[Preliminary study of Ilizarov technique in treatment of lower limb deformity caused by achondroplasia].

Objective: To investigate the surgical method and preliminary effectiveness of Ilizarov technique in the treatment of lower limb deformity caused by achondroplasia. Methods: The clinical data of 38 patients with lower limb deformity caused by achondroplasia treated by Ilizarov technique between February 2014 and September 2021 were retrospectively analyzed. There were 18 males and 20 females, the age ranged from 7 to 34 years, with an average of 14.8 years. All patients presented with bilateral knee varus deformity. The preoperative varus angles was (15.2±4.2)°, and knee society score (KSS) was 61.8±7.2. Nine of these patients underwent tibia and fibula osteotomy, 29 cases underwent tibia and fibula osteotomy and bone lengthening at the same time. Full-length bearing position X-ray films of bilateral lower limbs were taken to measure the bilateral varus angles, analyze the healing index, and record the occurrence of complications. KSS score was used to evaluate the improvement of knee joint function before and after operation. Results: All 38 cases were followed up 9-65 months, with an average of 26.3 months. Needle tract infection occurred in 4 cases and needle tract loosening occurred in 2 cases after operation, which were improved after symptomatic treatment such as dressing change, Kirschner wire change, and oral antibiotics, and no neurovascular injury occurred in all patients. The external fixator was worn for 3-11 months after operation, with an average of 7.6 months, and the healing index was 43-59 d/cm, with an average of 50.3 d/cm. At last follow-up, the leg was 3-10 cm longer, with an average of 5.5 cm. The varus angles was (1.5±0.2)° and the KSS score was 93.7±2.6, which significantly improved when compared with those before operation ( P<0.05). Conclusion: Ilizarov technique is a safe and effective method for the treatment of short limb with genu varus deformity caused by achondroplasia, which can improve the quality of life of patients.

[Clinical characteristics analysis of 22 062 patients of foot and ankle deformity from QIN Sihe Orthopaedic Surgery Database between May 25, 1978 and December 31, 2020].

Objective: Based on the clinical data of patients with foot and ankle deformities in the QIN Sihe Orthopaedic Surgery Database, to analyze the characteristics and treatment strategies of foot and ankle deformities, and provide a basis for clinical decision-making. Methods: A total of 22 062 patients with foot and ankle deformities who received orthopedic surgery between May 25, 1978 and December 31, 2020 were searched in the QIN Sihe Orthopedic Surgery Database. The gender, age at operation, regional distribution, etiology, type of deformity, operation method, postoperative fixation method, and other information were collected. Results: Among the 22 062 patients, there were 13 046 males (59.13%) and 9 016 females (40.87%); the age at operation ranged from 1 to 77 years, with a median of 17 years, and 20 026 cases (90.77%) were aged 5 to 40 years. The patients came from 32 provinces, municipalities, and autonomous regions across the China and 5 countries including India and the United States, et al. The etiology and diseases type covered 154 kinds (of which sequelae of poliomyelitis, cerebral palsy, spina bifida and tethered spinal cord, congenital equinovarus foot, post-traumatic foot and ankle deformity, and Charcot-Marie-Tooth disease accounted for the highest proportion). The types of deformities included varus foot, equinus foot, valgus foot, talipes calcaneus, equinocavus, high arched foot, claw toe, and flail foot. Surgical methods included tendon lengthening, soft tissue release, tendon transposition, osteotomy orthopedics, and ankle arthrodesis. The 36 620 operations were performed, including 11 561 cases of hip, knee, and lower leg operations to correct the foot and ankle deformities. Postoperative fixation methods included Ilizarov external fixator in 2 709 cases (12.28%), combined external fixator in 3 966 cases (17.98%), and plaster or brace fixation in 15 387 cases (69.74%). Conclusion: Male patients with foot and ankle deformities account for a large proportion, and the population distribution is mainly adolescents, with a wide distribution of regions, causes and diseases, and talipes equinovarus and varus foot are the main types of deformities. Foot and ankle deformities are often combined with deformities of other parts of the lower limb, which requires a holistic treatment concept. The application of foot soft tissue and bone surgery combined with Ilizarov external fixator and combined external fixators provides a guarantee for the correction of complex foot and ankle deformities.

