Is human height based on a Lucas sequence relationship between the foot height, tibial length, femur length and upper body length?

This is a retrospective chart and radiographic review of 145 patients who underwent full-body EOS imaging; 109 males and 36 females. The mean ages of the female and male subsets are 28.8 (SD = 11.6) years and 29.5 (SD = 11.8) years, respectively. The sum of the foot height (Ft) and the tibial length (T) for each subject was compared to their femur length (Fe). Subsequently, the sum of the tibial (T) and femoral lengths (Fe) were compared to their respective upper body lengths (UB), as measured from the tops of the femoral heads. A linear regression test was performed to determine whether a Lucas sequence-based relationship exists between Ft + T and Fe, and between T + Fe and UB. The regression for the relationship between Ft + T and Fe for the entire cohort (R = 0.82, R2 = 0.70), the female subset (R = 0.94, R2 = 0.88) and the male subset (R = 0.75, R2 = 0.57), all demonstrated a strong positive correlation between Ft + T and Fe and showed that Ft + T is a likely predictor of Fe. The regression test for the entire cohort demonstrated a moderately positive correlation between T + Fe and UB (R = 0.41, R2 = 0.17, F(1, 145) = 29.42, p = 2.4E-07). A stronger correlation was found for the relationship between T + Fe and UB (R = 0.57, R2 = 0.32, F(1, 35) = 16.64, p = 2.5E-05) for the female subset relative to the male subset (R = 0.20, R2 = 0.038, F(1, 35) = 4.37, p = 0.04). There appears to be a Lucas sequence relationship between the lengths of the foot height, tibial length, femoral length and upper body length, which together make up standing height. This mathematical proportion relationship is stronger in females than males.

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

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

Modified Langenskiöld procedure for congenital patella dislocations in pediatric patients.

BACKGROUND: Great difficulty and more failures were the descriptions of the treatment of congenital patella dislocation in pediatric patients. This study aims to evaluate the outcomes of patients with congenital patellar dislocations treated with the modified Langenskiöld procedure. METHODS: The medical records of 16 knees in 11 patients with a diagnosis of congenital patella dislocation were collected from September 2016 to March 2019. They were treated with the modified Langenskiöld procedure. The mean follow-up period was 37.8 months. The outcome measures were the Lysholm score, Kujala score, patellar stability, and knee range of motion. RESULTS: Eleven patients, namely, eight girls and three boys, with 16 knees were enrolled. The mean age at the time of operation was 3.1 years. The post-operative mean Lysholm score was 94.8 (SD 5.1; 87-100), whereas the Kujala score was 95 (SD 5.9; 86-100). There were no recurrent dislocations, and all patients had full extension postoperatively. CONCLUSION: The modified Langenskiöld procedure is a promising solution for the treatment of congenital patella dislocations. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment Study.

Combination Treatment by Cross-Union of the Tibia and Fibula, Autogenic Iliac Bone Grafting, Reliable Fixation and Bone Morphogenetic Proteins for the Treatment of Refractory Congenital Pseudarthrosis of the Tibia.

BACKGROUND: The treatment of congenital pseudarthrosis of the tibia (CPT) remains a challenge because of the difficulties of achieving and maintaining bone union, as well as complications of joint deformity and limb-length discrepancy. The purpose of this study was to evaluate the efficacy of cross-union of the tibia and fibula in achieving union and preventing refracture for patients with refractory CPT as a complementary approach to improve upon conventional surgical treatments. METHODS: A retrospective study including patients with refractory CPT who attended our department between June 2014 and August 2020. Eighteen CPT patients, who had sustained refracture that required cast immobilization or secondary surgery, and were managed by pseudarthrosis resection, cross-union of the tibia and fibula, bone morphogenetic protein-2 and autogenous iliac bone grafting, were included. Clinical outcomes of the bone union rate and the frequency of refracture after performing cross-union of the tibia and fibula were assessed during the follow-up period. RESULTS: The mean follow-up period was 4.3 years (range: 1.5 to 6.25 y). The mean age of the patients at surgery was 5.4 years (range: 2.6 to 10 y), and all 18 (100%) of the 18 patients had final healing at the site of pseudarthrosis. The average time spent to achieve radiologic bone union of the pseudarthrosis after operation was 2.96 months (range: 2.2 to 4.1 mo). Two (11.1%) patients had an average 2.5 cm limb-length discrepancy, none (0%) sustained refracture which needed cast immobilization or secondary surgery. Patients were all pain-free and move actively. CONCLUSIONS: Cross-union of the tibia and fibula is a promising complementary procedure for treating refractory CPT patients. LEVEL OF EVIDENCE: Level IV-case series.

