Chamnanni Rungprai

The Effect of Suture-Button Fixation on Simulated Syndesmotic Malreduction: A Cadaveric Study

BACKGROUND The accuracy of reduction of distal tibiofibular syndesmosis disruptions has been associated with the clinical outcome. Suture-button fixation of the syndesmosis is a dynamic alternative mode of fixation. We hypothesized that with deliberate clamp-induced malreduction, suture-button fixation of the syndesmosis would allow a more anatomic post-fixation position compared with screw fixation. METHODS Forty-eight syndesmotic fixations were performed on twelve through-knee cadaveric specimens. The syndesmosis was destabilized and off-axis clamping was used to produce both anterior and posterior malreduction patterns. In twelve scenarios (six anterior and six posterior malreductions), syndesmotic screw fixation was used, followed by computed tomography. With tenacula holding the malreduction, the syndesmosis screws were exchanged for a suture-button construct and the specimens underwent a subsequent computed tomography scan. In the other twelve scenarios, the suture-button fixation was achieved first, followed by screw fixation. Standardized measurements of anterior-posterior and medial-lateral fibular displacement were performed by two observers blinded to the method of fixation. RESULTS With anterior off-axis clamping, the mean sagittal malreduction was 2.7 ± 2.0 mm with screw fixation and 1.0 ± 1.0 mm with suture-button fixation (p = 0.02). With posterior off-axis clamping, the sagittal malreduction was 7.2 ± 2.3 mm with screw fixation and 0.5 ± 1.4 mm with suture-button fixation (p < 0.01). No differences were observed between fixation types in the coronal plane (p = 0.20 for anterior malreductions and p = 0.06 for posterior malreductions). CONCLUSIONS With deliberate malreduction in a cadaver model, suture-button fixation of the syndesmosis results in less post-fixation displacement compared with screw fixation. The suture buttons ability to allow for natural correction of deliberate malreduction was greatest with posterior off-axis clamping. CLINICAL RELEVANCE Although the clinical relevance is unknown, dynamic syndesmotic fixation may mitigate clamp-induced malreduction.

Risks to the blood supply of the talus with four methods of total ankle arthroplasty: a cadaveric injection study.

BACKGROUND Despite the use of contemporary total ankle arthroplasty implant designs, clinical outcomes of total ankle arthroplasty continue to lag behind those of other joint replacement procedures. Disruption of the extraosseous talar blood supply at the time of ankle replacement may be a factor contributing to talar component subsidence-a common mechanism of early failure following ankle replacement. We evaluated the risk of injury to specific extraosseous arteries supplying the talus associated with specific total ankle arthroplasty implants. METHODS Sixteen fresh-frozen through-knee cadaveric specimens were injected with latex and barium sulfate distal to the popliteal trifurcation to visualize the arteries. Four specimens each were prepared for implantation of four contemporary total ankle arthroplasty systems: Scandinavian Total Ankle Replacement (STAR), INBONE II, Salto Talaris, and Trabecular Metal Total Ankle (TMTA). Postoperative computed tomography scans and 6% sodium hypochlorite chemical debridement were used to examine, measure, and document the proximity of the total ankle arthroplasty instrumentation to the extraosseous talar blood supply. RESULTS All four implant types subjected the extraosseous talar blood supply to the risk of injury. The INBONE subtalar drill hole directly transected the artery of the tarsal canal in three of four specimens. The lateral approach for the TMTA transected the first perforator of the peroneal artery in two of four specimens. The STAR caused medial injury to the deltoid branches in all four specimens, whereas the other three systems did not directly affect this supply (p < 0.005). The Salto Talaris and STAR implants caused injury to the artery of the tarsal canal in one of four specimens. CONCLUSIONS All four total ankle arthroplasty systems tested posed a risk of injury to the extraosseous talar blood supply, but the risks of injury to specific arteries were higher for specific implants.

Endoscopic Gastrocnemius Recession for the Treatment of Isolated Gastrocnemius Contracture A Prospective Study on 320 Consecutive Patients

