Introduction. When designing a new osteosynthesis device, the biomechanical competence must be evaluated with respect to the acting loads. In a previous study, the loads on the proximal phalanx during rehabilitation exercises were calculated. This study aimed to assess the safety of a novel customizable osteosynthesis device compared to those loads to determine when failure would occur. Method. Forty proximal phalanges were dissected from skeletally mature female sheep and divided into four testing groups. A custom 3D printed cutting and drilling guide was used to create a reduced osteotomy and pilot holes to insert four 1.5 mm cortical screws. A novel light-curable polymer composite was used to fixate the bones with an in situ fixation patch. The constructs were tested in cyclic four-point bending in a bioreactor with ringer solution at 37°C with a valley load of 2 N. Four groups (N = 10) had increasing peak loads based on varying safety factors relative to the physiological loading (G1:100x, G2:150x, G3:175x, G4:250x). Each specimen was tested for 12,600 cycles (6 weeks of rehabilitation) or until failure occurred. After the test the thickness of the patch was measured with digital calipers and data analysis was performed in Python and R. Result. All samples survived in G1, and all failed in G4. G2 and G3 had 1 and 8 failures, respectively. There was no significant difference in patch thickness in all survivor samples against failures (p = 0.131), however, there was a significant difference in the displacement amplitude in the final cycle (0.072 mm vs. 0.15 mm; p < 0.001). Conclusion. This study found the survival and failure limits of a novel osteosynthesis device as a function of physiological loading. These results indicate that such fixations could withstand 100x the loading for typical non-weightbearing rehabilitation. Further studies are needed to confirm the safety for other conditions

The August 2024 Foot & Ankle Roundup³⁶⁰ looks at: ESWT versus surgery for fifth metatarsal stress fractures; Minimally invasive surgery versus open fusion for hallux rigidus; Diabetes and infection risk in total ankle arthroplasty; Is proximal medial gastrocnemius recession useful for managing chronic plantar fasciitis?; Fuse the great toe in the young!; Conservative surgery for diabetic foot osteomyelitis; Mental health and outcome following foot and ankle surgery.

Introduction. The current treatment for Freiberg's osteochondrosis centres around either: simple debridement or debridement osteotomy. The main principle of the osteotomy is to rotate normal articular cartilage into the affected area. We recommend the use of CT scanning to delineate the amount of available, unaffected cartilage available to rotate into the affected space. Methods. We retrospectively reviewed 32 CT scans of new Freiberg's diagnoses in Sheffield over a 10 year period using the PACS system. We identified the sagittal CT slice that displayed the widest portion of proximal articular margin of the proximal phalanx and measured the diseased segment of the corresponding metatarsal head as an arc (in degrees). This arc segment was divided by 360°. This gave a ratio of the affected arc in the sagittal plane. Results. 28 out of 32 cases involved the 2nd metatarsal with the remaining 4 involving the 3rd metatarsal head. Of 32 cases, 18 had fragmentation. Surgically, 20 had debridement only, 5 also had an osteotomy and 1 had a fusion. 6 of the 32 cases were managed non-operatively. 11 cases out of 32 had an arc ratio of < 0.3. Of these, only 3 had an osteotomy, 3 had no procedure and 5 had a simple debridement. Of those that had osteotomies (5/32), 3 of the 5 cases had an arc ratio of < 0.3 with the other 2 being 0.42 and 0.38. Discussion. We hypothesise that those cases with an arc ratio of less 0.3 would be amenable to a dorsal closing wedge osteotomy and those with a ratio of more than 0.4 would be better suited to a simple debridement. For those cases between 0.3–0.4, we feel either option is viable. Further work to prove or disprove outcomes related to our classification is required

The December 2023 Foot & Ankle Roundup³⁶⁰ looks at: Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis; 3D-printed modular endoprosthesis reconstruction following total calcanectomy; Percutaneous partial bone excision in the management of diabetic toe osteomyelitis; Hemiepiphysiodesis is a viable surgical option for Juvenile hallux valgus; Ankle arthroplasty vs arthrodesis: which comes out on top?; Patient-related risk factors for poorer outcome following total ankle arthroplasty; The Outcomes in Ankle Replacement Study.

