Vinod K. Panchbhavi

Arthroscopically Detected Intra-Articular Lesions Associated with Acute Ankle Fractures

BACKGROUND Anatomic surgical realignment of ankle fractures may still be associated with poor clinical outcomes, possibly as a result of occult intra-articular injury. The aim of this study was to determine if the severity of an acute ankle fracture is correlated with an increased number of arthroscopically detected intra-articular chondral lesions. METHODS We conducted a retrospective review of the medical charts on 283 ankle fractures that had been treated with open reduction and internal fixation and for which ankle arthroscopy had been routinely performed. The severity of the ankle fractures was categorized, with use of the arthroscopic findings derived from the operative reports as well as the findings on preoperative radiographs, according to the Lauge-Hansen criteria. RESULTS Of the 283 patients, eighty-four (forty-four female and forty male) met our inclusion criteria. Chondral lesions were found in sixty-one patients (73%). Of seventeen fractures graded as pronation-external rotation or supination-external rotation type I according to the Lauge-Hansen classification, fifteen were associated with one or no chondral lesion and two, with two or more chondral lesions. Of ten fractures graded as pronation-external rotation or supination-external rotation type II, nine were associated with one or no chondral lesion and one, with two or more chondral lesions. Of fifty-six fractures graded as pronation-external rotation or supination-external rotation type IV, twenty-seven were associated with one or no chondral lesion and twenty-nine, with two or more chondral lesions. Type-IV pronation-external rotation and supination-external rotation ankle fractures were more likely to be associated with two or more chondral lesions than type-I fractures (odds ratio = 8.1, 95% confidence interval = 1.7 to 38.6; p = 0.0044) or type-II fractures (odds ratio = 9.7, 95% confidence interval = 1.1 to 81.5; p = 0.0172). CONCLUSIONS Chondral lesions are commonly found after an acute ankle fracture. This retrospective study demonstrated that the number of intra-articular chondral lesions associated with the more severe ankle fracture patterns (pronation-external rotation and supination-external rotation type-IV fractures) was greater than the number associated with the less severe ankle fracture patterns.

Screw Fixation Compared with Suture-Button Fixation of Isolated Lisfranc Ligament Injuries

BACKGROUND A cannulated screw is currently used to reduce and stabilize diastasis at the Lisfranc joint. The screw requires removal and may break in situ. A suture button does not have these disadvantages, but it is not known if it can provide stability similar to that provided by a cannulated screw or an intact Lisfranc ligament. The objective of the present study was to compare the stability provided by a suture button with that provided by a screw when used to stabilize the diastasis associated with Lisfranc ligament injury. METHODS Fourteen fresh-frozen, paired cadaveric feet were dissected to expose the dorsal region. A registration marker triad consisting of three screws was fixed to the first cuneiform and the second metatarsal. A digitizer was utilized to record the three-dimensional positions of the registration markers and their displacement in test conditions before and after cutting of the Lisfranc ligament and after stabilization of the joint with either a suture button or a cannulated screw. The first and second cuneiforms and their metatarsals were removed, and the ligament attachment sites were digitized. Displacement at the Lisfranc ligament and the three-dimensional positions of the bones were determined. RESULTS Loading with the Lisfranc ligament cut resulted in displacement that was significantly different from that after screw fixation (p = 0.0001), with a difference between means of 1.2 mm. Likewise, loading with the Lisfranc ligament cut resulted in a displacement that was significantly different from that after suture-button fixation (p = 0.0008), with a difference between means of 1.00 mm. No significant difference in displacement was found between specimens fixed with the suture button and those fixed with the screw. CONCLUSIONS Suture-button fixation can provide stability similar to that provided by screw fixation in cadaver specimens after isolated transection of the Lisfranc ligament.

