Limb salvage reconstruction of the lower limb with complex ankle arthrodesis and magnetic internal lengthening nail.

PURPOSE: With advances in orthopedic implants, the use of intramedullary lengthening devices has gained increasing popularity as an alternative technique compared to lengthening with external fixators, with alleged comparable or better outcomes. The aim of this study is to report our single-center technique and outcomes of combined ankle arthrodesis and proximal tibial lengthening using external fixator with a motorized intramedullary nail, respectively. METHOD: Fourteen patients with post-traumatic advanced ankle arthritis underwent staged ankle arthrodesis with external fixator and proximal tibial lengthening using the PRECICE® ILN. Amount of shortening, length achieved, bone healing index, infection rate, ankle fusion rate, and ASAMI score were evaluated. RESULTS: The average age was 44 years old (range, 30-62). The mean follow up is 70 months (range, 43-121.4). The average amount of limb shortening for patients after ankle fusion was 36.7 mm (18-50) while lengthening was 35.9 mm (range, 18-50). Patients had the nail implanted for an average of 479 days (range, 248-730). Ankle fusions were healed in an average of 178.3 days. There were no surgical infections. All osteotomy-lengthening sites healed after an average 202 days (106-365). The mean bone healing index (BHI) was 56.0 days/cm (21.2-123.6) among the whole cohort. There were no cases of nonunion. ASAMI bone scores were excellent or good among all patients. CONCLUSION: Ankle arthrodesis with external fixation along with proximal tibial lengthening using motorized IMN yielded high rates of fusion and successful lengthening. This technique could be offered as a reasonable alternative to using external fixation for both purposes. LEVEL OF EVIDENCE: Level IV, Retrospective cohort study.

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.

Ankle Distraction Arthroplasty: A Survivorship Review and Meta-Analysis.

Multiple treatments exist for ankle osteoarthritis. Ankle arthrodesis is the gold standard in late-stage osteoarthritis, but sacrifices range of motion and risks nonunion. Total ankle arthroplasty is typically reserved for low-demand patients as the long-term outcomes are poor. Ankle distraction arthroplasty is a joint sparing procedure which utilizes external fixator frame to unload the joint. This promotes chondral repair and improves function. This study aimed to organize clinical data and survivorship in published papers and direct further research efforts. Thirty-one publications were evaluated and 16 were included in the meta-analysis. The Modified Coleman Methodology Score was used to assess quality of the individual publications. Random effects models were used to estimate the failure risk after ankle distraction arthroplasty. Ankle Osteoarthritis Score (AOS), American Orthopedic Foot and Ankle Score (AOFAS), Van Valburg, and Visual Analog Scores (VAS) all improved postoperatively. Random effects model analysis revealed an overall failure ratio of 11% (95% CI: 7%-15%; p value ≤ .001; I2 = 87.01%) after 46.68 ± 7.17 months follow up, 9% (95% CI: 5%-12%; p value≤0.001 I2=81.59%) with less than 5 years follow-up and 28% (95% CI: 16%-41%; p value≤0.001 I2=69.03%) for patients with more than 5 years follow-up. Ankle Distraction Arthroplasty has promising short to intermediate term outcomes which makes this a reasonable treatment option to delay joint sacrificing surgery. The selection of the optimal candidates and consistent technique would improve research and subsequently outcomes. Based on our meta-analysis, negative prognostic factors include female sex, obesity, ROM < 20°, leg muscle weakness, high activity level, low preoperative pain levels, higher preoperative clinical scores, inflammatory arthritis, septic arthritis, and deformity.

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.

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.

Limb Lengthening in Russell-Silver Syndrome: An Update Confirming Safe and Speedy Healing.

