Chronic knee pain following infrapatellar/suprapatellar magnetic intramedullary lengthening nails versus external fixators in limb length discrepancy: A retrospective review.

Aims & objectives: Prior to the popularization of magnetic intramedullary nails (MILNs), gradual deformity correction using external fixation was the norm in limb lengthening. Trauma literature has shown MILN via a suprapatellar approach (SP) to be associated with less knee pain than either an infrapatellar entry (IP) or external fixation. Yet, no research has investigated chronic knee pain and MILNs. We assessed differences in chronic knee pain following lengthening via an IP or SP approach with an MILN versus external fixation. Materials & methods: We reviewed 147 limbs (55 MILN/IP, 22 MILN/SP, 71 external fixator) in 124 patients who underwent tibial lengthening with ≥12 months follow-up between February 2012 and July 2020. Knee pain was assessed pre- and postoperatively at 6 and 12 months, with the Lysholm Knee Scoring Scale (LKSS) and numeric pain scale (0-10). Differences in knee pain outcomes were compared across methods, with subgroup analysis of MILN/SP and MILN/IP. Results: Mean LKSS was 96.3 for external fixation and 88.5 for MILN (P = .011). In the MILN subgroups, mean LKSS was 91.7 for IP and 85.3 for SP. The IP group reported a lesser mean pain score (0.6 versus 2.1) at 12 months. Bilateral nail recipients demonstrated no knee pain differences versus unilateral. At 12 months postoperative, external fixation had better knee outcomes. Conclusion: Tibial lengthening with external fixation was associated with less chronic anterior knee pain and better functional outcomes than MILN overall. In terms of MILN approach, IP surpassed SP on subjective pain scores. Larger tibial lengthening and knee pain studies are warranted.

Staged Approach to Tibial Nail Removal Poses Increased Risk for Infection in the Setting of Total Knee Arthroplasty.

BACKGROUND: While previous research has addressed conversion arthroplasty scenarios, there is limited data on outcomes of staged or concurrent removal of intramedullary (IM) nails during total knee arthroplasty (TKA). Our study aimed to explore the association between the timing of IM nail removal and the incidence of periprosthetic joint infection (PJI), surgical site infection (SSI), manipulation under anesthesia (MUA), and aseptic revision at 90 days, 1 year, and 2 years after TKA when IM nail removal is performed in either a (1) staged or (2) concurrent manner. METHODS: We queried a national, all-payer database of all patients who underwent a primary TKA and hardware removal of an IM tibial nail. The group was separated into mutually exclusive cohorts with removal performed either (1) in a staged manner (n = 287) or (2) on the same day of TKA (n = 2,958). Surgical complications included the following: PJIs, SSIs, MUAs, and aseptic revisions. Surgical complications were collected at 90-day, 1 year, and 2-year time points. RESULTS: Patients who had staged nail removal before TKA demonstrated the highest incidence of PJI at 90 days, 1 year, and 2 years (13.9, 16.7, and 17.1%, respectively). Adjusted multivariate regression analyses demonstrated significantly higher odds of a PJI, SSI, and MUA at 90 days, 1 year, and 2 years for all patients who had staged nail removal TKA (P < .001). CONCLUSIONS: There was an observed association between concurrent IM nail removal and a decreased risk of PJI, SSI, and MUA when compared to patients who had nail removal in a staged fashion. However, this does not discount the utility of the staged approach, as it may be necessary for patients less tolerant to longer operative times.

Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection.

