Biomechanics of Ankle Ligament Reconstruction: A Cadaveric Study to Compare Stability of Reconstruction Techniques Using 1 or 2 Fibular Tunnels.

BACKGROUND: Anatomic lateral ankle ligament reconstruction has been proposed for patients with chronic ankle instability. A reliable approach is a reconstruction technique using an allograft and 2 fibular tunnels. A recently introduced approach that entails 1-fibular tunnel reconstruction might reduce the risk of intraoperative complications and ultimately improve patient outcome. HYPOTHESIS: We hypothesized that both reconstruction techniques show similar ankle stability (joint laxity and stiffness) and are similar to the intact joint condition. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 10 Thiel-conserved cadaveric ankles were divided into 2 groups and tested in 3 stages-intact, transected, and reconstructed lateral ankle ligaments-using either the 1- or the 2-fibular tunnel technique. To quantify stability in each stage, anterior drawer and talar tilt tests were performed in 0°, 10°, and 20° of plantarflexion (anterior drawer test) or dorsiflexion (talar tilt test). Bone displacements were measured using motion capture, from which laxity and stiffness were calculated together with applied forces. Finally, reconstructed ligaments were tested to failure in neutral position with a maximal applicable torque in inversion. A mixed linear model was used to describe and compare the outcomes. RESULTS: When ankle stability of intact and reconstructed ligaments was compared, no significant difference was found between reconstruction techniques for any flexion angle. Also, no significant difference was found when the maximal applicable torque of the 1-tunnel technique (9.1 ± 4.4 N·m) was compared with the 2-tunnel technique (8.9 ± 4.8 N·m). CONCLUSION: Lateral ankle ligament reconstruction with an allograft using 1 fibular tunnel demonstrated similar biomechanical stability to the 2-tunnel approach. CLINICAL RELEVANCE: Demonstrating similar stability in a cadaveric study and given the potential to reduce intraoperative complications, the 1-fibular tunnel approach should be considered a viable option for the surgical therapy of chronic ankle instability. Clinical randomized prospective trials are needed to determine the clinical outcome of the 1-tunnel approach.

The influence of obesity and gender on outcome after reversed L-shaped osteotomy for hallux valgus.

BACKGROUND: Hallux valgus deformity (HV) affects around every fourth individual, and surgical treatment is performed in every thousandth person. There is an ongoing quest for the best surgical management and reduction of undesirable outcomes. The aim was to explore associations of obesity and gender with radiological and clinical outcome after reversed L-shaped osteotomy (ReveL) for HV. MATERIALS AND METHODS: This study was carried out in a retrospective cohort design at a single University Hospital in Switzerland between January 2004 and December 2013. It included adult patients treated with ReveL for HV. The primary exposure was body mass index (BMI) at the time of ReveL. The secondary exposure was gender. The primary outcome was radiological relapse of HV (HV angle [HVA] > 15 degrees [°]) at the last follow-up. Secondary outcomes were improvable patient satisfaction, complication, redo surgery, and optional hardware removal. Logistic regression analysis adjusted for confounders. RESULTS: The median weight, height, and BMI were 66.0 (interquartile range [IQR] 57.0-76.0) kilograms (kg), 1.65 (IQR 1.60-1.71) metres (m), and 24.0 (IQR 21.3-27.8) kg/m2. Logistic regression analysis did not show associations of relapse with BMI, independent of age, gender, additional technique, and preoperative HVA (adjusted odds ratio [ORadjusted] = 1.10 [95% (%) confidence interval (CI) = 0.70-1.45], p = 0.675). Relapse was 91% more likely in males (ORadjusted = 1.91 [95% CI = 1.19-3.06], p = 0.007). Improvable satisfaction was 79% more likely in males (ORadjusted = 1.79 [CI = 1.04-3.06], p = 0.035). Hardware removal was 47% less likely in males (ORadjusted = 0.53 [95% CI 0.30-0.94], p = 0.029). CONCLUSIONS: In this study, obesity was not associated with unsatisfactory outcomes after ReveL for HV. This challenges the previous recommendation that preoperative weight loss may be necessary for a successful surgical treatment outcome. Males may be informed about potentially higher associations with unfavourable outcomes. Due to the risk of selection bias and lack of causality, findings may need to be confirmed with clinical trials.

Radiological and Clinical Outcome After Reversed L-Shaped Osteotomy: A Large Retrospective Swiss Cohort Study.

The objective was to report radiological and clinical outcomes after reversed L-shaped osteotomy (ReveL) for hallux valgus (HV). A retrospective cohort study was performed between January 2004 and December 2013. The primary outcome was radiological recurrence of HV (HV angle [HVA] >15°). There were various exposure and secondary outcome variables. The results showed a median follow-up of 12.0 months (N = 827). Radiological recurrence, limited patient satisfaction, complication, revision surgery, and elective hardware removal were found in 25.0%, 15.3%, 4.6%, 2.5%, and 26.7%. Median pre- to postoperative changes were highest for HVA (delta = -16.7°). Recurrence was more likely in cases with preoperative HVA ≥40° (adjusted odds ratio [ORadjusted]) 3.63, p < .001). Revisions were more likely with concomitant diseases and bilateral surgery (ORadjusted 12.53, p = .010; ORadjusted 3.35, p = .030). Hardware removal was less likely in patients ≥50 years (ORadjusted 0.67, p = .014). In conclusion, ReveL was a good surgical option for HV because of the relatively low rates of unfavorable outcomes.

The influence of the number of screws and additional surgical procedures on outcome in hallux valgus treatment.

BACKGROUND: Surgical treatment of hallux valgus (HV) is one of the major flagships of orthopedic surgeons. Due to relatively unsatisfactory radiological and clinical outcomes, the search for the best surgical technique and causes for unsatisfactory outcomes continues. The objective was to investigate associations of the number of screws and additional surgical techniques for HV with radiological and clinical outcome after reversed L-shaped osteotomy (ReveL). METHODS: A retrospective cohort study of adults from a single University Hospital between 2004 and 2013 was performed. The primary exposure was the number of screws (one vs two) used for osseous fixation after ReveL. The secondary exposure was an additional surgical technique for HV (e.g., Akin osteotomy). The primary outcome was a radiological recurrence of HV (HV angle (HVA) > 15°) at last follow-up. The secondary outcomes were limited patient satisfaction, complication, revision surgery, and elective hardware removal. Odds ratio (OR) and 95% confidence interval (CI) were estimated by logistic regression adjusting for confounders. RESULTS: The recurrence was 45% less likely with the use of one screw, independent of age, sex, additional technique, and preoperative HVA (odds ratio (ORadjusted) = 0.55 [95% CI 0.30-0.98], p = 0.043). The recurrence was 162% more likely with an additional surgical technique for HV (ORadjusted = 2.62 [1.24-5.52], p = 0.011). CONCLUSION: In ReveL for HV, a single screw (instead of two screws) may be sufficient enough for a similar or even better outcome, which may also reduce costs. Additional surgical procedures for HV may be refrained from if possible. Due to limitations of a retrospective study, results may need validation with clinical trials.

The V sign in lateral talar process fractures: an experimental study using a foot and ankle model.

BACKGROUND: Lateral talar process fractures (LTPF) are often missed on conventional radiographs. A positive V sign is an interruption of the contour of the LTP. It has been suggested, but not proven to be pathognomonic for LTPF. The objective was to study whether the V sign is pathognomonic for LTPF and if it can be properly assessed in different ankle positions and varying fracture types. METHODS: An experimental study was conducted. Two investigators assessed lateral radiographs (n = 108) of a foot and ankle model. The exposure variables were different ankle positions and fracture types. The primary outcome was the correct detection of a V sign. The secondary outcomes were the detection of the V sign depending on ankle position and fracture type as well as the uncertainty. RESULTS: The interobserver agreement on the V sign and type of fracture were fair (κ = 0.35, 95% CI 0.18-0.53, p < 0.001 and κ = 0.37, 95% CI 0.26-0.48, p < 0.001). The mean sensitivity, specificity, PPV, NPV, and likelihood ratio for the detection of the V sign were 77% (95% CI 67-86%), 59% (95% CI 39-78%), 85% (95% CI 75-92%), 46% (95% CI 29-63%), and 2. The mean uncertainty in the V sign detection was 38%. The V sign identification stratified by ankle position and fracture type showed significant better results with increasing inversion (p = 0.035 and p = 0.011) and type B fractures (p = 0.001 and p = 0.013). CONCLUSIONS: The V sign may not be pathognomonic and is not recommended as the only modality for the detection of LTPF. It is better visualized with inversion, but does not depend on plantar flexion or internal rotation. It is also better seen in type B fractures. It is difficult to detect and investigator-dependent. It may be helpful in a clinical setting to point into a direction, but a CT scan may be used if in doubt about a LTPF.

Nano- and Microstructured model carrier surfaces to alter dry powder inhaler performance.

The present study investigates the effect of different carrier surface modifications on the aerosolisation performance and on the effective carrier payload of interactive blends for inhalation. Two different active pharmaceutical ingredients (APIs) were used: Formoterol fumarate dihydrate (FF) and budesonide (BUD). Blends were prepared with glass beads as model carriers which have been subjected to mechanical surface modifications in order to introduce surface roughness via treatment with hydrofluoric acid (HF) and/or milling with tungsten carbide (TC). As far as effective carrier payload, in this study expressed as true surface coverage (TSC), is concerned, surface modification had varying effects on blends containing BUD or FF. Aerodynamic characterisation in vitro showed a significant decrease in respirable fraction for glass beads treated with HF (40.2-50.1%), due to the presence of clefts and cavities, where drug particles were sheltered during inhalation. In contrast, grinding with TC leads to surface roughness on a nano scale, ultimately increasing aerodynamic performance up to 20.0-38.1%. These findings are true for both APIs, regardless of their chemical properties.

Outcome after protected full weightbearing treatment in an orthopedic device in diabetic neuropathic arthropathy (Charcot arthropathy): a comparison of unilaterally and bilaterally affected patients.

BACKGROUND: Charcot neuropathic arthropathy (CN) is a chronic, progressive, destructive, non-infectious process that most frequently affects the bone architecture of the foot in patients with sensory neuropathy. We evaluated the outcome of protected weightbearing treatment of CN in unilaterally and bilaterally affected patients and secondarily compared outcomes in protected versus unprotected weightbearing treatment. METHODS: Patient records and radiographs from 2002 to 2012 were retrospectively analyzed. Patients with Type 1 or Type 2 diabetes with peripheral neuropathy were included. Exclusion criteria included immunosuppressive or osteoactive medication and the presence of bone tumors. Ninety patients (101 ft), mean age 60.7 ± 10.6 years at first diagnosis of CN, were identified. Protected weightbearing treatment was achieved by total contact cast or custom-made orthosis. Ulcer, infection, CN recurrence, and amputation rates were recorded. Mean follow-up was 48 (range 1-208) months. RESULTS: Per the Eichenholtz classification, 9 ft were prodromal, 61 in stage 1 (development), 21 in stage 2 (coalescence) and 10 in stage 3 (reconstruction). Duration of protected weightbearing was 20 ± 21 weeks and 22 ± 29 weeks in patients with unilateral and bilateral CN, respectively. In bilaterally affected patients, new ulcers developed in 9/22 (41%) feet. In unilaterally affected patients, new ulcers developed in 5/66 (8%) protected weightbearing feet and 4/13 (31%) unprotected, full weightbearing feet (p = 0.036). The ulceration rate was significantly higher in bilaterally versus unilaterally affected patients with a protected weightbearing regimen (p = 0.004). Soft tissue infection occurred in 1/13 (8%) unprotected weightbearing feet and 1/66 (2%) protected weightbearing feet in unilaterally affected patients, and in 1/22 (4%) protected weightbearing feet of bilaterally affected patients. Recurrence and amputation rates were similar across treatment modalities. CONCLUSIONS: Bilateral CN results in significantly more ulcers than unilateral CN and leads to slightly higher soft tissue infections. Protected weightbearing in an orthopedic device can reduce the risk for complications in acute CN of the foot and ankle.

