Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Symposium: Advances in Limb Lengthening and Reconstruction 16 articles

Articles

Periosteal Grafting for Congenital Pseudarthrosis of the Tibia: A Preliminary Report

Ahmed M. Thabet MD, Dror Paley MD, Mehmet Kocaoglu MD, Levent Eralp MD, John E. Herzenberg MD, Omer Naci Ergin MD The results of treatment of congenital pseudarthrosis of the tibia (CPT) are frequently unsatisfactory because of the need for multiple operations for recalcitrant nonunion, residual deformities, and limb-length discrepancies (LLD). Although the etiology of CPT is basically unknown, recent reports suggest the periosteum is the primary site for the pathologic processes in CPT. We hypothesized complete excision of the diseased periosteum and the application of a combined approach including free periosteal grafting, bone grafting, and intramedullary (IM) nailing of both the tibia and fibula combined with Ilizarov fixation would improve union rates and reduce refracture rates. We retrospectively reviewed 20 patients at two centers. The minimum followup was 2 years (mean, 4.3 years; range, 2–10.7 years). Union was achieved after the primary operation in all patients. Ten refractures occurred in eight of the 20 patients (two each in two patients, one each in six patients). Seven patients underwent seven secondary surgical procedures to simultaneously treat refracture and angular deformities. We used bisphosphonate as adjuvant therapy in three patients with refracture without subsequent refracture. We performed no amputations in these 20 patients. All patients were braced through skeletal maturity. Combining periosteal and bone grafting, IM nailing, and Ilizarov fixation is an effective treatment. IM nailing decreases the severity of subsequent fracture.,[object Object]

Bone Graft Harvest Using a New Intramedullary System

Mohan V. Belthur MD, Janet D. Conway MD, Gaurav Jindal MD, Ashish Ranade MD, John E. Herzenberg MD Obtaining autogenous bone graft from the iliac crest can entail substantial morbidity. Alternatively, bone graft can be harvested from long bones using an intramedullary (IM) harvesting system. We measured bone graft volume obtained from the IM canals of the femur and tibia and documented the complications of the harvesting technique. Donor site pain and the union rate were compared between the IM and the traditional iliac crest bone graft (ICBG) harvest. Forty-one patients (23 male, 18 female) with an average age of 44.9 years (range, 15–78 years) had graft harvested from long bones using an IM harvest system (femoral donor site, 37 patients; tibial donor site, four patients). Forty patients (23 male, 17 female; average age, 46.4 years; range, 15–77 years) underwent anterior ICBG harvest. We administered patient surveys to both groups to determine pain intensity and frequency. IM group reported lower pain scores than the ICBG group during all postoperative periods. Mean graft volume for the IM harvest group was 40.3 mL (range, 25–75 mL) (graft volume was not obtained for the ICBG group). Using an intramedullary system to harvest autogenous bone graft from the long bones is safe provided a meticulous technique is used.,[object Object]

Managing Flexion Knee Deformity Using a Circular Frame

Gamal Ahmed Hosny MD, Mohamed Fadel MD Knee flexion deformity can cause marked physical disability. Acute correction, whether nonoperative or operative, may lead to serious complications. We treated 50 patients (71 knees) between 1994 and 2002 with the Ilizarov external fixator. The deformity was gradually corrected using Ilizarov principles. Of the 50 patients, 29 were affected unilaterally and 21 bilaterally. In 15 patients, there were associated deformities. In no patient did we surgically release soft tissues; in two patients with arthrodesed or congenitally fused knees, we performed osteotomy before distraction. All patients were assessed clinically and radiographically. We assessed knee flexion angle, range of motion, stability, presence of pain, and healing index. After a minimum followup of 1 year (mean 3.7 years; range, 1–8 years), 18 of 20 of the preoperatively nonambulatory patients having bilateral surgery could walk at last followup. Complications included pin tract infection in all patients, knee subluxation in three patients, and fracture related to treatment in seven patients. We believe gradual correction using a circular frame an effective method to treat flexion knee contractures. In patients with bilateral deformities, improvement in functional activity may be expected in most patients.,[object Object]

