Average Leg Length Discrepancy Research Articles

Biomechanics of a collum-fixated short stem in total hip arthroplasty

BackgroundBiomechanical reconstruction of the hip significantly impacts the clinical outcome and implant survival. Our knowledge is limited of the ability of neck-stabilised prostheses to restore hip biomechanics. We hypothesised that hip biomechanics, specifically leg length and global offset (GO), may be restored to an acceptable range using the Primoris™ stem. Methods and materialIn this retrospective study, we analysed 152 patients who underwent total hip replacement (THA) using the short collum-fixated stem Primoris™.The primary outcomes were hip parameters measured by x-ray following THA using the Primoris™ stem. After surgery, the biomechanical parameters used were measured at the arthroplasty and the native contralateral side of the same x-ray. The X-rays were taken one year after the patient's surgery.1. GO.2. Leg length discrepancy (LLD).3. Neck shaft angle (NSA). ResultsWe recorded an average GO of −3.4 mm (standard deviation (SD) 7.2) and an average LLD of +3.8 mm (SD 6.4). Furthermore, we registered an average 14-degree NSA increase (SD 7.4). ConclusionThe Primoris™ neck-stabilised stem enabled hip anatomy restoration to a favourable range with respect to GO and LLD as the average difference fell within ±5 mm. However, the stem tended to be implanted in valgus.

Results of Total Hip Replacement Surgery Using Short-Stem Spiron Prosthesis in Vietnamese Adults.

Total hip arthroplasty with traditional stem joints, although bringing many benefits to patients indicated for hip replacement, faces many difficulties in reoperations in young patients due to the limited lifespan of the artificial joint. Recently, the short-stem joint was introduced to help overcome this problem. This study aims to evaluate the results of short-stem implants for primary total hip arthroplasty in Vietnamese adults. The study design is retrospective longitudinal. The study subjects were 91 patients with aseptic necrosis of the femoral head who underwent short-shaft cementless total hip replacement surgery from February 2012 to December 2018. Outcomes that were assessed included implant survivorship, Harris hip scores, thigh pain, periprosthetic fracture, subsidence, proximal stress shielding, the prevalence of stem malalignment, and inappropriate implant sizing. Our research group has 119 hips of 91 patients (28 patients had hip replacements on both sides), with the average follow-up time of 67.1 months. Seven cases of early joint loosening required replacing the traditional stem. The survival rate is 94.1%. The average Harris hip score 24 months after surgery was statistically significantly higher than before (92.00 ± 4.47 and 45.56 ± 3.22, respectively, p < 0.001). The average leg length discrepancy between the two limbs before surgery was 9.5 ±mm and 24 months after surgery was 3.4 ± 2.9 mm. There were 12 cases (10.1%) of partial bone loss around the femoral stem; 12 cases of joint displacement of more than 2 mm, accounting for 10.1%; and 1 case of acetabular fracture, accounting for 0.8%. The Spiron short stem has certain advantages suitable for young patients, restoring the hip anatomy and significantly improving postoperative hip function. However, this is a complex technique that needs to be performed by experienced surgeons who have practiced for a long time. We encourage using the short-stem implant during primary total hip arthroplasty in Vietnamese adult patients.

Treatment of Concomitant Congenital Pseudarthrosis of the Fibula With Propeller Periosteal Flap.

Congenital pseudarthrosis of the fibula is not an uncommon condition to accompany congenital pseudarthrosis of the tibia. Persistence of the fibular pseudarthrosis has been linked to inferior outcomes including tibial union and alignment, refractures, and ankle alignment. In this report, we present the results of a pedicled periosteal propeller flap technique for the treatment of fibular pseudarthrosis. Ten children with an average age at surgery of 5.3 years who had congenital pseudarthrosis of both tibia and fibula were studied. The tibia was treated with free vascularized fibular grafting, and the ipsilateral fibula was treated with a technique after resection of the pseudarthrosis. A periosteal flap from the proximal healthy part of the fibula is harvested off the bone, rotated 180° based on a branch from the peroneal vessels to cover the fibular defect and fashioned in the form of a tube filled with bone fragments. The periosteal flap size ranged from 5 to 7 cm. Follow-up averaged 37.2 months. The tibia was united in all cases; in 2 of them, refractures occurred and healed with conservative management. The fibula was united in 8 cases. At final follow-up, 5 cases showed residual tibial deformity, and 5 showed residual ankle deformity. Average leg-length discrepancy was 1.4 cm (0-3 cm). The pedicled periosteal propeller flap presents a useful new technique for managing concomitant congenital fibular pseudarthrosis.

