Foot function after subtalar distraction bone-block arthrodesis

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.

Subtalar distraction osteogenesis for posttraumatic arthritis following intra-articular calcaneal fractures

BACKGROUND

The most common treatment for old calcaneal fractures accompanied by subtalar joint injury is the use of subtalar in situ arthrodesis and subtalar distraction bone-block arthrodesis or osteotomy. This article describes the introduction of a novel surgical treatment, gradual subtalar distraction with external fixation and restoration of the calcaneal height, and presents an assessment of its efficacy.

METHODS

The protruding lateral calcaneus and the articular surfaces and subchondral bone of the posterior facet of the subtalar joint were surgically removed. An external fixator, attached with 2 pins in the subcutaneous tibia and 2 pins in the posterolateral calcaneus, was used to fix the subtalar joint for 7 to 10 days followed by gradual subtalar distraction at 1 mm/d. The lengthening procedure was stopped when the calcaneal height was restored according to radiography. The external fixator was removed after bone fusion. Seven cases of old calcaneal fractures accompanied by severe subtalar joint injury (8 feet) were treated using this method. Average follow-up was 14.3 months (range, 7-36 months).

RESULTS

In all 7 cases (1 case of both feet), the postoperative wound healed primarily. The calcaneal heights of all 8 feet were partially restored. Subtalar joint bone fusion was completed within 4 to 6 months after the operation. The average preoperative American Orthopedic Foot & Ankle Society (AOFAS) hindfoot score was 25.3, and the average postoperative AOFAS score was 76.3.

CONCLUSION

Subtalar distraction osteogenesis with external fixation was a novel and effective method for the treatment of old calcaneal fractures accompanied by severe subtalar joint injury in this small group of patients.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The midfoot load shows impaired function after ankle arthrodesis

BACKGROUND

A large number of parameters are registered by pedobarography, usually requiring a research setting for interpretation. The purpose of this study was to evaluate which pedobarographic parameters (adjusted for walking speed and body weight) discriminate between healthy volunteers and patients after ankle or tibiotalocalcaneal arthrodesis. Furthermore, we evaluated which parameters are associated with the American Orthopaedic Foot and Ankle Society (AOFAS) score.

METHODS

Thirty-five healthy volunteers, 57 patients with ankle and 42 with tibiotalocalcaneal arthrodesis were assessed by AOFAS scores and dynamic pedobarography. The arthrodesis patients were further investigated with radiographs. Median follow up was 4 years. Eighteen basic parameters were measured each in the hind-, mid-, and forefoot. For dimension reduction, we represented a pre-selected set of 9 parameters by two indices (load, rollover). We used ordinal logistic and multiple linear regression to address the questions.

FINDINGS

The midfoot index of load was the most important pedobarographic predictor (interquartile range odds ratio 100; 95% confidence interval 13, 771) for belonging to the healthy volunteers rather than the ankle or tibiotalocalcaneal arthrodesis groups. Similarly, it was an independent predictor for the AOFAS score (interquartile range effect 5 points; 95% confidence interval 1, 9). Healthy volunteers had a deeper midfoot depression in the force/pressure time graphs compared to patients after arthrodesis.

INTERPRETATION

When evaluating foot function after ankle or tibiotalocalcaneal arthrodesis, the interpretation of a large number of pedobarographic parameters can be reduced to the interpretation of the midfoot index of load and the evaluation of the force/pressure time graphs.

Management of calcaneal fractures: what have we learnt over the years?

Calcaneal fractures result, in many cases, in, subtalar joint stiffness and severe disability. Diagnosis is usually made by X-ray, but more accurately by a computed tomography (CT) scan. In the last years, much has been known regarding its physiopathology and osteosynthesis. Although new developments in osteosynthesis materials have been made, calcaneus fractures still remains in dispute of those advocating non-operative treatment and those defending open reduction and internal fixation. Less invasive surgery, arthroscopy and three-dimensional (3D) fluoroscopy are very important for reduction accuracy and soft-tissue damage avoidance. In this article, the physiopathology, diagnosis, classification and treatment of calcaneus fractures are updated. Nevertheless, systematic reviews have shown no evidence about what treatment is better.