Aims

This study aimed to evaluate the effectiveness of the induced membrane technique for treating infected bone defects, and to explore the factors that might affect patient outcomes.

The August 2023 Wrist & Hand Roundup360 looks at: Complications and patient-reported outcomes after trapeziectomy with a Weilby sling: a cohort study; Swelling, stiffness, and dysfunction following proximal interphalangeal joint sprains; Utility of preoperative MRI for assessing proximal fragment vascularity in scaphoid nonunion; Complications and outcomes of operative treatment for acute perilunate injuries: a systematic review; The position of the median nerve in relation to the palmaris longus tendon at the wrist: a study of 784 MR images; Basal fractures of the ulnar styloid? A randomized controlled trial; Proximal row carpectomy versus four-corner arthrodesis in SLAC and SNAC wrist; Managing cold intolerance after hand injury: a systematic review.

The objective of this study was to investigate how a new customizable light-curable osteosynthesis method (AdFix) compared to traditional metal hardware when loaded in torsion in an ovine phalanx model. Twenty-one ovine proximal phalanges were given a 3mm transverse osteotomy and four 1.5mm cortex screws were inserted bicortically on either side of the gap. The light-curable polymer composite was then applied using the method developed by Hutchinson [1] to create osteosyntheses in two groups, having either a narrow (6mm, N=9) or a wide (10mm, N=9) fixation patch. A final group (N=3) was fixated with conventional metal plates. The constructs were loaded in torsion at a rate of 6°/second until failure or 45° of rotation was reached. Torque and angular displacement were measured, torsional stiffness was calculated as the slope of the Torque-Displacement curve, and maximum torque was queried for each specimen. The torsional stiffnesses of the narrow, wide, and metal plate constructs were 39.1 ± 6.2, 54.4 ± 6.3, and 16.2 ± 3.0 Nmm/° respectively. All groups were statistically different from each other (p<0.001). The maximum torques of the narrow, wide, and metal plate constructs were 424 ± 72, 600 ± 120, and 579 ± 20 Nmm respectively. The narrow constructs were statistically different from the other two (p<0.05), while the wide and metal constructs were not statistically different from each other (p=0.76). This work demonstrated that the torsional performance of the novel solution is comparable to metal fixators. As a measure of the functional range, the torsional stiffness in the AdhFix exceeded that of the metal plate. Furthermore, the wide patches were able to sustain a similar maximum toque as the metal plates. These results suggest AdhFix to be a viable, customizable alternative to metal implants for fracture fixation in the hand

To ensure clinical relevance, the in vitro engineering of tissues for implantation requires artificial replacements to possess properties similar to native anatomy. Our overarching study is focussed on developing a bespoke bone-tendon in vitro model replicating the anatomy at the flexor digitorum profundus (FDP) tendon insertion site at the distal phalanx. Anatomical morphometric analysis has guided FDP tendon model design consisting of hard and soft tissue types. Here, we investigate potential materials for creation of the model's bone portion by comparison of two bone cements; brushite and genex (Biocomposites Ltd). 3D printed molds were prepared based on anatomical morphometric analysis of the FDP tendon insertion site and used to cast identical bone blocks from brushite and genex cements. Studies assessing the suitability of each cement type were conducted e.g. setting times, pH on submersion in culture medium and interaction with fibrin gels. Data was collected using qualitative imaging and qualitative measurements (N=3,n=6) for experimental conditions. Both brushite (BC) and genex (GC) cements could be cast into bespoke molds, producing individual blocks and were mixed/handled with appropriate setting times. On initial submersion in culture medium, BC caused a reduction in pH values (7.49 [control]) to 6.85) while GC remained stable (7.59). Reduction in pH value also affected fibrin gel interaction where gel was seen to be detaching/not forming around BC and medium discolouration was noted. This was not observed in GC. While GC outperformed BC in initial tests, repeated washing of BC led to pH stabilisation (7.5,3xwashes), consistent with their further use in this model. This study has compared BC and GC as materials for bone block production. Both materials show promise, and current work assessing material properties and cell proliferation are needed to inform our choice for use in our FDP-tendon-bone interface model. This research was supported by an ORUK Studentship award (ref:533). Genex was kindly provided by Biocomposites, Ltd