INTRODUCTION: Russell-Silver syndrome (RSS) is a unique cause of syndromic, and often severe, limb length discrepancy (LLD). RSS causes growth retardation both in utero and postnatally, with asymmetry in limb length more noticeable as growth progresses throughout childhood and adolescent. We aim to present the largest cohort in the literature on limb lengthening in patients with RSS and to validate previous literature supporting faster bony consolidation in these patients with more robust data. We further aim to establish differences in healing within this cohort based on age, sex, segment lengthened, or type of lengthening procedure performed, to help refine patient expectations and guide practitioners in treating this population. METHODS: This was a retrospective study of patients with a diagnosis of RSS who underwent a limb lengthening procedure for the purpose of limb equalization. They were compared with a historic control group of patients who underwent limb lengthening for LLD of a non-RSS etiology. The primary outcome measure was bone healing index (BHI). RESULTS: The RSS group consisted of 24 patients with 29 segments lengthened, and was compared with a historic control group consisting of 20 patients with 22 segments lengthened (Goldman). Patients with RSS had a significantly lower BHI, and therefore faster healing of their lengthening site, than their non-RSS peers (P=0.02). Within the RSS cohort, we did not detect a difference in BHI based on intervention type or sex, but we did find a trend toward faster healing in femurs over tibiae (P=0.08), and established that younger patients tended toward lower BHIs (P<0.01). CONCLUSIONS: Our results confirmed with more robust data the prior finding that patients with RSS may undergo limb lengthening procedures at least as safely as their non-RSS counterparts, and with even faster bony consolidation, especially in younger patients. We hypothesize that concurrent treatment with growth hormone supplementation may contribute to this finding, although further study is necessary. This is the largest cohort of RSS patients treated with limb lengthening for LLD reported in the literature, and these findings will help to guide surgeon decision-making when treating this unique population. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

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.

Standardization of torsional CT measurements of the lower limbs with threshold values for corrective osteotomy.

INTRODUCTION: Re-establishing anatomic rotational alignment of shaft fractures of the lower extremities remains challenging. Clinical evaluation in combination with radiological measurements is important in pre- and post-surgical assessment. Based on computed tomography (CT), a range of reference values for femoral torsion (FT) and tibial torsion (TT) have historically been reported, which require standardization to optimize the significant intra- and inter-observer variability. The aims of this study were (re-)evaluation of the reference FT and TT angles, determination of the normal intra-individual side-to-side torsional differences to aid the surgical decision-making process for reoperation, and development of a novel 3D measurement method for FT. MATERIALS AND METHODS: In this retrospective study, we included 55 patients, without any known torsional deformities of the lower extremities. Two radiologists, independently, measured the rotational profile of the femora using the Hernandez and Weiner CT methods for FT, and the tibiae using the bimalleolar method for TT. The intra-individual side-to-side difference in paired femora and paired tibiae was determined. A 3D technique for FT assessment using InSpace® was designed. RESULTS: FT and TT demographic values were lower than previously reported, with mean FT values of 5.1°-8.8° and mean TT values of 25.5°-27.7°. Maximal side-to-side differences were 12°-13° for FT and 12° for TT. The Weiner method for FT was less variable than the Hernandez method. The new 3D method was equivocal to the conventional CT measurements. CONCLUSION: The results from this study showed that the maximal side-to-side tolerance in asymptomatic normal adult lower extremities is 12°-13° for FT and 12° for TT, which could be a useful threshold for surgeons as indication for revision surgery (e.g., derotational osteotomy). We developed a new 3D CT method for FT measurement which is similar to 2D and could be used in the future for virtual 3D planning.

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.

Does Integrated Fixation Provide Benefit in the Reconstruction of Posttraumatic Tibial Bone Defects?

