Reconstruction of massive bone defects after femoral tumor resection using two new-designed 3D-printed intercalary prostheses: a clinical analytic study with the cooperative utilization of multiple technologies.

BACKGROUND: To reconstruct massive bone defects of the femoral diaphysis and proximal end with limited bilateral cortical bone after joint-preserving musculoskeletal tumor resections, two novel 3D-printed customized intercalary femoral prostheses were applied. METHODS: A series of nine patients with malignancies who received these novel 3D-printed prostheses were retrospectively studied between July 2018 and November 2021. The proximal and diaphyseal femur was divided into three regions of interest (ROIs) according to anatomic landmarks, and anatomic measurements were conducted on 50 computed tomography images showing normal femurs. Based on the individual implant-involved ROIs, osteotomy level, and anatomical and biomechanical features, two alternative 3D-printed prostheses were designed. In each patient, Hounsfield Unit (HU) value thresholding and finite element analysis were conducted to identify the bone trabecula and calcar femorale and to determine the stress distribution, respectively. We described the characteristics of each prosthesis and surgical procedure and recorded the intraoperative data. All patients underwent regular postoperative follow-up, in which the clinical, functional and radiographical outcomes were evaluated. RESULTS: With the ROI division and radiographic measurements, insufficient bilateral cortical bones for anchoring the traditional stem were verified in the normal proximal femur. Therefore, two 3D-printed intercalary endoprostheses, a Type A prosthesis with a proximal curved stem and a Type B prosthesis with a proximal anchorage-slot and corresponding locking screws, were designed. Based on HU value thresholding and finite element analysis, the 3D-printed proximal stems in all prostheses maximally preserved the trabecular bone and calcar femorale and optimized the biomechanical distribution, as did the proximal screws. With the 3D-printed osteotomy guide plates and reaming guide plates, all patients underwent the operation uneventfully with a satisfactory duration (325.00 ± 62.60 min) and bleeding volume (922.22 ± 222.36 ml). In the follow-up, Harris Hip and Musculoskeletal Tumor Society scores were ameliorated after surgery (P < 0.001 and P < 0.001, respectively), reliable bone ingrowth was observed, and no major complications occurred. CONCLUSIONS: Two novel 3D-printed femoral intercalary prostheses, which achieved acceptable overall postoperative outcomes, were used as appropriate alternatives for oncologic patients with massive bone defects and limited residual bone and increased the opportunities for joint-preserving tumor resection. Several scientific methodologies utilized in this study may promote the clinical design proposals of 3D-printed implants.

Supramalleolar osteotomies for ankle arthritis: a systematic review.

INTRODUCTION: We investigated the mid-term outcomes of supramalleolar osteotomies regarding "survivorship" [before ankle arthrodesis (AA) or total ankle replacement (TAR)], complication rate and adjuvant procedures required. MATERIAL AND METHODS: PubMed, Cochrane and Trip Medical Database were searched from January 01, 2000. Studies reporting on SMOs for ankle arthritis, in minimum of 20 patients aged 17 or older, followed for a minimum of two years, were included. Quality assessment was performed with the Modified Coleman Methodology Score (MCMS). A subgroup analysis of varus/valgus ankles was performed. RESULTS: Sixteen studies met the inclusion criteria, with 866 SMOs in 851 patients. Mean age of patients was 53.6 (range 17-79) years, and mean follow-up was 49.1 (range 8-168) months. Of the arthritic ankles (646 ankles), 11.1% were classified as Takakura stage I, 24.0% as stage II, 59.9% as stage III and 5.0% as stage IV. The overall MCMS was 55.2 ± 9.6 (fair). Eleven studies (657 SMOs) reported on "survivorship" of SMO, before arthrodesis (2.7%), or total ankle replacement (TAR) (5.8%) was required. Patients required AA after an average of 44.6 (range 7-156) months, and TAR after 36.71 (range 7-152) months. Hardware removal was required in 1.9% and revision in 4.4% of 777 SMOs. Mean AOFAS score was 51.8 preoperatively, improving to 79.1 postoperatively. Mean VAS was 6.5 preoperatively and improved to 2.1 postoperatively. Complications were reported in 5.7% (44 out of 777 SMOs). Soft tissue procedures were performed in 41.0% (310 out of 756 SMOs), whereas concomitant osseous procedures were performed in 59.0% (446 out of 756 SMOs). SMOs performed for valgus ankles failed in 11.1% of patients, vs 5.6% in varus ankles (p < 0.05), with disparity between the different studies. CONCLUSIONS: SMOs combined with adjuvant, osseous and soft tissue, procedures, were performed mostly for arthritic ankles of stage II and III, according to the Takakura classification and offered functional improvement with low complication rate. Approximately, 10% of SMOs failed and patients required AA or TAR, after an average of just over 4 years (50.5 months) after the index surgery. It is debatable whether varus and valgus ankles treated with SMO reveal different success rates.

