Subtalar arthrodesis alignment: the effect on ankle biomechanics

Optimizing Subtalar Arthrodesis: A Human Cadaveric Evaluation of a Novel Partially-Threaded Screw Combination in the Delta Configuration

Background and Objectives: Despite the established role of subtalar joint arthrodesis (SJA) for treatment of subtalar osteoarthritis, achieving bone union remains challenging, with up to 46% non-union rates. Adequate compression and stable fixation are crucial for successful outcomes, with internal screw fixation being the gold standard for SJA. The delta configuration, featuring highly divergent screws, offers stability, however, it can result in hardware irritation in 20-30% of patients. Solutions to solve this complication include cannulated compression screw (CCS) countersinking or cannulated compression headless screw (CCHS) application. The aim of this biomechanical study was to investigate the stability of a delta configuration for SJA utilizing either a combination of a posterior CCHS and an anterior CCS or a standard two-CCS combination. Materials and Methods: Twelve paired human cadaveric lower legs were assigned pairwise to two groups for SJA using either two CCSs (Group 1) or one posterior CCHS and one anterior CCS (Group 2). All specimens were tested under progressively increasing cyclic loading to failure, with monitoring of the talocalcaneal movements via motion tracking. Results: Initial stiffness did not differ significantly between the groups, p = 0.949. Talocalcaneal movements in terms of varus-valgus deformation and internal-external rotation were significantly bigger in Group 1 versus Group 2, p ≤ 0.026. Number of cycles until reaching 5° varus-valgus deformation was significantly higher in Group 2 versus Group 1, p = 0.029. Conclusions: A delta-configuration SJA utilizing a posterior CCHS and an anterior CCS is biomechanically superior versus a standard configuration with two CCSs. Clinically, the use of a posterior CCHS could prevent protrusion of the hardware in the heel, while an anterior CCS could facilitate less surgical time and thus less complication rates.

Hindfoot Arthrodeses and the Order of Joint Fixation Influence Tibiotalar Kinematics During Simulated Stance

BACKGROUND

Although hindfoot arthrodeses relieve pain and correct deformity, they have been associated with progressive tibiotalar degeneration. The objective was to quantify changes in tibiotalar kinematics after hindfoot arthrodeses, both isolated subtalar and talonavicular, as well as double arthrodesis, and to determine if the order of joint fixation affects tibiotalar kinematics.

METHODS

Hindfoot arthrodeses were performed in 14 cadaveric mid-tibia specimens. Specimens randomly received isolated fixation of the subtalar or talonavicular joint first, followed by fixation of the remaining joint for the double arthrodesis. A 6-degree-of-freedom robot sequentially simulated the stance phase of level walking for intact, isolated, and double arthrodesis conditions. Tibiotalar kinematic changes were compared for the intact and arthrodesis conditions. A subsequent analysis assessed the effect of the joint fixation order on tibiotalar kinematics.

RESULTS

Isolated and double hindfoot arthrodeses increased tibiotalar plantarflexion, inversion, and internal rotation during late stance. Tibiotalar kinematics changes occurring after isolated arthrodesis remained consistent after the double arthrodesis for both the subtalar- and talonavicular-first conditions. The order of joint fixation influenced tibiotalar kinematics through some portions of stance, where the talonavicular-first double arthrodesis increased tibiotalar plantarflexion, eversion, and internal rotation compared to the subtalar-first double.

CONCLUSION

Tibiotalar kinematics were modestly altered for all conditions, both isolated and double hindfoot arthrodeses. Changes in tibiotalar kinematics were consistent from the isolated to the double arthrodesis conditions and varied depending on which isolated hindfoot arthrodesis was performed first. Further research is needed to assess the clinical implications of the observed changes in tibiotalar kinematics, particularly as it pertains to the development of adjacent joint arthritis.

CLINICAL RELEVANCE

These findings may correlate with clinical research that has cited hindfoot arthrodesis as a risk factor for adjacent tibiotalar arthritis. Once either the subtalar or talonavicular joint is fused, avoiding the arthrodesis of the second joint may not necessarily protect the tibiotalar joint.

