Developing a Computer Vision Model to Automate Quantitative Measurement of Hip-Knee-Ankle Angle in Total Hip and Knee Arthroplasty Patients.

BACKGROUND: Increasing deformity of the lower extremities, as measured by the hip-knee-ankle angle (HKAA), is associated with poor patient outcomes after total hip and knee arthroplasty (THA, TKA). Automated calculation of HKAA is imperative to reduce the burden on orthopaedic surgeons. We proposed a detection-based deep learning (DL) model to calculate HKAA in THA and TKA patients and assessed the agreement between DL-derived HKAAs and manual measurement. METHODS: We retrospectively identified 1,379 long-leg radiographs (LLRs) from patients scheduled for THA or TKA within an academic medical center. There were 1,221 LLRs used to develop the model (randomly split into 70% training, 20% validation, and 10% held-out test sets); 158 LLRs were considered "difficult," as the femoral head was difficult to distinguish from surrounding tissue. There were 2 raters who annotated the HKAA of both lower extremities, and inter-rater reliability was calculated to compare the DL-derived HKAAs with manual measurement within the test set. RESULTS: The DL model achieved a mean average precision of 0.985 on the test set. The average HKAA of the operative leg was 173.05 ± 4.54°; the nonoperative leg was 175.55 ± 3.56°. The inter-rater reliability between manual and DL-derived HKAA measurements on the operative leg and nonoperative leg indicated excellent reliability (intraclass correlation (2,k) = 0.987 [0.96, 0.99], intraclass correlation (2, k) = 0.987 [0.98, 0.99, respectively]). The standard error of measurement for the DL-derived HKAA for the operative and nonoperative legs was 0.515° and 0.403°, respectively. CONCLUSIONS: A detection-based DL algorithm can calculate the HKAA in LLRs and is comparable to that calculated by manual measurement. The algorithm can detect the bilateral femoral head, knee, and ankle joints with high precision, even in patients where the femoral head is difficult to visualize.

Arthrodesis of the first metatarsophalangeal joint for severe hallux valgus in adolescents with cerebral palsy: A retrospective comparison study of three surgical techniques.

Purpose: We compared the outcomes of arthrodesis of the first metatarsophalangeal joint for severe hallux valgus in 31 adolescents with cerebral palsy, using three different methods of fixation: K-wires, non-locking plates, and locking plates. Methods: Clinical outcomes included time to weight-bearing, fusion rates and surgical complications. Radiographic assessment included comparing pre- and post-operative hallux valgus angles, intermetatarsal angles, interphalangeal angles, and lateral metatarsophalangeal angles. Patient-reported outcomes included pre- and post-operative visual analogue scales addressing bunion pain and concerns, difficulties with wearing shoes and braces, and difficulties with foot hygiene. Results: Of the 31 adolescents (16 male), 10 patients had K-wire fixation, 11 had a non-locking dorsal plate, and 10 had fixation with a dorsal locking plate. Mean age at surgery was 16 years (12-18 years) and mean follow-up was 4 years (2.7-6.5 years). Patients with K-wire fixation had delayed weight-bearing and had more complications than those managed by dorsal plating. There were significant improvements in radiographic parameters (except interphalangeal angle) and in patient-reported outcomes, in all groups (p < 0.001). However, radiographic and clinical outcomes were better in the dorsal plating groups compared to the K-wire group. Conclusion: Arthrodesis of the first metatarsophalangeal joint gave good correction of deformity with improvements in symptoms and radiographic parameters in adolescents with cerebral palsy. We recommend dorsal plating that allowed early weight-bearing and had fewer complications with better clinical and radiographic outcomes, than K-wire fixation. Level of evidence: IV: Retrospective case series.

Osteochondral repair using an acellular dermal matrix-pilot in vivo study in a rabbit osteochondral defect model.

The aim of this pilot project was to introduce a novel use of acellular dermal matrix (ADM) in combination with infrapatellar fat pad mesenchymal stromal cells (IPFP-MSCs) to effect repair in a rabbit osteochondral defect model. ADM, in a range of surgical procedures, has been shown to promote remodelling of tissue at the site of implantation. Rabbit-derived ADM (rabADM) was prepared from the skin of donor rabbits. Autologous IPFP-MSCs were obtained at the time of knee surgery. Osteochondral defects (4 mm cartilage outer/2 mm central bone defect) were drilled into distal femoral condyles of 12 New Zealand White rabbits. Treatments groups: (i) defect only; (ii) rabADM alone; (iii) IPFP-MSCs alone; and (iv) rabADM with IPFP-MSCs. Condyles were harvested at 12 weeks, and analyzed using histology, immunohistochemistry (types I and II collagen) and histomorphometry to evaluate osteochondral repair. The rabADM only group achieved the highest ratio of type II to non-type II collagen (77.3%) using areal measures (similar to normal cartilage), which indicated a higher quality of cartilage repair. The addition of IPFP-MSCs, with or without rabADM, formed a fibrous collagen cap above the lesion site not seen with rabADM alone. Macroscopically, there was no joint erosion, inflammation, swelling or deformity, and all animals maintained full range of motion. CONCLUSIONS: RabADM alone resulted in neocartilage formation similar to native cartilage. IPFP-MSCs limited osteochondral repair and contributed to fibrosis, even in combination with the rabADM. Further studies using ADM for osteochondral repair are warranted in a more appropriate pre-clinical model of osteochondral repair. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1919-1928, 2018.

