact characteristics of three-dimensional lower limb alignment. The purpose of the study was to measure lower limb alignment in patients with knee OA using upright computed tomography (CT) and radiography, and to identify features of knee joint deformity.

Methods

A total of 45 limbs in 25 patients with knee OA were enrolled. The subjects underwent both upright CT and radiography for the whole lower limb in the standing position. The joint angles were calculated on both images. The degree of knee OA was classified according to Kellgren-Lawrence (KL) grade by referring to radiography, which is mainly based on the degree of articular cartilage loss and severity of osteophytes, and the characteristics or correlation between knee and ankle joint in each group was investigated.

Results

In KL-I, there was an association between varus of the knee joint and internal rotation of the talocrural joint (r = 0.76, P < 0.05). In KL-II, there was an association between varus of the knee joint and eversion of the subtalar joint (r = 0.63, P < 0.05) and talocrural joint (r = − 0.65, P < 0.05). In KL-III, there was an association between varus of the knee joint and internal rotation of the subtalar joint (r = − 0.62, P < 0.05), and in KL-IV, there was an association between varus of the knee joint and internal rotation of the subtalar joint (r = − 0.58, P < 0.05).

Conclusions

The lower limb alignment of patients with knee OA in the standing position was found that as knee OA worsened, it became apparent that compensatory knee joint alignment depended on the ankle joint rather than the subtalar joint. The results may help in the rehabilitation of patients with knee OA, since the ankle joint alignment has a significant impact on the knee joint during coarse movements involving load.

Abnormal Bone Morphology in Charcot-Marie-Tooth Disease

BACKGROUND

Although long suspected, it has yet to be shown whether the foot and ankle deformities of Charcot-Marie-Tooth disease (CMT) are generally associated with abnormalities in osseous shape. Computed tomography (CT) was used to quantify morphologic differences of the calcaneus, talus, and navicular in CMT compared with healthy controls.

METHODS

Weightbearing CT scans of 21 patients (27 feet) with CMT were compared to those of 20 healthy controls. Calcaneal measurements included radius of curvature, sagittal posterior tuberosity-posterior facet angle, and tuberosity coronal rotation. Talar measurements included axial and sagittal body-neck declination angle, and coronal talar head rotation. Surface-mesh model analysis of the hindfoot was performed comparing the average of the CMT cohort to the controls using a CT analysis software (Disior Bonelogic 2.0). Means were compared with a t test (P < .05).

RESULTS

CMT patients had significantly less talar sagittal declination vs controls (17.8 vs 25.1 degrees; P < .05). Similarly, CMT patients had less talar head coronal rotation vs controls (30.8 vs 42.5 degrees; P < .001). The calcaneal radius of curvature in CMT patients was significantly smaller than controls (822.8 vs 2143.5 mm; P < .05). CMT sagittal posterior tuberosity-posterior facet angle was also significantly different from that of controls (60.3 vs 67.9 degrees respectively; P < .001).Surface-mesh model analysis demonstrated the largest differences in morphology at the navicular tuberosity, medial talar head, sustentaculum tali, and anterior process of the calcaneus.

CONCLUSION

This is the first study to quantify the morphologic differences in hindfoot osteology seen in CMT patients. Patients identified with osseous changes of the calcaneus, especially a smaller axial radius of curvature, may benefit from a 3-dimensional osteotomy for correction.

Functional outcome in patients with Charcot neuropathy with almost complete loss of talus treated by tibio-talo calcaneal nail: A cross-sectional study

INTRODUCTION

Tibio-talo-calcaneal (TTC) fusion is a successful surgery for Charcot neuropathy affecting the hindfoot. A case series of Charcot neuropathy is presented with almost complete loss affecting hindfoot treated with tibio-talo-calcaneal nail.

MATERIAL AND METHODS

Seven patients with Charcot neuropathy of the hindfoot having varying degrees of talus loss underwent tibio-talo-calcaneal nailing between January 2014 and Feb 2016 at a tertiary care hospital by a single surgeon. All the patients were type 3a as per Brodsky classification. Patients with active infection, fractures and avascular necrosis of talus was excluded from the study. The final outcome was measured using the AOFAS and FADI scores at the end of 2 years.

RESULTS

The mean duration of diabetes was 8.16 ± 3.12 years. Two patients (28.6%) had total and 5 (71.4%) patients had subtotal talus loss. Anterior approach was used in four, and lateral approach was used in three cases respectively. The talus was reconstructed by using the iliac crest or the graft from the distal fibula wherever appropriate. The average surgical duration was 93.28 ± 4.84 min. One patient had deep infection, 2 years after the surgery which was treated by implant removal and antibiotics. No patients had non-union. The pre-operative AOFAS scores improved from 32.2 ± 2.58 to 73.4 ± 3.36 at 2-year follow-up (p < 0.0001). Similarly, the pre-operative FADI scores were 31.74 ± 1.98 which improved to 65.94 ± 3.68 at the end of 2 years (p < 0.0001).