BACKGROUND: Limb salvage in the presence of posttraumatic tibial bone loss can be accomplished using the traditional Ilizarov method of distraction osteogenesis with circular external fixation. Internal fixation placed at the beginning of the consolidation phase, so-called integrated fixation, may allow for earlier removal of the external fixator but introduces concerns about cross-contamination from the additional open procedure and maintenance of bone regenerate stability. QUESTIONS/PURPOSES: Among patients deemed eligible for integrated fixation, we sought to determine: (1) Does integrated fixation decrease the time in the external fixator? (2) Is there a difference in the rate of complications between the two groups? (3) Are there differences in functional and radiographic results between integrated fixation and the traditional Ilizarov approach of external fixation alone? METHODS: Between January 2006 and December 2012, we treated 58 patients (58 tibiae) with posttraumatic tibial bone loss using the Ilizarov method. Of those, 30 patients (52%) were treated with the "classic technique" (external fixator alone) and 28 (48%) were treated with the "integrated technique" (a combination of an external fixator and plating or insertion of an intramedullary nail). During that period, the general indications for use of the integrated technique were closed physes, no active infection, and a healed soft tissue envelope located at the intended internal fixation site; the remainder of the patients were treated with the classic technique. Followup on 30 (100%) and 28 (100%) patients in the classic and integrated techniques, respectively, was achieved at a minimum of 1 year (mean, 3 years; range, 1-8 years). Adverse events were reported as problems, obstacles, and complications according to the publication by Paley. Problems and obstacles are managed by nonoperative and operative means, respectively; in addition, they resolve completely with treatment. Complications, according to the Paley classification, result in permanent sequelae. Functional and radiographic results were reported using the Association for the Study and Application of Methods of Ilizarov scoring system. RESULTS: Overall, there was a mean of four (range, 2-5) surgical procedures to complete the tibial reconstruction with a similar incidence of unplanned surgical procedures (obstacles) between the two groups (p = 0.87). Patients treated with integrated fixation spent less time in the external fixator, 7 months (range, 5-20 months) versus 11 months (range, 1-15 months; p < 0.001). There were seven problems, 15 obstacles, and zero complications in the classic group. Ten problems, 15 obstacles, and one complication occurred in the integrated fixation group. There was no difference in the severity (p = 0.87) or number (p = 0.40) of complications between both groups. Good to excellent Association for the Study and Application of Methods of Ilizarov function and bone scores were obtained in 100% and 98% of patients, respectively. CONCLUSIONS: The integrated fixation method allows for a more efficient limb salvage surgical reconstruction in patients carefully selected for that approach, whereas the frequency of adverse events and ability to restore limb lengths was not different between the groups with the numbers available. Careful placement of external fixation pins is critical to decrease cross-contamination with planned internal fixation constructs. In this study of posttraumatic tibial bone defect reconstruction, good/excellent results were found in all patients after a mean of four surgical procedures; however, a larger multicenter prospective study would allow for more robust and generalizable conclusions. LEVEL OF EVIDENCE: Level III, therapeutic study.

What is the Utility Of a Limb Lengthening and Reconstruction Service in an Academic Department of Orthopaedic Surgery?

BACKGROUND: Limb lengthening and reconstruction surgery is a relatively new subspecialty of orthopaedic surgery in the United States. Despite increased awareness and practice of the specialty, it is rarely vested as a separate clinical service in an academic department of orthopaedic surgery. We have had experience growing such a dedicated service within an academic department of orthopaedic surgery over the past 9 years. QUESTIONS/PURPOSES: We explored (1) the use of a limb deformity service (LDS) in an academic department of orthopaedic surgery by examining data on referral patterns, our clinical volume, and academic productivity; and (2) the surgical breadth of cases comprising the patients of the LDS in an academic department of orthopaedic surgery by examining data on caseload by anatomic sites, category, and surgical techniques/tools. METHODS: We (SRR, ATF, EWB) retrospectively examined data on numbers of surgical cases and outpatient visits from the limb lengthening and complex reconstruction service at the Hospital for Special Surgery from 2005 to 2013 to evaluate growth. We studied 672 consecutive surgical cases performed by our service for a sample period of 1 year, assessing referral patterns within and outside our medical center, anatomic region, surgical category, and surgical technique/tool. Academic productivity was measured by review of our service's publications. RESULTS: During the time period studied (2005-2013), outpatient and surgical volume significantly increased by 120% (1530 to 3372) and 105% (346 to 708), respectively, on our LDS. Surgical volume growth was similar to the overall growth of the department of orthopaedic surgery. Referrals were primarily from orthopaedic surgeons (56%) and self/Internet research (25%). Physician referrals were predominantly from our own medical center (83%). Referrals from within our institution came from a variety of clinical services. Forty-nine peer-reviewed articles and 23 book chapters were published by staff members of our service. Anatomic surgical sites, surgical categories, and technique/tools used on our LDS were diverse, yet procedures were specialized to the discipline of limb deformity. CONCLUSIONS: There is a substantial role for an LDS within an academic department of orthopaedic surgery. With establishment of a dedicated service comes focus and resources that establish an environment for growth in volume, intramural and extramural referral, and purposeful research and education. The majority of referrals were from orthopaedic surgeons from our own medical center, suggesting needfulness. The LDS provides patients access to specialized surgery. The number of intramural referrals suggests that the specialty service helps retain patients within our academic orthopaedic department. Future research will try to determine if such a dedicated service leads to improved outcomes, efficiency, and value. LEVEL OF EVIDENCE: Level IV, retrospective study.