The impact of hindfoot deformities for the recurrence of hallux valgus after joint-preserving surgeries for rheumatoid forefoot deformities.

BACKGROUND: Recurrence of hallux valgus (HV) is a common complication after forefoot surgery for rheumatoid forefoot deformities. The aim of this study is to evaluate the impact of hindfoot malalignment on recurrence. METHODS: This was a retrospective observational study designed to analyze the radiographic outcomes of 87 feet in 64 patients with rheumatoid arthritis treated with a joint-preserving surgery for HV deformity. Differences in hindfoot alignment preoperatively between the recurrence and nonrecurrence groups was compared. RESULTS: There were no significant differences in hindfoot alignment preoperatively between groups. To estimate the impact of technical problems, the HV and intermetatarsal angles measured from radiographs 3 months postoperatively were compared between groups. The HV angles in the recurrence group were significantly larger than those in the nonrecurrence group (p=0.02). CONCLUSIONS: There were no significant differences between preoperative hindfoot malalignment and postoperative recurrence of HV in rheumatoid forefoot surgeries.

Computer Navigation in Orthopaedic Tumour Surgery.

In orthopaedic bone tumour surgery, surgeons perform malignant bone tumour resections with tumour-free margin. The bone defects following the resections have to be reconstructed to restore limb function. An inaccurate resection with positive surgical margin increased the risk of local recurrence and compromised patients' survival. Conventionally, orthopaedic tumour surgeons analyse two-dimensional (2D) imaging information and mentally integrate to formulate a three-dimensional (3D) surgical plan. It is difficult to translate the surgical plan to the operating room in complex cases.Computer-assisted tumour surgery (CATS) has been developed in orthopaedic oncology for the last decade. The technique may enable surgeons' 3D surgical planning and image-guided bone resection as planned. The technique may apply to difficult surgery in pelvic or sacral tumours, limited resection in joint-preserving tumour surgery or bone defect reconstruction using CAD prostheses or allograft.Early results suggested that the technique may help in safe tumour resection and improve surgical accuracy by replicating the preoperative planning. The improved surgical accuracy may offer clinical benefits.Surgeons have to be aware of the potential errors of the technique that may result in inaccurate bone resections with possible adverse clinical outcomes. Given that bone sarcoma is rare, the published reports from different tumour centres could only analyse relatively small patient population with the heterogeneous histological diagnosis. Multicentre comparative studies with long-term follow-up are necessary to confirm its clinical efficacy.This chapter provides an overview of computer navigation in orthopaedic tumour surgery over the past decade. It (1) describes the current workflow, (2) reports the clinical indications and results and (3) discusses its limitations and future development.

Use of autologous bone marrow stem cell implantation for osteonecrosis of the knee in sickle cell disease: a preliminary report.