CONCLUSION

Retrograde tibio-talo-calcaneal nail is a good option for limb salvage in patients with severe talus loss with good functional outcome.

LEVEL OF EVIDENCE

Therapeutic IV.

Alignment of the hindfoot following total knee arthroplasty: A systematic review

BACKGROUND

There appears to be a close relationship between deformities at the knee joint and at the hindfoot in patients with knee osteoarthritis (OA). Despite this intrinsic link, there is a dearth of studies investigating alterations in hindfoot alignment following total knee arthroplasty (TKA) in patients with knee OA.

AIM

To evaluate changes in alignment of the hindfoot following TKA, foot and ankle clinical outcomes in terms of subjective clinical scoring tools following surgical intervention, and to analyse the level of evidence (LOE) and quality of evidence (QOE) of the included studies.

METHODS

MEDLINE, EMBASE and Cochrane Library databases were systematically reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting changes in the postoperative alignment of the hindfoot following TKA were included. The level and QOE were recorded and assessed.

RESULTS

Eleven studies with a total of 1142 patients (1358 knees) met the inclusion/ exclusion criteria. Six studies were of LOE II and 5 studies were of LOE III. Patients with preoperative varus knee deformity and valgus hindfoot deformity demonstrated improvement in hindfoot alignment post TKA. Patients with preoperative varus knee deformity and varus hindfoot deformity demonstrated no improvement in hindfoot alignment following TKA. Twelve different radiographic parameters were used to measure the alignment of the hindfoot across the included studies, with the tibio-calcaneal angle most frequently utilised (27.3%).

CONCLUSION

This systematic review demonstrated that the hindfoot may display compensatory changes in alignment following TKA in patients with knee OA. However, the marked heterogeneity between the included studies and poor QOE limits any meaningful cross sectional comparisons between studies. Further, well designed studies are necessary to determine the changes and outcomes of hindfoot alignment following TKA.

Expanding Indications of Primary Arthrodesis in Selected Individuals for Managing Complex Hindfoot Trauma During COVID-19 Pandemic

BACKGROUND

During the COVID-19 pandemic, public health measures to encourage social distancing have been implemented, including cancellation of outdoor activities, organized sports, and schools/colleges. Neglected hindfoot fractures have emerged as a consequence with increased frequency. Similarly, complex ankle and pilon fractures that require staged management, prolonged hospital stay, and soft-tissue care have emerged as a potential concern as prolonged exposure to healthcare setting adds to risk of acquiring as well as transmitting COVID-19 infection. The authors present their experience with expanding these indications for hindfoot arthrodesis as they encounter a greater number of neglected ankle and hindfoot trauma.

METHODS

This was a retrospective observational study of collected data from the trauma unit of our hospital. Inclusion criteria included all trauma classified by the AO/OTA as occurring at locations 43, and who underwent subtalar and ankle arthrodesis. This included distal tibia, malleolar, talus, and calcaneus fractures. These patients were followed up to at least 6 months till complete fracture union.

RESULTS

A total of 18 patients underwent arthrodesis of either the ankle or subtalar joint between March and October 2020. Mean age of patients undergoing arthrodesis of the hindfoot was 69.2 years (43-84 years). Indications for the procedure included Displaced and comminuted intra-articular distal tibia fractures in elderly (6 patients), Malunited ankle fractures (2 patients), Neglected Ankle fractures managed conservatively (3 patients), Calcaneus fractures (5 patients), and neglected Talus body fracture (2 patients). All patients were followed up to at least 6 months and everyone went onto successful painless union between 3 and 6 months of the arthrodesis procedure without any significant complications.

CONCLUSION

In summary, COVID-19 pandemic has led to a change in paradigm of trauma management and foot and ankle management is no different than other musculoskeletal trauma systems. The authors propose an expansion of indications for hindfoot arthrodesis in managing complex hindfoot trauma in pandemic situation.

Progressive Collapsing Foot Deformity: Should We Be Staging It Differently?

This article cursorily reviews the history of classification systems for pathologic flatfoot deformity in the adult and also critically reviews the recent introduction of a classification system intended to improve on the deficiencies of prior systems. The article concludes by offering suggestions for further work in evolving even more utilitarian systems for the staging and treatment of adult flatfoot disorder.

Current concepts in sinus tarsi syndrome: A scoping review

INTRODUCTION

Sinus tarsi syndrome is a relatively unknown condition presenting with pain and a feeling of instability. We aim to summarise evidence on the aetiology, diagnosis and treatment of the condition, whilst answering the question of whether the term should be used.

METHODS

Scoping review following the methodological frameworks of Arksey and O'Malley, Levac and Peters. The review protocol is registered with the Open Science Framework: (https://osf.io/wj6ct/?view_only=59445d344ec34b6fab640d2fa7a83943).

