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.

Management of Segmental Tibial Bone Defects With the Magnetic Motorized Intramedullary Transport Nail: A Case Series

SUMMARY

Critical-sized bone defects in the tibia can arise as sequelae of trauma, infection, tumor, or the treatment of congenital limb deficiencies. Treatment of these defects often requires bone transport, which has traditionally been accomplished using circular external fixators. The development of a bone transport nail facilitated tibia reconstruction through distraction osteogenesis using an all-internal device, thus avoiding the complications associated with chronic external fixation. Given the rarity of these cases, few studies have been published on the reconstruction outcomes using this implant. We sought to investigate the bone healing indices (including regenerate consolidation and time to docking site union) associated with the use of a magnetically controlled all-internal bone transport nail for the reconstruction of 4 patients treated for posttraumatic tibial bone loss. Perioperative and device-related complications are also reported.

Avoiding Compartment Syndrome, Vascular Injury, and Neurologic Deficit in Tibial Osteotomy: An Observational Study of 108 Limbs

INTRODUCTION

Tibial deformities are common, but substantial concern may be associated with corrective osteotomy regarding major complications reported in classic literature. Such studies chiefly focused on high tibial osteotomy, with relatively little investigation of other areas and types of deformity. The primary aim of this study was to identify the rate of compartment syndrome, vascular injury, nerve injury, and other major complications after elective tibial osteotomy.

METHODS

One hundred eight tibia osteotomies performed during 2019 to 2021 were evaluated, representing all tibia osteotomies except situations of existing infection. A retrospective chart review was performed to identify patient demographics, surgical indications, anatomic location of osteotomy, fixation used, and complications prompting additional surgery.

RESULTS

The most common osteotomy locations were high tibial osteotomy (35/108 = 32%, 32/35 = 91% medial opening, and 3/35 = 9% medial closing), proximal metaphysis (30/108 = 28%), and diaphysis (32/108 = 30%). The most common fixation was plate and screw (38/108 = 35%) or dynamic frame (36/108 = 33%). Tranexamic acid was administered to 107/108 = 99% of patients and aspirin chemoprophylaxis was used for 83/108 = 86%. A total of 33/34= 97% of anterior compartment prophylactic fasciotomies were performed for diaphyseal or proximal metaphysis osteotomies. No events of compartment syndrome, vascular injury, nerve injury, or pulmonary embolism occurred. One patient required débridement to address infection. Additional surgery for delayed/nonunion occurred for nine segments (8%). Additional surgery for other reasons were performed for 10 segments (9%), none resulting in reduced limb function.

CONCLUSION

Tibial osteotomy can be safely performed for a variety of indications in a diverse range of patients, without a notable risk of the most feared complications of compartment syndrome, vascular injury, and neurologic deficit. Prophylactic fasciotomy and reducing postoperative bleeding using tranexamic acid, along with location-specific safe surgical techniques, may help prevent major complications and thereby facilitate optimized deformity care.

Signficant Femoral Version Abnormalities and Patient-Reported Quality of Life

INTRODUCTION

The purpose of this study was to determine how the Limb Deformity-Modified Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire scores differ between patients with femoral version abnormalities and healthy control subjects.

METHODS

A retrospective database review identified patients with femoral version abnormalities between December 2018 and September 2022. A total of 21 adult patients scheduled for femoral derotational osteotomy and 33 control subjects were included. All individuals completed the LD-SRS and PROMIS questionnaires.

RESULTS

Patients with femoral version abnormalities reported significantly worse scores than control subjects on all LD-SRS and PROMIS domains: LD-SRS (Total [3.46 ± 0.66 vs. 4.58 ± 0.37, P < 0.001]; Function/Activity [3.48 ± 0.83 vs. 4.44 ± 0.4, P < 0.001]; Mental Health [3.41 ± 0.96 vs. 4.3 ± 0.73, P < 0.001]; Pain [3.55 ± 0.9 vs. 4.81 ± 0.31, P < 0.001]; and Self-Image/Appearance [3.37 ± 0.79 vs. 4.75 ± 0.43, P < 0.001]) and PROMIS (Function [41.6 ± 7.58 vs. 60.0 ± 7.28, P < 0.001]; Pain Intensity [45.85 ± 8.04 vs. 33.7 ± 4.89, P < 0.001]; Pain Interference [56.78 ± 9.63 vs. 42.8 ± 6.6, P < 0.001]; Global Mental Health [47.97 ± 9.68 vs. 55.3 ± 7.81, P = 0.004]; and Global Physical Health [45.23 ± 7.49 vs. 58.2 ± 7.07, P < 0.001]).

DISCUSSION

Patients with femoral version abnormalities reported markedly worse quality of life as measured on the LD-SRS and PROMIS scores compared with healthy control subjects. The combination of these two surveys effectively captures the multifaceted quality-of-life-deficit individuals with excessive femoral version may experience.

Modern Internet Search Analytics and Osseointegration: What are Patients Asking and Reading Online?

Background

Osseointegration (OI) limb has been performed for over 30 years and is an example of an advance in technology and surgical technique which has led to improvements in patient mobility and quality of life. An increasing number of patients seek information about osseointegration. The aim of this study was to categorise the most frequently asked questions by patients using the Google search engine and the most frequently accessed websites with the highest return on answers. The secondary aims of this study were to assess the quality of the information provided on those websites and to stratify, by category, which websites provide the best quality information.

Materials and methods

Ten permutations and conjugations of the word 'osseointegration' were entered into Google. The first fifty 'People also ask' and associated websites by Google's machine learning and natural language processing engine were collected for each search term. The Rothwell classification system of questions by topic (Fact, Value, Policy) and websites by category was used (Commercial, Academic, Medical Practice, Single Surgeon Personal, Government, Social Media). Website quality was assessed using the Journal of the American Medical Association (JAMA) benchmark criteria (Likert-style rating 0-4). Pearson's Chi-squared and Student's t-tests were performed for statistical analysis as appropriate (significance, p < 0.05).

Results

The 10 search terms generated 454 questions and referenced 408 websites. Of the 454 questions generated, the most common question categories were fact (70.8%), value (19.2%), and policy (10%). The most common website type was social media (37.4%). The most common question types were technical details (30.4%), specific activity (20.6%), and cost (14.1%). Only 1.6% of questions related to risks and complications. Generally, website quality was poor with 64.1% having a JAMA score of 0 or 1. Websites that were categorised as 'Government' had the highest overall JAMA scores: 71.4% had a score of 4.

Conclusion

Based on Google search engine's results, the most commonly asked questions about osteointegration related to technical details, specific activities and cost; only 1.6% related to risks and complications. Interestingly, social media websites represented the highest volume of search result referrals. Overall, the quality of websites was poor with the most factual information coming from governmental websites.

How to cite this article

Murphy EP, Sheridan GA, Page BJ, et al. Modern Internet Search Analytics and Osseointegration: What Are Patients Asking and Reading Online? Strategies Trauma Limb Reconstr 2023;18(3):163-168.

The Management of Tibial Bone Defects: A Multicenter Experience of Hexapod and Ilizarov Frames

INTRODUCTION

Bone defects may be managed with bone transport or acute shortening and lengthening using circular external fixation devices. We performed a multicenter retrospective cohort study to compare the outcomes between the Ilizarov frames and hexapod frames for the management of bone defects.

METHODS

Patients treated for bone defects using either Ilizarov or hexapod frames were included for analysis in two specialist institutions. Primary outcomes were time to consolidation, bone healing index (BHI), and external fixator index (EFI). Radiographic parameters included the medial proximal tibial angle, lateral distal tibial angle, posterior proximal tibial angle, and anterior distal tibial angle.

RESULTS

There were 137 hexapods and 90 Ilizarov frames in total. The mean time to follow-up was 3.7 years in the hexapod group and 4.0 years in the Ilizarov group. Hexapods had a significantly lower time to consolidation (253 days versus 449 days) (P < 0.0001) and BHI (59.1 days/cm versus 87.5 days/cm) (P < 0.0001). Hexapods had a significantly better EFI (72.3 days/cm versus 96.1 days/cm) (P = 0.0009).