BACKGROUND: The purpose of our study was to evaluate safety, feasibility and clinical results of bone marrow mononuclear cell (BMC) implantation for early-stage osteonecrosis of the knee (OK) secondary to sickle cell disease. METHODS: Thirty-three SCD patients (45 knees) with OK treated with BMC implantation in the osteonecrotic lesion were clinically and functionally evaluated through the American Knee Society Clinical Score (KSS), Knee Functional Score (KFS) and Numeric Rating Scale (NRS) pain score. MRI and radiographic examinations of the knee were assessed during a period of five years after intervention. RESULTS: No complications or serious adverse event were associated with BMC implantation. From preoperative assessment to the latest follow-up, there was a significant (p < 0.001) improvement of clinical KSS (64.3 ± 9.7, range: 45-80 and 2.2 ± 4.1, range: 84-100, respectively), KFS (44.5 ± 8.0, range: 30-55 and 91.6 ± 5.8, range: 80-100, respectively) and reduction of NRS pain score (6.7 ± 1.2, range: 4-9 and 3.4 ± 1.0, range: 2-5, respectively). In total, 87% of patients (29/33) consistently experienced improvements in joint function and activity level as compared to preoperative score. No patient had additional surgery following BMC implantation. Radiographic assessment showed joint preservation and no progression to subchondral collapse at most recent follow-up. CONCLUSIONS: The technique of BMC implantation is a promising, relatively simple and safe procedure for OK in SCD patients. Larger and long-term controlled trials are needed to support its clinical effectiveness. TRIAL REGISTRATION: ClinicalTrials.gov NCT02448121 . Retrospectively registered 19 May 2015.

Mid-term results of concentrated autologous bone marrow aspirate transplantation for corticosteroid-associated osteonecrosis of the femoral head in systemic lupus erythematosus.

PURPOSE: We had previously established concentrated autologous bone marrow aspirate transplantation (CABMAT), a one-step, low-invasive, joint-preserving surgical technique for treating osteonecrosis of the femoral head (ONFH). This study aimed to evaluate the effects of CABMAT as a hip-preserving surgical approach, preventing conversion to total hip arthroplasty (THA) and femoral head collapse in patients with systemic lupus erythematosus (SLE). METHODS: Since 2003, 52 SLE patients (8 male, 44 female, 92 hips, mean age 35.3 (16-77) (years) were treated with CABMAT. The mean follow-up period was 5.5 (0.7-14) years. Conversion rate to THA and its predicting factors were analyzed. RESULTS: The overall conversion rate to THA was 29% (27/92). Conversion rate to THA was 0% (0/3), 0% (0/4), 22% (9/41), and 41% (18/44) in types A, B, C1, and C2, respectively. Conversion rate to THA was 26% (5/19), 26% (6/23), 28% (11/39), 44% (4/9), and 50% (1/2) in stages 1, 2, 3A, 3B, and 4, respectively. In multivariate logistic regression analysis, sex, body mass index (BMI), pre-operative type, and pre-operative stage were significantly correlated with conversion to THA. CONCLUSION: The conversion rate to THA was lower than that in the natural course and core decompression, but was higher than that seen in other bone marrow transplantation and osteotomy. Since sex, pre-operative type, and pre-operative stage were significantly correlated with conversion to THA, it is suggested that the higher proportion of women, advanced stage (stage 3A or above), and advanced type (type C or above) in this study affected the THA conversion rate.

Surgical treatment for diffused-type giant cell tumor (pigmented villonodular synovitis) about the ankle joint.

BACKGROUND: Diffused-type giant cell tumor(Dt-GCT) is a rare, aggressive disorder of the joint synovium, bursa and tendon sheaths. Osseous erosions and subchondral cysts may develop as the result of synovium infiltration in Dt-GCT. We present a retrospective study of a series of patients who are diagnosed with Dt-GCT about the ankle joint, there clinical outcome is evaluated in this study. MATERIAL AND METHOD: Fifteen patients with radiologically and histologically confirmed Dt-GCT about the ankle joint were identified in our foot and ankle department. Patients were managed with open synovectomy for the tumor tissue and bone grafting for bony erosions. X-rays and MRI scans were used for evaluation of the tumor and bony erosions pre- and post-operatively. Pre- and post-operative ankle function was assessed using the American Orthopedic Foot and Ankle Society -Ankle and Hindfoot (AOFAS-AH) score and the Muscularskeletal Tumor Society (MSTS) score. RESULTS: The mean follow-up duration was 37.4 months (range 25 to 50 months). There were 6 males and 9 females, with a mean age of 35 years old (range 18 to 65 years). All patients had talar erosion with the average size of 10.1*9.1*8.2 mm, distal tibia was affected in 5 patients with the average size of 6.2*5.6*5.8 mm. 7 patients had tendon involvement, 2 patients had recurrence and progression of ankle osteoarthritis. Both of them underwent ankle fusion. At the time of last follow-up, the mean AOFAS-AH score increased from 49 to 80 points (p < 0.05), the MSTS score increased from 12 to 22 points (p < 0.05). CONCLUSION: For Dt-GCT with bony erosions, open synovectomy combined with bone grafting seems to be a safe and effective operation for the salvage of ankle joint. Fusion is recommended for failed and severe cartilage destruction of the ankle joint.