Background: Endoscopic gastrocnemius recession has been proposed as a minimally invasive technique for the treatment of isolated gastrocnemius contracture. We report on the safety and efficacy of endoscopic gastrocnemius recession, as an isolated procedure or combined with other concomitant procedures in terms of improvement in ankle dorsiflexion, functional outcome, and postoperative morbidities. Methods: The data were prospectively collected in this case series. Endoscopic gastrocnemius recession was performed by a single surgeon in 320 consecutive patients (344 feet) who were diagnosed with isolated gastrocnemius contracture and failed nonoperative treatments between March 2009 and December 2012. There were 180 women and 140 men with mean age, 47.1 ± 15.7 years. The minimum follow-up was 1 year (mean, 18 months; range, 12 to 53 months). Pre- and postoperative ankle dorsiflexion, pain (Visual Analog Scale [VAS]), SF-36, and Foot Function Index (FFI) were obtained and compared using paired sample t test and Wilcoxon signed-rank test. Results: The mean ankle dorsiflexion significantly improved from −0.8 ± 5.4 degrees preoperatively to 11.0 ± 6.6 degrees at average of 13 months postoperatively (n = 294) (P < .001). Complete preoperative and 1-year postoperative pain (VAS) (n = 274) and functional outcome scores (n = 185) were collected when possible. The mean pain (VAS) decreased from 7/10 to 3/10 postoperatively (all P < .01). The mean SF-36 including physical component summary score (PCS) and mental component summary score (MCS) increased from 34 and 44 to 45 and 51, respectively (P < .01 for both PCS and MCS). The mean FFI improved from 63 to 42 for pain, 63 to 43 for disability, 68 to 44 for activity limitation, and 61 to 41 for total score postoperatively (all P < .01). Postoperative morbidity included weakness of ankle plantarflexion (N = 11/320; 3.1% respectively) and sural nerve dysesthesia (N = 10/320; 3.4%). Wound complications or Achilles tendon rupture did not occur. There was no difference in the average improvement in ankle dorsiflexion, outcome scores, and rate of complications between the isolated and combined procedures. Conclusion: Endoscopic gastrocnemius recession demonstrated promising results in the treatment of isolated gastrocnemius contracture. Ankle dorsiflexion was significantly improved with minimal morbidity. The procedure was found effective in improving functional outcomes and relieving pain as a sole operative treatment and as a part of combined procedures in our patients. Level of Evidence: Level IV, case series.

Incidence, Risk Factors, and Causes for Thirty-Day Unplanned Readmissions Following Primary Lower-Extremity Amputation in Patients with Diabetes

BACKGROUND The Centers for Medicare & Medicaid Services targeted thirty-day readmissions as a quality-of-care measure. Hospitals can be penalized on unplanned readmissions. Given the frequency of amputation in diabetic patients and our changing health-care system, the purpose of this study was to determine the incidence, risk factors, and causes for unplanned thirty-day readmissions following primary lower-extremity amputation in diabetic patients. METHODS Patients with a diagnosis of diabetes undergoing primary lower-extremity amputation between 2002 and 2013 were retrospectively identified in a single-center patient database. Chart review determined patient factors including comorbidities, hemoglobin A1c level, amputation level, and demographic characteristics. Patients were divided into groups with and without unplanned readmission within thirty days postoperatively. Univariate and multivariate logistic regression analyses were used to compare cohorts and to identify variables associated with readmission. RESULTS Overall, forty-six (10.5%) of 439 diabetic patients undergoing primary lower-extremity amputation had an unplanned thirty-day readmission. The top reason for readmission was a major surgical event requiring reoperation (37.0%), followed by medical events (28.3%) and minor surgical events (28.3%). In the univariate analysis, discharge on antibiotics (p = 0.002), smoking (p = 0.003), chronic kidney disease (p = 0.002), peripheral vascular disease (p = 0.002), and higher Charlson Comorbidity Index (p = 0.001) were each associated with readmission. In the multivariate analysis, diagnosis of gangrene (odds ratio [OR], 2.95 [95% confidence interval (95% CI), 1.37 to 6.35]), discharge on antibiotics (OR, 4.48 [95% CI, 1.71 to 11.74]), smoking (OR, 3.22 [95% CI, 1.40 to 7.36]), chronic kidney disease (OR, 2.82 [95% CI, 1.30 to 6.15]), and peripheral vascular disease (OR, 2.47 [95% CI, 1.08 to 5.67]) were independently associated with readmission. CONCLUSIONS Thirty-day readmission rates following primary lower-extremity amputation in patients with diabetes were high at >10%. Both medical and surgical complications, many of which were unavoidable, contributed to readmission. Quality-reporting metrics should include these risk factors to avoid undeservedly penalizing surgeons and hospitals caring for this patient population. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Validation and Reproducibility of a Biplanar Imaging System Versus Conventional Radiography of Foot and Ankle Radiographic Parameters