CONCLUSION

Hexapods may confer a significant advantage over Ilizarov frames in the management of bone defects. Time to consolidation, radiographic parameters, BHI, and EFI are all superior in hexapods.

Comparative fixation devices for preventing migration of the proximal tibiofibular joint during tibial lengthening: a tether versus screw fixation

BACKGROUND

When lengthening the tibia segment using motorized internal lengthening nails (MILN), undesired distal migration of the proximal fibula segment is prevented by tibiofibular stabilization, traditionally using a screw. A tightened cortical suspensory fixation rope (tether) is an alternative option, but its appropriateness has never been studied. The primary outcome was comparing the amount of proximal fibular migration between patients who were stabilized with either a tether or a screw. The secondary outcome was to evaluate the effect of fibular migration on the clinical outcome between both groups.

METHODS

A retrospective study was conducted on patients who underwent tibial lengthening with MILN between April 2016 and June 2022. Two cohorts were compared: 18 limbs with tether fixation versus 29 limbs with screw fixation. Data on the patient's age, sex, etiologies, and clinical outcomes were collected. Radiographic measurements included the lengthening distance and the amount of proximal fibular migration.

RESULTS

In total, 47 limbs from 41 patients, with average age 35.01 ± 13.72 years old. There were 28 males (68.29%) and 13 females (31.71%). The tether group demonstrated a statistically significant greater distance of migration than the screw group (p < 0.001), with an average migration distance of 8.39 ± 5.09 mm and 2.59 ± 3.06 mm, respectively. No correlation was found between the amount of tibial lengthening and the distance of proximal fibular migration in both the tether group (p = 0.96) and the screw group (p = 0.32). There was no significant difference in the change of knee extension between both groups (p = 0.3), and no patients reported knee pain or tightness.

CONCLUSION

A screw provides better resistance to proximal tibiofibular joint migration during MILN lengthening, but the difference appears clinically inconsequential. Either option appears suitable.

Outcomes of percutaneous femoral derotational osteotomy in pediatric patients

Background

Percutaneous femoral derotational osteotomies are performed in both adult and pediatric patients. There is little published on the outcomes after femoral derotational osteotomy in pediatric patients.

Methods

A retrospective cohort study of pediatric patients treated with percutaneous femoral derotational osteotomy by one of two surgeons between 2016 and 2022 was performed. Data collected included patient demographics; surgical indications; femoral version; tibial torsion; magnitude of rotational correction; complications; time to hardware removal; pre-operative and post-operative patient-reported outcome scores, including Limb Deformity-Scoliosis Research Society and Patient-Reported Outcomes Measurement Information System; and time to consolidation. Descriptive statistics were used to summarize the data and t tests used to compare means.

Results

Thirty-one femoral derotational osteotomies in 19 patients were included with an average age of 14.7 (9-17) years. The average rotational correction was 21.5° ± 6.4° (10°-40°). The average length of follow-up was 17.9 ± 6.7 months. There were no instances of nonunion, joint stiffness, or nerve injury. No patients returned to the operating room for additional surgeries other than routine hardware removal. There were no cases of avascular necrosis of the femoral head. Of the 19 patients, 8 completed both a pre-operative and post-operative survey set. There were significant improvements in the Limb Deformity-Scoliosis Research Society Self-Image/Appearance sub-category and the Patient-Reported Outcomes Measurement Information System Physical Function sub-category.

Conclusion

Femoral derotational osteotomy using a percutaneous drill hole technique with antegrade trochanteric entry femoral nail is safe in the pediatric population and improves self-image in patients with symptomatic femoral version abnormalities.

Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms

Aims

The Precice Stryde® internal magnetic lengthening nail allowed many patients a full weight-bearing experience during femur and tibia lengthening, but concerns over corrosion, pain and radiographic changes led to the implant's recall. Despite the recall, it is important to understand the rate of these occurrences and their influence on the overall success of the lengthening procedure. We aimed to investigate radiographic changes, patient-reported symptoms and bone healing indices for our cohort of Stryde lengthening.

Materials and methods

Our surgical database and electronic medical record system were used to review and document patient demographics, indications for lengthening, length achieved, bone healing index (BHI), location and type of radiographic changes, time until radiographic changes were first visible, presence of pain symptoms (not attributable to surgery or distraction), time to implant removal and if the pain symptoms resolved following implant extraction.

Results

From January 2019 to February 2021, 90 Stryde nails (78 femur and 12 tibia) were implanted in 63 patients. The cohort included 48 males and 15 females. The average length [± standard deviation (SD)] achieved was 58.4 ± 22.7 mm. The 66 bones (73%) developed radiographic changes and were found to be 58/78 (74%) femurs and 8/12 (67%) tibias. The average time to initial radiographic changes was 168 ± 108.1 days (femur) and 276 ± 126.8 days (tibia). Late-onset pain developed in 10 femur lengthening (11.1% of all nails) surgeries across eight patients (12.7% of all patients). All patients' pain resolved; three instances prior to nail removal and the remaining seven after nail removal. No patients were re-presented with worsening pain or radiographic changes following implant removal. Radiographic or symptomatic abnormalities did not impair bone formation. The BHI for femurs with (29.6 ± 16.6 days/cm, n = 58) vs without (29.4 ± 17.9 days/cm, n = 20) radiographic or symptomatic irregularity were nearly identical (p = 0.961). The difference between BHI for tibias with (39.3 ± 7.8 days/cm, n = 8) vs without (86.1 ± 38.2 days/cm, n = 4) radiographic changes was influenced by outliers and underpowered to draw a conclusion.

Conclusion

Bone lengthening with the Stryde nail was associated with high rates of radiographic abnormalities, but symptoms were uncommon and resolved with explantation. The radiographic changes did not affect bone healing in the femur.

Clinical significance

Radiographic changes including bone hypertrophy and osteolysis were common after bone lengthening with the Stryde nail, but the development of pain following consolidation was rare and resolved with implant removal.The BHI in femurs was not affected by radiographic changes.

How to cite this article

Reif TJ, Geffner A, Hoellwarth JS, et al. Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms. Strategies Trauma Limb Reconstr 2023;18(2):94-99.

Treatment of Angular Deformity and Limb Length Discrepancy With a Retrograde Femur Magnetic Intramedullary Nail: A Fixator-assisted, Blocking Screw Technique

BACKGROUND

Fixator-assisted nailing techniques that incorporate magnetic internal lengthening nails (MILNs) permit acute deformity correction and then gradual limb lengthening without needing postoperative external fixators.

PURPOSES

We sought to investigate the safety and accuracy of a fixator-assisted, blocking screw technique using retrograde MILNs for the correction of LLD and limb malalignment.

METHODS

Forty-one patients (13 patients with genu varum and 28 patients with genu valgum) with LLD treated with fixator-assisted, blocking screw retrograde MILN reconstruction were included. Preoperative LLD, mechanical axis deviation, and joint orientation angles were compared with values at the end of treatment, and bone healing indices were calculated. Perioperative complications were tracked.

RESULTS

Preoperatively, the mean mechanical lateral distal femoral angle of the varus cohort was 98 ± 12°, whereas the mean lateral distal femoral angle of the valgus cohort was 82±4°. Both cohorts had an average 3-cm LLD. 99% of the planned limb lengthening was achieved. Final LDFAs were 91 ± 6° and 89 ± 4° in the varus and valgus cohorts, respectively, and the limb mechanical axis angles were normalized. 10 patients underwent a total of 21 returns to the operating room. Most commonly, this involved percutaneous injection of bone marrow aspirate concentrate to bone regenerate exhibiting delayed union (6 patients).

CONCLUSIONS

The use of a retrograde MILN with a fixator-assisted, blocking screw technique is an effective means of acute deformity correction and gradual limb lengthening through minimal incisions. The accuracy of deformity correction relies on intraoperative execution of the appropriate nail start site, osteotomy location, and placement of blocking screws.

