The effect of fibular malreduction on contact pressures in an ankle fracture malunion model

Management of syndesmosis injuries in the elite athlete

This article reviews the basics and evidence base thus far on syndesmosis injuries, focusing on its management in the elite sporting population. A syndesmosis injury or "high ankle sprain" is a significant injury, especially in the elite athlete. Among all ankle sprains, the syndesmotic injury is most predictive of persistent symptoms in the athletic population. Late diagnosis of unstable syndesmosis injuries leads to a poor outcome and delayed return to sports. A high index of suspicion and an understanding of the mechanism of injury is required to ensure an early diagnosis. Incomplete/inaccurate reduction leads to a poor outcome.

Aftercare following syndesmotic screw placement: a systematic review

For ankle fractures, in general, several studies have been published on immobilization (e.g., cast or boot) versus early motion after surgical treatment. However, no studies have been performed to determine the best aftercare strategy for surgically treated patients with ankle fractures with concomitant acute distal tibiofibular syndesmotic injuries. The aim of the present review was to compare the functional outcomes of ankle fractures with syndesmotic injury treated with a cast or boot versus early motion. We performed a systematic review using the electronic databases from January 1, 2000 to September 1, 2012 of the Cochrane Library, PubMed MEDLINE(®), EMbase, and Google Scholar. The included studies were those in which ankle fractures with acute distal tibiofibular syndesmotic injuries had been treated with 1 or more syndesmotic screws, with a mean follow-up period of at least 12 months and at least 25 patients included. The functional outcomes, measured using the American Orthopaedic Foot Ankle Society Hindfoot scale, Olerud-Molander Ankle Scale, and Short Musculoskeletal Function Assessment, were compared. A total of 9 studies were identified with a total of 531 patients. The number of included patients ranged from 28 to 93. The mean follow-up period was 12 to 101 months. Of the 9 studies, 3 used an early motion protocol (195 patients) and 6 (336 patients) a protocol of immobilization for at least 6 weeks. For the American Orthopaedic Foot Ankle Society Hindfoot scale, the mean scores for immobilization were 86 to 91 points and for early motion, 84 to 89. For the Olerud-Molander Ankle Scale, the scores for immobilization were 47 to 90 and for early motion, 46 to 82 points. The Short Musculoskeletal Function Assessment score for immobilization was 11 and for early motion ranged from 12 to 27 points. No apparent differences could be detected in the published data considering the functional outcomes between immobilization versus an early motion protocol in ankle fractures with acute distal tibiofibular syndesmotic injuries treated with a syndesmotic screw. However, level 1 and 2 studies on this subject are lacking.

Realignment-lengthening osteotomy for malunited distal fibular fracture

PURPOSE

Persistent displacement of ankle fractures increases the stresses on the articular cartilage and leads to degenerative arthritis. Correction of the ankle mortise restores the normal ankle biomechanics and should prevent the development of degenerative joint disease.

METHODS

Seventeen patients were treated for symptomatic ankle joint due to malunited distal fibular fracture. There were eleven male and six female patients. Their ages ranged from 23 to 54 years (median 34 years). The procedure included transverse fibular osteotomy for restoration of the lateral malleolar alignment, acute distraction of the osteotomy to restore the fibular length with interpositional graft and reduction of subluxation of the distal tibio-fibular articulation. Internal fixation of the osteotomy was performed with plate and screws and trans-syndesmotic screws.

RESULTS

Fibular lengthening was performed in all cases and ranged from six to 12 mm (median eight millimetres). The American Orthopaedic Foot and Ankle Society score preoperatively ranged from 40 to 74 (median 60) and at follow up ranged from 50 to 95 (median 79). Progression of ankles arthrosis occurred in one patient leading to ankle arthrodesis as a secondary procedure. Results were satisfactory in 12 cases (70.6%), and unsatisfactory in five cases (29.4%) due to stiffness and pain in the ankle joint. The follow-up ranged from 24 to 45 months (median 31 months).

CONCLUSION

Corrective osteotomy of fibular malunion produces considerable improvement provided that the patient does not have significant degenerative changes before surgery. The use of athrodiastasis of the ankle as a secondary procedure may be of value to improve the outcome.

Stabilization of the syndesmosis in the Maisonneuve fracture--a biomechanical study comparing 2-hole locking plate and quadricortical screw fixation

OBJECTIVE

The aim of this study is to determine whether a 2-hole locking plate has biomechanical advantages over conventional screw stabilization of the syndesmosis in this injury pattern.

METHODS

Six pairs of fresh-frozen human cadaver lower legs were prepared to simulate an unstable Maisonneuve fracture. Each limb was compared with its pair; the syndesmosis in one being stabilized with two 4.5-mm quadricortical cortical screws, the other a 2-hole locking plate with 3.2-mm locking screws. The limbs were then mounted on a servohydraulic testing rig and axially loaded to a peak load of 800N for 12000 cycles. Fibula shortening and diastasis were measured. Each limb was then externally rotated until failure occurred. Failure was defined as fracture of bone or metalwork, syndesmotic widening, or axial migration >2 mm.

RESULTS

Both constructs effectively stabilized the syndesmosis during the cyclical loading within 0.1 mm of movement. However, the locking plate group demonstrated greater resistance to torque compared with quadricortical screw fixation (40.6 Nm vs. 21.2 Nm, respectively, P value < 0.03).

CONCLUSION

A 2-hole locking plate (with 3.2-mm screws) provides significantly greater stability of the syndesmosis to torque when compared with 4.5-mm quadricortical fixation.