Methods for Assessing Leg Length Discrepancy

Sanjeev Sabharwal MD, Ajay Kumar MD The use of accurate and reliable clinical and imaging modalities for quantifying leg-length discrepancy (LLD) is vital for planning appropriate treatment. While there are several methods for assessing LLD, we questioned how these compared. We therefore evaluated the reliability and accuracy of the different methods and explored the advantages and limitations of each method. Based on a systematic literature search, we identified 42 articles dealing with various assessment tools for measuring LLD. Clinical methods such as use of a tape measure and standing blocks were noted as useful screening tools, but not as accurate as imaging modalities. While several studies noted that the scanogram provided reliable measurements with minimal magnification, a full-length standing AP computed radiograph (teleoroentgenogram) is a more comprehensive assessment technique, with similar costs at less radiation exposure. We recommend use of a CT scanogram, especially the lateral scout view in patients with flexion deformities at the knee. Newer modalities such as MRI are promising but need further investigation before being routinely employed for assessment of LLD.,[object Object]

A One-wire Method for Anatomic Reduction of Tibial Fractures with Ilizarov Frame

Giovanni Lovisetti MD, Lorenzo Bettella MD Traditional external fixator techniques do not always correct minor residual malalignment. We asked whether using a one-wire method that corrects minor malalignment with an olive traction wire placed in the plane of the deformity allowed (1) uniform healing, (2) proper alignment, and (3) adequate reduction of fracture gaps. We retrospectively evaluated 72 patients in whom we used closed tibial fracture reduction using a circular external frame. We identified the plane of the residual deformity after alignment on a traction table using a C-arm. In this plane, the final correction was performed with traction through an olive wire. Satisfactory alignment (less than 3° deviation from normal) was obtained in 68 of the 72 patients (94%), and satisfactory reduction (gaps less than 2 mm) attained in 51 (71%). In no case was the fracture site opened surgically. Four patients underwent additional alignment correction with conical washers outside the operating room but no other efforts were needed to obtain further reduction after the initial surgery. Fractures healed in an average of 20 weeks. We observed no major infections. The Ilizarov frame has been a valuable tool to achieve alignment and anatomic or near anatomic reduction of closed tibial fractures.,[object Object]

Correlation of Shear to Compression for Progressive Fracture Obliquity

David W. Lowenberg MD, Sean Nork MD, Frederick M. Abruzzo MD The accompanying shear force at the point of bone opposition is an important factor inherent to tibial fracture stability during axial loading. We determined at which angle of fracture obliquity shearing becomes a dominant force after stabilization with circular external fixation, and how modifications to the external fixator can reduce this effect. We constructed tibial fracture models with a successively increasing fracture angle obliquely (from 0° to 60°) to determine the stability in the classic Ilizarov frame and subsequent frame modifications during axial loading (maximum, 1000 N). Stability was determined by measuring the fracture line displacement for each fracture obliquity model after an applied axial load. Fracture line displacement was recorded as coordinate component changes as measured by an ultrasonic digitizer. We defined construct stability as less than 2 mm of fracture line migration with loading. More than 3500 data points were collected for this study. The classic Ilizarov construct successfully stabilized fractures with up to 30° of fracture obliquity, after which divergent instability occurs. The addition of proximal and distal perpendicular half-pins provides little benefit. Arced wires provided stability up to 40° fracture obliquity. A formal steerage pin construct provided stability for all fracture models (up to 60° of fracture obliquity) with all applied loads (up to 1000-N axial load).

DEXA as a Predictor of Fixator Removal in Distraction Osteogenesis

Neil Saran MD, FRCSC, Reggie C. Hamdy MD, FRCSC Premature removal of the fixator after a lengthening procedure can result in gradual bending or acute fracture of the regenerate. We reviewed the records of 26 patients who underwent 28 limb lengthenings between 1997 and 2005 to assess the post lengthening regenerate fracture rate and bone healing index when using dual energy xray absorptiometry (DEXA) to aid in deciding on when to remove the fixator. Sixteen male and 10 female patients with an average age at lengthening of 12.3 years underwent an average lengthening of 5.2 cm (range, 3–9.1 cm). Nineteen femurs and nine tibiae were lengthened. Serial monthly DEXA scans were analyzed for bone mineral density. Bone healing indices and post fixator removal complications were assessed. The fixators were removed once the bone mineral density had plateaued to a less than 10% increase and plain radiographs showed no obvious defects precluding fixator removal. There were no regenerate fractures and only one fracture in the proximal segment of the lengthened bone after apparatus removal and the healing index for the series averaged 47 d/cm (range, 20–73 d/cm). Using serial DEXA scans during the consolidation phase of lengthening has a low rate (3.6%) of fractures while maintaining an acceptable bone healing index without excessively increasing fixation time.,[object Object]

Limb Lengthening and Then Insertion of an Intramedullary Nail: A Case-matched Comparison

S. Robert Rozbruch MD, Dawn Kleinman BA, Austin T. Fragomen MD, Svetlana Ilizarov MD Distraction osteogenesis is an effective method for lengthening, deformity correction, and treatment of nonunions and bone defects. The classic method uses an external fixator for both distraction and consolidation leading to lengthy times in frames and there is a risk of refracture after frame removal. We suggest a new technique: lengthening and then nailing (LATN) technique in which the frame is used for gradual distraction and then a reamed intramedullary nail inserted to support the bone during the consolidation phase, allowing early removal of the external fixator. We performed a retrospective case-matched comparison of patients lengthened with LATN (39 limbs in 27 patients) technique versus the classic (34 limbs in 27 patients). The LATN group wore the external fixator for less time than the classic group (12 versus 29 weeks). The LATN group had a lower external fixation index (0.5 versus 1.9) and a lower bone healing index (0.8 versus 1.9) than the classic group. LATN confers advantages over the classic method including shorter times needed in external fixation, quicker bone healing, and protection against refracture. There are also advantages over the lengthening over a nail and internal lengthening nail techniques.,[object Object]

Percutaneous Nonviral Delivery of Hepatocyte Growth Factor in an Osteotomy Gap Promotes Bone Repair in Rabbits: A Preliminary Study

Hidenori Matsubara MD, Hiroyuki Tsuchiya MD, PhD, Koji Watanabe MD, PhD, Akihiko Takeuchi MD, PhD, Katsuro Tomita MD, PhD Hepatocyte growth factor (HGF) was initially identified in cultured hepatocytes and subsequently reported to induce angiogenic, morphogenic, and antiapoptotic activity in various tissues. These properties suggest a potential influence of HGF on bone healing. We asked if gene transfer of human HGF (hHGF) into an osteotomy gap with a hemagglutinating virus of Japan-envelope (HVJ-E) vector promotes bone healing in rabbits. HVJ-E that contained either hHGF or control plasmid was percutaneously injected into the osteotomy gap of rabbit tibias on Day 14. The osteotomy gap was evaluated by radiography, pQCT, mechanical tests, and histology at Week 8. The expression of hHGF was evaluated by reverse transcriptase–polymerase chain reaction and immunohistochemistry at Week 3. Radiography, pQCT, and histology suggested the hHGF group had faster fracture healing. Mechanical tests demonstrated the hHGF group had greater mechanical strength. The injected tissues at 3 weeks expressed hHGF mRNA by reverse transcriptase–polymerase chain reaction. hHGF-positive immunohistochemical staining was observed in various cells at the osteotomy gap at Week 3. The data suggest delivery of hHGF plasmid into the osteotomy gap promotes fracture repair, and HGF could become a novel agent for fracture treatment.

Circular External Fixation Frames with Divergent Half Pins: A Pilot Biomechanical Study

Christopher Lenarz MD, Gary Bledsoe PhD, J. Tracy Watson MD The use of hexapod circular external fixators has simplified the ability to correct complex limb deformities without cumbersome frame reconfigurations. These frames are applied primarily using half pin mountings and may be difficult to utilize given the constraints of traditional half pin constructs. We compared the biomechanical performance of simplified divergent half pin frames to mountings currently being utilized for application of hexapod frames. Three 6-mm half pins per limb segment were placed into sawbones at 60° divergent angles in both the sagittal and coronal planes in a 2-cm diaphyseal fracture gap model. Pin mountings were attached to a standardized four-ring construct. This was compared to similar four-ring frames with two differing pin/wire configurations: (1) two tensioned wires per ring placed at 90° angles, a total eight wires; and (2) two 5-mm half pins per ring placed at 90° angles, a total eight half pins. The divergent 6-mm half pin frames demonstrated similar performance compared the standardized tensioned wire and 5-mm half pin frames in terms of axial micromotion and angular deflection. Based on the mechanical performance of these divergent half pin frames we believe they can be used clinically without detrimental consequences.

