Limb reconstruction has emerged as a unique and increasingly important discipline in modern medicine. Limb reconstruction refers to the systematic restoration of complex pathological conditions resulting from various injuries or diseases-such as tissue defects, infections, and deformities-using a combination of surgical and non-surgical approaches. Its technical framework is primarily based on microsurgery, the Ilizarov technique, cement-induced membrane technique (Masquelet technique), engineered tissue regeneration, soft tissue balancing and dynamic reconstruction, and modern prosthetics, supplemented by other surgical modalities including internal and external fixation, joint replacement, sports medicine, and wound management. Limb reconstruction surgery employs these techniques to systematically restore the structure, morphology, and function of the limb, representing a critical component of modern surgery. This discipline overcomes the fragmentation inherent in traditional subspecialty care, providing a definitive clinical pathway for limb reconstruction and serving as the last beacon of hope for salvaging damaged limbs.

With the rapid development of limb reconstruction surgery, which is powered by classic external fixation and Ilizarov techniques, a large number of related terms and professional jargon have been widely used. To promote the standardized development and academic exchanges of this emerging sub-discipline of orthopedics, this article systematically reviews and analyzes the key technologies and terms that are relatively unified and frequently used in the fields of external fixation and limb reconstruction. The aim is to provide standardized terminology references for relevant scholars and clinicians, and to contribute to the construction of the discipline system.

Objective:To explore the effectiveness of QIN Sihe's surgical strategy combined with Ilizarov technique in treating foot and ankle deformities on the verge of amputation. Methods:A retrospective analysis was conducted on the clinical data of 56 patients (62 feet) with foot and ankle deformities on the verge of amputation treated with QIN Sihe's surgical strategy and Ilizarov technique between May 2010 and December 2020. Among them, there were 39 males and 17 females. The age ranged from 8 to 62 years (median, 27.5 years). QIN Sihe's surgical strategy: subcutaneous release or open lengthening of contracted Achilles tendons, limited correction of bony deformities through multiple osteotomies during surgery, tendon transfer to balance the power of the foot and ankle, simultaneous percutaneous osteotomy and correction of tibial torsion deformity to restore the weight-bearing line of the lower extremity, and installation of Ilizarov foot and ankle distraction devices for slow distraction and correction of residual foot and ankle deformities. After removal of external fixation, individualized braces were used for protection during exercise and walking. For patients with bilateral deformities, staged surgeries were performed. The effectiveness was evaluated according to the QIN Sihe's Postoperative Evaluation Criteria for Lower Limb (Foot and Ankle) Deformity Correction and Functional Reconstruction at last follow-up. Results:All patients achieved the preoperative expected orthopedic and functional reconstruction goals. The postoperative wearing time of external fixator was 3-7 months, with an average of 5.5 months. The incidence of pin tract infection during the treatment period was 6.5% (4/62). All patients were followed up 25-132 months (median, 42 months). All 56 patients successfully retained their limbs. At last follow-up, foot and ankle deformities were corrected, the weight-bearing line was basically restored, and plantigrade feet were restored. At last follow-up, according to QIN Sihe's Postoperative Evaluation Criteria for Lower Limb (Foot and Ankle) Deformity Correction and Functional Reconstruction, the effectiveness was rated as excellent in 37 cases (39 feet), good in 18 cases (21 feet), and fair in 1 case (2 feet). The excellent and good rate was 96.8% (60/62). Conclusion:The combination of QIN Sihe's surgical strategy and Ilizarov technique in treating foot and ankle deformities on verge of amputation is minimally invasive, safe, and the therapeutic effect is controllable. This combined approach has unique advantages in preserving limb function and restoring biomechanical balance.

