A systematic review and meta-analysis:comparing the efficacy of the Ilizarov technique alone with lengthening over a nail for lower extremity bone defects.

PURPOSE: The task faced by surgeons becomes significantly more challenging when they encounter lower extremity bone defects due to a variety of causes requiring lengthening. The most discussed and successful approach is the Illizarov technique, or lengthening over a nail (LON):distraction osteogenesis is also widely performed with monoliteral external fixators and intramedullarylengthening nails have increasingly been used in the last decade. METHODS: The data were collected from PubMed, Cochrane Library, Embase, and the Web of Science for all available studies comparing the outcomes of Ilizarov technique alone and LON technique (from January 1, 1997, to November 30, 2023). The outcomes of interest encompassed the external fixation index (EFI) (month/cm), mean duration of follow-up (MFT) (month), length gained (LG) (cm), consolidation index (CIx) (month/cm), and bone healing index (BHI) (month/cm).Complications include pin tract infection rate (PTI), axial deviation rate (AD), occurrence of intramedullary infection (II), delayed consolidation rate (DC), as well as data categorized into three levels of problems, obstacles, and sequelae based on the severity of complications.Two reviewers independently assessed each study for quality and extracted data. The case-control or respective cohort studies were evaluated using the Newcastle-Ottawa scale (NOS) to determine their techniqueological rigor.The Cochrane Collaboration's risk assessment tool was employed to perform quality evaluations for randomized controlled trials. RESULTS: This review included thirteen studies comprising a total of 629 patients.The external fixation index (month/cm) was significantly smaller in the LON technique compared to the Ilizarov technique alone [Mean Difference(MD) = -29.59, 95% CI -39.68--19.49, P < 0.00001].In terms of the mean follow-up time(month) (MD = -0.92, 95% CI -3.49-1.65, P = 0.57), length gained (cm) (MD = -0.87, 95%CI -2.80-1.07, P = 0.38), consolidation index (month/cm) (MD = 0.66, 95% CI -3.44-4.77, P = 0.75), and bone healing index (month/cm) (MD = -3.33, 95% CI -13.07-6.41, P = 0.5), there were no significant differences observed. The LON technique exhibited a lower incidence of axial deviation [Odds Ratio(OR) = 0.06, 95%CI 0.03-0.16, P < 0.00001] and pin tract infection (OR = 0.30, 95%CI 0.18-0.50, P < 0.00001) compared to the Ilizarov technique alone.The remaining complications, such as intramedullary infection rate (OR = 0.93, 95%CI 0.42-2.06, P = 0.85) and delayed consolidation rate(OR = 0.61, 95%CI 0.20-1.86, P = 0.38), did not exhibit statistically significant differences.Our findings demonstrated that the LON technique results in lower incidences of problems (38.5%vs.58.6%) and sequelae (16.6% vs.30.9%) when compared to the Ilizarov technique alone. However, the rates of obstacles (32.4% vs.32.3%) were comparable between the two methods. CONCLUSIONS: Our findings indicate that patients treated with the LON technique experienced significantly shorter external fixation durations and a lower incidence of complications (e.g., pin tract infections and axial deviation) compared to those treated with the Ilizarov technique alone. Other outcome metrics showed no significant differences between the two techniques. However, the LON technique offers substantial benefits, including reduced external fixation times and increased comfort, which enhance patient compliance. In conclusion, the LON technique is a safe, reliable, and effective method for treating tibial and femoral defects.

Screw Configuration Does Not Significantly Alter Neck Shortening After Valgus-Impacted Femoral Neck Fracture (OTA Type 31B1.1).

