Subtalar distractional realignment arthrodesis with wedge bone grafting and lateral decompression for calcaneal malunion

Staged Ilizarov distraction histogenesis and corrective reconstruction for severe malunited calcaneal fractures

PURPOSE

Severe calcaneal malunion is a clinical conundrum for the difficulty of calcaneal reconstruction without soft tissue complications. The aim of this study is to introduce the treatment strategy and preliminary results of staged Illizarov distraction histogenesis and corrective reconstruction for severe malunion of calcaneal fractures.

METHODS

From June 2014 to May 2020, 14 patients with severe calcaneal malunion treated with the staged strategy were retrospectively analyzed. At the first stage, calcaneal osteotomy and external fixation with Ilizarov frame were performed. The restoration of the approximate configuration of calcaneus and the expansion of contractural soft tissue were achieved by gradual calcaneal distraction. At the second stage, corrective reconstruction was performed and autogenous iliac crest bone graft was used. Clinical and radiographic outcomes were evaluated at final follow-up.

RESULTS

The average time of Ilizarov distraction and total fixation was 21.4 days and 41.0 days at first-stage treatment. At a mean follow-up of 33.1 months, the average American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score increased significantly from 24.0 to 72.4 (p < 0.01). And the mean visual analogue scale (VAS) score had improved remarkably from 8.2 to 2.4 (p < 0.01). Radiographs showed that talocalcaneal height, calcaneal width, calcaneal tuberosity height, hindfoot alignment angle, and talar declination angle were improved to a great extent (p < 0.01). Only one patient had minor pin site infection at first-stage treatment and one got superficial wound infection after second-stage surgery. No wound dehiscence, skin necrosis, or deep infection occurred.

CONCLUSION

Staged Ilizarov distraction histogenesis and corrective reconstruction is a safe and effective treatment strategy for reducing soft tissue complications and improving reconstruction results in surgical correction of severe calcaneal malunion.

Subtalar distraction arthrodesis for calcaneal malunion - comparison of structural freeze-dried versus autologous iliac bone graft

BACKGROUND

This study aims to analyze the outcomes of subtalar distraction arthrodesis (SDA) for calcaneal malunion using structural freeze-dried iliac allograft (FDIA) compared to using autologous iliac bone (AIB).

METHODS

We retrospectively evaluated 57 consecutive cases (51 patients) of calcaneal malunion between March 2006 and December 2017. All patients were followed for an average of 22.8 months. All cases were treated by SDA using structural FDIA (17 cases, group 1), or AIB (40 cases, group 2). The outcome measures included the American Orthopaedic Foot and Ankle Society ankle-hindfoot (AOFAS) scores, visual analog scale (VAS) pain scores, and radiographic measurements.

RESULTS

The mean postoperative 3, 6, and 12 months of AOFAS scores and VAS pain score were significantly better in group 2 than those in group 1 (p < 0.05, for all). There were 3 cases (17.6%) of nonunion in the group 1, whereas the group 2 had 2 cases (5.0%), which did not shown significant difference between two groups (p = 0.492). Although the mean pre-, postoperative, and final follow-up radiologic parameters in both groups were similar, (p > 0.05, for all) the difference of talocalcaneal height, talocalcaneal angle, and talar declination angle from postoperative to final follow-up were significantly bigger in the group 1. (p < 0.05, for all).

CONCLUSION

Although union rate was not significantly different between the two groups, we obtained more favorable clinical and radiologic outcomes in the autologous iliac bone group. Using FDIA without any orthobiological agent for SDA, there were significant more loss of radiological parameters due to inferior incorporation and biomechanical properties. When considering the SDA for calcaneal malunion, routine use of FDIA without any orthobiological agents as an interpositional graft for SDA is not recommended.

Systematic Review of Subtalar Distraction Arthrodesis for the Treatment of Subtalar Arthritis

BACKGROUND

Subtalar distraction arthrodesis (SDA) was developed as a means of treating the symptoms of subtalar arthritis. Despite almost 30 years of research in this field, many controversies still exist regarding SDA. The objective of this study was to present an overview of outcomes following SDA, focusing on surgical technique as well as clinical and radiographic results.