Aim: Radiographic analysis of lower limb alignment is crucial for the planning and evaluation of deformity correction. Assessment in the sagittal plane is often overlooked compared with the coronal plane for a variety of reasons. We aimed to investigate the relationship between the femoral head in the sagittal plane and femoral neck version in the axial plane, and how sagittal femoral bowing angle (sFBA) may contribute. Materials and methods: Twenty-five each of high (1-2 standard deviations above mean), normal (2.5° below to 2.5° above the mean), and low (1-2 standard deviations below the mean) version femurs were randomly selected from an osteological collection database, photographed and measured for sFBA and sagittal offset of femoral head from the distal femur axis. Lines were drawn within the proximal and distal quartiles of the shaft to create sFBA. The offset of the distal quartile line and the femoral head was also measured. High intra- and inter-observer correlations were established. The relationship between parameters was assessed using the Pearson coefficient (r). Results: Sagittal offset of the femoral head from the distal femur axis was found to be highly correlated with sFBA (r = 0.78), and only mildly with femoral neck version (r = 0.52). Sagittal femoral bowing angle and femoral neck version share no relationship (r = 0.05). Conclusions: Neither the sFBA nor sagittal femoral head offset is strongly associated with femoral neck version. Clinical significance: Our data reinforce the need for long leg lateral films to include the femoral head in sagittal deformity analysis, as imaging limited to the knee will not account for the effect of bowing on femoral head position. How to cite this article: Ho D, Liu RW, Mcclure PK. Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection. Strategies Trauma Limb Reconstr 2023;18(1):12-15.

Current Clubfoot Practices: POSNA Membership Survey.

Clubfoot management has advanced in the 21st century with increases in formal training, practitioner experience, and improved casting/bracing constructs. The Ponseti method is the gold standard, yet variations in application persist. This survey aims to identify current treatment practices among clubfoot practitioners within the Pediatric Orthopaedic Society of North America (POSNA). A 23-question online survey of members was conducted between June and August 2021. Eighty-nine respondents self-identified as clubfoot providers. Of these, 93.1% had an MD degree, 23.6% possessed >30 years' experience, and the majority (65.6%) worked in a teaching hospital associated with a medical school. Most responders (92.0%) were pediatric fellowship trained. A total of 51.7% had participated in a clubfoot training course. More than half (57.5%) noted changes to clubfoot management practices throughout their training. A majority used between four and seven (88.7%) long leg casts (98.4%), changed at seven-day intervals (93.4%). Plaster (69.4%) was most commonly used. The most common bracing device was Mitchell-Ponseti (72.9%). A mean 84.8% of clubfeet required tenotomy. The most common anesthetic agent was numbing gel (43.0%). Tenotomies mostly occurred in patients aged <6 months (63.1%). Tenotomy locations were operating room (46.5%), clinic (45.4%) and procedure room (8.1%). Cast removal was primarily performed with saws (54.7%). The mean incidence of observed cast burns was 5.5%. Most providers did not use a device to prevent cast burns (76.6%). Reported cast complications included slippage (85.9%), skin irritation (75.8%), and saw-related injuries (35.9%). Clubfoot management variations exist in orthotics, tenotomy indications and practices, and cast material. Casting complications continue to be a problem. Further studies are warranted to determine if certain practices predispose patients to specific complications.

Congenital Synostosis of the Knee: Long-term Outcomes of Limb Reconstruction Surgery.

BACKGROUND: Congenital synostosis of the knee is a rare condition with limited data on treatment options and outcomes. This study reports clinical findings, treatment approach, and surgical/clinical outcomes for congenital synostosis of the knee. METHODS: An institutional review board-approved retrospective review of patients with congenital synostosis of the knee presenting to 2 institutions between 1997 and 2021 was performed. RESULTS: Eight patients (13 knees) with a median follow-up of 11.3 years (3.3 to 17 y) were included. Seven patients had associated syndromes. Patients presented with an average knee flexion deformity of 100° (range 60 to 130°) and delayed walking ability. Seven patients had associated upper extremity hypoplasia/phocomelia. The average age at the index surgery was 4.3 years (range 1.2 to 9.2 y). Synostosis resection with gradual deformity correction was performed in most patients. An attempt was made at a mobile knee in some patients, but all went on to knee fusion. Mean flexion deformity at final follow-up was 11.6° (range: 0 to 40°) and 5 limbs were fused in full extension. Mean limb length discrepancy at final follow-up was 6.8 cm (range: 0 to 8 cm). All patients maintained their improved ambulation status at final follow-up. Twenty-two complications were identified. CONCLUSIONS: Reliable correction of the deformity associated with congenital knee synostosis was achieved at a median follow-up of 11 years. Importantly, all patients maintained their improved ambulation at final follow-up. This is the largest study on patients with congenital knee synostosis and outlines a reconstructive approach to improve ambulatory status. LEVEL OF EVIDENCE: Level IV.