Simultaneous Limb Lengthening With Ankle Fusion Using an Internal Lengthening Nail.

We reviewed 18 limbs in 17 patients who underwent ankle fusion with simultaneous tibial lengthening with a magnetic internal lengthening nail. All patients had preoperative limb length discrepancy (LLD) (mean 4.9 cm (2.6-7.6 cm)) with ankle deformity. The ankle was fused from medial or lateral approaches using screws/plate constructs placed adjacent to the retrograde Precise nail. Lengthening was carried out by a distal 1/3 tibial osteotomy. Clinical and radiographic measures were performed after a mean follow-up of 20 months (12-37 months). The mean amount of lengthening performed was 4 cm (1.8-7.2 cm). The final mean LLD was 1 cm (0.7-1.1 cm), which was statistically significant (p<0.01) as compared to preoperative. The foot was plantigrade in all cases. The mean foot rotation was 10° (5-15°) external, relative to the knee. At final follow-up all patients reported minimal to no pain, and all claimed to be walking more functionally than before surgery. Ankle fusion and limb lengthening was achieved in all cases. Combining both treatments by using an internal lengthening nail was very effective and avoided leaving patients with a dysfunctional LLD or of having a separate limb lengthening procedure. This is the first report of such a combined treatment of ankle fusion with internal tibial lengthening nail.

Anatomic Relationship of the Femoral Neurovascular Bundle in Patients With Congenital Femoral Deficiency.

BACKGROUND: Congenital femoral deficiency (CFD) is a rare condition that affects the morphology of the hip and surrounding soft tissues. Bony deformity and distorted muscular anatomy are well known, but no studies have described the relationship of the femoral neurovascular (NV) bundle to surgically relevant anatomic landmarks. The authors compared the location of the femoral NV bundle on the affected side in patients with CFD with the unaffected side. The authors hypothesized that the bundle on the pathologic side would be in an abnormal position relative to the unaffected side. METHODS: Thirty-three patients diagnosed with unilateral CFD who had undergone preoperative magnetic resonance imaging of the pelvis were included in our study. The authors identified the femoral NV bundle on the axial cuts and measured its distance from the anterior superior iliac spine (ASIS), anterior inferior iliac spine (AIIS), and lesser trochanter (LT). Anatomic percent change and absolute measurements were then compared and correlated with associated boney deformities and the Paley classification. RESULTS: The distance from the femoral NV bundle to the ASIS, AIIS, and LT was significantly different compared with the unaffected side. The AIIS absolute distance and AIIS percent change significantly correlated with the neck-shaft angle of the proximal femur. CONCLUSIONS: In patients with CFD, the femoral NV bundle seems to be further from the LT and closer to the AIIS on the affected side when compared with the unaffected side. magnetic resonance imaging may be helpful to understand the course of the femoral NV bundle before reconstruction in patients with CFD; however, the authors recommend identification of the femoral NV bundle before transection of the proximal rectus femoris tendon to provide safe surgical care. LEVEL OF EVIDENCE: Level IV-case-control study of diagnostic studies.

Iliac crest apophysis transfer to treat stump overgrowth after limb amputation in children: case series and literature review.

