Background: Distal femoral non-unions are challenging, and frequently associated with short distal fragments, poor bone stock, and with issues from previous implants. Materials and methods: A retrospective study of 31 patients admitted with distal femoral non-unions treated using anatomical lateral locking plates. Non-union scores were used. The Knee Society and Neer’s scores were used for the comparison of results. The mean follow-up was 39.5 months (from 24 months to 60 months). Results: Stable union was accomplished in all. There was a significant improvement in the average Neer’s score (24 preoperative to 82 post-operatively at final follow-up), the Part 1 Knee Society score from an average of 46 preoperatively to 84 post-operatively, and Part 2 Knee Society score from 36 preoperatively to 80 post-operatively. Conclusion: Optimal stability, good compression at the non-union site (either by lag screws or a compression device or both), maintaining the axial alignment strictly, freshening of bone ends, using an adequate amount of cortico-cancellous bone graft, respecting the biology along with the correct choice of the implant (including the size) are essential to achieve union at the fracture site. Clinical significance: Paying attention to the basic principles of management, good contact, stability and maintaining biology is essential in the treatment of non-union.

Aim: When a leg-length discrepancy (LLD) is severe enough, it can result in lumbar scoliosis and other postural defects. To our knowledge, no study has demonstrated associations between LLD and lumbar curvature using full-length standing radiographs of the lower limbs and lumbar spine. This study aimed to examine the correlations between LLD and lateral curvature of the lumbar spine using standing radiographs. Materials and methods: Full-length standing radiographs of the lower limbs and spinal column of 113 participants (age range: 10–65 years) obtained between November 2006 and September 2019 were reviewed. Leg length was measured as the linear distance from the centre of the femoral head to the centre of the tibial plafond and converted to millimetres using a radiographic ruler captured in the images. Leg-length discrepancy was analysed as the absolute difference (mm) between the left and right leg lengths. Inequality was also evaluated as leg-length discrepancy ratio (LLDR), calculated as leg-length discrepancy/length of the unaffected (longer) leg × 100 (%). Lateral lumbar curvature was evaluated with the Cobb angle (°). The association between LLD or LLDR and lumbar Cobb angle was analysed by correlation analysis. Statistical analysis was performed by simple regression in SPSS. Results: Both LLD and LLDR exhibited a robust and positive correlation with lumbar Cobb angle (γ = 0.53, γ = 0.62), as illustrated by the following regression equations: lumbar Cobb angle (°) = 0.316 × leg-length discrepancy (mm) + 2.83 and lumbar Cobb angle (°) = 2.19 × leg-length discrepancy ratio (%) + 3.0. Conclusion: Using objective imaging data, we found that the lumbar Cobb angle tends to be >10° if the difference in leg lengths is >20 mm.

Introduction: Limb lengthening is increasingly accomplished by internal lengthening nails. Previous versions of the magnetic lengthening nails made from titanium alloy allowed limited weight-bearing. In contrast, the newer nails made of stainless steel allow increased weight-bearing. An objective comparison of the rate of healing of the regenerate bone based on the weight-bearing capabilities of these two types of lengthening nails has not been evaluated. The hypothesis for the study is that earlier commencement of full weight-bearing in patients treated with the stainless steel STRYDE^® nail will lead to faster healing of the regenerate bone during intramedullary limb lengthening compared with those treated with the titanium PRECICE^® nail. Materials and methods: Thirty patients, divided into two groups of 15 each, underwent antegrade intramedullary lengthening of the femur using a magnetic lengthening nail between May 2017 and November 2020. The pixel value ratio (PVR) obtained from serial digital radiographs was used to quantitatively determine the regenerate bone’s mineralisation rate. We compared the rate of healing of the regenerate bone in both groups of patients using the PVR. Results: Patients treated with the STRYDE^® nail achieved unassisted full weight-bearing significantly earlier than patients treated with the PRECICE^® nail (12 weeks vs 17 weeks for STRYDE^® and PRECICE^® nail-lengthened patients, respectively, p = 0.003). There was no difference in the PVR between both groups of patients at the time of full weight-bearing (p = 0.0857). However, patients treated with the STRYDE® nail attained a PVR of 1 significantly earlier than those treated with the PRECICE^® nail (0.0317). Conclusion: The STRYDE^® nail provides an earlier return of function and full weight-bearing compared with the PRECICE^® lengthening nail. Earlier commencement of weight-bearing ambulation leads to more rapid mineralisation of the regenerate bone in patients undergoing intramedullary limb lengthening.