Radiographic findings involved in knee osteoarthritis progression are associated with pain symptom frequency and baseline disease severity: a population-level analysis using deep learning

PURPOSE

To (1) develop a deep-learning (DL) algorithm capable of producing limb-length and knee-alignment measurements, and (2) determine the association between limb-length discrepancy (LLD), coronal-plane alignment, osteoarthritis (OA) severity, and patient-reported knee pain.

METHODS

A multicenter, prospective patient cohort from the Osteoarthritis Initiative between 2004 and 2015 with full-limb standing radiographs at 12 month follow-up was included. A convolutional neural network was developed to automate measurements of the hip-knee-ankle (HKA) angle, femur, and tibia lengths, and LLD. At 12 month follow-up, patients reported their frequency of knee pain since enrollment and current level of knee pain.

RESULTS

A total of 1011 patients (2022 knees, 52.3% female) with an average age of 61.2 ± 9.0 years were included. The algorithm performed 12,312 measurements in 5.4 h. ICC values of HKA and LLD ranged between 0.87 and 1.00 when compared against trained radiologist measurements. Knees producing pain most days of the month were significantly more varus (mean HKA:- 3.9° ± 2.8°) or valgus (mean HKA:2.8° ± 2.3°) compared to knees that did not produce any pain (p < 0.05). In varus knees, those producing pain on most days were part of the shorter limb compared to nonpainful knees (p < 0.05). Baseline Kellgren-Lawrence grade was significantly associated with HKA magnitude, LLD, and pain frequency at 12 month follow-up (p < 0.05 all).

CONCLUSION

A higher frequency of knee pain was associated with more severe coronal plane deformity, with valgus deviation being one degree less than varus on average, suggesting that the knee tolerates less valgus deformation before symptoms become more consistent. Knee pain frequency was also associated with greater LLD and baseline KL grade, suggesting an association between radiographically apparent joint degeneration and pain frequency.

LEVEL OF EVIDENCE

IV case series.

STRYDE versus PRECICE magnetic internal lengthening nail for femur lengthening

INTRODUCTION

Magnetic internal lengthening nails (MILNs) have been used for femoral lengthening to avoid complications associated with external fixation. The titanium version of the MILN (PRECICE®) has been in use since 2011 but had limitations (50-75 lb) in post-operative weight bearing. A new stainless-steel version of the MILN (STRYDE®) allows 150-250 lb of post-operative weight bearing. The aim is to compare the outcomes of using these two different MILNs for both unilateral and bilateral femoral lengthening.

METHODS

A single-center, retrospective cohort study was conducted in which patients' records were reviewed from the period from January 2017 to March 2020. A total of 66 femoral lengthening procedures were included in the study and were divided into two groups: STRYDE® group (30 femora) and PRECICE® group (36 femora). Outcomes assessed were the 6-months post-operative Limb Deformity-Scoliosis Research Society (LD-SRS) Score, adjacent joint range of motion (ROM), average distraction rate, bone healing index (BHI), and complications.

RESULTS

No statistically significant difference was found between the two groups in regard to the (LD-SRS) score, hip ROM, or knee ROM. Statistically significant differences were found between the two groups in regard to BHI (average of 0.84 months/cm and 0.67 months/cm for STRYDE® and PRECICE®, respectively) and distraction rate (average of 0.6 mm/day and 0.9 mm/day for STRYDE® and PRECICE®, respectively). No mechanical nail complications were reported in the STRYDE® group compared to three events of nail failure in the PRECICE® group. One femur in the PRECICE® group needed BMAC injection for delayed healing compared to four femurs in the STRYDE® group.

CONCLUSION

The STRYDE® MILN yields comparable functional results to those of PRECICE® MILN and shows fewer mechanical nail complications. However, STRYDE® MILN requires a slower distraction rate and yields slower healing (larger BHI).

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Calcium sulfate in the management of osteomyelitis: A systematic review and meta-analysis of comparative studies

BACKGROUND

Calcium sulfate (CS) is used extensively as an antibiotic carrier in the treatment of chronic osteomyelitis, largely due to its biodegradable nature. The aim of this systematic review and meta-analysis is to analyze the comprehensive performance of CS in the literature when compared to other biomaterials or treatments for osteomyelitis. We assess the ability of CS to eradicate infection and achieve other key clinical outcomes.

METHODS

All studies comparing the use of CS to any other surgical technique for the surgical management of osteomyelitis were eligible for analysis. The indication for surgery in each case was chronic osteomyelitis. The minimum dataset required included details regarding infection eradication rates, union rates (in cases of nonunion), all-cause revision surgery and wound leakage. The primary outcome variables of concern were infection eradication and all-cause revision surgery. Secondary outcome variables included union and wound leakage. A random effects meta-analysis was performed.

RESULTS

Five studies were deemed eligible for inclusion. The CS group had a significantly higher rate of infection eradication (P = .013) and a significantly lower rate of revision for all causes (P < .001) when compared to the comparative group. In total, the CS group had 30 cases of wound leakage compared to 8 in the comparative group (P = .064).

CONCLUSION

CS demonstrates superior rates of infection eradication and all-cause revision when compared with alternative treatment methods for chronic osteomyelitis. While the current study reports on differing but nonsignificant rates of wound leakage between CS and other treatments, future studies are required to accurately investigate this clinically important complication.

Prophylaxis and treatment of infection in long bones using an antibiotic-loaded ceramic coating with interlocking intramedullary nails

Background: The study was done (1) to report on our recent experience with antibiotic-loaded calcium sulfate-coated interlocking intramedullary nails (CS-IMN) for infection prevention or infection eradication and (2) to compare the efficacy of CS-IMN versus antibiotic-loaded polymethylmethacrylate-coated IMN (PMMA-IMN) for infection eradication. Methods: We retrospectively reviewed the medical records of consecutive patients who underwent a limb salvage procedure for infection cure or infection prevention with PMMA-IMN or CS-IMN. We reviewed patient demographics, host-type, pre-operative infecting organisms, intraoperative cultures, as well as our main outcomes: infection control rate, achievement of union/fusion, and limb salvage. Results: 33 patients were treated with CS-IMN: 9 patients with goal of infection cure and 24 patients for infection prophylaxis. When used for infection prophylaxis, there was a 100 % ( 24 / 24 patients) prevention of infection rate, 95.5 % union rate ( 21 / 22 patients), and 100 % ( 24 / 24  patients) limb salvage rate. Nine patients were treated with CS-IMN to eradicate infection and were compared to a cohort of 28 patients who were treated with PMMA-IMN. The infection was eradicated in 7 / 9 patients (77.8 %) in the CS-IMN group versus 21/26 patients (80 %) in the PMMA-IMN group ( p = 0.44 ). Bone union/fusion was achieved in 8 / 9 patients (88.9 %) in the CS-IMN group versus 21/24 patients (87.5 %) in the PMMA-IMN group ( p = 0.11 ). The limb salvage rate in the CS-IMN group was 100 % ( 9 / 9  patients) versus 89 % ( 25 / 28  patients) in the PMMA-IMN group. Conclusions: CS-IMN are safe and easy to use, and we have therefore expended our indications for them. CS-IMN are very effective at infection prophylaxis in high-risk cases where infection is suspected. Early analysis suggests that CS-IMN are non-inferior to PMMA-IMN for infection eradication. This is our preliminary data that show this novel technique to be safe in a small cohort and may be as effective as the more established method. Future studies with larger cohorts of patients will be required to confirm these findings.

Osseointegration Amputation Reconstruction

Purpose of Review

To review the topic of osseointegration amputation reconstruction, which inserts a transcutaneous metal implant into the remaining intramedullary bone of a person with an amputation to facilitate a direct bone-anchored connection to an external prosthesis, eliminating the molded socket interface.

Recent Findings

Evidence continues to build that patients function better and have a higher quality of life with osseointegration implants compared with traditional socket prosthetics. The indications for osseointegration are expanding to additional patient populations and the long-term outcomes available are favorable which supports the continued refinement and utilization of the technology.

Summary

Osseointegration implants offer people with amputations freedom from burdensome socket prosthetics while improving function and quality of life. Mild infections at the skin interface are common but managed effectively with oral antibiotics and rarely lead to deep infection and implant removal. Other serious complications like hip or implant fracture are also uncommon. Additional long-term outcomes are needed along with technologic refinements, especially at the skin implant interface.