PURPOSE: Stump overgrowth is the main problem of limb amputation in children. Many surgical procedures have been developed to overcome the problem, but all have shown inconsistent results. The only surgical procedure that has been successful in preventing overgrowth is capping of the amputated limb with a cartilaginous cap taken from the amputated limb, usually from the head of fibula. A donor site is not available in revision cases. Iliac crest apophysis transfer was suggested to treat the condition, but has never been previously reported. The purpose of this study is to review the results of iliac crest apophysis transfer to prevent stump overgrowth. METHOD: Five children with amputation stump overgrowth underwent iliac apophyseal transfer to cap the resection site of the overgrowth. RESULTS: Retrospective review showed that three of the five suffered recurrent stump overgrowth two to four years after the index surgery. All three were revised again. One patient was lost to follow-up. CONCLUSION: Although many studies showed capping of the stump with cartilaginous cap to be successful in preventing stump overgrowth, iliac crest apophysis transfer was only successful in one of four cases available to follow-up (25%). This is not a reliable enough method to be used routinely.

Prophylactic Intramedullary Rodding Following Femoral Lengthening in Congenital Deficiency of the Femur.

INTRODUCTION: Femoral fracture after lengthening of congenital femoral deficiency (CFD) is a common complication with a high incidence, up to 50%. The purpose of this study is to determine whether prophylactic intramedullary Rush rodding after lengthening for CFD is an effective method to prevent femoral fracture and to assess any complications that may result. METHODS: Forty-five femoral lengthenings (43 CFD patients) were performed using external fixation. At the time of frame removal (except for 3 cases, 8 d later), prophylactic intramedullary Rush rods were inserted. Special reaming techniques were developed to pass a Rush rod through the solid regenerate bone and past sclerotic pin sites. Mean age at time of rodding was 6.9 years (range, 2.9 to 14.2 y). Mean duration of treatment with external fixation was 184 days (range, 146 to 461 d). Mean follow-up was 4.2 years (range, 1.3 to 8.2 y). This group of cases was compared with a historical cohort of 95 femoral lengthening procedures for CFD without prophylactic intramedullary rodding after frame removal previously performed at the same institute by the same surgeons. RESULTS: Eight cases (18%) developed fracture despite intramedullary rodding (1 case with relatively high-energy trauma, 3 cases during physical therapy, and 4 cases spontaneously). Only 4 of these fractures required intervention. Fractures were more common when a 3.18 mm Rush rod was used (28%) compared with 4.76 mm (8.3%). Patients with prophylactic rodding had a significantly lower incidence of femur fracture rodding than those who did not (18% vs. 34%, respectively; P=0.04). Three out of 45 Rush rods (7%) developed infection that were treated by debridement and removal of the rod, and all healed uneventfully without residual or recurrent infection. There were no cases of avascular necrosis. CONCLUSIONS: Prophylactic intramedullary rodding is a safe and effective method to prevent femoral fractures after CFD lengthening. Use of 4.76 mm rod is preferred. The risk of infection is acceptable, when compared with the risk of fracture, loss of length, and angulation. LEVEL OF EVIDENCE: Level III-a retrospective comparative study.

Muscle strength and knee range of motion after femoral lengthening.

Background and purpose - Femoral lengthening may result in decrease in knee range of motion (ROM) and quadriceps and hamstring muscle weakness. We evaluated preoperative and postoperative knee ROM, hamstring muscle strength, and quadriceps muscle strength in a diverse group of patients undergoing femoral lengthening. We hypothesized that lengthening would not result in a significant change in knee ROM or muscle strength. Patients and methods - This prospective study of 48 patients (mean age 27 (9-60) years) compared ROM and muscle strength before and after femoral lengthening. Patient age, amount of lengthening, percent lengthening, level of osteotomy, fixation time, and method of lengthening were also evaluated regarding knee ROM and strength. The average length of follow-up was 2.9 (2.0-4.7) years. Results - Mean amount of lengthening was 5.2 (2.4-11.0) cm. The difference between preoperative and final knee flexion ROM was 2° for the overall group. Congenital shortening cases lost an average of 5% or 6° of terminal knee flexion, developmental cases lost an average of 3% or 4°, and posttraumatic cases regained all motion. The difference in quadriceps strength at 45° preoperatively and after lengthening was not statistically or clinically significant (2.7 Nm; p = 0.06). Age, amount of lengthening, percent lengthening, osteotomy level, fixation time, and lengthening method had no statistically significant influence on knee ROM or quadriceps strength at final follow-up. Interpretation - Most variables had no effect on ROM or strength, and higher age did not appear to be a limiting factor for femoral lengthening. Patients with congenital causes were most affected in terms of knee flexion.

