The April 2024 Foot & Ankle Roundup³⁶⁰ looks at: Safety of arthroscopy combined with radial extracorporeal shockwave therapy for osteochondritis of the talus; Bipolar allograft transplantation of the ankle; Identifying risk factors for osteonecrosis after talar fracture; Balancing act: immediate versus delayed weightbearing in ankle fracture recovery; Levelling the field: proximal supination osteotomy’s efficacy in severe and super-severe hallux valgus; Restoring balance: how adjusting the tibiotalar joint line influences movement after ankle surgery.

Abstract. Introduction. Symptomatic osteochondritis dissecans (OCD) and traumatic osteochondral fractures (OCF) are treated with fixation with either metal or bioabsorbable device. We performed a comparative review of patients with OCD and traumatic OCF stabilised with Bio-Compression screws which are headless absorbable compression screws. Our aim was to determine whether there was a difference in outcomes between presentations. Methods. Retrospective single-centre cohort study of all patients with OCD and OCF treated with Bio-Compression screw between July 2017 and September 2022. All patients followed up until discharge with satisfactory clinical outcome. Primary outcome was return to theatre for ongoing pain or mechanical symptoms. Secondary outcome was evidence of fixation failure on follow-up MRI scan. Results. 20 patients included; 8 OCF and 12 OCD. Average age 21 (OCF), 24 (OCD). The most common location was patella (58%) in OCF or the medial femoral condyle (75%) in OCD. Traumatic defects were smaller (2.6cm2 vs 3.3cm2) although this was not statistically significant (p=0.28). In the OCF group one patient went on to have further surgery. There were no re-operations in the OCD group. Both groups had good outcomes and similar times to discharge. There was no evidence of fixation failure of Bio-Compression screws on MRI scans. Conclusions. Within the limits of this relatively small cohort there is no significant difference between outcomes for OCD or traumatic OCF fixation with Bio-Compression screws. Both groups demonstrate good outcomes irrespective of the location or the aetiology of the fragment

Aims

Dead-space management, following dead bone resection, is an important element of successful chronic osteomyelitis treatment. This study compared two different biodegradable antibiotic carriers used for dead-space management, and reviewed clinical and radiological outcomes. All cases underwent single-stage surgery and had a minimum one-year follow-up.

Screw fixation is an established method for anterior cruciate ligament (ACL) reconstruction, although with a high rate of implant-related complications. An allograft system for implant fixation in ACL reconstruction, the Shark Screw ACL (surgebright GmbH) could overcome some of the shortcomings of bioabsorbable screws, such as foreign body reaction, need for implant removal and imaging artefacts. However, it needs to provide sufficient mechanical stability. Therefore, the aim of this study was to investigate the biomechanical stability, especially graft slippage, of the novel allograft system versus a conventional bioabsorbable interference screw (BioComposite Interference Screw; Arthrex Inc.) for tibial implant fixation in ACL reconstruction. Twenty-four paired human proximal tibiae (3 female, 9 male, 72.7 ± 5.6 years) underwent ACL reconstruction. The quadrupled semitendinosus and gracilis tendon graft were fixed in one specimen of each pair using the allograft fixation system Shak Screw ACL and the contralateral one using an interference screw. All specimens were cyclically loaded at 1 Hz with peak load levels monotonically increased from 50 N at a rate of 0.1 N/cycle until catastrophic failure. Relative movements of the graft versus the tibia were captured with a stereographic optical motion tracking system (Aramis SRX; GOM GmbH). The two fixation methods did not demonstrate any statistical difference in ultimate load at graft slippage (p = 0.24) or estimated survival at slippage (p = 0.06). Both, the ultimate load and estimated survival until failure were higher in the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 mm (interference screw) and 11.3 mm (Shark Screw ACL). The allograft screw for implant fixation in ACL reconstruction showed similar behavior in terms of graft slippage compared to the conventional metal interference screw but underperformed in terms of ultimate load. However, the ultimate load may not be considered a direct indicator of clinical failure

Aim. Excision of chronic osteomyelitis (cOM) creates a dead space which must be managed to avoid early recurrence of infection. Systemic antimicrobials cannot penetrate this space in high concentration so local therapy has become an attractive adjunct to surgery. This study presents the mid- long-term results of local therapy with gentamicin in a bioabsorbable ceramic carrier. Method. A prospective series of 100 patients with Cierny & Mader Types III and IV cOM, affecting 105 bones, were treated with a single stage procedure, including debridement, deep tissue sampling, local and systemic antimicrobials, stabilization and immediate skin closure. cOM was confirmed with strict diagnostic criteria. Patients were followed up for a mean of 6.05 years (range 4.2–8.4 years). Results. At final follow-up, 6 patients had evidence of recurrent infection (94% infection-free). 3 infections recurred in the first year, with 2 in the second year and one at 4.5 years after surgery. Recurrence was not dependent on host physiological class (1/20 Class A; 5% vs 5/80 Class B; 6.25%. p=0.833). Nor was it related to aetiology of the infection, microbial culture or the presence of an infected non-union before surgery (1/10 with non-union; 10% vs 5/90 without non-union; 5.6%. p=0.57). Organisms which demonstrated intermediate or high-grade resistance to gentamicin were more likely in polymicrobial infections (9/21; 42.8%) compared to single isolate osteomyelitis (7/79; 8.9%)(p<0.001). However, recurrence was not more frequent when a resistant organism was present (1/16; 6.25% for resistant cases vs 5/84; 5.95% in sensitive culture infection) (p=0.96). Conclusions. This study shows that the single stage protocol, including a high delivery local antibiotic ceramic, was effective over several years. The method can be applied to a wide range of patients, including those with significant comorbidities and infected non-union