Conversion total hip arthroplasty for early failure following unstable intertrochanteric hip fracture: what can patients expect?

To report surgical outcomes in patients treated with conversion total hip arthroplasty (CTHA) for early failure of cephalomedullary nails (CMNs). A retrospective review was conducted of CTHA for treatment of failed CMN within 1year of initial surgery for intertrochanteric (IT) hip fractures. The cohort was matched 1:5 to patients who underwent elective primary THA (PTHA). Patient demographics, mechanism of CMN failure, surgical outcomes, and complication rates were assessed. 22 patients met criteria with a mean time to failure of 145days. Modes of failure included: lag screw cut-out with superior migration (9, 40.9%), or medialization (8, 36.4%), and aseptic nonunion with implant failure (2, 9.0%) and without implant failure (3, 13.6%). Fourteen of the patients (63.6%) had acetabular-sided damage secondary to lag screw penetration, all in the screw cut-out groups. Patient demographics were similar between cohorts. Compared to PTHA, CTHA patients had increased operative time, blood loss, LOS, and readmission rates. After IMN failure, the operative leg was shorter than the contralateral leg in all cases. CTHA restored leg lengths to < = 10mm in 15 (68.1%) of patients, with an average leg length discrepancy after CTHA of 6.7mm. CTHA patients had increased rates of overall surgical complications and medical complications, specifically anemia (all p < 0.01). Tranexamic acid was used less often in the CTHA group (p < 0.01). Rate of periprosthetic joint infection (PJI), dislocation, and revision were all higher in the CTHA, though did not reach statistical significance. The majority (77.3%) of CMN implant failure for nonunion within 1year was due to screw cut-out. CTHA is a salvage option for early failed IT hip fracture repair, but expected surgical outcomes are more similar to revision THA than primary THA, with increased risk of readmission, longer surgery and LOS, increased blood loss, and higher complication rates. III, Retrospective comparative study.

The intraoperative use of a calliper predicts leg length and offset after total hip arthroplasty. Component subsidence influences the leg length

BackgroundThe purpose of total hip arthroplasty (THA) post-surgery and proper physiotherapy is positive recovery for the patient. Consideration is given to hip replacement biomechanics by ensuring no discrepancies in limb length (LL) and a stable prosthesis. Therefore, the patient must have proper preoperative planning and communication and a clear understanding of what to expect.MethodsA prospective series of 59 THA operated by a single surgeon via Hardinge approach was studied, using an intraoperative calliper (CAL) to predict the change of LL and offset. We compared the results of the intraoperative changes before and after THA implantation with the reference of these values on anteroposterior x-ray pelvis. The importance of leg length balance and a good offset restoration is questioned, and the effect of component subsidence on leg length is considered.ResultsThe average preoperative leg length discrepancy was −6.0 mm, postoperatively +3.6 mm. There was a strong correlation between the CAL measurements and the values on the x-ray (LL, r=0.873, p<0.01; offset, r=0.542, p<0.01). Reliability is better for limb length than for offset. These results are comparable within the literature and the statistical results from other studies reviewed. In addition, we evaluate the importance of subsidence of the prosthesis components for long-term results.ConclusionThe intraoperative use of CAL gives excellent results in predicting the final LL and offset after THA. Considering subsidence of prosthesis components, a target zone around +5 mm might be more suitable for leg length directly postoperatively. Moreover, surgeons must discuss the topic of leg length discrepancy (LLD) intensively with the patient pre-operatively.Level of evidenceLevel 4, prospective cohort study

Two year follow up of supercapsular percutaneously assisted total hip arthroplasty