Evaluation of results of endoscopic gastrocnemius recession

Background: Gastrocnemius recession is traditionally done as an open procedure. The aim of this retrospective study was to evaluate the safety and efficacy of gastrocnemius recession performed endoscopically. Methods: The procedure was done in 28 patients (17 men and 11 women), ranging in age from 16 to 72 years (average 47.57, SD 13.86) between January, 2001, and September, 2003. In three patients, the procedure was done bilaterally. Followup ranged from 4 to 36 months (average 22.00, SD 11.84). The procedure was done through a single medial or lateral portal using the 3M Agee Carpal Tunnel Release System (Micro Aire Surgical Instruments, Charlottesville, VA). Results: The initial incision for portal entry was at the wrong level in two of 31 procedures (6.5%), requiring a second incision. The recession could not be accomplished in one of 31 procedures (3.2%), so an open technique was used to complete transection of the gastrocnemius aponeurosis. One patient had a superficial wound infection (3.2%). There was no incidence of sural nerve or Achilles tendon damage. Analysis of results from a modified Olerud and Molander score using a paired student t-test revealed statistically significant improvement (p ≤ 0.05) in pain, stiffness, swelling, and overall average score after the procedure. Conclusion: The results of endoscopic gastrocnemius recession using the Agee Carpal Tunnel Release System have been encouraging, with limited morbidity. The technique proved both feasible and safe in this study.

Combination of hook plate and tibial pro-fibular screw fixation of osteoporotic fractures: a clinical evaluation of operative strategy.

Background: Internal fixation of osteoporotic ankle fractures is technically difficult and may fail because of unreliable purchase. This study was undertaken to determine if a combination of a hook plate and tibial pro-fibular screws can provide secure fixation until fracture union. Methods: Thirty-one patients between the ages of 55 and 90 years had open reduction and internal fixation of ankle fractures between April, 2001, and April, 2003. Sixteen patients with an average age of 71.4 years had ankle fracture fixation with a combination of hook plate and tibial pro-fibular screws for the distal fibular fracture, and 15 patients with an average age of 71.9 years had fixation of their ankle fractures with standard fixation technique using AO/ASIF principles but no tibial pro-fibular screws. All patients were followed with clinical and radiologic assessment at 2 weeks, 6 weeks, and 12 weeks postoperatively. At an average of 15.8 months after injury, patients also completed a mailed questionnaire with the Olerud-Molander ankle score and the AOFAS ankle-hindfoot score for preoperative and postoperative status. Results: All patients who had tibial pro-fibular screw fixation had fracture union without hardware failure or complications. In the standard fixation group two patients had wound breakdown and one had a valgus malunion with screw pull out. The AOFAS and Olerud-Molander scores for the standard open reduction and internal fixation were 57.3 and 82.8 before injury and 37 and 43.8 postoperatively, respectively. The AOFAS and Olerud-Molander scores for the hook plate and tibial pro-fibular fixation group were 55.9 and 81.3 before injury and 42.4 and 50.3 postoperatively, respectively. Conclusions: The combination of hook plate and tibial pro-fibular screws in osteoporotic ankle fractures in a series of patients has not been reported before. This novel technique provides stable fixation for osteoporotic ankle fractures in elderly patients until union is achieved with good clinical scores.

Comparison of Augmentation Methods for Internal Fixation of Osteoporotic Ankle Fractures

