[Options and limits of leg length correction in paediatric orthopaedics]

For paediatric orthopaedic surgeons treating leg length discrepancy, knowledge of the available procedures and their options and limits is just as important as mastery of the very different surgical methods and implants, as well as the possible complications, in order to be able to advise and treat the children and adolescents and their parents comprehensively and in the best interests. Both the growth inhibiting procedures and the complex bone lengthening procedures require a great deal of experience to successfully guide patients and families through what is often a lengthy and sometimes complicated treatment process. Careful preoperative indications and planning, precise surgical techniques with suitable instruments and implants, and attentive postoperative check-ups are mandatory prerequisites for the desired therapeutic success.

Femoral Discrepancy After Childhood Bone Sarcoma Surgery Can Be Treated With Magnetic Intramedullary Nails

This study aims to determine whether femoral lengthening with a magnetic motorized intramedullary nail (PRECICE; NuVasive) is safe and effective in patients with discrepancy due to limb salvage performed for bone sarcomas before skeletal maturity. Six patients (male, 4; female, 2) with a mean age of 9.3 years (range, 4.8-12.8 years) at the time of index limb salvage surgery were retrospectively analyzed. Four patients had undergone biological reconstruction with liquid-nitrogen recycled frozen autograft shell and inlaid vascular fibula combination and 2 had undergone nonbiological reconstruction with distal femur modular tumor endoprosthesis. The mean age at PRECICE operation was 16.1 years (range, 13.4-20.1 years). The mean prelengthening femoral discrepancy was measured as 60 mm (range, 39-80 mm). Lengthening was achieved in 5 of these 6 patients. Although the PRECICE nail was successfully implanted in the sixth patient, lengthening could never be performed owing to failure to overcome the chronic diaphyseal nonunion first, as intended with compressive use of the nail. For the other 5 patients, in whom lengthening was performed, the mean lengthening was 45 mm (range, 35-52 mm), the mean ratio of achieved to planned lengthening was 93% (range, 74%-100%), and the mean bone-healing index was 41 days per cm (range, 24-69 days per cm). Mean Musculoskeletal Tumor Society score improved from 25.6 to 27.2 after lengthening. No major complications occurred. The outcomes of this study demonstrate that the PRECICE implant can safely and effectively correct femoral length discrepancy caused by limb salvage performed for osteosarcoma before skeletal maturity. [Orthopedics. 2023;46(1):27-34.].

[Paramedical care related to the implantation of a motorized spinal lengthening nail]

The Fitbone® system is one of the most recent motorized bone lengthening techniques. It allows a precise control of the extension while reducing pain and complications. It requires special assistance from the paramedical team, before and after the procedure, as it may cause adjustment problems in some patients.

What Are the Potential Benefits and Risks of Using Magnetically Driven Antegrade Intramedullary Lengthening Nails for Femoral Lengthening to Treat Leg Length Discrepancy?

BACKGROUND

Limb lengthening with magnetically driven intramedullary lengthening nails is a fast-developing field and represents an alternative to external fixators. Although previous studies have assessed the application of magnetically driven intramedullary lengthening nails, these studies have been heterogenous regarding the nailing approach, the bone treated, and the implant type; they also have analyzed relatively small patient groups at short follow-up durations.

QUESTIONS/PURPOSES

(1) Is femoral lengthening with magnetically driven antegrade intramedullary lengthening nails accurate and precise? (2) What are the most common complications of treatment? (3) What factors are associated with unplanned additional surgery?

METHODS

We retrospectively analyzed the longitudinally maintained database of our orthopaedic teaching hospital to identify all patients who underwent surgery for leg length discrepancy (LLD) between October 2014 and April 2019. In total, we surgically treated 323 patients for LLD of 2 cm or more. Of those 55% (177 of 323) were treated with distraction osteogenesis with magnetically driven intramedullary lengthening nails, 18% (59 of 323) with external fixation, and 27% (87 of 323) with epiphysiodesis around the knee. Based on that, 29% (93 of 323) of patients underwent unilateral femoral distraction osteogenesis with magnetically driven antegrade femoral lengthening nails and were eligible for analysis. No patient was excluded, and 3% (3 of 93) were lost before the minimum study follow-up of 2 years, leaving 97% (90 of 93) for analysis. Patients with a distal femoral deformity were treated via a retrograde femoral approach (10% [33 of 323]) or with external fixators (3% [10 of 323]) and were not included in this study. Distraction osteogenesis with magnetically driven intramedullary lengthening nails was not considered for patients with deep tissue infection, those with bone dimensions considered to be too small in relation to the available implants, and for patients younger than 8 years. This study included 90 patients (44 females, 43 left femora) treated for a median (interquartile range) preoperative LLD of 39 mm (32 to 52) at a median age of 15 years (14 to 17). The same limb lengthening system was applied in all patients. The median (IQR) follow-up was 35 months (24 to 78). Data were acquired through a chart review performed by someone not involved in the surgical care of the included patients. Data acquisition was supervised and curated by two of the involved surgeons. Accuracy was calculated as 100 - [(achieved distraction in mm - planned distraction in mm) / (planned distraction in mm) x 100] and precision as 100 - (relative standard deviation of accuracy). Treatment-associated complications were summarized descriptively and characterized as complications resulting in unplanned additional surgery or those not resulting in unplanned surgery. To analyze the risk of unplanned additional surgery by entity, we calculated odds ratios (ORs) comparing the incidence of unplanned additional surgery in the different entity cohorts with the idiopathic LLD cohort as a reference. By calculating ORs, we analyzed the risk for unplanned additional surgery depending on sex, age, surgery time, and previous lengthening. Due to the lack of long-term evidence about motorized lengthening nails remaining in situ and concerns about potential implant-related adverse effects, removal was routinely scheduled 1 year after consolidation. For implant removal, 92% (83 of 90) of patients underwent planned additional surgery, which was not recorded as an adverse event of the treatment. Ninety-seven percent (87 of 90) of patients completed lengthening with the implant remaining in situ until the end of distraction. The median (IQR) distraction length was 37 mm (30 to 45) with a median distraction index of 0.9 mm/day (0.7 to 1.0) and median consolidation index of 31 days/cm (25 to 42).

RESULTS

The calculated accuracy and precision were 94% and 90%, respectively. In total, 76% (68 of 90) of our patients experienced complications, which resulted in 20% (18 of 90) of patients undergoing unplanned additional surgery. The most common complication overall was adjustment of the distraction rate in 27% (24 of 90) of patients (faster: 16% [14 of 90]; slower: 11% [10 of 90]) and temporary restriction of knee motion, which occurred in 20% (18 of 90) of our patients and resolved in all patients who experienced it. The most serious complications were bacterial osteomyelitis and knee subluxation, which occurred in 3% (3 of 90) and 1% (1 of 90) of our patients, respectively. With the numbers available, we found only one factor associated with an increased likelihood of unplanned additional surgery: Patients with postinfectious LLD had higher odds of unplanned additional surgery than patients with idiopathic LLD (7% [1 of 15] versus 50% [3 of 6], OR 14.0 [95% CI 1.06 to 185.49]; p = 0.02). However, we caution readers this finding is fragile, and the confidence interval suggests that the effect size estimate is likely to be imprecise.

CONCLUSION

Femoral distraction osteogenesis with magnetically driven antegrade intramedullary lengthening nails appears to be an accurate and reliable treatment for femoral lengthening. However, depending on the etiology, a high risk of unplanned additional surgery should be anticipated, and a high proportion of patients will experience temporary joint stiffness. We recommend close orthopaedic follow-up and physiotherapy during treatment. This treatment of LLD can be considered alongside other nails, external fixators, and epiphysiodesis. Multicenter studies comparing this with other approaches are needed.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Has the Threshold for Epiphysiodesis Versus Lengthening Changed in the Era of Magnetically Controlled Nails?