Cadaveric Gait Simulation of the Effect of Subtalar Arthrodesis on Total Ankle Replacement Kinematics

BACKGROUND

Patients undergoing total ankle replacement (TAR) often have symptomatic adjacent joint arthritis and deformity. Subtalar arthrodesis can effectively address a degenerative and/or malaligned hindfoot, but there is concern that it places abnormal stresses on the TAR and adjacent joints of the foot, potentially leading to early TAR failure. This study hypothesized that ankle and talonavicular joint kinematics would be altered after subtalar arthrodesis in the setting of TAR.

METHODS

Thirteen mid-tibia cadaveric specimens with neutral alignment were tested in a robotic gait simulator. To simulate gait, each specimen was secured to a static mounting fixture about a 6-degree of freedom robotic platform, and a force plate moves relative to the stationary specimen based on standardized gait parameters. Specimens were tested sequentially in TAR and TAR with subtalar arthrodesis (TAR-ST_fuse). Kinematics and range of motion of the ankle and talonavicular joint were compared between TAR and TAR-ST_fuse.

RESULTS

There were significant differences in kinematics and range of motion between TAR and TAR-ST_fuse groups. At the ankle joint, TAR-ST_fuse had less internal rotation in early-mid stance (P < .05), with decreased range of motion in the sagittal (-2.7 degrees, P = .008) and axial (-1.8 degrees, P = .002) planes in early stance, and increased range of motion in the coronal plane in middle (+1.2 degrees, P < .001) and late (+2.5 degrees, P = .012) stance. At the talonavicular joint, there were significant differences in axial and coronal kinematics in early and late stance (P < .05). Subtalar arthrodesis resulted in significantly decreased talonavicular range of motion in all planes in early and late stance (P < .003).

CONCLUSION

In ankles implanted with the TAR design used in this study, kinematics of the ankle and talonavicular joint were found to be altered after subtalar arthrodesis. Aberrant motion may reflect altered contact mechanics at the prosthesis and increased stress at the bone-implant interface, and affect the progression of adjacent joint arthritis in the talonavicular joint.

CLINICAL RELEVANCE

These findings may provide a correlate to clinical studies that have cited hindfoot arthrodesis as a risk factor for TAR failure.

Calcaneal Reconstruction With Free Deep Circumflex Iliac Artery Osseocutaneous Flap Following Aggressive Benign Bone Tumor Resection

BACKGROUND

Advances in limb-salvage techniques have made total calcanectomy and primary reconstruction possible in managing calcaneal aggressive benign tumors and selected cases of intraosseous malignant tumors. However, there is still no consensus on the operative approach, oncologic margin, and the best reconstruction method to date. These 2 cases describe our experience in calcaneal reconstruction with the free deep circumflex iliac artery (DCIA) osseocutaneous flap in benign aggressive calcaneal tumors.

METHODS

We reported 2 consecutive male and female patients, with an average age of 25 years (age 19 and 31, respectively), who underwent total calcanectomy and primary calcaneal reconstruction with the free DCIA osseocutaneous flaps for calcaneal chondroblastoma and giant cell tumor. A marginal resection of the entire calcaneus through the subtalar and calcaneocuboid joints (intra-articular approach) was performed in the first case and a wide local resection leaving 1 cm normal calcaneal bone margin anterosuperiorly (intraosseous approach) was performed in the second case.

RESULTS

The follow-up period averaged 48 months. Negative oncologic margins were achieved in both cases. The first case was complicated with venous thrombosis; however, the graft remained viable after emergency reexploration. Normal foot function was restored with good solid osseous union and bony hypertrophy observed. Both patients achieved good short-term functional and aesthetic outcomes with no donor site pain or disability. No local recurrence was reported either.