Background: Diagnosis of foot deformities is frequently supported by objective measures of bony alignment made on AP and lateral weight-bearing radiographs. The EOS biplanar imaging system has the capability of simultaneously capturing orthogonal AP and lateral images of the foot during weight-bearing with reduced radiation exposure. The purpose of this study was to evaluate the validity and reproducibility of common foot and ankle radiographic measurements made on images acquired with the EOS biplanar imaging system. Methods: Fifty consecutive patients indicated for foot and ankle realignment surgeries were enrolled. Radiographic studies included conventional AP and lateral ankle weight-bearing radiographs and long-leg AP and lateral weight-bearing images acquired using the EOS system with both a staggered feet and a nonstaggered feet position. Sixteen radiographic parameters of foot, ankle, and lower limb alignment were measured by 2 blinded observers, with 1 observer repeating all measurements 6 weeks later. Inter- and intraobserver reliability was assessed using intraclass correlation coefficients. Between-group comparison was assessed using Pearson correlation coefficients, ANOVA, and paired t-tests. Results: There was no statistically significant difference in any commonly used foot and ankle radiographic parameters measured on conventional radiographs or EOS images acquired with staggered and nonstaggered feet (ANOVA P = .792 to .997 and paired t tests P = .067 to .977). However, the staggered foot position resulted in significantly different limb length measurements in the rear leg (P = .000 to .049). Intra- and interrater reliabilities of limb alignment measurements from EOS system images were excellent in both foot positions (ICC = .938 to 1.000). Conclusion: Images acquired using EOS biplanar imaging system allowed for valid and reliable measurement of commonly used foot and ankle radiographic parameters; however, the staggered foot position required for simultaneous imaging of both feet in the lateral view affected limb length measurements in the rear leg. Level of Evidence: Level II, prospective comparative study.

Outcomes and Complications After Open Versus Posterior Arthroscopic Subtalar Arthrodesis in 121 Patients.

BACKGROUND Subtalar arthrodesis is a standard treatment for subtalar arthritis. Both open and arthroscopic techniques have been described and are commonly used. The cases of a consecutive series of 121 patients treated with either open or posterior arthroscopic techniques are presented with functional outcomes and complications. MATERIALS A retrospective chart review with prospectively collected data was performed for 121 consecutive patients (129 feet) who underwent subtalar arthrodesis with open (60 feet in 57 patients) or arthroscopic (69 feet in 64 patients) techniques between 2001 and 2014. The technique was selected on the basis of the deformity and surgeon preference. The primary outcomes were the visual analog scale (VAS) for pain, Short Form (SF)-36, Foot Function Index (FFI), and Angus and Cowell rating scores. Secondary outcomes included hindfoot alignment, operative time, length of hospital stay, fusion rate, time to return to work, ability to perform sports and activities of daily living, and complications. RESULTS Both groups demonstrated significant improvement in VAS, SF-36, FFI, and Angus and Cowell rating scale scores. The mean operative time, VAS score, Angus and Cowell rating score, and coronal plane hindfoot alignment were similar between the groups. There were no significant differences within the groups with respect to union rate and time to union among the various sizes of screws and types of bone graft. Sural nerve complications and a painful surgical scar were more frequent in the open group, whereas hardware-related symptoms were more frequent in the arthroscopically treated group. CONCLUSIONS Subtalar arthrodesis performed with open and arthroscopically assisted techniques demonstrated significant improvement in terms of pain and function as measured with the VAS, FFI, and SF-36. While the time to union and to return to work, activities of daily living, and sports activities were significantly shorter for the arthroscopic arthrodesis group, the union rates and complications overall were not significantly different. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Cortical Bone Thickness of the Distal Part of the Tibia Predicts Bone Mineral Density

BACKGROUND Poor bone density may affect surgical planning, treatment outcome, and postoperative protocols. Many patients with foot and ankle problems have not undergone a dual x-ray absorptiometry (DXA) scan, which is currently the gold standard for determining bone density. The purpose of this study was to determine if the cortical bone thickness (CBT) of the distal part of the tibia measured on radiographs correlated with bone mineral density. METHODS After exclusion criteria were applied, 167 consecutive adult patients (mean age and standard deviation [SD], 62 ± 11.62 years) who had had standardized ankle radiographs and a DXA scan within 6 months of each other were included in this retrospective study. The CBT was measured with both the gauge and the average method on standardized anteroposterior, lateral, and hindfoot alignment radiographs. The relationship between CBT in the distal part of the tibia and DXA findings in the hip, proximal part of the femur, and lumbar spine was assessed with Pearson correlations. The interrater and intrarater reliability of CBT measurements was assessed with intraclass correlation coefficients. Subgroup analysis was performed to determine the ability of CBT thresholds to predict osteoporosis. RESULTS Average CBT measurements on the anteroposterior, lateral, and hindfoot alignment views strongly correlated with DXA findings in the proximal part of the femur (r = 0.70, 0.64, and 0.55, respectively; p < 0.0001), the hip (r = 0.74, 0.67, and 0.53; p < 0.0001), and the lumbar spine (r = 0.61, 0.60, and 0.47; p < 0.0001). The interrater and intrarater reliability of the CBT measurements was excellent. Use of a 3.5-mm average CBT of the distal part of the tibia on the anteroposterior view as the threshold value for predicting osteoporosis (T score less than -2.5) had a sensitivity of 100%, a specificity of 25%, an accuracy of 33%, a positive predictive value of 19%, and a negative predictive value of 100%. CONCLUSIONS Measurement of the average CBT of the distal part of the tibia is a quick and reliable method for obtaining information on bone quality. CBT measured on standard ankle radiographs correlated strongly with DXA results and may prove to be a useful screening tool for osteoporosis. LEVEL OF EVIDENCE Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Simple Neurectomy Versus Neurectomy With Intramuscular Implantation for Interdigital Neuroma: A Comparative Study.