Hip stability during lengthening in children with congenital femoral deficiency.

BACKGROUND: Congenital femoral deficiency (CFD) is one of the most challenging and complex conditions for limb lengthening. We focused on the problem of hip instability during femoral lengthening because subluxation and dislocation are potentially catastrophic for hip function. METHODS: We assessed for hip stability in 69 children (91 femoral lengthenings) who had CFD Paley type 1a (43 children) and 1b (26 children). The mean age at first lengthening was 6.4 years. RESULTS: Hip subluxation/dislocation occurred during 14 (15 %) of 91 lengthenings. Thirty-three pelvic osteotomies were performed before lengthening in an attempt to stabilize hips. Thirteen patients (type 1a, eight; type 1b, five) had acetabular dysplasia at initiation of lengthening. One of the eight with type 1a experienced mild femoral head subluxation; four of the five with type 1b experienced three dislocations and one subluxation. Eight patients (type 1b) experienced hip instability although they had pelvic osteotomies. Proximal femoral lengthening was a significant factor for hip subluxation. Patients with hip subluxation more likely underwent monolateral fixation and the original superhip procedure. Age ±six years was not a contributing factor for hip instability. CONCLUSIONS: Important risk factors for hip instability during femoral lengthening are severity of CFD, residual acetabular dysplasia, and proximal femoral lengthening. We recommend routine performance of pelvic osteotomy for patients with Paley type 1b CFD and distal lengthening. LEVEL OF EVIDENCE: Therapeutic Level IV.

Lengthening With External Fixation Is Effective in Congenital Femoral Deficiency.

