Todd A. Irwin

Current concepts review: insertional achilles tendinopathy.

Pathology of the Achilles tendon is a common source of posterior ankle and heel pain. A variety of terms have been used to describe similar but clinically distinct conditions involving this tendon including tendinosis, tendinitis, paratenonitis, and peritendinitis. The latter are misleading because their suffixes imply an inflammatory process. However, inflammatory cells are rarely present in biopsies from involved tendons.3 The most common histopathologic finding is a degenerative process characterized by disorganized collagen, abnormal neovascularization, necrosis and mucoid degeneration.34,58 Based on these findings, Maffulli and colleagues advocated for the term tendinopathy to describe the syndrome characterized by pain, swelling and impaired performance.39 While runners comprise the largest group of patients with chronic pain in the Achilles tendon, individuals of all activity levels and ages present with similar complaints. The location of the pain is an important discriminating factor, as insertional (tendon-bone junction) pain is often treated differently than noninsertional (2 to 6 cm proximal to the insertion) pain. This review will focus on insertional tendinopathy and will discuss related disorders including retrocalcaneal bursitis and Haglund’s deformity. Recently, much has been learned regarding the pathophysiology of Achilles tendinopathy and this knowledge has lead to the development of new treatment options. However, the evidence to support these innovative approaches has not been appraised. This current concepts review will present the etiology, pathophysiology, and evaluate the merits of

Posterior malleolus fracture.

&NA; Posterior malleolus fractures are a common component of ankle fractures. The morphology is variable; these fractures range from small posterolateral avulsion injuries to large displaced fracture fragments. The integrity of the posterior malleolus and its ligamentous attachment is important for tibiotalar load transfer, posterior talar stability, and rotatory ankle stability. Fixation of posterior malleolus fractures in the setting of rotational ankle injuries has certain benefits, such as restoring articular congruity and rotatory ankle stability, as well as preventing posterior talar translation, but current indications are unclear. Fragment size as a percentage of the anteroposterior dimension of the articular surface is often cited as an indication for fixation, although several factors may contribute to the decision, such as articular impaction, comminution, and syndesmotic stability. Outcome studies show that, in patients with ankle fractures, the presence of a posterior malleolus fracture negatively affects prognosis. Notable variability is evident in surgeon practice.

Variability in radiographic medial clear space measurement of the normal weight-bearing ankle.

Background: Medial clear space (MCS) width on mortise radiographs of the ankle is commonly used by clinicians for determining the competence of the deltoid ligament in the Weber B supination–external rotation ankle fracture. Significant variability exists in the current literature regarding methods of obtaining this measure and definition of a normal measure in comparison with a pathologic state. Methods: Seventy-three paired bilateral ankle mortise radiographs that were without ankle pathology were retrospectively reviewed. MCS width at two separate locations (oblique and perpendicular) and superior clear space (SCS) were measured on digital radiographs. A Students t test was used to compare mean values. Results: Mean values (± SD) were 3.2 (± 0.7) mm for MCS oblique, 2.6 (± 0.7) mm for MCS perpendicular, and 3.3 (± 0.6) mm for SCS. A significant difference (p < .001) existed for all three measures between males and females. MCS oblique was statistically different than MCS perpendicular (p < .001) for all patients and for males and females independently. The mean difference between paired bilateral radiographs was 0.3 (± 0.2) mm for MCS oblique, 0.6 (± 0.6) mm for MCS perpendicular, and 0.2 (± 0.2) mm for SCS. Conclusions: MCS width has variability based on the location chosen for measurement and gender. Contralateral radiographic comparison of MCS should be routinely used to identify pathologic widening versus normal anatomic variation. Clinical Relevance: Use of single threshold values for MCS width as an operative indicator may produce a false-positive diagnosis of deltoid incompetence in Weber B supination–external rotation ankle fractures and possibly lead to unnecessary surgery.

Effect of ankle arthritis on clinical outcome of lateral ankle ligament reconstruction in cavovarus feet.

