Failure of dual plating in a complex open distal femur fracture as the result of major trauma

A 61-year-old polytrauma patient was admitted with a right distal comminuted metaphyseal femoral fracture with intra-articular extension (Orthopaedic Trauma Association 33C2.3 classification) among other injuries. Due to the high degree of comminution and massive bone loss, this was initially managed with a dual plating open reduction internal fixation. Dual plating has shown to be a superior fixation method than single variable angle locking compression plate (VA-LCP) plating providing greater fixation in metaphyseal bone. Our case reports the failure of dual plating which required removal of metalwork and subsequent fixation using intramedullary nail and plate technique. Failure of dual plating is not well documented in the literature. The most recent radiographs taken 15 months postrevision surgery show that the bone has started to heal with evidence of callus formation.

Initial Assessments of a Handheld Indentation Probe's Correlation with Cancellous Bone Density, Stiffness and Strength: An Objective Alternative to 'Thumb Testing'

During shoulder arthroplasty, surgeons must select the optimal implant for each patient. The metaphyseal bone properties affect this decision; however, the typical resection 'thumb test' lacks objectivity. The purposes of this investigation were: to determine the correlation strength between the indentation depth of a handheld mechanism and the density, compressive strength and modulus of a bone surrogate; as well as to assess how changing the indenter tip shape and impact energy may affect the correlation strengths. A spring-loaded indenter was developed. Four tip shapes (needle, tapered, flat and radiused cylinders) and four spring energies (0.13J-0.76J) were assessed by indenting five cellular foam bone surrogates of varying density. The indentation depth was measured and correlated with apparent density, compressive strength and modulus. Indentation depth plateaued as the bone surrogate's material properties increased, particularly for indentation tips with larger footprints and the 0.13J spring. All tip shapes produced strong (R2≥0.7) power-law relationships between the indentation depth metric and the bone surrogate's material properties (density: 0.70 ≤ R2 ≤ 0.95, strength: 0.75 ≤ R2 ≤ 0.97, modulus: 0.70 ≤ R2 ≤ 0.93); though use of the needle tip yielded the widest indentation depth scale. These strong correlations suggest that a handheld indenter may provide objective intraoperative evidence of cancellous material properties. Further investigations are warranted to study indenter tip shape and spring energy in human tissue; though the needle tip with spring energy between 0.30J and 0.76J seems the most promising.

Intra-articular low-dose parathyroid hormone (1-34) improves mobility and articular cartilage quality in a preclinical age-related knee osteoarthritis model

Aims Osteoarthritis (OA) is prevalent among the elderly and incurable. Intra-articular parathyroid hormone (PTH) ameliorated OA in papain-induced and anterior cruciate ligament transection-induced OA models; therefore, we hypothesized that PTH improved OA in a preclinical age-related OA model. Methods Guinea pigs aged between six and seven months of age were randomized into control or treatment groups. Three- or four-month-old guinea pigs served as the young control group. The knees were administered 40 μl intra-articular injections of 10 nM PTH or vehicle once a week for three months. Their endurance as determined from time on the treadmill was evaluated before kill. Their tibial plateaus were analyzed using microcalculated tomography (μCT) and histological studies. Results PTH increased the endurance on the treadmill test, preserved glycosaminoglycans, and reduced Osteoarthritis Research Society International score and chondrocyte apoptosis rate. No difference was observed in the subchondral plate bone density or metaphyseal trabecular bone volume and bone morphogenetic 2 protein staining. Conclusion Subchondral bone is crucial in the initiation and progression of OA. Although previous studies have shown that subcutaneous PTH alleviates knee OA by improving subchondral and metaphyseal bone mass, we demonstrated that intra-articular PTH injections improved spontaneous OA by directly affecting the cartilage rather than the subchondral or metaphyseal bone in a preclinical age-related OA model. Cite this article: Bone Joint Res 2021;10(8):514–525.

Simulating Metaphyseal Fracture Healing in the Distal Radius

Simulating diaphyseal fracture healing via numerical models has been investigated for a long time. It is apparent from in vivo studies that metaphyseal fracture healing should follow similar biomechanical rules although the speed and healing pattern might differ. To investigate this hypothesis, a pre-existing, well-established diaphyseal fracture healing model was extended to study metaphyseal bone healing. Clinical data of distal radius fractures were compared to corresponding geometrically patient-specific fracture healing simulations. The numerical model, was able to predict a realistic fracture healing process in a wide variety of radius geometries. Endochondral and mainly intramembranous ossification was predicted in the fractured area without callus formation. The model, therefore, appears appropriate to study metaphyseal bone healing under differing mechanical conditions and metaphyseal fractures in different bones and fracture types. Nevertheless, the outlined model was conducted in a simplified rotational symmetric case. Further studies may extend the model to a three-dimensional representation to investigate complex fracture shapes. This will help to optimize clinical treatments of radial fractures, medical implant design and foster biomechanical research in metaphyseal fracture healing.