INTRODUCTION

Limb length discrepancy (LLD) is common in both the pediatric and adult population. Length inequalities can be due to a multitude of etiologies including congenital, developmental, and acquired causes. There has been little consensus on the morbidity of LLD and, as a result, the threshold necessary for treatment of LLD to prevent morbidity. Advances in magnetically controlled lengthening devices achieve greater accuracy and patient satisfaction and create an opportunity to lower the threshold for limb lengthening.

DISCUSSION

Asymptomatic LLD is relatively common in both pediatric and adult populations. Only ~10% of the population has equal leg length. LLD of <5 cm may lead to long-term morbidities such as scoliosis, lower back pain, gait abnormalities, stress on hip or knee joint, and lower extremity symptomatic versus asymptomatic osteoarthritis. The teaching in most orthopaedic textbooks is to adjust the shoe if symptomatic for discrepancies up to 2 cm; consider an orthotic, epiphysiodesis, or skeletal shortening for 2.5 to 5 cm; and possible limb reconstruction for >5 cm. The assumption is that there are no long-term consequences of mild LLD. However, data in recent literature show that small discrepancies may contribute to pathologic changes such as pain, gait abnormalities, and osteoarthritis. Major advances have been made in limb lengthening over the past 40 years. The increased accuracy and superior patient satisfaction of the magnetically controlled lengthening nail versus external fixation methods argue for including lengthening for LLD of <5 cm.

CONCLUSION

If mild LLD can cause long-term pathology, it is important to counsel families on the full range of options for limb equalization no matter the size of the discrepancy. The evolution in technology and understanding of limb lengthening has provided additional safe surgical options. Therefore, the historic treatment protocol for addressing limb differences may need to include lengthening for smaller discrepancies even <2 cm.

[Treatment principles in bone reconstruction and limb lengthening of the lower extremity]

Limb length discrepancies, axis deviations and bone loss on a congenital, traumatic or infectious basis are treated with restoration of axis and bone elongation. The intention is to improve gait and function, to relieve pain caused by imbalance in the musculoskeletal system and to prevent degenerative joint disease. Modern motorized intramedullary nails spare the patients for external fixators, and thus complications are being reduced. X-ray, CT-based planning and a thorough clinical examination is essential for a good result. Complications are frequent, and treatment can be lengthy. Modern techniques have made treatment more gentle and allow a normal daily life during treatment and rehabilitation.

Clinical Results and Complications of Lower Limb Lengthening for Fibular Hemimelia: A Report of Eight Cases

Fibular hemimelia is a rare but the most common congenital long bone deficiency, encompassing a broad range of anomalies from isolated fibular hypoplasia up to substantial femoral and tibial shortening with ankle deformity and foot deficiency. Most cases of fibular hemimelia manifest clinically significant leg length discrepancy (LLD) with time that requires adequate correction by bone lengthening for stable walking. Bone lengthening procedures, especially those for pathological bones, are sometimes associated with severe complications, such as delayed consolidation, fractures, and deformities of the lengthened bones, leading to prolonged healing time and residual LLD at skeletal maturity. The purpose of this study was to review our clinical results of lower limb lengthening for fibular hemimelia.This study included 8 Japanese patients who diagnosed with fibular hemimelia from physical and radiological findings characteristic of fibular hemimelia and underwent single or staged femoral and/or tibial lengthening during growth or after skeletal maturity. LLD, state of the lengthened callus, and bone alignment were evaluated with full-length radiographs of the lower limb. Previous interventions, associated congenital anomalies, regenerate fractures were recorded with reference to medical charts and confirmed on appropriate radiographs. Successful lengthening was defined as the healing index <50 days/cm without regenerate fractures.A significant difference was observed in age at surgery between successful and unsuccessful lengthening. The incidence of regenerate fractures was significantly correlated with callus maturity before frame removal. LLD was corrected within 11 mm, whereas mechanical axis deviated laterally.Particular attention should be paid to the status of callus maturation and the mechanical axis deviation during the treatment period in fibular hemimelia.

Progressive lengthening of short congenital forearm stump in children for prosthetic fitting

PURPOSE

The sufficient length of congenital forearm stump is essential for prosthetic fitting. In our study we reviewed the results of a series of forearm stump lengthening, observed complications and their outcomes. We evaluated possibilities of combined technique to reduce or avoid problems and complications in forearm stump lengthening.

METHODS

We retrospectively reviewed 18 children who have undergone forearm stump lengthening. In all patients the forearm lengthening was performed by means of Ilizarov frame. Additional flexible intramedullary nailing (FIN) was applied in two cases.

RESULTS

The mean lengthening gain was 4.6 cm. The planned lengthening gain was obtained in all cases. The mean healing index (HI) was 34.1 days/cm. The most reduced HI was observed in two cases of combined technique (Ilizarov frame with FIN): 25.4 and 27.0 days/cm. Considering complications and outcomes the results were classified according to Lascombes: grade I--5 cases, IIa--10 cases, IIb--2 cases, IIIa--1 case. In the long term follow-up all patients used their prostheses fixed at the forearm stump with natural function of elbow joint.

CONCLUSION

Forearm progressive lengthening in children with congenital transverse deficiency of the forearm is justified in order to facilitate prosthetic procedures and to preserve natural function of elbow joint. Sufficient lengthening can be achieved within one operation with a low rate of major complications. In our experience a repeated lengthening of forearm stump is not mandatory.

Autologous fat graft as treatment of post short stature surgical correction scars

INTRODUCTION

Surgical limb lengthening is undertaken to correct pathological short stature. Among the possible complications related to this procedure, painful and retractile scars are a cause for both functional and cosmetic concern. Our team has already shown the efficacy of autologous fat grafting in the treatment of scars with varying aetiology, so we decided to apply this technique to scars related to surgical correction of dwarfism. A prospective study was conducted to evaluate the efficacy of autologous fat grafting in the treatment of post-surgical scars in patients with short-limb dwarfism using durometer measurements and a modified patient and observer scar assessment scale (POSAS), to which was added a parameter to evaluate movement impairment.

PATIENTS AND METHODS

Between January 2009 and September 2012, 36 children (28 female and 8 male) who presented retractile and painful post-surgical scars came to our unit and were treated with autologous fat grafting. Preoperative and postoperative mean durometer measurements were analysed using the analysis of variance (ANOVA) test and POSAS parameters were studied using the Wilcoxon rank sum test.

RESULTS

There was a statistically significant reduction in all durometer measurements (p-value <0.05) and in all but one of the POSAS parameters (p-value <0.05) following treatment with autologous fat grafting.

DISCUSSION

Surgical procedures to camouflage scars on lower limbs are not often used as a first approach and non-surgical treatments often lead to unsatisfactory results. In contrast, our autologous fat grafting technique in the treatment of post-surgical scars has been shown to be a valuable option in patients with short-limb dwarfism.

CONCLUSION

There was a reduction of skin hardness and a clinical improvement of all POSAS parameters in all patients treated. Moreover, the newly introduced POSAS parameter appears to be reliable and we recommend that it is included to give a more complete evaluation of patient perception.

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.

Quadricepsplasty: a sustained functional achievement in front of a deteriorated flexion gain

METHODS

Nineteen cases of extension contracture were operated upon by modified technique of Judet quadricepsplasty, one female and eighteen males. Results were evaluated by HSSKF score as well as Judet criteria.

