Effects of Complex Korean Medicine Treatment on a Patient with Knee Pain and Ankylosis Following a Distal Femur Osteotomy: A Case Report

Where Are We Now? The information in the study by Cameron et al. [1] represents an excellent addition to the current literature on distal femoral osteotomies that is largely dominated by medial closing-wedge techniques. Currently, lateral opening-wedge and medial closing-wedge distal femoral osteotomies have been effectively used to provide substantial relief in painful knees with significant valgus (>10° to 15° between the anatomic and mechanical axes). While medial closing-wedge high tibial osteotomies have also been utilized in these patients, this approach has produced less reliable pain relief and may cause iatrogenic joint line obliquity and subsequent instability [2]. Fortunately, multiple studies have demonstrated good outcomes following varus-producing distal femoral osteotomies including TKA conversion rates of 6.1% at 10 years [4] and Knee Injury and Osteoarthritis Outcome Score improvements from 31 preoperatively to 69 postoperatively [3]. Controversy exists, however, regarding the most reliable approach to the varus-producing distal femoral osteotomy, specifically, medial closing-wedge versus lateral opening-wedge. Prior data have suggested an increased rate of hardware irritation, delayed osteotomy healing and more meticulous preoperative planning with the lateral opening-wedge distal femoral osteotomy technique [3, 5]. However, the lateral opening-wedge distal femoral osteotomy may have advantages including a single osteotomy cut, possible reduced neurovascular risk, and improved correction control due to increased flexibility during intraoperative corrective degree adjustments. Other questions exist including: (1) What are the specific indications and subsequent outcomes of the varus-producing distal femoral osteotomy for joint restoration and valgus gonarthrosis? (2) Which distal femoral osteotomy technique (lateral opening-wedge versus medial closing-wedge) may optimize these outcomes? Where Do We Need To Go? The current study addresses many of the aforementioned controversies. Specifically, this article documented a 3% nonunion rate with no delayed unions [1], which is significantly less than a prior study suggested [3]. This nonunion occurred in the arthrosis subgroup and was ultimately treated with conversion to TKA. All other patients (30/31) demonstrated complete radiologic union by 6 months postoperatively. These data suggest that current concerns regarding distal femoral osteotomy nonunion may be overstated or overemphasized as a potential postoperative complication. Alternatively, concerns regarding increased reoperation rate and hardware irritation following lateral opening-wedge distal femoral osteotomy appear to be well founded. The current study documented a 52% postoperative reoperation rate. Specifically, hardware removal was required in 19% of the patients. The current data also suggests that the theoretically improved intraoperative correction that is afforded by the lateral opening-wedge distal femoral osteotomy technique does not actually occur in practice. In fact, only 47% of patients that had postoperative alignment radiographs were within the correction goal of ± 3° from the desired neutral mechanical axis. Fortunately, however, this study effectively highlighted the safety of the lateral opening-wedge distal femoral osteotomy technique as no postoperative infections, nerve palsies, or wound complications were noted. Improved outcomes were also seen in both the joint preservation and arthritis groups. Notably, 5-year survivorship was much higher in the joint preservation group (92%), as compared to the arthritis group (74%), suggesting the utility of the lateral opening-wedge distal femoral osteotomy technique in this specific patient subpopulation. However, as this is the first article to evaluate these subpopulations, it is difficult to draw rigid conclusions at this time. These controversies leave the following questions remaining for future study: (1) What patient populations and specific knee pathologies may be optimally treated with isolated or concomitant distal femoral osteotomy with specific focus on chondral restoration versus already present arthrosis? (2) Are lateral opening wedge and medial closing wedge distal femoral osteotomies equal or should one be preferentially used? (3) How can we optimize the osteotomy correction accuracy? How Do We Get There? The data by Cameron et al. [1] aids in addressing the first question regarding which population is most effectively treated with distal femoral osteotomy by documenting that good clinical outcomes can be obtained following a lateral opening-wedge distal femoral osteotomy—particularly in patients in whom concomitant joint restoration procedures are utilized. I would like to congratulate these authors on stratifying the two separate populations, as this represents a crucial contribution in recognizing these distinctly different patient populations and provides preliminary data that may aid in answering this initial question. Further study is necessary in this area including identifying which specific procedures are aided by concomitant distal femoral osteotomy and which are not. Prior studies regarding a high tibial osteotomy for gonarthrosis and joint preservation have suggested that increased valgus correction may be important in the setting of moderate to severe arthrosis, while neutral correction may be optimal in the setting of chondral restoration. Future studies regarding the correction effect following distal femoral osteotomy on patient outcomes with similar pathology in the lateral compartment will be important. While the current study unquestionably adds to the previous paucity of data regarding outcomes and complications following distal femoral osteotomy and therefore assists in answering the second question regarding which distal femoral osteotomy technique may be optimal, the small study size remains an issue. Future large-scale studies are necessary to address this significant limitation. Since distal femoral osteotomies are not exceedingly common, a multicenter study design would address this limitation. This multicenter study design may enable a direct comparison of lateral opening-wedge distal femoral osteotomy to medial closing-wedge distal femoral osteotomy, which could help address this significant controversy. Lastly, obtaining accurate osteotomy correction following distal femoral osteotomy and high tibial osteotomy continues to represent a significant complication. The current article highlights this difficulty despite the use of lateral opening-wedge distal femoral osteotomy that is suggested to allow a more accurate correction. This data suggests that using the lateral opening wedge distal femoral osteotomy technique may not represent the best answer to the aforementioned third question regarding which technique optimizes osteotomy correction accuracy. Further study is clearly required in this specific area. Utilization of computer-assisted navigation for correction accuracy has produced promising results [6] in this regard. However, no data exists to identify the most accurate correction method. Future studies should allow direct comparison of correction accuracy among lateral opening-wedge distal femoral osteotomy versus medial closing-wedge distal femoral osteotomy and computer assisted navigation versus intraoperative alignment guides. The data obtained from these future studies will undoubtedly improve our understanding of and ability to treat patients with valgus malalignment and lateral compartment focal chondral pathology, meniscal deficiency or generalized gonarthrosis.