BackgroundDislocation after primary total hip arthroplasty (THA) has an incidence of 2–3%. Approximately 77% of dislocations occur within the first year after surgery. The SuperPATH technique is a minimally invasive approach for THA that preserves soft tissue attachments. The purpose of this study is to describe the dislocation rate at 1 year after SuperPATH primary THA.MethodsAll elective primary THAs performed by the senior author using the SuperPATH approach. Exclusion criteria were acute femoral neck fracture, revision surgery, or malignancy. There were 214 of 279 eligible patients available for telephone interviews (76.7%). Medical records were reviewed for secondary outcomes including early and late complications, cup positioning, distance ambulated on postoperative day one, discharge destination, and blood transfusions.ResultsMean age at surgery was 64 ± 10.8 years and mean time to telephone follow up was 773 ± 269.7 days. There were 104 female and 110 male patients. There were zero dislocations reported. Blood transfusions were performed in 3.7% of patients, and 75.7% were discharged to home at an average of 2.3 ± 1.0 days. Cup position averaged 43.6 ± 5.2° abduction and 20.9 ± 6.2° anteversion, with an average leg length discrepancy of 3.6 ± 3.32 mm. Complications included three intraoperative calcar fractures, one periprosthetic femur fracture, one early femoral revision, three superficial infections, and one instance of wound necrosis.ConclusionSuperPATH approach is safe for use in primary THA resulting in a low dislocation rate.

Concomitant intramedullary nailing and plate augmentation as a single-stage procedure in treating complicated nonunited femoral shaft fractures

Background and Purpose: Complicated femur fracture represents a major challenge for the orthopedic surgeon, with failed internal fixation, nonunion with broken intramedullary nail (IMN), and infected nonunion among the complications. Mechanical instability, as well as the poor biological environment, is considered as a concern when treating these cases. The purpose of this study was to evaluate concomitant IMN and plate augmentation as a single-stage procedure for the management of multiply operated nonunited femoral shaft fractures. Materials and Methods: Between January 2015 and May 2018, nine patients (eight men) with an average age of 40.8 years (range 25–70) diagnosed as nonunion femoral fractures after an average of four previous surgeries (range 2–6). All patients were available for follow-up with an average of 22 months (range 12–36). Results: The average time for fracture union was 6.7 months (range 3–12); five patients needed bone grafting to compensate for the bone defect encountered during the initial procedure, and two patients required secondary bone grafting after 6 months follow-up. Two patients presented with surgical site infection which was treated by antibiotics and daily dressing. The average leg length discrepancy at last follow-up was 1 cm (range 0.5–1.5). No patient had a metalwork failure or needed removal of the implants. Conclusion: In treating complicated multiply operated nonunited femoral shaft fractures, we believe that this technique can provide a robust mechanical foundation as well as an improved biological environment for such nonunited fractures to heal.

Scoliosis Caused by Limb-Length Discrepancy in Children.

Study DesignSingle-center retrospective study in pediatric patients.PurposeThe purpose of the study was to investigate the effects of the presence and severity of leg-length discrepancy (LLD) on scoliosis in children.Overview of LiteratureLLD is a common orthopedic problem that can result in standing imbalance, low back pain, and stress fractures. It may cause structural changes in the spine over time, but the exact effect of LLD on scoliosis is unknown.MethodsThe subjects were 23 children with LLD ≥20 mm (range, 27–65 mm) treated at Nagoya University Hospital between 2007 and 2017. Whole spine posteroanterior standing radiographs and whole lower limb radiographs in a supine position were recorded. Data were collected for demographics, LLD, Cobb angle, pelvic obliquity, and Nash/Moe index. Scoliosis was defined as a Cobb angle ≥10°. Leg length was measured from the top of the femoral head to the middle of the tibial plafond, and LLD was defined as the difference between the left and right leg lengths.ResultsThe patients (nine males and 14 females) had a mean age of 14.0 years (range, 5–18 years). The average LLD was 44.3±17.2 mm, with LLDs of 20 to 39 mm, 40 to 59 mm, and ≥60 mm in 13, five, and five subjects, respectively. The average Cobb angle was 13.0°±7.0°, and 15 subjects (65%) had scoliosis. Convexity of the scoliosis was to the short leg side in all cases. The Cobb angle was significantly related to the severity of the LLD (R=0.736, p<0.01), pelvic obliquity (R=0.966, p<0.01), and Nash/Moe index (p<0.05).ConclusionsLLD is a common pediatric condition that can cause scoliosis of the spine. Severe scoliosis may develop if the LLD is ≥30 mm. Long-term studies are needed to examine the effect of LLD resolution on the elimination of scoliosis.