PURPOSE

The hypothesis is that recurrence of adhesions underneath the quadriceps leads to loss of some of the gained intraoperative flexion range.

RESULTS

In this series, flexion range deteriorates but this was found to be statistically non significant on the functional score of the patients.

[The sphenomandibular ligament: an anatomical obstacle to ramus lengthening]

INTRODUCTION

The sphenomandibular ligament is strong and its insertion below the medial cut of the sagittal split osteotomy explains that it is a barrier to the mobilization of the distal segment. It is the main obstacle to ramus lengthening. We describe the disinsertion technique with an anatomical dissection.

SURGICAL TECHNIQUE

After sagittal split ramus osteotomy, we verify that a stable occlusion has been achieved without straining. In case of resistance, a 90° angled periosteal rugine is introduced below the periosteum, against the medial cortex. It is used to detach the last fibers of the medial pterygoid muscle under visual control, and it is carefully moved to the lingula to detach the anterior sphenomandibular ligament insertion.

DISCUSSION

In case of a very short ramus, there is hypoplasia of soft tissues, especially the pterygomasseteric sling, and the stylomandibular ligaments are short. This is why it seems necessary to release the sphenomandibular ligament in all forms of ramus lengthening.

[Femoral lengthening. A critical review of ten-year results]

PURPOSE OF THE STUDY

To evaluate the results of femoral lengthening in the patients treated from 2000 to 2009 in whom complete radiographic data were available and the lengthening procedure involved mainly the use of a Mephisto fixator.

MATERIAL AND METHODS

A total of 28 femoral lengthening procedures were carried out in 26 patients,16 girls and 10 boys. The external fixator Mephisto was used in 24 cases; fixators Prospon and Orthofix in one and three cases, respectively. Fifteen patients were treated for congenital short femur, the rest had secondary femoral shortening due to following pathologies: distal femoral epiphysiolysis in five children, proximal femoral osteomyelitis in one child, avascular necrosis of the femoral head in one, diaphyseal femur fracture in one, enchondromatosis of the distal femur with growth plate destruction in one, and contralateral femur overgrowth following a fracture in one child. The average age at the beginning of treatment was 11 (range, 4-16) years. Complications were classified as mild, serious and critical. The results were statistically analysed using several statistical tests.

RESULTS

The average parameter values for the group included: total femoral lengthening, 40.2.mm (SD±11.1); osteotomy index (OI), 41 % (SD±9.8); lengthening percentage (LP), 10.9 % (SD±3.8); lengthening index (LI), 14.5 (SD±3.5) days/cm; hea- ling index (HI), 52.6 (SD±20.1) days/cm; and consolidation index (CI), 93.3 (SD±40.0) days/cm. Mild complications were recorded in 11 (39.2 %), and serious and critical in eight patients (28.6 %). Fourteen patients (53.8 %) were free of any complications. Two complications were concurrently found in five patients (17.9 %). There was a statistically significant difference in the LP values related to the number of complications (p=0.019). No significant relationship was recorded on comparison of the HI value with the patient's age at the time of surgery (p=0.836) and patient's gender (p=0.546) (Mann- Whitney test). The relationship of the OI value to the HI value was non-significant (p=0.492), as was the relationship between the osteotomy technique (oscillating or Gigli saw osteotomy) and the occurrence of complications (p=1.000) (Fisher's exact test). Correlation between the LI and HI values was significant (p<0.001).

DISCUSSION

The results of healing after lengthening, as assessed by the healing and the consolidation index, were in agreement with other authors' data. The lower number of complications, particularly fractures of bone regenerate, can be explained by the facts that, in our study, the lengthening percentage was lower and that the post-operative care was strictly observed, including dynamic axial loading which stimulates bone consolidation at the lengthened section, with adherence to the proof of three developed cortices.

CONCLUSIONS

Our results did not confirm the assumption that slower lengthening will have a favourable effect on the healing index. Key words: femoral lengthening, external fixator, complications.

[Complications after femoral lengthening with ring fixators in congenital femoral deficiency]

PURPOSE OF THE STUDY

Congenital femoral deficiency (CFD) is a rare and complex deformity. The results and complications of surgical correction of this deformity using ring fixators (Ilizarov/Taylor Spatial Frame) have been evaluated.

MATERIAL AND METHODS

We retrospectively reviewed a consecutive series of 30 patients with CFD, between the ages of 3.3 and 17 years (mean, 9.3 years), with 35 lengthening procedures. Ten cases were treated with an Ilizarov frame, 25 cases with a Taylor Spatial Frame (TSF).

RESULTS

The average lengthening at femoral osteotomy was 44.3 mm. Nine patients underwent an additional tibial lengthening by an average of 24.2 mm. The total lengthening was 50.5 mm (28-85 mm). A fracture after removal of the fixator occurred in 25.7% of the cases, and a pin-site infection with the subsequent need of operative revision was found in 8.5%. A subluxation of the knee joint was observed in 11.4% and a persistent limitation of the knee joint range of motion in 22.8%.

CONCLUSIONS

Despite several complications, the use of ring fixators, especially the TSF, is an effective method for treatment of this complex deformity. The complication rate was similar with the use of either ring fixator. Some complications can be decreased with experience. The risk of knee dislocation can be reduced by joint bridging and fractures after frame removal can be avoided by prophylactic rodding.

A review of problems, obstacles and sequelae encountered during femoral lengthening : uniplanar versus circular external fixator

There is currently a consensus regarding the superiority of circular type external fixators over uniplanar fixators for lengthening of the tibia, but femoral lengthening is still subject to the surgeon's preference. This study compares the occurrence rates of significant problems, obstacles and sequelae between these two techniques. Fifty patients (29 male, 21 female), with a mean age of 20 years were assigned to a circular type fixator group (54 lengthening segments), whereas 60 patients (29 male, 31 female), with a mean age of 20 years were assigned to a uniplanar fixator group (67 lengthening segments). The incidence of knee stiffness was significantly higher in the circular external fixator group (031 per segment) compared to the uniplanar external fixator group (0.13 per segment) (p < 0.05). The incidence of pain during lengthening was higher in the circular external fixator group, and patient satisfaction was higher in the uniplanar external fixator group. We recommend the uniplanar external fixator as a preferable device for femoral lengthening.

Pin-tract infection during limb lengthening using external fixation

We evaluated the incidence of pin-tract infection (PTI) during limb lengthening using external fixation in 88 patients and the effects of infection on final outcomes and incidence of additional procedures. The PTI rate was 96.6%. The rate of half-pin site infection was significantly (P<.05) higher in half-pin fixators (100%) than in hybrid fixators (78%). There was a significantly (P<.05) higher incidence of half-pin site infection (78%) than fine-wire site infection (33%). The rate of additional surgeries for treating PTI was higher for half-pin sites than for fine-wire sites. Three (3.4%) of the 88 cases led to chronic osteomyelitis. Careful insertion and a simple, well-defined, excellent pin-care protocol can minimize PTI.

Chronic psoas syndrome caused by the inappropriate use of a heel lift

Heel lifts are commonly recommended for patients to manage the pain and discomfort of leg length discrepancies. However, used inappropriately, orthotics can create additional pain instead of alleviating it. In the case described, a 79-year-old male physician used a recommended heel lift for a perceived leg length discrepancy after right hip arthroplasty. Six months postsurgery, chronic, intractable pain developed in his hip and groin. He underwent a battery of tests to locate the pain, but its source remained elusive. Osteopathic evaluation and radiographic examination revealed an absence of leg length discrepancy and the presence of chronic psoas syndrome. Osteopathic manipulative treatment was prescribed and heel lift therapy discontinued, and the patient reported complete remission from pain.