Lower Limb Deformity Correction: Analysis and Preoperative Planning

Lower limb deformities have a wide range of presentations and require significant preparation and planning from the surgeon to correct. It is important to provide a clear and systematic approach to preoperative planning for these cases and to detail three well-established correction techniques: external fixation, plate fixation, and intramedullary nail fixation. In using a simple mnemonic that lays out the systematic analysis of various axis lines and joint angles from proximal to distal in the lower extremity, deformities can be readily identified, and correction strategies can be effectively used to produce a successful deformity correction that restores colinear alignment to the lower limb. Additional pearls and pitfalls for these techniques are also provided to assist with some of the nuances that exist in the field.

Comparison and Validation of Preoperative Planning Techniques for Distal Femoral Osteotomies and Proximal Tibial Osteotomies

Preoperative planning is important for accurate intraoperative execution in many surgical fields. Planning for distal femoral osteotomies (DFOs) and proximal tibial osteotomies (PTOs) consists of choosing the level of the osteotomy, measuring the angle of the osteotomy based on hip-knee-ankle alignment, and choosing a proper osteotomy wedge size. Medical imaging IT solutions company Sectra has implemented a new osteotomy tool in their radiographic system that is simpler than the accepted standard of modified center of rotation of angulation (mCORA) technique, yet unvalidated. In this study, we aim to compare the Sectra osteotomy tool versus the mCORA technique to measure the osteotomy angles as well as wedge sizes in both DFOs and PTOs to validate this new tool.We enrolled n = 30 consecutive patients with DFOs and n = 30 PTOs from the last year. The Pearson correlation coefficient (PCC) along with descriptive statistics was used to evaluate for similarity between the two techniques. We also compared interobserver and intraobserver reliability using intraclass correlation coefficients (ICC).The PCC for osteotomy angles in DFOs and PTOs were both 0.998 (p < 0.001 for both). For wedge sizes, the PCC in DFOs was 0.993 and 0.980 in PTOs (p < 0.001 for both). ICCs were high for both interobserver measurements in osteotomy angles and wedge sizes (range: 0.989-0.999) as well as intraobserver measurements (0.994-0.999).The Sectra osteotomy tool is a validated tool for preoperative measurements of DFOs and PTOs. It is reliable and simpler than the current practice of the mCORA technique. We suggest future studies to analyze this Sectra osteotomy tool in other settings as to incorporate it into widespread clinical use.

Ankle distraction arthroplasty (ADA): A brief review and technical pearls

Ankle distraction arthroplasty (ADA) is a procedure based on the concept that mechanical unloading of an arthritic joint will initiate a healing response in the subchondral bone and articular cartilage. ADA utilizes the patient's own healing response, preserves joint motion, and is a great option for patients with osteoarthritis who are not ready for prosthetic arthroplasty or fusion. The procedure is well described and technically simple and adjunctive biologic therapies are exciting for joint regeneration. Complications are minor, and more serious adverse events are avoidable. Supramalleolar osteotomy pairs well with ankle distraction but requires some analysis and planning.

Intramedullary Antibiotic Depot Does Not Preclude Successful Intramedullary Lengthening or Compression

SUMMARY

The challenging problem of long bone infection and limb length difference cannot be addressed using only an antibiotic-coated nonmagnetic static nail. The combined use of resorbable calcium sulfate and magnetic lengthening nails offers a possible solution to this dilemma, as well as for infected nonunions that require compression. We present a combined technique to treat or prevent infection using femoral or tibial intramedullary antibiotic delivery with an absorbable calcium sulfate depot and concomitant internal lengthening or compression using a nail. Adequate débridement is required in cases of established infection and is a prerequisite for this technique.

Intentional Temporary Limb Deformation for Closure of Soft-Tissue Defects in Open Tibial Fractures

OBJECTIVES

(1) Evaluate intentional temporary limb deformation for closure of soft-tissue defects as a reconstruction strategy in open tibia fractures and (2) analyze the deformity parameters required for such reconstruction.

DESIGN

Multicenter retrospective cohort.

SETTING

Level I trauma center.

PATIENTS/PARTICIPANTS

Nineteen patients 18 years of age and older at the time of initial trauma, with a Gustilo-Anderson type IIIB or IIIC open tibia fracture treated with hexapod external fixation and intentional bony deformity created to facilitate soft-tissue closure.

INTERVENTION

Intentional limb deformation for soft-tissue closure, followed by gradual correction with a hexapod external fixator.

OUTCOME MEASUREMENTS

Radiographic healing, radiographic assessment of limb alignment, and functional and bony Application of the Method of Ilizarov Group score.

RESULTS

The average age was 45.3 (20-70), and 79% of patients were men. The most common mechanism of injury was motor vehicle accidents. The distal 1 of 5 of the tibia was the most common fracture location, with 37% of these involving the articular surface at the plafond. After wound closure, deformity correction was initiated after 30 days on average. Varus and apex posterior were the most common initial deformity required for primary soft-tissue closure. Bony and functional Application of the Method of Ilizarov Group outcomes were good or excellent in 94% of patients.

CONCLUSION

Intentional deformation followed by a gradual correction can be an effective strategy to obtain bone union and soft-tissue coverage in certain open fractures. This technique, in essence, converts these injuries from type IIIB to IIIA. This strategy obviates the need for flap coverage and results in satisfactory outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Core psychosocial issues for children and adolescents in the context of limb lengthening and reconstruction surgery treatment

PURPOSE

Addressing the psychosocial needs of adolescents can improve surgical outcomes. The aim of this retrospective comparative study was to understand the core psychosocial factors that shaped the experiences of adolescents who underwent multiple limb lengthening/reconstruction surgeries (LLRS).

METHODS

A novel 62-question survey was developed and administered to 31 patients from the study institution. Data was obtained using a self-report inventory assessing medical care, communication/connection to doctor, peer relations, physical space, self-esteem, counselling/clergy, physical/emotional support, school issues and concerns about future. This survey and demographic questions were administered to young adults (now aged 18 to 30 years) who underwent LLRS treatment between the ages of 11 to 20 years.

RESULTS

Psychosocial needs were determined to be within the categories of body image/self-esteem, subjective perception of treatment, patient-physician relationship, role of parents, peer interactions, academic performance and hospital experience. Patients valued parental involvement while also wanting their surgeon to speak directly to them. They preferred to be in private rooms on the paediatric floor and to not socialize while in the hospital. They were indifferent to keeping up with friends, speaking to a counsellor and having their surgeon inquire about their emotions. They expressed concern about pain, carrying out activities and the financial impact of surgery.

CONCLUSIONS

Adolescent LLRS patients value focused psychosocial support from their surgeon and caregivers. This perceived level of support influences their ability to cope with their condition. These findings helped us understand the psychological issues and preferences of adolescents who underwent LLRS and can assist orthopaedic surgeons in providing holistic care.

LEVEL OF EVIDENCE

IV.

A novel translation system for circular external fixation to correct translational bony deformities

Translational deformities are common complications of conservatively managed bone fractures and some surgically managed fractures with unstable patterns. Realigning the bones can be difficult when soft tissue, scars and calluses form. These deformities can be easily corrected with hexapodalic-based external fixators, but these fixators are not widely available in developing countries. We describe a stable and reliable Ilizarov frame that can be used to treat these deformities and show results of clinical cases.

A Staged Approach to Combined Extra-articular Limb Deformity Correction and Total Ankle Arthroplasty for End-Stage Ankle Arthritis

BACKGROUND

Patients presenting with end-stage ankle osteoarthritis (OA) in the setting of a concomitant extra-articular limb deformity pose a challenging problem that has not yet been described in the literature. We describe a case series of patients treated with external and internal fixation techniques followed by total ankle arthroplasty (TAA) in a staged approach to treat this complex presentation.