Calcaneal reconstruction for the late complication of calcaneus fracture

Calcaneal fracture is the most common fracture in the tarsal bones. Treatment is difficult because the patterns of fracture are various and complications occur frequently. The purpose of this study was to evaluate the clinical results of calcaneal reconstruction for chronic complications after calcaneal fracture. rom September 2001 to November 2004, calcaneal reconstruction was performed in 24 patients (25 feet). We reviewed 21 patients (22 feet) who could be followed up >2 years postoperatively. Patients who underwent subtalar arthrodesis and simple bone resection were excluded. Patients who underwent calcaneal sliding osteotomy were included. Nineteen men and 2 women ranged in age from 27 to 54 years (mean, 44.4 years). The mean interval between the first operation and reconstructive operation was 11.2 months (range, 3-31 months). The mean follow-up period after calcaneal reconstruction was 29.8 months (range, 24-38 months). Böhler angle, calcaneal pitch, and talocalcaneal height were checked pre- and postoperatively. The most common patient report was pain on the inferior aspect of the lateral malleolus (16 patients) and calcaneal tuberosity (3 patients). All the mean values of talocalcaneal height, calcaneal pitch, and Böhler angle improved, which was statistically significant. In the postoperative period, 10 patients were very satisfied, 9 were satisfied, and 3 were not satisfied. Although pain did not completely resolve, all patients were satisfied postoperatively.

Management of valgus extra-articular calcaneus fracture malunions with a lateral opening wedge osteotomy

A total of 34 cases of symptomatic valgus deformity of the hindfoot secondary to a malunited extra-articular calcaneal fracture were corrected with laterally based open wedge calcaneal osteotomy. The pre- and postoperative radiographic parameters were compared, and a postoperative clinical evaluation was performed using the American Orthopedic Foot and Ankle Society ankle and hindfoot scoring system. The mean follow-up period was 56.2 (range 24.1 to 97) months. The most significant radiographic changes were improvement in the talonavicular coverage angle (mean 17.3°) on the anteroposterior view. The mean postoperative American Orthopedic Foot and Ankle Society hindfoot and ankle score was 90, with 23 excellent, 8 good, and 3 poor results. Laterally based opening wedge osteotomy of the calcaneus is effective in the management of a valgus heel resulting from malunited extra-articular calcaneal fractures. Lateral decompression of the peroneal tendons and the sural nerve was achieved indirectly through opening wedge lateral calcaneal osteotomy that shifted the weight-bearing axis laterally.

Plantar pressure distribution after tibiotalar arthrodesis

INTRODUCTION

Arthrodesis is a well-established treatment option for end-stage osteoarthritis of the ankle. Osteoarthritis of the ankle can alter plantar pressure distribution. However, surprisingly little is known about the effect of ankle arthrodesis to alter plantar pressure distribution. The purpose of this study was to determine plantar pressure distribution in a selected group of patients with unilateral arthrodesis of the ankle joint.

METHODS

20 patients with an average age of 60 years who underwent isolated unilateral ankle arthrodesis using a 3-crossed screw technique by a single surgeon were included. After a mean of 25 months (range 12-75 months) post surgery plantar pressure distribution was determined in five regions of the foot. The outcome was evaluated clinically, using the American Orthopaedic Foot and Ankle Society hindfoot score, as well as radiographically. The contralateral normal foot was used as a control.

FINDINGS

Comparing the foot that underwent tibiotalar arthrodesis to the contralateral normal foot, differences were found in the peak pressure and maximum force in the toe region and the lateral midfoot region. In addition, a decrease in the contact time in the forefoot region and a decrease of the contact area in the toe region of the operated foot were identified. The other regions did not show a significant difference. The mean American Orthopaedic Foot and Ankle Society score of the operated leg was 79 (range 46-92) at the last follow up, and the mean fixation angle of the arthrodesis on lateral weight bearing radiographs was 90° (range 86°-100°).

INTERPRETATION

Our results indicate that arthrodesis of the ankle joint can provide high levels of function with minimal changes in the plantar pressure distribution.