CONCLUSION

Primary calcaneal reconstruction with the free DCIA osseocutaneous flap can lead to good short-term functional and aesthetic outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

Outcomes and Complications of Open vs Posterior Arthroscopic Subtalar Arthrodesis: A Prospective Randomized Controlled Multicenter Study

BACKGROUND

Open subtalar arthrodesis is the standard treatment for subtalar arthritis. Posterior arthroscopic subtalar arthrodesis (PASTA) has recently gained increasing popularity due to a shorter recovery time and better cosmesis. However, studies comparing outcomes and complications between these 2 techniques are limited.

METHODS

In total, 56 patients with subtalar joint arthritis were prospectively randomized to 2 parallel groups to receive either PASTA (n = 28 patients) or open subtalar arthrodesis (n = 28 patients). The minimum follow-up period was 12 months. Primary outcome was union rate confirmed on postoperative computed tomography (CT) scan. Secondary outcomes were union time; visual analog scale (VAS), Short Form-36 (SF-36), and Foot and Ankle Ability Measure (FAAM) scores; tourniquet time; and complications.

RESULTS

Union time (9.4 vs 12.8 weeks) and recovery time (time to return to activities of daily living [8.4 vs 10.8 weeks], work [10.6 vs 12.9 weeks], and sports [24.9 vs 32.7 weeks]) were significantly shorter with PASTA than with the open technique (P < .05 all). Both techniques led to significant improvements in all functional outcomes (FAAM, SF-36, and VAS scores; P < .01 all); however, there was no significant difference between the techniques in these outcomes (P > .05 all). Other outcomes, including tourniquet time (55.8 vs 67.2 min), union rate (96.3% vs 100%), and complication rate, were not significantly different between the techniques.

CONCLUSION

Both open and PASTA techniques led to significant improvements in pain and function in patients with isolated subtalar joint arthritis. Although short-term functional outcomes and complication rates were not significantly different between the techniques, the PASTA technique was better at shortening the union and recovery times.

LEVEL OF EVIDENCE

Level I, prospective multicenter randomized controlled trial.

[Joint arthrodesis in functionally favorable position : Considerations on measurement of disability in private accident insurance]

If an accident results in a functional disorder that persists and permanently restricts physical and/or mental capacity, this is referred to as a disability. In private accident insurance it is the task of the medical expert to assess this disability by examining the medical findings and produce an assessment taking account of the literature and comparing against generally acknowledged guidance values. The priority dismemberment disability rating schedule initially provides loss values. For the "next lowest" disability levels for arthrodesis of extremity joints, the assessment recommendations are based on a functionally favorable position although this functionally favorable position is not more precisely defined.In this article the authors have defined these functionally favorable positions based on the information available in the literature. In particular, the operatively favorable settings for arthrodesis of the affected joint that are stated in the literature on trauma and orthopedic surgery were consulted. Of course, the functional perspective has been especially emphasized.A difficulty in achieving this was that the literature on arthrodesis is now almost only of historical value due to modern endoprosthetics. The knowledge gained was checked against medical experience and is expounded here.

A histological study on the tendons at chiasma plantare in pes cavus

INTRODUCTION

In the dysfunction of large muscles of the leg, tendon transfer surgery is found to be very helpful in restoring the normal function of these muscles. The tendons involved in the chiasma plantare play a major role in this regard.

OBJECTIVE

The present cadaveric study has been carried out in cadavers presenting pes cavus.

MATERIAL AND METHODS

Cadaveric feet presenting pes cavus were identified based on their foot prints. All these tendons and their interconnections were subjected to histological procedures. The sections of the tendons were stained with hematoxylin and eosin in order to identify the underlying pathologies in the tendons.

RESULTS

Various types of tendinous interconnections between the tendons of flexor digitorum longus and flexor hallucis longus were noted. The histological findings showed infiltration of lymphocytes in the tendon sheath indicating tenosynovitis and tendinitis. This could be attributed to the compression of the tendons. A few tendons were also stretched due to the skeletal framework of the foot in pes cavus. The bones along the medial longitudinal arch in pes cavus feet could tend to develop spurs or elongated tuberosity that could impinge on the tendons causing the tendons to stretch and elongate.