Managing the cystic osteochondral defect: allograft or autograft

Osteochondral lesions of the talus are generally benign, and many heal or are not symptomatic. A subset of these defects progress to large cystic lesions, which have a less favorable prognosis. The treatment options are joint preservation or sacrifice. Joint salvage entails marrow stimulation techniques or hyaline cartilage replacement with allograft or autograft. When lesions reach greater than 3 cm(2) or Raikin class IV or become uncontained on the shoulders of the talus, autografting techniques become more challenging. Osteochondral allografting may be a better surgical option, often achievable without a malleolar osteotomy for exposure.

Operative exploration and reduction of syndesmosis in Weber type C ankle injury

OBJECTIVE:

To investigate the surgical methods in treating Weber type C ankle injury and estimate the necessity of syndesmosis operative exploration.

METHODS:

Forty three patients of Weber type C ankle injury were treated with open reduction and internal fixation from October 2004 to December 2009. Twenty nine patients were treated with routine procedure by open reduction and internal fixation, syndesmosis exploration and repair were performed in addition in the others. Thirty four patients were followed during an average time of 31.2 months (range 18 to 50 months), amomg them 22 patients were treated with routine procedures and 12 were treated with additional syndesmosis surgical exploration.

RESULTS:

All the fractures were reunited in an average time of 13.1 weeks (range 10 to 18 weeks) and full weight bearing began. The mean ankle and hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS) score was 79.86(range 65 to 98) in the routine procedures group and 86.67 (range 78 to 100) in the syndesmosis exploration group and Olerud-Molander score was 77.27 (range 55 to 100) and 86.67 (range 75 to 100) respectively. Statistically significant difference was found between the two groups (P<0.05).

CONCLUSION:

Syndesmosis surgical exploration is an essential treatment in some Weber type C ankle injuries, which make debridement and direct reduction of the syndesmosis possible, providing thus a more stabilized ankle joint. Level of Evidence III, Retrospective Comparative Study

Using a cervical spine cage to reconstruct malunited fibular fractures

PURPOSE

Anatomical reduction and fixation of unstable ankle fractures is necessary to prevent post-traumatic arthritis. Malunion of the distal fibula in unstable ankle fractures can lead to late degenerative changes of the ankle. Late reconstruction of the ankle can improve its function and postpone the need for ankle fusion or replacement.

METHODS

We discuss three patients who presented with fibular malunion. All developed medial gutter opening, syndesmotic widening, and lateral shift and/or talar tilt. Surgery involved an anteromedial approach to clean the medial gutter, an anterolateral approach to clean the syndesmotic interval, elongation of the fibula by six to eight millimetres and stabilisation with a cervical spine cage and a locked plate.

RESULTS

After one year, all patients had radiologically demonstrated reduction of the talus in the mortise. Improved function was recorded at final follow up. The cage provides several advantages over other fixation methods, including osteoconductive properties, avoiding bone graft donor site morbidity, and the range of sizes allows the surgeon to adjust the amount of elongation.

CONCLUSIONS

Using spinal cages to treat malunited fibula fractures has several advantages compared to bone graft and good results can be expected.

Distal fibular lengthening after premature growth arrest: a case report

Post-traumatic premature closure of the distal fibular growth plate is a rare entity leading to shortening of the lateral malleolus. We report on a 14-year old boy who presented with a 4-year history of worsening, diffuse discomfort and swelling of his left ankle, as well as fibular shortening and talar malreduction. He had sustained a distal tibial fracture 4 years earlier and had been treated with closed reduction. He reported instability of the ankle and difficulty with running. There was 1-cm shortening of the left fibula, 1-cm shortening of the proximal fibula, and slight widening of the medial clear space. Both tibial and fibular growth plates were already closed and the left ankle joint space was slightly narrowed. He was treated with late fibular lengthening and autogenous iliac crest tricortical bone grafting and achieved anatomic restoration of the distal tibiofibular relationship. At one-year follow-up, the ankle-hindfoot score had improved from 69 to 100.

Anatomic location and morphology of symptomatic, operatively treated osteochondral lesions of the talus

BACKGROUND

Historically, osteochondral lesions of the talus (OCLTs) were thought to occur most commonly in the anterolateral and posteromedial talar dome; however, new classification systems are able to describe OCLT location more precisely. A recent magnetic resonance imaging (MRI) study introduced a novel nine-zone anatomic grid of the talar dome, demonstrating that most OCLTs occur in the central portion of the medial and lateral talar dome, with medial lesions being more common as well as larger in depth and surface area. The current study sought to determine if similar location and morphology patterns were consistent in symptomatic, operatively treated OCLTs.

MATERIALS AND METHODS

The preoperative MRI images of 65 consecutive patients who underwent operative management for symptomatic OCLTs at a single institution were reviewed using a previously described nine-zone anatomic grid of the talar dome to determine location frequency, morphology, and Hepple et al. MRI staging classification characteristics. All patients were active-duty service members in the United States Armed Forces. The cohort consisted of 60 (92%) males and 5 (8%) females with an overall mean patient age of 34 (range, 19 to 58) years. Statistical analyses were performed, and significant differences are reported.

RESULTS

The most common location for symptomatic, operatively treated OCLTs was the central third of the lateral talar dome, followed by the central third of the medial talar dome. Anterolateral and posteromedial lesions accounted for relatively few OCLTs. Compared with lateral OCLTs, medial OCLTs were significantly larger in transverse and anteroposterior diameters and surface area, but no significant differences existed with regard to lesion depth. Overall, the majority of lesions were MRI stage II; however, stage II lesions were more likely located laterally, whereas stage III lesions were more likely located medially.