Objective:To investigate the effectiveness of applying a standardized rehabilitation process in correction of adult clubfoot with the Ilizarov technique. Methods:Thirty-eight adult patients who underwent orthopedic treatment with Ilizarov technique for clubfoot between August 2022 and December 2024 were retrospectively analyzed. The patients were divided into a study group and a control group with 19 cases in each group according to the different rehabilitation management processes and methods. The differences in baseline data such as gender, age, side, and preoperative Holden walking function grading between the two groups were not significant ( P>0.05). In both groups, most of the clubfoot deformities were surgically corrected first, and the residual deformities were corrected by dynamic slow retraction with Ilizarov ring-type external fixation frame. The study group adopted standardized rehabilitation process management mode, including preoperative lower limb muscle strength training, postoperative pain and swelling management, weight-bearing management, gait and lower limb stability training. The control group adopted the conventional postoperative rehabilitation management mode. The occurrence of complications was recorded, including pin tract infection, ankle stiffness and pain, and deformity recurrence. Holden walking function grading was used to evaluate the walking ability of the patients. Clinical efficacy was evaluated by the QIN Sihe Deformity Correction Disability Repair and Functional Reconstruction Postoperative Efficacy Evaluation Scale. Patient satisfaction was evaluated by Likert score. Results:Patients in both groups successfully completed surgery and rehabilitation and were followed up. The follow-up time ranged from 8 to 29 months, with a mean of 18.5 months. Among them, the follow-up time was (18.8±5.5) months in the study group and (18.2±5.7) months in the control group, and the difference between groups was not significant ( t=0.316, P=0.754). The postoperative incidences of pin tract infection, ankle stiffness and pain, and deformity recurrence in the study group were 10.53%, 5.26%, and 5.26%, respectively, and in the control group were 21.05%, 36.84%, and 15.79%, respectively. And the difference between groups in the incidence of ankle stiffness and pain was significant ( P=0.042). At last follow-up, both groups showed an improvement in Holden walking function grading compared to preoperative levels ( P<0.05), and the grading of the study group was significantly higher than that of the control group ( P=0.006). According to the QIN Sihe Deformity Correction Disability Repair and Functional Reconstruction Postoperative Efficacy Evaluation Scale, the grade difference between groups was not significant ( P=0.089), and the excellent and good rates of clinical efficacy in study group and control group were 89.47% (17/19) and 73.68% (14/19), respectively. Patient satisfaction in study group was significantly better than that in control group ( P=0.036). Conclusion:Standardized rehabilitation process can effectively promote the postoperative functional recovery of adult clubfoot treated with Ilizarov technique, reduce the risk of complications and improve effectiveness.

Background:Limb deformities are almost associated with varying degrees of disability, which severely affects the quality of life and social participation. However, the epidemiological profiles of limb deformities remain underreported. As the world's largest developing country with regional economic disparities, China faces unique challenges in the diagnosis and management of limb deformities. The Qin Sihe Orthopaedic Surgery Database is currently the most comprehensive database of limb deformity in China, which has the largest case volume, the widest disease spectrum, and the broadest geographical coverage, provides an invaluable resource for studying limb deformity patterns in China and other developing countries. Objective:To analyze 37763 limb deformity cases from the Qin Sihe Orthopaedic Surgery Database, and to summarize the etiology distribution, disease spectrum, gender, age, geographical distribution, gait abnormalities and treatment strategies of limb deformities in China. Methods:Descriptive epidemiological methods were used to analyze the data of Qin Sihe Orthopaedic Surgery Database from May 25th, 1978 to December 31st, 2023 containing 37763 cases of Limb deformities. The data on patients' gender, age, etiology distribution, disease spectrum, geographical distribution, gait abnormalities and surgical methods etc will be statistically analyzed. Results:Among 37763 patients, 21815 (57.77 %) were male and 15948 (42.23 %) were female, aged 1-84 years old, covering 33 provinces, municipalities and autonomous regions in China and some international regions. Etiologies included 239 neurogenic, traumatic, congenital and metabolic diseases, among which neurogenic diseases took the dominant portion: 24430 (64. 7 %) cases of post-polio sequelae, 5088 (13. 4 %) cases of cerebral palsy. Lower limb deformities(35,869 cases,95 %) was significantly more than upper limb deformities (646 cases, 1.7 %). The surgical interventions included soft tissue release and tendon lengthening (e. g. Achilles tendon lengthening, 8282 cases, 21.93 %), osteotomy (e.g. supracondylar femoral osteotomy, 7740 cases, 20.50 %), and arthrodesis (e. g. talocalcaneal arthrodesis, 6873 cases, 18.20 %). The fixation methods included Ilizarov external fixation (5611 cases), combined external fixation (5612 cases), combined internal fixation (1805 cases) and plaster or brace immobilization (24735 cases). Conclusion:The causes of limb deformities in China are diverse, and the diseases involves multiple disciplines. Cases are predominantly male and young., Polio sequelae deformity remains the main malformation diseases, but the proportion of cerebral palsy, limb deformities after trauma, lower limb deformities after spina bifida and genetic metabolic diseases are increasing. This study provides important real-world data for the classification of etiological classification, precise diagnosis and treatment, and public health policy formulation of limb deformities in China. The translational potential of this article:This study is the most comprehensive big data analysis to date on the causes and treatment of limb deformities in China. The research results have revealed the main epidemiological characteristics of limb deformities in China, which is helpful for formulating more effective disability prevention and control strategies at the clinical diagnosis and public health levels in the future. Based on this data, a big data model for lower limb deformities may be gradually established, and the disease prevention and treatment system for limb deformities can be improved. According to the different types and causes of the diseases, the prevention and treatment level of limb deformities can be enhanced, and the disability rate caused by limb deformities can be reduced. In the future, the application depth of artificial intelligence-assisted diagnosis and interdisciplinary collaboration mechanisms can be further expanded.