Mid-term subsidence and periprosthetic radiolucency of the AMIStem: a 5-year EBRA-FCA analysis

Background There has been an evolution in cementless total hip arthroplasty (THA) with newer short stem designs aimed to preserve metaphyseal bone stock and facilitate implantation through minimally invasive approaches. While early subsidence has been correlated to aseptic loosening in conventional stems, there is a paucity of data regarding short stems. The current study aims to report on stem subsidence and mid-term clinical outcomes of a cementless, metaphyseal-anchored short femoral stem, specifically designed for the direct anterior approach (DAA). Methods Ninety-four consecutive patients (100 hips) with a minimum follow-up of 5 years following cementless THA were included in this single-center retrospective study. Subsidence was evaluated using the “Ein-Bild-Roentgen-Analyse” (EBRA). Periprosthetic radiolucency allocated to the zones of Charnley and Gruen was assessed. Additionally, demographic and implant-related factors potentially associated with increased subsidence and clinical outcomes were evaluated. Results At the last follow-up, the average stem subsidence was 1.98 ± 1.20 mm, with 48% of the implants demonstrating subsidence of > 2 mm. Periprosthetic radiolucency of > 2 mm was found in 26% of the implants in zone 1 and in 9% in zone 7, respectively. Neither the amount of subsidence nor proximal periprosthetic radiolucency was associated with aseptic loosening or worse clinical outcomes. Conclusions Comparable to other proximally fixed short stem designs, the highest subsidence was observed within the first 3 months following implantation. No demographic or implant-related factors were found to have a statistically significant influence on stem subsidence. Periprosthetic radiolucency and subsidence of the AMISstem is not correlated with worse clinical outcomes at 5-year follow-up.

Surgical and Protocolized Management of Distal Radius Nonunion

Introduction Nonunion of the distal radius is an extremely rare and serious complication with unpredictable outcomes. The aim of the present study is to analyze the radiological and functional results after a protocolized surgical treatment. Material and Methods A retrospective review of case series of patients with diagnosis of nonunion of the distal radius surgically treated from 2010 to 2016. The diagnosis of nonunion was made at 6 months without signs of consolidation. According to computed tomography (CT) scan images, we propose a classification of this complication as type I: no deformity or mild deformity, with subchondral metaphyseal bone stock beneath lunate facet greater than 10 mm, with no degenerative changes at the distal radioulnar joint (DRUJ); type II: moderate deformity or degenerative changes in the DRUJ, distinguishing between IIA and IIB based on the subchondral metaphyseal bone stock; and type III: degenerative changes at the midcarpal joint. In all cases, a reconstructive technique consisting of volar locking plate osteosynthesis with autologous tailored iliac crest graft was performed, hence none of the cases were classified as type III. Results In total, six cases were included. Mean follow-up: 58 months (range: 30–108 months). Consolidation was achieved in a mean period of 5 months (range: 3–9 months). Average active range of motion: flexion: 54° (range: 10°–80°); extension: 40° (range: 10°–85°); supination: 82.5° (range: 75°–85°); pronation 80° (range: 55–85°); radial deviation: 15° (range: 5°–20°); and ulnar deviation 15° (range: 5–20°). Mean strength: 24.15 Kg (6.9–35 Kg). The average score on the Visual Analog Scale (VAS) at rest was of 0.6 (0–2), and with movement, it was of 1.8 (0–4). The mean postoperative score on the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was of 18.48 (range: 0–50.8). Average radial height: 9.65 mm (range: 7–12 mm); average radial angulation: 17° (10°–20°); volar tilt: 8.36° (range: 0.2°–21°); average ulnar variance: 1.52 mm (range: 0–3.5 mm). Complications: persistent nonunion, superficial wound infection, acquired residual ulnar club hand deformity, radiocarpal arthritis, and midcarpal arthritis. Nevertheless, no salvage techniques were needed or requested during the follow-up, with all patients in an active work situation or living an active life in complete normality. Conclusions The protocolized surgical treatment of pseudoarthrosis of the the distal radius, based on our proposed classification, offers good functional outcomes in the long-term follow-up.