CONCLUSIONS

With regard to symptomatic, operatively treated OCLTs, the results of the current study parallel current evidence that posteromedial and anterolateral OCLTs are not the most common locations of OCLTs. As well, medial OCLTs were larger in surface area than lateral OCLTs, but no differences existed with regard to lesion depth. It is interesting that operatively treated OCLTs were twice as commonly located in the centrolateral third rather than the centromedial third of the talar dome.

The functional consequence of syndesmotic joint malreduction at a minimum 2-year follow-up

OBJECTIVE

To examine the correlation between syndesmotic malreduction and functional outcome.

DESIGN

Prospective evaluation of bilateral computed tomography scans and functional outcome scores.

SETTING

Level I regional trauma center.

MATERIALS AND METHODS

From January 1, 2004, to December 31, 2006, 107 of 681 operatively treated ankle fractures (15.7%) had associated syndesmotic injuries requiring reduction and fixation. All patients available at a minimum of 2 years postindex procedure underwent clinical and radiographic examination, computed tomographic (CT) scanning of both ankles (injured and uninjured), and functional outcome scoring using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires.

RESULTS

Sixty-eight of 107 (63.5%) syndesmotic injuries in 68 patients were available for follow-up. Twenty-seven (39%) were malreduced (rotational or translational asymmetry) when compared with the contralateral uninjured syndesmotic joint. Fifteen percent of the open syndesmotic reductions were malreduced on postoperative CT scans, whereas 44% (A/B) of the closed syndesmotic reductions were malreduced on postoperative CT scan (P = 0.11). Patients with a malreduced syndesmosis recorded significantly worse functional outcome scores (P < 0.05) on both the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires when compared with those patients whose syndesmosis had healed in anatomic alignment.

CONCLUSIONS

At a minimum of 2 years follow-up, patients with malreduced syndesmotic injuries demonstrated significantly worse functional outcome using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires. Open reduction of the syndesmosis resulted in a substantially lower rate of malreduction when evaluated by postoperative CT scan. Based on these findings, we recommend that surgeons not only perform a direct, open visualization of the syndesmosis during the reduction maneuver, but obtain a postoperative CT scan with comparison to the contralateral extremity as well. If the syndesmosis is found to be malreduced, consideration must be given to revising the osteosynthesis.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Triplane and Tillaux fractures: is a 2 mm residual gap acceptable?

Children's ankle fractures are the second most common growth plate fractures in humans and one of the top 10 reasons for pediatric orthopaedic hospital admissions. Because triplane and Tillaux fractures occur during the period of distal tibial physeal closure, they are considered transitional injuries. The distal tibial physis closes in a unique, asymmetric pattern (middle, then medial, and finally lateral), and it is the portion of the physis that is open at the time of injury that is vulnerable to fracture in this age group. Triplane and Tillaux fractures occur after supination external rotation and compression stress with unpredictable multiplanar fracture patterns. The fracture may appear different on different x-ray projections, making computed tomography mandatory to determine the number of fragments. Because most of these fractures are intra-articular, anatomic or near-anatomic reduction of the joint surface is recommended to minimize future posttraumatic ankle arthritis. Because these fractures occur at the end of growth, they rarely result in growth arrest.

[Causes of failed osteosynthesis of ankle fractures]

Ankle fractures are the most common osseous injuries of the lower extremity. In most cases, open reduction and internal fixation is indicated due to fracture dislocation. Operations of the ankle are generally considered classic, standardized, training procedures. An exact reconstruction with correct length and rotation of the joint as well as stabilization of the tibiofibular ligamentous complex is essential. Beside age and gender of the patient, outcome depends on fracture morphology and comorbidities, e. g., osteoporosis, vascular status, neuropathic disorders, and diabetes mellitus. Additional chondral lesions, extensive closed or open soft tissue injuries, and compartment syndrome due to trauma impact can lead to further problems in the postoperative period. Furthermore, iatrogenic complications like fixed malpositions, instabilities, and implant-associated failure of osteosynthesis may also occur. This article illustrates the causes of preventable mistakes and points out options to increase clinical outcome.

Ankle fractures

Ankle fractures are important injuries involving a weight-bearing joint critical to mobility. This article will discuss the necessity of and justification for surgical correction of virtually all ankle fractures. Various ankle fracture types will be explored, mechanisms illuminated and proper treatment outlined for these complex injuries.

The isolated lateral malleolar fracture: where are we and how did we get here?

Despite the isolated lateral malleolar ankle fracture being one of the most common injuries treated by orthopaedic surgeons it remains an injury that is widely misunderstood. Treatment protocols are compounded by the contemporary literature being divided on its optimal management. This review takes the reader through a process of how the historical literature on this subject has been formed, it critiques the main responsible papers and leads one to question the current dogma attached to both this injury and to current research in general.

Treatment of posttraumatic varus ankle deformity with supramalleolar osteotomy

Supramalleolar osteotomies for correction of posttraumatic varus arthritis in early and mid-stages provide good functional and clinical outcomes. However, the biomechanical behavior of the ankle joint differs from the knee, and therefore correction of the distal TAS angle alone may not provide a physiologic load transfer across the ankle joint. Osseous balancing of an arthritic varus ankle joint may require not only correction of the articular surface angle in the frontal plane but may include a biplanar correction to improve the talar coverage and a fibular osteotomy to restore ankle joint congruency.

