Isolated Intermetatarsal Ligament Release as Primary Operative Management for Morton's Neuroma: Short-term Results.

BACKGROUND: Although the precise pathoetiology of Morton's neuroma remains unclear, chronic nerve entrapment from the overlying intermetatarsal ligament (IML) may play a role. Traditional operative management entails neuroma excision but risks unpredictable formation of stump neuroma. MATERIALS AND METHODS: Medical records were examined for adult patients who failed at least 3 months of conservative treatment for symptomatic and recalcitrant Morton's neuroma and who then underwent isolated IML decompression without neuroma resection. RESULTS: A total of 12 patients underwent isolated IML decompression for Morton's neuroma with an average follow-up of 13.5 months. Visual Analog Pain Scale averaged 6.4 ± 1.8 (4-9) preoperatively and decreased to an average of 2 ± 2.1 (0-7) at final follow-up (P = .002). All patients reported significant improvement. CONCLUSION: Isolated IML release of chronically symptomatic Morton's neuroma shows promising short-term results regarding pain relief, with no demonstrated risk of recurrent neuroma formation, permanent numbness, or postoperative symptom exacerbation. LEVEL OF EVIDENCE: Level IV: Case series.

Charcot Arthropathy of Foot and Ankle: Radiographic and Clinical Patterns with Related Outcomes.

PURPOSE: Our aim is to retrospectively review and evaluate the patterns of affection of Charcot arthropathy of foot and ankle. METHODS: Two hundred twenty-eight patients (235 feet) with post-acute Charcot were reviewed and classified anatomically through plain radiographs into type I and type II based on single or multiple regions affected, respectively. Type I included ankle, Lisfranc (tarsometatarsal), naviculocuneiform, forefoot, and hindfoot which includes one of the following: talonavicular joint, calcaneocuboid joint, or calcaneus. Type II included peritalar, perinavicular, mid-tarsal Charcot, or any other combination. Both types were further classified into four stages (A, stable with no deformity; B, stable with deformity; C, unstable; and D, deformity/instability with associated mechanical ulcers). RESULTS: The most common type was type IIC (27.2%) followed by type IID (18.3%), while types IA and IIA represented the least common types (3.4% and 3.8%, respectively). Types IA and IIA were managed conservatively. All patients in types IC, ID, IIB, IIC, and IID and the majority of type IB received fusion surgery to achieve stability and correction of deformity. Type II D had the highest complication rate (30%). Five patients ended up with amputation, and all were stage IID. CONCLUSION: Affection of single region has better prognosis than affection of two or more regions. Stage A has the best prognosis and can be managed conservatively provided good diabetes control. Surgery is indicated in all cases of types IC, ID, IIB, IIC, and IID to achieve stability and correction of deformity and prevent complications. Mechanical ulcer (stage D) carries the worst prognosis and highest complication rate.

Arthroscopic characterization of syndesmotic instability in the coronal plane: Exactly what measurement matters?

BACKGROUND: Although ankle arthroscopy is increasingly used to diagnose syndesmotic instability, precisely where in the incisura one should measure potential changes in tibiofibular space or how much tibiofibular space is indicative of instability, however, remains unclear. The purpose of this study was to determine where within the incisura one should assess coronal plane syndesmotic instability and what degree of tibiofibular space correlates with instability in purely ligamentous syndesmotic injuries under condition of lateral hook stress test (LHT) assessment. METHODS: Ankle arthroscopy was performed on 22 cadaveric specimens, first with intact ankle ligaments and then after sequential sectioning of the syndesmotic and deltoid ligaments. At each step, a 100N lateral hook test was applied through a lateral incision 5 cm proximal to the ankle joint and the coronal plane tibiofibular space in the stressed and unstressed states were measured at both anterior and posterior third of the distal tibiofibular joint, using calibrated probes ranging from 0.1 to 6.0 mm, in 0.1 mm of increments. The anterior and posterior points of measurements were defined as the junction between the anterior and middle third, and junction between posterior and middle third of the incisura, respectively. RESULTS: Anterior third tibiofibular space measurements did not correlate significantly with the degree of syndesmotic instability after transection of the ligaments, neither before nor after applying LHT at all the three groups of different sequences of ligament transection (P range 0.085-0.237). In contrast, posterior third tibiofibular space measurements correlated significantly with the degree of syndesmotic instability after transection of the ligaments, both with and without applying stress in all the groups of different ligament transection (P range <0.001-0.015). Stressed tibiofibular space measurements of the posterior third showed higher sensitivity and specificity when compared to the stressed anterior third measurements. Using 2.7 mm as a cut off for posterior third stressed measurements has both sensitivity and specificity about 70 %. CONCLUSION: Syndesmotic ligament injury results in coronal plane instability of the distal tibiofibular articulation that is readily identified arthroscopically with LHT when measured in the posterior third of the incisura. CLINICAL RELEVANCE: When applying LHT, tibiofibular space measurement for coronal plane instability along the anterior third of the incisura is less sensitive for identifying syndesmotic instability and may miss this diagnosis especially when subtle.

Screw versus suture button in treatment of syndesmosis instability: Comparison using weightbearing CT scan.