METHODS

MEDLINE and EMBASE were queried and data abstraction was performed by 2 independent reviewers. Inclusion criteria for the articles were (1) English language, (2) peer-reviewed clinical studies with evidence levels I to IV, (3) with at least 5 patients, and (4) reporting clinical and/or radiographic outcomes of SDA.

RESULTS

Twenty-five studies matched the inclusion criteria (2 Level III and 23 Level IV studies) including 492 feet in 467 patients. The most common indication for SDA was late complications of calcaneus fractures. Many different operative techniques have been described, and there is no proven superiority of one method over the other. The most commonly reported complications were nonunion, hardware prominence, wound complications, and sural neuralgia. All studies showed both radiographic and clinical improvement at the last follow-up visit compared with the preoperative evaluation. Pooled results (12 studies, 237 patients) demonstrated improved American Orthopaedic Foot & Ankle Society ankle-hindfoot scores with a weighted average of 33 points of improvement.

CONCLUSION

SDA provides good clinical results at short-term and midterm follow-up, with improvement in ankle function as well as acceptable complication and failure rates. Higher quality studies are necessary to better assess outcomes between different operative techniques.

LEVEL OF EVIDENCE

Level III.

Sagittal Resection Osteotomy With Bone Block Distraction Subtalar Fusion for Treatment of Malunited Calcaneal Fractures

The aim of this prospective study was to evaluate the results of combined lateral sagittal resection osteotomy with subtalar distraction fusion in heels with painful malunion of the os calcis. This case series included 22 patients (23 feet). The mean age of the patients was 37.52 years. Sixteen (69.6%) patients were initially treated conservatively, 5 (21.7%) patients were treated surgically, and 2 (8.7%) patients were missed. The mean time lapsed before surgery was 11.43 months. A wedge of bone was resected to reduce the width of the malunited os calcis and was used as a local graft for subtalar joint fusion and to increase the height of the os calcis. The mean follow-up period was 56.83 ± 6.09 months. According to the scoring system, satisfactory results were found in 18 (82.6%) patients, and 4 (17.4%) patients had unsatisfactory results. Postoperative radiographic assessment revealed an average increase in the heel height of 7.70 ± 1.22 mm and an average decrease in heel width of 8.39 ± 1.47 mm. The average correction in the coronal axis was approximately 8.04° ± 1.26°. Complications included infection and nonunion in 3 (13%) heels. Two heels still had residual varus postoperatively, and 1 patient had injury to the sural nerve. The restoration of heel height, the reduction in heel width, and the primary fracture pattern had a significant relation with the final score. This method is a successful method for the management of subtalar arthritis caused by malunited calcaneal fractures with broadening leading to lateral abutment.

The value of Weight-Bearing CT scan in the evaluation of subtalar distraction bone block arthrodesis: Case report

Subtalar distraction arthrodesis is performed in certain situations where there is loss of subtalar height, reduced talar declination and evidence of anterior tibiotalar impingement. Standard evaluation includes the assessment of the lateral talocalcaneal angle, calcaneal pitch, talocalcaneal height and talar declination angle on a weight bearing lateral radiograph. We present a case of erosive valgus subtalar osteoarthritis with subtalar collapse managed with a subtalar distraction arthrodesis. A weight bearing CT (WB-CT) scan was used in the assessment. The value of WB-CT for this indication is discussed, along with a discussion on surgical technique, complications and future directions.

Comparative study of subtalar arthrodesis after calcaneal frature malunion with autologous bone graft or freeze-dried xenograft

Background

Calcaneal fracture malunion may evolve into arthrosis and severe foot deformities. The aim of this study was to identify differences in bony union following corrective subtalar arthrodesis with interposition of autologous tricortical bone graft or freeze-dried bovine xenograft.

Methods

We prospectively evaluated 12 patients who underwent subtalar arthrodesis, six patients received autografts and 6 received freeze-dried bovine xenografts. After a mean followup of 58 weeks, the patients were clinical assessed using AOFAS scale and the visual analog scale (VAS) for pain and for final radiographic parameters measurement. Two blind raters evaluated the length of time required for solid union of the arthrodesis and graft integration by retrospective radiographic examination.