Conventional Western medicine (CWM) and traditional Chinese medicine (TCM) have different approaches and lead to different practices in experimental design, research methodology, regulation, and standards. TCM emphasizes on the optimal or holistic health. In contrast, CWM is an allopathic medicine primarily based on anatomy, biology, biochemistry, molecular biology and modern technology, and rejects the concept of invisible substances and quantum entanglement. Consequently, CWM emphasizes on abnormal lab tests or obvious diseases. In the early 1970s, TCM and acupuncture quickly emerged as an alternative to CWM as Westerners explored new TCM concepts while questioning the side effects of CWM. Many countries accept traditional acupuncture as a legal alternative medical practice. Some CWM physicians nowadays are more enthusiastic and are receptive to learning and practicing acupuncture. The common goal of CWM and TCM is to enhance human health, but problems arise over differences in approach. As a response to some Western journal papers that failed to validate the real acupuncture effect because of their incorrect methodologies and their ignorance of the holistic acupuncture approaches, the authors hereby present a group of case studies to demonstrate the real and unique effects of genuine acupuncture. The objective was to explore the clinical effects of acupuncture for knee pain. Thirty-six patients with knee pain were divided into five groups based on age. Holistic TCM diagnosis was performed at the beginning of each case and then made a personalized acupuncture treatment prescription according to the root of illness found by the diagnosis. The symptoms and signs were recorded before and after every treatment, and the treatment effects were assessed based upon the self-reported feeling and the observed changes of the patient following the numeric rating scale (NRS). The results were summarized after the completion of the minimal 5 acupuncture treatments or the standard 10 acupuncture treatments. Among the 36 patients who participated in the cases studies, 17 patients reported a complete healing for knee pain (47.2%). About 60 kinds of illness other than knee pain were improved (98.9%) and the complete healing rate was about 44.2%. This leads to the conclusion that TCM acupuncture is remarkably effective in treating knee pain. TCM and CWM share a common goal in promoting the health of human being. The efficacy of TCM acupuncture in treating knee pain shouldn’t be denied or distorted.