CONCLUSION

In harvesting the tendons for grafting, the surgeons must be aware about the pathologies involved, such as tendinitis or tenosynovitis, in order to reduce the time taken for the healing of the graft post-surgery. These variations and histological findings can sub-serve as an efficient guide for the restoration of non-functioning muscles of the lower limb.

Combined subtalar distraction arthrodesis with peroneus brevis tenotomy for posttraumatic subtalar arthritis

BACKGROUND

Subtalar distraction arthrodesis is advocated as a salvage procedure for isolated posttraumatic subtalar arthritis. This study aimed at evaluating combined subtalar distraction arthrodesis with peroneus brevis tenotomy for such cases.

METHODS

Twenty patients with isolated posttraumatic subtalar arthritis managed by combined subtalar distraction arthrodesis and peroneus brevis tenotomy were reviewed for a retrospective study. The American orthopaedic foot and ankle society [AOFAS] hindfoot scoring, talocalcaneal height [TCH], talocalcaneal angle [TCA] and heel valgus angle [HVA] were used for both pre and postoperative assessments.

RESULTS

The mean postoperative [TCH] [70.3±1.9mm] was statistically better than the preoperative value [64.7±2.2mm] [p<0.001]. There was a statistically significant decrease in [HVA] [p<0.001]. On the contrary, there was a statistically significant increase in both [AOFAS] hindfoot scoring and the [TCA] [p<0.001].

CONCLUSIONS

Applying this technique for isolated posttraumatic subtalar arthritis with peroneal tendinitis improved both lateral retromalleolar swelling and deformity correction.

Biomechanical Considerations in Rearfoot Fusions

This article discusses rearfoot fusions for foot and ankle surgeons. It establishes normal foot and ankle function primarily in the stance phase of gait. The foot is greatly affected by external and internal forces, which contribute to normal function or the need for compensatory mechanisms. As a result of compensation, many symptoms develop, often leading to debilitating disorders such as degenerative joint disease. The interaction of the ankle, subtalar, and midtarsal joints are outlined. Congenital deformities, trauma and abnormal compensation are reviewed along with corresponding sequelae. Surgery is often indicated to reduce symptoms, improve position, and help stabilize the foot.

Ankle Arthrodesis for Talar Avascular Necrosis and Arthrodesis Nonunion

This article reviews the surgical treatment of talar avascular necrosis. Specifically, arthrodesis for this complex entity and potential treatment of nonunions are discussed. The hallmarks of treatment are evolving and can range from nonoperative measures to amputations. Nonoperative treatment and the results of current arthrodesis techniques for late-stage avascular necrosis are reviewed. Surgical correction requires an understanding of the condition's natural history, utilization of structural and nonstructural bone grafting techniques, and stable fixation. Although the methods described follow standard orthopedic principles, high-quality evidence and outcome studies are limited for treatment of this challenging and often disabling condition.

Open Technique for In Situ Subtalar Fusion

The subtalar joint plays an important role for the hindfoot when accommodating during gait. Joint degeneration may be caused by posttraumatic, inflammatory, and pathologic biomechanical changes. Once conservative treatment has failed, subtalar fusion should be considered. The indication for surgery is based on thorough clinical and radiographic evaluation. Several techniques for subtalar fusion are published in literature. This article aims to describe a technique for in situ arthrodesis of the subtalar joint, paying special attention to biomechanical aspects as well as preoperative clinical and radiological work-up.

Subtalar Arthroscopic Fusion

Arthroscopic subtalar fusion is an excellent approach to subtalar pathologic condition where conservative treatment has failed and a fusion has been indicated. Formal contraindications include excessive malalignment and bone loss. The posterior arthroscopic approach is analyzed in this article, including indications, surgical technique, surgical tips, and complications. Excellent results can be expected, including a shorter time to fusion, and faster rehabilitation, including activities of daily living and sports.

Association of arch height with ankle muscle strength and physical performance in adult men

Differences in arch height may have a certain impact on lower extremity muscle strength and physical performance. However, there is little evidence from investigation of the possible correlation of arch height with ankle muscle strength and physical performance measures. Sixty-seven participants took part in this study. Arch height index (AHI) was assessed and categorized using a 3-dimension foot scanner. Ankle muscle strength was measured employing a dynamometer. Physical performance measures including agility, force and proprioception were randomly tested. Compared to the medium AHI, the high AHI had lower plantarflexion and inversion peak torque. The high AHI also had lower peak torque per body weight value for plantarflexion and inversion at 120°/s (P = 0.026 and 0.006, respectively), and dorsiflexion at 30°/s (P = 0.042). No significant ankle muscle strength difference was observed between the low and medium AHI. Additionally, AHI was negatively correlated with eversion and inversion peak torque at 120°/s, and negatively associated with plantarflexion, eversion and inversion peak torque per body weight at both 30°/s and 120°/s (r ranged from -0.26 to -0.36, P values < 0.050). However, no significant relationship was found between arch height and physical performance measures. The results showed that high arches had lower ankle muscle strength while low arches exhibited greater ankle muscle strength. Arch height was negatively associated with ankle muscle strength but not related to physical performance. We suggest that the lower arch with greater ankle muscle strength may be an adaptation to weight support and shock absorption.

Outcomes and Complications After Open Versus Posterior Arthroscopic Subtalar Arthrodesis in 121 Patients

BACKGROUND

Subtalar arthrodesis is a standard treatment for subtalar arthritis. Both open and arthroscopic techniques have been described and are commonly used. The cases of a consecutive series of 121 patients treated with either open or posterior arthroscopic techniques are presented with functional outcomes and complications.

MATERIALS

A retrospective chart review with prospectively collected data was performed for 121 consecutive patients (129 feet) who underwent subtalar arthrodesis with open (60 feet in 57 patients) or arthroscopic (69 feet in 64 patients) techniques between 2001 and 2014. The technique was selected on the basis of the deformity and surgeon preference. The primary outcomes were the visual analog scale (VAS) for pain, Short Form (SF)-36, Foot Function Index (FFI), and Angus and Cowell rating scores. Secondary outcomes included hindfoot alignment, operative time, length of hospital stay, fusion rate, time to return to work, ability to perform sports and activities of daily living, and complications.

RESULTS

Both groups demonstrated significant improvement in VAS, SF-36, FFI, and Angus and Cowell rating scale scores. The mean operative time, VAS score, Angus and Cowell rating score, and coronal plane hindfoot alignment were similar between the groups. There were no significant differences within the groups with respect to union rate and time to union among the various sizes of screws and types of bone graft. Sural nerve complications and a painful surgical scar were more frequent in the open group, whereas hardware-related symptoms were more frequent in the arthroscopically treated group.

CONCLUSIONS

Subtalar arthrodesis performed with open and arthroscopically assisted techniques demonstrated significant improvement in terms of pain and function as measured with the VAS, FFI, and SF-36. While the time to union and to return to work, activities of daily living, and sports activities were significantly shorter for the arthroscopic arthrodesis group, the union rates and complications overall were not significantly different.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

How Do Hindfoot Fusions Affect Ankle Biomechanics: A Cadaver Model

BACKGROUND

While successful subtalar joint arthrodesis provides pain relief, resultant alterations in ankle biomechanics need to be considered, as this procedure may predispose the remaining hindfoot and tibiotalar joint to accelerated degenerative changes. However, the biomechanical consequences of isolated subtalar joint arthrodesis and additive fusions of the Chopart's joints on tibiotalar joint biomechanics remain poorly understood.

QUESTIONS/PURPOSES

We asked: What is the effect of isolated subtalar fusion and sequential Chopart's joint fusions of the talonavicular and calcaneocuboid joints on tibiotalar joint (1) mechanics and (2) kinematics during loading for neutral, inverted, and everted orientations of the foot?

METHODS

We evaluated the total force, contact area, and the magnitude and distribution of the contact stress on the articular surface of the talar dome, while simultaneously tracking the position of the talus relative to the tibia during loading in seven fresh-frozen cadaver feet. Each foot was loaded in the unfused, intact control condition followed by three randomized simulated hindfoot arthrodesis modalities: subtalar, double (subtalar and talonavicular), and triple (subtalar, talonavicular, and calcaneocuboid) arthrodesis. The intact and arthrodesis conditions were tested in three alignments using a metallic wedge insert: neutral (flat), 10° inverted, and 10° everted.

RESULTS

Tibiotalar mechanics (total force and contact area) and kinematics (external rotation) differed owing to hindfoot arthrodeses. After subtalar arthrodesis, there were decreases in total force (445 ± 142 N, 95% CI, 340-550 N, versus 588 ± 118 N, 95% CI, 500-676 N; p < 0.001) and contact area (282 mm(2), 95% CI, 222-342 mm(2), versus 336 ± 96 mm(2), 95% CI, 265-407 mm(2); p < 0.026) detected during loading in the neutral position; these changes also were seen in the everted foot position. Hindfoot arthrodesis also was associated with increased external rotation of the tibiotalar joint during loading: subtalar arthrodesis in the neutral loading position (3.3° ± 1.6°; 95% CI, 2°-4.6°; p = 0.004) and everted loading position (4.8° ± 2.6°; 95% CI, 2.7°-6.8°; p = 0.043); double arthrodesis in neutral (4.4° ± 2°; 95% CI, 2.8°-6°; p = 0.003) and inverted positions (5.8° ± 2.6°; 95% CI, 3.7°-7.9°; p = 0.002), and triple arthrodesis in all loaded orientations including neutral (4.5° ± 1.8°; 95% CI, 3.1°-5.9°; p = 0.002), inverted (6.4° ± 3.5°; 95% CI, 3.6°-9.2°; p = 0.009), and everted (3.6° ± 2°; 95% CI, 2°-5.2°; p = 0.053) positions. Finally, after subtalar arthrodesis, additive fusions at Chopart's joints did not appear to result in additional observed differences in tibiotalar contact mechanics or kinematics with the number of specimens available.

CONCLUSIONS

Using a cadaveric biomechanical model, we identified some predictable trends in ankle biomechanics during loading after hindfoot fusion. In our tested specimens, fusion of the subtalar joint appeared to exert a dominant influence over ankle loading.

CLINICAL RELEVANCE

A loss or deficit in function of the subtalar joint may be sufficient to alter ankle loading. These findings warrant consideration in the treatment of the arthritic hindfoot and also toward defining biomechanical goals for ankle arthroplasty in the setting of concomitant hindfoot degeneration or arthrodesis.

Isolated Subtalar Arthrodesis

Introduction

An isolated subtalar arthrodesis through a sinus tarsi approach with cannulated screw fixation is safe, reproducible, and effective for specific hindfoot pathology in adults.

Indications & Contraindications

Step 1 Preoperative Planning

Perform a comprehensive clinical and radiographic assessment.

Step 2 Patient Positioning

Position the patient supine on the operating table with a bump under the ipsilateral hip, to internally rotate the involved leg.

Step 3 Incision

Mark a longitudinal incision from just inferior to the tip of the lateral malleolus and extending toward the base of the 4th metatarsal.

Step 4 Approach

Expose the subtalar joint by reflecting the extensor digitorum brevis and protecting the peroneal tendons.

Step 5 Joint Preparation

Meticulously prepare the subtalar joint using osteotomes and curets down to healthy bleeding subchondral bone.

Step 6 Reduction and Fixation

Reduce the subtalar joint into 5° of valgus and fix it with cannulated screws.

Step 7 Wound Closure

Meticulously close the wound in layers and place the lower leg in a well-padded plaster back slab with the ankle in a neutral position.

Step 8 Postoperative Care

The operatively treated leg is kept immobilized and non-weight-bearing for the first 6 weeks.

Results

Numerous retrospective articles have reported high fusion rates and good functional outcomes after isolated subtalar arthrodesis, for all indications.

Pitfalls & Challenges

[Subtalar arthrodesis]

OBJECTIVE

Realignment and stabilization of the hindfoot by subtalar joint arthrodesis.

INDICATIONS

Idiopathic/posttraumatic arthritis, inflammatory arthritis of the subtalar joint with/without hindfoot malalignment. Optional flatfoot/cavovarus foot reconstruction.

CONTRAINDICATIONS

Inflammation, vascular disturbances, nicotine abuse.

SURGICAL TECHNIQUE

Approach dependent on assessment. Lateral approach: Supine position. Incision above the sinus tarsi. Exposure of subtalar joint. Removal of cartilage and breakage of the subchondral sclerosis. In valgus malalignment, interposition of corticocancellous bone segment; in varus malalignment resection of bone segment from the calcaneus. Reposition and temporarily stabilization with Kirschner wires. Imaging of hindfoot alignment. Stabilization with cannulated screws. Posterolateral approach: Prone position. Incision parallel to the lateral Achilles tendon border. Removal of cartilage and breakage of subchondral sclerosis. Medial approach: Supine position. Incision just above and parallel to the posterior tibial tendon. Removal of cartilage and breakage of subchondral sclerosis. Stabilization with screws.

POSTOPERATIVE MANAGEMENT

Lower leg walker with partial weightbearing. Active exercises of the ankle. After a 6‑week X‑ray, increase of weightbearing. Full weightbearing not before 8 weeks; with interpositioning bone grafts not before 10-12 weeks. Stable walking shoes. Active mobilization of the ankle.

RESULTS

Of 43 isolated subtalar arthrodesis procedures, 5 wound healing disorders and no infections developed. Significantly improved AOFAS hindfood score. Well-aligned heel observed in 34 patients; 5 varus and 2 valgus malalignments. Sensory disturbances in 8 patients; minor ankle flexion limitations. Full bone healing in 36 subtalar joints, pseudarthrosis in 4 patients.

Recreational Sports Activities After Calcaneal Fractures and Subsequent Subtalar Joint Arthrodesis

Subtalar joint arthrodesis is a common treatment for the management of hindfoot pathologic entities. Despite pain reduction, hindfoot stiffness is a common concern of active patients, who wish to continue or start exercising for fitness. The purpose of the present retrospective observational clinical study was to assess the rate and type of recreational sports activities in patients before and after subtalar joint arthrodesis and to correlate the clinical outcome and the level of sports activities. In 33 patients (22 males, 11 females) treated with subtalar joint arthrodesis, the pre- and postoperative participation in sports and recreational activities was evaluated. The American Orthopaedic Foot and Ankle Society hindfoot scale score, 36-item Short Form Health Survey, and a visual analog scale for pain were used as clinical outcome measures. The weekly session number, session time, and interval to activity recovery after surgery were registered. Patients with a subtalar joint arthrodesis returned to a satisfactory level of activity postoperatively. The sports participation almost reached levels similar to those preoperatively but with a shift from high- to low-impact activities.

Subtalar joint arthrodesis: open and arthroscopic indications and surgical techniques

Arthrodesis of the subtalar joint can be performed via both open and arthroscopic techniques. Both groups of procedures have their own relative indications and contraindications, as well as complications. Good results have been reported for both general procedures, although some studies suggest superiority with arthroscopic subtalar arthrodesis.

The subtalar joint: biomechanics and functional representations in the literature

The subtalar joint is important for gait and function of the foot and ankle. With few external landmarks, the joint is difficult to conceptualize and study in vivo. There have been several functional representations put forth in the literature which can be combined to give a broader understanding of the overall function and mechanics of the subtalar joint. This understanding is clinically important when considering the impact that disease has on the subtalar joint as well as how treatment of the subtalar joint impacts on the surrounding structures.