Chondrogenesis of Human Infrapatellar Fat Pad Stem Cells on Acellular Dermal Matrix.

Acellular dermal matrix (ADM) has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation, revascularisation and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFß3 and BMP6. Human infrapatellar fat pad-derived adipose stem cells (IPFP-ASC) were cultured with ADM derived from rat dermis in chondrogenic (TGFß3 and BMP6) medium in vitro for 2 and 4 weeks. Histology, qPCR, and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans). At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially, which stained positively for collagen Type II and proteoglycans. Significant cell-matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increased COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks. We believe that the principles that make ADM versatile and successful for tissue regeneration are applicable to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate, and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair.

Arthroscopic labral repair of the hip, using a through-labral double-stranded single-pass suture technique.

The normal labrum is crucial to the biomechanical function of the hip joint, not only increasing the surface area and depth of the acetabulum but also maintaining a suction seal to assist in normal synovial fluid flow from the peripheral to the central compartment. Simple loop suture repairs of the labrum may evert the labrum, thus losing the optimal seal, as well as causing abrasion of the articular cartilage. Vertical mattress suture and labral base fixation techniques aim to leave the free edge of the labrum intact and undisturbed, therefore improving the contact of the labrum to the femoral head and neck to improve the seal of the acetabulum. We aim to describe a double-stranded single-pass vertical mattress suture technique that may allow greater versatility to the surgeon in repairing thinner labrums while still achieving a free and continuous free edge.

Chondrogenesis of infrapatellar fat pad derived adipose stem cells in 3D printed chitosan scaffold.

Infrapatellar fat pad adipose stem cells (IPFP-ASCs) have been shown to harbor chondrogenic potential. When combined with 3D polymeric structures, the stem cells provide a source of stem cells to engineer 3D tissues for cartilage repair. In this study, we have shown human IPFP-ASCs seeded onto 3D printed chitosan scaffolds can undergo chondrogenesis using TGFß3 and BMP6. By week 4, a pearlescent, cartilage-like matrix had formed that penetrated the top layers of the chitosan scaffold forming a 'cap' on the scaffold. Chondrocytic morphology showed typical cells encased in extracellular matrix which stained positively with toluidine blue. Immunohistochemistry demonstrated positive staining for collagen type II and cartilage proteoglycans, as well as collagen type I. Real time PCR analysis showed up-regulation of collagen type II, aggrecan and SOX9 genes when IPFP-ASCs were stimulated by TGFß3 and BMP6. Thus, IPFP-ASCs can successfully undergo chondrogenesis using TGFß3 and BMP6 and the cartilage-like tissue that forms on the surface of 3D-printed chitosan scaffold may prove useful as an osteochondral graft.

Differentiation of stem cells from human infrapatellar fat pad: characterization of cells undergoing chondrogenesis.

Hyaline cartilage repair is a significant challenge in orthopedics and current techniques result in formation of fibrocartilage. Human infrapatellar fat pad (hIPFP)-derived mesenchymal stem cells (MSCs) are capable of differentiation into multiple tissue lineages, including cartilage and bone. Chondrogenesis is a crucial part of normal skeletal development but the molecular mechanisms are yet to be completely defined. In this study we sourced hIPFP-derived MSCs utilizing chondrogenic growth factors, transforming growth factor beta-3, and bone morphogenetic protein-6, to form hyaline-like cartilage in micromass cultures and we studied chondrogenic development of 7, 14, and 28 days. The purpose of this study was (1) to characterize chondrogenesis from MSCs derived from hIPFP tissue by conventional techniques and (2) to characterize temporal changes of key molecular components during chondrogenesis using microarray gene expression. Endpoints included histology, immunohistochemistry (IHC), gene expression profiles using a microarray technique, and changes in expression of specific genes using quantitative real-time polymerase chain reaction. Over 14-28 days, clusters of encapsulated chondrocytes formed surrounded by collagen type II and aggrecan in the extracellular matrix (ECM). Collagen type II and aggrecan production was confirmed using IHC and chondrogenic lineage markers were studied; SRY-related transcription factor (SOX9), collagen type II alpha 1 (COL2A1), and aggrecan gene expression increased significantly over the time course. Normalized microarray highlighted 608 differentially expressed genes; 10 chondrogenic genes were upregulated (2- to 87-fold), including COL2A1, COL10A1, COL9A1, COL11A1, COL9A2, COL11A2, COL1A1, COMP, SOX9, and COL3A1. We found that the upregulated genes (twofold or greater) represent significant level of expression (enrichment score) for the ECM structural constituent of the molecular functional at days 7, 14, and 28 during chondrogenesis. Therefore, we have successfully demonstrated in vitro production of hyaline-like cartilage from IPFP-derived MSCs in micromass culture. Microarray has provided information concerning genes involved in chondrogenesis of hIPFP-derived MSCs and our approach offers a viable strategy for generating clinically relevant cartilage for therapeutic use.