BACKGROUND: The superiority of screw or suture button fixation for syndesmotic instability remains debatable. Our aim is to compare radiographic outcomes of screw and suture button fixation of syndesmotic instability using weight bearing CT scan (WBCT). METHODS: Twenty patients with fixation of unilateral syndesmotic instability were recruited and divided among two groups (screw = 10, suture button = 10). All patients had WBCT of both ankles ≥12 months postoperatively. RESULTS: In suture button group, injured side measurements were significantly different from normal side for syndesmotic area (P = 0.003), fibular rotation (P = 0.004), anterior difference (P = 0.025) and direct anterior difference (P = 0.035). In screw group, syndesmotic area was the only significantly different measurement (P = 0.006). CONCLUSION: While both screw and suture button didn't completely restore the syndesmotic area as compared to the contralateral uninjured ankle, external malrotation of the fibula was uniquely associated with suture button fixation. LEVEL OF EVIDENCE: III Retrospective Cohort Study.

Arthroscopic coronal plane syndesmotic instability has been over-diagnosed.

PURPOSE: Ankle arthroscopy is widely used for diagnosis of syndesmotic instability, especially in subtle cases. To date, no published article has systematically reviewed the literature in aggregate to understand which instability values should be used intraoperatively. The primary aim was to systematically review the amount of tibiofibular displacement that correlates with syndesmotic instability after a high ankle sprain. A secondary aim is to assess the quality of such research. METHODS: Systematic searches of EMBASE (Ovid) and MEDLINE via PubMed, CINAHL, Web of Science, and Google Scholar were used. INCLUSION CRITERIA: studies that arthroscopically evaluated the fibular displacement at various stages of syndesmotic ligament injury. Two reviewers independently extracted data and assessed methodological quality using the Anatomical Quality Assessment (AQUA) Tool and methodological index for non-randomized studies (MINORS). RESULTS: Eight cadaveric studies and three clinical studies were included for review. All studies reported displacement in the coronal plane, four studies reported in the sagittal plane, and one reported findings in the rotational plane. Four cadaveric studies had a similar experimental set up and the weighted mean associated with instability in the coronal plane could be calculated and was 2.9 mm at the anterior portion of the distal tibiofibular joint and 3.4 mm at the posterior portion. Syndesmotic instability in the sagittal plane is less extensively studied, however available data from a cadaveric study suggests thresholds of 2.2 mm of posterior fibular translation when performing an anterior to posterior hook test and 2.6 mm of anterior fibular translation when performing a posterior to anterior hook test. CONCLUSIONS: The results have concluded that the commonly used 2.0 mm threshold value of distal tibiofibular diastasis may lead to overtreatment of syndesmotic instability, and that using threshold values of 2.9 mm measured at the anterior portion of the incisura and 3.4 mm at the posterior portion may represent better cut off values. Given the ready availability of 3 mm probes among standard arthroscopic instrumentation, at the very least surgeons should use 3 mm in lieu of 2 mm probes intraoperatively. LEVEL OF EVIDENCE: IV.

Tibial Stress Fracture Following Ankle Arthrodesis.

BACKGROUND: End-stage ankle arthritis is frequently treated with either tibiotalar or tibiotalocalcaneal (TTC) arthrodesis, but the inherent loss of accommodative motion increases mechanical load across the distal tibia. Rarely, patients can go on to develop a stress fracture of the distal tibia without any antecedent traumatic event. The purpose of this study was to determine the incidence of tibial stress fracture after ankle arthrodesis, highlight any related risk factors, and identify the effectiveness of treatment strategies and their healing potential. METHODS: A retrospective chart review was performed at 2 large academic medical centers to identify patients who had undergone ankle arthrodesis and subsequently developed a stress fracture of the tibia. Any patient with a tibial stress fracture before ankle arthrodesis, or with a nontibial stress fracture, was excluded from the study. RESULTS: A total of 15 out of 1046 ankle fusion patients (1.4%) developed a tibial stress fracture at a mean time of 42 ± 82 months (range, 3-300 months) following the index procedure. The index procedure for these 15 patients who went on to subsequently develop stress fractures included isolated ankle arthrodesis (n = 8), ankle arthrodesis after successful subtalar fusion (n = 2), primary TTC arthrodesis (n = 2), and ankle arthrodesis subsequent to successful subtalar fusion with resultant ankle nonunion requiring revision TTC nailing (n = 3). Four patients had undergone fibular osteotomy with subsequent onlay strut fusion, and 5 had undergone complete resection of the lateral malleolus. Stress fracture location was found to be at the level of the fibular osteotomy in 2 patients and at the proximal end of an existing or removed implant in 9. Fourteen of the 15 patients had a nondisplaced stress fracture and were initially treated with immobilization and activity modification. Of these, 3 failed to improve with nonoperative treatment and subsequently underwent operative fixation (intramedullary nail in 2; plate fixation in 1). Only 1 of the 15 patients presented with a displaced fracture and underwent immediate plate fixation. All patients reported pain improvement and were ultimately healed at final follow-up. CONCLUSION: In this case series review, we found a 1.4% incidence of tibial stress fracture after ankle arthrodesis, and both hardware transition points and a fibular resection or osteotomy appear to be risk factors. Operative intervention was required in approximately 25% of this population, but the majority of tibial stress fractures following ankle fusion were successfully treated nonoperatively, and ultimately all healed. LEVEL OF EVIDENCE: Level IV, retrospective case series.