Results

In the autograft group, AOFAS score improved from a preoperative average of 37 to 64 points postoperatively (p = 0.02) and mean VAS score improved from 4.7 to 1.9 (p = 0.028). In the xenograft group, AOFAS score improved from 38 to 74 points (p = 0.02) and VAS from 5.5 to 2.7 (p = 0.046). Solid union was achieved in all cases in the autograft group at an average of 5.3 weeks and in five cases in the xenograft group at 8.8 weeks (p = 0.077). Graft integration occurred after an average of 10.7 weeks in the autograft group and 28.8 weeks in the xenograft group (p = 0.016).

Conclusion

With the numbers available, no significant difference could be detected in the length of time required for solid union of subtalar arthrodesis between groups, although time to integration of freeze-dried bovine xenografts was statistically higher. Clinical and functional improvement was observed in both groups.

Surgical tip: Titanium foam blocks can simplify fusion of failed total ankle replacements

Ankle arthrodesis following failed ankle replacements is a technically challenging task because of the large defect left behind after the prosthesis is removed. The usual practice is to use bulk grafts which are either autografts or allografts to fill the defect. We report our experience with the use of a titanium foam block specifically designed for fusion of failed ankle replacements. This particular method was chosen to avoid the technical difficulties and morbidities associated with the use of bulk autografts and allografts. We describe the surgical technique and early results in the first two cases performed in our unit. The satisfactory clinical and radiologic results in the two cases demonstrate the ability of the titanium foam block to simplify an otherwise complex procedure without compromising the outcome.

Outcome After Operative Fusion of the Tarsal Joints: A Systematic Review

Arthrodesis of 1 or more joints of the hindfoot is performed to treat severe functional impairment due to pain, deformity, and/or instability. Evaluation of the results of hindfoot arthrodesis from the published data has been difficult owing to the great variety of pathologic entities and surgical techniques reported in the studies. A comprehensive search for relevant reports, reference lists, and citation tracking of the included studies was conducted using the PubMed(®), Embase(®), and CINAHL(®) databases. The studies had to have been prospective, included patients with hindfoot problems, evaluated arthrodesis of 1 or more tarsal joints, and had at least 1 of the following primary clinical outcome parameters: pain, function, or complications. Two of us independently selected the relevant studies using predefined criteria and graded the quality of evidence using a 0 to 9 star scale according to the Newcastle-Ottawa Scale. A total of 16 prospective case series were included; 5 studies scored 6 stars, 8 scored 5 stars, 2 scored 4 stars, and 1 scored 3 stars. A best evidence synthesis was performed, and improvement in function and pain was found for 3 combinations: talonavicular arthrodesis for rheumatoid arthritis, triple arthrodesis for rheumatoid arthritis, and subtalar arthrodesis for post-traumatic arthritis showed good results for pain and function, the last especially when performed arthroscopically. The best evidence syntheses revealed good results for pain and function for these disease-operative technique combinations.

Mid-term follow up results of subtalar distraction arthrodesis using a double bone-block for calcaneal malunion

PURPOSE

This study was designed to evaluate the mid-term results and efficacy of subtalar distraction double bone-block arthrodesis for calcaneal malunion.

MATERIALS AND METHODS

From January 2004 to June 2007, we operated on 6 patients (10 cases). There were 5 males (9 cases) and 1 female (1 case), four of which presented with bilateral calcaneal malunion. Seven cases were operated on initially. The period between initial injury and arthrodesis was 23 months, and the average follow up period was 58 months. In operation, we applied an extensile lateral approach and arthrodesis was performed through a tricortical double bone-block and cannulated screws. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scale was used for clinical evaluation. In radiologic analysis, plain X-ray and CT were examined to assess union and various parameters.

RESULTS

The mean age of the patients was 41 years. All cases achieved radiologic union at the final follow-up. The mean AOFAS Ankle-Hindfoot scale (maximum of 94 points) increased from 43.3 points preoperatively to 85.4 points at the final follow-up. The radiologic analysis of the pre- and postoperative standing lateral radiographs showed improvements of 5.6 mm in talo-calcaneal height, 1.8° in talocalcaneal angle, 5.1° in talar declination angle and 5.3° in talo-first metatarsal angle.