Correlation of Systemic Inflammatory Markers With Radiographic Stages of Charcot Osteoarthropathy.

BACKGROUND: Charcot osteoarthropathy (COA) is characterized by a progressive destruction of bone and joint associated with neuropathy and is most common in the foot and ankle. Clinical manifestation of COA is frequently indistinguishable from other causes of pain, swelling, and erythema of the affected extremity, in particular, infection. Diagnosis of COA can be challenging in particular in early stages where radiographic changes are sparse. The presence of elevated systemic inflammatory parameters in the context of suspected infection may delay early diagnosis and treatment of COA. The aim of this retrospective analysis was to assess whether elevated systemic inflammatory parameters may be present, in particular in early stages of COA and thus not be used as an exclusion criterion for the diagnosis of COA. METHODS: Forty-two patients (mean age 48.2 ± 9.4 years, 36 male, 6 female) with a diagnosis of unilateral COA were the subject of this retrospective study. The diagnosis of COA was confirmed by plain radiographs, magnetic resonance imaging and clinical course. Systemic inflammatory parameters were recorded at the time of referral. Acute stages (stages 0 and 1) were treated with a total contact cast (TCC) and protected weight bearing for a minimum of 6 weeks. For chronic stages (stages 2 and 3) custom-made shoes were prescribed. The feet were stratified into "acute" (Eichenholz stages 0 and 1) and "subacute/chronic" (Eichenholz stages 2 and 3) groups. RESULTS: Statistically significant differences were observed for all recorded systemic inflammatory parameters (C-reactive protein level, WBC count, erythrocyte sedimentation rate) between the acute and subacute/chronic groups. No statistical difference was observed considering the anatomic pattern of involvement. CONCLUSION: The present study demonstrated that elevated systemic inflammatory parameters may be present in COA and can further be used to distinguish between acute and subacute stages of COA, based on the Eichenholtz classification. Thus, we suggest that elevated inflammatory markers should not be considered an exclusion criterion for the diagnosis of COA. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Stainless steel wire versus FiberWire suture cerclage fixation to stabilize the humerus in total shoulder arthroplasty.

HYPOTHESIS: No. 5 FiberWire (Arthrex, Naples, FL, USA) cerclage (FWC) and 1.25-mm stainless steel wire cerclage (SSWC) are biomechanically similar in resistance to prosthetic subsidence in shoulder arthroplasty. METHODS: In this laboratory bench study, 3 different surgical knot configurations (4-throw knot, cow hitch, and simple hitch) using a No. 5 FWC were evaluated and compared with a 1.25-mm SSWC. First, distraction tests were performed using bovine femoral cortical half shells mounted on a testing jig. Cerclage tightening, load to a 3-mm gap opening, and load to total failure were measured. Second, uncemented humeral prosthetic stems were inserted into an experimentally split humeral medullary canal, secured by the cerclage. After 100 N of preloading, the prosthesis was advanced into the humerus at a speed of 0.2 mm/s, and resistance during subsidence up to a penetration depth of 10 mm, as well as gap opening, was measured. RESULTS: Tightening force showed higher values for SSWC (618 N) than FWC (131-137 N) (P < .001). Load to total failure was comparable among the 3 different FWC knots (2,642-2,804 N), which were significantly stronger than SSWC (1,775 N, P < .001). At 3 mm of distraction, SSWC (1,820 N), cow hitch (1,803 N), and single-throw hitch (1,709 N) performed significantly better than a 4-throw knot (1,289 N) (P < .01). Subsidence testing showed no difference in force restraint or gap opening between the best FWC and SSWC. CONCLUSIONS: FWCs appear, in vitro, equally suitable to steel wires to stabilize nondisplaced periprosthetic humeral fractures. To actively reduce a displaced fracture, steel wires may still be the first choice.