Operative versus nonoperative treatment of unstable lateral malleolar fractures: a randomized multicenter trial

OBJECTIVES

To compare clinical and functional outcomes after operative and nonoperative treatment of undisplaced, unstable, isolated fibula fractures.

DESIGN

Randomized multicenter clinical trial.

SETTING

Six level 1 trauma centers.

PATIENTS/PARTICIPANTS

Eighty-one patients with undisplaced, unstable, isolated fibula fractures as confirmed by an external rotation stress examination demonstrating an increase in medial clear space to 5 mm or greater were followed for 12 months after treatment.

INTERVENTION

Forty-one patients were treated operatively by open reduction and internal fixation of the fibula. Forty patients underwent nonoperative treatment, which included the use of a short leg cast or brace and protected weight bearing for 6 weeks.

MAIN OUTCOME MEASUREMENTS

Functional outcomes determined using the Olerud-Molander Ankle Score and the Short Form 36. Radiographic outcomes included measurement of union and displacement at each visit.

RESULTS

There were no statistically significant differences in functional outcome scores or pace of recovery between the operative and nonoperative groups at any time interval (β = -0.28, 3.49; P = 0.936). Complications in the nonoperative group included 8 patients with a medial clear space ≥5 mm and 8 patients with delayed union or nonunion. In the operative group, 5 patients had a surgical site infection and 5 patients required hardware removal.

CONCLUSIONS

Patients managed operatively had equivalent functional outcomes compared with nonoperative treatment; however, the risk of displacement and problems with union was substantially lower in patients managed with surgery.

Anterior distal tibia plafondplasty for exposure of the talar dome

BACKGROUND

It may be possible to avoid malleolar osteotomy for treatment of osteochondral talar lesions with chondrocyte transplantation techniques, where perpendicular approach to the talar surface is not required. We hypothesized that limited anterior distal tibial plafondplasty would allow access to most of the talar surface. We compared talar access with soft tissue exposure versus plafondplasty.

METHODS

Two soft tissue exposures (anteromedial and anterolateral) and two limited anterior distal tibial plafondplasties (anteromedial and anterolateral) were used on 12 cadaver lower-extremity specimens. Digital analysis was used to assess the accessible area.

RESULTS

Percentage of total talar dome surface area access increased significantly between soft tissue exposure and limited plafondplasty medially (22.3 +/- 6.3% versus 37.9 +/- 4.6%; p < 0.001) and laterally (22.4 +/- 7.7% versus 37.9 +/- 7.7%; p < 0.001). Percentage sagittal plane access also increased significantly between soft tissue exposure and limited plafondplasty medially 54.4 +/- 12.0% versus 81.3 +/- 9.7%; p < 0.001) and laterally (53.3 +/- 14.5% versus 80.9 +/- 12.8%; p < 0.001). Limited exposure to an additional 14.2 +/- 5% of the total talar surface area was possible. The posterior 10.6 +/- 8% was inaccessible.

CONCLUSIONS

A soft tissue approach with limited plafondplasty provided adequate exposure for the majority of the medial and lateral talar surface. Only the central posterior 10% of the talus was not accessed by this method.

CLINICAL RELEVANCE

It may be possible to avoid malleolar osteotomy by using limited plafondplasty to access the talar dome for treatment of osteochondral lesions if perpendicular access to the talus is not required.

Effect of graft height mismatch on contact pressures with osteochondral grafting of the talus

BACKGROUND

Osteochondral allograft transplantation is technically demanding. It is not always possible to place the surface of the graft perfectly flush with the surrounding cartilage. One must often choose between placing at least some portion of the surface of the graft slightly elevated or recessed. The effect of this choice on joint contact pressure is unknown.

PURPOSE

This study was undertaken to determine the effect of graft height mismatch on joint contact pressure in the ankle.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten human cadaveric ankles underwent osteochondral grafting by removal then replacement of an osteochondral plug. Six conditions were tested: intact, graft flush, graft elevated 1.0 mm, graft elevated 0.5 mm, graft recessed 0.5 mm, and graft recessed 1.0 mm. Joint contact pressures were measured with a Tekscan sensor while loads of 200 N, 400 N, 600 N, and 800 N were sequentially applied.

RESULTS

The peak contact pressure at the graft site for the flush condition was not significantly different from the intact condition for either medial or lateral lesions. In contrast, peak pressure on the opposite facet of the talar dome was significantly increased during the flush condition for the medial but not the lateral grafts. Elevated grafts experienced significantly increased contact pressures, whereas recessed grafts experienced significantly decreased pressures. These changes were greater for lateral than for medial lesions. Reciprocal changes in joint contact pressures were found on the opposite facet of the talus with elevated grafts on the lateral side and recessed grafts on the medial side.

CONCLUSION

Flush graft placement can restore near-normal joint contact pressure. Elevated graft placement leads to significant increases in joint contact pressure at the graft site. Recessed graft placement leads to a transfer of pressure from the graft site to the opposite facet of the talus.

CLINICAL RELEVANCE

Osteochondral grafts in the talus should be placed flush if possible or else slightly recessed.

Corrective supramalleolar osteotomy for malunited pronation-external rotation fractures of the ankle

We undertook a prospective study to analyse the outcome of 48 malunited pronation-external rotation fractures of the ankle in 48 patients (25 females and 23 males) with a mean age of 45 years (21 to 69), treated by realignment osteotomies. The interval between the injury and reconstruction was a mean of 20.2 months (3 to 98).