Outcome of subtalar fusion using bovine cancellous bone graft: a retrospective case series

Solvent preserved bovine cancellous bone graft (Tutobone(®)) has been promoted as an alternative to autologous bone graft. The aim of our study was to compare the outcomes of subtalar fusion in patients in whom Tutobone(®) was used with the outcomes in patients in whom it was not used. This was a retrospective comparative study. Tutobone(®) was used in 9 patients in the test group. Of these repairs, 6 were isolated subtalar fusions, and 3 were performed as a part of triple arthrodesis. A total of 17 patients were included in the control group; 4 underwent autologous iliac crest grafting and 13 received a local bone graft from excised joint surfaces. At 12 months after surgery, 8 of the 9 in the Tutobone(®) group had persistent pain and radiologic signs of nonunion confirmed on computed tomography scan. All 17 in the other group had successful clinical and radiologic fusion at 12 months. We believe this is sufficient evidence to advise against the use of bovine cancellous bone graft material for subtalar fusion surgery.

Hindfoot arthrodesis for management of bone loss following calcaneus fractures and nonunions

Massive bone loss following calcaneal fractures is a challenging condition to treat, especially if nonunion is present. Meticulous preoperative examination and imaging are crucial for accurate preoperative planning. If performed, successful outcomes can be achieved with the strategies outlined in this article.

[Computer-assisted surgery-(CAS-)guided correction arthrodesis of the subtalar joint]

OBJECTIVE

Restoration of a stable and plantigrade foot in deformities at the hindfoot and concomitant degenerative changes at the subtalar joint.

INDICATIONS

Deformities at the hindfoot and concomitant degenerative changes at the subtalar joint.

CONTRAINDICATIONS

Active local infection or relevant vascular insufficiency.

SURGICAL TECHNIQUE

Prone position and posterolateral approach to the subtalar joint. Placement of dynamic reference bases in talus and calcaneus through stab incisions. Two-dimensional image acquisition for navigation. Definition of the axes of talus and calcaneus, and of the extent of correction. Exposure of the subtalar joint and removal of remaining cartilage. Computer- assisted surgery-(CAS-)guided correction and transfixation of the corrected position with two 2.5-mm Kirschner wires. Transplantation of autologous cancellous and cortical bone, if necessary. Three-dimensional (3-D) image acquisition for analysis of the accuracy of the correction and planning of the drillings for the screws. CAS-guided drilling and insertion of the screws. 3-D image acquisition for analysis of the accuracy of the correction implant position. Wound closure in layers.

POSTOPERATIVE MANAGEMENT

15 kg partial weight bearing in an orthosis (e.g. Vacuped TM, OPED Inc., Valley, Germany) for 6 weeks, followed by full weight bearing in a stable standard shoe.

RESULTS

From September 1, 2006 to August 31, 2008, 26 correction arthrodeses were performed. The accuracy was assessed by intraoperative 3-D imaging. All achieved angles/translations were within a maximum deviation of 2°/2 mm when compared to the planned correction. Complications that were associated with CAS were not observed. In all 25 cases that completed 2-year follow-up, timely fusion was registered.

Management of calcaneal malunion

The potential for disabling malunion following calcaneal fracture is high, regardless whether a patient is treated nonsurgically or surgically. Fracture displacement typically results in loss of hindfoot height, varus heel position, and widening of the hindfoot, with possible subfibular impingement and irritation of the peroneal tendon and/or sural nerve. Frequently, the subtalar joint develops posttraumatic arthritis. In symptomatic patients with calcaneal malunion, systematic evaluation is required to determine the source of pain. Nonsurgical treatment, such as activity modification, bracing, orthoses, and injection, is effective in many patients. Surgical treatment may involve simple ostectomy, subtalar arthrodesis with or without distraction, or corrective calcaneal osteotomy. A high rate of successful arthrodesis and of patient satisfaction has been reported with surgical management.

Does alignment in the hindfoot radiograph influence dynamic foot-floor pressures in ankle and tibiotalocalcaneal fusion?

BACKGROUND

The Saltzman-el-Khoury hindfoot alignment view (HAV) is considered the gold standard for assessing the axis from hindfoot to tibia. However, it is unclear whether radiographic alignment influences dynamic load distribution during gait.

QUESTIONS/PURPOSES

We evaluated varus-valgus alignment by the HAV and its influence on dynamic load distribution in ankle and tibiotalocalcaneal (TTC) arthrodesis.