External fixation devices are essential tools in the field of foot and ankle reconstruction. Mastering the fundamental knowledge and skills of external fixation is crucial for the effective application of this technique. Currently, domestically produced external fixation systems for the foot and ankle can meet the needs of treating various foot and ankle traumas, deformities, and functional reconstruction. Through this special issue on "External fixation and foot and ankle reconstruction", we provide a detailed introduction to the essential knowledge and skills that physicians must acquire to proficiently manage external fixation and foot and ankle reconstruction.

Objective:To summarize the research and clinical application progress of foot lengthening surgery. Methods:Relevant research literature on foot lengthening surgery in recent years at home and abroad was reviewed, and a summary was made from aspects such as the types of lengthening surgery, the types of foot diseases treated by clinical application, effectiveness, and complications. Results:Bone defects and shortening deformities of the foot are relatively common clinically. As an innovative treatment method, foot lengthening surgery has gradually attracted attention, mainly including the Ilizarov technique and one-stage bone grafting lengthening surgery. The former promotes bone regeneration based on the tension-stress principle and is widely used in the treatment of calcaneal defects and congenital metatarsal brachymetatarsia, achieving good curative effects. However, there are also complications such as pin-tract infection, joint stiffness and contracture, non-union and delayed union of bone, re-fracture, and alignment deviation. The latter has a short treatment cycle, but the lengthening length is limited. Bone graft resorption and soft tissue complications are its main complications. Conclusion:Foot lengthening surgery will develop towards the direction of personalization, intelligence, and precision. With the help of multi-center research, biological materials, and intelligent technologies, the effectiveness and safety will be further improved to better restore the function and appearance of the foot.

Objective:To review the research progress on correction of severe foot and ankle deformities with digital hexapod external fixators. Methods:The relevant research literature on digital hexapod external fixators at home and abroad in recent years was reviewed and analyzed. Taking Taylor spatial frame (TSF) as a representative, this article elaborates on the research progress of this technology in the treatment of severe foot and ankle deformities from aspects such as device principle, technical characteristics, clinical application, complication management, and controversial perspectives, aiming to provide theoretical references for clinical application. Results:The treatment of severe foot and ankle deformities is a complex challenge in orthopedics, often involving multiple plane alignment abnormalities, muscle weakness, soft tissue contractures, and joint dysfunction. The digital hexapod external fixators (such as TSF), based on the principle of six degrees of freedom motion and combined with computer-assisted technology, enables precise correction of multi-dimensional deformities. Conclusion:The digital hexapod external fixators provides a minimally invasive and efficient option for the treatment of severe foot and ankle deformities, and shows significant advantages in the treatment of complex post-traumatic deformities, neuromuscular deformities, diabetes Charcot arthropathy, and other diseases.