Long-term results of surgery for forearm deformities in patients with multiple cartilaginous exostoses

BACKGROUND

Surgical treatment of forearm deformities in patients with multiple cartilaginous exostoses remains controversial. The purpose of the present study was to determine the reasonable indications for operative treatment and to evaluate long-term results of forearm surgery in these patients.

METHODS

We retrospectively reviewed twenty-three patients (thirty-one forearms) after a mean duration of follow-up of nearly thirteen years. The mean age at the time of the initial procedure was eleven years. The patients underwent a variety of surgical procedures, including excision of exostoses; corrective procedures (lengthening of the radius or ulna and/or corrective osteotomy of the radius and/or ulna) and open reduction or excision of a dislocated radial head. Clinical evaluation involved the assessment of pain, activities of daily living, the cosmetic outcome, and the ranges of motion of the wrist, forearm, and elbow. The radiographic parameters that were assessed were ulnar variance, the radial articular angle, and carpal slip.

RESULTS

Four patients had mild pain, and five patients had mild restriction of daily activities at the time of follow-up. Eight patients stated that the appearance of the forearm was unsatisfactory. Radiographic parameters (ulnar variance, radial articular angle, carpal slip) were initially improved; however, at the time of the final follow-up visit, the deformities had again progressed and showed no significant improvement. The only procedure that was associated with complications was ulnar lengthening. Complications included nonunion (three forearms), fracture of callus at the site of lengthening (two forearms), and temporary radial nerve paresis following an ulnar distraction osteotomy (one forearm). Excision of exostoses significantly improved the range of pronation (p = 0.036).

CONCLUSIONS

In our patients with multiple cartilaginous exostoses, corrective osteotomy and/or lengthening of forearm bones was not beneficial. The most beneficial procedure was excision of exostoses. Reasonable indications for forearm surgery in these patients are (1) to improve forearm rotation and (2) to improve the appearance.

Vascular lesions secondary to osteotomy by corticotomy

Management of vascular traumas is frequently delayed. Vascular injuries after elective operation for bone lengthening or correction of a deformity are very'rare situations. We describe 3 cases. Case 1: male, aged 22, undergoing corticotomy for bone lengthening; immediately presented acute limb ischaemia due to a partial lesion of the popliteal artery, documented by U.S. After 7 h, direct reconstruction of the artery and fasciotomies were performed. Case 2: male, aged 27, undergoing directional osteotomy for genu varus correction. For 30 days, constant increase in leg volume and decrease in function. US showed an important haematoma at the popliteal level; arteriography documented a partial lesion of the infra-genicular popliteal artery and a voluminous false aneurysm. Direct correction of the artery and fasciotomies were performed. Case 3: male, aged 22, undergoing corticotomy for leg lengthening; immediately presented leg pain with decreased distal pulses. After 4h, there was an increase in leg volume, and arteriography showed a total lesion of the infra-genicular popliteal artery and an arteriovenous fistula. Popliteo-tibial bypass with the contralateral greater saphenous vein and fasciotomies were performed. After 1 month endovascular closure of the fistula was obtained. All patients had recovered after two months with only minor leg insufficiency. Patency of the bypass and absence of infections or delayed false aneurysms were achieved. Vascular injuries after elective orthopaedic procedures are very rare situations. Such lesions are caused by an osteotomy via corticotomy performed percutaneously. The variety of clinical presentations accounts for the difficulty in diagnosing such lesions and for the delays in implementing treatment. It is very important to obtain an early diagnosis complete with an arteriography.

Lateral column lengthening

The guiding principle behind the lateral column lengthening is to bring the forefoot and midfoot out of abduction while using the foot's natural bony architecture to drive the hindfoot into inversion and dorsiflexion. This correction effectively negates the loss of normal biomechanics created by the loss of the dynamic function of the posterior tibial tendon. The purpose of this article is to review the lateral column lengthening procedure through a detailed explanation of the operation, the postoperative care, and the pitfalls and complications of the procedure.

Bisphosphonate rescue in distraction osteogenesis: a case series

Distraction osteogenesis is a powerful stimulus for new bone (and tissue) generation (anabolism). Biomechanical stimulation by distraction of the regenerate region results in a high rate of tissue and bone production. However, catabolism (bone resorption) can also occur, the process potentially accentuated in a stress-shielded environment of an external fixator. Regenerate insufficiency can result in regenerate bending or fracture after frame removal. Experimental evidence has demonstrated that bisphosphonates may mediate improved local limb bone mineral density (BMD) and regenerate strength in animal models. Seven patients who had undergone limb lengthening using an Ilizarov device were found to have regenerate insufficiency. Poor regenerate quality led to consideration for intervention. With informed consent, patients received a therapeutic regime of intravenous pamidronate (n = 3) or zoledronic acid (n = 4).The mean age was 13.8 years (SD, +/-3.6 years), with a minimum follow-up period of 4 months after fixator removal. The sites of regenerate insufficiency were the proximal tibia (n = 6) and the distal femur (n = 1). The mean time interval in the fixator before bisphosphonate treatment was 170 days (range, 124-252 days), with an average length increase of 4.8 cm (SD, +/-1.1 cm). At time of intravenous bisphosphonate treatment, dual-energy x-ray absorptiometry measurements demonstrated a reduced BMD (mean, 62.1%; SD, +/-12.6%) in the bone adjacent to the lengthening site of the nonoperated side. Mean healing index was high at 79.6 days/cm (range, 64.4-108.0 days/cm), reflecting the observed regenerate insufficiency. No significant systemic complications were encountered. Six of the patient's fixators were removed without requirement for other intervention, demonstrating a rapid and sustained improvement in local BMD, increasing to a mean of 85.6% (SD, +/-13.3%) of the healthy side. One patient did not respond and subsequently healed after percutaneous osteogenic protein 1 (bone morphogenetic protein 7) and bone marrow injection. Most failed regenerate cases maintain some underlying anabolic activity and can be treated successfully with bisphosphonate therapy, which reduces catabolism. Only 1 case required percutaneous administration of an anabolic therapy to achieve union. These minimally invasive approaches may lessen the need for surgery in a group where significant surgical reintervention could otherwise be required.

The humerus is the best place for bone lengthening

The aim of this study was to examine the effectiveness of lengthening the humerus in children and young adults. Between 1984 and 2005, the Orthopaedic Department of Semmelweis University elongated 11 humeri (ten patients) for reasons of congenital hypoplasia (four cases), osteomyelitis (three cases), epiphyseolysis, growth plate closure after irradiation and obstetrical paralysis (one case each). The study cohort consisted of five females and five males, with an average age at the time of surgery of 17.8 years (range: 12-31 years). In every case, the lengthening was performed with a unilateral Wagner fixator. The lengthening protocol was 1 mm distraction daily (callotasis) after a 7-day latency period. The fixator was removed after total bone healing. Plate fixation or bone transplantation was not used. The average rate of lengthening was 6.2 cm (4.5-10.5 cm), and the achieved lengthening was 27% (range: 16-44%). The average healing index was 32 day/cm. One patient who suffered from temporary radial paresis, and temporary flexion contracture of the elbow was regarded as a complication following placement of the fixator. Based on our results, humeral shortening can effectively be treated with the unilateral Wagner fixator. The main difference between the original Wagner method and our approach is that we were able to leave the fixator in the humerus until total bony reconstruction so there was no need for plate fixation or bone transplantation.