PATIENTS AND METHODS

We clinically assessed 98 patients (ankle, 56; TTC, 42) with SF-36 and American Orthopaedic Foot and Ankle Society (AOFAS) scores, visual hindfoot alignment, HAV angle, and dynamic pedobarography using a five-step method. For comparison, 70 normal feet were evaluated. Minimum followup was 2 years (average, 4.11 years; range, 2-6 years).

RESULTS

The mean HAV angle was -0.8° ± 7.8° for ankle and -1.2° ± 6.9° for TTC arthrodesis. The HAV angle correlated with pedobarographic load distribution (r = 0.35-0.53). Radiographic alignment did not influence SF-36 or AOFAS scores; however, load distribution correlated to qualities of these scores. Visual alignment only predicted the corresponding HAV angle in 48%. To reproduce the dynamic load of healthy subjects, HAV angles of 5° to 10° valgus were needed.

CONCLUSIONS

Visual positioning is inadequate to determine intraoperative positioning and resulted in a varus position with a relatively large SD. The HAV should be used to assess the hindfoot alignment correctly. HAV angles of 5° to 10° valgus are needed to reproduce a physiologic gait pattern.

Total ankle replacement in association with hindfoot fusion

We report the clinical and radiological outcome of total ankle replacement performed in conjunction with hindfoot fusion or in isolation. Between May 2003 and June 2008, 60 ankles were treated with total ankle replacement with either subtalar or triple fusion, and the results were compared with a control group of 288 ankles treated with total ankle replacement alone.

After the mean follow-up of 39.5 months (12 to 73), the ankles with hindfoot fusion showed significant improvement in the mean visual analogue score for pain (p < 0.001), the mean American Orthopaedic Foot and Ankle Society score (p < 0.001), and the mean of a modified version of this score (p < 0.001). The mean visual analogue pain score (p = 0.304) and mean modified American Orthopaedic Foot and Ankle Society score (p = 0.119) were not significantly different between the hindfoot fusion and the control groups. However, the hindfoot fusion group had a significantly lower mean range of movement (p = 0.009) and a higher rate of posterior focal osteolysis (p = 0.04). Both groups showed various complications (p = 0.131) and failure occurring at a similar rate (p = 0.685).

Subtalar or triple fusion is feasible and has minimal adverse effects on ankles treated with total ankle replacement up to midterm follow-up. The clinical outcome of total ankle replacement when combined with hindfoot fusion is comparable to that of ankle replacement alone. Thus, hindfoot fusion should be performed in conjunction with total ankle replacement when indicated.

Overview of subtalar arthrodesis techniques: options, pitfalls and solutions

BACKGROUND

Subtalar arthrodesis (SA) is the preferred treatment for painful isolated subtalar disease. Although results are generally favourable, analysis of current operative techniques will help optimizing this treatment. The aim was to give an overview of SA-techniques and their pitfalls. Possible solutions were identified.

MATERIALS AND METHODS

A literature search was performed for papers that presented SA operative techniques. The general technique was divided into phases: surgical approach, cartilage removal, bone graft selection, hindfoot deformity correction and fixation.

RESULTS

The published series were invariably retrospective reviews of small heterogenous groups of different hindfoot pathologies. The weighted outcome rate for SA was 85% (68-100%) performed in 766 feet and for SA requiring correction of malalignment 65% (36-96%) in 1001 feet. Non-union (weighted percentage 12%), malalignment (18%), and screw removal (17%) were the prevailing late complications.

PITFALLS

The following pitfalls were identified: 1) early complications related to the incisions made in open approaches, 2) insufficient cartilage removal, improper bone graft selection and fixation techniques, all possibly leading to non-union, 3) morbidity caused by bone graft harvesting and secondary screw removal, 4) under- or overcorrection of the hindfoot possibly due to improper intraoperative verification and 5) inadequate assessment of bony fusion.

SOLUTIONS

The review provides solutions to possibly overcome some pitfalls: 1) if applicable use an arthroscopic approach in combination with distraction devices and new burrs, 2) if possible use local bone graft or allografts, 3) use two screws for fixation to prevent rotational micromotion, and 4) improve assessment of operative outcome by application of appropriate assessment of bony fusion and alignment.

CONCLUSION

The review provides practical suggestions to optimize SA-techniques.