Long-term results of rotational acetabular osteotomy for osteonecrosis with collapse of the femoral head in young patients.

PURPOSE: The surgical treatment of osteonecrosis with collapse of the femoral head is still controversial. The purpose of this study was to investigate the clinical outcome of rotational acetabular osteotomy by Ninomiya and Tagawa for osteonecrosis of the femoral head in young patients. PATIENTS AND METHODS: Rotational acetabular osteotomy was performed in 202 consecutive patients between 1995 and 2003. Among them, rotational acetabular osteotomy with osteonecrosis of the femoral head was performed in 31 patients (42 hips). The mean age at the time of surgery was 31.2 years (range 16-45). The mean duration of follow-up was 16.1 years (range 13.1-21 years). RESULTS: The mean preoperative Japanese Orthopedic Association hip score of 56.8 points improved to a mean of 72.4 points at the final follow-up. The 10-year survival rate with conversion to total hip arthroplasty as an end-point was 91.9%, and the 15-year survival rate was 75.5%, the 20-year survival rate was 67.9%. The conversion to total hip arthroplasty was performed in nine hips. The average time to the conversion to total hip arthroplasty was 12.1 years. CONCLUSIONS: Even though the necrotized range is wide, if normal cartilage remains on the lateral side of the femoral head, it can be utilized for the weight-bearing region by laterally rotating the acetabulum. Since the outcome was favorable, we believe that this is a valuable treatment option for this disease.

What factors predict the failure of curved intertrochanteric varus osteotomy for the osteonecrosis of the femoral head?

INTRODUCTION: The purpose of this study was to examine the 10-year survivorship and clinical outcome after curved intertrochanteric varus osteotomy (CVO) for the osteonecrosis of the femoral head (ONFH), and to determine what factors predict the failure of this procedure. MATERIALS AND METHODS: We retrospectively reviewed 102 consecutive CVOs in 93 patients diagnosed with ONFH. Mean follow-up duration was 10.1 years (3.0-23.2 years). Factors associated with radiographic failure (secondary collapse and/or osteoarthritic change), conversion to total hip arthroplasty (THA) and low Harris Hip Score (HHS), were assessed. The Kaplan-Meier method was used to estimate survival rate. RESULTS: Radiographic failure occurred in 27 hips (26.5 %), and 11 hips (10.8 %) were converted to THA. The 10-year survival rate was 91.0 % [95 % confidence interval (CI) 83.4-95.2 %] with conversion to THA as the endpoint and 72.4 % (95 % CI 62.3-80.3 %) with radiographic failure as the endpoint. Mean HHS improved from 70.0 preoperatively to 88.1 at the final follow-up (p < 0.001). Multivariate Cox regression analysis showed that postoperative intact ratio <33.3 % [hazard ratio (HR), 11.17; 95 % CI 4.14-30.14] and center-edge (CE) angle <25° (HR 4.91; 95 % CI 1.92-12.55) were independent factors determining radiographic failure. In addition, the multivariate Cox regression analysis showed that postoperative intact ratio <33.3 % (HR 10.65; 95 % CI 2.24-50.53) and CE angle <25° (HR 7.81; 95 % CI 2.17-28.07) were also factors determining conversion to THA. Worse HHSs of <80 were seen in patients with postoperative intact ratio <33.3 % (p < 0.001), CE angle <25° (p < 0.001), and acetabular head index <75 % (p = 0.006). CONCLUSIONS: Postoperative intact ratio <33.3 % and CE angle <25° were identified as independent factors determining radiographic failure and conversion to THA. Therefore, these factors must be taken into consideration when selecting patients for CVO.