RATIONALE:Severe fixed knee flexion deformities and significant limb shortening resulting from childhood osteoarticular infections are uncommon in clinical adult orthopedics and present considerable surgical challenges. PATIENT CONCERNS:A 23-year-old female presented with a 130° fixed knee flexion deformity and severe limb shortening. Despite recommendations for amputation from multiple hospitals, the patient insisted on pursuing limb-preserving surgical options. DIAGNOSES:The patient was diagnosed with a severe fixed knee flexion deformity and significant limb shortening due to childhood pyogenic knee infection. INTERVENTIONS:A staged surgical strategy was adopted. The first stage included wedge osteotomy combined with the Ilizarov technique for deformity correction and partial limb length restoration. The second stage utilized femoral and tibial osteotomies with the Ilizarov method for further lengthening, complemented by steel pin stimulation for delayed tibial healing. OUTCOMES:At the 7.5-year follow-up, the patient achieved near-equal limb lengths, restored walking ability, and substantial functional improvement. At the 11-year follow-up, the patient retained the ability to walk independently. Residual knee joint stiffness was observed but did not significantly impact daily activities. LESSONS:This case demonstrates the effectiveness of the Ilizarov technique in correcting extreme deformities and achieving significant limb lengthening. Its success highlights the importance of systematic preoperative evaluation, meticulous surgical planning, and strong patient collaboration. Furthermore, this case highlights the critical need for long-term monitoring of pediatric osteoarticular infections to mitigate the risk of subsequent limb deformities during growth and development.

Objective:To describe the characteristics of short arm deformity in patients with achondroplasia, and summarize the progress of its lenthening and reconstruction, so as to provide reference for clinical diagnosis and treatment. Methods:The literature on the lenthening of upper limb with achondroplastic short arm deformity at home and abroad in recent years was reviewed, and the characteristics, extension methods, postoperative management, effectiveness evaluation, and related complications of short arm deformity were summarized. Results:Achondroplastic short arm deformity affect the patient's daily perineal hygiene activities. Although the upper limb is proportionately shortened, the humerus is mainly short limb deformity. Bilateral humeral lengthening is a common treatment method, and the traditional lengthening tools are mainly external fixation, guided by Ilizarov distraction osteogenesis concept; intramedullary lengthening is the latest treatment method. Lengthening percentage and healing index are commonly used for clinical evaluation indexes, and complications such as nerve injury may occur during upper limb lengthening. Conclusion:In addition to appearance improvement, achondroplastic short arm lengthening is of great significance in achieving self-management of individual perineal hygiene. Lenthening and reconstruction methods are constantly being innovated and improved.

Objective:To summarize the methods of ankle hinge position design in the correction of clubfoot deformity by Ilizarov method, and to explore its application value in the prevention of ankle dislocation. Methods:A retrospective study was conducted including 28 patients with rigid clubfoot deformity (34 feet) who met the selection criteria and admitted between September 2021 and December 2024. There were 19 males and 9 females with an average age of 31.8 years (range, 19-47 years). According to Dimeglio classification, there were 21 feet of degree Ⅲ and 13 feet of degree Ⅳ. The causes were traumatic sequelae in 9 cases, congenital foot deformity in 15 cases, spina bifida sequelae in 1 case, peripheral neuropathy in 1 case, and cerebral palsy sequelae in 2 cases. The malformation lasted from 6 to 46 years, with an average of 29.3 years. All patients were treated with Ilizarov circular external fixator, and the hinge position of ankle joint was planned according to the standard lateral X-ray film of foot and ankle and the principle of Ilizarov limb deformity correction center of rotation angulation (CORA) before operation. The 2008 International Clubfoot Study Group (ICFSG) scoring system was used to evaluate the efficacy. Results:The deformity of rigid clubfoot was completely corrected in all patients, and the patients could walk with plantar weight-bearing, and the ankle weight-bearing walking significantly improved when compared with that before operation. There was no complication such as ankle dislocation, talus impact or extrusion, local skin necrosis, needle tract infection, or numbness of extremities during the correction process. All patients were followed up 5-39 months, with an average of 18.1 months. At last follow-up, according to the ICFSG scoring system, 23 feet were excellent, 10 feet were good, and 1 foot was fair, and the excellent and good rate was 97%. Conclusion:Designing the position of the ankle hinge according to the principle of CORA can effectively avoid ankle dislocation, talus impingement, tibiotalar joint extrusion, and other ankle adverse events in the process of correcting clubfoot deformity, which has good application value in clinical practice.