In all patients, valgus malalignment of the distal tibia and malunion of the fibula were corrected. In some patients, additional osteotomies were performed. Patients were reviewed regularly, and the mean follow-up was 7.1 years (2 to 15).

Good or excellent results were obtained in 42 patients (87.5%) with the benefit being maintained over time. Congruent ankles without a tilted talus (Takakura stage 0 and 1) were obtained in all but five cases. One patient required total ankle replacement.

Malreduction of syndesmosis--are we considering the anatomical variation?

Previous studies have demonstrated the need for accurate reduction of ankle syndesmosis. Measurement of syndesmosis is difficult on plain radiographs. A computed tomography (CT) scan allows better visualisation of the transverse relationship between the fibula and incisura fibularis. The difference ('G' a term we coined for ease of description) between the fibula and the anterior and posterior facets of the incisura fibularis was compared between normal and injured ankles following syndesmotic fixation in 19 patients. The mean diastasis (MD) was also calculated, representing the average measurement between the fibula and the anterior and posterior incisura. When compared with the normal side, eight out of 19 (42%) cases were found to have a residual diastasis even after fixation across the syndesmosis. However, if a standard value of G (2mm) was used for the injured leg only, all of the 19 cases would have abnormal values of 'G' following reduction. Our study has clearly demonstrated the need for individualising the assessment method to guide surgeons and radiologists prior to revision surgery. A standard value of 'G' of 2mm as the normal limit cannot be applied universally, as apparent from the data presented in this study.

The role of the fibula in varus and valgus deformity of the tibia: a biomechanical study

It has been suggested that a supramalleolar osteotomy can return the load distribution in the ankle joint to normal. However, due to the lack of biomechanical data, this supposition remains empirical. The purpose of this biomechanical study was to determine the effect of simulated supramalleolar varus and valgus alignment on the tibiotalar joint pressure, in order to investigate its relationship to the development of osteoarthritis. We also wished to establish the rationale behind corrective osteotomy of the distal tibia. We studied 17 cadaveric lower legs and quantified the changes in pressure and force transfer across the tibiotalar joint for various degrees of varus and valgus deformity in the supramalleolar area. We assumed that a supramalleolar osteotomy which created a varus deformity of the ankle would result in medial overload of the tibiotalar joint. Similarly, we thought that creating a supramalleolar valgus deformity would cause a shift in contact towards the lateral side of the tibiotalar joint. The opposite was observed. The restricting role of the fibula was revealed by carrying out an osteotomy directly above the syndesmosis. In end-stage ankle osteoarthritis with either a valgus or varus deformity, the role of the fibula should be appreciated and its effect addressed where appropriate.

The taylor spatial frame™ for correction of neglected fracture dislocation of the ankle

Treatment of neglected fracture dislocations of the ankle poses a surgical challenge. Extensive open reduction can frequently be contraindicated because of local skin conditions and contractures. The Taylor Spatial Frame™ (TSF) has been used to reduce and maintain reduction of complex fractures. Its use in fracture dislocation of the ankle joint has not been described. We describe a case where a TSF was used to reduce and treat a 6-week-old fracture dislocation of the ankle. The TSF is a versatile device, which has a role in the management of both acute and neglected fractures.

Effect of supramalleolar varus and valgus deformities on the tibiotalar joint: a cadaveric study

BACKGROUND

Distal tibia coronal plane malalignment predisposes the ankle joint to asymmetric load. The purpose of this cadaveric study was to quantify changes in pressure and force transfer in an ankle with a supramalleolar deformity.

MATERIALS AND METHODS

Seventeen cadaveric lower legs were loaded with 700 N after creating supramalleolar varus and valgus deformities. The fibula was left intact in 11 specimens and osteotomized in six. Tekscan© sensors were used to measure the tibiotalar pressure characteristics.

RESULTS

In isolated supramalleolar deformity, the center of force and peak pressure moved in an anteromedial direction for valgus and posterolateral direction for varus deformities. The change was in an anteromedial direction for varus and in a posterolateral direction for valgus deformities in specimens with an osteotomized fibula.

CONCLUSION

Two essentially different groups of varus and valgus deformities of the ankle joint need to be distinguished. The first group is an isolated frontal plane deformity and the second group is a frontal plane deformity with associated incongruency of the ankle mortise.

CLINICAL RELEVANCE

Our findings underline the complexity of asymmetric osteoarthritis of the ankle joint. In addition, results from this study provide useful information for future basic research on coronal plane deformity of the hindfoot and for determining appropriate surgical approaches.

Reconstructive osteotomy of fibular malunion: review of the literature

The treatment of ankle fractures has a primary goal of restoring the full function of the injured extremity. Malunion of the fibula is the most common and most difficult ankle malunion to reconstruct. The most frequent malunions of the fibula are shortening and malrotation resulting in widening of the ankle mortise and talar instability, which may lead to posttraumatic osteoarthritis. The objective of this article is to review the literature concerning the results of osteotomies for correcting fibular malunions and to formulate recommendations for clinical practice. Based on available literature, corrective osteotomies for fibular malunion have good or excellent results in more than 75% of the patients. Reconstructive fibular osteotomy has been recommended to avoid or postpone sequela of posttraumatic degeneration, an ankle arthrodesis or supramalleolar osteotomy. The development of degenerative changes is not fully predictable; therefore, it is advisable to reconstruct a fibular malunion soon after the diagnosis is made and in presence of a good ankle function. Recommendations were made for future research because of the low level of evidence of available literature on reconstructive osteotomies of fibular malunions.