CONCLUSION

Subtalar distraction two bone-block arthrodesis provides overall good results not only in the short term but also the mid-term with significant improvement in clinical and radiologic outcomes. This procedure warrants consideration for managing calcaneal malunion with loss of height and subtalar arthritis.

Reconstruction of calcaneal fracture malunion with osteotomy and subtalar joint salvage: technique and outcomes

BACKGROUND

The goal of this study was to discuss the outcomes of treating calcaneal fracture malunion by restoring the subtalar joint with a reconstructive osteotomy.

METHODS

From May 2005 to November 2008, 24 patients (26 feet) with calcaneal malunions after a displaced intra-articular calcaneal fracture were treated by osteotomy and autogenous bone graft. The subtalar joint was preserved. The mean time from initial injury to reconstructive operation was 5.7 months (95% confidence interval, 4.5-8.8 months). The displaced posterior facet was restored through a reconstructive osteotomy, whereas the bone defect in the calcaneus after reduction was filled with the exostosis that had been removed; iliac bone graft was used if necessary. All patients were evaluated clinically and radiographically at a minimum of 24 months. Twenty patients (21 feet) were followed for a mean of 34.2 months (29.0-39.4 months).

RESULTS

According to American Orthopaedic Foot & Ankle Society (AOFAS) ankle and hindfoot score, the average score was 85.9 points (95% confidence interval, 81.5-90.4 points), which was significantly higher than the preoperative assessment. Radiographs showed that Böhler's angle, Gissane's angle, talus declination angle, and width and height of calcaneus were improved to a great extent. Six patients had wound edge necrosis, and 2 had superficial infection. One patient required a subtalar fusion for subtalar arthritis at 2 years after surgery.

CONCLUSIONS

Restoring the subtalar joint with a reconstructive osteotomy and autogenous bone graft was an effective treatment method for selected calcaneal fracture malunions. It reconstructed calcaneal morphology and preserved the subtalar joint.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Subtalar distraction arthrodesis using fresh-frozen allogeneic femoral head augmented with local autograft

BACKGROUND

Tricortical autograft has been commonly used in subtalar distraction arthrodesis (SDA) for severe calcaneal malunion. Structural allograft enriched with orthobiological agents is an alternative. This study was performed to evaluate the results of SDA using fresh-frozen allogeneic femoral head without the addition of orthobiological agents.

MATERIALS AND METHODS

We retrospectively reviewed 15 consecutive SDA procedures (13 patients) with allogeneic femoral head augmented with local autograft for the treatment of severe calcaneal malunion. Clinical outcome was evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, visual analog scale (VAS) pain score, Short Form-12 (SF-12), range of motion (ROM) of the ankle joint, and patient satisfaction rate. Radiographic assessment included the talar declination angle (TDA), calcaneal inclination angle (CIA), lateral talocalcaneal angle (LTCA), heel height, calcaneal length, and union time.

RESULTS

At a median follow-up of 36.0 months (range, 24-47 months), all 15 feet (100%) achieved union, at a median of 13.0 weeks (range, 12-18 weeks). The AOFAS score and VAS pain score improved significantly, with a satisfaction rate of 93.3%. The TDA, CIA, LTCA, and heel height improved significantly. The median increase in heel height was 8.6 mm (range, 1.9-20.1 mm). There was a significant reduction in calcaneal length. Complications included 1 varus malalignment, 1 complex regional pain syndrome, 1 hardware irritation, and 1 sural neuralgia.

CONCLUSION

This study found that SDA using fresh-frozen femoral head allograft without an orthobiological agent was cost-effective and may have outcomes comparable to those using autograft or allograft enriched with orthobiological agents.

The subtalar distraction bone block arthrodesis following the late complications of calcaneal fractures: a systematic review

INTRODUCTION

The late complications following a displaced intra-articular calcaneal fractures includes painful arthrosis for which a subtalar fusion might be considered. In case of malalignment due to loss of height and varus deformity a reconstructive arthrodesis is necessary. The primary aim of the current review study was to assess the functional outcome of the subtalar distraction bone block arthrodesis in the management of late complications of displaced intra-articular calcaneal fractures.