OBJECTIVES: To compare 3 different cancellous screw configurations used for Garden 1 femoral neck fractures (FNFs). DESIGN: Retrospective review. SETTING: A large urban academic medical center. PATIENT SELECTION CRITERIA: All patients with Orthopaedic Trauma Association 31B1.1 FNF who underwent in situ fixation with cancellous screws between 2012 and 2021 were included. Patients were divided into 3 groups: 2 screws placed in a parallel fashion, 3 screws placed in an inverted triangle configuration, and 3-screw fixation with placement of 1 "out-of-plane" screw perpendicular to the long axis of the femur. OUTCOME MEASURES AND COMPARISONS: Postoperative femoral neck shortening (mm) was the primary outcome, which was compared among the 3 groups of different screw configurations. RESULTS: Sixty-one patients with a median follow-up of 1 year (interquartile range 0.6-1.8 years) and an average age of 72 years (interquartile range 65.0-83.0 years) were included. All fractures demonstrated bony healing. Overall, 68.9% of the cohort had ≤2 mm of femoral neck shortening. There was no difference between groups in the proportion of patients who experienced greater than 2 mm of shortening (P = 0.839) or in the amount (mm) of femoral neck shortening (Kruskal-Wallis χ2 = 0.517, P = 0.772). CONCLUSIONS: Although most patients with valgus-impacted FNF treated with screw fixation do not experience further femoral neck shortening, some patients demonstrated continued radiographic shortening during the healing process. The development of further femoral neck shortening and the amount of shortening that occurs do not differ based on implant configuration. Multiple different screw configurations seem to be acceptable for achieving healing and minimizing further femoral neck impaction. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Femoral Lengthening in Children with Congenital Femoral Deficiency: A Systematic Review.

BACKGROUND: Congenital femoral deficiency (CFD) presents a significant challenge in pediatric orthopaedics, characterized by a spectrum of congenital anomalies ranging from mild femoral shortening to complete absence of the proximal femur and hip joint. This review aims at reviewing the latest concepts of femoral limb lengthening modalities in treating CFD, to explore the efficacy, complications, and long-term outcomes of various surgical techniques. METHODS: A comprehensive search of the literature was performed for clinical studies involving lengthening in patients with proximal focal femoral deficiency (PFFD) in several databases. RESULTS: We analyze the evolution of limb lengthening procedures, from the Wagner and Ilizarov methods to the latest advancements in distraction osteogenesis, and assess their role in addressing the functional needs of patients. We also analyze the possible risk factors for the occurrence of complications with each method and alternatives to avoid them. CONCLUSION: The review highlights the importance of individualized treatment plans, considering factors such as the degree of femoral deficiency and the potential for achieving a functional limb length; however, it requires a multidisciplinary approach and careful preoperative planning to optimize patient outcomes. The review underlines the need for ongoing research to refine surgical techniques and to compare them and improve the quality of life for individuals with PFFD. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.

Correction of Acquired Leg Length Discrepancy after Hip Resurfacing Arthroplasty by Revision Resurfacing: A Case Report.

CASE: A 53-year-old man presented with a 13-mm leg length discrepancy following left hip resurfacing arthroplasty (HRA), resulting in pain and imbalance. Advanced osteoarthritis of the contralateral hip was also noted. The patient strongly preferred HRA over total hip arthroplasty. Adequate remaining bone stock and the ability to resurface the contralateral hip allowed for resolution with 2 HRAs. CONCLUSION: This is the first known revision of a HRA with a subsequent HRA. Assuming sufficient bone stock and precise implant positioning, resurfacing presents a feasible methodology to overcome complex anatomical deformities and improve mobility.

Advancing pediatric bone sarcoma care: navigating complications and innovating solutions in limb salvage and reconstruction-why, when, and how to treat limb length inequalities.