Treatment of angular deformities of the tibia in children: acute versus gradual correction

This is a retrospective review of 25 tibial osteotomies (in 19 patients) performed with either acute or gradual correction to determine the outcome of treatment and incidence of neurovascular complications. Patients undergoing gradual correction had fewer neurovascular complications and greater correction than those undergoing acute correction (27 degrees vs. 18 degrees, respectively). It was concluded that gradual correction tends to be a safer technique for the treatment of tibial deformities and allows greater correction.

Comparison of the complication rates between first and second (repeated) lengthening in the same limb segment

The purpose of this study is to compare the incidence and types of complications in children who are undergoing first and second (repeated) lengthenings of the same bone. This is a retrospective review of 11 children (12 limbs) who underwent limb lengthenings of the same bone twice. There were 7 femoral and 5 tibial repeated lengthenings. Diagnoses included congenital femoral deficiency or proximal femoral focal deficiency in 6 patients, fibular hemimelia in 2, achondroplasia in 2, and tibial hypoplasia in 1. Mean age was 8.5 years for the first lengthening and 11.5 years for the second lengthening. There were 2.2 complications per lengthening for the first procedure and 1.5 for the second lengthening. There were 5 major and 22 minor complications for the first lengthening and 1 major and 17 minor complications for the second lengthening, none of these data were found to be statistically different. The healing index was 1.3 +/- 0.43 months per cm first lengthening and 2.2 +/- 1.7 cm for the second lengthening. This study did not demonstrate a significantly higher rate of complications with repeated lengthening of the same limb, although the time in the fixator for the second lengthening was longer and the degree of lengthening less.

Predicting the loss of knee flexion during limb lengthening using inherent muscle length

Limb lengthening procedures can be associated with loss of range of knee movement, although the amount of knee flexion lost varies markedly between patients. The exact aetiology of this problem is not fully understood. This study investigates whether the amount of joint range that is lost during limb lengthening might be affected by the inherent passive compliance and length of the patients' soft tissues determined preoperatively. A simple mathematical model has been developed to calculate the inherent length and 'spare' length of the hamstring and quadriceps muscle groups in 28 patients undergoing limb lengthening procedures. The range of knee motion was recorded preoperatively and loss of movement recorded during follow-up. The results show a strong correlation between predicted 'spare' length of quadriceps and loss of knee flexion. An association was noted between loss of knee extension and the straight leg raise and correlation of knee extension and the spare length of the hamstrings. The straight leg raise test, and calculation of spare quadriceps length using our formula, as part of the preoperative assessment, can help predict which patient is at risk of a reduced range of motion of the knee.

The effect of tibial lengthening on immature articular cartilage of the knee joint

OBJECTIVE

To investigate the acute response of immature articular cartilage, in the distraction and consolidation phases, to 30% tibial lengthening.

DESIGN

Sixteen immature New Zealand white rabbits underwent diaphyseal lengthening of the left tibia by callotasis at a distraction rate of 0.4mm twice daily. A sham control group of 12 rabbits underwent fixation and osteotomy without lengthening. In each group, half of the rabbits were killed at the end of the distraction phase or at an equivalent time period and the rest were killed after an additional 5 weeks (consolidation phase). The tibial condyles and synovial fluid in the knee joint cavity were taken for laboratory examination. Sulfated glycosaminoglycan in synovial fluid was estimated using a colorimetric method. Sections along the mid-coronal plane of the whole of the tibial condyles were examined histologically and by scanning electron microscopy. A grading system was used to make a semiquantitative assessment of the histopathological changes in articular cartilage.

RESULTS

Damage to the immature articular cartilage had occurred by the end of the distraction period and the cartilage continued to deteriorate in the consolidation phase of 5 weeks. However, when compared with a similar study in a mature rabbit model, damage to immature cartilage appeared less severe.

CONCLUSION

This model of 30% lengthening caused acute cartilage damage which did not recover in the short term. The result may have implications for longer lengthening in children; the effects may be disadvantageous and lead to degenerative diseases later in life.

No difference in tibial lengthening index by use of Taylor spatial frame or Ilizarov external fixator

BACKGROUND

Different methods and devices are used to perform lengthening and deformity reconstruction in the tibia. Recently, the Taylor spatial frame (TSF) has been introduced as a computer-assisted and versatile external ring fixator. Lengthening index (LI) and complications are important result parameters, and the aim of this study was to review our first 20 tibial segments operated with the TSF and to compare the results with our experience of using the traditional Ilizarov external fixator (IEF).

PATIENTS AND METHODS

We lengthened 20 tibial segments in 20 patients with the TSF. The results were compared with those of 27 tibial segments from 27 patients that were lengthened with the IEF. All segments were operated on with monofocal osteotomies.

RESULTS

In the overlapping zone of comparable lengthening distances between 2.4 and 6.0 cm, the LI of 2.4 and 1.8 months/cm was not significantly different between the TSF and IEF groups, respectively (p = 0.17). This non-significant difference was confirmed after adjustment for age.

INTERPRETATION

We found no difference between the TSF and IEF frames regarding LI and complication rate. However, rotational, translational, and residual deformity correction is easier to perform with the TSF.

Evans calcaneal lengthening procedure for spastic flexible flatfoot in 32 patients (46 feet) with a followup of 3 to 9 years

BACKGROUND

The purposes of this study were to evaluate the outcome of calcaneal lengthening in severe pediatric flexible flatfoot deformities of spastic origin and to determine the necessity of additional procedures.

METHODS

In a prospective study, 32 patients (46 feet) were evaluated clinically and radiologically. The mean age of patients was 11 (range 4 to 22) years. The mean period of followup was 66 (range 36 to 108) months.

RESULTS

Additional soft-tissue procedures (Strayer procedure, peroneus lengthening, reefing medial capsule) were performed in 39 of 46 feet; other bony procedures were performed in eight. Among the 46 feet, 11 outcomes were classified as excellent, 19 as good, nine as fair, and seven as poor. Poor outcome was related to overcorrection in three and deformity relapse in four. Calcaneocuboid subluxation was seen in nine feet. Radiographic evaluation demonstrated an improvement of all parameters determined.

CONCLUSION

The Evans procedure is effective for the correction of severe, flexible flatfoot deformity in children with cerebral palsy in the short and mid term. Additional soft-tissue procedures frequently are required. However, correction of this multiplanar deformity predominantly occurs in the forefoot abduction component of the deformity, and the concomitant naviculocuneiform sag remains uncorrected. Despite successful outcomes, overcorrection and undercorrection remains a problem of clinical relevance.

Tibial lengthening over an intramedullary nail

BACKGROUND

Long-term application of an external fixator to treat leg-length discrepancy and short stature often causes complications, such as pin-tract infection or loss of range of motion at the knee or ankle (or both). Prolonged fixator use also interferes with the activities of daily living. To minimize such problems, we have combined intramedullary nailing with external fixation. Using this technique, the external fixator can be removed more quickly after completing the lengthening.

METHODS

We combined intramedullary nailing with lengthening in 13 tibias (8 patients) and then compared these cases with 17 standard tibial lengthenings (16 patients) using an external fixator alone. In both groups we excluded patients who had a history of previous bone infection, open fracture, immature bone, soft tissue compromise, antineoplastic chemotherapy, or bone deformity of a severity that required gradual deformity correction. We also excluded cases with lengthening of less than 3 cm.

RESULTS

The mean external fixation index differed significantly between the two groups, but the consolidation index did not. Mean operating time for lengthening combined with intramedullary nail placement was approximately 60 min longer than for standard lengthening without nail placement; intraoperative blood loss was not greater in the nailing group. Complications related to the external fixator were far fewer in the combined intramedullary nailing and lengthening group compared with the control group, and callus formation was satisfactory for both groups.