Pediatric Deformity Correction Using a Multiaxial Correction Fixator

James J. McCarthy MD, Ashish Ranade MD, Richard S. Davidson MD Circular fixators have been used successfully to correct multiplanar deformities but are often cumbersome and may be difficult to apply. We determined whether a monolateral fixator, which allows for correction of angular deformity and displacement in three planes, can correct lower extremity deformities to within normal radiographic means (anatomic lateral distal femoral angle, anatomic medial proximal tibial angle, and tibial femoral angle). We retrospectively reviewed the clinical records and radiographs of 22 consecutive patients (25 limbs) who underwent deformity correction using a new multiaxial monolateral external fixator. The patients were 4 to 16 years of age. We had a minimum 1.2-year followup (mean, 2.14 years; range, 1.2–3.1 years). Those with primary femoral and tibial deformities had improvements in the mean deviation from normal of the anatomic lateral distal femoral angle, anatomic medial proximal tibial angle and tibial femoral angle. Patients with Blount’s disease had improvements in the mean anatomic medial proximal tibial angle from 59.9º to 87.8º. Five patients had complications (two pin site infections, one premature consolidation, one knee flexion contracture, one recurrence of varus). Six patients developed secondary deformities, all of which were corrected using the primary or secondary hinge. We conclude this fixator can produce satisfactory results with relatively few complications.,[object Object]

Femoral Deformity Correction in Children and Young Adults Using Taylor Spatial Frame

Salih Marangoz MD, David S. Feldman MD, Debra A. Sala MS, PT, Joshua E. Hyman MD, Michael G. Vitale MD, MPH The Taylor spatial frame (TSF) has been used commonly in children and young adults. Its use in the tibia is more extensively studied and applied than in the femur. We asked whether normal alignment can be achieved with accuracy during correction of femoral deformities while avoiding major complications in children and young adults. We retrospectively reviewed the clinical and radiographic records of 20 patients (22 limbs), ages 5.9 to 24.6 years, who underwent a TSF for femoral deformity. Etiology included a number of diagnoses of the pediatric age. Minimum followup was 4.5 months (mean, 15.7 months; range, 4.5–35 months). The mean time in frame was 6.2 months (range, 2.6–19 months). Frontal and sagittal plane deformities were corrected to within normal values. A mean limb lengthening of 4.9 cm (range, 1.5–9 cm) was performed in eight femora in seven of which the limb length discrepancy was a secondary concern. External fixation index in the lengthening subgroup was 2.2 months/cm. The 15 complications in 13 limbs included pin tract infection, knee stiffness, delayed union, skin irritation, and posterior knee subluxation. No complications occurred in nine limbs. Computer-assisted femoral deformity correction with six-axis deformity analysis and the TSF is an accurate and safe technique in children and young adults.,[object Object]

Tibial Lengthening: Extraarticular Calcaneotibial Screw to Prevent Ankle Equinus

Mohan V. Belthur MD, Dror Paley MD, Gaurav Jindal MD, Rolf D. Burghardt MD, Stacy C. Specht MPA, John E. Herzenberg MD Between 2003 and 2006, we used an extraarticular, cannulated, fully threaded posterior calcaneotibial screw to prevent equinus contracture in 10 patients (four male and six female patients, 14 limbs) undergoing tibial lengthening with the intramedullary skeletal kinetic distractor. Diagnoses were fibular hemimelia (two), mesomelic dwarfism (two), posteromedial bow (one), hemihypertrophy (one), poliomyelitis (one), achondroplasia (one), posttraumatic limb-length discrepancy (one), and hypochondroplasia (one). Average age was 24.5 years (range, 15–54 years). The screw (length, typically 125 mm; diameter, 7 mm) was inserted with the ankle in 10° dorsiflexion. Gastrocnemius soleus recession was performed in two patients to achieve 10° dorsiflexion. Average lengthening was 4.9 cm (range, 3–7 cm). Screws were removed after a mean 3.3 months (range, 2–6 months). Preoperative ankle range of motion was regained within 6 months of screw removal. No neurovascular complications were encountered, and no patients experienced equinus contracture. We also conducted a cadaveric study in which one surgeon inserted screws in eight cadaveric legs under image intensifier control. The flexor hallucis longus muscle belly was the closest anatomic structure noted during dissection. The screw should be inserted obliquely from upper lateral edge of the calcaneus and aimed lateral in the tibia to avoid the flexor hallucis longus muscle.,[object Object]