Pediatric bone sarcomas, particularly osteosarcomas, present unique challenges in the realm of orthopedic oncology, given their predilection for the metaphyseal regions of long bones and the intricate balance required between achieving oncologic control and preserving limb function. This abstract encapsulates findings from a comprehensive review aimed at advancing pediatric bone sarcoma care, focusing on navigating the complications and innovating solutions for complications of limb salvage and reconstruction focusing on limb length inequalities and accompanying bone defects. Advancements in imaging, surgical techniques, and adjuvant therapies have shifted the paradigm from amputation to limb-sparing surgeries, albeit with significant challenges, especially in young patients where growth potential complicates reconstructive outcomes. The series highlights the complexity of managing limb length discrepancies (LLD), the cornerstone of limb salvage challenges, and the innovative approaches to address them, including modular endoprosthetic reconstruction with expandable prostheses, magnetic lengthening nails and biological reconstruction strategies like vascularized fibula grafts. This review underlines the importance of a multidisciplinary approach in managing pediatric bone sarcomas, where the aim extends beyond mere survival to ensuring quality of life through functional limb preservation. It highlights the need for ongoing innovation in surgical and reconstructive techniques tailored to the pediatric population's unique needs, emphasizing the potential of emerging technologies and methodologies to improve outcomes. Future research should aim to fill the existing knowledge gaps, particularly in comparing pediatric and adult surgical outcomes, to refine treatment protocols and improve patient care in this challenging domain.

Lower extremity length discrepancy solution by modified drilling epiphysiodesis and anthropological prediction methods: long-term results.

This study aimed to summarize our experience with modified drilling epiphysiodesis and prediction methods for accurate timing of surgery and to compare the results with those of recent work by other authors. The Macnicol and Gupta modified drilling technique was used. Distal femoral and/or proximal tibial permanent epiphysiodesis was performed in 42 children (21 boys, 21 girls; median age at surgery=12.6 years, age range=9.4-15.4 years) between 2004 and 2016. Based on the groundwork of previous studies, we developed an auxological prediction method. The limb length discrepancy (LLD) was assessed by clinical examination and verified by an x-ray of the hips when standing with blocks under the shorter leg. The predicted shortening was 2.7 cm ± 1.1 cm. The final discrepancy after finishing skeletal growth was 0.5 ± 0.5 cm. In 26 patients (61.9%), equalization of both legs was achieved (0-0.5 cm). In 4 patients (9.5%), the remaining shortening was more than 1.0 cm. Shortening of an initially longer leg occurred in two patients (0.5 cm and 0.6 cm). Failure of growth plate arrest was observed in 1 patient. In another 3 patients, the efficacy of tibial epiphysiodesis was unsatisfactory. Minor complications occurred in 5 cases, but there was no evidence of angular deformity in the frontal and sagittal planes or proximal fibula overgrowth. Three patients (7.1%) returned to the operating room. Compared to published data, more patients achieved complete equalization of leg length. The results of this study verified the accuracy of the auxological prediction algorithm of LLD based on Shapiro's findings. The surgical outcome is comparable between Shapiro patterns 1 and 3. Auxological examination, assessment of bone age, and sexual maturation are crucial tools for accurate timing of surgery.

Simultaneous correction of leg length discrepancy and angular deformity of the distal femur with retrograde Precice nails: a retrospective analysis of 45 patients.