Novel metallic implantation technique for osteochondral defects of the medial talar dome. A cadaver study

BACKGROUND AND PURPOSE

A metallic inlay implant (HemiCAP) with 15 offset sizes has been developed for the treatment of localized osteochondral defects of the medial talar dome. The aim of this study was to test the following hypotheses: (1) a matching offset size is available for each talus, (2) the prosthetic device can be reproducibly implanted slightly recessed in relation to the talar cartilage level, and (3) with this implantation level, excessive contact pressures on the opposite tibial cartilage are avoided.

METHODS

The prosthetic device was implanted in 11 intact fresh-frozen human cadaver ankles, aiming its surface 0.5 mm below cartilage level. The implantation level was measured at 4 margins of each implant. Intraarticular contact pressures were measured before and after implantation, with compressive forces of 1,000-2,000 N and the ankle joint in plantigrade position, 10 dorsiflexion, and 14 plantar flexion.

RESULTS

There was a matching offset size available for each specimen. The mean implantation level was 0.45 (SD 0.18) mm below the cartilage surface. The defect area accounted for a median of 3% (0.02-18) of the total ankle contact pressure before implantation. This was reduced to 0.1% (0.02-13) after prosthetic implantation.

INTERPRETATION

These results suggest that the implant can be applied clinically in a safe way, with appropriate offset sizes for various talar domes and without excessive pressure on the opposite cartilage.

Tri-ligamentous reconstruction of the distal tibiofibular syndesmosis: a minimally invasive approach

The distal tibiofibular syndesmosis provides stability to the ankle mortise, and it is composed of the anterior inferior tibiofibular, posterior inferior tibiofibular, interosseous, and inferior transverse tibiofibular ligaments and the interosseous membrane. Subacute or chronic syndesmosis injuries can present after missed diagnosis in the acute period or after failed or inadequate nonoperative management. It can result in chronic ankle pain and progressive degeneration of the ankle. Reconstructive options for chronic syndesmosis disruption include arthroscopic debridement and screw fixation, arthrodesis of the syndesmosis, advancement of the anterior tibiofibular ligament, reconstruction of the interosseous and anterior inferior tibiofibular ligament, or tri-ligamentous reconstruction of the syndesmosis. We describe a minimally invasive technique of nearly anatomical reconstruction of the 3 syndesmotic ligaments. The syndesmosis is debrided and reduced under arthroscopic guidance and anatomical reduction of the syndesmosis can be achieved. Although we describe this technique for surgeons to consider, we recognize that a thorough clinical review of the method, complete with objective and subjective clinical outcome measurements, is warranted before widespread use of the technique.

Osteochondral defects in the ankle: why painful?

Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage.

The basic science of the subchondral bone

In the past decades, considerable efforts have been made to propose experimental and clinical treatments for articular cartilage defects. Yet, the problem of cartilage defects extending deep in the underlying subchondral bone has not received adequate attention. A profound understanding of the basic anatomic aspects of this particular site, together with the pathophysiology of diseases affecting the subchondral bone is the key to develop targeted and effective therapeutic strategies to treat osteochondral defects. The subchondral bone consists of the subchondral bone plate and the subarticular spongiosa. It is separated by the cement line from the calcified zone of the articular cartilage. A variable anatomy is characteristic for the subchondral region, reflected in differences in thickness, density, and composition of the subchondral bone plate, contour of the tidemark and cement line, and the number and types of channels penetrating into the calcified cartilage. This review aims at providing insights into the anatomy, morphology, and pathology of the subchondral bone. Individual diseases affecting the subchondral bone, such as traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis are also discussed. A better knowledge of the basic science of the subchondral region, together with additional investigations in animal models and patients may translate into improved therapies for articular cartilage defects that arise from or extend into the subchondral bone.

Plantar flexion influences radiographic measurements of the ankle mortise

BACKGROUND

The treatment of ankle fractures often depends on the integrity of the deltoid ligament. Diagnosis of a deltoid ligament tear depends on the measurement of the medial clear space. We sought to evaluate the impact of ankle plantar flexion on the medial clear space.

METHODS

Mortise radiographs were made for twenty-five healthy volunteers, with the ankle in four positions of plantar flexion (0 degrees, 15 degrees, 30 degrees, and 45 degrees). Four observers measured the medial clear space and the superior clear space on each radiograph. The mean medial clear space at 0 degrees was defined as the control, and the deviation of the medial clear space from the control value was calculated at 15 degrees, 30 degrees, and 45 degrees of plantar flexion. The ratio of the medial clear space to the superior clear space was determined on all radiographs, and ratios that were false-positive for a deltoid ligament injury were identified.

RESULTS

Fourteen male and eleven female volunteers were evaluated. The average increase in the medial clear space when ankle plantar flexion was increased from 0 degrees to 45 degrees was 0.38 mm (95% confidence interval, 0.18 to 0.58 mm). This increase was significant (p = 0.005). The average increase in the medial clear space was 0.04 mm when ankle plantar flexion was increased from 0 degrees to 15 degrees and 0.22 mm when it was increased from 0 degrees to 30 degrees. Neither of these changes was significant (p = 0.99 and 0.20). The prevalence of false-positive findings of deltoid injury based on the ratio of the medial clear space to the superior clear space increased as ankle plantar flexion increased, but this increase did not reach significance in our study group (p = 0.18).