External fixation-assisted reduction for the treatment of neglected hip dislocations with limb length discrepancy: a retrospective study of 13 cases

BackgroundThe purpose of this study was to evaluate a new method for treating neglected hip dislocation with limb length discrepancy by using external fixation-assisted pre-reduction.MethodsThirteen patients admitted between January 2010 to February 2018 with a mean duration from injury to surgery of 5.0 ± 2.1 months and an average preoperative leg-length discrepancy of 7.7 ± 2.3 cm were enrolled in this study. The dislocation and associated acetabular fracture type, clinical outcomes and residual limb length discrepancy were evaluated.ResultsAll patients had posterior dislocations, and nine patients presented with acetabular fractures and were followed-up for at least 12 months. The average traction duration of external fixators was 28.8 ± 8.0 days and all patients received second-stage open reduction and internal fixation. Six patients showed residual limb length discrepancy within 2 cm. Patients showed significant improvement in hip function and pain relief. Complications including avascular femoral head necrosis and osteoarthritis occurred in three patients.ConclusionEffective correction of limb length discrepancy and improved function were observed in patients with neglected hip dislocations and limb equality using traction by external fixation combined with second-stage open reduction. Further follow-up is required to determine long-term outcomes.

Modifications of the pirogoff amputation technique in adults: A retrospective analysis of 123 cases

BackgroundThe Pirogoff amputation (1854) was initially developed to provide full-weight-bearing stumps and therefore allow a short ambulation without prosthesis. Modifications of the original technique including Boyd (1939) and the “Modified Pirogoff” were developed, which further reduced complications and improved the outcome. However, the current evidence regarding the techniques is scarce. The functional outcome, survivorship and complication rates are unknown. It was the purpose of this study to expand the knowledge with a retrospective case series and ultimately summarize and analyze the data with a systematic review. MethodsA retrospective study of the Boyd procedures from our institution between 1999 and 2018 was performed. Outcome was determined based on the PLUS-M Score (Prosthetic Limb Users Survey of Mobility). Survivorship (absence of more proximal amputation), postoperative leg-length discrepancy, time to early fusion and time to mobilization were also evaluated. Finally, in the second part of the study, the results were integrated in a systematic review, which followed the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines. The quality of all the studies were then assessed using the Joanna Briggs Institute Critical Appraisal Checklist (JBI CAC). ResultsA total of 123 procedures including 115 patients, with an average follow-up of 45 months (range, 10–300 months) could be included. A very good or good function could be achieved in 85 (69%) patients. The mean survivorship was 82.1% (range 46%–100%). In four studies, including our series, all patients remained with a functional stump at the latest follow-up. The calculated average leg-length discrepancy was 2.5 cm. ConclusionThe “Modified Pirogoff” and Boyd amputation techniques can achieve favourable long-term functional outcome in cases of irreparable foot conditions such as osteomyelitis or trauma. Patency of the posterior tibial artery is an indispensable condition to elect for these surgical techniques. Presence of neuropathy does not preclude this amputation level. With proper patient selection, a maximal survivorship of the stump with treatable minor complications can be achieved.Level of Evidence: IV.

Long-term results and comparison of the Green-Anderson and multiplier growth prediction methods after permanent epiphysiodesis using Canale's technique.

PurposeThe aim of the study was to evaluate the accuracy and radiographic outcomes of Canale’s method in patients with idiopathic leg-length discrepancy (LLD) following percutaneous epiphysiodesis. The accuracy of two common growth prediction methods was assessed.MethodsA total of 18 patients with 26 affected bones (eight distal femur, two proximal tibia, five combined) were clinically and radiologically analyzed after reaching skeletal maturity. We compared the final effect of epiphysiodesis at maturity with the expected effect of epiphysiodesis before surgery; these measures were calculated using the Green-Anderson and multiplier methods, respectively. We furthermore compared pre- and postoperative frontal and lateral plane radiographs.ResultsThe average LLD was 21.2 mm before surgery and 7.9 mm after epiphysiodesis. The final effect of both methods was not significantly different compared with the expected effect of epiphysiodesis before surgery. However, the prediction by the Green-Anderson method was closer to the definitive epiphysiodesis effect. The frontal plane radiographic deformity parameters did not change significantly after epiphysiodesis. The postoperative sagittal plane radiographic deformity parameters were in the normal range.ConclusionThe Canale technique is a reliable method to reduce LLD in children. With regards to growth prediction, the Green-Anderson method using bone age seems to be more accurate than the multiplier method using chronological age. However, a relative over-estimation was observed with both methods in several cases, which might result in an insufficient correction.Level of EvidenceIV, Therapeutic study