BACKGROUND AND PURPOSE: Magnetically controlled motorized intramedullary lengthening nails (ILNs) can be employed for simultaneous correction of angular deformities of the distal femur and leg length discrepancy. This spares typical complications of external fixators but requires precise preoperative planning and exact intraoperative execution. To date, its results are insufficiently reported. We aimed to elucidate the following questions: (i) Is acute angular deformity correction and gradual femoral lengthening via a retrograde ILN a reliable and precise treatment option? (ii) What are the most common complications of treatment? METHODS: Acute angular deformity correction and subsequent gradual lengthening of the distal femur with retrograde ILN was retrospectively analyzed in 45 patients (median patient age: 15 years, interquartile range [IQR] 13-19 and median follow-up: 40 months, IQR 31-50). Outcome parameters were accuracy, precision, reliability, bone healing, and complications of treatment. RESULTS: The median distraction was 46 mm (IQR 29-49), median distraction and consolidation index 0.9 mm/day (IQR 0.7-1.0) and 29 days/cm (IQR 24-43), respectively. The median preoperative mechanical axis deviation (MAD) was 30 mm (IQR 23-39) in the varus cohort and -25 mm (IQR -29 to -15) in the valgus cohort and reduced to a mean of 8 mm (standard deviation [SD] 8) and -3 (SD 10), respectively. Accuracy, precision, and reliability of lengthening were 94%, 95% and 96%, respectively. Accuracy and precision of deformity correction were 92% and 89%, respectively. In total, 40/45 of patients achieved distraction with a difference of less than 1 cm from the initial plan and a postoperative MAD ranging from -10 mm to +15 mm. In 13/45 patients unplanned additional surgeries were conducted to achieve treatment goal with nonunion being the most frequent (4/45) and knee subluxation (3/45) the most severe complication. CONCLUSION: Acute deformity correction and subsequent lengthening of the distal femur with retrograde ILN is a reliable and accurate treatment achieving treatment goal in 89% but unplanned additional surgeries in 29% of patients should be anticipated.

Staples, tension-band plates, and percutaneous epiphysiodesis screws used for leg-length discrepancy treatment: a systematic review and proportional meta-analysis.

BACKGROUND AND PURPOSE: The primary aim of this systematic review and meta-analysis was to evaluate the success rate of 3 different epiphysiodesis techniques with implant usage for the treatment of leg-length discrepancy (LLD) in the pediatric population. The secondary aim was to address effectiveness (final LLD) and the reported complications of staples, tension-band plates (TBP), and percutaneous epiphysiodesis screws (PETS). METHODS: In this systematic review we searched MEDLINE (PubMed), Embase, Cochrane Library, Web of Science and Scopus for studies on skeletally immature patients with LLD treated with epiphysiodesis with an implant. The extracted outcome categories were effectiveness of epiphysiodesis (LLD measurements pre-/postoperatively, successful/unsuccessful) and complications that were graded on severity. RESULTS: 44 studies (2,184 patients) were included. 455 underwent epiphysiodesis with PETS, 578 patients with TBP, and 1,048 with staples. Successful epiphysiodesis was reported in 76% (95% confidence interval [CI] 61-89) with PETS (9 studies), 67% (CI 54-79) with TBP (10 studies), and 51% (CI 28-65) with Blount staples (8 studies). From pooled analysis, the severe complications rate was 7% for PETS, 17% for TBP, and 16% for Blount staples. Angular deformity was reported in 4% after PETS, 10% after TBP, and 17% after Blount staples. CONCLUSION: Our results showed that epiphysiodesis with PETS implants was the most successful technique. PETS had a higher success rate, fewer severe complications, and a lower proportion with angular deformity.

Management of a Proximal Femoral Central Physeal Bar in a 3-Year-Old Child Using a Novel Surgical Technique: A Case Report.

CASE: We present a proximal femoral central physeal bar secondary to femoral neck fracture management, in a 3-year-old boy. He presented with progressive femoral neck deformity and limb length discrepancy. He was managed with a novel technique of bar resection by drilling and polymethylmethacrylate interposition. After 5 years of follow-up, the hip score by Ratliff criteria was good. CONCLUSION: Screw penetration across physis during management of femoral neck fracture can cause growth arrest in a young child. Our technique is useful when physeal bar is central and linear. It can allow sufficient growth and remodeling to restore a near-normal hip both radiologically and clinically.

Comparison of limb reconstruction with vascularized fibula flap versus induced membrane technique in 54 pediatric cases over 16 years.