BACKGROUND: Treatment of congenital femoral deficiency is a complex, multistage protocol and a variety of strategies have been devised to address joint instability, limb length inequality, and deformities. Despite being an important part of the algorithmic approach to the overall treatment of patients with congenital femoral deficiency, a reproducible, safe, and functional treatment for femoral length discrepancy in patients with mild and moderate congenital femoral deficiency has not been reported. QUESTIONS/PURPOSES: (1) Does femoral lengthening by means of distraction osteogenesis, using a monolateral external fixator, result in effective lengthening without loss of hip or knee range of motion? (2) Does femoral lengthening cause an inhibition of femoral growth in patients with congenital femoral deficiency? (3) Do patients/families report satisfactory functional and emotional outcomes after undergoing femoral lengthening? (4) What proportion of patients develops complications after femoral lengthening with this technique? METHODS: Between 2005 and 2009, we evaluated 38 patients for femoral length discrepancy secondary to unilateral congenital femoral deficiency. Thirty-two patients completed treatment with distraction osteogenesis using a monolateral external fixator; general indications for this approach were congenital femoral deficiency Paley Types 1a, 1b, or 2a that had not previously undergone lengthening and had stable hip and knee joints. Of the 32 patients that completed treatment, 30 (94%) were available at a minimum of 2 years (mean, 3 years; range, 2-4.5 years) and were evaluated in this retrospective study. Preoperative and postoperative radiographic analysis, physiotherapy data, patient-based outcomes scores, and complications were reviewed for all eligible patients. Growth inhibition was measured using serial radiographs over the 2-year followup with the unaffected limb considered the norm. Functional and emotional outcomes were reported by adolescent patients or parents of younger children using the Pediatric Orthopaedic Society of North America Pediatric Outcomes Data Collection Instruments (PODCI), a validated patient-based outcomes measure. RESULTS: The mean distal femoral lengthening was 6 cm (SD ± 2 cm; range, 1.6-9 cm), for a mean percent of femoral length discrepancy correction of 112% (SD ± 55%; range, 15%-215%). Comparison of patient preoperative with postoperative mean hip and knee flexion and extension showed no difference with the numbers available (hip flexion: p = 0.219, mean difference of -5, 95% confidence interval [CI], 10, SD = 20; hip extension: p = 0.423, mean difference of -1, 95% CI, 2, SD = 5; knee flexion: mean difference of -7°, SD ± 29°, CI, 15, p = 0.467; knee extension: mean difference of -1°, SD ± 9°, CI, 4, p = 0.757). A comparison of the mean preoperative inhibition of 41% (range, -38% to 300%; SD ± 72; 95% CI, 29%) with the mean postoperative inhibition of 16% (range, -242% to 100%; SD ± 61%; 95% CI, 25%) for a mean postoperative stimulation of 25% (p = 0.055, SD ± 90%; 95% CI, 36%). In all six PODCI categories surveyed, patients had favorable standardized and normative scores, but patients who underwent femoral lengthening greater than 6 cm had both lower global functioning scores (90, SD ± 10 versus 96, SD ± 3, p = 0.043) and worse pain/comfort scores (79, SD ± 25 versus 96, SD ± 7, p = 0.029), and patients who had mean percent femoral lengthening greater than 25% of initial femur length had worse pain/comfort scores (79, SD ± 23 versus 97, SD ± 4, p = 0.012) with similar global functioning scores (90, SD ± 9 versus 96, SD ± 3, p = 0.058). The total number of postsurgical complications was 30 in 60 planned surgical procedures (50%). CONCLUSIONS: Our study results support the use of the described surgical technique for femoral lengthening in treating patients with congenital femoral deficiency. Additional studies are needed both to follow long-term patient-reported outcome measures, especially after a second or third lengthening, and to determine the effect of serial lengthening on the stimulation or inhibition of growth and rate of complications. LEVEL OF EVIDENCE: Level IV, therapeutic study.

A comparative study of the correction of femoral deformity between the Ilizarov apparatus and Ortho-SUV Frame.

PURPOSES: This study compared the six-axis external fixator Ortho-SUV Frame (OSF) and the Ilizarov apparatus (IA) in femoral deformity correction. Our specific questions were: (1) which of the fixators (OSF or IA) provides shorter period of femoral deformity correction, and (2) which of the fixators (OSF or IA) provides better accuracy of correction. METHODS: We retrospectively analysed 123 cases of femoral deformities (127 femora): 45 (47) treated with OSF (20 male and 27 female) and 78 (80) with IA (53 male and 27 female). The average age in the OSF group was 34.6 (range, 18-66) and in the IA group 35.8 (range, 18-76). All the deformities were categorized according to the number of planes and deformity components as simple, middle and complex deformities. RESULTS: Elimination of simple deformities in the IA group took 58.3 ± 21.4 days, EFI 58.8 ± 39.8 days/cm, and lengthening was 4.6 ± 1.98 cm. Middle deformities were 71.3 ± 26.2, 61.9 ± 30.3 and 4 ± 2, respectively. In complex deformities we had 105.2 ± 21.8, 79.3 ± 35.4 and 3.2 ± 1.45, respectively. Normal alignment was achieved in 55.0% of cases in IA. In 45.0% of cases we had residual deformity. Elimination of simple deformations in the OSF group took 55.3 ± 12.8 days, EFI 47.5 ± 23 days/cm, and lengthening 4.5 ± 1.1 сm. Middle deformities were 43.6 ± 18.9, 59 ± 14.6 and 3.6 ± 2, respectively. In complex deformities we had 44.9 ± 11.5, 57.5 ± 9.4 and 3.6 ± 1.7, respectively. In the OSF group normal alignment was achieved in 85.1%. In 14.9% there was residual deformity. CONCLUSION: Using OSF simplifies deformity correction and reduces its period by 2.3 times in complex deformities and by 1.6 times in middle deformities. Accuracy of correction with OSF was significantly higher than correction with IA.