Objective:To explore the corrective strategies and effectiveness of osteotomy surgery for severe lower limb deformities in hypophosphatemic rickets. Methods:A retrospective analysis was conducted on 29 patients with severe lower limb deformities of hypophosphatemic rickets who underwent surgical treatment between February 2012 and August 2024. There were 9 males and 20 females. The age ranged from 13 to 53 years, with an average of 24.6 years. All patients were deformities of both lower limbs, presenting as 24 cases of O-shaped legs, 2 cases of wind-blown deformities, and 3 cases of X-shaped legs. Based on the full-length films of both lower limbs in the standing position before operation, the osteotomy planes of the femur, tibia, and fibula were designed. Among them, if both the same-sided thigh and leg were deformed, staged surgeries of both lower limbs were selected. If only the thigh or leg were deformed, simultaneous surgeries of both lower limbs were selected. The femur deformity was corrected immediately after osteotomy at the deformed plane; the osteotomy fragment was temporarily controlled with an external fixator, which was removed after perform internal fixation with a steel plate. After fibular osteotomy, the Ilizarov frame or Taylor frame was installed on the tibia and fibula. The threaded rods were removed and then tibial osteotomy was performed on the deformed plane. Patients using the Taylor frame did not undergo deformity correction during operation. The external fixators were adjusted starting 7 days after operation to correct the varus, valgus, and rotational deformities of the lower limb. Patients using the Ilizarov frame corrected the rotational deformity of the tibia during operation. The external fixator was adjusted starting 7 days after operation to correct the varus and valgus deformities of the lower limb. During the treatment period, the patient could walk with partial weight-bearing on the operated limb with crutches. The external fixator was removed after the bone healed. Before operation and at last follow-up, the medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), posterior proximal tibial angle (PPTA), anterior distal tibial angle (ADTA), anatomic lateral distal femoral angle (aLDFA), posterior distal femoral angle (PDFA), and mechanical axis deviation (MAD), lower limb rotation, limb length discrepancy (LLD) were measured. The self-made scoring criteria were adopted to evaluate the degree of lower limb deformity of the patients. Results:All operations were successfully completed, and no complications such as nerve or vascular injury occurred. The adjustment time of the external fixator of the lower limb after operation was 28-46 days, with an average of 37.4 days. The wearing time of the external fixator ranged from 134 to 398 days, with an average of 181.5 days. Mild pin tract infections occurred in 2 limbs. The osteofascial compartment syndrome occurred in 1 limb after operation. No complications related to orthopedic adjustment of the external fixator occurred in other patients. All patients were followed up 6-56 months, with an average of 28.2 months. At last follow-up, full-length films of both lower limbs in the standing position showed that the coronal mechanical axes of the lower limbs of all patients returned to the normal. At last follow-up, MPTA, LDTA, PPTA, aLDFA, PDFA, MAD, lower limb rotation, LLD, and the score of lower limb deformity significantly improved when compared with those before operation ( P<0.05). There was no significant difference in ADTA between pre- and post-operation ( P>0.05). The degree of lower limb deformity were rated as moderate in 2 cases and poor in 27 cases before operation and as excellent in 7 cases, good in 18 cases, and moderate in 4 cases at last follow-up, with an excellent and good rate of 86.2%. Conclusion:For severe lower limb deformities in hypophosphatemic rickets, immediate correction of deformities with femoral osteotomy and internal plate fixation, as well as gradually correction of deformities with tibiofibular osteotomy and circular external fixation (Ilizarov frame or Taylor frame), have satisfactory therapeutic effects.