BACKGROUND: Children's bone loss of limbs represents a significant challenge for surgeons, especially given that children are growing individuals. In the pediatric population, we compared bone reconstruction using vascularized fibula flaps with the induced membrane technique. The primary purpose of this study was to evaluate the delay and quality of consolidation. METHODS: Data from patients who underwent limb reconstruction using either the fibula flap or the induced membrane were retrospectively collected from files across two centers. Perioperative and long-term complications were documented, along with functional and aesthetic outcome. RESULTS: Between 2004 and 2020, 31 children underwent limb reconstruction using a fibula flap, and 13 patients were treated using the induced membrane technique. The etiologies included 76% tumors, 20% congenital pseudarthroses, and 3.7% infections. The median size of the bone resection was 12.5 cm (range: 1.8 to 31 cm). The median time to consolidation after free fibula flap transfer was 10 months (range: 2 to 55 months) versus 7.5 months (range: 1 to 64 months) for the Masquelet technique (p = 0.54). Limb length inequality occurred in 52% of fibula cases and 39% of the induced membrane cases (p = 0.55). CONCLUSIONS: Both of free fibula flap and the induced membrane technique are effective options for bone reconstructing long bones in children. These techniques yield good functional outcomes and have comparable consolidation times.

Total Hip Arthroplasty Combined with Proximal Femoral Reconstruction Effectively Treats Severe Hip Deformities: A Novel Osteotomy Technique.

OBJECTIVE: Total hip arthroplasty (THA) combined with proximal femoral reconstruction is a novel osteotomy technique developed to address severe hip deformities. There is a paucity of robust clinical and radiological evidence regarding the outcomes of this novel osteotomy technique. This study aimed to evaluate the clinical and radiological outcomes of THA combined with proximal femoral reconstruction during the early follow-up. METHODS: This is a retrospective case series of 63 hips who underwent THA combined with proximal femoral reconstruction at a single institution between January 2020 and July 2023. The mean age of patients was 39.6 ± 12.6 years. The mean follow-up was 25.6 ± 3.8 months. Surgical characteristics and perioperative variables were evaluated to assess the efficacy of this technique. Harris hip score (HHS) was utilized to evaluate hip function. Leg length discrepancy (LLD) was evaluated in X-ray. The incidence of major adverse events including deep vein thrombosis (DVT), osteolysis, nonunion of the osteotomy, intraoperative femoral fracture, and infection was also evaluated. Paired-samples t-test was used to compare preoperative and postoperative HHS and LLD. RESULTS: The mean operative time was 125.1 min. The mean size of the acetabular components used was 45.2 mm, and the stem size was 7.5. The primary friction interface was ceramic-on-ceramic, accounting for 92.1% of cases. The average length of hospital stay was 8.5 days. The mean cost of treatment was 46,296.0 Yuan. There was a significant improvement in postoperative HHS (p < 0.001) and LLD (p < 0.001) compared to preoperative values. The incidence of deep venous thrombosis was 4.8%; osteolysis rates for the cup and stem were 4.8% and 6.4%, respectively. The non-union and dislocation rates were 1.6% and 3.2%, respectively. There was no incidence of postoperative infection. CONCLUSION: The novel osteotomy surgical procedure yields reliable and impressive clinical and radiological outcomes, with minimal complications. We advocate for its use in complex primary THA cases involving severe proximal femoral deformities.

Radiographic evaluation of robot-assisted versus manual total hip arthroplasty: a multicenter randomized controlled trial.