METHODS

Eight patients with limb deformity and end-stage ankle OA who underwent staged deformity correction and TAA from 2016 to 2019 at our institution were retrospectively identified. Average age was 58.5 (range, 49-68) years, with an average follow-up of 2.6 (range, 0.8-4.2) years. All patients underwent limb reconstruction with either tibial osteotomy with a circular frame (n=6) or intramedullary nail (n=2). Limb deformities consisted of the following: posttraumatic tibial malunion (2), limb length discrepancy (1), acquired tibial deformity (1), genu varum (2), or genu valgum (2). Radiographic parameters were assessed pre- and postoperatively on 51-inch standing and ankle radiographs: limb length discrepancy (LLD), genu varum/valgum deformity, recurvatum deformity, mechanical axis deviation, medial proximal tibial angle, lateral distal tibial angle, anterior distal tibial angle, and tibiotalar alignment. Pre- and postoperative patient-reported outcomes were assessed using 2 metrics, the Limb Deformity-Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores (Physical Function, Pain Intensity, Pain Interference, Global Physical Function, and Global Mental Function).

RESULTS

Following staged limb deformity correction and TAA, all patients achieved correction of LLD and angular deformities of the lower limb, along with restoration of normal alignment of the ankle joint. There was significant mean improvement in all patient-reported LD-SRS and PROMIS domains, except for LD-SRS mental health. LD-SRS function improved from 2.6 (±0.7) to 4.6 (±0.2), P = .008; pain improved from 2.9 (±0.9) to 4.8 (±0.2), P = .012; self-image improved from 2.9 (±0.4) to 4.7 (±0.3), P < .001; and total LD-SRS improved from 3.3 (±0.4) to 4.8 (±0.2), P = .002. Average satisfaction was 4.9 (±0.3). PROMIS physical function improved from 32.3 (±6.8) to 51.3 (±5.3), P = .008; pain interference improved from 66.0 (±9.1) to 41.3 (±6.2), P = .004; pain intensity improved from 60.0 (±13.3) to 33.1 (±5.3), P = .007; global physical health improved from 39.3 (±6.8) to 60.7 (±5.1), P = .002; global mental health improved from 54.8 (±5.9) to 65.6 (±2.8), P = .007. There was one incidence of pin site infection and one reoperation.

CONCLUSION

Deformity correction with either external frame or intramedullary nail fixation followed by TAA in a staged approach was a viable surgical option in the treatment of end-stage ankle OA with concurrent extra-articular limb deformity. This unique approach was capable of achieving deformity correction with improved patient-reported outcomes, minimal complications, and good patient satisfaction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Cost Comparison of Tibial Distraction Osteogenesis Using External Lengthening and Then Nailing vs Internal Magnetic Lengthening Nails

Aim and objective

Tibial lengthening can be performed by distraction osteogenesis via lengthening and then nailing (LATN) or by using a magnetic lengthening nail (MLN). MLN avoids the complications of external fixation while providing accurate and easily controlled lengthening. Concerns exist still regarding the high upfront cost of the magnetic nail, which serves to limit its use in resource-poor areas and decrease adoption among cost-conscious surgeons. The purpose of this study was to compare the hospital, surgeon, and total cost between LATN and MLN when used for tibial lengthening.

Materials and methods

A retrospective review was performed comparing consecutive tibial lengthening using either LATN (n = 17) or MLN (n = 15). The number of surgical procedures and time to union were compared. Surgeon and hospital payments were used to perform cost analysis after adjusting for inflation using the consumer price index (CPI).

Results

Patients treated with MLN underwent fewer surgeries (3.6 vs 2.8; p < 0.001) but had a longer time to union as compared with patients treated with LATN (19.79 vs 27.84 weeks; p = 0.006). Total costs were similar ($50,345 vs $46,162; p = 0.249) although surgeon fees were lower for MLN as compared with LATN ($6,426 vs $4,428; p < 0.001).

Conclusion

LATN and MLN had similar overall costs in patients undergoing tibial lengthening. MLN was associated with fewer procedures but a longer time to union as compared with LATN.

Clinical significance

Despite an increased upfront cost in MLN, there was no difference in total cost between LATN and MLN when used for tibial lengthening. Thus, in cases where either method is feasible, cost may not be a deciding factor when selecting the appropriate treatment.

How to cite this article

Dvorzhinskiy A, Zhang DT, Fragomen AT, et al. Cost Comparison of Tibial Distraction Osteogenesis Using External Lengthening and Then Nailing vs Internal Magnetic Lengthening Nails. Strategies Trauma Limb Reconstr 2021;16(1):14-19.

Antibiotic Cement-Coated interlocking Intramedullary Nails in the Treatment of Septic Complex Lower Extremity Reconstruction; A Retrospective Analysis with Two year Minimum Follow up

Background: To report on our experience with antibiotic cement coated interlocking intramedullary nails (ACC-IMNs) for limb salvage in septic complex lower extremity reconstruction with a minimum of 2-year follow up. Methods: We retrospectively reviewed the records of all consecutive patients who underwent a limb salvage procedure with ACC-IMNs. We reviewed patients' demographics, the preoperative infecting organism, and host type, time to bone union, complications, limb salvage rates, and infection control rates. Results: There were 28 patients with a mean age of 62 years (range 22-88). The mean follow up period was 40 months (range 28-84). The ACC-IMNs were used in 14 patients (50 %) to achieve knee fusion after failed revisions of infected total knee arthroplasty, in 8 patients (28%) for septic tibial nonunion, and in 6 patients (21%) with ankle fusion nonunions. Bony union/fusion was achieved in 87 % (21/24) of patients. The infection was controlled in 80% (21/26) of patients. Four out the five patients who had recurrent infection were type B hosts (p=0.63). The limb salvage rate was 89% (25/28). The overall complication rate was 32%. Conclusions: The use of ACC-IMNs was an effective treatment strategy and associated with high limb salvage and bone union rates. Furthermore, the infection recurrence rate was low. Knee fusion patients after failed TKA should be counseled preoperatively for a potential high complication rate.

Tranexamic Acid Reduces Postoperative Blood Loss in Distal Femoral Osteotomy

Blood loss remains a significant source of morbidity and mortality in orthopaedic surgery, with transfusions associated with an increased risk of infection, length of stay, delayed rehabilitation, and significantly increased hospitalization costs. The purpose of this study was to assess whether the use of tranexamic acid (TXA) is effective in reducing postoperative blood loss in patients undergoing distal femoral osteotomy (DFO). A retrospective review was performed of all patients undergoing DFO by a single surgeon from 2010 to 2017, with a change in protocol occurring in 2014, after which all patients received TXA. Patients in the TXA group (n = 24) received 1-g TXA immediately prior to incision followed by a second dose of 1-g TXA 4 hours after the administration of the first dose. Patients in the control group (n = 28) did not receive TXA. Drainage was recorded through a subfascial drain that remained for 24 hours postoperatively. Postoperative hemoglobin, hematocrit, and transfusions, as well as demographic factors, including age, gender, body mass index (BMI), medical comorbidities, and ASA (American Society of Anesthesiologists) class, were recorded. Multivariate regression analysis adjusting for potential confounding variables was performed. With the exception of gender, the two groups did not differ significantly in baseline characteristics, including age, BMI, and ASA class. There was a significant difference in postoperative blood loss, with those receiving TXA having a mean drain output of 184.2 versus 242.1 mL for the control group (p = 0.02), which persisted after regression analysis (p < 0.005). Blood loss differed between patients who received one (250 mL) dose and those who received two (162.2 mL) doses of TXA, although this difference was insignificant (p = 0.489). There were no differences in postoperative hemoglobin and hematocrit levels. One patient (control group) required blood transfusion postoperatively. There were no complications related to TXA. In conclusion, TXA results in less postoperative blood loss in DFO, with the most pronounced effect in those who receive two doses. Future research should involve a larger, prospective study to assess for differences in postoperative hemoglobin/hematocrit levels and transfusion rates.