To compare the results of two different ways of distal femoral osteotomy stabilization in patients suffering from genuvalgum: internal fixation with plate, and casting. In a non-randomized prospective study, after distal femoral osteotomy with the zigzag method, patients were divided into two groups: long leg casting, and internal fixation with blade plate. For all patients, questionnaires were filled to obtain data. Information such as range of motion, tibiofemoral anatomical angle and complications were recorded. 38 knees with valgus deformity underwent distal femoral supracondylar osteotomy. (8 with plaster cast and 30 with internal fixation using a blade plate). Preoperative range of motion was 129±6° and six months later it was 120±14°. The preoperative tibiofemoral angle was 32±6°; postoperative tibiofemoral angles were 3±3°, 6±2°, and 7±3° just after operation, six months, and two years later, respectively. Although this angle was greater among the group stabilized with a cast, this difference was not statistically significant. In postoperative complications, over-correction was found in five, recorvatom deformity in one, knee stiffness in three and superficial wound infection was recorded in three knees. There is no prominent difference in final range of motion and alignment whether fixation is done with casting or internal fixation. However, the complication rate seems higher in the casting method.

Distal femoral varus osteotomy may be used to treat valgus knee malalignment or to protect a knee compartment in which cartilage restoration surgery (such as osteochondral or meniscus allografting) has been performed. Medial closing-wedge osteotomy has demonstrated good success in treatment of osteoarthritis in published series, but few studies have evaluated distal femoral lateral opening-wedge osteotomy in terms of correction of deformity, pain and function, and survivorship. (1) Does lateral opening-wedge osteotomy lead to accurate correction? (2) What pain and function levels do patients experience after lateral opening-wedge osteotomy? (3) What are the nonunion, complication, and reoperation rates after lateral opening-wedge osteotomy? Between 2000 and 2010, we performed 40 distal femoral osteotomies. Two knees (two patients) underwent a medial closing-wedge osteotomy and were excluded from the present study. Thirty-eight knees (97%) in 36 patients were lateral opening-wedge varus-producing osteotomies; of those, 31 knees (82%) in 30 patients had followup at a minimum of 2years (mean, 5years; SD, 2; range, 2-12years) and comprised the study population. The indications for osteotomy included symptomatic lateral compartment arthritis with clinical valgus deformity or a cartilage or meniscal defect in the lateral compartment with clinical valgus alignment. The study population was stratified into two groups based on reason for osteotomy: patients with isolated symptomatic lateral compartment arthritis (arthritis group; 19 knees [61%]) and patients who underwent joint preservation procedures including osteochondral allograft transplantation or meniscal allograft transplantation (joint preservation group; 12 knees [39%]). Data collection from our institution's osteotomy database included patient demographics, lower extremity coronal alignment, and operative details. Pain and function were measured preoperatively and postoperatively using the International Knee Documentation Committee (IKDC) score. Time to radiographic union, complications, and reoperations were recorded. Twenty-one of 31 knees had postoperative radiographic data available for review. Of these, seven of 15 knees in the arthritis group and three of six knees in the joint preservation group were within the correction goal of±3° from neutral mechanical alignment. In the arthritis group, the mean IKDC total score improved from 47 (SD, 15) preoperatively to 67 (SD, 10) postoperatively. In the joint preservation group, the mean IKDC total score improved from 36 (SD, 12) preoperatively to 62 (SD, 18) postoperatively. One nonunion occurred in the arthritis group. No postoperative complications were experienced. Ten knees in the arthritis group and six knees in the joint preservation group had additional surgery after the osteotomy, consisting primarily of hardware removal, arthroscopy for cartilage-related conditions, or conversion to arthroplasty. Survivorship at 5years, with conversion to arthroplasty as the endpoint, was 74% in the arthritis group and 92% in the joint preservation group. Lateral opening-wedge distal femoral osteotomy was less accurate in correction of valgus deformity than expected, but the procedure was associated with improved knee pain and function scores. Our clinical and radiographic results are comparable to published series evaluating medial closing-wedge distal femoral osteotomy. Achieving our desired correction of±3° from neutral alignment was clinically difficult. An improved method of preoperative templating and refinement of the intraoperative technique may improve this. Future studies with more patients and longer followup will provide clarity on this topic. Level IV, therapeutic study.