RESULTS

In total, 605 studies were identified, 31 of which met selection criteria. Sinus tarsi syndrome is used to describe a range of distinct underlying pathologies. MRI and arthrography show non-specific abnormalities in patients and identifying underlying pathologies is challenging.

DISCUSSION

The distinct range of underlying pathologies makes identifying specific imaging abnormalities and optimal treatments difficult. Further research in determining optimal treatments for specific pathologies and investigating the efficacy of conservative treatment must be conducted, before we can justify a more specific diagnosis.

Principles of Triple Arthrodesis and Limited Arthrodesis in the Cavus Foot

Cavus foot is a complex podiatric deformity that requires precise and in-depth work-up through an objective, physical, and radiographic examination. The goal of surgical treatment is to eliminate pain while establishing a plantigrade foot structure. Triple arthrodesis has proven to be an effective surgical procedure for treatment of moderate to severe rearfoot deformity with or without the presence of rearfoot arthritic changes. The foot and ankle surgeon must always be aware that no two cavus deformity cases are alike, therefore one may require additional surgical procedures including soft tissue balancing, joint-sparing osteotomies, and/or supplementary arthrodesing procedures.

The use of circular frame external fixation in the treatment of ankle/hindfoot Charcot Neuroarthropathy

Charcot Neuroarthropathy (CN) of the ankle/hindfoot is a devastating condition that results in a loss of alignment, bony malleolar protrusions and frequently leads to ulceration, infection, and amputation. Major limb amputations in this patient population has a 5-year mortality rate approximating 39%-68%. The treatment goal for CN of the ankle/hindfoot is to provide stability with a plantigrade foot that is infection free, shoeable and allows independent weight bearing. The use of a circular frame external fixator is often required when treating patients with CN of the ankle/hindfoot because they often present late with deformity, soft tissue compromise and infection which are contraindications to primary internal fixation. These patients require urgent surgical attention to salvage the limb or risk amputation. In this narrative review article we will discuss the indications, management options, surgical technique, evidence and describe our experience in the use of circular frame external fixation in patients with ankle/hindfoot Charcot Neuroarthropathy.

Reliability testing of the heel marker in three-dimensional gait analysis

INTRODUCTION

In three-dimensional gait analysis, anatomical axes are defined by and therefore sensitive to marker placement. Previous analysis of the Oxford Foot Model (OFM) has suggested that the axes of the hindfoot are most sensitive to marker placement on the posterior aspect of the heel. Since other multi-segment foot models also use a similar marker, it is important to find methods to place this as accurately as possible. The aim of this pilot study was to test two different 'jigs' (anatomical alignment devices) against eyeball marker placement to improve reliability of heel marker placement and calculation of hindfoot angles using the OFM.

METHODS

Two jigs were designed using three-dimensional printing: a ratio caliper and heel mould. OFM kinematics were collected for ten healthy adults; intra-tester and inter-tester repeatability of hindfoot marker placement were assessed using both an experienced and inexperienced gait analyst for 5 clinically relevant variables.

RESULTS

For 3 out of 5 variables the intra-tester and inter-tester variability was below 2 degrees for all methods of marker placement. The ratio caliper had the lowest intra-tester variability for the experienced gait analyst in all 5 variables and for the inexperienced gait analyst in 4 out of 5 variables. However for inter-tester variability, the ratio caliper was only lower than the eyeball method in 2 out of the 5 variables. The mould produced the worst results for 3 of the 5 variables, and was particularly prone to variability when assessing average hindfoot rotation, making it the least reliable method overall.

CONCLUSIONS

The use of the ratio caliper may improve intra-tester variability, but does not seem superior to the eyeball method of marker placement for inter-tester variability. The use of a heel mould is discouraged.

Magnetic resonance imaging features of intra-articular tenosynovial giant cell tumor in children

BACKGROUND

Magnetic resonance imaging (MRI) plays a critical role in disease characterization of intra-articular tenosynovial giant cell tumor.

OBJECTIVE

To characterize the MRI features of intra-articular tenosynovial giant cell tumor in children with respect to disease subtype and anatomical location.

MATERIALS AND METHODS

This retrospective study included children with tenosynovial giant cell tumor who underwent preoperative MRI between January 2006 and May 2020. Two radiologists reviewed each examination to determine disease subtype, signal intensities and the presence of an effusion, osseous changes, chondromalacia, juxtacapsular disease and concomitant joint involvement. Fisher exact, Mann-Whitney U, and Kruskal-Wallis H tests were used to compare findings between subtypes and locations.