[Intertrochanteric femoral osteotomy : Indications, surgical technique, results]. / Die intertrochantäre Femurosteotomie : Indikationen, Operationstechnik, Ergebnisse.

BACKGROUND: Intertrochanteric osteotomies are part of joint-preserving hip surgery. Indications involve not only the mature but also the growing skeleton. After identification of the causative pathologies multidimensional corrections with the aim of a better joint situation and prevention of early osteoarthritis are possible. METHODS: The surgical technique of intertrochanteric osteotomies is presented. Potential indications are discussed on the basis of results in the literature. RESULTS: In the surgical treatment of developmental dysplasia of the hip intertrochanteric osteotomies are used as additional surgery. In Perthes disease the containment is improved while the onset of osteoarthritis in epiphysis capitis femoris can be decelerated. Treatment of torsion pathologies is reliable. Avascular necrosis of the femoral head and beginning osteoarthritis are critical indications. CONCLUSION: For appropriate indications intertrochanteric osteotomies are a valuable element in joint-preserving surgery with very good long-term results.

Treatment of Varus Ankle Osteoarthritis and Instability With a Novel Mortise-Plasty Osteotomy Procedure.

Although joint-preserving surgery for intermediate ankle osteoarthritis has been reported to be effective, failures of supramalleolar osteotomy and plafond-plasty can occur because of persistent malalignment of the distal tibia and incongruent ankle mortise. We introduce a novel opening wedge distal tibial osteotomy procedure (mortise-plasty) with rigid plate fixation combined with synthetic bone wedges. We performed 27 mortise-plasties in 25 patients with varus ankle osteoarthritis and instability. Six males (24%) and 19 females (76%), with a mean age of 63 (range 28 to 79) years, were followed up for a mean of 27.3 (range 14 to 45) months. The mean preoperative visual analog scale score, American Orthopaedic Foot and Ankle Society score, and Takakura ankle scale score were 7.4 (range 5.4 to 10), 58.7 (range 18 to 84), and 55.9 (range 29 to 88), respectively. These scores improved significantly to 2.1 (range 0 to 6.5), 89.3 (range 67 to 100), and 84.7 (range 55 to 100) postoperatively (p < .001). The mean preoperative tibial-anterior surface angle and talar tilt angle were 84.9° (range 78° to 90°) and 8.3° (range 3° to 21°), respectively. At the most recent follow-up visit, the corresponding values were 95.0° (range 82° to 99°) and 1.8° (range 0° to 8°), respectively (p < .001). Computed tomography scans indicated that the ankle mortise narrowed by approximately 1.8 mm and the tibial plafond was lowered after osteotomy. No patients underwent lateral ligament reconstruction, ankle joint replacement, or arthrodesis. Mortise-plasty osteotomy corrects the intra-articular and extra-articular deformities simultaneously and provides good clinical and radiographic outcomes for patients with varus ankle osteoarthritis and instability.

A comparative study on the results of the modified Ludloff osteotomy for hallux valgus deformities with minimal erosion of the metatarsophalangeal joints in rheumatoid patients versus non-rheumatoid patients.

OBJECTIVES: We aimed to compare the outcomes of joint-preserving surgery for hallux valgus deformities with minimal erosion of the metatarsophalangeal joint in rheumatoid patients with non-rheumatoid controls, and to determine the prognostic factors of recurrence in rheumatoid patients. METHODS: A total of 18 rheumatoid patients (20 feet, Group I) and 35 non-rheumatoid patients (39 feet, Group II) were included. The mean follow-up was 29.6 months. Radiographic and clinical outcomes were compared. To identify the prognostic factors for recurrences in rheumatoid patients, subgroup analyses were done in Group I. RESULTS: Most of the outcomes showed favorable results in both groups. However, Group II had better results in hallux valgus angle (HVA) (15.9° vs. 7.9°, p < 0.001), and in sesamoid position (p = 0.040) at final follow-up. Group I showed higher recurrence rate (50% vs. 0%). The final American Orthopaedic Foot and Ankle Society score was better in Group II (82.1 vs. 90.7, p = 0.014). The large preoperative HVA, non-performance of Akin osteotomy, and insufficient reduction of sesamoid position were related to recurrence in rheumatoid patients. CONCLUSIONS: Joint-preserving surgery for hallux valgus deformities in rheumatoid forefoot deformity showed favorable results in mid-term follow-up; however, it should be warned of possible recurrent deformities.