Mechanical Failures in Magnetic Intramedullary Lengthening Nails.

BACKGROUND: Magnetic intramedullary lengthening nails (MILNs) have gained popularity in recent years for the treatment of limb-lengthening discrepancies. We sought to catalog mechanical failures and their prevention and management in a large, single-institution series. We specifically assessed the rate of mechanical failures, the types of failures observed, and management strategies. METHODS: We retrospectively reviewed 377 patients (420 limbs) who underwent limb lengthening with early (P1) or later (P2) MILN iterations with ≥12-month follow-up. Mechanical failure was defined as mechanical breakage of the instrumentation or nail and/or failure of the internal lengthening mechanism. Failure assessment was arranged by lengthening phases and was sorted with a complication classification system. All lengthening and alignment parameters were assessed radiographically. RESULTS: Mechanical failure was observed in 40 nails (9.5%), most of which (63%) were corrected with an additional surgical procedure. The mechanical failure rate was 11.3% in P1 nails and 9% in P2 nails. Two nails failed the intraoperative distraction test, and 1 nail was found to have a broken washer during the insertion phase. Sixteen nails had mechanical failures in the lengthening phase. Some nails (8 of 16) required nail replacement surgery. Thirteen nails failed during the consolidation phase; 7 of these cases were managed by replacement with either a functional MILN or a conventional intramedullary nail. Eight failures happened during the extraction phase and were managed intraoperatively. CONCLUSIONS: A 9.5% overall rate of mechanical failure of MILNs was observed in this large series. Resolution was achieved with an additional surgery in most cases. Nail distraction and weight-bearing compliance should be closely monitored during the lengthening and consolidation phases. Nail removal can be difficult and requires a careful study of radiographs for locking-screw bone overgrowth and backup removal equipment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Multiplier Method for Predicting the Sitting Height Growth at Maturity: A Database Analysis.

This study aims to develop multipliers for the spine and sitting height to predict sitting height at maturity. With the aid of longitudinal and cross-sectional clinical databases, we divided the total sitting height, cervical, thoracic, and lumbar lengths at skeletal maturity by these same four factors at each age for each percentile given. A series of comparisons were then carried out between the multipliers as well as the percentiles and the varied racial and ethnic groups within them. Regarding sitting height, there was little variability and correlated with the multipliers calculated for the thoracic and lumbar spine. The multiplier method has demonstrated accuracy that is not influenced by generation, percentile, race, and ethnicity. This multiplier can be used to anticipate mature sitting height, the heights of the thoracic, cervical, and lumbar spine, as well as the lack of spinal growth after spinal fusion surgery in skeletally immature individuals.

Risk of Avascular Necrosis with The Modified Dunn Procedure in SCFE Patients: A Meta-Analysis.

In situ stabilization is a widely accepted treatment for slipped capital femoral epiphysis (SCFE) despite risks of avascular necrosis (AVN) and femoroacetabular impingement (FAI). The modified Dunn procedure with surgical hip dislocation attempts to maintain epiphyseal perfusion and allows anatomic epiphyseal repositioning, theoretically reducing AVN and FAI risks. We systematically evaluated the literature, elucidating overall and stability-stratified rates of AVN following the modified Dunn procedure, and revision rates in non-AVN patients. Using Ovid and MEDLINE (PubMed), studies involving the modified Dunn procedure were evaluated for age, stability, preoperative slip (Southwick) angle, ROM at follow-up, outcome metrics, and revisions. Utilizing a random effect model of proportions, we determined overall and stability-stratified AVN rates, and revision rates in patients without AVN.673 patients (688 SCFEs) who underwent modified Dunn procedure were included. Overall AVN rate was 14.3% with a 95% Confidence Interval (CI) of 9.3 to 20.2%. AVN rate in stable slips was 10.9% (95% CI: 6.0 to 17.1%) and 19.9% (95% CI: 12.8% to 28.1%) in unstable slips. Revision rate in non-AVN patients was 13.3% (95% CI: 8.3% to 19.2%). Fixation failures occurred following K-wire or small-caliber (<6.5 mm) screw fixation. Overall mean Harris Hip Score (HHS) was excellent (>90 points). Mean HHS was 98.9 points (range of means: 86 to 99 points) in stable cases, and 90.5 points (range of means: 73 to 98 points) in unstable cases. Patients undergoing modified Dunn procedure had excellent clinical outcomes and low incidences of AVN. Further studies are needed to determine if modified Dunn osteotomy with surgical hip dislocation is a viable alternative to in situ pinning for treatment of severe SCFE.

Growth Deceleration for Limb Length Discrepancy: Tension Band Plates Followed to Maturity.

Objective: There are several alternative methods for accomplishing epiphysiodesis of the longer limb to address limb length discrepancy (LLD). Consensus is lacking regarding the optimal timing of the intervention and which method is most efficacious. We reviewed a large group of patients with anisomelia treated by tethering with tension band plates (TBP) and who had attained skeletal maturity. We discuss our preferred timing and technique while noting the complications and how they were managed. Materials and methods: With IRB approval, we reviewed 66 subjects including 32 boys and 34 girls, ranging in age from 3 to 16.6 years at the time of physeal tethering, who were destined to have between 2 and 9 cm LLD at maturity. Inclusion criteria were: (1) at least 1 year of predicted growth at the time of tethering; (2) minimum 18-month follow-up and (3) minimum Risser stage 1 (R1) in the last radiologic study. There were 35 distal femoral, 25 pan genu and five proximal tibial procedures. Patients were seen bi-annually with weight-bearing full-length radiographs to ascertain neutral alignment and assess limb lengths. Results: We defined a successful outcome to be <1.5 cm of residual discrepancy. Iatrogenic mechanical axis deviation, observed in nine patients (five varus and four valgus), was successfully managed by repositioning the implants. While the under-corrected patients presented too late to achieve equalization, they benefited from partial improvement. Due to lack of timely follow-up, one patient over-corrected by 2 cm and had a femoral shortening at the time of correcting contralateral femoral anteversion. One patient required a distal femoral osteotomy to correct recurvatum at maturity. Conclusion: Properly timed and executed, TBP is an efficacious and reversible means of growth deceleration, rather than growth arrest, that may be applied in a wide age range of patients with modest anisomelia regardless of aetiology. This method offers potential advantages over purportedly rapid and definitive techniques such as percutaneous epiphysiodesis (PE) or percutaneous epiphysiodesis with transphyseal screws (PETS). Level of evidence: Level III. Retrospective series without controls. How to cite this article: Stevens P, Desperes M, McClure PK, et al. Growth Deceleration for Limb Length Discrepancy: Tension Band Plates Followed to Maturity. Strategies Trauma Limb Reconstr 2022;17(1):26-31.

Does Focal Osteolysis in a PRECICE Stryde Intramedullary Lengthening Nail Resolve after Explantation?

Concerns surrounding osteolysis near and around the modular junction of a stainless-steel intramedullary lengthening rod prompted a manufacturer recall from the United States market in early 2021. These actions were preceded by similar steps taken in Europe. A concomitant review of stainless-steel lengthenings at our institution demonstrated signs of adverse tissue reaction including periosteal reaction and osteolysis at the modular junction and/or male-sided locking screws. Nearly half of our patients presented with these findings on radiographic images. At the time of the previous review, only half of the nearly 60 implanted stainless-steel devices met a 6-month follow-up. At this juncture, many patients have had their devices explanted. Given the suspected adverse tissue reactions caused by a component of the internal device, we sought to examine the rate of osteolysis post-explantation following removal of a stainless-steel nail. We reviewed a consecutive series of patients who underwent implantation of a stainless-steel limb lengthening device in the femur and/or tibia at a single institution between December 2018 and December 2020. Patients were included if their device was explanted. Periosteal reaction and osteolysis was classified according to a novel and validated classification system, as analyzed by five fellowship-trained surgeons. In addition, changes observed prior to explantation were tracked post-explantation to assess for resolution. The incidence of periosteal reaction and osteolysis prior to explantation was 22/57 (39%) and 15/57 (26%), respectively. Of the 15 patients with osteolysis pre-explantation, 14 patients' implants were explanted. Of these, eight patients had available follow-up films. Two patients were identified as having partial osteolysis resolution at mean 1-year follow-up, while six patients were identified as having complete osteolysis at mean 18-months follow-up. Periosteal tissue reaction and osteolysis largely resolved following explantation in a subset of patients. These results provide further support to the claim that the stainless-steel device contributed to the changes seen. Further follow-up is warranted to examine the longer-term effects of adverse tissue reaction in this patient population.

Increased Arthrodesis Rates in Charcot Neuroarthropathy Utilizing Distal Tibial Distraction Osteogenesis Principles.

Charcot neuroarthropathy of the hindfoot and ankle poses substantial challenges due to deformity, segmental bone loss, chronic infection, and difficulty with bracing. Hindfoot or ankle arthrodesis is often employed at high rates of complications and nonunion. This study reports 15 consecutive patients with Charcot neuroarthropathy who underwent tibiotalocalcaneal or tibiocalcaneal fusion with simultaneous distal tibial distraction osteogenesis with a mean follow-up period of 20.2 ± 5.66 months. Arthrodesis rate was 93.3% (14 patients) with mean time to fusion of 4.75 ± 3.4 months. One hypertrophic nonunion occurred at the arthrodesis site. Complete consolidation of 4 cortices was achieved at the distraction site in 93.3% of patients (14 patients) with a mean duration to consolidation of 9.8 ± 3.3 months. One patient experienced hypertrophic nonunion at the regeneration site. The authors report a technique to enhance arthrodesis rates in Charcot neuroarthropathy by combining distal tibial distraction osteogenesis with simultaneous tibiotalocalcaneal or tibiocalcaneal arthrodesis for hindfoot fusion and salvage. Distraction osteogenesis supports enhanced vascularity to the arthrodesis site.Level of Clinical Evidence: Level 4.

Does An Osteotomy Performed in Congenital Pseudarthrosis of the Tibia Heal?

BACKGROUND: Shortening and deformity of the tibia commonly occur during the treatment of congenital pseudarthrosis of the tibia (CPT). The role of osteotomies in lengthening and deformity correction remains controversial in CPT. This study evaluates the approach to and outcome after osteotomy performed in CPT. METHODS: We performed an IRB approved retrospective review of consecutive patients with CPT treated at our institution from 2010 through 2019. Patients who underwent osteotomies were included in this study. RESULTS: Nine patients (10 osteotomies-5 proximal metaphyseal and 5 diaphyseal) with a median age at osteotomy of 8.9 years (range: 4 to 21 y) were included. Six patients had neurofibromatosis-1, 1 had cleidocranial dysplasia, and 2 patients had idiopathic CPT. Four osteotomies were performed for deformity correction, 3 osteotomies to allow intramedullary instrumentation, and 3 osteotomies for lengthening. Five osteotomies were preceded by zolendronate treatment before surgery. Nine were fixed with a rod supplemented with external fixation (7) or locking plates (2). One osteotomy was stabilized with locked intramedullary nailing alone. Four osteotomies were supplemented with autologous bone graft, and bone morphogenic protein-2 was utilized in 3 osteotomies. Median time to healing was 222.5 days (range: 124 to 323 d). One osteotomy (locked intramedullary nailing) required grafting at 5.5 months and then healed uneventfully. Median healing index for patients undergoing lengthening was 57.9 days/cm (range: 35 to 81 d/cm). All 3 osteotomies performed for lengthening required a second osteotomy for preconsolidation at a mean of 34 days. Other complications included compartment syndrome requiring fasciotomy (n=2), tibial osteomyelitis (n=1), and fracture distal to cross-union (n=1). CONCLUSIONS: Contrary to much of the established practice, osteotomies may be safely performed in CPT for various indications. All osteotomies healed with only 1 osteotomy requiring secondary bone grafting. Although time to healing of the osteotomy was generally prolonged, this study suggests, somewhat surprisingly, that preconsolidation can occur frequently in lengthening procedures. LEVEL OF EVIDENCE: Level IV-case series.