Precision of the PRECICE internal bone lengthening nail.

BACKGROUND: Previous designs of internal bone lengthening devices have been fraught with imprecise distraction, resulting in nerve injuries, joint contractures, nonunions, and other complications. Recently, a magnet-operated PRECICE nail (Ellipse Technologies, Inc, Irvine, CA, USA) was approved by the FDA; however, its clinical efficacy is unknown. QUESTIONS/PURPOSES: We evaluated this nail in terms of (1) accuracy and precision of distraction, (2) effects on bone alignment, (3) effects on adjacent-joint ROM, and (4) frequency of implant-related and non-implant-related complications. METHODS: We reviewed medical and radiographic records of 24 patients who underwent femoral and/or tibial lengthening procedures using the PRECICE nail from August 2012 to July 2013 for conditions of varied etiology, the most common being congenital limb length discrepancy, posttraumatic growth arrest, and fracture malunion. This group represented 29% of patients (24 of 82) who underwent a limb lengthening procedure for a similar diagnosis during the review period. At each postoperative visit, the accuracy and precision of distraction, bone alignment, joint ROM, and any complications were recorded by the senior surgeon (SRR). Accuracy reflected how close the measured lengthening was to the prescribed distraction at each postoperative visit, while precision reflected how close the repeated measurements were to each other over the course of total lengthening period. No patients were lost to followup. Minimum followup from surgery was 3 weeks (mean, 14 weeks; range, 3-29 weeks). RESULTS: Mean total lengthening was 35 mm (range, 14-65 mm), with an accuracy of 96% and precision of 86%. All patients achieved target lengthening with minimal unintentional effects on bone alignment. The knee and ankle ROM were minimally affected. Of the complications requiring return to the operating room for an additional surgical procedure, there was one (4%) implant failure caused by a nonfunctional distraction mechanism and six (24%) non-implant-related complications, including premature consolidation in one patient (4%), delayed bone healing in two (8%), delayed equinus contracture in two (8%), and toe clawing in one (4%). CONCLUSIONS: We conclude that this internal lengthening nail is a valid option to achieve accurate and precise limb lengthening to treat a variety of conditions with limb shortening or length discrepancy. Randomized, larger-sample, long-term studies are required to further confirm clinical efficacy of these devices, monitor for any late failures and complications, and compare with other internal lengthening devices with different mechanisms of operation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

What risk factors predict usage of gastrocsoleus recession during tibial lengthening?