Long-term outcome of joint-preserving surgery by combination metatarsal osteotomies for shortening for forefoot deformity in patients with rheumatoid arthritis.

OBJECTIVES: We report the long-term outcome of joint-preserving surgery by combining metatarsal osteotomies for shortening for forefoot deformity in patients with rheumatoid arthritis (RA). METHODS: Forty-three patients (57 feet) aged 41.7-70.8 years (mean, 57.7 years) underwent a combination of first tarsometatarsal fusion and distal realignment (modified Lapidus procedure), shortening oblique osteotomies of the bases of metatarsals 2-4, and fifth ray osteotomy (modified Coughlin procedure). Patients were followed up for 64-108 months (mean, 76.6 months). RESULTS: Average postoperative Foot Function Index scores for pain, disability, and activity were 10.3, 19.9, and 16.2, respectively. Average Japanese Society for Surgery of the Foot RA foot and ankle score improved significantly from 52.1 points preoperatively to 90.3 points postoperatively. Postoperatively, 41% of patients reported some forefoot stiffness, but showed no disability. Residual deformity and callosity were absent in all patients. Average hallux valgus and intermetatarsal angles decreased postoperatively from 48.5° to 8.6° and from 15.2° to 4.6°, respectively. Nonunion in two metatarsals, hardware breakage in three, and mild infection in one were identified during follow-up. CONCLUSIONS: With good perioperative medical management of RA, surgical repositioning of the metatarsophalangeal joints by proximal metatarsal shortening and consequent relaxing of the surrounding soft tissue shows successful long-term results.

Size and shape of the lunate surface in different types of pincer impingement: theoretical implications for surgical therapy.

OBJECTIVE: Acetabular rim trimming is indicated in pincer hips with an oversized lunate surface but could result in a critically decreased size of the lunate surface in pincer hips with acetabular malorientation. There is a lack of detailed three-dimensional anatomy of lunate surface in pincer hips. Therefore, we questioned how does (1) size and (2) shape of the lunate surface differ among hips with different types of pincer impingement? METHOD: We retrospectively compared size and shape of the lunate surface between acetabular retroversion (48 hips), deep acetabulum (34 hips), protrusio acetabuli (seven hips), normal acetabuli (30 hips), and hip dysplasia (45 hips). Using magnetic resonance imaging (MRI) arthrography with radial slices we measured size in percentage of the femoral head coverage and shape using the outer (inner) center-edge angles and width of lunate surface. RESULTS: Hips with retroversion had a decreased size and deep hips had normal size of the lunate surface. Both had a normal shape of the outer acetabular rim. Protrusio hips had an increased size and a prominent outer acetabular rim. In all three types of pincer hips the acetabular fossa was increased. CONCLUSION: Size and shape of the lunate surface differs substantially among different types of pincer impingement. In contrast to hips with protrusio acetabuli, retroverted and deep hips do not have an increased size of the lunate surface. Acetabular rim trimming in retroverted and deep hips should be performed with caution. Based on our results, acetabular reorientation would theoretically be the treatment of choice in retroverted hips.

Outcomes of Joint-Preserving Surgery for Forefoot Deformities in Patients With Rheumatoid Arthritis.

BACKGROUND: With the advent of effective disease-modifying medications, the surgical treatment of forefoot deformities in patients with rheumatoid arthritis (RA) has evolved from joint-sacrificing to joint-preserving surgery. However, it is unclear whether joint-preserving surgery is effective for the full range of metatarsophalangeal joint involvement. Hence, this study investigated the postoperative outcomes of joint-preserving surgery for rheumatoid forefoot deformities with a wide range of joint destruction. METHODS: This retrospective observational study included 68 feet from 68 patients with RA who underwent joint-preserving surgery for forefoot deformities between 2014 and 2020. The Larsen grade classification was used to assess the first metatarsophalangeal joint destruction and classify patients into 4 groups as follows: 0 and 1 (n = 14), 2 (n = 21), 3 (n = 19), and 4 and 5 (n = 14). The Self-Administered Foot and Ankle Evaluation Questionnaire (SAFE-Q) score, hallux valgus angle (HVA), and intermetatarsal angle (IMA) were determined before surgery and at the last follow-up visit. RESULTS: The median observation duration was 40 (range, 24-78) months. SAFE-Q scores of all groups significantly improved in all subscales at the last observation, with no significant differences among the study groups. Radiographic evaluations of all groups revealed significant improvements in HVA and IMA after surgery, with no significant differences among the groups. CONCLUSION: In patients using the surgical approaches described in this study, joint-preserving surgery for rheumatoid forefoot deformities led to satisfactory clinical and radiographic improvements, regardless of the severity of joint destruction. LEVEL OF EVIDENCE: Level III, case-control study.