Long-term results of in situ subtalar arthrodesis

Isolated subtalar disorders often require subtalar arthrodesis. In this retrospective study of 28 in situ subtalar arthrodeses reviewed with a median follow-up of 56 months (range, 20-115), the authors attempted to detail the outcomes of in situ subtalar fusion, the consequences on adjacent joints and to determine clinical or radiological factors of failure. Clinical evaluation was realised with the AOFAS (American Orthopaedic Foot and Ankle Society) ankle hindfoot score. Radiographic evaluation included assessment of hindfoot alignment, subtalar fusion and arthritic evolution in the adjacent joints. The median functional score was 76.5/94 (range, 36-94). All 28 arthrodeses achieved union. Mild arthritic changes occurred in 43-65% in the different adjacent joints. These changes were not symptomatic. Varus malunion and clinical nonunion seem to be the most important causes of failure.

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.

High union rates and function scores at midterm followup with ankle arthrodesis using a four screw technique

When evaluating the role of ankle arthrodesis in the treatment of severe ankle arthritis, postoperative infection, nonunion, and the development of arthritis at the adjacent joints are major issues when considering treatment alternatives. We evaluated the rate of complications, the functional outcome, and compensatory range of motion at the midtarsal joint at medium-term followup after ankle arthrodesis with four cancellous screws. We performed 94 ankle fusions in 92 patients; 12 patients were lost to followup and eight declined to participate, leaving 72 patients (76%) for evaluation. The minimum followup was 4.8 years (mean, 5.9; range, 4.8-7.8 years). No patient developed a deep infection; three patients developed postoperative hematoma which we operatively drained. Union occurred in 93 of the 94 patients (99%). The sagittal motion at the midtarsal joint averaged 24 degrees . Secondary arthritis of the subtalar and talonavicular joints developed during the followup period in 17% and 11%, respectively. Progression of preexisting arthritis occurred in 13 of 43 patients (30%) at the subtalar joint and five of 26 patients (19%) at the talonavicular joint. None of these patients had fusion of an adjacent joint. The average American Orthopaedic Foot and Ankle Society score increased from 36 preoperatively to 85 at followup. Ankle arthrodesis with screws provides high rates of union, reliable pain relief, and favorable functional medium-term results.

LEVEL OF EVIDENCE

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

Subtalar versus triple arthrodesis after intra-articular calcaneal fractures

Depending upon initial treatment, between 2 and 30% of patients with a displaced intra-articular calcaneal fracture require a secondary arthrodesis. The aim of this study was to investigate the effect of subtalar versus triple arthrodesis on functional outcome. A total of 33 patients with 37 secondary arthrodeses (17 subtalar and 20 triple) with a median follow-up of 116 months were asked to complete questionnaires regarding disease-specific functional outcome (Maryland Foot Score, MFS), quality of life (SF-36) and overall satisfaction with the treatment (Visual Analogue Scale, VAS). Patient groups were comparable considering median age at fracture, initial treatment (conservative or operative), time to arthrodesis, median follow-up, and post-arthrodesis radiographic angles. The MFS score was similar after subtalar versus triple arthrodesis (59 vs. 56 points; P = 0.79). No statistically significant difference was found for the SF-36 (84 vs. 83 points; P = 0.67) and the VAS (5 vs. 6; P = 0.21). Smoking was statistically significantly associated with a non-union (χ(2) = 6.60, P = 0.017). The current study suggests that there is no significant difference in functional outcome between an in situ subtalar or triple arthrodesis as a salvage technique for symptomatic arthrosis after an intra-articular calcaneal fracture. Smoking is a risk factor for non-union.

Is intraoperative pedography helpful in clinical use--preliminary results of 100 cases from a consecutive, prospective, randomized, controlled clinical study

BACKGROUND

The purpose of this study was to assess the clinical use, and to analyze the potential clinical benefit of intraoperative pedography (IP) in a sufficient number of cases in comparison with cases treated without IP.

METHODS

Patients (age 18 years and older) which sustained an arthrodesis and/or correction of the foot and ankle were included.

RESULTS

One hundred cases were included (ankle correction arthrodesis, n=12; subtalar joint correction arthrodesis, n=14; arthrodesis without correction midfoot, n=15; correction arthrodesis midfoot, n=26; correction forefoot, n=33). Fifty-two patients were randomized for the use of IP. In 24 of the 52 patients (46%), the correction was modified after IP during the same operation.