Lateral parapatellar approach with tibial tubercle osteotomy for the treatment of non-correctable valgus knee osteoarthritis: a retrospective clinical study.

BACKGROUND: The aim of this retrospective study was to evaluate the efficacy of a lateral parapatellar approach combined with a tibial tubercle osteotomy (TTO) in patients undergoing total knee arthroplasty (TKA) with non-correctable valgus knee osteoarthritis. METHODS: We studied 53 consecutive patients (57 knees) who had a primary TKA via lateral parapatellar approach with a global step-cut "coffin" type TTO over a 10-year period. All patients had non-correctable grade II valgus deformity according to the Ranawat classification. The average age of patients was 71 years (45 to 77) and the mean follow-up was 39 months (20 to 98). RESULTS: Post-surgery, there was a significant improvement in knee extension (p=0.002), flexion (p=0.006), Knee Society Pain and Function Scores (p<0.001) and WOMAC Osteoarthritis Index (p<0.001). The tibiofemoral angle changed from a preoperative median value of 11 deg (10 to 17) to a postoperative value of 3.75 deg (0 to 9). Congruent patellar tracking was observed in all cases. All but one osteotomy united in a median period of 16.7 weeks (9 to 28) and no hardware removal was required. One knee developed infection treated with two-stage reconstruction. A proximal tibial stress fracture also occurred in a patient on long-term bisphosphonate therapy. CONCLUSION: Lateral parapatellar approach along with TTO is an effective technique for addressing non-correctable valgus knee deformity during TKA.

The osteochondral dilemma: review of current management and future trends.

The management of articular cartilage defects remains challenging and controversial. Hyaline cartilage has limited capacity for self-repair and post-injury cartilage is predominantly replaced by fibrocartilage through healing from the subchondral bone. Fibrocartilage lacks the key properties that characterize hyaline cartilage such as capacity for compression, hydrodynamic permeability and smoothness of the articular surface. Many reports relate compromised function associated with repaired cartilage and loss of function of the articular surface. Novel methods have been proposed with the key aim to regenerate hyaline cartilage for repair of osteochondral defects. Over the past decade, with many exciting developments in tissue engineering and regenerative cell-based technologies, we are now able to consider new combinatorial approaches to overcome the problems associated with osteochondral injuries and damage. In this review, the currently accepted surgical approaches are reviewed and considered; debridement, marrow stimulation, whole tissue transplantation and cellular repair. More recent products, which employ tissue engineering approaches to enhance the traditional methods of repair, are discussed. Future trends must not only focus on recreating the composition of articular cartilage, but more importantly recapitulate the nano-structure of articular cartilage to improve the functional strength and integration of repair tissue.

Bioengineering of articular cartilage: past, present and future.

The treatment of cartilage defects poses a clinical challenge owing to the lack of intrinsic regenerative capacity of cartilage. The use of tissue engineering techniques to bioengineer articular cartilage is promising and may hold the key to the successful regeneration of cartilage tissue. Natural and synthetic biomaterials have been used to recreate the microarchitecture of articular cartilage through multilayered biomimetic scaffolds. Acellular scaffolds preserve the microarchitecture of articular cartilage through a process of decellularization of biological tissue. Although promising, this technique often results in poor biomechanical strength of the graft. However, biomechanical strength could be improved if biomaterials could be incorporated back into the decellularized tissue to overcome this limitation.

Handover in the emergency department: deficiencies and adverse effects.

OBJECTIVE: To determine problems resulting from ED handover, deficiencies in current procedures and whether patient care or ED processes are adversely affected. METHODS: A prospective observational study at three large metropolitan ED comprising three components: observation of handover sessions, 2 h post-handover surveys of the receiving doctors and a general survey of ED doctors. RESULTS: The handovers of 914 patients were observed during 60 handover sessions in a 3-month period. Medical information, including presenting complaints, was handed over better than communication and disposition information. Seven hundred and seven (77.4%) of 914 potential post-handover interviews were undertaken. Most (88.3%) doctors thought the handover was 'adequate/good'. However, information was perceived as lacking in 109 (15.4%) handovers, especially details of management (35, 5.0%), investigations (33, 4.7%) and disposition (33, 4.7%). There was a significant difference in the perceived quality of handovers (1-5 scale where 5 = excellent) when all required information was handed over and when it was not (median scores 4.0 vs 3.0, respectively, P < 0.001). As a result of perceived inadequate handovers, the doctor/ED and patient were affected adversely in 62 (8.8%) and 33 (4.7%) cases, respectively, for example, repetition of assessment, delays in disposition and care. Fifty doctors completed the general survey. Most believed communications made to inpatient units, inaccurate/incomplete information and disorganization were problematic. CONCLUSION: Deficiencies in handover processes exist, especially in communication and disposition information. These affect doctors, the ED and patients adversely. Recommendations for improvement include guideline development to standardize handover processes, the greater use of information technology facilities, ongoing feedback to staff, and quality assurance and education activities.