CONCLUSIONS

Plantar flexion of the ankle produces changes in radiographic measurements of the medial clear space. The potential for false-positive findings of deltoid disruption increases with increasing ankle plantar flexion.

Cartilage lesions and the development of osteoarthritis after internal fixation of ankle fractures: a prospective study

BACKGROUND

The role of the location and severity of the initial cartilage lesions associated with an ankle fracture in the development of posttraumatic osteoarthritis has not been established, to our knowledge.

METHODS

We performed a long-term follow-up study of a consecutive, prospectively included cohort of 288 ankle fractures that were treated operatively between June 1993 and November 1997. Arthroscopy had been performed in all cases in order to classify the extent and location of cartilage damage. One hundred and nine patients (47%) were available for follow-up after a mean of 12.9 years. The main outcome parameters were the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score for clinical evaluation and a modified Kannus osteoarthritis score for radiographic assessment of the development of posttraumatic osteoarthritis.

RESULTS

Cartilage damage anywhere in the ankle joint was associated with a suboptimal clinical outcome (odds ratio, 5.0 [95% confidence interval = 1.3 to 20.1]; p = 0.02) and with a suboptimal radiographic outcome (odds ratio = 3.4 [95% confidence interval = 1.0 to 11.2]; p = 0.04). An association was also found between the development of clinical signs of osteoarthritis and a deep lesion (>50% of the cartilage thickness) on the anterior aspect of the talus (odds ratio = 12.3 [95% confidence interval = 1.4 to 108.0]; p = 0.02) and a deep lesion on the lateral aspect of the talus (odds ratio = 5.4 [95% confidence interval = 1.2 to 23.5]; p = 0.02). A deep lesion on the medial malleolus was associated with the development of clinical signs of osteoarthritis (odds ratio = 5.2 [95% confidence interval = 1.9 to 14.6]; p < 0.01) and radiographic signs of osteoarthritis (odds ratio = 2.9 [95% confidence interval = 1.1 to 7.9]; p = 0.03) of osteoarthritis. There was no significant correlation between cartilage lesions on the fibula and the long-term outcome.

CONCLUSIONS

Our findings show that initial cartilage damage seen arthroscopically following an ankle fracture is an independent predictor of the development of posttraumatic osteoarthritis. Specifically, lesions on the anterior and lateral aspects of the talus and on the medial malleolus correlate with an unfavorable clinical outcome.

Accuracy of corrective osteotomies in fibular malunion: a cadaver model

BACKGROUND

While incorrect length of a fibular fracture reduction can be measured by plain radiographs, accurate imaging of rotational deformities requires computed tomography (CT). Operative correction of fibular malrotation has not been accurately measured. The aim of this study was to evaluate the accuracy of operative correction of fibular malrotation.

MATERIALS AND METHODS

Six pairs of formalin-fixed, lower leg cadaver specimens had shortening with additional internal or external rotation induced by segmental fibular resection and plate fixation. The deformity was measured by CT. Two experienced surgeons performed standardized corrective operations on six specimens each. The postoperative results were measured by CT.

RESULTS

The mean overall accuracy for correction of malrotation was 1.58 degrees (SD = 0.8 degrees). There were no significant differences between the two surgeons performing the corrections.

CONCLUSION

The accuracy of operative correction of malrotation in this cadaver model is in accordance with the requirements reported in clinical studies.

CLINICAL RELEVANCE

Considering the error margin for CT analysis, correction within 5 to 10 degrees seems practical.

Distal fibula malunions

Anatomic reduction and fixation of unstable ankle fractures is necessary to prevent posttraumatic arthritis. Malunion of the distal fibula in unstable ankle fractures may lead to progressive talar instability. Ankle fracture malunions often present with concomitant syndesmotic widening, which can cause surgeons to overlook changes in fibula length and rotation. The decision to proceed with surgery should be made only after a careful diagnostic workup and detailed preoperative discussion with the patient. Considerations for surgical management include location and orientation of a corrective osteotomy, use of structural graft, widening of the syndesmosis, assessment of reduction, and the need for medial exposure. Good and excellent clinical results after fibular reconstruction have been reported in 67% to 92% of ankles. Proper patient selection is critical, because ankle malunions can be complicated, with coexisting fibular, syndesmotic, medial, and posterior malleolar malalignment, along with degenerative joint disease. Understanding the indications and surgical technique for revising fibular malunions may obviate a future salvage procedure.

Management of complications of open reduction and internal fixation of ankle fractures

The management of complications resulting from the open reduction and internal fixation of ankle fractures is discussed in detail. The initial radiographic findings of the most common postsurgical complications of ankle fracture reduction are briefly discussed, namely lateral, medial, and posterior malleolar malunion or nonunion, syndesmotic widening, degenerative changes, and septic arthritis with or without concomitant osteomyelitis. Emphasis is placed on the management of these complications, with a review of the treatment options proposed in the literature, a detailed discussion of the authors' recommendations, and an inclusion of different case presentations.

Surgical techniques for the reconstruction of malunited ankle fractures

Ankle fractures are so common and most heal well so there is a certain lack of attention for the potential for adverse consequences and the potential to salvage these complications. There is a clear association between ankle fracture malunion and a poor outcome, whilst reconstruction can often be accomplished it can be very difficult. The key lies in accurate assessment, careful preoperative planning and proficiency in specialised reconstructive techniques. In this article, we describe this process using clinical cases to illustrate the management of malunion.