METHODS

The literature was searched for studies in which a subtalar distraction bone block arthrodesis was used in the management of persistent complaints following a displaced intra-articular calcaneal fractures, after its first description in 1988 up to November 1st 2011. The methodological quality of the included studies was assessed using the Coleman Methodology Score.

RESULTS

Twenty-one studies reporting on 456 patients were identified. In 93 percent the procedure was a salvage procedures following the late complications of a calcaneal fracture (372 cases). Duration of follow-up ranged from 21 to 108 months (average 40 months). Union rates were reported with an overall average of 96% (range 83-100%). The average modified AOFAS score (maximum 94 points) was 73 points at final follow-up (range 64-83 points). Six studies reported pre- and post-reconstruction AOFAS outcome scores with an average increase of 44.2 points. Wound complications occurred in approximately 6%. With the exception of one study all were level 4 retrospective case series, with an average Coleman Methodology Score of 55 (range 41-79) points.

CONCLUSIONS

The subtalar distraction bone block arthrodesis is a technically demanding procedure which, in the right hands, provides an overall good result. This is reflected in a significant increase in outcome scores post-operatively. Although most complications are considered minor, there are several pitfalls which should be recognized and avoided.

Distraction arthrodesis of subtalar joint using a laterally placed hinged distractor

Many joint-depressive, neglected calcaneal fractures need distraction arthrodesis of the subtalar joint. Because the calcaneal tuberosity is usually malunited in the varus position, more distraction is required on the medial side to place the tuberosity in the everted position before insertion of a bone graft. Traditionally, a distractor is placed on the medial side to achieve this task. However, the medially placed distractor hinders with the positioning of the extremity and exposure of the main operative site, which is commonly on the lateral side. We introduce a technique to avoid this burden by placing a hinged distractor device on the lateral aspect of the foot while maintaining the correction of the varus deformity.

Porous tantalum as a structural graft in foot and ankle surgery

BACKGROUND

Structural bone grafts are often used in foot and ankle surgery to fill gaps, maintain height, length or correction. Bone graft, whether autograft or allograft, has limitations and disadvantages. With porosity and mechanical properties similar to native bone, porous tantalum has been used successfully in hip and knee applications. This study investigates the potential advantages of porous tantalum as a substitute for conventional bone graft in foot and ankle surgery.

METHODS

A retrospective review of 27 arthrodesis procedures was performed of foot and ankle procedures using Trabecular Metal porous tantalum over a period of 5 years. Twenty-five patients were involved. Mean age at the time of surgery was 63 (range, 41 to 80) years. All the patients had pathologies in the foot and ankle that required arthrodesis with structural graft. Average followup was 27 (range, 12 to 72) months.

RESULTS

At final followup the mean American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot/Midfoot score improved from 40.6 (range, 16 to 64) preoperatively to 86.3 (range, 57 to 100) postoperatively (p < 0.001). When the pain component of the AOFAS was examined, the score improved from a mean of 8.2 (range, 0 to 20) to 35.2 (range, 20 to 40), (p < 0.001). At the time of last followup, 56% of patients reported no pain, 40% reported mild occasional pain, and 4% reported moderate pain.

CONCLUSION

Porous tantalum therefore, was found to be a viable alternative to conventional bone graft when structural support was required.

Distraction arthrodesis of the subtalar joint using allogeneic bone graft: a review of 15 cases

Distraction arthrodesis of the subtalar joint is often used for the correction of neglected calcaneal fractures. Although different techniques have been advocated, there remains some debate as to the optimal type of bone graft for this purpose. This study retrospectively reviewed one surgeon's results for distraction arthrodesis of the talocalcaneal joint for 15 consecutive feet in 15 patients using 12 frozen femoral head and 3 freeze-dried iliac crest allografts. Indications for distraction arthrodesis in this series included neglected calcaneal fracture (n = 10), failed open reduction with internal fixation (n = 3), malunion after ankle fusion (n = 1), and subtalar joint arthritis with deformity (n = 1). The mean patient age was 47.5 (range 29 to 66) years, and the mean duration of follow-up was 20.6 (range 13 to 31) months. Complete union was achieved in 14 (93.33%) feet. Orthobiological agents were used in every case, including 7 (46.67%) platelet-rich plasma, 5 (33.33%) demineralized bone matrix combined with platelet-rich plasma, 2 (13.33%) platelet-rich plasma combined with an implantable electrical bone growth stimulator, and 1 (6.67%) demineralized bone matrix only. One (6.67%) patient developed a nonunion with collapse of the allogeneic graft, requiring revision with autogenous iliac crest bone graft. There were 8 (53.33%) minor complications, including 4 (26.66%) cases with inferior heel irritation, 2 (13.33%) with sural nerve paresthesia, and 2 (13.33%) with wound dehiscence. In conclusion, the use of allograft for subtalar joint distraction arthrodesis results in similar union rates as autogenous iliac crest grafting previously reported in the literature.