Identification of TUL01101: A Novel Potent and Selective JAK1 Inhibitor for the Treatment of Rheumatoid Arthritis.

Janus kinase 1 (JAK1) is a potential target for the treatment of rheumatoid arthritis (RA). In this study, the introduction of a spiro ring with a difluoro-substituted cyclopropionamide resulted in the identification of TUL01101 (compound 36) based on a triazolo[1,5-a]pyridine core of filgotinib. It showed excellent potency on JAK1 with an IC50 value of 3 nM and exhibited more than 12-fold selectivity for JAK2 and TYK2. Whole blood assay also demonstrated the high activity and selectivity (37-fold for JAK2). At the same time, TUL01101 also demonstrated excellent metabolic stability and pharmacokinetics (PK) profiles were assayed in three species (mouse, rat, and dog). Moreover, it has been validated for effective activity in the treatment of RA both in collagen-induced arthritis (CIA) and adjuvant-induced arthritis (AIA) models, with low dose and low toxicity. Now, TUL01101 has progressed into phase I clinical trials.

[Analysis on the characteristics of 837 patients with post-traumatic lower limb deformities from QIN Sihe Orthopaedic Surgery Database between May 25, 1978 and December 31, 2020].

Objective: To summarize and analyze the characteristics and treatment strategies of post-traumatic lower limb deformity based on QIN Sihe Orthopaedic Surgery Database. Methods: A clinical data of 837 patients with post-traumatic lower limb deformities treated by orthopaedic surgery between May 25, 1978 and December 31, 2020 in QIN Sihe Orthopaedic Surgery Database were analyzed retrospectively. The information of the patient's gender, age at the time of surgery, region of origin, cause of trauma, deformity side, orthopedic surgery related information (operation time, location, type, and fixation method after operation) were summarized and analyzed. Results: All patients came from 32 provinces, municipalities, autonomous regions, and Taiwan in China. Among them, 551 cases (65.83%) were male and 286 cases (34.17%) were female. The age of the patients at the time of surgery was 3-84 years old, with an average of 27.6 years old, and the most patients were 16-45 years old (559 cases, 66.78%). The main cause of trauma was traffic accident injury (639 cases, 76.34%). The deformity mainly involved unilateral limbs, including 394 cases (47.07%) on the left side and 376 cases (44.92%) on the right side. The most patients were admitted between 2008 and 2017, accounting for 53.05% (444/837). All patients were operated on one or more sites (1 048 sites), among which ankle and toe surgery were the most, accounting for 48.38% (507/1 048). The patients received 1204 surgeries including tendon lengthening and soft tissue contracture release, et al. Orthopedic surgery combined with bone external fixation was used in 624 cases (467 cases of Ilizarov external fixation and 157 cases of combined external fixation), and plaster or brace external fixation was used in 213 cases. Conclusion: Post-traumatic lower extremity deformity patients have a large proportion of males, with a wide geographical distribution, involving various parts of the lower extremities, and most commonly in the foot and ankle. Orthopedic surgery combined with bone external fixation (Ilizarov technique) is the main methods for correction and functional reconstruction of post-traumatic lower limb deformity.

Synthesis and evaluation of hydrazinyl-containing pyrrolo[2,3-d]pyrimidine series as potent, selective and oral JAK1 inhibitors for the treatment of rheumatoid arthritis.

Selective inhibition of JAK kinases within the JAK family has been a desired goal of research in order to maximize efficacy while reducing undesired off target effect. Aiming to minimize adverse effects such as anemia, a promising new class of pyrrolo[2,3-d]pyrimidine series containing a hydrazinyl moiety were synthesized and profiled. Among them compound 8m and 8o showed the best enzymatic activity against JAK1 with IC50 value of 0.16 nM and 0.3 nM respectively, and with selectivity over JAK2 by 40.6 and 10 folds respectively. In addition, 8o had an improved PK profile and demonstrated better in vivo efficacy than Tofacitinib in CIA model.