RESULTS

Twenty-four children (16 girls, 8 boys; mean age: 13.1±3.8 years) with 19 knee and 5 ankle-hindfoot tenosynovial giant cell tumor had either diffuse (n=15) or localized (n=9) disease. An effusion (P=0.004) was significantly more common with diffuse than localized disease. There was no significant difference in MRI signal (P-range: 0.09-1) or other imaging findings (P-range: 0.12-0.67) between subtypes. Children with knee involvement were significantly more likely to present with diffuse disease while those with ankle-hindfoot involvement all presented with focal disease (P=0.004). Juxtacapsular (n=4) and concomitant proximal tibiofibular joint involvement (n=5) were observed with diffuse disease in the knee. Erosions (P=0.01) were significantly more common in the ankle than in the knee.

CONCLUSION

In our study, diffuse tenosynovial giant cell tumor was more common than localized disease, particularly in the knee where juxtacapsular and concomitant proximal tibiofibular joint disease can occur.

Charcot hindfoot deformity reconstruction using a hindfoot nail- surgical technique

Various techniques of reconstruction of deformed Charcot hindfoot using different internal fixation devices have been described in the literature. We present our surgical technique using specific principles that has resulted in improved outcomes to allow correction of deformity, obtain stability and allow progression to weightbearing in orthotic shoes. We describe our preoperative evaluation, planning and surgical timing. We also hope to share some technical pearls and details on the finer points to achieve a satisfactory correction and reduce the learning curve.

Healthy ankle and hindfoot kinematics during gait: Sex differences, asymmetry and coupled motion revealed through dynamic biplane radiography

The aims of this study were to compare male versus female and dominant versus non-dominant kinematics in the ankle and hindfoot, and to characterize coupled motion between the subtalar and tibiotalar joints during the support phase of gait. Twenty healthy adults walked on a laboratory walkway while synchronized biplane radiographs of the ankle and hindfoot were collected at 100 frames/s. A validated tracking technique was used to measure tibiotalar and subtalar kinematics. Differences between male and female range of motion (ROM) were observed only in tibiotalar (AP and ML) and subtalar (ML) translation (all differences<1 mm and all p < 0.04). Statistical parametric mapping identified differences between kinematics waveforms of males and females in tibiotalar translation (AP and ML) and eversion, and subtalar ML translation. No differences between dominant and non-dominant sides were observed in ROM or kinematics waveforms. The average absolute side-to-side difference in the kinematics waveforms was 4.1° and 1.5 mm or less for all rotations and translations, respectively. Tibiotalar plantarflexion was coupled to subtalar inversion and eversion during the impact and push-off phases of stance (r = 0.90 and r = 0.87, respectively). This data may serve as a guide for evaluating ankle kinematics waveforms, ROM, symmetry, and restoration of healthy coupled motion after surgical intervention or rehabilitation. The observed kinematics differences between males and females may predispose females to higher rates of ankle and knee injury and suggest sex-dependent ankle reconstruction techniques may be beneficial.

Midfoot and ankle motion during heel rise and gait are related in people with diabetes and peripheral neuropathy

BACKGROUND

Midfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy (DMPN) is associated with midfoot deformity and increased plantar pressures during gait. If midfoot and ankle motion during heel rise and push-off of gait have similar mechanics, heel rise performance could be a clinically feasible way to identify abnormal midfoot and ankle function during gait.

RESEARCH QUESTION

Is midfoot and ankle joint motion during a heel rise associated with midfoot and ankle motion at push-off during gait in people with DMPN?

METHODS

Sixty adults with DMPN completed double-limb heel rise, single-limb heel rise, and walking. A modified Oxford multi-segment foot model (forefoot, hindfoot, shank) was used to analyze midfoot (forefoot on hindfoot) and ankle (hindfoot on shank) sagittal angle during heel rise and gait. Pearson correlation was used to test the relationship between heel rise and gait kinematic variables (n = 60). Additionally, we classified 60 participants into two subgroups based on midfoot and ankle position at peak heel rise: midfoot and ankle dorsiflexed (dorsiflexed; n = 23) and midfoot and ankle plantarflexed (plantarflexed; n = 20). Movement trajectories of midfoot and ankle motion during single-limb heel rise and gait of the subgroups were examined.

RESULTS

Peak double-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.49 and r = 0.40, respectively). Peak single-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.63 and r = 0.54, respectively). The dorsiflexed subgroup, identified by heel rise performance showed greater midfoot and ankle dorsiflexion during gait compared to the plantarflexed subgroup (mean difference between subgroups: midfoot 3°, ankle 3°).

SIGNIFICANCE

People with DMPN who fail to plantarflex the midfoot and ankle during heel rise have difficulty plantarflexing the midfoot and ankle during gait. Utilizing a heel rise task may help identify midfoot and ankle dysfunction associated with gait in people with DMPN.

Pes cavovarus in Charcot-Marie-Tooth compared to the idiopathic cavovarus foot: A preliminary weightbearing CT analysis

BACKGROUND

Pes cavovarus is a foot deformity that can be idiopathic (I-PC) or acquired secondary to other pathology. Charcot-Marie-Tooth disease (CMT) is the most common adult cause for acquired pes cavovarus deformity (CMT-PC). The foot morphology of these distinct patient groups has not been previously investigated. The aim of this study was to assess if morphological differences exist between CMT-PC, I-PC and normal feet (controls) using weightbearing computed tomography (WBCT).