Challenges with Fassier-Duval rod exchanges in congenital pseudarthrosis of the tibia: explant roadblock and solution.

Congenital pseudarthrosis of the tibia (CPT) is characterized by anterolateral tibial bowing and hamartomatous periosteum that predisposes it to fracture. Fassier-Duval telescopic rods can improve the structural integrity of bone segments after reconstruction. We present our experience treating CPT with the Fassier-Duval rod and a novel technique for Fassier-Duval exchange that was developed after extraction failed in one patient. Patients were identified who underwent treatment with Fassier-Duval rods for CPT between 2007 and 2016 and had undergone their first rod exchange. Medical records were reviewed, and complications were classified using the system of Cherkashin. Four patients had an average age at the initial insertion of 6 years 4 months (4-9 years). The average follow-up duration after initial Fassier-Duval implantation was 5.4 years (2.7-8.1 years). Seven Category 2 complications were associated with the Fassier-Duval rod: interlocking K-wire migration (2), lengthening failure (2), explant failure (1), distal migration of female rod through physis (1) and male rod portion proximally migrating through physis (1). Three patients underwent one rod exchange [average 3.2 years after implantation (range, 2.7-3.9 years)]. One patient underwent two rod exchanges (2.9 and 6.9 years after initial implantation). The second attempt at exchange failed; this failure prompted the development of custom trephines to remove the hard bone that can encase the distal male segment. The use of custom trephines was made necessary by dense sclerotic bone at the previous pseudarthrosis site. We recommend that custom trephines be available during Fassier-Duval rod extraction to avoid failed retrieval. Level of evidence: Level IV (Case series).

Sagittal Plane Assessment in Deformity Correction Planning: The Sagittal Joint Line Angle.

Aim: Evaluate the validity of a recent approach to calculate the knee flexion or extension contracture contributing to the overall sagittal deformity using the sagittal mechanical axis angle (SMAA) for the overall alignment assessment and sagittal joint line angle (SJLA) for soft tissue contribution. The methods of evaluating these angles and their clinical applications are discussed. Materials and methods: In total, 107 normal limbs met the criteria and were divided into two groups: skeletally mature and immature. Sagittal alignment was evaluated using the Bone Ninja iPad application, and the posterior distal femoral angle (PDFA), posterior proximal tibial angle (PPTA), SMAA and SJLA were recorded. Results: In skeletally immature patients, mean SJLA was 13.46° [standard deviation (SD), 4.55°], and in mature patients, it was 16.91° (SD, 2.948°). The PDFA and PPTA were consistent with previously published measurements. Conclusion: The SJLA method is a practical way to quantify the soft tissue contribution and degree of contracture. It can also be used for monitoring deterioration or improvement of knee range of motion during lengthening or physical therapy. Clinical significance: All patients in this study presented to our clinic with symptoms on the contralateral side. This, in addition to the retrospective nature, was a limitation in our study.We recommend a validity study to compare our SJLA method to the classic anterior cortical line angle (ACL) method in addition to an inter-observer and intra-observer reliability study for the SJLA. We also recommend a study on completely normal asymptomatic subjects to better standardise the angle measurements in skeletally immature patients at different ages. How to cite this article: Abalkhail TB, McClure PK. Sagittal Plane Assessment in Deformity Correction Planning: The Sagittal Joint Line Angle. Strategies Trauma Limb Reconstr 2022;17(3):159-164.