Changes in epiphyseal bone, subchondral bone plate and epiphyseal trabecular bone in surgically and chemically induced rat models of osteoarthritis

High density mineralised protrusions from the tidemark into hyaline cartilage in human joints

Objective To evaluate the preliminary outcomes of distal femoral extension osteotomy plus patellar tendon advancement for crouch gait in children. Methods From April 2009 to June 2012, distal femoral extension osteotomy plus patellar tendon advancement were performed for crouch gait in cerebral children with 10-30 degree fixed knee flexion contracture. A total of 16 cases (26 lower extremities) were enrolled with a mean follow-up period of 54 (48-65) months. There were 11 males and 5 females with an average age of 8.9 years (7.5-11.6). Cast immobilization was applied for 6 weeks post-operation. After cast removal, functional exercise was enforced and long leg night splint used for maintaining correction. Degree of fixed knee flexion deformity, popliteal angle, range of motion in knee joint, improvement of crouch gait, visual analogue score (VAS) of knee pain, strength of quadriceps, hamstring and musculus triceps surae, Insall-salvati index on lateral radiographic view and Wren modified crouch gait visual score by physicians were recorded and analyzed for outcome evaluation. Results The GMFCS levels were Ⅰ (n=0), Ⅱ (n=9), Ⅲ (n=7), Ⅳ (n=0) and Ⅴ (n=0). Iliopsoas release was implemented contemporarily in 6 lower limbs and achilles tendon lengthening in 10 lower limbs simultaneously. Crouch gait improved or disappeared in all cases. Compared with preoperative VAS scores of knee pain, the postoperative scores decreased significantly (P<0.05). Degree of fixed knee flexion deformity and poplital angle diminished significantly (P<0.01). Range of motion expanded in knee joints (P<0.01). Strength of quadriceps improved significantly (P<0.05). Strength of hamstring and musculus triceps surae showed insignificant changes. Insall-salvati index on lateral radiographic view diminished with patella alta disappeared in all cases. Two cases of transient sciatic nerve injury remitted through changing cast immobilization in a 20 knee flexion position and nerve nutrition supplementation. Two cases of incision infection were cured after dressing changing. And 3 cases had a mild displacement of distal femur, but osteotmy site remolded well without treatment. There was no instance of over-correction, knee recurvatum or cast pressure sore. Conclusions Distal femoral extension osteotomy plus patellar tendon advancement can effectively improve crouch gait, correct knee flexion deformity and patella alta, boost quadriceps strength and relieve knee pain. And the preliminary outcomes are excellent. Key words: Femur; Cerebral palsy; Gait

The lateral opening wedge distal femoral osteotomy (DFO) is an effective treatment for genu valgum to improve mechanical alignment, decrease lateral compartment loads, and decrease the risk of knee osteoarthritis. Multiple studies have utilized outcome scores assessing functional changes related to pain and joint stability, with a focus solely on knee pain and functional outcomes. The primary aim of this study was to evaluate patient-reported outcome measures (PROMs) that assessed knee function, pain, patient's perception of body image, and limb deformity-related quality of life, both preoperatively and at least 1-year postoperatively. In a retrospective review of nontraumatic genu valgum patients who underwent bilateral DFO, preoperative and postoperative radiographs were evaluated. Routinely collected preoperative and 1-year postoperative PROMs scores were analyzed, using the Knee Injury and Osteoarthritis Outcome Score Jr. (KOOS-JR) and the Limb Deformity-Modified Scoliosis Research Society (LD-SRS) score, in 72 limbs (36 patients): 7 men (19.44%) and 29 women (80.56%) with an average age of 35.34 ± 13.57 years. The mean follow-up time was 36.85 ± 24.43 months. Overall mechanical axis deviation, lateral distal femoral angle, and mechanical axis alignment angle were significantly improved after DFO in all patients. Both PROMs also improved significantly from preoperative to postoperative scores: LD-SRS (3.10 ± 0.56 vs 4.19 ± 0.44, respectively) and KOOS-JR (63.02 ± 19.25 vs 78.06 ± 16.29, respectively). This retrospective review suggests that bilateral lateral opening-wedge DFOs in patients with symptomatic valgus knee deformity may be associated with improved overall knee health, limb deformity-related quality of life, and patients' body image. Further study is needed.

Osteoarthritis (OA) of the ankle with an unknown etiology (primary OA) is rare, whereas a secondary OA due to a known cause is not uncommon. OA of the knee can, when it progresses, change the alignment of the whole extremity including the ankle joint. Since we had observed in patients coming for OA knee surgery coexisting OA in the ankle joint, our objective of this study was to assess the prevalence of abnormal alignment and degenerative changes in the ankle joint and to determine if degenerative changes in the knee and ankle correlated. These aims were assessed retrospectively, utilizing mechanical axis (MA) radiographs of subjects with knee OA prior to surgery. This retrospective study consisted of 104 patients who had undergone surgery of the knee due to OA. A musculoskeletal radiologist and an orthopedic surgeon reviewed in consensus the preoperative and postoperative MA radiographs. We analyzed and measured the tibiofemoral (TF) angle, the mediolateral tibial translation, the deviation of the MA, the tilt of the talocrural joint and the degree of OA in the knee and ankle. The severity of OA of the TF joint correlated with the preoperative TF translation and moderately with the deviation of the MA and abnormal TF angle. Of the 104 patients, 30 showed coexisting OA of the ankle: the greater the tilt in the ankle, the more degenerative were the changes in the joint. The MA was corrected with surgery from a mean preoperative 5.4 degrees varus to a postoperative mean 1.2 degrees valgus, and the ankle tilt was changed significantly at the same time. Ankle OA and tilt were not uncommon in our patients with knee OA. The assumption that associations may exist between knee and ankle OA and joint malalignment was confirmed.

Objectives: A DFO can be performed via two techniques: a lateral opening wedge (LOW) osteotomy and a medial closing wedge (MCW) osteotomy. Small case series have looked at how leg length is affected by a lateral opening wedge DFO, however, there is a lack of research comparing these leg length changes to medial closing DFO. Additionally, no studies have presented a model for predicting the leg length changes that will occur following DFO of either technique. Given that limb length differences can lead to accelerated osteoarthritis, back pain, hip pain, and other issues, being able to predict which technique can help prevent this pathology without a secondary procedure would be an important finding. Finally, the medial closing wedge osteotomy can allow for immediate weight-bearing while the lateral opening wedge does not and typically has associated cost with bone grafting. Therefore, we designed this study to validate a tool designed to predict leg length changes after distal femoral osteotomy (DFO) and compare changes following medial closing wedge (MCW) and lateral opening wedge (LOW) techniques. Methods: A collaborative retrospective review was performed of patients from Rush and Mayo Clinic databases who received a DFO and had full-length standing radiographs both pre-and postoperatively. For each preoperative radiograph, the region on the medial (for LOW) or lateral (for MCW) distal femur cortex that would be the “hinge point” during DFO was identified. The distances from the center of the femoral head to the hinge point (“A”), from the hinge point to the center of the tibial plafond (“B”), and the resultant angle at the hinge point (“α”) were measured (Figure 1). Figure 2 demonstrates the equation used to plot a graph of the predicted leg length changes corresponding to the change in α angle produced by DFO. Final leg length was calculated on postoperative radiographs, and the difference between predicted and true leg length changes was compared using paired Wilcoxon signed rank exact tests. Results: 10 MCW and 10 LOW patients were included. For both LOW (n=10) and MCW (n=10) osteotomies, the predicted leg length change was equivalent to the true change measured on postoperative radiographs (LOW P=0.16; MCW P=0.85). LOW DFO’s had 5.10 ± 2.77 mm (range: 1.45-10.87 mm) of leg lengthening, compared to 2.61 ± 1.25 mm (range: 0.50-4.56 mm) of leg shortening (p&lt;0.001) for MCW (Figure 3). On average, there was 0.85 mm of lengthening (range 0.5-1.3 mm) for every 1° of mechanical axis correction with LOW DFO, compared to 0.45 mm of shortening (range: 0.1-1.4 mm) per 1° of MCW correction. Conclusions: This study presents a tool to accurately and reliably predict the leg length changes seen after both medial closing and lateral opening wedge DFO’s. Knowing what leg length changes to expect with each DFO technique is a useful tool that surgeons can utilize during surgical planning. Preoperative radiographic imaging can be used to predict leg length change following DFO with high reliability and accuracy. Surgeons can expect approximately 0.85mm of lengthening per 1° of DFO correction when performing LOW, compared to 0.45mm of shortening per 1° correction for MCW osteotomies.

To assess the outcomes and complication rates of early weightbearing (either immediate weightbearing as tolerated or partial weightbearing) and delayed weightbearing (an initial period of non-weightbearing or toe-touch weightbearing) following distal femoral osteotomy (DFO). A systematic literature search using PubMed, Embase and Cochrane Reviews was performed. Inclusion criteria were studies reporting on outcomes and complications after DFO with a minimum 1-year follow-up. Methodologic quality of studies was assessed using the methodological index for non-randomised studies (MINORS) criteria. Data collection included incidence of nonunion, delayed union, loss of fixation or deformity correction, knee stiffness, venous thromboembolism (VTE) and patient-reported outcome measures (PROMs). Meta-analysis was performed utilising random effects models, with statistically significant results denoted by a p-value < 0.05. Twenty-six studies (23 level IV and 3 level III) with 814 patients were included (mean age 42 years, mean follow-up 5.2 years). All but one study (25/26 [96.2%]) had moderate quality methodology. Statistical comparison was limited by low event frequency, and thus no statistically significant associations were identified, and p-values were omitted. The overall complication rates were nonunion 2.5% (95% confidence interval [CI] 1.6%-3.8%), delayed union 0.6% (95% CI 0.1%-3.3%), loss of fixation or deformity correction 1.4% (95% CI 0.5%-3.5%), knee stiffness 2.9% (95% CI 1.4%-6.1%), VTE 0.9% (95% CI 0.3%-2.3%). Validated PROMs were reported in 11 of 26 studies (42%) using heterogeneous instruments, precluding quantitative pooling and meta-analysis. There were relatively low overall mean rates of delayed union, nonunion, loss of fixation or deformity correction, and VTE after DFO, regardless of an early or delayed post-operative weightbearing protocol. Due to limited comparative data and the risk of selection bias, definitive conclusions cannot be drawn regarding the safety of early weightbearing after DFO, underscoring the need for prospective controlled studies. Level IV.

Anterior cruciate ligament (ACL) injury sometimes is associated with genu valgum. Valgus malalignment poses concerns due to its potential to increase strain on the ACL, thereby elevating the risk of osteoarthritis in the lateral compartment of the knee. However, lacune still exists regarding the concomitant reconstruction of ACL and distal femoral osteotomy in ACL-deficit knee with genu valgum. The present case report aims to fill this gap by presenting a rare case of a young patient with a symptomatic ACL deficit knee and femur-originated genu valgum. A young male presented with bilateral genu valgum at our clinic with pain and instability of the right knee following a sports injury for 1 year. The anterior drawer, Lachman, pivot shift, and McMurray test were positive in physical examination. The surgical intervention comprised lateral open wedge osteotomy of the distal femur, all-inside reconstruction of the ACL, and partial meniscectomy for the meniscal tear. Simultaneous ACL reconstruction with femur osteotomy offers favorable outcomes in patients presenting with genu valgum. This integrated approach minimizes hospitalization and rehabilitation periods. Meticulous planning and surgical techniques, including careful femoral tunnel placement, can mitigate potential complications like plate interference.

A 4-year-old, 3.9 kg spayed female bichon frise presented with persistent lameness following primary medial patellar luxation (MPL) surgery, including tibial tuberosity transposition, trochleoplasty and lateral imbrication. The physical examination indicated a grade IV MPL. Preoperative CT-based 3Dreconstructions revealed varus deformity of the distal femur, valgus deformity of the proximal tibia, internal rotation of the tibial tuberosity and bilateral moderate degenerative changes of the coxofemoral joints, with concurrent grade IV medial patellar luxation. The patient underwent revision surgery with distal femoral osteotomy (DFO), proximal tibial osteotomy (PTO) and Ridgestop placement to augment the medial trochlear ridge. To ensure precise intraoperative alignment, preoperative planning utilised virtual 3D planning and 3D printing to fabricate customised osteotomy surgical guides for both DFO and PTO. Postoperative follow-up revealed no further luxation, with stable weight-bearing ambulation. Radiographic analysis confirmed proper limb alignment and Ridgestop implant placement. Ridgestop could offer an effective treatment option for dogs with recurrent patellar luxation when combined with corrective osteotomy.