CONCLUSIONS

In 46% of the cases a modification of the surgical correction was made after IP in the same surgical procedure. Whether IP improve the plantar force distribution of the foot and the mid- or long-term clinical outcome has to be critically analyzed when longer follow-up is completed.

Computer Assisted Surgery (CAS) guided arthrodesis of the foot and ankle: an analysis of accuracy in 100 cases

BACKGROUND

Computer Assisted Surgery (CAS) has shown the potential to increase the accuracy of surgical procedures in different fields of orthopedic surgery. The clinical experiences of 100 cases with CAS guided arthrodeses were evaluated.

MATERIALS AND METHODS

Two navigation systems were used (VectorVision/Navivision, Brainlab). Patients with unilateral foot and/or ankle correction arthrodesis from January 1st, 2005 to March 31st, 2008 were included. The correction was planned on the basis of clinical findings, radiographs and computer tomography. Time spent, accuracy, and problems that occurred with CAS guidance were analyzed. The accuracy was assessed by intraoperative three-dimensional imaging with ISO-C 3D or ARCADIS-3D (Siemens). The deviation from the achieved correction in comparison with the planned correction was analyzed.

RESULTS

One hundred patients were included (ankle, n = 19; subtalar, n = 23; ankle and subtalar, n = 12; midfoot/tarsometatarsal (TMT), n = 28, others, n = 18). The average time needed for preparation was 356 seconds (5 minutes, 56 seconds) (range, 4 to 30 minutes), the correction took an average of 28 (range, 12 to 140) seconds. The CAS system encountered malfunctions in 3 procedures (3%). In the remaining cases, all the achieved corrections were within a maximum deviation of 2 degrees/mm when compared to the planned correction (p < 0.05).

CONCLUSION

With CAS guidance for the correction of deformities of the foot and ankle, a surgeon can achieve a high degree of accuracy with a rapid correction. The high accuracy may lead to improved clinical outcomes.

Primary isolated subtalar arthrodesis: outcome after 2 to 5 years followup

BACKGROUND

Favorable to excellent clinical results have been reported for isolated subtalar joint arthrodesis. Pedobarography after subtalar bone-block distraction arthrodesis have demonstrated a more laterally shifted gait line. However pedobarographic measurements after primary in-situ isolated subtalar arthrodesis have not been reported. This is the first study considering this.

MATERIALS AND METHODS

Physical examination, AOFAS Hindfoot score, full weightbearing anterior/posterior and lateral radiographs were assessed in 15 feet. Peak pressures, ground reaction force and force distribution at foot-flat and push-off were measured.

RESULTS

Average AOFAS-Score significantly improved. Subjective satisfaction was high. Non-union was found in 1 foot (7%), screws were removed in 4 of the 15 feet (27%). One new asymptomatic arthritic talonavicular joint was found. The pressure and force distributions under the operated and contralateral foot showed a different pattern compared to a normal foot. Ground reaction force under both the operated and contralateral feet were lower than a normal foot.

DISCUSSION

This study found good clinical, subjective and radiographic results matching that of the reported literature. However, pedobarographic assessment suggests that great functional differences still remain when compared to a normal foot. Subtalar arthrodesis may induce an abnormal gait pattern by preventing compensation of axial rotation of the tibia. This is also reflected in the unaffected side, which may indicate an effort in the general locomotor control to keep a symmetrical gait pattern. This finally alters the pressure and force distribution under both feet. Nevertheless, subtalar arthrodesis is considered a valuable treatment for various isolated subtalar disorders.

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.

In situ arthrodesis with lateral-wall ostectomy for the sequelae of fracture of the os calcis