Background: Internal fixation of osteoporotic ankle fractures is associated with failure of fixation. This study compared different augmentation methods biomechanically. Materials and Methods: In nine paired fresh-frozen cadaver legs, an identical supination-external rotation type II ankle fracture was created. Fractures were stabilized using an eight-hole locking plate. In four pairs, two screws were inserted across the syndesmosis for purchase in the tibial metaphysis. One leg from each pair was randomly selected for injection of calcium sulphate-calcium phosphate graft into the screw holes. Each leg was mounted to an MTS machine in a custom loading frame. Axial cyclic loading to body weight was performed to measure displacement at the fracture site, followed by rotational loading to failure simulating a supination external rotation injury. Data were analyzed using a two-way paired t -test and ANOVA. Results: The specimens used had a mean bone mineral density of 0.49 ± 0.15 (SD) g/cm2, and a mean age of 83 ± 12 years. In the biomechanical tests, there were no significant differences between augmented and non-augmented locking plates without the tibia-pro-fibula screws in axial stiffness (p = 0.10), external rotation angle at failure (p = 0.42), failure torque (p = 0.57), energy absorbed before failure (p = 0.47), and motion at the fracture site with cyclic axial loading (p = 0.15). There were no significant differences between augmented and non-augmented locking plates with the tibia-pro-fibula screws in the external rotation angle at failure (p = 0.83), failure torque (p = 0.58), and failure energy (p = 0.4). However, the overall strength of the fixation tended to increase with tibia-pro-fibula screws and augmentation. Conclusion: Internal fixation of an osteoporotic lateral malleolar fracture using a locking plate and screws provided a construct comparable in strength to that augmented with calcium sulfate-calcium phosphate graft and/or tibia-pro-fibula screws. Clinical Relevance: Strategies to augment internal fixation of osteoporotic ankle fractures may minimize risk for failure of fixation and may enable early weight bearing mobilization and return to function in elderly patients.

The fate of syndesmotic screws.

Background: A standard protocol for the management of syndesmosis injuries has yet to be established. Debate persists regarding number of screws, screw diameter, number of cortices purchased, and the need for and timing of screw removal. The purpose of this study was to identify factors related to screw fixation that may lead to the ultimate failure of syndesmosis fixation defined as a loss of reduction of the syndesmosis, screw breakage, screw loosening, or widening of the medial clear space. Materials and Methods: A retrospective assessment of 137 consecutive patients who underwent open reduction and internal fixation of the distal tibiofibular joint at a single institution from 2004 to 2008 was performed. Clinical and radiographic data were recorded regarding problems with questionable clinical significance (number of syndesmotic screws, number of cortices, screw diameter, screw location, hardware failure) and loss of syndesmosis reduction. A series of Fishers exact tests were used to evaluate outcomes. A p value of 0.05 defined as significant. Results: The 3.5-mm diameter screws were statistically more likely to break than 4- or 4.5-mm screws, but there was no difference in frequency of loss of reduction of the syndesmosis as a function of screw diameter; however, a power study revealed an n value of 1656 would be required to show a significant difference. Conclusion: Screw diameter may have an effect on screw breakage but clinical significance of hardware failure itself is unknown including whether or not it results in a loss of reduction or failure of syndesmotic fixation. Level of Evidence: III, Retrospective Comparative Study

The use of calcium sulfate and calcium phosphate composite graft to augment screw purchase in osteoporotic ankles.

Background: Screws placed in the distal fibula may not have satisfactory purchase during internal fixation of an osteoporotic ankle fracture. Tibia-pro-fibula screws that extend from the fibula into the distal tibial metaphysis provide additional purchase. The purpose of this study was to investigate if purchase of these screws can be enhanced further by injecting calcium sulfate and calcium phosphate composite graft into the drill holes prior to insertion of the screws. Materials and Methods: Bone density was quantified using a DEXA scan in paired cadaver legs. One leg from each pair was randomly selected for injection of composite graft into the screw holes before insertion of the screws. Two screws were inserted through the fibula into the distal tibial metaphysis in each leg, at the level of the syndesmosis under fluoroscopy in a standardized fashion in an MTS machine. Results: After testing 4 pairs of cadaver legs, a statistically significant difference was noted in displacement (p = 0.018 distal, p = 0.0093 proximal), failure load, (p = 0.0185 distal, p = 0.0238 proximal), and failure energy (p = 0.0071 distal, p = 0.0115 proximal) between augmented and non-augmented screws, with the augmented screws being considerably stronger. Conclusion: Screws augmented with composite graft provide significantly greater purchase in an osteoporotic fibular fracture model. Clinical relevance: Composite graft augmented screws inserted into the distal tibia from the fibula may enhance the stability of internal fixation of an osteoporotic ankle fracture. This may enable earlier weightbearing and return to function which is important in elderly patients.