BACKGROUND: The effectiveness of robot-assisted surgery remains contentious due to the lack of high-quality randomized controlled trials (RCTs) to elevate the level of evidence. We aimed to evaluate the postoperative radiographic outcomes of robot-assisted (RAS-THA) versus manual (M-THA) total hip arthroplasty. METHODS: This multicenter RCT was performed from March 1, 2021 to December 1, 2021. Patients were randomly assigned to routine M-THA or to RAS-THA that used the TRex-RS orthopedic joint surgical navigation system. The primary outcome was to compare the acetabular component orientation, femoral stem alignment, femoral canal fill ratio, and leg length discrepancy between RAS-THA and M-THA using postoperative radiography. Subgroup analyses of the two groups stratified by surgical approach, gender, and BMI were also conducted. RESULTS: Seventy-three participants were randomly allocated to the RAS-THA group, while seventy-two participants were assigned to the M-THA group. Compared to the M-THA group, the RAS-THA group exhibited less variability in the preoperative planning of the vertical center of rotation (VCOR; P < 0.001), demonstrated a significant advantage in femoral stem alignment (P = 0.004), and showed pronounced decreases in inequality and in the variability in leg length discrepancy (P < 0.001). There was no significant difference in the Lewinnek safe-zone ratio (P = 0.081) and the femoral canal fill ratio (P > 0.05) between the two groups. Further subgroup analysis also showed that the RAS-THA group had fewer horizontal center of rotation (HCOR) and leg length differences when stratified by surgical approach, gender, and overweight status. CONCLUSION: This RCT found that, regardless of the surgical approach, gender, or body mass index, RAS-THA can effectively improve the postoperative VCOR and significantly reduce the variability of leg length difference. RAS-THA should be considered an effective method to enhance surgical precision by achieving less variability in challenging patients with leg length discrepancies. TRIAL REGISTRATION: ChiCTR2100044124.

Characterizing the Magnitude and Risk Factors of Functional and Anatomic Limb Lengthening in Patients Undergoing Revision Total Knee Arthroplasty.

BACKGROUND: In revision total knee arthroplasty (TKA), there is little information on the magnitude of potential limb lengthening, risk factors for lengthening, or its impact on patient-reported outcome measures. We aimed to quantify limb length alteration during revision TKA and assess risk factors for lengthening. METHODS: We identified 150 patients over a 3-year period who underwent revision TKA and had preoperative and postoperative EOS hip-to-ankle standing radiographs. The average patient age was 64 years, 51% were women; 68% had a preoperative varus deformity and 21% had a preoperative valgus deformity. Outcomes assessed included change in functional and anatomic limb length, risk factors for lengthening, and clinical outcome scores, including the Knee Osteoarthritis Outcome Score Joint Replacement, and the Veterans RAND 12-item Physical and Mental Scores. RESULTS: There were 124 patients (83%) who had functional limb lengthening, and 108 patients (72%) had anatomic limb lengthening. Patients had an average functional limb lengthening of 7 mm (range, -22 to 35) and an average anatomic limb lengthening of 5 mm (range, -16 to 31). Patients undergoing revision for instability experienced significantly greater anatomic lengthening (7.6 versus 4.6, P = .047). Patients who had ≥ 10° of deformity were more likely to be functionally lengthened (91 versus 79%) and had significantly greater average functional lengthening (12 versus 6 mm; P = .003). There was no significant change in clinical outcome scores at 6 weeks and 1 year for patients lengthened ≥ 5 or 10 mm compared to those not lengthened as substantially. CONCLUSIONS: There is major potential for functional and anatomic limb lengthening following revision TKA, with greater preoperative deformity and revision for instability being risk factors for lengthening.

Total Hip Arthroplasty in Patients Who Have Crowe Type IV Developmental Dysplasia of the Hip: A Systematic Review.