Background: Patients with idiopathic cavovarus deformity and lateral ankle ligament instability often present with varying degrees of ankle arthritis. The purpose of this study was to determine whether the severity of degenerative change would impact the clinical outcome in patients treated operatively for both cavovarus deformity and lateral ankle ligament instability. Materials and Methods: Twenty-two patients were treated with lateral ankle ligament reconstruction and realignment foot osteotomy. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Karlsson and Peterson (KP) scoring scale, Visual Analog Scale (VAS) for pain, and level of satisfaction were obtained. Preoperative and postoperative ankle radiographs were reviewed and graded using the van Dijk score. Patients with Grade 0 and I arthritis preoperatively were grouped together as “no to minimal arthritis” (Group 1) and those with Grade II and III arthritis preoperatively as “moderate to severe arthritis” (Group 2). There were 14 ankles in Group 1 and eight ankles in Group 2. Mean followup was 60.4 months. Results: Mean AOFAS and KP scores were significantly improved in Group 1 compared to Group 2 at latest followup, while VAS pain scale trended lower in Group 1. There were 12 excellent/good results, one fair result, and one poor result in Group 1. Patients in Group 2 had three excellent/good results, two fair results, and three poor results. One of 14 patients in Group 1 had progression of arthritis, while five of eight patients in Group 2 either had progression of arthritis or required an ankle fusion. Conclusion: Patients treated with lateral ankle ligament reconstruction and cavovarus realignment osteotomy with no to minimal preoperative tibiotalar arthritis have higher clinical scores and increased satisfaction compared to patients with more advanced preoperative tibiotalar arthritis. A cautious and realistic approach should be followed when recommending surgical treatment for this patient population. Level of Evidence: IV, Retrospective Case Series

Relationship Among Radiographic Ankle Medial Clear Space, Sex, and Height

The ankle medial clear space (MCS) is frequently measured to evaluate ankle stability after an injury. However, controversy exists regarding a threshold size that distinguishes a normal MCS from an abnormal MCS. A retrospective radiographic review of mortise ankle radiographs in the uninjured ankle was performed, with the goal of defining the relationship among patient height, sex, and radiographic ankle MCS. Forty-nine patients with normal mortise radiographs and with information on patient height available in the electronic medical chart were identified for inclusion. For men, mean±standard deviation (in millimeters) was 3.3±0.8 for MCS perpendicular (MCSp), 3.8±0.7 for MCS oblique (MCSo), and 3.8±0.5 for superior clear space (SCS). For women, mean±standard deviation was 2.3±0.6 for MCSp, 2.9±0.5 for MCSo, and 3±0.4 for SCS. Univariate analysis showed that all 3 variables (MCSp, MCSo, and SCS) were statistically different when men were compared with women (P<.0001). Bivariate regression models showed statistically significant (P<.001) positive relationships between each of the measures of clear space and height. In multivariate analysis, female sex alone was associated with a decrease in clear space. When evaluating isolated lateral malleolus fractures, clinicians should consider the patients height and sex when measuring MCS and SCS to determine deltoid ligament competence. These data suggest that men and people of tall stature are at risk for a false-positive diagnosis of deltoid ligament rupture when previously published threshold MCS and SCS values, such as 4 mm or 5 mm, are used for diagnosis and operative indication.

Numerical evaluation of sequential bone drilling strategies based on thermal damage

Sequentially drilling multiple holes in bone is used clinically for surface preparation to aid in fusion of a joint, typically under non-irrigated conditions. Drilling induces a significant amount of heat and accumulates after multiple passes, which can result in thermal osteonecrosis and various complications. To understand the heat propagation over time, a 3D finite element model was developed to simulate sequential bone drilling. By incorporating proper material properties and a modified bone necrosis criteria, this model can visualize the propagation of damaged areas. For this study, comparisons between a 2.0 mm Kirschner wire and 2.0 mm twist drill were conducted with their heat sources determined using an inverse method and experimentally measured bone temperatures. Three clinically viable solutions to reduce thermally-induced bone damage were evaluated using finite element analysis, including tool selection, time interval between passes, and different drilling sequences. Results show that the ideal solution would be using twist drills rather than Kirschner wires if the situation allows. A shorter time interval between passes was also found to be beneficial as it reduces the total heat exposure time. Lastly, optimizing the drilling sequence reduced the thermal damage of bone, but the effect may be limited. This study demonstrates the feasibility of using the proposed model to study clinical issues and find potential solutions prior to clinical trials.