Varus-producing distal femoral osteotomy (DFO) is an established procedure to correct genu valgum in patients with osteoarthritis and gait abnormalities. DFO has also been proposed for the treatment of patellar instability in patients with valgus alignment. However, it is not known how DFO affects parameters associated with patellar instability. This study evaluated radiographic changes after DFO with variable degrees of correction on six cadaveric knees, with the hypothesis that improving mechanical alignment would improve radiographic parameters related to patellar instability. Controlled laboratory is the study design. Six lower-limb cadaveric specimens were obtained after approval by the Institutional Review Board. A lateral opening wedge DFO was performed on each specimen with correction blocks of 6, 10, and 14 mm. The mechanical axis, tibiofemoral angle (mTFA), distal femoral angle (mDFA), Caton Deschamps index (CDI), insall salvati index (ISI), tibial tubercle to trochlear groove distance (TT-TG), and patellofemoral congruence angle (PFCA) were measured on computed tomography (CT) scans at baseline and after each correction block. At baseline, a mean varus alignment of the limbs was observed (mTFA: 2.7 ± 2.8 degrees, mDFA: 87.6 ± 1.0 degrees). The baseline patellar height was normal (CDI: 0.9 ± 0.2, ISI: 1.0 ± 0.1). Statistically significant decreases in mechanical axis and TT-TG distance and increases in mDFA and mFTA were found with increasing block size. The TT-TG distance was decreased by -1.6 mm (95% confidence interval [CI]: -2.27 to -0.86), -3.8 mm (95% CI: -4.8 to -2.8), and -4.0 mm (95% CI: -5.4 to -2.7) with a 6, 10, and 14 mm block, respectively. No differences were observed in patellar height when measured with CDI or ISI after any block size. In a cadaveric model, DFO significantly affects the mechanical axis and TT-TG distance. Specifically, this study found a mean decrease in TT-TG of -3.8 mm when performing a 10 mm opening wedge osteotomy. No changes in patellar height were observed.

Distal femoral fractures are commonly treated with osteosynthesis.However, in older patients with osteoarthritis of the knee, acute primary total knee arthroplasty (TKA) may be performed to treat these fractures. Notably, no studies have documented the use of osteosynthesis in combination with distal femoral osteotomy (DFO) for treating distal femoral fractures in patients with knee osteoarthritis. This report presents the case of a 66-year-old woman with lateral compartment osteoarthritis accompanied by severe valgus knee deformity who underwent osteosynthesis for a distal femoral fracturecombined with medial closing-wedge distal femoral osteotomy (MCWDFO) to correct the knee valgus deformity. She experienced a distal femoral fracture (AO/OTA 33B1.1) of the right knee because of a fall. Before the injury, she exhibited a limp due to severe knee pain with some limitations in knee flexion. Non-weight-bearing radiographs of the entire lower extremity suggested a percentage mechanical axis (%MA) of 115%, indicating severe valgus deformity. On day nine after the injury, we performed osteosynthesis for the distal femoral fracture and conducted an MCWDFO to correct the right knee valgus deformity. After MCWDFO, the %MA was corrected to 70%. Partial weight-bearing was initiated three weeks postoperatively and progressed to full weight-bearing at six weeks. To facilitate bone healing, low-intensity pulsed ultrasound(LIPUS) was applied for three months after surgery. Bone union was successfully achieved by month five. Some medial knee pain persisted for six months after surgery; nonetheless, the patient could walk without a limp. We considered that the integration of MCWDFO with osteosynthesis could provide a treatment option for patients with distal femoral fractures and lateral compartment osteoarthritis.