Background: Bone-lengthening nails result in various complications with different severity and origin. However, no universal reporting system for complications has been agreed upon, making it difficult to compare different nail designs and patient populations. This study aimed to assess the inter- and intra-rater agreement of a classification system of complications according to severity and origin. Materials and methods: Four orthopaedic surgeons assessed 48 complications retrieved from patient charts in a single-centre cohort and 49 literature complications cases. Complications were classified according to severity grading (I, II, IIIA and IIIB) from Black et al. and origin with eight main types and 33 subtypes. A blinded independent assessment was performed twice at least six weeks apart. Cohen/Congers kappa estimated for the inter- and intra-rater agreement was interpreted after Svanholm et al. Results: The surgeons had a good inter-rater agreement for complication severity with a kappa value of 0.68 [95% confidence interval (CI): 0.56–0.79] and complication origin with a kappa value of 0.63 (CI: 0.53–0.73), respectively, on the cohort cases. In literature cases, a good agreement on complication severity and origin grading was shown by kappa values of 0.64 (CI: 0.53–0.75) and 0.74 (CI: 0.65–0.83). The intra-rater assessment of complication severity and origin grading had good to excellent agreement with kappa values ranging from 0.51 to 0.97. Conclusion and clinical significance: The study presents the first structured complication classification on severity and origin in intramedullary bone-lengthening nails. A good reproducibility agreement in both severity and origin was found between four orthopaedic surgeons for both cohort and literature complication cases. For clinical and research purposes, a shared language for communicating complications is essential. We encourage future studies to use a structured and validated complication classification.

Aim: Evaluate the validity of a recent approach to calculate the knee flexion or extension contracture contributing to the overall sagittal deformity using the sagittal mechanical axis angle (SMAA) for the overall alignment assessment and sagittal joint line angle (SJLA) for soft tissue contribution. The methods of evaluating these angles and their clinical applications are discussed. Materials and methods: In total, 107 normal limbs met the criteria and were divided into two groups: skeletally mature and immature. Sagittal alignment was evaluated using the Bone Ninja iPad application, and the posterior distal femoral angle (PDFA), posterior proximal tibial angle (PPTA), SMAA and SJLA were recorded. Results: In skeletally immature patients, mean SJLA was 13.46° [standard deviation (SD), 4.55°], and in mature patients, it was 16.91° (SD, 2.948°). The PDFA and PPTA were consistent with previously published measurements. Conclusion: The SJLA method is a practical way to quantify the soft tissue contribution and degree of contracture. It can also be used for monitoring deterioration or improvement of knee range of motion during lengthening or physical therapy. Clinical significance: All patients in this study presented to our clinic with symptoms on the contralateral side. This, in addition to the retrospective nature, was a limitation in our study. We recommend a validity study to compare our SJLA method to the classic anterior cortical line angle (ACL) method in addition to an inter-observer and intra-observer reliability study for the SJLA. We also recommend a study on completely normal asymptomatic subjects to better standardise the angle measurements in skeletally immature patients at different ages.

Aim: In the past decade, internal limb lengthening nails have gained popularity. In this study, we aim to systematically review the literature on humerus limb lengthening with a motorized intramedullary nail (MIN). We intend to assess the outcome and complications of this technique. Materials and methods: A systematic review was performed in the following databases: PubMed, Embase, Web of Science, and the Journal of Limb Lengthening and Reconstruction. The inclusion criteria included limb lengthening of the humerus using an intramedullary nail, clinical studies, all levels of evidence, and no restriction to the date of publication. Results: Our search yielded 239 journal articles. A total of nine articles remained relevant based on the inclusion and exclusion criteria. The total number of patients was 20, with 22 segments lengthened. The mean age of the patients was 20.8-year-old [standard deviation (SD), 12.0; range, 13–51]. The mean gained length was 5.7 cm (SD, 0.9; range, 5–7.5) with a mean distraction protocol of 0.82 mm/day (SD, 0.2; range, 0.6–1). The average duration of lengthening was 71.6 days (SD, 12.8; range, 50–93), and the mean duration of consolidation was 192.3 days (SD, 40.5; range, 120–228). Reported complications included a range of motion (ROM) limitation, hardware failure, and hypertrophic bone regeneration. Conclusion: Humeral lengthening with an MIN provides favourable outcomes with low complication rates. Future high-level studies should focus on comparing long-term outcomes of humeral lengthening utilising internal and external fixation techniques. Clinical significance: Humeral lengthening using MIN can be used safely. Each surgical approach and type of nail have different risks and benefits. These should be carefully discussed when planning the surgery.