Rotational Guided Growth: A Preliminary Study of Its Use in Children.

Torsional malalignment of the legs is common in children, and those that do not remodel may benefit from surgical correction. Traditionally, this is corrected with an open osteotomy. Guided growth is the gold standard for minimally invasive angular correction and has been investigated for use in torsional deformities. This study presents our preliminary results of rotationally guided growth in the femur and tibia using a novel technique of peripheral flexible tethers. A total of 8 bones in 5 patients were treated with flexible tethers consisting of separated halves of a hinge plate (Orthopediatrics Pega Medical, Montreal, QC, Canada), which were fixed to the epiphysis and metaphysis at 45° angles to the physis and connected with Fibertape (Arthrex, Naples, FL, USA). The implants are placed medially and laterally in the opposite 45° inclination, determined by the desired direction of rotation. Additionally, the average treatment time was 12 months. All patients corrected the rotational malalignment by clinical evaluation. The average rotational change was 30° in the femurs and 9.5° in the tibias. Further, the average follow-up was 18 months, with no recurrence of the rotational deformity. There was no change in longitudinal growth in the patients who underwent bilateral treatment. Rotational guided growth with flexible tether devices is a novel technique that successfully corrects torsional malalignment without invasive osteotomy surgery.

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

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

Extensive Limb Lengthening for Achondroplasia and Hypochondroplasia.

Extensive limb lengthening (ELL) was completed in 75 patients: 66 achondroplasia and 9 hypochondroplasia. The average lengthening was 27 cm for achondroplasia (12-40 cm) and 17 cm for hypochondroplasia (range 10-25 cm). There were 48 females and 27 males. Lengthening was done either by 2-segment (14 patients; both tibias and/or both femurs) or by 4-segment lengthenings (64 patients; both femurs and tibias at the same time). Most patients also had bilateral humeral lengthening. Patients had 2 or 3 lower limb lengthenings and one humeral lengthening. Lengthenings were either juvenile-onset (31), adolescent-onset (38) or adult-onset (6). The average age at final follow-up was 26 years old (range 17-43 years). There were few permanent sequelae of complications. The most serious was one paraparesis. All patients returned to activities of normal living and only one was made worse by the surgery (paraparesis). This is the first study to show that ELL can lead to an increase of height into the normal height range. Previous studies showed mean increases of height of up to 20 cm, while this study consistently showed an average increase of 30 cm (range 15-40 cm) for juvenile-onset and mean increase of 26 cm (range 15-30 cm) for adolescent-onset. This results in low normal height at skeletal maturity for males and females. The adult-onset had a mean increase of 16.8 (range 12-22 cm). This long-term follow-up study shows that ELL can be done safely even with large lengthenings and that 4-segment lengthening may offer advantages over 2-segment lengthening. While all but the more recent cases were performed using external fixation, implantable limb lengthening promises to be an excellent alternative and perhaps an improvement.

Deformity Reconstruction Surgery for Tibial Hemimelia.

Tibial hemimelia is a rare congenital deficiency with a wide spectrum of pathology and deformity. This paper aims to give a comprehensive review of tibial hemimelia, with a concise summary of the history, pathology, and clinical findings of tibial hemimelia, while providing treatment recommendations and a review of the current literature. Classifications and surgical treatments are discussed, including amputation, limb reconstruction, and lengthening. Type-specific treatments are also discussed, including staged distraction correction of joint contractures of knee and ankle, Weber patelloplasty, fibular centralization, knee and ankle arthrodesis, implantable articulated distractors, and the role of femoral shortening. Amputation is a simpler and easier solution for many patients; however, reconstruction options continue to evolve, improve, and provide better functional outcomes in many cases. Factors favoring surgical reconstruction include the presence of a knee joint/proximal tibia, and the presence of a patella and quadriceps mechanism.