Aims. Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier. Methods. A prospective series of 100 patients with Cierny-Mader Types III and IV chronic ostemyelitis, affecting 105 bones, were treated with a single-stage procedure including debridement, deep tissue sampling, local and systemic antibiotics, stabilization, and immediate skin closure. Chronic osteomyelitis was confirmed using strict diagnostic criteria. The mean follow-up was 6.05 years (4.2 to 8.4). Results. At final follow-up, six patients (six bones) had recurrent infection; thus 94% were infection-free. Three infections recurred in the first year, two in the second year, and one 4.5 years postoperatively. Recurrence was not significantly related to the physiological class of the patient (1/20 Class A (5%) vs 5/80 Class B (6.25%); p = 0.833), nor was it significantly related to the aetiology of the infection, the organisms which were cultured or the presence of nonunion before surgery (1/10 with nonunion (10%) vs 5/90 without nonunion (5.6%); p = 0.570). Organisms with intermediate or high-grade resistance to gentamicin were significantly more likely in polymicrobial infections (9/21; 42.8%) compared with monobacterial osteomyelitis (7/79 (8.9%); p < 0.001). However, recurrence was not significantly more frequent when a resistant organism was present (1/16 for resistant cases (6.25%) vs 5/84 in those with a microbiologically sensitive infection (5.95%); p = 0.958). Conclusion. We found that a single-stage protocol, including the use of a high-delivery local antibiotic ceramic carrier, was effective over a period of several years. The method can be used in a wide range of patients, including those with significant comorbidities and an infected nonunion. Cite this article: Bone Joint J 2022;104-B(9):1095–1100

Aims

The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective.

Aims

Poly(methyl methacrylate) (PMMA)-based bone cements are the industry standard in orthopaedics. PMMA cement has inherent disadvantages, which has led to the development and evaluation of a novel silorane-based biomaterial (SBB) for use as an orthopaedic cement. In this study we test both elution and mechanical properties of both PMMA and SBB, with and without antibiotic loading.

Aims

Our purpose was to describe an unusual series of 21 patients with fungal osteomyelitis after an anterior cruciate ligament reconstruction (ACL-R).

Bioabsorbable metals hold a lot of potential as orthopaedic implant materials. Three metal families are currently being investigated: iron (Fe), magnesium (Mg) and zinc (Zn). Currently, however, biodegradation of such implants is poorly predictable. We thus used Direct Metal Printing to additively manufacture porous implants of a standardized bone-mimetic design and evaluated their mechanical properties and degradation behaviour, respectively, under in vivo-like conditions. Atomized powder was manufactured to porous implants of repetitive diamond unit cells, using a ProX DMP 320 (Layerwise, Belgium) or a custom-modified ReaLizer SLM50 metal printer. Degradation behaviour was characterized under static and dynamic conditions in a custom-built bioreactor system (37ºC, 5% CO. 2. and 20% O. 2. ) for up of 28 days. Implants were characterized by micro-CT before and after in vivo-like degradation. Mechanical characterization (according to ISO 13314: 2011) was performed on an Instron machine (10kN load cell) at different immersion times in simulated body fluid (r-SBF). Morphology and composition of degradation products were analysed (SEM, JSM-IT100, JEOL). Topographically identical titanium (Ti-6Al-4V, Ti64) specimen served as reference. Micro-CT analyses confirmed average strut sizes (420 ± 4 μm), and porosity (64%), to be close to design values. After 28 days of in vivo-like degradation, scaffolds were macroscopically covered by degradation products in an alloy-specific manner. Weight loss after cleaning also varied alloy-specifically, as did the change in pH value of the r-SBF. Corrosion time-dependent changes in Young's moduli from 1200 to 800 MPa for Mg, 1000 to 700 MPa for Zn and 48-8 MPa for iron were statistically significant. In summary, DMP allows to accurately control interconnectivity and topology of implants from all three families and micro-structured design holds potential to optimize their degradation speed. This first systematic report sheds light into how design influences degradation behaviour under in vivo-like conditions to help developing new standards for future medical device evaluation

Aims

The hypothesis of this study was that bone peg fixation in the treatment of osteochondral lesions of the talus would show satisfactory clinical and radiological results, without complications.