METHODS

A retrospective analysis of WBCT scans performed between May 2013 and June 2017 was undertaken. WBCT scans from 17 CMT-PC, 17 I-PC and 17 healthy normally-aligned control feet (age-, side-, sex- and body mass index-matched) identified from a prospectively collected database, were analysed. Eight 2-dimensional (2D) and three 3-dimensional (3D) measurements were undertaken for each foot and mean values in the three groups were compared using one-way ANOVA with the Bonferroni correction.

RESULTS

Significant differences were observed between CMT-PC or I-PC and controls (p<0.05). Two-dimensional measurements were similar in CMT-PC and I-PC, except for forefoot arch angle (p=0.04). 3D measurements (foot and ankle offset, calcaneal offset and hindfoot alignment angle) demonstrated that CMT-PC exhibited more severe hindfoot varus malalignment than I-PC (p=0.03, 0.04 and 0.02 respectively).

CONCLUSIONS

CMT-related cavovarus and idiopathic cavovarus feet are morphologically different from healthy feet, and CMT feet exhibit increased forefoot supination and hindfoot malalignment compared to idiopathic forms. The use of novel three-dimensional analysis may help highlight subtle structural differences in patients with similar foot morphology but aetiologically different pathology.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

3D imaging for hindfoot alignment assessment: a comparative study between non-weight-bearing MRI and weight-bearing CT

PURPOSE

The authors compared measurements of hindfoot alignment on MR imaging with weight-bearing CT (WB-CT) to establish the degree of correlation. Forty-seven feet in 44 patients had weight-bearing CT and MRI studies performed on the same day.

MATERIALS AND METHODS

Hindfoot alignment on MRI was assessed by two radiologists who calculated tibiocalcaneal angle (TCA) and calcaneofibular ligament angle (CFLA). On WB-CT, foot ankle offset (FAO), calcaneal offset (CO) and hindfoot angle (HA) were assessed by a senior Foot and Ankle Surgeon using dedicated software. Pearson correlation coefficient was used to evaluate the correlation between these measurements.

RESULTS

The study group comprised 27 males and 17 females with a mean age of 45 years (range 13-79 years). A statistically significant positive correlation was identified between TCA on MRI and all measurements of hindfoot alignment on WB-CT (p = 0.001-0.005). The CFLA on MRI only had significant correlation with CO on WB-CT (p = 0.03). A significant negative correlation was observed between both MRI parameters (p < 0.001).

CONCLUSION

A highly significant correlation between tibiocalcaneal angle on non-weight-bearing ankle MR imaging and hindfoot alignment measurements on weight-bearing CT was identified.

Induced Membrane Technique (Masquelet) for Bone Defects in the Distal Tibia, Foot, and Ankle: Systematic Review, Case Presentations, Tips, and Techniques

Bone defects to the distal tibia, foot, and ankle can be challenging to reconstruct. The induced membrane (Masquelet) technique has become an established method of repair for challenging areas of bone loss. It has been applied in acute open fractures, chronic nonunion, osteomyelitis, and gout erosion. This article presents a systematic review of distal tibia, foot, and ankle results using the Masquelet procedure, which should be considered in cases of challenging critical bone loss. Further work is needed to present large studies of the procedure on foot and ankle patients to consolidate current knowledge.

[Etiology, pathogenesis, clinical features, diagnostics and conservative treatment of adult flatfoot]

BACKGROUND

On average, one in six adults is affected by an acquired flatfoot. This foot deformity is characterized by its progression of stages and in 10% of cases causes complaints that require treatment. Untreated, the loss of walking ability may result in the final stage. Correct staging is crucial to being able to offer a specific course of therapy including a wide spectrum of conservative and operative treatments.

MATERIAL AND METHODS

This review is based on pertinent publications retrieved from a selective search in PubMed and Medline and on the authors' clinical experience.

DIAGNOSTICS

The loss of function of static (spring ligament complex) and dynamic (tibialis posterior tendon) stabilizers causes the characteristic deformity with loss of the medial arch, hind foot valgus and forefoot abduction. In the late stage, severe secondary osteoarthritis in upper and lower ankle joints occurs and impedes walking ability. The essential physical examination is supplemented by weight-bearing dorsoplantar and lateral radiographs, which provide further information about axial malalignment (Meary's angle, Kite's angle). The long axis hind foot view allows analysis of the hindfoot valgus. MRI provides further information about the integrity of the tibialis posterior tendon, spring ligament complex and cartilage damage.