A rational approach to ankle fractures

Ankle fractures involve a spectrum of injury patterns from simple to complex, such that these injuries are not always "just an ankle fracture." By combining the injury mechanism and the radiographic findings, the surgeon can apply the Lauge-Hansen classification in taking a rational approach to the management of these fractures. Syndesmotic instability and atypical patterns are becoming increasingly recognized, in part through the judicious use of CT scans. The goal of surgical stabilization includes atraumatic soft tissue management, rigid internal fixation, and early range of motion exercises in maximizing return of function.

Injuries to the distal tibiofibular syndesmosis: an evidence-based approach to acute and chronic lesions

Injuries to the distal tibiofibular syndesmosis are frequent in collision sports. Most of these injuries are not associated with latent or frank diastasis between the distal tibia and fibula and are treated as high ankle sprains, with an extended protocol of physical therapy. Relevant instability of the syndesmosis results from rupture of two or more ligaments leading to a diastasis of more than 2 mm and requiring surgical fixation. Most of these syndesmosis ruptures are associated with bony avulsions or malleolar fractures. Treatment consists of anatomic reduction of the fibula and fixation with one or two tibiofibular syndesmosis screws. Proper reduction and positioning of the screws are more predictive of a good clinical result than the material, size, and number of cortices purchased. Chronic injuries without instability are treated by arthroscopic or open debridement and arthrolysis. Chronic syndesmotic instability can be treated with a three-strand peroneus longus ligamentoplasty in the absence of symptomatic arthritis or bony defects.

Fibular lengthening for malunited ankle fractures

BACKGROUND

Malunited ankle fractures are uncommon. They produce symptoms of persistent pain, joint effusion, limitation of dorsiflexion and eventually lead to ankle arthritis. We feel that correction of the ankle alignment can improve the final outcome and present our results.

MATERIALS AND METHOD

From May 2004 to April 2006, seven patients with a malunited fibular fracture aged 25 to 62 years (male:female ratio, 5:2) were treated in our institute. All patients were referred for persistent pain. The delay between injury and the operative intervention was 3 to 16 months. All patients were assessed with a clinical examination, AOFAS ankle hindfoot score and plain radiographs. A transverse fibular osteotomy was made just above the ankle joint and below the tibiofibular syndesmosis. A tricortical iliac bone graft and a lateral fibular plate were applied.

RESULTS

Fibular length and restoration of the ankle mortise was successful in all the cases. All patients showed radiological evidence of bony union on followup. The average AOFAS score was 82 (pain: 31, function: 41, and alignment: 10). Patients were followed up for an average period of 11 (range, 6 to 24) months after the surgery.

CONCLUSION

We present our early experience with a simpler fibular osteotomy to correct the ankle joint alignment for malunited fibular fractures which was successful at short-term followup.

Valgus ankle deformity and arthritis

This article describes several conditions that may result in valgus ankle arthritis. The emphasis is on correction of pathology or deformity to prevent valgus arthritis from developing. The surgical techniques available for the treatment of this form of ankle arthritis, once it develops, are described also.

Fibular lengthening by Ilizarov method secondary to shortening by osteochondroma of distal tibia

Osteochondroma is the most common benign bone tumour. They most commonly affect the long tubular bones and almost half of osteochondromata are found around the knee. Osteochondroma arising from the distal metaphysis of the tibia typically result in a valgus deformity of the ankle joint secondary to relative shortening of the fibula. This case describes the use of Ilizarov technique for fibular lengthening following excision of a distal tibial osteochondroma. A 12-year-old girl presented with a 3-year history of a large swelling affecting the lateral aspect of the right distal tibia. Plain radiographs confirmed a large sessile osteochondroma arising from the postero-lateral aspect of the distal tibia with deformity of the fibula and 15 mm of fibular shortening. The patient underwent excision through a postero-lateral approach and subsequent fibular lengthening by Ilizarov technique. The patient made excellent recovery with removal of frame after 21 weeks and had made a full recovery with normal ankle function by 6 months. The Ilizarov method is a commonly accepted method of performing distraction osteogenesis for limb inequalities; however, this is mainly for the tibia, femur and humerus. We are unaware of any previous cases using the Ilizarov method for fibular lengthening. This case demonstrates the success of the Ilizarov method in restoring both fibular length and normal ankle anatomy.

Nonoperative treatment of bimalleolar equivalent ankle fractures: a retrospective review of 51 patients

The purpose of this retrospective study was to determine the outcome of bimalleolar equivalent ankle fractures in patients who were treated nonoperatively. The charts of 214 patients with isolated Weber B (supination-external rotation pattern) fibula fractures were reviewed. Fifty-one patients met the inclusion criteria and were administered the American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey by telephone or personal interview. The average medial clear space was 5.09 mm; the average American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey score was 84.22. A medial clear space of 4, 5, 6, and 7 mm resulted in American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey scores of 90.22, 89.4, 72.0 and 63.17, respectively. Further analysis showed significant differences in American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey scores between the 4 mm medial clear space group and the 6 mm and 7 mm medial clear space groups; the 5 mm medial clear space group and the 6 mm and 7 mm groups. Our results suggest that medial tenderness and ecchymosis alone are not sufficient to meet operative criteria, a higher medial clear space on stress gravity views correlates with a lower American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey score, and that there are significant differences in American Orthopaedic Foot and Ankle Society Ankle and Hindfoot Functional Survey scores between groups with medial clear space 4 to 7 mm. ACFAS Level of Clinical Evidence: 2b.