Optical Sensor Assistant with Voltage Enrichment for Ultrasensitive Detection of Mercury Ions.

Voltage enrichment-assisted surface-enhanced resonance Raman scattering (SERRS) was employed for monitoring mercury(II) ions based on a nanoporous gold (NPG)/aptamer hybrid sensor. The hybrid sensor based on the coordination chemistry of thymine-Hg2+-thymine interaction and an applied voltage that pushed mercury ions toward the NPG film improved both the speed and sensitivity of Hg2+ ion detection. The detection limit can reach 0.1 pM, even in the aqueous solution containing 13 metal ions, and the sensor also possesses a fine reproducibility and stability, promising great potential in real-time sensing applications.

[Effectiveness of minimally invasive osteotomy Ilizarov technique combined with intramedullary nail for femoral lengthening].

Objective: To explore the effectiveness of minimally invasive osteotomy Ilizarov technique combined with intramedullary nail for femoral lengthening. Methods: Seventy-one patients with femoral shortening deformity who met the selection criteria between January 2013 and June 2016 were randomly divided into trial group (36 cases were treated with minimally invasive osteotomy Ilizarov technique combined with intramedullary nail for femoral lengthening) and control group (35 cases were treated with simple Ilizarov technique for femoral lengthening). There was no significant difference in age, gender, causes of femoral shortening, length of femoral shortening, rate of femoral deformity between the two groups ( P>0.05). The operation duration, intraoperative blood loss, lengthening rate, external fixation duration, frequency of pin tract infection, osteotomy healing time, and range of motion (ROM) of knee at 1 year after operation were recorded and compared between the two groups. Results: The patients of two groups were followed up 12-60 months (mean, 31 months). Pin tract infection occured in 8 cases (10 pins), including 1 case (1 pin) in the trial group and 7 cases (9 pins) in the control group. There was significant difference in the incidence of pin tract infection between the two groups ( χ2=5.265, P=0.022). All patients were cured by replacing the fixation pins, changing dressing actively, application of antibiotics, and adequate postoperative care. The operation duration, intraoperative blood loss, external fixation duration, osteotomy healing time, and ROM of knee at 1 year after operation of the trial group were superior to those of the control group, showing significant differences ( P<0.05). There was no significant difference in the lengthening rate between the two groups ( t=-1.581, P=0.153). Conclusion: The minimally invasive osteotomy Ilizarov technique combined with intramedullary nail in femoral lengthening increases the operation time, but the external fixation duration and incidence of pin tract infection are significantly reduced and the function of knee is significantly improved.

[Data analysis of 8 113 cases of limb deformities corrected by external fixation].

Objective: To analyze the data of external fixation instruments (including Ilizarov instruments) used by QIN Sihe orthopaedic surgical team in the treatment of limb deformities in the past 30 years, and to explore the indications for the application of modern external fixation techniques in the correction of limb deformities and individual device configuration selection strategy. Methods: According to QIN Sihe orthopaedic surgical team, the use of external fixator between January 1988 and December 2017 was analyzed retrospectively. The total use of external fixation and the proportion of different external fixators were analyzed in gender, different operation time, different age, different parts, and different diseases. Results: External fixators were used in 8 113 patients, 69 of them were used simultaneously in both lower extremity surgery, so 8 182 external fixators were used. Among them, there were 4 725 (57.74%) combined external fixators, 3 388 (41.41%) Ilizarov circle fixators, 64 (0.78%) single arm external fixators (including Orthofix), 5 (0.06%) Taylor space external fixators. There were 4 487 males (55.31%) and 3 626 females (44.69%). According to the analysis of different time periods, the number of external fixators increased year by year, and the number of applications increased after 2000. The main age of the patients was 11-30 years old, of which 1 819 sets (22.23%) were used at the age of 21-25 years. The use of the external fixator covered almost all parts of the limbs, with the ankle and toe areas being the most common, reaching 4 664 sets (57.00%), and the upper extremities the least, with 152 sets (1.86%). The 8 113 cases covered more than a dozen disciplines and more than 150 kinds of diseases. The top 5 diseases were poliomyelitis sequelae, cerebral palsy, deformity of lower extremity after spina bifida, traumatic sequelae, and congenital equinovarus foot. Conclusion: Ilizarov technique has been widely used in extremity deformity, disability, and complicated orthopedic diseases caused by vascular, lymphoid, nerve, skin, endocrine, and other diseases. The indication of operation is far beyond the scope of orthopedics. The domestic external fixator and its mounting tools can basically meet the requirements of various treatments. The technique of external fixation has entered a new era of tension tissue regeneration under stress control, natural repair of tissue trauma and deformity, and reconstruction of limb function.