Distraction bone-block arthrodesis has been advocated for the treatment of the late sequelae of fracture of the os calcis. Between 1997 and 2003 we studied a consecutive series of 17 patients who had in situ arthrodesis for subtalar arthritis after fracture of the os calcis with marked loss of talocalcaneal height. None had undergone any previous attempts at reconstruction. We assessed the range of dorsiflexion and plantar flexion and measured the talocalcaneal height, talocalcaneal angle and talar declination angle on standing lateral radiographs, comparing them with the normal foot. The mean follow-up was for 78.7 months (48 to 94). The mean American Orthopaedic Foot and Ankle Society hindfoot score improved from 29.8 (13 to 48) to 77.8 (48 to 94) (Student's t-test, p < 0.001). The mean loss of talocalcaneal height was 10.3 mm (2 to 17) and the mean talar declination angle was 6.7 degrees (0 degrees to 16 degrees) which was 36% of the normal side. One patient suffered anterior ankle pain but none had anterior impingement. Two patients complained of difficulty in ascending slopes and stairs and four in descending. The mean ankle dorsiflexion on the arthrodesed side was 11.6 degrees (0 degrees to 24 degrees) compared with 14.7 degrees (0 degrees to 24 degrees) on the normal side, representing a reduction of 21.1%. The mean plantar flexion on the arthrodesed side was 35.5 degrees (24 degrees to 60 degrees) compared with 44.6 degrees (30 degrees to 60 degrees ) on the normal side, a reduction of 20.4%. These results suggest that anterior impingement need not to be a significant problem after subtalar arthrodesis for fracture of the os calcis, even when the loss of talocalcaneal height is marked. We recommend in situ arthrodesis combined with lateral-wall ostectomy for all cases of subtalar arthritis following a fracture of the os calcis, without marked coronal deformity, regardless of the degree of talocalcaneal height loss.

Radiographic evaluation of calcaneal fractures: to measure or not to measure

OBJECTIVE

The aim of this study was to correlate the functional outcome after treatment for displaced intra-articular calcaneal fracture with plain radiography.

DESIGN

The design was a prognostic study of a retrospective cohort with concurrent follow-up.

PATIENTS

A total of 33 patients with a unilateral calcaneal fracture and a minimum follow-up of 13 months participated. Patients filled in three disease-specific questionnaires, graded their satisfaction and the indication for an arthrodesis was noted. Standardised radiographs were made of the previously injured side and the normal (control) side. Different angles and distances were measured on these radiographs and compared with values described in the literature. The differences in values in angles and distances between the injured and uninjured (control) foot were correlated with the outcome of the questionnaires, and the indication for an arthrodesis.

RESULTS

None of the angles correlated with the disease-specific outcome scores. Of the angles only the tibiotalar angle correlated with the VAS (r = 0.35, p = 0.045) and only the absolute foot height correlated with the indication for an arthrodesis (odds = 0.70, CI = 0.50-0.99).

CONCLUSION

In this study the radiographic evaluation correlated poorly with the final outcome. Measurements on plain radiographs seem not to be useful in determining outcome after intra-articular calcaneal fractures.

Intraoperative pedography: a validated method for static intraoperative biomechanical assessment

BACKGROUND

A new device was developed to perform intraoperative static pedography. The purpose of this study was to validate the introduced method by a comparison with the standard method for dynamic and static pedography.

METHODS

A device known as Kraftsimulator Intraoperative Pedographie (KIOP) was developed for intraoperative placement of standardized forces to the sole of the foot. Pedographic measurements were done with a custom-made mat that was inserted into the KIOP (Pliance, Novel Inc., St. Paul, MN, USA). Validation was done in two steps: (1) comparison of standard dynamic pedography walking on a platform, standard static pedography in standing on a platform, and pedography with KIOP in supine position in 30 healthy volunteers, and (2) comparison of static pedography in standing position, pedography with KIOP supine awake, and pedography with KIOP supine with 30 patients under anesthesia. Individuals who had operative procedures at the knee or distal to the knee were excluded. The different measurements were compared (one-way ANOVA, t-test; significance level 0.05).

RESULTS

No significant differences were found among all measurements for the hindfoot compared to midfoot-forefoot force distribution. For the medial compared to lateral force distribution and the 10-region-mapping, significant differences were found when comparing all measurements (steps 1 and 2) and when comparing the measurements of step 1 only. No differences were found for these distributions when comparing the measurements of step 2 alone or when comparing the measurements of step 1 and 2 without the platform measurements of step 1 (dynamic walking pedography and static standing pedography). No significant differences in the force distributions were found in step 2 when comparing subjects without anesthesia, with general anesthesia, and with spinal anesthesia.

CONCLUSIONS

The KIOP device allows a valid static intraoperative pedography measurement. No statistically significant force distribution differences were found between standing subjects and anesthetized subjects in the supine position.

Factors associated with outcome after subtalar arthrodesis

OBJECTIVES

To evaluate radiographic and functional outcomes after subtalar arthrodesis and to identify patient factors associated with poor outcome.