Removal of a Broken Stainless-Steel Intramedullary Lengthening Stryde Nail: A Case Report and Review of the Literature.

CASE: We report a 15-year-old female patient who underwent femur lengthening with a stainless steel intramedullary lengthening Stryde nail that broke at the end of the lengthening course and required removal. Given the solid noncannulated nature of the nail, this required special strategy to remove broken parts. CONCLUSION: Stryde nails are stainless steel lengthening nails that were developed to allow more freedom with weight bearing. Regardless of this change, hardware failure remains possible. In addition to maintaining regenerate integrity, a surgeon must be creative when attempting to remove solid nail types because many techniques for removing failed hardware were developed for cannulated devices.

Congenital Pseudarthrosis of the Tibia Associated With Cleidocranial Dysostosis: Case Report and Literature Review.

CASE: We describe a case of 2 individually rare diseases existing comorbidly in the form of congenital pseudarthrosis of the tibia (CPT) coincident with cleidocranial dysostosis and provide a review of the literature, including the sole preexisting documented coincidence. CONCLUSION: Understanding, treatment, and surgical protocol of CPT have changed considerably since this comorbidity was last reported. Updates include synostosis, periosteal grafting, the use of bone morphogenetic protein, and bisphosphonates. Our case varies from the previous in associated disorder and family history. The relationship between CBFA1 and RUNX2 genes may hold the key, but further study is needed.

Biopsy Proven Focal Osteolysis in a Stainless-Steel Limb-Lengthening Device: A Report of Three Cases.

Three pediatric patients presented with histologically confirmed osteolysis after limb lengthening with a magnetic, telescoping, stainless-steel device. The first patient's findings were discovered radiographically before routine removal of the device. In all cases, intraoperative histologic specimens taken from around the modular junction demonstrated particle-laden macrophages with suspicion for metal debris. Silicone debris was also identified. We found definitive osteolysis secondary to metal at the modular junction of three stainless-steel lengthening implants. This process is not well-understood in the setting of limb lengthening and should be examined further.

Simultaneous Bilateral Femoral and Tibial Lengthening in Achondroplasia.

Previous studies on lengthening for achondroplasia have reported bilateral extensive femoral lengthening followed by bilateral extensive tibial lengthening. To decrease trauma on soft tissues and joints, we propose bilateral simultaneous moderate femoral lengthening and moderate tibial lengthening followed by a similar repeat lengthening a few years later. Fifty patients with achondroplasia underwent 65 simultaneous bilateral femoral and tibial lengthening procedures. Segment lengthening amount and adverse events were obtained from medical records. Mean follow-up after bone healing was 35.6 months. Mean tibial lengthening was 52 mm; mean femoral lengthening was 72 mm. Average healing index was 1.4 months/cm for the tibia and 1 month/cm for the femur. Mean duration of treatment with external fixation was 6.7 months (range, 4.4-10.5 months). Thirty-eight (76%) of 50 patients experienced one or more adverse events during lengthening. We observed 78 adverse events, 35 (45%) of which required additional surgical procedures. All resolved by the end of treatment. Mechanical axis deviation improved from a mean of 15 mm medially to 8 mm medially. Simultaneous lengthening of four segments in patients with achondroplasia is a feasible strategy. Compared with isolated femoral or tibial lengthening, distributing the lengthening between the femur and tibia decreases total external fixator time.

Reconstructive Options for Tibial Bone Defects.

Segmental bone defects of the tibia are amenable to multiple treatment options including classic bone transport, shortening and then lengthening, induced membrane technique, transport over a nail, free fibular grafting, and medial transport of the ipsilateral fibula. These treatment options have relative advantages and disadvantages, depending on defect size, soft-tissue characteristics, the presence or absence of infection, and associated morbidity. Relatively, few large comparative studies exist, and surgeons are left to their own experience and the opinion of experts within the field to guide surgical decision-making.

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.