THERAPY

The therapy aims to reduce pain, regain function and avoid development of secondary osteoarthritis and degenerative tendon disorders. Progress of the deformity should be stopped. Therefore, the main aspects of the deformity-loss of medial arch, hindfoot valgus and forefoot abduction should be addressed and corrected. In the acute phase, tendovaginitis of the tibialis posterior tendon can be treated sufficiently by anti-inflammatory measures, relieving mechanical loads on the tendon and muscle and physiotherapy.

ACR Appropriateness Criteria® Chronic Foot Pain

Chronic foot pain is a frequent clinical complaint, which can significantly impact the quality of live in some individuals. These guidelines define best practices with regards to requisition of imaging studies based on specific clinical scenarios, which have been grouped into different variants. Each variant is accompanied by a brief description of the usefulness, advantages, and limitations of different imaging modalities. The present narrative is the result of an exhaustive assessment of the available literature and a thorough review process by a panel of experts on Musculoskeletal Imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Incomplete resection increases the risk of local recurrence and negatively affects functional outcome in patients with tenosynovial giant cell tumor of the hindfoot

BACKGROUND

Diffuse tenosynovial giant cell tumors (TGCT) are more likely to occur in the hindfoot and tend to recur after surgical excision. We performed a pooled analysis of hindfoot TGCT cases to identify factors associated with local recurrence and functional outcomes.

METHODS

We retrospectively reviewed medical records of 33 patients diagnosed with TGCT (15, localized cases; 18 diffused cases) of the hindfoot between 1998 and 2017. Median follow-up was 32 months. Multivariable Cox proportional hazards regression analysis was conducted to estimate the hazard ratios for risk factors for local failure. Generalized linear regression models were used to assess whether resection status, tumor size, tumor type or bone involvement correlated with the Musculoskeletal Tumor Society (MSTS) score.

RESULTS

Local failure was reported in 30% (10/33) patients. Multivariable analysis showed that macroscopically incomplete resection was the only independent prognostic factor for poor local failure-free survival (P=.001). Incomplete resection significantly decreased MSTS score and negatively affected functional outcome (P=.047).

CONCLUSIONS

Incomplete resection increases the risk of local recurrence and negatively affects functional outcome in patients with TGCT of the hindfoot.

Hindfoot blast injuries caused by improvised explosive devices: long-term functional assessment in French military personnel

PURPOSE

The chosen treatment and long-term evaluation of hindfoot blast injuries are not well-represented in the literature. The first objective of this retrospective study was to evaluate functional outcomes in French service personnel who had sustained such injuries caused by improvised explosive devices. The second objective was to compare the results for patients who had amputations with those who did not. The hypothesis was that amputee recovered better function.

METHODS

Long-term functional evaluations were carried out using the American Orthopaedic Foot and Ankle Society scale (AOFAS), the Foot and Ankle Ability Measure (FAAM), and the Short Form 12 health survey (SF-12).

RESULTS

Eight servicemen with ten hindfoot blast injuries were reviewed at a mean follow-up time of seven years. Primary management was always conservative although half of the patients required late amputation for chronic pain. The patients who underwent amputation reported significantly lower levels of pain than those who did not have an amputation, with higher FAAM and SF-12 scores.

CONCLUSION

In this series, long-term functional results appear better in the amputated group.

An automated method for defining anatomic coordinate systems in the hindfoot

The absence of a standardized method for defining hindfoot bone coordinate systems makes it difficult to compare kinematics results from different research studies. The purpose of this study was to develop a reliable and robust procedure for defining anatomical coordinate systems for the talus and calcaneus. Four methods were evaluated based upon their anatomic consistency across subjects, repeatability, and their correspondence to functional axes of rotation. The four systems consisted of: 1) interactively identified bony landmarks, 2) a principal component analysis, 3) automatically identified bony landmarks, and 4) translating the tibial coordinate system to the hindfoot bones. The four systems were evaluated on 40 tali and 40 calcanei. The functional axes of rotation were determined using dynamic biplane radiography to image the hindfoot during gait. Systems 2 and 3 were the most repeatable and consistent due to the lack of operator intervention when defining coordinate systems. None of the coordinate systems corresponded well to functional axes of rotation during gait. System 3 is recommended over System 2 because it more closely mimics established bone angles measured clinically, especially for the calcaneus. This study presents an automated method for defining anatomic coordinate systems in the talus and calcaneus that does not rely on manual placement of markers or fitting of spheres to the bone surfaces which are less reliable due to operator-dependent measurements. Using this automated method will make it easier to compare hindfoot kinematics results across research studies.

Intraobserver and interobserver reliability of cone beam weightbearing semi-automatic three-dimensional measurements in symptomatic pes cavovarus

INTRODUCTION

Pes cavovarus is a three-dimensional (3D) foot deformity. New 3D semi-automatic measurements utilising weightbearing computerised topography (WBCT) images have recently been proposed to assess hindfoot alignment, but reliability in pes cavovarus has never been investigated. The aim of this study was to assess intraobserver and interobserver reliability of the foot ankle offset (FAO), calcaneal offset (CO) and hindfoot alignment angle (HAA) in pes cavovarus.