Synthetic Bone Grafting in Foot and Ankle Surgery

Synthetic bone graft materials have an established role as osteoconductive materials. The basic function is providing a matrix to support the attachment of bone-forming cells for subsequent bone formation, but these materials in various forms can be used for other functions. They can be used as a vehicle for local antibiotic delivery and in injectable form they can be used in a minimally invasive fashion to fill voids and strengthen purchase of screws in osteoporotic bones. They can provide prolonged structural support, which is important for early weight bearing in the lower extremity. These are some of the qualities that may not be obtained from autograft bone, the traditional gold standard for bone grafting. Therefore, these synthetic bone graft substitutes have earned a unique place in the armamentarium when issues such as bone defect, bone quality, and bone infection challenge bone healing and repair. This article reviews the basic science and use of such materials in foot and ankle surgery for conditions related to trauma, tumors, and infection.

A minimally disruptive model and three-dimensional evaluation of Lisfranc joint diastasis.

BACKGROUND There is no model that can reproduce the diastasis at the Lisfranc joint after isolated transection of the Lisfranc ligament. Prior models required extensive sectioning of ligaments in the midfoot and represent injuries that cause extensive tarsometatarsal fracture-dislocations. They do not represent a subset of injuries that cause subtle or limited disruption at the Lisfranc joint. The purpose of this study was to create a model with the minimum amount of ligamentous disruption and loading necessary to consistently observe diastasis at the Lisfranc joint. METHODS Fourteen fresh-frozen paired cadaver feet were dissected to expose the dorsum. Three screws were inserted into each first cuneiform and second metatarsal to create a pair of registration triads. A digitizer was utilized to record the three-dimensional positions of the screws and their displacement under loaded and unloaded conditions before and after the Lisfranc ligament was cut (intact and cut conditions). The first and second cuneiforms and their metatarsals were removed, and the attachment sites of the dorsal and the Lisfranc ligament were digitized. The three-dimensional positions of the bones and ligament displacement were determined. The significance of differences between conditions was tested with analysis of variance, and linear regression analysis was used to test the correlation between dorsal and plantar displacements. RESULTS There was a significant difference, of 1.3 mm, in the mean displacement between the cut loaded and intact loaded conditions (p < 0.0001). A modest correlation (r(2) = 0.60) was found between dorsal displacement and displacement at the site of the Lisfranc ligament, possibly attributable to rotations between the first cuneiform and second metatarsal. CONCLUSIONS Isolated sectioning of the Lisfranc ligament is sufficient to consistently create diastasis at the Lisfranc joint. Dorsal displacements between the first cuneiform and second metatarsal are a modest predictor of plantar displacements.

Comparison between manual and computer-assisted measurements of hallux valgus parameters

Background: The aim of this study was to determine if there are intraobserver and interobserver differences in reliability when measuring hallux valgus angles (HVA), 1–2 intermetatarsal angles (IMA), and distal metatarsal articular angles (DMAA) manually compared to computerassisted means. Our hypothesis was that the measurements taken by computer-assisted methods of these three forefoot angles would be superior in consistency and accuracy compared to manual measurements. Methods: Four examiners studied 20 weightbearing anteroposterior radiographs of patients with hallux valgus. Manual measurements were taken on photographic prints using a goniometer and a fine point pen. Computer-assisted measurements were taken on digitized images using computer software. Three sets of measurements by both of these methods were taken 1 week apart. Results: There was no statistically significant difference between digital and manual measurements for any of the three angles measured (p.05). However, the reliability of measurements within a range of 5 degrees for both methods was 70.6% for HVA, 84% for 1–2 IMA, and 59% for DMAA. Conclusion: There were no significant differences in interobserver and intraobserver reliability in measuring 1–2 IMA and HVA, regardless of the method of measurement; however, there was a significant difference in interobserver reliability when measuring the DMAA either on computer or manually (p = < .05).