[Limited orthopaedic surgery combined with external fixation for the treatment of lower extremity sequelae of middle and old aged post-poliomyelitis].

Objective: To summarize the effectiveness of limited orthopedic surgery combined with external fixation for the treatment of lower extremity sequelae of middle and old aged post-poliomyelitis, and then to explore the strategy of surgical correction and functional reconstruction method. Methods: From the database of 23 310 cases of poliomyelitis sequelae treated by QIN Sihe Orthopaedic Surgical team between September 1982 and December 2017, 629 patients over 41 years old were retrieved and the epidemiological characteristics of the patients were analyzed. Between March 2011 and June 2015, 57 patients with poliomyelitis sequelae treated with limited operation and external fixation were followed up 2-6 years, and the history of poliomyelitis sequelae was 41-67 years (mean, 47.1 years). Preoperative histopathological gait included 29 cases of quadriceps gait, 17 cases of walking with crutch, and 11 cases of claudication only. The operative methods included Achilles tendon lengthening in 52 cases, supracondylar osteotomy in 39 cases, knee flexion release in 36 cases, calcaneal arthrodesis in 27 cases, flexion and hip arthrodesis in 21 cases, tibia and fibula osteotomy in 19 cases, triple arthrodesis in 11 cases, and tendon transposition in 1 case. After operation, 18 cases were treated with combined external fixator and 39 cases with Ilizarov ring external fixator. Results: Of the 629 cases, 481 cases were less than 50 years old (76.47%), accounting for 144 cases between 51 and 65 years old (22.89%). Among them, 495 cases (78.70%) were diagnosed after 2003. Of the 57 patients obtained complete follow-up information, 7 had slight infection of needle path during traction orthopaedics, 2 had early postoperative venous thrombosis of lower extremities, and 2 had incomplete paralysis of the common peroneal nerve. There was no complications such as skin incision infection, vascular injury, and bone nonunion. According to the evaluation standard of postoperative efficacy standard in correction of lower extremity deformities, the results were excellent in 23 cases, good in 20 cases, fair in 12 cases, and poor in 2 cases, with an excellent and good rate of 75.44%. The 2 patients with poor effectiveness were reoperated to improve their function. Conclusion: Limited orthopedic surgery combined with external fixation for the treatment of lower extremity sequelae of middle and old aged post-poliomyelitis can effectively correct deformities of lower limbs, improve function, delay the disability aggravated by decay, and avoid serious complications.

[Ilizarov TECHNOLOGY COMBINED WITH TARSAL V-SHAPE OSTEOTOMY FOR TREATMENT OF TRAUMATIC CLUBFOOT].