Aims. This study is a prospective, non-randomized trial for the treatment of fractures of the medial malleolus using lean, bioabsorbable, rare-earth element (REE)-free, magnesium (Mg)-based biodegradable screws in the adult skeleton. Methods. A total of 20 patients with isolated, bimalleolar, or trimalleolar ankle fractures were recruited between July 2018 and October 2019. Fracture reduction was achieved through bioabsorbable Mg-based screws composed of pure Mg alloyed with zinc (Zn) and calcium (Ca) ( Mg-Zn0.45-Ca0.45, in wt.%; ZX00). Visual analogue scale (VAS) and the presence of complications (adverse events) during follow-up (12 weeks) were used to evaluate the clinical outcomes. The functional outcomes were analyzed through the range of motion (ROM) of the ankle joint and the American Orthopaedic Foot and Ankle Society (AOFAS) score. Fracture reduction and gas formation were assessed using several plane radiographs. Results. The follow-up was performed after at least 12 weeks. The mean difference in ROM of the talocrural joint between the treated and the non-treated sites decreased from 39° (SD 12°) after two weeks to 8° (SD 11°) after 12 weeks (p ≤ 0.05). After 12 weeks, the mean AOFAS score was 92.5 points (SD 4.1). Blood analysis revealed that Mg and Ca were within a physiologically normal range. All ankle fractures were reduced and stabilized sufficiently by two Mg screws. A complete consolidation of all fractures was achieved. No loosening or breakage of screws was observed. Conclusion. This first prospective clinical investigation of fracture reduction and fixation using lean, bioabsorbable, REE-free ZX00 screws showed excellent clinical and functional outcomes. Cite this article: Bone Joint Res 2020;9(8):477–483

Aims

The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair.

Objectives

This study investigated the biomechanical performance of decellularized porcine superflexor tendon (pSFT) grafts of varying diameters when utilized in conjunction with contemporary ACL graft fixation systems. This aimed to produce a range of ‘off-the-shelf’ products with predictable mechanical performance, depending on the individual requirements of the patient.

Introduction. Patients with hip abductor tendon tears amenable to endoscopic repair tend to be severely disabled and older. However, low preop baseline patient reported outcome (PRO) and advancing age are each often reported to be a harbinger of poor result with hip arthroscopy. Thus, the purpose of this study is to report the demographic makeup of this population and how these patients faired in terms of preop scores and reaching both Minimal Clinically Important Difference (MCID) and Substantial Clinical Benefit (SCB). Methods. Sixty-six consecutive hips in 64 patients (2 bilateral) undergoing endoscopic abductor tendon repair with a hollow core bioabsorbable suture anchor and having achieved two-year follow-up were prospectively assessed with modified Harris Hip Score (mHHS) and international Hip Outcome Tool (iHOT) scores. The MCID for patients undergoing hip arthroscopy has previously been determined as 8 for the mHHS and 13 for the iHOT. SCB has been determined as 20 for the mHHS and 28 for the iHOT. Subgroups were compared using the independent samples t-test. Results. The average age was 57 years (range 22–83 years) with 59 females and 5 males. Post-operative follow-up averaged 28 months (range 24–60). There were 33 full-thickness and 33 partial-thickness tears; 39 gluteus medius tears, 25 medius and minimus tears, and 2 isolated minimus tears. Among the 66 hips, the average preop mHHS was 48.8 with 98.5% achieving MCID and 93.8% SCB. Among 60 hips that had complete iHOT data, the average preop score was 30.0 with 98.3% achieving MCID and 88.3% SCB. There were no complications. One patient underwent repeat arthroscopy for joint debridement at 12 months following abductor repair, and one subsequently underwent total hip replacement at 11 months following repair. There was no statistically significant difference between subgroups of full thickness/partial thickness tears, or single/two tendon tears. Conclusion. This report of endoscopic abductor tendon repair represents a heterogeneous group of single and two tendon involvement with partial and full thickness tears. Collectively these patients can respond exceptionally well in terms of MCID (98.5% mHHS; 98.3% iHOT) and SCB (93.8% mHHS; 88.3% iHOT), even in the presence of low preop baseline scores (average 48.8 mHHS; 30 iHOT) and older age (average 57 years). For any tables or figures, please contact the authors directly

Aim

This study describes the histologic changes seen with a gentamicin-eluting synthetic bone graft substitute (BGS)(1) in managing bone defects after resection of chronic osteomyelitis (cOM).

Aims

The aim of this study was to evaluate antegrade autologous bone grafting with the preservation of articular cartilage in the treatment of symptomatic osteochondral lesions of the talus with subchondral cysts.

Objective

In the present study, we aimed to assess whether gelatin/β-tricalcium phosphate (β-TCP) composite porous scaffolds could be used as a local controlled release system for vancomycin. We also investigated the efficiency of the scaffolds in eliminating infections and repairing osteomyelitis defects in rabbits.