A Novel Algorithm for Isolated Weber B Ankle Fractures: A Retrospective Review of 51 Nonsurgically Treated Patients

Introduction: Stability of isolated Weber B ankle fractures can be difficult to determine. Using weight-bearing radiographs, a reliable method to determine the stability of isolated Weber B ankle fractures is described.Methods: A retrospective review of prospectively gathered data was performed. Weber B ankle fractures were defined as stable when having a medial clear space (MCS) of <7 mm on initial gravity stress radiographs and a normal mortise relationship on weight-bearing radiographs. Fifty-one patients meeting these criteria were treated nonsurgically with protected weight bearing and serial radiography for 1 year.Results: Average functional score results were: American Orthopaedic Foot and Ankle Society Hindfoot, 93.2; Foot and Ankle Ability Measure for Activities of Daily Living, 93.2; Olerud-Molander Ankle Score, 91.0; and visual analog scale pain score, 0.57. Despite a mean gravity stress MCS of 4.42 mm, no patient demonstrated subsequent MCS widening. Mean MCS on 1-year follow-up weight-bearing radiographs was 2.64 mm.Conclusion: Weight-bearing ankle radiographs are predictive of stability in isolated Weber B ankle fractures. Gravity stress radiographs using traditional measurement criteria may overestimate instability in these injuries. Nonsurgical treatment with protected weight bearing shows good early outcomes.Level of Evidence: IV

Comparison of cortical bone drilling induced heat production among common drilling tools.

Objectives: Significant data exist regarding heat production of twist drills; however, there are little data regarding cannulated drills or Kirschner (K) wires. This study compared the heat produced during bone drilling with twist drills, K wires, and a cannulated drill. It was hypothesized that drilling temperature would increase with tool sizes used in orthopaedic surgery; with twist drills producing the least amount of heat followed by cannulated drills and K wires. Methods: Twist drills (2.0, 2.5, and 3.5 mm), K wires (1.25, 1.6, and 2.0 mm), and a cannulated drill (2.7 mm) were driven into warmed human cadaveric tibia by a battery-powered hand drill. The drill was secured on a servo-controlled linear actuator to provide a constant advancing speed (1 mm/s) during drilling. Two thermocouples were embedded 2 mm from the surface at 0.5 and 1.5 mm from the drill hole margin. Eight tests were performed for each tool. Results: Twist drills exhibited a positive trend between size and heat production. The size effect was less significant with K wires. K wires resulted in significantly (P = 0.008 at 0.5 mm) higher peak temperatures than twist drills of the same size. A 2.7-mm cannulated drill produced more than double the temperature rise of a 2.5-mm twist drill. Conclusions: Twist drills produced the smallest temperature rise among all bit types. Thermal effects should not be a reason for choosing K-wire size. The cannulated drill showed significantly higher temperatures when compared with standard drills, reaching maximal temperatures comparable with K wires.

Spastic Foot and Ankle Deformities: Evaluation and Treatment

Spastic foot and ankle deformities can occur from various causes and have profound effects on individuals and society. Presentations can vary clinically and a thorough clinical evaluation, potentially with a dynamic electromyogram, is essential to selecting the most appropriate treatment. Nonoperative treatments, such as orthotics, casting, oral medications, and nerve blocks, can be effective but surgery is indicated if they are no longer effective. Of the various operative procedures to treat this condition, split anterior tibialis tendon transfer and tendo Achilles lengthening are the most commonly performed. Multiple surgical options have been shown to be effective.

Heat accumulation during sequential cortical bone drilling

Significant research exists regarding heat production during single‐hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two‐flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37°C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery‐driven hand drill guided by a servo‐controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5°C at the first hole to 20°C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from <0.5°C to nearly 13°C. The difference between drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist‐drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury.