Staged Extra-Articular Deformity Correction in the Setting of Total Knee Arthroplasty.

Background: Extra-articular lower-leg deformities mandate unique considerations when planning total knee arthroplasty (TKA). Poor limb alignment may increase perioperative complications and cause early implant failure. This study reports on the safety and efficacy of staged, extra-articular deformity correction about the knee in the setting of osteoarthritis and TKA. Methods: A retrospective review was conducted from December 2007 to December 2019 identifying 30 deformities in 27 patients (average age: 52.7 years; range 31-74) who underwent staged surgical correction of extra-articular deformity in preparation for TKA. Patient demographics, surgical details, clinical and radiographic measurements, severity of knee arthritis, and complications were collected. Results: There were 17 femur and 12 tibia deformities. There was an average improvement of 14.7° of deformity measured in the coronal plane and 12.7° of deformity in the sagittal plane in the femur and 13.5° in the coronal plane and 10.3° in the sagittal plane in the tibia. Leg length discrepancies improved by 26 mm on average (1-100 mm). After an average 3.1-year follow-up, 12 out of 27 patients proceeded with primary or revision TKA. There were no cases of blood transfusion, nerve palsy, or compartment syndrome, and all patients achieved bony union. Conclusions: Staged, extra-articular deformity correction is a safe and effective approach to improve limb alignment in the setting of knee osteoarthritis and TKA.

Triceps Surae Lengthening in Foot and Ankle Trauma: A Survey of OTA and AOFAS Members.

Background: The prevalence, indications, and preferred methods for gastrocnemius recession and tendo-Achilles lengthening-grouped as triceps surae lengthening (TSL) procedures-in foot and ankle trauma are supported by a scarcity of clinical evidence. We hypothesize that injury, practice environment, and training heritage are significantly associated with probability of performing adjunctive TSL in the operative management of foot and ankle trauma. Methods: A survey was distributed to members of the American Orthopaedic Foot & Ankle Society and the Orthopaedic Trauma Association. Participants rated how likely they would be to perform TSL at initial management, definitive fixation, and after weightbearing in the presence and absence of a positive Silfverskiöld test in 10 clinical scenarios of closed foot and ankle trauma. Results: A total of 258 surgeons with median 14 years' experience responded. Eighty-five percent reported foot and ankle fellowship training, 24% reported traumatology fellowship training, 13% both, and 4% no fellowship. Ninety-nine percent reported performing TSL with a median 25 TSL procedures per year, 72% open gastrocnemius recession, and 17% percutaneous tendo-Achilles lengthening). Across all scenarios, we observed low overall 8% probability with fair agreement (κ = 0.246) of performing TSL (range, 1% at initial management of an unstable Weber B bimalleolar ankle fracture with negative contralateral Silfverskiöld test to 29% at definitive fixation of tongue-type calcaneus fracture with positive contralateral Silfverskiöld test). Silfverskiöld testing significantly influenced TSL probability at all time points. University of Washington training (ß = 1.5, P = .007) but not trauma vs foot fellowship training, years in practice, academic practice, urban setting, or facility trauma designation were significantly associated with likelihood of performing TSL. Conclusion: Orthopaedic traumatology and foot and ankle surgeons report similar indications, methods, and low perceived propensity to use TSL in the management of foot and ankle trauma. We found that graduates of 1 fellowship training site were more likely to perform TSL in the setting of acute trauma potentially indicating the need for better scientific data to support this practice. Level of Evidence: Level V, therapeutic.

Mathematically Directed Single-Cut Osteotomy.

A mathematically directed osteotomy (MDO) is a surgical planning technique for correcting long bone deformities. Using a mathematically derived osteotomy plane, the single-cut correction simultaneously addresses angular deformity, axial malrotation, and minor shortening. This review describes an MDO's indications for use, defines its input and output variables, includes the required graphs for osteotomy planning, and provides intraoperative tips and tricks for successful execution. Finally, the authors present a digital MDO calculator to simplify the complex computations and allow for more precise planning.

Demographic data is more predictive of component size than digital radiographic templating in total knee arthroplasty.

BACKGROUND: Preoperative radiographic templating for total knee arthroplasty (TKA) has been shown to be inaccurate. Patient demographic data, such as gender, height, weight, age, and race, may be more predictive of implanted component size in TKA. MATERIALS AND METHODS: A multivariate linear regression model was designed to predict implanted femoral and tibial component size using demographic data along a consecutive series of 201 patients undergoing index TKA. Traditional, two-dimensional, radiographic templating was compared to demographic-based regression predictions on a prospective 181 consecutive patients undergoing index TKA in their ability to accurately predict intraoperative implanted sizes. Surgeons were blinded of any predictions. RESULTS: Patient gender, height, weight, age, and ethnicity/race were predictive of implanted TKA component size. The regression model more accurately predicted implanted component size compared to radiographically templated sizes for both the femoral (P = 0.04) and tibial (P < 0.01) components. The regression model exactly predicted femoral and tibial component sizes in 43.7 and 43.7% of cases, was within one size 90.1 and 95.6% of the time, and was within two sizes in every case. Radiographic templating exactly predicted 35.4 and 36.5% of cases, was within one size 86.2 and 85.1% of the time, and varied up to four sizes for both the femoral and tibial components. The regression model averaged within 0.66 and 0.61 sizes, versus 0.81 and 0.81 sizes for radiographic templating for femoral and tibial components. CONCLUSIONS: A demographic-based regression model was created based on patient-specific demographic data to predict femoral and tibial TKA component sizes. In a prospective patient series, the regression model more accurately and precisely predicted implanted component sizes compared to radiographic templating. LEVEL OF EVIDENCE: Prospective cohort, level II.

Prospective Comparison of Available Primary Total Knee Arthroplasty Sizing Equations.

BACKGROUND: Several studies have proposed regression equations that can increase the accuracy of predicting femur and tibia component sizes for total knee arthroplasty (TKA). This study compared available regression equations in their ability to prospectively predict component size in a unique patient series. METHODS: Demographic data and implanted femur and tibia TKA component sizes were collected on a consecutive 382 patients undergoing index TKA. Equations by Bhowmik-Stoker et al, Ren et al, Sershon et al, and Miller et al were identified that used age, race, ethnicity, gender, height, weight, or body mass index. Equation outputs were converted to implant-corrected sizes and compared to the implanted component. RESULTS: Femur and tibia sizes were accurately predicted within 1 size 88% and 92%, 84% and 86%, and 79% and 92% for Bhowmik-Stoker et al, Sershon et al, and Miller et al, respectively. Ren et al was within 1 tibia size 88% of the time. Adding one more common implant size improved this accuracy by an average of 9.1% and 6.6% for the femur and tibia, respectively. For femur components, Bhowmik-Stoker et al outperformed Sershon et al by 0.14 sizes (P < .001) and Miller et al by 0.21 sizes (P < .001) on average. For tibia components, Bhowmik-Stoker et al outperformed Sershon et al by 0.09 sizes (P = .028) and Ren et al by 0.11 sizes (P = .005) on average. CONCLUSION: Equations by Bhowmik-Stoker et al more accurately predicted implanted TKA size. In cases of greater uncertainty, the practicing surgeon may err on having more common TKA sizes available.

Ankle fusion following failed initial treatment of complex ankle fractures in neuropathic diabetics.

BACKGROUND: Unstable ankle fractures in diabetics with peripheral neuropathy have an increased risk of postoperative complications, often leading to amputation. Primary ankle arthrodesis has been suggested as an alternative when acceptable reduction and mechanical stabilization cannot be obtained. METHODS: Over a fourteen year period, thirteen diabetic patients with peripheral neuropathy underwent an attempt at primary ankle arthrodesis following the early post-fracture development of acute neuropathic (Charcot) deformity of the ankle after sustaining a low energy unstable ankle fracture. Eight patients with open wounds and osteomyelitis underwent single stage debridement of the osteomyelitis and primary ankle fusion with an ankle fusion construct circular external fixator. Five patients without evidence of infection underwent primary arthrodesis with a retrograde locked intramedullary nail used for fixation. A successful clinical outcome was achieved with either successful radiographic arthrodesis or stable pseudarthrosis, when community ambulation was achieved with commercially-available therapeutic footwear and a short ankle orthosis. RESULTS: Eight of the thirteen patients achieved a successful clinical outcome at a mean follow-up of 48 (range 12-136) months following the initial surgery. Three achieved clinical stability following a second surgery and one following a third. One patient with radiographic nonunion expired due to unrelated causes. One patient underwent transtibial amputation due to persistent infection. Of the five patients with failure of radiographic union, three successfully ambulated in the community with a short ankle orthosis. Postoperative complications included wound and pin-site infection, infected nonunion, chronic wounds, and tibial stress fracture. CONCLUSION: In spite of the high risk for complications and initial failure, primary ankle fusion is a reasonable option for diabetic neuropathic patients who develop acute neuropathic arthropathy following ankle fracture. LEVEL OF EVIDENCE: Level IV retrospective case series.

Biomechanical Properties of a Novel Mesh Suture in a Cadaveric Flexor Tendon Repair Model.

PURPOSE: Conventional suture repairs, when stressed, fail by suture rupture, knot slippage, or suture pull-through, when the suture cuts through the intervening tissue. The purpose of this study was to compare the biomechanical properties of flexor tendon repairs using a novel mesh suture with traditional suture repairs. METHODS: Sixty human cadaveric flexor digitorum profundus tendons were harvested and assigned to 1 of 3 suture repair groups: 3-0 and 4-0 braided poly-blend suture or 1-mm diameter mesh suture. All tendons were repaired using a 4-strand core cruciate suture configuration. Each tendon repair underwent linear loading or cyclic loading until failure. Outcome measures included yield strength, ultimate strength, the number of cycles and load required to achieve 1-mm and 2-mm gap formation, and failure. RESULTS: Mesh suture repairs had significantly higher yield and ultimate force values when compared with 3-0 and 4-0 braided poly-blend suture repairs under linear testing. The average force required to produce repair gaps was significantly higher in mesh suture repairs than in conventional suture. Mesh suture repairs endured a significantly greater number of cycles and force applied before failure compared with both 3-0 and 4-0 conventional suture. CONCLUSIONS: This ex vivo biomechanical study of flexor tendon repairs using a novel mesh suture reveals significant increases in average yield strength, ultimate strength, and average force required for gap formation and repair failure with mesh suture repairs compared with conventional sutures. CLINICAL RELEVANCE: Mesh suture-based flexor tendon repairs could lead to improved healing at earlier time points. The findings could allow for earlier mobilization, decreased adhesion formation, and lower rupture rates after flexor tendon repairs.

The Effect of Proton Pump Inhibitors on Bone Formation in a Rat Spinal Arthrodesis Model.

STUDY DESIGN: Rat posterolateral arthrodesis model. OBJECTIVE: Quantify the impact of administration of a proton pump inhibitor on spine fusion. SUMMARY OF BACKGROUND DATA: Proton pump inhibitors (PPIs) are widely used for gastrointestinal disorders and for ulcer prophylaxis in patients taking non-steroidal anti-inflammatory drugs. PPIs cause chronic acid suppression which has been found to result in decreased bone mineral density, increased fracture risk, and impaired fracture healing. Despite advances in surgical techniques, pseudarthrosis still occurs in up to 24% of patients requiring revision surgery following spinal fusion procedures. Thus, there are likely many unidentified risk factors. While PPIs have been hypothesized to impact fracture healing, no study has evaluated their effect on spine arthrodesis rates. METHODS: Thirty-eight female rats underwent posterolateral lumbar spinal fusion. Rats were divided into two groups: normal saline control and pantroprazole, which was administered by daily intraperitoneal injections. At 8 weeks postoperative spines were evaluated with manual palpation, microCT, histologic analysis, and biomechanical testing. RESULTS: Fusion rates of the control group and PPI group were not significantly different (100% vs. 94%). Average fusion scores were significantly lower in the pantoprazole group. New bone formation identified on microCT imaging of bilaterally fused specimens demonstrated a lower average volume of newly generated bone in the PPI group, but this difference was not significant. Biomechanical testing demonstrated no significant difference in strength or stiffness of the fusion mass between the groups. CONCLUSION: This study demonstrates that administration of PPIs does not inhibit fusion rates, bone formation, or affect biomechanical integrity of fusion. However, lower fusion scores in the PPI group suggest that a negative impact may still exist. Future studies will explore growth factor and protein expression in the fusion masses as well as utilize higher doses of PPI to fully discern their effect on spine fusion. LEVEL OF EVIDENCE: N/A.