Can porous tantalum be used to achieve ankle and subtalar arthrodesis?: a pilot study

A structural graft often is needed to fill gaps during reconstructive procedures of the ankle and hindfoot. Autograft, the current gold standard, is limited in availability and configuration and is associated with donor-site morbidity in as much as 48%, whereas the alternative allograft carries risks of disease transmission and collapse. Trabecular metal (tantalum), with a healing rate similar to that of autograft, high stability, and no donor-site morbidity, has been used in surgery of the hip, knee, and spine. However, its use has not been documented in foot and ankle surgery. We retrospectively reviewed nine patients with complex foot and ankle arthrodeses using a tantalum spacer. Minimum followup was 1.9 years (average, 2 years; range, 1.9-2.4 years). Bone ingrowth into the tantalum was analyzed with micro-CT in three of the nine patients. All arthrodeses were fused clinically and radiographically at the 1- and 2 year followups and no complications occurred. The American Orthopaedic Foot and Ankle Society score increased from 32 to 74. The micro-CT showed bony trabeculae growing onto the tantalum. Our data suggest tantalum may be used as a structural graft option for ankle and subtalar arthrodesis. All nine of our patients achieved fusion and had no complications. Using tantalum obviated the need for harvesting of the iliac spine.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Subtalar distraction arthrodesis through a posterior approach

BACKGROUND

Subtalar arthrodesis is a common procedure for treating subtalar arthrosis. An isolated lateral incision can be used as an approach to subtalar fusion alone. However, it can be a difficult approach for correction of varus or valgus hindfoot deformities through the subtalar joint; especially if it involves distraction to correct calcaneal alignment. Less commonly, two-incision or single-incision medial approaches also have been described, but distraction and angular correction can still be difficult. We present an alternative method, using a posterior Achilles tendon-splitting procedure, that gives excellent subtalar exposure and the ability to obtain distraction with angular correction and bone grafting.

MATERIALS AND METHODS

Six consecutive patients underwent subtalar fusion with a posterior approach. Both varus and valgus deformities secondary to trauma, tendon insufficiency, or congenital deformities were corrected. Distraction was accomplished with laminar spreaders, and fixation was obtained with two 7.3-mm partially threaded cannulated screws. All patients were followed until fusion, and clinical and radiographic results were recorded. No other concomitant procedures were performed.

RESULTS

Fusion was observed radiographically in all patients by 3 months postoperatively. No serious wound complications occurred. Correction to slightly valgus alignment (for varus deformity) or neutral alignment (for valgus deformity) was obtained without collapse of autologous bone graft. Talocalcaneal height and all angular measurements were significantly increased (all p < 0.05).

CONCLUSION

The posterior approach for distraction arthrodesis is an alternative to the standard lateral approach technique. It allows safe exposure with the ability to distract while also correcting varus or valgus deformity of the subtalar joint.

Subtalar distraction arthrodesis using interpositional frozen structural allograft

BACKGROUND

Subtalar bone-block distraction arthrodesis using structural autograft carries the risk of donor site morbidity. Recent reports suggest that structural allograft may be an attractive alternative to structural autograft in subtalar arthrodesis. This prospective study analyzes subtalar distraction arthrodesis using interpositional structural allograft.

MATERIALS AND METHODS

Between 2000 and 2006, 22 patients (24 feet; mean age, 45.6 years) underwent subtalar arthrodesis with interpositional fresh-frozen femoral head structural allograft. Indications included subtalar arthrosis, loss of heel height, and anterior ankle impingement. Clinical outcome was assessed using the AOFAS ankle-hindfoot scoring system. Time to union was determined by previously reported clinical findings and radiographic evidence for bridging trabeculation between host bone and structural allograft.