Fluoroscopically calibrated 3D-printed patient-specific instruments improve the accuracy of osteotomy during bone tumor resection adjacent to joints.

BACKGROUND: Inadequate surface matching, variation in the guide design, and soft tissue on the skeletal surface may make it difficult to accurately place the 3D-printed patient-specific instrument (PSI) exactly to the designated site, leading to decreased accuracy, or even errors. Consequently, we developed a novel 3D-printed PSI with fluoroscopy-guided positioning markers to enhance the accuracy of osteotomies in joint-preserving surgery. The current study was to compare whether the fluoroscopically calibrated PSI (FCPSI) can achieve better accuracy compared with freehand resection and conventional PSI (CPSI) resection. METHODS: Simulated joint-preserving surgery was conducted using nine synthetic left knee bone models. Osteotomies adjacent to the knee joint were designed to evaluate the accuracy at the epiphysis side. The experiment was divided into three groups: free-hand, conventional PSI (CPSI), and fluoroscopically Calibrated PSI (FCPSI). Post-resection CT scans were quantitatively analyzed. Analysis of variance (ANOVA) was used. RESULT: FCPSI improved the resection accuracy significantly. The mean location accuracy is 2.66 mm for FCPSI compared to 6.36 mm (P < 0.001) for freehand resection and 4.58 mm (P = 0.012) for CPSI. The mean average distance is 1.27 mm compared to 2.99 mm (p < 0.001) and 2.11 mm (p = 0.049). The mean absolute angle is 2.16° compared to 8.50° (p < 0.001) and 5.54° (p = 0.021). The mean depth angle is 1.41° compared to 8.10° (p < 0.001) and 5.32° (p = 0.012). However, there were no significant differences in the front angle compared to the freehand resection group (P = 0.055) and CPSI (P = 0.599) group. The location accuracy observed with FCPSI was maintained at 4 mm, while CPSI and freehand resection exhibited a maximum deviation of 8 mm. CONCLUSION: The fluoroscopically calibrated 3D-printed patient-specific instruments improve the accuracy of osteotomy during bone tumor resection adjacent to joint joints compared to conventional PSI and freehand resection. In conclusion, this novel 3D-printed PSI offers significant accuracy improvement in joint preserving surgery with a minimal increase in time and design costs.

Pre-operative Planning of High Tibial Osteotomy With ChatGPT: Are We There Yet?

INTRODUCTION: ChatGPT (Chat Generative Pre-trained Transformer), developed by OpenAI (San Francisco, CA, USA), has gained attention in the medical field. It has the potential to enhance and simplify tasks, such as preoperative planning in orthopedic surgery. We aimed to test ChatGPT's accuracy in measuring the angle of correction for high tibial osteotomy for cases planned and performed at a tertiary teaching hospital in Singapore. MATERIALS AND METHODS: Peri-operative angular parameters from 114 consecutive patients who underwent medial opening wedge high tibial osteotomy (MOWHTO) were used to query ChatGPT 3.0. First ChatGPT 3.0 was queried on what information it required to plan a MOWHTO. Based on its response, pre-operative medial proximal tibial angle (MPTA) and joint line congruence angle (JLCA) were provided. ChatGPT 3.0 then responded with its recommended angle of correction. This was compared against the manually planned surgical correction by our fellowship-trained surgeon. A root mean square analysis was then performed to compare ChatGPT 3.0 and manual planning. RESULTS: The root mean square error (RMSE) of ChatGPT 3.0 in predicting correction angle in MWHTO was 2.96, suggesting a very poor model fit. CONCLUSION: Although ChatGPT 3.0 represents a significant breakthrough in large language models with extensive capabilities, it is not currently optimized to effectively perform complex pre-operative planning in orthopedic surgery, specifically in the context of MOWHTO. Further refinement and consideration of specific factors are necessary to enhance its accuracy and suitability for such applications.