BACKGROUND: Tibial lengthening is frequently associated with gastrocsoleus contracture and some patients are treated surgically. However, the risk factors associated with gastrocsoleus contracture severe enough to warrant surgery during tibial lengthening and the consistency with which gastrocsoleus recession (GSR) results in a plantigrade foot in this setting have not been well defined. QUESTIONS/PURPOSES: We compared patients treated with or without GSR during tibial lengthening with respect to (1) clinical risk factors triggering GSR use, (2) ROM gains and patient-reported outcomes, and (3) complications after GSR. METHODS: Between 2002 and 2011, 95 patients underwent tibial lengthenings excluding those associated with bone loss; 82 (83%) were available for a minimum followup of 1 year. According to our clinical algorithm, we performed GSR when patients had equinus contractures of greater than 10° while lengthening or greater than 0° before or after lengthening. Forty-one patients underwent GSR and 41 did not. Univariate analysis was performed to assess independent associations between surgical characteristics and likelihood of undergoing GSR. A multivariate regression model and receiver operating characteristic curves were generated to adjust for confounders and to establish risk factors and any threshold for undergoing GSR. Chart review determined ROM, patient-reported outcomes, and complications. RESULTS: Amount and percentage of lengthening, age, and etiology were risk factors for GSR. Patients with lengthening of greater than 42 mm (odds ratio [OR]: 4.13; 95% CI: 1.82, 9.40; p = 0.001), lengthening of greater than 13% of lengthening (OR: 3.88; 95% CI: 1.66, 9.11; p = 0.001), and congenital etiology (OR: 1.90; 95% CI: 0.86, 4.15; p = 0.109) were more likely to undergo GSR. Adjusting for all other variables, increased amount lengthened (adjusted OR: 1.05; 95% CI: 1.02, 1.07; p < 0.001) and age (adjusted OR: 1.02; 95% CI: 0.99, 1.05; p = 0.131) were associated with undergoing GSR. Patients gained 24° of ankle dorsiflexion after GSR. Self-reported functional outcomes were similar between patients with or without GSR. Complications included stretch injury to the posterior tibial nerve leading to temporary and partial loss of plantar sensation in two patients. CONCLUSIONS: Dorsiflexion was maintained and/or restored similarly among patients with or without GSR when treated under our algorithm. Functional compromise was not seen after GSR. Identification of patients at risk will help surgeons indicate patients for surgery. Acute dorsiflexion should be avoided to minimize risk of injury to the posterior tibial nerve. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Recombinant human BMP-2 increases the incidence and rate of healing in complex ankle arthrodesis.

BACKGROUND: Although its FDA-approved applications are limited, the pro-osteogenic benefits of recombinant human BMP-2 (rhBMP-2) administration have been shown in off-label surgical applications. However, the effects of rhBMP-2 on ankle fusions are insufficiently addressed in the literature, which fails to include a case-control study of adequate sample size to evaluate the efficacy of rhBMP-2 treatment. QUESTIONS/PURPOSES: In this study we asked whether rhBMP-2 treatment (1) would increase the rate of successful ankle fusion in complex patients (patients with comorbidities associated with poor surgical healing) compared with a control group of patients undergoing ankle fusion who did not receive rhBMP-2; (2) would reduce total time wearing a frame when compared with the control group; (3) would result in a difference in the percentage of bone bridging between the group treated with rhBMP-2 and the control group, as determined by CT scans 3 months after surgery; and (4) would encounter an equal rate of complications different from untreated patients. METHODS: A retrospective chart study was performed on 82 patients who, because of a host of comorbidities associated with poor healing, required a complex ankle arthrodesis with the Ilizarov technique. The first 40 patients did not receive rhBMP-2, whereas the subsequent 42 patients received intraoperative rhBMP-2. Time wearing the frame was determined by chart review; decision to remove the frame was made by the surgeon based on quantitative bone bridging measured using a CT scan taken 3 months after fusion. RESULTS: Patients treated with rhBMP-2 were more likely to obtain fusion after the initial surgery (93% versus 53%, p < 0.001; OR, 11.76; 95% CI, 3.12-44.41), spent less total time wearing the frame (124 versus 161 days, p < 0.01), and showed more bone bridging on CT scans (48% versus 32%, p < 0.05). All patients with greater than 30% bone bridging observed on CT scans 3 months postoperatively achieved successful union without further intervention. CONCLUSIONS: Our findings suggest that rhBMP-2 is a beneficial adjunct for selected groups of patients undergoing complex ankle arthrodesis. CT is a promising modality in the assessment of bone healing in ankle fusion. A proper randomized controlled trial remains necessary to fully describe the efficacy of rhBMP-2 in accelerating bone healing.