Orthopaedic Management of Leg-length Discrepancy in Proteus Syndrome: A Case Series.

Proteus syndrome (PS) is a rare mosaic disorder comprising asymmetric bony and soft tissue overgrowth leading to significant morbidity. Placement of growth inhibition hardware with subsequent epiphyseal arrest improves leg-length and angular deformities in pediatric patients without PS. The purpose of this study was to review the surgical approach and present outcomes, complications, and recommendations in 8 patients with PS and leg-length discrepancy (LLD). We conducted a retrospective chart review of 8 patients with PS whose primary reason for surgery was LLD. Patients were eligible if they met clinical diagnostic criteria for PS and if the National Institutes of Health team performed at least 1 of their surgical interventions between 2005 and 2015. Surgical techniques included growth inhibition, with tension band plates, applied ≥1 times, and epiphyseal arrest. Eight patients, followed for an average of 4.6 years (range, 1.0 to 7.1 y) after the index procedure, were included in this analysis. Average age at first LLD surgery was 9.4 years (range, 6.1 to 13.6 y); the average LLD was 3.4 cm (range, 0.4 to 7.0 cm) at presentation, and 5.0 cm (range, 1.8 to 10.0 cm) at the time of the first LLD surgery. Participants underwent 23 total surgeries (range, 1 to 5 per patient) and 7 patients have completed surgical intervention. For the 7 patients who did not require overcorrection the average LLD at the last clinical encounter was 2.6 cm (range, 0.6 to 7.2 cm). We encountered 2 complications: 2 patients developed mild knee valgus, which responded to standard guided growth techniques. This case series suggests that growth inhibition and epiphyseal arrest in children with PS can reduce LLD with few complications. Careful monitoring, rapid mobilization, deep venous thrombosis prophylaxis, and sequential compression devices were also integral elements of our surgical protocol. Level IV.

Knee Arthrodesis Outcomes After Infected Total Knee Arthroplasty and Failure of Two-stage Revision With an Antibiotic Cement Spacer.

Background:Reinfected total knee arthroplasty can be managed with a second two-stage exchange or a knee arthrodesis procedure.Methods:Twenty-three patients with knee arthrodesis after failed exchange arthroplasty for infection were reviewed. Patients were managed with a staged protocol of implant extraction, débridement, and implantation of an antibiotic spacer, with subsequent arthrodesis. Follow-up averaged 40.4 months, with a minimum of 1 year.Results:Bony union with eradication of infection was achieved in 20/23 knees. Sixteen of the 20 patients were able to ambulate with minimal pain. The average time to union was 11.3 months, and the average leg length discrepancy was 4.85 cm. The average Knee Society Score after arthrodesis was 44, and the average visual analog scale pain score was 1.73. Three patients underwent above-knee amputation.Discussion:Knee arthrodesis performed for persistent periprosthetic infection allowed for eradication of infection and union in 87% of the patients, creating a stable knee fusion.

Direct Leverage for Reducing the Femoral Head in Total Hip Arthroplasty Without Femoral Shortening Osteotomy for Crowe Type 3 to 4 Dysplasia of the Hip