METHODS

Anonymised WBCT datasets from 51 feet (17 Charcot-Marie-Tooth related cavovarus, 17 idiopathic cavovarus and 17 controls) were retrospectively reviewed. Three observers (two senior foot and ankle fellows and one orthopaedic resident) independently measured FAO, CO and HAA using dedicated software, with measurements repeated two weeks apart. Subgroup analysis was performed to assess whether aetiology or severity of varus deformity and level of seniority affected reliability.

RESULTS

Mean values for intra and interobserver reliability for FAO (r=0.98; ICC: 0.99), CO (r=0.97; ICC: 0.98) and HAA measurements (r=0.97; ICC: 0.98) were excellent. Subgroup analyses showed that FAO, CO and HAA's intra (r/ρ range, 0.77-0.95) and interobserver (ICC range, 0.88-0.98) reliability remained excellent in patients with Charcot-Marie-Tooth related cavovarus, idiopathic pes cavovarus and normal feet, regardless of the severity of deformity. No difference was found in FAO, CO and HAA mean values from three observers (p>0.05 in all cases).

DISCUSSION

This study demonstrates that 3D semi-automatic measurements of WBCT images have excellent intra and interobserver reliability in the assessment of hindfoot alignment in pes cavovarus. Aetiology and severity of deformity, and level of seniority do not affect reliability of these measurements.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Treatment of Ankle and Hindfoot Charcot Arthropathy

It is now well accepted that diabetic patients with clinically and radiographically nonplantigrade Charcot foot arthropathy are best managed with correction of the acquired deformity. Several investigations have demonstrated a high probability for a favorable clinical outcome when the deformity is in the midfoot. Unstable deformity at the subtalar or ankle joints portends a far worse clinical outcome. The goal of this discussion was to describe the author's approach to this highly challenging clinical problem.

Correlation between the accessory anterolateral talar facet, bone marrow edema, and tarsal coalitions

OBJECTIVE

The purposes of this study was to determine the prevalence of the accessory anterolateral talar facet (AALTF); to evaluate the relationship between AALTF, focal abutting bone marrow edema (FABME), and sinus tarsi edema; and to study the prevalence of tarsal coalitions in patients with the AALTF utilizing ankle MR images.

MATERIALS AND METHODS

5-T ankle MR images were reviewed for the presence of AALTF, FABME, sinus tarsi edema, tarsal coalition, and location and type of coalition (cartilaginous, fibrous, and osseous). Multivariate analysis was performed to examine the correlation between AALTF and the other variables.

RESULTS

Three hundred ninety-one consecutive patients were included (age range 5-86 years; mean age 45 years). An AALTF was present in 3.6% (14/391) of patients. The AALTF prevalence was 2% in women and 6.6% in men. There was a significantly association between AALTF and FABME (9/14, p < 0.05), sinus tarsi edema (13/14, p < 0.05), and tarsal coalition (4/14, p < 0.05).

CONCLUSION

AALTF is relatively often detected on MRI of the ankle and significantly associated with BME, sinus tarsi edema, and subtalar coalition. Patients with a tarsal coalition should be evaluated for the concurrent presence of an AALTF.

The horizontal calcaneofibular ligament: a sign of hindfoot valgus on ankle MRI

OBJECTIVE

Hindfoot valgus malalignment has been assessed on coronal MRI by the measurement of the tibio-calcaneal (TC) angle and apparent moment arm (AMA). This study aimed to determine if the calcaneofibular ligament (CFL) angle could be used as a further marker of hindfoot valgus malalignment on routine non-weight-bearing ankle MRI.

MATERIAL AND METHODS

One hundred ninety-five consecutive 3-T ankle MRI studies were identified from the hospital PACS system. The TC and CFL angles could be measured in 155 cases (78%), and the AMA on 153 cases.

RESULTS

The study group comprised 56 males and 72 females with a mean age of 46 years (range 4-89 years). In 27 patients, both ankles had been imaged. The Pearson correlation between the TC and CFL angles was -0.43, with a corresponding p value of 0.001 indicating a strong negative correlation between the TC and CFL angles. The CFL angle was significantly lower in those with hindfoot valgus (113 ± 14) compared with those without (123° ± 15°) (p = 0.001). The optimal cut-off point of the CFL angle for hindfoot valgus was ≤119°, with a sensitivity and specificity of 66% and 63% respectively. The Pearson correlation between the CFL angle and AMA was -0.10, with a corresponding p value of 0.21 indicating a weak negative correlation that did not reach statistical significance.

CONCLUSION

Hindfoot valgus as estimated by the increased TC angle on coronal non-weight-bearing ankle MRI is associated with a reduced CFL angle on sagittal MR images, but is not associated with AMA. Therefore, a horizontal orientation of the CFL on sagittal MR images may be a further useful sign of hindfoot valgus.