BACKGROUND: Developmental dysplasia of the hip (DDH) is one of the principal causes of secondary hip osteoarthritis, giving rise to considerable pain, impaired mobility, and a reduced quality of life. The optimal approach to managing individuals who have Crowe type IV DDH remains controversial. This study aimed to review the existing literature on the application of total hip arthroplasty (THA) as a treatment modality for Crowe type IV DDH, assessing its efficacy in addressing this severe hip deformity. METHODS: A comprehensive search across the PubMed, Scopus, and Web of Science databases identified relevant studies. Inclusion criteria encompassed investigations reporting outcomes of THA in Crowe type IV DDH patients. Data extraction and quality assessment were performed independently by 2 reviewers. Utilizing R software, the prevalence of THA complications was analyzed through proportion analysis, employing the inverse variance method. RESULTS: In this systematic review, a total of 74 studies were included, comprising a collective sample size of 2,829 patients (3,356 hips) diagnosed with Crowe type IV DDH. The posterior or posterolateral approach was the most commonly utilized surgical approach, followed by the lateral Hardinge and direct lateral approaches. The majority of studies have employed subtrochanteric osteotomies. Notably, post-THA, leg length discrepancy decreased, Trendelenburg sign resolved, and back pain was reduced. Patient-reported outcome measures like the Harris Hip Score improved significantly. The pooled prevalence rates of major postoperative complications were also assessed, including dislocation (7.2%), revision (8.7%), intraoperative fractures (10.5%), loosening (5.7%), nerve paralysis (5.6%), deep vein thrombosis (3.6%), infection (3.8%), heterotopic ossification grade 2 and above (6.1%), and a complicated patient rate of 11.0%. CONCLUSIONS: Synthesizing diverse study data, an overview of THAs performance emerges, demonstrating significant enhancements in function, pain reduction, quality of life, and the correction of substantial leg length discrepancy. While THA has shown positive outcomes, instances of complications have been reported. The decision to undergo THA should involve a collaborative assessment between the surgeon and the patient, considering potential benefits and complications.

Cementless Total Hip Arthroplasty With Paavilainen Femoral Shortening Osteotomy Can Provide Good Results at 10 Years in Patients Who Have Crowe IV Developmental Dysplasia of the Hip.

BACKGROUND: The aim of this study was to present the clinical and radiologic results of primary total hip arthroplasty (THA) using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV developmental dysplasia of the hip. METHODS: We retrospectively analyzed the results of primary THA using the Paavilainen technique in 335 hips. The mean follow-up was 10.2 years. The degree of limp, leg-length discrepancy, and patient satisfaction were assessed. The Oxford Hip Score was used to examine functional outcomes. A number of radiographic parameters were also assessed. RESULTS: The most common reason for revision surgery was nonunion of the distally advanced greater trochanter. This complication was observed in 22 hips (6.5%). The 10-year survival for acetabular components, it was 97.3%, and for femoral components was 98.7% with aseptic loosening as the end point, and 85.9% with reoperation for any reason as the end point. Patients demonstrated improved functional outcomes. The mean limb lengthening was 27.8 mm. Nonunion was more common if the contact length of the proximal femoral fragment with the lateral surface of the distal femoral fragment was less than 35 mm. CONCLUSIONS: Cementless primary THA using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV dysplasia of the hip demonstrates good clinical and radiologic postoperative results. If the contact between the fragments after osteotomy is less than 35 mm, there is a high risk of nonunion, and supplemental fixation may be warranted.

Lengthening in congenital posteromedial bowing of tibia: a follow-up series at skeletal maturity.

PURPOSE: Congenital posteromedial bowing (CPMB) of tibia is a rare, usually self-resolving condition that is present at birth. The data on the long-term outcome of lengthening, choice of fixator, outcome in early and late age groups, and complications is sparse, hence the need for this study. METHODS: This retrospective study included 93 patients with 94 affected legs from 1991 to 2023. The patients were categorized into early (under 10 years) and late (10 years or above) intervention groups. Eighteen patients with nineteen lengthening episodes who attained skeletal maturity made the basis of this study and will be discussed in detail. RESULTS: The outcome for the lengthening group at maturity was satisfactory, with 5.53 cm of average length gained per lengthening episode, a mean LLD of 0.31 cm at final follow-up, a mean age of 23.63 years (range 14-38 years), and an average follow-up of 12.51 years (range 3-28 years) post-lengthening, but the procedure was associated with difficulties like ankle stiffness, tibial valgus, pin tract infections, and fractures through regenerate. CONCLUSION: This study represents a large single-centre series on CPMB. We recommend that surgery for lengthening should be done at an older age, close to skeletal maturity, wherever possible to reduce the risk of repeat lengthening procedures. Based on our experience, we recommend the use of a circular fixator. Uniplanar distractors should have an adequate number and spread of Schanz screws in each segment to reduce the risk of valgus malalignment of distracting segments of bone.