BackgroundA number of methods for reduction in high hip dislocation in total hip arthroplasty (THA) are time-consuming and laborious, and require great surgical skills. This study aimed to introduce a new reduction technique to achieve rapid, safe, and easy reduction in high hip dislocation. MethodsWe retrospectively reviewed 74 THA patients (82 hips; 44 women, 30 men) with severe hip dysplasia who underwent direct leverage using a Hohmann retractor into the anatomical acetabulum without femoral shortening osteotomy between September 2007 and January 2014. Forty-nine hips were classified as Crowe III and 33 hips were classified as Crowe IV. The mean follow-up period was 5.1 years (range 2-8). ResultsMean Harris Hip Score increased from 42.1 (range 24-71) before surgery to 89.9 (range 76-100) at final follow-up examination. The legs were lengthened by a mean of 3.0 cm (range 1.1-5.5) and 2.5 cm (range 1.1-3.5) in Crowe III hips and 3.6 cm (range 1.9-5.5) in Crowe IV hips postoperatively. The average leg-length discrepancy at the final follow-up examination was 0.4 cm (standard deviation 0.5 cm). One greater trochanteric fracture occurred during the hip reduction process. One patient developed femoral nerve palsies and recovered completely at 3 weeks postoperatively. ConclusionDirect leverage using the Hohmann retractor for the reduction in high hip dislocation in THA without femoral shortening osteotomy is simple, safe, and effective.

Orthopaedic management of leg length discrepancy in Proteus syndrome: a case series

Introduction Proteus syndrome (PS) is a rare mosaic disorder comprising asymmetric bony and soft tissue overgrowth leading to significant morbidity. Placement of growth inhibition hardware with subsequent epiphyseal arrest improves leg-length and angular deformities in pediatric patients without PS. The purpose of this study was to review the surgical approach and present outcomes, complications, and recommendations in 8 patients with PS and leg-length discrepancy (LLD). Methods We conducted a retrospective chart review of 8 patients with PS whose primary reason for surgery was LLD. Patients were eligible if they met clinical diagnostic criteria for PS and if the National Institutes of Health team performed at least 1 of their surgical interventions between 2005 and 2015. Surgical techniques included growth inhibition, with tension band plates, applied ≥1 times, and epiphyseal arrest. Results Eight patients, followed for an average of 4.6 years (range, 1.0 to 7.1 y) after the index procedure, were included in this analysis. Average age at first LLD surgery was 9.4 years (range, 6.1 to 13.6 y); the average LLD was 3.4 cm (range, 0.4 to 7.0 cm) at presentation, and 5.0 cm (range, 1.8 to 10.0 cm) at the time of the first LLD surgery. Participants underwent 23 total surgeries (range, 1 to 5 per patient) and 7 patients have completed surgical intervention. For the 7 patients who did not require overcorrection the average LLD at the last clinical encounter was 2.6 cm (range, 0.6 to 7.2 cm). We encountered 2 complications: 2 patients developed mild knee valgus, which responded to standard guided growth techniques. Conclusions This case series suggests that growth inhibition and epiphyseal arrest in children with PS can reduce LLD with few complications. Careful monitoring, rapid mobilization, deep venous thrombosis prophylaxis, and sequential compression devices were also integral elements of our surgical protocol. Level of evidence Level IV.

Clinical Results of Complex Subtrochanteric Femoral Fractures with Long Cephalomedullary Hip Nail.

PurposeGood results of the cephalomedullary nails have been reported in proximal femoral fractures recently. Based on length of nails and shape of screws fixed in a femoral head for proximal fragment fixation, the proper nail length was in dispute. The purpose of this study was to evaluate the clinical and radiological results of a long cephalomedullary hip nail for the treatment of comminuted subtrochanteric femoral fractures.Materials and MethodsTwenty-one consecutive patients with severe subtrochanteric femoral fractures who had undergone intramedullary fixation using long-PFNA II between March 2010 and March 2013 were followed-up for over 12 months. Their mean age was 64.8 years old (range, 43-85 years). Sixteen of 22 cases were high energy trauma. According to Seinsheimer's classification, 5 cases were type IV and 16 cases were type V. For radiological assessment, time to union, change of neck-shaft angle, sliding length, tip-apex distance (TAD) and leg length discrepancy (LLD) were measured. For clinical evaluation, a modified Koval index was investigated.ResultsMean operation time was 96 minutes. An average decrease of neck-shaft angle was 4.5°. The average sliding length of the helical blade was 4.2 mm. Average LLD was 3.0 mm, and TAD was 23.0 mm. Mean modified Koval index score at final follow-up was 4.6 points. All the 21 subtrochanteric fractures healed uneventfully on an average of 24.2 weeks (range, 18-30 weeks).ConclusionLong cephalomedullary hip nail provides excellent clinical and radiological outcomes in the comminuted subtrochanteric fracture.