CONCLUSIONS

A combination of intramedullary nailing and external fixation produces callus formation as good as that obtained by the standard Ilizarov method of lengthening. Furthermore, this combined procedure decreases the external fixation time and is associated with fewer complications.

Analysis of scar formation after lower limb lengthening: influence on cosmesis and patient satisfaction

Limb lengthening aims to reduce limb length discrepancy, improve cosmesis, and permit more functional mobility. Scarring, however, is a major concern of patients. In this study 25 patients (27 lengthening sites) were assessed; 6 sites were lengthened with Orthofix and 21 sites with Ilizarov. Altogether, 452 pin tract scars were assessed. The mean scar length was 11.5 mm in the Ilizarov group (n=415) and 54.1 mm in the Orthofix group (n=37). The mean scar width was 5.6 mm in the Ilizarov group and 11.5 mm in the Orthofix group. The mean patient satisfaction was 7.3 in the Orthofix group and 5.5 in the Ilizarov group. The mean Vancouver score was 0.66 in the Ilizarov group and 3.1 in the Orthofix group. The scars were shorter and cosmetically better in the Ilizarov group, but patients were more satisfied in the Orthofix group because there were fewer scars. Patients were also more satisfied with the thigh scars than with the leg scars because clothing can easily cover the thigh scars.

Femoral lengthening over an intramedullary nail using the external fixator: risk of infection and knee problems in 22 patients with a follow-up of 2 years or more

BACKGROUND

The time for femoral lengthening is shortened if external fixation is combined with intramedullary nailing. However, several complications have been reported with this procedure.

PATIENTS AND METHODS

We retrospectively reviewed the outcome of femoral lengthening performed over an intramedullary nail using external fixation in 22 patients. These patients were followed for a mean of 3.2 (2-5.2) years. The mean age was 22 (13-35) years at the time of the index procedure. The mean lengthening was 5 (2.7-8.1) cm and the external fixator was removed after median 20 (8-30) weeks. The mean external fixation index was 24 (11-35) days/cm and the mean consolidation index was 43 (26-55) days/cm of lengthening.

RESULTS

3 patients who had a past history of infection or open trauma developed osteomyelitis which required removal of the nail. There were 4 knee joint complications when the lengthening was over 20%, including posterior knee subluxation and patella subluxation. In 1 patient, the lengthened segment collapsed with breakage of locking screws.

INTERPRETATION

Although lengthening over a nail can reduce the duration of external fixation, caution is required to prevent major complications.

Treatment for flexion contracture of the knee during Ilizarov reconstruction of tibia with passive knee extension splint

Joint stiffness is one of the complications of limb procedure. It developes as a result of failure of knee flexors to lengthen in tandem with the bone, especially when there is inadequate physical therapy to provide active and passive mobilization of the affected joint. We are reporting four patients who developed fixed flexion contracture of their knees during bone lengthening procedure for the tibia with Ilizarov external fixator. Three of them were treated for congenital pseudoarthrosis and one was for fibular hemimelia. None of them were able to visit the physiotherapist even on a weekly basis. A splint was constructed from components of Ilizarov external fixator and applied on to the existing frame to passively extend the affected knee. Patients and their family members were taught to perform this exercise regularly and eventually near complete correction were achieved. With this result, we would like to recommend the use of this "Passive Knee Extension Splint" to avoid knee flexion Contracture during limb lengthening procedures with Ilizarov external fixators.

Complications encountered during lengthening over an intramedullary nail

BACKGROUND

In limb-lengthening, the quest for increased patient comfort and a reduced period of external fixation has led to techniques such as lengthening over an intramedullary nail. The goals of this study were to investigate the rate and types of complications encountered during lengthening over an intramedullary nail and to identify solutions to these complications.

METHODS

Forty-two segments (thirty-five femora and seven tibiae) in thirty-five patients were lengthened. The mean age of the patients was 26.6 years, the mean amount lengthened was 6.3 cm (range, 2.5 to 11.5 cm), the mean external fixation index was 18.7 days/cm, and the mean lengthening index was 31.2 days/cm. The patients were followed for a mean period of forty-four months postoperatively.

RESULTS

Eighteen complications occurred in sixteen (38%) of the forty-two segments for a rate of 0.43 complication per segment. Complications were classified, according to the system of Paley et al., as two problems, thirteen obstacles, and three sequelae. Sixteen of them required additional surgical interventions. A preoperative score of >6.5 on the system of Paley et al., a lengthening of >6 cm, and a lengthening percentage of >21.5% of the original bone length were indicators of a higher probability of the occurrence of complications.

CONCLUSIONS

Lengthening over an intramedullary nail provides increased patient comfort and reduces the external fixation period. If the problems encountered are treated aggressively, the result of the treatment can be quite satisfactory.

Inferior subluxation of the fibular head following tibial lengthening with a unilateral external fixator

BACKGROUND

Inferior subluxation of the proximal part of the fibula has been reported to occur with distraction osteogenesis of the tibia; however, the clinical sequelae of this subluxation are unknown. The purpose of this study was to evaluate inferior subluxation of the proximal part of the fibula and its possible clinical implications in patients who had undergone tibial lengthening by distraction osteogenesis with use of a unilateral external fixator.

METHODS

Thirty tibiae in seventeen patients with a variety of conditions underwent tibial lengthening by distraction osteogenesis with use of a unilateral external fixator and were followed clinically and radiographically for a mean of two years and ten months (range, two to four years). Ten patients were female and seven were male. Their mean age at the time of the surgery was seventeen years (range, eight to twenty-five years). The mean tibial lengthening was 8.1 cm (range, 3.5 to 13 cm).

RESULTS

An inferior shift of the fibular head in relation to the tibia was evident in all cases. The shift, which ranged from 0.4 to 3.3 cm, was proportionally related to the amount of tibial lengthening. This type of subluxation is probably attributable to the tension that is exerted by the intact interosseous membrane during the distraction as well as to the tension of the regenerated bone of the fibula and the fact that the fibula itself is not fixed or directly lengthened by the external fixator.

CONCLUSIONS

It appears that inferior subluxation of the fibula is a common phenomenon in patients undergoing tibial lengthening by distraction osteogenesis with use of a unilateral external fixator. However, no clinical symptoms or findings related to the inferior subluxation of the fibula were found in our series.

Virtual reality as a pediatric pain modulation technique: a case study

Post-surgical pain has been consistently reported in pediatrics as being difficult to manage and limiting to surgical outcomes. Pain management of children is not ideal, and some children unable to tolerate traditional pharmacological agents. Virtual reality (VR) is a new and promising form of non-pharmacologic analgesia. This case study explored the use of VR analgesia with a 16-year-old patient with cerebral palsy participating in a twice-daily physiotherapy program following Single Event Multi-Level Surgery. Over 6 days, the patient spent half of his physiotherapy sessions using VR and the other half without (order randomized). Traditional pharmacological pain management was administered throughout the trial. Using a subjective pain scale (five faces denoting levels of pain), the patient's overall pain ratings whilst in the VR (experimental) condition were 41.2% less than those in the no-VR (control) condition. This case report provides the first evidence that VR may serve as a powerful non-pharmacologic analgesic for children following surgery.

[Relationship between tibia callus diameter ratio and prognosis during tibia lengthening]

OBJECTIVE

To investigate the relationship between the tibia callus diameter ratio (CDR) and prognosis during tibial distraction and the occurrence of late deformity or fracture.

METHODS

We measured tibial lengthening callus diameter and added up the cases of angular deformity and fracture in 68 cases from January 1996 to December 2001, to calculated callus diameter ratios and compare the relationship between the tibia callus diameter during tibial distraction and the occurrence of late callus angular deformity or fracture.