OBJECTIVE: To discuss the effectiveness of Ilizarov technology combined with tarsal V-shape osteotomy for the treatment of traumatic clubfoot. METHODS: Between August 2011 and August 2014, 14 patients with traumatic clubfoot were treated. There were 10 males and 4 females, aged 13 to 61 years (mean, 31 years). of 14 cases, 11 had open fractures of the tibia and ankle and 3 had closed fracture of the ankle joint. The interval from trauma to operation was 7-78 months (mean, 36 months). The plantar flexion of the ankle was 44-89° (mean, 57°). After invasive foot soft tissue release and tarsal V-shape osteotomy, the Ilizaroy external fixator with elastic stretching rod was used. At 5-12 weeks after operation, the neutra pos ofthe ankle joint was restored. Then the neutral position of the ankle joint was maintained for 8 to 12 weeks. After removal of external fixator, protective walking brace was used for 8 to 12 weeks. RESULTS: Infection occurred in 9 cases, and was cured after symptomatic treatment. The patients were followed up 10-36 months (mean, 15 months). After treatment, 14 patients had normal appearance of the ankle joint, and X-ray films showed normal structure of the ankle. The ankle dorsal extension was 10° in 9 patients, who had normal walking function; it was 5° in 4 patients, who could walk; in 1 case of neutral position, the foot had no function of up and down stairs. One case had pain during correction because of poor tolerance, and delay traction was given, the function was recovered to normal after active rehabilitation training. According to the International Clubfoot Study Group (ICFSG) score standard, the results were excellent in 9 cases, good in 4 cases, and fair in 1 case; the excellent and good rate was 92.9% at last follow-up. CONCLUSION: Ilizarov external fixation combined with V-shape osteotomy is effective for the treatment of traumatic clubfoot, with the advantages of less trauma, reliable fixation, satisfactory correction of the deformity, and good function recovery of the ankle.

[Combined procedure for the treatment of ankle and foot deformities secondary to spina bifida].

OBJECTIVE: To study surgical strategies for ankle and foot deformities secondary to spina bifida and treatment methods for different types of deformities. METHODS: From January 1990 and July 2009, 107 patients with ankle and foot deformities secondary to spina bifida were retrospectively analyzed. There were 44 males and 63 females, with an average age of 17.7 years (rangd from 1.3 to 52 years). Among the patients, 58 patients had double ankle deformities, 49 patients had unilateral deformities (22 cases on the left side, 27 cases on the right). Ninety-nine patients with equinus deformities were treated by achilles tendon lengthening and tendon transfering; 25 patients with talipes were treated by release of anterior tendon of ankle and tendon transfer; 17 patients with valgus and varus deformities were treated by tendon transfer and calcaneal osteotomy; 15 patients with flail deformities were managed treated by bone fusion between calcaneus and talus and shortening of achilles tendon; 9 patients with claw toe deformities were treated by bone fusion of interphalangeal joint or Ilizarovs distraction. AOFAS (American Orthopaedic Foot & Ankle Society) comprehensive scoring system was used to evaluate subjective pain and objective functional. RESULTS: Seventy-nine (127 feet) of 107 patients were followed up, and the duration ranged from 48 to 180 months (averaged, 64 months). According to AOFAS scoring system, the results were rated as excellent in 89 feet, good in 26 feet, moderate in 9 feet and poor in 3 feet. CONCLUSION: Treatment strategies for ankle-foot deformities mainly included four principles, deformity correction, muscular balance, joint stability and reservation of foot elasticity. Different combined procedure was applied for different foot deformities and received good therapeutic effects.

[Limited operations and Ilizarov technique for correction of congenital clubfoot in adolescents].

OBJECTIVE: To observe the effectiveness of limited operations and Ilizarov techniques for correction of congenital clubfoot (CCF) in adolescents, and to explore the new methods and new ideas for functional reconstruction of CCF. METHODS: Between September 2003 and July 2010, 25 adolescent patients (40 feet) with CCF were treated. Of the 25 patients, 14 were male (20 feet) and 11 were female (20 feet) with an age range from 12 to 25 years (mean, 15.7 years). The left feet were involved in 4 cases, the right feet in 6 cases, and both feet in 15 cases. According to Qin's clubfoot deformity scale, 9 feet were rated as degree I, 17 feet as degree II, and 14 feet as degree III. In these cases, 9 feet were accompanied by internal rotation deformities of crus and 1 case by subluxation of right hip joint. After soft tissue release and osteotomy, 9 feet (degree I) were fixed by composite external fixation instruments, 31 feet by Ilizarov external fixation instruments. The deformity was corrected from 5 to 7 days after operation with distraction of 0.5-1.0 mm/d, then distraction stopped when the ankle was corrected at a hyperextension of 5 to 100 and light valgus. The affected limb might undergo weight bearing walking with external fixation at corrected position for 4 to 6 weeks. If one had both feet deformity, staged operation should be performed with a surgery interval of 3 to 6 months (mean, 4 months). RESULTS: The fixation time was 6-12 weeks (mean, 8 weeks) in 9 feet fixed by composite external fixation instruments, and it was 6-17 weeks (mean, 13 weeks) in 31 feet fixed by Ilizarov external fixation. Ml 25 patients were followed up 8 months to 6 years with an average of 37 months. During distraction process, slight pin track infection occurred in 6 cases (6 feet), which were cured after expectant management. One patient had recurrence of the deformity at 2 years postoperatively, who obtained satisfactory correction after Ilizarov external fixation for 4 weeks. The satisfactory correction and foot function were achieved in the other feet with walking on full weight-bearing. According to International Clubfoot Study Group (ICFSG) score, the results were excellent in 28 feet, good in 10 feet, and fair in 2 feet, with an excellent and good rate of 95% at last follow-up. CONCLUSION: Combined limited operation with Ilizarov technique for correcting adolescent CCF is accord with biology principle and minimally invasive surgical principle, so it is a safe, minimally invasive, and effective method. It also can broaden the operative indications and correct degree III talipes equinovarus which is unattainable by traditional orthopedic surgery.

[Limited internal fixation combined with external fixation for the treatment of deformity of the distal end of femur].

OBJECTIVE: To study therapeutic effects of limited internal fixation combined with external fixation in the treatment of deformity of distal end of femur, as well as to explore its effect on the function of knee joint. METHODS: From June 2004 to June 2009, 38 patients with deformity of distal end of femur were treated with osteotomy at femoral supracondylar and internalfixation combined with hybrid external fixator. Among the patients, 19 patients were male and 19 patients were female, ranging in age from 14 to 58 years, with an average of 26 years. Six patients had genu valgum, 4 patients had varus of the distal end of femur, 2 patients had varus combined with rotation deformity,3 patients had genu recurvation and 23 patients had deformity of genuflex. The function of knee joint was evaluated according to Dimeglio clinical assessment after the treatment. RESULTS: All the patients were followed up and the during ranged from 6 to 48 months, with a mean period of 23 months. All the deformity obtained satisfactory correction, without complications such as limitation of motion of the knee joint, under correction or over correction,displacement of the section of the osteotomy,internal fixation loosening and fracture. Nineteen patients got an excellent result, 12 good, 5 poor and 2 bad. CONCLUSION: Supracondylar femoral osteotomy and internal fixation combined with hybrid external fixator is a safe and effective surgery for the treatment of deformity of distal end of femur. This method combines the advantages of internal fixation and external fixation.

[Mini-invasive distraction technique for treatment of severe ankle and foot deformities secondary to ischemic contracture of the leg].

OBJECTIVE: To explore the Ilizarov mini-invasive distraction technique for the treatment of severer ankle and foot deformities secondary to ischemic contracture of the leg. METHODS: Based on the tension-stress low of Ilizarov, a serial of adjustable three dimensions external distractive instrument was developed in our department. From April 2002 to March 2004, 8 patients with ankle and foot deformities secondary to ischemic contracture of the leg induced by trauma and fracture were treated with the distractive instrument. Of them, 4 patient were male and 4 female, aged from 13 to 31 years with an average of 23 years. Five affected legs were in the left and 3 in the right. Preoperative abnormal style included talipes equines in 6 feet and equinovarus in 2 feet, with extensive scar contracture in the legs. Five patients suffered from failure of soft tissue release before, two patients with severe bony deformity of the feet were underwent limited foot triple osteotomy in this department before the distractive correction. The distraction was begun from 7 d after operation and distractive time from 29 to 60 d with an average 46 d. RESULTS: All of the 8 patients were followed up from 10 months to 29 months, with an average of 13 months. All of deformities in the feet were corrected satisfactorily, full feet contacted with the ground in stand or walking and achieved with good function. No complication, such as pin tract infection, skin necrosis and neurovascular injury was occurred in this group. CONCLUSIONS: Mini-invasive distraction technique for treatment of severe ankle and foot deformity secondary to ischemic contracture of the leg is safe and mini-injury, it is also an effective approach for the treatment of various kinds of rigid foot anomaly.