DESIGN

Retrospective study.

SETTING

Two academic hospitals.

PATIENTS

Eighty-eight patients with primary or secondary osteoarthritis treated between 1995 and 2002.

INTERVENTION

Primary subtalar arthrodesis.

MAIN OUTCOME MEASUREMENTS

Radiographic outcome was assessed by determining union rates. Functional outcome was assessed through self-administered questionnaires (Short Form-36, Short Musculoskeletal Function Assessment, and the AAOS Foot and Ankle Instrument).

RESULTS

After adjusting for age and sex smokers were 3.8 times more likely to go on to nonunion than nonsmokers (P < 0.05). As patients aged, there was a higher likelihood of nonunion if they also smoked (P < 0.05). Of patients undergoing subtalar bone block distraction arthrodesis 95% went on to union compared with 65% of patients treated with an in situ subtalar arthrodesis without bone graft (P < 0.05). There was a trend for higher rates of union if a bone graft was used among patients treated with an in situ subtalar arthrodesis. Diabetic patients were 18.7 times more likely to have a malunion (P < 0.05). As a group, patients who have undergone subtalar arthrodesis can expect significantly worse functional outcomes compared with the Canadian and American normative populations. The poorest functional outcomes were observed among patients with diabetes. A trend for poorer outcome in bodily pain and general health (Short Form-36) was seen in workers' compensation patients.

CONCLUSIONS

Certain patient variables are associated with poorer outcomes after subtalar fusion. The results of this study will enable surgeons to provide better information to patients in preoperative discussions with respect to patient expectations, outcomes, and the success of surgery.

Post-calcaneus fracture reconstruction

This article outlines the pathoanatomy of malunited calcaneal fractures and reviews the literature on resulting painful sequelae, diagnostic work-up, as well as reconstructive treatment options and their outcome.

Reconstruction after talar fractures

Malunited and nonunited talar fractures cause significant disability. Distinction between partial and total avascular necrosis (AVN) determines the choice of treatment. Patients who have minimal or no AVN and well-preserved joint cartilage may be amenable to corrective osteotomy through the malunited fracture or removal of the pseudoarthrosis. Secondary reconstruction with joint preservation leads to considerable functional improvement in painful talar malunions and nonunions in reliable patients. If symptomatic arthritis is present, arthrodeses and correction of deformity through the fusion or with additional osteotomies provide predictable results, although they do not restore normal foot function. Fusions should be limited to the affected joint. If the subtalar joint shows severe arthritic changes, every attempt should be made to salvage the ankle and talonavicular joints.

Die posttraumatische Arthrose am Rückfuß

Posttraumatic arthritis of the joint components of the hind foot is typically linked with hind foot deformity and involvement of the neighbouring joint. The principal goals of any hind foot reconstruction are to achieve a quasi-anatomical reconstruction of the geometry and a stable and plantigrade foot position as a prerequisite for acceptable gait function, and an overall satisfactory result for the patient. Profound knowledge of the functions of the ankle-hind foot complex is the basis for the development of a valid therapeutic strategy. Any surgical reconstruction has to consider previous interventions, local soft tissue conditions, neurovascular status, and the components of deformity and degree of arthritic destruction at the corresponding joint levels. In general, an arthrodesis of any hind foot joint, as a key element in hind foot reconstruction, will be successful if correction of the underlying deformity is also adequately addressed.

[Clinical gait analysis]

Clinical gait analysis comprises a well defined repertoire of various methods for valid and reliable assessment. The rapid development of corresponding hardware and software has substantially decreased the efforts necessary for data processing and has promoted the clinical applicability of the procedures. The clinical question defines the amount of methodological input. Clinical gait analysis may provide diagnostic insight into the pathobiomechanics and the pathophysiology of complex gait disorders for which a profound understanding of the underlying causes is a prerequisite for adequate treatment. The methods may help in the screening of gait function following reconstructive surgery as a measure of quality control, the assessment of the severity of a gait disturbance, the evaluation of a rehabilitation process, or the quantification of the effect of orthoses, insoles or specific shoe ware. Simple procedures of gait analysis may suffice to obtain information on gait function which can not be derived by mere clinical observation and which can be incorporated into a clinical concept.