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.

Microwave Ablation of the Pig Growth Plate: Proof of Concept for Minimally Invasive Epiphysiodesis.

BACKGROUND: Different surgical methods for epiphysiodesis of limb length discrepancy (LLD) have been described. Although these methods are variably effective, they are associated with morbidity (pain and limp) and potential complications. Microwave ablation is a less-invasive opportunity to halt growth by selectively destroying the growth plate via thermal energy to treat LLD in children. QUESTIONS/PURPOSES: In this proof-of-concept study using an in vivo pig model, we asked: (1) What is the durability of response 2 to 4 months after microwave ablation of the tibial growth plate as measured by length and angulation of the tibia via a CT scan? (2) Was articular cartilage maintained as measured by standard histologic staining for articular cartilage viability? METHODS: To develop an in vivo protocol for microwave ablation, we placed microwave antennas adjacent to the proximal tibia growth plate in the cadaveric hindlimbs of 18 3-month-old pigs. To determine the suitable time, we varied ablation from 90 to 270 seconds at 65-W power settings. After sectioning the tibia, we visually assessed for discoloration (implying growth plate destruction) that included the central growth plate but did not encroach into the epiphysis in a manner that could disrupt the articular surface. Using this information, we then performed microwave ablation on three live female pigs (3.5 to 4 months old) to evaluate physiologic changes and durability of response. A postprocedure MRI was performed to ensure the intervention led to spatial growth plate alterations similar to that seen in cadavers. This was followed by serial CT, which was used to assess the potential effect on local bone and growth until the animals were euthanized 2 to 4 months after the procedure. We analyzed LLD, angular deformity, and bony deformity using CT scans of both tibias. The visibility of articular cartilage was compared with that of the contralateral tibia via standard histologic staining, and growth rates of the proximal tibial growth plate were compared via fluorochrome labeling. RESULTS: Eighteen cadaveric specimens showed ablation zones across the growth plate without visual damage to the articular surface. The three live pigs did not exhibit changes in gait or require notable pain medication after the procedure. Each animal demonstrated growth plate destruction, expected limb shortening (0.8, 1.2, and 1.5 cm), and bony cavitation around the growth plate. Slight valgus bone angulation (4º, 5º, and 12º) compared with the control tibia was noted. No qualitatively observable articular cartilage damage was encountered from the histologic comparison with the contralateral tibia for articular cartilage thickness and cellular morphology. CONCLUSION: A microwave antenna placed into a pig's proximal tibia growth plate can slow the growth of the tibia without apparent pain and alteration of gait and function. CLINICAL RELEVANCE: Further investigation and refinement of our animal model is ongoing and includes shorter ablation times and comparison of dynamic ablation (moving the antennae during the ablation) as well as static ablation of the tibia from a medial and lateral portal. These refinements and planned comparison with standard mechanical growth arrest in our pig model may lead to a similar approach to ablate growth plates in children with LLD.

Limb Length Discrepancy After Intraosseous Line Malpositioning: A Case Report.

CASE: We will present the case of a 6-year-old girl who presented with a 3-cm limb length discrepancy after intraosseous line placement at age 14 months without other known history of trauma or infection to account for the growth arrest. Imaging revealed a left proximal tibial physeal bar amenable to surgical resection with autologous lipotransfer. At 10 months postoperatively, physical examination and imaging demonstrated a stable 3-cm leg length discrepancy with an interval increase in the length of the left tibia in proportion to the growth of the right side with an increase in valgus alignment that will continue to be monitored and addressed as indicated. CONCLUSION: Pediatric intraosseous line placement presents unique challenges and can ultimately lead to physeal injury and growth arrest in the case of malpositioning.