[The design and application of synchronized springy lengthening apparatus for the tibia and tendo calcaneus].

OBJECTIVE: To study the role of the synchronized springy lengthening apparatus for the tibia and calcaneal tendon designed by the author in preventing the clubfoot of secondary to the Ilizarov tibia lengthening. METHODS: Based on the Ilizarov tibia lengthening apparatus, a special synchronized springy lengthening apparatus for the tibia and calcaneal tendon was designed. The tibial was made of distal and proximal 2 rings respectively and 4 threaded rods, and the calcaneal was made of a half ring, 2 hinges and a threaded rod with spring. The half ring was fixed to the calcaneus by 2 crossed wires. The fracture tibia and fibula, ankle joint, talocalcaneal joint were attached to the apparatus. At the same time of tibia lengthening, the soft tissue was simultaneously stretched, the ankle joint could move, and the leg could bear weight. If the clubfoot angle was larger, the percutaneous fasciotomy of calcaneal tendon was performed; if the angle was less than 20 degrees, the pes deformities were corrected only by the stretch of calcaneal tendon. RESULTS: Seventy-seven patients' tibia were lengthened averagely 4.6 cm, with an average speed of 0.7 mm/d. The healing made tibia lengthened, and the index was 1.35 months/cm. There were not the secondary varus and valgus deformities and clubfoot in all the patients. The clubfoot with 100-400 angle of the 16 patients were corrected after tibia lengthening. CONCLUSIONS: The new apparatus coincides with the biomechanical principle and can effectively prevent the secondary deformities of foot such as clubfoot, talipes varus and valgus after tibia lengthening procedure.

[Ilizarov technique for correcting flexion deformity of the knee of arthrogryposis multiplex congenita].

OBJECTIVE: To study the methods and effects of Ilizarov distraction technique in treating the flexion deformity of the knee of arthrogryposis multiplex congenita. METHODS: Between August 1998 and February 2003, 6 patients (10 knees) with the arthrogryposis multiplex congenita were treated, 4 patients in double knees, 5 males, 1 female, mean age 8 years and 2 months, ranged from 3 years and 7 months to 13 years. The preoperative flexion degree was averagely 51 degrees. The patients accompanied 13 other parts malformation of limbs. The modified Ilizarov distraction apparatus of the knee was used. While installing the apparatus in the operation, the knees should be kept in the of location of maximum extension, the center of joint hinges on the apparatus should be placed towards the rotatory center of the knee, two groups of 2 mm K-wires were passed through the femur and tibia around the knee, who were fixed on the proximal and distal rings. Distraction was started after the surgical procedure 5 days via rotating the threaded rods at the posterior of the knee, at an average of 2 to 3 mm per day, at the first week, after 2 weeks with the rate modified to 2 mm per day, up to the knee extended to 0 degrees. The accompanied deformities of the hip and/or the foot might be corrected at the same time or next time. The average duration of the distraction was 37 days (23-48 days). During the correction all limbs might undergo weight. After 2 weeks at the end of distraction the fixator was removed and the patients could walk by a long-leg brace. RESULTS: Ten knees with the flexion contracture were sufficiently corrected without severe complications. Nine knees of all were followed up at an average time of 1 years and 3 mouths, no recurrence of the deformity was seen in all patients, their function of walk was significantly improved. CONCLUSIONS: Ilizarov technique is a simply, safe and effective method for managing the flexion deformity of the knee of the arthrogryposis multiplex congentia. The procedure is conformable to the biological theories and microsurgical principles.