Introduction: Tibial non-unions present with complex deformities, bone loss, infection, leg length discrepancy (LLD), and other features which influence function. Circular frame-based treatment is popular with the hexapod system used increasingly. This systematic review aims to determine the clinical and radiological outcomes of hexapod fixation when used for tibial non-unions. Materials and methods: The review was performed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The search strategy was applied to MEDLINE and Embase databases on 15 December 2021. Studies reporting either clinical or radiological outcomes following hexapod fixation on tibial non-unions were included. Primary outcomes were radiological union and patient-reported outcome measures (PROMs). Secondary outcomes included LLD, tibial alignment deformity (TAD), return to pre-injury activity and post-operative complications. Results: After the abstract and full-text screening, 9 studies were included; there were 283 hexapod frame fixations for tibial non-unions. Infection (46.6%) and stiff hypertrophic non-union (39.2%) accounted for most non-unions treated. The average age and mean follow-up were 42.2 years and 33.1 months, respectively. The average time to union was 8.7 months with a union rate of 84.8%. A total of 90.3% of patients had TAD below 5° in all planes, with an LLD ≤1.5 cm of the contralateral leg in 90.5%. Bony and functional results were at least good in over 90% of patients when using the Association for the Study of the Method of Ilizarov (ASAMI) criteria. A total of 84% of patients returned to pre-injury activities. There were complications as follows: a total of 34% developed pin-site infection, almost 9% experienced half-pin breakage and 14% developed an equinus ankle contracture. Conclusion: Hexapod frames for the treatment of tibial non-unions produce favourable functional outcomes. Complication rates are present and need to be discussed when this modality of treatment is proposed. Further comparative studies will allow for this option to be evaluated against that of the traditional Ilizarov frame and other methods of non-union surgery.

Aim: To describe the surgical technique for gradual lengthening of the metatarsal using the Orthofix MiniRail System (Orthofix Medical Inc., Lewisville, TX, USA). Background: Brachymetatarsia refers to the shortening of the metatarsal bone. When indicated, metatarsal lengthening is performed to treat this deformity. Technique: A dorsal approach to the short metatarsal is performed, protecting the neurovascular structures and the extensor tendons. The most proximal wire or screw is inserted first, followed by the most distal wire or screw. The distal wire or screw should not be inserted in the metatarsal head. The middle wires or screws are inserted thereafter. All wires or screws should be placed perpendicular to the anatomic axis of the bone. Once the MiniRail lengthener is assembled, a 1.6 mm K-wire is inserted from the tip of the toe into the metatarsal head, blocking the motion of the metatarsophalangeal joint and avoiding joint subluxation during lengthening. The osteotomy is then performed perpendicular to the metatarsal shaft, in between the middle two wires and screws. Conclusion: The surgical technique for gradual lengthening of the metatarsal using the Orthofix MiniRail System was described in detail with accompanying step-by-step intraoperative clinical and fluoroscopic images. Clinical significance: This surgical technique of metatarsal lengthening is simple and effective. An understanding of the surgical technique of gradual lengthening of the metatarsal bone is important when treating shorting deformities of more than 1 cm.

Aim: To describe the surgical technique of performing an all-internal lengthening to address a large diaphyseal femur defect in the sarcoma patient. Background: Various strategies exist to address large intercalary bone defects with various biomechanical and biological implications. Case description: A 23-year-old female with high-grade osteosarcoma of her left femur underwent wide resection and an internal reconstruction of a 12.5-cm femoral defect using dual magnetic lengthening intramedullary nails resulting in restoration of leg lengths, and pre-resection function with minimal residual disability. Conclusion: Preoperative chemotherapy, wide resection and post-operative chemotherapy for osteosarcoma are the current standard of care. Resection often leads to large bone defects requiring complex reconstruction. Following intercalary bone resection, biological reconstruction is a consideration. An all-inside technique was developed in an effort to minimise complications of long-term external fixation for distraction osteogenesis, or extensile secondary grafting procedures for induced membrane strategy. Clinical significance: This previously unreported surgical technique allows for an all-internal lengthening of large diaphyseal bone defects. While specifically used in an oncologic post-resection setting, this technique is applicable to the broader limb reconstruction and lengthening practice and overcomes some inherent limitations to previously described techniques.

Aim: This study describes the intentional deformation and shortening of a limb using external fixation (EF) in three patients with post-traumatic injury tibial defects and to assess the outcomes. Case description: Three patients with infected non-unions and massive bone and soft tissue defects who were treated with temporary intentional leg shortening and deformation using a Taylor Spatial Frame (TSF) EF were retrospectively reviewed. The alignment was restored by gradual deformity correction and lengthening after a 2-week interval. No additional surgical intervention was required for soft tissue reconstruction after primary skin closure. Skin closure and good bone alignment were achieved in all patients. The functional outcomes and bone outcomes were evaluated for all cases according to the Paley criteria modified by the Association for the Study and Application of Methods of Ilizarov. All patients showed excellent bone outcomes. Two patients achieved excellent functional outcomes and one had a good outcome. The patient with a good outcome was unable to descend the stairs comfortably. Conclusion: This technique is suitable for treating massive bone and soft tissue defects and should be considered as a treatment option.