The February 2023 Wrist & Hand Roundup³⁶⁰ looks at: ‘Self-care’ protocol for minimally displaced distal radius fractures; Treatment strategies for acute Seymour fractures in children and adolescents: including crushed open fractures; Routinely collected outcomes of proximal row carpectomy; Moving minor hand surgeries in the office-based procedure room: a population-based trend analysis; A comparison between robotic-assisted scaphoid screw fixation and a freehand technique for acute scaphoid fracture: a randomized, controlled trial; Factors associated with conversion to surgical release after a steroid injection in patients with a trigger finger; Two modern total wrist arthroplasties: a randomized comparison; Triangular fibrocartilage complex suture repair reliable even in ulnar styloid nonunion.

This annotation reviews current concepts on the three most common surgical approaches used for proximal interphalangeal joint arthroplasty: dorsal, volar, and lateral. Advantages and disadvantages of each are highlighted, and the outcomes are discussed.

Cite this article: Bone Joint J 2022;104-B(12):1329–1333.

Aim. There are no definitive criteria for the definition of osteomyelitis in the hand and wrist and published case series are small. It remains a relatively uncommon, but difficult to treat problem. We present a series of 30 cases from 2016 to 2021 from a tertiary referral centre. We propose that the principles of thorough surgical debridement, dead space management, skeletal stabilisation and culture driven antibiotic therapy are the key to management of osteomyelitis in the hand and wrist. In addition, we show how these basic principles can be used for both functional and aesthetic impact for the wrist and digits with illustrated cases. Methods. We conducted a retrospective chart review over a 6 year period and recorded the site of the infection, the soft tissue and bony management, whether antibiotic eluting bone filler was used, the isolated bacterial species, the number of surgical procedures undertaken to treat the infection and the success rate for clearing the infection. Results. 17/30 cases had pre-existing metalwork in-situ. There were 19 phalangeal/metacarpal infections and 11 carpal infections. 24 patients had native joint involvement. A drug eluting bone void filler was used in 23/30 cases in order to manage the dead space. In 7/30 cases had polymicrobial organisms isolated, 15/30 had only one organism cultured. The most common organism cultured was Staphylococcus aureus. Complete resolution of osteomyelitis or joint infection was achieved in 29/30 cases with follow up ranging from six months to six years. 2/30 cases required thorough debridement of the distal phalanx; bone void filler provided an aesthetically optimal result to improve fingertip contour whilst managing the dead space. Conclusion. Osteomyelitis of the hand and wrist is optimally managed with thorough surgical debridement, dead space management with a drug eluting bone void filler, skeletal stabilisation and culture directed antibiotic therapy. In addition, the bone void filler provides pulp support and improves the aesthetic contour of fingertips in which distal phalangeal osteomyelitis was successfully treated

Aims

The Open-Fracture Patient Evaluation Nationwide (OPEN) study was performed to provide clarity in open fracture management previously skewed by small, specialist centre studies and large, unfocused registry investigations. We report the current management metrics of open fractures across the UK.

The Poole Traction Splint (PTS) is a non-invasive technique that applies dynamic traction to the affected digit using materials readily available in the outpatient department. The primary aim of this study was to document the outcome of the PTS for hand phalangeal fractures. Over a four-year period (2017–2021), suitable patients were reviewed and referred for PTS to the hand physiotherapists. Functional outcome measures included range of motion (ROM), return to work, and a DASH score. In addition, a healthcare cost analysis was carried out. A total of 63 patients were treated with a PTS from 2017 to 2021. Data was analysed for 54 patients with 55 digits. The mean age was 43 years (17–72) and 53.7% (n=29) were female. There were 43 fractures involving the proximal phalanx and 12 involving the middle phalanx. The mean final composite range of movement averaged 209˚ (110–270°), classified as ‘good/excellent’ by ASSH criteria. The mean DASH score was 13.6 (0-43.2; n=45). All patients were able to return to work. Only two (3.7%) digits required conversion to surgical fixation. The PTS resulted in approximate savings of £2,452 per patient. The PTS is a cost-effective non-invasive low risk outpatient treatment method which provides a functional ROM and good functional outcomes in the treatment of complex phalangeal hand fractures, with minimal risk of surgical intervention being required