Indications, Associated Procedures, and Results of Ankle Plafond-Plasty for Varus Ankle Osteoarthritis: A Systematic Review and Meta-Analysis.

BACKGROUNDS: Plafond-plasty is a joint-preserving procedure to treat varus ankle osteoarthritis (OA) with asymmetrical joint involvement. The aim of this systematic review and meta-analysis was to evaluate indications, different surgical techniques, associated procedures, and results of plafond-plasty in varus ankle OA and to analyze the level of evidence (LOE) and quality of evidence (QOE) of the included studies. METHODS: A systematic review of the literature was performed using MEDLINE, Embase, and Cochrane. RESULTS: Five studies evaluating 99 ankles were included. A non-rigid varus ankle deformity and an ankle OA Takakura stage 3b or less were the most recommended pre-operative indications. Meta-analysis showed a significant post-operative improvement in clinical and radiological parameters. Many associated surgical procedures have been reported, the most frequent being medial additional supramalleolar osteotomy and lateral ankle ligament reconstruction. The level of evidence and methodological quality assessment of the included studies showed an overall low quality. CONCLUSION: Plafond-plasty seems to be a promising surgical option when managing varus ankle OA with asymmetrical joint involvement, extending the indications for joint sparing surgery. Additional associated procedures should be carefully evaluated case-by-case. LEVELS OF EVIDENCE: IV.

Preoperative degree of deformity and underlying disease affect the postoperative deformity of joint-preserving hallux valgus surgery.

BACKGROUND: The combination of distal osteotomy with lateral dissection in joint-preserving surgery for severe hallux valgus deformity has recently begun to yield encouraging results. We examined the frequency of complications and risk factors of those for joint-preserving surgery in patients with and without rheumatoid arthritis (RA). METHODS: A retrospective, observational study of 72 feet (27 patients with RA) was performed. The inclusion criteria were patients who underwent joint-preserving surgery for hallux valgus deformity at our hospital between January 2008 and March 2016 who could be followed up with for longer than 12 months. RESULTS: The mean preoperative and immediate postoperative hallux valgus angles (HVA) were 41.8 and 4.4, respectively. The mean preoperative and immediate postoperative intermetatarsal angles between the first and second metatarsal bones (M1-M2A) were 14.6 and 5.8, respectively. At the final postoperative evaluation, the mean HVA was 8.8 and the mean M1-M2A was 6.4.Data were compared among the patients with complications (recurrent valgus deformity, varus deformity), and those without complications (normal HVA) at the final postoperative evaluation. The rate of RA in the varus deformity group was 71.4%, which tended to be higher than in other groups (p = .058). The mean preoperative HVA were 48.2 and 52.6 in the group of recurrent valgus deformity and varus deformity, which was higher than the normal HVA group (p = .001). CONCLUSIONS: High preoperative HVA was a risk factor for the recurrence of valgus deformity. Most of the varus deformities were observed in the RA group with high preoperative HVA; therefore, caution should be exercised in operating on patients with severe deformity or those with RA. LEVEL OF EVIDENCE: III.

A systematic approach to managing complications after proximal tibial osteotomies of the knee.

Proximal tibial osteotomy (PTO) is an effective procedure for active and young adult patients with symptomatic unicompartmental osteoarthritis and malalignment. They were considered technically demanding and prone to various complications related to the surgical technique, biomechanical or biological origin. Among the most important are hinge fractures and delayed or non-healing, neurovascular complications, loss of correction, implant-related problems, patellofemoral complaints, biological complications and changes in limb length. Being aware of these problems can help minimizing their prevalence and improve the results of the procedure.The aim of this narrative review is to discuss the potential complications that may occur during and after proximal tibial osteotomies, their origin and ways to prevent them.