Biomechanical and Functional Improvements Gained by Proximal Tibia Osteotomy Correction of Genu Varum in Patients with Knee Pain

BACKGROUND

Mechanical axis malalignment contributes to abnormal forces across the knee joint. Genu varum, or increased medial mechanical axis deviation (MAD), increases force transmission and contact pressures to the medial compartment. With increasing MAD and femoral-tibial mechanical axis angle (MAA), contact forces within the medial or lateral compartment of the knee significantly increase with increasing deformity. This may lead to knee pain, further deformity, and medial compartment degenerative joint disease, which can interfere with participation in sports and diminish quality of life.

PURPOSES/QUESTIONS

We sought to evaluate patients with knee pain with bilateral genu varum and determine the effect of bilateral proximal tibial osteotomies on knee biomechanics, deformity correction, and functional outcomes.

METHODS

This was a single-center, prospective study of eight limbs in four patients. Consecutive patients presenting with knee pain and bilateral genu varum originating from the proximal tibia were included. All patients underwent staged bilateral proximal tibial osteotomies with gradual deformity correction with an external fixator. Subjects underwent a three-dimensional (3D) instrumented motion analysis during level walking. A 3D lower extremity model was built and bilateral knee frontal plane kinematics and kinetics during the stance phase of gait were determined. Radiographic analysis was performed including assessment of MAD, MAA, and medial proximal tibial angle (MPTA). Functional outcomes were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS), the 36-item Short-Form Survey (SF-36), the Lower Limb Questionnaire (LLQ), and a visual analog scale (VAS) for pain.

RESULTS

The average time in the external fixator for a single limb was 97 days. The average follow-up period was 310 days. All biomechanical outcomes significantly improved, including knee adduction angle (7.8° to 1.8°), knee adduction moments (first peak, - 0.450 to - 0.281 nm/kg, and second peak, - 0.381 to - 0.244 nm/kg), and knee adduction moment impulse (- 0.233 to - 0.150 nm s/kg). There was a significant improvement in MAA, MAD, and MPTA. All patients showed qualitative improvement in mean scores on VAS (11.8 to 0.0), LLQ (77 to 93), KOOS (64 to 84), and SF-36 (71 to 88).

CONCLUSION

These findings suggest that bilateral proximal tibial osteotomy may be effective in improving knee biomechanics during gait and correcting mechanical alignment in patients with bilateral genu varum. Patients also demonstrated improvement in functional outcome scores. This technique should thus be considered in patients with varus knee osteoarthritis in the setting of genu varum to alleviate symptoms and potentially decrease further clinical deterioration.

Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty

Background

Ankle distraction arthroplasty has emerged as an alternative treatment for ankle arthritis. There are few reports on the magnetic resonance imaging (MRI) findings after distraction arthroplasty. This study sought to determine whether there are positive changes on MRI after ankle distraction and improvements on X-ray. Additionally, patient-reported outcomes and joint range of motion (ROM) after ankle distraction are described.

Materials and methods

Thirty-two patients (mean age 49 years) who underwent ankle distraction had pre-operative and one-year postoperative MRIs, which were graded using a modified whole-organ magnetic resonance imaging score (WORMS). Ankle joint space and ROM were measured. A non-validated three-item questionnaire was administered to assess functional outcomes.

Results

Although the anterior quadrant of the ankle showed a trend to improvement in cartilage morphology on the postoperative MRI, the WORMS did not demonstrate a significant difference in any of its subcategories. While reduction in joint osteophytes was observed and maintained short term, this was mainly due to resection intraoperatively. X-rays revealed a significant increase in joint space, and there was a significant increase in ankle dorsiflexion. Eight-seven percent of the patients were satisfied with their functional outcome.

Conclusion

At short-term follow-up, MRI scores after ankle distraction arthroplasty did not demonstrate significant improvement despite positive changes on X-ray and improved clinical outcomes and ankle ROM. Further study on larger patient numbers with longer follow-up is required.

Level of evidence

IV, Case Series

How to cite this article

Haleem AM, Galal S, Nwawka OK, et al. Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty. Strategies Trauma Limb Reconstr 2020;15(3):157–162.

Chronic Osteomyelitis of the tibia and ankle treated with Limb Salvage Reconstruction

Introduction: To confirm the success of our limb salvage treatment protocol and determine what factors are predictive of success versus failure in limb salvage techniques for patients with chronic osteomyelitis of the tibia and ankle.

Methods: Retrospective case series analyzing factors and outcomes in patients who underwent limb salvage techniques for chronic osteomyelitis of tibia or ankle. Main outcome measurements included infection controlled without the need for amputation or chronic antibiotic suppression and union of infected non-unions.

Results: Mean follow-up was 3.9 years. Out of the sixty-seven patients (mean age: 51.4 years) treated for chronic osteomyelitis, fifty-four had an associated non-union. Sixty-one patients (91.0%) had their infection controlled by limb salvage. Five ultimately required amputation and one remained on daily chronic antibiotics. Diabetics complicated with neuropathy and increasing numbers of limb salvage surgeries were associated with a significantly higher failure rate. Forty-eight out of fifty-four patients (88.9%) also had successful healing of their infected non-union. Diabetes and need for more limb salvage surgeries were also found to have a significantly higher failure rate.

Conclusions: Limb salvage is a reliable and successful treatment for patients with chronic osteomyelitis and infected non-unions of the lower extremities. Diabetic neuropathy is a risk factor that impedes success.

Level of Evidence: Prognostic Level IV.

Effects of a Medial Knee Unloading Implant on Tibiofemoral Joint Mechanics During Walking

The Atlas™ unicompartmental knee system is a second-generation extra-articular unloading implant for patients with mild to moderate medial knee osteoarthritis. The technology acts to reduce a portion of the weight-bearing load exerted on the medial knee during physical activity thereby, reducing the mechanical stress imposed on a degenerative joint. The purpose of the present study was to evaluate the effects of the Atlas™ on tibiofemoral joint mechanics during walking. A computer-aided design assembly of the Atlas™ was virtually implanted on the medial aspect of a previously validated finite element tibiofemoral joint model. Data for knee joint forces and moments from an anthropometrically matched male were applied to the model to quasi-statically simulate the stance phase of gait. Predictions of tibiofemoral joint mechanics were computed pre- and post-virtual implantation of the Atlas™. Compressive force in the medial tibiofemoral compartment was reduced by a mean of 53%, resulting in the decrement of mean cartilage-cartilage and cartilage-meniscus von Mises stress by 31% and 32%, respectively. The Atlas™ was not predicted to transfer net loading to the lateral compartment. The tibiofemoral joint model exhibited less internal-external rotation and anterior-posterior translation post-Atlas™, indicating a change in the kinematic environment of the knee. From a biomechanical perspective, extra-articular joint unloading may serve as a treatment option for patients recalcitrant to conservative care. Evaluation of mechanical changes in the tibiofemoral joint demonstrate the potential treatment mechanism of the Atlas™, in accordance with the available clinical data. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2149-2156, 2019.

Carbon-Fiber-Reinforced Polymer Intramedullary Nails Perform Poorly in Long-Bone Surgery

BACKGROUND

Carbon-fiber-reinforced (CFR) polymer has produced great excitement in the orthopedic community as a material that will reduce bone healing times and provide improved image quality. Osteotomy stabilized with an intramedullary (IM) nail has become a common technique to address post-traumatic malalignment of the lower extremity.

PURPOSES/QUESTIONS

The following questions were asked: (1) Did CFR polymer nails provide a rapid healing time after long bone osteotomy, shortening, or fracture? (2) Did the CFR polymer nails produce unexpected complications?

METHODS

A retrospective review was conducted in patients who received CFR polymer IM nails for various indications, from April 2016 to January 2017 in a deformity and trauma practice, using patient charts and radiographs. The primary outcomes were time to union and incidence of complications including nonunion, hardware failure, neurovascular injury, venous thromboembolism, and infection.

RESULTS

Twelve patients who received CFR polymer IM nails in 16 limbs for various indications were included in our analysis. Patients were followed for an average of 16.9 months. Eleven limbs underwent realignment and were corrected an average of 23° through a diaphyseal osteotomy. Three limbs underwent limb-shortening surgery, an average of 25 mm, through an open, excisional osteotomy of the femoral diaphysis. Two diaphyseal, closed tibia fractures underwent routine IM nailing. The average time to union was 107.6 days, which included all limbs that united (11/16, 69%). Nonunion occurred in 5/16 (31%) of limbs. Complications recorded included nonunion and hardware failure, most of which resulted in unplanned surgery.