RESULTS

In 23 cases of CDR < 80%, 13 cases had new bone fracture, 21 cases had angular deformity > 5 degree. In 6 cases of 81% < CDR < 85%, there were 4 cases of angular deformity > 5 degree. In the other 39 cases of CDR > 85%, there were no fracture and angular deformity.

CONCLUSION

When the CDR was > 85%, there were no angular deformity and fracture, but when the CDR was < 80%, the complications of fracture and angular deformity occur. CDR is a better alarming index for preventing the complications occurring in tibial lengthening.

Biomechanical consequences of lateral column lengthening of the calcaneus: Part I. Long plantar ligament strain

Lateral column lengthening of the calcaneus has been a powerful tool used to correct peritalar subluxation in symptomatic flat feet. The mechanical basis and limits for correction with this procedure are not well understood. A flatfoot model was created on 8 fresh-frozen cadaver feet by sectioning the deltoid ligament, talonavicular capsule, and spring ligament. Strain-gauge analysis of the long plantar ligament was performed (on 6 specimens) as the lateral column was sequentially lengthened from 4 to 12 mm in 2-mm increments. Results showed that only the lateral most one-third of the long plantar ligament measured positive strain during this procedure. The medial two-thirds of the long plantar ligament and plantar fascia decreased in tension and became fully lax during lengthening. Maximum tension in the long plantar ligament was measured after placing grafts 6 mm in thickness (P <.05). Larger grafts produced additional strain in the ligament, but were not significant. The authors conclude that grafts >6 mm have no additional corrective capacity without compromising the long plantar ligament. Either larger graft size or loss of the long plantar ligament could compromise the intrinsic stability of the lateral column of the foot. These findings may decrease the incidence of complications with this procedure, specifically lateral column pain, instability, and calcaneocuboid arthrosis.

Nerve lesions associated with limb-lengthening

BACKGROUND

Nerve injury is one of the most serious complications associated with limb-lengthening. We examined the risk, assessment, and treatment of nerve lesions associated with limb-lengthening.

METHODS

We retrospectively studied the records on 814 limb-lengthening procedures. Nerve lesions were defined by clinical signs and symptoms of motor function impairment, sensory alterations, referred pain in the distribution of an affected nerve, and/or positive results of quantitative sensory testing with use of a pressure specified sensory device.

RESULTS

Seventy-six (9.3%) of the limbs had a nerve lesion. Eighty-four percent of the nerve lesions occurred during gradual distraction, and 16% occurred immediately following surgery. The pressure specified sensory device showed 100% sensitivity and 86% specificity in the detection of nerve injuries. The patients in whom the lesion was diagnosed with this method, or with this method as well as with nerve conduction studies, had significantly faster recovery than did those diagnosed on the basis of clinical symptoms or nerve conduction studies alone (p = 0.02). Patients undergoing double-level tibial lengthening and those with skeletal dysplasia were at higher risk for nerve lesions (77% and 48%, respectively). Nerve decompression was performed in fifty-three cases (70%). The time between the diagnosis and the surgical decompression was strongly associated with the time to recovery (p = 0.0005). Complete clinical recovery was achieved in seventy-four of the seventy-six cases.

CONCLUSIONS

Early detection based on signs and symptoms or testing with a pressure specified sensory device improves the prognosis for nerve injury that occurs during limb-lengthening. Of the methods that we used to identify neurologic compromise, testing with the pressure specified sensory device was the most sensitive. Aggressive early treatment (slowing the rate of lengthening and/or performing decompression) allows continued lengthening without incurring permanent nerve injury. When indicated, decompression of the affected nerve should be performed as soon as possible, thereby improving the chances of and shortening the time to complete recovery.

Quadricepsplasty for knee stiffness after femoral lengthening in congenital short femur

We review the results of a modified quadricepsplasty in five children who developed stiffness of the knee after femoral lengthening for congenital short femur using an Ilizarov external fixator which spanned the knee. All had a full range of movement of the knee before lengthening was undertaken. Unifocal lengthening was carried out in the distal metaphysiodiaphyseal region of the distal femur with a mean gain of 6.5 cm. The mean percentage lengthening was 24%. At the end of one year after removal of the Ilizarov frame and despite intensive physiotherapy all patients had stiffness. Physiotherapy was continued after the quadricepsplasty and, at the latest follow-up (mean 27 months), the mean active flexion was 102 degrees (80 to 130). The gain in movement ranged from 50 degrees to 100 degrees. One patient had a superficial wound infection which settled after a course of oral antibiotics. None developed an increased extension lag after surgery and all were very satisfied with the results. Quadricepsplasty is a useful procedure for stiffness of the knee after femoral lengthening which has not responded to physiotherapy.

Acute changes in the axonal cytoskeleton after mild stretching of the rat brachial plexus

We have developed an animal model to investigate acute changes in the axonal cytoskeleton caused by a mild stretching of the peripheral nerve in the upper limbs of rats. Rat forelimbs were continuously stretched at 2 N for 1 h. Thereafter, a part of the brachial plexus and median nerve were harvested and processed for electron microscopic analysis. The total number of microtubules in the brachial plexus decreased to 55% of that of the control animals (p<0.05) without change in the number of neurofilaments. No significant changes in microtubules or neurofilaments were observed in the median nerve. By Western blotting analysis, the amount of tau protein in the stretch group significantly decreased in the brachial plexus but not in the median nerve. However, no significant changes in the amount of tubulin protein were observed in either the brachial plexus or median nerve. These results suggest that the microtubules were depolymerized by stretching of the brachial plexus and that the depolymerization may have been mediated by the decrease in the tau protein.

Histomorphometry of distraction osteogenesis during experimental tibial lengthening

OBJECTIVES

The aim of the current study was to analyze distraction osteogenesis histomorphometrically to investigate the amount of enchondral ossification adjacent to intramembranous ossification.

STUDY DESIGN

Species-specific, longitudinal time study. METHODS Lengthening of 25% of the right tibia was performed in 24 beagle dogs by callus distraction after osteotomy and application of a ring fixator. Distraction was started at the fifth postoperative day with a distraction rate of 0.5 mm twice a day. Twelve dogs were killed at the end of the distraction phase of 25 days (group A) and the remaining 12 dogs after an additional consolidation period of 25 days (group B). The tibia was removed from the distracted right leg and from the left control side of each animal, and longitudinal sections were cut and stained with Pentachrome. In all tibiae, an area of 0.5 x 2.4 cm within the endosteal bone was evaluated histomorphometrically with a Merz grid, and the results were compared between distraction and control side as well as between the dogs of group A and group B.

RESULTS

On the distraction side, the typical signs of an increased de novo bone formation with a significant increase of osteoblasts and osteoid in group A, as well as an additional significant increase of bone volume and trabecular thickness in group B, were found. In all distraction cases, islands of cartilage formation, which underwent enchondral ossification, were found, besides membranous ossification. The ratio between membranous and enchondral ossification was found to be five to one.

CONCLUSION

Bone formation during distraction osteogenesis results from both membranous and enchondral ossification.

Paranodal demyelination by gradual nerve stretch can be repaired by elongation of internodes

Nerve elongation resulting from leg-lengthening surgery can be injurious. We investigated peripheral nerve injury and recovery after gradual elongation of the rat sciatic nerve by progressive stretching. Indirect nerve elongation was produced by leg lengthening by 15 mm, at a rate of 3 mm/day (group I) or 5 mm/day (group II). The elongated length was then maintained. At 0 weeks, representing the 7th day after starting leg lengthening, and at weeks 2, 4, and 6, transverse semithin sections of sciatic nerve were examined. At the same time a teased fiber study was performed. As a result of nerve elongation axon diameter was decreased, although it later recovered. Axon diameter recovered more slowly in group II than I. Myelin thickness did not change compared with controls. In the teased fiber study, internodal length was increased by about 10% after nerve elongation in each group. Almost all nerve fibers showed demyelination at 0 weeks; myelination recovered with time, more slowly in group II than I. More obvious demyelination, axonal degeneration, and remyelination were observed in group II. We conclude that mild demyelination was repaired by elongation of internodes, while more severe demyelination was repaired by intercalation of segments.