Three-dimensional kinematic change of hindfoot during full weightbearing in standing: an analysis using upright computed tomography and 3D-3D surface registration

Background

Weightbearing of the hindfoot affects positional changes of the ankle joint and subtalar joint (ankle-joint complex [AJC]). However, it is difficult to assess the kinematic changes in the hindfoot in a natural full weightbearing condition using conventional CT or cone beam computed tomography (CT) due to limitations of acquiring foot images under a physiological weightbearing condition using those imaging modalities. Analysis of AJC kinematics using fluoroscopy and 2D-3D registration technique requires data on the number of steps and amount of time to build and match the bones. This study aimed to analyze the effect of full weightbearing on hindfoot motion when standing using upright CT and 3D-3D surface registration.

Methods

Forty-eight AJCs of 24 asymptomatic volunteers (13 women, 11 men) were examined under no weightbearing, 50% weightbearing, and single leg full weightbearing conditions while standing. The CT images were acquired from the distal femur to the whole foot using a 320-row upright CT scanner. The condition of each weightbearing stance was measured using a pressure mat. Bone-to-bone rotations of the talus relative to the tibia and calcaneus relative to the talus were evaluated using the surface registration technique. Image quality of the CT and intra- and interobserver reliabilities of the rotation angle were also evaluated.

Results

All CT images were excellent or good quality and the intra- and interobserver correlation coefficients for the angle were 0.996 and 0.995, respectively. The motion of the ankle joint and subtalar joint under 50% and 100% weightbearing were as follows (in degrees); the talus plantarflexed (5.1 ± 4.5 and 6.8 ± 4.8), inverted (1.3 ± 1.4 and 2.0 ± 1.6), and internally rotated (2.4 ± 4.2 and 4.3 ± 4.6) relative to the tibia, and the calcaneus dorsiflexed (2.8 ± 1.4 and 3.8 ± 1.7), everted (5.3 ± 2.6 and 8.0 ± 3.6), and externally rotated (3.0 ± 2.0 and 4.1 ± 2.4) relative to the talus, respectively.

Conclusions

The effect of weightbearing was clearly identified using an upright CT and the 3D-3D registration technique. Three-dimensional kinematics under static full weightbearing were opposite between the ankle and subtalar joints on their respective axes.

Impingement syndromes of the ankle and hindfoot

Ankle impingement refers to a chronic painful mechanical limitation of ankle motion caused by soft-tissue or osseous abnormality affecting the tibiotalar joint or extraarticular soft tissues. Impingement can be associated with a prior single traumatic event or repetitive microtrauma, often in an adolescent with anatomical predisposition. Impingement syndromes at the tibiotalar joint can be subdivided into anterior, anterolateral, anteromedial, posterior or posteromedial. Extraarticular impingement can consist of talocalcaneal or subfibular impingement. Impingement syndromes are just one possible etiology of persistent ankle pain, and although the diagnosis is often made or suspected clinically, the radiologist might be the first person to raise the possibility of the diagnosis or be called upon to provide support for the clinically suspected diagnosis. In this article I review the etiology, imaging findings and current treatment associated with these conditions.

The influence of selective arthrodesis on three-dimensional range of motion of hindfoot joint: A cadaveric study

BACKGROUND

The purpose of this study was to measure the three-dimensional range of motion of adjacent, unfused joint or joints after different arthrodesis of hindfoot.

METHODS

Sixteen fresh frozen cadaver feet were immobilized in the non-weight bearing position. The three-dimensional coordinates of markers in tarsal were measured in six directions (involving dorsiflexion-plantarflexion, eversion-inversion, and adduction-abduction) before and after single (involving subtalar joint, talonavicular joint, and calcaneocuboid joint) and double (talonavicular and calcaneocuboid joints) arthrodesis with a three-dimensional coordinate instrument. The range of motion of the joint was calculated with the least square method and matrix transformation.

FINDINGS

We found that the range of motion of joints in all direction was reduced significantly after any combination of selective arthrodesis (all p < 0.001). After arthrodesis of the subtalar joint, the motion of talonavicular joint was reduced by 72%, and that of calcaneocuboid joint by 36%. After arthrodesis of talonavicular joint, the motion of subtalar joint was diminished by 36%, and that of calcaneocuboid joint by 51%. After arthrodesis of calcaneocuboid joint, the motion of subtalar joint was decreased by 21%, and that of talonavicular joint by 42%. After double arthrodesis, the motion of subtalar joint was reduced by 62%.

INTERPRETATION

In single arthrodesis, subtalar arthrodesis had the greatest effect on the motion of unfused joints, and the least was the calcaneocuboid arthrodesis. The motion of the subtalar joint was eliminated more than half after double arthrodesis. The data provide a biomechanical rationale to ascertain the clinical implication of the arthrodesis.