CONCLUSIONS

The use of the CFR polymer IM nail was associated with loss of fixation and nonunion after surgeries that have traditionally healed uneventfully. The increased elasticity of the CFR polymer allows for more motion at the osteotomy/fracture interface than the stiffer titanium counterparts, exposing long-bone osteotomies to delayed union and nonunion, a finding seen with CFR polymer plates. The overwhelmingly poor early results of this device applied to a long-bone deformity practice have led these authors to abandon the use of this implant.

Metacarpal Lengthening in Adults With Brachymetacarpia

BACKGROUND

Metacarpal lengthening by distraction osteogenesis has been well documented in pediatric patients but limited in older patients. Fewer studies have assessed the success of the procedure through outcome measure scores. The purpose of this study is to assess the outcomes of distraction osteogenesis in skeletally mature adults with brachymetacarpia and patients' perspectives on their satisfaction through outcome measure scores.

METHODS

Retrospective chart review of a consecutive series of metacarpal lengthenings for the treatment of brachymetacarpia was performed. Key parameters collected include starting metacarpal length, amount lengthened, range of motion of metacarpophalangeal joint, type of fixator used, distraction time, and total time in fixator. Relevant comorbidities and complications encountered were recorded as well. The Body Image Quality of Life Inventory (BIQLI) and Limb Deformity Modified Scoliosis Research Society (LD-SRS) score were given to evaluate patients' perspectives on their satisfaction of surgery.

RESULTS

Seven metacarpal lengthenings were performed in 4 adult females (average age: 22.8 years) between 2005 and 2016. The average amount lengthened was 1.5 cm (range, 1.2-2.1 cm), corresponding to a mean percent lengthening of 44.4% (range, 33.3%-57.1%). The mean distraction rate was 0.432 mm/day (range, 0.286-0.724 mm/day). The mean distraction time was 38 days (range, 28-55 days). External fixation index was 71.8 days/cm (range, 53.5-99.2 days/cm). No functional loss was observed.

CONCLUSIONS

Progressive distraction osteogenesis can obtain functionally successful results and improvement in aesthetics and body image without severe complications in skeletally mature adults with brachymetacarpia.

Genomewide Association Study of Fracture Nonunion Using Electronic Health Records

Nonunion is a clinically significant complication of fracture associated with worse outcomes, including increased pain, disability, and higher healthcare costs. The risk for nonunion is likely to be complex and multifactorial, and as such, the biology underlying such risk remains poorly understood. Genetic studies represent one approach to identify implicated biology for further investigation, but to date the lack of large cohorts for study has limited such efforts. We utilized the electronic health records of two large academic medical centers in Boston to identify individuals with fracture nonunion and control individuals with fracture but no evidence of nonunion. We conducted a genomewide association study among 1760 individuals of Northern European ancestry with upper or lower extremity fracture, including 131 with nonunion, to examine whether common variants were associated with nonunion in this cohort. In all, one locus in the Calcyon (CALY) gene exceeded a genomewide threshold for statistical significance (p = 1.95e-8), with eight additional loci associated with p < 5e-7. Previously reported candidate genes were not supported by this analysis. Electronic health records should facilitate identification of common genetic variations associated with adverse orthopedic outcomes. The loci we identified in this small cohort require replication and further study to characterize mechanism of action, but represent a starting point for the investigation of genetic liability for this costly outcome.

Blocking Screw-assisted Intramedullary Nailing Using the Reverse-rule-of-thumbs for Limb Lengthening and Deformity Correction

Introduction

Historically, blocking screws have been used to assist in acute reduction of fractures during intramedullary (IM) nailing. The reverse-rule-of-thumbs (RROT) for blocking screws was introduced to facilitate internal lengthening nail use in deformity correction and limb lengthening. Our study investigated the ability of blocking screws, using same principle, to accurately correct long-bone deformity with and without lengthening and to prevent lengthening-induced deformity.

Materials and methods

This is an institutional review board (IRB)-approved retrospective study on 86 patients who had IM nail-assisted limb reconstruction of femur or tibia with blocking screws. Surgeries were performed for deformity correction, limb lengthening, or deformity correction and limb lengthening. Data on the following variables were collected: number of blocking screws, distance of each blocking screw to osteotomy, distance of osteotomy from joint line, and amount of lengthening. Mechanical axis deviation (MAD) and joint alignment parameters were measured preoperatively and at the final postoperative follow-up. The primary outcome was the ability to obtain desired MAD and joint orientation angles. Accuracies were reported as postoperative measurements relative to goal. Association for the Study and Applications of the Methods of Ilizarov (ASAMI) scores were collected.

Results

The accuracy of deformity correction was within 6 mm from goal, while joint orientation was corrected to within 1.5° of goal. Number of blocking screws did not significantly impact accuracy. Distance of blocking screw to osteotomy and amount of lengthening did not affect accuracy. In femurs, osteotomies greater than 10 cm from the joint line were more accurate in MAD goal (p = 0.017). This result was not replicated in tibias. ASAMI scores were excellent or good.

Conclusion

Using RROT configuration, blocking screws were effective in correcting deformities of lower extremity long bones and in preventing deformity during limb lengthening. If positioned correctly, number of screws and their distance to osteotomy did not affect accuracy. Amount of lengthening did not impact accuracy. Distal femoral osteotomy less than 10 cm from knee joint may be challenging even with using blocking screws.

How to cite this article

Dabash S, Zhang DT, Rozbruch SR, et al. Blocking Screw-assisted Intramedullary Nailing Using the Reverse-rule-of-thumbs for Limb Lengthening and Deformity Correction. Strategies Trauma Limb Reconstr 2019;14(2):77–84.

The PRECICE magnetic IM compression nail for long bone nonunions: a preliminary report

INTRODUCTION

The magnetic intramedullary (IM) compression nail is capable of providing sustained compression for the treatment of nonunions of long bones. This ability was previously only possible with the use of external fixation. We asked the following questions: How effective is the IM compression nail at achieving union? How do we know when adequate compression has been attained? Which types of nonunions are good candidates for this treatment?

MATERIALS AND METHODS

Fourteen patients with nonunions of the tibia (5) or femur (9) were treated with the PRECICE IM compression nail. The average age was 49 years number of previous surgeries was 1.9, 7 were atrophic and 7 normotrophic, 3 were metaphyseal and 11 diaphyseal. All PRECICE IM nails were pre-distracted prior to implantation. Compression was applied post-operatively until the locking bolts were seen on X-ray to be bending or the nail was no longer shortening despite applying the external magnet.

RESULTS

Union was achieved in 13/14 cases. The time to union was 24.5 weeks (range 11-60). The two proximal tibia metaphyseal nonunions, both deformed into varus (4°) and flexion (10°) after compression was applied with one failing to unite. The distal tibia metaphyseal and diaphyseal nonunions did not deform upon compression. Three patients had positive cultures and were treated with IV antibiotics for 6 weeks followed by 3 months of oral suppression without subsequent infection. No mechanical nail failures were seen.

CONCLUSIONS

The IM compression nail was successful at applying compression, preventing deformity, and obtaining union in all diaphyseal and in distal tibia metaphyseal nonunions. Signs of active compression are bending of the locking bolts and failure of the nail to shorten. Proximal tibia metaphyseal nonunion may not be suited for this treatment.

A Preliminary Comparison Suggests Poor Performance of Carbon Fiber Reinforced Versus Titanium Plates in Distal Femoral Osteotomy

BACKGROUND

Carbon fiber-reinforced (CFR) polymer implants have theoretical advantages over titanium plates.

QUESTIONS/PURPOSES

The aim of the present study was to assess our early outcomes with CFR plates in lateral opening-wedge distal femoral osteotomy to correct valgus lower limb malalignment. We asked the following: (1) Did the CFR polymer implant change time to union when compared with the titanium implant? (2) Did the incidence of displacement of medial cortical fractures differ between the implants? (3) Did the incidence of complications differ between the two techniques, and did other factors, such as bone graft material used, affect healing?