Spontaneous bone regeneration in surgically induced bone defects in young rabbits

Defects of the femoral shaft (15%, 20%, 25%, and 30% of the femoral length) with intact periosteum were made in young rabbits to investigate differences in union time. The mean union time was 7.3, 7.1, 7.4, and 7.0 weeks, respectively and there was no significant difference ( >0.05) between the groups. The mean healing indices were 6.7, 4.6, 3.9, and 3.1 weeks/cm, respectively and these were significantly different ( <0.05) between the 15% bone defect group and the other bone defect groups. These results suggested that union time was not affected by the amount of bone defect. Femoral lengthening of 20% was performed to compare the quality of callus with those of the femoral defect of 20%. The mean healing indices of defect and lengthening were 4.6 and 5.7, respectively and the difference was significant ( = 0.004). The callus stiffness of femoral defect was higher ( = 0.02) than that after femoral lengthening whereas the bone mineral density of the callus showed no significant difference ( = 0.37) between two groups. The method of filling bone defect with callus generated from the intact periosteum may be a new therapeutic option for the reconstruction of large bone defects in children when other treatments are not available.

Tibial lengthening: does the fibula migrate?

A retrospective study of 32 patients who underwent tibial lengthening was performed in order to establish the need for distal tibio-fibular fixation. In 16 patients stabilization of the inferior tibio-fibular joint was carried out and in the other 16 no stabilization was performed. Three established and one new radiographic index of the tibio-fibular relationship at the ankle were used to assess proximal fibular migration. All patients showed proximal migration of the distal fibula, but those without stabilization demonstrated marked migration of the fibula associated with a valgus tendency. The difference between the groups was statistically significant ( <0.001), confirming the need for fibular fixation.

Pathogenesis of the gradually elongated nerve

The rabbits' sciatic nerves were lengthened by 30 mm in increments of 2.0 mm/day (2-mm group) and 4.0 mm/day (4-mm group). In the 2-mm group, the phosphorylated neurofilament (p-NF) immunoreactivity of axons was similar to that of the control group. However, in the 4-mm group, number of p-NF positive axons decreased. The number of p-NF positive cells at the seventh lumbar dorsal root ganglion cells of the 4-mm group was significantly larger than that of the control group. Abnormal p-NF immunoreactivity in the 4-mm group suggested an impairment of the axonal flow. Leakage of Evans blue-albumin into the endoneurial space, which meant destruction of the blood-nerve barrier function, was clearly evident in the 4-mm group, but minor in the 2-mm group. A speed of 2.0 mm/day, therefore, appears to be critical for safe nerve elongation in this model.

Experimental study on slow-speed elongation injury of the peripheral nerve: electrophysiological and histological changes

Slow-speed elongation of the sciatic nerves was induced in 41 rabbits by lengthening the osteotomized femur by 2.1 mm/day with an external fixator. Time courses were monitored. About 2 weeks after elongation began, the amplitude of the compound nerve action potentials decreased, and delayed latency began. Histological observations showed that the wavy structure of the nerve fibers was lost during the stage at which reduction in the amplitude of action potentials occurred. In some nerve fibers, narrowing of the axons was observed. Further elongation caused delay in the percent latency. Histologically, collagen fibers were noted in the nerve fascicles, as well as narrowing in all the nerve fibers. When elongation ceased at the stage at which a reduction in the amplitude of action potential was noted, recovery from nerve damage followed. When elongation did not cease until the stage at which latency was delayed, however, recovery was not apparent, either histologically or electrophysiologically. The critical level of percent amplitude for recovery was at 82.4% of the original level (the critical rate for bone lengthening was 20.5%).

Fracture stiffness in callotasis determined by dual-energy X-ray absorptiometry scanning

Assessing healing after distraction limb lengthening is essential to manage patients undergoing callotasis for leg lengthening or bone transport. Direct measurement of fracture stiffness can assess healing but the equipment may not be available. In addition, it requires removal of the fixator, which may be complicated for ring fixators. The present study investigates whether an equivalent measure of healing can be based on the mineral density pattern from dual-energy X-ray absorptiometry (DXA) scans. Nine consecutive patients undergoing callotasis were studied. Bending stiffness of the distraction segment was measured and DXA scans were performed regularly starting 6 weeks after completing distraction. In all, 23 simultaneous readings of bending stiffness and DXA scans were obtained. All density patterns showed a distinct minimum value of bone mineral density. We found a high and significant correlation between fracture bending stiffness and the square of the total mineral content at the location of minimum bone density (r2 = 0.77, P < 0.001). We conclude that DXA scans can be used reliably and effectively to determine fracture bending stiffness, valuable for determining both time of frame removal and delay in union.

Vulnerability of the gradually elongated nerve to compression injury

The purpose of this study is to clarify the vulnerability of the gradually elongated peripheral nerve. Rabbit's sciatic nerves were gradually elongated to 30 mm at the rate of 2.0 mm/day and 4.0 mm/day. Immediately after elongation, the sciatic nerve was exposed and compressed for 30 minutes at various forces, 15, 30 and 60 g/0.1 cm(2). Immediately after elongation and compression, 2, 4 and 8 weeks after compression, each group was electrophysiologically and histologically estimated--15 g/0.1 cm(2) caused no damage to the control group, neurapraxia to the 2.0 mm/day group, and axonotmesis to the 4.0 mm/day group; 30 g/0.1 cm(2) caused neurapraxia to the control group and axonotmesis to the 2.0 mm/day group; 60 g/0.1 cm(2) caused axonotmesis to the control group and slowly recovered axonotmesis to the 2.0 mm/day group. This study shows that though mild compression, does not cause nerve injury to the intact nerve, it can sometimes cause severe damage to the gradual elongated nerve.

Limb lengthening in short stature patients

A series of 140 patients with short stature operated on for limb lengthening (80 had achondroplasia, 20 had hypochondroplasia, 20 had Turner syndrome, 10 had idiopathic short stature due to an undemonstrated cause, 5 regarded their stature as too short, and 5 had a psychopathic personality due to dysmorphophobia that had developed because of their short stature) was reviewed. All patients underwent symmetric lengthening of both femora and tibiae; 10 of these achondroplastic patients underwent lengthening of the humeri. We carried out the 580 lengthening procedures by means of three different surgical techniques: 440 callotasis, 120 chondrodiatasis and 20 mid-shaft osteotomy. In the 130 patients with a disproportionate short stature, the average gain in length was 18.2 +/- 3.93 cm: 43.8% had complications and 3.8% had sequelae; the average treatment time was 31 months. In the 10 patients with proportionate short stature, the average gain in length was 10.8 +/- 1.00 cm: 4 experienced complications and none had sequelae; the average treatment time was 21 months. Patients who underwent lengthening of the upper limbs experienced an average gain in length of 10.2 +/- 1.25 cm: the average treatment time was 9 months and none of them experienced any complications or sequelae. The authors discuss how difficult it is to achieve the benefits of this surgery: they underline the strong commitment on the part of the patients and their families, the time in the hospital, the number of operations and, above all, the severity of those permanent sequelae that occurred.