Modern Techniques in Knee Arthrodesis

Knee arthrodesis serves as an option of salvage treatment for failed total knee arthroplasty procedures. Multiple different arthrodesis techniques exist that cater to the specific presentation of the failed total knee arthroplasty, the three most common techniques being intramedullary nails, external fixation, and compression plates. This review aims to present recent findings of knee arthrodesis procedures regarding the indications, outcomes, and prognostic factors as well as a general description of the technical aspects, advantages, and disadvantages of each specific knee arthrodesis technique. Data was collected and compared between the individual techniques based on fusion rate, average time to fusion, average complication rate, types of complications, average postoperative recurrent infection rate, and average leg length discrepancy. Finally, the author’s preferred technique based on clinical experience is presented.

Modern Techniques in Knee Arthrodesis

Knee arthrodesis serves as an option of salvage treatment for failed total knee arthroplasty procedures. Multiple different arthrodesis techniques exist that cater to the specific presentation of the failed total knee arthroplasty, the three most common techniques being intramedullary nails, external fixation, and compression plates. This review aims to present recent findings of knee arthrodesis procedures regarding the indications, outcomes, and prognostic factors as well as a general description of the technical aspects, advantages, and disadvantages of each specific knee arthrodesis technique. Data was collected and compared between the individual techniques based on fusion rate, average time to fusion, average complication rate, types of complications, average postoperative recurrent infection rate, and average leg length discrepancy. Finally, the author’s preferred technique based on clinical experience is presented.

Thermal epiphysiodesis performed with radio frequency in a porcine model

Background and purpose — Current techniques for epiphysiodesis involve opening of cortical windows; use of staples, screws, and tension devices; and fusion with curettes or drills. Complications may have serious consequences. There is a need for a more reliable, precise, and less traumatic procedure that overcomes the known complications from existing techniques. We analyzed a new epiphysiodesis technique using radio-frequency ablation (RFA) in a porcine model.Methods — Six 35-kg and two 25-kg immature pigs were used. 1 hind leg of each animal was randomly selected and the proximal tibia growth plate was ablated laterally and medially. The contralateral leg was used as a control. MR images were obtained immediately after the ablation and 12 weeks later for 6 animals, and 24 weeks later for the other 2 animals. CT was done for the 2 animals that were followed for 24 weeks for proof of bone bridges.Results — Both tibias were equal in length initially. At the 12-week follow-up, there was an average leg length discrepancy of 3.9 mm (95% CI: 3.0–4.8), and at 24 weeks the difference was 8.4 mm and 7.5 mm. No damage to the adjacent tissue was found. Bone bridges and physeal closure were found after 24 weeks. The pigs showed no discomfort after the intervention.Interpretation — We found RFA to be feasible for epiphysiodesis in a pig model. The method is minimally invasive and recovery may be quick compared to conventional methods. We recommend that the method should be tested in larger-scale safety studies before clinical application.

Leg length discrepancy in patients with slipped capital femoral epiphysis

Background and purpose Leg-length discrepancy (LLD) can be a sequela of slipped capital femoral epiphysis (SCFE). We tried to identify factors that affect the development of LLD following SCFE.Patients and method We evaluated 85 patients who had been treated using percutaneous screw fixation. The average age of the patients at the time of surgery was 12 (8–16) years. The relationship of LLD and various clinical and radiographic parameters was evaluated: the degree of slip, articulotrochanteric distance (ATD), and articulotrochanteric distance difference (ATDD) (healthy side minus the side with SCFE). We assessed the relationship between ATDD and LLD based on scanogram.Results The average LLD was 1.4 (0.1–3.8) cm at 6 (2–15) years postoperatively. 48 of 85 patients had an LLD of greater than 1 cm and 10 patients had an LLD of greater than 2 cm. There was a correlation between the magnitude of LLD and the severity of the slip. There was no statistically significant correlation between LLD and the stability of the slip, age, BMI, sex, or race. There was a significant correlation between LLD and ATDD.Interpretation Patients with a high degree of slip are prone to develop clinically significant LLD. Although ATDD does not give the exact LLD, it can be used as a primary measurement, which should be supplemented with scanogram in cases of clinically significant differences in length.