RESULTS

Mean followup was 35.8 months for 20 patients (21 feet) available for followup evaluation. Union was achieved in 19 of 21 patients (90%) at a mean of 15.5 (range, 11 to 19) weeks. Mean AOFAS hindfoot score improved from 21 to 71 points (p < 0.05). Radiographic analysis suggested significant (p < 0.05) improvement in all measurements. Complications included nonunion (2), varus malalignment (1), persistent subfibular impingement (1), sural neuralgia (1), and prominent hardware (2). Both patients with nonunions had avascular bone at the arthrodesis site and used tobacco products.

CONCLUSION

This study supports recent publications that subtalar arthrodesis using interpositional structural allograft can have a favorable outcome. Our clinical and radiographic results suggest that restoration of hindfoot function and dimensions with structural allograft are comparable to results reported for the same procedure using structural autograft.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Posterior bone block distraction arthrodesis of the subtalar joint: a review of 22 cases

Twenty-two patients underwent a posterior bone block distraction arthrodesis of the subtalar joint between 1999 and 2006. The indication for surgery was loss of heel height, subtalar joint arthrosis, decreased talar declination with associated tibiotalar impingement, insufficient Achilles tendon function, malalignment of the rear foot, and pain with ambulation. There were 11 male and 11 female patients with a mean age of 46.7 years (range 20 to 71). The mean follow-up period was 27.3 months (range 12 to 63.9 months). Radiographic analysis revealed a mean increase in heel height of 6.09 mm (P= .0001), 5.83 degrees (P= .12) of lateral talocalcaneal angle, 5.5 degrees (P= .06) of talar declination, and 5.23 degrees (P= .07) of calcaneal inclination. The talo-first metatarsal angle increased an average of 4.5 degrees (P= .18). There was a 95.5% union rate. Postoperative complications included nonunion in 1 patient, subsidence of graft (collapse) in 1 patient, wound dehiscence in 3 patients, painful hardware in 7 patients, sural neuritis in 1 patient, superior cluneal nerve dysfunction in 1 patient and one mild varus malunion. Posterior bone block distraction arthrodesis can be successfully used to restore heel height, realign the foot, and decrease the morbidity associated with late complications of calcaneal fractures, as well as, nonunion and/or malunion following subtalar joint arthrodesis, Charcot neuroarthropathy, and avascular necrosis of the talus.

LEVEL OF CLINICAL EVIDENCE

4.

Effect of foot shape on the three-dimensional position of foot bones

To eliminate some of the ambiguity in describing foot shape, we developed three-dimensional (3D), objective measures of foot type based on computerized tomography (CT) scans. Feet were classified via clinical examination as pes cavus (high arch), neutrally aligned (normal arch), asymptomatic pes planus (flat arch with no pain), or symptomatic pes planus (flat arch with pain). We enrolled 10 subjects of each foot type; if both feet were of the same foot type, then each foot was scanned (n=65 total). Partial weightbearing (20% body weight) CT scans were performed. We generated embedded coordinate systems for each foot bone by assuming uniform density and calculating the inertial matrix. Cardan angles were used to describe five bone-to-bone relationships, resulting in 15 angular measurements. Significant differences were found among foot types for 12 of the angles. The angles were also used to develop a classification tree analysis, which determined the correct foot type for 64 of the 65 feet. Our measure provides insight into how foot bone architecture differs between foot types. The classification tree analysis demonstrated that objective measures can be used to discriminate between feet with high, normal, and low arches.

Arthrodesis as salvage for calcaneal malunions

Even with greater emphasis on anatomic reduction, outcomes after calcaneal fractures continue to be unsatisfactory in many patients. Lateral wall impingement, subtalar arthrosis with pain and stiffness, nerve compression syndromes, and hindfoot malalignment all can cause disabling symptoms. If conservative treatment fails to relieve symptoms, subtalar arthrodesis can provide a painless, stable hindfoot in most patients. For severe deformity with anterior ankle impingement and loss of the talar angle of declination, distraction bone block arthrodesis through a posterior approach is preferred.