ObjectiveAt present, due to the lack of early observation methods, the effect of the ‘accordion’ technique on the treatment of nonunion of the docking site varies greatly. In this study, color Doppler ultrasound was used to observe the docking site's local changes and investigate the relationship between local microenvironment changes and bone healing after the accordion technique.Methods30 patients with tibial bone transport treated at the Department of Orthopedics, Second Hospital of Shanxi Medical University, from May 2018 to June 2022, were analyzed retrospectively. Paired‐sample t‐tests were used for data that conformed to a normal distribution, and paired rank‐sum tests were used for before‐and‐after comparisons that did not conform to a normal distribution. There were 26 males and 4 females, aged 47.3 ± 11.7 years. Before bone transport, the defect gap between tibial bone ends was 6.80 ± 3.61 cm. The steps of the accordion technique were as follows: compression for 7 days, ultrasonic study of the microenvironment at the docking site, distraction for 12 days, latency for 7 days, compression for 14 days, then static fixation and radiological study until complete bone healing. Ultrasound was used to detect the size of the hematoma after 7 days of pressure, and the changes in blood flow before and after the ‘accordion' operation.ResultsAll patients were followed up for 11.9 ± 1.9 months. At the last follow‐up, 22 patients achieved bone healing at the docking site after the treatment of the ‘accordion’ technique. There was a linear negative correlation between the size of the hematoma and the time of bone healing at the docking site (r = −0.639, p < 0.01). According to the Paley healing criteria, 18 of the 22 patients were excellent, and 4 patients were good.ConclusionHematoma is necessary for the ‘accordion’ technique's success in the treatment of nonunion. The size of the hematoma is negatively related to the time of bone healing. The ‘accordion’ technique can increase the blood flow of tissue around the docking site. Ultrasound can be used to monitor the changes in the microenvironment at the docking site during the ‘accordion’ technique and guide the exact plan and prognosis of the ‘accordion’ technique.

ObjectiveThe principles of limb reconstruction are crucial for treatment success, but there is no unified standard for complex limb deformities. The aim of this study was to analyze the characteristics of the cases of post‐traumatic lower limb deformity and explore the new principle of limb reconstruction.MethodA retrospective analysis was conducted of 148 patients with post‐traumatic lower limb deformity who underwent surgery from May 1978 to December 2023; 85 were males (57.4%) and 63 were females (42.6%); 65 cases of left side (43.9%), 79 cases of right side(53.4%), and 4 cases were on both sides (2.7%), the average age was 24.64 years (5–69). There were 4 cases suffering hip deformities, 40 cases of femoral deformities, 18 cases from knee, 40 cases from tibiofibular, 93 cases of foot and ankle deformities, and some patients also had two or more types. All patients underwent surgical intervention in an average of 40.5 months (12–96) after injury. According to the evaluation of limb deformities, deformity correction and functional reconstruction with external fixation were implemented, following the principle of “one walking, two lines, and three balances.” The clinical evaluation adopts the criteria of Qinsihe lower limb deformity correction and functional reconstruction.Result148 patients with post‐traumatic lower limb deformities were followed up for 40.9 (12–356) months. The main surgical procedures implemented were tendon lengthening and soft tissue release (84 cases), osteotomy (93 cases), joint fusion (30 cases), and tendon transposition (16 cases); there were multiple surgical procedures in some patients. Among them, 124 cases used external fixators for stress control and 27 cases used internal fixation, while 3 cases used plaster or brace. There were 5 wire reactions postoperatively, which improved after dressing change and oral antibiotics. There were 2 pin infections, which improved by pin removing. No surgical related deep infections occurred, and no surgical related neurovascular damage occurred. At the last follow‐up, all limb deformities were corrected, limb function improved, and the results of treatment was very satisfactory. According to Qinsihe evaluation criteria for lower limb deformities, 74 cases were excellent, 56 cases good, and 18 cases fair, with an excellent and good rate of 87.84%.ConclusionStress control with external fixation is effective, safe, and controllable in correcting and reconstructing post‐traumatic lower limb deformities. The principle of “one walking, two lines, and three balances” plays an important role in the entire process of stress control limb reconstruction.