METHODS

A retrospective review of 16 limbs treated with an opening-wedge distal femoral osteotomy for genu valgum using either titanium (n = 10) or CFR plates (n = 6) was performed. Patient and clinical covariates as well as the primary outcome of time to union and secondary outcome of fracture displacement were collected and analyzed.

RESULTS

Those treated with CFR plates had longer times to union than did those in the titanium-treated group (median, 121.5 vs 81.5 days, respectively). The incidence of fracture displacement was higher in the CFR plate-treated group (CFR, n = 5/6; titanium, n = 1/10). Although the CFR plate-treated group had a 33% nonunion incidence while the titanium group had no nonunions, the study lacked the power to show significance. Bone graft material used did not affect outcome. Complication rates were higher in the CFR plate-treated patients.

CONCLUSION

The CFR plate was associated with a longer time to unite and higher fracture displacement rate than the titanium plate. As this is a retrospective case series, further research is required to confirm these results and clarify best practices in plating of distal femoral osteotomy for deformity correction.

A Comparison of Femoral Lengthening Methods Favors the Magnetic Internal Lengthening Nail When Compared with Lengthening Over a Nail

BACKGROUND

Bone lengthening with an internal lengthening nail (ILN) avoids the need for external fixation and requires one less surgical procedure than lengthening over a nail (LON). However, LON has been shown to be superior to femoral internal lengthening using a mechanical nail. The magnetic ILN, a remote-controlled and magnet-driven device, may have overcome the weaknesses of earlier internal lengthening technology and may be superior to LON.

QUESTIONS/PURPOSES

(1) Is the magnetic ILN more accurate than LON for femoral lengthening? (2) Does the magnetic ILN demonstrate more precise distraction rate control than LON? (3) Does the magnetic ILN result in faster regenerate site healing, with more robust callus, than LON? (4) Does the magnetic ILN result in fewer complications, including impediments to knee motion, than LON?

METHODS

We conducted a retrospective comparison of the records and radiographs of 21 consecutive patients with 22 femoral lengthenings using LONs and 35 consecutive patients with 40 femoral lengthenings using remote-controlled magnetic ILNs. Primary outcomes measured included accuracy, distraction rate precision, time to bony union, final knee range of motion, regenerate quality, and complications. The minimum follow-up times for the LON and ILN cohorts were 13 and 21 months, respectively.

RESULTS

Patients treated with ILN had a lower post-treatment residual limb-length discrepancy (0.3 mm) than those treated with LON (3.6 mm). The rate of distraction was closer to the goal of 1 mm/day and more tightly controlled for the ILN cohort (1 mm/day) than that for the LON group (0.8 mm/day; SD, 0.2). Regenerate quality was not significantly different between the cohorts. Bone healing index for ILN was not statistically significant. Time to union was shorter in the ILN group (3.3 months) than that in the LON group (4.5 months). A lower percentage of patients experienced a complication in the ILN group (18%) than in the LON group (45%). Knee flexion at the end of distraction was greater for ILN patients (105°) than that for LON patients (88.8°), but this difference was no longer observed after 1 year.

CONCLUSIONS

Femoral lengthening with magnetic ILN was more accurate than with LON. The magnetic ILN comports the additional advantage of greater precision with distraction rate control and fewer complications. Both techniques afford reliable healing and do not significantly affect knee motion at the final follow-up. The magnetic ILN method showed no superiority in regenerate quality and healing rate.

Does the Surgical Correction of Tibial Torsion with Genu Varum Produce Outcomes Similar to Those in Varus Correction Alone?

The aim of this article is to study the relationship between tibia vara and external tibial torsion in adults. The following questions were asked: (1) what is the incidence of rotational deformity in patients with genu varum and (2) do patients who undergo correction of tibial torsion with genu varum have similar outcomes to those who undergo simple tibia vara correction? In this study, 69 patients (138 limbs) underwent bilateral proximal tibial osteotomy for the correction of genu varum. Patients with simple coronal plane deformity (varus alone) were treated with either a monolateral external fixator or a hexapod frame. Those with concomitant external tibial torsion were treated with circular external fixation. The primary outcome was the ability to achieve the desired correction of alignment in the coronal, sagittal, and axial planes. Secondary outcomes included a postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) and a routine patient satisfaction questionnaire. The incidence of tibial torsion among the entire group of patients with bilateral tibia vara was 46% and overwhelmingly external in direction. The two groups had some significant differences in demographics with torsion patients tending to be younger and thinner. The final mechanical axis deviation and medial proximal tibial angle values for both groups did not differ significantly (p = 0.956). The postcorrection thigh-foot axis was not significantly different between the two groups (p = 0.666). Time to union was not significant (p > 0.999). KOOS was not different between the two groups in symptoms, pain, activities of daily living, and return to sport. There was a difference in the quality of life score between the two groups (p = 0.044). There was no difference between the two groups regarding the patient questionnaire. Based on the finding of this analysis, the incidence of rotational malalignment with genu varum is close to 50%. The recognition of this close association with external tibial torsion deformity may allow for further insights into the role of rotation in varus deformity-related knee pathology and treatment. Patients can expect nearly identical outcomes from this surgery.

Predicting the Feasibility of Correcting Mechanical Axis in Large Varus Deformities With Unicompartmental Knee Arthroplasty

BACKGROUND

Due to disappointing historical outcomes of unicompartmental knee arthroplasty (UKA), Kozinn and Scott proposed strict selection criteria, including preoperative varus alignment of ≤15°, to improve the outcomes of UKA. No studies to date, however, have assessed the feasibility of correcting large preoperative varus deformities with UKA surgery. The study goals were therefore to (1) assess to what extent patients with large varus deformities could be corrected and (2) determine radiographic parameters to predict sufficient correction.

METHODS

In 200 consecutive robotic-arm assisted medial UKA patients with large preoperative varus deformities (≥7°), the mechanical axis angle (MAA) and joint line convergence angle (JLCA) were measured on hip-knee-ankle radiographs. It was assessed what number of patients were corrected to optimal (≤4°) and acceptable (5°-7°) alignment, and whether the feasibility of this correction could be predicted using an estimated MAA (eMAA, preoperative MAA-JLCA) using regression analyses.

RESULTS

Mean preoperative MAA was 10° of varus (range, 7°-18°), JLCA was 5° (1°-12°), postoperative MAA was 4° of varus (-3° to 8°), and correction was 6° (1°-14°). Postoperative optimal alignment was achieved in 62% and acceptable alignment in 36%. The eMAA was a significant predictor for optimal postoperative alignment, when corrected for age and gender (P < .001).

CONCLUSION

Patients with large preoperative varus deformities (7°-18°) could be considered candidates for medial UKA, as 98% was corrected to optimal or acceptable alignment, although cautious approach is needed in deformities >15°. Furthermore, it was noted that the feasibility of achieving optimal alignment could be predicted using the preoperative MAA, JLCA, and age.

Retrograde magnetic internal lengthening nail for acute femoral deformity correction and limb lengthening

INTRODUCTION

The Precice magnetic internal lengthening intramedullary nail is being used with great success in femur lengthening and deformity correction with a retrograde approach. Areas Covered: Our personal history of limb lengthening and the Precice nail will be reviewed. Several technical aspects are discussed including design updates, pre operative planning, selection of nail length, the use of blocking screws and intra operative temporary external fixation, osteotomy practice, post operative management, and cost analysis. Expert Commentary: The phenomenal bone healing ability for the retrograde Precice nail after femoral osteotomy for lengthening, even after acute deformity correction, is recognized throughout the growing body of scientific publications on this topic. The few failures that have occurred appear to be attributable to excessive loading of the femur and implant during a vulnerable time of bone healing. Further studies with more uniform outcome criteria need to be conducted to better standardize user's experiences. The higher one time cost of the implant is offset by the reduced number of surgeries needed when compared with the gold standard of lengthening-over-nail-technique, and we suspect that patients return to work sooner due to the ability to wear normal clothing and the reduction in pain throughout the entire lengthening process.