Knee arthrodesis as limb salvage for complex failures of total knee arthroplasty.

Patients with multiple failures of total knee arthroplasty (TKA) are challenging limb salvage cases. Twenty one patients over the last 10 years were referred to our service for knee fusion by arthroplasty surgeons who felt they were not candidates for revision TKA. Active infection was present in 76.2% and total bone loss averaged 6.6 cm. Lengthening was performed in 7/22 patients. Total time in Ilizarov frames was 9 months, with 93.3% union. Patients treated with IM fusion nails had 100% union. Average LLD increased from 3.6 to 4.5 cm following intervention, while those with concurrent lengthening improved to 1.6 cm. Findings suggest that bone loss and the soft-tissue envelope dictate knee fusion method, and multiple techniques may be needed. A treatment algorithm is presented.

Bone tumor reconstruction with the Ilizarov method.

BACKGROUND AND OBJECTIVES: Patients with musculoskeletal tumors can face large bone deficiency, deformity, and nonunion. Distraction osteogenesis via the Ilizarov method may be useful for reconstruction of these deficiencies allowing limb preservation and optimizing function. METHODS: We reviewed 20 patients with a range of musculoskeletal tumors necessitating surgical treatment. The group included 9 females and 11 males with a mean age of 22.6 (8-58) years at a mean follow up of 81.7 (26-131) months. The mean bone deficiency was 7.9 (1.2-18.0) cm. RESULTS: The mean lengthening achieved was 7.1 (3.5-18.0) cm over an EFI of 33.5 (range, 9.5-58.3) days/cm. This treatment resulted in 10 excellent and 3 good ASAMI bone scores, 10 excellent and 3 good ASAMI function scores, a mean lower extremity MSTS score of 93% and a mean upper extremity MSTS score of 87%. Treatment resulted in 2 complications, 18 obstacles, and 6 problems. CONCLUSION: The Ilizarov method is an effective technique for limb reconstruction of bone tumors, although extended time in external fixation is required. Since no one in this group received simultaneous chemotherapy or radiotherapy, we cannot comment on use of the Ilizarov method with these treatments. Further use and clinical follow-up is warranted.

Does humeral lengthening with a monolateral frame improve function?

BACKGROUND: Humeral lengthening by distraction osteogenesis historically has relied on bulky circular external fixators. Advances in fixator technology have allowed for the use of monolateral frames. However, it is unclear whether and to what degree function is improved after humeral lengthening. QUESTIONS/PURPOSES: We asked: (1) Does humeral lengthening performed with monolateral fixators improve function? (2) Does monolateral external fixation produce comparable restoration of length and complication rate when compared with historical results, using circular external fixation for humeral lengthening? METHODS: We retrospectively reviewed 11 patients who underwent 15 humeral lengthenings with monolateral external fixation. Clinical and radiographic data were collected, including preoperative and postoperative DASH scores as a metric of functional status. The minimum postremoval followup was 14 months (average, 38 months; range, 14-84 months). RESULTS: Fifteen humeri were lengthened an average of 7 cm (range, 4-9 cm), for a mean lengthening of 41% (range, 23%-52%). Lengthening required an average of 7 months (range, 5-8 months) of fixation, resulting in an external fixation index of 32 days/cm (range, 23-45 days/cm). The major complication rate (three of 15) and postoperative ROM (unchanged at the elbow and improved in seven of 15 shoulders) were comparable to those in previous studies using circular frames. In nine of 15 humeri for which DASH scores were available, the mean preoperative score improved from 14 to 9 after 1 year. The monolateral frame allowed the patient to keep their arm by the side without abducting the shoulder and without impinging the device into the chest wall. CONCLUSIONS: Humeral lengthening with monolateral external fixation is well tolerated by patients and an effective means of improving patient function with a complication rate similar to that for traditional circular frames.

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.

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.

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.