Reconstruction of the Hip in Multiple Hereditary Exostoses.

The hip joint involvement in multiple hereditary exostoses (MHE) occurs in 30-90%, causing pain and limitation of motion by femoroacetabular impingement, coxa valga, acetabular dysplasia, hip joint subluxation, and osteoarthritis. The purpose of this study was to investigate the clinical and radiographic outcomes of ten hips in seven patients treated by surgical dislocation and corrective osteotomies between 2004 and 2009. Surgical dislocation and excision of the osteochondromas and varus intertrochanteric osteotomies were performed in all cases when the neck-shaft angle was > 150°. Common sites of osteochondromas were medial, posterior, and anterior neck of the femur. Neck-shaft angle of the femur was improved from a mean of 157° to 139°, postoperatively. On an average, the center-edge angle improved from 20° to 30° postoperatively. We believe that Ganz's safe surgical dislocation technique is the preferred treatment of MHE. This safeguards the circulation of the femoral head and the osteochondromas can be resected under direct vision. It can be combined with additional corrective osteotomies because the hip affected by MHE is frequently associated with dysplastic changes which can result in premature osteoarthritis.

Rotationplasty for Severe Congenital Femoral Deficiency.

Rotationplasty is a reconstructive option for severe congenital femoral deficiency (CFD). The senior author (D.P.) developed five new rotationplasty techniques for use in CFD based on the Paley classification, including the Paley-Brown (fusion femur to pelvis), Paley (fusion femur to femoral head), Paley-Winkelman (insertion tibial condyle to acetabulum), PaleySUPERhip-Van Nes (hip osteotomy with knee fusion) and PaleySling-Van Nes (hip reconstruction with knee fusion revision) rotationplasty techniques. The purpose of this study is to retrospectively evaluate the complications, radiographic outcomes and need for secondary surgery in 19 rotationplasty cases performed by the senior author (D.P.) for severe CFD from 2009 to 2019. Rotationplasty comprised only 2% of the authors treated CFD cases during this period. Average age at surgery was 8.6 years old. Average follow-up was 3.3 years. Sixteen concomitant procedures were performed including temporary arthrodesis, tibial osteotomy and SUPERhip procedure. The most common complication was wound necrosis/dehiscence, which occurred in 52% of the cases related to the circumferential incision and required a total of 31 additional debridements. Additional complications were successfully treated and included sciatic nerve palsy decompressed by abducting the femur, a tibial delayed union that underwent bone grafting, two distal femur failed epiphysiodesis treated by revision with one osteotomy and a thigh compartment syndrome requiring debridement. Indication specific rotationplasty successfully addresses the severe degree of femoral deficiency, deformity, and discrepancy in patients with CFD, despite high rates of wound complications.

Cross-Union Surgery for Congenital Pseudarthrosis of the Tibia.

Congenital Pseudoarthrosis of the Tibia (CPT) is a rare condition with a reputation for recurrent fractures and failure to achieve union. A large variety of surgical procedures have been attempted for the treatment of fractured cases of CPT with an average rate of union without refracture of only 50%. Intentional cross-union between the tibia and fibula has been reported to improve these results to 100% union with no refractures. This is a retrospective study of 39 cases of CPT in 36 patients treated by the Paley cross-union protocol with internal fixation, bone grafting, zoledronic acid infusion and bone morphogenic protein 2 (BMP2) insertion. All 39 cases of CPT united at the tibia and developed a cross-union to the fibula. Two patients had a persistent fibular pseudarthrosis, one that was later treated at the time of planned rod exchange and one that has remained asymptomatic. There were few postoperative complications. There were no refractures during the up to 7-year follow-up period. The most common problem was the Fassier-Duval (FD) rod pulling through the proximal or distal physis into the metaphysis (66.7%). This did not negatively affect the results and was remedied at the time of the planned rod exchange. The Paley Cross-Union Protocol is very technically demanding, but the results have radically changed the prognosis of this once sinister disease.