Background: Simple neurectomy is a standard treatment of interdigital nerve neuroma after failure of conservative treatment. Recently, neurectomy with intramuscular implantation of the proximal nerve stump has been proposed as a safe and effective alternative method providing significant pain improvement. However, there remains little evidence supporting one technique over the other. The purpose of this study was to compare functional outcomes and complications of simple neurectomy versus neurectomy with intramuscular implantation. Methods: Retrospective chart review along with prospectively collected data of 99 consecutive patients (105 feet with 118 neuromas) who were diagnosed with interdigital neuroma of the foot and underwent simple neurectomy (66 patients / 72 feet / 78 neuromas) and neurectomy with intramuscular implantation of proximal nerve stump into intrinsic muscle of foot (33 patients / 33 feet / 40 neuromas) between 2000 and 2013. The minimum follow-up to be included in the study was 6 months for both techniques (mean = 44.6 months, range = 6 to 150 months for simple neurectomy; and mean = 19.3 months, range = 6 to 66 months for neurectomy with intramuscular implantation of proximal nerve stump into the intrinsic muscle). The primary outcomes were Foot Function Index (FFI); pain, disability, activity limitation, and total score, Short Form-36 (SF-36: physical and mental component scores); and visual analog scale (VAS). Secondary outcomes included operative time and complications. Pre- and postoperative SF-36, and FFI, and pain (VAS) scores were obtained and compared using a paired t test. An independent t test was used to assess the functional outcomes and operative time between the 2 groups, and a chi-square test was used to compare the complications between the 2 techniques. Results: Both groups demonstrated significant improvement of postoperative functional outcomes (FFI, SF-36, and VAS; P < .001, all) compared to the preoperative period. Neurectomy with intramuscular implantation demonstrated significant improvement of pain compared to simple neurectomy as measured with VAS (P = .002); however, the operative time was significantly longer than the simple neurectomy technique (P = .001). The rest of the functional outcomes measured were comparable between the 2 techniques. Complications in both simple neurectomy and implantation techniques were persistent pain (11.5% vs 2.5%, P = .07), revision rate (5.1% vs 0.0%, P = .08), and painful scar (5.1% vs 5.0%, P = .83), respectively, but it did not reach statistical significance (P > .05, all). Conclusion: Both simple neurectomy and neurectomy with intramuscular implantation demonstrated significant improvement in terms of functional outcomes as measured with the FFI, SF-36, and VAS in patients with interdigital neuroma. Although requiring a longer operative time, neurectomy with intramuscular implantation technique might offer superior pain relief with comparable complications to the simple neurectomy technique. Level of Evidence: Level III, retrospective comparative study.

Disorders of the Flexor Hallucis Longus and Os Trigonum

Os trigonum syndrome with disease of the flexor hallucis longus tendon, so-called stenosing flexor tenosynovitis, is a common cause of posterior ankle impingement. Conservative treatment is the recommended first line of treatment, with secondary treatment options of either open or arthroscopic os trigonum excision with flexor hallucis longus retinaculum release. The arthroscopic approaches have gained popularity in the past decade because of less scarring, less postoperative pain, minimal overall morbidity, and earlier return to activities. However, comprehensive understanding of the anatomy of the posterior ankle is crucial to warrant successful outcomes and minimizing complications.

Bilateral anterior tarsal tunnel syndrome variant secondary to extensor hallucis brevis muscle hypertrophy in a ballet dancer: A case report

We present a case of bilateral anterior tarsal tunnel syndrome secondary EHB hypertrophy in a dancer, with successful treatment with bilateral EHB muscle excisions for decompression. The bilateral presentation of this case with the treatment of EHB muscle excision is the first of its type reported in the literature.